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Example_RTOS
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lwip_icmp6.c
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00001 /** 00002 * @file 00003 * 00004 * IPv6 version of ICMP, as per RFC 4443. 00005 */ 00006 00007 /* 00008 * Copyright (c) 2010 Inico Technologies Ltd. 00009 * All rights reserved. 00010 * 00011 * Redistribution and use in source and binary forms, with or without modification, 00012 * are permitted provided that the following conditions are met: 00013 * 00014 * 1. Redistributions of source code must retain the above copyright notice, 00015 * this list of conditions and the following disclaimer. 00016 * 2. Redistributions in binary form must reproduce the above copyright notice, 00017 * this list of conditions and the following disclaimer in the documentation 00018 * and/or other materials provided with the distribution. 00019 * 3. The name of the author may not be used to endorse or promote products 00020 * derived from this software without specific prior written permission. 00021 * 00022 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 00023 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 00024 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 00025 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00026 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 00027 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00028 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 00029 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 00030 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 00031 * OF SUCH DAMAGE. 00032 * 00033 * This file is part of the lwIP TCP/IP stack. 00034 * 00035 * Author: Ivan Delamer <delamer@inicotech.com> 00036 * 00037 * 00038 * Please coordinate changes and requests with Ivan Delamer 00039 * <delamer@inicotech.com> 00040 */ 00041 00042 #include "lwip/opt.h" 00043 00044 #if LWIP_ICMP6 && LWIP_IPV6 /* don't build if not configured for use in lwipopts.h */ 00045 00046 #include "lwip/icmp6.h" 00047 #include "lwip/prot/icmp6.h" 00048 #include "lwip/ip6.h" 00049 #include "lwip/ip6_addr.h" 00050 #include "lwip/inet_chksum.h" 00051 #include "lwip/pbuf.h" 00052 #include "lwip/netif.h" 00053 #include "lwip/nd6.h" 00054 #include "lwip/mld6.h" 00055 #include "lwip/ip.h" 00056 #include "lwip/stats.h" 00057 00058 #include <string.h> 00059 00060 #ifndef LWIP_ICMP6_DATASIZE 00061 #define LWIP_ICMP6_DATASIZE 8 00062 #endif 00063 #if LWIP_ICMP6_DATASIZE == 0 00064 #define LWIP_ICMP6_DATASIZE 8 00065 #endif 00066 00067 /* Forward declarations */ 00068 static void icmp6_send_response(struct pbuf *p, u8_t code, u32_t data, u8_t type); 00069 00070 00071 /** 00072 * Process an input ICMPv6 message. Called by ip6_input. 00073 * 00074 * Will generate a reply for echo requests. Other messages are forwarded 00075 * to nd6_input, or mld6_input. 00076 * 00077 * @param p the mld packet, p->payload pointing to the icmpv6 header 00078 * @param inp the netif on which this packet was received 00079 */ 00080 void 00081 icmp6_input(struct pbuf *p, struct netif *inp) 00082 { 00083 struct icmp6_hdr *icmp6hdr; 00084 struct pbuf *r; 00085 const ip6_addr_t *reply_src; 00086 00087 ICMP6_STATS_INC(icmp6.recv); 00088 00089 /* Check that ICMPv6 header fits in payload */ 00090 if (p->len < sizeof(struct icmp6_hdr)) { 00091 /* drop short packets */ 00092 pbuf_free(p); 00093 ICMP6_STATS_INC(icmp6.lenerr); 00094 ICMP6_STATS_INC(icmp6.drop); 00095 return; 00096 } 00097 00098 icmp6hdr = (struct icmp6_hdr *)p->payload; 00099 00100 #if CHECKSUM_CHECK_ICMP6 00101 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP6) { 00102 if (ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->tot_len, ip6_current_src_addr(), 00103 ip6_current_dest_addr()) != 0) { 00104 /* Checksum failed */ 00105 pbuf_free(p); 00106 ICMP6_STATS_INC(icmp6.chkerr); 