[mirror_ubuntu-jammy-kernel.git] / net / netfilter / nf_flow_table_core.c

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/rhashtable.h>
#include <linux/netdevice.h>
#include <net/ip.h>
#include <net/ip6_route.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_flow_table.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_tuple.h>

struct flow_offload_entry {
	struct flow_offload	flow;
	struct nf_conn		*ct;
	struct rcu_head		rcu_head;
};

static DEFINE_MUTEX(flowtable_lock);
static LIST_HEAD(flowtables);

static void
flow_offload_fill_dir(struct flow_offload *flow, struct nf_conn *ct,
		      struct nf_flow_route *route,
		      enum flow_offload_tuple_dir dir)
{
	struct flow_offload_tuple *ft = &flow->tuplehash[dir].tuple;
	struct nf_conntrack_tuple *ctt = &ct->tuplehash[dir].tuple;
	struct dst_entry *other_dst = route->tuple[!dir].dst;
	struct dst_entry *dst = route->tuple[dir].dst;

	ft->dir = dir;

	switch (ctt->src.l3num) {
	case NFPROTO_IPV4:
		ft->src_v4 = ctt->src.u3.in;
		ft->dst_v4 = ctt->dst.u3.in;
		ft->mtu = ip_dst_mtu_maybe_forward(dst, true);
		break;
	case NFPROTO_IPV6:
		ft->src_v6 = ctt->src.u3.in6;
		ft->dst_v6 = ctt->dst.u3.in6;
		ft->mtu = ip6_dst_mtu_forward(dst);
		break;
	}

	ft->l3proto = ctt->src.l3num;
	ft->l4proto = ctt->dst.protonum;
	ft->src_port = ctt->src.u.tcp.port;
	ft->dst_port = ctt->dst.u.tcp.port;

	ft->iifidx = other_dst->dev->ifindex;
	ft->oifidx = dst->dev->ifindex;
	ft->dst_cache = dst;
}

struct flow_offload *
flow_offload_alloc(struct nf_conn *ct, struct nf_flow_route *route)
{
	struct flow_offload_entry *entry;
	struct flow_offload *flow;

	if (unlikely(nf_ct_is_dying(ct) ||
	    !atomic_inc_not_zero(&ct->ct_general.use)))
		return NULL;

	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
	if (!entry)
		goto err_ct_refcnt;

	flow = &entry->flow;

	if (!dst_hold_safe(route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst))
		goto err_dst_cache_original;

	if (!dst_hold_safe(route->tuple[FLOW_OFFLOAD_DIR_REPLY].dst))
		goto err_dst_cache_reply;

	entry->ct = ct;

	flow_offload_fill_dir(flow, ct, route, FLOW_OFFLOAD_DIR_ORIGINAL);
	flow_offload_fill_dir(flow, ct, route, FLOW_OFFLOAD_DIR_REPLY);

	if (ct->status & IPS_SRC_NAT)
		flow->flags |= FLOW_OFFLOAD_SNAT;
	if (ct->status & IPS_DST_NAT)
		flow->flags |= FLOW_OFFLOAD_DNAT;

	return flow;

err_dst_cache_reply:
	dst_release(route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst);
err_dst_cache_original:
	kfree(entry);
err_ct_refcnt:
	nf_ct_put(ct);

	return NULL;
}
EXPORT_SYMBOL_GPL(flow_offload_alloc);

static void flow_offload_fixup_tcp(struct ip_ct_tcp *tcp)
{
	tcp->state = TCP_CONNTRACK_ESTABLISHED;
	tcp->seen[0].td_maxwin = 0;
	tcp->seen[1].td_maxwin = 0;
}

#define NF_FLOWTABLE_TCP_PICKUP_TIMEOUT	(120 * HZ)
#define NF_FLOWTABLE_UDP_PICKUP_TIMEOUT	(30 * HZ)

static void flow_offload_fixup_ct_state(struct nf_conn *ct)
{
	const struct nf_conntrack_l4proto *l4proto;
	unsigned int timeout;
	int l4num;

	l4num = nf_ct_protonum(ct);
	if (l4num == IPPROTO_TCP)
		flow_offload_fixup_tcp(&ct->proto.tcp);

	l4proto = nf_ct_l4proto_find(l4num);
	if (!l4proto)
		return;

	if (l4num == IPPROTO_TCP)
		timeout = NF_FLOWTABLE_TCP_PICKUP_TIMEOUT;
	else if (l4num == IPPROTO_UDP)
		timeout = NF_FLOWTABLE_UDP_PICKUP_TIMEOUT;
	else
		return;

