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mac: ChildPortHandshake: allow receive rights to be sent

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The intended use is to flip the client-server relationship in
CrashpadClient so that the initial client (parent process) furnishes the
handler process with a receive right. The parent can optionally receive
a port-destroyed notification allowing it to restart the handler if it
exits prematurely.

R=rsesek@chromium.org

Review URL: https://codereview.chromium.org/1408473002 .
This commit is contained in:
Mark Mentovai 2015-10-29 14:14:15 -04:00
parent 3ee9d891d9
commit 062138106c
10 changed files with 812 additions and 306 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
client/crashpad_client_mac.cc
View File

@ -97,7 +97,7 @@ bool CrashpadClient::StartHandler(
// Set up the arguments for execve() first. These aren’t needed until execve()
// is called, but it’s dangerous to do this in a child process after fork().
ChildPortHandshake child_port_handshake;
int handshake_fd = child_port_handshake.ReadPipeFD();
base::ScopedFD client_read_fd = child_port_handshake.ClientReadFD();
// Use handler as argv[0], followed by arguments directed by this method’s
// parameters and a --handshake-fd argument. |arguments| are added first so
@ -119,7 +119,7 @@ bool CrashpadClient::StartHandler(
argv.push_back(
FormatArgumentString("annotation", kv.first + '=' + kv.second));
}
argv.push_back(FormatArgumentInt("handshake-fd", handshake_fd));
argv.push_back(FormatArgumentInt("handshake-fd", client_read_fd.get()));
// argv_c contains const char* pointers and is terminated by nullptr. argv
// is required because the pointers in argv_c need to point somewhere, and
@ -181,7 +181,7 @@ bool CrashpadClient::StartHandler(
// Grandchild process.
CloseMultipleNowOrOnExec(STDERR_FILENO + 1, handshake_fd);
CloseMultipleNowOrOnExec(STDERR_FILENO + 1, client_read_fd.get());
// &argv_c[0] is a pointer to a pointer to const char data, but because of
// how C (not C++) works, execvp() wants a pointer to a const pointer to
@ -193,6 +193,8 @@ bool CrashpadClient::StartHandler(
// Parent process.
client_read_fd.reset();
// waitpid() for the child, so that it does not become a zombie process. The
// child normally exits quickly.
int status;
@ -209,7 +211,8 @@ bool CrashpadClient::StartHandler(
}
// Rendezvous with the handler running in the grandchild process.
exception_port_.reset(child_port_handshake.RunServer());
exception_port_.reset(child_port_handshake.RunServer(
ChildPortHandshake::PortRightType::kSendRight));
return exception_port_.is_valid();
}

10
handler/main.cc
View File

@ -19,6 +19,7 @@
#include <string>
#include "base/files/file_path.h"
#include "base/files/scoped_file.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "build/build_config.h"
@ -219,9 +220,12 @@ int HandlerMain(int argc, char* argv[]) {
#if defined(OS_MACOSX)
CloseStdinAndStdout();
ChildPortHandshake::RunClient(options.handshake_fd,
exception_handler_server.receive_port(),
MACH_MSG_TYPE_MAKE_SEND);
if (!ChildPortHandshake::RunClientForFD(
base::ScopedFD(options.handshake_fd),
exception_handler_server.receive_port(),
MACH_MSG_TYPE_MAKE_SEND)) {
return EXIT_FAILURE;
}
#endif // OS_MACOSX
scoped_ptr<CrashReportDatabase> database(CrashReportDatabase::Initialize(

12
util/mach/child_port.defs
View File

@ -16,10 +16,10 @@
#include <mach/std_types.defs>
// child_port provides an interface for port rights to be transferred between
// tasks. Its expected usage is for child processes to be able to pass port
// rights to their parent processes. A child may wish to give its parent a copy
// of a send right to its own task port, or a child may hold a receive right for
// a server and wish to furnish its parent with a send right to that server.
// tasks. Its expected usage is for processes to be able to pass port rights
// across IPC boundaries. A child process may wish to give its parent a copy of
// of a send right to its own task port, or a parent process may wish to give a
// receive right to a child process that implements a server.
//
// This Mach subsystem defines the lowest-level interface for these rights to
// be transferred. Most users will not user this interface directly, but will
@ -48,9 +48,7 @@ import "util/mach/child_port_types.h";
// secret allowing the server to verify that it has received a request from
// the intended client. |server| will reject requests with an invalid
// |token|.
// port[in]: A port right to transfer to the server. In expected usage, this may
// be a send or send-once right, and the |server| will reject a receive
// right. It is permissible to specify make-send for a receive right.
// port[in]: A port right to transfer to the server.
//
// Return value: As this is a “simpleroutine”, the server does not respond to
// the client request, and the client does not block waiting for a response

