linux/net/ipv6/sit.c
Alexander Lobakin 5832c4a77d ip_tunnel: convert __be16 tunnel flags to bitmaps
Historically, tunnel flags like TUNNEL_CSUM or TUNNEL_ERSPAN_OPT
have been defined as __be16. Now all of those 16 bits are occupied
and there's no more free space for new flags.
It can't be simply switched to a bigger container with no
adjustments to the values, since it's an explicit Endian storage,
and on LE systems (__be16)0x0001 equals to
(__be64)0x0001000000000000.
We could probably define new 64-bit flags depending on the
Endianness, i.e. (__be64)0x0001 on BE and (__be64)0x00010000... on
LE, but that would introduce an Endianness dependency and spawn a
ton of Sparse warnings. To mitigate them, all of those places which
were adjusted with this change would be touched anyway, so why not
define stuff properly if there's no choice.

Define IP_TUNNEL_*_BIT counterparts as a bit number instead of the
value already coded and a fistful of <16 <-> bitmap> converters and
helpers. The two flags which have a different bit position are
SIT_ISATAP_BIT and VTI_ISVTI_BIT, as they were defined not as
__cpu_to_be16(), but as (__force __be16), i.e. had different
positions on LE and BE. Now they both have strongly defined places.
Change all __be16 fields which were used to store those flags, to
IP_TUNNEL_DECLARE_FLAGS() -> DECLARE_BITMAP(__IP_TUNNEL_FLAG_NUM) ->
unsigned long[1] for now, and replace all TUNNEL_* occurrences to
their bitmap counterparts. Use the converters in the places which talk
to the userspace, hardware (NFP) or other hosts (GRE header). The rest
must explicitly use the new flags only. This must be done at once,
otherwise there will be too many conversions throughout the code in
the intermediate commits.
Finally, disable the old __be16 flags for use in the kernel code
(except for the two 'irregular' flags mentioned above), to prevent
any accidental (mis)use of them. For the userspace, nothing is
changed, only additions were made.

Most noticeable bloat-o-meter difference (.text):

vmlinux:	307/-1 (306)
gre.ko:		62/0 (62)
ip_gre.ko:	941/-217 (724)	[*]
ip_tunnel.ko:	390/-900 (-510)	[**]
ip_vti.ko:	138/0 (138)
ip6_gre.ko:	534/-18 (516)	[*]
ip6_tunnel.ko:	118/-10 (108)

[*] gre_flags_to_tnl_flags() grew, but still is inlined
[**] ip_tunnel_find() got uninlined, hence such decrease

The average code size increase in non-extreme case is 100-200 bytes
per module, mostly due to sizeof(long) > sizeof(__be16), as
%__IP_TUNNEL_FLAG_NUM is less than %BITS_PER_LONG and the compilers
are able to expand the majority of bitmap_*() calls here into direct
operations on scalars.

Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-01 10:49:28 +01:00

1960 lines
46 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
* Linux INET6 implementation
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
*
* Changes:
* Roger Venning <r.venning@telstra.com>: 6to4 support
* Nate Thompson <nate@thebog.net>: 6to4 support
* Fred Templin <fred.l.templin@boeing.com>: isatap support
*/
#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/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/icmp.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/init.h>
#include <linux/netfilter_ipv4.h>
#include <linux/if_ether.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/ip.h>
#include <net/udp.h>
#include <net/icmp.h>
#include <net/ip_tunnels.h>
#include <net/inet_ecn.h>
#include <net/xfrm.h>
#include <net/dsfield.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
/*
This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
For comments look at net/ipv4/ip_gre.c --ANK
*/
#define IP6_SIT_HASH_SIZE 16
#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
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 int ipip6_tunnel_init(struct net_device *dev);
static void ipip6_tunnel_setup(struct net_device *dev);
static void ipip6_dev_free(struct net_device *dev);
static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
__be32 *v4dst);
static struct rtnl_link_ops sit_link_ops __read_mostly;
static unsigned int sit_net_id __read_mostly;
struct sit_net {
struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
struct ip_tunnel __rcu *tunnels_wc[1];
struct ip_tunnel __rcu **tunnels[4];
struct net_device *fb_tunnel_dev;
};
static inline struct sit_net *dev_to_sit_net(struct net_device *dev)
{
struct ip_tunnel *t = netdev_priv(dev);
return net_generic(t->net, sit_net_id);
}
/*
* Must be invoked with rcu_read_lock
*/
static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
struct net_device *dev,
__be32 remote, __be32 local,
int sifindex)
{
unsigned int h0 = HASH(remote);
unsigned int h1 = HASH(local);
struct ip_tunnel *t;
struct sit_net *sitn = net_generic(net, sit_net_id);
int ifindex = dev ? dev->ifindex : 0;
for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
if (local == t->parms.iph.saddr &&
remote == t->parms.iph.daddr &&
(!dev || !t->parms.link || ifindex == t->parms.link ||
sifindex == t->parms.link) &&
(t->dev->flags & IFF_UP))
return t;
}
for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
if (remote == t->parms.iph.daddr &&
(!dev || !t->parms.link || ifindex == t->parms.link ||
sifindex == t->parms.link) &&
(t->dev->flags & IFF_UP))
return t;
}
for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
if (local == t->parms.iph.saddr &&
(!dev || !t->parms.link || ifindex == t->parms.link ||
sifindex == t->parms.link) &&
(t->dev->flags & IFF_UP))
return t;
}
t = rcu_dereference(sitn->tunnels_wc[0]);
if (t && (t->dev->flags & IFF_UP))
return t;
return NULL;
}
static struct ip_tunnel __rcu **
__ipip6_bucket(struct sit_net *sitn, struct ip_tunnel_parm_kern *parms)
{
__be32 remote = parms->iph.daddr;
__be32 local = parms->iph.saddr;
unsigned int h = 0;
int prio = 0;
if (remote) {
prio |= 2;
h ^= HASH(remote);
}
if (local) {
prio |= 1;
h ^= HASH(local);
}
return &sitn->tunnels[prio][h];
}
static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
struct ip_tunnel *t)
{
return __ipip6_bucket(sitn, &t->parms);
}
static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
{
struct ip_tunnel __rcu **tp;
struct ip_tunnel *iter;
for (tp = ipip6_bucket(sitn, t);
(iter = rtnl_dereference(*tp)) != NULL;
tp = &iter->next) {
if (t == iter) {
rcu_assign_pointer(*tp, t->next);
break;
}
}
}
static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
