/*
 * net/tipc/bearer.c: TIPC bearer code
 *
 * Copyright (c) 1996-2006, 2013-2016, Ericsson AB
 * Copyright (c) 2004-2006, 2010-2013, Wind River Systems
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <net/sock.h>
#include "core.h"
#include "bearer.h"
#include "link.h"
#include "discover.h"
#include "monitor.h"
#include "bcast.h"
#include "netlink.h"
#include "udp_media.h"
#include "trace.h"
#include "crypto.h"

#define MAX_ADDR_STR 60

static struct tipc_media * const media_info_array[] = {
        &eth_media_info,
#ifdef CONFIG_TIPC_MEDIA_IB
        &ib_media_info,
#endif
#ifdef CONFIG_TIPC_MEDIA_UDP
        &udp_media_info,
#endif
        NULL
};

static struct tipc_bearer *bearer_get(struct net *net, int bearer_id)
{
        struct tipc_net *tn = tipc_net(net);

        return rcu_dereference(tn->bearer_list[bearer_id]);
}

static void bearer_disable(struct net *net, struct tipc_bearer *b);
static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
                           struct packet_type *pt, struct net_device *orig_dev);

/**
 * tipc_media_find - locates specified media object by name
 * @name: name to locate
 */
struct tipc_media *tipc_media_find(const char *name)
{
        u32 i;

        for (i = 0; media_info_array[i] != NULL; i++) {
                if (!strcmp(media_info_array[i]->name, name))
                        break;
        }
        return media_info_array[i];
}

/**
 * media_find_id - locates specified media object by type identifier
 * @type: type identifier to locate
 */
static struct tipc_media *media_find_id(u8 type)
{
        u32 i;

        for (i = 0; media_info_array[i] != NULL; i++) {
                if (media_info_array[i]->type_id == type)
                        break;
        }
        return media_info_array[i];
}

/**
 * tipc_media_addr_printf - record media address in print buffer
 * @buf: output buffer
 * @len: output buffer size remaining
 * @a: input media address
 */
int tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a)
{
        char addr_str[MAX_ADDR_STR];
        struct tipc_media *m;
        int ret;

        m = media_find_id(a->media_id);

        if (m && !m->addr2str(a, addr_str, sizeof(addr_str)))
                ret = scnprintf(buf, len, "%s(%s)", m->name, addr_str);
        else {
                u32 i;

                ret = scnprintf(buf, len, "UNKNOWN(%u)", a->media_id);
                for (i = 0; i < sizeof(a->value); i++)
                        ret += scnprintf(buf + ret, len - ret,
                                            "-%x", a->value[i]);
        }
        return ret;
}

/**
 * bearer_name_validate - validate & (optionally) deconstruct bearer name
 * @name: ptr to bearer name string
 * @name_parts: ptr to area for bearer name components (or NULL if not needed)
 *
 * Return: 1 if bearer name is valid, otherwise 0.
 */
static int bearer_name_validate(const char *name,
                                struct tipc_bearer_names *name_parts)
{
        char name_copy[TIPC_MAX_BEARER_NAME];
        char *media_name;
        char *if_name;
        u32 media_len;
        u32 if_len;

        /* copy bearer name & ensure length is OK */
        if (strscpy(name_copy, name, TIPC_MAX_BEARER_NAME) < 0)
                return 0;

        /* ensure all component parts of bearer name are present */
        media_name = name_copy;
        if_name = strchr(media_name, ':');
        if (if_name == NULL)
                return 0;
        *(if_name++) = 0;
        media_len = if_name - media_name;
        if_len = strlen(if_name) + 1;

        /* validate component parts of bearer name */
        if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) ||
            (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME))
                return 0;

        /* return bearer name components, if necessary */
        if (name_parts) {
                if (strscpy(name_parts->media_name, media_name,
                            TIPC_MAX_MEDIA_NAME) < 0)
                        return 0;
                if (strscpy(name_parts->if_name, if_name,
                            TIPC_MAX_IF_NAME) < 0)
                        return 0;
        }
        return 1;
}

/**
 * tipc_bearer_find - locates bearer object with matching bearer name
 * @net: the applicable net namespace
 * @name: bearer name to locate
 */
struct tipc_bearer *tipc_bearer_find(struct net *net, const char *name)
{
        struct tipc_net *tn = tipc_net(net);
        struct tipc_bearer *b;
        u32 i;

        for (i = 0; i < MAX_BEARERS; i++) {
                b = rtnl_dereference(tn->bearer_list[i]);
                if (b && (!strcmp(b->name, name)))
                        return b;
        }
        return NULL;
}

