rxe_net.c

/*
 * Copyright (c) 2009-2011 Mellanox Technologies Ltd. All rights reserved.
 * Copyright (c) 2009-2011 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 <net/ip6_tunnel.h>

#include "rxe.h"
#include "rxe_net.h"
#include "rxe_loc.h"

/*
 * note: this table is a replacement for a protocol specific pointer
 * in struct net_device which exists for other ethertypes
 * this allows us to not have to patch that data structure
 * eventually we want to get our own when we're famous
 */
struct rxe_net_info net_info[RXE_MAX_IF_INDEX];
spinlock_t net_info_lock; /* spinlock for net_info array */

struct rxe_addr_info addr_info;


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;
}

/* callback when rxe gets released */
static void release(struct rxe_dev *rxe)
{
	module_put(THIS_MODULE);
}

static __be64 node_guid(struct rxe_dev *rxe)
{
	return rxe_mac_to_eui64(rxe->ndev);
}

static __be64 port_guid(struct rxe_dev *rxe, unsigned int port_num)
{
	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];

	// parse if ipv4 address or ipv6 address
	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 rtable *rxe_find_route4(struct in_addr *saddr,
				      struct in_addr *daddr)
{
	struct rtable *rt;
	struct flowi4 fl = { { 0 } };

	memset(&fl, 0, sizeof(fl));
	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("no route to %pI4\n", &daddr->s_addr);
		return NULL;
	}

	return rt;
}

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;

	if (unlikely(ipv6_stub->ipv6_dst_lookup(addr_info.sock6->sk, &ndst,
						&fl6))) {
		pr_err("no route to %pI6\n", daddr);
		goto put;
	}

	if (unlikely(ndst->error)) {
		pr_err("no route to %pI6\n", daddr);
		goto put;
	}

	return ndst;
put:
	dst_release(ndst);
	return NULL;
}

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 = net_to_port(ndev);
	pkt->hdr = (u8 *)(udph + 1);
//	pkt->mask = RXE_GRH_MASK;   // GRH header is no longer present in a rocev2 packet
	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, bool ipv6,
					   __be16 port)
{
	int err;
	struct socket *sock;
	struct udp_port_cfg udp_cfg;
	struct udp_tunnel_sock_cfg tnl_cfg;

	memset(&udp_cfg, 0, sizeof(udp_cfg));

	if (ipv6) {
		udp_cfg.family = AF_INET6;
		udp_cfg.reuse_port = true;
	} else {
		udp_cfg.family = AF_INET;
		udp_cfg.reuse_port = true;
		udp_cfg.local_ip.s_addr = htonl(INADDR_ANY);
	}

	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.sk_user_data = NULL;
	tnl_cfg.encap_type = 1;
	tnl_cfg.encap_rcv = rxe_udp_encap_recv;
	tnl_cfg.encap_destroy = NULL;

	/* Setup UDP tunnel */
	setup_udp_tunnel_sock(net, sock, &tnl_cfg);

	return sock;
}

static void rxe_release_udp_tunnel(struct socket *sk)
{
	udp_tunnel_sock_release(sk);
}

static struct rxe_av *get_av(struct rxe_pkt_info *pkt)
{
	if (qp_type(pkt->qp) == IB_QPT_RC || qp_type(pkt->qp) == IB_QPT_UC)
		return &pkt->qp->pri_av;

	return &pkt->wqe->av;
}

int prepare(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
	    struct sk_buff *skb)
{
	int sent_bytes = 0;
	bool csum_nocheck = true;
	struct rxe_av *av;
	struct iphdr *iph;

	av = get_av(pkt);

	if (av->network_type == RDMA_NETWORK_IPV4) {
		__be16 df = htons(IP_DF);
		bool xnet = false;
		struct in_addr *saddr = &av->sgid_addr._sockaddr_in.sin_addr;
		struct in_addr *daddr = &av->dgid_addr._sockaddr_in.sin_addr;
		struct rtable *rt = rxe_find_route4(saddr, daddr);

		if (!rt) {
			pr_err("Host not reachable\n");
			return -EHOSTUNREACH;
		}

		udp_tunnel_prepare_skb(rt, skb, saddr->s_addr,
				       daddr->s_addr,
				       av->grh.traffic_class,
				       av->grh.hop_limit,
				       df, htons(0xc000),
				       htons(ROCE_V2_UDP_DPORT),
				       xnet,
				       csum_nocheck);

		sent_bytes = skb->len;
		iptunnel_prepare(rt, skb, saddr->s_addr,
				 daddr->s_addr, IPPROTO_UDP,
				 av->grh.traffic_class,
				 av->grh.hop_limit, df, xnet);

		iph = ip_hdr(skb);
		iph->tot_len = htons(skb->len);
		ip_send_check(iph);

