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