/*
 * COPYRIGHT:   See COPYING in the top level directory
 * PROJECT:     ReactOS ping utility
 * FILE:        base/applications/network/ping/ping.c
 * PURPOSE:     Network test utility
 * PROGRAMMERS:
 */

#include <winsock2.h>
#include <ws2tcpip.h>
#include <tchar.h>
#include <stdarg.h>
#include <string.h>
#include <stdio.h>

#define NDEBUG

/* General ICMP constants */
#define ICMP_MINSIZE        8     /* Minimum ICMP packet size */
#define ICMP_MAXSIZE        65535 /* Maximum ICMP packet size */

/* ICMP message types */
#define ICMPMSG_ECHOREQUEST 8     /* ICMP ECHO request message */
#define ICMPMSG_ECHOREPLY   0     /* ICMP ECHO reply message */

#pragma pack(4)

/* IPv4 header structure */
typedef struct _IPv4_HEADER
{
    unsigned char IHL:4;
    unsigned char Version:4;
    unsigned char TOS;
    unsigned short Length;
    unsigned short Id;
    unsigned short FragFlags;
    unsigned char TTL;
    unsigned char Protocol;
    unsigned short Checksum;
    unsigned int SrcAddress;
    unsigned int DstAddress;
} IPv4_HEADER, *PIPv4_HEADER;

/* ICMP echo request/reply header structure */
typedef struct _ICMP_HEADER
{
    unsigned char Type;
    unsigned char Code;
    unsigned short Checksum;
    unsigned short Id;
    unsigned short SeqNum;
} ICMP_HEADER, *PICMP_HEADER;

typedef struct _ICMP_ECHO_PACKET
{
    ICMP_HEADER Icmp;
} ICMP_ECHO_PACKET, *PICMP_ECHO_PACKET;

#pragma pack(1)

BOOL                InvalidOption;
BOOL                NeverStop;
BOOL                ResolveAddresses;
UINT                PingCount;
UINT                DataSize;   /* ICMP echo request data size */
BOOL                DontFragment;
ULONG               TTLValue;
ULONG               TOSValue;
ULONG               Timeout;
CHAR                TargetName[256];
SOCKET              IcmpSock;
SOCKADDR_IN         Target;
LPSTR               TargetIP;
FD_SET              Fds;
TIMEVAL             Timeval;
UINT                CurrentSeqNum;
UINT                SentCount;
UINT                LostCount;
BOOL                MinRTTSet;
LARGE_INTEGER       MinRTT;     /* Minimum round trip time in microseconds */
LARGE_INTEGER       MaxRTT;
LARGE_INTEGER       SumRTT;
LARGE_INTEGER       AvgRTT;
LARGE_INTEGER       TicksPerMs; /* Ticks per millisecond */
LARGE_INTEGER       TicksPerUs; /* Ticks per microsecond */
LARGE_INTEGER       SentTime;
BOOL                UsePerformanceCounter;

#ifndef NDEBUG
/* Display the contents of a buffer */
static VOID DisplayBuffer(
    PVOID Buffer,
    DWORD Size)
{
    UINT i;
    PCHAR p;

    printf("Buffer (0x%p)  Size (0x%lX).\n", Buffer, Size);

    p = (PCHAR)Buffer;
    for (i = 0; i < Size; i++)
    {
        if (i % 16 == 0)
            printf("\n");
        printf("%02X ", (p[i]) & 0xFF);
    }
}
#endif /* !NDEBUG */

/* Display usage information on screen */
static VOID Usage(VOID)
{
    printf("\nUsage: ping [-t] [-n count] [-l size] [-w timeout] destination-host\n\n");
    printf("Options:\n");
    printf("    -t             Ping the specified host until stopped.\n");
    printf("                   To stop - type Control-C.\n");
    printf("    -n count       Number of echo requests to send.\n");
    printf("    -l size        Send buffer size.\n");
    printf("    -w timeout     Timeout in milliseconds to wait for each reply.\n\n");
}

/* Reset configuration to default values */
static VOID Reset(VOID)
{
    LARGE_INTEGER PerformanceCounterFrequency;

