2 * Copyright (c) 2005 Voltaire Inc. All rights reserved.
3 * Copyright (c) 2002-2005, Network Appliance, Inc. All rights reserved.
4 * Copyright (c) 1999-2005, Mellanox Technologies, Inc. All rights reserved.
5 * Copyright (c) 2005 Intel Corporation. All rights reserved.
7 * This software is available to you under a choice of one of two
8 * licenses. You may choose to be licensed under the terms of the GNU
9 * General Public License (GPL) Version 2, available from the file
10 * COPYING in the main directory of this source tree, or the
11 * OpenIB.org BSD license below:
13 * Redistribution and use in source and binary forms, with or
14 * without modification, are permitted provided that the following
17 * - Redistributions of source code must retain the above
18 * copyright notice, this list of conditions and the following
21 * - Redistributions in binary form must reproduce the above
22 * copyright notice, this list of conditions and the following
23 * disclaimer in the documentation and/or other materials
24 * provided with the distribution.
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
27 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
28 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
29 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
30 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
31 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
32 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
36 #include <linux/mutex.h>
37 #include <linux/inetdevice.h>
38 #include <linux/slab.h>
39 #include <linux/workqueue.h>
40 #include <linux/module.h>
42 #include <net/neighbour.h>
43 #include <net/route.h>
44 #include <net/netevent.h>
45 #include <net/ipv6_stubs.h>
46 #include <net/ip6_route.h>
47 #include <rdma/ib_addr.h>
48 #include <rdma/ib_cache.h>
49 #include <rdma/ib_sa.h>
51 #include <rdma/rdma_netlink.h>
52 #include <net/netlink.h>
54 #include "core_priv.h"
57 struct list_head list;
58 struct sockaddr_storage src_addr;
59 struct sockaddr_storage dst_addr;
60 struct rdma_dev_addr *addr;
62 void (*callback)(int status, struct sockaddr *src_addr,
63 struct rdma_dev_addr *addr, void *context);
64 unsigned long timeout;
65 struct delayed_work work;
66 bool resolve_by_gid_attr; /* Consider gid attr in resolve phase */
71 static atomic_t ib_nl_addr_request_seq = ATOMIC_INIT(0);
73 static DEFINE_SPINLOCK(lock);
74 static LIST_HEAD(req_list);
75 static struct workqueue_struct *addr_wq;
77 static const struct nla_policy ib_nl_addr_policy[LS_NLA_TYPE_MAX] = {
78 [LS_NLA_TYPE_DGID] = {.type = NLA_BINARY,
79 .len = sizeof(struct rdma_nla_ls_gid)},
82 static inline bool ib_nl_is_good_ip_resp(const struct nlmsghdr *nlh)
84 struct nlattr *tb[LS_NLA_TYPE_MAX] = {};
87 if (nlh->nlmsg_flags & RDMA_NL_LS_F_ERR)
90 ret = nla_parse_deprecated(tb, LS_NLA_TYPE_MAX - 1, nlmsg_data(nlh),
91 nlmsg_len(nlh), ib_nl_addr_policy, NULL);
98 static void ib_nl_process_good_ip_rsep(const struct nlmsghdr *nlh)
100 const struct nlattr *head, *curr;
102 struct addr_req *req;
106 head = (const struct nlattr *)nlmsg_data(nlh);
107 len = nlmsg_len(nlh);
109 nla_for_each_attr(curr, head, len, rem) {
