1 files changed, 680 insertions, 0 deletions

diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
new file mode 100644
index 000000000000..295ca29a23c3
--- /dev/null
+++ b/net/ipv6/ila/ila_xlat.c
@@ -0,0 +1,680 @@
+#include <linux/jhash.h>
+#include <linux/netfilter.h>
+#include <linux/rcupdate.h>
+#include <linux/rhashtable.h>
+#include <linux/vmalloc.h>
+#include <net/genetlink.h>
+#include <net/ila.h>
+#include <net/netns/generic.h>
+#include <uapi/linux/genetlink.h>
+#include "ila.h"
+
+struct ila_xlat_params {
+	struct ila_params ip;
+	__be64 identifier;
+	int ifindex;
+	unsigned int dir;
+};
+
+struct ila_map {
+	struct ila_xlat_params p;
+	struct rhash_head node;
+	struct ila_map __rcu *next;
+	struct rcu_head rcu;
+};
+
+static unsigned int ila_net_id;
+
+struct ila_net {
+	struct rhashtable rhash_table;
+	spinlock_t *locks; /* Bucket locks for entry manipulation */
+	unsigned int locks_mask;
+	bool hooks_registered;
+};
+
+#define	LOCKS_PER_CPU 10
+
+static int alloc_ila_locks(struct ila_net *ilan)
+{
+	unsigned int i, size;
+	unsigned int nr_pcpus = num_possible_cpus();
+
+	nr_pcpus = min_t(unsigned int, nr_pcpus, 32UL);
+	size = roundup_pow_of_two(nr_pcpus * LOCKS_PER_CPU);
+
+	if (sizeof(spinlock_t) != 0) {
+#ifdef CONFIG_NUMA
+		if (size * sizeof(spinlock_t) > PAGE_SIZE)
+			ilan->locks = vmalloc(size * sizeof(spinlock_t));
+		else
+#endif
+		ilan->locks = kmalloc_array(size, sizeof(spinlock_t),
+					    GFP_KERNEL);
+		if (!ilan->locks)
+			return -ENOMEM;
+		for (i = 0; i < size; i++)
+			spin_lock_init(&ilan->locks[i]);
+	}
+	ilan->locks_mask = size - 1;
+
+	return 0;
+}
+
+static u32 hashrnd __read_mostly;
+static __always_inline void __ila_hash_secret_init(void)
+{
+	net_get_random_once(&hashrnd, sizeof(hashrnd));
+}
+
+static inline u32 ila_identifier_hash(__be64 identifier)
+{
+	u32 *v = (u32 *)&identifier;
+
+	return jhash_2words(v[0], v[1], hashrnd);
+}
+
+static inline spinlock_t *ila_get_lock(struct ila_net *ilan, __be64 identifier)
+{
+	return &ilan->locks[ila_identifier_hash(identifier) & ilan->locks_mask];
+}
+
+static inline int ila_cmp_wildcards(struct ila_map *ila, __be64 loc,
+				    int ifindex, unsigned int dir)
+{
+	return (ila->p.ip.locator_match && ila->p.ip.locator_match != loc) ||
+	       (ila->p.ifindex && ila->p.ifindex != ifindex) ||
+	       !(ila->p.dir & dir);
+}
+
+static inline int ila_cmp_params(struct ila_map *ila, struct ila_xlat_params *p)
+{
+	return (ila->p.ip.locator_match != p->ip.locator_match) ||
+	       (ila->p.ifindex != p->ifindex) ||
+	       (ila->p.dir != p->dir);
+}
+
+static int ila_cmpfn(struct rhashtable_compare_arg *arg,
+		     const void *obj)
+{
+	const struct ila_map *ila = obj;
+
+	return (ila->p.identifier != *(__be64 *)arg->key);
+}
+
+static inline int ila_order(struct ila_map *ila)
+{
+	int score = 0;
+
+	if (ila->p.ip.locator_match)
+		score += 1 << 0;
+
+	if (ila->p.ifindex)
+		score += 1 << 1;
+
+	return score;
+}
+
+static const struct rhashtable_params rht_params = {
+	.nelem_hint = 1024,
+	.head_offset = offsetof(struct ila_map, node),
+	.key_offset = offsetof(struct ila_map, p.identifier),
+	.key_len = sizeof(u64), /* identifier */
+	.max_size = 1048576,
+	.min_size = 256,
+	.automatic_shrinking = true,
+	.obj_cmpfn = ila_cmpfn,
+};
+
+static struct genl_family ila_nl_family = {
+	.id		= GENL_ID_GENERATE,
+	.hdrsize	= 0,
+	.name		= ILA_GENL_NAME,
+	.version	= ILA_GENL_VERSION,
+	.maxattr	= ILA_ATTR_MAX,
+	.netnsok	= true,
+	.parallel_ops	= true,
+};
+
+static struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
+	[ILA_ATTR_IDENTIFIER] = { .type = NLA_U64, },
+	[ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
+	[ILA_ATTR_LOCATOR_MATCH] = { .type = NLA_U64, },
+	[ILA_ATTR_IFINDEX] = { .type = NLA_U32, },
+	[ILA_ATTR_DIR] = { .type = NLA_U32, },
+};
+
+static int parse_nl_config(struct genl_info *info,
+			   struct ila_xlat_params *p)
+{
+	memset(p, 0, sizeof(*p));
+
+	if (info->attrs[ILA_ATTR_IDENTIFIER])
+		p->identifier = (__force __be64)nla_get_u64(
+			info->attrs[ILA_ATTR_IDENTIFIER]);
+
+	if (info->attrs[ILA_ATTR_LOCATOR])
+		p->ip.locator = (__force __be64)nla_get_u64(
+			info->attrs[ILA_ATTR_LOCATOR]);
+
+	if (info->attrs[ILA_ATTR_LOCATOR_MATCH])
+		p->ip.locator_match = (__force __be64)nla_get_u64(
+			info->attrs[ILA_ATTR_LOCATOR_MATCH]);
+
+	if (info->attrs[ILA_ATTR_IFINDEX])
+		p->ifindex = nla_get_s32(info->attrs[ILA_ATTR_IFINDEX]);
+
+	if (info->attrs[ILA_ATTR_DIR])
+		p->dir = nla_get_u32(info->attrs[ILA_ATTR_DIR]);
+
+	return 0;
+}
+
+/* Must be called with rcu readlock */
+static inline struct ila_map *ila_lookup_wildcards(__be64 id, __be64 loc,
+						   int ifindex,
+						   unsigned int dir,
+						   struct ila_net *ilan)
+{
+	struct ila_map *ila;
+
+	ila = rhashtable_lookup_fast(&ilan->rhash_table, &id, rht_params);
+	while (ila) {
+		if (!ila_cmp_wildcards(ila, loc, ifindex, dir))
+			return ila;
+		ila = rcu_access_pointer(ila->next);
+	}
+
+	return NULL;
+}
+
+/* Must be called with rcu readlock */
+static inline struct ila_map *ila_lookup_by_params(struct ila_xlat_params *p,
+						   struct ila_net *ilan)
+{
+	struct ila_map *ila;
+
+	ila = rhashtable_lookup_fast(&ilan->rhash_table, &p->identifier,
+				     rht_params);
+	while (ila) {
+		if (!ila_cmp_params(ila, p))
+			return ila;
+		ila = rcu_access_pointer(ila->next);
+	}
+
+	return NULL;
+}
+
+static inline void ila_release(struct ila_map *ila)
+{
+	kfree_rcu(ila, rcu);
+}
+
+static void ila_free_cb(void *ptr, void *arg)
+{
+	struct ila_map *ila = (struct ila_map *)ptr, *next;
+
+	/* Assume rcu_readlock held */
+	while (ila) {
+		next = rcu_access_pointer(ila->next);
+		ila_release(ila);
+		ila = next;
+	}
+}
+
+static int ila_xlat_addr(struct sk_buff *skb, int dir);
+
+static unsigned int
+ila_nf_input(void *priv,
+	     struct sk_buff *skb,
+	     const struct nf_hook_state *state)
+{
+	ila_xlat_addr(skb, ILA_DIR_IN);
+	return NF_ACCEPT;
+}
+
+static struct nf_hook_ops ila_nf_hook_ops[] __read_mostly = {
+	{
+		.hook = ila_nf_input,
+		.pf = NFPROTO_IPV6,
+		.hooknum = NF_INET_PRE_ROUTING,
+		.priority = -1,
+	},
+};
+
+static int ila_add_mapping(struct net *net, struct ila_xlat_params *p)
+{
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+	struct ila_map *ila, *head;
+	spinlock_t *lock = ila_get_lock(ilan, p->identifier);
+	int err = 0, order;
+
+	if (!ilan->hooks_registered) {
+		/* We defer registering net hooks in the namespace until the
+		 * first mapping is added.
