Release 4.11 net/openvswitch/actions.c

/*
 * Copyright (c) 2007-2014 Nicira, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/openvswitch.h>
#include <linux/netfilter_ipv6.h>
#include <linux/sctp.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/in6.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>

#include <net/dst.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ip6_fib.h>
#include <net/checksum.h>
#include <net/dsfield.h>
#include <net/mpls.h>
#include <net/sctp/checksum.h>

#include "datapath.h"
#include "flow.h"
#include "conntrack.h"
#include "vport.h"

static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
			      struct sw_flow_key *key,
			      const struct nlattr *attr, int len);


struct deferred_action {
	
struct sk_buff *skb;
	
const struct nlattr *actions;

	/* Store pkt_key clone when creating deferred action. */
	
struct sw_flow_key pkt_key;
};


#define MAX_L2_LEN	(VLAN_ETH_HLEN + 3 * MPLS_HLEN)

struct ovs_frag_data {
	
unsigned long dst;
	
struct vport *vport;
	
struct ovs_skb_cb cb;
	
__be16 inner_protocol;
	
u16 network_offset;	/* valid only for MPLS */
	
u16 vlan_tci;
	
__be16 vlan_proto;
	
unsigned int l2_len;
	
u8 mac_proto;
	
u8 l2_data[MAX_L2_LEN];
};

static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage);


#define DEFERRED_ACTION_FIFO_SIZE 10

#define OVS_RECURSION_LIMIT 5

#define OVS_DEFERRED_ACTION_THRESHOLD (OVS_RECURSION_LIMIT - 2)

struct action_fifo {
	
int head;
	
int tail;
	/* Deferred action fifo queue storage. */
	
struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE];
};


struct recirc_keys {
	
struct sw_flow_key key[OVS_DEFERRED_ACTION_THRESHOLD];
};


static struct action_fifo __percpu *action_fifos;

static struct recirc_keys __percpu *recirc_keys;
static DEFINE_PER_CPU(int, exec_actions_level);



static void action_fifo_init(struct action_fifo *fifo)
{
	fifo->head = 0;
	fifo->tail = 0;
}

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static bool action_fifo_is_empty(const struct action_fifo *fifo)
{
	return (fifo->head == fifo->tail);
}

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static struct deferred_action *action_fifo_get(struct action_fifo *fifo)
{
	if (action_fifo_is_empty(fifo))
		return NULL;

	return &fifo->fifo[fifo->tail++];
}

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static struct deferred_action *action_fifo_put(struct action_fifo *fifo)
{
	if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1)
		return NULL;

	return &fifo->fifo[fifo->head++];
}

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/* Return true if fifo is not full */


static struct deferred_action *add_deferred_actions(struct sk_buff *skb,
						    const struct sw_flow_key *key,
						    const struct nlattr *attr)
{
	struct action_fifo *fifo;
	struct deferred_action *da;

	fifo = this_cpu_ptr(action_fifos);
	da = action_fifo_put(fifo);
	if (da) {
		da->skb = skb;
		da->actions = attr;
		da->pkt_key = *key;
	}

	return da;
}

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static void invalidate_flow_key(struct sw_flow_key *key)
{
	key->mac_proto |= SW_FLOW_KEY_INVALID;
}

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static bool is_flow_key_valid(const struct sw_flow_key *key)
{
	return !(key->mac_proto & SW_FLOW_KEY_INVALID);
}

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static void update_ethertype(struct sk_buff *skb, struct ethhdr *hdr,
			     __be16 ethertype)
{
	if (skb->ip_summed == CHECKSUM_COMPLETE) {
		__be16 diff[] = { ~(hdr->h_proto), ethertype };

		skb->csum = ~csum_partial((char *)diff, sizeof(diff),
					~skb->csum);
	}

	hdr->h_proto = ethertype;
}

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static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key,
		     const struct ovs_action_push_mpls *mpls)
{
	struct mpls_shim_hdr *new_mpls_lse;

