wrap OwnedFd of programs and maps around Arc

this allows ProgramFd, MapFd, and SockFd to not have lifetimes tied to
the programs/maps. This does mean these structs are no longer
Copy-able but that feels like a less of a breaking change

aya/src/maps/bloom_filter.rs

@@ -88,7 +88,7 @@ mod tests {
         sys::{override_syscall, SysResult, Syscall},
     };
     use libc::{EFAULT, ENOENT};
-    use std::{env, fs::File, io, os::fd::OwnedFd};
+    use std::{env, fs::File, io, os::fd::OwnedFd, sync::Arc};
 
     fn new_obj_map() -> obj::Map {
         obj::Map::Legacy(LegacyMap {
@@ -275,10 +275,12 @@ mod tests {
         ));
     }
 
-    fn create_fd() -> OwnedFd {
+    fn create_fd() -> Arc<OwnedFd> {
         let dir = env::temp_dir();
-        File::create(dir.join("f1"))
+        Arc::new(
-            .expect("unable to create file in tmpdir")
+            File::create(dir.join("f1"))
-            .into()
+                .expect("unable to create file in tmpdir")
+                .into(),
+        )
     }
 }

aya/src/maps/hash_map/hash_map.rs

@@ -105,7 +105,7 @@ impl<T: Borrow<MapData>, K: Pod, V: Pod> IterableMap<K, V> for HashMap<T, K, V>
 
 #[cfg(test)]
 mod tests {
-    use std::{env, fs::File, io, os::fd::OwnedFd};
+    use std::{env, fs::File, io, os::fd::OwnedFd, sync::Arc};
 
     use libc::{EFAULT, ENOENT};
 
@@ -696,10 +696,12 @@ mod tests {
         assert!(matches!(iter.next(), None));
     }
 
-    fn create_fd() -> OwnedFd {
+    fn create_fd() -> Arc<OwnedFd> {
         let dir = env::temp_dir();
-        File::create(dir.join("f1"))
+        Arc::new(
-            .expect("unable to create file in tmpdir")
+            File::create(dir.join("f1"))
-            .into()
+                .expect("unable to create file in tmpdir")
+                .into(),
+        )
     }
 }

aya/src/maps/lpm_trie.rs

@@ -207,7 +207,7 @@ mod tests {
         sys::{override_syscall, SysResult, Syscall},
     };
     use libc::{EFAULT, ENOENT};
-    use std::{env, fs::File, io, mem, net::Ipv4Addr, os::fd::OwnedFd};
+    use std::{env, fs::File, io, mem, net::Ipv4Addr, os::fd::OwnedFd, sync::Arc};
 
     fn new_obj_map() -> obj::Map {
         obj::Map::Legacy(LegacyMap {
@@ -456,10 +456,12 @@ mod tests {
         assert!(matches!(trie.get(&key, 0), Err(MapError::KeyNotFound)));
     }
 
-    fn create_fd() -> OwnedFd {
+    fn create_fd() -> Arc<OwnedFd> {
         let dir = env::temp_dir();
-        File::create(dir.join("f1"))
+        Arc::new(
-            .expect("unable to create file in tmpdir")
+            File::create(dir.join("f1"))
-            .into()
+                .expect("unable to create file in tmpdir")
+                .into(),
+        )
     }
 }

aya/src/maps/mod.rs

@@ -46,6 +46,7 @@ use std::{
     os::fd::{AsFd, AsRawFd, BorrowedFd, OwnedFd, RawFd},
     path::Path,
     ptr,
+    sync::Arc,
 };
 
 use libc::{getrlimit, rlimit, RLIMIT_MEMLOCK, RLIM_INFINITY};
@@ -186,15 +187,15 @@ pub enum MapError {
 }
 
 /// A map file descriptor.
-pub struct MapFd<'f>(BorrowedFd<'f>);
+pub struct MapFd(Arc<OwnedFd>);
 
-impl AsRawFd for MapFd<'_> {
+impl AsRawFd for MapFd {
     fn as_raw_fd(&self) -> RawFd {
         self.0.as_raw_fd()
     }
 }
 
