X-Git-Url: https://arthur.barton.de/cgi-bin/gitweb.cgi?p=ngircd-alex.git;a=blobdiff_plain;f=src%2Fngircd%2Fconn.c;h=397bc91586c7bcdf2ddb7a722c574bec374278b0;hp=2d5e1295f4341b1675db274f0263f66fda92b3f8;hb=25dd193e9b49b38db39cf549f94df4ba11812fe9;hpb=d7ad956a06af2bde1cfcf2ed8194b6a84d69d968

diff --git a/src/ngircd/conn.c b/src/ngircd/conn.c
index 2d5e1295..397bc915 100644
--- a/src/ngircd/conn.c
+++ b/src/ngircd/conn.c
@@ -7,17 +7,19 @@
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  * Please read the file COPYING, README and AUTHORS for more information.
- *
- * Connection management
  */
 
-
 #define CONN_MODULE
 
 #include "portab.h"
 #include "conf-ssl.h"
 #include "io.h"
 
+/**
+ * @file
+ * Connection management
+ */
+
 #include "imp.h"
 #include <assert.h>
 #ifdef PROTOTYPES
@@ -71,10 +73,6 @@
 #include "resolve.h"
 #include "tool.h"
 
-#ifdef ZEROCONF
-# include "rendezvous.h"
-#endif
-
 #include "exp.h"
 
 
@@ -82,6 +80,7 @@
 
 #define MAX_COMMANDS 3
 #define MAX_COMMANDS_SERVER 10
+#define MAX_COMMANDS_SERVICE MAX_COMMANDS_SERVER
 
 
 static bool Handle_Write PARAMS(( CONN_ID Idx ));
@@ -124,8 +123,9 @@ static void cb_clientserver PARAMS((int sock, short what));
 /**
  * IO callback for listening sockets: handle new connections. This callback
  * gets called when a new non-SSL connection should be accepted.
- * @param sock Socket descriptor
- * @param irrelevant (ignored IO specification)
+ *
+ * @param sock		Socket descriptor.
+ * @param irrelevant	(ignored IO specification)
  */
 static void
 cb_listen(int sock, short irrelevant)
@@ -139,8 +139,9 @@ cb_listen(int sock, short irrelevant)
 /**
  * IO callback for listening SSL sockets: handle new connections. This callback
  * gets called when a new SSL-enabled connection should be accepted.
- * @param sock Socket descriptor
- * @param irrelevant (ignored IO specification)
+ *
+ * @param sock		Socket descriptor.
+ * @param irrelevant	(ignored IO specification)
  */
 static void
 cb_listen_ssl(int sock, short irrelevant)
@@ -158,8 +159,9 @@ cb_listen_ssl(int sock, short irrelevant)
 
 /**
  * IO callback for new outgoing non-SSL server connections.
- * @param sock Socket descriptor
- * @param what IO specification (IO_WANTREAD/IO_WANTWRITE/...)
+ *
+ * @param sock	Socket descriptor.
+ * @param what	IO specification (IO_WANTREAD/IO_WANTWRITE/...).
  */
 static void
 cb_connserver(int sock, UNUSED short what)
@@ -236,13 +238,16 @@ cb_connserver(int sock, UNUSED short what)
 
 /**
  * Login to a remote server.
- * @param idx Connection index
+ *
+ * @param idx	Connection index.
  */
 static void
 server_login(CONN_ID idx)
 {
-	Log( LOG_INFO, "Connection %d with \"%s:%d\" established. Now logging in ...", idx,
-			My_Connections[idx].host, Conf_Server[Conf_GetServer( idx )].port );
+	Log(LOG_INFO,
+	    "Connection %d (socket %d) with \"%s:%d\" established. Now logging in ...",
+	    idx, My_Connections[idx].sock, My_Connections[idx].host,
+	    Conf_Server[Conf_GetServer(idx)].port);
 
