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
  39
  40 static int devpath_to_db_path(const char *devpath, char *filename, size_t len)
  41 {
  42         size_t start, end, i;
  43
  44         /* add location of db files */
  45         strlcpy(filename, udev_root, len);
  46         start = strlcat(filename, "/"DB_DIR, 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 static int db_file_to_devpath(const char *filename, char *devpath, size_t len)
  60 {
  61         size_t end, i;
  62
  63         strlcpy(devpath, "/", len);
  64         end = strlcat(devpath, filename, len);
  65
  66         /* replace PATH_TO_NAME_CHAR to transform name into devpath */
  67         for (i = 1; i < end; i++)
  68                 if (devpath[i] == PATH_TO_NAME_CHAR)
  69                         devpath[i] = '/';
  70
  71         return 0;
  72 }
  73
  74 int udev_db_add_device(struct udevice *udev)
  75 {
  76         char filename[PATH_SIZE];
  77         struct name_entry *name_loop;
  78         FILE *f;
  79
  80         if (udev->test_run)
  81                 return 0;
  82
  83         /* don't write anything if udev created only the node with the
  84          * kernel name without any interesting data to remember
  85          */
  86         if (strcmp(udev->name, udev->kernel_name) == 0 &&
  87             list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
  88             !udev->partitions && !udev->ignore_remove) {
  89                 dbg("nothing interesting to store in udevdb, skip");
  90                 goto exit;
  91         }
  92
  93         devpath_to_db_path(udev->devpath, filename, sizeof(filename));
  94         create_path(filename);
  95         f = fopen(filename, "w");
  96         if (f == NULL) {
  97                 err("unable to create db file '%s': %s", filename, strerror(errno));
  98                 return -1;
  99         }
 100         dbg("storing data for device '%s' in '%s'", udev->devpath, filename);
 101
 102         fprintf(f, "N:%s\n", udev->name);
 103         list_for_each_entry(name_loop, &udev->symlink_list, node)
 104                 fprintf(f, "S:%s\n", name_loop->name);
 105         fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
 106         if (udev->partitions)
 107                 fprintf(f, "A:%u\n", udev->partitions);
 108         if (udev->ignore_remove)
 109                 fprintf(f, "R:%u\n", udev->ignore_remove);
 110         list_for_each_entry(name_loop, &udev->env_list, node)
 111                 fprintf(f, "E:%s\n", name_loop->name);
 112         fclose(f);
 113
 114 exit:
 115         return 0;
 116 }
 117
 118 int udev_db_get_device(struct udevice *udev, const char *devpath)
 119 {
 120         char filename[PATH_SIZE];
 121         char line[PATH_SIZE];
 122         unsigned int major, minor;
 123         char *bufline;
 124         char *buf;
 125         size_t bufsize;
 126         size_t cur;
 127         size_t count;
 128
 129         devpath_to_db_path(devpath, filename, sizeof(filename));
 130         if (file_map(filename, &buf, &bufsize) != 0) {
 131                 info("no db file to read %s: %s", filename, strerror(errno));
 132                 return -1;
 133         }
 134
 135         strlcpy(udev->devpath, devpath, sizeof(udev->devpath));
 136         cur = 0;
 137         while (cur < bufsize) {
 138                 count = buf_get_line(buf, bufsize, cur);
 139                 bufline = &buf[cur];
 140                 cur += count+1;
 141
 142                 switch(bufline[0]) {
 143                 case 'N':
 144                         if (count > sizeof(udev->name))
 145                                 count = sizeof(udev->name);
 146                         memcpy(udev->name, &bufline[2], count-2);
 147                         udev->name[count-2] = '\0';
 148                         break;
 149                 case 'M':
 150                         if (count > sizeof(line))
 151                                 count = sizeof(line);
 152                         memcpy(line, &bufline[2], count-2);
 153                         line[count-2] = '\0';
 154                         sscanf(line, "%u:%u", &major, &minor);
 155                         udev->devt = makedev(major, minor);
 156                         break;
 157                 case 'S':
 158                         if (count > sizeof(line))
 159                                 count =  sizeof(line);
 160                         memcpy(line, &bufline[2], count-2);
 161                         line[count-2] = '\0';
 162                         name_list_add(&udev->symlink_list, line, 0);
 163                         break;
 164                 case 'A':
 165                         if (count > sizeof(line))
 166                                 count =  sizeof(line);
 167                         memcpy(line, &bufline[2], count-2);
 168                         line[count-2] = '\0';
 169                         udev->partitions = atoi(line);
 170                         break;
 171                 case 'R':
 172                         if (count > sizeof(line))
