diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/ipv6/sit.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/ipv6/sit.c')
-rw-r--r-- | net/ipv6/sit.c | 833 |
1 files changed, 833 insertions, 0 deletions
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c new file mode 100644 index 000000000000..b788f55e139b --- /dev/null +++ b/net/ipv6/sit.c @@ -0,0 +1,833 @@ +/* + * 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> + * + * $Id: sit.c,v 1.53 2001/09/25 05:09:53 davem Exp $ + * + * 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. + * + * Changes: + * Roger Venning <r.venning@telstra.com>: 6to4 support + * Nate Thompson <nate@thebog.net>: 6to4 support + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/sched.h> +#include <linux/net.h> +#include <linux/in6.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/icmp.h> +#include <asm/uaccess.h> +#include <linux/init.h> +#include <linux/netfilter_ipv4.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/ipip.h> +#include <net/inet_ecn.h> +#include <net/xfrm.h> +#include <net/dsfield.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 HASH_SIZE 16 +#define HASH(addr) ((addr^(addr>>4))&0xF) + +static int ipip6_fb_tunnel_init(struct net_device *dev); +static int ipip6_tunnel_init(struct net_device *dev); +static void ipip6_tunnel_setup(struct net_device *dev); + +static struct net_device *ipip6_fb_tunnel_dev; + +static struct ip_tunnel *tunnels_r_l[HASH_SIZE]; +static struct ip_tunnel *tunnels_r[HASH_SIZE]; +static struct ip_tunnel *tunnels_l[HASH_SIZE]; +static struct ip_tunnel *tunnels_wc[1]; +static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l }; + +static DEFINE_RWLOCK(ipip6_lock); + +static struct ip_tunnel * ipip6_tunnel_lookup(u32 remote, u32 local) +{ + unsigned h0 = HASH(remote); + unsigned h1 = HASH(local); + struct ip_tunnel *t; + + for (t = tunnels_r_l[h0^h1]; t; t = t->next) { + if (local == t->parms.iph.saddr && + remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) + return t; + } + for (t = tunnels_r[h0]; t; t = t->next) { + if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) + return t; + } + for (t = tunnels_l[h1]; t; t = t->next) { + if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) + return t; + } + if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP)) + return t; + return NULL; +} + +static struct ip_tunnel ** ipip6_bucket(struct ip_tunnel *t) +{ + u32 remote = t->parms.iph.daddr; + u32 local = t->parms.iph.saddr; + unsigned h = 0; + int prio = 0; + + if (remote) { + prio |= 2; + h ^= HASH(remote); + } + if (local) { + prio |= 1; + h ^= HASH(local); + } + return &tunnels[prio][h]; +} + +static void ipip6_tunnel_unlink(struct ip_tunnel *t) +{ + struct ip_tunnel **tp; + + for (tp = ipip6_bucket(t); *tp; tp = &(*tp)->next) { + if (t == *tp) { + write_lock_bh(&ipip6_lock); + *tp = t->next; + write_unlock_bh(&ipip6_lock); + break; + } + } +} + +static void ipip6_tunnel_link(struct ip_tunnel *t) +{ + struct ip_tunnel **tp = ipip6_bucket(t); + + t->next = *tp; + write_lock_bh(&ipip6_lock); + *tp = t; + write_unlock_bh(&ipip6_lock); +} + +static struct ip_tunnel * ipip6_tunnel_locate(struct ip_tunnel_parm *parms, int create) +{ + u32 remote = parms->iph.daddr; + u32 local = parms->iph.saddr; + struct ip_tunnel *t, **tp, *nt; + struct net_device *dev; + unsigned h = 0; + int prio = 0; + char name[IFNAMSIZ]; + + if (remote) { + prio |= 2; + h ^= HASH(remote); + } + if (local) { + prio |= 1; + h ^= HASH(local); + } + for (tp = &tunnels[prio][h]; (t = *tp) != NULL; tp = &t->next) { + if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) + return t; + } + if (!create) + goto failed; + + if (parms->name[0]) + strlcpy(name, parms->name, IFNAMSIZ); + else { + int i; + for (i=1; i<100; i++) { + sprintf(name, "sit%d", i); + if (__dev_get_by_name(name) == NULL) + break; + } + if (i==100) + goto failed; + } + + dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); + if (dev == NULL) + return NULL; + + nt = dev->priv; + dev->init = ipip6_tunnel_init; + nt->parms = *parms; + + if (register_netdevice(dev) < 0) { + free_netdev(dev); + goto failed; + } + + dev_hold(dev); + + ipip6_tunnel_link(nt); + /* Do not decrement MOD_USE_COUNT here. */ + return nt; + +failed: + return NULL; +} + +static void ipip6_tunnel_uninit(struct net_device *dev) +{ + if (dev == ipip6_fb_tunnel_dev) { + write_lock_bh(&ipip6_lock); + tunnels_wc[0] = NULL; + write_unlock_bh(&ipip6_lock); + dev_put(dev); + } else { + ipip6_tunnel_unlink((struct ip_tunnel*)dev->priv); + dev_put(dev); + } +} + + +static void ipip6_err(struct sk_buff *skb, u32 info) +{ +#ifndef I_WISH_WORLD_WERE_PERFECT + +/* It is not :-( All the routers (except for Linux) return only + 8 bytes of packet payload. It means, that precise relaying of + ICMP in the real Internet is absolutely infeasible. + */ + struct iphdr *iph = (struct iphdr*)skb->data; + int type = skb->h.icmph->type; + int code = skb->h.icmph->code; + struct ip_tunnel *t; + + switch (type) { + default: + case ICMP_PARAMETERPROB: + return; + + case ICMP_DEST_UNREACH: + switch (code) { + case ICMP_SR_FAILED: + case ICMP_PORT_UNREACH: + /* Impossible event. */ + return; + case ICMP_FRAG_NEEDED: + /* Soft state for pmtu is maintained by IP core. */ + return; + 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; + break; + } + + read_lock(&ipip6_lock); + t = ipip6_tunnel_lookup(iph->daddr, iph->saddr); + if (t == NULL || t->parms.iph.daddr == 0) + goto out; + if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) + goto out; + + if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) + t->err_count++; + else + t->err_count = 1; + t->err_time = jiffies; +out: + read_unlock(&ipip6_lock); + return; +#else + struct iphdr *iph = (struct iphdr*)dp; + int hlen = iph->ihl<<2; + struct ipv6hdr *iph6; + int type = skb->h.icmph->type; + int code = skb->h.icmph->code; + int rel_type = 0; + int rel_code = 0; + int rel_info = 0; + struct sk_buff *skb2; + struct rt6_info *rt6i; + + if (len < hlen + sizeof(struct ipv6hdr)) + return; + iph6 = (struct ipv6hdr*)(dp + hlen); + + switch (type) { + default: + return; + case ICMP_PARAMETERPROB: + if (skb->h.icmph->un.gateway < hlen) + return; + + /* So... This guy found something strange INSIDE encapsulated + packet. Well, he is fool, but what can we do ? + */ + rel_type = ICMPV6_PARAMPROB; + rel_info = skb->h.icmph->un.gateway - hlen; + break; + + case ICMP_DEST_UNREACH: + switch (code) { + case ICMP_SR_FAILED: + case ICMP_PORT_UNREACH: + /* Impossible event. */ + return; + case ICMP_FRAG_NEEDED: + /* Too complicated case ... */ + return; + default: + /* All others are translated to HOST_UNREACH. + rfc2003 contains "deep thoughts" about NET_UNREACH, + I believe, it is just ether pollution. --ANK + */ + rel_type = ICMPV6_DEST_UNREACH; + rel_code = ICMPV6_ADDR_UNREACH; + break; + } + break; + case ICMP_TIME_EXCEEDED: + if (code != ICMP_EXC_TTL) + return; + rel_type = ICMPV6_TIME_EXCEED; + rel_code = ICMPV6_EXC_HOPLIMIT; + break; + } + + /* Prepare fake skb to feed it to icmpv6_send */ + skb2 = skb_clone(skb, GFP_ATOMIC); + if (skb2 == NULL) + return; + dst_release(skb2->dst); + skb2->dst = NULL; + skb_pull(skb2, skb->data - (u8*)iph6); + skb2->nh.raw = skb2->data; + + /* Try to guess incoming