blob: 18dcaff96ee6a2e144ec65e3a44de7eba702a0a3 [file] [log] [blame]
Denis Vlasenko71c16572009-04-26 01:08:51 +00001/* vi: set sw=4 ts=4: */
2/*
Maxim Kryzhanovsky2004fa12010-03-30 15:49:57 +02003 * ifplugd for busybox, based on ifplugd 0.28 (written by Lennart Poettering).
Denis Vlasenko71c16572009-04-26 01:08:51 +00004 *
Denis Vlasenkof4e45632009-04-26 01:17:44 +00005 * Copyright (C) 2009 Maksym Kryzhanovskyy <xmaks@email.cz>
Denis Vlasenko71c16572009-04-26 01:08:51 +00006 *
Denys Vlasenko0ef64bd2010-08-16 20:14:46 +02007 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
Denis Vlasenko71c16572009-04-26 01:08:51 +00008 */
Denys Vlasenko47367e12016-11-23 09:05:14 +01009//config:config IFPLUGD
Denys Vlasenkob097a842018-12-28 03:20:17 +010010//config: bool "ifplugd (10 kb)"
Denys Vlasenko47367e12016-11-23 09:05:14 +010011//config: default y
Denys Vlasenko47367e12016-11-23 09:05:14 +010012//config: help
Denys Vlasenko72089cf2017-07-21 09:50:55 +020013//config: Network interface plug detection daemon.
Denys Vlasenko47367e12016-11-23 09:05:14 +010014
15//applet:IF_IFPLUGD(APPLET(ifplugd, BB_DIR_USR_SBIN, BB_SUID_DROP))
16
17//kbuild:lib-$(CONFIG_IFPLUGD) += ifplugd.o
Pere Orga5bc8c002011-04-11 03:29:49 +020018
19//usage:#define ifplugd_trivial_usage
20//usage: "[OPTIONS]"
21//usage:#define ifplugd_full_usage "\n\n"
22//usage: "Network interface plug detection daemon\n"
Pere Orga5bc8c002011-04-11 03:29:49 +020023//usage: "\n -n Don't daemonize"
24//usage: "\n -s Don't log to syslog"
25//usage: "\n -i IFACE Interface"
26//usage: "\n -f/-F Treat link detection error as link down/link up"
27//usage: "\n (otherwise exit on error)"
28//usage: "\n -a Don't up interface at each link probe"
29//usage: "\n -M Monitor creation/destruction of interface"
30//usage: "\n (otherwise it must exist)"
31//usage: "\n -r PROG Script to run"
32//usage: "\n -x ARG Extra argument for script"
33//usage: "\n -I Don't exit on nonzero exit code from script"
Denys Vlasenko21f620f2012-06-03 10:26:16 +020034//usage: "\n -p Don't run \"up\" script on startup"
35//usage: "\n -q Don't run \"down\" script on exit"
36//usage: "\n -l Always run script on startup"
Pere Orga5bc8c002011-04-11 03:29:49 +020037//usage: "\n -t SECS Poll time in seconds"
38//usage: "\n -u SECS Delay before running script after link up"
39//usage: "\n -d SECS Delay after link down"
40//usage: "\n -m MODE API mode (mii, priv, ethtool, wlan, iff, auto)"
41//usage: "\n -k Kill running daemon"
42
Denis Vlasenko71c16572009-04-26 01:08:51 +000043#include "libbb.h"
44
Denys Vlasenko0568b6e2009-08-08 03:20:12 +020045#include "fix_u32.h"
Denis Vlasenko71c16572009-04-26 01:08:51 +000046#include <linux/if.h>
Denys Vlasenko9c35a1c2009-05-01 09:04:25 +020047#include <linux/mii.h>
Denis Vlasenko71c16572009-04-26 01:08:51 +000048#include <linux/ethtool.h>
Dan Fandrichf533ec82011-06-10 05:17:59 +020049#ifdef HAVE_NET_ETHERNET_H
Denys Vlasenko5fa6d1a2015-10-05 11:15:43 +020050/* musl breakage:
51 * In file included from /usr/include/net/ethernet.h:10,
52 * from networking/ifplugd.c:41:
53 * /usr/include/netinet/if_ether.h:96: error: redefinition of 'struct ethhdr'
54 *
55 * Build succeeds without it on musl. Commented it out.
