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[elogind.git] / src / udev / udevadm-monitor.c
1 /*
2  * Copyright (C) 2004-2010 Kay Sievers <kay@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 <unistd.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <stddef.h>
22 #include <string.h>
23 #include <fcntl.h>
24 #include <errno.h>
25 #include <signal.h>
26 #include <getopt.h>
27 #include <time.h>
28 #include <sys/time.h>
29 #include <sys/socket.h>
30 #include <sys/un.h>
31 #include <sys/epoll.h>
32 #include <linux/types.h>
33 #include <linux/netlink.h>
34
35 #include "udev.h"
36 #include "udev-util.h"
37
38 static bool udev_exit;
39
40 static void sig_handler(int signum) {
41         if (signum == SIGINT || signum == SIGTERM)
42                 udev_exit = true;
43 }
44
45 static void print_device(struct udev_device *device, const char *source, int prop) {
46         struct timespec ts;
47
48         clock_gettime(CLOCK_MONOTONIC, &ts);
49         printf("%-6s[%"PRI_TIME".%06ld] %-8s %s (%s)\n",
50                source,
51                ts.tv_sec, ts.tv_nsec/1000,
52                udev_device_get_action(device),
53                udev_device_get_devpath(device),
54                udev_device_get_subsystem(device));
55         if (prop) {
56                 struct udev_list_entry *list_entry;
57
58                 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(device))
59                         printf("%s=%s\n",
60                                udev_list_entry_get_name(list_entry),
61                                udev_list_entry_get_value(list_entry));
62                 printf("\n");
63         }
64 }
65
66 static void help(void) {
67         printf("Usage: udevadm monitor [--property] [--kernel] [--udev] [--help]\n"
68                "  -p,--property                            print the event properties\n"
69                "  -k,--kernel                              print kernel uevents\n"
70                "  -u,--udev                                print udev events\n"
71                "  -s,--subsystem-match=SUBSYSTEM[/DEVTYPE] filter events by subsystem\n"
72                "  -t,--tag-match=TAG                       filter events by tag\n"
73                "  -h,--help\n\n");
74 }
75
76 static int adm_monitor(struct udev *udev, int argc, char *argv[]) {
77         struct sigaction act = {};
78         sigset_t mask;
79         bool prop = false;
80         bool print_kernel = false;
81         bool print_udev = false;
82         _cleanup_udev_list_cleanup_ struct udev_list subsystem_match_list;
83         _cleanup_udev_list_cleanup_ struct udev_list tag_match_list;
84         _cleanup_udev_monitor_unref_ struct udev_monitor *udev_monitor = NULL;
85         _cleanup_udev_monitor_unref_ struct udev_monitor *kernel_monitor = NULL;
86         _cleanup_close_ int fd_ep = -1;
87         int fd_kernel = -1, fd_udev = -1;
88         struct epoll_event ep_kernel, ep_udev;
89         int c;
90
91         static const struct option options[] = {
92                 { "property",        no_argument,       NULL, 'p' },
93                 { "environment",     no_argument,       NULL, 'e' }, /* alias for -p */
94                 { "kernel",          no_argument,       NULL, 'k' },
95                 { "udev",            no_argument,       NULL, 'u' },
96                 { "subsystem-match", required_argument, NULL, 's' },
97                 { "tag-match",       required_argument, NULL, 't' },
98                 { "help",            no_argument,       NULL, 'h' },
99                 {}
100         };
101
102         udev_list_init(udev, &subsystem_match_list, true);
103         udev_list_init(udev, &tag_match_list, true);
104
105         while((c = getopt_long(argc, argv, "pekus:t:h", options, NULL)) >= 0)
106                 switch (c) {
107                 case 'p':
108                 case 'e':
109                         prop = true;
110                         break;
111                 case 'k':
112                         print_kernel = true;
113                         break;
114                 case 'u':
115                         print_udev = true;
116                         break;
117                 case 's':
118                         {
119                                 char subsys[UTIL_NAME_SIZE];
120                                 char *devtype;
121
122                                 strscpy(subsys, sizeof(subsys), optarg);
123                                 devtype = strchr(subsys, '/');
124                                 if (devtype != NULL) {
125                                         devtype[0] = '\0';
126                                         devtype++;
127                                 }
128                                 udev_list_entry_add(&subsystem_match_list, subsys, devtype);
129                                 break;
130                         }
131                 case 't':
132                         udev_list_entry_add(&tag_match_list, optarg, NULL);
133                         break;
134                 case 'h':
135                         help();
136                         return 0;
137                 default:
138                         return 1;
139                 }
140
141         if (!print_kernel && !print_udev) {
142                 print_kernel = true;
143                 print_udev = true;
144         }
145
146         /* set signal handlers */
147         act.sa_handler = sig_handler;
148         act.sa_flags = SA_RESTART;
149         sigaction(SIGINT, &act, NULL);
150         sigaction(SIGTERM, &act, NULL);
151         sigemptyset(&mask);
152         sigaddset(&mask, SIGINT);
153         sigaddset(&mask, SIGTERM);
154         sigprocmask(SIG_UNBLOCK, &mask, NULL);
155
156         fd_ep = epoll_create1(EPOLL_CLOEXEC);