	ct->timeout = nfct_time_stamp + timeout;
}

void flow_offload_free(struct flow_offload *flow)
{
	struct flow_offload_entry *e;

	dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_cache);
	dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_cache);
	e = container_of(flow, struct flow_offload_entry, flow);
	if (flow->flags & FLOW_OFFLOAD_DYING)
		nf_ct_delete(e->ct, 0, 0);
	nf_ct_put(e->ct);
	kfree_rcu(e, rcu_head);
}
EXPORT_SYMBOL_GPL(flow_offload_free);

static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
{
	const struct flow_offload_tuple *tuple = data;

	return jhash(tuple, offsetof(struct flow_offload_tuple, dir), seed);
}

static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
{
	const struct flow_offload_tuple_rhash *tuplehash = data;

	return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, dir), seed);
}

static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
					const void *ptr)
{
	const struct flow_offload_tuple *tuple = arg->key;
	const struct flow_offload_tuple_rhash *x = ptr;

	if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, dir)))
		return 1;

	return 0;
}

static const struct rhashtable_params nf_flow_offload_rhash_params = {
	.head_offset		= offsetof(struct flow_offload_tuple_rhash, node),
	.hashfn			= flow_offload_hash,
	.obj_hashfn		= flow_offload_hash_obj,
	.obj_cmpfn		= flow_offload_hash_cmp,
	.automatic_shrinking	= true,
};

int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
{
	flow->timeout = (u32)jiffies;

	rhashtable_insert_fast(&flow_table->rhashtable,
			       &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
			       nf_flow_offload_rhash_params);
	rhashtable_insert_fast(&flow_table->rhashtable,
			       &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
			       nf_flow_offload_rhash_params);
	return 0;
}
EXPORT_SYMBOL_GPL(flow_offload_add);

static void flow_offload_del(struct nf_flowtable *flow_table,
			     struct flow_offload *flow)
{
	struct flow_offload_entry *e;

	rhashtable_remove_fast(&flow_table->rhashtable,
			       &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
			       nf_flow_offload_rhash_params);
	rhashtable_remove_fast(&flow_table->rhashtable,
			       &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
			       nf_flow_offload_rhash_params);

	e = container_of(flow, struct flow_offload_entry, flow);
	clear_bit(IPS_OFFLOAD_BIT, &e->ct->status);

	flow_offload_free(flow);
}

void flow_offload_teardown(struct flow_offload *flow)
{
	struct flow_offload_entry *e;

	flow->flags |= FLOW_OFFLOAD_TEARDOWN;

	e = container_of(flow, struct flow_offload_entry, flow);
	flow_offload_fixup_ct_state(e->ct);
}
EXPORT_SYMBOL_GPL(flow_offload_teardown);

struct flow_offload_tuple_rhash *
flow_offload_lookup(struct nf_flowtable *flow_table,
		    struct flow_offload_tuple *tuple)
{
	struct flow_offload_tuple_rhash *tuplehash;
	struct flow_offload *flow;
	int dir;

	tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
				      nf_flow_offload_rhash_params);
	if (!tuplehash)
		return NULL;

	dir = tuplehash->tuple.dir;
	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
	if (flow->flags & (FLOW_OFFLOAD_DYING | FLOW_OFFLOAD_TEARDOWN))
		return NULL;

	return tuplehash;
}
EXPORT_SYMBOL_GPL(flow_offload_lookup);

static int
nf_flow_table_iterate(struct nf_flowtable *flow_table,
		      void (*iter)(struct flow_offload *flow, void *data),
		      void *data)
{
	struct flow_offload_tuple_rhash *tuplehash;
	struct rhashtable_iter hti;
	struct flow_offload *flow;
	int err = 0;

	rhashtable_walk_enter(&flow_table->rhashtable, &hti);
	rhashtable_walk_start(&hti);

	while ((tuplehash = rhashtable_walk_next(&hti))) {
		if (IS_ERR(tuplehash)) {
			if (PTR_ERR(tuplehash) != -EAGAIN) {
				err = PTR_ERR(tuplehash);
				break;
			}
			continue;
		}
		if (tuplehash->tuple.dir)
			continue;

		flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);

		iter(flow, data);
	}
	rhashtable_walk_stop(&hti);
	rhashtable_walk_exit(&hti);

	return err;
}

static inline bool nf_flow_has_expired(const struct flow_offload *flow)
{
	return (__s32)(flow->timeout - (u32)jiffies) <= 0;
}

static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
{
	struct nf_flowtable *flow_table = data;

	if (nf_flow_has_expired(flow) ||
	    (flow->flags & (FLOW_OFFLOAD_DYING | FLOW_OFFLOAD_TEARDOWN)))
		flow_offload_del(flow_table, flow);
}

