Merge "Support loading shared libraries from zip files"

4 files changed, 149 insertions, 18 deletions

diff --git a/linker/Android.mk b/linker/Android.mk
index f78a025..81c007f 100644
--- a/linker/Android.mk
+++ b/linker/Android.mk
@@ -57,7 +57,7 @@ LOCAL_ASFLAGS := $(LOCAL_CFLAGS)
 
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 
-LOCAL_STATIC_LIBRARIES := libc_nomalloc
+LOCAL_STATIC_LIBRARIES := libc_nomalloc libziparchive libutils libz liblog
 
 LOCAL_FORCE_STATIC_EXECUTABLE := true
 
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 18f8cdc..15ea423 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -57,6 +57,7 @@
 #include "linker_phdr.h"
 #include "linker_relocs.h"
 #include "linker_reloc_iterators.h"
+#include "ziparchive/zip_archive.h"
 
 /* >>> IMPORTANT NOTE - READ ME BEFORE MODIFYING <<<
  *
@@ -838,29 +839,109 @@ ElfW(Sym)* soinfo::elf_addr_lookup(const void* addr) {
   return nullptr;
 }
 
-static int open_library_on_path(const char* name, const char* const paths[]) {
+static int open_library_in_zipfile(const char* const path,
+                                   off64_t* file_offset) {
+  TRACE("Trying zip file open from path '%s'", path);
+
+  // Treat an '!' character inside a path as the separator between the name
+  // of the zip file on disk and the subdirectory to search within it.
+  // For example, if path is "foo.zip!bar/bas/x.so", then we search for
+  // "bar/bas/x.so" within "foo.zip".
+  const char* separator = strchr(path, '!');
+  if (separator == nullptr) {
+    return -1;
+  }
+
+  char buf[512];
+  if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf)) {
+    PRINT("Warning: ignoring very long library path: %s", path);
+    return -1;
+  }
+
+  buf[separator - path] = '\0';
+
+  const char* zip_path = buf;
+  const char* file_path = &buf[separator - path + 1];
+  int fd = TEMP_FAILURE_RETRY(open(zip_path, O_RDONLY | O_CLOEXEC));
+  if (fd == -1) {
+    return -1;
+  }
+
+  ZipArchiveHandle handle;
+  if (OpenArchiveFd(fd, "", &handle, false) != 0) {
+    // invalid zip-file (?)
+    close(fd);
+    return -1;
+  }
+
+  auto archive_guard = make_scope_guard([&]() {
+    CloseArchive(handle);
+  });
+
+  ZipEntry entry;
+
+  if (FindEntry(handle, ZipEntryName(file_path), &entry) != 0) {
+    // Entry was not found.
+    close(fd);
+    return -1;
+  }
+
+  // Check if it is properly stored
+  if (entry.method != kCompressStored || (entry.offset % PAGE_SIZE) != 0) {
+    close(fd);
+    return -1;
+  }
+
+  *file_offset = entry.offset;
+  return fd;
+}
+
+static int open_library_on_path(const char* name,
+                                const char* const paths[],
+                                off64_t* file_offset) {
   char buf[512];
-  for (size_t i = 0; paths[i] != nullptr; ++i) {
-    int n = __libc_format_buffer(buf, sizeof(buf), "%s/%s", paths[i], name);
+  int fd = -1;
+
+  for (size_t i = 0; paths[i] != nullptr && fd == -1; ++i) {
+    const char* const path = paths[i];
+    int n = __libc_format_buffer(buf, sizeof(buf), "%s/%s", path, name);
     if (n < 0 || n >= static_cast<int>(sizeof(buf))) {
-      PRINT("Warning: ignoring very long library path: %s/%s", paths[i], name);
-      continue;
+      PRINT("Warning: ignoring very long library path: %s/%s", path, name);
+      return -1;
     }
-    int fd = TEMP_FAILURE_RETRY(open(buf, O_RDONLY | O_CLOEXEC));
-    if (fd != -1) {
-      return fd;
+
+    const char* separator = strchr(path, '!');
+
+    if (separator != nullptr) {
+      fd = open_library_in_zipfile(buf, file_offset);
+    }
+
+    if (fd == -1) {
+      fd = TEMP_FAILURE_RETRY(open(buf, O_RDONLY | O_CLOEXEC));
+      if (fd != -1) {
+        *file_offset = 0;
+      }
     }
   }
-  return -1;
+
+  return fd;
 }
 
-static int open_library(const char* name) {
+static int open_library(const char* name, off64_t* file_offset) {
   TRACE("[ opening %s ]", name);
 
   // If the name contains a slash, we should attempt to open it directly and not search the paths.
   if (strchr(name, '/') != nullptr) {
+    if (strchr(name, '!') != nullptr) {
+      int fd = open_library_in_zipfile(name, file_offset);
+      if (fd != -1) {
+        return fd;
+      }
+    }
+
     int fd = TEMP_FAILURE_RETRY(open(name, O_RDONLY | O_CLOEXEC));
     if (fd != -1) {
+      *file_offset = 0;
       return fd;
     }
     // ...but nvidia binary blobs (at least) rely on this behavior, so fall through for now.
@@ -870,9 +951,9 @@ static int open_library(const char* name) {
   }
 
