TUN library

Standard TCP/IP network structs and IP checksum calculations for TUN interaction. More...

Collaboration diagram for TUN library:

Data Structures
struct	GNUNET_TUN_Layer2PacketHeader
	Header from Linux TUN interface. More...
struct	GNUNET_TUN_IPv4Header
	Standard IPv4 header. More...
struct	GNUNET_TUN_IPv6Header
	Standard IPv6 header. More...
struct	GNUNET_TUN_TcpHeader
	TCP packet header. More...
struct	GNUNET_TUN_UdpHeader
	UDP packet header. More...
struct	GNUNET_TUN_DnsFlags
	DNS flags (largely RFC 1035 / RFC 2136). More...
struct	GNUNET_TUN_DnsHeader
	DNS header. More...
struct	GNUNET_TUN_DnsSoaRecord
	Payload of DNS SOA record (header). More...
struct	GNUNET_TUN_DnsSrvRecord
	Payload of DNS SRV record (header). More...
struct	GNUNET_TUN_DnsUriRecord
	Payload of DNS URI record (header). More...
struct	GNUNET_TUN_DnsCertRecord
	Payload of DNS CERT record. More...
struct	GNUNET_TUN_DnsTlsaRecord
	Payload of DNSSEC TLSA record. More...
struct	GNUNET_TUN_GnsVpnRecord
	Payload of GNS VPN record. More...
struct	GNUNET_TUN_DnsQueryLine
	DNS query prefix. More...
struct	GNUNET_TUN_DnsRecordLine
	General DNS record prefix. More...
struct	GNUNET_TUN_IcmpHeader
	ICMP header. More...

Macros
#define	ETH_P_IPV4   0x0800
	Number for IPv4. More...
#define	ETH_P_IPV6   0x86DD
	Number for IPv6. More...
#define	GNUNET_TUN_IPV4_REGEXLEN   16
	Maximum regex string length for use with GNUNET_REGEX_ipv4toregexsearch. More...
#define	GNUNET_TUN_IPV6_REGEXLEN   40
	Maximum regex string length for use with GNUNET_REGEX_ipv6toregexsearch. More...
#define	GNUNET_TUN_TCP_FLAGS_FIN   1
	TCP flags. More...
#define	GNUNET_TUN_TCP_FLAGS_SYN   2
#define	GNUNET_TUN_TCP_FLAGS_RST   4
#define	GNUNET_TUN_TCP_FLAGS_PSH   8
#define	GNUNET_TUN_TCP_FLAGS_ACK   16
#define	GNUNET_TUN_TCP_FLAGS_URG   32
#define	GNUNET_TUN_TCP_FLAGS_ECE   64
#define	GNUNET_TUN_TCP_FLAGS_CWR   128
#define	GNUNET_TUN_DNS_CLASS_INTERNET   1
	A few common DNS classes (ok, only one is common, but I list a couple more to make it clear what we're talking about here). More...
#define	GNUNET_TUN_DNS_CLASS_CHAOS   3
#define	GNUNET_TUN_DNS_CLASS_HESIOD   4
#define	GNUNET_TUN_DNS_OPCODE_QUERY   0
#define	GNUNET_TUN_DNS_OPCODE_INVERSE_QUERY   1
#define	GNUNET_TUN_DNS_OPCODE_STATUS   2
#define	GNUNET_TUN_DNS_RETURN_CODE_NO_ERROR   0
	RFC 1035 codes. More...
#define	GNUNET_TUN_DNS_RETURN_CODE_FORMAT_ERROR   1
#define	GNUNET_TUN_DNS_RETURN_CODE_SERVER_FAILURE   2
#define	GNUNET_TUN_DNS_RETURN_CODE_NAME_ERROR   3
#define	GNUNET_TUN_DNS_RETURN_CODE_NOT_IMPLEMENTED   4
#define	GNUNET_TUN_DNS_RETURN_CODE_REFUSED   5
#define	GNUNET_TUN_DNS_RETURN_CODE_YXDOMAIN   6
	RFC 2136 codes. More...
#define	GNUNET_TUN_DNS_RETURN_CODE_YXRRSET   7
#define	GNUNET_TUN_DNS_RETURN_CODE_NXRRSET   8
#define	GNUNET_TUN_DNS_RETURN_CODE_NOT_AUTH   9
#define	GNUNET_TUN_DNS_RETURN_CODE_NOT_ZONE   10
#define	GNUNET_TUN_ICMPTYPE_ECHO_REPLY   0
#define	GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE   3
#define	GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH   4
#define	GNUNET_TUN_ICMPTYPE_REDIRECT_MESSAGE   5
#define	GNUNET_TUN_ICMPTYPE_ECHO_REQUEST   8
#define	GNUNET_TUN_ICMPTYPE_ROUTER_ADVERTISEMENT   9
#define	GNUNET_TUN_ICMPTYPE_ROUTER_SOLICITATION   10
#define	GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED   11
#define	GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE   1
#define	GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG   2
#define	GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED   3
#define	GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM   4
#define	GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST   128
#define	GNUNET_TUN_ICMPTYPE6_ECHO_REPLY   129
#define	GNUNET_GCC_STRUCT_LAYOUT
	gcc-ism to get gcc bitfield layout when compiling with -mms-bitfields More...