 	io_event_setcb( My_Connections[idx].sock, cb_clientserver);
 	io_event_add( My_Connections[idx].sock, IO_WANTREAD|IO_WANTWRITE);
@@ -256,8 +261,9 @@ server_login(CONN_ID idx)
 #ifdef SSL_SUPPORT
 /**
  * IO callback for new outgoing SSL-enabled server connections.
- * @param sock Socket descriptor
- * @param what IO specification (IO_WANTREAD/IO_WANTWRITE/...)
+ *
+ * @param sock		Socket descriptor.
+ * @param unused	(ignored IO specification)
  */
 static void
 cb_connserver_login_ssl(int sock, short unused)
@@ -290,8 +296,9 @@ cb_connserver_login_ssl(int sock, short unused)
 
 /**
  * IO callback for established non-SSL client and server connections.
- * @param sock Socket descriptor
- * @param what IO specification (IO_WANTREAD/IO_WANTWRITE/...)
+ *
+ * @param sock	Socket descriptor.
+ * @param what	IO specification (IO_WANTREAD/IO_WANTWRITE/...).
  */
 static void
 cb_clientserver(int sock, short what)
@@ -323,8 +330,9 @@ cb_clientserver(int sock, short what)
 #ifdef SSL_SUPPORT
 /**
  * IO callback for established SSL-enabled client and server connections.
- * @param sock Socket descriptor
- * @param what IO specification (IO_WANTREAD/IO_WANTWRITE/...)
+ *
+ * @param sock	Socket descriptor.
+ * @param what	IO specification (IO_WANTREAD/IO_WANTWRITE/...).
  */
 static void
 cb_clientserver_ssl(int sock, short what)
@@ -436,6 +444,14 @@ Conn_CloseAllSockets(void)
 }
 
 
+/**
+ * Initialize listening ports.
+ *
+ * @param a		Array containing the ports the daemon should listen on.
+ * @param listen_addr	Address the socket should listen on (can be "0.0.0.0").
+ * @param func		IO callback function to register.
+ * @returns		Number of listening sockets created.
+ */
 static unsigned int
 ports_initlisteners(array *a, const char *listen_addr, void (*func)(int,short))
 {
@@ -468,7 +484,8 @@ ports_initlisteners(array *a, const char *listen_addr, void (*func)(int,short))
 
 /**
  * Initialize all listening sockets.
- * @return Number of created listening sockets
+ *
+ * @returns	Number of created listening sockets
  */
 GLOBAL unsigned int
 Conn_InitListeners( void )
@@ -509,15 +526,15 @@ Conn_InitListeners( void )
 } /* Conn_InitListeners */
 
 
+/**
+ * Shut down all listening sockets.
+ */
 GLOBAL void
 Conn_ExitListeners( void )
 {
 	/* Close down all listening sockets */
 	int *fd;
 	size_t arraylen;
-#ifdef ZEROCONF
-	Rendezvous_UnregisterListeners( );
-#endif
 
 	arraylen = array_length(&My_Listeners, sizeof (int));
 	Log(LOG_INFO,
@@ -534,6 +551,14 @@ Conn_ExitListeners( void )
 } /* Conn_ExitListeners */
 
 
+/**
+ * Bind a socket to a specific (source) address.
+ *
+ * @param addr			Address structure.
+ * @param listen_addrstr	Source address as string.
+ * @param Port			Port number.
+ * @returns			true on success, false otherwise.
+ */
 static bool
 InitSinaddrListenAddr(ng_ipaddr_t *addr, const char *listen_addrstr, UINT16 Port)
 {
@@ -549,6 +574,14 @@ InitSinaddrListenAddr(ng_ipaddr_t *addr, const char *listen_addrstr, UINT16 Port
 }
 
 
+/**
+ * Set a socket to "IPv6 only". If the given socket doesn't belong to the
+ * AF_INET6 family, or the operating system doesn't support this functionality,
+ * this function retruns silently.
+ *
+ * @param af	Address family of the socket.
+ * @param sock	Socket handle.
+ */
 static void
 set_v6_only(int af, int sock)
 {
@@ -567,16 +600,20 @@ set_v6_only(int af, int sock)
 }
 
