diff options
Diffstat (limited to 'net/ipv6/sit.c')
| -rw-r--r-- | net/ipv6/sit.c | 2017 |
1 files changed, 2017 insertions, 0 deletions
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c new file mode 100644 index 000000000..9806bd56b --- /dev/null +++ b/net/ipv6/sit.c @@ -0,0 +1,2017 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT) + * Linux INET6 implementation + * + * Authors: + * Pedro Roque <roque@di.fc.ul.pt> + * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> + * + * Changes: + * Roger Venning <r.venning@telstra.com>: 6to4 support + * Nate Thompson <nate@thebog.net>: 6to4 support + * Fred Templin <fred.l.templin@boeing.com>: isatap support + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/capability.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/in6.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/icmp.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/init.h> +#include <linux/netfilter_ipv4.h> +#include <linux/if_ether.h> + +#include <net/sock.h> +#include <net/snmp.h> + +#include <net/ipv6.h> +#include <net/protocol.h> +#include <net/transp_v6.h> +#include <net/ip6_fib.h> +#include <net/ip6_route.h> +#include <net/ndisc.h> +#include <net/addrconf.h> +#include <net/ip.h> +#include <net/udp.h> +#include <net/icmp.h> +#include <net/ip_tunnels.h> +#include <net/inet_ecn.h> +#include <net/xfrm.h> +#include <net/dsfield.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> + +/* + This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c + + For comments look at net/ipv4/ip_gre.c --ANK + */ + +#define IP6_SIT_HASH_SIZE 16 +#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) + +static bool log_ecn_error = true; +module_param(log_ecn_error, bool, 0644); +MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); + +static int ipip6_tunnel_init(struct net_device *dev); +static void ipip6_tunnel_setup(struct net_device *dev); +static void ipip6_dev_free(struct net_device *dev); +static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, + __be32 *v4dst); +static struct rtnl_link_ops sit_link_ops __read_mostly; + +static unsigned int sit_net_id __read_mostly; +struct sit_net { + struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE]; + struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE]; + struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE]; + struct ip_tunnel __rcu *tunnels_wc[1]; + struct ip_tunnel __rcu **tunnels[4]; + + struct net_device *fb_tunnel_dev; +}; + +static inline struct sit_net *dev_to_sit_net(struct net_device *dev) +{ + struct ip_tunnel *t = netdev_priv(dev); + + return net_generic(t->net, sit_net_id); +} + +/* + * Must be invoked with rcu_read_lock + */ +static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net, + struct net_device *dev, + __be32 remote, __be32 local, + int sifindex) +{ + unsigned int h0 = HASH(remote); + unsigned int h1 = HASH(local); + struct ip_tunnel *t; + struct sit_net *sitn = net_generic(net, sit_net_id); + int ifindex = dev ? dev->ifindex : 0; + + for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) { + if (local == t->parms.iph.saddr && + remote == t->parms.iph.daddr && + (!dev || !t->parms.link || ifindex == t->parms.link || + sifindex == t->parms.link) && + (t->dev->flags & IFF_UP)) + return t; + } + for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) { + if (remote == t->parms.iph.daddr && + (!dev || !t->parms.link || ifindex == t->parms.link || + sifindex == t->parms.link) && + (t->dev->flags & IFF_UP)) + return t; + } + for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) { + if (local == t->parms.iph.saddr && + (!dev || !t->parms.link || ifindex == t->parms.link || + sifindex == t->parms.link) && + (t->dev->flags & IFF_UP)) + return t; + } + t = rcu_dereference(sitn->tunnels_wc[0]); + if (t && (t->dev->flags & IFF_UP)) + return t; + return NULL; +} + +static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn, + struct ip_tunnel_parm *parms) +{ + __be32 remote = parms->iph.daddr; + __be32 local = parms->iph.saddr; + unsigned int h = 0; + int prio = 0; + + if (remote) { + prio |= 2; + h ^= HASH(remote); + } + if (local) { + prio |= 1; + h ^= HASH(local); + } + return &sitn->tunnels[prio][h]; +} + +static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn, + struct ip_tunnel *t) +{ + return __ipip6_bucket(sitn, &t->parms); +} + +static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) +{ + struct ip_tunnel __rcu **tp; + struct ip_tunnel *iter; + + for (tp = ipip6_bucket(sitn, t); + (iter = rtnl_dereference(*tp)) != NULL; + tp = &iter->next) { + if (t == iter) { + rcu_assign_pointer(*tp, t->next); + break; + } + } +} + +static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) +{ + struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t); + + rcu_assign_pointer(t->next, rtnl_dereference(*tp)); + rcu_assign_pointer(*tp, t); +} + +static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) +{ +#ifdef CONFIG_IPV6_SIT_6RD + struct ip_tunnel *t = netdev_priv(dev); + + if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) { + ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0); + t->ip6rd.relay_prefix = 0; + t->ip6rd.prefixlen = 16; + t->ip6rd.relay_prefixlen = 0; + } else { + struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev); + memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd)); + } +#endif +} + +static int ipip6_tunnel_create(struct net_device *dev) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct net *net = dev_net(dev); + struct sit_net *sitn = net_generic(net, sit_net_id); + int err; + + memcpy(dev->dev_addr, &t->parms.iph.saddr, 4); + memcpy(dev->broadcast, &t->parms.iph.daddr, 4); + + if ((__force u16)t->parms.i_flags & SIT_ISATAP) + dev->priv_flags |= IFF_ISATAP; + + dev->rtnl_link_ops = &sit_link_ops; + + err = register_netdevice(dev); + if (err < 0) + goto out; + + ipip6_tunnel_clone_6rd(dev, sitn); + + ipip6_tunnel_link(sitn, t); + return 0; + +out: + return err; +} + +static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, + struct