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linux/net/ipv6/ip6_tunnel.c
Nicolas Dichtel f4e0b4c5e1 ip6tnl/sit: drop packet if ECN present with not-ECT 
This patch reports the change made by Stephen Hemminger in ipip and gre[6] in
commit eccc1bb8d4 (tunnel: drop packet if ECN present with not-ECT).

Goal is to handle RFC6040, Section 4.2:

Default Tunnel Egress Behaviour.
 o If the inner ECN field is Not-ECT, the decapsulator MUST NOT
      propagate any other ECN codepoint onwards.  This is because the
      inner Not-ECT marking is set by transports that rely on dropped
      packets as an indication of congestion and would not understand or
      respond to any other ECN codepoint [RFC4774].  Specifically:

      *  If the inner ECN field is Not-ECT and the outer ECN field is
         CE, the decapsulator MUST drop the packet.

      *  If the inner ECN field is Not-ECT and the outer ECN field is
         Not-ECT, ECT(0), or ECT(1), the decapsulator MUST forward the
         outgoing packet with the ECN field cleared to Not-ECT.

The patch takes benefits from common function added in net/inet_ecn.h.

Like it was done for Xin4 tunnels, it adds logging to allow detecting broken
systems that set ECN bits incorrectly when tunneling (or an intermediate
router might be changing the header). Errors are also tracked via
rx_frame_error.

CC: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-28 11:37:11 -05:00

1844 lines
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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
#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/if_tunnel.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 <asm/uaccess.h>
#include <linux/atomic.h>
#include <net/icmp.h>
#include <net/ip.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>
MODULE_AUTHOR("Ville Nuorvala");
MODULE_DESCRIPTION("IPv6 tunneling device");
MODULE_LICENSE("GPL");
MODULE_ALIAS_NETDEV("ip6tnl0");
#ifdef IP6_TNL_DEBUG
#define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__)
#else
#define IP6_TNL_TRACE(x...) do {;} while(0)
#endif
#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
#define IPV6_TCLASS_SHIFT 20
#define HASH_SIZE_SHIFT 5
#define HASH_SIZE (1 << 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, 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 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[HASH_SIZE];
struct ip6_tnl __rcu *tnls_wc[1];
struct ip6_tnl __rcu **tnls[2];
};
static struct net_device_stats *ip6_get_stats(struct net_device *dev)
{
struct pcpu_tstats sum = { 0 };
int i;
for_each_possible_cpu(i) {
const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
sum.rx_packets += tstats->rx_packets;
sum.rx_bytes += tstats->rx_bytes;
sum.tx_packets += tstats->tx_packets;
sum.tx_bytes += tstats->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;
}
/*
* Locking : hash tables are protected by RCU and RTNL
*/
struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
{
struct dst_entry *dst = t->dst_cache;
if (dst && dst->obsolete &&
dst->ops->check(dst, t->dst_cookie) == NULL) {
t->dst_cache = NULL;
dst_release(dst);
return NULL;
}
return dst;
}
EXPORT_SYMBOL_GPL(ip6_tnl_dst_check);
void ip6_tnl_dst_reset(struct ip6_tnl *t)
{
dst_release(t->dst_cache);
t->dst_cache = NULL;
}
EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset);
void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
{
struct rt6_info *rt = (struct rt6_info *) dst;
t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
dst_release(t->dst_cache);
t->dst_cache = dst;
}
EXPORT_SYMBOL_GPL(ip6_tnl_dst_store);
/**
* 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);
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;
}
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);
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;
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)
{
free_percpu(dev->tstats);
free_netdev(dev);
}
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);
err = ip6_tnl_dev_init(dev);
if (err < 0)
goto out;
err = register_netdevice(dev);
if (err < 0)
goto out;
strcpy(t->parms.name, dev->name);
dev->rtnl_link_ops = &ip6_link_ops;
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 NULL
