text: /*
   * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
   * Copyright (c) 2015 System Fabric Works, Inc. 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/skbuff.h>
  #include <linux/if_arp.h>
  #include <linux/netdevice.h>
  #include <linux/if.h>
  #include <linux/if_vlan.h>
  #include <net/udp_tunnel.h>
  #include <net/sch_generic.h>
  #include <linux/netfilter.h>
  #include <rdma/ib_addr.h>
  
  #include "rxe.h"
  #include "rxe_net.h"
  #include "rxe_loc.h"
  
  static LIST_HEAD(rxe_dev_list);
  static spinlock_t dev_list_lock; /* spinlock for device list */
  
  struct rxe_dev *net_to_rxe(struct net_device *ndev)
  {
  	struct rxe_dev *rxe;
  	struct rxe_dev *found = NULL;
  
  	spin_lock_bh(&dev_list_lock);
  	list_for_each_entry(rxe, &rxe_dev_list, list) {
  		if (rxe->ndev == ndev) {
  			found = rxe;
  			break;
  		}
  	}
  	spin_unlock_bh(&dev_list_lock);
  
  	return found;
  }
  
  struct rxe_dev *get_rxe_by_name(const char *name)
  {
  	struct rxe_dev *rxe;
  	struct rxe_dev *found = NULL;
  
  	spin_lock_bh(&dev_list_lock);
  	list_for_each_entry(rxe, &rxe_dev_list, list) {
  		if (!strcmp(name, rxe->ib_dev.name)) {
  			found = rxe;
  			break;
  		}
  	}
  	spin_unlock_bh(&dev_list_lock);
  	return found;
  }
  
  
  struct rxe_recv_sockets recv_sockets;
  
  static __be64 rxe_mac_to_eui64(struct net_device *ndev)
  {
  	unsigned char *mac_addr = ndev->dev_addr;
  	__be64 eui64;
  	unsigned char *dst = (unsigned char *)&eui64;
  
  	dst[0] = mac_addr[0] ^ 2;
  	dst[1] = mac_addr[1];
  	dst[2] = mac_addr[2];
  	dst[3] = 0xff;
  	dst[4] = 0xfe;
  	dst[5] = mac_addr[3];
  	dst[6] = mac_addr[4];
  	dst[7] = mac_addr[5];
  
  	return eui64;
  }
  
  static __be64 node_guid(struct rxe_dev *rxe)
  {
  	return rxe_mac_to_eui64(rxe->ndev);
  }
  
  static __be64 port_guid(struct rxe_dev *rxe)
  {
  	return rxe_mac_to_eui64(rxe->ndev);
  }
  
  static struct device *dma_device(struct rxe_dev *rxe)
  {
  	struct net_device *ndev;
  
  	ndev = rxe->ndev;
  
  	if (ndev->priv_flags & IFF_802_1Q_VLAN)
  		ndev = vlan_dev_real_dev(ndev);
  
  	return ndev->dev.parent;
  }
  
  static int mcast_add(struct rxe_dev *rxe, union ib_gid *mgid)
  {
  	int err;
  	unsigned char ll_addr[ETH_ALEN];
  
  	ipv6_eth_mc_map((struct in6_addr *)mgid->raw, ll_addr);
  	err = dev_mc_add(rxe->ndev, ll_addr);
  
  	return err;
  }
  
  static int mcast_delete(struct rxe_dev *rxe, union ib_gid *mgid)
  {
  	int err;
  	unsigned char ll_addr[ETH_ALEN];
  
  	ipv6_eth_mc_map((struct in6_addr *)mgid->raw, ll_addr);
  	err = dev_mc_del(rxe->ndev, ll_addr);
  
  	return err;
  }
  
  static struct dst_entry *rxe_find_route4(struct net_device *ndev,
  				  struct in_addr *saddr,
  				  struct in_addr *daddr)
  {
  	struct rtable *rt;
  	struct flowi4 fl = { { 0 } };
  
