maps: MapFd and SockMapFd are owned

`MapData::fd` is now a `MapFd`. This means that `MapData` now closes the file descriptor on drop. In the future we might consider making `MapFd` hold a `BorrowedFd` but this requires API design work due to overlapping borrows. Since `SockMapFd` is no longer `Copy`, attach methods to take it by reference to allow callers to use it multiple times as they are accustomed to doing. `SockMapFd` implements `try_clone`. `MapFd` and `SockMapFd` are now returned by reference to allow callers to avoid file descriptor cloning when desired. This is an API breaking change. Updates #612.
aya-rs · Sep 18, 2023 · f415926 · f415926
1 parent 96c8bc9
commit f415926
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diff --git a/aya-obj/src/lib.rs b/aya-obj/src/lib.rs
@@ -77,6 +77,12 @@ mod std {
         pub use core_error::Error;
     }
     pub use core::*;
+
+    pub mod os {
+        pub mod fd {
+            pub type RawFd = core::ffi::c_int;
+        }
+    }
 }
 
 pub mod btf;

diff --git a/aya-obj/src/relocation.rs b/aya-obj/src/relocation.rs
@@ -105,7 +105,7 @@ pub(crate) struct Symbol {
 
 impl Object {
     /// Relocates the map references
-    pub fn relocate_maps<'a, I: Iterator<Item = (&'a str, i32, &'a Map)>>(
+    pub fn relocate_maps<'a, I: Iterator<Item = (&'a str, std::os::fd::RawFd, &'a Map)>>(
         &mut self,
         maps: I,
         text_sections: &HashSet<usize>,
@@ -178,8 +178,8 @@ impl Object {
 fn relocate_maps<'a, I: Iterator<Item = &'a Relocation>>(
     fun: &mut Function,
     relocations: I,
-    maps_by_section: &HashMap<usize, (&str, i32, &Map)>,
-    maps_by_symbol: &HashMap<usize, (&str, i32, &Map)>,
+    maps_by_section: &HashMap<usize, (&str, std::os::fd::RawFd, &Map)>,
+    maps_by_symbol: &HashMap<usize, (&str, std::os::fd::RawFd, &Map)>,
     symbol_table: &HashMap<usize, Symbol>,
     text_sections: &HashSet<usize>,
 ) -> Result<(), RelocationError> {

diff --git a/aya/src/bpf.rs b/aya/src/bpf.rs
@@ -3,7 +3,7 @@ use std::{
     collections::{HashMap, HashSet},
     fs, io,
     os::{
-        fd::{AsFd as _, OwnedFd},
+        fd::{AsFd as _, AsRawFd as _, OwnedFd},
         raw::c_int,
     },
     path::{Path, PathBuf},
@@ -482,17 +482,17 @@ impl<'a> BpfLoader<'a> {
                     MapData::create_pinned(path, obj, &name, btf_fd)?
                 }
             };
-            let fd = map.fd;
-            if !map.obj.data().is_empty() && map.obj.section_kind() != BpfSectionKind::Bss {
-                bpf_map_update_elem_ptr(fd, &0 as *const _, map.obj.data_mut().as_mut_ptr(), 0)
+            let MapData { obj, fd, pinned: _ } = &mut map;
+            if !obj.data().is_empty() && obj.section_kind() != BpfSectionKind::Bss {
+                bpf_map_update_elem_ptr(fd.as_fd(), &0 as *const _, obj.data_mut().as_mut_ptr(), 0)
                     .map_err(|(_, io_error)| SyscallError {
                         call: "bpf_map_update_elem",
                         io_error,
                     })
                     .map_err(MapError::from)?;
             }
-            if map.obj.section_kind() == BpfSectionKind::Rodata {
-                bpf_map_freeze(fd)
+            if obj.section_kind() == BpfSectionKind::Rodata {
+                bpf_map_freeze(fd.as_fd())
                     .map_err(|(_, io_error)| SyscallError {
                         call: "bpf_map_freeze",
                         io_error,
@@ -510,7 +510,7 @@ impl<'a> BpfLoader<'a> {
 
         obj.relocate_maps(
             maps.iter()
-                .map(|(s, data)| (s.as_str(), data.fd, &data.obj)),
+                .map(|(s, data)| (s.as_str(), data.fd().as_fd().as_raw_fd(), &data.obj)),
             &text_sections,
         )?;
         obj.relocate_calls(&text_sections)?;

diff --git a/aya/src/maps/array/array.rs b/aya/src/maps/array/array.rs
@@ -1,6 +1,7 @@
 use std::{
     borrow::{Borrow, BorrowMut},
     marker::PhantomData,
+    os::fd::AsFd as _,
 };
 
 use crate::{
@@ -61,7 +62,7 @@ impl<T: Borrow<MapData>, V: Pod> Array<T, V> {
     pub fn get(&self, index: &u32, flags: u64) -> Result<V, MapError> {
         let data = self.inner.borrow();
         check_bounds(data, *index)?;
-        let fd = data.fd;
+        let fd = data.fd().as_fd();
 