/*     tipc_bearer_get_name - get the bearer name from its id.
 *     @net: network namespace
 *     @name: a pointer to the buffer where the name will be stored.
 *     @bearer_id: the id to get the name from.
 */
int tipc_bearer_get_name(struct net *net, char *name, u32 bearer_id)
{
        struct tipc_net *tn = tipc_net(net);
        struct tipc_bearer *b;

        if (bearer_id >= MAX_BEARERS)
                return -EINVAL;

        b = rtnl_dereference(tn->bearer_list[bearer_id]);
        if (!b)
                return -EINVAL;

        strcpy(name, b->name);
        return 0;
}

void tipc_bearer_add_dest(struct net *net, u32 bearer_id, u32 dest)
{
        struct tipc_bearer *b;

        rcu_read_lock();
        b = bearer_get(net, bearer_id);
        if (b)
                tipc_disc_add_dest(b->disc);
        rcu_read_unlock();
}

void tipc_bearer_remove_dest(struct net *net, u32 bearer_id, u32 dest)
{
        struct tipc_bearer *b;

        rcu_read_lock();
        b = bearer_get(net, bearer_id);
        if (b)
                tipc_disc_remove_dest(b->disc);
        rcu_read_unlock();
}

/**
 * tipc_enable_bearer - enable bearer with the given name
 * @net: the applicable net namespace
 * @name: bearer name to enable
 * @disc_domain: bearer domain
 * @prio: bearer priority
 * @attr: nlattr array
 * @extack: netlink extended ack
 */
static int tipc_enable_bearer(struct net *net, const char *name,
                              u32 disc_domain, u32 prio,
                              struct nlattr *attr[],
                              struct netlink_ext_ack *extack)
{
        struct tipc_net *tn = tipc_net(net);
        struct tipc_bearer_names b_names;
        int with_this_prio = 1;
        struct tipc_bearer *b;
        struct tipc_media *m;
        struct sk_buff *skb;
        int bearer_id = 0;
        int res = -EINVAL;
        char *errstr = "";
        u32 i;

        if (!bearer_name_validate(name, &b_names)) {
                NL_SET_ERR_MSG(extack, "Illegal name");
                return res;
        }

        if (prio > TIPC_MAX_LINK_PRI && prio != TIPC_MEDIA_LINK_PRI) {
                errstr = "illegal priority";
                NL_SET_ERR_MSG(extack, "Illegal priority");
                goto rejected;
        }

        m = tipc_media_find(b_names.media_name);
        if (!m) {
                errstr = "media not registered";
                NL_SET_ERR_MSG(extack, "Media not registered");
                goto rejected;
        }

        if (prio == TIPC_MEDIA_LINK_PRI)
                prio = m->priority;

        /* Check new bearer vs existing ones and find free bearer id if any */
        bearer_id = MAX_BEARERS;
        i = MAX_BEARERS;
        while (i-- != 0) {
                b = rtnl_dereference(tn->bearer_list[i]);
                if (!b) {
                        bearer_id = i;
                        continue;
                }
                if (!strcmp(name, b->name)) {
                        errstr = "already enabled";
                        NL_SET_ERR_MSG(extack, "Already enabled");
                        goto rejected;
                }

                if (b->priority == prio &&
                    (++with_this_prio > 2)) {
                        pr_warn("Bearer <%s>: already 2 bearers with priority %u\n",
                                name, prio);

                        if (prio == TIPC_MIN_LINK_PRI) {
                                errstr = "cannot adjust to lower";
                                NL_SET_ERR_MSG(extack, "Cannot adjust to lower");
                                goto rejected;
                        }

                        pr_warn("Bearer <%s>: trying with adjusted priority\n",
                                name);
                        prio--;
                        bearer_id = MAX_BEARERS;
                        i = MAX_BEARERS;
                        with_this_prio = 1;
                }
        }

        if (bearer_id >= MAX_BEARERS) {
                errstr = "max 3 bearers permitted";
                NL_SET_ERR_MSG(extack, "Max 3 bearers permitted");
                goto rejected;
        }

        b = kzalloc_obj(*b, GFP_ATOMIC);
        if (!b)
                return -ENOMEM;

        strscpy(b->name, name);
        b->media = m;
        res = m->enable_media(net, b, attr);
        if (res) {
                kfree(b);
                errstr = "failed to enable media";
                NL_SET_ERR_MSG(extack, "Failed to enable media");
                goto rejected;
        }

        b->identity = bearer_id;
        b->tolerance = m->tolerance;
        b->min_win = m->min_win;
        b->max_win = m->max_win;
        b->domain = disc_domain;
        b->net_plane = bearer_id + 'A';
        b->priority = prio;
        refcount_set(&b->refcnt, 1);

        res = tipc_disc_create(net, b, &b->bcast_addr, &skb);
        if (res) {
                bearer_disable(net, b);
                errstr = "failed to create discoverer";
                NL_SET_ERR_MSG(extack, "Failed to create discoverer");
                goto rejected;
        }

        /* Create monitoring data before accepting activate messages */
        if (tipc_mon_create(net, bearer_id)) {
                bearer_disable(net, b);
                kfree_skb(skb);
                return -ENOMEM;
        }

        test_and_set_bit_lock(0, &b->up);
        rcu_assign_pointer(tn->bearer_list[bearer_id], b);
        if (skb)
                tipc_bearer_xmit_skb(net, bearer_id, skb, &b->bcast_addr);

        pr_info("Enabled bearer <%s>, priority %u\n", name, prio);

        return res;
rejected:
        pr_warn("Enabling of bearer <%s> rejected, %s\n", name, errstr);
        return res;
}

