--- /dev/null
+/**
+ * @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.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.h"
+#include "lwip/snmp.h"
+#include "lwip/dhcp.h"
+#include "lwip/stats.h"
+#include "arch/perf.h"
+
+/**
+ * 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(struct ip_addr *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 | 2, ("ip_route: No route to 0x%"X32_F"\n", dest->addr));
+ 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
+ * @return the netif on which the packet was sent (NULL if it wasn't sent)
+ */
+static struct netif *
+ip_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
+{
+ struct netif *netif;
+
+ PERF_START;
+ /* Find network interface where to forward this IP packet to. */
+ netif = ip_route((struct ip_addr *)&(iphdr->dest));
+ if (netif == NULL) {
+ LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for 0x%"X32_F" found\n",
+ iphdr->dest.addr));
+ snmp_inc_ipoutnoroutes();
+ return (struct netif *)NULL;
+ }
+ /* 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"));
+ snmp_inc_ipoutnoroutes();
+ return (struct netif *)NULL;
+ }
+
+ /* 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 (struct netif *)NULL;
+ }
+
+ /* Incrementally update the IP checksum. */
+ if (IPH_CHKSUM(iphdr) >= htons(0xffff - 0x100)) {
+ IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100) + 1);
+ } else {
+ IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100));
+ }
+
+ LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to 0x%"X32_F"\n",
+ iphdr->dest.addr));
+
+ 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, (struct ip_addr *)&(iphdr->dest));
+ return netif;
+}
+#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 LWIP_DHCP
+ int check_ip_src=1;
+#endif /* LWIP_DHCP */
+
+ IP_STATS_INC(ip.recv);
+ snmp_inc_ipinreceives();
+
+ /* identify the IP header */
+ iphdr = p->payload;
+ if (IPH_V(iphdr) != 4) {
+ LWIP_DEBUGF(IP_DEBUG | 1, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
+ ip_debug_print(p);
+ pbuf_free(p);
+ IP_STATS_INC(ip.err);
+ IP_STATS_INC(ip.drop);
+ snmp_inc_ipinhdrerrors();
+ return ERR_OK;
+ }
+
+ /* obtain IP header length in number of 32-bit words */
+ iphdr_hlen = IPH_HL(iphdr);
+ /* calculate IP header length in bytes */
+ iphdr_hlen *= 4;
+ /* obtain ip length in bytes */
+ iphdr_len = ntohs(IPH_LEN(iphdr));
+
+ /* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
+ if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len)) {
+ if (iphdr_hlen > p->len)
+ LWIP_DEBUGF(IP_DEBUG | 2, ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
+ iphdr_hlen, p->len));
+ if (iphdr_len > p->tot_len)
+ LWIP_DEBUGF(IP_DEBUG | 2, ("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), "
+ "IP packet dropped.\n",
+ iphdr_len, p->tot_len));
+ /* free (drop) packet pbufs */
+ pbuf_free(p);
+ IP_STATS_INC(ip.lenerr);
+ IP_STATS_INC(ip.drop);
+ snmp_inc_ipindiscards();
+ return ERR_OK;
+ }
+
+ /* verify checksum */
+#if CHECKSUM_CHECK_IP
+ if (inet_chksum(iphdr, iphdr_hlen) != 0) {
+
+ LWIP_DEBUGF(IP_DEBUG | 2, ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
+ ip_debug_print(p);
+ pbuf_free(p);
+ IP_STATS_INC(ip.chkerr);
+ IP_STATS_INC(ip.drop);
+ snmp_inc_ipinhdrerrors();
+ return ERR_OK;
+ }
+#endif
+
+ /* Trim pbuf. This should have been done at the netif layer,
+ * but we'll do it anyway just to be sure that its done. */
+ pbuf_realloc(p, iphdr_len);
+
+ /* match packet against an interface, i.e. is this packet for us? */
+#if LWIP_IGMP
+ if (ip_addr_ismulticast(&(iphdr->dest))) {
+ if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &(iphdr->dest)))) {
+ netif = inp;
+ } else {
+ netif = NULL;
+ }
+ } else
+#endif /* LWIP_IGMP */
+ {
+ /* start trying with inp. if that's not acceptable, start walking the
+ list of configured netifs.
