/*
 * Copyright (c) 2005 Voltaire Inc.  All rights reserved.
 * Copyright (c) 2002-2005, Network Appliance, Inc. All rights reserved.
 * Copyright (c) 1999-2005, Mellanox Technologies, Inc. All rights reserved.
 * Copyright (c) 2005 Intel Corporation.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - 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.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/mutex.h>
#include <linux/inetdevice.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/module.h>
#include <net/arp.h>
#include <net/neighbour.h>
#include <net/route.h>
#include <net/netevent.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <rdma/ib_addr.h>
#include <rdma/ib.h>
#include <rdma/rdma_netlink.h>
#include <net/netlink.h>

#include "core_priv.h"

struct addr_req {
        struct list_head list;
        struct sockaddr_storage src_addr;
        struct sockaddr_storage dst_addr;
        struct rdma_dev_addr *addr;
        struct rdma_addr_client *client;
        void *context;
        void (*callback)(int status, struct sockaddr *src_addr,
                         struct rdma_dev_addr *addr, void *context);
        unsigned long timeout;
        struct delayed_work work;
        int status;
        u32 seq;
};

static atomic_t ib_nl_addr_request_seq = ATOMIC_INIT(0);

static void process_req(struct work_struct *work);

static DEFINE_MUTEX(lock);
static LIST_HEAD(req_list);
static DECLARE_DELAYED_WORK(work, process_req);
static struct workqueue_struct *addr_wq;

static const struct nla_policy ib_nl_addr_policy[LS_NLA_TYPE_MAX] = {
        [LS_NLA_TYPE_DGID] = {.type = NLA_BINARY,
                .len = sizeof(struct rdma_nla_ls_gid)},
};

static inline bool ib_nl_is_good_ip_resp(const struct nlmsghdr *nlh)
{
        struct nlattr *tb[LS_NLA_TYPE_MAX] = {};
        int ret;

        if (nlh->nlmsg_flags & RDMA_NL_LS_F_ERR)
                return false;

        ret = nla_parse(tb, LS_NLA_TYPE_MAX - 1, nlmsg_data(nlh),
                        nlmsg_len(nlh), ib_nl_addr_policy, NULL);
        if (ret)
                return false;

        return true;
}

static void ib_nl_process_good_ip_rsep(const struct nlmsghdr *nlh)
{
        const struct nlattr *head, *curr;
        union ib_gid gid;
        struct addr_req *req;
        int len, rem;
        int found = 0;

        head = (const struct nlattr *)nlmsg_data(nlh);
        len = nlmsg_len(nlh);

        nla_for_each_attr(curr, head, len, rem) {
                if (curr->nla_type == LS_NLA_TYPE_DGID)
                        memcpy(&gid, nla_data(curr), nla_len(curr));
        }

        mutex_lock(&lock);
        list_for_each_entry(req, &req_list, list) {
                if (nlh->nlmsg_seq != req->seq)
                        continue;
                /* We set the DGID part, the rest was set earlier */
                rdma_addr_set_dgid(req->addr, &gid);
                req->status = 0;
                found = 1;
                break;
        }
        mutex_unlock(&lock);

        if (!found)
                pr_info("Couldn't find request waiting for DGID: %pI6\n",
                        &gid);
}

int ib_nl_handle_ip_res_resp(struct sk_buff *skb,
                             struct netlink_callback *cb)
{
        const struct nlmsghdr *nlh = (struct nlmsghdr *)cb->nlh;

        if ((nlh->nlmsg_flags & NLM_F_REQUEST) ||
            !(NETLINK_CB(skb).sk) ||
            !netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;

        if (ib_nl_is_good_ip_resp(nlh))
                ib_nl_process_good_ip_rsep(nlh);

        return skb->len;
}

static int ib_nl_ip_send_msg(struct rdma_dev_addr *dev_addr,
                             const void *daddr,
                             u32 seq, u16 family)
{
        struct sk_buff *skb = NULL;
        struct nlmsghdr *nlh;
        struct rdma_ls_ip_resolve_header *header;
        void *data;
        size_t size;
        int attrtype;
        int len;

