doc: sample code-doc in .rst+sphinx

[mirror_frr.git] / eigrpd / eigrp_interface.c

/*
 * EIGRP Interface Functions.
 * Copyright (C) 2013-2016
 * Authors:
 *   Donnie Savage
 *   Jan Janovic
 *   Matej Perina
 *   Peter Orsag
 *   Peter Paluch
 *   Frantisek Gazo
 *   Tomas Hvorkovy
 *   Martin Kontsek
 *   Lukas Koribsky
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra 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, or (at your option) any
 * later version.
 *
 * GNU Zebra 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
 */

#include <zebra.h>

#include "thread.h"
#include "linklist.h"
#include "prefix.h"
#include "if.h"
#include "table.h"
#include "memory.h"
#include "command.h"
#include "stream.h"
#include "log.h"
#include "keychain.h"
#include "vrf.h"

#include "eigrpd/eigrp_structs.h"
#include "eigrpd/eigrpd.h"
#include "eigrpd/eigrp_interface.h"
#include "eigrpd/eigrp_neighbor.h"
#include "eigrpd/eigrp_packet.h"
#include "eigrpd/eigrp_zebra.h"
#include "eigrpd/eigrp_vty.h"
#include "eigrpd/eigrp_network.h"
#include "eigrpd/eigrp_topology.h"
#include "eigrpd/eigrp_memory.h"

static void eigrp_delete_from_if(struct interface *, struct eigrp_interface *);

static void eigrp_add_to_if(struct interface *ifp, struct eigrp_interface *ei)
{
	struct route_node *rn;
	struct prefix p;

	p = *ei->address;
	p.prefixlen = IPV4_MAX_PREFIXLEN;

	rn = route_node_get(IF_OIFS(ifp), &p);
	/* rn->info should either be NULL or equal to this ei
	 * as route_node_get may return an existing node
	 */
	assert(!rn->info || rn->info == ei);
	rn->info = ei;
}

struct eigrp_interface *eigrp_if_new(struct eigrp *eigrp, struct interface *ifp,
				     struct prefix *p)
{
	struct eigrp_interface *ei;
	int i;

	if ((ei = eigrp_if_table_lookup(ifp, p)) == NULL) {
		ei = XCALLOC(MTYPE_EIGRP_IF, sizeof(struct eigrp_interface));
		memset(ei, 0, sizeof(struct eigrp_interface));
	} else
		return ei;

	/* Set zebra interface pointer. */
	ei->ifp = ifp;
	ei->address = p;

	eigrp_add_to_if(ifp, ei);
	listnode_add(eigrp->eiflist, ei);

	ei->type = EIGRP_IFTYPE_BROADCAST;

	/* Initialize neighbor list. */
	ei->nbrs = list_new();

	ei->crypt_seqnum = time(NULL);

	/* Initialize lists */
	for (i = 0; i < EIGRP_FILTER_MAX; i++) {
		ei->list[i] = NULL;
		ei->prefix[i] = NULL;
		ei->routemap[i] = NULL;
	}

	return ei;
}

/* lookup ei for specified prefix/ifp */
struct eigrp_interface *eigrp_if_table_lookup(struct interface *ifp,
					      struct prefix *prefix)
{
	struct prefix p;
	struct route_node *rn;
	struct eigrp_interface *rninfo = NULL;

	p = *prefix;
	p.prefixlen = IPV4_MAX_PREFIXLEN;

	/* route_node_get implicitly locks */
	if ((rn = route_node_lookup(IF_OIFS(ifp), &p))) {
		rninfo = (struct eigrp_interface *)rn->info;
		route_unlock_node(rn);
	}

	return rninfo;
}

int eigrp_if_delete_hook(struct interface *ifp)
{
	struct route_node *rn;

	route_table_finish(IF_OIFS(ifp));

	for (rn = route_top(IF_OIFS_PARAMS(ifp)); rn; rn = route_next(rn))
		if (rn->info)
			eigrp_del_if_params(rn->info);
	route_table_finish(IF_OIFS_PARAMS(ifp));

