1 files changed, 421 insertions, 0 deletions

diff --git a/datapath/actions.c b/datapath/actions.c
new file mode 100644
index 000000000..30b840cbb
--- /dev/null
+++ b/datapath/actions.c
@@ -0,0 +1,421 @@
+/*
+ * Distributed under the terms of the GNU GPL version 2.
+ * Copyright (c) 2007, 2008, 2009 Nicira Networks.
+ */
+
+/* Functions for executing flow actions. */
+
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/in6.h>
+#include <linux/if_vlan.h>
+#include <net/ip.h>
+#include <net/checksum.h>
+#include "datapath.h"
+#include "dp_dev.h"
+#include "actions.h"
+#include "openvswitch/datapath-protocol.h"
+
+struct sk_buff *
+make_writable(struct sk_buff *skb, gfp_t gfp)
+{
+	if (skb_shared(skb) || skb_cloned(skb)) {
+		struct sk_buff *nskb = skb_copy(skb, gfp);
+		if (nskb) {
+			kfree_skb(skb);
+			return nskb;
+		}
+	} else {
+		unsigned int hdr_len = (skb_transport_offset(skb)
+					+ sizeof(struct tcphdr));
+		if (pskb_may_pull(skb, min(hdr_len, skb->len)))
+			return skb;
+	}
+	kfree_skb(skb);
+	return NULL;
+}
+
+
+static struct sk_buff *
+vlan_pull_tag(struct sk_buff *skb)
+{
+	struct vlan_ethhdr *vh = vlan_eth_hdr(skb);
+	struct ethhdr *eh;
+
+
+	/* Verify we were given a vlan packet */
+	if (vh->h_vlan_proto != htons(ETH_P_8021Q))
+		return skb;
+
+	memmove(skb->data + VLAN_HLEN, skb->data, 2 * VLAN_ETH_ALEN);
+
+	eh = (struct ethhdr *)skb_pull(skb, VLAN_HLEN);
+
+	skb->protocol = eh->h_proto;
+	skb->mac_header += VLAN_HLEN;
+
+	return skb;
+}
+
+
+static struct sk_buff *
+modify_vlan_tci(struct datapath *dp, struct sk_buff *skb,
+		struct odp_flow_key *key, const union odp_action *a,
+		int n_actions, gfp_t gfp)
+{
+	u16 tci, mask;
+
+	if (a->type == ODPAT_SET_VLAN_VID) {
+		tci = ntohs(a->vlan_vid.vlan_vid);
+		mask = VLAN_VID_MASK;
+		key->dl_vlan = htons(tci & mask);
+	} else {
+		tci = a->vlan_pcp.vlan_pcp << 13;
+		mask = VLAN_PCP_MASK;
+	}
+
+	skb = make_writable(skb, gfp);
+	if (!skb)
+		return ERR_PTR(-ENOMEM);
+
+	if (skb->protocol == htons(ETH_P_8021Q)) {
+		/* Modify vlan id, but maintain other TCI values */
+		struct vlan_ethhdr *vh = vlan_eth_hdr(skb);
+		vh->h_vlan_TCI = htons((ntohs(vh->h_vlan_TCI) & ~mask) | tci);
+	} else {
+		/* Add vlan header */
+
+		/* Set up checksumming pointers for checksum-deferred packets
+		 * on Xen.  Otherwise, dev_queue_xmit() will try to do this
+		 * when we send the packet out on the wire, and it will fail at
+		 * that point because skb_checksum_setup() will not look inside
+		 * an 802.1Q header. */
+		skb_checksum_setup(skb);
+
+		/* GSO is not implemented for packets with an 802.1Q header, so
+		 * we have to do segmentation before we add that header.
+		 *
+		 * GSO does work with hardware-accelerated VLAN tagging, but we
+		 * can't use hardware-accelerated VLAN tagging since it
+		 * requires the device to have a VLAN group configured (with
+		 * e.g. vconfig(8)) and we don't do that.
+		 *
+		 * Having to do this here may be a performance loss, since we
+		 * can't take advantage of TSO hardware support, although it
+		 * does not make a measurable network performance difference
+		 * for 1G Ethernet.  Fixing that would require patching the
+		 * kernel (either to add GSO support to the VLAN protocol or to
+		 * support hardware-accelerated VLAN tagging without VLAN
+		 * groups configured). */
+		if (skb_is_gso(skb)) {
+			struct sk_buff *segs;
+
+			segs = skb_gso_segment(skb, 0);
+			kfree_skb(skb);
+			if (unlikely(IS_ERR(segs)))
+				return ERR_CAST(segs);
+
+			do {
+				struct sk_buff *nskb = segs->next;
+				int err;
+
+				segs->next = NULL;
+
+				segs = __vlan_put_tag(segs, tci);
+				err = -ENOMEM;
+				if (segs) {
+					struct odp_flow_key segkey = *key;
+					err = execute_actions(dp, segs,
+							      &segkey, a + 1,
+							      n_actions - 1,
+							      gfp);
+				}
+
+				if (unlikely(err)) {
+					while ((segs = nskb)) {
+						nskb = segs->next;
+						segs->next = NULL;
+						kfree_skb(segs);
+					}
+					return ERR_PTR(err);
+				}
+
+				segs = nskb;
+			} while (segs->next);
+
+			skb = segs;
+		}
+
+		/* The hardware-accelerated version of vlan_put_tag() works
+		 * only for a device that has a VLAN group configured (with
+		 * e.g. vconfig(8)), so call the software-only version
+		 * __vlan_put_tag() directly instead.
