예제 #1
0
/**
 * Outbound TTL/HOPL check.
 */
static int
pxudp_ttl_expired(struct pbuf *p)
{
    int ttl;

    if (ip_current_is_v6()) {
        ttl = IP6H_HOPLIM(ip6_current_header());
    }
    else {
        ttl = IPH_TTL(ip_current_header());
    }

    if (RT_UNLIKELY(ttl <= 1)) {
        int status = pbuf_header(p, ip_current_header_tot_len() + UDP_HLEN);
        if (RT_LIKELY(status == 0)) {
            if (ip_current_is_v6()) {
                icmp6_time_exceeded(p, ICMP6_TE_HL);
            }
            else {
                icmp_time_exceeded(p, ICMP_TE_TTL);
            }
        }
        pbuf_free(p);
        return 1;
    }

    return 0;
}
예제 #2
0
파일: api_msg.c 프로젝트: comrid1987/jb3500
/**
 * Receive callback function for UDP netconns.
 * Posts the packet to conn->recvmbox or deletes it on memory error.
 *
 * @see udp.h (struct udp_pcb.recv) for parameters
 */
static void
recv_udp(void *arg, struct udp_pcb *pcb, struct pbuf *p,
         ip_addr_t *addr, u16_t port)
{
    struct netbuf *buf;
    struct netconn *conn;
    u16_t len;
#if LWIP_SO_RCVBUF
    int recv_avail;
#endif /* LWIP_SO_RCVBUF */

    LWIP_UNUSED_ARG(pcb); /* only used for asserts... */
    LWIP_ASSERT("recv_udp must have a pcb argument", pcb != NULL);
    LWIP_ASSERT("recv_udp must have an argument", arg != NULL);
    conn = (struct netconn *)arg;
    LWIP_ASSERT("recv_udp: recv for wrong pcb!", conn->pcb.udp == pcb);

#if LWIP_SO_RCVBUF
    SYS_ARCH_GET(conn->recv_avail, recv_avail);
    if ((conn == NULL) || !sys_mbox_valid(&conn->recvmbox) ||
            ((recv_avail + (int)(p->tot_len)) > conn->recv_bufsize)) {
#else  /* LWIP_SO_RCVBUF */
    if ((conn == NULL) || !sys_mbox_valid(&conn->recvmbox)) {
#endif /* LWIP_SO_RCVBUF */
        pbuf_free(p);
        return;
    }

    buf = (struct netbuf *)memp_malloc(MEMP_NETBUF);
    if (buf == NULL) {
        pbuf_free(p);
        return;
    } else {
        buf->p = p;
        buf->ptr = p;
        ip_addr_set(&buf->addr, addr);
        buf->port = port;
#if LWIP_NETBUF_RECVINFO
        {
            const struct ip_hdr* iphdr = ip_current_header();
            /* get the UDP header - always in the first pbuf, ensured by udp_input */
            const struct udp_hdr* udphdr = (void*)(((char*)iphdr) + IPH_LEN(iphdr));
#if LWIP_CHECKSUM_ON_COPY
            buf->flags = NETBUF_FLAG_DESTADDR;
#endif /* LWIP_CHECKSUM_ON_COPY */
            ip_addr_set(&buf->toaddr, ip_current_dest_addr());
            buf->toport_chksum = udphdr->dest;
        }
#endif /* LWIP_NETBUF_RECVINFO */
    }

    len = p->tot_len;
    if (sys_mbox_trypost(&conn->recvmbox, buf) != ERR_OK) {
        netbuf_delete(buf);
        return;
    } else {
#if LWIP_SO_RCVBUF
        SYS_ARCH_INC(conn->recv_avail, len);
#endif /* LWIP_SO_RCVBUF */
        /* Register event with callback */
        API_EVENT(conn, NETCONN_EVT_RCVPLUS, len);
    }
}
#endif /* LWIP_UDP */

#if LWIP_TCP
/**
 * Receive callback function for TCP netconns.
 * Posts the packet to conn->recvmbox, but doesn't delete it on errors.
 *
 * @see tcp.h (struct tcp_pcb.recv) for parameters and return value
 */
static err_t
recv_tcp(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err)
{
    struct netconn *conn;
    u16_t len;

