udev_db.c

   1 /*
   2  * udev_db.c
   3  *
   4  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
   5  * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
   6  *
   7  *      This program is free software; you can redistribute it and/or modify it
   8  *      under the terms of the GNU General Public License as published by the
   9  *      Free Software Foundation version 2 of the License.
  10  *
  11  *      This program is distributed in the hope that it will be useful, but
  12  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *      General Public License for more details.
  15  *
  16  *      You should have received a copy of the GNU General Public License along
  17  *      with this program; if not, write to the Free Software Foundation, Inc.,
  18  *      675 Mass Ave, Cambridge, MA 02139, USA.
  19  *
  20  */
  21
  22
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <stddef.h>
  27 #include <unistd.h>
  28 #include <fcntl.h>
  29 #include <string.h>
  30 #include <errno.h>
  31 #include <dirent.h>
  32 #include <sys/stat.h>
  33 #include <sys/types.h>
  34
  35 #include "udev.h"
  36
  37
  38 static int devpath_to_db_path(const char *devpath, char *filename, size_t len)
  39 {
  40         size_t start, end, i;
  41
  42         /* add location of db files */
  43         strlcpy(filename, udev_root, len);
  44         start = strlcat(filename, "/"DB_DIR, len);
  45         end = strlcat(filename, devpath, len);
  46         if (end > len)
  47                 end = len;
  48
  49         /* replace '/' to transform path into a filename */
  50         for (i = start+1; i < end; i++)
  51                 if (filename[i] == '/')
  52                         filename[i] = PATH_TO_NAME_CHAR;
  53
  54         return 0;
  55 }
  56
  57 static int db_file_to_devpath(const char *filename, char *devpath, size_t len)
  58 {
  59         size_t end, i;
  60
  61         strlcpy(devpath, "/", len);
  62         end = strlcat(devpath, filename, len);
  63
  64         /* replace PATH_TO_NAME_CHAR to transform name into devpath */
  65         for (i = 1; i < end; i++)
  66                 if (devpath[i] == PATH_TO_NAME_CHAR)
  67                         devpath[i] = '/';
  68
  69         return 0;
  70 }
  71
  72 int udev_db_add_device(struct udevice *udev)
  73 {
  74         char filename[PATH_SIZE];
  75
  76         if (udev->test_run)
  77                 return 0;
  78
  79         devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
  80         create_path(filename);
  81
  82         /*
  83          * create only a symlink with the name as the target
  84          * if we don't have any interesting data to remember
  85          */
  86         if (list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
  87             !udev->partitions && !udev->ignore_remove) {
  88                 dbg("nothing interesting to store, create symlink");
  89                 unlink(filename);
  90                 if (symlink(udev->name, filename) != 0) {
  91                         err("unable to create db link '%s': %s", filename, strerror(errno));
  92                         return -1;
  93                 }
  94         } else {
  95                 struct name_entry *name_loop;
  96                 FILE *f;
  97
  98                 f = fopen(filename, "w");
  99                 if (f == NULL) {
 100                         err("unable to create db file '%s': %s", filename, strerror(errno));
 101                         return -1;
 102                 }
 103                 dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
 104
 105                 fprintf(f, "N:%s\n", udev->name);
 106                 list_for_each_entry(name_loop, &udev->symlink_list, node)
 107                         fprintf(f, "S:%s\n", name_loop->name);
 108                 fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
 109                 if (udev->partitions)
 110                         fprintf(f, "A:%u\n", udev->partitions);
 111                 if (udev->ignore_remove)
 112                         fprintf(f, "R:%u\n", udev->ignore_remove);
 113                 list_for_each_entry(name_loop, &udev->env_list, node)
 114                         fprintf(f, "E:%s\n", name_loop->name);
 115                 fclose(f);
 116         }
 117         return 0;
 118 }
 119
 120 int udev_db_get_device(struct udevice *udev, const char *devpath)
 121 {
 122         struct stat stats;
 123         char filename[PATH_SIZE];
 124         char line[PATH_SIZE];
 125         unsigned int major, minor;
 126         char *bufline;
 127         char *buf;
 128         size_t bufsize;
 129         size_t cur;
 130         size_t count;
 131
 132         strlcpy(udev->dev->devpath, devpath, sizeof(udev->dev->devpath));
 133         devpath_to_db_path(devpath, filename, sizeof(filename));
 134
 135         if (lstat(filename, &stats) != 0) {
 136                 info("no db file to read %s: %s", filename, strerror(errno));
