Problem using sendto(...) with packet sockets?

I tried the code below and while sendto(...) sends the data contained
in buf, the 'to' address seems to be ignored. As a consequence the
source and destination addresses + the packet type are taken to be the
first 14 bytes of buf, resulting in a gibberish message. What's up?
---jski

struct sockaddr_ll to;
int tolen;
char buf[ 512 ];

if ( ( s = socket( PF_PACKET, SOCK_RAW, htons( ETH_P_ALL ) ) ) ==
-1 )
{
fprintf( stderr, "Line: %i, socket error: %s\n", __LINE__,
strerror( errno ) );
}

memset( &to, 0, sizeof( to ) );
for ( i = 0; i < 6; i++ ) to.sll_addr[ i ] = 0xff;
to.sll_family = AF_PACKET;
to.sll_ifindex = ifr.ifr_ifindex;
to.sll_protocol = GEOCAST;
tolen = sizeof( to );

for ( i = 0; i < 512; i++ ) buf[ i ] = (unsigned char) i;

size = sendto( s, buf, 512, 0, (const struct sockaddr *)&to,
tolen );