lib: Update FRCP implementation

2026-05-20T06:17:07+00:00

The Flow and Retransmission Control Protocol (FRCP) runs end-to-end between two peers over a flow. It provides reliability, in-order delivery, flow control, and liveness. Note that congestion avoidance is orthogonal to FRCP and handled in the IPCP. A fixed 16-octet header, network byte order, is prefixed to every FRCP packet: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | flags | hcs | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | window | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | seqno | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ackno | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | payload (variable) ... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ hcs is a CRC-16-CCITT-FALSE checksum over the PCI (and the stream extension when present), verified before any flag-driven dispatch. A single packet can simultaneously carry DATA + ACK + FC + RXM by OR-ing flag bits. An optional CRC trailer covers the body on DATA when qs.ber == 0, and on every SACK packet; an optional AEAD wrap (per-flow keys) sits outermost. Flag bits (MSB-first; bits 13..15 reserved, MUST be zero): +------+--------+--------+----------------------------------------+ | Bit | Mask | Name | Meaning | +------+--------+--------+----------------------------------------+ | 0 | 0x8000 | DATA | Carries caller payload | | 1 | 0x4000 | DRF | Start of a fresh data run | | 2 | 0x2000 | ACK | ackno field valid | | 3 | 0x1000 | NACK | Pre-DRF nudge (seqno informational) | | 4 | 0x0800 | FC | window field valid (rwe advertisement) | | 5 | 0x0400 | RDVS | Rendezvous probe (window-closed) | | 6 | 0x0200 | FFGM | First Fragment of a multi-fragment SDU | | 7 | 0x0100 | LFGM | Last Fragment of a multi-fragment SDU | | 8 | 0x0080 | RXM | Retransmission | | 9 | 0x0040 | SACK | Block list follows in payload | | 10 | 0x0020 | RTTP | RTT probe / echo (payload follows) | | 11 | 0x0010 | KA | Keepalive | | 12 | 0x0008 | FIN | End of stream marker | | 13-15| -- | -- | Reserved (MUST be zero) | +------+--------+--------+----------------------------------------+ (FFGM, LFGM) encodes the fragment role of a DATA packet (SCTP-style B/E): 11=SOLE, 10=FIRST, 00=MID, 01=LAST. Each fragment carries its own seqno; Retransmission recovers fragments individually, reassembly runs at consume time. In stream mode FFGM/LFGM are unused; per-byte position is carried by the stream extension below and end-of-stream is signalled by FIN on a 0-byte DATA packet. SACK payload (FRCT_ACK | FRCT_FC | FRCT_SACK): 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | n_blocks | padding (2 octets) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | start[0] | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | end[0] | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ... n_blocks pairs total ... Each block describes a *present* (received) range strictly above the cumulative ACK in the PCI ackno. D-SACK (RFC 2883) is signalled in-band as block[0] - no flag bit, no extra framing - and consumed by the RACK reo_wnd_mult scaler (RFC 8985 sec. 7.2). RTTP payload (FRCT_RTTP only; 24 octets): 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | probe_id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | echo_id | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + nonce (16 octets, echoed verbatim) + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Stream PCI extension (in_order == STREAM only; 8 octets after the base PCI on every DATA packet): 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | start | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | end | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ start, end are monotonic 32-bit byte offsets; end - start equals the on-wire payload length. Stream mode is negotiated at flow allocation; the extension is present iff stream mode is in use, never on a per-packet basis. Service modes are an orthogonal (in_order, loss, ber) vector selected at flow_alloc; the cubes above map to the axes: +----------------+---------+------+-----+-----------------------+ | Cube | in_order| loss | ber | Engaged | +----------------+---------+------+-----+-----------------------+ | qos_raw | 0 | 1 | 1 | Raw passthrough | | qos_raw_safe | 0 | 1 | 0 | Raw + CRC trailer | | qos_rt | 1 | 1 | 1 | FRCP, no FRTX, no CRC | | qos_rt_safe | 1 | 1 | 0 | FRCP, no FRTX, CRC | | qos_msg | 1 | 0 | 0 | FRCP + FRTX | | qos_stream | 2 | 0 | 0 | FRCP + FRTX, stream | +----------------+---------+------+-----+-----------------------+ in_order=0 sends raw datagrams with no PCI (UDP-equivalent); in_order=1 engages FRCP with SDU framing; in_order=2 (stream) requires loss=0 and is rejected otherwise. loss=0 engages the FRTX retransmit machinery. ber=0 appends the CRC-32 trailer; QOS_DISABLE_CRC at build time forces ber=1 for development. Encryption is a separate per-flow attribute layered as an AEAD wrap outside the FRCP packet. Heritage: delta-t (Watson 1981) supplies timer-based connection management - no SYN/FIN handshake, the DRF marker, the t_mpl / t_a / t_r timers. RINA (Day 2008) supplies the unified flow_alloc(name, qos, ...) primitive and the orthogonal QoS-cube axes. Loss detection follows TCP/QUIC practice (RFCs 2018, 2883, 6582, 6298, 8985); RTT probing is nonce-authenticated like QUIC PATH_CHALLENGE. Adds oftp, a minimal file-transfer tool over an FRCP stream flow. The client reads from stdin or --in FILE and writes through a flow_alloc(qos_stream); the server (--listen) calls flow_accept and writes to stdout or --out FILE. Both sides compute a CRC-64/NVMe over the bytes they handle and print the result. The server rejects flows whose negotiated qs.in_order != STREAM. Two FRCP knobs are exposed via env vars on either side: OFTP_FRCT_RTO_MIN fccntl FRCTSRTOMIN (ns) OFTP_FRCT_STREAM_RING_SZ fccntl FRCTSRRINGSZ (octets) The ocbr_client gains an OCBR_QOS env var to pick the cube the client uses for flow_alloc; recognised values are raw, safe, rt, rt_safe, msg, stream. Unknown values fall back to raw with a warning on stderr. Without the env set behaviour is unchanged. Removes the deprecated lib/timerwheel.c Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

