FreeRTOS/Common/ethernet/lwIP_130/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       /* receive callback function available? */
  97       if (pcb->recv != NULL) {
  98         /* the receive callback function did not eat the packet? */
  99         if (pcb->recv(pcb->recv_arg, pcb, p, &(iphdr->src)) != 0)
 100         {
 101           /* receive function ate the packet */
 102           p = NULL;
 103           eaten = 1;
 104           if (prev != NULL) {
 105           /* move the pcb to the front of raw_pcbs so that is
 106              found faster next time */
 107             prev->next = pcb->next;
 108             pcb->next = raw_pcbs;
 109             raw_pcbs = pcb;
 110           }
 111         }
 112       }
 113       /* no receive callback function was set for this raw PCB */
 114       /* drop the packet */
 115     }
 116     prev = pcb;
 117     pcb = pcb->next;
 118   }
 119   return eaten;
 120 }
 121
 122 /**
 123  * Bind a RAW PCB.
 124  *
 125  * @param pcb RAW PCB to be bound with a local address ipaddr.
 126  * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to
 127  * bind to all local interfaces.
 128  *
 129  * @return lwIP error code.
 130  * - ERR_OK. Successful. No error occured.
 131  * - ERR_USE. The specified IP address is already bound to by
 132  * another RAW PCB.
 133  *
 134  * @see raw_disconnect()
 135  */
 136 err_t
 137 raw_bind(struct raw_pcb *pcb, struct ip_addr *ipaddr)
 138 {
 139   ip_addr_set(&pcb->local_ip, ipaddr);
 140   return ERR_OK;
 141 }
 142
 143 /**
 144  * Connect an RAW PCB. This function is required by upper layers
 145  * of lwip. Using the raw api you could use raw_sendto() instead
 146  *
 147  * This will associate the RAW PCB with the remote address.
 148  *
 149  * @param pcb RAW PCB to be connected with remote address ipaddr and port.
 150  * @param ipaddr remote IP address to connect with.
 151  *
 152  * @return lwIP error code
 153  *
 154  * @see raw_disconnect() and raw_sendto()
 155  */
 156 err_t
 157 raw_connect(struct raw_pcb *pcb, struct ip_addr *ipaddr)
 158 {
 159   ip_addr_set(&pcb->remote_ip, ipaddr);
 160   return ERR_OK;
 161 }
 162
 163
 164 /**
 165  * Set the callback function for received packets that match the
 166  * raw PCB's protocol and binding.
 167  *
 168  * The callback function MUST either
 169  * - eat the packet by calling pbuf_free() and returning non-zero. The
 170  *   packet will not be passed to other raw PCBs or other protocol layers.
 171  * - not free the packet, and return zero. The packet will be matched
 172  *   against further PCBs and/or forwarded to another protocol layers.
 173  *
 174  * @return non-zero if the packet was free()d, zero if the packet remains
 175  * available for others.
 176  */
 177 void
 178 raw_recv(struct raw_pcb *pcb,
 179          u8_t (* recv)(void *arg, struct raw_pcb *upcb, struct pbuf *p,
 180                       struct ip_addr *addr),
 181          void *recv_arg)
 182 {
 183   /* remember recv() callback and user data */
 184   pcb->recv = recv;
 185   pcb->recv_arg = recv_arg;
 186 }
 187
 188 /**
 189  * Send the raw IP packet to the given address. Note that actually you cannot
 190  * modify the IP headers (this is inconsistent with the receive callback where
 191  * you actually get the IP headers), you can only specify the IP payload here.
 192  * It requires some more changes in lwIP. (there will be a raw_send() function
 193  * then.)
