/
ip6_tunnel.c
2213 lines (1878 loc) · 53.8 KB
/
ip6_tunnel.c
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/*
* IPv6 tunneling device
* Linux INET6 implementation
*
* Authors:
* Ville Nuorvala <vnuorval@tcs.hut.fi>
* Yasuyuki Kozakai <kozakai@linux-ipv6.org>
*
* Based on:
* linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
*
* RFC 2473
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#ifndef USE_UPSTREAM_TUNNEL
#include <linux/module.h>
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/sockios.h>
#include <linux/icmp.h>
#include <linux/if.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/icmpv6.h>
#include <linux/init.h>
#include <linux/route.h>
#include <linux/rtnetlink.h>
#include <linux/netfilter_ipv6.h>
#include <linux/slab.h>
#include <linux/hash.h>
#include <linux/etherdevice.h>
#include <linux/uaccess.h>
#include <linux/atomic.h>
#include <net/icmp.h>
#include <net/ip.h>
#include <net/ip_tunnels.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/ip6_tunnel.h>
#include <net/xfrm.h>
#include <net/dsfield.h>
#include <net/inet_ecn.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include "gso.h"
#include <net/dst_metadata.h>
#include "vport-netdev.h"
#define IP6_TUNNEL_HASH_SIZE_SHIFT 5
#define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
enum {
#ifndef HAVE_IFLA_IPTUN_ENCAP_TYPE
IFLA_IPTUN_ENCAP_TYPE = IFLA_IPTUN_6RD_RELAY_PREFIXLEN + 1,
IFLA_IPTUN_ENCAP_FLAGS,
IFLA_IPTUN_ENCAP_SPORT,
IFLA_IPTUN_ENCAP_DPORT,
#endif
#ifndef HAVE_IFLA_IPTUN_COLLECT_METADATA
IFLA_IPTUN_COLLECT_METADATA = IFLA_IPTUN_ENCAP_DPORT + 1,
#endif
#ifndef HAVE_IFLA_IPTUN_FWMARK
IFLA_IPTUN_FWMARK = IFLA_IPTUN_COLLECT_METADATA + 1,
#endif
RPL__IFLA_IPTUN_MAX = IFLA_IPTUN_FWMARK + 1,
};
#define RPL_IFLA_IPTUN_MAX RPL__IFLA_IPTUN_MAX
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,7,0)
/* Undef the one from ip_tunnels.h - we need a different one here */
/* At least I think... */
#undef iptunnel_handle_offloads
/* gre_handle_offloads() has different return type on older kernsl. */
static void gre_nop_fix(struct sk_buff *skb) { }
static void gre_csum_fix(struct sk_buff *skb)
{
struct gre_base_hdr *greh;
__be32 *options;
int gre_offset = skb_transport_offset(skb);
greh = (struct gre_base_hdr *)skb_transport_header(skb);
options = ((__be32 *)greh + 1);
*options = 0;
*(__sum16 *)options = csum_fold(skb_checksum(skb, gre_offset,
skb->len - gre_offset, 0));
}
#define iptunnel_handle_offloads rpl__iptunnel_handle_offloads
static int rpl__iptunnel_handle_offloads(struct sk_buff *skb, bool gre_csum,
int __always_unused ignored)
{
int type = gre_csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE;
gso_fix_segment_t fix_segment;
if (gre_csum)
fix_segment = gre_csum_fix;
else
fix_segment = gre_nop_fix;
return ovs_iptunnel_handle_offloads(skb, type, fix_segment);
}
#endif
static bool log_ecn_error = true;
static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
{
u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
}
static int ip6_tnl_dev_init(struct net_device *dev);
static void ip6_tnl_dev_setup(struct net_device *dev);
static struct rtnl_link_ops ip6_link_ops __read_mostly;
static unsigned int ip6_tnl_net_id __read_mostly;
struct ip6_tnl_net {
/* the IPv6 tunnel fallback device */
struct net_device *fb_tnl_dev;
/* lists for storing tunnels in use */
struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
struct ip6_tnl __rcu *tnls_wc[1];
struct ip6_tnl __rcu **tnls[2];
struct ip6_tnl __rcu *collect_md_tun;
};
static struct net_device_stats *ip6_get_stats(struct net_device *dev)
{
struct pcpu_sw_netstats tmp, sum = { 0 };
int i;
for_each_possible_cpu(i) {
unsigned int start;
const struct pcpu_sw_netstats *tstats =
per_cpu_ptr(dev->tstats, i);
do {
start = u64_stats_fetch_begin_irq(&tstats->syncp);
tmp.rx_packets = tstats->rx_packets;
tmp.rx_bytes = tstats->rx_bytes;
tmp.tx_packets = tstats->tx_packets;
tmp.tx_bytes = tstats->tx_bytes;
