Stripped down version of Segundos NetService library (http://mbed.org/users/segundo/libraries/NetServices ). I have removed all NetServices, and all functions which had been disabled. Use this version when you need only pure TCP or UDP functions - this library compiles faster.

Dependencies:   lwip lwip-sys

Dependents:   christmasLights device_server pop3demo device_server_udp ... more

Revision:
1:9d93f4dc2f46
Parent:
0:8b387bed54c2
--- a/lwip/core/ipv4/ip.c	Mon Jan 10 21:03:11 2011 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,857 +0,0 @@
-/**
- * @file
- * This is the IPv4 layer implementation for incoming and outgoing IP traffic.
- * 
- * @see ip_frag.c
- *
- */
-
-/*
- * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modification,
- * are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- *    this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- *    derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
- * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
- * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
- * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
- * OF SUCH DAMAGE.
- *
- * This file is part of the lwIP TCP/IP stack.
- *
- * Author: Adam Dunkels <adam@sics.se>
- *
- */
-
-#include "lwip/opt.h"
-#include "lwip/ip.h"
-#include "lwip/def.h"
-#include "lwip/mem.h"
-#include "lwip/ip_frag.h"
-#include "lwip/inet_chksum.h"
-#include "lwip/netif.h"
-#include "lwip/icmp.h"
-#include "lwip/igmp.h"
-#include "lwip/raw.h"
-#include "lwip/udp.h"
-#include "lwip/tcp_impl.h"
-#include "lwip/snmp.h"
-#include "lwip/dhcp.h"
-#include "lwip/autoip.h"
-#include "lwip/stats.h"
-#include "arch/perf.h"
-
-#include <string.h>
-
-/** Set this to 0 in the rare case of wanting to call an extra function to
- * generate the IP checksum (in contrast to calculating it on-the-fly). */
-#ifndef LWIP_INLINE_IP_CHKSUM
-#define LWIP_INLINE_IP_CHKSUM   1
-#endif
-#if LWIP_INLINE_IP_CHKSUM && CHECKSUM_GEN_IP
-#define CHECKSUM_GEN_IP_INLINE  1
-#else
-#define CHECKSUM_GEN_IP_INLINE  0
-#endif
-
-#if LWIP_DHCP || defined(LWIP_IP_ACCEPT_UDP_PORT)
-#define IP_ACCEPT_LINK_LAYER_ADDRESSING 1
-
-/** Some defines for DHCP to let link-layer-addressed packets through while the
- * netif is down.
- * To use this in your own application/protocol, define LWIP_IP_ACCEPT_UDP_PORT
- * to return 1 if the port is accepted and 0 if the port is not accepted.
- */
-#if LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT)
-/* accept DHCP client port and custom port */
-#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (((port) == PP_NTOHS(DHCP_CLIENT_PORT)) \
-         || (LWIP_IP_ACCEPT_UDP_PORT(port)))
-#elif defined(LWIP_IP_ACCEPT_UDP_PORT) /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
-/* accept custom port only */
-#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (LWIP_IP_ACCEPT_UDP_PORT(dst_port))
-#else /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
-/* accept DHCP client port only */
-#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) ((port) == PP_NTOHS(DHCP_CLIENT_PORT))
-#endif /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
-
-#else /* LWIP_DHCP */
-#define IP_ACCEPT_LINK_LAYER_ADDRESSING 0
-#endif /* LWIP_DHCP */
-
-/**
- * The interface that provided the packet for the current callback
- * invocation.
- */
-struct netif *current_netif;
-
-/**
- * Header of the input packet currently being processed.
- */
-const struct ip_hdr *current_header;
-/** Source IP address of current_header */
-ip_addr_t current_iphdr_src;
-/** Destination IP address of current_header */
-ip_addr_t current_iphdr_dest;
-
-/** The IP header ID of the next outgoing IP packet */
-static u16_t ip_id;
-
-/**
- * Finds the appropriate network interface for a given IP address. It
- * searches the list of network interfaces linearly. A match is found
- * if the masked IP address of the network interface equals the masked
- * IP address given to the function.
