/* * IPv6 over IPv6 tunnel device * Linux INET6 implementation * * Authors: * Ville Nuorvala <vnuorval@tcs.hut.fi> * * $Id$ * * Based on: * linux/net/ipv6/sit.c * * RFC 2473 * * 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. * */ #include <linux/config.h> #include <linux/module.h> #include <linux/capability.h> #include <linux/errno.h> #include <linux/types.h> #include <linux/sockios.h> #include <linux/if.h> #include <linux/in.h> #include <linux/ip.h> #include <linux/if_tunnel.h> #include <linux/net.h> #include <linux/in6.h> #include <linux/netdevice.h> #include <linux/if_arp.h> #include <linux/icmpv6.h> #include <linux/init.h> #include <linux/route.h> #include <linux/rtnetlink.h> #include <linux/netfilter_ipv6.h> #include <asm/uaccess.h> #include <asm/atomic.h> #include <net/ip.h> #include <net/ipv6.h> #include <net/ip6_route.h> #include <net/addrconf.h> #include <net/ip6_tunnel.h> #include <net/xfrm.h> #include <net/dsfield.h> #include <net/inet_ecn.h> MODULE_AUTHOR("Ville Nuorvala"); MODULE_DESCRIPTION("IPv6-in-IPv6 tunnel"); MODULE_LICENSE("GPL"); #define IPV6_TLV_TEL_DST_SIZE 8 #ifdef IP6_TNL_DEBUG #define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __FUNCTION__) #else #define IP6_TNL_TRACE(x...) do {;} while(0) #endif #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) #define HASH_SIZE 32 #define HASH(addr) (((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ (HASH_SIZE - 1)) static int ip6ip6_fb_tnl_dev_init(struct net_device *dev); static int ip6ip6_tnl_dev_init(struct net_device *dev); static void ip6ip6_tnl_dev_setup(struct net_device *dev); /* the IPv6 tunnel fallback device */ static struct net_device *ip6ip6_fb_tnl_dev; /* lists for storing tunnels in use */ static struct ip6_tnl *tnls_r_l[HASH_SIZE]; static struct ip6_tnl *tnls_wc[1]; static struct ip6_tnl **tnls[2] = { tnls_wc, tnls_r_l }; /* lock for the tunnel lists */ static DEFINE_RWLOCK(ip6ip6_lock); static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) { struct dst_entry *dst = t->dst_cache; if (dst && dst->obsolete && dst->ops->check(dst, t->dst_cookie) == NULL) { t->dst_cache = NULL; dst_release(dst); return NULL; } return dst; } static inline void ip6_tnl_dst_reset(struct ip6_tnl *t) { dst_release(t->dst_cache); t->dst_cache = NULL; } static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) { struct rt6_info *rt = (struct rt6_info *) dst; t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; dst_release(t->dst_cache); t->dst_cache = dst; } /** * ip6ip6_tnl_lookup - fetch tunnel matching the end-point addresses * @remote: the address of the tunnel exit-point * @local: the address of the tunnel entry-point * * Return: * tunnel matching given end-points if found, * else fallback tunnel if its device is up, * else %NULL **/ static struct ip6_tnl * ip6ip6_tnl_lookup(struct in6_addr *remote, struct in6_addr *local) { unsigned h0 = HASH(remote); unsigned h1 = HASH(local); struct ip6_tnl *t; for (t = tnls_r_l[h0 ^ h1]; t; t = t->next) { if (ipv6_addr_equal(local, &t->parms.laddr) && ipv6_addr_equal(remote, &t->parms.raddr) && (t->dev->flags & IFF_UP)) return t; } if ((t = tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP)) return t; return NULL; } /** * ip6ip6_bucket - get head of list matching given tunnel parameters * @p: parameters containing tunnel end-points * * Description: * ip6ip6_bucket() returns the head of the list matching the * &struct in6_addr entries laddr and raddr in @p. * * Return: head of IPv6 tunnel list **/ static struct ip6_tnl ** ip6ip6_bucket(struct