/*
 MySecureShell permit to add restriction to modified sftp-server
 when using MySecureShell as shell.
 Copyright (C) 2007-2014 MySecureShell Team

 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 (version 2)

 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include "../config.h"
#include <stdlib.h>
#include <string.h>
#include "Buffer.h"

/*@null@*/ tBuffer *BufferNew()
{
	tBuffer *b;

	b = malloc(sizeof(*b));
	if (b != NULL)
	{
		b->size = DEFAULT_GROW;
		b->data = malloc(b->size);
		b->length = 0;
		b->read = 0;
		b->fastClean = 0;
	}
	return (b);
}

void BufferGrow(tBuffer *b, u_int32_t toAdd)
{
	b->size += toAdd;
	b->data = realloc(b->data, b->size);
}

void BufferClean(tBuffer *b)
{
	if (b->read > 0)
	{
		if (b->length > b->read)
		{
			memmove(b->data, b->data + b->read, b->length - b->read);
			b->length -= b->read;
		}
		else
			b->length = 0;
		b->read = 0;
		if (b->fastClean == 0)
		{
			u_int32_t nextSize;

			nextSize = b->size >> 2;
			if (b->length < nextSize && nextSize >= DEFAULT_GROW)
			{
				b->size = nextSize;
				b->data = realloc(b->data, b->size);
			}
		}
	}
}

void BufferDelete(tBuffer *b)
{
	free(b->data);
	free(b);
}

void BufferPutInt8(tBuffer *b, u_int8_t nb)
{
	if ((b->length + 1) > b->size)
		BufferGrow(b, DEFAULT_GROW);
	b->data[b->length++] = nb;
}

void BufferPutInt16(tBuffer *b, u_int16_t nb)
{
	if ((b->length + 2) > b->size)
		BufferGrow(b, DEFAULT_GROW);
	b->data[b->length++] = (nb >> 8);
	b->data[b->length++] = nb;
}

void BufferPutInt32(tBuffer *b, u_int32_t nb)
{
	if ((b->length + 4) > b->size)
		BufferGrow(b, DEFAULT_GROW);
	b->data[b->length++] = (nb >> 24);
	b->data[b->length++] = (nb >> 16);
	b->data[b->length++] = (nb >> 8);
	b->data[b->length++] = nb;
}

void BufferPutInt64(tBuffer *b, u_int64_t nb)
{
	u_int32_t n1, n2;

	n1 = (u_int64_t) nb >> (u_int64_t) 32;
	n2 = (u_int64_t) nb & (u_int64_t) 0xffffffff;
	if ((b->length + 8) > b->size)
		BufferGrow(b, DEFAULT_GROW);
	b->data[b->length++] = (n1 >> 24);
	b->data[b->length++] = (n1 >> 16);
	b->data[b->length++] = (n1 >> 8);
	b->data[b->length++] = n1;
	b->data[b->length++] = (n2 >> 24);
	b->data[b->length++] = (n2 >> 16);
	b->data[b->length++] = (n2 >> 8);
	b->data[b->length++] = n2;
}

void BufferPutRawData(tBuffer *b, const void *data, u_int32_t size)
{
	if ((b->length + size) > b->size)
		BufferGrow(b, b->length + size - b->size + DEFAULT_GROW);
	memcpy(b->data + b->length, data, size);
	b->length += size;
}

void BufferPutString(tBuffer *b, const char *data)
{
	size_t size;

	size = strlen(data);
	if ((b->length + size + 4) > b->size)
		BufferGrow(b, b->length + size + 4 - b->size + DEFAULT_GROW);
	b->data[b->length++] = (size >> 24);
	b->data[b->length++] = (size >> 16);
	b->data[b->length++] = (size >> 8);
	b->data[b->length++] = size;
	memcpy(b->data + b->length, data, size);
	b->length += size;
}

void BufferPutHandle(tBuffer *b, int h)
{
	if ((b->length + BufferHandleSize) > b->size)
		BufferGrow(b, b->length + BufferHandleSize - b->size + DEFAULT_GROW);
	b->data[b->length++] = 0;
	b->data[b->length++] = 0;
	b->data[b->length++] = 0;
	b->data[b->length++] = 2;
	BufferPutInt8FAST(b, h + (int )'0');
	BufferPutInt8FAST(b, '\0');
}

