Squashed 'Sources/OpenVPNAdapter/Libraries/Vendors/openvpn/' changes from 554d8b888..cc90cde57

cc90cde57 win: use 'MSVC 2017 Professional' as default compiler
4b072bce1 [OVPN3-311] function.hpp: fix Windows build
48b9b78de [OVPN3-310] logging: fix 'OPENVPN_LOG_NTNL': identifier not found
5a4a87552 cosmetics: helper function to check registry errors
fc52fd8a5 [OC-78] proxy: support PROXY_AUTO_CONFIG_URL on Windows
f5178cff9 [OC-77] proxy: refactor proxy settings code
18e50ec3f ReplyParser: added undefined status
8178ae06f unix file utils: added update_file_mod_time_nanoseconds()
8f20f7693 build: use LZ4_SYS=1 default when target is Linux
4bd996e61 timestr: added date_time_utc() and nanosec_time_to_string()
0eaa2586f string: added remove_spaces() method
d47ae03cc OptionList: added get_c_str() method
1eb9cd657 unix file utils: added mtime_ns parameter to write_binary_unix() and write_binary_atomic()
bf00c6e3e Time::delta_str(): use "INF" to denote infinite time
0e598a87b kovpn.hpp: asio must be included before sys/ and linux/ headers to avoid redefinition conflicts
1d2ce460d BufferType: added read_alloc_buf() method
148ae6085 BufferType: added reset_offset() method
6218ed618 Factor out IP::random_addr_v4() and IP::random_addr_v6() from IP::random_addr().
5468670b9 pool: minor changes
36a885a82 route: allow for specialized IPv4/v6 RouteType
5e29e6628 BufferType: added typedef T value_type
d92021c99 strerror.hpp: added #include <errno.h> for benefit of users
363cbece3 Function: misc cleanup
d88435ecd IP::Route: added defined() method
3371cb745 kovpn.hpp: fix centos build with DCO enabled
dc9e48d98 Fix bug in macos tunnel interface setup. Second ip address should be gateway address
bcdb27993 Merged in schwabe/fix_clang_warnings (pull request #25)
ede5e90ff Merged in schabe/fix_swig_ipadr (pull request #27)
c0d580d24 Merged in schwabe/fix_openvpn_extern (pull request #26)
0965882e5 Merged in schwabe/stats_morecpus (pull request #23)
5f1f8470b Revert bugfix for not compiling IA32 ASM of 2.7.5
bde2c41be dep: switch from mbeTLS 2.7.0 to 2.7.5
9d06b5c97 [OC-77] proxy: support PROXY_AUTO_CONFIG_URL on macOS
3f2ad8e8c Hide const std::string IP methods from SWIG
ba264862a Send also kovpn statistics of CPU Cores >= 16 via status message
2991d38b3 Fix warnings reported by LLVM/Clang
02d2a7975 Fix multiple inclusion of OpenVPN3 header with OPENPVN_EXTERN

git-subtree-dir: Sources/OpenVPNAdapter/Libraries/Vendors/openvpn
git-subtree-split: cc90cde5769dcf9e13fdd9e85d6d0857963dabce

openvpn/buffer/buffer.hpp

@@ -82,6 +82,7 @@ namespace openvpn {
       buffer_headroom,
       buffer_underflow,
       buffer_overflow,
+      buffer_offset,
       buffer_index,
       buffer_const_index,
       buffer_push_front_headroom,
@@ -108,6 +109,8 @@ namespace openvpn {
 	  return "buffer_underflow";
 	case buffer_overflow:
 	  return "buffer_overflow";
+	case buffer_offset:
+	  return "buffer_offset";
 	case buffer_index:
 	  return "buffer_index";
 	case buffer_const_index:
@@ -144,6 +147,7 @@ namespace openvpn {
     template <typename, typename> friend class BufferAllocatedType;
 
   public:
+    typedef T value_type;
     typedef T* type;
     typedef const T* const_type;
     typedef typename std::remove_const<T>::type NCT; // non-const type
@@ -177,6 +181,15 @@ namespace openvpn {
       size_ = 0;
     }
 
+    void reset_offset(const size_t offset)
+    {
+      const size_t size = size_ + offset_ - offset;
+      if (offset > capacity_ || size > capacity_ || offset + size > capacity_)
+	OPENVPN_BUFFER_THROW(buffer_offset);
+      offset_ = offset;
+      size_ = size;
+    }
+
     void reset_size()
     {
       size_ = 0;
@@ -519,6 +532,19 @@ namespace openvpn {
 	OPENVPN_BUFFER_THROW(buffer_underflow);
     }
 
+    BufferType read_alloc_buf(const size_t size)
+    {
+      if (size <= size_)
+	{
+	  BufferType ret(data_, offset_, size, capacity_);
+	  offset_ += size;
+	  size_ -= size;
+	  return ret;
+	}
+      else
+	OPENVPN_BUFFER_THROW(buffer_underflow);
+    }
+
     void reset(const size_t min_capacity, const unsigned int flags)
     {
       if (min_capacity > capacity_)