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 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <sys/ioctl.h>
  18
  19 #include <fcntl.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <unistd.h>
  23 #include <regex.h>
  24 #include <ctype.h>
  25
  26 #include <libubox/utils.h>
  27 #include <libubox/list.h>
  28
  29 #include "utils/utils.h"
  30 #include "procd.h"
  31 #include "rcS.h"
  32
  33 #define TAG_ID          0
  34 #define TAG_RUNLVL      1
  35 #define TAG_ACTION      2
  36 #define TAG_PROCESS     3
  37
  38 #define MAX_ARGS        8
  39
  40 struct init_action;
  41 char *console = NULL;
  42
  43 struct init_handler {
  44         const char *name;
  45         void (*cb) (struct init_action *a);
  46         int multi;
  47 };
  48
  49 struct init_action {
  50         struct list_head list;
  51
  52         char *id;
  53         char *argv[MAX_ARGS];
  54         char *line;
  55
  56         struct init_handler *handler;
  57         struct uloop_process proc;
  58
  59         int respawn;
  60         struct uloop_timeout tout;
  61 };
  62
  63 static const char *tab = "/etc/inittab";
  64 static char *ask = "/sbin/askfirst";
  65
  66 static LIST_HEAD(actions);
  67
  68 static int dev_open(const char *dev)
  69 {
  70         int fd = -1;
  71
  72         if (dev) {
  73                 if (chdir("/dev"))
  74                         ERROR("failed to change dir to /dev\n");
  75                 fd = open(dev, O_RDWR);
  76                 if (chdir("/"))
  77                         ERROR("failed to change dir to /\n");
  78         }
  79
  80         return fd;
  81 }
  82
  83 static int dev_exist(const char *dev)
  84 {
  85         int res;
  86
  87         res = dev_open(dev);
  88         if (res != -1)
  89                 close(res);
  90
  91         return (res != -1);
  92 }
  93
  94 static void fork_worker(struct init_action *a)
  95 {
  96         pid_t p;
  97
  98         a->proc.pid = fork();
  99         if (!a->proc.pid) {
 100                 p = setsid();
 101
 102                 if (patch_stdio(a->id))
 103                         ERROR("Failed to setup i/o redirection\n");
 104
 105                 ioctl(STDIN_FILENO, TIOCSCTTY, 1);
 106                 tcsetpgrp(STDIN_FILENO, p);
 107
 108                 execvp(a->argv[0], a->argv);
 109                 ERROR("Failed to execute %s\n", a->argv[0]);
 110                 exit(-1);
 111         }
 112
 113         if (a->proc.pid > 0) {
 114                 DEBUG(4, "Launched new %s action, pid=%d\n",
 115                                         a->handler->name,
 116                                         (int) a->proc.pid);
 117                 uloop_process_add(&a->proc);
 118         }
 119 }
 120
 121 static void child_exit(struct uloop_process *proc, int ret)
 122 {
 123         struct init_action *a = container_of(proc, struct init_action, proc);
 124
 125         DEBUG(4, "pid:%d\n", proc->pid);
 126         uloop_timeout_set(&a->tout, a->respawn);
 127 }
 128
 129 static void respawn(struct uloop_timeout *tout)
 130 {
 131         struct init_action *a = container_of(tout, struct init_action, tout);
 132         fork_worker(a);
 133 }
 134
 135 static void rcdone(struct runqueue *q)
 136 {
 137         procd_state_next();
 138 }
 139
 140 static void runrc(struct init_action *a)
 141 {
 142         if (!a->argv[1] || !a->argv[2]) {
 143                 ERROR("valid format is rcS <S|K> <param>\n");
 144                 return;
 145         }
 146
 147         /* proceed even if no init or shutdown scripts run */
 148         if (rcS(a->argv[1], a->argv[2], rcdone))
 149                 rcdone(NULL);
 150 }
 151
 152 static void askfirst(struct init_action *a)
 153 {
 154         int i;
 155
 156         if (!dev_exist(a->id) || (console && !strcmp(console, a->id))) {
 157                 DEBUG(4, "Skipping %s\n", a->id);
 158                 return;
 159         }
 160
 161         a->tout.cb = respawn;
 162         for (i = MAX_ARGS - 1; i >= 1; i--)
 163                 a->argv[i] = a->argv[i - 1];
 164         a->argv[0] = ask;
 165         a->respawn = 500;
 166
 167         a->proc.cb = child_exit;
 168         fork_worker(a);
 169 }
 170
 171 static void askconsole(struct init_action *a)
 172 {
 173         char line[256], *tty, *split;
 174         int i;
 175
 176         tty = get_cmdline_val("console", line, sizeof(line));
 177         if (tty != NULL) {
 178                 split = strchr(tty, ',');
 179                 if (split != NULL)
 180                         *split = '\0';
 181
 182                 if (!dev_exist(tty)) {
