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| -rw-r--r-- | src/include/net.h | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/include/net.h b/src/include/net.h new file mode 100644 index 0000000..2d87b4c --- /dev/null +++ b/src/include/net.h @@ -0,0 +1,140 @@ +#ifndef FR_NET_H +#define FR_NET_H +/* + * This program is is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2 of the + * License as published by the Free Software Foundation. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA + */ + +/** + * $Id$ + * @file include/net.h + * @brief Structures and functions for parsing raw network packets. + * + * @author Arran Cudbard-Bell <a.cudbardb@freeradius.org> + * @copyright 2014 Arran Cudbard-Bell <a.cudbardb@freeradius.org> + */ + +/* + * If we don't have libpcap, we still need an enumeration of link layers. + */ +#ifdef HAVE_LIBPCAP +# include <pcap.h> +#else +typedef enum { + DLT_RAW, + DLT_NULL, + DLT_LOOP, + DLT_EN10MB, + DLT_LINUX_SLL, + DLT_PFLOG +} fr_dlt; +#endif + +/* + * The number of bytes in an ethernet (MAC) address. + */ +#define ETHER_ADDR_LEN 6 + +/* + * Length of a DEC/Intel/Xerox or 802.3 Ethernet header. + * Note that some compilers may pad "struct ether_header" to + * a multiple of 4 *bytes, for example, so "sizeof (struct + * ether_header)" may not give the right answer. + * + * 6 Byte SRC, 6 Byte DST, 2 Byte Ether type, 4 Byte CVID, 4 Byte SVID + */ +#define ETHER_HDR_LEN 22 +#define IP_HDR_LEN 60 + +/* + * The number of bytes in a RADIUS packet header. + */ +#define RADIUS_HDR_LEN 20 + +/* + * RADIUS packet length. + * RFC 2865, Section 3., subsection 'length' says: + * " ... and maximum length is 4096." + */ +#define MAX_RADIUS_LEN 4096 +#define MIN_RADIUS_LEN 20 + + +#define IP_V(ip) (((ip)->ip_vhl & 0xf0) >> 4) +#define IP_HL(ip) ((ip)->ip_vhl & 0x0f) + +#define IP_VHL(v, hl) ((v & 0x0f) << 4) | (hl & 0x0f) + +#define I_DF 0x4000 //!< Dont fragment flag. +#define IP_MF 0x2000 //!< More fragments flag. +#define IP_OFFMASK 0x1fff //!< Mask for fragmenting bits. + +/* + * Structure of a DEC/Intel/Xerox or 802.3 Ethernet header. + */ +typedef struct CC_HINT(__packed__) ethernet_header { + uint8_t ether_dst[ETHER_ADDR_LEN]; + uint8_t ether_src[ETHER_ADDR_LEN]; + uint16_t ether_type; +} ethernet_header_t; + +/* + * Structure of an internet header, naked of options. + */ +typedef struct CC_HINT(__packed__) ip_header { + uint8_t ip_vhl; //!< Header length, version. + + uint8_t ip_tos; //!< Type of service. + uint16_t ip_len; //!< Total length. + uint16_t ip_id; //!< identification. + uint16_t ip_off; //!< Fragment offset field. + + uint8_t ip_ttl; //!< Time To Live. + uint8_t ip_p; //!< Protocol. + uint16_t ip_sum; //!< Checksum. + struct in_addr ip_src, ip_dst; //!< Src and Dst address +} ip_header_t; + +typedef struct CC_HINT(__packed__) ip_header6 { + uint32_t ip_vtcfl; //!< Version, traffic class, flow label. + uint16_t ip_len; //!< Payload length + + uint8_t ip_next; //!< Next header (protocol) + uint8_t ip_hopl; //!< IP Hop Limit + + struct in6_addr ip_src, ip_dst; //!< Src and Dst address +} ip_header6_t; + +/* + * UDP protocol header. + * Per RFC 768, September, 1981. + */ +typedef struct CC_HINT(__packed__) udp_header { + uint16_t src; //!< Source port. + uint16_t dst; //!< Destination port. + uint16_t len; //!< UDP length. + uint16_t checksum; //!< UDP checksum. +} udp_header_t; + +typedef struct CC_HINT(__packed__) radius_packet_t { + uint8_t code; + uint8_t id; + uint8_t length[2]; + uint8_t vector[AUTH_VECTOR_LEN]; + uint8_t data[]; +} radius_packet_t; + +uint16_t fr_udp_checksum(uint8_t const *data, uint16_t len, uint16_t checksum, + struct in_addr const src_addr, struct in_addr const dst_addr); +uint16_t fr_iph_checksum(uint8_t const *data, uint8_t ihl); +#endif /* FR_NET_H */ |