drivers/infiniband/sw/rxe/rxe_recv.c - third_party/linux - Git at Google

 /*
  * 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 "rxe.h"
 #include "rxe_loc.h"

 static int check_type_state(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
 			    struct rxe_qp *qp)
 {
 	if (unlikely(!qp->valid))
 		goto err1;

 	switch (qp_type(qp)) {
 	case IB_QPT_RC:
 		if (unlikely((pkt->opcode & IB_OPCODE_RC) != 0)) {
 			pr_warn_ratelimited("bad qp type\n");
 			goto err1;
 		}
 		break;
 	case IB_QPT_UC:
 		if (unlikely(!(pkt->opcode & IB_OPCODE_UC))) {
 			pr_warn_ratelimited("bad qp type\n");
 			goto err1;
 		}
 		break;
 	case IB_QPT_UD:
 	case IB_QPT_SMI:
 	case IB_QPT_GSI:
 		if (unlikely(!(pkt->opcode & IB_OPCODE_UD))) {
 			pr_warn_ratelimited("bad qp type\n");
 			goto err1;
 		}
 		break;
 	default:
 		pr_warn_ratelimited("unsupported qp type\n");
 		goto err1;
 	}

 	if (pkt->mask & RXE_REQ_MASK) {
 		if (unlikely(qp->resp.state != QP_STATE_READY))
 			goto err1;
 	} else if (unlikely(qp->req.state < QP_STATE_READY ||
 				qp->req.state > QP_STATE_DRAINED)) {
 		goto err1;
 	}

 	return 0;

 err1:
 	return -EINVAL;
 }

 static void set_bad_pkey_cntr(struct rxe_port *port)
 {
 	spin_lock_bh(&port->port_lock);
 	port->attr.bad_pkey_cntr = min((u32)0xffff,
 				       port->attr.bad_pkey_cntr + 1);
 	spin_unlock_bh(&port->port_lock);
 }

 static void set_qkey_viol_cntr(struct rxe_port *port)
 {
 	spin_lock_bh(&port->port_lock);
 	port->attr.qkey_viol_cntr = min((u32)0xffff,
 					port->attr.qkey_viol_cntr + 1);
 	spin_unlock_bh(&port->port_lock);
 }

 static int check_keys(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
 		      u32 qpn, struct rxe_qp *qp)
 {
 	int i;
 	int found_pkey = 0;
 	struct rxe_port *port = &rxe->port;
 	u16 pkey = bth_pkey(pkt);

 	pkt->pkey_index = 0;

 	if (qpn == 1) {
 		for (i = 0; i < port->attr.pkey_tbl_len; i++) {
 			if (pkey_match(pkey, port->pkey_tbl[i])) {
 				pkt->pkey_index = i;
 				found_pkey = 1;
 				break;
 			}
 		}

 		if (!found_pkey) {
 			pr_warn_ratelimited("bad pkey = 0x%x\n", pkey);
 			set_bad_pkey_cntr(port);
 			goto err1;
 		}
 	} else if (qpn != 0) {
 		if (unlikely(!pkey_match(pkey,
 					 port->pkey_tbl[qp->attr.pkey_index]
 					))) {
 			pr_warn_ratelimited("bad pkey = 0x%0x\n", pkey);
 			set_bad_pkey_cntr(port);
 			goto err1;
 		}
 		pkt->pkey_index = qp->attr.pkey_index;
 	}

 	if ((qp_type(qp) == IB_QPT_UD || qp_type(qp) == IB_QPT_GSI) &&
 	    qpn != 0 && pkt->mask) {
 		u32 qkey = (qpn == 1) ? GSI_QKEY : qp->attr.qkey;

 		if (unlikely(deth_qkey(pkt) != qkey)) {
 			pr_warn_ratelimited("bad qkey, got 0x%x expected 0x%x for qpn 0x%x\n",
 					    deth_qkey(pkt), qkey, qpn);
 			set_qkey_viol_cntr(port);
 			goto err1;
 		}
 	}

 	return 0;

 err1:
 	return -EINVAL;
 }

 static int check_addr(struct rxe_dev *rxe, struct rxe_pkt_info *pkt,
 		      struct rxe_qp *qp)
 {
 	struct sk_buff *skb = PKT_TO_SKB(pkt);

 	if (qp_type(qp) != IB_QPT_RC && qp_type(qp) != IB_QPT_UC)
 		goto done;

