source: MondoRescue/branches/3.3/mindi-busybox/networking/ifplugd.c@ 3621

Last change on this file since 3621 was 3621, checked in by Bruno Cornec, 7 years ago

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.
  • Property svn:eol-style set to native
File size: 19.9 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * ifplugd for busybox, based on ifplugd 0.28 (written by Lennart Poettering).
4 *
5 * Copyright (C) 2009 Maksym Kryzhanovskyy <xmaks@email.cz>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 */
9
10//usage:#define ifplugd_trivial_usage
11//usage: "[OPTIONS]"
12//usage:#define ifplugd_full_usage "\n\n"
13//usage: "Network interface plug detection daemon\n"
14//usage: "\n -n Don't daemonize"
15//usage: "\n -s Don't log to syslog"
16//usage: "\n -i IFACE Interface"
17//usage: "\n -f/-F Treat link detection error as link down/link up"
18//usage: "\n (otherwise exit on error)"
19//usage: "\n -a Don't up interface at each link probe"
20//usage: "\n -M Monitor creation/destruction of interface"
21//usage: "\n (otherwise it must exist)"
22//usage: "\n -r PROG Script to run"
23//usage: "\n -x ARG Extra argument for script"
24//usage: "\n -I Don't exit on nonzero exit code from script"
25//usage: "\n -p Don't run \"up\" script on startup"
26//usage: "\n -q Don't run \"down\" script on exit"
27//usage: "\n -l Always run script on startup"
28//usage: "\n -t SECS Poll time in seconds"
29//usage: "\n -u SECS Delay before running script after link up"
30//usage: "\n -d SECS Delay after link down"
31//usage: "\n -m MODE API mode (mii, priv, ethtool, wlan, iff, auto)"
32//usage: "\n -k Kill running daemon"
33
34#include "libbb.h"
35
36#include "fix_u32.h"
37#include <linux/if.h>
38#include <linux/mii.h>
39#include <linux/ethtool.h>
40#ifdef HAVE_NET_ETHERNET_H
41/* musl breakage:
42 * In file included from /usr/include/net/ethernet.h:10,
43 * from networking/ifplugd.c:41:
44 * /usr/include/netinet/if_ether.h:96: error: redefinition of 'struct ethhdr'
45 *
46 * Build succeeds without it on musl. Commented it out.
47 * If on your system you need it, consider removing <linux/ethtool.h>
48 * and copy-pasting its definitions here (<linux/ethtool.h> is what pulls in
49 * conflicting definition of struct ethhdr on musl).
50 */
51/* # include <net/ethernet.h> */
52#endif
53#include <linux/netlink.h>
54#include <linux/rtnetlink.h>
55#include <linux/sockios.h>
56#include <syslog.h>
57
58#define __user
59#include <linux/wireless.h>
60
61#ifndef ETH_ALEN
62# define ETH_ALEN 6
63#endif
64
65/*
66From initial port to busybox, removed most of the redundancy by
67converting implementation of a polymorphic interface to the strict
68functional style. The main role is run a script when link state
69changed, other activities like audio signal or detailed reports
70are on the script itself.
71
72One questionable point of the design is netlink usage:
73
74We have 1 second timeout by default to poll the link status,
75it is short enough so that there are no real benefits in
76using netlink to get "instantaneous" interface creation/deletion
77notifications. We can check for interface existence by just
78doing some fast ioctl using its name.
79
80Netlink code then can be just dropped (1k or more?)
