libudev/libudev-device-private.c

   1 /*
   2  * libudev - interface to udev device information
   3  *
   4  * Copyright (C) 2008-2010 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 <stdbool.h>
  17 #include <unistd.h>
  18 #include <fcntl.h>
  19 #include <string.h>
  20 #include <sys/stat.h>
  21
  22 #include "libudev.h"
  23 #include "libudev-private.h"
  24
  25 static void udev_device_tag(struct udev_device *dev, const char *tag, bool add)
  26 {
  27         const char *id;
  28         struct udev *udev = udev_device_get_udev(dev);
  29         char filename[UTIL_PATH_SIZE];
  30
  31         id = udev_device_get_id_filename(dev);
  32         if (id == NULL)
  33                 return;
  34         util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/tags/", tag, "/", id, NULL);
  35
  36         if (add) {
  37                 int fd;
  38
  39                 util_create_path(udev, filename);
  40                 fd = open(filename, O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
  41                 if (fd >= 0)
  42                         close(fd);
  43         } else {
  44                 unlink(filename);
  45         }
  46 }
  47
  48 int udev_device_tag_index(struct udev_device *dev, struct udev_device *dev_old, bool add)
  49 {
  50         struct udev_list_entry *list_entry;
  51         bool found;
  52
  53         if (add && dev_old != NULL) {
  54                 /* delete possible left-over tags */
  55                 udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(dev_old)) {
  56                         const char *tag_old = udev_list_entry_get_name(list_entry);
  57                         struct udev_list_entry *list_entry_current;
  58
  59                         found = false;
  60                         udev_list_entry_foreach(list_entry_current, udev_device_get_tags_list_entry(dev)) {
  61                                 const char *tag = udev_list_entry_get_name(list_entry_current);
  62
  63                                 if (strcmp(tag, tag_old) == 0) {
  64                                         found = true;
  65                                         break;
  66                                 }
  67                         }
  68                         if (!found)
  69                                 udev_device_tag(dev_old, tag_old, false);
  70                 }
  71         }
  72
  73         udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(dev))
  74                 udev_device_tag(dev, udev_list_entry_get_name(list_entry), add);
  75
  76         return 0;
  77 }
  78
  79 static bool device_has_info(struct udev_device *udev_device)
  80 {
  81         struct udev *udev = udev_device_get_udev(udev_device);
  82         struct udev_list_entry *list_entry;
  83
  84         if (udev_device_get_devlinks_list_entry(udev_device) != NULL)
  85                 return true;
  86         if (udev_device_get_devlink_priority(udev_device) != 0)
  87                 return true;
  88         udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device))
  89                 if (udev_list_entry_get_flags(list_entry))
  90                         return true;
  91         if (udev_device_get_tags_list_entry(udev_device) != NULL)
  92                 return true;
  93         if (udev_device_get_devnode(udev_device) != NULL && udev_device_get_knodename(udev_device) != NULL) {
  94                 size_t devlen = strlen(udev_get_dev_path(udev))+1;
  95
  96                 if (strcmp(&udev_device_get_devnode(udev_device)[devlen], udev_device_get_knodename(udev_device)) != 0)
  97                         return true;
  98         }
  99         if (udev_device_get_watch_handle(udev_device) >= 0)
 100                 return true;
 101         return false;
 102 }
 103
 104 int udev_device_update_db(struct udev_device *udev_device)
 105 {
 106         bool has_info;
 107         const char *id;
 108         struct udev *udev = udev_device_get_udev(udev_device);
 109         char filename[UTIL_PATH_SIZE];
 110         char filename_tmp[UTIL_PATH_SIZE];
 111         FILE *f;
 112
 113         id = udev_device_get_id_filename(udev_device);
 114         if (id == NULL)
 115                 return -1;
 116
 117         has_info = device_has_info(udev_device);
 118         util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data/", id, NULL);
 119
 120         /* do not store anything for otherwise empty devices */
 121         if (!has_info &&
 122             major(udev_device_get_devnum(udev_device)) == 0 &&
 123             udev_device_get_ifindex(udev_device) == 0) {
 124                 unlink(filename);
 125                 return 0;
 126         }
 127
 128         /* write a database file */
 129         util_strscpyl(filename_tmp, sizeof(filename_tmp), filename, ".tmp", NULL);
 130         util_create_path(udev, filename_tmp);
 131         f = fopen(filename_tmp, "we");
 132         if (f == NULL) {
 133                 err(udev, "unable to create temporary db file '%s': %m\n", filename_tmp);
 134                 return -1;
 135         }
 136
 137         if (has_info) {
 138                 size_t devlen = strlen(udev_get_dev_path(udev))+1;
 139                 struct udev_list_entry *list_entry;
 140
 141                 if (udev_device_get_devnode(udev_device) != NULL) {
 142                         fprintf(f, "N:%s\n", &udev_device_get_devnode(udev_device)[devlen]);
 143                         udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device))
 144                                 fprintf(f, "S:%s\n", &udev_list_entry_get_name(list_entry)[devlen]);
 145                 }
 146                 if (udev_device_get_devlink_priority(udev_device) != 0)
 147                         fprintf(f, "L:%i\n", udev_device_get_devlink_priority(udev_device));
 148                 if (udev_device_get_watch_handle(udev_device) >= 0)
 149                         fprintf(f, "W:%i\n", udev_device_get_watch_handle(udev_device));
 150                 if (udev_device_get_usec_initialized(udev_device) > 0)
 151                         fprintf(f, "I:%llu\n", udev_device_get_usec_initialized(udev_device));
 152                 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
 153                         if (!udev_list_entry_get_flags(list_entry))
 154                                 continue;
 155                         fprintf(f, "E:%s=%s\n",
 156                                 udev_list_entry_get_name(list_entry),
 157                                 udev_list_entry_get_value(list_entry));
 158                 }
 159                 udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
 160                         fprintf(f, "G:%s\n", udev_list_entry_get_name(list_entry));
 161         }
 162
 163         fclose(f);
 164         rename(filename_tmp, filename);
 165         info(udev, "created %s file '%s' for '%s'\n", has_info ? "db" : "empty",
 166              filename, udev_device_get_devpath(udev_device));
 167         return 0;
 168 }
 169
 170 int udev_device_delete_db(struct udev_device *udev_device)
 171 {
 172         const char *id;
 173         struct udev *udev = udev_device_get_udev(udev_device);
 174         char filename[UTIL_PATH_SIZE];
 175
 176         id = udev_device_get_id_filename(udev_device);
 177         if (id == NULL)
 178                 return -1;
 179         util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data/", id, NULL);
 180         unlink(filename);
 181         return 0;
 182 }