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tunnel.c
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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/if_arp.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <linux/if_vlan.h>
#include <linux/igmp.h>
#include <linux/in.h>
#include <linux/in_route.h>
#include <linux/inetdevice.h>
#include <linux/jhash.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/version.h>
#include <linux/workqueue.h>
#include <linux/rculist.h>
#include <net/dsfield.h>
#include <net/dst.h>
#include <net/icmp.h>
#include <net/inet_ecn.h>
#include <net/ip.h>
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
#include <net/ipv6.h>
#endif
#include <net/route.h>
#include <net/xfrm.h>
#include "checksum.h"
#include "datapath.h"
#include "tunnel.h"
#include "vlan.h"
#include "vport.h"
#include "vport-internal_dev.h"
#define PORT_TABLE_SIZE 1024
static struct hlist_head *port_table __read_mostly;
/*
* These are just used as an optimization: they don't require any kind of
* synchronization because we could have just as easily read the value before
* the port change happened.
*/
static unsigned int key_local_remote_ports __read_mostly;
static unsigned int key_remote_ports __read_mostly;
static unsigned int key_multicast_ports __read_mostly;
static unsigned int local_remote_ports __read_mostly;
static unsigned int remote_ports __read_mostly;
static unsigned int null_ports __read_mostly;
static unsigned int multicast_ports __read_mostly;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
#define rt_dst(rt) (rt->dst)
#else
#define rt_dst(rt) (rt->u.dst)
#endif
static struct vport *tnl_vport_to_vport(const struct tnl_vport *tnl_vport)
{
return vport_from_priv(tnl_vport);
}
static void free_config_rcu(struct rcu_head *rcu)
{
struct tnl_mutable_config *c = container_of(rcu, struct tnl_mutable_config, rcu);
kfree(c);
}
/* Frees the portion of 'mutable' that requires RTNL and thus can't happen
* within an RCU callback. Fortunately this part doesn't require waiting for
* an RCU grace period.
*/
static void free_mutable_rtnl(struct tnl_mutable_config *mutable)
{
ASSERT_RTNL();
if (ipv4_is_multicast(mutable->key.daddr) && mutable->mlink) {
struct in_device *in_dev;
in_dev = inetdev_by_index(port_key_get_net(&mutable->key), mutable->mlink);
if (in_dev)
ip_mc_dec_group(in_dev, mutable->key.daddr);
}
}
static void assign_config_rcu(struct vport *vport,
struct tnl_mutable_config *new_config)
{
struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
struct tnl_mutable_config *old_config;
old_config = rtnl_dereference(tnl_vport->mutable);
rcu_assign_pointer(tnl_vport->mutable, new_config);
free_mutable_rtnl(old_config);
call_rcu(&old_config->rcu, free_config_rcu);
}
static unsigned int *find_port_pool(const struct tnl_mutable_config *mutable)
{
bool is_multicast = ipv4_is_multicast(mutable->key.daddr);
if (mutable->flags & TNL_F_IN_KEY_MATCH) {
if (mutable->key.saddr)
return &local_remote_ports;
else if (is_multicast)
return &multicast_ports;
else
return &remote_ports;
} else {
if (mutable->key.saddr)
return &key_local_remote_ports;
else if (is_multicast)
return &key_multicast_ports;
else if (mutable->key.daddr)
return &key_remote_ports;
else
return &null_ports;
}
}
static u32 port_hash(const struct port_lookup_key *key)
{
return jhash2((u32 *)key, (PORT_KEY_LEN / sizeof(u32)), 0);
}
static struct hlist_head *find_bucket(u32 hash)
{
return &port_table[(hash & (PORT_TABLE_SIZE - 1))];
}
static void port_table_add_port(struct vport *vport)
{
struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
const struct tnl_mutable_config *mutable;
u32 hash;
mutable = rtnl_dereference(tnl_vport->mutable);
hash = port_hash(&mutable->key);
hlist_add_head_rcu(&tnl_vport->hash_node, find_bucket(hash));
(*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
}
