net/mlx5e: IPSec, Add Innova IPSec offload RX data path

In RX data path, the hardware prepends a special metadata ethertype
which indicates that the packet underwent decryption, and the result of
the authentication check.

Communicate this to the stack in skb->sp.

Make wqe_size large enough to account for the injected metadata.

Support only Linked-list RQ type.

IPSec offload RX packets may have useful CHECKSUM_COMPLETE information,
which the stack may not be able to use yet.
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Signed-off-by: Yevgeny Kliteynik <kliteyn@mellanox.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/Makefile

@@ -20,4 +20,4 @@ mlx5_core-$(CONFIG_MLX5_CORE_EN_DCB) +=  en_dcbnl.o
 
 mlx5_core-$(CONFIG_MLX5_CORE_IPOIB) += ipoib/ipoib.o ipoib/ethtool.o
 
-mlx5_core-$(CONFIG_MLX5_EN_IPSEC) += en_accel/ipsec.o
+mlx5_core-$(CONFIG_MLX5_EN_IPSEC) += en_accel/ipsec.o en_accel/ipsec_rxtx.o

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c

@@ -40,6 +40,7 @@
 #include "en.h"
 #include "accel/ipsec.h"
 #include "en_accel/ipsec.h"
+#include "en_accel/ipsec_rxtx.h"
 
 struct mlx5e_ipsec_sa_entry {
 	struct hlist_node hlist; /* Item in SADB_RX hashtable */
@@ -49,6 +50,24 @@ struct mlx5e_ipsec_sa_entry {
 	void *context;
 };
 
+struct xfrm_state *mlx5e_ipsec_sadb_rx_lookup(struct mlx5e_ipsec *ipsec,
+					      unsigned int handle)
+{
+	struct mlx5e_ipsec_sa_entry *sa_entry;
+	struct xfrm_state *ret = NULL;
+
+	rcu_read_lock();
+	hash_for_each_possible_rcu(ipsec->sadb_rx, sa_entry, hlist, handle)
+		if (sa_entry->handle == handle) {
+			ret = sa_entry->x;
+			xfrm_state_hold(ret);
+			break;
+		}
+	rcu_read_unlock();
+
+	return ret;
+}
+
 static int mlx5e_ipsec_sadb_rx_add(struct mlx5e_ipsec_sa_entry *sa_entry)
 {
 	struct mlx5e_ipsec *ipsec = sa_entry->ipsec;

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.h

@@ -41,14 +41,23 @@
 #include <linux/idr.h>
 
 #define MLX5E_IPSEC_SADB_RX_BITS 10
+#define MLX5E_METADATA_ETHER_TYPE (0x8CE4)
+#define MLX5E_METADATA_ETHER_LEN 8
 
 struct mlx5e_priv;
 
+struct mlx5e_ipsec_sw_stats {
+	atomic64_t ipsec_rx_drop_sp_alloc;
+	atomic64_t ipsec_rx_drop_sadb_miss;
+	atomic64_t ipsec_rx_drop_syndrome;
+};
+
 struct mlx5e_ipsec {
 	struct mlx5e_priv *en_priv;
 	DECLARE_HASHTABLE(sadb_rx, MLX5E_IPSEC_SADB_RX_BITS);
 	spinlock_t sadb_rx_lock; /* Protects sadb_rx and halloc */
 	struct ida halloc;
+	struct mlx5e_ipsec_sw_stats sw_stats;
 };
 
 int mlx5e_ipsec_init(struct mlx5e_priv *priv);

