Example #1
0
/**
 * Reassembles incoming IP fragments into an IP datagram.
 *
 * @param p points to a pbuf chain of the fragment
 * @return NULL if reassembly is incomplete, ? otherwise
 */
struct pbuf *
ip_reass(struct pbuf *p)
{
  struct pbuf *r;
  struct ip_hdr *fraghdr;
  struct ip_reassdata *ipr;
  struct ip_reass_helper *iprh;
  u16_t offset, len;
  u8_t clen;
  struct ip_reassdata *ipr_prev = NULL;

  IPFRAG_STATS_INC(ip_frag.recv);
  snmp_inc_ipreasmreqds();

  fraghdr = (struct ip_hdr*)p->payload;

  if ((IPH_HL(fraghdr) * 4) != IP_HLEN) {
    LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: IP options currently not supported!\n"));
    IPFRAG_STATS_INC(ip_frag.err);
    goto nullreturn;
  }

  offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
  len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;

  /* Check if we are allowed to enqueue more datagrams. */
  clen = pbuf_clen(p);
  if ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) {
#if IP_REASS_FREE_OLDEST
    if (!ip_reass_remove_oldest_datagram(fraghdr, clen) ||
        ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS))
#endif /* IP_REASS_FREE_OLDEST */
    {
      /* No datagram could be freed and still too many pbufs enqueued */
      LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: Overflow condition: pbufct=%d, clen=%d, MAX=%d\n",
        ip_reass_pbufcount, clen, IP_REASS_MAX_PBUFS));
      IPFRAG_STATS_INC(ip_frag.memerr);
      /* @todo: send ICMP time exceeded here? */
      /* drop this pbuf */
      goto nullreturn;
    }
  }

  /* Look for the datagram the fragment belongs to in the current datagram queue,
   * remembering the previous in the queue for later dequeueing. */
  for (ipr = reassdatagrams; ipr != NULL; ipr = ipr->next) {
    /* Check if the incoming fragment matches the one currently present
       in the reassembly buffer. If so, we proceed with copying the
       fragment into the buffer. */
    if (IP_ADDRESSES_AND_ID_MATCH(&ipr->iphdr, fraghdr)) {
      LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass: matching previous fragment ID=%"X16_F"\n",
        ntohs(IPH_ID(fraghdr))));
      IPFRAG_STATS_INC(ip_frag.cachehit);
      break;
    }
    ipr_prev = ipr;
  }

  if (ipr == NULL) {
  /* Enqueue a new datagram into the datagram queue */
    ipr = ip_reass_enqueue_new_datagram(fraghdr, clen);
    /* Bail if unable to enqueue */
    if(ipr == NULL) {
      goto nullreturn;
    }
  } else {
    if (((ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) == 0) && 
      ((ntohs(IPH_OFFSET(&ipr->iphdr)) & IP_OFFMASK) != 0)) {
      /* ipr->iphdr is not the header from the first fragment, but fraghdr is
       * -> copy fraghdr into ipr->iphdr since we want to have the header
       * of the first fragment (for ICMP time exceeded and later, for copying
       * all options, if supported)*/
      SMEMCPY(&ipr->iphdr, fraghdr, IP_HLEN);
    }
  }
  /* Track the current number of pbufs current 'in-flight', in order to limit 
  the number of fragments that may be enqueued at any one time */
  ip_reass_pbufcount += clen;

  /* At this point, we have either created a new entry or pointing 
   * to an existing one */

  /* check for 'no more fragments', and update queue entry*/
  if ((IPH_OFFSET(fraghdr) & PP_NTOHS(IP_MF)) == 0) {
    ipr->flags |= IP_REASS_FLAG_LASTFRAG;
    ipr->datagram_len = offset + len;
    LWIP_DEBUGF(IP_REASS_DEBUG,
     ("ip_reass: last fragment seen, total len %"S16_F"\n",
      ipr->datagram_len));
  }
  /* find the right place to insert this pbuf */
  /* @todo: trim pbufs if fragments are overlapping */
  if (ip_reass_chain_frag_into_datagram_and_validate(ipr, p)) {
    /* the totally last fragment (flag more fragments = 0) was received at least
     * once AND all fragments are received */
    ipr->datagram_len += IP_HLEN;

    /* save the second pbuf before copying the header over the pointer */
    r = ((struct ip_reass_helper*)ipr->p->payload)->next_pbuf;

    /* copy the original ip header back to the first pbuf */
    fraghdr = (struct ip_hdr*)(ipr->p->payload);
    SMEMCPY(fraghdr, &ipr->iphdr, IP_HLEN);
    IPH_LEN_SET(fraghdr, htons(ipr->datagram_len));
    IPH_OFFSET_SET(fraghdr, 0);
    IPH_CHKSUM_SET(fraghdr, 0);
    /* @todo: do we need to set calculate the correct checksum? */
    IPH_CHKSUM_SET(fraghdr, inet_chksum(fraghdr, IP_HLEN));

    p = ipr->p;

    /* chain together the pbufs contained within the reass_data list. */
    while(r != NULL) {
      iprh = (struct ip_reass_helper*)r->payload;

      /* hide the ip header for every succeding fragment */
      pbuf_header(r, -IP_HLEN);
      pbuf_cat(p, r);
      r = iprh->next_pbuf;
    }
    /* release the sources allocate for the fragment queue entry */
    ip_reass_dequeue_datagram(ipr, ipr_prev);

    /* and adjust the number of pbufs currently queued for reassembly. */
    ip_reass_pbufcount -= pbuf_clen(p);

    /* Return the pbuf chain */
    return p;
  }
  /* the datagram is not (yet?) reassembled completely */
  LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass_pbufcount: %d out\n", ip_reass_pbufcount));
  return NULL;

nullreturn:
  LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass: nullreturn\n"));
  IPFRAG_STATS_INC(ip_frag.drop);
  pbuf_free(p);
  return NULL;
}
Example #2
0
/**
 * Should allocate a pbuf and transfer the bytes of the incoming
 * packet from the interface into the pbuf.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return a pbuf filled with the received packet (including MAC header)
 *         NULL on memory error
 */
static struct pbuf *low_level_input(struct netif *netif)
{
    struct pbuf *p, *q;
    int32_t len;
    int l = 0;

    /* Obtain the size of the packet and put it into the "len"
       variable. */
    len = csi_eth_mac_read_frame(eth_mac_handle, Data_Buf, MAX_FRAMELEN);

    if (len < 0) {
        /* errors in rx buffer, reset enc28j60 */
        LOGE(TAG, "err rxb, rst");

        yoc_nic_reset();

        return NULL;
    } else if (len == 0) {
        return NULL;
    }

#if ETH_PAD_SIZE
    len += ETH_PAD_SIZE; /* allow room for Ethernet padding */
#endif

    /* We allocate a pbuf chain of pbufs from the pool. */
    p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);

    if (p != NULL) {

#if ETH_PAD_SIZE
        pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
#endif

        /* We iterate over the pbuf chain until we have read the entire
         * packet into the pbuf. */
        for (q = p; q != NULL; q = q->next) {
            /* Read enough bytes to fill this pbuf in the chain. The
             * available data in the pbuf is given by the q->len
             * variable.
             * This does not necessarily have to be a memcpy, you can also preallocate
             * pbufs for a DMA-enabled MAC and after receiving truncate it to the
             * actually received size. In this case, ensure the tot_len member of the
             * pbuf is the sum of the chained pbuf len members.
             */
            /* read data into(q->payload, q->len); */
            memcpy((u8_t *)q->payload, (u8_t *)&Data_Buf[l], q->len);
            l = l + q->len;
        }

        MIB2_STATS_NETIF_ADD(netif, ifinoctets, p->tot_len);

        if (((u8_t *)p->payload)[0] & 1) {
            /* broadcast or multicast packet */
            MIB2_STATS_NETIF_INC(netif, ifinnucastpkts);
        } else {
            /* unicast packet */
            MIB2_STATS_NETIF_INC(netif, ifinucastpkts);
        }

#if ETH_PAD_SIZE
        pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
#endif

        LINK_STATS_INC(link.recv);
    } else {
        /* drop packet(); */
        /* error to allocate a pbuf chain of pbufs from the pool */
        LOGE(TAG, "err alloc pbuf");
        LINK_STATS_INC(link.memerr);
        LINK_STATS_INC(link.drop);
        MIB2_STATS_NETIF_INC(netif, ifindiscards);
    }

    return p;
}
void
ip_input(struct pbuf *p, struct netif *inp) {
  struct ip_hdr *iphdr;
  struct netif *netif;


  PERF_START;

#if IP_DEBUG
  ip_debug_print(p);
#endif /* IP_DEBUG */


  IP_STATS_INC(ip.recv);

  /* identify the IP header */
  iphdr = p->payload;


  if (iphdr->v != 6) {
    LWIP_DEBUGF(IP_DEBUG, ("IP packet dropped due to bad version number\n"));
#if IP_DEBUG
    ip_debug_print(p);
#endif /* IP_DEBUG */
    pbuf_free(p);
    IP_STATS_INC(ip.err);
    IP_STATS_INC(ip.drop);
    return;
  }

  /* is this packet for us? */
  for(netif = netif_list; netif != NULL; netif = netif->next) {
#if IP_DEBUG
    LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest "));
    ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
    LWIP_DEBUGF(IP_DEBUG, ("netif->ip_addr "));
    ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
    LWIP_DEBUGF(IP_DEBUG, ("\n"));
#endif /* IP_DEBUG */
    if (ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr))) {
      break;
    }
  }


  if (netif == NULL) {
    /* packet not for us, route or discard */
#if IP_FORWARD
    ip_forward(p, iphdr);
#endif
    pbuf_free(p);
    return;
  }

  pbuf_realloc(p, IP_HLEN + ntohs(iphdr->len));

  /* send to upper layers */
#if IP_DEBUG
  /*  LWIP_DEBUGF("ip_input: \n");
  ip_debug_print(p);
  LWIP_DEBUGF("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len);*/
#endif /* IP_DEBUG */

  if(pbuf_header(p, -IP_HLEN)) {
    LWIP_ASSERT("Can't move over header in packet", 0);
    return;
  }

  switch (iphdr->nexthdr) {
  case IP_PROTO_UDP:
    udp_input(p, inp);
    break;
  case IP_PROTO_TCP:
    tcp_input(p, inp);
    break;
#if LWIP_ICMP
  case IP_PROTO_ICMP:
    icmp_input(p, inp);
    break;
#endif /* LWIP_ICMP */
  default:
#if LWIP_ICMP
    /* send ICMP destination protocol unreachable */
    icmp_dest_unreach(p, ICMP_DUR_PROTO);
#endif /* LWIP_ICMP */
    pbuf_free(p);
    LWIP_DEBUGF(IP_DEBUG, ("Unsupported transport protocol %"U16_F"\n",
          iphdr->nexthdr));

    IP_STATS_INC(ip.proterr);
    IP_STATS_INC(ip.drop);
  }
  PERF_STOP("ip_input");
}
Example #4
0
END_TEST

/** Check that we handle malformed tcp headers, and discard the pbuf(s) */
START_TEST(test_tcp_malformed_header)
{
  struct test_tcp_counters counters;
  struct tcp_pcb* pcb;
  struct pbuf* p;
  char data[] = {1, 2, 3, 4};
  ip_addr_t remote_ip, local_ip, netmask;
  u16_t data_len, chksum;
  u16_t remote_port = 0x100, local_port = 0x101;
  struct netif netif;
  struct test_tcp_txcounters txcounters;
  struct tcp_hdr *hdr;
  LWIP_UNUSED_ARG(_i);

  /* initialize local vars */
  memset(&netif, 0, sizeof(netif));
  IP_ADDR4(&local_ip, 192, 168, 1, 1);
  IP_ADDR4(&remote_ip, 192, 168, 1, 2);
  IP_ADDR4(&netmask,   255, 255, 255, 0);
  test_tcp_init_netif(&netif, &txcounters, &local_ip, &netmask);
  data_len = sizeof(data);
  /* initialize counter struct */
  memset(&counters, 0, sizeof(counters));
  counters.expected_data_len = data_len;
  counters.expected_data = data;

  /* create and initialize the pcb */
  pcb = test_tcp_new_counters_pcb(&counters);
  EXPECT_RET(pcb != NULL);
  tcp_set_state(pcb, ESTABLISHED, &local_ip, &remote_ip, local_port, remote_port);

  /* create a segment */
  p = tcp_create_rx_segment(pcb, counters.expected_data, data_len, 0, 0, 0);

  pbuf_header(p, -(s16_t)sizeof(struct ip_hdr));

  hdr = (struct tcp_hdr *)p->payload;
  TCPH_HDRLEN_FLAGS_SET(hdr, 15, 0x3d1);

  hdr->chksum = 0;

  chksum = ip_chksum_pseudo(p, IP_PROTO_TCP, p->tot_len,
                             &remote_ip, &local_ip);

  hdr->chksum = chksum;

  pbuf_header(p, sizeof(struct ip_hdr));

  EXPECT(p != NULL);
  EXPECT(p->next == NULL);
  if (p != NULL) {
    /* pass the segment to tcp_input */
    test_tcp_input(p, &netif);
    /* check if counters are as expected */
    EXPECT(counters.close_calls == 0);
    EXPECT(counters.recv_calls == 0);
    EXPECT(counters.recved_bytes == 0);
    EXPECT(counters.err_calls == 0);
  }

  /* make sure the pcb is freed */
  EXPECT(MEMP_STATS_GET(used, MEMP_TCP_PCB) == 1);
  tcp_abort(pcb);
  EXPECT(MEMP_STATS_GET(used, MEMP_TCP_PCB) == 0);
}
Example #5
0
/**
 * Process an incoming UDP datagram.
 *
 * Given an incoming UDP datagram (as a chain of pbufs) this function
 * finds a corresponding UDP PCB and hands over the pbuf to the pcbs
 * recv function. If no pcb is found or the datagram is incorrect, the
 * pbuf is freed.
 *
 * @param p pbuf to be demultiplexed to a UDP PCB.
 * @param inp network interface on which the datagram was received.
 *
 */
void
udp_input(struct pbuf *p, struct netif *inp)
{
  struct udp_hdr *udphdr;
  struct udp_pcb *pcb, *prev;
  struct udp_pcb *uncon_pcb;
  struct ip_hdr *iphdr;
  u16_t src, dest;
  u8_t local_match;
  u8_t broadcast;

  PERF_START;

  UDP_STATS_INC(udp.recv);

  iphdr = (struct ip_hdr *)p->payload;

  /* Check minimum length (IP header + UDP header)
   * and move payload pointer to UDP header */
  if (p->tot_len < (IPH_HL(iphdr) * 4 + UDP_HLEN) || pbuf_header(p, -(s16_t)(IPH_HL(iphdr) * 4))) {
    /* drop short packets */
    LWIP_DEBUGF(UDP_DEBUG,
                ("udp_input: short UDP datagram (%"U16_F" bytes) discarded\n", p->tot_len));
    UDP_STATS_INC(udp.lenerr);
    UDP_STATS_INC(udp.drop);
    snmp_inc_udpinerrors();
    pbuf_free(p);
    goto end;
  }

  udphdr = (struct udp_hdr *)p->payload;

  /* is broadcast packet ? */
  broadcast = ip_addr_isbroadcast(&current_iphdr_dest, inp);

  LWIP_DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %"U16_F"\n", p->tot_len));

  /* convert src and dest ports to host byte order */
  src = ntohs(udphdr->src);
  dest = ntohs(udphdr->dest);

  udp_debug_print(udphdr);

  /* print the UDP source and destination */
  LWIP_DEBUGF(UDP_DEBUG,
              ("udp (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") <-- "
               "(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
               ip4_addr1_16(&iphdr->dest), ip4_addr2_16(&iphdr->dest),
               ip4_addr3_16(&iphdr->dest), ip4_addr4_16(&iphdr->dest), ntohs(udphdr->dest),
               ip4_addr1_16(&iphdr->src), ip4_addr2_16(&iphdr->src),
               ip4_addr3_16(&iphdr->src), ip4_addr4_16(&iphdr->src), ntohs(udphdr->src)));

#if LWIP_DHCP
  pcb = NULL;
  /* when LWIP_DHCP is active, packets to DHCP_CLIENT_PORT may only be processed by
     the dhcp module, no other UDP pcb may use the local UDP port DHCP_CLIENT_PORT */
  if (dest == DHCP_CLIENT_PORT) {
    /* all packets for DHCP_CLIENT_PORT not coming from DHCP_SERVER_PORT are dropped! */
    if (src == DHCP_SERVER_PORT) {
      if ((inp->dhcp != NULL) && (inp->dhcp->pcb != NULL)) {
        /* accept the packe if 
           (- broadcast or directed to us) -> DHCP is link-layer-addressed, local ip is always ANY!
           - inp->dhcp->pcb->remote == ANY or iphdr->src */
        if ((ip_addr_isany(&inp->dhcp->pcb->remote_ip) ||
           ip_addr_cmp(&(inp->dhcp->pcb->remote_ip), &current_iphdr_src))) {
          pcb = inp->dhcp->pcb;
        }
      }
    }
  } else
#endif /* LWIP_DHCP */
  {
    prev = NULL;
    local_match = 0;
    uncon_pcb = NULL;
    /* Iterate through the UDP pcb list for a matching pcb.
     * 'Perfect match' pcbs (connected to the remote port & ip address) are
     * preferred. If no perfect match is found, the first unconnected pcb that
     * matches the local port and ip address gets the datagram. */
    for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
      local_match = 0;
      /* print the PCB local and remote address */
      LWIP_DEBUGF(UDP_DEBUG,
                  ("pcb (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") --- "
                   "(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
                   ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
                   ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip), pcb->local_port,
                   ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
                   ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip), pcb->remote_port));

      /* compare PCB local addr+port to UDP destination addr+port */
      if (pcb->local_port == dest) {
        if (
           (!broadcast && ip_addr_isany(&pcb->local_ip)) ||
           ip_addr_cmp(&(pcb->local_ip), &current_iphdr_dest) ||
#if LWIP_IGMP
           ip_addr_ismulticast(&current_iphdr_dest) ||
#endif /* LWIP_IGMP */
#if IP_SOF_BROADCAST_RECV
            (broadcast && ip_get_option(pcb, SOF_BROADCAST) &&
             (ip_addr_isany(&pcb->local_ip) ||
              ip_addr_netcmp(&pcb->local_ip, ip_current_dest_addr(), &inp->netmask)))) {
#else /* IP_SOF_BROADCAST_RECV */
            (broadcast &&
             (ip_addr_isany(&pcb->local_ip) ||
              ip_addr_netcmp(&pcb->local_ip, ip_current_dest_addr(), &inp->netmask)))) {
#endif /* IP_SOF_BROADCAST_RECV */ 
          local_match = 1;
          if ((uncon_pcb == NULL) && 
              ((pcb->flags & UDP_FLAGS_CONNECTED) == 0)) {
            /* the first unconnected matching PCB */
            uncon_pcb = pcb;
          }
        }
      }
      /* compare PCB remote addr+port to UDP source addr+port */
      if ((local_match != 0) &&
          (pcb->remote_port == src) &&
          (ip_addr_isany(&pcb->remote_ip) ||
           ip_addr_cmp(&(pcb->remote_ip), &current_iphdr_src))) {
        /* the first fully matching PCB */
        if (prev != NULL) {
          /* move the pcb to the front of udp_pcbs so that is
             found faster next time */
          prev->next = pcb->next;
          pcb->next = udp_pcbs;
          udp_pcbs = pcb;
        } else {
          UDP_STATS_INC(udp.cachehit);
        }
        break;
      }
      prev = pcb;
    }
    /* no fully matching pcb found? then look for an unconnected pcb */
    if (pcb == NULL) {
      pcb = uncon_pcb;
    }
  }