static void port_table_move_port(struct vport *vport,
struct tnl_mutable_config *new_mutable)
{
struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
u32 hash;
hash = port_hash(&new_mutable->key);
hlist_del_init_rcu(&tnl_vport->hash_node);
hlist_add_head_rcu(&tnl_vport->hash_node, find_bucket(hash));
(*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
assign_config_rcu(vport, new_mutable);
(*find_port_pool(rtnl_dereference(tnl_vport->mutable)))++;
}
static void port_table_remove_port(struct vport *vport)
{
struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
hlist_del_init_rcu(&tnl_vport->hash_node);
(*find_port_pool(rtnl_dereference(tnl_vport->mutable)))--;
}
static struct vport *port_table_lookup(struct port_lookup_key *key,
const struct tnl_mutable_config **pmutable)
{
struct hlist_node *n;
struct hlist_head *bucket;
u32 hash = port_hash(key);
struct tnl_vport *tnl_vport;
bucket = find_bucket(hash);
hlist_for_each_entry_rcu(tnl_vport, n, bucket, hash_node) {
struct tnl_mutable_config *mutable;
mutable = rcu_dereference_rtnl(tnl_vport->mutable);
if (!memcmp(&mutable->key, key, PORT_KEY_LEN)) {
*pmutable = mutable;
return tnl_vport_to_vport(tnl_vport);
}
}
return NULL;
}
struct vport *ovs_tnl_find_port(struct net *net, __be32 saddr, __be32 daddr,
__be64 key, int tunnel_type,
const struct tnl_mutable_config **mutable)
{
struct port_lookup_key lookup;
struct vport *vport;
bool is_multicast = ipv4_is_multicast(saddr);
port_key_set_net(&lookup, net);
lookup.saddr = saddr;
lookup.daddr = daddr;
/* First try for exact match on in_key. */
lookup.in_key = key;
lookup.tunnel_type = tunnel_type | TNL_T_KEY_EXACT;
if (!is_multicast && key_local_remote_ports) {
vport = port_table_lookup(&lookup, mutable);
if (vport)
return vport;
}
if (key_remote_ports) {
lookup.saddr = 0;
vport = port_table_lookup(&lookup, mutable);
if (vport)
return vport;
lookup.saddr = saddr;
}
/* Then try matches that wildcard in_key. */
lookup.in_key = 0;
lookup.tunnel_type = tunnel_type | TNL_T_KEY_MATCH;
if (!is_multicast && local_remote_ports) {
vport = port_table_lookup(&lookup, mutable);
if (vport)
return vport;
}
if (remote_ports) {
lookup.saddr = 0;
vport = port_table_lookup(&lookup, mutable);
if (vport)
return vport;
}
if (is_multicast) {
lookup.saddr = 0;
lookup.daddr = saddr;
if (key_multicast_ports) {
lookup.tunnel_type = tunnel_type | TNL_T_KEY_EXACT;
lookup.in_key = key;
vport = port_table_lookup(&lookup, mutable);
if (vport)
return vport;
}
if (multicast_ports) {
lookup.tunnel_type = tunnel_type | TNL_T_KEY_MATCH;
lookup.in_key = 0;
vport = port_table_lookup(&lookup, mutable);
if (vport)
return vport;
}
}
if (null_ports) {
lookup.daddr = 0;
lookup.saddr = 0;
lookup.in_key = 0;
lookup.tunnel_type = tunnel_type;
vport = port_table_lookup(&lookup, mutable);
if (vport)
return vport;
}
return NULL;
}
static void ecn_decapsulate(struct sk_buff *skb)
{
if (unlikely(INET_ECN_is_ce(OVS_CB(skb)->tun_key->ipv4_tos))) {
__be16 protocol = skb->protocol;
skb_set_network_header(skb, ETH_HLEN);
if (protocol == htons(ETH_P_8021Q)) {
if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
return;
protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
skb_set_network_header(skb, VLAN_ETH_HLEN);
}
if (protocol == htons(ETH_P_IP)) {
if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
+ sizeof(struct iphdr))))
return;
IP_ECN_set_ce(ip_hdr(skb));
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
else if (protocol == htons(ETH_P_IPV6)) {
if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
+ sizeof(struct ipv6hdr))))
return;
IP6_ECN_set_ce(ipv6_hdr(skb));
}
#endif
}
}
/**
* ovs_tnl_rcv - ingress point for generic tunnel code
*
* @vport: port this packet was received on
* @skb: received packet
* @tos: ToS from encapsulating IP packet, used to copy ECN bits
*
* Must be called with rcu_read_lock.
