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path: root/networking/ifplugd.c (plain)
blob: 4f8a274b0afde8ed45d6b54e13914c1c390e3dc1
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//config:config IFPLUGD
10//config: bool "ifplugd"
11//config: default y
12//config: select PLATFORM_LINUX
13//config: help
14//config: Network interface plug detection daemon.
15
16//applet:IF_IFPLUGD(APPLET(ifplugd, BB_DIR_USR_SBIN, BB_SUID_DROP))
17
18//kbuild:lib-$(CONFIG_IFPLUGD) += ifplugd.o
19
20//usage:#define ifplugd_trivial_usage
21//usage: "[OPTIONS]"
22//usage:#define ifplugd_full_usage "\n\n"
23//usage: "Network interface plug detection daemon\n"
24//usage: "\n -n Don't daemonize"
25//usage: "\n -s Don't log to syslog"
26//usage: "\n -i IFACE Interface"
27//usage: "\n -f/-F Treat link detection error as link down/link up"
28//usage: "\n (otherwise exit on error)"
29//usage: "\n -a Don't up interface at each link probe"
30//usage: "\n -M Monitor creation/destruction of interface"
31//usage: "\n (otherwise it must exist)"
32//usage: "\n -r PROG Script to run"
33//usage: "\n -x ARG Extra argument for script"
34//usage: "\n -I Don't exit on nonzero exit code from script"
35//usage: "\n -p Don't run \"up\" script on startup"
36//usage: "\n -q Don't run \"down\" script on exit"
37//usage: "\n -l Always run script on startup"
38//usage: "\n -t SECS Poll time in seconds"
39//usage: "\n -u SECS Delay before running script after link up"
40//usage: "\n -d SECS Delay after link down"
41//usage: "\n -m MODE API mode (mii, priv, ethtool, wlan, iff, auto)"
42//usage: "\n -k Kill running daemon"
43
44#include "libbb.h"
45
46#include "fix_u32.h"
47#include <linux/if.h>
48#include <linux/mii.h>
49#include <linux/ethtool.h>
50#ifdef HAVE_NET_ETHERNET_H
51/* musl breakage:
52 * In file included from /usr/include/net/ethernet.h:10,
53 * from networking/ifplugd.c:41:
54 * /usr/include/netinet/if_ether.h:96: error: redefinition of 'struct ethhdr'
55 *
56 * Build succeeds without it on musl. Commented it out.
57 * If on your system you need it, consider removing <linux/ethtool.h>
58 * and copy-pasting its definitions here (<linux/ethtool.h> is what pulls in
59 * conflicting definition of struct ethhdr on musl).
60 */
61/* # include <net/ethernet.h> */
62#endif
63#include <linux/netlink.h>
64#include <linux/rtnetlink.h>
65#include <linux/sockios.h>
66#include <syslog.h>
67
68#define __user
69#include <linux/wireless.h>
70
71#ifndef ETH_ALEN
72# define ETH_ALEN 6
73#endif
74
75/*
76From initial port to busybox, removed most of the redundancy by
77converting implementation of a polymorphic interface to the strict
78functional style. The main role is run a script when link state
79changed, other activities like audio signal or detailed reports
80are on the script itself.
81
82One questionable point of the design is netlink usage:
83
84We have 1 second timeout by default to poll the link status,
85it is short enough so that there are no real benefits in
86using netlink to get "instantaneous" interface creation/deletion
87notifications. We can check for interface existence by just
88doing some fast ioctl using its name.
89
90Netlink code then can be just dropped (1k or more?)