  	memset(&fl, 0, sizeof(fl));
  	fl.flowi4_oif = ndev->ifindex;
  	memcpy(&fl.saddr, saddr, sizeof(*saddr));
  	memcpy(&fl.daddr, daddr, sizeof(*daddr));
  	fl.flowi4_proto = IPPROTO_UDP;
  
  	rt = ip_route_output_key(&init_net, &fl);
  	if (IS_ERR(rt)) {
  		pr_err_ratelimited("no route to %pI4\n", &daddr->s_addr);
  		return NULL;
  	}
  
  	return &rt->dst;
  }
  
  #if IS_ENABLED(CONFIG_IPV6)
  static struct dst_entry *rxe_find_route6(struct net_device *ndev,
  					 struct in6_addr *saddr,
  					 struct in6_addr *daddr)
  {
  	struct dst_entry *ndst;
  	struct flowi6 fl6 = { { 0 } };
  
  	memset(&fl6, 0, sizeof(fl6));
  	fl6.flowi6_oif = ndev->ifindex;
  	memcpy(&fl6.saddr, saddr, sizeof(*saddr));
  	memcpy(&fl6.daddr, daddr, sizeof(*daddr));
  	fl6.flowi6_proto = IPPROTO_UDP;
  
  	ndst = ipv6_stub->ipv6_dst_lookup_flow(sock_net(recv_sockets.sk6->sk),
  					       recv_sockets.sk6->sk, &fl6,
  					       NULL);
  	if (unlikely(IS_ERR(ndst))) {
  		pr_err_ratelimited("no route to %pI6\n", daddr);
  		return NULL;
  	}
  
  	if (unlikely(ndst->error)) {
  		pr_err("no route to %pI6\n", daddr);
  		goto put;
  	}
  
  	return ndst;
  put:
  	dst_release(ndst);
  	return NULL;
  }
  
  #else
  
  static struct dst_entry *rxe_find_route6(struct net_device *ndev,
  					 struct in6_addr *saddr,
  					 struct in6_addr *daddr)
  {
  	return NULL;
  }
  
  #endif
  
  static int rxe_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
  {
  	struct udphdr *udph;
  	struct net_device *ndev = skb->dev;
  	struct rxe_dev *rxe = net_to_rxe(ndev);
  	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
  
  	if (!rxe)
  		goto drop;
  
  	if (skb_linearize(skb)) {
  		pr_err("skb_linearize failed\n");
  		goto drop;
  	}
  
  	udph = udp_hdr(skb);
  	pkt->rxe = rxe;
  	pkt->port_num = 1;
  	pkt->hdr = (u8 *)(udph + 1);
  	pkt->mask = RXE_GRH_MASK;
  	pkt->paylen = be16_to_cpu(udph->len) - sizeof(*udph);
  
  	return rxe_rcv(skb);
  drop:
  	kfree_skb(skb);
  	return 0;
  }
  
  static struct socket *rxe_setup_udp_tunnel(struct net *net, __be16 port,
  					   bool ipv6)
  {
  	int err;
  	struct socket *sock;
  	struct udp_port_cfg udp_cfg = {0};
  	struct udp_tunnel_sock_cfg tnl_cfg = {0};
  
  	if (ipv6) {
  		udp_cfg.family = AF_INET6;
  		udp_cfg.ipv6_v6only = 1;
  	} else {
  		udp_cfg.family = AF_INET;
  	}
  
  	udp_cfg.local_udp_port = port;
  
  	/* Create UDP socket */
  	err = udp_sock_create(net, &udp_cfg, &sock);
  	if (err < 0) {
  		pr_err("failed to create udp socket. err = %d\n", err);
  		return ERR_PTR(err);
  	}
  
  	tnl_cfg.encap_type = 1;
  	tnl_cfg.encap_rcv = rxe_udp_encap_recv;
  
