1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright (c) 2020 Facebook */
  3
  4#define _GNU_SOURCE
  5#include <netinet/in.h>
  6#include <arpa/inet.h>
  7#include <unistd.h>
  8#include <stdlib.h>
  9#include <string.h>
 10#include <errno.h>
 11#include <sched.h>
 12#include <net/if.h>
 13#include <linux/compiler.h>
 14#include <bpf/libbpf.h>
 15
 16#include "network_helpers.h"
 17#include "test_progs.h"
 18#include "test_btf_skc_cls_ingress.skel.h"
 19
 20static struct test_btf_skc_cls_ingress *skel;
 21static struct sockaddr_in6 srv_sa6;
 22static __u32 duration;
 23
 24static int prepare_netns(void)
 25{
 26	LIBBPF_OPTS(bpf_tc_hook, qdisc_lo, .attach_point = BPF_TC_INGRESS);
 27	LIBBPF_OPTS(bpf_tc_opts, tc_attach,
 28		    .prog_fd = bpf_program__fd(skel->progs.cls_ingress));
 29
 30	if (CHECK(unshare(CLONE_NEWNET), "create netns",
 31		  "unshare(CLONE_NEWNET): %s (%d)",
 32		  strerror(errno), errno))
 33		return -1;
 34
 35	if (CHECK(system("ip link set dev lo up"),
 36		  "ip link set dev lo up", "failed\n"))
 37		return -1;
 38
 39	qdisc_lo.ifindex = if_nametoindex("lo");
 40	if (!ASSERT_OK(bpf_tc_hook_create(&qdisc_lo), "qdisc add dev lo clsact"))
 41		return -1;
 42
 43	if (!ASSERT_OK(bpf_tc_attach(&qdisc_lo, &tc_attach),
 44		       "filter add dev lo ingress"))
 45		return -1;
 46
 47	/* Ensure 20 bytes options (i.e. in total 40 bytes tcp header) for the
 48	 * bpf_tcp_gen_syncookie() helper.
 49	 */
 50	if (write_sysctl("/proc/sys/net/ipv4/tcp_window_scaling", "1") ||
 51	    write_sysctl("/proc/sys/net/ipv4/tcp_timestamps", "1") ||
 52	    write_sysctl("/proc/sys/net/ipv4/tcp_sack", "1"))
 53		return -1;
 54
 55	return 0;
 56}
 57
 58static void reset_test(void)
 59{
 60	memset(&skel->bss->srv_sa6, 0, sizeof(skel->bss->srv_sa6));
 61	skel->bss->listen_tp_sport = 0;
 62	skel->bss->req_sk_sport = 0;
 63	skel->bss->recv_cookie = 0;
 64	skel->bss->gen_cookie = 0;
 65	skel->bss->linum = 0;
 66}
 67
 68static void print_err_line(void)
 69{
 70	if (skel->bss->linum)
 71		printf("bpf prog error at line %u\n", skel->bss->linum);
 72}
 73
 74static void test_conn(void)
 75{
 76	int listen_fd = -1, cli_fd = -1, srv_fd = -1, err;
 77	socklen_t addrlen = sizeof(srv_sa6);
 78	int srv_port;
 79
 80	if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "1"))
 81		return;
 82
 83	listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
 84	if (CHECK_FAIL(listen_fd == -1))
 85		return;
 86
 87	err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
 88	if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
 89		  errno))
 90		goto done;
 91	memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
 92	srv_port = ntohs(srv_sa6.sin6_port);
 93
 94	cli_fd = connect_to_fd(listen_fd, 0);
 95	if (CHECK_FAIL(cli_fd == -1))
 96		goto done;
 97
 98	srv_fd = accept(listen_fd, NULL, NULL);
 99	if (CHECK_FAIL(srv_fd == -1))
100		goto done;
101
102	if (CHECK(skel->bss->listen_tp_sport != srv_port ||
103		  skel->bss->req_sk_sport != srv_port,
104		  "Unexpected sk src port",
105		  "listen_tp_sport:%u req_sk_sport:%u expected:%u\n",
106		  skel->bss->listen_tp_sport, skel->bss->req_sk_sport,
107		  srv_port))
108		goto done;
109
110	if (CHECK(skel->bss->gen_cookie || skel->bss->recv_cookie,
111		  "Unexpected syncookie states",
112		  "gen_cookie:%u recv_cookie:%u\n",
113		  skel->bss->gen_cookie, skel->bss->recv_cookie))
114		goto done;
115
116	CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
117	      skel->bss->linum);
118
119done:
120	if (listen_fd != -1)
121		close(listen_fd);
122	if (cli_fd != -1)
123		close(cli_fd);
124	if (srv_fd != -1)
125		close(srv_fd);
126}
127
128static void test_syncookie(void)
129{
130	int listen_fd = -1, cli_fd = -1, srv_fd = -1, err;
131	socklen_t addrlen = sizeof(srv_sa6);
132	int srv_port;
133
134	/* Enforce syncookie mode */
135	if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "2"))
136		return;
137
138	listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
139	if (CHECK_FAIL(listen_fd == -1))
140		return;
141
142	err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
143	if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
144		  errno))
145		goto done;
146	memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
147	srv_port = ntohs(srv_sa6.sin6_port);
148
149	cli_fd = connect_to_fd(listen_fd, 0);
150	if (CHECK_FAIL(cli_fd == -1))
151		goto done;
152
153	srv_fd = accept(listen_fd, NULL, NULL);
154	if (CHECK_FAIL(srv_fd == -1))
155		goto done;
156
157	if (CHECK(skel->bss->listen_tp_sport != srv_port,
158		  "Unexpected tp src port",
159		  "listen_tp_sport:%u expected:%u\n",
160		  skel->bss->listen_tp_sport, srv_port))
161		goto done;
162
163	if (CHECK(skel->bss->req_sk_sport,
164		  "Unexpected req_sk src port",
165		  "req_sk_sport:%u expected:0\n",
166		   skel->bss->req_sk_sport))
167		goto done;
168
169	if (CHECK(!skel->bss->gen_cookie ||
170		  skel->bss->gen_cookie != skel->bss->recv_cookie,
171		  "Unexpected syncookie states",
172		  "gen_cookie:%u recv_cookie:%u\n",
173		  skel->bss->gen_cookie, skel->bss->recv_cookie))
174		goto done;
175
176	CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
177	      skel->bss->linum);
178
179done:
180	if (listen_fd != -1)
181		close(listen_fd);
182	if (cli_fd != -1)
183		close(cli_fd);
184	if (srv_fd != -1)
185		close(srv_fd);
186}
187
188struct test {
189	const char *desc;
190	void (*run)(void);
191};
192
193#define DEF_TEST(name) { #name, test_##name }
194static struct test tests[] = {
195	DEF_TEST(conn),
196	DEF_TEST(syncookie),
197};
198
199void test_btf_skc_cls_ingress(void)
200{
201	int i;
202
203	skel = test_btf_skc_cls_ingress__open_and_load();
204	if (CHECK(!skel, "test_btf_skc_cls_ingress__open_and_load", "failed\n"))
205		return;
206
207	for (i = 0; i < ARRAY_SIZE(tests); i++) {
208		if (!test__start_subtest(tests[i].desc))
209			continue;
210
211		if (prepare_netns())
212			break;
213
214		tests[i].run();
215
216		print_err_line();
217		reset_test();
218	}
219
220	test_btf_skc_cls_ingress__destroy(skel);
221}