Extend XFRM core to allow full offload configuration

PATCH Superseded Leon Romanovsky 1 participant 9 messages Oct 23, 2022

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Leon Romanovsky

author

2022-10-23 12:06 UTC #0 lore raw

v5 cover Extend XFRM core to allow full offload configuration

From: Leon Romanovsky <[email protected]>

Changelog:
v5:
* Rebased to latest ipsec-next.
* Replaced HW priority patch with solution which mimics separated SPDs for SW and HW. See more description in this cover letter.
* Dropped RFC tag, usecase, API and implementation are clear.
v4: https://lore.kernel.org/all/[email protected]
* Changed title from "PATCH" to "PATCH RFC" per-request.
* Added two new patches: one to update hard/soft limits and another initial take on documentation.
* Added more info about lifetime/rekeying flow to cover letter, see relevant section.
* perf traces for crypto mode will come later.
v3: https://lore.kernel.org/all/[email protected]
* I didn't hear any suggestion what term to use instead of
"full offload", so left it as is. It is used in commit messages and documentation only and easy to rename.
* Added performance data and background info to cover letter
* Reused xfrm_output_resume() function to support multiple XFRM transformations
* Add PMTU check in addition to driver .xdo_dev_offload_ok validation
* Documentation is in progress, but not part of this series yet.
v2: https://lore.kernel.org/all/[email protected]
* Rebased to latest 6.0-rc1
* Add an extra check in TX datapath patch to validate packets before forwarding to HW.
* Added policy cleanup logic in case of netdev down event
v1: https://lore.kernel.org/all/[email protected]
* Moved comment to be before if (...) in third patch.
v0: https://lore.kernel.org/all/[email protected]
-----------------------------------------------------------------------

The following series extends XFRM core code to handle a new type of IPsec offload - full offload.

In this mode, the HW is going to be responsible for the whole data path, so both policy and state should be offloaded.

IPsec full offload is an improved version of IPsec crypto mode, In full mode, HW is responsible to trim/add headers in addition to decrypt/encrypt. In this mode, the packet arrives to the stack as already decrypted and vice versa for TX (exits to HW as not-encrypted).

Devices that implement IPsec full offload mode offload policies too. In the RX path, it causes the situation that HW can't effectively handle mixed SW and HW priorities unless users make sure that HW offloaded policies have higher priorities.

It means that we don't need to perform any search of inexact policies and/or priority checks if HW policy was discovered. In such situation, the HW will catch the packets anyway and HW can still implement inexact lookups.

In case specific policy is not found, we will continue with full lookup and check for existence of HW policies in inexact list.

HW policies are added to the head of SPD to ensure fast lookup, as XFRM iterates over all policies in the loop.

This simple solution allows us to achieve same benefits of separate HW/SW policies databases without over-engineering the code to iterate and manage two databases at the same path.

To not over-engineer the code, HW policies are treated as SW ones and don't take into account netdev to allow reuse of the same priorities for different devices.

There are several deliberate limitations:
* No software fallback
* Fragments are dropped, both in RX and TX
* No sockets policies
* Only IPsec transport mode is implemented

================================================================================
Rekeying:

In order to support rekeying, as XFRM core is skipped, the HW/driver should do the following:
* Count the handled packets
* Raise event that limits are reached
* Drop packets once hard limit is occurred.

The XFRM core calls to newly introduced xfrm_dev_state_update_curlft() function in order to perform sync between device statistics and internal structures. On HW limit event, driver calls to xfrm_state_check_expire() to allow XFRM core take relevant decisions.

This separation between control logic (in XFRM) and data plane allows us to fully reuse SW stack.

================================================================================
Configuration:

iproute2: https://lore.kernel.org/netdev/[email protected]/

Full offload mode:
ip xfrm state offload full dev <if-name> dir <in|out> ip xfrm policy .... offload full dev <if-name>
Crypto offload mode:
ip xfrm state offload crypto dev <if-name> dir <in|out>
or (backward compatibility)
ip xfrm state offload dev <if-name> dir <in|out>

================================================================================
Performance results:

TCP multi-stream, using iperf3 instance per-CPU.

+----------------------+--------+--------+--------+--------+---------+---------+
|                      | 1 CPU  | 2 CPUs | 4 CPUs | 8 CPUs | 16 CPUs | 32 CPUs |
|                      +--------+--------+--------+--------+---------+---------+
|                      |                   BW (Gbps)                           |
+----------------------+--------+--------+-------+---------+---------+---------+
| Baseline             | 27.9   | 59     | 93.1  | 92.8    | 93.7    | 94.4    |
+----------------------+--------+--------+-------+---------+---------+---------+
| Software IPsec       | 6      | 11.9   | 23.3  | 45.9    | 83.8    | 91.8    |
+----------------------+--------+--------+-------+---------+---------+---------+
| IPsec crypto offload | 15     | 29.7   | 58.5  | 89.6    | 90.4    | 90.8    |
+----------------------+--------+--------+-------+---------+---------+---------+
| IPsec full offload   | 28     | 57     | 90.7  | 91      | 91.3    | 91.9    |

IPsec full offload mode behaves as baseline and reaches linerate with same amount of CPUs.

