/* * 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; struct rdma_addr_client *client; 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 void process_req(struct work_struct *work); static DEFINE_MUTEX(lock); static LIST_HEAD(req_list); static DECLARE_DELAYED_WORK(work, process_req); 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)); } mutex_lock(&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; } mutex_unlock(&lock); if (!found) pr_info("Couldn't find request waiting for DGID: %pI6\n", &gid); } int ib_nl_handle_ip_res_resp(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { if ((nlh->nlmsg_flags & NLM_F_REQUEST) || !(NETLINK_CB(skb).sk)) return -EPERM; if (ib_nl_is_good_ip_resp(nlh)) ib_nl_process_good_ip_rsep(nlh); return skb->len; } static int ib_nl_ip_send_msg(struct rdma_dev_addr *dev_addr, const void *daddr, u32 seq, u16 family) { struct sk_buff *skb = NULL; struct nlmsghdr *nlh; struct rdma_ls_ip_resolve_header *header; void *data; size_t size; int attrtype; int len; if (family == AF_INET) { size = sizeof(struct in_addr); attrtype = RDMA_NLA_F_MANDATORY | LS_NLA_TYPE_IPV4; } else { size = sizeof(struct in6_addr); attrtype = RDMA_NLA_F_MANDATORY | LS_NLA_TYPE_IPV6; } len = nla_total_size(sizeof(size)); len += NLMSG_ALIGN(sizeof(*header)); skb = nlmsg_new(len, GFP_KERNEL); if (!skb) return -ENOMEM; data = ibnl_put_msg(skb, &nlh, seq, 0, RDMA_NL_LS, RDMA_NL_LS_OP_IP_RESOLVE, NLM_F_REQUEST); if (!data) { nlmsg_free(skb); return -ENODATA; } /* Construct the family header first */ header = skb_put(skb, NLMSG_ALIGN(sizeof(*header))); header->ifindex = dev_addr->bound_dev_if; nla_put(skb, attrtype, size, daddr); /* Repair the nlmsg header length */ nlmsg_end(skb, nlh); rdma_nl_multicast(skb, RDMA_NL_GROUP_LS, GFP_KERNEL); /* Make the request retry, so when we get the response from userspace * we will have something. */ return -ENODATA; } int rdma_addr_size(struct sockaddr *addr) { switch (addr->sa_family) { case AF_INET: return sizeof(struct sockaddr_in); case AF_INET6: return sizeof(struct sockaddr_in6); case AF_IB: return sizeof(struct sockaddr_ib); default: return 0; } } EXPORT_SYMBOL(rdma_addr_size); static struct rdma_addr_client self; void rdma_addr_register_client(struct rdma_addr_client *client) { atomic_set(&client->refcount, 1); init_completion(&client->comp); } EXPORT_SYMBOL(rdma_addr_register_client); static inline void put_client(struct rdma_addr_client *client) { if (atomic_dec_and_test(&client->refcount)) complete(&client->comp); } void rdma_addr_unregister_client(struct rdma_addr_client *client) { put_client(client); wait_for_completion(&client->comp); } EXPORT_SYMBOL(rdma_addr_unregister_client); 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, u16 *vlan_id) { 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_addr->bound_dev_if = dev->ifindex; if (vlan_id) *vlan_id = rdma_vlan_dev_vlan_id(dev); 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); dev_addr->bound_dev_if = dev->ifindex; if (vlan_id) *vlan_id = rdma_vlan_dev_vlan_id(dev); break; } } rcu_read_unlock(); break; #endif } return 0; } EXPORT_SYMBOL(rdma_translate_ip); static void set_timeout(struct delayed_work *delayed_work, unsigned long time) { unsigned long delay; delay = time - jiffies; if ((long)delay < 0) delay = 0; mod_delayed_work(addr_wq, delayed_work, delay); } static void queue_req(struct addr_req *req) { struct addr_req *temp_req; mutex_lock(&lock); list_for_each_entry_reverse(temp_req, &req_list, list) { if (time_after_eq(req->timeout, temp_req->timeout)) break; } list_add(&req->list, &temp_req->list); set_timeout(&req->work, req->timeout); mutex_unlock(&lock); } static int ib_nl_fetch_ha(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(struct dst_entry *dst, struct rdma_dev_addr *dev_addr, const void *daddr) { struct neighbour *n; int ret = 0; n = dst_neigh_lookup(dst, daddr); rcu_read_lock(); if (!n || !