osd-contiki/core/net/uaodv.c
bg- 8b1cd7a470 * Explain that SCMP32 comes from RFC 3561 and is easy to implement
using 2's complement arithmetic. Unfortunately C only defines
  unsigned arithmetic and consequently machines that don't use 2's
  complement (i.e unknown arithmetic) will have to be dealt with on a
  per machine basis.
2007-04-24 16:37:45 +00:00

491 lines
14 KiB
C

/*
* Copyright (c) 2005, 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.
*
* $Id: uaodv.c,v 1.10 2007/04/24 16:37:45 bg- Exp $
*/
/**
* \file
* Micro implementation of the AODV ad hoc routing protocol
* \author
* Adam Dunkels <adam@sics.se>
*/
#include <stdio.h>
#include <stdarg.h>
#include "contiki.h"
#include "net/uaodv-def.h"
#include "net/uaodv-rt.h"
#ifdef CC2420_RADIO
#include "dev/cc2420.h"
#endif
#define MY_ROUTE_TIMEOUT 0
PROCESS(uaodv_process, "uAODV");
static struct uip_udp_conn *aodvconn, *unicastconn;
/* Compare sequence numbers as per RFC 3561. */
#ifdef __GNUC__
#define SCMP32(a, b) ((int32_t)((a) - (b)))
#else /* __GNUC__ */
/*
* The macro above works for any compiler that does int32_t arithmetic
* in 2's complement. Machines that does not use 2's complement needs
* to figure a different implementation.
*/
#define SCMP32(a, b) exit(1)
#endif /* __GNUC__ */
/*
* When possible, keep state across reboots.
*/
#ifdef __GNUC__
#define NOINIT __attribute__((section(".noinit")))
#else /* __GNUC__ */
#define NOINIT
#endif /* __GNUC__ */
NOINIT static u32_t rreq_id, rreq_seqno;
#define NFWCACHE 16
static struct {
uip_ipaddr_t orig;
u32_t id;
} fwcache[NFWCACHE];
static CC_INLINE int
fwc_lookup(const uip_ipaddr_t *orig, const u32_t *id)
{
unsigned n = (orig->u8[2] + orig->u8[3]) % NFWCACHE;
return fwcache[n].id == *id && uip_ipaddr_cmp(&fwcache[n].orig, orig);
}
static CC_INLINE void
fwc_add(const uip_ipaddr_t *orig, const u32_t *id)
{
unsigned n = orig->u8[3] % NFWCACHE;
fwcache[n].id = *id;
fwcache[n].orig = *orig;
}
#if 0
#define PRINTF(...) do {} while (0)
#define print_debug(...) do{}while(0)
#else
#define PRINTF(...) printf(__VA_ARGS__)
#ifdef __GNUC__
static void
print_debug(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
#endif /* __GNUC__ */
static void
print_debug(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
printf("%d.%d.%d.%d: ", uip_ipaddr_to_quad(&uip_hostaddr));
vprintf(fmt, ap);
va_end(ap);
return;
}
#endif
#define uip_udp_sender() (&((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])->srcipaddr)
/*---------------------------------------------------------------------------*/
static void
sendto(const uip_ipaddr_t *dest, const void *buf, int len)
{
/* XXX: this is a HACK! We're updating the uIP UDP connection
"unicastconn" so that the destination address is the next-hop,
and we're patching the "uip_udp_conn" variable so that it points
the this connection instead. THIS IS NOT A NICE WAY TO DO THIS,
but it is currently nicer than the alternative (requesting a new
poll, and remembering the state, etc.). */
uip_ipaddr_copy(&unicastconn->ripaddr, dest);
uip_udp_conn = unicastconn;
uip_send(buf, len);
}
/*---------------------------------------------------------------------------*/