Functions
GNUNET_NETWORK_STRUCT_END void	GNUNET_TUN_initialize_ipv4_header (struct GNUNET_TUN_IPv4Header *ip, uint8_t protocol, uint16_t payload_length, const struct in_addr *src, const struct in_addr *dst)
	Initialize an IPv4 header. More...
void	GNUNET_TUN_initialize_ipv6_header (struct GNUNET_TUN_IPv6Header *ip, uint8_t protocol, uint16_t payload_length, const struct in6_addr *src, const struct in6_addr *dst)
	Initialize an IPv6 header. More...
void	GNUNET_TUN_calculate_tcp4_checksum (const struct GNUNET_TUN_IPv4Header *ip, struct GNUNET_TUN_TcpHeader *tcp, const void *payload, uint16_t payload_length)
	Calculate IPv4 TCP checksum. More...
void	GNUNET_TUN_calculate_tcp6_checksum (const struct GNUNET_TUN_IPv6Header *ip, struct GNUNET_TUN_TcpHeader *tcp, const void *payload, uint16_t payload_length)
	Calculate IPv6 TCP checksum. More...
void	GNUNET_TUN_calculate_udp4_checksum (const struct GNUNET_TUN_IPv4Header *ip, struct GNUNET_TUN_UdpHeader *udp, const void *payload, uint16_t payload_length)
	Calculate IPv4 UDP checksum. More...
void	GNUNET_TUN_calculate_udp6_checksum (const struct GNUNET_TUN_IPv6Header *ip, struct GNUNET_TUN_UdpHeader *udp, const void *payload, uint16_t payload_length)
	Calculate IPv6 UDP checksum. More...
void	GNUNET_TUN_calculate_icmp_checksum (struct GNUNET_TUN_IcmpHeader *icmp, const void *payload, uint16_t payload_length)
	Calculate ICMP checksum. More...
void	GNUNET_TUN_service_name_to_hash (const char *service_name, struct GNUNET_HashCode *hc)
	Hash the service name of a hosted service to the hash code that is used to identify the service on the network. More...
int	GNUNET_TUN_sockaddr_cmp (const struct sockaddr *sa, const struct sockaddr *sb, int include_port)
	Check if two sockaddrs are equal. More...
void	GNUNET_TUN_compute_service_cadet_port (const struct GNUNET_HashCode *desc, uint16_t ip_port, struct GNUNET_HashCode *cadet_port)
	Compute the CADET port given a service descriptor (returned from GNUNET_TUN_service_name_to_hash) and a TCP/UDP port ip_port. More...

Variables
struct GNUNET_TUN_IPv4Header	GNUNET_GCC_STRUCT_LAYOUT

Detailed Description

Standard TCP/IP network structs and IP checksum calculations for TUN interaction.

