2 * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
5 * Redistribution and use in source and binary forms, with or without modification,
6 * are permitted provided that the following conditions are met:
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
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13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
19 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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21 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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27 * This file is part of the lwIP TCP/IP stack.
29 * Author: Adam Dunkels <adam@sics.se>
33 /* Some ICMP messages should be passed to the transport protocols. This
34 is not implemented. */
38 #include "lwip/icmp.h"
39 #include "lwip/inet.h"
43 #include "lwip/stats.h"
45 #include "lwip/snmp.h"
48 icmp_input(struct pbuf *p, struct netif *inp)
52 struct icmp_echo_hdr *iecho;
54 struct ip_addr tmpaddr;
57 ICMP_STATS_INC(icmp.recv);
58 snmp_inc_icmpinmsgs();
62 hlen = IPH_HL(iphdr) * 4;
63 if (pbuf_header(p, -((s16_t)hlen)) || (p->tot_len < sizeof(u16_t)*2)) {
64 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%u bytes) received\n", p->tot_len));
66 ICMP_STATS_INC(icmp.lenerr);
67 snmp_inc_icmpinerrors();
71 type = *((u8_t *)p->payload);
72 code = *(((u8_t *)p->payload)+1);
75 if (ip_addr_isbroadcast(&iphdr->dest, &inp->netmask) ||
76 ip_addr_ismulticast(&iphdr->dest)) {
77 LWIP_DEBUGF(ICMP_DEBUG, ("Smurf.\n"));
78 ICMP_STATS_INC(icmp.err);
82 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
83 LWIP_DEBUGF(DEMO_DEBUG, ("Pong!\n"));
84 if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
85 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
87 ICMP_STATS_INC(icmp.lenerr);
88 snmp_inc_icmpinerrors();
93 if (inet_chksum_pbuf(p) != 0) {
94 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
96 ICMP_STATS_INC(icmp.chkerr);
97 snmp_inc_icmpinerrors();
100 tmpaddr.addr = iphdr->src.addr;
101 iphdr->src.addr = iphdr->dest.addr;
102 iphdr->dest.addr = tmpaddr.addr;
103 ICMPH_TYPE_SET(iecho, ICMP_ER);
104 /* adjust the checksum */
105 if (iecho->chksum >= htons(0xffff - (ICMP_ECHO << 8))) {
106 iecho->chksum += htons(ICMP_ECHO << 8) + 1;
108 iecho->chksum += htons(ICMP_ECHO << 8);
110 ICMP_STATS_INC(icmp.xmit);
111 /* increase number of messages attempted to send */
112 snmp_inc_icmpoutmsgs();
113 /* increase number of echo replies attempted to send */
114 snmp_inc_icmpoutechoreps();
116 pbuf_header(p, hlen);
117 ip_output_if(p, &(iphdr->src), IP_HDRINCL,
118 IPH_TTL(iphdr), 0, IP_PROTO_ICMP, inp);
121 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %d code %d not supported.\n", (int)type, (int)code));
122 ICMP_STATS_INC(icmp.proterr);
123 ICMP_STATS_INC(icmp.drop);
129 icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t)
132 struct ip_hdr *iphdr;
133 struct icmp_dur_hdr *idur;
135 q = pbuf_alloc(PBUF_IP, 8 + IP_HLEN + 8, PBUF_RAM);
136 /* ICMP header + IP header + 8 bytes of data */
141 ICMPH_TYPE_SET(idur, ICMP_DUR);
142 ICMPH_CODE_SET(idur, t);
144 memcpy((char *)q->payload + 8, p->payload, IP_HLEN + 8);
146 /* calculate checksum */
148 idur->chksum = inet_chksum(idur, q->len);
149 ICMP_STATS_INC(icmp.xmit);
150 /* increase number of messages attempted to send */
151 snmp_inc_icmpoutmsgs();
152 /* increase number of destination unreachable messages attempted to send */
153 snmp_inc_icmpoutdestunreachs();
155 ip_output(q, NULL, &(iphdr->src),
156 ICMP_TTL, 0, IP_PROTO_ICMP);
162 icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t)
165 struct ip_hdr *iphdr;
166 struct icmp_te_hdr *tehdr;
168 q = pbuf_alloc(PBUF_IP, 8 + IP_HLEN + 8, PBUF_RAM);
171 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded from "));
172 ip_addr_debug_print(ICMP_DEBUG, &(iphdr->src));
173 LWIP_DEBUGF(ICMP_DEBUG, (" to "));
174 ip_addr_debug_print(ICMP_DEBUG, &(iphdr->dest));
175 LWIP_DEBUGF(ICMP_DEBUG, ("\n"));
178 ICMPH_TYPE_SET(tehdr, ICMP_TE);
179 ICMPH_CODE_SET(tehdr, t);
181 /* copy fields from original packet */
182 memcpy((char *)q->payload + 8, (char *)p->payload, IP_HLEN + 8);
184 /* calculate checksum */
186 tehdr->chksum = inet_chksum(tehdr, q->len);
187 ICMP_STATS_INC(icmp.xmit);
188 /* increase number of messages attempted to send */
189 snmp_inc_icmpoutmsgs();
190 /* increase number of destination unreachable messages attempted to send */
191 snmp_inc_icmpouttimeexcds();
192 ip_output(q, NULL, &(iphdr->src),
193 ICMP_TTL, 0, IP_PROTO_ICMP);
197 #endif /* IP_FORWARD */