interface */ + rt6i = rt6_lookup(&iph6->saddr, NULL, NULL, 0); + if (rt6i && rt6i->rt6i_dev) { + skb2->dev = rt6i->rt6i_dev; + + rt6i = rt6_lookup(&iph6->daddr, &iph6->saddr, NULL, 0); + + if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) { + struct ip_tunnel * t = (struct ip_tunnel*)rt6i->rt6i_dev->priv; + if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) { + rel_type = ICMPV6_DEST_UNREACH; + rel_code = ICMPV6_ADDR_UNREACH; + } + icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); + } + } + kfree_skb(skb2); + return; +#endif +} + +static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) +{ + if (INET_ECN_is_ce(iph->tos)) + IP6_ECN_set_ce(skb->nh.ipv6h); +} + +static int ipip6_rcv(struct sk_buff *skb) +{ + struct iphdr *iph; + struct ip_tunnel *tunnel; + + if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) + goto out; + + iph = skb->nh.iph; + + read_lock(&ipip6_lock); + if ((tunnel = ipip6_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { + secpath_reset(skb); + skb->mac.raw = skb->nh.raw; + skb->nh.raw = skb->data; + memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); + skb->protocol = htons(ETH_P_IPV6); + skb->pkt_type = PACKET_HOST; + tunnel->stat.rx_packets++; + tunnel->stat.rx_bytes += skb->len; + skb->dev = tunnel->dev; + dst_release(skb->dst); + skb->dst = NULL; + nf_reset(skb); + ipip6_ecn_decapsulate(iph, skb); + netif_rx(skb); + read_unlock(&ipip6_lock); + return 0; + } + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PROT_UNREACH, 0); + kfree_skb(skb); + read_unlock(&ipip6_lock); +out: + return 0; +} + +/* Returns the embedded IPv4 address if the IPv6 address + comes from 6to4 (RFC 3056) addr space */ + +static inline u32 try_6to4(struct in6_addr *v6dst) +{ + u32 dst = 0; + + 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); + } + return dst; +} + +/* + * This function assumes it is being called from dev_queue_xmit() + * and that skb is filled properly by that function. + */ + +static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip_tunnel *tunnel = (struct ip_tunnel*)dev->priv; + struct net_device_stats *stats = &tunnel->stat; + struct iphdr *tiph = &tunnel->parms.iph; + struct ipv6hdr *iph6 = skb->nh.ipv6h; + u8 tos = tunnel->parms.iph.tos; + struct rtable *rt; /* Route to the other host */ + struct net_device *tdev; /* Device to other host */ + struct iphdr *iph; /* Our new IP header */ + int max_headroom; /* The extra header space needed */ + u32 dst = tiph->daddr; + int mtu; + struct in6_addr *addr6; + int addr_type; + + if (tunnel->recursion++) { + tunnel->stat.collisions++; + goto tx_error; + } + + if (skb->protocol != htons(ETH_P_IPV6)) + goto tx_error; + + if (!dst) + dst = try_6to4(&iph6->daddr); + + if (!dst) { + struct neighbour *neigh = NULL; + + if (skb->dst) + neigh = skb->dst->neighbour; + + if (neigh == NULL) { + if (net_ratelimit()) + printk(KERN_DEBUG "sit: nexthop == NULL\n"); + goto tx_error; + } + + addr6 = (struct in6_addr*)&neigh->primary_key; + addr_type = ipv6_addr_type(addr6); + + if (addr_type == IPV6_ADDR_ANY) { + addr6 = &skb->nh.ipv6h->daddr; + addr_type = ipv6_addr_type(addr6); + } + + if ((addr_type & IPV6_ADDR_COMPATv4) == 0) + goto tx_error_icmp; + + dst = addr6->s6_addr32[3]; + } + + { + struct flowi fl = { .nl_u = { .ip4_u = + { .daddr = dst, + .saddr = tiph->saddr, + .tos = RT_TOS(tos) } }, + .oif = tunnel->parms.link, + .proto = IPPROTO_IPV6 }; + if (ip_route_output_key(&rt, &fl)) { + tunnel->stat.tx_carrier_errors++; + goto tx_error_icmp; + } + } + if (rt->rt_type != RTN_UNICAST) { + ip_rt_put(rt); + tunnel->stat.tx_carrier_errors++; + goto tx_error_icmp; + } + tdev = rt->u.dst.dev; + + if (tdev == dev) { + ip_rt_put(rt); + tunnel->stat.collisions++; + goto tx_error; + } + + if (tiph->frag_off) + mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); + else + mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; + + if (mtu < 68) { + tunnel->stat.collisions++; + ip_rt_put(rt); + goto tx_error; + } + if (mtu < IPV6_MIN_MTU) + mtu = IPV6_MIN_MTU; + if (tunnel->parms.iph.daddr && skb->dst) + skb->dst->ops->update_pmtu(skb->dst, mtu); + + if (skb->len > mtu) { + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); + ip_rt_put(rt); + goto tx_error; + } + + if (tunnel->err_count > 0) { + if (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)+sizeof(struct iphdr); + + if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { + struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); + if (!new_skb) { + ip_rt_put(rt); + stats->tx_dropped++; + dev_kfree_skb(skb); + tunnel->recursion--; + return 0; + } + if (skb->sk) + skb_set_owner_w(new_skb, skb->sk); + dev_kfree_skb(skb); + skb = new_skb; + iph6 = skb->nh.ipv6h; + } + + skb->h.raw = skb->nh.raw; + skb->nh.raw = skb_push(skb, sizeof(struct iphdr)); + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); + dst_release(skb->dst); + skb->dst = &rt->u.dst; + + /* + * Push down and install the IPIP header. + */ + + iph = skb->nh.iph; + iph->version = 4; + iph->ihl = sizeof(struct iphdr)>>2; + if (mtu > IPV6_MIN_MTU) + iph->frag_off = htons(IP_DF); + else + iph->frag_off = 0; + + iph->protocol = IPPROTO_IPV6; + iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); + iph->daddr = rt->rt_dst; + iph->saddr = rt->rt_src; + + if ((iph->ttl = tiph->ttl) == 0) + iph->ttl = iph6->hop_limit; + + nf_reset(skb); + + IPTUNNEL_XMIT(); + tunnel->recursion--; + return 0; + +tx_error_icmp: + dst_link_failure(skb); +tx_error: + stats->tx_errors++; + dev_kfree_skb(skb); + tunnel->recursion--; + return 0; +} + +static int +ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) +{ + int err = 0; + struct ip_tunnel_parm p; + struct ip_tunnel *t; + + switch (cmd) { + case SIOCGETTUNNEL: + t = NULL; + if (dev == ipip6_fb_tunnel_dev) { + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { + err = -EFAULT; + break; + } + t = ipip6_tunnel_locate(&p, 0); + } + if (t == NULL) + t = (struct ip_tunnel*)dev->priv; + memcpy(&p, &t->parms, sizeof(p)); + if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) + err = -EFAULT; + break; + + case SIOCADDTUNNEL: + case SIOCCHGTUNNEL: + err = -EPERM; + if (!capable(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.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || + p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) + goto done; + if (p.iph.ttl) + p.iph.frag_off |= htons(IP_DF); + + t = ipip6_tunnel_locate(&p, cmd == SIOCADDTUNNEL); + + if (dev != ipip6_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { + if (t != NULL) { + if (t->dev != dev) { + err = -EEXIST; + break; + } + } else { + if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || + (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { + err = -EINVAL; + break; + } + t = (struct ip_tunnel*)dev->priv; + ipip6_tunnel_unlink(t); + t->parms.iph.saddr = p.iph.saddr; + t->parms.iph.daddr = p.iph.daddr; + memcpy(dev->dev_addr, &p.iph.saddr, 4); + memcpy(dev->broadcast, &p.iph.daddr, 4); + ipip6_tunnel_link(t); + netdev_state_change(dev); + } + } + + if (t) { + err = 0; + if (cmd == SIOCCHGTUNNEL) { + t->parms.iph.ttl = p.iph.ttl; + t->parms.iph.tos = p.iph.tos; + } + if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) + err = -EFAULT; + } else + err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); + break; + + case