diff options
Diffstat (limited to 'networking/zcip.c')
-rw-r--r-- | networking/zcip.c | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/networking/zcip.c b/networking/zcip.c new file mode 100644 index 000000000..27e281c93 --- /dev/null +++ b/networking/zcip.c | |||
@@ -0,0 +1,546 @@ | |||
1 | /* vi: set sw=4 ts=4: */ | ||
2 | /* | ||
3 | * RFC3927 ZeroConf IPv4 Link-Local addressing | ||
4 | * (see <http://www.zeroconf.org/>) | ||
5 | * | ||
6 | * Copyright (C) 2003 by Arthur van Hoff (avh@strangeberry.com) | ||
7 | * Copyright (C) 2004 by David Brownell | ||
8 | * | ||
9 | * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. | ||
10 | */ | ||
11 | |||
12 | /* | ||
13 | * ZCIP just manages the 169.254.*.* addresses. That network is not | ||
14 | * routed at the IP level, though various proxies or bridges can | ||
15 | * certainly be used. Its naming is built over multicast DNS. | ||
16 | */ | ||
17 | |||
18 | //#define DEBUG | ||
19 | |||
20 | // TODO: | ||
21 | // - more real-world usage/testing, especially daemon mode | ||
22 | // - kernel packet filters to reduce scheduling noise | ||
23 | // - avoid silent script failures, especially under load... | ||
24 | // - link status monitoring (restart on link-up; stop on link-down) | ||
25 | |||
26 | #include "busybox.h" | ||
27 | #include <syslog.h> | ||
28 | #include <poll.h> | ||
29 | #include <sys/wait.h> | ||
30 | #include <netinet/ether.h> | ||
31 | #include <net/ethernet.h> | ||
32 | #include <net/if.h> | ||
33 | #include <net/if_arp.h> | ||
34 | |||
35 | #include <linux/if_packet.h> | ||
36 | #include <linux/sockios.h> | ||
37 | |||
38 | |||
39 | struct arp_packet { | ||
40 | struct ether_header hdr; | ||
41 | struct ether_arp arp; | ||
42 | } ATTRIBUTE_PACKED; | ||
43 | |||
44 | enum { | ||
45 | /* 169.254.0.0 */ | ||
46 | LINKLOCAL_ADDR = 0xa9fe0000, | ||
47 | |||
48 | /* protocol timeout parameters, specified in seconds */ | ||
49 | PROBE_WAIT = 1, | ||
50 | PROBE_MIN = 1, | ||
51 | PROBE_MAX = 2, | ||
52 | PROBE_NUM = 3, | ||
53 | MAX_CONFLICTS = 10, | ||
54 | RATE_LIMIT_INTERVAL = 60, | ||
55 | ANNOUNCE_WAIT = 2, | ||
56 | ANNOUNCE_NUM = 2, | ||
57 | ANNOUNCE_INTERVAL = 2, | ||
58 | DEFEND_INTERVAL = 10 | ||
59 | }; | ||
60 | |||
61 | /* States during the configuration process. */ | ||
62 | enum { | ||
63 | PROBE = 0, | ||
64 | RATE_LIMIT_PROBE, | ||
65 | ANNOUNCE, | ||
66 | MONITOR, | ||
67 | DEFEND | ||
68 | }; | ||
69 | |||
70 | #define VDBG(fmt,args...) \ | ||
71 | do { } while (0) | ||
72 | |||
73 | static unsigned opts; | ||
74 | #define FOREGROUND (opts & 1) | ||
75 | #define QUIT (opts & 2) | ||
76 | |||
77 | /** | ||
78 | * Pick a random link local IP address on 169.254/16, except that | ||
79 | * the first and last 256 addresses are reserved. | ||
80 | */ | ||
81 | static void pick(struct in_addr *ip) | ||
82 | { | ||
83 | unsigned tmp; | ||
84 | |||
85 | /* use cheaper math than lrand48() mod N */ | ||
86 | do { | ||
87 | tmp = (lrand48() >> 16) & IN_CLASSB_HOST; | ||
88 | } while (tmp > (IN_CLASSB_HOST - 0x0200)); | ||
89 | ip->s_addr = htonl((LINKLOCAL_ADDR + 0x0100) + tmp); | ||
90 | } | ||
91 | |||