  /* Check checksum if this is a match or if it was directed at us. */
  if (pcb != NULL || ip_addr_cmp(&inp->ip_addr, &current_iphdr_dest)) {
    LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: calculating checksum\n"));
#if LWIP_UDPLITE
    if (IPH_PROTO(iphdr) == IP_PROTO_UDPLITE) {
      /* Do the UDP Lite checksum */
#if CHECKSUM_CHECK_UDP
      u16_t chklen = ntohs(udphdr->len);
      if (chklen < sizeof(struct udp_hdr)) {
        if (chklen == 0) {
          /* For UDP-Lite, checksum length of 0 means checksum
             over the complete packet (See RFC 3828 chap. 3.1) */
          chklen = p->tot_len;
        } else {
          /* At least the UDP-Lite header must be covered by the
             checksum! (Again, see RFC 3828 chap. 3.1) */
          UDP_STATS_INC(udp.chkerr);
          UDP_STATS_INC(udp.drop);
          snmp_inc_udpinerrors();
          pbuf_free(p);
          goto end;
        }
      }
      if (inet_chksum_pseudo_partial(p, &current_iphdr_src, &current_iphdr_dest,
                             IP_PROTO_UDPLITE, p->tot_len, chklen) != 0) {
       LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
                   ("udp_input: UDP Lite datagram discarded due to failing checksum\n"));
        UDP_STATS_INC(udp.chkerr);
        UDP_STATS_INC(udp.drop);
        snmp_inc_udpinerrors();
        pbuf_free(p);
        goto end;
      }
#endif /* CHECKSUM_CHECK_UDP */
    } else
#endif /* LWIP_UDPLITE */
    {
#if CHECKSUM_CHECK_UDP
      if (udphdr->chksum != 0) {
        if (inet_chksum_pseudo(p, ip_current_src_addr(), ip_current_dest_addr(),
                               IP_PROTO_UDP, p->tot_len) != 0) {
          LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
                      ("udp_input: UDP datagram discarded due to failing checksum\n"));
          UDP_STATS_INC(udp.chkerr);
          UDP_STATS_INC(udp.drop);
          snmp_inc_udpinerrors();
          pbuf_free(p);
          goto end;
        }
      }
#endif /* CHECKSUM_CHECK_UDP */
    }
    if(pbuf_header(p, -UDP_HLEN)) {
      /* Can we cope with this failing? Just assert for now */
      LWIP_ASSERT("pbuf_header failed\n", 0);
      UDP_STATS_INC(udp.drop);
      snmp_inc_udpinerrors();
      pbuf_free(p);
      goto end;
    }
    if (pcb != NULL) {
      snmp_inc_udpindatagrams();
#if SO_REUSE && SO_REUSE_RXTOALL
      if ((broadcast || ip_addr_ismulticast(&current_iphdr_dest)) &&
          ip_get_option(pcb, SOF_REUSEADDR)) {
        /* pass broadcast- or multicast packets to all multicast pcbs
           if SOF_REUSEADDR is set on the first match */
        struct udp_pcb *mpcb;
        u8_t p_header_changed = 0;
        for (mpcb = udp_pcbs; mpcb != NULL; mpcb = mpcb->next) {
          if (mpcb != pcb) {
            /* compare PCB local addr+port to UDP destination addr+port */
            if ((mpcb->local_port == dest) &&
                ((!broadcast && ip_addr_isany(&mpcb->local_ip)) ||
                 ip_addr_cmp(&(mpcb->local_ip), &current_iphdr_dest) ||
#if LWIP_IGMP
                 ip_addr_ismulticast(&current_iphdr_dest) ||
#endif /* LWIP_IGMP */
#if IP_SOF_BROADCAST_RECV
                 (broadcast && ip_get_option(mpcb, SOF_BROADCAST)))) {
#else  /* IP_SOF_BROADCAST_RECV */
                 (broadcast))) {
#endif /* IP_SOF_BROADCAST_RECV */
              /* pass a copy of the packet to all local matches */
              if (mpcb->recv != NULL) {
                struct pbuf *q;
                /* for that, move payload to IP header again */
                if (p_header_changed == 0) {
                  pbuf_header(p, (s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
                  p_header_changed = 1;
                }
                q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
                if (q != NULL) {
                  err_t err = pbuf_copy(q, p);
                  if (err == ERR_OK) {
                    /* move payload to UDP data */
                    pbuf_header(q, -(s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
                    mpcb->recv(mpcb->recv_arg, mpcb, q, ip_current_src_addr(), src);
                  }
                }
              }
            }
          }
        }
        if (p_header_changed) {
          /* and move payload to UDP data again */
          pbuf_header(p, -(s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
        }
      }
#endif /* SO_REUSE && SO_REUSE_RXTOALL */
      /* callback */
      if (pcb->recv != NULL) {
        /* now the recv function is responsible for freeing p */
        pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr(), src);
      } else {
        /* no recv function registered? then we have to free the pbuf! */
        pbuf_free(p);
        goto end;
      }
    } else {
Example #6
0
/*
 * Reads RX responses for a single packet
 */
static int netfront_get_responses(struct netfront_dev *dev,
				  RING_IDX rp)
{
	struct netif_rx_response *rsp = &(dev->rsp);
	int32_t realsize = rsp->status;
	int16_t size = rsp->status;
	uint16_t id = rsp->id;
	uint16_t flags = rsp->flags;
	RING_IDX cons = rp;
	uint16_t slots = 1;
	int drop = 0;
#ifdef HAVE_LWIP
	struct pbuf *p;
	struct pbuf *first_p;
#endif

	dprintk("rx: ring: len %d %s\n", size,
		(flags & NETRXF_more_data ? "(more true) ": ""));

	BUG_ON(id >= NET_RX_RING_SIZE);

	if (flags & NETRXF_extra_info) {
		memset(dev->extras, 0, sizeof(dev->extras));
		netfront_get_extras(dev, dev->extras, cons);
		cons = dev->rx.rsp_cons;
	}

	if (flags & NETRXF_more_data) {
		dprintk("rx: scan: slot 0 len %d %s\n",
			size, (flags & NETRXF_more_data ? "(more true)": ""));
		realsize = size + netfront_get_size(dev, cons);
	}

	dprintk("rx: %c%c- %"PRIi32" bytes\n",
		flags & NETRXF_extra_info ? 'S' : '-',
		flags & ((NETRXF_csum_blank) | (NETRXF_data_validated)) ? 'C' : '-',
		realsize);

#ifdef HAVE_LWIP
	if (likely(dev->netif_rx_pbuf)) {
#ifdef CONFIG_NETFRONT_PERSISTENT_GRANTS
	  first_p = p = netfront_alloc_pbuf(dev, realsize);
	  drop = (p == NULL);
#else
	  first_p = p = &dev->rx_buffers[id]->cpbuf.pbuf;
	  drop = 0;
	  dev->pbuf_cur = p;
#endif /* CONFIG_NETFRONT_PERSISTENT_GRANTS */

#if ETH_PAD_SIZE
	  if (likely(!drop))
	    pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
#endif /* ETH_PAD_SIZE */
	}
#endif /* HAVE_LWIP */

	for (;;) {
		if (unlikely(rsp->status < 0 ||
			     (rsp->offset + rsp->status > PAGE_SIZE))) {
			printk("rx: ring<%u>: status %d, flags %04x, offset %d\n",
			       cons + slots, size, flags, rsp->offset);
		} else if (likely(!drop)) {
#ifdef CONFIG_NETFRONT_PERSISTENT_GRANTS
			handle_buffer(dev, rsp, &dev->rx_buffers[id], realsize);
#else
			handle_buffer(dev, rsp, dev->rx_buffers[id], realsize);
#endif
		}

#ifndef CONFIG_NETFRONT_PERSISTENT_GRANTS
		BUG_ON(dev->rx_buffers[id]->gref == GRANT_INVALID_REF);
		gnttab_end_access(dev->rx_buffers[id]->gref);
		dev->rx_buffers[id]->gref = GRANT_INVALID_REF;
		dev->rx_buffers[id] = NULL;
#endif

		if (!(flags & NETRXF_more_data))
			break;

		if (dev->rx.sring->rsp_prod <= cons + slots)
			break;

		rsp = RING_GET_RESPONSE(&dev->rx, cons + slots);
		id = rsp->id;
		BUG_ON(id >= NET_RX_RING_SIZE);
		size = rsp->status;
		flags = rsp->flags;
		slots++;
#ifndef CONFIG_NETFRONT_PERSISTENT_GRANTS
		if (likely(dev->netif_rx_pbuf && (!drop))) {
			/* set tot_len */
			p->tot_len = realsize;
			realsize -= p->len;
			/* ..and link it to next pbuf */
			p->next = &dev->rx_buffers[id]->cpbuf.pbuf;
			dev->pbuf_cur = p = p->next;
		} else {
			netfront_release_rxbuffer(dev->rx_buffers[id], dev);
		}
#endif

		dprintk("rx: ring: len %d %s %s\n", size,
			(flags & NETRXF_more_data ? "(more true) ": ""),
			(drop ? "DROP" : ""));
	}

	BUG_ON(slots > dev->rx.sring->rsp_prod - dev->rx.rsp_cons);
	dev->rx.rsp_cons = cons + slots;

	if (unlikely(drop))
		goto err_drop;

#ifdef HAVE_LWIP
	if (likely(dev->netif_rx_pbuf)) {
#if ETH_PAD_SIZE
		pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
#endif /* ETH_PAD_SIZE */
		if (first_p->ref != 1)
		  printk("first_p->ref = %u\n", first_p->ref);
		dev->netif_rx_pbuf(first_p, dev->netif_rx_arg);
	}
#endif /* HAVE_LWIP */
	return 1;

 err_drop:
	dprintk("  rx: dropped\n");
#ifdef HAVE_LWIP
	if (first_p) {
#ifdef CONFIG_NETFRONT_PERSISTENT_GRANTS
		pbuf_free(first_p);
#else /* CONFIG_NETFRONT_PERSISTENT_GRANTS */
		struct pbuf *next;

		/* unchain pbuf and release */
		p = first_p;
		while (p != NULL) {
			next = p->next;
			p->tot_len = p->len;
			p->next = NULL;
			netfront_free_rxpbuf(p);
			p = next;
		}
#endif /* CONFIG_NETFRONT_PERSISTENT_GRANTS */
	}
	if (likely(dev->netif_rx_pbuf))
		dev->netif_rx_pbuf(NULL, dev->netif_rx_arg); /* notify drop */
#endif
	return 0;
}
Example #7
0
/**
 * Called from ip_input() if a new IGMP packet is received.
 *
 * @param p received igmp packet, p->payload pointing to the ip header
 * @param inp network interface on which the packet was received
 * @param dest destination ip address of the igmp packet
 */
void
igmp_input(struct pbuf *p, struct netif *inp, struct ip_addr *dest)
{
  struct ip_hdr *    iphdr;
  struct igmp_msg*   igmp;
  struct igmp_group* group;
  struct igmp_group* groupref;

  /* Note that the length CAN be greater than 8 but only 8 are used - All are included in the checksum */    
  iphdr = p->payload;
  if (pbuf_header(p, -(s16_t)(IPH_HL(iphdr) * 4)) || (p->len < IGMP_MINLEN)) {
    pbuf_free(p);
    IGMP_STATS_INC(igmp.lenerr);
    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: length error\n"));
    return;
  }

  LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: message from "));
  ip_addr_debug_print(IGMP_DEBUG, &(iphdr->src));
  LWIP_DEBUGF(IGMP_DEBUG, (" to address "));
  ip_addr_debug_print(IGMP_DEBUG, &(iphdr->dest));
  LWIP_DEBUGF(IGMP_DEBUG, (" on if %x\n", (int) inp));

  /* Now calculate and check the checksum */
  igmp = (struct igmp_msg *)p->payload;
  if (inet_chksum(igmp, p->len)) {
    pbuf_free(p);
    IGMP_STATS_INC(igmp.chkerr);
    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: checksum error\n"));
    return;
  }

  /* Packet is ok so find an existing group */
  group = igmp_lookfor_group(inp, dest); /* use the incoming IP address! */
  
  /* If group can be found or create... */
  if (!group) {
    pbuf_free(p);
    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP frame not for us\n"));
    return;
  }

  /* NOW ACT ON THE INCOMING MESSAGE TYPE... */
  switch (igmp->igmp_msgtype) {
   case IGMP_MEMB_QUERY: {
     /* IGMP_MEMB_QUERY to the "all systems" address ? */
     if ((ip_addr_cmp(dest, &allsystems)) && (igmp->igmp_group_address.addr == 0)) {
       /* THIS IS THE GENERAL QUERY */
       LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: General IGMP_MEMB_QUERY on \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));

       if (igmp->igmp_maxresp == 0) {
         IGMP_STATS_INC(igmp.v1_rxed);
         LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: got an all hosts query with time== 0 - this is V1 and not implemented - treat as v2\n"));
         igmp->igmp_maxresp = IGMP_V1_DELAYING_MEMBER_TMR;
       }

       IGMP_STATS_INC(igmp.group_query_rxed);
       groupref = igmp_group_list;
       while (groupref) {
         /* Do not send messages on the all systems group address! */
         if ((groupref->interface == inp) && (!(ip_addr_cmp(&(groupref->group_address), &allsystems)))) {
           igmp_delaying_member( groupref, igmp->igmp_maxresp);
         }
         groupref = groupref->next;
       }
     } else {
       /* IGMP_MEMB_QUERY to a specific group ? */
       if (group->group_address.addr != 0) {
         LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_MEMB_QUERY to a specific group "));
         ip_addr_debug_print(IGMP_DEBUG, &group->group_address);
         if (ip_addr_cmp (dest, &allsystems)) {
           LWIP_DEBUGF(IGMP_DEBUG, (" using \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));
           /* we first need to re-lookfor the group since we used dest last time */
           group = igmp_lookfor_group(inp, &igmp->igmp_group_address);
         } else {
           LWIP_DEBUGF(IGMP_DEBUG, (" with the group address as destination [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));
         }

         if (group != NULL) {
           IGMP_STATS_INC(igmp.unicast_query);
           igmp_delaying_member( group, igmp->igmp_maxresp);
         }
       }
     }
     break;
   }
   case IGMP_V2_MEMB_REPORT: {
     LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_V2_MEMB_REPORT\n"));

     IGMP_STATS_INC(igmp.report_rxed);
     if (group->group_state == IGMP_GROUP_DELAYING_MEMBER) {
       /* This is on a specific group we have already looked up */
       group->timer = 0; /* stopped */
       group->group_state = IGMP_GROUP_IDLE_MEMBER;
       group->last_reporter_flag = 0;
     }
     break;
   }
   default: {
     LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: unexpected msg %x in state %x on group %x on if %x\n", (int) igmp->igmp_msgtype, (int) group->group_state, (int) &group, (int) group->interface));
     break;
   }
  }

  pbuf_free(p);
  return;
}
/**
 * Reassembles incoming IPv6 fragments into an IPv6 datagram.
 *
 * @param p points to the IPv6 Fragment Header
 * @param len the length of the payload (after Fragment Header)
 * @return NULL if reassembly is incomplete, pbuf pointing to
 *         IPv6 Header if reassembly is complete
 */
struct pbuf *
ip6_reass(struct pbuf *p)
{
  struct ip6_reassdata *ipr, *ipr_prev;
  struct ip6_reass_helper *iprh, *iprh_tmp, *iprh_prev=NULL;
  struct ip6_frag_hdr * frag_hdr;
  u16_t offset, len;
  u8_t clen, valid = 1;
  struct pbuf *q;

  IP6_FRAG_STATS_INC(ip6_frag.recv);

  LWIP_ASSERT("ip6_frag_hdr must be in the first pbuf, not chained",
     (const void*)ip6_current_header() == ((u8_t*)p->payload) - IP6_HLEN);

  frag_hdr = (struct ip6_frag_hdr *) p->payload;

  clen = pbuf_clen(p);

  offset = ntohs(frag_hdr->_fragment_offset);

  /* Calculate fragment length from IPv6 payload length.
   * Adjust for headers before Fragment Header.
   * And finally adjust by Fragment Header length. */
  len = ntohs(ip6_current_header()->_plen);
  len -= (u16_t)(((u8_t*)p->payload - (const u8_t*)ip6_current_header()) - IP6_HLEN);
  len -= IP6_FRAG_HLEN;

  /* Look for the datagram the fragment belongs to in the current datagram queue,
   * remembering the previous in the queue for later dequeueing. */
  for (ipr = reassdatagrams, ipr_prev = NULL; ipr != NULL; ipr = ipr->next) {
    /* Check if the incoming fragment matches the one currently present
       in the reassembly buffer. If so, we proceed with copying the
       fragment into the buffer. */
    if ((frag_hdr->_identification == ipr->identification) &&
        ip6_addr_cmp(ip6_current_src_addr(), &(IPV6_FRAG_HDRREF(ipr->iphdr)->src)) &&
        ip6_addr_cmp(ip6_current_dest_addr(), &(IPV6_FRAG_HDRREF(ipr->iphdr)->dest))) {
      IP6_FRAG_STATS_INC(ip6_frag.cachehit);
      break;
    }
    ipr_prev = ipr;
  }

  if (ipr == NULL) {
  /* Enqueue a new datagram into the datagram queue */
    ipr = (struct ip6_reassdata *)memp_malloc(MEMP_IP6_REASSDATA);
    if (ipr == NULL) {
#if IP_REASS_FREE_OLDEST
      /* Make room and try again. */
      ip6_reass_remove_oldest_datagram(ipr, clen);
      ipr = (struct ip6_reassdata *)memp_malloc(MEMP_IP6_REASSDATA);
      if (ipr != NULL) {
        /* re-search ipr_prev since it might have been removed */
        for (ipr_prev = reassdatagrams; ipr_prev != NULL; ipr_prev = ipr_prev->next) {
          if (ipr_prev->next == ipr) {
            break;
          }
        }
      } else
#endif /* IP_REASS_FREE_OLDEST */
      {
        IP6_FRAG_STATS_INC(ip6_frag.memerr);
        IP6_FRAG_STATS_INC(ip6_frag.drop);
        goto nullreturn;
      }
    }

    memset(ipr, 0, sizeof(struct ip6_reassdata));
    ipr->timer = IP_REASS_MAXAGE;

    /* enqueue the new structure to the front of the list */
    ipr->next = reassdatagrams;
    reassdatagrams = ipr;

    /* Use the current IPv6 header for src/dest address reference.
     * Eventually, we will replace it when we get the first fragment
     * (it might be this one, in any case, it is done later). */
#if IPV6_FRAG_COPYHEADER
    MEMCPY(&ipr->iphdr, ip6_current_header(), IP6_HLEN);
#else /* IPV6_FRAG_COPYHEADER */
    /* need to use the none-const pointer here: */
    ipr->iphdr = ip_data.current_ip6_header;
#endif /* IPV6_FRAG_COPYHEADER */

    /* copy the fragmented packet id. */
    ipr->identification = frag_hdr->_identification;

    /* copy the nexth field */
    ipr->nexth = frag_hdr->_nexth;
  }

  /* Check if we are allowed to enqueue more datagrams. */
  if ((ip6_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) {
#if IP_REASS_FREE_OLDEST
    ip6_reass_remove_oldest_datagram(ipr, clen);
    if ((ip6_reass_pbufcount + clen) <= IP_REASS_MAX_PBUFS) {
      /* re-search ipr_prev since it might have been removed */
      for (ipr_prev = reassdatagrams; ipr_prev != NULL; ipr_prev = ipr_prev->next) {
        if (ipr_prev->next == ipr) {
          break;
        }
      }
    } else
#endif /* IP_REASS_FREE_OLDEST */
    {
      /* @todo: send ICMPv6 time exceeded here? */
      /* drop this pbuf */
      IP6_FRAG_STATS_INC(ip6_frag.memerr);
      IP6_FRAG_STATS_INC(ip6_frag.drop);
      goto nullreturn;
    }
  }

  /* Overwrite Fragment Header with our own helper struct. */
#if IPV6_FRAG_COPYHEADER
  if (IPV6_FRAG_REQROOM > 0) {
    /* Make room for struct ip6_reass_helper (only required if sizeof(void*) > 4).
       This cannot fail since we already checked when receiving this fragment. */
    err_t hdrerr = pbuf_header_force(p, IPV6_FRAG_REQROOM);
    LWIP_ASSERT("no room for struct ip6_reass_helper", hdrerr == ERR_OK);
  }
#else /* IPV6_FRAG_COPYHEADER */
  LWIP_ASSERT("sizeof(struct ip6_reass_helper) <= IP6_FRAG_HLEN, set IPV6_FRAG_COPYHEADER to 1",
    sizeof(struct ip6_reass_helper) <= IP6_FRAG_HLEN);
#endif /* IPV6_FRAG_COPYHEADER */
  iprh = (struct ip6_reass_helper *)p->payload;
  iprh->next_pbuf = NULL;
  iprh->start = (offset & IP6_FRAG_OFFSET_MASK);
  iprh->end = (offset & IP6_FRAG_OFFSET_MASK) + len;

  /* find the right place to insert this pbuf */
  /* Iterate through until we either get to the end of the list (append),
   * or we find on with a larger offset (insert). */
  for (q = ipr->p; q != NULL;) {
    iprh_tmp = (struct ip6_reass_helper*)q->payload;
    if (iprh->start < iprh_tmp->start) {
#if IP_REASS_CHECK_OVERLAP
      if (iprh->end > iprh_tmp->start) {
        /* fragment overlaps with following, throw away */
        IP6_FRAG_STATS_INC(ip6_frag.proterr);
        IP6_FRAG_STATS_INC(ip6_frag.drop);
        goto nullreturn;
      }
      if (iprh_prev != NULL) {
        if (iprh->start < iprh_prev->end) {
          /* fragment overlaps with previous, throw away */
          IP6_FRAG_STATS_INC(ip6_frag.proterr);
          IP6_FRAG_STATS_INC(ip6_frag.drop);
          goto nullreturn;
        }
      }
#endif /* IP_REASS_CHECK_OVERLAP */
      /* the new pbuf should be inserted before this */
      iprh->next_pbuf = q;
      if (iprh_prev != NULL) {
        /* not the fragment with the lowest offset */
        iprh_prev->next_pbuf = p;
      } else {
        /* fragment with the lowest offset */
        ipr->p = p;
      }
      break;
    } else if (iprh->start == iprh_tmp->start) {
      /* received the same datagram twice: no need to keep the datagram */
      IP6_FRAG_STATS_INC(ip6_frag.drop);
      goto nullreturn;
#if IP_REASS_CHECK_OVERLAP
    } else if (iprh->start < iprh_tmp->end) {
      /* overlap: no need to keep the new datagram */
      IP6_FRAG_STATS_INC(ip6_frag.proterr);
      IP6_FRAG_STATS_INC(ip6_frag.drop);
      goto nullreturn;
#endif /* IP_REASS_CHECK_OVERLAP */
    } else {
      /* Check if the fragments received so far have no gaps. */
      if (iprh_prev != NULL) {
        if (iprh_prev->end != iprh_tmp->start) {
          /* There is a fragment missing between the current
           * and the previous fragment */
          valid = 0;
        }
      }
    }
    q = iprh_tmp->next_pbuf;
    iprh_prev = iprh_tmp;
  }

  /* If q is NULL, then we made it to the end of the list. Determine what to do now */
  if (q == NULL) {
    if (iprh_prev != NULL) {
      /* this is (for now), the fragment with the highest offset:
       * chain it to the last fragment */
#if IP_REASS_CHECK_OVERLAP
      LWIP_ASSERT("check fragments don't overlap", iprh_prev->end <= iprh->start);
#endif /* IP_REASS_CHECK_OVERLAP */
      iprh_prev->next_pbuf = p;
      if (iprh_prev->end != iprh->start) {
        valid = 0;
      }
    } else {
#if IP_REASS_CHECK_OVERLAP
      LWIP_ASSERT("no previous fragment, this must be the first fragment!",
        ipr->p == NULL);
#endif /* IP_REASS_CHECK_OVERLAP */
      /* this is the first fragment we ever received for this ip datagram */
      ipr->p = p;
    }
  }

