chiark / gitweb /
0b6db30edad4f56d0a5471e0abe06a671a242d25
[elogind.git] / src / udev-event.c
1 /*
2  * Copyright (C) 2003-2010 Kay Sievers <kay.sievers@vrfy.org>
3  *
4  * This program is free software: you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation, either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17
18 #include <stdlib.h>
19 #include <stdio.h>
20 #include <stddef.h>
21 #include <unistd.h>
22 #include <fcntl.h>
23 #include <errno.h>
24 #include <ctype.h>
25 #include <string.h>
26 #include <time.h>
27 #include <net/if.h>
28 #include <sys/ioctl.h>
29 #include <sys/prctl.h>
30 #include <sys/poll.h>
31 #include <sys/epoll.h>
32 #include <sys/wait.h>
33 #include <sys/socket.h>
34 #include <sys/signalfd.h>
35 #include <linux/sockios.h>
36
37 #include "udev.h"
38
39 struct udev_event *udev_event_new(struct udev_device *dev)
40 {
41         struct udev *udev = udev_device_get_udev(dev);
42         struct udev_event *event;
43
44         event = calloc(1, sizeof(struct udev_event));
45         if (event == NULL)
46                 return NULL;
47         event->dev = dev;
48         event->udev = udev;
49         udev_list_init(udev, &event->run_list, false);
50         event->fd_signal = -1;
51         event->birth_usec = now_usec();
52         event->timeout_usec = 30 * 1000 * 1000;
53         dbg(event->udev, "allocated event %p\n", event);
54         return event;
55 }
56
57 void udev_event_unref(struct udev_event *event)
58 {
59         if (event == NULL)
60                 return;
61         udev_list_cleanup(&event->run_list);
62         free(event->program_result);
63         free(event->name);
64         dbg(event->udev, "free event %p\n", event);
65         free(event);
66 }
67
68 size_t udev_event_apply_format(struct udev_event *event, const char *src, char *dest, size_t size)
69 {
70         struct udev_device *dev = event->dev;
71         enum subst_type {
72                 SUBST_UNKNOWN,
73                 SUBST_DEVNODE,
74                 SUBST_ATTR,
75                 SUBST_ENV,
76                 SUBST_KERNEL,
77                 SUBST_KERNEL_NUMBER,
78                 SUBST_DRIVER,
79                 SUBST_DEVPATH,
80                 SUBST_ID,
81                 SUBST_MAJOR,
82                 SUBST_MINOR,
83                 SUBST_RESULT,
84                 SUBST_PARENT,
85                 SUBST_NAME,
86                 SUBST_LINKS,
87                 SUBST_ROOT,
88                 SUBST_SYS,
89         };
90         static const struct subst_map {
91                 char *name;
92                 char fmt;
93                 enum subst_type type;
94         } map[] = {
95                 { .name = "devnode",        .fmt = 'N',        .type = SUBST_DEVNODE },
96                 { .name = "tempnode",        .fmt = 'N',        .type = SUBST_DEVNODE },
97                 { .name = "attr",        .fmt = 's',        .type = SUBST_ATTR },
98                 { .name = "sysfs",        .fmt = 's',        .type = SUBST_ATTR },
99                 { .name = "env",        .fmt = 'E',        .type = SUBST_ENV },
100                 { .name = "kernel",        .fmt = 'k',        .type = SUBST_KERNEL },
101                 { .name = "number",        .fmt = 'n',        .type = SUBST_KERNEL_NUMBER },
102                 { .name = "driver",        .fmt = 'd',        .type = SUBST_DRIVER },
103                 { .name = "devpath",        .fmt = 'p',        .type = SUBST_DEVPATH },
104                 { .name = "id",                .fmt = 'b',        .type = SUBST_ID },
105                 { .name = "major",        .fmt = 'M',        .type = SUBST_MAJOR },
106                 { .name = "minor",        .fmt = 'm',        .type = SUBST_MINOR },
107                 { .name = "result",        .fmt = 'c',        .type = SUBST_RESULT },
108                 { .name = "parent",        .fmt = 'P',        .type = SUBST_PARENT },
109                 { .name = "name",        .fmt = 'D',        .type = SUBST_NAME },
110                 { .name = "links",        .fmt = 'L',        .type = SUBST_LINKS },
111                 { .name = "root",        .fmt = 'r',        .type = SUBST_ROOT },
112                 { .name = "sys",        .fmt = 'S',        .type = SUBST_SYS },
113         };
114         const char *from;
115         char *s;
116         size_t l;
117
118         from = src;
119         s = dest;
120         l = size;
121
122         for (;;) {
123                 enum subst_type type = SUBST_UNKNOWN;
124                 char attrbuf[UTIL_PATH_SIZE];
125                 char *attr = NULL;
126
127                 while (from[0] != '\0') {
128                         if (from[0] == '$') {
129                                 /* substitute named variable */
130                                 unsigned int i;
131
132                                 if (from[1] == '$') {
133                                         from++;
134                                         goto copy;
135                                 }
136
137                                 for (i = 0; i < ARRAY_SIZE(map); i++) {
138                                         if (strncmp(&from[1], map[i].name, strlen(map[i].name)) == 0) {
139                                                 type = map[i].type;
140                                                 from += strlen(map[i].name)+1;
141                                                 dbg(event->udev, "will substitute format name '%s'\n", map[i].name);
142                                                 goto subst;
143                                         }
144                                 }