*
* Packets received by this function are in the following state:
* - skb->data points to the inner Ethernet header.
* - The inner Ethernet header is in the linear data area.
* - skb->csum does not include the inner Ethernet header.
* - The layer pointers are undefined.
*/
void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb)
{
struct ethhdr *eh;
skb_reset_mac_header(skb);
eh = eth_hdr(skb);
if (likely(ntohs(eh->h_proto) >= 1536))
skb->protocol = eh->h_proto;
else
skb->protocol = htons(ETH_P_802_2);
skb_dst_drop(skb);
nf_reset(skb);
skb_clear_rxhash(skb);
secpath_reset(skb);
ecn_decapsulate(skb);
vlan_set_tci(skb, 0);
if (unlikely(compute_ip_summed(skb, false))) {
kfree_skb(skb);
return;
}
ovs_vport_receive(vport, skb);
}
static bool check_ipv4_address(__be32 addr)
{
if (ipv4_is_multicast(addr) || ipv4_is_lbcast(addr)
|| ipv4_is_loopback(addr) || ipv4_is_zeronet(addr))
return false;
return true;
}
static bool ipv4_should_icmp(struct sk_buff *skb)
{
struct iphdr *old_iph = ip_hdr(skb);
/* Don't respond to L2 broadcast. */
if (is_multicast_ether_addr(eth_hdr(skb)->h_dest))
return false;
/* Don't respond to L3 broadcast or invalid addresses. */
if (!check_ipv4_address(old_iph->daddr) ||
!check_ipv4_address(old_iph->saddr))
return false;
/* Only respond to the first fragment. */
if (old_iph->frag_off & htons(IP_OFFSET))
return false;
/* Don't respond to ICMP error messages. */
if (old_iph->protocol == IPPROTO_ICMP) {
u8 icmp_type, *icmp_typep;
icmp_typep = skb_header_pointer(skb, (u8 *)old_iph +
(old_iph->ihl << 2) +
offsetof(struct icmphdr, type) -
skb->data, sizeof(icmp_type),
&icmp_type);
if (!icmp_typep)
return false;
if (*icmp_typep > NR_ICMP_TYPES
|| (*icmp_typep <= ICMP_PARAMETERPROB
&& *icmp_typep != ICMP_ECHOREPLY
&& *icmp_typep != ICMP_ECHO))
return false;
}
return true;
}
static void ipv4_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
unsigned int mtu, unsigned int payload_length)
{
struct iphdr *iph, *old_iph = ip_hdr(skb);
struct icmphdr *icmph;
u8 *payload;
iph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
icmph = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
payload = skb_put(nskb, payload_length);
/* IP */
iph->version = 4;
iph->ihl = sizeof(struct iphdr) >> 2;
iph->tos = (old_iph->tos & IPTOS_TOS_MASK) |
IPTOS_PREC_INTERNETCONTROL;
iph->tot_len = htons(sizeof(struct iphdr)
+ sizeof(struct icmphdr)
+ payload_length);
get_random_bytes(&iph->id, sizeof(iph->id));
iph->frag_off = 0;
iph->ttl = IPDEFTTL;
iph->protocol = IPPROTO_ICMP;
iph->daddr = old_iph->saddr;
iph->saddr = old_iph->daddr;
ip_send_check(iph);
/* ICMP */
icmph->type = ICMP_DEST_UNREACH;
icmph->code = ICMP_FRAG_NEEDED;
icmph->un.gateway = htonl(mtu);
icmph->checksum = 0;
nskb->csum = csum_partial((u8 *)icmph, sizeof(struct icmphdr), 0);
nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_iph - skb->data,
payload, payload_length,
