2 This file is part of GNUnet.
3 Copyright (C) 2010-2013 Christian Grothoff
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6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
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11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
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16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 SPDX-License-Identifier: AGPL3.0-or-later
22 * @author Philipp Toelke
23 * @author Christian Grothoff
26 * Standard TCP/IP network structs and IP checksum calculations for TUN interaction
28 * @defgroup tun TUN library
29 * Standard TCP/IP network structs and IP checksum calculations for TUN interaction
32 #ifndef GNUNET_TUN_LIB_H
33 #define GNUNET_TUN_LIB_H
35 #include "gnunet_common.h"
36 #include "gnunet_crypto_lib.h"
39 /* see http://www.iana.org/assignments/ethernet-numbers */
44 #define ETH_P_IPV4 0x0800
51 #define ETH_P_IPV6 0x86DD
56 * Maximum regex string length for use with #GNUNET_TUN_ipv4toregexsearch.
58 * 8 bytes for IPv4, 4 bytes for port, 1 byte for "4", 2 bytes for "-",
59 * one byte for 0-termination.
62 #define GNUNET_TUN_IPV4_REGEXLEN 16
66 * Maximum regex string length for use with #GNUNET_TUN_ipv6toregexsearch
68 * 32 bytes for IPv4, 4 bytes for port, 1 byte for "4", 2 bytes for "-",
69 * one byte for 0-termination.
71 #define GNUNET_TUN_IPV6_REGEXLEN 40
74 GNUNET_NETWORK_STRUCT_BEGIN
77 * Header from Linux TUN interface.
79 struct GNUNET_TUN_Layer2PacketHeader
82 * Some flags (unused).
84 uint16_t flags GNUNET_PACKED;
87 * Here we get an ETH_P_-number.
89 uint16_t proto GNUNET_PACKED;
94 * Standard IPv4 header.
96 struct GNUNET_TUN_IPv4Header
98 #if __BYTE_ORDER == __LITTLE_ENDIAN
99 unsigned int header_length:4 GNUNET_PACKED;
100 unsigned int version:4 GNUNET_PACKED;
101 #elif __BYTE_ORDER == __BIG_ENDIAN
102 unsigned int version:4 GNUNET_PACKED;
103 unsigned int header_length:4 GNUNET_PACKED;
105 #error byteorder undefined
110 * Length of the packet, including this header.
112 uint16_t total_length GNUNET_PACKED;
115 * Unique random ID for matching up fragments.
117 uint16_t identification GNUNET_PACKED;
119 unsigned int flags:3 GNUNET_PACKED;
121 unsigned int fragmentation_offset:13 GNUNET_PACKED;
124 * How many more hops can this packet be forwarded?
129 * L4-protocol, for example, IPPROTO_UDP or IPPROTO_TCP.
136 uint16_t checksum GNUNET_PACKED;
139 * Origin of the packet.
141 struct in_addr source_address GNUNET_PACKED;
144 * Destination of the packet.
146 struct in_addr destination_address GNUNET_PACKED;
147 } GNUNET_GCC_STRUCT_LAYOUT;
151 * Standard IPv6 header.
153 struct GNUNET_TUN_IPv6Header
155 #if __BYTE_ORDER == __LITTLE_ENDIAN
156 unsigned int traffic_class_h:4 GNUNET_PACKED;
157 unsigned int version:4 GNUNET_PACKED;
158 unsigned int traffic_class_l:4 GNUNET_PACKED;
159 unsigned int flow_label:20 GNUNET_PACKED;
160 #elif __BYTE_ORDER == __BIG_ENDIAN
161 unsigned int version:4 GNUNET_PACKED;
162 unsigned int traffic_class:8 GNUNET_PACKED;
163 unsigned int flow_label:20 GNUNET_PACKED;
165 #error byteorder undefined
168 * Length of the payload, excluding this header.
170 uint16_t payload_length GNUNET_PACKED;
173 * For example, IPPROTO_UDP or IPPROTO_TCP.
178 * How many more hops can this packet be forwarded?
183 * Origin of the packet.
185 struct in6_addr source_address GNUNET_PACKED;
188 * Destination of the packet.