92 | /* TODO: we need a flag to direct bb_[p]error_msg output to stderr. */ | ||
93 | |||
94 | /** | ||
95 | * Broadcast an ARP packet. | ||
96 | */ | ||
97 | static void arp(int fd, struct sockaddr *saddr, int op, | ||
98 | const struct ether_addr *source_addr, struct in_addr source_ip, | ||
99 | const struct ether_addr *target_addr, struct in_addr target_ip) | ||
100 | { | ||
101 | struct arp_packet p; | ||
102 | memset(&p, 0, sizeof(p)); | ||
103 | |||
104 | // ether header | ||
105 | p.hdr.ether_type = htons(ETHERTYPE_ARP); | ||
106 | memcpy(p.hdr.ether_shost, source_addr, ETH_ALEN); | ||
107 | memset(p.hdr.ether_dhost, 0xff, ETH_ALEN); | ||
108 | |||
109 | // arp request | ||
110 | p.arp.arp_hrd = htons(ARPHRD_ETHER); | ||
111 | p.arp.arp_pro = htons(ETHERTYPE_IP); | ||
112 | p.arp.arp_hln = ETH_ALEN; | ||
113 | p.arp.arp_pln = 4; | ||
114 | p.arp.arp_op = htons(op); | ||
115 | memcpy(&p.arp.arp_sha, source_addr, ETH_ALEN); | ||
116 | memcpy(&p.arp.arp_spa, &source_ip, sizeof (p.arp.arp_spa)); | ||
117 | memcpy(&p.arp.arp_tha, target_addr, ETH_ALEN); | ||
118 | memcpy(&p.arp.arp_tpa, &target_ip, sizeof (p.arp.arp_tpa)); | ||
119 | |||
120 | // send it | ||
121 | if (sendto(fd, &p, sizeof (p), 0, saddr, sizeof (*saddr)) < 0) { | ||
122 | bb_perror_msg("sendto"); | ||
123 | //return -errno; | ||
124 | } | ||
125 | // Currently all callers ignore errors, that's why returns are | ||
126 | // commented out... | ||
127 | //return 0; | ||
128 | } | ||
129 | |||
130 | /** | ||
131 | * Run a script. | ||
132 | */ | ||
133 | static int run(char *script, char *arg, char *intf, struct in_addr *ip) | ||
134 | { | ||
135 | int pid, status; | ||
136 | char *why; | ||
137 | |||
138 | if(1) { //always true: if (script != NULL) | ||
139 | VDBG("%s run %s %s\n", intf, script, arg); | ||
140 | if (ip != NULL) { | ||
141 | char *addr = inet_ntoa(*ip); | ||
142 | setenv("ip", addr, 1); | ||
143 | bb_info_msg("%s %s %s", arg, intf, addr); | ||
144 | } | ||
145 | |||
146 | pid = vfork(); | ||
147 | if (pid < 0) { // error | ||
148 | why = "vfork"; | ||
149 | goto bad; | ||
150 | } else if (pid == 0) { // child | ||
151 | execl(script, script, arg, NULL); | ||
152 | bb_perror_msg("execl"); | ||
153 | _exit(EXIT_FAILURE); | ||
154 | } | ||
155 | |||
156 | if (waitpid(pid, &status, 0) <= 0) { | ||
157 | why = "waitpid"; | ||
158 | goto bad; | ||
159 | } | ||
160 | if (WEXITSTATUS(status) != 0) { | ||
161 | bb_error_msg("script %s failed, exit=%d", | ||
162 | script, WEXITSTATUS(status)); | ||
163 | return -errno; | ||
164 | } | ||
165 | } | ||
166 | return 0; | ||
167 | bad: | ||
168 | status = -errno; | ||
169 | bb_perror_msg("%s %s, %s", arg, intf, why); | ||
170 | return status; | ||
171 | } | ||
172 | |||
173 | |||
174 | /** | ||
175 | * Return milliseconds of random delay, up to "secs" seconds. | ||
176 | */ | ||
177 | static unsigned ATTRIBUTE_ALWAYS_INLINE ms_rdelay(unsigned secs) | ||
178 | { | ||
179 | return lrand48() % (secs * 1000); | ||
180 | } | ||
181 | |||
182 | /** | ||
183 | * main program | ||
184 | */ | ||
185 | |||
186 | /* Used to be auto variables on main() stack, but | ||
187 | * most of them were zero-inited. Moving them to bss | ||