+ 'first' is used as a boolean to mark whether we started walking the list */
+ int first = 1;
+ netif = inp;
+ do {
+ LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest 0x%"X32_F" netif->ip_addr 0x%"X32_F" (0x%"X32_F", 0x%"X32_F", 0x%"X32_F")\n",
+ iphdr->dest.addr, netif->ip_addr.addr,
+ iphdr->dest.addr & netif->netmask.addr,
+ netif->ip_addr.addr & netif->netmask.addr,
+ iphdr->dest.addr & ~(netif->netmask.addr)));
+
+ /* interface is up and configured? */
+ if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) {
+ /* unicast to this interface address? */
+ if (ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr)) ||
+ /* or broadcast on this interface network address? */
+ ip_addr_isbroadcast(&(iphdr->dest), netif)) {
+ LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
+ netif->name[0], netif->name[1]));
+ /* break out of for loop */
+ break;
+ }
+ }
+ if (first) {
+ first = 0;
+ netif = netif_list;
+ } else {
+ netif = netif->next;
+ }
+ if (netif == inp) {
+ netif = netif->next;
+ }
+ } while(netif != NULL);
+ }
+
+#if LWIP_DHCP
+ /* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
+ * using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
+ * According to RFC 1542 section 3.1.1, referred by RFC 2131).
+ */
+ if (netif == NULL) {
+ /* remote port is DHCP server? */
+ if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
+ LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | 1, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
+ ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen))->dest)));
+ if (ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen))->dest) == DHCP_CLIENT_PORT) {
+ LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | 1, ("ip_input: DHCP packet accepted.\n"));
+ netif = inp;
+ check_ip_src = 0;
+ }
+ }
+ }
+#endif /* LWIP_DHCP */
+
+ /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
+#if LWIP_DHCP
+ if (check_ip_src)
+#endif /* LWIP_DHCP */
+ { if ((ip_addr_isbroadcast(&(iphdr->src), inp)) ||
+ (ip_addr_ismulticast(&(iphdr->src)))) {
+ /* packet source is not valid */
+ LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | 1, ("ip_input: packet source is not valid.\n"));
+ /* free (drop) packet pbufs */
+ pbuf_free(p);
+ IP_STATS_INC(ip.drop);
+ snmp_inc_ipinaddrerrors();
+ snmp_inc_ipindiscards();
+ return ERR_OK;
+ }
+ }
+
+ /* packet not for us? */
+ if (netif == NULL) {
+ /* packet not for us, route or discard */
+ LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | 1, ("ip_input: packet not for us.\n"));
+#if IP_FORWARD
+ /* non-broadcast packet? */
+ if (!ip_addr_isbroadcast(&(iphdr->dest), inp)) {
+ /* try to forward IP packet on (other) interfaces */
+ ip_forward(p, iphdr, inp);
+ } else
+#endif /* IP_FORWARD */
+ {
+ snmp_inc_ipinaddrerrors();
+ snmp_inc_ipindiscards();
+ }
+ pbuf_free(p);
+ return ERR_OK;
+ }
+ /* packet consists of multiple fragments? */
+ if ((IPH_OFFSET(iphdr) & htons(IP_OFFMASK | IP_MF)) != 0) {
+#if IP_REASSEMBLY /* packet fragment reassembly code present? */
+ LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04"X16_F" tot_len=%"U16_F" len=%"U16_F" MF=%"U16_F" offset=%"U16_F"), calling ip_reass()\n",
+ ntohs(IPH_ID(iphdr)), p->tot_len, ntohs(IPH_LEN(iphdr)), !!(IPH_OFFSET(iphdr) & htons(IP_MF)), (ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)*8));
+ /* reassemble the packet*/
+ p = ip_reass(p);
+ /* packet not fully reassembled yet? */
+ if (p == NULL) {
+ return ERR_OK;
+ }
+ iphdr = p->payload;
+#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
+ pbuf_free(p);
+ LWIP_DEBUGF(IP_DEBUG | 2, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
+ ntohs(IPH_OFFSET(iphdr))));
+ IP_STATS_INC(ip.opterr);
+ IP_STATS_INC(ip.drop);
+ /* unsupported protocol feature */
+ snmp_inc_ipinunknownprotos();
+ return ERR_OK;
+#endif /* IP_REASSEMBLY */
+ }
+
+#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
+
+#if LWIP_IGMP
+ /* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
+ if((iphdr_hlen > IP_HLEN && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
+#else
+ if (iphdr_hlen > IP_HLEN) {
+#endif /* LWIP_IGMP */
+ LWIP_DEBUGF(IP_DEBUG | 2, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
