X-Git-Url: https://arthur.barton.de/cgi-bin/gitweb.cgi?p=ngircd-alex.git;a=blobdiff_plain;f=src%2Fngircd%2Fconn-zip.c;h=0a3c17c89b5e07f90945ef245bb072edccb312b0;hp=46cb47ac3d803fbfdf50d17744d1e1840d2e504b;hb=32f63abb59b5c9f47b4d517e0bbf9cc73fd044dc;hpb=1c14e2e0a227c1c883ae793e46353a439b325fc4

diff --git a/src/ngircd/conn-zip.c b/src/ngircd/conn-zip.c
index 46cb47ac..0a3c17c8 100644
--- a/src/ngircd/conn-zip.c
+++ b/src/ngircd/conn-zip.c
@@ -1,25 +1,27 @@
 /*
  * ngIRCd -- The Next Generation IRC Daemon
- * Copyright (c)2001,2002 by Alexander Barton (alex@barton.de)
+ * 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 compression using ZLIB
  */
 
-
 #include "portab.h"
 
-#define CONN_MODULE
+/**
+ * @file
+ * Connection compression using ZLIB
+ */
 
+#define CONN_MODULE
 
 #ifdef ZLIB
 
-static char UNUSED id[] = "$Id: conn-zip.c,v 1.9 2005/08/02 22:48:57 alex Exp $";
+/* enable more zlib related debug messages: */
+/* #define DEBUG_ZLIB */
 
 #include "imp.h"
 #include <assert.h>
@@ -38,7 +40,7 @@ static char UNUSED id[] = "$Id: conn-zip.c,v 1.9 2005/08/02 22:48:57 alex Exp $"
 GLOBAL bool
 Zip_InitConn( CONN_ID Idx )
 {
-	/* Kompression fuer Link initialisieren */
+	/* initialize zlib compression on this link */
 
 	assert( Idx > NONE );
 
@@ -49,10 +51,8 @@ Zip_InitConn( CONN_ID Idx )
 	My_Connections[Idx].zip.in.zfree = NULL;
 	My_Connections[Idx].zip.in.data_type = Z_ASCII;
 
-	if( inflateInit( &My_Connections[Idx].zip.in ) != Z_OK )
-	{
-		/* Fehler! */
-		Log( LOG_ALERT, "Can't initialize compression on connection %d (zlib inflate)!", Idx );
+	if (inflateInit( &My_Connections[Idx].zip.in ) != Z_OK) {
+		Log(LOG_ALERT, "Can't initialize compression on connection %d (zlib inflate)!", Idx);
 		return false;
 	}
 
@@ -62,69 +62,91 @@ Zip_InitConn( CONN_ID Idx )
 	My_Connections[Idx].zip.out.zfree = NULL;
 	My_Connections[Idx].zip.out.data_type = Z_ASCII;
 
-	if( deflateInit( &My_Connections[Idx].zip.out, Z_DEFAULT_COMPRESSION ) != Z_OK )
-	{
-		/* Fehler! */
-		Log( LOG_ALERT, "Can't initialize compression on connection %d (zlib deflate)!", Idx );
+	if (deflateInit( &My_Connections[Idx].zip.out, Z_DEFAULT_COMPRESSION ) != Z_OK) {
+		Log(LOG_ALERT, "Can't initialize compression on connection %d (zlib deflate)!", Idx);
 		return false;
 	}
 
 	My_Connections[Idx].zip.bytes_in = My_Connections[Idx].bytes_in;
 	My_Connections[Idx].zip.bytes_out = My_Connections[Idx].bytes_out;
 
-	Log( LOG_INFO, "Enabled link compression (zlib) on connection %d.", Idx );
+	Log(LOG_INFO, "Enabled link compression (zlib) on connection %d.", Idx);
 	Conn_OPTION_ADD( &My_Connections[Idx], CONN_ZIP );
 
 	return true;
 } /* Zip_InitConn */
 
 
+/**
+ * Copy data to the compression buffer of a connection. We do collect
+ * some data there until it's full so that we can achieve better
+ * compression ratios.
+ * If the (pre-)compression buffer is full, we try to flush it ("actually
+ * compress some data") and to add the new (uncompressed) data afterwards.
+ * This function closes the connection on error.
+ * @param Idx Connection handle.
+ * @param Data Pointer to the data.
+ * @param Len Length of the data to add.
+ * @return true on success, false otherwise.
+ */
 GLOBAL bool
-Zip_Buffer( CONN_ID Idx, char *Data, int Len )
+Zip_Buffer( CONN_ID Idx, const char *Data, size_t Len )
 {
-	/* Daten zum Komprimieren im "Kompressions-Puffer" sammeln.
-	* Es wird true bei Erfolg, sonst false geliefert. */
+	size_t buflen;
 
 	assert( Idx > NONE );
 	assert( Data != NULL );
 	assert( Len > 0 );
-	assert( Len <= ZWRITEBUFFER_LEN );
 
