commit ce89f50035e3b964e842df95c14900505abcad63
author Ryan Zuklie <rzuklie@google.com> Thu Dec 15 16:14:32 2022 -0800
committer Ryan Zuklie <rzuklie@google.com> Mon Dec 19 14:39:31 2022 -0800
tree f97d759199dca4825c08984eda24244340504dcc
parent 4a7ca6f2b1735c9df17bba1c7b0709274dcbe6f7

Add option to skip map/prog based on build type

This feature allows skipping a program or map based on the type of the
build. This allows things like userdebug-only programs.

Bug: 246985031
Test: added test program and watched it skipped on userdebug
Change-Id: I981e3447b40751926cbfd1692e13772ec582d3d4

libbpf_android/Loader.cpp

diff --git a/libbpf_android/Loader.cpp b/libbpf_android/Loader.cpp
index f1a0123..24e5a90 100644
--- a/libbpf_android/Loader.cpp
+++ b/libbpf_android/Loader.cpp
@@ -30,9 +30,9 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
-// This is BpfLoader v0.31
+// This is BpfLoader v0.32
 #define BPFLOADER_VERSION_MAJOR 0u
-#define BPFLOADER_VERSION_MINOR 31u
+#define BPFLOADER_VERSION_MINOR 32u
 #define BPFLOADER_VERSION ((BPFLOADER_VERSION_MAJOR << 16) | BPFLOADER_VERSION_MINOR)
 
 #include "bpf/BpfUtils.h"
@@ -57,6 +57,7 @@
 #include <android-base/file.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>
+#include <cutils/properties.h>
 
 #define BPF_FS_PATH "/sys/fs/bpf/"
 
@@ -74,9 +75,20 @@
 using std::string;
 using std::vector;
 
+static std::string getBuildTypeInternal() {
+    char value[PROPERTY_VALUE_MAX] = {};
+    (void)property_get("ro.build.type", value, "unknown");  // ignore length
+    return value;
+}
+
 namespace android {
 namespace bpf {
 
+const std::string& getBuildType() {
+    static std::string t = getBuildTypeInternal();
+    return t;
+}
+
 constexpr const char* lookupSelinuxContext(const domain d, const char* const unspecified = "") {
     switch (d) {
         case domain::unspecified:   return unspecified;
@@ -769,6 +781,14 @@
             continue;
         }
 
+        if ((md[i].ignore_on_eng && isEng()) || (md[i].ignore_on_user && isUser()) ||
+            (md[i].ignore_on_userdebug && isUserdebug())) {
+            ALOGI("skipping map %s which is ignored on %s builds", mapNames[i].c_str(),
+                  getBuildType().c_str());
+            mapFds.push_back(unique_fd());
+            continue;
+        }
+
         enum bpf_map_type type = md[i].type;
         if (type == BPF_MAP_TYPE_DEVMAP_HASH && !isAtLeastKernelVersion(5, 4, 0)) {
             // On Linux Kernels older than 5.4 this map type doesn't exist, but it can kind
@@ -1011,6 +1031,14 @@
               bpfMinVer, bpfMaxVer);
         if (BPFLOADER_VERSION < bpfMinVer) continue;
         if (BPFLOADER_VERSION >= bpfMaxVer) continue;
+
+        if ((cs[i].prog_def->ignore_on_eng && isEng()) ||
+            (cs[i].prog_def->ignore_on_user && isUser()) ||
+            (cs[i].prog_def->ignore_on_userdebug && isUserdebug())) {
+            ALOGD("cs[%d].name:%s is ignored on %s builds", i, name.c_str(),
+                  getBuildType().c_str());
+        }
+
         if (unrecognized(pin_subdir)) return -ENOTDIR;
 
         if (specified(selinux_context)) {