Exemple #1
0
/**
 * Sends an IPv6 packet on a network interface. This function constructs
 * the IPv6 header. If the source IPv6 address is NULL, the IPv6 "ANY" address is
 * used as source (usually during network startup). If the source IPv6 address it
 * IP6_ADDR_ANY, the most appropriate IPv6 address of the outgoing network
 * interface is filled in as source address. If the destination IPv6 address is
 * IP_HDRINCL, p is assumed to already include an IPv6 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
            IPv6 header and p->payload points to that IPv6 header)
 * @param src the source IPv6 address to send from (if src == IP6_ADDR_ANY, an
 *         IP address of the netif is selected and used as source address.
 *         if src == NULL, IP6_ADDR_ANY is used as source)
 * @param dest the destination IPv6 address to send the packet to
 * @param hl the Hop Limit value to be set in the IPv6 header
 * @param tc the Traffic Class value to be set in the IPv6 header
 * @param nexth the Next Header to be set in the IPv6 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 IPv6/LINK headers
 *         returns errors returned by netif->output
 */
err_t
ip6_output_if(struct pbuf *p, const ip6_addr_t *src, const ip6_addr_t *dest,
             u8_t hl, u8_t tc,
             u8_t nexth, struct netif *netif)
{
  const ip6_addr_t *src_used = src;
  if (dest != IP_HDRINCL) {
    if (src != NULL && ip6_addr_isany(src)) {
      src = ip6_select_source_address(netif, dest);
      if ((src == NULL) || ip6_addr_isany(src)) {
        /* No appropriate source address was found for this packet. */
        LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip6_output: No suitable source address for packet.\n"));
        IP6_STATS_INC(ip6.rterr);
        return ERR_RTE;
      }
    }
  }
  return ip6_output_if_src(p, src_used, dest, hl, tc, nexth, netif);
}
Exemple #2
0
err_t ip6_output_if(struct pbuf *p, struct ip6_addr *src, struct ip6_addr *dest, u8_t ttl, u8_t proto, struct netif *netif) {
    struct ip6_hdr *iphdr;

    PERF_START;

    LWIP_DEBUGF(IP_DEBUG, ("len %"U16_F" tot_len %"U16_F"\n", p->len, p->tot_len));
    if (pbuf_header(p, IP6_HLEN)) {
        LWIP_DEBUGF(IP_DEBUG, ("ip_output: not enough room for IP header in pbuf\n"));IP_STATS_INC(ip.err);

        return ERR_BUF;
    }
    LWIP_DEBUGF(IP_DEBUG, ("len %"U16_F" tot_len %"U16_F"\n", p->len, p->tot_len));

    iphdr = p->payload;

    if (dest != IP_HDRINCL) {
        LWIP_DEBUGF(IP_DEBUG, ("!IP_HDRLINCL\n"));
        iphdr->hoplim = ttl;
        iphdr->nexthdr = proto;
        iphdr->len = htons(p->tot_len - IP6_HLEN);
        ip6_addr_set(&(iphdr->dest), dest);

        iphdr->v = 6;

        if (ip6_addr_isany(src)) {
            ip6_addr_set(&(iphdr->src), &(netif->ip6_addr));
        } else {
            ip6_addr_set(&(iphdr->src), src);
        }
    } else {
        dest = &(iphdr->dest);
    }

    IP_STATS_INC(ip.xmit);

    LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c (len %"U16_F")\n", netif->name[0], netif->name[1], p->tot_len));
#if IP_DEBUG
    ip6_debug_print(p);
#endif /* IP_DEBUG */

    PERF_STOP("ip_output_if");
    if (netif->ip6_output != 0) {
        return (netif->ip6_output(netif, p, dest));
    } else {
        return (ERR_RTE);
    }
}
/**
 * Finds the appropriate network interface for a given IPv6 address. It tries to select
 * a netif following a sequence of heuristics:
 * 1) if there is only 1 netif, return it
 * 2) if the destination is a link-local address, try to match the src address to a netif.
 *    this is a tricky case because with multiple netifs, link-local addresses only have
 *    meaning within a particular subnet/link.
 * 3) tries to match the destination subnet to a configured address
 * 4) tries to find a router
 * 5) tries to match the source address to the netif
 * 6) returns the default netif, if configured
 *
 * @param src the source IPv6 address, if known
 * @param dest the destination IPv6 address for which to find the route
 * @return the netif on which to send to reach dest
 */
struct netif *
ip6_route(const ip6_addr_t *src, const ip6_addr_t *dest)
{
  struct netif *netif;
  s8_t i;

