RAW Socket - Ethertype and receive's algorithm - C

Question

I'm working with raw socket in C language. I need to send and to receive a raw ethernet packet. The packet should start with an IEEE 802.3 header:

MAC DST [0-5] - MAC SRC [6-11] - ETH TYPE[12-13]

Catching the packets with wireshark I see the following structure:

MAC DST [0-5] - MAC SRC [6-11] - LENGTH[12-13] - TRAILER[14-58]-....

This is my code:

...
sraw = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_802_3));
...
retVal = setsockopt(sraw, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
...
val = 3;
retVal = setsockopt(sraw, SOL_SOCKET, SO_PRIORITY, &val, sizeof (val));
...
memcpy(ptr_eth_header->DstMac, dst_mac, 6);
memcpy(ptr_eth_header->SrcMac, src_mac, 6);
ptr_eth_header->Type = htons(ETH_P_802_3);
memcpy(buffer + ETHHDR_SIZE, data, 60);
...
sockaddr.sll_family = htons(PF_PACKET);
sockaddr.sll_protocol = htons(ETH_P_802_3);
sockaddr.sll_ifindex = ifr.ifr_ifru.ifru_ivalue;
sockaddr.sll_halen = 6;
memcpy(&(sockaddr.sll_addr), dst_mac, 6);
...
bytes = sendto(sraw, buffer, sizeof(buffer), 0, (struct sockaddr *) &(sockaddr), sizeof (struct sockaddr_ll));

Is it just a wireshark's "problem"? Any ideas?

My second problem is about the receipt of the raw messages. The process is stuck on the recvfrom.

This is my code:

sraw = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_802_3));
...
retVal = setsockopt(sraw, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr));
...
val = 3;
retVal = setsockopt(sraw, SOL_SOCKET, SO_PRIORITY, &val, sizeof (val));
...
val = CLIENT_PACKET_SIZE;
retVal = setsockopt(sraw, SOL_SOCKET, SO_RCVBUF, &val, sizeof (val));

sockaddr.sll_family    = htons(PF_PACKET);
sockaddr.sll_ifindex   = ifr.ifr_ifindex;
sockaddr.sll_protocol  = htons(ETH_P_802_3);

buffer = malloc(CLIENT_PACKET_SIZE * sizeof(char));
while (count < PACKET_COUNT) {
    bytes = recvfrom(sraw, buffer, CLIENT_PACKET_SIZE, 0, (struct sockaddr *)&sockaddr, (socklen_t*)sizeof(sockaddr));
    ...
}

Could you help me?

Thanks in advance!

Answer 1

I found the response about my first question: I use Ethertype == 0x0001 instead EtherType >= 0x0600

http://www.cavebear.com/archive/cavebear/Ethernet/type.html

What about the second question? What's wrong with my code?