[mirror_ubuntu-zesty-kernel.git] / net / sched / cls_flow.c

/*
 * net/sched/cls_flow.c		Generic flow classifier
 *
 * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <linux/pkt_cls.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/if_vlan.h>
#include <linux/slab.h>
#include <linux/module.h>

#include <net/pkt_cls.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/flow_keys.h>

#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
#include <net/netfilter/nf_conntrack.h>
#endif

struct flow_head {
	struct list_head	filters;
};

struct flow_filter {
	struct list_head	list;
	struct tcf_exts		exts;
	struct tcf_ematch_tree	ematches;
	struct timer_list	perturb_timer;
	u32			perturb_period;
	u32			handle;

	u32			nkeys;
	u32			keymask;
	u32			mode;
	u32			mask;
	u32			xor;
	u32			rshift;
	u32			addend;
	u32			divisor;
	u32			baseclass;
	u32			hashrnd;
};

static const struct tcf_ext_map flow_ext_map = {
	.action	= TCA_FLOW_ACT,
	.police	= TCA_FLOW_POLICE,
};

static inline u32 addr_fold(void *addr)
{
	unsigned long a = (unsigned long)addr;

	return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
}

static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
{
	if (flow->src)
		return ntohl(flow->src);
	return addr_fold(skb->sk);
}

static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
{
	if (flow->dst)
		return ntohl(flow->dst);
	return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
}

static u32 flow_get_proto(const struct sk_buff *skb, const struct flow_keys *flow)
{
	return flow->ip_proto;
}

static u32 flow_get_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
{
	if (flow->ports)
		return ntohs(flow->port16[0]);

	return addr_fold(skb->sk);
}

static u32 flow_get_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
{
	if (flow->ports)
		return ntohs(flow->port16[1]);

	return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
}

static u32 flow_get_iif(const struct sk_buff *skb)
{
	return skb->skb_iif;
}

static u32 flow_get_priority(const struct sk_buff *skb)
{
	return skb->priority;
}

static u32 flow_get_mark(const struct sk_buff *skb)
{
	return skb->mark;
}

static u32 flow_get_nfct(const struct sk_buff *skb)
{
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
	return addr_fold(skb->nfct);
#else
	return 0;
#endif
}

#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
#define CTTUPLE(skb, member)						\
({									\
	enum ip_conntrack_info ctinfo;					\
	const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);		\
	if (ct == NULL)							\
		goto fallback;						\
	ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;			\
})
#else
#define CTTUPLE(skb, member)						\
({									\
	goto fallback;							\
	0;								\
})
#endif

static u32 flow_get_nfct_src(const struct sk_buff *skb, const struct flow_keys *flow)
{
	switch (skb->protocol) {
	case htons(ETH_P_IP):
		return ntohl(CTTUPLE(skb, src.u3.ip));
	case htons(ETH_P_IPV6):
		return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
	}
fallback:
	return flow_get_src(skb, flow);
}

static u32 flow_get_nfct_dst(const struct sk_buff *skb, const struct flow_keys *flow)
{
	switch (skb->protocol) {
	case htons(ETH_P_IP):
		return ntohl(CTTUPLE(skb, dst.u3.ip));
	case htons(ETH_P_IPV6):
		return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
	}
fallback:
	return flow_get_dst(skb, flow);
}

static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
{
	return ntohs(CTTUPLE(skb, src.u.all));
fallback:
	return flow_get_proto_src(skb, flow);
}

static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
{
	return ntohs(CTTUPLE(skb, dst.u.all));
fallback:
	return flow_get_proto_dst(skb, flow);
}

static u32 flow_get_rtclassid(const struct sk_buff *skb)
{
#ifdef CONFIG_IP_ROUTE_CLASSID
	if (skb_dst(skb))
		return skb_dst(skb)->tclassid;
#endif
	return 0;
}

static u32 flow_get_skuid(const struct sk_buff *skb)
{
	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
		kuid_t skuid = skb->sk->sk_socket->file->f_cred->fsuid;
		return from_kuid(&init_user_ns, skuid);
	}
	return 0;
}

static u32 flow_get_skgid(const struct sk_buff *skb)
{
	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
		kgid_t skgid = skb->sk->sk_socket->file->f_cred->fsgid;
		return from_kgid(&init_user_ns, skgid);
	}
	return 0;
}

static u32 flow_get_vlan_tag(const struct sk_buff *skb)
{
	u16 uninitialized_var(tag);

