[linux.git] / net / sched / cls_api.c

/*
 * net/sched/cls_api.c	Packet classifier API.
 *
 *		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.
 *
 * Authors:	Alexey Kuznetsov, <[email protected]>
 *
 * Changes:
 *
 * Eduardo J. Blanco <[email protected]> :990222: kmod support
 *
 */

#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>

#if 0 /* control */
#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define DPRINTK(format,args...)
#endif

/* The list of all installed classifier types */

static struct tcf_proto_ops *tcf_proto_base;

/* Protects list of registered TC modules. It is pure SMP lock. */
static DEFINE_RWLOCK(cls_mod_lock);

/* Find classifier type by string name */

static struct tcf_proto_ops * tcf_proto_lookup_ops(struct rtattr *kind)
{
	struct tcf_proto_ops *t = NULL;

	if (kind) {
		read_lock(&cls_mod_lock);
		for (t = tcf_proto_base; t; t = t->next) {
			if (rtattr_strcmp(kind, t->kind) == 0) {
				if (!try_module_get(t->owner))
					t = NULL;
				break;
			}
		}
		read_unlock(&cls_mod_lock);
	}
	return t;
}

/* Register(unregister) new classifier type */

int register_tcf_proto_ops(struct tcf_proto_ops *ops)
{
	struct tcf_proto_ops *t, **tp;
	int rc = -EEXIST;

	write_lock(&cls_mod_lock);
	for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
		if (!strcmp(ops->kind, t->kind))
			goto out;

	ops->next = NULL;
	*tp = ops;
	rc = 0;
out:
	write_unlock(&cls_mod_lock);
	return rc;
}

int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
{
	struct tcf_proto_ops *t, **tp;
	int rc = -ENOENT;

	write_lock(&cls_mod_lock);
	for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next)
		if (t == ops)
			break;

	if (!t)
		goto out;
	*tp = t->next;
	rc = 0;
out:
	write_unlock(&cls_mod_lock);
	return rc;
}

static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
			  struct tcf_proto *tp, unsigned long fh, int event);


/* Select new prio value from the range, managed by kernel. */

static __inline__ u32 tcf_auto_prio(struct tcf_proto *tp)
{
	u32 first = TC_H_MAKE(0xC0000000U,0U);

	if (tp)
		first = tp->prio-1;

	return first;
}

/* Add/change/delete/get a filter node */

static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
{
	struct rtattr **tca;
	struct tcmsg *t;
	u32 protocol;
	u32 prio;
	u32 nprio;
	u32 parent;
	struct net_device *dev;
	struct Qdisc  *q;
	struct tcf_proto **back, **chain;
	struct tcf_proto *tp;
	struct tcf_proto_ops *tp_ops;
	struct Qdisc_class_ops *cops;
	unsigned long cl;
	unsigned long fh;
	int err;

replay:
	tca = arg;
	t = NLMSG_DATA(n);
	protocol = TC_H_MIN(t->tcm_info);
	prio = TC_H_MAJ(t->tcm_info);
	nprio = prio;
	parent = t->tcm_parent;
	cl = 0;

	if (prio == 0) {
		/* If no priority is given, user wants we allocated it. */
		if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
			return -ENOENT;
		prio = TC_H_MAKE(0x80000000U,0U);
	}

	/* Find head of filter chain. */

	/* Find link */
	if ((dev = __dev_get_by_index(t->tcm_ifindex)) == NULL)
		return -ENODEV;

	/* Find qdisc */
	if (!parent) {
		q = dev->qdisc_sleeping;
		parent = q->handle;
	} else if ((q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent))) == NULL)
		return -EINVAL;

	/* Is it classful? */
	if ((cops = q->ops->cl_ops) == NULL)
		return -EINVAL;

	/* Do we search for filter, attached to class? */
	if (TC_H_MIN(parent)) {
		cl = cops->get(q, parent);
		if (cl == 0)
			return -ENOENT;
	}

	/* And the last stroke */
	chain = cops->tcf_chain(q, cl);
	err = -EINVAL;
	if (chain == NULL)
		goto errout;

	/* Check the chain for existence of proto-tcf with this priority */
	for (back = chain; (tp=*back) != NULL; back = &tp->next) {
		if (tp->prio >= prio) {
			if (tp->prio == prio) {
				if (!nprio || (tp->protocol != protocol && protocol))
					goto errout;
			} else
				tp = NULL;
			break;
		}
	}

	if (tp == NULL) {
		/* Proto-tcf does not exist, create new one */

		if (tca[TCA_KIND-1] == NULL || !protocol)
			goto errout;

		err = -ENOENT;
		if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
			goto errout;