+ pbuf_free(p);
+ IP_STATS_INC(ip.opterr);
+ IP_STATS_INC(ip.drop);
+ /* unsupported protocol feature */
+ snmp_inc_ipinunknownprotos();
+ return ERR_OK;
+ }
+#endif /* IP_OPTIONS_ALLOWED == 0 */
+
+ /* send to upper layers */
+ LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
+ ip_debug_print(p);
+ LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
+
+#if LWIP_RAW
+ /* raw input did not eat the packet? */
+ if (raw_input(p, inp) == 0)
+#endif /* LWIP_RAW */
+ {
+
+ 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,&(iphdr->dest));
+ break;
+#endif /* LWIP_IGMP */
+ default:
+#if LWIP_ICMP
+ /* send ICMP destination protocol unreachable unless is was a broadcast */
+ if (!ip_addr_isbroadcast(&(iphdr->dest), inp) &&
+ !ip_addr_ismulticast(&(iphdr->dest))) {
+ p->payload = iphdr;
+ icmp_dest_unreach(p, ICMP_DUR_PROTO);
+ }
+#endif /* LWIP_ICMP */
+ pbuf_free(p);
+
+ LWIP_DEBUGF(IP_DEBUG | 2, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
+
+ IP_STATS_INC(ip.proterr);
+ IP_STATS_INC(ip.drop);
+ snmp_inc_ipinunknownprotos();
+ }
+ }
+
+ return ERR_OK;
+}
+
+/**
+ * Sends an IP packet on a network interface. This function constructs
+ * the IP header and calculates the IP header checksum. If the source
+ * IP address is NULL, the IP address of the outgoing network
+ * interface is filled in as source address.
+ * If the destination IP address is IP_HDRINCL, p is assumed to already
+ * include an IP header and p->payload points to it instead of the data.
+ *
+ * @param p the packet to send (p->payload points to the data, e.g. next
+ protocol header; if dest == IP_HDRINCL, p already includes an IP
+ header and p->payload points to that IP header)
+ * @param src the source IP address to send from (if src == IP_ADDR_ANY, the
+ * IP address of the netif used to send is used as source address)
+ * @param dest the destination IP address to send the packet to
+ * @param ttl the TTL value to be set in the IP header
+ * @param tos the TOS value to be set in the IP header
+ * @param proto the PROTOCOL to be set in the IP header
+ * @param netif the netif on which to send this packet
+ * @return ERR_OK if the packet was sent OK
+ * ERR_BUF if p doesn't have enough space for IP/LINK headers
+ * returns errors returned by netif->output
+ *
+ * @note ip_id: RFC791 "some host may be able to simply use
+ * unique identifiers independent of destination"
+ */
+err_t
+ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
+ u8_t ttl, u8_t tos,
+ u8_t proto, struct netif *netif)
+{
+ struct ip_hdr *iphdr;
+ static u16_t ip_id = 0;
+
+ snmp_inc_ipoutrequests();
+
+ /* Should the IP header be generated or is it already included in p? */
+ if (dest != IP_HDRINCL) {
+ /* generate IP header */
+ if (pbuf_header(p, IP_HLEN)) {
+ LWIP_DEBUGF(IP_DEBUG | 2, ("ip_output: not enough room for IP header in pbuf\n"));
+
+ IP_STATS_INC(ip.err);
+ snmp_inc_ipoutdiscards();
+ return ERR_BUF;
+ }
+
+ iphdr = p->payload;
+ LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
+ (p->len >= sizeof(struct ip_hdr)));
+
+ IPH_TTL_SET(iphdr, ttl);
+ IPH_PROTO_SET(iphdr, proto);
+
+ ip_addr_set(&(iphdr->dest), dest);
+
+ IPH_VHLTOS_SET(iphdr, 4, IP_HLEN / 4, tos);
+ IPH_LEN_SET(iphdr, htons(p->tot_len));
+ IPH_OFFSET_SET(iphdr, 0);
+ IPH_ID_SET(iphdr, htons(ip_id));
+ ++ip_id;
+
+ if (ip_addr_isany(src)) {
+ ip_addr_set(&(iphdr->src), &(netif->ip_addr));
+ } else {
+ ip_addr_set(&(iphdr->src), src);
+ }
+
+ IPH_CHKSUM_SET(iphdr, 0);
+#if CHECKSUM_GEN_IP
+ IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
+#endif
+ } else {
+ /* IP header already included in p */
+ iphdr = p->payload;
+ dest = &(iphdr->dest);
+ }
+
+#if IP_FRAG
+ /* don't fragment if interface has mtu set to 0 [loopif] */
+ if (netif->mtu && (p->tot_len > netif->mtu))
+ return ip_frag(p,netif,dest);
+#endif
+
+ IP_STATS_INC(ip.xmit);
+
+ LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
+ ip_debug_print(p);
+
+ LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
+
+ return netif->output(netif, p, dest);
+}
+
+/**
+ * Simple interface to ip_output_if. It finds the outgoing network
+ * interface and calls upon ip_output_if to do the actual work.
