/* * ngIRCd -- The Next Generation IRC Daemon * Copyright (c)2001-2007 Alexander Barton (alex@barton.de) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * 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 "io.h" static char UNUSED id[] = "$Id: conn.c,v 1.213 2007/10/25 11:01:19 fw Exp $"; #include "imp.h" #include #ifdef PROTOTYPES # include #else # include #endif #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_NETINET_IP_H # include #endif #ifdef HAVE_ARPA_INET_H # include #else # define PF_INET AF_INET #endif #ifdef HAVE_STDINT_H # include /* e.g. for Mac OS X */ #endif #ifdef TCPWRAP # include /* for TCP Wrappers */ #endif #include "array.h" #include "defines.h" #include "resolve.h" #include "exp.h" #include "conn.h" #include "imp.h" #include "ngircd.h" #include "client.h" #include "conf.h" #include "conn-zip.h" #include "conn-func.h" #include "log.h" #include "parse.h" #include "tool.h" #ifdef ZEROCONF # include "rendezvous.h" #endif #include "exp.h" #define SERVER_WAIT (NONE - 1) static bool Handle_Write PARAMS(( CONN_ID Idx )); static bool Conn_Write PARAMS(( CONN_ID Idx, char *Data, size_t Len )); static int New_Connection PARAMS(( int Sock )); static CONN_ID Socket2Index PARAMS(( int Sock )); static void Read_Request PARAMS(( CONN_ID Idx )); static bool Handle_Buffer PARAMS(( CONN_ID Idx )); static void Check_Connections PARAMS(( void )); static void Check_Servers PARAMS(( void )); static void Init_Conn_Struct PARAMS(( CONN_ID Idx )); static bool Init_Socket PARAMS(( int Sock )); static void New_Server PARAMS(( int Server )); static void Simple_Message PARAMS(( int Sock, const char *Msg )); static int Count_Connections PARAMS(( struct sockaddr_in addr )); static int NewListener PARAMS(( const UINT16 Port )); static array My_Listeners; static array My_ConnArray; #ifdef TCPWRAP int allow_severity = LOG_INFO; int deny_severity = LOG_ERR; #endif static void server_login PARAMS((CONN_ID idx)); static void cb_Read_Resolver_Result PARAMS(( int sock, UNUSED short what)); static void cb_Connect_to_Server PARAMS(( int sock, UNUSED short what)); static void cb_clientserver PARAMS((int sock, short what)); static void cb_listen(int sock, short irrelevant) { (void) irrelevant; New_Connection( sock ); } static void cb_connserver(int sock, UNUSED short what) { int res, err; socklen_t sock_len; CONN_ID idx = Socket2Index( sock ); if (idx <= NONE) { LogDebug("cb_connserver wants to write on unknown socket?!"); io_close(sock); return; } assert( what & IO_WANTWRITE); /* connect() finished, get result. */ sock_len = sizeof( err ); res = getsockopt( My_Connections[idx].sock, SOL_SOCKET, SO_ERROR, &err, &sock_len ); assert( sock_len == sizeof( err )); /* Error while connecting? */ if ((res != 0) || (err != 0)) { if (res != 0) Log(LOG_CRIT, "getsockopt (connection %d): %s!", idx, strerror(errno)); else Log(LOG_CRIT, "Can't connect socket to \"%s:%d\" (connection %d): %s!", My_Connections[idx].host, Conf_Server[Conf_GetServer(idx)].port, idx, strerror(err)); Conn_Close(idx, "Can't connect!", NULL, false); return; } Conn_OPTION_DEL( &My_Connections[idx], CONN_ISCONNECTING ); server_login(idx); } 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 ); io_event_setcb( My_Connections[idx].sock, cb_clientserver); io_event_add( My_Connections[idx].sock, IO_WANTREAD|IO_WANTWRITE); /* Send PASS and SERVER command to peer */ Conn_WriteStr( idx, "PASS %s %s", Conf_Server[Conf_GetServer( idx )].pwd_out, NGIRCd_ProtoID ); Conn_WriteStr( idx, "SERVER %s :%s", Conf_ServerName, Conf_ServerInfo ); } static void cb_clientserver(int sock, short what) { CONN_ID idx = Socket2Index( sock ); if (idx <= NONE) { #ifdef DEBUG Log(LOG_WARNING, "WTF: cb_clientserver wants to write on unknown socket?!"); #endif io_close(sock); return; } if (what & IO_WANTREAD) Read_Request( idx ); if (what & IO_WANTWRITE) Handle_Write( idx ); } GLOBAL void Conn_Init( void ) { /* Modul initialisieren: statische Strukturen "ausnullen". */ CONN_ID i; /* Speicher fuer Verbindungs-Pool anfordern */ Pool_Size = CONNECTION_POOL; if( Conf_MaxConnections > 0 ) { /* konfiguriertes Limit beachten */ if( Pool_Size > Conf_MaxConnections ) Pool_Size = Conf_MaxConnections; } if (!array_alloc(&My_ConnArray, sizeof(CONNECTION), (size_t)Pool_Size)) { Log( LOG_EMERG, "Can't allocate memory! [Conn_Init]" ); exit( 1 ); } /* FIXME: My_Connetions/Pool_Size is needed by other parts of the * code; remove them! */ My_Connections = (CONNECTION*) array_start(&My_ConnArray); LogDebug("Allocated connection pool for %d items (%ld bytes).", array_length(&My_ConnArray, sizeof( CONNECTION )), array_bytes(&My_ConnArray)); assert( array_length(&My_ConnArray, sizeof( CONNECTION )) >= (size_t) Pool_Size); array_free( &My_Listeners ); /* Connection-Struktur initialisieren */ for( i = 0; i < Pool_Size; i++ ) Init_Conn_Struct( i ); /* Global write counter */ WCounter = 0; } /* Conn_Init */ GLOBAL void Conn_Exit( void ) { /* Modul abmelden: alle noch offenen Connections * schliessen und freigeben. */ CONN_ID idx; LogDebug("Shutting down all connections ..." ); Conn_ExitListeners(); /* Sockets