procd: shift arguments for askfirst only once
[project/procd.git] / inittab.c
1 /*
2 * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
3 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License version 2.1
7 * as published by the Free Software Foundation
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
15 #define _GNU_SOURCE
16 #include <sys/types.h>
17 #include <sys/stat.h>
18 #include <sys/ioctl.h>
19
20 #include <fcntl.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <unistd.h>
24 #include <regex.h>
25 #include <ctype.h>
26
27 #include <libubox/utils.h>
28 #include <libubox/list.h>
29
30 #include "utils/utils.h"
31 #include "procd.h"
32 #include "rcS.h"
33
34 #ifndef O_PATH
35 #define O_PATH 010000000
36 #endif
37
38 #define TAG_ID 0
39 #define TAG_RUNLVL 1
40 #define TAG_ACTION 2
41 #define TAG_PROCESS 3
42
43 #define MAX_ARGS 8
44
45 struct init_action;
46 char *console = NULL;
47
48 struct init_handler {
49 const char *name;
50 void (*cb) (struct init_action *a);
51 int multi;
52 };
53
54 struct init_action {
55 struct list_head list;
56
57 char *id;
58 char *argv[MAX_ARGS];
59 char *line;
60
61 struct init_handler *handler;
62 struct uloop_process proc;
63
64 int respawn;
65 struct uloop_timeout tout;
66 };
67
68 static const char *tab = "/etc/inittab";
69 static char *ask = "/sbin/askfirst";
70
71 static LIST_HEAD(actions);
72
73 static int dev_exist(const char *dev)
74 {
75 int dfd, fd;
76
77 dfd = open("/dev", O_PATH|O_DIRECTORY);
78
79 if (dfd < 0)
80 return 0;
81
82 fd = openat(dfd, dev, O_RDONLY);
83 close(dfd);
84
85 if (fd < 0)
86 return 0;
87
88 close(fd);
89 return 1;
90 }
91
92 static void fork_worker(struct init_action *a)
93 {
94 pid_t p;
95
96 a->proc.pid = fork();
97 if (!a->proc.pid) {
98 p = setsid();
99
100 if (patch_stdio(a->id))
101 ERROR("Failed to setup i/o redirection\n");
102
103 ioctl(STDIN_FILENO, TIOCSCTTY, 1);
104 tcsetpgrp(STDIN_FILENO, p);
105
106 execvp(a->argv[0], a->argv);
107 ERROR("Failed to execute %s: %m\n", a->argv[0]);
108 exit(-1);
109 }
110
111 if (a->proc.pid > 0) {
112 DEBUG(4, "Launched new %s action, pid=%d\n",
113 a->handler->name,
114 (int) a->proc.pid);
115 uloop_process_add(&a->proc);
116 }
117 }
118
119 static void child_exit(struct uloop_process *proc, int ret)
120 {
121 struct init_action *a = container_of(proc, struct init_action, proc);
122
123 DEBUG(4, "pid:%d, exitcode:%d\n", proc->pid, ret);
124 proc->pid = 0;
125
126 if (!dev_exist(a->id)) {
127 DEBUG(4, "Skipping respawn: device '%s' does not exist anymore\n", a->id);
128 return;
129 }
130
131 uloop_timeout_set(&a->tout, a->respawn);
132 }
133
134 static void respawn(struct uloop_timeout *tout)
135 {
136 struct init_action *a = container_of(tout, struct init_action, tout);
137 if (!a->proc.pid)
138 fork_worker(a);
139 }
140
141 static void rcdone(struct runqueue *q)
142 {
143 procd_state_next();
144 }
145
146 static void runrc(struct init_action *a)
147 {
148 if (!a->argv[1] || !a->argv[2]) {
149 ERROR("valid format is rcS <S|K> <param>\n");
150 return;
151 }
152
153 /* proceed even if no init or shutdown scripts run */
154 if (rcS(a->argv[1], a->argv[2], rcdone))
155 rcdone(NULL);
156 }
157
158 static void askfirst(struct init_action *a)
159 {
160 int i;
161
162 if (!dev_exist(a->id) || (console && !strcmp(console, a->id))) {
163 DEBUG(4, "Skipping %s\n", a->id);
164 return;
165 }
166
167 a->tout.cb = respawn;
168 /* shift arguments only if not yet done */
169 if (a->argv[0] != ask) {
170 for (i = MAX_ARGS - 1; i >= 1; i--)
171 a->argv[i] = a->argv[i - 1];
172 a->argv[0] = ask;
