add: separate mod for xdp

Signed-off-by: yogaraj.s <[email protected]>

libbpf-rs/src/lib.rs

@@ -93,6 +93,7 @@ mod ringbuf;
 mod skeleton;
 mod tc;
 mod util;
+mod xdp;
 
 pub use libbpf_sys;
 
@@ -142,6 +143,8 @@ pub use crate::tc::TC_H_MIN_EGRESS;
 pub use crate::tc::TC_H_MIN_INGRESS;
 pub use crate::tc::TC_INGRESS;
 pub use crate::util::num_possible_cpus;
+pub use crate::xdp::Xdp;
+pub use crate::xdp::XdpFlags;
 
 /// Used for skeleton -- an end user may not consider this API stable
 #[doc(hidden)]

libbpf-rs/src/xdp.rs

@@ -0,0 +1,96 @@
+use bitflags::bitflags;
+use std::mem::size_of;
+use std::os::unix::io::AsRawFd;
+use std::os::unix::io::BorrowedFd;
+
+use crate::util;
+use crate::Error;
+use crate::Result;
+
+bitflags! {
+    /// Flags to configure the `XDP` operations
+    pub struct XdpFlags: u32 {
+        /// See [`libbpf_sys::XDP_FLAGS_UPDATE_IF_NOEXIST`].
+        const UPDATE_IF_NOEXIST = libbpf_sys::XDP_FLAGS_UPDATE_IF_NOEXIST as _;
+        /// See [`libbpf_sys::XDP_FLAGS_SKB_MODE`].
+        const SKB_MODE          = libbpf_sys::XDP_FLAGS_SKB_MODE as _;
+        /// See [`libbpf_sys::XDP_FLAGS_DRV_MODE`].
+        const DRV_MODE          = libbpf_sys::XDP_FLAGS_DRV_MODE as _;
+        /// See [`libbpf_sys::XDP_FLAGS_HW_MODE`].
+        const HW_MODE           = libbpf_sys::XDP_FLAGS_HW_MODE as _;
+        /// See [`libbpf_sys::XDP_FLAGS_REPLACE`].
+        const REPLACE           = libbpf_sys::XDP_FLAGS_REPLACE as _;
+        /// See [`libbpf_sys::XDP_FLAGS_MODES`].
+        const MODES             = libbpf_sys::XDP_FLAGS_MODES as _;
+        /// See [`libbpf_sys::XDP_FLAGS_MASK`].
+        const MASK              = libbpf_sys::XDP_FLAGS_MASK as _;
+    }
+
+}
+
+/// Represents a XDP program.
+///
+/// This struct exposes operations to attach, detach and query a XDP program
+#[derive(Debug)]
+pub struct Xdp<'fd> {
+    fd: BorrowedFd<'fd>,
+    attach_opts: libbpf_sys::bpf_xdp_attach_opts,
+    query_opts: libbpf_sys::bpf_xdp_query_opts,
+}
+
+impl<'fd> Xdp<'fd> {
+    /// Create a new xdp instance with the given file descriptor of the `SEC("xdp")` [`Program`][crate::Program].
+    pub fn new(fd: BorrowedFd<'fd>) -> Self {
+        let mut xdp = Xdp {
+            fd,
+            attach_opts: libbpf_sys::bpf_xdp_attach_opts::default(),
+            query_opts: libbpf_sys::bpf_xdp_query_opts::default(),
+        };
+        xdp.attach_opts.sz = size_of::<libbpf_sys::bpf_xdp_attach_opts>() as libbpf_sys::size_t;
+        xdp.query_opts.sz = size_of::<libbpf_sys::bpf_xdp_query_opts>() as libbpf_sys::size_t;
+        xdp
+    }
+
+    /// Attach the XDP program to the given interface to start processing the packets
+    pub fn attach(&self, ifindex: i32, flags: XdpFlags) -> Result<()> {
+        let ret = unsafe {
+            libbpf_sys::bpf_xdp_attach(
+                ifindex,
+                self.fd.as_raw_fd(),
+                flags.bits(),
+                &self.attach_opts,
+            )
+        };
+        util::parse_ret(ret)
+    }
+
+    /// Detach the XDP program from the interface
+    pub fn detach(&self, ifindex: i32, flags: XdpFlags) -> Result<()> {
+        let ret = unsafe { libbpf_sys::bpf_xdp_detach(ifindex, flags.bits(), &self.attach_opts) };
+        util::parse_ret(ret)
+    }
+
+    /// Query to inspect the program
+    pub fn query(&self, ifindex: i32, flags: XdpFlags) -> Result<libbpf_sys::bpf_xdp_query_opts> {
+        let mut opts = self.query_opts;
+        let err = unsafe { libbpf_sys::bpf_xdp_query(ifindex, flags.bits() as i32, &mut opts) };
+        if err != 0 {
+            Err(Error::from_raw_os_error(err))
+        } else {
+            Ok(opts)
+        }
+    }
+
+    /// Query to inspect the program identifier (prog_id)
+    pub fn query_id(&self, ifindex: i32, flags: XdpFlags) -> Result<u32> {
+        let mut prog_id: u32 = 0;
+        let err = unsafe {
+            libbpf_sys::bpf_xdp_query_id(ifindex, flags.bits() as i32, (&mut prog_id) as *mut u32)
+        };
+        if err != 0 {
+            Err(Error::from_raw_os_error(err))
+        } else {
+            Ok(prog_id)
+        }
+    }
+}

libbpf-rs/tests/bin/src/xdp.bpf.c

@@ -0,0 +1,7 @@
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+
+SEC("xdp")
+int xdp_filter(struct xdp_md *ctx) {
+    return XDP_PASS;
+}

libbpf-rs/tests/test_xdp.rs

@@ -0,0 +1,40 @@
+mod test;
+use std::os::fd::AsFd;
+use test::bump_rlimit_mlock;
+use test::get_test_object;
+
+use libbpf_rs::Xdp;
+use libbpf_rs::XdpFlags;
+
+const LO_IFINDEX: i32 = 1;
+
+#[test]
+fn test_sudo_xdp() {
+    bump_rlimit_mlock();
+
+    let obj = get_test_object("xdp.bpf.o");
+    let fd = obj.prog("xdp_filter").unwrap().as_fd();
+
+    let xdp_prog = Xdp::new(fd);
+
+    assert!(xdp_prog
+        .attach(LO_IFINDEX, XdpFlags::UPDATE_IF_NOEXIST)
+        .is_ok());
+
+    // Second attach should fail as a prog is already loaded
+    assert!(xdp_prog
+        .attach(LO_IFINDEX, XdpFlags::UPDATE_IF_NOEXIST)
+        .is_err());
+
+    assert!(xdp_prog
+        .query_id(LO_IFINDEX, XdpFlags::UPDATE_IF_NOEXIST)
+        .is_ok());
+
+    assert!(xdp_prog
+        .query(LO_IFINDEX, XdpFlags::UPDATE_IF_NOEXIST)
+        .is_ok());
+
+    assert!(xdp_prog
+        .detach(LO_IFINDEX, XdpFlags::UPDATE_IF_NOEXIST)
+        .is_ok());
+}