**/
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;
if (p->name[0])
strlcpy(name, p->name, IFNAMSIZ);
else
sprintf(name, "ip6tnl%%d");
dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup);
if (dev == NULL)
goto failed;
dev_net_set(dev, net);
t = netdev_priv(dev);
t->parms = *p;
err = ip6_tnl_create2(dev);
if (err < 0)
goto failed_free;
return t;
failed_free:
ip6_dev_free(dev);
failed:
return NULL;
}
/**
* 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 NULL
**/
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))
return t;
}
if (!create)
return NULL;
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 = dev_net(dev);
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);
ip6_tnl_dst_reset(t);
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 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
{
const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
__u8 nexthdr = ipv6h->nexthdr;
__u16 off = sizeof (*ipv6h);
while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
__u16 optlen = 0;
struct ipv6_opt_hdr *hdr;
if (raw + off + sizeof (*hdr) > skb->data &&
!pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
break;
hdr = (struct ipv6_opt_hdr *) (raw + 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);
}
if (nexthdr == NEXTHDR_DEST) {
__u16 i = off + 2;
while (1) {
struct ipv6_tlv_tnl_enc_lim *tel;
/* No more room for encapsulation limit */
if (i + sizeof (*tel) > off + optlen)
break;
tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
/* return index of option if found and valid */
if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
tel->length == 1)
return i;
/* else jump to next option */
if (tel->type)
i += tel->length + 2;
else
i++;
}
}
nexthdr = hdr->nexthdr;
off += optlen;
}
return 0;
}
EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
/**
* ip6_tnl_err - tunnel error handler
*
* Description:
* 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 ip6_tnl *t;
int rel_msg = 0;
u8 rel_type = ICMPV6_DEST_UNREACH;
u8 rel_code = ICMPV6_ADDR_UNREACH;
__u32 rel_info = 0;
__u16 len;
int err = -ENOENT;
/* 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();
if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
&ipv6h->saddr)) == NULL)
goto out;
if (t->parms.proto != ipproto && t->parms.proto != 0)
goto out;
err = 0;
switch (*type) {
__u32 teli;
struct ipv6_tlv_tnl_enc_lim *tel;
__u32 mtu;
case ICMPV6_DEST_UNREACH:
net_warn_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_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
t->parms.name);
rel_msg = 1;
}
break;
case ICMPV6_PARAMPROB:
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_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
t->parms.name);
rel_msg = 1;
}
} else {
net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
t->parms.name);
}
break;
case ICMPV6_PKT_TOOBIG:
mtu = *info - offset;
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
t->dev->mtu = mtu;
if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
rel_type = ICMPV6_PKT_TOOBIG;
rel_code = 0;
rel_info = mtu;
rel_msg = 1;
}
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)
{
int rel_msg = 0;
u8 rel_type = type;
u8 rel_code = code;
__u32 rel_info = ntohl(info);
int err;
struct sk_buff *skb2;
const struct iphdr *eiph;
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;
case NDISC_REDIRECT:
rel_type = ICMP_REDIRECT;
rel_code = ICMP_REDIR_HOST;
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;
/* route "incoming" packet */
if (rt->rt_flags & RTCF_LOCAL) {
ip_rt_put(rt);
rt = NULL;
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_TUNNEL) {
if (!IS_ERR(rt))
ip_rt_put(rt);
goto out;
}
skb_dst_set(skb2, &rt->dst);
} else {
ip_rt_put(rt);
if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
skb2->dev) ||
skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
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(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
}
if (rel_type == ICMP_REDIRECT)
skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
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)
{
int rel_msg = 0;
u8 rel_type = type;
u8 rel_code = code;
__u32 rel_info = ntohl(info);
int err;
