Merge pull request #9649 from proelbtn/add-support-for-end-dt4

[mirror_frr.git] / ripd / rip_interface.c

/* Interface related function for RIP.
 * Copyright (C) 1997, 98 Kunihiro Ishiguro <kunihiro@zebra.org>
 *
 * 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 "command.h"
#include "if.h"
#include "sockunion.h"
#include "prefix.h"
#include "memory.h"
#include "network.h"
#include "table.h"
#include "log.h"
#include "stream.h"
#include "thread.h"
#include "zclient.h"
#include "filter.h"
#include "sockopt.h"
#include "privs.h"
#include "lib_errors.h"
#include "northbound_cli.h"

#include "zebra/connected.h"

#include "ripd/ripd.h"
#include "ripd/rip_debug.h"
#include "ripd/rip_interface.h"

DEFINE_MTYPE_STATIC(RIPD, RIP_INTERFACE, "RIP interface");
DEFINE_MTYPE(RIPD, RIP_INTERFACE_STRING, "RIP Interface String");
DEFINE_HOOK(rip_ifaddr_add, (struct connected * ifc), (ifc));
DEFINE_HOOK(rip_ifaddr_del, (struct connected * ifc), (ifc));

/* static prototypes */
static void rip_enable_apply(struct interface *);
static void rip_passive_interface_apply(struct interface *);
static int rip_if_down(struct interface *ifp);
static int rip_enable_if_lookup(struct rip *rip, const char *ifname);
static int rip_enable_network_lookup2(struct connected *connected);
static void rip_enable_apply_all(struct rip *rip);

const struct message ri_version_msg[] = {{RI_RIP_VERSION_1, "1"},
                                         {RI_RIP_VERSION_2, "2"},
                                         {RI_RIP_VERSION_1_AND_2, "1 2"},
                                         {RI_RIP_VERSION_NONE, "none"},
                                         {0}};

/* Join to the RIP version 2 multicast group. */
static int ipv4_multicast_join(int sock, struct in_addr group,
                               struct in_addr ifa, ifindex_t ifindex)
{
        int ret;

        ret = setsockopt_ipv4_multicast(sock, IP_ADD_MEMBERSHIP, ifa,
                                        group.s_addr, ifindex);

        if (ret < 0)
                zlog_info("can't setsockopt IP_ADD_MEMBERSHIP %s",
                          safe_strerror(errno));

        return ret;
}

/* Leave from the RIP version 2 multicast group. */
static int ipv4_multicast_leave(int sock, struct in_addr group,
                                struct in_addr ifa, ifindex_t ifindex)
{
        int ret;

        ret = setsockopt_ipv4_multicast(sock, IP_DROP_MEMBERSHIP, ifa,
                                        group.s_addr, ifindex);

        if (ret < 0)
                zlog_info("can't setsockopt IP_DROP_MEMBERSHIP");

        return ret;
}

static void rip_interface_reset(struct rip_interface *);

/* Allocate new RIP's interface configuration. */
static struct rip_interface *rip_interface_new(void)
{
        struct rip_interface *ri;

        ri = XCALLOC(MTYPE_RIP_INTERFACE, sizeof(struct rip_interface));

        rip_interface_reset(ri);

        return ri;
}

void rip_interface_multicast_set(int sock, struct connected *connected)
{
        struct in_addr addr;

        assert(connected != NULL);

        addr = CONNECTED_ID(connected)->u.prefix4;

        if (setsockopt_ipv4_multicast_if(sock, addr, connected->ifp->ifindex)
            < 0) {
                zlog_warn(
                        "Can't setsockopt IP_MULTICAST_IF on fd %d to ifindex %d for interface %s",
                        sock, connected->ifp->ifindex, connected->ifp->name);
        }

        return;
}

/* Send RIP request packet to specified interface. */
static void rip_request_interface_send(struct interface *ifp, uint8_t version)
{
        struct sockaddr_in to;

        /* RIPv2 support multicast. */
        if (version == RIPv2 && if_is_multicast(ifp)) {

                if (IS_RIP_DEBUG_EVENT)
                        zlog_debug("multicast request on %s", ifp->name);

                rip_request_send(NULL, ifp, version, NULL);
                return;
        }

        /* RIPv1 and non multicast interface. */
        if (if_is_pointopoint(ifp) || if_is_broadcast(ifp)) {
                struct listnode *cnode, *cnnode;
                struct connected *connected;

                if (IS_RIP_DEBUG_EVENT)
                        zlog_debug("broadcast request to %s", ifp->name);

                for (ALL_LIST_ELEMENTS(ifp->connected, cnode, cnnode,
                                       connected)) {
                        if (connected->address->family != AF_INET)
                                continue;

