mcastv3.cpp

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//
// Sample: IP Source Multicasting (requires IGMPv3)
//
// Files:
//      mcastv3.cpp     - this file
//      resolve.cpp     - common routine for resolving host name and addresses
//      resolve.h       - header file for common routines
//
// Description:
//    This sample illustrates IP multicasting using source multicasting.
//    IP source multicasting is implemented on the wire via the IGMPv3 and
//    is currently supported only on Windows XP. This sample allows you to
//    specify one or more source addresses to include or exclude from the
//    multicast group. By default, the mode is to include the given sources.
//    If the -x paramter is specified then the list of sources is the list
//    of sources to exclude traffic from.
//
//    Remember that setting a IP multicast source filter only affects from
//    what sources data is accepted from. It does not prevent the app from
//    sending to that source.
//
// Compile:
//    cl -o mcastv3.exe mcastv3.cpp resolve.cpp ws2_32.lib
//
// Command Line Options/Parameters
//    mcastws1.exe [-s] [-m str] [-p int] [-i str] [-b str] [-l] [-n int] [...]
//       -b str    Local interface to bind to
//       -c        Connect to multicast address before sending?
//       -f        Use SIO_SET_MULTICAST_FILTER instead
//       -h str    Source (host) address (may be specified multiple times)
//       -i str    Local interface to use for the multicast join
//       -j        Don't join the multicast group (sender option)
//       -l 0/1    Disable the loopback 
//       -m str    Dotted decimal IP multicast address to join
//       -n int    Number of messages to send or receive
//       -p int    Port number to use
//       -s        Act as sender; otherwise receive data
//       -t        Set multicast TTL
//       -x        Switch to exclude (default is include)
//       -z        Size of send/recv buffer
//
#include <winsock2.h>
#include <ws2tcpip.h>
#include <windows.h>

#include "resolve.h"

#include <stdio.h>
#include <stdlib.h>

#define MCASTADDRV4    "234.5.6.7"
#define MCASTPORT      "25000"
#define BUFSIZE        1024
#define DEFAULT_COUNT  500
#define DEFAULT_TTL    8

BOOL  bSender=FALSE,            // Act as sender?
      bConnect=FALSE,           // Connect before sending?
      bLoopBack=FALSE,          // Loopback parameter specified?
      bDontJoin=FALSE,          // Sender option - don't join the group before sending
      bUseFilter=FALSE;         // Use SIO_SET_MULTICAST_FILTER instead
int   gSocketType=SOCK_DGRAM,
      gProtocol=IPPROTO_UDP,
      gLoopBack=0,              // Disable loopback?
      gCount=DEFAULT_COUNT,     // Number of messages to send/receive
      gMode=MCAST_INCLUDE,      // Source mode: include or exclude
      gSourceCount=0,           // Number of sources specified
      gTtl=DEFAULT_TTL,         // Multicast ttl value
      gBufferSize=BUFSIZE;      // Size of send/recv buffer
char *gBindAddr=NULL,           // Interface to bind to
     *gInterface=NULL,          // Interface to join on
     *gMulticast=MCASTADDRV4,   // Multicast group to join
     *gPort=MCASTPORT,          // Port number to use
    **gSourceList=NULL;         // List of source IP addresses

// 
// Function: usage
//
// Description:
//    Print usage information and exit.
//
void usage(char *progname)
{
    printf("usage: %s -s -m str -p int -i str -l -n int\n",
        progname);
    printf(" -b str String address to bind to\n");
    printf(" -c     Connect before sending?\n");
    printf(" -f     Use SIO_SET_MULTICAST_FILTER instead\n");
    printf(" -h str Source address\n");
    printf(" -i str Local interface to join groups\n");
    printf("          The default port is: %s\n", MCASTPORT);
    printf(" -j     Don't join the multicast group\n");
    printf(" -l 0/1 Turn on/off loopback\n");
    printf(" -m str Dotted decimal multicast IP addres to join\n");
    printf(" -n int Number of messages to send/receive\n");
    printf(" -p int Port number to use\n");
    printf(" -s     Act as server (send data); otherwise\n");
    printf("          receive data.\n");
    printf(" -t int Set multicast ttl value\n");
    printf(" -x     Switch to exclude mode (default mode is include)\n");
    printf(" -z int Size of send/recv buffer\n");
    ExitProcess(-1);
}

