selftests/bpf: convert socket_cookie test to sk storage

This lets us test that both BPF_PROG_TYPE_CGROUP_SOCK_ADDR and
BPF_PROG_TYPE_SOCK_OPS can access underlying bpf_sock.

Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/testing/selftests/bpf/progs/socket_cookie_prog.c

@@ -7,25 +7,35 @@
 #include "bpf_helpers.h"
 #include "bpf_endian.h"
 
+struct socket_cookie {
+	__u64 cookie_key;
+	__u32 cookie_value;
+};
+
 struct bpf_map_def SEC("maps") socket_cookies = {
-	.type = BPF_MAP_TYPE_HASH,
-	.key_size = sizeof(__u64),
-	.value_size = sizeof(__u32),
-	.max_entries = 1 << 8,
+	.type = BPF_MAP_TYPE_SK_STORAGE,
+	.key_size = sizeof(int),
+	.value_size = sizeof(struct socket_cookie),
+	.map_flags = BPF_F_NO_PREALLOC,
 };
 
+BPF_ANNOTATE_KV_PAIR(socket_cookies, int, struct socket_cookie);
+
 SEC("cgroup/connect6")
 int set_cookie(struct bpf_sock_addr *ctx)
 {
-	__u32 cookie_value = 0xFF;
-	__u64 cookie_key;
+	struct socket_cookie *p;
 
 	if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6)
 		return 1;
 
-	cookie_key = bpf_get_socket_cookie(ctx);
-	if (bpf_map_update_elem(&socket_cookies, &cookie_key, &cookie_value, 0))
-		return 0;
+	p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0,
+			       BPF_SK_STORAGE_GET_F_CREATE);
+	if (!p)
+		return 1;
+
+	p->cookie_value = 0xFF;
+	p->cookie_key = bpf_get_socket_cookie(ctx);
 
 	return 1;
 }
@@ -33,9 +43,8 @@ int set_cookie(struct bpf_sock_addr *ctx)
 SEC("sockops")
 int update_cookie(struct bpf_sock_ops *ctx)
 {
-	__u32 new_cookie_value;
-	__u32 *cookie_value;
-	__u64 cookie_key;
+	struct bpf_sock *sk;
+	struct socket_cookie *p;
 
 	if (ctx->family != AF_INET6)
 		return 1;
@@ -43,14 +52,17 @@ int update_cookie(struct bpf_sock_ops *ctx)
 	if (ctx->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
 		return 1;
 
-	cookie_key = bpf_get_socket_cookie(ctx);
+	if (!ctx->sk)
+		return 1;
+
+	p = bpf_sk_storage_get(&socket_cookies, ctx->sk, 0, 0);
+	if (!p)
+		return 1;
 
-	cookie_value = bpf_map_lookup_elem(&socket_cookies, &cookie_key);
-	if (!cookie_value)
+	if (p->cookie_key != bpf_get_socket_cookie(ctx))
 		return 1;
 
-	new_cookie_value = (ctx->local_port << 8) | *cookie_value;
-	bpf_map_update_elem(&socket_cookies, &cookie_key, &new_cookie_value, 0);
+	p->cookie_value = (ctx->local_port << 8) | p->cookie_value;
 
 	return 1;
 }

tools/testing/selftests/bpf/test_socket_cookie.c

@@ -18,6 +18,11 @@
 #define CG_PATH			"/foo"
 #define SOCKET_COOKIE_PROG	"./socket_cookie_prog.o"
 
+struct socket_cookie {
+	__u64 cookie_key;
+	__u32 cookie_value;
+};
+
 static int start_server(void)
 {
 	struct sockaddr_in6 addr;
@@ -89,8 +94,7 @@ static int validate_map(struct bpf_map *map, int client_fd)
 	__u32 cookie_expected_value;
 	struct sockaddr_in6 addr;
 	socklen_t len = sizeof(addr);
-	__u32 cookie_value;
-	__u64 cookie_key;
+	struct socket_cookie val;
 	int err = 0;
 	int map_fd;
 
@@ -101,17 +105,7 @@ static int validate_map(struct bpf_map *map, int client_fd)
 
 	map_fd = bpf_map__fd(map);
 
-	err = bpf_map_get_next_key(map_fd, NULL, &cookie_key);
-	if (err) {
-		log_err("Can't get cookie key from map");
-		goto out;
-	}
-
-	err = bpf_map_lookup_elem(map_fd, &cookie_key, &cookie_value);
-	if (err) {
-		log_err("Can't get cookie value from map");
-		goto out;
-	}
+	err = bpf_map_lookup_elem(map_fd, &client_fd, &val);
 
 	err = getsockname(client_fd, (struct sockaddr *)&addr, &len);
 	if (err) {
@@ -120,8 +114,8 @@ static int validate_map(struct bpf_map *map, int client_fd)
 	}
 
 	cookie_expected_value = (ntohs(addr.sin6_port) << 8) | 0xFF;
-	if (cookie_value != cookie_expected_value) {
-		log_err("Unexpected value in map: %x != %x", cookie_value,
+	if (val.cookie_value != cookie_expected_value) {
+		log_err("Unexpected value in map: %x != %x", val.cookie_value,
 			cookie_expected_value);
 		goto err;
 	}