Transmit

Sockets

struct vrr_sock
- Members:
  - struct sock *sk: must be first member
  - Source address
  - Destination address
  - Whatever else we need to build a header
vrr_sock(struct sock *sk)
- inline function, just casts sk to vrr_sock
Build vrr_sock in create()
vrr_bind(sk, sockaddr, addr_len)
- Basically, just set the source/destination addr in the sock
- Maybe check to make sure the addr is valid
vrr_sendmsg(iocb, sk, msg, len)
- msg contains an iovec, which points to a bunch of userspace data blocks
- allocate an skb for sending using sock_alloc_send_skb
- maybe in “build_header()”:
  - populate a vrr header struct (make struct vrr_header)
  - use skb_put() to pack the header in the skb’s user data area
- send skb to output function

Net device output

Questions

We should find out where to store a reference to the net device.
Possibly, we should make routing tables based on struct rtable in net/route.h, and extend dst_entry for our routing table entries. This simplifies many things, including providing the net device pointer. There is also a whole bunch of code that will be useless to us, however.