-	if (Len < 0 || Len > ZWRITEBUFFER_LEN) return false;
-
-	if ( array_bytes( &My_Connections[Idx].zip.wbuf ) >= ZWRITEBUFFER_LEN ) {
+	buflen = array_bytes(&My_Connections[Idx].zip.wbuf);
+	if (buflen + Len >= WRITEBUFFER_SLINK_LEN) {
 		/* compression buffer is full, flush */
 		if( ! Zip_Flush( Idx )) return false;
 	}
 
-	return array_catb( &My_Connections[Idx].zip.wbuf, Data, Len );
+	/* check again; if zip buf is still too large do not append data:
+	 * otherwise the zip wbuf would grow too large */
+	buflen = array_bytes(&My_Connections[Idx].zip.wbuf);
+	if (buflen + Len >= WRITEBUFFER_SLINK_LEN) {
+		Log(LOG_ALERT, "Zip Write buffer space exhausted: %lu bytes", buflen + Len);
+		Conn_Close(Idx, "Zip Write buffer space exhausted", NULL, false);
+		return false;
+	}
+	return array_catb(&My_Connections[Idx].zip.wbuf, Data, Len);
 } /* Zip_Buffer */
 
 
+/**
+ * Compress data in ZIP buffer and move result to the write buffer of
+ * the connection.
+ * This function closes the connection on error.
+ * @param Idx Connection handle.
+ * @return true on success, false otherwise.
+ */
 GLOBAL bool
 Zip_Flush( CONN_ID Idx )
 {
-	/* Daten komprimieren und in Schreibpuffer kopieren.
-	* Es wird true bei Erfolg, sonst false geliefert. */
-
 	int result;
-	unsigned char zipbuf[WRITEBUFFER_LEN];
-	unsigned int zipbuf_used = 0;
+	unsigned char zipbuf[WRITEBUFFER_SLINK_LEN];
+	int zipbuf_used = 0;
 	z_stream *out;
 
 	out = &My_Connections[Idx].zip.out;
 
-	out->next_in = array_start(&My_Connections[Idx].zip.wbuf);
-	assert(out->next_in);
-	if (!out->next_in)
-		return false;
+	out->avail_in = (uInt)array_bytes(&My_Connections[Idx].zip.wbuf);
+	if (!out->avail_in)
+		return true;	/* nothing to do. */
 
-	out->avail_in = array_bytes(&My_Connections[Idx].zip.wbuf);
+	out->next_in = array_start(&My_Connections[Idx].zip.wbuf);
+	assert(out->next_in != NULL);
 
 	out->next_out = zipbuf;
-	out->avail_out = sizeof zipbuf;
+	out->avail_out = (uInt)sizeof zipbuf;
 
-	Log(LOG_DEBUG, "out->avail_in %d, out->avail_out %d", out->avail_in, out->avail_out);
+#ifdef DEBUG_ZIP
+	Log(LOG_DEBUG, "out->avail_in %d, out->avail_out %d",
+		out->avail_in, out->avail_out);
+#endif
 	result = deflate( out, Z_SYNC_FLUSH );
 	if(( result != Z_OK ) || ( out->avail_in > 0 ))
 	{
@@ -133,11 +155,26 @@ Zip_Flush( CONN_ID Idx )
 		return false;
 	}
 
-	assert(out->avail_out <= WRITEBUFFER_LEN);
-	zipbuf_used = WRITEBUFFER_LEN - out->avail_out;
+	if (out->avail_out <= 0) {
+		/* Not all data was compressed, because data became
+		 * bigger while compressing it. */
+		Log(LOG_ALERT, "Compression error: buffer overflow!?");
+		Conn_Close(Idx, "Compression error!", NULL, false);
+		return false;
+	}
+
+	assert(out->avail_out <= WRITEBUFFER_SLINK_LEN);
+
+	zipbuf_used = WRITEBUFFER_SLINK_LEN - out->avail_out;
+#ifdef DEBUG_ZIP
 	Log(LOG_DEBUG, "zipbuf_used: %d", zipbuf_used);
-	if (!array_catb( &My_Connections[Idx].wbuf, (char*) zipbuf, zipbuf_used ))
+#endif
+	if (!array_catb(&My_Connections[Idx].wbuf,
+			(char *)zipbuf, (size_t) zipbuf_used)) {
+		Log (LOG_ALERT, "Compression error: can't copy data!?");
+		Conn_Close(Idx, "Compression error!", NULL, false);
 		return false;
+	}
 
 	My_Connections[Idx].bytes_out += zipbuf_used;
 	My_Connections[Idx].zip.bytes_out += array_bytes(&My_Connections[Idx].zip.wbuf); 
@@ -147,16 +184,20 @@ Zip_Flush( CONN_ID Idx )
 } /* Zip_Flush */
 