 	if (unlikely(pkt->port_num != qp->attr.port_num)) {
 		pr_warn_ratelimited("port %d != qp port %d\n",
 				    pkt->port_num, qp->attr.port_num);
 		goto err1;
 	}

 	if (skb->protocol == htons(ETH_P_IP)) {
 		struct in_addr *saddr =
 			&qp->pri_av.sgid_addr._sockaddr_in.sin_addr;
 		struct in_addr *daddr =
 			&qp->pri_av.dgid_addr._sockaddr_in.sin_addr;

 		if (ip_hdr(skb)->daddr != saddr->s_addr) {
 			pr_warn_ratelimited("dst addr %pI4 != qp source addr %pI4\n",
 					    &ip_hdr(skb)->daddr,
 					    &saddr->s_addr);
 			goto err1;
 		}

 		if (ip_hdr(skb)->saddr != daddr->s_addr) {
 			pr_warn_ratelimited("source addr %pI4 != qp dst addr %pI4\n",
 					    &ip_hdr(skb)->saddr,
 					    &daddr->s_addr);
 			goto err1;
 		}

 	} else if (skb->protocol == htons(ETH_P_IPV6)) {
 		struct in6_addr *saddr =
 			&qp->pri_av.sgid_addr._sockaddr_in6.sin6_addr;
 		struct in6_addr *daddr =
 			&qp->pri_av.dgid_addr._sockaddr_in6.sin6_addr;

 		if (memcmp(&ipv6_hdr(skb)->daddr, saddr, sizeof(*saddr))) {
 			pr_warn_ratelimited("dst addr %pI6 != qp source addr %pI6\n",
 					    &ipv6_hdr(skb)->daddr, saddr);
 			goto err1;
 		}

 		if (memcmp(&ipv6_hdr(skb)->saddr, daddr, sizeof(*daddr))) {
 			pr_warn_ratelimited("source addr %pI6 != qp dst addr %pI6\n",
 					    &ipv6_hdr(skb)->saddr, daddr);
 			goto err1;
 		}
 	}

 done:
 	return 0;

 err1:
 	return -EINVAL;
 }

 static int hdr_check(struct rxe_pkt_info *pkt)
 {
 	struct rxe_dev *rxe = pkt->rxe;
 	struct rxe_port *port = &rxe->port;
 	struct rxe_qp *qp = NULL;
 	u32 qpn = bth_qpn(pkt);
 	int index;
 	int err;

 	if (unlikely(bth_tver(pkt) != BTH_TVER)) {
 		pr_warn_ratelimited("bad tver\n");
 		goto err1;
 	}

 	if (qpn != IB_MULTICAST_QPN) {
 		index = (qpn == 0) ? port->qp_smi_index :
 			((qpn == 1) ? port->qp_gsi_index : qpn);
 		qp = rxe_pool_get_index(&rxe->qp_pool, index);
 		if (unlikely(!qp)) {
 			pr_warn_ratelimited("no qp matches qpn 0x%x\n", qpn);
 			goto err1;
 		}

 		err = check_type_state(rxe, pkt, qp);
 		if (unlikely(err))
 			goto err2;

 		err = check_addr(rxe, pkt, qp);
 		if (unlikely(err))
 			goto err2;

 		err = check_keys(rxe, pkt, qpn, qp);
 		if (unlikely(err))
 			goto err2;
 	} else {
 		if (unlikely((pkt->mask & RXE_GRH_MASK) == 0)) {
 			pr_warn_ratelimited("no grh for mcast qpn\n");
 			goto err1;
 		}
 	}

 	pkt->qp = qp;
 	return 0;

 err2:
 	if (qp)
 		rxe_drop_ref(qp);
 err1:
 	return -EINVAL;
 }

 static inline void rxe_rcv_pkt(struct rxe_dev *rxe,
 			       struct rxe_pkt_info *pkt,
 			       struct sk_buff *skb)
 {
 	if (pkt->mask & RXE_REQ_MASK)
 		rxe_resp_queue_pkt(rxe, pkt->qp, skb);
 	else
 		rxe_comp_queue_pkt(rxe, pkt->qp, skb);
 }

 static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb)
 {
 	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
 	struct rxe_mc_grp *mcg;
 	struct rxe_mc_elem *mce;
 	struct rxe_qp *qp;
 	union ib_gid dgid;
 	int err;

 	if (skb->protocol == htons(ETH_P_IP))
 		ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 				       (struct in6_addr *)&dgid);
 	else if (skb->protocol == htons(ETH_P_IPV6))
 		memcpy(&dgid, &ipv6_hdr(skb)->daddr, sizeof(dgid));

