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 "procd.h"
  29 #include "rcS.h"
  30
  31 #define TAG_ID          0
  32 #define TAG_RUNLVL      1
  33 #define TAG_ACTION      2
  34 #define TAG_PROCESS     3
  35
  36 #define MAX_ARGS        8
  37
  38 struct init_action;
  39 const char *console;
  40
  41 struct init_handler {
  42         const char *name;
  43         void (*cb) (struct init_action *a);
  44         int multi;
  45 };
  46
  47 struct init_action {
  48         struct list_head list;
  49
  50         char *id;
  51         char *argv[MAX_ARGS];
  52         char *line;
  53
  54         struct init_handler *handler;
  55         struct uloop_process proc;
  56
  57         int respawn;
  58         struct uloop_timeout tout;
  59 };
  60
  61 static const char *tab = "/etc/inittab";
  62 static char *ask = "/sbin/askfirst";
  63
  64 static LIST_HEAD(actions);
  65
  66 static void fork_worker(struct init_action *a)
  67 {
  68         a->proc.pid = fork();
  69         if (!a->proc.pid) {
  70                 execvp(a->argv[0], a->argv);
  71                 ERROR("Failed to execute %s\n", a->argv[0]);
  72                 exit(-1);
  73         }
  74
  75         if (a->proc.pid > 0) {
  76                 DEBUG(4, "Launched new %s action, pid=%d\n",
  77                                         a->handler->name,
  78                                         (int) a->proc.pid);
  79                 uloop_process_add(&a->proc);
  80         }
  81 }
  82
  83 static void child_exit(struct uloop_process *proc, int ret)
  84 {
  85         struct init_action *a = container_of(proc, struct init_action, proc);
  86
  87         DEBUG(4, "pid:%d\n", proc->pid);
  88         uloop_timeout_set(&a->tout, a->respawn);
  89 }
  90
  91 static void respawn(struct uloop_timeout *tout)
  92 {
  93         struct init_action *a = container_of(tout, struct init_action, tout);
  94         fork_worker(a);
  95 }
  96
  97 static void rcdone(struct runqueue *q)
  98 {
  99         procd_state_next();
 100 }
 101
 102 static void runrc(struct init_action *a)
 103 {
 104         if (!a->argv[1] || !a->argv[2]) {
 105                 ERROR("valid format is rcS <S|K> <param>\n");
 106                 return;
 107         }
 108         rcS(a->argv[1], a->argv[2], rcdone);
 109 }
 110
 111 static void askfirst(struct init_action *a)
 112 {
 113         struct stat s;
 114         int i;
 115
 116         chdir("/dev");
 117         i = stat(a->id, &s);
 118         chdir("/");
 119         if (i || (console && !strcmp(console, a->id))) {
 120                 DEBUG(4, "Skipping %s\n", a->id);
 121                 return;
 122         }
 123
 124         a->tout.cb = respawn;
 125         for (i = MAX_ARGS - 2; i >= 2; i--)
 126                 a->argv[i] = a->argv[i - 2];
 127         a->argv[0] = ask;
 128         a->argv[1] = a->id;
 129         a->respawn = 500;
 130
 131         a->proc.cb = child_exit;
 132         fork_worker(a);
 133 }
 134
 135 static void askconsole(struct init_action *a)
 136 {
 137         struct stat s;
 138         char line[256], *tty;
 139         int i, r, fd = open("/proc/cmdline", O_RDONLY);
 140         regex_t pat_cmdline;
 141         regmatch_t matches[2];
 142
 143         if (fd < 0)
 144                 return;
 145
 146         r = read(fd, line, sizeof(line) - 1);
 147         line[r] = '\0';
 148         close(fd);
 149
 150         regcomp(&pat_cmdline, "console=([a-zA-Z0-9]*)", REG_EXTENDED);
 151         if (regexec(&pat_cmdline, line, 2, matches, 0))
 152                 goto err_out;
 153         line[matches[1].rm_eo] = '\0';
 154         tty = &line[matches[1].rm_so];
 155
 156         chdir("/dev");
 157         i = stat(tty, &s);
 158         chdir("/");
 159         if (i) {
 160                 DEBUG(4, "skipping %s\n", tty);
 161                 goto err_out;
 162         }
 163         console = strdup(tty);
 164
 165         a->tout.cb = respawn;
 166         for (i = MAX_ARGS - 2; i >= 2; i--)
 167                 a->argv[i] = a->argv[i - 2];
 168         a->argv[0] = ask;
 169         a->argv[1] = strdup(tty);
 170         a->respawn = 500;
 171