Setups details (similar for both sides):
* NIC: ConnectX6-DX dual port, 100 Gbps each. Single port used in the tests.
* CPU: Intel(R) Xeon(R) Platinum 8380 CPU @ 2.30GHz

================================================================================
Series together with mlx5 part:
https://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma.git/log/?h=xfrm-next

Thanks

Leon Romanovsky (8):
xfrm: add new full offload flag
xfrm: allow state full offload mode
xfrm: add an interface to offload policy
xfrm: add TX datapath support for IPsec full offload mode
xfrm: add RX datapath protection for IPsec full offload mode
xfrm: Speed-up lookup of HW policies
xfrm: add support to HW update soft and hard limits
xfrm: document IPsec full offload mode

 Documentation/networking/xfrm_device.rst      |  62 +++++++--
 .../inline_crypto/ch_ipsec/chcr_ipsec.c       |   4 +
 .../net/ethernet/intel/ixgbe/ixgbe_ipsec.c    |   5 +
 drivers/net/ethernet/intel/ixgbevf/ipsec.c    |   5 +
 .../mellanox/mlx5/core/en_accel/ipsec.c       |   4 +
 drivers/net/netdevsim/ipsec.c                 |   5 +
 include/linux/netdevice.h                     |   4 +
 include/net/xfrm.h                            | 123 ++++++++++++++----
 include/uapi/linux/xfrm.h                     |   6 +
 net/xfrm/xfrm_device.c                        | 109 ++++++++++++++--
 net/xfrm/xfrm_output.c                        |  13 +-
 net/xfrm/xfrm_policy.c                        |  76 ++++++++++-
 net/xfrm/xfrm_state.c                         |   4 +
 net/xfrm/xfrm_user.c                          |  20 +++
 14 files changed, 397 insertions(+), 43 deletions(-)

Signature · 1 line

2.37.3

Leon Romanovsky

author

2022-10-23 12:06 UTC #1 lore raw

PATCH v5 1/8 xfrm: add new full offload flag

From: Leon Romanovsky <[email protected]>

In the next patches, the xfrm core code will be extended to support new type of offload - full offload. In that mode, both policy and state should be specially configured in order to perform whole offloaded data path.

Full offload takes care of encryption, decryption, encapsulation and other operations with headers.

As this mode is new for XFRM policy flow, we can "start fresh" with flag bits and release first and second bit for future use.

Reviewed-by Raed Salem <[email protected]>

Signed-off-by Leon Romanovsky <[email protected]>

---
 include/net/xfrm.h        | 7 +++++++
 include/uapi/linux/xfrm.h | 6 ++++++
 net/xfrm/xfrm_device.c    | 3 +++
 net/xfrm/xfrm_user.c      | 2 ++
 4 files changed, 18 insertions(+)

include/net/xfrm.h +7 -0

index dbc81f5eb553..c82401b706d5 100644
@@ -131,12 +131,19 @@ enum {
 	XFRM_DEV_OFFLOAD_OUT,
 };
 
+enum {
+	XFRM_DEV_OFFLOAD_UNSPECIFIED,
+	XFRM_DEV_OFFLOAD_CRYPTO,
+	XFRM_DEV_OFFLOAD_FULL,
+};
+
 struct xfrm_dev_offload {
 	struct net_device	*dev;
 	netdevice_tracker	dev_tracker;
 	struct net_device	*real_dev;
 	unsigned long		offload_handle;
 	u8			dir : 2;
+	u8			type : 2;
 };
 
 struct xfrm_mode {

include/uapi/linux/xfrm.h +6 -0

index 4f84ea7ee14c..463c6c1af23a 100644
@@ -519,6 +519,12 @@ struct xfrm_user_offload {
  */
 #define XFRM_OFFLOAD_IPV6	1
 #define XFRM_OFFLOAD_INBOUND	2
+/* Two bits above are relevant for state path only, while
+ * offload is used for both policy and state flows.
+ *
+ * In policy offload mode, they are free and can be safely reused.
+ */
+#define XFRM_OFFLOAD_FULL	4
 
 struct xfrm_userpolicy_default {
 #define XFRM_USERPOLICY_UNSPEC	0

net/xfrm/xfrm_device.c +3 -0

index 5f5aafd418af..7c4e0f14df27 100644
@@ -278,12 +278,15 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 	else
 		xso->dir = XFRM_DEV_OFFLOAD_OUT;
 
+	xso->type = XFRM_DEV_OFFLOAD_CRYPTO;
+
 	err = dev->xfrmdev_ops->xdo_dev_state_add(x);
 	if (err) {
 		xso->dev = NULL;
 		xso->dir = 0;
 		xso->real_dev = NULL;
 		netdev_put(dev, &xso->dev_tracker);
+		xso->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
 
 		if (err != -EOPNOTSUPP) {
 			NL_SET_ERR_MSG(extack, "Device failed to offload this state");

net/xfrm/xfrm_user.c +2 -0

index e73f9efc54c1..bea2d4647a90 100644
@@ -943,6 +943,8 @@ static int copy_user_offload(struct xfrm_dev_offload *xso, struct sk_buff *skb)
 	xuo->ifindex = xso->dev->ifindex;
 	if (xso->dir == XFRM_DEV_OFFLOAD_IN)
 		xuo->flags = XFRM_OFFLOAD_INBOUND;
+	if (xso->type == XFRM_DEV_OFFLOAD_FULL)
+		xuo->flags |= XFRM_OFFLOAD_FULL;
 
 	return 0;
 }

Signature · 1 line

2.37.3

Leon Romanovsky

author

2022-10-23 12:06 UTC #2 lore raw

PATCH v5 2/8 xfrm: allow state full offload mode

In reply to Leon Romanovsky

From: Leon Romanovsky <[email protected]>

Allow users to configure xfrm states with full offload mode. The full mode must be requested both for policy and state, and such requires us to do not implement fallback.

We explicitly return an error if requested full mode can't be configured.

Reviewed-by Raed Salem <[email protected]>

Signed-off-by Leon Romanovsky <[email protected]>

---
 .../inline_crypto/ch_ipsec/chcr_ipsec.c       |  4 ++++
 .../net/ethernet/intel/ixgbe/ixgbe_ipsec.c    |  5 ++++
 drivers/net/ethernet/intel/ixgbevf/ipsec.c    |  5 ++++
 .../mellanox/mlx5/core/en_accel/ipsec.c       |  4 ++++
 drivers/net/netdevsim/ipsec.c                 |  5 ++++
 net/xfrm/xfrm_device.c                        | 24 +++++++++++++++----
 6 files changed, 42 insertions(+), 5 deletions(-)

drivers/net/ethernet/chelsio/inline_crypto/ch_ipsec/chcr_ipsec.c +4 -0

index 585590520076..ca21794281d6 100644
@@ -283,6 +283,10 @@ static int ch_ipsec_xfrm_add_state(struct xfrm_state *x)
 		pr_debug("Cannot offload xfrm states with geniv other than seqiv\n");
 		return -EINVAL;
 	}
+	if (x->xso.type != XFRM_DEV_OFFLOAD_CRYPTO) {
+		pr_debug("Unsupported xfrm offload\n");
+		return -EINVAL;
+	}
 
 	sa_entry = kzalloc(sizeof(*sa_entry), GFP_KERNEL);
 	if (!sa_entry) {

drivers/net/ethernet/intel/ixgbe/ixgbe_ipsec.c +5 -0

index 774de63dd93a..53a969e34883 100644
@@ -585,6 +585,11 @@ static int ixgbe_ipsec_add_sa(struct xfrm_state *xs)
 		return -EINVAL;
 	}
 
+	if (xs->xso.type != XFRM_DEV_OFFLOAD_CRYPTO) {
+		netdev_err(dev, "Unsupported ipsec offload type\n");
+		return -EINVAL;
+	}
+
 	if (xs->xso.dir == XFRM_DEV_OFFLOAD_IN) {
 		struct rx_sa rsa;

drivers/net/ethernet/intel/ixgbevf/ipsec.c +5 -0

index 9984ebc62d78..c1cf540d162a 100644
@@ -280,6 +280,11 @@ static int ixgbevf_ipsec_add_sa(struct xfrm_state *xs)
 		return -EINVAL;
 	}
 
+	if (xs->xso.type != XFRM_DEV_OFFLOAD_CRYPTO) {
+		netdev_err(dev, "Unsupported ipsec offload type\n");
+		return -EINVAL;
+	}
+
 	if (xs->xso.dir == XFRM_DEV_OFFLOAD_IN) {
 		struct rx_sa rsa;

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec.c +4 -0

index 325b56ff3e8c..1d8ce116946d 100644
@@ -256,6 +256,10 @@ static inline int mlx5e_xfrm_validate_state(struct xfrm_state *x)
 		netdev_info(netdev, "Cannot offload xfrm states with geniv other than seqiv\n");
 		return -EINVAL;
 	}
+	if (x->xso.type != XFRM_DEV_OFFLOAD_CRYPTO) {
+		netdev_info(netdev, "Unsupported xfrm offload type\n");
+		return -EINVAL;
+	}
 	return 0;
 }

drivers/net/netdevsim/ipsec.c +5 -0

index 386336a38f34..b93baf5c8bee 100644
@@ -149,6 +149,11 @@ static int nsim_ipsec_add_sa(struct xfrm_state *xs)
 		return -EINVAL;
 	}
 
+	if (xs->xso.type != XFRM_DEV_OFFLOAD_CRYPTO) {
+		netdev_err(dev, "Unsupported ipsec offload type\n");
+		return -EINVAL;
+	}
+
 	/* find the first unused index */
 	ret = nsim_ipsec_find_empty_idx(ipsec);
 	if (ret < 0) {

net/xfrm/xfrm_device.c +19 -5

index 7c4e0f14df27..1294e0490270 100644
@@ -216,6 +216,7 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 	struct xfrm_dev_offload *xso = &x->xso;
 	xfrm_address_t *saddr;
 	xfrm_address_t *daddr;
+	bool is_full_offload;
 
 	if (!x->type_offload) {
 		NL_SET_ERR_MSG(extack, "Type doesn't support offload");

@@ -228,11 +229,13 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 		return -EINVAL;
 	}
 
-	if (xuo->flags & ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND)) {
+	if (xuo->flags &
+	    ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND | XFRM_OFFLOAD_FULL)) {
 		NL_SET_ERR_MSG(extack, "Unrecognized flags in offload request");
 		return -EINVAL;
 	}
 
+	is_full_offload = xuo->flags & XFRM_OFFLOAD_FULL;
 	dev = dev_get_by_index(net, xuo->ifindex);
 	if (!dev) {
 		if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) {

@@ -247,7 +250,7 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 					x->props.family,
 					xfrm_smark_get(0, x));
 		if (IS_ERR(dst))
-			return 0;
+			return (is_full_offload) ? -EINVAL : 0;
 
 		dev = dst->dev;

@@ -258,7 +261,7 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 	if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) {
 		xso->dev = NULL;
 		dev_put(dev);
-		return 0;
+		return (is_full_offload) ? -EINVAL : 0;
 	}
 
 	if (x->props.flags & XFRM_STATE_ESN &&

@@ -278,7 +281,10 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 	else
 		xso->dir = XFRM_DEV_OFFLOAD_OUT;
 
-	xso->type = XFRM_DEV_OFFLOAD_CRYPTO;
+	if (is_full_offload)
+		xso->type = XFRM_DEV_OFFLOAD_FULL;
+	else
+		xso->type = XFRM_DEV_OFFLOAD_CRYPTO;
 
 	err = dev->xfrmdev_ops->xdo_dev_state_add(x);
 	if (err) {

@@ -288,7 +294,15 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
 		netdev_put(dev, &xso->dev_tracker);
 		xso->type = XFRM_DEV_OFFLOAD_UNSPECIFIED;
 
-		if (err != -EOPNOTSUPP) {
+		/* User explicitly requested full offload mode and configured
+		 * policy in addition to the XFRM state. So be civil to users,
+		 * and return an error instead of taking fallback path.
+		 *
+		 * This WARN_ON() can be seen as a documentation for driver
+		 * authors to do not return -EOPNOTSUPP in full offload mode.
+		 */
+		WARN_ON(err == -EOPNOTSUPP && is_full_offload);
+		if (err != -EOPNOTSUPP || is_full_offload) {
 			NL_SET_ERR_MSG(extack, "Device failed to offload this state");
 			return err;
 		}

Signature · 1 line

2.37.3

Leon Romanovsky

author

2022-10-23 12:06 UTC #3 lore raw

PATCH v5 3/8 xfrm: add an interface to offload policy

In reply to Leon Romanovsky

From: Leon Romanovsky <[email protected]>

Extend netlink interface to add and delete XFRM policy from the device. This functionality is a first step to implement full IPsec offload solution.

Signed-off-by Raed Salem <[email protected]>

Signed-off-by Leon Romanovsky <[email protected]>

---
 include/linux/netdevice.h |  3 ++
 include/net/xfrm.h        | 44 +++++++++++++++++++++++++
 net/xfrm/xfrm_device.c    | 67 +++++++++++++++++++++++++++++++++++++-
 net/xfrm/xfrm_policy.c    | 68 +++++++++++++++++++++++++++++++++++++++
 net/xfrm/xfrm_user.c      | 18 +++++++++++
 5 files changed, 199 insertions(+), 1 deletion(-)

include/linux/netdevice.h +3 -0

index a36edb0ec199..169387b2e104 100644
@@ -1033,6 +1033,9 @@ struct xfrmdev_ops {
 	bool	(*xdo_dev_offload_ok) (struct sk_buff *skb,
 				       struct xfrm_state *x);
 	void	(*xdo_dev_state_advance_esn) (struct xfrm_state *x);
+	int	(*xdo_dev_policy_add) (struct xfrm_policy *x);
+	void	(*xdo_dev_policy_delete) (struct xfrm_policy *x);
+	void	(*xdo_dev_policy_free) (struct xfrm_policy *x);
 };
 #endif

include/net/xfrm.h +44 -0

80 lines not on this page · raw message

net/xfrm/xfrm_device.c +66 -1

80 lines not on this page · raw message

net/xfrm/xfrm_policy.c +68 -0

98 lines not on this page · raw message

net/xfrm/xfrm_user.c +18 -0

index bea2d4647a90..8d7adeeaffbf 100644
@@ -1869,6 +1869,15 @@ static struct xfrm_policy *xfrm_policy_construct(struct net *net,
 	if (attrs[XFRMA_IF_ID])
 		xp->if_id = nla_get_u32(attrs[XFRMA_IF_ID]);
 
+	/* configure the hardware if offload is requested */
+	if (attrs[XFRMA_OFFLOAD_DEV]) {
+		err = xfrm_dev_policy_add(net, xp,
+					  nla_data(attrs[XFRMA_OFFLOAD_DEV]),
+					  p->dir, extack);
+		if (err)
+			goto error;
+	}
+
 	return xp;
  error:
 	*errp = err;

@@ -1908,6 +1917,7 @@ static int xfrm_add_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
 	xfrm_audit_policy_add(xp, err ? 0 : 1, true);
 
 	if (err) {
+		xfrm_dev_policy_delete(xp);
 		security_xfrm_policy_free(xp->security);
 		kfree(xp);
 		return err;

@@ -2020,6 +2030,8 @@ static int dump_one_policy(struct xfrm_policy *xp, int dir, int count, void *ptr
 		err = xfrm_mark_put(skb, &xp->mark);
 	if (!err)
 		err = xfrm_if_id_put(skb, xp->if_id);
+	if (!err && xp->xdo.dev)
+		err = copy_user_offload(&xp->xdo, skb);
 	if (err) {
 		nlmsg_cancel(skb, nlh);
 		return err;

@@ -3343,6 +3355,8 @@ static int build_acquire(struct sk_buff *skb, struct xfrm_state *x,
 		err = xfrm_mark_put(skb, &xp->mark);
 	if (!err)
 		err = xfrm_if_id_put(skb, xp->if_id);
+	if (!err && xp->xdo.dev)
+		err = copy_user_offload(&xp->xdo, skb);
 	if (err) {
 		nlmsg_cancel(skb, nlh);
 		return err;

@@ -3461,6 +3475,8 @@ static int build_polexpire(struct sk_buff *skb, struct xfrm_policy *xp,
 		err = xfrm_mark_put(skb, &xp->mark);
 	if (!err)
 		err = xfrm_if_id_put(skb, xp->if_id);
+	if (!err && xp->xdo.dev)
+		err = copy_user_offload(&xp->xdo, skb);
 	if (err) {
 		nlmsg_cancel(skb, nlh);
 		return err;

@@ -3544,6 +3560,8 @@ static int xfrm_notify_policy(struct xfrm_policy *xp, int dir, const struct km_e
 		err = xfrm_mark_put(skb, &xp->mark);
 	if (!err)
 		err = xfrm_if_id_put(skb, xp->if_id);
+	if (!err && xp->xdo.dev)
+		err = copy_user_offload(&xp->xdo, skb);
 	if (err)
 		goto out_free_skb;

Signature · 1 line

2.37.3

Leon Romanovsky

author

2022-10-23 12:06 UTC #4 lore raw

PATCH v5 4/8 xfrm: add TX datapath support for IPsec full offload mode

In reply to Leon Romanovsky

From: Leon Romanovsky <[email protected]>

In IPsec full mode, the device is going to encrypt and encapsulate packets that are associated with offloaded policy. After successful policy lookup to indicate if packets should be offloaded or not, the stack forwards packets to the device to do the magic.

Signed-off-by Raed Salem <[email protected]>

Signed-off-by Huy Nguyen <[email protected]>

Signed-off-by Leon Romanovsky <[email protected]>

---
 net/xfrm/xfrm_device.c | 15 +++++++++++++--
 net/xfrm/xfrm_output.c | 12 +++++++++++-
 2 files changed, 24 insertions(+), 3 deletions(-)

net/xfrm/xfrm_device.c +13 -2

index b5c6a78fdac2..783750998e80 100644
@@ -120,6 +120,16 @@ struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t featur
 	if (xo->flags & XFRM_GRO || x->xso.dir == XFRM_DEV_OFFLOAD_IN)
 		return skb;
 
+	/* The packet was sent to HW IPsec full offload engine,
+	 * but to wrong device. Drop the packet, so it won't skip
+	 * XFRM stack.
+	 */
+	if (x->xso.type == XFRM_DEV_OFFLOAD_FULL && x->xso.dev != dev) {
+		kfree_skb(skb);
+		dev_core_stats_tx_dropped_inc(dev);
+		return NULL;
+	}
+
 	/* This skb was already validated on the upper/virtual dev */
 	if ((x->xso.dev != dev) && (x->xso.real_dev == dev))
 		return skb;

@@ -385,8 +395,9 @@ bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
 	if (!x->type_offload || x->encap)
 		return false;
 
-	if ((!dev || (dev == xfrm_dst_path(dst)->dev)) &&
-	    (!xdst->child->xfrm)) {
+	if (x->xso.type == XFRM_DEV_OFFLOAD_FULL ||
+	    ((!dev || (dev == xfrm_dst_path(dst)->dev)) &&
+	     !xdst->child->xfrm)) {
 		mtu = xfrm_state_mtu(x, xdst->child_mtu_cached);
 		if (skb->len <= mtu)
 			goto ok;

net/xfrm/xfrm_output.c +11 -1

index 9a5e79a38c67..dde009be8463 100644
@@ -494,7 +494,7 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
 	struct xfrm_state *x = dst->xfrm;
 	struct net *net = xs_net(x);
 
-	if (err <= 0)
+	if (err <= 0 || x->xso.type == XFRM_DEV_OFFLOAD_FULL)
 		goto resume;
 
 	do {

@@ -718,6 +718,16 @@ int xfrm_output(struct sock *sk, struct sk_buff *skb)
 		break;
 	}
 
+	if (x->xso.type == XFRM_DEV_OFFLOAD_FULL) {
+		if (!xfrm_dev_offload_ok(skb, x)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			kfree_skb(skb);
+			return -EHOSTUNREACH;
+		}
+
+		return xfrm_output_resume(sk, skb, 0);
+	}
+
 	secpath_reset(skb);
 
 	if (xfrm_dev_offload_ok(skb, x)) {

Signature · 1 line

2.37.3

Leon Romanovsky

author

2022-10-23 12:06 UTC #5 lore raw

PATCH v5 5/8 xfrm: add RX datapath protection for IPsec full offload mode

In reply to Leon Romanovsky

From: Leon Romanovsky <[email protected]>

Traffic received by device with enabled IPsec full offload should be forwarded to the stack only after decryption, packet headers and trailers removed.

Such packets are expected to be seen as normal (non-XFRM) ones, while not-supported packets should be dropped by the HW.

