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 "libsysfs/sysfs/libsysfs.h"
  34 #include "udev_libc_wrapper.h"
  35 #include "udev.h"
  36 #include "udev_utils.h"
  37 #include "logging.h"
  38 #include "udev_db.h"
  39
  40 #define PATH_TO_NAME_CHAR               '@'
  41
  42 static int get_db_filename(const char *devpath, char *filename, size_t len)
  43 {
  44         size_t start, end, i;
  45
  46         start = strlcpy(filename, udev_db_path, len);
  47         end = strlcat(filename, devpath, len);
  48         if (end > len)
  49                 end = len;
  50
  51         /* replace '/' to transform path into a filename */
  52         for (i = start+1; i < end; i++)
  53                 if (filename[i] == '/')
  54                         filename[i] = PATH_TO_NAME_CHAR;
  55
  56         return 0;
  57 }
  58
  59 int udev_db_add_device(struct udevice *udev)
  60 {
  61         char filename[PATH_SIZE];
  62         struct name_entry *name_loop;
  63         FILE *f;
  64
  65         if (udev->test_run)
  66                 return 0;
  67
  68         /* don't write anything if udev created only the node with the
  69          * kernel name without any interesting data to remember
  70          */
  71         if (strcmp(udev->name, udev->kernel_name) == 0 &&
  72             list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
  73             !udev->partitions && !udev->ignore_remove) {
  74                 dbg("nothing interesting to store in udevdb, skip");
  75                 goto exit;
  76         }
  77
  78         get_db_filename(udev->devpath, filename, sizeof(filename));
  79         create_path(filename);
  80         f = fopen(filename, "w");
  81         if (f == NULL) {
  82                 err("unable to create db file '%s'", filename);
  83                 return -1;
  84         }
  85         dbg("storing data for device '%s' in '%s'", udev->devpath, filename);
  86
  87         fprintf(f, "P:%s\n", udev->devpath);
  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 exit:
 101         return 0;
 102 }
 103
 104 static int parse_db_file(struct udevice *udev, const char *filename)
 105 {
 106         char line[PATH_SIZE];
 107         unsigned int major, minor;
 108         char *bufline;
 109         char *buf;
 110         size_t bufsize;
 111         size_t cur;
 112         size_t count;
 113
 114         if (file_map(filename, &buf, &bufsize) != 0) {
 115                 dbg("no db file to read '%s'", filename);
 116                 return -1;
 117         }
 118
 119         cur = 0;
 120         while (cur < bufsize) {
 121                 count = buf_get_line(buf, bufsize, cur);
 122                 bufline = &buf[cur];
 123                 cur += count+1;
 124
 125                 switch(bufline[0]) {
 126                 case 'P':
 127                         if (count > sizeof(udev->devpath))
 128                                 count = sizeof(udev->devpath);
 129                         memcpy(udev->devpath, &bufline[2], count-2);
 130                         udev->devpath[count-2] = '\0';
 131                         break;
 132                 case 'N':
 133                         if (count > sizeof(udev->name))
 134                                 count = sizeof(udev->name);
 135                         memcpy(udev->name, &bufline[2], count-2);
 136                         udev->name[count-2] = '\0';
 137                         break;
 138                 case 'M':
 139                         if (count > sizeof(line))
 140                                 count = sizeof(line);
 141                         memcpy(line, &bufline[2], count-2);
 142                         line[count-2] = '\0';
 143                         sscanf(line, "%u:%u", &major, &minor);
 144                         udev->devt = makedev(major, minor);
 145                         break;
 146                 case 'S':
 147                         if (count > sizeof(line))
 148                                 count =  sizeof(line);
 149                         memcpy(line, &bufline[2], count-2);
 150                         line[count-2] = '\0';
 151                         name_list_add(&udev->symlink_list, line, 0);
 152                         break;
 153                 case 'A':
 154                         if (count > sizeof(line))
 155                                 count =  sizeof(line);
 156                         memcpy(line, &bufline[2], count-2);
 157                         line[count-2] = '\0';
 158                         udev->partitions = atoi(line);
 159                         break;
 160                 case 'R':
 161                         if (count > sizeof(line))
 162                                 count =  sizeof(line);
 163                         memcpy(line, &bufline[2], count-2);
 164                         line[count-2] = '\0';
 165                         udev->ignore_remove = atoi(line);
 166                         break;
 167                 case 'E':
 168                         if (count > sizeof(line))
 169                                 count =  sizeof(line);
 170                         memcpy(line, &bufline[2], count-2);