 	/* lookup mcast group corresponding to mgid, takes a ref */
 	mcg = rxe_pool_get_key(&rxe->mc_grp_pool, &dgid);
 	if (!mcg)
 		goto err1;	/* mcast group not registered */

 	spin_lock_bh(&mcg->mcg_lock);

 	list_for_each_entry(mce, &mcg->qp_list, qp_list) {
 		qp = mce->qp;
 		pkt = SKB_TO_PKT(skb);

 		/* validate qp for incoming packet */
 		err = check_type_state(rxe, pkt, qp);
 		if (err)
 			continue;

 		err = check_keys(rxe, pkt, bth_qpn(pkt), qp);
 		if (err)
 			continue;

 		/* if *not* the last qp in the list
 		 * increase the users of the skb then post to the next qp
 		 */
 		if (mce->qp_list.next != &mcg->qp_list)
 			skb_get(skb);

 		pkt->qp = qp;
 		rxe_add_ref(qp);
 		rxe_rcv_pkt(rxe, pkt, skb);
 	}

 	spin_unlock_bh(&mcg->mcg_lock);

 	rxe_drop_ref(mcg);	/* drop ref from rxe_pool_get_key. */

 err1:
 	kfree_skb(skb);
 }

 static int rxe_match_dgid(struct rxe_dev *rxe, struct sk_buff *skb)
 {
 	union ib_gid dgid;
 	union ib_gid *pdgid;

 	if (skb->protocol == htons(ETH_P_IP)) {
 		ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 				       (struct in6_addr *)&dgid);
 		pdgid = &dgid;
 	} else {
 		pdgid = (union ib_gid *)&ipv6_hdr(skb)->daddr;
 	}

 	return ib_find_cached_gid_by_port(&rxe->ib_dev, pdgid,
 					  IB_GID_TYPE_ROCE_UDP_ENCAP,
 					  1, skb->dev, NULL);
 }

 /* rxe_rcv is called from the interface driver */
 void rxe_rcv(struct sk_buff *skb)
 {
 	int err;
 	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
 	struct rxe_dev *rxe = pkt->rxe;
 	__be32 *icrcp;
 	u32 calc_icrc, pack_icrc;

 	pkt->offset = 0;

 	if (unlikely(skb->len < pkt->offset + RXE_BTH_BYTES))
 		goto drop;

 	if (unlikely(rxe_match_dgid(rxe, skb) < 0)) {
 		pr_warn_ratelimited("failed matching dgid\n");
 		goto drop;
 	}

 	pkt->opcode = bth_opcode(pkt);
 	pkt->psn = bth_psn(pkt);
 	pkt->qp = NULL;
 	pkt->mask |= rxe_opcode[pkt->opcode].mask;

 	if (unlikely(skb->len < header_size(pkt)))
 		goto drop;

 	err = hdr_check(pkt);
 	if (unlikely(err))
 		goto drop;

 	/* Verify ICRC */
 	icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE);
 	pack_icrc = be32_to_cpu(*icrcp);

 	calc_icrc = rxe_icrc_hdr(pkt, skb);
 	calc_icrc = rxe_crc32(rxe, calc_icrc, (u8 *)payload_addr(pkt),
 			      payload_size(pkt));
 	calc_icrc = (__force u32)cpu_to_be32(~calc_icrc);
 	if (unlikely(calc_icrc != pack_icrc)) {
 		if (skb->protocol == htons(ETH_P_IPV6))
 			pr_warn_ratelimited("bad ICRC from %pI6c\n",
 					    &ipv6_hdr(skb)->saddr);
 		else if (skb->protocol == htons(ETH_P_IP))
 			pr_warn_ratelimited("bad ICRC from %pI4\n",
 					    &ip_hdr(skb)->saddr);
 		else
 			pr_warn_ratelimited("bad ICRC from unknown\n");

 		goto drop;
 	}

 	rxe_counter_inc(rxe, RXE_CNT_RCVD_PKTS);

