542 lines
14 KiB
C
542 lines
14 KiB
C
/*
|
|
* Copyright (c) 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. Neither the name of the Institute nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 Contiki operating system.
|
|
*
|
|
* Author: Adam Dunkels <adam@sics.se>
|
|
*
|
|
* $Id: uip-fw.c,v 1.8 2007/11/17 10:46:58 adamdunkels Exp $
|
|
*/
|
|
/**
|
|
* \addtogroup uip
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* \defgroup uipfw uIP packet forwarding
|
|
* @{
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* uIP packet forwarding.
|
|
* \author Adam Dunkels <adam@sics.se>
|
|
*
|
|
* This file implements a number of simple functions which do packet
|
|
* forwarding over multiple network interfaces with uIP.
|
|
*
|
|
*/
|
|
|
|
#include <string.h>
|
|
|
|
#include "contiki-conf.h"
|
|
|
|
#include "net/uip.h"
|
|
#include "net/uip_arch.h"
|
|
#include "net/uip-fw.h"
|
|
#ifdef AODV_COMPLIANCE
|
|
#include "net/uaodv-def.h"
|
|
#endif
|
|
|
|
/*
|
|
* The list of registered network interfaces.
|
|
*/
|
|
static struct uip_fw_netif *netifs = NULL;
|
|
|
|
/*
|
|
* A pointer to the default network interface.
|
|
*/
|
|
static struct uip_fw_netif *defaultnetif = NULL;
|
|
|
|
struct tcpip_hdr {
|
|
/* IP header. */
|
|
u8_t vhl,
|
|
tos;
|
|
u16_t len,
|
|
ipid,
|
|
ipoffset;
|
|
u8_t ttl,
|
|
proto;
|
|
u16_t ipchksum;
|
|
uip_ipaddr_t srcipaddr, destipaddr;
|
|
|
|
/* TCP header. */
|
|
u16_t srcport,
|
|
destport;
|
|
u8_t seqno[4],
|
|
ackno[4],
|
|
tcpoffset,
|
|
flags,
|
|
wnd[2];
|
|
u16_t tcpchksum;
|
|
u8_t urgp[2];
|
|
u8_t optdata[4];
|
|
};
|
|
|
|
struct icmpip_hdr {
|
|
/* IP header. */
|
|
u8_t vhl,
|
|
tos,
|
|
len[2],
|
|
ipid[2],
|
|
ipoffset[2],
|
|
ttl,
|
|
proto;
|
|
u16_t ipchksum;
|
|
uip_ipaddr_t srcipaddr, destipaddr;
|
|
/* ICMP (echo) header. */
|
|
u8_t type, icode;
|
|
u16_t icmpchksum;
|
|
u16_t id, seqno;
|
|
u8_t payload[1];
|
|
};
|
|
|
|
/* ICMP ECHO. */
|
|
#define ICMP_ECHO 8
|
|
|
|
/* ICMP TIME-EXCEEDED. */
|
|
#define ICMP_TE 11
|
|
|
|
/*
|
|
* Pointer to the TCP/IP headers of the packet in the uip_buf buffer.
|
|
*/
|
|
#define BUF ((struct tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
|
|
|
|
/*
|
|
* Pointer to the ICMP/IP headers of the packet in the uip_buf buffer.
|
|
*/
|
|
#define ICMPBUF ((struct icmpip_hdr *)&uip_buf[UIP_LLH_LEN])
|
|
|
|
/*
|
|
* Certain fields of an IP packet that are used for identifying
|
|
* duplicate packets.
|
|
*/
|
|
struct fwcache_entry {
|
|
u16_t timer;
|
|
|
|
uip_ipaddr_t srcipaddr;
|
|
uip_ipaddr_t destipaddr;
|
|
u16_t ipid;
|
|
u8_t proto;
|
|
u8_t unused;
|
|
|
|
#if notdef
|
|
u16_t payload[2];
|
|
#endif
|
|
|
|
#if UIP_REASSEMBLY > 0
|
|
u16_t len, offset;
|
|
#endif
|
|
};
|
|
|
|
/*
|
|
* The number of packets to remember when looking for duplicates.
|
|
*/
|
|
#ifdef UIP_CONF_FWCACHE_SIZE
|
|
#define FWCACHE_SIZE UIP_CONF_FWCACHE_SIZE
|
|
#else
|
|
#define FWCACHE_SIZE 2
|
|
#endif
|
|
|
|
|
|
/*
|
|
* A cache of packet header fields which are used for
|
|
* identifying duplicate packets.
