diff options
Diffstat (limited to 'net/ipv6/sit.c')
| -rw-r--r-- | net/ipv6/sit.c | 1306 |
1 files changed, 1306 insertions, 0 deletions
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c new file mode 100644 index 00000000..c4ffd174 --- /dev/null +++ b/net/ipv6/sit.c @@ -0,0 +1,1306 @@ +/* + * 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> + * + * 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 + * Fred Templin <fred.l.templin@boeing.com>: isatap support + */ + +#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 <asm/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/ipip.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 HASH_SIZE 16 +#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) + +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 int sit_net_id __read_mostly; +struct sit_net { + struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE]; + struct ip_tunnel __rcu *tunnels_r[HASH_SIZE]; + struct ip_tunnel __rcu *tunnels_l[HASH_SIZE]; + struct ip_tunnel __rcu *tunnels_wc[1]; + struct ip_tunnel __rcu **tunnels[4]; + + struct net_device *fb_tunnel_dev; +}; + +/* + * Locking : hash tables are protected by RCU and RTNL + */ + +#define for_each_ip_tunnel_rcu(start) \ + for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) + +/* often modified stats are per cpu, other are shared (netdev->stats) */ +struct pcpu_tstats { + unsigned long rx_packets; + unsigned long rx_bytes; + unsigned long tx_packets; + unsigned long tx_bytes; +} __attribute__((aligned(4*sizeof(unsigned long)))); + +static struct net_device_stats *ipip6_get_stats(struct net_device *dev) +{ + struct pcpu_tstats sum = { 0 }; + int i; + + for_each_possible_cpu(i) { + const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); + + sum.rx_packets += tstats->rx_packets; + sum.rx_bytes += tstats->rx_bytes; + sum.tx_packets += tstats->tx_packets; + sum.tx_bytes += tstats->tx_bytes; + } + dev->stats.rx_packets = sum.rx_packets; + dev->stats.rx_bytes = sum.rx_bytes; + dev->stats.tx_packets = sum.tx_packets; + dev->stats.tx_bytes = sum.tx_bytes; + return &dev->stats; +} +/* + * 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) +{ + unsigned int h0 = HASH(remote); + unsigned int h1 = HASH(local); + struct ip_tunnel *t; + struct sit_net *sitn = net_generic(net, sit_net_id); + + for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) { + if (local == t->parms.iph.saddr && + remote == t->parms.iph.daddr && + (!dev || !t->parms.link || dev->iflink == t->parms.link) && + (t->dev->flags & IFF_UP)) + return t; + } + for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) { + if (remote == t->parms.iph.daddr && + (!dev || !t->parms.link || dev->iflink == t->parms.link) && + (t->dev->flags & IFF_UP)) + return t; + } + for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) { + if (local == t->parms.iph.saddr && + (!dev || !t->parms.link || dev->iflink == t->parms.link) && + (t->dev->flags & IFF_UP)) + return t; + } + t = rcu_dereference(sitn->tunnels_wc[0]); + if ((t != NULL) && (t->dev->flags & IFF_UP)) + return t; + return NULL; +} + +static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn, + struct ip_tunnel_parm *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 (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) +{ + __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]) + strlcpy(name, parms->name, IFNAMSIZ); + else + strcpy(name, "sit%d"); + + dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); + if (dev == NULL) + return NULL; + + dev_net_set(dev, net); + + nt = netdev_priv(dev); + + nt->parms = *parms; + if (ipip6_tunnel_init(dev) < 0) + goto failed_free; + ipip6_tunnel_clone_6rd(dev, sitn); + + if (parms->i_flags & SIT_ISATAP) + dev->priv_flags |= IFF_ISATAP; + + if (register_netdevice(dev) < 0) + goto failed_free; + + strcpy(nt->parms.name, dev->name); + + dev_hold(dev); + + ipip6_tunnel_link(sitn, nt); + return nt; + +failed_free: + ipip6_dev_free(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 ip_tunnel *t, + struct ip_tunnel_prl __user *a) +{ + struct ip_tunnel_prl kprl, *kp; + struct ip_tunnel_prl_entry *prl; + unsigned int cmax, c = 0, ca, len; + int ret = 0; + + 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) : + NULL; + + rcu_read_lock(); + + ca = t->prl_count < cmax ? 