[mirror_ubuntu-focal-kernel.git] / net / ipv6 / ila / ila_xlat.c

// 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;
};

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) {
		ilan->locks = kvmalloc(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_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->locks[ila_locator_hash(loc) & ilan->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 struct genl_family ila_nl_family;

static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
	[ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
	[ILA_ATTR_LOCATOR_MATCH] = { .type = NLA_U64, },
	[ILA_ATTR_IFINDEX] = { .type = NLA_U32, },
	[ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
};

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]);

	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->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->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_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, bool set_csum_neutral);

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->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_init_saved_csum(&xp->ip);

	ila->xp = *xp;

	order = ila_order(ila);

	spin_lock(lock);

	head = rhashtable_lookup_fast(&ilan->rhash_table,
				      &xp->ip.locator_match,
				      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, 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->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->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->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 xp;
	int err;

	err = parse_nl_config(info, &xp);
	if (err)
		return err;

	ila_del_mapping(net, &xp);

	return 0;
}

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_u32(msg, ILA_ATTR_CSUM_MODE, ila->xp.ip.csum_mode))
		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 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();

	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;
};

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[0];

	if (!iter) {
		iter = kmalloc(sizeof(*iter), GFP_KERNEL);
		if (!iter)
			return -ENOMEM;

		cb->args[0] = (long)iter;
	}

	return rhashtable_walk_init(&ilan->rhash_table, &iter->rhiter,
				    GFP_KERNEL);
}

static int ila_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;
}

static int ila_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;
	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,
	},
};

static struct genl_family ila_nl_family __ro_after_init = {
	.hdrsize	= 0,
	.name		= ILA_GENL_NAME,
	.version	= ILA_GENL_VERSION,
	.maxattr	= ILA_ATTR_MAX,
	.netnsok	= true,
	.parallel_ops	= true,
	.module		= THIS_MODULE,
	.ops		= ila_nl_ops,
	.n_ops		= ARRAY_SIZE(ila_nl_ops),
};

#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, bool set_csum_neutral)
{
	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 */

	if (!ila_addr_is_ila(iaddr)) {
		/* Type indicates this is not an ILA address */
		return 0;
	}

	rcu_read_lock();

	ila = ila_lookup_wildcards(iaddr, skb->dev->ifindex, ilan);
	if (ila)
		ila_update_ipv6_locator(skb, &ila->xp.ip, set_csum_neutral);

	rcu_read_unlock();

	return 0;
}

int __init ila_xlat_init(void)
{
	int ret;

	ret = register_pernet_device(&ila_net_ops);
	if (ret)
		goto exit;

