v1.2(development beta 1, patch 10)

1. Added support of IP forwarding(#7).

Author: bilintsui

README.md

@@ -10,6 +10,7 @@ Minecraft Versions before 12w04a are **NOT SUPPORTED**!
 ## Features
 * Support reverse proxy for Minecraft servers by server address in the handshake packet which client send to.
 * Support rewrite server address and server port to camouflage connection which using official server address. (eg: pretend to be a normal connection to Hypixel, avoiding their server address check.)
+* Support IP forwarding using HAProxy's Proxy Protocol. (But refuses any incoming connection using this protocol.)
 
 ## Requirements
 * Linux
@@ -24,10 +25,10 @@ Minecraft Versions before 12w04a are **NOT SUPPORTED**!
 ## Files
 * mcrelay.c: Source code of Main program.
 * mcrelay.conf.example: config file example of mcrelay.
-* mcrelay.service.forking.example: service unit file of mcrelay for systemd(using runmode: forking).
-* mcrelay.service.simple.example: service unit file of mcrelay for systemd(using runmode: simple).
+* mcrelay.service.forking.example: service unit file of mcrelay for systemd. (using runmode: forking)
+* mcrelay.service.simple.example: service unit file of mcrelay for systemd. (using runmode: simple)
 * mod: directory of essential modules.
-* version.json: version manifest
+* version.json: version manifest.
 * loglevel.info: definations for messages.
 
 ## Compile
@@ -60,6 +61,7 @@ proxy_pass proxy_type
 	ident_name destination_object
 default destination_object
 </pre>
+
 ### Explanation
 * log: set log file.
 >* logfile_path: path of the file which logs saved to.
@@ -71,18 +73,19 @@ default destination_object
 >>* port: the port you wish to bind as an Internet Service. Valid range: 1-65535.
 * proxy_pass: list of relay/relay+rewrites.
 >* proxy_type: type of proxies, "relay" for raw relay, "rewrite" for relay with server address camouflage enabled.
->* ident_name: name of destination identification. Usually a Fully Qualified Domain Name(FQDN) by CNAME to your server.
+>>* You can add "p" suffix (i.e. "relayp" or "rewritep") to enable IP forwarding. (Need downstream supports HAProxy's Proxy Protocol, otherwise your connection will be aborted.)
+>* ident_name: name of destination identification. Usually a Fully Qualified Domain Name (FQDN) by CNAME to your server.
 >* destination_object: (format: "address_d[:port]")
 >>* address_d: the address you wish to connect. Both FQDN or x.x.x.x allowed.
 >>* port: optional, the port you wish to connect. Valid range: 1-65535.
 
-If not set, the server will detect SRV record first(defined in address_d).
+If not set, the server will detect SRV record first. (defined in address_d)
 
 If SRV record resolve failed, it will fallback to normal address resolve, also connect to this address with port 25565.
 
 **For rewrite enabled relay, it will use actual connect configuration to rewrite.**
->>* path: the socket file you wish to connect.
 * default: optional, set a default server to connect when client don't match any valid virtual host. (Intentionally not support rewrite here.) (Security suggestion: Don't use this feature unless you know what you are doing.)
+
 ### Example
 <pre>
 log /var/log/mcrelay/mcrelay.log
@@ -96,7 +99,7 @@ proxy_pass relay
 default 192.168.1.254:25565
 </pre>
 
-## Instruction of using a DNS-based redirection(SRV)
+## Instruction of using a DNS-based redirection (SRV)
 If you are using a SRV record to provide your service, you should follow the instructions below.
 
 Otherwise, your user will see the message of using a wrong address to connect.
@@ -110,3 +113,11 @@ If you provide "srvrecord.example.com" to your user, you should set your vhostna
 * For Minecraft version from 21w20a to 1.17, use "srvrecord.example.com".
 
 For compatibility, it's recommended to add both of them to your configuration.
+
+## IP Forwarding
+You can provide the real client address and port through HAProxy's Proxy Protocol by this feature.
+
+It's compatible with any server which support this protocol. (e.g. Bungeecord)
+
+### Bungeecord
+To use this feature correctly, turn on the "proxy_protocol" in the "config.yml". ("false" to "true")

mod/config.h

@@ -27,7 +27,7 @@ typedef struct
 } conf_bind;
 typedef struct
 {
-	unsigned short enable_rewrite;
+	unsigned short enable_rewrite,enable_pheader;
 	char from[512],to_inet_addr[512];
 	unsigned short to_inet_port;
 	unsigned short to_inet_hybridmode;