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, 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 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 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 = dev_net(t->dev);
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(net, laddr, ldev, 0))) &&
likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
ret = 1;
}
return ret;
}
EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
/**
* ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
* @skb: received socket buffer
* @protocol: ethernet protocol ID
* @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
*
* Return: 0
**/
static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
__u8 ipproto,
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);
int err;
rcu_read_lock();
if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
&ipv6h->daddr)) != NULL) {
struct pcpu_tstats *tstats;
if (t->parms.proto != ipproto && t->parms.proto != 0) {
rcu_read_unlock();
goto discard;
}
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
rcu_read_unlock();
goto discard;
}
if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
t->dev->stats.rx_dropped++;
rcu_read_unlock();
goto discard;
}
secpath_reset(skb);
skb->mac_header = skb->network_header;
skb_reset_network_header(skb);
skb->protocol = htons(protocol);
skb->pkt_type = PACKET_HOST;
memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
__skb_tunnel_rx(skb, t->dev);
err = dscp_ecn_decapsulate(t, ipv6h, skb);
if (unlikely(err)) {
if (log_ecn_error)
net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
&ipv6h->saddr,
ipv6_get_dsfield(ipv6h));
if (err > 1) {
++t->dev->stats.rx_frame_errors;
++t->dev->stats.rx_errors;
rcu_read_unlock();
goto discard;
}
}
tstats = this_cpu_ptr(t->dev->tstats);
tstats->rx_packets++;
tstats->rx_bytes += skb->len;
netif_rx(skb);
rcu_read_unlock();
return 0;
}
rcu_read_unlock();
return 1;
discard:
kfree_skb(skb);
return 0;
}
static int ip4ip6_rcv(struct sk_buff *skb)
{
return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
ip4ip6_dscp_ecn_decapsulate);
}
static int ip6ip6_rcv(struct sk_buff *skb)
{
return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
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.dst0opt = (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 ip6_tnl_xmit_ctl(struct ip6_tnl *t)
{
struct __ip6_tnl_parm *p = &t->parms;
int ret = 0;
struct net *net = dev_net(t->dev);
if (p->flags & 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, &p->laddr, ldev, 0)))
pr_warn("%s xmit: Local address not yet configured!\n",
p->name);
else if (!ipv6_addr_is_multicast(&p->raddr) &&
unlikely(ipv6_chk_addr(net, &p->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;
}
EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
/**
* ip6_tnl_xmit2 - encapsulate packet and send
* @skb: the outgoing socket buffer
* @dev: the outgoing tunnel device
* @dsfield: dscp code for outer header
* @fl: flow of tunneled packet
* @encap_limit: encapsulation limit
* @pmtu: Path MTU is stored if packet is too big
*
* 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.
**/
static int ip6_tnl_xmit2(struct sk_buff *skb,
struct net_device *dev,
__u8 dsfield,
struct flowi6 *fl6,
int encap_limit,
__u32 *pmtu)
{
struct net *net = dev_net(dev);
struct ip6_tnl *t = netdev_priv(dev);
struct net_device_stats *stats = &t->dev->stats;
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
struct ipv6_tel_txoption opt;
struct dst_entry *dst = NULL, *ndst = NULL;
struct net_device *tdev;
int mtu;
unsigned int max_headroom = sizeof(struct ipv6hdr);
u8 proto;
int err = -1;
int pkt_len;
if (!fl6->flowi6_mark)
dst = ip6_tnl_dst_check(t);
if (!dst) {
ndst = ip6_route_output(net, NULL, fl6);
if (ndst->error)
goto tx_err_link_failure;
ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
if (IS_ERR(ndst)) {
err = PTR_ERR(ndst);
ndst = NULL;
goto tx_err_link_failure;
}
dst = ndst;
}
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) - sizeof (*ipv6h);
if (encap_limit >= 0) {
max_headroom += 8;
mtu -= 8;
}
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
if (skb_dst(skb))
skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
if (skb->len > mtu) {
*pmtu = mtu;
err = -EMSGSIZE;
goto tx_err_dst_release;
}
/*
* Okay, now see if we can stuff it in the buffer as-is.