static void nf_flow_offload_work_gc(struct work_struct *work)
{
	struct nf_flowtable *flow_table;

	flow_table = container_of(work, struct nf_flowtable, gc_work.work);
	nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
	queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
}

static int nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
				__be16 port, __be16 new_port)
{
	struct tcphdr *tcph;

	if (!pskb_may_pull(skb, thoff + sizeof(*tcph)) ||
	    skb_try_make_writable(skb, thoff + sizeof(*tcph)))
		return -1;

	tcph = (void *)(skb_network_header(skb) + thoff);
	inet_proto_csum_replace2(&tcph->check, skb, port, new_port, true);

	return 0;
}

static int nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
				__be16 port, __be16 new_port)
{
	struct udphdr *udph;

	if (!pskb_may_pull(skb, thoff + sizeof(*udph)) ||
	    skb_try_make_writable(skb, thoff + sizeof(*udph)))
		return -1;

	udph = (void *)(skb_network_header(skb) + thoff);
	if (udph->check || skb->ip_summed == CHECKSUM_PARTIAL) {
		inet_proto_csum_replace2(&udph->check, skb, port,
					 new_port, true);
		if (!udph->check)
			udph->check = CSUM_MANGLED_0;
	}

	return 0;
}

static int nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
			    u8 protocol, __be16 port, __be16 new_port)
{
	switch (protocol) {
	case IPPROTO_TCP:
		if (nf_flow_nat_port_tcp(skb, thoff, port, new_port) < 0)
			return NF_DROP;
		break;
	case IPPROTO_UDP:
		if (nf_flow_nat_port_udp(skb, thoff, port, new_port) < 0)
			return NF_DROP;
		break;
	}

	return 0;
}

int nf_flow_snat_port(const struct flow_offload *flow,
		      struct sk_buff *skb, unsigned int thoff,
		      u8 protocol, enum flow_offload_tuple_dir dir)
{
	struct flow_ports *hdr;
	__be16 port, new_port;

	if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) ||
	    skb_try_make_writable(skb, thoff + sizeof(*hdr)))
		return -1;

	hdr = (void *)(skb_network_header(skb) + thoff);

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		port = hdr->source;
		new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
		hdr->source = new_port;
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		port = hdr->dest;
		new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
		hdr->dest = new_port;
		break;
	default:
		return -1;
	}

	return nf_flow_nat_port(skb, thoff, protocol, port, new_port);
}
EXPORT_SYMBOL_GPL(nf_flow_snat_port);

int nf_flow_dnat_port(const struct flow_offload *flow,
		      struct sk_buff *skb, unsigned int thoff,
		      u8 protocol, enum flow_offload_tuple_dir dir)
{
	struct flow_ports *hdr;
	__be16 port, new_port;

	if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) ||
	    skb_try_make_writable(skb, thoff + sizeof(*hdr)))
		return -1;

	hdr = (void *)(skb_network_header(skb) + thoff);

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		port = hdr->dest;
		new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
		hdr->dest = new_port;
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		port = hdr->source;
		new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
		hdr->source = new_port;
		break;
	default:
		return -1;
	}

	return nf_flow_nat_port(skb, thoff, protocol, port, new_port);
}
EXPORT_SYMBOL_GPL(nf_flow_dnat_port);

int nf_flow_table_init(struct nf_flowtable *flowtable)
{
	int err;

	INIT_DEFERRABLE_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);

	err = rhashtable_init(&flowtable->rhashtable,
			      &nf_flow_offload_rhash_params);
	if (err < 0)
		return err;

	queue_delayed_work(system_power_efficient_wq,
			   &flowtable->gc_work, HZ);

	mutex_lock(&flowtable_lock);
	list_add(&flowtable->list, &flowtables);
	mutex_unlock(&flowtable_lock);

	return 0;
}
EXPORT_SYMBOL_GPL(nf_flow_table_init);

static void nf_flow_table_do_cleanup(struct flow_offload *flow, void *data)
{
	struct net_device *dev = data;
	struct flow_offload_entry *e;

	e = container_of(flow, struct flow_offload_entry, flow);

	if (!dev) {
		flow_offload_teardown(flow);
		return;
	}
	if (net_eq(nf_ct_net(e->ct), dev_net(dev)) &&
	    (flow->tuplehash[0].tuple.iifidx == dev->ifindex ||
	     flow->tuplehash[1].tuple.iifidx == dev->ifindex))
		flow_offload_dead(flow);
}

static void nf_flow_table_iterate_cleanup(struct nf_flowtable *flowtable,
					  struct net_device *dev)
{
	nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
	flush_delayed_work(&flowtable->gc_work);
}