 183                         DEBUG(4, "skipping %s\n", tty);
 184                         return;
 185                 }
 186
 187                 console = strdup(tty);
 188                 a->id = strdup(tty);
 189         }
 190         else {
 191                 console = NULL;
 192                 a->id = NULL;
 193         }
 194
 195         a->tout.cb = respawn;
 196         for (i = MAX_ARGS - 1; i >= 1; i--)
 197                 a->argv[i] = a->argv[i - 1];
 198         a->argv[0] = ask;
 199         a->respawn = 500;
 200
 201         a->proc.cb = child_exit;
 202         fork_worker(a);
 203 }
 204
 205 static void rcrespawn(struct init_action *a)
 206 {
 207         a->tout.cb = respawn;
 208         a->respawn = 500;
 209
 210         a->proc.cb = child_exit;
 211         fork_worker(a);
 212 }
 213
 214 static struct init_handler handlers[] = {
 215         {
 216                 .name = "sysinit",
 217                 .cb = runrc,
 218         }, {
 219                 .name = "shutdown",
 220                 .cb = runrc,
 221         }, {
 222                 .name = "askfirst",
 223                 .cb = askfirst,
 224                 .multi = 1,
 225         }, {
 226                 .name = "askconsole",
 227                 .cb = askconsole,
 228                 .multi = 1,
 229         }, {
 230                 .name = "respawn",
 231                 .cb = rcrespawn,
 232                 .multi = 1,
 233         }
 234 };
 235
 236 static int add_action(struct init_action *a, const char *name)
 237 {
 238         int i;
 239
 240         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 241                 if (!strcmp(handlers[i].name, name)) {
 242                         a->handler = &handlers[i];
 243                         list_add_tail(&a->list, &actions);
 244                         return 0;
 245                 }
 246         ERROR("Unknown init handler %s\n", name);
 247         return -1;
 248 }
 249
 250 void procd_inittab_run(const char *handler)
 251 {
 252         struct init_action *a;
 253
 254         list_for_each_entry(a, &actions, list)
 255                 if (!strcmp(a->handler->name, handler)) {
 256                         if (a->handler->multi) {
 257                                 a->handler->cb(a);
 258                                 continue;
 259                         }
 260                         a->handler->cb(a);
 261                         break;
 262                 }
 263 }
 264
 265 void procd_inittab(void)
 266 {
 267 #define LINE_LEN        128
 268         FILE *fp = fopen(tab, "r");
 269         struct init_action *a;
 270         regex_t pat_inittab;
 271         regmatch_t matches[5];
 272         char *line;
 273
 274         if (!fp) {
 275                 ERROR("Failed to open %s\n", tab);
 276                 return;
 277         }
 278
 279         regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
 280         line = malloc(LINE_LEN);
 281         a = malloc(sizeof(struct init_action));
 282         memset(a, 0, sizeof(struct init_action));
 283
 284         while (fgets(line, LINE_LEN, fp)) {
 285                 char *tags[TAG_PROCESS + 1];
 286                 char *tok;
 287                 int i;
 288                 int len = strlen(line);
 289
 290                 while (isspace(line[len - 1]))
 291                         len--;
 292                 line[len] = 0;
 293
 294                 if (*line == '#')
 295                         continue;
 296
 297                 if (regexec(&pat_inittab, line, 5, matches, 0))
 298                         continue;
 299
 300                 DEBUG(4, "Parsing inittab - %s", line);
 301
 302                 for (i = TAG_ID; i <= TAG_PROCESS; i++) {
 303                         line[matches[i].rm_eo] = '\0';
 304                         tags[i] = &line[matches[i + 1].rm_so];
 305                 };
 306
 307                 tok = strtok(tags[TAG_PROCESS], " ");
 308                 for (i = 0; i < (MAX_ARGS - 1) && tok; i++) {
 309                         a->argv[i] = tok;
 310                         tok = strtok(NULL, " ");
 311                 }
 312                 a->argv[i] = NULL;
 313                 a->id = tags[TAG_ID];
 314                 a->line = line;
 315
 316                 if (add_action(a, tags[TAG_ACTION]))
 317                         continue;
 318                 line = malloc(LINE_LEN);
 319                 a = malloc(sizeof(struct init_action));
 320                 memset(a, 0, sizeof(struct init_action));
 321         }
 322
 323         fclose(fp);
 324         free(line);
 325         free(a);
 326         regfree(&pat_inittab);
 327 }