56 * If on your system you need it, consider removing <linux/ethtool.h>
57 * and copy-pasting its definitions here (<linux/ethtool.h> is what pulls in
58 * conflicting definition of struct ethhdr on musl).
59 */
60/* # include <net/ethernet.h> */
Dan Fandrichf533ec82011-06-10 05:17:59 +020061#endif
Denis Vlasenko71c16572009-04-26 01:08:51 +000062#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
Denys Vlasenko42716982015-10-07 02:02:56 +020070#ifndef ETH_ALEN
71# define ETH_ALEN 6
72#endif
73
Denis Vlasenkof4e45632009-04-26 01:17:44 +000074/*
Maxim Kryzhanovsky2004fa12010-03-30 15:49:57 +020075From initial port to busybox, removed most of the redundancy by
76converting implementation of a polymorphic interface to the strict
77functional style. The main role is run a script when link state
78changed, other activities like audio signal or detailed reports
79are on the script itself.
Denis Vlasenkof4e45632009-04-26 01:17:44 +000080
81One questionable point of the design is netlink usage:
82
83We have 1 second timeout by default to poll the link status,
84it is short enough so that there are no real benefits in
85using netlink to get "instantaneous" interface creation/deletion
86notifications. We can check for interface existence by just
87doing some fast ioctl using its name.
88
89Netlink code then can be just dropped (1k or more?)
90*/
91
92
Denis Vlasenko71c16572009-04-26 01:08:51 +000093#define IFPLUGD_ENV_PREVIOUS "IFPLUGD_PREVIOUS"
94#define IFPLUGD_ENV_CURRENT "IFPLUGD_CURRENT"
95
96enum {
97 FLAG_NO_AUTO = 1 << 0, // -a, Do not enable interface automatically
98 FLAG_NO_DAEMON = 1 << 1, // -n, Do not daemonize
99 FLAG_NO_SYSLOG = 1 << 2, // -s, Do not use syslog, use stderr instead
100 FLAG_IGNORE_FAIL = 1 << 3, // -f, Ignore detection failure, retry instead (failure is treated as DOWN)
101 FLAG_IGNORE_FAIL_POSITIVE = 1 << 4, // -F, Ignore detection failure, retry instead (failure is treated as UP)
102 FLAG_IFACE = 1 << 5, // -i, Specify ethernet interface
103 FLAG_RUN = 1 << 6, // -r, Specify program to execute
104 FLAG_IGNORE_RETVAL = 1 << 7, // -I, Don't exit on nonzero return value of program executed
105 FLAG_POLL_TIME = 1 << 8, // -t, Specify poll time in seconds
106 FLAG_DELAY_UP = 1 << 9, // -u, Specify delay for configuring interface
107 FLAG_DELAY_DOWN = 1 << 10, // -d, Specify delay for deconfiguring interface
108 FLAG_API_MODE = 1 << 11, // -m, Force API mode (mii, priv, ethtool, wlan, auto)
109 FLAG_NO_STARTUP = 1 << 12, // -p, Don't run script on daemon startup
110 FLAG_NO_SHUTDOWN = 1 << 13, // -q, Don't run script on daemon quit
111 FLAG_INITIAL_DOWN = 1 << 14, // -l, Run "down" script on startup if no cable is detected
112 FLAG_EXTRA_ARG = 1 << 15, // -x, Specify an extra argument for action script
113 FLAG_MONITOR = 1 << 16, // -M, Use interface monitoring
114#if ENABLE_FEATURE_PIDFILE
115 FLAG_KILL = 1 << 17, // -k, Kill a running daemon
116#endif
117};
118#if ENABLE_FEATURE_PIDFILE
Denys Vlasenko237bedd2016-07-06 21:58:02 +0200119# define OPTION_STR "+ansfFi:r:It:+u:+d:+m:pqlx:Mk"
Denis Vlasenko71c16572009-04-26 01:08:51 +0000120#else
Denys Vlasenko237bedd2016-07-06 21:58:02 +0200121# define OPTION_STR "+ansfFi:r:It:+u:+d:+m:pqlx:M"
Denis Vlasenko71c16572009-04-26 01:08:51 +0000122#endif
123
Denis Vlasenko71c16572009-04-26 01:08:51 +0000124enum { // interface status
125 IFSTATUS_ERR = -1,
126 IFSTATUS_DOWN = 0,
127 IFSTATUS_UP = 1,
128};
129
130enum { // constant fds
131 ioctl_fd = 3,
132 netlink_fd = 4,
133};
134
135struct globals {
136 smallint iface_last_status;
Denys Vlasenko19afe842010-05-08 23:26:16 +0200137 smallint iface_prev_status;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000138 smallint iface_exists;
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200139 smallint api_method_num;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000140
141 /* Used in getopt32, must have sizeof == sizeof(int) */
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;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000150};
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
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200164/* Utility routines */
165
166static void set_ifreq_to_ifname(struct ifreq *ifreq)
Denys Vlasenko19afe842010-05-08 23:26:16 +0200167{
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200168 memset(ifreq, 0, sizeof(struct ifreq));