91*/
92
93
94#define IFPLUGD_ENV_PREVIOUS "IFPLUGD_PREVIOUS"
95#define IFPLUGD_ENV_CURRENT "IFPLUGD_CURRENT"
96
97enum {
98 FLAG_NO_AUTO = 1 << 0, // -a, Do not enable interface automatically
99 FLAG_NO_DAEMON = 1 << 1, // -n, Do not daemonize
100 FLAG_NO_SYSLOG = 1 << 2, // -s, Do not use syslog, use stderr instead
101 FLAG_IGNORE_FAIL = 1 << 3, // -f, Ignore detection failure, retry instead (failure is treated as DOWN)
102 FLAG_IGNORE_FAIL_POSITIVE = 1 << 4, // -F, Ignore detection failure, retry instead (failure is treated as UP)
103 FLAG_IFACE = 1 << 5, // -i, Specify ethernet interface
104 FLAG_RUN = 1 << 6, // -r, Specify program to execute
105 FLAG_IGNORE_RETVAL = 1 << 7, // -I, Don't exit on nonzero return value of program executed
106 FLAG_POLL_TIME = 1 << 8, // -t, Specify poll time in seconds
107 FLAG_DELAY_UP = 1 << 9, // -u, Specify delay for configuring interface
108 FLAG_DELAY_DOWN = 1 << 10, // -d, Specify delay for deconfiguring interface
109 FLAG_API_MODE = 1 << 11, // -m, Force API mode (mii, priv, ethtool, wlan, auto)
110 FLAG_NO_STARTUP = 1 << 12, // -p, Don't run script on daemon startup
111 FLAG_NO_SHUTDOWN = 1 << 13, // -q, Don't run script on daemon quit
112 FLAG_INITIAL_DOWN = 1 << 14, // -l, Run "down" script on startup if no cable is detected
113 FLAG_EXTRA_ARG = 1 << 15, // -x, Specify an extra argument for action script
114 FLAG_MONITOR = 1 << 16, // -M, Use interface monitoring
115#if ENABLE_FEATURE_PIDFILE
116 FLAG_KILL = 1 << 17, // -k, Kill a running daemon
117#endif
118};
119#if ENABLE_FEATURE_PIDFILE
120# define OPTION_STR "+ansfFi:r:It:+u:+d:+m:pqlx:Mk"
121#else
122# define OPTION_STR "+ansfFi:r:It:+u:+d:+m:pqlx:M"
123#endif
124
125enum { // interface status
126 IFSTATUS_ERR = -1,
127 IFSTATUS_DOWN = 0,
128 IFSTATUS_UP = 1,
129};
130
131enum { // constant fds
132 ioctl_fd = 3,
133 netlink_fd = 4,
134};
135
136struct globals {
137 smallint iface_last_status;
138 smallint iface_prev_status;
139 smallint iface_exists;
140 smallint api_method_num;
141
142 /* Used in getopt32, must have sizeof == sizeof(int) */
143 unsigned poll_time;
144 unsigned delay_up;
145 unsigned delay_down;
146
147 const char *iface;
148 const char *api_mode;
149 const char *script_name;
150 const char *extra_arg;
151};
152#define G (*ptr_to_globals)
153#define INIT_G() do { \
154 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
155 G.iface_last_status = -1; \
156 G.iface_exists = 1; \
157 G.poll_time = 1; \
158 G.delay_down = 5; \
159 G.iface = "eth0"; \
160 G.api_mode = "a"; \
161 G.script_name = "/etc/ifplugd/ifplugd.action"; \
162} while (0)
163
164
165/* Utility routines */
166
167static void set_ifreq_to_ifname(struct ifreq *ifreq)
168{
169 memset(ifreq, 0, sizeof(struct ifreq));
170 strncpy_IFNAMSIZ(ifreq->ifr_name, G.iface);
171}
172
173static int network_ioctl(int request, void* data, const char *errmsg)
174{
175 int r = ioctl(ioctl_fd, request, data);
176 if (r < 0 && errmsg)
177 bb_perror_msg("%s failed", errmsg);
178 return r;
179}
180
181/* Link detection routines and table */
182
183static smallint detect_link_mii(void)
184{
185 /* char buffer instead of bona-fide struct avoids aliasing warning */
186 char buf[sizeof(struct ifreq)];
187 struct ifreq *const ifreq = (void *)buf;
188
189 struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
190
191 set_ifreq_to_ifname(ifreq);
192
193 if (network_ioctl(SIOCGMIIPHY, ifreq, "SIOCGMIIPHY") < 0) {