    LWIP_UNUSED_ARG(pcb);
    LWIP_ASSERT("recv_tcp must have a pcb argument", pcb != NULL);
    LWIP_ASSERT("recv_tcp must have an argument", arg != NULL);
    conn = (struct netconn *)arg;
    LWIP_ASSERT("recv_tcp: recv for wrong pcb!", conn->pcb.tcp == pcb);

    if (conn == NULL) {
        return ERR_VAL;
    }
    if (!sys_mbox_valid(&conn->recvmbox)) {
        /* recvmbox already deleted */
        if (p != NULL) {
            tcp_recved(pcb, p->tot_len);
            pbuf_free(p);
        }
        return ERR_OK;
    }
    /* Unlike for UDP or RAW pcbs, don't check for available space
       using recv_avail since that could break the connection
       (data is already ACKed) */

    /* don't overwrite fatal errors! */
    NETCONN_SET_SAFE_ERR(conn, err);

    if (p != NULL) {
        len = p->tot_len;
    } else {
        len = 0;
    }

    if (sys_mbox_trypost(&conn->recvmbox, p) != ERR_OK) {
        /* don't deallocate p: it is presented to us later again from tcp_fasttmr! */
        return ERR_MEM;
    } else {
#if LWIP_SO_RCVBUF
        SYS_ARCH_INC(conn->recv_avail, len);
#endif /* LWIP_SO_RCVBUF */
        /* Register event with callback */
        API_EVENT(conn, NETCONN_EVT_RCVPLUS, len);
    }

    return ERR_OK;
}

/**
 * Poll callback function for TCP netconns.
 * Wakes up an application thread that waits for a connection to close
 * or data to be sent. The application thread then takes the
 * appropriate action to go on.
 *
 * Signals the conn->sem.
 * netconn_close waits for conn->sem if closing failed.
 *
 * @see tcp.h (struct tcp_pcb.poll) for parameters and return value
 */
static err_t
poll_tcp(void *arg, struct tcp_pcb *pcb)
{
    struct netconn *conn = (struct netconn *)arg;

    LWIP_UNUSED_ARG(pcb);
    LWIP_ASSERT("conn != NULL", (conn != NULL));

    if (conn->state == NETCONN_WRITE) {
        do_writemore(conn);
    } else if (conn->state == NETCONN_CLOSE) {
        do_close_internal(conn);
    }
    /* @todo: implement connect timeout here? */

    /* Did a nonblocking write fail before? Then check available write-space. */
    if (conn->flags & NETCONN_FLAG_CHECK_WRITESPACE) {
        /* If the queued byte- or pbuf-count drops below the configured low-water limit,
           let select mark this pcb as writable again. */
        if ((conn->pcb.tcp != NULL) && (tcp_sndbuf(conn->pcb.tcp) > TCP_SNDLOWAT) &&
                (tcp_sndqueuelen(conn->pcb.tcp) < TCP_SNDQUEUELOWAT)) {
            conn->flags &= ~NETCONN_FLAG_CHECK_WRITESPACE;
            API_EVENT(conn, NETCONN_EVT_SENDPLUS, 0);
        }
    }

    return ERR_OK;
}

/**
 * Sent callback function for TCP netconns.
 * Signals the conn->sem and calls API_EVENT.
 * netconn_write waits for conn->sem if send buffer is low.
 *
 * @see tcp.h (struct tcp_pcb.sent) for parameters and return value
 */
static err_t
sent_tcp(void *arg, struct tcp_pcb *pcb, u16_t len)
{
    struct netconn *conn = (struct netconn *)arg;

    LWIP_UNUSED_ARG(pcb);
    LWIP_ASSERT("conn != NULL", (conn != NULL));

    if (conn->state == NETCONN_WRITE) {
        do_writemore(conn);
    } else if (conn->state == NETCONN_CLOSE) {
        do_close_internal(conn);
    }

    if (conn) {
        /* If the queued byte- or pbuf-count drops below the configured low-water limit,
           let select mark this pcb as writable again. */
        if ((conn->pcb.tcp != NULL) && (tcp_sndbuf(conn->pcb.tcp) > TCP_SNDLOWAT) &&
                (tcp_sndqueuelen(conn->pcb.tcp) < TCP_SNDQUEUELOWAT)) {
            conn->flags &= ~NETCONN_FLAG_CHECK_WRITESPACE;
            API_EVENT(conn, NETCONN_EVT_SENDPLUS, len);
        }
    }

    return ERR_OK;
}

/**
 * Error callback function for TCP netconns.
 * Signals conn->sem, posts to all conn mboxes and calls API_EVENT.
 * The application thread has then to decide what to do.
 *
 * @see tcp.h (struct tcp_pcb.err) for parameters
 */
static void
err_tcp(void *arg, err_t err)
{
    struct netconn *conn;
    enum netconn_state old_state;
    SYS_ARCH_DECL_PROTECT(lev);

    conn = (struct netconn *)arg;
    LWIP_ASSERT("conn != NULL", (conn != NULL));

    conn->pcb.tcp = NULL;