256
util/mach/child_port_handshake.cc
View File

@ -32,60 +32,60 @@
#include "base/strings/stringprintf.h"
#include "util/file/file_io.h"
#include "util/mach/child_port.h"
#include "util/mach/child_port_server.h"
#include "util/mach/mach_extensions.h"
#include "util/mach/mach_message.h"
#include "util/mach/mach_message_server.h"
#include "util/misc/implicit_cast.h"
namespace crashpad {
namespace {
ChildPortHandshake::ChildPortHandshake()
class ChildPortHandshakeServer final : public ChildPortServer::Interface {
public:
ChildPortHandshakeServer();
~ChildPortHandshakeServer();
mach_port_t RunServer(base::ScopedFD server_write_fd,
ChildPortHandshake::PortRightType port_right_type);
private:
// ChildPortServer::Interface:
kern_return_t HandleChildPortCheckIn(child_port_server_t server,
child_port_token_t token,
mach_port_t port,
mach_msg_type_name_t right_type,
const mach_msg_trailer_t* trailer,
bool* destroy_request) override;
child_port_token_t token_;
mach_port_t port_;
mach_msg_type_name_t right_type_;
bool checked_in_;
DISALLOW_COPY_AND_ASSIGN(ChildPortHandshakeServer);
};
ChildPortHandshakeServer::ChildPortHandshakeServer()
: token_(0),
pipe_read_(),
pipe_write_(),
child_port_(MACH_PORT_NULL),
port_(MACH_PORT_NULL),
right_type_(MACH_MSG_TYPE_PORT_NONE),
checked_in_(false) {
// Use socketpair() instead of pipe(). There is no way to suppress SIGPIPE on
// pipes in Mac OS X 10.6, because the F_SETNOSIGPIPE fcntl() command was not
// introduced until 10.7.
int pipe_fds[2];
PCHECK(socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fds) == 0)
<< "socketpair";
pipe_read_.reset(pipe_fds[0]);
pipe_write_.reset(pipe_fds[1]);
// Simulate pipe() semantics by shutting down the “wrong” sides of the socket.
PCHECK(shutdown(pipe_write_.get(), SHUT_RD) == 0) << "shutdown";
PCHECK(shutdown(pipe_read_.get(), SHUT_WR) == 0) << "shutdown";
// SIGPIPE is undesirable when writing to this pipe. Allow broken-pipe writes
// to fail with EPIPE instead.
const int value = 1;
PCHECK(setsockopt(
pipe_write_.get(), SOL_SOCKET, SO_NOSIGPIPE, &value, sizeof(value)) == 0)
<< "setsockopt";
}
ChildPortHandshake::~ChildPortHandshake() {
ChildPortHandshakeServer::~ChildPortHandshakeServer() {
}
int ChildPortHandshake::ReadPipeFD() const {
DCHECK_NE(pipe_read_.get(), -1);
return pipe_read_.get();
}
mach_port_t ChildPortHandshake::RunServer() {
DCHECK_NE(pipe_read_.get(), -1);
pipe_read_.reset();
// Transfer ownership of the write pipe into this method’s scope.
base::ScopedFD pipe_write_owner = pipe_write_.Pass();
mach_port_t ChildPortHandshakeServer::RunServer(
base::ScopedFD server_write_fd,
ChildPortHandshake::PortRightType port_right_type) {
DCHECK_EQ(port_, kMachPortNull);
DCHECK(!checked_in_);
DCHECK(server_write_fd.is_valid());
// Initialize the token and share it with the client via the pipe.
token_ = base::RandUint64();
int pipe_write = pipe_write_owner.get();
if (!LoggingWriteFile(pipe_write, &token_, sizeof(token_))) {
if (!LoggingWriteFile(server_write_fd.get(), &token_, sizeof(token_))) {
LOG(WARNING) << "no client check-in";
return MACH_PORT_NULL;
}
@ -109,14 +109,15 @@ mach_port_t ChildPortHandshake::RunServer() {
// Share the service name with the client via the pipe.
uint32_t service_name_length = service_name.size();
if (!LoggingWriteFile(
pipe_write, &service_name_length, sizeof(service_name_length))) {
if (!LoggingWriteFile(server_write_fd.get(),
&service_name_length,
sizeof(service_name_length))) {
LOG(WARNING) << "no client check-in";
return MACH_PORT_NULL;
}
if (!LoggingWriteFile(
pipe_write, service_name.c_str(), service_name_length)) {
server_write_fd.get(), service_name.c_str(), service_name_length)) {
LOG(WARNING) << "no client check-in";
return MACH_PORT_NULL;
}
@ -147,7 +148,7 @@ mach_port_t ChildPortHandshake::RunServer() {
0,
nullptr);
EV_SET(&changelist[1],
pipe_write,
server_write_fd.get(),
EVFILT_WRITE,
EV_ADD | EV_CLEAR,
0,
@ -162,7 +163,7 @@ mach_port_t ChildPortHandshake::RunServer() {
bool blocking = true;
DCHECK(!checked_in_);
while (!checked_in_) {
DCHECK_EQ(child_port_, kMachPortNull);
DCHECK_EQ(port_, kMachPortNull);
// Get a kevent from the kqueue. Block while waiting for an event unless the
// write pipe has arrived at EOF, in which case the kevent() should be
@ -230,7 +231,7 @@ mach_port_t ChildPortHandshake::RunServer() {
// pipe. Ignore that case. Multiple notifications for that situation
// will not be generated because edge triggering (EV_CLEAR) is used
// above.
DCHECK_EQ(implicit_cast<int>(event.ident), pipe_write);
DCHECK_EQ(implicit_cast<int>(event.ident), server_write_fd.get());
if (event.flags & EV_EOF) {
// There are no readers attached to the write pipe. The client has
// closed its side of the pipe. There can be one last shot at
@ -246,19 +247,48 @@ mach_port_t ChildPortHandshake::RunServer() {
}
}
mach_port_t child_port = MACH_PORT_NULL;
std::swap(child_port_, child_port);
return child_port;
if (port_ == MACH_PORT_NULL) {
return MACH_PORT_NULL;
}
bool mismatch = false;
switch (port_right_type) {
case ChildPortHandshake::PortRightType::kReceiveRight:
if (right_type_ != MACH_MSG_TYPE_PORT_RECEIVE) {
LOG(ERROR) << "expected receive right, observed " << right_type_;
mismatch = true;
}
break;
case ChildPortHandshake::PortRightType::kSendRight:
if (right_type_ != MACH_MSG_TYPE_PORT_SEND &&
right_type_ != MACH_MSG_TYPE_PORT_SEND_ONCE) {
LOG(ERROR) << "expected send or send-once right, observed "
<< right_type_;
mismatch = true;
}
break;
}
if (mismatch) {
MachMessageDestroyReceivedPort(port_, right_type_);
port_ = MACH_PORT_NULL;
return MACH_PORT_NULL;
}
mach_port_t port = MACH_PORT_NULL;
std::swap(port_, port);
return port;
}
kern_return_t ChildPortHandshake::HandleChildPortCheckIn(
kern_return_t ChildPortHandshakeServer::HandleChildPortCheckIn(
child_port_server_t server,
const child_port_token_t token,
mach_port_t port,
mach_msg_type_name_t right_type,
const mach_msg_trailer_t* trailer,
bool* destroy_request) {
DCHECK_EQ(child_port_, kMachPortNull);
DCHECK_EQ(port_, kMachPortNull);
DCHECK(!checked_in_);
if (token != token_) {
// If the token’s not correct, someone’s attempting to spoof the legitimate
@ -268,19 +298,18 @@ kern_return_t ChildPortHandshake::HandleChildPortCheckIn(
} else {
checked_in_ = true;
if (right_type == MACH_MSG_TYPE_PORT_RECEIVE) {
// The message needs to carry a send right or a send-once right. This
// isn’t a strict requirement of the protocol, but users of this class
// expect a send right or a send-once right, both of which can be managed
// by base::mac::ScopedMachSendRight. It is invalid to store a receive
// right in that scoper.
LOG(WARNING) << "ignoring MACH_MSG_TYPE_PORT_RECEIVE";
if (right_type != MACH_MSG_TYPE_PORT_RECEIVE &&
right_type != MACH_MSG_TYPE_PORT_SEND &&
right_type != MACH_MSG_TYPE_PORT_SEND_ONCE) {
// The message needs to carry a receive, send, or send-once right.
LOG(ERROR) << "invalid right type " << right_type;
*destroy_request = true;
} else {
// Communicate the child port back to the RunServer().
// Communicate the child port and right type back to the RunServer().
// *destroy_request is left at false, because RunServer() needs the right
// to remain intact. It gives ownership of the right to its caller.
child_port_ = port;
port_ = port;
right_type_ = right_type;
}
}
@ -288,40 +317,112 @@ kern_return_t ChildPortHandshake::HandleChildPortCheckIn(
return MIG_NO_REPLY;
}
// static
void ChildPortHandshake::RunClient(int pipe_read,
mach_port_t port,
} // namespace
ChildPortHandshake::ChildPortHandshake()
: client_read_fd_(),
server_write_fd_() {
// Use socketpair() instead of pipe(). There is no way to suppress SIGPIPE on
// pipes in Mac OS X 10.6, because the F_SETNOSIGPIPE fcntl() command was not
// introduced until 10.7.
int pipe_fds[2];
PCHECK(socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_fds) == 0)
<< "socketpair";
client_read_fd_.reset(pipe_fds[0]);
server_write_fd_.reset(pipe_fds[1]);
// Simulate pipe() semantics by shutting down the “wrong” sides of the socket.
PCHECK(shutdown(server_write_fd_.get(), SHUT_RD) == 0) << "shutdown SHUT_RD";
PCHECK(shutdown(client_read_fd_.get(), SHUT_WR) == 0) << "shutdown SHUT_WR";
// SIGPIPE is undesirable when writing to this pipe. Allow broken-pipe writes
// to fail with EPIPE instead.
const int value = 1;
PCHECK(setsockopt(server_write_fd_.get(),
SOL_SOCKET,
SO_NOSIGPIPE,
&value,
sizeof(value)) == 0) << "setsockopt";
}
ChildPortHandshake::~ChildPortHandshake() {
}
base::ScopedFD ChildPortHandshake::ClientReadFD() {
DCHECK(client_read_fd_.is_valid());
return client_read_fd_.Pass();
}
base::ScopedFD ChildPortHandshake::ServerWriteFD() {
DCHECK(server_write_fd_.is_valid());
return server_write_fd_.Pass();
}
mach_port_t ChildPortHandshake::RunServer(PortRightType port_right_type) {
client_read_fd_.reset();
return RunServerForFD(server_write_fd_.Pass(), port_right_type);
}
bool ChildPortHandshake::RunClient(mach_port_t port,
mach_msg_type_name_t right_type) {
base::ScopedFD pipe_read_owner(pipe_read);
server_write_fd_.reset();
return RunClientForFD(client_read_fd_.Pass(), port, right_type);
}
// static
mach_port_t ChildPortHandshake::RunServerForFD(base::ScopedFD server_write_fd,
PortRightType port_right_type) {
ChildPortHandshakeServer server;
return server.RunServer(server_write_fd.Pass(), port_right_type);
}
// static
bool ChildPortHandshake::RunClientForFD(base::ScopedFD client_read_fd,
mach_port_t port,
mach_msg_type_name_t right_type) {
DCHECK(client_read_fd.is_valid());
// Read the token and the service name from the read side of the pipe.
child_port_token_t token;
std::string service_name;
RunClientInternal_ReadPipe(pipe_read, &token, &service_name);
if (!RunClientInternal_ReadPipe(
client_read_fd.get(), &token, &service_name)) {
return false;
}
// Look up the server and check in with it by providing the token and port.
RunClientInternal_SendCheckIn(service_name, token, port, right_type);
return RunClientInternal_SendCheckIn(service_name, token, port, right_type);
}
// static
void ChildPortHandshake::RunClientInternal_ReadPipe(int pipe_read,
bool ChildPortHandshake::RunClientInternal_ReadPipe(int client_read_fd,
child_port_token_t* token,
std::string* service_name) {
// Read the token from the pipe.
CheckedReadFile(pipe_read, token, sizeof(*token));
if (!LoggingReadFile(client_read_fd, token, sizeof(*token))) {
return false;
}
// Read the service name from the pipe.
uint32_t service_name_length;
CheckedReadFile(pipe_read, &service_name_length, sizeof(service_name_length));
if (!LoggingReadFile(
client_read_fd, &service_name_length, sizeof(service_name_length))) {
return false;
}
service_name->resize(service_name_length);
if (!service_name->empty()) {
CheckedReadFile(pipe_read, &(*service_name)[0], service_name_length);
if (!service_name->empty() &&
!LoggingReadFile(
client_read_fd, &(*service_name)[0], service_name_length)) {
return false;
}
return true;
}
// static
void ChildPortHandshake::RunClientInternal_SendCheckIn(
bool ChildPortHandshake::RunClientInternal_SendCheckIn(
const std::string& service_name,
child_port_token_t token,
mach_port_t port,
@ -329,12 +430,19 @@ void ChildPortHandshake::RunClientInternal_SendCheckIn(
// Get a send right to the server by looking up the service with the bootstrap
// server by name.
base::mac::ScopedMachSendRight server_port(BootstrapLookUp(service_name));
CHECK(server_port.is_valid());
if (server_port == kMachPortNull) {
return false;
}
// Check in with the server.
kern_return_t kr =
child_port_check_in(server_port.get(), token, port, right_type);
MACH_CHECK(kr == KERN_SUCCESS, kr) << "child_port_check_in";
kern_return_t kr = child_port_check_in(
server_port.get(), token, port, right_type);
if (kr != KERN_SUCCESS) {
MACH_LOG(ERROR, kr) << "child_port_check_in";
return false;
}
return true;
}
} // namespace crashpad

