Adding upstream version 8.4.4.upstream/8.4.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 843 insertions, 0 deletions

diff --git a/bfdd/bfd.h b/bfdd/bfd.h
new file mode 100644
index 0000000..a5881cd
--- /dev/null
+++ b/bfdd/bfd.h
@@ -0,0 +1,843 @@
+/*********************************************************************
+ * Copyright 2014,2015,2016,2017 Cumulus Networks, Inc.  All rights reserved.
+ *
+ * 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; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * bfd.h: implements the BFD protocol.
+ */
+
+#ifndef _BFD_H_
+#define _BFD_H_
+
+#include <netinet/in.h>
+
+#include <stdbool.h>
+#include <stdarg.h>
+#include <stdint.h>
+
+#include "lib/hash.h"
+#include "lib/libfrr.h"
+#include "lib/qobj.h"
+#include "lib/queue.h"
+#include "lib/vrf.h"
+
+#include "bfdctl.h"
+
+#ifdef BFD_DEBUG
+#define BFDD_JSON_CONV_OPTIONS (JSON_C_TO_STRING_PRETTY)
+#else
+#define BFDD_JSON_CONV_OPTIONS (0)
+#endif
+
+DECLARE_MGROUP(BFDD);
+DECLARE_MTYPE(BFDD_CONTROL);
+DECLARE_MTYPE(BFDD_NOTIFICATION);
+
+struct bfd_timers {
+	uint32_t desired_min_tx;
+	uint32_t required_min_rx;
+	uint32_t required_min_echo;
+};
+
+struct bfd_discrs {
+	uint32_t my_discr;
+	uint32_t remote_discr;
+};
+
+/*
+ * Format of control packet.  From section 4)
+ */
+struct bfd_pkt {
+	union {
+		uint32_t byteFields;
+		struct {
+			uint8_t diag;
+			uint8_t flags;
+			uint8_t detect_mult;
+			uint8_t len;
+		};
+	};
+	struct bfd_discrs discrs;
+	struct bfd_timers timers;
+};
+
+/*
+ * Format of Echo packet.
+ */
+struct bfd_echo_pkt {
+	union {
+		uint32_t byteFields;
+		struct {
+			uint8_t ver;
+			uint8_t len;
+			uint16_t reserved;
+		};
+	};
+	uint32_t my_discr;
+	uint64_t time_sent_sec;
+	uint64_t time_sent_usec;
+};
+
+
+/* Macros for manipulating control packets */
+#define BFD_VERMASK 0x03
+#define BFD_DIAGMASK 0x1F
+#define BFD_GETVER(diag) ((diag >> 5) & BFD_VERMASK)
+#define BFD_SETVER(diag, val) ((diag) |= (val & BFD_VERMASK) << 5)
+#define BFD_VERSION 1
+#define BFD_PBIT 0x20
+#define BFD_FBIT 0x10
+#define BFD_CBIT 0x08
+#define BFD_ABIT 0x04
+#define BFD_DEMANDBIT 0x02
+#define BFD_SETDEMANDBIT(flags, val)                                           \
+	{                                                                      \
+		if ((val))                                                     \
+			flags |= BFD_DEMANDBIT;                                \
+	}
+#define BFD_SETPBIT(flags, val)                                                \
+	{                                                                      \
+		if ((val))                                                     \
+			flags |= BFD_PBIT;                                     \
+	}
+#define BFD_GETPBIT(flags) (flags & BFD_PBIT)
+#define BFD_SETFBIT(flags, val)                                                \
+	{                                                                      \
+		if ((val))                                                     \
+			flags |= BFD_FBIT;                                     \
+	}
+#define BFD_GETFBIT(flags) (flags & BFD_FBIT)
