FreeRTOS/Common/ethernet/lwIP/core/raw.c

   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 */