selftests/bpf: bpf_setsockopt tests

This patch adds tests to exercise optnames that are allowed
in bpf_setsockopt().
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061847.4182339-1-kafai@fb.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/prog_tests/setget_sockopt.c

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
+#define _GNU_SOURCE
+#include <sched.h>
+#include <linux/socket.h>
+#include <net/if.h>
+
+#include "test_progs.h"
+#include "cgroup_helpers.h"
+#include "network_helpers.h"
+
+#include "setget_sockopt.skel.h"
+
+#define CG_NAME "/setget-sockopt-test"
+
+static const char addr4_str[] = "127.0.0.1";
+static const char addr6_str[] = "::1";
+static struct setget_sockopt *skel;
+static int cg_fd;
+
+static int create_netns(void)
+{
+	if (!ASSERT_OK(unshare(CLONE_NEWNET), "create netns"))
+		return -1;
+
+	if (!ASSERT_OK(system("ip link set dev lo up"), "set lo up"))
+		return -1;
+
+	if (!ASSERT_OK(system("ip link add dev binddevtest1 type veth peer name binddevtest2"),
+		       "add veth"))
+		return -1;
+
+	if (!ASSERT_OK(system("ip link set dev binddevtest1 up"),
+		       "bring veth up"))
+		return -1;
+
+	return 0;
+}
+
+static void test_tcp(int family)
+{
+	struct setget_sockopt__bss *bss = skel->bss;
+	int sfd, cfd;
+
+	memset(bss, 0, sizeof(*bss));
+
+	sfd = start_server(family, SOCK_STREAM,
+			   family == AF_INET6 ? addr6_str : addr4_str, 0, 0);
+	if (!ASSERT_GE(sfd, 0, "start_server"))
+		return;
+
+	cfd = connect_to_fd(sfd, 0);
+	if (!ASSERT_GE(cfd, 0, "connect_to_fd_server")) {
+		close(sfd);
+		return;
+	}
+	close(sfd);
+	close(cfd);
+
+	ASSERT_EQ(bss->nr_listen, 1, "nr_listen");
+	ASSERT_EQ(bss->nr_connect, 1, "nr_connect");
+	ASSERT_EQ(bss->nr_active, 1, "nr_active");
+	ASSERT_EQ(bss->nr_passive, 1, "nr_passive");
+	ASSERT_EQ(bss->nr_socket_post_create, 2, "nr_socket_post_create");
+	ASSERT_EQ(bss->nr_binddev, 2, "nr_bind");
+}
+
+static void test_udp(int family)
+{
+	struct setget_sockopt__bss *bss = skel->bss;
+	int sfd;
+
+	memset(bss, 0, sizeof(*bss));
+
+	sfd = start_server(family, SOCK_DGRAM,
+			   family == AF_INET6 ? addr6_str : addr4_str, 0, 0);
+	if (!ASSERT_GE(sfd, 0, "start_server"))
+		return;
+	close(sfd);
+
+	ASSERT_GE(bss->nr_socket_post_create, 1, "nr_socket_post_create");
+	ASSERT_EQ(bss->nr_binddev, 1, "nr_bind");
+}
+
+void test_setget_sockopt(void)
+{
+	cg_fd = test__join_cgroup(CG_NAME);
+	if (cg_fd < 0)
+		return;
+
+	if (create_netns())
+		goto done;
+
+	skel = setget_sockopt__open();
+	if (!ASSERT_OK_PTR(skel, "open skel"))
+		goto done;
+
+	strcpy(skel->rodata->veth, "binddevtest1");
+	skel->rodata->veth_ifindex = if_nametoindex("binddevtest1");
+	if (!ASSERT_GT(skel->rodata->veth_ifindex, 0, "if_nametoindex"))
+		goto done;
+
+	if (!ASSERT_OK(setget_sockopt__load(skel), "load skel"))
+		goto done;
+
+	skel->links.skops_sockopt =
+		bpf_program__attach_cgroup(skel->progs.skops_sockopt, cg_fd);
+	if (!ASSERT_OK_PTR(skel->links.skops_sockopt, "attach cgroup"))
+		goto done;
+
+	skel->links.socket_post_create =
+		bpf_program__attach_cgroup(skel->progs.socket_post_create, cg_fd);
+	if (!ASSERT_OK_PTR(skel->links.socket_post_create, "attach_cgroup"))
+		goto done;
+
+	test_tcp(AF_INET6);
+	test_tcp(AF_INET);
+	test_udp(AF_INET6);
+	test_udp(AF_INET);
+
+done:
+	setget_sockopt__destroy(skel);
+	close(cg_fd);
+}

