/*-
 * 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));
}