aya: Implement forget_link

Fixes #51

Signed-off-by: Dave Tucker <dave@dtucker.co.uk>

aya/src/programs/cgroup_skb.rs

@@ -9,7 +9,8 @@ use crate::{
         bpf_prog_type::BPF_PROG_TYPE_CGROUP_SKB,
     },
     programs::{
-        define_link_wrapper, load_program, FdLink, Link, ProgAttachLink, ProgramData, ProgramError,
+        define_link_wrapper, load_program, FdLink, Link, OwnedLink, ProgAttachLink, ProgramData,
+        ProgramError,
     },
     sys::{bpf_link_create, bpf_prog_attach, kernel_version},
 };
@@ -116,6 +117,17 @@ impl CgroupSkb {
         }
     }
 
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: CgroupSkbLinkId,
+    ) -> Result<OwnedLink<CgroupSkbLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
+
     /// Detaches the program.
     ///
     /// See [CgroupSkb::attach].
@@ -155,6 +167,7 @@ impl Link for CgroupSkbLinkInner {
 }
 
 define_link_wrapper!(
+    /// The link used by [CgroupSkb] programs.
     CgroupSkbLink,
     /// The type returned by [CgroupSkb::attach]. Can be passed to [CgroupSkb::detach].
     CgroupSkbLinkId,

aya/src/programs/extension.rs

@@ -6,7 +6,9 @@ use object::Endianness;
 use crate::{
     generated::{bpf_attach_type::BPF_CGROUP_INET_INGRESS, bpf_prog_type::BPF_PROG_TYPE_EXT},
     obj::btf::BtfKind,
-    programs::{define_link_wrapper, load_program, FdLink, FdLinkId, ProgramData, ProgramError},
+    programs::{
+        define_link_wrapper, load_program, FdLink, FdLinkId, OwnedLink, ProgramData, ProgramError,
+    },
     sys::{self, bpf_link_create},
     Btf,
 };
@@ -146,9 +148,21 @@ impl Extension {
     pub fn detach(&mut self, link_id: ExtensionLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: ExtensionLinkId,
+    ) -> Result<OwnedLink<ExtensionLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [Extension] programs.
     ExtensionLink,
     /// The type returned by [Extension::attach]. Can be passed to [Extension::detach].
     ExtensionLinkId,

aya/src/programs/fentry.rs

@@ -5,7 +5,7 @@ use crate::{
     obj::btf::{Btf, BtfKind},
     programs::{
         define_link_wrapper, load_program, utils::attach_raw_tracepoint, FdLink, FdLinkId,
-        ProgramData, ProgramError,
+        OwnedLink, ProgramData, ProgramError,
     },
 };
 
@@ -75,9 +75,21 @@ impl FEntry {
     pub fn detach(&mut self, link_id: FEntryLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: FEntryLinkId,
+    ) -> Result<OwnedLink<FEntryLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [FEntry] programs.
     FEntryLink,
     /// The type returned by [FEntry::attach]. Can be passed to [FEntry::detach].
     FEntryLinkId,

aya/src/programs/fexit.rs

@@ -5,7 +5,7 @@ use crate::{
     obj::btf::{Btf, BtfKind},
     programs::{
         define_link_wrapper, load_program, utils::attach_raw_tracepoint, FdLink, FdLinkId,
-        ProgramData, ProgramError,
+        OwnedLink, ProgramData, ProgramError,
     },
 };
 
@@ -75,9 +75,21 @@ impl FExit {
     pub fn detach(&mut self, link_id: FExitLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: FExitLinkId,
+    ) -> Result<OwnedLink<FExitLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [FExit] programs.
     FExitLink,
     /// The type returned by [FExit::attach]. Can be passed to [FExit::detach].
     FExitLinkId,

aya/src/programs/kprobe.rs

@@ -8,7 +8,7 @@ use crate::{
         define_link_wrapper, load_program,
         perf_attach::{PerfLink, PerfLinkId},
         probe::{attach, ProbeKind},
-        ProgramData, ProgramError,
+        OwnedLink, ProgramData, ProgramError,
     },
 };
 
