From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CF52C47255 for ; Mon, 11 May 2020 18:52:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 00199206DB for ; Mon, 11 May 2020 18:52:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="sYU4PWUj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731287AbgEKSww (ORCPT ); Mon, 11 May 2020 14:52:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1731284AbgEKSwt (ORCPT ); Mon, 11 May 2020 14:52:49 -0400 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95072C061A0C for ; Mon, 11 May 2020 11:52:48 -0700 (PDT) Received: by mail-wm1-x341.google.com with SMTP id e26so19159380wmk.5 for ; Mon, 11 May 2020 11:52:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ze/h/CNZ/91B28Ipr0bBfUZchvfb9nsJ7KusesHA9+8=; b=sYU4PWUj/xVA9pUSitEbqXibw2TD+mMqSKc1kfkitZAnyYlZ9GChb7zJ1okvNzTrNZ RUT6AK20LeyGZBqQNy4qUBbvGncNp7dCXLySELi1zY7U5TYfrr+Z0XiZqwWJKGX0NbNv IPb/OqOGnvV3IXFzyz8bArdbTZaFdDFG7s3eM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=ze/h/CNZ/91B28Ipr0bBfUZchvfb9nsJ7KusesHA9+8=; b=sXvie05F0cWVGCOrFihLSb/YzJ8KrsxbhASVkjd/Qws0apkRSO6URmV2BEfaz1S+wn 91mE3O3doJuvtQXFFP6yIMyIFjbkprEuPGBhOaqky5Km+glvaJJnQ2SbCYKBNySJJSQf UucmSTK59O3pH+GvsQqdIt5R20iUJHvy9mWHx9eokQ1/wYXx0aubsAgQklJwXcwIiaUQ JjhSk4583JL9cmXB7GGpawtluBxDIxQ0LchVesPGbSOCHhMnFtG0g70gQW5rHMfMaPid ernNu8qp7nPTGhLlcDO/ffBOBHfia0D0XgTFFl7NddQ0XWo7ewYc4pVtKiMnDlRCxLev GAMQ== X-Gm-Message-State: AGi0PuYBgXC3BJvi52Hn2NJaZAMDwpUGBYf7bTHX+v2m4wpOT0qOk0G9 UKDPLPYSldswYKHKdJbQ+wOkVA== X-Google-Smtp-Source: APiQypI9RoFMZOoV3cnZFuQqxWCCY8o/0MmyVLJgIyn+Wz5pmYK2zSUXVKmpjsFVNq51VcWjQuoSeg== X-Received: by 2002:a1c:7415:: with SMTP id p21mr32405160wmc.93.1589223166721; Mon, 11 May 2020 11:52:46 -0700 (PDT) Received: from cloudflare.com ([2a02:a310:c262:aa00:b35e:8938:2c2a:ba8b]) by smtp.gmail.com with ESMTPSA id n6sm16988638wrt.58.2020.05.11.11.52.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 May 2020 11:52:46 -0700 (PDT) From: Jakub Sitnicki To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: dccp@vger.kernel.org, kernel-team@cloudflare.com, Alexei Starovoitov , Daniel Borkmann , "David S. Miller" , Eric Dumazet , Gerrit Renker , Jakub Kicinski , Andrii Nakryiko , Martin KaFai Lau Subject: [PATCH bpf-next v2 17/17] selftests/bpf: Tests for BPF_SK_LOOKUP attach point Date: Mon, 11 May 2020 20:52:18 +0200 Message-Id: <20200511185218.1422406-18-jakub@cloudflare.com> X-Mailer: git-send-email 2.25.3 In-Reply-To: <20200511185218.1422406-1-jakub@cloudflare.com> References: <20200511185218.1422406-1-jakub@cloudflare.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Add tests to test_progs that exercise: - attaching/detaching/querying sk_lookup program, - overriding socket lookup result for TCP/UDP with BPF sk_lookup by a) selecting a socket fetched from a SOCKMAP, or b) failing the lookup with no match. Tests cover two special cases: - selecting an IPv6 socket (non v6-only) to receive an IPv4 packet, - using BPF sk_lookup together with BPF sk_reuseport program. Signed-off-by: Jakub Sitnicki --- Notes: v2: - Adjust for fields renames in struct bpf_sk_lookup. .../selftests/bpf/prog_tests/sk_lookup.c | 999 ++++++++++++++++++ .../selftests/bpf/progs/test_sk_lookup_kern.c | 162 +++ 2 files changed, 1161 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/sk_lookup.c create mode 100644 tools/testing/selftests/bpf/progs/test_sk_lookup_kern.c diff --git a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c new file mode 100644 index 000000000000..96765b156f6f --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c @@ -0,0 +1,999 @@ +// 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: + * + * 1. attaching/detaching/querying BPF sk_lookup program, + * 2. overriding socket lookup result by: + * a) selecting a listening (TCP) or receiving (UDP) socket, + * b) failing the lookup with no match. + * + * Special cases covered are: + * - selecting an IPv6 socket (non v6-only) to receive an IPv4 packet, + * - using BPF sk_lookup together with BPF sk_reuseport program. + * + * Tests run in a dedicated network namespace. + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "bpf_rlimit.h" +#include "bpf_util.h" +#include "cgroup_helpers.h" +#include "test_sk_lookup_kern.skel.h" +#include "test_progs.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_A = 0, + SERVER_B = 1, + MAX_SERVERS, +}; + +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 send_to; + struct inet_addr recv_at; +}; + +static bool is_ipv6(const char *ip) +{ + return !!strchr(ip, ':'); +} + +static int make_addr(const char *ip, int port, struct sockaddr_storage *addr) +{ + struct sockaddr_in6 *addr6 = (void *)addr; + struct sockaddr_in *addr4 = (void *)addr; + int ret; + + errno = 0; + if (is_ipv6(ip)) { + ret = inet_pton(AF_INET6, ip, &addr6->sin6_addr); + if (CHECK_FAIL(ret <= 0)) { + log_err("failed to convert IPv6 address '%s'", ip); + return -1; + } + addr6->sin6_family = AF_INET6; + addr6->sin6_port = htons(port); + } else { + ret = inet_pton(AF_INET, ip, &addr4->sin_addr); + if (CHECK_FAIL(ret <= 0)) { + log_err("failed to convert IPv4 address '%s'", ip); + return -1; + } + addr4->sin_family = AF_INET; + addr4->sin_port = htons(port); + } + return 0; +} + +static int setup_reuseport_prog(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; + log_err("failed to get fd for program '%s'", + bpf_program__name(reuseport_prog)); + return -1; + } + + err = setsockopt(sock_fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, + &prog_fd, sizeof(prog_fd)); + if (CHECK_FAIL(err)) { + log_err("failed to ATTACH_REUSEPORT_EBPF"); + 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_with_addr(int sotype, const char *ip, int port, + struct sockaddr_storage *addr) +{ + struct timeval timeo = { .tv_sec = IO_TIMEOUT_SEC }; + int err, fd; + + err = make_addr(ip, port, addr); + if (err) + return -1; + + fd = socket(addr->ss_family, sotype, 0); + if (CHECK_FAIL(fd < 0)) { + log_err("failed to create listen socket"); + return -1; + } + + err = setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo)); + if (CHECK_FAIL(err)) { + log_err("failed to set SO_SNDTIMEO"); + return -1; + } + + err = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo)); + if (CHECK_FAIL(err)) { + log_err("failed to set SO_RCVTIMEO"); + 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_with_addr(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_FAIL(err)) { + 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_FAIL(err)) { + 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_FAIL(err)) { + log_err("failed to enable SO_REUSEADDR"); + goto fail; + } + } + + if (reuseport_prog) { + err = setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, + sizeof(one)); + if (CHECK_FAIL(err)) { + log_err("failed to enable SO_REUSEPORT"); + goto fail; + } + } + + err = bind(fd, (void *)&addr, inetaddr_len(&addr)); + if (CHECK_FAIL(err)) { + log_err("failed to bind listen socket"); + goto fail; + } + + if (sotype == SOCK_STREAM) { + err = listen(fd, SOMAXCONN); + if (CHECK_FAIL(err)) { + 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 = setup_reuseport_prog(fd, reuseport_prog); + if (err) + 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_with_addr(sotype, ip, port, &addr); + if (fd < 0) + return -1; + + err = connect(fd, (void *)&addr, inetaddr_len(&addr)); + if (CHECK_FAIL(err)) { + 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_FAIL(n <= 0)) { + 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_FAIL(n <= 0)) { + 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_FAIL(fd < 0)) { + log_err("failed to accept"); + return -1; + } + + n = recv(fd, buf, sizeof(buf), 0); + if (CHECK_FAIL(n <= 0)) { + log_err("failed/partial recv"); + ret = -1; + goto close; + } + + n = send(fd, buf, n, 0); + if (CHECK_FAIL(n <= 0)) { + 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_FAIL(n <= 0)) { + log_err("failed to receive"); + return -1; + } + if (CHECK_FAIL(msg.msg_flags & MSG_CTRUNC)) { + log_err("truncated cmsg"); + 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_FAIL(!dst_addr)) { + log_err("failed to get destination address"); + 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_FAIL(fd < 0)) { + log_err("failed to create tx socket"); + return -1; + } + + ret = bind(fd, (struct sockaddr *)dst_addr, sizeof(*dst_addr)); + if (CHECK_FAIL(ret)) { + log_err("failed to bind tx socket"); + goto out; + } + + msg.msg_control = NULL; + msg.msg_controllen = 0; + n = sendmsg(fd, &msg, 0); + if (CHECK_FAIL(n <= 0)) { + 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 int attach_lookup_prog(struct bpf_program *prog) +{ + const char *prog_name = bpf_program__name(prog); + enum bpf_attach_type attach_type; + int err, prog_fd; + + prog_fd = bpf_program__fd(prog); + if (CHECK_FAIL(prog_fd < 0)) { + errno = -prog_fd; + log_err("failed to get fd for program '%s'", prog_name); + return -1; + } + + attach_type = bpf_program__get_expected_attach_type(prog); + err = bpf_prog_attach(prog_fd, -1 /* target fd */, attach_type, 0); + if (CHECK_FAIL(err)) { + log_err("failed to attach program '%s'", prog_name); + return -1; + } + + return 0; +} + +static int detach_lookup_prog(struct bpf_program *prog) +{ + const char *prog_name = bpf_program__name(prog); + enum bpf_attach_type attach_type; + int err, prog_fd; + + prog_fd = bpf_program__fd(prog); + if (CHECK_FAIL(prog_fd < 0)) { + errno = -prog_fd; + log_err("failed to get fd for program '%s'", prog_name); + return -1; + } + + attach_type = bpf_program__get_expected_attach_type(prog); + err = bpf_prog_detach2(prog_fd, -1 /* attachable fd */, attach_type); + if (CHECK_FAIL(err)) { + log_err("failed to detach program '%s'", prog_name); + return -1; + } + + return 0; +} + +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_FAIL(map_fd < 0)) { + 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_FAIL(err)) { + log_err("failed to update redir_map @ %d", index); + return -1; + } + + return 0; +} + +static void query_lookup_prog(struct test_sk_lookup_kern *skel) +{ + struct bpf_program *lookup_prog = skel->progs.lookup_pass; + enum bpf_attach_type attach_type; + __u32 attach_flags = 0; + __u32 prog_ids[1] = { 0 }; + __u32 prog_cnt = 