void nf_flow_table_cleanup(struct net_device *dev)
{
	struct nf_flowtable *flowtable;

	mutex_lock(&flowtable_lock);
	list_for_each_entry(flowtable, &flowtables, list)
		nf_flow_table_iterate_cleanup(flowtable, dev);
	mutex_unlock(&flowtable_lock);
}
EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);

void nf_flow_table_free(struct nf_flowtable *flow_table)
{
	mutex_lock(&flowtable_lock);
	list_del(&flow_table->list);
	mutex_unlock(&flowtable_lock);
	cancel_delayed_work_sync(&flow_table->gc_work);
	nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
	nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
	rhashtable_destroy(&flow_table->rhashtable);
}
EXPORT_SYMBOL_GPL(nf_flow_table_free);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
Commit	Line	Data
ac2a6666 PNA	1	#include <linux/kernel.h>
	2	#include <linux/init.h>
	3	#include <linux/module.h>
	4	#include <linux/netfilter.h>
	5	#include <linux/rhashtable.h>
	6	#include <linux/netdevice.h>
4f3780c0 FF	7	#include <net/ip.h>
4f3780c0 FF	8	#include <net/ip6_route.h>
c0ea1bcb	9	#include <net/netfilter/nf_tables.h>
ac2a6666 PNA	10	#include <net/netfilter/nf_flow_table.h>
	11	#include <net/netfilter/nf_conntrack.h>
	12	#include <net/netfilter/nf_conntrack_core.h>
	13	#include <net/netfilter/nf_conntrack_tuple.h>
	14
	15	struct flow_offload_entry {
	16	struct flow_offload flow;
	17	struct nf_conn *ct;
	18	struct rcu_head rcu_head;
	19	};
	20
84453a90 FF	21	static DEFINE_MUTEX(flowtable_lock);
	22	static LIST_HEAD(flowtables);
	23
047b300e FF	24	static void
	25	flow_offload_fill_dir(struct flow_offload flow, struct nf_conn ct,
	26	struct nf_flow_route *route,
	27	enum flow_offload_tuple_dir dir)
	28	{
	29	struct flow_offload_tuple *ft = &flow->tuplehash[dir].tuple;
	30	struct nf_conntrack_tuple *ctt = &ct->tuplehash[dir].tuple;
10f4e765	31	struct dst_entry *other_dst = route->tuple[!dir].dst;
4f3780c0	32	struct dst_entry *dst = route->tuple[dir].dst;
047b300e FF	33
	34	ft->dir = dir;
	35
	36	switch (ctt->src.l3num) {
	37	case NFPROTO_IPV4:
	38	ft->src_v4 = ctt->src.u3.in;
	39	ft->dst_v4 = ctt->dst.u3.in;
4f3780c0	40	ft->mtu = ip_dst_mtu_maybe_forward(dst, true);
047b300e FF	41	break;
	42	case NFPROTO_IPV6:
	43	ft->src_v6 = ctt->src.u3.in6;
	44	ft->dst_v6 = ctt->dst.u3.in6;
4f3780c0	45	ft->mtu = ip6_dst_mtu_forward(dst);
047b300e FF	46	break;
	47	}
	48
	49	ft->l3proto = ctt->src.l3num;
	50	ft->l4proto = ctt->dst.protonum;
	51	ft->src_port = ctt->src.u.tcp.port;
	52	ft->dst_port = ctt->dst.u.tcp.port;
	53
10f4e765	54	ft->iifidx = other_dst->dev->ifindex;
10f4e765	55	ft->oifidx = dst->dev->ifindex;
4f3780c0	56	ft->dst_cache = dst;
047b300e FF	57	}
047b300e FF	58
ac2a6666 PNA	59	struct flow_offload *
	60	flow_offload_alloc(struct nf_conn ct, struct nf_flow_route route)
	61	{
	62	struct flow_offload_entry *entry;
	63	struct flow_offload *flow;
	64
	65	if (unlikely(nf_ct_is_dying(ct) \|\|
	66	!atomic_inc_not_zero(&ct->ct_general.use)))
	67	return NULL;
	68
	69	entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
	70	if (!entry)
	71	goto err_ct_refcnt;
	72
	73	flow = &entry->flow;
	74
	75	if (!dst_hold_safe(route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst))
	76	goto err_dst_cache_original;
	77
	78	if (!dst_hold_safe(route->tuple[FLOW_OFFLOAD_DIR_REPLY].dst))
	79	goto err_dst_cache_reply;
	80
	81	entry->ct = ct;
	82
