Exemplo n.º 1
0
/* Print an IPv6 header by using LWIP_DEBUGF
 * @param p an IPv6 packet, p->payload pointing to the IPv6 header
 */
void
ip6_debug_print(struct pbuf *p)
{
  struct ip6_hdr *ip6hdr = (struct ip6_hdr *)p->payload;

  LWIP_UNUSED_ARG(ip6hdr);

  LWIP_DEBUGF(IP6_DEBUG, ("IPv6 header:\n"));
  LWIP_DEBUGF(IP6_DEBUG, ("+-------------------------------+\n"));
  LWIP_DEBUGF(IP6_DEBUG, ("| %2"U16_F" |  %3"U16_F"  |      %7"U32_F"     | (ver, class, flow)\n",
                    IP6H_V(ip6hdr),
                    IP6H_TC(ip6hdr),
                    IP6H_FL(ip6hdr)));
  LWIP_DEBUGF(IP6_DEBUG, ("+-------------------------------+\n"));
  LWIP_DEBUGF(IP6_DEBUG, ("|     %5"U16_F"     |  %3"U16_F"  |  %3"U16_F"  | (plen, nexth, hopl)\n",
                    IP6H_PLEN(ip6hdr),
                    IP6H_NEXTH(ip6hdr),
                    IP6H_HOPLIM(ip6hdr)));
  LWIP_DEBUGF(IP6_DEBUG, ("+-------------------------------+\n"));
  LWIP_DEBUGF(IP6_DEBUG, ("|  %4"X32_F" |  %4"X32_F" |  %4"X32_F" |  %4"X32_F" | (src)\n",
                    IP6_ADDR_BLOCK1(&(ip6hdr->src)),
                    IP6_ADDR_BLOCK2(&(ip6hdr->src)),
                    IP6_ADDR_BLOCK3(&(ip6hdr->src)),
                    IP6_ADDR_BLOCK4(&(ip6hdr->src))));
  LWIP_DEBUGF(IP6_DEBUG, ("|  %4"X32_F" |  %4"X32_F" |  %4"X32_F" |  %4"X32_F" |\n",
                    IP6_ADDR_BLOCK5(&(ip6hdr->src)),
                    IP6_ADDR_BLOCK6(&(ip6hdr->src)),
                    IP6_ADDR_BLOCK7(&(ip6hdr->src)),
                    IP6_ADDR_BLOCK8(&(ip6hdr->src))));
  LWIP_DEBUGF(IP6_DEBUG, ("+-------------------------------+\n"));
  LWIP_DEBUGF(IP6_DEBUG, ("|  %4"X32_F" |  %4"X32_F" |  %4"X32_F" |  %4"X32_F" | (dest)\n",
                    IP6_ADDR_BLOCK1(&(ip6hdr->dest)),
                    IP6_ADDR_BLOCK2(&(ip6hdr->dest)),
                    IP6_ADDR_BLOCK3(&(ip6hdr->dest)),
                    IP6_ADDR_BLOCK4(&(ip6hdr->dest))));
  LWIP_DEBUGF(IP6_DEBUG, ("|  %4"X32_F" |  %4"X32_F" |  %4"X32_F" |  %4"X32_F" |\n",
                    IP6_ADDR_BLOCK5(&(ip6hdr->dest)),
                    IP6_ADDR_BLOCK6(&(ip6hdr->dest)),
                    IP6_ADDR_BLOCK7(&(ip6hdr->dest)),
                    IP6_ADDR_BLOCK8(&(ip6hdr->dest))));
  LWIP_DEBUGF(IP6_DEBUG, ("+-------------------------------+\n"));
}
/**
 * This function is called by the network interface device driver when
 * an IPv6 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 ip6_forward).
 *
 * Finally, the packet is sent to the upper layer protocol input function.
 *
 * @param p the received IPv6 packet (p->payload points to IPv6 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
ip6_input(struct pbuf *p, struct netif *inp)
{
  struct ip6_hdr *ip6hdr;
  struct netif *netif;
  u8_t nexth;
  u16_t hlen; /* the current header length */
  u8_t i;
#if 0 /*IP_ACCEPT_LINK_LAYER_ADDRESSING*/
  @todo
  int check_ip_src=1;
#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */

  IP6_STATS_INC(ip6.recv);

