selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP

Adding selftests for new added functionality to set TCP_WINDOW_CLAMP
from bpf setsockopt.

Signed-off-by: Prankur gupta <prankgup@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201202213152.435886-3-prankgup@fb.com

diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index 2915664..6a90531 100644 (file)
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -56,6 +56,7 @@ struct tcp_sock {
        __u32   rcv_nxt;
        __u32   snd_nxt;
        __u32   snd_una;
+       __u32   window_clamp;
        __u8    ecn_flags;
        __u32   delivered;
        __u32   delivered_ce;

diff --git a/tools/testing/selftests/bpf/prog_tests/tcpbpf_user.c b/tools/testing/selftests/bpf/prog_tests/tcpbpf_user.c
index ab52814..87923d2 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/tcpbpf_user.c
+++ b/tools/testing/selftests/bpf/prog_tests/tcpbpf_user.c
@@ -42,6 +42,10 @@ static void verify_result(struct tcpbpf_globals *result)
 
        /* check getsockopt for SAVED_SYN */
        ASSERT_EQ(result->tcp_saved_syn, 1, "tcp_saved_syn");
+
+       /* check getsockopt for window_clamp */
+       ASSERT_EQ(result->window_clamp_client, 9216, "window_clamp_client");
+       ASSERT_EQ(result->window_clamp_server, 9216, "window_clamp_server");
 }
 
 static void run_test(struct tcpbpf_globals *result)

diff --git a/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c b/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c
index e85e49d..94f50f7 100644 (file)
--- a/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c
+++ b/tools/testing/selftests/bpf/progs/test_tcpbpf_kern.c
@@ -12,17 +12,41 @@
 #include <linux/tcp.h>
 #include <bpf/bpf_helpers.h>
 #include <bpf/bpf_endian.h>
+#include "bpf_tcp_helpers.h"
 #include "test_tcpbpf.h"
 
 struct tcpbpf_globals global = {};
 int _version SEC("version") = 1;
 
+/**
+ * SOL_TCP is defined in <netinet/tcp.h> while
+ * TCP_SAVED_SYN is defined in already included <linux/tcp.h>
+ */
+#ifndef SOL_TCP
+#define SOL_TCP 6
+#endif
+
+static __always_inline int get_tp_window_clamp(struct bpf_sock_ops *skops)
+{
+       struct bpf_sock *sk;
+       struct tcp_sock *tp;
+
+       sk = skops->sk;
+       if (!sk)
+               return -1;
+       tp = bpf_skc_to_tcp_sock(sk);
+       if (!tp)
+               return -1;
+       return tp->window_clamp;
+}
+
 SEC("sockops")
 int bpf_testcb(struct bpf_sock_ops *skops)
 {
        char header[sizeof(struct ipv6hdr) + sizeof(struct tcphdr)];
        struct bpf_sock_ops *reuse = skops;
        struct tcphdr *thdr;
+       int window_clamp = 9216;
        int good_call_rv = 0;
        int bad_call_rv = 0;
        int save_syn = 1;
@@ -75,6 +99,11 @@ int bpf_testcb(struct bpf_sock_ops *skops)
        global.event_map |= (1 << op);
 
        switch (op) {
+       case BPF_SOCK_OPS_TCP_CONNECT_CB:
+               rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP,
+                                   &window_clamp, sizeof(window_clamp));
+               global.window_clamp_client = get_tp_window_clamp(skops);
+               break;
        case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
                /* Test failure to set largest cb flag (assumes not defined) */
                global.bad_cb_test_rv = bpf_sock_ops_cb_flags_set(skops, 0x80);
@@ -100,6 +129,10 @@ int bpf_testcb(struct bpf_sock_ops *skops)
                                global.tcp_saved_syn = v;
                        }
                }
+               rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP,
+                                   &window_clamp, sizeof(window_clamp));
+
+               global.window_clamp_server = get_tp_window_clamp(skops);
                break;
        case BPF_SOCK_OPS_RTO_CB:
                break;

diff --git a/tools/testing/selftests/bpf/test_tcpbpf.h b/tools/testing/selftests/bpf/test_tcpbpf.h
index 0ed3352..9dd9b55 100644 (file)
--- a/tools/testing/selftests/bpf/test_tcpbpf.h
+++ b/tools/testing/selftests/bpf/test_tcpbpf.h
@@ -16,5 +16,7 @@ struct tcpbpf_globals {
        __u32 num_close_events;
        __u32 tcp_save_syn;
        __u32 tcp_saved_syn;
+       __u32 window_clamp_client;
+       __u32 window_clamp_server;
 };
 #endif