nskb->csum);
icmph->checksum = csum_fold(nskb->csum);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static bool ipv6_should_icmp(struct sk_buff *skb)
{
struct ipv6hdr *old_ipv6h = ipv6_hdr(skb);
int addr_type;
int payload_off = (u8 *)(old_ipv6h + 1) - skb->data;
u8 nexthdr = ipv6_hdr(skb)->nexthdr;
__be16 frag_off;
/* Check source address is valid. */
addr_type = ipv6_addr_type(&old_ipv6h->saddr);
if (addr_type & IPV6_ADDR_MULTICAST || addr_type == IPV6_ADDR_ANY)
return false;
/* Don't reply to unspecified addresses. */
if (ipv6_addr_type(&old_ipv6h->daddr) == IPV6_ADDR_ANY)
return false;
/* Don't respond to ICMP error messages. */
payload_off = ipv6_skip_exthdr(skb, payload_off, &nexthdr, &frag_off);
if (payload_off < 0)
return false;
if (nexthdr == NEXTHDR_ICMP) {
u8 icmp_type, *icmp_typep;
icmp_typep = skb_header_pointer(skb, payload_off +
offsetof(struct icmp6hdr,
icmp6_type),
sizeof(icmp_type), &icmp_type);
if (!icmp_typep || !(*icmp_typep & ICMPV6_INFOMSG_MASK))
return false;
}
return true;
}
static void ipv6_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
unsigned int mtu, unsigned int payload_length)
{
struct ipv6hdr *ipv6h, *old_ipv6h = ipv6_hdr(skb);
struct icmp6hdr *icmp6h;
u8 *payload;
ipv6h = (struct ipv6hdr *)skb_put(nskb, sizeof(struct ipv6hdr));
icmp6h = (struct icmp6hdr *)skb_put(nskb, sizeof(struct icmp6hdr));
payload = skb_put(nskb, payload_length);
/* IPv6 */
ipv6h->version = 6;
ipv6h->priority = 0;
memset(&ipv6h->flow_lbl, 0, sizeof(ipv6h->flow_lbl));
ipv6h->payload_len = htons(sizeof(struct icmp6hdr)
+ payload_length);
ipv6h->nexthdr = NEXTHDR_ICMP;
ipv6h->hop_limit = IPV6_DEFAULT_HOPLIMIT;
ipv6h->daddr = old_ipv6h->saddr;
ipv6h->saddr = old_ipv6h->daddr;
/* ICMPv6 */
icmp6h->icmp6_type = ICMPV6_PKT_TOOBIG;
icmp6h->icmp6_code = 0;
icmp6h->icmp6_cksum = 0;
icmp6h->icmp6_mtu = htonl(mtu);
nskb->csum = csum_partial((u8 *)icmp6h, sizeof(struct icmp6hdr), 0);
nskb->csum = skb_copy_and_csum_bits(skb, (u8 *)old_ipv6h - skb->data,
payload, payload_length,
nskb->csum);
icmp6h->icmp6_cksum = csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr,
sizeof(struct icmp6hdr)
+ payload_length,
ipv6h->nexthdr, nskb->csum);
}
#endif /* IPv6 */
bool ovs_tnl_frag_needed(struct vport *vport,
const struct tnl_mutable_config *mutable,
struct sk_buff *skb, unsigned int mtu)
{
unsigned int eth_hdr_len = ETH_HLEN;
unsigned int total_length = 0, header_length = 0, payload_length;
struct ethhdr *eh, *old_eh = eth_hdr(skb);
struct sk_buff *nskb;
/* Sanity check */
if (skb->protocol == htons(ETH_P_IP)) {
if (mtu < IP_MIN_MTU)
return false;
if (!ipv4_should_icmp(skb))
return true;
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
else if (skb->protocol == htons(ETH_P_IPV6)) {
if (mtu < IPV6_MIN_MTU)
return false;
/*
* In theory we should do PMTUD on IPv6 multicast messages but
* we don't have an address to send from so just fragment.
