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 int dev_open(const char *dev)
  68 {
  69         int fd = -1;
  70
  71         if (dev) {
  72                 chdir("/dev");
  73                 fd = open( dev, O_RDWR);
  74                 chdir("/");
  75         }
  76
  77         return fd;
  78 }
  79
  80 static int dev_exist(const char *dev)
  81 {
  82         int res;
  83
  84         res = dev_open(dev);
  85         if (res != -1) {
  86                 close(res);
  87         }
  88
  89         return (res != -1);
  90 }
  91
  92 static void fork_worker(struct init_action *a)
  93 {
  94         int fd;
  95         pid_t p;
  96
  97         a->proc.pid = fork();
  98         if (!a->proc.pid) {
  99                 p = setsid( );
 100                 fd = dev_open(a->id);
 101                 if (fd != -1)
 102                 {
 103                         dup2(fd, STDIN_FILENO);
 104                         dup2(fd, STDOUT_FILENO);
 105                         dup2(fd, STDERR_FILENO);
 106                         tcsetpgrp(fd, p);
 107                         close(fd);
 108                 }
 109                 execvp(a->argv[0], a->argv);
 110                 ERROR("Failed to execute %s\n", a->argv[0]);
 111                 exit(-1);
 112         }
 113
 114         if (a->proc.pid > 0) {
 115                 DEBUG(4, "Launched new %s action, pid=%d\n",
 116                                         a->handler->name,
 117                                         (int) a->proc.pid);
 118                 uloop_process_add(&a->proc);
 119         }
 120 }
 121
 122 static void child_exit(struct uloop_process *proc, int ret)
 123 {
 124         struct init_action *a = container_of(proc, struct init_action, proc);
 125
 126         DEBUG(4, "pid:%d\n", proc->pid);
 127         uloop_timeout_set(&a->tout, a->respawn);
 128 }
 129
 130 static void respawn(struct uloop_timeout *tout)
 131 {
 132         struct init_action *a = container_of(tout, struct init_action, tout);
 133         fork_worker(a);
 134 }
 135
 136 static void rcdone(struct runqueue *q)
 137 {
 138         procd_state_next();
 139 }
 140
 141 static void runrc(struct init_action *a)
 142 {
 143         if (!a->argv[1] || !a->argv[2]) {
 144                 ERROR("valid format is rcS <S|K> <param>\n");
 145                 return;
 146         }
 147         rcS(a->argv[1], a->argv[2], rcdone);
 148 }
 149
 150 static void askfirst(struct init_action *a)
 151 {
 152         int i;
 153
 154         if (!dev_exist(a->id) || (console && !strcmp(console, a->id))) {
 155                 DEBUG(4, "Skipping %s\n", a->id);
 156                 return;
 157         }
 158
 159         a->tout.cb = respawn;
 160         for (i = MAX_ARGS - 1; i >= 1; i--)
 161                 a->argv[i] = a->argv[i - 1];
 162         a->argv[0] = ask;
 163         a->respawn = 500;
 164
 165         a->proc.cb = child_exit;
 166         fork_worker(a);
 167 }
 168
 169 static void askconsole(struct init_action *a)
 170 {
 171         char line[256], *tty, *split;
 172         int i;
 173
 174         tty = get_cmdline_val("console", line, sizeof(line));
 175         split = strchr(tty, ',');
 176         if (split)
 177                 *split = '\0';
 178
 179         if (!dev_exist(tty)) {
 180                 DEBUG(4, "skipping %s\n", tty);
 181                 return;
 182         }
 183
 184         a->tout.cb = respawn;
 185         for (i = MAX_ARGS - 1; i >= 1; i--)
 186                 a->argv[i] = a->argv[i - 1];
 187         a->id = strdup(tty);
 188         a->argv[0] = ask;
 189         a->respawn = 500;
 190
 191         a->proc.cb = child_exit;
 192         fork_worker(a);
 193 }
 194
 195 static void rcrespawn(struct init_action *a)
 196 {
 197         a->tout.cb = respawn;
 198         a->respawn = 500;
 199
 200         a->proc.cb = child_exit;
 201         fork_worker(a);