tools/testing/selftests/bpf/progs/bpf_tracing_net.h

@@ -6,13 +6,40 @@
 #define AF_INET6		10
 
 #define SOL_SOCKET		1
+#define SO_REUSEADDR		2
 #define SO_SNDBUF		7
-#define __SO_ACCEPTCON		(1 << 16)
+#define SO_RCVBUF		8
+#define SO_KEEPALIVE		9
 #define SO_PRIORITY		12
+#define SO_REUSEPORT		15
+#define SO_RCVLOWAT		18
+#define SO_BINDTODEVICE		25
+#define SO_MARK			36
+#define SO_MAX_PACING_RATE	47
+#define SO_BINDTOIFINDEX	62
+#define SO_TXREHASH		74
+#define __SO_ACCEPTCON		(1 << 16)
+
+#define IP_TOS			1
+
+#define IPV6_TCLASS		67
+#define IPV6_AUTOFLOWLABEL	70
 
 #define SOL_TCP			6
+#define TCP_NODELAY		1
+#define TCP_MAXSEG		2
+#define TCP_KEEPIDLE		4
+#define TCP_KEEPINTVL		5
+#define TCP_KEEPCNT		6
+#define TCP_SYNCNT		7
+#define TCP_WINDOW_CLAMP	10
 #define TCP_CONGESTION		13
+#define TCP_THIN_LINEAR_TIMEOUTS	16
+#define TCP_USER_TIMEOUT	18
+#define TCP_NOTSENT_LOWAT	25
+#define TCP_SAVE_SYN		27
 #define TCP_CA_NAME_MAX		16
+#define TCP_NAGLE_OFF		1
 
 #define ICSK_TIME_RETRANS	1
 #define ICSK_TIME_PROBE0	3
@@ -49,6 +76,8 @@
 #define sk_state		__sk_common.skc_state
 #define sk_v6_daddr		__sk_common.skc_v6_daddr
 #define sk_v6_rcv_saddr		__sk_common.skc_v6_rcv_saddr
+#define sk_flags		__sk_common.skc_flags
+#define sk_reuse		__sk_common.skc_reuse
 