{
struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
rcu_assign_pointer(t->next, rtnl_dereference(*tp));
rcu_assign_pointer(*tp, t);
}
static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
{
#ifdef CONFIG_IPV6_SIT_6RD
struct ip_tunnel *t = netdev_priv(dev);
if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
t->ip6rd.relay_prefix = 0;
t->ip6rd.prefixlen = 16;
t->ip6rd.relay_prefixlen = 0;
} else {
struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
}
#endif
}
static int ipip6_tunnel_create(struct net_device *dev)
{
struct ip_tunnel *t = netdev_priv(dev);
struct net *net = dev_net(dev);
struct sit_net *sitn = net_generic(net, sit_net_id);
int err;
__dev_addr_set(dev, &t->parms.iph.saddr, 4);
memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
if (test_bit(IP_TUNNEL_SIT_ISATAP_BIT, t->parms.i_flags))
dev->priv_flags |= IFF_ISATAP;
dev->rtnl_link_ops = &sit_link_ops;
err = register_netdevice(dev);
if (err < 0)
goto out;
ipip6_tunnel_clone_6rd(dev, sitn);
ipip6_tunnel_link(sitn, t);
return 0;
out:
return err;
}
static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
struct ip_tunnel_parm_kern *parms,
int create)
{
__be32 remote = parms->iph.daddr;
__be32 local = parms->iph.saddr;
struct ip_tunnel *t, *nt;
struct ip_tunnel __rcu **tp;
struct net_device *dev;
char name[IFNAMSIZ];
struct sit_net *sitn = net_generic(net, sit_net_id);
for (tp = __ipip6_bucket(sitn, parms);
(t = rtnl_dereference(*tp)) != NULL;
tp = &t->next) {
if (local == t->parms.iph.saddr &&
remote == t->parms.iph.daddr &&
parms->link == t->parms.link) {
if (create)
return NULL;
else
return t;
}
}
if (!create)
goto failed;
if (parms->name[0]) {
if (!dev_valid_name(parms->name))
goto failed;
strscpy(name, parms->name, IFNAMSIZ);
} else {
strcpy(name, "sit%d");
}
dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
ipip6_tunnel_setup);
if (!dev)
return NULL;
dev_net_set(dev, net);
nt = netdev_priv(dev);
nt->parms = *parms;
if (ipip6_tunnel_create(dev) < 0)
goto failed_free;
if (!parms->name[0])
strcpy(parms->name, dev->name);
return nt;
failed_free:
free_netdev(dev);
failed:
return NULL;
}
#define for_each_prl_rcu(start) \
for (prl = rcu_dereference(start); \
prl; \
prl = rcu_dereference(prl->next))
static struct ip_tunnel_prl_entry *
__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
{
struct ip_tunnel_prl_entry *prl;
for_each_prl_rcu(t->prl)
if (prl->addr == addr)
break;
return prl;
}
static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __user *a)
{
struct ip_tunnel *t = netdev_priv(dev);
struct ip_tunnel_prl kprl, *kp;
struct ip_tunnel_prl_entry *prl;
unsigned int cmax, c = 0, ca, len;
int ret = 0;
if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
return -EINVAL;
if (copy_from_user(&kprl, a, sizeof(kprl)))
return -EFAULT;
cmax = kprl.datalen / sizeof(kprl);
if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
cmax = 1;
/* For simple GET or for root users,
* we try harder to allocate.
*/
kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
kcalloc(cmax, sizeof(*kp), GFP_KERNEL_ACCOUNT | __GFP_NOWARN) :
NULL;
ca = min(t->prl_count, cmax);
if (!kp) {
/* We don't try hard to allocate much memory for
* non-root users.
* For root users, retry allocating enough memory for
* the answer.
*/
kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC | __GFP_ACCOUNT |
__GFP_NOWARN);
if (!kp) {
ret = -ENOMEM;
goto out;
}
}
rcu_read_lock();
for_each_prl_rcu(t->prl) {
if (c >= cmax)
break;
if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
continue;
kp[c].addr = prl->addr;
kp[c].flags = prl->flags;
c++;
if (kprl.addr != htonl(INADDR_ANY))
break;
}
rcu_read_unlock();
len = sizeof(*kp) * c;
ret = 0;
if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
ret = -EFAULT;
kfree(kp);
out:
return ret;
}
static int
ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
{
struct ip_tunnel_prl_entry *p;
int err = 0;
if (a->addr == htonl(INADDR_ANY))
return -EINVAL;
ASSERT_RTNL();
for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
if (p->addr == a->addr) {
if (chg) {
p->flags = a->flags;
goto out;
}
err = -EEXIST;
goto out;
}
}
if (chg) {
err = -ENXIO;
goto out;
}
p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
if (!p) {
err = -ENOBUFS;
goto out;
}
p->next = t->prl;
p->addr = a->addr;
p->flags = a->flags;
t->prl_count++;
rcu_assign_pointer(t->prl, p);
out:
return err;
}
static void prl_list_destroy_rcu(struct rcu_head *head)
{
struct ip_tunnel_prl_entry *p, *n;
p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
do {
n = rcu_dereference_protected(p->next, 1);
kfree(p);
p = n;
} while (p);
}
static int
ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
{
struct ip_tunnel_prl_entry *x;
struct ip_tunnel_prl_entry __rcu **p;
int err = 0;
ASSERT_RTNL();
if (a && a->addr != htonl(INADDR_ANY)) {
for (p = &t->prl;
(x = rtnl_dereference(*p)) != NULL;
p = &x->next) {
if (x->addr == a->addr) {
*p = x->next;
kfree_rcu(x, rcu_head);
t->prl_count--;
goto out;
}
}
err = -ENXIO;
} else {
x = rtnl_dereference(t->prl);
if (x) {
t->prl_count = 0;
call_rcu(&x->rcu_head, prl_list_destroy_rcu);
t->prl = NULL;
}
}
out:
return err;
}
static int ipip6_tunnel_prl_ctl(struct net_device *dev,
struct ip_tunnel_prl __user *data, int cmd)
{
struct ip_tunnel *t = netdev_priv(dev);
struct ip_tunnel_prl prl;
int err;
if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
return -EPERM;
if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
return -EINVAL;
if (copy_from_user(&prl, data, sizeof(prl)))
return -EFAULT;
switch (cmd) {
case SIOCDELPRL:
err = ipip6_tunnel_del_prl(t, &prl);
break;
case SIOCADDPRL:
case SIOCCHGPRL:
err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
break;
}
dst_cache_reset(&t->dst_cache);
netdev_state_change(dev);
return err;
}
static int
isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
{
struct ip_tunnel_prl_entry *p;
int ok = 1;
rcu_read_lock();
p = __ipip6_tunnel_locate_prl(t, iph->saddr);
if (p) {
if (p->flags & PRL_DEFAULT)
skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
else
skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
} else {
const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
if (ipv6_addr_is_isatap(addr6) &&
(addr6->s6_addr32[3] == iph->saddr) &&
ipv6_chk_prefix(addr6, t->dev))
skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
else
ok = 0;