Reviewed-by Raed Salem <[email protected]>

Signed-off-by Leon Romanovsky <[email protected]>

---
 include/net/xfrm.h | 55 +++++++++++++++++++++++++++-------------------
 1 file changed, 32 insertions(+), 23 deletions(-)

include/net/xfrm.h +32 ~~-23~~

index faa754d9431a..976361976ed5 100644
@@ -1102,6 +1102,29 @@ xfrm_state_addr_cmp(const struct xfrm_tmpl *tmpl, const struct xfrm_state *x, un
 	return !0;
 }
 
+#ifdef CONFIG_XFRM
+static inline struct xfrm_state *xfrm_input_state(struct sk_buff *skb)
+{
+	struct sec_path *sp = skb_sec_path(skb);
+
+	return sp->xvec[sp->len - 1];
+}
+#endif
+
+static inline struct xfrm_offload *xfrm_offload(struct sk_buff *skb)
+{
+#ifdef CONFIG_XFRM
+	struct sec_path *sp = skb_sec_path(skb);
+
+	if (!sp || !sp->olen || sp->len != sp->olen)
+		return NULL;
+
+	return &sp->ovec[sp->olen - 1];
+#else
+	return NULL;
+#endif
+}
+
 #ifdef CONFIG_XFRM
 int __xfrm_policy_check(struct sock *, int dir, struct sk_buff *skb,
 			unsigned short family);

@@ -1133,10 +1156,19 @@ static inline int __xfrm_policy_check2(struct sock *sk, int dir,
 {
 	struct net *net = dev_net(skb->dev);
 	int ndir = dir | (reverse ? XFRM_POLICY_MASK + 1 : 0);
+	struct xfrm_offload *xo = xfrm_offload(skb);
+	struct xfrm_state *x;
 
 	if (sk && sk->sk_policy[XFRM_POLICY_IN])
 		return __xfrm_policy_check(sk, ndir, skb, family);
 
+	if (xo) {
+		x = xfrm_input_state(skb);
+		if (x->xso.type == XFRM_DEV_OFFLOAD_FULL)
+			return (xo->flags & CRYPTO_DONE) &&
+			       (xo->status & CRYPTO_SUCCESS);
+	}
+
 	return __xfrm_check_nopolicy(net, skb, dir) ||
 	       __xfrm_check_dev_nopolicy(skb, dir, family) ||
 	       __xfrm_policy_check(sk, ndir, skb, family);

@@ -1869,29 +1901,6 @@ static inline void xfrm_states_delete(struct xfrm_state **states, int n)
 }
 #endif
 
-#ifdef CONFIG_XFRM
-static inline struct xfrm_state *xfrm_input_state(struct sk_buff *skb)
-{
-	struct sec_path *sp = skb_sec_path(skb);
-
-	return sp->xvec[sp->len - 1];
-}
-#endif
-
-static inline struct xfrm_offload *xfrm_offload(struct sk_buff *skb)
-{
-#ifdef CONFIG_XFRM
-	struct sec_path *sp = skb_sec_path(skb);
-
-	if (!sp || !sp->olen || sp->len != sp->olen)
-		return NULL;
-
-	return &sp->ovec[sp->olen - 1];
-#else
-	return NULL;
-#endif
-}
-
 void __init xfrm_dev_init(void);
 
 #ifdef CONFIG_XFRM_OFFLOAD

Signature · 1 line

2.37.3

Leon Romanovsky

author

2022-10-23 12:06 UTC #6 lore raw

PATCH v5 6/8 xfrm: Speed-up lookup of HW policies

In reply to Leon Romanovsky

From: Leon Romanovsky <[email protected]>

Devices that implement IPsec full offload mode should offload policies too. In RX path, it causes to the situation that HW will always have higher priority over any SW policies.

In case specific policy is not found, we will continue with full lookup and check for existence of HW policies in inexact list.

HW policies are added to the head of SPD to ensure fast lookup, as XFRM iterates over all policies in the loop.

Signed-off-by Leon Romanovsky <[email protected]>

---
 net/xfrm/xfrm_policy.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

net/xfrm/xfrm_policy.c +7 -1

index b07ed169f501..aa73e630aef5 100644
@@ -1562,9 +1562,12 @@ static struct xfrm_policy *xfrm_policy_insert_list(struct hlist_head *chain,
 			break;
 	}
 
-	if (newpos)
+	if (newpos && policy->xdo.type != XFRM_DEV_OFFLOAD_FULL)
 		hlist_add_behind_rcu(&policy->bydst, &newpos->bydst);
 	else
+		/* Full offload policies are enteded
+		 * to the head to speed-up lookups.
+		 */
 		hlist_add_head_rcu(&policy->bydst, chain);
 
 	return delpol;

@@ -2180,6 +2183,9 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 			break;
 		}
 	}
+	if (!ret && ret->xdo.type == XFRM_DEV_OFFLOAD_FULL)
+		goto skip_inexact;
+
 	bin = xfrm_policy_inexact_lookup_rcu(net, type, family, dir, if_id);
 	if (!bin || !xfrm_policy_find_inexact_candidates(&cand, bin, saddr,
 							 daddr))

Signature · 1 line

2.37.3

Leon Romanovsky

author

2022-10-23 12:07 UTC #7 lore raw

PATCH v5 7/8 xfrm: add support to HW update soft and hard limits

In reply to Leon Romanovsky

From: Leon Romanovsky <[email protected]>

Both in RX and TX, the traffic that performs IPsec full offload transformation is accounted by HW. It is needed to properly handle hard limits that require to drop the packet.