-impl AsFd for MapFd<'_> {
+impl AsFd for MapFd {
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.0.as_fd()
     }
@@ -478,10 +479,10 @@ pub(crate) fn check_v_size<V>(map: &MapData) -> Result<(), MapError> {
 /// A generic handle to a BPF map.
 ///
 /// You should never need to use this unless you're implementing a new map type.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub struct MapData {
     pub(crate) obj: obj::Map,
-    pub(crate) fd: Option<OwnedFd>,
+    pub(crate) fd: Option<Arc<OwnedFd>>,
     pub(crate) btf_fd: Option<RawFd>,
     /// Indicates if this map has been pinned to bpffs
     pub pinned: bool,
@@ -509,7 +510,7 @@ impl MapData {
             }
         })?;
 
-        self.fd = Some(fd);
+        self.fd = Some(Arc::new(fd));
 
         Ok(())
     }
@@ -528,7 +529,7 @@ impl MapData {
             call: "BPF_OBJ_GET".to_string(),
             io_error,
         })?;
-        self.fd = Some(fd);
+        self.fd = Some(Arc::new(fd));
 
         Ok(())
     }
@@ -558,7 +559,7 @@ impl MapData {
 
         Ok(MapData {
             obj: parse_map_info(info, PinningType::ByName),
-            fd: Some(fd),
+            fd: Some(Arc::new(fd)),
             btf_fd: None,
             pinned: true,
         })
@@ -578,7 +579,7 @@ impl MapData {
 
         Ok(MapData {
             obj: parse_map_info(info, PinningType::None),
-            fd: Some(fd),
+            fd: Some(Arc::new(fd)),
             btf_fd: None,
             pinned: false,
         })
@@ -615,32 +616,9 @@ impl MapData {
     /// Returns the file descriptor of the map.
     ///
     /// Can be converted to [`RawFd`] using [`AsRawFd`].
-    pub fn fd(&self) -> Option<MapFd<'_>> {
+    pub fn fd(&self) -> Option<MapFd> {
-        self.fd.as_ref().map(|fd| MapFd(fd.as_fd()))
+        let fd = self.fd.clone()?;
-    }
+        Some(MapFd(fd))
-}
-
-impl MapData {
-    /// Attempts to duplicate MapData
-    ///
-    /// Fails if if the inner file descriptor could not be cloned
-    // TODO (AM): should we return MapError? New variant? Maybe make MapError non_exhaustive?
-    pub fn try_clone(&self) -> io::Result<Self> {
-        let fd = self.fd.as_ref().map(|f| f.try_clone()).transpose()?;
-
-        Ok(MapData {
-            fd,
-            obj: self.obj.clone(),
-            btf_fd: self.btf_fd,
-            pinned: self.pinned,
-        })
-    }
-}
-
-// TODO (AM): DELETE?
-impl Clone for MapData {
-    fn clone(&self) -> MapData {
-        self.try_clone().unwrap()
     }
 }
 

aya/src/maps/sock/mod.rs

@@ -5,22 +5,25 @@ mod sock_map;
 pub use sock_hash::SockHash;
 pub use sock_map::SockMap;
 
-use std::os::{
+use std::{
-    fd::{AsFd, BorrowedFd},
+    os::{
-    unix::io::{AsRawFd, RawFd},
+        fd::{AsFd, BorrowedFd, OwnedFd},
+        unix::io::{AsRawFd, RawFd},
+    },
+    sync::Arc,
 };
 
 /// A socket map file descriptor.
-#[derive(Copy, Clone)]
+#[derive(Clone)]
-pub struct SockMapFd<'f>(BorrowedFd<'f>);
+pub struct SockMapFd(Arc<OwnedFd>);
 
-impl AsRawFd for SockMapFd<'_> {
+impl AsRawFd for SockMapFd {
     fn as_raw_fd(&self) -> RawFd {
         self.0.as_raw_fd()
     }
 }
 
-impl AsFd for SockMapFd<'_> {
+impl AsFd for SockMapFd {
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.0.as_fd()
     }

