[bfdsyncd] BFD hardware offload for BGP sessions (patched #4253) by sridhartalari · Pull Request #4676 · sonic-net/sonic-swss

sridhartalari · 2026-06-15T19:32:56Z

Summary

This PR is a patched continuation of #4253, adding bfdsyncd to bridge FRR bfdd with hardware-offloaded BFD sessions managed by BfdOrch.

Review feedback from #4253 and Copilot has been addressed:

Fix GCC 14 / Debian Trixie build failure caused by std::unique_ptr<FILE, decltype(&pclose)> (-Werror=ignored-attributes) by using a custom pipe deleter
Validate remote_discriminator, remote_min_rx, remote_min_tx, and remote_multiplier STATE_DB fields with swss::to_uint<uint32_t>() and reject corrupt rows before sending BFDDP frames
Fix BFDDP state-change header encoding (htons() instead of incorrect ntohs() for length and type)
Fix IPv4 link-local detection (169.254.0.0/16) using host-order comparison
Fix m_sendBuffer leak and set m_connected after accept() for proper socket cleanup
Exit successfully after -h usage flag
Replace reserved __BFDLINK__ header guard with SWSS_BFDLINK_H
Fix garbled license text in bfddp_packet.h
Resolve merge conflict with current master in tests/mock_tests/Makefile.am (keep both tests_fdbsyncd and tests_bfdsyncd)

The delete/recreate approach for timer parameter changes is retained for vendor compatibility, as discussed in #4253.

For background and design details, see the original PR #4253 and HLD sonic-net/SONiC#1599.

Test plan

Build swss on Bookworm (GCC 13) and Trixie (GCC 14.2) slave images
Run make check target tests_bfdsyncd
Verify BGP BFD session add/delete/state-update flows with hardware BFD enabled on a testbed

Signed-off-by: Baorong Liu <96146196+baorliu@users.noreply.github.com>

Signed-off-by: Baorong Liu <baorliu@cisco.com>

linux-foundation-easycla · 2026-06-15T19:33:03Z

The committers listed above are authorized under a signed CLA.

✅ login: baorliu / name: Baorong Liu (87c6166, 9152e81, c9c67ac, fa9d78d, 7eac609, cb9bca0)
✅ login: sridhartalari / name: Sridhar talari (041ce33, aac7e7e, be5068b)

mssonicbld · 2026-06-15T19:33:04Z

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azure-pipelines · 2026-06-15T20:02:58Z

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prsunny · 2026-06-16T20:29:14Z

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prsunny · 2026-06-16T20:29:22Z

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Merge PR sonic-net#4253 and address review feedback: fix GCC 14 pclose deleter build failure, validate STATE_DB numeric fields, correct BFDDP header byte order, link-local detection, resource cleanup, and master merge conflicts in mock_tests Makefile. Use ephemeral port 0 in unit tests to avoid CI bind conflicts on the default BFDDP port. Signed-off-by: Sridhar talari <stalarir@cisco.com>

mssonicbld · 2026-06-17T18:59:24Z

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azure-pipelines · 2026-06-17T18:59:35Z

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mssonicbld · 2026-06-25T18:59:25Z

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Link mock_redisreply.cpp so RedisReply::checkReplyType is stubbed in the mock Redis environment, and reset the mock DB in SetUp like other mock test suites. Signed-off-by: Sridhar talari <stalarir@cisco.com>

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mssonicbld · 2026-06-25T18:59:59Z

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sridhartalari · 2026-06-25T19:01:05Z

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azure-pipelines · 2026-06-25T19:01:12Z

Commenter does not have sufficient privileges for PR 4676 in repo sonic-net/sonic-swss

mssonicbld · 2026-06-29T23:26:53Z

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mssonicbld · 2026-06-29T23:28:00Z

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azure-pipelines · 2026-06-29T23:28:10Z

