[PATCH v2 bpf-next 3/9] bpf: Test bpf_tcp_enter_cwr in test_verifier

[brakmo]

This test ensures the verifier has checked the arg1 of
BPF_FUNC_tcp_enter_cwr is of ARG_PTR_TO_TCP_SOCK type.

Signed-off-by: Martin KaFai Lau <ka...@fb.com>
Signed-off-by: Lawrence Brakmo <bra...@fb.com>
---
 tools/testing/selftests/bpf/verifier/sock.c | 33 +++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/tools/testing/selftests/bpf/verifier/sock.c 
b/tools/testing/selftests/bpf/verifier/sock.c
index 0ddfdf76aba5..b07a083eeb59 100644
--- a/tools/testing/selftests/bpf/verifier/sock.c
+++ b/tools/testing/selftests/bpf/verifier/sock.c
@@ -382,3 +382,36 @@
        .result = REJECT,
        .errstr = "type=tcp_sock expected=sock",
 },
+{
+       "bpf_tcp_enter_cwr(skb->sk)",
+       .insns = {
+       BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, 
sk)),
+       BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+       BPF_MOV64_IMM(BPF_REG_0, 0),
+       BPF_EXIT_INSN(),
+       BPF_EMIT_CALL(BPF_FUNC_tcp_enter_cwr),
+       BPF_MOV64_IMM(BPF_REG_0, 0),
+       BPF_EXIT_INSN(),
+       },
+       .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+       .result = REJECT,
+       .errstr = "type=sock_common expected=tcp_sock",
+},
+{
+       "bpf_tcp_enter_cwr(bpf_tcp_sock(skb->sk))",
+       .insns = {
+       BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, 
sk)),
+       BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2),
+       BPF_MOV64_IMM(BPF_REG_0, 0),
+       BPF_EXIT_INSN(),
+       BPF_EMIT_CALL(BPF_FUNC_tcp_sock),
+       BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+       BPF_EXIT_INSN(),
+       BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+       BPF_EMIT_CALL(BPF_FUNC_tcp_enter_cwr),
+       BPF_MOV64_IMM(BPF_REG_0, 0),
+       BPF_EXIT_INSN(),
+       },
+       .prog_type = BPF_PROG_TYPE_CGROUP_SKB,
+       .result = ACCEPT,
+},
-- 
2.17.1