81*/
82
83
84#define IFPLUGD_ENV_PREVIOUS "IFPLUGD_PREVIOUS"
85#define IFPLUGD_ENV_CURRENT "IFPLUGD_CURRENT"
86
87enum {
88 FLAG_NO_AUTO = 1 << 0, // -a, Do not enable interface automatically
89 FLAG_NO_DAEMON = 1 << 1, // -n, Do not daemonize
90 FLAG_NO_SYSLOG = 1 << 2, // -s, Do not use syslog, use stderr instead
91 FLAG_IGNORE_FAIL = 1 << 3, // -f, Ignore detection failure, retry instead (failure is treated as DOWN)
92 FLAG_IGNORE_FAIL_POSITIVE = 1 << 4, // -F, Ignore detection failure, retry instead (failure is treated as UP)
93 FLAG_IFACE = 1 << 5, // -i, Specify ethernet interface
94 FLAG_RUN = 1 << 6, // -r, Specify program to execute
95 FLAG_IGNORE_RETVAL = 1 << 7, // -I, Don't exit on nonzero return value of program executed
96 FLAG_POLL_TIME = 1 << 8, // -t, Specify poll time in seconds
97 FLAG_DELAY_UP = 1 << 9, // -u, Specify delay for configuring interface
98 FLAG_DELAY_DOWN = 1 << 10, // -d, Specify delay for deconfiguring interface
99 FLAG_API_MODE = 1 << 11, // -m, Force API mode (mii, priv, ethtool, wlan, auto)
100 FLAG_NO_STARTUP = 1 << 12, // -p, Don't run script on daemon startup
101 FLAG_NO_SHUTDOWN = 1 << 13, // -q, Don't run script on daemon quit
102 FLAG_INITIAL_DOWN = 1 << 14, // -l, Run "down" script on startup if no cable is detected
103 FLAG_EXTRA_ARG = 1 << 15, // -x, Specify an extra argument for action script
104 FLAG_MONITOR = 1 << 16, // -M, Use interface monitoring
105#if ENABLE_FEATURE_PIDFILE
106 FLAG_KILL = 1 << 17, // -k, Kill a running daemon
107#endif
108};
109#if ENABLE_FEATURE_PIDFILE
110# define OPTION_STR "+ansfFi:r:It:u:d:m:pqlx:Mk"
111#else
112# define OPTION_STR "+ansfFi:r:It:u:d:m:pqlx:M"
113#endif
114
115enum { // interface status
116 IFSTATUS_ERR = -1,
117 IFSTATUS_DOWN = 0,
118 IFSTATUS_UP = 1,
119};
120
121enum { // constant fds
122 ioctl_fd = 3,
123 netlink_fd = 4,
124};
125
126struct globals {
127 smallint iface_last_status;
128 smallint iface_prev_status;
129 smallint iface_exists;
130 smallint api_method_num;
131
132 /* Used in getopt32, must have sizeof == sizeof(int) */
133 unsigned poll_time;
134 unsigned delay_up;
135 unsigned delay_down;
136
137 const char *iface;
138 const char *api_mode;
139 const char *script_name;
140 const char *extra_arg;
141};
142#define G (*ptr_to_globals)
143#define INIT_G() do { \
144 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
145 G.iface_last_status = -1; \
146 G.iface_exists = 1; \
147 G.poll_time = 1; \
148 G.delay_down = 5; \
149 G.iface = "eth0"; \
150 G.api_mode = "a"; \
151 G.script_name = "/etc/ifplugd/ifplugd.action"; \
152} while (0)
153
154
155/* Utility routines */
156
157static void set_ifreq_to_ifname(struct ifreq *ifreq)
158{
159 memset(ifreq, 0, sizeof(struct ifreq));
160 strncpy_IFNAMSIZ(ifreq->ifr_name, G.iface);
161}
162
163static int network_ioctl(int request, void* data, const char *errmsg)
164{
165 int r = ioctl(ioctl_fd, request, data);
166 if (r < 0 && errmsg)
167 bb_perror_msg("%s failed", errmsg);
168 return r;
169}
170
171/* Link detection routines and table */
172
173static smallint detect_link_mii(void)
174{
175 /* char buffer instead of bona-fide struct avoids aliasing warning */
176 char buf[sizeof(struct ifreq)];
177 struct ifreq *const ifreq = (void *)buf;
178
179 struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
180
181 set_ifreq_to_ifname(ifreq);
182
183 if (network_ioctl(SIOCGMIIPHY, ifreq, "SIOCGMIIPHY") < 0) {