110 if (curr->nla_type == LS_NLA_TYPE_DGID)
111 memcpy(&gid, nla_data(curr), nla_len(curr));
115 list_for_each_entry(req, &req_list, list) {
116 if (nlh->nlmsg_seq != req->seq)
118 /* We set the DGID part, the rest was set earlier */
119 rdma_addr_set_dgid(req->addr, &gid);
124 spin_unlock_bh(&lock);
127 pr_info("Couldn't find request waiting for DGID: %pI6\n",
131 int ib_nl_handle_ip_res_resp(struct sk_buff *skb,
132 struct nlmsghdr *nlh,
133 struct netlink_ext_ack *extack)
135 if ((nlh->nlmsg_flags & NLM_F_REQUEST) ||
136 !(NETLINK_CB(skb).sk))
139 if (ib_nl_is_good_ip_resp(nlh))
140 ib_nl_process_good_ip_rsep(nlh);
145 static int ib_nl_ip_send_msg(struct rdma_dev_addr *dev_addr,
149 struct sk_buff *skb = NULL;
150 struct nlmsghdr *nlh;
151 struct rdma_ls_ip_resolve_header *header;
157 if (family == AF_INET) {
158 size = sizeof(struct in_addr);
159 attrtype = RDMA_NLA_F_MANDATORY | LS_NLA_TYPE_IPV4;
161 size = sizeof(struct in6_addr);
162 attrtype = RDMA_NLA_F_MANDATORY | LS_NLA_TYPE_IPV6;
165 len = nla_total_size(sizeof(size));
166 len += NLMSG_ALIGN(sizeof(*header));
168 skb = nlmsg_new(len, GFP_KERNEL);
172 data = ibnl_put_msg(skb, &nlh, seq, 0, RDMA_NL_LS,
173 RDMA_NL_LS_OP_IP_RESOLVE, NLM_F_REQUEST);
179 /* Construct the family header first */
180 header = skb_put(skb, NLMSG_ALIGN(sizeof(*header)));
181 header->ifindex = dev_addr->bound_dev_if;
182 nla_put(skb, attrtype, size, daddr);
184 /* Repair the nlmsg header length */
186 rdma_nl_multicast(&init_net, skb, RDMA_NL_GROUP_LS, GFP_KERNEL);
188 /* Make the request retry, so when we get the response from userspace
189 * we will have something.
194 int rdma_addr_size(const struct sockaddr *addr)
196 switch (addr->sa_family) {
198 return sizeof(struct sockaddr_in);
200 return sizeof(struct sockaddr_in6);
202 return sizeof(struct sockaddr_ib);
207 EXPORT_SYMBOL(rdma_addr_size);
209 int rdma_addr_size_in6(struct sockaddr_in6 *addr)
211 int ret = rdma_addr_size((struct sockaddr *) addr);
213 return ret <= sizeof(*addr) ? ret : 0;
215 EXPORT_SYMBOL(rdma_addr_size_in6);
217 int rdma_addr_size_kss(struct __kernel_sockaddr_storage *addr)
219 int ret = rdma_addr_size((struct sockaddr *) addr);
221 return ret <= sizeof(*addr) ? ret : 0;
223 EXPORT_SYMBOL(rdma_addr_size_kss);
226 * rdma_copy_src_l2_addr - Copy netdevice source addresses
227 * @dev_addr: Destination address pointer where to copy the addresses
228 * @dev: Netdevice whose source addresses to copy
230 * rdma_copy_src_l2_addr() copies source addresses from the specified netdevice.
231 * This includes unicast address, broadcast address, device type and
234 void rdma_copy_src_l2_addr(struct rdma_dev_addr *dev_addr,
235 const struct net_device *dev)
237 dev_addr->dev_type = dev->type;
238 memcpy(dev_addr->src_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
239 memcpy(dev_addr->broadcast, dev->broadcast, MAX_ADDR_LEN);
240 dev_addr->bound_dev_if = dev->ifindex;
242 EXPORT_SYMBOL(rdma_copy_src_l2_addr);
244 static struct net_device *
245 rdma_find_ndev_for_src_ip_rcu(struct net *net, const struct sockaddr *src_in)
247 struct net_device *dev = NULL;
