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 <linux/compiler.h>
 13#include <bpf/libbpf.h>
 14
 15#include "network_helpers.h"
 16#include "test_progs.h"
 17#include "test_btf_skc_cls_ingress.skel.h"
 18
 19static struct test_btf_skc_cls_ingress *skel;
 20static struct sockaddr_in6 srv_sa6;
 21static __u32 duration;
 22
 23#define PROG_PIN_FILE "/sys/fs/bpf/btf_skc_cls_ingress"
 24
 25static int write_sysctl(const char *sysctl, const char *value)
 26{
 27	int fd, err, len;
 28
 29	fd = open(sysctl, O_WRONLY);
 30	if (CHECK(fd == -1, "open sysctl", "open(%s): %s (%d)\n",
 31		  sysctl, strerror(errno), errno))
 32		return -1;
 33
 34	len = strlen(value);
 35	err = write(fd, value, len);
 36	close(fd);
 37	if (CHECK(err != len, "write sysctl",
 38		  "write(%s, %s, %d): err:%d %s (%d)\n",
 39		  sysctl, value, len, err, strerror(errno), errno))
 40		return -1;
 41
 42	return 0;
 43}
 44
 45static int prepare_netns(void)
 46{
 47	if (CHECK(unshare(CLONE_NEWNET), "create netns",
 48		  "unshare(CLONE_NEWNET): %s (%d)",
 49		  strerror(errno), errno))
 50		return -1;
 51
 52	if (CHECK(system("ip link set dev lo up"),
 53		  "ip link set dev lo up", "failed\n"))
 54		return -1;
 55
 56	if (CHECK(system("tc qdisc add dev lo clsact"),
 57		  "tc qdisc add dev lo clsact", "failed\n"))
 58		return -1;
 59
 60	if (CHECK(system("tc filter add dev lo ingress bpf direct-action object-pinned " PROG_PIN_FILE),
 61		  "install tc cls-prog at ingress", "failed\n"))
 62		return -1;
 63
 64	/* Ensure 20 bytes options (i.e. in total 40 bytes tcp header) for the
 65	 * bpf_tcp_gen_syncookie() helper.
 66	 */
 67	if (write_sysctl("/proc/sys/net/ipv4/tcp_window_scaling", "1") ||
 68	    write_sysctl("/proc/sys/net/ipv4/tcp_timestamps", "1") ||
 69	    write_sysctl("/proc/sys/net/ipv4/tcp_sack", "1"))
 70		return -1;
 71
 72	return 0;
 73}
 74
 75static void reset_test(void)
 76{
 77	memset(&skel->bss->srv_sa6, 0, sizeof(skel->bss->srv_sa6));
 78	skel->bss->listen_tp_sport = 0;
 79	skel->bss->req_sk_sport = 0;
 80	skel->bss->recv_cookie = 0;
 81	skel->bss->gen_cookie = 0;
 82	skel->bss->linum = 0;
 83}
 84
 85static void print_err_line(void)
 86{
 87	if (skel->bss->linum)
 88		printf("bpf prog error at line %u\n", skel->bss->linum);
 89}
 90
 91static void test_conn(void)
 92{
 93	int listen_fd = -1, cli_fd = -1, err;
 94	socklen_t addrlen = sizeof(srv_sa6);
 95	int srv_port;
 96
 97	if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "1"))
 98		return;
 99
100	listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
101	if (CHECK_FAIL(listen_fd == -1))
102		return;
103
104	err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
105	if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
106		  errno))
107		goto done;
108	memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
109	srv_port = ntohs(srv_sa6.sin6_port);
110
111	cli_fd = connect_to_fd(listen_fd, 0);
112	if (CHECK_FAIL(cli_fd == -1))
113		goto done;
114
115	if (CHECK(skel->bss->listen_tp_sport != srv_port ||
116		  skel->bss->req_sk_sport != srv_port,
117		  "Unexpected sk src port",
118		  "listen_tp_sport:%u req_sk_sport:%u expected:%u\n",
119		  skel->bss->listen_tp_sport, skel->bss->req_sk_sport,
120		  srv_port))
121		goto done;
122
123	if (CHECK(skel->bss->gen_cookie || skel->bss->recv_cookie,
124		  "Unexpected syncookie states",
125		  "gen_cookie:%u recv_cookie:%u\n",
126		  skel->bss->gen_cookie, skel->bss->recv_cookie))
127		goto done;
128
129	CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
130	      skel->bss->linum);
131
132done:
133	if (listen_fd != -1)
134		close(listen_fd);
135	if (cli_fd != -1)
136		close(cli_fd);
137}
138
139static void test_syncookie(void)
140{
141	int listen_fd = -1, cli_fd = -1, err;
142	socklen_t addrlen = sizeof(srv_sa6);
143	int srv_port;
144
145	/* Enforce syncookie mode */
146	if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "2"))
147		return;
148
149	listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
150	if (CHECK_FAIL(listen_fd == -1))
151		return;
152
153	err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
154	if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
155		  errno))
156		goto done;
157	memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
158	srv_port = ntohs(srv_sa6.sin6_port);
159
160	cli_fd = connect_to_fd(listen_fd, 0);
161	if (CHECK_FAIL(cli_fd == -1))
162		goto done;
163
164	if (CHECK(skel->bss->listen_tp_sport != srv_port,
165		  "Unexpected tp src port",
166		  "listen_tp_sport:%u expected:%u\n",
167		  skel->bss->listen_tp_sport, srv_port))
168		goto done;
169
170	if (CHECK(skel->bss->req_sk_sport,
171		  "Unexpected req_sk src port",
172		  "req_sk_sport:%u expected:0\n",
173		   skel->bss->req_sk_sport))
174		goto done;
175
176	if (CHECK(!skel->bss->gen_cookie ||
177		  skel->bss->gen_cookie != skel->bss->recv_cookie,
178		  "Unexpected syncookie states",
179		  "gen_cookie:%u recv_cookie:%u\n",
180		  skel->bss->gen_cookie, skel->bss->recv_cookie))
181		goto done;
182
183	CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
184	      skel->bss->linum);
185
186done:
187	if (listen_fd != -1)
188		close(listen_fd);
189	if (cli_fd != -1)
190		close(cli_fd);
191}
192
193struct test {
194	const char *desc;
195	void (*run)(void);
196};
197
198#define DEF_TEST(name) { #name, test_##name }
199static struct test tests[] = {
200	DEF_TEST(conn),
201	DEF_TEST(syncookie),
202};
203
204void test_btf_skc_cls_ingress(void)
205{
206	int i, err;
207
208	skel = test_btf_skc_cls_ingress__open_and_load();
209	if (CHECK(!skel, "test_btf_skc_cls_ingress__open_and_load", "failed\n"))
210		return;
211
212	err = bpf_program__pin(skel->progs.cls_ingress, PROG_PIN_FILE);
213	if (CHECK(err, "bpf_program__pin",
214		  "cannot pin bpf prog to %s. err:%d\n", PROG_PIN_FILE, err)) {
215		test_btf_skc_cls_ingress__destroy(skel);
216		return;
217	}
218
219	for (i = 0; i < ARRAY_SIZE(tests); i++) {
220		if (!test__start_subtest(tests[i].desc))
221			continue;
222
223		if (prepare_netns())
224			break;
225
226		tests[i].run();
227
228		print_err_line();
229		reset_test();
230	}
231
232	bpf_program__unpin(skel->progs.cls_ingress, PROG_PIN_FILE);
233	test_btf_skc_cls_ingress__destroy(skel);
234}