aya/src/maps/sock/sock_hash.rs

@@ -49,10 +49,9 @@ use crate::{
 /// let mut intercept_egress = SockHash::<_, u32>::try_from(bpf.map("INTERCEPT_EGRESS").unwrap())?;
 /// let map_fd = intercept_egress.fd()?;
 ///
-/// // TODO (AM) : figure out lifetimes
+/// let prog: &mut SkMsg = bpf.program_mut("intercept_egress_packet").unwrap().try_into()?;
-/// // let prog: &mut SkMsg = bpf.program_mut("intercept_egress_packet").unwrap().try_into()?;
+/// prog.load()?;
-/// // prog.load()?;
+/// prog.attach(map_fd)?;
-/// // prog.attach(map_fd)?;
 ///
 /// let mut client = TcpStream::connect("127.0.0.1:1234")?;
 /// let mut intercept_egress = SockHash::try_from(bpf.map_mut("INTERCEPT_EGRESS").unwrap())?;
@@ -109,8 +108,10 @@ impl<T: Borrow<MapData>, K: Pod> SockHash<T, K> {
     ///
     /// The returned file descriptor can be used to attach programs that work with
     /// socket maps, like [`SkMsg`](crate::programs::SkMsg) and [`SkSkb`](crate::programs::SkSkb).
-    pub fn fd(&self) -> Result<SockMapFd<'_>, MapError> {
+    pub fn fd(&self) -> Result<SockMapFd, MapError> {
-        Ok(SockMapFd(self.inner.borrow().fd_or_err()?))
+        Ok(SockMapFd(
+            self.inner.borrow().fd.clone().ok_or(MapError::NotCreated)?,
+        ))
     }
 }
 

aya/src/maps/sock/sock_map.rs

@@ -33,10 +33,9 @@ use crate::{
 /// let intercept_ingress = SockMap::try_from(bpf.map("INTERCEPT_INGRESS").unwrap())?;
 /// let map_fd = intercept_ingress.fd()?;
 ///
-/// // TODO (AM): figure out lifetimes
+/// let prog: &mut SkSkb = bpf.program_mut("intercept_ingress_packet").unwrap().try_into()?;
-/// // let prog: &mut SkSkb = bpf.program_mut("intercept_ingress_packet").unwrap().try_into()?;
+/// prog.load()?;
-/// // prog.load()?;
+/// prog.attach(map_fd)?;
-/// // prog.attach(map_fd)?;
 ///
 /// # Ok::<(), aya::BpfError>(())
 /// ```
@@ -65,8 +64,10 @@ impl<T: Borrow<MapData>> SockMap<T> {
     ///
     /// The returned file descriptor can be used to attach programs that work with
     /// socket maps, like [`SkMsg`](crate::programs::SkMsg) and [`SkSkb`](crate::programs::SkSkb).
-    pub fn fd(&self) -> Result<SockMapFd<'_>, MapError> {
+    pub fn fd(&self) -> Result<SockMapFd, MapError> {
-        Ok(SockMapFd(self.inner.borrow().fd_or_err()?))
+        Ok(SockMapFd(
+            self.inner.borrow().fd.clone().ok_or(MapError::NotCreated)?,
+        ))
     }
 }
 

aya/src/programs/extension.rs

@@ -42,11 +42,9 @@ pub enum ExtensionError {
 /// prog.attach("eth0", XdpFlags::default())?;
 ///
 /// let prog_fd = prog.fd().unwrap();
-/// // TODO (AM): can't borrow here becauase prog_fd is holding a reference already
+/// let ext: &mut Extension = bpf.program_mut("extension").unwrap().try_into()?;
-/// // need to confirm what the API wants to be
+/// ext.load(prog_fd, "function_to_replace")?;
-/// // let ext: &mut Extension = bpf.program_mut("extension").unwrap().try_into()?;
+/// ext.attach()?;
-/// // ext.load(prog_fd, "function_to_replace")?;
-/// // ext.attach()?;
 /// Ok::<(), aya::BpfError>(())
 /// ```
 #[derive(Debug)]

aya/src/programs/mod.rs

@@ -73,6 +73,7 @@ use std::{
         unix::io::{AsRawFd, RawFd},
     },
     path::{Path, PathBuf},
+    sync::Arc,
 };
 use thiserror::Error;
 
@@ -217,16 +218,16 @@ pub enum ProgramError {
 }
 
 /// A [`Program`] file descriptor.
-#[derive(Copy, Clone)]
+#[derive(Clone)]
-pub struct ProgramFd<'f>(BorrowedFd<'f>);
+pub struct ProgramFd(Arc<OwnedFd>);
 
-impl AsRawFd for ProgramFd<'_> {
+impl AsRawFd for ProgramFd {
     fn as_raw_fd(&self) -> RawFd {
         self.0.as_raw_fd()
     }
 }
 
