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 size_t devpath_to_db_path(const char *devpath, char *filename, size_t len)
  37 {
  38         size_t start;
  39
  40         /* add location of db files */
  41         strlcpy(filename, udev_root, len);
  42         start = strlcat(filename, "/"DB_DIR"/", len);
  43         strlcat(filename, devpath, len);
  44         return path_encode(&filename[start], len - start);
  45 }
  46
  47 /* reverse mapping from the device file name to the devpath */
  48 static int name_index(const char *devpath, const char *name, int add)
  49 {
  50         char device[PATH_SIZE];
  51         char filename[PATH_SIZE * 2];
  52         size_t start;
  53         int fd;
  54
  55         /* directory with device name */
  56         strlcpy(filename, udev_root, sizeof(filename));
  57         start = strlcat(filename, "/"DB_NAME_INDEX_DIR"/", sizeof(filename));
  58         strlcat(filename, name, sizeof(filename));
  59         path_encode(&filename[start], sizeof(filename) - start);
  60         /* entry with the devpath */
  61         strlcpy(device, devpath, sizeof(device));
  62         path_encode(device, sizeof(device));
  63         strlcat(filename, "/", sizeof(filename));
  64         strlcat(filename, device, sizeof(filename));
  65
  66         if (add) {
  67                 info("creating index: '%s'", filename);
  68                 create_path(filename);
  69                 fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
  70                 if (fd > 0)
  71                         close(fd);
  72         } else {
  73                 info("removing index: '%s'", filename);
  74                 unlink(filename);
  75                 delete_path(filename);
  76         }
  77         return 0;
  78 }
  79
  80 int udev_db_get_devices_by_name(const char *name, struct list_head *name_list)
  81 {
  82         char dirname[PATH_MAX];
  83         size_t start;
  84         DIR *dir;
  85         int rc = 0;
  86
  87         strlcpy(dirname, udev_root, sizeof(dirname));
  88         start = strlcat(dirname, "/"DB_NAME_INDEX_DIR"/", sizeof(dirname));
  89         strlcat(dirname, name, sizeof(dirname));
  90         path_encode(&dirname[start], sizeof(dirname) - start);
  91
  92         dir = opendir(dirname);
  93         if (dir == NULL) {
  94                 info("no index directory '%s': %s", dirname, strerror(errno));
  95                 rc = -1;
  96                 goto out;
  97         }
  98
  99         info("found index directory '%s'", dirname);
 100         while (1) {
 101                 struct dirent *ent;
 102                 char device[PATH_SIZE];
 103
 104                 ent = readdir(dir);
 105                 if (ent == NULL || ent->d_name[0] == '\0')
 106                         break;
 107                 if (ent->d_name[0] == '.')
 108                         continue;
 109
 110                 strlcpy(device, ent->d_name, sizeof(device));
 111                 path_decode(device);
 112                 name_list_add(name_list, device, 0);
 113                 rc++;
 114         }
 115         closedir(dir);
 116 out:
 117         return rc;
 118 }
 119
 120 int udev_db_add_device(struct udevice *udev)
 121 {
 122         char filename[PATH_SIZE];
 123
 124         if (udev->test_run)
 125                 return 0;
 126
 127         devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
 128         create_path(filename);
 129         unlink(filename);
 130
 131         /*
 132          * don't waste tmpfs memory pages, if we don't have any data to store
 133          * create fake db-file; store the node-name in a symlink target
 134          */
 135         if (list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
 136             !udev->partitions && !udev->ignore_remove) {
 137                 dbg("nothing interesting to store, create symlink");
 138                 if (symlink(udev->name, filename) != 0) {
 139                         err("unable to create db link '%s': %s", filename, strerror(errno));
 140                         return -1;
 141                 }
 142         } else {
 143                 FILE *f;
 144                 struct name_entry *name_loop;
 145
 146                 f = fopen(filename, "w");
 147                 if (f == NULL) {
 148                         err("unable to create db file '%s': %s", filename, strerror(errno));
 149                         return -1;
 150                 }
 151                 dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
 152
 153                 fprintf(f, "N:%s\n", udev->name);
 154                 list_for_each_entry(name_loop, &udev->symlink_list, node) {
 155                         fprintf(f, "S:%s\n", name_loop->name);
 156                         /* add symlink-name to index */
 157                         name_index(udev->dev->devpath, name_loop->name, 1);
 158                 }
 159                 fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
 160                 if (udev->link_priority != 0)
 161                         fprintf(f, "L:%u\n", udev->link_priority);
 162                 if (udev->partitions != 0)
 163                         fprintf(f, "A:%u\n", udev->partitions);
 164                 if (udev->ignore_remove)
 165                         fprintf(f, "R:%u\n", udev->ignore_remove);
 166                 list_for_each_entry(name_loop, &udev->env_list, node)
 167                         fprintf(f, "E:%s\n", name_loop->name);
 168                 fclose(f);
 169         }
 170
 171         /* add name to index */
 172         name_index(udev->dev->devpath, udev->name, 1);
 173
 174         return 0;
 175 }
 176
 177 int udev_db_get_device(struct udevice *udev, const char *devpath)
 178 {
 179         struct stat stats;
 180         char filename[PATH_SIZE];
 181         char line[PATH_SIZE];
 182         unsigned int maj, min;
 183         char *bufline;
 184         char *buf;
 185         size_t bufsize;