Macro Definition Documentation

ETH_P_IPV4

#define ETH_P_IPV4   0x0800

Number for IPv4.

Definition at line 50 of file gnunet_tun_lib.h.

ETH_P_IPV6

#define ETH_P_IPV6   0x86DD

Number for IPv6.

Definition at line 57 of file gnunet_tun_lib.h.

GNUNET_TUN_IPV4_REGEXLEN

#define GNUNET_TUN_IPV4_REGEXLEN   16

Maximum regex string length for use with GNUNET_REGEX_ipv4toregexsearch.

8 bytes for IPv4, 4 bytes for port, 1 byte for "4", 2 bytes for "-", one byte for 0-termination.

Definition at line 68 of file gnunet_tun_lib.h.

GNUNET_TUN_IPV6_REGEXLEN

#define GNUNET_TUN_IPV6_REGEXLEN   40

Maximum regex string length for use with GNUNET_REGEX_ipv6toregexsearch.

32 bytes for IPv4, 4 bytes for port, 1 byte for "4", 2 bytes for "-", one byte for 0-termination.

Definition at line 77 of file gnunet_tun_lib.h.

GNUNET_TUN_TCP_FLAGS_FIN

#define GNUNET_TUN_TCP_FLAGS_FIN   1

TCP flags.

Definition at line 203 of file gnunet_tun_lib.h.

GNUNET_TUN_TCP_FLAGS_SYN

#define GNUNET_TUN_TCP_FLAGS_SYN   2

Definition at line 204 of file gnunet_tun_lib.h.

GNUNET_TUN_TCP_FLAGS_RST

#define GNUNET_TUN_TCP_FLAGS_RST   4

Definition at line 205 of file gnunet_tun_lib.h.

GNUNET_TUN_TCP_FLAGS_PSH

#define GNUNET_TUN_TCP_FLAGS_PSH   8

Definition at line 206 of file gnunet_tun_lib.h.

GNUNET_TUN_TCP_FLAGS_ACK

#define GNUNET_TUN_TCP_FLAGS_ACK   16

Definition at line 207 of file gnunet_tun_lib.h.

GNUNET_TUN_TCP_FLAGS_URG

#define GNUNET_TUN_TCP_FLAGS_URG   32

Definition at line 208 of file gnunet_tun_lib.h.

GNUNET_TUN_TCP_FLAGS_ECE

#define GNUNET_TUN_TCP_FLAGS_ECE   64

Definition at line 209 of file gnunet_tun_lib.h.

GNUNET_TUN_TCP_FLAGS_CWR

#define GNUNET_TUN_TCP_FLAGS_CWR   128

Definition at line 210 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_CLASS_INTERNET

#define GNUNET_TUN_DNS_CLASS_INTERNET   1

A few common DNS classes (ok, only one is common, but I list a couple more to make it clear what we're talking about here).

Definition at line 311 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_CLASS_CHAOS

#define GNUNET_TUN_DNS_CLASS_CHAOS   3

Definition at line 312 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_CLASS_HESIOD

#define GNUNET_TUN_DNS_CLASS_HESIOD   4

Definition at line 313 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_OPCODE_QUERY

#define GNUNET_TUN_DNS_OPCODE_QUERY   0

Definition at line 315 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_OPCODE_INVERSE_QUERY

#define GNUNET_TUN_DNS_OPCODE_INVERSE_QUERY   1

Definition at line 316 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_OPCODE_STATUS

#define GNUNET_TUN_DNS_OPCODE_STATUS   2

Definition at line 317 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_NO_ERROR

#define GNUNET_TUN_DNS_RETURN_CODE_NO_ERROR   0

RFC 1035 codes.

