From 9a6908e623901a6e5c57125a188342b8035e14b9 Mon Sep 17 00:00:00 2001
From: Daniel Winzen <daniel@danwin1210.de>
Date: Tue, 8 Nov 2022 15:01:39 +0100
Subject: [PATCH] Add backlog config option

---
 doc/html/howtoe.html |  2 +-
 man/3proxy.cfg.3     |  6 ++++++
 src/common.c         |  2 +-
 src/conf.c           | 11 +++++++++++
 src/proxymain.c      |  3 ++-
 src/structures.h     |  3 ++-
 6 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/doc/html/howtoe.html b/doc/html/howtoe.html
index 8adcfb0..9d49696 100644
--- a/doc/html/howtoe.html
+++ b/doc/html/howtoe.html
@@ -20,7 +20,7 @@
   <li><a href="#NOTHING">How to make 3proxy start</a></li>
     <li><a href="#LIMITS">How to make limitation (access, bandwidth, traffic, connections) work</a></li>
     <li><a href="#SERVICE">How to make 3proxy to run as a service</a></li>
-    <li><a href="#INTEXT">How to understand internal ¨ external</a></li>
+    <li><a href="#INTEXT">How to understand internal and external</a></li>
     <li><a href="#ODBC">How to make ODBC logging work?</a></li>
     <li><a href="#IPV6">How to make IPv6 work</a></li>
     <li><a href="#CRASH">How to fix 3proxy crashes</a></li>
diff --git a/man/3proxy.cfg.3 b/man/3proxy.cfg.3
index 83455d4..3f38088 100644
--- a/man/3proxy.cfg.3
+++ b/man/3proxy.cfg.3
@@ -489,6 +489,12 @@ started after this command on network level. Default is 100.
 new connections, while connlim will report back to the client that
 the connection limit has been reached.
 
+.br
+.B backlog
+.br
+ sets the listening socket backlog of new connections. Default is
+1+(maxconn>>3). Maximum value is capped by kernel tunable somaxconn.
+
 .br
 .B service
 .br
diff --git a/src/common.c b/src/common.c
index 81839fe..462133d 100644
--- a/src/common.c
+++ b/src/common.c
@@ -102,7 +102,7 @@ struct extparam conf = {
 	NULL,
 	0,
 	0, -1, 0, 0, 0, 0, 
-	0, 500, 0, 0, 0, 0, 0, 2,
+	0, 500, 13, 0, 0, 0, 0, 0, 2,
 	0, 0, 0,
 	6, 600,
 	1048576,
diff --git a/src/conf.c b/src/conf.c
index 4cbe211..392b73e 100644
--- a/src/conf.c
+++ b/src/conf.c
@@ -550,6 +550,7 @@ static int h_maxconn(int argc, unsigned char **argv){
 	if(!conf.maxchild) {
 		return(1);
 	}
+	conf.backlog = 1 + (conf.maxchild>>3);
 #ifndef _WIN32
 	{
 		struct rlimit rl;
@@ -565,6 +566,14 @@ static int h_maxconn(int argc, unsigned char **argv){
 	return 0;
 }
 
+static int h_backlog(int argc, unsigned char **argv){
+	conf.backlog = atoi((char *)argv[1]);
+	if(!conf.backlog) {
+		return(1);
+	}
+	return 0;
+}
+
 static int h_flush(int argc, unsigned char **argv){
 	freeacl(conf.acl);
 	conf.acl = NULL;
@@ -1612,6 +1621,7 @@ struct commands commandhandlers[]={
 #ifndef NORADIUS
 	{commandhandlers+65, "radius", h_radius, 3, 0},
 #endif
+	{commandhandlers+66, "backlog", h_backlog, 2, 2},
 	{specificcommands, 	 "", h_noop, 1, 0}
 };
 
@@ -1855,6 +1865,7 @@ void freeconf(struct extparam *confp){
  *SAFAMILY(&confp->intsa) = AF_INET;
  *SAFAMILY(&confp->extsa) = AF_INET;
  confp->maxchild = 100;
+ confp->backlog = 13;
  resolvfunc = NULL;
  numservers = 0;
  acl = confp->acl;
diff --git a/src/proxymain.c b/src/proxymain.c
index 5cf6d6c..08ed586 100644
--- a/src/proxymain.c
+++ b/src/proxymain.c
@@ -649,7 +649,7 @@ int MODULEMAINFUNC (int argc, char** argv){
 		}
 	}
  	if(!isudp){
-		if(so._listen (sock, srv.maxchild)==-1) {
+		if(so._listen (sock, srv.backlog)==-1) {
 			sprintf((char *)buf, "listen(): %s", strerror(errno));
 			if(!srv.silent)dolog(&defparam, buf);
 			return -4;
@@ -917,6 +917,7 @@ void srvinit(struct srvparam * srv, struct clientparam *param){
  srv->authfunc = conf.authfunc;
  srv->usentlm = 0;
  srv->maxchild = conf.maxchild;
+ srv->backlog = conf.backlog;
  srv->stacksize = conf.stacksize;
  srv->time_start = time(NULL);
  if(havelog && conf.logtarget){
diff --git a/src/structures.h b/src/structures.h
index 5adb361..8d41374 100644
--- a/src/structures.h
+++ b/src/structures.h
@@ -429,6 +429,7 @@ struct srvparam {
 	SOCKET srvsock, cbsock;
 	int childcount;
 	int maxchild;
+	int backlog;
 	int paused, version;
 	int singlepacket;
 	int usentlm;
@@ -578,7 +579,7 @@ struct extparam {
 	struct srvparam *services;
 	int stacksize,
 		threadinit, counterd, haveerror, rotate, paused, archiverc,
-		demon, maxchild, needreload, timetoexit, version, noforce, bandlimver, parentretries;
+		demon, maxchild, backlog, needreload, timetoexit, version, noforce, bandlimver, parentretries;
 	int authcachetype, authcachetime;
 	int filtermaxsize;
 	int gracetraf, gracenum, gracedelay;