From a syslog perspective it does not make sense to log fatal and
warn with the same severity. Switch log_warn() to LOG_ERR and keep
fatal() at LOG_CRIT.
OK reyk@ florian@

work on making log.c similar in all daemons:

move daemon-local functions into new logmsg.c, and reduce
the (mostly whitespace) differences so that log.c's can be diffed easily.

removal of log_rtmsg() aproved by claudio@

ok claudio@ krw@

Improve logging of sent and received messages.

* Standardize the logging format of sent and received messages:
"msg-[in|out]: message type: lsr-id A.B.C.D [additional info]";

* Log sent label messages as well, not only the received ones;

* Move the logging of sent notification messages from
send_notification_nbr() to send_notification_full(), this way notification
triggered by the lde process are logged as well;

* Minor clean-up.

Use exit(3) instead of _exit(2) in the child processes.

Since recently the child processes call exec() after fork(), so they should
stop using _exit(2) and use exit(3) instead when shutting down.

Ok claudio@

Normalize the received prefixes.

We need to use ldp_applymask() to normalize the received
prefixes. Example: 10.1.1.0/16 -> 10.1.0.0/16.

Additionally, stop using IANA's AF numbers in map->fec.prefix.af and use
AF_INET/AF_INET6 instead. This makes the code much simpler, use AF_IPV[46]
only when necessary (decoding/encoding prefixes).

ok claudio@

Improve logging of reserved labels.

Print "exp-null" and "imp-null" instead of "0" and "3", for example. Also,
remove print_label() and print_pw_type() from ldpctl.c and use the
equivalent functions from ldpd's log.c.

While here, be more paranoid and use UINT32_MAX instead of UINT_MAX
for NO_LABEL.

More renaming and whitespace cleanup.

No binary change after "strip -s".

Remove superfluous includes.

Make functions and variables static whenever possible.

The benefits of this include:
* clean up of the ldpd global namespace;
* improved readability;
* more hints to the compiler/linker to generate more efficient code.

Whenever possible, move global static variables to a smaller scope
(function).

All extern variables are now declared in header files to avoid unnecessary
duplication.

This patch also cleans up the indentation of all function prototypes
and global variables.

Add support for IPv6 (RFC 7552).

This includes:
* Full compliance to RFC 7552;
* Support for MD5 on LDPov6 sessions;
* Support for pseudowires over IPv6 LSPs (we're probably the world's
first implementation doing this);
* Support for the IPv6 explicit-null label;
* Knob to specify the prefered address-family for TCP transport
connections;
* Knob to use cisco non-compliant format to send and interpret the
Dual-Stack capability TLV.

Assorted fixes and small cleanup.

Nothing really interesting here.

Create network sockets on the parent process.

We drop our privileges in ldpe right after we create the network sockets.
The problem is that we might want to change the transport-address and
reload the config, in which case we need new sockets. To allow that,
always create the network sockets in the parent process and pass them
to ldpe via imsg.

Fix mess caused by my commit script.

I screwed up everything... trying to fix now.

Rework L2VPN code.

Standardize some log messages and fix some inconsistencies.

We were using several different names for the same thing in our log
messages: neighbor, neighbor ID, nbr ID and LSR ID.

Standardize to always use "lsr-id" to refer to a neighbor.

Also:
* Use log_warnx() instead of log_warn() when appropriate;
* Use fatal(x) instead of err(x) when appropriate;
* Fix some inconsistent log messages.

Rename a few constants to avoid confusion.

In ldpd we have the map structure, which is used to represent a label message,
and the fec structure, used to store FECs in the LIB.

As of now, ldpd supports two type of FECs:
* IPv4 prefix (FEC_TYPE_IPV4);
* PWID (FEC_TYPE_PWID).

For the label messages, the following contants were being used:
* FEC_WILDCARD;
* FEC_PREFIX (IPv4 or IPv6);
* FEC_PWID.

Since these contants have similar names to the previous ones, rename
them to:
* MAP_TYPE_WILDCARD;
* MAP_TYPE_PREFIX;
* MAP_TYPE_PWID.

Move some code around.

This patch doesn't introduce any logical change.

Fix logging of wildcard label mappings.