ip_tunnel_parm *parms, int create) +{ + __be32 remote = parms->iph.daddr; + __be32 local = parms->iph.saddr; + struct ip_tunnel *t, *nt; + struct ip_tunnel __rcu **tp; + struct net_device *dev; + char name[IFNAMSIZ]; + struct sit_net *sitn = net_generic(net, sit_net_id); + + for (tp = __ipip6_bucket(sitn, parms); + (t = rtnl_dereference(*tp)) != NULL; + tp = &t->next) { + if (local == t->parms.iph.saddr && + remote == t->parms.iph.daddr && + parms->link == t->parms.link) { + if (create) + return NULL; + else + return t; + } + } + if (!create) + goto failed; + + if (parms->name[0]) { + if (!dev_valid_name(parms->name)) + goto failed; + strlcpy(name, parms->name, IFNAMSIZ); + } else { + strcpy(name, "sit%d"); + } + dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, + ipip6_tunnel_setup); + if (!dev) + return NULL; + + dev_net_set(dev, net); + + nt = netdev_priv(dev); + + nt->parms = *parms; + if (ipip6_tunnel_create(dev) < 0) + goto failed_free; + + return nt; + +failed_free: + free_netdev(dev); +failed: + return NULL; +} + +#define for_each_prl_rcu(start) \ + for (prl = rcu_dereference(start); \ + prl; \ + prl = rcu_dereference(prl->next)) + +static struct ip_tunnel_prl_entry * +__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) +{ + struct ip_tunnel_prl_entry *prl; + + for_each_prl_rcu(t->prl) + if (prl->addr == addr) + break; + return prl; + +} + +static int ipip6_tunnel_get_prl(struct net_device *dev, struct ifreq *ifr) +{ + struct ip_tunnel_prl __user *a = ifr->ifr_ifru.ifru_data; + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_prl kprl, *kp; + struct ip_tunnel_prl_entry *prl; + unsigned int cmax, c = 0, ca, len; + int ret = 0; + + if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) + return -EINVAL; + + if (copy_from_user(&kprl, a, sizeof(kprl))) + return -EFAULT; + cmax = kprl.datalen / sizeof(kprl); + if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) + cmax = 1; + + /* For simple GET or for root users, + * we try harder to allocate. + */ + kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? + kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) : + NULL; + + ca = min(t->prl_count, cmax); + + if (!kp) { + /* We don't try hard to allocate much memory for + * non-root users. + * For root users, retry allocating enough memory for + * the answer. + */ + kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); + if (!kp) { + ret = -ENOMEM; + goto out; + } + } + + rcu_read_lock(); + for_each_prl_rcu(t->prl) { + if (c >= cmax) + break; + if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) + continue; + kp[c].addr = prl->addr; + kp[c].flags = prl->flags; + c++; + if (kprl.addr != htonl(INADDR_ANY)) + break; + } + + rcu_read_unlock(); + + len = sizeof(*kp) * c; + ret = 0; + if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) + ret = -EFAULT; + + kfree(kp); +out: + return ret; +} + +static int +ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) +{ + struct ip_tunnel_prl_entry *p; + int err = 0; + + if (a->addr == htonl(INADDR_ANY)) + return -EINVAL; + + ASSERT_RTNL(); + + for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) { + if (p->addr == a->addr) { + if (chg) { + p->flags = a->flags; + goto out; + } + err = -EEXIST; + goto out; + } + } + + if (chg) { + err = -ENXIO; + goto out; + } + + p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); + if (!p) { + err = -ENOBUFS; + goto out; + } + + p->next = t->prl; + p->addr = a->addr; + p->flags = a->flags; + t->prl_count++; + rcu_assign_pointer(t->prl, p); +out: + return err; +} + +static void prl_list_destroy_rcu(struct rcu_head *head) +{ + struct ip_tunnel_prl_entry *p, *n; + + p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); + do { + n = rcu_dereference_protected(p->next, 1); + kfree(p); + p = n; + } while (p); +} + +static int +ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) +{ + struct ip_tunnel_prl_entry *x; + struct ip_tunnel_prl_entry __rcu **p; + int err = 0; + + ASSERT_RTNL(); + + if (a && a->addr != htonl(INADDR_ANY)) { + for (p = &t->prl; + (x = rtnl_dereference(*p)) != NULL; + p = &x->next) { + if (x->addr == a->addr) { + *p = x->next; + kfree_rcu(x, rcu_head); + t->prl_count--; + goto out; + } + } + err = -ENXIO; + } else { + x = rtnl_dereference(t->prl); + if (x) { + t->prl_count = 0; + call_rcu(&x->rcu_head, prl_list_destroy_rcu); + t->prl = NULL; + } + } +out: + return err; +} + +static int ipip6_tunnel_prl_ctl(struct net_device *dev, struct ifreq *ifr, + int cmd) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_prl prl; + int err; + + if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) + return -EINVAL; + + if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) + return -EFAULT; + + switch (cmd) { + case SIOCDELPRL: + err = ipip6_tunnel_del_prl(t, &prl); + break; + case SIOCADDPRL: + case SIOCCHGPRL: + err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); + break; + } + dst_cache_reset(&t->dst_cache); + netdev_state_change(dev); + return err; +} + +static int +isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t) +{ + struct ip_tunnel_prl_entry *p; + int ok = 1; + + rcu_read_lock(); + p = __ipip6_tunnel_locate_prl(t, iph->saddr); + if (p) { + if (p->flags & PRL_DEFAULT) + skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; + else + skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; + } else { + const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; + + if (ipv6_addr_is_isatap(addr6) && + (addr6->s6_addr32[3] == iph->saddr) && + ipv6_chk_prefix(addr6, t->dev)) + skb->ndisc_nodetype = NDISC_NODETYPE_HOST; + else + ok = 0; + } + rcu_read_unlock(); + return ok; +} + +static void ipip6_tunnel_uninit(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct sit_net *sitn = net_generic(tunnel->net, sit_net_id); + + if (dev == sitn->fb_tunnel_dev) { + RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL); + } else { + ipip6_tunnel_unlink(sitn, tunnel); + ipip6_tunnel_del_prl(tunnel, NULL); + } + dst_cache_reset(&tunnel->dst_cache); + dev_put(dev); +} + +static