schliessen */ for( idx = 0; idx < Pool_Size; idx++ ) { if( My_Connections[idx].sock > NONE ) { Conn_Close( idx, NULL, NGIRCd_SignalRestart ? "Server going down (restarting)":"Server going down", true ); } } array_free(&My_ConnArray); My_Connections = NULL; Pool_Size = 0; io_library_shutdown(); } /* Conn_Exit */ static unsigned int ports_initlisteners(array *a, void (*func)(int,short)) { unsigned int created = 0; size_t len; int fd; UINT16 *port; len = array_length(a, sizeof (UINT16)); port = array_start(a); while(len--) { fd = NewListener( *port ); if (fd < 0) { port++; continue; } if (!io_event_create( fd, IO_WANTREAD, func )) { Log( LOG_ERR, "io_event_create(): Could not add listening fd %d (port %u): %s!", fd, (unsigned int) *port, strerror(errno)); close(fd); port++; continue; } created++; port++; } return created; } GLOBAL unsigned int Conn_InitListeners( void ) { /* Initialize ports on which the server should accept connections */ unsigned int created; if (!io_library_init(CONNECTION_POOL)) { Log(LOG_EMERG, "Cannot initialize IO routines: %s", strerror(errno)); return -1; } created = ports_initlisteners(&Conf_ListenPorts, cb_listen); return created; } /* Conn_InitListeners */ 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, "Shutting down all listening sockets (%d total)...", arraylen ); fd = array_start(&My_Listeners); while(arraylen--) { assert(fd != NULL); assert(*fd >= 0); io_close(*fd); LogDebug("Listening socket %d closed.", *fd ); fd++; } array_free(&My_Listeners); } /* Conn_ExitListeners */ /* return new listening port file descriptor or -1 on failure */ static int NewListener( const UINT16 Port ) { /* Create new listening socket on specified port */ struct sockaddr_in addr; struct in_addr inaddr; int sock; #ifdef ZEROCONF char name[CLIENT_ID_LEN], *info; #endif /* Server-"Listen"-Socket initialisieren */ memset( &addr, 0, sizeof( addr )); memset( &inaddr, 0, sizeof( inaddr )); addr.sin_family = (sa_family_t)AF_INET; addr.sin_port = htons( Port ); if( Conf_ListenAddress[0] ) { #ifdef HAVE_INET_ATON if( inet_aton( Conf_ListenAddress, &inaddr ) == 0 ) #else inaddr.s_addr = inet_addr( Conf_ListenAddress ); if( inaddr.s_addr == (unsigned)-1 ) #endif { Log( LOG_CRIT, "Can't listen on %s:%u: can't convert ip address %s!", Conf_ListenAddress, Port, Conf_ListenAddress ); return -1; } } else inaddr.s_addr = htonl( INADDR_ANY ); addr.sin_addr = inaddr; sock = socket( PF_INET, SOCK_STREAM, 0); if( sock < 0 ) { Log( LOG_CRIT, "Can't create socket: %s!", strerror( errno )); return -1; } if( ! Init_Socket( sock )) return -1; if (bind(sock, (struct sockaddr *)&addr, (socklen_t)sizeof(addr)) != 0) { Log( LOG_CRIT, "Can't bind socket (port %d) : %s!", Port, strerror( errno )); close( sock ); return -1; } if( listen( sock, 10 ) != 0 ) { Log( LOG_CRIT, "Can't listen on socket: %s!", strerror( errno )); close( sock ); return -1; } /* keep fd in list so we can close it when ngircd restarts/shuts down */ if (!array_catb( &My_Listeners,(char*) &sock, sizeof(int) )) { Log( LOG_CRIT, "Can't add socket to My_Listeners array: %s!", strerror( errno )); close( sock ); return -1; } if( Conf_ListenAddress[0]) Log( LOG_INFO, "Now listening on %s:%d (socket %d).", Conf_ListenAddress, Port, sock ); else Log( LOG_INFO, "Now listening on 0.0.0.0:%d (socket %d).", 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 return sock; } /* NewListener */ GLOBAL void Conn_Handler( void ) { /* "Main Loop.": Loop until a signal (for shutdown or restart) arrives. * Call io_dispatch() to check for read/writeable sockets every second * Wait for status change on pending connections (e.g: when the hostname has been resolved) * check for penalty/timeouts * handle input buffers */ int i; unsigned int wdatalen; struct timeval tv; time_t t; bool timeout; while(( ! NGIRCd_SignalQuit ) && ( ! NGIRCd_SignalRestart )) { timeout = true; #ifdef ZEROCONF Rendezvous_Handler( ); #endif /* Should the configuration be reloaded? */ if (NGIRCd_SignalRehash) { NGIRCd_Rehash( ); } /* Check configured servers and established links */ Check_Servers( ); Check_Connections( ); t = time( NULL ); /* noch volle Lese-Buffer suchen */ for( i = 0; i < Pool_Size; i++ ) { if(( My_Connections[i].sock > NONE ) && ( array_bytes(&My_Connections[i].rbuf) > 0 ) && ( My_Connections[i].delaytime < t )) { /* Kann aus dem Buffer noch ein Befehl extrahiert werden? */ if (Handle_Buffer( i )) timeout = false; } } /* noch volle Schreib-Puffer suchen */ for( i = 0; i < Pool_Size; i++ ) { if ( My_Connections[i].sock <= NONE ) continue; wdatalen = (unsigned int)array_bytes(&My_Connections[i].wbuf); #ifdef ZLIB if (( wdatalen > 0 ) || ( array_bytes(&My_Connections[i].zip.wbuf)> 0 )) #else if ( wdatalen > 0 ) #endif { /* Socket der Verbindung in Set aufnehmen */ io_event_add( My_Connections[i].sock, IO_WANTWRITE ); } } /* von welchen Sockets koennte gelesen werden? */ for (i = 0; i < Pool_Size; i++ ) { if ( My_Connections[i].sock <= NONE ) continue; if (Resolve_INPROGRESS(&My_Connections[i].res_stat)) { /* wait for completion of Resolver Sub-Process */ io_event_del( My_Connections[i].sock, IO_WANTREAD ); continue; } if ( Conn_OPTION_ISSET( &My_Connections[i], CONN_ISCONNECTING )) continue; /* wait for completion of connect() */ if( My_Connections[i].delaytime > t ) { /* Fuer die Verbindung ist eine "Penalty-Zeit" gesetzt */ io_event_del( My_Connections[i].sock, IO_WANTREAD ); continue; } io_event_add( My_Connections[i].sock, IO_WANTREAD ); } /* (re-)set timeout - tv_sec/usec are undefined after io_dispatch() returns */ tv.tv_usec = 0; tv.tv_sec = timeout ? 