	if (vlan_get_tag(skb, &tag) < 0)
		return 0;
	return tag & VLAN_VID_MASK;
}

static u32 flow_get_rxhash(struct sk_buff *skb)
{
	return skb_get_hash(skb);
}

static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
{
	switch (key) {
	case FLOW_KEY_SRC:
		return flow_get_src(skb, flow);
	case FLOW_KEY_DST:
		return flow_get_dst(skb, flow);
	case FLOW_KEY_PROTO:
		return flow_get_proto(skb, flow);
	case FLOW_KEY_PROTO_SRC:
		return flow_get_proto_src(skb, flow);
	case FLOW_KEY_PROTO_DST:
		return flow_get_proto_dst(skb, flow);
	case FLOW_KEY_IIF:
		return flow_get_iif(skb);
	case FLOW_KEY_PRIORITY:
		return flow_get_priority(skb);
	case FLOW_KEY_MARK:
		return flow_get_mark(skb);
	case FLOW_KEY_NFCT:
		return flow_get_nfct(skb);
	case FLOW_KEY_NFCT_SRC:
		return flow_get_nfct_src(skb, flow);
	case FLOW_KEY_NFCT_DST:
		return flow_get_nfct_dst(skb, flow);
	case FLOW_KEY_NFCT_PROTO_SRC:
		return flow_get_nfct_proto_src(skb, flow);
	case FLOW_KEY_NFCT_PROTO_DST:
		return flow_get_nfct_proto_dst(skb, flow);
	case FLOW_KEY_RTCLASSID:
		return flow_get_rtclassid(skb);
	case FLOW_KEY_SKUID:
		return flow_get_skuid(skb);
	case FLOW_KEY_SKGID:
		return flow_get_skgid(skb);
	case FLOW_KEY_VLAN_TAG:
		return flow_get_vlan_tag(skb);
	case FLOW_KEY_RXHASH:
		return flow_get_rxhash(skb);
	default:
		WARN_ON(1);
		return 0;
	}
}

#define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | 		\
			  (1 << FLOW_KEY_DST) |			\
			  (1 << FLOW_KEY_PROTO) |		\
			  (1 << FLOW_KEY_PROTO_SRC) |		\
			  (1 << FLOW_KEY_PROTO_DST) | 		\
			  (1 << FLOW_KEY_NFCT_SRC) |		\
			  (1 << FLOW_KEY_NFCT_DST) |		\
			  (1 << FLOW_KEY_NFCT_PROTO_SRC) |	\
			  (1 << FLOW_KEY_NFCT_PROTO_DST))

static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
			 struct tcf_result *res)
{
	struct flow_head *head = tp->root;
	struct flow_filter *f;
	u32 keymask;
	u32 classid;
	unsigned int n, key;
	int r;

	list_for_each_entry(f, &head->filters, list) {
		u32 keys[FLOW_KEY_MAX + 1];
		struct flow_keys flow_keys;

		if (!tcf_em_tree_match(skb, &f->ematches, NULL))
			continue;

		keymask = f->keymask;
		if (keymask & FLOW_KEYS_NEEDED)
			skb_flow_dissect(skb, &flow_keys);

		for (n = 0; n < f->nkeys; n++) {
			key = ffs(keymask) - 1;
			keymask &= ~(1 << key);
			keys[n] = flow_key_get(skb, key, &flow_keys);
		}

		if (f->mode == FLOW_MODE_HASH)
			classid = jhash2(keys, f->nkeys, f->hashrnd);
		else {
			classid = keys[0];
			classid = (classid & f->mask) ^ f->xor;
			classid = (classid >> f->rshift) + f->addend;
		}

		if (f->divisor)
			classid %= f->divisor;

		res->class   = 0;
		res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);

		r = tcf_exts_exec(skb, &f->exts, res);
		if (r < 0)
			continue;
		return r;
	}
	return -1;
}

static void flow_perturbation(unsigned long arg)
{
	struct flow_filter *f = (struct flow_filter *)arg;

	get_random_bytes(&f->hashrnd, 4);
	if (f->perturb_period)
		mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
}

static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
	[TCA_FLOW_KEYS]		= { .type = NLA_U32 },
	[TCA_FLOW_MODE]		= { .type = NLA_U32 },
	[TCA_FLOW_BASECLASS]	= { .type = NLA_U32 },
	[TCA_FLOW_RSHIFT]	= { .type = NLA_U32 },
	[TCA_FLOW_ADDEND]	= { .type = NLA_U32 },
	[TCA_FLOW_MASK]		= { .type = NLA_U32 },
	[TCA_FLOW_XOR]		= { .type = NLA_U32 },
	[TCA_FLOW_DIVISOR]	= { .type = NLA_U32 },
	[TCA_FLOW_ACT]		= { .type = NLA_NESTED },
	[TCA_FLOW_POLICE]	= { .type = NLA_NESTED },
	[TCA_FLOW_EMATCHES]	= { .type = NLA_NESTED },
	[TCA_FLOW_PERTURB]	= { .type = NLA_U32 },
};

static int flow_change(struct net *net, struct sk_buff *in_skb,
		       struct tcf_proto *tp, unsigned long base,
		       u32 handle, struct nlattr **tca,
		       unsigned long *arg)
{
	struct flow_head *head = tp->root;
	struct flow_filter *f;
	struct nlattr *opt = tca[TCA_OPTIONS];
	struct nlattr *tb[TCA_FLOW_MAX + 1];
	struct tcf_exts e;
	struct tcf_ematch_tree t;
	unsigned int nkeys = 0;
	unsigned int perturb_period = 0;
	u32 baseclass = 0;
	u32 keymask = 0;
	u32 mode;
	int err;

	if (opt == NULL)
		return -EINVAL;

	err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
	if (err < 0)
		return err;

	if (tb[TCA_FLOW_BASECLASS]) {
		baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
		if (TC_H_MIN(baseclass) == 0)
			return -EINVAL;
	}

	if (tb[TCA_FLOW_KEYS]) {
		keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);

		nkeys = hweight32(keymask);
		if (nkeys == 0)
			return -EINVAL;

		if (fls(keymask) - 1 > FLOW_KEY_MAX)
			return -EOPNOTSUPP;

		if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) &&
		    sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
			return -EOPNOTSUPP;
	}

