You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
sems/apps/sbc/HeaderFilter.cpp

179 lines
3.7 KiB

/*
* Copyright (C) 2010 Stefan Sayer
*
* This file is part of SEMS, a free SIP media server.
*
* SEMS 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.
*
* For a license to use the SEMS software under conditions
* other than those described here, or to purchase support for this
* software, please contact iptel.org by e-mail at the following addresses:
* info@iptel.org
*
* SEMS is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "HeaderFilter.h"
#include "sip/parse_common.h"
#include "log.h"
const char* FilterType2String(FilterType ft) {
switch(ft) {
case Transparent: return "transparent";
case Whitelist: return "whitelist";
case Blacklist: return "blacklist";
default: return "unknown";
};
}
int skip_header(const std::string& hdr, size_t start_pos,
size_t& name_end, size_t& val_begin,
size_t& val_end, size_t& hdr_end) {
// adapted from sip/parse_header.cpp
name_end = val_begin = val_end = start_pos;
hdr_end = hdr.length();
//
// Header states
//
enum {
H_NAME=0,
H_HCOLON,
H_VALUE_SWS,
H_VALUE,
};
int st = H_NAME;
int saved_st = 0;
size_t p = start_pos;
for(;p<hdr.length() && st != ST_LF && st != ST_CRLF;p++){
switch(st){
case H_NAME:
switch(hdr[p]){
case_CR_LF;
case HCOLON:
st = H_VALUE_SWS;
name_end = p;
break;
case SP:
case HTAB:
st = H_HCOLON;
name_end = p;
break;
}
break;
case H_VALUE_SWS:
switch(hdr[p]){
case_CR_LF;
case SP:
case HTAB:
break;
default:
st = H_VALUE;
val_begin = p;
break;
};
break;
case H_VALUE:
switch(hdr[p]){
case_CR_LF;
};
if (st==ST_CR || st==ST_LF)
val_end = p;
break;
case H_HCOLON:
switch(hdr[p]){
case HCOLON:
st = H_VALUE_SWS;
val_begin = p;
break;
case SP:
case HTAB:
break;
default:
DBG("Missing ':' after header name\n");
return MALFORMED_SIP_MSG;
}
break;
case_ST_CR(hdr[p]);
st = saved_st;
hdr_end = p;
break;
}
}
hdr_end = p;
if (p==hdr.length() && st==H_VALUE) {
val_end = p;
}
return 0;
}
int inplaceHeaderFilter(string& hdrs, const set<string>& headerfilter_list, FilterType f_type) {
if (!hdrs.length() || f_type == Transparent)
return 0;
int res = 0;
size_t start_pos = 0;
while (start_pos<hdrs.length()) {
size_t name_end, val_begin, val_end, hdr_end;
if ((res = skip_header(hdrs, start_pos, name_end, val_begin,
val_end, hdr_end)) != 0) {
return res;
}
string hdr_name = hdrs.substr(start_pos, name_end-start_pos);
bool erase = false;
if (f_type == Whitelist) {
erase = headerfilter_list.find(hdr_name)==headerfilter_list.end();
} else if (f_type == Blacklist) {
erase = headerfilter_list.find(hdr_name)!=headerfilter_list.end();
}
if (erase) {
DBG("erasing header '%s'\n", hdr_name.c_str());
hdrs.erase(start_pos, hdr_end-start_pos);
} else {
start_pos = hdr_end;
}
}
// todo: multi-line header support
return res;
}
/** EMACS **
* Local variables:
* mode: c++
* c-basic-offset: 4
* End:
*/