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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: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
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;
199 unsigned int reserved : 4 GNUNET_PACKED;
206 uint16_t window_size GNUNET_PACKED;
211 uint16_t crc GNUNET_PACKED;
216 uint16_t urgent_pointer GNUNET_PACKED;
223 struct GNUNET_TUN_UdpHeader
225 uint16_t source_port GNUNET_PACKED;
226 uint16_t destination_port GNUNET_PACKED;
227 uint16_t len GNUNET_PACKED;
228 uint16_t crc GNUNET_PACKED;
235 struct GNUNET_TUN_DnsHeader
237 uint16_t id GNUNET_PACKED;
238 uint16_t flags GNUNET_PACKED;
239 uint16_t qdcount GNUNET_PACKED;
240 uint16_t ancount GNUNET_PACKED;
241 uint16_t nscount GNUNET_PACKED;
242 uint16_t arcount GNUNET_PACKED;
245 #define GNUNET_TUN_ICMPTYPE_ECHO_REPLY 0
246 #define GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE 3
247 #define GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH 4
248 #define GNUNET_TUN_ICMPTYPE_REDIRECT_MESSAGE 5
249 #define GNUNET_TUN_ICMPTYPE_ECHO_REQUEST 8
250 #define GNUNET_TUN_ICMPTYPE_ROUTER_ADVERTISEMENT 9
251 #define GNUNET_TUN_ICMPTYPE_ROUTER_SOLICITATION 10
252 #define GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED 11
254 #define GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE 1
255 #define GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG 2
256 #define GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED 3
257 #define GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM 4
258 #define GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST 128
259 #define GNUNET_TUN_ICMPTYPE6_ECHO_REPLY 129
265 struct GNUNET_TUN_IcmpHeader {
268 uint16_t crc GNUNET_PACKED;
272 * ICMP Echo (request/reply)
275 uint16_t identifier GNUNET_PACKED;
276 uint16_t sequence_number GNUNET_PACKED;
280 * ICMP Destination Unreachable (RFC 1191)
283 uint16_t empty GNUNET_PACKED;
284 uint16_t next_hop_mtu GNUNET_PACKED;
285 /* followed by original IP header + first 8 bytes of original IP datagram */
286 } destination_unreachable;
291 struct in_addr redirect_gateway_address GNUNET_PACKED;
294 * MTU for packets that are too big (IPv6).
296 uint32_t packet_too_big_mtu GNUNET_PACKED;
303 GNUNET_NETWORK_STRUCT_END
307 * Initialize an IPv4 header.
309 * @param ip header to initialize
310 * @param protocol protocol to use (i.e. IPPROTO_UDP)
311 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
312 * @param src source IP address to use
313 * @param dst destination IP address to use
316 GNUNET_TUN_initialize_ipv4_header (struct GNUNET_TUN_IPv4Header *ip,
318 uint16_t payload_length,
319 const struct in_addr *src,
320 const struct in_addr *dst);
324 * Initialize an IPv6 header.
326 * @param ip header to initialize
327 * @param protocol protocol to use (i.e. IPPROTO_UDP)
328 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
329 * @param src source IP address to use
330 * @param dst destination IP address to use
333 GNUNET_TUN_initialize_ipv6_header (struct GNUNET_TUN_IPv6Header *ip,
335 uint16_t payload_length,
336 const struct in6_addr *src,
337 const struct in6_addr *dst);
340 * Calculate IPv4 TCP checksum.
342 * @param ip ipv4 header fully initialized
343 * @param tcp TCP header (initialized except for CRC)
344 * @param payload the TCP payload
345 * @param payload_length number of bytes of TCP payload
348 GNUNET_TUN_calculate_tcp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
349 struct GNUNET_TUN_TcpHeader *tcp,
351 uint16_t payload_length);
354 * Calculate IPv6 TCP checksum.
356 * @param ip ipv6 header fully initialized
357 * @param tcp TCP header (initialized except for CRC)
358 * @param payload the TCP payload
359 * @param payload_length number of bytes of TCP payload
362 GNUNET_TUN_calculate_tcp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
363 struct GNUNET_TUN_TcpHeader *tcp,
365 uint16_t payload_length);
368 * Calculate IPv4 UDP checksum.
370 * @param ip ipv4 header fully initialized
371 * @param udp UDP header (initialized except for CRC)
372 * @param payload the UDP payload
373 * @param payload_length number of bytes of UDP payload
376 GNUNET_TUN_calculate_udp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
377 struct GNUNET_TUN_UdpHeader *udp,
379 uint16_t payload_length);
383 * Calculate IPv6 UDP checksum.
385 * @param ip ipv6 header fully initialized
386 * @param udp UDP header (initialized except for CRC)
387 * @param payload the UDP payload
388 * @param payload_length number of bytes of UDP payload
391 GNUNET_TUN_calculate_udp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
392 struct GNUNET_TUN_UdpHeader *udp,
394 uint16_t payload_length);
398 * Calculate ICMP checksum.
400 * @param icmp IMCP header (initialized except for CRC)
401 * @param payload the ICMP payload
402 * @param payload_length number of bytes of ICMP payload
405 GNUNET_TUN_calculate_icmp_checksum (struct GNUNET_TUN_IcmpHeader *icmp,
407 uint16_t payload_length);