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\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\n", proc->pid);
 124         uloop_timeout_set(&a->tout, a->respawn);
 125 }
 126
 127 static void respawn(struct uloop_timeout *tout)
 128 {
 129         struct init_action *a = container_of(tout, struct init_action, tout);
 130         fork_worker(a);
 131 }
 132
 133 static void rcdone(struct runqueue *q)
 134 {
 135         procd_state_next();
 136 }
 137
 138 static void runrc(struct init_action *a)
 139 {
 140         if (!a->argv[1] || !a->argv[2]) {
 141                 ERROR("valid format is rcS <S|K> <param>\n");
 142                 return;
 143         }
 144
 145         /* proceed even if no init or shutdown scripts run */
 146         if (rcS(a->argv[1], a->argv[2], rcdone))
 147                 rcdone(NULL);
 148 }
 149
 150 static void askfirst(struct init_action *a)
 151 {
 152         int i;
 153
 154         if (!dev_exist(a->id) || (console && !strcmp(console, a->id))) {
 155                 DEBUG(4, "Skipping %s\n", a->id);
 156                 return;
 157         }
 158
 159         a->tout.cb = respawn;
 160         for (i = MAX_ARGS - 1; i >= 1; i--)
 161                 a->argv[i] = a->argv[i - 1];
 162         a->argv[0] = ask;
 163         a->respawn = 500;
 164
 165         a->proc.cb = child_exit;
 166         fork_worker(a);
 167 }
 168
 169 static void askconsole(struct init_action *a)
 170 {
 171         char line[256], *tty, *split;
 172         int i;
 173
 174         tty = get_cmdline_val("console", line, sizeof(line));
 175         if (tty != NULL) {
 176                 split = strchr(tty, ',');
 177                 if (split != NULL)
 178                         *split = '\0';
 179
 180                 if (!dev_exist(tty)) {
 181                         DEBUG(4, "skipping %s\n", tty);
 182                         return;
 183                 }
 184
 185                 console = strdup(tty);
 186                 a->id = strdup(tty);
 187         }
 188         else {
 189                 console = NULL;
 190                 a->id = NULL;
 191         }
 192
 193         a->tout.cb = respawn;
 194         for (i = MAX_ARGS - 1; i >= 1; i--)
 195                 a->argv[i] = a->argv[i - 1];
 196         a->argv[0] = ask;
 197         a->respawn = 500;
 198
 199         a->proc.cb = child_exit;
 200         fork_worker(a);
 201 }
 202
 203 static void rcrespawn(struct init_action *a)
 204 {
 205         a->tout.cb = respawn;
 206         a->respawn = 500;
 207
 208         a->proc.cb = child_exit;
 209         fork_worker(a);
 210 }
 211
 212 static struct init_handler handlers[] = {
 213         {
 214                 .name = "sysinit",
 215                 .cb = runrc,
 216         }, {
 217                 .name = "shutdown",
 218                 .cb = runrc,
 219         }, {
 220                 .name = "askfirst",
 221                 .cb = askfirst,
 222                 .multi = 1,
 223         }, {
 224                 .name = "askconsole",
 225                 .cb = askconsole,
 226                 .multi = 1,
 227         }, {
 228                 .name = "respawn",
 229                 .cb = rcrespawn,
 230                 .multi = 1,
 231         }, {
 232                 .name = "askconsolelate",
 233                 .cb = askconsole,
 234                 .multi = 1,
 235         }, {
 236                 .name = "respawnlate",
 237                 .cb = rcrespawn,
 238                 .multi = 1,
 239         }
 240 };
 241
 242 static int add_action(struct init_action *a, const char *name)
 243 {
 244         int i;
 245
 246         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 247                 if (!strcmp(handlers[i].name, name)) {
 248                         a->handler = &handlers[i];
 249                         list_add_tail(&a->list, &actions);
 250                         return 0;
 251                 }
 252         ERROR("Unknown init handler %s\n", name);
 253         return -1;
 254 }
 255
 256 void procd_inittab_run(const char *handler)
 257 {
 258         struct init_action *a;
 259
 260         list_for_each_entry(a, &actions, list)
 261                 if (!strcmp(a->handler->name, handler)) {
 262                         if (a->handler->multi) {
 263                                 a->handler->cb(a);
 264                                 continue;
 265                         }
 266                         a->handler->cb(a);
 267                         break;
 268                 }
 269 }
 270
 271 void procd_inittab(void)
 272 {
 273 #define LINE_LEN        128
 274         FILE *fp = fopen(tab, "r");
 275         struct init_action *a;
 276         regex_t pat_inittab;
 277         regmatch_t matches[5];
 278         char *line;
 279
 280         if (!fp) {
 281                 ERROR("Failed to open %s\n", tab);
 282                 return;
 283         }
 284
 285         regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
 286         line = malloc(LINE_LEN);
 287         a = calloc(1, sizeof(struct init_action));
 288
 289         while (fgets(line, LINE_LEN, fp)) {
 290                 char *tags[TAG_PROCESS + 1];
 291                 char *tok;
 292                 int i;
 293                 int len = strlen(line);
 294
 295                 while (isspace(line[len - 1]))
 296                         len--;
 297                 line[len] = 0;
 298
 299                 if (*line == '#')
 300                         continue;
 301
 302                 if (regexec(&pat_inittab, line, 5, matches, 0))
 303                         continue;
 304
 305                 DEBUG(4, "Parsing inittab - %s\n", line);
 306
 307                 for (i = TAG_ID; i <= TAG_PROCESS; i++) {
 308                         line[matches[i].rm_eo] = '\0';
 309                         tags[i] = &line[matches[i + 1].rm_so];
 310                 };
 311
 312                 tok = strtok(tags[TAG_PROCESS], " ");
 313                 for (i = 0; i < (MAX_ARGS - 1) && tok; i++) {
 314                         a->argv[i] = tok;
 315                         tok = strtok(NULL, " ");
 316                 }
 317                 a->argv[i] = NULL;
 318                 a->id = tags[TAG_ID];
 319                 a->line = line;
 320
 321                 if (add_action(a, tags[TAG_ACTION]))
 322                         continue;
 323                 line = malloc(LINE_LEN);
 324                 a = calloc(1, sizeof(struct init_action));
 325         }
 326
 327         fclose(fp);
 328         free(line);
 329         free(a);
 330         regfree(&pat_inittab);
 331 }