diff options
Diffstat (limited to 'net/ipv6/ip6_tunnel.c')
| -rw-r--r-- | net/ipv6/ip6_tunnel.c | 1946 |
1 files changed, 1946 insertions, 0 deletions
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c new file mode 100644 index 000000000..5cafd92c2 --- /dev/null +++ b/net/ipv6/ip6_tunnel.c @@ -0,0 +1,1946 @@ +/* + * 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. + * + */ + +#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/sockios.h> +#include <linux/icmp.h> +#include <linux/if.h> +#include <linux/in.h> +#include <linux/ip.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 <linux/hash.h> +#include <linux/etherdevice.h> + +#include <asm/uaccess.h> +#include <linux/atomic.h> + +#include <net/icmp.h> +#include <net/ip.h> +#include <net/ip_tunnels.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"); +MODULE_ALIAS_RTNL_LINK("ip6tnl"); +MODULE_ALIAS_NETDEV("ip6tnl0"); + +#define HASH_SIZE_SHIFT 5 +#define HASH_SIZE (1 << HASH_SIZE_SHIFT) + +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 u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) +{ + u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); + + return hash_32(hash, HASH_SIZE_SHIFT); +} + +static int ip6_tnl_dev_init(struct net_device *dev); +static void ip6_tnl_dev_setup(struct net_device *dev); +static struct rtnl_link_ops ip6_link_ops __read_mostly; + +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 __rcu *tnls_r_l[HASH_SIZE]; + struct ip6_tnl __rcu *tnls_wc[1]; + struct ip6_tnl __rcu **tnls[2]; +}; + +static struct net_device_stats *ip6_get_stats(struct net_device *dev) +{ + struct pcpu_sw_netstats tmp, sum = { 0 }; + int i; + + for_each_possible_cpu(i) { + unsigned int start; + const struct pcpu_sw_netstats *tstats = + per_cpu_ptr(dev->tstats, i); + + do { + start = u64_stats_fetch_begin_irq(&tstats->syncp); + tmp.rx_packets = tstats->rx_packets; + tmp.rx_bytes = tstats->rx_bytes; + tmp.tx_packets = tstats->tx_packets; + tmp.tx_bytes = tstats->tx_bytes; + } while (u64_stats_fetch_retry_irq(&tstats->syncp, start)); + + sum.rx_packets += tmp.rx_packets; + sum.rx_bytes += tmp.rx_bytes; + sum.tx_packets += tmp.tx_packets; + sum.tx_bytes += tmp.tx_bytes; + } + dev->stats.rx_packets = sum.rx_packets; + dev->stats.rx_bytes = sum.rx_bytes; + dev->stats.tx_packets = sum.tx_packets; + dev->stats.tx_bytes = sum.tx_bytes; + return &dev->stats; +} + +/* + * Locking : hash tables are protected by RCU and RTNL + */ + +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)) { + t->dst_cache = NULL; + dst_release(dst); + return NULL; + } + + return dst; +} +EXPORT_SYMBOL_GPL(ip6_tnl_dst_check); + +void ip6_tnl_dst_reset(struct ip6_tnl *t) +{ + dst_release(t->dst_cache); + t->dst_cache = NULL; +} +EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset); + +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; +} +EXPORT_SYMBOL_GPL(ip6_tnl_dst_store); + +/** + * 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, const struct in6_addr *remote, const struct in6_addr *local) +{ + unsigned int hash = HASH(remote, local); + struct ip6_tnl *t; + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + struct in6_addr any; + + for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) { + if (ipv6_addr_equal(local, &t->parms.laddr) && + ipv6_addr_equal(remote, &t->parms.raddr) && + (t->dev->flags & IFF_UP)) + return t; + } + + memset(&any, 0, sizeof(any)); + hash = HASH(&any, local); + for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) { + if (ipv6_addr_equal(local, &t->parms.laddr) && + (t->dev->flags & IFF_UP)) + return t; + } + + hash = HASH(remote, &any); + for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) { + if (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 __rcu ** +ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p) +{ + const struct in6_addr *remote = &p->raddr; + const struct in6_addr *local = &p->laddr; + unsigned int h = 0; + int prio = 