1; + int net_fd = -1; + int err; + + net_fd = open("/proc/self/ns/net", O_RDONLY); + if (CHECK_FAIL(net_fd < 0)) { + log_err("failed to open /proc/self/ns/net"); + return; + } + + err = attach_lookup_prog(lookup_prog); + if (err) + goto close; + + attach_type = bpf_program__get_expected_attach_type(lookup_prog); + err = bpf_prog_query(net_fd, attach_type, 0 /* query flags */, + &attach_flags, prog_ids, &prog_cnt); + if (CHECK_FAIL(err)) { + log_err("failed to query lookup prog"); + goto detach; + } + + errno = 0; + if (CHECK_FAIL(attach_flags != 0)) { + log_err("wrong attach_flags on query: %u", attach_flags); + goto detach; + } + if (CHECK_FAIL(prog_cnt != 1)) { + log_err("wrong program count on query: %u", prog_cnt); + goto detach; + } + if (CHECK_FAIL(prog_ids[0] == 0)) { + log_err("invalid program id on query: %u", prog_ids[0]); + goto detach; + } + +detach: + detach_lookup_prog(lookup_prog); +close: + close(net_fd); +} + +static void run_lookup_prog(const struct test *t) +{ + int client_fd, server_fds[MAX_SERVERS] = { -1 }; + int i, err, server_idx; + + err = attach_lookup_prog(t->lookup_prog); + if (err) + return; + + for (i = 0; i < ARRAY_SIZE(server_fds); i++) { + server_fds[i] = make_server(t->sotype, t->recv_at.ip, + t->recv_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 detach; + + /* want just one server for non-reuseport test */ + if (!t->reuseport_prog) + break; + } + + client_fd = make_client(t->sotype, t->send_to.ip, t->send_to.port); + if (client_fd < 0) + goto close; + + /* reuseport prog always selects server B */ + server_idx = t->reuseport_prog ? SERVER_B : SERVER_A; + + if (t->sotype == SOCK_STREAM) + tcp_echo_test(client_fd, server_fds[server_idx]); + else + udp_echo_test(client_fd, server_fds[server_idx]); + + close(client_fd); +close: + for (i = 0; i < ARRAY_SIZE(server_fds); i++) + close(server_fds[i]); +detach: + detach_lookup_prog(t->lookup_prog); +} + +static void test_override_lookup(struct test_sk_lookup_kern *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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { INT_IP4, EXT_PORT }, + }, + { + .desc = "TCP IPv4 redir and reuseport", + .lookup_prog = skel->progs.select_sock_a, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { INT_IP4, INT_PORT }, + .reuseport_prog = skel->progs.select_sock_b, + }, + { + .desc = "TCP IPv6 redir port", + .lookup_prog = skel->progs.redir_port, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .recv_at = { INT_IP4_V6, INT_PORT }, + .send_to = { EXT_IP4, EXT_PORT }, + }, + { + .desc = "TCP IPv6 redir and reuseport", + .lookup_prog = skel->progs.select_sock_a, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_at = { INT_IP6, INT_PORT }, + .reuseport_prog = skel->progs.select_sock_b, + }, + { + .desc = "UDP IPv4 redir port", + .lookup_prog = skel->progs.redir_port, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { INT_IP4, EXT_PORT }, + }, + { + .desc = "UDP IPv4 redir and reuseport", + .lookup_prog = skel->progs.select_sock_a, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { INT_IP4, INT_PORT }, + .reuseport_prog = skel->progs.select_sock_b, + }, + { + .desc = "UDP IPv6 redir port", + .lookup_prog = skel->progs.redir_port, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .recv_at = { INT_IP4_V6, INT_PORT }, + .send_to = { EXT_IP4, EXT_PORT }, + }, + { + .desc = "UDP IPv6 redir and reuseport", + .lookup_prog = skel->progs.select_sock_a, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_at = { INT_IP6, INT_PORT }, + .reuseport_prog = skel->progs.select_sock_b, + }, + }; + 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 = { 0 }; + int client_fd, server_fd, err; + ssize_t n; + + if (attach_lookup_prog(t->lookup_prog)) + return; + + server_fd = make_server(t->sotype, t->recv_at.ip, t->recv_at.port, + t->reuseport_prog); + if (server_fd < 0) + goto detach; + + client_fd = make_socket_with_addr(t->sotype, t->send_to.ip, + t->send_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_FAIL(!err || errno != ECONNREFUSED)) + log_err("expected ECONNREFUSED on connect"); + +close_all: + close(client_fd); +close_srv: + close(server_fd); +detach: + detach_lookup_prog(t->lookup_prog); +} + +static void test_drop_on_lookup(struct test_sk_lookup_kern *skel) +{ + const struct test tests[] = { + { + .desc = "TCP IPv4 drop on lookup", + .lookup_prog = skel->progs.lookup_drop, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { EXT_IP4, EXT_PORT }, + }, + { + .desc = "TCP IPv6 drop on lookup", + .lookup_prog = skel->progs.lookup_drop, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_at = { EXT_IP6, EXT_PORT }, + }, + { + .desc = "UDP IPv4 drop on lookup", + .lookup_prog = skel->progs.lookup_drop, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { EXT_IP4, EXT_PORT }, + }, + { + .desc = "UDP IPv6 drop on lookup", + .lookup_prog = skel->progs.lookup_drop, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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; + ssize_t n; + + if (attach_lookup_prog(t->lookup_prog)) + return; + + server1 = make_server(t->sotype, t->recv_at.ip, t->recv_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->send_to.ip, t->send_to.port, + NULL /* reuseport prog */); + if (server2 < 0) + goto close_srv1; + + client = make_socket_with_addr(t->sotype, t->send_to.ip, + t->send_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_FAIL(!err || errno != ECONNREFUSED)) + log_err("expected ECONNREFUSED on connect"); + +close_all: + close(client); +close_srv2: + close(server2); +close_srv1: + close(server1); +detach: + detach_lookup_prog(t->lookup_prog); +} + +static void test_drop_on_reuseport(struct test_sk_lookup_kern *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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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_tests(struct test_sk_lookup_kern *skel) +{ + if (test__start_subtest("query lookup prog")) + query_lookup_prog(skel); + test_override_lookup(skel); + test_drop_on_lookup(skel); + test_drop_on_reuseport(skel); +} + +static int switch_netns(int *saved_net) +{ + static const char * const setup_script[] = { + "ip -6 addr add dev lo " EXT_IP6 "/128 nodad", + "ip -6 addr add dev lo " INT_IP6 "/128 nodad", + "ip link set dev lo up", + NULL, + }; + const char * const *cmd; + int net_fd, err; + + net_fd = open("/proc/self/ns/net", O_RDONLY); + if (CHECK_FAIL(net_fd < 0)) { + log_err("open(/proc/self/ns/net)"); + return -1; + } + + err = unshare(CLONE_NEWNET); + if (CHECK_FAIL(err)) { + log_err("unshare(CLONE_NEWNET)"); + goto close; + } + + for (cmd = setup_script; *cmd; cmd++) { + err = system(*cmd); + if (CHECK_FAIL(err)) { + log_err("system(%s)", *cmd); + goto close; + } + } + + *saved_net = net_fd; + return 0; + +close: + close(net_fd); + return -1; +} + +static void restore_netns(int saved_net) +{ + int err; + + err = setns(saved_net, CLONE_NEWNET); + if (CHECK_FAIL(err)) + log_err("setns(CLONE_NEWNET)"); + + close(saved_net); +} + +void test_sk_lookup(void) +{ + struct test_sk_lookup_kern *skel; + int err, saved_net; + + err = switch_netns(&saved_net); + if (err) + return; + + skel = test_sk_lookup_kern__open_and_load(); + if (CHECK_FAIL(!skel)) { + errno = 0; + log_err("failed to open and load BPF skeleton"); + goto restore_netns; + } + + run_tests(skel); + + test_sk_lookup_kern__destroy(skel); +restore_netns: + restore_netns(saved_net); +} diff --git a/tools/testing/selftests/bpf/progs/test_sk_lookup_kern.c b/tools/testing/selftests/bpf/progs/test_sk_lookup_kern.c new file mode 100644 index 000000000000..fc3ad9a69484 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_sk_lookup_kern.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause +// Copyright (c) 2020 Cloudflare + +#include +#include + +#include +#include + +#define IP4(a, b, c, d) \ + bpf_htonl((((__u32)(a) & 0xffU) << 24) | \ + (((__u32)(b) & 0xffU) << 16) | \ + (((__u32)(c) & 0xffU) << 8) | \ + (((__u32)(d) & 0xffU) << 0)) +#define IP6(aaaa, bbbb, cccc, dddd) \ + { bpf_htonl(aaaa), bpf_htonl(bbbb), bpf_htonl(cccc), bpf_htonl(dddd) } + +#define MAX_SOCKS 32 + +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(max_entries, MAX_SOCKS); + __type(key, __u32); + __type(value, __u64); +} redir_map SEC(".maps"); + +enum { + SERVER_A = 0, + SERVER_B = 1, +}; + +enum { + NO_FLAGS = 0, +}; + +static const __u32 DST_PORT = 7007; +static const __u32 DST_IP4 = IP4(127, 0, 0, 1); +static const __u32 DST_IP6[] = IP6(0xfd000000, 0x0, 0x0, 0x00000001); + +SEC("sk_lookup/lookup_pass") +int lookup_pass(struct bpf_sk_lookup *ctx) +{ + return BPF_OK; +} + +SEC("sk_lookup/lookup_drop") +int lookup_drop(struct bpf_sk_lookup *ctx) +{ + return BPF_DROP; +} + +SEC("sk_reuseport/reuse_pass") +int reuseport_pass(struct sk_reuseport_md *ctx) +{ + return SK_PASS; +} + +SEC("sk_reuseport/reuse_drop") +int reuseport_drop(struct sk_reuseport_md *ctx) +{ + return SK_DROP; +} + +/* Redirect packets destined for port DST_PORT to socket at redir_map[0]. */ +SEC("sk_lookup/redir_port") +int redir_port(struct bpf_sk_lookup *ctx) +{ + __u32 key = SERVER_A; + struct bpf_sock *sk; + int err; + + if (ctx->local_port != DST_PORT) + return BPF_OK; + + sk = bpf_map_lookup_elem(&redir_map, &key); + if (!sk) + return BPF_OK; + + err = bpf_sk_assign(ctx, sk, NO_FLAGS); + bpf_sk_release(sk); + return err ? BPF_DROP : BPF_REDIRECT; +} + +/* Redirect packets destined for DST_IP4 address to socket at redir_map[0]. */ +SEC("sk_lookup/redir_ip4") +int redir_ip4(struct bpf_sk_lookup *ctx) +{ + __u32 key = SERVER_A; + struct bpf_sock *sk; + int err; + + if (ctx->family != AF_INET) + return BPF_OK; + if (ctx->local_port != DST_PORT) + return BPF_OK; + if (ctx->local_ip4 != DST_IP4) + return BPF_OK; + + sk = bpf_map_lookup_elem(&redir_map, &key); + if (!sk) + return BPF_OK; + + err = bpf_sk_assign(ctx, sk, NO_FLAGS); + bpf_sk_release(sk); + return err ? BPF_DROP : BPF_REDIRECT; +} + +/* Redirect packets destined for DST_IP6 address to socket at redir_map[0]. */ +SEC("sk_lookup/redir_ip6") +int redir_ip6(struct bpf_sk_lookup *ctx) +{ + __u32 key = SERVER_A; + struct bpf_sock *sk; + int err; + + if (ctx->family != AF_INET6) + return BPF_OK; + if (ctx->local_port != DST_PORT) + return