nfp: add framework to support ipsec offloading

A new metadata type and config structure are introduced to
interact with firmware to support ipsec offloading. This
feature relies on specific firmware that supports ipsec
encrypt/decrypt by advertising related capability bit.

The xfrm callbacks which interact with upper layer are
implemented in the following patch.

Based on initial work of Norm Bagley <norman.bagley@netronome.com>.
Signed-off-by: Huanhuan Wang <huanhuan.wang@corigine.com>
Reviewed-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/Kconfig

@@ -54,6 +54,17 @@ config NFP_APP_ABM_NIC
 	  functionality.
 	  Code will be built into the nfp.ko driver.
 
+config NFP_NET_IPSEC
+	bool "NFP IPsec crypto offload support"
+	depends on NFP
+	depends on XFRM_OFFLOAD
+	default y
+	help
+	  Enable driver support IPsec crypto offload on NFP NIC.
+	  Say Y, if you are planning to make use of IPsec crypto
+	  offload. NOTE that IPsec crypto offload on NFP NIC
+	  requires specific FW to work.
+
 config NFP_DEBUG
 	bool "Debug support for Netronome(R) NFP4000/NFP6000 NIC drivers"
 	depends on NFP

drivers/net/ethernet/netronome/nfp/Makefile

@@ -80,4 +80,6 @@ nfp-objs += \
 	    abm/main.o
 endif
 
+nfp-$(CONFIG_NFP_NET_IPSEC) += crypto/ipsec.o nfd3/ipsec.o
+
 nfp-$(CONFIG_NFP_DEBUG) += nfp_net_debugfs.o

drivers/net/ethernet/netronome/nfp/crypto/crypto.h

@@ -39,4 +39,27 @@ nfp_net_tls_rx_resync_req(struct net_device *netdev,
 }
 #endif
 
+/* IPsec related structures and functions */
+struct nfp_ipsec_offload {
+	u32 seq_hi;
+	u32 seq_low;
+	u32 handle;
+};
+
+#ifndef CONFIG_NFP_NET_IPSEC
+static inline void nfp_net_ipsec_init(struct nfp_net *nn)
+{
+}
+
+static inline void nfp_net_ipsec_clean(struct nfp_net *nn)
+{
+}
+#else
+void nfp_net_ipsec_init(struct nfp_net *nn);
+void nfp_net_ipsec_clean(struct nfp_net *nn);
+bool nfp_net_ipsec_tx_prep(struct nfp_net_dp *dp, struct sk_buff *skb,
+			   struct nfp_ipsec_offload *offload_info);
+int nfp_net_ipsec_rx(struct nfp_meta_parsed *meta, struct sk_buff *skb);
+#endif
+
 #endif

drivers/net/ethernet/netronome/nfp/crypto/ipsec.c

+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Copyright (C) 2018 Netronome Systems, Inc */
+/* Copyright (C) 2021 Corigine, Inc */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <asm/unaligned.h>
+#include <linux/ktime.h>
+#include <net/xfrm.h>
+
+#include "../nfp_net_ctrl.h"
+#include "../nfp_net.h"
+#include "crypto.h"
+
+#define NFP_NET_IPSEC_MAX_SA_CNT  (16 * 1024) /* Firmware support a maximum of 16K SA offload */
+
+static int nfp_net_xfrm_add_state(struct xfrm_state *x)
+{
+	return -EOPNOTSUPP;
+}
+
+static void nfp_net_xfrm_del_state(struct xfrm_state *x)
+{
+}
+
+static bool nfp_net_ipsec_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
+{
+	return false;
+}
+
+static const struct xfrmdev_ops nfp_net_ipsec_xfrmdev_ops = {
+	.xdo_dev_state_add = nfp_net_xfrm_add_state,
+	.xdo_dev_state_delete = nfp_net_xfrm_del_state,
+	.xdo_dev_offload_ok = nfp_net_ipsec_offload_ok,
+};
+
+void nfp_net_ipsec_init(struct nfp_net *nn)
+{
+	if (!(nn->cap_w1 & NFP_NET_CFG_CTRL_IPSEC))
+		return;
+
+	xa_init_flags(&nn->xa_ipsec, XA_FLAGS_ALLOC);
+	nn->dp.netdev->xfrmdev_ops = &nfp_net_ipsec_xfrmdev_ops;
+}
+
+void nfp_net_ipsec_clean(struct nfp_net *nn)
+{
+	if (!(nn->cap_w1 & NFP_NET_CFG_CTRL_IPSEC))
+		return;
+
+	WARN_ON(!xa_empty(&nn->xa_ipsec));
+	xa_destroy(&nn->xa_ipsec);
+}
+
+bool nfp_net_ipsec_tx_prep(struct nfp_net_dp *dp, struct sk_buff *skb,
+			   struct nfp_ipsec_offload *offload_info)
+{
+	struct xfrm_offload *xo = xfrm_offload(skb);
+	struct xfrm_state *x;
+
+	x = xfrm_input_state(skb);
+	if (!x)
+		return false;
+
+	offload_info->seq_hi = xo->seq.hi;
+	offload_info->seq_low = xo->seq.low;
+	offload_info->handle = x->xso.offload_handle;
+
+	return true;
+}
+
+int nfp_net_ipsec_rx(struct nfp_meta_parsed *meta, struct sk_buff *skb)
+{
+	struct net_device *netdev = skb->dev;
+	struct xfrm_offload *xo;
+	struct xfrm_state *x;
+	struct sec_path *sp;
+	struct nfp_net *nn;
+	u32 saidx;
+
+	nn = netdev_priv(netdev);
+
+	saidx = meta->ipsec_saidx - 1;
+	if (saidx >= NFP_NET_IPSEC_MAX_SA_CNT)
+		return -EINVAL;
+
+	sp = secpath_set(skb);
+	if (unlikely(!sp))
+		return -ENOMEM;
+
+	xa_lock(&nn->xa_ipsec);
+	x = xa_load(&nn->xa_ipsec, saidx);
+	xa_unlock(&nn->xa_ipsec);
+	if (!x)
+		return -EINVAL;
+
+	xfrm_state_hold(x);
+	sp->xvec[sp->len++] = x;
+	sp->olen++;
+	xo = xfrm_offload(skb);
+	xo->flags = CRYPTO_DONE;
+	xo->status = CRYPTO_SUCCESS;
+
+	return 0;
+}

