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git.ipfire.org Git - people/ms/u-boot.git/blob - net/link_local.c
2 * RFC3927 ZeroConf IPv4 Link-Local addressing
3 * (see <http://www.zeroconf.org/>)
5 * Copied from BusyBox - networking/zcip.c
7 * Copyright (C) 2003 by Arthur van Hoff (avh@strangeberry.com)
8 * Copyright (C) 2004 by David Brownell
9 * Copyright (C) 2010 by Joe Hershberger
11 * Licensed under the GPL v2 or later
19 /* We don't need more than 32 bits of the counter */
20 #define MONOTONIC_MS() ((unsigned)get_timer(0) * (1000 / CONFIG_SYS_HZ))
24 LINKLOCAL_ADDR
= 0xa9fe0000,
26 IN_CLASSB_NET
= 0xffff0000,
27 IN_CLASSB_HOST
= 0x0000ffff,
29 /* protocol timeout parameters, specified in seconds */
35 RATE_LIMIT_INTERVAL
= 60,
38 ANNOUNCE_INTERVAL
= 2,
42 /* States during the configuration process. */
43 static enum ll_state_t
{
53 static int timeout_ms
= -1;
54 static unsigned deadline_ms
;
55 static unsigned conflicts
;
56 static unsigned nprobes
;
57 static unsigned nclaims
;
60 static void link_local_timeout(void);
63 * Pick a random link local IP address on 169.254/16, except that
64 * the first and last 256 addresses are reserved.
66 static IPaddr_t
pick(void)
71 tmp
= rand() & IN_CLASSB_HOST
;
72 } while (tmp
> (IN_CLASSB_HOST
- 0x0200));
73 return (IPaddr_t
) htonl((LINKLOCAL_ADDR
+ 0x0100) + tmp
);
77 * Return milliseconds of random delay, up to "secs" seconds.
79 static inline unsigned random_delay_ms(unsigned secs
)
81 return rand() % (secs
* 1000);
84 static void configure_wait(void)
89 /* poll, being ready to adjust current timeout */
91 timeout_ms
= random_delay_ms(PROBE_WAIT
);
93 /* set deadline_ms to the point in time when we timeout */
94 deadline_ms
= MONOTONIC_MS() + timeout_ms
;
96 debug("...wait %d %s nprobes=%u, nclaims=%u\n",
97 timeout_ms
, eth_get_name(), nprobes
, nclaims
);
99 NetSetTimeout(timeout_ms
, link_local_timeout
);
102 void link_local_start(void)
104 ip
= getenv_IPaddr("llipaddr");
105 if (ip
!= 0 && (ip
& IN_CLASSB_NET
) != LINKLOCAL_ADDR
) {
106 puts("invalid link address");
107 net_set_state(NETLOOP_FAIL
);
110 NetOurSubnetMask
= IN_CLASSB_NET
;
126 static void link_local_timeout(void)
130 /* timeouts in the PROBE state mean no conflicting ARP packets
131 have been received, so we can progress through the states */
132 if (nprobes
< PROBE_NUM
) {
134 debug("probe/%u %s@%pI4\n",
135 nprobes
, eth_get_name(), &ip
);
136 arp_raw_request(0, NetEtherNullAddr
, ip
);
137 timeout_ms
= PROBE_MIN
* 1000;
138 timeout_ms
+= random_delay_ms(PROBE_MAX
- PROBE_MIN
);
140 /* Switch to announce state */
143 debug("announce/%u %s@%pI4\n",
144 nclaims
, eth_get_name(), &ip
);
145 arp_raw_request(ip
, NetOurEther
, ip
);
146 timeout_ms
= ANNOUNCE_INTERVAL
* 1000;
149 case RATE_LIMIT_PROBE
:
150 /* timeouts in the RATE_LIMIT_PROBE state mean no conflicting
151 ARP packets have been received, so we can move immediately
152 to the announce state */
155 debug("announce/%u %s@%pI4\n",
156 nclaims
, eth_get_name(), &ip
);
157 arp_raw_request(ip
, NetOurEther
, ip
);
158 timeout_ms
= ANNOUNCE_INTERVAL
* 1000;
161 /* timeouts in the ANNOUNCE state mean no conflicting ARP