    NeverStop             = FALSE;
    ResolveAddresses      = FALSE;
    PingCount             = 4;
    DataSize              = 32;
    DontFragment          = FALSE;
    TTLValue              = 128;
    TOSValue              = 0;
    Timeout               = 1000;
    UsePerformanceCounter = QueryPerformanceFrequency(&PerformanceCounterFrequency);

    if (UsePerformanceCounter)
    {
        /* Performance counters may return incorrect results on some multiprocessor
           platforms so we restrict execution on the first processor. This may fail
           on Windows NT so we fall back to GetCurrentTick() for timing */
        if (SetThreadAffinityMask (GetCurrentThread(), 1) == 0)
            UsePerformanceCounter = FALSE;

        /* Convert frequency to ticks per millisecond */
        TicksPerMs.QuadPart = PerformanceCounterFrequency.QuadPart / 1000;
        /* And to ticks per microsecond */
        TicksPerUs.QuadPart = PerformanceCounterFrequency.QuadPart / 1000000;
    }
    if (!UsePerformanceCounter)
    {
        /* 1 tick per millisecond for GetCurrentTick() */
        TicksPerMs.QuadPart = 1;
        /* GetCurrentTick() cannot handle microseconds */
        TicksPerUs.QuadPart = 1;
    }
}

/* Return ULONG in a string */
static ULONG GetULONG(LPSTR String)
{
    UINT i, Length;
    ULONG Value;
    LPSTR StopString;
    i = 0;
    Length = (UINT)_tcslen(String);
    while ((i < Length) && ((String[i] < '0') || (String[i] > '9'))) i++;
    if ((i >= Length) || ((String[i] < '0') || (String[i] > '9')))
    {
        InvalidOption = TRUE;
        return 0;
    }
    Value = strtoul(&String[i], &StopString, 10);

    return Value;
}

/* Return ULONG in a string. Try next paramter if not successful */
static ULONG GetULONG2(LPSTR String1, LPSTR String2, PINT i)
{
    ULONG Value;

    Value = GetULONG(String1);
    if (InvalidOption)
    {
        InvalidOption = FALSE;
        if (String2[0] != '-')
        {
            Value = GetULONG(String2);
            if (!InvalidOption)
                *i += 1;
        }
    }

    return Value;
}

/* Parse command line parameters */
static BOOL ParseCmdline(int argc, char* argv[])
{
    INT i;
    BOOL ShowUsage;
    BOOL FoundTarget;
    if (argc < 2)
        ShowUsage = TRUE;
    else
        ShowUsage = FALSE;
    FoundTarget = FALSE;
    InvalidOption = FALSE;

    for (i = 1; i < argc; i++)
    {
        if (argv[i][0] == '-')
        {
            switch (argv[i][1])
            {
                case 't': NeverStop = TRUE; break;
                case 'a': ResolveAddresses = TRUE; break;
                case 'n': PingCount = GetULONG2(&argv[i][2], argv[i + 1], &i); break;
                case 'l':
                    DataSize = GetULONG2(&argv[i][2], argv[i + 1], &i);
                    if (DataSize > ICMP_MAXSIZE - sizeof(ICMP_ECHO_PACKET) - sizeof(IPv4_HEADER))
                    {
                        printf("Bad value for option -l, valid range is from 0 to %d.\n",
                            ICMP_MAXSIZE - (int)sizeof(ICMP_ECHO_PACKET) - (int)sizeof(IPv4_HEADER));
                        return FALSE;
                   }
                    break;
                case 'f': DontFragment = TRUE; break;
                case 'i': TTLValue = GetULONG2(&argv[i][2], argv[i + 1], &i); break;
                case 'v': TOSValue = GetULONG2(&argv[i][2], argv[i + 1], &i); break;
                case 'w': Timeout  = GetULONG2(&argv[i][2], argv[i + 1], &i); break;
                default:
                    printf("Bad option %s.\n", argv[i]);
                    Usage();
                    return FALSE;
            }
            if (InvalidOption)
            {
                printf("Bad option format %s.\n", argv[i]);
                return FALSE;
            }
        }
        else
        {
            if (FoundTarget)
            {
                printf("Bad parameter %s.\n", argv[i]);
                return FALSE;
            }
            else
            {
                lstrcpy(TargetName, argv[i]);
                FoundTarget = TRUE;
            }
        }
    }

    if ((!ShowUsage) && (!FoundTarget))
    {
        printf("Name or IP address of destination host must be specified.\n");
        return FALSE;
    }

    if (ShowUsage)
    {
        Usage();
        return FALSE;
    }
    return TRUE;
}

