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