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); + if (!kp) { + ret = -ENOMEM; + goto out; + } + } + + c = 0; + 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; + } +out: + 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); + + 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 +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 net *net = dev_net(dev); + struct sit_net *sitn = net_generic(net, sit_net_id); + + if (dev == sitn->fb_tunnel_dev) { + RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL); + } else { + ipip6_tunnel_unlink(sitn, netdev_priv(dev)); + ipip6_tunnel_del_prl(netdev_priv(dev), NULL); + } + dev_put(dev); +} + + +static int ipip6_err(struct sk_buff *skb, u32 info) +{ + +/* 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. + */ + const struct iphdr *iph = (const struct iphdr *)skb->data; + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + struct ip_tunnel *t; + int err; + + switch (type) { + default: + case ICMP_PARAMETERPROB: + return 0; + + case ICMP_DEST_UNREACH: + switch (code) { + case ICMP_SR_FAILED: + case ICMP_PORT_UNREACH: + /* Impossible event. */ + return 0; + case ICMP_FRAG_NEEDED: + /* Soft state for pmtu is maintained by IP core. */ + 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; + break; + } + + err = -ENOENT; + + rcu_read_lock(); + t = ipip6_tunnel_lookup(dev_net(skb->dev), + skb->dev, + iph->daddr, + iph->saddr); + if (t == NULL || t->parms.iph.daddr == 0) + goto out; + + err = 0; + 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: + rcu_read_unlock(); + return err; +} + +static inline void ipip6_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb) +{ + if (INET_ECN_is_ce(iph->tos)) + IP6_ECN_set_ce(ipv6_hdr(skb)); +} + +static int ipip6_rcv(struct sk_buff *skb) +{ + const struct iphdr *iph; + struct ip_tunnel *tunnel; + + if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) + goto out; + + iph = ip_hdr(skb); + + rcu_read_lock(); + tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, + iph->saddr, iph->daddr); + if (tunnel != NULL) { + struct pcpu_tstats *tstats; + + secpath_reset(skb); + skb->mac_header = skb->network_header; + skb_reset_network_header(skb); + IPCB(skb)->flags = 0; + skb->protocol = htons(ETH_P_IPV6); + skb->pkt_type = PACKET_HOST; + + if ((tunnel->dev->priv_flags & IFF_ISATAP) && + !isatap_chksrc(skb, iph, tunnel)) { + tunnel->dev->stats.rx_errors++; + rcu_read_unlock(); + kfree_skb(skb); + return 0; + } + + tstats = this_cpu_ptr(tunnel->dev->tstats); + tstats->rx_packets++; + tstats->rx_bytes += skb->len; + + __skb_tunnel_rx(skb, tunnel->dev); + + ipip6_ecn_decapsulate(iph, skb); + + netif_rx(skb); + + rcu_read_unlock(); + return 0; + } + + /* no tunnel matched, let upstream know, ipsec may handle it */ + rcu_read_unlock(); + return 1; +out: + kfree_skb(skb); + return 0; +} + +/* + * Returns the embedded IPv4 address if the IPv6 address + * comes from 6rd / 6to4 (RFC 3056) addr space. + */ +static inline +__be32 try_6rd(const 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 int pbw0, pbi0; + int pbi1; + u32 d; + + pbw0 = tunnel->ip6rd.prefixlen >> 5; + pbi0 = tunnel->ip6rd.prefixlen & 0x1f; + + d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> + tunnel->ip6rd.relay_prefixlen; + + pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; + if (pbi1 > 0) + d |= ntohl(v6dst->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; +} + +/* + * 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); + struct pcpu_tstats *tstats; + 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 */ + struct iphdr *iph; /* Our new IP header */ + 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; + + if (skb->protocol != htons(ETH_P_IPV6)) + goto tx_error; + + 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 == NULL) { + if (net_ratelimit()) + printk(KERN_DEBUG "sit: 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(&iph6->daddr, tunnel); + + 