drivers/infiniband/core/addr.c - third_party/linux - Git at Google

 /*
  * 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;
 	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 DEFINE_SPINLOCK(lock);
 static LIST_HEAD(req_list);
 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));
 	}

 	spin_lock_bh(&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;
 	}
 	spin_unlock_bh(&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 nlmsghdr *nlh,
 			     struct netlink_ext_ack *extack)
 {
 	if ((nlh->nlmsg_flags & NLM_F_REQUEST) ||
 	    !(NETLINK_CB(skb).sk))
 		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);
 	rdma_nl_multicast(skb, 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);

 int rdma_addr_size_in6(struct sockaddr_in6 *addr)
 {
 	int ret = rdma_addr_size((struct sockaddr *) addr);

 	return ret <= sizeof(*addr) ? ret : 0;
 }
 EXPORT_SYMBOL(rdma_addr_size_in6);

 int rdma_addr_size_kss(struct __kernel_sockaddr_storage *addr)
 {
 	int ret = rdma_addr_size((struct sockaddr *) addr);

 	return ret <= sizeof(*addr) ? ret : 0;
 }
 EXPORT_SYMBOL(rdma_addr_size_kss);

 void rdma_copy_addr(struct rdma_dev_addr *dev_addr,
 		    const 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;
 }
 EXPORT_SYMBOL(rdma_copy_addr);

 int rdma_translate_ip(const struct sockaddr *addr,
 		      struct rdma_dev_addr *dev_addr)
 {
 	struct net_device *dev;

 	if (dev_addr->bound_dev_if) {
 		dev = dev_get_by_index(dev_addr->net, dev_addr->bound_dev_if);
 		if (!dev)
 			return -ENODEV;
 		rdma_copy_addr(dev_addr, dev, NULL);
 		dev_put(dev);
 		return 0;
 	}

 	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 -EADDRNOTAVAIL;

 		rdma_copy_addr(dev_addr, dev, NULL);
 		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)) {
 				rdma_copy_addr(dev_addr, dev, NULL);
 				break;
 			}
 		}
 		rcu_read_unlock();
 		break;
 #endif
 	}
 	return 0;
 }
 EXPORT_SYMBOL(rdma_translate_ip);

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

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

 	mod_delayed_work(addr_wq, &req->work, delay);
 }

 static void queue_req(struct addr_req *req)
 {
 	spin_lock_bh(&lock);
 	list_add_tail(&req->list, &req_list);
 	set_timeout(req, req->timeout);
 	spin_unlock_bh(&lock);
 }

 static int ib_nl_fetch_ha(const struct dst_entry *dst,
 			  struct rdma_dev_addr *dev_addr,
 			  const void *daddr, u32 seq, u16 family)
 {
 	if (rdma_nl_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(const struct dst_entry *dst,
 			struct rdma_dev_addr *dev_addr,
 			const void *daddr)
 {
 	struct neighbour *n;
 	int ret = 0;

 	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 {
 		rdma_copy_addr(dev_addr, dst->dev, n->ha);
 	}
 	rcu_read_unlock();

 	if (n)
 		neigh_release(n);

 	return ret;
 }

 static bool has_gateway(const 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(const 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(const 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);
 		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);

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

 	return 0;
 }

 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) {
 		if (ndev->flags & IFF_LOOPBACK)
 			ret = rdma_translate_ip(dst_in, addr);
 		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;

 	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 */
 			spin_lock_bh(&lock);
 			if (!list_empty(&req->list))
 				set_timeout(req, req->timeout);
 			spin_unlock_bh(&lock);
 			return;
 		}
 	}

 	req->callback(req->status, (struct sockaddr *)&req->src_addr,
 		req->addr, req->context);
 	req->callback = NULL;

 	spin_lock_bh(&lock);
 	if (!list_empty(&req->list)) {
 		/*
 		 * Although the work will normally have been canceled by the
 		 * workqueue, it can still be requeued as long as it is on the
 		 * req_list.
 		 */
 		cancel_delayed_work(&req->work);
 		list_del_init(&req->list);
 		kfree(req);
 	}
 	spin_unlock_bh(&lock);
 }

 int rdma_resolve_ip(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;
 	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;
 		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);
 }

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

 	spin_lock_bh(&lock);
 	list_for_each_entry_safe(req, temp_req, &req_list, list) {
 		if (req->addr == addr) {
 			/*
 			 * Removing from the list means we take ownership of
 			 * the req
 			 */
 			list_del_init(&req->list);
 			found = req;
 			break;
 		}
 	}
 	spin_unlock_bh(&lock);

 	if (!found)
 		return;

 	/*
 	 * sync canceling the work after removing it from the req_list
 	 * guarentees no work is running and none will be started.
 	 */
 	cancel_delayed_work_sync(&found->work);

 	if (found->callback)
 		found->callback(-ECANCELED, (struct sockaddr *)&found->src_addr,
 			      found->addr, found->context);

 	kfree(found);
 }
 EXPORT_SYMBOL(rdma_addr_cancel);

 struct resolve_cb_context {
 	struct completion comp;
 	int status;
 };

 static void resolve_cb(int status, struct sockaddr *src_addr,
 	     struct rdma_dev_addr *addr, void *context)
 {
 	((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, const struct net_device *ndev,
 				 int *hoplimit)
 {
 	struct rdma_dev_addr dev_addr;
 	struct resolve_cb_context ctx;
 	union {
 		struct sockaddr     _sockaddr;
 		struct sockaddr_in  _sockaddr_in;
 		struct sockaddr_in6 _sockaddr_in6;
 	} sgid_addr, dgid_addr;
 	int ret;

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

 	memset(&dev_addr, 0, sizeof(dev_addr));
 	dev_addr.bound_dev_if = ndev->ifindex;
 	dev_addr.net = &init_net;

 	init_completion(&ctx.comp);
 	ret = rdma_resolve_ip(&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);
 	*hoplimit = dev_addr.hoplimit;
 	return 0;
 }

 static int netevent_callback(struct notifier_block *self, unsigned long event,
 	void *ctx)
 {
 	struct addr_req *req;

 	if (event == NETEVENT_NEIGH_UPDATE) {
 		struct neighbour *neigh = ctx;

 		if (neigh->nud_state & NUD_VALID) {
 			spin_lock_bh(&lock);
 			list_for_each_entry(req, &req_list, list)
 				set_timeout(req, jiffies);
 			spin_unlock_bh(&lock);
 		}
 	}
 	return 0;
 }

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

 int addr_init(void)
 {
 	addr_wq = alloc_ordered_workqueue("ib_addr", 0);
 	if (!addr_wq)
 		return -ENOMEM;

 	register_netevent_notifier(&nb);

 	return 0;
 }

 void addr_cleanup(void)
 {
 	unregister_netevent_notifier(&nb);
 	destroy_workqueue(addr_wq);
 	WARN_ON(!list_empty(&req_list));
 }
	/*
	* 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;
	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 DEFINE_SPINLOCK(lock);
	static LIST_HEAD(req_list);
	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));
	}

	spin_lock_bh(&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;
	}
	spin_unlock_bh(&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 nlmsghdr *nlh,
	struct netlink_ext_ack *extack)
	{
	if ((nlh->nlmsg_flags & NLM_F_REQUEST) \|\|
	!(NETLINK_CB(skb).sk))
	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);
	rdma_nl_multicast(skb, 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);

	int rdma_addr_size_in6(struct sockaddr_in6 *addr)
	{
	int ret = rdma_addr_size((struct sockaddr *) addr);

	return ret <= sizeof(*addr) ? ret : 0;
	}
	EXPORT_SYMBOL(rdma_addr_size_in6);

	int rdma_addr_size_kss(struct __kernel_sockaddr_storage *addr)
	{
	int ret = rdma_addr_size((struct sockaddr *) addr);

	return ret <= sizeof(*addr) ? ret : 0;
	}
	EXPORT_SYMBOL(rdma_addr_size_kss);

	void rdma_copy_addr(struct rdma_dev_addr *dev_addr,
	const 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;
	}
	EXPORT_SYMBOL(rdma_copy_addr);

	int rdma_translate_ip(const struct sockaddr *addr,
	struct rdma_dev_addr *dev_addr)
	{
	struct net_device *dev;

	if (dev_addr->bound_dev_if) {
	dev = dev_get_by_index(dev_addr->net, dev_addr->bound_dev_if);
	if (!dev)
	return -ENODEV;
	rdma_copy_addr(dev_addr, dev, NULL);
	dev_put(dev);
	return 0;
	}

	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 -EADDRNOTAVAIL;

	rdma_copy_addr(dev_addr, dev, NULL);
	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)) {
	rdma_copy_addr(dev_addr, dev, NULL);
	break;
	}
	}
	rcu_read_unlock();
	break;
	#endif
	}
	return 0;
	}
	EXPORT_SYMBOL(rdma_translate_ip);

