8e7ff6773a
A few new rules in checkpatch.pl since linklocal.c was added. Signed-off-by: Joe Hershberger <joe.hershberger@ni.com> Acked-by: Simon Glass <sjg@chromium.org>
347 lines
8.4 KiB
C
347 lines
8.4 KiB
C
/*
|
|
* RFC3927 ZeroConf IPv4 Link-Local addressing
|
|
* (see <http://www.zeroconf.org/>)
|
|
*
|
|
* Copied from BusyBox - networking/zcip.c
|
|
*
|
|
* Copyright (C) 2003 by Arthur van Hoff (avh@strangeberry.com)
|
|
* Copyright (C) 2004 by David Brownell
|
|
* Copyright (C) 2010 by Joe Hershberger
|
|
*
|
|
* Licensed under the GPL v2 or later
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <net.h>
|
|
#include "arp.h"
|
|
#include "net_rand.h"
|
|
|
|
/* We don't need more than 32 bits of the counter */
|
|
#define MONOTONIC_MS() ((unsigned)get_timer(0) * (1000 / CONFIG_SYS_HZ))
|
|
|
|
enum {
|
|
/* 169.254.0.0 */
|
|
LINKLOCAL_ADDR = 0xa9fe0000,
|
|
|
|
IN_CLASSB_NET = 0xffff0000,
|
|
IN_CLASSB_HOST = 0x0000ffff,
|
|
|
|
/* protocol timeout parameters, specified in seconds */
|
|
PROBE_WAIT = 1,
|
|
PROBE_MIN = 1,
|
|
PROBE_MAX = 2,
|
|
PROBE_NUM = 3,
|
|
MAX_CONFLICTS = 10,
|
|
RATE_LIMIT_INTERVAL = 60,
|
|
ANNOUNCE_WAIT = 2,
|
|
ANNOUNCE_NUM = 2,
|
|
ANNOUNCE_INTERVAL = 2,
|
|
DEFEND_INTERVAL = 10
|
|
};
|
|
|
|
/* States during the configuration process. */
|
|
static enum ll_state_t {
|
|
PROBE = 0,
|
|
RATE_LIMIT_PROBE,
|
|
ANNOUNCE,
|
|
MONITOR,
|
|
DEFEND,
|
|
DISABLED
|
|
} state = DISABLED;
|
|
|
|
static struct in_addr ip;
|
|
static int timeout_ms = -1;
|
|
static unsigned deadline_ms;
|
|
static unsigned conflicts;
|
|
static unsigned nprobes;
|
|
static unsigned nclaims;
|
|
static int ready;
|
|
static unsigned int seed;
|
|
|
|
static void link_local_timeout(void);
|
|
|
|
/**
|
|
* Pick a random link local IP address on 169.254/16, except that
|
|
* the first and last 256 addresses are reserved.
|
|
*/
|
|
static struct in_addr pick(void)
|
|
{
|
|
unsigned tmp;
|
|
struct in_addr ip;
|
|
|
|
do {
|
|
tmp = rand_r(&seed) & IN_CLASSB_HOST;
|
|
} while (tmp > (IN_CLASSB_HOST - 0x0200));
|
|
ip.s_addr = htonl((LINKLOCAL_ADDR + 0x0100) + tmp);
|
|
return ip;
|
|
}
|
|
|
|
/**
|
|
* Return milliseconds of random delay, up to "secs" seconds.
|
|
*/
|
|
static inline unsigned random_delay_ms(unsigned secs)
|
|
{
|
|
return rand_r(&seed) % (secs * 1000);
|
|
}
|
|
|
|
static void configure_wait(void)
|
|
{
|
|
if (timeout_ms == -1)
|
|
return;
|
|
|
|
/* poll, being ready to adjust current timeout */
|
|
if (!timeout_ms)
|
|
timeout_ms = random_delay_ms(PROBE_WAIT);
|
|
|
|
/* set deadline_ms to the point in time when we timeout */
|
|
deadline_ms = MONOTONIC_MS() + timeout_ms;
|
|
|
|
debug_cond(DEBUG_DEV_PKT, "...wait %d %s nprobes=%u, nclaims=%u\n",
|
|
timeout_ms, eth_get_name(), nprobes, nclaims);
|
|
|
|
NetSetTimeout(timeout_ms, link_local_timeout);
|
|
}
|
|
|
|
void link_local_start(void)
|
|
{
|
|
ip = getenv_ip("llipaddr");
|
|
if (ip.s_addr != 0 &&
|
|
(ntohl(ip.s_addr) & IN_CLASSB_NET) != LINKLOCAL_ADDR) {
|
|
puts("invalid link address");
|
|
net_set_state(NETLOOP_FAIL);
|
|
return;
|
|
}
|
|
net_netmask.s_addr = IN_CLASSB_NET;
|
|
|
|
seed = seed_mac();
|
|
if (ip.s_addr == 0)
|
|
ip = pick();