ip6_tnl_parm *p) { struct in6_addr *remote = &p->raddr; struct in6_addr *local = &p->laddr; unsigned h = 0; int prio = 0; if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { prio = 1; h = HASH(remote) ^ HASH(local); } return &tnls[prio][h]; } /** * ip6ip6_tnl_link - add tunnel to hash table * @t: tunnel to be added **/ static void ip6ip6_tnl_link(struct ip6_tnl *t) { struct ip6_tnl **tp = ip6ip6_bucket(&t->parms); t->next = *tp; write_lock_bh(&ip6ip6_lock); *tp = t; write_unlock_bh(&ip6ip6_lock); } /** * ip6ip6_tnl_unlink - remove tunnel from hash table * @t: tunnel to be removed **/ static void ip6ip6_tnl_unlink(struct ip6_tnl *t) { struct ip6_tnl **tp; for (tp = ip6ip6_bucket(&t->parms); *tp; tp = &(*tp)->next) { if (t == *tp) { write_lock_bh(&ip6ip6_lock); *tp = t->next; write_unlock_bh(&ip6ip6_lock); break; } } } /** * ip6_tnl_create() - create a new tunnel * @p: tunnel parameters * @pt: pointer to new tunnel * * Description: * Create tunnel matching given parameters. * * Return: * 0 on success **/ static int ip6_tnl_create(struct ip6_tnl_parm *p, struct ip6_tnl **pt) { struct net_device *dev; struct ip6_tnl *t; char name[IFNAMSIZ]; int err; if (p->name[0]) { strlcpy(name, p->name, IFNAMSIZ); } else { int i; for (i = 1; i < IP6_TNL_MAX; i++) { sprintf(name, "ip6tnl%d", i); if (__dev_get_by_name(name) == NULL) break; } if (i == IP6_TNL_MAX) return -ENOBUFS; } dev = alloc_netdev(sizeof (*t), name, ip6ip6_tnl_dev_setup); if (dev == NULL) return -ENOMEM; t = netdev_priv(dev); dev->init = ip6ip6_tnl_dev_init; t->parms = *p; if ((err = register_netdevice(dev)) < 0) { free_netdev(dev); return err; } dev_hold(dev); ip6ip6_tnl_link(t); *pt = t; return 0; } /** * ip6ip6_tnl_locate - find or create tunnel matching given parameters * @p: tunnel parameters * @create: != 0 if allowed to create new tunnel if no match found * * Description: * ip6ip6_tnl_locate() first tries to locate an existing tunnel * based on @parms. If this is unsuccessful, but @create is set a new * tunnel device is created and registered for use. * * Return: * 0 if tunnel located or created, * -EINVAL if parameters incorrect, * -ENODEV if no matching tunnel available **/ static int ip6ip6_tnl_locate(struct ip6_tnl_parm *p, struct ip6_tnl **pt, int create) { struct in6_addr *remote = &p->raddr; struct in6_addr *local = &p->laddr; struct ip6_tnl *t; if (p->proto != IPPROTO_IPV6) return -EINVAL; for (t = *ip6ip6_bucket(p); t; t = t->next) { if (ipv6_addr_equal(local, &t->parms.laddr) && ipv6_addr_equal(remote, &t->parms.raddr)) { *pt = t; return (create ? -EEXIST : 0); } } if (!create) return -ENODEV; return ip6_tnl_create(p, pt); } /** * ip6ip6_tnl_dev_uninit - tunnel device uninitializer * @dev: the device to be destroyed * * Description: * ip6ip6_tnl_dev_uninit() removes tunnel from its list **/ static void ip6ip6_tnl_dev_uninit(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); if (dev == ip6ip6_fb_tnl_dev) { write_lock_bh(&ip6ip6_lock); tnls_wc[0] = NULL; write_unlock_bh(&ip6ip6_lock); } else { ip6ip6_tnl_unlink(t); } ip6_tnl_dst_reset(t); dev_put(dev); } /** * parse_tvl_tnl_enc_lim - handle encapsulation limit option * @skb: received socket buffer * * Return: * 0 if none was found, * else index to encapsulation limit **/ static __u16 parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw) { struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw; __u8 nexthdr = ipv6h->nexthdr; __u16 off = sizeof (*ipv6h); while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { __u16 optlen = 0; struct ipv6_opt_hdr *hdr; if (raw + off + sizeof (*hdr) > skb->data && !