        if (family == AF_INET) {
                size = sizeof(struct in_addr);
                attrtype = RDMA_NLA_F_MANDATORY | LS_NLA_TYPE_IPV4;
        } else {
                size = sizeof(struct in6_addr);
                attrtype = RDMA_NLA_F_MANDATORY | LS_NLA_TYPE_IPV6;
        }

        len = nla_total_size(sizeof(size));
        len += NLMSG_ALIGN(sizeof(*header));

        skb = nlmsg_new(len, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;

        data = ibnl_put_msg(skb, &nlh, seq, 0, RDMA_NL_LS,
                            RDMA_NL_LS_OP_IP_RESOLVE, NLM_F_REQUEST);
        if (!data) {
                nlmsg_free(skb);
                return -ENODATA;
        }

        /* Construct the family header first */
        header = skb_put(skb, NLMSG_ALIGN(sizeof(*header)));
        header->ifindex = dev_addr->bound_dev_if;
        nla_put(skb, attrtype, size, daddr);

        /* Repair the nlmsg header length */
        nlmsg_end(skb, nlh);
        ibnl_multicast(skb, nlh, RDMA_NL_GROUP_LS, GFP_KERNEL);

        /* Make the request retry, so when we get the response from userspace
         * we will have something.
         */
        return -ENODATA;
}

int rdma_addr_size(struct sockaddr *addr)
{
        switch (addr->sa_family) {
        case AF_INET:
                return sizeof(struct sockaddr_in);
        case AF_INET6:
                return sizeof(struct sockaddr_in6);
        case AF_IB:
                return sizeof(struct sockaddr_ib);
        default:
                return 0;
        }
}
EXPORT_SYMBOL(rdma_addr_size);

static struct rdma_addr_client self;

void rdma_addr_register_client(struct rdma_addr_client *client)
{
        atomic_set(&client->refcount, 1);
        init_completion(&client->comp);
}
EXPORT_SYMBOL(rdma_addr_register_client);

static inline void put_client(struct rdma_addr_client *client)
{
        if (atomic_dec_and_test(&client->refcount))
                complete(&client->comp);
}

void rdma_addr_unregister_client(struct rdma_addr_client *client)
{
        put_client(client);
        wait_for_completion(&client->comp);
}
EXPORT_SYMBOL(rdma_addr_unregister_client);

int rdma_copy_addr(struct rdma_dev_addr *dev_addr, struct net_device *dev,
                     const unsigned char *dst_dev_addr)
{
        dev_addr->dev_type = dev->type;
        memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
        memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
        if (dst_dev_addr)
                memcpy(dev_addr->dst_dev_addr, dst_dev_addr, MAX_ADDR_LEN);
        dev_addr->bound_dev_if = dev->ifindex;
        return 0;
}
EXPORT_SYMBOL(rdma_copy_addr);

int rdma_translate_ip(const struct sockaddr *addr,
                      struct rdma_dev_addr *dev_addr,
                      u16 *vlan_id)
{
        struct net_device *dev;
        int ret = -EADDRNOTAVAIL;

        if (dev_addr->bound_dev_if) {
                dev = dev_get_by_index(dev_addr->net, dev_addr->bound_dev_if);
                if (!dev)
                        return -ENODEV;
                ret = rdma_copy_addr(dev_addr, dev, NULL);
                dev_put(dev);
                return ret;
        }

        switch (addr->sa_family) {
        case AF_INET:
                dev = ip_dev_find(dev_addr->net,
                        ((const struct sockaddr_in *)addr)->sin_addr.s_addr);

                if (!dev)
                        return ret;

