/***************************************************************************
* Original Diku Mud copyright (C) 1990, 1991 by Sebastian Hammer, *
* Michael Seifert, Hans Henrik St{rfeldt, Tom Madsen, and Katja Nyboe. *
* *
* Merc Diku Mud improvments copyright (C) 1992, 1993 by Michael *
* Chastain, Michael Quan, and Mitchell Tse. *
* *
* In order to use any part of this Merc Diku Mud, you must comply with *
* both the original Diku license in 'license.doc' as well the Merc *
* license in 'license.txt'. In particular, you may not remove either of *
* these copyright notices. *
* *
* Dystopia Mud improvements copyright (C) 2000, 2001 by Brian Graversen *
* *
* Much time and thought has gone into this software and you are *
* benefitting. We hope that you share your changes too. What goes *
* around, comes around. *
***************************************************************************/
/*
* mccp.c - support functions for mccp (the Mud Client Compression Protocol)
*
* see http://homepages.ihug.co.nz/~icecube/compress/ and README.Rom24-mccp
*
* Copyright (c) 1999, Oliver Jowett <icecube@ihug.co.nz>.
*
* This code may be freely distributed and used if this copyright notice is
* retained intact.
*/
#include <sys/types.h>
#include <sys/time.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include "merc.h"
#include "telnet.h"
char compress_start [] = { IAC, SB, TELOPT_COMPRESS, WILL, SE, '\0' };
bool processCompressed(DESCRIPTOR_DATA *desc);
bool write_to_descriptor args( ( DESCRIPTOR_DATA *d, char *txt, int length ) );
int mccp_mem_usage = 0;
int mccp_mem_freed = 0;
/*
* Memory management - zlib uses these hooks to allocate and free memory
* it needs
*/
void *zlib_alloc(void *opaque, unsigned int items, unsigned int size)
{
/* memory tracking */
mccp_mem_usage += size;
/* return memory pointer */
return calloc(items, size);
}
void zlib_free(void *opaque, void *address)
{
/* memory tracking */
mccp_mem_freed += sizeof(*address);
/* free the cell */
free(address);
}
/*
* Begin compressing data on `desc'
*/
bool compressStart(DESCRIPTOR_DATA *desc)
{
z_stream *s;
if (desc->out_compress) /* already compressing */
return TRUE;
/* allocate and init stream, buffer */
s = (z_stream *)alloc_mem(sizeof(*s));
desc->out_compress_buf = (unsigned char *)alloc_mem(COMPRESS_BUF_SIZE);
s->next_in = NULL;
s->avail_in = 0;
s->next_out = desc->out_compress_buf;
s->avail_out = COMPRESS_BUF_SIZE;
s->zalloc = zlib_alloc;
s->zfree = zlib_free;
s->opaque = NULL;
if (deflateInit(s, 9) != Z_OK) {
/* problems with zlib, try to clean up */
free_mem(desc->out_compress_buf, COMPRESS_BUF_SIZE);
free_mem(s, sizeof(z_stream));
return FALSE;
}
write_to_descriptor(desc, compress_start, strlen(compress_start));
/* now we're compressing */
desc->out_compress = s;
return TRUE;
}
/* Cleanly shut down compression on `desc' */
bool compressEnd(DESCRIPTOR_DATA *desc)
{
unsigned char dummy[1];
if (!desc->out_compress)
return TRUE;
desc->out_compress->avail_in = 0;
desc->out_compress->next_in = dummy;
/* No terminating signature is needed - receiver will get Z_STREAM_END */
if (deflate(desc->out_compress, Z_FINISH) != Z_STREAM_END)
return FALSE;
if (!processCompressed(desc)) /* try to send any residual data */
return FALSE;
deflateEnd(desc->out_compress);
free_mem(desc->out_compress_buf, COMPRESS_BUF_SIZE);
