swim: extract binary ip/port into a separate struct

At this moment there are two binary structures in the SWIM
protocol carrying an address: swim_member_passport and
swim_meta_header_bin - one address in each. This code duplication
was not formidable enough to stimulate creation of a separate
address structure.

But forthcoming indirect messages protocol extensions will add 2
new cases of encoding a binary address. It triggered this patch
to reduce code duplication.

Part of #3234

src/lib/swim/swim_proto.c

@@ -168,6 +168,31 @@ swim_check_inaddr_not_empty(const struct sockaddr_in *addr, const char *prefix,
 	return -1;
 }
 
+/**
+ * Create a binary address structure. It requires explicit IP and
+ * port keys specification since the keys depend on the component
+ * employing the address.
+ */
+static inline void
+swim_inaddr_bin_create(struct swim_inaddr_bin *bin, uint8_t ip_key,
+		       uint8_t port_key)
+{
+	assert(mp_sizeof_uint(ip_key) == 1 && mp_sizeof_uint(port_key) == 1);
+	bin->k_addr = ip_key;
+	bin->m_addr = 0xce;
+	bin->k_port = port_key;
+	bin->m_port = 0xcd;
+}
+
+/** Fill already created @a bin with a real inet address. */
+static inline void
+swim_inaddr_bin_fill(struct swim_inaddr_bin *bin,
+		     const struct sockaddr_in *addr)
+{
+	bin->v_addr = mp_bswap_u32(ntohl(addr->sin_addr.s_addr));
+	bin->v_port = mp_bswap_u16(ntohs(addr->sin_port));
+}
+
 void
 swim_member_def_create(struct swim_member_def *def)
 {
@@ -343,12 +368,12 @@ swim_anti_entropy_header_bin_create(struct swim_anti_entropy_header_bin *header,
 void
 swim_passport_bin_create(struct swim_passport_bin *passport)
 {
-	passport->m_header = 0x85;
+	int map_size = 3 + SWIM_INADDR_BIN_SIZE;
+	assert(mp_sizeof_map(map_size) == 1);
+	passport->m_header = 0x80 | map_size;
 	passport->k_status = SWIM_MEMBER_STATUS;
-	passport->k_addr = SWIM_MEMBER_ADDRESS;
-	passport->m_addr = 0xce;
-	passport->k_port = SWIM_MEMBER_PORT;
-	passport->m_port = 0xcd;
+	swim_inaddr_bin_create(&passport->addr, SWIM_MEMBER_ADDRESS,
+			       SWIM_MEMBER_PORT);
 	passport->k_uuid = SWIM_MEMBER_UUID;
 	passport->m_uuid = 0xc4;
 	passport->m_uuid_len = UUID_LEN;
@@ -363,8 +388,7 @@ swim_passport_bin_fill(struct swim_passport_bin *passport,
 		       enum swim_member_status status, uint64_t incarnation)
 {
 	passport->v_status = status;
-	passport->v_addr = mp_bswap_u32(ntohl(addr->sin_addr.s_addr));
-	passport->v_port = mp_bswap_u16(ntohs(addr->sin_port));
+	swim_inaddr_bin_fill(&passport->addr, addr);
 	memcpy(passport->v_uuid, uuid, UUID_LEN);
 	passport->v_incarnation = mp_bswap_u64(incarnation);
 }
@@ -382,16 +406,15 @@ void
 swim_meta_header_bin_create(struct swim_meta_header_bin *header,
 			    const struct sockaddr_in *src)
 {
-	header->m_header = 0x83;
+	int map_size = 1 + SWIM_INADDR_BIN_SIZE;
+	assert(mp_sizeof_map(map_size) == 1);
+	header->m_header = 0x80 | map_size;
 	header->k_version = SWIM_META_TARANTOOL_VERSION;
 	header->m_version = 0xce;
 	header->v_version = mp_bswap_u32(tarantool_version_id());
-	header->k_addr = SWIM_META_SRC_ADDRESS;
-	header->m_addr = 0xce;
-	header->v_addr = mp_bswap_u32(ntohl(src->sin_addr.s_addr));
-	header->k_port = SWIM_META_SRC_PORT;
-	header->m_port = 0xcd;
-	header->v_port = mp_bswap_u16(ntohs(src->sin_port));
+	swim_inaddr_bin_create(&header->src_addr, SWIM_META_SRC_ADDRESS,
+			       SWIM_META_SRC_PORT);
+	swim_inaddr_bin_fill(&header->src_addr, src);
 }
 
 int

src/lib/swim/swim_proto.h

@@ -232,6 +232,35 @@ swim_failure_detection_def_decode(struct swim_failure_detection_def *def,
 
 /** {{{                  Anti-entropy component                 */
 
+enum {
+	/**
+	 * Number of keys in the address binary structure.
+	 * Structures storing an address should use this size so
+	 * as to correctly encode MessagePack map header.
+	 */
+	SWIM_INADDR_BIN_SIZE = 2,
+};
+
+/**
+ * Binary inet address structure. It contains two fields at this
+ * moment - IP and port encoded as usual numbers. It means that
+ * after mp_decode_uint() it is necessary to use htonl/htons()
+ * functions to assign the values to struct sockaddr_in.
+ */
+struct PACKED swim_inaddr_bin {
+	/** mp_encode_uint(address key) */
+	uint8_t k_addr;
+	/** mp_encode_uint(ntohl(addr.sin_addr.s_addr)) */
+	uint8_t m_addr;
+	uint32_t v_addr;
+
+	/** mp_encode_uint(port key) */
+	uint8_t k_port;
+	/** mp_encode_uint(ntohs(addr.sin_port)) */
+	uint8_t m_port;
+	uint16_t v_port;
+};
+
 /**
  * Attributes of each record of a broadcasted member table. Just
  * the same as some of struct swim_member attributes.
@@ -279,17 +308,8 @@ struct PACKED swim_passport_bin {
 	/** mp_encode_uint(enum member_status) */
 	uint8_t v_status;
 
-	/** mp_encode_uint(SWIM_MEMBER_ADDRESS) */
-	uint8_t k_addr;
-	/** mp_encode_uint(addr.sin_addr.s_addr) */
-	uint8_t m_addr;
-	uint32_t v_addr;
-
-	/** mp_encode_uint(SWIM_MEMBER_PORT) */
-	uint8_t k_port;
-	/** mp_encode_uint(addr.sin_port) */
-	uint8_t m_port;
-	uint16_t v_port;
+	/** SWIM_MEMBER_ADDRESS and SWIM_MEMBER_PORT. */
+	struct swim_inaddr_bin addr;
 
 	/** mp_encode_uint(SWIM_MEMBER_UUID) */
 	uint8_t k_uuid;
@@ -386,17 +406,8 @@ struct PACKED swim_meta_header_bin {
 	uint8_t m_version;
 	uint32_t v_version;
 
-	/** mp_encode_uint(SWIM_META_SRC_ADDRESS) */
-	uint8_t k_addr;
-	/** mp_encode_uint(addr.sin_addr.s_addr) */
-	uint8_t m_addr;
-	uint32_t v_addr;
-
-	/** mp_encode_uint(SWIM_META_SRC_PORT) */
-	uint8_t k_port;
-	/** mp_encode_uint(addr.sin_port) */
-	uint8_t m_port;
-	uint16_t v_port;
+	/** SWIM_META_SRC_ADDRESS and SWIM_META_SRC_PORT. */
+	struct swim_inaddr_bin src_addr;
 };
 
 /** Initialize meta section. */