| /* |
| * Copyright (c) 2001-2003 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> |
| * |
| */ |
| |
| /* Some ICMP messages should be passed to the transport protocols. This |
| is not implemented. */ |
| |
| #include "lwip/opt.h" |
| |
| #include "lwip/icmp.h" |
| #include "lwip/inet.h" |
| #include "lwip/ip.h" |
| #include "lwip/def.h" |
| |
| #include "lwip/stats.h" |
| |
| #include "lwip/snmp.h" |
| /*-----------------------------------------------------------------------------------*/ |
| void |
| icmp_input(struct pbuf *p, struct netif *inp) |
| { |
| unsigned char type; |
| unsigned char code; |
| struct icmp_echo_hdr *iecho; |
| struct ip_hdr *iphdr; |
| struct ip_addr tmpaddr; |
| u16_t hlen; |
| |
| #ifdef ICMP_STATS |
| ++lwip_stats.icmp.recv; |
| #endif /* ICMP_STATS */ |
| snmp_inc_icmpinmsgs(); |
| |
| |
| iphdr = p->payload; |
| hlen = IPH_HL(iphdr) * 4; |
| if (pbuf_header(p, -((s16_t)hlen)) || (p->tot_len < sizeof(u16_t)*2)) { |
| DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%u bytes) received\n", p->tot_len)); |
| pbuf_free(p); |
| #ifdef ICMP_STATS |
| ++lwip_stats.icmp.lenerr; |
| #endif /* ICMP_STATS */ |
| snmp_inc_icmpinerrors(); |
| return; |
| } |
| |
| type = *((u8_t *)p->payload); |
| code = *(((u8_t *)p->payload)+1); |
| switch (type) { |
| case ICMP_ECHO: |
| if (ip_addr_isbroadcast(&iphdr->dest, &inp->netmask) || |
| ip_addr_ismulticast(&iphdr->dest)) { |
| DEBUGF(ICMP_DEBUG, ("Smurf.\n")); |
| #ifdef ICMP_STATS |
| ++lwip_stats.icmp.err; |
| #endif /* ICMP_STATS */ |
| pbuf_free(p); |
| return; |
| } |
| DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n")); |
| DEBUGF(DEMO_DEBUG, ("Pong!\n")); |
| if (p->tot_len < sizeof(struct icmp_echo_hdr)) { |
| DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n")); |
| pbuf_free(p); |
| #ifdef ICMP_STATS |
| ++lwip_stats.icmp.lenerr; |
| #endif /* ICMP_STATS */ |
| snmp_inc_icmpinerrors(); |
| |
| return; |
| } |
| iecho = p->payload; |
| if (inet_chksum_pbuf(p) != 0) { |
| DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n")); |
| pbuf_free(p); |
| #ifdef ICMP_STATS |
| ++lwip_stats.icmp.chkerr; |
| #endif /* ICMP_STATS */ |
| snmp_inc_icmpinerrors(); |
| return; |
| } |
| tmpaddr.addr = iphdr->src.addr; |
| iphdr->src.addr = iphdr->dest.addr; |
| iphdr->dest.addr = tmpaddr.addr; |
| ICMPH_TYPE_SET(iecho, ICMP_ER); |
| /* adjust the checksum */ |
| if (iecho->chksum >= htons(0xffff - (ICMP_ECHO << 8))) { |
| iecho->chksum += htons(ICMP_ECHO << 8) + 1; |
| } else { |
| iecho->chksum += htons(ICMP_ECHO << 8); |
| } |
| #ifdef ICMP_STATS |
| ++lwip_stats.icmp.xmit; |
| #endif /* ICMP_STATS */ |
| /* increase number of messages attempted to send */ |
| snmp_inc_icmpoutmsgs(); |
| /* increase number of echo replies attempted to send */ |
| snmp_inc_icmpoutechoreps(); |
| |
| pbuf_header(p, hlen); |
| ip_output_if (p, &(iphdr->src), IP_HDRINCL, |
| IPH_TTL(iphdr), IP_PROTO_ICMP, inp); |
| break; |
| default: |
| DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %d code %d not supported.\n", (int)type, (int)code)); |
| #ifdef ICMP_STATS |
| ++lwip_stats.icmp.proterr; |
| ++lwip_stats.icmp.drop; |
| #endif /* ICMP_STATS */ |
| } |
| pbuf_free(p); |
| } |
| /*-----------------------------------------------------------------------------------*/ |
| void |
| icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t) |
| { |
| struct pbuf *q; |
| struct ip_hdr *iphdr; |
| struct icmp_dur_hdr *idur; |
| |
| q = pbuf_alloc(PBUF_IP, 8 + IP_HLEN + 8, PBUF_RAM); |
| /* ICMP header + IP header + 8 bytes of data */ |
| |
| iphdr = p->payload; |
| |
| idur = q->payload; |
| ICMPH_TYPE_SET(idur, ICMP_DUR); |
| ICMPH_CODE_SET(idur, t); |
| |
| memcpy((char *)q->payload + 8, p->payload, IP_HLEN + 8); |
| |
| /* calculate checksum */ |
| idur->chksum = 0; |
| idur->chksum = inet_chksum(idur, q->len); |
| #ifdef ICMP_STATS |
| ++lwip_stats.icmp.xmit; |
| #endif /* ICMP_STATS */ |
| /* increase number of messages attempted to send */ |
| snmp_inc_icmpoutmsgs(); |
| /* increase number of destination unreachable messages attempted to send */ |
| snmp_inc_icmpoutdestunreachs(); |
| |
| ip_output(q, NULL, &(iphdr->src), |
| ICMP_TTL, IP_PROTO_ICMP); |
| pbuf_free(q); |
| } |
| /*-----------------------------------------------------------------------------------*/ |
| #if IP_FORWARD |
| void |
| icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t) |
| { |
| struct pbuf *q; |
| struct ip_hdr *iphdr; |
| struct icmp_te_hdr *tehdr; |
| |
| q = pbuf_alloc(PBUF_IP, 8 + IP_HLEN + 8, PBUF_RAM); |
| |
| iphdr = p->payload; |
| #if ICMP_DEBUG |
| DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded from ")); |
| ip_addr_debug_print(&(iphdr->src)); |
| DEBUGF(ICMP_DEBUG, (" to ")); |
| ip_addr_debug_print(&(iphdr->dest)); |
| DEBUGF(ICMP_DEBUG, ("\n")); |
| #endif /* ICMP_DEBNUG */ |
| |
| tehdr = q->payload; |
| ICMPH_TYPE_SET(tehdr, ICMP_TE); |
| ICMPH_CODE_SET(tehdr, t); |
| |
| /* copy fields from original packet */ |
| memcpy((char *)q->payload + 8, (char *)p->payload, IP_HLEN + 8); |
| |
| /* calculate checksum */ |
| tehdr->chksum = 0; |
| tehdr->chksum = inet_chksum(tehdr, q->len); |
| #ifdef ICMP_STATS |
| ++lwip_stats.icmp.xmit; |
| #endif /* ICMP_STATS */ |
| /* increase number of messages attempted to send */ |
| snmp_inc_icmpoutmsgs(); |
| /* increase number of destination unreachable messages attempted to send */ |
| snmp_inc_icmpouttimeexcds(); |
| ip_output(q, NULL, &(iphdr->src), |
| ICMP_TTL, IP_PROTO_ICMP); |
| pbuf_free(q); |
| } |
| |
| #endif /* IP_FORWARDING > 0 */ |
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