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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
;
59 static unsigned int seed
;
61 static void link_local_timeout(void);
64 * Pick a random link local IP address on 169.254/16, except that
65 * the first and last 256 addresses are reserved.
67 static IPaddr_t
pick(void)
72 tmp
= rand_r(&seed
) & IN_CLASSB_HOST
;
73 } while (tmp
> (IN_CLASSB_HOST
- 0x0200));
74 return (IPaddr_t
) htonl((LINKLOCAL_ADDR
+ 0x0100) + tmp
);
78 * Return milliseconds of random delay, up to "secs" seconds.
80 static inline unsigned random_delay_ms(unsigned secs
)
82 return rand_r(&seed
) % (secs
* 1000);
85 static void configure_wait(void)
90 /* poll, being ready to adjust current timeout */
92 timeout_ms
= random_delay_ms(PROBE_WAIT
);
94 /* set deadline_ms to the point in time when we timeout */
95 deadline_ms
= MONOTONIC_MS() + timeout_ms
;
97 debug_cond(DEBUG_DEV_PKT
, "...wait %d %s nprobes=%u, nclaims=%u\n",
98 timeout_ms
, eth_get_name(), nprobes
, nclaims
);
100 NetSetTimeout(timeout_ms
, link_local_timeout
);
103 void link_local_start(void)
105 ip
= getenv_IPaddr("llipaddr");
106 if (ip
!= 0 && (ntohl(ip
) & IN_CLASSB_NET
) != LINKLOCAL_ADDR
) {
107 puts("invalid link address");
108 net_set_state(NETLOOP_FAIL
);
111 NetOurSubnetMask
= IN_CLASSB_NET
;
127 static void link_local_timeout(void)
131 /* timeouts in the PROBE state mean no conflicting ARP packets
132 have been received, so we can progress through the states */
133 if (nprobes
< PROBE_NUM
) {
135 debug_cond(DEBUG_LL_STATE
, "probe/%u %s@%pI4\n",
136 nprobes
, eth_get_name(), &ip
);
137 arp_raw_request(0, NetEtherNullAddr
, ip
);
138 timeout_ms
= PROBE_MIN
* 1000;
139 timeout_ms
+= random_delay_ms(PROBE_MAX
- PROBE_MIN
);
141 /* Switch to announce state */
144 debug_cond(DEBUG_LL_STATE
, "announce/%u %s@%pI4\n",
145 nclaims
, eth_get_name(), &ip
);
146 arp_raw_request(ip
, NetOurEther
, ip
);
147 timeout_ms
= ANNOUNCE_INTERVAL
* 1000;
150 case RATE_LIMIT_PROBE
:
151 /* timeouts in the RATE_LIMIT_PROBE state mean no conflicting
152 ARP packets have been received, so we can move immediately
153 to the announce state */
156 debug_cond(DEBUG_LL_STATE
, "announce/%u %s@%pI4\n",
157 nclaims
, eth_get_name(), &ip
);
158 arp_raw_request(ip
, NetOurEther
, ip
);
159 timeout_ms
= ANNOUNCE_INTERVAL
* 1000;
162 /* timeouts in the ANNOUNCE state mean no conflicting ARP
163 packets have been received, so we can progress through
165 if (nclaims
< ANNOUNCE_NUM
) {
167 debug_cond(DEBUG_LL_STATE
, "announce/%u %s@%pI4\n",
168 nclaims
, eth_get_name(), &ip
);
169 arp_raw_request(ip
, NetOurEther
, ip
);
170 timeout_ms
= ANNOUNCE_INTERVAL
* 1000;
172 /* Switch to monitor state */
174 printf("Successfully assigned %pI4\n", &ip
);
175 NetCopyIP(&NetOurIP
, &ip
);
179 /* Never timeout in the monitor state */
180 NetSetTimeout(0, NULL
);
182 /* NOTE: all other exit paths should deconfig ... */
183 net_set_state(NETLOOP_SUCCESS
);
188 /* We won! No ARP replies, so just go back to monitor */
194 /* Invalid, should never happen. Restart the whole protocol */
205 void link_local_receive_arp(struct arp_hdr
*arp
, int len
)
207 int source_ip_conflict
;
208 int target_ip_conflict
;
210 if (state
== DISABLED
)
213 /* We need to adjust the timeout in case we didn't receive a
214 conflicting packet. */
215 if (timeout_ms
> 0) {
216 unsigned diff
= deadline_ms
- MONOTONIC_MS();
217 if ((int)(diff
) < 0) {
218 /* Current time is greater than the expected timeout
219 time. This should never happen */
220 debug_cond(DEBUG_LL_STATE
,
221 "missed an expected timeout\n");
224 debug_cond(DEBUG_INT_STATE
, "adjusting timeout\n");
225 timeout_ms
= diff
| 1; /* never 0 */
229 /* XXX Don't bother with ethernet link just yet */
230 if ((fds
[0].revents
& POLLIN
) == 0) {
231 if (fds
[0].revents
& POLLERR
) {
233 * FIXME: links routinely go down;
235 bb_error_msg("iface %s is down", eth_get_name());
237 run(argv
, "deconfig", &ip
);
245 debug_cond(DEBUG_INT_STATE
, "%s recv arp type=%d, op=%d,\n",
246 eth_get_name(), ntohs(arp
->ar_pro
),
248 debug_cond(DEBUG_INT_STATE
, "\tsource=%pM %pI4\n",
251 debug_cond(DEBUG_INT_STATE
, "\ttarget=%pM %pI4\n",
255 if (arp
->ar_op
!= htons(ARPOP_REQUEST
)
256 && arp
->ar_op
!= htons(ARPOP_REPLY
)
262 source_ip_conflict
= 0;
263 target_ip_conflict
= 0;
265 if (memcmp(&arp
->ar_spa
, &ip
, ARP_PLEN
) == 0
266 && memcmp(&arp
->ar_sha
, NetOurEther
, ARP_HLEN
) != 0
268 source_ip_conflict
= 1;
270 if (arp
->ar_op
== htons(ARPOP_REQUEST
)
271 && memcmp(&arp
->ar_tpa
, &ip
, ARP_PLEN
) == 0
272 && memcmp(&arp
->ar_tha
, NetOurEther
, ARP_HLEN
) != 0
274 target_ip_conflict
= 1;
277 debug_cond(DEBUG_NET_PKT
,
278 "state = %d, source ip conflict = %d, target ip conflict = "
279 "%d\n", state
, source_ip_conflict
, target_ip_conflict
);
283 /* When probing or announcing, check for source IP conflicts
284 and other hosts doing ARP probes (target IP conflicts). */
285 if (source_ip_conflict
|| target_ip_conflict
) {
288 if (conflicts
>= MAX_CONFLICTS
) {
289 debug("%s ratelimit\n", eth_get_name());
290 timeout_ms
= RATE_LIMIT_INTERVAL
* 1000;
291 state
= RATE_LIMIT_PROBE
;
294 /* restart the whole protocol */
302 /* If a conflict, we try to defend with a single ARP probe */
303 if (source_ip_conflict
) {
304 debug("monitor conflict -- defending\n");
306 timeout_ms
= DEFEND_INTERVAL
* 1000;
307 arp_raw_request(ip
, NetOurEther
, ip
);
311 /* Well, we tried. Start over (on conflict) */
312 if (source_ip_conflict
) {
314 debug("defend conflict -- starting over\n");
318 /* restart the whole protocol */
326 /* Invalid, should never happen. Restart the whole protocol */
327 debug("invalid state -- starting over\n");