} while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
sum.rx_packets += tmp.rx_packets;
sum.rx_bytes += tmp.rx_bytes;
sum.tx_packets += tmp.tx_packets;
sum.tx_bytes += tmp.tx_bytes;
}
dev->stats.rx_packets = sum.rx_packets;
dev->stats.rx_bytes = sum.rx_bytes;
dev->stats.tx_packets = sum.tx_packets;
dev->stats.tx_bytes = sum.tx_bytes;
return &dev->stats;
}
/**
* ip6_tnl_lookup - fetch tunnel matching the end-point addresses
* @remote: the address of the tunnel exit-point
* @local: the address of the tunnel entry-point
*
* Return:
* tunnel matching given end-points if found,
* else fallback tunnel if its device is up,
* else %NULL
**/
#define for_each_ip6_tunnel_rcu(start) \
for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
static struct ip6_tnl *
ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
{
unsigned int hash = HASH(remote, local);
struct ip6_tnl *t;
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
struct in6_addr any;
for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
if (ipv6_addr_equal(local, &t->parms.laddr) &&
ipv6_addr_equal(remote, &t->parms.raddr) &&
(t->dev->flags & IFF_UP))
return t;
}
memset(&any, 0, sizeof(any));
hash = HASH(&any, local);
for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
if (ipv6_addr_equal(local, &t->parms.laddr) &&
ipv6_addr_any(&t->parms.raddr) &&
(t->dev->flags & IFF_UP))
return t;
}
hash = HASH(remote, &any);
for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
if (ipv6_addr_equal(remote, &t->parms.raddr) &&
ipv6_addr_any(&t->parms.laddr) &&
(t->dev->flags & IFF_UP))
return t;
}
t = rcu_dereference(ip6n->collect_md_tun);
if (t && t->dev->flags & IFF_UP)
return t;
t = rcu_dereference(ip6n->tnls_wc[0]);
if (t && (t->dev->flags & IFF_UP))
return t;
return NULL;
}
/**
* ip6_tnl_bucket - get head of list matching given tunnel parameters
* @p: parameters containing tunnel end-points
*
* Description:
* ip6_tnl_bucket() returns the head of the list matching the
* &struct in6_addr entries laddr and raddr in @p.
*
* Return: head of IPv6 tunnel list
**/
static struct ip6_tnl __rcu **
ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
{
const struct in6_addr *remote = &p->raddr;
const struct in6_addr *local = &p->laddr;
unsigned int h = 0;
int prio = 0;
if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
prio = 1;
h = HASH(remote, local);
}
return &ip6n->tnls[prio][h];
}
/**
* ip6_tnl_link - add tunnel to hash table
* @t: tunnel to be added
**/
static void
ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
{
struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
if (t->parms.collect_md)
rcu_assign_pointer(ip6n->collect_md_tun, t);
rcu_assign_pointer(t->next , rtnl_dereference(*tp));
rcu_assign_pointer(*tp, t);
}
/**
* ip6_tnl_unlink - remove tunnel from hash table
* @t: tunnel to be removed
**/
static void
ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
{
struct ip6_tnl __rcu **tp;
struct ip6_tnl *iter;
if (t->parms.collect_md)
rcu_assign_pointer(ip6n->collect_md_tun, NULL);
for (tp = ip6_tnl_bucket(ip6n, &t->parms);
(iter = rtnl_dereference(*tp)) != NULL;
tp = &iter->next) {
if (t == iter) {
rcu_assign_pointer(*tp, t->next);
break;
}
}
}
#ifdef HAVE_NEEDS_FREE_NETDEV
static void ip6_dev_free(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
gro_cells_destroy(&t->gro_cells);
dst_cache_destroy(&t->dst_cache);
free_percpu(dev->tstats);
}
#endif
static int ip6_tnl_create2(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
struct net *net = dev_net(dev);
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
int err;
t = netdev_priv(dev);
dev->rtnl_link_ops = &ip6_link_ops;
err = register_netdevice(dev);
if (err < 0)
goto out;
strcpy(t->parms.name, dev->name);
dev_hold(dev);
ip6_tnl_link(ip6n, t);
return 0;
out:
return err;
}
/**
* ip6_tnl_create - create a new tunnel
* @p: tunnel parameters
* @pt: pointer to new tunnel
*
* Description:
* Create tunnel matching given parameters.