 
-/* return new listening port file descriptor or -1 on failure */
+/**
+ * Initialize new listening port.
+ *
+ * @param listen_addr	Local address to bind the socet to (can be 0.0.0.0).
+ * @param Port		Port number on which the new socket should be listening.
+ * @returns		file descriptor of the socket or -1 on failure.
+ */
 static int
 NewListener(const char *listen_addr, UINT16 Port)
 {
 	/* Create new listening socket on specified port */
 	ng_ipaddr_t addr;
 	int sock, af;
-#ifdef ZEROCONF
-	char name[CLIENT_ID_LEN], *info;
-#endif
+
 	if (!InitSinaddrListenAddr(&addr, listen_addr, Port))
 		return -1;
 
@@ -612,44 +649,17 @@ NewListener(const char *listen_addr, UINT16 Port)
 		return -1;
 	}
 
-	Log(LOG_INFO, "Now listening on [%s]:%d (socket %d).", ng_ipaddr_tostr(&addr), Port, sock);
-
-#ifdef ZEROCONF
-	/* Get best server description text */
-	if( ! Conf_ServerInfo[0] ) info = Conf_ServerName;
-	else
-	{
-		/* Use server info string */
-		info = NULL;
-		if( Conf_ServerInfo[0] == '[' )
-		{
-			/* Cut off leading hostname part in "[]" */
-			info = strchr( Conf_ServerInfo, ']' );
-			if( info )
-			{
-				info++;
-				while( *info == ' ' ) info++;
-			}
-		}
-		if( ! info ) info = Conf_ServerInfo;
-	}
-
-	/* Add port number to description if non-standard */
-	if (Port != 6667)
-		snprintf(name, sizeof name, "%s (port %u)", info,
-		 	 (unsigned int)Port);
-	else
-	 	strlcpy(name, info, sizeof name);
-
-	/* Register service */
-	Rendezvous_Register( name, MDNS_TYPE, Port );
-#endif
+	Log(LOG_INFO, "Now listening on [%s]:%d (socket %d).",
+	    ng_ipaddr_tostr(&addr), Port, sock);
 	return sock;
 } /* NewListener */
 
 
 #ifdef SSL_SUPPORT
-/*
+
+/**
+ * Check if SSL library needs to read SSL-protocol related data.
+ *
  * SSL/TLS connections require extra treatment:
  * When either CONN_SSL_WANT_WRITE or CONN_SSL_WANT_READ is set, we
  * need to take care of that first, before checking read/write buffers.
@@ -660,6 +670,9 @@ NewListener(const char *listen_addr, UINT16 Port)
  * If this function returns true, such a condition is met and we have
  * to reverse the condition (check for read even if we've data to write,
  * do not check for read but writeability even if write-buffer is empty).
+ *
+ * @param c	Connection to check.
+ * @returns	true if SSL-library has to read protocol data.
  */
 static bool
 SSL_WantRead(const CONNECTION *c)
@@ -670,6 +683,15 @@ SSL_WantRead(const CONNECTION *c)
 	}
 	return false;
 }
+
+/**
+ * Check if SSL library needs to write SSL-protocol related data.
+ *
+ * Please see description of SSL_WantRead() for full description!
+ *
+ * @param c	Connection to check.
+ * @returns	true if SSL-library has to write protocol data.
+ */
 static bool
 SSL_WantWrite(const CONNECTION *c)
 {
@@ -679,18 +701,23 @@ SSL_WantWrite(const CONNECTION *c)
 	}
 	return false;
 }
+
 #else
+
 static inline bool
 SSL_WantRead(UNUSED const CONNECTION *c)
 { return false; }
+
 static inline bool
 SSL_WantWrite(UNUSED const CONNECTION *c)
 { return false; }
+
 #endif
 