*/
if (ipv6_addr_type(&ipv6_hdr(skb)->daddr) & IPV6_ADDR_MULTICAST)
return false;
if (!ipv6_should_icmp(skb))
return true;
}
#endif
else
return false;
/* Allocate */
if (old_eh->h_proto == htons(ETH_P_8021Q))
eth_hdr_len = VLAN_ETH_HLEN;
payload_length = skb->len - eth_hdr_len;
if (skb->protocol == htons(ETH_P_IP)) {
header_length = sizeof(struct iphdr) + sizeof(struct icmphdr);
total_length = min_t(unsigned int, header_length +
payload_length, 576);
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
else {
header_length = sizeof(struct ipv6hdr) +
sizeof(struct icmp6hdr);
total_length = min_t(unsigned int, header_length +
payload_length, IPV6_MIN_MTU);
}
#endif
payload_length = total_length - header_length;
nskb = dev_alloc_skb(NET_IP_ALIGN + eth_hdr_len + header_length +
payload_length);
if (!nskb)
return false;
skb_reserve(nskb, NET_IP_ALIGN);
/* Ethernet / VLAN */
eh = (struct ethhdr *)skb_put(nskb, eth_hdr_len);
memcpy(eh->h_dest, old_eh->h_source, ETH_ALEN);
memcpy(eh->h_source, mutable->eth_addr, ETH_ALEN);
nskb->protocol = eh->h_proto = old_eh->h_proto;
if (old_eh->h_proto == htons(ETH_P_8021Q)) {
struct vlan_ethhdr *vh = (struct vlan_ethhdr *)eh;
vh->h_vlan_TCI = vlan_eth_hdr(skb)->h_vlan_TCI;
vh->h_vlan_encapsulated_proto = skb->protocol;
} else
vlan_set_tci(nskb, vlan_get_tci(skb));
skb_reset_mac_header(nskb);
/* Protocol */
if (skb->protocol == htons(ETH_P_IP))
ipv4_build_icmp(skb, nskb, mtu, payload_length);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
else
ipv6_build_icmp(skb, nskb, mtu, payload_length);
#endif
if (unlikely(compute_ip_summed(nskb, false))) {
kfree_skb(nskb);
return false;
}
ovs_vport_receive(vport, nskb);
return true;
}
static bool check_mtu(struct sk_buff *skb,
struct vport *vport,
const struct tnl_mutable_config *mutable,
const struct rtable *rt, __be16 *frag_offp,
int tunnel_hlen)
{
bool df_inherit;
bool pmtud;
__be16 frag_off;
int mtu = 0;
unsigned int packet_length = skb->len - ETH_HLEN;
if (OVS_CB(skb)->tun_key->ipv4_dst) {
df_inherit = false;
pmtud = false;
frag_off = OVS_CB(skb)->tun_key->tun_flags & OVS_TNL_F_DONT_FRAGMENT ?
htons(IP_DF) : 0;
} else {
df_inherit = mutable->flags & TNL_F_DF_INHERIT;
pmtud = mutable->flags & TNL_F_PMTUD;
frag_off = mutable->flags & TNL_F_DF_DEFAULT ? htons(IP_DF) : 0;
}
/* Allow for one level of tagging in the packet length. */
if (!vlan_tx_tag_present(skb) &&
eth_hdr(skb)->h_proto == htons(ETH_P_8021Q))
packet_length -= VLAN_HLEN;
if (pmtud) {
int vlan_header = 0;
/* The tag needs to go in packet regardless of where it
* currently is, so subtract it from the MTU.
*/
if (vlan_tx_tag_present(skb) ||
eth_hdr(skb)->h_proto == htons(ETH_P_8021Q))
vlan_header = VLAN_HLEN;
mtu = dst_mtu(&rt_dst(rt))
- ETH_HLEN
- tunnel_hlen
- vlan_header;
}
if (skb->protocol == htons(ETH_P_IP)) {
struct iphdr *iph = ip_hdr(skb);
if (df_inherit)
frag_off = iph->frag_off & htons(IP_DF);
if (pmtud && iph->frag_off & htons(IP_DF)) {
mtu = max(mtu, IP_MIN_MTU);
if (packet_length > mtu &&
ovs_tnl_frag_needed(vport, mutable, skb, mtu))
return false;
}
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
else if (skb->protocol == htons(ETH_P_IPV6)) {
/* IPv6 requires end hosts to do fragmentation
* if the packet is above the minimum MTU.
