lib/drivers/lwip/src/core/raw.c

   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 */
  58 static 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  */
  77 u8_t
  78 raw_input(struct pbuf *p, struct netif *inp)
  79 {
  80   struct raw_pcb *pcb, *prev;
  81   struct ip_hdr *iphdr;
  82   s16_t proto;
  83   u8_t eaten = 0;
  84
  85   LWIP_UNUSED_ARG(inp);
  86
  87   iphdr = p->payload;
  88   proto = IPH_PROTO(iphdr);
  89
  90   prev = NULL;
  91   pcb = raw_pcbs;
  92   /* loop through all raw pcbs until the packet is eaten by one */
  93   /* this allows multiple pcbs to match against the packet by design */
  94   while ((eaten == 0) && (pcb != NULL)) {
  95     if (pcb->protocol == proto) {
  96 #if IP_SOF_BROADCAST_RECV
  97       /* broadcast filter? */
  98       if ((pcb->so_options & SOF_BROADCAST) || !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  */
 141 err_t
 142 raw_bind(struct raw_pcb *pcb, struct ip_addr *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, struct ip_addr *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,
 184          u8_t (* recv)(void *arg, struct raw_pcb *upcb, struct pbuf *p,
 185                       struct ip_addr *addr),
 186          void *recv_arg)
 187 {
 188   /* remember recv() callback and user data */
 189   pcb->recv = recv;
 190   pcb->recv_arg = recv_arg;
 191 }
 192
 193 /**
 194  * Send the raw IP packet to the given address. Note that actually you cannot
 195  * modify the IP headers (this is inconsistent with the receive callback where
 196  * you actually get the IP headers), you can only specify the IP payload here.
 197  * It requires some more changes in lwIP. (there will be a raw_send() function
 198  * then.)
 199  *
 200  * @param pcb the raw pcb which to send
 201  * @param p the IP payload to send
 202  * @param ipaddr the destination address of the IP packet
 203  *
 204  */
 205 err_t
 206 raw_sendto(struct raw_pcb *pcb, struct pbuf *p, struct ip_addr *ipaddr)
 207 {
 208   err_t err;
 209   struct netif *netif;
 210   struct ip_addr *src_ip;
 211   struct pbuf *q; /* q will be sent down the stack */
 212
 213   LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_sendto\n"));
 214
 215   /* not enough space to add an IP header to first pbuf in given p chain? */
 216   if (pbuf_header(p, IP_HLEN)) {
 217     /* allocate header in new pbuf */
 218     q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM);
 219     /* new header pbuf could not be allocated? */
 220     if (q == NULL) {
 221       LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("raw_sendto: could not allocate header\n"));
 222       return ERR_MEM;
 223     }
 224     /* chain header q in front of given pbuf p */
 225     pbuf_chain(q, p);
 226     /* { first pbuf q points to header pbuf } */
 227     LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
 228   }  else {
 229     /* first pbuf q equals given pbuf */
 230     q = p;
 231     if(pbuf_header(q, -IP_HLEN)) {
 232       LWIP_ASSERT("Can't restore header we just removed!", 0);
 233       return ERR_MEM;
 234     }
 235   }
 236
 237   if ((netif = ip_route(ipaddr)) == NULL) {
 238     LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("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
 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   struct raw_pcb *pcb;
 337
 338   LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_new\n"));
 339
 340   pcb = memp_malloc(MEMP_RAW_PCB);
 341   /* could allocate RAW PCB? */
 342   if (pcb != NULL) {
 343     /* initialize PCB to all zeroes */
 344     memset(pcb, 0, sizeof(struct raw_pcb));
 345     pcb->protocol = proto;
 346     pcb->ttl = RAW_TTL;
 347     pcb->next = raw_pcbs;
 348     raw_pcbs = pcb;
 349   }
 350   return pcb;
 351 }
 352
 353 #endif /* LWIP_RAW */