#ifdef LWIP_HOOK_IP6_ROUTE
  netif = LWIP_HOOK_IP6_ROUTE(src, dest);
  if (netif != NULL) {
    return netif;
  }
#endif

  /* If single netif configuration, fast return. */
  if ((netif_list != NULL) && (netif_list->next == NULL)) {
    if (!netif_is_up(netif_list) || !netif_is_link_up(netif_list)) {
      return NULL;
    }
    return netif_list;
  }

  /* Special processing for link-local addresses. */
  if (ip6_addr_islinklocal(dest)) {
    if (ip6_addr_isany(src)) {
      /* Use default netif, if Up. */
      if (!netif_is_up(netif_default) || !netif_is_link_up(netif_default)) {
        return NULL;
      }
      return netif_default;
    }

    /* Try to find the netif for the source address, checking that link is up. */
    for (netif = netif_list; netif != NULL; netif = netif->next) {
      if (!netif_is_up(netif) || !netif_is_link_up(netif)) {
        continue;
      }
      for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
        if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
            ip6_addr_cmp(src, netif_ip6_addr(netif, i))) {
          return netif;
        }
      }
    }

    /* netif not found, use default netif, if up */
    if (!netif_is_up(netif_default) || !netif_is_link_up(netif_default)) {
      return NULL;
    }
    return netif_default;
  }

  /* See if the destination subnet matches a configured address. */
  for (netif = netif_list; netif != NULL; netif = netif->next) {
    if (!netif_is_up(netif) || !netif_is_link_up(netif)) {
      continue;
    }
    for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
      if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
          ip6_addr_netcmp(dest, netif_ip6_addr(netif, i))) {
        return netif;
      }
    }
  }

  /* Get the netif for a suitable router. */
  i = nd6_select_router(dest, NULL);
  if (i >= 0) {
    if (default_router_list[i].neighbor_entry != NULL) {
      if (default_router_list[i].neighbor_entry->netif != NULL) {
        if (netif_is_up(default_router_list[i].neighbor_entry->netif) && netif_is_link_up(default_router_list[i].neighbor_entry->netif)) {
          return default_router_list[i].neighbor_entry->netif;
        }
      }
    }
  }

  /* try with the netif that matches the source address. */
  if (!ip6_addr_isany(src)) {
    for (netif = netif_list; netif != NULL; netif = netif->next) {
      if (!netif_is_up(netif) || !netif_is_link_up(netif)) {
        continue;
      }
      for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
        if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
            ip6_addr_cmp(src, netif_ip6_addr(netif, i))) {
          return netif;
        }
      }
    }
  }

#if LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF
  /* loopif is disabled, loopback traffic is passed through any netif */
  if (ip6_addr_isloopback(dest)) {
    /* don't check for link on loopback traffic */
    if (netif_is_up(netif_default)) {
      return netif_default;
    }
    /* default netif is not up, just use any netif for loopback traffic */
    for (netif = netif_list; netif != NULL; netif = netif->next) {
      if (netif_is_up(netif)) {
        return netif;
      }
    }
    return NULL;
  }
#endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */

  /* no matching netif found, use default netif, if up */
  if (!netif_is_up(netif_default) || !netif_is_link_up(netif_default)) {
    return NULL;
  }
  return netif_default;
}
/**
 * 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;
}
Exemple #5
0
/**
 * Finds the appropriate network interface for a given IPv6 address. It tries to select
 * a netif following a sequence of heuristics:
 * 1) if there is only 1 netif, return it
 * 2) if the destination is a link-local address, try to match the src address to a netif.
 *    this is a tricky case because with multiple netifs, link-local addresses only have
 *    meaning within a particular subnet/link.
 * 3) tries to match the destination subnet to a configured address
 * 4) tries to find a router
 * 5) tries to match the source address to the netif
 * 6) returns the default netif, if configured
 *
 * @param src the source IPv6 address, if known
 * @param dest the destination IPv6 address for which to find the route
 * @return the netif on which to send to reach dest
 */
struct netif *
ip6_route(struct ip6_addr *src, struct ip6_addr *dest)
{
    struct netif *netif;
    s8_t i;

    /* If single netif configuration, fast return. */
    if ((netif_list != NULL) && (netif_list->next == NULL)) {
        return netif_list;
    }