                        memset(&to, 0, sizeof(struct sockaddr_in));
                        to.sin_port = htons(RIP_PORT_DEFAULT);
                        if (connected->destination)
                                /* use specified broadcast or peer
                                 * destination addr */
                                to.sin_addr = connected->destination->u.prefix4;
                        else if (connected->address->prefixlen
                                 < IPV4_MAX_BITLEN)
                                /* calculate the appropriate broadcast
                                 * address */
                                to.sin_addr.s_addr = ipv4_broadcast_addr(
                                        connected->address->u.prefix4.s_addr,
                                        connected->address->prefixlen);
                        else
                                /* do not know where to send the packet
                                 */
                                continue;

                        if (IS_RIP_DEBUG_EVENT)
                                zlog_debug("SEND request to %pI4",
                                           &to.sin_addr);

                        rip_request_send(&to, ifp, version, connected);
                }
        }
}

/* This will be executed when interface goes up. */
static void rip_request_interface(struct interface *ifp)
{
        struct rip_interface *ri;
        int vsend;

        /* In default ripd doesn't send RIP_REQUEST to the loopback interface.
         */
        if (if_is_loopback(ifp))
                return;

        /* If interface is down, don't send RIP packet. */
        if (!if_is_operative(ifp))
                return;

        /* Fetch RIP interface information. */
        ri = ifp->info;

        /* If there is no version configuration in the interface,
           use rip's version setting. */
        vsend = ((ri->ri_send == RI_RIP_UNSPEC) ? ri->rip->version_send
                                                : ri->ri_send);
        if (vsend & RIPv1)
                rip_request_interface_send(ifp, RIPv1);
        if (vsend & RIPv2)
                rip_request_interface_send(ifp, RIPv2);
}

/* Multicast packet receive socket. */
static int rip_multicast_join(struct interface *ifp, int sock)
{
        struct listnode *cnode;
        struct connected *ifc;

        if (if_is_operative(ifp) && if_is_multicast(ifp)) {
                if (IS_RIP_DEBUG_EVENT)
                        zlog_debug("multicast join at %s", ifp->name);

                for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, ifc)) {
                        struct prefix_ipv4 *p;
                        struct in_addr group;

                        p = (struct prefix_ipv4 *)ifc->address;

                        if (p->family != AF_INET)
                                continue;

                        group.s_addr = htonl(INADDR_RIP_GROUP);
                        if (ipv4_multicast_join(sock, group, p->prefix,
                                                ifp->ifindex)
                            < 0)
                                return -1;
                        else
                                return 0;
                }
        }
        return 0;
}

/* Leave from multicast group. */
static void rip_multicast_leave(struct interface *ifp, int sock)
{
        struct listnode *cnode;
        struct connected *connected;

        if (if_is_up(ifp) && if_is_multicast(ifp)) {
                if (IS_RIP_DEBUG_EVENT)
                        zlog_debug("multicast leave from %s", ifp->name);

                for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, connected)) {
                        struct prefix_ipv4 *p;
                        struct in_addr group;

                        p = (struct prefix_ipv4 *)connected->address;

                        if (p->family != AF_INET)
                                continue;

                        group.s_addr = htonl(INADDR_RIP_GROUP);
                        if (ipv4_multicast_leave(sock, group, p->prefix,
                                                 ifp->ifindex)
                            == 0)
                                return;
                }
        }
}

/* Is there and address on interface that I could use ? */
static int rip_if_ipv4_address_check(struct interface *ifp)
{
        struct listnode *nn;
        struct connected *connected;
        int count = 0;

        for (ALL_LIST_ELEMENTS_RO(ifp->connected, nn, connected)) {
                struct prefix *p;

                p = connected->address;

                if (p->family == AF_INET)
                        count++;
        }

        return count;
}


/* Does this address belongs to me ? */
int if_check_address(struct rip *rip, struct in_addr addr)
{
        struct interface *ifp;