	XFREE(MTYPE_EIGRP_IF_INFO, ifp->info);
	ifp->info = NULL;

	return 0;
}

struct list *eigrp_iflist;

void eigrp_if_init()
{
	/* Initialize Zebra interface data structure. */
	if_add_hook(IF_NEW_HOOK, eigrp_if_new_hook);
	if_add_hook(IF_DELETE_HOOK, eigrp_if_delete_hook);
}

int eigrp_if_new_hook(struct interface *ifp)
{
	int rc = 0;

	ifp->info = XCALLOC(MTYPE_EIGRP_IF_INFO, sizeof(struct eigrp_if_info));

	IF_OIFS(ifp) = route_table_init();
	IF_OIFS_PARAMS(ifp) = route_table_init();

	IF_DEF_PARAMS(ifp) = eigrp_new_if_params();

	SET_IF_PARAM(IF_DEF_PARAMS(ifp), v_hello);
	IF_DEF_PARAMS(ifp)->v_hello = (u_int32_t)EIGRP_HELLO_INTERVAL_DEFAULT;

	SET_IF_PARAM(IF_DEF_PARAMS(ifp), v_wait);
	IF_DEF_PARAMS(ifp)->v_wait = (u_int16_t)EIGRP_HOLD_INTERVAL_DEFAULT;

	SET_IF_PARAM(IF_DEF_PARAMS(ifp), bandwidth);
	IF_DEF_PARAMS(ifp)->bandwidth = (u_int32_t)EIGRP_BANDWIDTH_DEFAULT;

	SET_IF_PARAM(IF_DEF_PARAMS(ifp), delay);
	IF_DEF_PARAMS(ifp)->delay = (u_int32_t)EIGRP_DELAY_DEFAULT;

	SET_IF_PARAM(IF_DEF_PARAMS(ifp), reliability);
	IF_DEF_PARAMS(ifp)->reliability = (u_char)EIGRP_RELIABILITY_DEFAULT;

	SET_IF_PARAM(IF_DEF_PARAMS(ifp), load);
	IF_DEF_PARAMS(ifp)->load = (u_char)EIGRP_LOAD_DEFAULT;

	SET_IF_PARAM(IF_DEF_PARAMS(ifp), auth_type);
	IF_DEF_PARAMS(ifp)->auth_type = EIGRP_AUTH_TYPE_NONE;

	SET_IF_PARAM(IF_DEF_PARAMS(ifp), auth_keychain);
	IF_DEF_PARAMS(ifp)->auth_keychain = NULL;

	return rc;
}

struct eigrp_if_params *eigrp_new_if_params(void)
{
	struct eigrp_if_params *eip;

	eip = XCALLOC(MTYPE_EIGRP_IF_PARAMS, sizeof(struct eigrp_if_params));
	if (!eip)
		return NULL;

	UNSET_IF_PARAM(eip, passive_interface);
	UNSET_IF_PARAM(eip, v_hello);
	UNSET_IF_PARAM(eip, v_wait);
	UNSET_IF_PARAM(eip, bandwidth);
	UNSET_IF_PARAM(eip, delay);
	UNSET_IF_PARAM(eip, reliability);
	UNSET_IF_PARAM(eip, load);
	UNSET_IF_PARAM(eip, auth_keychain);
	UNSET_IF_PARAM(eip, auth_type);

	return eip;
}

void eigrp_del_if_params(struct eigrp_if_params *eip)
{
	if (eip->auth_keychain)
		free(eip->auth_keychain);

