1 files changed, 660 insertions, 0 deletions

diff --git a/net/ipv6/ila/ila_xlat.c b/net/ipv6/ila/ila_xlat.c
new file mode 100644
index 000000000..bee45dfeb
--- /dev/null
+++ b/net/ipv6/ila/ila_xlat.c
@@ -0,0 +1,660 @@
+// SPDX-License-Identifier: GPL-2.0
+#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;
+	int ifindex;
+};
+
+struct ila_map {
+	struct ila_xlat_params xp;
+	struct rhash_head node;
+	struct ila_map __rcu *next;
+	struct rcu_head rcu;
+};
+
+#define MAX_LOCKS 1024
+#define	LOCKS_PER_CPU 10
+
+static int alloc_ila_locks(struct ila_net *ilan)
+{
+	return alloc_bucket_spinlocks(&ilan->xlat.locks, &ilan->xlat.locks_mask,
+				      MAX_LOCKS, LOCKS_PER_CPU,
+				      GFP_KERNEL);
+}
+
+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_locator_hash(struct ila_locator loc)
+{
+	u32 *v = (u32 *)loc.v32;
+
+	__ila_hash_secret_init();
+	return jhash_2words(v[0], v[1], hashrnd);
+}
+
+static inline spinlock_t *ila_get_lock(struct ila_net *ilan,
+				       struct ila_locator loc)
+{
+	return &ilan->xlat.locks[ila_locator_hash(loc) & ilan->xlat.locks_mask];
+}
+
+static inline int ila_cmp_wildcards(struct ila_map *ila,
+				    struct ila_addr *iaddr, int ifindex)
+{
+	return (ila->xp.ifindex && ila->xp.ifindex != ifindex);
+}
+
+static inline int ila_cmp_params(struct ila_map *ila,
+				 struct ila_xlat_params *xp)
+{
+	return (ila->xp.ifindex != xp->ifindex);
+}
+
+static int ila_cmpfn(struct rhashtable_compare_arg *arg,
+		     const void *obj)
+{
+	const struct ila_map *ila = obj;
+
+	return (ila->xp.ip.locator_match.v64 != *(__be64 *)arg->key);
+}
+
+static inline int ila_order(struct ila_map *ila)
+{
+	int score = 0;
+
+	if (ila->xp.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, xp.ip.locator_match),
+	.key_len = sizeof(u64), /* identifier */
+	.max_size = 1048576,
+	.min_size = 256,
+	.automatic_shrinking = true,
+	.obj_cmpfn = ila_cmpfn,
+};
+
+static int parse_nl_config(struct genl_info *info,
+			   struct ila_xlat_params *xp)
+{
+	memset(xp, 0, sizeof(*xp));
+
+	if (info->attrs[ILA_ATTR_LOCATOR])
+		xp->ip.locator.v64 = (__force __be64)nla_get_u64(
+			info->attrs[ILA_ATTR_LOCATOR]);
+
+	if (info->attrs[ILA_ATTR_LOCATOR_MATCH])
+		xp->ip.locator_match.v64 = (__force __be64)nla_get_u64(
+			info->attrs[ILA_ATTR_LOCATOR_MATCH]);
+
+	if (info->attrs[ILA_ATTR_CSUM_MODE])
+		xp->ip.csum_mode = nla_get_u8(info->attrs[ILA_ATTR_CSUM_MODE]);
+	else
+		xp->ip.csum_mode = ILA_CSUM_NO_ACTION;
+
+	if (info->attrs[ILA_ATTR_IDENT_TYPE])
+		xp->ip.ident_type = nla_get_u8(
+				info->attrs[ILA_ATTR_IDENT_TYPE]);
+	else
+		xp->ip.ident_type = ILA_ATYPE_USE_FORMAT;
+
+	if (info->attrs[ILA_ATTR_IFINDEX])
+		xp->ifindex = nla_get_s32(info->attrs[ILA_ATTR_IFINDEX]);
+
+	return 0;
+}
+
+/* Must be called with rcu readlock */
+static inline struct ila_map *ila_lookup_wildcards(struct ila_addr *iaddr,
+						   int ifindex,
+						   struct ila_net *ilan)
+{
+	struct ila_map *ila;
+
+	ila = rhashtable_lookup_fast(&ilan->xlat.rhash_table, &iaddr->loc,
+				     rht_params);
+	while (ila) {
+		if (!ila_cmp_wildcards(ila, iaddr, ifindex))
+			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 *xp,
+						   struct ila_net *ilan)
+{
+	struct ila_map *ila;
+
+	ila = rhashtable_lookup_fast(&ilan->xlat.rhash_table,
+				     &xp->ip.locator_match,
+				     rht_params);
+	while (ila) {
+		if (!ila_cmp_params(ila, xp))
+			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_node(struct ila_map *ila)
+{
+	struct ila_map *next;
+
+	/* Assume rcu_readlock held */
+	while (ila) {
+		next = rcu_access_pointer(ila->next);
+		ila_release(ila);
+		ila = next;
+	}
+}
+
+static void ila_free_cb(void *ptr, void *arg)
+{
+	ila_free_node((struct ila_map *)ptr);
