raw.c

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/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

#include "lwip/opt.h"

#if LWIP_RAW /* don't build if not configured for use in lwipopts.h */

#include "lwip/def.h"
#include "lwip/memp.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
#include "lwip/raw.h"
#include "lwip/stats.h"
#include "lwip/ip6.h"
#include "lwip/ip6_addr.h"
#include "lwip/inet_chksum.h"

#include <string.h>

static struct raw_pcb *raw_pcbs;

u8_t
raw_input(struct pbuf *p, struct netif *inp)
{
  struct raw_pcb *pcb, *prev;
  s16_t proto;
  u8_t eaten = 0;

  LWIP_UNUSED_ARG(inp);

#if LWIP_IPV6
#if LWIP_IPV4
  if (IP_HDR_GET_VERSION(p->payload) == 6)
#endif /* LWIP_IPV4 */
  {
    struct ip6_hdr *ip6hdr = (struct ip6_hdr *)p->payload;
    proto = IP6H_NEXTH(ip6hdr);
  }
#if LWIP_IPV4
  else
#endif /* LWIP_IPV4 */
#endif /* LWIP_IPV6 */
#if LWIP_IPV4
  {
    proto = IPH_PROTO((struct ip_hdr *)p->payload);
  }
#endif /* LWIP_IPV4 */

  prev = NULL;
  pcb = raw_pcbs;
  /* loop through all raw pcbs until the packet is eaten by one */
  /* this allows multiple pcbs to match against the packet by design */
  while ((eaten == 0) && (pcb != NULL)) {
    if ((pcb->protocol == proto) && IP_PCB_IPVER_INPUT_MATCH(pcb) &&
        (ip_addr_isany(&pcb->local_ip) ||
         ip_addr_cmp(&pcb->local_ip, ip_current_dest_addr()))) {
#if IP_SOF_BROADCAST_RECV
      /* broadcast filter? */
      if ((ip_get_option(pcb, SOF_BROADCAST) || !ip_addr_isbroadcast(ip_current_dest_addr(), ip_current_netif()))
          || PCB_ISIPV6(pcb)
          )
#endif /* IP_SOF_BROADCAST_RECV */
      {
        /* receive callback function available? */
        if (pcb->recv != NULL) {
#ifndef LWIP_NOASSERT
          void* old_payload = p->payload;
#endif
          /* the receive callback function did not eat the packet? */
          eaten = pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr());
          if (eaten != 0) {
            /* receive function ate the packet */
            p = NULL;
            eaten = 1;
            if (prev != NULL) {
            /* move the pcb to the front of raw_pcbs so that is
               found faster next time */
              prev->next = pcb->next;
              pcb->next = raw_pcbs;
              raw_pcbs = pcb;
            }
          } else {
            /* sanity-check that the receive callback did not alter the pbuf */
            LWIP_ASSERT("raw pcb recv callback altered pbuf payload pointer without eating packet",
              p->payload == old_payload);
          }
        }
        /* no receive callback function was set for this raw PCB */
      }
      /* drop the packet */
    }
    prev = pcb;
    pcb = pcb->next;
  }
  return eaten;
}

err_t
raw_bind(struct raw_pcb *pcb, const ip_addr_t *ipaddr)
{
  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
    return ERR_VAL;
  }
  ip_addr_set_ipaddr(&pcb->local_ip, ipaddr);
  return ERR_OK;
}

err_t
raw_connect(struct raw_pcb *pcb, const ip_addr_t *ipaddr)
{
  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
    return ERR_VAL;
  }
  ip_addr_set_ipaddr(&pcb->remote_ip, ipaddr);
  return ERR_OK;
}

void
raw_recv(struct raw_pcb *pcb, raw_recv_fn recv, void *recv_arg)
{
  /* remember recv() callback and user data */
  pcb->recv = recv;
  pcb->recv_arg = recv_arg;
}

err_t
raw_sendto(struct raw_pcb *pcb, struct pbuf *p, const ip_addr_t *ipaddr)
{
  err_t err;
  struct netif *netif;
  const ip_addr_t *src_ip;
  struct pbuf *q; /* q will be sent down the stack */
  s16_t header_size;
  const ip_addr_t *dst_ip = ipaddr;

  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
    return ERR_VAL;
  }

  LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_sendto\n"));

  header_size = (
#if LWIP_IPV4 && LWIP_IPV6
    PCB_ISIPV6(pcb) ? IP6_HLEN : IP_HLEN);
#elif LWIP_IPV4
    IP_HLEN);
#else
    IP6_HLEN);
#endif