  	/* Setup UDP tunnel */
  	setup_udp_tunnel_sock(net, sock, &tnl_cfg);
  
  	return sock;
  }
  
  void rxe_release_udp_tunnel(struct socket *sk)
  {
  	if (sk)
  		udp_tunnel_sock_release(sk);
  }
  
  static void prepare_udp_hdr(struct sk_buff *skb, __be16 src_port,
  			    __be16 dst_port)
  {
  	struct udphdr *udph;
  
  	__skb_push(skb, sizeof(*udph));
  	skb_reset_transport_header(skb);
  	udph = udp_hdr(skb);
  
  	udph->dest = dst_port;
  	udph->source = src_port;
  	udph->len = htons(skb->len);
  	udph->check = 0;
  }
  
  static void prepare_ipv4_hdr(struct dst_entry *dst, struct sk_buff *skb,
  			     __be32 saddr, __be32 daddr, __u8 proto,
  			     __u8 tos, __u8 ttl, __be16 df, bool xnet)
  {
  	struct iphdr *iph;
  
  	skb_scrub_packet(skb, xnet);
  
  	skb_clear_hash(skb);
  	skb_dst_set(skb, dst);
  	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
  
  	skb_push(skb, sizeof(struct iphdr));
  	skb_reset_network_header(skb);
  
  	iph = ip_hdr(skb);
  
  	iph->version	=	IPVERSION;
  	iph->ihl	=	sizeof(struct iphdr) >> 2;
  	iph->frag_off	=	df;
  	iph->protocol	=	proto;
  	iph->tos	=	tos;
  	iph->daddr	=	daddr;
  	iph->saddr	=	saddr;
  	iph->ttl	=	ttl;
  	__ip_select_ident(dev_net(dst->dev), iph,
  			  skb_shinfo(skb)->gso_segs ?: 1);
  	iph->tot_len = htons(skb->len);
  	ip_send_check(iph);
  }
  
  static void prepare_ipv6_hdr(struct dst_entry *dst, struct sk_buff *skb,
  			     struct in6_addr *saddr, struct in6_addr *daddr,
  			     __u8 proto, __u8 prio, __u8 ttl)
  {
  	struct ipv6hdr *ip6h;
  
  	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
  	IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED
  			    | IPSKB_REROUTED);
  	skb_dst_set(skb, dst);
  
  	__skb_push(skb, sizeof(*ip6h));
  	skb_reset_network_header(skb);
  	ip6h		  = ipv6_hdr(skb);
  	ip6_flow_hdr(ip6h, prio, htonl(0));
  	ip6h->payload_len = htons(skb->len);
  	ip6h->nexthdr     = proto;
  	ip6h->hop_limit   = ttl;
  	ip6h->daddr	  = *daddr;
  	ip6h->saddr	  = *saddr;
  	ip6h->payload_len = htons(skb->len - sizeof(*ip6h));
  }
  
  static int prepare4(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
  		    struct sk_buff *skb, struct rxe_av *av)
  {
  	struct dst_entry *dst;
  	bool xnet = false;
  	__be16 df = htons(IP_DF);
  	struct in_addr *saddr = &av->sgid_addr._sockaddr_in.sin_addr;
  	struct in_addr *daddr = &av->dgid_addr._sockaddr_in.sin_addr;
  
  	dst = rxe_find_route4(rxe->ndev, saddr, daddr);
  	if (!dst) {
  		pr_err("Host not reachable\n");
  		return -EHOSTUNREACH;
  	}
  
  	if (!memcmp(saddr, daddr, sizeof(*daddr)))
  		pkt->mask |= RXE_LOOPBACK_MASK;
  
  	prepare_udp_hdr(skb, htons(RXE_ROCE_V2_SPORT),
  			htons(ROCE_V2_UDP_DPORT));
  
  	prepare_ipv4_hdr(dst, skb, saddr->s_addr, daddr->s_addr, IPPROTO_UDP,
  			 av->grh.traffic_class, av->grh.hop_limit, df, xnet);
  	return 0;
  }
  
