Merge 983df6f7ae into c5ba790d13

man/socks.8

@@ -42,6 +42,16 @@ of IP-IP NAT (will not work for PAT)
 Internal address. IP address proxy accepts connections to.
 By default connection to any interface is accepted. It\'s usually unsafe.
 .TP
+.B -k
+External address given by
+.B -e
+is ignored and the internal address or generally the address client conected to is used instead.
+This allows to utilize AnyIP Linux feature when
+.B -i0.0.0.0
+or in case of IPv6
+.B -i::
+is set. Not available for Windows platform.
+.TP
 .B -p
 Port. Port proxy listens for incoming connections. Default is 1080.
 .TP

src/common.c

@@ -522,16 +522,48 @@ int doconnect(struct clientparam * param){
 	if(!*SAPORT(&param->sinsr))*SAPORT(&param->sinsr) = *SAPORT(&param->req);
 	if ((param->remsock=param->srv->so._socket(param->sostate, SASOCK(&param->sinsr), SOCK_STREAM, IPPROTO_TCP)) == INVALID_SOCKET) {return (11);}
 	if(SAISNULL(&param->sinsl)){
+		if (param->srv->keepip) {
 #ifndef NOIPV6
-		if(*SAFAMILY(&param->sinsr) == AF_INET6) param->sinsl = param->srv->extsa6;
-		else
+			struct sockaddr_in6 local_addr;
+			socklen_t local_addr_len = sizeof(local_addr);
+			getsockname(param->clisock, (struct sockaddr *)&local_addr, &local_addr_len);
+
+			if(*SAFAMILY(&local_addr) == AF_INET6) {
+				if (IN6_IS_ADDR_V4MAPPED(&local_addr.sin6_addr)) {
+					struct sockaddr_in6 local_addr2;
+					memset(&local_addr2, 0, sizeof(local_addr2));
+					local_addr2.sin6_family = AF_INET;
+					local_addr2.sin6_port = local_addr.sin6_port;
+					param->sinsl = local_addr2;
+				} else {
+					param->sinsl = local_addr;
+				}
+			} else {
+				param->sinsl = local_addr;
+			}
+#else
+			struct sockaddr_in local_addr;
+			socklen_t local_addr_len = sizeof(local_addr);
+			getsockname(new_sock, (struct sockaddr *)&local_addr, &local_addr_len);
+				param->sinsl = local_addr;
 #endif
-			param->sinsl = param->srv->extsa;
+		} else {
+#ifndef NOIPV6
+			if(*SAFAMILY(&param->sinsr) == AF_INET6) param->sinsl = param->srv->extsa6;
+			else
+#endif
+				param->sinsl = param->srv->extsa;
+		}
 	}
 	*SAPORT(&param->sinsl) = 0;
 	setopts(param->remsock, param->srv->srvsockopts);
 
 	param->srv->so._setsockopt(param->sostate, param->remsock, SOL_SOCKET, SO_LINGER, (char *)&lg, sizeof(lg));
+
+	if (param->srv->keepip) {
+		int opt = 1;
+		param->srv->so._setsockopt(param->sostate, param->remsock, SOL_IP, IP_FREEBIND, (char *)&opt, sizeof(int));
+	}
 #ifdef REUSE
 	{
 		int opt;
@@ -565,7 +597,7 @@ int doconnect(struct clientparam * param){
 	if(param->srv->so._bind(param->sostate, param->remsock, (struct sockaddr*)&param->sinsl, SASIZE(&param->sinsl))==-1) {
 		return 12;
 	}
-	
+
 	if(param->operation >= 256 || (param->operation & CONNECT)){
 		if(connectwithpoll(param, param->remsock,(struct sockaddr *)&param->sinsr,SASIZE(&param->sinsr),CONNECT_TO)) {
 			return 13;

src/proxymain.c

@@ -279,6 +279,9 @@ int MODULEMAINFUNC (int argc, char** argv){
 	"\n"
 	" -iIP ip address or internal interface (clients are expected to connect)\n"
 	" -eIP ip address or external interface (outgoing connection will have this)\n"
+#ifndef _WIN32
+	" -k outgoing connection will have local IP where client connected, thus ignores -e (useful in AnyIP case)\n"
+#endif
 	" -rHOST:PORT Use IP:port for connect back proxy instead of listen port\n"
 	" -RHOST:PORT Use PORT to listen connect back proxy connection to pass data to\n"
 	" -4 Use IPv4 for outgoing connections\n"
@@ -417,6 +420,13 @@ int MODULEMAINFUNC (int argc, char** argv){
 #endif
 			}
 			break;
+#ifndef _WIN32
+		 case 'k':
+			{
+				srv.keepip = 1;
+			}
+			break;
+#endif
 		 case 'N':
 			getip46(46, (unsigned char *)argv[i]+2, (struct sockaddr *)&srv.extNat);
 			break;
@@ -806,6 +816,7 @@ int MODULEMAINFUNC (int argc, char** argv){
 		}
 		else {
 			new_sock = srv.so._accept(srv.so.state, sock, (struct sockaddr*)&defparam.sincr, &size);
+
 			if(new_sock == INVALID_SOCKET){
 #ifdef _WIN32
 				switch(WSAGetLastError()){
@@ -981,6 +992,7 @@ void srvinit(struct srvparam * srv, struct clientparam *param){
  srv->logdumpcli = conf.logdumpcli;
  srv->cbsock = INVALID_SOCKET; 
  srv->needuser = 1;
+ srv->keepip = 0;
 #ifdef WITHSPLICE
  srv->usesplice = 1;
 #endif

src/structures.h

@@ -491,6 +491,7 @@ struct srvparam {
 	int paused, version;
 	int singlepacket;
 	int usentlm;
+	int keepip;
 	int needuser;
 	int silent;
 	int transparent;