ouroboros/cmake, branch be

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

build: Remove deprecated cmake options

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

RXM_BUFFER_ON_HEAP and SSM_POOL_BLOCKS were no longer used. 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

build: Add a 'tags' target for ctags index generation

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

The build will now detect presence of ctags, and allows generating a tags file with 'make tags' for convenience. 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

lib: Fix and clean up crc implementation

2026-05-06T07:05:08+00:00

Fixes detection of PMULL on aarch64 without crypto extensions. Adds a crc64_nvme_step helper function in CRC64 to avoid code duplication and cleans up the comments. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

cmake: Add CPU feature detection helper

2026-05-06T07:04:22+00:00

Add cmake/utils/CPUUtils.cmake providing detect_cpu_feature() plus detect_pclmul() and detect_pmull() that compile-test for x86 PCLMULQDQ+SSE4.1 and aarch64 FEAT_PMULL respectively. This will be useful for hardware accelerated CRC64/NVMe integrity checks. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

irmd: Allow direct rbuff between local processes

2026-02-22T15:02:16+00:00

This allows bypassing the IPCP for local processes that share the same packet pool, lowering latency between processes to comparable levels as Unix sockets (RTT in the order of a microsecond). For local processes, no IPCPs are needed: $ irm b prog oping n oping $ oping -l Ouroboros ping server started. New flow 64. Received 64 bytes on fd 64. The direct IPC can be disabled with the DISABLE_DIRECT_IPC build flag. Note that this is needed for rumba 'local' experiments to emulate network topologies. Without this flag all processes will just communicate directly. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders