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ip6_gre.c
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/*
* GRE over IPv6 protocol decoder.
*
* Authors: Dmitry Kozlov ([email protected])
*
* 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/capability.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/in.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/in6.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/netfilter_ipv4.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/hash.h>
#include <linux/if_tunnel.h>
#include <linux/ip6_tunnel.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/ip_tunnels.h>
#include <net/icmp.h>
#include <net/protocol.h>
#include <net/addrconf.h>
#include <net/arp.h>
#include <net/checksum.h>
#include <net/dsfield.h>
#include <net/inet_ecn.h>
#include <net/xfrm.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/rtnetlink.h>
#include <net/ipv6.h>
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
#include <net/ip6_tunnel.h>
#include <net/gre.h>
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");
#define IP6_GRE_HASH_SIZE_SHIFT 5
#define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT)
static unsigned int ip6gre_net_id __read_mostly;
struct ip6gre_net {
struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE];
struct net_device *fb_tunnel_dev;
};
static struct rtnl_link_ops ip6gre_link_ops __read_mostly;
static struct rtnl_link_ops ip6gre_tap_ops __read_mostly;
static int ip6gre_tunnel_init(struct net_device *dev);
static void ip6gre_tunnel_setup(struct net_device *dev);
static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t);
static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu);
/* Tunnel hash table */
/*
4 hash tables:
3: (remote,local)
2: (remote,*)
1: (*,local)
0: (*,*)
We require exact key match i.e. if a key is present in packet
it will match only tunnel with the same key; if it is not present,
it will match only keyless tunnel.
All keysless packets, if not matched configured keyless tunnels
will match fallback tunnel.
*/
#define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(IP6_GRE_HASH_SIZE - 1))
static u32 HASH_ADDR(const struct in6_addr *addr)
{
u32 hash = ipv6_addr_hash(addr);
return hash_32(hash, IP6_GRE_HASH_SIZE_SHIFT);
}
#define tunnels_r_l tunnels[3]
#define tunnels_r tunnels[2]
#define tunnels_l tunnels[1]
#define tunnels_wc tunnels[0]
/* Given src, dst and key, find appropriate for input tunnel. */
static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev,
const struct in6_addr *remote, const struct in6_addr *local,
__be32 key, __be16 gre_proto)
{
struct net *net = dev_net(dev);
int link = dev->ifindex;
unsigned int h0 = HASH_ADDR(remote);
unsigned int h1 = HASH_KEY(key);
struct ip6_tnl *t, *cand = NULL;
struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
ARPHRD_ETHER : ARPHRD_IP6GRE;
int score, cand_score = 4;
for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) {
if (!ipv6_addr_equal(local, &t->parms.laddr) ||
!ipv6_addr_equal(remote, &t->parms.raddr) ||
key != t->parms.i_key ||
!(t->dev->flags & IFF_UP))
continue;
if (t->dev->type != ARPHRD_IP6GRE &&
t->dev->type != dev_type)
continue;
score = 0;
if (t->parms.link != link)
score |= 1;
if (t->dev->type != dev_type)
score |= 2;
if (score == 0)
return t;
if (score < cand_score) {
cand = t;
cand_score = score;
}
}
for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) {
if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
key != t->parms.i_key ||
!(t->dev->flags & IFF_UP))
continue;
if (t->dev->type != ARPHRD_IP6GRE &&
t->dev->type != dev_type)
continue;
score = 0;
if (t->parms.link != link)
score |= 1;
if (t->dev->type != dev_type)
score |= 2;
if (score == 0)
return t;
if (score < cand_score) {
cand = t;
cand_score = score;
}
}
for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) {
if ((!ipv6_addr_equal(local, &t->parms.laddr) &&
(!ipv6_addr_equal(local, &t->parms.raddr) ||
!ipv6_addr_is_multicast(local))) ||
key != t->parms.i_key ||
!(t->dev->flags & IFF_UP))
continue;
if (t->dev->type != ARPHRD_IP6GRE &&
t->dev->type != dev_type)
continue;
score = 0;
if (t->parms.link != link)
score |= 1;
if (t->dev->type != dev_type)
score |= 2;
if (score == 0)
return t;
if (score < cand_score) {
cand = t;
cand_score = score;
}
}
for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) {
if (t->parms.i_key != key ||
!(t->dev->flags & IFF_UP))
continue;
if (t->dev->type != ARPHRD_IP6GRE &&
t->dev->type != dev_type)
continue;
score = 0;
if (t->parms.link != link)
score |= 1;
if (t->dev->type != dev_type)
score |= 2;
if (score == 0)
return t;
if (score < cand_score) {
cand = t;
cand_score = score;
}
}
if (cand)