/**
 * tipc_reset_bearer - Reset all links established over this bearer
 * @net: the applicable net namespace
 * @b: the target bearer
 */
static int tipc_reset_bearer(struct net *net, struct tipc_bearer *b)
{
        pr_info("Resetting bearer <%s>\n", b->name);
        tipc_node_delete_links(net, b->identity);
        tipc_disc_reset(net, b);
        return 0;
}

bool tipc_bearer_hold(struct tipc_bearer *b)
{
        return (b && refcount_inc_not_zero(&b->refcnt));
}

void tipc_bearer_put(struct tipc_bearer *b)
{
        if (b && refcount_dec_and_test(&b->refcnt))
                kfree_rcu(b, rcu);
}

/**
 * bearer_disable - disable this bearer
 * @net: the applicable net namespace
 * @b: the bearer to disable
 *
 * Note: This routine assumes caller holds RTNL lock.
 */
static void bearer_disable(struct net *net, struct tipc_bearer *b)
{
        struct tipc_net *tn = tipc_net(net);
        int bearer_id = b->identity;

        pr_info("Disabling bearer <%s>\n", b->name);
        clear_bit_unlock(0, &b->up);
        tipc_node_delete_links(net, bearer_id);
        b->media->disable_media(b);
        RCU_INIT_POINTER(b->media_ptr, NULL);
        if (b->disc)
                tipc_disc_delete(b->disc);
        RCU_INIT_POINTER(tn->bearer_list[bearer_id], NULL);
        tipc_bearer_put(b);
        tipc_mon_delete(net, bearer_id);
}

int tipc_enable_l2_media(struct net *net, struct tipc_bearer *b,
                         struct nlattr *attr[])
{
        char *dev_name = strchr((const char *)b->name, ':') + 1;
        int hwaddr_len = b->media->hwaddr_len;
        u8 node_id[NODE_ID_LEN] = {0,};
        struct net_device *dev;

        /* Find device with specified name */
        dev = dev_get_by_name(net, dev_name);
        if (!dev)
                return -ENODEV;
        if (tipc_mtu_bad(dev)) {
                dev_put(dev);
                return -EINVAL;
        }
        if (dev == net->loopback_dev) {
                dev_put(dev);
                pr_info("Enabling <%s> not permitted\n", b->name);
                return -EINVAL;
        }

        /* Autoconfigure own node identity if needed */
        if (!tipc_own_id(net) && hwaddr_len <= NODE_ID_LEN) {
                memcpy(node_id, dev->dev_addr, hwaddr_len);
                tipc_net_init(net, node_id, 0);
        }
        if (!tipc_own_id(net)) {
                dev_put(dev);
                pr_warn("Failed to obtain node identity\n");
                return -EINVAL;
        }

        /* Associate TIPC bearer with L2 bearer */
        rcu_assign_pointer(b->media_ptr, dev);
        b->pt.dev = dev;
        b->pt.type = htons(ETH_P_TIPC);
        b->pt.func = tipc_l2_rcv_msg;
        dev_add_pack(&b->pt);
        memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
        memcpy(b->bcast_addr.value, dev->broadcast, hwaddr_len);
        b->bcast_addr.media_id = b->media->type_id;
        b->bcast_addr.broadcast = TIPC_BROADCAST_SUPPORT;
        b->mtu = dev->mtu;
        b->media->raw2addr(b, &b->addr, (const char *)dev->dev_addr);
        rcu_assign_pointer(dev->tipc_ptr, b);
        return 0;
}

/* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
 * @b: the target bearer
 *
 * Mark L2 bearer as inactive so that incoming buffers are thrown away
 */
void tipc_disable_l2_media(struct tipc_bearer *b)
{
        struct net_device *dev;

        dev = (struct net_device *)rtnl_dereference(b->media_ptr);
        dev_remove_pack(&b->pt);
        RCU_INIT_POINTER(dev->tipc_ptr, NULL);
        synchronize_net();
        dev_put(dev);
}

/**
 * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
 * @net: the associated network namespace
 * @skb: the packet to be sent
 * @b: the bearer through which the packet is to be sent
 * @dest: peer destination address
 */
int tipc_l2_send_msg(struct net *net, struct sk_buff *skb,
                     struct tipc_bearer *b, struct tipc_media_addr *dest)
{
        struct net_device *dev;
        int delta;

        dev = (struct net_device *)rcu_dereference(b->media_ptr);
        if (!dev)
                return 0;

        delta = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
        if ((delta > 0) && pskb_expand_head(skb, delta, 0, GFP_ATOMIC)) {
                kfree_skb(skb);
                return 0;
        }
        skb_reset_network_header(skb);
        skb->dev = dev;
        skb->protocol = htons(ETH_P_TIPC);
        dev_hard_header(skb, dev, ETH_P_TIPC, dest->value,
                        dev->dev_addr, skb->len);
        dev_queue_xmit(skb);
        return 0;
}