 	if (unlikely(bth_qpn(pkt) == IB_MULTICAST_QPN))
 		rxe_rcv_mcast_pkt(rxe, skb);
 	else
 		rxe_rcv_pkt(rxe, pkt, skb);

 	return;

 drop:
 	if (pkt->qp)
 		rxe_drop_ref(pkt->qp);

 	kfree_skb(skb);
 }
	/*
	* 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 "rxe.h"
	#include "rxe_loc.h"

	static int check_type_state(struct rxe_dev rxe, struct rxe_pkt_info pkt,
	struct rxe_qp *qp)
	{
	if (unlikely(!qp->valid))
	goto err1;

	switch (qp_type(qp)) {
	case IB_QPT_RC:
	if (unlikely((pkt->opcode & IB_OPCODE_RC) != 0)) {
	pr_warn_ratelimited("bad qp type\n");
	goto err1;
	}
	break;
	case IB_QPT_UC:
	if (unlikely(!(pkt->opcode & IB_OPCODE_UC))) {
	pr_warn_ratelimited("bad qp type\n");
	goto err1;
	}
	break;
	case IB_QPT_UD:
	case IB_QPT_SMI:
	case IB_QPT_GSI:
	if (unlikely(!(pkt->opcode & IB_OPCODE_UD))) {
	pr_warn_ratelimited("bad qp type\n");
	goto err1;
	}
	break;
	default:
	pr_warn_ratelimited("unsupported qp type\n");
	goto err1;
	}

	if (pkt->mask & RXE_REQ_MASK) {
	if (unlikely(qp->resp.state != QP_STATE_READY))
	goto err1;
	} else if (unlikely(qp->req.state < QP_STATE_READY \|\|
	qp->req.state > QP_STATE_DRAINED)) {
	goto err1;
	}

	return 0;

	err1:
	return -EINVAL;
	}

	static void set_bad_pkey_cntr(struct rxe_port *port)
	{
	spin_lock_bh(&port->port_lock);
	port->attr.bad_pkey_cntr = min((u32)0xffff,
	port->attr.bad_pkey_cntr + 1);
	spin_unlock_bh(&port->port_lock);
	}

	static void set_qkey_viol_cntr(struct rxe_port *port)
	{
	spin_lock_bh(&port->port_lock);
	port->attr.qkey_viol_cntr = min((u32)0xffff,
	port->attr.qkey_viol_cntr + 1);
	spin_unlock_bh(&port->port_lock);
	}

	static int check_keys(struct rxe_dev rxe, struct rxe_pkt_info pkt,
	u32 qpn, struct rxe_qp *qp)
	{
	int i;
	int found_pkey = 0;
	struct rxe_port *port = &rxe->port;
	u16 pkey = bth_pkey(pkt);

	pkt->pkey_index = 0;

	if (qpn == 1) {
	for (i = 0; i < port->attr.pkey_tbl_len; i++) {
	if (pkey_match(pkey, port->pkey_tbl[i])) {
	pkt->pkey_index = i;
	found_pkey = 1;
	break;
	}
	}

	if (!found_pkey) {
	pr_warn_ratelimited("bad pkey = 0x%x\n", pkey);
	set_bad_pkey_cntr(port);
	goto err1;
	}
	} else if (qpn != 0) {
	if (unlikely(!pkey_match(pkey,
	port->pkey_tbl[qp->attr.pkey_index]
	))) {
	pr_warn_ratelimited("bad pkey = 0x%0x\n", pkey);
	set_bad_pkey_cntr(port);
	goto err1;
	}
	pkt->pkey_index = qp->attr.pkey_index;
	}

	if ((qp_type(qp) == IB_QPT_UD \|\| qp_type(qp) == IB_QPT_GSI) &&
	qpn != 0 && pkt->mask) {
	u32 qkey = (qpn == 1) ? GSI_QKEY : qp->attr.qkey;

	if (unlikely(deth_qkey(pkt) != qkey)) {
	pr_warn_ratelimited("bad qkey, got 0x%x expected 0x%x for qpn 0x%x\n",
	deth_qkey(pkt), qkey, qpn);
	set_qkey_viol_cntr(port);
	goto err1;
	}
	}

	return 0;

	err1:
	return -EINVAL;
	}

	static int check_addr(struct rxe_dev rxe, struct rxe_pkt_info pkt,
	struct rxe_qp *qp)
	{
	struct sk_buff *skb = PKT_TO_SKB(pkt);

