udev_db.c

   1 /*
   2  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
   3  * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
   4  *
   5  *      This program is free software; you can redistribute it and/or modify it
   6  *      under the terms of the GNU General Public License as published by the
   7  *      Free Software Foundation version 2 of the License.
   8  *
   9  *      This program is distributed in the hope that it will be useful, but
  10  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *      General Public License for more details.
  13  *
  14  *      You should have received a copy of the GNU General Public License along
  15  *      with this program; if not, write to the Free Software Foundation, Inc.,
  16  *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17  *
  18  */
  19
  20
  21 #include <stdlib.h>
  22 #include <stdio.h>
  23 #include <string.h>
  24 #include <stddef.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <string.h>
  28 #include <errno.h>
  29 #include <dirent.h>
  30 #include <sys/stat.h>
  31 #include <sys/types.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 (list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
  85             !udev->partitions && !udev->ignore_remove) {
  86                 dbg("nothing interesting to store, create symlink");
  87                 unlink(filename);
  88                 if (symlink(udev->name, filename) != 0) {
  89                         err("unable to create db link '%s': %s", filename, strerror(errno));
  90                         return -1;
  91                 }
  92         } else {
  93                 struct name_entry *name_loop;
  94                 FILE *f;
  95
  96                 f = fopen(filename, "w");
  97                 if (f == NULL) {
  98                         err("unable to create db file '%s': %s", filename, strerror(errno));
  99                         return -1;
 100                 }
 101                 dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
 102
 103                 fprintf(f, "N:%s\n", udev->name);
 104                 list_for_each_entry(name_loop, &udev->symlink_list, node)
 105                         fprintf(f, "S:%s\n", name_loop->name);
 106                 fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
 107                 if (udev->partitions)
 108                         fprintf(f, "A:%u\n", udev->partitions);
 109                 if (udev->ignore_remove)
 110                         fprintf(f, "R:%u\n", udev->ignore_remove);
 111                 list_for_each_entry(name_loop, &udev->env_list, node)
 112                         fprintf(f, "E:%s\n", name_loop->name);
 113                 fclose(f);
 114         }
 115         return 0;
 116 }
 117
 118 int udev_db_get_device(struct udevice *udev, const char *devpath)
 119 {
 120         struct stat stats;
 121         char filename[PATH_SIZE];
 122         char line[PATH_SIZE];
 123         unsigned int maj, min;
 124         char *bufline;
 125         char *buf;
 126         size_t bufsize;
 127         size_t cur;
 128         size_t count;
 129
 130         strlcpy(udev->dev->devpath, devpath, sizeof(udev->dev->devpath));
 131         devpath_to_db_path(devpath, filename, sizeof(filename));
 132
 133         if (lstat(filename, &stats) != 0) {
 134                 info("no db file to read %s: %s", filename, strerror(errno));
 135                 return -1;
 136         }
 137         if ((stats.st_mode & S_IFMT) == S_IFLNK) {
 138                 char target[NAME_SIZE];
 139                 int target_len;
 140
 141                 info("found a symlink as db file");
 142                 target_len = readlink(filename, target, sizeof(target));
 143                 if (target_len > 0)
 144                         target[target_len] = '\0';
 145                 else {
 146                         info("error reading db link %s: %s", filename, strerror(errno));
 147                         return -1;
 148                 }
 149                 dbg("db link points to '%s'", target);
 150                 strlcpy(udev->name, target, sizeof(udev->name));
 151                 return 0;
 152         }
 153
 154         if (file_map(filename, &buf, &bufsize) != 0) {
 155                 info("error reading db file %s: %s", filename, strerror(errno));
 156                 return -1;
 157         }
 158
 159         cur = 0;
 160         while (cur < bufsize) {
 161                 count = buf_get_line(buf, bufsize, cur);
 162                 bufline = &buf[cur];
 163                 cur += count+1;
 164
 165                 switch(bufline[0]) {
 166                 case 'N':
 167                         if (count > sizeof(udev->name))
 168                                 count = sizeof(udev->name);
 169                         memcpy(udev->name, &bufline[2], count-2);
 170                         udev->name[count-2] = '\0';
 171                         break;
 172                 case 'M':
 173                         if (count > sizeof(line))
 174                                 count = sizeof(line);
 175                         memcpy(line, &bufline[2], count-2);
 176                         line[count-2] = '\0';
 177                         sscanf(line, "%u:%u", &maj, &min);
 178                         udev->devt = makedev(maj, min);
 179                         break;
 180                 case 'S':
 181                         if (count > sizeof(line))
 182                                 count =  sizeof(line);
 183                         memcpy(line, &bufline[2], count-2);
 184                         line[count-2] = '\0';
 185                         name_list_add(&udev->symlink_list, line, 0);
 186                         break;
 187                 case 'A':
 188                         if (count > sizeof(line))
 189                                 count =  sizeof(line);
 190                         memcpy(line, &bufline[2], count-2);
 191                         line[count-2] = '\0';
 192                         udev->partitions = atoi(line);
 193                         break;
 194                 case 'R':
 195                         if (count > sizeof(line))
 196                                 count =  sizeof(line);
 197                         memcpy(line, &bufline[2], count-2);
 198                         line[count-2] = '\0';