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) break; hdr = (struct ipv6_opt_hdr *) (raw + off); if (nexthdr == NEXTHDR_FRAGMENT) { struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; if (frag_hdr->frag_off) break; optlen = 8; } else if (nexthdr == NEXTHDR_AUTH) { optlen = (hdr->hdrlen + 2) << 2; } else { optlen = ipv6_optlen(hdr); } if (nexthdr == NEXTHDR_DEST) { __u16 i = off + 2; while (1) { struct ipv6_tlv_tnl_enc_lim *tel; /* No more room for encapsulation limit */ if (i + sizeof (*tel) > off + optlen) break; tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; /* return index of option if found and valid */ if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && tel->length == 1) return i; /* else jump to next option */ if (tel->type) i += tel->length + 2; else i++; } } nexthdr = hdr->nexthdr; off += optlen; } return 0; } /** * ip6ip6_err - tunnel error handler * * Description: * ip6ip6_err() should handle errors in the tunnel according * to the specifications in RFC 2473. **/ static int ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, int type, int code, int offset, __u32 info) { struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data; struct ip6_tnl *t; int rel_msg = 0; int rel_type = ICMPV6_DEST_UNREACH; int rel_code = ICMPV6_ADDR_UNREACH; __u32 rel_info = 0; __u16 len; int err = -ENOENT; /* If the packet doesn't contain the original IPv6 header we are in trouble since we might need the source address for further processing of the error. */ read_lock(&ip6ip6_lock); if ((t = ip6ip6_tnl_lookup(&ipv6h->daddr, &ipv6h->saddr)) == NULL) goto out; err = 0; switch (type) { __u32 teli; struct ipv6_tlv_tnl_enc_lim *tel; __u32 mtu; case ICMPV6_DEST_UNREACH: if (net_ratelimit()) printk(KERN_WARNING "%s: Path to destination invalid " "or inactive!\n", t->parms.name); rel_msg = 1; break; case ICMPV6_TIME_EXCEED: if (code == ICMPV6_EXC_HOPLIMIT) { if (net_ratelimit()) printk(KERN_WARNING "%s: Too small hop limit or " "routing loop in tunnel!\n", t->parms.name); rel_msg = 1; } break; case ICMPV6_PARAMPROB: /* ignore if parameter problem not caused by a tunnel encapsulation limit sub-option */ if (code != ICMPV6_HDR_FIELD) { break; } teli = parse_tlv_tnl_enc_lim(skb, skb->data); if (teli && teli == ntohl(info) - 2) { tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; if (tel->encap_limit == 0) { if (net_ratelimit()) printk(KERN_WARNING "%s: Too small encapsulation " "limit or routing loop in " "tunnel!\n", t->parms.name); rel_msg = 1; } } break; case ICMPV6_PKT_TOOBIG: mtu = ntohl(info) - offset; if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; t->dev->mtu = mtu; if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { rel_type = ICMPV6_PKT_TOOBIG; rel_code = 0; rel_info = mtu; rel_msg = 1; } break; } if (rel_msg && pskb_may_pull(skb, offset + sizeof (*ipv6h))) { struct rt6_info *rt; struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); if (!skb2) goto out; dst_release(skb2->dst); skb2->dst = NULL; skb_pull(skb2, offset); skb2->nh.raw = skb2->data; /* Try to guess incoming interface */ rt = rt6_lookup(&skb2->nh.ipv6h->saddr, NULL, 0, 0); if (rt && rt->rt6i_dev) skb2->dev = rt->rt6i_dev; icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); if (rt) dst_release(&rt->u.dst); kfree_skb(skb2); } out: read_unlock(&ip6ip6_lock); return err; } static inline void ip6ip6_ecn_decapsulate(struct ipv6hdr *outer_iph, struct sk_buff *skb) { struct ipv6hdr *inner_iph = skb->nh.ipv6h; if (INET_ECN_is_ce(ipv6_get_dsfield(outer_iph))) IP6_ECN_set_ce(inner_iph); } /** * ip6ip6_rcv - decapsulate IPv6 packet and retransmit it locally * @skb: received socket buffer * * Return: 0 **/ static int ip6ip6_rcv(struct sk_buff *skb) { struct ipv6hdr *ipv6h; struct ip6_tnl *t; ipv6h = skb->nh.ipv6h; read_lock(&ip6ip6_lock); if ((t = ip6ip6_tnl_lookup(&ipv6h->saddr, &ipv6h->daddr)) != NULL) { if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { read_unlock(&ip6ip6_lock); goto discard; } if (!