From 7790a617d8688188fb60ded3b64ffefdde42c83d Mon Sep 17 00:00:00 2001
From: Sam Hocevar <sam@hocevar.net>
Date: Sun, 14 Feb 2021 09:48:12 +0100
Subject: [PATCH] Remove all legacy IPv4 code.

---
 src/net.c    | 21 +++++++++++++++++++++
 src/net.h    |  1 +
 src/rinetd.c | 21 ++++++++++++---------
 src/types.h  |  4 ++--
 4 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/src/net.c b/src/net.c
index 045f23c..dea9c6d 100644
--- a/src/net.c
+++ b/src/net.c
@@ -36,6 +36,27 @@ int getSocketType(int protocol) {
 	return protocol == IPPROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
 }
 
+int sameSocketAddress(struct sockaddr_storage *a, struct sockaddr_storage *b) {
+	if (a->ss_family != b->ss_family)
+		return 0;
+
+	switch (a->ss_family) {
+		case AF_INET: {
+			struct sockaddr_in *a4 = (struct sockaddr_in *)a;
+			struct sockaddr_in *b4 = (struct sockaddr_in *)b;
+			return a4->sin_port == b4->sin_port
+				&& a4->sin_addr.s_addr == b4->sin_addr.s_addr;
+		}
+		case AF_INET6: {
+			struct sockaddr_in6 *a6 = (struct sockaddr_in6 *)a;
+			struct sockaddr_in6 *b6 = (struct sockaddr_in6 *)b;
+			return a6->sin6_port == b6->sin6_port
+				&& a6->sin6_addr.s6_addr == b6->sin6_addr.s6_addr;
+		}
+	}
+	return 0;
+}
+
 uint16_t getPort(struct addrinfo* ai) {
 	switch (ai->ai_family) {
 		case AF_INET:
diff --git a/src/net.h b/src/net.h
index c41c4d0..a043093 100644
--- a/src/net.h
+++ b/src/net.h
@@ -82,4 +82,5 @@ static inline int GetLastError(void) {
 
 void setSocketDefaults(SOCKET fd);
 int getSocketType(int protocol);
+int sameSocketAddress(struct sockaddr_storage *a, struct sockaddr_storage *b);
 uint16_t getPort(struct addrinfo* ai);
diff --git a/src/rinetd.c b/src/rinetd.c
index da5f6f7..08b0672 100644
--- a/src/rinetd.c
+++ b/src/rinetd.c
@@ -697,13 +697,10 @@ static void handleAccept(ServerInfo const *srv)
 
 		udpBytes = (int)ret;
 
+		/* Look for an existing connection with the same remote host and port. */
 		for (int i = 0; i < coTotal; ++i) {
 			ConnectionInfo *cnx = &coInfo[i];
-			struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr;
-			if (cnx->remote.fd == nfd
-				&& cnx->remoteAddress.sin_family == addr_in->sin_family
-				&& cnx->remoteAddress.sin_port == addr_in->sin_port
-				&& cnx->remoteAddress.sin_addr.s_addr == addr_in->sin_addr.s_addr) {
+			if (cnx->remote.fd == nfd && sameSocketAddress(&cnx->remoteAddress, &addr)) {
 				cnx->remoteTimeout = time(NULL) + srv->serverTimeout;
 				handleUdpRead(cnx, globalUdpBuffer, udpBytes);
 				return;
@@ -717,15 +714,17 @@ static void handleAccept(ServerInfo const *srv)
 	}
 
 	cnx->local.fd = INVALID_SOCKET;
+	cnx->local.family = srv->toAddrInfo->ai_family;
 	cnx->local.protocol = srv->toAddrInfo->ai_protocol;
 	cnx->local.recvPos = cnx->local.sentPos = 0;
 	cnx->local.totalBytesIn = cnx->local.totalBytesOut = 0;
 
 	cnx->remote.fd = nfd;
+	cnx->remote.family = srv->fromAddrInfo->ai_family;
 	cnx->remote.protocol = srv->fromAddrInfo->ai_protocol;
 	cnx->remote.recvPos = cnx->remote.sentPos = 0;
 	cnx->remote.totalBytesIn = cnx->remote.totalBytesOut = 0;
-	cnx->remoteAddress = *(struct sockaddr_in *)&addr;
+	cnx->remoteAddress = addr;
 	if (srv->fromAddrInfo->ai_protocol == IPPROTO_UDP)
 		cnx->remoteTimeout = time(NULL) + srv->serverTimeout;
 
@@ -815,7 +814,10 @@ static void handleAccept(ServerInfo const *srv)
 static int checkConnectionAllowed(ConnectionInfo const *cnx)
 {
 	ServerInfo const *srv = cnx->server;
-	char const *addressText = inet_ntoa(cnx->remoteAddress.sin_addr);
+
+	char addressText[NI_MAXHOST];
+	getnameinfo((struct sockaddr *)&cnx->remoteAddress, sizeof(cnx->remoteAddress),
+		addressText, sizeof(addressText), NULL, 0, NI_NUMERICHOST);
 
 	/* 1. Check global allow rules. If there are no
 		global allow rules, it's presumed OK at
@@ -938,6 +940,7 @@ static void logEvent(ConnectionInfo const *cnx, ServerInfo const *srv, int resul
 		thanks folks */
 	int timz;
 	char tstr[1024];
+	char addressText[NI_MAXHOST] = { '?' };
 	struct tm *t = get_gmtoff(&timz);
 	char sign = (timz < 0 ? '-' : '+');
 	if (timz < 0) {
@@ -945,10 +948,10 @@ static void logEvent(ConnectionInfo const *cnx, ServerInfo const *srv, int resul
 	}
 	strftime(tstr, sizeof(tstr), "%d/%b/%Y:%H:%M:%S ", t);
 
-	char const *addressText = "?";
 	int64_t bytesOut = 0, bytesIn = 0;
 	if (cnx != NULL) {
-		addressText = inet_ntoa(cnx->remoteAddress.sin_addr);
+		getnameinfo((struct sockaddr *)&cnx->remoteAddress, sizeof(cnx->remoteAddress),
+			addressText, sizeof(addressText), NULL, 0, NI_NUMERICHOST);
 		bytesOut = cnx->remote.totalBytesOut;
 		bytesIn = cnx->remote.totalBytesIn;
 	}
diff --git a/src/types.h b/src/types.h
index 9261f84..44d9fcb 100644
--- a/src/types.h
+++ b/src/types.h
@@ -46,7 +46,7 @@ typedef struct _socket Socket;
 struct _socket
 {
 	SOCKET fd;
-	int protocol;
+	int family, protocol;
 	/* recv: received on this socket
 		sent: sent through this socket from the other buffer */
 	int recvPos, sentPos;
@@ -58,7 +58,7 @@ typedef struct _connection_info ConnectionInfo;
 struct _connection_info
 {
 	Socket remote, local;
-	struct sockaddr_in remoteAddress;
+	struct sockaddr_storage remoteAddress;
 	time_t remoteTimeout;
 	int coClosing;
 	int coLog;