	if (qp_type(qp) != IB_QPT_RC && qp_type(qp) != IB_QPT_UC)
	goto done;

	if (unlikely(pkt->port_num != qp->attr.port_num)) {
	pr_warn_ratelimited("port %d != qp port %d\n",
	pkt->port_num, qp->attr.port_num);
	goto err1;
	}

	if (skb->protocol == htons(ETH_P_IP)) {
	struct in_addr *saddr =
	&qp->pri_av.sgid_addr._sockaddr_in.sin_addr;
	struct in_addr *daddr =
	&qp->pri_av.dgid_addr._sockaddr_in.sin_addr;

	if (ip_hdr(skb)->daddr != saddr->s_addr) {
	pr_warn_ratelimited("dst addr %pI4 != qp source addr %pI4\n",
	&ip_hdr(skb)->daddr,
	&saddr->s_addr);
	goto err1;
	}

	if (ip_hdr(skb)->saddr != daddr->s_addr) {
	pr_warn_ratelimited("source addr %pI4 != qp dst addr %pI4\n",
	&ip_hdr(skb)->saddr,
	&daddr->s_addr);
	goto err1;
	}

	} else if (skb->protocol == htons(ETH_P_IPV6)) {
	struct in6_addr *saddr =
	&qp->pri_av.sgid_addr._sockaddr_in6.sin6_addr;
	struct in6_addr *daddr =
	&qp->pri_av.dgid_addr._sockaddr_in6.sin6_addr;

	if (memcmp(&ipv6_hdr(skb)->daddr, saddr, sizeof(*saddr))) {
	pr_warn_ratelimited("dst addr %pI6 != qp source addr %pI6\n",
	&ipv6_hdr(skb)->daddr, saddr);
	goto err1;
	}

	if (memcmp(&ipv6_hdr(skb)->saddr, daddr, sizeof(*daddr))) {
	pr_warn_ratelimited("source addr %pI6 != qp dst addr %pI6\n",
	&ipv6_hdr(skb)->saddr, daddr);
	goto err1;
	}
	}

	done:
	return 0;

	err1:
	return -EINVAL;
	}

	static int hdr_check(struct rxe_pkt_info *pkt)
	{
	struct rxe_dev *rxe = pkt->rxe;
	struct rxe_port *port = &rxe->port;
	struct rxe_qp *qp = NULL;
	u32 qpn = bth_qpn(pkt);
	int index;
	int err;

	if (unlikely(bth_tver(pkt) != BTH_TVER)) {
	pr_warn_ratelimited("bad tver\n");
	goto err1;
	}

	if (qpn != IB_MULTICAST_QPN) {
	index = (qpn == 0) ? port->qp_smi_index :
	((qpn == 1) ? port->qp_gsi_index : qpn);
	qp = rxe_pool_get_index(&rxe->qp_pool, index);
	if (unlikely(!qp)) {
	pr_warn_ratelimited("no qp matches qpn 0x%x\n", qpn);
	goto err1;
	}

	err = check_type_state(rxe, pkt, qp);
	if (unlikely(err))
	goto err2;

	err = check_addr(rxe, pkt, qp);
	if (unlikely(err))
	goto err2;

	err = check_keys(rxe, pkt, qpn, qp);
	if (unlikely(err))
	goto err2;
	} else {
	if (unlikely((pkt->mask & RXE_GRH_MASK) == 0)) {
	pr_warn_ratelimited("no grh for mcast qpn\n");
	goto err1;
	}
	}

	pkt->qp = qp;
	return 0;

	err2:
	if (qp)
	rxe_drop_ref(qp);
	err1:
	return -EINVAL;
	}

	static inline void rxe_rcv_pkt(struct rxe_dev *rxe,
	struct rxe_pkt_info *pkt,
	struct sk_buff *skb)
	{
	if (pkt->mask & RXE_REQ_MASK)
	rxe_resp_queue_pkt(rxe, pkt->qp, skb);
	else
	rxe_comp_queue_pkt(rxe, pkt->qp, skb);
	}

	static void rxe_rcv_mcast_pkt(struct rxe_dev rxe, struct sk_buff skb)
	{
	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
	struct rxe_mc_grp *mcg;
	struct rxe_mc_elem *mce;
	struct rxe_qp *qp;
	union ib_gid dgid;
	int err;

	if (skb->protocol == htons(ETH_P_IP))
	ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
	(struct in6_addr *)&dgid);
	else if (skb->protocol == htons(ETH_P_IPV6))
	memcpy(&dgid, &ipv6_hdr(skb)->daddr, sizeof(dgid));

