1 /***
2 This file is part of systemd.
3
4 Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
5
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
10
11 systemd 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 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
18 ***/
19
20 #include <stdlib.h>
21 #include <stdio.h>
22 #include <string.h>
23 #include <stddef.h>
24 #include <stdbool.h>
25 #include <unistd.h>
26 #include <fcntl.h>
27 #include <sys/stat.h>
28 #include <sys/sysmacros.h>
29
30 #include "libudev.h"
31 #include "libudev-private.h"
32
udev_device_tag(struct udev_device * dev,const char * tag,bool add)33 static void udev_device_tag(struct udev_device *dev, const char *tag, bool add)
34 {
35 const char *id;
36 char filename[UTIL_PATH_SIZE];
37
38 id = udev_device_get_id_filename(dev);
39 if (id == NULL)
40 return;
41 strscpyl(filename, sizeof(filename), UDEV_ROOT_RUN "/udev/tags/", tag, "/", id, NULL);
42
43 if (add) {
44 int fd;
45
46 mkdir_parents(filename, 0755);
47 fd = open(filename, O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444);
48 if (fd >= 0)
49 close(fd);
50 } else {
51 unlink(filename);
52 }
53 }
54
udev_device_tag_index(struct udev_device * dev,struct udev_device * dev_old,bool add)55 int udev_device_tag_index(struct udev_device *dev, struct udev_device *dev_old, bool add)
56 {
57 struct udev_list_entry *list_entry;
58 bool found;
59
60 if (add && dev_old != NULL) {
61 /* delete possible left-over tags */
62 udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(dev_old)) {
63 const char *tag_old = udev_list_entry_get_name(list_entry);
64 struct udev_list_entry *list_entry_current;
65
66 found = false;
67 udev_list_entry_foreach(list_entry_current, udev_device_get_tags_list_entry(dev)) {
68 const char *tag = udev_list_entry_get_name(list_entry_current);
69
70 if (streq(tag, tag_old)) {
71 found = true;
72 break;
73 }
74 }
75 if (!found)
76 udev_device_tag(dev_old, tag_old, false);
77 }
78 }
79
80 udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(dev))
81 udev_device_tag(dev, udev_list_entry_get_name(list_entry), add);
82
83 return 0;
84 }
85
device_has_info(struct udev_device * udev_device)86 static bool device_has_info(struct udev_device *udev_device)
87 {
88 struct udev_list_entry *list_entry;
89
90 if (udev_device_get_devlinks_list_entry(udev_device) != NULL)
91 return true;
92 if (udev_device_get_devlink_priority(udev_device) != 0)
93 return true;
94 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device))
95 if (udev_list_entry_get_num(list_entry))
96 return true;
97 if (udev_device_get_tags_list_entry(udev_device) != NULL)
98 return true;
99 if (udev_device_get_watch_handle(udev_device) >= 0)
100 return true;
101 return false;
102 }
103
udev_device_update_db(struct udev_device * udev_device)104 int udev_device_update_db(struct udev_device *udev_device)
105 {
106 bool has_info;
107 const char *id;
108 char filename[UTIL_PATH_SIZE];
109 char filename_tmp[UTIL_PATH_SIZE];
110 FILE *f;
111 int r;
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 strscpyl(filename, sizeof(filename), UDEV_ROOT_RUN "/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 strscpyl(filename_tmp, sizeof(filename_tmp), filename, ".tmp", NULL);
130 mkdir_parents(filename_tmp, 0755);
131 f = fopen(filename_tmp, "we");
132 if (f == NULL)
133 return log_debug_errno(errno, "unable to create temporary db file '%s': %m", filename_tmp);
134
135 /*
136 * set 'sticky' bit to indicate that we should not clean the
137 * database when we transition from initramfs to the real root
138 */
139 if (udev_device_get_db_persist(udev_device))
140 fchmod(fileno(f), 01644);
141
142 if (has_info) {
143 struct udev_list_entry *list_entry;
144
145 if (major(udev_device_get_devnum(udev_device)) > 0) {
146 udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(udev_device))
147 fprintf(f, "S:%s\n", udev_list_entry_get_name(list_entry) + strlen("/dev/"));
148 if (udev_device_get_devlink_priority(udev_device) != 0)
149 fprintf(f, "L:%i\n", udev_device_get_devlink_priority(udev_device));
150 if (udev_device_get_watch_handle(udev_device) >= 0)
151 fprintf(f, "W:%i\n", udev_device_get_watch_handle(udev_device));
152 }
153
154 if (udev_device_get_usec_initialized(udev_device) > 0)
155 fprintf(f, "I:"USEC_FMT"\n", udev_device_get_usec_initialized(udev_device));
156
157 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(udev_device)) {
158 if (!udev_list_entry_get_num(list_entry))
159 continue;
160 fprintf(f, "E:%s=%s\n",
161 udev_list_entry_get_name(list_entry),
162 udev_list_entry_get_value(list_entry));
163 }
164
165 udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
166 fprintf(f, "G:%s\n", udev_list_entry_get_name(list_entry));
167 }
168
169 fclose(f);
170 r = rename(filename_tmp, filename);
171 if (r < 0)
172 return -1;
173 log_debug("created %s file '%s' for '%s'", has_info ? "db" : "empty",
174 filename, udev_device_get_devpath(udev_device));
175 return 0;
176 }
177
udev_device_delete_db(struct udev_device * udev_device)178 int udev_device_delete_db(struct udev_device *udev_device)
179 {
180 const char *id;
181 char filename[UTIL_PATH_SIZE];
182
183 id = udev_device_get_id_filename(udev_device);
184 if (id == NULL)
185 return -1;
186 strscpyl(filename, sizeof(filename), UDEV_ROOT_RUN "/udev/data/", id, NULL);
187
188 unlink(filename);
189 return 0;
190 }
191