194 return IFSTATUS_ERR;
195 }
196
197 mii->reg_num = 1;
198
199 if (network_ioctl(SIOCGMIIREG, ifreq, "SIOCGMIIREG") < 0) {
200 return IFSTATUS_ERR;
201 }
202
203 return (mii->val_out & 0x0004) ? IFSTATUS_UP : IFSTATUS_DOWN;
204}
205
206static smallint detect_link_priv(void)
207{
208 /* char buffer instead of bona-fide struct avoids aliasing warning */
209 char buf[sizeof(struct ifreq)];
210 struct ifreq *const ifreq = (void *)buf;
211
212 struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
213
214 set_ifreq_to_ifname(ifreq);
215
216 if (network_ioctl(SIOCDEVPRIVATE, ifreq, "SIOCDEVPRIVATE") < 0) {
217 return IFSTATUS_ERR;
218 }
219
220 mii->reg_num = 1;
221
222 if (network_ioctl(SIOCDEVPRIVATE+1, ifreq, "SIOCDEVPRIVATE+1") < 0) {
223 return IFSTATUS_ERR;
224 }
225
226 return (mii->val_out & 0x0004) ? IFSTATUS_UP : IFSTATUS_DOWN;
227}
228
229static smallint detect_link_ethtool(void)
230{
231 struct ifreq ifreq;
232 struct ethtool_value edata;
233
234 set_ifreq_to_ifname(&ifreq);
235
236 edata.cmd = ETHTOOL_GLINK;
237 ifreq.ifr_data = (void*) &edata;
238
239 if (network_ioctl(SIOCETHTOOL, &ifreq, "ETHTOOL_GLINK") < 0) {
240 return IFSTATUS_ERR;
241 }
242
243 return edata.data ? IFSTATUS_UP : IFSTATUS_DOWN;
244}
245
246static smallint detect_link_iff(void)
247{
248 struct ifreq ifreq;
249
250 set_ifreq_to_ifname(&ifreq);
251
252 if (network_ioctl(SIOCGIFFLAGS, &ifreq, "SIOCGIFFLAGS") < 0) {
253 return IFSTATUS_ERR;
254 }
255
256 /* If IFF_UP is not set (interface is down), IFF_RUNNING is never set
257 * regardless of link status. Simply continue to report last status -
258 * no point in reporting spurious link downs if interface is disabled
259 * by admin. When/if it will be brought up,
260 * we'll report real link status.
261 */
262 if (!(ifreq.ifr_flags & IFF_UP) && G.iface_last_status != IFSTATUS_ERR)
263 return G.iface_last_status;
264
265 return (ifreq.ifr_flags & IFF_RUNNING) ? IFSTATUS_UP : IFSTATUS_DOWN;
266}
267
268static smallint detect_link_wlan(void)
269{
270 int i;
271 struct iwreq iwrequest;
272 uint8_t mac[ETH_ALEN];
273
274 memset(&iwrequest, 0, sizeof(iwrequest));
275 strncpy_IFNAMSIZ(iwrequest.ifr_ifrn.ifrn_name, G.iface);
276
277 if (network_ioctl(SIOCGIWAP, &iwrequest, "SIOCGIWAP") < 0) {
278 return IFSTATUS_ERR;
279 }
280
281 memcpy(mac, &iwrequest.u.ap_addr.sa_data, ETH_ALEN);
282
283 if (mac[0] == 0xFF || mac[0] == 0x44 || mac[0] == 0x00) {
284 for (i = 1; i < ETH_ALEN; ++i) {
285 if (mac[i] != mac[0])
286 return IFSTATUS_UP;
287 }
288 return IFSTATUS_DOWN;
289 }
290
291 return IFSTATUS_UP;
292}
293
294enum { // api mode
295 API_ETHTOOL, // 'e'
296 API_MII, // 'm'
297 API_PRIVATE, // 'p'
298 API_WLAN, // 'w'
299 API_IFF, // 'i'
300 API_AUTO, // 'a'
301};
302
303static const char api_modes[] ALIGN1 = "empwia";
304
305static const struct {
306 const char *name;
307 smallint (*func)(void);
308} method_table[] = {
309 { "SIOCETHTOOL" , &detect_link_ethtool },
310 { "SIOCGMIIPHY" , &detect_link_mii },
311 { "SIOCDEVPRIVATE" , &detect_link_priv },
312 { "wireless extension", &detect_link_wlan },
313 { "IFF_RUNNING" , &detect_link_iff },
314};
315
316static const char *strstatus(int status)
317{
318 if (status == IFSTATUS_ERR)
319 return "error";
320 return "down\0up" + (status * 5);
321}
322
323static int run_script(const char *action)
324{
325 char *env_PREVIOUS, *env_CURRENT;
326 char *argv[5];
327 int r;
328
