/* * 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 */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #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/ip_tunnels.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 bool log_ecn_error = true; module_param(log_ecn_error, bool, 0644); MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 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 bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, __be32 *v4dst); static struct rtnl_link_ops sit_link_ops __read_mostly; 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; }; /* * 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(t, 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(t, 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(t, 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 int ipip6_tunnel_create(struct net_device *dev) { struct ip_tunnel *t = netdev_priv(dev); struct net *net = dev_net(dev); struct sit_net *sitn = net_generic(net, sit_net_id); int err; err = ipip6_tunnel_init(dev); if (err < 0) goto out; ipip6_tunnel_clone_6rd(dev, sitn); if ((__force u16)t->parms.i_flags & SIT_ISATAP) dev->priv_flags |= IFF_ISATAP; err = register_netdevice(dev); if (err < 0) goto out; strcpy(t->parms.name, dev->name); dev->rtnl_link_ops = &sit_link_ops; dev_hold(dev); ipip6_tunnel_link(sitn, t); return 0; out: return err; } 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_create(dev) < 0) goto failed_free; 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 ip_tunnel *tunnel = netdev_priv(dev); struct sit_net *sitn = net_generic(tunnel->net, sit_net_id); if (dev == sitn->fb_tunnel_dev) { RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL); } else { ipip6_tunnel_unlink(sitn, tunnel); ipip6_tunnel_del_prl(tunnel, 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; 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; case ICMP_REDIRECT: break; } err = -ENOENT; t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, iph->daddr, iph->saddr); if (t == NULL) goto out; if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { ipv4_update_pmtu(skb, dev_net(skb->dev), info, t->dev->ifindex, 0, IPPROTO_IPV6, 0); err = 0; goto out; } if (type == ICMP_REDIRECT) { ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0, IPPROTO_IPV6, 0); err = 0; goto out; } if (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: return err; } static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr, const struct in6_addr *v6addr) { __be32 v4embed = 0; if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed) return true; return false; } static int ipip6_rcv(struct sk_buff *skb) { const struct iphdr *iph = ip_hdr(skb); struct ip_tunnel *tunnel; int err; tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, iph->saddr, iph->daddr); if (tunnel != NULL) { struct pcpu_tstats *tstats; if (tunnel->parms.iph.protocol != IPPROTO_IPV6 && tunnel->parms.iph.protocol != 0) goto out; 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) { if (!isatap_chksrc(skb, iph, tunnel)) { tunnel->dev->stats.rx_errors++; goto out; } } else if (!(tunnel->dev->flags&IFF_POINTOPOINT)) { if (is_spoofed_6rd(tunnel, iph->saddr, &ipv6_hdr(skb)->saddr) || is_spoofed_6rd(tunnel, iph->daddr, &ipv6_hdr(skb)->daddr)) { tunnel->dev->stats.rx_errors++; goto out; } } __skb_tunnel_rx(skb, tunnel->dev); err = IP_ECN_decapsulate(iph, skb); if (unlikely(err)) { if (log_ecn_error) net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", &iph->saddr, iph->tos); if (err > 1) { ++tunnel->dev->stats.rx_frame_errors; ++tunnel->dev->stats.rx_errors; goto out; } } tstats = this_cpu_ptr(tunnel->dev->tstats); tstats->rx_packets++; tstats->rx_bytes += skb->len; if (tunnel->net != dev_net(tunnel->dev)) skb_scrub_packet(skb); netif_rx(skb); return 0; } /* no tunnel matched, let upstream know, ipsec may handle it */ return 1; out: kfree_skb(skb); return 0; } static const struct tnl_ptk_info tpi = { /* no tunnel info required for ipip. */ .proto = htons(ETH_P_IP), }; static int ipip_rcv(struct sk_buff *skb) { const struct iphdr *iph; struct ip_tunnel *tunnel; if (iptunnel_pull_header(skb, 0, tpi.proto)) goto drop; iph = ip_hdr(skb); tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, iph->saddr, iph->daddr); if (tunnel != NULL) { if (tunnel->parms.iph.protocol != IPPROTO_IPIP && tunnel->parms.iph.protocol != 0) goto drop; if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) goto drop; return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error); } return 1; drop: kfree_skb(skb); return 0; } /* * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function * stores the embedded IPv4 address in v4dst and returns true. */ static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, __be32 *v4dst) { #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); *v4dst = tunnel->ip6rd.relay_prefix | htonl(d); return true; } #else if (v6dst->s6_addr16[0] == htons(0x2002)) { /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ memcpy(v4dst, &v6dst->s6_addr16[1], 4); return true; } #endif return false; } static inline __be32 try_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst) { __be32 dst = 0; check_6rd(tunnel, v6dst, &dst); 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); 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 */ 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; u8 ttl; int err; 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) { net_dbg_ratelimited("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(tunnel, &iph6->daddr); 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) { net_dbg_ratelimited("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(tunnel->net, &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), NULL, 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; } if (tunnel->net != dev_net(dev)) skb_scrub_packet(skb); /* * 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); } ttl = tiph->ttl; if (ttl == 0) ttl = iph6->hop_limit; tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); err = iptunnel_xmit(dev_net(dev), rt, skb, fl4.saddr, fl4.daddr, IPPROTO_IPV6, tos, ttl, df); iptunnel_xmit_stats(err, &dev->stats, dev->tstats); 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 netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip_tunnel *tunnel = netdev_priv(dev); const struct iphdr *tiph = &tunnel->parms.iph; if (likely(!skb->encapsulation)) { skb_reset_inner_headers(skb); skb->encapsulation = 1; } ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP); return NETDEV_TX_OK; } static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) { switch (skb->protocol) { case htons(ETH_P_IP): ipip_tunnel_xmit(skb, dev); break; case htons(ETH_P_IPV6): ipip6_tunnel_xmit(skb, dev); break; default: goto tx_err; } return NETDEV_TX_OK; tx_err: 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(tunnel->net, &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(tunnel->net, 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 void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p) { struct net *net = t->net; struct sit_net *sitn = net_generic(net, sit_net_id); ipip6_tunnel_unlink(sitn, t); synchronize_net(); t->parms.iph.saddr = p->iph.saddr; t->parms.iph.daddr = p->iph.daddr; memcpy(t->dev->dev_addr, &p->iph.saddr, 4); memcpy(t->dev->broadcast, &p->iph.daddr, 4); ipip6_tunnel_link(sitn, t); 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(t->dev); } netdev_state_change(t->dev); } #ifdef CONFIG_IPV6_SIT_6RD static int ipip6_tunnel_update_6rd(struct ip_tunnel *t, struct ip_tunnel_6rd *ip6rd) { struct in6_addr prefix; __be32 relay_prefix; if (ip6rd->relay_prefixlen > 32 || ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64) return -EINVAL; ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen); if (!ipv6_addr_equal(&prefix, &ip6rd->prefix)) return -EINVAL; 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) return -EINVAL; t->ip6rd.prefix = prefix; t->ip6rd.relay_prefix = relay_prefix; t->ip6rd.prefixlen = ip6rd->prefixlen; t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen; netdev_state_change(t->dev); return 0; } #endif 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 (!