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ip6_tunnel.c
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IPv6 tunneling device
* Linux INET6 implementation
*
* Authors:
* Ville Nuorvala <[email protected]>
* Yasuyuki Kozakai <[email protected]>
*
* Based on:
* linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
*
* RFC 2473
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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 <net/dst_metadata.h>
MODULE_AUTHOR("Ville Nuorvala");
MODULE_DESCRIPTION("IPv6 tunneling device");
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK("ip6tnl");
MODULE_ALIAS_NETDEV("ip6tnl0");
#define IP6_TUNNEL_HASH_SIZE_SHIFT 5
#define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
static bool log_ecn_error = true;
module_param(log_ecn_error, bool, 0644);
MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
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 inline int ip6_tnl_mpls_supported(void)
{
return IS_ENABLED(CONFIG_MPLS);
}
#define for_each_ip6_tunnel_rcu(start) \
for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
/**
* ip6_tnl_lookup - fetch tunnel matching the end-point addresses
* @net: network namespace
* @link: ifindex of underlying interface
* @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
**/
static struct ip6_tnl *
ip6_tnl_lookup(struct net *net, int link,
const struct in6_addr *remote, const struct in6_addr *local)
{
unsigned int hash = HASH(remote, local);
struct ip6_tnl *t, *cand = NULL;
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))
continue;
if (link == t->parms.link)
return t;
else
cand = 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))
continue;
if (link == t->parms.link)
return t;
else if (!cand)
cand = 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))
continue;
if (link == t->parms.link)
return t;
else if (!cand)
cand = t;
}
if (cand)
return cand;
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
* @ip6n: the private data for ip6_vti in the netns
* @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
* @ip6n: the private data for ip6_vti in the netns
* @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
* @ip6n: the private data for ip6_vti in the netns
* @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;
}
}
}
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);
}
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;
dev->rtnl_link_ops = &ip6_link_ops;
err = register_netdevice(dev);
if (err < 0)
goto out;
strcpy(t->parms.name, dev->name);
ip6_tnl_link(ip6n, t);
return 0;
out:
return err;
}
/**
* ip6_tnl_create - create a new tunnel
* @net: network namespace
* @p: tunnel parameters
*
* 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 = -E2BIG;
if (p->name[0]) {
if (!dev_valid_name(p->name))
goto failed;
strscpy(name, p->name, IFNAMSIZ);
} else {
sprintf(name, "ip6tnl%%d");
}
err = -ENOMEM;
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
* @net: network namespace
* @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) &&
p->link == t->parms.link) {
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);
netdev_put(dev, &t->dev_tracker);
}
/**
* ip6_tnl_parse_tlv_enc_lim - handle encapsulation limit option
* @skb: received socket buffer
* @raw: the ICMPv6 error message data
*
* Return:
* 0 if none was found,
* else index to encapsulation limit
**/
__u16 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 = ipv6_authlen(hdr);
} 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;
}
EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
/* ip6_tnl_err() should handle errors in the tunnel according to the
* specifications in RFC 2473.
*/
static int
ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
u8 *type, u8 *code, int *msg, __u32 *info, int offset)
{
const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
struct net *net = dev_net(skb->dev);
u8 rel_type = ICMPV6_DEST_UNREACH;
u8 rel_code = ICMPV6_ADDR_UNREACH;
__u32 rel_info = 0;
struct ip6_tnl *t;
int err = -ENOENT;
int rel_msg = 0;
u8 tproto;
__u16 len;
/* If the packet doesn't contain the original IPv6 header we are
in trouble since we might need the source address for further
processing of the error. */
rcu_read_lock();
t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->daddr, &ipv6h->saddr);
if (!t)
goto out;
tproto = READ_ONCE(t->parms.proto);
if (tproto != ipproto && tproto != 0)
goto out;
err = 0;
switch (*type) {
case ICMPV6_DEST_UNREACH:
net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
t->parms.name);
rel_msg = 1;
break;
case ICMPV6_TIME_EXCEED:
if ((*code) == ICMPV6_EXC_HOPLIMIT) {
net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
t->parms.name);
rel_msg = 1;
}
break;
case ICMPV6_PARAMPROB: {
struct ipv6_tlv_tnl_enc_lim *tel;
__u32 teli;
teli = 0;
if ((*code) == ICMPV6_HDR_FIELD)
teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
if (teli && teli == *info - 2) {
tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
if (tel->encap_limit == 0) {
net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
t->parms.name);
rel_msg = 1;
}
} else {
net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
t->parms.name);
}
break;
}
case ICMPV6_PKT_TOOBIG: {
__u32 mtu;
ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
sock_net_uid(net, NULL));
mtu = *info - offset;
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
if (len > mtu) {
rel_type = ICMPV6_PKT_TOOBIG;
rel_code = 0;
rel_info = mtu;
rel_msg = 1;
}
break;
}
case NDISC_REDIRECT:
ip6_redirect(skb, net, skb->dev->ifindex, 0,
sock_net_uid(net, NULL));
break;
}
*type = rel_type;
*code = rel_code;
*info = rel_info;
*msg = rel_msg;
out:
rcu_read_unlock();
return err;
}
static int
ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
