[PATCH bpf-next] selftests/bpf: Test allowed maps for bpf_sk_select_reuseport

[PATCH bpf-next] selftests/bpf: Test allowed maps for bpf_sk_select_reuseport

[Jakub Sitnicki]

Check that verifier allows passing a map of type:

 BPF_MAP_TYPE_REUSEPORT_SOCKARRARY, or
 BPF_MAP_TYPE_SOCKMAP, or
 BPF_MAP_TYPE_SOCKHASH

... to bpf_sk_select_reuseport helper.

Suggested-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---
 tools/testing/selftests/bpf/test_verifier.c | 12 +++++-
 tools/testing/selftests/bpf/verifier/sock.c | 45 +++++++++++++++++++++
 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index ad6939c67c5e..21a1ce219c1c 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -50,7 +50,7 @@
 #define MAX_INSNS	BPF_MAXINSNS
 #define MAX_TEST_INSNS	1000000
 #define MAX_FIXUPS	8
-#define MAX_NR_MAPS	19
+#define MAX_NR_MAPS	20
 #define MAX_TEST_RUNS	8
 #define POINTER_VALUE	0xcafe4all
 #define TEST_DATA_LEN	64
@@ -86,6 +86,7 @@ struct bpf_test {
 	int fixup_map_array_small[MAX_FIXUPS];
 	int fixup_sk_storage_map[MAX_FIXUPS];
 	int fixup_map_event_output[MAX_FIXUPS];
+	int fixup_map_reuseport_array[MAX_FIXUPS];
 	const char *errstr;
 	const char *errstr_unpriv;
 	uint32_t insn_processed;
@@ -637,6 +638,7 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
 	int *fixup_map_array_small = test->fixup_map_array_small;
 	int *fixup_sk_storage_map = test->fixup_sk_storage_map;
 	int *fixup_map_event_output = test->fixup_map_event_output;
+	int *fixup_map_reuseport_array = test->fixup_map_reuseport_array;
 
 	if (test->fill_helper) {
 		test->fill_insns = calloc(MAX_TEST_INSNS, sizeof(struct bpf_insn));
@@ -806,6 +808,14 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type,
 			fixup_map_event_output++;
 		} while (*fixup_map_event_output);
 	}
+	if (*fixup_map_reuseport_array) {
+		map_fds[19] = __create_map(BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
+					   sizeof(u32), sizeof(u64), 1, 0);
+		do {
+			prog[*fixup_map_reuseport_array].imm = map_fds[19];
+			fixup_map_reuseport_array++;
+		} while (*fixup_map_reuseport_array);
+	}
 }
 
 static int set_admin(bool admin)
diff --git a/tools/testing/selftests/bpf/verifier/sock.c b/tools/testing/selftests/bpf/verifier/sock.c
index f87ad69dbc62..0bc51ad9e0fb 100644
--- a/tools/testing/selftests/bpf/verifier/sock.c
+++ b/tools/testing/selftests/bpf/verifier/sock.c
@@ -586,3 +586,48 @@
 	.prog_type = BPF_PROG_TYPE_SK_SKB,
 	.result = ACCEPT,
 },
+{
+	"bpf_sk_select_reuseport(ctx, reuseport_array, &key, flags)",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_4, 0),
+	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -4),
+	BPF_LD_MAP_FD(BPF_REG_2, 0),
+	BPF_EMIT_CALL(BPF_FUNC_sk_select_reuseport),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_reuseport_array = { 4 },
+	.prog_type = BPF_PROG_TYPE_SK_REUSEPORT,
+	.result = ACCEPT,
+},
+{
+	"bpf_sk_select_reuseport(ctx, sockmap, &key, flags)",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_4, 0),
+	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -4),
+	BPF_LD_MAP_FD(BPF_REG_2, 0),
+	BPF_EMIT_CALL(BPF_FUNC_sk_select_reuseport),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_sockmap = { 4 },
+	.prog_type = BPF_PROG_TYPE_SK_REUSEPORT,
+	.result = ACCEPT,
+},
+{
+	"bpf_sk_select_reuseport(ctx, sockhash, &key, flags)",
+	.insns = {
+	BPF_MOV64_IMM(BPF_REG_4, 0),
+	BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 0),
+	BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
+	BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -4),
+	BPF_LD_MAP_FD(BPF_REG_2, 0),
+	BPF_EMIT_CALL(BPF_FUNC_sk_select_reuseport),
+	BPF_EXIT_INSN(),
+	},
+	.fixup_map_sockmap = { 4 },
+	.prog_type = BPF_PROG_TYPE_SK_REUSEPORT,
+	.result = ACCEPT,
+},
-- 
2.25.3

Re: [PATCH bpf-next] selftests/bpf: Test allowed maps for bpf_sk_select_reuseport

[Daniel Borkmann]

On 4/30/20 12:47 PM, Jakub Sitnicki wrote:
> Check that verifier allows passing a map of type:
> 
>   BPF_MAP_TYPE_REUSEPORT_SOCKARRARY, or
>   BPF_MAP_TYPE_SOCKMAP, or
>   BPF_MAP_TYPE_SOCKHASH
> 
> ... to bpf_sk_select_reuseport helper.
> 
> Suggested-by: John Fastabend <john.fastabend@gmail.com>
> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>

Looks good, applied!