	/* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */
	if (skb->encapsulation)
		return -ENOTSUPP;

	if (skb_cow_head(skb, MPLS_HLEN) < 0)
		return -ENOMEM;

	if (!skb->inner_protocol) {
		skb_set_inner_network_header(skb, skb->mac_len);
		skb_set_inner_protocol(skb, skb->protocol);
	}

	skb_push(skb, MPLS_HLEN);
	memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb),
		skb->mac_len);
	skb_reset_mac_header(skb);
	skb_set_network_header(skb, skb->mac_len);

	new_mpls_lse = mpls_hdr(skb);
	new_mpls_lse->label_stack_entry = mpls->mpls_lse;

	skb_postpush_rcsum(skb, new_mpls_lse, MPLS_HLEN);

	if (ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET)
		update_ethertype(skb, eth_hdr(skb), mpls->mpls_ethertype);
	skb->protocol = mpls->mpls_ethertype;

	invalidate_flow_key(key);
	return 0;
}

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David Ahern
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Jiri Benc
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Daniel Borkmann
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static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key,
		    const __be16 ethertype)
{
	int err;

	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
	if (unlikely(err))
		return err;

	skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN);

	memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb),
		skb->mac_len);

	__skb_pull(skb, MPLS_HLEN);
	skb_reset_mac_header(skb);
	skb_set_network_header(skb, skb->mac_len);

	if (ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET) {
		struct ethhdr *hdr;

		/* mpls_hdr() is used to locate the ethertype field correctly in the
                 * presence of VLAN tags.
                 */
		hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN);
		update_ethertype(skb, hdr, ethertype);
	}
	if (eth_p_mpls(skb->protocol))
		skb->protocol = ethertype;

	invalidate_flow_key(key);
	return 0;
}

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Jiri Benc
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Pravin B Shelar
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David Ahern
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Jiri Pirko
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static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key,
		    const __be32 *mpls_lse, const __be32 *mask)
{
	struct mpls_shim_hdr *stack;
	__be32 lse;
	int err;

	err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN);
	if (unlikely(err))
		return err;

	stack = mpls_hdr(skb);
	lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask);
	if (skb->ip_summed == CHECKSUM_COMPLETE) {
		__be32 diff[] = { ~(stack->label_stack_entry), lse };

		skb->csum = ~csum_partial((char *)diff, sizeof(diff),
					  ~skb->csum);
	}

	stack->label_stack_entry = lse;
	flow_key->mpls.top_lse = lse;
	return 0;
}

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Jarno Rajahalme
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static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key)
{
	int err;

	err = skb_vlan_pop(skb);
	if (skb_vlan_tag_present(skb)) {
		invalidate_flow_key(key);
	} else {
		key->eth.vlan.tci = 0;
		key->eth.vlan.tpid = 0;
	}
	return err;
}

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static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key,
		     const struct ovs_action_push_vlan *vlan)
{
	if (skb_vlan_tag_present(skb)) {
		invalidate_flow_key(key);
	} else {
		key->eth.vlan.tci = vlan->vlan_tci;
		key->eth.vlan.tpid = vlan->vlan_tpid;
	}
	return skb_vlan_push(skb, vlan->vlan_tpid,
			     ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
}

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/* 'src' is already properly masked. */


static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_)
{
	u16 *dst = (u16 *)dst_;
	const u16 *src = (const u16 *)src_;
	const u16 *mask = (const u16 *)mask_;

	OVS_SET_MASKED(dst[0], src[0], mask[0]);
	OVS_SET_MASKED(dst[1], src[1], mask[1]);
	OVS_SET_MASKED(dst[2], src[2], mask[2]);
}

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static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key,
			const struct ovs_key_ethernet *key,
			const struct ovs_key_ethernet *mask)
{
	int err;

	err = skb_ensure_writable(skb, ETH_HLEN);
	if (unlikely(err))
		return err;

	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);

	ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src,
			       mask->eth_src);
	ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst,
			       mask->eth_dst);

	skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);

	ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source);
	ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest);
	return 0;
}

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Pravin B Shelar
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Jarno Rajahalme
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/* pop_eth does not support VLAN packets as this action is never called
 * for them.
 */


static int pop_eth(struct sk_buff *skb, struct sw_flow_key *key)
{
	skb_pull_rcsum(skb, ETH_HLEN);
	skb_reset_mac_header(skb);
	skb_reset_mac_len(skb);