 #define s6_addr32		in6_u.u6_addr32
 

tools/testing/selftests/bpf/progs/setget_sockopt.c

+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include "bpf_tracing_net.h"
+#include <bpf/bpf_core_read.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+extern unsigned long CONFIG_HZ __kconfig;
+
+const volatile char veth[IFNAMSIZ];
+const volatile int veth_ifindex;
+
+int nr_listen;
+int nr_passive;
+int nr_active;
+int nr_connect;
+int nr_binddev;
+int nr_socket_post_create;
+
+struct sockopt_test {
+	int opt;
+	int new;
+	int restore;
+	int expected;
+	int tcp_expected;
+	unsigned int flip:1;
+};
+
+static const char cubic_cc[] = "cubic";
+static const char reno_cc[] = "reno";
+
+static const struct sockopt_test sol_socket_tests[] = {
+	{ .opt = SO_REUSEADDR, .flip = 1, },
+	{ .opt = SO_SNDBUF, .new = 8123, .expected = 8123 * 2, },
+	{ .opt = SO_RCVBUF, .new = 8123, .expected = 8123 * 2, },
+	{ .opt = SO_KEEPALIVE, .flip = 1, },
+	{ .opt = SO_PRIORITY, .new = 0xeb9f, .expected = 0xeb9f, },
+	{ .opt = SO_REUSEPORT, .flip = 1, },
+	{ .opt = SO_RCVLOWAT, .new = 8123, .expected = 8123, },
+	{ .opt = SO_MARK, .new = 0xeb9f, .expected = 0xeb9f, },
+	{ .opt = SO_MAX_PACING_RATE, .new = 0xeb9f, .expected = 0xeb9f, },
+	{ .opt = SO_TXREHASH, .flip = 1, },
+	{ .opt = 0, },
+};
+
+static const struct sockopt_test sol_tcp_tests[] = {
+	{ .opt = TCP_NODELAY, .flip = 1, },
+	{ .opt = TCP_MAXSEG, .new = 1314, .expected = 1314, },
+	{ .opt = TCP_KEEPIDLE, .new = 123, .expected = 123, .restore = 321, },
+	{ .opt = TCP_KEEPINTVL, .new = 123, .expected = 123, .restore = 321, },
+	{ .opt = TCP_KEEPCNT, .new = 123, .expected = 123, .restore = 124, },
+	{ .opt = TCP_SYNCNT, .new = 123, .expected = 123, .restore = 124, },
+	{ .opt = TCP_WINDOW_CLAMP, .new = 8123, .expected = 8123, .restore = 8124, },
+	{ .opt = TCP_CONGESTION, },
+	{ .opt = TCP_THIN_LINEAR_TIMEOUTS, .flip = 1, },
+	{ .opt = TCP_USER_TIMEOUT, .new = 123400, .expected = 123400, },
+	{ .opt = TCP_NOTSENT_LOWAT, .new = 1314, .expected = 1314, },
+	{ .opt = TCP_SAVE_SYN, .new = 1, .expected = 1, },
+	{ .opt = 0, },
+};
+
+static const struct sockopt_test sol_ip_tests[] = {
+	{ .opt = IP_TOS, .new = 0xe1, .expected = 0xe1, .tcp_expected = 0xe0, },
+	{ .opt = 0, },
+};
+
+static const struct sockopt_test sol_ipv6_tests[] = {
+	{ .opt = IPV6_TCLASS, .new = 0xe1, .expected = 0xe1, .tcp_expected = 0xe0, },
+	{ .opt = IPV6_AUTOFLOWLABEL, .flip = 1, },
+	{ .opt = 0, },
+};
+
+struct loop_ctx {
+	void *ctx;
+	struct sock *sk;
+};
+
+static int __bpf_getsockopt(void *ctx, struct sock *sk,
+			    int level, int opt, int *optval,
+			    int optlen)
+{
+	if (level == SOL_SOCKET) {
+		switch (opt) {
+		case SO_REUSEADDR:
+			*optval = !!BPF_CORE_READ_BITFIELD(sk, sk_reuse);
+			break;
+		case SO_KEEPALIVE:
+			*optval = !!(sk->sk_flags & (1UL << 3));
+			break;
+		case SO_RCVLOWAT:
+			*optval = sk->sk_rcvlowat;
+			break;
+		case SO_MAX_PACING_RATE:
+			*optval = sk->sk_max_pacing_rate;
+			break;
+		default:
+			return bpf_getsockopt(ctx, level, opt, optval, optlen);
+		}
+		return 0;
+	}
+
+	if (level == IPPROTO_TCP) {
+		struct tcp_sock *tp = bpf_skc_to_tcp_sock(sk);
+
+		if (!tp)
+			return -1;
+
+		switch (opt) {
+		case TCP_NODELAY:
+			*optval = !!(BPF_CORE_READ_BITFIELD(tp, nonagle) & TCP_NAGLE_OFF);
+			break;
+		case TCP_MAXSEG:
+			*optval = tp->rx_opt.user_mss;
+			break;
+		case TCP_KEEPIDLE:
+			*optval = tp->keepalive_time / CONFIG_HZ;
+			break;
+		case TCP_SYNCNT:
+			*optval = tp->inet_conn.icsk_syn_retries;
+			break;
+		case TCP_KEEPINTVL:
+			*optval = tp->keepalive_intvl / CONFIG_HZ;
+			break;
+		case TCP_KEEPCNT:
+			*optval = tp->keepalive_probes;
+			break;
+		case TCP_WINDOW_CLAMP:
+			*optval = tp->window_clamp;