288
util/mach/child_port_handshake.h
View File

@ -21,7 +21,7 @@
#include "base/basictypes.h"
#include "base/files/scoped_file.h"
#include "util/mach/child_port_server.h"
#include "util/mach/child_port_types.h"
namespace crashpad {
@ -31,80 +31,177 @@ class ChildPortHandshakeTest;
} // namespace
} // namespace test
//! \brief Implements a handshake protocol that allows a parent process to
//! obtain a Mach port right from a child process.
//! \brief Implements a handshake protocol that allows processes to exchange
//! port rights.
//!
//! Ordinarily, there is no way for parent and child processes to exchange port
//! rights, outside of the rights that children inherit from their parents.
//! These include task-special ports and exception ports, but all of these have
//! system-defined uses, and cannot reliably be replaced: in a multi-threaded
//! parent, it is impossible to temporarily change one an inheritable port while
//! parent, it is impossible to temporarily change an inheritable port while
//! maintaining a guarantee that another thread will not attempt to use it, and
//! in children, it difficult to guarantee that nothing will attempt to use an
//! inheritable port before it can be replaced with the correct one. This latter
//! concern is becoming increasingly more pronounced as system libraries perform
//! more operations that rely on an inheritable port in module initializers.
//! more operations that rely on an inherited port in module initializers.
//!
//! The protocol implemented by this class involves a server that runs in the
//! parent process. The server is published with the bootstrap server, which the
//! child has access to because the bootstrap port is one of the inherited
//! task-special ports. The parent and child also share a pipe, which the parent
//! can write to and the child can read from. After launching a child process,
//! the parent will write a random token to this pipe, along with the name under
//! which its server has been registered with the bootstrap server. The child
//! can then obtain a send right to this server with `bootstrap_look_up()`, and
//! send a check-in message containing the token value and the port right of its
//! choice by calling `child_port_check_in()`.
//! The protocol implemented by this class involves a server that runs in one
//! process. The server is published with the bootstrap server, which the other
//! process has access to because the bootstrap port is one of the inherited
//! task-special ports. The two processes also share a pipe, which the server
//! can write to and the client can read from. The server will write a random
//! token to this pipe, along with the name under which its service has been
//! registered with the bootstrap server. The client can then obtain a send
//! right to this service with `bootstrap_look_up()`, and send a check-in
//! message containing the token value and the port right of its choice by
//! calling `child_port_check_in()`.
//!
//! The inclusion of the token authenticates the child to its parent. This is
//! The inclusion of the token authenticates the client to the server. This is
//! necessary because the service is published with the bootstrap server, which
//! opens up access to it to more than the child process. Because the token is
//! passed to the child by a shared pipe, it constitutes a shared secret not
//! opens up access to it to more than the intended client. Because the token is
//! passed to the client by a shared pipe, it constitutes a shared secret not
//! known by other processes that may have incidental access to the server. The
//! ChildPortHandshake server considers its randomly-generated token valid until
//! a client checks in with it. This mechanism is used instead of examining the
//! request message’s audit trailer to verify the sender’s process ID because in
//! some process architectures, it may be impossible to verify the child’s
//! process ID. This may happen when the child disassociates from the parent
//! with a double fork(), and the actual client is the parent’s grandchild. In
//! this case, the child would not check in, but the grandchild, in possession
//! of the token, would check in.
//! some process architectures, it may be impossible to verify the client’s
//! process ID.
//!
//! The shared pipe serves another purpose: the server monitors it for an
//! end-of-file (no readers) condition. Once detected, it will stop its blocking
//! wait for a client to check in. This mechanism was chosen over monitoring a
//! child process directly for exit to account for the possibility that the
//! child might disassociate with a double fork().
//! wait for a client to check in. This mechanism was also chosen for its
//! ability to function properly in diverse process architectures.
//!
//! This class can be used to allow a child process to provide its parent with
//! a send right to its task port, in cases where it is desirable for the parent
//! to have such access. It can also be used to allow a child process to
//! establish its own server and provide its parent with a send right to that
//! server, for cases where a service is provided and it is undesirable or
//! impossible to provide it via the bootstrap or launchd interfaces.
class ChildPortHandshake : public ChildPortServer::Interface {
//! This class can be used to allow a child process to provide its parent with a
//! send right to its task port, in cases where it is desirable for the parent
//! to have such access. It can also be used to allow a parent process to
//! transfer a receive right to a child process that implements the server for
//! that right, or for a child process to establish its own server and provide
//! its parent with a send right to that server, for cases where a service is
//! provided and it is undesirable or impossible to provide it via the bootstrap
//! or launchd interfaces.
//!
//! Example parent process, running a client that sends a receive right to its
//! child:
//! \code
//! ChildPortHandshake child_port_handshake;
//! base::ScopedFD server_write_fd = child_port_handshake.ServerWriteFD();
//! std::string server_write_fd_string =
//! base::StringPrintf("%d", server_write_fd);
//!
//! pid_t pid = fork();
//! if (pid == 0) {
//! // Child
//!
//! // Close all file descriptors above STDERR_FILENO except for
//! // server_write_fd. Let the child know what file descriptor to use for
//! // server_write_fd by passing it as argv[1]. Example code for the child
//! // process is below.
//! CloseMultipleNowOrOnExec(STDERR_FILENO + 1, server_write_fd);
//! execlp("child", "child", server_write_fd_string.c_str(), nullptr);
//! }
//!
//! // Parent
//!
//! // Close the child’s end of the pipe.
//! server_write_fd.reset();
//!
//! // Make a new Mach receive right.
//! base::mac::ScopedMachReceiveRight
//! receive_right(NewMachPort(MACH_PORT_RIGHT_RECEIVE));
//!
//! // Make a send right corresponding to the receive right.
//! mach_port_t send_right;
//! mach_msg_type_name_t send_right_type;
//! mach_port_extract_right(mach_task_self(),
//! receive_right.get(),
//! MACH_MSG_TYPE_MAKE_SEND,
//! &send_right,
//! &send_right_type);
//! base::mac::ScopedMachSendRight send_right_owner(send_right);
//!
//! // Send the receive right to the child process, retaining the send right
//! // for use in the parent process.
//! if (child_port_handshake.RunClient(receive_right,
//! MACH_MSG_TYPE_MOVE_RECEIVE)) {
//! ignore_result(receive_right.release());
//! }
//! \endcode
//!
//! Example child process, running a server that receives a receive right from
//! its parent:
//! \code
//! int main(int argc, char* argv[]) {
//! // The parent passed server_write_fd in argv[1].
//! base::ScopedFD server_write_fd(atoi(argv[1]));
//!
//! // Obtain a receive right from the parent process.
//! base::mac::ScopedMachReceiveRight receive_right(
//! ChildPortHandshake::RunServerForFD(
//! server_write_fd.Pass(),
//! ChildPortHandshake::PortRightType::kReceiveRight));
//! }
//! \endcode
class ChildPortHandshake {
public:
//! \brief Initializes the server.
//!
//! This creates the pipe so that the “read” side can be obtained by calling
//! ReadPipeFD().
ChildPortHandshake();
//! \brief Controls whether a receive or send right is expected to be
//! obtained from the client by the server’s call to RunServer().
enum class PortRightType {
//! \brief The server expects to receive a receive right.
kReceiveRight = 0,
//! \brief The server expects to receive a send or send-once right.
kSendRight,
};
ChildPortHandshake();
~ChildPortHandshake();
//! \brief Obtains the “read” side of the pipe, to be used by the client.
//!
//! Callers must obtain this file descriptor and arrange for the caller to
//! have access to it before calling RunServer().
//! This file descriptor must be passed to RunClientForFD().
//!
//! \return The file descriptor that the client should read from.
int ReadPipeFD() const;
base::ScopedFD ClientReadFD();
//! \brief Obtains the “write” side of the pipe, to be used by the server.
//!
//! This file descriptor must be passed to RunServerForFD().
//!
//! \return The file descriptor that the server should write to.
base::ScopedFD ServerWriteFD();
//! \brief Runs the server.
//!