Definition at line 323 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_FORMAT_ERROR

#define GNUNET_TUN_DNS_RETURN_CODE_FORMAT_ERROR   1

Definition at line 324 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_SERVER_FAILURE

#define GNUNET_TUN_DNS_RETURN_CODE_SERVER_FAILURE   2

Definition at line 325 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_NAME_ERROR

#define GNUNET_TUN_DNS_RETURN_CODE_NAME_ERROR   3

Definition at line 326 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_NOT_IMPLEMENTED

#define GNUNET_TUN_DNS_RETURN_CODE_NOT_IMPLEMENTED   4

Definition at line 327 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_REFUSED

#define GNUNET_TUN_DNS_RETURN_CODE_REFUSED   5

Definition at line 328 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_YXDOMAIN

#define GNUNET_TUN_DNS_RETURN_CODE_YXDOMAIN   6

RFC 2136 codes.

Definition at line 333 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_YXRRSET

#define GNUNET_TUN_DNS_RETURN_CODE_YXRRSET   7

Definition at line 334 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_NXRRSET

#define GNUNET_TUN_DNS_RETURN_CODE_NXRRSET   8

Definition at line 335 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_NOT_AUTH

#define GNUNET_TUN_DNS_RETURN_CODE_NOT_AUTH   9

Definition at line 336 of file gnunet_tun_lib.h.

GNUNET_TUN_DNS_RETURN_CODE_NOT_ZONE

#define GNUNET_TUN_DNS_RETURN_CODE_NOT_ZONE   10

Definition at line 337 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE_ECHO_REPLY

#define GNUNET_TUN_ICMPTYPE_ECHO_REPLY   0

Definition at line 708 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE

#define GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE   3

Definition at line 709 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH

#define GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH   4

Definition at line 710 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE_REDIRECT_MESSAGE

#define GNUNET_TUN_ICMPTYPE_REDIRECT_MESSAGE   5

Definition at line 711 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE_ECHO_REQUEST

#define GNUNET_TUN_ICMPTYPE_ECHO_REQUEST   8

Definition at line 712 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE_ROUTER_ADVERTISEMENT

#define GNUNET_TUN_ICMPTYPE_ROUTER_ADVERTISEMENT   9

Definition at line 713 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE_ROUTER_SOLICITATION

#define GNUNET_TUN_ICMPTYPE_ROUTER_SOLICITATION   10

Definition at line 714 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED

#define GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED   11

Definition at line 715 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE

#define GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE   1

Definition at line 717 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG

#define GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG   2

Definition at line 718 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED

#define GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED   3

Definition at line 719 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM

#define GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM   4

Definition at line 720 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST

#define GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST   128

Definition at line 721 of file gnunet_tun_lib.h.

GNUNET_TUN_ICMPTYPE6_ECHO_REPLY

#define GNUNET_TUN_ICMPTYPE6_ECHO_REPLY   129

Definition at line 722 of file gnunet_tun_lib.h.

GNUNET_GCC_STRUCT_LAYOUT

struct GNUNET_TUN_DnsFlags GNUNET_GCC_STRUCT_LAYOUT

gcc-ism to get gcc bitfield layout when compiling with -mms-bitfields

Definition at line 243 of file gnunet_common.h.

Function Documentation

GNUNET_TUN_initialize_ipv4_header()

GNUNET_NETWORK_STRUCT_END void GNUNET_TUN_initialize_ipv4_header	(	struct GNUNET_TUN_IPv4Header *	ip,
		uint8_t	protocol,
		uint16_t	payload_length,
		const struct in_addr *	src,
		const struct in_addr *	dst
	)

Initialize an IPv4 header.

Parameters

ip	header to initialize
protocol	protocol to use (e.g. IPPROTO_UDP)
payload_length	number of bytes of payload that follow (excluding IPv4 header)
src	source IP address to use
dst	destination IP address to use

Definition at line 80 of file tun.c.