int ipip6_err(struct sk_buff *skb, u32 info) +{ + const struct iphdr *iph = (const struct iphdr *)skb->data; + const int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + unsigned int data_len = 0; + struct ip_tunnel *t; + int sifindex; + int err; + + switch (type) { + default: + case ICMP_PARAMETERPROB: + return 0; + + case ICMP_DEST_UNREACH: + switch (code) { + case ICMP_SR_FAILED: + /* Impossible event. */ + return 0; + default: + /* All others are translated to HOST_UNREACH. + rfc2003 contains "deep thoughts" about NET_UNREACH, + I believe they are just ether pollution. --ANK + */ + break; + } + break; + case ICMP_TIME_EXCEEDED: + if (code != ICMP_EXC_TTL) + return 0; + data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ + break; + case ICMP_REDIRECT: + break; + } + + err = -ENOENT; + + sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0; + t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, + iph->daddr, iph->saddr, sifindex); + if (!t) + goto out; + + if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { + ipv4_update_pmtu(skb, dev_net(skb->dev), info, + t->parms.link, iph->protocol); + err = 0; + goto out; + } + if (type == ICMP_REDIRECT) { + ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, + iph->protocol); + err = 0; + goto out; + } + + err = 0; + if (__in6_dev_get(skb->dev) && + !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len)) + goto out; + + if (t->parms.iph.daddr == 0) + goto out; + + if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) + goto out; + + if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) + t->err_count++; + else + t->err_count = 1; + t->err_time = jiffies; +out: + return err; +} + +static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr, + const struct in6_addr *v6addr) +{ + __be32 v4embed = 0; + if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed) + return true; + return false; +} + +/* Checks if an address matches an address on the tunnel interface. + * Used to detect the NAT of proto 41 packets and let them pass spoofing test. + * Long story: + * This function is called after we considered the packet as spoofed + * in is_spoofed_6rd. + * We may have a router that is doing NAT for proto 41 packets + * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb + * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd + * function will return true, dropping the packet. + * But, we can still check if is spoofed against the IP + * addresses associated with the interface. + */ +static bool only_dnatted(const struct ip_tunnel *tunnel, + const struct in6_addr *v6dst) +{ + int prefix_len; + +#ifdef CONFIG_IPV6_SIT_6RD + prefix_len = tunnel->ip6rd.prefixlen + 32 + - tunnel->ip6rd.relay_prefixlen; +#else + prefix_len = 48; +#endif + return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev); +} + +/* Returns true if a packet is spoofed */ +static bool packet_is_spoofed(struct sk_buff *skb, + const struct iphdr *iph, + struct ip_tunnel *tunnel) +{ + const struct ipv6hdr *ipv6h; + + if (tunnel->dev->priv_flags & IFF_ISATAP) { + if (!isatap_chksrc(skb, iph, tunnel)) + return true; + + return false; + } + + if (tunnel->dev->flags & IFF_POINTOPOINT) + return false; + + ipv6h = ipv6_hdr(skb); + + if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) { + net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n", + &iph->saddr, &ipv6h->saddr, + &iph->daddr, &ipv6h->daddr); + return true; + } + + if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr))) + return false; + + if (only_dnatted(tunnel, &ipv6h->daddr)) + return false; + + net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n", + &iph->saddr, &ipv6h->saddr, + &iph->daddr, &ipv6h->daddr); + return true; +} + +static int ipip6_rcv(struct sk_buff *skb) +{ + const struct iphdr *iph = ip_hdr(skb); + struct ip_tunnel *tunnel; + int sifindex; + int err; + + sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0; + tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, + iph->saddr, iph->daddr, sifindex); + if (tunnel) { + struct pcpu_sw_netstats *tstats; + + if (tunnel->parms.iph.protocol != IPPROTO_IPV6 && + tunnel->parms.iph.protocol != 0) + goto out; + + skb->mac_header = skb->network_header; + skb_reset_network_header(skb); + IPCB(skb)->flags = 0; + skb->dev = tunnel->dev; + + if (packet_is_spoofed(skb, iph, tunnel)) { + tunnel->dev->stats.rx_errors++; + goto out; + } + + if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6), + !net_eq(tunnel->net, dev_net(tunnel->dev)))) + goto out; + + /* skb can be uncloned in iptunnel_pull_header, so + * old iph is no longer valid + */ + iph = (const struct iphdr *)skb_mac_header(skb); + err = IP_ECN_decapsulate(iph, skb); + if (unlikely(err)) { + if (log_ecn_error) + net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", + &iph->saddr, iph->tos); + if (err > 1) { + ++tunnel->dev->stats.rx_frame_errors; + ++tunnel->dev->stats.rx_errors; + goto out; + } + } + + tstats = this_cpu_ptr(tunnel->dev->tstats); + u64_stats_update_begin(&tstats->syncp); + tstats->rx_packets++; + tstats->rx_bytes += skb->len; + u64_stats_update_end(&tstats->syncp); + + netif_rx(skb); + + return 0; + } + + /* no tunnel matched, let upstream know, ipsec may handle it */ + return 1; +out: + kfree_skb(skb); + return 0; +} + +static const struct tnl_ptk_info ipip_tpi = { + /* no tunnel info required for ipip. */ + .proto = htons(ETH_P_IP), +}; + +#if IS_ENABLED(CONFIG_MPLS) +static const struct tnl_ptk_info mplsip_tpi = { + /* no tunnel info required for mplsip. */ + .proto = htons(ETH_P_MPLS_UC), +}; +#endif + +static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto) +{ + const struct iphdr *iph; + struct ip_tunnel *tunnel; + int sifindex; + + sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0; + + iph = ip_hdr(skb); + tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, + iph->saddr, iph->daddr, sifindex); + if (tunnel) { + const struct tnl_ptk_info *tpi; + + if (tunnel->parms.iph.protocol != ipproto && + tunnel->parms.iph.protocol != 0) + goto