SIOCDELTUNNEL: + err = -EPERM; + if (!capable(CAP_NET_ADMIN)) + goto done; + + if (dev == ipip6_fb_tunnel_dev) { + err = -EFAULT; + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) + goto done; + err = -ENOENT; + if ((t = ipip6_tunnel_locate(&p, 0)) == NULL) + goto done; + err = -EPERM; + if (t == ipip6_fb_tunnel_dev->priv) + goto done; + dev = t->dev; + } + err = unregister_netdevice(dev); + break; + + default: + err = -EINVAL; + } + +done: + return err; +} + +static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev) +{ + return &(((struct ip_tunnel*)dev->priv)->stat); +} + +static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) +{ + if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) + return -EINVAL; + dev->mtu = new_mtu; + return 0; +} + +static void ipip6_tunnel_setup(struct net_device *dev) +{ + SET_MODULE_OWNER(dev); + dev->uninit = ipip6_tunnel_uninit; + dev->destructor = free_netdev; + dev->hard_start_xmit = ipip6_tunnel_xmit; + dev->get_stats = ipip6_tunnel_get_stats; + dev->do_ioctl = ipip6_tunnel_ioctl; + dev->change_mtu = ipip6_tunnel_change_mtu; + + dev->type = ARPHRD_SIT; + dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); + dev->mtu = 1500 - sizeof(struct iphdr); + dev->flags = IFF_NOARP; + dev->iflink = 0; + dev->addr_len = 4; +} + +static int ipip6_tunnel_init(struct net_device *dev) +{ + struct net_device *tdev = NULL; + struct ip_tunnel *tunnel; + struct iphdr *iph; + + tunnel = (struct ip_tunnel*)dev->priv; + iph = &tunnel->parms.iph; + + tunnel->dev = dev; + strcpy(tunnel->parms.name, dev->name); + + memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); + memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); + + if (iph->daddr) { + struct flowi fl = { .nl_u = { .ip4_u = + { .daddr = iph->daddr, + .saddr = iph->saddr, + .tos = RT_TOS(iph->tos) } }, + .oif = tunnel->parms.link, + .proto = IPPROTO_IPV6 }; + struct rtable *rt; + if (!ip_route_output_key(&rt, &fl)) { + tdev = rt->u.dst.dev; + ip_rt_put(rt); + } + dev->flags |= IFF_POINTOPOINT; + } + + if (!tdev && tunnel->parms.link) + tdev = __dev_get_by_index(tunnel->parms.link); + + if (tdev) { + dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); + dev->mtu = tdev->mtu - sizeof(struct iphdr); + if (dev->mtu < IPV6_MIN_MTU) + dev->mtu = IPV6_MIN_MTU; + } + dev->iflink = tunnel->parms.link; + + return 0; +} + +int __init ipip6_fb_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = dev->priv; + struct iphdr *iph = &tunnel->parms.iph; + + tunnel->dev = dev; + strcpy(tunnel->parms.name, dev->name); + + iph->version = 4; + iph->protocol = IPPROTO_IPV6; + iph->ihl = 5; + iph->ttl = 64; + + dev_hold(dev); + tunnels_wc[0] = tunnel; + return 0; +} + +static struct net_protocol sit_protocol = { + .handler = ipip6_rcv, + .err_handler = ipip6_err, +}; + +void __exit sit_cleanup(void) +{ + inet_del_protocol(&sit_protocol, IPPROTO_IPV6); + unregister_netdev(ipip6_fb_tunnel_dev); +} + +int __init sit_init(void) +{ + int err; + + printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); + + if (inet_add_protocol(&sit_protocol, IPPROTO_IPV6) < 0) { + printk(KERN_INFO "sit init: Can't add protocol\n"); + return -EAGAIN; + } + + ipip6_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", + ipip6_tunnel_setup); + if (!ipip6_fb_tunnel_dev) { + err = -ENOMEM; + goto err1; + } + + ipip6_fb_tunnel_dev->init = ipip6_fb_tunnel_init; + + if ((err = register_netdev(ipip6_fb_tunnel_dev))) + goto err2; + + out: + return err; + err2: + free_netdev(ipip6_fb_tunnel_dev); + err1: + inet_del_protocol(&sit_protocol, IPPROTO_IPV6); + goto out; +} |