//! This method performs these tasks:
//! - Closes the “read” side of the pipe in-process, so that the client
//! process holds the only file descriptor that can read from the pipe.
//! This method closes the “read” side of the pipe in-process, so that the
//! client process holds the only file descriptor that can read from the pipe.
//! It then calls RunServerForFD() using the “write” side of the pipe. If
//! ClientReadFD() has already been called in the server process, the caller
//! must ensure that the file descriptor returned by ClientReadFD() is closed
//! prior to calling this method.
mach_port_t RunServer(PortRightType port_right_type);
//! \brief Runs the client.
//!
//! This method closes the “write” side of the pipe in-process, so that the
//! server process holds the only file descriptor that can write to the pipe.
//! It then calls RunClientForFD() using the “read” side of the pipe. If
//! ServerWriteFD() has already been called in the client process, the caller
//! must ensure that the file descriptor returned by ServerWriteFD() is closed
//! prior to calling this method.
//!
//! \return `true` on success, `false` on failure with a message logged.
bool RunClient(mach_port_t port, mach_msg_type_name_t right_type);
//! \brief Runs the server.
//!
//! If a ChildPortHandshake object is available, don’t call this static
//! function. Instead, call RunServer(), which wraps this function. When using
//! this function, the caller is responsible for ensuring that the client
//! “read” side of the pipe is closed in the server process prior to calling
//! this function.
//!
//! This function performs these tasks:
//! - Creates a random token and sends it via the pipe.
//! - Checks its service in with the bootstrap server, and sends the name
//! of its bootstrap service mapping via the pipe.
@ -114,33 +211,35 @@ class ChildPortHandshake : public ChildPortServer::Interface {
//! interpret and validate it, and if the message is valid, returns the
//! port right extracted from the message. If the message is not valid,
//! this method will continue waiting for a valid message. Valid messages
//! are properly formatted and have the correct token. If a valid message
//! carries a send or send-once right, it will be returned. If a valid
//! message contains a receive right, it will be destroyed and
//! `MACH_PORT_NULL` will be returned. If a message is not valid, this
//! are properly formatted and have the correct token. The right carried in
//! a valid message will be returned. If a message is not valid, this
//! method will continue waiting for pipe EOF or a valid message.
//! - When notified of pipe EOF, returns `MACH_PORT_NULL`.
//! - Regardless of return value, destroys the server’s receive right and
//! closes the pipe.
//!
//! \return On success, the send or send-once right to the port provided by
//! the client. The caller takes ownership of this right. On failure,
//! `MACH_PORT_NULL`, indicating that the client did not check in properly
//! before terminating, where termination is detected by noticing that the
//! read side of the shared pipe has closed. On failure, a message
//! indiciating the nature of the failure will be logged.
mach_port_t RunServer();
// ChildPortServer::Interface:
kern_return_t HandleChildPortCheckIn(child_port_server_t server,
child_port_token_t token,
mach_port_t port,
mach_msg_type_name_t right_type,
const mach_msg_trailer_t* trailer,
bool* destroy_request) override;
//! \param[in] port_right_type The port right type expected to be received
//! from the client. If the port right received from the client does not
//! match the expected type, the received port right will be destroyed,
//! and `MACH_PORT_NULL` will be returned.
//!
//! \return On success, the port right provided by the client. The caller
//! takes ownership of this right. On failure, `MACH_PORT_NULL`,
//! indicating that the client did not check in properly before
//! terminating, where termination is detected by detecting that the read
//! side of the shared pipe has closed. On failure, a message indicating
//! the nature of the failure will be logged.
static mach_port_t RunServerForFD(base::ScopedFD server_write_fd,
PortRightType port_right_type);
//! \brief Runs the client.
//!
//! If a ChildPortHandshake object is available, don’t call this static
//! function. Instead, call RunClient(), which wraps this function. When using
//! this function, the caller is responsible for ensuring that the server
//! “write” side of the pipe is closed in the client process prior to calling
//! this function.
//!
//! This function performs these tasks:
//! - Reads the token from the pipe.
//! - Reads the bootstrap service name from the pipe.
@ -155,32 +254,42 @@ class ChildPortHandshake : public ChildPortServer::Interface {
//! check-in to occur without blocking to wait for a reply.
//!
//! \param[in] pipe_read The “read” side of the pipe shared with the server
//! process.
//! \param[in] port The port that will be passed to the server by
//! process. This function takes ownership of this file descriptor, and
//! will close it prior to returning.
//! \param[in] port The port right that will be passed to the server by
//! `child_port_check_in()`.
//! \param[in] right_type The right type to furnish the parent with. If \a
//! \param[in] right_type The right type to furnish the server with. If \a
//! port is a send right, this can be `MACH_MSG_TYPE_COPY_SEND` or
//! `MACH_MSG_TYPE_MOVE_SEND`. If \a port is a send-once right, this can
//! be `MACH_MSG_TYPE_MOVE_SEND_ONCE`. If \a port is a receive right,
//! this can be `MACH_MSG_TYPE_MAKE_SEND`. `MACH_MSG_TYPE_MOVE_RECEIVE`
//! is supported by the client interface but will be silently rejected by
//! server run by RunServer(), which expects to receive only send or
//! send-once rights.
static void RunClient(int pipe_read,
mach_port_t port,
mach_msg_type_name_t right_type);
//! be `MACH_MSG_TYPE_MOVE_SEND_ONCE`. If \a port is a receive right, this
//! can be `MACH_MSG_TYPE_MAKE_SEND`, `MACH_MSG_TYPE_MAKE_SEND_ONCE`, or
//! `MACH_MSG_TYPE_MOVE_RECEIVE`.
//!
//! \return `true` on success, `false` on failure with a message logged. On
//! failure, the port right corresponding to a \a right_type of
//! `MACH_MSG_TYPE_MOVE_*` is not consumed, and the caller must dispose of
//! the right if necessary.
static bool RunClientForFD(base::ScopedFD client_read_fd,
mach_port_t port,
mach_msg_type_name_t right_type);
private:
//! \brief Runs the read-from-pipe portion of the client’s side of the
//! handshake. This is an implementation detail of RunClient and is only
//! exposed for testing purposes.
//!
//! When using this function and RunClientInternal_SendCheckIn(), the caller
//! is responsible for closing \a pipe_read at an appropriate time, normally
//! after calling RunClientInternal_SendCheckIn().
//!
//! \param[in] pipe_read The “read” side of the pipe shared with the server
//! process.
//! \param[out] token The token value read from \a pipe_read.
//! \param[out] service_name The service name as registered with the bootstrap
//! server, read from \a pipe_read.
static void RunClientInternal_ReadPipe(int pipe_read,
//!
//! \return `true` on success, `false` on failure with a message logged.
static bool RunClientInternal_ReadPipe(int pipe_read,
child_port_token_t* token,
std::string* service_name);
@ -188,34 +297,25 @@ class ChildPortHandshake : public ChildPortServer::Interface {
//! This is an implementation detail of RunClient and is only exposed for
//! testing purposes.
//!
//! When using this RunClientInternal_ReadPipe() and this function, the caller
//! is responsible for closing the “read” side of the pipe at an appropriate
//! time, normally after calling this function.
//!
//! \param[in] service_name The service name as registered with the bootstrap
//! server, to be looked up with `bootstrap_look_up()`.
//! \param[in] token The token value to provide during check-in.
//! \param[in] port The port that will be passed to the server by
//! `child_port_check_in()`.
//! \param[in] right_type The right type to furnish the parent with.
static void RunClientInternal_SendCheckIn(const std::string& service_name,
//! \param[in] right_type The right type to furnish the server with.
//!
//! \return `true` on success, `false` on failure with a message logged.
static bool RunClientInternal_SendCheckIn(const std::string& service_name,
child_port_token_t token,
mach_port_t port,
mach_msg_type_name_t right_type);
// Communicates the token from RunServer(), where it’s generated, to
// HandleChildPortCheckIn(), where it’s validated.
child_port_token_t token_;
base::ScopedFD pipe_read_;
base::ScopedFD pipe_write_;
// Communicates the port received from the client from
// HandleChildPortCheckIn(), where it’s received, to RunServer(), where it’s
// returned. This is strongly-owned, but ownership is transferred to
// RunServer()’s caller.
mach_port_t child_port_;
// Communicates that a check-in with a valid token was received by
// HandleChildPortCheckIn(), and that the value of child_port_ should be
// returned to RunServer()’s caller.
bool checked_in_;
base::ScopedFD client_read_fd_;
base::ScopedFD server_write_fd_;
friend class test::ChildPortHandshakeTest;