drop; + + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto drop; +#if IS_ENABLED(CONFIG_MPLS) + if (ipproto == IPPROTO_MPLS) + tpi = &mplsip_tpi; + else +#endif + tpi = &ipip_tpi; + if (iptunnel_pull_header(skb, 0, tpi->proto, false)) + goto drop; + return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error); + } + + return 1; + +drop: + kfree_skb(skb); + return 0; +} + +static int ipip_rcv(struct sk_buff *skb) +{ + return sit_tunnel_rcv(skb, IPPROTO_IPIP); +} + +#if IS_ENABLED(CONFIG_MPLS) +static int mplsip_rcv(struct sk_buff *skb) +{ + return sit_tunnel_rcv(skb, IPPROTO_MPLS); +} +#endif + +/* + * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function + * stores the embedded IPv4 address in v4dst and returns true. + */ +static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, + __be32 *v4dst) +{ +#ifdef CONFIG_IPV6_SIT_6RD + if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, + tunnel->ip6rd.prefixlen)) { + unsigned int pbw0, pbi0; + int pbi1; + u32 d; + + pbw0 = tunnel->ip6rd.prefixlen >> 5; + pbi0 = tunnel->ip6rd.prefixlen & 0x1f; + + d = tunnel->ip6rd.relay_prefixlen < 32 ? + (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> + tunnel->ip6rd.relay_prefixlen : 0; + + pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; + if (pbi1 > 0) + d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> + (32 - pbi1); + + *v4dst = tunnel->ip6rd.relay_prefix | htonl(d); + return true; + } +#else + if (v6dst->s6_addr16[0] == htons(0x2002)) { + /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ + memcpy(v4dst, &v6dst->s6_addr16[1], 4); + return true; + } +#endif + return false; +} + +static inline __be32 try_6rd(struct ip_tunnel *tunnel, + const struct in6_addr *v6dst) +{ + __be32 dst = 0; + check_6rd(tunnel, v6dst, &dst); + return dst; +} + +/* + * This function assumes it is being called from dev_queue_xmit() + * and that skb is filled properly by that function. + */ + +static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + const struct iphdr *tiph = &tunnel->parms.iph; + const struct ipv6hdr *iph6 = ipv6_hdr(skb); + u8 tos = tunnel->parms.iph.tos; + __be16 df = tiph->frag_off; + struct rtable *rt; /* Route to the other host */ + struct net_device *tdev; /* Device to other host */ + unsigned int max_headroom; /* The extra header space needed */ + __be32 dst = tiph->daddr; + struct flowi4 fl4; + int mtu; + const struct in6_addr *addr6; + int addr_type; + u8 ttl; + u8 protocol = IPPROTO_IPV6; + int t_hlen = tunnel->hlen + sizeof(struct iphdr); + + if (tos == 1) + tos = ipv6_get_dsfield(iph6); + + /* ISATAP (RFC4214) - must come before 6to4 */ + if (dev->priv_flags & IFF_ISATAP) { + struct neighbour *neigh = NULL; + bool do_tx_error = false; + + if (skb_dst(skb)) + neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); + + if (!neigh) { + net_dbg_ratelimited("nexthop == NULL\n"); + goto tx_error; + } + + addr6 = (const struct in6_addr *)&neigh->primary_key; + addr_type = ipv6_addr_type(addr6); + + if ((addr_type & IPV6_ADDR_UNICAST) && + ipv6_addr_is_isatap(addr6)) + dst = addr6->s6_addr32[3]; + else + do_tx_error = true; + + neigh_release(neigh); + if (do_tx_error) + goto tx_error; + } + + if (!dst) + dst = try_6rd(tunnel, &iph6->daddr); + + if (!dst) { + struct neighbour *neigh = NULL; + bool do_tx_error = false; + + if (skb_dst(skb)) + neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); + + if (!neigh) { + net_dbg_ratelimited("nexthop == NULL\n"); + goto tx_error; + } + + addr6 = (const struct in6_addr *)&neigh->primary_key; + addr_type = ipv6_addr_type(addr6); + + if (addr_type == IPV6_ADDR_ANY) { + addr6 = &ipv6_hdr(skb)->daddr; + addr_type = ipv6_addr_type(addr6); + } + + if ((addr_type & IPV6_ADDR_COMPATv4) != 0) + dst = addr6->s6_addr32[3]; + else + do_tx_error = true; + + neigh_release(neigh); + if (do_tx_error) + goto tx_error; + } + + flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark, + RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6, + 0, dst, tiph->saddr, 0, 0, + sock_net_uid(tunnel->net, NULL)); + + rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr); + if (!rt) { + rt = ip_route_output_flow(tunnel->net, &fl4, NULL); + if (IS_ERR(rt)) { + dev->stats.tx_carrier_errors++; + goto tx_error_icmp; + } + dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr); + } + + if (rt->rt_type != RTN_UNICAST) { + ip_rt_put(rt); + dev->stats.tx_carrier_errors++; + goto tx_error_icmp; + } + tdev = rt->dst.dev; + + if (tdev == dev) { + ip_rt_put(rt); + dev->stats.collisions++; + goto tx_error; + } + + if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) { + ip_rt_put(rt); + goto tx_error; + } + + if (df) { + mtu = dst_mtu(&rt->dst) - t_hlen; + + if (mtu < 68) { + dev->stats.collisions++; + ip_rt_put(rt); + goto tx_error; + } + + if (mtu < IPV6_MIN_MTU) { + mtu = IPV6_MIN_MTU; + df = 0; + } + + if (tunnel->parms.iph.daddr) + skb_dst_update_pmtu_no_confirm(skb, mtu); + + if (skb->len > mtu && !skb_is_gso(skb)) { + icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); + ip_rt_put(rt); + goto tx_error; + } + } + + if (tunnel->err_count > 0) { + if (time_before(jiffies, + tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { + tunnel->err_count--; + dst_link_failure(skb); + } else + tunnel->err_count = 0; + } + + /* + * Okay, now see if we can stuff it in the buffer as-is. + */ + max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen; + + if (skb_headroom(skb) < max_headroom || skb_shared(skb) || + (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { + struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); + if (!new_skb) { + ip_rt_put(rt); + dev->stats.tx_dropped++; + kfree_skb(skb); + return NETDEV_TX_OK; + } + if (skb->sk) + skb_set_owner_w(new_skb, skb->sk); + dev_kfree_skb(skb); + skb = new_skb; + iph6 = ipv6_hdr(skb); + } + ttl = tiph->ttl; + if (ttl == 0) + ttl = iph6->hop_limit; + tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); + + if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) { + ip_rt_put(rt); + goto