 
+/**
+ * uncompress data and copy it to read buffer.
+ * Returns true if data has been unpacked or no
+ * compressed data is currently pending in the zread buffer.
+ * This function closes the connection on error.
+ * @param Idx Connection handle.
+ * @return true on success, false otherwise.
+ */
 GLOBAL bool
 Unzip_Buffer( CONN_ID Idx )
 {
-	/* Daten entpacken und in Lesepuffer kopieren. Bei Fehlern
-	* wird false geliefert, ansonsten true. Der Fall, dass keine
-	* Daten mehr zu entpacken sind, ist _kein_ Fehler! */
-
 	int result;
 	unsigned char unzipbuf[READBUFFER_LEN];
-	unsigned int unzipbuf_used = 0;
+	int unzipbuf_used = 0;
 	unsigned int z_rdatalen;
 	unsigned int in_len;
 	
@@ -164,38 +205,45 @@ Unzip_Buffer( CONN_ID Idx )
 
 	assert( Idx > NONE );
 
-	z_rdatalen = array_bytes(&My_Connections[Idx].zip.rbuf);
+	z_rdatalen = (unsigned int)array_bytes(&My_Connections[Idx].zip.rbuf);
 	if (z_rdatalen == 0)
 		return true;
 
 	in = &My_Connections[Idx].zip.in;
-	
+
 	in->next_in = array_start(&My_Connections[Idx].zip.rbuf);
-	assert(in->next_in);
-	if (!in->next_in)
-		return false;
+	assert(in->next_in != NULL);
 
 	in->avail_in = z_rdatalen;
 	in->next_out = unzipbuf;
-	in->avail_out = sizeof unzipbuf;
+	in->avail_out = (uInt)sizeof unzipbuf;
 
-	Log(LOG_DEBUG, "in->avail_in %d, in->avail_out %d", in->avail_in, in->avail_out);
+#ifdef DEBUG_ZIP
+	Log(LOG_DEBUG, "in->avail_in %d, in->avail_out %d",
+		in->avail_in, in->avail_out);
+#endif
 	result = inflate( in, Z_SYNC_FLUSH );
 	if( result != Z_OK )
 	{
-		Log( LOG_ALERT, "Decompression error: %s (code=%d, ni=%d, ai=%d, no=%d, ao=%d)!?", in->msg, result, in->next_in, in->avail_in, in->next_out, in->avail_out );
-		Conn_Close( Idx, "Decompression error!", NULL, false );
+		Log(LOG_ALERT, "Decompression error: %s (code=%d, ni=%d, ai=%d, no=%d, ao=%d)!?", in->msg, result, in->next_in, in->avail_in, in->next_out, in->avail_out);
+		Conn_Close(Idx, "Decompression error!", NULL, false);
 		return false;
 	}
 
 	assert(z_rdatalen >= in->avail_in);
 	in_len = z_rdatalen - in->avail_in;
 	unzipbuf_used = READBUFFER_LEN - in->avail_out;
-	Log(LOG_DEBUG, "unzipbuf_used: %d - %d = %d", READBUFFER_LEN,  in->avail_out, unzipbuf_used);
+#ifdef DEBUG_ZIP
+	Log(LOG_DEBUG, "unzipbuf_used: %d - %d = %d", READBUFFER_LEN,
+		in->avail_out, unzipbuf_used);
+#endif
 	assert(unzipbuf_used <= READBUFFER_LEN);
-	if (!array_catb(&My_Connections[Idx].rbuf, (char*) unzipbuf, unzipbuf_used))
+	if (!array_catb(&My_Connections[Idx].rbuf, (char*) unzipbuf,
+			(size_t)unzipbuf_used)) {
+		Log (LOG_ALERT, "Decompression error: can't copy data!?");
+		Conn_Close(Idx, "Decompression error!", NULL, false);
 		return false;
-
+	}
 	if( in->avail_in > 0 ) {
 		array_moveleft(&My_Connections[Idx].zip.rbuf, 1, in_len );
 	} else {
@@ -207,21 +255,25 @@ Unzip_Buffer( CONN_ID Idx )
 } /* Unzip_Buffer */
 
 
+/**
+ * @param Idx Connection handle.
+ * @return amount of sent (compressed) bytes
+ */
 GLOBAL long
 Zip_SendBytes( CONN_ID Idx )
 {
-	/* Anzahl gesendeter Bytes (komprimiert!) liefern */
-
 	assert( Idx > NONE );
 	return My_Connections[Idx].zip.bytes_out;
 } /* Zip_SendBytes */
 
 
+/**
+ * @param Idx Connection handle.
+ * @return amount of received (compressed) bytes
+ */
 GLOBAL long
 Zip_RecvBytes( CONN_ID Idx )
 {
-	/* Anzahl gesendeter Bytes (komprimiert!) liefern */
-
 	assert( Idx > NONE );
 	return My_Connections[Idx].zip.bytes_in;
 } /* Zip_RecvBytes */