net/mlx5: IPSec, Add support for ESN

Currently ESN is not supported with IPSec device offload.

This patch adds ESN support to IPsec device offload.
Implementing new xfrm device operation to synchronize offloading device
ESN with xfrm received SN. New QP command to update SA state at the
following:

           ESN 1                    ESN 2                  ESN 3
|-----------*-----------|-----------*-----------|-----------*
^           ^           ^           ^           ^           ^

^ - marks where QP command invoked to update the SA ESN state
    machine.
| - marks the start of the ESN scope (0-2^32-1). At this point move SA
    ESN overlap bit to zero and increment ESN.
* - marks the middle of the ESN scope (2^31). At this point move SA
    ESN overlap bit to one.

Signed-off-by: Aviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: Yossef Efraim <yossefe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

1 files changed, 108 insertions, 10 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
index f5b1d60f96f5..cf58c9637904 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c
@@ -38,18 +38,9 @@
 #include <linux/module.h>
 
 #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 */
-	unsigned int handle; /* Handle in SADB_RX */
-	struct xfrm_state *x;
-	struct mlx5e_ipsec *ipsec;
-	struct mlx5_accel_esp_xfrm *xfrm;
-	void *hw_context;
-};
 
 static struct mlx5e_ipsec_sa_entry *to_ipsec_sa_entry(struct xfrm_state *x)
 {
@@ -121,6 +112,40 @@ static void mlx5e_ipsec_sadb_rx_free(struct mlx5e_ipsec_sa_entry *sa_entry)
 	ida_simple_remove(&ipsec->halloc, sa_entry->handle);
 }
 
+static bool mlx5e_ipsec_update_esn_state(struct mlx5e_ipsec_sa_entry *sa_entry)
+{
+	struct xfrm_replay_state_esn *replay_esn;
+	u32 seq_bottom;
+	u8 overlap;
+	u32 *esn;
+
+	if (!(sa_entry->x->props.flags & XFRM_STATE_ESN)) {
+		sa_entry->esn_state.trigger = 0;
+		return false;
+	}
+
+	replay_esn = sa_entry->x->replay_esn;
+	seq_bottom = replay_esn->seq - replay_esn->replay_window + 1;
+	overlap = sa_entry->esn_state.overlap;
+
+	sa_entry->esn_state.esn = xfrm_replay_seqhi(sa_entry->x,
+						    htonl(seq_bottom));
+	esn = &sa_entry->esn_state.esn;
+
+	sa_entry->esn_state.trigger = 1;
+	if (unlikely(overlap && seq_bottom < MLX5E_IPSEC_ESN_SCOPE_MID)) {
+		++(*esn);
+		sa_entry->esn_state.overlap = 0;
+		return true;
+	} else if (unlikely(!overlap &&
+			    (seq_bottom >= MLX5E_IPSEC_ESN_SCOPE_MID))) {
+		sa_entry->esn_state.overlap = 1;
+		return true;
+	}
+
+	return false;
+}
+
 static void
 mlx5e_ipsec_build_accel_xfrm_attrs(struct mlx5e_ipsec_sa_entry *sa_entry,
 				   struct mlx5_accel_esp_xfrm_attrs *attrs)
@@ -152,6 +177,14 @@ mlx5e_ipsec_build_accel_xfrm_attrs(struct mlx5e_ipsec_sa_entry *sa_entry,
 	/* iv len */
 	aes_gcm->icv_len = x->aead->alg_icv_len;
 
+	/* esn */
+	if (sa_entry->esn_state.trigger) {
+		attrs->flags |= MLX5_ACCEL_ESP_FLAGS_ESN_TRIGGERED;
+		attrs->esn = sa_entry->esn_state.esn;
+		if (sa_entry->esn_state.overlap)
+			attrs->flags |= MLX5_ACCEL_ESP_FLAGS_ESN_STATE_OVERLAP;
+	}
+
 	/* rx handle */
 	attrs->sa_handle = sa_entry->handle;
 
@@ -187,7 +220,9 @@ static inline int mlx5e_xfrm_validate_state(struct xfrm_state *x)
 		netdev_info(netdev, "Cannot offload compressed xfrm states\n");
 		return -EINVAL;
 	}
-	if (x->props.flags & XFRM_STATE_ESN) {
+	if (x->props.flags & XFRM_STATE_ESN &&
+	    !(mlx5_accel_ipsec_device_caps(priv->mdev) &
+	    MLX5_ACCEL_IPSEC_CAP_ESN)) {
 		netdev_info(netdev, "Cannot offload ESN xfrm states\n");
 		return -EINVAL;
 	}
@@ -277,8 +312,14 @@ static int mlx5e_xfrm_add_state(struct xfrm_state *x)
 			netdev_info(netdev, "Failed adding to SADB_RX: %d\n", err);
 			goto err_entry;
 		}
+	} else {
+		sa_entry->set_iv_op = (x->props.flags & XFRM_STATE_ESN) ?
+				mlx5e_ipsec_set_iv_esn : mlx5e_ipsec_set_iv;
 	}
 