   // Otherwise we try LD_LIBRARY_PATH first, and fall back to the built-in well known paths.
-  int fd = open_library_on_path(name, g_ld_library_paths);
+  int fd = open_library_on_path(name, g_ld_library_paths, file_offset);
   if (fd == -1) {
-    fd = open_library_on_path(name, kDefaultLdPaths);
+    fd = open_library_on_path(name, kDefaultLdPaths, file_offset);
   }
   return fd;
 }
@@ -886,7 +967,9 @@ static void for_each_dt_needed(const soinfo* si, F action) {
   }
 }
 
-static soinfo* load_library(LoadTaskList& load_tasks, const char* name, int rtld_flags, const android_dlextinfo* extinfo) {
+static soinfo* load_library(LoadTaskList& load_tasks,
+                            const char* name, int rtld_flags,
+                            const android_dlextinfo* extinfo) {
   int fd = -1;
   off64_t file_offset = 0;
   ScopedFd file_guard(-1);
@@ -898,7 +981,7 @@ static soinfo* load_library(LoadTaskList& load_tasks, const char* name, int rtld
     }
   } else {
     // Open the file.
-    fd = open_library(name);
+    fd = open_library(name, &file_offset);
     if (fd == -1) {
       DL_ERR("library \"%s\" not found", name);
       return nullptr;
diff --git a/tests/dlfcn_test.cpp b/tests/dlfcn_test.cpp
index dfb5e54..ef4ff20 100644
--- a/tests/dlfcn_test.cpp
+++ b/tests/dlfcn_test.cpp
@@ -29,6 +29,14 @@
 #define ASSERT_SUBSTR(needle, haystack) \
     ASSERT_PRED_FORMAT2(::testing::IsSubstring, needle, haystack)
 
+#if defined(__LP64__)
+#define LIBPATH_PREFIX "/nativetest64/libdlext_test_fd/"
+#else
+#define LIBPATH_PREFIX "/nativetest/libdlext_test_fd/"
+#endif
+
+#define LIBZIPPATH LIBPATH_PREFIX "libdlext_test_fd_zipaligned.zip"
+
 static bool g_called = false;
 extern "C" void DlSymTestFunction() {
   g_called = true;
@@ -844,6 +852,46 @@ TEST(dlfcn, dlopen_symlink) {
   dlclose(handle2);
 }
 
+TEST(dlfcn, dlopen_from_zip_absolute_path) {
+  const std::string lib_path = std::string(getenv("ANDROID_DATA")) + LIBZIPPATH;
+
+  void* handle = dlopen((lib_path + "!libdir/libdlext_test_fd.so").c_str(), RTLD_NOW);
+  ASSERT_TRUE(handle != nullptr) << dlerror();
+
+  int (*fn)(void);
+  fn = reinterpret_cast<int (*)(void)>(dlsym(handle, "getRandomNumber"));
+  ASSERT_TRUE(fn != nullptr);
+  EXPECT_EQ(4, fn());
+
+  dlclose(handle);
+}
+
+TEST(dlfcn, dlopen_from_zip_ld_library_path) {
+  const std::string lib_path = std::string(getenv("ANDROID_DATA")) + LIBZIPPATH + "!libdir";
+
+  typedef void (*fn_t)(const char*);
+  fn_t android_update_LD_LIBRARY_PATH =
+      reinterpret_cast<fn_t>(dlsym(RTLD_DEFAULT, "android_update_LD_LIBRARY_PATH"));
+
+  ASSERT_TRUE(android_update_LD_LIBRARY_PATH != nullptr) << dlerror();
+
+  void* handle = dlopen("libdlext_test_fd.so", RTLD_NOW);
+  ASSERT_TRUE(handle == nullptr);
+
+  android_update_LD_LIBRARY_PATH(lib_path.c_str());
+
+  handle = dlopen("libdlext_test_fd.so", RTLD_NOW);
+  ASSERT_TRUE(handle != nullptr) << dlerror();
+
+  int (*fn)(void);
+  fn = reinterpret_cast<int (*)(void)>(dlsym(handle, "getRandomNumber"));
+  ASSERT_TRUE(fn != nullptr);
+  EXPECT_EQ(4, fn());
+
+  dlclose(handle);
+}
+
+
 // libtest_dlopen_from_ctor_main.so depends on
 // libtest_dlopen_from_ctor.so which has a constructor
 // that calls dlopen(libc...). This is to test the situation
diff --git a/tests/libs/Android.build.dlext_testzip.mk b/tests/libs/Android.build.dlext_testzip.mk
index d05927e..7cc0dae 100644
--- a/tests/libs/Android.build.dlext_testzip.mk
+++ b/tests/libs/Android.build.dlext_testzip.mk
@@ -35,7 +35,7 @@ my_shared_libs := \
 $(LOCAL_BUILT_MODULE): PRIVATE_ALIGNMENT := 4096 # PAGE_SIZE
 $(LOCAL_BUILT_MODULE) : $(my_shared_libs) | $(ZIPALIGN)
 	@echo "Zipalign $(PRIVATE_ALIGNMENT): $@"
-	$(hide) rm -rf $(dir $@) && mkdir -p $(dir $@)
-	$(hide) cp $^ $(dir $@)
-	$(hide) (cd $(dir $@) && touch empty_file.txt && zip -rD0 $(notdir $@).unaligned empty_file.txt *.so)
+	$(hide) rm -rf $(dir $@) && mkdir -p $(dir $@)/libdir
+	$(hide) cp $^ $(dir $@)/libdir
+	$(hide) (cd $(dir $@) && touch empty_file.txt && zip -rD0 $(notdir $@).unaligned empty_file.txt libdir/*.so)
 	$(hide) $(ZIPALIGN) $(PRIVATE_ALIGNMENT) $@.unaligned $@