 173                                 count =  sizeof(line);
 174                         memcpy(line, &bufline[2], count-2);
 175                         line[count-2] = '\0';
 176                         udev->ignore_remove = atoi(line);
 177                         break;
 178                 case 'E':
 179                         if (count > sizeof(line))
 180                                 count =  sizeof(line);
 181                         memcpy(line, &bufline[2], count-2);
 182                         line[count-2] = '\0';
 183                         name_list_add(&udev->env_list, line, 0);
 184                         break;
 185                 }
 186         }
 187         file_unmap(buf, bufsize);
 188
 189         if (udev->name[0] == '\0')
 190                 return -1;
 191
 192         return 0;
 193 }
 194
 195 int udev_db_delete_device(struct udevice *udev)
 196 {
 197         char filename[PATH_SIZE];
 198
 199         devpath_to_db_path(udev->devpath, filename, sizeof(filename));
 200         unlink(filename);
 201
 202         return 0;
 203 }
 204
 205 int udev_db_lookup_name(const char *name, char *devpath, size_t len)
 206 {
 207         char dbpath[PATH_MAX];
 208         DIR *dir;
 209         int found = 0;
 210
 211         strlcpy(dbpath, udev_root, sizeof(dbpath));
 212         strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 213         dir = opendir(dbpath);
 214         if (dir == NULL) {
 215                 info("no udev_db available '%s': %s", dbpath, strerror(errno));
 216                 return -1;
 217         }
 218
 219         while (!found) {
 220                 struct dirent *ent;
 221                 char filename[PATH_SIZE];
 222                 char nodename[PATH_SIZE];
 223                 char *bufline;
 224                 char *buf;
 225                 size_t bufsize;
 226                 size_t cur;
 227                 size_t count;
 228
 229                 ent = readdir(dir);
 230                 if (ent == NULL || ent->d_name[0] == '\0')
 231                         break;
 232                 if (ent->d_name[0] == '.')
 233                         continue;
 234
 235                 snprintf(filename, sizeof(filename), "%s/%s", dbpath, 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': %s", filename, strerror(errno));
 241                         continue;
 242                 }
 243
 244                 cur = 0;
 245                 while (cur < bufsize && !found) {
 246                         count = buf_get_line(buf, bufsize, cur);
 247                         bufline = &buf[cur];
 248                         cur += count+1;
 249
 250                         switch(bufline[0]) {
 251                         case 'N':
 252                         case 'S':
 253                                 if (count > sizeof(nodename))
 254                                         count = sizeof(nodename);
 255                                 memcpy(nodename, &bufline[2], count-2);
 256                                 nodename[count-2] = '\0';
 257                                 dbg("compare '%s' '%s'", nodename, name);
 258                                 if (strcmp(nodename, name) == 0) {
 259                                         db_file_to_devpath(ent->d_name, devpath, len);
 260                                         found = 1;
 261                                 }
 262                                 break;
 263                         default:
 264                                 continue;
 265                         }
 266                 }
 267                 file_unmap(buf, bufsize);
 268         }
 269
 270         closedir(dir);
 271         if (found)
 272                 return 0;
 273         else
 274                 return -1;
 275 }
 276
 277 int udev_db_get_all_entries(struct list_head *name_list)
 278 {
 279         char dbpath[PATH_MAX];
 280         DIR *dir;
 281
 282         strlcpy(dbpath, udev_root, sizeof(dbpath));
 283         strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
 284         dir = opendir(dbpath);
 285         if (dir == NULL) {
 286                 info("no udev_db available '%s': %s", dbpath, strerror(errno));
 287                 return -1;
 288         }
 289
 290         while (1) {
 291                 struct dirent *ent;
 292                 char filename[PATH_SIZE] = "/";
 293                 size_t end, i;
 294
 295                 ent = readdir(dir);
 296                 if (ent == NULL || ent->d_name[0] == '\0')
 297                         break;
 298                 if (ent->d_name[0] == '.')
 299                         continue;
 300
 301                 end = strlcat(filename, ent->d_name, sizeof(filename));
 302                 for (i = 1; i < end; i++)
 303                         if (filename[i] == PATH_TO_NAME_CHAR)
 304                                 filename[i] = '/';
 305                 name_list_add(name_list, filename, 1);
 306                 dbg("added '%s'", filename);
 307         }
 308
 309         closedir(dir);
 310         return 0;
 311 }