329 bb_error_msg("executing '%s %s %s'", G.script_name, G.iface, action);
330
331 argv[0] = (char*) G.script_name;
332 argv[1] = (char*) G.iface;
333 argv[2] = (char*) action;
334 argv[3] = (char*) G.extra_arg;
335 argv[4] = NULL;
336
337 env_PREVIOUS = xasprintf("%s=%s", IFPLUGD_ENV_PREVIOUS, strstatus(G.iface_prev_status));
338 putenv(env_PREVIOUS);
339 env_CURRENT = xasprintf("%s=%s", IFPLUGD_ENV_CURRENT, strstatus(G.iface_last_status));
340 putenv(env_CURRENT);
341
342 /* r < 0 - can't exec, 0 <= r < 0x180 - exited, >=0x180 - killed by sig (r-0x180) */
343 r = spawn_and_wait(argv);
344
345 unsetenv(IFPLUGD_ENV_PREVIOUS);
346 unsetenv(IFPLUGD_ENV_CURRENT);
347 free(env_PREVIOUS);
348 free(env_CURRENT);
349
350 bb_error_msg("exit code: %d", r & 0xff);
351 return (option_mask32 & FLAG_IGNORE_RETVAL) ? 0 : r;
352}
353
354static void up_iface(void)
355{
356 struct ifreq ifrequest;
357
358 if (!G.iface_exists)
359 return;
360
361 set_ifreq_to_ifname(&ifrequest);
362 if (network_ioctl(SIOCGIFFLAGS, &ifrequest, "getting interface flags") < 0) {
363 G.iface_exists = 0;
364 return;
365 }
366
367 if (!(ifrequest.ifr_flags & IFF_UP)) {
368 ifrequest.ifr_flags |= IFF_UP;
369 /* Let user know we mess up with interface */
370 bb_error_msg("upping interface");
371 if (network_ioctl(SIOCSIFFLAGS, &ifrequest, "setting interface flags") < 0) {
372 if (errno != ENODEV)
373 xfunc_die();
374 G.iface_exists = 0;
375 return;
376 }
377 }
378
379#if 0 /* why do we mess with IP addr? It's not our business */
380 if (network_ioctl(SIOCGIFADDR, &ifrequest, "can't get interface address") < 0) {
381 } else if (ifrequest.ifr_addr.sa_family != AF_INET) {
382 bb_perror_msg("the interface is not IP-based");
383 } else {
384 ((struct sockaddr_in*)(&ifrequest.ifr_addr))->sin_addr.s_addr = INADDR_ANY;
385 network_ioctl(SIOCSIFADDR, &ifrequest, "can't set interface address");
386 }
387 network_ioctl(SIOCGIFFLAGS, &ifrequest, "can't get interface flags");
388#endif
389}
390
391static void maybe_up_new_iface(void)
392{
393 if (!(option_mask32 & FLAG_NO_AUTO))
394 up_iface();
395
396#if 0 /* bloat */
397 struct ifreq ifrequest;
398 struct ethtool_drvinfo driver_info;
399
400 set_ifreq_to_ifname(&ifrequest);
401 driver_info.cmd = ETHTOOL_GDRVINFO;
402 ifrequest.ifr_data = &driver_info;
403 if (network_ioctl(SIOCETHTOOL, &ifrequest, NULL) == 0) {
404 char buf[sizeof("/xx:xx:xx:xx:xx:xx")];
405
406 /* Get MAC */
407 buf[0] = '\0';
408 set_ifreq_to_ifname(&ifrequest);
409 if (network_ioctl(SIOCGIFHWADDR, &ifrequest, NULL) == 0) {
410 sprintf(buf, "/%02X:%02X:%02X:%02X:%02X:%02X",
411 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[0]),
412 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[1]),
413 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[2]),
414 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[3]),
415 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[4]),
416 (uint8_t)(ifrequest.ifr_hwaddr.sa_data[5]));
417 }
418
419 bb_error_msg("using interface %s%s with driver<%s> (version: %s)",
420 G.iface, buf, driver_info.driver, driver_info.version);
421 }
422#endif
423 if (G.api_mode[0] == 'a')
424 G.api_method_num = API_AUTO;
425}
426
427static smallint detect_link(void)
428{
429 smallint status;
430
431 if (!G.iface_exists)
432 return (option_mask32 & FLAG_MONITOR) ? IFSTATUS_DOWN : IFSTATUS_ERR;
433
434 /* Some drivers can't detect link status when the interface is down.