	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
	if (err < 0)
		return err;

	err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
	if (err < 0)
		goto err1;

	f = (struct flow_filter *)*arg;
	if (f != NULL) {
		err = -EINVAL;
		if (f->handle != handle && handle)
			goto err2;

		mode = f->mode;
		if (tb[TCA_FLOW_MODE])
			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
		if (mode != FLOW_MODE_HASH && nkeys > 1)
			goto err2;

		if (mode == FLOW_MODE_HASH)
			perturb_period = f->perturb_period;
		if (tb[TCA_FLOW_PERTURB]) {
			if (mode != FLOW_MODE_HASH)
				goto err2;
			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
		}
	} else {
		err = -EINVAL;
		if (!handle)
			goto err2;
		if (!tb[TCA_FLOW_KEYS])
			goto err2;

		mode = FLOW_MODE_MAP;
		if (tb[TCA_FLOW_MODE])
			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
		if (mode != FLOW_MODE_HASH && nkeys > 1)
			goto err2;

		if (tb[TCA_FLOW_PERTURB]) {
			if (mode != FLOW_MODE_HASH)
				goto err2;
			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
		}

		if (TC_H_MAJ(baseclass) == 0)
			baseclass = TC_H_MAKE(tp->q->handle, baseclass);
		if (TC_H_MIN(baseclass) == 0)
			baseclass = TC_H_MAKE(baseclass, 1);

		err = -ENOBUFS;
		f = kzalloc(sizeof(*f), GFP_KERNEL);
		if (f == NULL)
			goto err2;

		f->handle = handle;
		f->mask	  = ~0U;
		tcf_exts_init(&f->exts);

		get_random_bytes(&f->hashrnd, 4);
		f->perturb_timer.function = flow_perturbation;
		f->perturb_timer.data = (unsigned long)f;
		init_timer_deferrable(&f->perturb_timer);
	}

	tcf_exts_change(tp, &f->exts, &e);
	tcf_em_tree_change(tp, &f->ematches, &t);

	tcf_tree_lock(tp);

	if (tb[TCA_FLOW_KEYS]) {
		f->keymask = keymask;
		f->nkeys   = nkeys;
	}

	f->mode = mode;

	if (tb[TCA_FLOW_MASK])
		f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
	if (tb[TCA_FLOW_XOR])
		f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
	if (tb[TCA_FLOW_RSHIFT])
		f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
	if (tb[TCA_FLOW_ADDEND])
		f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);

	if (tb[TCA_FLOW_DIVISOR])
		f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
	if (baseclass)
		f->baseclass = baseclass;

	f->perturb_period = perturb_period;
	del_timer(&f->perturb_timer);
	if (perturb_period)
		mod_timer(&f->perturb_timer, jiffies + perturb_period);

	if (*arg == 0)
		list_add_tail(&f->list, &head->filters);

	tcf_tree_unlock(tp);

	*arg = (unsigned long)f;
	return 0;

err2:
	tcf_em_tree_destroy(tp, &t);
err1:
	tcf_exts_destroy(tp, &e);
	return err;
}

static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
{
	del_timer_sync(&f->perturb_timer);
	tcf_exts_destroy(tp, &f->exts);
	tcf_em_tree_destroy(tp, &f->ematches);
	kfree(f);
}

static int flow_delete(struct tcf_proto *tp, unsigned long arg)
{
	struct flow_filter *f = (struct flow_filter *)arg;

	tcf_tree_lock(tp);
	list_del(&f->list);
	tcf_tree_unlock(tp);
	flow_destroy_filter(tp, f);
	return 0;
}

static int flow_init(struct tcf_proto *tp)
{
	struct flow_head *head;

	head = kzalloc(sizeof(*head), GFP_KERNEL);
	if (head == NULL)
		return -ENOBUFS;
	INIT_LIST_HEAD(&head->filters);
	tp->root = head;
	return 0;
}

static void flow_destroy(struct tcf_proto *tp)
{
	struct flow_head *head = tp->root;
	struct flow_filter *f, *next;

	list_for_each_entry_safe(f, next, &head->filters, list) {
		list_del(&f->list);
		flow_destroy_filter(tp, f);
	}
	kfree(head);
}

static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
{
	struct flow_head *head = tp->root;
	struct flow_filter *f;

	list_for_each_entry(f, &head->filters, list)
		if (f->handle == handle)
			return (unsigned long)f;
	return 0;
}

static void flow_put(struct tcf_proto *tp, unsigned long f)
{
}

static int flow_dump(struct tcf_proto *tp, unsigned long fh,
		     struct sk_buff *skb, struct tcmsg *t)
{
	struct flow_filter *f = (struct flow_filter *)fh;
	struct nlattr *nest;

	if (f == NULL)
		return skb->len;

	t->tcm_handle = f->handle;

	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;

	if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
	    nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
		goto nla_put_failure;

	if (f->mask != ~0 || f->xor != 0) {
		if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
		    nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
			goto nla_put_failure;
	}
	if (f->rshift &&
	    nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
		goto nla_put_failure;
	if (f->addend &&
	    nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
		goto nla_put_failure;

	if (f->divisor &&
	    nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
		goto nla_put_failure;
	if (f->baseclass &&
	    nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
		goto nla_put_failure;

	if (f->perturb_period &&
	    nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
		goto nla_put_failure;

	if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
		goto nla_put_failure;
#ifdef CONFIG_NET_EMATCH
	if (f->ematches.hdr.nmatches &&
	    tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
		goto nla_put_failure;
#endif
	nla_nest_end(skb, nest);

	if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
		goto nla_put_failure;

