tools/testing/selftests/net/reuseport_addr_any.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0

 /* Test that sockets listening on a specific address are preferred
  * over sockets listening on addr_any.
  */

 #define _GNU_SOURCE

 #include <arpa/inet.h>
 #include <errno.h>
 #include <error.h>
 #include <linux/dccp.h>
 #include <linux/in.h>
 #include <linux/unistd.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/epoll.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <unistd.h>

 static const char *IP4_ADDR = "127.0.0.1";
 static const char *IP6_ADDR = "::1";
 static const char *IP4_MAPPED6 = "::ffff:127.0.0.1";

 static const int PORT = 8888;

 static void build_rcv_fd(int family, int proto, int *rcv_fds, int count,
 			 const char *addr_str)
 {
 	struct sockaddr_in  addr4 = {0};
 	struct sockaddr_in6 addr6 = {0};
 	struct sockaddr *addr;
 	int opt, i, sz;

 	memset(&addr, 0, sizeof(addr));

 	switch (family) {
 	case AF_INET:
 		addr4.sin_family = family;
 		if (!addr_str)
 			addr4.sin_addr.s_addr = htonl(INADDR_ANY);
 		else if (!inet_pton(family, addr_str, &addr4.sin_addr.s_addr))
 			error(1, errno, "inet_pton failed: %s", addr_str);
 		addr4.sin_port = htons(PORT);
 		sz = sizeof(addr4);
 		addr = (struct sockaddr *)&addr4;
 		break;
 	case AF_INET6:
 		addr6.sin6_family = AF_INET6;
 		if (!addr_str)
 			addr6.sin6_addr = in6addr_any;
 		else if (!inet_pton(family, addr_str, &addr6.sin6_addr))
 			error(1, errno, "inet_pton failed: %s", addr_str);
 		addr6.sin6_port = htons(PORT);
 		sz = sizeof(addr6);
 		addr = (struct sockaddr *)&addr6;
 		break;
 	default:
 		error(1, 0, "Unsupported family %d", family);
 		/* clang does not recognize error() above as terminating
 		 * the program, so it complains that saddr, sz are
 		 * not initialized when this code path is taken. Silence it.
 		 */
 		return;
 	}

 	for (i = 0; i < count; ++i) {
 		rcv_fds[i] = socket(family, proto, 0);
 		if (rcv_fds[i] < 0)
 			error(1, errno, "failed to create receive socket");

 		opt = 1;
 		if (setsockopt(rcv_fds[i], SOL_SOCKET, SO_REUSEPORT, &opt,
 			       sizeof(opt)))
 			error(1, errno, "failed to set SO_REUSEPORT");

 		if (bind(rcv_fds[i], addr, sz))
 			error(1, errno, "failed to bind receive socket");

 		if (proto == SOCK_STREAM && listen(rcv_fds[i], 10))
 			error(1, errno, "tcp: failed to listen on receive port");
 		else if (proto == SOCK_DCCP) {
 			if (setsockopt(rcv_fds[i], SOL_DCCP,
 					DCCP_SOCKOPT_SERVICE,
 					&(int) {htonl(42)}, sizeof(int)))
 				error(1, errno, "failed to setsockopt");

 			if (listen(rcv_fds[i], 10))
 				error(1, errno, "dccp: failed to listen on receive port");
 		}
 	}
 }

 static int connect_and_send(int family, int proto)
 {
 	struct sockaddr_in  saddr4 = {0};
 	struct sockaddr_in  daddr4 = {0};
 	struct sockaddr_in6 saddr6 = {0};
 	struct sockaddr_in6 daddr6 = {0};
 	struct sockaddr *saddr, *daddr;
 	int fd, sz;

 	switch (family) {
 	case AF_INET:
 		saddr4.sin_family = AF_INET;
 		saddr4.sin_addr.s_addr = htonl(INADDR_ANY);
 		saddr4.sin_port = 0;

 		daddr4.sin_family = AF_INET;
 		if (!inet_pton(family, IP4_ADDR, &daddr4.sin_addr.s_addr))
 			error(1, errno, "inet_pton failed: %s", IP4_ADDR);
 		daddr4.sin_port = htons(PORT);

 		sz = sizeof(saddr4);
 		saddr = (struct sockaddr *)&saddr4;
 		daddr = (struct sockaddr *)&daddr4;
 	break;
 	case AF_INET6:
 		saddr6.sin6_family = AF_INET6;
 		saddr6.sin6_addr = in6addr_any;

 		daddr6.sin6_family = AF_INET6;
 		if (!inet_pton(family, IP6_ADDR, &daddr6.sin6_addr))
 			error(1, errno, "inet_pton failed: %s", IP6_ADDR);
 		daddr6.sin6_port = htons(PORT);

