bfd.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: 601b9e9b8427485932f37823b6d8c349dd308342 $
 *
 * @file protocols/bfd/bfd.h
 * @brief Structures and prototypes for base BFD functionality.
 *
 * @copyright 2023 Network RADIUS SAS (legal@networkradius.com)
 */
#include <freeradius-devel/util/rand.h>
#include <freeradius-devel/util/log.h>
#include <freeradius-devel/util/pair.h>
#include <freeradius-devel/util/md5.h>
#include <freeradius-devel/util/sha1.h>
#include <freeradius-devel/util/dbuff.h>
 
typedef enum bfd_session_state_t {
        BFD_STATE_ADMIN_DOWN = 0,
        BFD_STATE_DOWN,
        BFD_STATE_INIT,
        BFD_STATE_UP
} bfd_session_state_t;
 
typedef enum bfd_diag_t {
        BFD_DIAG_NONE = 0,
        BFD_CTRL_EXPIRED,
        BFD_ECHO_FAILED,
        BFD_NEIGHBOR_DOWN,
        BFD_FORWARD_PLANE_RESET,
        BFD_PATH_DOWN,
        BFD_CONCATENATED_PATH_DOWN,
        BFD_ADMIN_DOWN,
        BFD_REVERSE_CONCAT_PATH_DOWN
} bfd_diag_t;
 
typedef enum bfd_auth_type_t {
        BFD_AUTH_RESERVED = 0,
        BFD_AUTH_SIMPLE,
        BFD_AUTH_KEYED_MD5,
        BFD_AUTH_MET_KEYED_MD5,
        BFD_AUTH_KEYED_SHA1,
        BFD_AUTH_MET_KEYED_SHA1,
} bfd_auth_type_t;
 
#define BFD_AUTH_INVALID (BFD_AUTH_MET_KEYED_SHA1 + 1)
 
typedef struct {
        uint8_t         auth_type;
        uint8_t         auth_len;
        uint8_t         key_id;
} __attribute__ ((packed)) bfd_auth_basic_t;
 
 
typedef struct {
        uint8_t         auth_type;
        uint8_t         auth_len;
        uint8_t         key_id;
        uint8_t         password[16];
} __attribute__ ((packed)) bfd_auth_simple_t;
 
typedef struct {
        uint8_t         auth_type;
        uint8_t         auth_len;
        uint8_t         key_id;
        uint8_t         reserved;
        uint32_t        sequence_no;
        uint8_t         digest[MD5_DIGEST_LENGTH];
} __attribute__ ((packed)) bfd_auth_md5_t;
 
typedef struct {
        uint8_t         auth_type;
        uint8_t         auth_len;
        uint8_t         key_id;
        uint8_t         reserved;
        uint32_t        sequence_no;
        uint8_t         digest[SHA1_DIGEST_LENGTH];
} __attribute__ ((packed)) bfd_auth_sha1_t;
 
typedef union bfd_auth_t {
        union {
                bfd_auth_basic_t        basic;
                bfd_auth_simple_t       password;
                bfd_auth_md5_t          md5;
                bfd_auth_sha1_t         sha1;
        };
} __attribute__ ((packed)) bfd_auth_t;
 
 
/*
 *      A packet
 */
typedef struct {
#ifdef WORDS_BIGENDIAN
        unsigned int    version : 3;
        unsigned int    diag : 5;
        unsigned int    state : 2;
        unsigned int    poll : 1;
        unsigned int    final : 1;
        unsigned int    control_plane_independent : 1;
        unsigned int    auth_present : 1;
        unsigned int    demand : 1;
        unsigned int    multipoint : 1;
#else
        unsigned int    diag : 5;
        unsigned int    version : 3;
 
        unsigned int    multipoint : 1;
        unsigned int    demand : 1;
        unsigned int    auth_present : 1;
        unsigned int    control_plane_independent : 1;
        unsigned int    final : 1;
        unsigned int    poll : 1;
        unsigned int    state : 2;
#endif
        uint8_t         detect_multi;
        uint8_t         length;
        uint32_t        my_disc;
        uint32_t        your_disc;
        uint32_t        desired_min_tx_interval;
        uint32_t        required_min_rx_interval;
        uint32_t        min_echo_rx_interval;
        bfd_auth_t      auth;
} __attribute__ ((packed)) bfd_packet_t;
 
#define FR_BFD_HEADER_LENGTH (24)
 
typedef enum {
        FR_BFD_ADMIN_DOWN,
        FR_BFD_DOWN,
        FR_BFD_INIT,
        FR_BFD_UP,
} fr_bfd_packet_code_t;
#define FR_BFD_CODE_MAX (4)
 
extern char const *fr_bfd_packet_names[FR_BFD_CODE_MAX];
#define FR_BFD_PACKET_CODE_VALID(_code) (_code < FR_BFD_CODE_MAX)
 
typedef struct {
        TALLOC_CTX              *tmp_ctx;               //!< for temporary things cleaned up during decoding
        char const              *secret;                //!< shared secret.  MUST be talloc'd
} fr_bfd_ctx_t;
 
ssize_t         fr_bfd_encode(uint8_t *packet, size_t packet_len,  uint8_t const *original,
                              char const *secret,  size_t secret_len, fr_pair_list_t *vps);
 
ssize_t         fr_bfd_decode(TALLOC_CTX *ctx, fr_pair_list_t *out,
                              uint8_t const *packet, size_t packet_len,
                              char const *secret, size_t secret_len);
 
bool            fr_bfd_packet_ok(char const **err, uint8_t const *packet, size_t packet_len);
 
int     fr_bfd_global_init(void);
void    fr_bfd_global_free(void);
 
extern fr_table_num_ordered_t const bfd_auth_type_table[];
extern size_t const bfd_auth_type_table_len;