1 : 0; /* wait for activity */ i = io_dispatch( &tv ); if (i == -1 && errno != EINTR ) { Log(LOG_EMERG, "Conn_Handler(): io_dispatch(): %s!", strerror(errno)); Log(LOG_ALERT, "%s exiting due to fatal errors!", PACKAGE_NAME); exit( 1 ); } } if( NGIRCd_SignalQuit ) Log( LOG_NOTICE|LOG_snotice, "Server going down NOW!" ); else if( NGIRCd_SignalRestart ) Log( LOG_NOTICE|LOG_snotice, "Server restarting NOW!" ); } /* Conn_Handler */ /** * 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. */ #ifdef PROTOTYPES GLOBAL bool Conn_WriteStr( CONN_ID Idx, char *Format, ... ) #else GLOBAL bool Conn_WriteStr( Idx, Format, va_alist ) CONN_ID Idx; char *Format; va_dcl #endif { char buffer[COMMAND_LEN]; size_t len; bool ok; va_list ap; assert( Idx > NONE ); assert( Format != NULL ); #ifdef PROTOTYPES va_start( ap, Format ); #else va_start( ap ); #endif if (vsnprintf( buffer, COMMAND_LEN - 2, Format, ap ) >= COMMAND_LEN - 2 ) { /* * The string that should be written to the socket is longer * than the allowed size of COMMAND_LEN bytes (including both * the CR and LF characters). This can be caused by the * IRC_WriteXXX() functions when the prefix of this server had * to be added to an already "quite long" command line which * has been received from a regular IRC client, for example. * * We are not allowed to send such "oversized" messages to * other servers and clients, see RFC 2812 2.3 and 2813 3.3 * ("these messages SHALL NOT exceed 512 characters in length, * counting all characters including the trailing CR-LF"). * * So we have a big problem here: we should send more bytes * to the network than we are allowed to and we don't know * the originator (any more). The "old" behaviour of blaming * the receiver ("next hop") is a bad idea (it could be just * an other server only routing the message!), so the only * option left is to shorten the string and to hope that the * result is still somewhat useful ... * -alex- */ strcpy (buffer + sizeof(buffer) - strlen(CUT_TXTSUFFIX) - 2 - 1, CUT_TXTSUFFIX); } #ifdef SNIFFER if (NGIRCd_Sniffer) Log(LOG_DEBUG, " -> connection %d: '%s'.", Idx, buffer); #endif len = strlcat( buffer, "\r\n", sizeof( buffer )); ok = Conn_Write(Idx, buffer, len); My_Connections[Idx].msg_out++; va_end( ap ); return ok; } /* Conn_WriteStr */ /** * 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. */ static bool Conn_Write( CONN_ID Idx, char *Data, size_t Len ) { CLIENT *c; size_t writebuf_limit = WRITEBUFFER_LEN; assert( Idx > NONE ); assert( Data != NULL ); assert( Len > 0 ); c = Conn_GetClient(Idx); assert( c != NULL); /* Servers do get special write buffer limits, so they can generate * all the messages that are required while peering. */ if (Client_Type(c) == CLIENT_SERVER) writebuf_limit = WRITEBUFFER_SLINK_LEN; /* Is the socket still open? A previous call to Conn_Write() * may have closed the connection due to a fatal error. * In this case it is sufficient to return an error, as well. */ if( My_Connections[Idx].sock <= NONE ) { LogDebug("Skipped write on closed socket (connection %d).", Idx); return false; } #ifdef ZLIB if ( Conn_OPTION_ISSET( &My_Connections[Idx], CONN_ZIP )) { /* Compressed link: * Zip_Buffer() does all the dirty work for us: it flushes * the (pre-)compression buffers if required and handles * all error conditions. */ if (!Zip_Buffer(Idx, Data, Len)) return false; } else #endif { /* Uncompressed link: * Check if outbound buffer has enough space for the data. */ if (array_bytes(&My_Connections[Idx].wbuf) + Len >= writebuf_limit) { /* Buffer is full, flush it. Handle_Write deals with * low-level errors, if any. */ if (!Handle_Write(Idx)) return false; } /* When the write buffer is still too big after flushing it, * the connection will be killed. */ if (array_bytes(&My_Connections[Idx].wbuf) + Len >= writebuf_limit) { Log(LOG_NOTICE, "Write buffer overflow (connection %d, size %lu byte)!", Idx, (unsigned long)array_bytes(&My_Connections[Idx].wbuf)); Conn_Close(Idx, "Write buffer overflow!", NULL, false); return false; } /* Copy data to write buffer */ if (!array_catb(&My_Connections[Idx].wbuf, Data, Len)) return false; My_Connections[Idx].bytes_out += Len; } /* Adjust global write counter */ WCounter += Len; return true; } /* Conn_Write */ GLOBAL void Conn_Close( CONN_ID Idx, char *LogMsg, char *FwdMsg, bool InformClient ) { /* Close connection. Open pipes of asyncronous resolver * sub-processes are closed down. */ CLIENT *c; char *txt; double in_k, out_k; #ifdef ZLIB double in_z_k, out_z_k; int in_p, out_p; #endif assert( Idx > NONE ); /* Is this link already shutting down? */ if( Conn_OPTION_ISSET( &My_Connections[Idx], CONN_ISCLOSING )) { /* Conn_Close() has been called recursively for this link; * probabe reason: Handle_Write() failed -- see below. */ LogDebug("Recursive request to close connection: %d", Idx ); return; } assert( My_Connections[Idx].sock > NONE ); /* Mark link as "closing" */ Conn_OPTION_ADD( &My_Connections[Idx], CONN_ISCLOSING ); if (LogMsg) txt = LogMsg; else txt = FwdMsg; if (! txt) txt = "Reason unknown"; Log(LOG_INFO, "Shutting down connection %d (%s) with %s:%d ...", Idx, LogMsg ? LogMsg : FwdMsg, My_Connections[Idx].host, ntohs(My_Connections[Idx].addr.sin_port)); /* Search client, if any */ c = Conn_GetClient( Idx ); /* Should the client be informed? */ if (InformClient) { #ifndef STRICT_RFC /* Send statistics to client if registered as user: */ if ((c != NULL) && (Client_Type(c) == CLIENT_USER)) { Conn_WriteStr( Idx, ":%s NOTICE %s :%sConnection statistics: client %.1f kb, server %.1f kb.", Client_ID(Client_ThisServer()), Client_ID(c), NOTICE_TXTPREFIX, (double)My_Connections[Idx].bytes_in / 1024, (double)My_Connections[Idx].bytes_out / 1024); } #endif /* Send ERROR to client (see RFC!) */ if (FwdMsg) Conn_WriteStr(Idx, "ERROR :%s", FwdMsg); else Conn_WriteStr(Idx, "ERROR :Closing connection."); } /* Try to write out the write buffer. Note: Handle_Write() eventually * removes the CLIENT structure associated with this connection if an * error occurs! So we have to re-check if there is still an valid * CLIENT structure after calling Handle_Write() ...*/ (void)Handle_Write( Idx ); /* Search client, if any (re-check!) */ c = Conn_GetClient( Idx ); /* Shut down socket */ if (! io_close(My_Connections[Idx].sock)) { /* Oops, we can't close the socket!? This is ... ugly! */ Log(LOG_CRIT, "Error closing connection %d (socket %d) with %s:%d - %s! (ignored)", Idx, My_Connections[Idx].sock, My_Connections[Idx].host, ntohs(My_Connections[Idx].addr.sin_port), strerror(errno)); } /* Mark socket as invalid: */ My_Connections[Idx].sock = NONE; /* If there is still a client, unregister it now */ if (c) Client_Destroy(c, LogMsg, FwdMsg, true); /* Calculate statistics and log information */ in_k = (double)My_Connections[Idx].bytes_in / 1024; out_k = (double)My_Connections[Idx].bytes_out / 1024; #ifdef ZLIB if (Conn_OPTION_ISSET( &My_Connections[Idx], CONN_ZIP)) { in_z_k = (double)My_Connections[Idx].zip.bytes_in / 1024; out_z_k = (double)My_Connections[Idx].zip.bytes_out / 1024; /* Make sure that no division by zero can occur during * the calculation of in_p and out_p: in_z_k and out_z_k * are non-zero, that's guaranteed by the protocol until * compression can be enabled. */ if (! in_z_k) in_z_k = in_k; if (! out_z_k) out_z_k = out_k; in_p = (int)(( in_k * 100 ) / in_z_k ); out_p = (int)(( out_k * 100 ) / out_z_k ); Log(LOG_INFO, "Connection %d with %s:%d closed (in: %.1fk/%.1fk/%d%%, out: %.1fk/%.1fk/%d%%).", Idx, My_Connections[Idx].host, ntohs(My_Connections[Idx].addr.sin_port), in_k, in_z_k, in_p, out_k, out_z_k, out_p); } else #endif { Log(LOG_INFO, "Connection %d with %s:%d closed (in: %.1fk, out: %.1fk).", Idx, My_Connections[Idx].host, ntohs(My_Connections[Idx].addr.sin_port), in_k, out_k); } /* cancel running resolver */ if (Resolve_INPROGRESS(&My_Connections[Idx].res_stat)) Resolve_Shutdown(&My_Connections[Idx].res_stat); /* Servers: Modify time of next connect attempt? */ Conf_UnsetServer( Idx ); #ifdef ZLIB /* Clean up zlib, if link was compressed */ if ( Conn_OPTION_ISSET( &My_Connections[Idx], CONN_ZIP )) { inflateEnd( &My_Connections[Idx].zip.in ); deflateEnd( &My_Connections[Idx].zip.out ); array_free(&My_Connections[Idx].zip.rbuf); array_free(&My_Connections[Idx].zip.wbuf); } #endif array_free(&My_Connections[Idx].rbuf); array_free(&My_Connections[Idx].wbuf); /* Clean up connection structure (=free it) */ Init_Conn_Struct( Idx ); LogDebug("Shutdown of connection %d completed.", Idx ); } /* Conn_Close */ GLOBAL void Conn_SyncServerStruct( void ) { /* Synchronize server structures (connection IDs): * connections <-> configuration */ CLIENT *client; CONN_ID i; int c; for( i = 0; i < Pool_Size; i++ ) { /* Established connection? */ if (My_Connections[i].sock < 0) continue; /* Server connection? */ client = Conn_GetClient( i ); if(( ! client ) || ( Client_Type( client ) != CLIENT_SERVER )) continue; for( c = 0; c < MAX_SERVERS; c++ ) { /* Configured server? */ if( ! Conf_Server[c].host[0] ) continue; /* Duplicate? */ if( strcmp( Conf_Server[c].name, Client_ID( client )) == 0 ) Conf_Server[c].conn_id = i; } } } /* SyncServerStruct */ /** * Send out data of write buffer; connect new sockets. */ static bool Handle_Write( CONN_ID Idx ) { ssize_t len; size_t wdatalen; assert( Idx > NONE ); if ( My_Connections[Idx].sock < 0 ) { LogDebug("Handle_Write() on closed socket, connection %d", Idx); return false; } assert( My_Connections[Idx].sock > NONE ); wdatalen = array_bytes(&My_Connections[Idx].wbuf ); #ifdef ZLIB if (wdatalen == 0) { /* Write buffer is empty, so we try to flush the compression * buffer and get some data to work with from there :-) */ if (!Zip_Flush(Idx)) return