173 }
174 a->respawn = 500;
175
176 a->proc.cb = child_exit;
177 if (!a->proc.pid)
178 fork_worker(a);
179 }
180
181 static void askconsole(struct init_action *a)
182 {
183 char line[256], *tty, *split;
184 int i;
185
186 tty = get_cmdline_val("console", line, sizeof(line));
187 if (tty != NULL) {
188 split = strchr(tty, ',');
189 if (split != NULL)
190 *split = '\0';
191
192 if (!dev_exist(tty)) {
193 DEBUG(4, "skipping %s\n", tty);
194 return;
195 }
196
197 console = strdup(tty);
198 a->id = strdup(tty);
199 }
200 else {
201 console = NULL;
202 a->id = NULL;
203 }
204
205 a->tout.cb = respawn;
206 /* shift arguments only if not yet done */
207 if (a->argv[0] != ask) {
208 for (i = MAX_ARGS - 1; i >= 1; i--)
209 a->argv[i] = a->argv[i - 1];
210 a->argv[0] = ask;
211 }
212 a->respawn = 500;
213
214 a->proc.cb = child_exit;
215 if (!a->proc.pid)
216 fork_worker(a);
217 }
218
219 static void rcrespawn(struct init_action *a)
220 {
221 a->tout.cb = respawn;
222 a->respawn = 500;
223
224 a->proc.cb = child_exit;
225 if (!a->proc.pid)
226 fork_worker(a);
227 }
228
229 static struct init_handler handlers[] = {
230 {
231 .name = "sysinit",
232 .cb = runrc,
233 }, {
234 .name = "shutdown",
235 .cb = runrc,
236 }, {
237 .name = "askfirst",
238 .cb = askfirst,
239 .multi = 1,
240 }, {
241 .name = "askconsole",
242 .cb = askconsole,
243 .multi = 1,
244 }, {
245 .name = "respawn",
246 .cb = rcrespawn,
247 .multi = 1,
248 }, {
249 .name = "askconsolelate",
250 .cb = askconsole,
251 .multi = 1,
252 }, {
253 .name = "respawnlate",
254 .cb = rcrespawn,
255 .multi = 1,
256 }
257 };
258
259 static int add_action(struct init_action *a, const char *name)
260 {
261 int i;
262
263 for (i = 0; i < ARRAY_SIZE(handlers); i++)
264 if (!strcmp(handlers[i].name, name)) {
265 a->handler = &handlers[i];
266 list_add_tail(&a->list, &actions);
267 return 0;
268 }
269 ERROR("Unknown init handler %s\n", name);
270 return -1;
271 }
272
273 void procd_inittab_run(const char *handler)
274 {
275 struct init_action *a;
276
277 list_for_each_entry(a, &actions, list)
278 if (!strcmp(a->handler->name, handler)) {
279 if (a->handler->multi) {
280 a->handler->cb(a);
281 continue;
282 }
283 a->handler->cb(a);
284 break;
285 }
286 }
287
288 void procd_inittab(void)
289 {
290 #define LINE_LEN 128
291 FILE *fp = fopen(tab, "r");
292 struct init_action *a;
293 regex_t pat_inittab;
294 regmatch_t matches[5];
295 char *line;
296
297 if (!fp) {
298 ERROR("Failed to open %s: %m\n", tab);
299 return;
300 }
301
302 regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
303 line = malloc(LINE_LEN);
304 a = calloc(1, sizeof(struct init_action));
305
306 while (fgets(line, LINE_LEN, fp)) {
307 char *tags[TAG_PROCESS + 1];
308 char *tok;
309 int i;
310 int len = strlen(line);
311
312 while (isspace(line[len - 1]))
313 len--;
314 line[len] = 0;
315
316 if (*line == '#')
317 continue;
318
319 if (regexec(&pat_inittab, line, 5, matches, 0))
320 continue;
321
322 DEBUG(4, "Parsing inittab - %s\n", line);
323
324 for (i = TAG_ID; i <= TAG_PROCESS; i++) {
325 line[matches[i].rm_eo] = '\0';
326 tags[i] = &line[matches[i + 1].rm_so];
327 };
328
329 tok = strtok(tags[TAG_PROCESS], " ");
330 for (i = 0; i < (MAX_ARGS - 1) && tok; i++) {
331 a->argv[i] = tok;
332 tok = strtok(NULL, " ");
333 }
334 a->argv[i] = NULL;
335 a->id = tags[TAG_ID];
336 a->line = line;
337
338 if (add_action(a, tags[TAG_ACTION]))
339 continue;
340 line = malloc(LINE_LEN);
341 a = calloc(1, sizeof(struct init_action));
342 }
343
344 fclose(fp);
345 free(line);
346 free(a);
347 regfree(&pat_inittab);
348 }