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 devpath_to_db_path(const char *devpath, char *filename, size_t len)
  43 {
  44         size_t start, end, i;
  45
  46         /* add location of db files */
  47         start = strlcpy(filename, udev_db_path, len);
  48         end = strlcat(filename, devpath, len);
  49         if (end > len)
  50                 end = len;
  51
  52         /* replace '/' to transform path into a filename */
  53         for (i = start+1; i < end; i++)
  54                 if (filename[i] == '/')
  55                         filename[i] = PATH_TO_NAME_CHAR;
  56
  57         return 0;
  58 }
  59
  60 static int db_file_to_devpath(const char *filename, char *devpath, size_t len)
  61 {
  62         size_t end, i;
  63
  64         strlcpy(devpath, "/", len);
  65         end = strlcat(devpath, filename, len);
  66
  67         /* replace PATH_TO_NAME_CHAR to transform name into devpath */
  68         for (i = 1; i < end; i++)
  69                 if (devpath[i] == PATH_TO_NAME_CHAR)
  70                         devpath[i] = '/';
  71
  72         return 0;
  73 }
  74
  75 int udev_db_add_device(struct udevice *udev)
  76 {
  77         char filename[PATH_SIZE];
  78         struct name_entry *name_loop;
  79         FILE *f;
  80
  81         if (udev->test_run)
  82                 return 0;
  83
  84         /* don't write anything if udev created only the node with the
  85          * kernel name without any interesting data to remember
  86          */
  87         if (strcmp(udev->name, udev->kernel_name) == 0 &&
  88             list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
  89             !udev->partitions && !udev->ignore_remove) {
  90                 dbg("nothing interesting to store in udevdb, skip");
  91                 goto exit;
  92         }
  93
  94         devpath_to_db_path(udev->devpath, filename, sizeof(filename));
  95         create_path(filename);
  96         f = fopen(filename, "w");
  97         if (f == NULL) {
  98                 err("unable to create db file '%s'", filename);
  99                 return -1;
 100         }
 101         dbg("storing data for device '%s' in '%s'", udev->devpath, filename);
 102
 103         fprintf(f, "N:%s\n", udev->name);
 104         list_for_each_entry(name_loop, &udev->symlink_list, node)
 105                 fprintf(f, "S:%s\n", name_loop->name);
 106         fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
 107         if (udev->partitions)
 108                 fprintf(f, "A:%u\n", udev->partitions);
 109         if (udev->ignore_remove)
 110                 fprintf(f, "R:%u\n", udev->ignore_remove);
 111         list_for_each_entry(name_loop, &udev->env_list, node)
 112                 fprintf(f, "E:%s\n", name_loop->name);
 113         fclose(f);
 114
 115 exit:
 116         return 0;
 117 }
 118
 119 int udev_db_get_device(struct udevice *udev, const char *devpath)
 120 {
 121         char filename[PATH_SIZE];
 122         char line[PATH_SIZE];
 123         unsigned int major, minor;
 124         char *bufline;
 125         char *buf;
 126         size_t bufsize;
 127         size_t cur;
 128         size_t count;
 129
 130         devpath_to_db_path(devpath, filename, sizeof(filename));
 131         if (file_map(filename, &buf, &bufsize) != 0) {
 132                 dbg("no db file to read '%s'", filename);
 133                 return -1;
 134         }
 135
 136         strlcpy(udev->devpath, devpath, sizeof(udev->devpath));
 137         cur = 0;
 138         while (cur < bufsize) {
 139                 count = buf_get_line(buf, bufsize, cur);
 140                 bufline = &buf[cur];
 141                 cur += count+1;
 142
 143                 switch(bufline[0]) {
 144                 case 'N':
 145                         if (count > sizeof(udev->name))
 146                                 count = sizeof(udev->name);
 147                         memcpy(udev->name, &bufline[2], count-2);
 148                         udev->name[count-2] = '\0';
 149                         break;
 150                 case 'M':
 151                         if (count > sizeof(line))
 152                                 count = sizeof(line);
 153                         memcpy(line, &bufline[2], count-2);
 154                         line[count-2] = '\0';
 155                         sscanf(line, "%u:%u", &major, &minor);
 156                         udev->devt = makedev(major, minor);
 157                         break;
 158                 case 'S':
 159                         if (count > sizeof(line))
 160                                 count =  sizeof(line);
 161                         memcpy(line, &bufline[2], count-2);
 162                         line[count-2] = '\0';
