bfdd: split northbound callbacks into multiple files

Rearrange the bfdd northbound callbacks as following:
* bfd_nb.h: prototypes of all northbound callbacks.
* bfd_nb.c: definition of all northbound callbacks and their
  associated YANG data paths.
* bfd_nb_config.c: implementation of YANG configuration nodes.
* bfd_nb_state.c: implementation of YANG state nodes.

This should help to keep to code more organized and easier to
maintain.

No behavior changes intended.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

1 files changed, 520 insertions, 0 deletions

diff --git a/bfdd/bfdd_nb_config.c b/bfdd/bfdd_nb_config.c
new file mode 100644
index 0000000000..50f953115c
--- /dev/null
+++ b/bfdd/bfdd_nb_config.c
@@ -0,0 +1,520 @@
+/*
+ * BFD daemon northbound implementation.
+ *
+ * Copyright (C) 2019 Network Device Education Foundation, Inc. ("NetDEF")
+ *                    Rafael Zalamena
+ *
+ * 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 Street, Fifth Floor, Boston, MA
+ * 02110-1301 USA.
+ */
+
+#include <zebra.h>
+
+#include "lib/log.h"
+#include "lib/northbound.h"
+
+#include "bfd.h"
+#include "bfdd_nb.h"
+
+/*
+ * Helpers.
+ */
+static void bfd_session_get_key(bool mhop, const struct lyd_node *dnode,
+				struct bfd_key *bk)
+{
+	const char *ifname = NULL, *vrfname = NULL;
+	struct sockaddr_any psa, lsa;
+
+	/* Required destination parameter. */
+	strtosa(yang_dnode_get_string(dnode, "./dest-addr"), &psa);
+
+	/* Get optional source address. */
+	memset(&lsa, 0, sizeof(lsa));
+	if (yang_dnode_exists(dnode, "./source-addr"))
+		strtosa(yang_dnode_get_string(dnode, "./source-addr"), &lsa);
+
+	/* Get optional interface and vrf names. */
+	if (yang_dnode_exists(dnode, "./interface"))
+		ifname = yang_dnode_get_string(dnode, "./interface");
+	if (yang_dnode_exists(dnode, "./vrf"))
+		vrfname = yang_dnode_get_string(dnode, "./vrf");
+
+	/* Generate the corresponding key. */
+	gen_bfd_key(bk, &psa, &lsa, mhop, ifname, vrfname);
+}
+
+static int bfd_session_create(enum nb_event event, const struct lyd_node *dnode,
+			      union nb_resource *resource, bool mhop)
+{
+	struct bfd_session *bs;
+	const char *ifname;
+	struct bfd_key bk;
+	struct prefix p;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		/*
+		 * When `dest-addr` is IPv6 and link-local we must
+		 * require interface name, otherwise we can't figure
+		 * which interface to use to send the packets.
+		 */
+		yang_dnode_get_prefix(&p, dnode, "./dest-addr");
+
+		/*
+		 * To support old FRR versions we must allow empty
+		 * interface to be specified, however that should
+		 * change in the future.
