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43#include "libbb.h"
44
45#include "fix_u32.h"
46#include <linux/if.h>
47#include <linux/mii.h>
48#include <linux/ethtool.h>
49#ifdef HAVE_NET_ETHERNET_H
50
51
52
53
54
55
56
57
58
59
60
61#endif
62#include <linux/netlink.h>
63#include <linux/rtnetlink.h>
64#include <linux/sockios.h>
65#include <syslog.h>
66
67#define __user
68#include <linux/wireless.h>
69
70#ifndef ETH_ALEN
71# define ETH_ALEN 6
72#endif
73
74
75
76
77
78
79
80
81
82
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84
85
86
87
88
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90
91
92
93#define IFPLUGD_ENV_PREVIOUS "IFPLUGD_PREVIOUS"
94#define IFPLUGD_ENV_CURRENT "IFPLUGD_CURRENT"
95
96enum {
97 FLAG_NO_AUTO = 1 << 0,
98 FLAG_NO_DAEMON = 1 << 1,
99 FLAG_NO_SYSLOG = 1 << 2,
100 FLAG_IGNORE_FAIL = 1 << 3,
101 FLAG_IGNORE_FAIL_POSITIVE = 1 << 4,
102 FLAG_IFACE = 1 << 5,
103 FLAG_RUN = 1 << 6,
104 FLAG_IGNORE_RETVAL = 1 << 7,
105 FLAG_POLL_TIME = 1 << 8,
106 FLAG_DELAY_UP = 1 << 9,
107 FLAG_DELAY_DOWN = 1 << 10,
108 FLAG_API_MODE = 1 << 11,
109 FLAG_NO_STARTUP = 1 << 12,
110 FLAG_NO_SHUTDOWN = 1 << 13,
111 FLAG_INITIAL_DOWN = 1 << 14,
112 FLAG_EXTRA_ARG = 1 << 15,
113 FLAG_MONITOR = 1 << 16,
114#if ENABLE_FEATURE_PIDFILE
115 FLAG_KILL = 1 << 17,
116#endif
117};
118#if ENABLE_FEATURE_PIDFILE
119# define OPTION_STR "+ansfFi:r:It:+u:+d:+m:pqlx:Mk"
120#else
121# define OPTION_STR "+ansfFi:r:It:+u:+d:+m:pqlx:M"
122#endif
123
124enum {
125 IFSTATUS_ERR = -1,
126 IFSTATUS_DOWN = 0,
127 IFSTATUS_UP = 1,
128};
129
130enum {
131 ioctl_fd = 3,
132 netlink_fd = 4,
133};
134
135struct globals {
136 smallint iface_last_status;
137 smallint iface_prev_status;
138 smallint iface_exists;
139 smallint api_method_num;
140
141
142 unsigned poll_time;
143 unsigned delay_up;
144 unsigned delay_down;
145
146 const char *iface;
147 const char *api_mode;
148 const char *script_name;
149 const char *extra_arg;
150};
151#define G (*ptr_to_globals)
152#define INIT_G() do { \
153 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
154 G.iface_last_status = -1; \
155 G.iface_exists = 1; \
156 G.poll_time = 1; \
157 G.delay_down = 5; \
158 G.iface = "eth0"; \
159 G.api_mode = "a"; \
160 G.script_name = "/etc/ifplugd/ifplugd.action"; \
161} while (0)
162
163
164
165
166static void set_ifreq_to_ifname(struct ifreq *ifreq)
167{
168 memset(ifreq, 0, sizeof(struct ifreq));
169 strncpy_IFNAMSIZ(ifreq->ifr_name, G.iface);
170}
171
172static int network_ioctl(int request, void* data, const char *errmsg)
173{
174 int r = ioctl(ioctl_fd, request, data);
175 if (r < 0 && errmsg)
176 bb_perror_msg("%s failed", errmsg);
177 return r;
178}
179
180
181
182static smallint detect_link_mii(void)
183{
184
185 char buf[sizeof(struct ifreq)];
186 struct ifreq *const ifreq = (void *)buf;
187