+#define BFD_SETSTATE(flags, val)                                               \
+	{                                                                      \
+		if ((val))                                                     \
+			flags |= (val & 0x3) << 6;                             \
+	}
+#define BFD_GETSTATE(flags) ((flags >> 6) & 0x3)
+#define BFD_SETCBIT(flags, val)                                                \
+	{                                                                      \
+		if ((val))                                                     \
+			flags |= val;                                          \
+	}
+#define BFD_GETCBIT(flags) (flags & BFD_FBIT)
+#define BFD_ECHO_VERSION 1
+#define BFD_ECHO_PKT_LEN sizeof(struct bfd_echo_pkt)
+
+enum bfd_diagnosticis {
+	BD_OK = 0,
+	/* Control Detection Time Expired. */
+	BD_CONTROL_EXPIRED = 1,
+	/* Echo Function Failed. */
+	BD_ECHO_FAILED = 2,
+	/* Neighbor Signaled Session Down. */
+	BD_NEIGHBOR_DOWN = 3,
+	/* Forwarding Plane Reset. */
+	BD_FORWARDING_RESET = 4,
+	/* Path Down. */
+	BD_PATH_DOWN = 5,
+	/* Concatenated Path Down. */
+	BD_CONCATPATH_DOWN = 6,
+	/* Administratively Down. */
+	BD_ADMIN_DOWN = 7,
+	/* Reverse Concatenated Path Down. */
+	BD_REVCONCATPATH_DOWN = 8,
+	/* 9..31: reserved. */
+};
+
+/* BFD session flags */
+enum bfd_session_flags {
+	BFD_SESS_FLAG_NONE = 0,
+	BFD_SESS_FLAG_ECHO = 1 << 0,	/* BFD Echo functionality */
+	BFD_SESS_FLAG_ECHO_ACTIVE = 1 << 1, /* BFD Echo Packets are being sent
+					     * actively
+					     */
+	BFD_SESS_FLAG_MH = 1 << 2,	  /* BFD Multi-hop session */
+	BFD_SESS_FLAG_IPV6 = 1 << 4,	/* BFD IPv6 session */
+	BFD_SESS_FLAG_SEND_EVT_ACTIVE = 1 << 5, /* send event timer active */
+	BFD_SESS_FLAG_SEND_EVT_IGNORE = 1 << 6, /* ignore send event when timer
+						 * expires
+						 */
+	BFD_SESS_FLAG_SHUTDOWN = 1 << 7,	/* disable BGP peer function */
+	BFD_SESS_FLAG_CONFIG = 1 << 8, /* Session configured with bfd NB API */
+	BFD_SESS_FLAG_CBIT = 1 << 9,   /* CBIT is set */
+	BFD_SESS_FLAG_PASSIVE = 1 << 10, /* Passive mode */
+	BFD_SESS_FLAG_MAC_SET = 1 << 11, /* MAC of peer known */
+};
+
+/*
+ * BFD session hash key.
+ *
+ * This structure must not have any padding bytes because their value is
+ * unspecified after the struct assignment. Even when all fields of two keys
+ * are the same, if the padding bytes are different, then the calculated hash
+ * value is different, and the hash lookup will fail.
+ *
+ * Currently, the structure fields are correctly aligned, and the "packed"
+ * attribute is added as a precaution. "family" and "mhop" fields are two-bytes
+ * to eliminate unaligned memory access to "peer" and "local".
+ */
+struct bfd_key {
+	uint16_t family;
+	uint16_t mhop;
+	struct in6_addr peer;
+	struct in6_addr local;
+	char ifname[INTERFACE_NAMSIZ];
+	char vrfname[VRF_NAMSIZ];
+} __attribute__((packed));
+
+struct bfd_session_stats {
+	uint64_t rx_ctrl_pkt;
+	uint64_t tx_ctrl_pkt;
+	uint64_t rx_echo_pkt;
+	uint64_t tx_echo_pkt;
+	uint64_t session_up;
+	uint64_t session_down;
+	uint64_t znotification;
+};
+
+/**
+ * BFD session profile to override default configurations.