	XFREE(MTYPE_EIGRP_IF_PARAMS, eip);
}

struct eigrp_if_params *eigrp_lookup_if_params(struct interface *ifp,
					       struct in_addr addr)
{
	struct prefix_ipv4 p;
	struct route_node *rn;

	p.family = AF_INET;
	p.prefixlen = IPV4_MAX_PREFIXLEN;
	p.prefix = addr;

	rn = route_node_lookup(IF_OIFS_PARAMS(ifp), (struct prefix *)&p);

	if (rn) {
		route_unlock_node(rn);
		return rn->info;
	}

	return NULL;
}

int eigrp_if_up(struct eigrp_interface *ei)
{
	struct eigrp_prefix_entry *pe;
	struct eigrp_neighbor_entry *ne;
	struct eigrp_metrics metric;
	struct eigrp_interface *ei2;
	struct listnode *node, *nnode;
	struct eigrp *eigrp = eigrp_lookup();

	if (ei == NULL)
		return 0;

	if (eigrp != NULL)
		eigrp_adjust_sndbuflen(eigrp, ei->ifp->mtu);
	else
		zlog_warn("%s: eigrp_lookup () returned NULL", __func__);
	eigrp_if_stream_set(ei);

	/* Set multicast memberships appropriately for new state. */
	eigrp_if_set_multicast(ei);

	thread_add_event(master, eigrp_hello_timer, ei, (1), NULL);

	/*Prepare metrics*/
	metric.bandwidth =
		eigrp_bandwidth_to_scaled(EIGRP_IF_PARAM(ei, bandwidth));
	metric.delay = eigrp_delay_to_scaled(EIGRP_IF_PARAM(ei, delay));
	metric.load = EIGRP_IF_PARAM(ei, load);
	metric.reliability = EIGRP_IF_PARAM(ei, reliability);
	metric.mtu[0] = 0xDC;
	metric.mtu[1] = 0x05;
	metric.mtu[2] = 0x00;
	metric.hop_count = 0;
	metric.flags = 0;
	metric.tag = 0;

	/*Add connected entry to topology table*/

	struct prefix_ipv4 dest_addr;

	dest_addr.family = AF_INET;
	dest_addr.prefix = ei->connected->address->u.prefix4;
	dest_addr.prefixlen = ei->connected->address->prefixlen;
	apply_mask_ipv4(&dest_addr);
	pe = eigrp_topology_table_lookup_ipv4(eigrp->topology_table,
					      &dest_addr);

	if (pe == NULL) {
		pe = eigrp_prefix_entry_new();
		pe->serno = eigrp->serno;
		pe->destination_ipv4 = prefix_ipv4_new();
		prefix_copy((struct prefix *)pe->destination_ipv4,
			    (struct prefix *)&dest_addr);
		pe->af = AF_INET;
		pe->nt = EIGRP_TOPOLOGY_TYPE_CONNECTED;

		pe->state = EIGRP_FSM_STATE_PASSIVE;
		pe->fdistance = eigrp_calculate_metrics(eigrp, metric);
		pe->req_action |= EIGRP_FSM_NEED_UPDATE;
		eigrp_prefix_entry_add(eigrp->topology_table, pe);
		listnode_add(eigrp->topology_changes_internalIPV4, pe);
	}
	ne = eigrp_neighbor_entry_new();
	ne->ei = ei;
	ne->reported_metric = metric;
	ne->total_metric = metric;
	ne->distance = eigrp_calculate_metrics(eigrp, metric);
	ne->reported_distance = 0;
	ne->prefix = pe;
	ne->adv_router = eigrp->neighbor_self;
	ne->flags = EIGRP_NEIGHBOR_ENTRY_SUCCESSOR_FLAG;
	eigrp_neighbor_entry_add(pe, ne);

	for (ALL_LIST_ELEMENTS(eigrp->eiflist, node, nnode, ei2)) {
		if (ei2->nbrs->count != 0) {
			eigrp_update_send(ei2);
		}
	}

	pe->req_action &= ~EIGRP_FSM_NEED_UPDATE;
	listnode_delete(eigrp->topology_changes_internalIPV4, pe);

	return 1;
}

int eigrp_if_down(struct eigrp_interface *ei)
{
	struct listnode *node, *nnode;
	struct eigrp_neighbor *nbr;

	if (ei == NULL)
		return 0;

	/* Shutdown packet reception and sending */
	if (ei->t_hello)
		THREAD_OFF(ei->t_hello);

	eigrp_if_stream_unset(ei);