0; + + if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { + prio = 1; + h = HASH(remote, 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 __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms); + + rcu_assign_pointer(t->next , rtnl_dereference(*tp)); + rcu_assign_pointer(*tp, t); +} + +/** + * 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 __rcu **tp; + struct ip6_tnl *iter; + + for (tp = ip6_tnl_bucket(ip6n, &t->parms); + (iter = rtnl_dereference(*tp)) != NULL; + tp = &iter->next) { + if (t == iter) { + rcu_assign_pointer(*tp, t->next); + break; + } + } +} + +static void ip6_dev_free(struct net_device *dev) +{ + free_percpu(dev->tstats); + free_netdev(dev); +} + +static int ip6_tnl_create2(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); + int err; + + t = netdev_priv(dev); + + err = register_netdevice(dev); + if (err < 0) + goto out; + + strcpy(t->parms.name, dev->name); + dev->rtnl_link_ops = &ip6_link_ops; + + dev_hold(dev); + ip6_tnl_link(ip6n, t); + return 0; + +out: + return err; +} + +/** + * 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 error pointer + **/ + +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 = -ENOMEM; + + if (p->name[0]) + strlcpy(name, p->name, IFNAMSIZ); + else + sprintf(name, "ip6tnl%%d"); + + dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, + ip6_tnl_dev_setup); + if (!dev) + goto failed; + + dev_net_set(dev, net); + + t = netdev_priv(dev); + t->parms = *p; + t->net = dev_net(dev); + err = ip6_tnl_create2(dev); + if (err < 0) + goto failed_free; + + return t; + +failed_free: + ip6_dev_free(dev); +failed: + return ERR_PTR(err); +} + +/** + * 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 error pointer + **/ + +static struct ip6_tnl *ip6_tnl_locate(struct net *net, + struct __ip6_tnl_parm *p, int create) +{ + const struct in6_addr *remote = &p->raddr; + const struct in6_addr *local = &p->laddr; + struct ip6_tnl __rcu **tp; + struct ip6_tnl *t; + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + for (tp = ip6_tnl_bucket(ip6n, p); + (t = rtnl_dereference(*tp)) != NULL; + tp = &t->next) { + if (ipv6_addr_equal(local, &t->parms.laddr) && + ipv6_addr_equal(remote, &t->parms.raddr)) { + if (create) + return ERR_PTR(-EEXIST); + + return t; + } + } + if (!create) + return ERR_PTR(-ENODEV); + 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 = t->net; + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + if (dev == ip6n->fb_tnl_dev) + RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); + 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 + **/ + +__u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw) +{ + const struct ipv6hdr *ipv6h = (const 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; +} +EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim); + +/** + * 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) +{ + const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data; + struct ip6_tnl *t; + int rel_msg = 0; + u8 rel_type = ICMPV6_DEST_UNREACH; + u8 rel_code = ICMPV6_ADDR_UNREACH; + u8 tproto; + __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(); + t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr); + if (!t) + goto out; + + tproto = ACCESS_ONCE(t->parms.proto); + if (tproto != ipproto && tproto != 0) + goto out; + + err = 0; + + switch (*type) { + __u32 teli; + struct ipv6_tlv_tnl_enc_lim *tel; + __u32 mtu; + case ICMPV6_DEST_UNREACH: + net_warn_ratelimited("%s: Path to destination invalid or inactive!