	} else if (av->network_type == RDMA_NETWORK_IPV6) {
		struct in6_addr *saddr = &av->sgid_addr._sockaddr_in6.sin6_addr;
		struct in6_addr *daddr = &av->dgid_addr._sockaddr_in6.sin6_addr;
		struct dst_entry *dst = rxe_find_route6(rxe->ndev,
							saddr, daddr);

		if (!dst) {
			pr_err("Host not reachable\n");
			return -EHOSTUNREACH;
		}

		udp_tunnel6_prepare_skb(dst, skb, rxe->ndev,
					saddr, daddr,
					av->grh.traffic_class,
					av->grh.hop_limit,
					htons(0xc000),
					htons(ROCE_V2_UDP_DPORT),
					csum_nocheck);

		ip6_set_len(skb);
	}
	return 0;
}

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 sent_bytes;
	int err;

	av = 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;

	sent_bytes = nskb->len;
	if (av->network_type == RDMA_NETWORK_IPV4) {
		err = ip_local_out_sk(nskb->sk, nskb);
	} else if (av->network_type == RDMA_NETWORK_IPV6) {
		err = ip6_local_out_sk(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)
{
	int port_num = 1;

	return rxe->port[port_num - 1].guid_tbl[0]
			== 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;

	if (addr_same(rxe, av))
		pkt->mask |= RXE_LOOPBACK_MASK;

	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 = {
	.release	= release,
	.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,
};

/* Caller must hold net_info_lock */
void rxe_net_add(struct net_device *ndev)
{
	int err;
	struct rxe_dev *rxe;
	unsigned port_num;

	__module_get(THIS_MODULE);

	rxe = (struct rxe_dev *)ib_alloc_device(sizeof(*rxe));
	if (!rxe) {
		err = -ENOMEM;
		goto err1;
	}

	/* for now we always assign port = 1 */
	port_num = 1;

	rxe->ifc_ops = &ifc_ops;

	rxe->ndev = ndev;

	err = rxe_add(rxe, ndev->mtu);
	if (err)
		goto err2;

	pr_info("rxe: added %s to %s\n",
		rxe->ib_dev.name, ndev->name);

	net_info[ndev->ifindex].rxe = rxe;
	net_info[ndev->ifindex].port = port_num;
	net_info[ndev->ifindex].ndev = ndev;
	return;

err2:
	ib_dealloc_device(&rxe->ib_dev);
err1:
	module_put(THIS_MODULE);
}

/* Caller must hold net_info_lock */
void rxe_net_up(struct net_device *ndev)
{
	struct rxe_dev *rxe;
	struct rxe_port *port;
	u8 port_num;

	if (ndev->ifindex >= RXE_MAX_IF_INDEX)
		goto out;

	net_info[ndev->ifindex].status = IB_PORT_ACTIVE;

	rxe = net_to_rxe(ndev);
	if (!rxe)
		goto out;

	port_num = net_to_port(ndev);
	port = &rxe->port[port_num-1];
	port->attr.state = IB_PORT_ACTIVE;
	port->attr.phys_state = IB_PHYS_STATE_LINK_UP;

	pr_info("rxe: set %s active for %s\n",
		rxe->ib_dev.name, ndev->name);
out:
	return;
}