        FOR_ALL_INTERFACES (rip->vrf, ifp) {
                struct listnode *cnode;
                struct connected *connected;

                for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, connected)) {
                        struct prefix_ipv4 *p;

                        p = (struct prefix_ipv4 *)connected->address;

                        if (p->family != AF_INET)
                                continue;

                        if (IPV4_ADDR_CMP(&p->prefix, &addr) == 0)
                                return 1;
                }
        }
        return 0;
}

/* Inteface link down message processing. */
static int rip_ifp_down(struct interface *ifp)
{
        rip_interface_sync(ifp);
        rip_if_down(ifp);

        if (IS_RIP_DEBUG_ZEBRA)
                zlog_debug(
                        "interface %s vrf %s(%u) index %d flags %llx metric %d mtu %d is down",
                        ifp->name, ifp->vrf->name, ifp->vrf->vrf_id,
                        ifp->ifindex, (unsigned long long)ifp->flags,
                        ifp->metric, ifp->mtu);

        return 0;
}

/* Inteface link up message processing */
static int rip_ifp_up(struct interface *ifp)
{
        if (IS_RIP_DEBUG_ZEBRA)
                zlog_debug(
                        "interface %s vrf %s(%u) index %d flags %#llx metric %d mtu %d is up",
                        ifp->name, ifp->vrf->name, ifp->vrf->vrf_id,
                        ifp->ifindex, (unsigned long long)ifp->flags,
                        ifp->metric, ifp->mtu);

        rip_interface_sync(ifp);

        /* Check if this interface is RIP enabled or not.*/
        rip_enable_apply(ifp);

        /* Check for a passive interface */
        rip_passive_interface_apply(ifp);

        /* Apply distribute list to the all interface. */
        rip_distribute_update_interface(ifp);

        return 0;
}

/* Inteface addition message from zebra. */
static int rip_ifp_create(struct interface *ifp)
{
        rip_interface_sync(ifp);

        if (IS_RIP_DEBUG_ZEBRA)
                zlog_debug(
                        "interface add %s vrf %s(%u) index %d flags %#llx metric %d mtu %d",
                        ifp->name, ifp->vrf->name, ifp->vrf->vrf_id,
                        ifp->ifindex, (unsigned long long)ifp->flags,
                        ifp->metric, ifp->mtu);

        /* Check if this interface is RIP enabled or not.*/
        rip_enable_apply(ifp);

        /* Check for a passive interface */
        rip_passive_interface_apply(ifp);

        /* Apply distribute list to the all interface. */
        rip_distribute_update_interface(ifp);

        /* rip_request_neighbor_all (); */

        /* Check interface routemap. */
        rip_if_rmap_update_interface(ifp);

        return 0;
}

static int rip_ifp_destroy(struct interface *ifp)
{
        rip_interface_sync(ifp);
        if (if_is_up(ifp)) {
                rip_if_down(ifp);
        }

        if (IS_RIP_DEBUG_ZEBRA)
                zlog_debug(
                        "interface delete %s vrf %s(%u) index %d flags %#llx metric %d mtu %d",
                        ifp->name, ifp->vrf->name, ifp->vrf->vrf_id,
                        ifp->ifindex, (unsigned long long)ifp->flags,
                        ifp->metric, ifp->mtu);

        return 0;
}

/* VRF update for an interface. */
int rip_interface_vrf_update(ZAPI_CALLBACK_ARGS)
{
        struct interface *ifp;
        vrf_id_t new_vrf_id;

        ifp = zebra_interface_vrf_update_read(zclient->ibuf, vrf_id,
                                              &new_vrf_id);
        if (!ifp)
                return 0;

        if (IS_RIP_DEBUG_ZEBRA) {
                struct vrf *nvrf = vrf_lookup_by_id(new_vrf_id);

                zlog_debug("interface %s VRF change vrf %s(%u) new vrf %s(%u)",
                           ifp->name, ifp->vrf->name, vrf_id, VRF_LOGNAME(nvrf),
                           new_vrf_id);
        }

        if_update_to_new_vrf(ifp, new_vrf_id);
        rip_interface_sync(ifp);

        return 0;
}

static void rip_interface_clean(struct rip_interface *ri)
{
        ri->enable_network = 0;
        ri->enable_interface = 0;
        ri->running = 0;

        thread_cancel(&ri->t_wakeup);
}

void rip_interfaces_clean(struct rip *rip)
{
        struct interface *ifp;