drivers/net/ethernet/netronome/nfp/nfd3/dp.c

@@ -4,6 +4,7 @@
 #include <linux/bpf_trace.h>
 #include <linux/netdevice.h>
 #include <linux/bitfield.h>
+#include <net/xfrm.h>
 
 #include "../nfp_app.h"
 #include "../nfp_net.h"
@@ -167,28 +168,34 @@ nfp_nfd3_tx_csum(struct nfp_net_dp *dp, struct nfp_net_r_vector *r_vec,
 	u64_stats_update_end(&r_vec->tx_sync);
 }
 
-static int nfp_nfd3_prep_tx_meta(struct nfp_net_dp *dp, struct sk_buff *skb, u64 tls_handle)
+static int nfp_nfd3_prep_tx_meta(struct nfp_net_dp *dp, struct sk_buff *skb,
+				 u64 tls_handle, bool *ipsec)
 {
 	struct metadata_dst *md_dst = skb_metadata_dst(skb);
+	struct nfp_ipsec_offload offload_info;
 	unsigned char *data;
 	bool vlan_insert;
 	u32 meta_id = 0;
 	int md_bytes;
 
-	if (unlikely(md_dst || tls_handle)) {
-		if (unlikely(md_dst && md_dst->type != METADATA_HW_PORT_MUX))
-			md_dst = NULL;
-	}
+#ifdef CONFIG_NFP_NET_IPSEC
+	if (xfrm_offload(skb))
+		*ipsec = nfp_net_ipsec_tx_prep(dp, skb, &offload_info);
+#endif
+
+	if (unlikely(md_dst && md_dst->type != METADATA_HW_PORT_MUX))
+		md_dst = NULL;
 
 	vlan_insert = skb_vlan_tag_present(skb) && (dp->ctrl & NFP_NET_CFG_CTRL_TXVLAN_V2);
 
-	if (!(md_dst || tls_handle || vlan_insert))
+	if (!(md_dst || tls_handle || vlan_insert || *ipsec))
 		return 0;
 
 	md_bytes = sizeof(meta_id) +
 		   !!md_dst * NFP_NET_META_PORTID_SIZE +
 		   !!tls_handle * NFP_NET_META_CONN_HANDLE_SIZE +
-		   vlan_insert * NFP_NET_META_VLAN_SIZE;
+		   vlan_insert * NFP_NET_META_VLAN_SIZE +
+		   *ipsec * NFP_NET_META_IPSEC_FIELD_SIZE; /* IPsec has 12 bytes of metadata */
 