*
* Return:
* created tunnel or error pointer
**/
static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
{
struct net_device *dev;
struct ip6_tnl *t;
char name[IFNAMSIZ];
int err = -ENOMEM;
if (p->name[0])
strlcpy(name, p->name, IFNAMSIZ);
else
sprintf(name, "ip6tnl%%d");
dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
ip6_tnl_dev_setup);
if (!dev)
goto failed;
dev_net_set(dev, net);
t = netdev_priv(dev);
t->parms = *p;
t->net = dev_net(dev);
err = ip6_tnl_create2(dev);
if (err < 0)
goto failed_free;
return t;
failed_free:
free_netdev(dev);
failed:
return ERR_PTR(err);
}
/**
* ip6_tnl_locate - find or create tunnel matching given parameters
* @p: tunnel parameters
* @create: != 0 if allowed to create new tunnel if no match found
*
* Description:
* ip6_tnl_locate() first tries to locate an existing tunnel
* based on @parms. If this is unsuccessful, but @create is set a new
* tunnel device is created and registered for use.
*
* Return:
* matching tunnel or error pointer
**/
static struct ip6_tnl *ip6_tnl_locate(struct net *net,
struct __ip6_tnl_parm *p, int create)
{
const struct in6_addr *remote = &p->raddr;
const struct in6_addr *local = &p->laddr;
struct ip6_tnl __rcu **tp;
struct ip6_tnl *t;
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
for (tp = ip6_tnl_bucket(ip6n, p);
(t = rtnl_dereference(*tp)) != NULL;
tp = &t->next) {
if (ipv6_addr_equal(local, &t->parms.laddr) &&
ipv6_addr_equal(remote, &t->parms.raddr)) {
if (create)
return ERR_PTR(-EEXIST);
return t;
}
}
if (!create)
return ERR_PTR(-ENODEV);
return ip6_tnl_create(net, p);
}
/**
* ip6_tnl_dev_uninit - tunnel device uninitializer
* @dev: the device to be destroyed
*
* Description:
* ip6_tnl_dev_uninit() removes tunnel from its list
**/
static void
ip6_tnl_dev_uninit(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
struct net *net = t->net;
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
if (dev == ip6n->fb_tnl_dev)
RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
else
ip6_tnl_unlink(ip6n, t);
dst_cache_reset(&t->dst_cache);
dev_put(dev);
}
/**
* parse_tvl_tnl_enc_lim - handle encapsulation limit option
* @skb: received socket buffer
*
* Return:
* 0 if none was found,
* else index to encapsulation limit
**/
__u16 rpl_ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
{
const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
unsigned int nhoff = raw - skb->data;
unsigned int off = nhoff + sizeof(*ipv6h);
u8 next, nexthdr = ipv6h->nexthdr;
while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
struct ipv6_opt_hdr *hdr;
u16 optlen;
if (!pskb_may_pull(skb, off + sizeof(*hdr)))
break;
hdr = (struct ipv6_opt_hdr *)(skb->data + off);
if (nexthdr == NEXTHDR_FRAGMENT) {
struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
if (frag_hdr->frag_off)
break;
optlen = 8;
} else if (nexthdr == NEXTHDR_AUTH) {
optlen = (hdr->hdrlen + 2) << 2;
} else {
optlen = ipv6_optlen(hdr);
}
/* cache hdr->nexthdr, since pskb_may_pull() might
* invalidate hdr
*/
next = hdr->nexthdr;
if (nexthdr == NEXTHDR_DEST) {
u16 i = 2;
/* Remember : hdr is no longer valid at this point. */
if (!pskb_may_pull(skb, off + optlen))
break;
while (1) {
struct ipv6_tlv_tnl_enc_lim *tel;
/* No more room for encapsulation limit */
if (i + sizeof(*tel) > optlen)
break;
tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
/* return index of option if found and valid */
if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
tel->length == 1)
return i + off - nhoff;
/* else jump to next option */
if (tel->type)
i += tel->length + 2;
else
i++;
}
}
nexthdr = next;
off += optlen;
}
return 0;
}
static int
ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
return PACKET_REJECT;
}
static int
ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
return PACKET_REJECT;
}
static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
const struct ipv6hdr *ipv6h,
struct sk_buff *skb)
{
