udevmonitor.c revision 225cb03bd851adc6d269b13bdf2b1bfded2b96b9
/*
* Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <signal.h>
#include <getopt.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/select.h>
#include <linux/types.h>
#include <linux/netlink.h>
#include "udev.h"
#include "udevd.h"
static int uevent_netlink_sock = -1;
static int udev_monitor_sock = -1;
static volatile int udev_exit;
static int init_udev_monitor_socket(void)
{
struct sockaddr_un saddr;
socklen_t addrlen;
int retval;
memset(&saddr, 0x00, sizeof(saddr));
saddr.sun_family = AF_LOCAL;
/* use abstract namespace for socket path */
strcpy(&saddr.sun_path[1], "/org/kernel/udev/monitor");
addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
udev_monitor_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
if (udev_monitor_sock == -1) {
fprintf(stderr, "error getting socket: %s\n", strerror(errno));
return -1;
}
/* the bind takes care of ensuring only one copy running */
retval = bind(udev_monitor_sock, (struct sockaddr *) &saddr, addrlen);
if (retval < 0) {
fprintf(stderr, "bind failed: %s\n", strerror(errno));
close(udev_monitor_sock);
udev_monitor_sock = -1;
return -1;
}
return 0;
}
static int init_uevent_netlink_sock(void)
{
struct sockaddr_nl snl;
int retval;
memset(&snl, 0x00, sizeof(struct sockaddr_nl));
snl.nl_family = AF_NETLINK;
snl.nl_pid = getpid();
snl.nl_groups = 1;
uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
if (uevent_netlink_sock == -1) {
fprintf(stderr, "error getting socket: %s\n", strerror(errno));
return -1;
}
retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl,
sizeof(struct sockaddr_nl));
if (retval < 0) {
fprintf(stderr, "bind failed: %s\n", strerror(errno));
close(uevent_netlink_sock);
uevent_netlink_sock = -1;
return -1;
}
return 0;
}
static void asmlinkage sig_handler(int signum)
{
if (signum == SIGINT || signum == SIGTERM)
udev_exit = 1;
}
static const char *search_key(const char *searchkey, const char *buf, size_t buflen)
{
size_t bufpos = 0;
size_t searchkeylen = strlen(searchkey);
while (bufpos < buflen) {
const char *key;
int keylen;
key = &buf[bufpos];
keylen = strlen(key);
if (keylen == 0)
break;
if ((strncmp(searchkey, key, searchkeylen) == 0) && key[searchkeylen] == '=')
return &key[searchkeylen + 1];
bufpos += keylen + 1;
}
return NULL;
}
int udevmonitor(int argc, char *argv[], char *envp[])
{
struct sigaction act;
int option;
int env = 0;
int kernel = 0;
int udev = 0;
fd_set readfds;
int retval = 0;
static const struct option options[] = {
{ "environment", 0, NULL, 'e' },
{ "kernel", 0, NULL, 'k' },
{ "udev", 0, NULL, 'u' },
{ "help", 0, NULL, 'h' },
{}
};
while (1) {
option = getopt_long(argc, argv, "ekuh", options, NULL);
if (option == -1)
break;
switch (option) {
case 'e':
env = 1;
break;
case 'k':
kernel = 1;
break;
case 'u':
udev = 1;
break;
case 'h':
printf("Usage: udevadm monitor [--environment] [--kernel] [--udev] [--help]\n"
" --env print the whole event environment\n"
" --kernel print kernel uevents\n"
" --udev print udev events\n"
" --help print this help text\n\n");
default:
goto out;
}
}
if (!kernel && !udev) {
kernel = 1;
udev =1;
}
if (getuid() != 0 && kernel) {
fprintf(stderr, "root privileges needed to subscribe to kernel events\n");
goto out;
}
/* set signal handlers */
memset(&act, 0x00, sizeof(struct sigaction));
act.sa_handler = (void (*)(int)) sig_handler;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_RESTART;
sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL);
printf("udevmonitor will print the received events for:\n");
if (udev) {
retval = init_udev_monitor_socket();
if (retval)
goto out;
printf("UDEV the event which udev sends out after rule processing\n");
}
if (kernel) {
retval = init_uevent_netlink_sock();
if (retval)
goto out;
printf("UEVENT the kernel uevent\n");
}
printf("\n");
while (!udev_exit) {
char buf[UEVENT_BUFFER_SIZE*2];
ssize_t buflen;
ssize_t bufpos;
ssize_t keys;
int fdcount;
struct timeval tv;
struct timezone tz;
char timestr[64];
const char *source = NULL;
const char *devpath, *action, *subsys;
buflen = 0;
FD_ZERO(&readfds);
if (uevent_netlink_sock >= 0)
FD_SET(uevent_netlink_sock, &readfds);
if (udev_monitor_sock >= 0)
FD_SET(udev_monitor_sock, &readfds);
fdcount = select(UDEV_MAX(uevent_netlink_sock, udev_monitor_sock)+1, &readfds, NULL, NULL, NULL);
if (fdcount < 0) {
if (errno != EINTR)
fprintf(stderr, "error receiving uevent message: %s\n", strerror(errno));
continue;
}
if (gettimeofday(&tv, &tz) == 0) {
snprintf(timestr, sizeof(timestr), "%llu.%06u",
(unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec);
} else
timestr[0] = '\0';
if ((uevent_netlink_sock >= 0) && FD_ISSET(uevent_netlink_sock, &readfds)) {
buflen = recv(uevent_netlink_sock, &buf, sizeof(buf), 0);
if (buflen <= 0) {
fprintf(stderr, "error receiving uevent message: %s\n", strerror(errno));
continue;
}
source = "UEVENT";
}
if ((udev_monitor_sock >= 0) && FD_ISSET(udev_monitor_sock, &readfds)) {
buflen = recv(udev_monitor_sock, &buf, sizeof(buf), 0);
if (buflen <= 0) {
fprintf(stderr, "error receiving udev message: %s\n", strerror(errno));
continue;
}
source = "UDEV ";
}
if (buflen == 0)
continue;
keys = strlen(buf) + 1; /* start of payload */
devpath = search_key("DEVPATH", &buf[keys], buflen);
action = search_key("ACTION", &buf[keys], buflen);
subsys = search_key("SUBSYSTEM", &buf[keys], buflen);
printf("%s[%s] %-8s %s (%s)\n", source, timestr, action, devpath, subsys);
/* print environment */
bufpos = keys;
if (env) {
while (bufpos < buflen) {
int keylen;
char *key;
key = &buf[bufpos];
keylen = strlen(key);
if (keylen == 0)
break;
printf("%s\n", key);
bufpos += keylen + 1;
}
printf("\n");
}
}
out:
if (uevent_netlink_sock >= 0)
close(uevent_netlink_sock);
if (udev_monitor_sock >= 0)
close(udev_monitor_sock);
if (retval)
return 1;
return 0;
}