{
  GNUNET_assert (20 == sizeof(struct GNUNET_TUN_IPv4Header));
  GNUNET_assert (payload_length <=
                 UINT16_MAX - sizeof(struct GNUNET_TUN_IPv4Header));
  memset (ip, 0, sizeof(struct GNUNET_TUN_IPv4Header));
  ip->header_length = sizeof(struct GNUNET_TUN_IPv4Header) / 4;
  ip->version = 4;
  ip->total_length =
    htons (sizeof(struct GNUNET_TUN_IPv4Header) + payload_length);
  ip->identification =
    (uint16_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, 65536);
  ip->ttl = FRESH_TTL;
  ip->protocol = protocol;
  ip->source_address = *src;
  ip->destination_address = *dst;
  ip->checksum =
    GNUNET_CRYPTO_crc16_n (ip, sizeof(struct GNUNET_TUN_IPv4Header));
}

References GNUNET_TUN_IPv4Header::checksum, GNUNET_TUN_IPv4Header::destination_address, FRESH_TTL, GNUNET_assert, GNUNET_CRYPTO_crc16_n(), GNUNET_CRYPTO_QUALITY_WEAK, GNUNET_CRYPTO_random_u32(), GNUNET_TUN_IPv4Header::header_length, GNUNET_TUN_IPv4Header::identification, GNUNET_TUN_IPv4Header::protocol, GNUNET_TUN_IPv4Header::source_address, GNUNET_TUN_IPv4Header::total_length, GNUNET_TUN_IPv4Header::ttl, and GNUNET_TUN_IPv4Header::version.

Referenced by handle_icmp_back(), handle_tcp_back(), handle_udp_back(), make_up_icmpv4_payload(), prepare_ipv4_packet(), request_done(), and send_icmp_packet_via_tun().

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GNUNET_TUN_initialize_ipv6_header()

void GNUNET_TUN_initialize_ipv6_header	(	struct GNUNET_TUN_IPv6Header *	ip,
		uint8_t	protocol,
		uint16_t	payload_length,
		const struct in6_addr *	src,
		const struct in6_addr *	dst
	)

Initialize an IPv6 header.

Parameters

ip	header to initialize
protocol	protocol to use (e.g. IPPROTO_UDP)
payload_length	number of bytes of payload that follow (excluding IPv4 header)
src	source IP address to use
dst	destination IP address to use
ip	header to initialize
protocol	protocol to use (e.g. IPPROTO_UDP), technically "next_header" for IPv6
payload_length	number of bytes of payload that follow (excluding IPv6 header)
src	source IP address to use
dst	destination IP address to use

Definition at line 115 of file tun.c.

{
  GNUNET_assert (40 == sizeof(struct GNUNET_TUN_IPv6Header));
  GNUNET_assert (payload_length <=
                 UINT16_MAX - sizeof(struct GNUNET_TUN_IPv6Header));
  memset (ip, 0, sizeof(struct GNUNET_TUN_IPv6Header));
  ip->version = 6;
  ip->next_header = protocol;
  ip->payload_length = htons ((uint16_t) payload_length);
  ip->hop_limit = FRESH_TTL;
  ip->destination_address = *dst;
  ip->source_address = *src;
}

References GNUNET_TUN_IPv6Header::destination_address, FRESH_TTL, GNUNET_assert, GNUNET_TUN_IPv6Header::hop_limit, GNUNET_TUN_IPv6Header::next_header, GNUNET_TUN_IPv6Header::payload_length, GNUNET_TUN_IPv4Header::protocol, GNUNET_TUN_IPv6Header::source_address, and GNUNET_TUN_IPv6Header::version.

Referenced by handle_icmp_back(), handle_tcp_back(), handle_udp_back(), make_up_icmpv6_payload(), prepare_ipv6_packet(), request_done(), and send_icmp_packet_via_tun().

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GNUNET_TUN_calculate_tcp4_checksum()

void GNUNET_TUN_calculate_tcp4_checksum	(	const struct GNUNET_TUN_IPv4Header *	ip,
		struct GNUNET_TUN_TcpHeader *	tcp,
		const void *	payload,
		uint16_t	payload_length
	)

Calculate IPv4 TCP checksum.

Parameters

ip	ipv4 header fully initialized
tcp	TCP header (initialized except for CRC)
payload	the TCP payload
payload_length	number of bytes of TCP payload

Definition at line 135 of file tun.c.

