udevstart.c

   1 /*
   2  * udevstart.c
   3  *
   4  * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
   5  *
   6  * Quick and dirty way to populate a /dev with udev if your system
   7  * does not have access to a shell.  Based originally on a patch to udev
   8  * from Harald Hoyer <harald@redhat.com>
   9  *
  10  *      This program is free software; you can redistribute it and/or modify it
  11  *      under the terms of the GNU General Public License as published by the
  12  *      Free Software Foundation version 2 of the License.
  13  *
  14  *      This program is distributed in the hope that it will be useful, but
  15  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *      General Public License for more details.
  18  *
  19  *      You should have received a copy of the GNU General Public License along
  20  *      with this program; if not, write to the Free Software Foundation, Inc.,
  21  *      675 Mass Ave, Cambridge, MA 02139, USA.
  22  *
  23  */
  24
  25 #include <stdlib.h>
  26 #include <stddef.h>
  27 #include <string.h>
  28 #include <stdio.h>
  29 #include <unistd.h>
  30 #include <errno.h>
  31 #include <ctype.h>
  32 #include <dirent.h>
  33 #include <signal.h>
  34 #include <sys/wait.h>
  35 #include <sys/stat.h>
  36 #include <sys/types.h>
  37
  38 #include "libsysfs/sysfs/libsysfs.h"
  39 #include "udev_libc_wrapper.h"
  40 #include "udev.h"
  41 #include "udev_version.h"
  42 #include "logging.h"
  43 #include "udev_rules.h"
  44 #include "udev_utils.h"
  45 #include "list.h"
  46
  47 #ifdef USE_LOG
  48 void log_message(int priority, const char *format, ...)
  49 {
  50         va_list args;
  51
  52         if (priority > udev_log_priority)
  53                 return;
  54
  55         va_start(args, format);
  56         vsyslog(priority, format, args);
  57         va_end(args);
  58 }
  59 #endif
  60
  61 struct device {
  62         struct list_head node;
  63         char path[PATH_SIZE];
  64         char subsys[NAME_SIZE];
  65 };
  66
  67 /* sort files in lexical order */
  68 static int device_list_insert(const char *path, char *subsystem, struct list_head *device_list)
  69 {
  70         struct device *loop_device;
  71         struct device *new_device;
  72
  73         dbg("insert: '%s'\n", path);
  74
  75         list_for_each_entry(loop_device, device_list, node) {
  76                 if (strcmp(loop_device->path, path) > 0) {
  77                         break;
  78                 }
  79         }
  80
  81         new_device = malloc(sizeof(struct device));
  82         if (new_device == NULL) {
  83                 dbg("error malloc");
  84                 return -ENOMEM;
  85         }
  86
  87         strlcpy(new_device->path, path, sizeof(new_device->path));
  88         strlcpy(new_device->subsys, subsystem, sizeof(new_device->subsys));
  89         list_add_tail(&new_device->node, &loop_device->node);
  90         dbg("add '%s' from subsys '%s'", new_device->path, new_device->subsys);
  91         return 0;
  92 }
  93
  94 /* list of devices that we should run last due to any one of a number of reasons */
  95 static char *last_list[] = {
  96         "/block/dm",    /* on here because dm wants to have the block devices around before it */
  97         NULL,
  98 };
  99
 100 /* list of devices that we should run first due to any one of a number of reasons */
 101 static char *first_list[] = {
 102         "/class/mem",   /* people tend to like their memory devices around first... */
 103         NULL,
 104 };
 105
 106 static int add_device(const char *path, const char *subsystem)
 107 {
 108         struct udevice udev;
 109         struct sysfs_class_device *class_dev;
 110         const char *devpath;
 111
 112         devpath = &path[strlen(sysfs_path)];
 113
 114         /* set environment for callouts and dev.d/ */
 115         setenv("DEVPATH", devpath, 1);
 116         setenv("SUBSYSTEM", subsystem, 1);
 117
 118         dbg("exec: '%s' (%s)\n", devpath, path);
 119
 120         class_dev = sysfs_open_class_device_path(path);
 121         if (class_dev == NULL) {
 122                 dbg ("sysfs_open_class_device_path failed");
 123                 return -ENODEV;
 124         }
 125
 126         udev_init_device(&udev, devpath, subsystem, "add");
 127         udev_add_device(&udev, class_dev);
 128
 129         if (udev.devname[0] != '\0')
 130                 setenv("DEVNAME", udev.devname, 1);
 131
 132         if (udev_run && !list_empty(&udev.run_list)) {
 133                 struct name_entry *name_loop;
 134
 135                 dbg("executing run list");
 136                 list_for_each_entry(name_loop, &udev.run_list, node)
 137                         execute_command(name_loop->name, udev.subsystem);
 138         }
 139
 140         /* run dev.d/ scripts if we created a node or changed a netif name */
 141         if (udev_dev_d && udev.devname[0] != '\0')
 142                 udev_multiplex_directory(&udev, DEVD_DIR, DEVD_SUFFIX);
 143
 144         sysfs_close_class_device(class_dev);
 145         udev_cleanup_device(&udev);
 146
 147         return 0;
 148 }
 149
 150 static void exec_list(struct list_head *device_list)
 151 {
 152         struct device *loop_device;
 153         struct device *tmp_device;
 154         int i;
 155
 156         /* handle the "first" type devices first */
 157         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 158                 for (i = 0; first_list[i] != NULL; i++) {
 159                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 160                                 add_device(loop_device->path, loop_device->subsys);
 161                                 list_del(&loop_device->node);
 162                                 free(loop_device);
 163                                 break;
 164                         }
 165                 }
 166         }
 167
 168         /* handle the devices we are allowed to, excluding the "last" type devices */
 169         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 170                 int found = 0;
 171                 for (i = 0; last_list[i] != NULL; i++) {
 172                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 173                                 found = 1;
 174                                 break;
 175                         }
 176                 }
 177                 if (found)
 178                         continue;
 179