|
|
*/
|
|
static struct fwcache_entry fwcache[FWCACHE_SIZE];
|
|
|
|
/**
|
|
* \internal
|
|
* The time that a packet cache is active.
|
|
*/
|
|
#define FW_TIME 20
|
|
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* Initialize the uIP packet forwarding module.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
void
|
|
uip_fw_init(void)
|
|
{
|
|
struct uip_fw_netif *t;
|
|
defaultnetif = NULL;
|
|
while(netifs != NULL) {
|
|
t = netifs;
|
|
netifs = netifs->next;
|
|
t->next = NULL;
|
|
}
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* \internal
|
|
* Check if an IP address is within the network defined by an IP
|
|
* address and a netmask.
|
|
*
|
|
* \param ipaddr The IP address to be checked.
|
|
* \param netipaddr The IP address of the network.
|
|
* \param netmask The netmask of the network.
|
|
*
|
|
* \return Non-zero if IP address is in network, zero otherwise.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
static unsigned char
|
|
ipaddr_maskcmp(uip_ipaddr_t *ipaddr,
|
|
uip_ipaddr_t *netipaddr,
|
|
uip_ipaddr_t *netmask)
|
|
{
|
|
return (ipaddr->u16[0] & netmask->u16[0]) == (netipaddr->u16[0] & netmask->u16[0]) &&
|
|
(ipaddr->u16[1] & netmask->u16[1]) == (netipaddr->u16[1] & netmask->u16[1]);
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* \internal
|
|
* Send out an ICMP TIME-EXCEEDED message.
|
|
*
|
|
* This function replaces the packet in the uip_buf buffer with the
|
|
* ICMP packet.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
static void
|
|
time_exceeded(void)
|
|
{
|
|
uip_ipaddr_t tmpip;
|
|
|
|
/* We don't send out ICMP errors for ICMP messages. */
|
|
if(ICMPBUF->proto == UIP_PROTO_ICMP) {
|
|
uip_len = 0;
|
|
return;
|
|
}
|
|
/* Copy fields from packet header into payload of this ICMP packet. */
|
|
memcpy(&(ICMPBUF->payload[0]), ICMPBUF, 28);
|
|
|
|
/* Set the ICMP type and code. */
|
|
ICMPBUF->type = ICMP_TE;
|
|
ICMPBUF->icode = 0;
|
|
|
|
/* Calculate the ICMP checksum. */
|
|
ICMPBUF->icmpchksum = 0;
|
|
ICMPBUF->icmpchksum = ~uip_chksum((u16_t *)&(ICMPBUF->type), 36);
|
|
|
|
/* Set the IP destination address to be the source address of the
|
|
original packet. */
|
|
uip_ipaddr_copy(&tmpip, &BUF->destipaddr);
|
|
uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr);
|
|
uip_ipaddr_copy(&BUF->srcipaddr, &tmpip);
|
|
uip_ipaddr_copy(&tmpip, &BUF->destipaddr);
|
|
uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr);
|
|
uip_ipaddr_copy(&BUF->srcipaddr, &tmpip);
|
|
|
|
/* Set our IP address as the source address. */
|
|
uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr);
|
|
|
|
/* The size of the ICMP time exceeded packet is 36 + the size of the
|
|
IP header (20) = 56. */
|
|
uip_len = 56;
|
|
ICMPBUF->len[0] = 0;
|
|
ICMPBUF->len[1] = (u8_t)uip_len;
|
|
|
|
/* Fill in the other fields in the IP header. */
|
|
ICMPBUF->vhl = 0x45;
|
|
ICMPBUF->tos = 0;
|
|
ICMPBUF->ipoffset[0] = ICMPBUF->ipoffset[1] = 0;
|
|
ICMPBUF->ttl = UIP_TTL;
|
|
ICMPBUF->proto = UIP_PROTO_ICMP;
|
|
|
|
/* Calculate IP checksum. */
|
|
ICMPBUF->ipchksum = 0;
|
|
ICMPBUF->ipchksum = ~(uip_ipchksum());
|
|
|
|
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* \internal
|
|
* Register a packet in the forwarding cache so that it won't be
|
