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                         a->handler->cb(a);
 280                         if (!a->handler->multi)
 281                                 break;
 282                 }
 283 }
 284
 285 void procd_inittab(void)
 286 {
 287 #define LINE_LEN        128
 288         FILE *fp = fopen(tab, "r");
 289         struct init_action *a;
 290         regex_t pat_inittab;
 291         regmatch_t matches[5];
 292         char *line;
 293
 294         if (!fp) {
 295                 ERROR("Failed to open %s: %m\n", tab);
 296                 return;
 297         }
 298
 299         regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
 300         line = malloc(LINE_LEN);
 301         a = calloc(1, sizeof(struct init_action));
 302
 303         while (fgets(line, LINE_LEN, fp)) {
 304                 char *tags[TAG_PROCESS + 1];
 305                 char *tok;
 306                 int i;
 307                 int len = strlen(line);
 308
 309                 while (isspace(line[len - 1]))
 310                         len--;
 311                 line[len] = 0;
 312
 313                 if (*line == '#')
 314                         continue;
 315
 316                 if (regexec(&pat_inittab, line, 5, matches, 0))
 317                         continue;
 318
 319                 DEBUG(4, "Parsing inittab - %s\n", line);
 320
 321                 for (i = TAG_ID; i <= TAG_PROCESS; i++) {
 322                         line[matches[i].rm_eo] = '\0';
 323                         tags[i] = &line[matches[i + 1].rm_so];
 324                 };
 325
 326                 tok = strtok(tags[TAG_PROCESS], " ");
 327                 for (i = 0; i < (MAX_ARGS - 1) && tok; i++) {
 328                         a->argv[i] = tok;
 329                         tok = strtok(NULL, " ");
 330                 }
 331                 a->argv[i] = NULL;
 332                 a->id = tags[TAG_ID];
 333                 a->line = line;
 334
 335                 if (add_action(a, tags[TAG_ACTION]))
 336                         continue;
 337                 line = malloc(LINE_LEN);
 338                 a = calloc(1, sizeof(struct init_action));
 339         }
 340
 341         fclose(fp);
 342         free(line);
 343         free(a);
 344         regfree(&pat_inittab);
 345 }