Add support for parsing some FreeBSD specific attributes by bigsaltyfishes · Pull Request #221 · rust-netlink/netlink-packet-route

bigsaltyfishes · 2026-01-05T10:56:38Z

IFA_FREEBSD (Conficts with IFA_PROTO in FreeBSD)
RTA_RTFLAGS, RTA_KNH_ID and RTA_WEIGHT
IFLA_FREEBSD
NDA_FREEBSD
STATS64 (Structure is different)
FreeBSD's LinkLayerType
Unit tests for FreeBSD (Due to difference of structure, most of current unit tests won't build, need to disable them on FreeBSD)
Add more link InfoKind.

gemini-code-assist · 2026-01-05T10:57:00Z

Summary of Changes

Hello @bigsaltyfishes, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly enhances the netlink-packet-route crate by integrating support for several FreeBSD-specific Netlink attributes. It introduces new modules and data types tailored for FreeBSD's network configuration, allowing the library to accurately interpret and construct platform-specific address and route messages. The changes are carefully isolated using conditional compilation to maintain cross-platform compatibility.

Highlights

FreeBSD Address Attributes: Introduced support for the IFA_FREEBSD attribute in address messages, which is conditionally compiled for FreeBSD targets. This includes new IfaFlags for IPv6 interface flags, defining specific states like Anycast, Tentative, and Deprecated.
FreeBSD Route Attributes: Added parsing and emission support for FreeBSD-specific route attributes: RTA_RTFLAGS, RTA_KNH_ID (kernel nexthop ID), and RTA_WEIGHT (path weight). This also includes a new RtFlags bitflag structure to represent various FreeBSD route flags.
Platform-Specific Implementation: All new attributes and their associated data structures are implemented using Rust's #[cfg(target_os = "freebsd")] attribute, ensuring that these FreeBSD-specific features are only included when compiling for the FreeBSD operating system.

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Code Review

This pull request adds support for parsing FreeBSD-specific netlink attributes for network addresses and routes. The changes are well-structured, using conditional compilation to isolate the FreeBSD-specific logic. I've identified one critical issue that would break compilation on non-FreeBSD platforms, and a few medium-severity issues related to code style and potential compiler warnings. Addressing these points will improve the robustness and clarity of the code.

codecov · 2026-01-06T13:41:42Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.92%. Comparing base (1fb4bd7) to head (a6f5446).
⚠️ Report is 6 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #221      +/-   ##
==========================================
- Coverage   68.10%   67.92%   -0.18%     
==========================================
  Files         144      140       -4     
  Lines       10103     9959     -144     
==========================================
- Hits         6881     6765     -116     
+ Misses       3222     3194      -28

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cathay4t

Rename the FreeBSD to more specific name.
The Nla::kind is wrong.
Do not use magic number. Hard to maintain and verify in BSD kernel code.
Unit test is mandatory. Google says tcpdump -i lo0 -n 'netlink' can capture netlink message in FreeBSD. Without emit and parse test, I cannot tell whether you are doing correct or not.
Please include short commit message indicate which FreeBSD kernel file is handling these attribute so developer could review.

cathay4t · 2026-01-06T13:42:24Z

+
+#[non_exhaustive]
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
+pub enum FreeBSD {


How about FreeBsdAddressAttribute to be more specific?

cathay4t · 2026-01-06T13:42:58Z

+        let value = parse_u32(buf.value())
+            .context("failed to parse IFA_FREEBSD attribute value")?;
+        match buf.value_type() {
+            1 => Ok(FreeBSD::Vhid(value)),


Please change magic number to constant.

cathay4t · 2026-01-06T13:44:24Z

+
+impl Nla for FreeBSD {
+    fn kind(&self) -> u16 {
+        11


The kind here is wrong.

It should be kind of VhId, IfaFlags and etc.

cathay4t · 2026-01-06T13:45:16Z

+#[non_exhaustive]
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
+pub enum FreeBSD {
+    Unspecified,


Remove this unless freebsd code is using this unspec in real environment instead of place holder.

cathay4t · 2026-01-06T13:47:37Z

+#[non_exhaustive]
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
+pub enum FreeBSD {
+    Unspecified,


Remove unspec if it is a place holder.

cathay4t · 2026-01-06T13:47:58Z

+        cap_bit_size: u32,
+        supported_caps: (IfCapFlags, IfCap2Flags),
+        active_caps: (IfCapFlags, IfCap2Flags),
+    },


