wireaddr: helpers to convert to/from IPv4/v6 addresses.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

common/wireaddr.c

@@ -78,6 +78,50 @@ char *fmt_wireaddr(const tal_t *ctx, const struct wireaddr *a)
 }
 REGISTER_TYPE_TO_STRING(wireaddr, fmt_wireaddr);
 
+void wireaddr_from_ipv4(struct wireaddr *addr,
+			const struct in_addr *ip4,
+			const u16 port)
+{
+	addr->type = ADDR_TYPE_IPV4;
+	addr->addrlen = sizeof(*ip4);
+	addr->port = port;
+	memset(addr->addr, 0, sizeof(addr->addr));
+	memcpy(addr->addr, ip4, addr->addrlen);
+}
+
+void wireaddr_from_ipv6(struct wireaddr *addr,
+			const struct in6_addr *ip6,
+			const u16 port)
+{
+	addr->type = ADDR_TYPE_IPV6;
+	addr->addrlen = sizeof(*ip6);
+	addr->port = port;
+	memset(addr->addr, 0, sizeof(addr->addr));
+	memcpy(&addr->addr, ip6, addr->addrlen);
+}
+
+bool wireaddr_to_ipv4(const struct wireaddr *addr, struct sockaddr_in *s4)
+{
+	if (addr->type != ADDR_TYPE_IPV4)
+		return false;
+	s4->sin_family = AF_INET;
+	s4->sin_port = htons(addr->port);
+	assert(addr->addrlen == sizeof(s4->sin_addr));
+	memcpy(&s4->sin_addr, addr->addr, sizeof(s4->sin_addr));
+	return true;
+}
+
+bool wireaddr_to_ipv6(const struct wireaddr *addr, struct sockaddr_in6 *s6)
+{
+	if (addr->type != ADDR_TYPE_IPV6)
+		return false;
+	s6->sin6_family = AF_INET6;
+	s6->sin6_port = htons(addr->port);
+	assert(addr->addrlen == sizeof(s6->sin6_addr));
+	memcpy(&s6->sin6_addr, addr->addr, sizeof(s6->sin6_addr));
+	return true;
+}
+
 /* Valid forms:
  *
  * [anything]:<number>
@@ -148,18 +192,12 @@ bool wireaddr_from_hostname(struct wireaddr *addr, const char *hostname,
 	}
 	/* Use only the first found address */
 	if (addrinfo->ai_family == AF_INET) {
-		addr->type = ADDR_TYPE_IPV4;
-		addr->addrlen = 4;
-		addr->port = port;
 		sa4 = (struct sockaddr_in *) addrinfo->ai_addr;
-		memcpy(&addr->addr, &sa4->sin_addr, addr->addrlen);
+		wireaddr_from_ipv4(addr, &sa4->sin_addr, port);
 		res = true;
 	} else if (addrinfo->ai_family == AF_INET6) {
-		addr->type = ADDR_TYPE_IPV6;
-		addr->addrlen = 16;
-		addr->port = port;
 		sa6 = (struct sockaddr_in6 *) addrinfo->ai_addr;
-		memcpy(&addr->addr, &sa6->sin6_addr, addr->addrlen);
+		wireaddr_from_ipv6(addr, &sa6->sin6_addr, port);
 		res = true;
 	}
 
@@ -193,16 +231,10 @@ bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 defport,
 	memset(&addr->addr, 0, sizeof(addr->addr));
 
 	if (inet_pton(AF_INET, ip, &v4) == 1) {
-		addr->type = ADDR_TYPE_IPV4;
-		addr->addrlen = 4;
-		addr->port = port;
-		memcpy(&addr->addr, &v4, addr->addrlen);
+		wireaddr_from_ipv4(addr, &v4, port);
 		res = true;
 	} else if (inet_pton(AF_INET6, ip, &v6) == 1) {
-		addr->type = ADDR_TYPE_IPV6;
-		addr->addrlen = 16;
-		addr->port = port;
-		memcpy(&addr->addr, &v6, addr->addrlen);
+		wireaddr_from_ipv6(addr, &v6, port);
 		res = true;
 	}
 

common/wireaddr.h

@@ -6,6 +6,11 @@
 #include <stdbool.h>
 #include <stdlib.h>
 
+struct in6_addr;
+struct in_addr;
+struct sockaddr_in6;
+struct sockaddr_in;
+
 /* BOLT #7:
  *
  * The following `address descriptor` types are defined:
@@ -60,4 +65,13 @@ char *fmt_wireaddr(const tal_t *ctx, const struct wireaddr *a);
 bool wireaddr_from_hostname(struct wireaddr *addr, const char *hostname,
 			    const u16 port, const char **err_msg);
 