	ret = genl_register_family(&ila_nl_family);
	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);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
7f00feaf TH	2	#include <linux/jhash.h>
	3	#include <linux/netfilter.h>
	4	#include <linux/rcupdate.h>
	5	#include <linux/rhashtable.h>
	6	#include <linux/vmalloc.h>
	7	#include <net/genetlink.h>
	8	#include <net/ila.h>
	9	#include <net/netns/generic.h>
	10	#include <uapi/linux/genetlink.h>
	11	#include "ila.h"
	12
	13	struct ila_xlat_params {
	14	struct ila_params ip;
7f00feaf	15	int ifindex;
7f00feaf TH	16	};
	17
	18	struct ila_map {
351596aa	19	struct ila_xlat_params xp;
7f00feaf TH	20	struct rhash_head node;
	21	struct ila_map __rcu *next;
	22	struct rcu_head rcu;
	23	};
	24
	25	static unsigned int ila_net_id;
	26
	27	struct ila_net {
	28	struct rhashtable rhash_table;
	29	spinlock_t locks; / Bucket locks for entry manipulation */
	30	unsigned int locks_mask;
	31	bool hooks_registered;
	32	};
	33
	34	#define LOCKS_PER_CPU 10
	35
	36	static int alloc_ila_locks(struct ila_net *ilan)
	37	{
	38	unsigned int i, size;
	39	unsigned int nr_pcpus = num_possible_cpus();
	40
	41	nr_pcpus = min_t(unsigned int, nr_pcpus, 32UL);
	42	size = roundup_pow_of_two(nr_pcpus * LOCKS_PER_CPU);
	43
	44	if (sizeof(spinlock_t) != 0) {
847f716f	45	ilan->locks = kvmalloc(size * sizeof(spinlock_t), GFP_KERNEL);
7f00feaf TH	46	if (!ilan->locks)
	47	return -ENOMEM;
	48	for (i = 0; i < size; i++)
	49	spin_lock_init(&ilan->locks[i]);
	50	}
	51	ilan->locks_mask = size - 1;
	52
	53	return 0;
	54	}
	55
	56	static u32 hashrnd __read_mostly;
	57	static __always_inline void __ila_hash_secret_init(void)
	58	{
	59	net_get_random_once(&hashrnd, sizeof(hashrnd));
	60	}
	61
642c2c95	62	static inline u32 ila_locator_hash(struct ila_locator loc)
7f00feaf	63	{
642c2c95	64	u32 v = (u32 )loc.v32;
7f00feaf	65
0db47e3d	66	__ila_hash_secret_init();
7f00feaf TH	67	return jhash_2words(v[0], v[1], hashrnd);
	68	}
	69
351596aa	70	static inline spinlock_t ila_get_lock(struct ila_net ilan,
642c2c95	71	struct ila_locator loc)
7f00feaf	72	{
642c2c95	73	return &ilan->locks[ila_locator_hash(loc) & ilan->locks_mask];
7f00feaf TH	74	}
7f00feaf TH	75
351596aa	76	static inline int ila_cmp_wildcards(struct ila_map *ila,
642c2c95	77	struct ila_addr *iaddr, int ifindex)
7f00feaf	78	{
642c2c95	79	return (ila->xp.ifindex && ila->xp.ifindex != ifindex);
7f00feaf TH	80	}
7f00feaf TH	81
351596aa TH	82	static inline int ila_cmp_params(struct ila_map *ila,
351596aa TH	83	struct ila_xlat_params *xp)
7f00feaf	84	{
642c2c95	85	return (ila->xp.ifindex != xp->ifindex);
7f00feaf TH	86	}
	87
	88	static int ila_cmpfn(struct rhashtable_compare_arg *arg,
	89	const void *obj)
	90	{
	91	const struct ila_map *ila = obj;
	92
642c2c95	93	return (ila->xp.ip.locator_match.v64 != (__be64 )arg->key);
7f00feaf TH	94	}
	95
	96	static inline int ila_order(struct ila_map *ila)
	97	{
	98	int score = 0;
	99
351596aa	100	if (ila->xp.ifindex)