 194  *
 195  * @param pcb the raw pcb which to send
 196  * @param p the IP payload to send
 197  * @param ipaddr the destination address of the IP packet
 198  *
 199  */
 200 err_t
 201 raw_sendto(struct raw_pcb *pcb, struct pbuf *p, struct ip_addr *ipaddr)
 202 {
 203   err_t err;
 204   struct netif *netif;
 205   struct ip_addr *src_ip;
 206   struct pbuf *q; /* q will be sent down the stack */
 207
 208   LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | 3, ("raw_sendto\n"));
 209
 210   /* not enough space to add an IP header to first pbuf in given p chain? */
 211   if (pbuf_header(p, IP_HLEN)) {
 212     /* allocate header in new pbuf */
 213     q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM);
 214     /* new header pbuf could not be allocated? */
 215     if (q == NULL) {
 216       LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | 2, ("raw_sendto: could not allocate header\n"));
 217       return ERR_MEM;
 218     }
 219     /* chain header q in front of given pbuf p */
 220     pbuf_chain(q, p);
 221     /* { first pbuf q points to header pbuf } */
 222     LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
 223   }  else {
 224     /* first pbuf q equals given pbuf */
 225     q = p;
 226     if(pbuf_header(q, -IP_HLEN)) {
 227       LWIP_ASSERT("Can't restore header we just removed!", 0);
 228       return ERR_MEM;
 229     }
 230   }
 231
 232   if ((netif = ip_route(ipaddr)) == NULL) {
 233     LWIP_DEBUGF(RAW_DEBUG | 1, ("raw_sendto: No route to 0x%"X32_F"\n", ipaddr->addr));
 234     /* free any temporary header pbuf allocated by pbuf_header() */
 235     if (q != p) {
 236       pbuf_free(q);
 237     }
 238     return ERR_RTE;
 239   }
 240
 241   if (ip_addr_isany(&pcb->local_ip)) {
 242     /* use outgoing network interface IP address as source address */
 243     src_ip = &(netif->ip_addr);
 244   } else {
 245     /* use RAW PCB local IP address as source address */
 246     src_ip = &(pcb->local_ip);
 247   }
 248
 249 #if LWIP_NETIF_HWADDRHINT
 250   netif->addr_hint = &(pcb->addr_hint);
 251 #endif /* LWIP_NETIF_HWADDRHINT*/
 252   err = ip_output_if (q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif);
 253 #if LWIP_NETIF_HWADDRHINT
 254   netif->addr_hint = NULL;
 255 #endif /* LWIP_NETIF_HWADDRHINT*/
 256
 257   /* did we chain a header earlier? */
 258   if (q != p) {
 259     /* free the header */
 260     pbuf_free(q);
 261   }
 262   return err;
 263 }
 264
 265 /**
 266  * Send the raw IP packet to the address given by raw_connect()
 267  *
 268  * @param pcb the raw pcb which to send
 269  * @param p the IP payload to send
 270  *
 271  */
 272 err_t
 273 raw_send(struct raw_pcb *pcb, struct pbuf *p)
 274 {
 275   return raw_sendto(pcb, p, &pcb->remote_ip);
 276 }
 277
 278 /**
 279  * Remove an RAW PCB.
 280  *
 281  * @param pcb RAW PCB to be removed. The PCB is removed from the list of
 282  * RAW PCB's and the data structure is freed from memory.
 283  *
 284  * @see raw_new()
 285  */
 286 void
 287 raw_remove(struct raw_pcb *pcb)
 288 {
 289   struct raw_pcb *pcb2;
 290   /* pcb to be removed is first in list? */
 291   if (raw_pcbs == pcb) {
 292     /* make list start at 2nd pcb */
 293     raw_pcbs = raw_pcbs->next;
 294     /* pcb not 1st in list */
 295   } else {
 296     for(pcb2 = raw_pcbs; pcb2 != NULL; pcb2 = pcb2->next) {
 297       /* find pcb in raw_pcbs list */
 298       if (pcb2->next != NULL && pcb2->next == pcb) {
 299         /* remove pcb from list */
 300         pcb2->next = pcb->next;
 301       }
 302     }
 303   }
 304   memp_free(MEMP_RAW_PCB, pcb);
 305 }
 306
 307 /**
 308  * Create a RAW PCB.
 309  *
 310  * @return The RAW PCB which was created. NULL if the PCB data structure
 311  * could not be allocated.
 312  *
 313  * @param proto the protocol number of the IPs payload (e.g. IP_PROTO_ICMP)
 314  *
 315  * @see raw_remove()
 316  */
 317 struct raw_pcb *
 318 raw_new(u8_t proto) {
 319   struct raw_pcb *pcb;
 320
 321   LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | 3, ("raw_new\n"));
 322
 323   pcb = memp_malloc(MEMP_RAW_PCB);
 324   /* could allocate RAW PCB? */
 325   if (pcb != NULL) {
 326     /* initialize PCB to all zeroes */
 327     memset(pcb, 0, sizeof(struct raw_pcb));
 328     pcb->protocol = proto;
 329     pcb->ttl = RAW_TTL;
 330     pcb->next = raw_pcbs;
 331     raw_pcbs = pcb;
 332   }
 333   return pcb;
 334 }
 335
 336 #endif /* LWIP_RAW */