                ret = rdma_copy_addr(dev_addr, dev, NULL);
                dev_addr->bound_dev_if = dev->ifindex;
                if (vlan_id)
                        *vlan_id = rdma_vlan_dev_vlan_id(dev);
                dev_put(dev);
                break;
#if IS_ENABLED(CONFIG_IPV6)
        case AF_INET6:
                rcu_read_lock();
                for_each_netdev_rcu(dev_addr->net, dev) {
                        if (ipv6_chk_addr(dev_addr->net,
                                          &((const struct sockaddr_in6 *)addr)->sin6_addr,
                                          dev, 1)) {
                                ret = rdma_copy_addr(dev_addr, dev, NULL);
                                dev_addr->bound_dev_if = dev->ifindex;
                                if (vlan_id)
                                        *vlan_id = rdma_vlan_dev_vlan_id(dev);
                                break;
                        }
                }
                rcu_read_unlock();
                break;
#endif
        }
        return ret;
}
EXPORT_SYMBOL(rdma_translate_ip);

static void set_timeout(struct delayed_work *delayed_work, unsigned long time)
{
        unsigned long delay;

        delay = time - jiffies;
        if ((long)delay < 0)
                delay = 0;

        mod_delayed_work(addr_wq, delayed_work, delay);
}

static void queue_req(struct addr_req *req)
{
        struct addr_req *temp_req;

        mutex_lock(&lock);
        list_for_each_entry_reverse(temp_req, &req_list, list) {
                if (time_after_eq(req->timeout, temp_req->timeout))
                        break;
        }

        list_add(&req->list, &temp_req->list);

        set_timeout(&req->work, req->timeout);
        mutex_unlock(&lock);
}

static int ib_nl_fetch_ha(struct dst_entry *dst, struct rdma_dev_addr *dev_addr,
                          const void *daddr, u32 seq, u16 family)
{
        if (ibnl_chk_listeners(RDMA_NL_GROUP_LS))
                return -EADDRNOTAVAIL;

        /* We fill in what we can, the response will fill the rest */
        rdma_copy_addr(dev_addr, dst->dev, NULL);
        return ib_nl_ip_send_msg(dev_addr, daddr, seq, family);
}

static int dst_fetch_ha(struct dst_entry *dst, struct rdma_dev_addr *dev_addr,
                        const void *daddr)
{
        struct neighbour *n;
        int ret;

        n = dst_neigh_lookup(dst, daddr);

        rcu_read_lock();
        if (!n || !(n->nud_state & NUD_VALID)) {
                if (n)
                        neigh_event_send(n, NULL);
                ret = -ENODATA;
        } else {
                ret = rdma_copy_addr(dev_addr, dst->dev, n->ha);
        }
        rcu_read_unlock();

        if (n)
                neigh_release(n);

        return ret;
}

static bool has_gateway(struct dst_entry *dst, sa_family_t family)
{
        struct rtable *rt;
        struct rt6_info *rt6;

        if (family == AF_INET) {
                rt = container_of(dst, struct rtable, dst);
                return rt->rt_uses_gateway;
        }

        rt6 = container_of(dst, struct rt6_info, dst);
        return rt6->rt6i_flags & RTF_GATEWAY;
}

static int fetch_ha(struct dst_entry *dst, struct rdma_dev_addr *dev_addr,
                    const struct sockaddr *dst_in, u32 seq)
{
        const struct sockaddr_in *dst_in4 =
                (const struct sockaddr_in *)dst_in;
        const struct sockaddr_in6 *dst_in6 =
                (const struct sockaddr_in6 *)dst_in;
        const void *daddr = (dst_in->sa_family == AF_INET) ?
                (const void *)&dst_in4->sin_addr.s_addr :
                (const void *)&dst_in6->sin6_addr;
        sa_family_t family = dst_in->sa_family;