  /* Track the current number of pbufs current 'in-flight', in order to limit
  the number of fragments that may be enqueued at any one time */
  ip6_reass_pbufcount += clen;

  /* Remember IPv6 header if this is the first fragment. */
  if (iprh->start == 0) {
#if IPV6_FRAG_COPYHEADER
    if (iprh->next_pbuf != NULL) {
      MEMCPY(&ipr->iphdr, ip6_current_header(), IP6_HLEN);
    }
#else /* IPV6_FRAG_COPYHEADER */
    /* need to use the none-const pointer here: */
    ipr->iphdr = ip_data.current_ip6_header;
#endif /* IPV6_FRAG_COPYHEADER */
  }

  /* If this is the last fragment, calculate total packet length. */
  if ((offset & IP6_FRAG_MORE_FLAG) == 0) {
    ipr->datagram_len = iprh->end;
  }

  /* Additional validity tests: we have received first and last fragment. */
  iprh_tmp = (struct ip6_reass_helper*)ipr->p->payload;
  if (iprh_tmp->start != 0) {
    valid = 0;
  }
  if (ipr->datagram_len == 0) {
    valid = 0;
  }

  /* Final validity test: no gaps between current and last fragment. */
  iprh_prev = iprh;
  q = iprh->next_pbuf;
  while ((q != NULL) && valid) {
    iprh = (struct ip6_reass_helper*)q->payload;
    if (iprh_prev->end != iprh->start) {
      valid = 0;
      break;
    }
    iprh_prev = iprh;
    q = iprh->next_pbuf;
  }

  if (valid) {
    /* All fragments have been received */
    struct ip6_hdr* iphdr_ptr;

    /* chain together the pbufs contained within the ip6_reassdata list. */
    iprh = (struct ip6_reass_helper*) ipr->p->payload;
    while (iprh != NULL) {
      struct pbuf* next_pbuf = iprh->next_pbuf;
      if (next_pbuf != NULL) {
        /* Save next helper struct (will be hidden in next step). */
        iprh_tmp = (struct ip6_reass_helper*)next_pbuf->payload;

        /* hide the fragment header for every succeeding fragment */
        pbuf_header(next_pbuf, -IP6_FRAG_HLEN);
#if IPV6_FRAG_COPYHEADER
        if (IPV6_FRAG_REQROOM > 0) {
          /* hide the extra bytes borrowed from ip6_hdr for struct ip6_reass_helper */
          err_t hdrerr = pbuf_header(next_pbuf, -(s16_t)(IPV6_FRAG_REQROOM));
          LWIP_ASSERT("no room for struct ip6_reass_helper", hdrerr == ERR_OK);
        }
#endif
        pbuf_cat(ipr->p, next_pbuf);
      }
      else {
        iprh_tmp = NULL;
      }

      iprh = iprh_tmp;
    }

#if IPV6_FRAG_COPYHEADER
    if (IPV6_FRAG_REQROOM > 0) {
      /* get back room for struct ip6_reass_helper (only required if sizeof(void*) > 4) */
      err_t hdrerr = pbuf_header(ipr->p, -(s16_t)(IPV6_FRAG_REQROOM));
      LWIP_ASSERT("no room for struct ip6_reass_helper", hdrerr == ERR_OK);
    }
    iphdr_ptr = (struct ip6_hdr*)((u8_t*)ipr->p->payload - IP6_HLEN);
    MEMCPY(iphdr_ptr, &ipr->iphdr, IP6_HLEN);
#else
    iphdr_ptr = ipr->iphdr;
#endif

    /* Adjust datagram length by adding header lengths. */
    ipr->datagram_len += (u16_t)(((u8_t*)ipr->p->payload - (u8_t*)iphdr_ptr)
                         + IP6_FRAG_HLEN
                         - IP6_HLEN);

    /* Set payload length in ip header. */
    iphdr_ptr->_plen = htons(ipr->datagram_len);

    /* Get the first pbuf. */
    p = ipr->p;

    /* Restore Fragment Header in first pbuf. Mark as "single fragment"
     * packet. Restore nexth. */
    frag_hdr = (struct ip6_frag_hdr *) p->payload;
    frag_hdr->_nexth = ipr->nexth;
    frag_hdr->reserved = 0;
    frag_hdr->_fragment_offset = 0;
    frag_hdr->_identification = 0;

    /* release the sources allocate for the fragment queue entry */
    if (reassdatagrams == ipr) {
      /* it was the first in the list */
      reassdatagrams = ipr->next;
    } else {
      /* it wasn't the first, so it must have a valid 'prev' */
      LWIP_ASSERT("sanity check linked list", ipr_prev != NULL);
      ipr_prev->next = ipr->next;
    }
    memp_free(MEMP_IP6_REASSDATA, ipr);

    /* adjust the number of pbufs currently queued for reassembly. */
    ip6_reass_pbufcount -= pbuf_clen(p);

    /* Move pbuf back to IPv6 header.
       This cannot fail since we already checked when receiving this fragment. */
    if (pbuf_header_force(p, (s16_t)((u8_t*)p->payload - (u8_t*)iphdr_ptr))) {
      LWIP_ASSERT("ip6_reass: moving p->payload to ip6 header failed\n", 0);
      pbuf_free(p);
      return NULL;
    }

    /* Return the pbuf chain */
    return p;
  }
  /* the datagram is not (yet?) reassembled completely */
  return NULL;

nullreturn:
  pbuf_free(p);
  return NULL;
}
Example #9
0
/**
 * Send the raw IP packet to the given address. Note that actually you cannot
 * modify the IP headers (this is inconsistent with the receive callback where
 * you actually get the IP headers), you can only specify the IP payload here.
 * It requires some more changes in lwIP. (there will be a raw_send() function
 * then.)
 *
 * @param pcb the raw pcb which to send
 * @param p the IP payload to send
 * @param ipaddr the destination address of the IP packet
 *
 */
err_t raw_sendto(struct raw_pcb *pcb, struct pbuf *p, ip_addr_t *ipaddr) {
  err_t err;
  struct netif *netif;
  ip_addr_t *src_ip;
  struct pbuf *q; /* q will be sent down the stack */

  LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_sendto\n"));

  /* not enough space to add an IP header to first pbuf in given p chain? */
  if (pbuf_header(p, IP_HLEN)) {
    /* allocate header in new pbuf */
    q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM);
    /* new header pbuf could not be allocated? */
    if (q == NULL) {
      LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
                  ("raw_sendto: could not allocate header\n"));
      return ERR_MEM;
    }
    if (p->tot_len != 0) {
      /* chain header q in front of given pbuf p */
      pbuf_chain(q, p);
    }
    /* { first pbuf q points to header pbuf } */
    LWIP_DEBUGF(RAW_DEBUG,
                ("raw_sendto: added header pbuf %p before given pbuf %p\n",
                 (void *) q, (void *) p));
  } else {
    /* first pbuf q equals given pbuf */
    q = p;
    if (pbuf_header(q, -IP_HLEN)) {
      LWIP_ASSERT("Can't restore header we just removed!", 0);
      return ERR_MEM;
    }
  }

  if ((netif = ip_route(ipaddr)) == NULL) {
    LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING,
                ("raw_sendto: No route to %" U16_F ".%" U16_F ".%" U16_F
                 ".%" U16_F "\n",
                 ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr),
                 ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
    /* free any temporary header pbuf allocated by pbuf_header() */
    if (q != p) {
      pbuf_free(q);
    }
    return ERR_RTE;
  }

#if IP_SOF_BROADCAST
  /* broadcast filter? */
  if (!ip_get_option(pcb, SOF_BROADCAST) &&
      ip_addr_isbroadcast(ipaddr, netif)) {
    LWIP_DEBUGF(
        RAW_DEBUG | LWIP_DBG_LEVEL_WARNING,
        ("raw_sendto: SOF_BROADCAST not enabled on pcb %p\n", (void *) pcb));
    /* free any temporary header pbuf allocated by pbuf_header() */
    if (q != p) {
      pbuf_free(q);
    }
    return ERR_VAL;
  }
#endif /* IP_SOF_BROADCAST */

  if (ip_addr_isany(&pcb->local_ip)) {
    /* use outgoing network interface IP address as source address */
    src_ip = &(netif->ip_addr);
  } else {
    /* use RAW PCB local IP address as source address */
    src_ip = &(pcb->local_ip);
  }

  NETIF_SET_HWADDRHINT(netif, &pcb->addr_hint);
  err =
      ip_output_if(q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif);
  NETIF_SET_HWADDRHINT(netif, NULL);

  /* did we chain a header earlier? */
  if (q != p) {
    /* free the header */
    pbuf_free(q);
  }
  return err;
}
Example #10
0
/*-----------------------------------------------------------------------------------*/
void
udp_input(struct pbuf *p, struct netif *inp)
{
  struct udp_hdr *udphdr;  
  struct udp_pcb *pcb;
  struct ip_hdr *iphdr;
  uint16_t src, dest;
  
  
#ifdef UDP_STATS
  ++stats.udp.recv;
#endif /* UDP_STATS */

  iphdr = p->payload;

  pbuf_header(p, -(UDP_HLEN + IPH_HL(iphdr) * 4));

  udphdr = (struct udp_hdr *)((uint8_t *)p->payload - UDP_HLEN);
  
  DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %d\n", p->tot_len));
	
  src = NTOHS(udphdr->src);
  dest = NTOHS(udphdr->dest);

#if UDP_DEBUG
  udp_debug_print(udphdr);
#endif /* UDP_DEBUG */
  
  /* Demultiplex packet. First, go for a perfect match. */
  for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
    DEBUGF(UDP_DEBUG, ("udp_input: pcb local port %d (dgram %d)\n",
		       pcb->local_port, ntohs(udphdr->dest)));
    if(pcb->remote_port == src &&
       pcb->local_port == dest &&
       (ip_addr_isany(&pcb->remote_ip) ||
	ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) &&
       (ip_addr_isany(&pcb->local_ip) ||
	ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) {
      break;
    }
  }

  if(pcb == NULL) {
    for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
      DEBUGF(UDP_DEBUG, ("udp_input: pcb local port %d (dgram %d)\n",
			 pcb->local_port, dest));
      if(pcb->local_port == dest &&
	 (ip_addr_isany(&pcb->remote_ip) ||
	  ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) &&
	 (ip_addr_isany(&pcb->local_ip) ||
	  ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) {
	break;
      }      
    }
  }


  /* Check checksum if this is a match or if it was directed at us. */
  /*  if(pcb != NULL ||
      ip_addr_cmp(&inp->ip_addr, &iphdr->dest)) {*/
  if(pcb != NULL) {
    DEBUGF(UDP_DEBUG, ("udp_input: calculating checksum\n"));
    pbuf_header(p, UDP_HLEN);    
#ifdef IPv6
    if(iphdr->nexthdr == IP_PROTO_UDPLITE) {    
#else
    if(IPH_PROTO(iphdr) == IP_PROTO_UDPLITE) {    
#endif /* IPv4 */
      /* Do the UDP Lite checksum */
      if(inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src),
			    (struct ip_addr *)&(iphdr->dest),
			    IP_PROTO_UDPLITE, ntohs(udphdr->len)) != 0) {
	DEBUGF(UDP_DEBUG, ("udp_input: UDP Lite datagram discarded due to failing checksum\n"));
#ifdef UDP_STATS
	++stats.udp.chkerr;
	++stats.udp.drop;
#endif /* UDP_STATS */
	pbuf_free(p);
	goto end;
      }
    } else {
      if(udphdr->chksum != 0) {
	if(inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src),
			      (struct ip_addr *)&(iphdr->dest),
			      IP_PROTO_UDP, p->tot_len) != 0) {
	  DEBUGF(UDP_DEBUG, ("udp_input: UDP datagram discarded due to failing checksum\n"));
	  
#ifdef UDP_STATS
	  ++stats.udp.chkerr;
	  ++stats.udp.drop;
#endif /* UDP_STATS */
	  pbuf_free(p);
	  goto end;
	}
      }
    }
    pbuf_header(p, -UDP_HLEN);    
    if(pcb != NULL) {
      pcb->recv(pcb->recv_arg, pcb, p, &(iphdr->src), src);
    } else {
      DEBUGF(UDP_DEBUG, ("udp_input: not for us.\n"));
      
      /* No match was found, send ICMP destination port unreachable unless
	 destination address was broadcast/multicast. */
      
      if(!ip_addr_isbroadcast(&iphdr->dest, &inp->netmask) &&
	 !ip_addr_ismulticast(&iphdr->dest)) {
	
	/* deconvert from host to network byte order */
	udphdr->src = htons(udphdr->src);
	udphdr->dest = htons(udphdr->dest); 
	
	/* adjust pbuf pointer */
	p->payload = iphdr;
	icmp_dest_unreach(p, ICMP_DUR_PORT);
      }
#ifdef UDP_STATS
      ++stats.udp.proterr;
      ++stats.udp.drop;
#endif /* UDP_STATS */
      pbuf_free(p);
    }
  } else {
    pbuf_free(p);
  }

  end:
	while(0); /* hack to remove compiler warning */
	
}
/*-----------------------------------------------------------------------------------*/
err_t
udp_send(struct udp_pcb *pcb, struct pbuf *p)
{
  struct udp_hdr *udphdr;
  struct ip_addr *src_ip;
  err_t err;
  struct pbuf *q;
  
  if(pbuf_header(p, UDP_HLEN)) {
    q = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM);
    if(q == NULL) {
      return ERR_MEM;
    }
    pbuf_chain(q, p);
    p = q;
  }

  udphdr = p->payload;
  udphdr->src = htons(pcb->local_port);
  udphdr->dest = htons(pcb->remote_port);
  udphdr->chksum = 0x0000;

  src_ip = &(pcb->local_ip);
  
  DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %d\n", p->tot_len));
  
  if(pcb->flags & UDP_FLAGS_UDPLITE) {
    udphdr->len = htons(pcb->chksum_len);
    /* calculate checksum */
    udphdr->chksum = inet_chksum_pseudo(p, src_ip, &(pcb->remote_ip),
					IP_PROTO_UDP, pcb->chksum_len);
    if(udphdr->chksum == 0x0000) {
      udphdr->chksum = 0xffff;
    }
    err = sr_lwip_output(p, &pcb->local_ip, &pcb->remote_ip, IP_PROTO_UDPLITE);
  } else {
    udphdr->len = htons(p->tot_len);
    /* calculate checksum */
    if((pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) {
      udphdr->chksum = inet_chksum_pseudo(p, src_ip, &pcb->remote_ip,
					  IP_PROTO_UDP, p->tot_len);
      if(udphdr->chksum == 0x0000) {
	udphdr->chksum = 0xffff;
      }
    }
    err = sr_lwip_output(p,&pcb->local_ip, &pcb->remote_ip, IP_PROTO_UDP);
  }
  
#ifdef UDP_STATS
  ++stats.udp.xmit;
#endif /* UDP_STATS */
  return err;
}
/*-----------------------------------------------------------------------------------*/
err_t
udp_bind(struct udp_pcb *pcb, struct ip_addr *ipaddr, uint16_t port)
{
  struct udp_pcb *ipcb;
  ip_addr_set(&pcb->local_ip, ipaddr);
  pcb->local_port = port;

  /* Insert UDP PCB into the list of active UDP PCBs. */
  for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
    if(pcb == ipcb) {
      /* Already on the list, just return. */
      return ERR_OK;
    }
  }
  /* We need to place the PCB on the list. */
  pcb->next = udp_pcbs;
  udp_pcbs = pcb;

  DEBUGF(UDP_DEBUG, ("udp_bind: bound to port %d\n", port));
  return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
err_t
udp_connect(struct udp_pcb *pcb, struct ip_addr *ipaddr, uint16_t port)
{
  struct udp_pcb *ipcb;
  ip_addr_set(&pcb->remote_ip, ipaddr);
  pcb->remote_port = port;

  /* Insert UDP PCB into the list of active UDP PCBs. */
  for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
    if(pcb == ipcb) {
      /* Already on the list, just return. */
      return ERR_OK;
    }
  }
  /* We need to place the PCB on the list. */
  pcb->next = udp_pcbs;
  udp_pcbs = pcb;
  return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
void
udp_recv(struct udp_pcb *pcb,
	 void (* recv)(void *arg, struct udp_pcb *upcb, struct pbuf *p,
		       struct ip_addr *addr, uint16_t port),
	 void *recv_arg)
{
  pcb->recv = recv;
  pcb->recv_arg = recv_arg;
}
Example #11
0
/*-----------------------------------------------------------------------------------*/
void
tcpdump(struct pbuf *p)
{
  struct ip_hdr *iphdr;
  struct tcp_hdr *tcphdr;
#if LWIP_UDP
  struct udp_hdr *udphdr;
#endif
  char flags[5];
  int i;
  int len;
  int offset;

  if (file == NULL) {
    return;
  }
#ifdef IPv4
  iphdr = (struct ip_hdr *)p->payload;
  switch (IPH_PROTO(iphdr)) {
#if LWIP_TCP
  case IP_PROTO_TCP:
    tcphdr = (struct tcp_hdr *)((char *)iphdr + IP_HLEN);

    pbuf_header(p, -IP_HLEN);
    if (inet_chksum_pseudo(p, (ip_addr_t *)&(iphdr->src),
			  (ip_addr_t *)&(iphdr->dest),
			  IP_PROTO_TCP, p->tot_len) != 0) {
      LWIP_DEBUGF(TCPDUMP_DEBUG, ("tcpdump: IP checksum failed!\n"));
      /*    fprintf(file, "chksum 0x%lx ", tcphdr->chksum);
	    tcphdr->chksum = 0;
	    fprintf(file, "should be 0x%lx ", inet_chksum_pseudo(p, (ip_addr_t *)&(iphdr->src),
	    (ip_addr_t *)&(iphdr->dest),
	    IP_PROTO_TCP, p->tot_len));*/
      fprintf(file, "!chksum ");
    }

    i = 0;
    if (TCPH_FLAGS(tcphdr) & TCP_SYN) {
      flags[i++] = 'S';
    }
    if (TCPH_FLAGS(tcphdr) & TCP_PSH) {
      flags[i++] = 'P';
    }
    if (TCPH_FLAGS(tcphdr) & TCP_FIN) {
      flags[i++] = 'F';
    }
    if (TCPH_FLAGS(tcphdr) & TCP_RST) {
      flags[i++] = 'R';
    }
    if (i == 0) {
      flags[i++] = '.';
    }
    flags[i++] = 0;



    fprintf(file, "%d.%d.%d.%d.%u > %d.%d.%d.%d.%u: ",
	    (int)(ntohl(iphdr->src.addr) >> 24) & 0xff,
	    (int)(ntohl(iphdr->src.addr) >> 16) & 0xff,
	    (int)(ntohl(iphdr->src.addr) >> 8) & 0xff,
	    (int)(ntohl(iphdr->src.addr) >> 0) & 0xff,
	    ntohs(tcphdr->src),
	  (int)(ntohl(iphdr->dest.addr) >> 24) & 0xff,
	    (int)(ntohl(iphdr->dest.addr) >> 16) & 0xff,
	    (int)(ntohl(iphdr->dest.addr) >> 8) & 0xff,
	    (int)(ntohl(iphdr->dest.addr) >> 0) & 0xff,
	    ntohs(tcphdr->dest));
    offset = TCPH_HDRLEN(tcphdr);

    len = ntohs(IPH_LEN(iphdr)) - offset * 4 - IP_HLEN;
    if (len != 0 || flags[0] != '.') {
      fprintf(file, "%s %u:%u(%u) ",
	      flags,
	      ntohl(tcphdr->seqno),
	      ntohl(tcphdr->seqno) + len,
	      len);
    }
    if (TCPH_FLAGS(tcphdr) & TCP_ACK) {
      fprintf(file, "ack %u ",
	      ntohl(tcphdr->ackno));
    }
    fprintf(file, "wnd %u\n",
	    ntohs(tcphdr->wnd));

    fflush(file);

    pbuf_header(p, IP_HLEN);
    break;
#endif /* LWIP_TCP */

#if LWIP_UDP
  case IP_PROTO_UDP:
    udphdr = (struct udp_hdr *)((char *)iphdr + IP_HLEN);

    pbuf_header(p, -IP_HLEN);
    if (inet_chksum_pseudo(p, (ip_addr_t *)&(iphdr->src),
			  (ip_addr_t *)&(iphdr->dest),
			  IP_PROTO_UDP, p->tot_len) != 0) {
      LWIP_DEBUGF(TCPDUMP_DEBUG, ("tcpdump: IP checksum failed!\n"));
      /*    fprintf(file, "chksum 0x%lx ", tcphdr->chksum);
	    tcphdr->chksum = 0;
	    fprintf(file, "should be 0x%lx ", inet_chksum_pseudo(p, (ip_addr_t *)&(iphdr->src),
	    (ip_addr_t *)&(iphdr->dest),
	    IP_PROTO_TCP, p->tot_len));*/
      fprintf(file, "!chksum ");
    }

    fprintf(file, "%d.%d.%d.%d.%u > %d.%d.%d.%d.%u: ",
	    (int)(ntohl(iphdr->src.addr) >> 24) & 0xff,
	    (int)(ntohl(iphdr->src.addr) >> 16) & 0xff,
	    (int)(ntohl(iphdr->src.addr) >> 8) & 0xff,
	    (int)(ntohl(iphdr->src.addr) >> 0) & 0xff,
	    ntohs(udphdr->src),
	  (int)(ntohl(iphdr->dest.addr) >> 24) & 0xff,
	    (int)(ntohl(iphdr->dest.addr) >> 16) & 0xff,
	    (int)(ntohl(iphdr->dest.addr) >> 8) & 0xff,
	    (int)(ntohl(iphdr->dest.addr) >> 0) & 0xff,
	    ntohs(udphdr->dest));
    fprintf(file, "U ");
    len = ntohs(IPH_LEN(iphdr)) - sizeof(struct udp_hdr) - IP_HLEN;
    fprintf(file, " %d\n", len);

    fflush(file);

    pbuf_header(p, IP_HLEN);
    break;
#endif /* LWIP_UDP */
  default:
    LWIP_DEBUGF(TCPDUMP_DEBUG, ("unhandled IP protocol: %d\n", (int)IPH_PROTO(iphdr)));
    break;

