diff options
Diffstat (limited to 'net/ipv6/ip6_tunnel.c')
| -rw-r--r-- | net/ipv6/ip6_tunnel.c | 1503 |
1 files changed, 1503 insertions, 0 deletions
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c new file mode 100644 index 00000000..0fd027f3 --- /dev/null +++ b/net/ipv6/ip6_tunnel.c @@ -0,0 +1,1503 @@ +/* + * IPv6 tunneling device + * Linux INET6 implementation + * + * Authors: + * Ville Nuorvala <vnuorval@tcs.hut.fi> + * Yasuyuki Kozakai <kozakai@linux-ipv6.org> + * + * Based on: + * linux/net/ipv6/sit.c and linux/net/ipv4/ipip.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/module.h> +#include <linux/capability.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/sockios.h> +#include <linux/icmp.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 <linux/slab.h> + +#include <asm/uaccess.h> +#include <asm/atomic.h> + +#include <net/icmp.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> +#include <net/net_namespace.h> +#include <net/netns/generic.h> + +MODULE_AUTHOR("Ville Nuorvala"); +MODULE_DESCRIPTION("IPv6 tunneling device"); +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", __func__) +#else +#define IP6_TNL_TRACE(x...) do {;} while(0) +#endif + +#define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) +#define IPV6_TCLASS_SHIFT 20 + +#define HASH_SIZE 32 + +#define HASH(addr) ((__force u32)((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ + (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ + (HASH_SIZE - 1)) + +static void ip6_tnl_dev_init(struct net_device *dev); +static void ip6_tnl_dev_setup(struct net_device *dev); + +static int ip6_tnl_net_id __read_mostly; +struct ip6_tnl_net { + /* the IPv6 tunnel fallback device */ + struct net_device *fb_tnl_dev; + /* lists for storing tunnels in use */ + struct ip6_tnl *tnls_r_l[HASH_SIZE]; + struct ip6_tnl *tnls_wc[1]; + struct ip6_tnl **tnls[2]; +}; + +/* + * Locking : hash tables are protected by RCU and a spinlock + */ +static DEFINE_SPINLOCK(ip6_tnl_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; +} + +/** + * ip6_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 + **/ + +#define for_each_ip6_tunnel_rcu(start) \ + for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) + +static struct ip6_tnl * +ip6_tnl_lookup(struct net *net, struct in6_addr *remote, struct in6_addr *local) +{ + unsigned h0 = HASH(remote); + unsigned h1 = HASH(local); + struct ip6_tnl *t; + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[h0 ^ h1]) { + if (ipv6_addr_equal(local, &t->parms.laddr) && + ipv6_addr_equal(remote, &t->parms.raddr) && + (t->dev->flags & IFF_UP)) + return t; + } + t = rcu_dereference(ip6n->tnls_wc[0]); + if (t && (t->dev->flags & IFF_UP)) + return t; + + return NULL; +} + +/** + * ip6_tnl_bucket - get head of list matching given tunnel parameters + * @p: parameters containing tunnel end-points + * + * Description: + * ip6_tnl_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 ** +ip6_tnl_bucket(struct ip6_tnl_net *ip6n, 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 &ip6n->tnls[prio][h]; +} + +/** + * ip6_tnl_link - add tunnel to hash table + * @t: tunnel to be added + **/ + +static void +ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) +{ + struct ip6_tnl **tp = ip6_tnl_bucket(ip6n, &t->parms); + + spin_lock_bh(&ip6_tnl_lock); + t->next = *tp; + rcu_assign_pointer(*tp, t); + spin_unlock_bh(&ip6_tnl_lock); +} + +/** + * ip6_tnl_unlink - remove tunnel from hash table + * @t: tunnel to be removed + **/ + +static void +ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) +{ + struct ip6_tnl **tp; + + for (tp = ip6_tnl_bucket(ip6n, &t->parms); *tp; tp = &(*tp)->next) { + if (t == *tp) { + spin_lock_bh(&ip6_tnl_lock); + *tp = t->next; + spin_unlock_bh(&ip6_tnl_lock); + break; + } + } +} + +/** + * ip6_tnl_create() - create a new tunnel + * @p: tunnel parameters + * @pt: pointer to new tunnel + * + * Description: + * Create tunnel matching given parameters. + * + * Return: + * created tunnel or NULL + **/ + +static struct ip6_tnl *ip6_tnl_create(struct net *net, struct ip6_tnl_parm *p) +{ + struct net_device *dev; + struct ip6_tnl *t; + char name[IFNAMSIZ]; + int err; + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + if (p->name[0]) + strlcpy(name, p->name, IFNAMSIZ); + else + sprintf(name, "ip6tnl%%d"); + + dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup); + if (dev == NULL) + goto failed; + + dev_net_set(dev, net); + + if (strchr(name, '%')) { + if (dev_alloc_name(dev, name) < 0) + goto failed_free; + } + + t = netdev_priv(dev); + t->parms = *p; + ip6_tnl_dev_init(dev); + + if ((err = register_netdevice(dev)) < 0) + goto failed_free; + + dev_hold(dev); + ip6_tnl_link(ip6n, t); + return t; + +failed_free: + free_netdev(dev); +failed: + return NULL; +} + +/** + * ip6_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: + * ip6_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: + * matching tunnel or NULL + **/ + +static struct ip6_tnl *ip6_tnl_locate(struct net *net, + struct ip6_tnl_parm *p, int create) +{ + struct in6_addr *remote = &p->raddr; + struct in6_addr *local = &p->laddr; + struct ip6_tnl *t; + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + for (t = *ip6_tnl_bucket(ip6n, p); t; t = t->next) { + if (ipv6_addr_equal(local, &t->parms.laddr) && + ipv6_addr_equal(remote, &t->parms.raddr)) + return t; + } + if (!create) + return NULL; + return ip6_tnl_create(net, p); +} + +/** + * ip6_tnl_dev_uninit - tunnel device uninitializer + * @dev: the device to be destroyed + * + * Description: + * ip6_tnl_dev_uninit() removes tunnel from its list + **/ + +static void +ip6_tnl_dev_uninit(struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + struct net *net = dev_net(dev); + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + if (dev == ip6n->fb_tnl_dev) { + spin_lock_bh(&ip6_tnl_lock); + ip6n->tnls_wc[0] = NULL; + spin_unlock_bh(&ip6_tnl_lock); + } else { + ip6_tnl_unlink(ip6n, 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; +} + +/** + * ip6_tnl_err - tunnel error handler + * + * Description: + * ip6_tnl_err() should handle errors in the tunnel according + * to the specifications in RFC 2473. + **/ + +static int +ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, + u8 *type, u8 *code, int *msg, __u32 *info, int offset) +{ + struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data; + struct ip6_tnl *t; + int rel_msg = 0; + u8 rel_type = ICMPV6_DEST_UNREACH; + u8 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. */ + + rcu_read_lock(); + if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, + &ipv6h->saddr)) == NULL) + goto out; + + if (t->parms.proto != ipproto && t->parms.proto != 0) + 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: + teli = 0; + if ((*code) == ICMPV6_HDR_FIELD) + teli = parse_tlv_tnl_enc_lim(skb, skb->data); + + if (teli && teli == *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; + } + } else if (net_ratelimit()) { + printk(KERN_WARNING + "%s: Recipient unable to parse tunneled " + "packet!\n ", t->parms.name); + } + break; + case ICMPV6_PKT_TOOBIG: + mtu = *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; + } + + *type = rel_type; + *code = rel_code; + *info = rel_info; + *msg = rel_msg; + +out: + rcu_read_unlock(); + return err; +} + +static int +ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 info) +{ + int rel_msg = 0; + u8 rel_type = type; + u8 rel_code = code; + __u32 rel_info = ntohl(info); + int err; + struct sk_buff *skb2; + struct iphdr *eiph; + struct flowi fl; + struct rtable *rt; + + err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code, + &rel_msg, &rel_info, offset); + if (err < 0) + return err; + + if (rel_msg == 0) + return 0; + + switch (rel_type) { + case ICMPV6_DEST_UNREACH: + if (rel_code != ICMPV6_ADDR_UNREACH) + return 0; + rel_type = ICMP_DEST_UNREACH; + rel_code = ICMP_HOST_UNREACH; + break; + case ICMPV6_PKT_TOOBIG: + if (rel_code != 0) + return 0; + rel_type = ICMP_DEST_UNREACH; + rel_code = ICMP_FRAG_NEEDED; + break; + default: + return 0; + } + + if (!pskb_may_pull(skb, offset + sizeof(struct iphdr))) + return 0; + + skb2 = skb_clone(skb, GFP_ATOMIC); + if (!skb2) + return 0; + + skb_dst_drop(skb2); + + skb_pull(skb2, offset); + skb_reset_network_header(skb2); + eiph = ip_hdr(skb2); + + /* Try to guess incoming interface */ + memset(&fl, 0, sizeof(fl)); + fl.fl4_dst = eiph->saddr; + fl.fl4_tos = RT_TOS(eiph->tos); + fl.proto = IPPROTO_IPIP; + if (ip_route_output_key(dev_net(skb->dev), &rt, &fl)) + goto out; + + skb2->dev = rt->dst.dev; + + /* route "incoming" packet */ + if (rt->rt_flags & RTCF_LOCAL) { + ip_rt_put(rt); + rt = NULL; + fl.fl4_dst = eiph->daddr; + fl.fl4_src = eiph->saddr; + fl.fl4_tos = eiph->tos; + if (ip_route_output_key(dev_net(skb->dev), &rt, &fl) || + rt->dst.dev->type != ARPHRD_TUNNEL) { + ip_rt_put(rt); + goto out; + } + skb_dst_set(skb2, (struct dst_entry *)rt); + } else { + ip_rt_put(rt); + if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, + skb2->dev) || + skb_dst(skb2)->dev->type != ARPHRD_TUNNEL) + goto out; + } + + /* change mtu on this route */ + if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { + if (rel_info > dst_mtu(skb_dst(skb2))) + goto out; + + skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), rel_info); + } + + icmp_send(skb2, rel_type, rel_code, htonl(rel_info)); + +out: + kfree_skb(skb2); + return 0; +} + +static int +ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, + u8 type, u8 code, int offset, __be32 info) +{ + int rel_msg = 0; + u8 rel_type = type; + u8 rel_code = code; + __u32 rel_info = ntohl(info); + int err; + + err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code, + &rel_msg, &rel_info, offset); + if (err < 0) + return err; + + if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) { + struct rt6_info *rt; + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); + + if (!skb2) + return 0; + + skb_dst_drop(skb2); + skb_pull(skb2, offset); + skb_reset_network_header(skb2); + + /* Try to guess incoming interface */ + rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, + NULL, 0, 0); + + if (rt && rt->rt6i_dev) + skb2->dev = rt->rt6i_dev; + + icmpv6_send(skb2, rel_type, rel_code, rel_info); + + if (rt) + dst_release(&rt->dst); + + kfree_skb(skb2); + } + + return 0; +} + +static void ip4ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, + struct ipv6hdr *ipv6h, + struct sk_buff *skb) +{ + __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK; + + if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) + ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield); + + if (INET_ECN_is_ce(dsfield)) + IP_ECN_set_ce(ip_hdr(skb)); +} + +static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, + struct ipv6hdr *ipv6h, + struct sk_buff *skb) +{ + if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) + ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb)); + + if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h))) + IP6_ECN_set_ce(ipv6_hdr(skb)); +} + +/* called with rcu_read_lock() */ +static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t) +{ + struct ip6_tnl_parm *p = &t->parms; + int ret = 0; + struct net *net = dev_net(t->dev); + + if (p->flags & IP6_TNL_F_CAP_RCV) { + struct net_device *ldev = NULL; + + if (p->link) + ldev = dev_get_by_index_rcu(net, p->link); + + if ((ipv6_addr_is_multicast(&p->laddr) || + likely(ipv6_chk_addr(net, &p->laddr, ldev, 0))) && + likely(!ipv6_chk_addr(net, &p->raddr, NULL, 0))) + ret = 1; + + } + return ret; +} + +/** + * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally + * @skb: received socket buffer + * @protocol: ethernet protocol ID + * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN + * + * Return: 0 + **/ + +static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol, + __u8 ipproto, + void (*dscp_ecn_decapsulate)(struct