169 strncpy_IFNAMSIZ(ifreq->ifr_name, G.iface);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000170}
171
Denys Vlasenkof422a722010-01-08 12:27:57 +0100172static int network_ioctl(int request, void* data, const char *errmsg)
Denis Vlasenko71c16572009-04-26 01:08:51 +0000173{
Denys Vlasenkof422a722010-01-08 12:27:57 +0100174 int r = ioctl(ioctl_fd, request, data);
175 if (r < 0 && errmsg)
Maxim Kryzhanovskyfcb84c82010-03-29 09:09:05 +0200176 bb_perror_msg("%s failed", errmsg);
Denys Vlasenkof422a722010-01-08 12:27:57 +0100177 return r;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000178}
179
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200180/* Link detection routines and table */
Denis Vlasenko71c16572009-04-26 01:08:51 +0000181
182static smallint detect_link_mii(void)
183{
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100184 /* char buffer instead of bona-fide struct avoids aliasing warning */
185 char buf[sizeof(struct ifreq)];
Denys Vlasenkob3b6c8b2011-01-20 11:29:00 +0100186 struct ifreq *const ifreq = (void *)buf;
187
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100188 struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000189
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100190 set_ifreq_to_ifname(ifreq);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000191
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100192 if (network_ioctl(SIOCGMIIPHY, ifreq, "SIOCGMIIPHY") < 0) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000193 return IFSTATUS_ERR;
194 }
195
Denys Vlasenko9c35a1c2009-05-01 09:04:25 +0200196 mii->reg_num = 1;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000197
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100198 if (network_ioctl(SIOCGMIIREG, ifreq, "SIOCGMIIREG") < 0) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000199 return IFSTATUS_ERR;
200 }
201
Denys Vlasenko9c35a1c2009-05-01 09:04:25 +0200202 return (mii->val_out & 0x0004) ? IFSTATUS_UP : IFSTATUS_DOWN;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000203}
204
205static smallint detect_link_priv(void)
206{
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100207 /* char buffer instead of bona-fide struct avoids aliasing warning */
208 char buf[sizeof(struct ifreq)];
Denys Vlasenkob3b6c8b2011-01-20 11:29:00 +0100209 struct ifreq *const ifreq = (void *)buf;
210
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100211 struct mii_ioctl_data *mii = (void *)&ifreq->ifr_data;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000212
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100213 set_ifreq_to_ifname(ifreq);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000214
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100215 if (network_ioctl(SIOCDEVPRIVATE, ifreq, "SIOCDEVPRIVATE") < 0) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000216 return IFSTATUS_ERR;
217 }
218
Denys Vlasenko9c35a1c2009-05-01 09:04:25 +0200219 mii->reg_num = 1;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000220
Denys Vlasenko53f30b42011-01-20 01:20:36 +0100221 if (network_ioctl(SIOCDEVPRIVATE+1, ifreq, "SIOCDEVPRIVATE+1") < 0) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000222 return IFSTATUS_ERR;
223 }
224
Denys Vlasenko9c35a1c2009-05-01 09:04:25 +0200225 return (mii->val_out & 0x0004) ? IFSTATUS_UP : IFSTATUS_DOWN;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000226}
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;
Denys Vlasenko337a31b2009-10-23 18:31:02 +0200236 ifreq.ifr_data = (void*) &edata;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000237
Maxim Kryzhanovskyfcb84c82010-03-29 09:09:05 +0200238 if (network_ioctl(SIOCETHTOOL, &ifreq, "ETHTOOL_GLINK") < 0) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000239 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
Maxim Kryzhanovskyfcb84c82010-03-29 09:09:05 +0200251 if (network_ioctl(SIOCGIFFLAGS, &ifreq, "SIOCGIFFLAGS") < 0) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000252 return IFSTATUS_ERR;
253 }
254
Denys Vlasenkof422a722010-01-08 12:27:57 +0100255 /* If IFF_UP is not set (interface is down), IFF_RUNNING is never set
256 * regardless of link status. Simply continue to report last status -
257 * no point in reporting spurious link downs if interface is disabled
258 * by admin. When/if it will be brought up,
259 * we'll report real link status.
