Merge "better compatibility for unusual Qualcomm/Mediatek cellular ARPHRD_* values"
diff --git a/Tethering/jni/com_android_networkstack_tethering_BpfUtils.cpp b/Tethering/jni/com_android_networkstack_tethering_BpfUtils.cpp
index 9838bf1..f9e4824 100644
--- a/Tethering/jni/com_android_networkstack_tethering_BpfUtils.cpp
+++ b/Tethering/jni/com_android_networkstack_tethering_BpfUtils.cpp
@@ -26,6 +26,7 @@
#include <net/if.h>
#include <stdio.h>
#include <sys/socket.h>
+#include <sys/utsname.h>
// TODO: use unique_fd.
#define BPF_FD_JUST_USE_INT
@@ -158,6 +159,37 @@
return rv;
}
+// -----------------------------------------------------------------------------
+// TODO - just use BpfUtils.h once that is available in sc-mainline-prod and has kernelVersion()
+//
+// In the mean time copying verbatim from:
+// system/bpf/libbpf_android/include/bpf/BpfUtils.h
+// and
+// system/bpf/libbpf_android/BpfUtils.cpp
+
+#define KVER(a, b, c) (((a) << 24) + ((b) << 16) + (c))
+
+static unsigned kernelVersion() {
+ struct utsname buf;
+ int ret = uname(&buf);
+ if (ret) return 0;
+
+ unsigned kver_major;
+ unsigned kver_minor;
+ unsigned kver_sub;
+ char discard;
+ ret = sscanf(buf.release, "%u.%u.%u%c", &kver_major, &kver_minor, &kver_sub, &discard);
+ // Check the device kernel version
+ if (ret < 3) return 0;
+
+ return KVER(kver_major, kver_minor, kver_sub);
+}
+
+static inline bool isAtLeastKernelVersion(unsigned major, unsigned minor, unsigned sub) {
+ return kernelVersion() >= KVER(major, minor, sub);
+}
+// -----------------------------------------------------------------------------
+
static jboolean com_android_networkstack_tethering_BpfUtils_isEthernet(JNIEnv* env, jobject clazz,
jstring iface) {
ScopedUtfChars interface(env, iface);
@@ -170,13 +202,30 @@
return false;
}
+ // Backwards compatibility with pre-GKI kernels that use various custom
+ // ARPHRD_* for their cellular interface
+ switch (rv) {
+ // ARPHRD_PUREIP on at least some Mediatek Android kernels
+ // example: wembley with 4.19 kernel
+ case 520:
+ // in Linux 4.14+ rmnet support was upstreamed and ARHRD_RAWIP became 519,
+ // but it is 530 on at least some Qualcomm Android 4.9 kernels with rmnet
+ // example: Pixel 3 family
+ case 530:
+ // >5.4 kernels are GKI2.0 and thus upstream compatible, however 5.10
+ // shipped with Android S, so (for safety) let's limit ourselves to
+ // >5.10, ie. 5.11+ as a guarantee we're on Android T+ and thus no
+ // longer need this non-upstream compatibility logic
+ static bool is_pre_5_11_kernel = !isAtLeastKernelVersion(5, 11, 0);
+ if (is_pre_5_11_kernel) return false;
+ }
+
switch (rv) {
case ARPHRD_ETHER:
return true;
case ARPHRD_NONE:
case ARPHRD_PPP:
- case ARPHRD_RAWIP: // in Linux 4.14+ rmnet support was upstreamed and this is 519
- case 530: // this is ARPHRD_RAWIP on some Android 4.9 kernels with rmnet
+ case ARPHRD_RAWIP:
return false;
default:
jniThrowExceptionFmt(env, "java/io/IOException",