|
|
|
|
state = PROBE;
|
|
timeout_ms = 0;
|
|
conflicts = 0;
|
|
nprobes = 0;
|
|
nclaims = 0;
|
|
ready = 0;
|
|
|
|
configure_wait();
|
|
}
|
|
|
|
static void link_local_timeout(void)
|
|
{
|
|
switch (state) {
|
|
case PROBE:
|
|
/* timeouts in the PROBE state mean no conflicting ARP packets
|
|
have been received, so we can progress through the states */
|
|
if (nprobes < PROBE_NUM) {
|
|
struct in_addr zero_ip = {.s_addr = 0};
|
|
|
|
nprobes++;
|
|
debug_cond(DEBUG_LL_STATE, "probe/%u %s@%pI4\n",
|
|
nprobes, eth_get_name(), &ip);
|
|
arp_raw_request(zero_ip, net_null_ethaddr, ip);
|
|
timeout_ms = PROBE_MIN * 1000;
|
|
timeout_ms += random_delay_ms(PROBE_MAX - PROBE_MIN);
|
|
} else {
|
|
/* Switch to announce state */
|
|
state = ANNOUNCE;
|
|
nclaims = 0;
|
|
debug_cond(DEBUG_LL_STATE, "announce/%u %s@%pI4\n",
|
|
nclaims, eth_get_name(), &ip);
|
|
arp_raw_request(ip, net_ethaddr, ip);
|
|
timeout_ms = ANNOUNCE_INTERVAL * 1000;
|
|
}
|
|
break;
|
|
case RATE_LIMIT_PROBE:
|
|
/* timeouts in the RATE_LIMIT_PROBE state mean no conflicting
|
|
ARP packets have been received, so we can move immediately
|
|
to the announce state */
|
|
state = ANNOUNCE;
|
|
nclaims = 0;
|
|
debug_cond(DEBUG_LL_STATE, "announce/%u %s@%pI4\n",
|
|
nclaims, eth_get_name(), &ip);
|
|
arp_raw_request(ip, net_ethaddr, ip);
|
|
timeout_ms = ANNOUNCE_INTERVAL * 1000;
|
|
break;
|
|
case ANNOUNCE:
|
|
/* timeouts in the ANNOUNCE state mean no conflicting ARP
|
|
packets have been received, so we can progress through
|
|
the states */
|
|
if (nclaims < ANNOUNCE_NUM) {
|
|
nclaims++;
|
|
debug_cond(DEBUG_LL_STATE, "announce/%u %s@%pI4\n",
|
|
nclaims, eth_get_name(), &ip);
|
|
arp_raw_request(ip, net_ethaddr, ip);
|
|
timeout_ms = ANNOUNCE_INTERVAL * 1000;
|
|
} else {
|
|
/* Switch to monitor state */
|
|
state = MONITOR;
|
|
printf("Successfully assigned %pI4\n", &ip);
|
|
net_copy_ip(&net_ip, &ip);
|
|
ready = 1;
|
|
conflicts = 0;
|
|
timeout_ms = -1;
|
|
/* Never timeout in the monitor state */
|
|
NetSetTimeout(0, NULL);
|
|
|
|
/* NOTE: all other exit paths should deconfig ... */
|
|
net_set_state(NETLOOP_SUCCESS);
|
|
return;
|
|
}
|
|
break;
|
|
case DEFEND:
|
|
/* We won! No ARP replies, so just go back to monitor */
|
|
state = MONITOR;
|
|
timeout_ms = -1;
|
|
conflicts = 0;
|
|
break;
|
|
default:
|
|
/* Invalid, should never happen. Restart the whole protocol */
|
|
state = PROBE;
|
|
ip = pick();
|
|
timeout_ms = 0;
|
|
nprobes = 0;
|
|
nclaims = 0;
|
|
break;
|
|
}
|
|
configure_wait();
|
|
}
|
|
|
|
void link_local_receive_arp(struct arp_hdr *arp, int len)
|
|
{
|
|
int source_ip_conflict;
|
|
int target_ip_conflict;
|
|
struct in_addr null_ip = {.s_addr = 0};
|
|
|
|
if (state == DISABLED)
|
|
return;
|
|
|
|
/* We need to adjust the timeout in case we didn't receive a
|
|
conflicting packet. */
|
|
if (timeout_ms > 0) {
|
|
unsigned diff = deadline_ms - MONOTONIC_MS();
|
|
if ((int)(diff) < 0) {
|
|
/* Current time is greater than the expected timeout
|
|
time. This should never happen */
|
|
debug_cond(DEBUG_LL_STATE,
|
|
"missed an expected timeout\n");
|
|
timeout_ms = 0;
|
|
} else {
|
|
debug_cond(DEBUG_INT_STATE, "adjusting timeout\n");