*/
if (df_inherit && packet_length > IPV6_MIN_MTU)
frag_off = htons(IP_DF);
if (pmtud) {
mtu = max(mtu, IPV6_MIN_MTU);
if (packet_length > mtu &&
ovs_tnl_frag_needed(vport, mutable, skb, mtu))
return false;
}
}
#endif
*frag_offp = frag_off;
return true;
}
static struct rtable *find_route(struct net *net,
__be32 *saddr, __be32 daddr, u8 ipproto,
u8 tos)
{
struct rtable *rt;
/* Tunnel configuration keeps DSCP part of TOS bits, But Linux
* router expect RT_TOS bits only. */
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)
struct flowi fl = { .nl_u = { .ip4_u = {
.daddr = daddr,
.saddr = *saddr,
.tos = RT_TOS(tos) } },
.proto = ipproto };
if (unlikely(ip_route_output_key(net, &rt, &fl)))
return ERR_PTR(-EADDRNOTAVAIL);
*saddr = fl.nl_u.ip4_u.saddr;
return rt;
#else
struct flowi4 fl = { .daddr = daddr,
.saddr = *saddr,
.flowi4_tos = RT_TOS(tos),
.flowi4_proto = ipproto };
rt = ip_route_output_key(net, &fl);
*saddr = fl.saddr;
return rt;
#endif
}
static bool need_linearize(const struct sk_buff *skb)
{
int i;
if (unlikely(skb_shinfo(skb)->frag_list))
return true;
/*
* Generally speaking we should linearize if there are paged frags.
* However, if all of the refcounts are 1 we know nobody else can
* change them from underneath us and we can skip the linearization.
*/
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
if (unlikely(page_count(skb_frag_page(&skb_shinfo(skb)->frags[i])) > 1))
return true;
return false;
}
static struct sk_buff *handle_offloads(struct sk_buff *skb,
const struct tnl_mutable_config *mutable,
const struct rtable *rt,
int tunnel_hlen)
{
int min_headroom;
int err;
min_headroom = LL_RESERVED_SPACE(rt_dst(rt).dev) + rt_dst(rt).header_len
+ tunnel_hlen
+ (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
int head_delta = SKB_DATA_ALIGN(min_headroom -
skb_headroom(skb) +
16);
err = pskb_expand_head(skb, max_t(int, head_delta, 0),
0, GFP_ATOMIC);
if (unlikely(err))
goto error_free;
}
forward_ip_summed(skb, true);
if (skb_is_gso(skb)) {
struct sk_buff *nskb;
nskb = skb_gso_segment(skb, 0);
if (IS_ERR(nskb)) {
kfree_skb(skb);
err = PTR_ERR(nskb);
goto error;
}
consume_skb(skb);
skb = nskb;
} else if (get_ip_summed(skb) == OVS_CSUM_PARTIAL) {
/* Pages aren't locked and could change at any time.
* If this happens after we compute the checksum, the
* checksum will be wrong. We linearize now to avoid
* this problem.
*/
if (unlikely(need_linearize(skb))) {
err = __skb_linearize(skb);
if (unlikely(err))
goto error_free;
}
err = skb_checksum_help(skb);
if (unlikely(err))
goto error_free;
}
set_ip_summed(skb, OVS_CSUM_NONE);
return skb;
error_free:
kfree_skb(skb);
error:
return ERR_PTR(err);
}
static int send_frags(struct sk_buff *skb,
int tunnel_hlen)
{
int sent_len;
sent_len = 0;
while (skb) {
struct sk_buff *next = skb->next;
int frag_len = skb->len - tunnel_hlen;
int err;
skb->next = NULL;
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
err = ip_local_out(skb);
skb = next;
if (unlikely(net_xmit_eval(err)))
goto free_frags;
sent_len += frag_len;
}
return sent_len;
free_frags:
/*
* There's no point in continuing to send fragments once one has been
* dropped so just free the rest. This may help improve the congestion
* that caused the first packet to be dropped.
*/
ovs_tnl_free_linked_skbs(skb);
return sent_len;
}
int ovs_tnl_send(struct vport *vport, struct sk_buff *skb)
{
struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
const struct tnl_mutable_config *mutable = rcu_dereference(tnl_vport->mutable);
enum vport_err_type err = VPORT_E_TX_ERROR;
struct rtable *rt;
struct ovs_key_ipv4_tunnel tun_key;
int sent_len = 0;
int tunnel_hlen;
__be16 frag_off = 0;
__be32 daddr;
__be32 saddr;
u8 ttl;
u8 tos;
/* Validate the protocol headers before we try to use them. */
if (skb->protocol == htons(ETH_P_8021Q) &&
!vlan_tx_tag_present(skb)) {
if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
goto error_free;
skb->protocol = vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
skb_set_network_header(skb, VLAN_ETH_HLEN);
}
if (skb->protocol == htons(ETH_P_IP)) {
if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
+ sizeof(struct iphdr))))
skb->protocol = 0;
}
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
else if (skb->protocol == htons(ETH_P_IPV6)) {
if (unlikely(!pskb_may_pull(skb, skb_network_offset(skb)
+ sizeof(struct ipv6hdr))))
skb->protocol = 0;
}
#endif
/* If OVS_CB(skb)->tun_key is NULL, point it at the local tun_key here,
* and zero it out.
