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contiki/core/net/ipv4/uaodv.c

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/*
* 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.
*
*/
/**
* \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/ipv4/uaodv-def.h"
#include "net/ipv4/uaodv-rt.h"
#define NDEBUG
#include "lib/assert.h"
#ifdef CC2420_RADIO
#include "cc2420.h"
#define RSSI_THRESHOLD -39 /* accept -39 ... xx */
#endif
/* This implementation never expires routes!!! */
#define MY_ROUTE_TIMEOUT 0x7fffffff /* Should be 0xffffffff! */
#define MY_NET_DIAMETER 20
PROCESS(uaodv_process, "uAODV");
static struct uip_udp_conn *bcastconn, *unicastconn;
/* Compare sequence numbers as per RFC 3561. */
#define SCMP32(a, b) ((int32_t)((a) - (b)))
static CC_INLINE uint32_t
last_known_seqno(uip_ipaddr_t *host)
{
struct uaodv_rt_entry *route = uaodv_rt_lookup_any(host);
if(route != NULL)
return uip_htonl(route->hseqno);
return 0;
}
static uint32_t rreq_id, my_hseqno; /* In host byte order! */
#define NFWCACHE 16
static struct {
uip_ipaddr_t orig;
uint32_t id;
} fwcache[NFWCACHE];
static CC_INLINE int
fwc_lookup(const uip_ipaddr_t *orig, const uint32_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 uint32_t *id)
{
unsigned n = (orig->u8[2] + orig->u8[3]) % NFWCACHE;
fwcache[n].id = *id;
uip_ipaddr_copy(&fwcache[n].orig, orig);
}
#ifdef NDEBUG
#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 BUF ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define uip_udp_sender() (&BUF->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_udp_packet_send(unicastconn, buf, len);
}
/*---------------------------------------------------------------------------*/
#ifdef AODV_BAD_HOP_EXTENSION
static unsigned
add_rreq_extensions(void *_p)
{
struct uaodv_bad_hop_ext *p = _p;
uip_ipaddr_t *a = p->addrs;
unsigned i, n;
#define SCALE_RETRANS_THRESHOLD (3*4)
cc2420_check_remote(0xffff); /* Age table. */
n = 0;
for (i = 0; i < NNEIGBOURS; i++) {
if (neigbours[i].nretrans >= SCALE_RETRANS_THRESHOLD
&& neigbours[i].mac != 0xffff) {
a->u16[0] = uip_hostaddr.u16[0];
a->u16[1] = neigbours[i].mac;
n++;
if(n == 15)
break; /* Avoid buffer overrun */
print_debug("BAD HOP %d.%d.%d.%d\t%d\n",
uip_ipaddr_to_quad(a), neigbours[i].nretrans);
}
}
if(n == 0)
return 0;
p->type = RREQ_BAD_HOP_EXT;
p->length = 2 + 4*n; /* Two unused bytes + addresses */
return 2 + p->length; /* Type + len + extension data */
}
#else
#define add_rreq_extensions(p) 0 /* Don't add anything */
#endif
static void
send_rreq(uip_ipaddr_t *addr)
{
struct uaodv_msg_rreq *rm = (struct uaodv_msg_rreq *)uip_appdata;
int len;
print_debug("send RREQ for %d.%d.%d.%d\n", uip_ipaddr_to_quad(addr));
rm->type = UAODV_RREQ_TYPE;
rm->dest_seqno = last_known_seqno(addr);
if(rm->dest_seqno == 0)
rm->flags = UAODV_RREQ_UNKSEQNO;
else
rm->flags = 0;
rm->reserved = 0;
rm->hop_count = 0;
rm->rreq_id = uip_htonl(rreq_id++);