+			break;
+		case TCP_THIN_LINEAR_TIMEOUTS:
+			*optval = !!BPF_CORE_READ_BITFIELD(tp, thin_lto);
+			break;
+		case TCP_USER_TIMEOUT:
+			*optval = tp->inet_conn.icsk_user_timeout;
+			break;
+		case TCP_NOTSENT_LOWAT:
+			*optval = tp->notsent_lowat;
+			break;
+		case TCP_SAVE_SYN:
+			*optval = BPF_CORE_READ_BITFIELD(tp, save_syn);
+			break;
+		default:
+			return bpf_getsockopt(ctx, level, opt, optval, optlen);
+		}
+		return 0;
+	}
+
+	if (level == IPPROTO_IPV6) {
+		switch (opt) {
+		case IPV6_AUTOFLOWLABEL: {
+			__u16 proto = sk->sk_protocol;
+			struct inet_sock *inet_sk;
+
+			if (proto == IPPROTO_TCP)
+				inet_sk = (struct inet_sock *)bpf_skc_to_tcp_sock(sk);
+			else
+				inet_sk = (struct inet_sock *)bpf_skc_to_udp6_sock(sk);
+
+			if (!inet_sk)
+				return -1;
+
+			*optval = !!inet_sk->pinet6->autoflowlabel;
+			break;
+		}
+		default:
+			return bpf_getsockopt(ctx, level, opt, optval, optlen);
+		}
+		return 0;
+	}
+
+	return bpf_getsockopt(ctx, level, opt, optval, optlen);
+}
+
+static int bpf_test_sockopt_flip(void *ctx, struct sock *sk,
+				 const struct sockopt_test *t,
+				 int level)
+{
+	int old, tmp, new, opt = t->opt;
+
+	opt = t->opt;
+
+	if (__bpf_getsockopt(ctx, sk, level, opt, &old, sizeof(old)))
+		return 1;
+	/* kernel initialized txrehash to 255 */
+	if (level == SOL_SOCKET && opt == SO_TXREHASH && old != 0 && old != 1)
+		old = 1;
+
+	new = !old;
+	if (bpf_setsockopt(ctx, level, opt, &new, sizeof(new)))
+		return 1;
+	if (__bpf_getsockopt(ctx, sk, level, opt, &tmp, sizeof(tmp)) ||
+	    tmp != new)
+		return 1;
+
+	if (bpf_setsockopt(ctx, level, opt, &old, sizeof(old)))
+		return 1;
+
+	return 0;
+}
+
+static int bpf_test_sockopt_int(void *ctx, struct sock *sk,
+				const struct sockopt_test *t,
+				int level)
+{
+	int old, tmp, new, expected, opt;
+
+	opt = t->opt;
+	new = t->new;
+	if (sk->sk_type == SOCK_STREAM && t->tcp_expected)
+		expected = t->tcp_expected;
+	else
+		expected = t->expected;
+
+	if (__bpf_getsockopt(ctx, sk, level, opt, &old, sizeof(old)) ||
+	    old == new)
+		return 1;
+
+	if (bpf_setsockopt(ctx, level, opt, &new, sizeof(new)))
+		return 1;
+	if (__bpf_getsockopt(ctx, sk, level, opt, &tmp, sizeof(tmp)) ||
+	    tmp != expected)
+		return 1;
+
+	if (t->restore)
+		old = t->restore;
+	if (bpf_setsockopt(ctx, level, opt, &old, sizeof(old)))
+		return 1;
+
+	return 0;
+}
+
+static int bpf_test_socket_sockopt(__u32 i, struct loop_ctx *lc)
+{
+	const struct sockopt_test *t;
+
+	if (i >= ARRAY_SIZE(sol_socket_tests))
+		return 1;
+
+	t = &sol_socket_tests[i];
+	if (!t->opt)
+		return 1;
+
+	if (t->flip)
+		return bpf_test_sockopt_flip(lc->ctx, lc->sk, t, SOL_SOCKET);
+
+	return bpf_test_sockopt_int(lc->ctx, lc->sk, t, SOL_SOCKET);
+}
+
+static int bpf_test_ip_sockopt(__u32 i, struct loop_ctx *lc)
+{
+	const struct sockopt_test *t;
+
+	if (i >= ARRAY_SIZE(sol_ip_tests))
+		return 1;
+
+	t = &sol_ip_tests[i];
+	if (!t->opt)
+		return 1;
+
+	if (t->flip)
+		return bpf_test_sockopt_flip(lc->ctx, lc->sk, t, IPPROTO_IP);
+
+	return bpf_test_sockopt_int(lc->ctx, lc->sk, t, IPPROTO_IP);
+}
+
+static int bpf_test_ipv6_sockopt(__u32 i, struct loop_ctx *lc)
+{
+	const struct sockopt_test *t;
+
+	if (i >= ARRAY_SIZE(sol_ipv6_tests))
+		return 1;
+
+	t = &sol_ipv6_tests[i];
+	if (!t->opt)
+		return 1;
+
+	if (t->flip)
+		return bpf_test_sockopt_flip(lc->ctx, lc->sk, t, IPPROTO_IPV6);
+
+	return bpf_test_sockopt_int(lc->ctx, lc->sk, t, IPPROTO_IPV6);
+}
+
+static int bpf_test_tcp_sockopt(__u32 i, struct loop_ctx *lc)
+{
+	const struct sockopt_test *t;
+	struct sock *sk;
+	void *ctx;
+
+	if (i >= ARRAY_SIZE(sol_tcp_tests))
+		return 1;
+
+	t = &sol_tcp_tests[i];
+	if (!t->opt)
+		return 1;
+
+	ctx = lc->ctx;
+	sk = lc->sk;