__u32 rel_info = ntohl(info);
const struct iphdr *eiph;
struct sk_buff *skb2;
int err, rel_msg = 0;
u8 rel_type = type;
u8 rel_code = code;
struct rtable *rt;
struct flowi4 fl4;
err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
&rel_msg, &rel_info, offset);
if (err < 0)
return err;
if (rel_msg == 0)
return 0;
switch (rel_type) {
case ICMPV6_DEST_UNREACH:
if (rel_code != ICMPV6_ADDR_UNREACH)
return 0;
rel_type = ICMP_DEST_UNREACH;
rel_code = ICMP_HOST_UNREACH;
break;
case ICMPV6_PKT_TOOBIG:
if (rel_code != 0)
return 0;
rel_type = ICMP_DEST_UNREACH;
rel_code = ICMP_FRAG_NEEDED;
break;
default:
return 0;
}
if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
return 0;
skb2 = skb_clone(skb, GFP_ATOMIC);
if (!skb2)
return 0;
skb_dst_drop(skb2);
skb_pull(skb2, offset);
skb_reset_network_header(skb2);
eiph = ip_hdr(skb2);
/* Try to guess incoming interface */
rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
if (IS_ERR(rt))
goto out;
skb2->dev = rt->dst.dev;
ip_rt_put(rt);
/* route "incoming" packet */
if (rt->rt_flags & RTCF_LOCAL) {
rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
eiph->daddr, eiph->saddr, 0, 0,
IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
if (!IS_ERR(rt))
ip_rt_put(rt);
goto out;
}
skb_dst_set(skb2, &rt->dst);
} else {
if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
skb2->dev) ||
skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
goto out;
}
/* change mtu on this route */
if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
if (rel_info > dst_mtu(skb_dst(skb2)))
goto out;
skb_dst_update_pmtu_no_confirm(skb2, rel_info);
}
icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
out:
kfree_skb(skb2);
return 0;
}
static int
ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
__u32 rel_info = ntohl(info);
int err, rel_msg = 0;
u8 rel_type = type;
u8 rel_code = code;
err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
&rel_msg, &rel_info, offset);
if (err < 0)
return err;
if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
struct rt6_info *rt;
struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
if (!skb2)
return 0;
skb_dst_drop(skb2);
skb_pull(skb2, offset);
skb_reset_network_header(skb2);
/* Try to guess incoming interface */
rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
NULL, 0, skb2, 0);
if (rt && rt->dst.dev)
skb2->dev = rt->dst.dev;
icmpv6_send(skb2, rel_type, rel_code, rel_info);
ip6_rt_put(rt);
kfree_skb(skb2);
}
return 0;
}
static int
mplsip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
__u32 rel_info = ntohl(info);
int err, rel_msg = 0;
u8 rel_type = type;
u8 rel_code = code;
err = ip6_tnl_err(skb, IPPROTO_MPLS, opt, &rel_type, &rel_code,
&rel_msg, &rel_info, offset);
return err;
}
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);
}
static inline int mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
const struct ipv6hdr *ipv6h,
struct sk_buff *skb)
{
/* ECN is not supported in AF_MPLS */
return 0;
}
__u32 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;
}
EXPORT_SYMBOL(ip6_tnl_get_cap);
/* called with rcu_read_lock() */
int 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) &&
(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_and_flags(net, laddr, ldev, false,
0, IFA_F_TENTATIVE))) &&
((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
0, IFA_F_TENTATIVE))))
ret = 1;
}
return ret;
}
EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
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)
{
const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
int err;
if ((!(tpi->flags & TUNNEL_CSUM) &&
(tunnel->parms.i_flags & TUNNEL_CSUM)) ||
((tpi->flags & TUNNEL_CSUM) &&
!(tunnel->parms.i_flags & TUNNEL_CSUM))) {
DEV_STATS_INC(tunnel->dev, rx_crc_errors);
DEV_STATS_INC(tunnel->dev, 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)) {
DEV_STATS_INC(tunnel->dev, rx_fifo_errors);
DEV_STATS_INC(tunnel->dev, rx_errors);
goto drop;
}
tunnel->i_seqno = ntohl(tpi->seq) + 1;
}
skb->protocol = tpi->proto;
/* Warning: All skb pointers will be invalidated! */
if (tunnel->dev->type == ARPHRD_ETHER) {
if (!pskb_may_pull(skb, ETH_HLEN)) {
DEV_STATS_INC(tunnel->dev, rx_length_errors);
DEV_STATS_INC(tunnel->dev, 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_mac_header(skb);
}
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) {
DEV_STATS_INC(tunnel->dev, rx_frame_errors);
DEV_STATS_INC(tunnel->dev, rx_errors);
goto drop;
}
}
dev_sw_netstats_rx_add(tunnel->dev, skb->len);
skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
if (tun_dst)
skb_dst_set(skb, (struct dst_entry *)tun_dst);
gro_cells_receive(&tunnel->gro_cells, skb);
return 0;
drop:
if (tun_dst)
dst_release((struct dst_entry *)tun_dst);
kfree_skb(skb);
return 0;
}
int 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)
{
int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
const struct ipv6hdr *ipv6h,
struct sk_buff *skb);
dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;
if (tpi->proto == htons(ETH_P_IP))
dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;
return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
log_ecn_err);
}
EXPORT_SYMBOL(ip6_tnl_rcv);
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 const struct tnl_ptk_info tpi_mpls = {
/* no tunnel info required for mplsip6. */
.proto = htons(ETH_P_MPLS_UC),
};
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), skb->dev->ifindex, &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;
ipv6h = ipv6_hdr(skb);
if (!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) {
tun_dst = ipv6_tun_rx_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);
}
static int mplsip6_rcv(struct sk_buff *skb)
{
return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
mplsip6_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,