		/* Create new proto tcf */

		err = -ENOBUFS;
		if ((tp = kmalloc(sizeof(*tp), GFP_KERNEL)) == NULL)
			goto errout;
		err = -EINVAL;
		tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]);
		if (tp_ops == NULL) {
#ifdef CONFIG_KMOD
			struct rtattr *kind = tca[TCA_KIND-1];
			char name[IFNAMSIZ];

			if (kind != NULL &&
			    rtattr_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
				rtnl_unlock();
				request_module("cls_%s", name);
				rtnl_lock();
				tp_ops = tcf_proto_lookup_ops(kind);
				/* We dropped the RTNL semaphore in order to
				 * perform the module load.  So, even if we
				 * succeeded in loading the module we have to
				 * replay the request.  We indicate this using
				 * -EAGAIN.
				 */
				if (tp_ops != NULL) {
					module_put(tp_ops->owner);
					err = -EAGAIN;
				}
			}
#endif
			kfree(tp);
			goto errout;
		}
		memset(tp, 0, sizeof(*tp));
		tp->ops = tp_ops;
		tp->protocol = protocol;
		tp->prio = nprio ? : tcf_auto_prio(*back);
		tp->q = q;
		tp->classify = tp_ops->classify;
		tp->classid = parent;
		if ((err = tp_ops->init(tp)) != 0) {
			module_put(tp_ops->owner);
			kfree(tp);
			goto errout;
		}

		qdisc_lock_tree(dev);
		tp->next = *back;
		*back = tp;
		qdisc_unlock_tree(dev);

	} else if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], tp->ops->kind))
		goto errout;

	fh = tp->ops->get(tp, t->tcm_handle);

	if (fh == 0) {
		if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
			qdisc_lock_tree(dev);
			*back = tp->next;
			qdisc_unlock_tree(dev);

			tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
			tcf_destroy(tp);
			err = 0;
			goto errout;
		}

		err = -ENOENT;
		if (n->nlmsg_type != RTM_NEWTFILTER || !(n->nlmsg_flags&NLM_F_CREATE))
			goto errout;
	} else {
		switch (n->nlmsg_type) {
		case RTM_NEWTFILTER:	
			err = -EEXIST;
			if (n->nlmsg_flags&NLM_F_EXCL)
				goto errout;
			break;
		case RTM_DELTFILTER:
			err = tp->ops->delete(tp, fh);
			if (err == 0)
				tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
			goto errout;
		case RTM_GETTFILTER:
			err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
			goto errout;
		default:
			err = -EINVAL;
			goto errout;
		}
	}

	err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
	if (err == 0)
		tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);

errout:
	if (cl)
		cops->put(q, cl);
	if (err == -EAGAIN)
		/* Replay the request. */
		goto replay;
	return err;
}

static int
tcf_fill_node(struct sk_buff *skb, struct tcf_proto *tp, unsigned long fh,
	      u32 pid, u32 seq, u16 flags, int event)
{
	struct tcmsg *tcm;
	struct nlmsghdr  *nlh;
	unsigned char	 *b = skb->tail;

	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
	tcm = NLMSG_DATA(nlh);
	tcm->tcm_family = AF_UNSPEC;
	tcm->tcm__pad1 = 0;
	tcm->tcm__pad1 = 0;
	tcm->tcm_ifindex = tp->q->dev->ifindex;
	tcm->tcm_parent = tp->classid;
	tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
	RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind);
	tcm->tcm_handle = fh;
	if (RTM_DELTFILTER != event) {
		tcm->tcm_handle = 0;
		if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
			goto rtattr_failure;
	}
	nlh->nlmsg_len = skb->tail - b;
	return skb->len;

nlmsg_failure:
rtattr_failure:
	skb_trim(skb, b - skb->data);
	return -1;
}

static int tfilter_notify(struct sk_buff *oskb, struct nlmsghdr *n,
			  struct tcf_proto *tp, unsigned long fh, int event)
{
	struct sk_buff *skb;
	u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;

	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!skb)
		return -ENOBUFS;

	if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) {
		kfree_skb(skb);
		return -EINVAL;
	}

	return rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
}

struct tcf_dump_args
{
	struct tcf_walker w;
	struct sk_buff *skb;
	struct netlink_callback *cb;
};

static int tcf_node_dump(struct tcf_proto *tp, unsigned long n, struct tcf_walker *arg)
{
	struct tcf_dump_args *a = (void*)arg;

	return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid,
			     a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
}

static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
{
	int t;
	int s_t;
	struct net_device *dev;
	struct Qdisc *q;
	struct tcf_proto *tp, **chain;
	struct tcmsg *tcm = (struct tcmsg*)NLMSG_DATA(cb->nlh);
	unsigned long cl = 0;
	struct Qdisc_class_ops *cops;
	struct tcf_dump_args arg;

	if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
		return skb->len;
	if ((dev = dev_get_by_index(tcm->tcm_ifindex)) == NULL)
		return skb->len;

