// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause // Copyright (c) 2020 Cloudflare /* * Test BPF attach point for INET socket lookup (BPF_SK_LOOKUP). * * Tests exercise: * - attaching/detaching/querying programs to BPF_SK_LOOKUP hook, * - redirecting socket lookup to a socket selected by BPF program, * - failing a socket lookup on BPF program's request, * - error scenarios for selecting a socket from BPF program, * - accessing BPF program context, * - attaching and running multiple BPF programs. * * Tests run in a dedicated network namespace. */ #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include "test_progs.h" #include "bpf_rlimit.h" #include "bpf_util.h" #include "cgroup_helpers.h" #include "network_helpers.h" #include "testing_helpers.h" #include "test_sk_lookup.skel.h" /* External (address, port) pairs the client sends packets to. */ #define EXT_IP4 "127.0.0.1" #define EXT_IP6 "fd00::1" #define EXT_PORT 7007 /* Internal (address, port) pairs the server listens/receives at. */ #define INT_IP4 "127.0.0.2" #define INT_IP4_V6 "::ffff:127.0.0.2" #define INT_IP6 "fd00::2" #define INT_PORT 8008 #define IO_TIMEOUT_SEC 3 enum server { SERVER_A = 0, SERVER_B = 1, MAX_SERVERS, }; enum { PROG1 = 0, PROG2, }; struct inet_addr { const char *ip; unsigned short port; }; struct test { const char *desc; struct bpf_program *lookup_prog; struct bpf_program *reuseport_prog; struct bpf_map *sock_map; int sotype; struct inet_addr connect_to; struct inet_addr listen_at; enum server accept_on; bool reuseport_has_conns; /* Add a connected socket to reuseport group */ }; static __u32 duration; /* for CHECK macro */ static bool is_ipv6(const char *ip) { return !!strchr(ip, ':'); } static int attach_reuseport(int sock_fd, struct bpf_program *reuseport_prog) { int err, prog_fd; prog_fd = bpf_program__fd(reuseport_prog); if (prog_fd < 0) { errno = -prog_fd; return -1; } err = setsockopt(sock_fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, &prog_fd, sizeof(prog_fd)); if (err) return -1; return 0; } static socklen_t inetaddr_len(const struct sockaddr_storage *addr) { return (addr->ss_family == AF_INET ? sizeof(struct sockaddr_in) : addr->ss_family == AF_INET6 ? sizeof(struct sockaddr_in6) : 0); } static int make_socket(int sotype, const char *ip, int port, struct sockaddr_storage *addr) { struct timeval timeo = { .tv_sec = IO_TIMEOUT_SEC }; int err, family, fd; family = is_ipv6(ip) ? AF_INET6 : AF_INET; err = make_sockaddr(family, ip, port, addr, NULL); if (CHECK(err, "make_address", "failed\n")) return -1; fd = socket(addr->ss_family, sotype, 0); if (CHECK(fd < 0, "socket", "failed\n")) { log_err("failed to make socket"); return -1; } err = setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo)); if (CHECK(err, "setsockopt(SO_SNDTIMEO)", "failed\n")) { log_err("failed to set SNDTIMEO"); close(fd); return -1; } err = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo)); if (CHECK(err, "setsockopt(SO_RCVTIMEO)", "failed\n")) { log_err("failed to set RCVTIMEO"); close(fd); return -1; } return fd; } static int make_server(int sotype, const char *ip, int port, struct bpf_program *reuseport_prog) { struct sockaddr_storage addr = {0}; const int one = 1; int err, fd = -1; fd = make_socket(sotype, ip, port, &addr); if (fd < 0) return -1; /* Enabled for UDPv6 sockets for IPv4-mapped IPv6 to work. */ if (sotype == SOCK_DGRAM) { err = setsockopt(fd, SOL_IP, IP_RECVORIGDSTADDR, &one, sizeof(one)); if (CHECK(err, "setsockopt(IP_RECVORIGDSTADDR)", "failed\n")) { log_err("failed to enable IP_RECVORIGDSTADDR"); goto fail; } } if (sotype == SOCK_DGRAM && addr.ss_family == AF_INET6) { err = setsockopt(fd, SOL_IPV6, IPV6_RECVORIGDSTADDR, &one, sizeof(one)); if (CHECK(err, "setsockopt(IPV6_RECVORIGDSTADDR)", "failed\n")) { log_err("failed to enable IPV6_RECVORIGDSTADDR"); goto fail; } } if (sotype == SOCK_STREAM) { err = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); if (CHECK(err, "setsockopt(SO_REUSEADDR)", "failed\n")) { log_err("failed to enable SO_REUSEADDR"); goto fail; } } if (reuseport_prog) { err = setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)); if (CHECK(err, "setsockopt(SO_REUSEPORT)", "failed\n")) { log_err("failed to enable SO_REUSEPORT"); goto fail; } } err = bind(fd, (void *)&addr, inetaddr_len(&addr)); if (CHECK(err, "bind", "failed\n")) { log_err("failed to bind listen socket"); goto fail; } if (sotype == SOCK_STREAM) { err = listen(fd, SOMAXCONN); if (CHECK(err, "make_server", "listen")) { log_err("failed to listen on port %d", port); goto fail; } } /* Late attach reuseport prog so we can have one init path */ if (reuseport_prog) { err = attach_reuseport(fd, reuseport_prog); if (CHECK(err, "attach_reuseport", "failed\n")) { log_err("failed to attach reuseport prog"); goto fail; } } return fd; fail: close(fd); return -1; } static int make_client(int sotype, const char *ip, int port) { struct sockaddr_storage addr = {0}; int err, fd; fd = make_socket(sotype, ip, port, &addr); if (fd < 0) return -1; err = connect(fd, (void *)&addr, inetaddr_len(&addr)); if (CHECK(err, "make_client", "connect")) { log_err("failed to connect client socket"); goto fail; } return fd; fail: close(fd); return -1; } static int send_byte(int fd) { ssize_t n; errno = 0; n = send(fd, "a", 1, 0); if (CHECK(n <= 0, "send_byte", "send")) { log_err("failed/partial send"); return -1; } return 0; } static int recv_byte(int fd) { char buf[1]; ssize_t n; n = recv(fd, buf, sizeof(buf), 0); if (CHECK(n <= 0, "recv_byte", "recv")) { log_err("failed/partial recv"); return -1; } return 0; } static int tcp_recv_send(int server_fd) { char buf[1]; int ret, fd; ssize_t n; fd = accept(server_fd, NULL, NULL); if (CHECK(fd < 0, "accept", "failed\n")) { log_err("failed to accept"); return -1; } n = recv(fd, buf, sizeof(buf), 0); if (CHECK(n <= 0, "recv", "failed\n")) { log_err("failed/partial recv"); ret = -1; goto close; } n = send(fd, buf, n, 0); if (CHECK(n <= 0, "send", "failed\n")) { log_err("failed/partial send"); ret = -1; goto close; } ret = 0; close: close(fd); return ret; } static void v4_to_v6(struct sockaddr_storage *ss) { struct sockaddr_in6 *v6 = (struct sockaddr_in6 *)ss; struct sockaddr_in v4 = *(struct sockaddr_in *)ss; v6->sin6_family = AF_INET6; v6->sin6_port = v4.sin_port; v6->sin6_addr.s6_addr[10] = 0xff; v6->sin6_addr.s6_addr[11] = 0xff; memcpy(&v6->sin6_addr.s6_addr[12], &v4.sin_addr.s_addr, 4); } static int udp_recv_send(int server_fd) { char cmsg_buf[CMSG_SPACE(sizeof(struct sockaddr_storage))]; struct sockaddr_storage _src_addr = { 0 }; struct sockaddr_storage *src_addr = &_src_addr; struct sockaddr_storage *dst_addr = NULL; struct msghdr msg = { 0 }; struct iovec iov = { 0 }; struct cmsghdr *cm; char buf[1]; int ret, fd; ssize_t n; iov.iov_base = buf; iov.iov_len = sizeof(buf); msg.msg_name = src_addr; msg.msg_namelen = sizeof(*src_addr); msg.msg_iov = &iov; msg.msg_iovlen = 1; msg.msg_control = cmsg_buf; msg.msg_controllen = sizeof(cmsg_buf); errno = 0; n = recvmsg(server_fd, &msg, 0); if (CHECK(n <= 0, "recvmsg", "failed\n")) { log_err("failed to receive"); return -1; } if (CHECK(msg.msg_flags & MSG_CTRUNC, "recvmsg", "truncated cmsg\n")) return -1; for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm)) { if ((cm->cmsg_level == SOL_IP && cm->cmsg_type == IP_ORIGDSTADDR) || (cm->cmsg_level == SOL_IPV6 && cm->cmsg_type == IPV6_ORIGDSTADDR)) { dst_addr = (struct sockaddr_storage *)CMSG_DATA(cm); break; } log_err("warning: ignored cmsg at level %d type %d", cm->cmsg_level, cm->cmsg_type); } if (CHECK(!dst_addr, "recvmsg", "missing ORIGDSTADDR\n")) return -1; /* Server socket bound to IPv4-mapped IPv6 address */ if (src_addr->ss_family == AF_INET6 && dst_addr->ss_family == AF_INET) { v4_to_v6(dst_addr); } /* Reply from original destination address. */ fd = socket(dst_addr->ss_family, SOCK_DGRAM, 0); if (CHECK(fd < 0, "socket", "failed\n")) { log_err("failed to create tx socket"); return -1; } ret = bind(fd, (struct sockaddr *)dst_addr, sizeof(*dst_addr)); if (CHECK(ret, "bind", "failed\n")) { log_err("failed to bind tx socket"); goto out; } msg.msg_control = NULL; msg.msg_controllen = 0; n = sendmsg(fd, &msg, 0); if (CHECK(n <= 0, "sendmsg", "failed\n")) { log_err("failed to send echo reply"); ret = -1; goto out; } ret = 0; out: close(fd); return ret; } static int tcp_echo_test(int client_fd, int server_fd) { int err; err = send_byte(client_fd); if (err) return -1; err = tcp_recv_send(server_fd); if (err) return -1; err = recv_byte(client_fd); if (err) return -1; return 0; } static int udp_echo_test(int client_fd, int server_fd) { int err; err = send_byte(client_fd); if (err) return -1; err = udp_recv_send(server_fd); if (err) return -1; err = recv_byte(client_fd); if (err) return -1; return 0; } static struct bpf_link *attach_lookup_prog(struct bpf_program *prog) { struct bpf_link *link; int net_fd; net_fd = open("/proc/self/ns/net", O_RDONLY); if (CHECK(net_fd < 0, "open", "failed\n")) { log_err("failed to open /proc/self/ns/net"); return NULL; } link = bpf_program__attach_netns(prog, net_fd); if (CHECK(IS_ERR(link), "bpf_program__attach_netns", "failed\n")) { errno = -PTR_ERR(link); log_err("failed to attach program '%s' to netns", bpf_program__name(prog)); link = NULL; } close(net_fd); return link; } static int update_lookup_map(struct bpf_map *map, int index, int sock_fd) { int err, map_fd; uint64_t value; map_fd = bpf_map__fd(map); if (CHECK(map_fd < 0, "bpf_map__fd", "failed\n")) { errno = -map_fd; log_err("failed to get map FD"); return -1; } value = (uint64_t)sock_fd; err = bpf_map_update_elem(map_fd, &index, &value, BPF_NOEXIST); if (CHECK(err, "bpf_map_update_elem", "failed\n")) { log_err("failed to update redir_map @ %d", index); return -1; } return 0; } static void query_lookup_prog(struct test_sk_lookup *skel) { struct bpf_link *link[3] = {}; struct bpf_link_info info; __u32 attach_flags = 0; __u32 prog_ids[3] = {}; __u32 prog_cnt = 3; __u32 prog_id; int net_fd; int err; net_fd = open("/proc/self/ns/net", O_RDONLY); if (CHECK(net_fd < 0, "open", "failed\n")) { log_err("failed to open /proc/self/ns/net"); return; } link[0] = attach_lookup_prog(skel->progs.lookup_pass); if (!link[0]) goto close; link[1] = attach_lookup_prog(skel->progs.lookup_pass); if (!link[1]) goto detach; link[2] = attach_lookup_prog(skel->progs.lookup_drop); if (!link[2]) goto detach; err = bpf_prog_query(net_fd, BPF_SK_LOOKUP, 0 /* query flags */, &attach_flags, prog_ids, &prog_cnt); if (CHECK(err, "bpf_prog_query", "failed\n")) { log_err("failed to query lookup prog"); goto detach; } errno = 0; if (CHECK(attach_flags != 0, "bpf_prog_query", "wrong attach_flags on query: %u", attach_flags)) goto detach; if (CHECK(prog_cnt != 3, "bpf_prog_query", "wrong program count on query: %u", prog_cnt)) goto detach; prog_id = link_info_prog_id(link[0], &info); CHECK(prog_ids[0] != prog_id, "bpf_prog_query", "invalid program #0 id on query: %u != %u\n", prog_ids[0], prog_id); CHECK(info.netns.netns_ino == 0, "netns_ino", "unexpected netns_ino: %u\n", info.netns.netns_ino); prog_id = link_info_prog_id(link[1], &info); CHECK(prog_ids[1] != prog_id, "bpf_prog_query", "invalid program #1 id on query: %u != %u\n", prog_ids[1], prog_id); CHECK(info.netns.netns_ino == 0, "netns_ino", "unexpected netns_ino: %u\n", info.netns.netns_ino); prog_id = link_info_prog_id(link[2], &info); CHECK(prog_ids[2] != prog_id, "bpf_prog_query", "invalid program #2 id on query: %u != %u\n", prog_ids[2], prog_id); CHECK(info.netns.netns_ino == 0, "netns_ino", "unexpected netns_ino: %u\n", info.netns.netns_ino); err = bpf_link__detach(link[0]); if (CHECK(err, "link_detach", "failed %d\n", err)) goto detach; /* prog id is still there, but netns_ino is zeroed out */ prog_id = link_info_prog_id(link[0], &info); CHECK(prog_ids[0] != prog_id, "bpf_prog_query", "invalid program #0 id on query: %u != %u\n", prog_ids[0], prog_id); CHECK(info.netns.netns_ino != 0, "netns_ino", "unexpected netns_ino: %u\n", info.netns.netns_ino); detach: if (link[2]) bpf_link__destroy(link[2]); if (link[1]) bpf_link__destroy(link[1]); if (link[0]) bpf_link__destroy(link[0]); close: close(net_fd); } static void run_lookup_prog(const struct test *t) { int server_fds[MAX_SERVERS] = { -1 }; int client_fd, reuse_conn_fd = -1; struct bpf_link *lookup_link; int i, err; lookup_link = attach_lookup_prog(t->lookup_prog); if (!lookup_link) return; for (i = 0; i < ARRAY_SIZE(server_fds); i++) { server_fds[i] = make_server(t->sotype, t->listen_at.ip, t->listen_at.port, t->reuseport_prog); if (server_fds[i] < 0) goto close; err = update_lookup_map(t->sock_map, i, server_fds[i]); if (err) goto close; /* want just one server for non-reuseport test */ if (!t->reuseport_prog) break; } /* Regular UDP socket lookup with reuseport behaves * differently when reuseport group contains connected * sockets. Check that adding a connected UDP socket to the * reuseport group does not affect how reuseport works with * BPF socket lookup. */ if (t->reuseport_has_conns) { struct sockaddr_storage addr = {}; socklen_t len = sizeof(addr); /* Add an extra socket to reuseport group */ reuse_conn_fd = make_server(t->sotype, t->listen_at.ip, t->listen_at.port, t->reuseport_prog); if (reuse_conn_fd < 0) goto close; /* Connect the extra socket to itself */ err = getsockname(reuse_conn_fd, (void *)&addr, &len); if (CHECK(err, "getsockname", "errno %d\n", errno)) goto close; err = connect(reuse_conn_fd, (void *)&addr, len); if (CHECK(err, "connect", "errno %d\n", errno)) goto close; } client_fd = make_client(t->sotype, t->connect_to.ip, t->connect_to.port); if (client_fd < 0) goto close; if (t->sotype == SOCK_STREAM) tcp_echo_test(client_fd, server_fds[t->accept_on]); else udp_echo_test(client_fd, server_fds[t->accept_on]); close(client_fd); close: if (reuse_conn_fd != -1) close(reuse_conn_fd); for (i = 0; i < ARRAY_SIZE(server_fds); i++) { if (server_fds[i] != -1) close(server_fds[i]); } bpf_link__destroy(lookup_link); } static void test_redirect_lookup(struct test_sk_lookup *skel) { const struct test tests[] = { { .desc = "TCP IPv4 redir port", .lookup_prog = skel->progs.redir_port, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { EXT_IP4, INT_PORT }, }, { .desc = "TCP IPv4 redir addr", .lookup_prog = skel->progs.redir_ip4, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4, EXT_PORT }, }, { .desc = "TCP IPv4 redir with reuseport", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4, INT_PORT }, .accept_on = SERVER_B, }, { .desc = "TCP IPv4 redir skip reuseport", .lookup_prog = skel->progs.select_sock_a_no_reuseport, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4, INT_PORT }, .accept_on = SERVER_A, }, { .desc = "TCP IPv6 redir port", .lookup_prog = skel->progs.redir_port, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { EXT_IP6, INT_PORT }, }, { .desc = "TCP IPv6 redir addr", .lookup_prog = skel->progs.redir_ip6, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { INT_IP6, EXT_PORT }, }, { .desc = "TCP IPv4->IPv6 redir port", .lookup_prog = skel->progs.redir_port, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4_V6, INT_PORT }, }, { .desc = "TCP IPv6 redir with reuseport", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { INT_IP6, INT_PORT }, .accept_on = SERVER_B, }, { .desc = "TCP IPv6 redir skip reuseport", .lookup_prog = skel->progs.select_sock_a_no_reuseport, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { INT_IP6, INT_PORT }, .accept_on = SERVER_A, }, { .desc = "UDP IPv4 redir port", .lookup_prog = skel->progs.redir_port, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { EXT_IP4, INT_PORT }, }, { .desc = "UDP IPv4 redir addr", .lookup_prog = skel->progs.redir_ip4, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4, EXT_PORT }, }, { .desc = "UDP IPv4 redir with reuseport", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4, INT_PORT }, .accept_on = SERVER_B, }, { .desc = "UDP IPv4 redir and reuseport with conns", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4, INT_PORT }, .accept_on = SERVER_B, .reuseport_has_conns = true, }, { .desc = "UDP IPv4 redir skip reuseport", .lookup_prog = skel->progs.select_sock_a_no_reuseport, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4, INT_PORT }, .accept_on = SERVER_A, }, { .desc = "UDP IPv6 redir port", .lookup_prog = skel->progs.redir_port, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { EXT_IP6, INT_PORT }, }, { .desc = "UDP IPv6 redir addr", .lookup_prog = skel->progs.redir_ip6, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { INT_IP6, EXT_PORT }, }, { .desc = "UDP IPv4->IPv6 redir port", .lookup_prog = skel->progs.redir_port, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .listen_at = { INT_IP4_V6, INT_PORT }, .connect_to = { EXT_IP4, EXT_PORT }, }, { .desc = "UDP IPv6 redir and reuseport", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { INT_IP6, INT_PORT }, .accept_on = SERVER_B, }, { .desc = "UDP IPv6 redir and reuseport with conns", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { INT_IP6, INT_PORT }, .accept_on = SERVER_B, .reuseport_has_conns = true, }, { .desc = "UDP IPv6 redir skip reuseport", .lookup_prog = skel->progs.select_sock_a_no_reuseport, .reuseport_prog = skel->progs.select_sock_b, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { INT_IP6, INT_PORT }, .accept_on = SERVER_A, }, }; const struct test *t; for (t = tests; t < tests + ARRAY_SIZE(tests); t++) { if (test__start_subtest(t->desc)) run_lookup_prog(t); } } static void drop_on_lookup(const struct test *t) { struct sockaddr_storage dst = {}; int client_fd, server_fd, err; struct bpf_link *lookup_link; ssize_t n; lookup_link = attach_lookup_prog(t->lookup_prog); if (!lookup_link) return; server_fd = make_server(t->sotype, t->listen_at.ip, t->listen_at.port, t->reuseport_prog); if (server_fd < 0) goto detach; client_fd = make_socket(t->sotype, t->connect_to.ip, t->connect_to.port, &dst); if (client_fd < 0) goto close_srv; err = connect(client_fd, (void *)&dst, inetaddr_len(&dst)); if (t->sotype == SOCK_DGRAM) { err = send_byte(client_fd); if (err) goto close_all; /* Read out asynchronous error */ n = recv(client_fd, NULL, 0, 0); err = n == -1; } if (CHECK(!err || errno != ECONNREFUSED, "connect", "unexpected success or error\n")) log_err("expected ECONNREFUSED on connect"); close_all: close(client_fd); close_srv: close(server_fd); detach: bpf_link__destroy(lookup_link); } static void test_drop_on_lookup(struct test_sk_lookup *skel) { const struct