wircd (ircu2.10-based IRC daemon)

wircd is a fork of the Undernet IRC daemon ircu2.10. It provides a full IRC server with P10 server-link support, classic client and operator command handling, multiple scalable event engines, optional TLS backends, and runtime-configurable behavior through feature settings.

Table of contents

• Overview
• Compatibility
• Quick start
• First-time bring-up (practical)
• Implemented functionality
• Command coverage
• Operations and maintenance
• Platform-specific notes
• Documentation and references
• Repository structure
• Historical notes
• License

Overview

At a glance

• Protocol family: P10 (server-to-server)
• Upstream lineage: ircu2.10.12
• Repository patch level: 19+wircd(1.0)
• Configuration format: block-based ircd.conf syntax (see doc/example.conf)
• Build system: autotools-style (configure + make)

Legacy highlights from ircu2.10.12

Historical upstream notes for ircu2.10.12 highlight three major improvements that remain relevant in this code line:

• Rewritten network event subsystem with asynchronous poller support.
• Runtime-tunable features (F: lines / Feature) via GET/SET.
• P10 account propagation behavior to improve service continuity across netsplits.

Compatibility

• This codebase includes feature work derived from nefarious and snircd.
• User account handling is intended to remain compatible with snircd account semantics used by services integrations.
• Server-to-server compatibility is limited to P10-speaking peers.
• Some protocol/runtime features are only fully available between ircu2.10.12-compatible implementations.
• Compatibility statements in this repository are behavioral targets and should be validated in your own deployment topology (services, link peers, policy).

Quick start

1) Build

./configure
make
make install

2) Prepare configuration

• Use doc/example.conf as your baseline template.
• Create/adjust runtime ircd.conf (server name, numerics, classes, client/server blocks, operators, feature toggles).
• If migrating from old 2.10.11 style config, use convert-conf.

3) Run

• Start the daemon with your configured paths/environment.
• Verify listener and startup behavior using logs and basic IRC checks: /LUSERS, /MAP, /STATS, /VERSION.

First-time bring-up (practical)

Recommended sequence for a safe first deployment:

1. Derive a minimal configuration from doc/example.conf.
2. Enable only listeners, base classes, and one operator account.
3. Start the daemon and check logs for parser/bind errors.
4. Connect with an IRC client and validate /LUSERS, /VERSION, /STATS.
5. Add server-link blocks and optional features only after baseline validation.
6. Validate feature changes incrementally via GET/SET.

Implemented functionality

Capabilities are implemented in ircd/ and declared in include/.

Core server runtime

• Connection accept/listen lifecycle
• Packet parsing and send/receive queueing
• Server registration and relay logic
• DNS resolver subsystem
• Memory and utility layers (ircd_alloc, snprintf/string helpers)
• Hash/list management for runtime objects (clients/channels/state)

Event engine support

Platform-oriented polling backends:

• select
• poll
• epoll
• kqueue
• /dev/poll

TLS and crypto

Build-dependent TLS providers:

• OpenSSL
• GnuTLS
• libtls
• no-TLS stub

Runtime TLS functionality:

• TLS listener ports via listener/port configuration
• TLS-enabled server links (CONF_CONNECT_TLS)
• Optional peer certificate fingerprint checks for server links
• Configurable CA/cipher defaults through features (TLS_CACERTFILE, TLS_CACERTDIR, TLS_CIPHERS, TLS_ALLOW_SELFSIGNED, TLS_BURST_FINGERPRINT)

Credential/hash helpers:

• Multiple oper password mechanisms
• MD5 helpers
• Password generation utility (umkpasswd)

IRCv3 support (implemented)

Client capability negotiation and tag parsing are implemented.

Currently advertised/implemented IRCv3 capabilities (feature-gated):

• account-notify
• away-notify
• chghost
• echo-message
• extended-join
• invite-notify
• message-tags
• sasl

Related command support includes CAP, AUTHENTICATE (SASL flow), and TAGMSG for message-tags capable clients.

Identity and policy controls

• Host hiding/cloaking support
• IP validation and checking
• Silence lists
• G-line and jupe handling
• Runtime feature toggles (doc/readme.features)

Operations and maintenance

Upgrade notes

• The repository ships migration tooling for older configs (convert-conf).
• Upstream RELEASE.NOTES documents semantic/config changes across versions.

Build and toolchain notes

• Preferred toolchain: GNU make + gcc (see INSTALL)
• Inspect build options with ./configure --help
• Event engine and TLS availability depend on platform and build configuration

Performance tuning (general)

• Use high-scale pollers (epoll, kqueue, /dev/poll) where available.
• Tune file descriptor and kernel/network limits for expected load.
• Keep DNS resolvers low-latency/nearby for high connect rates.
• Prefer lean, dedicated hosts for large populations.

Time synchronization (critical)

Clock drift between IRC servers can cause severe protocol and operational issues. Run time synchronization (ntpd or equivalent modern NTP service) on all servers.

Information hiding defaults

Legacy ircu2.10.12 behavior defaults to hiding selected information from non-operator users (historically HIS defaults). Override via ircd.conf feature controls if your policy differs.

Troubleshooting (quick entry points)

• Build/config issues: INSTALL
• Feature behavior: doc/readme.features
• Server/network behavior: doc/features.txt, doc/readme.*

Platform-specific notes

Linux

• Linux 2.6+ supports epoll, which scales much better than classic poll loops.
• Ensure user/global descriptor limits are high enough for expected concurrency.

FreeBSD

• Use kqueue where available for improved event-loop performance.
• Typical boot-time tuning examples from legacy notes:

sysctl -w kern.maxfiles=16384
sysctl -w kern.maxfilesperproc=16384
sysctl -w net.inet.tcp.rfc1323=1
sysctl -w net.inet.tcp.delayed_ack=0
sysctl -w net.inet.tcp.restrict_rst=1
sysctl -w kern.ipc.maxsockbuf=2097152
sysctl -w kern.ipc.somaxconn=2048

• Additional historical guidance referenced maxusers, NMBCLUSTERS and ICMP tuning for very high-scale systems.

Solaris

• Use /dev/poll on supported releases for better scalability than poll().
• Legacy /etc/system examples for descriptor limits:

set rlim_fd_max = 16384
set rlim_fd_cur = 8192

• On older Solaris 7 environments, /dev/poll required vendor patching per historical documentation.

Documentation and references

Primary configuration references

• doc/example.conf — canonical configuration template
• doc/readme.features — runtime feature toggles (Feature/F-line behavior)
• doc/readme.iauth — external authorization protocol
• doc/snomask.html — server notice mask behavior

Recommended configuration workflow

1. Start from a minimal leaf-style config.
2. Validate listener, client class and operator access.
3. Add server-link blocks and hub/leaf policy carefully.
4. Enable optional features incrementally and monitor effects.

Documentation map

• Build/install process: INSTALL
• Release changes: RELEASE.NOTES
• Feature matrix and numerics: doc/features.txt
• Runtime feature switches: doc/readme.features
• Base configuration template: doc/example.conf

Repository structure

• ircd/ — daemon core, command handlers, protocol, engines, TLS backends
• include/ — headers, feature declarations, protocol definitions
• doc/ — configuration examples and operator/admin documentation
• tests/ — test-related assets
• tools/ — helper utilities/scripts
• patches/ — optional patch material and references

Historical notes

Operational sections in this document are adapted from upstream ircu2.10.12 materials (including platform tuning guidance authored in 2002). Treat numeric values and OS-specific commands as historical baselines and validate against modern OS documentation before production use.

License

See LICENSE in the repository root.