/* Calculate checksum of data */
static WORD Checksum(PUSHORT data, UINT size)
{
    ULONG sum = 0;

    while (size > 1)
    {
        sum  += *data++;
        size -= sizeof(USHORT);
    }

    if (size)
        sum += *(UCHAR*)data;

    sum = (sum >> 16) + (sum & 0xFFFF);
    sum += (sum >> 16);

    return (USHORT)(~sum);
}

/* Prepare to ping target */
static BOOL Setup(VOID)
{
    WORD     wVersionRequested;
    WSADATA  WsaData;
    INT      Status;
    ULONG    Addr;
    PHOSTENT phe;

    wVersionRequested = MAKEWORD(2, 2);

    Status = WSAStartup(wVersionRequested, &WsaData);
    if (Status != 0)
    {
        printf("Could not initialize winsock dll.\n");
        return FALSE;
    }

    IcmpSock = WSASocket(AF_INET, SOCK_RAW, IPPROTO_ICMP, NULL, 0, 0);
    if (IcmpSock == INVALID_SOCKET)
    {
        printf("Could not create socket (#%d).\n", WSAGetLastError());
        return FALSE;
    }

    if (setsockopt(IcmpSock,
                   IPPROTO_IP,
                   IP_DONTFRAGMENT,
                   (const char *)&DontFragment,
                   sizeof(DontFragment)) == SOCKET_ERROR)
    {
         printf("setsockopt failed (%d).\n", WSAGetLastError());
         return FALSE;
    }

    if (setsockopt(IcmpSock,
                   IPPROTO_IP,
                   IP_TTL,
                   (const char *)&TTLValue,
                   sizeof(TTLValue)) == SOCKET_ERROR)
    {
         printf("setsockopt failed (%d).\n", WSAGetLastError());
         return FALSE;
    }


    ZeroMemory(&Target, sizeof(Target));
    phe = NULL;
    Addr = inet_addr(TargetName);
    if (Addr == INADDR_NONE)
    {
        phe = gethostbyname(TargetName);
        if (phe == NULL)
        {
            printf("Unknown host %s.\n", TargetName);
            return FALSE;
        }
    }

    if (phe != NULL)
        CopyMemory(&Target.sin_addr, phe->h_addr, phe->h_length);
    else
        Target.sin_addr.s_addr = Addr;

    if (phe != NULL)
        Target.sin_family = phe->h_addrtype;
    else
        Target.sin_family = AF_INET;

    TargetIP = inet_ntoa(Target.sin_addr);
    CurrentSeqNum = 1;
    SentCount = 0;
    LostCount = 0;
    MinRTT.QuadPart = 0;
    MaxRTT.QuadPart = 0;
    SumRTT.QuadPart = 0;
    MinRTTSet       = FALSE;
    return TRUE;
}

/* Close socket */
static VOID Cleanup(VOID)
{
    if (IcmpSock != INVALID_SOCKET)
        closesocket(IcmpSock);

    WSACleanup();
}

static VOID QueryTime(PLARGE_INTEGER Time)
{
    if (UsePerformanceCounter)
    {
        if (QueryPerformanceCounter(Time) == 0)
        {
            /* This should not happen, but we fall
               back to GetCurrentTick() if it does */
            Time->u.LowPart  = (ULONG)GetTickCount();
            Time->u.HighPart = 0;

            /* 1 tick per millisecond for GetCurrentTick() */
            TicksPerMs.QuadPart = 1;
            /* GetCurrentTick() cannot handle microseconds */
            TicksPerUs.QuadPart = 1;

            UsePerformanceCounter = FALSE;
        }
    }
    else
    {
        Time->u.LowPart  = (ULONG)GetTickCount();
        Time->u.HighPart = 0;
    }
}

static VOID TimeToMsString(LPSTR String, LARGE_INTEGER Time)
{
    CHAR          Convstr[40];
    LARGE_INTEGER LargeTime;

    LargeTime.QuadPart = Time.QuadPart / TicksPerMs.QuadPart;

    _i64toa(LargeTime.QuadPart, Convstr, 10);
    strcpy(String, Convstr);
    strcat(String, "ms");
}