 202 }
 203
 204 static struct init_handler handlers[] = {
 205         {
 206                 .name = "sysinit",
 207                 .cb = runrc,
 208         }, {
 209                 .name = "shutdown",
 210                 .cb = runrc,
 211         }, {
 212                 .name = "askfirst",
 213                 .cb = askfirst,
 214                 .multi = 1,
 215         }, {
 216                 .name = "askconsole",
 217                 .cb = askconsole,
 218                 .multi = 1,
 219         }, {
 220                 .name = "respawn",
 221                 .cb = rcrespawn,
 222                 .multi = 1,
 223         }
 224 };
 225
 226 static int add_action(struct init_action *a, const char *name)
 227 {
 228         int i;
 229
 230         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 231                 if (!strcmp(handlers[i].name, name)) {
 232                         a->handler = &handlers[i];
 233                         list_add_tail(&a->list, &actions);
 234                         return 0;
 235                 }
 236         ERROR("Unknown init handler %s\n", name);
 237         return -1;
 238 }
 239
 240 void procd_inittab_run(const char *handler)
 241 {
 242         struct init_action *a;
 243
 244         list_for_each_entry(a, &actions, list)
 245                 if (!strcmp(a->handler->name, handler)) {
 246                         if (a->handler->multi) {
 247                                 a->handler->cb(a);
 248                                 continue;
 249                         }
 250                         a->handler->cb(a);
 251                         break;
 252                 }
 253 }
 254
 255 void procd_inittab(void)
 256 {
 257 #define LINE_LEN        128
 258         FILE *fp = fopen(tab, "r");
 259         struct init_action *a;
 260         regex_t pat_inittab;
 261         regmatch_t matches[5];
 262         char *line;
 263
 264         if (!fp) {
 265                 ERROR("Failed to open %s\n", tab);
 266                 return;
 267         }
 268
 269         regcomp(&pat_inittab, "([a-zA-Z0-9]*):([a-zA-Z0-9]*):([a-zA-Z0-9]*):(.*)", REG_EXTENDED);
 270         line = malloc(LINE_LEN);
 271         a = malloc(sizeof(struct init_action));
 272         memset(a, 0, sizeof(struct init_action));
 273
 274         while (fgets(line, LINE_LEN, fp)) {
 275                 char *tags[TAG_PROCESS + 1];
 276                 char *tok;
 277                 int i;
 278                 int len = strlen(line);
 279
 280                 while (isspace(line[len - 1]))
 281                         len--;
 282                 line[len] = 0;
 283
 284                 if (*line == '#')
 285                         continue;
 286
 287                 if (regexec(&pat_inittab, line, 5, matches, 0))
 288                         continue;
 289
 290                 DEBUG(4, "Parsing inittab - %s", line);
 291
 292                 for (i = TAG_ID; i <= TAG_PROCESS; i++) {
 293                         line[matches[i].rm_eo] = '\0';
 294                         tags[i] = &line[matches[i + 1].rm_so];
 295                 };
 296
 297                 tok = strtok(tags[TAG_PROCESS], " ");
 298                 for (i = 0; i < (MAX_ARGS - 1) && tok; i++) {
 299                         a->argv[i] = tok;
 300                         tok = strtok(NULL, " ");
 301                 }
 302                 a->argv[i] = NULL;
 303                 a->id = tags[TAG_ID];
 304                 a->line = line;
 305
 306                 if (add_action(a, tags[TAG_ACTION]))
 307                         continue;
 308                 line = malloc(LINE_LEN);
 309                 a = malloc(sizeof(struct init_action));
 310                 memset(a, 0, sizeof(struct init_action));
 311         }
 312
 313         fclose(fp);
 314         free(line);
 315         free(a);
 316         regfree(&pat_inittab);
 317 }