00107 ICMP6_STATS_INC(icmp6.drop); 00108 return; 00109 } 00110 } 00111 #endif /* CHECKSUM_CHECK_ICMP6 */ 00112 00113 switch (icmp6hdr->type) { 00114 case ICMP6_TYPE_NA: /* Neighbor advertisement */ 00115 case ICMP6_TYPE_NS: /* Neighbor solicitation */ 00116 case ICMP6_TYPE_RA: /* Router advertisement */ 00117 case ICMP6_TYPE_RD: /* Redirect */ 00118 case ICMP6_TYPE_PTB: /* Packet too big */ 00119 nd6_input(p, inp); 00120 return; 00121 break; 00122 case ICMP6_TYPE_RS: 00123 #if LWIP_IPV6_FORWARD 00124 /* @todo implement router functionality */ 00125 #endif 00126 break; 00127 #if LWIP_IPV6_MLD 00128 case ICMP6_TYPE_MLQ: 00129 case ICMP6_TYPE_MLR: 00130 case ICMP6_TYPE_MLD: 00131 mld6_input(p, inp); 00132 return; 00133 break; 00134 #endif 00135 case ICMP6_TYPE_EREQ: 00136 #if !LWIP_MULTICAST_PING 00137 /* multicast destination address? */ 00138 if (ip6_addr_ismulticast(ip6_current_dest_addr())) { 00139 /* drop */ 00140 pbuf_free(p); 00141 ICMP6_STATS_INC(icmp6.drop); 00142 return; 00143 } 00144 #endif /* LWIP_MULTICAST_PING */ 00145 00146 /* Allocate reply. */ 00147 r = pbuf_alloc(PBUF_IP, p->tot_len, PBUF_RAM); 00148 if (r == NULL) { 00149 /* drop */ 00150 pbuf_free(p); 00151 ICMP6_STATS_INC(icmp6.memerr); 00152 return; 00153 } 00154 00155 /* Copy echo request. */ 00156 if (pbuf_copy(r, p) != ERR_OK) { 00157 /* drop */ 00158 pbuf_free(p); 00159 pbuf_free(r); 00160 ICMP6_STATS_INC(icmp6.err); 00161 return; 00162 } 00163 00164 /* Determine reply source IPv6 address. */ 00165 #if LWIP_MULTICAST_PING 00166 if (ip6_addr_ismulticast(ip6_current_dest_addr())) { 00167 reply_src = ip_2_ip6(ip6_select_source_address(inp, ip6_current_src_addr())); 00168 if (reply_src == NULL) { 00169 /* drop */ 00170 pbuf_free(p); 00171 pbuf_free(r); 00172 ICMP6_STATS_INC(icmp6.rterr); 00173 return; 00174 } 00175 } 00176 else 00177 #endif /* LWIP_MULTICAST_PING */ 00178 { 00179 reply_src = ip6_current_dest_addr(); 00180 } 00181 00182 /* Set fields in reply. */ 00183 ((struct icmp6_echo_hdr *)(r->payload))->type = ICMP6_TYPE_EREP; 00184 ((struct icmp6_echo_hdr *)(r->payload))->chksum = 0; 00185 #if CHECKSUM_GEN_ICMP6 00186 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP6) { 00187 ((struct icmp6_echo_hdr *)(r->payload))->chksum = ip6_chksum_pseudo(r, 00188 IP6_NEXTH_ICMP6, r->tot_len, reply_src, ip6_current_src_addr()); 00189 } 00190 #endif /* CHECKSUM_GEN_ICMP6 */ 00191 00192 /* Send reply. */ 00193 ICMP6_STATS_INC(icmp6.xmit); 00194 ip6_output_if(r, reply_src, ip6_current_src_addr(), 00195 LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, inp); 00196 pbuf_free(r); 00197 00198 break; 00199 default: 00200 ICMP6_STATS_INC(icmp6.proterr); 00201 ICMP6_STATS_INC(icmp6.drop); 00202 break; 00203 } 00204 00205 pbuf_free(p); 00206 } 00207 00208 00209 /** 00210 * Send an icmpv6 'destination unreachable' packet. 00211 * 00212 * @param p the input packet for which the 'unreachable' should be sent, 00213 * p->payload pointing to the IPv6 header 00214 * @param c ICMPv6 code for the unreachable type 00215 */ 00216 void 00217 icmp6_dest_unreach(struct pbuf *p, enum icmp6_dur_code c) 00218 { 00219 icmp6_send_response(p, c, 0, ICMP6_TYPE_DUR); 00220 } 00221 00222 /** 00223 * Send an icmpv6 'packet too big' packet. 00224 * 00225 * @param p the input packet for which the 'packet too big' should be sent, 00226 * p->payload pointing to the IPv6 header 00227 * @param mtu the maximum mtu that we can accept 00228 */ 00229 void 00230 icmp6_packet_too_big(struct pbuf *p, u32_t mtu) 00231 { 00232 icmp6_send_response(p, 0, mtu, ICMP6_TYPE_PTB); 00233 } 00234 00235 /** 00236 * Send an icmpv6 'time exceeded' packet. 00237 * 00238 * @param p the input packet for which the 'unreachable' should be sent, 00239 * p->payload pointing to the IPv6 header 00240 * @param c ICMPv6 code for the time exceeded type 00241 */ 00242 void 00243 icmp6_time_exceeded(struct pbuf *p, enum icmp6_te_code c) 00244 { 00245 icmp6_send_response(p, c, 0, ICMP6_TYPE_TE); 00246 } 00247 00248 /** 00249 * Send an icmpv6 'parameter problem' packet. 