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3 (C) 2010, 2011, 2012 Christian Grothoff
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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_h:4 GNUNET_PACKED;
136 unsigned int traffic_class_l:4 GNUNET_PACKED;
137 unsigned int flow_label:20 GNUNET_PACKED;
140 * Length of the payload, excluding this header.
142 uint16_t payload_length GNUNET_PACKED;
145 * For example, IPPROTO_UDP or IPPROTO_TCP.
150 * How many more hops can this packet be forwarded?
155 * Origin of the packet.
157 struct in6_addr source_address GNUNET_PACKED;
160 * Destination of the packet.
162 struct in6_addr destination_address GNUNET_PACKED;
169 struct GNUNET_TUN_TcpHeader
171 uint16_t source_port GNUNET_PACKED;
172 uint16_t destination_port GNUNET_PACKED;
177 uint32_t seq GNUNET_PACKED;
180 * Acknowledgement number.
182 uint32_t ack GNUNET_PACKED;
183 #if __BYTE_ORDER == __LITTLE_ENDIAN
187 unsigned int reserved : 4 GNUNET_PACKED;
189 * Number of 32-bit words in TCP header.
191 unsigned int off : 4 GNUNET_PACKED;
192 #elif __BYTE_ORDER == __BIG_ENDIAN
194 * Number of 32-bit words in TCP header.
196 unsigned int off : 4 GNUNET_PACKED;
200 unsigned int reserved : 4 GNUNET_PACKED;
207 uint16_t window_size GNUNET_PACKED;
212 uint16_t crc GNUNET_PACKED;
217 uint16_t urgent_pointer GNUNET_PACKED;
224 struct GNUNET_TUN_UdpHeader
226 uint16_t source_port GNUNET_PACKED;
227 uint16_t destination_port GNUNET_PACKED;
228 uint16_t len GNUNET_PACKED;
229 uint16_t crc GNUNET_PACKED;
236 struct GNUNET_TUN_DnsHeader
238 uint16_t id GNUNET_PACKED;
239 uint16_t flags GNUNET_PACKED;
240 uint16_t qdcount GNUNET_PACKED;
241 uint16_t ancount GNUNET_PACKED;
242 uint16_t nscount GNUNET_PACKED;
243 uint16_t arcount GNUNET_PACKED;
246 #define GNUNET_TUN_ICMPTYPE_ECHO_REPLY 0
247 #define GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE 3
248 #define GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH 4
249 #define GNUNET_TUN_ICMPTYPE_REDIRECT_MESSAGE 5
250 #define GNUNET_TUN_ICMPTYPE_ECHO_REQUEST 8
251 #define GNUNET_TUN_ICMPTYPE_ROUTER_ADVERTISEMENT 9
252 #define GNUNET_TUN_ICMPTYPE_ROUTER_SOLICITATION 10
253 #define GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED 11
255 #define GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE 1
256 #define GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG 2
257 #define GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED 3
258 #define GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM 4
259 #define GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST 128
260 #define GNUNET_TUN_ICMPTYPE6_ECHO_REPLY 129
266 struct GNUNET_TUN_IcmpHeader {
269 uint16_t crc GNUNET_PACKED;
273 * ICMP Echo (request/reply)
276 uint16_t identifier GNUNET_PACKED;
277 uint16_t sequence_number GNUNET_PACKED;
281 * ICMP Destination Unreachable (RFC 1191)
284 uint16_t empty GNUNET_PACKED;
285 uint16_t next_hop_mtu GNUNET_PACKED;
286 /* followed by original IP header + first 8 bytes of original IP datagram */
287 } destination_unreachable;
292 struct in_addr redirect_gateway_address GNUNET_PACKED;
295 * MTU for packets that are too big (IPv6).
297 uint32_t packet_too_big_mtu GNUNET_PACKED;
304 GNUNET_NETWORK_STRUCT_END
308 * Initialize an IPv4 header.
310 * @param ip header to initialize
311 * @param protocol protocol to use (i.e. IPPROTO_UDP)
312 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
313 * @param src source IP address to use
314 * @param dst destination IP address to use
317 GNUNET_TUN_initialize_ipv4_header (struct GNUNET_TUN_IPv4Header *ip,
319 uint16_t payload_length,
320 const struct in_addr *src,
321 const struct in_addr *dst);
325 * Initialize an IPv6 header.
327 * @param ip header to initialize
328 * @param protocol protocol to use (i.e. IPPROTO_UDP)
329 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
330 * @param src source IP address to use
331 * @param dst destination IP address to use
334 GNUNET_TUN_initialize_ipv6_header (struct GNUNET_TUN_IPv6Header *ip,
336 uint16_t payload_length,
337 const struct in6_addr *src,
338 const struct in6_addr *dst);
341 * Calculate IPv4 TCP checksum.
343 * @param ip ipv4 header fully initialized
344 * @param tcp TCP header (initialized except for CRC)
345 * @param payload the TCP payload
346 * @param payload_length number of bytes of TCP payload
349 GNUNET_TUN_calculate_tcp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
350 struct GNUNET_TUN_TcpHeader *tcp,
352 uint16_t payload_length);
355 * Calculate IPv6 TCP checksum.
357 * @param ip ipv6 header fully initialized
358 * @param tcp TCP header (initialized except for CRC)
359 * @param payload the TCP payload
360 * @param payload_length number of bytes of TCP payload
363 GNUNET_TUN_calculate_tcp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
364 struct GNUNET_TUN_TcpHeader *tcp,
366 uint16_t payload_length);
369 * Calculate IPv4 UDP checksum.
371 * @param ip ipv4 header fully initialized
372 * @param udp UDP header (initialized except for CRC)
373 * @param payload the UDP payload
374 * @param payload_length number of bytes of UDP payload
377 GNUNET_TUN_calculate_udp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
378 struct GNUNET_TUN_UdpHeader *udp,
380 uint16_t payload_length);
384 * Calculate IPv6 UDP checksum.
386 * @param ip ipv6 header fully initialized
387 * @param udp UDP header (initialized except for CRC)
388 * @param payload the UDP payload
389 * @param payload_length number of bytes of UDP payload
392 GNUNET_TUN_calculate_udp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
393 struct GNUNET_TUN_UdpHeader *udp,
395 uint16_t payload_length);
399 * Calculate ICMP checksum.
401 * @param icmp IMCP header (initialized except for CRC)
402 * @param payload the ICMP payload
403 * @param payload_length number of bytes of ICMP payload
406 GNUNET_TUN_calculate_icmp_checksum (struct GNUNET_TUN_IcmpHeader *icmp,
408 uint16_t payload_length);