@@ -76,9 +76,21 @@ impl KProbe {
     pub fn detach(&mut self, link_id: KProbeLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: KProbeLinkId,
+    ) -> Result<OwnedLink<KProbeLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [KProbe] programs.
     KProbeLink,
     /// The type returned by [KProbe::attach]. Can be passed to [KProbe::detach].
     KProbeLinkId,

aya/src/programs/links.rs

@@ -1,19 +1,53 @@
 use libc::{close, dup};
+
 use std::{
+    borrow::Borrow,
     collections::{hash_map::Entry, HashMap},
+    ops::Deref,
     os::unix::prelude::RawFd,
 };
 
 use crate::{generated::bpf_attach_type, programs::ProgramError, sys::bpf_prog_detach};
 
-pub(crate) trait Link: std::fmt::Debug + 'static {
+/// A Link
+pub trait Link: std::fmt::Debug + 'static {
+    /// Unique Id
     type Id: std::fmt::Debug + std::hash::Hash + Eq + PartialEq;
 
+    /// Returns the link id
     fn id(&self) -> Self::Id;
 
+    /// Detaches the Link
     fn detach(self) -> Result<(), ProgramError>;
 }
 
+/// An owned link that automatically detaches the inner link when dropped.
+pub struct OwnedLink<T: Link> {
+    inner: Option<T>,
+}
+
+impl<T: Link> OwnedLink<T> {
+    pub(crate) fn new(inner: T) -> Self {
+        Self { inner: Some(inner) }
+    }
+}
+
+impl<T: Link> Deref for OwnedLink<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        self.inner.borrow().as_ref().unwrap()
+    }
+}
+
+impl<T: Link> Drop for OwnedLink<T> {
+    fn drop(&mut self) {
+        if let Some(link) = self.inner.take() {
+            link.detach().unwrap();
+        }
+    }
+}
+
 #[derive(Debug)]
 pub(crate) struct LinkMap<T: Link> {
     links: HashMap<T::Id, T>,
@@ -43,6 +77,10 @@ impl<T: Link> LinkMap<T> {
             .ok_or(ProgramError::NotAttached)?
             .detach()
     }
+
+    pub(crate) fn forget(&mut self, link_id: T::Id) -> Result<T, ProgramError> {
+        self.links.remove(&link_id).ok_or(ProgramError::NotAttached)
+    }
 }
 
 impl<T: Link> Drop for LinkMap<T> {
@@ -58,7 +96,7 @@ pub(crate) struct FdLinkId(pub(crate) RawFd);
 
 #[derive(Debug)]
 pub(crate) struct FdLink {
-    fd: RawFd,
+    pub(crate) fd: RawFd,
 }
 
 impl FdLink {
@@ -119,13 +157,14 @@ impl Link for ProgAttachLink {
 }
 
 macro_rules! define_link_wrapper {
-    ($wrapper:ident, #[$doc:meta] $wrapper_id:ident, $base:ident, $base_id:ident) => {
-        #[$doc]
+    (#[$doc1:meta] $wrapper:ident, #[$doc2:meta] $wrapper_id:ident, $base:ident, $base_id:ident) => {
+        #[$doc2]
         #[derive(Debug, Hash, Eq, PartialEq)]
         pub struct $wrapper_id($base_id);
 
+        #[$doc1]
         #[derive(Debug)]
-        pub(crate) struct $wrapper($base);
+        pub struct $wrapper($base);
 
         impl crate::programs::Link for $wrapper {
             type Id = $wrapper_id;
@@ -153,7 +192,7 @@ pub(crate) use define_link_wrapper;
 mod tests {
     use std::{cell::RefCell, rc::Rc};
 