(t->parms.flags & IP6_TNL_F_CAP_RCV)) { t->stat.rx_dropped++; read_unlock(&ip6ip6_lock); goto discard; } secpath_reset(skb); skb->mac.raw = skb->nh.raw; skb->nh.raw = skb->data; skb->protocol = htons(ETH_P_IPV6); skb->pkt_type = PACKET_HOST; memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); skb->dev = t->dev; dst_release(skb->dst); skb->dst = NULL; if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) ipv6_copy_dscp(ipv6h, skb->nh.ipv6h); ip6ip6_ecn_decapsulate(ipv6h, skb); t->stat.rx_packets++; t->stat.rx_bytes += skb->len; netif_rx(skb); read_unlock(&ip6ip6_lock); return 0; } read_unlock(&ip6ip6_lock); return 1; discard: kfree_skb(skb); return 0; } static inline struct ipv6_txoptions *create_tel(__u8 encap_limit) { struct ipv6_tlv_tnl_enc_lim *tel; struct ipv6_txoptions *opt; __u8 *raw; int opt_len = sizeof(*opt) + 8; if (!(opt = kmalloc(opt_len, GFP_ATOMIC))) { return NULL; } memset(opt, 0, opt_len); opt->tot_len = opt_len; opt->dst0opt = (struct ipv6_opt_hdr *) (opt + 1); opt->opt_nflen = 8; tel = (struct ipv6_tlv_tnl_enc_lim *) (opt->dst0opt + 1); tel->type = IPV6_TLV_TNL_ENCAP_LIMIT; tel->length = 1; tel->encap_limit = encap_limit; raw = (__u8 *) opt->dst0opt; raw[5] = IPV6_TLV_PADN; raw[6] = 1; return opt; } /** * ip6ip6_tnl_addr_conflict - compare packet addresses to tunnel's own * @t: the outgoing tunnel device * @hdr: IPv6 header from the incoming packet * * Description: * Avoid trivial tunneling loop by checking that tunnel exit-point * doesn't match source of incoming packet. * * Return: * 1 if conflict, * 0 else **/ static inline int ip6ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) { return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); } /** * ip6ip6_tnl_xmit - encapsulate packet and send * @skb: the outgoing socket buffer * @dev: the outgoing tunnel device * * Description: * Build new header and do some sanity checks on the packet before sending * it. * * Return: * 0 **/ static int ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct net_device_stats *stats = &t->stat; struct ipv6hdr *ipv6h = skb->nh.ipv6h; struct ipv6_txoptions *opt = NULL; int encap_limit = -1; __u16 offset; struct flowi fl; struct dst_entry *dst; struct net_device *tdev; int mtu; int max_headroom = sizeof(struct ipv6hdr); u8 proto; int err; int pkt_len; int dsfield; if (t->recursion++) { stats->collisions++; goto tx_err; } if (skb->protocol != htons(ETH_P_IPV6) || !(t->parms.flags & IP6_TNL_F_CAP_XMIT) || ip6ip6_tnl_addr_conflict(t, ipv6h)) { goto tx_err; } if ((offset = parse_tlv_tnl_enc_lim(skb, skb->nh.raw)) > 0) { struct ipv6_tlv_tnl_enc_lim *tel; tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->nh.raw[offset]; if (tel->encap_limit == 0) { icmpv6_send(skb, ICMPV6_PARAMPROB, ICMPV6_HDR_FIELD, offset + 2, skb->dev); goto tx_err; } encap_limit = tel->encap_limit - 1; } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) { encap_limit = t->parms.encap_limit; } memcpy(&fl, &t->fl, sizeof (fl)); proto = fl.proto; dsfield = ipv6_get_dsfield(ipv6h); if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_TCLASS_MASK); if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) fl.fl6_flowlabel |= (*(__u32 *) ipv6h & IPV6_FLOWLABEL_MASK); if (encap_limit >= 0 && (opt = create_tel(encap_limit)) == NULL) goto tx_err; if ((dst = ip6_tnl_dst_check(t)) != NULL) dst_hold(dst); else { dst = ip6_route_output(NULL, &fl); if (dst->error || xfrm_lookup(&dst, &fl, NULL, 0) < 0) goto tx_err_link_failure; } tdev = dst->dev; if (tdev == dev) { stats->collisions++; if (net_ratelimit()) printk(KERN_WARNING "%s: Local routing loop detected!\n", t->parms.name); goto tx_err_dst_release; } mtu = dst_mtu(dst) - sizeof (*ipv6h); if (opt) { max_headroom += 8; mtu -= 8; } if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; if (skb->dst && mtu < dst_mtu(skb->dst)) { struct rt6_info *rt = (struct rt6_info *) skb->dst; rt->rt6i_flags |= RTF_MODIFIED; rt->u.dst.metrics[RTAX_MTU-1] = mtu; } if (skb->len > mtu) { icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); goto tx_err_dst_release; } /* * Okay, now see if we can stuff it in the buffer as-is. */ max_headroom += LL_RESERVED_SPACE(tdev); if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { struct sk_buff *new_skb; if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) goto tx_err_dst_release; if (skb->sk) skb_set_owner_w(new_skb, skb->sk); kfree_skb(skb); skb = new_skb; } dst_release(skb->dst); skb->dst = dst_clone(dst); skb->h.raw = skb->nh.raw; if (opt) ipv6_push_nfrag_opts(skb, opt, &proto, NULL); skb->nh.raw = skb_push(skb, sizeof(struct ipv6hdr)); ipv6h = skb->nh.ipv6h; *(u32*)ipv6h = fl.fl6_flowlabel | htonl(0x60000000); dsfield = INET_ECN_encapsulate(0, dsfield); ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); ipv6h->hop_limit = t->parms.hop_limit; ipv6h->nexthdr = proto; ipv6_addr_copy(&ipv6h->saddr, &fl.fl6_src); ipv6_addr_copy(&ipv6h->daddr, &fl.fl6_dst); nf_reset(skb); pkt_len = skb->len; err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dst->dev, dst_output); if (err == NET_XMIT_SUCCESS || err == NET_XMIT_CN) { stats->tx_bytes += pkt_len; stats->tx_packets++; } else { stats->tx_errors++; stats->tx_aborted_errors++; } ip6_tnl_dst_store(t, dst); kfree(opt); t->recursion--; return 0; tx_err_link_failure: stats->tx_carrier_errors++; dst_link_failure(skb); tx_err_dst_release: dst_release(dst); kfree(opt); tx_err: stats->tx_errors++; stats->tx_dropped++; kfree_skb(skb); t->recursion--; return 0; } static void ip6_tnl_set_cap(struct ip6_tnl *t) { struct ip6_tnl_parm *p = &t->parms; struct in6_addr *laddr = &p->laddr; struct in6_addr *raddr = &p->raddr; int ltype = ipv6_addr_type(laddr); int rtype = ipv6_addr_type(raddr); p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); if (ltype != IPV6_ADDR_ANY && rtype != IPV6_ADDR_ANY && ((ltype|rtype) & (IPV6_ADDR_UNICAST| IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL| IPV6_ADDR_MAPPED|IPV6_ADDR_RESERVED)) == IPV6_ADDR_UNICAST) { struct net_device *ldev = NULL; int l_ok = 1; int r_ok = 1; if (p->link) ldev = dev_get_by_index(p->link); if (ltype&IPV6_ADDR_UNICAST && !ipv6_chk_addr(laddr, ldev, 0)) l_ok = 0; if (rtype&IPV6_ADDR_UNICAST && ipv6_chk_addr(raddr, NULL, 0)) r_ok = 0; if (l_ok && r_ok) { if (ltype&IPV6_ADDR_UNICAST) p->flags |= IP6_TNL_F_CAP_XMIT; if (rtype&IPV6_ADDR_UNICAST) p->flags |= IP6_TNL_F_CAP_RCV; } if (ldev) dev_put(ldev); } } static void ip6ip6_tnl_link_config(struct ip6_tnl *t) { struct net_device *dev = t->dev; struct ip6_tnl_parm *p = &t->parms; struct flowi *fl = &t->fl; memcpy(&dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); memcpy(&dev->broadcast, &p->raddr, sizeof(struct in6_addr)); /* Set up flowi template */ ipv6_addr_copy(&fl->fl6_src, &p->laddr); ipv6_addr_copy(&fl->fl6_dst, &p->raddr); fl->oif = p->link; fl->fl6_flowlabel = 0; if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; ip6_tnl_set_cap(t); if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) dev->flags |= IFF_POINTOPOINT; else dev->flags &= ~IFF_POINTOPOINT; dev->iflink = p->link; if (p->flags & IP6_TNL_F_CAP_XMIT) { struct rt6_info *rt = rt6_lookup(&p->raddr, &p->laddr, p->link, 0); if (rt == NULL) return; if (rt->rt6i_dev) { dev->hard_header_len = rt->rt6i_dev->hard_header_len + sizeof (struct ipv6hdr); dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr); if (dev->mtu < IPV6_MIN_MTU) dev->mtu = IPV6_MIN_MTU; } dst_release(&rt->u.dst); } } /** * ip6ip6_tnl_change - update the tunnel parameters * @t: tunnel to be changed * @p: tunnel configuration parameters * @active: != 0 if tunnel is ready for use * * Description: * ip6ip6_tnl_change() updates the tunnel parameters **/ static int ip6ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p) { ipv6_addr_copy(&t->parms.laddr, &p->laddr); ipv6_addr_copy(&t->parms.raddr, &p->raddr); t->parms.flags = p->flags; t->parms.hop_limit = p->hop_limit; t->parms.encap_limit = p->encap_limit; t->parms.flowinfo = p->flowinfo; t->parms.link = p->link; ip6_tnl_dst_reset(t); ip6ip6_tnl_link_config(t); return 0; } /** * ip6ip6_tnl_ioctl - configure ipv6 tunnels from userspace * @dev: virtual device associated with tunnel * @ifr: parameters passed from userspace * @cmd: command to be performed * * Description: * ip6ip6_tnl_ioctl() is used for managing IPv6 tunnels * from userspace. * * The possible commands are the following: * %SIOCGETTUNNEL: get tunnel parameters for device * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters * %SIOCCHGTUNNEL: change tunnel parameters to those given * %SIOCDELTUNNEL: delete tunnel * * The fallback device "ip6tnl0", created during module * initialization, can be used for creating other tunnel devices. * * Return: * 0 on success, * %-EFAULT if unable to copy data to or from userspace, * %-EPERM if current process hasn't %CAP_NET_ADMIN set * %-EINVAL if passed tunnel parameters are invalid, * %-EEXIST if changing a tunnel's parameters would cause a conflict * %-ENODEV if attempting to change or delete a nonexisting device **/ static int ip6ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) { int err = 0; int create; struct ip6_tnl_parm p; struct ip6_tnl *t = NULL; switch (cmd) { case SIOCGETTUNNEL: if (dev == ip6ip6_fb_tnl_dev) { if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { err = -EFAULT; break; } if ((err = ip6ip6_tnl_locate(&p, &t, 0)) == -ENODEV) t = netdev_priv(dev); else if (err) break; } else t = netdev_priv(dev); 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; create = (cmd == SIOCADDTUNNEL); if (!capable(CAP_NET_ADMIN)) break; if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { err = -EFAULT; break; } if (!create && dev != ip6ip6_fb_tnl_dev) { t = netdev_priv(dev); } if (!t && (err = ip6ip6_tnl_locate(&p, &t, create))) { break; } if (cmd == SIOCCHGTUNNEL) { if (t->dev != dev) { err = -EEXIST; break; } ip6ip6_tnl_unlink(t); err = ip6ip6_tnl_change(t, &p); ip6ip6_tnl_link(t); netdev_state_change(dev); } if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p))) { err = -EFAULT; } else { err = 0; } break; case SIOCDELTUNNEL: err = -EPERM; if (!capable(CAP_NET_ADMIN)) break; if (dev == ip6ip6_fb_tnl_dev) { if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { err = -EFAULT; break; } err = ip6ip6_tnl_locate(&p, &t, 0); if (err) break; if (t == netdev_priv(ip6ip6_fb_tnl_dev)) { err = -EPERM; break; } } else { t = netdev_priv(dev); } err = unregister_netdevice(t->dev); break; default: err = -EINVAL; } return err; } /** * ip6ip6_tnl_get_stats - return the stats for tunnel device * @dev: virtual device associated with tunnel * * Return: stats for device **/ static struct net_device_stats * ip6ip6_tnl_get_stats(struct net_device *dev) { return &(((struct ip6_tnl *)netdev_priv(dev))->stat); } /** * ip6ip6_tnl_change_mtu - change mtu manually for tunnel device * @dev: virtual device associated with tunnel * @new_mtu: the new mtu * * Return: * 0 on success, * %-EINVAL if mtu too small **/ static int ip6ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) { if (new_mtu < IPV6_MIN_MTU) { return -EINVAL; } dev->mtu = new_mtu; return 0; } /** * ip6ip6_tnl_dev_setup - setup virtual tunnel device * @dev: virtual device associated with tunnel * * Description: * Initialize function pointers and device parameters **/ static void ip6ip6_tnl_dev_setup(struct net_device *dev) { SET_MODULE_OWNER(dev); dev->uninit = ip6ip6_tnl_dev_uninit; dev->destructor = free_netdev; dev->hard_start_xmit = ip6ip6_tnl_xmit; dev->get_stats = ip6ip6_tnl_get_stats; dev->do_ioctl = ip6ip6_tnl_ioctl; dev->change_mtu = ip6ip6_tnl_change_mtu; dev->type = ARPHRD_TUNNEL6; dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); dev->flags |= IFF_NOARP; dev->addr_len = sizeof(struct in6_addr); } /** * ip6ip6_tnl_dev_init_gen - general initializer for all tunnel devices * @dev: virtual device associated with tunnel **/ static inline void ip6ip6_tnl_dev_init_gen(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); t->fl.proto = IPPROTO_IPV6; t->dev = dev; strcpy(t->parms.name, dev->name); } /** * ip6ip6_tnl_dev_init - initializer for all non fallback tunnel devices * @dev: virtual device associated with tunnel **/ static int ip6ip6_tnl_dev_init(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); ip6ip6_tnl_dev_init_gen(dev); ip6ip6_tnl_link_config(t); return 0; } /** * ip6ip6_fb_tnl_dev_init - initializer for fallback tunnel device * @dev: fallback device * * Return: 0 **/ static int ip6ip6_fb_tnl_dev_init(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); ip6ip6_tnl_dev_init_gen(dev); dev_hold(dev); tnls_wc[0] = t; return 0; } static struct xfrm6_tunnel ip6ip6_handler = { .handler = ip6ip6_rcv, .err_handler = ip6ip6_err, .priority = 1, }; /** * ip6_tunnel_init - register protocol and reserve needed resources * * Return: 0 on success **/ static int __init ip6_tunnel_init(void) { int err; if (xfrm6_tunnel_register(&ip6ip6_handler)) { printk(KERN_ERR "ip6ip6 init: can't register tunnel\n"); return -EAGAIN; } ip6ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", ip6ip6_tnl_dev_setup); if (!ip6ip6_fb_tnl_dev) { err = -ENOMEM; goto fail; } ip6ip6_fb_tnl_dev->init = ip6ip6_fb_tnl_dev_init; if ((err = register_netdev(ip6ip6_fb_tnl_dev))) { free_netdev(ip6ip6_fb_tnl_dev); goto fail; } return 0; fail: xfrm6_tunnel_deregister(&ip6ip6_handler); return err; } /** * ip6_tunnel_cleanup - free resources and unregister protocol **/ static void __exit ip6_tunnel_cleanup(void) { if (xfrm6_tunnel_deregister(&ip6ip6_handler)) printk(KERN_INFO "ip6ip6 close: can't deregister tunnel\n"); unregister_netdev(ip6ip6_fb_tnl_dev); } module_init(ip6_tunnel_init); module_exit(ip6_tunnel_cleanup);