  static int prepare6(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
  		    struct sk_buff *skb, struct rxe_av *av)
  {
  	struct dst_entry *dst;
  	struct in6_addr *saddr = &av->sgid_addr._sockaddr_in6.sin6_addr;
  	struct in6_addr *daddr = &av->dgid_addr._sockaddr_in6.sin6_addr;
  
  	dst = rxe_find_route6(rxe->ndev, saddr, daddr);
  	if (!dst) {
  		pr_err("Host not reachable\n");
  		return -EHOSTUNREACH;
  	}
  
  	if (!memcmp(saddr, daddr, sizeof(*daddr)))
  		pkt->mask |= RXE_LOOPBACK_MASK;
  
  	prepare_udp_hdr(skb, htons(RXE_ROCE_V2_SPORT),
  			htons(ROCE_V2_UDP_DPORT));
  
  	prepare_ipv6_hdr(dst, skb, saddr, daddr, IPPROTO_UDP,
  			 av->grh.traffic_class,
  			 av->grh.hop_limit);
  	return 0;
  }
  
  static int prepare(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
  		   struct sk_buff *skb, u32 *crc)
  {
  	int err = 0;
  	struct rxe_av *av = rxe_get_av(pkt);
  
  	if (av->network_type == RDMA_NETWORK_IPV4)
  		err = prepare4(rxe, pkt, skb, av);
  	else if (av->network_type == RDMA_NETWORK_IPV6)
  		err = prepare6(rxe, pkt, skb, av);
  
  	*crc = rxe_icrc_hdr(pkt, skb);
  
  	return err;
  }
  
  static void rxe_skb_tx_dtor(struct sk_buff *skb)
  {
  	struct sock *sk = skb->sk;
  	struct rxe_qp *qp = sk->sk_user_data;
  	int skb_out = atomic_dec_return(&qp->skb_out);
  
  	if (unlikely(qp->need_req_skb &&
  		     skb_out < RXE_INFLIGHT_SKBS_PER_QP_LOW))
  		rxe_run_task(&qp->req.task, 1);
  }
  
  static int send(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
  		struct sk_buff *skb)
  {
  	struct sk_buff *nskb;
  	struct rxe_av *av;
  	int err;
  
  	av = rxe_get_av(pkt);
  
  	nskb = skb_clone(skb, GFP_ATOMIC);
  	if (!nskb)
  		return -ENOMEM;
  
  	nskb->destructor = rxe_skb_tx_dtor;
  	nskb->sk = pkt->qp->sk->sk;
  
  	if (av->network_type == RDMA_NETWORK_IPV4) {
  		err = ip_local_out(dev_net(skb_dst(skb)->dev), nskb->sk, nskb);
  	} else if (av->network_type == RDMA_NETWORK_IPV6) {
  		err = ip6_local_out(dev_net(skb_dst(skb)->dev), nskb->sk, nskb);
  	} else {
  		pr_err("Unknown layer 3 protocol: %d\n", av->network_type);
  		kfree_skb(nskb);
  		return -EINVAL;
  	}
  
  	if (unlikely(net_xmit_eval(err))) {
  		pr_debug("error sending packet: %d\n", err);
  		return -EAGAIN;
  	}
  
  	kfree_skb(skb);
  
  	return 0;
  }
  
  static int loopback(struct sk_buff *skb)
  {
  	return rxe_rcv(skb);
  }
  
  static inline int addr_same(struct rxe_dev *rxe, struct rxe_av *av)
  {
  	return rxe->port.port_guid == av->grh.dgid.global.interface_id;
  }
  
  static struct sk_buff *init_packet(struct rxe_dev *rxe, struct rxe_av *av,
  				   int paylen, struct rxe_pkt_info *pkt)
  {
  	unsigned int hdr_len;
  	struct sk_buff *skb;
  
  	if (av->network_type == RDMA_NETWORK_IPV4)
  		hdr_len = ETH_HLEN + sizeof(struct udphdr) +
  			sizeof(struct iphdr);
  	else
  		hdr_len = ETH_HLEN + sizeof(struct udphdr) +
  			sizeof(struct ipv6hdr);
  