 
 /**
  * "Main Loop": Loop until shutdown or restart is signalled.
+ *
  * This function loops until a shutdown or restart of ngIRCd is signalled and
  * calls io_dispatch() to check for readable and writable sockets every second.
  * It checks for status changes on pending connections (e. g. when a hostname
@@ -708,10 +735,6 @@ Conn_Handler(void)
 	while (!NGIRCd_SignalQuit && !NGIRCd_SignalRestart) {
 		t = time(NULL);
 
-#ifdef ZEROCONF
-		Rendezvous_Handler();
-#endif
-
 		/* Check configured servers and established links */
 		Check_Servers();
 		Check_Connections();
@@ -814,12 +837,14 @@ Conn_Handler(void)
 
 /**
  * Write a text string into the socket of a connection.
+ *
  * This function automatically appends CR+LF to the string and validates that
  * the result is a valid IRC message (oversized messages are shortened, for
  * example). Then it calls the Conn_Write() function to do the actual sending.
- * @param Idx Index fo the connection.
- * @param Format Format string, see printf().
- * @return true on success, false otherwise.
+ *
+ * @param Idx		Index fo the connection.
+ * @param Format	Format string, see printf().
+ * @returns		true on success, false otherwise.
  */
 #ifdef PROTOTYPES
 GLOBAL bool
@@ -889,16 +914,17 @@ va_dcl
 
 /**
  * Append Data to the outbound write buffer of a connection.
- * @param Idx Index of the connection.
- * @param Data pointer to the data.
- * @param Len length of Data.
- * @return true on success, false otherwise.
+ *
+ * @param Idx	Index of the connection.
+ * @param Data	pointer to the data.
+ * @param Len	length of Data.
+ * @returns	true on success, false otherwise.
  */
 static bool
 Conn_Write( CONN_ID Idx, char *Data, size_t Len )
 {
 	CLIENT *c;
-	size_t writebuf_limit = WRITEBUFFER_LEN;
+	size_t writebuf_limit = WRITEBUFFER_MAX_LEN;
 	assert( Idx > NONE );
 	assert( Data != NULL );
 	assert( Len > 0 );
@@ -934,7 +960,7 @@ Conn_Write( CONN_ID Idx, char *Data, size_t Len )
 		/* Uncompressed link:
 		 * Check if outbound buffer has enough space for the data. */
 		if (array_bytes(&My_Connections[Idx].wbuf) + Len >=
-		    writebuf_limit) {
+		    WRITEBUFFER_FLUSH_LEN) {
 			/* Buffer is full, flush it. Handle_Write deals with
 			 * low-level errors, if any. */
 			if (!Handle_Write(Idx))
@@ -946,8 +972,8 @@ Conn_Write( CONN_ID Idx, char *Data, size_t Len )
 		if (array_bytes(&My_Connections[Idx].wbuf) + Len >=
 		    writebuf_limit) {
 			Log(LOG_NOTICE,
-			    "Write buffer overflow (connection %d, size %lu byte)!",
-			    Idx,
+			    "Write buffer overflow (connection %d, limit is %lu bytes, %lu bytes new, %lu bytes pending)!",
+			    Idx, writebuf_limit, Len,
 			    (unsigned long)array_bytes(&My_Connections[Idx].wbuf));
 			Conn_Close(Idx, "Write buffer overflow!", NULL, false);
 			return false;
@@ -967,6 +993,17 @@ Conn_Write( CONN_ID Idx, char *Data, size_t Len )
 } /* Conn_Write */
 
 
+/**
+ * Shut down a connection.
+ *
+ * @param Idx		Connection index.
+ * @param LogMsg	Message to write to the log or NULL. If no LogMsg
+ *			is given, the FwdMsg is logged.
+ * @param FwdMsg	Message to forward to remote servers.
+ * @param InformClient	If true, inform the client on the connection which is
+ *			to be shut down of the reason (FwdMsg) and send
+ *			connection statistics before disconnecting it.
+ */
 GLOBAL void
 Conn_Close( CONN_ID Idx, const char *LogMsg, const char *FwdMsg, bool InformClient )
 {
@@ -1020,7 +1057,7 @@ Conn_Close( CONN_ID Idx, const char *LogMsg, const char *FwdMsg, bool InformClie
 		if (FwdMsg)
 			Conn_WriteStr(Idx, "ERROR :%s", FwdMsg);
 		else
-			Conn_WriteStr(Idx, "ERROR :Closing connection.");
+			Conn_WriteStr(Idx, "ERROR :Closing connection");
 	}
 