ip6_tnl *t, + struct ipv6hdr *ipv6h, + struct sk_buff *skb)) +{ + struct ip6_tnl *t; + struct ipv6hdr *ipv6h = ipv6_hdr(skb); + + rcu_read_lock(); + + if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, + &ipv6h->daddr)) != NULL) { + if (t->parms.proto != ipproto && t->parms.proto != 0) { + rcu_read_unlock(); + goto discard; + } + + if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { + rcu_read_unlock(); + goto discard; + } + + if (!ip6_tnl_rcv_ctl(t)) { + t->dev->stats.rx_dropped++; + rcu_read_unlock(); + goto discard; + } + secpath_reset(skb); + skb->mac_header = skb->network_header; + skb_reset_network_header(skb); + skb->protocol = htons(protocol); + skb->pkt_type = PACKET_HOST; + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); + + skb_tunnel_rx(skb, t->dev); + + dscp_ecn_decapsulate(t, ipv6h, skb); + netif_rx(skb); + rcu_read_unlock(); + return 0; + } + rcu_read_unlock(); + return 1; + +discard: + kfree_skb(skb); + return 0; +} + +static int ip4ip6_rcv(struct sk_buff *skb) +{ + return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP, + ip4ip6_dscp_ecn_decapsulate); +} + +static int ip6ip6_rcv(struct sk_buff *skb) +{ + return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6, + ip6ip6_dscp_ecn_decapsulate); +} + +struct ipv6_tel_txoption { + struct ipv6_txoptions ops; + __u8 dst_opt[8]; +}; + +static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) +{ + memset(opt, 0, sizeof(struct ipv6_tel_txoption)); + + opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; + opt->dst_opt[3] = 1; + opt->dst_opt[4] = encap_limit; + opt->dst_opt[5] = IPV6_TLV_PADN; + opt->dst_opt[6] = 1; + + opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; + opt->ops.opt_nflen = 8; +} + +/** + * ip6_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 +ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) +{ + return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); +} + +static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t) +{ + struct ip6_tnl_parm *p = &t->parms; + int ret = 0; + struct net *net = dev_net(t->dev); + + if (p->flags & IP6_TNL_F_CAP_XMIT) { + struct net_device *ldev = NULL; + + rcu_read_lock(); + if (p->link) + ldev = dev_get_by_index_rcu(net, p->link); + + if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0))) + printk(KERN_WARNING + "%s xmit: Local address not yet configured!\n", + p->name); + else if (!ipv6_addr_is_multicast(&p->raddr) && + unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0))) + printk(KERN_WARNING + "%s xmit: Routing loop! " + "Remote address found on this node!\n", + p->name); + else + ret = 1; + rcu_read_unlock(); + } + return ret; +} +/** + * ip6_tnl_xmit2 - encapsulate packet and send + * @skb: the outgoing socket buffer + * @dev: the outgoing tunnel device + * @dsfield: dscp code for outer header + * @fl: flow of tunneled packet + * @encap_limit: encapsulation limit + * @pmtu: Path MTU is stored if packet is too big + * + * Description: + * Build new header and do some sanity checks on the packet before sending + * it. + * + * Return: + * 0 on success + * -1 fail + * %-EMSGSIZE message too big. return mtu in this case. + **/ + +static int ip6_tnl_xmit2(struct sk_buff *skb, + struct net_device *dev, + __u8 dsfield, + struct flowi *fl, + int encap_limit, + __u32 *pmtu) +{ + struct net *net = dev_net(dev); + struct ip6_tnl *t = netdev_priv(dev); + struct net_device_stats *stats = &t->dev->stats; + struct ipv6hdr *ipv6h = ipv6_hdr(skb); + struct ipv6_tel_txoption opt; + struct dst_entry *dst; + struct net_device *tdev; + int mtu; + unsigned int max_headroom = sizeof(struct ipv6hdr); + u8 proto; + int err = -1; + int pkt_len; + + if ((dst = ip6_tnl_dst_check(t)) != NULL) + dst_hold(dst); + else { + dst = ip6_route_output(net, NULL, fl); + + if (dst->error || xfrm_lookup(net, &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 (encap_limit >= 0) { + max_headroom += 8; + mtu -= 8; + } + if (mtu < IPV6_MIN_MTU) + mtu = IPV6_MIN_MTU; + if (skb_dst(skb)) + skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); + if (skb->len > mtu) { + *pmtu = mtu; + err = -EMSGSIZE; + 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_shared(skb) || + (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { + 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; + } + skb_dst_drop(skb); + skb_dst_set(skb, dst_clone(dst)); + + skb->transport_header = skb->network_header; + + proto = fl->proto; + if (encap_limit >= 0) { + init_tel_txopt(&opt, encap_limit); + ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); + } + skb_push(skb, sizeof(struct ipv6hdr)); + skb_reset_network_header(skb); + ipv6h = ipv6_hdr(skb); + *(__be32*)ipv6h = fl->fl6_flowlabel | htonl(0x60000000); + dsfield = INET_ECN_encapsulate(0, dsfield); + ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); + 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 = ip6_local_out(skb); + + if (net_xmit_eval(err) == 0) { + stats->tx_bytes += pkt_len; + stats->tx_packets++; + } else { + stats->tx_errors++; + stats->tx_aborted_errors++; + } + ip6_tnl_dst_store(t, dst); + return 0; +tx_err_link_failure: + stats->tx_carrier_errors++; + dst_link_failure(skb); +tx_err_dst_release: + dst_release(dst); + return err; +} + +static inline int +ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + struct iphdr *iph = ip_hdr(skb); + int encap_limit = -1; + struct flowi fl; + __u8 dsfield; + __u32 mtu; + int err; + + if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) || + !ip6_tnl_xmit_ctl(t)) + return -1; + + if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) + encap_limit = t->parms.encap_limit; + + memcpy(&fl, &t->fl, sizeof (fl)); + fl.proto = IPPROTO_IPIP; + + dsfield = ipv4_get_dsfield(iph); + + if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) + fl.fl6_flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) + & IPV6_TCLASS_MASK; + + err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); + if (err != 0) { + /* XXX: send ICMP error even if DF is not set. */ + if (err == -EMSGSIZE) + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, + htonl(mtu)); + return -1; + } + + return 0; +} + +static inline int +ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + struct ipv6hdr *ipv6h = ipv6_hdr(skb); + int encap_limit = -1; + __u16 offset; + struct flowi fl; + __u8 dsfield; + __u32 mtu; + int err; + + if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || + !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h)) + return -1; + + offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb)); + if (offset > 0) { + struct ipv6_tlv_tnl_enc_lim *tel; + tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; + if (tel->encap_limit == 0) { + icmpv6_send(skb, ICMPV6_PARAMPROB, + ICMPV6_HDR_FIELD, offset + 2); + return -1; + } + 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)); + fl.proto = IPPROTO_IPV6; + + dsfield = ipv6_get_dsfield(ipv6h); + if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) + fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); + if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) + fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK); + + err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); + if (err != 0) { + if (err == -EMSGSIZE) + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); + return -1; + } + + return 0; +} + +static netdev_tx_t +ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + struct net_device_stats *stats = &t->dev->stats; + int ret; + + switch (skb->protocol) { + case htons(ETH_P_IP): + ret = ip4ip6_tnl_xmit(skb, dev); + break; + case htons(ETH_P_IPV6): + ret = ip6ip6_tnl_xmit(skb, dev); + break; + default: + goto tx_err; + } + + if (ret < 0) + goto tx_err; + + return NETDEV_TX_OK; + +tx_err: + stats->tx_errors++; + stats->tx_dropped++; + kfree_skb(skb); + return NETDEV_TX_OK; +} + +static void ip6_tnl_set_cap(struct ip6_tnl *t) +{ + struct ip6_tnl_parm *p = &t->parms; + int ltype = ipv6_addr_type(&p->laddr); + int rtype = ipv6_addr_type(&p->raddr); + + p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); + + if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && + rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && + !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && + (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { + if (ltype&IPV6_ADDR_UNICAST) + p->flags |= IP6_TNL_F_CAP_XMIT; + if (rtype&IPV6_ADDR_UNICAST) + p->flags |= IP6_TNL_F_CAP_RCV; + } +} + +static void ip6_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) { + int strict = (ipv6_addr_type(&p->raddr) & + (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); + + struct rt6_info *rt = rt6_lookup(dev_net(dev), + &p->raddr, &p->laddr, + p->link, strict); + + 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->dst); + } +} + +/** + * ip6_tnl_change - update the tunnel parameters + * @t: tunnel to be changed + * @p: tunnel configuration parameters + * + * Description: + * ip6_tnl_change() updates the tunnel parameters + **/ + +static int +ip6_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; + t->parms.proto = p->proto; + ip6_tnl_dst_reset(t); + ip6_tnl_link_config(t); + return 0; +} + +/** + * ip6_tnl_ioctl - configure ipv6 tunnels from userspace + * @dev: virtual device associated with tunnel + * @ifr: parameters passed from userspace + * @cmd: command to be performed + * + * Description: + * ip6_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 +ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) +{ + int err = 0; + struct ip6_tnl_parm p; + struct ip6_tnl *t = NULL; + struct net *net = dev_net(dev); + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + switch (cmd) { + case SIOCGETTUNNEL: + if (dev == ip6n->fb_tnl_dev) { + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { + err = -EFAULT; + break; + } + t = ip6_tnl_locate(net, &p, 0); + } + if (t == NULL) + t = netdev_priv(dev); + memcpy(&p, &t->parms, sizeof (p)); + if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { + err = -EFAULT; + } + break; + case SIOCADDTUNNEL: + case SIOCCHGTUNNEL: + err = -EPERM; + if (!capable(CAP_NET_ADMIN)) + break; + err = -EFAULT; + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) + break; + err = -EINVAL; + if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP && + p.proto != 0) + break; + t = ip6_tnl_locate(net, &p, cmd == SIOCADDTUNNEL); + if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { + if (t != NULL) { + if (t->dev != dev) { + err = -EEXIST; + break; + } + } else + t = netdev_priv(dev); + + ip6_tnl_unlink(ip6n, t); + err = ip6_tnl_change(t, &p); + ip6_tnl_link(ip6n, t); + netdev_state_change(dev); + } + 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 (!capable(CAP_NET_ADMIN)) + break; + + if (dev == ip6n->fb_tnl_dev) { + err = -EFAULT; + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) + break; + err = -ENOENT; + if ((t = ip6_tnl_locate(net, &p, 0)) == NULL) + break; + err = -EPERM; + if (t->dev == ip6n->fb_tnl_dev) + break; + dev = t->dev; + } + err = 0; + unregister_netdevice(dev); + break; + default: + err = -EINVAL; + } + return err; +} + +/** + * ip6_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 +ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) +{ + if (new_mtu < IPV6_MIN_MTU) { + return -EINVAL; + } + dev->mtu = new_mtu; + return 0; +} + + +static const struct net_device_ops ip6_tnl_netdev_ops = { + .ndo_uninit = ip6_tnl_dev_uninit, + .ndo_start_xmit = ip6_tnl_xmit, + .ndo_do_ioctl = ip6_tnl_ioctl, + .ndo_change_mtu = ip6_tnl_change_mtu, +}; + +/** + * ip6_tnl_dev_setup - setup virtual tunnel device + * @dev: virtual device associated with tunnel + * + * Description: + * Initialize function pointers and device parameters + **/ + +static void ip6_tnl_dev_setup(struct net_device *dev) +{ + dev->netdev_ops = &ip6_tnl_netdev_ops; + dev->destructor = free_netdev; + + 