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.iph.protocol != IPPROTO_IPV6 && p.iph.protocol != IPPROTO_IPIP && p.iph.protocol != 0) goto done; if (p.iph.version != 4 || 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_update(t, &p); } if (t) { err = 0; 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 (!ns_capable(net->user_ns, 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 (!ns_capable(net->user_ns, 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 (!ns_capable(net->user_ns, 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) { err = ipip6_tunnel_update_6rd(t, &ip6rd); if (err < 0) goto done; } 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 = sit_tunnel_xmit, .ndo_do_ioctl = ipip6_tunnel_ioctl, .ndo_change_mtu = ipip6_tunnel_change_mtu, .ndo_get_stats64 = ip_tunnel_get_stats64, }; 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_LLTX; } static int ipip6_tunnel_init(struct net_device *dev) { struct ip_tunnel *tunnel = netdev_priv(dev); tunnel->dev = dev; tunnel->net = dev_net(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; tunnel->net = dev_net(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 int ipip6_validate(struct nlattr *tb[], struct nlattr *data[]) { u8 proto; if (!data || !data[IFLA_IPTUN_PROTO]) return 0; proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); if (proto != IPPROTO_IPV6 && proto != IPPROTO_IPIP && proto != 0) return -EINVAL; return 0; } static void ipip6_netlink_parms(struct nlattr *data[], struct ip_tunnel_parm *parms) { memset(parms, 0, sizeof(*parms)); parms->iph.version = 4; parms->iph.protocol = IPPROTO_IPV6; parms->iph.ihl = 5; parms->iph.ttl = 64; if (!data) return; if (data[IFLA_IPTUN_LINK]) parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); if (data[IFLA_IPTUN_LOCAL]) parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]); if (data[IFLA_IPTUN_REMOTE]) parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]); if (data[IFLA_IPTUN_TTL]) { parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]); if (parms->iph.ttl) parms->iph.frag_off = htons(IP_DF); } if (data[IFLA_IPTUN_TOS]) parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]); if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC])) parms->iph.frag_off = htons(IP_DF); if (data[IFLA_IPTUN_FLAGS]) parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]); if (data[IFLA_IPTUN_PROTO]) parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]); } #ifdef CONFIG_IPV6_SIT_6RD /* This function returns true when 6RD attributes are present in the nl msg */ static bool ipip6_netlink_6rd_parms(struct nlattr *data[], struct ip_tunnel_6rd *ip6rd) { bool ret = false; memset(ip6rd, 0, sizeof(*ip6rd)); if (!data) return ret; if (data[IFLA_IPTUN_6RD_PREFIX]) { ret = true; nla_memcpy(&ip6rd->prefix, data[IFLA_IPTUN_6RD_PREFIX], sizeof(struct in6_addr)); } if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) { ret = true; ip6rd->relay_prefix = nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]); } if (data[IFLA_IPTUN_6RD_PREFIXLEN]) { ret = true; ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]); } if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) { ret = true; ip6rd->relay_prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]); } return ret; } #endif static int ipip6_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct net *net = dev_net(dev); struct ip_tunnel *nt; #ifdef CONFIG_IPV6_SIT_6RD struct ip_tunnel_6rd ip6rd; #endif int err; nt = netdev_priv(dev); ipip6_netlink_parms(data, &nt->parms); if (ipip6_tunnel_locate(net, &nt->parms, 0)) return -EEXIST; err = ipip6_tunnel_create(dev); if (err < 0) return err; #ifdef CONFIG_IPV6_SIT_6RD if (ipip6_netlink_6rd_parms(data, &ip6rd)) err = ipip6_tunnel_update_6rd(nt, &ip6rd); #endif return err; } static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct ip_tunnel *t = netdev_priv(dev); struct ip_tunnel_parm p; struct net *net = t->net; struct sit_net *sitn = net_generic(net, sit_net_id); #ifdef CONFIG_IPV6_SIT_6RD struct ip_tunnel_6rd ip6rd; #endif if (dev == sitn->fb_tunnel_dev) return -EINVAL; ipip6_netlink_parms(data, &p); if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) return -EINVAL; t = ipip6_tunnel_locate(net, &p, 0); if (t) { if (t->dev != dev) return -EEXIST; } else t = netdev_priv(dev); ipip6_tunnel_update(t, &p); #ifdef CONFIG_IPV6_SIT_6RD if (ipip6_netlink_6rd_parms(data, &ip6rd)) return