/*-
 * SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0
 *
 * Copyright (c) 2005 Voltaire Inc.  All rights reserved.
 * Copyright (c) 2002-2005, Network Appliance, Inc. All rights reserved.
 * Copyright (c) 1999-2019, 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 <sys/cdefs.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/module.h>
#include <net/if_llatbl.h>
#include <net/route.h>
#include <net/route/nhop.h>
#include <net/netevent.h>
#include <rdma/ib_addr.h>
#include <rdma/ib_cache.h>
#include <rdma/ib_sa.h>
#include <rdma/ib.h>

#include <netinet/in_fib.h>
#include <netinet/if_ether.h>
#include <netinet/ip_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/in6_fib.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;
	bool resolve_by_gid_attr;	/* Consider gid attr in resolve phase */
	int status;
};

static DEFINE_SPINLOCK(lock);
static LIST_HEAD(req_list);
static struct workqueue_struct *addr_wq;

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

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

static inline void
rdma_copy_addr_sub(u8 *dst, const u8 *src, unsigned min, unsigned max)
{
	if (min > max)
		min = max;
	memcpy(dst, src, min);
	memset(dst + min, 0, max - min);
}

/**
 * rdma_copy_src_l2_addr - Copy netdevice source addresses
 * @dev_addr:	Destination address pointer where to copy the addresses
 * @dev:	Netdevice whose source addresses to copy
 *
 * rdma_copy_src_l2_addr() copies source addresses from the specified netdevice.
 * This includes unicast address, broadcast address, device type and
 * interface index.
 */
void rdma_copy_src_l2_addr(struct rdma_dev_addr *dev_addr,
			   const if_t dev)
{
	int dev_type = if_gettype(dev);

	/* check for loopback device */
	if (if_getflags(dev) & IFF_LOOPBACK) {
		dev_addr->dev_type = ARPHRD_ETHER;
		memset(dev_addr->src_dev_addr, 0, MAX_ADDR_LEN);
		memset(dev_addr->broadcast, 0, MAX_ADDR_LEN);
		memset(dev_addr->dst_dev_addr, 0, MAX_ADDR_LEN);
		dev_addr->bound_dev_if = if_getindex(dev);
		return;
	} else if (dev_type == IFT_INFINIBAND)
		dev_addr->dev_type = ARPHRD_INFINIBAND;
	else if (dev_type == IFT_ETHER || dev_type == IFT_L2VLAN)
		dev_addr->dev_type = ARPHRD_ETHER;
	else
		dev_addr->dev_type = 0;
	rdma_copy_addr_sub(dev_addr->src_dev_addr, if_getlladdr(dev),
			   if_getaddrlen(dev), MAX_ADDR_LEN);
	rdma_copy_addr_sub(dev_addr->broadcast, if_getbroadcastaddr(dev),
			   if_getaddrlen(dev), MAX_ADDR_LEN);
	dev_addr->bound_dev_if = if_getindex(dev);
}
EXPORT_SYMBOL(rdma_copy_src_l2_addr);

static if_t
rdma_find_ndev_for_src_ip_rcu(struct vnet *net, const struct sockaddr *src_in)
{
	if_t dev = NULL;
	int ret = -EADDRNOTAVAIL;

	switch (src_in->sa_family) {
#ifdef INET
	case AF_INET:
		dev = ip_ifp_find(net,
			((const struct sockaddr_in *)src_in)->sin_addr.s_addr);
		if (dev)
			ret = 0;
		break;
#endif
#ifdef INET6
	case AF_INET6:
		dev = ip6_ifp_find(net,
			((const struct sockaddr_in6 *)src_in)->sin6_addr, 0);
		if (dev)
			ret = 0;
		break;
#endif
	}
	return ret ? ERR_PTR(ret) : dev;
}

int rdma_translate_ip(const struct sockaddr *addr,
		      struct rdma_dev_addr *dev_addr)
{
	if_t dev;
	int ret = 0;

	if (dev_addr->bound_dev_if) {
		dev = dev_get_by_index(dev_addr->net, dev_addr->bound_dev_if);
		if (!dev)
			return -ENODEV;
	} else {
		rcu_read_lock();
		dev = rdma_find_ndev_for_src_ip_rcu(dev_addr->net, addr);
		rcu_read_unlock();
		if (IS_ERR(dev))
			return PTR_ERR(dev);
	}