\n", + t->parms.name); + rel_msg = 1; + break; + case ICMPV6_TIME_EXCEED: + if ((*code) == ICMPV6_EXC_HOPLIMIT) { + net_warn_ratelimited("%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 = ip6_tnl_parse_tlv_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) { + net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n", + t->parms.name); + rel_msg = 1; + } + } else { + net_warn_ratelimited("%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; + + len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len); + if (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; + const struct iphdr *eiph; + struct rtable *rt; + struct flowi4 fl4; + + 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; + case NDISC_REDIRECT: + rel_type = ICMP_REDIRECT; + rel_code = ICMP_REDIR_HOST; + 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 */ + rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, + eiph->saddr, 0, + 0, 0, + IPPROTO_IPIP, RT_TOS(eiph->tos), 0); + if (IS_ERR(rt)) + goto out; + + skb2->dev = rt->dst.dev; + + /* route "incoming" packet */ + if (rt->rt_flags & RTCF_LOCAL) { + ip_rt_put(rt); + rt = NULL; + rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, + eiph->daddr, eiph->saddr, + 0, 0, + IPPROTO_IPIP, + RT_TOS(eiph->tos), 0); + if (IS_ERR(rt) || + rt->dst.dev->type != ARPHRD_TUNNEL) { + if (!IS_ERR(rt)) + ip_rt_put(rt); + goto out; + } + skb_dst_set(skb2, &rt->dst); + } 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), NULL, skb2, rel_info); + } + if (rel_type == ICMP_REDIRECT) + skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2); + + 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->dst.dev) + skb2->dev = rt->dst.dev; + + icmpv6_send(skb2, rel_type, rel_code, rel_info); + + ip6_rt_put(rt); + + kfree_skb(skb2); + } + + return 0; +} + +static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, + const 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); + + return IP6_ECN_decapsulate(ipv6h, skb); +} + +static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, + const 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)); + + return IP6_ECN_decapsulate(ipv6h, skb); +} + +__u32 ip6_tnl_get_cap(struct ip6_tnl *t, + const struct in6_addr *laddr, + const struct in6_addr *raddr) +{ + struct __ip6_tnl_parm *p = &t->parms; + int ltype = ipv6_addr_type(laddr); + int rtype = ipv6_addr_type(raddr); + __u32 flags = 0; + + if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) { + flags = IP6_TNL_F_CAP_PER_PACKET; + } else 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) + flags |= IP6_TNL_F_CAP_XMIT; + if (rtype&IPV6_ADDR_UNICAST) + flags |= IP6_TNL_F_CAP_RCV; + } + return flags; +} +EXPORT_SYMBOL(ip6_tnl_get_cap); + +/* called with rcu_read_lock() */ +int ip6_tnl_rcv_ctl(struct ip6_tnl *t, + const struct in6_addr *laddr, + const struct in6_addr *raddr) +{ + struct __ip6_tnl_parm *p = &t->parms; + int ret = 0; + struct net *net = t->net; + + if ((p->flags & IP6_TNL_F_CAP_RCV) || + ((p->flags & IP6_TNL_F_CAP_PER_PACKET) && + (ip6_tnl_get_cap(t, laddr, raddr) & 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(laddr) || + likely(ipv6_chk_addr(net, laddr, ldev, 0))) && + likely(!ipv6_chk_addr(net, raddr, NULL, 0))) + ret = 1; + } + return ret; +} +EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl); + +/** + * 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, + int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t, + const struct ipv6hdr *ipv6h, + struct sk_buff *skb)) +{ + struct ip6_tnl *t; + const struct ipv6hdr *ipv6h = ipv6_hdr(skb); + u8 tproto; + int err; + + rcu_read_lock(); + t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr); + if (t) { + struct pcpu_sw_netstats *tstats; + + tproto = ACCESS_ONCE(t->parms.proto); + if (tproto != ipproto && tproto != 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, &ipv6h->daddr, &ipv6h->saddr)) { + t->dev->stats.rx_dropped++; + rcu_read_unlock(); + goto discard; + } + skb->mac_header = skb->network_header; + skb_reset_network_header(skb); + skb->protocol = htons(protocol); + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); + + __skb_tunnel_rx(skb, t->dev, t->net); + + err = dscp_ecn_decapsulate(t, ipv6h, skb); + if (unlikely(err)) { + if (log_ecn_error) + net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n", + &ipv6h->saddr, + ipv6_get_dsfield(ipv6h)); + if (err > 