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ipv6 sit: 6rd (IPv6 Rapid Deployment) Support.
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IPv6 Rapid Deployment (6rd; draft-ietf-softwire-ipv6-6rd) builds upon
mechanisms of 6to4 (RFC3056) to enable a service provider to rapidly
deploy IPv6 unicast service to IPv4 sites to which it provides
customer premise equipment.  Like 6to4, it utilizes stateless IPv6 in
IPv4 encapsulation in order to transit IPv4-only network
infrastructure.  Unlike 6to4, a 6rd service provider uses an IPv6
prefix of its own in place of the fixed 6to4 prefix.

With this option enabled, the SIT driver offers 6rd functionality by
providing additional ioctl API to configure the IPv6 Prefix for in
stead of static 2002::/16 for 6to4.

Original patch was done by Alexandre Cassen <[email protected]>
based on old Internet-Draft.

Signed-off-by: YOSHIFUJI Hideaki <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@yoshfuji @davem330
yoshfuji authored and davem330 committed Oct 7, 2009
1 parent ee5e81f commit fa857af
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Showing 4 changed files with 159 additions and 8 deletions.
11 changes: 11 additions & 0 deletions include/linux/if_tunnel.h
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Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,10 @@
#define SIOCADDPRL (SIOCDEVPRIVATE + 5)
#define SIOCDELPRL (SIOCDEVPRIVATE + 6)
#define SIOCCHGPRL (SIOCDEVPRIVATE + 7)
#define SIOCGET6RD (SIOCDEVPRIVATE + 8)
#define SIOCADD6RD (SIOCDEVPRIVATE + 9)
#define SIOCDEL6RD (SIOCDEVPRIVATE + 10)
#define SIOCCHG6RD (SIOCDEVPRIVATE + 11)

#define GRE_CSUM __cpu_to_be16(0x8000)
#define GRE_ROUTING __cpu_to_be16(0x4000)
Expand Down Expand Up @@ -51,6 +55,13 @@ struct ip_tunnel_prl {
/* PRL flags */
#define PRL_DEFAULT 0x0001

struct ip_tunnel_6rd {
struct in6_addr prefix;
__be32 relay_prefix;
__u16 prefixlen;
__u16 relay_prefixlen;
};

enum
{
IFLA_GRE_UNSPEC,
Expand Down
13 changes: 13 additions & 0 deletions include/net/ipip.h
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Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,15 @@
/* Keep error state on tunnel for 30 sec */
#define IPTUNNEL_ERR_TIMEO (30*HZ)

/* 6rd prefix/relay information */
struct ip_tunnel_6rd_parm
{
struct in6_addr prefix;
__be32 relay_prefix;
u16 prefixlen;
u16 relay_prefixlen;
};

struct ip_tunnel
{
struct ip_tunnel *next;
Expand All @@ -23,6 +32,10 @@ struct ip_tunnel

struct ip_tunnel_parm parms;

/* for SIT */
#ifdef CONFIG_IPV6_SIT_6RD
struct ip_tunnel_6rd_parm ip6rd;
#endif
struct ip_tunnel_prl_entry *prl; /* potential router list */
unsigned int prl_count; /* # of entries in PRL */
};
Expand Down
19 changes: 19 additions & 0 deletions net/ipv6/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -170,6 +170,25 @@ config IPV6_SIT

Saying M here will produce a module called sit. If unsure, say Y.

config IPV6_SIT_6RD
bool "IPv6: IPv6 Rapid Development (6RD) (EXPERIMENTAL)"
depends on IPV6_SIT && EXPERIMENTAL
default n
---help---
IPv6 Rapid Deployment (6rd; draft-ietf-softwire-ipv6-6rd) builds upon
mechanisms of 6to4 (RFC3056) to enable a service provider to rapidly
deploy IPv6 unicast service to IPv4 sites to which it provides
customer premise equipment. Like 6to4, it utilizes stateless IPv6 in
IPv4 encapsulation in order to transit IPv4-only network
infrastructure. Unlike 6to4, a 6rd service provider uses an IPv6
prefix of its own in place of the fixed 6to4 prefix.

With this option enabled, the SIT driver offers 6rd functionality by
providing additional ioctl API to configure the IPv6 Prefix for in
stead of static 2002::/16 for 6to4.