426
util/mach/child_port_handshake_test.cc
View File

@ -26,161 +26,355 @@ namespace {
class ChildPortHandshakeTest : public Multiprocess {
public:
enum TestType {
kTestTypeChildChecksIn = 0,
kTestTypeChildDoesNotCheckIn_ReadsPipe,
kTestTypeChildDoesNotCheckIn,
kTestTypeTokenIncorrect,
kTestTypeTokenIncorrectThenCorrect,
enum class ClientProcess {
// The child runs the client and the parent runs the server.
kChildClient = 0,
// The parent runs the client and the child runs the server.
kParentClient,
};
explicit ChildPortHandshakeTest(TestType test_type)
: Multiprocess(), child_port_handshake_(), test_type_(test_type) {}
~ChildPortHandshakeTest() {}
enum class TestType {
// The client checks in with the server, transferring a receive right.
kClientChecksIn_ReceiveRight = 0,
// In this test, the client checks in with the server normally. It sends a
// copy of its bootstrap port to the server, because both parent and child
// should have the same bootstrap port, allowing for verification.
kClientChecksIn_SendRight,
// The client checks in with the server, transferring a send-once right.
kClientChecksIn_SendOnceRight,
// In this test, the client reads from its pipe, and subsequently exits
// without checking in. This tests that the server properly detects that it
// has lost its client after sending instructions to it via the pipe, while
// waiting for a check-in message.
kClientDoesNotCheckIn,
// In this test, the client exits without checking in. This tests that the
// server properly detects that it has lost a client. Whether or not the
// client closes the pipe before the server writes to it is a race, and the
// server needs to be able to detect client loss in both cases, so the
// ClientDoesNotCheckIn_ReadsPipe and NoClient tests also exist to test
// these individual cases more deterministically.
kClientDoesNotCheckIn_ReadsPipe,
// In this test, the client checks in with the server with an incorrect
// token value and a copy of its own task port. The server should reject the
// message because of the invalid token, and return MACH_PORT_NULL to its
// caller.
kTokenIncorrect,
// In this test, the client checks in with the server with an incorrect
// token value and a copy of its own task port, and subsequently, the
// correct token value and a copy of its bootstrap port. The server should
// reject the first because of the invalid token, but it should continue
// waiting for a message with a valid token as long as the pipe remains
// open. It should wind wind up returning the bootstrap port, allowing for
// verification.
kTokenIncorrectThenCorrect,
// The server dies. The failure should be reported in the client. This test
// type is only compatible with ClientProcess::kParentClient.
kServerDies,
};
ChildPortHandshakeTest(ClientProcess client_process, TestType test_type)
: Multiprocess(),
child_port_handshake_(),
client_process_(client_process),
test_type_(test_type) {
}
~ChildPortHandshakeTest() {
}
private:
void RunServer() {
if (test_type_ == TestType::kServerDies) {
return;
}
base::mac::ScopedMachReceiveRight receive_right;
base::mac::ScopedMachSendRight send_right;
if (test_type_ == TestType::kClientChecksIn_ReceiveRight) {
receive_right.reset(child_port_handshake_.RunServer(
ChildPortHandshake::PortRightType::kReceiveRight));
} else {
send_right.reset(child_port_handshake_.RunServer(
ChildPortHandshake::PortRightType::kSendRight));
}
switch (test_type_) {
case TestType::kClientChecksIn_ReceiveRight:
EXPECT_TRUE(receive_right.is_valid());
break;
case TestType::kClientChecksIn_SendRight:
case TestType::kTokenIncorrectThenCorrect:
EXPECT_EQ(bootstrap_port, send_right);
break;
case TestType::kClientChecksIn_SendOnceRight:
EXPECT_TRUE(send_right.is_valid());
EXPECT_NE(bootstrap_port, send_right);
break;
case TestType::kClientDoesNotCheckIn:
case TestType::kClientDoesNotCheckIn_ReadsPipe:
case TestType::kTokenIncorrect:
EXPECT_FALSE(send_right.is_valid());
break;
case TestType::kServerDies:
// This was special-cased as an early return above.
FAIL();
break;
}
}
void RunClient() {
switch (test_type_) {
case TestType::kClientChecksIn_SendRight: {
ASSERT_TRUE(child_port_handshake_.RunClient(bootstrap_port,
MACH_MSG_TYPE_COPY_SEND));
break;
}
case TestType::kClientChecksIn_ReceiveRight: {
mach_port_t receive_right = NewMachPort(MACH_PORT_RIGHT_RECEIVE);
ASSERT_TRUE(child_port_handshake_.RunClient(
receive_right, MACH_MSG_TYPE_MOVE_RECEIVE));
break;
}
case TestType::kClientChecksIn_SendOnceRight: {
base::mac::ScopedMachReceiveRight receive_right(
NewMachPort(MACH_PORT_RIGHT_RECEIVE));
ASSERT_TRUE(child_port_handshake_.RunClient(
receive_right.get(), MACH_MSG_TYPE_MAKE_SEND_ONCE));
break;
}
case TestType::kClientDoesNotCheckIn: {
child_port_handshake_.ServerWriteFD().reset();
child_port_handshake_.ClientReadFD().reset();
break;
}
case TestType::kClientDoesNotCheckIn_ReadsPipe: {
// Don’t run the standard client routine. Instead, drain the pipe, which
// will get the parent to the point that it begins waiting for a
// check-in message. Then, exit. The pipe is drained using the same
// implementation that the real client would use.
child_port_handshake_.ServerWriteFD().reset();
base::ScopedFD client_read_fd = child_port_handshake_.ClientReadFD();
child_port_token_t token;
std::string service_name;
ASSERT_TRUE(ChildPortHandshake::RunClientInternal_ReadPipe(
client_read_fd.get(), &token, &service_name));
break;
}
case TestType::kTokenIncorrect: {
// Don’t run the standard client routine. Instead, read the token and
// service name, mutate the token, and then check in with the bad token.
// The parent should reject the message.
child_port_handshake_.ServerWriteFD().reset();
base::ScopedFD client_read_fd = child_port_handshake_.ClientReadFD();
child_port_token_t token;
std::string service_name;
ASSERT_TRUE(ChildPortHandshake::RunClientInternal_ReadPipe(
client_read_fd.get(), &token, &service_name));
child_port_token_t bad_token = ~token;
ASSERT_TRUE(ChildPortHandshake::RunClientInternal_SendCheckIn(
service_name,
bad_token,
mach_task_self(),
MACH_MSG_TYPE_COPY_SEND));
break;
}
case TestType::kTokenIncorrectThenCorrect: {
// Don’t run the standard client routine. Instead, read the token and
// service name. Mutate the token, and check in with the bad token,
// expecting the parent to reject the message. Then, check in with the
// correct token, expecting the parent to accept it.
child_port_handshake_.ServerWriteFD().reset();
base::ScopedFD client_read_fd = child_port_handshake_.ClientReadFD();
child_port_token_t token;
std::string service_name;
ASSERT_TRUE(ChildPortHandshake::RunClientInternal_ReadPipe(
client_read_fd.release(), &token, &service_name));
child_port_token_t bad_token = ~token;
ASSERT_TRUE(ChildPortHandshake::RunClientInternal_SendCheckIn(
service_name,
bad_token,
mach_task_self(),
MACH_MSG_TYPE_COPY_SEND));
ASSERT_TRUE(ChildPortHandshake::RunClientInternal_SendCheckIn(
service_name, token, bootstrap_port, MACH_MSG_TYPE_COPY_SEND));
break;
}
case TestType::kServerDies: {
ASSERT_EQ(ClientProcess::kParentClient, client_process_);
ASSERT_FALSE(child_port_handshake_.RunClient(bootstrap_port,
MACH_MSG_TYPE_COPY_SEND));
break;
}
}
}
// Multiprocess:
void MultiprocessParent() override {
base::mac::ScopedMachSendRight child_port(
child_port_handshake_.RunServer());
switch (test_type_) {
case kTestTypeChildChecksIn:
case kTestTypeTokenIncorrectThenCorrect:
EXPECT_EQ(bootstrap_port, child_port);
switch (client_process_) {
case ClientProcess::kChildClient:
RunServer();
break;
case kTestTypeChildDoesNotCheckIn_ReadsPipe:
case kTestTypeChildDoesNotCheckIn:
case kTestTypeTokenIncorrect:
EXPECT_EQ(kMachPortNull, child_port);
case ClientProcess::kParentClient:
RunClient();
break;
}
}
void MultiprocessChild() override {
int read_pipe = child_port_handshake_.ReadPipeFD();
switch (test_type_) {
case kTestTypeChildChecksIn:
ChildPortHandshake::RunClient(
read_pipe, bootstrap_port, MACH_MSG_TYPE_COPY_SEND);
switch (client_process_) {
case ClientProcess::kChildClient:
RunClient();
break;
case kTestTypeChildDoesNotCheckIn_ReadsPipe: {
// Don’t run the standard client routine. Instead, drain the pipe, which
// will get the parent to the point that it begins waiting for a