 		sz = sizeof(saddr6);
 		saddr = (struct sockaddr *)&saddr6;
 		daddr = (struct sockaddr *)&daddr6;
 	break;
 	default:
 		error(1, 0, "Unsupported family %d", family);
 		/* clang does not recognize error() above as terminating
 		 * the program, so it complains that saddr, daddr, sz are
 		 * not initialized when this code path is taken. Silence it.
 		 */
 		return -1;
 	}

 	fd = socket(family, proto, 0);
 	if (fd < 0)
 		error(1, errno, "failed to create send socket");

 	if (proto == SOCK_DCCP &&
 		setsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_SERVICE,
 				&(int){htonl(42)}, sizeof(int)))
 		error(1, errno, "failed to setsockopt");

 	if (bind(fd, saddr, sz))
 		error(1, errno, "failed to bind send socket");

 	if (connect(fd, daddr, sz))
 		error(1, errno, "failed to connect send socket");

 	if (send(fd, "a", 1, 0) < 0)
 		error(1, errno, "failed to send message");

 	return fd;
 }

 static int receive_once(int epfd, int proto)
 {
 	struct epoll_event ev;
 	int i, fd;
 	char buf[8];

 	i = epoll_wait(epfd, &ev, 1, 3);
 	if (i < 0)
 		error(1, errno, "epoll_wait failed");

 	if (proto == SOCK_STREAM || proto == SOCK_DCCP) {
 		fd = accept(ev.data.fd, NULL, NULL);
 		if (fd < 0)
 			error(1, errno, "failed to accept");
 		i = recv(fd, buf, sizeof(buf), 0);
 		close(fd);
 	} else {
 		i = recv(ev.data.fd, buf, sizeof(buf), 0);
 	}

 	if (i < 0)
 		error(1, errno, "failed to recv");

 	return ev.data.fd;
 }

 static void test(int *rcv_fds, int count, int family, int proto, int fd)
 {
 	struct epoll_event ev;
 	int epfd, i, send_fd, recv_fd;

 	epfd = epoll_create(1);
 	if (epfd < 0)
 		error(1, errno, "failed to create epoll");

 	ev.events = EPOLLIN;
 	for (i = 0; i < count; ++i) {
 		ev.data.fd = rcv_fds[i];
 		if (epoll_ctl(epfd, EPOLL_CTL_ADD, rcv_fds[i], &ev))
 			error(1, errno, "failed to register sock epoll");
 	}

 	send_fd = connect_and_send(family, proto);

 	recv_fd = receive_once(epfd, proto);
 	if (recv_fd != fd)
 		error(1, 0, "received on an unexpected socket");

 	close(send_fd);
 	close(epfd);
 }


 static void run_one_test(int fam_send, int fam_rcv, int proto,
 			 const char *addr_str)
 {
 	/* Below we test that a socket listening on a specific address
 	 * is always selected in preference over a socket listening
 	 * on addr_any. Bugs where this is not the case often result
 	 * in sockets created first or last to get picked. So below
 	 * we make sure that there are always addr_any sockets created
 	 * before and after a specific socket is created.
 	 */
 	int rcv_fds[10], i;

 	build_rcv_fd(AF_INET, proto, rcv_fds, 2, NULL);
 	build_rcv_fd(AF_INET6, proto, rcv_fds + 2, 2, NULL);
 	build_rcv_fd(fam_rcv, proto, rcv_fds + 4, 1, addr_str);
 	build_rcv_fd(AF_INET, proto, rcv_fds + 5, 2, NULL);
 	build_rcv_fd(AF_INET6, proto, rcv_fds + 7, 2, NULL);
 	test(rcv_fds, 9, fam_send, proto, rcv_fds[4]);
 	for (i = 0; i < 9; ++i)
 		close(rcv_fds[i]);
 	fprintf(stderr, "pass\n");
 }

 static void test_proto(int proto, const char *proto_str)
 {
 	if (proto == SOCK_DCCP) {
 		int test_fd;

 		test_fd = socket(AF_INET, proto, 0);
 		if (test_fd < 0) {
 			if (errno == ESOCKTNOSUPPORT) {
 				fprintf(stderr, "DCCP not supported: skipping DCCP tests\n");
 				return;
 			} else
 				error(1, errno, "failed to create a DCCP socket");
 		}
 		close(test_fd);
 	}

 	fprintf(stderr, "%s IPv4 ... ", proto_str);
 	run_one_test(AF_INET, AF_INET, proto, IP4_ADDR);

 	fprintf(stderr, "%s IPv6 ... ", proto_str);
 	run_one_test(AF_INET6, AF_INET6, proto, IP6_ADDR);

 	fprintf(stderr, "%s IPv4 mapped to IPv6 ... ", proto_str);
 	run_one_test(AF_INET, AF_INET6, proto, IP4_MAPPED6);
 }

 int main(void)
 {
 	test_proto(SOCK_DGRAM, "UDP");
 	test_proto(SOCK_STREAM, "TCP");
 	test_proto(SOCK_DCCP, "DCCP");

 	fprintf(stderr, "SUCCESS\n");
 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0