If unsure, say N.

config IPV6_NDISC_NODETYPE
bool

Expand Down
124 changes: 116 additions & 8 deletions net/ipv6/sit.c
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Original file line number Diff line number Diff line change
Expand Up @@ -161,6 +161,21 @@ static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
write_unlock_bh(&ipip6_lock);
}

static void ipip6_tunnel_clone_6rd(struct ip_tunnel *t, struct sit_net *sitn)
{
#ifdef CONFIG_IPV6_SIT_6RD
if (t->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 struct ip_tunnel * ipip6_tunnel_locate(struct net *net,
struct ip_tunnel_parm *parms, int create)
{
Expand Down Expand Up @@ -213,6 +228,8 @@ static struct ip_tunnel * ipip6_tunnel_locate(struct net *net,

dev_hold(dev);

ipip6_tunnel_clone_6rd(t, sitn);

ipip6_tunnel_link(sitn, nt);
return nt;

Expand Down Expand Up @@ -532,17 +549,41 @@ static int ipip6_rcv(struct sk_buff *skb)
return 0;
}

/* Returns the embedded IPv4 address if the IPv6 address
comes from 6to4 (RFC 3056) addr space */

static inline __be32 try_6to4(struct in6_addr *v6dst)
/*
* Returns the embedded IPv4 address if the IPv6 address
* comes from 6rd / 6to4 (RFC 3056) addr space.
*/
static inline
__be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel)
{
__be32 dst = 0;

#ifdef CONFIG_IPV6_SIT_6RD
if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
tunnel->ip6rd.prefixlen)) {
unsigned pbw0, pbi0;
int pbi1;
u32 d;

pbw0 = tunnel->ip6rd.prefixlen >> 5;
pbi0 = tunnel->ip6rd.prefixlen & 0x1f;

d = (ntohl(tunnel->ip6rd.prefix.s6_addr32[pbw0]) << pbi0) >>
tunnel->ip6rd.relay_prefixlen;

pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
if (pbi1 > 0)
d |= ntohl(tunnel->ip6rd.prefix.s6_addr32[pbw0 + 1]) >>
(32 - pbi1);

dst = tunnel->ip6rd.relay_prefix | htonl(d);
}
#else
if (v6dst->s6_addr16[0] == htons(0x2002)) {
/* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
memcpy(&dst, &v6dst->s6_addr16[1], 4);
}
#endif
return dst;
}

Expand Down Expand Up @@ -596,7 +637,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
}

if (!dst)
dst = try_6to4(&iph6->daddr);
dst = try_6rd(&iph6->daddr, tunnel);

if (!dst) {
struct neighbour *neigh = NULL;
Expand Down Expand Up @@ -786,9 +827,15 @@ ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
struct ip_tunnel *t;
struct net *net = dev_net(dev);
struct sit_net *sitn = net_generic(net, sit_net_id);
#ifdef CONFIG_IPV6_SIT_6RD
struct ip_tunnel_6rd ip6rd;
#endif

switch (cmd) {
case SIOCGETTUNNEL:
#ifdef CONFIG_IPV6_SIT_6RD
case SIOCGET6RD:
#endif
t = NULL;
if (dev == sitn->fb_tunnel_dev) {
if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
Expand All @@ -799,9 +846,25 @@ ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
}
if (t == NULL)
t = netdev_priv(dev);
memcpy(&p, &t->parms, sizeof(p));
if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
err = -EFAULT;

err = -EFAULT;
if (cmd == SIOCGETTUNNEL) {
memcpy(&p, &t->parms, sizeof(p));
if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
sizeof(p)))
goto done;
#ifdef CONFIG_IPV6_SIT_6RD
} else {
ipv6_addr_copy(&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(ifr->ifr_ifru.ifru_data, &ip6rd,
sizeof(ip6rd)))
goto done;
#endif
}
err = 0;
break;

case SIOCADDTUNNEL:
Expand Down Expand Up @@ -922,6 +985,51 @@ ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
netdev_state_change(dev);
break;

#ifdef CONFIG_IPV6_SIT_6RD
case SIOCADD6RD:
case SIOCCHG6RD:
case SIOCDEL6RD:
err = -EPERM;
if (!capable(CAP_NET_ADMIN))
goto done;

err = -EFAULT;
if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
sizeof(ip6rd)))
goto done;

t = netdev_priv(dev);

if (cmd != SIOCDEL6RD) {
struct in6_addr prefix;
__be32 relay_prefix;

err = -EINVAL;
if (ip6rd.relay_prefixlen > 32 ||
ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
goto done;

ipv6_addr_prefix(&prefix, &ip6rd.prefix,
ip6rd.prefixlen);
if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
goto done;
relay_prefix = ip6rd.relay_prefix &
htonl(0xffffffffUL <<
(32 - ip6rd.relay_prefixlen));
if (relay_prefix != ip6rd.relay_prefix)
goto done;

ipv6_addr_copy(&t->ip6rd.prefix, &prefix);
t->ip6rd.relay_prefix = relay_prefix;
t->ip6rd.prefixlen = ip6rd.prefixlen;
t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
} else
ipip6_tunnel_clone_6rd(t, sitn);

err = 0;
break;
#endif

default:
err = -EINVAL;
}
Expand Down

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