Travis Geiselbrecht | 1d0df69 | 2008-09-01 02:26:09 -0700 | [diff] [blame^] | 1 | /** |
| 2 | * @file |
| 3 | * |
| 4 | * Implementation of raw protocol PCBs for low-level handling of |
| 5 | * different types of protocols besides (or overriding) those |
| 6 | * already available in lwIP. |
| 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 <string.h> |
| 42 | |
| 43 | #include "lwip/opt.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 | |
| 52 | #include "lwip/stats.h" |
| 53 | |
| 54 | #include "arch/perf.h" |
| 55 | #include "lwip/snmp.h" |
| 56 | |
| 57 | #if LWIP_RAW |
| 58 | |
| 59 | /** The list of RAW PCBs */ |
| 60 | static struct raw_pcb *raw_pcbs = NULL; |
| 61 | |
| 62 | void |
| 63 | raw_init(void) |
| 64 | { |
| 65 | raw_pcbs = NULL; |
| 66 | } |
| 67 | |
| 68 | /** |
| 69 | * Determine if in incoming IP packet is covered by a RAW PCB |
| 70 | * and if so, pass it to a user-provided receive callback function. |
| 71 | * |
| 72 | * Given an incoming IP datagram (as a chain of pbufs) this function |
| 73 | * finds a corresponding RAW PCB and calls the corresponding receive |
| 74 | * callback function. |
| 75 | * |
| 76 | * @param pbuf pbuf to be demultiplexed to a RAW PCB. |
| 77 | * @param netif network interface on which the datagram was received. |
| 78 | * @Return - 1 if the packet has been eaten by a RAW PCB receive |
| 79 | * callback function. The caller MAY NOT not reference the |
| 80 | * packet any longer, and MAY NOT call pbuf_free(). |
| 81 | * @return - 0 if packet is not eaten (pbuf is still referenced by the |
| 82 | * caller). |
| 83 | * |
| 84 | */ |
| 85 | u8_t |
| 86 | raw_input(struct pbuf *p, struct netif *inp) |
| 87 | { |
| 88 | struct raw_pcb *pcb; |
| 89 | struct ip_hdr *iphdr; |
| 90 | s16_t proto; |
| 91 | u8_t eaten = 0; |
| 92 | |
| 93 | iphdr = p->payload; |
| 94 | proto = IPH_PROTO(iphdr); |
| 95 | |
| 96 | pcb = raw_pcbs; |
| 97 | /* loop through all raw pcbs until the packet is eaten by one */ |
| 98 | /* this allows multiple pcbs to match against the packet by design */ |
| 99 | while ((eaten == 0) && (pcb != NULL)) { |
| 100 | if (pcb->protocol == proto) { |
| 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 | { |
| 106 | /* receive function ate the packet */ |
| 107 | p = NULL; |
| 108 | eaten = 1; |
| 109 | } |
| 110 | } |
| 111 | /* no receive callback function was set for this raw PCB */ |
| 112 | /* drop the packet */ |
| 113 | } |
| 114 | pcb = pcb->next; |
| 115 | } |
| 116 | return eaten; |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * Bind a RAW PCB. |
| 121 | * |
| 122 | * @param pcb RAW PCB to be bound with a local address ipaddr. |
| 123 | * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to |
| 124 | * bind to all local interfaces. |
| 125 | * |
| 126 | * @return lwIP error code. |
| 127 | * - ERR_OK. Successful. No error occured. |
| 128 | * - ERR_USE. The specified IP address is already bound to by |
| 129 | * another RAW PCB. |
| 130 | * |
| 131 | * @see raw_disconnect() |
| 132 | */ |
| 133 | err_t |
| 134 | raw_bind(struct raw_pcb *pcb, struct ip_addr *ipaddr) |
| 135 | { |
| 136 | ip_addr_set(&pcb->local_ip, ipaddr); |
| 137 | return ERR_OK; |
| 138 | } |
| 139 | |
| 140 | /** |
| 141 | * Connect an RAW PCB. This function is required by upper layers |