188 | * is more space-efficient. | ||
189 | */ | ||
190 | static const struct in_addr null_ip; // = { 0 }; | ||
191 | static const struct ether_addr null_addr; // = { {0, 0, 0, 0, 0, 0} }; | ||
192 | |||
193 | static struct sockaddr saddr; // memset(0); | ||
194 | static struct in_addr ip; // = { 0 }; | ||
195 | static struct ifreq ifr; //memset(0); | ||
196 | |||
197 | static char *intf; // = NULL; | ||
198 | static char *script; // = NULL; | ||
199 | static suseconds_t timeout; // = 0; // milliseconds | ||
200 | static unsigned conflicts; // = 0; | ||
201 | static unsigned nprobes; // = 0; | ||
202 | static unsigned nclaims; // = 0; | ||
203 | static int ready; // = 0; | ||
204 | static int verbose; // = 0; | ||
205 | static int state = PROBE; | ||
206 | |||
207 | int zcip_main(int argc, char *argv[]) | ||
208 | { | ||
209 | struct ether_addr eth_addr; | ||
210 | char *why; | ||
211 | int fd; | ||
212 | |||
213 | // parse commandline: prog [options] ifname script | ||
214 | char *r_opt; | ||
215 | opt_complementary = "vv:vf"; // -v accumulates and implies -f | ||
216 | opts = getopt32(argc, argv, "fqr:v", &r_opt, &verbose); | ||
217 | if (!FOREGROUND) { | ||
218 | /* Do it early, before all bb_xx_msg calls */ | ||
219 | logmode = LOGMODE_SYSLOG; | ||
220 | openlog(applet_name, 0, LOG_DAEMON); | ||
221 | } | ||
222 | if (opts & 4) { // -r n.n.n.n | ||
223 | if (inet_aton(r_opt, &ip) == 0 | ||
224 | || (ntohl(ip.s_addr) & IN_CLASSB_NET) != LINKLOCAL_ADDR) { | ||
225 | bb_error_msg_and_die("invalid link address"); | ||
226 | } | ||
227 | } | ||
228 | argc -= optind; | ||
229 | argv += optind; | ||
230 | if (argc != 2) | ||
231 | bb_show_usage(); | ||
232 | intf = argv[0]; | ||
233 | script = argv[1]; | ||
234 | setenv("interface", intf, 1); | ||
235 | |||
236 | // initialize the interface (modprobe, ifup, etc) | ||
237 | if (run(script, "init", intf, NULL) < 0) | ||
238 | return EXIT_FAILURE; | ||
239 | |||
240 | // initialize saddr | ||
241 | //memset(&saddr, 0, sizeof (saddr)); | ||
242 | safe_strncpy(saddr.sa_data, intf, sizeof (saddr.sa_data)); | ||
243 | |||
244 | // open an ARP socket | ||
245 | fd = xsocket(PF_PACKET, SOCK_PACKET, htons(ETH_P_ARP)); | ||
246 | // bind to the interface's ARP socket | ||
247 | xbind(fd, &saddr, sizeof (saddr)); | ||
248 | |||
249 | // get the interface's ethernet address | ||
250 | //memset(&ifr, 0, sizeof (ifr)); | ||
251 | strncpy(ifr.ifr_name, intf, sizeof (ifr.ifr_name)); | ||
252 | if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) { | ||
253 | bb_perror_msg_and_die("get ethernet address"); | ||
254 | } | ||
255 | memcpy(ð_addr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN); | ||
256 | |||
257 | // start with some stable ip address, either a function of | ||
258 | // the hardware address or else the last address we used. | ||
259 | // NOTE: the sequence of addresses we try changes only | ||
260 | // depending on when we detect conflicts. | ||
261 | // (SVID 3 bogon: who says that "short" is always 16 bits?) | ||
262 | seed48( (unsigned short*)&ifr.ifr_hwaddr.sa_data ); | ||
263 | if (ip.s_addr == 0) | ||
264 | pick(&ip); | ||
265 | |||
266 | // FIXME cases to handle: | ||