  /* identify the IP header */
  ip6hdr = (struct ip6_hdr *)p->payload;
  if (IP6H_V(ip6hdr) != 6) {
    LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IPv6 packet dropped due to bad version number %"U32_F"\n",
        IP6H_V(ip6hdr)));
    pbuf_free(p);
    IP6_STATS_INC(ip6.err);
    IP6_STATS_INC(ip6.drop);
    return ERR_OK;
  }

#ifdef LWIP_HOOK_IP6_INPUT
  if (LWIP_HOOK_IP6_INPUT(p, inp)) {
    /* the packet has been eaten */
    return ERR_OK;
  }
#endif

  /* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
  if ((IP6_HLEN > p->len) || ((IP6H_PLEN(ip6hdr) + IP6_HLEN) > p->tot_len)) {
    if (IP6_HLEN > p->len) {
      LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
        ("IPv6 header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
            IP6_HLEN, p->len));
    }
    if ((IP6H_PLEN(ip6hdr) + IP6_HLEN) > p->tot_len) {
      LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
        ("IPv6 (plen %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
            IP6H_PLEN(ip6hdr) + IP6_HLEN, p->tot_len));
    }
    /* free (drop) packet pbufs */
    pbuf_free(p);
    IP6_STATS_INC(ip6.lenerr);
    IP6_STATS_INC(ip6.drop);
    return ERR_OK;
  }

  /* 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, IP6_HLEN + IP6H_PLEN(ip6hdr));

  /* copy IP addresses to aligned ip6_addr_t */
  ip_addr_copy_from_ip6(ip_data.current_iphdr_dest, ip6hdr->dest);
  ip_addr_copy_from_ip6(ip_data.current_iphdr_src, ip6hdr->src);

  /* current header pointer. */
  ip_data.current_ip6_header = ip6hdr;

  /* In netif, used in case we need to send ICMPv6 packets back. */
  ip_data.current_netif = inp;
  ip_data.current_input_netif = inp;

  /* match packet against an interface, i.e. is this packet for us? */
  if (ip6_addr_ismulticast(ip6_current_dest_addr())) {
    /* Always joined to multicast if-local and link-local all-nodes group. */
    if (ip6_addr_isallnodes_iflocal(ip6_current_dest_addr()) ||
        ip6_addr_isallnodes_linklocal(ip6_current_dest_addr())) {
      netif = inp;
    }
#if LWIP_IPV6_MLD
    else if (mld6_lookfor_group(inp, ip6_current_dest_addr())) {
      netif = inp;
    }
#else /* LWIP_IPV6_MLD */
    else if (ip6_addr_issolicitednode(ip6_current_dest_addr())) {
      /* Filter solicited node packets when MLD is not enabled
       * (for Neighbor discovery). */
      netif = NULL;
      for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
        if (ip6_addr_isvalid(netif_ip6_addr_state(inp, i)) &&
            ip6_addr_cmp_solicitednode(ip6_current_dest_addr(), netif_ip6_addr(inp, i))) {
          netif = inp;
          LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: solicited node packet accepted on interface %c%c\n",
              netif->name[0], netif->name[1]));
          break;
        }
      }
    }
#endif /* LWIP_IPV6_MLD */
    else {
      netif = NULL;
    }
  } else {
    /* 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 {
      /* interface is up? */
      if (netif_is_up(netif)) {
        /* unicast to this interface address? address configured? */
        for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
          if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
              ip6_addr_cmp(ip6_current_dest_addr(), netif_ip6_addr(netif, i))) {
            /* exit outer loop */
            goto netif_found;
          }
        }
      }
      if (ip6_addr_islinklocal(ip6_current_dest_addr())) {
        /* Do not match link-local addresses to other netifs. */
        netif = NULL;
        break;
      }
      if (first) {
        first = 0;
        netif = netif_list;
      } else {
        netif = netif->next;
      }
      if (netif == inp) {
        netif = netif->next;
      }
    } while (netif != NULL);
netif_found:
    LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet accepted on interface %c%c\n",
        netif ? netif->name[0] : 'X', netif? netif->name[1] : 'X'));
  }

  /* "::" packet source address? (used in duplicate address detection) */
  if (ip6_addr_isany(ip6_current_src_addr()) &&
      (!ip6_addr_issolicitednode(ip6_current_dest_addr()))) {
    /* packet source is not valid */
    /* free (drop) packet pbufs */
    LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with src ANY_ADDRESS dropped\n"));
    pbuf_free(p);
    IP6_STATS_INC(ip6.drop);
    goto ip6_input_cleanup;
  }