184 return IFSTATUS_ERR;
185 }
186
187 mii->reg_num = 1;
188
189 if (network_ioctl(SIOCGMIIREG, ifreq, "SIOCGMIIREG") < 0) {
190 return IFSTATUS_ERR;
191 }
192
193 return (mii->val_out & 0x0004) ? IFSTATUS_UP : IFSTATUS_DOWN;
194}
195
196static smallint detect_link_priv(void)
197{
198 /* char buffer instead of bona-fide struct avoids aliasing warning */
199 char buf[sizeof(struct ifreq)];
200 struct ifreq *const ifreq = (void *)buf;
201
202 struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
203
204 set_ifreq_to_ifname(ifreq);
205
206 if (network_ioctl(SIOCDEVPRIVATE, ifreq, "SIOCDEVPRIVATE") < 0) {
207 return IFSTATUS_ERR;
208 }
209
210 mii->reg_num = 1;
211
212 if (network_ioctl(SIOCDEVPRIVATE+1, ifreq, "SIOCDEVPRIVATE+1") < 0) {
213 return IFSTATUS_ERR;
214 }
215
216 return (mii->val_out & 0x0004) ? IFSTATUS_UP : IFSTATUS_DOWN;
217}
218
219static smallint detect_link_ethtool(void)
220{
221 struct ifreq ifreq;
222 struct ethtool_value edata;
223
224 set_ifreq_to_ifname(&ifreq);
225
226 edata.cmd = ETHTOOL_GLINK;
227 ifreq.ifr_data = (void*) &edata;
228
229 if (network_ioctl(SIOCETHTOOL, &ifreq, "ETHTOOL_GLINK") < 0) {
230 return IFSTATUS_ERR;
231 }
232
233 return edata.data ? IFSTATUS_UP : IFSTATUS_DOWN;
234}
235
236static smallint detect_link_iff(void)
237{
238 struct ifreq ifreq;
239
240 set_ifreq_to_ifname(&ifreq);
241
242 if (network_ioctl(SIOCGIFFLAGS, &ifreq, "SIOCGIFFLAGS") < 0) {
243 return IFSTATUS_ERR;
244 }
245
246 /* If IFF_UP is not set (interface is down), IFF_RUNNING is never set
247 * regardless of link status. Simply continue to report last status -
248 * no point in reporting spurious link downs if interface is disabled
249 * by admin. When/if it will be brought up,
250 * we'll report real link status.
251 */
252 if (!(ifreq.ifr_flags & IFF_UP) && G.iface_last_status != IFSTATUS_ERR)
253 return G.iface_last_status;
254
255 return (ifreq.ifr_flags & IFF_RUNNING) ? IFSTATUS_UP : IFSTATUS_DOWN;
256}
257
258static smallint detect_link_wlan(void)
259{
260 int i;
261 struct iwreq iwrequest;
262 uint8_t mac[ETH_ALEN];
263
264 memset(&iwrequest, 0, sizeof(iwrequest));
265 strncpy_IFNAMSIZ(iwrequest.ifr_ifrn.ifrn_name, G.iface);
266
267 if (network_ioctl(SIOCGIWAP, &iwrequest, "SIOCGIWAP") < 0) {
268 return IFSTATUS_ERR;
269 }
270
271 memcpy(mac, &iwrequest.u.ap_addr.sa_data, ETH_ALEN);
272
273 if (mac[0] == 0xFF || mac[0] == 0x44 || mac[0] == 0x00) {
274 for (i = 1; i < ETH_ALEN; ++i) {
275 if (mac[i] != mac[0])
276 return IFSTATUS_UP;
277 }
278 return IFSTATUS_DOWN;
279 }
280
281 return IFSTATUS_UP;
282}
283
284enum { // api mode
285 API_ETHTOOL, // 'e'
286 API_MII, // 'm'
287 API_PRIVATE, // 'p'
288 API_WLAN, // 'w'
289 API_IFF, // 'i'
290 API_AUTO, // 'a'
291};
292
293static const char api_modes[] ALIGN1 = "empwia";
294
295static const struct {
296 const char *name;
297 smallint (*func)(void);
298} method_table[] = {
299 { "SIOCETHTOOL" , &detect_link_ethtool },
300 { "SIOCGMIIPHY" , &detect_link_mii },
301 { "SIOCDEVPRIVATE" , &detect_link_priv },
302 { "wireless extension", &detect_link_wlan },
303 { "IFF_RUNNING" , &detect_link_iff },
304};
305
306static const char *strstatus(int status)
307{
308 if (status == IFSTATUS_ERR)
309 return "error";
310 return "down\0up" + (status * 5);
311}
312
313static int run_script(const char *action)
314{
315 char *env_PREVIOUS, *env_CURRENT;