    /* no check since this is always fatal! */
    SYS_ARCH_PROTECT(lev);
    conn->last_err = err;
    SYS_ARCH_UNPROTECT(lev);

    /* reset conn->state now before waking up other threads */
    old_state = conn->state;
    conn->state = NETCONN_NONE;

    /* Notify the user layer about a connection error. Used to signal
       select. */
    API_EVENT(conn, NETCONN_EVT_ERROR, 0);
    /* Try to release selects pending on 'read' or 'write', too.
       They will get an error if they actually try to read or write. */
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
    API_EVENT(conn, NETCONN_EVT_SENDPLUS, 0);

    /* pass NULL-message to recvmbox to wake up pending recv */
    if (sys_mbox_valid(&conn->recvmbox)) {
        /* use trypost to prevent deadlock */
        sys_mbox_trypost(&conn->recvmbox, NULL);
    }
    /* pass NULL-message to acceptmbox to wake up pending accept */
    if (sys_mbox_valid(&conn->acceptmbox)) {
        /* use trypost to preven deadlock */
        sys_mbox_trypost(&conn->acceptmbox, NULL);
    }

    if ((old_state == NETCONN_WRITE) || (old_state == NETCONN_CLOSE) ||
            (old_state == NETCONN_CONNECT)) {
        /* calling do_writemore/do_close_internal is not necessary
           since the pcb has already been deleted! */
        int was_nonblocking_connect = IN_NONBLOCKING_CONNECT(conn);
        SET_NONBLOCKING_CONNECT(conn, 0);

        if (!was_nonblocking_connect) {
            /* set error return code */
            LWIP_ASSERT("conn->current_msg != NULL", conn->current_msg != NULL);
            conn->current_msg->err = err;
            conn->current_msg = NULL;
            /* wake up the waiting task */
            sys_sem_signal(&conn->op_completed);
        }
    } else {
        LWIP_ASSERT("conn->current_msg == NULL", conn->current_msg == NULL);
    }
}

/**
 * Setup a tcp_pcb with the correct callback function pointers
 * and their arguments.
 *
 * @param conn the TCP netconn to setup
 */
static void
setup_tcp(struct netconn *conn)
{
    struct tcp_pcb *pcb;

    pcb = conn->pcb.tcp;
    tcp_arg(pcb, conn);
    tcp_recv(pcb, recv_tcp);
    tcp_sent(pcb, sent_tcp);
    tcp_poll(pcb, poll_tcp, 4);
    tcp_err(pcb, err_tcp);
}

/**
 * Accept callback function for TCP netconns.
 * Allocates a new netconn and posts that to conn->acceptmbox.
 *
 * @see tcp.h (struct tcp_pcb_listen.accept) for parameters and return value
 */
static err_t
accept_function(void *arg, struct tcp_pcb *newpcb, err_t err)
{
    struct netconn *newconn;
    struct netconn *conn = (struct netconn *)arg;

    LWIP_DEBUGF(API_MSG_DEBUG, ("accept_function: newpcb->tate: %s\n", tcp_debug_state_str(newpcb->state)));

    if (!sys_mbox_valid(&conn->acceptmbox)) {
        LWIP_DEBUGF(API_MSG_DEBUG, ("accept_function: acceptmbox already deleted\n"));
        return ERR_VAL;
    }

    /* We have to set the callback here even though
     * the new socket is unknown. conn->socket is marked as -1. */
    newconn = netconn_alloc(conn->type, conn->callback);
    if (newconn == NULL) {
        return ERR_MEM;
    }
    newconn->pcb.tcp = newpcb;
    setup_tcp(newconn);
    /* no protection: when creating the pcb, the netconn is not yet known
       to the application thread */
    newconn->last_err = err;

    if (sys_mbox_trypost(&conn->acceptmbox, newconn) != ERR_OK) {
        /* When returning != ERR_OK, the pcb is aborted in tcp_process(),
           so do nothing here! */
        /* remove all references to this netconn from the pcb */
        struct tcp_pcb* pcb = newconn->pcb.tcp;
        tcp_arg(pcb, NULL);
        tcp_recv(pcb, NULL);
        tcp_sent(pcb, NULL);
        tcp_poll(pcb, NULL, 4);
        tcp_err(pcb, NULL);
        /* remove reference from to the pcb from this netconn */
        newconn->pcb.tcp = NULL;
        /* no need to drain since we know the recvmbox is empty. */
        sys_mbox_free(&newconn->recvmbox);
        sys_mbox_set_invalid(&newconn->recvmbox);
        netconn_free(newconn);
        return ERR_MEM;
    } else {
        /* Register event with callback */
        API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
    }

