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