This commit adds support for parsing SCTP packets and converting them
to strings. Currently only chunks, parameters and error causes specified
in RFC 4960 are supported. Support for other RFCs will be added in the
future.
Tested on FreeBSD (amd64 and arm) and Linux.

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

Add some UDPLite tests.

with the other patches.

This commit adds support for UDPLite as specified in RFC 3828
and the corresponding socket options.
It is tested on FreeBSD 10.1 and Linux, the platforms supporting
UDPLite.

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

This patch makes sure that all heaaders start at a four byte
boundary. This is done by not having the ethernet header, which
is 14 bytes long, in the packet buffer.
This fixes the remote mode for platforms having strict alignment
restrictions, like ARM. Without this patch you can't use the remote
mode on a Rasperry Pi running FreeBSD.
This patch has been tested on Linux (Intel) in local and remote mode
and one FreeBSD (Intel and ARM) in local and remote mode.

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

When using libpcap, the function packet_socket_receive was ignoring the
direction. If there were inbound packets sniffed the following try to
read the packet from the tun descriptor blocked.
This patch makes packet_socket_receive aware of the direction and therefore
the libpcap implementation has the same functionality as the Linux one.
It just uses two pcap handles, one for each direction.

Tested on FreeBSD.

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

This commit adds support for the following SCTP socket options:
* SCTP_RTOINFO
* SCTP_INITMSG
* SCTP_NODELAY
* SCTP_MAXSEG
* SCTP_DELAYED_SACK
* SCTP_MAX_BURST

Tested on Linux and FreeBSD. NetBSD and OpenBSD doen't support
SCTP and should not be affected.

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

This commit get the declaration and definition of the parse_mpls()
function in-line. Make it static.

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

This patch fixes two issues:
* It only makes sense to report errno if a system call has actually
  failed.
* You can't call strerror() two times in printf(), since it might
  use a single static buffer.

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

This commit makes sure that the udp length is verified in
host byte order.

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

In local mode, read the outbound packets from the tun device.

A recent Linux patch "tcp: avoid retransmits of TCP packets hanging in
host queues" means that TCP behavior now depends on whether and when
the network device (tun device here) consumes the packets. We now read
all these packets so that the kernel can exercise its normal code
paths for packet transmit completion.

An alternative approach would be to set the tun txqueuelen to 0, but
this would impact qdisc behavior. It is more realistic, and has fewer
side-effects, to make sure the network device has a non-zero queue
length, but packets are still consumed.

Change-Id: Ia922994d4eeea12e61d7876b4c4ef34bc9cef34e

Fix the packet header location calculations in packet_append_header()
forgot to account for the fact that there might be layer 2 headers.

Remote mode has been broken since the addition of encapsulation
support, partly due to this issue.

Change-Id: Idfb0670da8799e11fe1b72771ed13d52d8e991fe

packet_buffer_to_string() needs to accont for the fact that
packet->ip_bytes does not capture the full length of the packet (in
remote mode there will be layer 2 ethernet headers as well).

Change-Id: If2c95e68071545a27078141b6ba5f98cd2c46fb9

Fix wire_server_netdev_receive() to reflect the fact that in remote
mode the server is sniffing packets that are inbound (whereas in local
mode we are sniffing *outbound* packets).

This was a bug introduced in "net-test: packetdrill encap
support: refactor packet receive loops into one loop".

Remote mode has been broken since the addition of encapsulation
support, partly due to this issue.

Change-Id: Ia92f70f48ae90cb2e089ee51d728473a12c63595

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

Handle ICMPv4 and ICMPv6 parsing separately. Return PACKET_BAD if IP and
ICMP versions mismatch.

Signed-off-by: Mike Neilsen <mneilsen@acm.org>
Signed-off-by: Neal Cardwell <ncardwell@google.com>

Add a little helper for accessing the inner-most header of a
packet. In preparation for a patch to support parsing ICMP packets on
the wire.

This patch adds the missing end of table marker in the platform_symbols_table
for FreeBSD.

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

This commit adds support for the CRC32C checksum used by SCTP.
Also add a unit-test for it.

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

Fixed typos in the 'usage' message: a few ']' were missing

Signed-off-by: Matthieu Baerts <matttbe@gmail.com>

Fixes "make tests" on FreeBSD/arm.

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

The --dry_run command line flag causes packetdrill to verify command
line args, load and parse the given script, but not execute it. If any
errors are found during these steps, packetdrill will print an error
as before.  Otherwise, it will exit(0) and produce no output.

Change-Id: Ibf4502c6ea326539346a58b58d7feb29d4b3da69

Test the code to parse on-the-wire MPLS label stacks.

Change-Id: I21884aa720de3c3319636b7391827b54049de574

Test code to print on-the-wire MPLS label stacks in a human-readable
format matching the script syntax.

Change-Id: I7e5d0d8d07490fee1fb744bbd03804bb12e22ae4

Code to verify that the outbound on-the-wire MPLS label stacks from
the kernel under test match those from the script.

Change-Id: Ib7e4e4dc04cdd8d760c8099948f7cdda7973202a

Code to print MPLS label stacks in a human-readable format matching
the script syntax:

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

Change-Id: I706be8aab089fbad79eabde67125345330728517

Code to parse on-the-wire packets using an encapsulation layer that is an
MPLS label stack.

Change-Id: I62585d491303cd8bd85c8afe5b652c4f1be572d9

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