Merge pull request #840 from DanWin/increase-listen-backlog

Add backlog configuration

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>

man/3proxy.cfg.3

@@ -482,8 +482,18 @@ External or -e can be given twice: once with IPv4 and once with IPv6 address.
 .B maxconn
 <number>
 .br
- sets maximum number of simulationeous connections to each services
-started after this command. Default is 100.
+ sets maximum number of simulationeous connections to each service
+started after this command on network level. Default is 100.
+.br
+ To limit clients, use connlim instead. maxconn will silently ignore
+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/8. Maximum value is capped by kernel tunable somaxconn.
 
 .br
 .B service

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, 0, 0, 0, 0, 0, 0, 2,
 	0, 0, 0,
 	6, 600,
 	1048576,

src/conf.c

@@ -565,6 +565,14 @@ 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.maxchild < 0) {
+		return(1);
+	}
+	return 0;
+}
+
 static int h_flush(int argc, unsigned char **argv){
 	freeacl(conf.acl);
 	conf.acl = NULL;
@@ -1609,8 +1617,9 @@ struct commands commandhandlers[]={
 	{commandhandlers+62, "noforce", h_noforce, 1, 1},
 	{commandhandlers+63, "parentretries", h_parentretries, 2, 2},
 	{commandhandlers+64,  "auto", h_proxy, 1, 0},
+	{commandhandlers+65, "backlog", h_backlog, 2, 2},
 #ifndef NORADIUS
-	{commandhandlers+65, "radius", h_radius, 3, 0},
+	{commandhandlers+66, "radius", h_radius, 3, 0},
 #endif
 	{specificcommands, 	 "", h_noop, 1, 0}
 };
@@ -1855,6 +1864,7 @@ void freeconf(struct extparam *confp){
  *SAFAMILY(&confp->intsa) = AF_INET;
  *SAFAMILY(&confp->extsa) = AF_INET;
  confp->maxchild = 100;
+ confp->backlog = 0;
  resolvfunc = NULL;
  numservers = 0;
  acl = confp->acl;

src/proxymain.c

@@ -649,7 +649,7 @@ int MODULEMAINFUNC (int argc, char** argv){
 		}
 	}
  	if(!isudp){
- 		if(so._listen (sock, 1 + (srv.maxchild>>4))==-1) {
+		if(so._listen (sock, srv.backlog?srv.backlog : 1+(srv.maxchild>>3))==-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){

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;