  /* packet not for us? */
  if (netif == NULL) {
    /* packet not for us, route or discard */
    LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_TRACE, ("ip6_input: packet not for us.\n"));
#if LWIP_IPV6_FORWARD
    /* non-multicast packet? */
    if (!ip6_addr_ismulticast(ip6_current_dest_addr())) {
      /* try to forward IP packet on (other) interfaces */
      ip6_forward(p, ip6hdr, inp);
    }
#endif /* LWIP_IPV6_FORWARD */
    pbuf_free(p);
    goto ip6_input_cleanup;
  }

  /* current netif pointer. */
  ip_data.current_netif = netif;

  /* Save next header type. */
  nexth = IP6H_NEXTH(ip6hdr);

  /* Init header length. */
  hlen = ip_data.current_ip_header_tot_len = IP6_HLEN;

  /* Move to payload. */
  pbuf_header(p, -IP6_HLEN);

  /* Process known option extension headers, if present. */
  while (nexth != IP6_NEXTH_NONE)
  {
    switch (nexth) {
    case IP6_NEXTH_HOPBYHOP:
      LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Hop-by-Hop options header\n"));
      /* Get next header type. */
      nexth = *((u8_t *)p->payload);

      /* Get the header length. */
      hlen = 8 * (1 + *((u8_t *)p->payload + 1));
      ip_data.current_ip_header_tot_len += hlen;

      /* Skip over this header. */
      if (hlen > p->len) {
        LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
          ("IPv6 options header (hlen %"U16_F") does not fit in first pbuf (len %"U16_F"), IPv6 packet dropped.\n",
              hlen, p->len));
        /* free (drop) packet pbufs */
        pbuf_free(p);
        IP6_STATS_INC(ip6.lenerr);
        IP6_STATS_INC(ip6.drop);
        goto ip6_input_cleanup;
      }

      pbuf_header(p, -(s16_t)hlen);
      break;
    case IP6_NEXTH_DESTOPTS:
      LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Destination options header\n"));
      /* Get next header type. */
      nexth = *((u8_t *)p->payload);

      /* Get the header length. */
      hlen = 8 * (1 + *((u8_t *)p->payload + 1));
      ip_data.current_ip_header_tot_len += hlen;

      /* Skip over this header. */
      if (hlen > p->len) {
        LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
          ("IPv6 options header (hlen %"U16_F") does not fit in first pbuf (len %"U16_F"), IPv6 packet dropped.\n",
              hlen, p->len));
        /* free (drop) packet pbufs */
        pbuf_free(p);
        IP6_STATS_INC(ip6.lenerr);
        IP6_STATS_INC(ip6.drop);
        goto ip6_input_cleanup;
      }

      pbuf_header(p, -(s16_t)hlen);
      break;
    case IP6_NEXTH_ROUTING:
      LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Routing header\n"));
      /* Get next header type. */
      nexth = *((u8_t *)p->payload);

      /* Get the header length. */
      hlen = 8 * (1 + *((u8_t *)p->payload + 1));
      ip_data.current_ip_header_tot_len += hlen;

      /* Skip over this header. */
      if (hlen > p->len) {
        LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
          ("IPv6 options header (hlen %"U16_F") does not fit in first pbuf (len %"U16_F"), IPv6 packet dropped.\n",
              hlen, p->len));
        /* free (drop) packet pbufs */
        pbuf_free(p);
        IP6_STATS_INC(ip6.lenerr);
        IP6_STATS_INC(ip6.drop);
        goto ip6_input_cleanup;
      }

      pbuf_header(p, -(s16_t)hlen);
      break;

    case IP6_NEXTH_FRAGMENT:
    {
      struct ip6_frag_hdr * frag_hdr;
      LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Fragment header\n"));

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

      /* Get next header type. */
      nexth = frag_hdr->_nexth;

      /* Fragment Header length. */
      hlen = 8;
      ip_data.current_ip_header_tot_len += hlen;