 	/* Try to write out the write buffer. Note: Handle_Write() eventually
@@ -1111,6 +1148,11 @@ Conn_Close( CONN_ID Idx, const char *LogMsg, const char *FwdMsg, bool InformClie
 } /* Conn_Close */
 
 
+/**
+ * Get current number of connections.
+ *
+ * @returns	Number of current connections.
+ */
 GLOBAL long
 Conn_Count(void)
 {
@@ -1118,6 +1160,11 @@ Conn_Count(void)
 } /* Conn_Count */
 
 
+/**
+ * Get number of maximum simultaneous connections.
+ *
+ * @returns	Number of maximum simultaneous connections.
+ */
 GLOBAL long
 Conn_CountMax(void)
 {
@@ -1125,6 +1172,11 @@ Conn_CountMax(void)
 } /* Conn_CountMax */
 
 
+/**
+ * Get number of connections accepted since the daemon startet.
+ *
+ * @returns	Number of connections accepted.
+ */
 GLOBAL long
 Conn_CountAccepted(void)
 {
@@ -1166,6 +1218,9 @@ Conn_SyncServerStruct(void)
 
 /**
  * Send out data of write buffer; connect new sockets.
+ *
+ * @param Idx	Connection index.
+ * @returns	true on success, false otherwise.
  */
 static bool
 Handle_Write( CONN_ID Idx )
@@ -1230,6 +1285,11 @@ Handle_Write( CONN_ID Idx )
 } /* Handle_Write */
 
 
+/**
+ * Count established connections to a specific IP address.
+ *
+ * @returns	Number of established connections.
+ */
 static int
 Count_Connections(ng_ipaddr_t *a)
 {
@@ -1248,8 +1308,9 @@ Count_Connections(ng_ipaddr_t *a)
 
 /**
  * Initialize new client connection on a listening socket.
- * @param Sock Listening socket descriptor
- * @return Accepted socket descriptor or -1 on error
+ *
+ * @param Sock	Listening socket descriptor.
+ * @returns	Accepted socket descriptor or -1 on error.
  */
 static int
 New_Connection(int Sock)
@@ -1316,7 +1377,7 @@ New_Connection(int Sock)
 		    "Refused connection from %s: too may connections (%ld) from this IP address!",
 		    ip_str, cnt);
 		Simple_Message(new_sock,
-			       "ERROR :Connection refused, too many connections from your IP address!");
+			       "ERROR :Connection refused, too many connections from your IP address");
 		close(new_sock);
 		return -1;
 	}
@@ -1380,10 +1441,10 @@ New_Connection(int Sock)
 
 	identsock = new_sock;
 #ifdef IDENTAUTH
-	if (Conf_NoIdent)
+	if (!Conf_Ident)
 		identsock = -1;
 #endif
-	if (!Conf_NoDNS)
+	if (Conf_DNS)
 		Resolve_Addr(&My_Connections[new_sock].proc_stat, &new_addr,
 			     identsock, cb_Read_Resolver_Result);
 
@@ -1392,6 +1453,9 @@ New_Connection(int Sock)
 } /* New_Connection */
 
 
+/**
+ * Update global connection counters.
+ */
 static void
 Account_Connection(void)
 {
@@ -1403,6 +1467,12 @@ Account_Connection(void)
 } /* Account_Connection */
 