+		 */
+		err = nf_register_net_hooks(net, ila_nf_hook_ops,
+					    ARRAY_SIZE(ila_nf_hook_ops));
+		if (err)
+			return err;
+
+		ilan->hooks_registered = true;
+	}
+
+	ila = kzalloc(sizeof(*ila), GFP_KERNEL);
+	if (!ila)
+		return -ENOMEM;
+
+	ila->p = *p;
+
+	if (p->ip.locator_match) {
+		/* Precompute checksum difference for translation since we
+		 * know both the old identifier and the new one.
+		 */
+		ila->p.ip.csum_diff = compute_csum_diff8(
+			(__be32 *)&p->ip.locator_match,
+			(__be32 *)&p->ip.locator);
+	}
+
+	order = ila_order(ila);
+
+	spin_lock(lock);
+
+	head = rhashtable_lookup_fast(&ilan->rhash_table, &p->identifier,
+				      rht_params);
+	if (!head) {
+		/* New entry for the rhash_table */
+		err = rhashtable_lookup_insert_fast(&ilan->rhash_table,
+						    &ila->node, rht_params);
+	} else {
+		struct ila_map *tila = head, *prev = NULL;
+
+		do {
+			if (!ila_cmp_params(tila, p)) {
+				err = -EEXIST;
+				goto out;
+			}
+
+			if (order > ila_order(tila))
+				break;
+
+			prev = tila;
+			tila = rcu_dereference_protected(tila->next,
+				lockdep_is_held(lock));
+		} while (tila);
+
+		if (prev) {
+			/* Insert in sub list of head */
+			RCU_INIT_POINTER(ila->next, tila);
+			rcu_assign_pointer(prev->next, ila);
+		} else {
+			/* Make this ila new head */
+			RCU_INIT_POINTER(ila->next, head);
+			err = rhashtable_replace_fast(&ilan->rhash_table,
+						      &head->node,
+						      &ila->node, rht_params);
+			if (err)
+				goto out;
+		}
+	}
+
+out:
+	spin_unlock(lock);
+
+	if (err)
+		kfree(ila);
+
+	return err;
+}
+
+static int ila_del_mapping(struct net *net, struct ila_xlat_params *p)
+{
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+	struct ila_map *ila, *head, *prev;
+	spinlock_t *lock = ila_get_lock(ilan, p->identifier);
+	int err = -ENOENT;
+
+	spin_lock(lock);
+
+	head = rhashtable_lookup_fast(&ilan->rhash_table,
+				      &p->identifier, rht_params);
+	ila = head;
+
+	prev = NULL;
+
+	while (ila) {
+		if (ila_cmp_params(ila, p)) {
+			prev = ila;
+			ila = rcu_dereference_protected(ila->next,
+							lockdep_is_held(lock));
+			continue;
+		}
+
+		err = 0;
+
+		if (prev) {
+			/* Not head, just delete from list */
+			rcu_assign_pointer(prev->next, ila->next);
+		} else {
+			/* It is the head. If there is something in the
+			 * sublist we need to make a new head.