260 */
261 if (!(ifreq.ifr_flags & IFF_UP) && G.iface_last_status != IFSTATUS_ERR)
262 return G.iface_last_status;
263
Denis Vlasenko71c16572009-04-26 01:08:51 +0000264 return (ifreq.ifr_flags & IFF_RUNNING) ? IFSTATUS_UP : IFSTATUS_DOWN;
265}
266
267static smallint detect_link_wlan(void)
268{
Maxim Kryzhanovskyfcb84c82010-03-29 09:09:05 +0200269 int i;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000270 struct iwreq iwrequest;
271 uint8_t mac[ETH_ALEN];
272
Maxim Kryzhanovskyfcb84c82010-03-29 09:09:05 +0200273 memset(&iwrequest, 0, sizeof(iwrequest));
Denis Vlasenko80e57eb2009-04-26 01:43:36 +0000274 strncpy_IFNAMSIZ(iwrequest.ifr_ifrn.ifrn_name, G.iface);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000275
Maxim Kryzhanovskyfcb84c82010-03-29 09:09:05 +0200276 if (network_ioctl(SIOCGIWAP, &iwrequest, "SIOCGIWAP") < 0) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000277 return IFSTATUS_ERR;
278 }
279
Maxim Kryzhanovskyfcb84c82010-03-29 09:09:05 +0200280 memcpy(mac, &iwrequest.u.ap_addr.sa_data, ETH_ALEN);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000281
282 if (mac[0] == 0xFF || mac[0] == 0x44 || mac[0] == 0x00) {
Maxim Kryzhanovskyfcb84c82010-03-29 09:09:05 +0200283 for (i = 1; i < ETH_ALEN; ++i) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000284 if (mac[i] != mac[0])
285 return IFSTATUS_UP;
286 }
287 return IFSTATUS_DOWN;
288 }
289
290 return IFSTATUS_UP;
291}
292
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200293enum { // api mode
294 API_ETHTOOL, // 'e'
295 API_MII, // 'm'
296 API_PRIVATE, // 'p'
297 API_WLAN, // 'w'
298 API_IFF, // 'i'
299 API_AUTO, // 'a'
300};
301
302static const char api_modes[] ALIGN1 = "empwia";
303
304static const struct {
305 const char *name;
306 smallint (*func)(void);
Denys Vlasenko965b7952020-11-30 13:03:03 +0100307} method_table[] ALIGN_PTR = {
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200308 { "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
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200315static 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
James Byrne253c4e72019-04-12 17:01:51 +0000328 bb_info_msg("executing '%s %s %s'", G.script_name, G.iface, action);
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200329
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 /* r < 0 - can't exec, 0 <= r < 0x180 - exited, >=0x180 - killed by sig (r-0x180) */
342 r = spawn_and_wait(argv);
343
Denys Vlasenkoe4f6bfd2017-07-22 03:04:20 +0200344 bb_unsetenv_and_free(env_PREVIOUS);
345 bb_unsetenv_and_free(env_CURRENT);
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200346
James Byrne253c4e72019-04-12 17:01:51 +0000347 bb_info_msg("exit code: %d", r & 0xff);
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200348 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 /* Let user know we mess up with interface */
James Byrne69374872019-07-02 11:35:03 +0200367 bb_simple_info_msg("upping interface");
Denys Vlasenkob11be132016-08-16 20:39:52 +0200368 if (network_ioctl(SIOCSIFFLAGS, &ifrequest, "setting interface flags") < 0) {
Stefan Agner2adaa902018-03-29 14:12:31 +0200369 if (errno != ENODEV && errno != EADDRNOTAVAIL)
Denys Vlasenkob11be132016-08-16 20:39:52 +0200370 xfunc_die();
371 G.iface_exists = 0;
372 return;
373 }
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200374 }
375
376#if 0 /* why do we mess with IP addr? It's not our business */
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 /* bloat */
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 /* Get MAC */
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
James Byrne253c4e72019-04-12 17:01:51 +0000416 bb_info_msg("using interface %s%s with driver<%s> (version: %s)",
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200417 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
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200424static smallint detect_link(void)
Denis Vlasenko71c16572009-04-26 01:08:51 +0000425{
Denis Vlasenko71c16572009-04-26 01:08:51 +0000426 smallint status;
427
428 if (!G.iface_exists)
429 return (option_mask32 & FLAG_MONITOR) ? IFSTATUS_DOWN : IFSTATUS_ERR;
430
Denys Vlasenkof422a722010-01-08 12:27:57 +0100431 /* Some drivers can't detect link status when the interface is down.