162 packets have been received, so we can progress through
164 if (nclaims
< ANNOUNCE_NUM
) {
166 debug("announce/%u %s@%pI4\n",
167 nclaims
, eth_get_name(), &ip
);
168 arp_raw_request(ip
, NetOurEther
, ip
);
169 timeout_ms
= ANNOUNCE_INTERVAL
* 1000;
171 /* Switch to monitor state */
173 printf("Successfully assigned %pI4\n", &ip
);
174 NetCopyIP(&NetOurIP
, &ip
);
178 /* Never timeout in the monitor state */
179 NetSetTimeout(0, NULL
);
181 /* NOTE: all other exit paths should deconfig ... */
182 net_set_state(NETLOOP_SUCCESS
);
187 /* We won! No ARP replies, so just go back to monitor */
193 /* Invalid, should never happen. Restart the whole protocol */
204 void link_local_receive_arp(struct arp_hdr
*arp
, int len
)
206 int source_ip_conflict
;
207 int target_ip_conflict
;
209 if (state
== DISABLED
)
212 /* We need to adjust the timeout in case we didn't receive a
213 conflicting packet. */
214 if (timeout_ms
> 0) {
215 unsigned diff
= deadline_ms
- MONOTONIC_MS();
216 if ((int)(diff
) < 0) {
217 /* Current time is greater than the expected timeout
218 time. This should never happen */
219 debug("missed an expected timeout\n");
222 debug("adjusting timeout\n");
223 timeout_ms
= diff
| 1; /* never 0 */
227 * XXX Don't bother with ethernet link just yet
228 if ((fds[0].revents & POLLIN) == 0) {
229 if (fds[0].revents & POLLERR) {
230 // FIXME: links routinely go down;
231 // this shouldn't necessarily exit.
232 bb_error_msg("iface %s is down", eth_get_name());
234 run(argv, "deconfig", &ip);
242 debug("%s recv arp type=%d, op=%d,\n",
243 eth_get_name(), ntohs(arp
->ar_pro
),
245 debug("\tsource=%pM %pI4\n",
248 debug("\ttarget=%pM %pI4\n",
252 if (arp
->ar_op
!= htons(ARPOP_REQUEST
)
253 && arp
->ar_op
!= htons(ARPOP_REPLY
)
259 source_ip_conflict
= 0;
260 target_ip_conflict
= 0;
262 if (memcmp(&arp
->ar_spa
, &ip
, ARP_PLEN
) == 0
263 && memcmp(&arp
->ar_sha
, NetOurEther
, ARP_HLEN
) != 0
265 source_ip_conflict
= 1;
267 if (arp
->ar_op
== htons(ARPOP_REQUEST
)
268 && memcmp(&arp
->ar_tpa
, &ip
, ARP_PLEN
) == 0
269 && memcmp(&arp
->ar_tha
, NetOurEther
, ARP_HLEN
) != 0
271 target_ip_conflict
= 1;
274 debug("state = %d, source ip conflict = %d, target ip conflict = %d\n",
275 state
, source_ip_conflict
, target_ip_conflict
);
279 /* When probing or announcing, check for source IP conflicts
280 and other hosts doing ARP probes (target IP conflicts). */
281 if (source_ip_conflict
|| target_ip_conflict
) {
284 if (conflicts
>= MAX_CONFLICTS
) {
285 debug("%s ratelimit\n", eth_get_name());
286 timeout_ms
= RATE_LIMIT_INTERVAL
* 1000;
287 state
= RATE_LIMIT_PROBE
;
290 /* restart the whole protocol */
298 /* If a conflict, we try to defend with a single ARP probe */
299 if (source_ip_conflict
) {
300 debug("monitor conflict -- defending\n");
302 timeout_ms
= DEFEND_INTERVAL
* 1000;
303 arp_raw_request(ip
, NetOurEther
, ip
);
307 /* Well, we tried. Start over (on conflict) */
308 if (source_ip_conflict
) {
310 debug("defend conflict -- starting over\n");
314 /* restart the whole protocol */
322 /* Invalid, should never happen. Restart the whole protocol */
323 debug("invalid state -- starting over\n");