047b300e FF	83	flow_offload_fill_dir(flow, ct, route, FLOW_OFFLOAD_DIR_ORIGINAL);
047b300e FF	84	flow_offload_fill_dir(flow, ct, route, FLOW_OFFLOAD_DIR_REPLY);
ac2a6666 PNA	85
	86	if (ct->status & IPS_SRC_NAT)
	87	flow->flags \|= FLOW_OFFLOAD_SNAT;
df1e2025	88	if (ct->status & IPS_DST_NAT)
ac2a6666 PNA	89	flow->flags \|= FLOW_OFFLOAD_DNAT;
	90
	91	return flow;
	92
	93	err_dst_cache_reply:
	94	dst_release(route->tuple[FLOW_OFFLOAD_DIR_ORIGINAL].dst);
	95	err_dst_cache_original:
	96	kfree(entry);
	97	err_ct_refcnt:
	98	nf_ct_put(ct);
	99
	100	return NULL;
	101	}
	102	EXPORT_SYMBOL_GPL(flow_offload_alloc);
	103
da5984e5 FF	104	static void flow_offload_fixup_tcp(struct ip_ct_tcp *tcp)
	105	{
	106	tcp->state = TCP_CONNTRACK_ESTABLISHED;
	107	tcp->seen[0].td_maxwin = 0;
	108	tcp->seen[1].td_maxwin = 0;
	109	}
	110
e97d9404 FW	111	#define NF_FLOWTABLE_TCP_PICKUP_TIMEOUT (120 * HZ)
	112	#define NF_FLOWTABLE_UDP_PICKUP_TIMEOUT (30 * HZ)
	113
da5984e5 FF	114	static void flow_offload_fixup_ct_state(struct nf_conn *ct)
	115	{
	116	const struct nf_conntrack_l4proto *l4proto;
da5984e5 FF	117	unsigned int timeout;
	118	int l4num;
	119
	120	l4num = nf_ct_protonum(ct);
	121	if (l4num == IPPROTO_TCP)
	122	flow_offload_fixup_tcp(&ct->proto.tcp);
	123
4a60dc74	124	l4proto = nf_ct_l4proto_find(l4num);
da5984e5 FF	125	if (!l4proto)
	126	return;
	127
da5984e5	128	if (l4num == IPPROTO_TCP)
e97d9404	129	timeout = NF_FLOWTABLE_TCP_PICKUP_TIMEOUT;
da5984e5	130	else if (l4num == IPPROTO_UDP)
e97d9404	131	timeout = NF_FLOWTABLE_UDP_PICKUP_TIMEOUT;
da5984e5 FF	132	else
	133	return;
	134
	135	ct->timeout = nfct_time_stamp + timeout;
	136	}
	137
ac2a6666 PNA	138	void flow_offload_free(struct flow_offload *flow)
	139	{
	140	struct flow_offload_entry *e;
	141
	142	dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_cache);
	143	dst_release(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_cache);
	144	e = container_of(flow, struct flow_offload_entry, flow);
da5984e5 FF	145	if (flow->flags & FLOW_OFFLOAD_DYING)
da5984e5 FF	146	nf_ct_delete(e->ct, 0, 0);
0ff90b6c FF	147	nf_ct_put(e->ct);
0ff90b6c FF	148	kfree_rcu(e, rcu_head);
ac2a6666 PNA	149	}
	150	EXPORT_SYMBOL_GPL(flow_offload_free);
	151
a268de77 FF	152	static u32 flow_offload_hash(const void *data, u32 len, u32 seed)
	153	{
	154	const struct flow_offload_tuple *tuple = data;
	155
	156	return jhash(tuple, offsetof(struct flow_offload_tuple, dir), seed);
	157	}
	158
	159	static u32 flow_offload_hash_obj(const void *data, u32 len, u32 seed)
	160	{
	161	const struct flow_offload_tuple_rhash *tuplehash = data;
	162
	163	return jhash(&tuplehash->tuple, offsetof(struct flow_offload_tuple, dir), seed);
	164	}
	165
	166	static int flow_offload_hash_cmp(struct rhashtable_compare_arg *arg,
	167	const void *ptr)
	168	{
	169	const struct flow_offload_tuple *tuple = arg->key;
	170	const struct flow_offload_tuple_rhash *x = ptr;
	171
	172	if (memcmp(&x->tuple, tuple, offsetof(struct flow_offload_tuple, dir)))
	173	return 1;
	174
	175	return 0;
	176	}
	177
	178	static const struct rhashtable_params nf_flow_offload_rhash_params = {
	179	.head_offset = offsetof(struct flow_offload_tuple_rhash, node),
	180	.hashfn = flow_offload_hash,
	181	.obj_hashfn = flow_offload_hash_obj,
	182	.obj_cmpfn = flow_offload_hash_cmp,
	183	.automatic_shrinking = true,
	184	};
	185
ac2a6666 PNA	186	int flow_offload_add(struct nf_flowtable flow_table, struct flow_offload flow)