return cand;
dev = ign->fb_tunnel_dev;
if (dev->flags & IFF_UP)
return netdev_priv(dev);
return NULL;
}
static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign,
const struct __ip6_tnl_parm *p)
{
const struct in6_addr *remote = &p->raddr;
const struct in6_addr *local = &p->laddr;
unsigned int h = HASH_KEY(p->i_key);
int prio = 0;
if (!ipv6_addr_any(local))
prio |= 1;
if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) {
prio |= 2;
h ^= HASH_ADDR(remote);
}
return &ign->tunnels[prio][h];
}
static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign,
const struct ip6_tnl *t)
{
return __ip6gre_bucket(ign, &t->parms);
}
static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t)
{
struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t);
rcu_assign_pointer(t->next, rtnl_dereference(*tp));
rcu_assign_pointer(*tp, t);
}
static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t)
{
struct ip6_tnl __rcu **tp;
struct ip6_tnl *iter;
for (tp = ip6gre_bucket(ign, t);
(iter = rtnl_dereference(*tp)) != NULL;
tp = &iter->next) {
if (t == iter) {
rcu_assign_pointer(*tp, t->next);
break;
}
}
}
static struct ip6_tnl *ip6gre_tunnel_find(struct net *net,
const struct __ip6_tnl_parm *parms,
int type)
{
const struct in6_addr *remote = &parms->raddr;
const struct in6_addr *local = &parms->laddr;
__be32 key = parms->i_key;
int link = parms->link;
struct ip6_tnl *t;
struct ip6_tnl __rcu **tp;
struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
for (tp = __ip6gre_bucket(ign, parms);
(t = rtnl_dereference(*tp)) != NULL;
tp = &t->next)
if (ipv6_addr_equal(local, &t->parms.laddr) &&
ipv6_addr_equal(remote, &t->parms.raddr) &&
key == t->parms.i_key &&
link == t->parms.link &&
type == t->dev->type)
break;
return t;
}
static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net,
const struct __ip6_tnl_parm *parms, int create)
{
struct ip6_tnl *t, *nt;
struct net_device *dev;
char name[IFNAMSIZ];
struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE);
if (t && create)
return NULL;
if (t || !create)
return t;
if (parms->name[0])
strlcpy(name, parms->name, IFNAMSIZ);
else
strcpy(name, "ip6gre%d");
dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
ip6gre_tunnel_setup);
if (!dev)
return NULL;
dev_net_set(dev, net);
nt = netdev_priv(dev);
nt->parms = *parms;
dev->rtnl_link_ops = &ip6gre_link_ops;
nt->dev = dev;
nt->net = dev_net(dev);
ip6gre_tnl_link_config(nt, 1);
if (register_netdevice(dev) < 0)
goto failed_free;
/* Can use a lockless transmit, unless we generate output sequences */
if (!(nt->parms.o_flags & TUNNEL_SEQ))
dev->features |= NETIF_F_LLTX;
dev_hold(dev);
ip6gre_tunnel_link(ign, nt);
return nt;
failed_free:
free_netdev(dev);
return NULL;
}
static void ip6gre_tunnel_uninit(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
ip6gre_tunnel_unlink(ign, t);
dst_cache_reset(&t->dst_cache);
dev_put(dev);
}
static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
struct net *net = dev_net(skb->dev);
const struct gre_base_hdr *greh;
const struct ipv6hdr *ipv6h;
int grehlen = sizeof(*greh);
struct ip6_tnl *t;
int key_off = 0;
__be16 flags;
__be32 key;
if (!pskb_may_pull(skb, offset + grehlen))
return;
greh = (const struct gre_base_hdr *)(skb->data + offset);
flags = greh->flags;
if (flags & (GRE_VERSION | GRE_ROUTING))
return;
if (flags & GRE_CSUM)
grehlen += 4;
if (flags & GRE_KEY) {
key_off = grehlen + offset;
grehlen += 4;
}
if (!pskb_may_pull(skb, offset + grehlen))
return;
ipv6h = (const struct ipv6hdr *)skb->data;
greh = (const struct gre_base_hdr *)(skb->data + offset);
key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
key, greh->protocol);
if (!t)
return;
switch (type) {
struct ipv6_tlv_tnl_enc_lim *tel;
__u32 teli;
case ICMPV6_DEST_UNREACH:
net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
t->parms.name);
if (code != ICMPV6_PORT_UNREACH)
break;
return;
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);
break;
}
return;
case ICMPV6_PARAMPROB:
teli = 0;
if (code == ICMPV6_HDR_FIELD)
teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
if (teli && teli == be32_to_cpu(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);
}
} else {
net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
t->parms.name);
}
return;
case ICMPV6_PKT_TOOBIG:
ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
return;
case NDISC_REDIRECT:
ip6_redirect(skb, net, skb->dev->ifindex, 0,
sock_net_uid(net, NULL));
return;
}
if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO))
t->err_count++;
else
t->err_count = 1;
t->err_time = jiffies;
}
static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
{
const struct ipv6hdr *ipv6h;
struct ip6_tnl *tunnel;