 	if (unlikely(skb_cow_head(skb, md_bytes)))
 		return -ENOMEM;
@@ -218,6 +225,19 @@ static int nfp_nfd3_prep_tx_meta(struct nfp_net_dp *dp, struct sk_buff *skb, u64
 		meta_id <<= NFP_NET_META_FIELD_SIZE;
 		meta_id |= NFP_NET_META_VLAN;
 	}
+	if (*ipsec) {
+		/* IPsec has three consecutive 4-bit IPsec metadata types,
+		 * so in total IPsec has three 4 bytes of metadata.
+		 */
+		data -= NFP_NET_META_IPSEC_SIZE;
+		put_unaligned_be32(offload_info.seq_hi, data);
+		data -= NFP_NET_META_IPSEC_SIZE;
+		put_unaligned_be32(offload_info.seq_low, data);
+		data -= NFP_NET_META_IPSEC_SIZE;
+		put_unaligned_be32(offload_info.handle - 1, data);
+		meta_id <<= NFP_NET_META_IPSEC_FIELD_SIZE;
+		meta_id |= NFP_NET_META_IPSEC << 8 | NFP_NET_META_IPSEC << 4 | NFP_NET_META_IPSEC;
+	}
 
 	data -= sizeof(meta_id);
 	put_unaligned_be32(meta_id, data);
@@ -246,6 +266,7 @@ netdev_tx_t nfp_nfd3_tx(struct sk_buff *skb, struct net_device *netdev)
 	dma_addr_t dma_addr;
 	unsigned int fsize;
 	u64 tls_handle = 0;
+	bool ipsec = false;
 	u16 qidx;
 
 	dp = &nn->dp;
@@ -273,7 +294,7 @@ netdev_tx_t nfp_nfd3_tx(struct sk_buff *skb, struct net_device *netdev)
 		return NETDEV_TX_OK;
 	}
 
-	md_bytes = nfp_nfd3_prep_tx_meta(dp, skb, tls_handle);
+	md_bytes = nfp_nfd3_prep_tx_meta(dp, skb, tls_handle, &ipsec);
 	if (unlikely(md_bytes < 0))
 		goto err_flush;
 
@@ -312,6 +333,8 @@ netdev_tx_t nfp_nfd3_tx(struct sk_buff *skb, struct net_device *netdev)
 		txd->vlan = cpu_to_le16(skb_vlan_tag_get(skb));
 	}
 
+	if (ipsec)
+		nfp_nfd3_ipsec_tx(txd, skb);
 	/* Gather DMA */
 	if (nr_frags > 0) {
 		__le64 second_half;
@@ -764,6 +787,15 @@ nfp_nfd3_parse_meta(struct net_device *netdev, struct nfp_meta_parsed *meta,
 				return false;
 			data += sizeof(struct nfp_net_tls_resync_req);
 			break;
+#ifdef CONFIG_NFP_NET_IPSEC
+		case NFP_NET_META_IPSEC:
+			/* Note: IPsec packet will have zero saidx, so need add 1
+			 * to indicate packet is IPsec packet within driver.
+			 */
+			meta->ipsec_saidx = get_unaligned_be32(data) + 1;
+			data += 4;
+			break;
+#endif
 		default:
 			return true;
 		}
@@ -876,12 +908,11 @@ static int nfp_nfd3_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 	struct nfp_net_dp *dp = &r_vec->nfp_net->dp;
 	struct nfp_net_tx_ring *tx_ring;
 	struct bpf_prog *xdp_prog;
+	int idx, pkts_polled = 0;
 	bool xdp_tx_cmpl = false;
 	unsigned int true_bufsz;
 	struct sk_buff *skb;
-	int pkts_polled = 0;
 	struct xdp_buff xdp;
-	int idx;
 
 	xdp_prog = READ_ONCE(dp->xdp_prog);
 	true_bufsz = xdp_prog ? PAGE_SIZE : dp->fl_bufsz;
@@ -1081,6 +1112,13 @@ static int nfp_nfd3_rx(struct nfp_net_rx_ring *rx_ring, int budget)
 			continue;
 		}
 
+#ifdef CONFIG_NFP_NET_IPSEC
+		if (meta.ipsec_saidx != 0 && unlikely(nfp_net_ipsec_rx(&meta, skb))) {
+			nfp_nfd3_rx_drop(dp, r_vec, rx_ring, NULL, skb);
+			continue;
+		}
+#endif
+
 		if (meta_len_xdp)
 			skb_metadata_set(skb, meta_len_xdp);
 

drivers/net/ethernet/netronome/nfp/nfd3/ipsec.c

+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Copyright (C) 2018 Netronome Systems, Inc */
+/* Copyright (C) 2021 Corigine, Inc */
+
+#include <net/xfrm.h>
+
+#include "../nfp_net.h"
+#include "nfd3.h"
+
+void nfp_nfd3_ipsec_tx(struct nfp_nfd3_tx_desc *txd, struct sk_buff *skb)
+{
+	struct xfrm_state *x = xfrm_input_state(skb);
+
+	if (x->xso.dev && (x->xso.dev->features & NETIF_F_HW_ESP_TX_CSUM)) {
+		txd->flags |= NFD3_DESC_TX_CSUM | NFD3_DESC_TX_IP4_CSUM |
+			      NFD3_DESC_TX_TCP_CSUM | NFD3_DESC_TX_UDP_CSUM;
+	}
+}