+ */
+struct bfd_profile {
+	/** Profile name. */
+	char name[64];
+
+	/** Session detection multiplier. */
+	uint8_t detection_multiplier;
+	/** Desired transmission interval (in microseconds). */
+	uint32_t min_tx;
+	/** Minimum required receive interval (in microseconds). */
+	uint32_t min_rx;
+	/** Administrative state. */
+	bool admin_shutdown;
+	/** Passive mode. */
+	bool passive;
+	/** Minimum expected TTL value. */
+	uint8_t minimum_ttl;
+
+	/** Echo mode (only applies to single hop). */
+	bool echo_mode;
+	/** Desired echo transmission interval (in microseconds). */
+	uint32_t min_echo_tx;
+	/** Minimum required echo receive interval (in microseconds). */
+	uint32_t min_echo_rx;
+
+	/** Profile list entry. */
+	TAILQ_ENTRY(bfd_profile) entry;
+};
+
+/** Profile list type. */
+TAILQ_HEAD(bfdproflist, bfd_profile);
+
+/* bfd_session shortcut label forwarding. */
+struct peer_label;
+
+struct bfd_config_timers {
+	uint32_t desired_min_tx;
+	uint32_t required_min_rx;
+	uint32_t desired_min_echo_tx;
+	uint32_t required_min_echo_rx;
+};
+
+#define BFD_RTT_SAMPLE 8
+
+/*
+ * Session state information
+ */
+struct bfd_session {
+
+	/* protocol state per RFC 5880*/
+	uint8_t ses_state;
+	struct bfd_discrs discrs;
+	uint8_t local_diag;
+	uint8_t demand_mode;
+	uint8_t detect_mult;
+	uint8_t remote_detect_mult;
+	uint8_t mh_ttl;
+	uint8_t remote_cbit;
+
+	/** BFD profile name. */
+	char *profile_name;
+	/** BFD pre configured profile. */
+	struct bfd_profile *profile;
+	/** BFD peer configuration (without profile). */
+	struct bfd_profile peer_profile;
+
+	/* Timers */
+	struct bfd_config_timers timers;
+	struct bfd_timers cur_timers;
+	uint64_t detect_TO;
+	struct thread *echo_recvtimer_ev;
+	struct thread *recvtimer_ev;
+	uint64_t xmt_TO;
+	uint64_t echo_xmt_TO;
+	struct thread *xmttimer_ev;
+	struct thread *echo_xmttimer_ev;
+	uint64_t echo_detect_TO;
+
+	/* software object state */
+	uint8_t polling;
+
+	/* This and the localDiscr are the keys to state info */
+	struct bfd_key key;
+	struct peer_label *pl;
+
+	struct bfd_dplane_ctx *bdc;
+	struct sockaddr_any local_address;
+	uint8_t peer_hw_addr[ETH_ALEN];
+	struct interface *ifp;
+	struct vrf *vrf;
+
+	int sock;
+
+	/* BFD session flags */
+	enum bfd_session_flags flags;
+
+	struct bfd_session_stats stats;
+
+	struct timeval uptime;   /* last up time */
+	struct timeval downtime; /* last down time */
+
+	/* Remote peer data (for debugging mostly) */
+	uint8_t remote_diag;
+	struct bfd_timers remote_timers;
+
+	uint64_t refcount; /* number of pointers referencing this. */
+
+	uint8_t rtt_valid;	    /* number of valid samples */
+	uint8_t rtt_index;	    /* last index added */
+	uint64_t rtt[BFD_RTT_SAMPLE]; /* RRT in usec for echo to be looped */
+};
+
+struct peer_label {
+	TAILQ_ENTRY(peer_label) pl_entry;
+
+	struct bfd_session *pl_bs;
+	char pl_label[MAXNAMELEN];
+};
+TAILQ_HEAD(pllist, peer_label);
+
+struct bfd_diag_str_list {
+	const char *str;
+	int type;
+};
+
+struct bfd_state_str_list {
+	const char *str;
+	int type;
+};
+
+struct bfd_session_observer {
+	struct bfd_session *bso_bs;
+	char bso_entryname[MAXNAMELEN];
+	struct prefix bso_addr;
+
+	TAILQ_ENTRY(bfd_session_observer) bso_entry;
+};
+TAILQ_HEAD(obslist, bfd_session_observer);
+
+
+/* States defined per 4.1 */
+#define PTM_BFD_ADM_DOWN 0
+#define PTM_BFD_DOWN 1
+#define PTM_BFD_INIT 2
+#define PTM_BFD_UP 3
+
+
+/* Various constants */
+/* Retrieved from ptm_timer.h from Cumulus PTM sources. */
+#define BFD_DEF_DEMAND 0
+#define BFD_DEFDETECTMULT 3
+#define BFD_DEFDESIREDMINTX (300 * 1000) /* microseconds. */
+#define BFD_DEFREQUIREDMINRX (300 * 1000) /* microseconds. */
+#define BFD_DEF_DES_MIN_ECHO_TX (50 * 1000) /* microseconds. */
+#define BFD_DEF_REQ_MIN_ECHO_RX (50 * 1000) /* microseconds. */
+#define BFD_DEF_SLOWTX (1000 * 1000) /* microseconds. */
+/** Minimum multi hop TTL. */
+#define BFD_DEF_MHOP_TTL 254
+#define BFD_PKT_LEN 24 /* Length of control packet */
+#define BFD_TTL_VAL 255
+#define BFD_RCV_TTL_VAL 1
+#define BFD_TOS_VAL 0xC0
+#define BFD_PKT_INFO_VAL 1
+#define BFD_IPV6_PKT_INFO_VAL 1
+#define BFD_IPV6_ONLY_VAL 1
+#define BFD_SRCPORTINIT 49152
+#define BFD_SRCPORTMAX 65535
+#define BFD_DEFDESTPORT 3784
+#define BFD_DEF_ECHO_PORT 3785
+#define BFD_DEF_MHOP_DEST_PORT 4784
+
+/*
+ * control.c
+ *
+ * Daemon control code to speak with local consumers.