It means that XFRM core needs to update internal counters with the one that accounted by the HW, so new callbacks are introduced in this patch.

In case of soft or hard limit is occurred, the driver should call to xfrm_state_check_expire() that will perform key rekeying exactly as done by XFRM core.

Signed-off-by Leon Romanovsky <[email protected]>

---
 include/linux/netdevice.h |  1 +
 include/net/xfrm.h        | 17 +++++++++++++++++
 net/xfrm/xfrm_output.c    |  1 -
 net/xfrm/xfrm_state.c     |  4 ++++
 4 files changed, 22 insertions(+), 1 deletion(-)

include/linux/netdevice.h +1 -0

index 169387b2e104..49d80295812f 100644
@@ -1033,6 +1033,7 @@ struct xfrmdev_ops {
 	bool	(*xdo_dev_offload_ok) (struct sk_buff *skb,
 				       struct xfrm_state *x);
 	void	(*xdo_dev_state_advance_esn) (struct xfrm_state *x);
+	void	(*xdo_dev_state_update_curlft) (struct xfrm_state *x);
 	int	(*xdo_dev_policy_add) (struct xfrm_policy *x);
 	void	(*xdo_dev_policy_delete) (struct xfrm_policy *x);
 	void	(*xdo_dev_policy_free) (struct xfrm_policy *x);

include/net/xfrm.h +17 -0

index 976361976ed5..41f8aaafe755 100644
@@ -1571,6 +1571,23 @@ struct xfrm_state *xfrm_stateonly_find(struct net *net, u32 mark, u32 if_id,
 struct xfrm_state *xfrm_state_lookup_byspi(struct net *net, __be32 spi,
 					      unsigned short family);
 int xfrm_state_check_expire(struct xfrm_state *x);
+#ifdef CONFIG_XFRM_OFFLOAD
+static inline void xfrm_dev_state_update_curlft(struct xfrm_state *x)
+{
+	struct xfrm_dev_offload *xdo = &x->xso;
+	struct net_device *dev = xdo->dev;
+
+	if (x->xso.type != XFRM_DEV_OFFLOAD_FULL)
+		return;
+
+	if (dev && dev->xfrmdev_ops &&
+	    dev->xfrmdev_ops->xdo_dev_state_update_curlft)
+		dev->xfrmdev_ops->xdo_dev_state_update_curlft(x);
+
+}
+#else
+static inline void xfrm_dev_state_update_curlft(struct xfrm_state *x) {}
+#endif
 void xfrm_state_insert(struct xfrm_state *x);
 int xfrm_state_add(struct xfrm_state *x);
 int xfrm_state_update(struct xfrm_state *x);

net/xfrm/xfrm_output.c +0 -1

index dde009be8463..a22033350ddc 100644
@@ -560,7 +560,6 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
 			goto error_nolock;
 		}
-
 		dst = skb_dst_pop(skb);
 		if (!dst) {
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);

net/xfrm/xfrm_state.c +4 -0

index 81df34b3da6e..f2d31eeef193 100644
@@ -549,6 +549,8 @@ static enum hrtimer_restart xfrm_timer_handler(struct hrtimer *me)
 	int err = 0;
 
 	spin_lock(&x->lock);
+	xfrm_dev_state_update_curlft(x);
+
 	if (x->km.state == XFRM_STATE_DEAD)
 		goto out;
 	if (x->km.state == XFRM_STATE_EXPIRED)

@@ -1786,6 +1788,8 @@ EXPORT_SYMBOL(xfrm_state_update);
 
 int xfrm_state_check_expire(struct xfrm_state *x)
 {
+	xfrm_dev_state_update_curlft(x);
+
 	if (!x->curlft.use_time)
 		x->curlft.use_time = ktime_get_real_seconds();

Signature · 1 line

2.37.3

Leon Romanovsky

author

2022-10-23 12:07 UTC #8 lore raw

PATCH v5 8/8 xfrm: document IPsec full offload mode

In reply to Leon Romanovsky

From: Leon Romanovsky <[email protected]>

Extend XFRM device offload API description with newly added full offload mode.

Signed-off-by Leon Romanovsky <[email protected]>

---
 Documentation/networking/xfrm_device.rst | 62 ++++++++++++++++++++----
 1 file changed, 53 insertions(+), 9 deletions(-)

Documentation/networking/xfrm_device.rst +53 -9

index 01391dfd37d9..499f9d4ca021 100644
@@ -5,6 +5,7 @@ XFRM device - offloading the IPsec computations
 ===============================================
 
 Shannon Nelson <[email protected]>
+Leon Romanovsky <[email protected]>
 
 
 Overview

@@ -18,10 +19,21 @@ can radically increase throughput and decrease CPU utilization.  The XFRM
 Device interface allows NIC drivers to offer to the stack access to the
 hardware offload.
 