	187	{
	188	flow->timeout = (u32)jiffies;
	189
	190	rhashtable_insert_fast(&flow_table->rhashtable,
	191	&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
a268de77	192	nf_flow_offload_rhash_params);
ac2a6666 PNA	193	rhashtable_insert_fast(&flow_table->rhashtable,
ac2a6666 PNA	194	&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
a268de77	195	nf_flow_offload_rhash_params);
ac2a6666 PNA	196	return 0;
	197	}
	198	EXPORT_SYMBOL_GPL(flow_offload_add);
	199
0ff90b6c FF	200	static void flow_offload_del(struct nf_flowtable *flow_table,
0ff90b6c FF	201	struct flow_offload *flow)
ac2a6666	202	{
da5984e5 FF	203	struct flow_offload_entry *e;
da5984e5 FF	204
ac2a6666 PNA	205	rhashtable_remove_fast(&flow_table->rhashtable,
ac2a6666 PNA	206	&flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
a268de77	207	nf_flow_offload_rhash_params);
ac2a6666 PNA	208	rhashtable_remove_fast(&flow_table->rhashtable,
ac2a6666 PNA	209	&flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
a268de77	210	nf_flow_offload_rhash_params);
ac2a6666	211
da5984e5 FF	212	e = container_of(flow, struct flow_offload_entry, flow);
	213	clear_bit(IPS_OFFLOAD_BIT, &e->ct->status);
	214
0ff90b6c	215	flow_offload_free(flow);
ac2a6666	216	}
ac2a6666	217
59c466dd FF	218	void flow_offload_teardown(struct flow_offload *flow)
59c466dd FF	219	{
da5984e5 FF	220	struct flow_offload_entry *e;
da5984e5 FF	221
59c466dd	222	flow->flags \|= FLOW_OFFLOAD_TEARDOWN;
da5984e5 FF	223
	224	e = container_of(flow, struct flow_offload_entry, flow);
	225	flow_offload_fixup_ct_state(e->ct);
59c466dd FF	226	}
	227	EXPORT_SYMBOL_GPL(flow_offload_teardown);
	228
ac2a6666 PNA	229	struct flow_offload_tuple_rhash *
	230	flow_offload_lookup(struct nf_flowtable *flow_table,
	231	struct flow_offload_tuple *tuple)
	232	{
ba03137f FF	233	struct flow_offload_tuple_rhash *tuplehash;
	234	struct flow_offload *flow;
	235	int dir;
	236
a2d88182 TY	237	tuplehash = rhashtable_lookup(&flow_table->rhashtable, tuple,
a2d88182 TY	238	nf_flow_offload_rhash_params);
ba03137f FF	239	if (!tuplehash)
	240	return NULL;
	241
	242	dir = tuplehash->tuple.dir;
	243	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
	244	if (flow->flags & (FLOW_OFFLOAD_DYING \| FLOW_OFFLOAD_TEARDOWN))
	245	return NULL;
	246
	247	return tuplehash;
ac2a6666 PNA	248	}
	249	EXPORT_SYMBOL_GPL(flow_offload_lookup);
	250
49de9c09 TY	251	static int
	252	nf_flow_table_iterate(struct nf_flowtable *flow_table,
	253	void (iter)(struct flow_offload flow, void *data),
	254	void *data)
ac2a6666 PNA	255	{
	256	struct flow_offload_tuple_rhash *tuplehash;
	257	struct rhashtable_iter hti;
	258	struct flow_offload *flow;
0de22baa	259	int err = 0;
ac2a6666	260
0de22baa	261	rhashtable_walk_enter(&flow_table->rhashtable, &hti);
ac2a6666 PNA	262	rhashtable_walk_start(&hti);
	263
	264	while ((tuplehash = rhashtable_walk_next(&hti))) {
	265	if (IS_ERR(tuplehash)) {
0de22baa TY	266	if (PTR_ERR(tuplehash) != -EAGAIN) {
	267	err = PTR_ERR(tuplehash);
	268	break;
	269	}
ac2a6666 PNA	270	continue;
	271	}
	272	if (tuplehash->tuple.dir)
	273	continue;
	274
	275	flow = container_of(tuplehash, struct flow_offload, tuplehash[0]);
	276
	277	iter(flow, data);
	278	}
ac2a6666 PNA	279	rhashtable_walk_stop(&hti);
	280	rhashtable_walk_exit(&hti);
	281
	282	return err;
	283	}
ac2a6666 PNA	284
