Now that Conn::set_conn is guaranteed to be called at the beginning and
at the end of the connection, we can skip re-setting the elements that
we know will not have changed. This prevents repeated lookups, e.g. to
check that addresses are in the local networks.
During `connection_state_remove`, only the duration, number of
packets, service, and history fields are updated.
local_orig and local_resp are updated when the connection is flipped. A
test was added for that purpose. It uses the already existing
http.zeek-image-post-1080-8000-x.pcap, which was slightly rewritten for
this, so that one side of the connection has IP addresses different from
127.0.0.1.
The existing history-flip test also was updated to have one side being
in a local-net, to check that the flipping of local_orig and local_resp
works correctly at the beginning of a connection.
When Zeek flips roles of a HTTP connection subsequent to the HTTP analyzer
being attached, that analyzer would not update its own ContentLine analyzer
state, resulting in the wrong ContentLine analyzer being switched into
plain delivery mode.
In debug builds, this would result in assertion failures, in production
builds, the HTTP analyzer would receive HTTP bodies as individual header
lines, or conversely, individual header lines would be delivered as a
large chunk from the ContentLine analyzer.
PCAPs were generated locally using tcprewrite to select well-known-http ports
for both endpoints, then editcap to drop the first SYN packet.
Kudos to @JordanBarnartt for keeping at it.
Closes#3789