+ */
+
+/* See 'bfdctrl.h' for client protocol definitions. */
+
+struct bfd_control_buffer {
+	size_t bcb_left;
+	size_t bcb_pos;
+	union {
+		struct bfd_control_msg *bcb_bcm;
+		uint8_t *bcb_buf;
+	};
+};
+
+struct bfd_control_queue {
+	TAILQ_ENTRY(bfd_control_queue) bcq_entry;
+
+	struct bfd_control_buffer bcq_bcb;
+};
+TAILQ_HEAD(bcqueue, bfd_control_queue);
+
+struct bfd_notify_peer {
+	TAILQ_ENTRY(bfd_notify_peer) bnp_entry;
+
+	struct bfd_session *bnp_bs;
+};
+TAILQ_HEAD(bnplist, bfd_notify_peer);
+
+struct bfd_control_socket {
+	TAILQ_ENTRY(bfd_control_socket) bcs_entry;
+
+	int bcs_sd;
+	struct thread *bcs_ev;
+	struct thread *bcs_outev;
+	struct bcqueue bcs_bcqueue;
+
+	/* Notification data */
+	uint64_t bcs_notify;
+	struct bnplist bcs_bnplist;
+
+	enum bc_msg_version bcs_version;
+	enum bc_msg_type bcs_type;
+
+	/* Message buffering */
+	struct bfd_control_buffer bcs_bin;
+	struct bfd_control_buffer *bcs_bout;
+};
+TAILQ_HEAD(bcslist, bfd_control_socket);
+
+int control_init(const char *path);
+void control_shutdown(void);
+int control_notify(struct bfd_session *bs, uint8_t notify_state);
+int control_notify_config(const char *op, struct bfd_session *bs);
+void control_accept(struct thread *t);
+
+
+/*
+ * bfdd.c
+ *
+ * Daemon specific code.
+ */
+struct bfd_vrf_global {
+	int bg_shop;
+	int bg_mhop;
+	int bg_shop6;
+	int bg_mhop6;
+	int bg_echo;
+	int bg_echov6;
+	struct vrf *vrf;
+
+	struct thread *bg_ev[6];
+};
+
+/* Forward declaration of data plane context struct. */
+struct bfd_dplane_ctx;
+TAILQ_HEAD(dplane_queue, bfd_dplane_ctx);
+
+struct bfd_global {
+	int bg_csock;
+	struct thread *bg_csockev;
+	struct bcslist bg_bcslist;
+
+	struct pllist bg_pllist;
+
+	struct obslist bg_obslist;
+
+	struct zebra_privs_t bfdd_privs;
+
+	/**
+	 * Daemon is exit()ing? Use this to avoid actions that expect a
+	 * running system or to avoid unnecessary operations when quitting.
+	 */
+	bool bg_shutdown;
+
+	/* Distributed BFD items. */
+	bool bg_use_dplane;
+	int bg_dplane_sock;
+	struct thread *bg_dplane_sockev;
+	struct dplane_queue bg_dplaneq;
+
+	/* Debug options. */
+	/* Show distributed BFD debug messages. */
+	bool debug_dplane;
+	/* Show all peer state changes events. */
+	bool debug_peer_event;
+	/*
+	 * Show zebra message exchanges:
+	 * - Interface add/delete.
+	 * - Local address add/delete.
+	 * - VRF add/delete.
+	 */
+	bool debug_zebra;
+	/*
+	 * Show network level debug information:
+	 * - Echo packets without session.
