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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 || _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 || _BYTE_ORDER == _BIG_ENDIAN
77 unsigned int version:4 GNUNET_PACKED;
78 unsigned int header_length:4 GNUNET_PACKED;
80 #error byteorder undefined
85 * Length of the packet, including this header.
87 uint16_t total_length GNUNET_PACKED;
90 * Unique random ID for matching up fragments.
92 uint16_t identification GNUNET_PACKED;
94 unsigned int flags:3 GNUNET_PACKED;
96 unsigned int fragmentation_offset:13 GNUNET_PACKED;
99 * How many more hops can this packet be forwarded?
104 * L4-protocol, for example, IPPROTO_UDP or IPPROTO_TCP.
111 uint16_t checksum GNUNET_PACKED;
114 * Origin of the packet.
116 struct in_addr source_address GNUNET_PACKED;
119 * Destination of the packet.
121 struct in_addr destination_address GNUNET_PACKED;
126 * Standard IPv6 header.
128 struct GNUNET_TUN_IPv6Header
130 #if __BYTE_ORDER == __LITTLE_ENDIAN || _BYTE_ORDER == _LITTLE_ENDIAN
131 unsigned int traffic_class_h:4 GNUNET_PACKED;
132 unsigned int version:4 GNUNET_PACKED;
133 unsigned int traffic_class_l:4 GNUNET_PACKED;
134 unsigned int flow_label:20 GNUNET_PACKED;
135 #elif __BYTE_ORDER == __BIG_ENDIAN || _BYTE_ORDER == _BIG_ENDIAN
136 unsigned int version:4 GNUNET_PACKED;
137 unsigned int traffic_class:8 GNUNET_PACKED;
138 unsigned int flow_label:20 GNUNET_PACKED;
140 #error byteorder undefined
143 * Length of the payload, excluding this header.
145 uint16_t payload_length GNUNET_PACKED;
148 * For example, IPPROTO_UDP or IPPROTO_TCP.
153 * How many more hops can this packet be forwarded?
158 * Origin of the packet.
160 struct in6_addr source_address GNUNET_PACKED;
163 * Destination of the packet.
165 struct in6_addr destination_address GNUNET_PACKED;
172 struct GNUNET_TUN_TcpHeader
174 uint16_t source_port GNUNET_PACKED;
175 uint16_t destination_port GNUNET_PACKED;
180 uint32_t seq GNUNET_PACKED;
183 * Acknowledgement number.
185 uint32_t ack GNUNET_PACKED;
186 #if __BYTE_ORDER == __LITTLE_ENDIAN
188 * Reserved. Must be zero.
190 unsigned int reserved : 4 GNUNET_PACKED;
192 * Number of 32-bit words in TCP header.
194 unsigned int off : 4 GNUNET_PACKED;
195 #elif __BYTE_ORDER == __BIG_ENDIAN
197 * Number of 32-bit words in TCP header.
199 unsigned int off : 4 GNUNET_PACKED;
201 * Reserved. Must be zero.
203 unsigned int reserved : 4 GNUNET_PACKED;
207 * Flags (SYN, FIN, ACK, etc.)
214 uint16_t window_size GNUNET_PACKED;
219 uint16_t crc GNUNET_PACKED;
224 uint16_t urgent_pointer GNUNET_PACKED;
231 struct GNUNET_TUN_UdpHeader
233 uint16_t source_port GNUNET_PACKED;
234 uint16_t destination_port GNUNET_PACKED;
235 uint16_t len GNUNET_PACKED;
236 uint16_t crc GNUNET_PACKED;
243 struct GNUNET_TUN_DnsHeader
245 uint16_t id GNUNET_PACKED;
246 uint16_t flags GNUNET_PACKED;
247 uint16_t qdcount GNUNET_PACKED;
248 uint16_t ancount GNUNET_PACKED;
249 uint16_t nscount GNUNET_PACKED;
250 uint16_t arcount GNUNET_PACKED;
253 #define GNUNET_TUN_ICMPTYPE_ECHO_REPLY 0
254 #define GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE 3
255 #define GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH 4
256 #define GNUNET_TUN_ICMPTYPE_REDIRECT_MESSAGE 5
257 #define GNUNET_TUN_ICMPTYPE_ECHO_REQUEST 8
258 #define GNUNET_TUN_ICMPTYPE_ROUTER_ADVERTISEMENT 9
259 #define GNUNET_TUN_ICMPTYPE_ROUTER_SOLICITATION 10
260 #define GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED 11
262 #define GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE 1
263 #define GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG 2
264 #define GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED 3
265 #define GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM 4
266 #define GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST 128
267 #define GNUNET_TUN_ICMPTYPE6_ECHO_REPLY 129
273 struct GNUNET_TUN_IcmpHeader {
276 uint16_t crc GNUNET_PACKED;
280 * ICMP Echo (request/reply)
283 uint16_t identifier GNUNET_PACKED;
284 uint16_t sequence_number GNUNET_PACKED;
288 * ICMP Destination Unreachable (RFC 1191)
291 uint16_t empty GNUNET_PACKED;
292 uint16_t next_hop_mtu GNUNET_PACKED;
293 /* followed by original IP header + first 8 bytes of original IP datagram */
294 } destination_unreachable;
299 struct in_addr redirect_gateway_address GNUNET_PACKED;
302 * MTU for packets that are too big (IPv6).
304 uint32_t packet_too_big_mtu GNUNET_PACKED;
311 GNUNET_NETWORK_STRUCT_END
315 * Initialize an IPv4 header.
317 * @param ip header to initialize
318 * @param protocol protocol to use (i.e. IPPROTO_UDP)
319 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
320 * @param src source IP address to use
321 * @param dst destination IP address to use
324 GNUNET_TUN_initialize_ipv4_header (struct GNUNET_TUN_IPv4Header *ip,
326 uint16_t payload_length,
327 const struct in_addr *src,
328 const struct in_addr *dst);
332 * Initialize an IPv6 header.
334 * @param ip header to initialize
335 * @param protocol protocol to use (i.e. IPPROTO_UDP)
336 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
337 * @param src source IP address to use
338 * @param dst destination IP address to use
341 GNUNET_TUN_initialize_ipv6_header (struct GNUNET_TUN_IPv6Header *ip,
343 uint16_t payload_length,
344 const struct in6_addr *src,
345 const struct in6_addr *dst);
348 * Calculate IPv4 TCP checksum.
350 * @param ip ipv4 header fully initialized
351 * @param tcp TCP header (initialized except for CRC)
352 * @param payload the TCP payload
353 * @param payload_length number of bytes of TCP payload
356 GNUNET_TUN_calculate_tcp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
357 struct GNUNET_TUN_TcpHeader *tcp,
359 uint16_t payload_length);
362 * Calculate IPv6 TCP checksum.
364 * @param ip ipv6 header fully initialized
365 * @param tcp TCP header (initialized except for CRC)
366 * @param payload the TCP payload
367 * @param payload_length number of bytes of TCP payload
370 GNUNET_TUN_calculate_tcp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
371 struct GNUNET_TUN_TcpHeader *tcp,
373 uint16_t payload_length);
376 * Calculate IPv4 UDP checksum.
378 * @param ip ipv4 header fully initialized
379 * @param udp UDP header (initialized except for CRC)
380 * @param payload the UDP payload
381 * @param payload_length number of bytes of UDP payload
384 GNUNET_TUN_calculate_udp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
385 struct GNUNET_TUN_UdpHeader *udp,
387 uint16_t payload_length);
391 * Calculate IPv6 UDP checksum.
393 * @param ip ipv6 header fully initialized
394 * @param udp UDP header (initialized except for CRC)
395 * @param payload the UDP payload
396 * @param payload_length number of bytes of UDP payload
399 GNUNET_TUN_calculate_udp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
400 struct GNUNET_TUN_UdpHeader *udp,
402 uint16_t payload_length);
406 * Calculate ICMP checksum.
408 * @param icmp IMCP header (initialized except for CRC)
409 * @param payload the ICMP payload
410 * @param payload_length number of bytes of ICMP payload
413 GNUNET_TUN_calculate_icmp_checksum (struct GNUNET_TUN_IcmpHeader *icmp,
415 uint16_t payload_length);