diff options
Diffstat (limited to 'libnativebridge/native_bridge.cc')
-rw-r--r-- | libnativebridge/native_bridge.cc | 101 |
1 files changed, 94 insertions, 7 deletions
diff --git a/libnativebridge/native_bridge.cc b/libnativebridge/native_bridge.cc index ad4ee73..2205f45 100644 --- a/libnativebridge/native_bridge.cc +++ b/libnativebridge/native_bridge.cc @@ -16,6 +16,7 @@ #include "nativebridge/native_bridge.h" +#include <cutils/log.h> #include <dlfcn.h> #include <stdio.h> #include "utils/Mutex.h" @@ -28,27 +29,92 @@ static Mutex native_bridge_lock("native bridge lock"); // The symbol name exposed by native-bridge with the type of NativeBridgeCallbacks. static constexpr const char* kNativeBridgeInterfaceSymbol = "NativeBridgeItf"; -// The path of the library we are supposed to load. -static const char* native_bridge_library_path = nullptr; +// The filename of the library we are supposed to load. +static const char* native_bridge_library_filename = nullptr; // Whether a native bridge is available (loaded and ready). static bool available = false; // Whether we have already initialized (or tried to). static bool initialized = false; +// Whether we had an error at some point. +static bool had_error = false; static NativeBridgeCallbacks* callbacks = nullptr; static const NativeBridgeRuntimeCallbacks* runtime_callbacks = nullptr; -void SetupNativeBridge(const char* nb_library_path, +// Characters allowed in a native bridge filename. The first character must +// be in [a-zA-Z] (expected 'l' for "libx"). The rest must be in [a-zA-Z0-9._-]. +static bool CharacterAllowed(char c, bool first) { + if (first) { + return ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'); + } else { + return ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z') || ('0' <= c && c <= '9') || + (c == '.') || (c == '_') || (c == '-'); + } +} + +// We only allow simple names for the library. It is supposed to be a file in +// /system/lib or /vendor/lib. Only allow a small range of characters, that is +// names consisting of [a-zA-Z0-9._-] and starting with [a-zA-Z]. +bool NativeBridgeNameAcceptable(const char* nb_library_filename) { + const char* ptr = nb_library_filename; + if (*ptr == 0) { + // Emptry string. Allowed, means no native bridge. + return true; + } else { + // First character must be [a-zA-Z]. + if (!CharacterAllowed(*ptr, true)) { + // Found an invalid fist character, don't accept. + ALOGE("Native bridge library %s has been rejected for first character %c", nb_library_filename, *ptr); + return false; + } else { + // For the rest, be more liberal. + ptr++; + while (*ptr != 0) { + if (!CharacterAllowed(*ptr, false)) { + // Found an invalid character, don't accept. + ALOGE("Native bridge library %s has been rejected for %c", nb_library_filename, *ptr); + return false; + } + ptr++; + } + } + return true; + } +} + +void SetupNativeBridge(const char* nb_library_filename, const NativeBridgeRuntimeCallbacks* runtime_cbs) { Mutex::Autolock auto_lock(native_bridge_lock); - native_bridge_library_path = nb_library_path; + if (initialized || native_bridge_library_filename != nullptr) { + // Setup has been called before. Ignore this call. + ALOGW("Called SetupNativeBridge for an already set up native bridge."); + // Note: counts as an error, even though the bridge may be functional. + had_error = true; + return; + } + runtime_callbacks = runtime_cbs; - if (native_bridge_library_path == nullptr) { - initialized = true; + if (nb_library_filename == nullptr) { available = false; + initialized = true; + } else { + // Check whether it's an empty string. + if (*nb_library_filename == 0) { + available = false; + initialized = true; + } else if (!NativeBridgeNameAcceptable(nb_library_filename)) { + available = false; + initialized = true; + had_error = true; + } + + if (!initialized) { + // Didn't find a name error or empty string, assign it. + native_bridge_library_filename = nb_library_filename; + } } } @@ -62,7 +128,15 @@ static bool NativeBridgeInitialize() { available = false; - void* handle = dlopen(native_bridge_library_path, RTLD_LAZY); + if (native_bridge_library_filename == nullptr) { + // Called initialize without setup. dlopen has special semantics for nullptr input. + // So just call it a day here. This counts as an error. + initialized = true; + had_error = true; + return false; + } + + void* handle = dlopen(native_bridge_library_filename, RTLD_LAZY); if (handle != nullptr) { callbacks = reinterpret_cast<NativeBridgeCallbacks*>(dlsym(handle, kNativeBridgeInterfaceSymbol)); @@ -72,8 +146,13 @@ static bool NativeBridgeInitialize() { } if (!available) { + // If we fail initialization, this counts as an error. + had_error = true; dlclose(handle); } + } else { + // Being unable to open the library counts as an error. + had_error = true; } initialized = true; @@ -81,6 +160,14 @@ static bool NativeBridgeInitialize() { return available; } +bool NativeBridgeError() { + return had_error; +} + +bool NativeBridgeAvailable() { + return NativeBridgeInitialize(); +} + void* NativeBridgeLoadLibrary(const char* libpath, int flag) { if (NativeBridgeInitialize()) { return callbacks->loadLibrary(libpath, flag); |