1/** 2 * @file 3 * Implementation of raw protocol PCBs for low-level handling of 4 * different types of protocols besides (or overriding) those 5 * already available in lwIP. 6 * 7 */ 8 9/* 10 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 11 * All rights reserved. 12 * 13 * Redistribution and use in source and binary forms, with or without modification, 14 * are permitted provided that the following conditions are met: 15 * 16 * 1. Redistributions of source code must retain the above copyright notice, 17 * this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright notice, 19 * this list of conditions and the following disclaimer in the documentation 20 * and/or other materials provided with the distribution. 21 * 3. The name of the author may not be used to endorse or promote products 22 * derived from this software without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 25 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 26 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 27 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 28 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 29 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 32 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 33 * OF SUCH DAMAGE. 34 * 35 * This file is part of the lwIP TCP/IP stack. 36 * 37 * Author: Adam Dunkels <adam@sics.se> 38 * 39 */ 40 41#include "lwip/opt.h" 42 43#if LWIP_RAW /* don't build if not configured for use in lwipopts.h */ 44 45#include "lwip/def.h" 46#include "lwip/memp.h" 47#include "lwip/inet.h" 48#include "lwip/ip_addr.h" 49#include "lwip/netif.h" 50#include "lwip/raw.h" 51#include "lwip/stats.h" 52#include "lwip/snmp.h" 53#include "arch/perf.h" 54 55#include <string.h> 56 57/** The list of RAW PCBs */ 58static struct raw_pcb *raw_pcbs; 59 60/** 61 * Determine if in incoming IP packet is covered by a RAW PCB 62 * and if so, pass it to a user-provided receive callback function. 63 * 64 * Given an incoming IP datagram (as a chain of pbufs) this function 65 * finds a corresponding RAW PCB and calls the corresponding receive 66 * callback function. 67 * 68 * @param p pbuf to be demultiplexed to a RAW PCB. 69 * @param inp network interface on which the datagram was received. 70 * @return - 1 if the packet has been eaten by a RAW PCB receive 71 * callback function. The caller MAY NOT not reference the 72 * packet any longer, and MAY NOT call pbuf_free(). 73 * @return - 0 if packet is not eaten (pbuf is still referenced by the 74 * caller). 75 * 76 */ 77u8_t raw_input(struct pbuf *p, struct netif *inp) 78{ 79 struct raw_pcb *pcb, *prev; 80 struct ip_hdr *iphdr; 81 s16_t proto; 82 u8_t eaten = 0; 83 84 LWIP_UNUSED_ARG(inp); 85 86 iphdr = p->payload; 87 proto = IPH_PROTO(iphdr); 88 89 prev = NULL; 90 pcb = raw_pcbs; 91 /* loop through all raw pcbs until the packet is eaten by one */ 92 /* this allows multiple pcbs to match against the packet by design */ 93 while ((eaten == 0) && (pcb != NULL)) { 94 if (pcb->protocol == proto) { 95#if IP_SOF_BROADCAST_RECV 96 /* broadcast filter? */ 97 if ((pcb->so_options & SOF_BROADCAST) 98 || !ip_addr_isbroadcast(&(iphdr->dest), inp)) 99#endif /* IP_SOF_BROADCAST_RECV */ 100 { 101 /* receive callback function available? */ 102 if (pcb->recv != NULL) { 103 /* the receive callback function did not eat the packet? */ 104 if (pcb->recv(pcb->recv_arg, pcb, p, &(iphdr->src)) != 0) { 105 /* receive function ate the packet */ 106 p = NULL; 107 eaten = 1; 108 if (prev != NULL) { 109 /* move the pcb to the front of raw_pcbs so that is 110 found faster next time */ 111 prev->next = pcb->next; 112 pcb->next = raw_pcbs; 113 raw_pcbs = pcb; 114 } 115 } 116 } 117 /* no receive callback function was set for this raw PCB */ 118 } 119 /* drop the packet */ 120 } 121 prev = pcb; 122 pcb = pcb->next; 123 } 124 return eaten; 125} 126 127/** 128 * Bind a RAW PCB. 129 * 130 * @param pcb RAW PCB to be bound with a local address ipaddr. 