	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, nest);
	return -1;
}

static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
	struct flow_head *head = tp->root;
	struct flow_filter *f;

	list_for_each_entry(f, &head->filters, list) {
		if (arg->count < arg->skip)
			goto skip;
		if (arg->fn(tp, (unsigned long)f, arg) < 0) {
			arg->stop = 1;
			break;
		}
skip:
		arg->count++;
	}
}

static struct tcf_proto_ops cls_flow_ops __read_mostly = {
	.kind		= "flow",
	.classify	= flow_classify,
	.init		= flow_init,
	.destroy	= flow_destroy,
	.change		= flow_change,
	.delete		= flow_delete,
	.get		= flow_get,
	.put		= flow_put,
	.dump		= flow_dump,
	.walk		= flow_walk,
	.owner		= THIS_MODULE,
};

static int __init cls_flow_init(void)
{
	return register_tcf_proto_ops(&cls_flow_ops);
}

static void __exit cls_flow_exit(void)
{
	unregister_tcf_proto_ops(&cls_flow_ops);
}

module_init(cls_flow_init);
module_exit(cls_flow_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("TC flow classifier");
Commit	Line	Data
e5dfb815 PM	1	/*
	2	* net/sched/cls_flow.c Generic flow classifier
	3	*
	4	* Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version 2
	9	* of the License, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/kernel.h>
	13	#include <linux/init.h>
	14	#include <linux/list.h>
	15	#include <linux/jhash.h>
	16	#include <linux/random.h>
	17	#include <linux/pkt_cls.h>
	18	#include <linux/skbuff.h>
	19	#include <linux/in.h>
	20	#include <linux/ip.h>
	21	#include <linux/ipv6.h>
9ec13810	22	#include <linux/if_vlan.h>
5a0e3ad6	23	#include <linux/slab.h>
3a9a231d	24	#include <linux/module.h>
e5dfb815 PM	25
	26	#include <net/pkt_cls.h>
	27	#include <net/ip.h>
	28	#include <net/route.h>
6bd2a9af ED	29	#include <net/flow_keys.h>
6bd2a9af ED	30
e5dfb815 PM	31	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
	32	#include <net/netfilter/nf_conntrack.h>
	33	#endif
	34
	35	struct flow_head {
	36	struct list_head filters;
	37	};
	38
	39	struct flow_filter {
	40	struct list_head list;
	41	struct tcf_exts exts;
	42	struct tcf_ematch_tree ematches;
72d9794f PM	43	struct timer_list perturb_timer;
72d9794f PM	44	u32 perturb_period;
e5dfb815 PM	45	u32 handle;
	46
	47	u32 nkeys;
	48	u32 keymask;
	49	u32 mode;
	50	u32 mask;
	51	u32 xor;
	52	u32 rshift;
	53	u32 addend;
	54	u32 divisor;
	55	u32 baseclass;
72d9794f	56	u32 hashrnd;
e5dfb815 PM	57	};
e5dfb815 PM	58
e5dfb815 PM	59	static const struct tcf_ext_map flow_ext_map = {
	60	.action = TCA_FLOW_ACT,
	61	.police = TCA_FLOW_POLICE,
	62	};
	63
	64	static inline u32 addr_fold(void *addr)
	65	{
	66	unsigned long a = (unsigned long)addr;
	67
	68	return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
	69	}
	70
6bd2a9af	71	static u32 flow_get_src(const struct sk_buff skb, const struct flow_keys flow)
e5dfb815	72	{
6bd2a9af ED	73	if (flow->src)
6bd2a9af ED	74	return ntohl(flow->src);
4b95c3d4	75	return addr_fold(skb->sk);
e5dfb815 PM	76	}
e5dfb815 PM	77
6bd2a9af	78	static u32 flow_get_dst(const struct sk_buff skb, const struct flow_keys flow)
e5dfb815	79	{
6bd2a9af ED	80	if (flow->dst)
6bd2a9af ED	81	return ntohl(flow->dst);
4b95c3d4	82	return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
e5dfb815 PM	83	}
e5dfb815 PM	84
6bd2a9af	85	static u32 flow_get_proto(const struct sk_buff skb, const struct flow_keys flow)
e5dfb815	86	{
6bd2a9af	87	return flow->ip_proto;
e5dfb815 PM	88	}
e5dfb815 PM	89
6bd2a9af	90	static u32 flow_get_proto_src(const struct sk_buff skb, const struct flow_keys flow)
e5dfb815	91	{
6bd2a9af ED	92	if (flow->ports)
6bd2a9af ED	93	return ntohs(flow->port16[0]);
e5dfb815	94
859c2012 ED	95	return addr_fold(skb->sk);
	96	}
	97
6bd2a9af	98	static u32 flow_get_proto_dst(const struct sk_buff skb, const struct flow_keys flow)
859c2012	99	{
6bd2a9af ED	100	if (flow->ports)
6bd2a9af ED	101	return ntohs(flow->port16[1]);
e5dfb815	102
4b95c3d4	103	return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
e5dfb815 PM	104	}
	105
	106	static u32 flow_get_iif(const struct sk_buff *skb)
	107	{
8964be4a	108	return skb->skb_iif;
e5dfb815 PM	109	}
	110
	111	static u32 flow_get_priority(const struct sk_buff *skb)
	112	{
	113	return skb->priority;