uip_ipaddr_copy(&rm->dest_addr, addr);
uip_gethostaddr(&rm->orig_addr);
my_hseqno++; /* Always */
rm->orig_seqno = uip_htonl(my_hseqno);
bcastconn->ttl = MY_NET_DIAMETER;
len = sizeof(struct uaodv_msg_rreq);
len += add_rreq_extensions(rm + 1);
uip_udp_packet_send(bcastconn, rm, len);
}
/*---------------------------------------------------------------------------*/
static void
send_rrep(uip_ipaddr_t *dest, uip_ipaddr_t *nexthop, uip_ipaddr_t *orig,
uint32_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->prefix_sz = 0; /* I.e a /32 route. */
rm->hop_count = hop_count;
uip_ipaddr_copy(&rm->orig_addr, orig);
rm->dest_seqno = *seqno;
uip_ipaddr_copy(&rm->dest_addr, dest);
rm->lifetime = UIP_HTONL(MY_ROUTE_TIMEOUT);
sendto(nexthop, rm, sizeof(struct uaodv_msg_rrep));
}
/*---------------------------------------------------------------------------*/
static void
send_rerr(uip_ipaddr_t *addr, uint32_t *seqno)
{
struct uaodv_msg_rerr *rm = (struct uaodv_msg_rerr *)uip_appdata;
print_debug("send RERR for %d.%d.%d.%d\n", uip_ipaddr_to_quad(addr));
rm->type = UAODV_RERR_TYPE;
rm->reserved = 0;
rm->dest_count = 1;
uip_ipaddr_copy(&rm->unreach[0].addr, addr);
rm->unreach[0].seqno = *seqno;
if(*seqno == 0)
rm->flags = UAODV_RERR_UNKNOWN;
else
rm->flags = 0;
uip_udp_packet_send(bcastconn, rm, sizeof(struct uaodv_msg_rerr));
}
/*---------------------------------------------------------------------------*/
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;
print_debug("RREQ %d.%d.%d.%d -> %d.%d.%d.%d ttl=%u"
" orig=%d.%d.%d.%d seq=%lu hops=%u dest=%d.%d.%d.%d seq=%lu\n",
uip_ipaddr_to_quad(&BUF->srcipaddr),
uip_ipaddr_to_quad(&BUF->destipaddr),
BUF->ttl,
uip_ipaddr_to_quad(&rm->orig_addr), uip_ntohl(rm->orig_seqno),
rm->hop_count,
uip_ipaddr_to_quad(&rm->dest_addr), uip_ntohl(rm->dest_seqno));
if(uip_ipaddr_cmp(&rm->orig_addr, &uip_hostaddr)) {
return; /* RREQ looped back! */
}
#ifdef CC2420_RADIO
{
int ret = cc2420_check_remote(uip_udp_sender()->u16[1]);
if(ret == REMOTE_YES) {
print_debug("RREQ drop is remote\n");
return;
} else if (ret == REMOTE_NO) {
/* Is neigbour, accept it. */
} else if(cc2420_last_rssi < RSSI_THRESHOLD) {
print_debug("RREQ drop %d %d\n", cc2420_last_rssi,
cc2420_last_correlation);
return;
}
}
#endif
#ifdef AODV_BAD_HOP_EXTENSION
if(uip_len > (sizeof(*rm) + 2)) {
struct uaodv_bad_hop_ext *ext = (void *)(uip_appdata + sizeof(*rm));
uint8_t *end = uip_appdata + uip_len;
for(;
(uint8_t *)ext < end;
ext = (void *)((uint8_t *)ext + ext->length + 2)) {
uint8_t *eend = (uint8_t *)ext + ext->length;
if(eend > end)
eend = end;
if(ext->type == RREQ_BAD_HOP_EXT) {
uip_ipaddr_t *a;
for(a = ext->addrs; (uint8_t *)a < eend; a++) {
if(uip_ipaddr_cmp(a, &uip_hostaddr)) {
print_debug("BAD_HOP drop\n");
return;
}
}
}
}
}
#endif /* AODV_BAD_HOP_EXTENSION */
/* New reverse route? */
rt = uaodv_rt_lookup(&rm->orig_addr);
if(rt == NULL
|| (SCMP32(uip_ntohl(rm->orig_seqno), rt->hseqno) > 0) /* New route. */
