* @brief standard TCP/IP network structs and IP checksum calculations for TUN interaction
* @author Philipp Toelke
* @author Christian Grothoff
- *
- * TODO:
- * - currently does not follow our naming conventions
*/
-#ifndef TCPIP_TUN_H
-#define TCPIP_TUN_H
+#ifndef GNUNET_TUN_LIB_H
+#define GNUNET_TUN_LIB_H
-#include "platform.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 tun_header
+struct GNUNET_TUN_Layer2PacketHeader
{
/**
* Some flags (unused).
*/
- uint16_t flags;
+ uint16_t flags GNUNET_PACKED;
/**
* Here we get an ETH_P_-number.
*/
- uint16_t proto;
+ uint16_t proto GNUNET_PACKED;
};
/**
* Standard IPv4 header.
*/
-struct ip4_header
+struct GNUNET_TUN_IPv4Header
{
- unsigned header_length:4 GNUNET_PACKED;
- unsigned version:4 GNUNET_PACKED;
+#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 flags:3 GNUNET_PACKED;
- unsigned fragmentation_offset:13 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;
-};
+} GNUNET_GCC_STRUCT_LAYOUT;
+
/**
* Standard IPv6 header.
*/
-struct ip6_header
+struct GNUNET_TUN_IPv6Header
{
- unsigned traffic_class_h:4 GNUNET_PACKED;
- unsigned version:4 GNUNET_PACKED;
- unsigned traffic_class_l:4 GNUNET_PACKED;
- unsigned flow_label:20 GNUNET_PACKED;
+#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;
-};
+} GNUNET_GCC_STRUCT_LAYOUT;
-#define TCP_FLAG_SYN 2
/**
- * TCP packet header (FIXME: rename!)
+ * TCP packet header.
*/
-struct tcp_packet
+struct GNUNET_TUN_TcpHeader
{
- unsigned spt:16 GNUNET_PACKED;
- unsigned dpt:16 GNUNET_PACKED;
- unsigned seq:32 GNUNET_PACKED;
- unsigned ack:32 GNUNET_PACKED;
- unsigned off:4 GNUNET_PACKED;
- unsigned rsv:4 GNUNET_PACKED;
- unsigned flg:8 GNUNET_PACKED;
- unsigned wsz:16 GNUNET_PACKED;
- unsigned crc:16 GNUNET_PACKED;
- unsigned urg:16 GNUNET_PACKED;
-};
+ 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;
+} GNUNET_GCC_STRUCT_LAYOUT;
+
/**
- * UDP packet header (FIXME: rename!)
+ * UDP packet header.
*/
-struct udp_packet
+struct GNUNET_TUN_UdpHeader
{
- uint16_t spt GNUNET_PACKED;
- uint16_t dpt GNUNET_PACKED;
+ 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 dns_header
+struct GNUNET_TUN_DnsHeader
{
uint16_t id GNUNET_PACKED;
uint16_t flags 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