[mirror_ovs.git] / datapath / actions.c

/*
 * 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;
}
Commit	Line	Data
064af421 BP	1	/*
	2	* Distributed under the terms of the GNU GPL version 2.
	3	* Copyright (c) 2007, 2008, 2009 Nicira Networks.
	4	*/
	5
	6	/* Functions for executing flow actions. */
	7
	8	#include <linux/skbuff.h>
	9	#include <linux/in.h>
	10	#include <linux/ip.h>
	11	#include <linux/tcp.h>
	12	#include <linux/udp.h>
	13	#include <linux/in6.h>
	14	#include <linux/if_vlan.h>
	15	#include <net/ip.h>
	16	#include <net/checksum.h>
	17	#include "datapath.h"
	18	#include "dp_dev.h"
	19	#include "actions.h"
	20	#include "openvswitch/datapath-protocol.h"
	21
	22	struct sk_buff *
	23	make_writable(struct sk_buff *skb, gfp_t gfp)
	24	{
	25	if (skb_shared(skb) \|\| skb_cloned(skb)) {
	26	struct sk_buff *nskb = skb_copy(skb, gfp);
	27	if (nskb) {
	28	kfree_skb(skb);
	29	return nskb;
	30	}
	31	} else {
	32	unsigned int hdr_len = (skb_transport_offset(skb)
	33	+ sizeof(struct tcphdr));
	34	if (pskb_may_pull(skb, min(hdr_len, skb->len)))
	35	return skb;
	36	}
	37	kfree_skb(skb);
	38	return NULL;
	39	}
	40
	41
	42	static struct sk_buff *
	43	vlan_pull_tag(struct sk_buff *skb)
	44	{
	45	struct vlan_ethhdr *vh = vlan_eth_hdr(skb);
	46	struct ethhdr *eh;
	47
	48
	49	/* Verify we were given a vlan packet */
	50	if (vh->h_vlan_proto != htons(ETH_P_8021Q))
	51	return skb;
	52
	53	memmove(skb->data + VLAN_HLEN, skb->data, 2 * VLAN_ETH_ALEN);
	54
	55	eh = (struct ethhdr *)skb_pull(skb, VLAN_HLEN);
	56
	57	skb->protocol = eh->h_proto;
	58	skb->mac_header += VLAN_HLEN;
	59
	60	return skb;
	61	}
	62
	63
	64	static struct sk_buff *
65	modify_vlan_tci(struct datapath dp, struct sk_buff skb,
66	struct odp_flow_key key, const union odp_action a,
67	int n_actions, gfp_t gfp)
68	{
69	u16 tci, mask;
70
71	if (a->type == ODPAT_SET_VLAN_VID) {
72	tci = ntohs(a->vlan_vid.vlan_vid);
73	mask = VLAN_VID_MASK;
74	key->dl_vlan = htons(tci & mask);
75	} else {
76	tci = a->vlan_pcp.vlan_pcp << 13;
77	mask = VLAN_PCP_MASK;
78	}
79
80	skb = make_writable(skb, gfp);
81	if (!skb)
82	return ERR_PTR(-ENOMEM);
83
84	if (skb->protocol == htons(ETH_P_8021Q)) {
85	/* Modify vlan id, but maintain other TCI values */
86	struct vlan_ethhdr *vh = vlan_eth_hdr(skb);
87	vh->h_vlan_TCI = htons((ntohs(vh->h_vlan_TCI) & ~mask) \| tci);
88	} else {
89	/* Add vlan header */
90
91	/* Set up checksumming pointers for checksum-deferred packets
92	* on Xen. Otherwise, dev_queue_xmit() will try to do this
93	* when we send the packet out on the wire, and it will fail at
94	* that point because skb_checksum_setup() will not look inside
95	* an 802.1Q header. */
96	skb_checksum_setup(skb);
97
98	/* GSO is not implemented for packets with an 802.1Q header, so
99	* we have to do segmentation before we add that header.
100	*
101	* GSO does work with hardware-accelerated VLAN tagging, but we
102	* can't use hardware-accelerated VLAN tagging since it
103	* requires the device to have a VLAN group configured (with
104	* e.g. vconfig(8)) and we don't do that.