Add Other(DefaultNla) for future FreeBSD kernel.

cathay4t · 2026-01-06T13:48:06Z

+    IfCaps {
+        cap_bit_size: u32,
+        supported_caps: (IfCapFlags, IfCap2Flags),
+        active_caps: (IfCapFlags, IfCap2Flags),


Create a struct for this.

cathay4t · 2026-01-06T13:48:46Z

+        }
+
+        match buf.value_type() {
+            2 => {


Use constant instead of magic number.

cathay4t · 2026-01-06T13:49:08Z

+
+impl Nla for FreeBSD {
+    fn kind(&self) -> u16 {
+        64


It should be kind of FreeBSD::IfCaps and etc.

bigsaltyfishes · 2026-01-07T12:21:37Z

I have modified and added unit tests. Because some constant and structure definitions in FreeBSD differ significantly from those in Linux, I have added the missing constants and different structures.

cathay4t · 2026-02-02T02:28:31Z

@bigsaltyfishes Could you include an example code into /examples folder for me to run in FreeBSD env? That could explains the purpose of this PR and easy for me to try out.

cathay4t · 2026-03-02T07:11:17Z

@bigsaltyfishes any comments?

bigsaltyfishes · 2026-03-02T08:44:24Z

Added Examples and rebased, need to be tested on Linux.

bigsaltyfishes · 2026-03-02T09:05:20Z

@cathay4t Examples added, since rust's libc does not support netlink on FreeBSD, I added a ffi for examples.

cathay4t · 2026-03-31T11:29:20Z

Great. Let me install a FreeBSD and try it out.

cathay4t · 2026-03-31T13:53:31Z

@bigsaltyfishes I got failure when running this command in FreeBSD 15:

cargo run --example  dump_packet_links

Error is:

    ::: examples/freebsd/mod.rs:13:1
     |
  13 | pub struct NetlinkSocket(OwnedFd);
     | ------------------------ method `write_all` not found for this struct
    --> examples/dump_packet_links.rs:105:12
     |
 105 |     socket.write_all(&buf[..]).unwrap();
     |            ^^^^^^^^^
     |
     = help: items from traits can only be used if the trait is in scope
help: trait `Write` which provides `write_all` is implemented but not in scope; perhaps you want to import it
     |
   3 + use std::io::Write;
     |
help: there is a method `write` with a similar name
     |
 105 -     socket.write_all(&buf[..]).unwrap();
 105 +     socket.write(&buf[..]).unwrap();
     |

error[E0599]: no method named `read` found for struct `NetlinkSocket` in the current scope
   --> examples/dump_packet_links.rs:113:27
    |
113 |         let size = socket.read(&mut &mut receive_buffer[..]).unwrap();
    |                           ^^^^ method not found in `NetlinkSocket`
    |
   ::: /usr/local/lib/rustlib/src/rust/library/std/src/io/mod.rs:813:8
    |
813 |     fn read(&mut self, buf: &mut [u8]) -> Result<usize>;
    |        ---- the method is available for `NetlinkSocket` here
    |
   ::: examples/freebsd/mod.rs:13:1
    |
 13 | pub struct NetlinkSocket(OwnedFd);
    | ------------------------ method `read` not found for this struct
    |
    = help: items from traits can only be used if the trait is in scope
help: trait `Read` which provides `read` is implemented but not in scope; perhaps you want to import it
    |
  3 + use std::io::Read;

Due to the difference of contant and support features, some tests may failed. Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

- flags from: https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/net/if.h#L139-L173 - layer type from: https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/net/if_types.h#L44-L258 (ARPHRD_NETROM is not defined in kernel, but as metioned in https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/tests/sys/netlink/test_rtnl_iface.py#L307-L354, just defined it in layer type like Linux.) - info kinds comes from drivers, attach to list via `ifc_attach_cloner`, for wireless device is "wlan", and for loopback is "lo". (Related: https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/net80211/ieee80211_freebsd.c#L1397, https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/net/if_loop.c#L150, https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/iface.c#L364) Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

- `IFA_FREEBSD` and its nested value type are defined at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/ifaddrs.h#L63-L73, handled at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/iface.c#L1007-L1023 - `IfaFlags` from: https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netinet6/in6_var.h#L490-L503 Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

They are FreeBSD specific flags - All of them are defined at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/route.h#L145-L181, handled at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/rt.c#L220-L260 - `RtFlags` from: https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/net/route.h#L166-L197 Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