190 struct in6_addr destination_address GNUNET_PACKED;
191 } GNUNET_GCC_STRUCT_LAYOUT;
197 #define GNUNET_TUN_TCP_FLAGS_FIN 1
198 #define GNUNET_TUN_TCP_FLAGS_SYN 2
199 #define GNUNET_TUN_TCP_FLAGS_RST 4
200 #define GNUNET_TUN_TCP_FLAGS_PSH 8
201 #define GNUNET_TUN_TCP_FLAGS_ACK 16
202 #define GNUNET_TUN_TCP_FLAGS_URG 32
203 #define GNUNET_TUN_TCP_FLAGS_ECE 64
204 #define GNUNET_TUN_TCP_FLAGS_CWR 128
209 struct GNUNET_TUN_TcpHeader
212 * Source port (in NBO).
214 uint16_t source_port GNUNET_PACKED;
217 * Destination port (in NBO).
219 uint16_t destination_port GNUNET_PACKED;
224 uint32_t seq GNUNET_PACKED;
227 * Acknowledgement number.
229 uint32_t ack GNUNET_PACKED;
230 #if __BYTE_ORDER == __LITTLE_ENDIAN
232 * Reserved. Must be zero.
234 unsigned int reserved : 4 GNUNET_PACKED;
236 * Number of 32-bit words in TCP header.
238 unsigned int off : 4 GNUNET_PACKED;
239 #elif __BYTE_ORDER == __BIG_ENDIAN
241 * Number of 32-bit words in TCP header.
243 unsigned int off : 4 GNUNET_PACKED;
245 * Reserved. Must be zero.
247 unsigned int reserved : 4 GNUNET_PACKED;
249 #error byteorder undefined
253 * Flags (SYN, FIN, ACK, etc.)
260 uint16_t window_size GNUNET_PACKED;
265 uint16_t crc GNUNET_PACKED;
270 uint16_t urgent_pointer GNUNET_PACKED;
271 } GNUNET_GCC_STRUCT_LAYOUT;
277 struct GNUNET_TUN_UdpHeader
280 * Source port (in NBO).
282 uint16_t source_port GNUNET_PACKED;
285 * Destination port (in NBO).
287 uint16_t destination_port GNUNET_PACKED;
290 * Number of bytes of payload.
292 uint16_t len GNUNET_PACKED;
297 uint16_t crc GNUNET_PACKED;
303 * A few common DNS classes (ok, only one is common, but I list a
304 * couple more to make it clear what we're talking about here).
306 #define GNUNET_TUN_DNS_CLASS_INTERNET 1
307 #define GNUNET_TUN_DNS_CLASS_CHAOS 3
308 #define GNUNET_TUN_DNS_CLASS_HESIOD 4
310 #define GNUNET_TUN_DNS_OPCODE_QUERY 0
311 #define GNUNET_TUN_DNS_OPCODE_INVERSE_QUERY 1
312 #define GNUNET_TUN_DNS_OPCODE_STATUS 2
318 #define GNUNET_TUN_DNS_RETURN_CODE_NO_ERROR 0
319 #define GNUNET_TUN_DNS_RETURN_CODE_FORMAT_ERROR 1
320 #define GNUNET_TUN_DNS_RETURN_CODE_SERVER_FAILURE 2
321 #define GNUNET_TUN_DNS_RETURN_CODE_NAME_ERROR 3
322 #define GNUNET_TUN_DNS_RETURN_CODE_NOT_IMPLEMENTED 4
323 #define GNUNET_TUN_DNS_RETURN_CODE_REFUSED 5
328 #define GNUNET_TUN_DNS_RETURN_CODE_YXDOMAIN 6
329 #define GNUNET_TUN_DNS_RETURN_CODE_YXRRSET 7
330 #define GNUNET_TUN_DNS_RETURN_CODE_NXRRSET 8
331 #define GNUNET_TUN_DNS_RETURN_CODE_NOT_AUTH 9
332 #define GNUNET_TUN_DNS_RETURN_CODE_NOT_ZONE 10
336 * DNS flags (largely RFC 1035 / RFC 2136).
338 struct GNUNET_TUN_DnsFlags
340 #if __BYTE_ORDER == __LITTLE_ENDIAN
342 * Set to 1 if recursion is desired (client -> server)
344 unsigned int recursion_desired : 1 GNUNET_PACKED;
347 * Set to 1 if message is truncated
349 unsigned int message_truncated : 1 GNUNET_PACKED;
352 * Set to 1 if this is an authoritative answer
354 unsigned int authoritative_answer : 1 GNUNET_PACKED;
357 * See GNUNET_TUN_DNS_OPCODE_ defines.