        /* Gateway + ARPHRD_INFINIBAND -> IB router */
        if (has_gateway(dst, family) && dst->dev->type == ARPHRD_INFINIBAND)
                return ib_nl_fetch_ha(dst, dev_addr, daddr, seq, family);
        else
                return dst_fetch_ha(dst, dev_addr, daddr);
}

static int addr4_resolve(struct sockaddr_in *src_in,
                         const struct sockaddr_in *dst_in,
                         struct rdma_dev_addr *addr,
                         struct rtable **prt)
{
        __be32 src_ip = src_in->sin_addr.s_addr;
        __be32 dst_ip = dst_in->sin_addr.s_addr;
        struct rtable *rt;
        struct flowi4 fl4;
        int ret;

        memset(&fl4, 0, sizeof(fl4));
        fl4.daddr = dst_ip;
        fl4.saddr = src_ip;
        fl4.flowi4_oif = addr->bound_dev_if;
        rt = ip_route_output_key(addr->net, &fl4);
        ret = PTR_ERR_OR_ZERO(rt);
        if (ret)
                return ret;

        src_in->sin_family = AF_INET;
        src_in->sin_addr.s_addr = fl4.saddr;

        /* If there's a gateway and type of device not ARPHRD_INFINIBAND, we're
         * definitely in RoCE v2 (as RoCE v1 isn't routable) set the network
         * type accordingly.
         */
        if (rt->rt_uses_gateway && rt->dst.dev->type != ARPHRD_INFINIBAND)
                addr->network = RDMA_NETWORK_IPV4;

        addr->hoplimit = ip4_dst_hoplimit(&rt->dst);

        *prt = rt;
        return 0;
}

#if IS_ENABLED(CONFIG_IPV6)
static int addr6_resolve(struct sockaddr_in6 *src_in,
                         const struct sockaddr_in6 *dst_in,
                         struct rdma_dev_addr *addr,
                         struct dst_entry **pdst)
{
        struct flowi6 fl6;
        struct dst_entry *dst;
        struct rt6_info *rt;
        int ret;

        memset(&fl6, 0, sizeof fl6);
        fl6.daddr = dst_in->sin6_addr;
        fl6.saddr = src_in->sin6_addr;
        fl6.flowi6_oif = addr->bound_dev_if;

        ret = ipv6_stub->ipv6_dst_lookup(addr->net, NULL, &dst, &fl6);
        if (ret < 0)
                return ret;

        rt = (struct rt6_info *)dst;
        if (ipv6_addr_any(&src_in->sin6_addr)) {
                src_in->sin6_family = AF_INET6;
                src_in->sin6_addr = fl6.saddr;
        }

        /* If there's a gateway and type of device not ARPHRD_INFINIBAND, we're
         * definitely in RoCE v2 (as RoCE v1 isn't routable) set the network
         * type accordingly.
         */
        if (rt->rt6i_flags & RTF_GATEWAY &&
            ip6_dst_idev(dst)->dev->type != ARPHRD_INFINIBAND)
                addr->network = RDMA_NETWORK_IPV6;

        addr->hoplimit = ip6_dst_hoplimit(dst);

        *pdst = dst;
        return 0;
}
#else
static int addr6_resolve(struct sockaddr_in6 *src_in,
                         const struct sockaddr_in6 *dst_in,
                         struct rdma_dev_addr *addr,
                         struct dst_entry **pdst)
{
        return -EADDRNOTAVAIL;
}
#endif

static int addr_resolve_neigh(struct dst_entry *dst,
                              const struct sockaddr *dst_in,
                              struct rdma_dev_addr *addr,
                              u32 seq)
{
        if (dst->dev->flags & IFF_LOOPBACK) {
                int ret;

                ret = rdma_translate_ip(dst_in, addr, NULL);
                if (!ret)
                        memcpy(addr->dst_dev_addr, addr->src_dev_addr,
                               MAX_ADDR_LEN);

                return ret;
        }

        /* If the device doesn't do ARP internally */
        if (!(dst->dev->flags & IFF_NOARP))
                return fetch_ha(dst, addr, dst_in, seq);