}
rcu_read_unlock();
return ok;
}
static void ipip6_tunnel_uninit(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
if (dev == sitn->fb_tunnel_dev) {
RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
} else {
ipip6_tunnel_unlink(sitn, tunnel);
ipip6_tunnel_del_prl(tunnel, NULL);
}
dst_cache_reset(&tunnel->dst_cache);
netdev_put(dev, &tunnel->dev_tracker);
}
static int ipip6_err(struct sk_buff *skb, u32 info)
{
const struct iphdr *iph = (const struct iphdr *)skb->data;
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
unsigned int data_len = 0;
struct ip_tunnel *t;
int sifindex;
int err;
switch (type) {
default:
case ICMP_PARAMETERPROB:
return 0;
case ICMP_DEST_UNREACH:
switch (code) {
case ICMP_SR_FAILED:
/* Impossible event. */
return 0;
default:
/* All others are translated to HOST_UNREACH.
rfc2003 contains "deep thoughts" about NET_UNREACH,
I believe they are just ether pollution. --ANK
*/
break;
}
break;
case ICMP_TIME_EXCEEDED:
if (code != ICMP_EXC_TTL)
return 0;
data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
break;
case ICMP_REDIRECT:
break;
}
err = -ENOENT;
sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
iph->daddr, iph->saddr, sifindex);
if (!t)
goto out;
if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
ipv4_update_pmtu(skb, dev_net(skb->dev), info,
t->parms.link, iph->protocol);
err = 0;
goto out;
}
if (type == ICMP_REDIRECT) {
ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
iph->protocol);
err = 0;
goto out;
}
err = 0;
if (__in6_dev_get(skb->dev) &&
!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
goto out;
if (t->parms.iph.daddr == 0)
goto out;
if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
goto out;
if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
t->err_count++;
else
t->err_count = 1;
t->err_time = jiffies;
out:
return err;
}
static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
const struct in6_addr *v6addr)
{
__be32 v4embed = 0;
if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
return true;
return false;
}
/* Checks if an address matches an address on the tunnel interface.
* Used to detect the NAT of proto 41 packets and let them pass spoofing test.
* Long story:
* This function is called after we considered the packet as spoofed
* in is_spoofed_6rd.
* We may have a router that is doing NAT for proto 41 packets
* for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
* will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
* function will return true, dropping the packet.
* But, we can still check if is spoofed against the IP
* addresses associated with the interface.
*/
static bool only_dnatted(const struct ip_tunnel *tunnel,
const struct in6_addr *v6dst)
{
int prefix_len;
#ifdef CONFIG_IPV6_SIT_6RD
prefix_len = tunnel->ip6rd.prefixlen + 32
- tunnel->ip6rd.relay_prefixlen;
#else
prefix_len = 48;
#endif
return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
}
/* Returns true if a packet is spoofed */
static bool packet_is_spoofed(struct sk_buff *skb,
const struct iphdr *iph,
struct ip_tunnel *tunnel)
{
const struct ipv6hdr *ipv6h;
if (tunnel->dev->priv_flags & IFF_ISATAP) {
if (!isatap_chksrc(skb, iph, tunnel))
return true;
return false;
}
if (tunnel->dev->flags & IFF_POINTOPOINT)
return false;
ipv6h = ipv6_hdr(skb);
if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
&iph->saddr, &ipv6h->saddr,
&iph->daddr, &ipv6h->daddr);
return true;
}
if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
return false;
if (only_dnatted(tunnel, &ipv6h->daddr))
return false;
net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
&iph->saddr, &ipv6h->saddr,
&iph->daddr, &ipv6h->daddr);
return true;
}
static int ipip6_rcv(struct sk_buff *skb)
{
const struct iphdr *iph = ip_hdr(skb);
struct ip_tunnel *tunnel;
int sifindex;
int err;
sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
iph->saddr, iph->daddr, sifindex);
if (tunnel) {
if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
tunnel->parms.iph.protocol != 0)
goto out;
skb->mac_header = skb->network_header;
skb_reset_network_header(skb);
IPCB(skb)->flags = 0;
skb->dev = tunnel->dev;
if (packet_is_spoofed(skb, iph, tunnel)) {
DEV_STATS_INC(tunnel->dev, rx_errors);
goto out;
}
if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
!net_eq(tunnel->net, dev_net(tunnel->dev))))
goto out;
/* skb can be uncloned in iptunnel_pull_header, so
* old iph is no longer valid
*/
iph = (const struct iphdr *)skb_mac_header(skb);
skb_reset_mac_header(skb);
err = IP_ECN_decapsulate(iph, skb);
if (unlikely(err)) {
if (log_ecn_error)
net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
&iph->saddr, iph->tos);
if (err > 1) {
DEV_STATS_INC(tunnel->dev, rx_frame_errors);
DEV_STATS_INC(tunnel->dev, rx_errors);
goto out;
}
}
dev_sw_netstats_rx_add(tunnel->dev, skb->len);
netif_rx(skb);
return 0;
}
/* no tunnel matched, let upstream know, ipsec may handle it */
return 1;
out:
kfree_skb(skb);
return 0;
}
static const struct tnl_ptk_info ipip_tpi = {
/* no tunnel info required for ipip. */
.proto = htons(ETH_P_IP),
};
#if IS_ENABLED(CONFIG_MPLS)
static const struct tnl_ptk_info mplsip_tpi = {
/* no tunnel info required for mplsip. */
.proto = htons(ETH_P_MPLS_UC),
};
#endif
static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
{
const struct iphdr *iph;
struct ip_tunnel *tunnel;
int sifindex;
sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
iph = ip_hdr(skb);
tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
iph->saddr, iph->daddr, sifindex);
if (tunnel) {
const struct tnl_ptk_info *tpi;
if (tunnel->parms.iph.protocol != ipproto &&
tunnel->parms.iph.protocol != 0)
goto drop;
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
goto drop;
#if IS_ENABLED(CONFIG_MPLS)
if (ipproto == IPPROTO_MPLS)
tpi = &mplsip_tpi;
else
#endif
tpi = &ipip_tpi;
if (iptunnel_pull_header(skb, 0, tpi->proto, false))
goto drop;
skb_reset_mac_header(skb);
return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
}
return 1;
drop:
kfree_skb(skb);
return 0;
}
static int ipip_rcv(struct sk_buff *skb)
{
return sit_tunnel_rcv(skb, IPPROTO_IPIP);
}
#if IS_ENABLED(CONFIG_MPLS)
static int mplsip_rcv(struct sk_buff *skb)
{
return sit_tunnel_rcv(skb, IPPROTO_MPLS);
}
#endif
/*
* If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
* stores the embedded IPv4 address in v4dst and returns true.
