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
  18 #include <fcntl.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <unistd.h>
  22 #include <regex.h>
  23 #include <ctype.h>
  24
  25 #include <libubox/utils.h>
  26 #include <libubox/list.h>
  27
  28 #include "utils/utils.h"
  29 #include "procd.h"
  30 #include "rcS.h"
  31
  32 #define TAG_ID          0
  33 #define TAG_RUNLVL      1
  34 #define TAG_ACTION      2
  35 #define TAG_PROCESS     3
  36
  37 #define MAX_ARGS        8
  38
  39 struct init_action;
  40 const char *console;
  41
  42 struct init_handler {
  43         const char *name;
  44         void (*cb) (struct init_action *a);
  45         int multi;
  46 };
  47
  48 struct init_action {
  49         struct list_head list;
  50
  51         char *id;
  52         char *argv[MAX_ARGS];
  53         char *line;
  54
  55         struct init_handler *handler;
  56         struct uloop_process proc;
  57
  58         int respawn;
  59         struct uloop_timeout tout;
  60 };
  61
  62 static const char *tab = "/etc/inittab";
  63 static char *ask = "/sbin/askfirst";
  64
  65 static LIST_HEAD(actions);
  66
  67 static void fork_worker(struct init_action *a)
  68 {
  69         a->proc.pid = fork();
  70         if (!a->proc.pid) {
  71                 execvp(a->argv[0], a->argv);
  72                 ERROR("Failed to execute %s\n", a->argv[0]);
  73                 exit(-1);
  74         }
  75
  76         if (a->proc.pid > 0) {
  77                 DEBUG(4, "Launched new %s action, pid=%d\n",
  78                                         a->handler->name,
  79                                         (int) a->proc.pid);
  80                 uloop_process_add(&a->proc);
  81         }
  82 }
  83
  84 static void child_exit(struct uloop_process *proc, int ret)
  85 {
  86         struct init_action *a = container_of(proc, struct init_action, proc);
  87
  88         DEBUG(4, "pid:%d\n", proc->pid);
  89         uloop_timeout_set(&a->tout, a->respawn);
  90 }
  91
  92 static void respawn(struct uloop_timeout *tout)
  93 {
  94         struct init_action *a = container_of(tout, struct init_action, tout);
  95         fork_worker(a);
  96 }
  97
  98 static void rcdone(struct runqueue *q)
  99 {
 100         procd_state_next();
 101 }
 102
 103 static void runrc(struct init_action *a)
 104 {
 105         if (!a->argv[1] || !a->argv[2]) {
 106                 ERROR("valid format is rcS <S|K> <param>\n");
 107                 return;
 108         }
 109         rcS(a->argv[1], a->argv[2], rcdone);
 110 }
 111
 112 static void askfirst(struct init_action *a)
 113 {
 114         struct stat s;
 115         int i;
 116
 117         chdir("/dev");
 118         i = stat(a->id, &s);
 119         chdir("/");
 120         if (i || (console && !strcmp(console, a->id))) {
 121                 DEBUG(4, "Skipping %s\n", a->id);
 122                 return;
 123         }
 124
 125         a->tout.cb = respawn;
 126         for (i = MAX_ARGS - 2; i >= 2; i--)
 127                 a->argv[i] = a->argv[i - 2];
 128         a->argv[0] = ask;
 129         a->argv[1] = a->id;
 130         a->respawn = 500;
 131
 132         a->proc.cb = child_exit;
 133         fork_worker(a);
 134 }
 135
 136 static void askconsole(struct init_action *a)
 137 {
 138         struct stat s;
 139         char line[256], *tty, *split;
 140         int i;
 141
 142         tty = get_cmdline_val("console", line, sizeof(line));
 143         split=strchr(tty, ',');
 144         if (split != NULL)
 145                 split = '\0';
 146
 147         chdir("/dev");
 148         i = stat(tty, &s);
 149         chdir("/");
 150         if (i) {
 151                 DEBUG(4, "skipping %s\n", tty);
 152                 return;
 153         }
 154         console = strdup(tty);
 155
 156         a->tout.cb = respawn;
 157         for (i = MAX_ARGS - 2; i >= 2; i--)
 158                 a->argv[i] = a->argv[i - 2];
 159         a->argv[0] = ask;
 160         a->argv[1] = strdup(tty);
 161         a->respawn = 500;
 162
 163         a->proc.cb = child_exit;