#ifdef DODEBUG
#include "Log.h"

static char *ASCII = "0123456789ABCDEF";

static void dumpPacket(tBuffer *b, int trySize)
{
	char *buffer;
	int i, pos;

	mylog_printf(MYLOG_DEBUG, "[dumpPacket][length:%i][read:%i][size:%i][trySize:%i]",
			b->length, b->read, b->size, trySize);
	buffer = malloc(b->length * 2 + 1);
	for (i = b->read, pos = 0; i < b->length; i++)
	{
		unsigned char c = (unsigned char)b->data[i];

		buffer[pos++] = ASCII[c / 16];
		buffer[pos++] = ASCII[c % 16];
	}
	buffer[pos] = 0;
	mylog_printf(MYLOG_DEBUG, "[%s]", buffer);
	free(buffer);
}

#endif

void BufferReadData(tBuffer *b, u_int32_t size)
{
	if ((b->read + size) <= b->length)
		b->read += size;
#ifdef DODEBUG
	else
	dumpPacket(b, size);
#endif
}

u_int8_t BufferGetInt8(tBuffer *b)
{
	u_int8_t nb;

	if ((b->read + 1) > b->length)
	{
#ifdef DODEBUG
		dumpPacket(b, 1);
#endif
		return (0);
	}
	nb = (u_int8_t) b->data[b->read++];
	return (nb);
}

u_int32_t BufferGetInt32(tBuffer *b)
{
	u_int32_t nb;

	if ((b->read + 4) > b->length)
	{
#ifdef DODEBUG
		dumpPacket(b, 4);
#endif
		return (0);
	}
	nb = (u_int32_t) b->data[b->read++] << 24;
	nb += (u_int32_t) b->data[b->read++] << 16;
	nb += (u_int32_t) b->data[b->read++] << 8;
	nb += (u_int32_t) b->data[b->read++];
	return (nb);
}

u_int64_t BufferGetInt64(tBuffer *b)
{
	u_int64_t nb;

	if ((b->read + 8) > b->length)
	{
#ifdef DODEBUG
		dumpPacket(b, 8);
#endif
		return (0);
	}
	nb = (u_int64_t) b->data[b->read++] << 56;
	nb += (u_int64_t) b->data[b->read++] << 48;
	nb += (u_int64_t) b->data[b->read++] << 40;
	nb += (u_int64_t) b->data[b->read++] << 32;
	nb += (u_int64_t) b->data[b->read++] << 24;
	nb += (u_int64_t) b->data[b->read++] << 16;
	nb += (u_int64_t) b->data[b->read++] << 8;
	nb += (u_int64_t) b->data[b->read++];
	return (nb);
}

char *BufferGetData(tBuffer *b, u_int32_t *size)
{
	char *data;

	*size = BufferGetInt32(b);
	if ((b->read + *size) > b->length)
	{
#ifdef DODEBUG
		dumpPacket(b, *size);
#endif
		return (NULL);
	}
	data = (char *) (b->data + b->read);
	b->read += *size;
	return (data);
}

char *BufferGetString(tBuffer *b)
{
	char *data;
	u_int32_t size;

	size = BufferGetInt32(b);
	if ((b->read + size) > b->length)
	{
#ifdef DODEBUG
		dumpPacket(b, size);
#endif
		return (0);
	}
	data = malloc(size + 1);
	if (data)
	{
		memcpy(data, b->data + b->read, size);
		data[size] = 0;
		b->read += size;
	}
	return (data);
}

int BufferGetHandle(tBuffer *b)
{
	u_int32_t size;
	int hdl = -1;

	size = BufferGetInt32(b);
	if (size == 2)
	{
		hdl = BufferGetInt8FAST(b) - (int) '0';
		BufferIncrCurrentReadPosition(b, 1);
	}
	return (hdl);
}