lwip/src/core/raw.c

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2003-11-14 13:17:23 +00:00
/**
* @file
* Raw Access module
*
*/
/*
* Copyright (c) 2001-2003 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>
*
*/
/* raw.c
*
* The code for the Raw Access to the IP
*
*/
#include "lwip/opt.h"
#include "lwip/def.h"
#include "lwip/memp.h"
#include "lwip/inet.h"
#include "lwip/netif.h"
#include "lwip/ip_addr.h"
#include "lwip/raw.h"
#include "lwip/stats.h"
#include "arch/perf.h"
#include "lwip/snmp.h"
#if LWIP_RAW
/* The list of RAW PCBs */
static struct raw_pcb *raw_pcbs = NULL;
void
raw_init(void)
{
raw_pcbs = NULL;
}
/**
* Determine if in incoming IP packet is covered by a RAW pcb and
* and process it if possible
*
* Given an incoming IP datagram (as a chain of pbufs) this function
* finds a corresponding RAW PCB and
*
* @param pbuf pbuf to be demultiplexed to a RAW PCB.
* @param netif network interface on which the datagram was received.
* @return 0 if packet is not eated (pbuf needs to be freed then)
* or 1 if the packet has been eaten (pbuf needs not to be freed
* then)
*
*/
int
raw_input(struct pbuf *p, struct netif *inp)
{
struct raw_pcb *pcb;
struct ip_hdr *iphdr;
int proto;
int rc = 0;
iphdr = p->payload;
proto = IPH_PROTO(iphdr);
for(pcb = raw_pcbs; pcb != NULL; pcb = pcb->next) {
if (pcb->protocol == proto) {
if (pcb->recv) {
if (!pcb->recv(pcb->recv_arg, pcb, p, &(iphdr->src)))
return 0;
}
pbuf_free(p);
rc = 1;
break;
}
}
return rc;
}
/**
* Bind a RAW PCB.
*
* @param pcb RAW PCB to be bound with a local address ipaddr.
* @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to
* bind to all local interfaces.
*
* @return lwIP error code.
* - ERR_OK. Successful. No error occured.
* - ERR_USE. The specified ipaddr is already bound to by
* another RAW PCB.
*
* @see raw_disconnect()
*/
err_t
raw_bind(struct raw_pcb *pcb, struct ip_addr *ipaddr)
{
ip_addr_set(&pcb->local_ip, ipaddr);
return ERR_OK;
}
/**
* Connect an RAW PCB. This function is required by upper layers
* of lwip. Using the raw api you could use raw_send_to() instead
*
* This will associate the RAW PCB with the remote address.
*
* @param pcb RAW PCB to be connected with remote address ipaddr and port.
* @param ipaddr remote IP address to connect with.
*
* @return lwIP error code
*
* @see raw_disconnect() and raw_send_to()
*/
err_t
raw_connect(struct raw_pcb *pcb, struct ip_addr *ipaddr)
{
ip_addr_set(&pcb->remote_ip, ipaddr);
return ERR_OK;
}
/**
* Set the callback function if a RAW packet with the pcb's protocol
* is received. If the callback function returns a value unequal 0
* the raw packet is "eaten" and not forwarded to any other raw pcb
* including lwip itself
*/
void
raw_recv(struct raw_pcb *pcb,
int (* recv)(void *arg, struct raw_pcb *upcb, struct pbuf *p,
struct ip_addr *addr),
void *recv_arg)
{
/* remember recv() callback and user data */
pcb->recv = recv;
pcb->recv_arg = recv_arg;
}
/**
* Send the raw IP packet to the given address. Note that actually you cannot
* modify the IP headers (this is inconsitent with the receive callback where
* you actually get the IP headers), you can only specifiy the ip payload here.
* It requires some more changes in LWIP. (there will be a raw_send() function
* then)
*
* @param pcb the raw pcb which to send
* @param p the ip payload to send
* @param ipaddr the destination address of the whole IP packet
*
*/
err_t
raw_send_to(struct raw_pcb *pcb, struct pbuf *p, struct ip_addr *ipaddr)
{
err_t err;
struct netif *netif;
struct ip_addr *src_ip;
struct pbuf *q; /* q will be sent down the stack */
LWIP_DEBUGF(RAW_DEBUG | DBG_TRACE | 3, ("raw_send_to\n"));
/* not enough space to add an IP header to first pbuf in given p chain? */
if (pbuf_header(p, IP_HLEN)) {
/* 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 | DBG_TRACE | 2, ("raw_send_to: could not allocate header\n"));
return ERR_MEM;
}
/* 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_send_to: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
} else {
/* first pbuf q equals given pbuf */
q = p;
pbuf_header(q, -IP_HLEN);
}
if ((netif = ip_route(ipaddr)) == NULL) {
LWIP_DEBUGF(RAW_DEBUG | 1, ("raw_send_to: No route to 0x%lx\n", ipaddr->addr));
#if RAW_STATS
/* ++lwip_stats.raw.rterr;*/
#endif /* RAW_STATS */
if (q != p) {
pbuf_free(q);
}
return ERR_RTE;
}
if (ip_addr_isany(&pcb->local_ip)) {
/* use outgoing network interface IP address as source address */
src_ip = &(netif->ip_addr);
} else {
/* use RAW PCB local IP address as source address */
src_ip = &(pcb->local_ip);
}
err = ip_output_if (q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif);
/* did we chain a header earlier? */
if (q != p) {
/* free the header */
pbuf_free(q);
}
return err;
}
/**
* Send the raw IP packet to the address given by raw_connect()
*
* @param pcb the raw pcb which to send
* @param p the ip payload to send
* @param ipaddr the destination address of the whole IP packet
*
*/
err_t
raw_send(struct raw_pcb *pcb, struct pbuf *p)
{
return raw_send_to(pcb,p,&pcb->remote_ip);
}
/**
* Remove an RAW PCB.
*
* @param pcb RAW PCB to be removed. The PCB is removed from the list of
* RAW PCB's and the data structure is freed from memory.
*
* @see raw_new()
*/
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;
}
}
memp_free(MEMP_RAW_PCB, pcb);
}
/**
* Create a RAW PCB.
*
* @return The RAW PCB which was created. NULL if the PCB data structure
* could not be allocated.
*
* @param proto the protocol number of the IPs payload (e.g. IP_PROTO_ICMP)
*
* @see raw_remove()
*/
struct raw_pcb *
raw_new(u16_t proto) {
struct raw_pcb *pcb;
LWIP_DEBUGF(RAW_DEBUG | DBG_TRACE | 3, ("raw_new\n"));
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;
}
#endif /* LWIP_RAW */