    return ERR_OK;
}
#endif /* LWIP_TCP */

/**
 * Create a new pcb of a specific type.
 * Called from do_newconn().
 *
 * @param msg the api_msg_msg describing the connection type
 * @return msg->conn->err, but the return value is currently ignored
 */
static void
pcb_new(struct api_msg_msg *msg)
{
    LWIP_ASSERT("pcb_new: pcb already allocated", msg->conn->pcb.tcp == NULL);

    /* Allocate a PCB for this connection */
    switch(NETCONNTYPE_GROUP(msg->conn->type)) {
#if LWIP_RAW
    case NETCONN_RAW:
        msg->conn->pcb.raw = raw_new(msg->msg.n.proto);
        if(msg->conn->pcb.raw == NULL) {
            msg->err = ERR_MEM;
            break;
        }
        raw_recv(msg->conn->pcb.raw, recv_raw, msg->conn);
        break;
#endif /* LWIP_RAW */
#if LWIP_UDP
    case NETCONN_UDP:
        msg->conn->pcb.udp = udp_new();
        if(msg->conn->pcb.udp == NULL) {
            msg->err = ERR_MEM;
            break;
        }
#if LWIP_UDPLITE
        if (msg->conn->type==NETCONN_UDPLITE) {
            udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_UDPLITE);
        }
#endif /* LWIP_UDPLITE */
        if (msg->conn->type==NETCONN_UDPNOCHKSUM) {
            udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_NOCHKSUM);
        }
        udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
        break;
#endif /* LWIP_UDP */
#if LWIP_TCP
    case NETCONN_TCP:
        msg->conn->pcb.tcp = tcp_new();
        if(msg->conn->pcb.tcp == NULL) {
            msg->err = ERR_MEM;
            break;
        }
        setup_tcp(msg->conn);
        break;
#endif /* LWIP_TCP */
    default:
        /* Unsupported netconn type, e.g. protocol disabled */
        msg->err = ERR_VAL;
        break;
    }
}
예제 #3
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 acceptd? */
      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;
      /* 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 = (struct ip_hdr *)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. */
    iecho = (struct icmp_echo_hdr *)p->payload;
    ip_addr_copy(iphdr->src, *ip_current_dest_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 curren 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 */
}
예제 #4
0
static void
pxudp_pcb_forward_outbound(struct pxudp *pxudp, struct pbuf *p,
                           ip_addr_t *addr, u16_t port)
{
    int status;

    LWIP_UNUSED_ARG(addr);
    LWIP_UNUSED_ARG(port);

    if (!pxudp->is_mapped && pxudp_ttl_expired(p)) {
        return;
    }

    if (!ip_current_is_v6()) { /* IPv4 */
        const struct ip_hdr *iph = ip_current_header();
        int ttl, tos, df;

        /*
         * Different OSes have different socket options for DF.
         * Unlike pxping.c, we can't use IP_HDRINCL here as it's only
         * valid for SOCK_RAW.
         */
#     define USE_DF_OPTION(_Optname)                    \
        const int dfopt = _Optname;                     \
        const char * const dfoptname = #_Optname;
#if   defined(IP_MTU_DISCOVER)  /* Linux */
        USE_DF_OPTION(IP_MTU_DISCOVER);
#elif defined(IP_DONTFRAG)      /* Solaris 11+, FreeBSD */
        USE_DF_OPTION(IP_DONTFRAG);
#elif defined(IP_DONTFRAGMENT)  /* Windows */
        USE_DF_OPTION(IP_DONTFRAGMENT);
#else
        USE_DF_OPTION(0);
#endif

        ttl = IPH_TTL(iph);
        if (!pxudp->is_mapped) {
            LWIP_ASSERT1(ttl > 1);
            --ttl;
        }

        if (ttl != pxudp->ttl) {
            status = setsockopt(pxudp->sock, IPPROTO_IP, IP_TTL,
                                (char *)&ttl, sizeof(ttl));
            if (RT_LIKELY(status == 0)) {
                pxudp->ttl = ttl;
            }
            else {
                DPRINTF(("IP_TTL: %R[sockerr]\n", SOCKERRNO()));
            }
        }

