Refactor packetimpact Connection types

Reorganize the Connection types such that the defined types no longer expose
the lower-level functions SendFrame and CreateFrame. These methods are still
exported on the underlying Connection type, and thus can be accessed via a
type-cast. In future, defined types should have one or more type-safe versions
of the send() method on Connection, e.g. UDPIPv4 has Send() which allows the UDP
header to be overridden and SendIP() which allows both the IPv4 and UDP headers
to be modified.

testbench.Connection gets a SendFrameStateless method which sends frames
without updating the state of any of the layers. This should be used when
sending out-of-band control messages such as ICMP messages, as using the
normal Send method can result in errors when attempting to update the TCP
state using an ICMP packet.

Also remove the localAddr field of testbench.Connection and instead compute
it on the fly as needed for UDPIPv4 and TCPIPv4.

PiperOrigin-RevId: 315969714

0 files changed, 0 insertions, 0 deletions