From b17b36cbcecb5f1407ba31ec2cb93cb4f25871b7 Mon Sep 17 00:00:00 2001
From: z3APA3A <3APA3A@3proxy.ru>
Date: Mon, 14 Aug 2017 18:22:15 +0300
Subject: [PATCH] Add support to bind to interface (-Di / -Do) via
 SO_BINDTODEVICE

---
 src/common.c     |  4 +++-
 src/proxymain.c  | 19 ++++++++++++++++++-
 src/structures.h |  4 ++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/common.c b/src/common.c
index dfc3dd8..96e4e81 100644
--- a/src/common.c
+++ b/src/common.c
@@ -714,7 +714,9 @@ int doconnect(struct clientparam * param){
 #endif
 	}
 #endif
-
+#ifdef SO_BINDTODEVICE
+	if(param->srv->obindtodevice) so._setsockopt(param->remsock, SOL_SOCKET, SO_BINDTODEVICE, param->srv->obindtodevice, strlen(param->srv->obindtodevice) + 1);
+#endif
 	if(SAISNULL(&param->sinsl)){
 #ifndef NOIPV6
 		if(*SAFAMILY(&param->sinsr) == AF_INET6) param->sinsl = param->srv->extsa6;
diff --git a/src/proxymain.c b/src/proxymain.c
index 6e8f9f4..69db547 100644
--- a/src/proxymain.c
+++ b/src/proxymain.c
@@ -1,6 +1,6 @@
 /*
    3APA3A simpliest proxy server
-   (c) 2002-2016 by Vladimir Dubrovin <3proxy@3proxy.ru>
+   (c) 2002-2017 by Vladimir Dubrovin <3proxy@3proxy.ru>
 
    please read License Agreement
 
@@ -176,6 +176,10 @@ int MODULEMAINFUNC (int argc, char** argv){
 	" -u never ask for username\n"
 	" -u2 always ask for username\n"
 #endif
+#ifdef SO_BINDTODEVICE
+	" -Di(DEVICENAME) bind to incoming device, e.g. eth1\n"
+	" -Do(DEVICENAME) bind to outgoing device, e.g. eth1\n"
+#endif
 #ifdef WITHSLICE
 	" -s Use slice() - faster proxing, but no filtering for data\n"
 #endif
@@ -302,6 +306,12 @@ int MODULEMAINFUNC (int argc, char** argv){
 			if(!conf.demon)daemonize();
 			conf.demon = 1;
 			break;
+#ifdef SO_BINDTODEVICE
+		 case 'D':
+			if(argv[i][2] == 'i') srv.ibindtodevice = mystrdup(argv[i] + 3);
+			else if(argv[i][2] == 'o') srv.obindtodevice = mystrdup(argv[i] + 3);
+			break;
+#endif
 		 case 'l':
 			srv.logfunc = logstdout;
 			if(srv.logtarget) myfree(srv.logtarget);
@@ -565,6 +575,9 @@ int MODULEMAINFUNC (int argc, char** argv){
 #ifdef SO_REUSEPORT
 		opt = 1;
 		so._setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, (char *)&opt, sizeof(int));
+#endif
+#ifdef SO_BINDTODEVICE
+		if(srv.ibindtodevice) so._setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, srv.ibindtodevice, strlen(srv.ibindtodevice) + 1);
 #endif
 	}
 	size = sizeof(srv.intsa);
@@ -916,6 +929,10 @@ void srvfree(struct srvparam * srv){
  if(srv->logtarget) myfree(srv->logtarget);
  if(srv->logformat) myfree(srv->logformat);
  if(srv->nonprintable) myfree(srv->nonprintable);
+#ifdef SO_BINDTODEVICE
+ if(srv->ibindtodevice) myfree(srv->ibindtodevice);
+ if(srv->obindtodevice) myfree(srv->obindtodevice);
+#endif
 }
 
 
diff --git a/src/structures.h b/src/structures.h
index b6f89fc..89b83cc 100644
--- a/src/structures.h
+++ b/src/structures.h
@@ -417,6 +417,10 @@ struct srvparam {
 	struct pollfd fds;
 	FILE *stdlog;
 	unsigned char * target;
+#ifdef SO_BINDTODEVICE
+	char * ibindtodevice;
+	char * obindtodevice;
+#endif
 	struct auth *authenticate;
 	struct pollfd * srvfds;
 	struct ace *acl;