  	skb = alloc_skb(paylen + hdr_len + LL_RESERVED_SPACE(rxe->ndev),
  			GFP_ATOMIC);
  	if (unlikely(!skb))
  		return NULL;
  
  	skb_reserve(skb, hdr_len + LL_RESERVED_SPACE(rxe->ndev));
  
  	skb->dev	= rxe->ndev;
  	if (av->network_type == RDMA_NETWORK_IPV4)
  		skb->protocol = htons(ETH_P_IP);
  	else
  		skb->protocol = htons(ETH_P_IPV6);
  
  	pkt->rxe	= rxe;
  	pkt->port_num	= 1;
  	pkt->hdr	= skb_put(skb, paylen);
  	pkt->mask	|= RXE_GRH_MASK;
  
  	memset(pkt->hdr, 0, paylen);
  
  	return skb;
  }
  
  /*
   * this is required by rxe_cfg to match rxe devices in
   * /sys/class/infiniband up with their underlying ethernet devices
   */
  static char *parent_name(struct rxe_dev *rxe, unsigned int port_num)
  {
  	return rxe->ndev->name;
  }
  
  static enum rdma_link_layer link_layer(struct rxe_dev *rxe,
  				       unsigned int port_num)
  {
  	return IB_LINK_LAYER_ETHERNET;
  }
  
  static struct rxe_ifc_ops ifc_ops = {
  	.node_guid	= node_guid,
  	.port_guid	= port_guid,
  	.dma_device	= dma_device,
  	.mcast_add	= mcast_add,
  	.mcast_delete	= mcast_delete,
  	.prepare	= prepare,
  	.send		= send,
  	.loopback	= loopback,
  	.init_packet	= init_packet,
  	.parent_name	= parent_name,
  	.link_layer	= link_layer,
  };
  
  struct rxe_dev *rxe_net_add(struct net_device *ndev)
  {
  	int err;
  	struct rxe_dev *rxe = NULL;
  
  	rxe = (struct rxe_dev *)ib_alloc_device(sizeof(*rxe));
  	if (!rxe)
  		return NULL;
  
  	rxe->ifc_ops = &ifc_ops;
  	rxe->ndev = ndev;
  
  	err = rxe_add(rxe, ndev->mtu);
  	if (err) {
  		ib_dealloc_device(&rxe->ib_dev);
  		return NULL;
  	}
  
  	spin_lock_bh(&dev_list_lock);
  	list_add_tail(&rxe->list, &rxe_dev_list);
  	spin_unlock_bh(&dev_list_lock);
  	return rxe;
  }
  
  void rxe_remove_all(void)
  {
  	spin_lock_bh(&dev_list_lock);
  	while (!list_empty(&rxe_dev_list)) {
  		struct rxe_dev *rxe =
  			list_first_entry(&rxe_dev_list, struct rxe_dev, list);
  
  		list_del(&rxe->list);
  		spin_unlock_bh(&dev_list_lock);
  		rxe_remove(rxe);
  		spin_lock_bh(&dev_list_lock);
  	}
  	spin_unlock_bh(&dev_list_lock);
  }
  EXPORT_SYMBOL(rxe_remove_all);
  
  static void rxe_port_event(struct rxe_dev *rxe,
  			   enum ib_event_type event)
  {
  	struct ib_event ev;
  
  	ev.device = &rxe->ib_dev;
  	ev.element.port_num = 1;
  	ev.event = event;
  
  	ib_dispatch_event(&ev);
  }
  
  /* Caller must hold net_info_lock */
  void rxe_port_up(struct rxe_dev *rxe)
  {
  	struct rxe_port *port;
  
  	port = &rxe->port;
  	port->attr.state = IB_PORT_ACTIVE;
  	port->attr.phys_state = IB_PHYS_STATE_LINK_UP;
  
  	rxe_port_event(rxe, IB_EVENT_PORT_ACTIVE);
  	pr_info("set %s active\n", rxe->ib_dev.name);
  }
  