 137                 return -1;
 138         }
 139         if ((stats.st_mode & S_IFMT) == S_IFLNK) {
 140                 char target[NAME_SIZE];
 141                 int target_len;
 142
 143                 info("found a symlink as db file");
 144                 target_len = readlink(filename, target, sizeof(target));
 145                 if (target_len > 0)
 146                         target[target_len] = '\0';
 147                 else {
 148                         info("error reading db link %s: %s", filename, strerror(errno));
 149                         return -1;
 150                 }
 151                 dbg("db link points to '%s'", target);
 152                 strlcpy(udev->name, target, sizeof(udev->name));
 153                 return 0;
 154         }
 155
 156         if (file_map(filename, &buf, &bufsize) != 0) {
 157                 info("error reading db file %s: %s", filename, strerror(errno));
 158                 return -1;
 159         }
 160
 161         cur = 0;
 162         while (cur < bufsize) {
 163                 count = buf_get_line(buf, bufsize, cur);
 164                 bufline = &buf[cur];
 165                 cur += count+1;
 166
 167                 switch(bufline[0]) {
 168                 case 'N':
 169                         if (count > sizeof(udev->name))
 170                                 count = sizeof(udev->name);
 171                         memcpy(udev->name, &bufline[2], count-2);
 172                         udev->name[count-2] = '\0';
 173                         break;
 174                 case 'M':
 175                         if (count > sizeof(line))
 176                                 count = sizeof(line);
 177                         memcpy(line, &bufline[2], count-2);
 178                         line[count-2] = '\0';
 179                         sscanf(line, "%u:%u", &major, &minor);
 180                         udev->devt = makedev(major, minor);
 181                         break;
 182                 case 'S':
 183                         if (count > sizeof(line))
 184                                 count =  sizeof(line);
 185                         memcpy(line, &bufline[2], count-2);
 186                         line[count-2] = '\0';
 187                         name_list_add(&udev->symlink_list, line, 0);
 188                         break;
 189                 case 'A':
 190                         if (count > sizeof(line))
 191                                 count =  sizeof(line);
 192                         memcpy(line, &bufline[2], count-2);
 193                         line[count-2] = '\0';
 194                         udev->partitions = atoi(line);
 195                         break;
 196                 case 'R':
 197                         if (count > sizeof(line))
 198                                 count =  sizeof(line);
 199                         memcpy(line, &bufline[2], count-2);
 200                         line[count-2] = '\0';
 201                         udev->ignore_remove = atoi(line);
 202                         break;
 203                 case 'E':
 204                         if (count > sizeof(line))
 205                                 count =  sizeof(line);
 206                         memcpy(line, &bufline[2], count-2);
 207                         line[count-2] = '\0';
 208                         name_list_add(&udev->env_list, line, 0);
 209                         break;
 210                 }
 211         }
 212         file_unmap(buf, bufsize);
 213
 214         if (udev->name[0] == '\0')
 215                 return -1;
 216
 217         return 0;
 218 }
 219
 220 int udev_db_delete_device(struct udevice *udev)
 221 {
 222         char filename[PATH_SIZE];
 223
 224         devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
 225         unlink(filename);
 226
 227         return 0;
 228 }
 229
 230 int udev_db_lookup_name(const char *name, char *devpath, size_t len)
 231 {
 232         char dbpath[PATH_MAX];
 233         DIR *dir;
 234         int found = 0;
 235
 236         strlcpy(dbpath, udev_root, sizeof(dbpath));
 237         strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 238         dir = opendir(dbpath);
 239         if (dir == NULL) {
 240                 info("no udev_db available '%s': %s", dbpath, strerror(errno));
 241                 return -1;
 242         }
 243
 244         while (!found) {
 245                 struct dirent *ent;
 246                 char filename[PATH_SIZE];
 247                 char nodename[PATH_SIZE];
 248                 struct stat stats;
 249                 char *bufline;
 250                 char *buf;
 251                 size_t bufsize;
 252                 size_t cur;
 253                 size_t count;
 254
 255                 ent = readdir(dir);
 256                 if (ent == NULL || ent->d_name[0] == '\0')
 257                         break;
 258                 if (ent->d_name[0] == '.')