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Extend bfdsyncd mock tests for IPv4 sessions, duplicate handling, state updates, and invalid messages; add pytest cases for src_mac and unknown BFD session state notifications in bfdorch. Signed-off-by: Sridhar talari <stalarir@cisco.com>

mssonicbld · 2026-06-30T16:46:22Z

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addDefaultIpv6Session() referenced MockBfdLink before the class was declared, breaking the amd64 build. Signed-off-by: Sridhar talari <stalarir@cisco.com>

mssonicbld · 2026-06-30T17:23:17Z

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handleBfdStateUpdate returns sendmsg()'s bool result; without WillOnce(Return(true)) the gmock default false fails ASSERT_TRUE. Signed-off-by: Sridhar talari <stalarir@cisco.com>

mssonicbld · 2026-06-30T18:15:45Z

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azure-pipelines · 2026-06-30T18:15:56Z

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Copilot

Pull request overview

Adds the new bfdsyncd daemon to integrate FRR bfdd (BFDDP) with SONiC’s hardware-offloaded BFD sessions managed by BfdOrch, and extends BFD session handling/tests to cover additional state and MAC address behaviors.

Changes:

Introduces bfdsyncd (new subdir, build integration, BFDDP protocol header, link implementation, daemon main loop).
Enhances BfdOrch to publish remote-session parameters on state changes and to honor an optional src_mac when creating hardware-lookup-invalid BFD sessions.
Adds/extends unit and VS tests for bfdsyncd, src_mac, and unknown session notifications.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
Makefile.am	Adds `bfdsyncd` to build subdirectories.
configure.ac	Adds `bfdsyncd/Makefile` to autoconf outputs.
orchagent/bfdorch.cpp	Updates state-change handling and supports optional `src_mac` in BFD session creation.
bfdsyncd/Makefile.am	Defines build rules for the new `bfdsyncd` binary.
bfdsyncd/bfdsyncd.cpp	Implements the `bfdsyncd` daemon main loop and CLI parsing.
bfdsyncd/bfdlink.h	Declares the BFDDP link class used by the daemon/tests.
bfdsyncd/bfdlink.cpp	Implements BFDDP message handling, APP_DB session programming, and STATE_DB-driven state updates back to `bfdd`.
bfdsyncd/bfdd/bfddp_packet.h	Adds BFDDP wire structures/enums used by `bfdsyncd`.
tests/mock_tests/Makefile.am	Adds `tests_bfdsyncd` to mock-test build and runner lists.
tests/mock_tests/bfdsyncd/test_bfdlink.cpp	Adds unit tests for BFDDP parsing/state updates and IPv4 link-local rejection.
tests/test_bfd.py	Adds VS tests for `src_mac` handling and unknown-session notifications.

+#include <iostream>
+#include <inttypes.h>


+    ifindex = ntohl(bm.data.session.ifindex);
+    memcpy(&ifname, bm.data.session.ifname, IFNAME_LEN);


+    size_t pos = s.find("|");
+    std::string vrf = s.substr(0, pos);
+    s.erase(0, pos+1);
+    pos = s.find("|");
+    std::string intf = s.substr(0, pos);
+    s.erase(0, pos+1);
+    std::string ip = s;


Fix bfdorch state update to avoid duplicate STATE_DB fields, harden bfdsyncd/bfdlink key parsing and invalid-message handling, validate port and remote_multiplier inputs, and add unit/VS tests for malformed keys, overflow values, unsupported message types, and IPv4 paths. Signed-off-by: Sridhar talari <stalarir@cisco.com>

mssonicbld · 2026-06-30T23:35:54Z

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mssonicbld · 2026-08-05T18:04:26Z

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azure-pipelines · 2026-08-05T18:04:38Z