316 char *argv[5];
317 int r;
318
319 bb_error_msg("executing '%s %s %s'", G.script_name, G.iface, action);
320
321 argv[0] = (char*) G.script_name;
322 argv[1] = (char*) G.iface;
323 argv[2] = (char*) action;
324 argv[3] = (char*) G.extra_arg;
325 argv[4] = NULL;
326
327 env_PREVIOUS = xasprintf("%s=%s", IFPLUGD_ENV_PREVIOUS, strstatus(G.iface_prev_status));
328 putenv(env_PREVIOUS);
329 env_CURRENT = xasprintf("%s=%s", IFPLUGD_ENV_CURRENT, strstatus(G.iface_last_status));
330 putenv(env_CURRENT);
331
332 /* r < 0 - can't exec, 0 <= r < 0x180 - exited, >=0x180 - killed by sig (r-0x180) */
333 r = spawn_and_wait(argv);
334
335 unsetenv(IFPLUGD_ENV_PREVIOUS);
336 unsetenv(IFPLUGD_ENV_CURRENT);
337 free(env_PREVIOUS);
338 free(env_CURRENT);
339
340 bb_error_msg("exit code: %d", r & 0xff);
341 return (option_mask32 & FLAG_IGNORE_RETVAL) ? 0 : r;
342}
343
344static void up_iface(void)
345{
346 struct ifreq ifrequest;
347
348 if (!G.iface_exists)
349 return;
350
351 set_ifreq_to_ifname(&ifrequest);
352 if (network_ioctl(SIOCGIFFLAGS, &ifrequest, "getting interface flags") < 0) {
353 G.iface_exists = 0;
354 return;
355 }
356
357 if (!(ifrequest.ifr_flags & IFF_UP)) {
358 ifrequest.ifr_flags |= IFF_UP;
359 /* Let user know we mess up with interface */
360 bb_error_msg("upping interface");
361 if (network_ioctl(SIOCSIFFLAGS, &ifrequest, "setting interface flags") < 0)
362 xfunc_die();
363 }
364
365#if 0 /* why do we mess with IP addr? It's not our business */
366 if (network_ioctl(SIOCGIFADDR, &ifrequest, "can't get interface address") < 0) {
367 } else if (ifrequest.ifr_addr.sa_family != AF_INET) {
368 bb_perror_msg("the interface is not IP-based");
369 } else {
370 ((struct sockaddr_in*)(&ifrequest.ifr_addr))->sin_addr.s_addr = INADDR_ANY;
371 network_ioctl(SIOCSIFADDR, &ifrequest, "can't set interface address");
372 }
373 network_ioctl(SIOCGIFFLAGS, &ifrequest, "can't get interface flags");
374#endif
375}
376
377static void maybe_up_new_iface(void)
378{
379 if (!(option_mask32 & FLAG_NO_AUTO))
380 up_iface();
381
382#if 0 /* bloat */
383 struct ifreq ifrequest;
384 struct ethtool_drvinfo driver_info;
385
386 set_ifreq_to_ifname(&ifrequest);
387 driver_info.cmd = ETHTOOL_GDRVINFO;
388 ifrequest.ifr_data = &driver_info;
389 if (network_ioctl(SIOCETHTOOL, &ifrequest, NULL) == 0) {
390 char buf[sizeof("/xx:xx:xx:xx:xx:xx")];
391
392 /* Get MAC */
393 buf[0] = '\0';
394 set_ifreq_to_ifname(&ifrequest);
395 if (network_ioctl(SIOCGIFHWADDR, &ifrequest, NULL) == 0) {
396 sprintf(buf, "/%02X:%02X:%02X:%02X:%02X:%02X",
397 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[0]),
398 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[1]),
399 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[2]),
400 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[3]),
401 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[4]),
402 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[5]));
403 }
404
405 bb_error_msg("using interface %s%s with driver<%s> (version: %s)",
406 G.iface, buf, driver_info.driver, driver_info.version);
407 }
408#endif
409 if (G.api_mode[0] == 'a')
410 G.api_method_num = API_AUTO;
411}
412
413static smallint detect_link(void)
414{
415 smallint status;
416
417 if (!G.iface_exists)
418 return (option_mask32 & FLAG_MONITOR) ? IFSTATUS_DOWN : IFSTATUS_ERR;
419
420 /* Some drivers can't detect link status when the interface is down.