*/
max_headroom += LL_RESERVED_SPACE(tdev);
if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
(skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
struct sk_buff *new_skb;
if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
goto tx_err_dst_release;
if (skb->sk)
skb_set_owner_w(new_skb, skb->sk);
consume_skb(skb);
skb = new_skb;
}
skb_dst_drop(skb);
if (fl6->flowi6_mark) {
skb_dst_set(skb, dst);
ndst = NULL;
} else {
skb_dst_set_noref(skb, dst);
}
skb->transport_header = skb->network_header;
proto = fl6->flowi6_proto;
if (encap_limit >= 0) {
init_tel_txopt(&opt, encap_limit);
ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
}
skb_push(skb, sizeof(struct ipv6hdr));
skb_reset_network_header(skb);
ipv6h = ipv6_hdr(skb);
*(__be32*)ipv6h = fl6->flowlabel | htonl(0x60000000);
dsfield = INET_ECN_encapsulate(0, dsfield);
ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
ipv6h->hop_limit = t->parms.hop_limit;
ipv6h->nexthdr = proto;
ipv6h->saddr = fl6->saddr;
ipv6h->daddr = fl6->daddr;
nf_reset(skb);
pkt_len = skb->len;
err = ip6_local_out(skb);
if (net_xmit_eval(err) == 0) {
struct pcpu_tstats *tstats = this_cpu_ptr(t->dev->tstats);
tstats->tx_bytes += pkt_len;
tstats->tx_packets++;
} else {
stats->tx_errors++;
stats->tx_aborted_errors++;
}
if (ndst)
ip6_tnl_dst_store(t, ndst);
return 0;
tx_err_link_failure:
stats->tx_carrier_errors++;
dst_link_failure(skb);
tx_err_dst_release:
dst_release(ndst);
return err;
}
static inline int
ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
const struct iphdr *iph = ip_hdr(skb);
int encap_limit = -1;
struct flowi6 fl6;
__u8 dsfield;
__u32 mtu;
int err;
if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
!ip6_tnl_xmit_ctl(t))
return -1;
if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
encap_limit = t->parms.encap_limit;
memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
fl6.flowi6_proto = IPPROTO_IPIP;
dsfield = ipv4_get_dsfield(iph);
if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
& IPV6_TCLASS_MASK;
if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
fl6.flowi6_mark = skb->mark;
err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
if (err != 0) {
/* XXX: send ICMP error even if DF is not set. */
if (err == -EMSGSIZE)
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
htonl(mtu));
return -1;
}
return 0;
}
static inline int
ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
int encap_limit = -1;
__u16 offset;
struct flowi6 fl6;
__u8 dsfield;
__u32 mtu;
int err;
if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
!ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
return -1;
offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
if (offset > 0) {
struct ipv6_tlv_tnl_enc_lim *tel;
tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
if (tel->encap_limit == 0) {
icmpv6_send(skb, ICMPV6_PARAMPROB,
ICMPV6_HDR_FIELD, offset + 2);
return -1;
}
encap_limit = tel->encap_limit - 1;
} else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
encap_limit = t->parms.encap_limit;
memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
fl6.flowi6_proto = IPPROTO_IPV6;
dsfield = ipv6_get_dsfield(ipv6h);
if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
fl6.flowi6_mark = skb->mark;
err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
if (err != 0) {
if (err == -EMSGSIZE)
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
return -1;
}
return 0;
}
static netdev_tx_t
ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
