From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate001.proxmox.com (gate001.proxmox.com [IPv6:2a0f:8001:1:32::40]) by lore.proxmox.com (Postfix) with ESMTPS id 0A4001FF0C0 for ; Wed, 04 Nov 2026 17:02:04 +0100 (CET) Received: from gate001.proxmox.com (localhost.localdomain [127.0.0.1]) by gate001.proxmox.com (Proxmox) with ESMTP id 83BC52167D; Wed, 04 Nov 2026 17:01:26 +0100 (CET) From: Hannes Laimer To: pve-devel@lists.proxmox.com Subject: [PATCH proxmox v7 0/6] add proxmox-ebpf library Date: Wed, 4 Nov 2026 17:00:59 +0100 Message-ID: <20261104160105.2184145-1-h.laimer@proxmox.com> X-Mailer: git-send-email 2.47.3 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1793808069119 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.303 Adjusted score from AWL reputation of From: address DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment (newer systems) RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: W2PIRHFJ2FMUMGIZIADRRWMT7VQZQF6S X-Message-ID-Hash: W2PIRHFJ2FMUMGIZIADRRWMT7VQZQF6S X-MailFrom: h.laimer@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: proxmox-ebpf holds the eBPF programs and the code that loads, attaches and updates them, grouped into subsystems. It is a library only, whoever needs a subsystem pulls in just that one through a cargo feature and calls it from their side. This series is the shared part, the actual subsystems come as their own series on top. The core is the shared subsystem code. It takes care of everything from loading and attaching per interface to pinning in bpffs and tearing down again. So nothing has to keep running, and each call picks up where the last one left off. The build records a hash of the compiled object, the crate's version and a schema version per subsystem, so a call can tell what changed and an older build leaves a newer one's state alone. A changed program or map schema is swapped onto the existing links without interrupting traffic. The new maps are filled before the links move onto them. The BPF C code is also built natively against a small shim, so the parsing and packet building logic can be tested without a kernel. Packaging is debcargo like the other Rust crates. Every change runs under a lock per subsystem, a full apply takes it exclusively and a single-interface step shared, like the pmxcfs domain locks. The holder reads the input of its change under the lock and writes before it lets go. So a change and a full apply reach the kernel in the order they read their input, and nothing has to order them after the fact. A holder that never returns makes the waiters time out instead of hanging them. A subsystem can also hand over the whole content of its maps. The programs then move onto the new content one link at a time and never read a mix of old and new entries, and a write the kernel refuses leaves the old content in place. The programs of different subsystems on one interface run in a fixed order. An attach places its link relative to the links the other subsystems already hold there, so the order holds however the attaches are timed, and an update keeps every link in its place. The crate goes into the proxmox workspace, as the first one there with a build script. Building needs clang-21, libbpf-dev and proxmox-kernel-libc-dev, the programs compile against the UAPI headers from there. v7: * include rust pkg version next to fingerprint, so we can avoid flip-flopping the loaded programs in case a worker stays around during/after an upgrade * differentiate between a link swap failing on open or on the swap itself * replacing the maps and clearing take the lock guard mutably, so a map ref opened before cannot be written after the exchange, it would hit the retired map * the repair after an interrupted replacement also detaches the links of a direction the update dropped, a retry that failed afterwards left them attached * add context to io errors * merge a run order change, don't blindly replace, this covers cases where something was added and reordered in one v6: * loop all links at the start of every replace, moving links to live/ is done one-by-one, so it can fail. a failed pass then has some links still on staging/, this makes sure we dont delete state that may still be attached. the kernel checks if it already exists on a