我正在尝试获取一个简单的多播示例以在Linux上工作(我已经

尝试了RHEL 4 2.6.9和Ubuntu 8.04 2.6.24).总体思路是

我希望服务器绑定到单播地址,然后添加

本身属于组ff02 :: 1.然后,我希望它收到

多播发送到ff02 :: 1.以下代码可在Mac OS X 10.5(适用于

实际上,在OS X上运行的服务器会从Linux发送多播

客户),但我无法使Linux服务器端正常工作.不会

获得任何多播.如果我更改代码以绑定到::(INADDR6_ANY)

而不是单播地址(我尝试了本地链接和全局链接

地址),它确实获得了多播.我想知道是否有人

可以指出我做错了什么.

服务器：

memset( &hint, 0, sizeof( hint ) );

hint.ai_family = AF_INET6;

hint.ai_socktype = SOCK_DGRAM;

// argv[1] is either a link-local or a global address

err = getaddrinfo( argv[1], NULL, &hint, &info );

if( err != 0 ) {

perror( "getaddrinfo" );

exit( 1 );

}

struct sockaddr_in6 * addr = (struct sockaddr_in6*)info->ai_addr;

//addr->sin6_addr = in6addr_any; // if this is uncommented, multicasts are received

addr->sin6_port = htons( 7890 );

s = socket( AF_INET6, SOCK_DGRAM, 0 );

if( bind( s, (struct sockaddr*) addr, info->ai_addrlen ) != 0 ) {

close( s );

perror( "bind" );

exit( 1 );

}

if( getaddrinfo( "ff02::1", NULL, &hint, &multi ) != 0 ) {

close( s );

perror( "getaddrinfo" );

exit( 1 );

}

struct ipv6_mreq mreq;

memset( &mreq, 0, sizeof(mreq) );

memcpy( &mreq.ipv6mr_multiaddr, &((struct sockaddr_in6 *) multi->ai_addr)->sin6_addr, sizeof(mreq.ipv6mr_multiaddr) );

mreq.ipv6mr_interface = 2; // 2 happens to be the interface ID; I've tried other values here

freeaddrinfo( multi );

if( setsockopt( s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq) ) != 0 ) {

close( s );

perror( "IPV6_JOIN_GROUP" );

exit( 1 );

}

for( ; ; ) {

char data[6];

size_t len;

len = recvfrom( s, data, 5, 0, NULL, NULL );

data[5] = '\0';

printf( "Received %s\n", data );

if( strcmp( data, "exitt" ) == 0 ) {

break;

}

}

客户端代码如下：

memset( &hint, 0, sizeof( hint ) );

hint.ai_family = AF_INET6;

hint.ai_socktype = SOCK_DGRAM;

hint.ai_protocol = 0;

err = getaddrinfo( "ff02::1", NULL, &hint, &info );

if( err != 0 ) {

perror( "getaddrinfo" );

return 0;

}

struct sockaddr_in6 * addr = (struct sockaddr_in6*)info->ai_addr;

addr->sin6_port = htons( 7890 );

addr->sin6_scope_id = 2; // 2 happens to be the interface ID

s = socket( AF_INET6, SOCK_DGRAM, 0 );

for( ; ; ) {

char data[6];

size_t len;

scanf( "%5s", data );

data[5] = '\0';

printf( "Sending %s\n", data );

if( sendto( s, data, 5, 0, info->ai_addr, info->ai_addrlen ) != 5 ) {

printf( "Error sending\n" );

}

if( strcmp( data, "exitt" ) == 0 ) {

break;

}

}

close( s );