145                         } else if (from[0] == '%') {
146                                 /* substitute format char */
147                                 unsigned int i;
148
149                                 if (from[1] == '%') {
150                                         from++;
151                                         goto copy;
152                                 }
153
154                                 for (i = 0; i < ARRAY_SIZE(map); i++) {
155                                         if (from[1] == map[i].fmt) {
156                                                 type = map[i].type;
157                                                 from += 2;
158                                                 dbg(event->udev, "will substitute format char '%c'\n", map[i].fmt);
159                                                 goto subst;
160                                         }
161                                 }
162                         }
163 copy:
164                         /* copy char */
165                         if (l == 0)
166                                 goto out;
167                         s[0] = from[0];
168                         from++;
169                         s++;
170                         l--;
171                 }
172
173                 goto out;
174 subst:
175                 /* extract possible $format{attr} */
176                 if (from[0] == '{') {
177                         unsigned int i;
178
179                         from++;
180                         for (i = 0; from[i] != '}'; i++) {
181                                 if (from[i] == '\0') {
182                                         err(event->udev, "missing closing brace for format '%s'\n", src);
183                                         goto out;
184                                 }
185                         }
186                         if (i >= sizeof(attrbuf))
187                                 goto out;
188                         memcpy(attrbuf, from, i);
189                         attrbuf[i] = '\0';
190                         from += i+1;
191                         attr = attrbuf;
192                 } else {
193                         attr = NULL;
194                 }
195
196                 switch (type) {
197                 case SUBST_DEVPATH:
198                         l = util_strpcpy(&s, l, udev_device_get_devpath(dev));
199                         dbg(event->udev, "substitute devpath '%s'\n", udev_device_get_devpath(dev));
200                         break;
201                 case SUBST_KERNEL:
202                         l = util_strpcpy(&s, l, udev_device_get_sysname(dev));
203                         dbg(event->udev, "substitute kernel name '%s'\n", udev_device_get_sysname(dev));
204                         break;
205                 case SUBST_KERNEL_NUMBER:
206                         if (udev_device_get_sysnum(dev) == NULL)
207                                 break;
208                         l = util_strpcpy(&s, l, udev_device_get_sysnum(dev));
209                         dbg(event->udev, "substitute kernel number '%s'\n", udev_device_get_sysnum(dev));
210                         break;
211                 case SUBST_ID:
212                         if (event->dev_parent == NULL)
213                                 break;
214                         l = util_strpcpy(&s, l, udev_device_get_sysname(event->dev_parent));
215                         dbg(event->udev, "substitute id '%s'\n", udev_device_get_sysname(event->dev_parent));
216                         break;
217                 case SUBST_DRIVER: {
218                         const char *driver;
219
220                         if (event->dev_parent == NULL)
221                                 break;
222
223                         driver = udev_device_get_driver(event->dev_parent);
224                         if (driver == NULL)
225                                 break;
226                         l = util_strpcpy(&s, l, driver);
227                         dbg(event->udev, "substitute driver '%s'\n", driver);
228                         break;
229                 }
230                 case SUBST_MAJOR: {
231                         char num[UTIL_PATH_SIZE];
232
233                         sprintf(num, "%d", major(udev_device_get_devnum(dev)));
234                         l = util_strpcpy(&s, l, num);
235                         dbg(event->udev, "substitute major number '%s'\n", num);
236                         break;
237                 }
238                 case SUBST_MINOR: {
239                         char num[UTIL_PATH_SIZE];
240
241                         sprintf(num, "%d", minor(udev_device_get_devnum(dev)));
242                         l = util_strpcpy(&s, l, num);
243                         dbg(event->udev, "substitute minor number '%s'\n", num);
244                         break;
245                 }
246                 case SUBST_RESULT: {
247                         char *rest;
248                         int i;
249
250                         if (event->program_result == NULL)
251                                 break;
252                         /* get part part of the result string */
253                         i = 0;
254                         if (attr != NULL)
255                                 i = strtoul(attr, &rest, 10);
256                         if (i > 0) {
257                                 char result[UTIL_PATH_SIZE];
258                                 char tmp[UTIL_PATH_SIZE];
259                                 char *cpos;
260
