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 int udev_device_update_db(struct udev_device *udev_device)
  25 {
  26         struct udev *udev = udev_device_get_udev(udev_device);
  27         char filename[UTIL_PATH_SIZE];
  28         FILE *f;
  29         char target[232]; /* on 64bit, tmpfs inlines up to 239 bytes */
  30         size_t devlen = strlen(udev_get_dev_path(udev))+1;
  31         char *s;
  32         size_t l;
  33         struct udev_list_entry *list_entry;
  34         int ret;
  35
  36         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db/",
  37                       udev_device_get_subsystem(udev_device), ":", udev_device_get_sysname(udev_device), NULL);
  38         unlink(filename);
  39
  40         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device))
  41                 if (udev_list_entry_get_flag(list_entry))
  42                         goto file;
  43         if (udev_device_get_num_fake_partitions(udev_device) != 0)
  44                 goto file;
  45         if (udev_device_get_ignore_remove(udev_device))
  46                 goto file;
  47         if (udev_device_get_devlink_priority(udev_device) != 0)
  48                 goto file;
  49         if (udev_device_get_event_timeout(udev_device) >= 0)
  50                 goto file;
  51         if (udev_device_get_watch_handle(udev_device) >= 0)
  52                 goto file;
  53         if (udev_device_get_devnode(udev_device) == NULL)
  54                 goto out;
  55
  56         /*
  57          * if we have only the node and symlinks to store, try not to waste
  58          * tmpfs memory -- store values, if they fit, in a symlink target
  59          */
  60         s = target;
  61         l = util_strpcpy(&s, sizeof(target), &udev_device_get_devnode(udev_device)[devlen]);
  62         udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device)) {
  63                 l = util_strpcpyl(&s, l, " ", &udev_list_entry_get_name(list_entry)[devlen], NULL);
  64                 if (l == 0) {
  65                         info(udev, "size of links too large, create file\n");
  66                         goto file;
  67                 }
  68         }
  69         info(udev, "create db link (%s)\n", target);
  70         udev_selinux_setfscreatecon(udev, filename, S_IFLNK);
  71         util_create_path(udev, filename);
  72         ret = symlink(target, filename);
  73         udev_selinux_resetfscreatecon(udev);
  74         if (ret == 0)
  75                 goto out;
  76 file:
  77         util_create_path(udev, filename);
  78         f = fopen(filename, "w");
  79         if (f == NULL) {
  80                 err(udev, "unable to create db file '%s': %m\n", filename);
  81                 return -1;
  82                 }
  83         info(udev, "created db file for '%s' in '%s'\n", udev_device_get_devpath(udev_device), filename);
  84
  85         if (udev_device_get_devnode(udev_device) != NULL) {
  86                 fprintf(f, "N:%s\n", &udev_device_get_devnode(udev_device)[devlen]);
  87                 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device))
  88                         fprintf(f, "S:%s\n", &udev_list_entry_get_name(list_entry)[devlen]);
  89         }
  90         if (udev_device_get_devlink_priority(udev_device) != 0)
  91                 fprintf(f, "L:%i\n", udev_device_get_devlink_priority(udev_device));
  92         if (udev_device_get_event_timeout(udev_device) >= 0)
  93                 fprintf(f, "T:%i\n", udev_device_get_event_timeout(udev_device));
  94         if (udev_device_get_num_fake_partitions(udev_device) != 0)
  95                 fprintf(f, "A:%i\n", udev_device_get_num_fake_partitions(udev_device));
  96         if (udev_device_get_ignore_remove(udev_device))
  97                 fprintf(f, "R:%i\n", udev_device_get_ignore_remove(udev_device));
  98         if (udev_device_get_watch_handle(udev_device) >= 0)
  99                 fprintf(f, "W:%i\n", udev_device_get_watch_handle(udev_device));
 100         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
 101                 if (!udev_list_entry_get_flag(list_entry))
 102                         continue;
 103                 fprintf(f, "E:%s=%s\n",
 104                         udev_list_entry_get_name(list_entry),
 105                         udev_list_entry_get_value(list_entry));
 106         }
 107         fclose(f);
 108 out:
 109         return 0;
 110 }
 111
 112 int udev_device_delete_db(struct udev_device *udev_device)
 113 {
 114         struct udev *udev = udev_device_get_udev(udev_device);
 115         char filename[UTIL_PATH_SIZE];
 116
 117         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db/",
 118                       udev_device_get_subsystem(udev_device), ":", udev_device_get_sysname(udev_device), NULL);
 119         unlink(filename);
 120         return 0;
 121 }
 122
 123 int udev_device_rename_db(struct udev_device *udev_device)
 124 {
 125         struct udev *udev = udev_device_get_udev(udev_device);
 126         char filename_old[UTIL_PATH_SIZE];
 127         char filename[UTIL_PATH_SIZE];
 128
 129         util_strscpyl(filename_old, sizeof(filename_old), udev_get_dev_path(udev), "/.udev/db/",
 130                       udev_device_get_subsystem(udev_device), ":", udev_device_get_sysname_old(udev_device), NULL);
 131         util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db/",
 132                       udev_device_get_subsystem(udev_device), ":", udev_device_get_sysname(udev_device), NULL);
 133         return rename(filename_old, filename);
 134 }