	/* safe right before invalidate_flow_key */
	key->mac_proto = MAC_PROTO_NONE;
	invalidate_flow_key(key);
	return 0;
}

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static int push_eth(struct sk_buff *skb, struct sw_flow_key *key,
		    const struct ovs_action_push_eth *ethh)
{
	struct ethhdr *hdr;

	/* Add the new Ethernet header */
	if (skb_cow_head(skb, ETH_HLEN) < 0)
		return -ENOMEM;

	skb_push(skb, ETH_HLEN);
	skb_reset_mac_header(skb);
	skb_reset_mac_len(skb);

	hdr = eth_hdr(skb);
	ether_addr_copy(hdr->h_source, ethh->addresses.eth_src);
	ether_addr_copy(hdr->h_dest, ethh->addresses.eth_dst);
	hdr->h_proto = skb->protocol;

	skb_postpush_rcsum(skb, hdr, ETH_HLEN);

	/* safe right before invalidate_flow_key */
	key->mac_proto = MAC_PROTO_ETHERNET;
	invalidate_flow_key(key);
	return 0;
}

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static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,
				  __be32 addr, __be32 new_addr)
{
	int transport_len = skb->len - skb_transport_offset(skb);

	if (nh->frag_off & htons(IP_OFFSET))
		return;

	if (nh->protocol == IPPROTO_TCP) {
		if (likely(transport_len >= sizeof(struct tcphdr)))
			inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
						 addr, new_addr, true);
	} else if (nh->protocol == IPPROTO_UDP) {
		if (likely(transport_len >= sizeof(struct udphdr))) {
			struct udphdr *uh = udp_hdr(skb);

			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
				inet_proto_csum_replace4(&uh->check, skb,
							 addr, new_addr, true);
				if (!uh->check)
					uh->check = CSUM_MANGLED_0;
			}
		}
	}
}

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static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
			__be32 *addr, __be32 new_addr)
{
	update_ip_l4_checksum(skb, nh, *addr, new_addr);
	csum_replace4(&nh->check, *addr, new_addr);
	skb_clear_hash(skb);
	*addr = new_addr;
}

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Glenn Griffin
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Jesse Gross
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static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
				 __be32 addr[4], const __be32 new_addr[4])
{
	int transport_len = skb->len - skb_transport_offset(skb);

	if (l4_proto == NEXTHDR_TCP) {
		if (likely(transport_len >= sizeof(struct tcphdr)))
			inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
						  addr, new_addr, true);
	} else if (l4_proto == NEXTHDR_UDP) {
		if (likely(transport_len >= sizeof(struct udphdr))) {
			struct udphdr *uh = udp_hdr(skb);

			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
				inet_proto_csum_replace16(&uh->check, skb,
							  addr, new_addr, true);
				if (!uh->check)
					uh->check = CSUM_MANGLED_0;
			}
		}
	} else if (l4_proto == NEXTHDR_ICMP) {
		if (likely(transport_len >= sizeof(struct icmp6hdr)))
			inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum,
						  skb, addr, new_addr, true);
	}
}

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1
33.33%
Jesse Gross
42
21.32%
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Tom Herbert
3
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static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4],
			   const __be32 mask[4], __be32 masked[4])
{
	masked[0] = OVS_MASKED(old[0], addr[0], mask[0]);
	masked[1] = OVS_MASKED(old[1], addr[1], mask[1]);
	masked[2] = OVS_MASKED(old[2], addr[2], mask[2]);
	masked[3] = OVS_MASKED(old[3], addr[3], mask[3]);
}

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Ansis Atteka
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27.20%
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Joe Stringer
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3.20%
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Tom Herbert
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static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
			  __be32 addr[4], const __be32 new_addr[4],
			  bool recalculate_csum)
{
	if (recalculate_csum)
		update_ipv6_checksum(skb, l4_proto, addr, new_addr);

	skb_clear_hash(skb);
	memcpy(addr, new_addr, sizeof(__be32[4]));
}

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static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask)
{
	/* Bits 21-24 are always unmasked, so this retains their values. */
	OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16));
	OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8));
	OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask);
}

