1 files changed, 442 insertions, 0 deletions

diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
new file mode 100644
index 000000000..8b8e957a6
--- /dev/null
+++ b/net/xfrm/xfrm_device.c
@@ -0,0 +1,442 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * xfrm_device.c - IPsec device offloading code.
+ *
+ * Copyright (c) 2015 secunet Security Networks AG
+ *
+ * Author:
+ * Steffen Klassert <steffen.klassert@secunet.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <net/dst.h>
+#include <net/xfrm.h>
+#include <linux/notifier.h>
+
+#ifdef CONFIG_XFRM_OFFLOAD
+static void __xfrm_transport_prep(struct xfrm_state *x, struct sk_buff *skb,
+				  unsigned int hsize)
+{
+	struct xfrm_offload *xo = xfrm_offload(skb);
+
+	skb_reset_mac_len(skb);
+	if (xo->flags & XFRM_GSO_SEGMENT)
+		skb->transport_header -= x->props.header_len;
+
+	pskb_pull(skb, skb_transport_offset(skb) + x->props.header_len);
+}
+
+static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb,
+				    unsigned int hsize)
+
+{
+	struct xfrm_offload *xo = xfrm_offload(skb);
+
+	if (xo->flags & XFRM_GSO_SEGMENT)
+		skb->transport_header = skb->network_header + hsize;
+
+	skb_reset_mac_len(skb);
+	pskb_pull(skb, skb->mac_len + x->props.header_len);
+}
+
+static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb,
+				  unsigned int hsize)
+{
+	struct xfrm_offload *xo = xfrm_offload(skb);
+	int phlen = 0;
+
+	if (xo->flags & XFRM_GSO_SEGMENT)
+		skb->transport_header = skb->network_header + hsize;
+
+	skb_reset_mac_len(skb);
+	if (x->sel.family != AF_INET6) {
+		phlen = IPV4_BEET_PHMAXLEN;
+		if (x->outer_mode.family == AF_INET6)
+			phlen += sizeof(struct ipv6hdr) - sizeof(struct iphdr);
+	}
+
+	pskb_pull(skb, skb->mac_len + hsize + (x->props.header_len - phlen));
+}
+
+/* Adjust pointers into the packet when IPsec is done at layer2 */
+static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
+{
+	switch (x->outer_mode.encap) {
+	case XFRM_MODE_TUNNEL:
+		if (x->outer_mode.family == AF_INET)
+			return __xfrm_mode_tunnel_prep(x, skb,
+						       sizeof(struct iphdr));
+		if (x->outer_mode.family == AF_INET6)
+			return __xfrm_mode_tunnel_prep(x, skb,
+						       sizeof(struct ipv6hdr));
+		break;
+	case XFRM_MODE_TRANSPORT:
+		if (x->outer_mode.family == AF_INET)
+			return __xfrm_transport_prep(x, skb,
+						     sizeof(struct iphdr));
+		if (x->outer_mode.family == AF_INET6)
+			return __xfrm_transport_prep(x, skb,
+						     sizeof(struct ipv6hdr));
+		break;
+	case XFRM_MODE_BEET:
+		if (x->outer_mode.family == AF_INET)
+			return __xfrm_mode_beet_prep(x, skb,
+						     sizeof(struct iphdr));
+		if (x->outer_mode.family == AF_INET6)
+			return __xfrm_mode_beet_prep(x, skb,
+						     sizeof(struct ipv6hdr));
+		break;
+	case XFRM_MODE_ROUTEOPTIMIZATION:
+	case XFRM_MODE_IN_TRIGGER:
+		break;
+	}
+}
+
+static inline bool xmit_xfrm_check_overflow(struct sk_buff *skb)
+{
+	struct xfrm_offload *xo = xfrm_offload(skb);
+	__u32 seq = xo->seq.low;
+
+	seq += skb_shinfo(skb)->gso_segs;
+	if (unlikely(seq < xo->seq.low))
+		return true;
+
+	return false;
+}
+
+struct sk_buff *validate_xmit_xfrm(struct sk_buff *skb, netdev_features_t features, bool *again)
+{
+	int err;
+	unsigned long flags;
+	struct xfrm_state *x;
+	struct softnet_data *sd;
+	struct sk_buff *skb2, *nskb, *pskb = NULL;
+	netdev_features_t esp_features = features;
+	struct xfrm_offload *xo = xfrm_offload(skb);
+	struct net_device *dev = skb->dev;
+	struct sec_path *sp;
+
+	if (!xo || (xo->flags & XFRM_XMIT))
+		return skb;
+