(n->nud_state & NUD_VALID)) { if (n) neigh_event_send(n, NULL); ret = -ENODATA; } else { rdma_copy_addr(dev_addr, dst->dev, n->ha); } rcu_read_unlock(); if (n) neigh_release(n); return ret; } static bool has_gateway(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(struct dst_entry *dst, struct rdma_dev_addr *dev_addr, const struct sockaddr *dst_in, u32 seq) { const struct sockaddr_in *dst_in4 = (const struct sockaddr_in *)dst_in; const struct sockaddr_in6 *dst_in6 = (const struct sockaddr_in6 *)dst_in; const void *daddr = (dst_in->sa_family == AF_INET) ? (const void *)&dst_in4->sin_addr.s_addr : (const void *)&dst_in6->sin6_addr; sa_family_t family = dst_in->sa_family; /* Gateway + ARPHRD_INFINIBAND -> IB router */ if (has_gateway(dst, family) && dst->dev->type == ARPHRD_INFINIBAND) return ib_nl_fetch_ha(dst, dev_addr, daddr, seq, family); else return dst_fetch_ha(dst, dev_addr, daddr); } static int addr4_resolve(struct sockaddr_in *src_in, const struct sockaddr_in *dst_in, struct rdma_dev_addr *addr, struct rtable **prt) { __be32 src_ip = src_in->sin_addr.s_addr; __be32 dst_ip = dst_in->sin_addr.s_addr; struct rtable *rt; struct flowi4 fl4; int ret; memset(&fl4, 0, sizeof(fl4)); fl4.daddr = dst_ip; fl4.saddr = src_ip; fl4.flowi4_oif = addr->bound_dev_if; rt = ip_route_output_key(addr->net, &fl4); ret = PTR_ERR_OR_ZERO(rt); if (ret) return ret; src_in->sin_family = AF_INET; src_in->sin_addr.s_addr = fl4.saddr; /* If there's a gateway and type of device not ARPHRD_INFINIBAND, we're * definitely in RoCE v2 (as RoCE v1 isn't routable) set the network * type accordingly. */ if (rt->rt_uses_gateway && rt->dst.dev->type != ARPHRD_INFINIBAND) addr->network = RDMA_NETWORK_IPV4; addr->hoplimit = ip4_dst_hoplimit(&rt->dst); *prt = rt; return 0; } #if IS_ENABLED(CONFIG_IPV6) static int addr6_resolve(struct sockaddr_in6 *src_in, const struct sockaddr_in6 *dst_in, struct rdma_dev_addr *addr, struct dst_entry **pdst) { struct flowi6 fl6; struct dst_entry *dst; struct rt6_info *rt; int ret; memset(&fl6, 0, sizeof fl6); fl6.daddr = dst_in->sin6_addr; fl6.saddr = src_in->sin6_addr; fl6.flowi6_oif = addr->bound_dev_if; ret = ipv6_stub->ipv6_dst_lookup(addr->net, NULL, &dst, &fl6); if (ret < 0) return ret; rt = (struct rt6_info *)dst; if (ipv6_addr_any(&src_in->sin6_addr)) { src_in->sin6_family = AF_INET6; src_in->sin6_addr = fl6.saddr; } /* If there's a gateway and type of device not ARPHRD_INFINIBAND, we're * definitely in RoCE v2 (as RoCE v1 isn't routable) set the network * type accordingly. */ if (rt->rt6i_flags & RTF_GATEWAY && ip6_dst_idev(dst)->dev->type != ARPHRD_INFINIBAND) addr->network = RDMA_NETWORK_IPV6; addr->hoplimit = ip6_dst_hoplimit(dst); *pdst = dst; return 0; } #else static int addr6_resolve(struct sockaddr_in6 *src_in, const struct sockaddr_in6 *dst_in, struct rdma_dev_addr *addr, struct dst_entry **pdst) { return -EADDRNOTAVAIL; } #endif static int addr_resolve_neigh(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, NULL); 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->flags & IFF_LOOPBACK) { ret = rdma_translate_ip(dst_in, addr, NULL); /* * Put the loopback device and get the translated * device instead. */ dev_put(ndev); ndev = dev_get_by_index(addr->net, addr->bound_dev_if); } 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; mutex_lock(&lock); 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 */ set_timeout(&req->work, req->timeout); mutex_unlock(&lock); return; } } list_del(&req->list); mutex_unlock(&lock); req->callback(req->status, (struct sockaddr *)&req->src_addr, req->addr, req->context); put_client(req->client); kfree(req); } static void process_req(struct work_struct *work) { struct addr_req *req, *temp_req; struct sockaddr *src_in, *dst_in; struct list_head done_list; INIT_LIST_HEAD(&done_list); mutex_lock(&lock); list_for_each_entry_safe(req, temp_req, &req_list, list) { 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) { set_timeout(&req->work, req->timeout); continue; } } list_move_tail(&req->list, &done_list); } mutex_unlock(&lock); list_for_each_entry_safe(req, temp_req, &done_list, list) { list_del(&req->list); /* It is safe to cancel other work items from this work item * because at a time there can be only