188 struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
189
190 set_ifreq_to_ifname(ifreq);
191
192 if (network_ioctl(SIOCGMIIPHY, ifreq, "SIOCGMIIPHY") < 0) {
193 return IFSTATUS_ERR;
194 }
195
196 mii->reg_num = 1;
197
198 if (network_ioctl(SIOCGMIIREG, ifreq, "SIOCGMIIREG") < 0) {
199 return IFSTATUS_ERR;
200 }
201
202 return (mii->val_out & 0x0004) ? IFSTATUS_UP : IFSTATUS_DOWN;
203}
204
205static smallint detect_link_priv(void)
206{
207
208 char buf[sizeof(struct ifreq)];
209 struct ifreq *const ifreq = (void *)buf;
210
211 struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
212
213 set_ifreq_to_ifname(ifreq);
214
215 if (network_ioctl(SIOCDEVPRIVATE, ifreq, "SIOCDEVPRIVATE") < 0) {
216 return IFSTATUS_ERR;
217 }
218
219 mii->reg_num = 1;
220
221 if (network_ioctl(SIOCDEVPRIVATE+1, ifreq, "SIOCDEVPRIVATE+1") < 0) {
222 return IFSTATUS_ERR;
223 }
224
225 return (mii->val_out & 0x0004) ? IFSTATUS_UP : IFSTATUS_DOWN;
226}
227
228static smallint detect_link_ethtool(void)
229{
230 struct ifreq ifreq;
231 struct ethtool_value edata;
232
233 set_ifreq_to_ifname(&ifreq);
234
235 edata.cmd = ETHTOOL_GLINK;
236 ifreq.ifr_data = (void*) &edata;
237
238 if (network_ioctl(SIOCETHTOOL, &ifreq, "ETHTOOL_GLINK") < 0) {
239 return IFSTATUS_ERR;
240 }
241
242 return edata.data ? IFSTATUS_UP : IFSTATUS_DOWN;
243}
244
245static smallint detect_link_iff(void)
246{
247 struct ifreq ifreq;
248
249 set_ifreq_to_ifname(&ifreq);
250
251 if (network_ioctl(SIOCGIFFLAGS, &ifreq, "SIOCGIFFLAGS") < 0) {
252 return IFSTATUS_ERR;
253 }
254
255
256
257
258
259
260
261 if (!(ifreq.ifr_flags & IFF_UP) && G.iface_last_status != IFSTATUS_ERR)
262 return G.iface_last_status;
263
264 return (ifreq.ifr_flags & IFF_RUNNING) ? IFSTATUS_UP : IFSTATUS_DOWN;
265}
266
267static smallint detect_link_wlan(void)
268{
269 int i;
270 struct iwreq iwrequest;
271 uint8_t mac[ETH_ALEN];
272
273 memset(&iwrequest, 0, sizeof(iwrequest));
274 strncpy_IFNAMSIZ(iwrequest.ifr_ifrn.ifrn_name, G.iface);
275
276 if (network_ioctl(SIOCGIWAP, &iwrequest, "SIOCGIWAP") < 0) {
277 return IFSTATUS_ERR;
278 }
279
280 memcpy(mac, &iwrequest.u.ap_addr.sa_data, ETH_ALEN);
281
282 if (mac[0] == 0xFF || mac[0] == 0x44 || mac[0] == 0x00) {
283 for (i = 1; i < ETH_ALEN; ++i) {
284 if (mac[i] != mac[0])
285 return IFSTATUS_UP;
286 }
287 return IFSTATUS_DOWN;
288 }
289
290 return IFSTATUS_UP;
291}
292
293enum {
294 API_ETHTOOL,
295 API_MII,
296 API_PRIVATE,
297 API_WLAN,
298 API_IFF,
299 API_AUTO,
300};
301
302static const char api_modes[] ALIGN1 = "empwia";
303
304static const struct {
305 const char *name;
306 smallint (*func)(void);
307} method_table[] ALIGN_PTR = {
308 { "SIOCETHTOOL" , &detect_link_ethtool },
309 { "SIOCGMIIPHY" , &detect_link_mii },
310 { "SIOCDEVPRIVATE" , &detect_link_priv },
311 { "wireless extension", &detect_link_wlan },
