Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 785 insertions, 0 deletions

diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
new file mode 100644
index 000000000..30385ba7c
--- /dev/null
+++ b/drivers/infiniband/core/addr.c
@@ -0,0 +1,785 @@
+/*
+ * 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 0;
+}
+
+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(const 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);
+	if (!n)
+		return -ENODATA;
+
+	if (!(n->nud_state & NUD_VALID)) {
+		neigh_event_send(n, NULL);
+		ret = -ENODATA;
+	} else {
+		rdma_copy_addr(dev_addr, dst->dev, n->ha);
+	}
+
+	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;
+
+	memset(&fl6, 0, sizeof fl6);
+	fl6.daddr = dst_in->sin6_addr;
+	fl6.saddr = src_in->sin6_addr;
+	fl6.flowi6_oif = addr->bound_dev_if;
+
+	dst = ipv6_stub->ipv6_dst_lookup_flow(addr->net, NULL, &fl6, NULL);
+	if (IS_ERR(dst))
+		return PTR_ERR(dst);
+
+	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);
+	/*
+	 * 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);
+	if (!list_empty(&req->list)) {
+		list_del_init(&req->list);
+		kfree(req);
+	}
+	spin_unlock_bh(&lock);
+}
+
+int rdma_resolve_ip(struct sockaddr *src_addr, const 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_in  _sockaddr_in;
+		struct sockaddr_in6 _sockaddr_in6;
+	} sgid_addr, dgid_addr;
+	int ret;
+
+	rdma_gid2ip((struct sockaddr *)&sgid_addr, sgid);
+	rdma_gid2ip((struct sockaddr *)&dgid_addr, 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((struct sockaddr *)&sgid_addr,
+			      (struct sockaddr *)&dgid_addr, &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));
+}