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/*
* Copyright (c) 2007-2012 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/tcp.h>
#include <linux/udp.h>
#include <linux/in6.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include <net/ip.h>
#include <net/checksum.h>
#include <net/dsfield.h>
#include "datapath.h"
#include "vport.h"
static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
const struct nlattr *attr, int len, bool keep_skb);
static int make_writable(struct sk_buff *skb, int write_len)
{
if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
return 0;
return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
}
/* remove VLAN header from packet and update csum accordingly. */
static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
{
struct vlan_hdr *vhdr;
int err;
err = make_writable(skb, VLAN_ETH_HLEN);
if (unlikely(err))
return err;
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->csum = csum_sub(skb->csum, csum_partial(skb->data
+ ETH_HLEN, VLAN_HLEN, 0));
vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
*current_tci = vhdr->h_vlan_TCI;
memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
__skb_pull(skb, VLAN_HLEN);
vlan_set_encap_proto(skb, vhdr);
skb->mac_header += VLAN_HLEN;
skb_reset_mac_len(skb);
return 0;
}
static int pop_vlan(struct sk_buff *skb)
{
__be16 tci;
int err;
if (likely(vlan_tx_tag_present(skb))) {
skb->vlan_tci = 0;
} else {
if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
skb->len < VLAN_ETH_HLEN))
return 0;
err = __pop_vlan_tci(skb, &tci);
if (err)
return err;
}
/* move next vlan tag to hw accel tag */
if (likely(skb->protocol != htons(ETH_P_8021Q) ||
skb->len < VLAN_ETH_HLEN))
return 0;
err = __pop_vlan_tci(skb, &tci);
if (unlikely(err))
return err;
__vlan_hwaccel_put_tag(skb, ntohs(tci));
return 0;
}
static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vlan)
{
if (unlikely(vlan_tx_tag_present(skb))) {
u16 current_tag;
/* push down current VLAN tag */
current_tag = vlan_tx_tag_get(skb);
if (!__vlan_put_tag(skb, current_tag))
return -ENOMEM;
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->csum = csum_add(skb->csum, csum_partial(skb->data
+ ETH_HLEN, VLAN_HLEN, 0));
}
__vlan_hwaccel_put_tag(skb, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
return 0;
}
static int set_eth_addr(struct sk_buff *skb,
const struct ovs_key_ethernet *eth_key)
{
int err;
err = make_writable(skb, ETH_HLEN);
if (unlikely(err))
return err;
memcpy(eth_hdr(skb)->h_source, eth_key->eth_src, ETH_ALEN);
memcpy(eth_hdr(skb)->h_dest, eth_key->eth_dst, ETH_ALEN);
return 0;
}
static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
__be32 *addr, __be32 new_addr)
{
int transport_len = skb->len - skb_transport_offset(skb);
if (nh->protocol == IPPROTO_TCP) {
if (likely(transport_len >= sizeof(struct tcphdr)))
inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
*addr, new_addr, 1);
} 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, 1);
if (!uh->check)
uh->check = CSUM_MANGLED_0;
}
}
}
csum_replace4(&nh->check, *addr, new_addr);
skb->rxhash = 0;
*addr = new_addr;
}
static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
{
csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
nh->ttl = new_ttl;
}
static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
{
struct iphdr *nh;
int err;
err = make_writable(skb, skb_network_offset(skb) +
sizeof(struct iphdr));
if (unlikely(err))
return err;
nh = ip_hdr(skb);
if (ipv4_key->ipv4_src != nh->saddr)
set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
if (ipv4_key->ipv4_dst != nh->daddr)
set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
if (ipv4_key->ipv4_tos != nh->tos)
ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
if (ipv4_key->ipv4_ttl != nh->ttl)
set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
return 0;
}
/* Must follow make_writable() since that can move the skb data. */
static void set_tp_port(struct sk_buff *skb, __be16 *port,
__be16 new_port, __sum16 *check)
{
inet_proto_csum_replace2(check, skb, *port, new_port, 0);
*port = new_port;
skb->rxhash = 0;
}
static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
{
struct udphdr *uh = udp_hdr(skb);
if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
set_tp_port(skb, port, new_port, &uh->check);
if (!uh->check)
uh->check = CSUM_MANGLED_0;
} else {
*port = new_port;
skb->rxhash = 0;
}
}
static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
{
struct udphdr *uh;
int err;
err = make_writable(skb, skb_transport_offset(skb) +
sizeof(struct udphdr));
if (unlikely(err))
return err;
uh = udp_hdr
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