        return rdma_copy_addr(addr, dst->dev, NULL);
}

static int addr_resolve(struct sockaddr *src_in,
                        const struct sockaddr *dst_in,
                        struct rdma_dev_addr *addr,
                        bool resolve_neigh,
                        u32 seq)
{
        struct net_device *ndev;
        struct dst_entry *dst;
        int ret;

        if (!addr->net) {
                pr_warn_ratelimited("%s: missing namespace\n", __func__);
                return -EINVAL;
        }

        if (src_in->sa_family == AF_INET) {
                struct rtable *rt = NULL;
                const struct sockaddr_in *dst_in4 =
                        (const struct sockaddr_in *)dst_in;

                ret = addr4_resolve((struct sockaddr_in *)src_in,
                                    dst_in4, addr, &rt);
                if (ret)
                        return ret;

                if (resolve_neigh)
                        ret = addr_resolve_neigh(&rt->dst, dst_in, addr, seq);

                if (addr->bound_dev_if) {
                        ndev = dev_get_by_index(addr->net, addr->bound_dev_if);
                } else {
                        ndev = rt->dst.dev;
                        dev_hold(ndev);
                }

                ip_rt_put(rt);
        } else {
                const struct sockaddr_in6 *dst_in6 =
                        (const struct sockaddr_in6 *)dst_in;

                ret = addr6_resolve((struct sockaddr_in6 *)src_in,
                                    dst_in6, addr,
                                    &dst);
                if (ret)
                        return ret;

                if (resolve_neigh)
                        ret = addr_resolve_neigh(dst, dst_in, addr, seq);

                if (addr->bound_dev_if) {
                        ndev = dev_get_by_index(addr->net, addr->bound_dev_if);
                } else {
                        ndev = dst->dev;
                        dev_hold(ndev);
                }

                dst_release(dst);
        }

        if (ndev->flags & IFF_LOOPBACK) {
                ret = rdma_translate_ip(dst_in, addr, NULL);
                /*
                 * Put the loopback device and get the translated
                 * device instead.
                 */
                dev_put(ndev);
                ndev = dev_get_by_index(addr->net, addr->bound_dev_if);
        } else {
                addr->bound_dev_if = ndev->ifindex;
        }
        dev_put(ndev);

        return ret;
}

static void process_one_req(struct work_struct *_work)
{
        struct addr_req *req;
        struct sockaddr *src_in, *dst_in;

        mutex_lock(&lock);
        req = container_of(_work, struct addr_req, work.work);

        if (req->status == -ENODATA) {
                src_in = (struct sockaddr *)&req->src_addr;
                dst_in = (struct sockaddr *)&req->dst_addr;
                req->status = addr_resolve(src_in, dst_in, req->addr,
                                           true, req->seq);
                if (req->status && time_after_eq(jiffies, req->timeout)) {
                        req->status = -ETIMEDOUT;
                } else if (req->status == -ENODATA) {
                        /* requeue the work for retrying again */
                        set_timeout(&req->work, req->timeout);
                        mutex_unlock(&lock);
                        return;
                }
        }
        list_del(&req->list);
        mutex_unlock(&lock);

        req->callback(req->status, (struct sockaddr *)&req->src_addr,
                req->addr, req->context);
        put_client(req->client);
        kfree(req);
}

static void process_req(struct work_struct *work)
{
        struct addr_req *req, *temp_req;
        struct sockaddr *src_in, *dst_in;
        struct list_head done_list;

        INIT_LIST_HEAD(&done_list);

        mutex_lock(&lock);
        list_for_each_entry_safe(req, temp_req, &req_list, list) {
                if (req->status == -ENODATA) {
                        src_in = (struct sockaddr *) &req->src_addr;
                        dst_in = (struct sockaddr *) &req->dst_addr;
                        req->status = addr_resolve(src_in, dst_in, req->addr,
                                                   true, req->seq);
                        if (req->status && time_after_eq(jiffies, req->timeout))
                                req->status = -ETIMEDOUT;
                        else if (req->status == -ENODATA) {
                                set_timeout(&req->work, req->timeout);
                                continue;
                        }
                }
                list_move_tail(&req->list, &done_list);
        }