	114	}
	115
	116	static u32 flow_get_mark(const struct sk_buff *skb)
	117	{
	118	return skb->mark;
	119	}
	120
	121	static u32 flow_get_nfct(const struct sk_buff *skb)
	122	{
	123	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
	124	return addr_fold(skb->nfct);
	125	#else
	126	return 0;
	127	#endif
	128	}
	129
	130	#if defined(CONFIG_NF_CONNTRACK) \|\| defined(CONFIG_NF_CONNTRACK_MODULE)
	131	#define CTTUPLE(skb, member) \
	132	({ \
	133	enum ip_conntrack_info ctinfo; \
859c2012	134	const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \
e5dfb815 PM	135	if (ct == NULL) \
	136	goto fallback; \
	137	ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \
	138	})
	139	#else
	140	#define CTTUPLE(skb, member) \
	141	({ \
	142	goto fallback; \
	143	0; \
	144	})
	145	#endif
	146
6bd2a9af	147	static u32 flow_get_nfct_src(const struct sk_buff skb, const struct flow_keys flow)
e5dfb815 PM	148	{
e5dfb815 PM	149	switch (skb->protocol) {
60678040	150	case htons(ETH_P_IP):
e5dfb815	151	return ntohl(CTTUPLE(skb, src.u3.ip));
60678040	152	case htons(ETH_P_IPV6):
e5dfb815 PM	153	return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
	154	}
	155	fallback:
6bd2a9af	156	return flow_get_src(skb, flow);
e5dfb815 PM	157	}
e5dfb815 PM	158
6bd2a9af	159	static u32 flow_get_nfct_dst(const struct sk_buff skb, const struct flow_keys flow)
e5dfb815 PM	160	{
e5dfb815 PM	161	switch (skb->protocol) {
60678040	162	case htons(ETH_P_IP):
e5dfb815	163	return ntohl(CTTUPLE(skb, dst.u3.ip));
60678040	164	case htons(ETH_P_IPV6):
e5dfb815 PM	165	return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
	166	}
	167	fallback:
6bd2a9af	168	return flow_get_dst(skb, flow);
e5dfb815 PM	169	}
e5dfb815 PM	170
6bd2a9af	171	static u32 flow_get_nfct_proto_src(const struct sk_buff skb, const struct flow_keys flow)
e5dfb815 PM	172	{
	173	return ntohs(CTTUPLE(skb, src.u.all));
	174	fallback:
6bd2a9af	175	return flow_get_proto_src(skb, flow);
e5dfb815 PM	176	}
e5dfb815 PM	177
6bd2a9af	178	static u32 flow_get_nfct_proto_dst(const struct sk_buff skb, const struct flow_keys flow)
e5dfb815 PM	179	{
	180	return ntohs(CTTUPLE(skb, dst.u.all));
	181	fallback:
6bd2a9af	182	return flow_get_proto_dst(skb, flow);
e5dfb815 PM	183	}
	184
	185	static u32 flow_get_rtclassid(const struct sk_buff *skb)
	186	{
c7066f70	187	#ifdef CONFIG_IP_ROUTE_CLASSID
adf30907 ED	188	if (skb_dst(skb))
adf30907 ED	189	return skb_dst(skb)->tclassid;
e5dfb815 PM	190	#endif
	191	return 0;
	192	}
	193
	194	static u32 flow_get_skuid(const struct sk_buff *skb)
	195	{
a6c6796c EB	196	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
	197	kuid_t skuid = skb->sk->sk_socket->file->f_cred->fsuid;
	198	return from_kuid(&init_user_ns, skuid);
	199	}
e5dfb815 PM	200	return 0;
	201	}
	202
	203	static u32 flow_get_skgid(const struct sk_buff *skb)
	204	{
a6c6796c EB	205	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
	206	kgid_t skgid = skb->sk->sk_socket->file->f_cred->fsgid;
	207	return from_kgid(&init_user_ns, skgid);
	208	}
e5dfb815 PM	209	return 0;
	210	}
	211
9ec13810 PM	212	static u32 flow_get_vlan_tag(const struct sk_buff *skb)
	213	{
	214	u16 uninitialized_var(tag);
	215
	216	if (vlan_get_tag(skb, &tag) < 0)
	217	return 0;
	218	return tag & VLAN_VID_MASK;
	219	}
	220
739a91ef CG	221	static u32 flow_get_rxhash(struct sk_buff *skb)
739a91ef CG	222	{
3958afa1	223	return skb_get_hash(skb);
739a91ef CG	224	}
739a91ef CG	225
6bd2a9af	226	static u32 flow_key_get(struct sk_buff skb, int key, struct flow_keys flow)
e5dfb815 PM	227	{
	228	switch (key) {
	229	case FLOW_KEY_SRC:
6bd2a9af	230	return flow_get_src(skb, flow);
e5dfb815	231	case FLOW_KEY_DST:
6bd2a9af	232	return flow_get_dst(skb, flow);
e5dfb815	233	case FLOW_KEY_PROTO:
6bd2a9af	234	return flow_get_proto(skb, flow);
e5dfb815	235	case FLOW_KEY_PROTO_SRC:
6bd2a9af	236	return flow_get_proto_src(skb, flow);
e5dfb815	237	case FLOW_KEY_PROTO_DST:
6bd2a9af	238	return flow_get_proto_dst(skb, flow);
e5dfb815 PM	239	case FLOW_KEY_IIF:
	240	return flow_get_iif(skb);
	241	case FLOW_KEY_PRIORITY:
	242	return flow_get_priority(skb);
	243	case FLOW_KEY_MARK:
	244	return flow_get_mark(skb);
	245	case FLOW_KEY_NFCT:
	246	return flow_get_nfct(skb);
	247	case FLOW_KEY_NFCT_SRC:
6bd2a9af	248	return flow_get_nfct_src(skb, flow);
e5dfb815	249	case FLOW_KEY_NFCT_DST:
6bd2a9af	250	return flow_get_nfct_dst(skb, flow);
e5dfb815	251	case FLOW_KEY_NFCT_PROTO_SRC:
6bd2a9af	252	return flow_get_nfct_proto_src(skb, flow);
e5dfb815	253	case FLOW_KEY_NFCT_PROTO_DST:
6bd2a9af	254	return flow_get_nfct_proto_dst(skb, flow);
e5dfb815 PM	255	case FLOW_KEY_RTCLASSID:
	256	return flow_get_rtclassid(skb);
	257	case FLOW_KEY_SKUID:
	258	return flow_get_skuid(skb);
	259	case FLOW_KEY_SKGID:
	260	return flow_get_skgid(skb);
9ec13810 PM	261	case FLOW_KEY_VLAN_TAG:
9ec13810 PM	262	return flow_get_vlan_tag(skb);
739a91ef CG	263	case FLOW_KEY_RXHASH:
739a91ef CG	264	return flow_get_rxhash(skb);
e5dfb815 PM	265	default:
	266	WARN_ON(1);
	267	return 0;
	268	}
	269	}
	270
6bd2a9af ED	271	#define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) \| \
	272	(1 << FLOW_KEY_DST) \| \
	273	(1 << FLOW_KEY_PROTO) \| \
	274	(1 << FLOW_KEY_PROTO_SRC) \| \
	275	(1 << FLOW_KEY_PROTO_DST) \| \
	276	(1 << FLOW_KEY_NFCT_SRC) \| \
	277	(1 << FLOW_KEY_NFCT_DST) \| \
	278	(1 << FLOW_KEY_NFCT_PROTO_SRC) \| \
	279	(1 << FLOW_KEY_NFCT_PROTO_DST))
	280
dc7f9f6e	281	static int flow_classify(struct sk_buff skb, const struct tcf_proto tp,
e5dfb815 PM	282	struct tcf_result *res)
	283	{
	284	struct flow_head *head = tp->root;
	285	struct flow_filter *f;
	286	u32 keymask;
	287	u32 classid;
	288	unsigned int n, key;
	289	int r;
	290
	291	list_for_each_entry(f, &head->filters, list) {
3a53943b	292	u32 keys[FLOW_KEY_MAX + 1];
6bd2a9af	293	struct flow_keys flow_keys;
e5dfb815 PM	294
	295	if (!tcf_em_tree_match(skb, &f->ematches, NULL))
	296	continue;
	297
	298	keymask = f->keymask;
6bd2a9af ED	299	if (keymask & FLOW_KEYS_NEEDED)
6bd2a9af ED	300	skb_flow_dissect(skb, &flow_keys);
e5dfb815 PM	301
	302	for (n = 0; n < f->nkeys; n++) {
	303	key = ffs(keymask) - 1;
	304	keymask &= ~(1 << key);
6bd2a9af	305	keys[n] = flow_key_get(skb, key, &flow_keys);
e5dfb815 PM	306	}
	307
	308	if (f->mode == FLOW_MODE_HASH)
72d9794f	309	classid = jhash2(keys, f->nkeys, f->hashrnd);
e5dfb815 PM	310	else {
	311	classid = keys[0];
	312	classid = (classid & f->mask) ^ f->xor;
	313	classid = (classid >> f->rshift) + f->addend;
	314	}
	315
	316	if (f->divisor)
	317	classid %= f->divisor;
	318
	319	res->class = 0;
	320	res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
	321
	322	r = tcf_exts_exec(skb, &f->exts, res);
	323	if (r < 0)
	324	continue;
	325	return r;
	326	}
	327	return -1;
	328	}
	329
72d9794f PM	330	static void flow_perturbation(unsigned long arg)
	331	{
	332	struct flow_filter f = (struct flow_filter )arg;
	333
	334	get_random_bytes(&f->hashrnd, 4);
	335	if (f->perturb_period)
	336	mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
	337	}
	338
e5dfb815 PM	339	static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
	340	[TCA_FLOW_KEYS] = { .type = NLA_U32 },
	341	[TCA_FLOW_MODE] = { .type = NLA_U32 },
	342	[TCA_FLOW_BASECLASS] = { .type = NLA_U32 },
	343	[TCA_FLOW_RSHIFT] = { .type = NLA_U32 },
	344	[TCA_FLOW_ADDEND] = { .type = NLA_U32 },
	345	[TCA_FLOW_MASK] = { .type = NLA_U32 },
	346	[TCA_FLOW_XOR] = { .type = NLA_U32 },
	347	[TCA_FLOW_DIVISOR] = { .type = NLA_U32 },
	348	[TCA_FLOW_ACT] = { .type = NLA_NESTED },
	349	[TCA_FLOW_POLICE] = { .type = NLA_NESTED },
	350	[TCA_FLOW_EMATCHES] = { .type = NLA_NESTED },
72d9794f	351	[TCA_FLOW_PERTURB] = { .type = NLA_U32 },
e5dfb815 PM	352	};
e5dfb815 PM	353
c1b52739	354	static int flow_change(struct net net, struct sk_buff in_skb,
af4c6641	355	struct tcf_proto *tp, unsigned long base,
e5dfb815 PM	356	u32 handle, struct nlattr **tca,
	357	unsigned long *arg)
	358	{
	359	struct flow_head *head = tp->root;
	360	struct flow_filter *f;
	361	struct nlattr *opt = tca[TCA_OPTIONS];
	362	struct nlattr *tb[TCA_FLOW_MAX + 1];
	363	struct tcf_exts e;
	364	struct tcf_ematch_tree t;
	365	unsigned int nkeys = 0;
72d9794f	366	unsigned int perturb_period = 0;
e5dfb815 PM	367	u32 baseclass = 0;
	368	u32 keymask = 0;
	369	u32 mode;
	370	int err;
	371
	372	if (opt == NULL)
	373	return -EINVAL;
	374
	375	err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
