xfrm: Add an IPsec hardware offloading API

This patch adds all the bits that are needed to do
IPsec hardware offload for IPsec states and ESP packets.
We add xfrmdev_ops to the net_device. xfrmdev_ops has
function pointers that are needed to manage the xfrm
states in the hardware and to do a per packet
offloading decision.

Joint work with:
Ilan Tayari <ilant@mellanox.com>
Guy Shapiro <guysh@mellanox.com>
Yossi Kuperman <yossiku@mellanox.com>

Signed-off-by: Guy Shapiro <guysh@mellanox.com>
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

3 files changed, 86 insertions, 1 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 5bb03d181848..b3eb83db0223 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -824,6 +824,16 @@ struct netdev_xdp {
 	};
 };
 
+#ifdef CONFIG_XFRM_OFFLOAD
+struct xfrmdev_ops {
+	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);
+};
+#endif
+
 /*
  * This structure defines the management hooks for network devices.
  * The following hooks can be defined; unless noted otherwise, they are
@@ -1697,6 +1707,10 @@ struct net_device {
 	const struct ndisc_ops *ndisc_ops;
 #endif
 
+#ifdef CONFIG_XFRM
+	const struct xfrmdev_ops *xfrmdev_ops;
+#endif
+
 	const struct header_ops *header_ops;
 
 	unsigned int		flags;
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 54515d989365..17603bf190c1 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -120,6 +120,13 @@ struct xfrm_state_walk {
 	struct xfrm_address_filter *filter;
 };
 
+struct xfrm_state_offload {
+	struct net_device	*dev;
+	unsigned long		offload_handle;
+	unsigned int		num_exthdrs;
+	u8			flags;
+};
+
 /* Full description of state of transformer. */
 struct xfrm_state {
 	possible_net_t		xs_net;
@@ -207,6 +214,8 @@ struct xfrm_state {
 	struct xfrm_lifetime_cur curlft;
 	struct tasklet_hrtimer	mtimer;
 
+	struct xfrm_state_offload xso;
+
 	/* used to fix curlft->add_time when changing date */
 	long		saved_tmo;
 
@@ -1453,7 +1462,6 @@ struct xfrm6_tunnel {
 void xfrm_init(void);
 void xfrm4_init(void);
 int xfrm_state_init(struct net *net);
-void xfrm_dev_init(void);
 void xfrm_state_fini(struct net *net);
 void xfrm4_state_init(void);
 void xfrm4_protocol_init(void);
@@ -1559,6 +1567,7 @@ struct xfrmk_spdinfo {
 struct xfrm_state *xfrm_find_acq_byseq(struct net *net, u32 mark, u32 seq);
 int xfrm_state_delete(struct xfrm_state *x);
 int xfrm_state_flush(struct net *net, u8 proto, bool task_valid);
+int xfrm_dev_state_flush(struct net *net, struct net_device *dev, bool task_valid);
 void xfrm_sad_getinfo(struct net *net, struct xfrmk_sadinfo *si);
 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si);
 u32 xfrm_replay_seqhi(struct xfrm_state *x, __be32 net_seq);
@@ -1641,6 +1650,11 @@ static inline int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb)
 }
 #endif
 
+struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos, int oif,
+				    const xfrm_address_t *saddr,
+				    const xfrm_address_t *daddr,
+				    int family);
+
 struct xfrm_policy *xfrm_policy_alloc(struct net *net, gfp_t gfp);
 
 void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type);
@@ -1846,6 +1860,55 @@ static inline struct xfrm_offload *xfrm_offload(struct sk_buff *skb)
 }
 #endif
 
+#ifdef CONFIG_XFRM_OFFLOAD
+void __net_init xfrm_dev_init(void);
+int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
+		       struct xfrm_user_offload *xuo);
+bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x);
+
+static inline void xfrm_dev_state_delete(struct xfrm_state *x)
+{
+	struct xfrm_state_offload *xso = &x->xso;
+
+	if (xso->dev)
+		xso->dev->xfrmdev_ops->xdo_dev_state_delete(x);
+}
+
+static inline void xfrm_dev_state_free(struct xfrm_state *x)
+{
+	struct xfrm_state_offload *xso = &x->xso;
+	 struct net_device *dev = xso->dev;
+
+	if (dev && dev->xfrmdev_ops) {
+		dev->xfrmdev_ops->xdo_dev_state_free(x);
+		xso->dev = NULL;
+		dev_put(dev);
+	}
+}
+#else
+static inline void __net_init xfrm_dev_init(void)
+{
+}
+
+static inline int xfrm_dev_state_add(struct net *net, struct xfrm_state *x, struct xfrm_user_offload *xuo)
+{
+	return 0;
+}
+
+static inline void xfrm_dev_state_delete(struct xfrm_state *x)
+{
+}
+
+static inline void xfrm_dev_state_free(struct xfrm_state *x)
+{
+}
+
+static inline bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
+{
+	return false;
+}
+#endif
+
 static inline int xfrm_mark_get(struct nlattr **attrs, struct xfrm_mark *m)
 {
 	if (attrs[XFRMA_MARK])
diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
index 1fc62b239f1b..2b384ff09fa0 100644
--- a/include/uapi/linux/xfrm.h
+++ b/include/uapi/linux/xfrm.h
@@ -303,6 +303,7 @@ enum xfrm_attr_type_t {
 	XFRMA_PROTO,		/* __u8 */
 	XFRMA_ADDRESS_FILTER,	/* struct xfrm_address_filter */
 	XFRMA_PAD,
+	XFRMA_OFFLOAD_DEV,	/* struct xfrm_state_offload */
 	__XFRMA_MAX
 
 #define XFRMA_MAX (__XFRMA_MAX - 1)
@@ -494,6 +495,13 @@ struct xfrm_address_filter {
 	__u8				dplen;
 };
 
+struct xfrm_user_offload {
+	int				ifindex;
+	__u8				flags;
+};
+#define XFRM_OFFLOAD_IPV6	1
+#define XFRM_OFFLOAD_INBOUND	2
+
 #ifndef __KERNEL__
 /* backwards compatibility for userspace */
 #define XFRMGRP_ACQUIRE		1