*/
static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
__be32 *v4dst)
{
#ifdef CONFIG_IPV6_SIT_6RD
if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
tunnel->ip6rd.prefixlen)) {
unsigned int pbw0, pbi0;
int pbi1;
u32 d;
pbw0 = tunnel->ip6rd.prefixlen >> 5;
pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
d = tunnel->ip6rd.relay_prefixlen < 32 ?
(ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
tunnel->ip6rd.relay_prefixlen : 0;
pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
if (pbi1 > 0)
d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
(32 - pbi1);
*v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
return true;
}
#else
if (v6dst->s6_addr16[0] == htons(0x2002)) {
/* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
memcpy(v4dst, &v6dst->s6_addr16[1], 4);
return true;
}
#endif
return false;
}
static inline __be32 try_6rd(struct ip_tunnel *tunnel,
const struct in6_addr *v6dst)
{
__be32 dst = 0;
check_6rd(tunnel, v6dst, &dst);
return dst;
}
/*
* This function assumes it is being called from dev_queue_xmit()
* and that skb is filled properly by that function.
*/
static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
const struct iphdr *tiph = &tunnel->parms.iph;
const struct ipv6hdr *iph6 = ipv6_hdr(skb);
u8 tos = tunnel->parms.iph.tos;
__be16 df = tiph->frag_off;
struct rtable *rt; /* Route to the other host */
struct net_device *tdev; /* Device to other host */
unsigned int max_headroom; /* The extra header space needed */
__be32 dst = tiph->daddr;
struct flowi4 fl4;
int mtu;
const struct in6_addr *addr6;
int addr_type;
u8 ttl;
u8 protocol = IPPROTO_IPV6;
int t_hlen = tunnel->hlen + sizeof(struct iphdr);
if (tos == 1)
tos = ipv6_get_dsfield(iph6);
/* ISATAP (RFC4214) - must come before 6to4 */
if (dev->priv_flags & IFF_ISATAP) {
struct neighbour *neigh = NULL;
bool do_tx_error = false;
if (skb_dst(skb))
neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
if (!neigh) {
net_dbg_ratelimited("nexthop == NULL\n");
goto tx_error;
}
addr6 = (const struct in6_addr *)&neigh->primary_key;
addr_type = ipv6_addr_type(addr6);
if ((addr_type & IPV6_ADDR_UNICAST) &&
ipv6_addr_is_isatap(addr6))
dst = addr6->s6_addr32[3];
else
do_tx_error = true;
neigh_release(neigh);
if (do_tx_error)
goto tx_error;
}
if (!dst)
dst = try_6rd(tunnel, &iph6->daddr);
if (!dst) {
struct neighbour *neigh = NULL;
bool do_tx_error = false;
if (skb_dst(skb))
neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
if (!neigh) {
net_dbg_ratelimited("nexthop == NULL\n");
goto tx_error;
}
addr6 = (const struct in6_addr *)&neigh->primary_key;
addr_type = ipv6_addr_type(addr6);
if (addr_type == IPV6_ADDR_ANY) {
addr6 = &ipv6_hdr(skb)->daddr;
addr_type = ipv6_addr_type(addr6);
}
if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
dst = addr6->s6_addr32[3];
else
do_tx_error = true;
neigh_release(neigh);
if (do_tx_error)
goto tx_error;
}
flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
0, dst, tiph->saddr, 0, 0,
sock_net_uid(tunnel->net, NULL));
rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
if (!rt) {
rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
if (IS_ERR(rt)) {
DEV_STATS_INC(dev, tx_carrier_errors);
goto tx_error_icmp;
}
dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
}
if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
ip_rt_put(rt);
DEV_STATS_INC(dev, tx_carrier_errors);
goto tx_error_icmp;
}
tdev = rt->dst.dev;
if (tdev == dev) {
ip_rt_put(rt);
DEV_STATS_INC(dev, collisions);
goto tx_error;
}
if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
ip_rt_put(rt);
goto tx_error;
}
if (df) {
mtu = dst_mtu(&rt->dst) - t_hlen;
if (mtu < IPV4_MIN_MTU) {
DEV_STATS_INC(dev, collisions);
ip_rt_put(rt);
goto tx_error;
}
if (mtu < IPV6_MIN_MTU) {
mtu = IPV6_MIN_MTU;
df = 0;
}
if (tunnel->parms.iph.daddr)
skb_dst_update_pmtu_no_confirm(skb, mtu);
if (skb->len > mtu && !skb_is_gso(skb)) {
icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
ip_rt_put(rt);
goto tx_error;
}
}
if (tunnel->err_count > 0) {
if (time_before(jiffies,
tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
tunnel->err_count--;
dst_link_failure(skb);
} else
tunnel->err_count = 0;
}
/*
* Okay, now see if we can stuff it in the buffer as-is.