mod/linux/config.c

@@ -74,6 +74,15 @@ void config_dump(conf * source)
 				printf("Rewrite\t\tEnabled\n");
 				break;
 		}
+		switch(source->relay[i].enable_pheader)
+		{
+			case 0:
+				printf("PHeader\t\tDisabled\n");
+				break;
+			case 1:
+				printf("PHeader\t\tEnabled\n");
+				break;
+		}
 		printf("vhost\t\t%s\n",source->relay[i].from);
 		printf("Address\t\t%s\n",source->relay[i].to_inet_addr);
 		switch(source->relay[i].to_inet_hybridmode)
@@ -176,14 +185,26 @@ int config_load(char * filename, conf * result)
 		}
 		else if(strcmp(key,"proxy_pass")==0)
 		{
-			int enable_rewrite;
+			int enable_rewrite,enable_pheader;
 			if(strcmp(value,"rewrite")==0)
 			{
 				enable_rewrite=1;
+				enable_pheader=0;
 			}
 			else if(strcmp(value,"relay")==0)
 			{
 				enable_rewrite=0;
+				enable_pheader=0;
+			}
+			else if(strcmp(value,"rewritep")==0)
+			{
+				enable_rewrite=1;
+				enable_pheader=1;
+			}
+			else if(strcmp(value,"relayp")==0)
+			{
+				enable_rewrite=0;
+				enable_pheader=1;
 			}
 			else
 			{
@@ -195,6 +216,7 @@ int config_load(char * filename, conf * result)
 			{
 				tmpptr++;
 				result->relay[rec_relay].enable_rewrite=enable_rewrite;
+				result->relay[rec_relay].enable_pheader=enable_pheader;
 				if(strsplit_fieldcount(tmpptr,' ')!=2)
 				{
 					line_reccount++;
@@ -253,6 +275,7 @@ int config_load(char * filename, conf * result)
 				return CONF_EDEFPROXYDUP;
 			}
 			relay_default.enable_rewrite=0;
+			relay_default.enable_pheader=0;
 			strcpy(relay_default.from,"*");
 			if(strsplit_fieldcount(tmpptr,':')==1)
 			{

mod/linux/main.c

@@ -20,7 +20,7 @@
 #include <unistd.h>
 const char * version_str="1.2-beta1";
 const char * year_str="2020-2021";
-const short version_internal=45;
+const short version_internal=46;
 conf config;
 char configfile[512],cwd[512],config_logfull[BUFSIZ];
 unsigned short config_runmode=1;

