compiles, where some other system header #defines sc_sp.
In gre_ioctl, GREDSOCK case, do not try to delete sc_fp if it is
NULL.
Move GREDSOCK and GRESSOCK definitions to where the other GRE ioctls
are defined.
Remove #ifdef GRESSOCK, it's unnecessary now that the feature is
complete.
Fix MOBILE encapsulation. Add many debugging printfs (mainly
concerning UDP mode). Clean up the gre(4) code a bit. Add the
capability to setup UDP tunnels to ifconfig. Update documentation.
In UDP mode, gre(4) puts a GRE header onto transmitted packets,
and hands them to a UDP socket for transmission. That is, the
encapsulation looks like this: IP+UDP+GRE+encapsulated packet.
There are two ways to set up a UDP tunnel. One way is to tell the
source and destination IP+port to gre(4), and let gre(4) create
the socket. The other way to create a UDP tunnel is for userland
to "delegate" a UDP socket to the kernel.
Don't copy ttl from the inner packet to the encapsulating packet. Make
the outer ttl sysctl'able. This should close PR 14269 from Jasper Wallace
(change partly from there) and it makes traceroute work over gre tunnels.