|
|
timeout_ms = diff | 1; /* never 0 */
|
|
}
|
|
}
|
|
#if 0
|
|
/* XXX Don't bother with ethernet link just yet */
|
|
if ((fds[0].revents & POLLIN) == 0) {
|
|
if (fds[0].revents & POLLERR) {
|
|
/*
|
|
* FIXME: links routinely go down;
|
|
*/
|
|
bb_error_msg("iface %s is down", eth_get_name());
|
|
if (ready)
|
|
run(argv, "deconfig", &ip);
|
|
return EXIT_FAILURE;
|
|
}
|
|
continue;
|
|
}
|
|
#endif
|
|
|
|
debug_cond(DEBUG_INT_STATE, "%s recv arp type=%d, op=%d,\n",
|
|
eth_get_name(), ntohs(arp->ar_pro),
|
|
ntohs(arp->ar_op));
|
|
debug_cond(DEBUG_INT_STATE, "\tsource=%pM %pI4\n",
|
|
&arp->ar_sha,
|
|
&arp->ar_spa);
|
|
debug_cond(DEBUG_INT_STATE, "\ttarget=%pM %pI4\n",
|
|
&arp->ar_tha,
|
|
&arp->ar_tpa);
|
|
|
|
if (arp->ar_op != htons(ARPOP_REQUEST) &&
|
|
arp->ar_op != htons(ARPOP_REPLY)) {
|
|
configure_wait();
|
|
return;
|
|
}
|
|
|
|
source_ip_conflict = 0;
|
|
target_ip_conflict = 0;
|
|
|
|
if (memcmp(&arp->ar_spa, &ip, ARP_PLEN) == 0 &&
|
|
memcmp(&arp->ar_sha, net_ethaddr, ARP_HLEN) != 0)
|
|
source_ip_conflict = 1;
|
|
|
|
/*
|
|
* According to RFC 3927, section 2.2.1:
|
|
* Check if packet is an ARP probe by checking for a null source IP
|
|
* then check that target IP is equal to ours and source hw addr
|
|
* is not equal to ours. This condition should cause a conflict only
|
|
* during probe.
|
|
*/
|
|
if (arp->ar_op == htons(ARPOP_REQUEST) &&
|
|
memcmp(&arp->ar_spa, &null_ip, ARP_PLEN) == 0 &&
|
|
memcmp(&arp->ar_tpa, &ip, ARP_PLEN) == 0 &&
|
|
memcmp(&arp->ar_sha, net_ethaddr, ARP_HLEN) != 0) {
|
|
target_ip_conflict = 1;
|
|
}
|
|
|
|
debug_cond(DEBUG_NET_PKT,
|
|
"state = %d, source ip conflict = %d, target ip conflict = "
|
|
"%d\n", state, source_ip_conflict, target_ip_conflict);
|
|
switch (state) {
|
|
case PROBE:
|
|
case ANNOUNCE:
|
|
/* When probing or announcing, check for source IP conflicts
|
|
and other hosts doing ARP probes (target IP conflicts). */
|
|
if (source_ip_conflict || target_ip_conflict) {
|
|
conflicts++;
|
|
state = PROBE;
|
|
if (conflicts >= MAX_CONFLICTS) {
|
|
debug("%s ratelimit\n", eth_get_name());
|
|
timeout_ms = RATE_LIMIT_INTERVAL * 1000;
|
|
state = RATE_LIMIT_PROBE;
|
|
}
|
|
|
|
/* restart the whole protocol */
|
|
ip = pick();
|
|
timeout_ms = 0;
|
|
nprobes = 0;
|
|
nclaims = 0;
|
|
}
|
|
break;
|
|
case MONITOR:
|
|
/* If a conflict, we try to defend with a single ARP probe */
|
|
if (source_ip_conflict) {
|
|
debug("monitor conflict -- defending\n");
|
|
state = DEFEND;
|
|
timeout_ms = DEFEND_INTERVAL * 1000;
|
|
arp_raw_request(ip, net_ethaddr, ip);
|
|
}
|
|
break;
|
|
case DEFEND:
|
|
/* Well, we tried. Start over (on conflict) */
|
|
if (source_ip_conflict) {
|
|
state = PROBE;
|
|
debug("defend conflict -- starting over\n");
|
|
ready = 0;
|
|
net_ip.s_addr = 0;
|
|
|
|
/* restart the whole protocol */
|
|
ip = pick();
|
|
timeout_ms = 0;
|
|
nprobes = 0;
|
|
nclaims = 0;
|
|
}
|
|
break;
|
|
default:
|
|
/* Invalid, should never happen. Restart the whole protocol */
|
|
debug("invalid state -- starting over\n");
|
|
state = PROBE;
|
|
ip = pick();
|
|
timeout_ms = 0;
|
|
nprobes = 0;
|
|
nclaims = 0;
|
|
break;
|
|
}
|
|
configure_wait();
|
|
}
|