From 1758f413a2bf3193170ef2a082d7747489eba64f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= <maze@google.com>
Date: Mon, 13 Jan 2025 12:18:47 -0800
Subject: [PATCH] Check supported kernel version in V and 25Q2+
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V requires 4.19+ and 25Q2+ requires 5.4+

(while 25Q4 will presumably further bump to 5.10+)

On aosp/main we currently have:
  ro.build.version.sdk=35
    - which is returned by android_get_device_api_level()
  ro.build.version.codename=Baklava
    - which is looked at by IsAtLeastPreReleaseCodename/GetCodename

This is because we're already past the aosp/main automerge into 25Q1 cutoff.

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I909d63406151fbafc15fa248133b9d1a5dc37bdb
---
 bpf/netd/BpfHandler.cpp | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/bpf/netd/BpfHandler.cpp b/bpf/netd/BpfHandler.cpp
index 340acda0ad..bcd0cbac46 100644
--- a/bpf/netd/BpfHandler.cpp
+++ b/bpf/netd/BpfHandler.cpp
@@ -70,6 +70,13 @@ static Status checkProgramAccessible(const char* programPath) {
     return netdutils::status::ok;
 }
 
+// Checks if the device is running on release version of Android 25Q2 or newer.
+static bool isAtLeast25Q2() {
+    return android_get_device_api_level() >= 36 ||
+           (android_get_device_api_level() == 35 &&
+            modules::sdklevel::detail::IsAtLeastPreReleaseCodename("Baklava"));
+}
+
 static Status initPrograms(const char* cg2_path) {
     if (!cg2_path) return Status("cg2_path is NULL");
 
@@ -91,6 +98,16 @@ static Status initPrograms(const char* cg2_path) {
         return Status("U+ platform with cg2_path != /sys/fs/cgroup is unsupported");
     }
 
+    // V bumps the kernel requirement up to 4.19
+    if (modules::sdklevel::IsAtLeastV() && !bpf::isAtLeastKernelVersion(4, 19, 0)) {
+        return Status("V+ platform with kernel version < 4.19.0 is unsupported");
+    }
+
+    // 25Q2 bumps the kernel requirement up to 5.4
+    if (isAtLeast25Q2() && !bpf::isAtLeastKernelVersion(5, 4, 0)) {
+        return Status("25Q2+ platform with kernel version < 5.4.0 is unsupported");
+    }
+
     unique_fd cg_fd(open(cg2_path, O_DIRECTORY | O_RDONLY | O_CLOEXEC));
     if (!cg_fd.ok()) {
         const int err = errno;