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

 // SPDX-License-Identifier: GPL-2.0

 /*
  * Test key rotation for TFO.
  * New keys are 'rotated' in two steps:
  * 1) Add new key as the 'backup' key 'behind' the primary key
  * 2) Make new key the primary by swapping the backup and primary keys
  *
  * The rotation is done in stages using multiple sockets bound
  * to the same port via SO_REUSEPORT. This simulates key rotation
  * behind say a load balancer. We verify that across the rotation
  * there are no cases in which a cookie is not accepted by verifying
  * that TcpExtTCPFastOpenPassiveFail remains 0.
  */
 #define _GNU_SOURCE
 #include <arpa/inet.h>
 #include <errno.h>
 #include <error.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/epoll.h>
 #include <unistd.h>
 #include <netinet/tcp.h>
 #include <fcntl.h>
 #include <time.h>

 #ifndef TCP_FASTOPEN_KEY
 #define TCP_FASTOPEN_KEY 33
 #endif

 #define N_LISTEN 10
 #define PROC_FASTOPEN_KEY "/proc/sys/net/ipv4/tcp_fastopen_key"
 #define KEY_LENGTH 16

 #ifndef ARRAY_SIZE
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
 #endif

 static bool do_ipv6;
 static bool do_sockopt;
 static bool do_rotate;
 static int key_len = KEY_LENGTH;
 static int rcv_fds[N_LISTEN];
 static int proc_fd;
 static const char *IP4_ADDR = "127.0.0.1";
 static const char *IP6_ADDR = "::1";
 static const int PORT = 8891;

 static void get_keys(int fd, uint32_t *keys)
 {
 	char buf[128];
 	socklen_t len = KEY_LENGTH * 2;

 	if (do_sockopt) {
 		if (getsockopt(fd, SOL_TCP, TCP_FASTOPEN_KEY, keys, &len))
 			error(1, errno, "Unable to get key");
 		return;
 	}
 	lseek(proc_fd, 0, SEEK_SET);
 	if (read(proc_fd, buf, sizeof(buf)) <= 0)
 		error(1, errno, "Unable to read %s", PROC_FASTOPEN_KEY);
 	if (sscanf(buf, "%x-%x-%x-%x,%x-%x-%x-%x", keys, keys + 1, keys + 2,
 	    keys + 3, keys + 4, keys + 5, keys + 6, keys + 7) != 8)
 		error(1, 0, "Unable to parse %s", PROC_FASTOPEN_KEY);
 }

 static void set_keys(int fd, uint32_t *keys)
 {
 	char buf[128];

 	if (do_sockopt) {
 		if (setsockopt(fd, SOL_TCP, TCP_FASTOPEN_KEY, keys,
 		    key_len))
 			error(1, errno, "Unable to set key");
 		return;
 	}
 	if (do_rotate)
 		snprintf(buf, 128, "%08x-%08x-%08x-%08x,%08x-%08x-%08x-%08x",
 			 keys[0], keys[1], keys[2], keys[3], keys[4], keys[5],
 			 keys[6], keys[7]);
 	else
 		snprintf(buf, 128, "%08x-%08x-%08x-%08x",
 			 keys[0], keys[1], keys[2], keys[3]);
 	lseek(proc_fd, 0, SEEK_SET);
 	if (write(proc_fd, buf, sizeof(buf)) <= 0)
 		error(1, errno, "Unable to write %s", PROC_FASTOPEN_KEY);
 }

 static void build_rcv_fd(int family, int proto, int *rcv_fds)
 {
 	struct sockaddr_in  addr4 = {0};
 	struct sockaddr_in6 addr6 = {0};
 	struct sockaddr *addr;
 	int opt = 1, i, sz;
 	int qlen = 100;
 	uint32_t keys[8];

 	switch (family) {
 	case AF_INET:
 		addr4.sin_family = family;
 		addr4.sin_addr.s_addr = htonl(INADDR_ANY);
 		addr4.sin_port = htons(PORT);
 		sz = sizeof(addr4);
 		addr = (struct sockaddr *)&addr4;
 		break;
 	case AF_INET6:
 		addr6.sin6_family = AF_INET6;
 		addr6.sin6_addr = in6addr_any;
 		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 < ARRAY_SIZE(keys); i++)
 		keys[i] = rand();
 	for (i = 0; i < N_LISTEN; i++) {
 		rcv_fds[i] = socket(family, proto, 0);
 		if (rcv_fds[i] < 0)
 			error(1, errno, "failed to create receive socket");
 		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 (setsockopt(rcv_fds[i], SOL_TCP, TCP_FASTOPEN, &qlen,
 			       sizeof(qlen)))
 			error(1, errno, "failed to set TCP_FASTOPEN");
 		set_keys(rcv_fds[i], keys);
 		if (proto == SOCK_STREAM && listen(rcv_fds[i], 10))
 			error(1, errno, "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, ret;
 	char data[1];

 	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 (bind(fd, saddr, sz))
 		error(1, errno, "failed to bind send socket");
 	data[0] = 'a';
 	ret = sendto(fd, data, 1, MSG_FASTOPEN, daddr, sz);
 	if (ret != 1)
 		error(1, errno, "failed to sendto");

 	return fd;
 }

 static bool is_listen_fd(int fd)
 {
 	int i;

 	for (i = 0; i < N_LISTEN; i++) {
 		if (rcv_fds[i] == fd)
 			return true;
 	}
 	return false;
 }

 static void rotate_key(int fd)
 {
 	static int iter;
 	static uint32_t new_key[4];
 	uint32_t keys[8];
 	uint32_t tmp_key[4];
 	int i;

 	if (iter < N_LISTEN) {
 		/* first set new key as backups */
 		if (iter == 0) {
 			for (i = 0; i < ARRAY_SIZE(new_key); i++)
 				new_key[i] = rand();
 		}
 		get_keys(fd, keys);
 		memcpy(keys + 4, new_key, KEY_LENGTH);
 		set_keys(fd, keys);
 	} else {
 		/* swap the keys */
 		get_keys(fd, keys);
 		memcpy(tmp_key, keys + 4, KEY_LENGTH);
 		memcpy(keys + 4, keys, KEY_LENGTH);
 		memcpy(keys, tmp_key, KEY_LENGTH);
 		set_keys(fd, keys);
 	}
 	if (++iter >= (N_LISTEN * 2))
 		iter = 0;
 }

 static void run_one_test(int family)
 {
 	struct epoll_event ev;
 	int i, send_fd;
 	int n_loops = 10000;
 	int rotate_key_fd = 0;
 	int key_rotate_interval = 50;
 	int fd, epfd;
 	char buf[1];

 	build_rcv_fd(family, SOCK_STREAM, rcv_fds);
 	epfd = epoll_create(1);
 	if (epfd < 0)
 		error(1, errno, "failed to create epoll");
 	ev.events = EPOLLIN;
 	for (i = 0; i < N_LISTEN; 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");
 	}
 	while (n_loops--) {
 		send_fd = connect_and_send(family, SOCK_STREAM);
 		if (do_rotate && ((n_loops % key_rotate_interval) == 0)) {
 			rotate_key(rcv_fds[rotate_key_fd]);
 			if (++rotate_key_fd >= N_LISTEN)
 				rotate_key_fd = 0;
 		}
 		while (1) {
 			i = epoll_wait(epfd, &ev, 1, -1);
 			if (i < 0)
 				error(1, errno, "epoll_wait failed");
 			if (is_listen_fd(ev.data.fd)) {
 				fd = accept(ev.data.fd, NULL, NULL);
 				if (fd < 0)
 					error(1, errno, "failed to accept");
 				ev.data.fd = fd;
 				if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev))
 					error(1, errno, "failed epoll add");
 				continue;
 			}
 			i = recv(ev.data.fd, buf, sizeof(buf), 0);
 			if (i != 1)
 				error(1, errno, "failed recv data");
 			if (epoll_ctl(epfd, EPOLL_CTL_DEL, ev.data.fd, NULL))
 				error(1, errno, "failed epoll del");
 			close(ev.data.fd);
 			break;
 		}
 		close(send_fd);
 	}
 	for (i = 0; i < N_LISTEN; i++)
 		close(rcv_fds[i]);
 }

 static void parse_opts(int argc, char **argv)
 {
 	int c;

 	while ((c = getopt(argc, argv, "46sr")) != -1) {
 		switch (c) {
 		case '4':
 			do_ipv6 = false;
 			break;
 		case '6':
 			do_ipv6 = true;
 			break;
 		case 's':
 			do_sockopt = true;
 			break;
 		case 'r':
 			do_rotate = true;
 			key_len = KEY_LENGTH * 2;
 			break;
 		default:
 			error(1, 0, "%s: parse error", argv[0]);
 		}
 	}
 }

 int main(int argc, char **argv)
 {
 	parse_opts(argc, argv);
 	proc_fd = open(PROC_FASTOPEN_KEY, O_RDWR);
 	if (proc_fd < 0)
 		error(1, errno, "Unable to open %s", PROC_FASTOPEN_KEY);
 	srand(time(NULL));
 	if (do_ipv6)
 		run_one_test(AF_INET6);
 	else
 		run_one_test(AF_INET);
 	close(proc_fd);
 	fprintf(stderr, "PASS\n");
 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0

	/*
	* Test key rotation for TFO.
	* New keys are 'rotated' in two steps:
	* 1) Add new key as the 'backup' key 'behind' the primary key
	* 2) Make new key the primary by swapping the backup and primary keys
	*
	* The rotation is done in stages using multiple sockets bound
	* to the same port via SO_REUSEPORT. This simulates key rotation
	* behind say a load balancer. We verify that across the rotation
	* there are no cases in which a cookie is not accepted by verifying
	* that TcpExtTCPFastOpenPassiveFail remains 0.
	*/
	#define _GNU_SOURCE
	#include <arpa/inet.h>
	#include <errno.h>
	#include <error.h>
	#include <stdbool.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/epoll.h>
	#include <unistd.h>
	#include <netinet/tcp.h>
	#include <fcntl.h>
	#include <time.h>

	#ifndef TCP_FASTOPEN_KEY
	#define TCP_FASTOPEN_KEY 33
	#endif

	#define N_LISTEN 10
	#define PROC_FASTOPEN_KEY "/proc/sys/net/ipv4/tcp_fastopen_key"
	#define KEY_LENGTH 16

	#ifndef ARRAY_SIZE
	#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
	#endif

	static bool do_ipv6;
	static bool do_sockopt;
	static bool do_rotate;
	static int key_len = KEY_LENGTH;
	static int rcv_fds[N_LISTEN];
	static int proc_fd;
	static const char *IP4_ADDR = "127.0.0.1";
	static const char *IP6_ADDR = "::1";
	static const int PORT = 8891;

	static void get_keys(int fd, uint32_t *keys)
	{
	char buf[128];
	socklen_t len = KEY_LENGTH * 2;

	if (do_sockopt) {
	if (getsockopt(fd, SOL_TCP, TCP_FASTOPEN_KEY, keys, &len))
	error(1, errno, "Unable to get key");
	return;
	}
	lseek(proc_fd, 0, SEEK_SET);
	if (read(proc_fd, buf, sizeof(buf)) <= 0)
	error(1, errno, "Unable to read %s", PROC_FASTOPEN_KEY);
	if (sscanf(buf, "%x-%x-%x-%x,%x-%x-%x-%x", keys, keys + 1, keys + 2,
	keys + 3, keys + 4, keys + 5, keys + 6, keys + 7) != 8)
	error(1, 0, "Unable to parse %s", PROC_FASTOPEN_KEY);
	}

	static void set_keys(int fd, uint32_t *keys)
	{
	char buf[128];

	if (do_sockopt) {
	if (setsockopt(fd, SOL_TCP, TCP_FASTOPEN_KEY, keys,
	key_len))
	error(1, errno, "Unable to set key");
	return;
	}
	if (do_rotate)
	snprintf(buf, 128, "%08x-%08x-%08x-%08x,%08x-%08x-%08x-%08x",
	keys[0], keys[1], keys[2], keys[3], keys[4], keys[5],
	keys[6], keys[7]);
	else
	snprintf(buf, 128, "%08x-%08x-%08x-%08x",
	keys[0], keys[1], keys[2], keys[3]);
	lseek(proc_fd, 0, SEEK_SET);
	if (write(proc_fd, buf, sizeof(buf)) <= 0)
	error(1, errno, "Unable to write %s", PROC_FASTOPEN_KEY);
	}

	static void build_rcv_fd(int family, int proto, int *rcv_fds)
	{
	struct sockaddr_in addr4 = {0};
	struct sockaddr_in6 addr6 = {0};
	struct sockaddr *addr;
	int opt = 1, i, sz;
	int qlen = 100;
	uint32_t keys[8];

	switch (family) {
	case AF_INET:
	addr4.sin_family = family;
	addr4.sin_addr.s_addr = htonl(INADDR_ANY);
	addr4.sin_port = htons(PORT);
	sz = sizeof(addr4);
	addr = (struct sockaddr *)&addr4;
	break;
	case AF_INET6:
	addr6.sin6_family = AF_INET6;
	addr6.sin6_addr = in6addr_any;
	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 < ARRAY_SIZE(keys); i++)
	keys[i] = rand();
	for (i = 0; i < N_LISTEN; i++) {
	rcv_fds[i] = socket(family, proto, 0);
	if (rcv_fds[i] < 0)
	error(1, errno, "failed to create receive socket");
	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 (setsockopt(rcv_fds[i], SOL_TCP, TCP_FASTOPEN, &qlen,
	sizeof(qlen)))
	error(1, errno, "failed to set TCP_FASTOPEN");
	set_keys(rcv_fds[i], keys);
	if (proto == SOCK_STREAM && listen(rcv_fds[i], 10))
	error(1, errno, "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, ret;
	char data[1];