157         if (fd_ep < 0) {
158                 log_error("error creating epoll fd: %m");
159                 return 1;
160         }
161
162         printf("monitor will print the received events for:\n");
163         if (print_udev) {
164                 struct udev_list_entry *entry;
165
166                 udev_monitor = udev_monitor_new_from_netlink(udev, "udev");
167                 if (udev_monitor == NULL) {
168                         fprintf(stderr, "error: unable to create netlink socket\n");
169                         return 1;
170                 }
171                 udev_monitor_set_receive_buffer_size(udev_monitor, 128*1024*1024);
172                 fd_udev = udev_monitor_get_fd(udev_monitor);
173
174                 udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) {
175                         const char *subsys = udev_list_entry_get_name(entry);
176                         const char *devtype = udev_list_entry_get_value(entry);
177
178                         if (udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, subsys, devtype) < 0)
179                                 fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys);
180                 }
181
182                 udev_list_entry_foreach(entry, udev_list_get_entry(&tag_match_list)) {
183                         const char *tag = udev_list_entry_get_name(entry);
184
185                         if (udev_monitor_filter_add_match_tag(udev_monitor, tag) < 0)
186                                 fprintf(stderr, "error: unable to apply tag filter '%s'\n", tag);
187                 }
188
189                 if (udev_monitor_enable_receiving(udev_monitor) < 0) {
190                         fprintf(stderr, "error: unable to subscribe to udev events\n");
191                         return 2;
192                 }
193
194                 memzero(&ep_udev, sizeof(struct epoll_event));
195                 ep_udev.events = EPOLLIN;
196                 ep_udev.data.fd = fd_udev;
197                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_udev, &ep_udev) < 0) {
198                         log_error("fail to add fd to epoll: %m");
199                         return 2;
200                 }
201
202                 printf("UDEV - the event which udev sends out after rule processing\n");
203         }
204
205         if (print_kernel) {
206                 struct udev_list_entry *entry;
207
208                 kernel_monitor = udev_monitor_new_from_netlink(udev, "kernel");
209                 if (kernel_monitor == NULL) {
210                         fprintf(stderr, "error: unable to create netlink socket\n");
211                         return 3;
212                 }
213                 udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
214                 fd_kernel = udev_monitor_get_fd(kernel_monitor);
215
216                 udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) {
217                         const char *subsys = udev_list_entry_get_name(entry);
218
219                         if (udev_monitor_filter_add_match_subsystem_devtype(kernel_monitor, subsys, NULL) < 0)
220                                 fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys);
221                 }
222
223                 if (udev_monitor_enable_receiving(kernel_monitor) < 0) {
224                         fprintf(stderr, "error: unable to subscribe to kernel events\n");
225                         return 4;
226                 }
227
228                 memzero(&ep_kernel, sizeof(struct epoll_event));
229                 ep_kernel.events = EPOLLIN;
230                 ep_kernel.data.fd = fd_kernel;
231                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_kernel, &ep_kernel) < 0) {
232                         log_error("fail to add fd to epoll: %m");
233                         return 5;
234                 }
235
236                 printf("KERNEL - the kernel uevent\n");
237         }
238         printf("\n");
239
240         while (!udev_exit) {
241                 int fdcount;
242                 struct epoll_event ev[4];
243                 int i;
244
245                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
246                 if (fdcount < 0) {
247                         if (errno != EINTR)
248                                 fprintf(stderr, "error receiving uevent message: %m\n");
249                         continue;
250                 }
251
252                 for (i = 0; i < fdcount; i++) {
253                         if (ev[i].data.fd == fd_kernel && ev[i].events & EPOLLIN) {
254                                 struct udev_device *device;
255
256                                 device = udev_monitor_receive_device(kernel_monitor);
257                                 if (device == NULL)
258                                         continue;
259                                 print_device(device, "KERNEL", prop);
260                                 udev_device_unref(device);
261                         } else if (ev[i].data.fd == fd_udev && ev[i].events & EPOLLIN) {
262                                 struct udev_device *device;
263
264                                 device = udev_monitor_receive_device(udev_monitor);
265                                 if (device == NULL)
266                                         continue;
267                                 print_device(device, "UDEV", prop);
268                                 udev_device_unref(device);
269                         }
270                 }
271         }
272
273         return 0;
274 }
275
276 const struct udevadm_cmd udevadm_monitor = {
277         .name = "monitor",
278         .cmd = adm_monitor,
279         .help = "listen to kernel and udev events",
280 };