__u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
return IP6_ECN_decapsulate(ipv6h, skb);
}
static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
const struct ipv6hdr *ipv6h,
struct sk_buff *skb)
{
if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
return IP6_ECN_decapsulate(ipv6h, skb);
}
__u32 rpl_ip6_tnl_get_cap(struct ip6_tnl *t,
const struct in6_addr *laddr,
const struct in6_addr *raddr)
{
struct __ip6_tnl_parm *p = &t->parms;
int ltype = ipv6_addr_type(laddr);
int rtype = ipv6_addr_type(raddr);
__u32 flags = 0;
if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
flags = IP6_TNL_F_CAP_PER_PACKET;
} else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
!((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
(!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
if (ltype&IPV6_ADDR_UNICAST)
flags |= IP6_TNL_F_CAP_XMIT;
if (rtype&IPV6_ADDR_UNICAST)
flags |= IP6_TNL_F_CAP_RCV;
}
return flags;
}
/* called with rcu_read_lock() */
int rpl_ip6_tnl_rcv_ctl(struct ip6_tnl *t,
const struct in6_addr *laddr,
const struct in6_addr *raddr)
{
struct __ip6_tnl_parm *p = &t->parms;
int ret = 0;
struct net *net = t->net;
if ((p->flags & IP6_TNL_F_CAP_RCV) ||
((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
(rpl_ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
struct net_device *ldev = NULL;
if (p->link)
ldev = dev_get_by_index_rcu(net, p->link);
if ((ipv6_addr_is_multicast(laddr) ||
likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
likely(!ipv6_chk_addr(net, raddr, NULL, 0))))
ret = 1;
}
return ret;
}
static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
const struct tnl_ptk_info *tpi,
struct metadata_dst *tun_dst,
int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
const struct ipv6hdr *ipv6h,
struct sk_buff *skb),
bool log_ecn_err)
{
struct pcpu_sw_netstats *tstats;
if ((!(tpi->flags & TUNNEL_CSUM) &&
(tunnel->parms.i_flags & TUNNEL_CSUM)) ||
((tpi->flags & TUNNEL_CSUM) &&
!(tunnel->parms.i_flags & TUNNEL_CSUM))) {
tunnel->dev->stats.rx_crc_errors++;
tunnel->dev->stats.rx_errors++;
goto drop;
}
if (tunnel->parms.i_flags & TUNNEL_SEQ) {
if (!(tpi->flags & TUNNEL_SEQ) ||
(tunnel->i_seqno &&
(s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
tunnel->dev->stats.rx_fifo_errors++;
tunnel->dev->stats.rx_errors++;
goto drop;
}
tunnel->i_seqno = ntohl(tpi->seq) + 1;
}
#if 0
/* Warning: All skb pointers will be invalidated! */
if (tunnel->dev->type == ARPHRD_ETHER) {
if (!pskb_may_pull(skb, ETH_HLEN)) {
tunnel->dev->stats.rx_length_errors++;
tunnel->dev->stats.rx_errors++;
goto drop;
}
ipv6h = ipv6_hdr(skb);
skb->protocol = eth_type_trans(skb, tunnel->dev);
skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
} else {
skb->dev = tunnel->dev;
}
skb_reset_network_header(skb);
memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
if (unlikely(err)) {
if (log_ecn_err)
net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
&ipv6h->saddr,
ipv6_get_dsfield(ipv6h));
if (err > 1) {
++tunnel->dev->stats.rx_frame_errors;
++tunnel->dev->stats.rx_errors;
goto drop;
}
}
#endif
tstats = this_cpu_ptr(tunnel->dev->tstats);
u64_stats_update_begin(&tstats->syncp);
tstats->rx_packets++;
tstats->rx_bytes += skb->len;
u64_stats_update_end(&tstats->syncp);
skb_reset_mac_header(skb);
skb_scrub_packet(skb, false);
skb->protocol = eth_type_trans(skb, tunnel->dev);
skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
ovs_skb_dst_set(skb, (struct dst_entry *)tun_dst);
netdev_port_receive(skb, &tun_dst->u.tun_info);
return 0;
drop:
/* In OVS case caller will free tun_dst and skb */
#if 0
if (tun_dst)
dst_release((struct dst_entry *)tun_dst);
kfree_skb(skb);
#endif
return 0;
}
int rpl_ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
const struct tnl_ptk_info *tpi,
struct metadata_dst *tun_dst,
bool log_ecn_err)
{
return __ip6_tnl_rcv(t, skb, tpi, tun_dst, ip6ip6_dscp_ecn_decapsulate,
log_ecn_err);
}
static const struct tnl_ptk_info tpi_v6 = {