261                                 dbg(event->udev, "request part #%d of result string\n", i);
262                                 util_strscpy(result, sizeof(result), event->program_result);
263                                 cpos = result;
264                                 while (--i) {
265                                         while (cpos[0] != '\0' && !isspace(cpos[0]))
266                                                 cpos++;
267                                         while (isspace(cpos[0]))
268                                                 cpos++;
269                                 }
270                                 if (i > 0) {
271                                         err(event->udev, "requested part of result string not found\n");
272                                         break;
273                                 }
274                                 util_strscpy(tmp, sizeof(tmp), cpos);
275                                 /* %{2+}c copies the whole string from the second part on */
276                                 if (rest[0] != '+') {
277                                         cpos = strchr(tmp, ' ');
278                                         if (cpos)
279                                                 cpos[0] = '\0';
280                                 }
281                                 l = util_strpcpy(&s, l, tmp);
282                                 dbg(event->udev, "substitute part of result string '%s'\n", tmp);
283                         } else {
284                                 l = util_strpcpy(&s, l, event->program_result);
285                                 dbg(event->udev, "substitute result string '%s'\n", event->program_result);
286                         }
287                         break;
288                 }
289                 case SUBST_ATTR: {
290                         const char *value = NULL;
291                         char vbuf[UTIL_NAME_SIZE];
292                         size_t len;
293                         int count;
294
295                         if (attr == NULL) {
296                                 err(event->udev, "missing file parameter for attr\n");
297                                 break;
298                         }
299
300                         /* try to read the value specified by "[dmi/id]product_name" */
301                         if (util_resolve_subsys_kernel(event->udev, attr, vbuf, sizeof(vbuf), 1) == 0)
302                                 value = vbuf;
303
304                         /* try to read the attribute the device */
305                         if (value == NULL)
306                                 value = udev_device_get_sysattr_value(event->dev, attr);
307
308                         /* try to read the attribute of the parent device, other matches have selected */
309                         if (value == NULL && event->dev_parent != NULL && event->dev_parent != event->dev)
310                                 value = udev_device_get_sysattr_value(event->dev_parent, attr);
311
312                         if (value == NULL)
313                                 break;
314
315                         /* strip trailing whitespace, and replace unwanted characters */
316                         if (value != vbuf)
317                                 util_strscpy(vbuf, sizeof(vbuf), value);
318                         len = strlen(vbuf);
319                         while (len > 0 && isspace(vbuf[--len]))
320                                 vbuf[len] = '\0';
321                         count = util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT);
322                         if (count > 0)
323                                 info(event->udev, "%i character(s) replaced\n" , count);
324                         l = util_strpcpy(&s, l, vbuf);
325                         dbg(event->udev, "substitute sysfs value '%s'\n", vbuf);
326                         break;
327                 }
328                 case SUBST_PARENT: {
329                         struct udev_device *dev_parent;
330                         const char *devnode;
331
332                         dev_parent = udev_device_get_parent(event->dev);
333                         if (dev_parent == NULL)
334                                 break;
335                         devnode = udev_device_get_devnode(dev_parent);
336                         if (devnode != NULL) {
337                                 size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
338
339                                 l = util_strpcpy(&s, l, &devnode[devlen]);
340                                 dbg(event->udev, "found parent '%s', got node name '%s'\n",
341                                     udev_device_get_syspath(dev_parent), &devnode[devlen]);
342                         }
343                         break;
344                 }
345                 case SUBST_DEVNODE:
346                         if (udev_device_get_devnode(dev) != NULL)
347                                 l = util_strpcpy(&s, l, udev_device_get_devnode(dev));
348                         break;
349                 case SUBST_NAME: {
350                         if (event->name != NULL) {
351                                 l = util_strpcpy(&s, l, event->name);
352                                 dbg(event->udev, "substitute custom name '%s'\n", event->name);
353                         } else {
354                                 size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
355
356                                 l = util_strpcpy(&s, l, &udev_device_get_devnode(dev)[devlen]);