7f00feaf TH	101	score += 1 << 1;
	102
	103	return score;
	104	}
	105
	106	static const struct rhashtable_params rht_params = {
	107	.nelem_hint = 1024,
	108	.head_offset = offsetof(struct ila_map, node),
642c2c95	109	.key_offset = offsetof(struct ila_map, xp.ip.locator_match),
7f00feaf TH	110	.key_len = sizeof(u64), /* identifier */
	111	.max_size = 1048576,
	112	.min_size = 256,
	113	.automatic_shrinking = true,
	114	.obj_cmpfn = ila_cmpfn,
	115	};
	116
489111e5	117	static struct genl_family ila_nl_family;
7f00feaf	118
6501f34f	119	static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
7f00feaf TH	120	[ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
	121	[ILA_ATTR_LOCATOR_MATCH] = { .type = NLA_U64, },
	122	[ILA_ATTR_IFINDEX] = { .type = NLA_U32, },
90bfe662	123	[ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
7f00feaf TH	124	};
	125
	126	static int parse_nl_config(struct genl_info *info,
351596aa	127	struct ila_xlat_params *xp)
7f00feaf	128	{
351596aa	129	memset(xp, 0, sizeof(*xp));
7f00feaf	130
7f00feaf	131	if (info->attrs[ILA_ATTR_LOCATOR])
351596aa	132	xp->ip.locator.v64 = (__force __be64)nla_get_u64(
7f00feaf TH	133	info->attrs[ILA_ATTR_LOCATOR]);
	134
	135	if (info->attrs[ILA_ATTR_LOCATOR_MATCH])
351596aa	136	xp->ip.locator_match.v64 = (__force __be64)nla_get_u64(
7f00feaf TH	137	info->attrs[ILA_ATTR_LOCATOR_MATCH]);
7f00feaf TH	138
90bfe662 TH	139	if (info->attrs[ILA_ATTR_CSUM_MODE])
	140	xp->ip.csum_mode = nla_get_u8(info->attrs[ILA_ATTR_CSUM_MODE]);
	141
7f00feaf	142	if (info->attrs[ILA_ATTR_IFINDEX])
351596aa	143	xp->ifindex = nla_get_s32(info->attrs[ILA_ATTR_IFINDEX]);
7f00feaf	144
7f00feaf TH	145	return 0;
	146	}
	147
	148	/* Must be called with rcu readlock */
351596aa	149	static inline struct ila_map ila_lookup_wildcards(struct ila_addr iaddr,
7f00feaf	150	int ifindex,
7f00feaf TH	151	struct ila_net *ilan)
	152	{
	153	struct ila_map *ila;
	154
642c2c95	155	ila = rhashtable_lookup_fast(&ilan->rhash_table, &iaddr->loc,
351596aa	156	rht_params);
7f00feaf	157	while (ila) {
642c2c95	158	if (!ila_cmp_wildcards(ila, iaddr, ifindex))
7f00feaf TH	159	return ila;
	160	ila = rcu_access_pointer(ila->next);
	161	}
	162
	163	return NULL;
	164	}
	165
	166	/* Must be called with rcu readlock */
351596aa	167	static inline struct ila_map ila_lookup_by_params(struct ila_xlat_params xp,
7f00feaf TH	168	struct ila_net *ilan)
	169	{
	170	struct ila_map *ila;
	171
642c2c95 TH	172	ila = rhashtable_lookup_fast(&ilan->rhash_table,
642c2c95 TH	173	&xp->ip.locator_match,
7f00feaf TH	174	rht_params);
7f00feaf TH	175	while (ila) {
351596aa	176	if (!ila_cmp_params(ila, xp))
7f00feaf TH	177	return ila;
	178	ila = rcu_access_pointer(ila->next);
	179	}
	180
	181	return NULL;
	182	}
	183
	184	static inline void ila_release(struct ila_map *ila)
	185	{
	186	kfree_rcu(ila, rcu);
	187	}
	188
	189	static void ila_free_cb(void ptr, void arg)
	190	{
	191	struct ila_map ila = (struct ila_map )ptr, *next;
	192