421 * I imagine detect_link_iff() is the most vulnerable.
422 * That's why -a "noauto" in an option, not a hardwired behavior.
423 */
424 if (!(option_mask32 & FLAG_NO_AUTO))
425 up_iface();
426
427 if (G.api_method_num == API_AUTO) {
428 int i;
429 smallint sv_logmode;
430
431 sv_logmode = logmode;
432 for (i = 0; i < ARRAY_SIZE(method_table); i++) {
433 logmode = LOGMODE_NONE;
434 status = method_table[i].func();
435 logmode = sv_logmode;
436 if (status != IFSTATUS_ERR) {
437 G.api_method_num = i;
438 bb_error_msg("using %s detection mode", method_table[i].name);
439 break;
440 }
441 }
442 } else {
443 status = method_table[G.api_method_num].func();
444 }
445
446 if (status == IFSTATUS_ERR) {
447 if (option_mask32 & FLAG_IGNORE_FAIL)
448 status = IFSTATUS_DOWN;
449 else if (option_mask32 & FLAG_IGNORE_FAIL_POSITIVE)
450 status = IFSTATUS_UP;
451 else if (G.api_mode[0] == 'a')
452 bb_error_msg("can't detect link status");
453 }
454
455 if (status != G.iface_last_status) {
456 G.iface_prev_status = G.iface_last_status;
457 G.iface_last_status = status;
458 }
459
460 return status;
461}
462
463static NOINLINE int check_existence_through_netlink(void)
464{
465 int iface_len;
466 /* Buffer was 1K, but on linux-3.9.9 it was reported to be too small.
467 * netlink.h: "limit to 8K to avoid MSG_TRUNC when PAGE_SIZE is very large".
468 * Note: on error returns (-1) we exit, no need to free replybuf.
469 */
470 enum { BUF_SIZE = 8 * 1024 };
471 char *replybuf = xmalloc(BUF_SIZE);
472
473 iface_len = strlen(G.iface);
474 while (1) {
475 struct nlmsghdr *mhdr;
476 ssize_t bytes;
477
478 bytes = recv(netlink_fd, replybuf, BUF_SIZE, MSG_DONTWAIT);
479 if (bytes < 0) {
480 if (errno == EAGAIN)
481 goto ret;
482 if (errno == EINTR)
483 continue;
484 bb_perror_msg("netlink: recv");
485 return -1;
486 }
487
488 mhdr = (struct nlmsghdr*)replybuf;
489 while (bytes > 0) {
490 if (!NLMSG_OK(mhdr, bytes)) {
491 bb_error_msg("netlink packet too small or truncated");
492 return -1;
493 }
494
495 if (mhdr->nlmsg_type == RTM_NEWLINK || mhdr->nlmsg_type == RTM_DELLINK) {
496 struct rtattr *attr;
497 int attr_len;
498
499 if (mhdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifinfomsg))) {
500 bb_error_msg("netlink packet too small or truncated");
501 return -1;
502 }
503
504 attr = IFLA_RTA(NLMSG_DATA(mhdr));
505 attr_len = IFLA_PAYLOAD(mhdr);
506
507 while (RTA_OK(attr, attr_len)) {
508 if (attr->rta_type == IFLA_IFNAME) {
509 int len = RTA_PAYLOAD(attr);
510 if (len > IFNAMSIZ)
511 len = IFNAMSIZ;
512 if (iface_len <= len
513 && strncmp(G.iface, RTA_DATA(attr), len) == 0
514 ) {
515 G.iface_exists = (mhdr->nlmsg_type == RTM_NEWLINK);
516 }
517 }
518 attr = RTA_NEXT(attr, attr_len);
519 }
520 }
521
522 mhdr = NLMSG_NEXT(mhdr, bytes);
523 }
524 }
525
526 ret:
527 free(replybuf);
528 return G.iface_exists;
529}
530
531#if ENABLE_FEATURE_PIDFILE
532static NOINLINE pid_t read_pid(const char *filename)
533{
534 int len;
535 char buf[128];
536