        tos = IPH_TOS(iph);
        if (tos != pxudp->tos) {
            status = setsockopt(pxudp->sock, IPPROTO_IP, IP_TOS,
                                (char *)&tos, sizeof(tos));
            if (RT_LIKELY(status == 0)) {
                pxudp->tos = tos;
            }
            else {
                DPRINTF(("IP_TOS: %R[sockerr]\n", SOCKERRNO()));
            }
        }

        if (dfopt) {
            df = (IPH_OFFSET(iph) & PP_HTONS(IP_DF)) != 0;
#if defined(IP_MTU_DISCOVER)
            df = df ? IP_PMTUDISC_DO : IP_PMTUDISC_DONT;
#endif
            if (df != pxudp->df) {
                status = setsockopt(pxudp->sock, IPPROTO_IP, dfopt,
                                    (char *)&df, sizeof(df));
                if (RT_LIKELY(status == 0)) {
                    pxudp->df = df;
                }
                else {
                    DPRINTF(("%s: %R[sockerr]\n", dfoptname, SOCKERRNO()));
                }
            }
        }
    }
    else { /* IPv6 */
        const struct ip6_hdr *iph = ip6_current_header();
        int ttl;

        ttl = IP6H_HOPLIM(iph);
        if (!pxudp->is_mapped) {
            LWIP_ASSERT1(ttl > 1);
            --ttl;
        }

        if (ttl != pxudp->ttl) {
            status = setsockopt(pxudp->sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
                                (char *)&ttl, sizeof(ttl));
            if (RT_LIKELY(status == 0)) {
                pxudp->ttl = ttl;
            }
            else {
                DPRINTF(("IPV6_UNICAST_HOPS: %R[sockerr]\n", SOCKERRNO()));
            }
        }
    }

    if (pxudp->pcb->local_port == 53) {
        ++pxudp->count;
    }

    proxy_sendto(pxudp->sock, p, NULL, 0);
    pbuf_free(p);
}
예제 #5
0
파일: pxping_win.c 프로젝트: bayasist/vbox
/**
 * 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);
}
예제 #6
0
파일: igmp.c 프로젝트: Ga-vin/libsylixos
/**
 * Called from ip_input() if a new IGMP packet is received.
 *
 * @param p received igmp packet, p->payload pointing to the igmp 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, const ip_addr_t *dest)
{
  struct igmp_msg*   igmp;
  struct igmp_group* group;
  struct igmp_group* groupref;

  IGMP_STATS_INC(igmp.recv);

  /* Note that the length CAN be greater than 8 but only 8 are used - All are included in the checksum */    
  if (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, &(ip_current_header()->src));
  LWIP_DEBUGF(IGMP_DEBUG, (" to address "));
  ip_addr_debug_print(IGMP_DEBUG, &(ip_current_header()->dest));
  LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", 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 destination IP address of incoming packet */
  
  /* If group can be found or create... */
  if (!group) {
    pbuf_free(p);
    IGMP_STATS_INC(igmp.drop);
    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)) && ip_addr_isany(&igmp->igmp_group_address)) {
       /* 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.rx_v1);
         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;
       } else {
         IGMP_STATS_INC(igmp.rx_general);
       }

       groupref = igmp_group_list;
       while (groupref) {
         /* Do not send messages on the all systems group address! */
         if ((groupref->netif == 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 (!ip_addr_isany(&igmp->igmp_group_address)) {
         LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_MEMB_QUERY to a specific group "));
         ip_addr_debug_print(IGMP_DEBUG, &igmp->igmp_group_address);
         if (ip_addr_cmp(dest, &allsystems)) {
           ip_addr_t groupaddr;
           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-look for the group since we used dest last time */
           ip_addr_copy(groupaddr, igmp->igmp_group_address);
           group = igmp_lookfor_group(inp, &groupaddr);
         } 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.rx_group);
           igmp_delaying_member(group, igmp->igmp_maxresp);
         } else {
           IGMP_STATS_INC(igmp.drop);
         }
       } else {
         IGMP_STATS_INC(igmp.proterr);
       }
     }
     break;
   }
   case IGMP_V2_MEMB_REPORT: {
     LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_V2_MEMB_REPORT\n"));
     IGMP_STATS_INC(igmp.rx_report);
     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 %d in state %d on group %p on if %p\n",
       igmp->igmp_msgtype, group->group_state, &group, group->netif));
     IGMP_STATS_INC(igmp.proterr);
     break;
   }
  }

