diff options
Diffstat (limited to 'packet.cpp')
| -rw-r--r-- | packet.cpp | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/packet.cpp b/packet.cpp new file mode 100644 index 0000000..dceceb5 --- /dev/null +++ b/packet.cpp @@ -0,0 +1,272 @@ +/* + * anytun + * + * The secure anycast tunneling protocol (satp) defines a protocol used + * for communication between any combination of unicast and anycast + * tunnel endpoints. It has less protocol overhead than IPSec in Tunnel + * mode and allows tunneling of every ETHER TYPE protocol (e.g. + * ethernet, ip, arp ...). satp directly includes cryptography and + * message authentication based on the methodes used by SRTP. It is + * intended to deliver a generic, scaleable and secure solution for + * tunneling and relaying of packets of any protocol. + * + * + * Copyright (C) 2007 anytun.org <satp@wirdorange.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program (see the file COPYING included with this + * distribution); if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <stdexcept> +#include <arpa/inet.h> + +#include "datatypes.h" + +#include "packet.h" + +Packet::Packet() +{ + has_header_ = false; + has_payload_type_ = false; + has_auth_tag_ = false; +} + +Packet::Packet(u_int32_t length) : Buffer(length) +{ + has_header_ = false; + has_payload_type_ = false; + has_auth_tag_ = false; +} + +Packet::Packet(const Buffer &src) : Buffer(src) +{ + has_header_ = false; + has_payload_type_ = false; + has_auth_tag_ = false; +} + +bool Packet::hasHeader() const +{ + return has_header_; +} + +Packet& Packet::withHeader(bool b) +{ + if(b && length_ >= sizeof(struct HeaderStruct)) + has_header_ = true; + else + has_header_ = false; + + return *this; +} + +seq_nr_t Packet::getSeqNr() const +{ + if(!has_header_) + return 0; + + struct HeaderStruct* header; + header = reinterpret_cast<struct HeaderStruct*>(buf_); + return SEQ_NR_T_NTOH(header->seq_nr); +} + +sender_id_t Packet::getSenderId() const +{ + if(!has_header_) + return 0; + + struct HeaderStruct* header; + header = reinterpret_cast<struct HeaderStruct*>(buf_); + return SENDER_ID_T_NTOH(header->sender_id); +} + +Packet& Packet::addHeader(seq_nr_t seq_nr, sender_id_t sender_id) +{ + if(!has_header_) + { + if(sizeof(struct HeaderStruct) > resizeFront(length_ + sizeof(struct HeaderStruct))) + return *this; + + has_header_ = true; + } + struct HeaderStruct* header; + header = reinterpret_cast<struct HeaderStruct*>(buf_); + header->seq_nr = SEQ_NR_T_HTON(seq_nr); + header->sender_id = SENDER_ID_T_HTON(sender_id); + return *this; +} + +Packet& Packet::removeHeader() +{ + if(!has_header_) + return *this; + + if(length_ >= sizeof(struct HeaderStruct)) + resizeFront(length_ - sizeof(struct HeaderStruct)); + + has_header_ = false; + + return *this; +} + +Packet& Packet::setSeqNr(seq_nr_t seq_nr) +{ + if(has_header_) + { + struct HeaderStruct* header; + header = reinterpret_cast<struct HeaderStruct*>(buf_); + header->seq_nr = SEQ_NR_T_HTON(seq_nr); + } + return *this; +} + +Packet& Packet::setSenderId(sender_id_t sender_id) +{ + if(has_header_) + { + struct HeaderStruct* header; + header = reinterpret_cast<struct HeaderStruct*>(buf_); + header->sender_id = SENDER_ID_T_HTON(sender_id); + } + return *this; +} + + + +bool Packet::hasPayloadType() const +{ + return has_payload_type_; +} + +Packet& Packet::withPayloadType(bool b) +{ + if(b && length_ >= sizeof(payload_type_t)) + has_payload_type_ = true; + else + has_payload_type_ = false; + + return *this; +} + +payload_type_t Packet::getPayloadType() const +{ + if(!has_payload_type_) + return 0; + + if((!has_auth_tag_ && length_ < sizeof(payload_type_t)) || + (has_auth_tag_ && length_ < (sizeof(payload_type_t) + sizeof(auth_tag_t)))) + return 0; + + payload_type_t* payload_type; + + if(!has_auth_tag_) + payload_type = reinterpret_cast<payload_type_t*>(buf_ + length_ - sizeof(payload_type_t)); + else + payload_type = reinterpret_cast<payload_type_t*>(buf_ + length_ - sizeof(payload_type_t) - sizeof(auth_tag_t)); + return PAYLOAD_TYPE_T_NTOH(*payload_type); +} + +Packet& Packet::addPayloadType(payload_type_t payload_type) +{ + if(has_auth_tag_) + throw std::runtime_error("can't add payload_type with existing auth_tag"); + + if(!has_payload_type_) + { + u_int32_t new_length = length_ + sizeof(payload_type_t); + if(new_length > resizeBack(new_length)) + return *this; + + has_payload_type_ = true; + } + payload_type_t* payload_type_ptr; + payload_type_ptr = reinterpret_cast<payload_type_t*>(buf_ + length_ - sizeof(payload_type_t)); + *payload_type_ptr = PAYLOAD_TYPE_T_HTON(payload_type); + return *this; +} + +Packet& Packet::removePayloadType() +{ + if(has_auth_tag_) + throw std::runtime_error("can't remove payload_type with existing auth_tag"); + + if(!has_payload_type_) + return *this; + + if(length_ >= sizeof(payload_type_t)) + resizeBack(length_ - sizeof(payload_type_t)); + + has_payload_type_ = false; + + return *this; +} + + + +bool Packet::hasAuthTag() const +{ + return has_auth_tag_; +} + +Packet& Packet::withAuthTag(bool b) +{ + if(b && length_ >= sizeof(auth_tag_t)) + has_auth_tag_ = true; + else + has_auth_tag_ = false; + + return *this; +} + +auth_tag_t Packet::getAuthTag() const +{ + if(!has_auth_tag_) + return 0; + + if(length_ < sizeof(auth_tag_t)) + return 0; + + auth_tag_t* auth_tag; + auth_tag = reinterpret_cast<auth_tag_t*>(buf_ + length_ - sizeof(auth_tag_t)); + return AUTH_TAG_T_NTOH(*auth_tag); +} + +Packet& Packet::addAuthTag(auth_tag_t auth_tag) +{ + if(!has_auth_tag_) + { + u_int32_t new_length = length_ + sizeof(auth_tag_t); + if(new_length > resizeBack(new_length)) + return *this; + + has_auth_tag_ = true; + } + auth_tag_t* auth_tag_ptr; + auth_tag_ptr = reinterpret_cast<auth_tag_t*>(buf_ + length_ - sizeof(auth_tag_t)); + *auth_tag_ptr = AUTH_TAG_T_HTON(auth_tag); + return *this; +} + +Packet& Packet::removeAuthTag() +{ + if(!has_auth_tag_) + return *this; + + if(length_ >= sizeof(auth_tag_t)) + resizeBack(length_ - sizeof(auth_tag_t)); + + has_auth_tag_ = false; + + return *this; +} |