	/*Set infinite metrics to routes learned by this interface and start
	 * query process*/
	for (ALL_LIST_ELEMENTS(ei->nbrs, node, nnode, nbr)) {
		eigrp_nbr_delete(nbr);
	}

	return 1;
}

void eigrp_if_stream_set(struct eigrp_interface *ei)
{
	/* set output fifo queue. */
	if (ei->obuf == NULL)
		ei->obuf = eigrp_fifo_new();
}

void eigrp_if_stream_unset(struct eigrp_interface *ei)
{
	struct eigrp *eigrp = ei->eigrp;

	if (ei->obuf) {
		eigrp_fifo_free(ei->obuf);
		ei->obuf = NULL;

		if (ei->on_write_q) {
			listnode_delete(eigrp->oi_write_q, ei);
			if (list_isempty(eigrp->oi_write_q))
				thread_cancel(eigrp->t_write);
			ei->on_write_q = 0;
		}
	}
}

void eigrp_if_set_multicast(struct eigrp_interface *ei)
{
	if ((EIGRP_IF_PASSIVE_STATUS(ei) == EIGRP_IF_ACTIVE)) {
		/* The interface should belong to the EIGRP-all-routers group.
		 */
		if (!EI_MEMBER_CHECK(ei, MEMBER_ALLROUTERS)
		    && (eigrp_if_add_allspfrouters(ei->eigrp, ei->address,
						   ei->ifp->ifindex)
			>= 0))
			/* Set the flag only if the system call to join
			 * succeeded. */
			EI_MEMBER_JOINED(ei, MEMBER_ALLROUTERS);
	} else {
		/* The interface should NOT belong to the EIGRP-all-routers
		 * group. */
		if (EI_MEMBER_CHECK(ei, MEMBER_ALLROUTERS)) {
			/* Only actually drop if this is the last reference */
			if (EI_MEMBER_COUNT(ei, MEMBER_ALLROUTERS) == 1)
				eigrp_if_drop_allspfrouters(ei->eigrp,
							    ei->address,
							    ei->ifp->ifindex);
			/* Unset the flag regardless of whether the system call
			   to leave
			   the group succeeded, since it's much safer to assume
			   that
			   we are not a member. */
			EI_MEMBER_LEFT(ei, MEMBER_ALLROUTERS);
		}
	}
}

u_char eigrp_default_iftype(struct interface *ifp)
{
	if (if_is_pointopoint(ifp))
		return EIGRP_IFTYPE_POINTOPOINT;
	else if (if_is_loopback(ifp))
		return EIGRP_IFTYPE_LOOPBACK;
	else
		return EIGRP_IFTYPE_BROADCAST;
}

void eigrp_if_free(struct eigrp_interface *ei, int source)
{
	struct prefix_ipv4 dest_addr;
	struct eigrp_prefix_entry *pe;
	struct eigrp *eigrp = eigrp_lookup();

	if (source == INTERFACE_DOWN_BY_VTY) {
		THREAD_OFF(ei->t_hello);
		eigrp_hello_send(ei, EIGRP_HELLO_GRACEFUL_SHUTDOWN, NULL);
	}

	dest_addr.family = AF_INET;
	dest_addr.prefix = ei->connected->address->u.prefix4;
	dest_addr.prefixlen = ei->connected->address->prefixlen;
	apply_mask_ipv4(&dest_addr);
	pe = eigrp_topology_table_lookup_ipv4(eigrp->topology_table,
					      &dest_addr);
	if (pe)
		eigrp_prefix_entry_delete(eigrp->topology_table, pe);

	eigrp_if_down(ei);

	list_delete(ei->nbrs);
	eigrp_delete_from_if(ei->ifp, ei);
	listnode_delete(ei->eigrp->eiflist, ei);

	thread_cancel_event(master, ei);

	memset(ei, 0, sizeof(*ei));
	XFREE(MTYPE_EIGRP_IF, ei);
}

static void eigrp_delete_from_if(struct interface *ifp,
				 struct eigrp_interface *ei)
{
	struct route_node *rn;
	struct prefix p;

	p = *ei->address;
	p.prefixlen = IPV4_MAX_PREFIXLEN;

	rn = route_node_lookup(IF_OIFS(ei->ifp), &p);
	assert(rn);
	assert(rn->info);
	rn->info = NULL;
	route_unlock_node(rn);
	route_unlock_node(rn);
}

