Code to parse script packets using an encapsulation layer that is an
MPLS label stack.

The syntax looks like:

  mpls (label 123, tc 1, [S], ttl 255) (label 456, tc 1, [S], ttl 255)

This is borrowed from the syntax from tcpdump, which is:

  MPLS (label 123, exp 1, [S], ttl 255) (label 456, exp 1, [S], ttl 255)

We use "tc" because RFC 5462 renamed the EXP ("experimental") field to
the TC ("traffic class") field. We use lower-case "mpls" instead of
"MPLS" for consistency with other packetdrill protocols, and for ease
of typing.

Change-Id: I2e797aead8605da9fe3f0461594cf7273d4ef0ec

Basic code for filling in MPLS headers and appending them to packets.

Change-Id: Id31ef8e97de3e9b95c3b05ff42aade6a3d8490a5

Basic definitions for reading and writing MPLS label stacks.

Change-Id: I4190b816082fe57a6cbececfee368aabeab57daa

The big endian folks would also need a recursion_control field too,
now wouldn't they?

Change-Id: Ie535241873d3a576d76993e14a803319e3c07250

Allow the --remote_ip config parameter to be a prefix, not just a
single address. The entire remote prefix is routed to the tun device
or remote packetdrill machine.

The goal here is to all tests to use more than one remote IP. The
immediate motivation is testing GRE, where there is a remote IP for
the TCP endpoint and a separate remote IP for the GRE decapsulator.
But eventually we'll also want to allow testing multiple concurrent
TCP connections from multiple remote IPs addresses as well.

Here are examples of the remote prefix you get for various values of
the --remote_ip field. These are chosen for convenience and backwards
compatibility with existing tests that are already using the
--remote_ip parameter.

o Default:

configuration                      remote prefix
------------------------------     -----------------
IPv4, no --remote_ip            -> 192.0.2.0/24   (default)
v4/6, no --remote_ip            -> 192.0.2.0/24   (default)
IPv6, no --remote_ip            -> 2001:DB8::0/32 (default)

o Explicit IP without prefix length (prefix includes all bits):

configuration                      remote prefix
------------------------------     -----------------
IPv4 --remote_ip=10.248.0.3     -> 10.248.0.3/32
v4/6 --remote_ip=10.248.0.3     -> 10.248.0.3/32
IPv6 --remote_ip=2001:db8::3    -> 2001:db8::3/128

o Explicit with prefix length:

configuration                      remote prefix
------------------------------     -----------------
IPv4 --remote_ip=10.248.0.3/16  -> 10.248.0.0/16
v4/6 --remote_ip=10.248.0.3/16  -> 10.248.0.0/16
IPv6 --remote_ip=2001:db8::3/16 -> 2001::0/16

Change-Id: Ibc95c3419d66bcf1bbfd8a1fc7650d0003345ef2

The goal here is to be able to route a prefix of user-configurable
size over the tun device or to the remote packetdrill server, so that
tests can use more than one remote IP. The immediate motivation is
testing GRE, where there is a remote IP for the TCP endpoint and a
separate remote IP for the GRE decapsulator.

Change-Id: I36b7025a242c3803802087c91d284a41c62ca1bd

packetdrill already supported an inet_addr() as a part of a sockaddr
expression (since that's how strace represents the sockaddr argument
to connect(), for example). But now we also want to allow a
stand-alone inet_addr() call, to allow the specification of IP
addresses for other contexts.

Change-Id: Ia69751030eff399e6b0d9cbb4a15530f0b721278

To allow hexadecimal integers with the most significant bit set to be
passed as system call parameters, we need to broaden the set of values
acceptable to get_s32() to include u32.

If this proves confusing, then at some point in the future we could
rename this to be get_32() or something.

Change-Id: I416f80f8c135306c6b64de8b700186d0b9a005c7

Properly recognize hex integers.

Change-Id: I23b002e06ec21a445e66e82d47e72a65071b9a01

Tests for basic support of printing encapsulation headers.

Change-Id: I2a3e743db44493cb8b338943ab40fc96d9abf63c

Add simple coverage of IP/GRE encapsulation parsing.

Change-Id: I5938edc521a387e0c72bbf547d2862077f6af204

Basic support for printing encapsulation headers: IPv4, IPv6, GRE.


Change-Id: I67b9e432c98a00ba2c19ac6ea25ea35592462ea9

Add support for IPv6 in encapsulation layers, including: lexical
scanning of IPv6 addresses, parsing IPv6 encap in scripts, appending
and filling in IPv6 encapsulation.


Change-Id: I1349cd4056c168a4114a92324eb2a321f7db7697

When we sniff an unknown packet, free it and allocate another packet
at the top of the sniffing loop. Previously we were not clearing state
after parsing an unknown packet, so state from the unkbown packet
could linger on, co-mingling with state from the next sniffed packet.


Change-Id: Ia9a330766969b114fd6084a087ff3f0d6b11d9d4

Factor out the packet sniffing loop that's common to local and remote
mode, since it is nearly identical in both cases. This is in
preparation for fixing a bug that is found in both loops, so we can
make the fix in just one place.


Change-Id: Ic9a9b84b66a9f812866b1e29cd7c897f7c1d40cf

Basic verification for outbound encapsulated packets from the kernel
under test.


Change-Id: I5efeb08fb262312ec85d257680e4df46829a38f0

Add code for basic parsing of GRE v0 headers, per RFC 1701.


Change-Id: I0d564f3ef17132f94a1df76512409b4cee7b441f

The main engine for handling encapsualted packets in packetdrill,
including:

- parsing scripts with encapsulation
- parsing packets with encapsulation
- injecting packets with encapsulation

Encapsulated packets look like the following, which has an IP header,
GRE header, and then regular IP/TCP header:

+0 > ipv4 1.1.1.1 > 2.2.2.2: gre: . 1:1001(1000) ack 1

See other patches in the series for more detailed examples.


Change-Id: Ia8c7580e268f5b0347bd9d3fdc73b096f751a79d

Basic definitions to support GRE-encapsulated packets.


Change-Id: I9c3158d17577c54c3298a65667976a7edab9c184

As a first step for packetdrill supporting encapsulated packets,
introduce types to represent all the layers of headers in a packet.


Change-Id: I617a6b977d4fc1f6a51b1b0211dc2c3b39cc2738

Signed-off-by: Mike Neilsen <mneilsen@acm.org>

Signed-off-by:  <tuexen@fh-muenster.de>

Rewrite an if conditional that clang complained about on FreeBSD 10.x.

Signed-off-by: Neal Cardwell <ncardwell@google.com>

For example, FreeBSD 10.0 beta 3 default installation does not have a
"gcc".

Signed-off-by: Neal Cardwell <ncardwell@google.com>

Ignore .o and ~ files.

Signed-off-by: Neal Cardwell <ncardwell@google.com>

FreeBSD 10.x has fmemopen in libc, so check __FreeBSD_version and set
defines appropriately.

fmemopen(3) states that buffers opened via open_memstream should be
freed after closing the associated stream.

Signed-off-by: Mike Neilsen <mneilsen@acm.org>

Adds initial batch of packetdrill tests that have been confirmed to pass on
stock (Ubuntu) Linux 3.11.0-rc4.

Signed-off-by: Barath Raghavan <barath@google.com>

Initial commit for the packetdrill network stack testing tool:

  https://code.google.com/p/packetdrill/



Signed-off-by: Neal Cardwell <ncardwell@google.com>