  }
#endif /* IPv4 */
}
Example #12
0
/**
 * This function is called by the network interface device driver when
 * an IP packet is received. The function does the basic checks of the
 * IP header such as packet size being at least larger than the header
 * size etc. If the packet was not destined for us, the packet is
 * forwarded (using ip_forward). The IP checksum is always checked.
 *
 * Finally, the packet is sent to the upper layer protocol input function.
 * 
 * @param p the received IP packet (p->payload points to IP header)
 * @param inp the netif on which this packet was received
 * @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
 *         processed, but currently always returns ERR_OK)
 */
err_t
ip_input(struct pbuf *p, struct netif *inp)
{
  //static int mytmptest;
  struct ip_hdr *iphdr;
  struct netif *netif;
  u16_t iphdr_hlen;
  u16_t iphdr_len;
#if LWIP_DHCP
  int check_ip_src=1;
#endif /* LWIP_DHCP */

  IP_STATS_INC(ip.recv);
  snmp_inc_ipinreceives();

  /* identify the IP header */
  iphdr = p->payload;
  if (IPH_V(iphdr) != 4) {
    LWIP_DEBUGF(IP_DEBUG | 1, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
    ip_debug_print(p);
    pbuf_free(p);
    IP_STATS_INC(ip.err);
    IP_STATS_INC(ip.drop);
    snmp_inc_ipinhdrerrors();
    return ERR_OK;
  }

  /* obtain IP header length in number of 32-bit words */
  iphdr_hlen = IPH_HL(iphdr);
  /* calculate IP header length in bytes */
  iphdr_hlen *= 4;
  /* obtain ip length in bytes */
  iphdr_len = ntohs(IPH_LEN(iphdr));

  /* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
  if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len)) {
    if (iphdr_hlen > p->len)
    LWIP_DEBUGF(IP_DEBUG | 2, ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
                               iphdr_hlen, p->len));
    if (iphdr_len > p->tot_len)
    LWIP_DEBUGF(IP_DEBUG | 2, ("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), "
                               "IP packet dropped.\n",
                               iphdr_len, p->tot_len));
    /* free (drop) packet pbufs */
    pbuf_free(p);
    IP_STATS_INC(ip.lenerr);
    IP_STATS_INC(ip.drop);
    snmp_inc_ipindiscards();
    return ERR_OK;
  }

  /* verify checksum */
#if CHECKSUM_CHECK_IP
  if (inet_chksum(iphdr, iphdr_hlen) != 0) {

    LWIP_DEBUGF(IP_DEBUG | 2, ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
    ip_debug_print(p);
    pbuf_free(p);
    IP_STATS_INC(ip.chkerr);
    IP_STATS_INC(ip.drop);
    snmp_inc_ipinhdrerrors();
    return ERR_OK;
  }
#endif

  /* Trim pbuf. This should have been done at the netif layer,
   * but we'll do it anyway just to be sure that its done. */
  pbuf_realloc(p, iphdr_len);

  /* match packet against an interface, i.e. is this packet for us? */
#if LWIP_IGMP
  if (ip_addr_ismulticast(&(iphdr->dest))) {
    if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &(iphdr->dest)))) {
      netif = inp;
    } else {
      netif = NULL;
    }
  } else
#endif /* LWIP_IGMP */
  {
    /* start trying with inp. if that's not acceptable, start walking the
       list of configured netifs.
       'first' is used as a boolean to mark whether we started walking the list */
    int first = 1;
    netif = inp;
    do {
      LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest 0x%"X32_F" netif->ip_addr 0x%"X32_F" (0x%"X32_F", 0x%"X32_F", 0x%"X32_F")\n",
          iphdr->dest.addr, netif->ip_addr.addr,
          iphdr->dest.addr & netif->netmask.addr,
          netif->ip_addr.addr & netif->netmask.addr,
          iphdr->dest.addr & ~(netif->netmask.addr)));

      /* interface is up and configured? */
      if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) {
        /* unicast to this interface address? */
        if (ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr)) ||
            /* or broadcast on this interface network address? */
            ip_addr_isbroadcast(&(iphdr->dest), netif)) {
          LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
              netif->name[0], netif->name[1]));
          /* break out of for loop */
          break;
        }
      }
      if (first) {
        first = 0;
        netif = netif_list;
      } else {
        netif = netif->next;
      }
      if (netif == inp) {
        netif = netif->next;
      }
    } while(netif != NULL);
  }

#if LWIP_DHCP
  /* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
   * using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
   * According to RFC 1542 section 3.1.1, referred by RFC 2131).
   */
  if (netif == NULL) {
    /* remote port is DHCP server? */
    if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
      LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | 1, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
        ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen))->dest)));
      if (ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen))->dest) == DHCP_CLIENT_PORT) {
        LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | 1, ("ip_input: DHCP packet accepted.\n"));
        netif = inp;
        check_ip_src = 0;
      }
    }
  }
#endif /* LWIP_DHCP */

  /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
#if LWIP_DHCP
  if (check_ip_src)
#endif /* LWIP_DHCP */
  {  if ((ip_addr_isbroadcast(&(iphdr->src), inp)) ||
         (ip_addr_ismulticast(&(iphdr->src)))) {
      /* packet source is not valid */
      LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | 1, ("ip_input: packet source is not valid.\n"));
      /* free (drop) packet pbufs */
      pbuf_free(p);
      IP_STATS_INC(ip.drop);
      snmp_inc_ipinaddrerrors();
      snmp_inc_ipindiscards();
      return ERR_OK;
    }
  }

  /* packet not for us? */
  if (netif == NULL) {
    /* packet not for us, route or discard */
    LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | 1, ("ip_input: packet not for us.\n"));
#if IP_FORWARD
    /* non-broadcast packet? */
    if (!ip_addr_isbroadcast(&(iphdr->dest), inp)) {
      /* try to forward IP packet on (other) interfaces */
      ip_forward(p, iphdr, inp);
    } else
#endif /* IP_FORWARD */
    {
      snmp_inc_ipinaddrerrors();
      snmp_inc_ipindiscards();
    }
    pbuf_free(p);
    return ERR_OK;
  }
  /* packet consists of multiple fragments? */
  if ((IPH_OFFSET(iphdr) & htons(IP_OFFMASK | IP_MF)) != 0) {
#if IP_REASSEMBLY /* packet fragment reassembly code present? */
    LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04"X16_F" tot_len=%"U16_F" len=%"U16_F" MF=%"U16_F" offset=%"U16_F"), calling ip_reass()\n",
      ntohs(IPH_ID(iphdr)), p->tot_len, ntohs(IPH_LEN(iphdr)), !!(IPH_OFFSET(iphdr) & htons(IP_MF)), (ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)*8));
    /* reassemble the packet*/
    p = ip_reass(p);
    /* packet not fully reassembled yet? */
    if (p == NULL) {
      return ERR_OK;
    }
    iphdr = p->payload;
#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
    pbuf_free(p);
    LWIP_DEBUGF(IP_DEBUG | 2, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
      ntohs(IPH_OFFSET(iphdr))));
    IP_STATS_INC(ip.opterr);
    IP_STATS_INC(ip.drop);
    /* unsupported protocol feature */
    snmp_inc_ipinunknownprotos();
    return ERR_OK;
#endif /* IP_REASSEMBLY */
  }

#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */

#if LWIP_IGMP
  /* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
  if((iphdr_hlen > IP_HLEN &&  (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
#else
  if (iphdr_hlen > IP_HLEN) {
#endif /* LWIP_IGMP */
    LWIP_DEBUGF(IP_DEBUG | 2, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
    pbuf_free(p);
    IP_STATS_INC(ip.opterr);
    IP_STATS_INC(ip.drop);
    /* unsupported protocol feature */
    snmp_inc_ipinunknownprotos();
    return ERR_OK;
  }
#endif /* IP_OPTIONS_ALLOWED == 0 */

  /* send to upper layers */
  
  //acoral_print("\n ip_input.=== %d\n", mytmptest++);
  //acoral_prints("\r\n===ip_input===\r\n");
  
  LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
  ip_debug_print(p);
  LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));

#if LWIP_RAW
  /* raw input did not eat the packet? */
  if (raw_input(p, inp) == 0)
#endif /* LWIP_RAW */
  {
    //acoral_print("\nip proto: %d\n",ntohs((iphdr)->_ttl_proto) & 0xff);
    switch (IPH_PROTO(iphdr)) {
#if LWIP_UDP
    case IP_PROTO_UDP:
#if LWIP_UDPLIT
fE
    case IP_PROTO_UDPLITE:
#endif /* LWIP_UDPLITE */
      snmp_inc_ipindelivers();
      //acoral_prints("\nUDP\n");
      udp_input(p, inp);
      break;
#endif /* LWIP_UDP */
#if LWIP_TCP
    case IP_PROTO_TCP:
      snmp_inc_ipindelivers();
      //acoral_print("\nTCP: tot_len:%d, type:%d\n", p->tot_len, p->type);
      tcp_input(p, inp);
      //acoral_print("\ni am here.=== %d\n", mytmptest++);
      //pbuf_free(p);
      break;
#endif /* LWIP_TCP */
#if LWIP_ICMP
    case IP_PROTO_ICMP:
      snmp_inc_ipindelivers();
      //acoral_prints("\nICMPS\n");
      icmp_input(p, inp);
      //acoral_prints("\nICMPE\n");
      break;
#endif /* LWIP_ICMP */
#if LWIP_IGMP
    case IP_PROTO_IGMP:
      igmp_input(p,inp,&(iphdr->dest));
      break;
#endif /* LWIP_IGMP */
    default:
#if LWIP_ICMP
      /* send ICMP destination protocol unreachable unless is was a broadcast */
      if (!ip_addr_isbroadcast(&(iphdr->dest), inp) &&
          !ip_addr_ismulticast(&(iphdr->dest))) {
        p->payload = iphdr;
        icmp_dest_unreach(p, ICMP_DUR_PROTO);
      }
#endif /* LWIP_ICMP */
      pbuf_free(p);

      LWIP_DEBUGF(IP_DEBUG | 2, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));

      IP_STATS_INC(ip.proterr);
      IP_STATS_INC(ip.drop);
      snmp_inc_ipinunknownprotos();
    }
    
  }
  //acoral_print("\n===  input ok  ===\n");
  return ERR_OK;
}

/**
 * Sends an IP packet on a network interface. This function constructs
 * the IP header and calculates the IP header checksum. If the source
 * IP address is NULL, the IP address of the outgoing network
 * interface is filled in as source address.
 * If the destination IP address is IP_HDRINCL, p is assumed to already
 * include an IP header and p->payload points to it instead of the data.
 *
 * @param p the packet to send (p->payload points to the data, e.g. next
            protocol header; if dest == IP_HDRINCL, p already includes an IP
            header and p->payload points to that IP header)
 * @param src the source IP address to send from (if src == IP_ADDR_ANY, the
 *         IP  address of the netif used to send is used as source address)
 * @param dest the destination IP address to send the packet to
 * @param ttl the TTL value to be set in the IP header
 * @param tos the TOS value to be set in the IP header
 * @param proto the PROTOCOL to be set in the IP header
 * @param netif the netif on which to send this packet
 * @return ERR_OK if the packet was sent OK
 *         ERR_BUF if p doesn't have enough space for IP/LINK headers
 *         returns errors returned by netif->output
 *
 * @note ip_id: RFC791 "some host may be able to simply use
 *  unique identifiers independent of destination"
 */
err_t
ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
             u8_t ttl, u8_t tos,
             u8_t proto, struct netif *netif)
{
  struct ip_hdr *iphdr;
  static u16_t ip_id = 0;

  snmp_inc_ipoutrequests();

  /* Should the IP header be generated or is it already included in p? */
  if (dest != IP_HDRINCL) {
    /* generate IP header */
    if (pbuf_header(p, IP_HLEN)) {
      LWIP_DEBUGF(IP_DEBUG | 2, ("ip_output: not enough room for IP header in pbuf\n"));

      IP_STATS_INC(ip.err);
      snmp_inc_ipoutdiscards();
      return ERR_BUF;
    }

    iphdr = p->payload;
    LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
               (p->len >= sizeof(struct ip_hdr)));

    IPH_TTL_SET(iphdr, ttl);
    IPH_PROTO_SET(iphdr, proto);

    ip_addr_set(&(iphdr->dest), dest);

    IPH_VHLTOS_SET(iphdr, 4, IP_HLEN / 4, tos);
    IPH_LEN_SET(iphdr, htons(p->tot_len));
    IPH_OFFSET_SET(iphdr, 0);
    IPH_ID_SET(iphdr, htons(ip_id));
    ++ip_id;

    if (ip_addr_isany(src)) {
      ip_addr_set(&(iphdr->src), &(netif->ip_addr));
    } else {
      ip_addr_set(&(iphdr->src), src);
    }

    IPH_CHKSUM_SET(iphdr, 0);
#if CHECKSUM_GEN_IP
    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
#endif
  } else {
    /* IP header already included in p */
    iphdr = p->payload;
    dest = &(iphdr->dest);
  }

#if IP_FRAG
  /* don't fragment if interface has mtu set to 0 [loopif] */
  if (netif->mtu && (p->tot_len > netif->mtu))
    return ip_frag(p,netif,dest);
#endif

  IP_STATS_INC(ip.xmit);

  LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
  ip_debug_print(p);

  LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
  //acoral_print("\r\nIpOutPutIf***netif\r\n");
  return netif->output(netif, p, dest);
}

/**
 * Simple interface to ip_output_if. It finds the outgoing network
 * interface and calls upon ip_output_if to do the actual work.
 *
 * @param p the packet to send (p->payload points to the data, e.g. next
            protocol header; if dest == IP_HDRINCL, p already includes an IP
            header and p->payload points to that IP header)
 * @param src the source IP address to send from (if src == IP_ADDR_ANY, the
 *         IP  address of the netif used to send is used as source address)
 * @param dest the destination IP address to send the packet to
 * @param ttl the TTL value to be set in the IP header
 * @param tos the TOS value to be set in the IP header
 * @param proto the PROTOCOL to be set in the IP header
 *
 * @return ERR_RTE if no route is found
 *         see ip_output_if() for more return values
 */
err_t
ip_output(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
          u8_t ttl, u8_t tos, u8_t proto)
{
  struct netif *netif;

  if ((netif = ip_route(dest)) == NULL) {
    return ERR_RTE;
  }
  //acoral_print("\r\nIP_OUTPUT\r\n");
  return ip_output_if(p, src, dest, ttl, tos, proto, netif);
}

#if IP_DEBUG
/* Print an IP header by using LWIP_DEBUGF
 * @param p an IP packet, p->payload pointing to the IP header
 */
void
ip_debug_print(struct pbuf *p)
{
  struct ip_hdr *iphdr = p->payload;
  u8_t *payload;

  payload = (u8_t *)iphdr + IP_HLEN;

  LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
  LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
  LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" |%2"S16_F" |  0x%02"X16_F" |     %5"U16_F"     | (v, hl, tos, len)\n",
                    IPH_V(iphdr),
                    IPH_HL(iphdr),
                    IPH_TOS(iphdr),
                    ntohs(IPH_LEN(iphdr))));
  LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
  LWIP_DEBUGF(IP_DEBUG, ("|    %5"U16_F"      |%"U16_F"%"U16_F"%"U16_F"|    %4"U16_F"   | (id, flags, offset)\n",
                    ntohs(IPH_ID(iphdr)),
                    ntohs(IPH_OFFSET(iphdr)) >> 15 & 1,
                    ntohs(IPH_OFFSET(iphdr)) >> 14 & 1,
                    ntohs(IPH_OFFSET(iphdr)) >> 13 & 1,
                    ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK));
  LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
  LWIP_DEBUGF(IP_DEBUG, ("|  %3"U16_F"  |  %3"U16_F"  |    0x%04"X16_F"     | (ttl, proto, chksum)\n",
                    IPH_TTL(iphdr),
                    IPH_PROTO(iphdr),
                    ntohs(IPH_CHKSUM(iphdr))));
  LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
  LWIP_DEBUGF(IP_DEBUG, ("|  %3"U16_F"  |  %3"U16_F"  |  %3"U16_F"  |  %3"U16_F"  | (src)\n",
                    ip4_addr1(&iphdr->src),
                    ip4_addr2(&iphdr->src),
                    ip4_addr3(&iphdr->src),
                    ip4_addr4(&iphdr->src)));
  LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
  LWIP_DEBUGF(IP_DEBUG, ("|  %3"U16_F"  |  %3"U16_F"  |  %3"U16_F"  |  %3"U16_F"  | (dest)\n",
                    ip4_addr1(&iphdr->dest),
                    ip4_addr2(&iphdr->dest),
                    ip4_addr3(&iphdr->dest),
                    ip4_addr4(&iphdr->dest)));
  LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
}
Example #13
0
/* 调用途径:ethernetif_input() -> ethernet_input() -> ip_input() -> icmp_input()*/
void
icmp_input(struct pbuf *p, struct netif *inp)
{
  u8_t type;
#ifdef LWIP_DEBUG
  u8_t code;
#endif /* LWIP_DEBUG */
  struct icmp_echo_hdr *iecho;
  struct ip_hdr *iphdr;
	/* IP 地址 */
  struct ip_addr tmpaddr;
  s16_t hlen;

  ICMP_STATS_INC(icmp.recv);
  snmp_inc_icmpinmsgs();


	/* 指向IP首部 */
  iphdr = p->payload;
	/* 获得IP报头长度 */
  hlen = IPH_HL(iphdr) * 4;
	/* pbuf的payload向后移动到IP载荷,即ICMP报头处
	 * 如果IP的载荷小于4字节,则跳到lenerr处,释放pbuf
	 */
  if (pbuf_header(p, -hlen) || (p->tot_len < sizeof(u16_t)*2)) {
    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%"U16_F" bytes) received\n", p->tot_len));
    goto lenerr;
  }

	/* 获取ICMP报头中的类型 */
  type = *((u8_t *)p->payload);
#ifdef LWIP_DEBUG
  code = *(((u8_t *)p->payload)+1);
#endif /* LWIP_DEBUG */
  switch (type) {
	/* 如果ICMP类型是回显请求 */
  case ICMP_ECHO:
		/* 先检查目的IP地址是否合法 */
#if !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING
    {
			/* accepted表示是否对ICMP回显请求进行回应 */
      int accepted = 1;
#if !LWIP_MULTICAST_PING
      /* multicast destination address? */
			/* 如果目的IP地址是多播地址,则不回应 */
      if (ip_addr_ismulticast(&iphdr->dest)) {
        accepted = 0;
      }
#endif /* LWIP_MULTICAST_PING */
#if !LWIP_BROADCAST_PING
      /* broadcast destination address? */
			/* 如果目的IP地址是广播地址,则不回应 */
      if (ip_addr_isbroadcast(&iphdr->dest, inp)) {
        accepted = 0;
      }
#endif /* LWIP_BROADCAST_PING */
      /* broadcast or multicast destination address not acceptd? */
			/* 如果不回应,则释放pbuf后,返回 */
      if (!accepted) {
        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast or broadcast pings\n"));
        ICMP_STATS_INC(icmp.err);
        pbuf_free(p);
        return;
      }
    }
#endif /* !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING */
    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
		/* 检查ICMP报文长度是否合法,ICMP报文总长度不能小于ICMP报头长度8字节 */
    if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
			/* 跳到lenerr处执行返回操作 */
      goto lenerr;
    }
		/* 计算ICMP的校验和是否正确 */
    if (inet_chksum_pbuf(p) != 0) {
      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
			/* ICMP校验和错误,则释放pbuf,并返回 */
      pbuf_free(p);
      ICMP_STATS_INC(icmp.chkerr);
      snmp_inc_icmpinerrors();
      return;
    }
#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
    if (pbuf_header(p, (PBUF_IP_HLEN + PBUF_LINK_HLEN))) {
      /* p is not big enough to contain link headers
       * allocate a new one and copy p into it
       */
      struct pbuf *r;
      /* switch p->payload to ip header */
      if (pbuf_header(p, hlen)) {
        LWIP_ASSERT("icmp_input: moving p->payload to ip header failed\n", 0);
        goto memerr;
      }
      /* allocate new packet buffer with space for link headers */
      r = pbuf_alloc(PBUF_LINK, p->tot_len, PBUF_RAM);
      if (r == NULL) {
        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n"));
        goto memerr;
      }
      LWIP_ASSERT("check that first pbuf can hold struct the ICMP header",
                  (r->len >= hlen + sizeof(struct icmp_echo_hdr)));
      /* copy the whole packet including ip header */
      if (pbuf_copy(r, p) != ERR_OK) {
        LWIP_ASSERT("icmp_input: copying to new pbuf failed\n", 0);
        goto memerr;
      }
      iphdr = r->payload;
      /* switch r->payload back to icmp header */
      if (pbuf_header(r, -hlen)) {
        LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
        goto memerr;
      }
      /* free the original p */
      pbuf_free(p);
      /* we now have an identical copy of p that has room for link headers */
      p = r;
    } else {
      /* restore p->payload to point to icmp header */
      if (pbuf_header(p, -(s16_t)(PBUF_IP_HLEN + PBUF_LINK_HLEN))) {
        LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
        goto memerr;
      }
    }
#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
    /* At this point, all checks are OK. */
    /* We generate an answer by switching the dest and src ip addresses,
     * setting the icmp type to ECHO_RESPONSE and updating the checksum. */
		/* 校验完成,调整ICMP回显请求的相关字段,生成回显应答 
		 * 交换IP数据报的源IP和目的IP地址,填写ICMP报文的类型字段,并重新计算ICMP的校验和
		 */
		/* 获取ICMP报头指针 */
    iecho = p->payload;
		/* 交换IP报头的源IP地址和目的IP地址 */
    tmpaddr.addr = iphdr->src.addr;
    iphdr->src.addr = iphdr->dest.addr;
    iphdr->dest.addr = tmpaddr.addr;
		/* 设置ICMP报文类型为回显应答 */
    ICMPH_TYPE_SET(iecho, ICMP_ER);
    /* adjust the checksum */
		/* 调整ICMP的校验和 */
    if (iecho->chksum >= htons(0xffff - (ICMP_ECHO << 8))) {
      iecho->chksum += htons(ICMP_ECHO << 8) + 1;
    } else {
      iecho->chksum += htons(ICMP_ECHO << 8);
    }