248 int ret = -EADDRNOTAVAIL;
250 switch (src_in->sa_family) {
252 dev = __ip_dev_find(net,
253 ((const struct sockaddr_in *)src_in)->sin_addr.s_addr,
258 #if IS_ENABLED(CONFIG_IPV6)
260 for_each_netdev_rcu(net, dev) {
261 if (ipv6_chk_addr(net,
262 &((const struct sockaddr_in6 *)src_in)->sin6_addr,
271 return ret ? ERR_PTR(ret) : dev;
274 int rdma_translate_ip(const struct sockaddr *addr,
275 struct rdma_dev_addr *dev_addr)
277 struct net_device *dev;
279 if (dev_addr->bound_dev_if) {
280 dev = dev_get_by_index(dev_addr->net, dev_addr->bound_dev_if);
283 rdma_copy_src_l2_addr(dev_addr, dev);
289 dev = rdma_find_ndev_for_src_ip_rcu(dev_addr->net, addr);
291 rdma_copy_src_l2_addr(dev_addr, dev);
293 return PTR_ERR_OR_ZERO(dev);
295 EXPORT_SYMBOL(rdma_translate_ip);
297 static void set_timeout(struct addr_req *req, unsigned long time)
301 delay = time - jiffies;
305 mod_delayed_work(addr_wq, &req->work, delay);
308 static void queue_req(struct addr_req *req)
311 list_add_tail(&req->list, &req_list);
312 set_timeout(req, req->timeout);
313 spin_unlock_bh(&lock);
316 static int ib_nl_fetch_ha(struct rdma_dev_addr *dev_addr,
317 const void *daddr, u32 seq, u16 family)
319 if (!rdma_nl_chk_listeners(RDMA_NL_GROUP_LS))
320 return -EADDRNOTAVAIL;
322 return ib_nl_ip_send_msg(dev_addr, daddr, seq, family);
325 static int dst_fetch_ha(const struct dst_entry *dst,
326 struct rdma_dev_addr *dev_addr,
332 n = dst_neigh_lookup(dst, daddr);
336 if (!(n->nud_state & NUD_VALID)) {
337 neigh_event_send(n, NULL);
340 neigh_ha_snapshot(dev_addr->dst_dev_addr, n, dst->dev);
348 static bool has_gateway(const struct dst_entry *dst, sa_family_t family)
351 struct rt6_info *rt6;
353 if (family == AF_INET) {
354 rt = container_of(dst, struct rtable, dst);
355 return rt->rt_uses_gateway;
358 rt6 = container_of(dst, struct rt6_info, dst);
359 return rt6->rt6i_flags & RTF_GATEWAY;
362 static int fetch_ha(const struct dst_entry *dst, struct rdma_dev_addr *dev_addr,
363 const struct sockaddr *dst_in, u32 seq)
365 const struct sockaddr_in *dst_in4 =
366 (const struct sockaddr_in *)dst_in;
367 const struct sockaddr_in6 *dst_in6 =
368 (const struct sockaddr_in6 *)dst_in;
369 const void *daddr = (dst_in->sa_family == AF_INET) ?
370 (const void *)&dst_in4->sin_addr.s_addr :
371 (const void *)&dst_in6->sin6_addr;
372 sa_family_t family = dst_in->sa_family;
374 /* If we have a gateway in IB mode then it must be an IB network */
375 if (has_gateway(dst, family) && dev_addr->network == RDMA_NETWORK_IB)
376 return ib_nl_fetch_ha(dev_addr, daddr, seq, family);
378 return dst_fetch_ha(dst, dev_addr, daddr);
381 static int addr4_resolve(struct sockaddr *src_sock,
382 const struct sockaddr *dst_sock,
383 struct rdma_dev_addr *addr,
386 struct sockaddr_in *src_in = (struct sockaddr_in *)src_sock;
387 const struct sockaddr_in *dst_in =
388 (const struct sockaddr_in *)dst_sock;
390 __be32 src_ip = src_in->sin_addr.s_addr;
391 __be32 dst_ip = dst_in->sin_addr.s_addr;
396 memset(&fl4, 0, sizeof(fl4));
399 fl4.flowi4_oif = addr->bound_dev_if;
400 rt = ip_route_output_key(addr->net, &fl4);
401 ret = PTR_ERR_OR_ZERO(rt);