105	*
106	* Having to do this here may be a performance loss, since we
107	* can't take advantage of TSO hardware support, although it
108	* does not make a measurable network performance difference
109	* for 1G Ethernet. Fixing that would require patching the
110	* kernel (either to add GSO support to the VLAN protocol or to
111	* support hardware-accelerated VLAN tagging without VLAN
112	* groups configured). */
113	if (skb_is_gso(skb)) {
114	struct sk_buff *segs;
115
116	segs = skb_gso_segment(skb, 0);
117	kfree_skb(skb);
118	if (unlikely(IS_ERR(segs)))
119	return ERR_CAST(segs);
120
121	do {
122	struct sk_buff *nskb = segs->next;
123	int err;
124
125	segs->next = NULL;
126
127	segs = __vlan_put_tag(segs, tci);
128	err = -ENOMEM;
129	if (segs) {
130	struct odp_flow_key segkey = *key;
131	err = execute_actions(dp, segs,
132	&segkey, a + 1,
133	n_actions - 1,
134	gfp);
135	}
136
137	if (unlikely(err)) {
138	while ((segs = nskb)) {
139	nskb = segs->next;
140	segs->next = NULL;
141	kfree_skb(segs);
142	}
143	return ERR_PTR(err);
144	}
145
146	segs = nskb;
147	} while (segs->next);
148
149	skb = segs;
150	}
151
152	/* The hardware-accelerated version of vlan_put_tag() works
153	* only for a device that has a VLAN group configured (with
154	* e.g. vconfig(8)), so call the software-only version
155	* __vlan_put_tag() directly instead.
156	*/
157	skb = __vlan_put_tag(skb, tci);
158	if (!skb)
159	return ERR_PTR(-ENOMEM);
160	}
161
162	return skb;
163	}
164
165	static struct sk_buff strip_vlan(struct sk_buff skb,
166	struct odp_flow_key *key, gfp_t gfp)
167	{
168	skb = make_writable(skb, gfp);
169	if (skb) {
170	vlan_pull_tag(skb);
171	key->dl_vlan = htons(ODP_VLAN_NONE);
172	}
173	return skb;
174	}
175
176	static struct sk_buff set_dl_addr(struct sk_buff skb,
177	const struct odp_action_dl_addr *a,
178	gfp_t gfp)
179	{
180	skb = make_writable(skb, gfp);
181	if (skb) {
182	struct ethhdr *eh = eth_hdr(skb);
183	memcpy(a->type == ODPAT_SET_DL_SRC ? eh->h_source : eh->h_dest,
184	a->dl_addr, ETH_ALEN);
185	}
186	return skb;
187	}
188
189	/* Updates 'sum', which is a field in 'skb''s data, given that a 4-byte field
190	* covered by the sum has been changed from 'from' to 'to'. If set,
191	* 'pseudohdr' indicates that the field is in the TCP or UDP pseudo-header.
192	* Based on nf_proto_csum_replace4. */
193	static void update_csum(__sum16 sum, struct sk_buff skb,
194	__be32 from, __be32 to, int pseudohdr)
195	{
196	__be32 diff[] = { ~from, to };
197	if (skb->ip_summed != CHECKSUM_PARTIAL) {
198	sum = csum_fold(csum_partial((char )diff, sizeof(diff),
199	~csum_unfold(*sum)));
200	if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
201	skb->csum = ~csum_partial((char *)diff, sizeof(diff),
202	~skb->csum);
203	} else if (pseudohdr)
204	sum = ~csum_fold(csum_partial((char )diff, sizeof(diff),
205	csum_unfold(*sum)));
206	}
207
208	static struct sk_buff set_nw_addr(struct sk_buff skb,
209	struct odp_flow_key *key,
210	const struct odp_action_nw_addr *a,
211	gfp_t gfp)
212	{
213	if (key->dl_type != htons(ETH_P_IP))
214	return skb;
215
216	skb = make_writable(skb, gfp);
217	if (skb) {
218	struct iphdr *nh = ip_hdr(skb);
219	u32 *f = a->type == ODPAT_SET_NW_SRC ? &nh->saddr : &nh->daddr;
220	u32 old = *f;
221	u32 new = a->nw_addr;
222
223	if (key->nw_proto == IPPROTO_TCP) {
224	struct tcphdr *th = tcp_hdr(skb);
225	update_csum(&th->check, skb, old, new, 1);
226	} else if (key->nw_proto == IPPROTO_UDP) {
227	struct udphdr *th = udp_hdr(skb);
228	update_csum(&th->check, skb, old, new, 1);
229	}
230	update_csum(&nh->check, skb, old, new, 0);
231	*f = new;
232	}
233	return skb;
234	}
235
236	static struct sk_buff *
237	set_tp_port(struct sk_buff skb, struct odp_flow_key key,
238	const struct odp_action_tp_port *a,
239	gfp_t gfp)
240	{
241	int check_ofs;
242
243	if (key->dl_type != htons(ETH_P_IP))
244	return skb;
245
246	if (key->nw_proto == IPPROTO_TCP)
247	check_ofs = offsetof(struct tcphdr, check);
248	else if (key->nw_proto == IPPROTO_UDP)
249	check_ofs = offsetof(struct udphdr, check);
250	else
251	return skb;
252
253	skb = make_writable(skb, gfp);
254	if (skb) {
255	struct udphdr *th = udp_hdr(skb);
256	u16 *f = a->type == ODPAT_SET_TP_SRC ? &th->source : &th->dest;
257	u16 old = *f;
258	u16 new = a->tp_port;
259	update_csum((u16)((u8)skb->data + check_ofs),
260	skb, old, new, 1);
261	*f = new;
262	}
263	return skb;
264	}
265
266	static inline unsigned packet_length(const struct sk_buff *skb)
267	{
268	unsigned length = skb->len - ETH_HLEN;
269	if (skb->protocol == htons(ETH_P_8021Q))
270	length -= VLAN_HLEN;
271	return length;
272	}
273
274	int dp_xmit_skb(struct sk_buff *skb)
275	{
276	struct datapath *dp = skb->dev->br_port->dp;
277	int len = skb->len;
278
279	if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) {
280	printk(KERN_WARNING "%s: dropped over-mtu packet: %d > %d\n",
281	dp_name(dp), packet_length(skb), skb->dev->mtu);
282	kfree_skb(skb);
283	return -E2BIG;
284	}
285
286	dev_queue_xmit(skb);
287
288	return len;
289	}
290
291	static void
292	do_output(struct datapath dp, struct sk_buff skb, int out_port)
293	{
294	struct net_bridge_port *p;
295	struct net_device *dev;
296
297	if (!skb)
298	goto error;
299
300	p = dp->ports[out_port];
301	if (!p)
302	goto error;
303
304	dev = skb->dev = p->dev;
305	if (is_dp_dev(dev))
306	dp_dev_recv(dev, skb);
307	else
308	dp_xmit_skb(skb);
309	return;
310
311	error:
312	kfree_skb(skb);
313	}
314
315	/* Never consumes 'skb'. Returns a port that 'skb' should be sent to, -1 if
316	* none. */
317	static int output_group(struct datapath *dp, __u16 group,
318	struct sk_buff *skb, gfp_t gfp)
319	{
320	struct dp_port_group *g = rcu_dereference(dp->groups[group]);
321	int prev_port = -1;
322	int i;
323
324	if (!g)
325	return -1;
326	for (i = 0; i < g->n_ports; i++) {
327	struct net_bridge_port *p = dp->ports[g->ports[i]];
328	if (!p \|\| skb->dev == p->dev)
329	continue;
330	if (prev_port != -1) {
331	struct sk_buff *clone = skb_clone(skb, gfp);
332	if (!clone)
333	return -1;
334	do_output(dp, clone, prev_port);
335	}
336	prev_port = p->port_no;
337	}
338	return prev_port;
339	}
340
341	static int
342	output_control(struct datapath dp, struct sk_buff skb, u32 arg, gfp_t gfp)
343	{
344	skb = skb_clone(skb, gfp);
345	if (!skb)
346	return -ENOMEM;
347	return dp_output_control(dp, skb, _ODPL_ACTION_NR, arg);
348	}
349
350	/* Execute a list of actions against 'skb'. */
351	int execute_actions(struct datapath dp, struct sk_buff skb,
352	struct odp_flow_key *key,
353	const union odp_action *a, int n_actions,
354	gfp_t gfp)
355	{
356	/* Every output action needs a separate clone of 'skb', but the common
357	* case is just a single output action, so that doing a clone and
358	* then freeing the original skbuff is wasteful. So the following code
359	* is slightly obscure just to avoid that. */
360	int prev_port = -1;
361	int err = 0;
362	for (; n_actions > 0; a++, n_actions--) {
363	WARN_ON_ONCE(skb_shared(skb));
364	if (prev_port != -1) {
365	do_output(dp, skb_clone(skb, gfp), prev_port);
366	prev_port = -1;
367	}
368
369	switch (a->type) {
370	case ODPAT_OUTPUT:
371	prev_port = a->output.port;
372	break;
373
374	case ODPAT_OUTPUT_GROUP:
375	prev_port = output_group(dp, a->output_group.group,
376	skb, gfp);
377	break;
378
379	case ODPAT_CONTROLLER:
380	err = output_control(dp, skb, a->controller.arg, gfp);
381	if (err) {
382	kfree_skb(skb);
383	return err;
384	}
385	break;
386
387	case ODPAT_SET_VLAN_VID:
388	case ODPAT_SET_VLAN_PCP:
389	skb = modify_vlan_tci(dp, skb, key, a, n_actions, gfp);
390	if (IS_ERR(skb))
391	return PTR_ERR(skb);
392	break;
393
394	case ODPAT_STRIP_VLAN:
395	skb = strip_vlan(skb, key, gfp);
396	break;
397
398	case ODPAT_SET_DL_SRC:
399	case ODPAT_SET_DL_DST:
400	skb = set_dl_addr(skb, &a->dl_addr, gfp);
401	break;
402
403	case ODPAT_SET_NW_SRC:
404	case ODPAT_SET_NW_DST:
405	skb = set_nw_addr(skb, key, &a->nw_addr, gfp);
406	break;
407
408	case ODPAT_SET_TP_SRC:
409	case ODPAT_SET_TP_DST:
410	skb = set_tp_port(skb, key, &a->tp_port, gfp);
411	break;
412	}
413	if (!skb)
414	return -ENOMEM;
415	}
416	if (prev_port != -1)
417	do_output(dp, skb, prev_port);
418	else
419	kfree_skb(skb);
420	return err;
421	}