1) { + ++t->dev->stats.rx_frame_errors; + ++t->dev->stats.rx_errors; + rcu_read_unlock(); + goto discard; + } + } + + tstats = this_cpu_ptr(t->dev->tstats); + u64_stats_update_begin(&tstats->syncp); + tstats->rx_packets++; + tstats->rx_bytes += skb->len; + u64_stats_update_end(&tstats->syncp); + + 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 bool +ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) +{ + return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); +} + +int ip6_tnl_xmit_ctl(struct ip6_tnl *t, + const struct in6_addr *laddr, + const struct in6_addr *raddr) +{ + struct __ip6_tnl_parm *p = &t->parms; + int ret = 0; + struct net *net = t->net; + + if ((p->flags & IP6_TNL_F_CAP_XMIT) || + ((p->flags & IP6_TNL_F_CAP_PER_PACKET) && + (ip6_tnl_get_cap(t, laddr, raddr) & 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, laddr, ldev, 0))) + pr_warn("%s xmit: Local address not yet configured!\n", + p->name); + else if (!ipv6_addr_is_multicast(raddr) && + unlikely(ipv6_chk_addr(net, raddr, NULL, 0))) + pr_warn("%s xmit: Routing loop! Remote address found on this node!\n", + p->name); + else + ret = 1; + rcu_read_unlock(); + } + return ret; +} +EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl); + +/** + * 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 flowi6 *fl6, + int encap_limit, + __u32 *pmtu) +{ + struct ip6_tnl *t = netdev_priv(dev); + struct net *net = t->net; + struct net_device_stats *stats = &t->dev->stats; + struct ipv6hdr *ipv6h = ipv6_hdr(skb); + struct ipv6_tel_txoption opt; + struct dst_entry *dst = NULL, *ndst = NULL; + struct net_device *tdev; + int mtu; + unsigned int max_headroom = sizeof(struct ipv6hdr); + u8 proto; + int err = -1; + + /* NBMA tunnel */ + if (ipv6_addr_any(&t->parms.raddr)) { + struct in6_addr *addr6; + struct neighbour *neigh; + int addr_type; + + if (!skb_dst(skb)) + goto tx_err_link_failure; + + neigh = dst_neigh_lookup(skb_dst(skb), + &ipv6_hdr(skb)->daddr); + if (!neigh) + goto tx_err_link_failure; + + addr6 = (struct in6_addr *)&neigh->primary_key; + addr_type = ipv6_addr_type(addr6); + + if (addr_type == IPV6_ADDR_ANY) + addr6 = &ipv6_hdr(skb)->daddr; + + memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr)); + neigh_release(neigh); + } else if (!fl6->flowi6_mark) + dst = ip6_tnl_dst_check(t); + + if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr)) + goto tx_err_link_failure; + + if (!dst) { + ndst = ip6_route_output(net, NULL, fl6); + + if (ndst->error) + goto tx_err_link_failure; + ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0); + if (IS_ERR(ndst)) { + err = PTR_ERR(ndst); + ndst = NULL; + goto tx_err_link_failure; + } + dst = ndst; + } + + tdev = dst->dev; + + if (tdev == dev) { + stats->collisions++; + net_warn_ratelimited("%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), NULL, skb, mtu); + if (skb->len > mtu) { + *pmtu = mtu; + err = -EMSGSIZE; + goto tx_err_dst_release; + } + + skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); + + /* + * 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; + + new_skb = skb_realloc_headroom(skb, max_headroom); + if (!new_skb) + goto tx_err_dst_release; + + if (skb->sk) + skb_set_owner_w(new_skb, skb->sk); + consume_skb(skb); + skb = new_skb; + } + if (fl6->flowi6_mark) { + skb_dst_set(skb, dst); + ndst = NULL; + } else { + skb_dst_set_noref(skb, dst); + } + skb->transport_header = skb->network_header; + + proto = fl6->flowi6_proto; + if (encap_limit >= 0) { + init_tel_txopt(&opt, encap_limit); + ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); + } + + if (likely(!skb->encapsulation)) { + skb_reset_inner_headers(skb); + skb->encapsulation = 1; + } + + skb_push(skb, sizeof(struct ipv6hdr)); + skb_reset_network_header(skb); + ipv6h = ipv6_hdr(skb); + ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), + ip6_make_flowlabel(net, skb, fl6->flowlabel, false)); + ipv6h->hop_limit = t->parms.hop_limit; + ipv6h->nexthdr = proto; + ipv6h->saddr = fl6->saddr; + ipv6h->daddr = fl6->daddr; + ip6tunnel_xmit(NULL, skb, dev); + if (ndst) + ip6_tnl_dst_store(t, ndst); + return 0; +tx_err_link_failure: + stats->tx_carrier_errors++; + dst_link_failure(skb); +tx_err_dst_release: + dst_release(ndst); + return err; +} + +static inline int +ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + const struct iphdr *iph = ip_hdr(skb); + int encap_limit = -1; + struct flowi6 fl6; + __u8 dsfield; + __u32 mtu; + u8 tproto; + int err; + + tproto = ACCESS_ONCE(t->parms.proto); + if (tproto != IPPROTO_IPIP && tproto != 0) + return -1; + + if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) + encap_limit = t->parms.encap_limit; + + memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6)); + fl6.flowi6_proto = IPPROTO_IPIP; + + dsfield = ipv4_get_dsfield(iph); + + if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) + fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) + & IPV6_TCLASS_MASK; + if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) + fl6.flowi6_mark = skb->mark; + + err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, 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 flowi6 fl6; + __u8 dsfield; + __u32 mtu; + u8 tproto; + int err; + + tproto = ACCESS_ONCE(t->parms.proto); + if ((tproto != IPPROTO_IPV6 && tproto != 0) || + ip6_tnl_addr_conflict(t, ipv6h)) + return -1; + + offset = ip6_tnl_parse_tlv_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(&fl6, &t->fl.u.ip6, sizeof(fl6)); + fl6.flowi6_proto = IPPROTO_IPV6; + + dsfield = ipv6_get_dsfield(ipv6h); + if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) + fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); + if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL) + fl6.flowlabel |= ip6_flowlabel(ipv6h); + if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) + fl6.flowi6_mark = skb->mark; + + err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, 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_link_config(struct ip6_tnl *t) +{ + struct net_device *dev = t->dev; + struct __ip6_tnl_parm *p = &t->parms; + struct flowi6 *fl6 = &t->fl.u.ip6; + + memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); + memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); + + /* Set up flowi template */ + fl6->saddr = p->laddr; + fl6->daddr = p->raddr; + fl6->flowi6_oif = p->link; + fl6->flowlabel = 0; + + if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) + fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; + if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) + fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; + + p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET); + p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); + + if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) + dev->flags |= IFF_POINTOPOINT; + else + dev->flags &= ~IFF_POINTOPOINT; + + 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(t->net, + &p->raddr, &p->laddr, + p->link, strict); + + if (!rt) + return; + + if (rt->dst.dev) { + dev->hard_header_len = rt->dst.dev->hard_header_len + + sizeof(struct ipv6hdr); + + dev->mtu = rt->dst.dev->mtu - sizeof(struct ipv6hdr); + if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) + dev->mtu -= 8; + + if (dev->mtu < IPV6_MIN_MTU) + dev->mtu = IPV6_MIN_MTU; + } + ip6_rt_put(rt); + } +} + +/** + * 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, const struct __ip6_tnl_parm *p) +{ + t->parms.laddr = p->laddr; + 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; +} + +static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p) +{ + struct net *net = t->net; + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + int err; + + ip6_tnl_unlink(ip6n, t); + synchronize_net(); + err = ip6_tnl_change(t, p); + ip6_tnl_link(ip6n, t); + netdev_state_change(t->dev); + return err; +} + +static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p) +{ + /* for