v4.19.13 snapshot.
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
new file mode 100644
index 0000000..e9400ff
--- /dev/null
+++ b/net/ipv6/sit.c
@@ -0,0 +1,1959 @@
+/*
+ * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
+ * Linux INET6 implementation
+ *
+ * Authors:
+ * Pedro Roque <roque@di.fc.ul.pt>
+ * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Changes:
+ * Roger Venning <r.venning@telstra.com>: 6to4 support
+ * Nate Thompson <nate@thebog.net>: 6to4 support
+ * Fred Templin <fred.l.templin@boeing.com>: isatap support
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/in6.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/icmp.h>
+#include <linux/slab.h>
+#include <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;
+};
+
+/*
+ * 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);
+
+ dev_hold(dev);
+
+ ipip6_tunnel_link(sitn, t);
+ return 0;
+
+out:
+ return err;
+}
+
+static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
+ struct ip_tunnel_parm *parms, int create)
+{
+ __be32 remote = parms->iph.daddr;
+ __be32 local = parms->iph.saddr;
+ struct ip_tunnel *t, *nt;
+ struct ip_tunnel __rcu **tp;
+ struct net_device *dev;
+ char name[IFNAMSIZ];
+ struct sit_net *sitn = net_generic(net, sit_net_id);
+
+ for (tp = __ipip6_bucket(sitn, parms);
+ (t = rtnl_dereference(*tp)) != NULL;
+ tp = &t->next) {
+ if (local == t->parms.iph.saddr &&
+ remote == t->parms.iph.daddr &&
+ parms->link == t->parms.link) {
+ if (create)
+ return NULL;
+ else
+ return t;
+ }
+ }
+ if (!create)
+ goto failed;
+
+ if (parms->name[0]) {
+ 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 ip_tunnel *t,
+ struct ip_tunnel_prl __user *a)
+{
+ struct ip_tunnel_prl kprl, *kp;
+ struct ip_tunnel_prl_entry *prl;
+ unsigned int cmax, c = 0, ca, len;
+ int ret = 0;
+
+ if (copy_from_user(&kprl, a, sizeof(kprl)))
+ return -EFAULT;
+ cmax = kprl.datalen / sizeof(kprl);
+ if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
+ cmax = 1;
+
+ /* For simple GET or for root users,
+ * we try harder to allocate.
+ */
+ kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
+ kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) :
+ NULL;
+
+ rcu_read_lock();
+
+ ca = t->prl_count < cmax ? t->prl_count : cmax;
+
+ if (!kp) {
+ /* We don't try hard to allocate much memory for
+ * non-root users.
+ * For root users, retry allocating enough memory for
+ * the answer.
+ */
+ kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
+ if (!kp) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+ c = 0;
+ for_each_prl_rcu(t->prl) {
+ if (c >= cmax)
+ break;
+ if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
+ continue;
+ kp[c].addr = prl->addr;
+ kp[c].flags = prl->flags;
+ c++;
+ if (kprl.addr != htonl(INADDR_ANY))
+ break;
+ }
+out:
+ rcu_read_unlock();
+
+ len = sizeof(*kp) * c;
+ ret = 0;
+ if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
+ ret = -EFAULT;
+
+ kfree(kp);
+
+ return ret;
+}
+
+static int
+ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
+{
+ struct ip_tunnel_prl_entry *p;
+ int err = 0;
+
+ if (a->addr == htonl(INADDR_ANY))
+ return -EINVAL;
+
+ ASSERT_RTNL();
+
+ for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
+ if (p->addr == a->addr) {
+ if (chg) {
+ p->flags = a->flags;
+ goto out;
+ }
+ err = -EEXIST;
+ goto out;
+ }
+ }
+
+ if (chg) {
+ err = -ENXIO;
+ goto out;
+ }
+
+ p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
+ if (!p) {
+ err = -ENOBUFS;
+ goto out;
+ }
+
+ p->next = t->prl;
+ p->addr = a->addr;
+ p->flags = a->flags;
+ t->prl_count++;
+ rcu_assign_pointer(t->prl, p);
+out:
+ return err;
+}
+
+static void prl_list_destroy_rcu(struct rcu_head *head)
+{
+ struct ip_tunnel_prl_entry *p, *n;
+
+ p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
+ do {
+ n = rcu_dereference_protected(p->next, 1);
+ kfree(p);
+ p = n;
+ } while (p);
+}
+
+static int
+ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
+{
+ struct ip_tunnel_prl_entry *x;
+ struct ip_tunnel_prl_entry __rcu **p;
+ int err = 0;
+
+ ASSERT_RTNL();
+
+ if (a && a->addr != htonl(INADDR_ANY)) {
+ for (p = &t->prl;
+ (x = rtnl_dereference(*p)) != NULL;
+ p = &x->next) {
+ if (x->addr == a->addr) {
+ *p = x->next;
+ kfree_rcu(x, rcu_head);
+ t->prl_count--;
+ goto out;
+ }
+ }
+ err = -ENXIO;
+ } else {
+ x = rtnl_dereference(t->prl);
+ if (x) {
+ t->prl_count = 0;