405 src_in->sin_addr.s_addr = fl4.saddr;
407 addr->hoplimit = ip4_dst_hoplimit(&rt->dst);
413 #if IS_ENABLED(CONFIG_IPV6)
414 static int addr6_resolve(struct sockaddr *src_sock,
415 const struct sockaddr *dst_sock,
416 struct rdma_dev_addr *addr,
417 struct dst_entry **pdst)
419 struct sockaddr_in6 *src_in = (struct sockaddr_in6 *)src_sock;
420 const struct sockaddr_in6 *dst_in =
421 (const struct sockaddr_in6 *)dst_sock;
423 struct dst_entry *dst;
425 memset(&fl6, 0, sizeof fl6);
426 fl6.daddr = dst_in->sin6_addr;
427 fl6.saddr = src_in->sin6_addr;
428 fl6.flowi6_oif = addr->bound_dev_if;
430 dst = ipv6_stub->ipv6_dst_lookup_flow(addr->net, NULL, &fl6, NULL);
434 if (ipv6_addr_any(&src_in->sin6_addr))
435 src_in->sin6_addr = fl6.saddr;
437 addr->hoplimit = ip6_dst_hoplimit(dst);
443 static int addr6_resolve(struct sockaddr *src_sock,
444 const struct sockaddr *dst_sock,
445 struct rdma_dev_addr *addr,
446 struct dst_entry **pdst)
448 return -EADDRNOTAVAIL;
452 static int addr_resolve_neigh(const struct dst_entry *dst,
453 const struct sockaddr *dst_in,
454 struct rdma_dev_addr *addr,
455 unsigned int ndev_flags,
460 if (ndev_flags & IFF_LOOPBACK) {
461 memcpy(addr->dst_dev_addr, addr->src_dev_addr, MAX_ADDR_LEN);
463 if (!(ndev_flags & IFF_NOARP)) {
464 /* If the device doesn't do ARP internally */
465 ret = fetch_ha(dst, addr, dst_in, seq);
471 static int copy_src_l2_addr(struct rdma_dev_addr *dev_addr,
472 const struct sockaddr *dst_in,
473 const struct dst_entry *dst,
474 const struct net_device *ndev)
478 if (dst->dev->flags & IFF_LOOPBACK)
479 ret = rdma_translate_ip(dst_in, dev_addr);
481 rdma_copy_src_l2_addr(dev_addr, dst->dev);
484 * If there's a gateway and type of device not ARPHRD_INFINIBAND,
485 * we're definitely in RoCE v2 (as RoCE v1 isn't routable) set the
486 * network type accordingly.
488 if (has_gateway(dst, dst_in->sa_family) &&
489 ndev->type != ARPHRD_INFINIBAND)
490 dev_addr->network = dst_in->sa_family == AF_INET ?
494 dev_addr->network = RDMA_NETWORK_IB;
499 static int rdma_set_src_addr_rcu(struct rdma_dev_addr *dev_addr,
500 unsigned int *ndev_flags,
501 const struct sockaddr *dst_in,
502 const struct dst_entry *dst)
504 struct net_device *ndev = READ_ONCE(dst->dev);
506 *ndev_flags = ndev->flags;
507 /* A physical device must be the RDMA device to use */
508 if (ndev->flags & IFF_LOOPBACK) {
510 * RDMA (IB/RoCE, iWarp) doesn't run on lo interface or
511 * loopback IP address. So if route is resolved to loopback
512 * interface, translate that to a real ndev based on non
513 * loopback IP address.
515 ndev = rdma_find_ndev_for_src_ip_rcu(dev_net(ndev), dst_in);
520 return copy_src_l2_addr(dev_addr, dst_in, dst, ndev);
523 static int set_addr_netns_by_gid_rcu(struct rdma_dev_addr *addr)
525 struct net_device *ndev;
527 ndev = rdma_read_gid_attr_ndev_rcu(addr->sgid_attr);
529 return PTR_ERR(ndev);
532 * Since we are holding the rcu, reading net and ifindex
533 * are safe without any additional reference; because
534 * change_net_namespace() in net/core/dev.c does rcu sync
535 * after it changes the state to IFF_DOWN and before
536 * updating netdev fields {net, ifindex}.