+		 */
+		if (yang_dnode_exists(dnode, "./interface"))
+			ifname = yang_dnode_get_string(dnode, "./interface");
+		else
+			ifname = "";
+
+		if (p.family == AF_INET6 && IN6_IS_ADDR_LINKLOCAL(&p.u.prefix6)
+		    && strlen(ifname) == 0) {
+			zlog_warn(
+				"%s: when using link-local you must specify "
+				"an interface.",
+				__func__);
+			return NB_ERR_VALIDATION;
+		}
+		break;
+
+	case NB_EV_PREPARE:
+		bfd_session_get_key(mhop, dnode, &bk);
+		bs = bfd_key_lookup(bk);
+
+		/* This session was already configured by another daemon. */
+		if (bs != NULL) {
+			/* Now it is configured also by CLI. */
+			BFD_SET_FLAG(bs->flags, BFD_SESS_FLAG_CONFIG);
+			bs->refcount++;
+
+			resource->ptr = bs;
+			break;
+		}
+
+		bs = bfd_session_new();
+		if (bs == NULL)
+			return NB_ERR_RESOURCE;
+
+		/* Fill the session key. */
+		bfd_session_get_key(mhop, dnode, &bs->key);
+
+		/* Set configuration flags. */
+		bs->refcount = 1;
+		BFD_SET_FLAG(bs->flags, BFD_SESS_FLAG_CONFIG);
+		if (mhop)
+			BFD_SET_FLAG(bs->flags, BFD_SESS_FLAG_MH);
+		if (bs->key.family == AF_INET6)
+			BFD_SET_FLAG(bs->flags, BFD_SESS_FLAG_IPV6);
+
+		resource->ptr = bs;
+		break;
+
+	case NB_EV_APPLY:
+		bs = resource->ptr;
+
+		/* Only attempt to registrate if freshly allocated. */
+		if (bs->discrs.my_discr == 0 && bs_registrate(bs) == NULL)
+			return NB_ERR_RESOURCE;
+
+		nb_running_set_entry(dnode, bs);
+		break;
+
+	case NB_EV_ABORT:
+		bs = resource->ptr;
+		if (bs->refcount <= 1)
+			bfd_session_free(resource->ptr);
+		break;
+	}
+
+	return NB_OK;
+}
+
+static int bfd_session_destroy(enum nb_event event,
+			       const struct lyd_node *dnode, bool mhop)
+{
+	struct bfd_session *bs;
+	struct bfd_key bk;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		bfd_session_get_key(mhop, dnode, &bk);
+		if (bfd_key_lookup(bk) == NULL)
+			return NB_ERR_INCONSISTENCY;
+		break;
+
+	case NB_EV_PREPARE:
+		/* NOTHING */
+		break;
+
+	case NB_EV_APPLY:
+		bs = nb_running_unset_entry(dnode);
+		/* CLI is not using this session anymore. */
+		if (BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_CONFIG) == 0)
+			break;
+
+		BFD_UNSET_FLAG(bs->flags, BFD_SESS_FLAG_CONFIG);
+		bs->refcount--;
+		/* There are still daemons using it. */
+		if (bs->refcount > 0)
+			break;
+
+		bfd_session_free(bs);
+		break;
+
+	case NB_EV_ABORT:
+		/* NOTHING */
+		break;
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-bfdd:bfdd/bfd
+ */
+int bfdd_bfd_create(enum nb_event event,
+		    const struct lyd_node *dnode __attribute__((__unused__)),
+		    union nb_resource *resource __attribute__((__unused__)))
+{
+	/* NOTHING */
+	return NB_OK;
+}
+
+int bfdd_bfd_destroy(enum nb_event event, const struct lyd_node *dnode)
+{
+	switch (event) {
+	case NB_EV_VALIDATE:
+		/* NOTHING */
+		return NB_OK;
+
+	case NB_EV_PREPARE:
+		/* NOTHING */
+		return NB_OK;
+
+	case NB_EV_APPLY:
+		bfd_sessions_remove_manual();
+		break;
+
+	case NB_EV_ABORT:
+		/* NOTHING */
+		return NB_OK;
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-bfdd:bfdd/bfd/sessions/single-hop
+ */
+int bfdd_bfd_sessions_single_hop_create(enum nb_event event,
+					const struct lyd_node *dnode,
+					union nb_resource *resource)
+{
+	return bfd_session_create(event, dnode, resource, false);
+}
+
+int bfdd_bfd_sessions_single_hop_destroy(enum nb_event event,
+					 const struct lyd_node *dnode)
+{
