packet_parse.c

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// START OF FILE
/*****************************************************************************/
#ifndef _WIN32
#include <arpa/inet.h>
#else
#include "win32dep.h"
#endif

#include <string.h>

#include "packet_parse.h"

/*****************************************************************************/
// read one byte from buf, 
// return the number of bytes read if succeeds, otherwise return -1
gint read_packet_b(guint8 * buf, guint8 ** cursor, gint buflen, guint8 * b)
{
        if (*cursor <= buf + buflen - sizeof(*b)) {
                *b = **(guint8 **) cursor;
                *cursor += sizeof(*b);
                return sizeof(*b);
        } else
                return -1;
}                               // read_packet_b

/*****************************************************************************/
// read two bytes as "guint16" from buf, 
// return the number of bytes read if succeeds, otherwise return -1
gint read_packet_w(guint8 * buf, guint8 ** cursor, gint buflen, guint16 * w)
{
        if (*cursor <= buf + buflen - sizeof(*w)) {
                *w = ntohs(**(guint16 **) cursor);
                *cursor += sizeof(*w);
                return sizeof(*w);
        } else
                return -1;
}                               // read_packet_w

/*****************************************************************************/
// read four bytes as "guint32" from buf, 
// return the number of bytes read if succeeds, otherwise return -1
gint read_packet_dw(guint8 * buf, guint8 ** cursor, gint buflen, guint32 * dw)
{
        if (*cursor <= buf + buflen - sizeof(*dw)) {
                *dw = ntohl(**(guint32 **) cursor);
                *cursor += sizeof(*dw);
                return sizeof(*dw);
        } else
                return -1;
}                               // read_packet_dw

/*****************************************************************************/
// read datalen bytes from buf, 
// return the number of bytes read if succeeds, otherwise return -1
gint read_packet_data(guint8 * buf, guint8 ** cursor, gint buflen, guint8 * data, gint datalen) {
        if (*cursor <= buf + buflen - datalen) {
                g_memmove(data, *cursor, datalen);
                *cursor += datalen;
                return datalen;
        } else
                return -1;
}                               // read_packet_data

/*****************************************************************************/
// pack one byte into buf
// return the number of bytes packed, otherwise return -1
gint create_packet_b(guint8 * buf, guint8 ** cursor, guint8 b)
{
        if (*cursor <= buf + MAX_PACKET_SIZE - sizeof(guint8)) {
                **(guint8 **) cursor = b;
                *cursor += sizeof(guint8);
                return sizeof(guint8);
        } else
                return -1;
}                               // create_packet_b

/*****************************************************************************/
// pack two bytes as "guint16" into buf
// return the number of bytes packed, otherwise return -1
gint create_packet_w(guint8 * buf, guint8 ** cursor, guint16 w)
{
        if (*cursor <= buf + MAX_PACKET_SIZE - sizeof(guint16)) {
                **(guint16 **) cursor = htons(w);
                *cursor += sizeof(guint16);
                return sizeof(guint16);
        } else
                return -1;
}                               // create_packet_w

/*****************************************************************************/
// pack four bytes as "guint32" into buf
// return the number of bytes packed, otherwise return -1
gint create_packet_dw(guint8 * buf, guint8 ** cursor, guint32 dw)
{
        if (*cursor <= buf + MAX_PACKET_SIZE - sizeof(guint32)) {
                **(guint32 **) cursor = htonl(dw);
                *cursor += sizeof(guint32);
                return sizeof(guint32);
        } else
                return -1;
}                               // create_packet_dw

/*****************************************************************************/
// pack datalen bytes into buf
// return the number of bytes packed, otherwise return -1
gint create_packet_data(guint8 * buf, guint8 ** cursor, guint8 * data, gint datalen) {
        if (*cursor <= buf + MAX_PACKET_SIZE - datalen) {
                g_memmove(*cursor, data, datalen);
                *cursor += datalen;
                return datalen;
        } else
                return -1;
}                               // create_packet_data

/*****************************************************************************/
// END OF FILE

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