icinga2/base/netstring.cpp

129 lines
4.1 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 an IOQueue in netString format.
*
* @param fifo The IOQueue to read from.
* @param[out] str The String that has been read from the FIFO.
* @returns true if a complete String was read from the FIFO, false otherwise.
* @exception invalid_argument The input stream is invalid.
* @see https://github.com/PeterScott/netString-c/blob/master/netString.c
*/
bool NetString::ReadStringFromIOQueue(IOQueue *queue, String *str)
{
size_t buffer_length = queue->GetAvailableBytes();
/* minimum netString length is 3 */
if (buffer_length < 3)
return false;
/* limit the number of bytes we're reading for the header */
if (buffer_length > 16)
buffer_length = 16;
char *buffer = (char *)malloc(buffer_length);
if (buffer == NULL && buffer_length > 0)
throw_exception(bad_alloc());
queue->Peek(buffer, buffer_length);
/* no leading zeros allowed */
if (buffer[0] == '0' && isdigit(buffer[1])) {
free(buffer);
throw_exception(invalid_argument("Invalid netString (leading zero)"));
}
size_t len, i;
len = 0;
for (i = 0; i < buffer_length && isdigit(buffer[i]); i++) {
/* length specifier must have at most 9 characters */
if (i >= 9) {
free(buffer);
throw_exception(invalid_argument("Length specifier must not exceed 9 characters"));
}
len = len * 10 + (buffer[i] - '0');
}
buffer_length = queue->GetAvailableBytes();
/* make sure the buffer is large enough */
if (i + len + 1 >= buffer_length)
return false;
/* limit the number of bytes we're reading to this message */
buffer_length = i + 1 + len + 1;
char *new_buffer = (char *)realloc(buffer, buffer_length);
if (new_buffer == NULL) {
free(buffer);
throw_exception(bad_alloc());
}
buffer = new_buffer;
queue->Peek(buffer, buffer_length);
/* check for the colon delimiter */
if (buffer[i] != ':') {
free(buffer);
throw_exception(invalid_argument("Invalid NetString (missing :)"));
}
/* check for the comma delimiter after the String */
if (buffer[i + 1 + len] != ',') {
free(buffer);
throw_exception(invalid_argument("Invalid NetString (missing ,)"));
}
*str = String(&buffer[i + 1], &buffer[i + 1 + len]);
free(buffer);
/* remove the data from the fifo */
queue->Read(NULL, buffer_length);
return true;
}
/**
* Writes data into a FIFO using the netString format.
*
* @param fifo The FIFO.
* @param str The String that is to be written.
*/
void NetString::WriteStringToIOQueue(IOQueue *queue, const String& str)
{
stringstream prefixbuf;
prefixbuf << str.GetLength() << ":";
String prefix = prefixbuf.str();
queue->Write(prefix.CStr(), prefix.GetLength());
queue->Write(str.CStr(), str.GetLength());
queue->Write(",", 1);
}