 172         a->proc.cb = child_exit;
 173         fork_worker(a);
 174
 175 err_out:
 176         regfree(&pat_cmdline);
 177 }
 178
 179 static void rcrespawn(struct init_action *a)
 180 {
 181         a->tout.cb = respawn;
 182         a->respawn = 500;
 183
 184         a->proc.cb = child_exit;
 185         fork_worker(a);
 186 }
 187
 188 static struct init_handler handlers[] = {
 189         {
 190                 .name = "sysinit",
 191                 .cb = runrc,
 192         }, {
 193                 .name = "shutdown",
 194                 .cb = runrc,
 195         }, {
 196                 .name = "askfirst",
 197                 .cb = askfirst,
 198                 .multi = 1,
 199         }, {
 200                 .name = "askconsole",
 201                 .cb = askconsole,
 202                 .multi = 1,
 203         }, {
 204                 .name = "respawn",
 205                 .cb = rcrespawn,
 206                 .multi = 1,
 207         }
 208 };
 209
 210 static int add_action(struct init_action *a, const char *name)
 211 {
 212         int i;
 213
 214         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 215                 if (!strcmp(handlers[i].name, name)) {
 216                         a->handler = &handlers[i];
 217                         list_add_tail(&a->list, &actions);
 218                         return 0;
 219                 }
 220         ERROR("Unknown init handler %s\n", name);
 221         return -1;
 222 }
 223
 224 void procd_inittab_run(const char *handler)
 225 {
 226         struct init_action *a;
 227
 228         list_for_each_entry(a, &actions, list)
 229                 if (!strcmp(a->handler->name, handler)) {
 230                         if (a->handler->multi) {
 231                                 a->handler->cb(a);
 232                                 continue;
 233                         }
 234                         a->handler->cb(a);
 235                         break;
 236                 }
 237 }
 238
 239 void procd_inittab(void)
 240 {
 241 #define LINE_LEN        128
 242         FILE *fp = fopen(tab, "r");
 243         struct init_action *a;
 244         regex_t pat_inittab;
 245         regmatch_t matches[5];
 246         char *line;
 247
 248         if (!fp) {
 249                 ERROR("Failed to open %s\n", tab);
 250                 return;
 251         }
 252
 253         regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
 254         line = malloc(LINE_LEN);
 255         a = malloc(sizeof(struct init_action));
 256         memset(a, 0, sizeof(struct init_action));
 257
 258         while (fgets(line, LINE_LEN, fp)) {
 259                 char *tags[TAG_PROCESS + 1];
 260                 char *tok;
 261                 int i;
 262                 int len = strlen(line);
 263
 264                 while (isspace(line[len - 1]))
 265                         len--;
 266                 line[len] = 0;
 267
 268                 if (*line == '#')
 269                         continue;
 270
 271                 if (regexec(&pat_inittab, line, 5, matches, 0))
 272                         continue;
 273
 274                 DEBUG(4, "Parsing inittab - %s", line);
 275
 276                 for (i = TAG_ID; i <= TAG_PROCESS; i++) {
 277                         line[matches[i].rm_eo] = '\0';
 278                         tags[i] = &line[matches[i + 1].rm_so];
 279                 };
 280
 281                 tok = strtok(tags[TAG_PROCESS], " ");
 282                 for (i = 0; i < (MAX_ARGS - i - 1) && tok; i++) {
 283                         a->argv[i] = tok;
 284                         tok = strtok(NULL, " ");
 285                 }
 286                 a->argv[i] = NULL;
 287                 a->id = tags[TAG_ID];
 288                 a->line = line;
 289
 290                 if (add_action(a, tags[TAG_ACTION]))
 291                         continue;
 292                 line = malloc(LINE_LEN);
 293                 a = malloc(sizeof(struct init_action));
 294                 memset(a, 0, sizeof(struct init_action));
 295         }
 296
 297         fclose(fp);
 298         free(line);
 299         free(a);
 300         regfree(&pat_inittab);
 301 }