  pbuf_free(p);
  return;
}
예제 #7
-1
/**
 * Receive callback function for RAW netconns.
 * Doesn't 'eat' the packet, only references it and sends it to
 * conn->recvmbox
 *
 * @see raw.h (struct raw_pcb.recv) for parameters and return value
 */
static u8_t
recv_raw(void *arg, struct raw_pcb *pcb, struct pbuf *p,
    struct ip_addr *addr)
{
  struct pbuf *q;
  struct netbuf *buf;
  struct netconn *conn;
#if LWIP_SO_RCVBUF
  int recv_avail;
#endif /* LWIP_SO_RCVBUF */

  LWIP_UNUSED_ARG(addr);
  conn = arg;

#if LWIP_SO_RCVBUF
  SYS_ARCH_GET(conn->recv_avail, recv_avail);
  if ((conn != NULL) && (conn->recvmbox != SYS_MBOX_NULL) &&
      ((recv_avail + (int)(p->tot_len)) <= conn->recv_bufsize)) {
#else  /* LWIP_SO_RCVBUF */
  if ((conn != NULL) && (conn->recvmbox != SYS_MBOX_NULL)) {
#endif /* LWIP_SO_RCVBUF */
    /* copy the whole packet into new pbufs */
    q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
    if(q != NULL) {
      if (pbuf_copy(q, p) != ERR_OK) {
        pbuf_free(q);
        q = NULL;
      }
    }

    if(q != NULL) {
      buf = memp_malloc(MEMP_NETBUF);
      if (buf == NULL) {
        pbuf_free(q);
        return 0;
      }

      buf->p = q;
      buf->ptr = q;
      buf->addr = &(((struct ip_hdr*)(q->payload))->src);
      buf->port = pcb->protocol;

      if (sys_mbox_trypost(conn->recvmbox, buf) != ERR_OK) {
        netbuf_delete(buf);
        return 0;
      } else {
        SYS_ARCH_INC(conn->recv_avail, q->tot_len);
        /* Register event with callback */
        API_EVENT(conn, NETCONN_EVT_RCVPLUS, q->tot_len);
      }
    }
  }

  return 0; /* do not eat the packet */
}
#endif /* LWIP_RAW*/

#if LWIP_UDP
/**
 * Receive callback function for UDP netconns.
 * Posts the packet to conn->recvmbox or deletes it on memory error.
 *
 * @see udp.h (struct udp_pcb.recv) for parameters
 */
static void
recv_udp(void *arg, struct udp_pcb *pcb, struct pbuf *p,
   struct ip_addr *addr, u16_t port)
{
  struct netbuf *buf;
  struct netconn *conn;
#if LWIP_SO_RCVBUF
  int recv_avail;
#endif /* LWIP_SO_RCVBUF */

  LWIP_UNUSED_ARG(pcb); /* only used for asserts... */
  LWIP_ASSERT("recv_udp must have a pcb argument", pcb != NULL);
  LWIP_ASSERT("recv_udp must have an argument", arg != NULL);
  conn = arg;
  LWIP_ASSERT("recv_udp: recv for wrong pcb!", conn->pcb.udp == pcb);

#if LWIP_SO_RCVBUF
  SYS_ARCH_GET(conn->recv_avail, recv_avail);
  if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL) ||
      ((recv_avail + (int)(p->tot_len)) > conn->recv_bufsize)) {
#else  /* LWIP_SO_RCVBUF */
  if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL)) {
#endif /* LWIP_SO_RCVBUF */
    pbuf_free(p);
    return;
  }

  buf = memp_malloc(MEMP_NETBUF);
  if (buf == NULL) {
    pbuf_free(p);
    return;
  } else {
    buf->p = p;
    buf->ptr = p;
    buf->addr = addr;
    buf->port = port;
#if LWIP_NETBUF_RECVINFO
    {
      const struct ip_hdr* iphdr = ip_current_header();
      /* get the UDP header - always in the first pbuf, ensured by udp_input */
      const struct udp_hdr* udphdr = (void*)(((char*)iphdr) + IPH_LEN(iphdr));
      buf->toaddr = (struct ip_addr*)&iphdr->dest;
      buf->toport = udphdr->dest;
    }
#endif /* LWIP_NETBUF_RECVINFO */
  }

  if (sys_mbox_trypost(conn->recvmbox, buf) != ERR_OK) {
    netbuf_delete(buf);
    return;
  } else {
    SYS_ARCH_INC(conn->recv_avail, p->tot_len);
    /* Register event with callback */
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, p->tot_len);
  }
}
#endif /* LWIP_UDP */