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

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

	mod_delayed_work(addr_wq, &req->work, delay);
	}

	static void queue_req(struct addr_req *req)
	{
	spin_lock_bh(&lock);
	list_add_tail(&req->list, &req_list);
	set_timeout(req, req->timeout);
	spin_unlock_bh(&lock);
	}

	static int ib_nl_fetch_ha(const struct dst_entry *dst,
	struct rdma_dev_addr *dev_addr,
	const void *daddr, u32 seq, u16 family)
	{
	if (rdma_nl_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(const struct dst_entry *dst,
	struct rdma_dev_addr *dev_addr,
	const void *daddr)
	{
	struct neighbour *n;
	int ret = 0;

	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 {
	rdma_copy_addr(dev_addr, dst->dev, n->ha);
	}
	rcu_read_unlock();

	if (n)
	neigh_release(n);

	return ret;
	}

	static bool has_gateway(const 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(const 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(const 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);
	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);

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

	return 0;
	}

	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) {
	if (ndev->flags & IFF_LOOPBACK)
	ret = rdma_translate_ip(dst_in, addr);
	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;

	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 */
	spin_lock_bh(&lock);
	if (!list_empty(&req->list))
	set_timeout(req, req->timeout);
	spin_unlock_bh(&lock);
	return;
	}
	}

	req->callback(req->status, (struct sockaddr *)&req->src_addr,
	req->addr, req->context);
	req->callback = NULL;

	spin_lock_bh(&lock);
	if (!list_empty(&req->list)) {
	/*
	* Although the work will normally have been canceled by the
	* workqueue, it can still be requeued as long as it is on the
	* req_list.
	*/
	cancel_delayed_work(&req->work);
	list_del_init(&req->list);
	kfree(req);
	}
	spin_unlock_bh(&lock);
	}

	int rdma_resolve_ip(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;
	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;
	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);
	}

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

	spin_lock_bh(&lock);
	list_for_each_entry_safe(req, temp_req, &req_list, list) {
	if (req->addr == addr) {
	/*
	* Removing from the list means we take ownership of
	* the req
	*/
	list_del_init(&req->list);
	found = req;
	break;
	}
	}
	spin_unlock_bh(&lock);

	if (!found)
	return;

	/*
	* sync canceling the work after removing it from the req_list
	* guarentees no work is running and none will be started.
	*/
	cancel_delayed_work_sync(&found->work);

	if (found->callback)
	found->callback(-ECANCELED, (struct sockaddr *)&found->src_addr,
	found->addr, found->context);

	kfree(found);
	}
	EXPORT_SYMBOL(rdma_addr_cancel);

	struct resolve_cb_context {
	struct completion comp;
	int status;
	};

	static void resolve_cb(int status, struct sockaddr *src_addr,
	struct rdma_dev_addr addr, void context)
	{
	((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, const struct net_device ndev,
	int *hoplimit)
	{
	struct rdma_dev_addr dev_addr;
	struct resolve_cb_context ctx;
	union {
	struct sockaddr _sockaddr;
	struct sockaddr_in _sockaddr_in;
	struct sockaddr_in6 _sockaddr_in6;
	} sgid_addr, dgid_addr;
	int ret;

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

	memset(&dev_addr, 0, sizeof(dev_addr));
	dev_addr.bound_dev_if = ndev->ifindex;
	dev_addr.net = &init_net;

	init_completion(&ctx.comp);
	ret = rdma_resolve_ip(&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);
	*hoplimit = dev_addr.hoplimit;
	return 0;
	}

	static int netevent_callback(struct notifier_block *self, unsigned long event,
	void *ctx)
	{
	struct addr_req *req;

	if (event == NETEVENT_NEIGH_UPDATE) {
	struct neighbour *neigh = ctx;

	if (neigh->nud_state & NUD_VALID) {
	spin_lock_bh(&lock);
	list_for_each_entry(req, &req_list, list)
	set_timeout(req, jiffies);
	spin_unlock_bh(&lock);
	}
	}
	return 0;
	}

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

	int addr_init(void)
	{
	addr_wq = alloc_ordered_workqueue("ib_addr", 0);
	if (!addr_wq)
	return -ENOMEM;

	register_netevent_notifier(&nb);

	return 0;
	}

	void addr_cleanup(void)
	{
	unregister_netevent_notifier(&nb);
	destroy_workqueue(addr_wq);
	WARN_ON(!list_empty(&req_list));
	}