*/
if (!OVS_CB(skb)->tun_key) {
memset(&tun_key, 0, sizeof(tun_key));
OVS_CB(skb)->tun_key = &tun_key;
}
tunnel_hlen = tnl_vport->tnl_ops->hdr_len(mutable, OVS_CB(skb)->tun_key);
if (unlikely(tunnel_hlen < 0)) {
err = VPORT_E_TX_DROPPED;
goto error_free;
}
tunnel_hlen += sizeof(struct iphdr);
if (OVS_CB(skb)->tun_key->ipv4_dst) {
daddr = OVS_CB(skb)->tun_key->ipv4_dst;
saddr = OVS_CB(skb)->tun_key->ipv4_src;
tos = OVS_CB(skb)->tun_key->ipv4_tos;
ttl = OVS_CB(skb)->tun_key->ipv4_ttl;
} else {
u8 inner_tos;
daddr = mutable->key.daddr;
saddr = mutable->key.saddr;
if (unlikely(!daddr)) {
/* Trying to sent packet from Null-port without
* tunnel info? Drop this packet. */
err = VPORT_E_TX_DROPPED;
goto error_free;
}
/* ToS */
if (skb->protocol == htons(ETH_P_IP))
inner_tos = ip_hdr(skb)->tos;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
else if (skb->protocol == htons(ETH_P_IPV6))
inner_tos = ipv6_get_dsfield(ipv6_hdr(skb));
#endif
else
inner_tos = 0;
if (mutable->flags & TNL_F_TOS_INHERIT)
tos = inner_tos;
else
tos = mutable->tos;
tos = INET_ECN_encapsulate(tos, inner_tos);
/* TTL */
ttl = mutable->ttl;
if (mutable->flags & TNL_F_TTL_INHERIT) {
if (skb->protocol == htons(ETH_P_IP))
ttl = ip_hdr(skb)->ttl;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
else if (skb->protocol == htons(ETH_P_IPV6))
ttl = ipv6_hdr(skb)->hop_limit;
#endif
}
}
/* Route lookup */
rt = find_route(port_key_get_net(&mutable->key), &saddr, daddr,
tnl_vport->tnl_ops->ipproto, tos);
if (IS_ERR(rt))
goto error_free;
/* Reset SKB */
nf_reset(skb);
secpath_reset(skb);
skb_dst_drop(skb);
skb_clear_rxhash(skb);
/* Offloading */
skb = handle_offloads(skb, mutable, rt, tunnel_hlen);
if (IS_ERR(skb)) {
skb = NULL;
goto err_free_rt;
}
/* MTU */
if (unlikely(!check_mtu(skb, vport, mutable, rt, &frag_off, tunnel_hlen))) {
err = VPORT_E_TX_DROPPED;
goto err_free_rt;
}
/* TTL Fixup. */
if (!OVS_CB(skb)->tun_key->ipv4_dst) {
if (!(mutable->flags & TNL_F_TTL_INHERIT)) {
if (!ttl)
ttl = ip4_dst_hoplimit(&rt_dst(rt));
}
}
while (skb) {
struct iphdr *iph;
struct sk_buff *next_skb = skb->next;
skb->next = NULL;
if (unlikely(vlan_deaccel_tag(skb)))
goto next;
skb_push(skb, tunnel_hlen);
skb_reset_network_header(skb);
skb_set_transport_header(skb, sizeof(struct iphdr));
if (next_skb)
skb_dst_set(skb, dst_clone(&rt_dst(rt)));
else
skb_dst_set(skb, &rt_dst(rt));
/* Push IP header. */