2 This file is part of GNUnet.
3 (C) 2010, 2011, 2012 Christian Grothoff
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file include/gnunet_tun_lib.h
23 * @brief standard TCP/IP network structs and IP checksum calculations for TUN interaction
24 * @author Philipp Toelke
25 * @author Christian Grothoff
27 #ifndef GNUNET_TUN_LIB_H
28 #define GNUNET_TUN_LIB_H
30 #include "gnunet_util_lib.h"
33 /* see http://www.iana.org/assignments/ethernet-numbers */
38 #define ETH_P_IPV4 0x0800
45 #define ETH_P_IPV6 0x86DD
49 GNUNET_NETWORK_STRUCT_BEGIN
52 * Header from Linux TUN interface.
54 struct GNUNET_TUN_Layer2PacketHeader
57 * Some flags (unused).
59 uint16_t flags GNUNET_PACKED;
62 * Here we get an ETH_P_-number.
64 uint16_t proto GNUNET_PACKED;
69 * Standard IPv4 header.
71 struct GNUNET_TUN_IPv4Header
73 #if __BYTE_ORDER == __LITTLE_ENDIAN
74 unsigned int header_length:4 GNUNET_PACKED;
75 unsigned int version:4 GNUNET_PACKED;
76 #elif __BYTE_ORDER == __BIG_ENDIAN
77 unsigned int version:4 GNUNET_PACKED;
78 unsigned int header_length:4 GNUNET_PACKED;
83 * Length of the packet, including this header.
85 uint16_t total_length GNUNET_PACKED;
88 * Unique random ID for matching up fragments.
90 uint16_t identification GNUNET_PACKED;
92 unsigned int flags:3 GNUNET_PACKED;
94 unsigned int fragmentation_offset:13 GNUNET_PACKED;
97 * How many more hops can this packet be forwarded?
102 * L4-protocol, for example, IPPROTO_UDP or IPPROTO_TCP.
109 uint16_t checksum GNUNET_PACKED;
112 * Origin of the packet.
114 struct in_addr source_address GNUNET_PACKED;
117 * Destination of the packet.
119 struct in_addr destination_address GNUNET_PACKED;
124 * Standard IPv6 header.
126 struct GNUNET_TUN_IPv6Header
128 #if __BYTE_ORDER == __LITTLE_ENDIAN
129 unsigned int traffic_class_h:4 GNUNET_PACKED;
130 unsigned int version:4 GNUNET_PACKED;
131 unsigned int traffic_class_l:4 GNUNET_PACKED;
132 unsigned int flow_label:20 GNUNET_PACKED;
133 #elif __BYTE_ORDER == __BIG_ENDIAN
134 unsigned int version:4 GNUNET_PACKED;
135 unsigned int traffic_class:8 GNUNET_PACKED;
136 unsigned int flow_label:20 GNUNET_PACKED;
139 * Length of the payload, excluding this header.
141 uint16_t payload_length GNUNET_PACKED;
144 * For example, IPPROTO_UDP or IPPROTO_TCP.
149 * How many more hops can this packet be forwarded?
154 * Origin of the packet.
156 struct in6_addr source_address GNUNET_PACKED;
159 * Destination of the packet.
161 struct in6_addr destination_address GNUNET_PACKED;
168 struct GNUNET_TUN_TcpHeader
170 uint16_t source_port GNUNET_PACKED;
171 uint16_t destination_port GNUNET_PACKED;
176 uint32_t seq GNUNET_PACKED;
179 * Acknowledgement number.
181 uint32_t ack GNUNET_PACKED;
182 #if __BYTE_ORDER == __LITTLE_ENDIAN
184 * Reserved. Must be zero.
186 unsigned int reserved : 4 GNUNET_PACKED;
188 * Number of 32-bit words in TCP header.
190 unsigned int off : 4 GNUNET_PACKED;
191 #elif __BYTE_ORDER == __BIG_ENDIAN
193 * Number of 32-bit words in TCP header.
195 unsigned int off : 4 GNUNET_PACKED;
197 * Reserved. Must be zero.
199 unsigned int reserved : 4 GNUNET_PACKED;
203 * Flags (SYN, FIN, ACK, etc.)