+		 */
+		skb = __vlan_put_tag(skb, tci);
+		if (!skb)
+			return ERR_PTR(-ENOMEM);
+	}
+
+	return skb;
+}
+
+static struct sk_buff *strip_vlan(struct sk_buff *skb,
+				  struct odp_flow_key *key, gfp_t gfp)
+{
+	skb = make_writable(skb, gfp);
+	if (skb) {
+		vlan_pull_tag(skb);
+		key->dl_vlan = htons(ODP_VLAN_NONE);
+	}
+	return skb;
+}
+
+static struct sk_buff *set_dl_addr(struct sk_buff *skb,
+				   const struct odp_action_dl_addr *a,
+				   gfp_t gfp)
+{
+	skb = make_writable(skb, gfp);
+	if (skb) {
+		struct ethhdr *eh = eth_hdr(skb);
+		memcpy(a->type == ODPAT_SET_DL_SRC ? eh->h_source : eh->h_dest,
+		       a->dl_addr, ETH_ALEN);
+	}
+	return skb;
+}
+
+/* Updates 'sum', which is a field in 'skb''s data, given that a 4-byte field
+ * covered by the sum has been changed from 'from' to 'to'.  If set,
+ * 'pseudohdr' indicates that the field is in the TCP or UDP pseudo-header.
+ * Based on nf_proto_csum_replace4. */
+static void update_csum(__sum16 *sum, struct sk_buff *skb,
+			__be32 from, __be32 to, int pseudohdr)
+{
+	__be32 diff[] = { ~from, to };
+	if (skb->ip_summed != CHECKSUM_PARTIAL) {
+		*sum = csum_fold(csum_partial((char *)diff, sizeof(diff),
+				~csum_unfold(*sum)));
+		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
+			skb->csum = ~csum_partial((char *)diff, sizeof(diff),
+						~skb->csum);
+	} else if (pseudohdr)
+		*sum = ~csum_fold(csum_partial((char *)diff, sizeof(diff),
+				csum_unfold(*sum)));
+}
+
+static struct sk_buff *set_nw_addr(struct sk_buff *skb,
+				   struct odp_flow_key *key,
+				   const struct odp_action_nw_addr *a,
+				   gfp_t gfp)
+{
+	if (key->dl_type != htons(ETH_P_IP))
+		return skb;
+
+	skb = make_writable(skb, gfp);
+	if (skb) {
+		struct iphdr *nh = ip_hdr(skb);
+		u32 *f = a->type == ODPAT_SET_NW_SRC ? &nh->saddr : &nh->daddr;
+		u32 old = *f;
+		u32 new = a->nw_addr;
+
+		if (key->nw_proto == IPPROTO_TCP) {
+			struct tcphdr *th = tcp_hdr(skb);
+			update_csum(&th->check, skb, old, new, 1);
+		} else if (key->nw_proto == IPPROTO_UDP) {
+			struct udphdr *th = udp_hdr(skb);
+			update_csum(&th->check, skb, old, new, 1);
+		}
+		update_csum(&nh->check, skb, old, new, 0);
+		*f = new;
+	}
+	return skb;
+}
+
+static struct sk_buff *
+set_tp_port(struct sk_buff *skb, struct odp_flow_key *key,
+	    const struct odp_action_tp_port *a,
+	    gfp_t gfp)
+{
+	int check_ofs;
+
+	if (key->dl_type != htons(ETH_P_IP))
+		return skb;
+
+	if (key->nw_proto == IPPROTO_TCP)
+		check_ofs = offsetof(struct tcphdr, check);
+	else if (key->nw_proto == IPPROTO_UDP)
+		check_ofs = offsetof(struct udphdr, check);
+	else
+		return skb;
+
+	skb = make_writable(skb, gfp);
+	if (skb) {
+		struct udphdr *th = udp_hdr(skb);
+		u16 *f = a->type == ODPAT_SET_TP_SRC ? &th->source : &th->dest;
+		u16 old = *f;
+		u16 new = a->tp_port;
+		update_csum((u16*)((u8*)skb->data + check_ofs),
+			    skb, old, new, 1);
+		*f = new;
+	}
+	return skb;
+}
+
+static inline unsigned packet_length(const struct sk_buff *skb)
+{
+	unsigned length = skb->len - ETH_HLEN;
+	if (skb->protocol == htons(ETH_P_8021Q))
+		length -= VLAN_HLEN;
+	return length;
+}
+
+int dp_xmit_skb(struct sk_buff *skb)
+{
+	struct datapath *dp = skb->dev->br_port->dp;
+	int len = skb->len;
+