static void
send_rreq(uip_ipaddr_t *addr)
{
struct uaodv_msg_rreq *rm = (struct uaodv_msg_rreq *)uip_appdata;
print_debug("send RREQ for %d.%d.%d.%d\n", uip_ipaddr_to_quad(addr));
rm->type = UAODV_RREQ_TYPE;
rm->flags = UAODV_RREQ_UNKSEQNO;
rm->reserved = 0;
rm->hop_count = 0;
rm->rreq_id = htonl(rreq_id++);
uip_ipaddr_copy(&rm->dest_addr, addr);
rm->dest_seqno = 0;
uip_gethostaddr(&rm->orig_addr);
rreq_seqno++; /* Always */
rm->orig_seqno = htonl(rreq_seqno);
uip_send((char *)rm, sizeof(struct uaodv_msg_rreq));
}
/*---------------------------------------------------------------------------*/
static void
send_rrep(uip_ipaddr_t *dest, uip_ipaddr_t *nexthop, uip_ipaddr_t *orig,
u32_t *seqno, unsigned hop_count)
{
struct uaodv_msg_rrep *rm = (struct uaodv_msg_rrep *)uip_appdata;
print_debug("send RREP orig=%d.%d.%d.%d hops=%d\n",
uip_ipaddr_to_quad(orig), hop_count);
rm->type = UAODV_RREP_TYPE;
rm->flags = 0;
rm->reserved = 0;
rm->hop_count = hop_count;
uip_ipaddr_copy(&rm->orig_addr, orig);
rm->dest_seqno = htonl(*seqno);
uip_ipaddr_copy(&rm->dest_addr, dest);
rm->lifetime = HTONL(MY_ROUTE_TIMEOUT);
sendto(nexthop, rm, sizeof(struct uaodv_msg_rrep));
print_debug("Sending RREP to %d.%d.%d.%d\n", uip_ipaddr_to_quad(nexthop));
}
/*---------------------------------------------------------------------------*/
static void
send_rerr(uip_ipaddr_t *addr, u32_t *seqno)
{
struct uaodv_msg_rerr *rm = (struct uaodv_msg_rerr *)uip_appdata;
rm->type = UAODV_RERR_TYPE;
rm->flags = 0;
rm->reserved = 0;
rm->dest_count = 1;
uip_ipaddr_copy(&rm->unreach[0].addr, addr);
rm->unreach[0].seqno = *seqno;
sendto(&uip_broadcast_addr, rm, sizeof(struct uaodv_msg_rerr));
print_debug("Broadcasting initial RERR for %d.%d.%d.%d\n",
uip_ipaddr_to_quad(addr));
}
/*---------------------------------------------------------------------------*/
static void
handle_incoming_rreq(void)
{
struct uaodv_msg_rreq *rm = (struct uaodv_msg_rreq *)uip_appdata;
uip_ipaddr_t dest_addr, orig_addr;
struct uaodv_rt_entry *rt, *fw = NULL;
#ifdef CC2420_RADIO
if(cc2420_last_rssi <= -38 || cc2420_last_correlation < 100) {
print_debug("RREQ drop from %d.%d.%d.%d %d %d \n",
uip_ipaddr_to_quad(uip_udp_sender()),
cc2420_last_rssi,
cc2420_last_correlation);
return;
}
if(cc2420_check_remote(uip_udp_sender()->u16[1]) == REMOTE_YES) {
print_debug("RREQ drop from %d.%d.%d.%d is remote\n",
uip_ipaddr_to_quad(uip_udp_sender()));
}
#endif
/* Have we seen this RREQ before? */
if(uip_ipaddr_cmp(&rm->orig_addr, &uip_hostaddr)
|| fwc_lookup(&rm->orig_addr, &rm->rreq_id)) {
print_debug("Not fwd rreq from %d.%d.%d.%d orig_addr %d.%d.%d.%d, rreq_id %lu\n",
uip_ipaddr_to_quad(uip_udp_sender()),
uip_ipaddr_to_quad(&rm->orig_addr),
ntohl(rm->rreq_id));
return;
}
/* New reverse route? */
rt = uaodv_rt_lookup(&rm->orig_addr);
if(rt == NULL
|| (SCMP32(ntohl(rm->orig_seqno), rt->seqno) > 0) /* New route. */
|| (SCMP32(ntohl(rm->orig_seqno), rt->seqno) == 0
&& rm->hop_count < rt->hop_count)) { /* Better route. */
print_debug("Inserting1 %d.%d.%d.%d into routing table, next hop %d.%d.%d.%d, hop_count %u seq %lu\n",
uip_ipaddr_to_quad(&rm->orig_addr),
uip_ipaddr_to_quad(uip_udp_sender()),