As defined at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/interface.h#L209-L235, there are no `rx_otherhost_dropped` filed in `Stats64`. Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

- `IFLA_FREEBSD` and its nested value types are defined at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/interface.h#L145-L156, handled at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/iface.c#L350-L357 Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

- `NDA_FREEBSD` and its nested value type are defined at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/neigh.h#L66-L75, handled at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/neigh.c#L193-L198 Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

Add missing kinds and disable Linux-specific ones for FreeBSD. Currently, only Vlan kind supports `IFLA_INFO_DATA`. Reference: https://github.com/freebsd/freebsd-src/blob/main/sys/net/if_vlan.c#L1213-L1296 Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

* Unsupported methods: https://github.com/freebsd/freebsd-src/blob/release/15.0.0/sys/netlink/route/common.h#L50-L86 Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

Signed-off-by: bigsaltyfishes <bigsaltyfishes@gmail.com>

…FI example Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

…tests - Some test data is not supported on FreeBSD, since the tests consistently fail on this platform, just disable them for FreeBSD. Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

bigsaltyfishes · 2026-04-02T13:50:16Z

@cathay4t Okay, my fault during testing on Linux. I've revert changes. Should work now.

gemini-code-assist Bot reviewed Jan 5, 2026

View reviewed changes

Comment thread src/address/attribute.rs

Comment thread src/address/freebsd.rs

Comment thread src/route/attribute.rs

Comment thread src/route/attribute.rs

Comment thread src/route/attribute.rs

bigsaltyfishes force-pushed the main branch 6 times, most recently from a1ddf7d to a6f5446 Compare January 6, 2026 11:35

bigsaltyfishes changed the title ~~DRAFT: Add support for parsing FreeBSD specific attributes~~ Add support for parsing some FreeBSD specific attributes Jan 6, 2026

bigsaltyfishes marked this pull request as ready for review January 6, 2026 11:38

cathay4t requested changes Jan 6, 2026

View reviewed changes

bigsaltyfishes force-pushed the main branch 4 times, most recently from 6066615 to 7119fa5 Compare January 7, 2026 11:24

bigsaltyfishes requested a review from cathay4t January 7, 2026 12:22

bigsaltyfishes force-pushed the main branch 3 times, most recently from b71a221 to 26328c8 Compare January 8, 2026 12:08

bigsaltyfishes force-pushed the main branch from 26328c8 to bd7524c Compare February 1, 2026 16:16

bigsaltyfishes force-pushed the main branch from bd7524c to 922189d Compare March 2, 2026 08:43

bigsaltyfishes force-pushed the main branch from ec551c4 to 685908b Compare April 2, 2026 13:05

bigsaltyfishes added 10 commits April 2, 2026 21:06

treewide: Make tests build on FreeBSD

52a4f2a

Due to the difference of contant and support features, some tests may failed. Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

link: Add support for emit Stat64 on FreeBSD

d00242c

As defined at https://github.com/freebsd/freebsd-src/blob/release/15.0.0-p1/sys/netlink/route/interface.h#L209-L235, there are no `rx_otherhost_dropped` filed in `Stats64`. Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

examples: Add FreeBSD examples and disables unsupported one.

68a077f

* Unsupported methods: https://github.com/freebsd/freebsd-src/blob/release/15.0.0/sys/netlink/route/common.h#L50-L86 Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

fix: Fix build and test on Linux

837d641

Signed-off-by: bigsaltyfishes <bigsaltyfishes@gmail.com>

bigsaltyfishes force-pushed the main branch from 685908b to da9127f Compare April 2, 2026 13:12

bigsaltyfishes added 4 commits April 2, 2026 21:20

fix(tests): MSRV fix for FreeBSD

269cdb6

Signed-off-by: bigsaltyfishes <bigsaltyfishes@gmail.com>

fix: Allow dead code and non-standard naming conventions in FreeBSD F…

468fac3

…FI example Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

fix(examples): Move std::io import to FreeBSD main function

4c0f405

Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

fix: reformat code

5432a1c

Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

bigsaltyfishes force-pushed the main branch from ae702b3 to 5432a1c Compare April 2, 2026 13:20

bigsaltyfishes added 2 commits April 2, 2026 21:47

fix: Add conditional compilation for FreeBSD in various examples and …

7f4c5ac

…tests - Some test data is not supported on FreeBSD, since the tests consistently fail on this platform, just disable them for FreeBSD. Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

fix: fix clippy on FreeBSD

4a20e21

Signed-off-by: molyuu <bigsaltyfishes@gmail.com>

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