bool tipc_bearer_bcast_support(struct net *net, u32 bearer_id)
{
        bool supp = false;
        struct tipc_bearer *b;

        rcu_read_lock();
        b = bearer_get(net, bearer_id);
        if (b)
                supp = (b->bcast_addr.broadcast == TIPC_BROADCAST_SUPPORT);
        rcu_read_unlock();
        return supp;
}

int tipc_bearer_mtu(struct net *net, u32 bearer_id)
{
        int mtu = 0;
        struct tipc_bearer *b;

        rcu_read_lock();
        b = bearer_get(net, bearer_id);
        if (b)
                mtu = b->mtu;
        rcu_read_unlock();
        return mtu;
}

int tipc_bearer_min_mtu(struct net *net, u32 bearer_id)
{
        int mtu = TIPC_MIN_BEARER_MTU;
        struct tipc_bearer *b;

        rcu_read_lock();
        b = bearer_get(net, bearer_id);
        if (b)
                mtu += b->encap_hlen;
        rcu_read_unlock();
        return mtu;
}

/* tipc_bearer_xmit_skb - sends buffer to destination over bearer
 */
void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id,
                          struct sk_buff *skb,
                          struct tipc_media_addr *dest)
{
        struct tipc_msg *hdr = buf_msg(skb);
        struct tipc_bearer *b;

        rcu_read_lock();
        b = bearer_get(net, bearer_id);
        if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {
#ifdef CONFIG_TIPC_CRYPTO
                tipc_crypto_xmit(net, &skb, b, dest, NULL);
                if (skb)
#endif
                        b->media->send_msg(net, skb, b, dest);
        } else {
                kfree_skb(skb);
        }
        rcu_read_unlock();
}

/* tipc_bearer_xmit() -send buffer to destination over bearer
 */
void tipc_bearer_xmit(struct net *net, u32 bearer_id,
                      struct sk_buff_head *xmitq,
                      struct tipc_media_addr *dst,
                      struct tipc_node *__dnode)
{
        struct tipc_bearer *b;
        struct sk_buff *skb, *tmp;

        if (skb_queue_empty(xmitq))
                return;

        rcu_read_lock();
        b = bearer_get(net, bearer_id);
        if (unlikely(!b))
                __skb_queue_purge(xmitq);
        skb_queue_walk_safe(xmitq, skb, tmp) {
                __skb_dequeue(xmitq);
                if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {
#ifdef CONFIG_TIPC_CRYPTO
                        tipc_crypto_xmit(net, &skb, b, dst, __dnode);
                        if (skb)
#endif
                                b->media->send_msg(net, skb, b, dst);
                } else {
                        kfree_skb(skb);
                }
        }
        rcu_read_unlock();
}

/* tipc_bearer_bc_xmit() - broadcast buffers to all destinations
 */
void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,
                         struct sk_buff_head *xmitq)
{
        struct tipc_net *tn = tipc_net(net);
        struct tipc_media_addr *dst;
        int net_id = tn->net_id;
        struct tipc_bearer *b;
        struct sk_buff *skb, *tmp;
        struct tipc_msg *hdr;

        rcu_read_lock();
        b = bearer_get(net, bearer_id);
        if (unlikely(!b || !test_bit(0, &b->up)))
                __skb_queue_purge(xmitq);
        skb_queue_walk_safe(xmitq, skb, tmp) {
                hdr = buf_msg(skb);
                msg_set_non_seq(hdr, 1);
                msg_set_mc_netid(hdr, net_id);
                __skb_dequeue(xmitq);
                dst = &b->bcast_addr;
#ifdef CONFIG_TIPC_CRYPTO
                tipc_crypto_xmit(net, &skb, b, dst, NULL);
                if (skb)
#endif
                        b->media->send_msg(net, skb, b, dst);
        }
        rcu_read_unlock();
}

/**
 * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
 * @skb: the received message
 * @dev: the net device that the packet was received on
 * @pt: the packet_type structure which was used to register this handler
 * @orig_dev: the original receive net device in case the device is a bond
 *
 * Accept only packets explicitly sent to this node, or broadcast packets;
 * ignores packets sent using interface multicast, and traffic sent to other
 * nodes (which can happen if interface is running in promiscuous mode).
 */
static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev,
                           struct packet_type *pt, struct net_device *orig_dev)
{
        struct tipc_bearer *b;

        rcu_read_lock();
        b = rcu_dereference(dev->tipc_ptr) ?:
                rcu_dereference(orig_dev->tipc_ptr);
        if (likely(b && test_bit(0, &b->up) &&
                   (skb->pkt_type <= PACKET_MULTICAST))) {
                skb_mark_not_on_list(skb);
                TIPC_SKB_CB(skb)->flags = 0;
                tipc_rcv(dev_net(b->pt.dev), skb, b);
                rcu_read_unlock();
                return NET_RX_SUCCESS;
        }
        rcu_read_unlock();
        kfree_skb(skb);
        return NET_RX_DROP;
}

