root/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>
#include "bpf_misc.h"

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;
int nr_fin_wait1;

struct sockopt_test {
        int opt;
        int new;
        int restore;
        int expected;
        int tcp_expected;
        unsigned int flip:1;
};

static const char not_exist_cc[] = "not_exist";
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_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_BPF_SOCK_OPS_CB_FLAGS, .new = BPF_SOCK_OPS_ALL_CB_FLAGS,
          .expected = BPF_SOCK_OPS_ALL_CB_FLAGS, },
        { .opt = TCP_BPF_DELACK_MAX, .new = 30000, .expected = 30000, },
        { .opt = TCP_BPF_RTO_MIN, .new = 30000, .expected = 30000, },
        { .opt = TCP_RTO_MAX_MS, .new = 2000, .expected = 2000, },
        { .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 bool sk_is_tcp(struct sock *sk)
{
        return (sk->__sk_common.skc_family == AF_INET ||
                sk->__sk_common.skc_family == AF_INET6) &&
                sk->sk_type == SOCK_STREAM &&
                sk->sk_protocol == IPPROTO_TCP;
}

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 (opt == SO_TXREHASH && !sk_is_tcp(sk))
                return 0;

        if (bpf_getsockopt(ctx, 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, 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, level, opt, &old, sizeof(old)) ||
            old == new)
                return 1;

        if (bpf_setsockopt(ctx, level, opt, &new, sizeof(new)))
                return 1;
        if (bpf_getsockopt(ctx, 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;
                int new_cc_len;

                if (!bpf_setsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION,
                                    (void *)not_exist_cc, sizeof(not_exist_cc)))
                        return 1;
                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;
                        new_cc_len = sizeof(reno_cc);
                } else {
                        new_cc = cubic_cc;
                        new_cc_len = sizeof(cubic_cc);
                }
                if (bpf_setsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, (void *)new_cc,
                                   new_cc_len))
                        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;
}

static int test_tcp_maxseg(void *ctx, struct sock *sk)
{
        int val = 1314, tmp;

        if (sk->sk_state != TCP_ESTABLISHED)
                return bpf_setsockopt(ctx, IPPROTO_TCP, TCP_MAXSEG,
                                      &val, sizeof(val));

        if (bpf_getsockopt(ctx, IPPROTO_TCP, TCP_MAXSEG, &tmp, sizeof(tmp)) ||
            tmp > val)
                return -1;

        return 0;
}

static int test_tcp_saved_syn(void *ctx, struct sock *sk)
{
        __u8 saved_syn[20];
        int one = 1;

        if (sk->sk_state == TCP_LISTEN)
                return bpf_setsockopt(ctx, IPPROTO_TCP, TCP_SAVE_SYN,
                                      &one, sizeof(one));

        return bpf_getsockopt(ctx, IPPROTO_TCP, TCP_SAVED_SYN,
                              saved_syn, sizeof(saved_syn));
}

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("cgroup/getsockopt")
int _getsockopt(struct bpf_sockopt *ctx)
{
        struct bpf_sock *sk = ctx->sk;
        int *optval = ctx->optval;
        struct tcp_sock *tp;

        if (!sk || ctx->level != SOL_TCP || ctx->optname != TCP_BPF_SOCK_OPS_CB_FLAGS)
                return 1;

        tp = bpf_core_cast(sk, struct tcp_sock);
        if (ctx->optval + sizeof(int) <= ctx->optval_end) {
                *optval = tp->bpf_sock_ops_cb_flags;
                ctx->retval = 0;
        }
        return 1;
}

int v4mapped_v6_ip_tos_enable;
int v4mapped_v6_ip_tos_ret;
int v4mapped_v6_ip_tos_cnt;
int v4mapped_v6_ip_tos_val;

static void test_v4mapped_v6_ip_tos(struct bpf_sock_ops *skops)
{
        int tos = v4mapped_v6_ip_tos_val;

        if (!v4mapped_v6_ip_tos_enable || skops->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
                return;
        if (skops->family != AF_INET6)
                return;

        v4mapped_v6_ip_tos_cnt++;
        v4mapped_v6_ip_tos_ret = bpf_setsockopt(skops, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
}

SEC("sockops")
int skops_sockopt(struct bpf_sock_ops *skops)
{
        struct bpf_sock *bpf_sk = skops->sk;
        struct sock *sk;
        int flags;

        if (!bpf_sk)
                return 1;

        sk = (struct sock *)bpf_skc_to_tcp_sock(bpf_sk);
        if (!sk)
                return 1;

        if (v4mapped_v6_ip_tos_enable) {
                test_v4mapped_v6_ip_tos(skops);
                return 1;
        }

        switch (skops->op) {
        case BPF_SOCK_OPS_TCP_LISTEN_CB:
                nr_listen += !(bpf_test_sockopt(skops, sk) ||
                               test_tcp_maxseg(skops, sk) ||
                               test_tcp_saved_syn(skops, sk));
                break;
        case BPF_SOCK_OPS_TCP_CONNECT_CB:
                nr_connect += !(bpf_test_sockopt(skops, sk) ||
                                test_tcp_maxseg(skops, sk));
                break;
        case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
                nr_active += !(bpf_test_sockopt(skops, sk) ||
                               test_tcp_maxseg(skops, sk));
                break;
        case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
                nr_passive += !(bpf_test_sockopt(skops, sk) ||
                                test_tcp_maxseg(skops, sk) ||
                                test_tcp_saved_syn(skops, sk));
                flags = skops->bpf_sock_ops_cb_flags | BPF_SOCK_OPS_STATE_CB_FLAG;
                bpf_setsockopt(skops, SOL_TCP, TCP_BPF_SOCK_OPS_CB_FLAGS, &flags, sizeof(flags));
                break;
        case BPF_SOCK_OPS_STATE_CB:
                if (skops->args[1] == BPF_TCP_CLOSE_WAIT)
                        nr_fin_wait1 += !bpf_test_sockopt(skops, sk);
                break;
        }

        return 1;
}

char _license[] SEC("license") = "GPL";