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         struct name_entry *name_loop;
  74         FILE *f;
  75
  76         if (udev->test_run)
  77                 return 0;
  78
  79         /* don't write anything if udev created only the node with the
  80          * kernel name without any interesting data to remember
  81          */
  82         if (strcmp(udev->name, udev->dev->kernel_name) == 0 &&
  83             list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
  84             !udev->partitions && !udev->ignore_remove) {
  85                 dbg("nothing interesting to store in udevdb, skip");
  86                 goto exit;
  87         }
  88
  89         devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
  90         create_path(filename);
  91         f = fopen(filename, "w");
  92         if (f == NULL) {
  93                 err("unable to create db file '%s': %s", filename, strerror(errno));
  94                 return -1;
  95         }
  96         dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
  97
  98         fprintf(f, "N:%s\n", udev->name);
  99         list_for_each_entry(name_loop, &udev->symlink_list, node)
 100                 fprintf(f, "S:%s\n", name_loop->name);
 101         fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
 102         if (udev->partitions)
 103                 fprintf(f, "A:%u\n", udev->partitions);
 104         if (udev->ignore_remove)
 105                 fprintf(f, "R:%u\n", udev->ignore_remove);
 106         list_for_each_entry(name_loop, &udev->env_list, node)
 107                 fprintf(f, "E:%s\n", name_loop->name);
 108         fclose(f);
 109
 110 exit:
 111         return 0;
 112 }
 113
 114 int udev_db_get_device(struct udevice *udev, const char *devpath)
 115 {
 116         char filename[PATH_SIZE];
 117         char line[PATH_SIZE];
 118         unsigned int major, minor;
 119         char *bufline;
 120         char *buf;
 121         size_t bufsize;
 122         size_t cur;
 123         size_t count;
 124
 125         devpath_to_db_path(devpath, filename, sizeof(filename));
 126         if (file_map(filename, &buf, &bufsize) != 0) {
 127                 info("no db file to read %s: %s", filename, strerror(errno));
 128                 return -1;
 129         }
 130
 131         strlcpy(udev->dev->devpath, devpath, sizeof(udev->dev->devpath));
 132         cur = 0;
 133         while (cur < bufsize) {
 134                 count = buf_get_line(buf, bufsize, cur);
 135                 bufline = &buf[cur];
 136                 cur += count+1;
 137
 138                 switch(bufline[0]) {
 139                 case 'N':
 140                         if (count > sizeof(udev->name))
 141                                 count = sizeof(udev->name);
 142                         memcpy(udev->name, &bufline[2], count-2);
 143                         udev->name[count-2] = '\0';
 144                         break;
 145                 case 'M':
 146                         if (count > sizeof(line))
 147                                 count = sizeof(line);
 148                         memcpy(line, &bufline[2], count-2);
 149                         line[count-2] = '\0';
 150                         sscanf(line, "%u:%u", &major, &minor);
 151                         udev->devt = makedev(major, minor);
 152                         break;
 153                 case 'S':
 154                         if (count > sizeof(line))
 155                                 count =  sizeof(line);
 156                         memcpy(line, &bufline[2], count-2);
 157                         line[count-2] = '\0';
 158                         name_list_add(&udev->symlink_list, line, 0);
 159                         break;
 160                 case 'A':
 161                         if (count > sizeof(line))
 162                                 count =  sizeof(line);
 163                         memcpy(line, &bufline[2], count-2);
 164                         line[count-2] = '\0';
 165                         udev->partitions = atoi(line);
 166                         break;
 167                 case 'R':
 168                         if (count > sizeof(line))
 169                                 count =  sizeof(line);
 170                         memcpy(line, &bufline[2], count-2);
 171                         line[count-2] = '\0';
 172                         udev->ignore_remove = atoi(line);
 173                         break;
 174                 case 'E':
 175                         if (count > sizeof(line))
 176                                 count =  sizeof(line);
 177                         memcpy(line, &bufline[2], count-2);
 178                         line[count-2] = '\0';