 
+/**
+ * Translate socket handle into connection index.
+ *
+ * @param Sock	Socket handle.
+ * @returns	Connecion index or NONE, if no connection could be found.
+ */
 static CONN_ID
 Socket2Index( int Sock )
 {
@@ -1421,6 +1491,8 @@ Socket2Index( int Sock )
 /**
  * Read data from the network to the read buffer. If an error occures,
  * the socket of this connection will be shut down.
+ *
+ * @param Idx	Connection index.
  */
 static void
 Read_Request( CONN_ID Idx )
@@ -1495,16 +1567,21 @@ Read_Request( CONN_ID Idx )
 
 	/* Update connection statistics */
 	My_Connections[Idx].bytes_in += len;
+	My_Connections[Idx].bps += Handle_Buffer(Idx);
+
+	/* Make sure that there is still a valid client registered */
+	c = Conn_GetClient(Idx);
+	if (!c)
+		return;
 
 	/* Update timestamp of last data received if this connection is
 	 * registered as a user, server or service connection. Don't update
 	 * otherwise, so users have at least Conf_PongTimeout seconds time to
 	 * register with the IRC server -- see Check_Connections().
 	 * Update "lastping", too, if time shifted backwards ... */
-	c = Conn_GetClient(Idx);
-	if (c && (Client_Type(c) == CLIENT_USER
-		  || Client_Type(c) == CLIENT_SERVER
-		  || Client_Type(c) == CLIENT_SERVICE)) {
+	if (Client_Type(c) == CLIENT_USER
+	    || Client_Type(c) == CLIENT_SERVER
+	    || Client_Type(c) == CLIENT_SERVICE) {
 		t = time(NULL);
 		if (My_Connections[Idx].lastdata != t)
 			My_Connections[Idx].bps = 0;
@@ -1515,8 +1592,9 @@ Read_Request( CONN_ID Idx )
 	}
 
 	/* Look at the data in the (read-) buffer of this connection */
-	My_Connections[Idx].bps += Handle_Buffer(Idx);
 	if (Client_Type(c) != CLIENT_SERVER
+	    && Client_Type(c) != CLIENT_UNKNOWNSERVER
+	    && Client_Type(c) != CLIENT_SERVICE
 	    && My_Connections[Idx].bps >= maxbps) {
 		LogDebug("Throttling connection %d: BPS exceeded! (%u >= %u)",
 			 Idx, My_Connections[Idx].bps, maxbps);
@@ -1527,11 +1605,13 @@ Read_Request( CONN_ID Idx )
 
 /**
  * Handle all data in the connection read-buffer.
+ *
  * Data is processed until no complete command is left in the read buffer,
- * or MAX_COMMANDS[_SERVER] commands were processed.
+ * or MAX_COMMANDS[_SERVER|_SERVICE] commands were processed.
  * When a fatal error occurs, the connection is shut down.
- * @param Idx Index of the connection.
- * @return number of bytes processed.
+ *
+ * @param Idx	Index of the connection.
+ * @returns	Number of bytes processed.
  */
 static unsigned int
 Handle_Buffer(CONN_ID Idx)
@@ -1553,8 +1633,12 @@ Handle_Buffer(CONN_ID Idx)
 
 	/* Servers do get special command limits, so they can process
 	 * all the messages that are required while peering. */
-	if (Client_Type(c) == CLIENT_SERVER)
-		maxcmd = MAX_COMMANDS_SERVER;
+	switch (Client_Type(c)) {
+	    case CLIENT_SERVER:
+		maxcmd = MAX_COMMANDS_SERVER; break;
+	    case CLIENT_SERVICE:
+		maxcmd = MAX_COMMANDS_SERVICE; break;
+	}
 
 	starttime = time(NULL);
 	for (i=0; i < maxcmd; i++) {
@@ -1774,6 +1858,9 @@ Check_Servers(void)
 		}
 
 		/* Okay, try to connect now */
+		Log(LOG_NOTICE,
+		    "Preparing to establish a new server link for \"%s\" ...",
+		    Conf_Server[i].name);
 		Conf_Server[i].lasttry = time_now;
 		Conf_Server[i].conn_id = SERVER_WAIT;
 		assert(Proc_GetPipeFd(&Conf_Server[i].res_stat) < 0);
@@ -1783,6 +1870,12 @@ Check_Servers(void)
 } /* Check_Servers */
 