swap, so this is a no-op, and at worst an atomic swap for links that still has staging/ attached * only allow adding to the run order, at least for live updates. removal or re-orders are applied on the next reboot * enforce that map refs live as long as the lock they were taken under * a pin that cannot be opened stays and fails the step instead of being unlinked, which under a descriptor shortage detached a working link * the harness tests run a C program of their own against the shim * move the crate into the proxmox workspace, the vendored vmlinux.h is gone, the programs build against the UAPI headers of proxmox-kernel-libc-dev with a versioned clang v5: * add a call that replaces the maps as a whole, it uses more space and writes everything instead of only what changed, but leaves the old content in place instead of a mix, in cases where the write fails with ENOMEM. Subsystems choose which they need * install/upgrade now also use this newly added replace path, this simplifies the process and also closes a hole where attached programs would read empty maps, shortly before they were filled after a schema version bump * the run order of the subsystems is written to `/run/proxmox-ebpf/order` by a full apply and every attach places by it, so a stale process running an older version attaches correctly against subsystems added by a process running a newer version * set correct permissions on `/run/..` * a build whose schema is older than the pinned one no longer counts its state as current, so its single steps back off as well * add `interrupted()` on the lock guard, true when a replacement left its staged set or an old schema directory behind, a full pass replaces then * an attach checks after attaching that the interface still has the index of its pin, one recreated under the same name in between is reported as gone * a map missing from a pinned set is reported by name v4, thanks @Stefan!: * drop the generation counter, a change takes the apply lock before it reads its input instead, so the lock order is the input order * new, the links of different subsystems on an interface are now ordered * the tc link plumbing is its own commit ahead of the subsystem code * subsystem programs are now a list of direction and name pairs * add short note for why not proxmox-sys's locking * improve tc error handling * fix smaller spacing and code stuff proxmox: Hannes Laimer (6): ebpf: add the crate with its BPF build ebpf: tc: add the link plumbing ebpf: subsystem: add the shared tc program handling ebpf: subsystem: place subsystem links in a fixed order ebpf: tests: add a native harness for the BPF C programs ebpf: debian: package the crate as a Rust library Cargo.toml | 2 + proxmox-ebpf/Cargo.toml | 22 + proxmox-ebpf/build.rs | 190 +++ proxmox-ebpf/debian/changelog | 5 + proxmox-ebpf/debian/control | 50 + proxmox-ebpf/debian/copyright | 18 + proxmox-ebpf/debian/debcargo.toml | 13 + proxmox-ebpf/include/bpf_debug.h | 12 + proxmox-ebpf/src/bpf-shim/bpf/bpf_helpers.h | 34 + proxmox-ebpf/src/bpf-shim/bpf_debug.h | 10 + proxmox-ebpf/src/bpf-shim/linux/bpf.h | 25 + proxmox-ebpf/src/lib.rs | 6 + proxmox-ebpf/src/subsystem.rs | 1373 +++++++++++++++++++ proxmox-ebpf/src/tc.rs | 326 +++++ proxmox-ebpf/tests/bpf/fixture.bpf.c | 37 + proxmox-ebpf/tests/common/mod.rs | 211 +++ proxmox-ebpf/tests/harness.rs | 84 ++ 17 files changed, 2418 insertions(+) create mode 100644 proxmox-ebpf/Cargo.toml create mode 100644 proxmox-ebpf/build.rs create mode 100644 proxmox-ebpf/debian/changelog create mode 100644 proxmox-ebpf/debian/control create mode 100644 proxmox-ebpf/debian/copyright create mode 100644 proxmox-ebpf/debian/debcargo.toml create mode 100644 proxmox-ebpf/include/bpf_debug.h create mode 100644 proxmox-ebpf/src/bpf-shim/bpf/bpf_helpers.h create mode 100644 proxmox-ebpf/src/bpf-shim/bpf_debug.h create mode 100644 proxmox-ebpf/src/bpf-shim/linux/bpf.h create mode 100644 proxmox-ebpf/src/lib.rs create mode 100644 proxmox-ebpf/src/subsystem.rs create mode 100644 proxmox-ebpf/src/tc.rs create mode 100644 proxmox-ebpf/tests/bpf/fixture.bpf.c create mode 100644 proxmox-ebpf/tests/common/mod.rs create mode 100644 proxmox-ebpf/tests/harness.rs Summary over all repositories: 17 files changed, 2418 insertions(+), 0 deletions(-) -- Generated by murpp 0.12.0