	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 (bind(fd, saddr, sz))
	error(1, errno, "failed to bind send socket");
	data[0] = 'a';
	ret = sendto(fd, data, 1, MSG_FASTOPEN, daddr, sz);
	if (ret != 1)
	error(1, errno, "failed to sendto");

	return fd;
	}

	static bool is_listen_fd(int fd)
	{
	int i;

	for (i = 0; i < N_LISTEN; i++) {
	if (rcv_fds[i] == fd)
	return true;
	}
	return false;
	}

	static void rotate_key(int fd)
	{
	static int iter;
	static uint32_t new_key[4];
	uint32_t keys[8];
	uint32_t tmp_key[4];
	int i;

	if (iter < N_LISTEN) {
	/* first set new key as backups */
	if (iter == 0) {
	for (i = 0; i < ARRAY_SIZE(new_key); i++)
	new_key[i] = rand();
	}
	get_keys(fd, keys);
	memcpy(keys + 4, new_key, KEY_LENGTH);
	set_keys(fd, keys);
	} else {
	/* swap the keys */
	get_keys(fd, keys);
	memcpy(tmp_key, keys + 4, KEY_LENGTH);
	memcpy(keys + 4, keys, KEY_LENGTH);
	memcpy(keys, tmp_key, KEY_LENGTH);
	set_keys(fd, keys);
	}
	if (++iter >= (N_LISTEN * 2))
	iter = 0;
	}

	static void run_one_test(int family)
	{
	struct epoll_event ev;
	int i, send_fd;
	int n_loops = 10000;
	int rotate_key_fd = 0;
	int key_rotate_interval = 50;
	int fd, epfd;
	char buf[1];

	build_rcv_fd(family, SOCK_STREAM, rcv_fds);
	epfd = epoll_create(1);
	if (epfd < 0)
	error(1, errno, "failed to create epoll");
	ev.events = EPOLLIN;
	for (i = 0; i < N_LISTEN; 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");
	}
	while (n_loops--) {
	send_fd = connect_and_send(family, SOCK_STREAM);
	if (do_rotate && ((n_loops % key_rotate_interval) == 0)) {
	rotate_key(rcv_fds[rotate_key_fd]);
	if (++rotate_key_fd >= N_LISTEN)
	rotate_key_fd = 0;
	}
	while (1) {
	i = epoll_wait(epfd, &ev, 1, -1);
	if (i < 0)
	error(1, errno, "epoll_wait failed");
	if (is_listen_fd(ev.data.fd)) {
	fd = accept(ev.data.fd, NULL, NULL);
	if (fd < 0)
	error(1, errno, "failed to accept");
	ev.data.fd = fd;
	if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &ev))
	error(1, errno, "failed epoll add");
	continue;
	}
	i = recv(ev.data.fd, buf, sizeof(buf), 0);
	if (i != 1)
	error(1, errno, "failed recv data");
	if (epoll_ctl(epfd, EPOLL_CTL_DEL, ev.data.fd, NULL))
	error(1, errno, "failed epoll del");
	close(ev.data.fd);
	break;
	}
	close(send_fd);
	}
	for (i = 0; i < N_LISTEN; i++)
	close(rcv_fds[i]);
	}

	static void parse_opts(int argc, char **argv)
	{
	int c;

	while ((c = getopt(argc, argv, "46sr")) != -1) {
	switch (c) {
	case '4':
	do_ipv6 = false;
	break;
	case '6':
	do_ipv6 = true;
	break;
	case 's':
	do_sockopt = true;
	break;
	case 'r':
	do_rotate = true;
	key_len = KEY_LENGTH * 2;
	break;
	default:
	error(1, 0, "%s: parse error", argv[0]);
	}
	}
	}

	int main(int argc, char **argv)
	{
	parse_opts(argc, argv);
	proc_fd = open(PROC_FASTOPEN_KEY, O_RDWR);
	if (proc_fd < 0)
	error(1, errno, "Unable to open %s", PROC_FASTOPEN_KEY);
	srand(time(NULL));
	if (do_ipv6)
	run_one_test(AF_INET6);
	else
	run_one_test(AF_INET);
	close(proc_fd);
	fprintf(stderr, "PASS\n");
	return 0;
	}