| 142 | * of lwip. Using the raw api you could use raw_sendto() instead |
| 143 | * |
| 144 | * This will associate the RAW PCB with the remote address. |
| 145 | * |
| 146 | * @param pcb RAW PCB to be connected with remote address ipaddr and port. |
| 147 | * @param ipaddr remote IP address to connect with. |
| 148 | * |
| 149 | * @return lwIP error code |
| 150 | * |
| 151 | * @see raw_disconnect() and raw_sendto() |
| 152 | */ |
| 153 | err_t |
| 154 | raw_connect(struct raw_pcb *pcb, struct ip_addr *ipaddr) |
| 155 | { |
| 156 | ip_addr_set(&pcb->remote_ip, ipaddr); |
| 157 | return ERR_OK; |
| 158 | } |
| 159 | |
| 160 | |
| 161 | /** |
| 162 | * Set the callback function for received packets that match the |
| 163 | * raw PCB's protocol and binding. |
| 164 | * |
| 165 | * The callback function MUST either |
| 166 | * - eat the packet by calling pbuf_free() and returning non-zero. The |
| 167 | * packet will not be passed to other raw PCBs or other protocol layers. |
| 168 | * - not free the packet, and return zero. The packet will be matched |
| 169 | * against further PCBs and/or forwarded to another protocol layers. |
| 170 | * |
| 171 | * @return non-zero if the packet was free()d, zero if the packet remains |
| 172 | * available for others. |
| 173 | */ |
| 174 | void |
| 175 | raw_recv(struct raw_pcb *pcb, |
| 176 | u8_t (* recv)(void *arg, struct raw_pcb *upcb, struct pbuf *p, |
| 177 | struct ip_addr *addr), |
| 178 | void *recv_arg) |
| 179 | { |
| 180 | /* remember recv() callback and user data */ |
| 181 | pcb->recv = recv; |
| 182 | pcb->recv_arg = recv_arg; |
| 183 | } |
| 184 | |
| 185 | /** |
| 186 | * Send the raw IP packet to the given address. Note that actually you cannot |
| 187 | * modify the IP headers (this is inconsistent with the receive callback where |
| 188 | * you actually get the IP headers), you can only specify the IP payload here. |
| 189 | * It requires some more changes in lwIP. (there will be a raw_send() function |
| 190 | * then.) |
| 191 | * |
| 192 | * @param pcb the raw pcb which to send |
| 193 | * @param p the IP payload to send |
| 194 | * @param ipaddr the destination address of the IP packet |
| 195 | * |
| 196 | */ |
| 197 | err_t |
| 198 | raw_sendto(struct raw_pcb *pcb, struct pbuf *p, struct ip_addr *ipaddr) |
| 199 | { |
| 200 | err_t err; |
| 201 | struct netif *netif; |
| 202 | struct ip_addr *src_ip; |
| 203 | struct pbuf *q; /* q will be sent down the stack */ |
| 204 | |
| 205 | LWIP_DEBUGF(RAW_DEBUG | DBG_TRACE | 3, ("raw_sendto\n")); |
| 206 | |
| 207 | /* not enough space to add an IP header to first pbuf in given p chain? */ |
| 208 | if (pbuf_header(p, IP_HLEN)) { |
| 209 | /* allocate header in new pbuf */ |
| 210 | q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM); |
| 211 | /* new header pbuf could not be allocated? */ |
| 212 | if (q == NULL) { |
| 213 | LWIP_DEBUGF(RAW_DEBUG | DBG_TRACE | 2, ("raw_sendto: could not allocate header\n")); |
| 214 | return ERR_MEM; |
| 215 | } |
| 216 | /* chain header q in front of given pbuf p */ |
| 217 | pbuf_chain(q, p); |
| 218 | /* { first pbuf q points to header pbuf } */ |
| 219 | LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p)); |
| 220 | } else { |
| 221 | /* first pbuf q equals given pbuf */ |
| 222 | q = p; |