+ call_rcu(&x->rcu_head, prl_list_destroy_rcu);
+ t->prl = NULL;
+ }
+ }
+out:
+ return err;
+}
+
+static int
+isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
+{
+ struct ip_tunnel_prl_entry *p;
+ int ok = 1;
+
+ rcu_read_lock();
+ p = __ipip6_tunnel_locate_prl(t, iph->saddr);
+ if (p) {
+ if (p->flags & PRL_DEFAULT)
+ skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
+ else
+ skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
+ } else {
+ const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
+
+ if (ipv6_addr_is_isatap(addr6) &&
+ (addr6->s6_addr32[3] == iph->saddr) &&
+ ipv6_chk_prefix(addr6, t->dev))
+ skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
+ else
+ ok = 0;
+ }
+ rcu_read_unlock();
+ return ok;
+}
+
+static void ipip6_tunnel_uninit(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
+
+ if (dev == sitn->fb_tunnel_dev) {
+ RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
+ } else {
+ ipip6_tunnel_unlink(sitn, tunnel);
+ ipip6_tunnel_del_prl(tunnel, NULL);
+ }
+ 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, 0, iph->protocol, 0);
+ err = 0;
+ goto out;
+ }
+ if (type == ICMP_REDIRECT) {
+ ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
+ iph->protocol, 0);
+ err = 0;
+ goto out;
+ }
+
+ err = 0;
+ if (!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;
+
+ 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 = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
+ tunnel->ip6rd.relay_prefixlen;
+
+ pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
+ if (pbi1 > 0)
+ d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
+ (32 - pbi1);
+
+ *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
+ return true;
+ }
+#else
+ if (v6dst->s6_addr16[0] == htons(0x2002)) {
+ /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
+ memcpy(v4dst, &v6dst->s6_addr16[1], 4);
+ return true;
+ }
+#endif
+ return false;
+}
+
+static inline __be32 try_6rd(struct ip_tunnel *tunnel,
+ const struct in6_addr *v6dst)
+{
+ __be32 dst = 0;
+ check_6rd(tunnel, v6dst, &dst);
+ return dst;
+}
+
+/*
+ * This function assumes it is being called from dev_queue_xmit()
+ * and that skb is filled properly by that function.
+ */
+
+static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ const struct iphdr *tiph = &tunnel->parms.iph;
+ const struct ipv6hdr *iph6 = ipv6_hdr(skb);
+ u8 tos = tunnel->parms.iph.tos;
+ __be16 df = tiph->frag_off;
+ struct rtable *rt; /* Route to the other host */
+ struct net_device *tdev; /* Device to other host */
+ unsigned int max_headroom; /* The extra header space needed */
+ __be32 dst = tiph->daddr;
+ struct flowi4 fl4;
+ int mtu;
+ const struct in6_addr *addr6;
+ int addr_type;
+ u8 ttl;
+ 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 = ip_route_output_flow(tunnel->net, &fl4, NULL);
+
+ if (IS_ERR(rt)) {
+ dev->stats.tx_carrier_errors++;
+ goto tx_error_icmp;
+ }
+ if (rt->rt_type != RTN_UNICAST) {
+ ip_rt_put(rt);
+ dev->stats.tx_carrier_errors++;
+ goto tx_error_icmp;
+ }
+ tdev = rt->dst.dev;
+
+ if (tdev == dev) {
+ ip_rt_put(rt);
+ dev->stats.collisions++;
+ goto tx_error;
+ }
+
+ if (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(skb, mtu);
+
+ if (skb->len > mtu && !skb_is_gso(skb)) {
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+ ip_rt_put(rt);
+ goto tx_error;
+ }
+ }
+
+ if (tunnel->err_count > 0) {
+ if (time_before(jiffies,
+ tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
+ tunnel->err_count--;
+ dst_link_failure(skb);
+ } else
+ tunnel->err_count = 0;
+ }
+
+ /*
+ * 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)
+{
+ 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 net_device *tdev = NULL;
+ struct ip_tunnel *tunnel;
+ const struct iphdr *iph;
+ struct flowi4 fl4;
+
+ tunnel = netdev_priv(dev);
+ iph = &tunnel->parms.iph;
+
+ if (iph->daddr) {
+ struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
+ NULL,
+ iph->daddr, iph->saddr,
+ 0, 0,
+ IPPROTO_IPV6,
+ RT_TOS(iph->tos),
+ tunnel->parms.link);
+
+ if (!IS_ERR(rt)) {
+ tdev = rt->dst.dev;
+ ip_rt_put(rt);
+ }
+ dev->flags |= IFF_POINTOPOINT;
+ }
+
+ if (!tdev && tunnel->parms.link)
+ tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
+
+ if (tdev) {
+ int t_hlen = tunnel->hlen + sizeof(struct iphdr);
+
+ dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
+ dev->mtu = tdev->mtu - t_hlen;
+ if (dev->mtu < IPV6_MIN_MTU)
+ dev->mtu = IPV6_MIN_MTU;