 
+/**
+ * Establish a new outgoing server connection.
+ *
+ * @param Server	Configuration index of the server.
+ * @param dest		Destination IP address to connect to.
+ */
 static void
 New_Server( int Server , ng_ipaddr_t *dest)
 {
@@ -1798,13 +1891,17 @@ New_Server( int Server , ng_ipaddr_t *dest)
 		return;
 	}
 
-	Log( LOG_INFO, "Establishing connection to \"%s\", %s, port %d ... ",
-			Conf_Server[Server].host, ip_str, Conf_Server[Server].port );
-
 	af_dest = ng_ipaddr_af(dest);
 	new_sock = socket(af_dest, SOCK_STREAM, 0);
+
+	Log(LOG_INFO,
+	    "Establishing connection for \"%s\" to \"%s:%d\" (%s), socket %d ...",
+	    Conf_Server[Server].name, Conf_Server[Server].host,
+	    Conf_Server[Server].port, ip_str, new_sock);
+
 	if (new_sock < 0) {
-		Log( LOG_CRIT, "Can't create socket (af %d) : %s!", af_dest, strerror( errno ));
+		Log(LOG_CRIT, "Can't create socket (af %d): %s!",
+		    af_dest, strerror(errno));
 		return;
 	}
 
@@ -1889,6 +1986,8 @@ New_Server( int Server , ng_ipaddr_t *dest)
 
 /**
  * Initialize connection structure.
+ *
+ * @param Idx	Connection index.
  */
 static void
 Init_Conn_Struct(CONN_ID Idx)
@@ -1904,11 +2003,17 @@ Init_Conn_Struct(CONN_ID Idx)
 } /* Init_Conn_Struct */
 
 
+/**
+ * Initialize options of a new socket.
+ *
+ * For example, we try to set socket options SO_REUSEADDR and IPTOS_LOWDELAY.
+ * Errors shouldn't be fatal and therefore are ignored.
+ *
+ * @param Sock	Socket handle.
+ */
 static bool
 Init_Socket( int Sock )
 {
-	/* Initialize socket (set options) */
-
 	int value;
 
 	if (!io_setnonblock(Sock)) {
@@ -1931,8 +2036,8 @@ Init_Socket( int Sock )
 	LogDebug("Setting IP_TOS on socket %d to IPTOS_LOWDELAY.", Sock);
 	if (setsockopt(Sock, IPPROTO_IP, IP_TOS, &value,
 		       (socklen_t) sizeof(value))) {
-		Log(LOG_ERR, "Can't set socket option IP_TOS: %s!",
-		    strerror(errno));
+		LogDebug("Can't set socket option IP_TOS: %s!",
+			 strerror(errno));
 		/* ignore this error */
 	}
 #endif
@@ -1941,6 +2046,13 @@ Init_Socket( int Sock )
 } /* Init_Socket */
 
 
+/**
+ * Read results of a resolver sub-process and try to initiate a new server
+ * connection.
+ *
+ * @param fd		File descriptor of the pipe to the sub-process.
+ * @param events	(ignored IO specification)
+ */
 static void
 cb_Connect_to_Server(int fd, UNUSED short events)
 {
@@ -1968,8 +2080,11 @@ cb_Connect_to_Server(int fd, UNUSED short events)
 
 	/* Read result from pipe */
 	len = Proc_Read(&Conf_Server[i].res_stat, dest_addrs, sizeof(dest_addrs));
-	if (len == 0)
+	if (len == 0) {
+		/* Error resolving hostname: reset server structure */
+		Conf_Server[i].conn_id = NONE;
 		return;
+	}
 
 	assert((len % sizeof(ng_ipaddr_t)) == 0);
 
@@ -1992,13 +2107,16 @@ cb_Connect_to_Server(int fd, UNUSED short events)
 } /* cb_Read_Forward_Lookup */
 
