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                 err("unable to read db file '%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                         strlcpy(udev->devpath, &bufline[2], count-1);
 131                         break;
 132                 case 'N':
 133                         if (count > sizeof(udev->name))
 134                                 count = sizeof(udev->name);
 135                         strlcpy(udev->name, &bufline[2], count-1);
 136                         break;
 137                 case 'M':
 138                         if (count > sizeof(line))
 139                                 count = sizeof(line);
 140                         strlcpy(line, &bufline[2], count-1);
 141                         sscanf(line, "%u:%u", &major, &minor);
 142                         udev->devt = makedev(major, minor);
 143                         break;
 144                 case 'S':
 145                         if (count > sizeof(line))
 146                                 count =  sizeof(line);
 147                         strlcpy(line, &bufline[2], count-1);
 148                         name_list_add(&udev->symlink_list, line, 0);
 149                         break;
 150                 case 'A':
 151                         if (count > sizeof(line))
 152                                 count =  sizeof(line);
 153                         strlcpy(line, &bufline[2], count-1);
 154                         udev->partitions = atoi(line);
 155                         break;
 156                 case 'R':
 157                         if (count > sizeof(line))
 158                                 count =  sizeof(line);
 159                         strlcpy(line, &bufline[2], count-1);
 160                         udev->ignore_remove = atoi(line);
 161                         break;
 162                 case 'E':
 163                         if (count > sizeof(line))
 164                                 count =  sizeof(line);
 165                         strlcpy(line, &bufline[2], count-1);
 166                         name_list_add(&udev->env_list, line, 0);
 167                         break;
 168                 }
 169         }
 170         file_unmap(buf, bufsize);
 171
 172         if (udev->name[0] == '\0')
 173                 return -1;
 174
 175         return 0;
 176 }
 177
 178 int udev_db_delete_device(struct udevice *udev)
 179 {
 180         char filename[PATH_SIZE];
 181
 182         get_db_filename(udev->devpath, filename, sizeof(filename));
 183         unlink(filename);
 184
 185         return 0;
 186 }
 187
 188 int udev_db_get_device(struct udevice *udev, const char *devpath)
 189 {
 190         char filename[PATH_SIZE];
 191
 192         get_db_filename(devpath, filename, sizeof(filename));
 193
 194         if (parse_db_file(udev, filename) != 0)
 195                 return -1;
 196
 197         return 0;
 198 }
 199
 200 int udev_db_search_name(char *devpath, size_t len, const char *name)
 201 {
 202         DIR *dir;
 203
 204         dir = opendir(udev_db_path);
 205         if (dir == NULL) {
 206                 err("unable to open udev_db '%s'", udev_db_path);
 207                 return -1;
 208         }
 209
 210         while (1) {
 211                 struct dirent *ent;
 212                 char filename[PATH_SIZE];
 213                 char path[PATH_SIZE];
 214                 char nodename[PATH_SIZE];
 215                 char *bufline;
 216                 char *buf;
 217                 size_t bufsize;
 218                 size_t cur;
 219                 size_t count;
 220
 221                 ent = readdir(dir);
 222                 if (ent == NULL || ent->d_name[0] == '\0')
 223                         break;
 224
 225                 if (ent->d_name[0] == '.')
 226                         continue;
 227
 228                 snprintf(filename, sizeof(filename), "%s/%s", udev_db_path, ent->d_name);
 229                 filename[sizeof(filename)-1] = '\0';
 230                 dbg("looking at '%s'", filename);
 231
 232                 if (file_map(filename, &buf, &bufsize) != 0) {
 233                         err("unable to read db file '%s'", filename);
 234                         continue;
 235                 }
 236
 237                 cur = 0;
 238                 while (cur < bufsize) {
 239                         count = buf_get_line(buf, bufsize, cur);
 240                         bufline = &buf[cur];
 241                         cur += count+1;
 242
 243                         switch(bufline[0]) {
 244                         case 'P':
 245                                 if (count > sizeof(path))
 246                                         count = sizeof(path);
 247                                 strlcpy(path, &bufline[2], count-1);
 248                                 break;
 249                         case 'N':
 250                         case 'S':
 251                                 if (count > sizeof(nodename))
 252                                         count = sizeof(nodename);
 253                                 strlcpy(nodename, &bufline[2], count-1);
 254                                 dbg("compare '%s' '%s'", nodename, name);
 255                                 if (strcmp(nodename, name) == 0) {
 256                                         strlcpy(devpath, path, len);
 257                                         file_unmap(buf, bufsize);
 258                                         closedir(dir);
 259                                         return 0;
 260                                 }
 261                                 break;
 262                         default:
 263                                 continue;
 264                         }
 265                 }
 266                 file_unmap(buf, bufsize);
 267         }
 268
 269         closedir(dir);
 270         return -1;
 271 }
 272
 273 int udev_db_dump_names(int (*handler_function)(const char *path, const char *name))
 274 {
 275         DIR *dir;
 276
 277         dir = opendir(udev_db_path);
 278         if (dir == NULL) {
 279                 err("unable to open udev_db '%s'", udev_db_path);
 280                 return -1;
 281         }
 282
 283         while (1) {
 284                 struct dirent *ent;
 285                 char filename[PATH_SIZE];
 286                 char path[PATH_SIZE];
 287                 char nodename[PATH_SIZE];
 288                 char *bufline;
 289                 char *buf;
 290                 size_t bufsize;
 291                 size_t cur;
 292                 size_t count;
 293
 294                 ent = readdir(dir);
 295                 if (ent == NULL || ent->d_name[0] == '\0')
 296                         break;
 297
 298                 if (ent->d_name[0] == '.')
 299                         continue;
 300
 301                 snprintf(filename, sizeof(filename), "%s/%s", udev_db_path, ent->d_name);
 302                 filename[sizeof(filename)-1] = '\0';
 303                 dbg("looking at '%s'", filename);
 304
 305                 if (file_map(filename, &buf, &bufsize) != 0) {
 306                         err("unable to read db file '%s'", filename);
 307                         continue;
 308                 }
 309
 310                 path[0] = '\0';
 311                 nodename[0] = '\0';
 312                 cur = 0;
 313                 while (cur < bufsize) {
 314                         count = buf_get_line(buf, bufsize, cur);
 315                         bufline = &buf[cur];
 316                         cur += count+1;
 317
 318                         switch(bufline[0]) {
 319                         case 'P':
 320                                 if (count > sizeof(path))
 321                                         count = sizeof(path);
 322                                 strlcpy(path, &bufline[2], count-1);
 323                                 break;
 324                         case 'N':
 325                                 if (count > sizeof(nodename))
 326                                         count = sizeof(nodename);
 327                                 strlcpy(nodename, &bufline[2], count-1);
 328                                 break;
 329                         default:
 330                                 continue;
 331                         }
 332                 }
 333                 file_unmap(buf, bufsize);
 334
 335                 if (path[0] == '\0' || nodename[0] == '\0')
 336                         continue;
 337
 338                 if (handler_function(path, nodename) != 0)
 339                         break;
 340         }
 341
 342         closedir(dir);
 343         return 0;
 344 }