 171                         line[count-2] = '\0';
 172                         name_list_add(&udev->env_list, line, 0);
 173                         break;
 174                 }
 175         }
 176         file_unmap(buf, bufsize);
 177
 178         if (udev->name[0] == '\0')
 179                 return -1;
 180
 181         return 0;
 182 }
 183
 184 int udev_db_delete_device(struct udevice *udev)
 185 {
 186         char filename[PATH_SIZE];
 187
 188         get_db_filename(udev->devpath, filename, sizeof(filename));
 189         unlink(filename);
 190
 191         return 0;
 192 }
 193
 194 int udev_db_get_device(struct udevice *udev, const char *devpath)
 195 {
 196         char filename[PATH_SIZE];
 197
 198         get_db_filename(devpath, filename, sizeof(filename));
 199         if (parse_db_file(udev, filename) != 0)
 200                 return -1;
 201
 202         return 0;
 203 }
 204
 205 int udev_db_search_name(const char *name, char *devpath, size_t len)
 206 {
 207         DIR *dir;
 208         char path[PATH_SIZE];
 209         int found = 0;
 210
 211         dir = opendir(udev_db_path);
 212         if (dir == NULL) {
 213                 err("unable to open udev_db '%s'", udev_db_path);
 214                 return -1;
 215         }
 216
 217         while (!found) {
 218                 struct dirent *ent;
 219                 char filename[PATH_SIZE];
 220                 char nodename[PATH_SIZE];
 221                 char *bufline;
 222                 char *buf;
 223                 size_t bufsize;
 224                 size_t cur;
 225                 size_t count;
 226
 227                 ent = readdir(dir);
 228                 if (ent == NULL || ent->d_name[0] == '\0')
 229                         break;
 230
 231                 if (ent->d_name[0] == '.')
 232                         continue;
 233
 234                 snprintf(filename, sizeof(filename), "%s/%s", udev_db_path, ent->d_name);
 235                 filename[sizeof(filename)-1] = '\0';
 236                 dbg("looking at '%s'", filename);
 237
 238                 if (file_map(filename, &buf, &bufsize) != 0) {
 239                         err("unable to read db file '%s'", filename);
 240                         continue;
 241                 }
 242
 243                 cur = 0;
 244                 while (cur < bufsize && !found) {
 245                         count = buf_get_line(buf, bufsize, cur);
 246                         bufline = &buf[cur];
 247                         cur += count+1;
 248
 249                         switch(bufline[0]) {
 250                         case 'P':
 251                                 if (count > sizeof(path))
 252                                         count = sizeof(path);
 253                                 memcpy(path, &bufline[2], count-2);
 254                                 path[count-2] = '\0';
 255                                 break;
 256                         case 'N':
 257                         case 'S':
 258                                 if (count > sizeof(nodename))
 259                                         count = sizeof(nodename);
 260                                 memcpy(nodename, &bufline[2], count-2);
 261                                 nodename[count-2] = '\0';
 262                                 dbg("compare '%s' '%s'", nodename, name);
 263                                 if (strcmp(nodename, name) == 0) {
 264                                         found = 1;
 265                                         break;
 266                                 }
 267                                 break;
 268                         default:
 269                                 continue;
 270                         }
 271                 }
 272                 file_unmap(buf, bufsize);
 273         }
 274
 275         closedir(dir);
 276         if (found) {
 277                 strlcpy(devpath, path, len);
 278                 return 0;
 279         } else
 280                 return -1;
 281 }
 282
 283 int udev_db_get_all_entries(struct list_head *name_list)
 284 {
 285         DIR *dir;
 286
 287         dir = opendir(udev_db_path);
 288         if (dir == NULL) {
 289                 err("unable to open udev_db '%s'", udev_db_path);
 290                 return -1;
 291         }
 292
 293         while (1) {
 294                 struct dirent *ent;
 295                 char filename[PATH_SIZE] = "/";
 296                 size_t end, i;
 297
 298                 ent = readdir(dir);
 299                 if (ent == NULL || ent->d_name[0] == '\0')
 300                         break;
 301
 302                 if (ent->d_name[0] == '.')
 303                         continue;
 304
 305                 end = strlcat(filename, ent->d_name, sizeof(filename));
 306                 for (i = 1; i < end; i++)
 307                         if (filename[i] == PATH_TO_NAME_CHAR)
 308                                 filename[i] = '/';
 309                 name_list_add(name_list, filename, 1);
 310                 dbg("added '%s'", filename);
 311         }
 312
 313         closedir(dir);
 314         return 0;
 315 }