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 (at) 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/ip_addr.h" 48 #include "lwip/netif.h" 49 #include "lwip/raw.h" 50 #include "lwip/stats.h" 51 #include "arch/perf.h" 52 53 #include <string.h> 54 55 /** The list of RAW PCBs */ 56 static struct raw_pcb *raw_pcbs; 57 58 /** 59 * Determine if in incoming IP packet is covered by a RAW PCB 60 * and if so, pass it to a user-provided receive callback function. 61 * 62 * Given an incoming IP datagram (as a chain of pbufs) this function 63 * finds a corresponding RAW PCB and calls the corresponding receive 64 * callback function. 65 * 66 * @param p pbuf to be demultiplexed to a RAW PCB. 67 * @param inp network interface on which the datagram was received. 68 * @return - 1 if the packet has been eaten by a RAW PCB receive 69 * callback function. The caller MAY NOT not reference the 70 * packet any longer, and MAY NOT call pbuf_free(). 71 * @return - 0 if packet is not eaten (pbuf is still referenced by the 72 * caller). 73 * 74 */ 75 u8_t 76 raw_input(struct pbuf *p, struct netif *inp) 77 { 78 struct raw_pcb *pcb, *prev; 79 struct ip_hdr *iphdr; 80 s16_t proto; 81 u8_t eaten = 0; 82 83 LWIP_UNUSED_ARG(inp); 84 85 iphdr = (struct ip_hdr *)p->payload; 86 proto = IPH_PROTO(iphdr); 87 88 prev = NULL; 89 pcb = raw_pcbs; 90 /* loop through all raw pcbs until the packet is eaten by one */ 91 /* this allows multiple pcbs to match against the packet by design */ 92 while ((eaten == 0) && (pcb != NULL)) { 93 if ((pcb->protocol == proto) && 94 (ip_addr_isany(&pcb->local_ip) || 95 ip_addr_cmp(&(pcb->local_ip), ¤t_iphdr_dest))) { 96 #if IP_SOF_BROADCAST_RECV 97 /* broadcast filter? */ 98 if ((pcb->so_options & SOF_BROADCAST) || !ip_addr_isbroadcast(¤t_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, ip_current_src_addr()) != 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 */ 141 err_t 142 raw_bind(struct raw_pcb *pcb, ip_addr_t *ipaddr) 143 { 144 ip_addr_set(&pcb->local_ip, ipaddr); 145 return ERR_OK; 146 } 147 148 /** 149 * Connect an RAW PCB. This function is required by upper layers 150 * of lwip. Using the raw api you could use raw_sendto() instead 151 * 152 * This will associate the RAW PCB with the remote address. 153 * 154 * @param pcb RAW PCB to be connected with remote address ipaddr and port. 155 * @param ipaddr remote IP address to connect with. 156 * 157 * @return lwIP error code 158 * 159 * @see raw_disconnect() and raw_sendto() 160 */ 161 err_t 162 raw_connect(struct raw_pcb *pcb, ip_addr_t *ipaddr) 163 { 164 ip_addr_set(&pcb->remote_ip, ipaddr); 165 return ERR_OK; 166 } 167 168 169 /** 170 * Set the callback function for received packets that match the 171 * raw PCB's protocol and binding. 172 * 173 * The callback function MUST either 174 * - eat the packet by calling pbuf_free() and returning non-zero. The 175 * packet will not be passed to other raw PCBs or other protocol layers. 176 * - not free the packet, and return zero. The packet will be matched 177 * against further PCBs and/or forwarded to another protocol layers. 178 * 179 * @return non-zero if the packet was free()d, zero if the packet remains 180 * available for others. 