|| (SCMP32(uip_ntohl(rm->orig_seqno), rt->hseqno) == 0
&& rm->hop_count < rt->hop_count)) { /* Better route. */
print_debug("Inserting1\n");
rt = uaodv_rt_add(&rm->orig_addr, uip_udp_sender(),
rm->hop_count, &rm->orig_seqno);
}
/* Check if it is for our address or a fresh route. */
if(uip_ipaddr_cmp(&rm->dest_addr, &uip_hostaddr)
|| rm->flags & UAODV_RREQ_DESTONLY) {
fw = NULL;
} else {
fw = uaodv_rt_lookup(&rm->dest_addr);
if(!(rm->flags & UAODV_RREQ_UNKSEQNO)
&& fw != NULL
&& SCMP32(fw->hseqno, uip_ntohl(rm->dest_seqno)) <= 0) {
fw = NULL;
}
}
if (fw != NULL) {
uint32_t net_seqno;
print_debug("RREQ for known route\n");
uip_ipaddr_copy(&dest_addr, &rm->dest_addr);
uip_ipaddr_copy(&orig_addr, &rm->orig_addr);
net_seqno = uip_htonl(fw->hseqno);
send_rrep(&dest_addr, &rt->nexthop, &orig_addr, &net_seqno,
fw->hop_count + 1);
} else if(uip_ipaddr_cmp(&rm->dest_addr, &uip_hostaddr)) {
uint32_t net_seqno;
print_debug("RREQ for our address\n");
uip_ipaddr_copy(&dest_addr, &rm->dest_addr);
uip_ipaddr_copy(&orig_addr, &rm->orig_addr);
my_hseqno++;
if(!(rm->flags & UAODV_RREQ_UNKSEQNO)
&& SCMP32(my_hseqno, uip_ntohl(rm->dest_seqno)) < 0) {
print_debug("New my_hseqno %lu\n", my_hseqno); /* We have rebooted. */
my_hseqno = uip_ntohl(rm->dest_seqno) + 1;
}
net_seqno = uip_htonl(my_hseqno);
send_rrep(&dest_addr, &rt->nexthop, &orig_addr, &net_seqno, 0);
} else if(BUF->ttl > 1) {
int len;
/* Have we seen this RREQ before? */
if(fwc_lookup(&rm->orig_addr, &rm->rreq_id)) {
print_debug("RREQ cached, not fwd\n");
return;
}
fwc_add(&rm->orig_addr, &rm->rreq_id);
print_debug("RREQ fwd\n");
rm->hop_count++;
bcastconn->ttl = BUF->ttl - 1;
len = sizeof(struct uaodv_msg_rreq);
len += add_rreq_extensions(rm + 1);
uip_udp_packet_send(bcastconn, rm, len);
}
}
/*---------------------------------------------------------------------------*/
static void
handle_incoming_rrep(void)
{
struct uaodv_msg_rrep *rm = (struct uaodv_msg_rrep *)uip_appdata;
struct uaodv_rt_entry *rt;
/* Useless HELLO message? */
if(uip_ipaddr_cmp(&BUF->destipaddr, &uip_broadcast_addr)) {
#ifdef AODV_RESPOND_TO_HELLOS
uint32_t net_seqno;
#ifdef CC2420_RADIO
int ret = cc2420_check_remote(uip_udp_sender()->u16[1]);
if(ret == REMOTE_YES) {
print_debug("HELLO drop is remote\n");
return;
} else if (ret == REMOTE_NO) {
/* Is neigbour, accept it. */
} else if(cc2420_last_rssi < RSSI_THRESHOLD) {
print_debug("HELLO drop %d %d\n", cc2420_last_rssi, cc2420_last_correlation);
return;
}
#endif
/* Sometimes it helps to send a non-requested RREP in response! */
net_seqno = uip_htonl(my_hseqno);
send_rrep(&uip_hostaddr, &BUF->srcipaddr, &BUF->srcipaddr, &net_seqno, 0);
#endif
return;
}
print_debug("RREP %d.%d.%d.%d -> %d.%d.%d.%d"
" dest=%d.%d.%d.%d seq=%lu hops=%u orig=%d.%d.%d.%d\n",
uip_ipaddr_to_quad(&BUF->srcipaddr),
uip_ipaddr_to_quad(&BUF->destipaddr),
uip_ipaddr_to_quad(&rm->dest_addr), uip_ntohl(rm->dest_seqno),