+ *
+ * @param p the packet to send (p->payload points to the data, e.g. next
+ protocol header; if dest == IP_HDRINCL, p already includes an IP
+ header and p->payload points to that IP header)
+ * @param src the source IP address to send from (if src == IP_ADDR_ANY, the
+ * IP address of the netif used to send is used as source address)
+ * @param dest the destination IP address to send the packet to
+ * @param ttl the TTL value to be set in the IP header
+ * @param tos the TOS value to be set in the IP header
+ * @param proto the PROTOCOL to be set in the IP header
+ *
+ * @return ERR_RTE if no route is found
+ * see ip_output_if() for more return values
+ */
+err_t
+ip_output(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
+ u8_t ttl, u8_t tos, u8_t proto)
+{
+ struct netif *netif;
+
+ if ((netif = ip_route(dest)) == NULL) {
+ return ERR_RTE;
+ }
+
+ return ip_output_if(p, src, dest, ttl, tos, proto, netif);
+}
+
+#if IP_DEBUG
+/* Print an IP header by using LWIP_DEBUGF
+ * @param p an IP packet, p->payload pointing to the IP header
+ */
+void
+ip_debug_print(struct pbuf *p)
+{
+ struct ip_hdr *iphdr = p->payload;
+ u8_t *payload;
+
+ payload = (u8_t *)iphdr + IP_HLEN;
+
+ LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
+ LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
+ LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" |%2"S16_F" | 0x%02"X16_F" | %5"U16_F" | (v, hl, tos, len)\n",
+ IPH_V(iphdr),
+ IPH_HL(iphdr),
+ IPH_TOS(iphdr),
+ ntohs(IPH_LEN(iphdr))));
+ LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
+ LWIP_DEBUGF(IP_DEBUG, ("| %5"U16_F" |%"U16_F"%"U16_F"%"U16_F"| %4"U16_F" | (id, flags, offset)\n",
+ ntohs(IPH_ID(iphdr)),
+ ntohs(IPH_OFFSET(iphdr)) >> 15 & 1,
+ ntohs(IPH_OFFSET(iphdr)) >> 14 & 1,
+ ntohs(IPH_OFFSET(iphdr)) >> 13 & 1,
+ ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK));
+ LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
+ LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | 0x%04"X16_F" | (ttl, proto, chksum)\n",
+ IPH_TTL(iphdr),
+ IPH_PROTO(iphdr),
+ ntohs(IPH_CHKSUM(iphdr))));
+ LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
+ LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (src)\n",
+ ip4_addr1(&iphdr->src),
+ ip4_addr2(&iphdr->src),
+ ip4_addr3(&iphdr->src),
+ ip4_addr4(&iphdr->src)));
+ LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
+ LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (dest)\n",
+ ip4_addr1(&iphdr->dest),
+ ip4_addr2(&iphdr->dest),
+ ip4_addr3(&iphdr->dest),
+ ip4_addr4(&iphdr->dest)));
+ LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
+}
+#endif /* IP_DEBUG */