struct net_device_stats *stats = &t->dev->stats;
int ret;
switch (skb->protocol) {
case htons(ETH_P_IP):
ret = ip4ip6_tnl_xmit(skb, dev);
break;
case htons(ETH_P_IPV6):
ret = ip6ip6_tnl_xmit(skb, dev);
break;
default:
goto tx_err;
}
if (ret < 0)
goto tx_err;
return NETDEV_TX_OK;
tx_err:
stats->tx_errors++;
stats->tx_dropped++;
kfree_skb(skb);
return NETDEV_TX_OK;
}
static void ip6_tnl_link_config(struct ip6_tnl *t)
{
struct net_device *dev = t->dev;
struct __ip6_tnl_parm *p = &t->parms;
struct flowi6 *fl6 = &t->fl.u.ip6;
memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
/* Set up flowi template */
fl6->saddr = p->laddr;
fl6->daddr = p->raddr;
fl6->flowi6_oif = p->link;
fl6->flowlabel = 0;
if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
dev->flags |= IFF_POINTOPOINT;
else
dev->flags &= ~IFF_POINTOPOINT;
dev->iflink = p->link;
if (p->flags & IP6_TNL_F_CAP_XMIT) {
int strict = (ipv6_addr_type(&p->raddr) &
(IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
struct rt6_info *rt = rt6_lookup(dev_net(dev),
&p->raddr, &p->laddr,
p->link, strict);
if (rt == NULL)
return;
if (rt->dst.dev) {
dev->hard_header_len = rt->dst.dev->hard_header_len +
sizeof (struct ipv6hdr);
dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr);
if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
dev->mtu-=8;
if (dev->mtu < IPV6_MIN_MTU)
dev->mtu = IPV6_MIN_MTU;
}
ip6_rt_put(rt);
}
}
/**
* ip6_tnl_change - update the tunnel parameters
* @t: tunnel to be changed
* @p: tunnel configuration parameters
*
* Description:
* ip6_tnl_change() updates the tunnel parameters
**/
static int
ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
{
t->parms.laddr = p->laddr;
t->parms.raddr = p->raddr;
t->parms.flags = p->flags;
t->parms.hop_limit = p->hop_limit;
t->parms.encap_limit = p->encap_limit;
t->parms.flowinfo = p->flowinfo;
t->parms.link = p->link;
t->parms.proto = p->proto;
ip6_tnl_dst_reset(t);
ip6_tnl_link_config(t);
return 0;
}
static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
{
struct net *net = dev_net(t->dev);
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
int err;
ip6_tnl_unlink(ip6n, t);
synchronize_net();
err = ip6_tnl_change(t, p);
ip6_tnl_link(ip6n, t);
netdev_state_change(t->dev);
return err;
}
static void
ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
{
p->laddr = u->laddr;
p->raddr = u->raddr;
p->flags = u->flags;
p->hop_limit = u->hop_limit;
p->encap_limit = u->encap_limit;
p->flowinfo = u->flowinfo;
p->link = u->link;
p->proto = u->proto;
memcpy(p->name, u->name, sizeof(u->name));
}
static void
ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
{
u->laddr = p->laddr;
u->raddr = p->raddr;
u->flags = p->flags;
u->hop_limit = p->hop_limit;
u->encap_limit = p->encap_limit;
u->flowinfo = p->flowinfo;
u->link = p->link;
u->proto = p->proto;
memcpy(u->name, p->name, sizeof(u->name));
}
/**
* ip6_tnl_ioctl - configure ipv6 tunnels from userspace
* @dev: virtual device associated with tunnel
* @ifr: parameters passed from userspace
* @cmd: command to be performed
*
* Description:
* ip6_tnl_ioctl() is used for managing IPv6 tunnels
* from userspace.
*
* The possible commands are the following:
* %SIOCGETTUNNEL: get tunnel parameters for device
* %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
* %SIOCCHGTUNNEL: change tunnel parameters to those given
* %SIOCDELTUNNEL: delete tunnel
*
* The fallback device "ip6tnl0", created during module
* initialization, can be used for creating other tunnel devices.