        FOR_ALL_INTERFACES (rip->vrf, ifp)
                rip_interface_clean(ifp->info);
}

static void rip_interface_reset(struct rip_interface *ri)
{
        ri->auth_type = yang_get_default_enum("%s/authentication-scheme/mode",
                                              RIP_IFACE);
        ri->md5_auth_len = yang_get_default_enum(
                "%s/authentication-scheme/md5-auth-length", RIP_IFACE);

        /* Set default split-horizon behavior.  If the interface is Frame
           Relay or SMDS is enabled, the default value for split-horizon is
           off.  But currently Zebra does detect Frame Relay or SMDS
           interface.  So all interface is set to split horizon.  */
        ri->split_horizon =
                yang_get_default_enum("%s/split-horizon", RIP_IFACE);

        ri->ri_send = yang_get_default_enum("%s/version-send", RIP_IFACE);
        ri->ri_receive = yang_get_default_enum("%s/version-receive", RIP_IFACE);
        ri->v2_broadcast = yang_get_default_bool("%s/v2-broadcast", RIP_IFACE);

        XFREE(MTYPE_RIP_INTERFACE_STRING, ri->auth_str);

        XFREE(MTYPE_RIP_INTERFACE_STRING, ri->key_chain);

        ri->list[RIP_FILTER_IN] = NULL;
        ri->list[RIP_FILTER_OUT] = NULL;

        ri->prefix[RIP_FILTER_IN] = NULL;
        ri->prefix[RIP_FILTER_OUT] = NULL;

        ri->recv_badpackets = 0;
        ri->recv_badroutes = 0;
        ri->sent_updates = 0;

        ri->passive = 0;

        rip_interface_clean(ri);
}

int rip_if_down(struct interface *ifp)
{
        struct rip *rip;
        struct route_node *rp;
        struct rip_info *rinfo;
        struct rip_interface *ri = NULL;
        struct list *list = NULL;
        struct listnode *listnode = NULL, *nextnode = NULL;

        ri = ifp->info;

        THREAD_OFF(ri->t_wakeup);

        rip = ri->rip;
        if (rip) {
                for (rp = route_top(rip->table); rp; rp = route_next(rp))
                        if ((list = rp->info) != NULL)
                                for (ALL_LIST_ELEMENTS(list, listnode, nextnode,
                                                       rinfo))
                                        if (rinfo->nh.ifindex == ifp->ifindex)
                                                rip_ecmp_delete(rip, rinfo);

                if (ri->running) {
                        if (IS_RIP_DEBUG_EVENT)
                                zlog_debug("turn off %s", ifp->name);

                        /* Leave from multicast group. */
                        rip_multicast_leave(ifp, rip->sock);

                        ri->running = 0;
                }
        }

        return 0;
}

static void rip_apply_address_add(struct connected *ifc)
{
        struct rip_interface *ri = ifc->ifp->info;
        struct rip *rip = ri->rip;
        struct prefix_ipv4 address;
        struct nexthop nh;
        struct prefix *p;

        if (!rip)
                return;

        if (!if_is_up(ifc->ifp))
                return;

        p = ifc->address;

        memset(&address, 0, sizeof(address));
        memset(&nh, 0, sizeof(nh));

        address.family = p->family;
        address.prefix = p->u.prefix4;
        address.prefixlen = p->prefixlen;
        apply_mask_ipv4(&address);

        nh.ifindex = ifc->ifp->ifindex;
        nh.type = NEXTHOP_TYPE_IFINDEX;

        /* Check if this interface is RIP enabled or not
           or  Check if this address's prefix is RIP enabled */
        if ((rip_enable_if_lookup(rip, ifc->ifp->name) >= 0)
            || (rip_enable_network_lookup2(ifc) >= 0))
                rip_redistribute_add(rip, ZEBRA_ROUTE_CONNECT,
                                     RIP_ROUTE_INTERFACE, &address, &nh, 0, 0,
                                     0);
}

int rip_interface_address_add(ZAPI_CALLBACK_ARGS)
{
        struct connected *ifc;
        struct prefix *p;

        ifc = zebra_interface_address_read(ZEBRA_INTERFACE_ADDRESS_ADD,
                                           zclient->ibuf, vrf_id);