181 */ 182 void 183 raw_recv(struct raw_pcb *pcb, raw_recv_fn recv, 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 */ 202 err_t 203 raw_sendto(struct raw_pcb *pcb, struct pbuf *p, ip_addr_t *ipaddr) 204 { 205 err_t err; 206 struct netif *netif; 207 ip_addr_t *src_ip; 208 struct pbuf *q; /* q will be sent down the stack */ 209 210 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_sendto\n")); 211 212 /* not enough space to add an IP header to first pbuf in given p chain? */ 213 if (pbuf_header(p, IP_HLEN)) { 214 /* allocate header in new pbuf */ 215 q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM); 216 /* new header pbuf could not be allocated? */ 217 if (q == NULL) { 218 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("raw_sendto: could not allocate header\n")); 219 return ERR_MEM; 220 } 221 if (p->tot_len != 0) { 222 /* chain header q in front of given pbuf p */ 223 pbuf_chain(q, p); 224 } 225 /* { first pbuf q points to header pbuf } */ 226 LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (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 | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n", 238 ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr), ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr))); 239 /* free any temporary header pbuf allocated by pbuf_header() */ 240 if (q != p) { 241 pbuf_free(q); 242 } 243 return ERR_RTE; 244 } 245 246 #if IP_SOF_BROADCAST 247 /* broadcast filter? */ 248 if (((pcb->so_options & SOF_BROADCAST) == 0) && ip_addr_isbroadcast(ipaddr, netif)) { 249 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb)); 250 /* free any temporary header pbuf allocated by pbuf_header() */ 251 if (q != p) { 252 pbuf_free(q); 253 } 254 return ERR_VAL; 255 } 256 #endif /* IP_SOF_BROADCAST */ 257 258 if (ip_addr_isany(&pcb->local_ip)) { 259 /* use outgoing network interface IP address as source address */ 260 src_ip = &(netif->ip_addr); 261 } else { 262 /* use RAW PCB local IP address as source address */ 263 src_ip = &(pcb->local_ip); 264 } 265 266 #if LWIP_NETIF_HWADDRHINT 267 netif->addr_hint = &(pcb->addr_hint); 268 #endif /* LWIP_NETIF_HWADDRHINT*/ 269 err = ip_output_if (q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif); 270 #if LWIP_NETIF_HWADDRHINT 271 netif->addr_hint = NULL; 272 #endif /* LWIP_NETIF_HWADDRHINT*/ 273 274 /* did we chain a header earlier? */ 275 if (q != p) { 276 /* free the header */ 277 pbuf_free(q); 278 } 279 return err; 280 } 281 282 /** 283 * Send the raw IP packet to the address given by raw_connect() 284 * 285 * @param pcb the raw pcb which to send 286 * @param p the IP payload to send 287 * 288 */ 289 err_t 290 raw_send(struct raw_pcb *pcb, struct pbuf *p) 291 { 292 return raw_sendto(pcb, p, &pcb->remote_ip); 293 } 294 295 /** 296 * Remove an RAW PCB. 297 * 298 * @param pcb RAW PCB to be removed. The PCB is removed from the list of 299 * RAW PCB's and the data structure is freed from memory. 300 * 301 * @see raw_new() 302 */ 303 void 304 raw_remove(struct raw_pcb *pcb) 305 { 306 struct raw_pcb *pcb2; 307 /* pcb to be removed is first in list? */ 308 if (raw_pcbs == pcb) { 309 /* make list start at 2nd pcb */ 310 raw_pcbs = raw_pcbs->next; 311 /* pcb not 1st in list */ 312 } else { 313 for(pcb2 = raw_pcbs; pcb2 != NULL; pcb2 = pcb2->next) { 314 /* find pcb in raw_pcbs list */ 315 if (pcb2->next != NULL && pcb2->next == pcb) { 316 /* remove pcb from list */ 317 pcb2->next = pcb->next; 318 } 319 } 320 } 321 memp_free(MEMP_RAW_PCB, pcb); 322 } 323 324 /** 325 * Create a RAW PCB. 326 * 327 * @return The RAW PCB which was created. NULL if the PCB data structure 328 * could not be allocated. 329 * 330 * @param proto the protocol number of the IPs payload (e.g. IP_PROTO_ICMP) 331 * 332 * @see raw_remove() 333 */ 334 struct raw_pcb * 335 raw_new(u8_t proto) 336 { 337 struct raw_pcb *pcb; 338 339 LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_new\n")); 340 341 pcb = (struct raw_pcb *)memp_malloc(MEMP_RAW_PCB); 342 /* could allocate RAW PCB? */ 343 if (pcb != NULL) { 344 /* initialize PCB to all zeroes */ 345 memset(pcb, 0, sizeof(struct raw_pcb)); 346 pcb->protocol = proto; 347 pcb->ttl = RAW_TTL; 348 pcb->next = raw_pcbs; 349 raw_pcbs = pcb; 350 } 351 return pcb; 352 } 353 354 #endif /* LWIP_RAW */ 355