	193	/* Assume rcu_readlock held */
	194	while (ila) {
	195	next = rcu_access_pointer(ila->next);
	196	ila_release(ila);
	197	ila = next;
	198	}
	199	}
	200
707a2ca4	201	static int ila_xlat_addr(struct sk_buff *skb, bool set_csum_neutral);
7f00feaf TH	202
	203	static unsigned int
	204	ila_nf_input(void *priv,
	205	struct sk_buff *skb,
	206	const struct nf_hook_state *state)
	207	{
707a2ca4	208	ila_xlat_addr(skb, false);
7f00feaf TH	209	return NF_ACCEPT;
	210	}
	211
591bb278	212	static const struct nf_hook_ops ila_nf_hook_ops[] = {
7f00feaf TH	213	{
	214	.hook = ila_nf_input,
	215	.pf = NFPROTO_IPV6,
	216	.hooknum = NF_INET_PRE_ROUTING,
	217	.priority = -1,
	218	},
	219	};
	220
351596aa	221	static int ila_add_mapping(struct net net, struct ila_xlat_params xp)
7f00feaf TH	222	{
	223	struct ila_net *ilan = net_generic(net, ila_net_id);
	224	struct ila_map ila, head;
642c2c95	225	spinlock_t *lock = ila_get_lock(ilan, xp->ip.locator_match);
7f00feaf TH	226	int err = 0, order;
	227
	228	if (!ilan->hooks_registered) {
	229	/* We defer registering net hooks in the namespace until the
	230	* first mapping is added.
	231	*/
	232	err = nf_register_net_hooks(net, ila_nf_hook_ops,
	233	ARRAY_SIZE(ila_nf_hook_ops));
	234	if (err)
	235	return err;
	236
	237	ilan->hooks_registered = true;
	238	}
	239
	240	ila = kzalloc(sizeof(*ila), GFP_KERNEL);
	241	if (!ila)
	242	return -ENOMEM;
	243
90bfe662	244	ila_init_saved_csum(&xp->ip);
7f00feaf	245
90bfe662	246	ila->xp = *xp;
7f00feaf TH	247
	248	order = ila_order(ila);
	249
	250	spin_lock(lock);
	251
642c2c95 TH	252	head = rhashtable_lookup_fast(&ilan->rhash_table,
642c2c95 TH	253	&xp->ip.locator_match,
7f00feaf TH	254	rht_params);
	255	if (!head) {
	256	/* New entry for the rhash_table */
	257	err = rhashtable_lookup_insert_fast(&ilan->rhash_table,
	258	&ila->node, rht_params);
	259	} else {
	260	struct ila_map tila = head, prev = NULL;
	261
	262	do {
351596aa	263	if (!ila_cmp_params(tila, xp)) {
7f00feaf TH	264	err = -EEXIST;
	265	goto out;
	266	}
	267
	268	if (order > ila_order(tila))
	269	break;
	270
	271	prev = tila;
	272	tila = rcu_dereference_protected(tila->next,
	273	lockdep_is_held(lock));
	274	} while (tila);
	275
	276	if (prev) {
	277	/* Insert in sub list of head */
	278	RCU_INIT_POINTER(ila->next, tila);
	279	rcu_assign_pointer(prev->next, ila);
	280	} else {
	281	/* Make this ila new head */
	282	RCU_INIT_POINTER(ila->next, head);
	283	err = rhashtable_replace_fast(&ilan->rhash_table,
	284	&head->node,
	285	&ila->node, rht_params);
	286	if (err)
	287	goto out;
	288	}
	289	}
	290
	291	out:
	292	spin_unlock(lock);
	293
	294	if (err)
	295	kfree(ila);
	296
	297	return err;
	298	}
	299
351596aa	300	static int ila_del_mapping(struct net net, struct ila_xlat_params xp)
7f00feaf TH	301	{
	302	struct ila_net *ilan = net_generic(net, ila_net_id);
	303	struct ila_map ila, head, *prev;
642c2c95	304	spinlock_t *lock = ila_get_lock(ilan, xp->ip.locator_match);
7f00feaf TH	305	int err = -ENOENT;
