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_run && !list_empty(&udev.run_list)) {
 130                 struct name_entry *name_loop;
 131
 132                 dbg("executing run list");
 133                 list_for_each_entry(name_loop, &udev.run_list, node)
 134                         execute_command(name_loop->name, udev.subsystem);
 135         }
 136
 137         /* run dev.d/ scripts if we created a node or changed a netif name */
 138         if (udev_dev_d && udev.devname[0] != '\0') {
 139                 setenv("DEVNAME", udev.devname, 1);
 140                 udev_multiplex_directory(&udev, DEVD_DIR, DEVD_SUFFIX);
 141         }
 142
 143         sysfs_close_class_device(class_dev);
 144         udev_cleanup_device(&udev);
 145
 146         return 0;
 147 }
 148
 149 static void exec_list(struct list_head *device_list)
 150 {
 151         struct device *loop_device;
 152         struct device *tmp_device;
 153         int i;
 154
 155         /* handle the "first" type devices first */
 156         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 157                 for (i = 0; first_list[i] != NULL; i++) {
 158                         if (strncmp(loop_device->path, first_list[i], strlen(first_list[i])) == 0) {
 159                                 add_device(loop_device->path, loop_device->subsys);
 160                                 list_del(&loop_device->node);
 161                                 free(loop_device);
 162                                 break;
 163                         }
 164                 }
 165         }
 166
 167         /* handle the devices we are allowed to, excluding the "last" type devices */
 168         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 169                 int found = 0;
 170                 for (i = 0; last_list[i] != NULL; i++) {
 171                         if (strncmp(loop_device->path, last_list[i], strlen(last_list[i])) == 0) {
 172                                 found = 1;
 173                                 break;
 174                         }
 175                 }
 176                 if (found)
 177                         continue;
 178
 179                 add_device(loop_device->path, loop_device->subsys);
 180                 list_del(&loop_device->node);
 181                 free(loop_device);
 182         }
 183
 184         /* handle the rest of the devices left over, if any */
 185         list_for_each_entry_safe(loop_device, tmp_device, device_list, node) {
 186                 add_device(loop_device->path, loop_device->subsys);
 187                 list_del(&loop_device->node);
 188                 free(loop_device);
 189         }
 190 }
 191
 192 static int has_devt(const char *directory)
 193 {
 194         char filename[PATH_SIZE];
 195         struct stat statbuf;
 196
 197         snprintf(filename, sizeof(filename), "%s/dev", directory);
 198         filename[sizeof(filename)-1] = '\0';
 199
 200         if (stat(filename, &statbuf) == 0)
 201                 return 1;
 202
 203         return 0;
 204 }
 205
 206 static void udev_scan_block(void)
 207 {
 208         char base[PATH_SIZE];
 209         DIR *dir;
 210         struct dirent *dent;
 211         LIST_HEAD(device_list);
 212
 213         snprintf(base, sizeof(base), "%s/block", sysfs_path);
 214         base[sizeof(base)-1] = '\0';
 215
 216         dir = opendir(base);
 217         if (dir != NULL) {
 218                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 219                         char dirname[PATH_SIZE];
 220                         DIR *dir2;
 221                         struct dirent *dent2;
 222
 223                         if (dent->d_name[0] == '.')
 224                                 continue;
 225
 226                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 227                         dirname[sizeof(dirname)-1] = '\0';
 228                         if (has_devt(dirname))
 229                                 device_list_insert(dirname, "block", &device_list);
 230                         else
 231                                 continue;
 232
 233                         /* look for partitions */
 234                         dir2 = opendir(dirname);
 235                         if (dir2 != NULL) {
 236                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 237                                         char dirname2[PATH_SIZE];
 238
 239                                         if (dent2->d_name[0] == '.')
 240                                                 continue;
 241
 242                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 243                                         dirname2[sizeof(dirname2)-1] = '\0';
 244
 245                                         if (has_devt(dirname2))
 246                                                 device_list_insert(dirname2, "block", &device_list);
 247                                 }
 248                                 closedir(dir2);
 249                         }
 250                 }
 251                 closedir(dir);
 252         }
 253         exec_list(&device_list);
 254 }
 255
 256 static void udev_scan_class(void)
 257 {
 258         char base[PATH_SIZE];
 259         DIR *dir;
 260         struct dirent *dent;
 261         LIST_HEAD(device_list);
 262
 263         snprintf(base, sizeof(base), "%s/class", sysfs_path);
 264         base[sizeof(base)-1] = '\0';
 265
 266         dir = opendir(base);
 267         if (dir != NULL) {
 268                 for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 269                         char dirname[PATH_SIZE];
 270                         DIR *dir2;
 271                         struct dirent *dent2;
 272
 273                         if (dent->d_name[0] == '.')
 274                                 continue;
 275
 276                         snprintf(dirname, sizeof(dirname), "%s/%s", base, dent->d_name);
 277                         dirname[sizeof(dirname)-1] = '\0';
 278
 279                         dir2 = opendir(dirname);
 280                         if (dir2 != NULL) {
 281                                 for (dent2 = readdir(dir2); dent2 != NULL; dent2 = readdir(dir2)) {
 282                                         char dirname2[PATH_SIZE];
 283
 284                                         if (dent2->d_name[0] == '.')
 285                                                 continue;
 286
 287                                         snprintf(dirname2, sizeof(dirname2), "%s/%s", dirname, dent2->d_name);
 288                                         dirname2[sizeof(dirname2)-1] = '\0';
 289
 290                                         /* pass the net class as it is */
 291                                         if (strcmp(dent->d_name, "net") == 0)
 292                                                 device_list_insert(dirname2, "net", &device_list);
 293                                         else if (has_devt(dirname2))
 294                                                 device_list_insert(dirname2, dent->d_name, &device_list);
 295                                 }
 296                                 closedir(dir2);
 297                         }
 298                 }
 299                 closedir(dir);
 300         }
 301         exec_list(&device_list);
 302 }
 303
 304 static void asmlinkage sig_handler(int signum)
 305 {
 306         switch (signum) {
 307                 case SIGALRM:
 308                         exit(1);
 309                 case SIGINT:
 310                 case SIGTERM:
 311                         exit(20 + signum);
 312         }
 313 }
 314
 315 int main(int argc, char *argv[], char *envp[])
 316 {
 317         struct sigaction act;
 318
 319         logging_init("udev");
 320         udev_init_config();
 321         /* disable all logging if not explicitely requested */
 322         if (getenv("UDEV_LOG") == NULL)
 323                 udev_log_priority = 0;
 324         dbg("version %s", UDEV_VERSION);
 325
 326         /* set signal handlers */
 327         memset(&act, 0x00, sizeof(act));
 328         act.sa_handler = (void (*) (int))sig_handler;
 329         sigemptyset (&act.sa_mask);
 330         act.sa_flags = 0;
 331         sigaction(SIGALRM, &act, NULL);
 332         sigaction(SIGINT, &act, NULL);
 333         sigaction(SIGTERM, &act, NULL);
 334
 335         /* trigger timeout to prevent hanging processes */
 336         alarm(ALARM_TIMEOUT);
 337
 338         /* set environment for executed programs */
 339         setenv("ACTION", "add", 1);
 340         setenv("UDEV_START", "1", 1);
 341
 342         udev_rules_init();
 343
 344         udev_scan_block();
 345         udev_scan_class();
 346
 347         logging_close();
 348         return 0;
 349 }