selftests/bpf: Test allowed maps for bpf_sk_select_reuseport

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>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200430104738.494180-1-jakub@cloudflare.com

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)

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,
+},