anyone has any idea on how to fill the sendto() when sending data trough a packet socket in linux? i can recvfrom() though.

---------------(soc)
char pkt[]="...blah..."; // my packet w/ 802.3 header and w/ LLC header
struct sockaddr_ll remote_host;

sd=socket(AF_PACKET,SOCK_RAW,htons(ETH_P_ALL));

bzero(&remote_host, sizeof(struct sockaddr_ll));
remote_host.sll_family = AF_PACKET;
remote_host.sll_ifindex = 2; // eth0
remote_host.sll_halen = ETH_ALEN; // 6 bytes
strcpy(remote_host.sll_addr,"\x00\x50\x56\xc0\x00\x01"); // destination host's mac
// "man packet" says filling only this 4 fields is enough for sending

sendto(sd, pkt, sizeof(pkt), 0, (struct sockaddr*)&remote_host, sizeof(struct sockaddr));
// returns -1 errno = Invalid argument
-------------(eoc)

pkt[] is a stp(spanning tree protocol) packet captured w/ ethereal(copy'ed/paste'd) so
it must be valid. but anyway, does sendto() refuse to send if pkt is ivalid?

i also tryed SOCK_DGRAM and still no luck

thank you in advance.

Take a look at Beej's Guide to Network Programming. http://www.ecst.csuchico.edu/~beej/guide/net/

i could not find any information on this on the net. all there is are some basic tutorials (including beej's guide), not the real stuff anyway. this kind of information(sending on packet sockets) is not present even in Richard Stevens' "UNIX Network Programming Vol 1, 2nd Ed"

this is the kinda stuff u learn from late nights hanging out in /usr/include/net*/*