summaryrefslogtreecommitdiffstats
path: root/inittab.c
blob: 677ec47cfab886e11b1ccf37cca20deff5713f46 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
/*
 * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <sys/types.h>
#include <sys/stat.h>

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <regex.h>
#include <ctype.h>

#include <libubox/utils.h>
#include <libubox/list.h>

#include "procd.h"
#include "rcS.h"

#define TAG_ID		0
#define TAG_RUNLVL	1
#define TAG_ACTION	2
#define TAG_PROCESS	3

#define MAX_ARGS	8

struct init_action;
const char *console;

struct init_handler {
	const char *name;
	void (*cb) (struct init_action *a);
	int multi;
};

struct init_action {
	struct list_head list;

	char *id;
	char *argv[MAX_ARGS];
	char *line;

	struct init_handler *handler;
	struct uloop_process proc;

	int respawn;
	struct uloop_timeout tout;
};

static const char *tab = "/etc/inittab";
static char *ask = "/sbin/askfirst";

static LIST_HEAD(actions);

static void fork_worker(struct init_action *a)
{
	a->proc.pid = fork();
	if (!a->proc.pid) {
		execvp(a->argv[0], a->argv);
		ERROR("Failed to execute %s\n", a->argv[0]);
		exit(-1);
	}

	if (a->proc.pid > 0) {
		DEBUG(4, "Launched new %s action, pid=%d\n",
					a->handler->name,
					(int) a->proc.pid);
		uloop_process_add(&a->proc);
	}
}

static void child_exit(struct uloop_process *proc, int ret)
{
	struct init_action *a = container_of(proc, struct init_action, proc);

	DEBUG(4, "pid:%d\n", proc->pid);
        uloop_timeout_set(&a->tout, a->respawn);
}

static void respawn(struct uloop_timeout *tout)
{
	struct init_action *a = container_of(tout, struct init_action, tout);
	fork_worker(a);
}

static void rcdone(struct runqueue *q)
{
	procd_state_next();
}

static void runrc(struct init_action *a)
{
	if (!a->argv[1] || !a->argv[2]) {
		ERROR("valid format is rcS <S|K> <param>\n");
		return;
	}
	rcS(a->argv[1], a->argv[2], rcdone);
}

static void askfirst(struct init_action *a)
{
	struct stat s;
	int i;

	chdir("/dev");
	i = stat(a->id, &s);
	chdir("/");
	if (i || (console && !strcmp(console, a->id))) {
		DEBUG(4, "Skipping %s\n", a->id);
		return;
	}

	a->tout.cb = respawn;
	for (i = MAX_ARGS - 2; i >= 2; i--)
		a->argv[i] = a->argv[i - 2];
	a->argv[0] = ask;
	a->argv[1] = a->id;
	a->respawn = 500;

	a->proc.cb = child_exit;
	fork_worker(a);
}

static void askconsole(struct init_action *a)
{
	struct stat s;
	char line[256], *tty;
	int i, r, fd = open("/proc/cmdline", O_RDONLY);
	regex_t pat_cmdline;
	regmatch_t matches[2];

	if (fd < 0)
		return;

	r = read(fd, line, sizeof(line) - 1);
	line[r] = '\0';
	close(fd);

	regcomp(&pat_cmdline, "console=([a-zA-Z0-9]*)", REG_EXTENDED);
	if (regexec(&pat_cmdline, line, 2, matches, 0))
		goto err_out;
	line[matches[1].rm_eo] = '\0';
	tty = &line[matches[1].rm_so];

	chdir("/dev");
	i = stat(tty, &s);
	chdir("/");
	if (i) {
		DEBUG(4, "skipping %s\n", tty);
		goto err_out;
	}
	console = strdup(tty);

	a->tout.cb = respawn;
	for (i = MAX_ARGS - 2; i >= 2; i--)
		a->argv[i] = a->argv[i - 2];
	a->argv[0] = ask;
	a->argv[1] = strdup(tty);
	a->respawn = 500;

	a->proc.cb = child_exit;
	fork_worker(a);

err_out:
	regfree(&pat_cmdline);
}

static void rcrespawn(struct init_action *a)
{
	a->tout.cb = respawn;
	a->respawn = 500;

	a->proc.cb = child_exit;
	fork_worker(a);
}

static struct init_handler handlers[] = {
	{
		.name = "sysinit",
		.cb = runrc,
	}, {
		.name = "shutdown",
		.cb = runrc,
	}, {
		.name = "askfirst",
		.cb = askfirst,
		.multi = 1,
	}, {
		.name = "askconsole",
		.cb = askconsole,
		.multi = 1,
	}, {
		.name = "respawn",
		.cb = rcrespawn,
		.multi = 1,
	}
};

static int add_action(struct init_action *a, const char *name)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(handlers); i++)
		if (!strcmp(handlers[i].name, name)) {
			a->handler = &handlers[i];
			list_add_tail(&a->list, &actions);
			return 0;
		}
	ERROR("Unknown init handler %s\n", name);
	return -1;
}

void procd_inittab_run(const char *handler)
{
	struct init_action *a;

	list_for_each_entry(a, &actions, list)
		if (!strcmp(a->handler->name, handler)) {
			if (a->handler->multi) {
				a->handler->cb(a);
				continue;
			}
			a->handler->cb(a);
			break;
		}
}

void procd_inittab(void)
{
#define LINE_LEN	128
	FILE *fp = fopen(tab, "r");
	struct init_action *a;
	regex_t pat_inittab;
	regmatch_t matches[5];
	char *line;

	if (!fp) {
		ERROR("Failed to open %s\n", tab);
		return;
	}

	regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
	line = malloc(LINE_LEN);
	a = malloc(sizeof(struct init_action));
	memset(a, 0, sizeof(struct init_action));

	while (fgets(line, LINE_LEN, fp)) {
		char *tags[TAG_PROCESS + 1];
		char *tok;
		int i;
		int len = strlen(line);

		while (isspace(line[len - 1]))
			len--;
		line[len] = 0;

		if (*line == '#')
			continue;

		if (regexec(&pat_inittab, line, 5, matches, 0))
			continue;

		DEBUG(4, "Parsing inittab - %s", line);

		for (i = TAG_ID; i <= TAG_PROCESS; i++) {
			line[matches[i].rm_eo] = '\0';
			tags[i] = &line[matches[i + 1].rm_so];
		};

		tok = strtok(tags[TAG_PROCESS], " ");
		for (i = 0; i < (MAX_ARGS - i - 1) && tok; i++) {
			a->argv[i] = tok;
			tok = strtok(NULL, " ");
		}
		a->argv[i] = NULL;
		a->id = tags[TAG_ID];
		a->line = line;

		if (add_action(a, tags[TAG_ACTION]))
			continue;
		line = malloc(LINE_LEN);
		a = malloc(sizeof(struct init_action));
		memset(a, 0, sizeof(struct init_action));
	}

	fclose(fp);
	free(line);
	free(a);
	regfree(&pat_inittab);
}