tx_error; + } + + skb_set_inner_ipproto(skb, IPPROTO_IPV6); + + iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, + df, !net_eq(tunnel->net, dev_net(dev))); + return NETDEV_TX_OK; + +tx_error_icmp: + dst_link_failure(skb); +tx_error: + kfree_skb(skb); + dev->stats.tx_errors++; + return NETDEV_TX_OK; +} + +static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb, + struct net_device *dev, u8 ipproto) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + const struct iphdr *tiph = &tunnel->parms.iph; + + if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) + goto tx_error; + + skb_set_inner_ipproto(skb, ipproto); + + ip_tunnel_xmit(skb, dev, tiph, ipproto); + return NETDEV_TX_OK; +tx_error: + kfree_skb(skb); + dev->stats.tx_errors++; + return NETDEV_TX_OK; +} + +static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + if (!pskb_inet_may_pull(skb)) + goto tx_err; + + switch (skb->protocol) { + case htons(ETH_P_IP): + sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP); + break; + case htons(ETH_P_IPV6): + ipip6_tunnel_xmit(skb, dev); + break; +#if IS_ENABLED(CONFIG_MPLS) + case htons(ETH_P_MPLS_UC): + sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS); + break; +#endif + default: + goto tx_err; + } + + return NETDEV_TX_OK; + +tx_err: + dev->stats.tx_errors++; + kfree_skb(skb); + return NETDEV_TX_OK; + +} + +static void ipip6_tunnel_bind_dev(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + int t_hlen = tunnel->hlen + sizeof(struct iphdr); + struct net_device *tdev = NULL; + int hlen = LL_MAX_HEADER; + const struct iphdr *iph; + struct flowi4 fl4; + + iph = &tunnel->parms.iph; + + if (iph->daddr) { + struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4, + NULL, + iph->daddr, iph->saddr, + 0, 0, + IPPROTO_IPV6, + RT_TOS(iph->tos), + tunnel->parms.link); + + if (!IS_ERR(rt)) { + tdev = rt->dst.dev; + ip_rt_put(rt); + } + dev->flags |= IFF_POINTOPOINT; + } + + if (!tdev && tunnel->parms.link) + tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); + + if (tdev && !netif_is_l3_master(tdev)) { + int mtu; + + mtu = tdev->mtu - t_hlen; + if (mtu < IPV6_MIN_MTU) + mtu = IPV6_MIN_MTU; + WRITE_ONCE(dev->mtu, mtu); + hlen = tdev->hard_header_len + tdev->needed_headroom; + } + dev->needed_headroom = t_hlen + hlen; +} + +static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p, + __u32 fwmark) +{ + struct net *net = t->net; + struct sit_net *sitn = net_generic(net, sit_net_id); + + ipip6_tunnel_unlink(sitn, t); + synchronize_net(); + t->parms.iph.saddr = p->iph.saddr; + t->parms.iph.daddr = p->iph.daddr; + memcpy(t->dev->dev_addr, &p->iph.saddr, 4); + memcpy(t->dev->broadcast, &p->iph.daddr, 4); + ipip6_tunnel_link(sitn, t); + t->parms.iph.ttl = p->iph.ttl; + t->parms.iph.tos = p->iph.tos; + t->parms.iph.frag_off = p->iph.frag_off; + if (t->parms.link != p->link || t->fwmark != fwmark) { + t->parms.link = p->link; + t->fwmark = fwmark; + ipip6_tunnel_bind_dev(t->dev); + } + dst_cache_reset(&t->dst_cache); + netdev_state_change(t->dev); +} + +#ifdef CONFIG_IPV6_SIT_6RD +static int ipip6_tunnel_update_6rd(struct ip_tunnel *t, + struct ip_tunnel_6rd *ip6rd) +{ + struct in6_addr prefix; + __be32 relay_prefix; + + if (ip6rd->relay_prefixlen > 32 || + ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64) + return -EINVAL; + + ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen); + if (!ipv6_addr_equal(&prefix, &ip6rd->prefix)) + return -EINVAL; + if (ip6rd->relay_prefixlen) + relay_prefix = ip6rd->relay_prefix & + htonl(0xffffffffUL << + (32 - ip6rd->relay_prefixlen)); + else + relay_prefix = 0; + if (relay_prefix != ip6rd->relay_prefix) + return -EINVAL; + + t->ip6rd.prefix = prefix; + t->ip6rd.relay_prefix = relay_prefix; + t->ip6rd.prefixlen = ip6rd->prefixlen; + t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen; + dst_cache_reset(&t->dst_cache); + netdev_state_change(t->dev); + return 0; +} + +static int +ipip6_tunnel_get6rd(struct net_device *dev, struct ifreq *ifr) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_6rd ip6rd; + struct ip_tunnel_parm p; + + if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) { + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) + return -EFAULT; + t = ipip6_tunnel_locate(t->net, &p, 0); + } + if (!t) + t = netdev_priv(dev); + + ip6rd.prefix = t->ip6rd.prefix; + ip6rd.relay_prefix = t->ip6rd.relay_prefix; + ip6rd.prefixlen = t->ip6rd.prefixlen; + ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; + if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, sizeof(ip6rd))) + return -EFAULT; + return 0; +} + +static int +ipip6_tunnel_6rdctl(struct net_device *dev, struct ifreq *ifr, int cmd) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_6rd ip6rd; + int err; + + if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, sizeof(ip6rd))) + return -EFAULT; + + if (cmd != SIOCDEL6RD) { + err = ipip6_tunnel_update_6rd(t, &ip6rd); + if (err < 0) + return err; + } else + ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev)); + return 0; +} + +#endif /* CONFIG_IPV6_SIT_6RD */ + +static bool ipip6_valid_ip_proto(u8 ipproto) +{ + return ipproto == IPPROTO_IPV6 || + ipproto == IPPROTO_IPIP || +#if IS_ENABLED(CONFIG_MPLS) + ipproto == IPPROTO_MPLS || +#endif + ipproto == 0; +} + +static int +__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p) +{ + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + if (!ipip6_valid_ip_proto(p->iph.protocol)) + return -EINVAL; + if (p->iph.version != 4 || + p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF))) + return -EINVAL; + + if (p->iph.ttl) + p->iph.frag_off |= htons(IP_DF); + return 0; +} + +static int +ipip6_tunnel_get(struct net_device *dev, struct ip_tunnel_parm *p) +{ + struct ip_tunnel *t = netdev_priv(dev); + + if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) + t = ipip6_tunnel_locate(t->net, p, 0); + if (!t) + t = netdev_priv(dev); + memcpy(p, &t->parms, sizeof(*p)); + return 0; +} + +static int +ipip6_tunnel_add(struct net_device *dev, struct ip_tunnel_parm *p) +{ + struct ip_tunnel *t = netdev_priv(dev); + int err; + + err = __ipip6_tunnel_ioctl_validate(t->net, p); + if (err) + return err; + + t = ipip6_tunnel_locate(t->net, p, 1); + if (!t) + return -ENOBUFS; + return 0; +} + +static int +ipip6_tunnel_change(struct net_device *dev, struct ip_tunnel_parm *p) +{ + struct ip_tunnel *t = netdev_priv(dev); + int err; + + err = __ipip6_tunnel_ioctl_validate(t->net, p); + if (err) + return err; + + t = ipip6_tunnel_locate(t->net, p, 0); + if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) { + if (!t) + return -ENOENT; + } else { + if (t) { + if (t->dev != dev) + return -EEXIST; + } else { + if (((dev->flags & IFF_POINTOPOINT) && !p->iph.daddr) || + (!