537 len = open_read_close(filename, buf, 127);
538 if (len > 0) {
539 buf[len] = '\0';
540 /* returns ULONG_MAX on error => -1 */
541 return bb_strtoul(buf, NULL, 10);
542 }
543 return 0;
544}
545#endif
546
547int ifplugd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
548int ifplugd_main(int argc UNUSED_PARAM, char **argv)
549{
550 int iface_status;
551 int delay_time;
552 const char *iface_status_str;
553 struct pollfd netlink_pollfd[1];
554 unsigned opts;
555 const char *api_mode_found;
556#if ENABLE_FEATURE_PIDFILE
557 char *pidfile_name;
558 pid_t pid_from_pidfile;
559#endif
560
561 INIT_G();
562
563 opt_complementary = "t+:u+:d+";
564 opts = getopt32(argv, OPTION_STR,
565 &G.iface, &G.script_name, &G.poll_time, &G.delay_up,
566 &G.delay_down, &G.api_mode, &G.extra_arg);
567 G.poll_time *= 1000;
568
569 applet_name = xasprintf("ifplugd(%s)", G.iface);
570
571#if ENABLE_FEATURE_PIDFILE
572 pidfile_name = xasprintf(CONFIG_PID_FILE_PATH "/ifplugd.%s.pid", G.iface);
573 pid_from_pidfile = read_pid(pidfile_name);
574
575 if (opts & FLAG_KILL) {
576 if (pid_from_pidfile > 0)
577 /* Upstream tool use SIGINT for -k */
578 kill(pid_from_pidfile, SIGINT);
579 return EXIT_SUCCESS;
580 }
581
582 if (pid_from_pidfile > 0 && kill(pid_from_pidfile, 0) == 0)
583 bb_error_msg_and_die("daemon already running");
584#endif
585
586 api_mode_found = strchr(api_modes, G.api_mode[0]);
587 if (!api_mode_found)
588 bb_error_msg_and_die("unknown API mode '%s'", G.api_mode);
589 G.api_method_num = api_mode_found - api_modes;
590
591 if (!(opts & FLAG_NO_DAEMON))
592 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
593
594 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), ioctl_fd);
595 if (opts & FLAG_MONITOR) {
596 struct sockaddr_nl addr;
597 int fd = xsocket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
598
599 memset(&addr, 0, sizeof(addr));
600 addr.nl_family = AF_NETLINK;
601 addr.nl_groups = RTMGRP_LINK;
602 addr.nl_pid = getpid();
603
604 xbind(fd, (struct sockaddr*)&addr, sizeof(addr));
605 xmove_fd(fd, netlink_fd);
606 }
607
608 write_pidfile(pidfile_name);
609
610 /* this can't be moved before socket creation */
611 if (!(opts & FLAG_NO_SYSLOG)) {
612 openlog(applet_name, 0, LOG_DAEMON);
613 logmode |= LOGMODE_SYSLOG;
614 }
615
616 bb_signals(0
617 | (1 << SIGINT )
618 | (1 << SIGTERM)
619 | (1 << SIGQUIT)
620 | (1 << SIGHUP ) /* why we ignore it? */
621 /* | (1 << SIGCHLD) - run_script does not use it anymore */
622 , record_signo);
623
624 bb_error_msg("started: %s", bb_banner);
625
626 if (opts & FLAG_MONITOR) {
627 struct ifreq ifrequest;
628 set_ifreq_to_ifname(&ifrequest);
629 G.iface_exists = (network_ioctl(SIOCGIFINDEX, &ifrequest, NULL) == 0);
630 }
631
632 if (G.iface_exists)
633 maybe_up_new_iface();
634
635 iface_status = detect_link();
636 if (iface_status == IFSTATUS_ERR)
637 goto exiting;
638 iface_status_str = strstatus(iface_status);
639
640 if (opts & FLAG_MONITOR) {
641 bb_error_msg("interface %s",