         let value =
             bpf_map_lookup_elem(fd, index, flags).map_err(|(_, io_error)| SyscallError {
@@ -88,7 +89,7 @@ impl<T: BorrowMut<MapData>, V: Pod> Array<T, V> {
     pub fn set(&mut self, index: u32, value: impl Borrow<V>, flags: u64) -> Result<(), MapError> {
         let data = self.inner.borrow_mut();
         check_bounds(data, index)?;
-        let fd = data.fd;
+        let fd = data.fd().as_fd();
         bpf_map_update_elem(fd, Some(&index), value.borrow(), flags).map_err(|(_, io_error)| {
             SyscallError {
                 call: "bpf_map_update_elem",

diff --git a/aya/src/maps/array/per_cpu_array.rs b/aya/src/maps/array/per_cpu_array.rs
@@ -1,6 +1,7 @@
 use std::{
     borrow::{Borrow, BorrowMut},
     marker::PhantomData,
+    os::fd::AsFd as _,
 };
 
 use crate::{
@@ -80,7 +81,7 @@ impl<T: Borrow<MapData>, V: Pod> PerCpuArray<T, V> {
     pub fn get(&self, index: &u32, flags: u64) -> Result<PerCpuValues<V>, MapError> {
         let data = self.inner.borrow();
         check_bounds(data, *index)?;
-        let fd = data.fd;
+        let fd = data.fd().as_fd();
 
         let value = bpf_map_lookup_elem_per_cpu(fd, index, flags).map_err(|(_, io_error)| {
             SyscallError {
@@ -108,7 +109,7 @@ impl<T: BorrowMut<MapData>, V: Pod> PerCpuArray<T, V> {
     pub fn set(&mut self, index: u32, values: PerCpuValues<V>, flags: u64) -> Result<(), MapError> {
         let data = self.inner.borrow_mut();
         check_bounds(data, index)?;
-        let fd = data.fd;
+        let fd = data.fd().as_fd();
 
         bpf_map_update_elem_per_cpu(fd, &index, &values, flags).map_err(|(_, io_error)| {
             SyscallError {

diff --git a/aya/src/maps/array/program_array.rs b/aya/src/maps/array/program_array.rs
@@ -74,7 +74,7 @@ impl<T: BorrowMut<MapData>> ProgramArray<T> {
     pub fn set(&mut self, index: u32, program: &ProgramFd, flags: u64) -> Result<(), MapError> {
         let data = self.inner.borrow_mut();
         check_bounds(data, index)?;
-        let fd = data.fd;
+        let fd = data.fd().as_fd();
         let prog_fd = program.as_fd();
         let prog_fd = prog_fd.as_raw_fd();
 
@@ -94,7 +94,7 @@ impl<T: BorrowMut<MapData>> ProgramArray<T> {
     pub fn clear_index(&mut self, index: &u32) -> Result<(), MapError> {
         let data = self.inner.borrow_mut();
         check_bounds(data, *index)?;
-        let fd = self.inner.borrow_mut().fd;
+        let fd = data.fd().as_fd();
 
         bpf_map_delete_elem(fd, index)
             .map(|_| ())

diff --git a/aya/src/maps/bloom_filter.rs b/aya/src/maps/bloom_filter.rs
@@ -2,6 +2,7 @@
 use std::{
     borrow::{Borrow, BorrowMut},
     marker::PhantomData,
+    os::fd::AsFd as _,
 };
 
 use crate::{
@@ -52,7 +53,7 @@ impl<T: Borrow<MapData>, V: Pod> BloomFilter<T, V> {
 
     /// Query the existence of the element.
     pub fn contains(&self, mut value: &V, flags: u64) -> Result<(), MapError> {
-        let fd = self.inner.borrow().fd;
+        let fd = self.inner.borrow().fd().as_fd();
 
         bpf_map_lookup_elem_ptr::<u32, _>(fd, None, &mut value, flags)
             .map_err(|(_, io_error)| SyscallError {
@@ -67,7 +68,7 @@ impl<T: Borrow<MapData>, V: Pod> BloomFilter<T, V> {
 impl<T: BorrowMut<MapData>, V: Pod> BloomFilter<T, V> {
     /// Inserts a value into the map.
     pub fn insert(&mut self, value: impl Borrow<V>, flags: u64) -> Result<(), MapError> {
-        let fd = self.inner.borrow_mut().fd;
+        let fd = self.inner.borrow_mut().fd().as_fd();
         bpf_map_push_elem(fd, value.borrow(), flags).map_err(|(_, io_error)| SyscallError {
             call: "bpf_map_push_elem",
             io_error,

diff --git a/aya/src/maps/hash_map/hash_map.rs b/aya/src/maps/hash_map/hash_map.rs
@@ -1,6 +1,7 @@
 use std::{
     borrow::{Borrow, BorrowMut},
     marker::PhantomData,
+    os::fd::AsFd as _,
 };
 
 use crate::{
@@ -52,7 +53,7 @@ impl<T: Borrow<MapData>, K: Pod, V: Pod> HashMap<T, K, V> {
 
