udev_db.c

   1 /*
   2  * udev_db.c
   3  *
   4  * Userspace devfs
   5  *
   6  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
   7  * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
   8  *
   9  *      This program is free software; you can redistribute it and/or modify it
  10  *      under the terms of the GNU General Public License as published by the
  11  *      Free Software Foundation version 2 of the License.
  12  *
  13  *      This program is distributed in the hope that it will be useful, but
  14  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *      General Public License for more details.
  17  *
  18  *      You should have received a copy of the GNU General Public License along
  19  *      with this program; if not, write to the Free Software Foundation, Inc.,
  20  *      675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  */
  23
  24
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <stddef.h>
  29 #include <unistd.h>
  30 #include <fcntl.h>
  31 #include <string.h>
  32 #include <errno.h>
  33 #include <dirent.h>
  34
  35 #include "libsysfs/sysfs/libsysfs.h"
  36 #include "udev_libc_wrapper.h"
  37 #include "udev.h"
  38 #include "udev_utils.h"
  39 #include "logging.h"
  40 #include "udev_db.h"
  41
  42 #define PATH_TO_NAME_CHAR               '@'
  43
  44 static int get_db_filename(const char *devpath, char *filename, int len)
  45 {
  46         char temp[PATH_SIZE];
  47         char *pos;
  48
  49         /* replace '/' to transform path into a filename */
  50         strlcpy(temp, devpath, sizeof(temp));
  51         pos = strchr(&temp[1], '/');
  52         while (pos) {
  53                 pos[0] = PATH_TO_NAME_CHAR;
  54                 pos = strchr(&pos[1], '/');
  55         }
  56         snprintf(filename, len, "%s%s", udev_db_path, temp);
  57         filename[len-1] = '\0';
  58
  59         return 0;
  60 }
  61
  62 int udev_db_add_device(struct udevice *udev)
  63 {
  64         char filename[PATH_SIZE];
  65         struct name_entry *name_loop;
  66         FILE *f;
  67
  68         if (udev->test_run)
  69                 return 0;
  70
  71         /* don't write anything if udev created only the node with the
  72          * kernel name without any interesting data to remember
  73          */
  74         if (strcmp(udev->name, udev->kernel_name) == 0 &&
  75             list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
  76             !udev->partitions && !udev->ignore_remove) {
  77                 dbg("nothing interesting to store in udevdb, skip");
  78                 goto exit;
  79         }
  80
  81         get_db_filename(udev->devpath, filename, sizeof(filename));
  82         create_path(filename);
  83         f = fopen(filename, "w");
  84         if (f == NULL) {
  85                 err("unable to create db file '%s'", filename);
  86                 return -1;
  87         }
  88         dbg("storing data for device '%s' in '%s'", udev->devpath, filename);
  89
  90         fprintf(f, "P:%s\n", udev->devpath);
  91         fprintf(f, "N:%s\n", udev->name);
  92         list_for_each_entry(name_loop, &udev->symlink_list, node)
  93                 fprintf(f, "S:%s\n", name_loop->name);
  94         fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
  95         if (udev->partitions)
  96                 fprintf(f, "A:%u\n", udev->partitions);
  97         if (udev->ignore_remove)
  98                 fprintf(f, "R:%u\n", udev->ignore_remove);
  99         list_for_each_entry(name_loop, &udev->env_list, node)
 100                 fprintf(f, "E:%s\n", name_loop->name);
 101         fclose(f);
 102
 103 exit:
 104         return 0;
 105 }
 106
 107 static int parse_db_file(struct udevice *udev, const char *filename)
 108 {
 109         char line[PATH_SIZE];
 110         unsigned int major, minor;
 111         char *bufline;
 112         char *buf;
 113         size_t bufsize;
 114         size_t cur;
 115         size_t count;
 116
 117         if (file_map(filename, &buf, &bufsize) != 0) {
 118                 err("unable to read db file '%s'", filename);
 119                 return -1;
 120         }
 121
 122         cur = 0;
 123         while (cur < bufsize) {
 124                 count = buf_get_line(buf, bufsize, cur);
 125                 bufline = &buf[cur];
 126                 cur += count+1;
 127
 128                 switch(bufline[0]) {
 129                 case 'P':
 130                         if (count > sizeof(udev->devpath))
 131                                 count = sizeof(udev->devpath);
 132                         strlcpy(udev->devpath, &bufline[2], count-1);
 133                         break;
 134                 case 'N':
 135                         if (count > sizeof(udev->name))
 136                                 count = sizeof(udev->name);
 137                         strlcpy(udev->name, &bufline[2], count-1);
 138                         break;
 139                 case 'M':
 140                         if (count > sizeof(line))
 141                                 count = sizeof(line);
 142                         strlcpy(line, &bufline[2], count-1);
 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                         strlcpy(line, &bufline[2], count-1);
 150                         name_list_add(&udev->symlink_list, line, 0);
 151                         break;
 152                 case 'A':
 153                         if (count > sizeof(line))
 154                                 count =  sizeof(line);
 155                         strlcpy(line, &bufline[2], count-1);
 156                         udev->partitions = atoi(line);
 157                         break;
 158                 case 'R':
 159                         if (count > sizeof(line))
 160                                 count =  sizeof(line);
 161                         strlcpy(line, &bufline[2], count-1);
 162                         udev->ignore_remove = atoi(line);
 163                         break;
 164                 case 'E':
 165                         if (count > sizeof(line))
 166                                 count =  sizeof(line);
 167                         strlcpy(line, &bufline[2], count-1);
 168                         name_list_add(&udev->env_list, line, 0);