	/* lookup mcast group corresponding to mgid, takes a ref */
	mcg = rxe_pool_get_key(&rxe->mc_grp_pool, &dgid);
	if (!mcg)
	goto err1; /* mcast group not registered */

	spin_lock_bh(&mcg->mcg_lock);

	list_for_each_entry(mce, &mcg->qp_list, qp_list) {
	qp = mce->qp;
	pkt = SKB_TO_PKT(skb);

	/* validate qp for incoming packet */
	err = check_type_state(rxe, pkt, qp);
	if (err)
	continue;

	err = check_keys(rxe, pkt, bth_qpn(pkt), qp);
	if (err)
	continue;

	/* if not the last qp in the list
	* increase the users of the skb then post to the next qp
	*/
	if (mce->qp_list.next != &mcg->qp_list)
	skb_get(skb);

	pkt->qp = qp;
	rxe_add_ref(qp);
	rxe_rcv_pkt(rxe, pkt, skb);
	}

	spin_unlock_bh(&mcg->mcg_lock);

	rxe_drop_ref(mcg); /* drop ref from rxe_pool_get_key. */

	err1:
	kfree_skb(skb);
	}

	static int rxe_match_dgid(struct rxe_dev rxe, struct sk_buff skb)
	{
	union ib_gid dgid;
	union ib_gid *pdgid;

	if (skb->protocol == htons(ETH_P_IP)) {
	ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
	(struct in6_addr *)&dgid);
	pdgid = &dgid;
	} else {
	pdgid = (union ib_gid *)&ipv6_hdr(skb)->daddr;
	}

	return ib_find_cached_gid_by_port(&rxe->ib_dev, pdgid,
	IB_GID_TYPE_ROCE_UDP_ENCAP,
	1, skb->dev, NULL);
	}

	/* rxe_rcv is called from the interface driver */
	void rxe_rcv(struct sk_buff *skb)
	{
	int err;
	struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
	struct rxe_dev *rxe = pkt->rxe;
	__be32 *icrcp;
	u32 calc_icrc, pack_icrc;

	pkt->offset = 0;

	if (unlikely(skb->len < pkt->offset + RXE_BTH_BYTES))
	goto drop;

	if (unlikely(rxe_match_dgid(rxe, skb) < 0)) {
	pr_warn_ratelimited("failed matching dgid\n");
	goto drop;
	}

	pkt->opcode = bth_opcode(pkt);
	pkt->psn = bth_psn(pkt);
	pkt->qp = NULL;
	pkt->mask \|= rxe_opcode[pkt->opcode].mask;

	if (unlikely(skb->len < header_size(pkt)))
	goto drop;

	err = hdr_check(pkt);
	if (unlikely(err))
	goto drop;

	/* Verify ICRC */
	icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE);
	pack_icrc = be32_to_cpu(*icrcp);

	calc_icrc = rxe_icrc_hdr(pkt, skb);
	calc_icrc = rxe_crc32(rxe, calc_icrc, (u8 *)payload_addr(pkt),
	payload_size(pkt));
	calc_icrc = (__force u32)cpu_to_be32(~calc_icrc);
	if (unlikely(calc_icrc != pack_icrc)) {
	if (skb->protocol == htons(ETH_P_IPV6))
	pr_warn_ratelimited("bad ICRC from %pI6c\n",
	&ipv6_hdr(skb)->saddr);
	else if (skb->protocol == htons(ETH_P_IP))
	pr_warn_ratelimited("bad ICRC from %pI4\n",
	&ip_hdr(skb)->saddr);
	else
	pr_warn_ratelimited("bad ICRC from unknown\n");

	goto drop;
	}

	rxe_counter_inc(rxe, RXE_CNT_RCVD_PKTS);

	if (unlikely(bth_qpn(pkt) == IB_MULTICAST_QPN))
	rxe_rcv_mcast_pkt(rxe, skb);
	else
	rxe_rcv_pkt(rxe, pkt, skb);

	return;

	drop:
	if (pkt->qp)
	rxe_drop_ref(pkt->qp);

	kfree_skb(skb);
	}