	/* Test that sockets listening on a specific address are preferred
	* over sockets listening on addr_any.
	*/

	#define _GNU_SOURCE

	#include <arpa/inet.h>
	#include <errno.h>
	#include <error.h>
	#include <linux/dccp.h>
	#include <linux/in.h>
	#include <linux/unistd.h>
	#include <stdbool.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/epoll.h>
	#include <sys/types.h>
	#include <sys/socket.h>
	#include <unistd.h>

	static const char *IP4_ADDR = "127.0.0.1";
	static const char *IP6_ADDR = "::1";
	static const char *IP4_MAPPED6 = "::ffff:127.0.0.1";

	static const int PORT = 8888;

	static void build_rcv_fd(int family, int proto, int *rcv_fds, int count,
	const char *addr_str)
	{
	struct sockaddr_in addr4 = {0};
	struct sockaddr_in6 addr6 = {0};
	struct sockaddr *addr;
	int opt, i, sz;

	memset(&addr, 0, sizeof(addr));

	switch (family) {
	case AF_INET:
	addr4.sin_family = family;
	if (!addr_str)
	addr4.sin_addr.s_addr = htonl(INADDR_ANY);
	else if (!inet_pton(family, addr_str, &addr4.sin_addr.s_addr))
	error(1, errno, "inet_pton failed: %s", addr_str);
	addr4.sin_port = htons(PORT);
	sz = sizeof(addr4);
	addr = (struct sockaddr *)&addr4;
	break;
	case AF_INET6:
	addr6.sin6_family = AF_INET6;
	if (!addr_str)
	addr6.sin6_addr = in6addr_any;
	else if (!inet_pton(family, addr_str, &addr6.sin6_addr))
	error(1, errno, "inet_pton failed: %s", addr_str);
	addr6.sin6_port = htons(PORT);
	sz = sizeof(addr6);
	addr = (struct sockaddr *)&addr6;
	break;
	default:
	error(1, 0, "Unsupported family %d", family);
	/* clang does not recognize error() above as terminating
	* the program, so it complains that saddr, sz are
	* not initialized when this code path is taken. Silence it.
	*/
	return;
	}

	for (i = 0; i < count; ++i) {
	rcv_fds[i] = socket(family, proto, 0);
	if (rcv_fds[i] < 0)
	error(1, errno, "failed to create receive socket");

	opt = 1;
	if (setsockopt(rcv_fds[i], SOL_SOCKET, SO_REUSEPORT, &opt,
	sizeof(opt)))
	error(1, errno, "failed to set SO_REUSEPORT");

	if (bind(rcv_fds[i], addr, sz))
	error(1, errno, "failed to bind receive socket");

	if (proto == SOCK_STREAM && listen(rcv_fds[i], 10))
	error(1, errno, "tcp: failed to listen on receive port");
	else if (proto == SOCK_DCCP) {
	if (setsockopt(rcv_fds[i], SOL_DCCP,
	DCCP_SOCKOPT_SERVICE,
	&(int) {htonl(42)}, sizeof(int)))
	error(1, errno, "failed to setsockopt");

	if (listen(rcv_fds[i], 10))
	error(1, errno, "dccp: failed to listen on receive port");
	}
	}
	}

	static int connect_and_send(int family, int proto)
	{
	struct sockaddr_in saddr4 = {0};
	struct sockaddr_in daddr4 = {0};
	struct sockaddr_in6 saddr6 = {0};
	struct sockaddr_in6 daddr6 = {0};
	struct sockaddr saddr, daddr;
	int fd, sz;

	switch (family) {
	case AF_INET:
	saddr4.sin_family = AF_INET;
	saddr4.sin_addr.s_addr = htonl(INADDR_ANY);
	saddr4.sin_port = 0;

	daddr4.sin_family = AF_INET;
	if (!inet_pton(family, IP4_ADDR, &daddr4.sin_addr.s_addr))
	error(1, errno, "inet_pton failed: %s", IP4_ADDR);
	daddr4.sin_port = htons(PORT);

	sz = sizeof(saddr4);
	saddr = (struct sockaddr *)&saddr4;
	daddr = (struct sockaddr *)&daddr4;
	break;
	case AF_INET6:
	saddr6.sin6_family = AF_INET6;
	saddr6.sin6_addr = in6addr_any;

	daddr6.sin6_family = AF_INET6;
	if (!inet_pton(family, IP6_ADDR, &daddr6.sin6_addr))
	error(1, errno, "inet_pton failed: %s", IP6_ADDR);
	daddr6.sin6_port = htons(PORT);