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); + dev->features |= NETIF_F_NETNS_LOCAL; +} + + +/** + * ip6_tnl_dev_init_gen - general initializer for all tunnel devices + * @dev: virtual device associated with tunnel + **/ + +static inline void +ip6_tnl_dev_init_gen(struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + t->dev = dev; + strcpy(t->parms.name, dev->name); +} + +/** + * ip6_tnl_dev_init - initializer for all non fallback tunnel devices + * @dev: virtual device associated with tunnel + **/ + +static void ip6_tnl_dev_init(struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + ip6_tnl_dev_init_gen(dev); + ip6_tnl_link_config(t); +} + +/** + * ip6_fb_tnl_dev_init - initializer for fallback tunnel device + * @dev: fallback device + * + * Return: 0 + **/ + +static void __net_init ip6_fb_tnl_dev_init(struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + struct net *net = dev_net(dev); + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + ip6_tnl_dev_init_gen(dev); + t->parms.proto = IPPROTO_IPV6; + dev_hold(dev); + ip6n->tnls_wc[0] = t; +} + +static struct xfrm6_tunnel ip4ip6_handler = { + .handler = ip4ip6_rcv, + .err_handler = ip4ip6_err, + .priority = 1, +}; + +static struct xfrm6_tunnel ip6ip6_handler = { + .handler = ip6ip6_rcv, + .err_handler = ip6ip6_err, + .priority = 1, +}; + +static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n) +{ + int h; + struct ip6_tnl *t; + LIST_HEAD(list); + + for (h = 0; h < HASH_SIZE; h++) { + t = ip6n->tnls_r_l[h]; + while (t != NULL) { + unregister_netdevice_queue(t->dev, &list); + t = t->next; + } + } + + t = ip6n->tnls_wc[0]; + unregister_netdevice_queue(t->dev, &list); + unregister_netdevice_many(&list); +} + +static int __net_init ip6_tnl_init_net(struct net *net) +{ + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + int err; + + ip6n->tnls[0] = ip6n->tnls_wc; + ip6n->tnls[1] = ip6n->tnls_r_l; + + err = -ENOMEM; + ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", + ip6_tnl_dev_setup); + + if (!ip6n->fb_tnl_dev) + goto err_alloc_dev; + dev_net_set(ip6n->fb_tnl_dev, net); + + ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev); + + err = register_netdev(ip6n->fb_tnl_dev); + if (err < 0) + goto err_register; + return 0; + +err_register: + free_netdev(ip6n->fb_tnl_dev); +err_alloc_dev: + return err; +} + +static void __net_exit ip6_tnl_exit_net(struct net *net) +{ + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + rtnl_lock(); + ip6_tnl_destroy_tunnels(ip6n); + rtnl_unlock(); +} + +static struct pernet_operations ip6_tnl_net_ops = { + .init = ip6_tnl_init_net, + .exit = ip6_tnl_exit_net, + .id = &ip6_tnl_net_id, + .size = sizeof(struct ip6_tnl_net), +}; + +/** + * ip6_tunnel_init - register protocol and reserve needed resources + * + * Return: 0 on success + **/ + +static int __init ip6_tunnel_init(void) +{ + int err; + + err = register_pernet_device(&ip6_tnl_net_ops); + if (err < 0) + goto out_pernet; + + err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET); + if (err < 0) { + printk(KERN_ERR "ip6_tunnel init: can't register ip4ip6\n"); + goto out_ip4ip6; + } + + err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6); + if (err < 0) { + printk(KERN_ERR "ip6_tunnel init: can't register ip6ip6\n"); + goto out_ip6ip6; + } + + return 0; + +out_ip6ip6: + xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET); +out_ip4ip6: + unregister_pernet_device(&ip6_tnl_net_ops); +out_pernet: + return err; +} + +/** + * ip6_tunnel_cleanup - free resources and unregister protocol + **/ + +static void __exit ip6_tunnel_cleanup(void) +{ + if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) + printk(KERN_INFO "ip6_tunnel close: can't deregister ip4ip6\n"); + + if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) + printk(KERN_INFO "ip6_tunnel close: can't deregister ip6ip6\n"); + + unregister_pernet_device(&ip6_tnl_net_ops); +} + +module_init(ip6_tunnel_init); +module_exit(ip6_tunnel_cleanup); |