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49
52.13%
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33.33%
Ansis Atteka
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44.68%
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Joe Stringer
3
3.19%
1
33.33%
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static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl,
		       u8 mask)
{
	new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask);

	csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
	nh->ttl = new_ttl;
}

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33.33%
Jarno Rajahalme
15
23.08%
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Joe Stringer
1
1.54%
1
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65
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static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key,
		    const struct ovs_key_ipv4 *key,
		    const struct ovs_key_ipv4 *mask)
{
	struct iphdr *nh;
	__be32 new_addr;
	int err;

	err = skb_ensure_writable(skb, skb_network_offset(skb) +
				  sizeof(struct iphdr));
	if (unlikely(err))
		return err;

	nh = ip_hdr(skb);

	/* Setting an IP addresses is typically only a side effect of
         * matching on them in the current userspace implementation, so it
         * makes sense to check if the value actually changed.
         */
	if (mask->ipv4_src) {
		new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src);

		if (unlikely(new_addr != nh->saddr)) {
			set_ip_addr(skb, nh, &nh->saddr, new_addr);
			flow_key->ipv4.addr.src = new_addr;
		}
	}
	if (mask->ipv4_dst) {
		new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst);

		if (unlikely(new_addr != nh->daddr)) {
			set_ip_addr(skb, nh, &nh->daddr, new_addr);
			flow_key->ipv4.addr.dst = new_addr;
		}
	}
	if (mask->ipv4_tos) {
		ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos);
		flow_key->ip.tos = nh->tos;
	}
	if (mask->ipv4_ttl) {
		set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl);
		flow_key->ip.ttl = nh->ttl;
	}

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jesse Gross
134
50.19%
1
20.00%
Jarno Rajahalme
85
31.84%
1
20.00%
Pravin B Shelar
45
16.85%
1
20.00%
Joe Stringer
2
0.75%
1
20.00%
Jiri Pirko
1
0.37%
1
20.00%
Total
267
100.00%
5
100.00%



static bool is_ipv6_mask_nonzero(const __be32 addr[4])
{
	return !!(addr[0] | addr[1] | addr[2] | addr[3]);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jarno Rajahalme
38
100.00%
1
100.00%
Total
38
100.00%
1
100.00%



static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key,
		    const struct ovs_key_ipv6 *key,
		    const struct ovs_key_ipv6 *mask)
{
	struct ipv6hdr *nh;
	int err;

	err = skb_ensure_writable(skb, skb_network_offset(skb) +
				  sizeof(struct ipv6hdr));
	if (unlikely(err))
		return err;

	nh = ipv6_hdr(skb);

	/* Setting an IP addresses is typically only a side effect of
         * matching on them in the current userspace implementation, so it
         * makes sense to check if the value actually changed.
         */
	if (is_ipv6_mask_nonzero(mask->ipv6_src)) {
		__be32 *saddr = (__be32 *)&nh->saddr;
		__be32 masked[4];

		mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked);

		if (unlikely(memcmp(saddr, masked, sizeof(masked)))) {
			set_ipv6_addr(skb, flow_key->ip.proto, saddr, masked,
				      true);
			memcpy(&flow_key->ipv6.addr.src, masked,
			       sizeof(flow_key->ipv6.addr.src));
		}
	}
	if (is_ipv6_mask_nonzero(mask->ipv6_dst)) {
		unsigned int offset = 0;
		int flags = IP6_FH_F_SKIP_RH;
		bool recalc_csum = true;
		__be32 *daddr = (__be32 *)&nh->daddr;
		__be32 masked[4];

		mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked);

		if (unlikely(memcmp(daddr, masked, sizeof(masked)))) {
			if (ipv6_ext_hdr(nh->nexthdr))
				recalc_csum = (ipv6_find_hdr(skb, &offset,
							     NEXTHDR_ROUTING,
							     NULL, &flags)
					       != NEXTHDR_ROUTING);

			set_ipv6_addr(skb, flow_key->ip.proto, daddr, masked,
				      recalc_csum);
			memcpy(&flow_key->ipv6</