udev/lib/libudev-device-db-write.c

   1 /*
   2  * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <stdlib.h>
  19 #include <stdio.h>
  20 #include <string.h>
  21 #include <stddef.h>
  22 #include <unistd.h>
  23 #include <fcntl.h>
  24 #include <string.h>
  25 #include <sys/stat.h>
  26
  27 #include "udev.h"
  28
  29 static size_t devpath_to_db_path(struct udev *udev, const char *devpath, char *filename, size_t len)
  30 {
  31         size_t start;
  32
  33         /* translate to location of db file */
  34         util_strlcpy(filename, udev_get_dev_path(udev), len);
  35         start = util_strlcat(filename, "/.udev/db/", len);
  36         util_strlcat(filename, devpath, len);
  37         return util_path_encode(&filename[start], len - start);
  38 }
  39
  40 int udev_device_update_db(struct udev_device *udev_device)
  41 {
  42         struct udev *udev = udev_device_get_udev(udev_device);
  43         char filename[UTIL_PATH_SIZE];
  44         FILE *f;
  45         char target[232]; /* on 64bit, tmpfs inlines up to 239 bytes */
  46         size_t devlen = strlen(udev_get_dev_path(udev))+1;
  47         struct udev_list_entry *list_entry;
  48         int ret;
  49
  50         devpath_to_db_path(udev,
  51                            udev_device_get_devpath(udev_device),
  52                            filename, sizeof(filename));
  53         util_create_path(udev, filename);
  54         unlink(filename);
  55
  56         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device))
  57                 if (udev_list_entry_get_flag(list_entry))
  58                         goto file;
  59         if (udev_device_get_num_fake_partitions(udev_device) != 0)
  60                 goto file;
  61         if (udev_device_get_ignore_remove(udev_device))
  62                 goto file;
  63         if (udev_device_get_devlink_priority(udev_device) != 0)
  64                 goto file;
  65         if (udev_device_get_event_timeout(udev_device) >= 0)
  66                 goto file;
  67         if (udev_device_get_devnode(udev_device) == NULL)
  68                 goto out;
  69
  70         /*
  71          * if we have only the node and symlinks to store, try not to waste
  72          * tmpfs memory -- store values, if they fit, in a symlink target
  73          */
  74         util_strlcpy(target, &udev_device_get_devnode(udev_device)[devlen], sizeof(target));
  75         udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device)) {
  76                 size_t len;
  77
  78                 util_strlcat(target, " ", sizeof(target));
  79                 len = util_strlcat(target, &udev_list_entry_get_name(list_entry)[devlen], sizeof(target));
  80                 if (len >= sizeof(target)) {
  81                         info(udev, "size of links too large, create file\n");
  82                         goto file;
  83                 }
  84         }
  85         info(udev, "create db link (%s)\n", target);
  86         udev_selinux_setfscreatecon(udev, filename, S_IFLNK);
  87         ret = symlink(target, filename);
  88         udev_selinux_resetfscreatecon(udev);
  89         if (ret == 0)
  90                 goto out;
  91 file:
  92         f = fopen(filename, "w");
  93         if (f == NULL) {
  94                 err(udev, "unable to create db file '%s': %m\n", filename);
  95                 return -1;
  96                 }
  97         info(udev, "created db file for '%s' in '%s'\n", udev_device_get_devpath(udev_device), filename);
  98
  99         if (udev_device_get_devnode(udev_device) != NULL) {
 100                 fprintf(f, "N:%s\n", &udev_device_get_devnode(udev_device)[devlen]);
 101                 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device))
 102                         fprintf(f, "S:%s\n", &udev_list_entry_get_name(list_entry)[devlen]);
 103         }
 104         if (udev_device_get_devlink_priority(udev_device) != 0)
 105                 fprintf(f, "L:%u\n", udev_device_get_devlink_priority(udev_device));
 106         if (udev_device_get_event_timeout(udev_device) >= 0)
 107                 fprintf(f, "T:%u\n", udev_device_get_event_timeout(udev_device));
 108         if (udev_device_get_num_fake_partitions(udev_device) != 0)
 109                 fprintf(f, "A:%u\n", udev_device_get_num_fake_partitions(udev_device));
 110         if (udev_device_get_ignore_remove(udev_device))
 111                 fprintf(f, "R:%u\n", udev_device_get_ignore_remove(udev_device));
 112         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
 113                 if (!udev_list_entry_get_flag(list_entry))
 114                         continue;
 115                 fprintf(f, "E:%s=%s\n",
 116                         udev_list_entry_get_name(list_entry),
 117                         udev_list_entry_get_value(list_entry));
 118         }
 119         fclose(f);
 120 out:
 121         return 0;
 122 }
 123
 124 int udev_device_delete_db(struct udev_device *udev_device)
 125 {
 126         char filename[UTIL_PATH_SIZE];
 127
 128         devpath_to_db_path(udev_device_get_udev(udev_device),
 129                            udev_device_get_devpath(udev_device),
 130                            filename, sizeof(filename));
 131         unlink(filename);
 132         return 0;
 133 }
 134
 135 int udev_device_rename_db(struct udev_device *udev_device, const char *devpath_old)
 136 {
 137         char filename_old[UTIL_PATH_SIZE];
 138         char filename[UTIL_PATH_SIZE];
 139
 140         devpath_to_db_path(udev_device_get_udev(udev_device),
 141                            devpath_old,
 142                            filename_old, sizeof(filename_old));
 143         devpath_to_db_path(udev_device_get_udev(udev_device),
 144                            udev_device_get_devpath(udev_device),
 145                            filename, sizeof(filename));
 146         return rename(filename_old, filename);
 147 }