Merge commit '86cc97e55fe346502462284d2e636a2b3708163e' as 'Sources/OpenVPN3'

2026-04-24 00:00:05 +08:00 · 2020-02-24 14:43:11 +03:00
parent 133b3756e6 86cc97e55f
commit 32f1555929
655 changed files with 146468 additions and 0 deletions
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+//    OpenVPN -- An application to securely tunnel IP networks
+//               over a single port, with support for SSL/TLS-based
+//               session authentication and key exchange,
+//               packet encryption, packet authentication, and
+//               packet compression.
+//
+//    Copyright (C) 2012-2017 OpenVPN Inc.
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Affero General Public License Version 3
+//    as published by the Free Software Foundation.
+//
+//    This program is distributed in the hope that it will be useful,
+//    but WITHOUT ANY WARRANTY; without even the implied warranty of
+//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//    GNU Affero General Public License for more details.
+//
+//    You should have received a copy of the GNU Affero General Public License
+//    along with this program in the COPYING file.
+//    If not, see <http://www.gnu.org/licenses/>.
+
+// Define the UDP header
+
+#ifndef OPENVPN_IP_UDP_H
+#define OPENVPN_IP_UDP_H
+
+#include <openvpn/ip/ipcommon.hpp>
+
+namespace openvpn {
+
+#pragma pack(push)
+#pragma pack(1)
+
+  struct UDPHeader {
+    std::uint16_t   source;
+    std::uint16_t   dest;
+    std::uint16_t   len;
+    std::uint16_t   check;
+  };
+
+#pragma pack(pop)
+
+  inline std::uint16_t udp_checksum (const std::uint8_t *buf,
+				     const unsigned int len_udp,
+				     const std::uint8_t *src_addr,
+				     const std::uint8_t *dest_addr)
+  {
+    std::uint32_t sum = 0;
+
+    /* make 16 bit words out of every two adjacent 8 bit words and  */
+    /* calculate the sum of all 16 bit words */
+    for (unsigned int i = 0; i < len_udp; i += 2)
+      {
+	std::uint16_t word16 = ((buf[i] << 8) & 0xFF00) + ((i + 1 < len_udp) ? (buf[i+1] & 0xFF) : 0);
+	sum += word16;
+      }
+
+    /* add the UDP pseudo header which contains the IP source and destination addresses */
+    for (unsigned int i = 0; i < 4; i += 2)
+      {
+	std::uint16_t word16 =((src_addr[i] << 8) & 0xFF00) + (src_addr[i+1] & 0xFF);
+	sum += word16;
+      }
+    for (unsigned int i = 0; i < 4; i += 2)
+      {
+	std::uint16_t word16 =((dest_addr[i] << 8) & 0xFF00) + (dest_addr[i+1] & 0xFF);
+	sum += word16;
+      }
+
+    /* the protocol number and the length of the UDP packet */
+    sum += (std::uint16_t)IPCommon::UDP + (std::uint16_t)len_udp;
+
+    /* keep only the last 16 bits of the 32 bit calculated sum and add the carries */
+    while (sum >> 16)
+      sum = (sum & 0xFFFF) + (sum >> 16);
+
+    /* take the one's complement of sum */
+    return std::uint16_t(~sum);
+  }
+
+}
+
+#endif