test tests[] = { { .desc = "TCP IPv4 drop on lookup", .lookup_prog = skel->progs.lookup_drop, .sotype = SOCK_STREAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { EXT_IP4, EXT_PORT }, }, { .desc = "TCP IPv6 drop on lookup", .lookup_prog = skel->progs.lookup_drop, .sotype = SOCK_STREAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { EXT_IP6, EXT_PORT }, }, { .desc = "UDP IPv4 drop on lookup", .lookup_prog = skel->progs.lookup_drop, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { EXT_IP4, EXT_PORT }, }, { .desc = "UDP IPv6 drop on lookup", .lookup_prog = skel->progs.lookup_drop, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { EXT_IP6, INT_PORT }, }, }; const struct test *t; for (t = tests; t < tests + ARRAY_SIZE(tests); t++) { if (test__start_subtest(t->desc)) drop_on_lookup(t); } } static void drop_on_reuseport(const struct test *t) { struct sockaddr_storage dst = { 0 }; int client, server1, server2, err; struct bpf_link *lookup_link; ssize_t n; lookup_link = attach_lookup_prog(t->lookup_prog); if (!lookup_link) return; server1 = make_server(t->sotype, t->listen_at.ip, t->listen_at.port, t->reuseport_prog); if (server1 < 0) goto detach; err = update_lookup_map(t->sock_map, SERVER_A, server1); if (err) goto detach; /* second server on destination address we should never reach */ server2 = make_server(t->sotype, t->connect_to.ip, t->connect_to.port, NULL /* reuseport prog */); if (server2 < 0) goto close_srv1; client = make_socket(t->sotype, t->connect_to.ip, t->connect_to.port, &dst); if (client < 0) goto close_srv2; err = connect(client, (void *)&dst, inetaddr_len(&dst)); if (t->sotype == SOCK_DGRAM) { err = send_byte(client); if (err) goto close_all; /* Read out asynchronous error */ n = recv(client, NULL, 0, 0); err = n == -1; } if (CHECK(!err || errno != ECONNREFUSED, "connect", "unexpected success or error\n")) log_err("expected ECONNREFUSED on connect"); close_all: close(client); close_srv2: close(server2); close_srv1: close(server1); detach: bpf_link__destroy(lookup_link); } static void test_drop_on_reuseport(struct test_sk_lookup *skel) { const struct test tests[] = { { .desc = "TCP IPv4 drop on reuseport", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.reuseport_drop, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4, INT_PORT }, }, { .desc = "TCP IPv6 drop on reuseport", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.reuseport_drop, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { INT_IP6, INT_PORT }, }, { .desc = "UDP IPv4 drop on reuseport", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.reuseport_drop, .sock_map = skel->maps.redir_map, .sotype = SOCK_DGRAM, .connect_to = { EXT_IP4, EXT_PORT }, .listen_at = { INT_IP4, INT_PORT }, }, { .desc = "TCP IPv6 drop on reuseport", .lookup_prog = skel->progs.select_sock_a, .reuseport_prog = skel->progs.reuseport_drop, .sock_map = skel->maps.redir_map, .sotype = SOCK_STREAM, .connect_to = { EXT_IP6, EXT_PORT }, .listen_at = { INT_IP6, INT_PORT }, }, }; const struct test *t; for (t = tests; t < tests + ARRAY_SIZE(tests); t++) { if (test__start_subtest(t->desc)) drop_on_reuseport(t); } } static void run_sk_assign(struct test_sk_lookup *skel, struct bpf_program *lookup_prog, const char *listen_ip, const char *connect_ip) { int client_fd, peer_fd, server_fds[MAX_SERVERS] = { -1 }; struct bpf_link *lookup_link; int i, err; lookup_link = attach_lookup_prog(lookup_prog); if (!lookup_link) return; for (i = 0; i < ARRAY_SIZE(server_fds); i++) { server_fds[i] = make_server(SOCK_STREAM, listen_ip, 0, NULL); if (server_fds[i] < 0) goto close_servers; err = update_lookup_map(skel->maps.redir_map, i, server_fds[i]); if (err) goto close_servers; } client_fd = make_client(SOCK_STREAM, connect_ip, EXT_PORT); if (client_fd < 0) goto close_servers; peer_fd = accept(server_fds[SERVER_B], NULL, NULL); if (CHECK(peer_fd < 0, "accept", "failed\n")) goto close_client; close(peer_fd); close_client: close(client_fd); close_servers: for (i = 0; i < ARRAY_SIZE(server_fds); i++) { if (server_fds[i] != -1) close(server_fds[i]); } bpf_link__destroy(lookup_link); } static void run_sk_assign_v4(struct test_sk_lookup *skel, struct bpf_program *lookup_prog) { run_sk_assign(skel, lookup_prog, INT_IP4, EXT_IP4); } static void run_sk_assign_v6(struct test_sk_lookup *skel, struct bpf_program *lookup_prog) { run_sk_assign(skel, lookup_prog, INT_IP6, EXT_IP6); } static void run_sk_assign_connected(struct test_sk_lookup *skel, int sotype) { int err, client_fd, connected_fd, server_fd; struct bpf_link *lookup_link; server_fd = make_server(sotype, EXT_IP4, EXT_PORT, NULL); if (server_fd < 0) return; connected_fd = make_client(sotype, EXT_IP4, EXT_PORT); if (connected_fd < 0) goto out_close_server; /* Put a connected socket in redirect map */ err = update_lookup_map(skel->maps.redir_map, SERVER_A, connected_fd); if (err) goto out_close_connected; lookup_link = attach_lookup_prog(skel->progs.sk_assign_esocknosupport); if (!lookup_link) goto out_close_connected; /* Try to redirect TCP SYN / UDP packet to a connected socket */ client_fd = make_client(sotype, EXT_IP4, EXT_PORT); if (client_fd < 0) goto out_unlink_prog; if (sotype == SOCK_DGRAM) { send_byte(client_fd); recv_byte(server_fd); } close(client_fd); out_unlink_prog: bpf_link__destroy(lookup_link); out_close_connected: close(connected_fd); out_close_server: close(server_fd); } static void test_sk_assign_helper(struct test_sk_lookup *skel) { if (test__start_subtest("sk_assign returns EEXIST")) run_sk_assign_v4(skel, skel->progs.sk_assign_eexist); if (test__start_subtest("sk_assign honors F_REPLACE")) run_sk_assign_v4(skel, skel->progs.sk_assign_replace_flag); if (test__start_subtest("sk_assign accepts NULL socket")) run_sk_assign_v4(skel, skel->progs.sk_assign_null); if (test__start_subtest("access ctx->sk")) run_sk_assign_v4(skel, skel->progs.access_ctx_sk); if (test__start_subtest("narrow access to ctx v4")) run_sk_assign_v4(skel, skel->progs.ctx_narrow_access); if (test__start_subtest("narrow access to ctx v6")) run_sk_assign_v6(skel, skel->progs.ctx_narrow_access); if (test__start_subtest("sk_assign rejects TCP established")) run_sk_assign_connected(skel, SOCK_STREAM); if (test__start_subtest("sk_assign rejects UDP connected")) run_sk_assign_connected(skel, SOCK_DGRAM); } struct test_multi_prog { const char *desc; struct bpf_program *prog1; struct bpf_program *prog2; struct bpf_map *redir_map; struct bpf_map *run_map; int expect_errno; struct inet_addr listen_at; }; static void run_multi_prog_lookup(const struct test_multi_prog *t) { struct sockaddr_storage dst = {}; int map_fd, server_fd, client_fd; struct bpf_link *link1, *link2; int prog_idx, done, err; map_fd = bpf_map__fd(t->run_map); done = 0; prog_idx = PROG1; err = bpf_map_update_elem(map_fd, &prog_idx, &done, BPF_ANY); if (CHECK(err, "bpf_map_update_elem", "failed\n")) return; prog_idx = PROG2; err = bpf_map_update_elem(map_fd, &prog_idx, &done, BPF_ANY); if (CHECK(err, "bpf_map_update_elem", "failed\n")) return; link1 = attach_lookup_prog(t->prog1); if (!link1) return; link2 = attach_lookup_prog(t->prog2); if (!link2) goto out_unlink1; server_fd = make_server(SOCK_STREAM, t->listen_at.ip, t->listen_at.port, NULL); if (server_fd < 0) goto out_unlink2; err = update_lookup_map(t->redir_map, SERVER_A, server_fd); if (err) goto out_close_server; client_fd = make_socket(SOCK_STREAM, EXT_IP4, EXT_PORT, &dst); if (client_fd < 0) goto out_close_server; err = connect(client_fd, (void *)&dst, inetaddr_len(&dst)); if (CHECK(err && !t->expect_errno, "connect", "unexpected error %d\n", errno)) goto out_close_client; if (CHECK(err && t->expect_errno && errno != t->expect_errno, "connect", "unexpected error %d\n", errno)) goto out_close_client; done = 0; prog_idx = PROG1; err = bpf_map_lookup_elem(map_fd, &prog_idx, &done); CHECK(err, "bpf_map_lookup_elem", "failed\n"); CHECK(!done, "bpf_map_lookup_elem", "PROG1 !done\n"); done = 0; prog_idx = PROG2; err = bpf_map_lookup_elem(map_fd, &prog_idx, &done); CHECK(err, "bpf_map_lookup_elem", "failed\n"); CHECK(!done, "bpf_map_lookup_elem", "PROG2 !done\n"); out_close_client: close(client_fd); out_close_server: close(server_fd); out_unlink2: bpf_link__destroy(link2); out_unlink1: bpf_link__destroy(link1); } static void test_multi_prog_lookup(struct test_sk_lookup *skel) { struct test_multi_prog tests[] = { { .desc = "multi prog - pass, pass", .prog1 = skel->progs.multi_prog_pass1, .prog2 = skel->progs.multi_prog_pass2, .listen_at = { EXT_IP4, EXT_PORT }, }, { .desc = "multi prog - drop, drop", .prog1 = skel->progs.multi_prog_drop1, .prog2 = skel->progs.multi_prog_drop2, .listen_at = { EXT_IP4, EXT_PORT }, .expect_errno = ECONNREFUSED, }, { .desc = "multi prog - pass, drop", .prog1 = skel->progs.multi_prog_pass1, .prog2 = skel->progs.multi_prog_drop2, .listen_at = { EXT_IP4, EXT_PORT }, .expect_errno = ECONNREFUSED, }, { .desc = "multi prog - drop, pass", .prog1 = skel->progs.multi_prog_drop1, .prog2 = skel->progs.multi_prog_pass2, .listen_at = { EXT_IP4, EXT_PORT }, .expect_errno = ECONNREFUSED, }, { .desc = "multi prog - pass, redir", .prog1 = skel->progs.multi_prog_pass1, .prog2 = skel->progs.multi_prog_redir2, .listen_at = { INT_IP4, INT_PORT }, }, { .desc = "multi prog - redir, pass", .prog1 = skel->progs.multi_prog_redir1, .prog2 = skel->progs.multi_prog_pass2, .listen_at = { INT_IP4, INT_PORT }, }, { .desc = "multi prog - drop, redir", .prog1 = skel->progs.multi_prog_drop1, .prog2 = skel->progs.multi_prog_redir2, .listen_at = { INT_IP4, INT_PORT }, }, { .desc = "multi prog - redir, drop", .prog1 = skel->progs.multi_prog_redir1, .prog2 = skel->progs.multi_prog_drop2, .listen_at = { INT_IP4, INT_PORT }, }, { .desc = "multi prog - redir, redir", .prog1 = skel->progs.multi_prog_redir1, .prog2 = skel->progs.multi_prog_redir2, .listen_at = { INT_IP4, INT_PORT }, }, }; struct test_multi_prog *t; for (t = tests; t < tests + ARRAY_SIZE(tests); t++) { t->redir_map = skel->maps.redir_map; t->run_map = skel->maps.run_map; if (test__start_subtest(t->desc)) run_multi_prog_lookup(t); } } static void run_tests(struct test_sk_lookup *skel) { if (test__start_subtest("query lookup prog")) query_lookup_prog(skel); test_redirect_lookup(skel); test_drop_on_lookup(skel); test_drop_on_reuseport(skel); test_sk_assign_helper(skel); test_multi_prog_lookup(skel); } static int switch_netns(void) { static const char * const setup_script[] = { "ip -6 addr add dev lo " EXT_IP6 "/128", "ip -6 addr add dev lo " INT_IP6 "/128", "ip link set dev lo up", NULL, }; const char * const *cmd; int err; err = unshare(CLONE_NEWNET); if (CHECK(err, "unshare", "failed\n")) { log_err("unshare(CLONE_NEWNET)"); return -1; } for (cmd = setup_script; *cmd; cmd++) { err = system(*cmd); if (CHECK(err, "system", "failed\n")) { log_err("system(%s)", *cmd); return -1; } } return 0; } void test_sk_lookup(void) { struct test_sk_lookup *skel; int err; err = switch_netns(); if (err) return; skel = test_sk_lookup__open_and_load(); if (CHECK(!skel, "skel open_and_load", "failed\n")) return; run_tests(skel); test_sk_lookup__destroy(skel); }