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
@@ -0,0 +1,113 @@
+//    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) 2012-2018 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/>.
+
+#pragma once
+
+#include <string>
+#include <cstring>
+#include <utility>
+
+#include <openvpn/common/size.hpp>
+#include <openvpn/common/socktypes.hpp>
+#include <openvpn/buffer/buffer.hpp>
+#include <openvpn/addr/ipv4.hpp>
+#include <openvpn/ip/ipcommon.hpp>
+#include <openvpn/ip/icmp4.hpp>
+#include <openvpn/ip/csum.hpp>
+
+namespace openvpn {
+  namespace Ping4 {
+
+    inline void generate_echo_request(Buffer& buf,
+				      const IPv4::Addr& src,
+				      const IPv4::Addr& dest,
+				      const void *extra_data,
+				      const size_t extra_data_size,
+				      const unsigned int id,
+				      const unsigned int seq_num,
+				      const size_t total_size,
+				      std::string* log_info)
+    {
+      const unsigned int data_size = std::max(int(extra_data_size), int(total_size) - int(sizeof(ICMPv4)));
+
+      if (log_info)
+	*log_info = "PING4 " + src.to_string() + " -> " + dest.to_string() + " id=" + std::to_string(id) + " seq_num=" + std::to_string(seq_num) + " data_size=" + std::to_string(data_size);
+
+      std::uint8_t *b = buf.write_alloc(sizeof(ICMPv4) + data_size);
+      ICMPv4 *icmp = (ICMPv4 *)b;
+
+      // IP Header
+      icmp->head.version_len = IPv4Header::ver_len(4, sizeof(IPv4Header));
+      icmp->head.tos = 0;
+      icmp->head.tot_len = htons(sizeof(ICMPv4) + data_size);
+      icmp->head.id = 0;
+      icmp->head.frag_off = 0;
+      icmp->head.ttl = 64;
+      icmp->head.protocol = IPCommon::ICMPv4;
+      icmp->head.check = 0;
+      icmp->head.saddr = src.to_uint32_net();
+      icmp->head.daddr = dest.to_uint32_net();
+      icmp->head.check = IPChecksum::checksum(b, sizeof(IPv4Header));
+
+      // ICMP header
+      icmp->type = ICMPv4::ECHO_REQUEST;
+      icmp->code = 0;
+      icmp->checksum = 0;
+      icmp->id = ntohs(id);
+      icmp->seq_num = ntohs(seq_num);
+
+      // Data
+      std::uint8_t *data = b + sizeof(ICMPv4);
+      for (size_t i = 0; i < data_size; ++i)
+	data[i] = (std::uint8_t)i;
+
+      // Extra data
+      std::memcpy(data, extra_data, extra_data_size);
+
+      // ICMP checksum
+      icmp->checksum = IPChecksum::checksum(b + sizeof(IPv4Header),
+					    sizeof(ICMPv4) - sizeof(IPv4Header) + data_size);
+
+      //std::cout << dump_hex(buf);
+    }
+
+    // assumes that buf is a validated ECHO_REQUEST
+    inline void generate_echo_reply(Buffer& buf,
+				    std::string* log_info)
+    {
+      if (buf.size() < sizeof(ICMPv4))
+	{
+	  if (log_info)
+	    *log_info = "Invalid ECHO4_REQUEST";
+	  return;
+	}
+
+      ICMPv4* icmp = (ICMPv4*) buf.c_data();
+      std::swap(icmp->head.saddr, icmp->head.daddr);
+      const std::uint16_t old_type_code = icmp->type_code;
+      icmp->type = ICMPv4::ECHO_REPLY;
+      icmp->checksum = IPChecksum::cfold(IPChecksum::diff2(old_type_code, icmp->type_code, IPChecksum::cunfold(icmp->checksum)));
+
+      if (log_info)
+	*log_info = "ECHO4_REPLY size=" + std::to_string(buf.size()) + ' ' + IPv4::Addr::from_uint32_net(icmp->head.saddr).to_string() + " -> " + IPv4::Addr::from_uint32_net(icmp->head.daddr).to_string();
+    }
+  }
+}