init: create sockets before forking
There is a race condition with Service::Start and socket creation.
Since socket creation currently happens after the fork(), it's
possible that init can continue executing other commands before the
socket is created. If init starts another service that relies on that
socket, it isn't guaranteed to be available.
Particularly, we've seen this with hwservicemanager starting after
logd, but hwservicemanager's logs sometimes not showing up.
Bug: 140810300
Test: boot and logging functions correctly
Change-Id: Ib2932e836d345830cd38f3b556598508fd953058
diff --git a/init/service_utils.cpp b/init/service_utils.cpp
index 836145d..35f2acf 100644
--- a/init/service_utils.cpp
+++ b/init/service_utils.cpp
@@ -26,7 +26,6 @@
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
-#include <android-base/unique_fd.h>
#include <cutils/android_get_control_file.h>
#include <cutils/sockets.h>
#include <processgroup/processgroup.h>
@@ -138,37 +137,44 @@
dup2(fd, 2);
}
-void PublishDescriptor(const std::string& key, const std::string& name, int fd) {
- std::string published_name = key + name;
+} // namespace
+
+void Descriptor::Publish() const {
+ auto published_name = name_;
+
for (auto& c : published_name) {
c = isalnum(c) ? c : '_';
}
+ int fd = fd_.get();
+ // For safety, the FD is created as CLOEXEC, so that must be removed before publishing.
+ auto fd_flags = fcntl(fd, F_GETFD);
+ fd_flags &= ~FD_CLOEXEC;
+ if (fcntl(fd, F_SETFD, fd_flags) != 0) {
+ PLOG(ERROR) << "Failed to remove CLOEXEC from '" << published_name << "'";
+ }
+
std::string val = std::to_string(fd);
setenv(published_name.c_str(), val.c_str(), 1);
}
-} // namespace
-
-Result<void> SocketDescriptor::CreateAndPublish(const std::string& global_context) const {
+Result<Descriptor> SocketDescriptor::Create(const std::string& global_context) const {
const auto& socket_context = context.empty() ? global_context : context;
- auto result = CreateSocket(name, type, passcred, perm, uid, gid, socket_context);
+ auto result = CreateSocket(name, type | SOCK_CLOEXEC, passcred, perm, uid, gid, socket_context);
if (!result) {
return result.error();
}
- PublishDescriptor(ANDROID_SOCKET_ENV_PREFIX, name, *result);
-
- return {};
+ return Descriptor(ANDROID_SOCKET_ENV_PREFIX + name, unique_fd(*result));
}
-Result<void> FileDescriptor::CreateAndPublish() const {
+Result<Descriptor> FileDescriptor::Create() const {
int flags = (type == "r") ? O_RDONLY : (type == "w") ? O_WRONLY : O_RDWR;
// Make sure we do not block on open (eg: devices can chose to block on carrier detect). Our
// intention is never to delay launch of a service for such a condition. The service can
// perform its own blocking on carrier detect.
- android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(name.c_str(), flags | O_NONBLOCK)));
+ unique_fd fd(TEMP_FAILURE_RETRY(open(name.c_str(), flags | O_NONBLOCK | O_CLOEXEC)));
if (fd < 0) {
return ErrnoError() << "Failed to open file '" << name << "'";
@@ -179,9 +185,7 @@
LOG(INFO) << "Opened file '" << name << "', flags " << flags;
- PublishDescriptor(ANDROID_FILE_ENV_PREFIX, name, fd.release());
-
- return {};
+ return Descriptor(ANDROID_FILE_ENV_PREFIX + name, std::move(fd));
}
Result<void> EnterNamespaces(const NamespaceInfo& info, const std::string& name, bool pre_apexd) {