 259                         continue;
 260
 261                 snprintf(filename, sizeof(filename), "%s/%s", dbpath, ent->d_name);
 262                 filename[sizeof(filename)-1] = '\0';
 263                 dbg("looking at '%s'", filename);
 264
 265                 if (lstat(filename, &stats) != 0) {
 266                         info("unable to read %s: %s", filename, strerror(errno));
 267                         continue;
 268                 }
 269                 if ((stats.st_mode & S_IFMT) == S_IFLNK) {
 270                         char target[NAME_SIZE];
 271                         int target_len;
 272
 273                         info("found a symlink as db file");
 274                         target_len = readlink(filename, target, sizeof(target));
 275                         if (target_len > 0)
 276                                 target[target_len] = '\0';
 277                         else {
 278                                 info("error reading db link %s: %s", filename, strerror(errno));
 279                                 return -1;
 280                         }
 281                         dbg("db link points to '%s'", target);
 282                         if (strcmp(name, target) == 0) {
 283                                 db_file_to_devpath(ent->d_name, devpath, len);
 284                                 found =1;
 285                         }
 286                         continue;
 287                 }
 288
 289                 if (file_map(filename, &buf, &bufsize) != 0) {
 290                         info("unable to read db file '%s': %s", filename, strerror(errno));
 291                         continue;
 292                 }
 293
 294                 cur = 0;
 295                 while (cur < bufsize && !found) {
 296                         count = buf_get_line(buf, bufsize, cur);
 297                         bufline = &buf[cur];
 298                         cur += count+1;
 299
 300                         switch(bufline[0]) {
 301                         case 'N':
 302                         case 'S':
 303                                 if (count > sizeof(nodename))
 304                                         count = sizeof(nodename);
 305                                 memcpy(nodename, &bufline[2], count-2);
 306                                 nodename[count-2] = '\0';
 307                                 dbg("compare '%s' '%s'", nodename, name);
 308                                 if (strcmp(nodename, name) == 0) {
 309                                         db_file_to_devpath(ent->d_name, devpath, len);
 310                                         found = 1;
 311                                 }
 312                                 break;
 313                         default:
 314                                 continue;
 315                         }
 316                 }
 317                 file_unmap(buf, bufsize);
 318         }
 319
 320         closedir(dir);
 321         if (found)
 322                 return 0;
 323         else
 324                 return -1;
 325 }
 326
 327 int udev_db_get_all_entries(struct list_head *name_list)
 328 {
 329         char dbpath[PATH_MAX];
 330         DIR *dir;
 331
 332         strlcpy(dbpath, udev_root, sizeof(dbpath));
 333         strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 334         dir = opendir(dbpath);
 335         if (dir == NULL) {
 336                 info("no udev_db available '%s': %s", dbpath, strerror(errno));
 337                 return -1;
 338         }
 339
 340         while (1) {
 341                 struct dirent *ent;
 342                 char filename[PATH_SIZE] = "/";
 343                 size_t end, i;
 344
 345                 ent = readdir(dir);
 346                 if (ent == NULL || ent->d_name[0] == '\0')
 347                         break;
 348                 if (ent->d_name[0] == '.')
 349                         continue;
 350
 351                 end = strlcat(filename, ent->d_name, sizeof(filename));
 352                 for (i = 1; i < end; i++)
 353                         if (filename[i] == PATH_TO_NAME_CHAR)
 354                                 filename[i] = '/';
 355                 name_list_add(name_list, filename, 1);
 356                 dbg("added '%s'", filename);
 357         }
 358
 359         closedir(dir);
 360         return 0;
 361 }