-impl AsFd for ProgramFd<'_> {
+impl AsFd for ProgramFd {
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.0.as_fd()
     }
@@ -415,7 +416,7 @@ impl Program {
 pub(crate) struct ProgramData<T: Link> {
     pub(crate) name: Option<String>,
     pub(crate) obj: Option<(obj::Program, obj::Function)>,
-    pub(crate) fd: Option<OwnedFd>,
+    pub(crate) fd: Option<Arc<OwnedFd>>,
     pub(crate) links: LinkMap<T>,
     pub(crate) expected_attach_type: Option<bpf_attach_type>,
     pub(crate) attach_btf_obj_fd: Option<OwnedFd>,
@@ -476,7 +477,7 @@ impl<T: Link> ProgramData<T> {
         Ok(ProgramData {
             name,
             obj: None,
-            fd: Some(fd),
+            fd: Some(Arc::new(fd)),
             links: LinkMap::new(),
             expected_attach_type: None,
             attach_btf_obj_fd,
@@ -630,7 +631,7 @@ fn load_program<T: Link>(
 
     match ret {
         Ok(prog_fd) => {
-            *fd = Some(prog_fd);
+            *fd = Some(Arc::new(prog_fd));
             Ok(())
         }
         Err((_, io_error)) => {
@@ -739,8 +740,9 @@ macro_rules! impl_fd {
         $(
             impl $struct_name {
                 /// Returns the file descriptor of this Program.
-                pub fn fd(&self) -> Option<ProgramFd<'_>> {
+                pub fn fd(&self) -> Option<ProgramFd> {
-                    self.data.fd.as_ref().map(|fd| ProgramFd(fd.as_fd()))
+                    let fd = self.data.fd.clone()?;
+                    Some(ProgramFd(fd))
                 }
             }
         )+

aya/src/programs/sk_msg.rs

@@ -46,10 +46,9 @@ use crate::{
 /// let intercept_egress: SockHash<_, u32> = bpf.map("INTERCEPT_EGRESS").unwrap().try_into()?;
 /// let map_fd = intercept_egress.fd()?;
 ///
-/// // TODO (AM): Figure out lifetimes
+/// let prog: &mut SkMsg = bpf.program_mut("intercept_egress_packet").unwrap().try_into()?;
-/// // let prog: &mut SkMsg = bpf.program_mut("intercept_egress_packet").unwrap().try_into()?;
+/// prog.load()?;
-/// // prog.load()?;
+/// prog.attach(map_fd)?;
-/// // prog.attach(map_fd)?;
 ///
 /// let mut client = TcpStream::connect("127.0.0.1:1234")?;
 /// let mut intercept_egress: SockHash<_, u32> = bpf.map_mut("INTERCEPT_EGRESS").unwrap().try_into()?;
@@ -79,7 +78,7 @@ impl SkMsg {
     /// Attaches the program to the given sockmap.
     ///
     /// The returned value can be used to detach, see [SkMsg::detach].
-    pub fn attach(&mut self, map: SockMapFd<'_>) -> Result<SkMsgLinkId, ProgramError> {
+    pub fn attach(&mut self, map: SockMapFd) -> Result<SkMsgLinkId, ProgramError> {
         let prog_fd = self.data.fd_or_err()?;
         let map_fd = map.as_fd();
 

aya/src/programs/sk_skb.rs

@@ -47,10 +47,9 @@ pub enum SkSkbKind {
 /// let intercept_ingress: SockMap<_> = bpf.map("INTERCEPT_INGRESS").unwrap().try_into()?;
 /// let map_fd = intercept_ingress.fd()?;
 ///
-/// // TODO (AM): figure out lifetimes
+/// let prog: &mut SkSkb = bpf.program_mut("intercept_ingress_packet").unwrap().try_into()?;
-/// // let prog: &mut SkSkb = bpf.program_mut("intercept_ingress_packet").unwrap().try_into()?;
+/// prog.load()?;
-/// // prog.load()?;
+/// prog.attach(map_fd)?;
-/// // prog.attach(map_fd)?;
 ///
 /// # Ok::<(), aya::BpfError>(())
 /// ```
@@ -74,7 +73,7 @@ impl SkSkb {
     /// Attaches the program to the given socket map.
     ///
     /// The returned value can be used to detach, see [SkSkb::detach].
-    pub fn attach(&mut self, map: SockMapFd<'_>) -> Result<SkSkbLinkId, ProgramError> {
+    pub fn attach(&mut self, map: SockMapFd) -> Result<SkSkbLinkId, ProgramError> {
         let prog_fd = self.data.fd_or_err()?;
         let map_fd = map.as_fd();