131 * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to 132 * bind to all local interfaces. 133 * 134 * @return lwIP error code. 135 * - ERR_OK. Successful. No error occured. 136 * - ERR_USE. The specified IP address is already bound to by 137 * another RAW PCB. 138 * 139 * @see raw_disconnect() 140 */ 141err_t raw_bind(struct raw_pcb * pcb, struct ip_addr * ipaddr) 142{ 143 ip_addr_set(&pcb->local_ip, ipaddr); 144 return ERR_OK; 145} 146 147/** 148 * Connect an RAW PCB. This function is required by upper layers 149 * of lwip. Using the raw api you could use raw_sendto() instead 150 * 151 * This will associate the RAW PCB with the remote address. 152 * 153 * @param pcb RAW PCB to be connected with remote address ipaddr and port. 154 * @param ipaddr remote IP address to connect with. 155 * 156 * @return lwIP error code 157 * 158 * @see raw_disconnect() and raw_sendto() 159 */ 160err_t raw_connect(struct raw_pcb * pcb, struct ip_addr * ipaddr) 161{ 162 ip_addr_set(&pcb->remote_ip, ipaddr); 163 return ERR_OK; 164} 165 166 167/** 168 * Set the callback function for received packets that match the 169 * raw PCB's protocol and binding. 170 * 171 * The callback function MUST either 172 * - eat the packet by calling pbuf_free() and returning non-zero. The 173 * packet will not be passed to other raw PCBs or other protocol layers. 174 * - not free the packet, and return zero. The packet will be matched 175 * against further PCBs and/or forwarded to another protocol layers. 176 * 177 * @return non-zero if the packet was free()d, zero if the packet remains 178 * available for others. 179 */ 180void 181raw_recv(struct raw_pcb *pcb, 182 u8_t(*recv) (void *arg, struct raw_pcb * upcb, struct pbuf * p, 183 struct ip_addr * addr), void *recv_arg) 184{ 185 /* remember recv() callback and user data */ 186 pcb->recv = recv; 187 pcb->recv_arg = recv_arg; 188} 189 190/** 191 * Send the raw IP packet to the given address. Note that actually you cannot 192 * modify the IP headers (this is inconsistent with the receive callback where 193 * you actually get the IP headers), you can only specify the IP payload here. 194 * It requires some more changes in lwIP. (there will be a raw_send() function 195 * then.) 196 * 197 * @param pcb the raw pcb which to send 198 * @param p the IP payload to send 199 * @param ipaddr the destination address of the IP packet 200 * 201 */ 202err_t raw_sendto(struct raw_pcb *pcb, struct pbuf *p, struct ip_addr *ipaddr) 203{ 204 err_t err; 205 struct netif *netif; 206 struct ip_addr *src_ip; 207 struct pbuf *q; /* q will be sent down the stack */ 208 209 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | 3, ("raw_sendto\n")); 210 211 /* not enough space to add an IP header to first pbuf in given p chain? */ 212 if (pbuf_header(p, IP_HLEN)) { 213 /* allocate header in new pbuf */ 214 q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM); 215 /* new header pbuf could not be allocated? */ 216 if (q == NULL) { 217 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | 2, 218 ("raw_sendto: could not allocate header\n")); 219 return ERR_MEM; 220 } 221 /* chain header q in front of given pbuf p */ 222 