357                                 dbg(event->udev, "substitute name'%s'\n", &udev_device_get_devnode(dev)[devlen]);
358                         }
359                         break;
360                 }
361                 case SUBST_LINKS: {
362                         size_t devlen = strlen(udev_get_dev_path(event->udev))+1;
363                         struct udev_list_entry *list_entry;
364
365                         list_entry = udev_device_get_devlinks_list_entry(dev);
366                         if (list_entry == NULL)
367                                 break;
368                         l = util_strpcpy(&s, l, &udev_list_entry_get_name(list_entry)[devlen]);
369                         udev_list_entry_foreach(list_entry, udev_list_entry_get_next(list_entry))
370                                 l = util_strpcpyl(&s, l, " ", &udev_list_entry_get_name(list_entry)[devlen], NULL);
371                         break;
372                 }
373                 case SUBST_ROOT:
374                         l = util_strpcpy(&s, l, udev_get_dev_path(event->udev));
375                         dbg(event->udev, "substitute udev_root '%s'\n", udev_get_dev_path(event->udev));
376                         break;
377                 case SUBST_SYS:
378                         l = util_strpcpy(&s, l, udev_get_sys_path(event->udev));
379                         dbg(event->udev, "substitute sys_path '%s'\n", udev_get_sys_path(event->udev));
380                         break;
381                 case SUBST_ENV:
382                         if (attr == NULL) {
383                                 dbg(event->udev, "missing attribute\n");
384                                 break;
385                         } else {
386                                 const char *value;
387
388                                 value = udev_device_get_property_value(event->dev, attr);
389                                 if (value == NULL)
390                                         break;
391                                 dbg(event->udev, "substitute env '%s=%s'\n", attr, value);
392                                 l = util_strpcpy(&s, l, value);
393                                 break;
394                         }
395                 default:
396                         err(event->udev, "unknown substitution type=%i\n", type);
397                         break;
398                 }
399         }
400
401 out:
402         s[0] = '\0';
403         dbg(event->udev, "'%s' -> '%s' (%zu)\n", src, dest, l);
404         return l;
405 }
406
407 static int spawn_exec(struct udev_event *event,
408                       const char *cmd, char *const argv[], char **envp, const sigset_t *sigmask,
409                       int fd_stdout, int fd_stderr)
410 {
411         struct udev *udev = event->udev;
412         int err;
413         int fd;
414
415         /* discard child output or connect to pipe */
416         fd = open("/dev/null", O_RDWR);
417         if (fd >= 0) {
418                 dup2(fd, STDIN_FILENO);
419                 if (fd_stdout < 0)
420                         dup2(fd, STDOUT_FILENO);
421                 if (fd_stderr < 0)
422                         dup2(fd, STDERR_FILENO);
423                 close(fd);
424         } else {
425                 err(udev, "open /dev/null failed: %m\n");
426         }
427
428         /* connect pipes to std{out,err} */
429         if (fd_stdout >= 0) {
430                 dup2(fd_stdout, STDOUT_FILENO);
431                         close(fd_stdout);
432         }
433         if (fd_stderr >= 0) {
434                 dup2(fd_stderr, STDERR_FILENO);
435                 close(fd_stderr);
436         }
437
438         /* terminate child in case parent goes away */
439         prctl(PR_SET_PDEATHSIG, SIGTERM);
440
441         /* restore original udev sigmask before exec */
442         if (sigmask)
443                 sigprocmask(SIG_SETMASK, sigmask, NULL);
444
445         execve(argv[0], argv, envp);
446
447         /* exec failed */
448         err = -errno;
449         err(udev, "failed to execute '%s' '%s': %m\n", argv[0], cmd);
450         return err;
451 }
452
453 static void spawn_read(struct udev_event *event,
454                       const char *cmd,
455                       int fd_stdout, int fd_stderr,
456                       char *result, size_t ressize)
457 {
458         struct udev *udev = event->udev;
459         size_t respos = 0;
460         int fd_ep = -1;
461         struct epoll_event ep_outpipe, ep_errpipe;
462
463         /* read from child if requested */
464         if (fd_stdout < 0 && fd_stderr < 0)
465                 return;
466
467         fd_ep = epoll_create1(EPOLL_CLOEXEC);
468         if (fd_ep < 0) {
469                 err(udev, "error creating epoll fd: %m\n");
470                 goto out;
471         }
472
473         if (fd_stdout >= 0) {
474                 memset(&ep_outpipe, 0, sizeof(struct epoll_event));
475                 ep_outpipe.events = EPOLLIN;
476                 ep_outpipe.data.ptr = &fd_stdout;
477                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stdout, &ep_outpipe) < 0) {
478                         err(udev, "fail to add fd to epoll: %m\n");
479                         goto out;
480                 }
481         }
482
483         if (fd_stderr >= 0) {
484                 memset(&ep_errpipe, 0, sizeof(struct epoll_event));
485                 ep_errpipe.events = EPOLLIN;
486                 ep_errpipe.data.ptr = &fd_stderr;
487                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_stderr, &ep_errpipe) < 0) {
488                         err(udev, "fail to add fd to epoll: %m\n");