rm->hop_count,
ntohl(rm->orig_seqno));
rt = uaodv_rt_add(&rm->orig_addr, uip_udp_sender(),
rm->hop_count, ntohl(rm->orig_seqno));
}
/* Check if it is for our address or an existing route. */
if(uip_ipaddr_cmp(&rm->dest_addr, &uip_hostaddr)
|| (fw = uaodv_rt_lookup(&rm->dest_addr)) != NULL) {
print_debug("RREQ for known address %d.%d.%d.%d\n",
uip_ipaddr_to_quad(&rm->dest_addr));
/* Send an RREP back to the source of the RREQ. */
uip_ipaddr_copy(&dest_addr, &rm->dest_addr);
uip_ipaddr_copy(&orig_addr, &rm->orig_addr);
#ifdef CC2420_RADIO
if(cc2420_check_remote(rt->nexthop.u16[1]) == REMOTE_MAYBE)
cc2420_recv_ok(&rt->nexthop);
#endif
if(fw != NULL) /* Existing route. */
send_rrep(&dest_addr, &rt->nexthop, &orig_addr,
&fw->seqno, fw->hop_count + 1);
else {
rreq_seqno++; /* XXX Not really always. */
send_rrep(&dest_addr, &rt->nexthop, &orig_addr, &rreq_seqno, 0);
}
} else {
print_debug("RREQ for %d.%d.%d.%d orig %d.%d.%d.%d ttl=%d\n",
uip_ipaddr_to_quad(&rm->dest_addr),
uip_ipaddr_to_quad(&rm->orig_addr),
uip_udp_conn->ttl);
fwc_add(&rm->orig_addr, &rm->rreq_id);
rm->hop_count++;
uip_send(rm, sizeof(struct uaodv_msg_rreq));
}
}
/*---------------------------------------------------------------------------*/
static void
handle_incoming_rrep(void)
{
struct uaodv_msg_rrep *rm = (struct uaodv_msg_rrep *)uip_appdata;
struct uaodv_rt_entry *rt;
rt = uaodv_rt_lookup(&rm->dest_addr);
print_debug("RREP received dst=%d.%d.%d.%d rt=%p\n",
uip_ipaddr_to_quad(&rm->dest_addr), rt);
/* New forward route? */
if(rt == NULL || (SCMP32(ntohl(rm->dest_seqno), rt->seqno) > 0)) {
print_debug("Inserting3 %d.%d.%d.%d into routing table, next hop %d.%d.%d.%d, hop_count %u seq %lu.\n",
uip_ipaddr_to_quad(&rm->dest_addr),
uip_ipaddr_to_quad(uip_udp_sender()),
rm->hop_count,
ntohl(rm->dest_seqno));
rt = uaodv_rt_add(&rm->dest_addr, uip_udp_sender(),
rm->hop_count, ntohl(rm->dest_seqno));
#ifdef CC2420_RADIO
/* This link is ok since he is unicasting back to us! */
cc2420_recv_ok(uip_udp_sender());
print_debug("RREP recv ok from %d.%d.%d.%d %d %d \n",
uip_ipaddr_to_quad(uip_udp_sender()),
cc2420_last_rssi,
cc2420_last_correlation);
#endif
} else {
print_debug("Not inserting %d.%d.%d.%d into routing table, next hop %d.%d.%d.%d, hop_count %d.\n",
uip_ipaddr_to_quad(&rm->dest_addr),
uip_ipaddr_to_quad(uip_udp_sender()),
rm->hop_count);
}
/* Forward RREP towards originator? */
if(uip_ipaddr_cmp(&rm->orig_addr, &uip_hostaddr)) {
print_debug("------- COMPLETE ROUTE FOUND\n");
} else {
if(uip_ipaddr_cmp(&((struct uip_udpip_hdr*)&uip_buf[UIP_LLH_LEN])->destipaddr,
&uip_broadcast_addr)) {
print_debug("RREP hello received?\n");
return;
}
rt = uaodv_rt_lookup(&rm->orig_addr);
if(rt == NULL) {
print_debug("RREP received, but no route back to originator... :-( \n");
return;
}
rm->hop_count++;
print_debug("Fwd RREP to %d.%d.%d.%d\n", uip_ipaddr_to_quad(&rt->nexthop));
#ifdef CC2420_RADIO
if(cc2420_check_remote(rt->nexthop.u16[1]) == REMOTE_MAYBE)
cc2420_recv_ok(&rt->nexthop);
#endif
sendto(&rt->nexthop, rm, sizeof(struct uaodv_msg_rrep));
}
}
/*---------------------------------------------------------------------------*/