/* Caller must hold net_info_lock */
void rxe_net_down(struct net_device *ndev)
{
	struct rxe_dev *rxe;
	struct rxe_port *port;
	u8 port_num;

	if (ndev->ifindex >= RXE_MAX_IF_INDEX)
		goto out;

	net_info[ndev->ifindex].status = IB_PORT_DOWN;

	rxe = net_to_rxe(ndev);
	if (!rxe)
		goto out;

	port_num = net_to_port(ndev);
	port = &rxe->port[port_num-1];
	port->attr.state = IB_PORT_DOWN;
	port->attr.phys_state = 3;

	pr_info("rxe: set %s down for %s\n",
		rxe->ib_dev.name, ndev->name);
out:
	return;
}

static int can_support_rxe(struct net_device *ndev)
{
	int rc = 0;

	if (ndev->ifindex >= RXE_MAX_IF_INDEX) {
		pr_debug("%s index %d: too large for rxe ndev table\n",
			 ndev->name, ndev->ifindex);
		goto out;
	}

	/* Let's says we support all ethX devices */
	if (ndev->type == ARPHRD_ETHER)
		rc = 1;

out:
	return rc;
}

static int rxe_notify(struct notifier_block *not_blk,
		      unsigned long event,
		      void *arg)
{
	struct rxe_dev *rxe;
	struct net_device *ndev = netdev_notifier_info_to_dev(arg);

	if (!can_support_rxe(ndev))
		goto out;

	spin_lock_bh(&net_info_lock);
	switch (event) {
	case NETDEV_REGISTER:
		/* Keep a record of this NIC. */
		net_info[ndev->ifindex].status = IB_PORT_DOWN;
		net_info[ndev->ifindex].rxe = NULL;
		net_info[ndev->ifindex].port = 1;
		net_info[ndev->ifindex].ndev = ndev;
		break;

	case NETDEV_UNREGISTER:
		if (net_info[ndev->ifindex].rxe) {
			rxe = net_info[ndev->ifindex].rxe;
			net_info[ndev->ifindex].rxe = NULL;
			spin_unlock_bh(&net_info_lock);
			rxe_remove(rxe);
			spin_lock_bh(&net_info_lock);
		}
		net_info[ndev->ifindex].status = 0;
		net_info[ndev->ifindex].port = 0;
		net_info[ndev->ifindex].ndev = NULL;
		break;

	case NETDEV_UP:
		rxe_net_up(ndev);
		break;

	case NETDEV_DOWN:
		rxe_net_down(ndev);
		break;

	case NETDEV_CHANGEMTU:
		rxe = net_to_rxe(ndev);
		if (rxe) {
			pr_info("rxe: %s changed mtu to %d\n",
				ndev->name, ndev->mtu);
			rxe_set_mtu(rxe, ndev->mtu, net_to_port(ndev));
		}
		break;

	case NETDEV_REBOOT:
	case NETDEV_CHANGE:
	case NETDEV_GOING_DOWN:
	case NETDEV_CHANGEADDR:
	case NETDEV_CHANGENAME:
	case NETDEV_FEAT_CHANGE:
	default:
		pr_info("rxe: ignoring netdev event = %ld for %s\n",
			event, ndev->name);
		break;
	}
	spin_unlock_bh(&net_info_lock);

out:
	return NOTIFY_OK;
}

static struct notifier_block rxe_net_notifier = {
	.notifier_call = rxe_notify,
};

int rxe_net_init(void)
{
	int err;

	spin_lock_init(&net_info_lock);

	addr_info.sock4 = rxe_setup_udp_tunnel(&init_net, 0,
					       htons(ROCE_V2_UDP_DPORT));
	if (IS_ERR(addr_info.sock4)) {
		addr_info.sock4 = NULL;
		pr_err("rxe: Failed to create IPv4 UDP tunnel\n");
		return -1;
	}

	addr_info.sock6 = rxe_setup_udp_tunnel(&init_net, 1,
					       htons(ROCE_V2_UDP_DPORT));
	if (IS_ERR(addr_info.sock6)) {
		addr_info.sock6 = NULL;
		rxe_release_udp_tunnel(addr_info.sock4);
		pr_err("rxe_net: Failed to create IPv6 UDP tunnel\n");
		return -1;
	}

	err = register_netdevice_notifier(&rxe_net_notifier);

	return err;
}

void rxe_net_exit(void)
{
	if (addr_info.sock6)
		rxe_release_udp_tunnel(addr_info.sock6);
	if (addr_info.sock4)
		rxe_release_udp_tunnel(addr_info.sock4);

	unregister_netdevice_notifier(&rxe_net_notifier);
}