538 addr->net = dev_net(ndev);
539 addr->bound_dev_if = ndev->ifindex;
543 static void rdma_addr_set_net_defaults(struct rdma_dev_addr *addr)
545 addr->net = &init_net;
546 addr->bound_dev_if = 0;
549 static int addr_resolve(struct sockaddr *src_in,
550 const struct sockaddr *dst_in,
551 struct rdma_dev_addr *addr,
553 bool resolve_by_gid_attr,
556 struct dst_entry *dst = NULL;
557 unsigned int ndev_flags = 0;
558 struct rtable *rt = NULL;
562 pr_warn_ratelimited("%s: missing namespace\n", __func__);
567 if (resolve_by_gid_attr) {
568 if (!addr->sgid_attr) {
570 pr_warn_ratelimited("%s: missing gid_attr\n", __func__);
574 * If the request is for a specific gid attribute of the
575 * rdma_dev_addr, derive net from the netdevice of the
578 ret = set_addr_netns_by_gid_rcu(addr);
584 if (src_in->sa_family == AF_INET) {
585 ret = addr4_resolve(src_in, dst_in, addr, &rt);
588 ret = addr6_resolve(src_in, dst_in, addr, &dst);
594 ret = rdma_set_src_addr_rcu(addr, &ndev_flags, dst_in, dst);
598 * Resolve neighbor destination address if requested and
599 * only if src addr translation didn't fail.
601 if (!ret && resolve_neigh)
602 ret = addr_resolve_neigh(dst, dst_in, addr, ndev_flags, seq);
604 if (src_in->sa_family == AF_INET)
610 * Clear the addr net to go back to its original state, only if it was
611 * derived from GID attribute in this context.
613 if (resolve_by_gid_attr)
614 rdma_addr_set_net_defaults(addr);
618 static void process_one_req(struct work_struct *_work)
620 struct addr_req *req;
621 struct sockaddr *src_in, *dst_in;
623 req = container_of(_work, struct addr_req, work.work);
625 if (req->status == -ENODATA) {
626 src_in = (struct sockaddr *)&req->src_addr;
627 dst_in = (struct sockaddr *)&req->dst_addr;
628 req->status = addr_resolve(src_in, dst_in, req->addr,
629 true, req->resolve_by_gid_attr,
631 if (req->status && time_after_eq(jiffies, req->timeout)) {
632 req->status = -ETIMEDOUT;
633 } else if (req->status == -ENODATA) {
634 /* requeue the work for retrying again */
636 if (!list_empty(&req->list))
637 set_timeout(req, req->timeout);
638 spin_unlock_bh(&lock);
643 req->callback(req->status, (struct sockaddr *)&req->src_addr,
644 req->addr, req->context);
645 req->callback = NULL;
648 if (!list_empty(&req->list)) {
650 * Although the work will normally have been canceled by the
651 * workqueue, it can still be requeued as long as it is on the
654 cancel_delayed_work(&req->work);
655 list_del_init(&req->list);
658 spin_unlock_bh(&lock);
661 int rdma_resolve_ip(struct sockaddr *src_addr, const struct sockaddr *dst_addr,
662 struct rdma_dev_addr *addr, unsigned long timeout_ms,
663 void (*callback)(int status, struct sockaddr *src_addr,
664 struct rdma_dev_addr *addr, void *context),
665 bool resolve_by_gid_attr, void *context)
667 struct sockaddr *src_in, *dst_in;
668 struct addr_req *req;
671 req = kzalloc(sizeof *req, GFP_KERNEL);
675 src_in = (struct sockaddr *) &req->src_addr;
676 dst_in = (struct sockaddr *) &req->dst_addr;
679 if (src_addr->sa_family != dst_addr->sa_family) {
684 memcpy(src_in, src_addr, rdma_addr_size(src_addr));
686 src_in->sa_family = dst_addr->sa_family;
689 memcpy(dst_in, dst_addr, rdma_addr_size(dst_addr));
691 req->callback = callback;
692 req->context = context;
693 req->resolve_by_gid_attr = resolve_by_gid_attr;
694 INIT_DELAYED_WORK(&req->work, process_one_req);
695 req->seq = (u32)atomic_inc_return(&ib_nl_addr_request_seq);
697 req->status = addr_resolve(src_in, dst_in, addr, true,
698 req->resolve_by_gid_attr, req->seq);
699 switch (req->status) {
701 req->timeout = jiffies;
705 req->timeout = msecs_to_jiffies(timeout_ms) + jiffies;
717 EXPORT_SYMBOL(rdma_resolve_ip);
719 int roce_resolve_route_from_path(struct sa_path_rec *rec,
720 const struct ib_gid_attr *attr)
723 struct sockaddr _sockaddr;
724 struct sockaddr_in _sockaddr_in;
725 struct sockaddr_in6 _sockaddr_in6;
727 struct rdma_dev_addr dev_addr = {};
730 if (rec->roce.route_resolved)
733 rdma_gid2ip((struct sockaddr *)&sgid, &rec->sgid);
734 rdma_gid2ip((struct sockaddr *)&dgid, &rec->dgid);
736 if (sgid._sockaddr.sa_family != dgid._sockaddr.sa_family)
739 if (!attr || !attr->ndev)
742 dev_addr.net = &init_net;
743 dev_addr.sgid_attr = attr;
745 ret = addr_resolve((struct sockaddr *)&sgid, (struct sockaddr *)&dgid,
746 &dev_addr, false, true, 0);
750 if ((dev_addr.network == RDMA_NETWORK_IPV4 ||
751 dev_addr.network == RDMA_NETWORK_IPV6) &&
752 rec->rec_type != SA_PATH_REC_TYPE_ROCE_V2)
755 rec->roce.route_resolved = true;
760 * rdma_addr_cancel - Cancel resolve ip request
761 * @addr: Pointer to address structure given previously
762 * during rdma_resolve_ip().
