4 * The secure anycast tunneling protocol (satp) defines a protocol used
5 * for communication between any combination of unicast and anycast
6 * tunnel endpoints. It has less protocol overhead than IPSec in Tunnel
7 * mode and allows tunneling of every ETHER TYPE protocol (e.g.
8 * ethernet, ip, arp ...). satp directly includes cryptography and
9 * message authentication based on the methodes used by SRTP. It is
10 * intended to deliver a generic, scaleable and secure solution for
11 * tunneling and relaying of packets of any protocol.
14 * Copyright (C) 2007-2009 Othmar Gsenger, Erwin Nindl,
15 * Christian Pointner <satp@wirdorange.org>
17 * This file is part of Anytun.
19 * Anytun is free software: you can redistribute it and/or modify
20 * it under the terms of the GNU General Public License as published by
21 * the Free Software Foundation, either version 3 of the License, or
24 * Anytun is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
29 * You should have received a copy of the GNU General Public License
30 * along with anytun. If not, see <http://www.gnu.org/licenses/>.
33 #include "threadUtils.hpp"
34 #include "datatypes.h"
36 #include "seqWindow.h"
38 SeqWindowElement::SeqWindowElement()
45 SeqWindowElement::~SeqWindowElement()
51 void SeqWindowElement::init(window_size_t w, seq_nr_t m)
55 window_ = new u_int8_t[w];
56 memset(window_, 0, w);
62 SeqWindow::SeqWindow(window_size_t w) : window_size_(w)
66 SeqWindow::~SeqWindow()
70 bool SeqWindow::checkAndAdd(sender_id_t sender, seq_nr_t seq_nr)
76 SenderMap::iterator s = sender_.find(sender);
77 if(s == sender_.end()) {
78 sender_[sender].init(window_size_, seq_nr);
83 if(s->second.max_ < window_size_) {
84 s->second.max_ += SEQ_NR_MAX/2;
85 seq_nr += SEQ_NR_MAX/2;
88 else if(s->second.max_ > (SEQ_NR_MAX - window_size_)) {
89 s->second.max_ -= SEQ_NR_MAX/2;
90 seq_nr -= SEQ_NR_MAX/2;
94 seq_nr_t min = s->second.max_ - window_size_ + 1;
95 if(seq_nr < min || seq_nr == s->second.max_) {
97 s->second.max_ -= SEQ_NR_MAX/2;
99 s->second.max_ += SEQ_NR_MAX/2;
103 if(seq_nr > s->second.max_) {
104 seq_nr_t diff = seq_nr - s->second.max_;
105 if(diff >= window_size_)
108 window_size_t new_pos = s->second.pos_ + diff;
110 if(new_pos >= window_size_) {
111 new_pos -= window_size_;
113 if(s->second.pos_ < window_size_ - 1)
114 memset(&(s->second.window_[s->second.pos_ + 1]), 0, window_size_ - s->second.pos_ - 1);
116 memset(s->second.window_, 0, new_pos);
119 memset(&(s->second.window_[s->second.pos_ + 1]), 0, diff);
121 s->second.pos_ = new_pos;
122 s->second.window_[s->second.pos_] = 1;
123 s->second.max_ = seq_nr;
126 s->second.max_ -= SEQ_NR_MAX/2;
127 else if(shifted == 2)
128 s->second.max_ += SEQ_NR_MAX/2;
133 seq_nr_t diff = s->second.max_ - seq_nr;
134 window_size_t pos = diff > s->second.pos_ ? s->second.pos_ + window_size_ : s->second.pos_;
138 s->second.max_ -= SEQ_NR_MAX/2;
139 else if(shifted == 2)
140 s->second.max_ += SEQ_NR_MAX/2;
142 int ret = s->second.window_[pos];
143 s->second.window_[pos] = 1;
151 void SeqWindow::clear(sender_id_t sender)
154 sender_.erase(sender);
157 void SeqWindow::clear()