+Right now, there are two types of hardware offload that kernel supports.
+ * IPsec crypto offload:
+   * NIC performs encrypt/decrypt
+   * Kernel does everything else
+ * IPsec full offload:
+   * NIC performs encrypt/decrypt
+   * NIC does encapsulation
+   * Kernel and NIC have SA and policy in-sync
+   * NIC handles the SA and policies states
+   * The Kernel talks to the keymanager
+
 Userland access to the offload is typically through a system such as
 libreswan or KAME/raccoon, but the iproute2 'ip xfrm' command set can
 be handy when experimenting.  An example command might look something
-like this::
+like this for crypto offload:
 
   ip x s add proto esp dst 14.0.0.70 src 14.0.0.52 spi 0x07 mode transport \
      reqid 0x07 replay-window 32 \

@@ -29,6 +41,17 @@ like this::
      sel src 14.0.0.52/24 dst 14.0.0.70/24 proto tcp \
      offload dev eth4 dir in
 
+and for full offload
+
+  ip x s add proto esp dst 14.0.0.70 src 14.0.0.52 spi 0x07 mode transport \
+     reqid 0x07 replay-window 32 \
+     aead 'rfc4106(gcm(aes))' 0x44434241343332312423222114131211f4f3f2f1 128 \
+     sel src 14.0.0.52/24 dst 14.0.0.70/24 proto tcp \
+     offload full dev eth4 dir in
+
+  ip x p add src 14.0.0.70 dst 14.0.0.52 offload full dev eth4 dir in
+  tmpl src 14.0.0.70 dst 14.0.0.52 proto esp reqid 10000 mode transport
+
 Yes, that's ugly, but that's what shell scripts and/or libreswan are for.

@@ -40,17 +63,24 @@ Callbacks to implement
 
   /* from include/linux/netdevice.h */
   struct xfrmdev_ops {
+        /* Crypto and Full offload callbacks */
 	int	(*xdo_dev_state_add) (struct xfrm_state *x);
 	void	(*xdo_dev_state_delete) (struct xfrm_state *x);
 	void	(*xdo_dev_state_free) (struct xfrm_state *x);
 	bool	(*xdo_dev_offload_ok) (struct sk_buff *skb,
 				       struct xfrm_state *x);
 	void    (*xdo_dev_state_advance_esn) (struct xfrm_state *x);
+
+        /* Solely full offload callbacks */
+	void    (*xdo_dev_state_update_curlft) (struct xfrm_state *x);
+	int	(*xdo_dev_policy_add) (struct xfrm_policy *x);
+	void	(*xdo_dev_policy_delete) (struct xfrm_policy *x);
+	void	(*xdo_dev_policy_free) (struct xfrm_policy *x);
   };
 
-The NIC driver offering ipsec offload will need to implement these
-callbacks to make the offload available to the network stack's
-XFRM subsystem.  Additionally, the feature bits NETIF_F_HW_ESP and
+The NIC driver offering ipsec offload will need to implement callbacks
+relevant to supported offload to make the offload available to the network
+stack's XFRM subsystem. Additionally, the feature bits NETIF_F_HW_ESP and
 NETIF_F_HW_ESP_TX_CSUM will signal the availability of the offload.

@@ -79,7 +109,8 @@ and an indication of whether it is for Rx or Tx.  The driver should
 
 		===========   ===================================
 		0             success
-		-EOPNETSUPP   offload not supported, try SW IPsec
+		-EOPNETSUPP   offload not supported, try SW IPsec,
+                              not applicable for full offload mode
 		other         fail the request
 		===========   ===================================

@@ -96,6 +127,7 @@ will serviceable.  This can check the packet information to be sure the
 offload can be supported (e.g. IPv4 or IPv6, no IPv4 options, etc) and
 return true of false to signify its support.
 
+Crypto offload mode:
 When ready to send, the driver needs to inspect the Tx packet for the
 offload information, including the opaque context, and set up the packet
 send accordingly::

@@ -139,13 +171,25 @@ the stack in xfrm_input().
 In ESN mode, xdo_dev_state_advance_esn() is called from xfrm_replay_advance_esn().
 Driver will check packet seq number and update HW ESN state machine if needed.
 
+Full offload mode:
+HW adds and deletes XFRM headers. So in RX path, XFRM stack is bypassed if HW
+reported success. In TX path, the packet lefts kernel without extra header
+and not encrypted, the HW is responsible to perform it.
+
 When the SA is removed by the user, the driver's xdo_dev_state_delete()
-is asked to disable the offload.  Later, xdo_dev_state_free() is called
-from a garbage collection routine after all reference counts to the state
+and xdo_dev_policy_delete() are asked to disable the offload.  Later,
+xdo_dev_state_free() and xdo_dev_policy_free() are called from a garbage
+collection routine after all reference counts to the state and policy
 have been removed and any remaining resources can be cleared for the
 offload state.  How these are used by the driver will depend on specific
 hardware needs.
 
 As a netdev is set to DOWN the XFRM stack's netdev listener will call
-xdo_dev_state_delete() and xdo_dev_state_free() on any remaining offloaded
-states.
+xdo_dev_state_delete(), xdo_dev_policy_delete(), xdo_dev_state_free() and
+xdo_dev_policy_free() on any remaining offloaded states.
+
+Outcome of HW handling packets, the XFRM core can't count hard, soft limits.
+The HW/driver are responsible to perform it and provide accurate data when
+xdo_dev_state_update_curlft() is called. In case of one of these limits
+occuried, the driver needs to call to xfrm_state_check_expire() to make sure
+that XFRM performs rekeying sequence.

Signature · 1 line

2.37.3