//
// Function: ValidateArgs
//
// Description
//    Parse the command line arguments and set some global flags
//    depeding on the values.
//
void ValidateArgs(int argc, char **argv)
{
    int      hostcount=0,
             rc,
             i;

    // First count how many source IPs are given so we may allocat an array large
    //    enough to hold them
    for(i=1; i < argc ;i++)
    {
        if (tolower(argv[i][1]) == 'h')
            hostcount++;
    }
    gSourceList = (char **)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(char *) * hostcount);
    if (gSourceList == NULL)
    {
        fprintf(stderr, "ValidateArgs: HeapAlloc failed: %d\n", GetLastError());
        ExitProcess(-1);
    }
    // Now process the commands
    for(i=1; i < argc ;i++)
    {
        if ((argv[i][0] == '-') || (argv[i][0] == '/'))
        {
            switch (tolower(argv[i][1]))
            {
                case 'b':        // Address to bind to
                    if (i+1 >= argc)
                        usage(argv[0]);
                    gBindAddr = argv[++i];
                    break;
                case 'c':        // Connect socket
                    bConnect = TRUE;
                    break;
                case 'f':        // Use SIO_SET_MULTICAST_FILTER instead
                    bUseFilter = TRUE;
                    break;
                case 'h':        // Source (host) address
                    if (i+1 >= argc)
                        usage(argv[0]);
                    gSourceList[gSourceCount++] = argv[++i];
                    break;
                case 'i':        // local interface to use
                    if (i+1 >= argc)
                        usage(argv[0]);
                    gInterface = argv[++i];
                    break;
                case 'j':       // Don't join multicast group
                    bDontJoin = TRUE;
                    break;
                case 'l':        // Disable loopback?
                    if (i+1 >= argc)
                        usage(argv[0]);
                    bLoopBack = TRUE;
                    gLoopBack = atoi(argv[++i]);
                    break;
                case 'm':        // multicast group to join
                    if (i+1 >= argc)
                        usage(argv[0]);
                    gMulticast = argv[++i];
                    break;
                case 'n':        // Number of messages to send/recv
                    if (i+1 >= argc)
                        usage(argv[0]);
                    gCount = atoi(argv[++i]);
                    break;
                case 'p':        // Port number to use
                    if (i+1 >= argc)
                        usage(argv[0]);
                    gPort = argv[++i];
                    break;
                case 's':        // sender
                    bSender = TRUE;
                    break;
                case 'x':        // Switch mode to exclude
                    gMode = MCAST_EXCLUDE;
                    break;
                case 'z':        // Sizeo of send receive buffer
                    if (i+1 >= argc)
                        usage(argv[0]);
                    gBufferSize = atol(argv[++i]);
                    break;
                default:
                    usage(argv[0]);
                    break;
            }
        }
    }
    return;
}

//
// Function: JoinMulticastGroup
//
// Description:
//    This routine joins the multicast group for the given sources. If the mode
//    is include (and we're not using SIO_SET_MULTICAST_FILTER) then 
//    IP_ADD_SOURCE_MEMBERSHIP is used on each source. If the mode is exclude
//    (and SIO_SET_MULTICAST_FILTER is not specified) then we join the group like
//    normal (using IP_ADD_MEMBERSHIP) and then we drop each of the source IPs
//    given using IP_DROP_MEMBERSHIP. On the other hand if SIO_SET_MULTICAST_FILTER
//    is specified (via the -f option), we simply use the ioctl in a one shot
//    does everything call.
//
int JoinMulticastGroup(SOCKET s, struct addrinfo *group, struct addrinfo *iface)
{
    struct addrinfo *ressrc=NULL;
    int              rc,
                     i;

    rc = NO_ERROR;

    if (bUseFilter == FALSE)
    {
        struct ip_mreq        mreqv4;
        struct ip_mreq_source mreqv4src;

        if (gMode == MCAST_INCLUDE)
        {
            // If the mode is include, call IP_ADD_SOURCE_MEMBERSHIP for each source.
            //    In this sample we only add sources but in a more dynamic environment
            //    you could remove sources that were previously added by calling
            //    IP_DROP_SOURCE_MEMBERSHIP.
            for(i=0; i < gSourceCount ;i++)
            {
                mreqv4src.imr_multiaddr = ((SOCKADDR_IN *)group->ai_addr)->sin_addr;
                mreqv4src.imr_interface = ((SOCKADDR_IN *)iface->ai_addr)->sin_addr;

                // Resolve the source IP
                ressrc = ResolveAddress(gSourceList[i], "0", group->ai_family, group->ai_socktype, group->ai_protocol);
                if (ressrc == NULL)
                {
                    fprintf(stderr, "JoinMulticastGroup: Unable to resolve address: %s\n",
                            gSourceList[i]);
                    continue;
                }

                mreqv4src.imr_sourceaddr = ((SOCKADDR_IN *)ressrc->ai_addr)->sin_addr;

                // Add the source membership
                rc = setsockopt(
                        s,
                        IPPROTO_IP,
                        IP_ADD_SOURCE_MEMBERSHIP,
                        (char *)&mreqv4src,
                        sizeof(mreqv4src)
                        );
                if (rc == SOCKET_ERROR)
                {
                    fprintf(stderr, "JoinMulticastGroup: setsockopt: IP_ADD_SOURCE_MEMBERSHIP failed: %d\n",
                            WSAGetLastError());
                }
                else
                {
                    printf("ADD SOURCE: ");
                    PrintAddress(ressrc->ai_addr, ressrc->ai_addrlen);
                    printf(" for GROUP: ");
                    PrintAddress(group->ai_addr, group->ai_addrlen);
                    printf(" on INTERFACE: ");
                    PrintAddress(iface->ai_addr, iface->ai_addrlen);
                    printf("\n");
                }

                freeaddrinfo(ressrc);
            }
        }
        else if (gMode == MCAST_EXCLUDE)
        {
            // For exclude mode, we first need to join the multicast group with
            //    IP_ADD_MEMBERSHIP (which sets the mode to EXCLUDE NONE). Afterwhich
            //    we drop those sources that we want to block from membership via the
            //    IP_BLOCK_SOURCE. This sample only drops sources but does not allow
            //    them back into the group. To add back a source that was previously
            //    dropped, you would call IP_UNBLOCK_SOURCE.
            mreqv4.imr_multiaddr = ((SOCKADDR_IN *)group->ai_addr)->sin_addr;
            mreqv4.imr_interface = ((SOCKADDR_IN *)iface->ai_addr)->sin_addr;

            // First join the group (state will be EXCLUDE NONE)
            rc = setsockopt(
                    s,
                    IPPROTO_IP,
                    IP_ADD_MEMBERSHIP,
                    (char *)&mreqv4,
                    sizeof(mreqv4)
                    );
            if (rc == SOCKET_ERROR)
            {
                fprintf(stderr, "JoinMulticastGroup: setsockopt: IP_ADD_MEMBERSHIP failed: %d\n",
                        WSAGetLastError());
                return SOCKET_ERROR;
            }
            else
            {
                printf("JOINED GROUP: ");
                PrintAddress(group->ai_addr, group->ai_addrlen);
                printf(" on INTERFACE: ");
                PrintAddress(iface->ai_addr, iface->ai_addrlen);
                printf("\n");
            }