	/* disallow connections through 127.0.0.1 itself */
	if (if_getflags(dev) & IFF_LOOPBACK)
		ret = -EINVAL;
	else
		rdma_copy_src_l2_addr(dev_addr, dev);
	dev_put(dev);
	return ret;
}
EXPORT_SYMBOL(rdma_translate_ip);

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

	delay = time - jiffies;
	if (delay <= 0)
		delay = 1;
	else if (delay > hz)
		delay = hz;

	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);
}

#if defined(INET) || defined(INET6)
static int addr_resolve_multi(u8 *edst, if_t ifp, struct sockaddr *dst_in)
{
	struct sockaddr *llsa;
	struct sockaddr_dl sdl;
	int error;

	sdl.sdl_len = sizeof(sdl);
	llsa = (struct sockaddr *)&sdl;

	error = if_resolvemulti(ifp, &llsa, dst_in);
	if (error == 0) {
		rdma_copy_addr_sub(edst, LLADDR((struct sockaddr_dl *)llsa),
		    if_getaddrlen(ifp), MAX_ADDR_LEN);
	}
	return (error);
}
#endif

#ifdef INET
static int addr4_resolve(struct sockaddr *src_sock,
			 const struct sockaddr *dst_sock,
			 struct rdma_dev_addr *addr,
			 u8 *edst,
			 if_t *ifpp)
{
	struct sockaddr_in *src_in = (struct sockaddr_in *)src_sock;
	const struct sockaddr_in *dst_in =
			(const struct sockaddr_in *)dst_sock;
	enum {
		ADDR_VALID = 0,
		ADDR_SRC_ANY = 1,
		ADDR_DST_ANY = 2,
	};
	struct sockaddr_in dst_tmp = *dst_in;
	in_port_t src_port;
	struct sockaddr *saddr = NULL;
	struct nhop_object *nh;
	if_t ifp;
	int error;
	int type;

	NET_EPOCH_ASSERT();

	/* set VNET, if any */
	CURVNET_SET(addr->net);

	/* set default TTL limit */
	addr->hoplimit = V_ip_defttl;

	type = ADDR_VALID;
	if (src_in->sin_addr.s_addr == INADDR_ANY)
		type |= ADDR_SRC_ANY;
	if (dst_tmp.sin_addr.s_addr == INADDR_ANY)
		type |= ADDR_DST_ANY;

	/*
	 * Make sure the socket address length field is set.
	 */
	dst_tmp.sin_len = sizeof(dst_tmp);

	/* Step 1 - lookup destination route if any */
	switch (type) {
	case ADDR_VALID:
	case ADDR_SRC_ANY:
		/* regular destination route lookup */
		nh = fib4_lookup(RT_DEFAULT_FIB, dst_tmp.sin_addr,0,NHR_NONE,0);
		if (nh == NULL) {
			error = EHOSTUNREACH;
			goto done;
		}
		break;
	default:
		error = ENETUNREACH;
		goto done;
	}

	/* Step 2 - find outgoing network interface */
	switch (type) {
	case ADDR_VALID:
		/* get source interface */
		if (addr->bound_dev_if != 0) {
			ifp = dev_get_by_index(addr->net, addr->bound_dev_if);
		} else {
			ifp = ip_ifp_find(addr->net, src_in->sin_addr.s_addr);
		}

		/* check source interface */
		if (ifp == NULL) {
			error = ENETUNREACH;
			goto done;
		} else if (if_getflags(ifp) & IFF_LOOPBACK) {
			/*
			 * Source address cannot be a loopback device.
			 */
			error = EHOSTUNREACH;
			goto error_put_ifp;
		} else if (if_getflags(nh->nh_ifp) & IFF_LOOPBACK) {
			if (memcmp(&src_in->sin_addr, &dst_in->sin_addr,
			    sizeof(src_in->sin_addr))) {
				/*
				 * Destination is loopback, but source
				 * and destination address is not the
				 * same.
				 */
				error = EHOSTUNREACH;
				goto error_put_ifp;
			}
			/* get destination network interface from route */
			dev_put(ifp);
			ifp = nh->nh_ifp;
			dev_hold(ifp);
		} else if (ifp != nh->nh_ifp) {
			/*
			 * Source and destination interfaces are
			 * different.
			 */
			error = ENETUNREACH;
			goto error_put_ifp;
		}
		break;
	case ADDR_SRC_ANY:
		/* check for loopback device */
		if (if_getflags(nh->nh_ifp) & IFF_LOOPBACK)
			saddr = (struct sockaddr *)&dst_tmp;
		else
			saddr = nh->nh_ifa->ifa_addr;

