From 1404d12a7e29ab02225bc13fd36794f6c6206db1 Mon Sep 17 00:00:00 2001
From: Rafael Ortiz <rafael.ortiz@redcanary.com>
Date: Mon, 21 Jun 2021 10:29:01 -0400
Subject: [PATCH] add support for older (and newer) map definitions
---
aya/src/bpf.rs | 32 +++++++++-
aya/src/maps/hash_map/hash_map.rs | 12 +---
aya/src/maps/mod.rs | 4 +-
aya/src/obj/mod.rs | 97 ++++++++++++++++++-------------
4 files changed, 92 insertions(+), 53 deletions(-)
diff --git a/aya/src/bpf.rs b/aya/src/bpf.rs
index 91d3a3aa..b513f09b 100644
--- a/aya/src/bpf.rs
+++ b/aya/src/bpf.rs
@@ -50,13 +50,41 @@ unsafe_impl_pod!(i8, u8, i16, u16, i32, u32, i64, u64);
#[repr(C)]
#[derive(Copy, Clone, Debug)]
pub(crate) struct bpf_map_def {
+ // minimum features required by old BPF programs
pub(crate) map_type: u32,
pub(crate) key_size: u32,
pub(crate) value_size: u32,
pub(crate) max_entries: u32,
pub(crate) map_flags: u32,
- pub(crate) id: u32,
- pub(crate) pinning: u32,
+ // optional features
+ pub(crate) inner_map_fd: u32, // id
+ pub(crate) numa_node: u32, // pinning
+ pub(crate) map_name: [u8; BPF_OBJ_NAME_LEN],
+ pub(crate) map_ifindex: u32,
+ pub(crate) btf_id: u32,
+ pub(crate) btf_key_type_id: u32,
+ pub(crate) btf_value_type_id: u32,
+ pub(crate) btf_vmlinux_value_type_id: u32,
+}
+
+impl Default for bpf_map_def {
+ fn default() -> Self {
+ Self {
+ map_type: 0,
+ key_size: 0,
+ value_size: 0,
+ max_entries: 0,
+ map_flags: 0,
+ inner_map_fd: 0,
+ numa_node: 0,
+ map_name: [0u8; BPF_OBJ_NAME_LEN],
+ map_ifindex: 0,
+ btf_id: 0,
+ btf_key_type_id: 0,
+ btf_value_type_id: 0,
+ btf_vmlinux_value_type_id: 0
+ }
+ }
}
/// The main entry point into the library, used to work with eBPF programs and maps.
diff --git a/aya/src/maps/hash_map/hash_map.rs b/aya/src/maps/hash_map/hash_map.rs
index 63a260f9..1ba608f2 100644
--- a/aya/src/maps/hash_map/hash_map.rs
+++ b/aya/src/maps/hash_map/hash_map.rs
@@ -162,9 +162,7 @@ mod tests {
key_size: 4,
value_size: 4,
max_entries: 1024,
- map_flags: 0,
- id: 0,
- pinning: 0,
+ ..Default::default()
},
section_index: 0,
data: Vec::new(),
@@ -215,9 +213,7 @@ mod tests {
key_size: 4,
value_size: 4,
max_entries: 1024,
- map_flags: 0,
- id: 0,
- pinning: 0,
+ ..Default::default()
},
section_index: 0,
data: Vec::new(),
@@ -273,9 +269,7 @@ mod tests {
key_size: 4,
value_size: 4,
max_entries: 1024,
- map_flags: 0,
- id: 0,
- pinning: 0,
+ ..Default::default()
},
section_index: 0,
data: Vec::new(),
diff --git a/aya/src/maps/mod.rs b/aya/src/maps/mod.rs
index cb9176f7..f96e4b32 100644
--- a/aya/src/maps/mod.rs
+++ b/aya/src/maps/mod.rs
@@ -426,9 +426,7 @@ mod tests {
key_size: 4,
value_size: 4,
max_entries: 1024,
- map_flags: 0,
- id: 0,
- pinning: 0,
+ ..Default::default()
},
section_index: 0,
data: Vec::new(),
diff --git a/aya/src/obj/mod.rs b/aya/src/obj/mod.rs
index 45b1a3ce..5c714bb4 100644
--- a/aya/src/obj/mod.rs
+++ b/aya/src/obj/mod.rs
@@ -493,8 +493,7 @@ fn parse_map(section: &Section, name: &str) -> Result<Map, ParseError> {
value_size: section.data.len() as u32,
max_entries: 1,
map_flags: 0, /* FIXME: set rodata readonly */
- id: 0,
- pinning: 0,
+ ..Default::default()
};
(def, section.data.to_vec())
} else {
@@ -510,13 +509,31 @@ fn parse_map(section: &Section, name: &str) -> Result<Map, ParseError> {
}
fn parse_map_def(name: &str, data: &[u8]) -> Result<bpf_map_def, ParseError> {