default tnl0 device allow to change only the proto */ + t->parms.proto = p->proto; + netdev_state_change(t->dev); + return 0; +} + +static void +ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u) +{ + p->laddr = u->laddr; + p->raddr = u->raddr; + p->flags = u->flags; + p->hop_limit = u->hop_limit; + p->encap_limit = u->encap_limit; + p->flowinfo = u->flowinfo; + p->link = u->link; + p->proto = u->proto; + memcpy(p->name, u->name, sizeof(u->name)); +} + +static void +ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p) +{ + u->laddr = p->laddr; + u->raddr = p->raddr; + u->flags = p->flags; + u->hop_limit = p->hop_limit; + u->encap_limit = p->encap_limit; + u->flowinfo = p->flowinfo; + u->link = p->link; + u->proto = p->proto; + memcpy(u->name, p->name, sizeof(u->name)); +} + +/** + * 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_parm p1; + struct ip6_tnl *t = netdev_priv(dev); + struct net *net = t->net; + 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; + } + ip6_tnl_parm_from_user(&p1, &p); + t = ip6_tnl_locate(net, &p1, 0); + if (IS_ERR(t)) + t = netdev_priv(dev); + } else { + memset(&p, 0, sizeof(p)); + } + ip6_tnl_parm_to_user(&p, &t->parms); + if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) { + err = -EFAULT; + } + break; + case SIOCADDTUNNEL: + case SIOCCHGTUNNEL: + err = -EPERM; + if (!ns_capable(net->user_ns, 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; + ip6_tnl_parm_from_user(&p1, &p); + t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL); + if (cmd == SIOCCHGTUNNEL) { + if (!IS_ERR(t)) { + if (t->dev != dev) { + err = -EEXIST; + break; + } + } else + t = netdev_priv(dev); + if (dev == ip6n->fb_tnl_dev) + err = ip6_tnl0_update(t, &p1); + else + err = ip6_tnl_update(t, &p1); + } + if (!IS_ERR(t)) { + err = 0; + ip6_tnl_parm_to_user(&p, &t->parms); + if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) + err = -EFAULT; + + } else { + err = PTR_ERR(t); + } + break; + case SIOCDELTUNNEL: + err = -EPERM; + if (!ns_capable(net->user_ns, 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; + ip6_tnl_parm_from_user(&p1, &p); + t = ip6_tnl_locate(net, &p1, 0); + if (IS_ERR(t)) + 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) +{ + struct ip6_tnl *tnl = netdev_priv(dev); + + if (tnl->parms.proto == IPPROTO_IPIP) { + if (new_mtu < 68) + return -EINVAL; + } else { + if (new_mtu < IPV6_MIN_MTU) + return -EINVAL; + } + if (new_mtu > 0xFFF8 - dev->hard_header_len) + return -EINVAL; + dev->mtu = new_mtu; + return 0; +} + +int ip6_tnl_get_iflink(const struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + + return t->parms.link; +} +EXPORT_SYMBOL(ip6_tnl_get_iflink); + +static const struct net_device_ops ip6_tnl_netdev_ops = { + .ndo_init = ip6_tnl_dev_init, + .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, + .ndo_get_stats = ip6_get_stats, + .ndo_get_iflink = ip6_tnl_get_iflink, +}; + + +/** + * 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) +{ + struct ip6_tnl *t; + + dev->netdev_ops = &ip6_tnl_netdev_ops; + dev->destructor = ip6_dev_free; + + dev->type = ARPHRD_TUNNEL6; + dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr); + dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr); + t = netdev_priv(dev); + if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) + dev->mtu -= 8; + dev->flags |= IFF_NOARP; + dev->addr_len = sizeof(struct in6_addr); + netif_keep_dst(dev); + /* This perm addr will be used as interface identifier by IPv6 */ + dev->addr_assign_type = NET_ADDR_RANDOM; + eth_random_addr(dev->perm_addr); +} + + +/** + * ip6_tnl_dev_init_gen - general initializer for all tunnel devices + * @dev: virtual device associated with tunnel + **/ + +static inline int +ip6_tnl_dev_init_gen(struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + + t->dev = dev; + t->net = dev_net(dev); + dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); + if (!dev->tstats) + return -ENOMEM; + return 