		/* get destination network interface from route */
		ifp = nh->nh_ifp;
		dev_hold(ifp);
		break;
	default:
		break;
	}

	/*
	 * Step 3 - resolve destination MAC address
	 */
	if (dst_tmp.sin_addr.s_addr == INADDR_BROADCAST) {
		rdma_copy_addr_sub(edst, if_getbroadcastaddr(ifp),
		    if_getaddrlen(ifp), MAX_ADDR_LEN);
		error = 0;
	} else if (IN_MULTICAST(ntohl(dst_tmp.sin_addr.s_addr))) {
		bool is_gw = (nh->nh_flags & NHF_GATEWAY) != 0;
		error = addr_resolve_multi(edst, ifp, (struct sockaddr *)&dst_tmp);
		if (error != 0)
			goto error_put_ifp;
		else if (is_gw)
			addr->network = RDMA_NETWORK_IPV4;
	} else if (if_getflags(ifp) & IFF_LOOPBACK) {
		memset(edst, 0, MAX_ADDR_LEN);
		error = 0;
	} else {
		bool is_gw = (nh->nh_flags & NHF_GATEWAY) != 0;
		memset(edst, 0, MAX_ADDR_LEN);
#ifdef INET6
		if (is_gw && nh->gw_sa.sa_family == AF_INET6)
			error = nd6_resolve(ifp, LLE_SF(AF_INET, is_gw), NULL,
			    &nh->gw_sa, edst, NULL, NULL);
		else
#endif
			error = arpresolve(ifp, is_gw, NULL, is_gw ?
			    &nh->gw_sa : (const struct sockaddr *)&dst_tmp,
			    edst, NULL, NULL);

		if (error != 0)
			goto error_put_ifp;
		else if (is_gw)
			addr->network = RDMA_NETWORK_IPV4;
	}

	/*
	 * Step 4 - update source address, if any
	 */
	if (saddr != NULL) {
		src_port = src_in->sin_port;
		memcpy(src_in, saddr, rdma_addr_size(saddr));
		src_in->sin_port = src_port;	/* preserve port number */
	}

	*ifpp = ifp;

	goto done;

error_put_ifp:
	dev_put(ifp);
done:
	CURVNET_RESTORE();

	if (error == EWOULDBLOCK || error == EAGAIN)
		error = ENODATA;
	return (-error);
}
#else
static int addr4_resolve(struct sockaddr *src_sock,
			 const struct sockaddr *dst_sock,
			 struct rdma_dev_addr *addr,
			 u8 *edst,
			 if_t *ifpp)
{
	return -EADDRNOTAVAIL;
}
#endif

#ifdef INET6
static int addr6_resolve(struct sockaddr *src_sock,
			 const struct sockaddr *dst_sock,
			 struct rdma_dev_addr *addr,
			 u8 *edst,
			 if_t *ifpp)
{
	struct sockaddr_in6 *src_in = (struct sockaddr_in6 *)src_sock;
	const struct sockaddr_in6 *dst_in =
				(const struct sockaddr_in6 *)dst_sock;
	enum {
		ADDR_VALID = 0,
		ADDR_SRC_ANY = 1,
		ADDR_DST_ANY = 2,
	};
	struct sockaddr_in6 dst_tmp = *dst_in;
	in_port_t src_port;
	struct sockaddr *saddr = NULL;
	struct nhop_object *nh;
	if_t ifp;
	int error;
	int type;

	NET_EPOCH_ASSERT();

	/* set VNET, if any */
	CURVNET_SET(addr->net);