/* Locate the ICMP data and print it. Returns TRUE if the packet was good,
   FALSE if not */
static BOOL DecodeResponse(PCHAR buffer, UINT size, PSOCKADDR_IN from)
{
    PIPv4_HEADER      IpHeader;
    PICMP_ECHO_PACKET Icmp;
    UINT              IphLength;
    CHAR              Time[100];
    LARGE_INTEGER     RelativeTime;
    LARGE_INTEGER     LargeTime;
    CHAR              Sign[2];

    IpHeader = (PIPv4_HEADER)buffer;

    IphLength = IpHeader->IHL * 4;

    if (size  < IphLength + ICMP_MINSIZE)
    {
#ifndef NDEBUG
        printf("Bad size (0x%X < 0x%X)\n", size, IphLength + ICMP_MINSIZE);
#endif /* !NDEBUG */
        return FALSE;
    }

    Icmp = (PICMP_ECHO_PACKET)(buffer + IphLength);

    if (Icmp->Icmp.Type != ICMPMSG_ECHOREPLY)
    {
#ifndef NDEBUG
        printf("Bad ICMP type (0x%X should be 0x%X)\n", Icmp->Icmp.Type, ICMPMSG_ECHOREPLY);
#endif /* !NDEBUG */
        return FALSE;
    }

    if (Icmp->Icmp.Id != (USHORT)GetCurrentProcessId())
    {
#ifndef NDEBUG
        printf("Bad ICMP id (0x%X should be 0x%X)\n", Icmp->Icmp.Id, (USHORT)GetCurrentProcessId());
#endif /* !NDEBUG */
        return FALSE;
    }

    if (from->sin_addr.s_addr != Target.sin_addr.s_addr)
    {
#ifndef NDEBUG
        printf("Bad source address (%s should be %s)\n", inet_ntoa(from->sin_addr), inet_ntoa(Target.sin_addr));
#endif /* !NDEBUG */
        return FALSE;
    }

    QueryTime(&LargeTime);

    RelativeTime.QuadPart = (LargeTime.QuadPart - SentTime.QuadPart);

    if ((RelativeTime.QuadPart / TicksPerMs.QuadPart) < 1)
    {
        strcpy(Sign, "<");
        strcpy(Time, "1ms");
    }
    else
    {
        strcpy(Sign, "=");
        TimeToMsString(Time, RelativeTime);
    }


    printf("Reply from %s: bytes=%d time%s%s TTL=%d\n", inet_ntoa(from->sin_addr),
      size - IphLength - (int)sizeof(ICMP_ECHO_PACKET), Sign, Time, IpHeader->TTL);
    if (RelativeTime.QuadPart < MinRTT.QuadPart || !MinRTTSet)
    {
        MinRTT.QuadPart = RelativeTime.QuadPart;
        MinRTTSet = TRUE;
    }
    if (RelativeTime.QuadPart > MaxRTT.QuadPart)
        MaxRTT.QuadPart = RelativeTime.QuadPart;

    SumRTT.QuadPart += RelativeTime.QuadPart;

    return TRUE;
}

/* Send and receive one ping */
static BOOL Ping(VOID)
{
    INT                 Status;
    SOCKADDR            From;
    INT                 Length;
    PVOID               Buffer;
    UINT                Size;
    PICMP_ECHO_PACKET   Packet;

    /* Account for extra space for IP header when packet is received */
    Size   = DataSize + 128;
    Buffer = GlobalAlloc(0, Size);
    if (!Buffer)
    {
        printf("Not enough free resources available.\n");
        return FALSE;
    }

    ZeroMemory(Buffer, Size);
    Packet = (PICMP_ECHO_PACKET)Buffer;

    /* Assemble ICMP echo request packet */
    Packet->Icmp.Type     = ICMPMSG_ECHOREQUEST;
    Packet->Icmp.Code     = 0;
    Packet->Icmp.Id       = (USHORT)GetCurrentProcessId();
    Packet->Icmp.SeqNum   = htons((USHORT)CurrentSeqNum);
    Packet->Icmp.Checksum = 0;

    /* Calculate checksum for ICMP header and data area */
    Packet->Icmp.Checksum = Checksum((PUSHORT)&Packet->Icmp, sizeof(ICMP_ECHO_PACKET) + DataSize);

    CurrentSeqNum++;

    /* Send ICMP echo request */

    FD_ZERO(&Fds);
    FD_SET(IcmpSock, &Fds);
    Timeval.tv_sec  = Timeout / 1000;
    Timeval.tv_usec = Timeout % 1000;
    Status = select(0, NULL, &Fds, NULL, &Timeval);
    if ((Status != SOCKET_ERROR) && (Status != 0))
    {

#ifndef NDEBUG
        printf("Sending packet\n");
        DisplayBuffer(Buffer, sizeof(ICMP_ECHO_PACKET) + DataSize);
        printf("\n");
#endif /* !NDEBUG */

        Status = sendto(IcmpSock, Buffer, sizeof(ICMP_ECHO_PACKET) + DataSize,
            0, (SOCKADDR*)&Target, sizeof(Target));
        QueryTime(&SentTime);
        SentCount++;
    }
    if (Status == SOCKET_ERROR)
    {
        if (WSAGetLastError() == WSAEHOSTUNREACH)
            printf("Destination host unreachable.\n");
        else
            printf("Could not transmit data (%d).\n", WSAGetLastError());
        GlobalFree(Buffer);
        return FALSE;
    }

    /* Expect to receive ICMP echo reply */
    FD_ZERO(&Fds);
    FD_SET(IcmpSock, &Fds);
    Timeval.tv_sec  = Timeout / 1000;
    Timeval.tv_usec = Timeout % 1000;

    do {
        Status = select(0, &Fds, NULL, NULL, &Timeval);
        if ((Status != SOCKET_ERROR) && (Status != 0))
        {
            Length = sizeof(From);
            Status = recvfrom(IcmpSock, Buffer, Size, 0, &From, &Length);

#ifndef NDEBUG
            printf("Received packet\n");
            DisplayBuffer(Buffer, Status);
            printf("\n");
#endif /* !NDEBUG */
        }
        else
            LostCount++;
        if (Status == SOCKET_ERROR)
        {
            if (WSAGetLastError() != WSAETIMEDOUT)
            {
                printf("Could not receive data (%d).\n", WSAGetLastError());
                GlobalFree(Buffer);
                return FALSE;
            }
            Status = 0;
        }

        if (Status == 0)
        {
            printf("Request timed out.\n");
            GlobalFree(Buffer);
            return TRUE;
        }

    } while (!DecodeResponse(Buffer, Status, (PSOCKADDR_IN)&From));

    GlobalFree(Buffer);
    return TRUE;
}


/* Program entry point */
int main(int argc, char* argv[])
{
    UINT Count;
    CHAR MinTime[20];
    CHAR MaxTime[20];
    CHAR AvgTime[20];

    Reset();

    if ((ParseCmdline(argc, argv)) && (Setup()))
    {

        printf("\nPinging %s [%s] with %d bytes of data:\n\n",
            TargetName, TargetIP, DataSize);

        Count = 0;
        while ((NeverStop) || (Count < PingCount))
        {
            Ping();
            Count++;
            if((NeverStop) || (Count < PingCount))
                Sleep(Timeout);
        };

        Cleanup();

        /* Calculate avarage round trip time */
        if ((SentCount - LostCount) > 0)
            AvgRTT.QuadPart = SumRTT.QuadPart / (SentCount - LostCount);
        else
            AvgRTT.QuadPart = 0;

        /* Calculate loss percent */
        Count = SentCount ? (LostCount * 100) / SentCount : 0;

        if (!MinRTTSet)
            MinRTT = MaxRTT;

        TimeToMsString(MinTime, MinRTT);
        TimeToMsString(MaxTime, MaxRTT);
        TimeToMsString(AvgTime, AvgRTT);

        /* Print statistics */
        printf("\nPing statistics for %s:\n", TargetIP);
        printf("    Packets: Sent = %d, Received = %d, Lost = %d (%d%% loss),\n",
            SentCount, SentCount - LostCount, LostCount, Count);
        /* Print approximate times or NO approximate times if 100% loss */
        if ((SentCount - LostCount) > 0)
        {
            printf("Approximate round trip times in milli-seconds:\n");
            printf("    Minimum = %s, Maximum = %s, Average = %s\n",
                MinTime, MaxTime, AvgTime);
        }
    }
    return 0;
}

/* EOF */