*/
max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
(skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
if (!new_skb) {
ip_rt_put(rt);
DEV_STATS_INC(dev, tx_dropped);
kfree_skb(skb);
return NETDEV_TX_OK;
}
if (skb->sk)
skb_set_owner_w(new_skb, skb->sk);
dev_kfree_skb(skb);
skb = new_skb;
iph6 = ipv6_hdr(skb);
}
ttl = tiph->ttl;
if (ttl == 0)
ttl = iph6->hop_limit;
tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
if (ip_tunnel_encap(skb, &tunnel->encap, &protocol, &fl4) < 0) {
ip_rt_put(rt);
goto tx_error;
}
skb_set_inner_ipproto(skb, IPPROTO_IPV6);
iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
df, !net_eq(tunnel->net, dev_net(dev)));
return NETDEV_TX_OK;
tx_error_icmp:
dst_link_failure(skb);
tx_error:
kfree_skb(skb);
DEV_STATS_INC(dev, tx_errors);
return NETDEV_TX_OK;
}
static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
struct net_device *dev, u8 ipproto)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
const struct iphdr *tiph = &tunnel->parms.iph;
if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
goto tx_error;
skb_set_inner_ipproto(skb, ipproto);
ip_tunnel_xmit(skb, dev, tiph, ipproto);
return NETDEV_TX_OK;
tx_error:
kfree_skb(skb);
DEV_STATS_INC(dev, tx_errors);
return NETDEV_TX_OK;
}
static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
struct net_device *dev)
{
if (!pskb_inet_may_pull(skb))
goto tx_err;
switch (skb->protocol) {
case htons(ETH_P_IP):
sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
break;
case htons(ETH_P_IPV6):
ipip6_tunnel_xmit(skb, dev);
break;
#if IS_ENABLED(CONFIG_MPLS)
case htons(ETH_P_MPLS_UC):
sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
break;
#endif
default:
goto tx_err;
}
return NETDEV_TX_OK;
tx_err:
DEV_STATS_INC(dev, tx_errors);
kfree_skb(skb);
return NETDEV_TX_OK;
}
static void ipip6_tunnel_bind_dev(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
int t_hlen = tunnel->hlen + sizeof(struct iphdr);
struct net_device *tdev = NULL;
int hlen = LL_MAX_HEADER;
const struct iphdr *iph;
struct flowi4 fl4;
iph = &tunnel->parms.iph;
if (iph->daddr) {
struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
NULL,
iph->daddr, iph->saddr,
0, 0,
IPPROTO_IPV6,
RT_TOS(iph->tos),
tunnel->parms.link);
if (!IS_ERR(rt)) {
tdev = rt->dst.dev;
ip_rt_put(rt);
}
dev->flags |= IFF_POINTOPOINT;
}
if (!tdev && tunnel->parms.link)
tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
if (tdev && !netif_is_l3_master(tdev)) {
int mtu;
mtu = tdev->mtu - t_hlen;
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
WRITE_ONCE(dev->mtu, mtu);
hlen = tdev->hard_header_len + tdev->needed_headroom;
}
dev->needed_headroom = t_hlen + hlen;
}
static void ipip6_tunnel_update(struct ip_tunnel *t,
struct ip_tunnel_parm_kern *p,
__u32 fwmark)
{
struct net *net = t->net;
struct sit_net *sitn = net_generic(net, sit_net_id);
ipip6_tunnel_unlink(sitn, t);
synchronize_net();
t->parms.iph.saddr = p->iph.saddr;
t->parms.iph.daddr = p->iph.daddr;
__dev_addr_set(t->dev, &p->iph.saddr, 4);
memcpy(t->dev->broadcast, &p->iph.daddr, 4);
ipip6_tunnel_link(sitn, t);
t->parms.iph.ttl = p->iph.ttl;
t->parms.iph.tos = p->iph.tos;
t->parms.iph.frag_off = p->iph.frag_off;
if (t->parms.link != p->link || t->fwmark != fwmark) {
t->parms.link = p->link;
t->fwmark = fwmark;
ipip6_tunnel_bind_dev(t->dev);
}
dst_cache_reset(&t->dst_cache);
netdev_state_change(t->dev);
}
#ifdef CONFIG_IPV6_SIT_6RD
static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
struct ip_tunnel_6rd *ip6rd)
{
struct in6_addr prefix;
__be32 relay_prefix;
if (ip6rd->relay_prefixlen > 32 ||
ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
return -EINVAL;
ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
return -EINVAL;
if (ip6rd->relay_prefixlen)
relay_prefix = ip6rd->relay_prefix &
htonl(0xffffffffUL <<
(32 - ip6rd->relay_prefixlen));
else
relay_prefix = 0;
if (relay_prefix != ip6rd->relay_prefix)
return -EINVAL;
t->ip6rd.prefix = prefix;
t->ip6rd.relay_prefix = relay_prefix;
t->ip6rd.prefixlen = ip6rd->prefixlen;
t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
dst_cache_reset(&t->dst_cache);
netdev_state_change(t->dev);
return 0;
}
static int
ipip6_tunnel_get6rd(struct net_device *dev, struct ip_tunnel_parm __user *data)
{
struct ip_tunnel *t = netdev_priv(dev);
struct ip_tunnel_parm_kern p;
struct ip_tunnel_6rd ip6rd;
if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
if (!ip_tunnel_parm_from_user(&p, data))
return -EFAULT;
t = ipip6_tunnel_locate(t->net, &p, 0);
}
if (!t)
t = netdev_priv(dev);
ip6rd.prefix = t->ip6rd.prefix;
ip6rd.relay_prefix = t->ip6rd.relay_prefix;
ip6rd.prefixlen = t->ip6rd.prefixlen;
ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
if (copy_to_user(data, &ip6rd, sizeof(ip6rd)))
return -EFAULT;
return 0;
}
static int
ipip6_tunnel_6rdctl(struct net_device *dev, struct ip_tunnel_6rd __user *data,
int cmd)
{
struct ip_tunnel *t = netdev_priv(dev);
struct ip_tunnel_6rd ip6rd;
int err;
if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
return -EPERM;
if (copy_from_user(&ip6rd, data, sizeof(ip6rd)))
return -EFAULT;
if (cmd != SIOCDEL6RD) {
err = ipip6_tunnel_update_6rd(t, &ip6rd);
if (err < 0)
return err;
} else
ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev));
return 0;
}
#endif /* CONFIG_IPV6_SIT_6RD */
static bool ipip6_valid_ip_proto(u8 ipproto)
{