+	 * - Unavailable peer sessions.
+	 * - Network system call failures.
+	 */
+	bool debug_network;
+};
+
+extern struct bfd_global bglobal;
+extern const struct bfd_diag_str_list diag_list[];
+extern const struct bfd_state_str_list state_list[];
+
+void socket_close(int *s);
+
+
+/*
+ * config.c
+ *
+ * Contains the code related with loading/reloading configuration.
+ */
+int parse_config(const char *fname);
+int config_request_add(const char *jsonstr);
+int config_request_del(const char *jsonstr);
+char *config_response(const char *status, const char *error);
+char *config_notify(struct bfd_session *bs);
+char *config_notify_config(const char *op, struct bfd_session *bs);
+
+typedef int (*bpc_handle)(struct bfd_peer_cfg *, void *arg);
+int config_notify_request(struct bfd_control_socket *bcs, const char *jsonstr,
+			  bpc_handle bh);
+
+struct peer_label *pl_new(const char *label, struct bfd_session *bs);
+struct peer_label *pl_find(const char *label);
+void pl_free(struct peer_label *pl);
+
+
+/*
+ * logging - alias to zebra log
+ */
+#define zlog_fatal(msg, ...)                                                   \
+	do {                                                                   \
+		zlog_err(msg, ##__VA_ARGS__);                                  \
+		assert(!msg);                                                  \
+		abort();                                                       \
+	} while (0)
+
+
+/*
+ * bfd_packet.c
+ *
+ * Contains the code related with receiving/seding, packing/unpacking BFD data.
+ */
+int bp_set_ttlv6(int sd, uint8_t value);
+int bp_set_ttl(int sd, uint8_t value);
+int bp_set_tosv6(int sd, uint8_t value);
+int bp_set_tos(int sd, uint8_t value);
+int bp_bind_dev(int sd, const char *dev);
+
+int bp_udp_shop(const struct vrf *vrf);
+int bp_udp_mhop(const struct vrf *vrf);
+int bp_udp6_shop(const struct vrf *vrf);
+int bp_udp6_mhop(const struct vrf *vrf);
+int bp_peer_socket(const struct bfd_session *bs);
+int bp_peer_socketv6(const struct bfd_session *bs);
+int bp_echo_socket(const struct vrf *vrf);
+int bp_echov6_socket(const struct vrf *vrf);
+
+void ptm_bfd_snd(struct bfd_session *bfd, int fbit);
+void ptm_bfd_echo_snd(struct bfd_session *bfd);
+void ptm_bfd_echo_fp_snd(struct bfd_session *bfd);
+
+void bfd_recv_cb(struct thread *t);
+
+
+/*
+ * event.c
+ *
+ * Contains the code related with event loop.
+ */
+typedef void (*bfd_ev_cb)(struct thread *t);
+
+void bfd_recvtimer_update(struct bfd_session *bs);
+void bfd_echo_recvtimer_update(struct bfd_session *bs);
+void bfd_xmttimer_update(struct bfd_session *bs, uint64_t jitter);
+void bfd_echo_xmttimer_update(struct bfd_session *bs, uint64_t jitter);
+
+void bfd_xmttimer_delete(struct bfd_session *bs);
+void bfd_echo_xmttimer_delete(struct bfd_session *bs);
+void bfd_recvtimer_delete(struct bfd_session *bs);
+void bfd_echo_recvtimer_delete(struct bfd_session *bs);
+
+void bfd_recvtimer_assign(struct bfd_session *bs, bfd_ev_cb cb, int sd);
+void bfd_echo_recvtimer_assign(struct bfd_session *bs, bfd_ev_cb cb, int sd);
+void bfd_xmttimer_assign(struct bfd_session *bs, bfd_ev_cb cb);
+void bfd_echo_xmttimer_assign(struct bfd_session *bs, bfd_ev_cb cb);
+
+
+/*
+ * bfd.c
+ *
+ * BFD protocol specific code.