    /* Set the correct TTL and recalculate the header checksum. */
		/* 设置IP首部的TTL */
    IPH_TTL_SET(iphdr, ICMP_TTL);
		/* 计算IP首部校验和 */
    IPH_CHKSUM_SET(iphdr, 0);
#if CHECKSUM_GEN_IP
    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
#endif /* CHECKSUM_GEN_IP */
		/* 注意:这里没有修改IP首部的标识字段,所以ICMP回显应答的IP首部的标识字段和
		 * ICMP回显请求的标识字段是相同的。理论上来说ICMP回显应答的IP首部标识字段应该
		 * 被修改,但为什么不修改?
		 * 对Linux主机进行ping,Linux主机回复的ICMP回显应答的IP首部的标识字段就修改了
		 */

    ICMP_STATS_INC(icmp.xmit);
    /* increase number of messages attempted to send */
    snmp_inc_icmpoutmsgs();
    /* increase number of echo replies attempted to send */
    snmp_inc_icmpoutechoreps();

		/* pbuf的payload由ICMP的报头移动到IP的报头,hlen保存了IP报头的长度 */
    if(pbuf_header(p, hlen)) {
      LWIP_ASSERT("Can't move over header in packet", 0);
			/* 移动失败 */
    } else {
			/* 移动成功 */
      err_t ret;
			/* 调用ip_output_if发送IP数据报,IP_HDRINCL表示IP首部已经填写好,并且
			 * pbuf的payload指向IP数据报首部,而不是IP载荷首部
			 */
      ret = ip_output_if(p, &(iphdr->src), IP_HDRINCL,
                   ICMP_TTL, 0, IP_PROTO_ICMP, inp);
      if (ret != ERR_OK) {
        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %c.\n", ret));
      }
    }
    break;
		
	/* 如果ICMP类型不是ICMP回显请求,则直接忽略 */
  default:
    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %"S16_F" code %"S16_F" not supported.\n", 
                (s16_t)type, (s16_t)code));
		/* 更新统计量 */
    ICMP_STATS_INC(icmp.proterr);
    ICMP_STATS_INC(icmp.drop);
  }
	/* 释放pbuf */
  pbuf_free(p);
  return;
lenerr:
  pbuf_free(p);
  ICMP_STATS_INC(icmp.lenerr);
  snmp_inc_icmpinerrors();
  return;
#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
memerr:
  pbuf_free(p);
  ICMP_STATS_INC(icmp.err);
  snmp_inc_icmpinerrors();
  return;
#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
}
Example #14
0
/**
 * Fragment an IP datagram if too large for the netif.
 *
 * Chop the datagram in MTU sized chunks and send them in order
 * by using a fixed size static memory buffer (PBUF_REF) or
 * point PBUF_REFs into p (depending on IP_FRAG_USES_STATIC_BUF).
 *
 * @param p ip packet to send
 * @param netif the netif on which to send
 * @param dest destination ip address to which to send
 *
 * @return ERR_OK if sent successfully, err_t otherwise
 */
err_t 
ip_frag(struct pbuf *p, struct netif *netif, ip_addr_t *dest)
{
  struct pbuf *rambuf;
#if IP_FRAG_USES_STATIC_BUF
  struct pbuf *header;
#else
#if !LWIP_NETIF_TX_SINGLE_PBUF
  struct pbuf *newpbuf;
#endif
  struct ip_hdr *original_iphdr;
#endif
  struct ip_hdr *iphdr;
  u16_t nfb;
  u16_t left, cop;
  u16_t mtu = netif->mtu;
  u16_t ofo, omf;
  u16_t last;
  u16_t poff = IP_HLEN;
  u16_t tmp;
#if !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF
  u16_t newpbuflen = 0;
  u16_t left_to_copy;
#endif

  /* Get a RAM based MTU sized pbuf */
#if IP_FRAG_USES_STATIC_BUF
  /* When using a static buffer, we use a PBUF_REF, which we will
   * use to reference the packet (without link header).
   * Layer and length is irrelevant.
   */
  rambuf = pbuf_alloc(PBUF_LINK, 0, PBUF_REF);
  if (rambuf == NULL) {
    LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc(PBUF_LINK, 0, PBUF_REF) failed\n"));
    return ERR_MEM;
  }
  rambuf->tot_len = rambuf->len = mtu;
  rambuf->payload = LWIP_MEM_ALIGN((void *)buf);

  /* Copy the IP header in it */
  iphdr = (struct ip_hdr *)rambuf->payload;
  SMEMCPY(iphdr, p->payload, IP_HLEN);
#else /* IP_FRAG_USES_STATIC_BUF */
  original_iphdr = (struct ip_hdr *)p->payload;
  iphdr = original_iphdr;
#endif /* IP_FRAG_USES_STATIC_BUF */

  /* Save original offset */
  tmp = ntohs(IPH_OFFSET(iphdr));
  ofo = tmp & IP_OFFMASK;
  omf = tmp & IP_MF;

  left = p->tot_len - IP_HLEN;

  nfb = (mtu - IP_HLEN) / 8;

  while (left) {
    last = (left <= mtu - IP_HLEN);

    /* Set new offset and MF flag */
    tmp = omf | (IP_OFFMASK & (ofo));
    if (!last) {
      tmp = tmp | IP_MF;
    }

    /* Fill this fragment */
    cop = last ? left : nfb * 8;

#if IP_FRAG_USES_STATIC_BUF
    poff += pbuf_copy_partial(p, (u8_t*)iphdr + IP_HLEN, cop, poff);
#else /* IP_FRAG_USES_STATIC_BUF */
#if LWIP_NETIF_TX_SINGLE_PBUF
    rambuf = pbuf_alloc(PBUF_IP, cop, PBUF_RAM);
    if (rambuf == NULL) {
      return ERR_MEM;
    }
    LWIP_ASSERT("this needs a pbuf in one piece!",
      (rambuf->len == rambuf->tot_len) && (rambuf->next == NULL));
    poff += pbuf_copy_partial(p, rambuf->payload, cop, poff);
    /* make room for the IP header */
    if(pbuf_header(rambuf, IP_HLEN)) {
      pbuf_free(rambuf);
      return ERR_MEM;
    }
    /* fill in the IP header */
    SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
    iphdr = rambuf->payload;
#else /* LWIP_NETIF_TX_SINGLE_PBUF */
    /* When not using a static buffer, create a chain of pbufs.
     * The first will be a PBUF_RAM holding the link and IP header.
     * The rest will be PBUF_REFs mirroring the pbuf chain to be fragged,
     * but limited to the size of an mtu.
     */
    rambuf = pbuf_alloc(PBUF_LINK, IP_HLEN, PBUF_RAM);
    if (rambuf == NULL) {
      return ERR_MEM;
    }
    LWIP_ASSERT("this needs a pbuf in one piece!",
                (p->len >= (IP_HLEN)));
    SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
    iphdr = (struct ip_hdr *)rambuf->payload;

    /* Can just adjust p directly for needed offset. */
    p->payload = (u8_t *)p->payload + poff;
    p->len -= poff;

    left_to_copy = cop;
    while (left_to_copy) {
      struct pbuf_custom_ref *pcr;
      newpbuflen = (left_to_copy < p->len) ? left_to_copy : p->len;
      /* Is this pbuf already empty? */
      if (!newpbuflen) {
        p = p->next;
        continue;
      }
      pcr = ip_frag_alloc_pbuf_custom_ref();
      if (pcr == NULL) {
        pbuf_free(rambuf);
        return ERR_MEM;
      }
      /* Mirror this pbuf, although we might not need all of it. */
      newpbuf = pbuf_alloced_custom(PBUF_RAW, newpbuflen, PBUF_REF, &pcr->pc, p->payload, newpbuflen);
      if (newpbuf == NULL) {
        ip_frag_free_pbuf_custom_ref(pcr);
        pbuf_free(rambuf);
        return ERR_MEM;
      }
      pbuf_ref(p);
      pcr->original = p;
      pcr->pc.custom_free_function = ipfrag_free_pbuf_custom;

      /* Add it to end of rambuf's chain, but using pbuf_cat, not pbuf_chain
       * so that it is removed when pbuf_dechain is later called on rambuf.
       */
      pbuf_cat(rambuf, newpbuf);
      left_to_copy -= newpbuflen;
      if (left_to_copy) {
        p = p->next;
      }
    }
    poff = newpbuflen;
#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
#endif /* IP_FRAG_USES_STATIC_BUF */

    /* Correct header */
    IPH_OFFSET_SET(iphdr, htons(tmp));
    IPH_LEN_SET(iphdr, htons(cop + IP_HLEN));
    IPH_CHKSUM_SET(iphdr, 0);
    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));

#if IP_FRAG_USES_STATIC_BUF
    if (last) {
      pbuf_realloc(rambuf, left + IP_HLEN);
    }

    /* This part is ugly: we alloc a RAM based pbuf for 
     * the link level header for each chunk and then 
     * free it.A PBUF_ROM style pbuf for which pbuf_header
     * worked would make things simpler.
     */
    header = pbuf_alloc(PBUF_LINK, 0, PBUF_RAM);
    if (header != NULL) {
      pbuf_chain(header, rambuf);
      netif->output(netif, header, dest);
      IPFRAG_STATS_INC(ip_frag.xmit);
      snmp_inc_ipfragcreates();
      pbuf_free(header);
    } else {
      LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc() for header failed\n"));
      pbuf_free(rambuf);
      return ERR_MEM;
    }
#else /* IP_FRAG_USES_STATIC_BUF */
    /* No need for separate header pbuf - we allowed room for it in rambuf
     * when allocated.
     */
    netif->output(netif, rambuf, dest);
    IPFRAG_STATS_INC(ip_frag.xmit);

    /* Unfortunately we can't reuse rambuf - the hardware may still be
     * using the buffer. Instead we free it (and the ensuing chain) and
     * recreate it next time round the loop. If we're lucky the hardware
     * will have already sent the packet, the free will really free, and
     * there will be zero memory penalty.
     */
    
    pbuf_free(rambuf);
#endif /* IP_FRAG_USES_STATIC_BUF */
    left -= cop;
    ofo += nfb;
  }
#if IP_FRAG_USES_STATIC_BUF
  pbuf_free(rambuf);
#endif /* IP_FRAG_USES_STATIC_BUF */
  snmp_inc_ipfragoks();
  return ERR_OK;
}
Example #15
0
/**
 * Processes ICMP input packets, called from ip_input().
 *
 * Currently only processes icmp echo requests and sends
 * out the echo response.
 *
 * @param p the icmp echo request packet, p->payload pointing to the ip header
 * @param inp the netif on which this packet was received
 */
void
icmp_input(struct pbuf *p, struct netif *inp)
{
  u8_t type;
#ifdef LWIP_DEBUG
  u8_t code;
#endif /* LWIP_DEBUG */
  struct icmp_echo_hdr *iecho;
  struct ip_hdr *iphdr;
  struct ip_addr tmpaddr;
  s16_t hlen;

  ICMP_STATS_INC(icmp.recv);
  snmp_inc_icmpinmsgs();


  iphdr = p->payload;
  hlen = IPH_HL(iphdr) * 4;
  if (pbuf_header(p, -hlen) || (p->tot_len < sizeof(u16_t)*2)) {
    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%"U16_F" bytes) received\n", p->tot_len));
    goto lenerr;
  }

  type = *((u8_t *)p->payload);
#ifdef LWIP_DEBUG
  code = *(((u8_t *)p->payload)+1);
#endif /* LWIP_DEBUG */
  switch (type) {
  case ICMP_ECHO:
    /* broadcast or multicast destination address? */
    if (ip_addr_isbroadcast(&iphdr->dest, inp) || ip_addr_ismulticast(&iphdr->dest)) {
      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast or broadcast pings\n"));
      ICMP_STATS_INC(icmp.err);
      pbuf_free(p);
      return;
    }
    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
    if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
      goto lenerr;
    }
    if (inet_chksum_pbuf(p) != 0) {
      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
      pbuf_free(p);
      ICMP_STATS_INC(icmp.chkerr);
      snmp_inc_icmpinerrors();
      return;
    }
    if (pbuf_header(p, (PBUF_IP_HLEN + PBUF_LINK_HLEN))) {
      /* p is not big enough to contain link headers
       * allocate a new one and copy p into it
       */
      struct pbuf *r;
      /* switch p->payload to ip header */
      if (pbuf_header(p, hlen)) {
        LWIP_ASSERT("icmp_input: moving p->payload to ip header failed\n", 0);
        goto memerr;
      }
      /* allocate new packet buffer with space for link headers */
      r = pbuf_alloc(PBUF_LINK, p->tot_len, PBUF_RAM);
      if (r == NULL) {
        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n"));
        goto memerr;
      }
      LWIP_ASSERT("check that first pbuf can hold struct the ICMP header",
                  (r->len >= hlen + sizeof(struct icmp_echo_hdr)));
      /* copy the whole packet including ip header */
      if (pbuf_copy(r, p) != ERR_OK) {
        LWIP_ASSERT("icmp_input: copying to new pbuf failed\n", 0);
        goto memerr;
      }
      iphdr = r->payload;
      /* switch r->payload back to icmp header */
      if (pbuf_header(r, -hlen)) {
        LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
        goto memerr;
      }
      /* free the original p */
      pbuf_free(p);
      /* we now have an identical copy of p that has room for link headers */
      p = r;
    } else {
      /* restore p->payload to point to icmp header */
      if (pbuf_header(p, -(s16_t)(PBUF_IP_HLEN + PBUF_LINK_HLEN))) {
        LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
        goto memerr;
      }
    }
    /* At this point, all checks are OK. */
    /* We generate an answer by switching the dest and src ip addresses,
     * setting the icmp type to ECHO_RESPONSE and updating the checksum. */
    iecho = p->payload;
    tmpaddr.addr = iphdr->src.addr;
    iphdr->src.addr = iphdr->dest.addr;
    iphdr->dest.addr = tmpaddr.addr;
    ICMPH_TYPE_SET(iecho, ICMP_ER);
    /* adjust the checksum */
    if (iecho->chksum >= htons(0xffff - (ICMP_ECHO << 8))) {
      iecho->chksum += htons(ICMP_ECHO << 8) + 1;
    } else {
      iecho->chksum += htons(ICMP_ECHO << 8);
    }

    /* Set the correct TTL and recalculate the header checksum. */
    IPH_TTL_SET(iphdr, ICMP_TTL);
    IPH_CHKSUM_SET(iphdr, 0);
#if CHECKSUM_GEN_IP
    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
#endif /* CHECKSUM_GEN_IP */

    ICMP_STATS_INC(icmp.xmit);
    /* increase number of messages attempted to send */
    snmp_inc_icmpoutmsgs();
    /* increase number of echo replies attempted to send */
    snmp_inc_icmpoutechoreps();

    if(pbuf_header(p, hlen)) {
      LWIP_ASSERT("Can't move over header in packet", 0);
    } else {
      err_t ret;
      ret = ip_output_if(p, &(iphdr->src), IP_HDRINCL,
                   ICMP_TTL, 0, IP_PROTO_ICMP, inp);
      if (ret != ERR_OK) {
        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %c.\n", ret));
      }
    }
    break;
  default:
    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %"S16_F" code %"S16_F" not supported.\n", 
                (s16_t)type, (s16_t)code));
    ICMP_STATS_INC(icmp.proterr);
    ICMP_STATS_INC(icmp.drop);
  }
  pbuf_free(p);
  return;
lenerr:
  pbuf_free(p);
  ICMP_STATS_INC(icmp.lenerr);
  snmp_inc_icmpinerrors();
  return;
memerr:
  pbuf_free(p);
  ICMP_STATS_INC(icmp.err);
  snmp_inc_icmpinerrors();
  return;
}
Example #16
0
/* Ping using the raw ip */
static u8_t ICACHE_FLASH_ATTR
ping_recv(void *arg, struct raw_pcb *pcb, struct pbuf *p, ip_addr_t *addr)
{
  struct icmp_echo_hdr *iecho = NULL;
  static u16_t seqno = 0;
  struct ping_msg *pingmsg = (struct ping_msg*)arg;

  LWIP_UNUSED_ARG(arg);
  LWIP_UNUSED_ARG(pcb);
  LWIP_UNUSED_ARG(addr);
  LWIP_ASSERT("p != NULL", p != NULL);

  if (pbuf_header( p, -PBUF_IP_HLEN)==0) {
    iecho = (struct icmp_echo_hdr *)p->payload;

    if ((iecho->id == PING_ID) && (iecho->seqno == htons(ping_seq_num)) && iecho->type == ICMP_ER) {
      LWIP_DEBUGF( PING_DEBUG, ("ping: recv "));
      ip_addr_debug_print(PING_DEBUG, addr);
      LWIP_DEBUGF( PING_DEBUG, (" %"U32_F" ms\n", (sys_now()-ping_time)));
	  if (iecho->seqno != seqno){
		  /* do some ping result processing */
		  {
			  struct ip_hdr *iphdr = NULL;
			  char ipaddrstr[16];
			  ip_addr_t source_ip;
			  sys_untimeout(ping_timeout, pingmsg);
			  os_bzero(&source_ip, sizeof(ip_addr_t));
			  os_bzero(ipaddrstr, sizeof(ipaddrstr));
			  uint32 delay = system_relative_time(pingmsg->ping_sent);
			  delay /= PING_COARSE;
			  iphdr = (struct ip_hdr*)((u8*)iecho - PBUF_IP_HLEN);
			  source_ip.addr = iphdr->src.addr;
			  ipaddr_ntoa_r(&source_ip,ipaddrstr, sizeof(ipaddrstr));
			  if (pingmsg->ping_opt->recv_function == NULL){
				  os_printf("recv %s: byte = %d, time = %d ms, seq = %d\n",ipaddrstr, PING_DATA_SIZE, delay, ntohs(iecho->seqno));
			  } else {
				  struct ping_resp pingresp;
				  os_bzero(&pingresp, sizeof(struct ping_resp));
				  pingresp.bytes = PING_DATA_SIZE;
				  pingresp.resp_time = delay;
				  pingresp.seqno = ntohs(iecho->seqno);
				  pingresp.ping_err = 0;
				  pingmsg->ping_opt->recv_function(pingmsg->ping_opt,(void*) &pingresp);
			  }
		  }
		  seqno = iecho->seqno;
	  }

      PING_RESULT(1);
      pbuf_free(p);
      return 1; /* eat the packet */
    }
//    } else if(iecho->type == ICMP_ECHO){
//        struct pbuf *q = NULL;
//        os_printf("receive ping request:seq=%d\n", ntohs(iecho->seqno));
//        q = pbuf_alloc(PBUF_IP, (u16_t)p->tot_len, PBUF_RAM);
//        if (q!=NULL) {
//            pbuf_copy(q, p);
//            iecho = (struct icmp_echo_hdr *)q->payload;
//            ping_prepare_er(iecho, q->tot_len);
//            raw_sendto(pcb, q, addr);
//            pbuf_free(q);
//        }
//        pbuf_free(p);
//        return 1;
//    }
  }

  return 0; /* don't eat the packet */
}
Example #17
0
/**
 * Processes ICMP input packets, called from ip_input().
 *
 * Currently only processes icmp echo requests and sends
 * out the echo response.
 *
 * @param p the icmp echo request packet, p->payload pointing to the icmp header
 * @param inp the netif on which this packet was received
 */
void
icmp_input(struct pbuf *p, struct netif *inp)
{
  u8_t type;
#ifdef LWIP_DEBUG
  u8_t code;
#endif /* LWIP_DEBUG */
  struct icmp_echo_hdr *iecho;
  struct ip_hdr *iphdr;
  s16_t hlen;