+	return bfd_session_destroy(event, dnode, false);
+}
+
+/*
+ * XPath: /frr-bfdd:bfdd/bfd/sessions/single-hop/source-addr
+ */
+int bfdd_bfd_sessions_single_hop_source_addr_modify(enum nb_event event
+						    __attribute__((__unused__)),
+						    const struct lyd_node *dnode
+						    __attribute__((__unused__)),
+						    union nb_resource *resource
+						    __attribute__((__unused__)))
+{
+	return NB_OK;
+}
+
+int bfdd_bfd_sessions_single_hop_source_addr_destroy(
+	enum nb_event event __attribute__((__unused__)),
+	const struct lyd_node *dnode __attribute__((__unused__)))
+{
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-bfdd:bfdd/bfd/sessions/single-hop/detection-multiplier
+ */
+int bfdd_bfd_sessions_single_hop_detection_multiplier_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource __attribute__((__unused__)))
+{
+	uint8_t detection_multiplier = yang_dnode_get_uint8(dnode, NULL);
+	struct bfd_session *bs;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		break;
+
+	case NB_EV_PREPARE:
+		/* NOTHING */
+		break;
+
+	case NB_EV_APPLY:
+		bs = nb_running_get_entry(dnode, NULL, true);
+		bs->detect_mult = detection_multiplier;
+		break;
+
+	case NB_EV_ABORT:
+		/* NOTHING */
+		break;
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-bfdd:bfdd/bfd/sessions/single-hop/desired-transmission-interval
+ */
+int bfdd_bfd_sessions_single_hop_desired_transmission_interval_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource __attribute__((__unused__)))
+{
+	uint32_t tx_interval = yang_dnode_get_uint32(dnode, NULL);
+	struct bfd_session *bs;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		if (tx_interval < 10000 || tx_interval > 60000000)
+			return NB_ERR_VALIDATION;
+		break;
+
+	case NB_EV_PREPARE:
+		/* NOTHING */
+		break;
+
+	case NB_EV_APPLY:
+		bs = nb_running_get_entry(dnode, NULL, true);
+		if (tx_interval == bs->timers.desired_min_tx)
+			return NB_OK;
+
+		bs->timers.desired_min_tx = tx_interval;
+		bfd_set_polling(bs);
+		break;
+
+	case NB_EV_ABORT:
+		/* NOTHING */
+		break;
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-bfdd:bfdd/bfd/sessions/single-hop/required-receive-interval
+ */
+int bfdd_bfd_sessions_single_hop_required_receive_interval_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource __attribute__((__unused__)))
+{
+	uint32_t rx_interval = yang_dnode_get_uint32(dnode, NULL);
+	struct bfd_session *bs;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		if (rx_interval < 10000 || rx_interval > 60000000)
+			return NB_ERR_VALIDATION;
+		break;
+
+	case NB_EV_PREPARE:
+		/* NOTHING */
+		break;
+
+	case NB_EV_APPLY:
+		bs = nb_running_get_entry(dnode, NULL, true);
+		if (rx_interval == bs->timers.required_min_rx)
+			return NB_OK;
+
+		bs->timers.required_min_rx = rx_interval;
+		bfd_set_polling(bs);
+		break;
+
+	case NB_EV_ABORT:
+		/* NOTHING */
+		break;
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-bfdd:bfdd/bfd/sessions/single-hop/administrative-down
+ */
+int bfdd_bfd_sessions_single_hop_administrative_down_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource __attribute__((__unused__)))
+{
+	bool shutdown = yang_dnode_get_bool(dnode, NULL);
+	struct bfd_session *bs;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+	case NB_EV_PREPARE:
+		return NB_OK;
+
+	case NB_EV_APPLY:
+		break;
+
+	case NB_EV_ABORT:
+		return NB_OK;
+	}
+
+	bs = nb_running_get_entry(dnode, NULL, true);