mod/linux/misc.c

@@ -13,12 +13,13 @@
 #include <string.h>
 int backbone(int socket_in, int * socket_out, char * logfile, unsigned short runmode, conf conf_in, struct sockaddr_in addrinfo_in)
 {
-	unsigned char inbound[BUFSIZ],outbound[BUFSIZ],rewrited[BUFSIZ];
-	int packlen_inbound,packlen_outbound,packlen_rewrited;
+	unsigned char inbound[BUFSIZ],outbound[BUFSIZ],rewrited[BUFSIZ],pheader[105];
+	int packlen_inbound,packlen_outbound,packlen_rewrited,packlen_pheader;
 	struct sockaddr_in addr_outbound;
-	bzero(inbound,BUFSIZ);
-	bzero(outbound,BUFSIZ);
-	bzero(rewrited,BUFSIZ);
+	memset(inbound,0,BUFSIZ);
+	memset(outbound,0,BUFSIZ);
+	memset(rewrited,0,BUFSIZ);
+	memset(pheader,0,105);
 	packlen_inbound=recv(socket_in,inbound,BUFSIZ,0);
 	if(packlen_inbound==0)
 	{
@@ -89,12 +90,16 @@ int backbone(int socket_in, int * socket_out, char * logfile, unsigned short run
 				mkoutbound_status=NET_ENORECORD;
 			}
 			*socket_out=net_socket(NETSOCK_CONN,AF_INET,connaddr,proxyinfo->to_inet_port,0);
-			free(connaddr);
-			connaddr=NULL;
 			if(*socket_out==-1)
 			{
 				mkoutbound_status=NET_ECONNECT;
 			}
+			char * connaddr_strp=inet_ntoa(*((struct in_addr *)connaddr));
+			free(connaddr);
+			connaddr=NULL;
+			char * connaddr_str=(char *)malloc(strlen(connaddr_strp)+1);
+			strcpy(connaddr_str,connaddr_strp);
+			connaddr_strp=NULL;
 			if(mkoutbound_status!=0)
 			{
 				outmsg_level=1;
@@ -107,6 +112,11 @@ int backbone(int socket_in, int * socket_out, char * logfile, unsigned short run
 			{
 				case 0:
 					mksysmsg(0,logfile,runmode,conf_in.loglevel,outmsg_level,"src: %s:%d, type: motd, vhost: %s, dst: %s:%d, status: accept\n",inet_ntoa(addrinfo_in.sin_addr),ntohs(addrinfo_in.sin_port),proxyinfo->from,proxyinfo->to_inet_addr,proxyinfo->to_inet_port);
+					if(proxyinfo->enable_pheader==1)
+					{
+						packlen_pheader=sprintf(pheader,"PROXY TCP4 %s %s %d %d\r\n",inet_ntoa(addrinfo_in.sin_addr),connaddr_str,ntohs(addrinfo_in.sin_port),proxyinfo->to_inet_port);
+						send(*socket_out,pheader,packlen_pheader,0);
+					}
 					if(proxyinfo->enable_rewrite==1)
 					{
 						strcpy(inbound_info.address,proxyinfo->to_inet_addr);
@@ -200,12 +210,16 @@ int backbone(int socket_in, int * socket_out, char * logfile, unsigned short run
 				mkoutbound_status=NET_ENORECORD;
 			}
 			*socket_out=net_socket(NETSOCK_CONN,AF_INET,connaddr,proxyinfo->to_inet_port,0);
-			free(connaddr);
-			connaddr=NULL;
 			if(*socket_out==-1)
 			{
 				mkoutbound_status=NET_ECONNECT;
 			}
+			char * connaddr_strp=inet_ntoa(*((struct in_addr *)connaddr));
+			free(connaddr);
+			connaddr=NULL;
+			char * connaddr_str=(char *)malloc(strlen(connaddr_strp)+1);
+			strcpy(connaddr_str,connaddr_strp);
+			connaddr_strp=NULL;
 			if(mkoutbound_status!=0)
 			{
 				outmsg_level=1;
@@ -218,6 +232,11 @@ int backbone(int socket_in, int * socket_out, char * logfile, unsigned short run
 			{
 				case 0:
 					mksysmsg(0,logfile,runmode,conf_in.loglevel,outmsg_level,"src: %s:%d, type: game, vhost: %s, dst: %s:%d, status: accept, username: %s\n",inet_ntoa(addrinfo_in.sin_addr),ntohs(addrinfo_in.sin_port),proxyinfo->from,proxyinfo->to_inet_addr,proxyinfo->to_inet_port,inbound_info.username);
+					if(proxyinfo->enable_pheader==1)
+					{
+						packlen_pheader=sprintf(pheader,"PROXY TCP4 %s %s %d %d\r\n",inet_ntoa(addrinfo_in.sin_addr),connaddr_str,ntohs(addrinfo_in.sin_port),proxyinfo->to_inet_port);
+						send(*socket_out,pheader,packlen_pheader,0);
+					}
 					if(proxyinfo->enable_rewrite==1)
 					{
 						strcpy(inbound_info.address,proxyinfo->to_inet_addr);
@@ -318,12 +337,16 @@ int backbone(int socket_in, int * socket_out, char * logfile, unsigned short run
 			mkoutbound_status=NET_ENORECORD;
 		}
 		*socket_out=net_socket(NETSOCK_CONN,AF_INET,connaddr,proxyinfo->to_inet_port,0);
-		free(connaddr);
-		connaddr=NULL;
 		if(*socket_out==-1)
 		{
 			mkoutbound_status=NET_ECONNECT;
 		}
+		char * connaddr_strp=inet_ntoa(*((struct in_addr *)connaddr));
+		free(connaddr);
+		connaddr=NULL;
+		char * connaddr_str=(char *)malloc(strlen(connaddr_strp)+1);
+		strcpy(connaddr_str,connaddr_strp);
+		connaddr_strp=NULL;
 		if(mkoutbound_status!=0)
 		{
 			outmsg_level=1;
@@ -350,6 +373,11 @@ int backbone(int socket_in, int * socket_out, char * logfile, unsigned short run
 				{
 					mksysmsg(0,logfile,runmode,conf_in.loglevel,outmsg_level,"src: %s:%d, type: game, vhost: %s, dst: %s:%d, status: accept, username: %s\n",inet_ntoa(addrinfo_in.sin_addr),ntohs(addrinfo_in.sin_port),proxyinfo->from,proxyinfo->to_inet_addr,proxyinfo->to_inet_port,inbound_info.username);
 				}
+				if(proxyinfo->enable_pheader==1)
+				{
+					packlen_pheader=sprintf(pheader,"PROXY TCP4 %s %s %d %d\r\n",inet_ntoa(addrinfo_in.sin_addr),connaddr_str,ntohs(addrinfo_in.sin_port),proxyinfo->to_inet_port);
+					send(*socket_out,pheader,packlen_pheader,0);
+				}
 				if(proxyinfo->enable_rewrite==1)
 				{
 					strcpy(inbound_info.address,proxyinfo->to_inet_addr);

version.json

@@ -170,5 +170,9 @@
 	{
 		"version": 45,
 		"names": ["1.2-beta1-patch9"]
+	{
+		"version": 46,
+		"names": ["1.2-beta1-patch10"]
+	}
 	}
 ]