- *
- * @param dest the destination IP address for which to find the route
- * @return the netif on which to send to reach dest
- */
-struct netif *
-ip_route(ip_addr_t *dest)
-{
-  struct netif *netif;
-
-  /* iterate through netifs */
-  for(netif = netif_list; netif != NULL; netif = netif->next) {
-    /* network mask matches? */
-    if (netif_is_up(netif)) {
-      if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {
-        /* return netif on which to forward IP packet */
-        return netif;
-      }
-    }
-  }
-  if ((netif_default == NULL) || (!netif_is_up(netif_default))) {
-    LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
-      ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
-    IP_STATS_INC(ip.rterr);
-    snmp_inc_ipoutnoroutes();
-    return NULL;
-  }
-  /* no matching netif found, use default netif */
-  return netif_default;
-}
-
-#if IP_FORWARD
-/**
- * Forwards an IP packet. It finds an appropriate route for the
- * packet, decrements the TTL value of the packet, adjusts the
- * checksum and outputs the packet on the appropriate interface.
- *
- * @param p the packet to forward (p->payload points to IP header)
- * @param iphdr the IP header of the input packet
- * @param inp the netif on which this packet was received
- */
-static void
-ip_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
-{
-  struct netif *netif;
-
-  PERF_START;
-
-  /* RFC3927 2.7: do not forward link-local addresses */
-  if (ip_addr_islinklocal(&current_iphdr_dest)) {
-    LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
-      ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
-      ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
-    goto return_noroute;
-  }
-
-  /* Find network interface where to forward this IP packet to. */
-  netif = ip_route(&current_iphdr_dest);
-  if (netif == NULL) {
-    LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
-      ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
-      ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
-    goto return_noroute;
-  }
-  /* Do not forward packets onto the same network interface on which
-   * they arrived. */
-  if (netif == inp) {
-    LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not bouncing packets back on incoming interface.\n"));
-    goto return_noroute;
-  }
-
-  /* decrement TTL */
-  IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
-  /* send ICMP if TTL == 0 */
-  if (IPH_TTL(iphdr) == 0) {
-    snmp_inc_ipinhdrerrors();
-#if LWIP_ICMP
-    /* Don't send ICMP messages in response to ICMP messages */
-    if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
-      icmp_time_exceeded(p, ICMP_TE_TTL);
-    }
-#endif /* LWIP_ICMP */
-    return;
-  }
-
-  /* Incrementally update the IP checksum. */
-  if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffff - 0x100)) {
-    IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1);
-  } else {
-    IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100));
-  }
-
-  LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
-    ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
-    ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
-
-  IP_STATS_INC(ip.fw);
-  IP_STATS_INC(ip.xmit);
-  snmp_inc_ipforwdatagrams();
-
-  PERF_STOP("ip_forward");
-  /* transmit pbuf on chosen interface */
-  netif->output(netif, p, &current_iphdr_dest);
-  return;
-return_noroute:
-  snmp_inc_ipoutnoroutes();
-}
-#endif /* IP_FORWARD */
-
-/**
- * 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)
-{
-  struct ip_hdr *iphdr;
-  struct netif *netif;
-  u16_t iphdr_hlen;
-  u16_t iphdr_len;
-#if IP_ACCEPT_LINK_LAYER_ADDRESSING
-  int check_ip_src=1;
-#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
-
-  IP_STATS_INC(ip.recv);
-  snmp_inc_ipinreceives();
-
-  /* identify the IP header */
-  iphdr = (struct ip_hdr *)p->payload;
-  if (IPH_V(iphdr) != 4) {
-    LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_WARNING, ("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 | LWIP_DBG_LEVEL_SERIOUS,
-        ("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 | LWIP_DBG_LEVEL_SERIOUS,