 179                         name_list_add(&udev->env_list, line, 0);
 180                         break;
 181                 }
 182         }
 183         file_unmap(buf, bufsize);
 184
 185         if (udev->name[0] == '\0')
 186                 return -1;
 187
 188         return 0;
 189 }
 190
 191 int udev_db_delete_device(struct udevice *udev)
 192 {
 193         char filename[PATH_SIZE];
 194
 195         devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
 196         unlink(filename);
 197
 198         return 0;
 199 }
 200
 201 int udev_db_lookup_name(const char *name, char *devpath, size_t len)
 202 {
 203         char dbpath[PATH_MAX];
 204         DIR *dir;
 205         int found = 0;
 206
 207         strlcpy(dbpath, udev_root, sizeof(dbpath));
 208         strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 209         dir = opendir(dbpath);
 210         if (dir == NULL) {
 211                 info("no udev_db available '%s': %s", dbpath, strerror(errno));
 212                 return -1;
 213         }
 214
 215         while (!found) {
 216                 struct dirent *ent;
 217                 char filename[PATH_SIZE];
 218                 char nodename[PATH_SIZE];
 219                 char *bufline;
 220                 char *buf;
 221                 size_t bufsize;
 222                 size_t cur;
 223                 size_t count;
 224
 225                 ent = readdir(dir);
 226                 if (ent == NULL || ent->d_name[0] == '\0')
 227                         break;
 228                 if (ent->d_name[0] == '.')
 229                         continue;
 230
 231                 snprintf(filename, sizeof(filename), "%s/%s", dbpath, ent->d_name);
 232                 filename[sizeof(filename)-1] = '\0';
 233                 dbg("looking at '%s'", filename);
 234
 235                 if (file_map(filename, &buf, &bufsize) != 0) {
 236                         err("unable to read db file '%s': %s", filename, strerror(errno));
 237                         continue;
 238                 }
 239
 240                 cur = 0;
 241                 while (cur < bufsize && !found) {
 242                         count = buf_get_line(buf, bufsize, cur);
 243                         bufline = &buf[cur];
 244                         cur += count+1;
 245
 246                         switch(bufline[0]) {
 247                         case 'N':
 248                         case 'S':
 249                                 if (count > sizeof(nodename))
 250                                         count = sizeof(nodename);
 251                                 memcpy(nodename, &bufline[2], count-2);
 252                                 nodename[count-2] = '\0';
 253                                 dbg("compare '%s' '%s'", nodename, name);
 254                                 if (strcmp(nodename, name) == 0) {
 255                                         db_file_to_devpath(ent->d_name, devpath, len);
 256                                         found = 1;
 257                                 }
 258                                 break;
 259                         default:
 260                                 continue;
 261                         }
 262                 }
 263                 file_unmap(buf, bufsize);
 264         }
 265
 266         closedir(dir);
 267         if (found)
 268                 return 0;
 269         else
 270                 return -1;
 271 }
 272
 273 int udev_db_get_all_entries(struct list_head *name_list)
 274 {
 275         char dbpath[PATH_MAX];
 276         DIR *dir;
 277
 278         strlcpy(dbpath, udev_root, sizeof(dbpath));
 279         strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 280         dir = opendir(dbpath);
 281         if (dir == NULL) {
 282                 info("no udev_db available '%s': %s", dbpath, strerror(errno));
 283                 return -1;
 284         }
 285
 286         while (1) {
 287                 struct dirent *ent;
 288                 char filename[PATH_SIZE] = "/";
 289                 size_t end, i;
 290
 291                 ent = readdir(dir);
 292                 if (ent == NULL || ent->d_name[0] == '\0')
 293                         break;
 294                 if (ent->d_name[0] == '.')
 295                         continue;
 296
 297                 end = strlcat(filename, ent->d_name, sizeof(filename));
 298                 for (i = 1; i < end; i++)
 299                         if (filename[i] == PATH_TO_NAME_CHAR)
 300                                 filename[i] = '/';
 301                 name_list_add(name_list, filename, 1);
 302                 dbg("added '%s'", filename);
 303         }
 304
 305         closedir(dir);
 306         return 0;
 307 }