#if LWIP_TCP
/**
 * Receive callback function for TCP netconns.
 * Posts the packet to conn->recvmbox, but doesn't delete it on errors.
 *
 * @see tcp.h (struct tcp_pcb.recv) for parameters and return value
 */
static err_t
recv_tcp(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err)
{
  struct netconn *conn;
  u16_t len;

  LWIP_UNUSED_ARG(pcb);
  LWIP_ASSERT("recv_tcp must have a pcb argument", pcb != NULL);
  LWIP_ASSERT("recv_tcp must have an argument", arg != NULL);
  conn = arg;
  LWIP_ASSERT("recv_tcp: recv for wrong pcb!", conn->pcb.tcp == pcb);

  if ((conn == NULL) || (conn->recvmbox == SYS_MBOX_NULL)) {
    return ERR_VAL;
  }

  conn->err = err;
  if (p != NULL) {
    len = p->tot_len;
    SYS_ARCH_INC(conn->recv_avail, len);
  } else {
    len = 0;
  }

  if (sys_mbox_trypost(conn->recvmbox, p) != ERR_OK) {
    return ERR_MEM;
  } else {
    /* Register event with callback */
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, len);
  }

  return ERR_OK;
}

/**
 * Poll callback function for TCP netconns.
 * Wakes up an application thread that waits for a connection to close
 * or data to be sent. The application thread then takes the
 * appropriate action to go on.
 *
 * Signals the conn->sem.
 * netconn_close waits for conn->sem if closing failed.
 *
 * @see tcp.h (struct tcp_pcb.poll) for parameters and return value
 */
static err_t
poll_tcp(void *arg, struct tcp_pcb *pcb)
{
  struct netconn *conn = arg;

  LWIP_UNUSED_ARG(pcb);
  LWIP_ASSERT("conn != NULL", (conn != NULL));

  if (conn->state == NETCONN_WRITE) {
    do_writemore(conn);
  } else if (conn->state == NETCONN_CLOSE) {
    do_close_internal(conn);
  }

  return ERR_OK;
}

/**
 * Sent callback function for TCP netconns.
 * Signals the conn->sem and calls API_EVENT.
 * netconn_write waits for conn->sem if send buffer is low.
 *
 * @see tcp.h (struct tcp_pcb.sent) for parameters and return value
 */
static err_t
sent_tcp(void *arg, struct tcp_pcb *pcb, u16_t len)
{
  struct netconn *conn = arg;

  LWIP_UNUSED_ARG(pcb);
  LWIP_ASSERT("conn != NULL", (conn != NULL));

  if (conn->state == NETCONN_WRITE) {
    LWIP_ASSERT("conn->pcb.tcp != NULL", conn->pcb.tcp != NULL);
    do_writemore(conn);
  } else if (conn->state == NETCONN_CLOSE) {
    do_close_internal(conn);
  }

  if (conn) {
    if ((conn->pcb.tcp != NULL) && (tcp_sndbuf(conn->pcb.tcp) > TCP_SNDLOWAT)) {
      API_EVENT(conn, NETCONN_EVT_SENDPLUS, len);
    }
  }
  
  return ERR_OK;
}

/**
 * Error callback function for TCP netconns.
 * Signals conn->sem, posts to all conn mboxes and calls API_EVENT.
 * The application thread has then to decide what to do.
 *
 * @see tcp.h (struct tcp_pcb.err) for parameters
 */
static void
err_tcp(void *arg, err_t err)
{
  struct netconn *conn;

  conn = arg;
  LWIP_ASSERT("conn != NULL", (conn != NULL));

  conn->pcb.tcp = NULL;

  conn->err = err;
  if (conn->recvmbox != SYS_MBOX_NULL) {
    /* Register event with callback */
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
    sys_mbox_post(conn->recvmbox, NULL);
  }
  if (conn->op_completed != SYS_SEM_NULL && conn->state == NETCONN_CONNECT) {
    conn->state = NETCONN_NONE;
    sys_sem_signal(conn->op_completed);
  }
  if (conn->acceptmbox != SYS_MBOX_NULL) {
    /* Register event with callback */
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
    sys_mbox_post(conn->acceptmbox, NULL);
  }
  if ((conn->state == NETCONN_WRITE) || (conn->state == NETCONN_CLOSE)) {
    /* calling do_writemore/do_close_internal is not necessary
       since the pcb has already been deleted! */
    conn->state = NETCONN_NONE;
    /* wake up the waiting task */
    sys_sem_signal(conn->op_completed);
  }
}