/**
 * tipc_l2_device_event - handle device events from network device
 * @nb: the context of the notification
 * @evt: the type of event
 * @ptr: the net device that the event was on
 *
 * This function is called by the Ethernet driver in case of link
 * change event.
 */
static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
                                void *ptr)
{
        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
        struct net *net = dev_net(dev);
        struct tipc_bearer *b;

        b = rtnl_dereference(dev->tipc_ptr);
        if (!b)
                return NOTIFY_DONE;

        trace_tipc_l2_device_event(dev, b, evt);
        switch (evt) {
        case NETDEV_CHANGE:
                if (netif_carrier_ok(dev) && netif_oper_up(dev)) {
                        test_and_set_bit_lock(0, &b->up);
                        break;
                }
                fallthrough;
        case NETDEV_GOING_DOWN:
                clear_bit_unlock(0, &b->up);
                tipc_reset_bearer(net, b);
                break;
        case NETDEV_UP:
                test_and_set_bit_lock(0, &b->up);
                break;
        case NETDEV_CHANGEMTU:
                if (tipc_mtu_bad(dev)) {
                        bearer_disable(net, b);
                        break;
                }
                b->mtu = dev->mtu;
                tipc_reset_bearer(net, b);
                break;
        case NETDEV_CHANGEADDR:
                b->media->raw2addr(b, &b->addr,
                                   (const char *)dev->dev_addr);
                tipc_reset_bearer(net, b);
                break;
        case NETDEV_UNREGISTER:
        case NETDEV_CHANGENAME:
                bearer_disable(net, b);
                break;
        }
        return NOTIFY_OK;
}

static struct notifier_block notifier = {
        .notifier_call  = tipc_l2_device_event,
        .priority       = 0,
};

int tipc_bearer_setup(void)
{
        return register_netdevice_notifier(&notifier);
}

void tipc_bearer_cleanup(void)
{
        unregister_netdevice_notifier(&notifier);
}

void tipc_bearer_stop(struct net *net)
{
        struct tipc_net *tn = tipc_net(net);
        struct tipc_bearer *b;
        u32 i;

        for (i = 0; i < MAX_BEARERS; i++) {
                b = rtnl_dereference(tn->bearer_list[i]);
                if (b) {
                        bearer_disable(net, b);
                        tn->bearer_list[i] = NULL;
                }
        }
}

void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts)
{
        struct net_device *dev = net->loopback_dev;
        struct sk_buff *skb, *_skb;
        int exp;

        skb_queue_walk(pkts, _skb) {
                skb = pskb_copy(_skb, GFP_ATOMIC);
                if (!skb)
                        continue;

                exp = SKB_DATA_ALIGN(dev->hard_header_len - skb_headroom(skb));
                if (exp > 0 && pskb_expand_head(skb, exp, 0, GFP_ATOMIC)) {
                        kfree_skb(skb);
                        continue;
                }

                skb_reset_network_header(skb);
                dev_hard_header(skb, dev, ETH_P_TIPC, dev->dev_addr,
                                dev->dev_addr, skb->len);
                skb->dev = dev;
                skb->pkt_type = PACKET_HOST;
                skb->ip_summed = CHECKSUM_UNNECESSARY;
                skb->protocol = eth_type_trans(skb, dev);
                netif_rx(skb);
        }
}

static int tipc_loopback_rcv_pkt(struct sk_buff *skb, struct net_device *dev,
                                 struct packet_type *pt, struct net_device *od)
{
        consume_skb(skb);
        return NET_RX_SUCCESS;
}

int tipc_attach_loopback(struct net *net)
{
        struct net_device *dev = net->loopback_dev;
        struct tipc_net *tn = tipc_net(net);

        if (!dev)
                return -ENODEV;

        netdev_hold(dev, &tn->loopback_pt.dev_tracker, GFP_KERNEL);
        tn->loopback_pt.dev = dev;
        tn->loopback_pt.type = htons(ETH_P_TIPC);
        tn->loopback_pt.func = tipc_loopback_rcv_pkt;
        dev_add_pack(&tn->loopback_pt);
        return 0;
}

void tipc_detach_loopback(struct net *net)
{
        struct tipc_net *tn = tipc_net(net);

        dev_remove_pack(&tn->loopback_pt);
        netdev_put(net->loopback_dev, &tn->loopback_pt.dev_tracker);
}

/* Caller should hold rtnl_lock to protect the bearer */
static int __tipc_nl_add_bearer(struct tipc_nl_msg *msg,
                                struct tipc_bearer *bearer, int nlflags)
{
        void *hdr;
        struct nlattr *attrs;
        struct nlattr *prop;

        hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
                          nlflags, TIPC_NL_BEARER_GET);
        if (!hdr)
                return -EMSGSIZE;

        attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER);
        if (!attrs)
                goto msg_full;

        if (nla_put_string(msg->skb, TIPC_NLA_BEARER_NAME, bearer->name))
                goto attr_msg_full;

        prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_BEARER_PROP);
        if (!prop)
                goto prop_msg_full;
        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, bearer->priority))
                goto prop_msg_full;
        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, bearer->tolerance))
                goto prop_msg_full;
        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bearer->max_win))
                goto prop_msg_full;
        if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP)
                if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, bearer->mtu))
                        goto prop_msg_full;

        nla_nest_end(msg->skb, prop);