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 == NULL) { + if (net_ratelimit()) + printk(KERN_DEBUG "sit: 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; + } + + rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, + dst, tiph->saddr, + 0, 0, + IPPROTO_IPV6, RT_TOS(tos), + tunnel->parms.link); + if (IS_ERR(rt)) { + dev->stats.tx_carrier_errors++; + goto tx_error_icmp; + } + if (rt->rt_type != RTN_UNICAST) { + ip_rt_put(rt); + dev->stats.tx_carrier_errors++; + goto tx_error_icmp; + } + tdev = rt->dst.dev; + + if (tdev == dev) { + ip_rt_put(rt); + dev->stats.collisions++; + goto tx_error; + } + + if (df) { + mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); + + if (mtu < 68) { + dev->stats.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(skb)) + skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); + + if (skb->len > mtu) { + icmpv6_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)+sizeof(struct iphdr); + + 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.tx_dropped++; + dev_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); + } + + skb->transport_header = skb->network_header; + skb_push(skb, sizeof(struct iphdr)); + skb_reset_network_header(skb); + memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); + IPCB(skb)->flags = 0; + skb_dst_drop(skb); + skb_dst_set(skb, &rt->dst); + + /* + * Push down and install the IPIP header. + */ + + iph = ip_hdr(skb); + iph->version = 4; + iph->ihl = sizeof(struct iphdr)>>2; + iph->frag_off = df; + iph->protocol = IPPROTO_IPV6; + iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); + iph->daddr = fl4.daddr; + iph->saddr = fl4.saddr; + + if ((iph->ttl = tiph->ttl) == 0) + iph->ttl = iph6->hop_limit; + + nf_reset(skb); + tstats = this_cpu_ptr(dev->tstats); + __IPTUNNEL_XMIT(tstats, &dev->stats); + return NETDEV_TX_OK; + +tx_error_icmp: + dst_link_failure(skb); +tx_error: + dev->stats.tx_errors++; + dev_kfree_skb(skb); + return NETDEV_TX_OK; +} + +static void ipip6_tunnel_bind_dev(struct net_device *dev) +{ + struct net_device *tdev = NULL; + struct ip_tunnel *tunnel; + const struct iphdr *iph; + struct flowi4 fl4; + + tunnel = netdev_priv(dev); + iph = &tunnel->parms.iph; + + if (iph->daddr) { + struct rtable *rt = ip_route_output_ports(dev_net(dev), &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(dev_net(dev), 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; +} + +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_prl prl; + 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))) { + err = -EFAULT; + break; + } + t = ipip6_tunnel_locate(net, &p, 0); + } + if (t == NULL) + t = netdev_priv(dev); + + 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 { + 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: + 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(net, &p, cmd == SIOCADDTUNNEL); + + if (dev != sitn->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 = netdev_priv(dev); + ipip6_tunnel_unlink(sitn, t); + synchronize_net(); + 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(sitn, 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 (t->parms.link != p.link) { + t->parms.link = p.link; + ipip6_tunnel_bind_dev(dev); + netdev_state_change(dev); + } + } + 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 == sitn->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(net, &p, 0)) == NULL) + goto done; + err = -EPERM; + if (t == netdev_priv(sitn->fb_tunnel_dev)) + goto done; + dev = t->dev; + } + unregister_netdevice(dev); + err = 0; + break; + + case SIOCGETPRL: + err = -EINVAL; + if (dev == sitn->fb_tunnel_dev) + goto done; + err = -ENOENT; + if (!(t = netdev_priv(dev))) + goto done; + err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); + break; + + case SIOCADDPRL: + case SIOCDELPRL: + case SIOCCHGPRL: + err = -EPERM; + if (!capable(CAP_NET_ADMIN)) + goto done; + err = -EINVAL; + if (dev == sitn->fb_tunnel_dev) + goto done; + err = -EFAULT; + if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) + goto done; + err = -ENOENT; + if (!