  ICMP_STATS_INC(icmp.recv);
  snmp_inc_icmpinmsgs();

  iphdr = (struct ip_hdr *)ip_current_header();
  hlen = IPH_HL(iphdr) * 4;
  if (p->len < sizeof(u16_t)*2) {
    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%"U16_F" bytes) received\n", p->tot_len));
    goto lenerr;
  }

  type = *((u8_t *)p->payload);
#ifdef LWIP_DEBUG
  code = *(((u8_t *)p->payload)+1);
#endif /* LWIP_DEBUG */
  switch (type) {
  case ICMP_ER:
    /* This is OK, echo reply might have been parsed by a raw PCB
       (as obviously, an echo request has been sent, too). */
    break; 
  case ICMP_ECHO:
#if !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING
    {
      int accepted = 1;
#if !LWIP_MULTICAST_PING
      /* multicast destination address? */
      if (ip_addr_ismulticast(ip_current_dest_addr())) {
        accepted = 0;
      }
#endif /* LWIP_MULTICAST_PING */
#if !LWIP_BROADCAST_PING
      /* broadcast destination address? */
      if (ip_addr_isbroadcast(ip_current_dest_addr(), inp)) {
        accepted = 0;
      }
#endif /* LWIP_BROADCAST_PING */
      /* broadcast or multicast destination address not accepted? */
      if (!accepted) {
        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast or broadcast pings\n"));
        ICMP_STATS_INC(icmp.err);
        pbuf_free(p);
        return;
      }
    }
#endif /* !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING */
    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
    if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
      goto lenerr;
    }
#if CHECKSUM_CHECK_ICMP
    if (inet_chksum_pbuf(p) != 0) {
      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
      pbuf_free(p);
      ICMP_STATS_INC(icmp.chkerr);
      snmp_inc_icmpinerrors();
      return;
    }
#endif
#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
    if (pbuf_header(p, (PBUF_IP_HLEN + PBUF_LINK_HLEN))) {
      /* p is not big enough to contain link headers
       * allocate a new one and copy p into it
       */
      struct pbuf *r;
      /* allocate new packet buffer with space for link headers */
      r = pbuf_alloc(PBUF_LINK, p->tot_len + hlen, PBUF_RAM);
      if (r == NULL) {
        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n"));
        goto memerr;
      }
      LWIP_ASSERT("check that first pbuf can hold struct the ICMP header",
                  (r->len >= hlen + sizeof(struct icmp_echo_hdr)));
      /* copy the ip header */
      MEMCPY(r->payload, iphdr, hlen);
      iphdr = (struct ip_hdr *)r->payload;
      /* switch r->payload back to icmp header */
      if (pbuf_header(r, -hlen)) {
        LWIP_ASSERT("icmp_input: moving r->payload to icmp header failed\n", 0);
        goto memerr;
      }
      /* copy the rest of the packet without ip header */
      if (pbuf_copy(r, p) != ERR_OK) {
        LWIP_ASSERT("icmp_input: copying to new pbuf failed\n", 0);
        goto memerr;
      }
      /* free the original p */
      pbuf_free(p);
      /* we now have an identical copy of p that has room for link headers */
      p = r;
    } else {
      /* restore p->payload to point to icmp header */
      if (pbuf_header(p, -(s16_t)(PBUF_IP_HLEN + PBUF_LINK_HLEN))) {
        LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
        goto memerr;
      }
    }
#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
    /* At this point, all checks are OK. */
    /* We generate an answer by switching the dest and src ip addresses,
     * setting the icmp type to ECHO_RESPONSE and updating the checksum. */
    iecho = (struct icmp_echo_hdr *)p->payload;
    ip_addr_copy(iphdr->src, inp->ip_addr);
    ip_addr_copy(iphdr->dest, *ip_current_src_addr());
    ICMPH_TYPE_SET(iecho, ICMP_ER);
#if CHECKSUM_GEN_ICMP
    /* adjust the checksum */
    if (iecho->chksum >= PP_HTONS(0xffffU - (ICMP_ECHO << 8))) {
      iecho->chksum += PP_HTONS(ICMP_ECHO << 8) + 1;
    } else {
      iecho->chksum += PP_HTONS(ICMP_ECHO << 8);
    }
#else /* CHECKSUM_GEN_ICMP */
    iecho->chksum = 0;
#endif /* CHECKSUM_GEN_ICMP */

    /* Set the correct TTL and recalculate the header checksum. */
    IPH_TTL_SET(iphdr, ICMP_TTL);
    IPH_CHKSUM_SET(iphdr, 0);
#if CHECKSUM_GEN_IP
    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
#endif /* CHECKSUM_GEN_IP */

    ICMP_STATS_INC(icmp.xmit);
    /* increase number of messages attempted to send */
    snmp_inc_icmpoutmsgs();
    /* increase number of echo replies attempted to send */
    snmp_inc_icmpoutechoreps();

    if(pbuf_header(p, hlen)) {
      LWIP_ASSERT("Can't move over header in packet", 0);
    } else {
      err_t ret;
      /* send an ICMP packet, src addr is the dest addr of the current packet */
      ret = ip_output_if(p, ip_current_dest_addr(), IP_HDRINCL,
                   ICMP_TTL, 0, IP_PROTO_ICMP, inp);
      if (ret != ERR_OK) {
        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %c.\n", ret));
      }
    }
    break;
  default:
    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %"S16_F" code %"S16_F" not supported.\n", 
                (s16_t)type, (s16_t)code));
    ICMP_STATS_INC(icmp.proterr);
    ICMP_STATS_INC(icmp.drop);
  }
  pbuf_free(p);
  return;
lenerr:
  pbuf_free(p);
  ICMP_STATS_INC(icmp.lenerr);
  snmp_inc_icmpinerrors();
  return;
#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
memerr:
  pbuf_free(p);
  ICMP_STATS_INC(icmp.err);
  snmp_inc_icmpinerrors();
  return;
#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
}
Example #18
0
/**
 * Process an incoming UDP datagram.
 *
 * Given an incoming UDP datagram (as a chain of pbufs) this function
 * finds a corresponding UDP PCB and hands over the pbuf to the pcbs
 * recv function. If no pcb is found or the datagram is incorrect, the
 * pbuf is freed.
 *
 * @param p pbuf to be demultiplexed to a UDP PCB (p->payload pointing to the UDP header)
 * @param inp network interface on which the datagram was received.
 *
 */
void
udp_input(struct pbuf *p, struct netif *inp)
{
  struct udp_hdr *udphdr;
  struct udp_pcb *pcb, *prev;
  struct udp_pcb *uncon_pcb;
  u16_t src, dest;
  u8_t broadcast;
  u8_t for_us = 0;

  LWIP_UNUSED_ARG(inp);

  PERF_START;

  UDP_STATS_INC(udp.recv);

  /* Check minimum length (UDP header) */
  if (p->len < UDP_HLEN) {
    /* drop short packets */
    LWIP_DEBUGF(UDP_DEBUG,
                ("udp_input: short UDP datagram (%"U16_F" bytes) discarded\n", p->tot_len));
    UDP_STATS_INC(udp.lenerr);
    UDP_STATS_INC(udp.drop);
    MIB2_STATS_INC(mib2.udpinerrors);
    pbuf_free(p);
    goto end;
  }

  udphdr = (struct udp_hdr *)p->payload;

  /* is broadcast packet ? */
  broadcast = ip_addr_isbroadcast(ip_current_dest_addr(), ip_current_netif());

  LWIP_DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %"U16_F"\n", p->tot_len));

  /* convert src and dest ports to host byte order */
  src = ntohs(udphdr->src);
  dest = ntohs(udphdr->dest);

  udp_debug_print(udphdr);

  /* print the UDP source and destination */
  LWIP_DEBUGF(UDP_DEBUG, ("udp ("));
  ip_addr_debug_print(UDP_DEBUG, ip_current_dest_addr());
  LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", ntohs(udphdr->dest)));
  ip_addr_debug_print(UDP_DEBUG, ip_current_src_addr());
  LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F")\n", ntohs(udphdr->src)));

  pcb = NULL;
  prev = NULL;
  uncon_pcb = NULL;
  /* Iterate through the UDP pcb list for a matching pcb.
   * 'Perfect match' pcbs (connected to the remote port & ip address) are
   * preferred. If no perfect match is found, the first unconnected pcb that
   * matches the local port and ip address gets the datagram. */
  for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
    /* print the PCB local and remote address */
    LWIP_DEBUGF(UDP_DEBUG, ("pcb ("));
    ip_addr_debug_print(UDP_DEBUG, &pcb->local_ip);
    LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", pcb->local_port));
    ip_addr_debug_print(UDP_DEBUG, &pcb->remote_ip);
    LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F")\n", pcb->remote_port));

    /* compare PCB local addr+port to UDP destination addr+port */
    if ((pcb->local_port == dest) &&
        (udp_input_local_match(pcb, inp, broadcast) != 0)) {
      if (((pcb->flags & UDP_FLAGS_CONNECTED) == 0) &&
          ((uncon_pcb == NULL)
#if SO_REUSE
          /* prefer specific IPs over cath-all */
          || !ip_addr_isany(&pcb->local_ip)
#endif /* SO_REUSE */
          )) {
        /* the first unconnected matching PCB */
        uncon_pcb = pcb;
      }

      /* compare PCB remote addr+port to UDP source addr+port */
      if ((pcb->remote_port == src) &&
          (ip_addr_isany_val(pcb->remote_ip) ||
          ip_addr_cmp(&pcb->remote_ip, ip_current_src_addr()))) {
        /* the first fully matching PCB */
        if (prev != NULL) {
          /* move the pcb to the front of udp_pcbs so that is
             found faster next time */
          prev->next = pcb->next;
          pcb->next = udp_pcbs;
          udp_pcbs = pcb;
        } else {
          UDP_STATS_INC(udp.cachehit);
        }
        break;
      }
    }

    prev = pcb;
  }
  /* no fully matching pcb found? then look for an unconnected pcb */
  if (pcb == NULL) {
    pcb = uncon_pcb;
  }

  /* Check checksum if this is a match or if it was directed at us. */
  if (pcb != NULL) {
    for_us = 1;
  } else {
#if LWIP_IPV6
    if (ip_current_is_v6()) {
      for_us = netif_get_ip6_addr_match(inp, ip6_current_dest_addr()) >= 0;
    }
#endif /* LWIP_IPV6 */
#if LWIP_IPV4
    if (!ip_current_is_v6()) {
      for_us = ip4_addr_cmp(netif_ip4_addr(inp), ip4_current_dest_addr());
    }
#endif /* LWIP_IPV4 */
  }

  if (for_us) {
    LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: calculating checksum\n"));
#if CHECKSUM_CHECK_UDP
    IF__NETIF_CHECKSUM_ENABLED(inp, CHECKSUM_CHECK_UDP) {
#if LWIP_UDPLITE
      if (ip_current_header_proto() == IP_PROTO_UDPLITE) {
        /* Do the UDP Lite checksum */
        u16_t chklen = ntohs(udphdr->len);
        if (chklen < sizeof(struct udp_hdr)) {
          if (chklen == 0) {
            /* For UDP-Lite, checksum length of 0 means checksum
               over the complete packet (See RFC 3828 chap. 3.1) */
            chklen = p->tot_len;
          } else {
            /* At least the UDP-Lite header must be covered by the
               checksum! (Again, see RFC 3828 chap. 3.1) */
            goto chkerr;
          }
        }
        if (ip_chksum_pseudo_partial(p, IP_PROTO_UDPLITE,
                     p->tot_len, chklen,
                     ip_current_src_addr(), ip_current_dest_addr()) != 0) {
          goto chkerr;
        }
      } else
#endif /* LWIP_UDPLITE */
      {
        if (udphdr->chksum != 0) {
          if (ip_chksum_pseudo(p, IP_PROTO_UDP, p->tot_len,
                               ip_current_src_addr(),
                               ip_current_dest_addr()) != 0) {
            goto chkerr;
          }
        }
      }
    }
#endif /* CHECKSUM_CHECK_UDP */
    if (pbuf_header(p, -UDP_HLEN)) {
      /* Can we cope with this failing? Just assert for now */
      LWIP_ASSERT("pbuf_header failed\n", 0);
      UDP_STATS_INC(udp.drop);
      MIB2_STATS_INC(mib2.udpinerrors);
      pbuf_free(p);
      goto end;
    }

    if (pcb != NULL) {
      MIB2_STATS_INC(mib2.udpindatagrams);
#if SO_REUSE && SO_REUSE_RXTOALL
      if (ip_get_option(pcb, SOF_REUSEADDR) &&
          (broadcast || ip_addr_ismulticast(ip_current_dest_addr()))) {
        /* pass broadcast- or multicast packets to all multicast pcbs
           if SOF_REUSEADDR is set on the first match */
        struct udp_pcb *mpcb;
        u8_t p_header_changed = 0;
        s16_t hdrs_len = (s16_t)(ip_current_header_tot_len() + UDP_HLEN);
        for (mpcb = udp_pcbs; mpcb != NULL; mpcb = mpcb->next) {
          if (mpcb != pcb) {
            /* compare PCB local addr+port to UDP destination addr+port */
            if ((mpcb->local_port == dest) &&
                (udp_input_local_match(mpcb, inp, broadcast) != 0)) {
              /* pass a copy of the packet to all local matches */
              if (mpcb->recv != NULL) {
                struct pbuf *q;
                /* for that, move payload to IP header again */
                if (p_header_changed == 0) {
                  pbuf_header_force(p, hdrs_len);
                  p_header_changed = 1;
                }
                q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
                if (q != NULL) {
                  err_t err = pbuf_copy(q, p);
                  if (err == ERR_OK) {
                    /* move payload to UDP data */
                    pbuf_header(q, -hdrs_len);
                    mpcb->recv(mpcb->recv_arg, mpcb, q, ip_current_src_addr(), src);
                  }
                }
              }
            }
          }
        }
        if (p_header_changed) {
          /* and move payload to UDP data again */
          pbuf_header(p, -hdrs_len);
        }
      }
#endif /* SO_REUSE && SO_REUSE_RXTOALL */
      /* callback */
      if (pcb->recv != NULL) {
        /* now the recv function is responsible for freeing p */
        pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr(), src);
      } else {
        /* no recv function registered? then we have to free the pbuf! */
        pbuf_free(p);
        goto end;
      }
    } else {
      LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: not for us.\n"));

#if LWIP_ICMP || LWIP_ICMP6
      /* No match was found, send ICMP destination port unreachable unless
         destination address was broadcast/multicast. */
      if (!broadcast && !ip_addr_ismulticast(ip_current_dest_addr())) {
        /* move payload pointer back to ip header */
        pbuf_header_force(p, ip_current_header_tot_len() + UDP_HLEN);
        icmp_port_unreach(ip_current_is_v6(), p);
      }
#endif /* LWIP_ICMP || LWIP_ICMP6 */
      UDP_STATS_INC(udp.proterr);
      UDP_STATS_INC(udp.drop);
      MIB2_STATS_INC(mib2.udpnoports);
      pbuf_free(p);
    }
  } else {
Example #19
0
static int recv_common(int s, void * mem, int len, unsigned int flags, int istcp) {
	sockfd_t	* fd;
	int		rv = 0, amt, totalrcv;
	uint8		* buf;
	struct pbuf	* p;

	if (flags != 0) {
		errno = EINVAL;
		return -1;
	}

	if (len <= 0) {
		errno = EINVAL;
		return -1;
	}

	fd = fds + s;

	// printf("lwip_recv(%d): want %d bytes\n", s, len);

	// Get access
	mutex_lock(fd->mutex);

	// Is there data available now?
	while (fd->recv <= 0) {
		// Make sure we're capable of reading
		if (fd->recv < 0) {
			rv = 0; goto out;
		}

		// Wait for more data to be available
		//printf("cond_wait for more data\n");
		cond_wait(fd->recv_avail, fd->mutex);
		//printf("woken\n");
	}

	// Ok, some data should be available now
	assert( fd->recv_buf );
	if (!fd->recv_buf) {
		///
		rv = -1; goto out;
	}

	// Pull data out into the client buffer
	buf = (uint8 *)mem;
	totalrcv = 0;
	for (p = fd->recv_buf; p && len > 0; ) {
		// How much to pull from this pbuf?
		if (p->len > len)
			amt = len;
		else
			amt = p->len;

		//printf("  pbuf: %d avail, want %d\n", p->len, amt);

		// Do it.
		memcpy(buf, p->payload, amt);
		buf += amt;
		totalrcv += amt;
		len -= amt;

		// Did we take the whole thing?
		if (amt == p->len) {
			// Yes. Dechain it and move forwards.
			fd->recv_buf = p->next;
			if (fd->recv_buf)
				pbuf_ref(fd->recv_buf);
			pbuf_free(p);
			p = fd->recv_buf;
		} else {
			// Nope. Just adjust the "header".
			pbuf_header(p, -amt);
			p = NULL;
		}
	}

	// ACK the amount we actually read out
	//printf("lwip_read(%d): ACK'ing %d bytes\n", s, totalrcv);
	rv = totalrcv;
	if (istcp)
		tcp_recved(fd->tcppcb, rv);
	fd->recv -= rv;
	//printf("returning\n");

out:
	mutex_unlock(fd->mutex);	
	return rv;
}
Example #20
0
/*-----------------------------------------------------------------------------------*/
struct pbuf *
etharp_output(struct netif *netif, struct ip_addr *ipaddr, struct pbuf *q)
{
    struct eth_addr *dest, *srcaddr, mcastaddr;
    struct eth_hdr *ethhdr;
    struct etharp_hdr *hdr;
    struct pbuf *p;
    u8_t i;

    srcaddr = (struct eth_addr *)netif->hwaddr;

    /* Make room for Ethernet header. */
    if(pbuf_header(q, sizeof(struct eth_hdr)) != 0) {
        /* The pbuf_header() call shouldn't fail, and we'll just bail
           out if it does.. */
        DEBUGF(ETHARP_DEBUG, ("etharp_output: could not allocate room for header.\n"));
#ifdef LINK_STATS
        ++stats.link.lenerr;
#endif /* LINK_STATS */
        return NULL;
    }


    dest = NULL;
    /* Construct Ethernet header. Start with looking up deciding which
       MAC address to use as a destination address. Broadcasts and
       multicasts are special, all other addresses are looked up in the
       ARP table. */
    if(ip_addr_isany(ipaddr) ||
            ip_addr_isbroadcast(ipaddr, &(netif->netmask))) {
        dest = (struct eth_addr *)&ethbroadcast;
    } else if(ip_addr_ismulticast(ipaddr)) {
        /* Hash IP multicast address to MAC address. */
        mcastaddr.addr[0] = 0x01;
        mcastaddr.addr[1] = 0x0;
        mcastaddr.addr[2] = 0x5e;
        mcastaddr.addr[3] = ip4_addr2(ipaddr) & 0x7f;
        mcastaddr.addr[4] = ip4_addr3(ipaddr);
        mcastaddr.addr[5] = ip4_addr4(ipaddr);
        dest = &mcastaddr;
    } else {
#ifdef __PAULOS__
        /* abort on insane conditions */
        if (!ip_addr_maskcmp(ipaddr, &(netif->ip_addr), &(netif->netmask)))
            return NULL;
        if (ipaddr->addr == netif->ip_addr.addr)
            return NULL;
#else
        if(!ip_addr_maskcmp(ipaddr, &(netif->ip_addr), &(netif->netmask))) {
            /* Use the IP address of the default gateway if the destination
               is NOT on the same subnet as we are. ("NOT" added 20021113 [email protected]) */
            ipaddr = &(netif->gw);
        }
#endif

        /* We try to find a stable mapping. */
        for(i = 0; i < arp_table_last; ++i) {
            if((arp_table[i].state == ETHARP_STATE_STABLE || arp_table[i].state == ETHARP_STATE_STATIC) &&
                    ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) {
                dest = &arp_table[i].ethaddr;

#if 0
// FIXME: remove this test code
                if (!((int) rand() % 2)) {
                    dest = NULL;
                    arp_table[i].state = ETHARP_STATE_EMPTY;
                    if (arp_table[i].p)
                        pbuf_free (arp_table[i].p);
                    arp_table[i].p = NULL;
                    arp_table[i].payload = NULL;
                    arp_table[i].len = arp_table[0].tot_len = 0;
                }
#endif

                break;
            }
        }
    }

    if(dest == NULL) {
        /* No destination address has been found, so we'll have to send
           out an ARP request for the IP address. The outgoing packet is
           queued unless the queue is full. */

        /* We check if we are already querying for this address. If so,
           we'll bail out. */
        for(i = 0; i < arp_table_last; ++i) {
            if(arp_table[i].state == ETHARP_STATE_PENDING &&
                    ip_addr_cmp(ipaddr, &arp_table[i].ipaddr)) {
                DEBUGF(ETHARP_DEBUG, ("etharp_output: already queued\n"));
                return NULL;
            }
        }

        hdr = q->payload;
        for(i = 0; i < 6; ++i)
            hdr->ethhdr.src.addr[i] = srcaddr->addr[i];
        hdr->ethhdr.type = htons(ETHTYPE_IP);

        i = etharp_new_entry(q, ipaddr, NULL, ETHARP_STATE_PENDING);

        /* We allocate a pbuf for the outgoing ARP request packet. */
        p = pbuf_alloc(PBUF_RAW, sizeof(struct etharp_hdr) + 2, PBUF_RAM);
        if(p == NULL) {
            /* No ARP request packet could be allocated, so we forget about
            the ARP table entry. */
            if(i != ARP_TABLE_SIZE) {
                arp_table[i].state = ETHARP_STATE_EMPTY;
                /* We decrease the reference count of the queued pbuf (which now
                   is dequeued). */
                DEBUGF(ETHARP_DEBUG, ("etharp_output: couldn't alloc pbuf for query, dequeueing %p\n", q));
            }
            return NULL;
        }
        pbuf_header (p, (s16_t) -2);

        hdr = p->payload;

        hdr->opcode = htons(ARP_REQUEST);

        for(i = 0; i < 6; ++i) {
            hdr->dhwaddr.addr[i] = 0x00;
            hdr->shwaddr.addr[i] = srcaddr->addr[i];
        }

        memcpy (&(hdr->dipaddr), ipaddr, sizeof (hdr->dipaddr));
        memcpy (&(hdr->sipaddr), &(netif->ip_addr), sizeof (hdr->sipaddr));

        hdr->hwtype = htons(HWTYPE_ETHERNET);
        ARPH_HWLEN_SET(hdr, 6);

        hdr->proto = htons(ETHTYPE_IP);
        ARPH_PROTOLEN_SET(hdr, sizeof(struct ip_addr));

        for(i = 0; i < 6; ++i) {
            hdr->ethhdr.dest.addr[i] = 0xff;
            hdr->ethhdr.src.addr[i] = srcaddr->addr[i];
        }

        hdr->ethhdr.type = htons(ETHTYPE_ARP);
        return p;	/* (1) */
    } else {
        /* A valid IP->MAC address mapping was found, so we construct the
           Ethernet header for the outgoing packet. */

        ethhdr = q->payload;

        for(i = 0; i < 6; i++) {
            ethhdr->dest.addr[i] = dest->addr[i];
            ethhdr->src.addr[i] = srcaddr->addr[i];
        }

        ethhdr->type = htons(ETHTYPE_IP);

        pbuf_ref (q);  /* <--- this is important, because the reference
must parallel that when returning over here (1). Callers must then
ALWAYS do a pbuf_free on the return value of etharp_output(). */
        return q;
    }