|
* forwarded again.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
static void
|
|
fwcache_register(void)
|
|
{
|
|
struct fwcache_entry *fw;
|
|
int i, oldest;
|
|
|
|
oldest = FW_TIME;
|
|
fw = NULL;
|
|
|
|
/* Find the oldest entry in the cache. */
|
|
for(i = 0; i < FWCACHE_SIZE; ++i) {
|
|
if(fwcache[i].timer == 0) {
|
|
fw = &fwcache[i];
|
|
break;
|
|
} else if(fwcache[i].timer <= oldest) {
|
|
fw = &fwcache[i];
|
|
oldest = fwcache[i].timer;
|
|
}
|
|
}
|
|
|
|
fw->timer = FW_TIME;
|
|
fw->ipid = BUF->ipid;
|
|
uip_ipaddr_copy(&fw->srcipaddr, &BUF->srcipaddr);
|
|
uip_ipaddr_copy(&fw->destipaddr, &BUF->destipaddr);
|
|
fw->proto = BUF->proto;
|
|
#if notdef
|
|
fw->payload[0] = BUF->srcport;
|
|
fw->payload[1] = BUF->destport;
|
|
#endif
|
|
#if UIP_REASSEMBLY > 0
|
|
fw->len = BUF->len;
|
|
fw->offset = BUF->ipoffset;
|
|
#endif
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* \internal
|
|
* Find a network interface for the IP packet in uip_buf.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
static struct uip_fw_netif *
|
|
find_netif(void)
|
|
{
|
|
struct uip_fw_netif *netif;
|
|
|
|
/* Walk through every network interface to check for a match. */
|
|
for(netif = netifs; netif != NULL; netif = netif->next) {
|
|
if(ipaddr_maskcmp(&BUF->destipaddr, &netif->ipaddr,
|
|
&netif->netmask)) {
|
|
/* If there was a match, we break the loop. */
|
|
return netif;
|
|
}
|
|
}
|
|
|
|
/* If no matching netif was found, we use default netif. */
|
|
return defaultnetif;
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* Output an IP packet on the correct network interface.
|
|
*
|
|
* The IP packet should be present in the uip_buf buffer and its
|
|
* length in the global uip_len variable.
|
|
*
|
|
* \retval UIP_FW_ZEROLEN Indicates that a zero-length packet
|
|
* transmission was attempted and that no packet was sent.
|
|
*
|
|
* \retval UIP_FW_NOROUTE No suitable network interface could be found
|
|
* for the outbound packet, and the packet was not sent.
|
|
*
|
|
* \return The return value from the actual network interface output
|
|
* function is passed unmodified as a return value.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
u8_t
|
|
uip_fw_output(void)
|
|
{
|
|
struct uip_fw_netif *netif;
|
|
#if UIP_BROADCAST
|
|
const struct uip_udpip_hdr *udp = (void *)BUF;
|
|
#endif /* UIP_BROADCAST */
|
|
|
|
if(uip_len == 0) {
|
|
return UIP_FW_ZEROLEN;
|
|
}
|
|
|
|
fwcache_register();
|
|
|
|
#if UIP_BROADCAST
|
|
/* Link local broadcasts go out on all interfaces. */
|
|
if(uip_ipaddr_cmp(&udp->destipaddr, &uip_broadcast_addr)) {
|
|
if(defaultnetif != NULL) {
|
|
defaultnetif->output();
|
|
}
|
|
for(netif = netifs; netif != NULL; netif = netif->next) {
|
|
netif->output();
|
|
}
|
|
return UIP_FW_OK;
|
|
}
|
|
#endif /* UIP_BROADCAST */
|
|
|
|
netif = find_netif();
|
|
/* printf("uip_fw_output: netif %p ->output %p len %d\n", netif,
|
|
netif->output,
|
|
uip_len);*/
|
|
|
|
if(netif == NULL) {
|
|
return UIP_FW_NOROUTE;
|
|
}
|
|
/* If we now have found a suitable network interface, we call its
|
|
output function to send out the packet. */
|
|
return netif->output();
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* Forward an IP packet in the uip_buf buffer.