 199                         udev->ignore_remove = atoi(line);
 200                         break;
 201                 case 'E':
 202                         if (count > sizeof(line))
 203                                 count =  sizeof(line);
 204                         memcpy(line, &bufline[2], count-2);
 205                         line[count-2] = '\0';
 206                         name_list_add(&udev->env_list, line, 0);
 207                         break;
 208                 }
 209         }
 210         file_unmap(buf, bufsize);
 211
 212         if (udev->name[0] == '\0')
 213                 return -1;
 214
 215         return 0;
 216 }
 217
 218 int udev_db_delete_device(struct udevice *udev)
 219 {
 220         char filename[PATH_SIZE];
 221
 222         devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
 223         unlink(filename);
 224
 225         return 0;
 226 }
 227
 228 int udev_db_lookup_name(const char *name, char *devpath, size_t len)
 229 {
 230         char dbpath[PATH_MAX];
 231         DIR *dir;
 232         int found = 0;
 233
 234         strlcpy(dbpath, udev_root, sizeof(dbpath));
 235         strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 236         dir = opendir(dbpath);
 237         if (dir == NULL) {
 238                 info("no udev_db available '%s': %s", dbpath, strerror(errno));
 239                 return -1;
 240         }
 241
 242         while (!found) {
 243                 struct dirent *ent;
 244                 char filename[PATH_SIZE];
 245                 char nodename[PATH_SIZE];
 246                 struct stat stats;
 247                 char *bufline;
 248                 char *buf;
 249                 size_t bufsize;
 250                 size_t cur;
 251                 size_t count;
 252
 253                 ent = readdir(dir);
 254                 if (ent == NULL || ent->d_name[0] == '\0')
 255                         break;
 256                 if (ent->d_name[0] == '.')
 257                         continue;
 258
 259                 snprintf(filename, sizeof(filename), "%s/%s", dbpath, ent->d_name);
 260                 filename[sizeof(filename)-1] = '\0';
 261                 dbg("looking at '%s'", filename);
 262
 263                 if (lstat(filename, &stats) != 0) {
 264                         info("unable to read %s: %s", filename, strerror(errno));
 265                         continue;
 266                 }
 267                 if ((stats.st_mode & S_IFMT) == S_IFLNK) {
 268                         char target[NAME_SIZE];
 269                         int target_len;
 270
 271                         info("found a symlink as db file");
 272                         target_len = readlink(filename, target, sizeof(target));
 273                         if (target_len > 0)
 274                                 target[target_len] = '\0';
 275                         else {
 276                                 info("error reading db link %s: %s", filename, strerror(errno));
 277                                 return -1;
 278                         }
 279                         dbg("db link points to '%s'", target);
 280                         if (strcmp(name, target) == 0) {
 281                                 db_file_to_devpath(ent->d_name, devpath, len);
 282                                 found =1;
 283                         }
 284                         continue;
 285                 }
 286
 287                 if (file_map(filename, &buf, &bufsize) != 0) {
 288                         info("unable to read db file '%s': %s", filename, strerror(errno));
 289                         continue;
 290                 }
 291
 292                 cur = 0;
 293                 while (cur < bufsize && !found) {
 294                         count = buf_get_line(buf, bufsize, cur);
 295                         bufline = &buf[cur];
 296                         cur += count+1;
 297
 298                         switch(bufline[0]) {
 299                         case 'N':
 300                         case 'S':
 301                                 if (count > sizeof(nodename))
 302                                         count = sizeof(nodename);
 303                                 memcpy(nodename, &bufline[2], count-2);
 304                                 nodename[count-2] = '\0';
 305                                 dbg("compare '%s' '%s'", nodename, name);
 306                                 if (strcmp(nodename, name) == 0) {
 307                                         db_file_to_devpath(ent->d_name, devpath, len);
 308                                         found = 1;
 309                                 }
 310                                 break;
 311                         default:
 312                                 continue;
 313                         }
 314                 }
 315                 file_unmap(buf, bufsize);
 316         }
 317
 318         closedir(dir);
 319         if (found)
 320                 return 0;
 321         else
 322                 return -1;
 323 }
 324
 325 int udev_db_get_all_entries(struct list_head *name_list)
 326 {
 327         char dbpath[PATH_MAX];
 328         DIR *dir;
 329
 330         strlcpy(dbpath, udev_root, sizeof(dbpath));
 331         strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 332         dir = opendir(dbpath);
 333         if (dir == NULL) {
 334                 info("no udev_db available '%s': %s", dbpath, strerror(errno));
 335                 return -1;
 336         }
 337
 338         while (1) {
 339                 struct dirent *ent;
 340                 char filename[PATH_SIZE] = "/";
 341                 size_t end, i;
 342
 343                 ent = readdir(dir);
 344                 if (ent == NULL || ent->d_name[0] == '\0')
 345                         break;
 346                 if (ent->d_name[0] == '.')
 347                         continue;
 348
 349                 end = strlcat(filename, ent->d_name, sizeof(filename));
 350                 for (i = 1; i < end; i++)
 351                         if (filename[i] == PATH_TO_NAME_CHAR)
 352                                 filename[i] = '/';
 353                 name_list_add(name_list, filename, 1);
 354                 dbg("added '%s'", filename);
 355         }
 356
 357         closedir(dir);
 358         return 0;
 359 }