  /* Caller must hold net_info_lock */
  void rxe_port_down(struct rxe_dev *rxe)
  {
  	struct rxe_port *port;
  
  	port = &rxe->port;
  	port->attr.state = IB_PORT_DOWN;
  	port->attr.phys_state = IB_PHYS_STATE_LINK_DOWN;
  
  	rxe_port_event(rxe, IB_EVENT_PORT_ERR);
  	pr_info("set %s down\n", rxe->ib_dev.name);
  }
  
  static int rxe_notify(struct notifier_block *not_blk,
  		      unsigned long event,
  		      void *arg)
  {
  	struct net_device *ndev = netdev_notifier_info_to_dev(arg);
  	struct rxe_dev *rxe = net_to_rxe(ndev);
  
  	if (!rxe)
  		goto out;
  
  	switch (event) {
  	case NETDEV_UNREGISTER:
  		list_del(&rxe->list);
  		rxe_remove(rxe);
  		break;
  	case NETDEV_UP:
  		rxe_port_up(rxe);
  		break;
  	case NETDEV_DOWN:
  		rxe_port_down(rxe);
  		break;
  	case NETDEV_CHANGEMTU:
  		pr_info("%s changed mtu to %d\n", ndev->name, ndev->mtu);
  		rxe_set_mtu(rxe, ndev->mtu);
  		break;
  	case NETDEV_REBOOT:
  	case NETDEV_CHANGE:
  	case NETDEV_GOING_DOWN:
  	case NETDEV_CHANGEADDR:
  	case NETDEV_CHANGENAME:
  	case NETDEV_FEAT_CHANGE:
  	default:
  		pr_info("ignoring netdev event = %ld for %s\n",
  			event, ndev->name);
  		break;
  	}
  out:
  	return NOTIFY_OK;
  }
  
  struct notifier_block rxe_net_notifier = {
  	.notifier_call = rxe_notify,
  };
  
  int rxe_net_ipv4_init(void)
  {
  	spin_lock_init(&dev_list_lock);
  
  	recv_sockets.sk4 = rxe_setup_udp_tunnel(&init_net,
  				htons(ROCE_V2_UDP_DPORT), false);
  	if (IS_ERR(recv_sockets.sk4)) {
  		recv_sockets.sk4 = NULL;
  		pr_err("Failed to create IPv4 UDP tunnel\n");
  		return -1;
  	}
  
  	return 0;
  }
  
  int rxe_net_ipv6_init(void)
  {
  #if IS_ENABLED(CONFIG_IPV6)
  
  	spin_lock_init(&dev_list_lock);
  
  	recv_sockets.sk6 = rxe_setup_udp_tunnel(&init_net,
  						htons(ROCE_V2_UDP_DPORT), true);
  	if (IS_ERR(recv_sockets.sk6)) {
  		recv_sockets.sk6 = NULL;
  		pr_err("Failed to create IPv6 UDP tunnel\n");
  		return -1;
  	}
  #endif
  	return 0;
  }
  
  void rxe_net_exit(void)
  {
  	rxe_release_udp_tunnel(recv_sockets.sk6);
  	rxe_release_udp_tunnel(recv_sockets.sk4);
  	unregister_netdevice_notifier(&rxe_net_notifier);
  }
  
  int rxe_net_init(void)
  {
  	int err;
  
  	recv_sockets.sk6 = NULL;
  
  	err = rxe_net_ipv4_init();
  	if (err)
  		return err;
  	err = rxe_net_ipv6_init();
  	if (err)
  		goto err_out;
  	err = register_netdevice_notifier(&rxe_net_notifier);
  	if (err) {
  		pr_err("Failed to register netdev notifier\n");
  		goto err_out;
  	}
  	return 0;
  err_out:
  	rxe_net_exit();
  	return err;
  }
  