	sz = sizeof(saddr6);
	saddr = (struct sockaddr *)&saddr6;
	daddr = (struct sockaddr *)&daddr6;
	break;
	default:
	error(1, 0, "Unsupported family %d", family);
	/* clang does not recognize error() above as terminating
	* the program, so it complains that saddr, daddr, sz are
	* not initialized when this code path is taken. Silence it.
	*/
	return -1;
	}

	fd = socket(family, proto, 0);
	if (fd < 0)
	error(1, errno, "failed to create send socket");

	if (proto == SOCK_DCCP &&
	setsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_SERVICE,
	&(int){htonl(42)}, sizeof(int)))
	error(1, errno, "failed to setsockopt");

	if (bind(fd, saddr, sz))
	error(1, errno, "failed to bind send socket");

	if (connect(fd, daddr, sz))
	error(1, errno, "failed to connect send socket");

	if (send(fd, "a", 1, 0) < 0)
	error(1, errno, "failed to send message");

	return fd;
	}

	static int receive_once(int epfd, int proto)
	{
	struct epoll_event ev;
	int i, fd;
	char buf[8];

	i = epoll_wait(epfd, &ev, 1, 3);
	if (i < 0)
	error(1, errno, "epoll_wait failed");

	if (proto == SOCK_STREAM \|\| proto == SOCK_DCCP) {
	fd = accept(ev.data.fd, NULL, NULL);
	if (fd < 0)
	error(1, errno, "failed to accept");
	i = recv(fd, buf, sizeof(buf), 0);
	close(fd);
	} else {
	i = recv(ev.data.fd, buf, sizeof(buf), 0);
	}

	if (i < 0)
	error(1, errno, "failed to recv");

	return ev.data.fd;
	}

	static void test(int *rcv_fds, int count, int family, int proto, int fd)
	{
	struct epoll_event ev;
	int epfd, i, send_fd, recv_fd;

	epfd = epoll_create(1);
	if (epfd < 0)
	error(1, errno, "failed to create epoll");

	ev.events = EPOLLIN;
	for (i = 0; i < count; ++i) {
	ev.data.fd = rcv_fds[i];
	if (epoll_ctl(epfd, EPOLL_CTL_ADD, rcv_fds[i], &ev))
	error(1, errno, "failed to register sock epoll");
	}

	send_fd = connect_and_send(family, proto);

	recv_fd = receive_once(epfd, proto);
	if (recv_fd != fd)
	error(1, 0, "received on an unexpected socket");

	close(send_fd);
	close(epfd);
	}


	static void run_one_test(int fam_send, int fam_rcv, int proto,
	const char *addr_str)
	{
	/* Below we test that a socket listening on a specific address
	* is always selected in preference over a socket listening
	* on addr_any. Bugs where this is not the case often result
	* in sockets created first or last to get picked. So below
	* we make sure that there are always addr_any sockets created
	* before and after a specific socket is created.
	*/
	int rcv_fds[10], i;

	build_rcv_fd(AF_INET, proto, rcv_fds, 2, NULL);
	build_rcv_fd(AF_INET6, proto, rcv_fds + 2, 2, NULL);
	build_rcv_fd(fam_rcv, proto, rcv_fds + 4, 1, addr_str);
	build_rcv_fd(AF_INET, proto, rcv_fds + 5, 2, NULL);
	build_rcv_fd(AF_INET6, proto, rcv_fds + 7, 2, NULL);
	test(rcv_fds, 9, fam_send, proto, rcv_fds[4]);
	for (i = 0; i < 9; ++i)
	close(rcv_fds[i]);
	fprintf(stderr, "pass\n");
	}

	static void test_proto(int proto, const char *proto_str)
	{
	if (proto == SOCK_DCCP) {
	int test_fd;

	test_fd = socket(AF_INET, proto, 0);
	if (test_fd < 0) {
	if (errno == ESOCKTNOSUPPORT) {
	fprintf(stderr, "DCCP not supported: skipping DCCP tests\n");
	return;
	} else
	error(1, errno, "failed to create a DCCP socket");
	}
	close(test_fd);
	}

	fprintf(stderr, "%s IPv4 ... ", proto_str);
	run_one_test(AF_INET, AF_INET, proto, IP4_ADDR);

	fprintf(stderr, "%s IPv6 ... ", proto_str);
	run_one_test(AF_INET6, AF_INET6, proto, IP6_ADDR);

	fprintf(stderr, "%s IPv4 mapped to IPv6 ... ", proto_str);
	run_one_test(AF_INET, AF_INET6, proto, IP4_MAPPED6);
	}

	int main(void)
	{
	test_proto(SOCK_DGRAM, "UDP");
	test_proto(SOCK_STREAM, "TCP");
	test_proto(SOCK_DCCP, "DCCP");

	fprintf(stderr, "SUCCESS\n");
	return 0;
	}