false; /* Now the write buffer most probably has changed: */ wdatalen = array_bytes(&My_Connections[Idx].wbuf); } #endif if (wdatalen == 0) { /* Still no data, fine. */ io_event_del(My_Connections[Idx].sock, IO_WANTWRITE ); return true; } LogDebug ("Handle_Write() called for connection %d, %ld bytes pending ...", Idx, wdatalen); len = write(My_Connections[Idx].sock, array_start(&My_Connections[Idx].wbuf), wdatalen ); if( len < 0 ) { if (errno == EAGAIN || errno == EINTR) return true; Log(LOG_ERR, "Write error on connection %d (socket %d): %s!", Idx, My_Connections[Idx].sock, strerror(errno)); Conn_Close(Idx, "Write error!", NULL, false); return false; } /* move any data not yet written to beginning */ array_moveleft(&My_Connections[Idx].wbuf, 1, (size_t)len); return true; } /* Handle_Write */ static int New_Connection( int Sock ) { /* Neue Client-Verbindung von Listen-Socket annehmen und * CLIENT-Struktur anlegen. */ #ifdef TCPWRAP struct request_info req; #endif struct sockaddr_in new_addr; int new_sock, new_sock_len, new_Pool_Size; CLIENT *c; long cnt; assert( Sock > NONE ); /* Connection auf Listen-Socket annehmen */ new_sock_len = (int)sizeof new_addr; new_sock = accept(Sock, (struct sockaddr *)&new_addr, (socklen_t *)&new_sock_len); if (new_sock < 0) { Log(LOG_CRIT, "Can't accept connection: %s!", strerror(errno)); return -1; } #ifdef TCPWRAP /* Validate socket using TCP Wrappers */ request_init( &req, RQ_DAEMON, PACKAGE_NAME, RQ_FILE, new_sock, RQ_CLIENT_SIN, &new_addr, NULL ); fromhost(&req); if( ! hosts_access( &req )) { /* Access denied! */ Log( deny_severity, "Refused connection from %s (by TCP Wrappers)!", inet_ntoa( new_addr.sin_addr )); Simple_Message( new_sock, "ERROR :Connection refused" ); close( new_sock ); return -1; } #endif /* Socket initialisieren */ if (!Init_Socket( new_sock )) return -1; /* Check IP-based connection limit */ cnt = Count_Connections( new_addr ); if(( Conf_MaxConnectionsIP > 0 ) && ( cnt >= Conf_MaxConnectionsIP )) { /* Access denied, too many connections from this IP address! */ Log( LOG_ERR, "Refused connection from %s: too may connections (%ld) from this IP address!", inet_ntoa( new_addr.sin_addr ), cnt); Simple_Message( new_sock, "ERROR :Connection refused, too many connections from your IP address!" ); close( new_sock ); return -1; } if( new_sock >= Pool_Size ) { new_Pool_Size = new_sock + 1; /* No free Connection Structures, check if we may accept further connections */ if ((( Conf_MaxConnections > 0) && Pool_Size >= Conf_MaxConnections) || (new_Pool_Size < Pool_Size)) { Log( LOG_ALERT, "Can't accept connection: limit (%d) reached!", Pool_Size ); Simple_Message( new_sock, "ERROR :Connection limit reached" ); close( new_sock ); return -1; } if (!array_alloc(&My_ConnArray, sizeof(CONNECTION), (size_t)new_sock)) { Log( LOG_EMERG, "Can't allocate memory! [New_Connection]" ); Simple_Message( new_sock, "ERROR: Internal error" ); close( new_sock ); return -1; } LogDebug("Bumped connection pool to %ld items (internal: %ld items, %ld bytes)", new_sock, array_length(&My_ConnArray, sizeof(CONNECTION)), array_bytes(&My_ConnArray)); /* Adjust pointer to new block */ My_Connections = array_start(&My_ConnArray); while (Pool_Size < new_Pool_Size) Init_Conn_Struct(Pool_Size++); } /* register callback */ if (!io_event_create( new_sock, IO_WANTREAD, cb_clientserver)) { Log(LOG_ALERT, "Can't accept connection: io_event_create failed!"); Simple_Message(new_sock, "ERROR :Internal error"); close(new_sock); return -1; } c = Client_NewLocal( new_sock, inet_ntoa( new_addr.sin_addr ), CLIENT_UNKNOWN, false ); if( ! c ) { Log(LOG_ALERT, "Can't accept connection: can't create client structure!"); Simple_Message(new_sock, "ERROR :Internal error"); io_close(new_sock); return -1; } Init_Conn_Struct( new_sock ); My_Connections[new_sock].sock = new_sock; My_Connections[new_sock].addr = new_addr; My_Connections[new_sock].client = c; Log( LOG_INFO, "Accepted connection %d from %s:%d on socket %d.", new_sock, inet_ntoa( new_addr.sin_addr ), ntohs( new_addr.sin_port), Sock ); /* Hostnamen ermitteln */ strlcpy( My_Connections[new_sock].host, inet_ntoa( new_addr.sin_addr ), sizeof( My_Connections[new_sock].host )); Client_SetHostname( c, My_Connections[new_sock].host ); if (!Conf_NoDNS) Resolve_Addr(&My_Connections[new_sock].res_stat, &new_addr, My_Connections[new_sock].sock, cb_Read_Resolver_Result); Conn_SetPenalty(new_sock, 4); return new_sock; } /* New_Connection */ static CONN_ID Socket2Index( int Sock ) { /* zum Socket passende Connection suchen */ assert( Sock >= 0 ); if( Sock >= Pool_Size || My_Connections[Sock].sock != Sock ) { /* die Connection wurde vermutlich (wegen eines * Fehlers) bereits wieder abgebaut ... */ LogDebug("Socket2Index: can't get connection for socket %d!", Sock); return NONE; } return Sock; } /* Socket2Index */ /** * Read data from the network to the read buffer. If an error occures, * the socket of this connection will be shut down. */ static void Read_Request( CONN_ID Idx ) { ssize_t len; char readbuf[READBUFFER_LEN]; CLIENT *c; assert( Idx > NONE ); assert( My_Connections[Idx].sock > NONE ); #ifdef ZLIB if ((array_bytes(&My_Connections[Idx].rbuf) >= READBUFFER_LEN) || (array_bytes(&My_Connections[Idx].zip.rbuf) >= READBUFFER_LEN)) #else if (array_bytes(&My_Connections[Idx].rbuf) >= READBUFFER_LEN) #endif { /* Read buffer is full */ Log(LOG_ERR, "Receive buffer overflow (connection %d): %d bytes!", Idx, array_bytes(&My_Connections[Idx].rbuf)); Conn_Close( Idx, "Receive buffer overflow!", NULL, false ); return; } len = read(My_Connections[Idx].sock, readbuf, sizeof(readbuf)); if (len == 0) { Log(LOG_INFO, "%s:%d (%s) is closing the connection ...", My_Connections[Idx].host, ntohs(My_Connections[Idx].addr.sin_port), inet_ntoa( My_Connections[Idx].addr.sin_addr)); Conn_Close(Idx, "Socket closed!", "Client closed connection", false); return; } if (len < 0) { if( errno == EAGAIN ) return; Log(LOG_ERR, "Read error on connection %d (socket %d): %s!", Idx, My_Connections[Idx].sock, strerror(errno)); Conn_Close(Idx, "Read error!", "Client closed connection", false); return; } #ifdef ZLIB if (Conn_OPTION_ISSET(&My_Connections[Idx], CONN_ZIP)) { if (!array_catb(&My_Connections[Idx].zip.rbuf, readbuf, (size_t) len)) { Log(LOG_ERR, "Could not append recieved data to zip input buffer (connn %d): %d bytes!", Idx, len); Conn_Close(Idx, "Receive buffer overflow!", NULL, false); return; } } else #endif { if (!array_catb( &My_Connections[Idx].rbuf, readbuf, len)) { Log( LOG_ERR, "Could not append recieved data to input buffer (connn %d): %d bytes!", Idx, len ); Conn_Close( Idx, "Receive buffer overflow!", NULL, false ); } } /* Update connection statistics */ My_Connections[Idx].bytes_in += len; /* 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(). * Set "lastping", too, so we can handle time shifts backwards ... */ c = Conn_GetClient(Idx); if (c && (Client_Type(c) == CLIENT_USER || Client_Type(c) == CLIENT_SERVER || Client_Type(c) == CLIENT_SERVICE)) { My_Connections[Idx].lastdata = time(NULL); My_Connections[Idx].lastping = My_Connections[Idx].lastdata; } /* Look at the data in the (read-) buffer of this connection */ Handle_Buffer(Idx); } /* Read_Request */ static bool Handle_Buffer( CONN_ID Idx ) { /* Handle Data in Connections Read-Buffer. * Return true if a reuqest was handled, false otherwise (also returned on errors). */ #ifndef STRICT_RFC char *ptr1, *ptr2; #endif char *ptr; size_t len, delta; bool result; time_t starttime; #ifdef ZLIB bool old_z; #endif starttime = time(NULL); result = false; for (;;) { /* Check penalty */ if( My_Connections[Idx].delaytime > starttime) return result; #ifdef ZLIB /* unpack compressed data */ if ( Conn_OPTION_ISSET( &My_Connections[Idx], CONN_ZIP )) if( ! Unzip_Buffer( Idx )) return false; #endif if (0 == array_bytes(&My_Connections[Idx].rbuf)) break; if (!array_cat0_temporary(&My_Connections[Idx].rbuf)) /* make sure buf is NULL terminated */ return false; /* A Complete Request end with CR+LF, see RFC 2812. */ ptr = strstr( array_start(&My_Connections[Idx].rbuf), "\r\n" ); if( ptr ) delta = 2; /* complete request */ #ifndef STRICT_RFC else { /* Check for non-RFC-compliant request (only CR or LF)? Unfortunately, * there are quite a few clients that do this (incl. "mIRC" :-( */ ptr1 = strchr( array_start(&My_Connections[Idx].rbuf), '\r' ); ptr2 = strchr( array_start(&My_Connections[Idx].rbuf), '\n' ); delta = 1; if( ptr1 && ptr2 ) ptr = ptr1 > ptr2 ? ptr2 : ptr1; else if( ptr1 ) ptr = ptr1; else if( ptr2 ) ptr = ptr2; } #endif if( ! ptr ) break; /* End of request found */ *ptr = '\0'; len = ( ptr - (char*) array_start(&My_Connections[Idx].rbuf)) + delta; if( len > ( COMMAND_LEN - 1 )) { /* Request must not exceed 512 chars (incl. CR+LF!), see * RFC 2812. Disconnect Client if this happens. */ Log( LOG_ERR, "Request too long (connection %d): %d bytes (max. %d expected)!", Idx, array_bytes(&My_Connections[Idx].rbuf), COMMAND_LEN - 1 ); Conn_Close( Idx, NULL, "Request too long", true ); return false; } if (len <= 2) { /* request was empty (only '\r\n') */ array_moveleft(&My_Connections[Idx].rbuf, 1, delta); /* delta is either 1 or 2 */ break; } #ifdef ZLIB /* remember if stream is already compressed */ old_z = My_Connections[Idx].options & CONN_ZIP; #endif My_Connections[Idx].msg_in++; if (!Parse_Request(Idx, (char*)array_start(&My_Connections[Idx].rbuf) )) return false; result = true; array_moveleft(&My_Connections[Idx].rbuf, 1, len); LogDebug("Connection %d: %d bytes left in read buffer.", Idx, array_bytes(&My_Connections[Idx].rbuf)); #ifdef ZLIB if(( ! old_z ) && ( My_Connections[Idx].options & CONN_ZIP ) && ( array_bytes(&My_Connections[Idx].rbuf) > 0 )) { /* The last Command activated Socket-Compression. * Data that was read after that needs to be copied to Unzip-buf * for decompression */ if (!array_copy( &My_Connections[Idx].zip.rbuf, &My_Connections[Idx].rbuf )) return false; array_trunc(&My_Connections[Idx].rbuf); LogDebug("Moved already received data (%u bytes) to uncompression buffer.", array_bytes(&My_Connections[Idx].zip.rbuf)); } #endif /* ZLIB */ } return result; } /* Handle_Buffer */ static void Check_Connections(void) { /* check