763 * rdma_addr_cancel() is synchronous function which cancels any pending
764 * request if there is any.
766 void rdma_addr_cancel(struct rdma_dev_addr *addr)
768 struct addr_req *req, *temp_req;
769 struct addr_req *found = NULL;
772 list_for_each_entry_safe(req, temp_req, &req_list, list) {
773 if (req->addr == addr) {
775 * Removing from the list means we take ownership of
778 list_del_init(&req->list);
783 spin_unlock_bh(&lock);
789 * sync canceling the work after removing it from the req_list
790 * guarentees no work is running and none will be started.
792 cancel_delayed_work_sync(&found->work);
795 EXPORT_SYMBOL(rdma_addr_cancel);
797 struct resolve_cb_context {
798 struct completion comp;
802 static void resolve_cb(int status, struct sockaddr *src_addr,
803 struct rdma_dev_addr *addr, void *context)
805 ((struct resolve_cb_context *)context)->status = status;
806 complete(&((struct resolve_cb_context *)context)->comp);
809 int rdma_addr_find_l2_eth_by_grh(const union ib_gid *sgid,
810 const union ib_gid *dgid,
811 u8 *dmac, const struct ib_gid_attr *sgid_attr,
814 struct rdma_dev_addr dev_addr;
815 struct resolve_cb_context ctx;
817 struct sockaddr_in _sockaddr_in;
818 struct sockaddr_in6 _sockaddr_in6;
819 } sgid_addr, dgid_addr;
822 rdma_gid2ip((struct sockaddr *)&sgid_addr, sgid);
823 rdma_gid2ip((struct sockaddr *)&dgid_addr, dgid);
825 memset(&dev_addr, 0, sizeof(dev_addr));
826 dev_addr.net = &init_net;
827 dev_addr.sgid_attr = sgid_attr;
829 init_completion(&ctx.comp);
830 ret = rdma_resolve_ip((struct sockaddr *)&sgid_addr,
831 (struct sockaddr *)&dgid_addr, &dev_addr, 1000,
832 resolve_cb, true, &ctx);
836 wait_for_completion(&ctx.comp);
842 memcpy(dmac, dev_addr.dst_dev_addr, ETH_ALEN);
843 *hoplimit = dev_addr.hoplimit;
847 static int netevent_callback(struct notifier_block *self, unsigned long event,
850 struct addr_req *req;
852 if (event == NETEVENT_NEIGH_UPDATE) {
853 struct neighbour *neigh = ctx;
855 if (neigh->nud_state & NUD_VALID) {
857 list_for_each_entry(req, &req_list, list)
858 set_timeout(req, jiffies);
859 spin_unlock_bh(&lock);
865 static struct notifier_block nb = {
866 .notifier_call = netevent_callback
871 addr_wq = alloc_ordered_workqueue("ib_addr", 0);
875 register_netevent_notifier(&nb);
880 void addr_cleanup(void)
882 unregister_netevent_notifier(&nb);
883 destroy_workqueue(addr_wq);
884 WARN_ON(!list_empty(&req_list));