- if mem::size_of::<bpf_map_def>() > data.len() {
+ if mem::size_of::<bpf_map_def>() < data.len() {
return Err(ParseError::InvalidMapDefinition {
name: name.to_owned(),
});
}
- Ok(unsafe { ptr::read_unaligned(data.as_ptr() as *const bpf_map_def) })
+ let mut map_def = bpf_map_def{
+ ..Default::default()
+ };
+
+ unsafe {
+ // std::ptr::copy is const, we can't use it because data.len() isn't known at
+ // compile time
+ let mut p = data.as_ptr();
+ let mut q = &mut map_def as *mut bpf_map_def as *mut u8;
+ for _ in 0..=data.len() {
+ *q = *p;
+ q = q.add(1);
+ p = p.add(1);
+ }
+ }
+
+ Ok(map_def)
+
+ //Ok(unsafe { ptr::read_unaligned(data.as_ptr() as *const bpf_map_def) })
}
fn copy_instructions(data: &[u8]) -> Result<Vec<bpf_insn>, ParseError> {
@@ -657,10 +674,19 @@ mod tests {
#[test]
fn test_parse_map_def() {
+ #![allow(unused_variables)] // map_def is used by the assertion
assert!(matches!(
- parse_map_def("foo", &[]),
+ parse_map_def("foo", &[0u8; std::mem::size_of::<bpf_map_def>() + 10]),
Err(ParseError::InvalidMapDefinition { .. })
));
+ let map_def = bpf_map_def {
+ map_type: 1,
+ key_size: 2,
+ value_size: 3,
+ max_entries: 4,
+ map_flags: 5,
+ ..Default::default()
+ };
assert!(matches!(
parse_map_def(
"foo",
@@ -670,32 +696,32 @@ mod tests {
value_size: 3,
max_entries: 4,
map_flags: 5,
- id: 0,
- pinning: 0
+ ..Default::default()
})
),
- Ok(bpf_map_def {
- map_type: 1,
- key_size: 2,
- value_size: 3,
- max_entries: 4,
- map_flags: 5,
- id: 0,
- pinning: 0
- })
+ Ok(map_def)
));
}
#[test]
fn test_parse_map_error() {
assert!(matches!(
- parse_map(&fake_section("maps/foo", &[]), "foo"),
+ parse_map(&fake_section("maps/foo", &[0u8; std::mem::size_of::<bpf_map_def>() + 10]), "foo"),
Err(ParseError::InvalidMapDefinition { .. })
))
}
#[test]
fn test_parse_map() {
+ #![allow(unused_variables)] // def is used by the assertion
+ let def = bpf_map_def {
+ map_type: 1,
+ key_size: 2,
+ value_size: 3,
+ max_entries: 4,
+ map_flags: 5,
+ ..Default::default()
+ };
assert!(matches!(
parse_map(
&fake_section(
@@ -706,8 +732,7 @@ mod tests {
value_size: 3,
max_entries: 4,
map_flags: 5,
- id: 0,
- pinning: 0
+ ..Default::default()
})
),
"foo"
@@ -715,15 +740,7 @@ mod tests {
Ok(Map {
section_index: 0,
name,
- def: bpf_map_def {
- map_type: 1,
- key_size: 2,
- value_size: 3,
- max_entries: 4,
- map_flags: 5,
- id: 0,
- pinning: 0
- },
+ def,
data
}) if name == "foo" && data.is_empty()
))
@@ -731,7 +748,18 @@ mod tests {
#[test]
fn test_parse_map_data() {
+ #![allow(unused_variables)] // def is used by the assertion
let map_data = b"map data";
+ let _map_type = BPF_MAP_TYPE_ARRAY;
+ let value_size = map_data.len() as u32;
+ let def = bpf_map_def {
+ map_type: _map_type as u32,
+ key_size: 4,
+ value_size,
+ max_entries: 1,
+ map_flags: 0,
+ ..Default::default()
+ };
assert!(matches!(
parse_map(
&fake_section(
@@ -743,15 +771,7 @@ mod tests {
Ok(Map {
section_index: 0,
name,
- def: bpf_map_def {
- map_type: _map_type,
- key_size: 4,
- value_size,
- max_entries: 1,
- map_flags: 0,
- id: 0,
- pinning: 0
- },
+ def,
data
}) if name == ".bss" && data == map_data && value_size == map_data.len() as u32
))
@@ -809,8 +829,7 @@ mod tests {
value_size: 3,
max_entries: 4,
map_flags: 5,
- id: 0,
- pinning: 0
+ ..Default::default()
})
),),
Ok(())