    /* Special processing for link-local addresses. */
    if (ip6_addr_islinklocal(dest)) {
        if (ip6_addr_isany(src)) {
            /* Use default netif. */
            return netif_default;
        }

        /* Try to find the netif for the source address. */
        for(netif = netif_list; netif != NULL; netif = netif->next) {
            for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
                if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
                        ip6_addr_cmp(src, netif_ip6_addr(netif, i))) {
                    return netif;
                }
            }
        }

        /* netif not found, use default netif */
        return netif_default;
    }

    /* See if the destination subnet matches a configured address. */
    for(netif = netif_list; netif != NULL; netif = netif->next) {
        for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
            if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
                    ip6_addr_netcmp(dest, netif_ip6_addr(netif, i))) {
                return netif;
            }
        }
    }

    /* Get the netif for a suitable router. */
    i = nd6_select_router(dest, NULL);
    if (i >= 0) {
        if (default_router_list[i].neighbor_entry != NULL) {
            if (default_router_list[i].neighbor_entry->netif != NULL) {
                return default_router_list[i].neighbor_entry->netif;
            }
        }
    }

    /* try with the netif that matches the source address. */
    if (!ip6_addr_isany(src)) {
        for(netif = netif_list; netif != NULL; netif = netif->next) {
            for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
                if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
                        ip6_addr_cmp(src, netif_ip6_addr(netif, i))) {
                    return netif;
                }
            }
        }
    }

    /* no matching netif found, use default netif */
    return netif_default;
}
Exemple #6
0
/**
 * Sends an IPv6 packet on a network interface. This function constructs
 * the IPv6 header. If the source IPv6 address is NULL, the IPv6 "ANY" address is
 * used as source (usually during network startup). If the source IPv6 address it
 * IP6_ADDR_ANY, the most appropriate IPv6 address of the outgoing network
 * interface is filled in as source address. If the destination IPv6 address is
 * IP_HDRINCL, p is assumed to already include an IPv6 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
            IPv6 header and p->payload points to that IPv6 header)
 * @param src the source IPv6 address to send from (if src == IP6_ADDR_ANY, an
 *         IP address of the netif is selected and used as source address.
 *         if src == NULL, IP6_ADDR_ANY is used as source)
 * @param dest the destination IPv6 address to send the packet to
 * @param hl the Hop Limit value to be set in the IPv6 header
 * @param tc the Traffic Class value to be set in the IPv6 header
 * @param nexth the Next Header to be set in the IPv6 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 IPv6/LINK headers
 *         returns errors returned by netif->output
 */
err_t
ip6_output_if(struct pbuf *p, ip6_addr_t *src, ip6_addr_t *dest,
              u8_t hl, u8_t tc,
              u8_t nexth, struct netif *netif)
{
    struct ip6_hdr *ip6hdr;
    ip6_addr_t dest_addr;

    /* pbufs passed to IP must have a ref-count of 1 as their payload pointer
       gets altered as the packet is passed down the stack */
    LWIP_ASSERT("p->ref == 1", p->ref == 1);

    /* Should the IPv6 header be generated or is it already included in p? */
    if (dest != IP_HDRINCL) {
        /* generate IPv6 header */
        if (pbuf_header(p, IP6_HLEN)) {
            LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip6_output: not enough room for IPv6 header in pbuf\n"));
            IP6_STATS_INC(ip6.err);
            return ERR_BUF;
        }

        ip6hdr = (struct ip6_hdr *)p->payload;
        LWIP_ASSERT("check that first pbuf can hold struct ip6_hdr",
                    (p->len >= sizeof(struct ip6_hdr)));

        IP6H_HOPLIM_SET(ip6hdr, hl);
        IP6H_NEXTH_SET(ip6hdr, nexth);

        /* dest cannot be NULL here */
        ip6_addr_copy(ip6hdr->dest, *dest);

        IP6H_VTCFL_SET(ip6hdr, 6, tc, 0);
        IP6H_PLEN_SET(ip6hdr, p->tot_len - IP6_HLEN);

        if (src == NULL) {
            src = IP6_ADDR_ANY;
        }
        else if (ip6_addr_isany(src)) {
            src = ip6_select_source_address(netif, dest);
            if ((src == NULL) || ip6_addr_isany(src)) {
                /* No appropriate source address was found for this packet. */
                LWIP_DEBUGF(IP6_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip6_output: No suitable source address for packet.\n"));
                IP6_STATS_INC(ip6.rterr);
                return ERR_RTE;
            }
        }
        /* src cannot be NULL here */
        ip6_addr_copy(ip6hdr->src, *src);