-    use crate::programs::ProgramError;
+    use crate::programs::{OwnedLink, ProgramError};
 
     use super::{Link, LinkMap};
 
@@ -257,4 +296,58 @@ mod tests {
         assert!(*l1_detached.borrow() == 1);
         assert!(*l2_detached.borrow() == 1);
     }
+
+    #[test]
+    fn test_owned_detach() {
+        let l1 = TestLink::new(1, 2);
+        let l1_detached = Rc::clone(&l1.detached);
+        let l2 = TestLink::new(1, 3);
+        let l2_detached = Rc::clone(&l2.detached);
+
+        let owned_l1 = {
+            let mut links = LinkMap::new();
+            let id1 = links.insert(l1).unwrap();
+            links.insert(l2).unwrap();
+            // manually forget one link
+            let owned_l1 = links.forget(id1);
+            assert!(*l1_detached.borrow() == 0);
+            assert!(*l2_detached.borrow() == 0);
+            owned_l1.unwrap()
+        };
+
+        // l2 is detached on `Drop`, but l1 is still alive
+        assert!(*l1_detached.borrow() == 0);
+        assert!(*l2_detached.borrow() == 1);
+
+        // manually detach l1
+        assert!(owned_l1.detach().is_ok());
+        assert!(*l1_detached.borrow() == 1);
+        assert!(*l2_detached.borrow() == 1);
+    }
+
+    #[test]
+    fn test_owned_drop() {
+        let l1 = TestLink::new(1, 2);
+        let l1_detached = Rc::clone(&l1.detached);
+        let l2 = TestLink::new(1, 3);
+        let l2_detached = Rc::clone(&l2.detached);
+
+        {
+            let mut links = LinkMap::new();
+            let id1 = links.insert(l1).unwrap();
+            links.insert(l2).unwrap();
+
+            // manually forget one link and wrap in OwnedLink
+            let _ = OwnedLink {
+                inner: Some(links.forget(id1).unwrap()),
+            };
+
+            // OwnedLink was dropped in the statement above
+            assert!(*l1_detached.borrow() == 1);
+            assert!(*l2_detached.borrow() == 0);
+        };
+
+        assert!(*l1_detached.borrow() == 1);
+        assert!(*l2_detached.borrow() == 1);
+    }
 }

aya/src/programs/lirc_mode2.rs

@@ -2,7 +2,7 @@ use std::os::unix::prelude::{AsRawFd, RawFd};
 
 use crate::{
     generated::{bpf_attach_type::BPF_LIRC_MODE2, bpf_prog_type::BPF_PROG_TYPE_LIRC_MODE2},
-    programs::{load_program, query, Link, ProgramData, ProgramError, ProgramInfo},
+    programs::{load_program, query, Link, OwnedLink, ProgramData, ProgramError, ProgramInfo},
     sys::{bpf_obj_get_info_by_fd, bpf_prog_attach, bpf_prog_detach, bpf_prog_get_fd_by_id},
 };
 
@@ -81,6 +81,17 @@ impl LircMode2 {
         self.data.links.remove(link_id)
     }
 
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: LircLinkId,
+    ) -> Result<OwnedLink<LircLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
+
     /// Queries the lirc device for attached programs.
     pub fn query<T: AsRawFd>(target_fd: T) -> Result<Vec<LircLink>, ProgramError> {
         let prog_ids = query(target_fd.as_raw_fd(), BPF_LIRC_MODE2, 0, &mut None)?;
@@ -108,6 +119,7 @@ impl LircMode2 {
 pub struct LircLinkId(RawFd, RawFd);
 
 #[derive(Debug)]
+/// An LircMode2 Link
 pub struct LircLink {
     prog_fd: RawFd,
     target_fd: RawFd,
@@ -121,6 +133,7 @@ impl LircLink {
         }
     }
 