+			 */
+			head = rcu_dereference_protected(ila->next,
+							 lockdep_is_held(lock));
+			if (head) {
+				/* Put first entry in the sublist into the
+				 * table
+				 */
+				err = rhashtable_replace_fast(
+					&ilan->rhash_table, &ila->node,
+					&head->node, rht_params);
+				if (err)
+					goto out;
+			} else {
+				/* Entry no longer used */
+				err = rhashtable_remove_fast(&ilan->rhash_table,
+							     &ila->node,
+							     rht_params);
+			}
+		}
+
+		ila_release(ila);
+
+		break;
+	}
+
+out:
+	spin_unlock(lock);
+
+	return err;
+}
+
+static int ila_nl_cmd_add_mapping(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct ila_xlat_params p;
+	int err;
+
+	err = parse_nl_config(info, &p);
+	if (err)
+		return err;
+
+	return ila_add_mapping(net, &p);
+}
+
+static int ila_nl_cmd_del_mapping(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct ila_xlat_params p;
+	int err;
+
+	err = parse_nl_config(info, &p);
+	if (err)
+		return err;
+
+	ila_del_mapping(net, &p);
+
+	return 0;
+}
+
+static int ila_fill_info(struct ila_map *ila, struct sk_buff *msg)
+{
+	if (nla_put_u64(msg, ILA_ATTR_IDENTIFIER,
+			(__force u64)ila->p.identifier) ||
+	    nla_put_u64(msg, ILA_ATTR_LOCATOR,
+			(__force u64)ila->p.ip.locator) ||
+	    nla_put_u64(msg, ILA_ATTR_LOCATOR_MATCH,
+			(__force u64)ila->p.ip.locator_match) ||
+	    nla_put_s32(msg, ILA_ATTR_IFINDEX, ila->p.ifindex) ||
+	    nla_put_u32(msg, ILA_ATTR_DIR, ila->p.dir))
+		return -1;
+
+	return 0;
+}
+
+static int ila_dump_info(struct ila_map *ila,
+			 u32 portid, u32 seq, u32 flags,
+			 struct sk_buff *skb, u8 cmd)
+{
+	void *hdr;
+
+	hdr = genlmsg_put(skb, portid, seq, &ila_nl_family, flags, cmd);
+	if (!hdr)
+		return -ENOMEM;
+
+	if (ila_fill_info(ila, skb) < 0)
+		goto nla_put_failure;
+
+	genlmsg_end(skb, hdr);
+	return 0;
+
+nla_put_failure:
+	genlmsg_cancel(skb, hdr);
+	return -EMSGSIZE;
+}
+
+static int ila_nl_cmd_get_mapping(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+	struct sk_buff *msg;
+	struct ila_xlat_params p;
+	struct ila_map *ila;
+	int ret;
+
+	ret = parse_nl_config(info, &p);
+	if (ret)
+		return ret;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	rcu_read_lock();
+
+	ila = ila_lookup_by_params(&p, ilan);
+	if (ila) {
+		ret = ila_dump_info(ila,
+				    info->snd_portid,
+				    info->snd_seq, 0, msg,
+				    info->genlhdr->cmd);
+	}
+
+	rcu_read_unlock();
+
+	if (ret < 0)
+		goto out_free;
+
+	return genlmsg_reply(msg, info);
+
+out_free:
+	nlmsg_free(msg);
+	return ret;
+}
+
+struct ila_dump_iter {
+	struct rhashtable_iter rhiter;
+};
+
+static int ila_nl_dump_start(struct netlink_callback *cb)
+{
+	struct net *net = sock_net(cb->skb->sk);
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+	struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args;
+
+	return rhashtable_walk_init(&ilan->rhash_table, &iter->rhiter);
+}
+
+static int ila_nl_dump_done(struct netlink_callback *cb)
+{
+	struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args;
+
+	rhashtable_walk_exit(&iter->rhiter);
+
+	return 0;
+}
+
+static int ila_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args;
+	struct rhashtable_iter *rhiter = &iter->rhiter;
+	struct ila_map *ila;
+	int ret;
+
+	ret = rhashtable_walk_start(rhiter);