(dev->flags & IFF_POINTOPOINT) && p->iph.daddr)) + return -EINVAL; + t = netdev_priv(dev); + } + + ipip6_tunnel_update(t, p, t->fwmark); + } + + return 0; +} + +static int +ipip6_tunnel_del(struct net_device *dev, struct ip_tunnel_parm *p) +{ + struct ip_tunnel *t = netdev_priv(dev); + + if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) { + t = ipip6_tunnel_locate(t->net, p, 0); + if (!t) + return -ENOENT; + if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev)) + return -EPERM; + dev = t->dev; + } + unregister_netdevice(dev); + return 0; +} + +static int +ipip6_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) +{ + switch (cmd) { + case SIOCGETTUNNEL: + return ipip6_tunnel_get(dev, p); + case SIOCADDTUNNEL: + return ipip6_tunnel_add(dev, p); + case SIOCCHGTUNNEL: + return ipip6_tunnel_change(dev, p); + case SIOCDELTUNNEL: + return ipip6_tunnel_del(dev, p); + default: + return -EINVAL; + } +} + +static int +ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) +{ + switch (cmd) { + case SIOCGETTUNNEL: + case SIOCADDTUNNEL: + case SIOCCHGTUNNEL: + case SIOCDELTUNNEL: + return ip_tunnel_ioctl(dev, ifr, cmd); + case SIOCGETPRL: + return ipip6_tunnel_get_prl(dev, ifr); + case SIOCADDPRL: + case SIOCDELPRL: + case SIOCCHGPRL: + return ipip6_tunnel_prl_ctl(dev, ifr, cmd); +#ifdef CONFIG_IPV6_SIT_6RD + case SIOCGET6RD: + return ipip6_tunnel_get6rd(dev, ifr); + case SIOCADD6RD: + case SIOCCHG6RD: + case SIOCDEL6RD: + return ipip6_tunnel_6rdctl(dev, ifr, cmd); +#endif + default: + return -EINVAL; + } +} + +static const struct net_device_ops ipip6_netdev_ops = { + .ndo_init = ipip6_tunnel_init, + .ndo_uninit = ipip6_tunnel_uninit, + .ndo_start_xmit = sit_tunnel_xmit, + .ndo_do_ioctl = ipip6_tunnel_ioctl, + .ndo_get_stats64 = ip_tunnel_get_stats64, + .ndo_get_iflink = ip_tunnel_get_iflink, + .ndo_tunnel_ctl = ipip6_tunnel_ctl, +}; + +static void ipip6_dev_free(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + + dst_cache_destroy(&tunnel->dst_cache); + free_percpu(dev->tstats); +} + +#define SIT_FEATURES (NETIF_F_SG | \ + NETIF_F_FRAGLIST | \ + NETIF_F_HIGHDMA | \ + NETIF_F_GSO_SOFTWARE | \ + NETIF_F_HW_CSUM) + +static void ipip6_tunnel_setup(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + int t_hlen = tunnel->hlen + sizeof(struct iphdr); + + dev->netdev_ops = &ipip6_netdev_ops; + dev->header_ops = &ip_tunnel_header_ops; + dev->needs_free_netdev = true; + dev->priv_destructor = ipip6_dev_free; + + dev->type = ARPHRD_SIT; + dev->mtu = ETH_DATA_LEN - t_hlen; + dev->min_mtu = IPV6_MIN_MTU; + dev->max_mtu = IP6_MAX_MTU - t_hlen; + dev->flags = IFF_NOARP; + netif_keep_dst(dev); + dev->addr_len = 4; + dev->features |= NETIF_F_LLTX; + dev->features |= SIT_FEATURES; + dev->hw_features |= SIT_FEATURES; +} + +static int ipip6_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + int err; + + tunnel->dev = dev; + tunnel->net = dev_net(dev); + strcpy(tunnel->parms.name, dev->name); + + ipip6_tunnel_bind_dev(dev); + dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); + if (!dev->tstats) + return -ENOMEM; + + err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL); + if (err) { + free_percpu(dev->tstats); + dev->tstats = NULL; + return err; + } + dev_hold(dev); + return 0; +} + +static void __net_init ipip6_fb_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct iphdr *iph = &tunnel->parms.iph; + struct net *net = dev_net(dev); + struct sit_net *sitn = net_generic(net, sit_net_id); + + iph->version = 4; + iph->protocol = IPPROTO_IPV6; + iph->ihl = 5; + iph->ttl = 64; + + rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); +} + +static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + u8 proto; + + if (!data || !data[IFLA_IPTUN_PROTO]) + return 0; + + proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); + if (!ipip6_valid_ip_proto(proto)) + return -EINVAL; + + return 0; +} + +static void ipip6_netlink_parms(struct nlattr *data[], + struct ip_tunnel_parm *parms, + __u32 *fwmark) +{ + memset(parms, 0, sizeof(*parms)); + + parms->iph.version = 4; + parms->iph.protocol = IPPROTO_IPV6; + parms->iph.ihl = 5; + parms->iph.ttl = 64; + + if (!data) + return; + + if (data[IFLA_IPTUN_LINK]) + parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); + + if (data[IFLA_IPTUN_LOCAL]) + parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]); + + if (data[IFLA_IPTUN_REMOTE]) + parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]); + + if (data[IFLA_IPTUN_TTL]) { + parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]); + if (parms->iph.ttl) + parms->iph.frag_off = htons(IP_DF); + } + + if (data[IFLA_IPTUN_TOS]) + parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]); + + if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC])) + parms->iph.frag_off = htons(IP_DF); + + if (data[IFLA_IPTUN_FLAGS]) + parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]); + + if (data[IFLA_IPTUN_PROTO]) + parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]); + + if (data[IFLA_IPTUN_FWMARK]) + *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]); +} + +/* This function returns true when ENCAP attributes are present in the nl msg */ +static bool ipip6_netlink_encap_parms(struct nlattr *data[], + struct ip_tunnel_encap *ipencap) +{ + bool ret = false; + + memset(ipencap, 0, sizeof(*ipencap)); + + if (!data) + return ret; + + if (data[IFLA_IPTUN_ENCAP_TYPE]) { + ret = true; + ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]); + } + + if (data[IFLA_IPTUN_ENCAP_FLAGS]) { + ret = true; + ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]); + } + + if (data[IFLA_IPTUN_ENCAP_SPORT]) { + ret = true; + ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]); + } + + if (data[IFLA_IPTUN_ENCAP_DPORT]) { + ret = true; + ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]); + } + + return ret; +} + +#ifdef CONFIG_IPV6_SIT_6RD +/* This function returns true when 6RD attributes are present in the nl msg */ +static bool ipip6_netlink_6rd_parms(struct nlattr *data[], + struct ip_tunnel_6rd *ip6rd) +{ + bool ret = false; + memset(ip6rd, 0, sizeof(*ip6rd)); + + if (!data) + return ret; + + if (data[IFLA_IPTUN_6RD_PREFIX]) { + ret = true; + ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]); + } + + if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) { + ret = true; + ip6rd->relay_prefix = + nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]); + } + + if (data[IFLA_IPTUN_6RD_PREFIXLEN]) { + ret = true; + ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]); + } + + if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) { + ret = true; + ip6rd->relay_prefixlen = + nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]); + } + + return ret; +} +#endif + +static int ipip6_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct net *net = dev_net(dev); + struct ip_tunnel *nt; + struct ip_tunnel_encap ipencap; +#ifdef CONFIG_IPV6_SIT_6RD + struct ip_tunnel_6rd ip6rd; +#endif + int err; + + nt = netdev_priv(dev); + + if (ipip6_netlink_encap_parms(data, &ipencap)) { + err = ip_tunnel_encap_setup(nt, &ipencap); + if (err < 0) + return err; + } + + ipip6_netlink_parms(data, &nt->parms, &nt->fwmark); + + if (ipip6_tunnel_locate(net, &nt->parms, 0)) + return -EEXIST; + + err = ipip6_tunnel_create(dev); + if (err < 0) + return err; + + if (tb[IFLA_MTU]) { + u32 mtu = nla_get_u32(tb[IFLA_MTU]); + + if (mtu >= IPV6_MIN_MTU && + mtu <= IP6_MAX_MTU - dev->hard_header_len) + dev->mtu = mtu; + } + +#ifdef CONFIG_IPV6_SIT_6RD + if (ipip6_netlink_6rd_parms(data, &ip6rd)) { + err = ipip6_tunnel_update_6rd(nt, &ip6rd); + if (err < 0) + unregister_netdevice_queue(dev, NULL); + } +#endif + + return err; +} + +static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[], + struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct ip_tunnel *t = netdev_priv(dev); + struct ip_tunnel_parm p; + struct ip_tunnel_encap ipencap; + struct net *net = t->net; + struct sit_net *sitn = net_generic(net, sit_net_id); +#ifdef CONFIG_IPV6_SIT_6RD + struct ip_tunnel_6rd ip6rd; +#endif + __u32 fwmark = t->fwmark; + int err; + + if (dev == sitn->fb_tunnel_dev) + return -EINVAL; + + if (ipip6_netlink_encap_parms(data, &ipencap)) { + err = ip_tunnel_encap_setup(t, &ipencap); + if (err < 0) + return err; + } + + ipip6_netlink_parms(data, &p, &fwmark); + + if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || + (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) + return -EINVAL; + + t = ipip6_tunnel_locate(net, &p, 0); + + if (t) { + if (t->dev != dev) + return -EEXIST; + } else + t = netdev_priv(dev); + + ipip6_tunnel_update(t, &p, fwmark); + +#ifdef CONFIG_IPV6_SIT_6RD + if (ipip6_netlink_6rd_parms(data, &ip6rd)) + return ipip6_tunnel_update_6rd(t, &ip6rd); +#endif + + return 0; +} + +static size_t ipip6_get_size(const struct net_device *dev) +{ + return + /* IFLA_IPTUN_LINK */ + nla_total_size(4) + + /* IFLA_IPTUN_LOCAL */ + nla_total_size(4) + + /* IFLA_IPTUN_REMOTE */ + nla_total_size(4) + + /* IFLA_IPTUN_TTL */ + nla_total_size(1) + + /* IFLA_IPTUN_TOS */ + nla_total_size(1) + + /* IFLA_IPTUN_PMTUDISC */ + nla_total_size(1) + + /* IFLA_IPTUN_FLAGS */ + nla_total_size(2) + + /* IFLA_IPTUN_PROTO */ + nla_total_size(1) + +#ifdef CONFIG_IPV6_SIT_6RD + /* IFLA_IPTUN_6RD_PREFIX */ + nla_total_size(sizeof(struct in6_addr)) + + /* IFLA_IPTUN_6RD_RELAY_PREFIX */ + nla_total_size(4) + + /* IFLA_IPTUN_6RD_PREFIXLEN */ + nla_total_size(2) + + /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */ + nla_total_size(2) + +#endif + /* IFLA_IPTUN_ENCAP_TYPE */ + nla_total_size(2) + + /* IFLA_IPTUN_ENCAP_FLAGS */ + nla_total_size(2) + + /* IFLA_IPTUN_ENCAP_SPORT */ + nla_total_size(2) + + /* IFLA_IPTUN_ENCAP_DPORT */ + nla_total_size(2) + + /* IFLA_IPTUN_FWMARK */ + nla_total_size(4) + + 0; +} + +static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct ip_tunnel_parm *parm = &tunnel->parms; + + if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || + nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || + nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || + nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || + nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || + nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, + !!(parm->iph.frag_off & htons(IP_DF))) || + nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || + nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) || + nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark)) + goto nla_put_failure; + +#ifdef CONFIG_IPV6_SIT_6RD + if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX, + &tunnel->ip6rd.prefix) || + nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX, + tunnel->ip6rd.relay_prefix) || + nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN, + tunnel->ip6rd.prefixlen) || + nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, + tunnel->ip6rd.relay_prefixlen)) + goto nla_put_failure; +#endif + + if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, + tunnel->encap.type) || + nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, + tunnel->encap.sport) || + nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, + tunnel->encap.dport) || + nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, + tunnel->encap.flags)) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { + [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, + [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, + [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, + [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, + [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, + [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, + [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 }, + [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, +#ifdef CONFIG_IPV6_SIT_6RD + [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) }, + [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 }, + [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 }, + [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 }, +#endif + [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 }, + [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 }, + [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 }, + [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 }, + [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 }, +}; + +static void ipip6_dellink(struct net_device *dev, struct list_head *head) +{ + struct net *net = dev_net(dev); + struct sit_net *sitn = net_generic(net, sit_net_id); + + if (dev != sitn->fb_tunnel_dev) + unregister_netdevice_queue(dev, head); +} + +static struct rtnl_link_ops sit_link_ops __read_mostly = { + .kind = "sit", + .maxtype = IFLA_IPTUN_MAX, + .policy = ipip6_policy, + .priv_size = sizeof(struct ip_tunnel), + .setup = ipip6_tunnel_setup, + .validate = ipip6_validate, + .newlink = ipip6_newlink, + .changelink = ipip6_changelink, + .get_size = ipip6_get_size, + .fill_info = ipip6_fill_info, + .dellink = ipip6_dellink, + .get_link_net = ip_tunnel_get_link_net, +}; + +static struct xfrm_tunnel sit_handler __read_mostly = { + .handler = ipip6_rcv, + .err_handler = ipip6_err, + .priority = 1, +}; + +static struct xfrm_tunnel ipip_handler __read_mostly = { + .handler = ipip_rcv, + .err_handler = ipip6_err, + .priority = 2, +}; + +#if IS_ENABLED(CONFIG_MPLS) +static struct xfrm_tunnel mplsip_handler __read_mostly = { + .handler = mplsip_rcv, + .err_handler = ipip6_err, + .priority = 2, +}; +#endif + +static void __net_exit sit_destroy_tunnels(struct net *net, + struct list_head *head) +{ + struct sit_net *sitn = net_generic(net, sit_net_id); + struct net_device *dev, *aux; + int prio; + + for_each_netdev_safe(net, dev, aux) + if (dev->rtnl_link_ops == &sit_link_ops) + unregister_netdevice_queue(dev, head); + + for (prio = 0; prio < 4; prio++) { + int h; + for (h = 0; h < (prio ? IP6_SIT_HASH_SIZE : 1); h++) { + struct ip_tunnel *t; + + t = rtnl_dereference(sitn->tunnels[prio][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, + head); + t = rtnl_dereference(t->next); + } + } + } +} + +static int __net_init sit_init_net(struct net *net) +{ + struct sit_net *sitn = net_generic(net, sit_net_id); + struct ip_tunnel *t; + int err; + + sitn->tunnels[0] = sitn->tunnels_wc; + sitn->tunnels[1] = sitn->tunnels_l; + sitn->tunnels[2] = sitn->tunnels_r; + sitn->tunnels[3] = sitn->tunnels_r_l; + + if (!net_has_fallback_tunnels(net)) + return 0; + + sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", + NET_NAME_UNKNOWN, + ipip6_tunnel_setup); + if (!sitn->fb_tunnel_dev) { + err = -ENOMEM; + goto err_alloc_dev; + } + dev_net_set(sitn->fb_tunnel_dev, net); + sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops; + /* FB netdevice is special: we have one, and only one per netns. + * Allowing to move it to another netns is clearly unsafe. + */ + sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; + + err = register_netdev(sitn->fb_tunnel_dev); + if (err) + goto err_reg_dev; + + ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); + ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); + + t = netdev_priv(sitn->fb_tunnel_dev); + + strcpy(t->parms.name, sitn->fb_tunnel_dev->name); + return 0; + +err_reg_dev: + free_netdev(sitn->fb_tunnel_dev); +err_alloc_dev: + return err; +} + +static void __net_exit sit_exit_batch_net(struct list_head *net_list) +{ + LIST_HEAD(list); + struct net *net; + + rtnl_lock(); + list_for_each_entry(net, net_list, exit_list) + sit_destroy_tunnels(net, &list); + + unregister_netdevice_many(&list); + rtnl_unlock(); +} + +static struct pernet_operations sit_net_ops = { + .init = sit_init_net, + .exit_batch = sit_exit_batch_net, + .id = &sit_net_id, + .size = sizeof(struct sit_net), +}; + +static void __exit sit_cleanup(void) +{ + rtnl_link_unregister(&sit_link_ops); + xfrm4_tunnel_deregister(&sit_handler, AF_INET6); + xfrm4_tunnel_deregister(&ipip_handler, AF_INET); +#if IS_ENABLED(CONFIG_MPLS) + xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS); +#endif + + unregister_pernet_device(&sit_net_ops); + rcu_barrier(); /* Wait for completion of call_rcu()'s */ +} + +static int __init sit_init(void) +{ + int err; + + pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n"); + + err = register_pernet_device(&sit_net_ops); + if (err < 0) + return err; + err = xfrm4_tunnel_register(&sit_handler, AF_INET6); + if (err < 0) { + pr_info("%s: can't register ip6ip4\n", __func__); + goto xfrm_tunnel_failed; + } + err = xfrm4_tunnel_register(&ipip_handler, AF_INET); + if (err < 0) { + pr_info("%s: can't register ip4ip4\n", __func__); + goto xfrm_tunnel4_failed; + } +#if IS_ENABLED(CONFIG_MPLS) + err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS); + if (err < 0) { + pr_info("%s: can't register mplsip\n", __func__); + goto xfrm_tunnel_mpls_failed; + } +#endif + err = rtnl_link_register(&sit_link_ops); + if (err < 0) + goto rtnl_link_failed; + +out: + return err; + +rtnl_link_failed: +#if IS_ENABLED(CONFIG_MPLS) + xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS); +xfrm_tunnel_mpls_failed: +#endif + xfrm4_tunnel_deregister(&ipip_handler, AF_INET); +xfrm_tunnel4_failed: + xfrm4_tunnel_deregister(&sit_handler, AF_INET6); +xfrm_tunnel_failed: + unregister_pernet_device(&sit_net_ops); + goto out; +} + +module_init(sit_init); +module_exit(sit_cleanup); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_RTNL_LINK("sit"); +MODULE_ALIAS_NETDEV("sit0"); |