bpf:selftests: add bpf_mptcp_sock() verifier tests

This patch adds verifier side tests for the new bpf_mptcp_sock() helper. Currently, there is no easy way to test the token field since we cannot get back the mptcp_sock, this could be a future amelioration. Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Nicolas Rybowski <nicolas.rybowski@tessares.net>
multipath-tcp · Jan 28, 2021 · cae4ced · cae4ced
1 parent 7bd6ee3
commit cae4ced
Showing 1 changed file with 63 additions and 0 deletions.
diff --git a/tools/testing/selftests/bpf/verifier/sock.c b/tools/testing/selftests/bpf/verifier/sock.c
@@ -656,3 +656,66 @@
 	.result_unpriv = REJECT,
 	.errstr_unpriv = "unknown func",
 },
+{
+	"bpf_mptcp_sock(skops->sk): no !skops->sk check",
+	.insns = {
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct bpf_sock_ops, sk)),
+	BPF_EMIT_CALL(BPF_FUNC_mptcp_sock),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SOCK_OPS,
+	.result = REJECT,
+	.errstr = "type=sock_or_null expected=sock_common",
+},
+{
+	"bpf_mptcp_sock(skops->sk): no NULL check on ret",
+	.insns = {
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct bpf_sock_ops, 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_mptcp_sock),
+	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_mptcp_sock, token)),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SOCK_OPS,
+	.result = REJECT,
+	.errstr = "invalid mem access 'mptcp_sock_or_null'",
+},
+{
+	"bpf_mptcp_sock(skops->sk): msk->token",
+	.insns = {
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct bpf_sock_ops, 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_mptcp_sock),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_mptcp_sock, token)),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SOCK_OPS,
+	.result = ACCEPT,
+},
+{
+	"bpf_mptcp_sock(skops->sk): msk->token cannot be modified",
+	.insns = {
+	BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct bpf_sock_ops, 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_mptcp_sock),
+	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+	BPF_EXIT_INSN(),
+	BPF_ST_MEM(BPF_W, BPF_REG_0, offsetof(struct bpf_mptcp_sock, token), 0x2a),
+	BPF_MOV64_IMM(BPF_REG_0, 0),
+	BPF_EXIT_INSN(),
+	},
+	.prog_type = BPF_PROG_TYPE_SOCK_OPS,
+	.result = REJECT,
+	.errstr = "cannot write into mptcp_sock",
+},