/* Simulate down/up on the interface.  This is needed, for example, when
   the MTU changes. */
void eigrp_if_reset(struct interface *ifp)
{
	struct route_node *rn;

	for (rn = route_top(IF_OIFS(ifp)); rn; rn = route_next(rn)) {
		struct eigrp_interface *ei;

		if ((ei = rn->info) == NULL)
			continue;

		eigrp_if_down(ei);
		eigrp_if_up(ei);
	}
}

struct eigrp_interface *eigrp_if_lookup_by_local_addr(struct eigrp *eigrp,
						      struct interface *ifp,
						      struct in_addr address)
{
	struct listnode *node;
	struct eigrp_interface *ei;

	for (ALL_LIST_ELEMENTS_RO(eigrp->eiflist, node, ei)) {
		if (ifp && ei->ifp != ifp)
			continue;

		if (IPV4_ADDR_SAME(&address, &ei->address->u.prefix4))
			return ei;
	}

	return NULL;
}

/**
 * @fn eigrp_if_lookup_by_name
 *
 * @param[in]		eigrp		EIGRP process
 * @param[in]		if_name 	Name of the interface
 *
 * @return struct eigrp_interface *
 *
 * @par
 * Function is used for lookup interface by name.
 */
struct eigrp_interface *eigrp_if_lookup_by_name(struct eigrp *eigrp,
						const char *if_name)
{
	struct eigrp_interface *ei;
	struct listnode *node;

	/* iterate over all eigrp interfaces */
	for (ALL_LIST_ELEMENTS_RO(eigrp->eiflist, node, ei)) {
		/* compare int name with eigrp interface's name */
		if (strcmp(ei->ifp->name, if_name) == 0) {
			return ei;
		}
	}

	return NULL;
}

/* determine receiving interface by ifp and source address */
struct eigrp_interface *eigrp_if_lookup_recv_if(struct eigrp *eigrp,
						struct in_addr src,
						struct interface *ifp)
{
	struct route_node *rn;
	struct prefix_ipv4 addr;
	struct eigrp_interface *ei, *match;

	addr.family = AF_INET;
	addr.prefix = src;
	addr.prefixlen = IPV4_MAX_BITLEN;

	match = NULL;

	for (rn = route_top(IF_OIFS(ifp)); rn; rn = route_next(rn)) {
		ei = rn->info;

		if (!ei) /* oi can be NULL for PtP aliases */
			continue;

		if (if_is_loopback(ei->ifp))
			continue;

		if (prefix_match(CONNECTED_PREFIX(ei->connected),
				 (struct prefix *)&addr)) {
			if ((match == NULL) || (match->address->prefixlen
						< ei->address->prefixlen))
				match = ei;
		}
	}

	return match;
}

u_int32_t eigrp_bandwidth_to_scaled(u_int32_t bandwidth)
{
	uint64_t temp_bandwidth = (256ull * 10000000) / bandwidth;

	temp_bandwidth = temp_bandwidth < EIGRP_MAX_METRIC ? temp_bandwidth
							   : EIGRP_MAX_METRIC;

	return (u_int32_t)temp_bandwidth;
}

u_int32_t eigrp_scaled_to_bandwidth(u_int32_t scaled)
{
	uint64_t temp_scaled = scaled * (256ull * 10000000);

	temp_scaled =
		temp_scaled < EIGRP_MAX_METRIC ? temp_scaled : EIGRP_MAX_METRIC;

	return (u_int32_t)temp_scaled;
}

u_int32_t eigrp_delay_to_scaled(u_int32_t delay)
{
	return delay * 256;
}

u_int32_t eigrp_scaled_to_delay(u_int32_t scaled)
{
	return scaled / 256;
}