432 * I imagine detect_link_iff() is the most vulnerable.
433 * That's why -a "noauto" in an option, not a hardwired behavior.
434 */
Denis Vlasenko71c16572009-04-26 01:08:51 +0000435 if (!(option_mask32 & FLAG_NO_AUTO))
436 up_iface();
Denis Vlasenko71c16572009-04-26 01:08:51 +0000437
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200438 if (G.api_method_num == API_AUTO) {
439 int i;
440 smallint sv_logmode;
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200441
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200442 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;
James Byrne253c4e72019-04-12 17:01:51 +0000449 bb_info_msg("using %s detection mode", method_table[i].name);
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200450 break;
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200451 }
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200452 }
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200453 } else {
454 status = method_table[G.api_method_num].func();
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200455 }
456
Denis Vlasenko71c16572009-04-26 01:08:51 +0000457 if (status == IFSTATUS_ERR) {
458 if (option_mask32 & FLAG_IGNORE_FAIL)
459 status = IFSTATUS_DOWN;
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200460 else if (option_mask32 & FLAG_IGNORE_FAIL_POSITIVE)
Denis Vlasenko71c16572009-04-26 01:08:51 +0000461 status = IFSTATUS_UP;
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200462 else if (G.api_mode[0] == 'a')
James Byrne69374872019-07-02 11:35:03 +0200463 bb_simple_error_msg("can't detect link status");
Denis Vlasenko71c16572009-04-26 01:08:51 +0000464 }
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200465
Denis Vlasenko71c16572009-04-26 01:08:51 +0000466 if (status != G.iface_last_status) {
Denys Vlasenko19afe842010-05-08 23:26:16 +0200467 G.iface_prev_status = G.iface_last_status;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000468 G.iface_last_status = status;
469 }
470
471 return status;
472}
473
474static NOINLINE int check_existence_through_netlink(void)
475{
Denys Vlasenko37201212010-04-02 07:04:44 +0200476 int iface_len;
Tito Ragusada331d72013-08-04 18:08:40 +0200477 /* Buffer was 1K, but on linux-3.9.9 it was reported to be too small.
478 * netlink.h: "limit to 8K to avoid MSG_TRUNC when PAGE_SIZE is very large".
479 * Note: on error returns (-1) we exit, no need to free replybuf.
480 */
481 enum { BUF_SIZE = 8 * 1024 };
482 char *replybuf = xmalloc(BUF_SIZE);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000483
Denys Vlasenko37201212010-04-02 07:04:44 +0200484 iface_len = strlen(G.iface);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000485 while (1) {
486 struct nlmsghdr *mhdr;
487 ssize_t bytes;
488
Tito Ragusada331d72013-08-04 18:08:40 +0200489 bytes = recv(netlink_fd, replybuf, BUF_SIZE, MSG_DONTWAIT);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000490 if (bytes < 0) {
491 if (errno == EAGAIN)
Tito Ragusada331d72013-08-04 18:08:40 +0200492 goto ret;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000493 if (errno == EINTR)
494 continue;
James Byrne69374872019-07-02 11:35:03 +0200495 bb_simple_perror_msg("netlink: recv");
Denis Vlasenko71c16572009-04-26 01:08:51 +0000496 return -1;
497 }
498
499 mhdr = (struct nlmsghdr*)replybuf;
500 while (bytes > 0) {
Maxim Kryzhanovsky2004fa12010-03-30 15:49:57 +0200501 if (!NLMSG_OK(mhdr, bytes)) {
James Byrne69374872019-07-02 11:35:03 +0200502 bb_simple_error_msg("netlink packet too small or truncated");
Denis Vlasenko71c16572009-04-26 01:08:51 +0000503 return -1;
504 }
505
506 if (mhdr->nlmsg_type == RTM_NEWLINK || mhdr->nlmsg_type == RTM_DELLINK) {
507 struct rtattr *attr;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000508 int attr_len;
509
Denis Vlasenko71c16572009-04-26 01:08:51 +0000510 if (mhdr->nlmsg_len < NLMSG_LENGTH(sizeof(struct ifinfomsg))) {