     /// Returns a copy of the value associated with the key.
     pub fn get(&self, key: &K, flags: u64) -> Result<V, MapError> {
-        let fd = self.inner.borrow().fd;
+        let fd = self.inner.borrow().fd().as_fd();
         let value = bpf_map_lookup_elem(fd, key, flags).map_err(|(_, io_error)| SyscallError {
             call: "bpf_map_lookup_elem",
             io_error,

diff --git a/aya/src/maps/hash_map/mod.rs b/aya/src/maps/hash_map/mod.rs
@@ -4,6 +4,7 @@ use crate::{
     sys::{bpf_map_delete_elem, bpf_map_update_elem, SyscallError},
     Pod,
 };
+use std::os::fd::AsFd as _;
 
 #[allow(clippy::module_inception)]
 mod hash_map;
@@ -20,7 +21,7 @@ pub(crate) fn insert<K: Pod, V: Pod>(
     value: &V,
     flags: u64,
 ) -> Result<(), MapError> {
-    let fd = map.fd;
+    let fd = map.fd().as_fd();
     bpf_map_update_elem(fd, Some(key), value, flags).map_err(|(_, io_error)| SyscallError {
         call: "bpf_map_update_elem",
         io_error,
@@ -30,7 +31,7 @@ pub(crate) fn insert<K: Pod, V: Pod>(
 }
 
 pub(crate) fn remove<K: Pod>(map: &MapData, key: &K) -> Result<(), MapError> {
-    let fd = map.fd;
+    let fd = map.fd().as_fd();
     bpf_map_delete_elem(fd, key)
         .map(|_| ())
         .map_err(|(_, io_error)| {

diff --git a/aya/src/maps/hash_map/per_cpu_hash_map.rs b/aya/src/maps/hash_map/per_cpu_hash_map.rs
@@ -2,6 +2,7 @@
 use std::{
     borrow::{Borrow, BorrowMut},
     marker::PhantomData,
+    os::fd::AsFd as _,
 };
 
 use crate::{
@@ -61,7 +62,7 @@ impl<T: Borrow<MapData>, K: Pod, V: Pod> PerCpuHashMap<T, K, V> {
 
     /// Returns a slice of values - one for each CPU - associated with the key.
     pub fn get(&self, key: &K, flags: u64) -> Result<PerCpuValues<V>, MapError> {
-        let fd = self.inner.borrow().fd;
+        let fd = self.inner.borrow().fd().as_fd();
         let values =
             bpf_map_lookup_elem_per_cpu(fd, key, flags).map_err(|(_, io_error)| SyscallError {
                 call: "bpf_map_lookup_elem",
@@ -118,7 +119,7 @@ impl<T: BorrowMut<MapData>, K: Pod, V: Pod> PerCpuHashMap<T, K, V> {
         values: PerCpuValues<V>,
         flags: u64,
     ) -> Result<(), MapError> {
-        let fd = self.inner.borrow_mut().fd;
+        let fd = self.inner.borrow_mut().fd().as_fd();
         bpf_map_update_elem_per_cpu(fd, key.borrow(), &values, flags).map_err(
             |(_, io_error)| SyscallError {
                 call: "bpf_map_update_elem",

diff --git a/aya/src/maps/lpm_trie.rs b/aya/src/maps/lpm_trie.rs
@@ -2,6 +2,7 @@
 use std::{
     borrow::{Borrow, BorrowMut},
     marker::PhantomData,
+    os::fd::AsFd as _,
 };
 
 use crate::{
@@ -126,7 +127,7 @@ impl<T: Borrow<MapData>, K: Pod, V: Pod> LpmTrie<T, K, V> {
 
     /// Returns a copy of the value associated with the longest prefix matching key in the LpmTrie.
     pub fn get(&self, key: &Key<K>, flags: u64) -> Result<V, MapError> {
-        let fd = self.inner.borrow().fd;
+        let fd = self.inner.borrow().fd().as_fd();
         let value = bpf_map_lookup_elem(fd, key, flags).map_err(|(_, io_error)| SyscallError {
             call: "bpf_map_lookup_elem",
             io_error,
@@ -155,7 +156,7 @@ impl<T: BorrowMut<MapData>, K: Pod, V: Pod> LpmTrie<T, K, V> {
         value: impl Borrow<V>,
         flags: u64,
     ) -> Result<(), MapError> {
-        let fd = self.inner.borrow().fd;
+        let fd = self.inner.borrow().fd().as_fd();
         bpf_map_update_elem(fd, Some(key), value.borrow(), flags).map_err(|(_, io_error)| {
             SyscallError {
                 call: "bpf_map_update_elem",
@@ -170,7 +171,7 @@ impl<T: BorrowMut<MapData>, K: Pod, V: Pod> LpmTrie<T, K, V> {
     ///
     /// Both the prefix and data must match exactly - this method does not do a longest prefix match.
     pub fn remove(&mut self, key: &Key<K>) -> Result<(), MapError> {
-        let fd = self.inner.borrow().fd;
+        let fd = self.inner.borrow().fd().as_fd();
         bpf_map_delete_elem(fd, key)
             .map(|_| ())
             .map_err(|(_, io_error)| {