	376	if (err < 0)
	377	return err;
	378
	379	if (tb[TCA_FLOW_BASECLASS]) {
	380	baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
	381	if (TC_H_MIN(baseclass) == 0)
	382	return -EINVAL;
	383	}
	384
	385	if (tb[TCA_FLOW_KEYS]) {
	386	keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
e5dfb815 PM	387
	388	nkeys = hweight32(keymask);
	389	if (nkeys == 0)
	390	return -EINVAL;
4f250491 PM	391
	392	if (fls(keymask) - 1 > FLOW_KEY_MAX)
	393	return -EOPNOTSUPP;
a6c6796c EB	394
a6c6796c EB	395	if ((keymask & (FLOW_KEY_SKUID\|FLOW_KEY_SKGID)) &&
e32123e5	396	sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
a6c6796c	397	return -EOPNOTSUPP;
e5dfb815 PM	398	}
e5dfb815 PM	399
c1b52739	400	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
e5dfb815 PM	401	if (err < 0)
	402	return err;
	403
	404	err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
	405	if (err < 0)
	406	goto err1;
	407
	408	f = (struct flow_filter )arg;
	409	if (f != NULL) {
	410	err = -EINVAL;
	411	if (f->handle != handle && handle)
	412	goto err2;
	413
	414	mode = f->mode;
	415	if (tb[TCA_FLOW_MODE])
	416	mode = nla_get_u32(tb[TCA_FLOW_MODE]);
	417	if (mode != FLOW_MODE_HASH && nkeys > 1)
	418	goto err2;
72d9794f PM	419
	420	if (mode == FLOW_MODE_HASH)
	421	perturb_period = f->perturb_period;
	422	if (tb[TCA_FLOW_PERTURB]) {
	423	if (mode != FLOW_MODE_HASH)
	424	goto err2;
	425	perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
	426	}
e5dfb815 PM	427	} else {
	428	err = -EINVAL;
	429	if (!handle)
	430	goto err2;
	431	if (!tb[TCA_FLOW_KEYS])
	432	goto err2;
	433
	434	mode = FLOW_MODE_MAP;
	435	if (tb[TCA_FLOW_MODE])
	436	mode = nla_get_u32(tb[TCA_FLOW_MODE]);
	437	if (mode != FLOW_MODE_HASH && nkeys > 1)
	438	goto err2;
	439
72d9794f PM	440	if (tb[TCA_FLOW_PERTURB]) {
	441	if (mode != FLOW_MODE_HASH)
	442	goto err2;
	443	perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
	444	}
	445
e5dfb815 PM	446	if (TC_H_MAJ(baseclass) == 0)
	447	baseclass = TC_H_MAKE(tp->q->handle, baseclass);
	448	if (TC_H_MIN(baseclass) == 0)
	449	baseclass = TC_H_MAKE(baseclass, 1);
	450
	451	err = -ENOBUFS;
	452	f = kzalloc(sizeof(*f), GFP_KERNEL);
	453	if (f == NULL)
	454	goto err2;
	455
	456	f->handle = handle;
	457	f->mask = ~0U;
33be6271	458	tcf_exts_init(&f->exts);
72d9794f PM	459
	460	get_random_bytes(&f->hashrnd, 4);
	461	f->perturb_timer.function = flow_perturbation;
	462	f->perturb_timer.data = (unsigned long)f;
	463	init_timer_deferrable(&f->perturb_timer);
e5dfb815 PM	464	}
	465
	466	tcf_exts_change(tp, &f->exts, &e);
	467	tcf_em_tree_change(tp, &f->ematches, &t);
	468
	469	tcf_tree_lock(tp);
	470
	471	if (tb[TCA_FLOW_KEYS]) {
	472	f->keymask = keymask;
	473	f->nkeys = nkeys;
	474	}
	475
	476	f->mode = mode;
	477
	478	if (tb[TCA_FLOW_MASK])
	479	f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
	480	if (tb[TCA_FLOW_XOR])
	481	f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
	482	if (tb[TCA_FLOW_RSHIFT])
	483	f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
	484	if (tb[TCA_FLOW_ADDEND])
	485	f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
	486
	487	if (tb[TCA_FLOW_DIVISOR])
	488	f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
	489	if (baseclass)
	490	f->baseclass = baseclass;
	491
72d9794f PM	492	f->perturb_period = perturb_period;
	493	del_timer(&f->perturb_timer);
	494	if (perturb_period)
	495	mod_timer(&f->perturb_timer, jiffies + perturb_period);
	496
e5dfb815 PM	497	if (*arg == 0)
	498	list_add_tail(&f->list, &head->filters);
	499
	500	tcf_tree_unlock(tp);
	501
	502	*arg = (unsigned long)f;
	503	return 0;
	504
	505	err2:
	506	tcf_em_tree_destroy(tp, &t);
	507	err1:
	508	tcf_exts_destroy(tp, &e);
	509	return err;
	510	}
	511
	512	static void flow_destroy_filter(struct tcf_proto tp, struct flow_filter f)
	513	{
72d9794f	514	del_timer_sync(&f->perturb_timer);
e5dfb815 PM	515	tcf_exts_destroy(tp, &f->exts);
	516	tcf_em_tree_destroy(tp, &f->ematches);
	517	kfree(f);
	518	}
	519
	520	static int flow_delete(struct tcf_proto *tp, unsigned long arg)
	521	{
	522	struct flow_filter f = (struct flow_filter )arg;
	523
	524	tcf_tree_lock(tp);
	525	list_del(&f->list);
	526	tcf_tree_unlock(tp);
