sbgNetwork.c

Go to the documentation of this file.

#include "sbgNetwork.h"
#include <swap/sbgSwap.h>

//----------------------------------------------------------------------//
//- IP manipulation methods                                            -//
//----------------------------------------------------------------------//

SBG_COMMON_LIB_API void sbgNetworkIpToString(sbgIpAddress ipAddr, char *pBuffer, size_t maxSize)
{
        //
        // Check input arguments
        //
        assert(pBuffer);
        assert(maxSize >= 16);

        SBG_UNUSED_PARAMETER(maxSize);

        //
        // Write the IP address
        //
        sprintf(pBuffer, "%u.%u.%u.%u", sbgIpAddrGetA(ipAddr), sbgIpAddrGetB(ipAddr), sbgIpAddrGetC(ipAddr), sbgIpAddrGetD(ipAddr));
}

SBG_COMMON_LIB_API sbgIpAddress sbgNetworkIpFromString(const char *pBuffer)
{
        int32_t ipAddrA;
        int32_t ipAddrB;
        int32_t ipAddrC;
        int32_t ipAddrD;
        int32_t numReadParams;

        //
        // Check input arguments
        //
        assert(pBuffer);

        //
        // Parse input arguments
        //
        numReadParams = sscanf(pBuffer, "%d.%d.%d.%d", &ipAddrA, &ipAddrB, &ipAddrC, &ipAddrD);

        //
        // Make sure the parsed IP is normal
        //
        if ((numReadParams == 4) && (ipAddrA >= 0) && (ipAddrA <= 255) && (ipAddrB >= 0) && (ipAddrB <= 255) && (ipAddrC >= 0) && (ipAddrC <= 255) && (ipAddrD >= 0) && (ipAddrD <= 255))
        {
                //
                // Ip address correctly parsed, return it
                //
                return sbgIpAddr((uint8_t)ipAddrA, (uint8_t)ipAddrB, (uint8_t)ipAddrC, (uint8_t)ipAddrD);
        }
        else
        {
                //
                // The IP address couldn't be parsed correctly, return a null ip address
                //
                return sbgIpAddr(0, 0, 0, 0);
        }
}

//----------------------------------------------------------------------//
//- IP validation methods                                              -//
//----------------------------------------------------------------------//

SBG_COMMON_LIB_API bool sbgIpNetMaskValid(sbgIpAddress netmask)
{
        uint32_t        y;
        uint32_t        z;

        //
        // First test that the netmask is not zero, if yes, it's valid
        //
        if (netmask != 0)
        {
                //
                // We are doing arithmetic so we have to make sure the netmask is using the platform endianness
                // The IP address is always stored in big endian so we have to swap it for little endian platforms
                //
#if SBG_CONFIG_BIG_ENDIAN == 0
                netmask = sbgSwap32(netmask);
#endif

                //
                // Compute the bitwise inverse
                //
                y = ~netmask;

                //
                // Add one to the inverse so if netmask was a proper one, there will be at most 1 bit set in this.
                //
                z = y + 1;

                //
                // Test that, simply and z with z - 1, which happens to be y. The result will be zero if all is OK, non zero otherwise.
                //
                if ((z&y) == 0)
                {
                        //
                        // We have a valid netmask
                        //
                        return true;
                }
                else
                {
                        return false;
                }
        }

        return true;
}