BPF_OK; + if (ctx->local_ip6[0] != DST_IP6[0] || + ctx->local_ip6[1] != DST_IP6[1] || + ctx->local_ip6[2] != DST_IP6[2] || + ctx->local_ip6[3] != DST_IP6[3]) + return BPF_OK; + + sk = bpf_map_lookup_elem(&redir_map, &key); + if (!sk) + return BPF_OK; + + err = bpf_sk_assign(ctx, sk, NO_FLAGS); + bpf_sk_release(sk); + return err ? BPF_DROP : BPF_REDIRECT; +} + +SEC("sk_lookup/select_sock_a") +int select_sock_a(struct bpf_sk_lookup *ctx) +{ + __u32 key = SERVER_A; + struct bpf_sock *sk; + int err; + + sk = bpf_map_lookup_elem(&redir_map, &key); + if (!sk) + return BPF_OK; + + err = bpf_sk_assign(ctx, sk, NO_FLAGS); + bpf_sk_release(sk); + return err ? BPF_DROP : BPF_REDIRECT; +} + +SEC("sk_reuseport/select_sock_b") +int select_sock_b(struct sk_reuseport_md *ctx) +{ + __u32 key = SERVER_B; + int err; + + err = bpf_sk_select_reuseport(ctx, &redir_map, &key, NO_FLAGS); + return err ? SK_DROP : SK_PASS; +} + +char _license[] SEC("license") = "Dual BSD/GPL"; +__u32 _version SEC("version") = 1; -- 2.25.3 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Sitnicki Date: Mon, 11 May 2020 18:52:18 +0000 Subject: [PATCH bpf-next v2 17/17] selftests/bpf: Tests for BPF_SK_LOOKUP attach point Message-Id: <20200511185218.1422406-18-jakub@cloudflare.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: dccp@vger.kernel.org Add tests to test_progs that exercise: - attaching/detaching/querying sk_lookup program, - overriding socket lookup result for TCP/UDP with BPF sk_lookup by a) selecting a socket fetched from a SOCKMAP, or b) failing the lookup with no match. Tests cover two special cases: - selecting an IPv6 socket (non v6-only) to receive an IPv4 packet, - using BPF sk_lookup together with BPF sk_reuseport program. Signed-off-by: Jakub Sitnicki --- Notes: v2: - Adjust for fields renames in struct bpf_sk_lookup. .../selftests/bpf/prog_tests/sk_lookup.c | 999 ++++++++++++++++++ .../selftests/bpf/progs/test_sk_lookup_kern.c | 162 +++ 2 files changed, 1161 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/sk_lookup.c create mode 100644 tools/testing/selftests/bpf/progs/test_sk_lookup_kern.c diff --git a/tools/testing/selftests/bpf/prog_tests/sk_lookup.c b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c new file mode 100644 index 000000000000..96765b156f6f --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/sk_lookup.c @@ -0,0 +1,999 @@ +// 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: + * + * 1. attaching/detaching/querying BPF sk_lookup program, + * 2. overriding socket lookup result by: + * a) selecting a listening (TCP) or receiving (UDP) socket, + * b) failing the lookup with no match. + * + * Special cases covered are: + * - selecting an IPv6 socket (non v6-only) to receive an IPv4 packet, + * - using BPF sk_lookup together with BPF sk_reuseport program. + * + * Tests run in a dedicated network namespace. + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "bpf_rlimit.h" +#include "bpf_util.h" +#include "cgroup_helpers.h" +#include "test_sk_lookup_kern.skel.h" +#include "test_progs.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_A = 0, + SERVER_B = 1, + MAX_SERVERS, +}; + +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 send_to; + struct inet_addr recv_at; +}; + +static bool is_ipv6(const char *ip) +{ + return !!strchr(ip, ':'); +} + +static int make_addr(const char *ip, int port, struct sockaddr_storage *addr) +{ + struct sockaddr_in6 *addr6 = (void *)addr; + struct sockaddr_in *addr4 = (void *)addr; + int ret; + + errno = 0; + if (is_ipv6(ip)) { + ret = inet_pton(AF_INET6, ip, &addr6->sin6_addr); + if (CHECK_FAIL(ret <= 0)) { + log_err("failed to convert IPv6 address '%s'", ip); + return -1; + } + addr6->sin6_family = AF_INET6; + addr6->sin6_port = htons(port); + } else { + ret = inet_pton(AF_INET, ip, &addr4->sin_addr); + if (CHECK_FAIL(ret <= 0)) { + log_err("failed to convert IPv4 address '%s'", ip); + return -1; + } + addr4->sin_family = AF_INET; + addr4->sin_port = htons(port); + } + return 0; +} + +static int setup_reuseport_prog(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; + log_err("failed to get fd for program '%s'", + bpf_program__name(reuseport_prog)); + return -1; + } + + err = setsockopt(sock_fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, + &prog_fd, sizeof(prog_fd)); + if (CHECK_FAIL(err)) { + log_err("failed to ATTACH_REUSEPORT_EBPF"); + 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_with_addr(int sotype, const char *ip, int port, + struct sockaddr_storage *addr) +{ + struct timeval timeo = { .tv_sec = IO_TIMEOUT_SEC }; + int err, fd; + + err = make_addr(ip, port, addr); + if (err) + return -1; + + fd = socket(addr->ss_family, sotype, 0); + if (CHECK_FAIL(fd < 0)) { + log_err("failed to create listen socket"); + return -1; + } + + err = setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo)); + if (CHECK_FAIL(err)) { + log_err("failed to set SO_SNDTIMEO"); + return -1; + } + + err = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo)); + if (CHECK_FAIL(err)) { + log_err("failed to set SO_RCVTIMEO"); + 