ipv6h = ipv6_hdr(skb);
tunnel = ip6gre_tunnel_lookup(skb->dev,
&ipv6h->saddr, &ipv6h->daddr, tpi->key,
tpi->proto);
if (tunnel) {
ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
return PACKET_RCVD;
}
return PACKET_REJECT;
}
static int gre_rcv(struct sk_buff *skb)
{
struct tnl_ptk_info tpi;
bool csum_err = false;
int hdr_len;
hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0);
if (hdr_len < 0)
goto drop;
if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
goto drop;
if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
return 0;
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
drop:
kfree_skb(skb);
return 0;
}
static int gre_handle_offloads(struct sk_buff *skb, bool csum)
{
return iptunnel_handle_offloads(skb,
csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
}
static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
struct net_device *dev, __u8 dsfield,
struct flowi6 *fl6, int encap_limit,
__u32 *pmtu, __be16 proto)
{
struct ip6_tnl *tunnel = netdev_priv(dev);
__be16 protocol;
if (dev->type == ARPHRD_ETHER)
IPCB(skb)->flags = 0;
if (dev->header_ops && dev->type == ARPHRD_IP6GRE)
fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr;
else
fl6->daddr = tunnel->parms.raddr;
if (tunnel->parms.o_flags & TUNNEL_SEQ)
tunnel->o_seqno++;
/* Push GRE header. */
protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto;
gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags,
protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno));
return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu,
NEXTHDR_GRE);
}
static inline int ip6gre_xmit_ipv4(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;
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
encap_limit = t->parms.encap_limit;
memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
dsfield = ipv4_get_dsfield(iph);
else
dsfield = ip6_tclass(t->parms.flowinfo);
if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
fl6.flowi6_mark = skb->mark;
else
fl6.flowi6_mark = t->parms.fwmark;
fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
if (err)
return -1;
err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
skb->protocol);
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 ip6gre_xmit_ipv6(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 (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
return -1;
offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
/* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
ipv6h = ipv6_hdr(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));
if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
dsfield = ipv6_get_dsfield(ipv6h);
else
dsfield = ip6_tclass(t->parms.flowinfo);
if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
fl6.flowlabel |= ip6_flowlabel(ipv6h);
if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
fl6.flowi6_mark = skb->mark;
else
fl6.flowi6_mark = t->parms.fwmark;
fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)))
return -1;
err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit,
&mtu, skb->protocol);
if (err != 0) {
if (err == -EMSGSIZE)
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
return -1;
}
return 0;
}
/**
* 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 ip6gre_tnl_addr_conflict(const struct ip6_tnl *t,
const struct ipv6hdr *hdr)
{
return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
}
static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
int encap_limit = -1;
struct flowi6 fl6;
__u32 mtu;
int err;
if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
encap_limit = t->parms.encap_limit;
memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM));
if (err)
return err;
err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol);
return err;
}
static netdev_tx_t ip6gre_tunnel_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;
if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr))
goto tx_err;
switch (skb->protocol) {
case htons(ETH_P_IP):
ret = ip6gre_xmit_ipv4(skb, dev);
break;
case htons(ETH_P_IPV6):
ret = ip6gre_xmit_ipv6(skb, dev);
break;
default:
ret = ip6gre_xmit_other(skb, dev);
break;
}
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 ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu)
{
struct net_device *dev = t->dev;
struct __ip6_tnl_parm *p = &t->parms;
struct flowi6 *fl6 = &t->fl.u.ip6;
int t_hlen;
if (dev->type != ARPHRD_ETHER) {
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;
fl6->flowi6_proto = IPPROTO_GRE;
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->type != ARPHRD_ETHER)
dev->flags |= IFF_POINTOPOINT;
else
dev->flags &= ~IFF_POINTOPOINT;
t->tun_hlen = gre_calc_hlen(t->parms.o_flags);
t->hlen = t->encap_hlen + t->tun_hlen;