#ifdef CONFIG_TIPC_MEDIA_UDP
        if (bearer->media->type_id == TIPC_MEDIA_TYPE_UDP) {
                if (tipc_udp_nl_add_bearer_data(msg, bearer))
                        goto attr_msg_full;
        }
#endif

        nla_nest_end(msg->skb, attrs);
        genlmsg_end(msg->skb, hdr);

        return 0;

prop_msg_full:
        nla_nest_cancel(msg->skb, prop);
attr_msg_full:
        nla_nest_cancel(msg->skb, attrs);
msg_full:
        genlmsg_cancel(msg->skb, hdr);

        return -EMSGSIZE;
}

int tipc_nl_bearer_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
        int err;
        int i = cb->args[0];
        struct tipc_bearer *bearer;
        struct tipc_nl_msg msg;
        struct net *net = sock_net(skb->sk);
        struct tipc_net *tn = tipc_net(net);

        if (i == MAX_BEARERS)
                return 0;

        msg.skb = skb;
        msg.portid = NETLINK_CB(cb->skb).portid;
        msg.seq = cb->nlh->nlmsg_seq;

        rtnl_lock();
        for (i = 0; i < MAX_BEARERS; i++) {
                bearer = rtnl_dereference(tn->bearer_list[i]);
                if (!bearer)
                        continue;

                err = __tipc_nl_add_bearer(&msg, bearer, NLM_F_MULTI);
                if (err)
                        break;
        }
        rtnl_unlock();

        cb->args[0] = i;
        return skb->len;
}

int tipc_nl_bearer_get(struct sk_buff *skb, struct genl_info *info)
{
        int err;
        char *name;
        struct sk_buff *rep;
        struct tipc_bearer *bearer;
        struct tipc_nl_msg msg;
        struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
        struct net *net = genl_info_net(info);

        if (!info->attrs[TIPC_NLA_BEARER])
                return -EINVAL;

        err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
                                          info->attrs[TIPC_NLA_BEARER],
                                          tipc_nl_bearer_policy, info->extack);
        if (err)
                return err;

        if (!attrs[TIPC_NLA_BEARER_NAME])
                return -EINVAL;
        name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);

        rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
        if (!rep)
                return -ENOMEM;

        msg.skb = rep;
        msg.portid = info->snd_portid;
        msg.seq = info->snd_seq;

        rtnl_lock();
        bearer = tipc_bearer_find(net, name);
        if (!bearer) {
                err = -EINVAL;
                NL_SET_ERR_MSG(info->extack, "Bearer not found");
                goto err_out;
        }

        err = __tipc_nl_add_bearer(&msg, bearer, 0);
        if (err)
                goto err_out;
        rtnl_unlock();

        return genlmsg_reply(rep, info);
err_out:
        rtnl_unlock();
        nlmsg_free(rep);

        return err;
}

int __tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
{
        int err;
        char *name;
        struct tipc_bearer *bearer;
        struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
        struct net *net = sock_net(skb->sk);

        if (!info->attrs[TIPC_NLA_BEARER])
                return -EINVAL;

        err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
                                          info->attrs[TIPC_NLA_BEARER],
                                          tipc_nl_bearer_policy, info->extack);
        if (err)
                return err;

        if (!attrs[TIPC_NLA_BEARER_NAME])
                return -EINVAL;

        name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);

        bearer = tipc_bearer_find(net, name);
        if (!bearer) {
                NL_SET_ERR_MSG(info->extack, "Bearer not found");
                return -EINVAL;
        }

        bearer_disable(net, bearer);

        return 0;
}

int tipc_nl_bearer_disable(struct sk_buff *skb, struct genl_info *info)
{
        int err;

        rtnl_lock();
        err = __tipc_nl_bearer_disable(skb, info);
        rtnl_unlock();

        return err;
}

int __tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
{
        int err;
        char *bearer;
        struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
        struct net *net = sock_net(skb->sk);
        u32 domain = 0;
        u32 prio;

        prio = TIPC_MEDIA_LINK_PRI;

        if (!info->attrs[TIPC_NLA_BEARER])
                return -EINVAL;

        err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
                                          info->attrs[TIPC_NLA_BEARER],
                                          tipc_nl_bearer_policy, info->extack);
        if (err)
                return err;

        if (!attrs[TIPC_NLA_BEARER_NAME])
                return -EINVAL;

        bearer = nla_data(attrs[TIPC_NLA_BEARER_NAME]);

        if (attrs[TIPC_NLA_BEARER_DOMAIN])
                domain = nla_get_u32(attrs[TIPC_NLA_BEARER_DOMAIN]);