+	if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) {
+		printk(KERN_WARNING "%s: dropped over-mtu packet: %d > %d\n",
+		       dp_name(dp), packet_length(skb), skb->dev->mtu);
+		kfree_skb(skb);
+		return -E2BIG;
+	}
+
+	dev_queue_xmit(skb);
+
+	return len;
+}
+
+static void
+do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
+{
+	struct net_bridge_port *p;
+	struct net_device *dev;
+
+	if (!skb)
+		goto error;
+
+	p = dp->ports[out_port];
+	if (!p)
+		goto error;
+
+	dev = skb->dev = p->dev;
+	if (is_dp_dev(dev))
+		dp_dev_recv(dev, skb);
+        else
+		dp_xmit_skb(skb);
+	return;
+
+error:
+	kfree_skb(skb);
+}
+
+/* Never consumes 'skb'.  Returns a port that 'skb' should be sent to, -1 if
+ * none.  */
+static int output_group(struct datapath *dp, __u16 group,
+			struct sk_buff *skb, gfp_t gfp)
+{
+	struct dp_port_group *g = rcu_dereference(dp->groups[group]);
+	int prev_port = -1;
+	int i;
+
+	if (!g)
+		return -1;
+	for (i = 0; i < g->n_ports; i++) {
+		struct net_bridge_port *p = dp->ports[g->ports[i]];
+		if (!p || skb->dev == p->dev)
+			continue;
+		if (prev_port != -1) {
+			struct sk_buff *clone = skb_clone(skb, gfp);
+			if (!clone)
+				return -1;
+			do_output(dp, clone, prev_port);
+		}
+		prev_port = p->port_no;
+	}
+	return prev_port;
+}
+
+static int
+output_control(struct datapath *dp, struct sk_buff *skb, u32 arg, gfp_t gfp)
+{
+	skb = skb_clone(skb, gfp);
+	if (!skb)
+		return -ENOMEM;
+	return dp_output_control(dp, skb, _ODPL_ACTION_NR, arg);
+}
+
+/* Execute a list of actions against 'skb'. */
+int execute_actions(struct datapath *dp, struct sk_buff *skb,
+		    struct odp_flow_key *key,
+		    const union odp_action *a, int n_actions,
+		    gfp_t gfp)
+{
+	/* Every output action needs a separate clone of 'skb', but the common
+	 * case is just a single output action, so that doing a clone and
+	 * then freeing the original skbuff is wasteful.  So the following code
+	 * is slightly obscure just to avoid that. */
+	int prev_port = -1;
+	int err = 0;
+	for (; n_actions > 0; a++, n_actions--) {
+		WARN_ON_ONCE(skb_shared(skb));
+		if (prev_port != -1) {
+			do_output(dp, skb_clone(skb, gfp), prev_port);
+			prev_port = -1;
+		}
+
+		switch (a->type) {
+		case ODPAT_OUTPUT:
+			prev_port = a->output.port;
+			break;
+
+		case ODPAT_OUTPUT_GROUP:
+			prev_port = output_group(dp, a->output_group.group,
+						 skb, gfp);
+			break;
+
+		case ODPAT_CONTROLLER:
+			err = output_control(dp, skb, a->controller.arg, gfp);
+			if (err) {
+				kfree_skb(skb);
+				return err;
+			}
+			break;
+
+		case ODPAT_SET_VLAN_VID:
+		case ODPAT_SET_VLAN_PCP:
+			skb = modify_vlan_tci(dp, skb, key, a, n_actions, gfp);
+			if (IS_ERR(skb))
+				return PTR_ERR(skb);
+			break;
+
+		case ODPAT_STRIP_VLAN:
+			skb = strip_vlan(skb, key, gfp);
+			break;
+
+		case ODPAT_SET_DL_SRC:
+		case ODPAT_SET_DL_DST:
+			skb = set_dl_addr(skb, &a->dl_addr, gfp);
+			break;
+
+		case ODPAT_SET_NW_SRC:
+		case ODPAT_SET_NW_DST:
+			skb = set_nw_addr(skb, key, &a->nw_addr, gfp);
+			break;
+
+		case ODPAT_SET_TP_SRC:
+		case ODPAT_SET_TP_DST:
+			skb = set_tp_port(skb, key, &a->tp_port, gfp);
+			break;
+		}
+		if (!skb)
+			return -ENOMEM;
+	}
+	if (prev_port != -1)
+		do_output(dp, skb, prev_port);
+	else
+		kfree_skb(skb);
+	return err;
+}