}
Example #21
0
/**
 * Send the raw IP packet to the given address. Note that actually you cannot
 * modify the IP headers (this is inconsistent with the receive callback where
 * you actually get the IP headers), you can only specify the IP payload here.
 * It requires some more changes in lwIP. (there will be a raw_send() function
 * then.)
 *
 * @param pcb the raw pcb which to send
 * @param p the IP payload to send
 * @param ipaddr the destination address of the IP packet
 *
 */
err_t
raw_sendto(struct raw_pcb *pcb, struct pbuf *p, struct ip_addr *ipaddr)
{
  err_t err;
  struct netif *netif;
  struct ip_addr *src_ip;
  struct pbuf *q; /* q will be sent down the stack */
  
  LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | 3, ("raw_sendto\n"));
  
  /* not enough space to add an IP header to first pbuf in given p chain? */
  if (pbuf_header(p, IP_HLEN)) {
    /* allocate header in new pbuf */
    q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM);
    /* new header pbuf could not be allocated? */
    if (q == NULL) {
      LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | 2, ("raw_sendto: could not allocate header\n"));
      return ERR_MEM;
    }
    /* chain header q in front of given pbuf p */
    pbuf_chain(q, p);
    /* { first pbuf q points to header pbuf } */
    LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
  }  else {
    /* first pbuf q equals given pbuf */
    q = p;
    if(pbuf_header(q, -IP_HLEN)) {
      LWIP_ASSERT("Can't restore header we just removed!", 0);
      return ERR_MEM;
    }
  }
  
  if ((netif = ip_route(ipaddr)) == NULL) {
    LWIP_DEBUGF(RAW_DEBUG | 1, ("raw_sendto: No route to 0x%"X32_F"\n", ipaddr->addr));
    /* free any temporary header pbuf allocated by pbuf_header() */
    if (q != p) {
      pbuf_free(q);
    }
    return ERR_RTE;
  }

  if (ip_addr_isany(&pcb->local_ip)) {
    /* use outgoing network interface IP address as source address */
    src_ip = &(netif->ip_addr);
  } else {
    /* use RAW PCB local IP address as source address */
    src_ip = &(pcb->local_ip);
  }

#if LWIP_NETIF_HWADDRHINT
  netif->addr_hint = &(pcb->addr_hint);
#endif /* LWIP_NETIF_HWADDRHINT*/
  err = ip_output_if (q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif);
#if LWIP_NETIF_HWADDRHINT
  netif->addr_hint = NULL;
#endif /* LWIP_NETIF_HWADDRHINT*/

  /* did we chain a header earlier? */
  if (q != p) {
    /* free the header */
    pbuf_free(q);
  }
  return err;
}
/**
 * Should allocate a pbuf and transfer the bytes of the incoming
 * packet from the interface into the pbuf.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return a pbuf filled with the received packet (including MAC header)
 *         NULL on memory error
 */
static struct pbuf *
low_level_input(struct netif *netif, RX_PACKET_INFO_T *rx_packet)
{
//  struct ethernetif *ethernetif = netif->state;
  struct pbuf *p, *q;
  u16_t len;
  int index;
  unsigned char *rx_buf = rx_packet->data_ptr;


  /* Obtain the size of the packet and put it into the "len"
     variable. */
  len = rx_packet->data_len;
  if(len==0){
		//DEBUG_INFO("eth rx no data");
		return NULL;
  }

  if(len==(ETH_RX_BUF_SIZE-1)){
		DEBUG_ERROR("eth rx buf size not enough");
  }


#if ETH_PAD_SIZE
  len += ETH_PAD_SIZE; /* allow room for Ethernet padding */
#endif

  /* We allocate a pbuf chain of pbufs from the pool. */
  p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);

  if (p != NULL) {

#if ETH_PAD_SIZE
    pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
#endif
	index = 0;
    /* We iterate over the pbuf chain until we have read the entire
     * packet into the pbuf. */
    for(q = p; q != NULL; q = q->next) {
      /* Read enough bytes to fill this pbuf in the chain. The
       * available data in the pbuf is given by the q->len
       * variable.
       * This does not necessarily have to be a memcpy, you can also preallocate
       * pbufs for a DMA-enabled MAC and after receiving truncate it to the
       * actually received size. In this case, ensure the tot_len member of the
       * pbuf is the sum of the chained pbuf len members.
       */
      MEMCPY(q->payload, (rx_buf+index), q->len);
		index += q->len;
    }

    DEBUG_ASSERT(index == p->tot_len);

#if ETH_PAD_SIZE
    pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
#endif

    LINK_STATS_INC(link.recv);
  } else {
    LINK_STATS_INC(link.memerr);
    LINK_STATS_INC(link.drop);
  }

  return p;
}
Example #23
0
/**
 * The initial input processing of TCP. It verifies the TCP header, demultiplexes
 * the segment between the PCBs and passes it on to tcp_process(), which implements
 * the TCP finite state machine. This function is called by the IP layer (in
 * ip_input()).
 *
 * @param p received TCP segment to process (p->payload pointing to the IP header)
 * @param inp network interface on which this segment was received
 */
void
tcp_input(struct pbuf *p, struct netif *inp)
{
  struct tcp_pcb *pcb, *prev;
  struct tcp_pcb_listen *lpcb;
  u8_t hdrlen;
  err_t err;

  PERF_START;

  TCP_STATS_INC(tcp.recv);
  snmp_inc_tcpinsegs();

  iphdr = p->payload;
  tcphdr = (struct tcp_hdr *)((u8_t *)p->payload + IPH_HL(iphdr) * 4);

#if TCP_INPUT_DEBUG
  tcp_debug_print(tcphdr);
#endif

  /* remove header from payload */
  if (pbuf_header(p, -((s16_t)(IPH_HL(iphdr) * 4))) || (p->tot_len < sizeof(struct tcp_hdr))) {
    /* drop short packets */
    LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet (%"U16_F" bytes) discarded\n", p->tot_len));
    TCP_STATS_INC(tcp.lenerr);
    TCP_STATS_INC(tcp.drop);
    snmp_inc_tcpinerrs();
    pbuf_free(p);
    return;
  }

  /* Don't even process incoming broadcasts/multicasts. */
  if (ip_addr_isbroadcast(&(iphdr->dest), inp) ||
      ip_addr_ismulticast(&(iphdr->dest))) {
    TCP_STATS_INC(tcp.proterr);
    TCP_STATS_INC(tcp.drop);
    snmp_inc_tcpinerrs();
    pbuf_free(p);
    return;
  }

#if CHECKSUM_CHECK_TCP
  /* Verify TCP checksum. */
  if (inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src),
      (struct ip_addr *)&(iphdr->dest),
      IP_PROTO_TCP, p->tot_len) != 0) {
      LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packet discarded due to failing checksum 0x%04"X16_F"\n",
        inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src), (struct ip_addr *)&(iphdr->dest),
      IP_PROTO_TCP, p->tot_len)));
#if TCP_DEBUG
    tcp_debug_print(tcphdr);
#endif /* TCP_DEBUG */
    TCP_STATS_INC(tcp.chkerr);
    TCP_STATS_INC(tcp.drop);
    snmp_inc_tcpinerrs();
    pbuf_free(p);
    return;
  }
#endif

  /* Move the payload pointer in the pbuf so that it points to the
     TCP data instead of the TCP header. */
  hdrlen = TCPH_HDRLEN(tcphdr);
  if(pbuf_header(p, -(hdrlen * 4))){
    /* drop short packets */
    LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet\n"));
    TCP_STATS_INC(tcp.lenerr);
    TCP_STATS_INC(tcp.drop);
    snmp_inc_tcpinerrs();
    pbuf_free(p);
    return;
  }

  /* Convert fields in TCP header to host byte order. */
  tcphdr->src = ntohs(tcphdr->src);
  tcphdr->dest = ntohs(tcphdr->dest);
  seqno = tcphdr->seqno = ntohl(tcphdr->seqno);
  ackno = tcphdr->ackno = ntohl(tcphdr->ackno);
  tcphdr->wnd = ntohs(tcphdr->wnd);

  flags = TCPH_FLAGS(tcphdr) & TCP_FLAGS;
  tcplen = p->tot_len + ((flags & TCP_FIN || flags & TCP_SYN)? 1: 0);

  /* Demultiplex an incoming segment. First, we check if it is destined
     for an active connection. */
  prev = NULL;


  for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
    LWIP_ASSERT("tcp_input: active pcb->state != CLOSED", pcb->state != CLOSED);
    LWIP_ASSERT("tcp_input: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
    LWIP_ASSERT("tcp_input: active pcb->state != LISTEN", pcb->state != LISTEN);
    if (pcb->remote_port == tcphdr->src &&
       pcb->local_port == tcphdr->dest &&
       ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)) &&
       ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest))) {

      /* Move this PCB to the front of the list so that subsequent
         lookups will be faster (we exploit locality in TCP segment
         arrivals). */
      LWIP_ASSERT("tcp_input: pcb->next != pcb (before cache)", pcb->next != pcb);
      if (prev != NULL) {
        prev->next = pcb->next;
        pcb->next = tcp_active_pcbs;
        tcp_active_pcbs = pcb;
      }
      LWIP_ASSERT("tcp_input: pcb->next != pcb (after cache)", pcb->next != pcb);
      break;
    }
    prev = pcb;
  }

  if (pcb == NULL) {
    /* If it did not go to an active connection, we check the connections
       in the TIME-WAIT state. */
    for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
      LWIP_ASSERT("tcp_input: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
      if (pcb->remote_port == tcphdr->src &&
         pcb->local_port == tcphdr->dest &&
         ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)) &&
         ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest))) {
        /* We don't really care enough to move this PCB to the front
           of the list since we are not very likely to receive that
           many segments for connections in TIME-WAIT. */
        LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for TIME_WAITing connection.\n"));
        tcp_timewait_input(pcb);
        pbuf_free(p);
        return;
      }
    }

  /* Finally, if we still did not get a match, we check all PCBs that
     are LISTENing for incoming connections. */
    prev = NULL;
    for(lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
      if ((ip_addr_isany(&(lpcb->local_ip)) ||
        ip_addr_cmp(&(lpcb->local_ip), &(iphdr->dest))) &&
        lpcb->local_port == tcphdr->dest) {
        /* Move this PCB to the front of the list so that subsequent
           lookups will be faster (we exploit locality in TCP segment
           arrivals). */
        if (prev != NULL) {
          ((struct tcp_pcb_listen *)prev)->next = lpcb->next;
                /* our successor is the remainder of the listening list */
          lpcb->next = tcp_listen_pcbs.listen_pcbs;
                /* put this listening pcb at the head of the listening list */
          tcp_listen_pcbs.listen_pcbs = lpcb;
        }

        LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for LISTENing connection.\n"));
        tcp_listen_input(lpcb);
        pbuf_free(p);
        return;
      }
      prev = (struct tcp_pcb *)lpcb;
    }
  }

#if TCP_INPUT_DEBUG
  LWIP_DEBUGF(TCP_INPUT_DEBUG, ("+-+-+-+-+-+-+-+-+-+-+-+-+-+- tcp_input: flags "));
  tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
  LWIP_DEBUGF(TCP_INPUT_DEBUG, ("-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n"));
#endif /* TCP_INPUT_DEBUG */


  if (pcb != NULL) {
    /* The incoming segment belongs to a connection. */
#if TCP_INPUT_DEBUG
#if TCP_DEBUG
    tcp_debug_print_state(pcb->state);
#endif /* TCP_DEBUG */
#endif /* TCP_INPUT_DEBUG */

    /* Set up a tcp_seg structure. */
    inseg.next = NULL;
    inseg.len = p->tot_len;
    inseg.dataptr = p->payload;
    inseg.p = p;
    inseg.tcphdr = tcphdr;

    recv_data = NULL;
    recv_flags = 0;

    /* If there is data which was previously "refused" by upper layer */
    if (pcb->refused_data != NULL) {
      /* Notify again application with data previously received. */
      LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: notify kept packet\n"));
      TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
      if (err == ERR_OK) {
        pcb->refused_data = NULL;
      } else {
        /* drop incoming packets, because pcb is "full" */
        LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: drop incoming packets, because pcb is \"full\"\n"));
        TCP_STATS_INC(tcp.drop);
        snmp_inc_tcpinerrs();
        pbuf_free(p);
        return;
      }
    }

    tcp_input_pcb = pcb;
    err = tcp_process(pcb);
    tcp_input_pcb = NULL;
    /* A return value of ERR_ABRT means that tcp_abort() was called
       and that the pcb has been freed. If so, we don't do anything. */
    if (err != ERR_ABRT) {
      if (recv_flags & TF_RESET) {
        /* TF_RESET means that the connection was reset by the other
           end. We then call the error callback to inform the
           application that the connection is dead before we
           deallocate the PCB. */
        TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_RST);
        tcp_pcb_remove(&tcp_active_pcbs, pcb);
        memp_free(MEMP_TCP_PCB, pcb);
      } else if (recv_flags & TF_CLOSED) {
        /* The connection has been closed and we will deallocate the
           PCB. */
        tcp_pcb_remove(&tcp_active_pcbs, pcb);
        memp_free(MEMP_TCP_PCB, pcb);
      } else {
        err = ERR_OK;
        /* If the application has registered a "sent" function to be
           called when new send buffer space is available, we call it
           now. */
        if (pcb->acked > 0) {
          TCP_EVENT_SENT(pcb, pcb->acked, err);
        }

        if (recv_data != NULL) {
          if(flags & TCP_PSH) {
            recv_data->flags |= PBUF_FLAG_PUSH;
          }

          /* Notify application that data has been received. */
          TCP_EVENT_RECV(pcb, recv_data, ERR_OK, err);

          /* If the upper layer can't receive this data, store it */
          if (err != ERR_OK) {
            pcb->refused_data = recv_data;
            LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: keep incoming packet, because pcb is \"full\"\n"));
          }
        }

        /* If a FIN segment was received, we call the callback
           function with a NULL buffer to indicate EOF. */
        if (recv_flags & TF_GOT_FIN) {
          TCP_EVENT_RECV(pcb, NULL, ERR_OK, err);
        }

        /* If there were no errors, we try to send something out. */
        if (err == ERR_OK) {
          tcp_output(pcb);
        }
      }
    }


    /* give up our reference to inseg.p */
    if (inseg.p != NULL)
    {
      pbuf_free(inseg.p);
      inseg.p = NULL;
    }
#if TCP_INPUT_DEBUG
#if TCP_DEBUG
    tcp_debug_print_state(pcb->state);
#endif /* TCP_DEBUG */
#endif /* TCP_INPUT_DEBUG */

  } else {

    /* If no matching PCB was found, send a TCP RST (reset) to the
       sender. */
    LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_input: no PCB match found, resetting.\n"));
    if (!(TCPH_FLAGS(tcphdr) & TCP_RST)) {
      TCP_STATS_INC(tcp.proterr);
      TCP_STATS_INC(tcp.drop);
      tcp_rst(ackno, seqno + tcplen,
        &(iphdr->dest), &(iphdr->src),
        tcphdr->dest, tcphdr->src);
    }
    pbuf_free(p);
  }

  LWIP_ASSERT("tcp_input: tcp_pcbs_sane()", tcp_pcbs_sane());
  PERF_STOP("tcp_input");
}
Example #24
0
err_t tcp_enqueue (
       struct tcp_pcb* pcb, void* arg, u16_t len,
       u8_t          flags, u8_t            copy,
       u8_t*       optdata, u8_t          optlen
      ) {

 struct pbuf*    p;
 struct tcp_seg* seg, *useg, *queue;
 u32_t           left, seqno;
 u16_t           seglen;
 void*           ptr;
 u8_t            queuelen;
 flags_t         lPCBFlags = pcb -> flags;
 int             iSegCNT   = 0;

 left = len;
 ptr  = arg;

 if ( len > pcb -> snd_buf ) return ERR_MEM;

 seqno    = pcb -> snd_lbb;
 queue    = NULL;
 queuelen = pcb -> snd_queuelen;

 if ( queuelen >= TCP_SND_QUEUELEN ) goto memerr;

 seg    = useg = NULL;
 seglen = 0;

 while ( !queue || left > 0 ) {

  if ( lPCBFlags & TF_EVENSEG ) {

   ++iSegCNT;

   seglen = left > pcb -> mss ? pcb -> mss
                              : (((iSegCNT%2) == 1)? ((left + 1) / 2): left);
  } else seglen = left > pcb -> mss ? pcb -> mss : left;

  seg = memp_malloc ( MEMP_TCP_SEG );

  if ( !seg ) goto memerr;

  seg -> next = NULL;
  seg -> p    = NULL;

  if ( !queue )
   useg = queue = seg;
  else {
   useg -> next = seg;
   useg         = seg;
  }  /* end else */

    if (optdata != NULL) {
      if ((seg->p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
        goto memerr;
      }
      ++queuelen;
      seg->dataptr = seg->p->payload;
    }
    else if (copy) {
      if ((seg->p = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_RAM)) == NULL) {
        LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_enqueue : could not allocate memory for pbuf copy size %u\n", seglen));
        goto memerr;
      }
      ++queuelen;
      if (arg != NULL) {
        mips_memcpy(seg->p->payload, ptr, seglen);
      }
      seg->dataptr = seg->p->payload;
    }
    /* do not copy data */
    else {

      /* first, allocate a pbuf for holding the data.
       * since the referenced data is available at least until it is sent out on the
       * link (as it has to be ACKed by the remote party) we can safely use PBUF_ROM
       * instead of PBUF_REF here.
       */
      if ((p = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_ROM)) == NULL) {
        LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_enqueue: could not allocate memory for zero-copy pbuf\n"));
        goto memerr;
      }
      ++queuelen;
      p->payload = ptr;
      seg->dataptr = ptr;

      /* Second, allocate a pbuf for the headers. */
      if ((seg->p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_RAM)) == NULL) {
        /* If allocation fails, we have to deallocate the data pbuf as
         * well. */
        pbuf_free(p);
        LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_enqueue: could not allocate memory for header pbuf\n"));
        goto memerr;
      }
      ++queuelen;

      /* Concatenate the headers and data pbufs together. */
      pbuf_cat(seg->p, p);
      p = NULL;
    }

    /* Now that there are more segments queued, we check again if the
    length of the queue exceeds the configured maximum. */
    if (queuelen > TCP_SND_QUEUELEN) {
      LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_enqueue: queue too long %u (%u)\n", queuelen, TCP_SND_QUEUELEN));
      goto memerr;
    }

    seg->len = seglen;

    if (pbuf_header(seg->p, TCP_HLEN)) {

      LWIP_DEBUGF(TCP_OUTPUT_DEBUG | 2, ("tcp_enqueue: no room for TCP header in pbuf.\n"));

      TCP_STATS_INC(tcp.err);
      goto memerr;
    }
    seg->tcphdr = seg->p->payload;
    seg->tcphdr->src = htons(pcb->local_port);
    seg->tcphdr->dest = htons(pcb->remote_port);
    seg->tcphdr->seqno = htonl(seqno);
    seg->tcphdr->urgp = 0;
    TCPH_FLAGS_SET(seg->tcphdr, flags);
    /* don't fill in tcphdr->ackno and tcphdr->wnd until later */

    /* Copy the options into the header, if they are present. */
    if (optdata == NULL) {
      TCPH_HDRLEN_SET(seg->tcphdr, 5);
    }
    else {
      TCPH_HDRLEN_SET(seg->tcphdr, (5 + optlen / 4));
      /* Copy options into data portion of segment.
       Options can thus only be sent in non data carrying
       segments such as SYN|ACK. */
      mips_memcpy(seg->dataptr, optdata, optlen);
    }

    left -= seglen;
    seqno += seglen;
    ptr = (void *)((char *)ptr + seglen);
  }


  /* Now that the data to be enqueued has been broken up into TCP
  segments in the queue variable, we add them to the end of the
  pcb->unsent queue. */
  if (pcb->unsent == NULL) {
    useg = NULL;
  }
  else {
    for (useg = pcb->unsent; useg->next != NULL; useg = useg->next);
  }

  /* If there is room in the last pbuf on the unsent queue,
  chain the first pbuf on the queue together with that. */
  if (useg != NULL &&
    TCP_TCPLEN(useg) != 0 &&
    !(TCPH_FLAGS(useg->tcphdr) & (TCP_SYN | TCP_FIN)) &&
    !(flags & (TCP_SYN | TCP_FIN)) &&
    useg->len + queue->len <= pcb->mss) {
    /* Remove TCP header from first segment. */
    pbuf_header(queue->p, -TCP_HLEN);
    pbuf_cat(useg->p, queue->p);
    useg->len += queue->len;
    useg->next = queue->next;

    if (seg == queue) seg = NULL;

    memp_free(MEMP_TCP_SEG, queue);
  }
  else {
    if (useg == NULL) {
      pcb->unsent = queue;

    }
    else {
      useg->next = queue;
    }
  }
  if ((flags & TCP_SYN) || (flags & TCP_FIN)) {
    ++len;
  }
  pcb->snd_lbb += len;
  pcb->snd_buf -= len;
  pcb->snd_queuelen = queuelen;
  LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_enqueue: %d (after enqueued)\n", pcb->snd_queuelen));
  if (pcb->snd_queuelen != 0) {
    LWIP_ASSERT("tcp_enqueue: valid queue length", pcb->unacked != NULL ||
      pcb->unsent != NULL);