      /* Make sure this header fits in current pbuf. */
      if (hlen > p->len) {
        LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
          ("IPv6 options header (hlen %"U16_F") does not fit in first pbuf (len %"U16_F"), IPv6 packet dropped.\n",
              hlen, p->len));
        /* free (drop) packet pbufs */
        pbuf_free(p);
        IP6_FRAG_STATS_INC(ip6_frag.lenerr);
        IP6_FRAG_STATS_INC(ip6_frag.drop);
        goto ip6_input_cleanup;
      }

      /* Offset == 0 and more_fragments == 0? */
      if ((frag_hdr->_fragment_offset &
           PP_HTONS(IP6_FRAG_OFFSET_MASK | IP6_FRAG_MORE_FLAG)) == 0) {
        /* This is a 1-fragment packet, usually a packet that we have
         * already reassembled. Skip this header anc continue. */
        pbuf_header(p, -(s16_t)hlen);
      } else {
#if LWIP_IPV6_REASS

        /* reassemble the packet */
        p = ip6_reass(p);
        /* packet not fully reassembled yet? */
        if (p == NULL) {
          goto ip6_input_cleanup;
        }

        /* Returned p point to IPv6 header.
         * Update all our variables and pointers and continue. */
        ip6hdr = (struct ip6_hdr *)p->payload;
        nexth = IP6H_NEXTH(ip6hdr);
        hlen = ip_data.current_ip_header_tot_len = IP6_HLEN;
        pbuf_header(p, -IP6_HLEN);

#else /* LWIP_IPV6_REASS */
        /* free (drop) packet pbufs */
        LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet with Fragment header dropped (with LWIP_IPV6_REASS==0)\n"));
        pbuf_free(p);
        IP6_STATS_INC(ip6.opterr);
        IP6_STATS_INC(ip6.drop);
        goto ip6_input_cleanup;
#endif /* LWIP_IPV6_REASS */
      }
      break;
    }
    default:
      goto options_done;
      break;
    }
  }
options_done:

  /* p points to IPv6 header again. */
  pbuf_header_force(p, ip_data.current_ip_header_tot_len);

  /* send to upper layers */
  LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: \n"));
  ip6_debug_print(p);
  LWIP_DEBUGF(IP6_DEBUG, ("ip6_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 */
  {
    switch (nexth) {
    case IP6_NEXTH_NONE:
      pbuf_free(p);
      break;
#if LWIP_UDP
    case IP6_NEXTH_UDP:
#if LWIP_UDPLITE
    case IP6_NEXTH_UDPLITE:
#endif /* LWIP_UDPLITE */
      /* Point to payload. */
      pbuf_header(p, -(s16_t)ip_data.current_ip_header_tot_len);
      udp_input(p, inp);
      break;
#endif /* LWIP_UDP */
#if LWIP_TCP
    case IP6_NEXTH_TCP:
      /* Point to payload. */
      pbuf_header(p, -(s16_t)ip_data.current_ip_header_tot_len);
      tcp_input(p, inp);
      break;
#endif /* LWIP_TCP */
#if LWIP_ICMP6
    case IP6_NEXTH_ICMP6:
      /* Point to payload. */
      pbuf_header(p, -(s16_t)ip_data.current_ip_header_tot_len);
      icmp6_input(p, inp);
      break;
#endif /* LWIP_ICMP */
    default:
#if LWIP_ICMP6
      /* send ICMP parameter problem unless it was a multicast or ICMPv6 */
      if ((!ip6_addr_ismulticast(ip6_current_dest_addr())) &&
          (IP6H_NEXTH(ip6hdr) != IP6_NEXTH_ICMP6)) {
        icmp6_param_problem(p, ICMP6_PP_HEADER, ip_data.current_ip_header_tot_len - hlen);
      }
#endif /* LWIP_ICMP */
      LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip6_input: Unsupported transport protocol %"U16_F"\n", IP6H_NEXTH(ip6hdr)));
      pbuf_free(p);
      IP6_STATS_INC(ip6.proterr);
      IP6_STATS_INC(ip6.drop);
      break;
    }
  }

ip6_input_cleanup:
  ip_data.current_netif = NULL;
  ip_data.current_input_netif = NULL;
  ip_data.current_ip6_header = NULL;
  ip_data.current_ip_header_tot_len = 0;
  ip6_addr_set_zero(ip6_current_src_addr());
  ip6_addr_set_zero(ip6_current_dest_addr());

  return ERR_OK;
}