        if (ifc == NULL)
                return 0;

        p = ifc->address;

        if (p->family == AF_INET) {
                if (IS_RIP_DEBUG_ZEBRA)
                        zlog_debug("connected address %pFX is added", p);

                rip_enable_apply(ifc->ifp);
                /* Check if this prefix needs to be redistributed */
                rip_apply_address_add(ifc);

                hook_call(rip_ifaddr_add, ifc);
        }

        return 0;
}

static void rip_apply_address_del(struct connected *ifc)
{
        struct rip_interface *ri = ifc->ifp->info;
        struct rip *rip = ri->rip;
        struct prefix_ipv4 address;
        struct prefix *p;

        if (!rip)
                return;

        if (!if_is_up(ifc->ifp))
                return;

        p = ifc->address;

        memset(&address, 0, sizeof(address));
        address.family = p->family;
        address.prefix = p->u.prefix4;
        address.prefixlen = p->prefixlen;
        apply_mask_ipv4(&address);

        rip_redistribute_delete(rip, ZEBRA_ROUTE_CONNECT, RIP_ROUTE_INTERFACE,
                                &address, ifc->ifp->ifindex);
}

int rip_interface_address_delete(ZAPI_CALLBACK_ARGS)
{
        struct connected *ifc;
        struct prefix *p;

        ifc = zebra_interface_address_read(ZEBRA_INTERFACE_ADDRESS_DELETE,
                                           zclient->ibuf, vrf_id);

        if (ifc) {
                p = ifc->address;
                if (p->family == AF_INET) {
                        if (IS_RIP_DEBUG_ZEBRA)
                                zlog_debug("connected address %pFX is deleted",
                                           p);

                        hook_call(rip_ifaddr_del, ifc);

                        /* Chech wether this prefix needs to be removed */
                        rip_apply_address_del(ifc);
                }

                connected_free(&ifc);
        }

        return 0;
}

/* Check interface is enabled by network statement. */
/* Check wether the interface has at least a connected prefix that
 * is within the ripng_enable_network table. */
static int rip_enable_network_lookup_if(struct interface *ifp)
{
        struct rip_interface *ri = ifp->info;
        struct rip *rip = ri->rip;
        struct listnode *node, *nnode;
        struct connected *connected;
        struct prefix_ipv4 address;

        if (!rip)
                return -1;

        for (ALL_LIST_ELEMENTS(ifp->connected, node, nnode, connected)) {
                struct prefix *p;
                struct route_node *n;

                p = connected->address;

                if (p->family == AF_INET) {
                        address.family = AF_INET;
                        address.prefix = p->u.prefix4;
                        address.prefixlen = IPV4_MAX_BITLEN;

                        n = route_node_match(rip->enable_network,
                                             (struct prefix *)&address);
                        if (n) {
                                route_unlock_node(n);
                                return 1;
                        }
                }
        }
        return -1;
}

/* Check wether connected is within the ripng_enable_network table. */
static int rip_enable_network_lookup2(struct connected *connected)
{
        struct rip_interface *ri = connected->ifp->info;
        struct rip *rip = ri->rip;
        struct prefix_ipv4 address;
        struct prefix *p;

        p = connected->address;

        if (p->family == AF_INET) {
                struct route_node *node;

                address.family = p->family;
                address.prefix = p->u.prefix4;
                address.prefixlen = IPV4_MAX_BITLEN;

                /* LPM on p->family, p->u.prefix4/IPV4_MAX_BITLEN within
                 * rip->enable_network */
                node = route_node_match(rip->enable_network,
                                        (struct prefix *)&address);

                if (node) {
                        route_unlock_node(node);
                        return 1;
                }
        }

        return -1;
}
/* Add RIP enable network. */
int rip_enable_network_add(struct rip *rip, struct prefix *p)
{
        struct route_node *node;

        node = route_node_get(rip->enable_network, p);

        if (node->info) {
                route_unlock_node(node);
                return NB_ERR_INCONSISTENCY;
        } else
                node->info = (void *)1;

        /* XXX: One should find a better solution than a generic one */
        rip_enable_apply_all(rip);

        return NB_OK;
}

/* Delete RIP enable network. */
int rip_enable_network_delete(struct rip *rip, struct prefix *p)
{
        struct route_node *node;

        node = route_node_lookup(rip->enable_network, p);
        if (node) {
                node->info = NULL;