if connections are alive. if not, play PING-PONG first. * if this doesn't help either, disconnect client. */ CLIENT *c; CONN_ID i; for (i = 0; i < Pool_Size; i++) { if (My_Connections[i].sock < 0) continue; c = Conn_GetClient(i); if (c && ((Client_Type(c) == CLIENT_USER) || (Client_Type(c) == CLIENT_SERVER) || (Client_Type(c) == CLIENT_SERVICE))) { /* connected User, Server or Service */ if (My_Connections[i].lastping > My_Connections[i].lastdata) { /* We already sent a ping */ if (My_Connections[i].lastping < time(NULL) - Conf_PongTimeout) { /* Timeout */ LogDebug ("Connection %d: Ping timeout: %d seconds.", i, Conf_PongTimeout); Conn_Close(i, NULL, "Ping timeout", true); } } else if (My_Connections[i].lastdata < time(NULL) - Conf_PingTimeout) { /* We need to send a PING ... */ LogDebug("Connection %d: sending PING ...", i); My_Connections[i].lastping = time(NULL); Conn_WriteStr(i, "PING :%s", Client_ID(Client_ThisServer())); } } else { /* The connection is not fully established yet, so * we don't do the PING-PONG game here but instead * disconnect the client after "a short time" if it's * still not registered. */ if (My_Connections[i].lastdata < time(NULL) - Conf_PongTimeout) { LogDebug ("Unregistered connection %d timed out ...", i); Conn_Close(i, NULL, "Timeout", false); } } } } /* Check_Connections */ static void Check_Servers( void ) { /* Check if we can establish further server links */ int i, n; time_t time_now; /* Check all configured servers */ for( i = 0; i < MAX_SERVERS; i++ ) { /* Valid outgoing server which isn't already connected or disabled? */ if(( ! Conf_Server[i].host[0] ) || ( ! Conf_Server[i].port > 0 ) || ( Conf_Server[i].conn_id > NONE ) || ( Conf_Server[i].flags & CONF_SFLAG_DISABLED )) continue; /* Is there already a connection in this group? */ if( Conf_Server[i].group > NONE ) { for (n = 0; n < MAX_SERVERS; n++) { if (n == i) continue; if ((Conf_Server[n].conn_id != NONE) && (Conf_Server[n].group == Conf_Server[i].group)) break; } if (n < MAX_SERVERS) continue; } /* Check last connect attempt? */ time_now = time(NULL); if( Conf_Server[i].lasttry > (time_now - Conf_ConnectRetry)) continue; /* Okay, try to connect now */ Conf_Server[i].lasttry = time_now; Conf_Server[i].conn_id = SERVER_WAIT; assert(Resolve_Getfd(&Conf_Server[i].res_stat) < 0); Resolve_Name(&Conf_Server[i].res_stat, Conf_Server[i].host, cb_Connect_to_Server); } } /* Check_Servers */ static void New_Server( int Server ) { /* Establish new server link */ struct sockaddr_in new_addr; struct in_addr inaddr; int res, new_sock; CLIENT *c; assert( Server > NONE ); Log( LOG_INFO, "Establishing connection to \"%s\", %s, port %d ... ", Conf_Server[Server].host, Conf_Server[Server].ip, Conf_Server[Server].port ); #ifdef HAVE_INET_ATON if( inet_aton( Conf_Server[Server].ip, &inaddr ) == 0 ) #else memset( &inaddr, 0, sizeof( inaddr )); inaddr.s_addr = inet_addr( Conf_Server[Server].ip ); if( inaddr.s_addr == (unsigned)-1 ) #endif { Log( LOG_ERR, "Can't connect to \"%s\": can't convert ip address %s!", Conf_Server[Server].host, Conf_Server[Server].ip ); return; } memset( &new_addr, 0, sizeof( new_addr )); new_addr.sin_family = (sa_family_t)AF_INET; new_addr.sin_addr = inaddr; new_addr.sin_port = htons( Conf_Server[Server].port ); new_sock = socket( PF_INET, SOCK_STREAM, 0 ); if ( new_sock < 0 ) { Log( LOG_CRIT, "Can't create socket: %s!", strerror( errno )); return; } if( ! Init_Socket( new_sock )) return; res = connect(new_sock, (struct sockaddr *)&new_addr, (socklen_t)sizeof(new_addr)); if(( res != 0 ) && ( errno != EINPROGRESS )) { Log( LOG_CRIT, "Can't connect socket: %s!", strerror( errno )); close( new_sock ); return; } if (!array_alloc(&My_ConnArray, sizeof(CONNECTION), (size_t)new_sock)) { Log(LOG_ALERT, "Cannot allocate memory for server connection (socket %d)", new_sock); close( new_sock ); return; } My_Connections = array_start(&My_ConnArray); assert(My_Connections[new_sock].sock <= 0); Init_Conn_Struct(new_sock); c = Client_NewLocal( new_sock, inet_ntoa( new_addr.sin_addr ), CLIENT_UNKNOWNSERVER, false ); if( ! c ) { Log( LOG_ALERT, "Can't establish connection: can't create client structure!" ); close( new_sock ); return; } Client_SetIntroducer( c, c ); Client_SetToken( c, TOKEN_OUTBOUND ); /* Register connection */ Conf_Server[Server].conn_id = new_sock; My_Connections[new_sock].sock = new_sock; My_Connections[new_sock].addr = new_addr; My_Connections[new_sock].client = c; strlcpy( My_Connections[new_sock].host, Conf_Server[Server].host, sizeof(My_Connections[new_sock].host )); /* Register new socket */ if (!io_event_create( new_sock, IO_WANTWRITE, cb_connserver)) { Log( LOG_ALERT, "io_event_create(): could not add fd %d", strerror(errno)); Conn_Close( new_sock, "io_event_create() failed", NULL, false ); Init_Conn_Struct( new_sock ); Conf_Server[Server].conn_id = NONE; } LogDebug("Registered new connection %d on socket %d.", new_sock, My_Connections[new_sock].sock ); Conn_OPTION_ADD( &My_Connections[new_sock], CONN_ISCONNECTING ); } /* New_Server */ /** * Initialize connection structure. */ static void Init_Conn_Struct(CONN_ID Idx) { time_t now = time(NULL); memset(&My_Connections[Idx], 0, sizeof(CONNECTION)); My_Connections[Idx].sock = -1; My_Connections[Idx].signon = now; My_Connections[Idx].lastdata = now; My_Connections[Idx].lastprivmsg = now; Resolve_Init(&My_Connections[Idx].res_stat); } /* Init_Conn_Struct */ static bool Init_Socket( int Sock ) { /* Initialize socket (set options) */ int value; if (!io_setnonblock(Sock)) { Log( LOG_CRIT, "Can't enable non-blocking mode for socket: %s!", strerror( errno )); close( Sock ); return false; } /* Don't block this port after socket shutdown */ value = 1; if( setsockopt( Sock, SOL_SOCKET, SO_REUSEADDR, &value, (socklen_t)sizeof( value )) != 0 ) { Log( LOG_ERR, "Can't set socket option SO_REUSEADDR: %s!", strerror( errno )); /* ignore this error */ } /* Set type of service (TOS) */ #if defined(IP_TOS) && defined(IPTOS_LOWDELAY) value = IPTOS_LOWDELAY; LogDebug("Setting option IP_TOS on socket %d to IPTOS_LOWDELAY (%d).", Sock, value ); if( setsockopt( Sock, SOL_IP, IP_TOS, &value, (socklen_t)sizeof( value )) != 0 ) { Log( LOG_ERR, "Can't set socket option IP_TOS: %s!", strerror( errno )); /* ignore this error */ } #endif return true; } /* Init_Socket */ static void cb_Connect_to_Server(int fd, UNUSED short events) { /* Read result of resolver sub-process from pipe and start connection */ int i; size_t len; char readbuf[HOST_LEN + 1]; LogDebug("Resolver: Got forward lookup callback on fd %d, events %d", fd, events); for (i=0; i < MAX_SERVERS; i++) { if (Resolve_Getfd(&Conf_Server[i].res_stat) == fd ) break; } if( i >= MAX_SERVERS) { /* Ops, no matching server found?! */ io_close( fd ); LogDebug("Resolver: Got Forward Lookup callback for unknown server!?"); return; } /* Read result from pipe */ len = Resolve_Read(&Conf_Server[i].res_stat, readbuf, sizeof readbuf -1); if (len == 0) return; readbuf[len] = '\0'; LogDebug("Got result from resolver: \"%s\" (%u bytes read).", readbuf, len); strlcpy( Conf_Server[i].ip, readbuf, sizeof( Conf_Server[i].ip )); /* connect() */ New_Server(i); } /* cb_Read_Forward_Lookup */ 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; int i; size_t len; char *identptr; #ifdef IDENTAUTH char readbuf[HOST_LEN + 2 + CLIENT_USER_LEN]; #else char readbuf[HOST_LEN + 1]; #endif LogDebug("Resolver: Got callback on fd %d, events %d", r_fd, events ); /* Search associated connection ... */ for( i = 0; i < Pool_Size; i++ ) { if(( My_Connections[i].sock != NONE ) && ( Resolve_Getfd(&My_Connections[i].res_stat) == r_fd )) break; } if( i >= Pool_Size ) { /* Ops, none found? Probably the connection has already * been closed!? We'll ignore that ... */ io_close( r_fd ); LogDebug("Resolver: Got callback for unknown connection!?"); return; } /* Read result from pipe */ len = Resolve_Read(&My_Connections[i].res_stat, readbuf, sizeof readbuf -1); if (len == 0) return; readbuf[len] = '\0'; identptr = strchr(readbuf, '\n'); assert(identptr != NULL); if (!identptr) { Log( LOG_CRIT, "Resolver: Got malformed result!"); return; } *identptr = '\0'; LogDebug("Got result from resolver: \"%s\" (%u bytes read).", readbuf, len); /* Okay, we got a complete result: this is a host name for outgoing * connections and a host name and IDENT user name (if enabled) for * incoming connections.*/ assert ( My_Connections[i].sock >= 0 ); /* Incoming connection. Search client ... */ c = Conn_GetClient( i ); assert( c != NULL ); /* Only update client information of unregistered clients */ if( Client_Type( c ) == CLIENT_UNKNOWN ) { strlcpy(My_Connections[i].host, readbuf, sizeof( My_Connections[i].host)); Client_SetHostname( c, readbuf); #ifdef IDENTAUTH ++identptr; if (*identptr) { Log( LOG_INFO, "IDENT lookup for connection %ld: \"%s\".", i, identptr); Client_SetUser( c, identptr, true ); } else { Log( LOG_INFO, "IDENT lookup for connection %ld: no result.", i ); } #endif } #ifdef DEBUG else Log( LOG_DEBUG, "Resolver: discarding result for already registered connection %d.", i ); #endif /* Reset penalty time */ Conn_ResetPenalty( i ); } /* cb_Read_Resolver_Result */ static void Simple_Message( int Sock, const char *Msg ) { char buf[COMMAND_LEN]; size_t len; /* Write "simple" message to socket, without using compression * or even the connection write buffers. Used e.g. for error * messages by New_Connection(). */ assert( Sock > NONE ); assert( Msg != NULL ); strlcpy( buf, Msg, sizeof buf - 2); len = strlcat( buf, "\r\n", sizeof buf); (void)write(Sock, buf, len); } /* Simple_Error */ static int Count_Connections( struct sockaddr_in addr_in ) { int i, cnt; cnt = 0; for( i = 0; i < Pool_Size; i++ ) { if(( My_Connections[i].sock > NONE ) && ( My_Connections[i].addr.sin_addr.s_addr == addr_in.sin_addr.s_addr )) cnt++; } return cnt; } /* Count_Connections */ GLOBAL CLIENT * Conn_GetClient( CONN_ID Idx ) { /* return Client-Structure that belongs to the local Connection Idx. * If none is found, return NULL. */ CONNECTION *c; assert( Idx >= 0 ); c = array_get(&My_ConnArray, sizeof (CONNECTION), (size_t)Idx); assert(c != NULL); return c ? c->client : NULL; } /* -eof- */