359 unsigned int opcode : 4 GNUNET_PACKED;
362 * query:0, response:1
364 unsigned int query_or_response : 1 GNUNET_PACKED;
367 * See GNUNET_TUN_DNS_RETURN_CODE_ defines.
369 unsigned int return_code : 4 GNUNET_PACKED;
374 unsigned int checking_disabled : 1 GNUNET_PACKED;
377 * Response has been cryptographically verified, RFC 4035.
379 unsigned int authenticated_data : 1 GNUNET_PACKED;
384 unsigned int zero : 1 GNUNET_PACKED;
387 * Set to 1 if recursion is available (server -> client)
389 unsigned int recursion_available : 1 GNUNET_PACKED;
390 #elif __BYTE_ORDER == __BIG_ENDIAN
393 * query:0, response:1
395 unsigned int query_or_response : 1 GNUNET_PACKED;
398 * See GNUNET_TUN_DNS_OPCODE_ defines.
400 unsigned int opcode : 4 GNUNET_PACKED;
403 * Set to 1 if this is an authoritative answer
405 unsigned int authoritative_answer : 1 GNUNET_PACKED;
408 * Set to 1 if message is truncated
410 unsigned int message_truncated : 1 GNUNET_PACKED;
413 * Set to 1 if recursion is desired (client -> server)
415 unsigned int recursion_desired : 1 GNUNET_PACKED;
419 * Set to 1 if recursion is available (server -> client)
421 unsigned int recursion_available : 1 GNUNET_PACKED;
426 unsigned int zero : 1 GNUNET_PACKED;
429 * Response has been cryptographically verified, RFC 4035.
431 unsigned int authenticated_data : 1 GNUNET_PACKED;
436 unsigned int checking_disabled : 1 GNUNET_PACKED;
439 * See GNUNET_TUN_DNS_RETURN_CODE_ defines.
441 unsigned int return_code : 4 GNUNET_PACKED;
443 #error byteorder undefined
446 } GNUNET_GCC_STRUCT_LAYOUT;
453 struct GNUNET_TUN_DnsHeader
456 * Unique identifier for the request/response.
458 uint16_t id GNUNET_PACKED;
463 struct GNUNET_TUN_DnsFlags flags;
468 uint16_t query_count GNUNET_PACKED;
473 uint16_t answer_rcount GNUNET_PACKED;
476 * Number of authoritative answers.
478 uint16_t authority_rcount GNUNET_PACKED;
481 * Number of additional records.
483 uint16_t additional_rcount GNUNET_PACKED;
488 * Payload of DNS SOA record (header).
490 struct GNUNET_TUN_DnsSoaRecord
493 * The version number of the original copy of the zone. (NBO)
495 uint32_t serial GNUNET_PACKED;
498 * Time interval before the zone should be refreshed. (NBO)
500 uint32_t refresh GNUNET_PACKED;
503 * Time interval that should elapse before a failed refresh should
506 uint32_t retry GNUNET_PACKED;
509 * Time value that specifies the upper limit on the time interval
510 * that can elapse before the zone is no longer authoritative. (NBO)
512 uint32_t expire GNUNET_PACKED;
515 * The bit minimum TTL field that should be exported with any RR
516 * from this zone. (NBO)
518 uint32_t minimum GNUNET_PACKED;
523 * Payload of DNS SRV record (header).
525 struct GNUNET_TUN_DnsSrvRecord
529 * Preference for this entry (lower value is higher preference). Clients
530 * will contact hosts from the lowest-priority group first and fall back
531 * to higher priorities if the low-priority entries are unavailable. (NBO)
533 uint16_t prio GNUNET_PACKED;
536 * Relative weight for records with the same priority. Clients will use
537 * the hosts of the same (lowest) priority with a probability proportional
538 * to the weight given. (NBO)
540 uint16_t weight GNUNET_PACKED;
543 * TCP or UDP port of the service. (NBO)
545 uint16_t port GNUNET_PACKED;
547 /* followed by 'target' name */
552 * Payload of DNS CERT record.
554 struct GNUNET_TUN_DnsCertRecord
572 /* Followed by the certificate */
577 * Payload of DNSSEC TLSA record.
578 * http://datatracker.ietf.org/doc/draft-ietf-dane-protocol/
580 struct GNUNET_TUN_DnsTlsaRecord
588 * 3: domain-issued cert
594 * What part will be matched against the cert
595 * presented by server
596 * 0: Full cert (in binary)
597 * 1: Full cert (in DER)
602 * Matching type (of selected content)
607 uint8_t matching_type;
610 * followed by certificate association data
611 * The "certificate association data" to be matched.