+	if (!(features & NETIF_F_HW_ESP))
+		esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK);
+
+	sp = skb_sec_path(skb);
+	x = sp->xvec[sp->len - 1];
+	if (xo->flags & XFRM_GRO || x->xso.flags & XFRM_OFFLOAD_INBOUND)
+		return skb;
+
+	/* This skb was already validated on the upper/virtual dev */
+	if ((x->xso.dev != dev) && (x->xso.real_dev == dev))
+		return skb;
+
+	local_irq_save(flags);
+	sd = this_cpu_ptr(&softnet_data);
+	err = !skb_queue_empty(&sd->xfrm_backlog);
+	local_irq_restore(flags);
+
+	if (err) {
+		*again = true;
+		return skb;
+	}
+
+	if (skb_is_gso(skb) && (unlikely(x->xso.dev != dev) ||
+				unlikely(xmit_xfrm_check_overflow(skb)))) {
+		struct sk_buff *segs;
+
+		/* Packet got rerouted, fixup features and segment it. */
+		esp_features = esp_features & ~(NETIF_F_HW_ESP | NETIF_F_GSO_ESP);
+
+		segs = skb_gso_segment(skb, esp_features);
+		if (IS_ERR(segs)) {
+			kfree_skb(skb);
+			atomic_long_inc(&dev->tx_dropped);
+			return NULL;
+		} else {
+			consume_skb(skb);
+			skb = segs;
+		}
+	}
+
+	if (!skb->next) {
+		esp_features |= skb->dev->gso_partial_features;
+		xfrm_outer_mode_prep(x, skb);
+
+		xo->flags |= XFRM_DEV_RESUME;
+
+		err = x->type_offload->xmit(x, skb, esp_features);
+		if (err) {
+			if (err == -EINPROGRESS)
+				return NULL;
+
+			XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
+			kfree_skb(skb);
+			return NULL;
+		}
+
+		skb_push(skb, skb->data - skb_mac_header(skb));
+
+		return skb;
+	}
+
+	skb_list_walk_safe(skb, skb2, nskb) {
+		esp_features |= skb->dev->gso_partial_features;
+		skb_mark_not_on_list(skb2);
+
+		xo = xfrm_offload(skb2);
+		xo->flags |= XFRM_DEV_RESUME;
+
+		xfrm_outer_mode_prep(x, skb2);
+
+		err = x->type_offload->xmit(x, skb2, esp_features);
+		if (!err) {
+			skb2->next = nskb;
+		} else if (err != -EINPROGRESS) {
+			XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
+			skb2->next = nskb;
+			kfree_skb_list(skb2);
+			return NULL;
+		} else {
+			if (skb == skb2)
+				skb = nskb;
+			else
+				pskb->next = nskb;
+
+			continue;
+		}
+
+		skb_push(skb2, skb2->data - skb_mac_header(skb2));
+		pskb = skb2;
+	}
+
+	return skb;
+}
+EXPORT_SYMBOL_GPL(validate_xmit_xfrm);
+
+int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
+		       struct xfrm_user_offload *xuo)
+{
+	int err;
+	struct dst_entry *dst;
+	struct net_device *dev;
+	struct xfrm_state_offload *xso = &x->xso;
+	xfrm_address_t *saddr;
+	xfrm_address_t *daddr;
+
+	if (!x->type_offload)
+		return -EINVAL;
+
+	/* We don't yet support UDP encapsulation and TFC padding. */
+	if (x->encap || x->tfcpad)
+		return -EINVAL;
+
+	if (xuo->flags & ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND))
+		return -EINVAL;
+
+	dev = dev_get_by_index(net, xuo->ifindex);
+	if (!dev) {
+		if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) {
+			saddr = &x->props.saddr;
+			daddr = &x->id.daddr;
+		} else {
+			saddr = &x->id.daddr;
+			daddr = &x->props.saddr;
+		}
+
+		dst = __xfrm_dst_lookup(net, 0, 0, saddr, daddr,
+					x->props.family,
+					xfrm_smark_get(0, x));
+		if (IS_ERR(dst))
+			return 0;
+
+		dev = dst->dev;
+
+		dev_hold(dev);
+		dst_release(dst);
+	}
+
+	if (!dev->xfrmdev_ops || !dev->xfrmdev_ops->xdo_dev_state_add) {
+		xso->dev = NULL;
+		dev_put(dev);
+		return 0;
+	}
+
+	if (x->props.flags & XFRM_STATE_ESN &&
+	    !dev->xfrmdev_ops->xdo_dev_state_advance_esn) {
+		xso->dev = NULL;
+		dev_put(dev);
+		return -EINVAL;
+	}
+
+	xso->dev = dev;
+	xso->real_dev = dev;
+	xso->num_exthdrs = 1;
+	/* Don't forward bit that is not implemented */
