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