+	/* check esn */
+	mlx5e_ipsec_update_esn_state(sa_entry);
+
 	/* create xfrm */
 	mlx5e_ipsec_build_accel_xfrm_attrs(sa_entry, &attrs);
 	sa_entry->xfrm =
@@ -344,6 +385,7 @@ static void mlx5e_xfrm_free_state(struct xfrm_state *x)
 		return;
 
 	if (sa_entry->hw_context) {
+		flush_workqueue(sa_entry->ipsec->wq);
 		mlx5_accel_esp_free_hw_context(sa_entry->hw_context);
 		mlx5_accel_esp_destroy_xfrm(sa_entry->xfrm);
 	}
@@ -374,6 +416,12 @@ int mlx5e_ipsec_init(struct mlx5e_priv *priv)
 	ipsec->en_priv->ipsec = ipsec;
 	ipsec->no_trailer = !!(mlx5_accel_ipsec_device_caps(priv->mdev) &
 			       MLX5_ACCEL_IPSEC_CAP_RX_NO_TRAILER);
+	ipsec->wq = alloc_ordered_workqueue("mlx5e_ipsec: %s", 0,
+					    priv->netdev->name);
+	if (!ipsec->wq) {
+		kfree(ipsec);
+		return -ENOMEM;
+	}
 	netdev_dbg(priv->netdev, "IPSec attached to netdevice\n");
 	return 0;
 }
@@ -385,6 +433,9 @@ void mlx5e_ipsec_cleanup(struct mlx5e_priv *priv)
 	if (!ipsec)
 		return;
 
+	drain_workqueue(ipsec->wq);
+	destroy_workqueue(ipsec->wq);
+
 	ida_destroy(&ipsec->halloc);
 	kfree(ipsec);
 	priv->ipsec = NULL;
@@ -405,11 +456,58 @@ static bool mlx5e_ipsec_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
 	return true;
 }
 
+struct mlx5e_ipsec_modify_state_work {
+	struct work_struct		work;
+	struct mlx5_accel_esp_xfrm_attrs attrs;
+	struct mlx5e_ipsec_sa_entry	*sa_entry;
+};
+
+static void _update_xfrm_state(struct work_struct *work)
+{
+	int ret;
+	struct mlx5e_ipsec_modify_state_work *modify_work =
+		container_of(work, struct mlx5e_ipsec_modify_state_work, work);
+	struct mlx5e_ipsec_sa_entry *sa_entry = modify_work->sa_entry;
+
+	ret = mlx5_accel_esp_modify_xfrm(sa_entry->xfrm,
+					 &modify_work->attrs);
+	if (ret)
+		netdev_warn(sa_entry->ipsec->en_priv->netdev,
+			    "Not an IPSec offload device\n");
+
+	kfree(modify_work);
+}
+
+static void mlx5e_xfrm_advance_esn_state(struct xfrm_state *x)
+{
+	struct mlx5e_ipsec_sa_entry *sa_entry = to_ipsec_sa_entry(x);
+	struct mlx5e_ipsec_modify_state_work *modify_work;
+	bool need_update;
+
+	if (!sa_entry)
+		return;
+
+	need_update = mlx5e_ipsec_update_esn_state(sa_entry);
+	if (!need_update)
+		return;
+
+	modify_work = kzalloc(sizeof(*modify_work), GFP_ATOMIC);
+	if (!modify_work)
+		return;
+
+	mlx5e_ipsec_build_accel_xfrm_attrs(sa_entry, &modify_work->attrs);
+	modify_work->sa_entry = sa_entry;
+
+	INIT_WORK(&modify_work->work, _update_xfrm_state);
+	WARN_ON(!queue_work(sa_entry->ipsec->wq, &modify_work->work));
+}
+
 static const struct xfrmdev_ops mlx5e_ipsec_xfrmdev_ops = {
 	.xdo_dev_state_add	= mlx5e_xfrm_add_state,
 	.xdo_dev_state_delete	= mlx5e_xfrm_del_state,
 	.xdo_dev_state_free	= mlx5e_xfrm_free_state,
 	.xdo_dev_offload_ok	= mlx5e_ipsec_offload_ok,
+	.xdo_dev_state_advance_esn = mlx5e_xfrm_advance_esn_state,
 };
 
 void mlx5e_ipsec_build_netdev(struct mlx5e_priv *priv)