                /* Unlock info lock. */
                route_unlock_node(node);

                /* Unlock lookup lock. */
                route_unlock_node(node);

                /* XXX: One should find a better solution than a generic one */
                rip_enable_apply_all(rip);

                return NB_OK;
        }

        return NB_ERR_INCONSISTENCY;
}

/* Check interface is enabled by ifname statement. */
static int rip_enable_if_lookup(struct rip *rip, const char *ifname)
{
        unsigned int i;
        char *str;

        if (!rip)
                return -1;

        for (i = 0; i < vector_active(rip->enable_interface); i++)
                if ((str = vector_slot(rip->enable_interface, i)) != NULL)
                        if (strcmp(str, ifname) == 0)
                                return i;
        return -1;
}

/* Add interface to rip_enable_if. */
int rip_enable_if_add(struct rip *rip, const char *ifname)
{
        int ret;

        ret = rip_enable_if_lookup(rip, ifname);
        if (ret >= 0)
                return NB_ERR_INCONSISTENCY;

        vector_set(rip->enable_interface,
                   XSTRDUP(MTYPE_RIP_INTERFACE_STRING, ifname));

        rip_enable_apply_all(rip); /* TODOVJ */

        return NB_OK;
}

/* Delete interface from rip_enable_if. */
int rip_enable_if_delete(struct rip *rip, const char *ifname)
{
        int index;
        char *str;

        index = rip_enable_if_lookup(rip, ifname);
        if (index < 0)
                return NB_ERR_INCONSISTENCY;

        str = vector_slot(rip->enable_interface, index);
        XFREE(MTYPE_RIP_INTERFACE_STRING, str);
        vector_unset(rip->enable_interface, index);

        rip_enable_apply_all(rip); /* TODOVJ */

        return NB_OK;
}

/* Join to multicast group and send request to the interface. */
static int rip_interface_wakeup(struct thread *t)
{
        struct interface *ifp;
        struct rip_interface *ri;

        /* Get interface. */
        ifp = THREAD_ARG(t);

        ri = ifp->info;

        /* Join to multicast group. */
        if (rip_multicast_join(ifp, ri->rip->sock) < 0) {
                flog_err_sys(EC_LIB_SOCKET,
                             "multicast join failed, interface %s not running",
                             ifp->name);
                return 0;
        }

        /* Set running flag. */
        ri->running = 1;

        /* Send RIP request to the interface. */
        rip_request_interface(ifp);

        return 0;
}

static void rip_connect_set(struct interface *ifp, int set)
{
        struct rip_interface *ri = ifp->info;
        struct rip *rip = ri->rip;
        struct listnode *node, *nnode;
        struct connected *connected;
        struct prefix_ipv4 address;
        struct nexthop nh;

        memset(&nh, 0, sizeof(nh));

        for (ALL_LIST_ELEMENTS(ifp->connected, node, nnode, connected)) {
                struct prefix *p;
                p = connected->address;

                if (p->family != AF_INET)
                        continue;

                address.family = AF_INET;
                address.prefix = p->u.prefix4;
                address.prefixlen = p->prefixlen;
                apply_mask_ipv4(&address);

                nh.ifindex = connected->ifp->ifindex;
                nh.type = NEXTHOP_TYPE_IFINDEX;
                if (set) {
                        /* Check once more wether this prefix is within a
                         * "network IF_OR_PREF" one */
                        if ((rip_enable_if_lookup(rip, connected->ifp->name)
                             >= 0)
                            || (rip_enable_network_lookup2(connected) >= 0))
                                rip_redistribute_add(rip, ZEBRA_ROUTE_CONNECT,
                                                     RIP_ROUTE_INTERFACE,
                                                     &address, &nh, 0, 0, 0);
                } else {
                        rip_redistribute_delete(rip, ZEBRA_ROUTE_CONNECT,
                                                RIP_ROUTE_INTERFACE, &address,
                                                connected->ifp->ifindex);
                        if (rip_redistribute_check(rip, ZEBRA_ROUTE_CONNECT))
                                rip_redistribute_add(rip, ZEBRA_ROUTE_CONNECT,
                                                     RIP_ROUTE_REDISTRIBUTE,
                                                     &address, &nh, 0, 0, 0);
                }
        }
}