267 | // - zcip already running! | ||
268 | // - link already has local address... just defend/update | ||
269 | |||
270 | // daemonize now; don't delay system startup | ||
271 | if (!FOREGROUND) { | ||
272 | setsid(); | ||
273 | xdaemon(0, 0); | ||
274 | bb_info_msg("start, interface %s", intf); | ||
275 | } | ||
276 | |||
277 | // run the dynamic address negotiation protocol, | ||
278 | // restarting after address conflicts: | ||
279 | // - start with some address we want to try | ||
280 | // - short random delay | ||
281 | // - arp probes to see if another host else uses it | ||
282 | // - arp announcements that we're claiming it | ||
283 | // - use it | ||
284 | // - defend it, within limits | ||
285 | while (1) { | ||
286 | struct pollfd fds[1]; | ||
287 | struct timeval tv1; | ||
288 | struct arp_packet p; | ||
289 | |||
290 | int source_ip_conflict = 0; | ||
291 | int target_ip_conflict = 0; | ||
292 | |||
293 | fds[0].fd = fd; | ||
294 | fds[0].events = POLLIN; | ||
295 | fds[0].revents = 0; | ||
296 | |||
297 | // poll, being ready to adjust current timeout | ||
298 | if (!timeout) { | ||
299 | timeout = ms_rdelay(PROBE_WAIT); | ||
300 | // FIXME setsockopt(fd, SO_ATTACH_FILTER, ...) to | ||
301 | // make the kernel filter out all packets except | ||
302 | // ones we'd care about. | ||
303 | } | ||
304 | // set tv1 to the point in time when we timeout | ||
305 | gettimeofday(&tv1, NULL); | ||
306 | tv1.tv_usec += (timeout % 1000) * 1000; | ||
307 | while (tv1.tv_usec > 1000000) { | ||
308 | tv1.tv_usec -= 1000000; | ||
309 | tv1.tv_sec++; | ||
310 | } | ||
311 | tv1.tv_sec += timeout / 1000; | ||
312 | |||
313 | VDBG("...wait %ld %s nprobes=%d, nclaims=%d\n", | ||
314 | timeout, intf, nprobes, nclaims); | ||
315 | switch (poll(fds, 1, timeout)) { | ||
316 | |||
317 | // timeout | ||
318 | case 0: | ||
319 | VDBG("state = %d\n", state); | ||
320 | switch (state) { | ||
321 | case PROBE: | ||
322 | // timeouts in the PROBE state mean no conflicting ARP packets | ||
323 | // have been received, so we can progress through the states | ||
324 | if (nprobes < PROBE_NUM) { | ||
325 | nprobes++; | ||
326 | VDBG("probe/%d %s@%s\n", | ||
327 | nprobes, intf, inet_ntoa(ip)); | ||
328 | arp(fd, &saddr, ARPOP_REQUEST, | ||
329 | ð_addr, null_ip, | ||
330 | &null_addr, ip); | ||
331 | timeout = PROBE_MIN * 1000; | ||
332 | timeout += ms_rdelay(PROBE_MAX | ||
333 | - PROBE_MIN); | ||
334 | } | ||
335 | else { | ||
336 | // Switch to announce state. | ||
337 | state = ANNOUNCE; | ||
338 | nclaims = 0; | ||
339 | VDBG("announce/%d %s@%s\n", | ||
340 | nclaims, intf, inet_ntoa(ip)); | ||
341 | arp(fd, &saddr, ARPOP_REQUEST, | ||
342 | ð_addr, ip, | ||
343 | ð_addr, ip); | ||
344 | timeout = ANNOUNCE_INTERVAL * 1000; | ||
345 | } | ||
346 | break; | ||
347 | case RATE_LIMIT_PROBE: | ||
348 | // timeouts in the RATE_LIMIT_PROBE state mean no conflicting ARP packets | ||
349 | // have been received, so we can move immediately to the announce state | ||
350 | state = ANNOUNCE; | ||
351 | nclaims = 0; | ||
352 | VDBG("announce/%d %s@%s\n", | ||
353 | nclaims, intf, inet_ntoa(ip)); | ||
354 | arp(fd, &saddr, ARPOP_REQUEST, | ||