{
  uint32_t sum;
  uint16_t tmp;
 
  GNUNET_assert (20 == sizeof(struct GNUNET_TUN_TcpHeader));
  GNUNET_assert (payload_length + sizeof(struct GNUNET_TUN_IPv4Header)
                 + sizeof(struct GNUNET_TUN_TcpHeader) ==
                 ntohs (ip->total_length));
  GNUNET_assert (IPPROTO_TCP == ip->protocol);
 
  tcp->crc = 0;
  sum = GNUNET_CRYPTO_crc16_step (0,
                                  &ip->source_address,
                                  sizeof(struct in_addr) * 2);
  tmp = htons (IPPROTO_TCP);
  sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof(uint16_t));
  tmp = htons (payload_length + sizeof(struct GNUNET_TUN_TcpHeader));
  sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof(uint16_t));
  sum =
    GNUNET_CRYPTO_crc16_step (sum, tcp, sizeof(struct GNUNET_TUN_TcpHeader));
  sum = GNUNET_CRYPTO_crc16_step (sum, payload, payload_length);
  tcp->crc = GNUNET_CRYPTO_crc16_finish (sum);
}

References GNUNET_assert, GNUNET_CRYPTO_crc16_finish(), GNUNET_CRYPTO_crc16_step(), payload, GNUNET_TUN_IPv4Header::protocol, GNUNET_TUN_IPv4Header::source_address, consensus-simulation::sum, tcp, and GNUNET_TUN_IPv4Header::total_length.

Referenced by handle_tcp_back(), and prepare_ipv4_packet().

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GNUNET_TUN_calculate_tcp6_checksum()

void GNUNET_TUN_calculate_tcp6_checksum	(	const struct GNUNET_TUN_IPv6Header *	ip,
		struct GNUNET_TUN_TcpHeader *	tcp,
		const void *	payload,
		uint16_t	payload_length
	)

Calculate IPv6 TCP checksum.

Parameters

ip	ipv6 header fully initialized
tcp	TCP header (initialized except for CRC)
payload	the TCP payload
payload_length	number of bytes of TCP payload

Definition at line 165 of file tun.c.

{
  uint32_t sum;
  uint32_t tmp;
 
  GNUNET_assert (20 == sizeof(struct GNUNET_TUN_TcpHeader));
  GNUNET_assert (payload_length + sizeof(struct GNUNET_TUN_TcpHeader) ==
                 ntohs (ip->payload_length));
  GNUNET_assert (IPPROTO_TCP == ip->next_header);
  tcp->crc = 0;
  sum = GNUNET_CRYPTO_crc16_step (0,
                                  &ip->source_address,
                                  2 * sizeof(struct in6_addr));
  tmp = htonl (sizeof(struct GNUNET_TUN_TcpHeader) + payload_length);
  sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof(uint32_t));
  tmp = htonl (IPPROTO_TCP);
  sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof(uint32_t));
  sum =
    GNUNET_CRYPTO_crc16_step (sum, tcp, sizeof(struct GNUNET_TUN_TcpHeader));
  sum = GNUNET_CRYPTO_crc16_step (sum, payload, payload_length);
  tcp->crc = GNUNET_CRYPTO_crc16_finish (sum);
}

References GNUNET_assert, GNUNET_CRYPTO_crc16_finish(), GNUNET_CRYPTO_crc16_step(), GNUNET_TUN_IPv6Header::next_header, payload, GNUNET_TUN_IPv6Header::payload_length, GNUNET_TUN_IPv6Header::source_address, consensus-simulation::sum, and tcp.

Referenced by handle_tcp_back(), and prepare_ipv6_packet().

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GNUNET_TUN_calculate_udp4_checksum()

void GNUNET_TUN_calculate_udp4_checksum	(	const struct GNUNET_TUN_IPv4Header *	ip,
		struct GNUNET_TUN_UdpHeader *	udp,
		const void *	payload,
		uint16_t	payload_length
	)

Calculate IPv4 UDP checksum.

Parameters

ip	ipv4 header fully initialized
udp	UDP header (initialized except for CRC)
payload	the UDP payload
payload_length	number of bytes of UDP payload

Definition at line 193 of file tun.c.