ipip6_tunnel_update_6rd(t, &ip6rd); #endif return 0; } static size_t ipip6_get_size(const struct net_device *dev) { return /* IFLA_IPTUN_LINK */ nla_total_size(4) + /* IFLA_IPTUN_LOCAL */ nla_total_size(4) + /* IFLA_IPTUN_REMOTE */ nla_total_size(4) + /* IFLA_IPTUN_TTL */ nla_total_size(1) + /* IFLA_IPTUN_TOS */ nla_total_size(1) + /* IFLA_IPTUN_PMTUDISC */ nla_total_size(1) + /* IFLA_IPTUN_FLAGS */ nla_total_size(2) + /* IFLA_IPTUN_PROTO */ nla_total_size(1) + #ifdef CONFIG_IPV6_SIT_6RD /* IFLA_IPTUN_6RD_PREFIX */ nla_total_size(sizeof(struct in6_addr)) + /* IFLA_IPTUN_6RD_RELAY_PREFIX */ nla_total_size(4) + /* IFLA_IPTUN_6RD_PREFIXLEN */ nla_total_size(2) + /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */ nla_total_size(2) + #endif 0; } static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev) { struct ip_tunnel *tunnel = netdev_priv(dev); struct ip_tunnel_parm *parm = &tunnel->parms; if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, !!(parm->iph.frag_off & htons(IP_DF))) || nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags)) goto nla_put_failure; #ifdef CONFIG_IPV6_SIT_6RD if (nla_put(skb, IFLA_IPTUN_6RD_PREFIX, sizeof(struct in6_addr), &tunnel->ip6rd.prefix) || nla_put_be32(skb, IFLA_IPTUN_6RD_RELAY_PREFIX, tunnel->ip6rd.relay_prefix) || nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN, tunnel->ip6rd.prefixlen) || nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, tunnel->ip6rd.relay_prefixlen)) goto nla_put_failure; #endif return 0; nla_put_failure: return -EMSGSIZE; } static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 }, [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, #ifdef CONFIG_IPV6_SIT_6RD [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) }, [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 }, [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 }, [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 }, #endif }; static struct rtnl_link_ops sit_link_ops __read_mostly = { .kind = "sit", .maxtype = IFLA_IPTUN_MAX, .policy = ipip6_policy, .priv_size = sizeof(struct ip_tunnel), .setup = ipip6_tunnel_setup, .validate = ipip6_validate, .newlink = ipip6_newlink, .changelink = ipip6_changelink, .get_size = ipip6_get_size, .fill_info = ipip6_fill_info, }; static struct xfrm_tunnel sit_handler __read_mostly = { .handler = ipip6_rcv, .err_handler = ipip6_err, .priority = 1, }; static struct xfrm_tunnel ipip_handler __read_mostly = { .handler = ipip_rcv, .err_handler = ipip6_err, .priority = 2, }; static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) { struct net *net = dev_net(sitn->fb_tunnel_dev); struct net_device *dev, *aux; int prio; for_each_netdev_safe(net, dev, aux) if (dev->rtnl_link_ops == &sit_link_ops) unregister_netdevice_queue(dev, head); 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) { /* If dev is in the same netns, it has already * been added to the list by the previous loop. */ if (dev_net(t->dev) != net) 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); /* FB netdevice is special: we have one, and only one per netns. * Allowing to move it to another netns is clearly unsafe. */ sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 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) { rtnl_link_unregister(&sit_link_ops); xfrm4_tunnel_deregister(&sit_handler, AF_INET6); xfrm4_tunnel_deregister(&ipip_handler, AF_INET); unregister_pernet_device(&sit_net_ops); rcu_barrier(); /* Wait for completion of call_rcu()'s */ } static int __init sit_init(void) { int err; pr_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) { pr_info("%s: can't register ip6ip4\n", __func__); goto xfrm_tunnel_failed; } err = xfrm4_tunnel_register(&ipip_handler, AF_INET); if (err < 0) { pr_info("%s: can't register ip4ip4\n", __func__); goto xfrm_tunnel4_failed; } err = rtnl_link_register(&sit_link_ops); if (err < 0) goto rtnl_link_failed; out: return err; rtnl_link_failed: xfrm4_tunnel_deregister(&ipip_handler, AF_INET); xfrm_tunnel4_failed: xfrm4_tunnel_deregister(&sit_handler, AF_INET6); xfrm_tunnel_failed: unregister_pernet_device(&sit_net_ops); goto out; } module_init(sit_init); module_exit(sit_cleanup); MODULE_LICENSE("GPL"); MODULE_ALIAS_NETDEV("sit0");