	306
	307	spin_lock(lock);
	308
	309	head = rhashtable_lookup_fast(&ilan->rhash_table,
642c2c95	310	&xp->ip.locator_match, rht_params);
7f00feaf TH	311	ila = head;
	312
	313	prev = NULL;
	314
	315	while (ila) {
351596aa	316	if (ila_cmp_params(ila, xp)) {
7f00feaf TH	317	prev = ila;
	318	ila = rcu_dereference_protected(ila->next,
	319	lockdep_is_held(lock));
	320	continue;
	321	}
	322
	323	err = 0;
	324
	325	if (prev) {
	326	/* Not head, just delete from list */
	327	rcu_assign_pointer(prev->next, ila->next);
	328	} else {
	329	/* It is the head. If there is something in the
	330	* sublist we need to make a new head.
	331	*/
	332	head = rcu_dereference_protected(ila->next,
	333	lockdep_is_held(lock));
	334	if (head) {
	335	/* Put first entry in the sublist into the
	336	* table
	337	*/
	338	err = rhashtable_replace_fast(
	339	&ilan->rhash_table, &ila->node,
	340	&head->node, rht_params);
	341	if (err)
	342	goto out;
	343	} else {
	344	/* Entry no longer used */
	345	err = rhashtable_remove_fast(&ilan->rhash_table,
	346	&ila->node,
	347	rht_params);
	348	}
	349	}
	350
	351	ila_release(ila);
	352
	353	break;
	354	}
	355
	356	out:
	357	spin_unlock(lock);
	358
	359	return err;
	360	}
	361
	362	static int ila_nl_cmd_add_mapping(struct sk_buff skb, struct genl_info info)
	363	{
	364	struct net *net = genl_info_net(info);
	365	struct ila_xlat_params p;
	366	int err;
	367
	368	err = parse_nl_config(info, &p);
	369	if (err)
	370	return err;
	371
	372	return ila_add_mapping(net, &p);
	373	}
	374
	375	static int ila_nl_cmd_del_mapping(struct sk_buff skb, struct genl_info info)
	376	{
	377	struct net *net = genl_info_net(info);
351596aa	378	struct ila_xlat_params xp;
7f00feaf TH	379	int err;
7f00feaf TH	380
351596aa	381	err = parse_nl_config(info, &xp);
7f00feaf TH	382	if (err)
	383	return err;
	384
351596aa	385	ila_del_mapping(net, &xp);
7f00feaf TH	386
	387	return 0;
	388	}
	389
	390	static int ila_fill_info(struct ila_map ila, struct sk_buff msg)
	391	{
642c2c95	392	if (nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR,
351596aa	393	(__force u64)ila->xp.ip.locator.v64,
f13a82d8 ND	394	ILA_ATTR_PAD) \|\|
f13a82d8 ND	395	nla_put_u64_64bit(msg, ILA_ATTR_LOCATOR_MATCH,
351596aa	396	(__force u64)ila->xp.ip.locator_match.v64,
f13a82d8	397	ILA_ATTR_PAD) \|\|
90bfe662 TH	398	nla_put_s32(msg, ILA_ATTR_IFINDEX, ila->xp.ifindex) \|\|
90bfe662 TH	399	nla_put_u32(msg, ILA_ATTR_CSUM_MODE, ila->xp.ip.csum_mode))
7f00feaf TH	400	return -1;
	401
	402	return 0;
	403	}
	404
	405	static int ila_dump_info(struct ila_map *ila,
	406	u32 portid, u32 seq, u32 flags,
	407	struct sk_buff *skb, u8 cmd)
	408	{
	409	void *hdr;
	410
	411	hdr = genlmsg_put(skb, portid, seq, &ila_nl_family, flags, cmd);
	412	if (!hdr)
	413	return -ENOMEM;
	414
	415	if (ila_fill_info(ila, skb) < 0)
	416	goto nla_put_failure;
	417
	418	genlmsg_end(skb, hdr);
	419	return 0;
	420
	421	nla_put_failure:
	422	genlmsg_cancel(skb, hdr);
	423	return -EMSGSIZE;
	424	}