	527	flow_destroy_filter(tp, f);
	528	return 0;
	529	}
	530
	531	static int flow_init(struct tcf_proto *tp)
	532	{
	533	struct flow_head *head;
	534
e5dfb815 PM	535	head = kzalloc(sizeof(*head), GFP_KERNEL);
	536	if (head == NULL)
	537	return -ENOBUFS;
	538	INIT_LIST_HEAD(&head->filters);
	539	tp->root = head;
	540	return 0;
	541	}
	542
	543	static void flow_destroy(struct tcf_proto *tp)
	544	{
	545	struct flow_head *head = tp->root;
	546	struct flow_filter f, next;
	547
	548	list_for_each_entry_safe(f, next, &head->filters, list) {
	549	list_del(&f->list);
	550	flow_destroy_filter(tp, f);
	551	}
	552	kfree(head);
	553	}
	554
	555	static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
	556	{
	557	struct flow_head *head = tp->root;
	558	struct flow_filter *f;
	559
	560	list_for_each_entry(f, &head->filters, list)
	561	if (f->handle == handle)
	562	return (unsigned long)f;
	563	return 0;
	564	}
	565
	566	static void flow_put(struct tcf_proto *tp, unsigned long f)
	567	{
e5dfb815 PM	568	}
	569
	570	static int flow_dump(struct tcf_proto *tp, unsigned long fh,
	571	struct sk_buff skb, struct tcmsg t)
	572	{
	573	struct flow_filter f = (struct flow_filter )fh;
	574	struct nlattr *nest;
	575
	576	if (f == NULL)
	577	return skb->len;
	578
	579	t->tcm_handle = f->handle;
	580
	581	nest = nla_nest_start(skb, TCA_OPTIONS);
	582	if (nest == NULL)
	583	goto nla_put_failure;
	584
1b34ec43 DM	585	if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) \|\|
	586	nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
	587	goto nla_put_failure;
e5dfb815 PM	588
e5dfb815 PM	589	if (f->mask != ~0 \|\| f->xor != 0) {
1b34ec43 DM	590	if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) \|\|
	591	nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
	592	goto nla_put_failure;
e5dfb815	593	}
1b34ec43 DM	594	if (f->rshift &&
	595	nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
	596	goto nla_put_failure;
	597	if (f->addend &&
	598	nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
	599	goto nla_put_failure;
e5dfb815	600
1b34ec43 DM	601	if (f->divisor &&
	602	nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
	603	goto nla_put_failure;
	604	if (f->baseclass &&
	605	nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
	606	goto nla_put_failure;
e5dfb815	607
1b34ec43 DM	608	if (f->perturb_period &&
	609	nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
	610	goto nla_put_failure;
72d9794f	611
e5dfb815 PM	612	if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
e5dfb815 PM	613	goto nla_put_failure;
0aead543	614	#ifdef CONFIG_NET_EMATCH
e5dfb815 PM	615	if (f->ematches.hdr.nmatches &&
	616	tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
	617	goto nla_put_failure;
0aead543	618	#endif
e5dfb815 PM	619	nla_nest_end(skb, nest);
	620
	621	if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
	622	goto nla_put_failure;
	623
	624	return skb->len;
	625
	626	nla_put_failure:
	627	nlmsg_trim(skb, nest);
	628	return -1;
	629	}
	630
	631	static void flow_walk(struct tcf_proto tp, struct tcf_walker arg)
	632	{
	633	struct flow_head *head = tp->root;
	634	struct flow_filter *f;
	635
	636	list_for_each_entry(f, &head->filters, list) {
	637	if (arg->count < arg->skip)
	638	goto skip;
	639	if (arg->fn(tp, (unsigned long)f, arg) < 0) {
	640	arg->stop = 1;
	641	break;
	642	}
	643	skip:
	644	arg->count++;
	645	}
	646	}
	647
	648	static struct tcf_proto_ops cls_flow_ops __read_mostly = {
	649	.kind = "flow",
	650	.classify = flow_classify,
	651	.init = flow_init,
	652	.destroy = flow_destroy,
	653	.change = flow_change,
	654	.delete = flow_delete,
	655	.get = flow_get,
	656	.put = flow_put,
	657	.dump = flow_dump,
	658	.walk = flow_walk,
	659	.owner = THIS_MODULE,
	660	};
	661
	662	static int __init cls_flow_init(void)
	663	{
	664	return register_tcf_proto_ops(&cls_flow_ops);
	665	}
	666
	667	static void __exit cls_flow_exit(void)
	668	{
	669	unregister_tcf_proto_ops(&cls_flow_ops);
	670	}
	671
	672	module_init(cls_flow_init);
	673	module_exit(cls_flow_exit);
	674
	675	MODULE_LICENSE("GPL");
	676	MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
	677	MODULE_DESCRIPTION("TC flow classifier");