0; +} + +/** + * ip6_tnl_dev_init - initializer for all non fallback tunnel devices + * @dev: virtual device associated with tunnel + **/ + +static int ip6_tnl_dev_init(struct net_device *dev) +{ + struct ip6_tnl *t = netdev_priv(dev); + int err = ip6_tnl_dev_init_gen(dev); + + if (err) + return err; + ip6_tnl_link_config(t); + return 0; +} + +/** + * ip6_fb_tnl_dev_init - initializer for fallback tunnel device + * @dev: fallback device + * + * Return: 0 + **/ + +static int __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); + + t->parms.proto = IPPROTO_IPV6; + dev_hold(dev); + + rcu_assign_pointer(ip6n->tnls_wc[0], t); + return 0; +} + +static int ip6_tnl_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 ip6_tnl_netlink_parms(struct nlattr *data[], + struct __ip6_tnl_parm *parms) +{ + memset(parms, 0, sizeof(*parms)); + + if (!data) + return; + + if (data[IFLA_IPTUN_LINK]) + parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); + + if (data[IFLA_IPTUN_LOCAL]) + parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]); + + if (data[IFLA_IPTUN_REMOTE]) + parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]); + + if (data[IFLA_IPTUN_TTL]) + parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]); + + if (data[IFLA_IPTUN_ENCAP_LIMIT]) + parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]); + + if (data[IFLA_IPTUN_FLOWINFO]) + parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]); + + if (data[IFLA_IPTUN_FLAGS]) + parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]); + + if (data[IFLA_IPTUN_PROTO]) + parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); +} + +static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[]) +{ + struct net *net = dev_net(dev); + struct ip6_tnl *nt, *t; + + nt = netdev_priv(dev); + ip6_tnl_netlink_parms(data, &nt->parms); + + t = ip6_tnl_locate(net, &nt->parms, 0); + if (!IS_ERR(t)) + return -EEXIST; + + return ip6_tnl_create2(dev); +} + +static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[]) +{ + struct ip6_tnl *t = netdev_priv(dev); + struct __ip6_tnl_parm p; + struct net *net = t->net; + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + if (dev == ip6n->fb_tnl_dev) + return -EINVAL; + + ip6_tnl_netlink_parms(data, &p); + + t = ip6_tnl_locate(net, &p, 0); + if (!IS_ERR(t)) { + if (t->dev != dev) + return -EEXIST; + } else + t = netdev_priv(dev); + + return ip6_tnl_update(t, &p); +} + +static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head) +{ + struct net *net = dev_net(dev); + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + + if (dev != ip6n->fb_tnl_dev) + unregister_netdevice_queue(dev, head); +} + +static size_t ip6_tnl_get_size(const struct net_device *dev) +{ + return + /* IFLA_IPTUN_LINK */ + nla_total_size(4) + + /* IFLA_IPTUN_LOCAL */ + nla_total_size(sizeof(struct in6_addr)) + + /* IFLA_IPTUN_REMOTE */ + nla_total_size(sizeof(struct in6_addr)) + + /* IFLA_IPTUN_TTL */ + nla_total_size(1) + + /* IFLA_IPTUN_ENCAP_LIMIT */ + nla_total_size(1) + + /* IFLA_IPTUN_FLOWINFO */ + nla_total_size(4) + + /* IFLA_IPTUN_FLAGS */ + nla_total_size(4) + + /* IFLA_IPTUN_PROTO */ + nla_total_size(1) + + 0; +} + +static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct ip6_tnl *tunnel = netdev_priv(dev); + struct __ip6_tnl_parm *parm = &tunnel->parms; + + if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || + nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) || + nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) || + nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) || + nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) || + nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) || + nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) || + nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto)) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +struct net *ip6_tnl_get_link_net(const struct net_device *dev) +{ + struct ip6_tnl *tunnel = netdev_priv(dev); + + return tunnel->net; +} +EXPORT_SYMBOL(ip6_tnl_get_link_net); + +static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = { + [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, + [IFLA_IPTUN_LOCAL] = { .len = sizeof(struct in6_addr) }, + [IFLA_IPTUN_REMOTE] = { .len = sizeof(struct in6_addr) }, + [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, + [IFLA_IPTUN_ENCAP_LIMIT] = { .type = NLA_U8 }, + [IFLA_IPTUN_FLOWINFO] = { .type = NLA_U32 }, + [IFLA_IPTUN_FLAGS] = { .type = NLA_U32 }, + [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, +}; + +static struct rtnl_link_ops ip6_link_ops __read_mostly = { + .kind = "ip6tnl", + .maxtype = IFLA_IPTUN_MAX, + .policy = ip6_tnl_policy, + .priv_size = sizeof(struct ip6_tnl), + .setup = ip6_tnl_dev_setup, + .validate = ip6_tnl_validate, + .newlink = ip6_tnl_newlink, + .changelink = ip6_tnl_changelink, + .dellink = ip6_tnl_dellink, + .get_size = ip6_tnl_get_size, + .fill_info = ip6_tnl_fill_info, + .get_link_net = ip6_tnl_get_link_net, +}; + +static struct xfrm6_tunnel ip4ip6_handler __read_mostly = { + .handler = ip4ip6_rcv, + .err_handler = ip4ip6_err, + .priority = 1, +}; + +static struct xfrm6_tunnel ip6ip6_handler __read_mostly = { + .handler = ip6ip6_rcv, + .err_handler = ip6ip6_err, + .priority = 1, +}; + +static void __net_exit ip6_tnl_destroy_tunnels(struct net *net) +{ + struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); + struct net_device *dev, *aux; + int h; + struct ip6_tnl *t; + LIST_HEAD(list); + + for_each_netdev_safe(net, dev, aux) + if (dev->rtnl_link_ops == &ip6_link_ops) + unregister_netdevice_queue(dev, &list); + + for (h = 0; h < HASH_SIZE; h++) { + t = rtnl_dereference(ip6n->tnls_r_l[h]); + while (t) { + /* If dev is in the same netns, it has already + * been added to the list by the previous loop. + */ + if (!net_eq(dev_net(t->dev), net)) + unregister_netdevice_queue(t->dev, &list); + t = rtnl_dereference(t->next); + } + } + + 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); + struct ip6_tnl *t = NULL; + 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", + NET_NAME_UNKNOWN, ip6_tnl_dev_setup); + + if (!ip6n->fb_tnl_dev) + goto err_alloc_dev; + dev_net_set(ip6n->fb_tnl_dev, net); + ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops; + /* FB netdevice is special: we have one, and only one per netns. + * Allowing to move it to another netns is clearly unsafe. + */ + ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL; + + err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev); + if (err < 0) + goto err_register; + + err = register_netdev(ip6n->fb_tnl_dev); + if (err < 0) + goto err_register; + + t = netdev_priv(ip6n->fb_tnl_dev); + + strcpy(t->parms.name, ip6n->fb_tnl_dev->name); + return 0; + +err_register: + ip6_dev_free(ip6n->fb_tnl_dev); +err_alloc_dev: + return err; +} + +static void __net_exit ip6_tnl_exit_net(struct net *net) +{ + rtnl_lock(); + ip6_tnl_destroy_tunnels(net); + 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) { + pr_err("%s: can't register ip4ip6\n", __func__); + goto out_ip4ip6; + } + + err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6); + if (err < 0) { + pr_err("%s: can't register ip6ip6\n", __func__); + goto out_ip6ip6; + } + err = rtnl_link_register(&ip6_link_ops); + if (err < 0) + goto rtnl_link_failed; + + return 0; + +rtnl_link_failed: + xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6); +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) +{ + rtnl_link_unregister(&ip6_link_ops); + if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) + pr_info("%s: can't deregister ip4ip6\n", __func__); + + if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) + pr_info("%s: can't deregister ip6ip6\n", __func__); + + unregister_pernet_device(&ip6_tnl_net_ops); +} + +module_init(ip6_tunnel_init); +module_exit(ip6_tunnel_cleanup); 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