C script to monitor netlink events

1 files changed, 75 insertions, 0 deletions

diff --git a/scripts/netlink-monitor b/scripts/netlink-monitor
new file mode 100755
index 0000000..1f22922
--- /dev/null
+++ b/scripts/netlink-monitor
@@ -0,0 +1,75 @@
+#!/usr/bin/env C
+
+#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>
+
+int init_netlink_socket(int * netlink_socket)
+{
+    struct sockaddr_nl snl;
+    int ret;
+
+    memset(&snl, 0, sizeof(struct sockaddr_nl));
+    snl.nl_family = AF_NETLINK;
+    snl.nl_pid = getpid();
+    snl.nl_groups = 1;
+
+    *netlink_socket = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
+    if (*netlink_socket == -1) {
+        fprintf(stderr, "netlink socket: %s\n", strerror(errno));
+        return -1;
+    }
+
+    ret = bind(*netlink_socket, (struct sockaddr *) & snl,
+               sizeof(struct sockaddr_nl));
+    if (ret < 0) {
+        fprintf(stderr, "netlink bind failed: %s\n", strerror(errno));
+        close(*netlink_socket);
+        *netlink_socket = -1;
+        return -1;
+    }
+
+    return 0;
+}
+
+int main(void)
+{
+    int ret = -1;
+    int netlink_socket = -1;
+    int buflen = -1;
+    char netlink_buf[4096+1];
+
+    ret = init_netlink_socket(&netlink_socket);
+    if (ret) {
+        fprintf(stderr, "init_netlink_socket() has failed %s\n",
+                strerror(errno));
+        close(netlink_socket);
+        return -1;
+    }
+
+    while (1) {
+        buflen = recv(netlink_socket, netlink_buf, sizeof(netlink_buf)-1 , 0);
+        if (buflen <= 0) {
+            fprintf(stderr, "error receiving uevent message: %s\n",
+                    strerror(errno));
+        } else {
+            netlink_buf[buflen-1] = '\0';
+            printf("%s\n", netlink_buf);
+            fflush(stdout);
+        }
+    }
+
+    return 0;
+}