+ */
+int bfd_session_enable(struct bfd_session *bs);
+void bfd_session_disable(struct bfd_session *bs);
+struct bfd_session *ptm_bfd_sess_new(struct bfd_peer_cfg *bpc);
+int ptm_bfd_sess_del(struct bfd_peer_cfg *bpc);
+void ptm_bfd_sess_dn(struct bfd_session *bfd, uint8_t diag);
+void ptm_bfd_sess_up(struct bfd_session *bfd);
+void ptm_bfd_echo_stop(struct bfd_session *bfd);
+void ptm_bfd_echo_start(struct bfd_session *bfd);
+void ptm_bfd_xmt_TO(struct bfd_session *bfd, int fbit);
+void ptm_bfd_start_xmt_timer(struct bfd_session *bfd, bool is_echo);
+struct bfd_session *ptm_bfd_sess_find(struct bfd_pkt *cp,
+				      struct sockaddr_any *peer,
+				      struct sockaddr_any *local,
+				      struct interface *ifp,
+				      vrf_id_t vrfid,
+				      bool is_mhop);
+
+struct bfd_session *bs_peer_find(struct bfd_peer_cfg *bpc);
+int bfd_session_update_label(struct bfd_session *bs, const char *nlabel);
+void bfd_set_polling(struct bfd_session *bs);
+void bs_state_handler(struct bfd_session *bs, int nstate);
+void bs_echo_timer_handler(struct bfd_session *bs);
+void bs_final_handler(struct bfd_session *bs);
+void bs_set_slow_timers(struct bfd_session *bs);
+const char *satostr(const struct sockaddr_any *sa);
+const char *diag2str(uint8_t diag);
+int strtosa(const char *addr, struct sockaddr_any *sa);
+void integer2timestr(uint64_t time, char *buf, size_t buflen);
+const char *bs_to_string(const struct bfd_session *bs);
+
+int bs_observer_add(struct bfd_session *bs);
+void bs_observer_del(struct bfd_session_observer *bso);
+
+void bs_to_bpc(struct bfd_session *bs, struct bfd_peer_cfg *bpc);
+
+void gen_bfd_key(struct bfd_key *key, struct sockaddr_any *peer,
+		 struct sockaddr_any *local, bool mhop, const char *ifname,
+		 const char *vrfname);
+struct bfd_session *bfd_session_new(void);
+struct bfd_session *bs_registrate(struct bfd_session *bs);
+void bfd_session_free(struct bfd_session *bs);
+const struct bfd_session *bfd_session_next(const struct bfd_session *bs,
+					   bool mhop);
+void bfd_sessions_remove_manual(void);
+void bfd_profiles_remove(void);
+void bfd_rtt_init(struct bfd_session *bfd);
+
+/**
+ * Set the BFD session echo state.
+ *
+ * \param bs the BFD session.
+ * \param echo the echo operational state.
+ */
+void bfd_set_echo(struct bfd_session *bs, bool echo);
+
+/**
+ * Set the BFD session functional state.
+ *
+ * \param bs the BFD session.
+ * \param shutdown the operational value.
+ */
+void bfd_set_shutdown(struct bfd_session *bs, bool shutdown);
+
+/**
+ * Set the BFD session passive mode.
+ *
+ * \param bs the BFD session.
+ * \param passive the passive mode.
+ */
+void bfd_set_passive_mode(struct bfd_session *bs, bool passive);
+
+/**
+ * Picks the BFD session configuration from the appropriated source:
+ * if using the default peer configuration prefer profile (if it exists),
+ * otherwise use session.
+ *
+ * \param bs the BFD session.
+ */
+void bfd_session_apply(struct bfd_session *bs);
+
+/* BFD hash data structures interface */
+void bfd_initialize(void);
+void bfd_shutdown(void);
+void bfd_vrf_init(void);
+void bfd_vrf_terminate(void);
+struct bfd_vrf_global *bfd_vrf_look_by_session(struct bfd_session *bfd);
+struct bfd_session *bfd_id_lookup(uint32_t id);
+struct bfd_session *bfd_key_lookup(struct bfd_key key);
+
+struct bfd_session *bfd_id_delete(uint32_t id);
+struct bfd_session *bfd_key_delete(struct bfd_key key);
+
+bool bfd_id_insert(struct bfd_session *bs);
+bool bfd_key_insert(struct bfd_session *bs);
+
+typedef void (*hash_iter_func)(struct hash_bucket *hb, void *arg);
+void bfd_id_iterate(hash_iter_func hif, void *arg);
+void bfd_key_iterate(hash_iter_func hif, void *arg);
+
+unsigned long bfd_get_session_count(void);
+
+/* Export callback functions for `event.c`. */
+extern struct thread_master *master;
+
+void bfd_recvtimer_cb(struct thread *t);
+void bfd_echo_recvtimer_cb(struct thread *t);
+void bfd_xmt_cb(struct thread *t);
+void bfd_echo_xmt_cb(struct thread *t);
+
+extern struct in6_addr zero_addr;
+
+/**
+ * Creates a new profile entry and insert into the global list.
