From 10fbcdd12aa24fdb4b357a39abc03686d15f04fd Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Wed, 29 May 2019 12:34:01 -0400 Subject: [PATCH] selftests/net: add TFO key rotation selftest Demonstrate how the primary and backup TFO keys can be rotated while minimizing the number of client cookies that are rejected. Signed-off-by: Jason Baron Signed-off-by: Christoph Paasch Acked-by: Yuchung Cheng Signed-off-by: David S. Miller --- tools/testing/selftests/net/.gitignore | 1 + tools/testing/selftests/net/Makefile | 2 + .../selftests/net/tcp_fastopen_backup_key.c | 336 ++++++++++++++++++ .../selftests/net/tcp_fastopen_backup_key.sh | 55 +++ 4 files changed, 394 insertions(+) create mode 100644 tools/testing/selftests/net/tcp_fastopen_backup_key.c create mode 100755 tools/testing/selftests/net/tcp_fastopen_backup_key.sh diff --git a/tools/testing/selftests/net/.gitignore b/tools/testing/selftests/net/.gitignore index 99a4e41d5249..4ce0bc1612f5 100644 --- a/tools/testing/selftests/net/.gitignore +++ b/tools/testing/selftests/net/.gitignore @@ -20,3 +20,4 @@ ip_defrag so_txtime flowlabel flowlabel_mgr +tcp_fastopen_backup_key diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index 8343fb9d8a46..9a275d932fd5 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -10,12 +10,14 @@ TEST_PROGS += fib_tests.sh fib-onlink-tests.sh pmtu.sh udpgso.sh ip_defrag.sh TEST_PROGS += udpgso_bench.sh fib_rule_tests.sh msg_zerocopy.sh psock_snd.sh TEST_PROGS += udpgro_bench.sh udpgro.sh test_vxlan_under_vrf.sh reuseport_addr_any.sh TEST_PROGS += test_vxlan_fdb_changelink.sh so_txtime.sh ipv6_flowlabel.sh +TEST_PROGS += tcp_fastopen_backup_key.sh TEST_PROGS_EXTENDED := in_netns.sh TEST_GEN_FILES = socket TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy reuseport_addr_any TEST_GEN_FILES += tcp_mmap tcp_inq psock_snd txring_overwrite TEST_GEN_FILES += udpgso udpgso_bench_tx udpgso_bench_rx ip_defrag TEST_GEN_FILES += so_txtime ipv6_flowlabel ipv6_flowlabel_mgr +TEST_GEN_FILES += tcp_fastopen_backup_key TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls diff --git a/tools/testing/selftests/net/tcp_fastopen_backup_key.c b/tools/testing/selftests/net/tcp_fastopen_backup_key.c new file mode 100644 index 000000000000..58bb77d9e7e1 --- /dev/null +++ b/tools/testing/selftests/net/tcp_fastopen_backup_key.c @@ -0,0 +1,336 @@ +// 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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]; + int 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 int rotate_key(int fd) +{ + static int iter; + static uint32_t new_key[4]; + uint32_t keys[8]; + uint32_t tmp_key[4]; + int i; + int len = KEY_LENGTH * 2; + + 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; +} diff --git a/tools/testing/selftests/net/tcp_fastopen_backup_key.sh b/tools/testing/selftests/net/tcp_fastopen_backup_key.sh new file mode 100755 index 000000000000..41476399e184 --- /dev/null +++ b/tools/testing/selftests/net/tcp_fastopen_backup_key.sh @@ -0,0 +1,55 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# +# rotate TFO keys for ipv4/ipv6 and verify that the client does +# not present an invalid cookie. + +set +x +set -e + +readonly NETNS="ns-$(mktemp -u XXXXXX)" + +setup() { + ip netns add "${NETNS}" + ip -netns "${NETNS}" link set lo up + ip netns exec "${NETNS}" sysctl -w net.ipv4.tcp_fastopen=3 \ + >/dev/null 2>&1 +} + +cleanup() { + ip netns del "${NETNS}" +} + +trap cleanup EXIT +setup + +do_test() { + # flush routes before each run, otherwise successive runs can + # initially present an old TFO cookie + ip netns exec "${NETNS}" ip tcp_metrics flush + ip netns exec "${NETNS}" ./tcp_fastopen_backup_key "$1" + val=$(ip netns exec "${NETNS}" nstat -az | \ + grep TcpExtTCPFastOpenPassiveFail | awk '{print $2}') + if [ $val -ne 0 ]; then + echo "FAIL: TcpExtTCPFastOpenPassiveFail non-zero" + return 1 + fi +} + +do_test "-4" +do_test "-6" +do_test "-4" +do_test "-6" +do_test "-4s" +do_test "-6s" +do_test "-4s" +do_test "-6s" +do_test "-4r" +do_test "-6r" +do_test "-4r" +do_test "-6r" +do_test "-4sr" +do_test "-6sr" +do_test "-4sr" +do_test "-6sr" +echo "all tests done"