// check-in message. Then, exit. The pipe is drained using the same
// implementation that the real client would use.
child_port_token_t token;
std::string service_name;
ChildPortHandshake::RunClientInternal_ReadPipe(
read_pipe, &token, &service_name);
case ClientProcess::kParentClient:
RunServer();
break;
}
case kTestTypeChildDoesNotCheckIn:
break;
case kTestTypeTokenIncorrect: {
// Don’t run the standard client routine. Instead, read the token and
// service name, mutate the token, and then check in with the bad token.
// The parent should reject the message.
child_port_token_t token;
std::string service_name;
ChildPortHandshake::RunClientInternal_ReadPipe(
read_pipe, &token, &service_name);
child_port_token_t bad_token = ~token;
ChildPortHandshake::RunClientInternal_SendCheckIn(
service_name, bad_token, mach_task_self(), MACH_MSG_TYPE_COPY_SEND);
break;
}
case kTestTypeTokenIncorrectThenCorrect: {
// Don’t run the standard client routine. Instead, read the token and
// service name. Mutate the token, and check in with the bad token,
// expecting the parent to reject the message. Then, check in with the
// correct token, expecting the parent to accept it.
child_port_token_t token;
std::string service_name;
ChildPortHandshake::RunClientInternal_ReadPipe(
read_pipe, &token, &service_name);
child_port_token_t bad_token = ~token;
ChildPortHandshake::RunClientInternal_SendCheckIn(
service_name, bad_token, mach_task_self(), MACH_MSG_TYPE_COPY_SEND);
ChildPortHandshake::RunClientInternal_SendCheckIn(
service_name, token, bootstrap_port, MACH_MSG_TYPE_COPY_SEND);
break;
}
}
}
private:
ChildPortHandshake child_port_handshake_;
ClientProcess client_process_;
TestType test_type_;
DISALLOW_COPY_AND_ASSIGN(ChildPortHandshakeTest);
};
TEST(ChildPortHandshake, ChildChecksIn) {
// In this test, the client checks in with the server normally. It sends a
// copy of its bootstrap port to the server, because both parent and child
// should have the same bootstrap port, allowing for verification.
ChildPortHandshakeTest test(ChildPortHandshakeTest::kTestTypeChildChecksIn);
test.Run();
}
TEST(ChildPortHandshake, ChildDoesNotCheckIn) {
// In this test, the client exits without checking in. This tests that the
// server properly detects that it has lost a client. Whether or not the
// client closes the pipe before the server writes to it is a race, and the
// server needs to be able to detect client loss in both cases, so the
// ChildDoesNotCheckIn_ReadsPipe and NoChild tests also exist to test these
// individual cases more deterministically.
TEST(ChildPortHandshake, ChildClientChecksIn_ReceiveRight) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::kTestTypeChildDoesNotCheckIn);
ChildPortHandshakeTest::ClientProcess::kChildClient,
ChildPortHandshakeTest::TestType::kClientChecksIn_ReceiveRight);
test.Run();
}
TEST(ChildPortHandshake, ChildDoesNotCheckIn_ReadsPipe) {
// In this test, the client reads from its pipe, and subsequently exits
// without checking in. This tests that the server properly detects that it
// has lost its client after sending instructions to it via the pipe, while
// waiting for a check-in message.
TEST(ChildPortHandshake, ChildClientChecksIn_SendRight) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::kTestTypeChildDoesNotCheckIn_ReadsPipe);
ChildPortHandshakeTest::ClientProcess::kChildClient,
ChildPortHandshakeTest::TestType::kClientChecksIn_SendRight);
test.Run();
}
TEST(ChildPortHandshake, TokenIncorrect) {
// In this test, the client checks in with the server with an incorrect token
// value and a copy of its own task port. The server should reject the message
// because of the invalid token, and return MACH_PORT_NULL to its caller.
ChildPortHandshakeTest test(ChildPortHandshakeTest::kTestTypeTokenIncorrect);
test.Run();
}
TEST(ChildPortHandshake, TokenIncorrectThenCorrect) {
// In this test, the client checks in with the server with an incorrect token
// value and a copy of its own task port, and subsequently, the correct token
// value and a copy of its bootstrap port. The server should reject the first
// because of the invalid token, but it should continue waiting for a message
// with a valid token as long as the pipe remains open. It should wind wind up
// returning the bootstrap port, allowing for verification.
TEST(ChildPortHandshake, ChildClientChecksIn_SendOnceRight) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::kTestTypeTokenIncorrectThenCorrect);
ChildPortHandshakeTest::ClientProcess::kChildClient,
ChildPortHandshakeTest::TestType::kClientChecksIn_SendOnceRight);
test.Run();
}
TEST(ChildPortHandshake, NoChild) {
// In this test, the client never checks in with the parent because the child
// never even runs. This tests that the server properly detects that it has
// no client at all, and does not terminate execution with an error such as
TEST(ChildPortHandshake, ChildClientDoesNotCheckIn) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kChildClient,
ChildPortHandshakeTest::TestType::kClientDoesNotCheckIn);
test.Run();
}
TEST(ChildPortHandshake, ChildClientDoesNotCheckIn_ReadsPipe) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kChildClient,
ChildPortHandshakeTest::TestType::kClientDoesNotCheckIn_ReadsPipe);
test.Run();
}
TEST(ChildPortHandshake, ChildClientTokenIncorrect) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kChildClient,
ChildPortHandshakeTest::TestType::kTokenIncorrect);
test.Run();
}
TEST(ChildPortHandshake, ChildClientTokenIncorrectThenCorrect) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kChildClient,
ChildPortHandshakeTest::TestType::kTokenIncorrectThenCorrect);
test.Run();
}
TEST(ChildPortHandshake, ParentClientChecksIn_ReceiveRight) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kParentClient,
ChildPortHandshakeTest::TestType::kClientChecksIn_ReceiveRight);
test.Run();
}
TEST(ChildPortHandshake, ParentClientChecksIn_SendRight) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kParentClient,
ChildPortHandshakeTest::TestType::kClientChecksIn_SendRight);
test.Run();
}
TEST(ChildPortHandshake, ParentClientChecksIn_SendOnceRight) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kParentClient,
ChildPortHandshakeTest::TestType::kClientChecksIn_SendOnceRight);
test.Run();
}
TEST(ChildPortHandshake, ParentClientDoesNotCheckIn) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kParentClient,
ChildPortHandshakeTest::TestType::kClientDoesNotCheckIn);
test.Run();
}
TEST(ChildPortHandshake, ParentClientDoesNotCheckIn_ReadsPipe) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kParentClient,
ChildPortHandshakeTest::TestType::kClientDoesNotCheckIn_ReadsPipe);
test.Run();
}
TEST(ChildPortHandshake, ParentClientTokenIncorrect) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kParentClient,
ChildPortHandshakeTest::TestType::kTokenIncorrect);
test.Run();
}
TEST(ChildPortHandshake, ParentClientTokenIncorrectThenCorrect) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kParentClient,
ChildPortHandshakeTest::TestType::kTokenIncorrectThenCorrect);
test.Run();
}
TEST(ChildPortHandshake, ParentClientServerDies) {
ChildPortHandshakeTest test(
ChildPortHandshakeTest::ClientProcess::kParentClient,
ChildPortHandshakeTest::TestType::kServerDies);
test.Run();
}
TEST(ChildPortHandshake, NoClient) {
// In this test, the client never checks in with the server because it never
// even runs. This tests that the server properly detects that it has no
// client at all, and does not terminate execution with an error such as
// “broken pipe” when attempting to send instructions to the client. This test
// is similar to ChildDoesNotCheckIn, but because there’s no child at all, the
// server is guaranteed to see that its pipe partner is gone.
// is similar to kClientDoesNotCheckIn, but because there’s no client at all,
// the server is guaranteed to see that its pipe partner is gone.
ChildPortHandshake child_port_handshake;
base::mac::ScopedMachSendRight child_port(child_port_handshake.RunServer());
EXPECT_EQ(kMachPortNull, child_port);
base::mac::ScopedMachSendRight child_port(child_port_handshake.RunServer(
ChildPortHandshake::PortRightType::kSendRight));
EXPECT_FALSE(child_port.is_valid());
}
} // namespace