| 223 | pbuf_header(q, -IP_HLEN); |
| 224 | } |
| 225 | |
| 226 | if ((netif = ip_route(ipaddr)) == NULL) { |
| 227 | LWIP_DEBUGF(RAW_DEBUG | 1, ("raw_sendto: No route to 0x%"X32_F"\n", ipaddr->addr)); |
| 228 | #if RAW_STATS |
| 229 | /* ++lwip_stats.raw.rterr;*/ |
| 230 | #endif /* RAW_STATS */ |
| 231 | /* free any temporary header pbuf allocated by pbuf_header() */ |
| 232 | if (q != p) { |
| 233 | pbuf_free(q); |
| 234 | } |
| 235 | return ERR_RTE; |
| 236 | } |
| 237 | |
| 238 | if (ip_addr_isany(&pcb->local_ip)) { |
| 239 | /* use outgoing network interface IP address as source address */ |
| 240 | src_ip = &(netif->ip_addr); |
| 241 | } else { |
| 242 | /* use RAW PCB local IP address as source address */ |
| 243 | src_ip = &(pcb->local_ip); |
| 244 | } |
| 245 | |
| 246 | err = ip_output_if (q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif); |
| 247 | |
| 248 | /* did we chain a header earlier? */ |
| 249 | if (q != p) { |
| 250 | /* free the header */ |
| 251 | pbuf_free(q); |
| 252 | } |
| 253 | return err; |
| 254 | } |
| 255 | |
| 256 | /** |
| 257 | * Send the raw IP packet to the address given by raw_connect() |
| 258 | * |
| 259 | * @param pcb the raw pcb which to send |
| 260 | * @param p the IP payload to send |
| 261 | * @param ipaddr the destination address of the IP packet |
| 262 | * |
| 263 | */ |
| 264 | err_t |
| 265 | raw_send(struct raw_pcb *pcb, struct pbuf *p) |
| 266 | { |
| 267 | return raw_sendto(pcb, p, &pcb->remote_ip); |
| 268 | } |
| 269 | |
| 270 | /** |
| 271 | * Remove an RAW PCB. |
| 272 | * |
| 273 | * @param pcb RAW PCB to be removed. The PCB is removed from the list of |
| 274 | * RAW PCB's and the data structure is freed from memory. |
| 275 | * |
| 276 | * @see raw_new() |
| 277 | */ |
| 278 | void |
| 279 | raw_remove(struct raw_pcb *pcb) |
| 280 | { |
| 281 | struct raw_pcb *pcb2; |
| 282 | /* pcb to be removed is first in list? */ |
| 283 | if (raw_pcbs == pcb) { |
| 284 | /* make list start at 2nd pcb */ |
| 285 | raw_pcbs = raw_pcbs->next; |
| 286 | /* pcb not 1st in list */ |
| 287 | } else for(pcb2 = raw_pcbs; pcb2 != NULL; pcb2 = pcb2->next) { |
| 288 | /* find pcb in raw_pcbs list */ |
| 289 | if (pcb2->next != NULL && pcb2->next == pcb) { |
| 290 | /* remove pcb from list */ |
| 291 | pcb2->next = pcb->next; |
| 292 | } |
| 293 | } |
| 294 | memp_free(MEMP_RAW_PCB, pcb); |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * Create a RAW PCB. |
| 299 | * |
| 300 | * @return The RAW PCB which was created. NULL if the PCB data structure |
| 301 | * could not be allocated. |
| 302 | * |
| 303 | * @param proto the protocol number of the IPs payload (e.g. IP_PROTO_ICMP) |
| 304 | * |
| 305 | * @see raw_remove() |
| 306 | */ |
| 307 | struct raw_pcb * |
| 308 | raw_new(u16_t proto) { |
| 309 | struct raw_pcb *pcb; |
| 310 | |
| 311 | LWIP_DEBUGF(RAW_DEBUG | DBG_TRACE | 3, ("raw_new\n")); |
| 312 | |
| 313 | pcb = memp_malloc(MEMP_RAW_PCB); |
| 314 | /* could allocate RAW PCB? */ |
| 315 | if (pcb != NULL) { |
| 316 | /* initialize PCB to all zeroes */ |
| 317 | memset(pcb, 0, sizeof(struct raw_pcb)); |
| 318 | pcb->protocol = proto; |
| 319 | pcb->ttl = RAW_TTL; |
| 320 | pcb->next = raw_pcbs; |
| 321 | raw_pcbs = pcb; |
| 322 | } |
| 323 | return pcb; |
| 324 | } |
| 325 | |
| 326 | #endif /* LWIP_RAW */ |