+}
+
+static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila);
+
+static unsigned int
+ila_nf_input(void *priv,
+	     struct sk_buff *skb,
+	     const struct nf_hook_state *state)
+{
+	ila_xlat_addr(skb, false);
+	return NF_ACCEPT;
+}
+
+static const struct nf_hook_ops ila_nf_hook_ops[] = {
+	{
+		.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 *xp)
+{
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+	struct ila_map *ila, *head;
+	spinlock_t *lock = ila_get_lock(ilan, xp->ip.locator_match);
+	int err = 0, order;
+
+	if (!ilan->xlat.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->xlat.hooks_registered = true;
+	}
+
+	ila = kzalloc(sizeof(*ila), GFP_KERNEL);
+	if (!ila)
+		return -ENOMEM;
+
+	ila_init_saved_csum(&xp->ip);
+
+	ila->xp = *xp;
+
+	order = ila_order(ila);
+
+	spin_lock(lock);
+
+	head = rhashtable_lookup_fast(&ilan->xlat.rhash_table,
+				      &xp->ip.locator_match,
+				      rht_params);
+	if (!head) {
+		/* New entry for the rhash_table */
+		err = rhashtable_lookup_insert_fast(&ilan->xlat.rhash_table,
+						    &ila->node, rht_params);
+	} else {
+		struct ila_map *tila = head, *prev = NULL;
+
+		do {
+			if (!ila_cmp_params(tila, xp)) {
+				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->xlat.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 *xp)
+{
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+	struct ila_map *ila, *head, *prev;
+	spinlock_t *lock = ila_get_lock(ilan, xp->ip.locator_match);
+	int err = -ENOENT;
+
+	spin_lock(lock);
+
+	head = rhashtable_lookup_fast(&ilan->xlat.rhash_table,
+				      &xp->ip.locator_match, rht_params);
+	ila = head;
+
+	prev = NULL;
+
+	while (ila) {
+		if (ila_cmp_params(ila, xp)) {
+			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->xlat.rhash_table, &ila->node,
+					&head->node, rht_params);
+				if (err)
+					goto out;
+			} else {
+				/* Entry no longer used */
+				err = rhashtable_remove_fast(
+						&ilan->xlat.rhash_table,
+						&ila->node, rht_params);
+			}
+		}
+
+		ila_release(ila);
+
+		break;
+	}
+
+out:
+	spin_unlock(lock);
+
+	return err;
+}
+
+int ila_xlat_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);
+}
+
+int ila_xlat_nl_cmd_del_mapping(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct ila_xlat_params xp;
+	int err;
+
+	err = parse_nl_config(info, &xp);
+	if (err)
+		return err;
+
+	ila_del_mapping(net, &xp);
+
+	return 0;
+}
+
+static inline spinlock_t *lock_from_ila_map(struct ila_net *ilan,
+					    struct ila_map *ila)
+{
+	return ila_get_lock(ilan, ila->xp.ip.locator_match);
+}
+
+int ila_xlat_nl_cmd_flush(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 rhashtable_iter iter;
+	struct ila_map *ila;
+	spinlock_t *lock;
+	int ret = 0;
+
+	rhashtable_walk_enter(&ilan->xlat.rhash_table, &iter);
+	rhashtable_walk_start(&iter);
+
+	for (;;) {
+		ila = rhashtable_walk_next(&iter);
+
+		if (IS_ERR(ila)) {
+			if (PTR_ERR(ila) == -EAGAIN)
+				continue;
+			ret = PTR_ERR(ila);
+			goto done;
+		} else if (!ila) {
+			break;
+		}
+
+		lock = lock_from_ila_map(ilan, ila);
+
+		spin_lock(lock);
+
+		ret = rhashtable_remove_fast(&ilan->xlat.rhash_table,
+					     &ila->node, rht_params);
+		if (!ret)
+			ila_free_node(ila);
+
+		spin_unlock(lock);
+
+		if (ret)
+			break;
+	}
+
+done:
+	rhashtable_walk_stop(&iter);
+	rhashtable_walk_exit(&iter);
+	return ret;
+}
+
+static int ila_fill_info(struct ila_map *ila, struct sk_buff *msg)
+{
+	if (nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR,
+			      (__force u64)ila->xp.ip.locator.v64,
+			      ILA_ATTR_PAD) ||
+	    nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR_MATCH,
+			      (__force u64)ila->xp.ip.locator_match.v64,
