selftest/bpf: Add test for bpf_getsockopt()

This patch removes the __bpf_getsockopt() which directly
reads the sk by using PTR_TO_BTF_ID.  Instead, the test now directly
uses the kernel bpf helper bpf_getsockopt() which supports all
the required optname now.

TCP_SAVE[D]_SYN and TCP_MAXSEG are not tested in a loop for all
the hooks and sock_ops's cb.  TCP_SAVE[D]_SYN only works
in passive connection.  TCP_MAXSEG only works when
it is setsockopt before the connection is established and
the getsockopt return value can only be tested after
the connection is established.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002937.2896904-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h
index 5ebc6da..adb087a 100644 (file)
--- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h
+++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h
@@ -38,6 +38,7 @@
 #define TCP_USER_TIMEOUT       18
 #define TCP_NOTSENT_LOWAT      25
 #define TCP_SAVE_SYN           27
+#define TCP_SAVED_SYN          28
 #define TCP_CA_NAME_MAX                16
 #define TCP_NAGLE_OFF          1
 

diff --git a/tools/testing/selftests/bpf/progs/setget_sockopt.c b/tools/testing/selftests/bpf/progs/setget_sockopt.c
index 79debf3..9523333 100644 (file)
--- a/tools/testing/selftests/bpf/progs/setget_sockopt.c
+++ b/tools/testing/selftests/bpf/progs/setget_sockopt.c
@@ -52,7 +52,6 @@ static const struct sockopt_test sol_socket_tests[] = {
 
 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, },
@@ -62,7 +61,6 @@ static const struct sockopt_test sol_tcp_tests[] = {
        { .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, },
 };
 
@@ -82,102 +80,6 @@ struct loop_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)
@@ -186,7 +88,7 @@ static int bpf_test_sockopt_flip(void *ctx, struct sock *sk,
 
        opt = t->opt;
 
-       if (__bpf_getsockopt(ctx, sk, level, opt, &old, sizeof(old)))
+       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)
@@ -195,7 +97,7 @@ static int bpf_test_sockopt_flip(void *ctx, struct sock *sk,
        new = !old;
        if (bpf_setsockopt(ctx, level, opt, &new, sizeof(new)))
                return 1;
-       if (__bpf_getsockopt(ctx, sk, level, opt, &tmp, sizeof(tmp)) ||
+       if (bpf_getsockopt(ctx, level, opt, &tmp, sizeof(tmp)) ||
            tmp != new)
                return 1;
 
@@ -218,13 +120,13 @@ static int bpf_test_sockopt_int(void *ctx, struct sock *sk,
        else
                expected = t->expected;
 
-       if (__bpf_getsockopt(ctx, sk, level, opt, &old, sizeof(old)) ||
+       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, sk, level, opt, &tmp, sizeof(tmp)) ||
+       if (bpf_getsockopt(ctx, level, opt, &tmp, sizeof(tmp)) ||
            tmp != expected)
                return 1;
 
@@ -410,6 +312,34 @@ static int binddev_test(void *ctx)
        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)
@@ -440,16 +370,22 @@ int skops_sockopt(struct bpf_sock_ops *skops)
 
        switch (skops->op) {
        case BPF_SOCK_OPS_TCP_LISTEN_CB:
-               nr_listen += !bpf_test_sockopt(skops, sk);
+               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);
+               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);
+               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);
+               nr_passive += !(bpf_test_sockopt(skops, sk) ||
+                               test_tcp_maxseg(skops, sk) ||
+                               test_tcp_saved_syn(skops, sk));
                break;
        }