+    /// Get ProgramInfo from this link
     pub fn info(&self) -> Result<ProgramInfo, ProgramError> {
         match bpf_obj_get_info_by_fd(self.prog_fd) {
             Ok(info) => Ok(ProgramInfo(info)),

aya/src/programs/lsm.rs

@@ -4,7 +4,7 @@ use crate::{
     obj::btf::{Btf, BtfKind},
     programs::{
         define_link_wrapper, load_program, utils::attach_raw_tracepoint, FdLink, FdLinkId,
-        ProgramData, ProgramError,
+        OwnedLink, ProgramData, ProgramError,
     },
 };
 
@@ -80,9 +80,18 @@ impl Lsm {
     pub fn detach(&mut self, link_id: LsmLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(&mut self, link_id: LsmLinkId) -> Result<OwnedLink<LsmLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [Lsm] programs.
     LsmLink,
     /// The type returned by [Lsm::attach]. Can be passed to [Lsm::detach].
     LsmLinkId,

aya/src/programs/mod.rs

@@ -69,26 +69,27 @@ use std::{
 };
 use thiserror::Error;
 
-pub use cgroup_skb::{CgroupSkb, CgroupSkbAttachType, CgroupSkbLinkId};
-pub use extension::{Extension, ExtensionError, ExtensionLinkId};
-pub use fentry::{FEntry, FEntryLinkId};
-pub use fexit::{FExit, FExitLinkId};
-pub use kprobe::{KProbe, KProbeError, KProbeLinkId};
+pub use cgroup_skb::{CgroupSkb, CgroupSkbAttachType};
+pub use extension::{Extension, ExtensionError};
+pub use fentry::FEntry;
+pub use fexit::FExit;
+pub use kprobe::{KProbe, KProbeError};
 use links::*;
-pub use lirc_mode2::{LircLinkId, LircMode2};
-pub use lsm::{Lsm, LsmLinkId};
+pub use links::{Link, OwnedLink};
+pub use lirc_mode2::LircMode2;
+pub use lsm::Lsm;
 use perf_attach::*;
 pub use perf_event::{PerfEvent, PerfEventScope, PerfTypeId, SamplePolicy};
 pub use probe::ProbeKind;
-pub use raw_trace_point::{RawTracePoint, RawTracePointLinkId};
-pub use sk_msg::{SkMsg, SkMsgLinkId};
-pub use sk_skb::{SkSkb, SkSkbKind, SkSkbLinkId};
-pub use sock_ops::{SockOps, SockOpsLinkId};
-pub use socket_filter::{SocketFilter, SocketFilterError, SocketFilterLinkId};
-pub use tc::{SchedClassifier, SchedClassifierLinkId, TcAttachType, TcError};
-pub use tp_btf::{BtfTracePoint, BtfTracePointLinkId};
-pub use trace_point::{TracePoint, TracePointError, TracePointLinkId};
-pub use uprobe::{UProbe, UProbeError, UProbeLinkId};
+pub use raw_trace_point::RawTracePoint;
+pub use sk_msg::SkMsg;
+pub use sk_skb::{SkSkb, SkSkbKind};
+pub use sock_ops::SockOps;
+pub use socket_filter::{SocketFilter, SocketFilterError};
+pub use tc::{SchedClassifier, TcAttachType, TcError};
+pub use tp_btf::BtfTracePoint;
+pub use trace_point::{TracePoint, TracePointError};
+pub use uprobe::{UProbe, UProbeError};
 pub use xdp::{Xdp, XdpError, XdpFlags};
 
 use crate::{
@@ -355,6 +356,10 @@ impl<T: Link> ProgramData<T> {
         })?;
         Ok(())
     }
+
+    pub(crate) fn forget_link(&mut self, link_id: T::Id) -> Result<T, ProgramError> {
+        self.links.forget(link_id)
+    }
 }
 
 fn load_program<T: Link>(

aya/src/programs/perf_attach.rs

@@ -11,7 +11,7 @@ use crate::{
 pub struct PerfLinkId(RawFd);
 