+void wireaddr_from_ipv4(struct wireaddr *addr,
+			const struct in_addr *ip4,
+			const u16 port);
+void wireaddr_from_ipv6(struct wireaddr *addr,
+			const struct in6_addr *ip6,
+			const u16 port);
+bool wireaddr_to_ipv4(const struct wireaddr *addr, struct sockaddr_in *s4);
+bool wireaddr_to_ipv6(const struct wireaddr *addr, struct sockaddr_in6 *s6);
+
 #endif /* LIGHTNING_COMMON_WIREADDR_H */

gossipd/gossip.c

@@ -1532,18 +1532,10 @@ static struct io_plan *connection_in(struct io_conn *conn, struct daemon *daemon
 
 	if (s.ss_family == AF_INET6) {
 		struct sockaddr_in6 *s6 = (void *)&s;
-		addr.type = ADDR_TYPE_IPV6;
-		addr.addrlen = sizeof(s6->sin6_addr);
-		BUILD_ASSERT(sizeof(s6->sin6_addr) <= sizeof(addr.addr));
-		memcpy(addr.addr, &s6->sin6_addr, addr.addrlen);
-		addr.port = ntohs(s6->sin6_port);
+		wireaddr_from_ipv6(&addr, &s6->sin6_addr, ntohs(s6->sin6_port));
 	} else if (s.ss_family == AF_INET) {
 		struct sockaddr_in *s4 = (void *)&s;
-		addr.type = ADDR_TYPE_IPV4;
-		addr.addrlen = sizeof(s4->sin_addr);
-		BUILD_ASSERT(sizeof(s4->sin_addr) <= sizeof(addr.addr));
-		memcpy(addr.addr, &s4->sin_addr, addr.addrlen);
-		addr.port = ntohs(s4->sin_port);
+		wireaddr_from_ipv4(&addr, &s4->sin_addr, ntohs(s4->sin_port));
 	} else {
 		status_broken("Unknown socket type %i for incoming conn",
 			      s.ss_family);
@@ -1568,13 +1560,7 @@ static void setup_listeners(struct daemon *daemon)
 
 		switch (daemon->wireaddrs[i].type) {
 		case ADDR_TYPE_IPV4:
-			addr.sin_family = AF_INET;
-			addr.sin_port = htons(daemon->wireaddrs[i].port);
-			assert(daemon->wireaddrs[i].addrlen
-			       == sizeof(addr.sin_addr));
-			memcpy(&addr.sin_addr,
-			       daemon->wireaddrs[i].addr,
-			       sizeof(addr.sin_addr));
+			wireaddr_to_ipv4(&daemon->wireaddrs[i], &addr);
 			/* We might fail if IPv6 bound to port first */
 			fd = make_listen_fd(AF_INET, &addr, sizeof(addr),
 					    !had_ipv6_wildcard);
@@ -1586,13 +1572,7 @@ static void setup_listeners(struct daemon *daemon)
 			}
 			continue;
 		case ADDR_TYPE_IPV6:
-			memset(&addr6, 0, sizeof(addr6));
-			addr6.sin6_family = AF_INET6;
-			addr6.sin6_port = htons(daemon->wireaddrs[i].port);
-			assert(daemon->wireaddrs[i].addrlen
-			       == sizeof(addr6.sin6_addr));
-			memcpy(&addr6.sin6_addr, daemon->wireaddrs[i].addr,
-			       sizeof(addr6.sin6_addr));
+			wireaddr_to_ipv6(&daemon->wireaddrs[i], &addr6);
 			if (memeqzero(&addr6.sin6_addr, sizeof(addr6.sin6_addr)))
 				had_ipv6_wildcard = true;
 			fd = make_listen_fd(AF_INET6, &addr6, sizeof(addr6),
@@ -1771,19 +1751,14 @@ static struct io_plan *conn_init(struct io_conn *conn, struct reaching *reach)
 
 	switch (reach->addr.type) {
 	case ADDR_TYPE_IPV4:
-		ai.ai_family = AF_INET;
-		sin.sin_family = AF_INET;
-		sin.sin_port = htons(reach->addr.port);
-		memcpy(&sin.sin_addr, reach->addr.addr, sizeof(sin.sin_addr));
+		wireaddr_to_ipv4(&reach->addr, &sin);
+		ai.ai_family = sin.sin_family;
 		ai.ai_addrlen = sizeof(sin);
 		ai.ai_addr = (struct sockaddr *)&sin;
 		break;
 	case ADDR_TYPE_IPV6:
-		ai.ai_family = AF_INET6;
-		memset(&sin6, 0, sizeof(sin6));
-		sin6.sin6_family = AF_INET6;
-		sin6.sin6_port = htons(reach->addr.port);
-		memcpy(&sin6.sin6_addr, reach->addr.addr, sizeof(sin6.sin6_addr));
+		wireaddr_to_ipv6(&reach->addr, &sin6);
+		ai.ai_family = sin6.sin6_family;
 		ai.ai_addrlen = sizeof(sin6);
 		ai.ai_addr = (struct sockaddr *)&sin6;
 		break;