ouroboros/src/ipcpd/config.h.in, branch 0.24.0

ipcpd: Rework congestion avoidance

2026-07-19T09:44:36+00:00

Congestion avoidance is a property of the layer, orthogonal to ARQ and to flow control: FRCP retransmits and lets the peer pace the sender, per flow, end-to-end; the IPCP paces path aggregates. Each signal means one thing: a loss triggers a retransmission, a mark means congestion, the peer window means a slow receiver. Every flow is paced by the same rate law whatever its QoS, so a greedy raw sender shares a bottleneck fairly with a reliable stream. The unit of control is the (destination address, QoS cube) aggregate: all flows toward that destination share one controller and one rate; a start-time fair-queuing pacer divides the rate across them by deadline instead of blocking the send path, and a new flow rides the aggregate's estimates at its current rate, with no probing of its own. Slow start runs once per aggregate. The congestion signal is a multi-bit magnitude: forwarders mark packets with their standing queue depth, MAX-combined across hops, so a packet carries the deepest queue on its path. The receiver feeds back a time-integral mean over a window that adapts to the flow's byte rate, measuring a slow flow with the same fidelity as a fast one. The sender runs AIMD scaled by elapsed wall-clock time, which makes the steady-state allocation RTT-independent. The PCI gains one byte: the path capacity as a quarter-log2 code. Forwarders estimate their egress rate from busy-period drain and MIN-stamp the byte, the receiver returns the window minimum with its feedback, and the sender scales its rate floor and additive slope to the bottleneck (C / 32). A deep cut implies a backlogged bottleneck and a backlogged bottleneck advertises its capacity, so the scaled floor is live exactly when recovery needs it: the probe heals a halving in seconds at any link rate, and the floor bounds the deepest hole to a factor 32 below the bottleneck. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

ipcpd-eth: Tune raw sockets and retry queries

2026-05-20T06:17:06+00:00

Add IPCP_ETH_SNDBUF/RCVBUF cmake build options so deployments can size the AF_PACKET socket buffers without patching code. Drop the O_NONBLOCK fcntl on the raw socket in favour of per-recvfrom MSG_DONTWAIT so race-loser reader threads exit with EAGAIN without spamming the log. Track frame send failures and the SO_SNDBUF size in the eth/summary RIB; log a one-shot warning when the kernel reports AF_PACKET drops. Retry name queries up to NAME_QUERY_RETRIES times within NAME_QUERY_TIMEO; a single lost ARP-style mgmt frame no longer fails the query. Bump IRMd QUERY_TIMEOUT from 200 ms to 2200 ms so the IRMd budget exceeds the new shim retry window. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

irmd: Pass MTU from IPCP to process for FRCT

2026-05-20T06:17:06+00:00

FRCT needs to know the MTU for fragmentation. The MTU is now passed from the layer serving the flow to the process as part of flow allocation. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Rename PROG_* config to PROC_*

2026-05-20T06:17:06+00:00

Per-process flow / fd / fqueue limits are properties of a process, not a program; align the naming. Mechanical rename of PROG_MAX_FLOWS, PROG_RES_FDS, and PROG_MAX_FQUEUES to PROC_*. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

ipcpd: Expose ipcpd-eth flow statistics via RIB

2026-05-20T06:17:05+00:00

Adds an IPCP_ETH_FLOW_STATS cmake option (gated on HAVE_FUSE; default off) exposing per-flow and aggregate frame counters at //eth/{summary,}. Counters use RELAXED atomics; the macros expand to ((void) 0) when the option is off. Per-flow and global counters live in nested stat structs. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update copyright to 2026

2026-02-18T06:54:56+00:00

Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Replace rdrbuff with a proper slab allocator