	/* set default TTL limit */
	addr->hoplimit = V_ip_defttl;

	type = ADDR_VALID;
	if (ipv6_addr_any(&src_in->sin6_addr))
		type |= ADDR_SRC_ANY;
	if (ipv6_addr_any(&dst_tmp.sin6_addr))
		type |= ADDR_DST_ANY;

	/*
	 * Make sure the socket address length field is set.
	 */
	dst_tmp.sin6_len = sizeof(dst_tmp);

	/*
	 * Make sure the scope ID gets embedded, else nd6_resolve() will
	 * not find the record.
	 */
	dst_tmp.sin6_scope_id = addr->bound_dev_if;
	sa6_embedscope(&dst_tmp, 0);

	/* Step 1 - lookup destination route if any */
	switch (type) {
	case ADDR_VALID:
		/* sanity check for IPv4 addresses */
		if (ipv6_addr_v4mapped(&src_in->sin6_addr) !=
		    ipv6_addr_v4mapped(&dst_tmp.sin6_addr)) {
			error = EAFNOSUPPORT;
			goto done;
		}
		/* FALLTHROUGH */
	case ADDR_SRC_ANY:
		/* regular destination route lookup */
		nh = fib6_lookup(RT_DEFAULT_FIB, &dst_in->sin6_addr,
		    addr->bound_dev_if, NHR_NONE, 0);
		if (nh == NULL) {
			error = EHOSTUNREACH;
			goto done;
		}
		break;
	default:
		error = ENETUNREACH;
		goto done;
	}

	/* Step 2 - find outgoing network interface */
	switch (type) {
	case ADDR_VALID:
		/* get source interface */
		if (addr->bound_dev_if != 0) {
			ifp = dev_get_by_index(addr->net, addr->bound_dev_if);
		} else {
			ifp = ip6_ifp_find(addr->net, src_in->sin6_addr, 0);
		}

		/* check source interface */
		if (ifp == NULL) {
			error = ENETUNREACH;
			goto done;
		} else if (if_getflags(ifp) & IFF_LOOPBACK) {
			/*
			 * Source address cannot be a loopback device.
			 */
			error = EHOSTUNREACH;
			goto error_put_ifp;
		} else if (if_getflags(nh->nh_ifp) & IFF_LOOPBACK) {
			if (memcmp(&src_in->sin6_addr, &dst_in->sin6_addr,
			    sizeof(src_in->sin6_addr))) {
				/*
				 * Destination is loopback, but source
				 * and destination address is not the
				 * same.
				 */
				error = EHOSTUNREACH;
				goto error_put_ifp;
			}
			/* get destination network interface from route */
			dev_put(ifp);
			ifp = nh->nh_ifp;
			dev_hold(ifp);
		} else if (ifp != nh->nh_ifp) {
			/*
			 * Source and destination interfaces are
			 * different.
			 */
			error = ENETUNREACH;
			goto error_put_ifp;
		}
		break;
	case ADDR_SRC_ANY:
		/* check for loopback device */
		if (if_getflags(nh->nh_ifp) & IFF_LOOPBACK)
			saddr = (struct sockaddr *)&dst_tmp;
		else
			saddr = nh->nh_ifa->ifa_addr;

		/* get destination network interface from route */
		ifp = nh->nh_ifp;
		dev_hold(ifp);
		break;
	default:
		break;
	}

	/*
	 * Step 3 - resolve destination MAC address
	 */
	if (IN6_IS_ADDR_MULTICAST(&dst_tmp.sin6_addr)) {
		bool is_gw = (nh->nh_flags & NHF_GATEWAY) != 0;
		error = addr_resolve_multi(edst, ifp,
		    (struct sockaddr *)&dst_tmp);
		if (error != 0)
			goto error_put_ifp;
		else if (is_gw)
			addr->network = RDMA_NETWORK_IPV6;
	} else if (if_getflags(nh->nh_ifp) & IFF_LOOPBACK) {
		memset(edst, 0, MAX_ADDR_LEN);
		error = 0;
	} else {
		bool is_gw = (nh->nh_flags & NHF_GATEWAY) != 0;
		memset(edst, 0, MAX_ADDR_LEN);
		error = nd6_resolve(ifp, LLE_SF(AF_INET6, is_gw), NULL,
		    is_gw ? &nh->gw_sa : (const struct sockaddr *)&dst_tmp,
		    edst, NULL, NULL);
		if (error != 0)
			goto error_put_ifp;
		else if (is_gw)
			addr->network = RDMA_NETWORK_IPV6;
	}