210 uint16_t window_size GNUNET_PACKED;
215 uint16_t crc GNUNET_PACKED;
220 uint16_t urgent_pointer GNUNET_PACKED;
227 struct GNUNET_TUN_UdpHeader
229 uint16_t source_port GNUNET_PACKED;
230 uint16_t destination_port GNUNET_PACKED;
231 uint16_t len GNUNET_PACKED;
232 uint16_t crc GNUNET_PACKED;
239 struct GNUNET_TUN_DnsHeader
241 uint16_t id GNUNET_PACKED;
242 uint16_t flags GNUNET_PACKED;
243 uint16_t qdcount GNUNET_PACKED;
244 uint16_t ancount GNUNET_PACKED;
245 uint16_t nscount GNUNET_PACKED;
246 uint16_t arcount GNUNET_PACKED;
249 #define GNUNET_TUN_ICMPTYPE_ECHO_REPLY 0
250 #define GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE 3
251 #define GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH 4
252 #define GNUNET_TUN_ICMPTYPE_REDIRECT_MESSAGE 5
253 #define GNUNET_TUN_ICMPTYPE_ECHO_REQUEST 8
254 #define GNUNET_TUN_ICMPTYPE_ROUTER_ADVERTISEMENT 9
255 #define GNUNET_TUN_ICMPTYPE_ROUTER_SOLICITATION 10
256 #define GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED 11
258 #define GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE 1
259 #define GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG 2
260 #define GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED 3
261 #define GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM 4
262 #define GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST 128
263 #define GNUNET_TUN_ICMPTYPE6_ECHO_REPLY 129
269 struct GNUNET_TUN_IcmpHeader {
272 uint16_t crc GNUNET_PACKED;
276 * ICMP Echo (request/reply)
279 uint16_t identifier GNUNET_PACKED;
280 uint16_t sequence_number GNUNET_PACKED;
284 * ICMP Destination Unreachable (RFC 1191)
287 uint16_t empty GNUNET_PACKED;
288 uint16_t next_hop_mtu GNUNET_PACKED;
289 /* followed by original IP header + first 8 bytes of original IP datagram */
290 } destination_unreachable;
295 struct in_addr redirect_gateway_address GNUNET_PACKED;
298 * MTU for packets that are too big (IPv6).
300 uint32_t packet_too_big_mtu GNUNET_PACKED;
307 GNUNET_NETWORK_STRUCT_END
311 * Initialize an IPv4 header.
313 * @param ip header to initialize
314 * @param protocol protocol to use (i.e. IPPROTO_UDP)
315 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
316 * @param src source IP address to use
317 * @param dst destination IP address to use
320 GNUNET_TUN_initialize_ipv4_header (struct GNUNET_TUN_IPv4Header *ip,
322 uint16_t payload_length,
323 const struct in_addr *src,
324 const struct in_addr *dst);
328 * Initialize an IPv6 header.
330 * @param ip header to initialize
331 * @param protocol protocol to use (i.e. IPPROTO_UDP)
332 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
333 * @param src source IP address to use
334 * @param dst destination IP address to use
337 GNUNET_TUN_initialize_ipv6_header (struct GNUNET_TUN_IPv6Header *ip,
339 uint16_t payload_length,
340 const struct in6_addr *src,
341 const struct in6_addr *dst);
344 * Calculate IPv4 TCP checksum.
346 * @param ip ipv4 header fully initialized
347 * @param tcp TCP header (initialized except for CRC)
348 * @param payload the TCP payload
349 * @param payload_length number of bytes of TCP payload
352 GNUNET_TUN_calculate_tcp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
353 struct GNUNET_TUN_TcpHeader *tcp,
355 uint16_t payload_length);
358 * Calculate IPv6 TCP checksum.
360 * @param ip ipv6 header fully initialized
361 * @param tcp TCP header (initialized except for CRC)
362 * @param payload the TCP payload
363 * @param payload_length number of bytes of TCP payload
366 GNUNET_TUN_calculate_tcp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
367 struct GNUNET_TUN_TcpHeader *tcp,
369 uint16_t payload_length);
372 * Calculate IPv4 UDP checksum.
374 * @param ip ipv4 header fully initialized
375 * @param udp UDP header (initialized except for CRC)
376 * @param payload the UDP payload
377 * @param payload_length number of bytes of UDP payload
380 GNUNET_TUN_calculate_udp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
381 struct GNUNET_TUN_UdpHeader *udp,
383 uint16_t payload_length);
387 * Calculate IPv6 UDP checksum.
389 * @param ip ipv6 header fully initialized
390 * @param udp UDP header (initialized except for CRC)
391 * @param payload the UDP payload
392 * @param payload_length number of bytes of UDP payload
395 GNUNET_TUN_calculate_udp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
396 struct GNUNET_TUN_UdpHeader *udp,
398 uint16_t payload_length);
402 * Calculate ICMP checksum.
404 * @param icmp IMCP header (initialized except for CRC)
405 * @param payload the ICMP payload
406 * @param payload_length number of bytes of ICMP payload
409 GNUNET_TUN_calculate_icmp_checksum (struct GNUNET_TUN_IcmpHeader *icmp,
411 uint16_t payload_length);