 
+/**
+ * Read results of a resolver sub-process from the pipe and update the
+ * apropriate connection/client structure(s): hostname and/or IDENT user name.
+ *
+ * @param r_fd		File descriptor of the pipe to the sub-process.
+ * @param events	(ignored IO specification)
+ */
 static void
 cb_Read_Resolver_Result( int r_fd, UNUSED short events )
 {
-	/* Read result of resolver sub-process from pipe and update the
-	 * apropriate connection/client structure(s): hostname and/or
-	 * IDENT user name.*/
-
 	CLIENT *c;
 	CONN_ID i;
 	size_t len;
@@ -2068,9 +2186,14 @@ cb_Read_Resolver_Result( int r_fd, UNUSED short events )
 
 /**
  * Write a "simple" (error) message to a socket.
+ *
  * The message is sent without using the connection write buffers, without
  * compression/encryption, and even without any error reporting. It is
- * designed for error messages of e.g. New_Connection(). */
+ * designed for error messages of e.g. New_Connection().
+ *
+ * @param Sock	Socket handle.
+ * @param Msg	Message string to send.
+ */
 static void
 Simple_Message(int Sock, const char *Msg)
 {
@@ -2099,8 +2222,9 @@ Simple_Message(int Sock, const char *Msg)
  * Get CLIENT structure that belongs to a local connection identified by its
  * index number. Each connection belongs to a client by definition, so it is
  * not required that the caller checks for NULL return values.
- * @param Idx Connection index number
- * @return Pointer to CLIENT structure
+ *
+ * @param Idx	Connection index number.
+ * @returns	Pointer to CLIENT structure.
  */
 GLOBAL CLIENT *
 Conn_GetClient( CONN_ID Idx ) 
@@ -2115,8 +2239,9 @@ Conn_GetClient( CONN_ID Idx )
 
 /**
  * Get PROC_STAT sub-process structure of a connection.
- * @param Idx Connection index number
- * @return PROC_STAT structure
+ *
+ * @param Idx	Connection index number.
+ * @returns	PROC_STAT structure.
  */
 GLOBAL PROC_STAT *
 Conn_GetProcStat(CONN_ID Idx)
@@ -2132,8 +2257,9 @@ Conn_GetProcStat(CONN_ID Idx)
 
 /**
  * Get CONN_ID from file descriptor associated to a subprocess structure.
- * @param fd File descriptor
- * @return CONN_ID or NONE (-1)
+ *
+ * @param fd	File descriptor.
+ * @returns	CONN_ID or NONE (-1).
  */
 GLOBAL CONN_ID
 Conn_GetFromProc(int fd)
@@ -2154,10 +2280,11 @@ Conn_GetFromProc(int fd)
 
 /**
  * Get information about used SSL chiper.
- * @param Idx Connection index number
- * @param buf Buffer for returned information text
- * @param len Size of return buffer "buf"
- * @return true on success, false otherwise
+ *
+ * @param Idx	Connection index number.
+ * @param buf	Buffer for returned information text.
+ * @param len	Size of return buffer "buf".
+ * @returns	true on success, false otherwise.
  */
 GLOBAL bool
 Conn_GetCipherInfo(CONN_ID Idx, char *buf, size_t len)
@@ -2171,8 +2298,9 @@ Conn_GetCipherInfo(CONN_ID Idx, char *buf, size_t len)
 
 /**
  * Check if a connection is SSL-enabled or not.
- * @param Idx Connection index number
- * @return true if connection is SSL-enabled, false otherwise.
+ *
+ * @param Idx	Connection index number.
+ * @return	true if connection is SSL-enabled, false otherwise.
  */
 GLOBAL bool
 Conn_UsesSSL(CONN_ID Idx)
@@ -2188,6 +2316,9 @@ Conn_UsesSSL(CONN_ID Idx)
 
 #ifdef DEBUG
 
+/**
+ * Dump internal state of the "connection module".
+ */
 GLOBAL void
 Conn_DebugDump(void)
 {