/* no tunnel info required for ipxip6. */
.proto = htons(ETH_P_IPV6),
};
static const struct tnl_ptk_info tpi_v4 = {
/* no tunnel info required for ipxip6. */
.proto = htons(ETH_P_IP),
};
static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
const struct tnl_ptk_info *tpi,
int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
const struct ipv6hdr *ipv6h,
struct sk_buff *skb))
{
struct ip6_tnl *t;
const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
struct metadata_dst *tun_dst = NULL;
int ret = -1;
rcu_read_lock();
t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
if (t) {
u8 tproto = READ_ONCE(t->parms.proto);
if (tproto != ipproto && tproto != 0)
goto drop;
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
goto drop;
if (!rpl_ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
goto drop;
if (iptunnel_pull_header(skb, 0, tpi->proto, false))
goto drop;
if (t->parms.collect_md) {
ovs_ipv6_tun_rx_dst(tun_dst, skb, 0, 0, 0);
if (!tun_dst)
goto drop;
}
ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
log_ecn_error);
}
rcu_read_unlock();
return ret;
drop:
rcu_read_unlock();
kfree_skb(skb);
return 0;
}
static int ip4ip6_rcv(struct sk_buff *skb)
{
return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
ip4ip6_dscp_ecn_decapsulate);
}
static int ip6ip6_rcv(struct sk_buff *skb)
{
return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
ip6ip6_dscp_ecn_decapsulate);
}
struct ipv6_tel_txoption {
struct ipv6_txoptions ops;
__u8 dst_opt[8];
};
static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
{
memset(opt, 0, sizeof(struct ipv6_tel_txoption));
opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
opt->dst_opt[3] = 1;
opt->dst_opt[4] = encap_limit;
opt->dst_opt[5] = IPV6_TLV_PADN;
opt->dst_opt[6] = 1;
opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
opt->ops.opt_nflen = 8;
}
/**
* ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
* @t: the outgoing tunnel device
* @hdr: IPv6 header from the incoming packet
*
* Description:
* Avoid trivial tunneling loop by checking that tunnel exit-point
* doesn't match source of incoming packet.
*
* Return:
* 1 if conflict,
* 0 else
**/
static inline bool
ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
{
return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
}
int rpl_ip6_tnl_xmit_ctl(struct ip6_tnl *t,
const struct in6_addr *laddr,
const struct in6_addr *raddr)
{
struct __ip6_tnl_parm *p = &t->parms;
int ret = 0;
struct net *net = t->net;
if (t->parms.collect_md)
return 1;
if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
(rpl_ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
struct net_device *ldev = NULL;
rcu_read_lock();
if (p->link)
ldev = dev_get_by_index_rcu(net, p->link);
if (unlikely(!ipv6_chk_addr(net, laddr, ldev, 0)))
pr_warn("%s xmit: Local address not yet configured!\n",
p->name);
else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
!ipv6_addr_is_multicast(raddr) &&
unlikely(ipv6_chk_addr(net, raddr, NULL, 0)))
pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
p->name);
else
ret = 1;
rcu_read_unlock();
}
return ret;
}
static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto,
u8 type, struct ipv6_opt_hdr *opt)
{
struct ipv6_opt_hdr *h =
(struct ipv6_opt_hdr *)skb_push(skb, ipv6_optlen(opt));
memcpy(h, opt, ipv6_optlen(opt));
h->nexthdr = *proto;
*proto = type;
}
void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
u8 *proto)
{
if (opt->dst1opt)
ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
}
/**
* ip6_tnl_xmit - encapsulate packet and send
* @skb: the outgoing socket buffer
* @dev: the outgoing tunnel device
* @dsfield: dscp code for outer header
* @fl6: flow of tunneled packet
* @encap_limit: encapsulation limit
* @pmtu: Path MTU is stored if packet is too big
* @proto: next header value
*
* Description:
* Build new header and do some sanity checks on the packet before sending
* it.