 163                         name_list_add(&udev->symlink_list, line, 0);
 164                         break;
 165                 case 'A':
 166                         if (count > sizeof(line))
 167                                 count =  sizeof(line);
 168                         memcpy(line, &bufline[2], count-2);
 169                         line[count-2] = '\0';
 170                         udev->partitions = atoi(line);
 171                         break;
 172                 case 'R':
 173                         if (count > sizeof(line))
 174                                 count =  sizeof(line);
 175                         memcpy(line, &bufline[2], count-2);
 176                         line[count-2] = '\0';
 177                         udev->ignore_remove = atoi(line);
 178                         break;
 179                 case 'E':
 180                         if (count > sizeof(line))
 181                                 count =  sizeof(line);
 182                         memcpy(line, &bufline[2], count-2);
 183                         line[count-2] = '\0';
 184                         name_list_add(&udev->env_list, line, 0);
 185                         break;
 186                 }
 187         }
 188         file_unmap(buf, bufsize);
 189
 190         if (udev->name[0] == '\0')
 191                 return -1;
 192
 193         return 0;
 194 }
 195
 196 int udev_db_delete_device(struct udevice *udev)
 197 {
 198         char filename[PATH_SIZE];
 199
 200         devpath_to_db_path(udev->devpath, filename, sizeof(filename));
 201         unlink(filename);
 202
 203         return 0;
 204 }
 205
 206 int udev_db_lookup_name(const char *name, char *devpath, size_t len)
 207 {
 208         DIR *dir;
 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                 if (ent->d_name[0] == '.')
 231                         continue;
 232
 233                 snprintf(filename, sizeof(filename), "%s/%s", udev_db_path, ent->d_name);
 234                 filename[sizeof(filename)-1] = '\0';
 235                 dbg("looking at '%s'", filename);
 236
 237                 if (file_map(filename, &buf, &bufsize) != 0) {
 238                         err("unable to read db file '%s'", filename);
 239                         continue;
 240                 }
 241
 242                 cur = 0;
 243                 while (cur < bufsize && !found) {
 244                         count = buf_get_line(buf, bufsize, cur);
 245                         bufline = &buf[cur];
 246                         cur += count+1;
 247
 248                         switch(bufline[0]) {
 249                         case 'N':
 250                         case 'S':
 251                                 if (count > sizeof(nodename))
 252                                         count = sizeof(nodename);
 253                                 memcpy(nodename, &bufline[2], count-2);
 254                                 nodename[count-2] = '\0';
 255                                 dbg("compare '%s' '%s'", nodename, name);
 256                                 if (strcmp(nodename, name) == 0) {
 257                                         db_file_to_devpath(ent->d_name, devpath, len);
 258                                         found = 1;
 259                                 }
 260                                 break;
 261                         default:
 262                                 continue;
 263                         }
 264                 }
 265                 file_unmap(buf, bufsize);
 266         }
 267
 268         closedir(dir);
 269         if (found)
 270                 return 0;
 271         else
 272                 return -1;
 273 }
 274
 275 int udev_db_get_all_entries(struct list_head *name_list)
 276 {
 277         DIR *dir;
 278
 279         dir = opendir(udev_db_path);
 280         if (dir == NULL) {
 281                 err("unable to open udev_db '%s'", udev_db_path);
 282                 return -1;
 283         }
 284
 285         while (1) {
 286                 struct dirent *ent;
 287                 char filename[PATH_SIZE] = "/";
 288                 size_t end, i;
 289
 290                 ent = readdir(dir);
 291                 if (ent == NULL || ent->d_name[0] == '\0')
 292                         break;
 293                 if (ent->d_name[0] == '.')
 294                         continue;
 295
 296                 end = strlcat(filename, ent->d_name, sizeof(filename));
 297                 for (i = 1; i < end; i++)
 298                         if (filename[i] == PATH_TO_NAME_CHAR)
 299                                 filename[i] = '/';
 300                 name_list_add(name_list, filename, 1);
 301                 dbg("added '%s'", filename);
 302         }
 303
 304         closedir(dir);
 305         return 0;
 306 }