static void
handle_incoming_rerr(void)
{
struct uaodv_msg_rerr *rm = (struct uaodv_msg_rerr *)uip_appdata;
struct uaodv_rt_entry *rt;
print_debug("RERR received from %d.%d.%d.%d route to %d.%d.%d.%d seq=%lu\n",
uip_ipaddr_to_quad(uip_udp_sender()),
uip_ipaddr_to_quad(&rm->unreach[0].addr),
ntohl(rm->unreach[0].seqno));
rt = uaodv_rt_lookup(&rm->unreach[0].addr);
if(rt != NULL
&& uip_ipaddr_cmp(&rt->nexthop, uip_udp_sender())
&& SCMP32(rt->seqno, ntohl(rm->unreach[0].seqno)) <= 0) {
uaodv_rt_remove(rt);
print_debug("RERR rebroadcast\n");
sendto(&uip_broadcast_addr, rm, sizeof(struct uaodv_msg_rerr));
}
}
/*---------------------------------------------------------------------------*/
static void
handle_incoming_packet(void)
{
struct uaodv_msg *m = (struct uaodv_msg *)uip_appdata;
/* print_debug("New UDP data, AODV packet type %d\n", m->type);*/
switch(m->type) {
case UAODV_RREQ_TYPE:
handle_incoming_rreq();
break;
case UAODV_RREP_TYPE:
handle_incoming_rrep();
break;
case UAODV_RERR_TYPE:
handle_incoming_rerr();
break;
}
}
/*---------------------------------------------------------------------------*/
static enum {
COMMAND_NONE,
COMMAND_SEND_RREQ,
COMMAND_SEND_RERR,
} command;
static uip_ipaddr_t bad_dest;
static u32_t bad_seqno; /* In network byte order! */
void
uaodv_bad_route(struct uaodv_rt_entry *rt)
{
uip_ipaddr_copy(&bad_dest, &rt->dest);
bad_seqno = htonl(rt->seqno);
command = COMMAND_SEND_RERR;
process_post(&uaodv_process, PROCESS_EVENT_MSG, NULL);
}
static uip_ipaddr_t rreq_addr;
static struct timer next_time;
struct uaodv_rt_entry *
uaodv_request_route_to(uip_ipaddr_t *host)
{
struct uaodv_rt_entry *route = uaodv_rt_lookup(host);
if(route != NULL) {
uaodv_rt_lru(route);
return route;
}
/*
* Broadcast protocols must be rate-limited!
*/
if(!timer_expired(&next_time)) {
return NULL;
}
if(command != COMMAND_NONE) {
return NULL;
}
uip_ipaddr_copy(&rreq_addr, host);
command = COMMAND_SEND_RREQ;
process_post(&uaodv_process, PROCESS_EVENT_MSG, NULL);
timer_set(&next_time, CLOCK_SECOND/8); /* Max 10/s per RFC3561. */
return NULL;
}
PROCESS_THREAD(uaodv_process, ev, data)
{
PROCESS_EXITHANDLER(goto exit);
PROCESS_BEGIN();
printf("uaodv_process starting\n");
aodvconn = udp_broadcast_new(HTONS(UAODV_UDPPORT), NULL);
aodvconn->ttl = 1;
unicastconn = udp_broadcast_new(HTONS(UAODV_UDPPORT), NULL);
unicastconn->ttl = 1;
while(1) {
PROCESS_WAIT_EVENT();
if(ev == tcpip_event) {
if(uip_newdata()) {
handle_incoming_packet();
continue;
}
if(uip_poll()) {
if(command == COMMAND_SEND_RREQ) {
if(uaodv_rt_lookup(&rreq_addr) == NULL)
send_rreq(&rreq_addr);
} else if (command == COMMAND_SEND_RERR) {
send_rerr(&bad_dest, &bad_seqno);
}
command = COMMAND_NONE;
continue;
}
}
if(ev == PROCESS_EVENT_MSG) {
#if 1
static struct etimer etimer;
etimer_set(&etimer, 2);
PROCESS_WAIT_UNTIL(etimer_expired(&etimer));
#endif
tcpip_poll_udp(aodvconn);
}
}
exit:
command = COMMAND_NONE;
uaodv_rt_flush_all();
uip_udp_remove(aodvconn);
aodvconn = NULL;
uip_udp_remove(unicastconn);
unicastconn = NULL;
printf("uaodv_process exiting\n");
PROCESS_END();
}
/*---------------------------------------------------------------------------*/