ethernet.h

Go to the documentation of this file.

#pragma once
/*
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  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: 493eab4730bfc49eed40df89083939fbe8208475 $
 *
 * @file protocols/ethernet/ethernet.h
 * @brief Structures and functions for parsing ethernet headers.
 *
 * @copyright 2017 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 */
#include <freeradius-devel/util/inet.h>
#include <stdint.h>
#include <stddef.h>
 
/*
 *      The number of bytes in an ethernet (MAC) address.
 */
#define ETHER_ADDR_LEN  6
 
/** Unpack the Priority Code Point from the TCI
 *
 */
#define VLAN_PCP_UNPACK(_vlan)          (((*(uint8_t const *)&(_vlan)->tag_control) & 0xe0) >> 5)
 
/** Unpack the Drop Eligible Indicator from the TCI
 *
 */
#define VLAN_DEI_UNPACK(_vlan)          (((*(uint8_t const *)&(_vlan)->tag_control) & 0x10) >> 4)
 
/** Unpack the VLAN ID from the TCI
 *
 */
#define VLAN_VID_UNPACK(_vlan)          ((htons((_vlan)->tag_control) & 0x0fff))
 
/** Pack the PCP (Priority Code Point) DEI (Drop Eligible Indicator) and VID (VLAN ID)
 *
 * Packs the PCP, DEI and VID into the TCI (Tag control information). Output will be a 16bit integer
 * in network byte order.
 *
 * @param[in] _pcp      Priority Code Point, a 3 bit value
 *                      indicating the relative priority of the packet.
 * @param[in] _dei      Drop eligible indicator.  Boolean indicating
 *                      whether this packet should be dropped in case of congestion.
 * @param[in] _vid      12 bit VLAN identifier.
 */
#define VLAN_TCI_PACK(_pcp, _dei, _vid) htons((((uint16_t)(_pcp) & 0xe0) << 13) | (((uint16_t)(_dei) & 0x01) << 12) | ((_vid) & 0x0fff))
 
/** A VLAN header
 *
 * Represents a single layer of 802.1Q or QinQ tagging.
 */
typedef struct CC_HINT(__packed__) {
        uint16_t        tag_type;               //!< Tag type.  One of (0x8100 - CVLAN, 0x9100,
                                                ///< 0x9200, 0x9300 - SVLAN).
        uint16_t        tag_control;            //!< - 3 bits priority.
                                                ///< - 1 bit DEI.
                                                ///< - 12 bits VID.
} vlan_header_t;
 
/** Structure of a DEC/Intel/Xerox or 802.3 Ethernet header
 *
 */
typedef struct CC_HINT(__packed__) {
        uint8_t         dst_addr[ETHER_ADDR_LEN];
        uint8_t         src_addr[ETHER_ADDR_LEN];
        uint16_t        ether_type;
} ethernet_header_t;
 
/** Src/dst link layer information
 *
 */
typedef struct {
        fr_ethernet_t   src_addr;
        fr_ethernet_t   dst_addr;
        uint16_t        ether_type;             //!< Ether type.  Usually 0x0800 (IPv4) 0x086DD (IPv6).
 
        uint16_t        cvlan_tpid;             //!< CVLAN tag type.  If 0, no CVLAN/SVLAN present.
        uint8_t         cvlan_pcp;              //!< CVLAN priority code point 0-6.
        uint8_t         cvlan_dei;              //!< CVLAN drop eligible indicator.
        uint16_t        cvlan_vid;              //!< CVLAN vlan ID.
 
        uint16_t        svlan_tpid;             //!< SVLAN tag type.  If 0, no SVLAN present.
        uint8_t         svlan_pcp;              //!< SVLAN priority code point 0-6.
        uint8_t         svlan_dei;              //!< SVLAN drop eligible indicator.
        uint16_t        svlan_vid;              //!< SVLAN vlan ID.
 
        size_t          payload_len;            //!< Remaining bytes after the ethernet header has been parsed.
} fr_ethernet_proto_ctx_t;
 
/** Protocol options for ethernet
 *
 */
typedef enum {
        PROTO_OPT_ETHERNET_SVLAN_TPID = 0,      //!< Outer VLAN tag type.
        PROTO_OPT_ETHERNET_SVLAN_PCP,           //!< Outer VLAN priority code point.
        PROTO_OPT_ETHERNET_SVLAN_DEI,           //!< Outer VLAN drop eligible indicator.
        PROTO_OPT_ETHERNET_SVLAN_VID,           //!< Outer VLAN ID.
        PROTO_OPT_ETHERNET_CVLAN_TPID,          //!< Inner VLAN tag type.
        PROTO_OPT_ETHERNET_CVLAN_PCP,           //!< Inner VLAN priority code point.
        PROTO_OPT_ETHERNET_CVLAN_DEI,           //!< Inner VLAN drop eligible indicator.
        PROTO_OPT_ETHERNET_CVLAN_VID            //!< Inner VLAN ID.
} fr_ethernet_options_t;