 180                 add_device(loop_device->path, loop_device->subsys);
 181                 list_del(&loop_device->node);
 182                 free(loop_device);
 183         }
 184
 185         /* handle the rest of the devices left over, if any */
 186         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 187                 add_device(loop_device->path, loop_device->subsys);
 188                 list_del(&loop_device->node);
 189                 free(loop_device);
 190         }
 191 }
 192
 193 static int has_devt(const char *directory)
 194 {
 195         char filename[PATH_SIZE];
 196         struct stat statbuf;
 197
 198         snprintf(filename, sizeof(filename), "%s/dev", directory);
 199         filename[sizeof(filename)-1] = '\0';
 200
 201         if (stat(filename, &statbuf) == 0)
 202                 return 1;
 203
 204         return 0;
 205 }
 206
 207 static void udev_scan_block(void)
 208 {
 209         char base[PATH_SIZE];
 210         DIR *dir;
 211         struct dirent *dent;
 212         LIST_HEAD(device_list);
 213
 214         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 215         base[sizeof(base)-1] = '\0';
 216
 217         dir = opendir(base);
 218         if (dir != NULL) {
 219                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 220                         char dirname[PATH_SIZE];
 221                         DIR *dir2;
 222                         struct dirent *dent2;
 223
 224                         if (dent->d_name[0] == '.')
 225                                 continue;
 226
 227                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 228                         dirname[sizeof(dirname)-1] = '\0';
 229                         if (has_devt(dirname))
 230                                 device_list_insert(dirname, "block", &device_list);
 231                         else
 232                                 continue;
 233
 234                         /* look for partitions */
 235                         dir2 = opendir(dirname);
 236                         if (dir2 != NULL) {
 237                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 238                                         char dirname2[PATH_SIZE];
 239
 240                                         if (dent2->d_name[0] == '.')
 241                                                 continue;
 242
 243                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 244                                         dirname2[sizeof(dirname2)-1] = '\0';
 245
 246                                         if (has_devt(dirname2))
 247                                                 device_list_insert(dirname2, "block", &device_list);
 248                                 }
 249                                 closedir(dir2);
 250                         }
 251                 }
 252                 closedir(dir);
 253         }
 254         exec_list(&device_list);
 255 }
 256
 257 static void udev_scan_class(void)
 258 {
 259         char base[PATH_SIZE];
 260         DIR *dir;
 261         struct dirent *dent;
 262         LIST_HEAD(device_list);
 263
 264         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 265         base[sizeof(base)-1] = '\0';
 266
 267         dir = opendir(base);
 268         if (dir != NULL) {
 269                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 270                         char dirname[PATH_SIZE];
 271                         DIR *dir2;
 272                         struct dirent *dent2;
 273
 274                         if (dent->d_name[0] == '.')
 275                                 continue;
 276
 277                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 278                         dirname[sizeof(dirname)-1] = '\0';
 279
 280                         dir2 = opendir(dirname);
 281                         if (dir2 != NULL) {
 282                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 283                                         char dirname2[PATH_SIZE];
 284
 285                                         if (dent2->d_name[0] == '.')
 286                                                 continue;
 287
 288                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 289                                         dirname2[sizeof(dirname2)-1] = '\0';
 290
 291                                         /* pass the net class as it is */
 292                                         if (strcmp(dent->d_name, "net") == 0)
 293                                                 device_list_insert(dirname2, "net", &device_list);
 294                                         else if (has_devt(dirname2))
 295                                                 device_list_insert(dirname2, dent->d_name, &device_list);
 296                                 }
 297                                 closedir(dir2);
 298                         }
 299                 }
 300                 closedir(dir);
 301         }
 302         exec_list(&device_list);
 303 }
 304
 305 static void asmlinkage sig_handler(int signum)
 306 {
 307         switch (signum) {
 308                 case SIGALRM:
 309                         exit(1);
 310                 case SIGINT:
 311                 case SIGTERM:
 312                         exit(20 + signum);
 313         }
 314 }
 315
 316 int main(int argc, char *argv[], char *envp[])
 317 {
 318         struct sigaction act;
 319
 320         logging_init("udev");
 321         udev_init_config();
 322         /* disable all logging if not explicitely requested */
 323         if (getenv("UDEV_LOG") == NULL)
 324                 udev_log_priority = 0;
 325         dbg("version %s", UDEV_VERSION);
 326
 327         /* set signal handlers */
 328         memset(&act, 0x00, sizeof(act));
 329         act.sa_handler = (void (*) (int))sig_handler;
 330         sigemptyset (&act.sa_mask);
 331         act.sa_flags = 0;
 332         sigaction(SIGALRM, &act, NULL);
 333         sigaction(SIGINT, &act, NULL);
 334         sigaction(SIGTERM, &act, NULL);
 335
 336         /* trigger timeout to prevent hanging processes */
 337         alarm(ALARM_TIMEOUT);
 338
 339         /* set environment for executed programs */
 340         setenv("ACTION", "add", 1);
 341         setenv("UDEV_START", "1", 1);
 342
 343         udev_rules_init();
 344
 345         udev_scan_block();
 346         udev_scan_class();
 347
 348         logging_close();
 349         return 0;
 350 }