00250 * 00251 * @param p the input packet for which the 'param problem' should be sent, 00252 * p->payload pointing to the IP header 00253 * @param c ICMPv6 code for the param problem type 00254 * @param pointer the pointer to the byte where the parameter is found 00255 */ 00256 void 00257 icmp6_param_problem(struct pbuf *p, enum icmp6_pp_code c, u32_t pointer) 00258 { 00259 icmp6_send_response(p, c, pointer, ICMP6_TYPE_PP); 00260 } 00261 00262 /** 00263 * Send an ICMPv6 packet in response to an incoming packet. 00264 * 00265 * @param p the input packet for which the response should be sent, 00266 * p->payload pointing to the IPv6 header 00267 * @param code Code of the ICMPv6 header 00268 * @param data Additional 32-bit parameter in the ICMPv6 header 00269 * @param type Type of the ICMPv6 header 00270 */ 00271 static void 00272 icmp6_send_response(struct pbuf *p, u8_t code, u32_t data, u8_t type) 00273 { 00274 struct pbuf *q; 00275 struct icmp6_hdr *icmp6hdr; 00276 const ip6_addr_t *reply_src; 00277 ip6_addr_t *reply_dest; 00278 ip6_addr_t reply_src_local, reply_dest_local; 00279 struct ip6_hdr *ip6hdr; 00280 struct netif *netif; 00281 00282 /* ICMPv6 header + IPv6 header + data */ 00283 q = pbuf_alloc(PBUF_IP, sizeof(struct icmp6_hdr) + IP6_HLEN + LWIP_ICMP6_DATASIZE, 00284 PBUF_RAM); 00285 if (q == NULL) { 00286 LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded: failed to allocate pbuf for ICMPv6 packet.\n")); 00287 ICMP6_STATS_INC(icmp6.memerr); 00288 return; 00289 } 00290 LWIP_ASSERT("check that first pbuf can hold icmp 6message", 00291 (q->len >= (sizeof(struct icmp6_hdr) + IP6_HLEN + LWIP_ICMP6_DATASIZE))); 00292 00293 icmp6hdr = (struct icmp6_hdr *)q->payload; 00294 icmp6hdr->type = type; 00295 icmp6hdr->code = code; 00296 icmp6hdr->data = data; 00297 00298 /* copy fields from original packet */ 00299 SMEMCPY((u8_t *)q->payload + sizeof(struct icmp6_hdr), (u8_t *)p->payload, 00300 IP6_HLEN + LWIP_ICMP6_DATASIZE); 00301 00302 /* Get the destination address and netif for this ICMP message. */ 00303 if ((ip_current_netif() == NULL) || 00304 ((code == ICMP6_TE_FRAG) && (type == ICMP6_TYPE_TE))) { 00305 /* Special case, as ip6_current_xxx is either NULL, or points 00306 * to a different packet than the one that expired. 00307 * We must use the addresses that are stored in the expired packet. */ 00308 ip6hdr = (struct ip6_hdr *)p->payload; 00309 /* copy from packed address to aligned address */ 00310 ip6_addr_copy(reply_dest_local, ip6hdr->src); 00311 ip6_addr_copy(reply_src_local, ip6hdr->dest); 00312 reply_dest = &reply_dest_local; 00313 reply_src = &reply_src_local; 00314 netif = ip6_route(reply_src, reply_dest); 00315 if (netif == NULL) { 00316 /* drop */ 00317 pbuf_free(q); 00318 ICMP6_STATS_INC(icmp6.rterr); 00319 return; 00320 } 00321 } 00322 else { 00323 netif = ip_current_netif(); 00324 reply_dest = ip6_current_src_addr(); 00325 00326 /* Select an address to use as source. */ 00327 reply_src = ip_2_ip6(ip6_select_source_address(netif, reply_dest)); 00328 if (reply_src == NULL) { 00329 /* drop */ 00330 pbuf_free(q); 00331 ICMP6_STATS_INC(icmp6.rterr); 00332 return; 00333 } 00334 } 00335 00336 /* calculate checksum */ 00337 icmp6hdr->chksum = 0; 00338 #if CHECKSUM_GEN_ICMP6 00339 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP6) { 00340 icmp6hdr->chksum = ip6_chksum_pseudo(q, IP6_NEXTH_ICMP6, q->tot_len, 00341 reply_src, reply_dest); 00342 } 00343 #endif /* CHECKSUM_GEN_ICMP6 */ 00344 00345 ICMP6_STATS_INC(icmp6.xmit); 00346 ip6_output_if(q, reply_src, reply_dest, LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, netif); 00347 pbuf_free(q); 00348 } 00349 00350 #endif /* LWIP_ICMP6 && LWIP_IPV6 */
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