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.c

+/*
+ * Copyright (c) 2017 Mellanox Technologies. 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 <crypto/aead.h>
+#include <net/xfrm.h>
+
+#include "en_accel/ipsec_rxtx.h"
+#include "en_accel/ipsec.h"
+#include "en.h"
+
+enum {
+	MLX5E_IPSEC_RX_SYNDROME_DECRYPTED = 0x11,
+	MLX5E_IPSEC_RX_SYNDROME_AUTH_FAILED = 0x12,
+};
+
+struct mlx5e_ipsec_rx_metadata {
+	unsigned char   reserved;
+	__be32		sa_handle;
+} __packed;
+
+struct mlx5e_ipsec_metadata {
+	unsigned char syndrome;
+	union {
+		unsigned char raw[5];
+		/* from FPGA to host, on successful decrypt */
+		struct mlx5e_ipsec_rx_metadata rx;
+	} __packed content;
+	/* packet type ID field	*/
+	__be16 ethertype;
+} __packed;
+
+static inline struct xfrm_state *
+mlx5e_ipsec_build_sp(struct net_device *netdev, struct sk_buff *skb,
+		     struct mlx5e_ipsec_metadata *mdata)
+{
+	struct mlx5e_priv *priv = netdev_priv(netdev);
+	struct xfrm_offload *xo;
+	struct xfrm_state *xs;
+	u32 sa_handle;
+
+	skb->sp = secpath_dup(skb->sp);
+	if (unlikely(!skb->sp)) {
+		atomic64_inc(&priv->ipsec->sw_stats.ipsec_rx_drop_sp_alloc);
+		return NULL;
+	}
+
+	sa_handle = be32_to_cpu(mdata->content.rx.sa_handle);
+	xs = mlx5e_ipsec_sadb_rx_lookup(priv->ipsec, sa_handle);
+	if (unlikely(!xs)) {
+		atomic64_inc(&priv->ipsec->sw_stats.ipsec_rx_drop_sadb_miss);
+		return NULL;
+	}
+
+	skb->sp->xvec[skb->sp->len++] = xs;
+	skb->sp->olen++;
+
+	xo = xfrm_offload(skb);
+	xo->flags = CRYPTO_DONE;
+	switch (mdata->syndrome) {
+	case MLX5E_IPSEC_RX_SYNDROME_DECRYPTED:
+		xo->status = CRYPTO_SUCCESS;
+		break;
+	case MLX5E_IPSEC_RX_SYNDROME_AUTH_FAILED:
+		xo->status = CRYPTO_TUNNEL_ESP_AUTH_FAILED;
+		break;
+	default:
+		atomic64_inc(&priv->ipsec->sw_stats.ipsec_rx_drop_syndrome);
+		return NULL;
+	}
+	return xs;
+}
+
+struct sk_buff *mlx5e_ipsec_handle_rx_skb(struct net_device *netdev,
+					  struct sk_buff *skb)
+{
+	struct mlx5e_ipsec_metadata *mdata;
+	struct ethhdr *old_eth;
+	struct ethhdr *new_eth;
+	struct xfrm_state *xs;
+	__be16 *ethtype;
+
+	/* Detect inline metadata */
+	if (skb->len < ETH_HLEN + MLX5E_METADATA_ETHER_LEN)
+		return skb;
+	ethtype = (__be16 *)(skb->data + ETH_ALEN * 2);
+	if (*ethtype != cpu_to_be16(MLX5E_METADATA_ETHER_TYPE))
+		return skb;
+
+	/* Use the metadata */
+	mdata = (struct mlx5e_ipsec_metadata *)(skb->data + ETH_HLEN);
+	xs = mlx5e_ipsec_build_sp(netdev, skb, mdata);
+	if (unlikely(!xs)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	/* Remove the metadata from the buffer */
+	old_eth = (struct ethhdr *)skb->data;
+	new_eth = (struct ethhdr *)(skb->data + MLX5E_METADATA_ETHER_LEN);
+	memmove(new_eth, old_eth, 2 * ETH_ALEN);
+	/* Ethertype is already in its new place */
+	skb_pull_inline(skb, MLX5E_METADATA_ETHER_LEN);
+
+	return skb;
+}

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_rxtx.h

+/*
+ * Copyright (c) 2017 Mellanox Technologies. 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.
+ *
+ */
+
+#ifndef __MLX5E_IPSEC_RXTX_H__
+#define __MLX5E_IPSEC_RXTX_H__
+
+#include <linux/skbuff.h>
+#include "en.h"
+
+struct sk_buff *mlx5e_ipsec_handle_rx_skb(struct net_device *netdev,
+					  struct sk_buff *skb);
+void mlx5e_ipsec_handle_rx_cqe(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe);
+
+#endif	/* __MLX5E_IPSEC_RXTX_H__ */

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

@@ -40,6 +40,8 @@
 #include "en_tc.h"
 #include "en_rep.h"
 #include "en_accel/ipsec.h"
+#include "en_accel/ipsec_rxtx.h"
+#include "accel/ipsec.h"
 #include "vxlan.h"
 
 struct mlx5e_rq_param {
@@ -116,7 +118,7 @@ void mlx5e_set_rq_type_params(struct mlx5_core_dev *mdev,
 static void mlx5e_set_rq_params(struct mlx5_core_dev *mdev, struct mlx5e_params *params)
 {
 	u8 rq_type = mlx5e_check_fragmented_striding_rq_cap(mdev) &&
-		    !params->xdp_prog ?
+		    !params->xdp_prog && !MLX5_IPSEC_DEV(mdev) ?
 		    MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ :
 		    MLX5_WQ_TYPE_LINKED_LIST;
 	mlx5e_set_rq_type_params(mdev, params, rq_type);
@@ -593,6 +595,13 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c,
 		rq->dealloc_wqe = mlx5e_dealloc_rx_mpwqe;
 
 		rq->handle_rx_cqe = c->priv->profile->rx_handlers.handle_rx_cqe_mpwqe;
+#ifdef CONFIG_MLX5_EN_IPSEC
+		if (MLX5_IPSEC_DEV(mdev)) {
+			err = -EINVAL;
+			netdev_err(c->netdev, "MPWQE RQ with IPSec offload not supported\n");
+			goto err_rq_wq_destroy;
+		}
+#endif
 		if (!rq->handle_rx_cqe) {
 			err = -EINVAL;
 			netdev_err(c->netdev, "RX handler of MPWQE RQ is not set, err %d\n", err);
@@ -625,7 +634,12 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c,
 		rq->alloc_wqe = mlx5e_alloc_rx_wqe;
 		rq->dealloc_wqe = mlx5e_dealloc_rx_wqe;
 
-		rq->handle_rx_cqe = c->priv->profile->rx_handlers.handle_rx_cqe;
+#ifdef CONFIG_MLX5_EN_IPSEC
+		if (c->priv->ipsec)
+			rq->handle_rx_cqe = mlx5e_ipsec_handle_rx_cqe;
+		else
+#endif
+			rq->handle_rx_cqe = c->priv->profile->rx_handlers.handle_rx_cqe;
 		if (!rq->handle_rx_cqe) {
 			kfree(rq->wqe.frag_info);
 			err = -EINVAL;
@@ -636,6 +650,10 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c,
 		rq->buff.wqe_sz = params->lro_en  ?
 				params->lro_wqe_sz :
 				MLX5E_SW2HW_MTU(c->priv, c->netdev->mtu);
+#ifdef CONFIG_MLX5_EN_IPSEC
+		if (MLX5_IPSEC_DEV(mdev))
+			rq->buff.wqe_sz += MLX5E_METADATA_ETHER_LEN;
+#endif
 		rq->wqe.page_reuse = !params->xdp_prog && !params->lro_en;
 		byte_count = rq->buff.wqe_sz;
 

drivers/net/ethernet/mellanox/mlx5/core/en_rx.c

@@ -41,6 +41,7 @@
 #include "eswitch.h"
 #include "en_rep.h"
 #include "ipoib/ipoib.h"
+#include "en_accel/ipsec_rxtx.h"
 
 static inline bool mlx5e_rx_hw_stamp(struct mlx5e_tstamp *tstamp)
 {
@@ -1183,3 +1184,43 @@ void mlx5i_handle_rx_cqe(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe)
 }
 
 #endif /* CONFIG_MLX5_CORE_IPOIB */
+
+#ifdef CONFIG_MLX5_EN_IPSEC
+
+void mlx5e_ipsec_handle_rx_cqe(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe)
+{
+	struct mlx5e_wqe_frag_info *wi;
+	struct mlx5e_rx_wqe *wqe;
+	__be16 wqe_counter_be;
+	struct sk_buff *skb;
+	u16 wqe_counter;
+	u32 cqe_bcnt;
+
+	wqe_counter_be = cqe->wqe_counter;
+	wqe_counter    = be16_to_cpu(wqe_counter_be);
+	wqe            = mlx5_wq_ll_get_wqe(&rq->wq, wqe_counter);
+	wi             = &rq->wqe.frag_info[wqe_counter];
+	cqe_bcnt       = be32_to_cpu(cqe->byte_cnt);
+
+	skb = skb_from_cqe(rq, cqe, wi, cqe_bcnt);
+	if (unlikely(!skb)) {
+		/* a DROP, save the page-reuse checks */
+		mlx5e_free_rx_wqe(rq, wi);
+		goto wq_ll_pop;
+	}
+	skb = mlx5e_ipsec_handle_rx_skb(rq->netdev, skb);
+	if (unlikely(!skb)) {
+		mlx5e_free_rx_wqe(rq, wi);
+		goto wq_ll_pop;
+	}
+
+	mlx5e_complete_rx_cqe(rq, cqe, cqe_bcnt, skb);
+	napi_gro_receive(rq->cq.napi, skb);
+
+	mlx5e_free_rx_wqe_reuse(rq, wi);
+wq_ll_pop:
+	mlx5_wq_ll_pop(&rq->wq, wqe_counter_be,
+		       &wqe->next.next_wqe_index);
+}
+
+#endif /* CONFIG_MLX5_EN_IPSEC */