+
+	if (t->opt == TCP_CONGESTION) {
+		char old_cc[16], tmp_cc[16];
+		const char *new_cc;
+
+		if (bpf_getsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, old_cc, sizeof(old_cc)))
+			return 1;
+		if (!bpf_strncmp(old_cc, sizeof(old_cc), cubic_cc))
+			new_cc = reno_cc;
+		else
+			new_cc = cubic_cc;
+		if (bpf_setsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, (void *)new_cc,
+				   sizeof(new_cc)))
+			return 1;
+		if (bpf_getsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, tmp_cc, sizeof(tmp_cc)))
+			return 1;
+		if (bpf_strncmp(tmp_cc, sizeof(tmp_cc), new_cc))
+			return 1;
+		if (bpf_setsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, old_cc, sizeof(old_cc)))
+			return 1;
+		return 0;
+	}
+
+	if (t->flip)
+		return bpf_test_sockopt_flip(ctx, sk, t, IPPROTO_TCP);
+
+	return bpf_test_sockopt_int(ctx, sk, t, IPPROTO_TCP);
+}
+
+static int bpf_test_sockopt(void *ctx, struct sock *sk)
+{
+	struct loop_ctx lc = { .ctx = ctx, .sk = sk, };
+	__u16 family, proto;
+	int n;
+
+	family = sk->sk_family;
+	proto = sk->sk_protocol;
+
+	n = bpf_loop(ARRAY_SIZE(sol_socket_tests), bpf_test_socket_sockopt, &lc, 0);
+	if (n != ARRAY_SIZE(sol_socket_tests))
+		return -1;
+
+	if (proto == IPPROTO_TCP) {
+		n = bpf_loop(ARRAY_SIZE(sol_tcp_tests), bpf_test_tcp_sockopt, &lc, 0);
+		if (n != ARRAY_SIZE(sol_tcp_tests))
+			return -1;
+	}
+
+	if (family == AF_INET) {
+		n = bpf_loop(ARRAY_SIZE(sol_ip_tests), bpf_test_ip_sockopt, &lc, 0);
+		if (n != ARRAY_SIZE(sol_ip_tests))
+			return -1;
+	} else {
+		n = bpf_loop(ARRAY_SIZE(sol_ipv6_tests), bpf_test_ipv6_sockopt, &lc, 0);
+		if (n != ARRAY_SIZE(sol_ipv6_tests))
+			return -1;
+	}
+
+	return 0;
+}
+
+static int binddev_test(void *ctx)
+{
+	const char empty_ifname[] = "";
+	int ifindex, zero = 0;
+
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+			   (void *)veth, sizeof(veth)))
+		return -1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &ifindex, sizeof(int)) ||
+	    ifindex != veth_ifindex)
+		return -1;
+
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+			   (void *)empty_ifname, sizeof(empty_ifname)))
+		return -1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &ifindex, sizeof(int)) ||
+	    ifindex != 0)
+		return -1;
+
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   (void *)&veth_ifindex, sizeof(int)))
+		return -1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &ifindex, sizeof(int)) ||
+	    ifindex != veth_ifindex)
+		return -1;
+
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &zero, sizeof(int)))
+		return -1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &ifindex, sizeof(int)) ||
+	    ifindex != 0)
+		return -1;
+
+	return 0;
+}
+
+SEC("lsm_cgroup/socket_post_create")
+int BPF_PROG(socket_post_create, struct socket *sock, int family,
+	     int type, int protocol, int kern)
+{
+	struct sock *sk = sock->sk;
+
+	if (!sk)
+		return 1;
+
+	nr_socket_post_create += !bpf_test_sockopt(sk, sk);
+	nr_binddev += !binddev_test(sk);
+
+	return 1;
+}
+
+SEC("sockops")
+int skops_sockopt(struct bpf_sock_ops *skops)
+{
+	struct bpf_sock *bpf_sk = skops->sk;
+	struct sock *sk;
+
+	if (!bpf_sk)
+		return 1;
+
+	sk = (struct sock *)bpf_skc_to_tcp_sock(bpf_sk);
+	if (!sk)
+		return 1;
+
+	switch (skops->op) {
+	case BPF_SOCK_OPS_TCP_LISTEN_CB:
+		nr_listen += !bpf_test_sockopt(skops, sk);
+		break;
+	case BPF_SOCK_OPS_TCP_CONNECT_CB:
+		nr_connect += !bpf_test_sockopt(skops, sk);
+		break;
+	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+		nr_active += !bpf_test_sockopt(skops, sk);
+		break;
+	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+		nr_passive += !bpf_test_sockopt(skops, sk);
+		break;
+	}
+
+	return 1;
+}
+
+char _license[] SEC("license") = "GPL";