Adding port number on the ethernet protocol.
/*
Terminal Mixer - multi-point multi-user access to terminal applications
Copyright (C) 2007 LluĂs Batlle i Rossell
Please find the license in the provided COPYING file.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "main.h"
#include "filter.h"
void add_ffilter(struct FilterRules *fr, struct FFilter *ff)
{
fr->nfilters += 1;
fr->filters = (struct FFilter **) realloc(fr->filters,
sizeof(*fr->filters) * fr->nfilters);
if (fr->filters == 0) error("realloc failed.");
fr->filters[fr->nfilters-1] = ff;
ff->matched = 0;
}
struct FilterRules * new_filter_rules()
{
struct FilterRules *fr;
fr = (struct FilterRules *) malloc(sizeof(*fr));
if (fr == 0) error("malloc failed.");
fr->nfilters = 0;
fr->filters = 0; /* null for realloc */
fr->fbuffer = 0;
fr->fbuffer_len = 0;
fr->fbuffer_allocated = 0;
return fr;
}
/* We want to access index even before the 'buffer' limits.
* Those are at fr->fbuffer, and referred as -X indexes. */
static int get_char(struct FilterRules *fr, const unsigned char *buffer, int pos)
{
if (pos >= 0)
return buffer[pos];
else
{
if (-pos > fr->fbuffer_len)
return -1;
/* pos is negative */
return fr->fbuffer[fr->fbuffer_len + pos];
}
}
static int set_char(struct FilterRules *fr, unsigned char *buffer, int pos, int c)
{
if (pos >= 0)
{
buffer[pos] = c;
return buffer[pos];
}
else
{
if (-pos > fr->fbuffer_len)
return -1;
fr->fbuffer[fr->fbuffer_len - pos] = c;
return fr->fbuffer[fr->fbuffer_len - pos];
}
}
/* Return 1 if matches */
static int apply_ffilter(struct FilterRules *fr, struct FFilter *ff,
char *obuf, int *olen, const unsigned char *buffer, int pos)
{
int res;
res = ff->function(ff, buffer[pos]);
if (res)
{
/* String matches */
if (ff->callback)
{
int shift;
shift = pos - ff->matched;
/* Call callback */
ff->callback(fr, ff, obuf, olen, buffer, shift);
}
return 1;
}
return 0;
}
static void reset_matched(struct FilterRules *fr)
{
int i;
for (i=0; i < fr->nfilters; ++i)
{
struct FFilter *ff;
ff = fr->filters[i];
ff->matched = 0;
if (ff->reset)
ff->reset(ff);
}
}
void filter_stream(struct FilterRules *fr, char *obuf, int *olen, const char *buffer, int len)
{
int i;
int ipos;
int max_matched;
*olen = 0;
ipos = - fr->fbuffer_len;
max_matched = fr->fbuffer_len;
for(i=0; i< len; ++i)
{ /* each char */
int j;
int old_max_matched = max_matched;
int found = 0;
max_matched = 0;
/*printf("Try '%c'...\n", buffer[i]);*/
for (j=0; j < fr->nfilters; ++j)
{
struct FFilter *ff;
ff = fr->filters[j];
found = apply_ffilter(fr, ff, obuf, olen, buffer, i);
max_matched = max(max_matched, ff->matched);
if (found)
break;
}
/* Some chars may not be needed for the filters
* already. */
/*printf("ipos: %i\n", ipos);*/
if (found)
{
/*printf("[match!]\n");*/
reset_matched(fr);
/* The longest string will be matched, sure. Right?*/
ipos += max_matched;
max_matched = 0;
}
else
{
int freed = old_max_matched + 1 /* new char */ - max_matched;
for(j=0; j < freed; ++j)
{
obuf[(*olen)++] = get_char(fr, buffer, ipos++);
}
}
}
if (max_matched > fr->fbuffer_allocated)
{
fr->fbuffer = realloc(fr->fbuffer, max_matched);
if (fr->fbuffer == 0) error("Cannot allocate fbuffer");
}
/* Copy only new data from buffer */
{
int start_new_data;
int size_cpy;
int offset;
size_cpy = max_matched;
start_new_data = len - max_matched;
offset = 0;
if (start_new_data < 0)
{
offset += (-start_new_data);
size_cpy -= (-start_new_data);
start_new_data = 0;
}
memcpy(fr->fbuffer + offset, buffer + start_new_data, size_cpy);
fr->fbuffer_len = max_matched;
}
}
void filter_flush(struct FilterRules *fr, char *obuf, int *olen)
{
memcpy(obuf, fr->fbuffer, fr->fbuffer_len);
*olen = fr->fbuffer_len;
fr->fbuffer_len = 0;
}