(t = netdev_priv(dev))) + goto done; + + 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; + } + 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; + 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) + goto done; + + 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(dev, sitn); + + err = 0; + break; +#endif + + default: + err = -EINVAL; + } + +done: + return err; +} + +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 const struct net_device_ops ipip6_netdev_ops = { + .ndo_uninit = ipip6_tunnel_uninit, + .ndo_start_xmit = ipip6_tunnel_xmit, + .ndo_do_ioctl = ipip6_tunnel_ioctl, + .ndo_change_mtu = ipip6_tunnel_change_mtu, + .ndo_get_stats = ipip6_get_stats, +}; + +static void ipip6_dev_free(struct net_device *dev) +{ + free_percpu(dev->tstats); + free_netdev(dev); +} + +static void ipip6_tunnel_setup(struct net_device *dev) +{ + dev->netdev_ops = &ipip6_netdev_ops; + dev->destructor = ipip6_dev_free; + + dev->type = ARPHRD_SIT; + dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); + dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); + dev->flags = IFF_NOARP; + dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; + dev->iflink = 0; + dev->addr_len = 4; + dev->features |= NETIF_F_NETNS_LOCAL; + dev->features |= NETIF_F_LLTX; +} + +static int ipip6_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + + tunnel->dev = dev; + + memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); + memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); + + ipip6_tunnel_bind_dev(dev); + dev->tstats = alloc_percpu(struct pcpu_tstats); + if (!dev->tstats) + return -ENOMEM; + + return 0; +} + +static int __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); + + tunnel->dev = dev; + strcpy(tunnel->parms.name, dev->name); + + iph->version = 4; + iph->protocol = IPPROTO_IPV6; + iph->ihl = 5; + iph->ttl = 64; + + dev->tstats = alloc_percpu(struct pcpu_tstats); + if (!dev->tstats) + return -ENOMEM; + dev_hold(dev); + rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); + return 0; +} + +static struct xfrm_tunnel sit_handler __read_mostly = { + .handler = ipip6_rcv, + .err_handler = ipip6_err, + .priority = 1, +}; + +static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) +{ + int prio; + + for (prio = 1; prio < 4; prio++) { + int h; + for (h = 0; h < HASH_SIZE; h++) { + struct ip_tunnel *t; + + t = rtnl_dereference(sitn->tunnels[prio][h]); + while (t != NULL) { + 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; + + sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", + ipip6_tunnel_setup); + if (!sitn->fb_tunnel_dev) { + err = -ENOMEM; + goto err_alloc_dev; + } + dev_net_set(sitn->fb_tunnel_dev, net); + + err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); + if (err) + goto err_dev_free; + + ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); + + if ((err = register_netdev(sitn->fb_tunnel_dev))) + goto err_reg_dev; + + t = netdev_priv(sitn->fb_tunnel_dev); + + strcpy(t->parms.name, sitn->fb_tunnel_dev->name); + return 0; + +err_reg_dev: + dev_put(sitn->fb_tunnel_dev); +err_dev_free: + ipip6_dev_free(sitn->fb_tunnel_dev); +err_alloc_dev: + return err; +} + +static void __net_exit sit_exit_net(struct net *net) +{ + struct sit_net *sitn = net_generic(net, sit_net_id); + LIST_HEAD(list); + + rtnl_lock(); + sit_destroy_tunnels(sitn, &list); + unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); + unregister_netdevice_many(&list); + rtnl_unlock(); +} + +static struct pernet_operations sit_net_ops = { + .init = sit_init_net, + .exit = sit_exit_net, + .id = &sit_net_id, + .size = sizeof(struct sit_net), +}; + +static void __exit sit_cleanup(void) +{ + xfrm4_tunnel_deregister(&sit_handler, AF_INET6); + + unregister_pernet_device(&sit_net_ops); + rcu_barrier(); /* Wait for completion of call_rcu()'s */ +} + +static int __init sit_init(void) +{ + int err; + + printk(KERN_INFO "IPv6 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) { + unregister_pernet_device(&sit_net_ops); + printk(KERN_INFO "sit init: Can't add protocol\n"); + } + return err; +} + +module_init(sit_init); +module_exit(sit_cleanup); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_NETDEV("sit0"); |