+ }
+}
+
+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;
+}
+#endif
+
+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(struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ int err = 0;
+ struct ip_tunnel_parm p;
+ struct ip_tunnel_prl prl;
+ struct ip_tunnel *t = netdev_priv(dev);
+ 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
+
+ switch (cmd) {
+ case SIOCGETTUNNEL:
+#ifdef CONFIG_IPV6_SIT_6RD
+ case SIOCGET6RD:
+#endif
+ if (dev == sitn->fb_tunnel_dev) {
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
+ err = -EFAULT;
+ break;
+ }
+ t = ipip6_tunnel_locate(net, &p, 0);
+ if (!t)
+ t = netdev_priv(dev);
+ }
+
+ err = -EFAULT;
+ if (cmd == SIOCGETTUNNEL) {
+ memcpy(&p, &t->parms, sizeof(p));
+ if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
+ sizeof(p)))
+ goto done;
+#ifdef CONFIG_IPV6_SIT_6RD
+ } else {
+ ip6rd.prefix = t->ip6rd.prefix;
+ ip6rd.relay_prefix = t->ip6rd.relay_prefix;
+ ip6rd.prefixlen = t->ip6rd.prefixlen;
+ ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
+ if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
+ sizeof(ip6rd)))
+ goto done;
+#endif
+ }
+ err = 0;
+ break;
+
+ case SIOCADDTUNNEL:
+ case SIOCCHGTUNNEL:
+ err = -EPERM;
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+ goto done;
+
+ err = -EFAULT;
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ goto done;
+
+ err = -EINVAL;
+ if (!ipip6_valid_ip_proto(p.iph.protocol))
+ goto done;
+ if (p.iph.version != 4 ||
+ p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
+ goto done;
+ if (p.iph.ttl)
+ p.iph.frag_off |= htons(IP_DF);
+
+ t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
+
+ if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
+ if (t) {
+ if (t->dev != dev) {
+ err = -EEXIST;
+ break;
+ }
+ } else {
+ if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
+ (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
+ err = -EINVAL;
+ break;
+ }
+ t = netdev_priv(dev);
+ }
+
+ ipip6_tunnel_update(t, &p, t->fwmark);
+ }
+
+ if (t) {
+ err = 0;
+ if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
+ err = -EFAULT;
+ } else
+ err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
+ break;
+
+ case SIOCDELTUNNEL:
+ err = -EPERM;
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+ goto done;
+
+ if (dev == sitn->fb_tunnel_dev) {
+ err = -EFAULT;
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ goto done;
+ err = -ENOENT;
+ t = ipip6_tunnel_locate(net, &p, 0);
+ if (!t)
+ goto done;
+ err = -EPERM;
+ if (t == netdev_priv(sitn->fb_tunnel_dev))
+ goto done;
+ dev = t->dev;
+ }
+ unregister_netdevice(dev);
+ err = 0;
+ break;
+
+ case SIOCGETPRL:
+ err = -EINVAL;
+ if (dev == sitn->fb_tunnel_dev)
+ goto done;
+ err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
+ break;
+
+ case SIOCADDPRL:
+ case SIOCDELPRL:
+ case SIOCCHGPRL:
+ err = -EPERM;
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+ goto done;
+ err = -EINVAL;
+ if (dev == sitn->fb_tunnel_dev)
+ goto done;
+ err = -EFAULT;
+ if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
+ goto done;
+
+ 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);
+ break;
+
+#ifdef CONFIG_IPV6_SIT_6RD
+ case SIOCADD6RD:
+ case SIOCCHG6RD:
+ case SIOCDEL6RD:
+ err = -EPERM;
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+ goto done;
+
+ err = -EFAULT;
+ if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
+ sizeof(ip6rd)))
+ goto done;
+
+ if (cmd != SIOCDEL6RD) {
+ err = ipip6_tunnel_update_6rd(t, &ip6rd);
+ if (err < 0)
+ goto done;
+ } else
+ ipip6_tunnel_clone_6rd(dev, sitn);
+
+ err = 0;
+ break;
+#endif
+
+ default:
+ err = -EINVAL;
+ }
+
+done:
+ return err;
+}
+
+static 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,
+};
+
+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->needs_free_netdev = true;
+ dev->priv_destructor = ipip6_dev_free;
+
+ dev->type = ARPHRD_SIT;
+ dev->hard_header_len = LL_MAX_HEADER + t_hlen;
+ 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;
+ }
+
+ 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;
+
+ dev_hold(dev);
+ 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);
+#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 = 1; prio < 4; prio++) {
+ int h;
+ for (h = 0; h < IP6_SIT_HASH_SIZE; 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:
+ ipip6_dev_free(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");