return ipproto == IPPROTO_IPV6 ||
ipproto == IPPROTO_IPIP ||
#if IS_ENABLED(CONFIG_MPLS)
ipproto == IPPROTO_MPLS ||
#endif
ipproto == 0;
}
static int
__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm_kern *p)
{
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
if (!ipip6_valid_ip_proto(p->iph.protocol))
return -EINVAL;
if (p->iph.version != 4 ||
p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
return -EINVAL;
if (p->iph.ttl)
p->iph.frag_off |= htons(IP_DF);
return 0;
}
static int
ipip6_tunnel_get(struct net_device *dev, struct ip_tunnel_parm_kern *p)
{
struct ip_tunnel *t = netdev_priv(dev);
if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
t = ipip6_tunnel_locate(t->net, p, 0);
if (!t)
t = netdev_priv(dev);
memcpy(p, &t->parms, sizeof(*p));
return 0;
}
static int
ipip6_tunnel_add(struct net_device *dev, struct ip_tunnel_parm_kern *p)
{
struct ip_tunnel *t = netdev_priv(dev);
int err;
err = __ipip6_tunnel_ioctl_validate(t->net, p);
if (err)
return err;
t = ipip6_tunnel_locate(t->net, p, 1);
if (!t)
return -ENOBUFS;
return 0;
}
static int
ipip6_tunnel_change(struct net_device *dev, struct ip_tunnel_parm_kern *p)
{
struct ip_tunnel *t = netdev_priv(dev);
int err;
err = __ipip6_tunnel_ioctl_validate(t->net, p);
if (err)
return err;
t = ipip6_tunnel_locate(t->net, p, 0);
if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
if (!t)
return -ENOENT;
} else {
if (t) {
if (t->dev != dev)
return -EEXIST;
} else {
if (((dev->flags & IFF_POINTOPOINT) && !p->iph.daddr) ||
(!(dev->flags & IFF_POINTOPOINT) && p->iph.daddr))
return -EINVAL;
t = netdev_priv(dev);
}
ipip6_tunnel_update(t, p, t->fwmark);
}
return 0;
}
static int
ipip6_tunnel_del(struct net_device *dev, struct ip_tunnel_parm_kern *p)
{
struct ip_tunnel *t = netdev_priv(dev);
if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
return -EPERM;
if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
t = ipip6_tunnel_locate(t->net, p, 0);
if (!t)
return -ENOENT;
if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev))
return -EPERM;
dev = t->dev;
}
unregister_netdevice(dev);
return 0;
}
static int
ipip6_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm_kern *p,
int cmd)
{
switch (cmd) {
case SIOCGETTUNNEL:
return ipip6_tunnel_get(dev, p);
case SIOCADDTUNNEL:
return ipip6_tunnel_add(dev, p);
case SIOCCHGTUNNEL:
return ipip6_tunnel_change(dev, p);
case SIOCDELTUNNEL:
return ipip6_tunnel_del(dev, p);
default:
return -EINVAL;
}
}
static int
ipip6_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
void __user *data, int cmd)
{
switch (cmd) {
case SIOCGETTUNNEL:
case SIOCADDTUNNEL:
case SIOCCHGTUNNEL:
case SIOCDELTUNNEL:
return ip_tunnel_siocdevprivate(dev, ifr, data, cmd);
case SIOCGETPRL:
return ipip6_tunnel_get_prl(dev, data);
case SIOCADDPRL:
case SIOCDELPRL:
case SIOCCHGPRL:
return ipip6_tunnel_prl_ctl(dev, data, cmd);
#ifdef CONFIG_IPV6_SIT_6RD
case SIOCGET6RD:
return ipip6_tunnel_get6rd(dev, data);
case SIOCADD6RD:
case SIOCCHG6RD:
case SIOCDEL6RD:
return ipip6_tunnel_6rdctl(dev, data, cmd);
#endif
default:
return -EINVAL;
}
}
static const struct net_device_ops ipip6_netdev_ops = {
.ndo_init = ipip6_tunnel_init,
.ndo_uninit = ipip6_tunnel_uninit,
.ndo_start_xmit = sit_tunnel_xmit,
.ndo_siocdevprivate = ipip6_tunnel_siocdevprivate,
.ndo_get_iflink = ip_tunnel_get_iflink,
.ndo_tunnel_ctl = ipip6_tunnel_ctl,
};
static void ipip6_dev_free(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
dst_cache_destroy(&tunnel->dst_cache);
}
#define SIT_FEATURES (NETIF_F_SG | \
NETIF_F_FRAGLIST | \
NETIF_F_HIGHDMA | \
NETIF_F_GSO_SOFTWARE | \
NETIF_F_HW_CSUM)
static void ipip6_tunnel_setup(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
int t_hlen = tunnel->hlen + sizeof(struct iphdr);
dev->netdev_ops = &ipip6_netdev_ops;
dev->header_ops = &ip_tunnel_header_ops;
dev->needs_free_netdev = true;
dev->priv_destructor = ipip6_dev_free;
dev->type = ARPHRD_SIT;
dev->mtu = ETH_DATA_LEN - t_hlen;
dev->min_mtu = IPV6_MIN_MTU;
dev->max_mtu = IP6_MAX_MTU - t_hlen;
dev->flags = IFF_NOARP;
netif_keep_dst(dev);
dev->addr_len = 4;
dev->features |= NETIF_F_LLTX;
dev->features |= SIT_FEATURES;
dev->hw_features |= SIT_FEATURES;
dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
}
static int ipip6_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
int err;
tunnel->dev = dev;
tunnel->net = dev_net(dev);
strcpy(tunnel->parms.name, dev->name);
ipip6_tunnel_bind_dev(dev);
err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
if (err)
return err;
netdev_hold(dev, &tunnel->dev_tracker, GFP_KERNEL);
netdev_lockdep_set_classes(dev);
return 0;
}
static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct iphdr *iph = &tunnel->parms.iph;
struct net *net = dev_net(dev);
struct sit_net *sitn = net_generic(net, sit_net_id);
iph->version = 4;
iph->protocol = IPPROTO_IPV6;
iph->ihl = 5;
iph->ttl = 64;
rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
}
static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
u8 proto;
if (!data || !data[IFLA_IPTUN_PROTO])
return 0;
proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
if (!ipip6_valid_ip_proto(proto))
return -EINVAL;
return 0;
}
static void ipip6_netlink_parms(struct nlattr *data[],
struct ip_tunnel_parm_kern *parms,
__u32 *fwmark)
{
memset(parms, 0, sizeof(*parms));
parms->iph.version = 4;
parms->iph.protocol = IPPROTO_IPV6;