+			      ILA_ATTR_PAD) ||
+	    nla_put_s32(msg, ILA_ATTR_IFINDEX, ila->xp.ifindex) ||
+	    nla_put_u8(msg, ILA_ATTR_CSUM_MODE, ila->xp.ip.csum_mode) ||
+	    nla_put_u8(msg, ILA_ATTR_IDENT_TYPE, ila->xp.ip.ident_type))
+		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;
+}
+
+int ila_xlat_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 xp;
+	struct ila_map *ila;
+	int ret;
+
+	ret = parse_nl_config(info, &xp);
+	if (ret)
+		return ret;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	rcu_read_lock();
+
+	ret = -ESRCH;
+	ila = ila_lookup_by_params(&xp, 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;
+	int skip;
+};
+
+int ila_xlat_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;
+
+	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+	if (!iter)
+		return -ENOMEM;
+
+	rhashtable_walk_enter(&ilan->xlat.rhash_table, &iter->rhiter);
+
+	iter->skip = 0;
+	cb->args[0] = (long)iter;
+
+	return 0;
+}
+
+int ila_xlat_nl_dump_done(struct netlink_callback *cb)
+{
+	struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args[0];
+
+	rhashtable_walk_exit(&iter->rhiter);
+
+	kfree(iter);
+
+	return 0;
+}
+
+int ila_xlat_nl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct ila_dump_iter *iter = (struct ila_dump_iter *)cb->args[0];
+	struct rhashtable_iter *rhiter = &iter->rhiter;
+	int skip = iter->skip;
+	struct ila_map *ila;
+	int ret;
+
+	rhashtable_walk_start(rhiter);
+
+	/* Get first entry */
+	ila = rhashtable_walk_peek(rhiter);
+
+	if (ila && !IS_ERR(ila) && skip) {
+		/* Skip over visited entries */
+
+		while (ila && skip) {
+			/* Skip over any ila entries in this list that we
+			 * have already dumped.
+			 */
+			ila = rcu_access_pointer(ila->next);
+			skip--;
+		}
+	}
+
+	skip = 0;
+
+	for (;;) {
+		if (IS_ERR(ila)) {
+			ret = PTR_ERR(ila);
+			if (ret == -EAGAIN) {
+				/* Table has changed and iter has reset. Return
+				 * -EAGAIN to the application even if we have
+				 * written data to the skb. The application
+				 * needs to deal with this.
+				 */
+
+				goto out_ret;
+			} else {
+				break;
+			}
+		} else if (!ila) {
+			ret = 0;
+			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 out;
+
+			skip++;
+			ila = rcu_access_pointer(ila->next);
+		}
+
+		skip = 0;
+		ila = rhashtable_walk_next(rhiter);
+	}
+
+out:
+	iter->skip = skip;
+	ret = (skb->len ? : ret);
+
+out_ret:
+	rhashtable_walk_stop(rhiter);
+	return ret;
+}
+
+int ila_xlat_init_net(struct net *net)
+{
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+	int err;
+
+	err = alloc_ila_locks(ilan);
+	if (err)
+		return err;
+
+	err = rhashtable_init(&ilan->xlat.rhash_table, &rht_params);
+	if (err) {
+		free_bucket_spinlocks(ilan->xlat.locks);
+		return err;
+	}
+
+	return 0;
+}
+
+void ila_xlat_exit_net(struct net *net)
+{
+	struct ila_net *ilan = net_generic(net, ila_net_id);
+
+	rhashtable_free_and_destroy(&ilan->xlat.rhash_table, ila_free_cb, NULL);
+
+	free_bucket_spinlocks(ilan->xlat.locks);
+
+	if (ilan->xlat.hooks_registered)
+		nf_unregister_net_hooks(net, ila_nf_hook_ops,
+					ARRAY_SIZE(ila_nf_hook_ops));
+}
+
+static int ila_xlat_addr(struct sk_buff *skb, bool sir2ila)
+{
+	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);
+	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
+
+	/* Assumes skb contains a valid IPv6 header that is pulled */
+
+	/* No check here that ILA type in the mapping matches what is in the
+	 * address. We assume that whatever sender gaves us can be translated.
+	 * The checksum mode however is relevant.
+	 */
+
+	rcu_read_lock();
+
+	ila = ila_lookup_wildcards(iaddr, skb->dev->ifindex, ilan);
+	if (ila)
+		ila_update_ipv6_locator(skb, &ila->xp.ip, sir2ila);
+
+	rcu_read_unlock();
+
+	return 0;
+}