489                         goto out;
490                 }
491         }
492
493         /* read child output */
494         while (fd_stdout >= 0 || fd_stderr >= 0) {
495                 int timeout;
496                 int fdcount;
497                 struct epoll_event ev[4];
498                 int i;
499
500                 if (event->timeout_usec > 0) {
501                         unsigned long long age_usec;
502
503                         age_usec = now_usec() - event->birth_usec;
504                         if (age_usec >= event->timeout_usec) {
505                                 err(udev, "timeout '%s'\n", cmd);
506                                 goto out;
507                         }
508                         timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
509                 } else {
510                         timeout = -1;
511                 }
512
513                 fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
514                 if (fdcount < 0) {
515                         if (errno == EINTR)
516                                 continue;
517                         err(udev, "failed to poll: %m\n");
518                         goto out;
519                 }
520                 if (fdcount == 0) {
521                         err(udev, "timeout '%s'\n", cmd);
522                         goto out;
523                 }
524
525                 for (i = 0; i < fdcount; i++) {
526                         int *fd = (int *)ev[i].data.ptr;
527
528                         if (ev[i].events & EPOLLIN) {
529                                 ssize_t count;
530                                 char buf[4096];
531
532                                 count = read(*fd, buf, sizeof(buf)-1);
533                                 if (count <= 0)
534                                         continue;
535                                 buf[count] = '\0';
536
537                                 /* store stdout result */
538                                 if (result != NULL && *fd == fd_stdout) {
539                                         if (respos + count < ressize) {
540                                                 memcpy(&result[respos], buf, count);
541                                                 respos += count;
542                                         } else {
543                                                 err(udev, "'%s' ressize %zd too short\n", cmd, ressize);
544                                         }
545                                 }
546
547                                 /* log debug output only if we watch stderr */
548                                 if (fd_stderr >= 0) {
549                                         char *pos;
550                                         char *line;
551
552                                         pos = buf;
553                                         while ((line = strsep(&pos, "\n"))) {
554                                                 if (pos != NULL || line[0] != '\0')
555                                                         info(udev, "'%s'(%s) '%s'\n", cmd, *fd == fd_stdout ? "out" : "err" , line);
556                                         }
557                                 }
558                         } else if (ev[i].events & EPOLLHUP) {
559                                 if (epoll_ctl(fd_ep, EPOLL_CTL_DEL, *fd, NULL) < 0) {
560                                         err(udev, "failed to remove fd from epoll: %m\n");
561                                         goto out;
562                                 }
563                                 *fd = -1;
564                         }
565                 }
566         }
567
568         /* return the child's stdout string */
569         if (result != NULL) {
570                 result[respos] = '\0';
571                 dbg(udev, "result='%s'\n", result);
572         }
573 out:
574         if (fd_ep >= 0)
575                 close(fd_ep);
576 }
577
578 static int spawn_wait(struct udev_event *event, const char *cmd, pid_t pid)
579 {
580         struct udev *udev = event->udev;
581         struct pollfd pfd[1];
582         int err = 0;
583
584         pfd[0].events = POLLIN;
585         pfd[0].fd = event->fd_signal;
586
587         while (pid > 0) {
588                 int timeout;
589                 int fdcount;
590
591                 if (event->timeout_usec > 0) {
592                         unsigned long long age_usec;
593
594                         age_usec = now_usec() - event->birth_usec;
595                         if (age_usec >= event->timeout_usec)
596                                 timeout = 1000;
597                         else
598                                 timeout = ((event->timeout_usec - age_usec) / 1000) + 1000;
599                 } else {
600                         timeout = -1;
601                 }
602
603                 fdcount = poll(pfd, 1, timeout);
604                 if (fdcount < 0) {
605                         if (errno == EINTR)
606                                 continue;
607                         err = -errno;
608                         err(udev, "failed to poll: %m\n");
609                         goto out;
610                 }
611                 if (fdcount == 0) {
612                         err(udev, "timeout: killing '%s' [%u]\n", cmd, pid);
613                         kill(pid, SIGKILL);
614                 }
615
616                 if (pfd[0].revents & POLLIN) {
617                         struct signalfd_siginfo fdsi;
618                         int status;