parms->iph.ihl = 5;
parms->iph.ttl = 64;
if (!data)
return;
ip_tunnel_netlink_parms(data, parms);
if (data[IFLA_IPTUN_FWMARK])
*fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
}
#ifdef CONFIG_IPV6_SIT_6RD
/* This function returns true when 6RD attributes are present in the nl msg */
static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
struct ip_tunnel_6rd *ip6rd)
{
bool ret = false;
memset(ip6rd, 0, sizeof(*ip6rd));
if (!data)
return ret;
if (data[IFLA_IPTUN_6RD_PREFIX]) {
ret = true;
ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
}
if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
ret = true;
ip6rd->relay_prefix =
nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
}
if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
ret = true;
ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
}
if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
ret = true;
ip6rd->relay_prefixlen =
nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
}
return ret;
}
#endif
static int ipip6_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct net *net = dev_net(dev);
struct ip_tunnel *nt;
struct ip_tunnel_encap ipencap;
#ifdef CONFIG_IPV6_SIT_6RD
struct ip_tunnel_6rd ip6rd;
#endif
int err;
nt = netdev_priv(dev);
if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
err = ip_tunnel_encap_setup(nt, &ipencap);
if (err < 0)
return err;
}
ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
if (ipip6_tunnel_locate(net, &nt->parms, 0))
return -EEXIST;
err = ipip6_tunnel_create(dev);
if (err < 0)
return err;
if (tb[IFLA_MTU]) {
u32 mtu = nla_get_u32(tb[IFLA_MTU]);
if (mtu >= IPV6_MIN_MTU &&
mtu <= IP6_MAX_MTU - dev->hard_header_len)
dev->mtu = mtu;
}
#ifdef CONFIG_IPV6_SIT_6RD
if (ipip6_netlink_6rd_parms(data, &ip6rd)) {
err = ipip6_tunnel_update_6rd(nt, &ip6rd);
if (err < 0)
unregister_netdevice_queue(dev, NULL);
}
#endif
return err;
}
static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct ip_tunnel *t = netdev_priv(dev);
struct ip_tunnel_encap ipencap;
struct ip_tunnel_parm_kern p;
struct net *net = t->net;
struct sit_net *sitn = net_generic(net, sit_net_id);
#ifdef CONFIG_IPV6_SIT_6RD
struct ip_tunnel_6rd ip6rd;
#endif
__u32 fwmark = t->fwmark;
int err;
if (dev == sitn->fb_tunnel_dev)
return -EINVAL;
if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
err = ip_tunnel_encap_setup(t, &ipencap);
if (err < 0)
return err;
}
ipip6_netlink_parms(data, &p, &fwmark);
if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
(!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
return -EINVAL;
t = ipip6_tunnel_locate(net, &p, 0);
if (t) {
if (t->dev != dev)
return -EEXIST;
} else
t = netdev_priv(dev);
ipip6_tunnel_update(t, &p, fwmark);
#ifdef CONFIG_IPV6_SIT_6RD
if (ipip6_netlink_6rd_parms(data, &ip6rd))
return ipip6_tunnel_update_6rd(t, &ip6rd);
#endif
return 0;
}
static size_t ipip6_get_size(const struct net_device *dev)
{
return
/* IFLA_IPTUN_LINK */
nla_total_size(4) +
/* IFLA_IPTUN_LOCAL */
nla_total_size(4) +
/* IFLA_IPTUN_REMOTE */
nla_total_size(4) +
/* IFLA_IPTUN_TTL */
nla_total_size(1) +
/* IFLA_IPTUN_TOS */
nla_total_size(1) +
/* IFLA_IPTUN_PMTUDISC */
nla_total_size(1) +
/* IFLA_IPTUN_FLAGS */
nla_total_size(2) +
/* IFLA_IPTUN_PROTO */
nla_total_size(1) +
#ifdef CONFIG_IPV6_SIT_6RD
/* IFLA_IPTUN_6RD_PREFIX */
nla_total_size(sizeof(struct in6_addr)) +
/* IFLA_IPTUN_6RD_RELAY_PREFIX */
nla_total_size(4) +
/* IFLA_IPTUN_6RD_PREFIXLEN */
nla_total_size(2) +
/* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
nla_total_size(2) +
#endif
/* IFLA_IPTUN_ENCAP_TYPE */
nla_total_size(2) +
/* IFLA_IPTUN_ENCAP_FLAGS */
nla_total_size(2) +
/* IFLA_IPTUN_ENCAP_SPORT */
nla_total_size(2) +
/* IFLA_IPTUN_ENCAP_DPORT */
nla_total_size(2) +
/* IFLA_IPTUN_FWMARK */
nla_total_size(4) +
0;
}
static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct ip_tunnel_parm_kern *parm = &tunnel->parms;
if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
!!(parm->iph.frag_off & htons(IP_DF))) ||
nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
nla_put_be16(skb, IFLA_IPTUN_FLAGS,
ip_tunnel_flags_to_be16(parm->i_flags)) ||
nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
goto nla_put_failure;
#ifdef CONFIG_IPV6_SIT_6RD
if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
&tunnel->ip6rd.prefix) ||
nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
tunnel->ip6rd.relay_prefix) ||
nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
tunnel->ip6rd.prefixlen) ||
nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
tunnel->ip6rd.relay_prefixlen))
goto nla_put_failure;
#endif
if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
tunnel->encap.type) ||
nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
tunnel->encap.sport) ||
nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
tunnel->encap.dport) ||
nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
tunnel->encap.flags))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
[IFLA_IPTUN_LINK] = { .type = NLA_U32 },
[IFLA_IPTUN_LOCAL] = { .type = NLA_U32 },
[IFLA_IPTUN_REMOTE] = { .type = NLA_U32 },
[IFLA_IPTUN_TTL] = { .type = NLA_U8 },
[IFLA_IPTUN_TOS] = { .type = NLA_U8 },
[IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 },
[IFLA_IPTUN_FLAGS] = { .type = NLA_U16 },
[IFLA_IPTUN_PROTO] = { .type = NLA_U8 },
#ifdef CONFIG_IPV6_SIT_6RD
[IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) },
[IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 },
[IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 },
[IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
#endif
[IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 },
[IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 },
[IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 },
[IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 },
[IFLA_IPTUN_FWMARK] = { .type = NLA_U32 },
};
static void ipip6_dellink(struct net_device *dev, struct list_head *head)
{
struct net *net = dev_net(dev);
struct sit_net *sitn = net_generic(net, sit_net_id);
if (dev != sitn->fb_tunnel_dev)
unregister_netdevice_queue(dev, head);
}
static struct rtnl_link_ops sit_link_ops __read_mostly = {
.kind = "sit",
.maxtype = IFLA_IPTUN_MAX,
.policy = ipip6_policy,
.priv_size = sizeof(struct ip_tunnel),
.setup = ipip6_tunnel_setup,
.validate = ipip6_validate,
.newlink = ipip6_newlink,
.changelink = ipip6_changelink,
.get_size = ipip6_get_size,
.fill_info = ipip6_fill_info,
.dellink = ipip6_dellink,
.get_link_net = ip_tunnel_get_link_net,
};
static struct xfrm_tunnel sit_handler __read_mostly = {
.handler = ipip6_rcv,
.err_handler = ipip6_err,
.priority = 1,
};
static struct xfrm_tunnel ipip_handler __read_mostly = {
.handler = ipip_rcv,
.err_handler = ipip6_err,
.priority = 2,
};
#if IS_ENABLED(CONFIG_MPLS)
static struct xfrm_tunnel mplsip_handler __read_mostly = {
.handler = mplsip_rcv,
.err_handler = ipip6_err,
.priority = 2,
};
#endif
static void __net_exit sit_destroy_tunnels(struct net *net,
struct list_head *head)
{
struct sit_net *sitn = net_generic(net, sit_net_id);
struct net_device *dev, *aux;
int prio;
for_each_netdev_safe(net, dev, aux)
if (dev->rtnl_link_ops == &sit_link_ops)
unregister_netdevice_queue(dev, head);
for (prio = 0; prio < 4; prio++) {
int h;
for (h = 0; h < (prio ? IP6_SIT_HASH_SIZE : 1); h++) {
struct ip_tunnel *t;
t = rtnl_dereference(sitn->tunnels[prio][h]);
while (t) {
/* If dev is in the same netns, it has already
* been added to the list by the previous loop.
*/
if (!net_eq(dev_net(t->dev), net))
unregister_netdevice_queue(t->dev,
head);
t = rtnl_dereference(t->next);
}
}
}
}
static int __net_init sit_init_net(struct net *net)
{
struct sit_net *sitn = net_generic(net, sit_net_id);
struct ip_tunnel *t;
int err;
sitn->tunnels[0] = sitn->tunnels_wc;
sitn->tunnels[1] = sitn->tunnels_l;
sitn->tunnels[2] = sitn->tunnels_r;
sitn->tunnels[3] = sitn->tunnels_r_l;
if (!net_has_fallback_tunnels(net))
return 0;
sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
NET_NAME_UNKNOWN,
ipip6_tunnel_setup);
if (!sitn->fb_tunnel_dev) {
err = -ENOMEM;
goto err_alloc_dev;
}
dev_net_set(sitn->fb_tunnel_dev, net);
sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
/* FB netdevice is special: we have one, and only one per netns.
* Allowing to move it to another netns is clearly unsafe.
*/
sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
err = register_netdev(sitn->fb_tunnel_dev);
if (err)
goto err_reg_dev;
ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
t = netdev_priv(sitn->fb_tunnel_dev);
strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
return 0;
err_reg_dev:
free_netdev(sitn->fb_tunnel_dev);
err_alloc_dev:
return err;
}
static void __net_exit sit_exit_batch_rtnl(struct list_head *net_list,
struct list_head *dev_to_kill)
{
struct net *net;
ASSERT_RTNL();
list_for_each_entry(net, net_list, exit_list)
sit_destroy_tunnels(net, dev_to_kill);
}
static struct pernet_operations sit_net_ops = {
.init = sit_init_net,
.exit_batch_rtnl = sit_exit_batch_rtnl,
.id = &sit_net_id,
.size = sizeof(struct sit_net),
};
static void __exit sit_cleanup(void)
{
rtnl_link_unregister(&sit_link_ops);
xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
#if IS_ENABLED(CONFIG_MPLS)
xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
#endif
unregister_pernet_device(&sit_net_ops);
rcu_barrier(); /* Wait for completion of call_rcu()'s */
}
static int __init sit_init(void)
{
int err;
pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
err = register_pernet_device(&sit_net_ops);
if (err < 0)
return err;
err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
if (err < 0) {
pr_info("%s: can't register ip6ip4\n", __func__);
goto xfrm_tunnel_failed;
}
err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
if (err < 0) {
pr_info("%s: can't register ip4ip4\n", __func__);
goto xfrm_tunnel4_failed;
}
#if IS_ENABLED(CONFIG_MPLS)
err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
if (err < 0) {
pr_info("%s: can't register mplsip\n", __func__);
goto xfrm_tunnel_mpls_failed;
}
#endif
err = rtnl_link_register(&sit_link_ops);
if (err < 0)
goto rtnl_link_failed;
out:
return err;
rtnl_link_failed:
#if IS_ENABLED(CONFIG_MPLS)
xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
xfrm_tunnel_mpls_failed:
#endif
xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
xfrm_tunnel4_failed:
xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
xfrm_tunnel_failed:
unregister_pernet_device(&sit_net_ops);
goto out;
}
module_init(sit_init);
module_exit(sit_cleanup);
MODULE_DESCRIPTION("IPv6-in-IPv4 tunnel SIT driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_RTNL_LINK("sit");
MODULE_ALIAS_NETDEV("sit0");