www.pudn.com > lwip-1.3.0.rar > raw.c
/**
* @file
* Implementation of raw protocol PCBs for low-level handling of
* different types of protocols besides (or overriding) those
* already available in lwIP.
*
*/
/*
* 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
*
*/
#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/inet.h"
#include "lwip/ip_addr.h"
#include "lwip/netif.h"
#include "lwip/raw.h"
#include "lwip/stats.h"
#include "lwip/snmp.h"
#include "arch/perf.h"
#include
/** The list of RAW PCBs */
static struct raw_pcb *raw_pcbs;
/**
* Determine if in incoming IP packet is covered by a RAW PCB
* and if so, pass it to a user-provided receive callback function.
*
* Given an incoming IP datagram (as a chain of pbufs) this function
* finds a corresponding RAW PCB and calls the corresponding receive
* callback function.
*
* @param p pbuf to be demultiplexed to a RAW PCB.
* @param inp network interface on which the datagram was received.
* @return - 1 if the packet has been eaten by a RAW PCB receive
* callback function. The caller MAY NOT not reference the
* packet any longer, and MAY NOT call pbuf_free().
* @return - 0 if packet is not eaten (pbuf is still referenced by the
* caller).
*
*/
u8_t
raw_input(struct pbuf *p, struct netif *inp)
{
struct raw_pcb *pcb, *prev;
struct ip_hdr *iphdr;
s16_t proto;
u8_t eaten = 0;
LWIP_UNUSED_ARG(inp);
iphdr = p->payload;
proto = IPH_PROTO(iphdr);
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) {
/* receive callback function available? */
if (pcb->recv != NULL) {
/* the receive callback function did not eat the packet? */
if (pcb->recv(pcb->recv_arg, pcb, p, &(iphdr->src)) != 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;
}
}
}
/* no receive callback function was set for this raw PCB */
/* drop the packet */
}
prev = pcb;
pcb = pcb->next;
}
return eaten;
}
/**
* 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 IP address 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_sendto() 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_sendto()
*/
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 for received packets that match the
* raw PCB's protocol and binding.
*
* The callback function MUST either
* - eat the packet by calling pbuf_free() and returning non-zero. The
* packet will not be passed to other raw PCBs or other protocol layers.
* - not free the packet, and return zero. The packet will be matched
* against further PCBs and/or forwarded to another protocol layers.
*
* @return non-zero if the packet was free()d, zero if the packet remains
* available for others.
*/
void
raw_recv(struct raw_pcb *pcb,
u8_t (* 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 inconsistent with the receive callback where
* you actually get the IP headers), you can only specify 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 IP packet
*
*/
err_t
raw_sendto(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 | LWIP_DBG_TRACE | 3, ("raw_sendto\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 | LWIP_DBG_TRACE | 2, ("raw_sendto: 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_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, -IP_HLEN)) {
LWIP_ASSERT("Can't restore header we just removed!", 0);
return ERR_MEM;
}
}
if ((netif = ip_route(ipaddr)) == NULL) {
LWIP_DEBUGF(RAW_DEBUG | 1, ("raw_sendto: No route to 0x%"X32_F"\n", ipaddr->addr));
/* free any temporary header pbuf allocated by pbuf_header() */
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);
}
#if LWIP_NETIF_HWADDRHINT
netif->addr_hint = &(pcb->addr_hint);
#endif /* LWIP_NETIF_HWADDRHINT*/
err = ip_output_if (q, src_ip, ipaddr, pcb->ttl, pcb->tos, pcb->protocol, netif);
#if LWIP_NETIF_HWADDRHINT
netif->addr_hint = NULL;
#endif /* LWIP_NETIF_HWADDRHINT*/
/* 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
*
*/
err_t
raw_send(struct raw_pcb *pcb, struct pbuf *p)
{
return raw_sendto(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(u8_t proto) {
struct raw_pcb *pcb;
LWIP_DEBUGF(RAW_DEBUG | LWIP_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 */