619                         ssize_t size;
620
621                         size = read(event->fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
622                         if (size != sizeof(struct signalfd_siginfo))
623                                 continue;
624
625                         switch (fdsi.ssi_signo) {
626                         case SIGTERM:
627                                 event->sigterm = true;
628                                 break;
629                         case SIGCHLD:
630                                 if (waitpid(pid, &status, WNOHANG) < 0)
631                                         break;
632                                 if (WIFEXITED(status)) {
633                                         info(udev, "'%s' [%u] exit with return code %i\n", cmd, pid, WEXITSTATUS(status));
634                                         if (WEXITSTATUS(status) != 0)
635                                                 err = -1;
636                                 } else if (WIFSIGNALED(status)) {
637                                         err(udev, "'%s' [%u] terminated by signal %i (%s)\n", cmd, pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
638                                         err = -1;
639                                 } else if (WIFSTOPPED(status)) {
640                                         err(udev, "'%s' [%u] stopped\n", cmd, pid);
641                                         err = -1;
642                                 } else if (WIFCONTINUED(status)) {
643                                         err(udev, "'%s' [%u] continued\n", cmd, pid);
644                                         err = -1;
645                                 } else {
646                                         err(udev, "'%s' [%u] exit with status 0x%04x\n", cmd, pid, status);
647                                         err = -1;
648                                 }
649                                 pid = 0;
650                                 break;
651                         }
652                 }
653         }
654 out:
655         return err;
656 }
657
658 int udev_build_argv(struct udev *udev, char *cmd, int *argc, char *argv[])
659 {
660         int i = 0;
661         char *pos;
662
663         if (strchr(cmd, ' ') == NULL) {
664                 argv[i++] = cmd;
665                 goto out;
666         }
667
668         pos = cmd;
669         while (pos != NULL && pos[0] != '\0') {
670                 if (pos[0] == '\'') {
671                         /* do not separate quotes */
672                         pos++;
673                         argv[i] = strsep(&pos, "\'");
674                         if (pos != NULL)
675                                 while (pos[0] == ' ')
676                                         pos++;
677                 } else {
678                         argv[i] = strsep(&pos, " ");
679                         if (pos != NULL)
680                                 while (pos[0] == ' ')
681                                         pos++;
682                 }
683                 dbg(udev, "argv[%i] '%s'\n", i, argv[i]);
684                 i++;
685         }
686 out:
687         argv[i] = NULL;
688         if (argc)
689                 *argc = i;
690         return 0;
691 }
692
693 int udev_event_spawn(struct udev_event *event,
694                      const char *cmd, char **envp, const sigset_t *sigmask,
695                      char *result, size_t ressize)
696 {
697         struct udev *udev = event->udev;
698         int outpipe[2] = {-1, -1};
699         int errpipe[2] = {-1, -1};
700         pid_t pid;
701         char arg[UTIL_PATH_SIZE];
702         char *argv[128];
703         char program[UTIL_PATH_SIZE];
704         int err = 0;
705
706         util_strscpy(arg, sizeof(arg), cmd);
707         udev_build_argv(event->udev, arg, NULL, argv);
708
709         /* pipes from child to parent */
710         if (result != NULL || udev_get_log_priority(udev) >= LOG_INFO) {
711                 if (pipe2(outpipe, O_NONBLOCK) != 0) {
712                         err = -errno;
713                         err(udev, "pipe failed: %m\n");
714                         goto out;
715                 }
716         }
717         if (udev_get_log_priority(udev) >= LOG_INFO) {
718                 if (pipe2(errpipe, O_NONBLOCK) != 0) {
719                         err = -errno;
720                         err(udev, "pipe failed: %m\n");
721                         goto out;
722                 }
723         }
724
725         /* allow programs in /usr/lib/udev/ to be called without the path */
726         if (argv[0][0] != '/') {
727                 util_strscpyl(program, sizeof(program), PKGLIBEXECDIR "/", argv[0], NULL);
728                 argv[0] = program;
729         }
730
731         pid = fork();
732         switch(pid) {
733         case 0:
734                 /* child closes parent's ends of pipes */
735                 if (outpipe[READ_END] >= 0) {
736                         close(outpipe[READ_END]);
737                         outpipe[READ_END] = -1;
738                 }
739                 if (errpipe[READ_END] >= 0) {
740                         close(errpipe[READ_END]);
741                         errpipe[READ_END] = -1;
742                 }
743
744                 info(udev, "starting '%s'\n", cmd);
745
746                 err = spawn_exec(event, cmd, argv, envp, sigmask,
747                                  outpipe[WRITE_END], errpipe[WRITE_END]);
748
749                 _exit(2 );
750         case -1:
751                 err(udev, "fork of '%s' failed: %m\n", cmd);