612 * These bytes are either raw data (that is, the full certificate or
613 * its SubjectPublicKeyInfo, depending on the selector) for matching
614 * type 0, or the hash of the raw data for matching types 1 and 2.
615 * The data refers to the certificate in the association, not to the
616 * TLS ASN.1 Certificate object.
618 * The data is represented as a string of hex chars
624 * Payload of GNS VPN record
626 struct GNUNET_TUN_GnsVpnRecord
629 * The peer to contact
631 struct GNUNET_PeerIdentity peer;
634 * The protocol to use
638 /* followed by the servicename */
645 struct GNUNET_TUN_DnsQueryLine
648 * Desired type (GNUNET_DNSPARSER_TYPE_XXX). (NBO)
650 uint16_t type GNUNET_PACKED;
653 * Desired class (usually GNUNET_TUN_DNS_CLASS_INTERNET). (NBO)
655 uint16_t dns_traffic_class GNUNET_PACKED;
660 * General DNS record prefix.
662 struct GNUNET_TUN_DnsRecordLine
665 * Record type (GNUNET_DNSPARSER_TYPE_XXX). (NBO)
667 uint16_t type GNUNET_PACKED;
670 * Record class (usually GNUNET_TUN_DNS_CLASS_INTERNET). (NBO)
672 uint16_t dns_traffic_class GNUNET_PACKED;
675 * Expiration for the record (in seconds). (NBO)
677 uint32_t ttl GNUNET_PACKED;
680 * Number of bytes of data that follow. (NBO)
682 uint16_t data_len GNUNET_PACKED;
686 #define GNUNET_TUN_ICMPTYPE_ECHO_REPLY 0
687 #define GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE 3
688 #define GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH 4
689 #define GNUNET_TUN_ICMPTYPE_REDIRECT_MESSAGE 5
690 #define GNUNET_TUN_ICMPTYPE_ECHO_REQUEST 8
691 #define GNUNET_TUN_ICMPTYPE_ROUTER_ADVERTISEMENT 9
692 #define GNUNET_TUN_ICMPTYPE_ROUTER_SOLICITATION 10
693 #define GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED 11
695 #define GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE 1
696 #define GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG 2
697 #define GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED 3
698 #define GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM 4
699 #define GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST 128
700 #define GNUNET_TUN_ICMPTYPE6_ECHO_REPLY 129
706 struct GNUNET_TUN_IcmpHeader
710 uint16_t crc GNUNET_PACKED;
715 * ICMP Echo (request/reply)
719 uint16_t identifier GNUNET_PACKED;
720 uint16_t sequence_number GNUNET_PACKED;
724 * ICMP Destination Unreachable (RFC 1191)
728 uint16_t empty GNUNET_PACKED;
729 uint16_t next_hop_mtu GNUNET_PACKED;
730 /* followed by original IP header + first 8 bytes of original IP datagram */
731 } destination_unreachable;
736 struct in_addr redirect_gateway_address GNUNET_PACKED;
739 * MTU for packets that are too big (IPv6).
741 uint32_t packet_too_big_mtu GNUNET_PACKED;
748 GNUNET_NETWORK_STRUCT_END
752 * Initialize an IPv4 header.
754 * @param ip header to initialize
755 * @param protocol protocol to use (i.e. IPPROTO_UDP)
756 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
757 * @param src source IP address to use
758 * @param dst destination IP address to use
761 GNUNET_TUN_initialize_ipv4_header (struct GNUNET_TUN_IPv4Header *ip,
763 uint16_t payload_length,
764 const struct in_addr *src,
765 const struct in_addr *dst);
769 * Initialize an IPv6 header.
771 * @param ip header to initialize
772 * @param protocol protocol to use (i.e. IPPROTO_UDP)
773 * @param payload_length number of bytes of payload that follow (excluding IPv4 header)
774 * @param src source IP address to use
775 * @param dst destination IP address to use
778 GNUNET_TUN_initialize_ipv6_header (struct GNUNET_TUN_IPv6Header *ip,
780 uint16_t payload_length,
781 const struct in6_addr *src,
782 const struct in6_addr *dst);
785 * Calculate IPv4 TCP checksum.