642 G.iface_exists ? "exists"
643 : "doesn't exist, waiting");
644 }
645 /* else we assume it always exists, but don't mislead user
646 * by potentially lying that it really exists */
647
648 if (G.iface_exists) {
649 bb_error_msg("link is %s", iface_status_str);
650 }
651
652 if ((!(opts & FLAG_NO_STARTUP)
653 && iface_status == IFSTATUS_UP
654 )
655 || (opts & FLAG_INITIAL_DOWN)
656 ) {
657 if (run_script(iface_status_str) != 0)
658 goto exiting;
659 }
660
661 /* Main loop */
662 netlink_pollfd[0].fd = netlink_fd;
663 netlink_pollfd[0].events = POLLIN;
664 delay_time = 0;
665 while (1) {
666 int iface_status_old;
667
668 switch (bb_got_signal) {
669 case SIGINT:
670 case SIGTERM:
671 bb_got_signal = 0;
672 goto cleanup;
673 case SIGQUIT:
674 bb_got_signal = 0;
675 goto exiting;
676 default:
677 bb_got_signal = 0;
678 break;
679 }
680
681 if (poll(netlink_pollfd,
682 (opts & FLAG_MONITOR) ? 1 : 0,
683 G.poll_time
684 ) < 0
685 ) {
686 if (errno == EINTR)
687 continue;
688 bb_perror_msg("poll");
689 goto exiting;
690 }
691
692 if ((opts & FLAG_MONITOR)
693 && (netlink_pollfd[0].revents & POLLIN)
694 ) {
695 int iface_exists_old;
696
697 iface_exists_old = G.iface_exists;
698 G.iface_exists = check_existence_through_netlink();
699 if (G.iface_exists < 0) /* error */
700 goto exiting;
701 if (iface_exists_old != G.iface_exists) {
702 bb_error_msg("interface %sappeared",
703 G.iface_exists ? "" : "dis");
704 if (G.iface_exists)
705 maybe_up_new_iface();
706 }
707 }
708
709 /* note: if !G.iface_exists, returns DOWN */
710 iface_status_old = iface_status;
711 iface_status = detect_link();
712 if (iface_status == IFSTATUS_ERR) {
713 if (!(opts & FLAG_MONITOR))
714 goto exiting;
715 iface_status = IFSTATUS_DOWN;
716 }
717 iface_status_str = strstatus(iface_status);
718
719 if (iface_status_old != iface_status) {
720 bb_error_msg("link is %s", iface_status_str);
721
722 if (delay_time) {
723 /* link restored its old status before
724 * we ran script. don't run the script: */
725 delay_time = 0;
726 } else {
727 delay_time = monotonic_sec();
728 if (iface_status == IFSTATUS_UP)
729 delay_time += G.delay_up;
730 if (iface_status == IFSTATUS_DOWN)
731 delay_time += G.delay_down;
732#if 0 /* if you are back in 1970... */
733 if (delay_time == 0) {
734 sleep(1);
735 delay_time = 1;
736 }
737#endif
738 }
739 }
740
741 if (delay_time && (int)(monotonic_sec() - delay_time) >= 0) {
742 if (run_script(iface_status_str) != 0)
743 goto exiting;
744 delay_time = 0;
745 }
746 } /* while (1) */
747
748 cleanup:
749 if (!(opts & FLAG_NO_SHUTDOWN)
750 && (iface_status == IFSTATUS_UP
751 || (iface_status == IFSTATUS_DOWN && delay_time)
752 )
753 ) {
754 setenv(IFPLUGD_ENV_PREVIOUS, strstatus(iface_status), 1);
755 setenv(IFPLUGD_ENV_CURRENT, strstatus(-1), 1);
756 run_script("down\0up"); /* reusing string */
757 }
758
759 exiting:
760 remove_pidfile(pidfile_name);
761 bb_error_msg_and_die("exiting");
762}
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