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_with_addr(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_FAIL(err)) { + 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_FAIL(err)) { + 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_FAIL(err)) { + log_err("failed to enable SO_REUSEADDR"); + goto fail; + } + } + + if (reuseport_prog) { + err = setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one, + sizeof(one)); + if (CHECK_FAIL(err)) { + log_err("failed to enable SO_REUSEPORT"); + goto fail; + } + } + + err = bind(fd, (void *)&addr, inetaddr_len(&addr)); + if (CHECK_FAIL(err)) { + log_err("failed to bind listen socket"); + goto fail; + } + + if (sotype = SOCK_STREAM) { + err = listen(fd, SOMAXCONN); + if (CHECK_FAIL(err)) { + 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 = setup_reuseport_prog(fd, reuseport_prog); + if (err) + 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_with_addr(sotype, ip, port, &addr); + if (fd < 0) + return -1; + + err = connect(fd, (void *)&addr, inetaddr_len(&addr)); + if (CHECK_FAIL(err)) { + 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_FAIL(n <= 0)) { + 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_FAIL(n <= 0)) { + 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_FAIL(fd < 0)) { + log_err("failed to accept"); + return -1; + } + + n = recv(fd, buf, sizeof(buf), 0); + if (CHECK_FAIL(n <= 0)) { + log_err("failed/partial recv"); + ret = -1; + goto close; + } + + n = send(fd, buf, n, 0); + if (CHECK_FAIL(n <= 0)) { + 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_FAIL(n <= 0)) { + log_err("failed to receive"); + return -1; + } + if (CHECK_FAIL(msg.msg_flags & MSG_CTRUNC)) { + log_err("truncated cmsg"); + 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_FAIL(!dst_addr)) { + log_err("failed to get destination address"); + 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_FAIL(fd < 0)) { + log_err("failed to create tx socket"); + return -1; + } + + ret = bind(fd, (struct sockaddr *)dst_addr, sizeof(*dst_addr)); + if (CHECK_FAIL(ret)) { + log_err("failed to bind tx socket"); + goto out; + } + + msg.msg_control = NULL; + msg.msg_controllen = 0; + n = sendmsg(fd, &msg, 0); + if (CHECK_FAIL(n <= 0)) { + 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 int attach_lookup_prog(struct bpf_program *prog) +{ + const char *prog_name = bpf_program__name(prog); + enum bpf_attach_type attach_type; + int err, prog_fd; + + prog_fd = bpf_program__fd(prog); + if (CHECK_FAIL(prog_fd < 0)) { + errno = -prog_fd; + log_err("failed to get fd for program '%s'", prog_name); + return -1; + } + + attach_type = bpf_program__get_expected_attach_type(prog); + err = bpf_prog_attach(prog_fd, -1 /* target fd */, attach_type, 0); + if (CHECK_FAIL(err)) { + log_err("failed to attach program '%s'", prog_name); + return -1; + } + + return 0; +} + +static int detach_lookup_prog(struct bpf_program *prog) +{ + const char *prog_name = bpf_program__name(prog); + enum bpf_attach_type attach_type; + int err, prog_fd; + + prog_fd = bpf_program__fd(prog); + if (CHECK_FAIL(prog_fd < 0)) { + errno = -prog_fd; + log_err("failed to get fd for program '%s'", prog_name); + return -1; + } + + attach_type = bpf_program__get_expected_attach_type(prog); + err = bpf_prog_detach2(prog_fd, -1 /* attachable fd */, attach_type); + if (CHECK_FAIL(err)) { + log_err("failed to detach program '%s'", prog_name); + return -1; + } + + return 0; +} + +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_FAIL(map_fd < 0)) { + 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_FAIL(err)) { + log_err("failed to update redir_map @ %d", index); + return -1; + } + + return 0; +} + +static void query_lookup_prog(struct test_sk_lookup_kern *skel) +{ + struct bpf_program *lookup_prog = skel->progs.lookup_pass; + enum bpf_attach_type attach_type; + __u32 attach_flags = 0; + __u32 prog_ids[1] = { 0 }; + __u32 prog_cnt = 1; + int net_fd = -1; + int err; + + net_fd = open("/proc/self/ns/net", O_RDONLY); + if (CHECK_FAIL(net_fd < 0)) { + log_err("failed to open /proc/self/ns/net"); + return; + } + + err = attach_lookup_prog(lookup_prog); + if (err) + goto close; + + attach_type = bpf_program__get_expected_attach_type(lookup_prog); + err = bpf_prog_query(net_fd, attach_type, 0 /* query flags */, + &attach_flags, prog_ids, &prog_cnt); + if (CHECK_FAIL(err)) { + log_err("failed to query lookup prog"); + goto detach; + } + + errno = 0; + if (CHECK_FAIL(attach_flags != 0)) { + log_err("wrong attach_flags on query: %u", attach_flags); + goto detach; + } + if (CHECK_FAIL(prog_cnt != 1)) { + log_err("wrong program count on query: %u", prog_cnt); + goto detach; + } + if (CHECK_FAIL(prog_ids[0] = 0)) { + log_err("invalid program id on query: %u", prog_ids[0]); + goto detach; + } + +detach: + detach_lookup_prog(lookup_prog); +close: + close(net_fd); +} + +static void run_lookup_prog(const struct test *t) +{ + int client_fd, server_fds[MAX_SERVERS] = { -1 }; + int i, err, server_idx; + + err = attach_lookup_prog(t->lookup_prog); + if (err) + return; + + for (i = 0; i < ARRAY_SIZE(server_fds); i++) { + server_fds[i] = make_server(t->sotype, t->recv_at.ip, + t->recv_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 detach; + + /* want just one server for non-reuseport test */ + if (!t->reuseport_prog) + break; + } + + client_fd = make_client(t->sotype, t->send_to.ip, t->send_to.port); + if (client_fd < 0) + goto close; + + /* reuseport prog always selects server B */ + server_idx = t->reuseport_prog ? SERVER_B : SERVER_A; + + if (t->sotype = SOCK_STREAM) + tcp_echo_test(client_fd, server_fds[server_idx]); + else + udp_echo_test(client_fd, server_fds[server_idx]); + + close(client_fd); +close: + for (i = 0; i < ARRAY_SIZE(server_fds); i++) + close(server_fds[i]); +detach: + detach_lookup_prog(t->lookup_prog); +} + +static void test_override_lookup(struct test_sk_lookup_kern *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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { INT_IP4, EXT_PORT }, + }, + { + .desc = "TCP IPv4 redir and reuseport", + .lookup_prog = skel->progs.select_sock_a, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { INT_IP4, INT_PORT }, + .reuseport_prog = skel->progs.select_sock_b, + }, + { + .desc = "TCP IPv6 redir port", + .lookup_prog = skel->progs.redir_port, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .recv_at = { INT_IP4_V6, INT_PORT }, + .send_to = { EXT_IP4, EXT_PORT }, + }, + { + .desc = "TCP IPv6 redir and reuseport", + .lookup_prog = skel->progs.select_sock_a, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_at = { INT_IP6, INT_PORT }, + .reuseport_prog = skel->progs.select_sock_b, + }, + { + .desc = "UDP IPv4 redir port", + .lookup_prog = skel->progs.redir_port, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { INT_IP4, EXT_PORT }, + }, + { + .desc = "UDP IPv4 redir and reuseport", + .lookup_prog = skel->progs.select_sock_a, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { INT_IP4, INT_PORT }, + .reuseport_prog = skel->progs.select_sock_b, + }, + { + .desc = "UDP IPv6 redir port", + .lookup_prog = skel->progs.redir_port, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .recv_at = { INT_IP4_V6, INT_PORT }, + .send_to = { EXT_IP4, EXT_PORT }, + }, + { + .desc = "UDP IPv6 redir and reuseport", + .lookup_prog = skel->progs.select_sock_a, + .sock_map = skel->maps.redir_map, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_at = { INT_IP6, INT_PORT }, + .reuseport_prog = skel->progs.select_sock_b, + }, + }; + 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 = { 0 }; + int client_fd, server_fd, err; + ssize_t n; + + if (attach_lookup_prog(t->lookup_prog)) + return; + + server_fd = make_server(t->sotype, t->recv_at.ip, t->recv_at.port, + t->reuseport_prog); + if (server_fd < 0) + goto detach; + + client_fd = make_socket_with_addr(t->sotype, t->send_to.ip, + t->send_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_FAIL(!err || errno != ECONNREFUSED)) + log_err("expected ECONNREFUSED on connect"); + +close_all: + close(client_fd); +close_srv: + close(server_fd); +detach: + detach_lookup_prog(t->lookup_prog); +} + +static void test_drop_on_lookup(struct test_sk_lookup_kern *skel) +{ + const struct test tests[] = { + { + .desc = "TCP IPv4 drop on lookup", + .lookup_prog = skel->progs.lookup_drop, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { EXT_IP4, EXT_PORT }, + }, + { + .desc = "TCP IPv6 drop on lookup", + .lookup_prog = skel->progs.lookup_drop, + .sotype = SOCK_STREAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_at = { EXT_IP6, EXT_PORT }, + }, + { + .desc = "UDP IPv4 drop on lookup", + .lookup_prog = skel->progs.lookup_drop, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_at = { EXT_IP4, EXT_PORT }, + }, + { + .desc = "UDP IPv6 drop on lookup", + .lookup_prog = skel->progs.lookup_drop, + .sotype = SOCK_DGRAM, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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; + ssize_t n; + + if (attach_lookup_prog(t->lookup_prog)) + return; + + server1 = make_server(t->sotype, t->recv_at.ip, t->recv_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->send_to.ip, t->send_to.port, + NULL /* reuseport prog */); + if (server2 < 0) + goto close_srv1; + + client = make_socket_with_addr(t->sotype, t->send_to.ip, + t->send_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_FAIL(!err || errno != ECONNREFUSED)) + log_err("expected ECONNREFUSED on connect"); + +close_all: + close(client); +close_srv2: + close(server2); +close_srv1: + close(server1); +detach: + detach_lookup_prog(t->lookup_prog); +} + +static void test_drop_on_reuseport(struct test_sk_lookup_kern *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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP4, EXT_PORT }, + .recv_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, + .send_to = { EXT_IP6, EXT_PORT }, + .recv_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_tests(struct test_sk_lookup_kern *skel) +{ + if (test__start_subtest("query lookup prog")) + query_lookup_prog(skel); + test_override_lookup(skel); + test_drop_on_lookup(skel); + test_drop_on_reuseport(skel); +} + +static int switch_netns(int *saved_net) +{ + static const char * const setup_script[] = { + "ip -6 addr add dev lo " EXT_IP6 "/128 nodad", + "ip -6 addr add dev lo " INT_IP6 "/128 nodad", + "ip link set dev lo up", + NULL, + }; + const char * const *cmd; + int net_fd, err; + + net_fd = open("/proc/self/ns/net", O_RDONLY); + if (CHECK_FAIL(net_fd < 0)) { + log_err("open(/proc/self/ns/net)"); + return -1; + } + + err = unshare(CLONE_NEWNET); + if (CHECK_FAIL(err)) { + log_err("unshare(CLONE_NEWNET)"); + goto close; + } + + for (cmd = setup_script; *cmd; cmd++) { + err = system(*cmd); + if (CHECK_FAIL(err)) { + log_err("system(%s)", *cmd); + goto close; + } + } + + *saved_net = net_fd; + return 0; + +close: + close(net_fd); + return -1; +} + +static void restore_netns(int saved_net) +{ + int err; + + err = setns(saved_net, CLONE_NEWNET); + if (CHECK_FAIL(err)) + log_err("setns(CLONE_NEWNET)"); + + close(saved_net); +} + +void test_sk_lookup(void) +{ + struct test_sk_lookup_kern *skel; + int err, saved_net; + + err = switch_netns(&saved_net); + if (err) + return; + + skel = test_sk_lookup_kern__open_and_load(); + if (CHECK_FAIL(!skel)) { + errno = 0; + log_err("failed to open and load BPF skeleton"); + goto restore_netns; + } + + run_tests(skel); + + test_sk_lookup_kern__destroy(skel); +restore_netns: + restore_netns(saved_net); +} diff --git a/tools/testing/selftests/bpf/progs/test_sk_lookup_kern.c b/tools/testing/selftests/bpf/progs/test_sk_lookup_kern.c new file mode 100644 index 000000000000..fc3ad9a69484 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_sk_lookup_kern.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause +// Copyright (c) 2020 Cloudflare + +#include +#include + +#include +#include + +#define IP4(a, b, c, d) \ + bpf_htonl((((__u32)(a) & 0xffU) << 24) | \ + (((__u32)(b) & 0xffU) << 16) | \ + (((__u32)(c) & 0xffU) << 8) | \ + (((__u32)(d) & 0xffU) << 0)) +#define IP6(aaaa, bbbb, cccc, dddd) \ + { bpf_htonl(aaaa), bpf_htonl(bbbb), bpf_htonl(cccc), bpf_htonl(dddd) } + +#define MAX_SOCKS 32 + +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(max_entries, MAX_SOCKS); + __type(key, __u32); + __type(value, __u64); +} redir_map SEC(".maps"); + +enum { + SERVER_A = 0, + SERVER_B = 1, +}; + +enum { + NO_FLAGS = 0, +}; + +static const __u32 DST_PORT = 7007; +static const __u32 DST_IP4 = IP4(127, 0, 0, 1); +static const __u32 DST_IP6[] = IP6(0xfd000000, 0x0, 0x0, 0x00000001); + +SEC("sk_lookup/lookup_pass") +int lookup_pass(struct bpf_sk_lookup *ctx) +{ + return BPF_OK; +} + +SEC("sk_lookup/lookup_drop") +int lookup_drop(struct bpf_sk_lookup *ctx) +{ + return BPF_DROP; +} + +SEC("sk_reuseport/reuse_pass") +int reuseport_pass(struct sk_reuseport_md *ctx) +{ + return SK_PASS; +} + +SEC("sk_reuseport/reuse_drop") +int reuseport_drop(struct sk_reuseport_md *ctx) +{ + return SK_DROP; +} + +/* Redirect packets destined for port DST_PORT to socket at redir_map[0]. */ +SEC("sk_lookup/redir_port") +int redir_port(struct bpf_sk_lookup *ctx) +{ + __u32 key = SERVER_A; + struct bpf_sock *sk; + int err; + + if (ctx->local_port != DST_PORT) + return BPF_OK; + + sk = bpf_map_lookup_elem(&redir_map, &key); + if (!sk) + return BPF_OK; + + err = bpf_sk_assign(ctx, sk, NO_FLAGS); + bpf_sk_release(sk); + return err ? BPF_DROP : BPF_REDIRECT; +} + +/* Redirect packets destined for DST_IP4 address to socket at redir_map[0]. */ +SEC("sk_lookup/redir_ip4") +int redir_ip4(struct bpf_sk_lookup *ctx) +{ + __u32 key = SERVER_A; + struct bpf_sock *sk; + int err; + + if (ctx->family != AF_INET) + return BPF_OK; + if (ctx->local_port != DST_PORT) + return BPF_OK; + if (ctx->local_ip4 != DST_IP4) + return BPF_OK; + + sk = bpf_map_lookup_elem(&redir_map, &key); + if (!sk) + return BPF_OK; + + err = bpf_sk_assign(ctx, sk, NO_FLAGS); + bpf_sk_release(sk); + return err ? BPF_DROP : BPF_REDIRECT; +} + +/* Redirect packets destined for DST_IP6 address to socket at redir_map[0]. */ +SEC("sk_lookup/redir_ip6") +int redir_ip6(struct bpf_sk_lookup *ctx) +{ + __u32 key = SERVER_A; + struct bpf_sock *sk; + int err; + + if (ctx->family != AF_INET6) + return BPF_OK; + if (ctx->local_port != DST_PORT) + return BPF_OK; + if (ctx->local_ip6[0] != DST_IP6[0] || + ctx->local_ip6[1] != DST_IP6[1] || + ctx->local_ip6[2] != DST_IP6[2] || + ctx->local_ip6[3] != DST_IP6[3]) + return BPF_OK; + + sk = bpf_map_lookup_elem(&redir_map, &key); + if (!sk) + return BPF_OK; + + err = bpf_sk_assign(ctx, sk, NO_FLAGS); + bpf_sk_release(sk); + return err ? BPF_DROP : BPF_REDIRECT; +} + +SEC("sk_lookup/select_sock_a") +int select_sock_a(struct bpf_sk_lookup *ctx) +{ + __u32 key = SERVER_A; + struct bpf_sock *sk; + int err; + + sk = bpf_map_lookup_elem(&redir_map, &key); + if (!sk) + return BPF_OK; + + err = bpf_sk_assign(ctx, sk, NO_FLAGS); + bpf_sk_release(sk); + return err ? BPF_DROP : BPF_REDIRECT; +} + +SEC("sk_reuseport/select_sock_b") +int select_sock_b(struct sk_reuseport_md *ctx) +{ + __u32 key = SERVER_B; + int err; + + err = bpf_sk_select_reuseport(ctx, &redir_map, &key, NO_FLAGS); + return err ? SK_DROP : SK_PASS; +} + +char _license[] SEC("license") = "Dual BSD/GPL"; +__u32 _version SEC("version") = 1; -- 2.25.3