-        ("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 | LWIP_DBG_LEVEL_SERIOUS,
-      ("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);
-
-  /* copy IP addresses to aligned ip_addr_t */
-  ip_addr_copy(current_iphdr_dest, iphdr->dest);
-  ip_addr_copy(current_iphdr_src, iphdr->src);
-
-  /* match packet against an interface, i.e. is this packet for us? */
-#if LWIP_IGMP
-  if (ip_addr_ismulticast(&current_iphdr_dest)) {
-    if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &current_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",
-          ip4_addr_get_u32(&iphdr->dest), ip4_addr_get_u32(&netif->ip_addr),
-          ip4_addr_get_u32(&iphdr->dest) & ip4_addr_get_u32(&netif->netmask),
-          ip4_addr_get_u32(&netif->ip_addr) & ip4_addr_get_u32(&netif->netmask),
-          ip4_addr_get_u32(&iphdr->dest) & ~ip4_addr_get_u32(&netif->netmask)));
-
-      /* 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(&current_iphdr_dest, &(netif->ip_addr)) ||
-            /* or broadcast on this interface network address? */
-            ip_addr_isbroadcast(&current_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 LWIP_AUTOIP
-        /* connections to link-local addresses must persist after changing
-           the netif's address (RFC3927 ch. 1.9) */
-        if ((netif->autoip != NULL) &&
-            ip_addr_cmp(&current_iphdr_dest, &(netif->autoip->llipaddr))) {
-          LWIP_DEBUGF(IP_DEBUG, ("ip_input: LLA packet accepted on interface %c%c\n",
-              netif->name[0], netif->name[1]));
-          /* break out of for loop */
-          break;
-        }
-#endif /* LWIP_AUTOIP */
-      }
-      if (first) {
-        first = 0;
-        netif = netif_list;
-      } else {
-        netif = netif->next;
-      }
-      if (netif == inp) {
-        netif = netif->next;
-      }
-    } while(netif != NULL);
-  }
-
-#if IP_ACCEPT_LINK_LAYER_ADDRESSING
-  /* 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 you want to accept private broadcast communication while a netif is down,
-   * define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
-   *
-   * #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
-   */
-  if (netif == NULL) {
-    /* remote port is DHCP server? */
-    if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
-      struct udp_hdr *udphdr = (struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen);
-      LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
-        ntohs(udphdr->dest)));
-      if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
-        LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: DHCP packet accepted.\n"));
-        netif = inp;
-        check_ip_src = 0;
-      }
-    }
-  }
-#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
-
-  /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
-#if IP_ACCEPT_LINK_LAYER_ADDRESSING
-  /* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
-  if (check_ip_src && !ip_addr_isany(&current_iphdr_src))
-#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
-  {  if ((ip_addr_isbroadcast(&current_iphdr_src, inp)) ||
-         (ip_addr_ismulticast(&current_iphdr_src))) {
-      /* packet source is not valid */
-      LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("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, ("ip_input: packet not for us.\n"));
-#if IP_FORWARD
-    /* non-broadcast packet? */
-    if (!ip_addr_isbroadcast(&current_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) & PP_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) & PP_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 = (struct ip_hdr *)p->payload;
-#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
-    pbuf_free(p);
-    LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("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 | LWIP_DBG_LEVEL_SERIOUS, ("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 */
-  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));
-
-  current_netif = inp;
-  current_header = iphdr;
-
-#if LWIP_RAW