        mutex_unlock(&lock);

        list_for_each_entry_safe(req, temp_req, &done_list, list) {
                list_del(&req->list);
                /* It is safe to cancel other work items from this work item
                 * because at a time there can be only one work item running
                 * with this single threaded work queue.
                 */
                cancel_delayed_work(&req->work);
                req->callback(req->status, (struct sockaddr *) &req->src_addr,
                        req->addr, req->context);
                put_client(req->client);
                kfree(req);
        }
}

int rdma_resolve_ip(struct rdma_addr_client *client,
                    struct sockaddr *src_addr, struct sockaddr *dst_addr,
                    struct rdma_dev_addr *addr, int timeout_ms,
                    void (*callback)(int status, struct sockaddr *src_addr,
                                     struct rdma_dev_addr *addr, void *context),
                    void *context)
{
        struct sockaddr *src_in, *dst_in;
        struct addr_req *req;
        int ret = 0;

        req = kzalloc(sizeof *req, GFP_KERNEL);
        if (!req)
                return -ENOMEM;

        src_in = (struct sockaddr *) &req->src_addr;
        dst_in = (struct sockaddr *) &req->dst_addr;

        if (src_addr) {
                if (src_addr->sa_family != dst_addr->sa_family) {
                        ret = -EINVAL;
                        goto err;
                }

                memcpy(src_in, src_addr, rdma_addr_size(src_addr));
        } else {
                src_in->sa_family = dst_addr->sa_family;
        }

        memcpy(dst_in, dst_addr, rdma_addr_size(dst_addr));
        req->addr = addr;
        req->callback = callback;
        req->context = context;
        req->client = client;
        atomic_inc(&client->refcount);
        INIT_DELAYED_WORK(&req->work, process_one_req);
        req->seq = (u32)atomic_inc_return(&ib_nl_addr_request_seq);

        req->status = addr_resolve(src_in, dst_in, addr, true, req->seq);
        switch (req->status) {
        case 0:
                req->timeout = jiffies;
                queue_req(req);
                break;
        case -ENODATA:
                req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
                queue_req(req);
                break;
        default:
                ret = req->status;
                atomic_dec(&client->refcount);
                goto err;
        }
        return ret;
err:
        kfree(req);
        return ret;
}
EXPORT_SYMBOL(rdma_resolve_ip);

int rdma_resolve_ip_route(struct sockaddr *src_addr,
                          const struct sockaddr *dst_addr,
                          struct rdma_dev_addr *addr)
{
        struct sockaddr_storage ssrc_addr = {};
        struct sockaddr *src_in = (struct sockaddr *)&ssrc_addr;

        if (src_addr) {
                if (src_addr->sa_family != dst_addr->sa_family)
                        return -EINVAL;

                memcpy(src_in, src_addr, rdma_addr_size(src_addr));
        } else {
                src_in->sa_family = dst_addr->sa_family;
        }

        return addr_resolve(src_in, dst_addr, addr, false, 0);
}
EXPORT_SYMBOL(rdma_resolve_ip_route);

void rdma_addr_cancel(struct rdma_dev_addr *addr)
{
        struct addr_req *req, *temp_req;

        mutex_lock(&lock);
        list_for_each_entry_safe(req, temp_req, &req_list, list) {
                if (req->addr == addr) {
                        req->status = -ECANCELED;
                        req->timeout = jiffies;
                        list_move(&req->list, &req_list);
                        set_timeout(&req->work, req->timeout);
                        break;
                }
        }
        mutex_unlock(&lock);
}
EXPORT_SYMBOL(rdma_addr_cancel);

struct resolve_cb_context {
        struct rdma_dev_addr *addr;
        struct completion comp;
        int status;
};

