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                 chdir("/dev");
  74                 fd = open( dev, O_RDWR);
  75                 chdir("/");
  76         }
  77
  78         return fd;
  79 }
  80
  81 static int dev_exist(const char *dev)
  82 {
  83         int res;
  84
  85         res = dev_open(dev);
  86         if (res != -1) {
  87                 close(res);
  88         }
  89
  90         return (res != -1);
  91 }
  92
  93 static void fork_worker(struct init_action *a)
  94 {
  95         int fd;
  96         pid_t p;
  97
  98         a->proc.pid = fork();
  99         if (!a->proc.pid) {
 100                 p = setsid();
 101
 102                 fd = dev_open(a->id);
 103                 if (fd != -1)
 104                 {
 105                         dup2(fd, STDIN_FILENO);
 106                         dup2(fd, STDOUT_FILENO);
 107                         dup2(fd, STDERR_FILENO);
 108                         if (fd > STDERR_FILENO)
 109                                 close(fd);
 110                 }
 111
 112                 ioctl(STDIN_FILENO, TIOCSCTTY, 1);
 113                 tcsetpgrp(STDIN_FILENO, p);
 114
 115                 execvp(a->argv[0], a->argv);
 116                 ERROR("Failed to execute %s\n", a->argv[0]);
 117                 exit(-1);
 118         }
 119
 120         if (a->proc.pid > 0) {
 121                 DEBUG(4, "Launched new %s action, pid=%d\n",
 122                                         a->handler->name,
 123                                         (int) a->proc.pid);
 124                 uloop_process_add(&a->proc);
 125         }
 126 }
 127
 128 static void child_exit(struct uloop_process *proc, int ret)
 129 {
 130         struct init_action *a = container_of(proc, struct init_action, proc);
 131
 132         DEBUG(4, "pid:%d\n", proc->pid);
 133         uloop_timeout_set(&a->tout, a->respawn);
 134 }
 135
 136 static void respawn(struct uloop_timeout *tout)
 137 {
 138         struct init_action *a = container_of(tout, struct init_action, tout);
 139         fork_worker(a);
 140 }
 141
 142 static void rcdone(struct runqueue *q)
 143 {
 144         procd_state_next();
 145 }
 146
 147 static void runrc(struct init_action *a)
 148 {
 149         if (!a->argv[1] || !a->argv[2]) {
 150                 ERROR("valid format is rcS <S|K> <param>\n");
 151                 return;
 152         }
 153         rcS(a->argv[1], a->argv[2], rcdone);
 154 }
 155
 156 static void askfirst(struct init_action *a)
 157 {
 158         int i;
 159
 160         if (!dev_exist(a->id) || (console && !strcmp(console, a->id))) {
 161                 DEBUG(4, "Skipping %s\n", a->id);
 162                 return;
 163         }
 164
 165         a->tout.cb = respawn;
 166         for (i = MAX_ARGS - 1; i >= 1; i--)
 167                 a->argv[i] = a->argv[i - 1];
 168         a->argv[0] = ask;
 169         a->respawn = 500;
 170
 171         a->proc.cb = child_exit;
 172         fork_worker(a);
 173 }
 174
 175 static void askconsole(struct init_action *a)
 176 {
 177         char line[256], *tty, *split;
 178         int i;
 179
 180         tty = get_cmdline_val("console", line, sizeof(line));
 181         if (tty != NULL) {
 182                 split = strchr(tty, ',');
 183                 if (split != NULL)
 184                         *split = '\0';
 185
 186                 if (!dev_exist(tty)) {
 187                         DEBUG(4, "skipping %s\n", tty);
 188                         return;
 189                 }
 190
 191                 console = strdup(tty);
 192                 a->id = strdup(tty);
 193         }
 194         else {
 195                 console = NULL;
 196                 a->id = NULL;
 197         }
 198
 199         a->tout.cb = respawn;
 200         for (i = MAX_ARGS - 1; i >= 1; i--)
 201                 a->argv[i] = a->argv[i - 1];
 202         a->argv[0] = ask;
 203         a->respawn = 500;
 204
 205         a->proc.cb = child_exit;
 206         fork_worker(a);
 207 }
 208
