examples: add genl-group-events

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

2 files changed, 68 insertions, 1 deletions

diff --git a/examples/genl/Makefile.am b/examples/genl/Makefile.am
index deaf18d..b4b7954 100644
--- a/examples/genl/Makefile.am
+++ b/examples/genl/Makefile.am
@@ -1,6 +1,10 @@
 include $(top_srcdir)/Make_global.am
 
-check_PROGRAMS = genl-family-get
+check_PROGRAMS = genl-family-get	\
+		 genl-group-events
 
 genl_family_get_SOURCES = genl-family-get.c
 genl_family_get_LDADD = ../../src/libmnl.la
+
+genl_group_events_SOURCES = genl-group-events.c
+genl_group_events_LDADD = ../../src/libmnl.la
diff --git a/examples/genl/genl-group-events.c b/examples/genl/genl-group-events.c
new file mode 100644
index 0000000..d5f0a18
--- /dev/null
+++ b/examples/genl/genl-group-events.c
@@ -0,0 +1,63 @@
+/* This example is placed in the public domain. */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+
+#include <libmnl/libmnl.h>
+#include <linux/genetlink.h>
+
+static int group;
+
+static int data_cb(const struct nlmsghdr *nlh, void *data)
+{
+	printf("received event type=%d from genetlink group %d\n",
+		nlh->nlmsg_type, group);
+	return MNL_CB_OK;
+}
+
+int main(int argc, char *argv[])
+{
+	struct mnl_socket *nl;
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	int ret;
+
+	if (argc != 2) {
+		printf("%s [group]\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+	group = atoi(argv[1]);
+
+	nl = mnl_socket_open(NETLINK_GENERIC);
+	if (nl == NULL) {
+		perror("mnl_socket_open");
+		exit(EXIT_FAILURE);
+	}
+
+	if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
+		perror("mnl_socket_bind");
+		exit(EXIT_FAILURE);
+	}
+
+	if (mnl_socket_setsockopt(nl, NETLINK_ADD_MEMBERSHIP, &group,
+				  sizeof(int)) < 0) {
+		perror("mnl_socket_setsockopt");
+		exit(EXIT_FAILURE);
+	}
+
+	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	while (ret > 0) {
+		ret = mnl_cb_run(buf, ret, 0, 0, data_cb, NULL);
+		if (ret <= 0)
+			break;
+		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	}
+	if (ret == -1) {
+		perror("error");
+		exit(EXIT_FAILURE);
+	}
+
+	mnl_socket_close(nl);
+
+	return 0;
+}