free_mem(desc->out_compress, sizeof(z_stream));
desc->out_compress = NULL;
desc->out_compress_buf = NULL;
return TRUE;
}
bool compressEnd2(DESCRIPTOR_DATA *desc)
{
unsigned char dummy[1];
if (!desc->out_compress)
return TRUE;
desc->out_compress->avail_in = 0;
desc->out_compress->next_in = dummy;
/* No terminating signature is needed - receiver will get Z_STREAM_END */
if (deflate(desc->out_compress, Z_FINISH) != Z_STREAM_END)
return FALSE;
if (!processCompressed(desc)) /* try to send any residual data */
return FALSE;
deflateEnd(desc->out_compress);
desc->out_compress = NULL;
desc->out_compress_buf = NULL;
return TRUE;
}
/* Try to send any pending compressed-but-not-sent data in `desc' */
bool processCompressed(DESCRIPTOR_DATA *desc)
{
int iStart, nBlock, nWrite, len;
if (!desc->out_compress)
return TRUE;
/* Try to write out some data.. */
len = desc->out_compress->next_out - desc->out_compress_buf;
if (len > 0) {
/* we have some data to write */
/* logging the amount of data send */
increase_total_output(len);
for (iStart = 0; iStart < len; iStart += nWrite)
{
nBlock = UMIN (len - iStart, 4096);
if ((nWrite = write (desc->descriptor, desc->out_compress_buf + iStart, nBlock)) < 0)
{
if (errno == EAGAIN ||
errno == ENOSR)
break;
return FALSE; /* write error */
}
if (nWrite <= 0)
break;
}
if (iStart) {
/* We wrote "iStart" bytes */
if (iStart < len)
memmove(desc->out_compress_buf, desc->out_compress_buf+iStart, len - iStart);
desc->out_compress->next_out = desc->out_compress_buf + len - iStart;
}
}
return TRUE;
}
/* write_to_descriptor, the compressed case */
bool writeCompressed(DESCRIPTOR_DATA *desc, char *txt, int length)
{
z_stream *s = desc->out_compress;
s->next_in = (unsigned char *)txt;
s->avail_in = length;
while (s->avail_in) {
s->avail_out = COMPRESS_BUF_SIZE - (s->next_out - desc->out_compress_buf);
if (s->avail_out) {
int status = deflate(s, Z_SYNC_FLUSH);
if (status != Z_OK) {
/* Boom */
return FALSE;
}
}
/* Try to write out some data.. */
if (!processCompressed(desc))
return FALSE;
/* loop */
}
/* Done. */
return TRUE;
}
void do_compres( CHAR_DATA *ch, char *argument )
{
send_to_char("If you want to use compress, spell it out.\n\r",ch);
return;
}
/* User-level compression toggle */
void do_compress( CHAR_DATA *ch, char *argument )
{
if (!ch->desc) {
send_to_char("What descriptor?!\n", ch);
return;
}
if (!ch->desc->out_compress) {
if (!compressStart(ch->desc)) {
send_to_char("Failed.\n", ch);
return;
}
send_to_char("Ok, compression enabled.\n", ch);
}
else {
if (!compressEnd(ch->desc)) {
send_to_char("Failed.\n", ch);
return;
}
send_to_char("Ok, compression disabled.\n", ch);
}
}
void do_showcompress( CHAR_DATA *ch, char *argument )
{
DESCRIPTOR_DATA *d;
CHAR_DATA *gch;
char buf[MAX_STRING_LENGTH];
int count1=0;
int count2=0;
if (IS_NPC(ch)) return;
for ( d = descriptor_list; d != NULL; d = d->next )
{
if ( d->connected != CON_PLAYING) continue;
if ( d->character != NULL ) gch = d->character;
else continue;
if (gch->level > 6) continue;
if (gch->desc->out_compress)
{
sprintf(buf, "%-15s uses mccp\n\r", gch->name);
count1++;
}
else
{
sprintf(buf,"%-15s Does not use mccp.\n\r", gch->name);
count2++;
}
send_to_char(buf,ch);
}
sprintf(buf,"\n\r%d out of %d players uses mccp\n\r",
count1, count2 + count1);
send_to_char(buf,ch);
return;
}