pbuf_chain(q, p); 223 /* { first pbuf q points to header pbuf } */ 224 LWIP_DEBUGF(RAW_DEBUG, 225 ("raw_sendto: added header pbuf %p before given pbuf %p\n", 226 (void *) q, (void *) p)); 227 } else { 228 /* first pbuf q equals given pbuf */ 229 q = p; 230 if (pbuf_header(q, -IP_HLEN)) { 231 LWIP_ASSERT("Can't restore header we just removed!", 0); 232 return ERR_MEM; 233 } 234 } 235 236 if ((netif = ip_route(ipaddr)) == NULL) { 237 LWIP_DEBUGF(RAW_DEBUG | 1, 238 ("raw_sendto: No route to 0x%" X32_F "\n", ipaddr->addr)); 239 /* free any temporary header pbuf allocated by pbuf_header() */ 240 if (q != p) { 241 pbuf_free(q); 242 } 243 return ERR_RTE; 244 } 245#if IP_SOF_BROADCAST 246 /* broadcast filter? */ 247 if (((pcb->so_options & SOF_BROADCAST) == 0) 248 && ip_addr_isbroadcast(ipaddr, netif)) { 249 LWIP_DEBUGF(RAW_DEBUG | 1, 250 ("raw_sendto: SOF_BROADCAST not enabled on pcb %p\n", 251 (void *) pcb)); 252 /* free any temporary header pbuf allocated by pbuf_header() */ 253 if (q != p) { 254 pbuf_free(q); 255 } 256 return ERR_VAL; 257 } 258#endif /* IP_SOF_BROADCAST */ 259 260 if (ip_addr_isany(&pcb->local_ip)) { 261 /* use outgoing network interface IP address as source address */ 262 src_ip = &(netif->ip_addr); 263 } else { 264 /* use RAW PCB local IP address as source address */ 265 src_ip = &(pcb->local_ip); 266 } 267 268#if LWIP_NETIF_HWADDRHINT 269 netif->addr_hint = &(pcb->addr_hint); 270#endif /* LWIP_NETIF_HWADDRHINT */ 271 err = 272 ip_output_if(q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif); 273#if LWIP_NETIF_HWADDRHINT 274 netif->addr_hint = NULL; 275#endif /* LWIP_NETIF_HWADDRHINT */ 276 277 /* did we chain a header earlier? */ 278 if (q != p) { 279 /* free the header */ 280 pbuf_free(q); 281 } 282 return err; 283} 284 285/** 286 * Send the raw IP packet to the address given by raw_connect() 287 * 288 * @param pcb the raw pcb which to send 289 * @param p the IP payload to send 290 * 291 */ 292err_t raw_send(struct raw_pcb * pcb, struct pbuf * p) 293{ 294 return raw_sendto(pcb, p, &pcb->remote_ip); 295} 296 297/** 298 * Remove an RAW PCB. 299 * 300 * @param pcb RAW PCB to be removed. The PCB is removed from the list of 301 * RAW PCB's and the data structure is freed from memory. 302 * 303 * @see raw_new() 304 */ 305void raw_remove(struct raw_pcb *pcb) 306{ 307 struct raw_pcb *pcb2; 308 309 /* pcb to be removed is first in list? */ 310 if (raw_pcbs == pcb) { 311 /* make list start at 2nd pcb */ 312 raw_pcbs = raw_pcbs->next; 313 /* pcb not 1st in list */ 314 } else { 315 for (pcb2 = raw_pcbs; pcb2 != NULL; pcb2 = pcb2->next) { 316 /* find pcb in raw_pcbs list */ 317 if (pcb2->next != NULL && pcb2->next == pcb) { 318 /* remove pcb from list */ 319 pcb2->next = pcb->next; 320 } 321 } 322 } 323 memp_free(MEMP_RAW_PCB, pcb); 324} 325 326/** 327 * Create a RAW PCB. 328 * 329 * @return The RAW PCB which was created. NULL if the PCB data structure 330 * could not be allocated. 331 * 332 * @param proto the protocol number of the IPs payload (e.g. IP_PROTO_ICMP) 333 * 334 * @see raw_remove() 335 */ 336struct raw_pcb *raw_new(u8_t proto) 337{ 338 struct raw_pcb *pcb; 339 340 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | 3, ("raw_new\n")); 341 342 pcb = memp_malloc(MEMP_RAW_PCB); 343 /* could allocate RAW PCB? */ 344 if (pcb != NULL) { 345 /* initialize PCB to all zeroes */ 346 memset(pcb, 0, sizeof(struct raw_pcb)); 347 pcb->protocol = proto; 348 pcb->ttl = RAW_TTL; 349 pcb->next = raw_pcbs; 350 raw_pcbs = pcb; 351 } 352 return pcb; 353} 354 355#endif /* LWIP_RAW */ 356