If snprintf fails, a value less than 0 is returned.

Replace manually written function names with __func__.

VPLS signaling support.

This patch introduces full support for pseudowire signaling in ldpd(8),
including Control Word and Status TLV negotiation.

As of now it's not possible to configure a VPWS, but the signaling is
the same. In the future, when VPWS support is available in the kernel,
ldpd(8) can be extended to support VPWS with only a few modifications.

Limitations:
* No support for FEC 129, only FEC 128 (more widely deployed);
* No support for group withdraws (not widely deployed);
* No support for MAC withdraws (not widely deployed).

Related RFCs:
* RFC 3916: Requirements for Pseudo-Wire Emulation Edge-to-Edge (PWE3)
* RFC 3985: Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture
* RFC 4385: Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for
Use over an MPLS PSN
* RFC 4446: IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)
* RFC 4447: Pseudowire Setup and Maintenance Using the Label Distribution
Protocol (LDP)
* RFC 4448: Encapsulation Methods for Transport of Ethernet over MPLS
Networks
* RFC 4905: Encapsulation Methods for Transport of Layer 2 Frames over
MPLS Networks
* RFC 4906: Transport of Layer 2 Frames Over MPLS

ok claudio@

Rework label mapping algorithms to be more in line with the RFC.

This patch presents a thoroughly review of the label mapping
algorithms. Most of the changes are minor bug fixes in the handling of
received label messages.

Additional improvements:
* Add a few more references to the Appendix A of the RFC5036 ("LDP
Label Distribution Procedures") into the code;
* Add full multipath support;
* Send label withdraws when appropriate;
* Add label withdraw/release wildcard support.

NOTE: As a result of implementing only the "Liberal Label Retention" and
"Downstream Unsolicited" modes, we will never send a label request
("Request Never"). And that means that we can ignore the following
notification messages: "Label Request Aborted", "No Label Resources",
"No Route" and "Label Resources Available". The following algorithms
mentioned in the RFC can also be ignored: "Timeout of Deferred Label
Request", "Detect Local Label Resources Have Become Available" and
"Receive Label Abort Request".

Now, considering that we only support one combination of all modes of
operation, we can say that we have an almost complete implementation of
the protocol.

ok claudio@

Convert the logic in yyerror(). Instead of creating a temporary
format string, create a temporary message.
OK claudio@

Implement support for adjacencies and targeted hellos
Refactor adjacencies out of the neighbor handling so that it is possible to
have more complex topologies with targeted sessions.
From Renato Westphal

Filter out route messages we don't need and log kernel messages in
super verbose mode.
From Renato Westphal

Don't allow enabling LDP on loopback and carp interfaces.
LDP should be allowed only on physical or tunnel interfaces.
Diff by Renato Westphal

Decouple log_verbose() from log_init() so the verbose flag stays set with
"-v" (previously only "-vd" worked). Similar to recent ospfd commit.
ok claudio@

NBR_STA_SESSION, NBR_STA_UP, and NBR_STA_ACTIVE represent all the same
group of states (all but NBR_STA_DOWN). Clean up this confusion and remove
NBR_STA_UP and NBR_STA_ACTIVE.
OK michele@

No need to print FEC twice. Remove it in the log function.

Move the logging of FEC changes to the LDE and print the FEC and label
information. This is more useful.
OK michele

Remove some more ospfd-ism from the interface code. This time remove
of most of the IF_TYPE_ special cases and most interface types.
Point-to-point and broadcast still present because of find_iface()
which needs addtional fixing.
OK michele@

Log recieved notifications in a human understanable way. Makes debugging
a bit easier.
OK michele@

Cleanup the interface FSM by removing most of the ospfd specific states
that have nothing to do with LDP.
OK michele@

More IMSG_CTL_LOG_VERBOSE, still doing the same toggeling of log_debug().

Welcome ldpd, the Label Distribution Protocol daemon.
Built using the imsg/three process framework, its main aim
is to redistribute MPLS labels between peers.

Right now it has some really basic functionalities,
the basic protocol works and peers are able to exchange
labels and insert them in the kernel.
It still does not react to changes of topology.

Not yet connected to the builds.

ok claudio@ deraadt@