355 | ð_addr, ip, | ||
356 | ð_addr, ip); | ||
357 | timeout = ANNOUNCE_INTERVAL * 1000; | ||
358 | break; | ||
359 | case ANNOUNCE: | ||
360 | // timeouts in the ANNOUNCE state mean no conflicting ARP packets | ||
361 | // have been received, so we can progress through the states | ||
362 | if (nclaims < ANNOUNCE_NUM) { | ||
363 | nclaims++; | ||
364 | VDBG("announce/%d %s@%s\n", | ||
365 | nclaims, intf, inet_ntoa(ip)); | ||
366 | arp(fd, &saddr, ARPOP_REQUEST, | ||
367 | ð_addr, ip, | ||
368 | ð_addr, ip); | ||
369 | timeout = ANNOUNCE_INTERVAL * 1000; | ||
370 | } | ||
371 | else { | ||
372 | // Switch to monitor state. | ||
373 | state = MONITOR; | ||
374 | // link is ok to use earlier | ||
375 | // FIXME update filters | ||
376 | run(script, "config", intf, &ip); | ||
377 | ready = 1; | ||
378 | conflicts = 0; | ||
379 | timeout = -1; // Never timeout in the monitor state. | ||
380 | |||
381 | // NOTE: all other exit paths | ||
382 | // should deconfig ... | ||
383 | if (QUIT) | ||
384 | return EXIT_SUCCESS; | ||
385 | } | ||
386 | break; | ||
387 | case DEFEND: | ||
388 | // We won! No ARP replies, so just go back to monitor. | ||
389 | state = MONITOR; | ||
390 | timeout = -1; | ||
391 | conflicts = 0; | ||
392 | break; | ||
393 | default: | ||
394 | // Invalid, should never happen. Restart the whole protocol. | ||
395 | state = PROBE; | ||
396 | pick(&ip); | ||
397 | timeout = 0; | ||
398 | nprobes = 0; | ||
399 | nclaims = 0; | ||
400 | break; | ||
401 | } // switch (state) | ||
402 | break; // case 0 (timeout) | ||
403 | // packets arriving | ||
404 | case 1: | ||
405 | // We need to adjust the timeout in case we didn't receive | ||
406 | // a conflicting packet. | ||
407 | if (timeout > 0) { | ||
408 | struct timeval tv2; | ||
409 | |||
410 | gettimeofday(&tv2, NULL); | ||
411 | if (timercmp(&tv1, &tv2, <)) { | ||
412 | // Current time is greater than the expected timeout time. | ||
413 | // Should never happen. | ||
414 | VDBG("missed an expected timeout\n"); | ||
415 | timeout = 0; | ||
416 | } else { | ||
417 | VDBG("adjusting timeout\n"); | ||
418 | timersub(&tv1, &tv2, &tv1); | ||
419 | timeout = 1000 * tv1.tv_sec | ||
420 | + tv1.tv_usec / 1000; | ||
421 | } | ||
422 | } | ||
423 | |||
424 | if ((fds[0].revents & POLLIN) == 0) { | ||
425 | if (fds[0].revents & POLLERR) { | ||
426 | // FIXME: links routinely go down; | ||
427 | // this shouldn't necessarily exit. | ||
428 | bb_error_msg("%s: poll error", intf); | ||
429 | if (ready) { | ||
430 | run(script, "deconfig", | ||
431 | intf, &ip); | ||
432 | } | ||
433 | return EXIT_FAILURE; | ||
434 | } | ||
435 | continue; | ||
436 | } | ||
437 | |||
438 | // read ARP packet | ||
439 | if (recv(fd, &p, sizeof (p), 0) < 0) { | ||
440 | why = "recv"; | ||
441 | goto bad; | ||
442 | } | ||
443 | if (p.hdr.ether_type != htons(ETHERTYPE_ARP)) | ||
444 | continue; | ||
445 | |||
446 | #ifdef DEBUG | ||
447 | { | ||
448 | struct ether_addr * sha = (struct ether_addr *) p.arp.arp_sha; | ||
449 | struct ether_addr * tha = (struct ether_addr *) p.arp.arp_tha; | ||
450 | struct in_addr * spa = (struct in_addr *) p.arp.arp_spa; | ||