2026-01-26T06:50:33+00:00

This is a first step towards the Secure Shared Memory (SSM) infrastructure for Ouroboros, which will allow proper resource separation for non-privileged processes. This replaces the rdrbuff (random-deletion ring buffer) PoC allocator with a sharded slab allocator for the packet buffer pool to avoid the head-of-line blocking behaviour of the rdrb and reduce lock contention in multi-process scenarios. Each size class contains multiple independent shards, allowing parallel allocations without blocking. - Configurable shard count per size class (default: 4, set via SSM_POOL_SHARDS in CMake). The configured number of blocks are spread over the number of shards. As an example: SSM_POOL_512_BLOCKS = 768 blocks total These 768 blocks are shared among 4 shards (not 768 × 4 = 3072 blocks) - Lazy block distribution: all blocks initially reside in shard 0 and naturally migrate to process-local shards upon first allocation and subsequent free operations - Fallback with work stealing: processes attempt allocation from their local shard (pid % SSM_POOL_SHARDS) first, then steal from other shards if local is exhausted, eliminating fragmentation while maintaining low contention - Round-robin condvar signaling: blocking allocations cycle through all shard condition variables to ensure fairness - Blocks freed to allocator's shard: uses allocator_pid to determine target shard, enabling natural load balancing as process allocation patterns stabilize over time Maintains existing robust mutex semantics including EOWNERDEAD handling for dead process recovery. Internal structures exposed in ssm.h for testing purposes. Adds some tests (pool_test, pool_sharding_test.c. etc) verifying lazy distribution, migration, fallback stealing, and multiprocess behavior. Updates the ring buffer (rbuff) to use relaxed/acquire/release ordering on atomic indices. The ring buffer requires the (robust) mutex to ensure cross-structure synchronization between pool buffer writes and ring buffer index publication. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Add an option for container compatibility

2026-01-19T07:35:10+00:00

This adds a BUILD_CONTAINER option that disables some features that require elevated privileges like setting thread priorities, which might not be supported in docker environments. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Add post-quantum cryptography support

2026-01-19T07:29:29+00:00

This adds initial support for runtime-configurable encryption and post-quantum Key Encapsulation Mechanisms (KEMs) and authentication (ML-DSA). Supported key exchange algorithms: ECDH: prime256v1, secp384r1, secp521r1, X25519, X448 Finite Field DH: ffdhe2048, ffdhe3072, ffdhe4096 ML-KEM (FIPS 203): ML-KEM-512, ML-KEM-768, ML-KEM-1024 Hybrid KEMs: X25519MLKEM768, X448MLKEM1024 Supported ciphers: AEAD: aes-128-gcm, aes-192-gcm, aes-256-gcm, chacha20-poly1305 CTR: aes-128-ctr, aes-192-ctr, aes-256-ctr Supported HKDFs: sha256, sha384, sha512, sha3-256, sha3-384, sha3-512, blake2b512, blake2s256 Supported Digests for DSA: sha256, sha384, sha512, sha3-256, sha3-384, sha3-512, blake2b512, blake2s256 PQC support requires OpenSSL 3.4.0+ and is detected automatically via CMake. A DISABLE_PQC option allows building without PQC even when available. KEMs differ from traditional DH in that they require asymmetric roles: one party encapsulates to the other's public key. This creates a coordination problem during simultaneous reconnection attempts. The kem_mode configuration parameter resolves this by pre-assigning roles: kem_mode=server # Server encapsulates (1-RTT, full forward secrecy) kem_mode=client # Client encapsulates (0-RTT, cached server key) The enc.conf file format supports: kex= # Key exchange algorithm cipher= # Symmetric cipher kdf= # Key derivation function digest= # Digest for DSA kem_mode= # Server (default) or client none # Disable encryption The OAP protocol is extended to negotiate algorithms and exchange KEX data. All KEX messages are signed using existing authentication infrastructure for integrity and replay protection. Tests are split into base and _pqc variants to handle conditional PQC compilation (kex_test.c/kex_test_pqc.c, oap_test.c/oap_test_pqc.c). Bumped minimum required OpenSSL version for encryption to 3.0 (required for HKDF API). 1.1.1 is long time EOL. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Refactor CMake modules

2026-01-07T09:00:06+00:00

This moves the CMake build logic out of the source tree and splits it up into a more modular form. The tests now have a CMakeLists.txt file in their respective source directory. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders