From 9ed6a6fa482545f6238d1719bce7681737e2c1d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Steffen=20Kie=C3=9F?= <Steffen.Kiess@ipvs.uni-stuttgart.de>
Date: Fri, 13 Oct 2017 11:23:58 +0200
Subject: [PATCH] Add support for Unix FDs

---
 include/dbus-c++/message.h |  4 +++
 include/dbus-c++/types.h   | 34 ++++++++++++++++++++++
 src/message.cpp            | 31 +++++++++++++++++++-
 src/types.cpp              | 58 ++++++++++++++++++++++++++++++++++++++
 tools/generator_utils.cpp  |  1 +
 5 files changed, 127 insertions(+), 1 deletion(-)

diff --git a/include/dbus-c++/message.h b/include/dbus-c++/message.h
index a9041d8..1d07fdd 100644
--- a/include/dbus-c++/message.h
+++ b/include/dbus-c++/message.h
@@ -107,6 +107,10 @@ class DXXAPI MessageIter
 
   char *signature() const; //returned string must be manually free()'d
 
+  bool append_unix_fd(int fd);
+
+  int get_unix_fd();
+
   MessageIter recurse();
 
   bool append_array(char type, const void *ptr, size_t length);
diff --git a/include/dbus-c++/types.h b/include/dbus-c++/types.h
index 7b3108f..b5d798e 100644
--- a/include/dbus-c++/types.h
+++ b/include/dbus-c++/types.h
@@ -64,6 +64,21 @@ struct DXXAPI Signature : public std::string
 
 struct DXXAPI Invalid {};
 
+class DXXAPI UnixFD
+{
+public:
+  UnixFD();
+  explicit UnixFD(int fd);
+  ~UnixFD();
+  UnixFD(const UnixFD& o);
+  UnixFD& operator = (const UnixFD& o);
+
+  int fd() const { return _fd; }
+
+private:
+  int _fd;
+};
+
 class DXXAPI Variant
 {
 public:
@@ -241,6 +256,13 @@ template <> struct type<Signature>
     return "g";
   }
 };
+template <> struct type<UnixFD>
+{
+  static std::string sig()
+  {
+    return "h";
+  }
+};
 template <> struct type<Invalid>
 {
   static std::string sig()
@@ -389,6 +411,12 @@ inline DBus::MessageIter &operator << (DBus::MessageIter &iter, const DBus::Sign
   return iter;
 }
 
+inline DBus::MessageIter &operator << (DBus::MessageIter &iter, const DBus::UnixFD &val)
+{
+  iter.append_unix_fd(val.fd());
+  return iter;
+}
+
 template<typename E>
 inline DBus::MessageIter &operator << (DBus::MessageIter &iter, const std::vector<E>& val)
 {
@@ -545,6 +573,12 @@ inline DBus::MessageIter &operator >> (DBus::MessageIter &iter, DBus::Signature
   return ++iter;
 }
 
+inline DBus::MessageIter &operator >> (DBus::MessageIter &iter, DBus::UnixFD &val)
+{
+  val = DBus::UnixFD(iter.get_unix_fd());
+  return ++iter;
+}
+
 extern DXXAPI DBus::MessageIter &operator >> (DBus::MessageIter &iter, DBus::Variant &val);
 
 template<typename E>
diff --git a/src/message.cpp b/src/message.cpp
index eacea92..34ecca2 100644
--- a/src/message.cpp
+++ b/src/message.cpp
@@ -30,6 +30,10 @@
 #include <dbus/dbus.h>
 #include <cstdlib>
 
+#if !HAVE_WIN32
+#include <unistd.h>
+#endif
+
 #include "internalerror.h"
 #include "message_p.h"
 
@@ -224,6 +228,18 @@ const char *MessageIter::get_signature()
   return chars;
 }
 
+bool MessageIter::append_unix_fd(int fd)
+{
+  return append_basic(DBUS_TYPE_UNIX_FD, &fd);
+}
+
+int MessageIter::get_unix_fd()
+{
+  int fd;
+  get_basic(DBUS_TYPE_UNIX_FD, &fd);
+  return fd;
+}
+
 MessageIter MessageIter::recurse()
 {
   MessageIter iter(msg());
@@ -320,6 +336,7 @@ static bool is_basic_type(int typecode)
   case 's':
   case 'o':
   case 'g':
+  case 'h':
     return true;
   default:
     return false;
@@ -330,7 +347,19 @@ void MessageIter::copy_data(MessageIter &to)
 {
   for (MessageIter &from = *this; !from.at_end(); ++from)
   {
-    if (is_basic_type(from.type()))
+    if (from.type() == 'h')
+    {
+#if HAVE_WIN32
+      throw ErrorInvalidArgs("Unix FDs not supported under windows");
+#else
+      debug_log("copying unix fd");
+
+      int fd = from.get_unix_fd();
+      to.append_unix_fd(fd);
+      close(fd);
+#endif
+    }
+    else if (is_basic_type(from.type()))
     {
       debug_log("copying basic type: %c", from.type());
 
diff --git a/src/types.cpp b/src/types.cpp
index 70f9ac0..88013cb 100644
--- a/src/types.cpp
+++ b/src/types.cpp
@@ -31,11 +31,69 @@
 #include <cstdlib>
 #include <stdarg.h>
 
+#if !HAVE_WIN32
+#include <errno.h>
+#include <unistd.h>
+#endif
+
 #include "message_p.h"
 #include "internalerror.h"
 
 namespace DBus {
 
+UnixFD::UnixFD()
+  : _fd(-1)
+{
+}
+
+UnixFD::UnixFD(int fd)
+  : _fd(fd)
+{
+#if HAVE_WIN32
+  if (_fd != -1)
+    throw ErrorInvalidArgs("Unix FDs not supported under windows");
+#endif
+}
+
+UnixFD::~UnixFD()
+{
+#if !HAVE_WIN32
+  if (_fd != -1)
+    close (_fd);
+#endif
+}
+
+UnixFD::UnixFD(const UnixFD &o)
+{
+  _fd = -1;
+#if !HAVE_WIN32
+  if (o._fd != -1) {
+    _fd = dup(o._fd);
+    if (_fd == -1)
+      throw Error("dup:errno", toString(errno).c_str());
+  }
+#endif
+}
+
+UnixFD &UnixFD::operator=(const UnixFD &o)
+{
+  if (this == &o)
+    return *this;
+
+#if !HAVE_WIN32
+  if (_fd != -1) {
+    close (_fd);
+    _fd = -1;
+  }
+  if (o._fd != -1) {
+    _fd = dup(o._fd);
+    if (_fd == -1)
+      throw Error("dup:errno", toString(errno).c_str());
+  }
+#endif
+  return *this;
+}
+
 Variant::Variant()
   : _msg(CallMessage()) // dummy message used as temporary storage for variant data
 {
diff --git a/tools/generator_utils.cpp b/tools/generator_utils.cpp
index 5686f6b..74499e3 100644
--- a/tools/generator_utils.cpp
+++ b/tools/generator_utils.cpp
@@ -69,6 +69,7 @@ const char *atomic_type_to_string(char t)
     { 's', "std::string" },
     { 'o', "::DBus::Path" },
     { 'g', "::DBus::Signature" },
+    { 'h', "::DBus::UnixFD" },
     { 'v', "::DBus::Variant" },
     { '\0', "" }
   };