/* Update interface status. */
void rip_enable_apply(struct interface *ifp)
{
        int ret;
        struct rip_interface *ri = NULL;

        /* Check interface. */
        if (!if_is_operative(ifp))
                return;

        ri = ifp->info;

        /* Check network configuration. */
        ret = rip_enable_network_lookup_if(ifp);

        /* If the interface is matched. */
        if (ret > 0)
                ri->enable_network = 1;
        else
                ri->enable_network = 0;

        /* Check interface name configuration. */
        ret = rip_enable_if_lookup(ri->rip, ifp->name);
        if (ret >= 0)
                ri->enable_interface = 1;
        else
                ri->enable_interface = 0;

        /* any interface MUST have an IPv4 address */
        if (!rip_if_ipv4_address_check(ifp)) {
                ri->enable_network = 0;
                ri->enable_interface = 0;
        }

        /* Update running status of the interface. */
        if (ri->enable_network || ri->enable_interface) {
                if (IS_RIP_DEBUG_EVENT)
                        zlog_debug("turn on %s", ifp->name);

                /* Add interface wake up thread. */
                thread_add_timer(master, rip_interface_wakeup, ifp, 1,
                                 &ri->t_wakeup);
                rip_connect_set(ifp, 1);
        } else if (ri->running) {
                /* Might as well clean up the route table as well
                 * rip_if_down sets to 0 ri->running, and displays "turn
                 *off %s"
                 **/
                rip_if_down(ifp);

                rip_connect_set(ifp, 0);
        }
}

/* Apply network configuration to all interface. */
static void rip_enable_apply_all(struct rip *rip)
{
        struct interface *ifp;

        /* Check each interface. */
        FOR_ALL_INTERFACES (rip->vrf, ifp)
                rip_enable_apply(ifp);
}

int rip_neighbor_lookup(struct rip *rip, struct sockaddr_in *from)
{
        struct prefix_ipv4 p;
        struct route_node *node;

        memset(&p, 0, sizeof(struct prefix_ipv4));
        p.family = AF_INET;
        p.prefix = from->sin_addr;
        p.prefixlen = IPV4_MAX_BITLEN;

        node = route_node_lookup(rip->neighbor, (struct prefix *)&p);
        if (node) {
                route_unlock_node(node);
                return 1;
        }
        return 0;
}

/* Add new RIP neighbor to the neighbor tree. */
int rip_neighbor_add(struct rip *rip, struct prefix_ipv4 *p)
{
        struct route_node *node;

        node = route_node_get(rip->neighbor, (struct prefix *)p);

        if (node->info)
                return NB_ERR_INCONSISTENCY;

        node->info = rip->neighbor;

        return NB_OK;
}

/* Delete RIP neighbor from the neighbor tree. */
int rip_neighbor_delete(struct rip *rip, struct prefix_ipv4 *p)
{
        struct route_node *node;

        /* Lock for look up. */
        node = route_node_lookup(rip->neighbor, (struct prefix *)p);
        if (!node)
                return NB_ERR_INCONSISTENCY;

        node->info = NULL;

        /* Unlock lookup lock. */
        route_unlock_node(node);

        /* Unlock real neighbor information lock. */
        route_unlock_node(node);

        return NB_OK;
}

/* Clear all network and neighbor configuration. */
void rip_clean_network(struct rip *rip)
{
        unsigned int i;
        char *str;
        struct route_node *rn;

        /* rip->enable_network. */
        for (rn = route_top(rip->enable_network); rn; rn = route_next(rn))
                if (rn->info) {
                        rn->info = NULL;
                        route_unlock_node(rn);
                }

        /* rip->enable_interface. */
        for (i = 0; i < vector_active(rip->enable_interface); i++)
                if ((str = vector_slot(rip->enable_interface, i)) != NULL) {
                        XFREE(MTYPE_RIP_INTERFACE_STRING, str);
                        vector_slot(rip->enable_interface, i) = NULL;
                }
}