 169                         break;
 170                 }
 171         }
 172         file_unmap(buf, bufsize);
 173
 174         if (udev->name[0] == '\0')
 175                 return -1;
 176
 177         return 0;
 178 }
 179
 180 int udev_db_delete_device(struct udevice *udev)
 181 {
 182         char filename[PATH_SIZE];
 183
 184         get_db_filename(udev->devpath, filename, sizeof(filename));
 185         unlink(filename);
 186
 187         return 0;
 188 }
 189
 190 int udev_db_get_device(struct udevice *udev, const char *devpath)
 191 {
 192         char filename[PATH_SIZE];
 193
 194         get_db_filename(devpath, filename, sizeof(filename));
 195
 196         if (parse_db_file(udev, filename) != 0)
 197                 return -1;
 198
 199         return 0;
 200 }
 201
 202 int udev_db_search_name(char *devpath, size_t len, const char *name)
 203 {
 204         DIR *dir;
 205
 206         dir = opendir(udev_db_path);
 207         if (dir == NULL) {
 208                 err("unable to open udev_db '%s'", udev_db_path);
 209                 return -1;
 210         }
 211
 212         while (1) {
 213                 struct dirent *ent;
 214                 char filename[PATH_SIZE];
 215                 char path[PATH_SIZE];
 216                 char nodename[PATH_SIZE];
 217                 char *bufline;
 218                 char *buf;
 219                 size_t bufsize;
 220                 size_t cur;
 221                 size_t count;
 222
 223                 ent = readdir(dir);
 224                 if (ent == NULL || ent->d_name[0] == '\0')
 225                         break;
 226
 227                 if (ent->d_name[0] == '.')
 228                         continue;
 229
 230                 snprintf(filename, sizeof(filename), "%s/%s", udev_db_path, ent->d_name);
 231                 filename[sizeof(filename)-1] = '\0';
 232                 dbg("looking at '%s'", filename);
 233
 234                 if (file_map(filename, &buf, &bufsize) != 0) {
 235                         err("unable to read db file '%s'", filename);
 236                         continue;
 237                 }
 238
 239                 cur = 0;
 240                 while (cur < bufsize) {
 241                         count = buf_get_line(buf, bufsize, cur);
 242                         bufline = &buf[cur];
 243                         cur += count+1;
 244
 245                         switch(bufline[0]) {
 246                         case 'P':
 247                                 if (count > sizeof(path))
 248                                         count = sizeof(path);
 249                                 strlcpy(path, &bufline[2], count-1);
 250                                 break;
 251                         case 'N':
 252                         case 'S':
 253                                 if (count > sizeof(nodename))
 254                                         count = sizeof(nodename);
 255                                 strlcpy(nodename, &bufline[2], count-1);
 256                                 dbg("compare '%s' '%s'", nodename, name);
 257                                 if (strcmp(nodename, name) == 0) {
 258                                         strlcpy(devpath, path, len);
 259                                         file_unmap(buf, bufsize);
 260                                         closedir(dir);
 261                                         return 0;
 262                                 }
 263                                 break;
 264                         default:
 265                                 continue;
 266                         }
 267                 }
 268                 file_unmap(buf, bufsize);
 269         }
 270
 271         closedir(dir);
 272         return -1;
 273 }
 274
 275 int udev_db_dump_names(int (*handler_function)(const char *path, const char *name))
 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                 char path[PATH_SIZE];
 289                 char nodename[PATH_SIZE];
 290                 char *bufline;
 291                 char *buf;
 292                 size_t bufsize;
 293                 size_t cur;
 294                 size_t count;
 295
 296                 ent = readdir(dir);
 297                 if (ent == NULL || ent->d_name[0] == '\0')
 298                         break;
 299
 300                 if (ent->d_name[0] == '.')
 301                         continue;
 302
 303                 snprintf(filename, sizeof(filename), "%s/%s", udev_db_path, ent->d_name);
 304                 filename[sizeof(filename)-1] = '\0';
 305                 dbg("looking at '%s'", filename);
 306
 307                 if (file_map(filename, &buf, &bufsize) != 0) {
 308                         err("unable to read db file '%s'", filename);
 309                         continue;
 310                 }
 311
 312                 path[0] = '\0';
 313                 nodename[0] = '\0';
 314                 cur = 0;
 315                 while (cur < bufsize) {
 316                         count = buf_get_line(buf, bufsize, cur);
 317                         bufline = &buf[cur];
 318                         cur += count+1;
 319
 320                         switch(bufline[0]) {
 321                         case 'P':
 322                                 if (count > sizeof(path))
 323                                         count = sizeof(path);
 324                                 strlcpy(path, &bufline[2], count-1);
 325                                 break;
 326                         case 'N':
 327                                 if (count > sizeof(nodename))
 328                                         count = sizeof(nodename);
 329                                 strlcpy(nodename, &bufline[2], count-1);
 330                                 break;
 331                         default:
 332                                 continue;
 333                         }
 334                 }
 335                 file_unmap(buf, bufsize);
 336
 337                 if (path[0] == '\0' || nodename[0] == '\0')
 338                         continue;
 339
 340                 if (handler_function(path, nodename) != 0)
 341                         break;
 342         }
 343
 344         closedir(dir);
 345         return 0;
 346 }