tools: Use distinct exit codes

2026-05-20T06:17:04+00:00

The tools will now use the following convention: 0 — success 1 — runtime/I/O failure or packet loss 2 — setup failure oping now uses a SIGALRM to exit on duration tests. 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

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

irmd: Initial Flow Allocation Protocol Header

2025-07-23T13:07:52+00:00

This adds the initial version for the flow allocation protocol header between IRMd instances. This is a step towards flow authentication. The header supports secure and authenticated flow allocation, supporting certificate-based authentication and ephemeral key exchange for end-to-end encryption. id: 128-bit identifier for the entity. timestamp: 64-bit timestamp (replay protection). certificate: Certificate for authentication. public key: ECDHE public key for key exchange. data: Application data. signature: Signature for integrity/authenticity. Authentication and encryption require OpenSSL to be installed. The IRMd compares the allocation request delay with the MPL of the Layer over which the flow allocation was sent. MPL is now reported by the Layer in ms instead of seconds. Time functions revised for consistency and adds some tests. The TPM can now print thread running times in Debug builds (TPM_DEBUG_REPORT_INTERVAL) and abort processes with hung threads (TPM_DEBUG_ABORT_TIMEOUT). Long running threads waiting for input should call tpm_wait_work() to avoid trigger a process abort. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update licenses to 2024

2024-01-13T09:20:14+00:00

Slow but steady. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update copyright to 2023

2023-02-13T20:10:10+00:00

2022 was a rather slow year... Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

2022-04-03T16:01:02+00:00

Growing pains. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

tools: Fix return value on error in ocbr

2022-03-03T11:00:54+00:00

The ocbr tool was returning 0 on error. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib, ipcpd, irmd: Wrap pthread unlocks for cleanup

2021-06-23T06:36:48+00:00

This add an ouroboros/pthread.h header that wraps the pthread_..._unlock() functions for cleanup using pthread_cleanup_push() as this casting is not safe (and there were definitely bad casts in the code). The close() function is now also wrapped for cleanup in ouroboros/sockets.h. This allows enabling more compiler checks. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

ouroboros/src/tools/ocbr, branch be