PF_NETLINK Kernel user interface device man 7 netlink
example code
hotplug.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/un.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <linux/types.h>
#include <linux/netlink.h>
#include <errno.h>
static int init_hotplug_sock(void)
{
struct sockaddr_nl snl;
const int buffersize = 16 1024 1024;
int retval;
memset(&snl, 0x00, sizeof(struct sockaddr_nl));
snl.nl_family = AF_NETLINK;
snl.nl_pid = getpid();
snl.nl_groups = 1;
int hotplug_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
if (hotplug_sock == -1) {
printf("error getting socket: %s", strerror(errno));
return -1;
}
/ set receive buffersize /
setsockopt(hotplug_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
retval = bind(hotplug_sock, (struct sockaddr ) &snl, sizeof(struct sockaddr_nl));
if (retval < 0) {
printf("bind failed: %s", strerror(errno));
close(hotplug_sock);
hotplug_sock = -1;
return -1;
}
return hotplug_sock;
}
#define UEVENT_BUFFER_SIZE 2048
int main(int argc, char argv[])
{
int hotplug_sock = init_hotplug_sock();
while(1)
{
char buf[UEVENT_BUFFER_SIZE*2] = {0};
recv(hotplug_sock, &buf, sizeof(buf), 0);
printf("%sn", buf);
}
return 0;
}
编译运行
jfo@jfo-laptop:~/test$ gcc -o hotplug hotplug.c
jfo@jfo-laptop:~/test$ sudo ./hotplug # 试着将sd卡或U盘拔下、插上
remove@/block/mmcblk0
remove@/devices/pci0000:00/0000:00:1e.0/0000:02:06.2/tifm_sd0:1/mmc_host/mmc1/mmc1:b368
remove@/devices/pci0000:00/0000:00:1e.0/0000:02:06.2/tifm_sd0:1/mmc_host/mmc1
remove@/devices/pci0000:00/0000:00:1e.0/0000:02:06.2/tifm_sd0:1
add@/devices/pci0000:00/0000:00:1e.0/0000:02:06.2/tifm_sd0:1
add@/devices/pci0000:00/0000:00:1e.0/0000:02:06.2/tifm_sd0:1/mmc_host/mmc1
add@/block/mmcblk0
add@/devices/pci0000:00/0000:00:1e.0/0000:02:06.2/tifm_sd0:1/mmc_host/mmc1/mmc1:b368
add@/kernel/uids/65534
remove@/kernel/uids/65534end