  }

  /* Set the PSH flag in the last segment that we enqueued, but only
  if the segment has data (indicated by seglen > 0). */
  if (seg != NULL && seglen > 0 && seg->tcphdr != NULL) {
    TCPH_SET_FLAG(seg->tcphdr, TCP_PSH);
  }

  return ERR_OK;
  memerr:
  TCP_STATS_INC(tcp.memerr);

  if (queue != NULL) {
    tcp_segs_free(queue);
  }
  if (pcb->snd_queuelen != 0) {
    LWIP_ASSERT("tcp_enqueue: valid queue length", pcb->unacked != NULL ||
      pcb->unsent != NULL);

  }
  LWIP_DEBUGF(TCP_QLEN_DEBUG | DBG_STATE, ("tcp_enqueue: %d (with mem err)\n", pcb->snd_queuelen));
  return ERR_MEM;
}
Example #25
0
/**
 * Should allocate a pbuf and transfer the bytes of the incoming
 * packet from the interface into the pbuf.
 *
 * @param netif the lwip network interface structure for this ethernetif
 * @return a pbuf filled with the received packet (including MAC header)
 *         NULL on memory error
 */
static struct pbuf *low_level_input(struct netif *netif)
{
    struct pbuf *p, *q;
    int32_t len;
    int l = 0;

    /* Obtain the size of the packet and put it into the "len"
       variable. */
    len = csi_eth_mac_ex_read_frame_begin(eth_mac_handle);

    if (len < 0) {
        /* errors in rx buffer, reset enc28j60 */
        LOGE(TAG, "recv frame error");
        g_continue_rx_error++;

        if (g_continue_rx_error >= 3) {
#if defined(CONFIG_SELF_RECOVER)
            //yoc_recover_send_event(YOC_EXP_ETH(YOC_RCV_RXERR), YOC_RCV_ACT_REBOOT, YOC_UNRCV_ACT_SLEEP);
#endif
        }

        // TODO: power off/on ethernet card
        yoc_nic_reset();

        return NULL;
    } else if (len == 0) {
        return NULL;
    }

    g_continue_rx_error = 0;

#if ETH_PAD_SIZE
    len += ETH_PAD_SIZE; /* allow room for Ethernet padding */
#endif

    /* We allocate a pbuf chain of pbufs from the pool. */
    p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);

    if (p != NULL) {

#if ETH_PAD_SIZE
        pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
#endif

        /* We iterate over the pbuf chain until we have read the entire
         * packet into the pbuf. */
        for (q = p; q != NULL; q = q->next) {
            /* Read enough bytes to fill this pbuf in the chain. The
             * available data in the pbuf is given by the q->len
             * variable.
             * This does not necessarily have to be a memcpy, you can also preallocate
             * pbufs for a DMA-enabled MAC and after receiving truncate it to the
             * actually received size. In this case, ensure the tot_len member of the
             * pbuf is the sum of the chained pbuf len members.
             */
            /* read data into(q->payload, q->len); */
            csi_eth_mac_ex_read_frame(eth_mac_handle, (u8_t *)q->payload, q->len);
            l = l + q->len;
        }

        csi_eth_mac_ex_read_frame_end(eth_mac_handle);

        MIB2_STATS_NETIF_ADD(netif, ifinoctets, p->tot_len);

        if (((u8_t *)p->payload)[0] & 1) {
            /* broadcast or multicast packet */
            MIB2_STATS_NETIF_INC(netif, ifinnucastpkts);
        } else {
            /* unicast packet */
            MIB2_STATS_NETIF_INC(netif, ifinucastpkts);
        }

#if ETH_PAD_SIZE
        pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
#endif

        LINK_STATS_INC(link.recv);
    } else {
        LOGI(TAG, "err alloc pbuf");
        /* drop packet(); */
        csi_eth_mac_ex_read_frame_end(eth_mac_handle);
        LINK_STATS_INC(link.memerr);
        LINK_STATS_INC(link.drop);
        MIB2_STATS_NETIF_INC(netif, ifindiscards);
    }

    return p;
}
Example #26
0
/**
 * ICMP Echo Request in pbuf "p" is to be proxied.
 */
static void
pxping_recv4(void *arg, struct pbuf *p)
{
    struct pxping *pxping = (struct pxping *)arg;
    const struct ip_hdr *iph;
    const struct icmp_echo_hdr *icmph;
    u16_t iphlen;
    size_t bufsize;
    struct pong4 *pong;
    IPAddr dst;
    int mapped;
    int ttl;
    IP_OPTION_INFORMATION opts;
    void *reqdata;
    size_t reqsize;
    int status;

    pong = NULL;

    iphlen = ip_current_header_tot_len();
    if (RT_UNLIKELY(iphlen != IP_HLEN)) { /* we don't do options */
        goto out;
    }

    iph = (const struct ip_hdr *)ip_current_header();
    icmph = (const struct icmp_echo_hdr *)p->payload;

    mapped = pxremap_outbound_ip4((ip_addr_t *)&dst, (ip_addr_t *)&iph->dest);
    if (RT_UNLIKELY(mapped == PXREMAP_FAILED)) {
        goto out;
    }

    ttl = IPH_TTL(iph);
    if (mapped == PXREMAP_ASIS) {
        if (RT_UNLIKELY(ttl == 1)) {
            status = pbuf_header(p, iphlen); /* back to IP header */
            if (RT_LIKELY(status == 0)) {
                icmp_time_exceeded(p, ICMP_TE_TTL);
            }
            goto out;
        }
        --ttl;
    }

    status = pbuf_header(p, -(u16_t)sizeof(*icmph)); /* to ping payload */
    if (RT_UNLIKELY(status != 0)) {
        goto out;
    }

    bufsize = sizeof(ICMP_ECHO_REPLY) + p->tot_len;
    pong = (struct pong4 *)malloc(sizeof(*pong) - sizeof(pong->buf) + bufsize);
    if (RT_UNLIKELY(pong == NULL)) {
        goto out;
    }
    pong->bufsize = bufsize;
    pong->netif = pxping->netif;

    memcpy(&pong->reqiph, iph, sizeof(*iph));
    memcpy(&pong->reqicmph, icmph, sizeof(*icmph));

    reqsize = p->tot_len;
    if (p->next == NULL) {
        /* single pbuf can be directly used as request data source */
        reqdata = p->payload;
    }
    else {
        /* data from pbuf chain must be concatenated */
        pbuf_copy_partial(p, pong->buf, p->tot_len, 0);
        reqdata = pong->buf;
    }

    opts.Ttl = ttl;
    opts.Tos = IPH_TOS(iph); /* affected by DisableUserTOSSetting key */
    opts.Flags = (IPH_OFFSET(iph) & PP_HTONS(IP_DF)) != 0 ? IP_FLAG_DF : 0;
    opts.OptionsSize = 0;
    opts.OptionsData = 0;

    status = IcmpSendEcho2(pxping->hdl4, NULL,
                           pxping->callback4, pong,
                           dst, reqdata, (WORD)reqsize, &opts,
                           pong->buf, (DWORD)pong->bufsize,
                           5 * 1000 /* ms */);

    if (RT_UNLIKELY(status != 0)) {
        DPRINTF(("IcmpSendEcho2: unexpected status %d\n", status));
        goto out;
    }
    else if ((status = GetLastError()) != ERROR_IO_PENDING) {
        int code;

        DPRINTF(("IcmpSendEcho2: error %d\n", status));
        switch (status) {
        case ERROR_NETWORK_UNREACHABLE:
            code = ICMP_DUR_NET;
            break;
        case ERROR_HOST_UNREACHABLE:
            code = ICMP_DUR_HOST;
            break;
        default:
            code = -1;
            break;
        }

        if (code != -1) {
            /* move payload back to IP header */
            status = pbuf_header(p, (u16_t)(sizeof(*icmph) + iphlen));
            if (RT_LIKELY(status == 0)) {
                icmp_dest_unreach(p, code);
            }
        }
        goto out;
    }

    pong = NULL;                /* callback owns it now */
  out:
    if (pong != NULL) {
        free(pong);
    }
    pbuf_free(p);
}
Example #27
0
/* lwIP UDP receive callback function */
static void
snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port)
{
  struct udp_hdr *udphdr;

  /* suppress unused argument warning */
  LWIP_UNUSED_ARG(arg);
  /* peek in the UDP header (goto IP payload) */
  if(pbuf_header(p, UDP_HLEN)){
    LWIP_ASSERT("Can't move to UDP header", 0);
    pbuf_free(p);
    return;
  }
  udphdr = p->payload;

  /* check if datagram is really directed at us (including broadcast requests) */
  if ((pcb == snmp1_pcb) && (ntohs(udphdr->dest) == SNMP_IN_PORT))
  {
    struct snmp_msg_pstat *msg_ps;
    u8_t req_idx;

    /* traverse input message process list, look for SNMP_MSG_EMPTY */
    msg_ps = &msg_input_list[0];
    req_idx = 0;
    while ((req_idx<SNMP_CONCURRENT_REQUESTS) && (msg_ps->state != SNMP_MSG_EMPTY))
    {
      req_idx++;
      msg_ps++;
    }
    if (req_idx != SNMP_CONCURRENT_REQUESTS)
    {
      err_t err_ret;
      u16_t payload_len;
      u16_t payload_ofs;
      u16_t varbind_ofs = 0;

      /* accepting request */
      snmp_inc_snmpinpkts();
      /* record used 'protocol control block' */
      msg_ps->pcb = pcb;
      /* source address (network order) */
      msg_ps->sip = *addr;
      /* source port (host order (lwIP oddity)) */
      msg_ps->sp = port;
      /* read UDP payload length from UDP header */
      payload_len = ntohs(udphdr->len) - UDP_HLEN;

      /* adjust to UDP payload */
      payload_ofs = UDP_HLEN;

      /* check total length, version, community, pdu type */
      err_ret = snmp_pdu_header_check(p, payload_ofs, payload_len, &varbind_ofs, msg_ps);
      if (((msg_ps->rt == SNMP_ASN1_PDU_GET_REQ) ||
           (msg_ps->rt == SNMP_ASN1_PDU_GET_NEXT_REQ) ||
           (msg_ps->rt == SNMP_ASN1_PDU_SET_REQ)) &&
          ((msg_ps->error_status == SNMP_ES_NOERROR) &&
           (msg_ps->error_index == 0)) )
      {
        /* Only accept requests and requests without error (be robust) */
        err_ret = err_ret;
      }
      else
      {
        /* Reject response and trap headers or error requests as input! */
        err_ret = ERR_ARG;
      }
      if (err_ret == ERR_OK)
      {
        LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv ok, community %s\n", msg_ps->community));

        /* Builds a list of variable bindings. Copy the varbinds from the pbuf
          chain to glue them when these are divided over two or more pbuf's. */
        err_ret = snmp_pdu_dec_varbindlist(p, varbind_ofs, &varbind_ofs, msg_ps);
        if ((err_ret == ERR_OK) && (msg_ps->invb.count > 0))
        {
          /* we've decoded the incoming message, release input msg now */
          pbuf_free(p);

          msg_ps->error_status = SNMP_ES_NOERROR;
          msg_ps->error_index = 0;
          /* find object for each variable binding */
          msg_ps->state = SNMP_MSG_SEARCH_OBJ;
          /* first variable binding from list to inspect */
          msg_ps->vb_idx = 0;

          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv varbind cnt=%"U16_F"\n",(u16_t)msg_ps->invb.count));

          /* handle input event and as much objects as possible in one go */
          snmp_msg_event(req_idx);
        }
        else
        {
          /* varbind-list decode failed, or varbind list empty.
             drop request silently, do not return error!
             (errors are only returned for a specific varbind failure) */
          pbuf_free(p);
          LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_dec_varbindlist() failed\n"));
        }
      }
      else
      {
        /* header check failed
           drop request silently, do not return error! */
        pbuf_free(p);
        LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_header_check() failed\n"));
      }
    }
    else
    {
      /* exceeding number of concurrent requests */
      pbuf_free(p);
    }
  }
  else
  {
    /* datagram not for us */
    pbuf_free(p);
  }
}
Example #28
0
static void
pxping_recv6(void *arg, struct pbuf *p)
{
    struct pxping *pxping = (struct pxping *)arg;
    struct icmp6_echo_hdr *icmph;
    size_t bufsize;
    struct pong6 *pong;
    int mapped;
    void *reqdata;
    size_t reqsize;
    struct sockaddr_in6 src, dst;
    int hopl;
    IP_OPTION_INFORMATION opts;
    int status;

    pong = NULL;

    icmph = (struct icmp6_echo_hdr *)p->payload;

    memset(&dst, 0, sizeof(dst));
    dst.sin6_family = AF_INET6;
    mapped = pxremap_outbound_ip6((ip6_addr_t *)&dst.sin6_addr,
                                  ip6_current_dest_addr());
    if (RT_UNLIKELY(mapped == PXREMAP_FAILED)) {
        goto out;
    }

    hopl = IP6H_HOPLIM(ip6_current_header());
    if (mapped == PXREMAP_ASIS) {
        if (RT_UNLIKELY(hopl == 1)) {
            status = pbuf_header(p, ip_current_header_tot_len());
            if (RT_LIKELY(status == 0)) {
                icmp6_time_exceeded(p, ICMP6_TE_HL);
            }
            goto out;
        }
        --hopl;
    }

    status = pbuf_header(p, -(u16_t)sizeof(*icmph)); /* to ping payload */
    if (RT_UNLIKELY(status != 0)) {
        goto out;
    }

    bufsize = sizeof(ICMPV6_ECHO_REPLY) + p->tot_len;
    pong = (struct pong6 *)malloc(sizeof(*pong) - sizeof(pong->buf) + bufsize);
    if (RT_UNLIKELY(pong == NULL)) {
        goto out;
    }
    pong->bufsize = bufsize;
    pong->netif = pxping->netif;

    ip6_addr_copy(pong->reqsrc, *ip6_current_src_addr());
    memcpy(&pong->reqicmph, icmph, sizeof(*icmph));

    memset(pong->buf, 0xa5, pong->bufsize);

    pong->reqsize = reqsize = p->tot_len;
    if (p->next == NULL) {
        /* single pbuf can be directly used as request data source */
        reqdata = p->payload;
    }
    else {
        /* data from pbuf chain must be concatenated */
        pbuf_copy_partial(p, pong->buf, p->tot_len, 0);
        reqdata = pong->buf;
    }

    memset(&src, 0, sizeof(src));
    src.sin6_family = AF_INET6;
    src.sin6_addr = in6addr_any; /* let the OS select host source address */

    memset(&opts, 0, sizeof(opts));
    opts.Ttl = hopl;

    status = Icmp6SendEcho2(pxping->hdl6, NULL,
                            pxping->callback6, pong,
                            &src, &dst, reqdata, (WORD)reqsize, &opts,
                            pong->buf, (DWORD)pong->bufsize,
                            5 * 1000 /* ms */);

    if (RT_UNLIKELY(status != 0)) {
        DPRINTF(("Icmp6SendEcho2: unexpected status %d\n", status));
        goto out;
    }
    else if ((status = GetLastError()) != ERROR_IO_PENDING) {
        int code;

        DPRINTF(("Icmp6SendEcho2: error %d\n", status));
        switch (status) {
        case ERROR_NETWORK_UNREACHABLE:
        case ERROR_HOST_UNREACHABLE:
            code = ICMP6_DUR_NO_ROUTE;
            break;
        default:
            code = -1;
            break;
        }

        if (code != -1) {
            /* move payload back to IP header */
            status = pbuf_header(p, (u16_t)(sizeof(*icmph)
                                            + ip_current_header_tot_len()));
            if (RT_LIKELY(status == 0)) {
                icmp6_dest_unreach(p, code);
            }
        }
        goto out;
    }
    
    pong = NULL;                /* callback owns it now */
  out:
    if (pong != NULL) {
        free(pong);
    }
    pbuf_free(p);
}
Example #29
0
/**
 * Send the raw IP packet to the given address. Note that actually you cannot
 * modify the IP headers (this is inconsistent with the receive callback where
 * you actually get the IP headers), you can only specify the IP payload here.
 * It requires some more changes in lwIP. (there will be a raw_send() function
 * then.)
 *
 * @param pcb the raw pcb which to send
 * @param p the IP payload to send
 * @param ipaddr the destination address of the IP packet
 *
 */
err_t
raw_sendto(struct raw_pcb *pcb, struct pbuf *p, const ip_addr_t *ipaddr)
{
  err_t err;
  struct netif *netif;
  const ip_addr_t *src_ip;
  struct pbuf *q; /* q will be sent down the stack */
  s16_t header_size;
  const ip_addr_t *dst_ip = ipaddr;

  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
    return ERR_VAL;
  }

  LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_sendto\n"));

  header_size = (
#if LWIP_IPV4 && LWIP_IPV6
    PCB_ISIPV6(pcb) ? IP6_HLEN : IP_HLEN);
#elif LWIP_IPV4
    IP_HLEN);
#else
    IP6_HLEN);
#endif

  /* not enough space to add an IP header to first pbuf in given p chain? */
  if (pbuf_header(p, header_size)) {
    /* allocate header in new pbuf */
    q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM);
    /* new header pbuf could not be allocated? */
    if (q == NULL) {
      LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("raw_sendto: could not allocate header\n"));
      return ERR_MEM;
    }
    if (p->tot_len != 0) {
      /* chain header q in front of given pbuf p */
      pbuf_chain(q, p);
    }
    /* { first pbuf q points to header pbuf } */
    LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
  } else {
    /* first pbuf q equals given pbuf */
    q = p;
    if (pbuf_header(q, -header_size)) {
      LWIP_ASSERT("Can't restore header we just removed!", 0);
      return ERR_MEM;
    }
  }

  netif = ip_route(PCB_ISIPV6(pcb), &pcb->local_ip, dst_ip);
  if (netif == NULL) {
    LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: No route to "));
    ip_addr_debug_print(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, dst_ip);
    /* free any temporary header pbuf allocated by pbuf_header() */
    if (q != p) {
      pbuf_free(q);
    }
    return ERR_RTE;
  }

#if IP_SOF_BROADCAST
  if (!PCB_ISIPV6(pcb))
  {
    /* broadcast filter? */
    if (!ip_get_option(pcb, SOF_BROADCAST) && ip_addr_isbroadcast(ipaddr, netif)) {
      LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb));
      /* free any temporary header pbuf allocated by pbuf_header() */
      if (q != p) {
        pbuf_free(q);
      }
      return ERR_VAL;
    }
  }
#endif /* IP_SOF_BROADCAST */

  if (ip_addr_isany(&pcb->local_ip)) {
    /* use outgoing network interface IP address as source address */
    src_ip = ip_netif_get_local_ip(PCB_ISIPV6(pcb), netif, dst_ip);
#if LWIP_IPV6
    if (src_ip == NULL) {
      if (q != p) {
        pbuf_free(q);
      }
      return ERR_RTE;
    }
#endif /* LWIP_IPV6 */
  } else {
    /* use RAW PCB local IP address as source address */
    src_ip = &pcb->local_ip;
  }

#if LWIP_IPV6
  /* If requested, based on the IPV6_CHECKSUM socket option per RFC3542,
     compute the checksum and update the checksum in the payload. */
  if (PCB_ISIPV6(pcb) && pcb->chksum_reqd) {
    u16_t chksum = ip6_chksum_pseudo(p, pcb->protocol, p->tot_len, ip_2_ip6(src_ip), ip_2_ip6(dst_ip));
    LWIP_ASSERT("Checksum must fit into first pbuf", p->len >= (pcb->chksum_offset + 2));
    SMEMCPY(((u8_t *)p->payload) + pcb->chksum_offset, &chksum, sizeof(u16_t));
  }
#endif

  NETIF_SET_HWADDRHINT(netif, &pcb->addr_hint);
  err = ip_output_if(PCB_ISIPV6(pcb), q, src_ip, dst_ip, pcb->ttl, pcb->tos, pcb->protocol, netif);
  NETIF_SET_HWADDRHINT(netif, NULL);

  /* did we chain a header earlier? */
  if (q != p) {
    /* free the header */
    pbuf_free(q);
  }
  return err;
}
err_t
ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
             u8_t ttl, u8_t tos,
             u8_t proto, struct netif *netif)
{
  struct ip_hdr *iphdr;
  u16_t ip_id = 0;

  snmp_inc_ipoutrequests();

  if (dest != IP_HDRINCL) {
    if (pbuf_header(p, IP_HLEN)) {
      LWIP_DEBUGF(IP_DEBUG | 2, ("ip_output: not enough room for IP header in pbuf\n"));

      IP_STATS_INC(ip.err);
      snmp_inc_ipoutdiscards();
      return ERR_BUF;
    }

    iphdr = p->payload;

    IPH_TTL_SET(iphdr, ttl);
    IPH_PROTO_SET(iphdr, proto);

    ip_addr_set(&(iphdr->dest), dest);

    IPH_VHLTOS_SET(iphdr, 4, IP_HLEN / 4, tos);
    IPH_LEN_SET(iphdr, htons(p->tot_len));
    IPH_OFFSET_SET(iphdr, htons(IP_DF));
    IPH_ID_SET(iphdr, htons(ip_id));
    ++ip_id;

    if (ip_addr_isany(src)) {
      ip_addr_set(&(iphdr->src), &(netif->ip_addr));
    } else {
      ip_addr_set(&(iphdr->src), src);
    }

    IPH_CHKSUM_SET(iphdr, 0);
#if CHECKSUM_GEN_IP
    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
#endif
  } else {
    iphdr = p->payload;
    dest = &(iphdr->dest);
  }

#if IP_FRAG
  /* don't fragment if interface has mtu set to 0 [loopif] */
  if (netif->mtu && (p->tot_len > netif->mtu))
    return ip_frag(p,netif,dest);
#endif

  IP_STATS_INC(ip.xmit);

  LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%u\n", netif->name[0], netif->name[1], netif->num));
  ip_debug_print(p);

  LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));

  return netif->output(netif, p, dest);
}