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         int fd;
  97         pid_t p;
  98
  99         a->proc.pid = fork();
 100         if (!a->proc.pid) {
 101                 p = setsid();
 102
 103                 fd = dev_open(a->id);
 104                 if (fd != -1)
 105                 {
 106                         dup2(fd, STDIN_FILENO);
 107                         dup2(fd, STDOUT_FILENO);
 108                         dup2(fd, STDERR_FILENO);
 109                         if (fd > STDERR_FILENO)
 110                                 close(fd);
 111                 }
 112
 113                 ioctl(STDIN_FILENO, TIOCSCTTY, 1);
 114                 tcsetpgrp(STDIN_FILENO, p);
 115
 116                 execvp(a->argv[0], a->argv);
 117                 ERROR("Failed to execute %s\n", a->argv[0]);
 118                 exit(-1);
 119         }
 120
 121         if (a->proc.pid > 0) {
 122                 DEBUG(4, "Launched new %s action, pid=%d\n",
 123                                         a->handler->name,
 124                                         (int) a->proc.pid);
 125                 uloop_process_add(&a->proc);
 126         }
 127 }
 128
 129 static void child_exit(struct uloop_process *proc, int ret)
 130 {
 131         struct init_action *a = container_of(proc, struct init_action, proc);
 132
 133         DEBUG(4, "pid:%d\n", proc->pid);
 134         uloop_timeout_set(&a->tout, a->respawn);
 135 }
 136
 137 static void respawn(struct uloop_timeout *tout)
 138 {
 139         struct init_action *a = container_of(tout, struct init_action, tout);
 140         fork_worker(a);
 141 }
 142
 143 static void rcdone(struct runqueue *q)
 144 {
 145         procd_state_next();
 146 }
 147
 148 static void runrc(struct init_action *a)
 149 {
 150         if (!a->argv[1] || !a->argv[2]) {
 151                 ERROR("valid format is rcS <S|K> <param>\n");
 152                 return;
 153         }
 154         rcS(a->argv[1], a->argv[2], rcdone);
 155 }
 156
 157 static void askfirst(struct init_action *a)
 158 {
 159         int i;
 160
 161         if (!dev_exist(a->id) || (console && !strcmp(console, a->id))) {
 162                 DEBUG(4, "Skipping %s\n", a->id);
 163                 return;
 164         }
 165
 166         a->tout.cb = respawn;
 167         for (i = MAX_ARGS - 1; i >= 1; i--)
 168                 a->argv[i] = a->argv[i - 1];
 169         a->argv[0] = ask;
 170         a->respawn = 500;
 171
 172         a->proc.cb = child_exit;
 173         fork_worker(a);
 174 }
 175
 176 static void askconsole(struct init_action *a)
 177 {
 178         char line[256], *tty, *split;
 179         int i;
 180
 181         tty = get_cmdline_val("console", line, sizeof(line));
 182         if (tty != NULL) {
 183                 split = strchr(tty, ',');
 184                 if (split != NULL)
 185                         *split = '\0';
 186
 187                 if (!dev_exist(tty)) {
 188                         DEBUG(4, "skipping %s\n", tty);
 189                         return;
 190                 }
 191
 192                 console = strdup(tty);
 193                 a->id = strdup(tty);
 194         }
 195         else {
 196                 console = NULL;
 197                 a->id = NULL;
 198         }
 199
 200         a->tout.cb = respawn;
 201         for (i = MAX_ARGS - 1; i >= 1; i--)
 202                 a->argv[i] = a->argv[i - 1];
 203         a->argv[0] = ask;
 204         a->respawn = 500;
 205
 206         a->proc.cb = child_exit;
 207         fork_worker(a);
 208 }
 209
 210 static void rcrespawn(struct init_action *a)
 211 {
 212         a->tout.cb = respawn;
 213         a->respawn = 500;
 214
 215         a->proc.cb = child_exit;
 216         fork_worker(a);
 217 }
 218
 219 static struct init_handler handlers[] = {
 220         {
 221                 .name = "sysinit",
 222                 .cb = runrc,
 223         }, {
 224                 .name = "shutdown",
 225                 .cb = runrc,
 226         }, {
 227                 .name = "askfirst",
 228                 .cb = askfirst,
 229                 .multi = 1,
 230         }, {
 231                 .name = "askconsole",
 232                 .cb = askconsole,
 233                 .multi = 1,
 234         }, {
 235                 .name = "respawn",
 236                 .cb = rcrespawn,
 237                 .multi = 1,
 238         }
 239 };
 240
 241 static int add_action(struct init_action *a, const char *name)
 242 {
 243         int i;
 244
 245         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 246                 if (!strcmp(handlers[i].name, name)) {
 247                         a->handler = &handlers[i];
 248                         list_add_tail(&a->list, &actions);
 249                         return 0;
 250                 }
 251         ERROR("Unknown init handler %s\n", name);
 252         return -1;
 253 }
 254
 255 void procd_inittab_run(const char *handler)
 256 {
 257         struct init_action *a;
 258
 259         list_for_each_entry(a, &actions, list)
 260                 if (!strcmp(a->handler->name, handler)) {
 261                         if (a->handler->multi) {
 262                                 a->handler->cb(a);
 263                                 continue;
 264                         }
 265                         a->handler->cb(a);
 266                         break;
 267                 }
 268 }
 269
 270 void procd_inittab(void)
 271 {
 272 #define LINE_LEN        128
 273         FILE *fp = fopen(tab, "r");
 274         struct init_action *a;
 275         regex_t pat_inittab;
 276         regmatch_t matches[5];
 277         char *line;
 278
 279         if (!fp) {
 280                 ERROR("Failed to open %s\n", tab);
 281                 return;
 282         }
 283
 284         regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
 285         line = malloc(LINE_LEN);
 286         a = malloc(sizeof(struct init_action));
 287         memset(a, 0, 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", 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 = malloc(sizeof(struct init_action));
 325                 memset(a, 0, sizeof(struct init_action));
 326         }
 327
 328         fclose(fp);
 329         free(line);
 330         free(a);
 331         regfree(&pat_inittab);
 332 }