312 { "IFF_RUNNING" , &detect_link_iff },
313};
314
315static const char *strstatus(int status)
316{
317 if (status == IFSTATUS_ERR)
318 return "error";
319 return "down\0up" + (status * 5);
320}
321
322static int run_script(const char *action)
323{
324 char *env_PREVIOUS, *env_CURRENT;
325 char *argv[5];
326 int r;
327
328 bb_info_msg("executing '%s %s %s'", G.script_name, G.iface, action);
329
330 argv[0] = (char*) G.script_name;
331 argv[1] = (char*) G.iface;
332 argv[2] = (char*) action;
333 argv[3] = (char*) G.extra_arg;
334 argv[4] = NULL;
335
336 env_PREVIOUS = xasprintf("%s=%s", IFPLUGD_ENV_PREVIOUS, strstatus(G.iface_prev_status));
337 putenv(env_PREVIOUS);
338 env_CURRENT = xasprintf("%s=%s", IFPLUGD_ENV_CURRENT, strstatus(G.iface_last_status));
339 putenv(env_CURRENT);
340
341
342 r = spawn_and_wait(argv);
343
344 bb_unsetenv_and_free(env_PREVIOUS);
345 bb_unsetenv_and_free(env_CURRENT);
346
347 bb_info_msg("exit code: %d", r & 0xff);
348 return (option_mask32 & FLAG_IGNORE_RETVAL) ? 0 : r;
349}
350
351static void up_iface(void)
352{
353 struct ifreq ifrequest;
354
355 if (!G.iface_exists)
356 return;
357
358 set_ifreq_to_ifname(&ifrequest);
359 if (network_ioctl(SIOCGIFFLAGS, &ifrequest, "getting interface flags") < 0) {
360 G.iface_exists = 0;
361 return;
362 }
363
364 if (!(ifrequest.ifr_flags & IFF_UP)) {
365 ifrequest.ifr_flags |= IFF_UP;
366
367 bb_simple_info_msg("upping interface");
368 if (network_ioctl(SIOCSIFFLAGS, &ifrequest, "setting interface flags") < 0) {
369 if (errno != ENODEV && errno != EADDRNOTAVAIL)
370 xfunc_die();
371 G.iface_exists = 0;
372 return;
373 }
374 }
375
376#if 0
377 if (network_ioctl(SIOCGIFADDR, &ifrequest, "can't get interface address") < 0) {
378 } else if (ifrequest.ifr_addr.sa_family != AF_INET) {
379 bb_perror_msg("the interface is not IP-based");
380 } else {
381 ((struct sockaddr_in*)(&ifrequest.ifr_addr))->sin_addr.s_addr = INADDR_ANY;
382 network_ioctl(SIOCSIFADDR, &ifrequest, "can't set interface address");
383 }
384 network_ioctl(SIOCGIFFLAGS, &ifrequest, "can't get interface flags");
385#endif
386}
387
388static void maybe_up_new_iface(void)
389{
390 if (!(option_mask32 & FLAG_NO_AUTO))
391 up_iface();
392
393#if 0
394 struct ifreq ifrequest;
395 struct ethtool_drvinfo driver_info;
396
397 set_ifreq_to_ifname(&ifrequest);
398 driver_info.cmd = ETHTOOL_GDRVINFO;
399 ifrequest.ifr_data = &driver_info;
400 if (network_ioctl(SIOCETHTOOL, &ifrequest, NULL) == 0) {
401 char buf[sizeof("/xx:xx:xx:xx:xx:xx")];
402
403
404 buf[0] = '\0';
405 set_ifreq_to_ifname(&ifrequest);
406 if (network_ioctl(SIOCGIFHWADDR, &ifrequest, NULL) == 0) {
407 sprintf(buf, "/%02X:%02X:%02X:%02X:%02X:%02X",
408 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[0]),
409 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[1]),
