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