libudev/libudev-device-private.c

   1 /*
   2  * libudev - interface to udev device information
   3  *
   4  * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <stdlib.h>
  13 #include <stdio.h>
  14 #include <string.h>
  15 #include <stddef.h>
  16 #include <unistd.h>
  17 #include <fcntl.h>
  18 #include <string.h>
  19 #include <sys/stat.h>
  20
  21 #include "libudev.h"
  22 #include "libudev-private.h"
  23
  24 static size_t devpath_to_db_path(struct udev *udev, const char *devpath, char *filename, size_t len)
  25 {
  26         char *s;
  27         size_t l;
  28
  29         s = filename;
  30         l = util_strpcpyl(&s, len, udev_get_dev_path(udev), "/.udev/db/", NULL);
  31         return util_path_encode(devpath, s, l);
  32 }
  33
  34 int udev_device_update_db(struct udev_device *udev_device)
  35 {
  36         struct udev *udev = udev_device_get_udev(udev_device);
  37         char filename[UTIL_PATH_SIZE];
  38         FILE *f;
  39         char target[232]; /* on 64bit, tmpfs inlines up to 239 bytes */
  40         size_t devlen = strlen(udev_get_dev_path(udev))+1;
  41         char *s;
  42         size_t l;
  43         struct udev_list_entry *list_entry;
  44         int ret;
  45
  46         devpath_to_db_path(udev, udev_device_get_devpath(udev_device), filename, sizeof(filename));
  47         util_create_path(udev, filename);
  48         unlink(filename);
  49
  50         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device))
  51                 if (udev_list_entry_get_flag(list_entry))
  52                         goto file;
  53         if (udev_device_get_num_fake_partitions(udev_device) != 0)
  54                 goto file;
  55         if (udev_device_get_ignore_remove(udev_device))
  56                 goto file;
  57         if (udev_device_get_devlink_priority(udev_device) != 0)
  58                 goto file;
  59         if (udev_device_get_event_timeout(udev_device) >= 0)
  60                 goto file;
  61         if (udev_device_get_watch_handle(udev_device) >= 0)
  62                 goto file;
  63         if (udev_device_get_devnode(udev_device) == NULL)
  64                 goto out;
  65
  66         /*
  67          * if we have only the node and symlinks to store, try not to waste
  68          * tmpfs memory -- store values, if they fit, in a symlink target
  69          */
  70         s = target;
  71         l = util_strpcpy(&s, sizeof(target), &udev_device_get_devnode(udev_device)[devlen]);
  72         udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device)) {
  73                 l = util_strpcpyl(&s, l, " ", &udev_list_entry_get_name(list_entry)[devlen], NULL);
  74                 if (l == 0) {
  75                         info(udev, "size of links too large, create file\n");
  76                         goto file;
  77                 }
  78         }
  79         info(udev, "create db link (%s)\n", target);
  80         udev_selinux_setfscreatecon(udev, filename, S_IFLNK);
  81         ret = symlink(target, filename);
  82         udev_selinux_resetfscreatecon(udev);
  83         if (ret == 0)
  84                 goto out;
  85 file:
  86         f = fopen(filename, "w");
  87         if (f == NULL) {
  88                 err(udev, "unable to create db file '%s': %m\n", filename);
  89                 return -1;
  90                 }
  91         info(udev, "created db file for '%s' in '%s'\n", udev_device_get_devpath(udev_device), filename);
  92
  93         if (udev_device_get_devnode(udev_device) != NULL) {
  94                 fprintf(f, "N:%s\n", &udev_device_get_devnode(udev_device)[devlen]);
  95                 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device))
  96                         fprintf(f, "S:%s\n", &udev_list_entry_get_name(list_entry)[devlen]);
  97         }
  98         if (udev_device_get_devlink_priority(udev_device) != 0)
  99                 fprintf(f, "L:%u\n", udev_device_get_devlink_priority(udev_device));
 100         if (udev_device_get_event_timeout(udev_device) >= 0)
 101                 fprintf(f, "T:%u\n", udev_device_get_event_timeout(udev_device));
 102         if (udev_device_get_num_fake_partitions(udev_device) != 0)
 103                 fprintf(f, "A:%u\n", udev_device_get_num_fake_partitions(udev_device));
 104         if (udev_device_get_ignore_remove(udev_device))
 105                 fprintf(f, "R:%u\n", udev_device_get_ignore_remove(udev_device));
 106         if (udev_device_get_watch_handle(udev_device) >= 0)
 107                 fprintf(f, "W:%u\n", udev_device_get_watch_handle(udev_device));
 108         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
 109                 if (!udev_list_entry_get_flag(list_entry))
 110                         continue;
 111                 fprintf(f, "E:%s=%s\n",
 112                         udev_list_entry_get_name(list_entry),
 113                         udev_list_entry_get_value(list_entry));
 114         }
 115         fclose(f);
 116 out:
 117         return 0;
 118 }
 119
 120 int udev_device_delete_db(struct udev_device *udev_device)
 121 {
 122         struct udev *udev = udev_device_get_udev(udev_device);
 123         char filename[UTIL_PATH_SIZE];
 124
 125         devpath_to_db_path(udev, udev_device_get_devpath(udev_device), filename, sizeof(filename));
 126         unlink(filename);
 127         return 0;
 128 }
 129
 130 int udev_device_rename_db(struct udev_device *udev_device, const char *devpath_old)
 131 {
 132         struct udev *udev = udev_device_get_udev(udev_device);
 133         char filename_old[UTIL_PATH_SIZE];
 134         char filename[UTIL_PATH_SIZE];
 135
 136         devpath_to_db_path(udev, devpath_old, filename_old, sizeof(filename_old));
 137         devpath_to_db_path(udev, udev_device_get_devpath(udev_device), filename, sizeof(filename));
 138         return rename(filename_old, filename);
 139 }