451 | struct in_addr * tpa = (struct in_addr *) p.arp.arp_tpa; | ||
452 | VDBG("%s recv arp type=%d, op=%d,\n", | ||
453 | intf, ntohs(p.hdr.ether_type), | ||
454 | ntohs(p.arp.arp_op)); | ||
455 | VDBG("\tsource=%s %s\n", | ||
456 | ether_ntoa(sha), | ||
457 | inet_ntoa(*spa)); | ||
458 | VDBG("\ttarget=%s %s\n", | ||
459 | ether_ntoa(tha), | ||
460 | inet_ntoa(*tpa)); | ||
461 | } | ||
462 | #endif | ||
463 | if (p.arp.arp_op != htons(ARPOP_REQUEST) | ||
464 | && p.arp.arp_op != htons(ARPOP_REPLY)) | ||
465 | continue; | ||
466 | |||
467 | if (memcmp(p.arp.arp_spa, &ip.s_addr, sizeof(struct in_addr)) == 0 && | ||
468 | memcmp(ð_addr, &p.arp.arp_sha, ETH_ALEN) != 0) { | ||
469 | source_ip_conflict = 1; | ||
470 | } | ||
471 | if (memcmp(p.arp.arp_tpa, &ip.s_addr, sizeof(struct in_addr)) == 0 && | ||
472 | p.arp.arp_op == htons(ARPOP_REQUEST) && | ||
473 | memcmp(ð_addr, &p.arp.arp_tha, ETH_ALEN) != 0) { | ||
474 | target_ip_conflict = 1; | ||
475 | } | ||
476 | |||
477 | VDBG("state = %d, source ip conflict = %d, target ip conflict = %d\n", | ||
478 | state, source_ip_conflict, target_ip_conflict); | ||
479 | switch (state) { | ||
480 | case PROBE: | ||
481 | case ANNOUNCE: | ||
482 | // When probing or announcing, check for source IP conflicts | ||
483 | // and other hosts doing ARP probes (target IP conflicts). | ||
484 | if (source_ip_conflict || target_ip_conflict) { | ||
485 | conflicts++; | ||
486 | if (conflicts >= MAX_CONFLICTS) { | ||
487 | VDBG("%s ratelimit\n", intf); | ||
488 | timeout = RATE_LIMIT_INTERVAL * 1000; | ||
489 | state = RATE_LIMIT_PROBE; | ||
490 | } | ||
491 | |||
492 | // restart the whole protocol | ||
493 | pick(&ip); | ||
494 | timeout = 0; | ||
495 | nprobes = 0; | ||
496 | nclaims = 0; | ||
497 | } | ||
498 | break; | ||
499 | case MONITOR: | ||
500 | // If a conflict, we try to defend with a single ARP probe. | ||
501 | if (source_ip_conflict) { | ||
502 | VDBG("monitor conflict -- defending\n"); | ||
503 | state = DEFEND; | ||
504 | timeout = DEFEND_INTERVAL * 1000; | ||
505 | arp(fd, &saddr, | ||
506 | ARPOP_REQUEST, | ||
507 | ð_addr, ip, | ||
508 | ð_addr, ip); | ||
509 | } | ||
510 | break; | ||
511 | case DEFEND: | ||
512 | // Well, we tried. Start over (on conflict). | ||
513 | if (source_ip_conflict) { | ||
514 | state = PROBE; | ||
515 | VDBG("defend conflict -- starting over\n"); | ||
516 | ready = 0; | ||
517 | run(script, "deconfig", intf, &ip); | ||
518 | |||
519 | // restart the whole protocol | ||
520 | pick(&ip); | ||
521 | timeout = 0; | ||
522 | nprobes = 0; | ||
523 | nclaims = 0; | ||
524 | } | ||
525 | break; | ||
526 | default: | ||
527 | // Invalid, should never happen. Restart the whole protocol. | ||
528 | VDBG("invalid state -- starting over\n"); | ||
529 | state = PROBE; | ||
530 | pick(&ip); | ||
531 | timeout = 0; | ||
532 | nprobes = 0; | ||
533 | nclaims = 0; | ||
534 | break; | ||
535 | } // switch state | ||
536 | |||
537 | break; // case 1 (packets arriving) | ||
538 | default: | ||
539 | why = "poll"; | ||
540 | goto bad; | ||
541 | } // switch poll | ||
542 | } | ||
543 | bad: | ||
544 | bb_perror_msg("%s, %s", intf, why); | ||
545 | return EXIT_FAILURE; | ||
546 | } | ||