James Byrne69374872019-07-02 11:35:03 +0200511 bb_simple_error_msg("netlink packet too small or truncated");
Denis Vlasenko71c16572009-04-26 01:08:51 +0000512 return -1;
513 }
514
Maxim Kryzhanovsky2004fa12010-03-30 15:49:57 +0200515 attr = IFLA_RTA(NLMSG_DATA(mhdr));
516 attr_len = IFLA_PAYLOAD(mhdr);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000517
518 while (RTA_OK(attr, attr_len)) {
519 if (attr->rta_type == IFLA_IFNAME) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000520 int len = RTA_PAYLOAD(attr);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000521 if (len > IFNAMSIZ)
522 len = IFNAMSIZ;
Denys Vlasenko37201212010-04-02 07:04:44 +0200523 if (iface_len <= len
524 && strncmp(G.iface, RTA_DATA(attr), len) == 0
525 ) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000526 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
Tito Ragusada331d72013-08-04 18:08:40 +0200537 ret:
538 free(replybuf);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000539 return G.iface_exists;
540}
541
Denys Vlasenko9c35a1c2009-05-01 09:04:25 +0200542#if ENABLE_FEATURE_PIDFILE
Denis Vlasenko71c16572009-04-26 01:08:51 +0000543static 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 /* returns ULONG_MAX on error => -1 */
552 return bb_strtoul(buf, NULL, 10);
553 }
554 return 0;
555}
Denys Vlasenko9c35a1c2009-05-01 09:04:25 +0200556#endif
Denis Vlasenko71c16572009-04-26 01:08:51 +0000557
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;
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200566 const char *api_mode_found;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000567#if ENABLE_FEATURE_PIDFILE
568 char *pidfile_name;
569 pid_t pid_from_pidfile;
570#endif
571
572 INIT_G();
573
Denis Vlasenko71c16572009-04-26 01:08:51 +0000574 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);
Denys Vlasenko5a34d022009-11-07 17:30:14 +0100577 G.poll_time *= 1000;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000578
579 applet_name = xasprintf("ifplugd(%s)", G.iface);
580
581#if ENABLE_FEATURE_PIDFILE
Anthony G. Basile12677ac2012-12-10 14:49:39 -0500582 pidfile_name = xasprintf(CONFIG_PID_FILE_PATH "/ifplugd.%s.pid", G.iface);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000583 pid_from_pidfile = read_pid(pidfile_name);
584
585 if (opts & FLAG_KILL) {
586 if (pid_from_pidfile > 0)
Denys Vlasenko216e9522013-02-28 12:50:09 +0100587 /* Upstream tool use SIGINT for -k */
588 kill(pid_from_pidfile, SIGINT);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000589 return EXIT_SUCCESS;
590 }
591
592 if (pid_from_pidfile > 0 && kill(pid_from_pidfile, 0) == 0)
James Byrne69374872019-07-02 11:35:03 +0200593 bb_simple_error_msg_and_die("daemon already running");
Denis Vlasenko71c16572009-04-26 01:08:51 +0000594#endif
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200595
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200596 api_mode_found = strchr(api_modes, G.api_mode[0]);
597 if (!api_mode_found)
Denis Vlasenko71c16572009-04-26 01:08:51 +0000598 bb_error_msg_and_die("unknown API mode '%s'", G.api_mode);
Maksym Kryzhanovskyy9388b4e2010-07-08 02:47:25 +0200599 G.api_method_num = api_mode_found - api_modes;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000600
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) {
Denys Vlasenko45e39672019-06-03 14:16:52 +0200606 int fd = create_and_bind_to_netlink(NETLINK_ROUTE, RTMGRP_LINK, 0);
Maksym Kryzhanovskyy4f0279b2010-07-22 02:18:05 +0200607 xmove_fd(fd, netlink_fd);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000608 }
609
610 write_pidfile(pidfile_name);
611
612 /* this can't be moved before socket creation */
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 ) /* why we ignore it? */
623 /* | (1 << SIGCHLD) - run_script does not use it anymore */
624 , record_signo);
625
James Byrne253c4e72019-04-12 17:01:51 +0000626 bb_info_msg("started: %s", bb_banner);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000627
