Fix child process spawning on linux (#773)

src/platform/common.h

@@ -33,6 +33,7 @@ class path;
 }
 namespace process {
 class child;
+class group;
 template<typename Char>
 class basic_environment;
 typedef basic_environment<char> environment;
@@ -323,7 +324,7 @@ std::shared_ptr<display_t> display(mem_type_e hwdevice_type, const std::string &
 // A list of names of displays accepted as display_name with the mem_type_e
 std::vector<std::string> display_names(mem_type_e hwdevice_type);
 
-boost::process::child run_unprivileged(const std::string &cmd, boost::filesystem::path &working_dir, boost::process::environment &env, FILE *file, std::error_code &ec);
+boost::process::child run_unprivileged(const std::string &cmd, boost::filesystem::path &working_dir, boost::process::environment &env, FILE *file, std::error_code &ec, boost::process::group *group);
 
 enum class thread_priority_e : int {
   low,

src/platform/linux/misc.cpp

@@ -145,8 +145,9 @@ std::string get_mac_address(const std::string_view &address) {
   return "00:00:00:00:00:00"s;
 }
 
-bp::child run_unprivileged(const std::string &cmd, boost::filesystem::path &working_dir, bp::environment &env, FILE *file, std::error_code &ec) {
+bp::child run_unprivileged(const std::string &cmd, boost::filesystem::path &working_dir, bp::environment &env, FILE *file, std::error_code &ec, bp::group *group) {
   BOOST_LOG(warning) << "run_unprivileged() is not yet implemented for this platform. The new process will run with Sunshine's permissions."sv;
+  if(!group) {
     if(!file) {
       return bp::child(cmd, env, bp::start_dir(working_dir), bp::std_out > bp::null, bp::std_err > bp::null, ec);
     }
@@ -154,6 +155,15 @@ bp::child run_unprivileged(const std::string &cmd, boost::filesystem::path &work
       return bp::child(cmd, env, bp::start_dir(working_dir), bp::std_out > file, bp::std_err > file, ec);
     }
   }
+  else {
+    if(!file) {
+      return bp::child(cmd, env, bp::start_dir(working_dir), bp::std_out > bp::null, bp::std_err > bp::null, ec, *group);
+    }
+    else {
+      return bp::child(cmd, env, bp::start_dir(working_dir), bp::std_out > file, bp::std_err > file, ec, *group);
+    }
+  }
+}
 
 void adjust_thread_priority(thread_priority_e priority) {
   // Unimplemented

src/platform/macos/misc.cpp

@@ -121,8 +121,9 @@ std::string get_mac_address(const std::string_view &address) {
   return "00:00:00:00:00:00"s;
 }
 
-bp::child run_unprivileged(const std::string &cmd, boost::filesystem::path &working_dir, bp::environment &env, FILE *file, std::error_code &ec) {
+bp::child run_unprivileged(const std::string &cmd, boost::filesystem::path &working_dir, bp::environment &env, FILE *file, std::error_code &ec, bp::group *group) {
   BOOST_LOG(warning) << "run_unprivileged() is not yet implemented for this platform. The new process will run with Sunshine's permissions."sv;
+  if(!group) {
     if(!file) {
       return bp::child(cmd, env, bp::start_dir(working_dir), bp::std_out > bp::null, bp::std_err > bp::null, ec);
     }
@@ -130,6 +131,15 @@ bp::child run_unprivileged(const std::string &cmd, boost::filesystem::path &work
       return bp::child(cmd, env, bp::start_dir(working_dir), bp::std_out > file, bp::std_err > file, ec);
     }
   }
+  else {
+    if(!file) {
+      return bp::child(cmd, env, bp::start_dir(working_dir), bp::std_out > bp::null, bp::std_err > bp::null, ec, *group);
+    }
+    else {
+      return bp::child(cmd, env, bp::start_dir(working_dir), bp::std_out > file, bp::std_err > file, ec, *group);
+    }
+  }
+}
 
 void adjust_thread_priority(thread_priority_e priority) {
   // Unimplemented

src/platform/windows/misc.cpp

@@ -375,7 +375,7 @@ void free_proc_thread_attr_list(LPPROC_THREAD_ATTRIBUTE_LIST list) {
   HeapFree(GetProcessHeap(), 0, list);
 }
 
-bp::child run_unprivileged(const std::string &cmd, boost::filesystem::path &working_dir, bp::environment &env, FILE *file, std::error_code &ec) {
+bp::child run_unprivileged(const std::string &cmd, boost::filesystem::path &working_dir, bp::environment &env, FILE *file, std::error_code &ec, bp::group *group) {
   HANDLE shell_token = duplicate_shell_token();
   if(!shell_token) {
     // This can happen if the shell has crashed. Fail the launch rather than risking launching with
@@ -490,6 +490,9 @@ bp::child run_unprivileged(const std::string &cmd, boost::filesystem::path &work
     // Since we are always spawning a process with a less privileged token than ourselves,
     // bp::child() should have no problem opening it with any access rights it wants.
     auto child = bp::child((bp::pid_t)process_info.dwProcessId);
+    if(group) {
+      group->add(child);
+    }
 
     // Only close handles after bp::child() has opened the process. If the process terminates
     // quickly, the PID could be reused if we close the process handle.

src/process.cpp

@@ -150,7 +150,7 @@ int proc_t::execute(int app_id) {
                                             find_working_directory(cmd, _env) :
                                             boost::filesystem::path(proc.working_dir);
     BOOST_LOG(info) << "Spawning ["sv << cmd << "] in ["sv << working_dir << ']';
-    auto child = platf::run_unprivileged(cmd, working_dir, _env, _pipe.get(), ec);
+    auto child = platf::run_unprivileged(cmd, working_dir, _env, _pipe.get(), ec, nullptr);
     if(ec) {
       BOOST_LOG(warning) << "Couldn't spawn ["sv << cmd << "]: System: "sv << ec.message();
     }
@@ -168,13 +168,11 @@ int proc_t::execute(int app_id) {
                                             find_working_directory(proc.cmd, _env) :
                                             boost::filesystem::path(proc.working_dir);
     BOOST_LOG(info) << "Executing: ["sv << proc.cmd << "] in ["sv << working_dir << ']';
-    _process = platf::run_unprivileged(proc.cmd, working_dir, _env, _pipe.get(), ec);
+    _process = platf::run_unprivileged(proc.cmd, working_dir, _env, _pipe.get(), ec, &_process_handle);
     if(ec) {
       BOOST_LOG(warning) << "Couldn't run ["sv << proc.cmd << "]: System: "sv << ec.message();
       return -1;
     }
-
-    _process_handle.add(_process);
   }
 
   fg.disable();