Commit 587323cf authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Daniel Borkmann
Browse files

samples, bpf: Move routes monitor in xdp_router_ipv4 in a dedicated thread 



In order to not miss any netlink message from the kernel, move routes
monitor to a dedicated thread.

Fixes: 85bf1f51 ("samples: bpf: Convert xdp_router_ipv4 to XDP samples helper")
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/e364b817c69ded73be24b677ab47a157f7c21b64.1649167911.git.lorenzo@kernel.org
parent 3a06ec0a

samples/bpf/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -219,7 +219,7 @@ TPROGLDLIBS_xdp_redirect += -lm 
TPROGLDLIBS_xdp_redirect_cpu	+= -lm

TPROGLDLIBS_xdp_redirect_map	+= -lm

TPROGLDLIBS_xdp_redirect_map_multi += -lm

TPROGLDLIBS_xdp_router_ipv4	+= -lm

TPROGLDLIBS_xdp_router_ipv4	+= -lm -pthread

TPROGLDLIBS_tracex4		+= -lrt

TPROGLDLIBS_trace_output	+= -lrt

TPROGLDLIBS_map_perf_test	+= -lrt

samples/bpf/xdp_router_ipv4_user.c

+54 −32
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <sys/resource.h>

#include <libgen.h>

#include <getopt.h>

#include <pthread.h>

#include "xdp_sample_user.h"

#include "xdp_router_ipv4.skel.h"
@@ -38,6 +39,9 @@ static int arp_table_map_fd; 
static int exact_match_map_fd;

static int tx_port_map_fd;



static bool routes_thread_exit;

static int interval = 5;



static int mask = SAMPLE_RX_CNT | SAMPLE_REDIRECT_ERR_MAP_CNT |

		  SAMPLE_DEVMAP_XMIT_CNT_MULTI | SAMPLE_EXCEPTION_CNT;
@@ -445,7 +449,7 @@ static int get_arp_table(int rtm_family) 
/* Function to keep track and update changes in route and arp table

 * Give regular statistics of packets forwarded

 */

static void monitor_route(void *ctx)

static void *monitor_routes_thread(void *arg)

{

	struct pollfd fds_route, fds_arp;

	struct sockaddr_nl la, lr;
@@ -455,7 +459,7 @@ static void monitor_route(void *ctx) 
	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);

	if (sock < 0) {

		fprintf(stderr, "open netlink socket: %s\n", strerror(errno));

		return;

		return NULL;

	}



	fcntl(sock, F_SETFL, O_NONBLOCK);
@@ -465,7 +469,7 @@ static void monitor_route(void *ctx) 
	if (bind(sock, (struct sockaddr *)&lr, sizeof(lr)) < 0) {

		fprintf(stderr, "bind netlink socket: %s\n", strerror(errno));

		close(sock);

		return;

		return NULL;

	}



	fds_route.fd = sock;
@@ -475,7 +479,7 @@ static void monitor_route(void *ctx) 
	if (sock_arp < 0) {

		fprintf(stderr, "open netlink socket: %s\n", strerror(errno));

		close(sock);

		return;

		return NULL;

	}



	fcntl(sock_arp, F_SETFL, O_NONBLOCK);
@@ -490,6 +494,18 @@ static void monitor_route(void *ctx) 
	fds_arp.fd = sock_arp;

	fds_arp.events = POLL_IN;



	/* dump route and arp tables */

	if (get_arp_table(AF_INET) < 0) {

		fprintf(stderr, "Failed reading arp table\n");

		goto cleanup;

	}



	if (get_route_table(AF_INET) < 0) {

		fprintf(stderr, "Failed reading route table\n");

		goto cleanup;

	}



	while (!routes_thread_exit) {

		memset(buf, 0, sizeof(buf));

		if (poll(&fds_route, 1, 3) == POLL_IN) {

			nll = recv_msg(lr, sock);
@@ -516,9 +532,13 @@ static void monitor_route(void *ctx) 
			read_arp(nh, nll);

		}



		sleep(interval);

	}



cleanup:

	close(sock_arp);

	close(sock);

	return NULL;

}



static void usage(char *argv[], const struct option *long_options,
@@ -531,10 +551,11 @@ static void usage(char *argv[], const struct option *long_options, 
int main(int argc, char **argv)

{

	bool error = true, generic = false, force = false;

	int opt, interval = 5, ret = EXIT_FAIL_BPF;

	int opt, ret = EXIT_FAIL_BPF;

	struct xdp_router_ipv4 *skel;

	int i, total_ifindex = argc - 1;

	char **ifname_list = argv + 1;

	pthread_t routes_thread;

	int longindex = 0;



	if (libbpf_set_strict_mode(LIBBPF_STRICT_ALL) < 0) {
@@ -653,24 +674,25 @@ int main(int argc, char **argv) 
			goto end_destroy;

	}



	if (get_route_table(AF_INET) < 0) {

		fprintf(stderr, "Failed reading routing table\n");

	ret = pthread_create(&routes_thread, NULL, monitor_routes_thread, NULL);

	if (ret) {

		fprintf(stderr, "Failed creating routes_thread: %s\n", strerror(-ret));

		ret = EXIT_FAIL;

		goto end_destroy;

	}



	if (get_arp_table(AF_INET) < 0) {

		fprintf(stderr, "Failed reading arptable\n");

		goto end_destroy;

	}

	ret = sample_run(interval, NULL, NULL);

	routes_thread_exit = true;



	ret = sample_run(interval, monitor_route, NULL);

	if (ret < 0) {

		fprintf(stderr, "Failed during sample run: %s\n", strerror(-ret));

		ret = EXIT_FAIL;

		goto end_destroy;

		goto end_thread_wait;

	}

	ret = EXIT_OK;



end_thread_wait:

	pthread_join(routes_thread, NULL);

end_destroy:

	xdp_router_ipv4__destroy(skel);

end: