initial libmnl import

1 files changed, 192 insertions, 0 deletions

diff --git a/examples/rtnl-route-dump.c b/examples/rtnl-route-dump.c
new file mode 100644
index 0000000..e8f3a0c
--- /dev/null
+++ b/examples/rtnl-route-dump.c
@@ -0,0 +1,192 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <libmnl/libmnl.h>
+#include <linux/if.h>
+#include <linux/if_link.h>
+#include <linux/rtnetlink.h>
+
+static void attributes_show_ipv4(struct nlattr *tb[])
+{
+	if (tb[RTA_TABLE]) {
+		printf("table=%u ", mnl_attr_get_u32(tb[RTA_TABLE]));
+	}
+	if (tb[RTA_DST]) {
+		printf("dst=%s ", inet_ntoa(mnl_attr_get_u32(tb[RTA_DST])));
+	}
+	if (tb[RTA_SRC]) {
+		printf("src=%s ", inet_ntoa(mnl_attr_get_u32(tb[RTA_SRC])));
+	}
+	if (tb[RTA_OIF]) {
+		printf("oif=%u ", mnl_attr_get_u32(tb[RTA_OIF]));
+	}
+	if (tb[RTA_FLOW]) {
+		printf("flow=%u ", mnl_attr_get_u32(tb[RTA_FLOW]));
+	}
+	if (tb[RTA_PREFSRC]) {
+		printf("prefsrc=%s ",
+			inet_ntoa(mnl_attr_get_u32(tb[RTA_PREFSRC])));
+	}
+	if (tb[RTA_GATEWAY]) {
+		printf("gw=%s ", inet_ntoa(mnl_attr_get_u32(tb[RTA_GATEWAY])));
+	}
+	if (tb[RTA_METRICS]) {
+		int i;
+		struct nlattr *tbx[RTAX_MAX+1] = {};
+
+		mnl_attr_parse_nested(tb[RTA_METRICS], tbx, RTAX_MAX);
+
+		for (i=0; i<RTAX_MAX; i++) {
+			if (tbx[i]) {
+				printf("metrics[%d]=%u ",
+					mnl_attr_get_u32(tbx[i]));
+			}
+		}
+	}
+	printf("\n");
+}
+
+static int data_cb(const struct nlmsghdr *nlh, void *data)
+{
+	/* parse() ya está inicializando este array, qué hacer ? */
+	struct nlattr *tb[RTA_MAX+1] = {};
+	struct rtmsg *rm = mnl_nlmsg_get_data(nlh);
+	int len = mnl_nlmsg_get_len(nlh);
+	struct nlattr *attr;
+
+	/* protocol family = AF_INET | AF_INET6 */
+	printf("family=%u ", rm->rtm_family);
+
+	/* destination CIDR, eg. 24 or 32 for IPv4 */
+	printf("dst_len=%u ", rm->rtm_dst_len);
+
+	/* source CIDR */
+	printf("src_len=%u ", rm->rtm_src_len);
+
+	/* type of service (TOS), eg. 0 */
+	printf("tos=%u ", rm->rtm_tos);
+
+	/* table id:
+	 *	RT_TABLE_UNSPEC		= 0
+	 *
+	 * 	... user defined values ...
+	 *
+	 *	RT_TABLE_COMPAT		= 252
+	 *	RT_TABLE_DEFAULT	= 253
+	 *	RT_TABLE_MAIN		= 254
+	 *	RT_TABLE_LOCAL		= 255
+	 *	RT_TABLE_MAX		= 0xFFFFFFFF
+	 *
+	 * Synonimous attribute: RTA_TABLE.
+	 */
+	printf("table=%u ", rm->rtm_table);
+
+	/* type:
+	 * 	RTN_UNSPEC	= 0
+	 * 	RTN_UNICAST	= 1
+	 * 	RTN_LOCAL	= 2
+	 * 	RTN_BROADCAST	= 3
+	 *	RTN_ANYCAST	= 4
+	 *	RTN_MULTICAST	= 5
+	 *	RTN_BLACKHOLE	= 6
+	 *	RTN_UNREACHABLE	= 7
+	 *	RTN_PROHIBIT	= 8
+	 *	RTN_THROW	= 9
+	 *	RTN_NAT		= 10
+	 *	RTN_XRESOLVE	= 11
+	 *	__RTN_MAX	= 12
+	 */
+	printf("type=%u ", rm->rtm_type);
+
+	/* scope:
+	 * 	RT_SCOPE_UNIVERSE	= 0   : everywhere in the universe
+	 *
+	 *      ... user defined values ...
+	 *
+	 * 	RT_SCOPE_SITE		= 200
+	 * 	RT_SCOPE_LINK		= 253 : destination attached to link
+	 * 	RT_SCOPE_HOST		= 254 : local address
+	 * 	RT_SCOPE_NOWHERE	= 255 : not existing destination
+	 */
+	printf("scope=%u ", rm->rtm_scope);
+
+	/* protocol:
+	 * 	RTPROT_UNSPEC	= 0
+	 * 	RTPROT_REDIRECT = 1
+	 * 	RTPROT_KERNEL	= 2 : route installed by kernel
+	 * 	RTPROT_BOOT	= 3 : route installed during boot
+	 * 	RTPROT_STATIC	= 4 : route installed by administrator
+	 *
+	 * Values >= RTPROT_STATIC are not interpreted by kernel, they are
+	 * just user-defined.
+	 */
+	printf("proto=%u ", rm->rtm_protocol);
+
+	/* flags:
+	 * 	RTM_F_NOTIFY	= 0x100: notify user of route change
+	 * 	RTM_F_CLONED	= 0x200: this route is cloned
+	 * 	RTM_F_EQUALIZE	= 0x400: Multipath equalizer: NI
+	 * 	RTM_F_PREFIX	= 0x800: Prefix addresses
+	 */
+	printf("flags=%x\n", rm->rtm_flags);
+
+	mnl_attr_parse_at_offset(nlh, sizeof(*rm), tb, RTA_MAX);
+
+	switch(rm->rtm_family) {
+	case AF_INET:
+		attributes_show_ipv4(tb);
+		break;
+	}
+
+	return MNL_CB_OK;
+}
+
+int main()
+{
+	struct mnl_socket *nl;
+	char buf[getpagesize()];
+	struct nlmsghdr *nlh;
+	struct rtmsg *rtm;
+	int ret;
+	unsigned int seq;
+
+	nlh = mnl_nlmsg_put_header(buf);
+	nlh->nlmsg_type = RTM_GETROUTE;
+	nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
+	nlh->nlmsg_seq = seq = time(NULL);
+	rtm = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtmsg));
+	rtm->rtm_family = AF_INET;
+
+	nl = mnl_socket_open(NETLINK_ROUTE);
+	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_sendto(nl, nlh, mnl_nlmsg_get_len(nlh)) < 0) {
+		perror("mnl_socket_send");
+		exit(EXIT_FAILURE);
+	}
+
+	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	while (ret > 0) {
+		ret = mnl_cb_run(buf, ret, 0, data_cb, NULL);
+		if (ret <= MNL_CB_STOP)
+			break;
+		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	}
+	if (ret == -1) {
+		perror("error");
+		exit(EXIT_FAILURE);
+	}
+
+	mnl_socket_close(nl);
+
+	return 0;
+}