icinga2/lib/base/netstring.cpp

124 lines
4.0 KiB
C++

/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012 Icinga Development Team (http://www.icinga.org/) *
* *
* 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. *
* *
* This program 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. *
******************************************************************************/
#include "i2-base.h"
using namespace icinga;
/**
* Reads data from a stream in netString format.
*
* @param stream The stream to read from.
* @param[out] str The String that has been read from the IOQueue.
* @returns true if a complete String was read from the IOQueue, false otherwise.
* @exception invalid_argument The input stream is invalid.
* @see https://github.com/PeterScott/netString-c/blob/master/netString.c
*/
bool NetString::ReadStringFromStream(const Stream::Ptr& stream, String *str)
{
/* 16 bytes are enough for the header */
size_t peek_length, buffer_length = 16;
char *buffer = static_cast<char *>(malloc(buffer_length));
if (buffer == NULL)
BOOST_THROW_EXCEPTION(bad_alloc());
peek_length = stream->Peek(buffer, buffer_length);
/* minimum netString length is 3 */
if (peek_length < 3) {
free(buffer);
return false;
}
/* no leading zeros allowed */
if (buffer[0] == '0' && isdigit(buffer[1])) {
free(buffer);
BOOST_THROW_EXCEPTION(invalid_argument("Invalid netString (leading zero)"));
}
size_t len, i;
len = 0;
for (i = 0; i < peek_length && isdigit(buffer[i]); i++) {
/* length specifier must have at most 9 characters */
if (i >= 9) {
free(buffer);
BOOST_THROW_EXCEPTION(invalid_argument("Length specifier must not exceed 9 characters"));
}
len = len * 10 + (buffer[i] - '0');
}
/* read the whole message */
buffer_length = i + 1 + len + 1;
char *new_buffer = static_cast<char *>(realloc(buffer, buffer_length));
if (new_buffer == NULL) {
free(buffer);
BOOST_THROW_EXCEPTION(bad_alloc());
}
buffer = new_buffer;
peek_length = stream->Peek(buffer, buffer_length);
if (peek_length < buffer_length)
return false;
/* check for the colon delimiter */
if (buffer[i] != ':') {
free(buffer);
BOOST_THROW_EXCEPTION(invalid_argument("Invalid NetString (missing :)"));
}
/* check for the comma delimiter after the String */
if (buffer[i + 1 + len] != ',') {
free(buffer);
BOOST_THROW_EXCEPTION(invalid_argument("Invalid NetString (missing ,)"));
}
*str = String(&buffer[i + 1], &buffer[i + 1 + len]);
free(buffer);
/* remove the data from the stream */
stream->Read(NULL, peek_length);
return true;
}
/**
* Writes data into a stream using the netString format.
*
* @param stream The stream.
* @param str The String that is to be written.
*/
void NetString::WriteStringToStream(const Stream::Ptr& stream, const String& str)
{
stringstream prefixbuf;
prefixbuf << str.GetLength() << ":";
String prefix = prefixbuf.str();
stream->Write(prefix.CStr(), prefix.GetLength());
stream->Write(str.CStr(), str.GetLength());
stream->Write(",", 1);
}