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Diffstat (limited to 'src/include/gnunet_tun_lib.h')
| -rw-r--r-- | src/include/gnunet_tun_lib.h | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/src/include/gnunet_tun_lib.h b/src/include/gnunet_tun_lib.h new file mode 100644 index 0000000..dac11d6 --- /dev/null +++ b/src/include/gnunet_tun_lib.h @@ -0,0 +1,420 @@ +/* + This file is part of GNUnet. + (C) 2010, 2011, 2012 Christian Grothoff + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +/** + * @file include/gnunet_tun_lib.h + * @brief standard TCP/IP network structs and IP checksum calculations for TUN interaction + * @author Philipp Toelke + * @author Christian Grothoff + */ +#ifndef GNUNET_TUN_LIB_H +#define GNUNET_TUN_LIB_H + +#include "gnunet_util_lib.h" + + +/* see http://www.iana.org/assignments/ethernet-numbers */ +#ifndef ETH_P_IPV4 +/** + * Number for IPv4 + */ +#define ETH_P_IPV4 0x0800 +#endif + +#ifndef ETH_P_IPV6 +/** + * Number for IPv6 + */ +#define ETH_P_IPV6 0x86DD +#endif + + +GNUNET_NETWORK_STRUCT_BEGIN + +/** + * Header from Linux TUN interface. + */ +struct GNUNET_TUN_Layer2PacketHeader +{ + /** + * Some flags (unused). + */ + uint16_t flags GNUNET_PACKED; + + /** + * Here we get an ETH_P_-number. + */ + uint16_t proto GNUNET_PACKED; +}; + + +/** + * Standard IPv4 header. + */ +struct GNUNET_TUN_IPv4Header +{ +#if __BYTE_ORDER == __LITTLE_ENDIAN + unsigned int header_length:4 GNUNET_PACKED; + unsigned int version:4 GNUNET_PACKED; +#elif __BYTE_ORDER == __BIG_ENDIAN + unsigned int version:4 GNUNET_PACKED; + unsigned int header_length:4 GNUNET_PACKED; +#else + #error byteorder undefined +#endif + uint8_t diff_serv; + + /** + * Length of the packet, including this header. + */ + uint16_t total_length GNUNET_PACKED; + + /** + * Unique random ID for matching up fragments. + */ + uint16_t identification GNUNET_PACKED; + + unsigned int flags:3 GNUNET_PACKED; + + unsigned int fragmentation_offset:13 GNUNET_PACKED; + + /** + * How many more hops can this packet be forwarded? + */ + uint8_t ttl; + + /** + * L4-protocol, for example, IPPROTO_UDP or IPPROTO_TCP. + */ + uint8_t protocol; + + /** + * Checksum. + */ + uint16_t checksum GNUNET_PACKED; + + /** + * Origin of the packet. + */ + struct in_addr source_address GNUNET_PACKED; + + /** + * Destination of the packet. + */ + struct in_addr destination_address GNUNET_PACKED; +}; + + +/** + * Standard IPv6 header. + */ +struct GNUNET_TUN_IPv6Header +{ +#if __BYTE_ORDER == __LITTLE_ENDIAN + unsigned int traffic_class_h:4 GNUNET_PACKED; + unsigned int version:4 GNUNET_PACKED; + unsigned int traffic_class_l:4 GNUNET_PACKED; + unsigned int flow_label:20 GNUNET_PACKED; +#elif __BYTE_ORDER == __BIG_ENDIAN + unsigned int version:4 GNUNET_PACKED; + unsigned int traffic_class:8 GNUNET_PACKED; + unsigned int flow_label:20 GNUNET_PACKED; +#else + #error byteorder undefined +#endif + /** + * Length of the payload, excluding this header. + */ + uint16_t payload_length GNUNET_PACKED; + + /** + * For example, IPPROTO_UDP or IPPROTO_TCP. + */ + uint8_t next_header; + + /** + * How many more hops can this packet be forwarded? + */ + uint8_t hop_limit; + + /** + * Origin of the packet. + */ + struct in6_addr source_address GNUNET_PACKED; + + /** + * Destination of the packet. + */ + struct in6_addr destination_address GNUNET_PACKED; +}; + + +/** + * TCP packet header. + */ +struct GNUNET_TUN_TcpHeader +{ + uint16_t source_port GNUNET_PACKED; + uint16_t destination_port GNUNET_PACKED; + + /** + * Sequence number. + */ + uint32_t seq GNUNET_PACKED; + + /** + * Acknowledgement number. + */ + uint32_t ack GNUNET_PACKED; +#if __BYTE_ORDER == __LITTLE_ENDIAN + /** + * Reserved. Must be zero. + */ + unsigned int reserved : 4 GNUNET_PACKED; + /** + * Number of 32-bit words in TCP header. + */ + unsigned int off : 4 GNUNET_PACKED; +#elif __BYTE_ORDER == __BIG_ENDIAN + /** + * Number of 32-bit