drivers/net/ethernet/netronome/nfp/nfd3/nfd3.h

@@ -103,4 +103,12 @@ void nfp_nfd3_rx_ring_fill_freelist(struct nfp_net_dp *dp,
 void nfp_nfd3_xsk_tx_free(struct nfp_nfd3_tx_buf *txbuf);
 int nfp_nfd3_xsk_poll(struct napi_struct *napi, int budget);
 
+#ifndef CONFIG_NFP_NET_IPSEC
+static inline void nfp_nfd3_ipsec_tx(struct nfp_nfd3_tx_desc *txd, struct sk_buff *skb)
+{
+}
+#else
+void nfp_nfd3_ipsec_tx(struct nfp_nfd3_tx_desc *txd, struct sk_buff *skb);
+#endif
+
 #endif

drivers/net/ethernet/netronome/nfp/nfp_net.h

@@ -263,6 +263,10 @@ struct nfp_meta_parsed {
 		u8 tpid;
 		u16 tci;
 	} vlan;
+
+#ifdef CONFIG_NFP_NET_IPSEC
+	u32 ipsec_saidx;
+#endif
 };
 
 struct nfp_net_rx_hash {
@@ -584,6 +588,7 @@ struct nfp_net_dp {
  * @qcp_cfg:            Pointer to QCP queue used for configuration notification
  * @tx_bar:             Pointer to mapped TX queues
  * @rx_bar:             Pointer to mapped FL/RX queues
+ * @xa_ipsec:           IPsec xarray SA data
  * @tlv_caps:		Parsed TLV capabilities
  * @ktls_tx_conn_cnt:	Number of offloaded kTLS TX connections
  * @ktls_rx_conn_cnt:	Number of offloaded kTLS RX connections
@@ -672,6 +677,10 @@ struct nfp_net {
 	u8 __iomem *tx_bar;
 	u8 __iomem *rx_bar;
 
+#ifdef CONFIG_NFP_NET_IPSEC
+	struct xarray xa_ipsec;
+#endif
+
 	struct nfp_net_tlv_caps tlv_caps;
 
 	unsigned int ktls_tx_conn_cnt;

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

@@ -2564,6 +2564,8 @@ int nfp_net_init(struct nfp_net *nn)
 		err = nfp_net_tls_init(nn);
 		if (err)
 			goto err_clean_mbox;
+
+		nfp_net_ipsec_init(nn);
 	}
 
 	nfp_net_vecs_init(nn);
@@ -2587,6 +2589,7 @@ void nfp_net_clean(struct nfp_net *nn)
 		return;
 
 	unregister_netdev(nn->dp.netdev);
+	nfp_net_ipsec_clean(nn);
 	nfp_ccm_mbox_clean(nn);
 	nfp_net_reconfig_wait_posted(nn);
 }

drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h

@@ -48,6 +48,7 @@
 #define NFP_NET_META_CSUM		6 /* checksum complete type */
 #define NFP_NET_META_CONN_HANDLE	7
 #define NFP_NET_META_RESYNC_INFO	8 /* RX resync info request */
+#define NFP_NET_META_IPSEC		9 /* IPsec SA index for tx and rx */
 
 #define NFP_META_PORT_ID_CTRL		~0U
 
@@ -55,6 +56,8 @@
 #define NFP_NET_META_VLAN_SIZE			4
 #define NFP_NET_META_PORTID_SIZE		4
 #define NFP_NET_META_CONN_HANDLE_SIZE		8
+#define NFP_NET_META_IPSEC_SIZE			4
+#define NFP_NET_META_IPSEC_FIELD_SIZE		12
 /* Hash type pre-pended when a RSS hash was computed */
 #define NFP_NET_RSS_NONE		0
 #define NFP_NET_RSS_IPV4		1
@@ -263,6 +266,7 @@
  */
 #define NFP_NET_CFG_CTRL_WORD1		0x0098
 #define   NFP_NET_CFG_CTRL_PKT_TYPE	  (0x1 << 0) /* Pkttype offload */
+#define   NFP_NET_CFG_CTRL_IPSEC	  (0x1 << 1) /* IPsec offload */
 
 #define NFP_NET_CFG_CAP_WORD1		0x00a4