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, int len)
  43 {
  44         char temp[PATH_SIZE];
  45         char *pos;
  46
  47         /* replace '/' to transform path into a filename */
  48         strlcpy(temp, devpath, sizeof(temp));
  49         pos = strchr(&temp[1], '/');
  50         while (pos) {
  51                 pos[0] = PATH_TO_NAME_CHAR;
  52                 pos = strchr(&pos[1], '/');
  53         }
  54         snprintf(filename, len, "%s%s", udev_db_path, temp);
  55         filename[len-1] = '\0';
  56
  57         return 0;
  58 }
  59
  60 int udev_db_add_device(struct udevice *udev)
  61 {
  62         char filename[PATH_SIZE];
  63         struct name_entry *name_loop;
  64         FILE *f;
  65
  66         if (udev->test_run)
  67                 return 0;
  68
  69         /* don't write anything if udev created only the node with the
  70          * kernel name without any interesting data to remember
  71          */
  72         if (strcmp(udev->name, udev->kernel_name) == 0 &&
  73             list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
  74             !udev->partitions && !udev->ignore_remove) {
  75                 dbg("nothing interesting to store in udevdb, skip");
  76                 goto exit;
  77         }
  78
  79         get_db_filename(udev->devpath, filename, sizeof(filename));
  80         create_path(filename);
  81         f = fopen(filename, "w");
  82         if (f == NULL) {
  83                 err("unable to create db file '%s'", filename);
  84                 return -1;
  85         }
  86         dbg("storing data for device '%s' in '%s'", udev->devpath, filename);
  87
  88         fprintf(f, "P:%s\n", udev->devpath);
  89         fprintf(f, "N:%s\n", udev->name);
  90         list_for_each_entry(name_loop, &udev->symlink_list, node)
  91                 fprintf(f, "S:%s\n", name_loop->name);
  92         fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
  93         if (udev->partitions)
  94                 fprintf(f, "A:%u\n", udev->partitions);
  95         if (udev->ignore_remove)
  96                 fprintf(f, "R:%u\n", udev->ignore_remove);
  97         list_for_each_entry(name_loop, &udev->env_list, node)
  98                 fprintf(f, "E:%s\n", name_loop->name);
  99         fclose(f);
 100
 101 exit:
 102         return 0;
 103 }
 104
 105 static int parse_db_file(struct udevice *udev, const char *filename)
 106 {
 107         char line[PATH_SIZE];
 108         unsigned int major, minor;
 109         char *bufline;
 110         char *buf;
 111         size_t bufsize;
 112         size_t cur;
 113         size_t count;
 114
 115         if (file_map(filename, &buf, &bufsize) != 0) {
 116                 dbg("no db file to read '%s'", filename);
 117                 return -1;
 118         }
 119
 120         cur = 0;
 121         while (cur < bufsize) {
 122                 count = buf_get_line(buf, bufsize, cur);
 123                 bufline = &buf[cur];
 124                 cur += count+1;
 125
 126                 switch(bufline[0]) {
 127                 case 'P':
 128                         if (count > sizeof(udev->devpath))
 129                                 count = sizeof(udev->devpath);
 130                         memcpy(udev->devpath, &bufline[2], count-2);
 131                         udev->devpath[count-2] = '\0';
 132                         break;
 133                 case 'N':
 134                         if (count > sizeof(udev->name))
 135                                 count = sizeof(udev->name);
 136                         memcpy(udev->name, &bufline[2], count-2);
 137                         udev->name[count-2] = '\0';
 138                         break;
 139                 case 'M':
 140                         if (count > sizeof(line))
 141                                 count = sizeof(line);
 142                         memcpy(line, &bufline[2], count-2);
 143                         line[count-2] = '\0';
 144                         sscanf(line, "%u:%u", &major, &minor);
 145                         udev->devt = makedev(major, minor);
 146                         break;
 147                 case 'S':
 148                         if (count > sizeof(line))
 149                                 count =  sizeof(line);
 150                         memcpy(line, &bufline[2], count-2);
 151                         line[count-2] = '\0';
 152                         name_list_add(&udev->symlink_list, line, 0);
 153                         break;
 154                 case 'A':
 155                         if (count > sizeof(line))
 156                                 count =  sizeof(line);
 157                         memcpy(line, &bufline[2], count-2);
 158                         line[count-2] = '\0';
 159                         udev->partitions = atoi(line);
 160                         break;
 161                 case 'R':
 162                         if (count > sizeof(line))
 163                                 count =  sizeof(line);
 164                         memcpy(line, &bufline[2], count-2);
 165                         line[count-2] = '\0';
 166                         udev->ignore_remove = atoi(line);
 167                         break;
 168                 case 'E':
 169                         if (count > sizeof(line))
 170                                 count =  sizeof(line);
 171                         memcpy(line, &bufline[2], count-2);
 172                         line[count-2] = '\0';
 173                         name_list_add(&udev->env_list, line, 0);
 174                         break;
 175                 }
 176         }
 177         file_unmap(buf, bufsize);
 178
 179         if (udev->name[0] == '\0')
 180                 return -1;
 181
 182         return 0;
 183 }
 184
 185 int udev_db_delete_device(struct udevice *udev)
 186 {
 187         char filename[PATH_SIZE];
 188
 189         get_db_filename(udev->devpath, filename, sizeof(filename));
 190         unlink(filename);
 191
 192         return 0;
 193 }
 194
 195 int udev_db_get_device(struct udevice *udev, const char *devpath)
 196 {
 197         char filename[PATH_SIZE];
 198
 199         get_db_filename(devpath, filename, sizeof(filename));
 200
 201         if (parse_db_file(udev, filename) != 0)
 202                 return -1;
 203
 204         return 0;
 205 }
 206
 207 int udev_db_search_name(char *devpath, size_t len, const char *name)
 208 {
 209         DIR *dir;
 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 (1) {
 218                 struct dirent *ent;
 219                 char filename[PATH_SIZE];
 220                 char path[PATH_SIZE];
 221                 char nodename[PATH_SIZE];
 222                 char *bufline;
 223                 char *buf;
 224                 size_t bufsize;
 225                 size_t cur;
 226                 size_t count;
 227
 228                 ent = readdir(dir);
 229                 if (ent == NULL || ent->d_name[0] == '\0')
 230                         break;
 231
 232                 if (ent->d_name[0] == '.')
