dabba: print socket program on 'capture get'.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: fix test step title.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: add t1100 unit test related files.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: use capture socket filter parameters.

This feature is extremely practical to filter out traffic which is
generated during the test and account exactly for the test traffic.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: compare sock filter output vs input file.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: add tool to count packets in a pcap.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
doc: add socket filter function doxygen headers.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
dabbad: constify socket filter function prototypes.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
dabbad: improve protobuf sock filter msg asserts.

If the sock filter message has a non-zero length but the array of
pointers is not allocated, something is fishy.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
dabba: refactor sock filter parser return path.

This refactoring makes the sock filter parser return proper error code
and a single return statement.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: fix result pcap name for sock filter tests.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
test: fix expected amount of captured packets.

Each ICMP request will be captured once as its transmitted, once when it
is received. Same for the ICMP response.
This means that each ping will generate 4 packets. As the test moves
formward after 10, 40 packets must be captured.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>