410 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[2]),
411 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[3]),
412 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[4]),
413 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[5]));
414 }
415
416 bb_info_msg("using interface %s%s with driver<%s> (version: %s)",
417 G.iface, buf, driver_info.driver, driver_info.version);
418 }
419#endif
420 if (G.api_mode[0] == 'a')
421 G.api_method_num = API_AUTO;
422}
423
424static smallint detect_link(void)
425{
426 smallint status;
427
428 if (!G.iface_exists)
429 return (option_mask32 & FLAG_MONITOR) ? IFSTATUS_DOWN : IFSTATUS_ERR;
430
431
432
433
434
435 if (!(option_mask32 & FLAG_NO_AUTO))
436 up_iface();
437
438 if (G.api_method_num == API_AUTO) {
439 int i;
440 smallint sv_logmode;
441
442 sv_logmode = logmode;
443 for (i = 0; i < ARRAY_SIZE(method_table); i++) {
444 logmode = LOGMODE_NONE;
445 status = method_table[i].func();
446 logmode = sv_logmode;
447 if (status != IFSTATUS_ERR) {
448 G.api_method_num = i;
449 bb_info_msg("using %s detection mode", method_table[i].name);
450 break;
451 }
452 }
453 } else {
454 status = method_table[G.api_method_num].func();
455 }
456
457 if (status == IFSTATUS_ERR) {
458 if (option_mask32 & FLAG_IGNORE_FAIL)
459 status = IFSTATUS_DOWN;
460 else if (option_mask32 & FLAG_IGNORE_FAIL_POSITIVE)
461 status = IFSTATUS_UP;
462 else if (G.api_mode[0] == 'a')
463 bb_simple_error_msg("can't detect link status");
464 }
465
466 if (status != G.iface_last_status) {
467 G.iface_prev_status = G.iface_last_status;
468 G.iface_last_status = status;
469 }
470
471 return status;
472}
473
474static NOINLINE int check_existence_through_netlink(void)
475{
476 int iface_len;
477
478
479
480
481 enum { BUF_SIZE = 8 * 1024 };
482 char *replybuf = xmalloc(BUF_SIZE);
483
484 iface_len = strlen(G.iface);
485 while (1) {
486 struct nlmsghdr *mhdr;
487 ssize_t bytes;
488
489 bytes = recv(netlink_fd, replybuf, BUF_SIZE, MSG_DONTWAIT);
490 if (bytes < 0) {
491 if (errno == EAGAIN)
492 goto ret;
493 if (errno == EINTR)
494 continue;
495 bb_simple_perror_msg("netlink: recv");
496 return -1;
497 }
498
499 mhdr = (struct nlmsghdr*)replybuf;
500 while (bytes > 0) {
501 if (!NLMSG_OK(mhdr, bytes)) {
502 bb_simple_error_msg("netlink packet too small or truncated");
503 return -1;
504 }
505
506 if (mhdr->nlmsg_type == RTM_NEWLINK || mhdr->nlmsg_type == RTM_DELLINK) {
507 struct rtattr *attr;
508 int attr_len;
509
510 if (mhdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifinfomsg))) {
511 bb_simple_error_msg("netlink packet too small or truncated");
512 return -1;
513 }
514
515 attr = IFLA_RTA(NLMSG_DATA(mhdr));
516 attr_len = IFLA_PAYLOAD(mhdr);
517
518 while (RTA_OK(attr, attr_len)) {
519 if (attr->rta_type == IFLA_IFNAME) {
520 int len = RTA_PAYLOAD(attr);
