modules/network/SMSTCPIP/icmp.c

   1 /*
   2  * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without modification,
   6  * are permitted provided that the following conditions are met:
   7  *
   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
  12  *    and/or other materials provided with the distribution.
  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.
  15  *
  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,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  21  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  24  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  25  * OF SUCH DAMAGE.
  26  *
  27  * This file is part of the lwIP TCP/IP stack.
  28  *
  29  * Author: Adam Dunkels <adam@sics.se>
  30  *
  31  */
  32
  33 /* Some ICMP messages should be passed to the transport protocols. This
  34    is not implemented. */
  35
  36 #include "lwip/opt.h"
  37
  38 #include "lwip/icmp.h"
  39 #include "lwip/inet.h"
  40 #include "lwip/ip.h"
  41 #include "lwip/def.h"
  42
  43 #include "lwip/stats.h"
  44
  45 #include "lwip/snmp.h"
  46
  47 #include <sysclib.h>
  48
  49 #include "smsutils.h"
  50
  51 void
  52 icmp_input(struct pbuf *p, struct netif *inp)
  53 {
  54   unsigned char type;
  55   unsigned char code;
  56   struct icmp_echo_hdr *iecho;
  57   struct ip_hdr *iphdr;
  58   struct ip_addr tmpaddr;
  59   u16_t hlen;
  60
  61   ICMP_STATS_INC(icmp.recv);
  62   snmp_inc_icmpinmsgs();
  63
  64
  65   iphdr = p->payload;
  66   hlen = IPH_HL(iphdr) * 4;
  67   if (pbuf_header(p, -((s16_t)hlen)) || (p->tot_len < sizeof(u16_t)*2)) {
  68     LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%u bytes) received\n", p->tot_len));
  69     pbuf_free(p);
  70     ICMP_STATS_INC(icmp.lenerr);
  71     snmp_inc_icmpinerrors();
  72     return;
  73   }
  74
  75   type = *((u8_t *)p->payload);
  76   code = *(((u8_t *)p->payload)+1);
  77   switch (type) {
  78   case ICMP_ECHO:
  79     if (ip_addr_isbroadcast(&iphdr->dest, &inp->netmask) ||
  80        ip_addr_ismulticast(&iphdr->dest)) {
  81       LWIP_DEBUGF(ICMP_DEBUG, ("Smurf.\n"));
  82       ICMP_STATS_INC(icmp.err);
  83       pbuf_free(p);
  84       return;
  85     }
  86     LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
  87     if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
  88       LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
  89       pbuf_free(p);
  90       ICMP_STATS_INC(icmp.lenerr);
  91       snmp_inc_icmpinerrors();
  92
  93       return;
  94     }
  95     iecho = p->payload;
  96     if (inet_chksum_pbuf(p) != 0) {
  97       LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
  98       pbuf_free(p);
  99       ICMP_STATS_INC(icmp.chkerr);
 100       snmp_inc_icmpinerrors();
 101       return;
 102     }
 103     tmpaddr.addr = iphdr->src.addr;
 104     iphdr->src.addr = iphdr->dest.addr;
 105     iphdr->dest.addr = tmpaddr.addr;
 106     ICMPH_TYPE_SET(iecho, ICMP_ER);
 107     /* adjust the checksum */
 108     if (iecho->chksum >= htons(0xffff - (ICMP_ECHO << 8))) {
 109       iecho->chksum += htons(ICMP_ECHO << 8) + 1;
 110     } else {
 111       iecho->chksum += htons(ICMP_ECHO << 8);
 112     }
 113     ICMP_STATS_INC(icmp.xmit);
 114     /* increase number of messages attempted to send */
 115     snmp_inc_icmpoutmsgs();
 116     /* increase number of echo replies attempted to send */
 117     snmp_inc_icmpoutechoreps();
 118
 119     pbuf_header(p, hlen);
 120     ip_output_if(p, &(iphdr->src), IP_HDRINCL,
 121                  IPH_TTL(iphdr), 0, IP_PROTO_ICMP, inp);
 122     break;
 123   default:
 124   LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %d code %d not supported.\n", (int)type, (int)code));
 125     ICMP_STATS_INC(icmp.proterr);
 126     ICMP_STATS_INC(icmp.drop);
 127   }
 128   pbuf_free(p);
 129 }
 130
 131 void
 132 icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t)
 133 {
 134   struct pbuf *q;
 135   struct ip_hdr *iphdr;
 136   struct icmp_dur_hdr *idur;
 137
 138   q = pbuf_alloc(PBUF_IP, 8 + IP_HLEN + 8, PBUF_RAM);
 139   /* ICMP header + IP header + 8 bytes of data */
 140
 141   iphdr = p->payload;
 142
 143   idur = q->payload;
 144   ICMPH_TYPE_SET(idur, ICMP_DUR);
 145   ICMPH_CODE_SET(idur, t);
 146
 147   mips_memcpy((char *)q->payload + 8, p->payload, IP_HLEN + 8);
 148
 149   /* calculate checksum */
 150   idur->chksum = 0;
 151   idur->chksum = inet_chksum(idur, q->len);
 152   ICMP_STATS_INC(icmp.xmit);
 153   /* increase number of messages attempted to send */
 154   snmp_inc_icmpoutmsgs();
 155   /* increase number of destination unreachable messages attempted to send */
 156   snmp_inc_icmpoutdestunreachs();
 157
 158   ip_output(q, NULL, &(iphdr->src),
 159             ICMP_TTL, 0, IP_PROTO_ICMP);
 160   pbuf_free(q);
 161 }
 162
 163 #if IP_FORWARD
 164 void
 165 icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t)
 166 {
 167   struct pbuf *q;
 168   struct ip_hdr *iphdr;
 169   struct icmp_te_hdr *tehdr;
 170
 171   q = pbuf_alloc(PBUF_IP, 8 + IP_HLEN + 8, PBUF_RAM);
 172
 173   iphdr = p->payload;
 174   LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded from "));
 175   ip_addr_debug_print(ICMP_DEBUG, &(iphdr->src));
 176   LWIP_DEBUGF(ICMP_DEBUG, (" to "));
 177   ip_addr_debug_print(ICMP_DEBUG, &(iphdr->dest));
 178   LWIP_DEBUGF(ICMP_DEBUG, ("\n"));
 179
 180   tehdr = q->payload;
 181   ICMPH_TYPE_SET(tehdr, ICMP_TE);
 182   ICMPH_CODE_SET(tehdr, t);
 183
 184   /* copy fields from original packet */
 185   mips_memcpy((char *)q->payload + 8, (char *)p->payload, IP_HLEN + 8);
 186
 187   /* calculate checksum */
 188   tehdr->chksum = 0;
 189   tehdr->chksum = inet_chksum(tehdr, q->len);
 190   ICMP_STATS_INC(icmp.xmit);
 191   /* increase number of messages attempted to send */
 192   snmp_inc_icmpoutmsgs();
 193   /* increase number of destination unreachable messages attempted to send */
 194   snmp_inc_icmpouttimeexcds();
 195   ip_output(q, NULL, &(iphdr->src),
 196             ICMP_TTL, 0, IP_PROTO_ICMP);
 197   pbuf_free(q);
 198 }
 199
 200 #endif /* IP_FORWARD */
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