 233                         continue;
 234
 235                 snprintf(filename, sizeof(filename), "%s/%s", udev_db_path, ent->d_name);
 236                 filename[sizeof(filename)-1] = '\0';
 237                 dbg("looking at '%s'", filename);
 238
 239                 if (file_map(filename, &buf, &bufsize) != 0) {
 240                         err("unable to read db file '%s'", filename);
 241                         continue;
 242                 }
 243
 244                 cur = 0;
 245                 while (cur < bufsize) {
 246                         count = buf_get_line(buf, bufsize, cur);
 247                         bufline = &buf[cur];
 248                         cur += count+1;
 249
 250                         switch(bufline[0]) {
 251                         case 'P':
 252                                 if (count > sizeof(path))
 253                                         count = sizeof(path);
 254                                 memcpy(path, &bufline[2], count-2);
 255                                 path[count-2] = '\0';
 256                                 break;
 257                         case 'N':
 258                         case 'S':
 259                                 if (count > sizeof(nodename))
 260                                         count = sizeof(nodename);
 261                                 memcpy(nodename, &bufline[2], count-2);
 262                                 nodename[count-2] = '\0';
 263                                 dbg("compare '%s' '%s'", nodename, name);
 264                                 if (strcmp(nodename, name) == 0) {
 265                                         strlcpy(devpath, nodename, len);
 266                                         devpath[count-2] = '\0';
 267                                         file_unmap(buf, bufsize);
 268                                         closedir(dir);
 269                                         return 0;
 270                                 }
 271                                 break;
 272                         default:
 273                                 continue;
 274                         }
 275                 }
 276                 file_unmap(buf, bufsize);
 277         }
 278
 279         closedir(dir);
 280         return -1;
 281 }
 282
 283 int udev_db_dump_names(int (*handler_function)(const char *path, const char *name))
 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                 char path[PATH_SIZE];
 297                 char nodename[PATH_SIZE];
 298                 char *bufline;
 299                 char *buf;
 300                 size_t bufsize;
 301                 size_t cur;
 302                 size_t count;
 303
 304                 ent = readdir(dir);
 305                 if (ent == NULL || ent->d_name[0] == '\0')
 306                         break;
 307
 308                 if (ent->d_name[0] == '.')
 309                         continue;
 310
 311                 snprintf(filename, sizeof(filename), "%s/%s", udev_db_path, ent->d_name);
 312                 filename[sizeof(filename)-1] = '\0';
 313                 dbg("looking at '%s'", filename);
 314
 315                 if (file_map(filename, &buf, &bufsize) != 0) {
 316                         err("unable to read db file '%s'", filename);
 317                         continue;
 318                 }
 319
 320                 path[0] = '\0';
 321                 nodename[0] = '\0';
 322                 cur = 0;
 323                 while (cur < bufsize) {
 324                         count = buf_get_line(buf, bufsize, cur);
 325                         bufline = &buf[cur];
 326                         cur += count+1;
 327
 328                         switch(bufline[0]) {
 329                         case 'P':
 330                                 if (count > sizeof(path))
 331                                         count = sizeof(path);
 332                                 memcpy(path, &bufline[2], count-2);
 333                                 path[count-2] = '\0';
 334                                 break;
 335                         case 'N':
 336                                 if (count > sizeof(nodename))
 337                                         count = sizeof(nodename);
 338                                 memcpy(nodename, &bufline[2], count-2);
 339                                 nodename[count-2] = '\0';
 340                                 break;
 341                         default:
 342                                 continue;
 343                         }
 344                 }
 345                 file_unmap(buf, bufsize);
 346
 347                 if (path[0] == '\0' || nodename[0] == '\0')
 348                         continue;
 349
 350                 if (handler_function(path, nodename) != 0)
 351                         break;
 352         }
 353
 354         closedir(dir);
 355         return 0;
 356 }