Wireshark · Ethereal-dev: [ethereal-dev] Question on sendto with PF_PACKET and SOCK_RAW.

[Ben Greear <greearb@xxxxxxxxxxxxxxx>]

I can't seem to find any documentation anywhere on this....

I want to use the new PF_PACKET and SOCK_RAW options to create
a socket that I can send raw ethernet frames on.  SOCK_PACKET
was working ok for me, but it's deprecated, evidently, and
it wasn't working on eth8, so I figured it was time to upgrade...

Also, using SIOCGIFINDEX, looking for eth1, gives me '3', when the
only interfaces shown by ifconfig -a are eth0, eth1, and lo (in that order).
Is that correct?

Here is the code that tries to create the socket:

This method seems to work...
int createPacketSocket(const char* dev_name, int ether_type, int dev_idx) {
   int s = socket(PF_PACKET, SOCK_RAW, htons(ether_type));
   int r; //retval

   if (s < 0) {
      cerr << "ERROR: socket:  " << strerror(errno) << endl;
      return s;
   }

   struct sockaddr_ll myaddr;

	// From the man 7 packet       man page.
   memset(&myaddr, '\0', sizeof(myaddr));
   myaddr.sll_family = AF_PACKET;
   myaddr.sll_protocol = htons(ether_type);
   myaddr.sll_ifindex = dev_idx;
   //strcpy(myaddr.sa_data, dev_name);

   r = bind(s, (struct sockaddr*)(&myaddr), sizeof(myaddr));
   if (r < 0) {
      cerr << "ERROR: bind:  " << strerror(errno) << endl;
      return r;
   }

   nonblock(s);
   return s;
}

sendto gives this error every time: sendto:  Invalid argument
To send I use this:
int foo::sendPktTo(int dev_socket, const char* dev, const char* msg,
                   int msg_len) {
   int r = 0;

   struct sockaddr from;
   memset(&from, 0, sizeof(from));
   from.sa_family = AF_INET;
   strcpy(from.sa_data, dev);
      
   r = sendto(dev_socket, msg, msg_len, 0, &from, fromlen);
   if (r < 0) {
      VLOG << "ERROR: foo::sendto:  " << strerror(errno) << endl;
   }
   return r;
}//sendTo

Any help will be greatly appreciated...

Thanks,
Ben

-- 
Ben Greear (greearb@xxxxxxxxxxxxxxx)  http://www.candelatech.com
Author of ScryMUD:  scry.wanfear.com 4444        (Released under GPL)
http://scry.wanfear.com               http://scry.wanfear.com/~greear