commit 0e2fe7c95de3ee2162efc576234d50f0f7340ab2
author Treehugger Robot <treehugger-gerrit@google.com> Thu Jun 23 20:00:23 2022 +0000
committer Gerrit Code Review <noreply-gerritcodereview@google.com> Thu Jun 23 20:00:23 2022 +0000
tree 32b3fb29ed498730cd000f99a903f2c404b934fe
parent e182ece901c788a349f12591e93b8d53b65e609e
parent 0ce7758487675d19a2acb9d7efe684f049375d5c

Merge "add more comments about bpfGetFd... and kernel version compatibility"

staticlibs/native/bpf_headers/include/bpf/BpfMap.h

diff --git a/staticlibs/native/bpf_headers/include/bpf/BpfMap.h b/staticlibs/native/bpf_headers/include/bpf/BpfMap.h
index 297b200..47256fa 100644
--- a/staticlibs/native/bpf_headers/include/bpf/BpfMap.h
+++ b/staticlibs/native/bpf_headers/include/bpf/BpfMap.h
@@ -50,10 +50,8 @@
     // (later on, for testing, we still make available a copy assignment operator)
     BpfMap<Key, Value>(const BpfMap<Key, Value>&) = delete;
 
-  protected:
-    // flag must be within BPF_OBJ_FLAG_MASK, ie. 0, BPF_F_RDONLY, BPF_F_WRONLY
-    BpfMap<Key, Value>(const char* pathname, uint32_t flags) {
-        mMapFd.reset(mapRetrieve(pathname, flags));
+  private:
+    void abortOnKeyOrValueSizeMismatch() {
         if (!mMapFd.ok()) abort();
         if (isAtLeastKernelVersion(4, 14, 0)) {
             if (bpfGetFdKeySize(mMapFd) != sizeof(Key)) abort();
@@ -61,6 +59,13 @@
         }
     }
 
+  protected:
+    // flag must be within BPF_OBJ_FLAG_MASK, ie. 0, BPF_F_RDONLY, BPF_F_WRONLY
+    BpfMap<Key, Value>(const char* pathname, uint32_t flags) {
+        mMapFd.reset(mapRetrieve(pathname, flags));
+        abortOnKeyOrValueSizeMismatch();
+    }
+
   public:
     explicit BpfMap<Key, Value>(const char* pathname) : BpfMap<Key, Value>(pathname, 0) {}
 
@@ -117,14 +122,11 @@
         if (!mMapFd.ok()) {
             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();
-        }
+        // 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.
+        abortOnKeyOrValueSizeMismatch();
         return {};
     }
 
@@ -202,11 +204,7 @@
     // check BpfMap.isValid() and look at errno and see why systemcall() failed.
     [[clang::reinitializes]] void reset(int fd) {
         mMapFd.reset(fd);
-        if ((fd >= 0) && isAtLeastKernelVersion(4, 14, 0)) {
-            if (bpfGetFdKeySize(mMapFd) != sizeof(Key)) abort();
-            if (bpfGetFdValueSize(mMapFd) != sizeof(Value)) abort();
-            if (bpfGetFdMapFlags(mMapFd) != 0) abort(); // TODO: fix for BpfMapRO
-        }
+        if (mMapFd.ok()) abortOnKeyOrValueSizeMismatch();
     }
 #endif
 

staticlibs/native/bpf_headers/include/bpf/bpf_helpers.h

diff --git a/staticlibs/native/bpf_headers/include/bpf/bpf_helpers.h b/staticlibs/native/bpf_headers/include/bpf/bpf_helpers.h
index ae3ad2c..8bc8eb1 100644
--- a/staticlibs/native/bpf_headers/include/bpf/bpf_helpers.h
+++ b/staticlibs/native/bpf_headers/include/bpf/bpf_helpers.h
@@ -30,6 +30,13 @@
 // Android T / 13 Beta 3 (api level 33) - added support for 'netd_shared'
 #define BPFLOADER_T_BETA3_VERSION 13u
 
+// v0.18 added support for shared and pindir, but still ignores selinux_content
+// v0.19 added support for selinux_content along with the required selinux changes
+// and should be available starting with Android T Beta 4
+//
+// Android T / 13 (api level 33) - support for shared/selinux_context/pindir
+#define BPFLOADER_T_VERSION 19u
+
 /* For mainline module use, you can #define BPFLOADER_{MIN/MAX}_VER
  * before #include "bpf_helpers.h" to change which bpfloaders will
  * process the resulting .o file.