	/*
	 * Step 4 - update source address, if any
	 */
	if (saddr != NULL) {
		src_port = src_in->sin6_port;
		memcpy(src_in, saddr, rdma_addr_size(saddr));
		src_in->sin6_port = src_port;	/* preserve port number */
	}

	*ifpp = ifp;

	goto done;

error_put_ifp:
	dev_put(ifp);
done:
	CURVNET_RESTORE();

	if (error == EWOULDBLOCK || error == EAGAIN)
		error = ENODATA;
	return (-error);
}
#else
static int addr6_resolve(struct sockaddr *src_sock,
			 const struct sockaddr *dst_sock,
			 struct rdma_dev_addr *addr,
			 u8 *edst,
			 if_t *ifpp)
{
	return -EADDRNOTAVAIL;
}
#endif

static int addr_resolve_neigh(if_t dev,
			      const struct sockaddr *dst_in,
			      u8 *edst,
			      struct rdma_dev_addr *addr,
			      unsigned int ndev_flags)
{
	int ret = 0;

	if (ndev_flags & IFF_LOOPBACK) {
		/*
		 * Binding to a loopback device is not allowed. Make
		 * sure the destination device address is global by
		 * clearing the bound device interface:
		 */
		if (addr->bound_dev_if == if_getindex(dev))
			addr->bound_dev_if = 0;

		memcpy(addr->dst_dev_addr, addr->src_dev_addr, MAX_ADDR_LEN);
	} else {
		if (!(ndev_flags & IFF_NOARP)) {
			/* If the device doesn't do ARP internally */
			memcpy(addr->dst_dev_addr, edst, MAX_ADDR_LEN);
		}
        }

	return ret;
}

static int copy_src_l2_addr(struct rdma_dev_addr *dev_addr,
			    const struct sockaddr *dst_in,
			    if_t ndev)
{
	int ret = 0;

	if (if_getflags(ndev) & IFF_LOOPBACK)
		ret = rdma_translate_ip(dst_in, dev_addr);
	else
		rdma_copy_src_l2_addr(dev_addr, ndev);

	return ret;
}

static int rdma_set_src_addr_rcu(struct rdma_dev_addr *dev_addr,
				 unsigned int *ndev_flags,
				 const struct sockaddr *dst_in,
				 if_t ndev)
{
	*ndev_flags = if_getflags(ndev);
	/* A physical device must be the RDMA device to use */
	if (if_getflags(ndev) & IFF_LOOPBACK) {
		/*
		 * RDMA (IB/RoCE, iWarp) doesn't run on lo interface or
		 * loopback IP address. So if route is resolved to loopback
		 * interface, translate that to a real ndev based on non
		 * loopback IP address.
		 */
		ndev = rdma_find_ndev_for_src_ip_rcu(dev_net(ndev), dst_in);
		if (!ndev)
			return -ENODEV;
	}

	return copy_src_l2_addr(dev_addr, dst_in, ndev);
}

static int set_addr_netns_by_gid_rcu(struct rdma_dev_addr *addr)
{
	if_t ndev;

	ndev = rdma_read_gid_attr_ndev_rcu(addr->sgid_attr);
	if (IS_ERR(ndev))
		return PTR_ERR(ndev);

	/*
	 * Since we are holding the rcu, reading net and ifindex
	 * are safe without any additional reference; because
	 * change_net_namespace() in net/core/ib_dev.c does rcu sync
	 * after it changes the state to IFF_DOWN and before
	 * updating netdev fields {net, ifindex}.
	 */
	addr->net = dev_net(ndev);
	addr->bound_dev_if = if_getindex(ndev);
	return 0;
}

static void rdma_addr_set_net_defaults(struct rdma_dev_addr *addr)
{
	addr->net = &init_net;
	addr->bound_dev_if = 0;
}

static int addr_resolve(struct sockaddr *src_in,
			const struct sockaddr *dst_in,
			struct rdma_dev_addr *addr,
			bool resolve_by_gid_attr)
{
	struct epoch_tracker et;
	if_t ndev = NULL;
	u8 edst[MAX_ADDR_LEN];
	unsigned int ndev_flags = 0;
	int ret;

	if (dst_in->sa_family != src_in->sa_family)
		return -EINVAL;

	NET_EPOCH_ENTER(et);
	if (resolve_by_gid_attr) {
		if (!addr->sgid_attr) {
			NET_EPOCH_EXIT(et);
			pr_warn_ratelimited("%s: missing gid_attr\n", __func__);
			return -EINVAL;
		}
		/*
		 * If the request is for a specific gid attribute of the
		 * rdma_dev_addr, derive net from the netdevice of the
		 * GID attribute.
		 */
		ret = set_addr_netns_by_gid_rcu(addr);
		if (ret) {
			NET_EPOCH_EXIT(et);
			return ret;
		}
	}
	switch (src_in->sa_family) {
	case AF_INET:
		ret = addr4_resolve(src_in, dst_in, addr, edst, &ndev);
		break;
	case AF_INET6:
		ret = addr6_resolve(src_in, dst_in, addr, edst, &ndev);
		break;
	default:
		ret = -EADDRNOTAVAIL;
		break;
	}
	if (ret) {
		NET_EPOCH_EXIT(et);
		goto done;
	}
	ret = rdma_set_src_addr_rcu(addr, &ndev_flags, dst_in, ndev);
	NET_EPOCH_EXIT(et);

	/* store MAC addresses and check for loopback */
	if (!ret)
		ret = addr_resolve_neigh(ndev, dst_in, edst, addr, ndev_flags);

	/* set belonging VNET, if any */
	addr->net = dev_net(ndev);
	dev_put(ndev);
done:
	/*
	 * Clear the addr net to go back to its original state, only if it was
	 * derived from GID attribute in this context.
	 */
	if (resolve_by_gid_attr)
		rdma_addr_set_net_defaults(addr);
	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,
					   req->resolve_by_gid_attr);
		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, 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),
		    bool resolve_by_gid_attr,
		    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->resolve_by_gid_attr = resolve_by_gid_attr;
	INIT_DELAYED_WORK(&req->work, process_one_req);

	req->status = addr_resolve(src_in, dst_in, addr,
				   req->resolve_by_gid_attr);
	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 roce_resolve_route_from_path(struct sa_path_rec *rec,
				 const struct ib_gid_attr *attr)
{
	union rdma_sockaddr sgid, dgid;
	struct rdma_dev_addr dev_addr = {};
	int ret;

	if (rec->roce.route_resolved)
		return 0;

	rdma_gid2ip(&sgid._sockaddr, &rec->sgid);
	rdma_gid2ip(&dgid._sockaddr, &rec->dgid);

	if (sgid._sockaddr.sa_family != dgid._sockaddr.sa_family)
		return -EINVAL;

	if (!attr || !attr->ndev)
		return -EINVAL;

	dev_addr.net = &init_net;
	dev_addr.sgid_attr = attr;

	ret = addr_resolve(&sgid._sockaddr, &dgid._sockaddr,
			   &dev_addr, true);
	if (ret)
		return ret;

	if ((dev_addr.network == RDMA_NETWORK_IPV4 ||
	     dev_addr.network == RDMA_NETWORK_IPV6) &&
	    rec->rec_type != SA_PATH_REC_TYPE_ROCE_V2)
		return -EINVAL;

	rec->roce.route_resolved = true;
	return 0;
}

/**
 * rdma_addr_cancel - Cancel resolve ip request
 * @addr:	Pointer to address structure given previously
 *		during rdma_resolve_ip().
 * rdma_addr_cancel() is synchronous function which cancels any pending
 * request if there is any.
 */
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);
	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 ib_gid_attr *sgid_attr,
				 int *hoplimit)
{
	struct rdma_dev_addr dev_addr;
	struct resolve_cb_context ctx;
	union rdma_sockaddr 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.net = &init_net;
	dev_addr.sgid_attr = sgid_attr;

	init_completion(&ctx.comp);
	ret = rdma_resolve_ip(&sgid_addr._sockaddr, &dgid_addr._sockaddr,
			      &dev_addr, 1000, resolve_cb, true, &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;
}

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

	return 0;
}

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