*
* Return:
* 0 on success,
* %-EFAULT if unable to copy data to or from userspace,
* %-EPERM if current process hasn't %CAP_NET_ADMIN set
* %-EINVAL if passed tunnel parameters are invalid,
* %-EEXIST if changing a tunnel's parameters would cause a conflict
* %-ENODEV if attempting to change or delete a nonexisting device
**/
static int
ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
int err = 0;
struct ip6_tnl_parm p;
struct __ip6_tnl_parm p1;
struct ip6_tnl *t = NULL;
struct net *net = dev_net(dev);
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
switch (cmd) {
case SIOCGETTUNNEL:
if (dev == ip6n->fb_tnl_dev) {
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
err = -EFAULT;
break;
}
ip6_tnl_parm_from_user(&p1, &p);
t = ip6_tnl_locate(net, &p1, 0);
} else {
memset(&p, 0, sizeof(p));
}
if (t == NULL)
t = netdev_priv(dev);
ip6_tnl_parm_to_user(&p, &t->parms);
if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
err = -EFAULT;
}
break;
case SIOCADDTUNNEL:
case SIOCCHGTUNNEL:
err = -EPERM;
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
break;
err = -EFAULT;
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
break;
err = -EINVAL;
if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
p.proto != 0)
break;
ip6_tnl_parm_from_user(&p1, &p);
t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
if (t != NULL) {
if (t->dev != dev) {
err = -EEXIST;
break;
}
} else
t = netdev_priv(dev);
err = ip6_tnl_update(t, &p1);
}
if (t) {
err = 0;
ip6_tnl_parm_to_user(&p, &t->parms);
if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
err = -EFAULT;
} else
err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
break;
case SIOCDELTUNNEL:
err = -EPERM;
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
break;
if (dev == ip6n->fb_tnl_dev) {
err = -EFAULT;
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
break;
err = -ENOENT;
ip6_tnl_parm_from_user(&p1, &p);
t = ip6_tnl_locate(net, &p1, 0);
if (t == NULL)
break;
err = -EPERM;
if (t->dev == ip6n->fb_tnl_dev)
break;
dev = t->dev;
}
err = 0;
unregister_netdevice(dev);
break;
default:
err = -EINVAL;
}
return err;
}
/**
* ip6_tnl_change_mtu - change mtu manually for tunnel device
* @dev: virtual device associated with tunnel
* @new_mtu: the new mtu
*
* Return:
* 0 on success,
* %-EINVAL if mtu too small
**/
static int
ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
{
if (new_mtu < IPV6_MIN_MTU) {
return -EINVAL;
}
dev->mtu = new_mtu;
return 0;
}
static const struct net_device_ops ip6_tnl_netdev_ops = {
.ndo_uninit = ip6_tnl_dev_uninit,
.ndo_start_xmit = ip6_tnl_xmit,
.ndo_do_ioctl = ip6_tnl_ioctl,
.ndo_change_mtu = ip6_tnl_change_mtu,
.ndo_get_stats = ip6_get_stats,
};
/**
* ip6_tnl_dev_setup - setup virtual tunnel device
* @dev: virtual device associated with tunnel
*
* Description:
* Initialize function pointers and device parameters
**/
static void ip6_tnl_dev_setup(struct net_device *dev)
{
struct ip6_tnl *t;
dev->netdev_ops = &ip6_tnl_netdev_ops;
dev->destructor = ip6_dev_free;
dev->type = ARPHRD_TUNNEL6;
dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
t = netdev_priv(dev);
if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
dev->mtu-=8;
dev->flags |= IFF_NOARP;
dev->addr_len = sizeof(struct in6_addr);
dev->features |= NETIF_F_NETNS_LOCAL;
dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
}
/**
* ip6_tnl_dev_init_gen - general initializer for all tunnel devices
* @dev: virtual device associated with tunnel
**/
static inline int
ip6_tnl_dev_init_gen(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
t->dev = dev;