static void resolve_cb(int status, struct sockaddr *src_addr,
             struct rdma_dev_addr *addr, void *context)
{
        if (!status)
                memcpy(((struct resolve_cb_context *)context)->addr,
                       addr, sizeof(struct rdma_dev_addr));
        ((struct resolve_cb_context *)context)->status = status;
        complete(&((struct resolve_cb_context *)context)->comp);
}

int rdma_addr_find_l2_eth_by_grh(const union ib_gid *sgid,
                                 const union ib_gid *dgid,
                                 u8 *dmac, u16 *vlan_id, int *if_index,
                                 int *hoplimit)
{
        int ret = 0;
        struct rdma_dev_addr dev_addr;
        struct resolve_cb_context ctx;
        struct net_device *dev;

        union {
                struct sockaddr     _sockaddr;
                struct sockaddr_in  _sockaddr_in;
                struct sockaddr_in6 _sockaddr_in6;
        } sgid_addr, dgid_addr;


        rdma_gid2ip(&sgid_addr._sockaddr, sgid);
        rdma_gid2ip(&dgid_addr._sockaddr, dgid);

        memset(&dev_addr, 0, sizeof(dev_addr));
        if (if_index)
                dev_addr.bound_dev_if = *if_index;
        dev_addr.net = &init_net;

        ctx.addr = &dev_addr;
        init_completion(&ctx.comp);
        ret = rdma_resolve_ip(&self, &sgid_addr._sockaddr, &dgid_addr._sockaddr,
                        &dev_addr, 1000, resolve_cb, &ctx);
        if (ret)
                return ret;

        wait_for_completion(&ctx.comp);

        ret = ctx.status;
        if (ret)
                return ret;

        memcpy(dmac, dev_addr.dst_dev_addr, ETH_ALEN);
        dev = dev_get_by_index(&init_net, dev_addr.bound_dev_if);
        if (!dev)
                return -ENODEV;
        if (if_index)
                *if_index = dev_addr.bound_dev_if;
        if (vlan_id)
                *vlan_id = rdma_vlan_dev_vlan_id(dev);
        if (hoplimit)
                *hoplimit = dev_addr.hoplimit;
        dev_put(dev);
        return ret;
}
EXPORT_SYMBOL(rdma_addr_find_l2_eth_by_grh);

int rdma_addr_find_smac_by_sgid(union ib_gid *sgid, u8 *smac, u16 *vlan_id)
{
        int ret = 0;
        struct rdma_dev_addr dev_addr;
        union {
                struct sockaddr     _sockaddr;
                struct sockaddr_in  _sockaddr_in;
                struct sockaddr_in6 _sockaddr_in6;
        } gid_addr;

        rdma_gid2ip(&gid_addr._sockaddr, sgid);

        memset(&dev_addr, 0, sizeof(dev_addr));
        dev_addr.net = &init_net;
        ret = rdma_translate_ip(&gid_addr._sockaddr, &dev_addr, vlan_id);
        if (ret)
                return ret;

        memcpy(smac, dev_addr.src_dev_addr, ETH_ALEN);
        return ret;
}
EXPORT_SYMBOL(rdma_addr_find_smac_by_sgid);

static int netevent_callback(struct notifier_block *self, unsigned long event,
        void *ctx)
{
        if (event == NETEVENT_NEIGH_UPDATE) {
                struct neighbour *neigh = ctx;

                if (neigh->nud_state & NUD_VALID)
                        set_timeout(&work, jiffies);
        }
        return 0;
}

static struct notifier_block nb = {
        .notifier_call = netevent_callback
};

int addr_init(void)
{
        addr_wq = alloc_ordered_workqueue("ib_addr", WQ_MEM_RECLAIM);
        if (!addr_wq)
                return -ENOMEM;

        register_netevent_notifier(&nb);
        rdma_addr_register_client(&self);

        return 0;
}

void addr_cleanup(void)
{
        rdma_addr_unregister_client(&self);
        unregister_netevent_notifier(&nb);
        destroy_workqueue(addr_wq);
}