{
  uint32_t sum;
  uint16_t tmp;
 
  GNUNET_assert (8 == sizeof(struct GNUNET_TUN_UdpHeader));
  GNUNET_assert (payload_length + sizeof(struct GNUNET_TUN_IPv4Header)
                 + sizeof(struct GNUNET_TUN_UdpHeader) ==
                 ntohs (ip->total_length));
  GNUNET_assert (IPPROTO_UDP == ip->protocol);
 
  udp->crc =
    0; /* technically optional, but we calculate it anyway, just to be sure */
  sum = GNUNET_CRYPTO_crc16_step (0,
                                  &ip->source_address,
                                  sizeof(struct in_addr) * 2);
  tmp = htons (IPPROTO_UDP);
  sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof(uint16_t));
  tmp = htons (sizeof(struct GNUNET_TUN_UdpHeader) + payload_length);
  sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof(uint16_t));
  sum =
    GNUNET_CRYPTO_crc16_step (sum, udp, sizeof(struct GNUNET_TUN_UdpHeader));
  sum = GNUNET_CRYPTO_crc16_step (sum, payload, payload_length);
  udp->crc = GNUNET_CRYPTO_crc16_finish (sum);
}

References GNUNET_assert, GNUNET_CRYPTO_crc16_finish(), GNUNET_CRYPTO_crc16_step(), payload, GNUNET_TUN_IPv4Header::protocol, GNUNET_TUN_IPv4Header::source_address, consensus-simulation::sum, GNUNET_TUN_IPv4Header::total_length, and udp.

Referenced by handle_udp_back(), prepare_ipv4_packet(), and request_done().

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GNUNET_TUN_calculate_udp6_checksum()

void GNUNET_TUN_calculate_udp6_checksum	(	const struct GNUNET_TUN_IPv6Header *	ip,
		struct GNUNET_TUN_UdpHeader *	udp,
		const void *	payload,
		uint16_t	payload_length
	)

Calculate IPv6 UDP checksum.

Parameters

ip	ipv6 header fully initialized
udp	UDP header (initialized except for CRC)
payload	the UDP payload
payload_length	number of bytes of payload

Definition at line 224 of file tun.c.

{
  uint32_t sum;
  uint32_t tmp;
 
  GNUNET_assert (payload_length + sizeof(struct GNUNET_TUN_UdpHeader) ==
                 ntohs (ip->payload_length));
  GNUNET_assert (payload_length + sizeof(struct GNUNET_TUN_UdpHeader) ==
                 ntohs (udp->len));
  GNUNET_assert (IPPROTO_UDP == ip->next_header);
 
  udp->crc = 0;
  sum = GNUNET_CRYPTO_crc16_step (0,
                                  &ip->source_address,
                                  sizeof(struct in6_addr) * 2);
  tmp = htons (sizeof(struct GNUNET_TUN_UdpHeader)
               + payload_length); /* aka udp->len */
  sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof(uint32_t));
  tmp = htons (ip->next_header);
  sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof(uint32_t));
  sum =
    GNUNET_CRYPTO_crc16_step (sum, udp, sizeof(struct GNUNET_TUN_UdpHeader));
  sum = GNUNET_CRYPTO_crc16_step (sum, payload, payload_length);
  udp->crc = GNUNET_CRYPTO_crc16_finish (sum);
}

References GNUNET_assert, GNUNET_CRYPTO_crc16_finish(), GNUNET_CRYPTO_crc16_step(), GNUNET_TUN_IPv6Header::next_header, payload, GNUNET_TUN_IPv6Header::payload_length, GNUNET_TUN_IPv6Header::source_address, consensus-simulation::sum, and udp.

Referenced by handle_udp_back(), prepare_ipv6_packet(), and request_done().

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GNUNET_TUN_calculate_icmp_checksum()

void GNUNET_TUN_calculate_icmp_checksum	(	struct GNUNET_TUN_IcmpHeader *	icmp,
		const void *	payload,
		uint16_t	payload_length
	)

Calculate ICMP checksum.