-  /* raw input did not eat the packet? */
-  if (raw_input(p, inp) == 0)
-#endif /* LWIP_RAW */
-  {
-
-    switch (IPH_PROTO(iphdr)) {
-#if LWIP_UDP
-    case IP_PROTO_UDP:
-#if LWIP_UDPLITE
-    case IP_PROTO_UDPLITE:
-#endif /* LWIP_UDPLITE */
-      snmp_inc_ipindelivers();
-      udp_input(p, inp);
-      break;
-#endif /* LWIP_UDP */
-#if LWIP_TCP
-    case IP_PROTO_TCP:
-      snmp_inc_ipindelivers();
-      tcp_input(p, inp);
-      break;
-#endif /* LWIP_TCP */
-#if LWIP_ICMP
-    case IP_PROTO_ICMP:
-      snmp_inc_ipindelivers();
-      icmp_input(p, inp);
-      break;
-#endif /* LWIP_ICMP */
-#if LWIP_IGMP
-    case IP_PROTO_IGMP:
-      igmp_input(p, inp, &current_iphdr_dest);
-      break;
-#endif /* LWIP_IGMP */
-    default:
-#if LWIP_ICMP
-      /* send ICMP destination protocol unreachable unless is was a broadcast */
-      if (!ip_addr_isbroadcast(&current_iphdr_dest, inp) &&
-          !ip_addr_ismulticast(&current_iphdr_dest)) {
-        p->payload = iphdr;
-        icmp_dest_unreach(p, ICMP_DUR_PROTO);
-      }
-#endif /* LWIP_ICMP */
-      pbuf_free(p);
-
-      LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
-
-      IP_STATS_INC(ip.proterr);
-      IP_STATS_INC(ip.drop);
-      snmp_inc_ipinunknownprotos();
-    }
-  }
-
-  current_netif = NULL;
-  current_header = NULL;
-  ip_addr_set_any(&current_iphdr_src);
-  ip_addr_set_any(&current_iphdr_dest);
-
-  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, ip_addr_t *src, ip_addr_t *dest,
-             u8_t ttl, u8_t tos,
-             u8_t proto, struct netif *netif)
-{
-#if IP_OPTIONS_SEND
-  return ip_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
-}
-
-/**
- * Same as ip_output_if() but with the possibility to include IP options:
- *
- * @ param ip_options pointer to the IP options, copied into the IP header
- * @ param optlen length of ip_options
- */
-err_t ip_output_if_opt(struct pbuf *p, ip_addr_t *src, ip_addr_t *dest,
-       u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
-       u16_t optlen)
-{
-#endif /* IP_OPTIONS_SEND */
-  struct ip_hdr *iphdr;
-  ip_addr_t dest_addr;
-#if CHECKSUM_GEN_IP_INLINE
-  u32_t chk_sum = 0;
-#endif /* CHECKSUM_GEN_IP_INLINE */
-
-  /* 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);
-
-  snmp_inc_ipoutrequests();
-
-  /* Should the IP header be generated or is it already included in p? */
-  if (dest != IP_HDRINCL) {
-    u16_t ip_hlen = IP_HLEN;
-#if IP_OPTIONS_SEND
-    u16_t optlen_aligned = 0;
-    if (optlen != 0) {
-#if CHECKSUM_GEN_IP_INLINE
-      int i;
-#endif /* CHECKSUM_GEN_IP_INLINE */
-      /* round up to a multiple of 4 */
-      optlen_aligned = ((optlen + 3) & ~3);
-      ip_hlen += optlen_aligned;
-      /* First write in the IP options */
-      if (pbuf_header(p, optlen_aligned)) {
-        LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip_output_if_opt: not enough room for IP options in pbuf\n"));
-        IP_STATS_INC(ip.err);
-        snmp_inc_ipoutdiscards();
-        return ERR_BUF;
-      }
-      MEMCPY(p->payload, ip_options, optlen);
-      if (optlen < optlen_aligned) {
-        /* zero the remaining bytes */
-        memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
-      }
-#if CHECKSUM_GEN_IP_INLINE
-      for (i = 0; i < optlen_aligned; i += sizeof(u16_t)) {
-        chk_sum += ((u16_t*)p->payload)[i];
-      }
-#endif /* CHECKSUM_GEN_IP_INLINE */
-    }
-#endif /* IP_OPTIONS_SEND */
-    /* generate IP header */
-    if (pbuf_header(p, IP_HLEN)) {
-      LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip_output: not enough room for IP header in pbuf\n"));
-
-      IP_STATS_INC(ip.err);
-      snmp_inc_ipoutdiscards();
-      return ERR_BUF;
-    }
-
-    iphdr = (struct ip_hdr *)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);
-#if CHECKSUM_GEN_IP_INLINE
-    chk_sum += LWIP_MAKE_U16(proto, ttl);
-#endif /* CHECKSUM_GEN_IP_INLINE */
-
-    /* dest cannot be NULL here */
-    ip_addr_copy(iphdr->dest, *dest);
-#if CHECKSUM_GEN_IP_INLINE
-    chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
-    chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