521 if (len > IFNAMSIZ)
522 len = IFNAMSIZ;
523 if (iface_len <= len
524 && strncmp(G.iface, RTA_DATA(attr), len) == 0
525 ) {
526 G.iface_exists = (mhdr->nlmsg_type == RTM_NEWLINK);
527 }
528 }
529 attr = RTA_NEXT(attr, attr_len);
530 }
531 }
532
533 mhdr = NLMSG_NEXT(mhdr, bytes);
534 }
535 }
536
537 ret:
538 free(replybuf);
539 return G.iface_exists;
540}
541
542#if ENABLE_FEATURE_PIDFILE
543static NOINLINE pid_t read_pid(const char *filename)
544{
545 int len;
546 char buf[128];
547
548 len = open_read_close(filename, buf, 127);
549 if (len > 0) {
550 buf[len] = '\0';
551
552 return bb_strtoul(buf, NULL, 10);
553 }
554 return 0;
555}
556#endif
557
558int ifplugd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
559int ifplugd_main(int argc UNUSED_PARAM, char **argv)
560{
561 int iface_status;
562 int delay_time;
563 const char *iface_status_str;
564 struct pollfd netlink_pollfd[1];
565 unsigned opts;
566 const char *api_mode_found;
567#if ENABLE_FEATURE_PIDFILE
568 char *pidfile_name;
569 pid_t pid_from_pidfile;
570#endif
571
572 INIT_G();
573
574 opts = getopt32(argv, OPTION_STR,
575 &G.iface, &G.script_name, &G.poll_time, &G.delay_up,
576 &G.delay_down, &G.api_mode, &G.extra_arg);
577 G.poll_time *= 1000;
578
579 applet_name = xasprintf("ifplugd(%s)", G.iface);
580
581#if ENABLE_FEATURE_PIDFILE
582 pidfile_name = xasprintf(CONFIG_PID_FILE_PATH "/ifplugd.%s.pid", G.iface);
583 pid_from_pidfile = read_pid(pidfile_name);
584
585 if (opts & FLAG_KILL) {
586 if (pid_from_pidfile > 0)
587
588 kill(pid_from_pidfile, SIGINT);
589 return EXIT_SUCCESS;
590 }
591
592 if (pid_from_pidfile > 0 && kill(pid_from_pidfile, 0) == 0)
593 bb_simple_error_msg_and_die("daemon already running");
594#endif
595
596 api_mode_found = strchr(api_modes, G.api_mode[0]);
597 if (!api_mode_found)
598 bb_error_msg_and_die("unknown API mode '%s'", G.api_mode);
599 G.api_method_num = api_mode_found - api_modes;
600
601 if (!(opts & FLAG_NO_DAEMON))
602 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
603
604 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), ioctl_fd);
605 if (opts & FLAG_MONITOR) {
606 int fd = create_and_bind_to_netlink(NETLINK_ROUTE, RTMGRP_LINK, 0);
607 xmove_fd(fd, netlink_fd);
608 }
609
610 write_pidfile(pidfile_name);
611
612
613 if (!(opts & FLAG_NO_SYSLOG)) {
614 openlog(applet_name, 0, LOG_DAEMON);
615 logmode |= LOGMODE_SYSLOG;
616 }
617
618 bb_signals(0
619 | (1 << SIGINT )
620 | (1 << SIGTERM)
621 | (1 << SIGQUIT)
622 | (1 << SIGHUP )
623
624 , record_signo);
625
626 bb_info_msg("started: %s", bb_banner);
627
628 if (opts & FLAG_MONITOR) {
629 struct ifreq ifrequest;
630 set_ifreq_to_ifname(&ifrequest);
631 G.iface_exists = (network_ioctl(SIOCGIFINDEX, &ifrequest, NULL) == 0);
632 }
633
634 if (G.iface_exists)
635 maybe_up_new_iface();
636