|
|
*
|
|
*
|
|
*
|
|
* \return UIP_FW_FORWARDED if the packet was forwarded, UIP_FW_LOCAL if
|
|
* the packet should be processed locally.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
u8_t
|
|
uip_fw_forward(void)
|
|
{
|
|
struct fwcache_entry *fw;
|
|
|
|
/* First check if the packet is destined for ourselves and return 0
|
|
to indicate that the packet should be processed locally. */
|
|
if(uip_ipaddr_cmp(&BUF->destipaddr, &uip_hostaddr)) {
|
|
return UIP_FW_LOCAL;
|
|
}
|
|
|
|
#ifdef AODV_COMPLIANCE
|
|
#define udp ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])
|
|
if(udp->proto == UIP_PROTO_UDP && udp->destport == HTONS(UAODV_UDPPORT)) {
|
|
return UIP_FW_LOCAL;
|
|
}
|
|
#endif
|
|
|
|
/* If we use ping IP address configuration, and our IP address is
|
|
not yet configured, we should intercept all ICMP echo packets. */
|
|
#if UIP_PINGADDRCONF
|
|
if(uip_ipaddr_cmp(&uip_hostaddr, &all_zeroes_addr) &&
|
|
BUF->proto == UIP_PROTO_ICMP &&
|
|
ICMPBUF->type == ICMP_ECHO) {
|
|
return UIP_FW_LOCAL;
|
|
}
|
|
#endif /* UIP_PINGADDRCONF */
|
|
|
|
/* Check if the packet is in the forwarding cache already, and if so
|
|
we drop it. */
|
|
|
|
for(fw = fwcache; fw < &fwcache[FWCACHE_SIZE]; ++fw) {
|
|
if(fw->timer != 0 &&
|
|
#if UIP_REASSEMBLY > 0
|
|
fw->len == BUF->len &&
|
|
fw->offset == BUF->ipoffset &&
|
|
#endif
|
|
fw->ipid == BUF->ipid &&
|
|
uip_ipaddr_cmp(&fw->srcipaddr, &BUF->srcipaddr) &&
|
|
uip_ipaddr_cmp(&fw->destipaddr, &BUF->destipaddr) &&
|
|
#if notdef
|
|
fw->payload[0] == BUF->srcport &&
|
|
fw->payload[1] == BUF->destport &&
|
|
#endif
|
|
fw->proto == BUF->proto) {
|
|
/* Drop packet. */
|
|
return UIP_FW_FORWARDED;
|
|
}
|
|
}
|
|
|
|
/* If the TTL reaches zero we produce an ICMP time exceeded message
|
|
in the uip_buf buffer and forward that packet back to the sender
|
|
of the packet. */
|
|
if(BUF->ttl <= 1) {
|
|
/* No time exceeded for broadcasts and multicasts! */
|
|
if(uip_ipaddr_cmp(&BUF->destipaddr, &uip_broadcast_addr)) {
|
|
return UIP_FW_LOCAL;
|
|
}
|
|
time_exceeded();
|
|
}
|
|
|
|
/* Decrement the TTL (time-to-live) value in the IP header */
|
|
BUF->ttl = BUF->ttl - 1;
|
|
|
|
/* Update the IP checksum. */
|
|
if(BUF->ipchksum >= HTONS(0xffff - 0x0100)) {
|
|
BUF->ipchksum = BUF->ipchksum + HTONS(0x0100) + 1;
|
|
} else {
|
|
BUF->ipchksum = BUF->ipchksum + HTONS(0x0100);
|
|
}
|
|
|
|
if(uip_len > 0) {
|
|
uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_TCPIP_HLEN];
|
|
uip_fw_output();
|
|
}
|
|
|
|
#if UIP_BROADCAST
|
|
if(uip_ipaddr_cmp(&BUF->destipaddr, &uip_broadcast_addr)) {
|
|
return UIP_FW_LOCAL;
|
|
}
|
|
#endif /* UIP_BROADCAST */
|
|
|
|
/* Return non-zero to indicate that the packet was forwarded and that no
|
|
other processing should be made. */
|
|
return UIP_FW_FORWARDED;
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* Register a network interface with the forwarding module.
|
|
*
|
|
* \param netif A pointer to the network interface that is to be
|
|
* registered.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
void
|
|
uip_fw_register(struct uip_fw_netif *netif)
|
|
{
|
|
netif->next = netifs;
|
|
netifs = netif;
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* Register a default network interface.
|
|
*
|
|
* All packets that don't go out on any of the other interfaces will
|
|
* be routed to the default interface.
|
|
*
|
|
* \param netif A pointer to the network interface that is to be
|
|
* registered.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
void
|
|
uip_fw_default(struct uip_fw_netif *netif)
|
|
{
|
|
defaultnetif = netif;
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/**
|
|
* Perform periodic processing.
|
|
*/
|
|
/*------------------------------------------------------------------------------*/
|
|
void
|
|
uip_fw_periodic(void)
|
|
{
|
|
struct fwcache_entry *fw;
|
|
for(fw = fwcache; fw < &fwcache[FWCACHE_SIZE]; ++fw) {
|
|
if(fw->timer > 0) {
|
|
--fw->timer;
|
|
}
|
|
}
|
|
}
|
|
/*------------------------------------------------------------------------------*/
|
|
/** @} */
|
|
/** @} */
|