787 * @param ip ipv4 header fully initialized
788 * @param tcp TCP header (initialized except for CRC)
789 * @param payload the TCP payload
790 * @param payload_length number of bytes of TCP @a payload
793 GNUNET_TUN_calculate_tcp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
794 struct GNUNET_TUN_TcpHeader *tcp,
796 uint16_t payload_length);
799 * Calculate IPv6 TCP checksum.
801 * @param ip ipv6 header fully initialized
802 * @param tcp TCP header (initialized except for CRC)
803 * @param payload the TCP payload
804 * @param payload_length number of bytes of TCP payload
807 GNUNET_TUN_calculate_tcp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
808 struct GNUNET_TUN_TcpHeader *tcp,
810 uint16_t payload_length);
813 * Calculate IPv4 UDP checksum.
815 * @param ip ipv4 header fully initialized
816 * @param udp UDP header (initialized except for CRC)
817 * @param payload the UDP payload
818 * @param payload_length number of bytes of UDP @a payload
821 GNUNET_TUN_calculate_udp4_checksum (const struct GNUNET_TUN_IPv4Header *ip,
822 struct GNUNET_TUN_UdpHeader *udp,
824 uint16_t payload_length);
828 * Calculate IPv6 UDP checksum.
830 * @param ip ipv6 header fully initialized
831 * @param udp UDP header (initialized except for CRC)
832 * @param payload the UDP payload
833 * @param payload_length number of bytes of @a payload
836 GNUNET_TUN_calculate_udp6_checksum (const struct GNUNET_TUN_IPv6Header *ip,
837 struct GNUNET_TUN_UdpHeader *udp,
839 uint16_t payload_length);
843 * Calculate ICMP checksum.
845 * @param icmp IMCP header (initialized except for CRC)
846 * @param payload the ICMP payload
847 * @param payload_length number of bytes of @a payload
850 GNUNET_TUN_calculate_icmp_checksum (struct GNUNET_TUN_IcmpHeader *icmp,
852 uint16_t payload_length);
856 * Create a regex in @a rxstr from the given @a ip and @a port.
858 * @param ip IPv4 representation.
859 * @param port destination port
860 * @param rxstr generated regex, must be at least #GNUNET_TUN_IPV4_REGEXLEN
864 GNUNET_TUN_ipv4toregexsearch (const struct in_addr *ip,
870 * Create a regex in @a rxstr from the given @a ipv6 and @a port.
872 * @param ipv6 IPv6 representation.
873 * @param port destination port
874 * @param rxstr generated regex, must be at least #GNUNET_TUN_IPV6_REGEXLEN
878 GNUNET_TUN_ipv6toregexsearch (const struct in6_addr *ipv6,
884 * Convert an exit policy to a regular expression. The exit policy
885 * specifies a set of subnets this peer is willing to serve as an
886 * exit for; the resulting regular expression will match the
887 * IPv6 address strings as returned by #GNUNET_TUN_ipv6toregexsearch.
889 * @param policy exit policy specification
890 * @return regular expression, NULL on error
893 GNUNET_TUN_ipv6policy2regex (const char *policy);
897 * Convert an exit policy to a regular expression. The exit policy
898 * specifies a set of subnets this peer is willing to serve as an
899 * exit for; the resulting regular expression will match the
900 * IPv4 address strings as returned by #GNUNET_TUN_ipv4toregexsearch.
902 * @param policy exit policy specification
903 * @return regular expression, NULL on error
906 GNUNET_TUN_ipv4policy2regex (const char *policy);
910 * Hash the service name of a hosted service to the
911 * hash code that is used to identify the service on
914 * @param service_name a string
915 * @param[out] hc corresponding hash
918 GNUNET_TUN_service_name_to_hash (const char *service_name,
919 struct GNUNET_HashCode *hc);
923 * Check if two sockaddrs are equal.
925 * @param sa one address
926 * @param sb another address
927 * @param include_port also check ports
928 * @return #GNUNET_YES if they are equal
931 GNUNET_TUN_sockaddr_cmp (const struct sockaddr *sa,
932 const struct sockaddr *sb,
937 * Compute the CADET port given a service descriptor
938 * (returned from #GNUNET_TUN_service_name_to_hash) and
939 * a TCP/UDP port @a ip_port.
941 * @param desc service shared secret
942 * @param ip_port TCP/UDP port, use 0 for ICMP
943 * @param[out] cadet_port CADET port to use
946 GNUNET_TUN_compute_service_cadet_port (const struct GNUNET_HashCode *desc,
948 struct GNUNET_HashCode *cadet_port);
952 /** @} */ /* end of group */