637 iface_status = detect_link();
638 if (iface_status == IFSTATUS_ERR)
639 goto exiting;
640 iface_status_str = strstatus(iface_status);
641
642 if (opts & FLAG_MONITOR) {
643 bb_info_msg("interface %s",
644 G.iface_exists ? "exists"
645 : "doesn't exist, waiting");
646 }
647
648
649
650 if (G.iface_exists) {
651 bb_info_msg("link is %s", iface_status_str);
652 }
653
654 if ((!(opts & FLAG_NO_STARTUP)
655 && iface_status == IFSTATUS_UP
656 )
657 || (opts & FLAG_INITIAL_DOWN)
658 ) {
659 if (run_script(iface_status_str) != 0)
660 goto exiting;
661 }
662
663
664 netlink_pollfd[0].fd = netlink_fd;
665 netlink_pollfd[0].events = POLLIN;
666 delay_time = 0;
667 while (1) {
668 int iface_status_old;
669
670 switch (bb_got_signal) {
671 case SIGINT:
672 case SIGTERM:
673 bb_got_signal = 0;
674 goto cleanup;
675 case SIGQUIT:
676 bb_got_signal = 0;
677 goto exiting;
678 default:
679 bb_got_signal = 0;
680
681 case 0:
682 break;
683 }
684
685 if (poll(netlink_pollfd,
686 (opts & FLAG_MONITOR) ? 1 : 0,
687 G.poll_time
688 ) < 0
689 ) {
690 if (errno == EINTR)
691 continue;
692 bb_simple_perror_msg("poll");
693 goto exiting;
694 }
695
696 if ((opts & FLAG_MONITOR)
697 && (netlink_pollfd[0].revents & POLLIN)
698 ) {
699 int iface_exists_old;
700
701 iface_exists_old = G.iface_exists;
702 G.iface_exists = check_existence_through_netlink();
703 if (G.iface_exists < 0)
704 goto exiting;
705 if (iface_exists_old != G.iface_exists) {
706 bb_info_msg("interface %sappeared",
707 G.iface_exists ? "" : "dis");
708 if (G.iface_exists)
709 maybe_up_new_iface();
710 }
711 }
712
713
714 iface_status_old = iface_status;
715 iface_status = detect_link();
716 if (iface_status == IFSTATUS_ERR) {
717 if (!(opts & FLAG_MONITOR))
718 goto exiting;
719 iface_status = IFSTATUS_DOWN;
720 }
721 iface_status_str = strstatus(iface_status);
722
723 if (iface_status_old != iface_status) {
724 bb_info_msg("link is %s", iface_status_str);
725
726 if (delay_time) {
727
728
729 delay_time = 0;
730 } else {
731 delay_time = monotonic_sec();
732 if (iface_status == IFSTATUS_UP)
733 delay_time += G.delay_up;
734 if (iface_status == IFSTATUS_DOWN)
735 delay_time += G.delay_down;
736#if 0
737 if (delay_time == 0) {
738 sleep1();
739 delay_time = 1;
740 }
741#endif
742 }
743 }
744
745 if (delay_time && (int)(monotonic_sec() - delay_time) >= 0) {
746 if (run_script(iface_status_str) != 0)
747 goto exiting;
748 delay_time = 0;
749 }
750 }
751
752 cleanup:
753 if (!(opts & FLAG_NO_SHUTDOWN)
754 && (iface_status == IFSTATUS_UP
755 || (iface_status == IFSTATUS_DOWN && delay_time)
756 )
757 ) {
758 setenv(IFPLUGD_ENV_PREVIOUS, strstatus(iface_status), 1);
759 setenv(IFPLUGD_ENV_CURRENT, strstatus(-1), 1);
760 run_script("down\0up");
761 }
762
763 exiting:
764 remove_pidfile(pidfile_name);
765 bb_simple_error_msg_and_die("exiting");
766}
767