	285	static inline bool nf_flow_has_expired(const struct flow_offload *flow)
	286	{
	287	return (__s32)(flow->timeout - (u32)jiffies) <= 0;
	288	}
	289
b9660987	290	static void nf_flow_offload_gc_step(struct flow_offload flow, void data)
ac2a6666	291	{
b9660987	292	struct nf_flowtable *flow_table = data;
ac2a6666	293
b9660987 TY	294	if (nf_flow_has_expired(flow) \|\|
	295	(flow->flags & (FLOW_OFFLOAD_DYING \| FLOW_OFFLOAD_TEARDOWN)))
	296	flow_offload_del(flow_table, flow);
b408c5b0 PNA	297	}
b408c5b0 PNA	298
a268de77	299	static void nf_flow_offload_work_gc(struct work_struct *work)
b408c5b0 PNA	300	{
	301	struct nf_flowtable *flow_table;
	302
	303	flow_table = container_of(work, struct nf_flowtable, gc_work.work);
b9660987	304	nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
ac2a6666 PNA	305	queue_delayed_work(system_power_efficient_wq, &flow_table->gc_work, HZ);
ac2a6666 PNA	306	}
ac2a6666 PNA	307
	308	static int nf_flow_nat_port_tcp(struct sk_buff *skb, unsigned int thoff,
	309	__be16 port, __be16 new_port)
	310	{
	311	struct tcphdr *tcph;
	312
	313	if (!pskb_may_pull(skb, thoff + sizeof(*tcph)) \|\|
	314	skb_try_make_writable(skb, thoff + sizeof(*tcph)))
	315	return -1;
	316
	317	tcph = (void *)(skb_network_header(skb) + thoff);
	318	inet_proto_csum_replace2(&tcph->check, skb, port, new_port, true);
	319
	320	return 0;
	321	}
	322
	323	static int nf_flow_nat_port_udp(struct sk_buff *skb, unsigned int thoff,
	324	__be16 port, __be16 new_port)
	325	{
	326	struct udphdr *udph;
	327
	328	if (!pskb_may_pull(skb, thoff + sizeof(*udph)) \|\|
	329	skb_try_make_writable(skb, thoff + sizeof(*udph)))
	330	return -1;
	331
	332	udph = (void *)(skb_network_header(skb) + thoff);
	333	if (udph->check \|\| skb->ip_summed == CHECKSUM_PARTIAL) {
	334	inet_proto_csum_replace2(&udph->check, skb, port,
	335	new_port, true);
	336	if (!udph->check)
	337	udph->check = CSUM_MANGLED_0;
	338	}
	339
	340	return 0;
	341	}
	342
	343	static int nf_flow_nat_port(struct sk_buff *skb, unsigned int thoff,
	344	u8 protocol, __be16 port, __be16 new_port)
	345	{
	346	switch (protocol) {
	347	case IPPROTO_TCP:
	348	if (nf_flow_nat_port_tcp(skb, thoff, port, new_port) < 0)
	349	return NF_DROP;
	350	break;
	351	case IPPROTO_UDP:
	352	if (nf_flow_nat_port_udp(skb, thoff, port, new_port) < 0)
	353	return NF_DROP;
	354	break;
	355	}
	356
	357	return 0;
	358	}
	359
	360	int nf_flow_snat_port(const struct flow_offload *flow,
	361	struct sk_buff *skb, unsigned int thoff,
	362	u8 protocol, enum flow_offload_tuple_dir dir)
	363	{
	364	struct flow_ports *hdr;
	365	__be16 port, new_port;
	366
	367	if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) \|\|
	368	skb_try_make_writable(skb, thoff + sizeof(*hdr)))
	369	return -1;
	370
371	hdr = (void *)(skb_network_header(skb) + thoff);
372
373	switch (dir) {
374	case FLOW_OFFLOAD_DIR_ORIGINAL:
375	port = hdr->source;
376	new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port;
377	hdr->source = new_port;
378	break;
379	case FLOW_OFFLOAD_DIR_REPLY:
380	port = hdr->dest;
381	new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port;
382	hdr->dest = new_port;
383	break;
384	default:
385	return -1;
386	}
387
388	return nf_flow_nat_port(skb, thoff, protocol, port, new_port);
389	}
390	EXPORT_SYMBOL_GPL(nf_flow_snat_port);
391
392	int nf_flow_dnat_port(const struct flow_offload *flow,
393	struct sk_buff *skb, unsigned int thoff,