 209 static void rcrespawn(struct init_action *a)
 210 {
 211         a->tout.cb = respawn;
 212         a->respawn = 500;
 213
 214         a->proc.cb = child_exit;
 215         fork_worker(a);
 216 }
 217
 218 static struct init_handler handlers[] = {
 219         {
 220                 .name = "sysinit",
 221                 .cb = runrc,
 222         }, {
 223                 .name = "shutdown",
 224                 .cb = runrc,
 225         }, {
 226                 .name = "askfirst",
 227                 .cb = askfirst,
 228                 .multi = 1,
 229         }, {
 230                 .name = "askconsole",
 231                 .cb = askconsole,
 232                 .multi = 1,
 233         }, {
 234                 .name = "respawn",
 235                 .cb = rcrespawn,
 236                 .multi = 1,
 237         }
 238 };
 239
 240 static int add_action(struct init_action *a, const char *name)
 241 {
 242         int i;
 243
 244         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 245                 if (!strcmp(handlers[i].name, name)) {
 246                         a->handler = &handlers[i];
 247                         list_add_tail(&a->list, &actions);
 248                         return 0;
 249                 }
 250         ERROR("Unknown init handler %s\n", name);
 251         return -1;
 252 }
 253
 254 void procd_inittab_run(const char *handler)
 255 {
 256         struct init_action *a;
 257
 258         list_for_each_entry(a, &actions, list)
 259                 if (!strcmp(a->handler->name, handler)) {
 260                         if (a->handler->multi) {
 261                                 a->handler->cb(a);
 262                                 continue;
 263                         }
 264                         a->handler->cb(a);
 265                         break;
 266                 }
 267 }
 268
 269 void procd_inittab(void)
 270 {
 271 #define LINE_LEN        128
 272         FILE *fp = fopen(tab, "r");
 273         struct init_action *a;
 274         regex_t pat_inittab;
 275         regmatch_t matches[5];
 276         char *line;
 277
 278         if (!fp) {
 279                 ERROR("Failed to open %s\n", tab);
 280                 return;
 281         }
 282
 283         regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
 284         line = malloc(LINE_LEN);
 285         a = malloc(sizeof(struct init_action));
 286         memset(a, 0, sizeof(struct init_action));
 287
 288         while (fgets(line, LINE_LEN, fp)) {
 289                 char *tags[TAG_PROCESS + 1];
 290                 char *tok;
 291                 int i;
 292                 int len = strlen(line);
 293
 294                 while (isspace(line[len - 1]))
 295                         len--;
 296                 line[len] = 0;
 297
 298                 if (*line == '#')
 299                         continue;
 300
 301                 if (regexec(&pat_inittab, line, 5, matches, 0))
 302                         continue;
 303
 304                 DEBUG(4, "Parsing inittab - %s", line);
 305
 306                 for (i = TAG_ID; i <= TAG_PROCESS; i++) {
 307                         line[matches[i].rm_eo] = '\0';
 308                         tags[i] = &line[matches[i + 1].rm_so];
 309                 };
 310
 311                 tok = strtok(tags[TAG_PROCESS], " ");
 312                 for (i = 0; i < (MAX_ARGS - 1) && tok; i++) {
 313                         a->argv[i] = tok;
 314                         tok = strtok(NULL, " ");
 315                 }
 316                 a->argv[i] = NULL;
 317                 a->id = tags[TAG_ID];
 318                 a->line = line;
 319
 320                 if (add_action(a, tags[TAG_ACTION]))
 321                         continue;
 322                 line = malloc(LINE_LEN);
 323                 a = malloc(sizeof(struct init_action));
 324                 memset(a, 0, sizeof(struct init_action));
 325         }
 326
 327         fclose(fp);
 328         free(line);
 329         free(a);
 330         regfree(&pat_inittab);
 331 }