Parameters

icmp	IMCP header (initialized except for CRC)
payload	the ICMP payload
payload_length	number of bytes of payload

Definition at line 255 of file tun.c.

{
  uint32_t sum;
 
  GNUNET_assert (8 == sizeof(struct GNUNET_TUN_IcmpHeader));
  icmp->crc = 0;
  sum =
    GNUNET_CRYPTO_crc16_step (0, icmp, sizeof(struct GNUNET_TUN_IcmpHeader));
  sum = GNUNET_CRYPTO_crc16_step (sum, payload, payload_length);
  icmp->crc = GNUNET_CRYPTO_crc16_finish (sum);
}

References GNUNET_TUN_IcmpHeader::crc, GNUNET_assert, GNUNET_CRYPTO_crc16_finish(), GNUNET_CRYPTO_crc16_step(), payload, and consensus-simulation::sum.

Referenced by handle_icmp_back(), and send_icmp_packet_via_tun().

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GNUNET_TUN_service_name_to_hash()

void GNUNET_TUN_service_name_to_hash	(	const char *	service_name,
		struct GNUNET_HashCode *	hc
	)

Hash the service name of a hosted service to the hash code that is used to identify the service on the network.

Parameters

	service_name	a string
[out]	hc	corresponding hash

Definition at line 38 of file tun.c.

{
  GNUNET_CRYPTO_hash (service_name,
                      strlen (service_name),
                      hc);
}

References GNUNET_CRYPTO_hash(), and service_name.

Referenced by result_processor(), run(), and store_service().

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GNUNET_TUN_sockaddr_cmp()

int GNUNET_TUN_sockaddr_cmp	(	const struct sockaddr *	sa,
		const struct sockaddr *	sb,
		int	include_port
	)

Check if two sockaddrs are equal.

Parameters

sa	one address
sb	another address
include_port	also check ports

Returns

GNUNET_YES if they are equal

Definition at line 279 of file tun.c.

{
  if (sa->sa_family != sb->sa_family)
    return GNUNET_NO;
 
  switch (sa->sa_family)
  {
  case AF_INET: {
      const struct sockaddr_in *sa4 = (const struct sockaddr_in *) sa;
      const struct sockaddr_in *sb4 = (const struct sockaddr_in *) sb;
      if ((include_port) && (sa4->sin_port != sb4->sin_port))
        return GNUNET_NO;
      return(sa4->sin_addr.s_addr == sb4->sin_addr.s_addr);
    }
 
  case AF_INET6: {
      const struct sockaddr_in6 *sa6 = (const struct sockaddr_in6 *) sa;
      const struct sockaddr_in6 *sb6 = (const struct sockaddr_in6 *) sb;
 
      if ((include_port) && (sa6->sin6_port != sb6->sin6_port))
        return GNUNET_NO;
      return(
        0 == memcmp (&sa6->sin6_addr, &sb6->sin6_addr, sizeof(struct
                                                              in6_addr)));
    }
 
  default:
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
}

References GNUNET_break, GNUNET_NO, and GNUNET_SYSERR.

GNUNET_TUN_compute_service_cadet_port()

void GNUNET_TUN_compute_service_cadet_port	(	const struct GNUNET_HashCode *	desc,
		uint16_t	ip_port,
		struct GNUNET_HashCode *	cadet_port
	)

Compute the CADET port given a service descriptor (returned from GNUNET_TUN_service_name_to_hash) and a TCP/UDP port ip_port.

Parameters

	desc	service shared secret
	ip_port	TCP/UDP port, use 0 for ICMP
[out]	cadet_port	CADET port to use

Definition at line 57 of file tun.c.

{
  uint16_t be_port = htons (ip_port);
 
  *cadet_port = *desc;
  GNUNET_memcpy (cadet_port,
                 &be_port,
                 sizeof(uint16_t));
}

References cadet_port, and GNUNET_memcpy.

Referenced by create_channel_to_destination(), and store_service().

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Variable Documentation

GNUNET_GCC_STRUCT_LAYOUT

struct GNUNET_TUN_DnsFlags GNUNET_GCC_STRUCT_LAYOUT