 #[derive(Debug)]
-pub(crate) struct PerfLink {
+pub struct PerfLink {
     perf_fd: RawFd,
     probe_kind: Option<ProbeKind>,
     event_alias: Option<String>,

aya/src/programs/perf_event.rs

@@ -14,7 +14,7 @@ use crate::{
     programs::{
         load_program, perf_attach,
         perf_attach::{PerfLink, PerfLinkId},
-        ProgramData, ProgramError,
+        OwnedLink, ProgramData, ProgramError,
     },
     sys::perf_event_open,
 };
@@ -177,4 +177,15 @@ impl PerfEvent {
     pub fn detach(&mut self, link_id: PerfLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: PerfLinkId,
+    ) -> Result<OwnedLink<PerfLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }

aya/src/programs/raw_trace_point.rs

@@ -5,7 +5,7 @@ use crate::{
     generated::bpf_prog_type::BPF_PROG_TYPE_RAW_TRACEPOINT,
     programs::{
         define_link_wrapper, load_program, utils::attach_raw_tracepoint, FdLink, FdLinkId,
-        ProgramData, ProgramError,
+        OwnedLink, ProgramData, ProgramError,
     },
 };
 
@@ -59,9 +59,21 @@ impl RawTracePoint {
     pub fn detach(&mut self, link_id: RawTracePointLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: RawTracePointLinkId,
+    ) -> Result<OwnedLink<RawTracePointLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [RawTracePoint] programs.
     RawTracePointLink,
     /// The type returned by [RawTracePoint::attach]. Can be passed to [RawTracePoint::detach].
     RawTracePointLinkId,

aya/src/programs/sk_msg.rs

@@ -2,8 +2,8 @@ use crate::{
     generated::{bpf_attach_type::BPF_SK_MSG_VERDICT, bpf_prog_type::BPF_PROG_TYPE_SK_MSG},
     maps::sock::SocketMap,
     programs::{
-        define_link_wrapper, load_program, ProgAttachLink, ProgAttachLinkId, ProgramData,
-        ProgramError,
+        define_link_wrapper, load_program, OwnedLink, ProgAttachLink, ProgAttachLinkId,
+        ProgramData, ProgramError,
     },
     sys::bpf_prog_attach,
 };
@@ -94,9 +94,21 @@ impl SkMsg {
     pub fn detach(&mut self, link_id: SkMsgLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: SkMsgLinkId,
+    ) -> Result<OwnedLink<SkMsgLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [SkMsg] programs.
     SkMsgLink,
     /// The type returned by [SkMsg::attach]. Can be passed to [SkMsg::detach].
     SkMsgLinkId,

aya/src/programs/sk_skb.rs

@@ -5,8 +5,8 @@ use crate::{
     },
     maps::sock::SocketMap,
     programs::{
-        define_link_wrapper, load_program, ProgAttachLink, ProgAttachLinkId, ProgramData,
-        ProgramError,
+        define_link_wrapper, load_program, OwnedLink, ProgAttachLink, ProgAttachLinkId,
+        ProgramData, ProgramError,
     },
     sys::bpf_prog_attach,
 };
@@ -89,9 +89,21 @@ impl SkSkb {
     pub fn detach(&mut self, link_id: SkSkbLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: SkSkbLinkId,
+    ) -> Result<OwnedLink<SkSkbLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [SkSkb] programs.
     SkSkbLink,
     /// The type returned by [SkSkb::attach]. Can be passed to [SkSkb::detach].
     SkSkbLinkId,