394	u8 protocol, enum flow_offload_tuple_dir dir)
395	{
396	struct flow_ports *hdr;
397	__be16 port, new_port;
398
399	if (!pskb_may_pull(skb, thoff + sizeof(*hdr)) \|\|
400	skb_try_make_writable(skb, thoff + sizeof(*hdr)))
401	return -1;
402
403	hdr = (void *)(skb_network_header(skb) + thoff);
404
405	switch (dir) {
406	case FLOW_OFFLOAD_DIR_ORIGINAL:
407	port = hdr->dest;
408	new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port;
409	hdr->dest = new_port;
410	break;
411	case FLOW_OFFLOAD_DIR_REPLY:
412	port = hdr->source;
413	new_port = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port;
414	hdr->source = new_port;
415	break;
416	default:
417	return -1;
418	}
419
420	return nf_flow_nat_port(skb, thoff, protocol, port, new_port);
421	}
422	EXPORT_SYMBOL_GPL(nf_flow_dnat_port);
423
a268de77 FF	424	int nf_flow_table_init(struct nf_flowtable *flowtable)
	425	{
	426	int err;
	427
	428	INIT_DEFERRABLE_WORK(&flowtable->gc_work, nf_flow_offload_work_gc);
	429
	430	err = rhashtable_init(&flowtable->rhashtable,
	431	&nf_flow_offload_rhash_params);
	432	if (err < 0)
	433	return err;
	434
	435	queue_delayed_work(system_power_efficient_wq,
	436	&flowtable->gc_work, HZ);
	437
84453a90 FF	438	mutex_lock(&flowtable_lock);
	439	list_add(&flowtable->list, &flowtables);
	440	mutex_unlock(&flowtable_lock);
	441
a268de77 FF	442	return 0;
	443	}
	444	EXPORT_SYMBOL_GPL(nf_flow_table_init);
	445
c0ea1bcb PNA	446	static void nf_flow_table_do_cleanup(struct flow_offload flow, void data)
	447	{
	448	struct net_device *dev = data;
a3fb3698 TY	449	struct flow_offload_entry *e;
	450
	451	e = container_of(flow, struct flow_offload_entry, flow);
c0ea1bcb	452
59c466dd FF	453	if (!dev) {
59c466dd FF	454	flow_offload_teardown(flow);
c0ea1bcb	455	return;
59c466dd	456	}
a3fb3698 TY	457	if (net_eq(nf_ct_net(e->ct), dev_net(dev)) &&
	458	(flow->tuplehash[0].tuple.iifidx == dev->ifindex \|\|
	459	flow->tuplehash[1].tuple.iifidx == dev->ifindex))
59c466dd	460	flow_offload_dead(flow);
c0ea1bcb PNA	461	}
	462
	463	static void nf_flow_table_iterate_cleanup(struct nf_flowtable *flowtable,
84453a90	464	struct net_device *dev)
c0ea1bcb	465	{
84453a90	466	nf_flow_table_iterate(flowtable, nf_flow_table_do_cleanup, dev);
c0ea1bcb PNA	467	flush_delayed_work(&flowtable->gc_work);
	468	}
	469
5f1be84a	470	void nf_flow_table_cleanup(struct net_device *dev)
c0ea1bcb	471	{
84453a90 FF	472	struct nf_flowtable *flowtable;
	473
	474	mutex_lock(&flowtable_lock);
	475	list_for_each_entry(flowtable, &flowtables, list)
	476	nf_flow_table_iterate_cleanup(flowtable, dev);
	477	mutex_unlock(&flowtable_lock);
c0ea1bcb PNA	478	}
	479	EXPORT_SYMBOL_GPL(nf_flow_table_cleanup);
	480
b408c5b0 PNA	481	void nf_flow_table_free(struct nf_flowtable *flow_table)
b408c5b0 PNA	482	{
84453a90 FF	483	mutex_lock(&flowtable_lock);
	484	list_del(&flow_table->list);
	485	mutex_unlock(&flowtable_lock);
a268de77	486	cancel_delayed_work_sync(&flow_table->gc_work);
b408c5b0	487	nf_flow_table_iterate(flow_table, nf_flow_table_do_cleanup, NULL);
b9660987	488	nf_flow_table_iterate(flow_table, nf_flow_offload_gc_step, flow_table);
a268de77	489	rhashtable_destroy(&flow_table->rhashtable);
b408c5b0 PNA	490	}
	491	EXPORT_SYMBOL_GPL(nf_flow_table_free);
	492
ac2a6666 PNA	493	MODULE_LICENSE("GPL");
ac2a6666 PNA	494	MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");