 164         fork_worker(a);
 165 }
 166
 167 static void rcrespawn(struct init_action *a)
 168 {
 169         a->tout.cb = respawn;
 170         a->respawn = 500;
 171
 172         a->proc.cb = child_exit;
 173         fork_worker(a);
 174 }
 175
 176 static struct init_handler handlers[] = {
 177         {
 178                 .name = "sysinit",
 179                 .cb = runrc,
 180         }, {
 181                 .name = "shutdown",
 182                 .cb = runrc,
 183         }, {
 184                 .name = "askfirst",
 185                 .cb = askfirst,
 186                 .multi = 1,
 187         }, {
 188                 .name = "askconsole",
 189                 .cb = askconsole,
 190                 .multi = 1,
 191         }, {
 192                 .name = "respawn",
 193                 .cb = rcrespawn,
 194                 .multi = 1,
 195         }
 196 };
 197
 198 static int add_action(struct init_action *a, const char *name)
 199 {
 200         int i;
 201
 202         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 203                 if (!strcmp(handlers[i].name, name)) {
 204                         a->handler = &handlers[i];
 205                         list_add_tail(&a->list, &actions);
 206                         return 0;
 207                 }
 208         ERROR("Unknown init handler %s\n", name);
 209         return -1;
 210 }
 211
 212 void procd_inittab_run(const char *handler)
 213 {
 214         struct init_action *a;
 215
 216         list_for_each_entry(a, &actions, list)
 217                 if (!strcmp(a->handler->name, handler)) {
 218                         if (a->handler->multi) {
 219                                 a->handler->cb(a);
 220                                 continue;
 221                         }
 222                         a->handler->cb(a);
 223                         break;
 224                 }
 225 }
 226
 227 void procd_inittab(void)
 228 {
 229 #define LINE_LEN        128
 230         FILE *fp = fopen(tab, "r");
 231         struct init_action *a;
 232         regex_t pat_inittab;
 233         regmatch_t matches[5];
 234         char *line;
 235
 236         if (!fp) {
 237                 ERROR("Failed to open %s\n", tab);
 238                 return;
 239         }
 240
 241         regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
 242         line = malloc(LINE_LEN);
 243         a = malloc(sizeof(struct init_action));
 244         memset(a, 0, sizeof(struct init_action));
 245
 246         while (fgets(line, LINE_LEN, fp)) {
 247                 char *tags[TAG_PROCESS + 1];
 248                 char *tok;
 249                 int i;
 250                 int len = strlen(line);
 251
 252                 while (isspace(line[len - 1]))
 253                         len--;
 254                 line[len] = 0;
 255
 256                 if (*line == '#')
 257                         continue;
 258
 259                 if (regexec(&pat_inittab, line, 5, matches, 0))
 260                         continue;
 261
 262                 DEBUG(4, "Parsing inittab - %s", line);
 263
 264                 for (i = TAG_ID; i <= TAG_PROCESS; i++) {
 265                         line[matches[i].rm_eo] = '\0';
 266                         tags[i] = &line[matches[i + 1].rm_so];
 267                 };
 268
 269                 tok = strtok(tags[TAG_PROCESS], " ");
 270                 for (i = 0; i < (MAX_ARGS - 1) && tok; i++) {
 271                         a->argv[i] = tok;
 272                         tok = strtok(NULL, " ");
 273                 }
 274                 a->argv[i] = NULL;
 275                 a->id = tags[TAG_ID];
 276                 a->line = line;
 277
 278                 if (add_action(a, tags[TAG_ACTION]))
 279                         continue;
 280                 line = malloc(LINE_LEN);
 281                 a = malloc(sizeof(struct init_action));
 282                 memset(a, 0, sizeof(struct init_action));
 283         }
 284
 285         fclose(fp);
 286         free(line);
 287         free(a);
 288         regfree(&pat_inittab);
 289 }