+
+	if (shutdown == false) {
+		if (!BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_SHUTDOWN))
+			return NB_OK;
+
+		BFD_UNSET_FLAG(bs->flags, BFD_SESS_FLAG_SHUTDOWN);
+
+		/* Change and notify state change. */
+		bs->ses_state = PTM_BFD_DOWN;
+		control_notify(bs, bs->ses_state);
+
+		/* Enable all timers. */
+		bfd_recvtimer_update(bs);
+		bfd_xmttimer_update(bs, bs->xmt_TO);
+		if (BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_ECHO)) {
+			bfd_echo_recvtimer_update(bs);
+			bfd_echo_xmttimer_update(bs, bs->echo_xmt_TO);
+		}
+	} else {
+		if (BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_SHUTDOWN))
+			return NB_OK;
+
+		BFD_SET_FLAG(bs->flags, BFD_SESS_FLAG_SHUTDOWN);
+
+		/* Disable all events. */
+		bfd_recvtimer_delete(bs);
+		bfd_echo_recvtimer_delete(bs);
+		bfd_xmttimer_delete(bs);
+		bfd_echo_xmttimer_delete(bs);
+
+		/* Change and notify state change. */
+		bs->ses_state = PTM_BFD_ADM_DOWN;
+		control_notify(bs, bs->ses_state);
+
+		ptm_bfd_snd(bs, 0);
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-bfdd:bfdd/bfd/sessions/single-hop/echo-mode
+ */
+int bfdd_bfd_sessions_single_hop_echo_mode_modify(enum nb_event event,
+						  const struct lyd_node *dnode,
+						  union nb_resource *resource
+						  __attribute__((__unused__)))
+{
+	bool echo = yang_dnode_get_bool(dnode, NULL);
+	struct bfd_session *bs;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+	case NB_EV_PREPARE:
+		return NB_OK;
+
+	case NB_EV_APPLY:
+		break;
+
+	case NB_EV_ABORT:
+		return NB_OK;
+	}
+
+	bs = nb_running_get_entry(dnode, NULL, true);
+
+	if (echo == false) {
+		if (!BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_ECHO))
+			return NB_OK;
+
+		BFD_UNSET_FLAG(bs->flags, BFD_SESS_FLAG_ECHO);
+		ptm_bfd_echo_stop(bs);
+	} else {
+		if (BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_ECHO))
+			return NB_OK;
+
+		BFD_SET_FLAG(bs->flags, BFD_SESS_FLAG_ECHO);
+		/* Apply setting immediately. */
+		if (!BFD_CHECK_FLAG(bs->flags, BFD_SESS_FLAG_SHUTDOWN))
+			bs_echo_timer_handler(bs);
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath:
+ * /frr-bfdd:bfdd/bfd/sessions/single-hop/desired-echo-transmission-interval
+ */
+int bfdd_bfd_sessions_single_hop_desired_echo_transmission_interval_modify(
+	enum nb_event event, const struct lyd_node *dnode,
+	union nb_resource *resource __attribute__((__unused__)))
+{
+	uint32_t echo_interval = yang_dnode_get_uint32(dnode, NULL);
+	struct bfd_session *bs;
+
+	switch (event) {
+	case NB_EV_VALIDATE:
+		if (echo_interval < 10000 || echo_interval > 60000000)
+			return NB_ERR_VALIDATION;
+		break;
+
+	case NB_EV_PREPARE:
+		/* NOTHING */
+		break;
+
+	case NB_EV_APPLY:
+		bs = nb_running_get_entry(dnode, NULL, true);
+		if (echo_interval == bs->timers.required_min_echo)
+			return NB_OK;
+
+		bs->timers.required_min_echo = echo_interval;
+		break;
+
+	case NB_EV_ABORT:
+		/* NOTHING */
+		break;
+	}
+
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-bfdd:bfdd/bfd/sessions/multi-hop
+ */
+int bfdd_bfd_sessions_multi_hop_create(enum nb_event event,
+				       const struct lyd_node *dnode,
+				       union nb_resource *resource)
+{
+	return bfd_session_create(event, dnode, resource, true);
+}
+
+int bfdd_bfd_sessions_multi_hop_destroy(enum nb_event event,
+					const struct lyd_node *dnode)
+{
+	return bfd_session_destroy(event, dnode, true);
+}