/**
 * Setup a tcp_pcb with the correct callback function pointers
 * and their arguments.
 *
 * @param conn the TCP netconn to setup
 */
static void
setup_tcp(struct netconn *conn)
{
  struct tcp_pcb *pcb;

  pcb = conn->pcb.tcp;
  tcp_arg(pcb, conn);
  tcp_recv(pcb, recv_tcp);
  tcp_sent(pcb, sent_tcp);
  tcp_poll(pcb, poll_tcp, 4);
  tcp_err(pcb, err_tcp);
}

/**
 * Accept callback function for TCP netconns.
 * Allocates a new netconn and posts that to conn->acceptmbox.
 *
 * @see tcp.h (struct tcp_pcb_listen.accept) for parameters and return value
 */
static err_t
accept_function(void *arg, struct tcp_pcb *newpcb, err_t err)
{
  struct netconn *newconn;
  struct netconn *conn;

#if API_MSG_DEBUG
#if TCP_DEBUG
  tcp_debug_print_state(newpcb->state);
#endif /* TCP_DEBUG */
#endif /* API_MSG_DEBUG */
  conn = (struct netconn *)arg;

  LWIP_ERROR("accept_function: invalid conn->acceptmbox",
             conn->acceptmbox != SYS_MBOX_NULL, return ERR_VAL;);

  /* We have to set the callback here even though
   * the new socket is unknown. conn->socket is marked as -1. */
  newconn = netconn_alloc(conn->type, conn->callback);
  if (newconn == NULL) {
    return ERR_MEM;
  }
  newconn->pcb.tcp = newpcb;
  setup_tcp(newconn);
  newconn->err = err;

  if (sys_mbox_trypost(conn->acceptmbox, newconn) != ERR_OK) {
    /* When returning != ERR_OK, the connection is aborted in tcp_process(),
       so do nothing here! */
    newconn->pcb.tcp = NULL;
    netconn_free(newconn);
    return ERR_MEM;
  } else {
    /* Register event with callback */
    API_EVENT(conn, NETCONN_EVT_RCVPLUS, 0);
  }

  return ERR_OK;
}
#endif /* LWIP_TCP */

/**
 * Create a new pcb of a specific type.
 * Called from do_newconn().
 *
 * @param msg the api_msg_msg describing the connection type
 * @return msg->conn->err, but the return value is currently ignored
 */
static err_t
pcb_new(struct api_msg_msg *msg)
{
   msg->conn->err = ERR_OK;

   LWIP_ASSERT("pcb_new: pcb already allocated", msg->conn->pcb.tcp == NULL);

   /* Allocate a PCB for this connection */
   switch(NETCONNTYPE_GROUP(msg->conn->type)) {
#if LWIP_RAW
   case NETCONN_RAW:
     msg->conn->pcb.raw = raw_new(msg->msg.n.proto);
     if(msg->conn->pcb.raw == NULL) {
       msg->conn->err = ERR_MEM;
       break;
     }
     raw_recv(msg->conn->pcb.raw, recv_raw, msg->conn);
     break;
#endif /* LWIP_RAW */
#if LWIP_UDP
   case NETCONN_UDP:
     msg->conn->pcb.udp = udp_new();
     if(msg->conn->pcb.udp == NULL) {
       msg->conn->err = ERR_MEM;
       break;
     }
#if LWIP_UDPLITE
     if (msg->conn->type==NETCONN_UDPLITE) {
       udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_UDPLITE);
     }
#endif /* LWIP_UDPLITE */
     if (msg->conn->type==NETCONN_UDPNOCHKSUM) {
       udp_setflags(msg->conn->pcb.udp, UDP_FLAGS_NOCHKSUM);
     }
     udp_recv(msg->conn->pcb.udp, recv_udp, msg->conn);
     break;
#endif /* LWIP_UDP */
#if LWIP_TCP
   case NETCONN_TCP:
     msg->conn->pcb.tcp = tcp_new();
     if(msg->conn->pcb.tcp == NULL) {
       msg->conn->err = ERR_MEM;
       break;
     }
     setup_tcp(msg->conn);
     break;
#endif /* LWIP_TCP */
   default:
     /* Unsupported netconn type, e.g. protocol disabled */
     msg->conn->err = ERR_VAL;
     break;
   }

  return msg->conn->err;
}