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authorYasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>2007-02-15 00:43:16 +0900
committerDavid S. Miller <davem@sunset.davemloft.net>2007-04-25 22:23:40 -0700
commitc4d3efafcc933fd2ffd169d7dc4f980393a13796 (patch)
tree01ecdc7128ae03c29acbd605589a56420bcf95ec
parent[IPV6] IP6TUNNEL: Split out generic routine in ip6ip6_xmit(). (diff)
downloadlinux-dev-c4d3efafcc933fd2ffd169d7dc4f980393a13796.tar.xz
linux-dev-c4d3efafcc933fd2ffd169d7dc4f980393a13796.zip
[IPV6] IP6TUNNEL: Add support to IPv4 over IPv6 tunnel.
Some notes - Protocol number IPPROTO_IPIP is used for IPv4 over IPv6 packets. - If IP6_TNL_F_USE_ORIG_TCLASS is set, TOS in IPv4 header is copied to Traffic Class in outer IPv6 header on xmit. - IP6_TNL_F_USE_ORIG_FLOWLABEL is ignored on xmit of IPv4 packets, because IPv4 header does not have flow label. - Kernel sends ICMP error if IPv4 packet is too big on xmit, even if DF flag is not set. Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv6/ip6_tunnel.c190
1 files changed, 185 insertions, 5 deletions
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 4546bb923a20..a6541495deab 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1,14 +1,15 @@
/*
- * IPv6 over IPv6 tunnel device
+ * IPv6 tunneling device
* Linux INET6 implementation
*
* Authors:
* Ville Nuorvala <vnuorval@tcs.hut.fi>
+ * Yasuyuki Kozakai <kozakai@linux-ipv6.org>
*
* $Id$
*
* Based on:
- * linux/net/ipv6/sit.c
+ * linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
*
* RFC 2473
*
@@ -24,6 +25,7 @@
#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>
@@ -41,6 +43,7 @@
#include <asm/uaccess.h>
#include <asm/atomic.h>
+#include <net/icmp.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ip6_route.h>
@@ -51,7 +54,7 @@
#include <net/inet_ecn.h>
MODULE_AUTHOR("Ville Nuorvala");
-MODULE_DESCRIPTION("IPv6-in-IPv6 tunnel");
+MODULE_DESCRIPTION("IPv6 tunneling device");
MODULE_LICENSE("GPL");
#define IPV6_TLV_TEL_DST_SIZE 8
@@ -63,6 +66,7 @@ MODULE_LICENSE("GPL");
#endif
#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
+#define IPV6_TCLASS_SHIFT 20
#define HASH_SIZE 32
@@ -470,6 +474,104 @@ out:
}
static int
+ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ int type, int code, int offset, __u32 info)
+{
+ int rel_msg = 0;
+ int rel_type = type;
+ int rel_code = code;
+ __u32 rel_info = info;
+ int err;
+ struct sk_buff *skb2;
+ struct iphdr *eiph;
+ struct flowi fl;
+ struct rtable *rt;
+
+ err = ip6_tnl_err(skb, opt, &rel_type, &rel_code, &rel_msg, &rel_info,
+ offset);
+ if (err < 0)
+ return err;
+
+ if (rel_msg == 0)
+ return 0;
+
+ switch (rel_type) {
+ case ICMPV6_DEST_UNREACH:
+ if (rel_code != ICMPV6_ADDR_UNREACH)
+ return 0;
+ rel_type = ICMP_DEST_UNREACH;
+ rel_code = ICMP_HOST_UNREACH;
+ break;
+ case ICMPV6_PKT_TOOBIG:
+ if (rel_code != 0)
+ return 0;
+ rel_type = ICMP_DEST_UNREACH;
+ rel_code = ICMP_FRAG_NEEDED;
+ break;
+ default:
+ return 0;
+ }
+
+ if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
+ return 0;
+
+ skb2 = skb_clone(skb, GFP_ATOMIC);
+ if (!skb2)
+ return 0;
+
+ dst_release(skb2->dst);
+ skb2->dst = NULL;
+ skb_pull(skb2, offset);
+ skb2->nh.raw = skb2->data;
+ eiph = skb2->nh.iph;
+
+ /* Try to guess incoming interface */
+ memset(&fl, 0, sizeof(fl));
+ fl.fl4_dst = eiph->saddr;
+ fl.fl4_tos = RT_TOS(eiph->tos);
+ fl.proto = IPPROTO_IPIP;
+ if (ip_route_output_key(&rt, &fl))
+ goto out;
+
+ skb2->dev = rt->u.dst.dev;
+
+ /* route "incoming" packet */
+ if (rt->rt_flags & RTCF_LOCAL) {
+ ip_rt_put(rt);
+ rt = NULL;
+ fl.fl4_dst = eiph->daddr;
+ fl.fl4_src = eiph->saddr;
+ fl.fl4_tos = eiph->tos;
+ if (ip_route_output_key(&rt, &fl) ||
+ rt->u.dst.dev->type != ARPHRD_TUNNEL) {
+ ip_rt_put(rt);
+ goto out;
+ }