aya/src/programs/sock_ops.rs

@@ -3,8 +3,8 @@ use std::os::unix::io::AsRawFd;
 use crate::{
     generated::{bpf_attach_type::BPF_CGROUP_SOCK_OPS, bpf_prog_type::BPF_PROG_TYPE_SOCK_OPS},
     programs::{
-        define_link_wrapper, load_program, ProgAttachLink, ProgAttachLinkId, ProgramData,
-        ProgramError,
+        define_link_wrapper, load_program, OwnedLink, ProgAttachLink, ProgAttachLinkId,
+        ProgramData, ProgramError,
     },
     sys::bpf_prog_attach,
 };
@@ -81,9 +81,21 @@ impl SockOps {
     pub fn detach(&mut self, link_id: SockOpsLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: SockOpsLinkId,
+    ) -> Result<OwnedLink<SockOpsLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [SockOps] programs.
     SockOpsLink,
     /// The type returned by [SockOps::attach]. Can be passed to [SockOps::detach].
     SockOpsLinkId,

aya/src/programs/socket_filter.rs

@@ -7,7 +7,7 @@ use thiserror::Error;
 
 use crate::{
     generated::{bpf_prog_type::BPF_PROG_TYPE_SOCKET_FILTER, SO_ATTACH_BPF, SO_DETACH_BPF},
-    programs::{load_program, Link, ProgramData, ProgramError},
+    programs::{load_program, Link, OwnedLink, ProgramData, ProgramError},
 };
 
 /// The type returned when attaching a [`SocketFilter`] fails.
@@ -101,14 +101,26 @@ impl SocketFilter {
     pub fn detach(&mut self, link_id: SocketFilterLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: SocketFilterLinkId,
+    ) -> Result<OwnedLink<SocketFilterLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 /// The type returned by [SocketFilter::attach]. Can be passed to [SocketFilter::detach].
 #[derive(Debug, Hash, Eq, PartialEq)]
 pub struct SocketFilterLinkId(RawFd, RawFd);
 
+/// A SocketFilter Link
 #[derive(Debug)]
-pub(crate) struct SocketFilterLink {
+pub struct SocketFilterLink {
     socket: RawFd,
     prog_fd: RawFd,
 }

aya/src/programs/tc.rs

@@ -10,7 +10,7 @@ use crate::{
     generated::{
         bpf_prog_type::BPF_PROG_TYPE_SCHED_CLS, TC_H_CLSACT, TC_H_MIN_EGRESS, TC_H_MIN_INGRESS,
     },
-    programs::{define_link_wrapper, load_program, Link, ProgramData, ProgramError},
+    programs::{define_link_wrapper, load_program, Link, OwnedLink, ProgramData, ProgramError},
     sys::{
         netlink_find_filter_with_name, netlink_qdisc_add_clsact, netlink_qdisc_attach,
         netlink_qdisc_detach,
@@ -141,6 +141,17 @@ impl SchedClassifier {
     pub fn detach(&mut self, link_id: SchedClassifierLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: SchedClassifierLinkId,
+    ) -> Result<OwnedLink<SchedClassifierLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 #[derive(Debug, Hash, Eq, PartialEq)]
@@ -168,6 +179,7 @@ impl Link for TcLink {
 }
 
 define_link_wrapper!(
+    /// The link used by [SchedClassifier] programs.
     SchedClassifierLink,
     /// The type returned by [SchedClassifier::attach]. Can be passed to [SchedClassifier::detach].
     SchedClassifierLinkId,

aya/src/programs/tp_btf.rs

@@ -4,7 +4,7 @@ use crate::{
     obj::btf::{Btf, BtfKind},
     programs::{
         define_link_wrapper, load_program, utils::attach_raw_tracepoint, FdLink, FdLinkId,
-        ProgramData, ProgramError,
+        OwnedLink, ProgramData, ProgramError,
     },
 };
 