+ *
+ * \param name the BFD profile name.
+ *
+ * \returns `NULL` if it already exists otherwise the new entry.
+ */
+struct bfd_profile *bfd_profile_new(const char *name);
+
+/**
+ * Search for configured BFD profiles (profile name is case insensitive).
+ *
+ * \param name the BFD profile name.
+ *
+ * \returns `NULL` if it doesn't exist otherwise the entry.
+ */
+struct bfd_profile *bfd_profile_lookup(const char *name);
+
+/**
+ * Removes profile from list and free memory.
+ *
+ * \param bp the BFD profile.
+ */
+void bfd_profile_free(struct bfd_profile *bp);
+
+/**
+ * Apply a profile configuration to an existing BFD session. The non default
+ * values will not be overridden.
+ *
+ * NOTE: if the profile doesn't exist yet, then the profile will be applied
+ * once it begins to exist.
+ *
+ * \param profile_name the BFD profile name.
+ * \param bs the BFD session.
+ */
+void bfd_profile_apply(const char *profname, struct bfd_session *bs);
+
+/**
+ * Remove any applied profile from session and revert the session
+ * configuration.
+ *
+ * \param bs the BFD session.
+ */
+void bfd_profile_remove(struct bfd_session *bs);
+
+/**
+ * Apply new profile values to sessions using it.
+ *
+ * \param[in] bp the BFD profile that got updated.
+ */
+void bfd_profile_update(struct bfd_profile *bp);
+
+/*
+ * bfdd_vty.c
+ *
+ * BFD daemon vty shell commands.
+ */
+void bfdd_vty_init(void);
+
+
+/*
+ * bfdd_cli.c
+ *
+ * BFD daemon CLI implementation.
+ */
+void bfdd_cli_init(void);
+
+
+/*
+ * ptm_adapter.c
+ */
+void bfdd_zclient_init(struct zebra_privs_t *bfdd_priv);
+void bfdd_zclient_stop(void);
+void bfdd_zclient_unregister(vrf_id_t vrf_id);
+void bfdd_zclient_register(vrf_id_t vrf_id);
+void bfdd_sessions_enable_vrf(struct vrf *vrf);
+void bfdd_sessions_disable_vrf(struct vrf *vrf);
+
+int ptm_bfd_notify(struct bfd_session *bs, uint8_t notify_state);
+
+/*
+ * dplane.c
+ */
+
+/**
+ * Initialize BFD data plane infrastructure for distributed BFD implementation.
+ *
+ * \param sa socket address.
+ * \param salen socket address structure length.
+ * \param client `true` means connecting socket, `false` listening socket.
+ */
+void bfd_dplane_init(const struct sockaddr *sa, socklen_t salen, bool client);
+
+/**
+ * Attempts to delegate the BFD session liveness detection to hardware.
+ *
+ * \param bs the BFD session data structure.
+ *
+ * \returns
+ * `0` on success and BFD daemon should do nothing or `-1` on failure
+ * and we should fallback to software implementation.
+ */
+int bfd_dplane_add_session(struct bfd_session *bs);
+
+/**
+ * Send new session settings to data plane.
+ *
+ * \param bs the BFD session to update.
+ */
+int bfd_dplane_update_session(const struct bfd_session *bs);
+
+/**
+ * Deletes session from data plane.
+ *
+ * \param bs the BFD session to delete.
+ *
+ * \returns `0` on success otherwise `-1`.
+ */
+int bfd_dplane_delete_session(struct bfd_session *bs);
+
+/**
+ * Asks the data plane for updated counters and update the session data
+ * structure.
+ *
+ * \param bs the BFD session that needs updating.
+ *
+ * \returns `0` on success otherwise `-1` on failure.
+ */
+int bfd_dplane_update_session_counters(struct bfd_session *bs);
+
+void bfd_dplane_show_counters(struct vty *vty);
+
+#endif /* _BFD_H_ */