This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
The firewall provides a ProcessPacket handler, and implements an
address-and-port endpoint dependent firewall that allows all
traffic to egress from the trusted interface, and only allows
inbound traffic if corresponding outbound traffic was previously
seen.
Signed-off-by: David Anderson <danderson@tailscale.com>