        if (attrs[TIPC_NLA_BEARER_PROP]) {
                struct nlattr *props[TIPC_NLA_PROP_MAX + 1];

                err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
                                              props);
                if (err)
                        return err;

                if (props[TIPC_NLA_PROP_PRIO])
                        prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
        }

        return tipc_enable_bearer(net, bearer, domain, prio, attrs,
                                  info->extack);
}

int tipc_nl_bearer_enable(struct sk_buff *skb, struct genl_info *info)
{
        int err;

        rtnl_lock();
        err = __tipc_nl_bearer_enable(skb, info);
        rtnl_unlock();

        return err;
}

int tipc_nl_bearer_add(struct sk_buff *skb, struct genl_info *info)
{
        int err;
        char *name;
        struct tipc_bearer *b;
        struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
        struct net *net = sock_net(skb->sk);

        if (!info->attrs[TIPC_NLA_BEARER])
                return -EINVAL;

        err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
                                          info->attrs[TIPC_NLA_BEARER],
                                          tipc_nl_bearer_policy, info->extack);
        if (err)
                return err;

        if (!attrs[TIPC_NLA_BEARER_NAME])
                return -EINVAL;
        name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);

        rtnl_lock();
        b = tipc_bearer_find(net, name);
        if (!b) {
                NL_SET_ERR_MSG(info->extack, "Bearer not found");
                err = -EINVAL;
                goto out;
        }

#ifdef CONFIG_TIPC_MEDIA_UDP
        if (attrs[TIPC_NLA_BEARER_UDP_OPTS]) {
                if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
                        NL_SET_ERR_MSG(info->extack, "UDP option is unsupported");
                        err = -EINVAL;
                        goto out;
                }

                err = tipc_udp_nl_bearer_add(b,
                                             attrs[TIPC_NLA_BEARER_UDP_OPTS]);
        }
#endif
out:
        rtnl_unlock();

        return err;
}

int __tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
{
        struct tipc_bearer *b;
        struct nlattr *attrs[TIPC_NLA_BEARER_MAX + 1];
        struct net *net = sock_net(skb->sk);
        char *name;
        int err;

        if (!info->attrs[TIPC_NLA_BEARER])
                return -EINVAL;

        err = nla_parse_nested_deprecated(attrs, TIPC_NLA_BEARER_MAX,
                                          info->attrs[TIPC_NLA_BEARER],
                                          tipc_nl_bearer_policy, info->extack);
        if (err)
                return err;

        if (!attrs[TIPC_NLA_BEARER_NAME])
                return -EINVAL;
        name = nla_data(attrs[TIPC_NLA_BEARER_NAME]);

        b = tipc_bearer_find(net, name);
        if (!b) {
                NL_SET_ERR_MSG(info->extack, "Bearer not found");
                return -EINVAL;
        }

        if (attrs[TIPC_NLA_BEARER_PROP]) {
                struct nlattr *props[TIPC_NLA_PROP_MAX + 1];

                err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_BEARER_PROP],
                                              props);
                if (err)
                        return err;

                if (props[TIPC_NLA_PROP_TOL]) {
                        b->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
                        tipc_node_apply_property(net, b, TIPC_NLA_PROP_TOL);
                }
                if (props[TIPC_NLA_PROP_PRIO])
                        b->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
                if (props[TIPC_NLA_PROP_WIN])
                        b->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
                if (props[TIPC_NLA_PROP_MTU]) {
                        if (b->media->type_id != TIPC_MEDIA_TYPE_UDP) {
                                NL_SET_ERR_MSG(info->extack,
                                               "MTU property is unsupported");
                                return -EINVAL;
                        }
#ifdef CONFIG_TIPC_MEDIA_UDP
                        if (nla_get_u32(props[TIPC_NLA_PROP_MTU]) <
                            b->encap_hlen + TIPC_MIN_BEARER_MTU) {
                                NL_SET_ERR_MSG(info->extack,
                                               "MTU value is out-of-range");
                                return -EINVAL;
                        }
                        b->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
                        tipc_node_apply_property(net, b, TIPC_NLA_PROP_MTU);
#endif
                }
        }

        return 0;
}

int tipc_nl_bearer_set(struct sk_buff *skb, struct genl_info *info)
{
        int err;

        rtnl_lock();
        err = __tipc_nl_bearer_set(skb, info);
        rtnl_unlock();

        return err;
}

static int __tipc_nl_add_media(struct tipc_nl_msg *msg,
                               struct tipc_media *media, int nlflags)
{
        void *hdr;
        struct nlattr *attrs;
        struct nlattr *prop;

        hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
                          nlflags, TIPC_NL_MEDIA_GET);
        if (!hdr)
                return -EMSGSIZE;

        attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA);
        if (!attrs)
                goto msg_full;

        if (nla_put_string(msg->skb, TIPC_NLA_MEDIA_NAME, media->name))
                goto attr_msg_full;

        prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_MEDIA_PROP);
        if (!prop)
                goto prop_msg_full;
        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, media->priority))
                goto prop_msg_full;
        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, media->tolerance))
                goto prop_msg_full;
        if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, media->max_win))
                goto prop_msg_full;
        if (media->type_id == TIPC_MEDIA_TYPE_UDP)
                if (nla_put_u32(msg->skb, TIPC_NLA_PROP_MTU, media->mtu))
                        goto prop_msg_full;

        nla_nest_end(msg->skb, prop);
        nla_nest_end(msg->skb, attrs);
        genlmsg_end(msg->skb, hdr);

        return 0;

prop_msg_full:
        nla_nest_cancel(msg->skb, prop);
attr_msg_full:
        nla_nest_cancel(msg->skb, attrs);
msg_full:
        genlmsg_cancel(msg->skb, hdr);

        return -EMSGSIZE;
}

int tipc_nl_media_dump(struct sk_buff *skb, struct netlink_callback *cb)
{
        int err;
        int i = cb->args[0];
        struct tipc_nl_msg msg;

        if (i == MAX_MEDIA)
                return 0;

        msg.skb = skb;
        msg.portid = NETLINK_CB(cb->skb).portid;
        msg.seq = cb->nlh->nlmsg_seq;

        rtnl_lock();
        for (; media_info_array[i] != NULL; i++) {
                err = __tipc_nl_add_media(&msg, media_info_array[i],
                                          NLM_F_MULTI);
                if (err)
                        break;
        }
        rtnl_unlock();

        cb->args[0] = i;
        return skb->len;
}

int tipc_nl_media_get(struct sk_buff *skb, struct genl_info *info)
{
        int err;
        char *name;
        struct tipc_nl_msg msg;
        struct tipc_media *media;
        struct sk_buff *rep;
        struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];

        if (!info->attrs[TIPC_NLA_MEDIA])
                return -EINVAL;

        err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
                                          info->attrs[TIPC_NLA_MEDIA],
                                          tipc_nl_media_policy, info->extack);
        if (err)
                return err;

        if (!attrs[TIPC_NLA_MEDIA_NAME])
                return -EINVAL;
        name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);

        rep = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
        if (!rep)
                return -ENOMEM;

        msg.skb = rep;
        msg.portid = info->snd_portid;
        msg.seq = info->snd_seq;

        rtnl_lock();
        media = tipc_media_find(name);
        if (!media) {
                NL_SET_ERR_MSG(info->extack, "Media not found");
                err = -EINVAL;
                goto err_out;
        }

        err = __tipc_nl_add_media(&msg, media, 0);
        if (err)
                goto err_out;
        rtnl_unlock();

        return genlmsg_reply(rep, info);
err_out:
        rtnl_unlock();
        nlmsg_free(rep);

        return err;
}

int __tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
{
        int err;
        char *name;
        struct tipc_media *m;
        struct nlattr *attrs[TIPC_NLA_MEDIA_MAX + 1];

        if (!info->attrs[TIPC_NLA_MEDIA])
                return -EINVAL;

        err = nla_parse_nested_deprecated(attrs, TIPC_NLA_MEDIA_MAX,
                                          info->attrs[TIPC_NLA_MEDIA],
                                          tipc_nl_media_policy, info->extack);

        if (!attrs[TIPC_NLA_MEDIA_NAME])
                return -EINVAL;
        name = nla_data(attrs[TIPC_NLA_MEDIA_NAME]);

        m = tipc_media_find(name);
        if (!m) {
                NL_SET_ERR_MSG(info->extack, "Media not found");
                return -EINVAL;
        }
        if (attrs[TIPC_NLA_MEDIA_PROP]) {
                struct nlattr *props[TIPC_NLA_PROP_MAX + 1];

                err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_MEDIA_PROP],
                                              props);
                if (err)
                        return err;

                if (props[TIPC_NLA_PROP_TOL])
                        m->tolerance = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
                if (props[TIPC_NLA_PROP_PRIO])
                        m->priority = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
                if (props[TIPC_NLA_PROP_WIN])
                        m->max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
                if (props[TIPC_NLA_PROP_MTU]) {
                        if (m->type_id != TIPC_MEDIA_TYPE_UDP) {
                                NL_SET_ERR_MSG(info->extack,
                                               "MTU property is unsupported");
                                return -EINVAL;
                        }
#ifdef CONFIG_TIPC_MEDIA_UDP
                        if (tipc_udp_mtu_bad(nla_get_u32
                                             (props[TIPC_NLA_PROP_MTU]))) {
                                NL_SET_ERR_MSG(info->extack,
                                               "MTU value is out-of-range");
                                return -EINVAL;
                        }
                        m->mtu = nla_get_u32(props[TIPC_NLA_PROP_MTU]);
#endif
                }
        }

        return 0;
}

int tipc_nl_media_set(struct sk_buff *skb, struct genl_info *info)
{
        int err;

        rtnl_lock();
        err = __tipc_nl_media_set(skb, info);
        rtnl_unlock();

        return err;
}