752                 err = -1;
753                 goto out;
754         default:
755                 /* parent closed child's ends of pipes */
756                 if (outpipe[WRITE_END] >= 0) {
757                         close(outpipe[WRITE_END]);
758                         outpipe[WRITE_END] = -1;
759                 }
760                 if (errpipe[WRITE_END] >= 0) {
761                         close(errpipe[WRITE_END]);
762                         errpipe[WRITE_END] = -1;
763                 }
764
765                 spawn_read(event, cmd,
766                          outpipe[READ_END], errpipe[READ_END],
767                          result, ressize);
768
769                 err = spawn_wait(event, cmd, pid);
770         }
771
772 out:
773         if (outpipe[READ_END] >= 0)
774                 close(outpipe[READ_END]);
775         if (outpipe[WRITE_END] >= 0)
776                 close(outpipe[WRITE_END]);
777         if (errpipe[READ_END] >= 0)
778                 close(errpipe[READ_END]);
779         if (errpipe[WRITE_END] >= 0)
780                 close(errpipe[WRITE_END]);
781         return err;
782 }
783
784 static void rename_netif_kernel_log(struct ifreq ifr)
785 {
786         int klog;
787         FILE *f;
788
789         klog = open("/dev/kmsg", O_WRONLY);
790         if (klog < 0)
791                 return;
792
793         f = fdopen(klog, "w");
794         if (f == NULL) {
795                 close(klog);
796                 return;
797         }
798
799         fprintf(f, "<30>udevd[%u]: renamed network interface %s to %s\n",
800                 getpid(), ifr.ifr_name, ifr.ifr_newname);
801         fclose(f);
802 }
803
804 static int rename_netif(struct udev_event *event)
805 {
806         struct udev_device *dev = event->dev;
807         int sk;
808         struct ifreq ifr;
809         int loop;
810         int err;
811
812         info(event->udev, "changing net interface name from '%s' to '%s'\n",
813              udev_device_get_sysname(dev), event->name);
814
815         sk = socket(PF_INET, SOCK_DGRAM, 0);
816         if (sk < 0) {
817                 err = -errno;
818                 err(event->udev, "error opening socket: %m\n");
819                 return err;
820         }
821
822         memset(&ifr, 0x00, sizeof(struct ifreq));
823         util_strscpy(ifr.ifr_name, IFNAMSIZ, udev_device_get_sysname(dev));
824         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
825         err = ioctl(sk, SIOCSIFNAME, &ifr);
826         if (err == 0) {
827                 rename_netif_kernel_log(ifr);
828                 goto out;
829         }
830
831         /* keep trying if the destination interface name already exists */
832         err = -errno;
833         if (err != -EEXIST)
834                 goto out;
835
836         /* free our own name, another process may wait for us */
837         snprintf(ifr.ifr_newname, IFNAMSIZ, "rename%u", udev_device_get_ifindex(dev));
838         err = ioctl(sk, SIOCSIFNAME, &ifr);
839         if (err < 0) {
840                 err = -errno;
841                 goto out;
842         }
843
844         /* log temporary name */
845         rename_netif_kernel_log(ifr);
846
847         /* wait a maximum of 90 seconds for our target to become available */
848         util_strscpy(ifr.ifr_name, IFNAMSIZ, ifr.ifr_newname);
849         util_strscpy(ifr.ifr_newname, IFNAMSIZ, event->name);
850         loop = 90 * 20;
851         while (loop--) {
852                 const struct timespec duration = { 0, 1000 * 1000 * 1000 / 20 };
853
854                 dbg(event->udev, "wait for netif '%s' to become free, loop=%i\n",
855                     event->name, (90 * 20) - loop);
856                 nanosleep(&duration, NULL);
857
858                 err = ioctl(sk, SIOCSIFNAME, &ifr);
859                 if (err == 0) {
860                         rename_netif_kernel_log(ifr);
861                         break;
862                 }
863                 err = -errno;
864                 if (err != -EEXIST)
865                         break;
866         }
867
868 out:
869         if (err < 0)
870                 err(event->udev, "error changing net interface name %s to %s: %m\n", ifr.ifr_name, ifr.ifr_newname);
871         close(sk);
872         return err;
873 }
874
875 int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules, const sigset_t *sigmask)
876 {
877         struct udev_device *dev = event->dev;
878         int err = 0;
879
880         if (udev_device_get_subsystem(dev) == NULL)
881                 return -1;
882
883         if (strcmp(udev_device_get_action(dev), "remove") == 0) {
884                 udev_device_read_db(dev, NULL);
885                 udev_device_delete_db(dev);
886                 udev_device_tag_index(dev, NULL, false);
887
888                 if (major(udev_device_get_devnum(dev)) != 0)
889                         udev_watch_end(event->udev, dev);
890
891                 udev_rules_apply_to_event(rules, event, sigmask);
892
893                 if (major(udev_device_get_devnum(dev)) != 0)
894                         err = udev_node_remove(dev);
895         } else {
896                 event->dev_db = udev_device_new_from_syspath(event->udev, udev_device_get_syspath(dev));
897                 if (event->dev_db != NULL) {
898                         udev_device_read_db(event->dev_db, NULL);
899                         udev_device_set_info_loaded(event->dev_db);
900
901                         /* disable watch during event processing */
902                         if (major(udev_device_get_devnum(dev)) != 0)