one work item running * with this single threaded work queue. */ cancel_delayed_work(&req->work); req->callback(req->status, (struct sockaddr *) &req->src_addr, req->addr, req->context); put_client(req->client); kfree(req); } } int rdma_resolve_ip(struct rdma_addr_client *client, struct sockaddr *src_addr, struct sockaddr *dst_addr, struct rdma_dev_addr *addr, int timeout_ms, void (*callback)(int status, struct sockaddr *src_addr, struct rdma_dev_addr *addr, void *context), void *context) { struct sockaddr *src_in, *dst_in; struct addr_req *req; int ret = 0; req = kzalloc(sizeof *req, GFP_KERNEL); if (!req) return -ENOMEM; src_in = (struct sockaddr *) &req->src_addr; dst_in = (struct sockaddr *) &req->dst_addr; if (src_addr) { if (src_addr->sa_family != dst_addr->sa_family) { ret = -EINVAL; goto err; } memcpy(src_in, src_addr, rdma_addr_size(src_addr)); } else { src_in->sa_family = dst_addr->sa_family; } memcpy(dst_in, dst_addr, rdma_addr_size(dst_addr)); req->addr = addr; req->callback = callback; req->context = context; req->client = client; atomic_inc(&client->refcount); 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; atomic_dec(&client->refcount); 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); } EXPORT_SYMBOL(rdma_resolve_ip_route); void rdma_addr_cancel(struct rdma_dev_addr *addr) { struct addr_req *req, *temp_req; mutex_lock(&lock); list_for_each_entry_safe(req, temp_req, &req_list, list) { if (req->addr == addr) { req->status = -ECANCELED; req->timeout = jiffies; list_move(&req->list, &req_list); set_timeout(&req->work, req->timeout); break; } } mutex_unlock(&lock); } EXPORT_SYMBOL(rdma_addr_cancel); struct resolve_cb_context { struct rdma_dev_addr *addr; struct completion comp; int status; }; static void resolve_cb(int status, struct sockaddr *src_addr, struct rdma_dev_addr *addr, void *context) { if (!status) memcpy(((struct resolve_cb_context *)context)->addr, addr, sizeof(struct rdma_dev_addr)); ((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, u16 *vlan_id, int *if_index, int *hoplimit) { int ret = 0; struct rdma_dev_addr dev_addr; struct resolve_cb_context ctx; struct net_device *dev; union { struct sockaddr _sockaddr; struct sockaddr_in _sockaddr_in; struct sockaddr_in6 _sockaddr_in6; } sgid_addr, dgid_addr; rdma_gid2ip(&sgid_addr._sockaddr, sgid); rdma_gid2ip(&dgid_addr._sockaddr, dgid); memset(&dev_addr, 0, sizeof(dev_addr)); if (if_index) dev_addr.bound_dev_if = *if_index; dev_addr.net = &init_net; ctx.addr = &dev_addr; init_completion(&ctx.comp); ret = rdma_resolve_ip(&self, &sgid_addr._sockaddr, &dgid_addr._sockaddr, &dev_addr, 1000, resolve_cb, &ctx); if (ret) return ret; wait_for_completion(&ctx.comp); ret = ctx.status; if (ret) return ret; memcpy(dmac, dev_addr.dst_dev_addr, ETH_ALEN); dev = dev_get_by_index(&init_net, dev_addr.bound_dev_if); if (!dev) return -ENODEV; if (if_index) *if_index = dev_addr.bound_dev_if; if (vlan_id) *vlan_id = rdma_vlan_dev_vlan_id(dev); if (hoplimit) *hoplimit = dev_addr.hoplimit; dev_put(dev); return ret; } EXPORT_SYMBOL(rdma_addr_find_l2_eth_by_grh); int rdma_addr_find_smac_by_sgid(union ib_gid *sgid, u8 *smac, u16 *vlan_id) { int ret = 0; struct rdma_dev_addr dev_addr; union { struct sockaddr _sockaddr; struct sockaddr_in _sockaddr_in; struct sockaddr_in6 _sockaddr_in6; } gid_addr; rdma_gid2ip(&gid_addr._sockaddr, sgid); memset(&dev_addr, 0, sizeof(dev_addr)); dev_addr.net = &init_net; ret = rdma_translate_ip(&gid_addr._sockaddr, &dev_addr, vlan_id); if (ret) return ret; memcpy(smac, dev_addr.src_dev_addr, ETH_ALEN); return ret; } EXPORT_SYMBOL(rdma_addr_find_smac_by_sgid); static int netevent_callback(struct notifier_block *self, unsigned long event, void *ctx) { if (event == NETEVENT_NEIGH_UPDATE) { struct neighbour *neigh = ctx; if (neigh->nud_state & NUD_VALID) set_timeout(&work, jiffies); } 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); rdma_addr_register_client(&self); return 0; } void addr_cleanup(void) { rdma_addr_unregister_client(&self); unregister_netevent_notifier(&nb); destroy_workqueue(addr_wq); }