+	if (ret && ret != -EAGAIN)
+		goto done;
+
+	for (;;) {
+		ila = rhashtable_walk_next(rhiter);
+
+		if (IS_ERR(ila)) {
+			if (PTR_ERR(ila) == -EAGAIN)
+				continue;
+			ret = PTR_ERR(ila);
+			goto done;
+		} else if (!ila) {
+			break;
+		}
+
+		while (ila) {
+			ret =  ila_dump_info(ila, NETLINK_CB(cb->skb).portid,
+					     cb->nlh->nlmsg_seq, NLM_F_MULTI,
+					     skb, ILA_CMD_GET);
+			if (ret)
+				goto done;
+
+			ila = rcu_access_pointer(ila->next);
+		}
+	}
+
+	ret = skb->len;
+
+done:
+	rhashtable_walk_stop(rhiter);
+	return ret;
+}
+
+static const struct genl_ops ila_nl_ops[] = {
+	{
+		.cmd = ILA_CMD_ADD,
+		.doit = ila_nl_cmd_add_mapping,
+		.policy = ila_nl_policy,
+		.flags = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd = ILA_CMD_DEL,
+		.doit = ila_nl_cmd_del_mapping,
+		.policy = ila_nl_policy,
+		.flags = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd = ILA_CMD_GET,
+		.doit = ila_nl_cmd_get_mapping,
+		.start = ila_nl_dump_start,
+		.dumpit = ila_nl_dump,
+		.done = ila_nl_dump_done,
+		.policy = ila_nl_policy,
+	},
+};
+
+#define ILA_HASH_TABLE_SIZE 1024
+
+static __net_init int ila_init_net(struct net *net)
+{
+	int err;
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+
+	err = alloc_ila_locks(ilan);
+	if (err)
+		return err;
+
+	rhashtable_init(&ilan->rhash_table, &rht_params);
+
+	return 0;
+}
+
+static __net_exit void ila_exit_net(struct net *net)
+{
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+
+	rhashtable_free_and_destroy(&ilan->rhash_table, ila_free_cb, NULL);
+
+	kvfree(ilan->locks);
+
+	if (ilan->hooks_registered)
+		nf_unregister_net_hooks(net, ila_nf_hook_ops,
+					ARRAY_SIZE(ila_nf_hook_ops));
+}
+
+static struct pernet_operations ila_net_ops = {
+	.init = ila_init_net,
+	.exit = ila_exit_net,
+	.id   = &ila_net_id,
+	.size = sizeof(struct ila_net),
+};
+
+static int ila_xlat_addr(struct sk_buff *skb, int dir)
+{
+	struct ila_map *ila;
+	struct ipv6hdr *ip6h = ipv6_hdr(skb);
+	struct net *net = dev_net(skb->dev);
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+	__be64 identifier, locator_match;
+	size_t nhoff;
+
+	/* Assumes skb contains a valid IPv6 header that is pulled */
+
+	identifier = *(__be64 *)&ip6h->daddr.in6_u.u6_addr8[8];
+	locator_match = *(__be64 *)&ip6h->daddr.in6_u.u6_addr8[0];
+	nhoff = sizeof(struct ipv6hdr);
+
+	rcu_read_lock();
+
+	ila = ila_lookup_wildcards(identifier, locator_match,
+				   skb->dev->ifindex, dir, ilan);
+	if (ila)
+		update_ipv6_locator(skb, &ila->p.ip);
+
+	rcu_read_unlock();
+
+	return 0;
+}
+
+int ila_xlat_incoming(struct sk_buff *skb)
+{
+	return ila_xlat_addr(skb, ILA_DIR_IN);
+}
+EXPORT_SYMBOL(ila_xlat_incoming);
+
+int ila_xlat_outgoing(struct sk_buff *skb)
+{
+	return ila_xlat_addr(skb, ILA_DIR_OUT);
+}
+EXPORT_SYMBOL(ila_xlat_outgoing);
+
+int ila_xlat_init(void)
+{
+	int ret;
+
+	ret = register_pernet_device(&ila_net_ops);
+	if (ret)
+		goto exit;
+
+	ret = genl_register_family_with_ops(&ila_nl_family,
+					    ila_nl_ops);
+	if (ret < 0)
+		goto unregister;
+
+	return 0;
+
+unregister:
+	unregister_pernet_device(&ila_net_ops);
+exit:
+	return ret;
+}
+
+void ila_xlat_fini(void)
+{
+	genl_unregister_family(&ila_nl_family);
+	unregister_pernet_device(&ila_net_ops);
+}