+	xso->flags = xuo->flags & ~XFRM_OFFLOAD_IPV6;
+
+	err = dev->xfrmdev_ops->xdo_dev_state_add(x);
+	if (err) {
+		xso->num_exthdrs = 0;
+		xso->flags = 0;
+		xso->dev = NULL;
+		xso->real_dev = NULL;
+		dev_put(dev);
+
+		if (err != -EOPNOTSUPP)
+			return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(xfrm_dev_state_add);
+
+bool xfrm_dev_offload_ok(struct sk_buff *skb, struct xfrm_state *x)
+{
+	int mtu;
+	struct dst_entry *dst = skb_dst(skb);
+	struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
+	struct net_device *dev = x->xso.dev;
+
+	if (!x->type_offload || x->encap)
+		return false;
+
+	if ((!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;
+
+		if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
+			goto ok;
+	}
+
+	return false;
+
+ok:
+	if (dev && dev->xfrmdev_ops && dev->xfrmdev_ops->xdo_dev_offload_ok)
+		return x->xso.dev->xfrmdev_ops->xdo_dev_offload_ok(skb, x);
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(xfrm_dev_offload_ok);
+
+void xfrm_dev_resume(struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	int ret = NETDEV_TX_BUSY;
+	struct netdev_queue *txq;
+	struct softnet_data *sd;
+	unsigned long flags;
+
+	rcu_read_lock();
+	txq = netdev_core_pick_tx(dev, skb, NULL);
+
+	HARD_TX_LOCK(dev, txq, smp_processor_id());
+	if (!netif_xmit_frozen_or_stopped(txq))
+		skb = dev_hard_start_xmit(skb, dev, txq, &ret);
+	HARD_TX_UNLOCK(dev, txq);
+
+	if (!dev_xmit_complete(ret)) {
+		local_irq_save(flags);
+		sd = this_cpu_ptr(&softnet_data);
+		skb_queue_tail(&sd->xfrm_backlog, skb);
+		raise_softirq_irqoff(NET_TX_SOFTIRQ);
+		local_irq_restore(flags);
+	}
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(xfrm_dev_resume);
+
+void xfrm_dev_backlog(struct softnet_data *sd)
+{
+	struct sk_buff_head *xfrm_backlog = &sd->xfrm_backlog;
+	struct sk_buff_head list;
+	struct sk_buff *skb;
+
+	if (skb_queue_empty(xfrm_backlog))
+		return;
+
+	__skb_queue_head_init(&list);
+
+	spin_lock(&xfrm_backlog->lock);
+	skb_queue_splice_init(xfrm_backlog, &list);
+	spin_unlock(&xfrm_backlog->lock);
+
+	while (!skb_queue_empty(&list)) {
+		skb = __skb_dequeue(&list);
+		xfrm_dev_resume(skb);
+	}
+
+}
+#endif
+
+static int xfrm_api_check(struct net_device *dev)
+{
+#ifdef CONFIG_XFRM_OFFLOAD
+	if ((dev->features & NETIF_F_HW_ESP_TX_CSUM) &&
+	    !(dev->features & NETIF_F_HW_ESP))
+		return NOTIFY_BAD;
+
+	if ((dev->features & NETIF_F_HW_ESP) &&
+	    (!(dev->xfrmdev_ops &&
+	       dev->xfrmdev_ops->xdo_dev_state_add &&
+	       dev->xfrmdev_ops->xdo_dev_state_delete)))
+		return NOTIFY_BAD;
+#else
+	if (dev->features & (NETIF_F_HW_ESP | NETIF_F_HW_ESP_TX_CSUM))
+		return NOTIFY_BAD;
+#endif
+
+	return NOTIFY_DONE;
+}
+
+static int xfrm_dev_register(struct net_device *dev)
+{
+	return xfrm_api_check(dev);
+}
+
+static int xfrm_dev_feat_change(struct net_device *dev)
+{
+	return xfrm_api_check(dev);
+}
+
+static int xfrm_dev_down(struct net_device *dev)
+{
+	if (dev->features & NETIF_F_HW_ESP)
+		xfrm_dev_state_flush(dev_net(dev), dev, true);
+
+	return NOTIFY_DONE;
+}
+
+static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	switch (event) {
+	case NETDEV_REGISTER:
+		return xfrm_dev_register(dev);
+
+	case NETDEV_FEAT_CHANGE:
+		return xfrm_dev_feat_change(dev);
+
+	case NETDEV_DOWN:
+	case NETDEV_UNREGISTER:
+		return xfrm_dev_down(dev);
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block xfrm_dev_notifier = {
+	.notifier_call	= xfrm_dev_event,
+};
+
+void __init xfrm_dev_init(void)
+{
+	register_netdevice_notifier(&xfrm_dev_notifier);
+}