dev->tstats = alloc_percpu(struct pcpu_tstats);
if (!dev->tstats)
return -ENOMEM;
return 0;
}
/**
* ip6_tnl_dev_init - initializer for all non fallback tunnel devices
* @dev: virtual device associated with tunnel
**/
static int ip6_tnl_dev_init(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
int err = ip6_tnl_dev_init_gen(dev);
if (err)
return err;
ip6_tnl_link_config(t);
return 0;
}
/**
* ip6_fb_tnl_dev_init - initializer for fallback tunnel device
* @dev: fallback device
*
* Return: 0
**/
static int __net_init ip6_fb_tnl_dev_init(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 = ip6_tnl_dev_init_gen(dev);
if (err)
return err;
t->parms.proto = IPPROTO_IPV6;
dev_hold(dev);
ip6_tnl_link_config(t);
rcu_assign_pointer(ip6n->tnls_wc[0], t);
return 0;
}
static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
{
u8 proto;
if (!data)
return 0;
proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
if (proto != IPPROTO_IPV6 &&
proto != IPPROTO_IPIP &&
proto != 0)
return -EINVAL;
return 0;
}
static void ip6_tnl_netlink_parms(struct nlattr *data[],
struct __ip6_tnl_parm *parms)
{
memset(parms, 0, sizeof(*parms));
if (!data)
return;
if (data[IFLA_IPTUN_LINK])
parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
if (data[IFLA_IPTUN_LOCAL])
nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL],
sizeof(struct in6_addr));
if (data[IFLA_IPTUN_REMOTE])
nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE],
sizeof(struct in6_addr));
if (data[IFLA_IPTUN_TTL])
parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
if (data[IFLA_IPTUN_ENCAP_LIMIT])
parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
if (data[IFLA_IPTUN_FLOWINFO])
parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
if (data[IFLA_IPTUN_FLAGS])
parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
if (data[IFLA_IPTUN_PROTO])
parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
}
static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct net *net = dev_net(dev);
struct ip6_tnl *nt;
nt = netdev_priv(dev);
ip6_tnl_netlink_parms(data, &nt->parms);
if (ip6_tnl_locate(net, &nt->parms, 0))
return -EEXIST;
return ip6_tnl_create2(dev);
}
static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
struct nlattr *data[])
{
struct ip6_tnl *t;
struct __ip6_tnl_parm p;
struct net *net = dev_net(dev);
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
if (dev == ip6n->fb_tnl_dev)
return -EINVAL;
ip6_tnl_netlink_parms(data, &p);
t = ip6_tnl_locate(net, &p, 0);
if (t) {
if (t->dev != dev)
return -EEXIST;
} else
t = netdev_priv(dev);
return ip6_tnl_update(t, &p);
}
static size_t ip6_tnl_get_size(const struct net_device *dev)
{
return
/* IFLA_IPTUN_LINK */
nla_total_size(4) +
/* IFLA_IPTUN_LOCAL */
nla_total_size(sizeof(struct in6_addr)) +
/* IFLA_IPTUN_REMOTE */
nla_total_size(sizeof(struct in6_addr)) +
/* IFLA_IPTUN_TTL */
nla_total_size(1) +
/* IFLA_IPTUN_ENCAP_LIMIT */
nla_total_size(1) +
/* IFLA_IPTUN_FLOWINFO */
nla_total_size(4) +
/* IFLA_IPTUN_FLAGS */
nla_total_size(4) +
/* IFLA_IPTUN_PROTO */
nla_total_size(1) +
0;
}
static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct ip6_tnl *tunnel = netdev_priv(dev);
struct __ip6_tnl_parm *parm = &tunnel->parms;
if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
&parm->raddr) ||
nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr),
&parm->laddr) ||
nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
[IFLA_IPTUN_LINK] = { .type = NLA_U32 },
[IFLA_IPTUN_LOCAL] = { .len = sizeof(struct in6_addr) },
[IFLA_IPTUN_REMOTE] = { .len = sizeof(struct in6_addr) },
[IFLA_IPTUN_TTL] = { .type = NLA_U8 },