*
* Return:
* 0 on success
* -1 fail
* %-EMSGSIZE message too big. return mtu in this case.
**/
int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
__u8 proto)
{
struct ip6_tnl *t = netdev_priv(dev);
struct net *net = t->net;
struct net_device_stats *stats = &t->dev->stats;
struct ipv6hdr *ipv6h;
struct ipv6_tel_txoption opt;
struct dst_entry *dst = NULL, *ndst = NULL;
struct net_device *tdev;
int mtu;
unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
unsigned int max_headroom = psh_hlen;
bool use_cache = false;
u8 hop_limit;
int err = -1;
if (t->parms.collect_md) {
hop_limit = skb_tunnel_info(skb)->key.ttl;
goto route_lookup;
} else {
hop_limit = t->parms.hop_limit;
}
/* NBMA tunnel */
if (ipv6_addr_any(&t->parms.raddr)) {
if (skb->protocol == htons(ETH_P_IPV6)) {
struct in6_addr *addr6;
struct neighbour *neigh;
int addr_type;
if (!skb_dst(skb))
goto tx_err_link_failure;
neigh = dst_neigh_lookup(skb_dst(skb),
&ipv6_hdr(skb)->daddr);
if (!neigh)
goto tx_err_link_failure;
addr6 = (struct in6_addr *)&neigh->primary_key;
addr_type = ipv6_addr_type(addr6);
if (addr_type == IPV6_ADDR_ANY)
addr6 = &ipv6_hdr(skb)->daddr;
memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
neigh_release(neigh);
}
} else if (t->parms.proto != 0 && !(t->parms.flags &
(IP6_TNL_F_USE_ORIG_TCLASS |
IP6_TNL_F_USE_ORIG_FWMARK))) {
/* enable the cache only if neither the outer protocol nor the
* routing decision depends on the current inner header value
*/
use_cache = true;
}
if (use_cache)
dst = dst_cache_get(&t->dst_cache);
if (!rpl_ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
goto tx_err_link_failure;
if (!dst) {
route_lookup:
/* add dsfield to flowlabel for route lookup */
fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
dst = ip6_route_output(net, NULL, fl6);
if (dst->error)
goto tx_err_link_failure;
dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
if (IS_ERR(dst)) {
err = PTR_ERR(dst);
dst = NULL;
goto tx_err_link_failure;
}
if (t->parms.collect_md &&
ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
&fl6->daddr, 0, &fl6->saddr))
goto tx_err_link_failure;
ndst = dst;
}
tdev = dst->dev;
if (tdev == dev) {
stats->collisions++;
net_warn_ratelimited("%s: Local routing loop detected!\n",
t->parms.name);
goto tx_err_dst_release;
}
mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
if (encap_limit >= 0) {
max_headroom += 8;
mtu -= 8;
}
if (skb->protocol == htons(ETH_P_IPV6)) {
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
} else if (mtu < 576) {
mtu = 576;
}
// FIX ME
// skb_dst_update_pmtu(skb, mtu);
if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
*pmtu = mtu;
err = -EMSGSIZE;
goto tx_err_dst_release;
}
if (t->err_count > 0) {
if (time_before(jiffies,
t->err_time + IP6TUNNEL_ERR_TIMEO)) {
t->err_count--;
dst_link_failure(skb);
} else {
t->err_count = 0;
}
}