-#endif /* CHECKSUM_GEN_IP_INLINE */
-
-    IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos);
-#if CHECKSUM_GEN_IP_INLINE
-    chk_sum += iphdr->_v_hl_tos;
-#endif /* CHECKSUM_GEN_IP_INLINE */
-    IPH_LEN_SET(iphdr, htons(p->tot_len));
-#if CHECKSUM_GEN_IP_INLINE
-    chk_sum += iphdr->_len;
-#endif /* CHECKSUM_GEN_IP_INLINE */
-    IPH_OFFSET_SET(iphdr, 0);
-    IPH_ID_SET(iphdr, htons(ip_id));
-#if CHECKSUM_GEN_IP_INLINE
-    chk_sum += iphdr->_id;
-#endif /* CHECKSUM_GEN_IP_INLINE */
-    ++ip_id;
-
-    if (ip_addr_isany(src)) {
-      ip_addr_copy(iphdr->src, netif->ip_addr);
-    } else {
-      /* src cannot be NULL here */
-      ip_addr_copy(iphdr->src, *src);
-    }
-
-#if CHECKSUM_GEN_IP_INLINE
-    chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
-    chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
-    chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
-    chk_sum = (chk_sum >> 16) + chk_sum;
-    chk_sum = ~chk_sum;
-    iphdr->_chksum = chk_sum; /* network order */
-#else /* CHECKSUM_GEN_IP_INLINE */
-    IPH_CHKSUM_SET(iphdr, 0);
-#if CHECKSUM_GEN_IP
-    IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
-#endif
-#endif /* CHECKSUM_GEN_IP_INLINE */
-  } else {
-    /* IP header already included in p */
-    iphdr = (struct ip_hdr *)p->payload;
-    ip_addr_copy(dest_addr, iphdr->dest);
-    dest = &dest_addr;
-  }
-
-  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);
-
-#if ENABLE_LOOPBACK
-  if (ip_addr_cmp(dest, &netif->ip_addr)) {
-    /* Packet to self, enqueue it for loopback */
-    LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
-    return netif_loop_output(netif, p, dest);
-  }
-#if LWIP_IGMP
-  if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
-    netif_loop_output(netif, p, dest);
-  }
-#endif /* LWIP_IGMP */
-#endif /* ENABLE_LOOPBACK */
-#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_FRAG */
-
-  LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
-  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, ip_addr_t *src, ip_addr_t *dest,
-          u8_t ttl, u8_t tos, u8_t proto)
-{
-  struct netif *netif;
-
-  /* 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);
-
-  if ((netif = ip_route(dest)) == NULL) {
-    LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
-      ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
-    IP_STATS_INC(ip.rterr);
-    return ERR_RTE;
-  }
-
-  return ip_output_if(p, src, dest, ttl, tos, proto, netif);
-}
-
-#if LWIP_NETIF_HWADDRHINT
-/** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
- *  before calling ip_output_if.
- *
- * @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 addr_hint address hint pointer set to netif->addr_hint before
- *        calling ip_output_if()
- *
- * @return ERR_RTE if no route is found
- *         see ip_output_if() for more return values
- */
-err_t
-ip_output_hinted(struct pbuf *p, ip_addr_t *src, ip_addr_t *dest,
-          u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint)
-{
-  struct netif *netif;
-  err_t err;
-
-  /* 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);
-
-  if ((netif = ip_route(dest)) == NULL) {
-    LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
-      ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
-    IP_STATS_INC(ip.rterr);
-    return ERR_RTE;
-  }
-
-  netif->addr_hint = addr_hint;
-  err = ip_output_if(p, src, dest, ttl, tos, proto, netif);
-  netif->addr_hint = NULL;
-
-  return err;
-}
-#endif /* LWIP_NETIF_HWADDRHINT*/
-
-#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 = (struct ip_hdr *)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_16(&iphdr->src),
-                    ip4_addr2_16(&iphdr->src),
-                    ip4_addr3_16(&iphdr->src),
-                    ip4_addr4_16(&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_16(&iphdr->dest),
-                    ip4_addr2_16(&iphdr->dest),
-                    ip4_addr3_16(&iphdr->dest),
-                    ip4_addr4_16(&iphdr->dest)));
-  LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
-}
-#endif /* IP_DEBUG */