 186         size_t cur;
 187         size_t count;
 188
 189         sysfs_device_set_values(udev->dev, devpath, NULL, NULL);
 190         devpath_to_db_path(devpath, filename, sizeof(filename));
 191
 192         if (lstat(filename, &stats) != 0) {
 193                 info("no db file to read %s: %s", filename, strerror(errno));
 194                 return -1;
 195         }
 196         if ((stats.st_mode & S_IFMT) == S_IFLNK) {
 197                 char target[NAME_SIZE];
 198                 int target_len;
 199
 200                 info("found a symlink as db file");
 201                 target_len = readlink(filename, target, sizeof(target));
 202                 if (target_len > 0)
 203                         target[target_len] = '\0';
 204                 else {
 205                         info("error reading db link %s: %s", filename, strerror(errno));
 206                         return -1;
 207                 }
 208                 dbg("db link points to '%s'", target);
 209                 strlcpy(udev->name, target, sizeof(udev->name));
 210                 return 0;
 211         }
 212
 213         if (file_map(filename, &buf, &bufsize) != 0) {
 214                 info("error reading db file %s: %s", filename, strerror(errno));
 215                 return -1;
 216         }
 217
 218         cur = 0;
 219         while (cur < bufsize) {
 220                 count = buf_get_line(buf, bufsize, cur);
 221                 bufline = &buf[cur];
 222                 cur += count+1;
 223
 224                 switch(bufline[0]) {
 225                 case 'N':
 226                         if (count > sizeof(udev->name))
 227                                 count = sizeof(udev->name);
 228                         memcpy(udev->name, &bufline[2], count-2);
 229                         udev->name[count-2] = '\0';
 230                         break;
 231                 case 'M':
 232                         if (count > sizeof(line))
 233                                 count = sizeof(line);
 234                         memcpy(line, &bufline[2], count-2);
 235                         line[count-2] = '\0';
 236                         sscanf(line, "%u:%u", &maj, &min);
 237                         udev->devt = makedev(maj, min);
 238                         break;
 239                 case 'S':
 240                         if (count > sizeof(line))
 241                                 count =  sizeof(line);
 242                         memcpy(line, &bufline[2], count-2);
 243                         line[count-2] = '\0';
 244                         name_list_add(&udev->symlink_list, line, 0);
 245                         break;
 246                 case 'L':
 247                         if (count > sizeof(line))
 248                                 count =  sizeof(line);
 249                         memcpy(line, &bufline[2], count-2);
 250                         line[count-2] = '\0';
 251                         udev->link_priority = atoi(line);
 252                         break;
 253                 case 'A':
 254                         if (count > sizeof(line))
 255                                 count =  sizeof(line);
 256                         memcpy(line, &bufline[2], count-2);
 257                         line[count-2] = '\0';
 258                         udev->partitions = atoi(line);
 259                         break;
 260                 case 'R':
 261                         if (count > sizeof(line))
 262                                 count =  sizeof(line);
 263                         memcpy(line, &bufline[2], count-2);
 264                         line[count-2] = '\0';
 265                         udev->ignore_remove = atoi(line);
 266                         break;
 267                 case 'E':
 268                         if (count > sizeof(line))
 269                                 count =  sizeof(line);
 270                         memcpy(line, &bufline[2], count-2);
 271                         line[count-2] = '\0';
 272                         name_list_add(&udev->env_list, line, 0);
 273                         break;
 274                 }
 275         }
 276         file_unmap(buf, bufsize);
 277
 278         if (udev->name[0] == '\0')
 279                 return -1;
 280
 281         return 0;
 282 }
 283
 284 int udev_db_delete_device(struct udevice *udev)
 285 {
 286         char filename[PATH_SIZE];
 287         struct name_entry *name_loop;
 288
 289         if (udev->test_run)
 290                 return 0;
 291
 292         devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
 293         unlink(filename);
 294
 295         name_index(udev->dev->devpath, udev->name, 0);
 296         list_for_each_entry(name_loop, &udev->symlink_list, node)
 297                 name_index(udev->dev->devpath, name_loop->name, 0);
 298
 299         return 0;
 300 }
 301
 302 int udev_db_get_all_entries(struct list_head *name_list)
 303 {
 304         char dbpath[PATH_MAX];
 305         DIR *dir;
 306
 307         strlcpy(dbpath, udev_root, sizeof(dbpath));
 308         strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 309         dir = opendir(dbpath);
 310         if (dir == NULL) {
 311                 info("no udev_db available '%s': %s", dbpath, strerror(errno));
 312                 return -1;
 313         }
 314
 315         while (1) {
 316                 struct dirent *ent;
 317                 char device[PATH_SIZE];
 318
 319                 ent = readdir(dir);
 320                 if (ent == NULL || ent->d_name[0] == '\0')
 321                         break;
 322                 if (ent->d_name[0] == '.')
 323                         continue;
 324
 325                 strlcpy(device, ent->d_name, sizeof(device));
 326                 path_decode(device);
 327                 name_list_add(name_list, device, 1);
 328                 dbg("added '%s'", device);
 329         }
 330
 331         closedir(dir);
 332         return 0;
 333 }