628 if (opts & FLAG_MONITOR) {
629 struct ifreq ifrequest;
630 set_ifreq_to_ifname(&ifrequest);
Denys Vlasenkof422a722010-01-08 12:27:57 +0100631 G.iface_exists = (network_ioctl(SIOCGIFINDEX, &ifrequest, NULL) == 0);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000632 }
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) {
James Byrne253c4e72019-04-12 17:01:51 +0000643 bb_info_msg("interface %s",
Denis Vlasenko71c16572009-04-26 01:08:51 +0000644 G.iface_exists ? "exists"
645 : "doesn't exist, waiting");
646 }
647 /* else we assume it always exists, but don't mislead user
648 * by potentially lying that it really exists */
649
650 if (G.iface_exists) {
James Byrne253c4e72019-04-12 17:01:51 +0000651 bb_info_msg("link is %s", iface_status_str);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000652 }
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 /* Main loop */
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;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000669
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;
Denys Vlasenkobc2e70b2018-04-29 13:46:49 +0200680 /* do not clear bb_got_signal if already 0, this can lose signals */
681 case 0:
Denis Vlasenko71c16572009-04-26 01:08:51 +0000682 break;
683 }
684
685 if (poll(netlink_pollfd,
686 (opts & FLAG_MONITOR) ? 1 : 0,
Denys Vlasenko5a34d022009-11-07 17:30:14 +0100687 G.poll_time
Denis Vlasenko71c16572009-04-26 01:08:51 +0000688 ) < 0
689 ) {
690 if (errno == EINTR)
691 continue;
James Byrne69374872019-07-02 11:35:03 +0200692 bb_simple_perror_msg("poll");
Denis Vlasenko71c16572009-04-26 01:08:51 +0000693 goto exiting;
694 }
695
Denis Vlasenko71c16572009-04-26 01:08:51 +0000696 if ((opts & FLAG_MONITOR)
697 && (netlink_pollfd[0].revents & POLLIN)
698 ) {
Denys Vlasenko50e4cc22014-02-10 09:44:25 +0100699 int iface_exists_old;
700
701 iface_exists_old = G.iface_exists;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000702 G.iface_exists = check_existence_through_netlink();
703 if (G.iface_exists < 0) /* error */
704 goto exiting;
705 if (iface_exists_old != G.iface_exists) {
James Byrne253c4e72019-04-12 17:01:51 +0000706 bb_info_msg("interface %sappeared",
Denis Vlasenko71c16572009-04-26 01:08:51 +0000707 G.iface_exists ? "" : "dis");
708 if (G.iface_exists)
709 maybe_up_new_iface();
710 }
711 }
712
713 /* note: if !G.iface_exists, returns DOWN */
Denys Vlasenko50e4cc22014-02-10 09:44:25 +0100714 iface_status_old = iface_status;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000715 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) {
James Byrne253c4e72019-04-12 17:01:51 +0000724 bb_info_msg("link is %s", iface_status_str);
Denis Vlasenko71c16572009-04-26 01:08:51 +0000725
726 if (delay_time) {
727 /* link restored its old status before
Denys Vlasenko50e4cc22014-02-10 09:44:25 +0100728 * we ran script. don't run the script: */
Denis Vlasenko71c16572009-04-26 01:08:51 +0000729 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;
Denys Vlasenko50e4cc22014-02-10 09:44:25 +0100736#if 0 /* if you are back in 1970... */
737 if (delay_time == 0) {
Denys Vlasenkoec16c032020-11-29 11:37:34 +0100738 sleep1();
Denys Vlasenko50e4cc22014-02-10 09:44:25 +0100739 delay_time = 1;
740 }
741#endif
Denis Vlasenko71c16572009-04-26 01:08:51 +0000742 }
743 }
744
745 if (delay_time && (int)(monotonic_sec() - delay_time) >= 0) {
Denis Vlasenko71c16572009-04-26 01:08:51 +0000746 if (run_script(iface_status_str) != 0)
747 goto exiting;
Denys Vlasenko50e4cc22014-02-10 09:44:25 +0100748 delay_time = 0;
Denis Vlasenko71c16572009-04-26 01:08:51 +0000749 }
750 } /* while (1) */
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"); /* reusing string */
761 }
762
763 exiting:
764 remove_pidfile(pidfile_name);
James Byrne69374872019-07-02 11:35:03 +0200765 bb_simple_error_msg_and_die("exiting");
Denis Vlasenko71c16572009-04-26 01:08:51 +0000766}