435 * I imagine detect_link_iff() is the most vulnerable.
436 * That's why -a "noauto" in an option, not a hardwired behavior.
437 */
438 if (!(option_mask32 & FLAG_NO_AUTO))
439 up_iface();
440
441 if (G.api_method_num == API_AUTO) {
442 int i;
443 smallint sv_logmode;
444
445 sv_logmode = logmode;
446 for (i = 0; i < ARRAY_SIZE(method_table); i++) {
447 logmode = LOGMODE_NONE;
448 status = method_table[i].func();
449 logmode = sv_logmode;
450 if (status != IFSTATUS_ERR) {
451 G.api_method_num = i;
452 bb_error_msg("using %s detection mode", method_table[i].name);
453 break;
454 }
455 }
456 } else {
457 status = method_table[G.api_method_num].func();
458 }
459
460 if (status == IFSTATUS_ERR) {
461 if (option_mask32 & FLAG_IGNORE_FAIL)
462 status = IFSTATUS_DOWN;
463 else if (option_mask32 & FLAG_IGNORE_FAIL_POSITIVE)
464 status = IFSTATUS_UP;
465 else if (G.api_mode[0] == 'a')
466 bb_error_msg("can't detect link status");
467 }
468
469 if (status != G.iface_last_status) {
470 G.iface_prev_status = G.iface_last_status;
471 G.iface_last_status = status;
472 }
473
474 return status;
475}
476
477static NOINLINE int check_existence_through_netlink(void)
478{
479 int iface_len;
480 /* Buffer was 1K, but on linux-3.9.9 it was reported to be too small.
481 * netlink.h: "limit to 8K to avoid MSG_TRUNC when PAGE_SIZE is very large".
482 * Note: on error returns (-1) we exit, no need to free replybuf.
483 */
484 enum { BUF_SIZE = 8 * 1024 };
485 char *replybuf = xmalloc(BUF_SIZE);
486
487 iface_len = strlen(G.iface);
488 while (1) {
489 struct nlmsghdr *mhdr;
490 ssize_t bytes;
491
492 bytes = recv(netlink_fd, replybuf, BUF_SIZE, MSG_DONTWAIT);
493 if (bytes < 0) {
494 if (errno == EAGAIN)
495 goto ret;
496 if (errno == EINTR)
497 continue;
498 bb_perror_msg("netlink: recv");
499 return -1;
500 }
501
502 mhdr = (struct nlmsghdr*)replybuf;
503 while (bytes > 0) {
504 if (!NLMSG_OK(mhdr, bytes)) {
505 bb_error_msg("netlink packet too small or truncated");
506 return -1;
507 }
508
509 if (mhdr->nlmsg_type == RTM_NEWLINK || mhdr->nlmsg_type == RTM_DELLINK) {
510 struct rtattr *attr;
511 int attr_len;
512
513 if (mhdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifinfomsg))) {
514 bb_error_msg("netlink packet too small or truncated");
515 return -1;
516 }
517
518 attr = IFLA_RTA(NLMSG_DATA(mhdr));
519 attr_len = IFLA_PAYLOAD(mhdr);
520
521 while (RTA_OK(attr, attr_len)) {
522 if (attr->rta_type == IFLA_IFNAME) {
523 int len = RTA_PAYLOAD(attr);
524 if (len > IFNAMSIZ)
525 len = IFNAMSIZ;
526 if (iface_len <= len
527 && strncmp(G.iface, RTA_DATA(attr), len) == 0
528 ) {
529 G.iface_exists = (mhdr->nlmsg_type == RTM_NEWLINK);
530 }
531 }
532 attr = RTA_NEXT(attr, attr_len);
533 }
534 }
535
536 mhdr = NLMSG_NEXT(mhdr, bytes);
537 }
538 }
539
540 ret:
541 free(replybuf);
542 return G.iface_exists;
543}
544
545#if ENABLE_FEATURE_PIDFILE
546static NOINLINE pid_t read_pid(const char *filename)
547{
548 int len;
549 char buf[128];
550
551 len = open_read_close(filename, buf, 127);
552 if (len > 0) {
553 buf[len] = '\0';
554 /* returns ULONG_MAX on error => -1 */
555 return bb_strtoul(buf, NULL, 10);
556 }
557 return 0;
558}
559#endif
560
561int ifplugd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
562int ifplugd_main(int argc UNUSED_PARAM, char **argv)
563{
564 int iface_status;
565 int delay_time;
566 const char *iface_status_str;
567 struct pollfd netlink_pollfd[1];
568 unsigned opts;
569 const char *api_mode_found;
570#if ENABLE_FEATURE_PIDFILE
571 char *pidfile_name;
572 pid_t pid_from_pidfile;
573#endif
574
575 INIT_G();
576
577 opts = getopt32(argv, OPTION_STR,
578 &G.iface, &G.script_name, &G.poll_time, &G.delay_up,
579 &G.delay_down, &G.api_mode, &G.extra_arg);
580 G.poll_time *= 1000;
581
582 applet_name = xasprintf("ifplugd(%s)", G.iface);
583
584#if ENABLE_FEATURE_PIDFILE
585 pidfile_name = xasprintf(CONFIG_PID_FILE_PATH "/ifplugd.%s.pid", G.iface);
586 pid_from_pidfile = read_pid(pidfile_name);
587
588 if (opts & FLAG_KILL) {
589 if (pid_from_pidfile > 0)
590 /* Upstream tool use SIGINT for -k */
591 kill(pid_from_pidfile, SIGINT);
592 return EXIT_SUCCESS;
593 }
594
595 if (pid_from_pidfile > 0 && kill(pid_from_pidfile, 0) == 0)
596 bb_error_msg_and_die("daemon already running");
597#endif
598
599 api_mode_found = strchr(api_modes, G.api_mode[0]);
600 if (!api_mode_found)
601 bb_error_msg_and_die("unknown API mode '%s'", G.api_mode);
602 G.api_method_num = api_mode_found - api_modes;
603
604 if (!(opts & FLAG_NO_DAEMON))
605 bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
606
607 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), ioctl_fd);
608 if (opts & FLAG_MONITOR) {
609 struct sockaddr_nl addr;
610 int fd = xsocket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
611
612 memset(&addr, 0, sizeof(addr));
613 addr.nl_family = AF_NETLINK;
614 addr.nl_groups = RTMGRP_LINK;
615 addr.nl_pid = getpid();
616
617 xbind(fd, (struct sockaddr*)&addr, sizeof(addr));
618 xmove_fd(fd, netlink_fd);
619 }
620
621 write_pidfile(pidfile_name);
622
623 /* this can't be moved before socket creation */
624 if (!(opts & FLAG_NO_SYSLOG)) {
625 openlog(applet_name, 0, LOG_DAEMON);
626 logmode |= LOGMODE_SYSLOG;
627 }
628
629 bb_signals(0
630 | (1 << SIGINT )
631 | (1 << SIGTERM)
632 | (1 << SIGQUIT)
633 | (1 << SIGHUP ) /* why we ignore it? */
634 /* | (1 << SIGCHLD) - run_script does not use it anymore */
635 , record_signo);
636
637 bb_error_msg("started: %s", bb_banner);
638
639 if (opts & FLAG_MONITOR) {
640 struct ifreq ifrequest;
641 set_ifreq_to_ifname(&ifrequest);
642 G.iface_exists = (network_ioctl(SIOCGIFINDEX, &ifrequest, NULL) == 0);
643 }
644
645 if (G.iface_exists)
646 maybe_up_new_iface();
647
648 iface_status = detect_link();
649 if (iface_status == IFSTATUS_ERR)
650 goto exiting;
651 iface_status_str = strstatus(iface_status);
652
653 if (opts & FLAG_MONITOR) {
654 bb_error_msg("interface %s",
655 G.iface_exists ? "exists"
656 : "doesn't exist, waiting");
657 }
658 /* else we assume it always exists, but don't mislead user
659 * by potentially lying that it really exists */
660
661 if (G.iface_exists) {
662 bb_error_msg("link is %s", iface_status_str);
663 }
664
665 if ((!(opts & FLAG_NO_STARTUP)
666 && iface_status == IFSTATUS_UP
667 )
668 || (opts & FLAG_INITIAL_DOWN)
669 ) {
670 if (run_script(iface_status_str) != 0)
671 goto exiting;
672 }
673
674 /* Main loop */
675 netlink_pollfd[0].fd = netlink_fd;
676 netlink_pollfd[0].events = POLLIN;
677 delay_time = 0;
678 while (1) {
679 int iface_status_old;
680
681 switch (bb_got_signal) {
682 case SIGINT:
683 case SIGTERM:
684 bb_got_signal = 0;
685 goto cleanup;
686 case SIGQUIT:
687 bb_got_signal = 0;
688 goto exiting;
689 default:
690 bb_got_signal = 0;
691 break;
692 }
693
694 if (poll(netlink_pollfd,
695 (opts & FLAG_MONITOR) ? 1 : 0,
696 G.poll_time
697 ) < 0
698 ) {
699 if (errno == EINTR)
700 continue;
701 bb_perror_msg("poll");
702 goto exiting;
703 }
704
705 if ((opts & FLAG_MONITOR)
706 && (netlink_pollfd[0].revents & POLLIN)
707 ) {
708 int iface_exists_old;
709
710 iface_exists_old = G.iface_exists;
711 G.iface_exists = check_existence_through_netlink();
712 if (G.iface_exists < 0) /* error */
713 goto exiting;
714 if (iface_exists_old != G.iface_exists) {
715 bb_error_msg("interface %sappeared",
716 G.iface_exists ? "" : "dis");
717 if (G.iface_exists)
718 maybe_up_new_iface();
719 }
720 }
721
722 /* note: if !G.iface_exists, returns DOWN */
723 iface_status_old = iface_status;
724 iface_status = detect_link();
725 if (iface_status == IFSTATUS_ERR) {
726 if (!(opts & FLAG_MONITOR))
727 goto exiting;
728 iface_status = IFSTATUS_DOWN;
729 }
730 iface_status_str = strstatus(iface_status);
731
732 if (iface_status_old != iface_status) {
733 bb_error_msg("link is %s", iface_status_str);
734
735 if (delay_time) {
736 /* link restored its old status before
737 * we ran script. don't run the script: */
738 delay_time = 0;
739 } else {
740 delay_time = monotonic_sec();
741 if (iface_status == IFSTATUS_UP)
742 delay_time += G.delay_up;
743 if (iface_status == IFSTATUS_DOWN)
744 delay_time += G.delay_down;
745#if 0 /* if you are back in 1970... */
746 if (delay_time == 0) {
747 sleep(1);
748 delay_time = 1;
749 }
750#endif
751 }
752 }
753
754 if (delay_time && (int)(monotonic_sec() - delay_time) >= 0) {
755 if (run_script(iface_status_str) != 0)
756 goto exiting;
757 delay_time = 0;
758 }
759 } /* while (1) */
760
761 cleanup:
762 if (!(opts & FLAG_NO_SHUTDOWN)
763 && (iface_status == IFSTATUS_UP
764 || (iface_status == IFSTATUS_DOWN && delay_time)
765 )
766 ) {
767 setenv(IFPLUGD_ENV_PREVIOUS, strstatus(iface_status), 1);
768 setenv(IFPLUGD_ENV_CURRENT, strstatus(-1), 1);
769 run_script("down\0up"); /* reusing string */
770 }
771
772 exiting:
773 remove_pidfile(pidfile_name);
774 bb_error_msg_and_die("exiting");
775}
776
generated by cgit at 2024-05-15 12:01:14 (GMT)