mirror of
https://github.com/OpenVPN/openvpn3.git
synced 2024-09-20 12:12:15 +02:00
c93af60a77
Signed-off-by: James Yonan <james@openvpn.net> Signed-off-by: Lev Stipakov <lev@openvpn.net>
98 lines
3.0 KiB
C++
98 lines
3.0 KiB
C++
// OpenVPN
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//
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// Copyright (C) 2012-2017 OpenVPN Technologies, Inc.
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// All rights reserved.
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#pragma once
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#include <string>
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#include <cstring>
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#include <utility>
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#include <openvpn/common/size.hpp>
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#include <openvpn/common/socktypes.hpp>
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#include <openvpn/buffer/buffer.hpp>
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#include <openvpn/addr/ipv4.hpp>
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#include <openvpn/ip/ipcommon.hpp>
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#include <openvpn/ip/icmp4.hpp>
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#include <openvpn/ip/csum.hpp>
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namespace openvpn {
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namespace Ping4 {
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inline void generate_echo_request(Buffer& buf,
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const IPv4::Addr& src,
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const IPv4::Addr& dest,
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const void *extra_data,
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const size_t extra_data_size,
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const unsigned int id,
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const unsigned int seq_num,
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const size_t total_size,
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std::string* log_info)
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{
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const unsigned int data_size = std::max(int(extra_data_size), int(total_size) - int(sizeof(ICMPv4)));
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if (log_info)
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*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);
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std::uint8_t *b = buf.write_alloc(sizeof(ICMPv4) + data_size);
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ICMPv4 *icmp = (ICMPv4 *)b;
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// IP Header
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icmp->head.version_len = IPv4Header::ver_len(4, sizeof(IPv4Header));
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icmp->head.tos = 0;
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icmp->head.tot_len = htons(sizeof(ICMPv4) + data_size);
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icmp->head.id = 0;
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icmp->head.frag_off = 0;
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icmp->head.ttl = 64;
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icmp->head.protocol = IPCommon::ICMPv4;
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icmp->head.check = 0;
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icmp->head.saddr = src.to_uint32_net();
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icmp->head.daddr = dest.to_uint32_net();
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icmp->head.check = IPChecksum::checksum(b, sizeof(IPv4Header));
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// ICMP header
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icmp->type = ICMPv4::ECHO_REQUEST;
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icmp->code = 0;
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icmp->checksum = 0;
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icmp->id = ntohs(id);
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icmp->seq_num = ntohs(seq_num);
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// Data
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std::uint8_t *data = b + sizeof(ICMPv4);
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for (size_t i = 0; i < data_size; ++i)
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data[i] = (std::uint8_t)i;
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// Extra data
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std::memcpy(data, extra_data, extra_data_size);
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// ICMP checksum
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icmp->checksum = IPChecksum::checksum(b + sizeof(IPv4Header),
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sizeof(ICMPv4) - sizeof(IPv4Header) + data_size);
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//std::cout << dump_hex(buf);
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}
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// assumes that buf is a validated ECHO_REQUEST
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inline void generate_echo_reply(Buffer& buf,
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std::string* log_info)
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{
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if (buf.size() < sizeof(ICMPv4))
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{
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if (log_info)
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*log_info = "Invalid ECHO4_REQUEST";
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return;
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}
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ICMPv4* icmp = (ICMPv4*) buf.c_data();
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std::swap(icmp->head.saddr, icmp->head.daddr);
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const std::uint16_t old_type_code = icmp->type_code;
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icmp->type = ICMPv4::ECHO_REPLY;
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icmp->checksum = IPChecksum::cfold(IPChecksum::diff2(old_type_code, icmp->type_code, IPChecksum::cunfold(icmp->checksum)));
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if (log_info)
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*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();
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}
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}
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}
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