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…sage Remove link-local address detection, interface-based key construction, MAC address resolution (ping/ARP/NDP), and dst_mac/src_mac fields from APP_DB entries. HW offload now handles multihop sessions only. Signed-off-by: stalarir <stalarir@cisco.com>

mssonicbld · 2026-08-06T21:48:14Z

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Signed-off-by: stalarir <stalarir@cisco.com>

mssonicbld · 2026-08-07T00:20:47Z

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Signed-off-by: stalarir <stalarir@cisco.com>

mssonicbld · 2026-08-07T03:18:24Z

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azure-pipelines · 2026-08-07T03:18:35Z

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baorliu and others added 6 commits February 23, 2026 14:34

bfdsyncd, recover pr 3267

87c6166

Signed-off-by: Baorong Liu <96146196+baorliu@users.noreply.github.com>

fix tests

fa9d78d

Signed-off-by: Baorong Liu <96146196+baorliu@users.noreply.github.com>

fix tests

9152e81

Signed-off-by: Baorong Liu <96146196+baorliu@users.noreply.github.com>

fix tests

c9c67ac

Signed-off-by: Baorong Liu <96146196+baorliu@users.noreply.github.com>

resolve conflicts in mock_test Makefile.am

cb9bca0

Signed-off-by: Baorong Liu <baorliu@cisco.com>

Merge branch 'master' into baorliu_bgp_bfd_new

7eac609

Signed-off-by: Baorong Liu <baorliu@cisco.com>

sridhartalari requested a review from prsunny as a code owner June 15, 2026 19:32

sridhartalari force-pushed the bfd-hw-offload-patched branch from 5cbf1e8 to 041ce33 Compare June 17, 2026 18:59

Fix tests_bfdsyncd fixture failure on ProducerStateTable SCRIPT LOAD

be5068b

Link mock_redisreply.cpp so RedisReply::checkReplyType is stubbed in the mock Redis environment, and reset the mock DB in SetUp like other mock test suites. Signed-off-by: Sridhar talari <stalarir@cisco.com>

sridhartalari force-pushed the bfd-hw-offload-patched branch from 964c013 to be5068b Compare June 25, 2026 18:59

sridhartalari force-pushed the bfd-hw-offload-patched branch from fd7dc81 to e914be2 Compare June 29, 2026 23:27

Add bfd unit tests to improve PR diff coverage.

3b6b342

Extend bfdsyncd mock tests for IPv4 sessions, duplicate handling, state updates, and invalid messages; add pytest cases for src_mac and unknown BFD session state notifications in bfdorch. Signed-off-by: Sridhar talari <stalarir@cisco.com>

Fix tests_bfdsyncd compile: define helper after MockBfdLink.

bf39134

addDefaultIpv6Session() referenced MockBfdLink before the class was declared, breaking the amd64 build. Signed-off-by: Sridhar talari <stalarir@cisco.com>

Fix StateUpdateWithRemoteFields mock sendmsg return value.

3dc808d

handleBfdStateUpdate returns sendmsg()'s bool result; without WillOnce(Return(true)) the gmock default false fails ASSERT_TRUE. Signed-off-by: Sridhar talari <stalarir@cisco.com>

prsunny mentioned this pull request Jun 30, 2026

BFD hardware offload for BGP sessions #4253

Closed

prsunny requested review from abdosi, Copilot and zjswhhh June 30, 2026 22:50

Copilot started reviewing on behalf of prsunny June 30, 2026 22:50 View session

Copilot AI reviewed Jun 30, 2026

View reviewed changes

Merge branch 'master' into bfd-hw-offload-patched

519052d

[bfdsyncd]: address PR 4676 follow-ups and drop link-local tests

3964ac5

Signed-off-by: stalarir <stalarir@cisco.com>

Fix bfdsyncd unused IPv4 variable build failure

726242e

Signed-off-by: stalarir <stalarir@cisco.com>

		ifindex = ntohl(bm.data.session.ifindex);
		memcpy(&ifname, bm.data.session.ifname, IFNAME_LEN);

		#include <iostream>
		#include <inttypes.h>

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