            // Now drop each source from the group
            for(i=0; i < gSourceCount ;i++)
            {
                mreqv4src.imr_multiaddr = ((SOCKADDR_IN *)group->ai_addr)->sin_addr;
                mreqv4src.imr_interface = ((SOCKADDR_IN *)iface->ai_addr)->sin_addr;

                ressrc = ResolveAddress(gSourceList[i], "0", group->ai_family, group->ai_socktype, group->ai_protocol);
                if (ressrc == NULL)
                {
                    fprintf(stderr, "JoinMulticastGroup: Unable to resolve address: %s\n",
                            gSourceList[i]);
                    continue;
                }

                mreqv4src.imr_sourceaddr = ((SOCKADDR_IN *)ressrc->ai_addr)->sin_addr;

                rc = setsockopt(
                        s,
                        IPPROTO_IP,
                        IP_BLOCK_SOURCE,
                        (char *)&mreqv4src,
                        sizeof(mreqv4src)
                        );
                if (rc == SOCKET_ERROR)
                {
                    fprintf(stderr, "JoinMulticastGroup: setsockopt: IP_BLOCK_SOURCE failed: %d\n",
                            WSAGetLastError());
                }
                else
                {
                    printf("   DROPPED SOURCE: ");
                    PrintAddress(ressrc->ai_addr, ressrc->ai_addrlen);
                    printf("\n");
                }
                freeaddrinfo(ressrc);
            }
        }
    }
    else
    {
        struct ip_msfilter *filter=NULL;
        char               *filterbuf=NULL;
        int                 filterlen=0;
        DWORD               bytes;

        // Otherwise, use the SIO_SET_MULTICAST_FILTER to set all the sources
        //    with one call. First we have to build up a ip_msfilter structure
        //    which contains all the source's IP addresses.

        // calculate the size of the filter buffer necessary
        filterlen = sizeof(struct ip_msfilter) + ((gSourceCount-1) * sizeof(struct in_addr));

        filterbuf = (char *)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, filterlen);
        if (filterbuf == NULL)
        {
            fprintf(stderr, "JoinMulticastGroup: HeapAlloc failed: %d\n",
                    GetLastError());
            ExitProcess(-1);
        }

        filter = (struct ip_msfilter *)filterbuf;

        filter->imsf_multiaddr = ((SOCKADDR_IN *)group->ai_addr)->sin_addr;
        filter->imsf_interface = ((SOCKADDR_IN *)iface->ai_addr)->sin_addr;
        filter->imsf_fmode     = gMode;
        filter->imsf_numsrc    = gSourceCount;

        printf("SETTING MULTICAST FILTER STATE:\n");
        printf("   Multicast address: ");
        PrintAddress(group->ai_addr, group->ai_addrlen);
        printf("\n");
        printf("   Local interface  : ");
        PrintAddress(iface->ai_addr, iface->ai_addrlen);
        printf("\n");
        printf("   Mode is          : %s\n", ((gMode == MCAST_INCLUDE) ? "INCLUDE" : "EXCLUDE"));
        printf("   Source count     : %d\n", gSourceCount);

        // fill in each source address into the structure
        for(i=0; i < gSourceCount ;i++)
        {
            ressrc = ResolveAddress(gSourceList[i], "0", group->ai_family, group->ai_socktype, group->ai_protocol);
            if (ressrc == NULL)
            {
                fprintf(stderr, "JoinMulticastGroup: Unable to resolve source: %s\n",
                        gSourceList[i]);
                break;
            }
            else
            {
                printf("   Source [%d]   : ", i);
                PrintAddress(ressrc->ai_addr, ressrc->ai_addrlen);
                printf("\n");
            }

            filter->imsf_slist[i] = ((SOCKADDR_IN *)ressrc->ai_addr)->sin_addr;

            freeaddrinfo(ressrc);
        }

        // Set the multicast filter state with one call