rm->hop_count,
uip_ipaddr_to_quad(&rm->orig_addr));
rt = uaodv_rt_lookup(&rm->dest_addr);
/* New forward route? */
if(rt == NULL || (SCMP32(uip_ntohl(rm->dest_seqno), rt->hseqno) > 0)) {
print_debug("Inserting3\n");
rt = uaodv_rt_add(&rm->dest_addr, uip_udp_sender(),
rm->hop_count, &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 %d %d\n",
cc2420_last_rssi, cc2420_last_correlation);
#endif
} else {
print_debug("Not inserting\n");
}
/* Forward RREP towards originator? */
if(uip_ipaddr_cmp(&rm->orig_addr, &uip_hostaddr)) {
print_debug("ROUTE FOUND\n");
if(rm->flags & UAODV_RREP_ACK) {
struct uaodv_msg_rrep_ack *ack = (void *)uip_appdata;
ack->type = UAODV_RREP_ACK_TYPE;
ack->reserved = 0;
sendto(uip_udp_sender(), ack, sizeof(*ack));
}
} else {
rt = uaodv_rt_lookup(&rm->orig_addr);
if(rt == NULL) {
print_debug("RREP received, but no route back to originator... :-( \n");
return;
}
if(rm->flags & UAODV_RREP_ACK) {
print_debug("RREP with ACK request (ignored)!\n");
/* Don't want any RREP-ACKs in return! */
rm->flags &= ~UAODV_RREP_ACK;
}
rm->hop_count++;
print_debug("Fwd RREP to %d.%d.%d.%d\n", uip_ipaddr_to_quad(&rt->nexthop));
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 %d.%d.%d.%d -> %d.%d.%d.%d"
" unreach=%d.%d.%d.%d seq=%lu\n",
uip_ipaddr_to_quad(&BUF->srcipaddr),
uip_ipaddr_to_quad(&BUF->destipaddr),
uip_ipaddr_to_quad((uip_ipaddr_t *)&rm->unreach[0]),
uip_ntohl(rm->unreach[0].seqno));
if(uip_ipaddr_cmp(&rm->unreach[0].addr, &uip_hostaddr))
return;
rt = uaodv_rt_lookup_any(&rm->unreach[0].addr);
if(rt != NULL && uip_ipaddr_cmp(&rt->nexthop, uip_udp_sender())) {
if((rm->flags & UAODV_RERR_UNKNOWN) || rm->unreach[0].seqno == 0
|| SCMP32(rt->hseqno, uip_ntohl(rm->unreach[0].seqno)) <= 0) {
rt->is_bad = 1;
if(rm->flags & UAODV_RERR_UNKNOWN) {
rm->flags &= ~UAODV_RERR_UNKNOWN;
rm->unreach[0].seqno = uip_htonl(rt->hseqno);
}
print_debug("RERR rebroadcast\n");
uip_udp_packet_send(bcastconn, 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 uint32_t bad_seqno; /* In network byte order! */
void
uaodv_bad_dest(uip_ipaddr_t *dest)
{
struct uaodv_rt_entry *rt = uaodv_rt_lookup_any(dest);
if(rt == NULL)
bad_seqno = 0; /* Or flag this in RERR? */
else {
rt->is_bad = 1;
bad_seqno = uip_htonl(rt->hseqno);
}
uip_ipaddr_copy(&bad_dest, dest);
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 %lu\n", (unsigned long) my_hseqno);
bcastconn = udp_broadcast_new(UIP_HTONS(UAODV_UDPPORT), NULL);
unicastconn = udp_broadcast_new(UIP_HTONS(UAODV_UDPPORT), NULL);
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) {
tcpip_poll_udp(bcastconn);
}
}
exit:
command = COMMAND_NONE;
uaodv_rt_flush_all();
uip_udp_remove(bcastconn);
bcastconn = NULL;
uip_udp_remove(unicastconn);
unicastconn = NULL;
printf("uaodv_process exiting\n");
PROCESS_END();
}
/*---------------------------------------------------------------------------*/
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