	425
	426	static int ila_nl_cmd_get_mapping(struct sk_buff skb, struct genl_info info)
	427	{
	428	struct net *net = genl_info_net(info);
	429	struct ila_net *ilan = net_generic(net, ila_net_id);
	430	struct sk_buff *msg;
351596aa	431	struct ila_xlat_params xp;
7f00feaf TH	432	struct ila_map *ila;
	433	int ret;
	434
351596aa	435	ret = parse_nl_config(info, &xp);
7f00feaf TH	436	if (ret)
	437	return ret;
	438
	439	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	440	if (!msg)
	441	return -ENOMEM;
	442
	443	rcu_read_lock();
	444
351596aa	445	ila = ila_lookup_by_params(&xp, ilan);
7f00feaf TH	446	if (ila) {
	447	ret = ila_dump_info(ila,
	448	info->snd_portid,
	449	info->snd_seq, 0, msg,
	450	info->genlhdr->cmd);
	451	}
	452
	453	rcu_read_unlock();
	454
	455	if (ret < 0)
	456	goto out_free;
	457
	458	return genlmsg_reply(msg, info);
	459
	460	out_free:
	461	nlmsg_free(msg);
	462	return ret;
	463	}
	464
	465	struct ila_dump_iter {
	466	struct rhashtable_iter rhiter;
	467	};
	468
	469	static int ila_nl_dump_start(struct netlink_callback *cb)
	470	{
	471	struct net *net = sock_net(cb->skb->sk);
	472	struct ila_net *ilan = net_generic(net, ila_net_id);
1913540a TH	473	struct ila_dump_iter iter = (struct ila_dump_iter )cb->args[0];
	474
	475	if (!iter) {
	476	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
	477	if (!iter)
	478	return -ENOMEM;
	479
	480	cb->args[0] = (long)iter;
	481	}
7f00feaf	482
8f6fd83c BC	483	return rhashtable_walk_init(&ilan->rhash_table, &iter->rhiter,
8f6fd83c BC	484	GFP_KERNEL);
7f00feaf TH	485	}
	486
	487	static int ila_nl_dump_done(struct netlink_callback *cb)
	488	{
1913540a	489	struct ila_dump_iter iter = (struct ila_dump_iter )cb->args[0];
7f00feaf TH	490
	491	rhashtable_walk_exit(&iter->rhiter);
	492
1913540a TH	493	kfree(iter);
1913540a TH	494
7f00feaf TH	495	return 0;
	496	}
	497
	498	static int ila_nl_dump(struct sk_buff skb, struct netlink_callback cb)
	499	{
1913540a	500	struct ila_dump_iter iter = (struct ila_dump_iter )cb->args[0];
7f00feaf TH	501	struct rhashtable_iter *rhiter = &iter->rhiter;
	502	struct ila_map *ila;
	503	int ret;
	504
	505	ret = rhashtable_walk_start(rhiter);
	506	if (ret && ret != -EAGAIN)
	507	goto done;
	508
	509	for (;;) {
	510	ila = rhashtable_walk_next(rhiter);
	511
	512	if (IS_ERR(ila)) {
	513	if (PTR_ERR(ila) == -EAGAIN)
	514	continue;
	515	ret = PTR_ERR(ila);
	516	goto done;
	517	} else if (!ila) {
	518	break;
	519	}
	520
	521	while (ila) {
	522	ret = ila_dump_info(ila, NETLINK_CB(cb->skb).portid,
	523	cb->nlh->nlmsg_seq, NLM_F_MULTI,
	524	skb, ILA_CMD_GET);
	525	if (ret)
	526	goto done;
	527
	528	ila = rcu_access_pointer(ila->next);
	529	}
	530	}
	531
	532	ret = skb->len;
	533
	534	done:
	535	rhashtable_walk_stop(rhiter);
	536	return ret;
	537	}
	538
	539	static const struct genl_ops ila_nl_ops[] = {
	540	{
	541	.cmd = ILA_CMD_ADD,
	542	.doit = ila_nl_cmd_add_mapping,
	543	.policy = ila_nl_policy,
	544	.flags = GENL_ADMIN_PERM,
	545	},