903                                 udev_watch_end(event->udev, event->dev_db);
904                 }
905
906                 udev_rules_apply_to_event(rules, event, sigmask);
907
908                 /* rename a new network interface, if needed */
909                 if (udev_device_get_ifindex(dev) > 0 && strcmp(udev_device_get_action(dev), "add") == 0 &&
910                     event->name != NULL && strcmp(event->name, udev_device_get_sysname(dev)) != 0) {
911                         char syspath[UTIL_PATH_SIZE];
912                         char *pos;
913
914                         err = rename_netif(event);
915                         if (err == 0) {
916                                 info(event->udev, "renamed netif to '%s'\n", event->name);
917
918                                 /* remember old name */
919                                 udev_device_add_property(dev, "INTERFACE_OLD", udev_device_get_sysname(dev));
920
921                                 /* now change the devpath, because the kernel device name has changed */
922                                 util_strscpy(syspath, sizeof(syspath), udev_device_get_syspath(dev));
923                                 pos = strrchr(syspath, '/');
924                                 if (pos != NULL) {
925                                         pos++;
926                                         util_strscpy(pos, sizeof(syspath) - (pos - syspath), event->name);
927                                         udev_device_set_syspath(event->dev, syspath);
928                                         udev_device_add_property(dev, "INTERFACE", udev_device_get_sysname(dev));
929                                         info(event->udev, "changed devpath to '%s'\n", udev_device_get_devpath(dev));
930                                 }
931                         }
932                 }
933
934                 if (major(udev_device_get_devnum(dev)) > 0) {
935                         /* remove/update possible left-over symlinks from old database entry */
936                         if (event->dev_db != NULL)
937                                 udev_node_update_old_links(dev, event->dev_db);
938
939                         if (!event->mode_set) {
940                                 if (udev_device_get_devnode_mode(dev) > 0) {
941                                         /* kernel supplied value */
942                                         event->mode = udev_device_get_devnode_mode(dev);
943                                 } else if (event->gid > 0) {
944                                         /* default 0660 if a group is assigned */
945                                         event->mode = 0660;
946                                 } else {
947                                         /* default 0600 */
948                                         event->mode = 0600;
949                                 }
950                         }
951
952                         err = udev_node_add(dev, event->mode, event->uid, event->gid);
953                 }
954
955                 /* preserve old, or get new initialization timestamp */
956                 if (event->dev_db != NULL && udev_device_get_usec_initialized(event->dev_db) > 0)
957                         udev_device_set_usec_initialized(event->dev, udev_device_get_usec_initialized(event->dev_db));
958                 else if (udev_device_get_usec_initialized(event->dev) == 0)
959                         udev_device_set_usec_initialized(event->dev, now_usec());
960
961                 /* (re)write database file */
962                 udev_device_update_db(dev);
963                 udev_device_tag_index(dev, event->dev_db, true);
964                 udev_device_set_is_initialized(dev);
965
966                 udev_device_unref(event->dev_db);
967                 event->dev_db = NULL;
968         }
969 out:
970         return err;
971 }
972
973 int udev_event_execute_run(struct udev_event *event, const sigset_t *sigmask)
974 {
975         struct udev_list_entry *list_entry;
976         int err = 0;
977
978         dbg(event->udev, "executing run list\n");
979         udev_list_entry_foreach(list_entry, udev_list_get_entry(&event->run_list)) {
980                 const char *cmd = udev_list_entry_get_name(list_entry);
981
982                 if (strncmp(cmd, "socket:", strlen("socket:")) == 0) {
983                         struct udev_monitor *monitor;
984
985                         monitor = udev_monitor_new_from_socket(event->udev, &cmd[strlen("socket:")]);
986                         if (monitor == NULL)
987                                 continue;
988                         udev_monitor_send_device(monitor, NULL, event->dev);
989                         udev_monitor_unref(monitor);
990                 } else {
991                         char program[UTIL_PATH_SIZE];
992                         char **envp;
993
994                         if (event->exec_delay > 0) {
995                                 info(event->udev, "delay execution of '%s'\n", program);
996                                 sleep(event->exec_delay);
997                         }
998
999                         udev_event_apply_format(event, cmd, program, sizeof(program));
1000                         envp = udev_device_get_properties_envp(event->dev);
1001                         if (udev_event_spawn(event, program, envp, sigmask, NULL, 0) < 0) {
1002                                 if (udev_list_entry_get_num(list_entry))
1003                                         err = -1;
1004                         }
1005                 }
1006         }
1007         return err;
1008 }