    } else {
        /* IP header already included in p */
        ip6hdr = (struct ip6_hdr *)p->payload;
        ip6_addr_copy(dest_addr, ip6hdr->dest);
        dest = &dest_addr;
    }

    IP6_STATS_INC(ip6.xmit);

    LWIP_DEBUGF(IP6_DEBUG, ("ip6_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
    ip6_debug_print(p);

#if ENABLE_LOOPBACK
    /* TODO implement loopback for v6
    if (ip6_addr_cmp(dest, netif_ip6_addr(0))) {
      return netif_loop_output(netif, p, dest);
    }*/
#endif /* ENABLE_LOOPBACK */
#if LWIP_IPV6_FRAG
    /* don't fragment if interface has mtu set to 0 [loopif] */
    if (netif->mtu && (p->tot_len > nd6_get_destination_mtu(dest, netif))) {
        return ip6_frag(p, netif, dest);
    }
#endif /* LWIP_IPV6_FRAG */

    LWIP_DEBUGF(IP6_DEBUG, ("netif->output_ip6()"));
    return netif->output_ip6(netif, p, dest);
}
Exemple #7
0
/**
 * Process an input MLD message. Called by icmp6_input.
 *
 * @param p the mld packet, p->payload pointing to the icmpv6 header
 * @param inp the netif on which this packet was received
 */
void
mld6_input(struct pbuf *p, struct netif *inp)
{
  struct mld_header * mld_hdr;
  struct mld_group* group;

  MLD6_STATS_INC(mld6.recv);

  /* Check that mld header fits in packet. */
  if (p->len < sizeof(struct mld_header)) {
    // TODO debug message
    pbuf_free(p);
    MLD6_STATS_INC(mld6.lenerr);
    MLD6_STATS_INC(mld6.drop);
    return;
  }

  mld_hdr = (struct mld_header *)p->payload;

  switch (mld_hdr->type) {
  case ICMP6_TYPE_MLQ: /* Multicast listener query. */
  {
    /* Is it a general query? */
    if (ip6_addr_isallnodes_linklocal(ip6_current_dest_addr()) &&
        ip6_addr_isany(&(mld_hdr->multicast_address))) {
      MLD6_STATS_INC(mld6.rx_general);
      /* Report all groups, except all nodes group, and if-local groups. */
      group = mld_group_list;
      while (group != NULL) {
        if ((group->netif == inp) &&
            (!(ip6_addr_ismulticast_iflocal(&(group->group_address)))) &&
            (!(ip6_addr_isallnodes_linklocal(&(group->group_address))))) {
          mld6_delayed_report(group, mld_hdr->max_resp_delay);
        }
        group = group->next;
      }
    }
    else {
      /* Have we joined this group?
       * We use IP6 destination address to have a memory aligned copy.
       * mld_hdr->multicast_address should be the same. */
      MLD6_STATS_INC(mld6.rx_group);
      group = mld6_lookfor_group(inp, ip6_current_dest_addr());
      if (group != NULL) {
        /* Schedule a report. */
        mld6_delayed_report(group, mld_hdr->max_resp_delay);
      }
    }
    break; /* ICMP6_TYPE_MLQ */
  }
  case ICMP6_TYPE_MLR: /* Multicast listener report. */
  {
    /* Have we joined this group?
     * We use IP6 destination address to have a memory aligned copy.
     * mld_hdr->multicast_address should be the same. */
    MLD6_STATS_INC(mld6.rx_report);
    group = mld6_lookfor_group(inp, ip6_current_dest_addr());
    if (group != NULL) {
      /* If we are waiting to report, cancel it. */
      if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) {
        group->timer = 0; /* stopped */
        group->group_state = MLD6_GROUP_IDLE_MEMBER;
        group->last_reporter_flag = 0;
      }
    }
    break; /* ICMP6_TYPE_MLR */
  }
  case ICMP6_TYPE_MLD: /* Multicast listener done. */
  {
    /* Do nothing, router will query us. */
    break; /* ICMP6_TYPE_MLD */
  }
  default:
    MLD6_STATS_INC(mld6.proterr);
    MLD6_STATS_INC(mld6.drop);
    break;
  }

  pbuf_free(p);
}