t_hlen = t->hlen + sizeof(struct ipv6hdr);
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(t->net,
&p->raddr, &p->laddr,
p->link, strict);
if (!rt)
return;
if (rt->dst.dev) {
dev->hard_header_len = rt->dst.dev->hard_header_len +
t_hlen;
if (set_mtu) {
dev->mtu = rt->dst.dev->mtu - t_hlen;
if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
dev->mtu -= 8;
if (dev->type == ARPHRD_ETHER)
dev->mtu -= ETH_HLEN;
if (dev->mtu < IPV6_MIN_MTU)
dev->mtu = IPV6_MIN_MTU;
}
}
ip6_rt_put(rt);
}
}
static int ip6gre_tnl_change(struct ip6_tnl *t,
const struct __ip6_tnl_parm *p, int set_mtu)
{
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;
t->parms.i_key = p->i_key;
t->parms.o_key = p->o_key;
t->parms.i_flags = p->i_flags;
t->parms.o_flags = p->o_flags;
t->parms.fwmark = p->fwmark;
dst_cache_reset(&t->dst_cache);
ip6gre_tnl_link_config(t, set_mtu);
return 0;
}
static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p,
const struct ip6_tnl_parm2 *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->i_key = u->i_key;
p->o_key = u->o_key;
p->i_flags = gre_flags_to_tnl_flags(u->i_flags);
p->o_flags = gre_flags_to_tnl_flags(u->o_flags);
memcpy(p->name, u->name, sizeof(u->name));
}
static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u,
const struct __ip6_tnl_parm *p)
{
u->proto = IPPROTO_GRE;
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->i_key = p->i_key;
u->o_key = p->o_key;
u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
memcpy(u->name, p->name, sizeof(u->name));
}
static int ip6gre_tunnel_ioctl(struct net_device *dev,
struct ifreq *ifr, int cmd)
{
int err = 0;
struct ip6_tnl_parm2 p;
struct __ip6_tnl_parm p1;
struct ip6_tnl *t = netdev_priv(dev);
struct net *net = t->net;
struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
memset(&p1, 0, sizeof(p1));
switch (cmd) {
case SIOCGETTUNNEL:
if (dev == ign->fb_tunnel_dev) {
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
err = -EFAULT;
break;
}
ip6gre_tnl_parm_from_user(&p1, &p);
t = ip6gre_tunnel_locate(net, &p1, 0);
if (!t)
t = netdev_priv(dev);
}
memset(&p, 0, sizeof(p));
ip6gre_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))
goto done;
err = -EFAULT;
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
goto done;
err = -EINVAL;
if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))
goto done;
if (!(p.i_flags&GRE_KEY))
p.i_key = 0;
if (!(p.o_flags&GRE_KEY))
p.o_key = 0;
ip6gre_tnl_parm_from_user(&p1, &p);
t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL);
if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
if (t) {
if (t->dev != dev) {
err = -EEXIST;
break;
}
} else {
t = netdev_priv(dev);
ip6gre_tunnel_unlink(ign, t);
synchronize_net();
ip6gre_tnl_change(t, &p1, 1);
ip6gre_tunnel_link(ign, t);
netdev_state_change(dev);
}
}
if (t) {
err = 0;
memset(&p, 0, sizeof(p));
ip6gre_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))
goto done;
if (dev == ign->fb_tunnel_dev) {
err = -EFAULT;
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
goto done;
err = -ENOENT;
ip6gre_tnl_parm_from_user(&p1, &p);
t = ip6gre_tunnel_locate(net, &p1, 0);
if (!t)
goto done;
err = -EPERM;
if (t == netdev_priv(ign->fb_tunnel_dev))
goto done;
dev = t->dev;
}
unregister_netdevice(dev);
err = 0;
break;
default:
err = -EINVAL;
}
done:
return err;
}
static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
unsigned short type, const void *daddr,
const void *saddr, unsigned int len)
{
struct ip6_tnl *t = netdev_priv(dev);
struct ipv6hdr *ipv6h;
__be16 *p;
ipv6h = skb_push(skb, t->hlen + sizeof(*ipv6h));
ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb,
t->fl.u.ip6.flowlabel,
true, &t->fl.u.ip6));
ipv6h->hop_limit = t->parms.hop_limit;
ipv6h->nexthdr = NEXTHDR_GRE;
ipv6h->saddr = t->parms.laddr;
ipv6h->daddr = t->parms.raddr;
p = (__be16 *)(ipv6h + 1);
p[0] = t->parms.o_flags;
p[1] = htons(type);
/*
* Set the source hardware address.
*/
if (saddr)
memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr));
if (daddr)
memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr));
if (!ipv6_addr_any(&ipv6h->daddr))
return t->hlen;
return -t->hlen;
}
static const struct header_ops ip6gre_header_ops = {
.create = ip6gre_header,
};
static const struct net_device_ops ip6gre_netdev_ops = {
.ndo_init = ip6gre_tunnel_init,
.ndo_uninit = ip6gre_tunnel_uninit,
.ndo_start_xmit = ip6gre_tunnel_xmit,
.ndo_do_ioctl = ip6gre_tunnel_ioctl,
.ndo_change_mtu = ip6_tnl_change_mtu,
.ndo_get_stats64 = ip_tunnel_get_stats64,
.ndo_get_iflink = ip6_tnl_get_iflink,
};
static void ip6gre_dev_free(struct net_device *dev)
{
struct ip6_tnl *t = netdev_priv(dev);
dst_cache_destroy(&t->dst_cache);
free_percpu(dev->tstats);
}