	546	{
	547	.cmd = ILA_CMD_DEL,
	548	.doit = ila_nl_cmd_del_mapping,
	549	.policy = ila_nl_policy,
	550	.flags = GENL_ADMIN_PERM,
	551	},
	552	{
	553	.cmd = ILA_CMD_GET,
	554	.doit = ila_nl_cmd_get_mapping,
	555	.start = ila_nl_dump_start,
	556	.dumpit = ila_nl_dump,
	557	.done = ila_nl_dump_done,
	558	.policy = ila_nl_policy,
	559	},
	560	};
	561
56989f6d	562	static struct genl_family ila_nl_family __ro_after_init = {
489111e5 JB	563	.hdrsize = 0,
	564	.name = ILA_GENL_NAME,
	565	.version = ILA_GENL_VERSION,
	566	.maxattr = ILA_ATTR_MAX,
	567	.netnsok = true,
	568	.parallel_ops = true,
	569	.module = THIS_MODULE,
	570	.ops = ila_nl_ops,
	571	.n_ops = ARRAY_SIZE(ila_nl_ops),
	572	};
	573
7f00feaf TH	574	#define ILA_HASH_TABLE_SIZE 1024
	575
	576	static __net_init int ila_init_net(struct net *net)
	577	{
	578	int err;
	579	struct ila_net *ilan = net_generic(net, ila_net_id);
	580
	581	err = alloc_ila_locks(ilan);
	582	if (err)
	583	return err;
	584
	585	rhashtable_init(&ilan->rhash_table, &rht_params);
	586
	587	return 0;
	588	}
	589
	590	static __net_exit void ila_exit_net(struct net *net)
	591	{
	592	struct ila_net *ilan = net_generic(net, ila_net_id);
	593
	594	rhashtable_free_and_destroy(&ilan->rhash_table, ila_free_cb, NULL);
	595
	596	kvfree(ilan->locks);
	597
	598	if (ilan->hooks_registered)
	599	nf_unregister_net_hooks(net, ila_nf_hook_ops,
	600	ARRAY_SIZE(ila_nf_hook_ops));
	601	}
	602
	603	static struct pernet_operations ila_net_ops = {
	604	.init = ila_init_net,
	605	.exit = ila_exit_net,
	606	.id = &ila_net_id,
	607	.size = sizeof(struct ila_net),
	608	};
	609
707a2ca4	610	static int ila_xlat_addr(struct sk_buff *skb, bool set_csum_neutral)
7f00feaf TH	611	{
	612	struct ila_map *ila;
	613	struct ipv6hdr *ip6h = ipv6_hdr(skb);
	614	struct net *net = dev_net(skb->dev);
	615	struct ila_net *ilan = net_generic(net, ila_net_id);
351596aa	616	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
7f00feaf TH	617
	618	/* Assumes skb contains a valid IPv6 header that is pulled */
	619
642c2c95 TH	620	if (!ila_addr_is_ila(iaddr)) {
	621	/* Type indicates this is not an ILA address */
	622	return 0;
	623	}
7f00feaf TH	624
	625	rcu_read_lock();
	626
642c2c95	627	ila = ila_lookup_wildcards(iaddr, skb->dev->ifindex, ilan);
7f00feaf	628	if (ila)
707a2ca4	629	ila_update_ipv6_locator(skb, &ila->xp.ip, set_csum_neutral);
7f00feaf TH	630
	631	rcu_read_unlock();
	632
	633	return 0;
	634	}
	635
56989f6d	636	int __init ila_xlat_init(void)
7f00feaf TH	637	{
	638	int ret;
	639
	640	ret = register_pernet_device(&ila_net_ops);
	641	if (ret)
	642	goto exit;
	643
489111e5	644	ret = genl_register_family(&ila_nl_family);
7f00feaf TH	645	if (ret < 0)
	646	goto unregister;
	647
	648	return 0;
	649
	650	unregister:
	651	unregister_pernet_device(&ila_net_ops);
	652	exit:
	653	return ret;
	654	}
	655
	656	void ila_xlat_fini(void)
	657	{
	658	genl_unregister_family(&ila_nl_family);
	659	unregister_pernet_device(&ila_net_ops);
	660	}