34
util/mach/mach_message.cc
View File

@ -20,6 +20,7 @@
#include <limits>
#include "base/logging.h"
#include "base/mac/mach_logging.h"
#include "util/misc/clock.h"
#include "util/misc/implicit_cast.h"
@ -249,4 +250,37 @@ pid_t AuditPIDFromMachMessageTrailer(const mach_msg_trailer_t* trailer) {
return audit_pid;
}
bool MachMessageDestroyReceivedPort(mach_port_t port,
mach_msg_type_name_t port_right_type) {
// This implements a subset of 10.10.5
// xnu-2782.40.9/libsyscall/mach/mach_msg.c mach_msg_destroy_port() that deals
// only with port rights that can be received in Mach messages.
switch (port_right_type) {
case MACH_MSG_TYPE_PORT_RECEIVE: {
kern_return_t kr = mach_port_mod_refs(
mach_task_self(), port, MACH_PORT_RIGHT_RECEIVE, -1);
if (kr != KERN_SUCCESS) {
MACH_LOG(ERROR, kr) << "mach_port_mod_refs";
return false;
}
return true;
}
case MACH_MSG_TYPE_PORT_SEND:
case MACH_MSG_TYPE_PORT_SEND_ONCE: {
kern_return_t kr = mach_port_deallocate(mach_task_self(), port);
if (kr != KERN_SUCCESS) {
MACH_LOG(ERROR, kr) << "mach_port_deallocate";
return false;
}
return true;
}
default: {
LOG(ERROR) << "unexpected port right type " << port_right_type;
return false;
}
}
}
} // namespace crashpad