  /* not enough space to add an IP header to first pbuf in given p chain? */
  if (pbuf_header(p, header_size)) {
    /* allocate header in new pbuf */
    q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM);
    /* new header pbuf could not be allocated? */
    if (q == NULL) {
      LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("raw_sendto: could not allocate header\n"));
      return ERR_MEM;
    }
    if (p->tot_len != 0) {
      /* chain header q in front of given pbuf p */
      pbuf_chain(q, p);
    }
    /* { first pbuf q points to header pbuf } */
    LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
  } else {
    /* first pbuf q equals given pbuf */
    q = p;
    if (pbuf_header(q, -header_size)) {
      LWIP_ASSERT("Can't restore header we just removed!", 0);
      return ERR_MEM;
    }
  }

  netif = ip_route(PCB_ISIPV6(pcb), &pcb->local_ip, dst_ip);
  if (netif == NULL) {
    LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: No route to "));
    ip_addr_debug_print(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, dst_ip);
    /* free any temporary header pbuf allocated by pbuf_header() */
    if (q != p) {
      pbuf_free(q);
    }
    return ERR_RTE;
  }

#if IP_SOF_BROADCAST
  if (!PCB_ISIPV6(pcb))
  {
    /* broadcast filter? */
    if (!ip_get_option(pcb, SOF_BROADCAST) && ip_addr_isbroadcast(ipaddr, netif)) {
      LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb));
      /* free any temporary header pbuf allocated by pbuf_header() */
      if (q != p) {
        pbuf_free(q);
      }
      return ERR_VAL;
    }
  }
#endif /* IP_SOF_BROADCAST */

  if (ip_addr_isany(&pcb->local_ip)) {
    /* use outgoing network interface IP address as source address */
    src_ip = ip_netif_get_local_ip(PCB_ISIPV6(pcb), netif, dst_ip);
#if LWIP_IPV6
    if (src_ip == NULL) {
      if (q != p) {
        pbuf_free(q);
      }
      return ERR_RTE;
    }
#endif /* LWIP_IPV6 */
  } else {
    /* use RAW PCB local IP address as source address */
    src_ip = &pcb->local_ip;
  }

#if LWIP_IPV6
  /* If requested, based on the IPV6_CHECKSUM socket option per RFC3542,
     compute the checksum and update the checksum in the payload. */
  if (PCB_ISIPV6(pcb) && pcb->chksum_reqd) {
    u16_t chksum = ip6_chksum_pseudo(p, pcb->protocol, p->tot_len, ip_2_ip6(src_ip), ip_2_ip6(dst_ip));
    LWIP_ASSERT("Checksum must fit into first pbuf", p->len >= (pcb->chksum_offset + 2));
    SMEMCPY(((u8_t *)p->payload) + pcb->chksum_offset, &chksum, sizeof(u16_t));
  }
#endif

  NETIF_SET_HWADDRHINT(netif, &pcb->addr_hint);
  err = ip_output_if(PCB_ISIPV6(pcb), q, src_ip, dst_ip, pcb->ttl, pcb->tos, pcb->protocol, netif);
  NETIF_SET_HWADDRHINT(netif, NULL);

  /* did we chain a header earlier? */
  if (q != p) {
    /* free the header */
    pbuf_free(q);
  }
  return err;
}

err_t
raw_send(struct raw_pcb *pcb, struct pbuf *p)
{
  return raw_sendto(pcb, p, &pcb->remote_ip);
}

void
raw_remove(struct raw_pcb *pcb)
{
  struct raw_pcb *pcb2;
  /* pcb to be removed is first in list? */
  if (raw_pcbs == pcb) {
    /* make list start at 2nd pcb */
    raw_pcbs = raw_pcbs->next;
    /* pcb not 1st in list */
  } else {
    for (pcb2 = raw_pcbs; pcb2 != NULL; pcb2 = pcb2->next) {
      /* find pcb in raw_pcbs list */
      if (pcb2->next != NULL && pcb2->next == pcb) {
        /* remove pcb from list */
        pcb2->next = pcb->next;
        break;
      }
    }
  }
  memp_free(MEMP_RAW_PCB, pcb);
}

struct raw_pcb *
raw_new(u8_t proto)
{
  struct raw_pcb *pcb;

  LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_new\n"));

  pcb = (struct raw_pcb *)memp_malloc(MEMP_RAW_PCB);
  /* could allocate RAW PCB? */
  if (pcb != NULL) {
    /* initialize PCB to all zeroes */
    memset(pcb, 0, sizeof(struct raw_pcb));
    pcb->protocol = proto;
    pcb->ttl = RAW_TTL;
    pcb->next = raw_pcbs;
    raw_pcbs = pcb;
  }
  return pcb;
}

#if LWIP_IPV6

struct raw_pcb *
raw_new_ip6(u8_t proto)
{
  struct raw_pcb *pcb;
  pcb = raw_new(proto);
#if LWIP_IPV4
  ip_set_v6(pcb, 1);
#endif /* LWIP_IPV4 */
  return pcb;
}
#endif /* LWIP_IPV6 */

#endif /* LWIP_RAW */