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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
#include "AndroidNetworkBlockedReason.h"
#include <dlfcn.h>
#include <cstdint>
#include "mozilla/Maybe.h"
#include "private/pprio.h"
namespace mozilla::net {
// ANDROID_NETWORK_BLOCKED_REASON_LNP from <android/multinetwork.h>. The NDK
// doesn't declare this constant yet, so we hardcode the value Chromium
// hardcodes in net::android::NetworkBlockedReason::kLnp
// (net/android/network_library.h), which carries the same caveat.
static const int32_t kAndroidNetworkBlockedReasonLNP = 1;
bool IsAndroidNetworkBlockedReasonLNP(int32_t aBlockedReason) {
return aBlockedReason == kAndroidNetworkBlockedReasonLNP;
}
namespace {
using AndroidGetNetworkBlockedReasonFn = int32_t (*)(int);
// android_getnetworkblockedreason() lives in libandroid.so, not libc.so, and
// (like IsAndroidNetworkBlockedReasonLNP's constant) isn't declared by the
// NDK yet, so it must be dlsym-resolved rather than called directly. Devices
// older than Android 16 won't have the symbol at all. See
// ("For TCP connections, browsers should use the NDK API
// android_getnetworkblockedreason(int sockFd)...").
AndroidGetNetworkBlockedReasonFn GetAndroidGetNetworkBlockedReasonFn() {
void* handle = dlopen("libandroid.so", RTLD_NOW);
if (!handle) {
return nullptr;
}
return reinterpret_cast<AndroidGetNetworkBlockedReasonFn>(
dlsym(handle, "android_getnetworkblockedreason"));
}
// Returns Nothing() if the device doesn't expose the API, or |fd|'s native
// handle can't be extracted.
Maybe<int32_t> QueryAndroidNetworkBlockedReason(PRFileDesc* fd) {
static AndroidGetNetworkBlockedReasonFn sGetNetworkBlockedReason =
GetAndroidGetNetworkBlockedReasonFn();
if (!sGetNetworkBlockedReason) {
return Nothing();
}
PRFileDesc* bottom = PR_GetIdentitiesLayer(fd, PR_NSPR_IO_LAYER);
if (!bottom) {
return Nothing();
}
int nativeFd = PR_FileDesc2NativeHandle(bottom);
if (nativeFd < 0) {
return Nothing();
}
return Some(sGetNetworkBlockedReason(nativeFd));
}
} // namespace
bool IsConnectBlockedByAndroidLocalNetworkPermission(PRFileDesc* fd) {
Maybe<int32_t> reason = QueryAndroidNetworkBlockedReason(fd);
return reason && IsAndroidNetworkBlockedReasonLNP(*reason);
}
} // namespace mozilla::net