+ } else {
+ ip_rt_put(rt);
+ if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
+ skb2->dev) ||
+ skb2->dst->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(skb2->dst))
+ goto out;
+
+ skb2->dst->ops->update_pmtu(skb2->dst, rel_info);
+ rel_info = htonl(rel_info);
+ }
+
+ icmp_send(skb2, rel_type, rel_code, rel_info);
+
+out:
+ kfree_skb(skb2);
+ return 0;
+}
+
+static int
ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
int type, int code, int offset, __u32 info)
{
@@ -513,6 +615,19 @@ ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
return 0;
}
+static void ip4ip6_dscp_ecn_decapsulate(struct ip6_tnl *t,
+ 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(skb->nh.iph, INET_ECN_MASK, dsfield);
+
+ if (INET_ECN_is_ce(dsfield))
+ IP_ECN_set_ce(skb->nh.iph);
+}
+
static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t,
struct ipv6hdr *ipv6h,
struct sk_buff *skb)
@@ -605,6 +720,11 @@ discard:
return 0;
}
+static int ip4ip6_rcv(struct sk_buff *skb)
+{
+ return ip6_tnl_rcv(skb, ETH_P_IP, ip4ip6_dscp_ecn_decapsulate);
+}
+
static int ip6ip6_rcv(struct sk_buff *skb)
{
return ip6_tnl_rcv(skb, ETH_P_IPV6, ip6ip6_dscp_ecn_decapsulate);
@@ -691,7 +811,7 @@ static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
* it.
*
* Return:
- * 0
+ * 0 on success
* -1 fail
* %-EMSGSIZE message too big. return mtu in this case.
**/
@@ -809,6 +929,44 @@ tx_err_dst_release:
}
static inline int
+ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct ip6_tnl *t = netdev_priv(dev);
+ struct iphdr *iph = skb->nh.iph;
+ int encap_limit = -1;
+ struct flowi fl;
+ __u8 dsfield;
+ __u32 mtu;
+ int err;
+
+ if (!ip6_tnl_xmit_ctl(t))
+ return -1;
+
+ if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
+ encap_limit = t->parms.encap_limit;
+
+ memcpy(&fl, &t->fl, sizeof (fl));
+ fl.proto = IPPROTO_IPIP;
+
+ dsfield = ipv4_get_dsfield(iph);
+
+ if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
+ fl.fl6_flowlabel |= ntohl(((__u32)iph->tos << IPV6_TCLASS_SHIFT)
+ & IPV6_TCLASS_MASK);
+
+ err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, 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);
@@ -867,6 +1025,9 @@ ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
}
switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP):
+ ret = ip4ip6_tnl_xmit(skb, dev);
+ break;
case __constant_htons(ETH_P_IPV6):
ret = ip6ip6_tnl_xmit(skb, dev);
break;
@@ -1199,6 +1360,12 @@ ip6ip6_fb_tnl_dev_init(struct net_device *dev)
return 0;
}
+static struct xfrm6_tunnel ip4ip6_handler = {
+ .handler = ip4ip6_rcv,
+ .err_handler = ip4ip6_err,
+ .priority = 1,
+};
+
static struct xfrm6_tunnel ip6ip6_handler = {
.handler = ip6ip6_rcv,
.err_handler = ip6ip6_err,
@@ -1215,9 +1382,16 @@ static int __init ip6_tunnel_init(void)
{
int err;
+ if (xfrm6_tunnel_register(&ip4ip6_handler, AF_INET)) {
+ printk(KERN_ERR "ip4ip6 init: can't register tunnel\n");
+ err = -EAGAIN;
+ goto out;
+ }
+
if (xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6)) {
printk(KERN_ERR "ip6ip6 init: can't register tunnel\n");
- return -EAGAIN;
+ err = -EAGAIN;
+ goto unreg_ip4ip6;
}
ip6ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
ip6ip6_tnl_dev_setup);
@@ -1235,6 +1409,9 @@ static int __init ip6_tunnel_init(void)
return 0;
fail:
xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
+unreg_ip4ip6:
+ xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
+out:
return err;
}
@@ -1258,6 +1435,9 @@ static void __exit ip6ip6_destroy_tunnels(void)
static void __exit ip6_tunnel_cleanup(void)
{
+ if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
+ printk(KERN_INFO "ip4ip6 close: can't deregister tunnel\n");
+
if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
printk(KERN_INFO "ip6ip6 close: can't deregister tunnel\n");