BpfMap - add BpfMapRO.init() support
Really we need to fix the inheritance to make
BpfMapRO the parent class of BpfMap:
but that's a far more difficult thing to do,
so in the short term we punt like this.
This makes BpfMapRO a little bit more usable,
and allows a slow transition across the codebase...
Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I1c5112db70e9e523c113cba536fbe19422b4d3f3
diff --git a/staticlibs/native/bpf_headers/include/bpf/BpfMap.h b/staticlibs/native/bpf_headers/include/bpf/BpfMap.h
index 0054753..afb6fdf 100644
--- a/staticlibs/native/bpf_headers/include/bpf/BpfMap.h
+++ b/staticlibs/native/bpf_headers/include/bpf/BpfMap.h
@@ -103,8 +103,29 @@
return {};
}
+ protected:
+ [[clang::reinitializes]] base::Result<void> init(const char* path, int fd) {
+ mMapFd.reset(fd);
+ if (mMapFd == -1) {
+ return ErrnoErrorf("Pinned map not accessible or does not exist: ({})", path);
+ }
+ if (isAtLeastKernelVersion(4, 14, 0)) {
+ // Normally we should return an error here instead of calling abort,
+ // but this cannot happen at runtime without a massive code bug (K/V type mismatch)
+ // and as such it's better to just blow the system up and let the developer fix it.
+ // Crashes are much more likely to be noticed than logs and missing functionality.
+ if (bpfGetFdKeySize(mMapFd) != sizeof(Key)) abort();
+ if (bpfGetFdValueSize(mMapFd) != sizeof(Value)) abort();
+ }
+ return {};
+ }
+
+ public:
// Function that tries to get map from a pinned path.
- [[clang::reinitializes]] base::Result<void> init(const char* path);
+ [[clang::reinitializes]] base::Result<void> init(const char* path) {
+ return init(path, mapRetrieveRW(path));
+ }
+
#ifdef BPF_MAP_MAKE_VISIBLE_FOR_TESTING
// due to Android SELinux limitations which prevent map creation by anyone besides the bpfloader
@@ -210,23 +231,6 @@
};
template <class Key, class Value>
-base::Result<void> BpfMap<Key, Value>::init(const char* path) {
- mMapFd.reset(mapRetrieveRW(path));
- if (mMapFd == -1) {
- return ErrnoErrorf("Pinned map not accessible or does not exist: ({})", path);
- }
- if (isAtLeastKernelVersion(4, 14, 0)) {
- // Normally we should return an error here instead of calling abort,
- // but this cannot happen at runtime without a massive code bug (K/V type mismatch)
- // and as such it's better to just blow the system up and let the developer fix it.
- // Crashes are much more likely to be noticed than logs and missing functionality.
- if (bpfGetFdKeySize(mMapFd) != sizeof(Key)) abort();
- if (bpfGetFdValueSize(mMapFd) != sizeof(Value)) abort();
- }
- return {};
-}
-
-template <class Key, class Value>
base::Result<void> BpfMap<Key, Value>::iterate(
const std::function<base::Result<void>(const Key& key, const BpfMap<Key, Value>& map)>&
filter) const {
@@ -292,8 +296,15 @@
template <class Key, class Value>
class BpfMapRO : public BpfMap<Key, Value> {
public:
+ BpfMapRO<Key, Value>() {};
+
explicit BpfMapRO<Key, Value>(const char* pathname)
: BpfMap<Key, Value>(pathname, BPF_F_RDONLY) {}
+
+ // Function that tries to get map from a pinned path.
+ [[clang::reinitializes]] base::Result<void> init(const char* path) {
+ return BpfMap<Key,Value>::init(path, mapRetrieveRO(path));
+ }
};
} // namespace bpf