/* Utility function for looking up passive interface settings. */
static int rip_passive_nondefault_lookup(struct rip *rip, const char *ifname)
{
        unsigned int i;
        char *str;

        for (i = 0; i < vector_active(rip->passive_nondefault); i++)
                if ((str = vector_slot(rip->passive_nondefault, i)) != NULL)
                        if (strcmp(str, ifname) == 0)
                                return i;
        return -1;
}

static void rip_passive_interface_apply(struct interface *ifp)
{
        struct rip *rip;
        struct rip_interface *ri;

        ri = ifp->info;
        rip = ri->rip;
        if (rip == NULL)
                return;

        ri->passive = ((rip_passive_nondefault_lookup(rip, ifp->name) < 0)
                               ? rip->passive_default
                               : !rip->passive_default);

        if (IS_RIP_DEBUG_ZEBRA)
                zlog_debug("interface %s: passive = %d", ifp->name,
                           ri->passive);
}

static void rip_passive_interface_apply_all(struct rip *rip)
{
        struct interface *ifp;

        FOR_ALL_INTERFACES (rip->vrf, ifp)
                rip_passive_interface_apply(ifp);
}

/* Passive interface. */
int rip_passive_nondefault_set(struct rip *rip, const char *ifname)
{
        if (rip_passive_nondefault_lookup(rip, ifname) >= 0)
                /*
                 * Don't return an error, this can happen after changing
                 * 'passive-default'.
                 */
                return NB_OK;

        vector_set(rip->passive_nondefault,
                   XSTRDUP(MTYPE_RIP_INTERFACE_STRING, ifname));

        rip_passive_interface_apply_all(rip);

        return NB_OK;
}

int rip_passive_nondefault_unset(struct rip *rip, const char *ifname)
{
        int i;
        char *str;

        i = rip_passive_nondefault_lookup(rip, ifname);
        if (i < 0)
                /*
                 * Don't return an error, this can happen after changing
                 * 'passive-default'.
                 */
                return NB_OK;

        str = vector_slot(rip->passive_nondefault, i);
        XFREE(MTYPE_RIP_INTERFACE_STRING, str);
        vector_unset(rip->passive_nondefault, i);

        rip_passive_interface_apply_all(rip);

        return NB_OK;
}

/* Free all configured RIP passive-interface settings. */
void rip_passive_nondefault_clean(struct rip *rip)
{
        unsigned int i;
        char *str;

        for (i = 0; i < vector_active(rip->passive_nondefault); i++)
                if ((str = vector_slot(rip->passive_nondefault, i)) != NULL) {
                        XFREE(MTYPE_RIP_INTERFACE_STRING, str);
                        vector_slot(rip->passive_nondefault, i) = NULL;
                }
        rip_passive_interface_apply_all(rip);
}

int rip_show_network_config(struct vty *vty, struct rip *rip)
{
        unsigned int i;
        char *ifname;
        struct route_node *node;

        /* Network type RIP enable interface statement. */
        for (node = route_top(rip->enable_network); node;
             node = route_next(node))
                if (node->info)
                        vty_out(vty, "    %pFX\n", &node->p);

        /* Interface name RIP enable statement. */
        for (i = 0; i < vector_active(rip->enable_interface); i++)
                if ((ifname = vector_slot(rip->enable_interface, i)) != NULL)
                        vty_out(vty, "    %s\n", ifname);

        /* RIP neighbors listing. */
        for (node = route_top(rip->neighbor); node; node = route_next(node))
                if (node->info)
                        vty_out(vty, "    %pI4\n", &node->p.u.prefix4);

        return 0;
}

void rip_interface_sync(struct interface *ifp)
{
        struct rip_interface *ri;

        ri = ifp->info;
        if (ri)
                ri->rip = ifp->vrf->info;
}

/* Called when interface structure allocated. */
static int rip_interface_new_hook(struct interface *ifp)
{
        ifp->info = rip_interface_new();
        rip_interface_sync(ifp);

        return 0;
}

/* Called when interface structure deleted. */
static int rip_interface_delete_hook(struct interface *ifp)
{
        rip_interface_reset(ifp->info);
        XFREE(MTYPE_RIP_INTERFACE, ifp->info);
        return 0;
}

/* Allocate and initialize interface vector. */
void rip_if_init(void)
{
        /* Default initial size of interface vector. */
        hook_register_prio(if_add, 0, rip_interface_new_hook);
        hook_register_prio(if_del, 0, rip_interface_delete_hook);

        /* Install interface node. */
        if_cmd_init_default();
        if_zapi_callbacks(rip_ifp_create, rip_ifp_up,
                          rip_ifp_down, rip_ifp_destroy);
}