@@ -78,9 +78,21 @@ impl BtfTracePoint {
     pub fn detach(&mut self, link_id: BtfTracePointLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: BtfTracePointLinkId,
+    ) -> Result<OwnedLink<BtfTracePointLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [BtfTracePoint] programs.
     BtfTracePointLink,
     /// The type returned by [BtfTracePoint::attach]. Can be passed to [BtfTracePoint::detach].
     BtfTracePointLinkId,

aya/src/programs/trace_point.rs

@@ -6,7 +6,7 @@ use crate::{
     programs::{
         define_link_wrapper, load_program,
         perf_attach::{perf_attach, PerfLink, PerfLinkId},
-        ProgramData, ProgramError,
+        OwnedLink, ProgramData, ProgramError,
     },
     sys::perf_event_open_trace_point,
 };
@@ -94,9 +94,21 @@ impl TracePoint {
     pub fn detach(&mut self, link_id: TracePointLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: TracePointLinkId,
+    ) -> Result<OwnedLink<TracePointLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [TracePoint] programs.
     TracePointLink,
     /// The type returned by [TracePoint::attach]. Can be passed to [TracePoint::detach].
     TracePointLinkId,

aya/src/programs/uprobe.rs

@@ -19,7 +19,7 @@ use crate::{
         define_link_wrapper, load_program,
         perf_attach::{PerfLink, PerfLinkId},
         probe::{attach, ProbeKind},
-        ProgramData, ProgramError,
+        OwnedLink, ProgramData, ProgramError,
     },
 };
 
@@ -128,9 +128,21 @@ impl UProbe {
     pub fn detach(&mut self, link_id: UProbeLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(
+        &mut self,
+        link_id: UProbeLinkId,
+    ) -> Result<OwnedLink<UProbeLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 define_link_wrapper!(
+    /// The link used by [UProbe] programs.
     UProbeLink,
     /// The type returned by [UProbe::attach]. Can be passed to [UProbe::detach].
     UProbeLinkId,

aya/src/programs/xdp.rs

@@ -10,7 +10,9 @@ use crate::{
         XDP_FLAGS_DRV_MODE, XDP_FLAGS_HW_MODE, XDP_FLAGS_REPLACE, XDP_FLAGS_SKB_MODE,
         XDP_FLAGS_UPDATE_IF_NOEXIST,
     },
-    programs::{define_link_wrapper, load_program, FdLink, Link, ProgramData, ProgramError},
+    programs::{
+        define_link_wrapper, load_program, FdLink, Link, OwnedLink, ProgramData, ProgramError,
+    },
     sys::{bpf_link_create, kernel_version, netlink_set_xdp_fd},
 };
 
@@ -130,6 +132,14 @@ impl Xdp {
     pub fn detach(&mut self, link_id: XdpLinkId) -> Result<(), ProgramError> {
         self.data.links.remove(link_id)
     }
+
+    /// Takes ownership of the link referenced by the provided link_id.
+    ///
+    /// The link will be detached on `Drop` and the caller is now responsible
+    /// for managing its lifetime.
+    pub fn forget_link(&mut self, link_id: XdpLinkId) -> Result<OwnedLink<XdpLink>, ProgramError> {
+        Ok(OwnedLink::new(self.data.forget_link(link_id)?))
+    }
 }
 
 #[derive(Debug)]
@@ -159,13 +169,13 @@ impl Link for NlLink {
 }
 
 #[derive(Debug, Hash, Eq, PartialEq)]
-enum XdpLinkIdInner {
+pub(crate) enum XdpLinkIdInner {
     FdLinkId(<FdLink as Link>::Id),
     NlLinkId(<NlLink as Link>::Id),
 }
 
 #[derive(Debug)]
-enum XdpLinkInner {
+pub(crate) enum XdpLinkInner {
     FdLink(FdLink),
     NlLink(NlLink),
 }
@@ -189,6 +199,7 @@ impl Link for XdpLinkInner {
 }
 
 define_link_wrapper!(
+    /// The link used by [Xdp] programs.
     XdpLink,
     /// The type returned by [Xdp::attach]. Can be passed to [Xdp::detach].
     XdpLinkId,