[IFLA_IPTUN_ENCAP_LIMIT] = { .type = NLA_U8 },
[IFLA_IPTUN_FLOWINFO] = { .type = NLA_U32 },
[IFLA_IPTUN_FLAGS] = { .type = NLA_U32 },
[IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
};
static struct rtnl_link_ops ip6_link_ops __read_mostly = {
.kind = "ip6tnl",
.maxtype = IFLA_IPTUN_MAX,
.policy = ip6_tnl_policy,
.priv_size = sizeof(struct ip6_tnl),
.setup = ip6_tnl_dev_setup,
.validate = ip6_tnl_validate,
.newlink = ip6_tnl_newlink,
.changelink = ip6_tnl_changelink,
.get_size = ip6_tnl_get_size,
.fill_info = ip6_tnl_fill_info,
};
static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
.handler = ip4ip6_rcv,
.err_handler = ip4ip6_err,
.priority = 1,
};
static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
.handler = ip6ip6_rcv,
.err_handler = ip6ip6_err,
.priority = 1,
};
static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n)
{
int h;
struct ip6_tnl *t;
LIST_HEAD(list);
for (h = 0; h < HASH_SIZE; h++) {
t = rtnl_dereference(ip6n->tnls_r_l[h]);
while (t != NULL) {
unregister_netdevice_queue(t->dev, &list);
t = rtnl_dereference(t->next);
}
}
t = rtnl_dereference(ip6n->tnls_wc[0]);
unregister_netdevice_queue(t->dev, &list);
unregister_netdevice_many(&list);
}
static int __net_init ip6_tnl_init_net(struct net *net)
{
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
struct ip6_tnl *t = NULL;
int err;
ip6n->tnls[0] = ip6n->tnls_wc;
ip6n->tnls[1] = ip6n->tnls_r_l;
err = -ENOMEM;
ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
ip6_tnl_dev_setup);
if (!ip6n->fb_tnl_dev)
goto err_alloc_dev;
dev_net_set(ip6n->fb_tnl_dev, net);
err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
if (err < 0)
goto err_register;
err = register_netdev(ip6n->fb_tnl_dev);
if (err < 0)
goto err_register;
t = netdev_priv(ip6n->fb_tnl_dev);
strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
return 0;
err_register:
ip6_dev_free(ip6n->fb_tnl_dev);
err_alloc_dev:
return err;
}
static void __net_exit ip6_tnl_exit_net(struct net *net)
{
struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
rtnl_lock();
ip6_tnl_destroy_tunnels(ip6n);
rtnl_unlock();
}
static struct pernet_operations ip6_tnl_net_ops = {
.init = ip6_tnl_init_net,
.exit = ip6_tnl_exit_net,
.id = &ip6_tnl_net_id,
.size = sizeof(struct ip6_tnl_net),
};
/**
* ip6_tunnel_init - register protocol and reserve needed resources
*
* Return: 0 on success
**/
static int __init ip6_tunnel_init(void)
{
int err;
err = register_pernet_device(&ip6_tnl_net_ops);
if (err < 0)
goto out_pernet;
err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
if (err < 0) {
pr_err("%s: can't register ip4ip6\n", __func__);
goto out_ip4ip6;
}
err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
if (err < 0) {
pr_err("%s: can't register ip6ip6\n", __func__);
goto out_ip6ip6;
}
err = rtnl_link_register(&ip6_link_ops);
if (err < 0)
goto rtnl_link_failed;
return 0;
rtnl_link_failed:
xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
out_ip6ip6:
xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
out_ip4ip6:
unregister_pernet_device(&ip6_tnl_net_ops);
out_pernet:
return err;
}
/**
* ip6_tunnel_cleanup - free resources and unregister protocol
**/
static void __exit ip6_tunnel_cleanup(void)
{
rtnl_link_unregister(&ip6_link_ops);
if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
pr_info("%s: can't deregister ip4ip6\n", __func__);
if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
pr_info("%s: can't deregister ip6ip6\n", __func__);
unregister_pernet_device(&ip6_tnl_net_ops);
}
module_init(ip6_tunnel_init);
module_exit(ip6_tunnel_cleanup);
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