15
util/mach/mach_message.h
View File

@ -174,6 +174,21 @@ const mach_msg_trailer_t* MachMessageTrailerFromHeader(
//! audit information.
pid_t AuditPIDFromMachMessageTrailer(const mach_msg_trailer_t* trailer);
//! \brief Destroys or deallocates a Mach port received in a Mach message.
//!
//! This function disposes of port rights received in a Mach message. Receive
//! rights will be destroyed with `mach_port_mod_refs()`. Send and send-once
//! rights will be deallocated with `mach_port_deallocate()`.
//!
//! \param[in] port The port to destroy or deallocate.
//! \param[in] port_right_type The right type held for \a port:
//! `MACH_MSG_TYPE_PORT_RECEIVE`, `MACH_MSG_TYPE_PORT_SEND`, or
//! `MACH_MSG_TYPE_PORT_SEND_ONCE`.
//!
//! \return `true` on success, or `false` on failure with a message logged.
bool MachMessageDestroyReceivedPort(mach_port_t port,
mach_msg_type_name_t port_right_type);
} // namespace crashpad
#endif // CRASHPAD_UTIL_MACH_MACH_MESSAGE_H_

16
util/mach/mach_message_server_test.cc
View File

@ -216,8 +216,8 @@ class TestMachMessageServer : public MachMessageServer::Interface,
MACH_MSGH_BITS(MACH_MSG_TYPE_MOVE_SEND, MACH_MSG_TYPE_MOVE_SEND) |
(options_.client_send_complex ? MACH_MSGH_BITS_COMPLEX : 0);
EXPECT_EQ(expect_msgh_bits, request->header.msgh_bits);
EXPECT_EQ(options_.client_send_large ? sizeof(LargeRequestMessage) :
sizeof(RequestMessage),
EXPECT_EQ(options_.client_send_large ? sizeof(LargeRequestMessage)
: sizeof(RequestMessage),
request->header.msgh_size);
if (options_.client_reply_port_type == Options::kReplyPortNormal) {
EXPECT_EQ(RemotePort(), request->header.msgh_remote_port);
@ -277,8 +277,8 @@ class TestMachMessageServer : public MachMessageServer::Interface,
std::set<mach_msg_id_t> MachMessageServerRequestIDs() override {
const mach_msg_id_t request_ids[] = {kRequestMessageID};
return std::set<mach_msg_id_t>(
&request_ids[0], &request_ids[arraysize(request_ids)]);
return std::set<mach_msg_id_t>(&request_ids[0],
&request_ids[arraysize(request_ids)]);
}
mach_msg_size_t MachMessageServerRequestSize() override {
@ -368,8 +368,8 @@ class TestMachMessageServer : public MachMessageServer::Interface,
EXPECT_EQ(MACH_PORT_TYPE_SEND, type);
// Destroy the resources here.
kr = mach_port_deallocate(
mach_task_self(), parent_complex_message_port_);
kr = mach_port_deallocate(mach_task_self(),
parent_complex_message_port_);
EXPECT_EQ(KERN_SUCCESS, kr)
<< MachErrorMessage(kr, "mach_port_deallocate");
}
@ -378,8 +378,8 @@ class TestMachMessageServer : public MachMessageServer::Interface,
// this task so soon. It’s possible that something else in this task could
// have reused the name, but it’s unlikely for that to have happened in
// this test environment.
kr = mach_port_type(
mach_task_self(), parent_complex_message_port_, &type);
kr =
mach_port_type(mach_task_self(), parent_complex_message_port_, &type);
EXPECT_EQ(KERN_INVALID_NAME, kr)
<< MachErrorMessage(kr, "mach_port_type");
}

50
util/mach/mach_message_test.cc
View File

@ -16,6 +16,7 @@
#include <unistd.h>
#include "base/basictypes.h"
#include "base/mac/scoped_mach_port.h"
#include "gtest/gtest.h"
#include "test/mac/mach_errors.h"
@ -148,6 +149,55 @@ TEST(MachMessage, AuditPIDFromMachMessageTrailer) {
EXPECT_EQ(getpid(), AuditPIDFromMachMessageTrailer(&receive.trailer));
}
TEST(MachMessage, MachMessageDestroyReceivedPort) {
mach_port_t port = NewMachPort(MACH_PORT_RIGHT_RECEIVE);
ASSERT_NE(kMachPortNull, port);
EXPECT_TRUE(MachMessageDestroyReceivedPort(port, MACH_MSG_TYPE_PORT_RECEIVE));
base::mac::ScopedMachReceiveRight receive(
NewMachPort(MACH_PORT_RIGHT_RECEIVE));
mach_msg_type_name_t right_type;
kern_return_t kr = mach_port_extract_right(mach_task_self(),
receive.get(),
MACH_MSG_TYPE_MAKE_SEND,
&port,
&right_type);
ASSERT_EQ(KERN_SUCCESS, kr)
<< MachErrorMessage(kr, "mach_port_extract_right");
ASSERT_EQ(receive, port);
ASSERT_EQ(implicit_cast<mach_msg_type_name_t>(MACH_MSG_TYPE_PORT_SEND),
right_type);
EXPECT_TRUE(MachMessageDestroyReceivedPort(port, MACH_MSG_TYPE_PORT_SEND));
kr = mach_port_extract_right(mach_task_self(),
receive.get(),
MACH_MSG_TYPE_MAKE_SEND_ONCE,
&port,
&right_type);
ASSERT_EQ(KERN_SUCCESS, kr)
<< MachErrorMessage(kr, "mach_port_extract_right");
ASSERT_NE(kMachPortNull, port);
EXPECT_NE(receive, port);
ASSERT_EQ(implicit_cast<mach_msg_type_name_t>(MACH_MSG_TYPE_PORT_SEND_ONCE),
right_type);
EXPECT_TRUE(
MachMessageDestroyReceivedPort(port, MACH_MSG_TYPE_PORT_SEND_ONCE));
kr = mach_port_extract_right(mach_task_self(),
receive.get(),
MACH_MSG_TYPE_MAKE_SEND,
&port,
&right_type);
ASSERT_EQ(KERN_SUCCESS, kr)
<< MachErrorMessage(kr, "mach_port_extract_right");
ASSERT_EQ(receive, port);
ASSERT_EQ(implicit_cast<mach_msg_type_name_t>(MACH_MSG_TYPE_PORT_SEND),
right_type);
EXPECT_TRUE(MachMessageDestroyReceivedPort(port, MACH_MSG_TYPE_PORT_RECEIVE));
ignore_result(receive.release());
EXPECT_TRUE(MachMessageDestroyReceivedPort(port, MACH_MSG_TYPE_PORT_SEND));
}
} // namespace
} // namespace test
} // namespace crashpad