words in TCP header. + */ + unsigned int off : 4 GNUNET_PACKED; + /** + * Reserved. Must be zero. + */ + unsigned int reserved : 4 GNUNET_PACKED; +#else + #error byteorder undefined +#endif + + /** + * Flags (SYN, FIN, ACK, etc.) + */ + uint8_t flags; + + /** + * Window size. + */ + uint16_t window_size GNUNET_PACKED; + + /** + * Checksum. + */ + uint16_t crc GNUNET_PACKED; + + /** + * Urgent pointer. + */ + uint16_t urgent_pointer GNUNET_PACKED; +}; + + +/** + * UDP packet header. + */ +struct GNUNET_TUN_UdpHeader +{ + uint16_t source_port GNUNET_PACKED; + uint16_t destination_port GNUNET_PACKED; + uint16_t len GNUNET_PACKED; + uint16_t crc GNUNET_PACKED; +}; + + +/** + * DNS header. + */ +struct GNUNET_TUN_DnsHeader +{ + uint16_t id GNUNET_PACKED; + uint16_t flags GNUNET_PACKED; + uint16_t qdcount GNUNET_PACKED; + uint16_t ancount GNUNET_PACKED; + uint16_t nscount GNUNET_PACKED; + uint16_t arcount GNUNET_PACKED; +}; + +#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 + + +/** + * ICMP header. + */ +struct GNUNET_TUN_IcmpHeader { + uint8_t type; + uint8_t code; + uint16_t crc GNUNET_PACKED; + + union { + /** + * ICMP Echo (request/reply) + */ + struct { + uint16_t identifier GNUNET_PACKED; + uint16_t sequence_number GNUNET_PACKED; + } echo; + + /** + * ICMP Destination Unreachable (RFC 1191) + */ + struct ih_pmtu { + uint16_t empty GNUNET_PACKED; + uint16_t next_hop_mtu GNUNET_PACKED; + /* followed by original IP header + first 8 bytes of original IP datagram */ + } destination_unreachable; + + /** + * ICMP Redirect + */ + struct in_addr redirect_gateway_address GNUNET_PACKED; + + /** + * MTU for packets that are too big (IPv6). + */ + uint32_t packet_too_big_mtu GNUNET_PACKED; + + } quench; + +}; + + +GNUNET_NETWORK_STRUCT_END + + +/** + * Initialize an IPv4 header. + * + * @param ip header to initialize + * @param protocol protocol to use (i.e. IPPROTO_UDP) + * @param payload_length number of bytes of payload that follow (excluding IPv4 header) + * @param src source IP address to use + * @param dst destination IP address to use + */ +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 IPv6 header. + * + * @param ip header to initialize + * @param protocol protocol to use (i.e. IPPROTO_UDP) + * @param payload_length number of bytes of payload that follow (excluding IPv4 header) + * @param src source IP address to use + * @param dst destination IP address to use + */ +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); + +/** + * Calculate IPv4 TCP checksum. + * + * @param ip ipv4 header fully initialized + * @param tcp TCP header (initialized except for CRC) + * @param payload the TCP payload + * @param payload_length number of bytes of TCP payload + */ +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 IPv6 TCP checksum. + * + * @param ip ipv6 header fully initialized + * @param tcp TCP header (initialized except for CRC) + * @param payload the TCP payload + * @param payload_length number of bytes of TCP payload + */ +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 IPv4 UDP checksum. + * + * @param ip ipv4 header fully initialized + * @param udp UDP header (initialized except for CRC) + * @param payload the UDP payload + * @param payload_length number of bytes of UDP payload + */ +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 IPv6 UDP checksum. + * + * @param ip ipv6 header fully initialized + * @param udp UDP header (initialized except for CRC) + * @param payload the UDP payload + * @param payload_length number of bytes of UDP payload + */ +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 ICMP checksum. + * + * @param icmp IMCP header (initialized except for CRC) + * @param payload the ICMP payload + * @param payload_length number of bytes of ICMP payload + */ +void +GNUNET_TUN_calculate_icmp_checksum (struct GNUNET_TUN_IcmpHeader *icmp, + const void *payload, + uint16_t payload_length); + + +#endif |