	read_lock(&qdisc_tree_lock);
	if (!tcm->tcm_parent)
		q = dev->qdisc_sleeping;
	else
		q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
	if (!q)
		goto out;
	if ((cops = q->ops->cl_ops) == NULL)
		goto errout;
	if (TC_H_MIN(tcm->tcm_parent)) {
		cl = cops->get(q, tcm->tcm_parent);
		if (cl == 0)
			goto errout;
	}
	chain = cops->tcf_chain(q, cl);
	if (chain == NULL)
		goto errout;

	s_t = cb->args[0];

	for (tp=*chain, t=0; tp; tp = tp->next, t++) {
		if (t < s_t) continue;
		if (TC_H_MAJ(tcm->tcm_info) &&
		    TC_H_MAJ(tcm->tcm_info) != tp->prio)
			continue;
		if (TC_H_MIN(tcm->tcm_info) &&
		    TC_H_MIN(tcm->tcm_info) != tp->protocol)
			continue;
		if (t > s_t)
			memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
		if (cb->args[1] == 0) {
			if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid,
					  cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER) <= 0) {
				break;
			}
			cb->args[1] = 1;
		}
		if (tp->ops->walk == NULL)
			continue;
		arg.w.fn = tcf_node_dump;
		arg.skb = skb;
		arg.cb = cb;
		arg.w.stop = 0;
		arg.w.skip = cb->args[1]-1;
		arg.w.count = 0;
		tp->ops->walk(tp, &arg.w);
		cb->args[1] = arg.w.count+1;
		if (arg.w.stop)
			break;
	}

	cb->args[0] = t;

errout:
	if (cl)
		cops->put(q, cl);
out:
	read_unlock(&qdisc_tree_lock);
	dev_put(dev);
	return skb->len;
}

void
tcf_exts_destroy(struct tcf_proto *tp, struct tcf_exts *exts)
{
#ifdef CONFIG_NET_CLS_ACT
	if (exts->action) {
		tcf_action_destroy(exts->action, TCA_ACT_UNBIND);
		exts->action = NULL;
	}
#elif defined CONFIG_NET_CLS_POLICE
	if (exts->police) {
		tcf_police_release(exts->police, TCA_ACT_UNBIND);
		exts->police = NULL;
	}
#endif
}


int
tcf_exts_validate(struct tcf_proto *tp, struct rtattr **tb,
	          struct rtattr *rate_tlv, struct tcf_exts *exts,
	          struct tcf_ext_map *map)
{
	memset(exts, 0, sizeof(*exts));
	
#ifdef CONFIG_NET_CLS_ACT
	{
		int err;
		struct tc_action *act;

		if (map->police && tb[map->police-1]) {
			act = tcf_action_init_1(tb[map->police-1], rate_tlv, "police",
				TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err);
			if (act == NULL)
				return err;

			act->type = TCA_OLD_COMPAT;
			exts->action = act;
		} else if (map->action && tb[map->action-1]) {
			act = tcf_action_init(tb[map->action-1], rate_tlv, NULL,
				TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err);
			if (act == NULL)
				return err;

			exts->action = act;
		}
	}
#elif defined CONFIG_NET_CLS_POLICE
	if (map->police && tb[map->police-1]) {
		struct tcf_police *p;
		
		p = tcf_police_locate(tb[map->police-1], rate_tlv);
		if (p == NULL)
			return -EINVAL;

		exts->police = p;
	} else if (map->action && tb[map->action-1])
		return -EOPNOTSUPP;
#else
	if ((map->action && tb[map->action-1]) ||
	    (map->police && tb[map->police-1]))
		return -EOPNOTSUPP;
#endif

	return 0;
}

void
tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
	        struct tcf_exts *src)
{
#ifdef CONFIG_NET_CLS_ACT
	if (src->action) {
		struct tc_action *act;
		tcf_tree_lock(tp);
		act = xchg(&dst->action, src->action);
		tcf_tree_unlock(tp);
		if (act)
			tcf_action_destroy(act, TCA_ACT_UNBIND);
	}
#elif defined CONFIG_NET_CLS_POLICE
	if (src->police) {
		struct tcf_police *p;
		tcf_tree_lock(tp);
		p = xchg(&dst->police, src->police);
		tcf_tree_unlock(tp);
		if (p)
			tcf_police_release(p, TCA_ACT_UNBIND);
	}
#endif
}

int
tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts,
	      struct tcf_ext_map *map)
{
#ifdef CONFIG_NET_CLS_ACT
	if (map->action && exts->action) {
		/*
		 * again for backward compatible mode - we want
		 * to work with both old and new modes of entering
		 * tc data even if iproute2  was newer - jhs
		 */
		struct rtattr * p_rta = (struct rtattr*) skb->tail;

		if (exts->action->type != TCA_OLD_COMPAT) {
			RTA_PUT(skb, map->action, 0, NULL);
			if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
				goto rtattr_failure;
			p_rta->rta_len = skb->tail - (u8*)p_rta;
		} else if (map->police) {
			RTA_PUT(skb, map->police, 0, NULL);
			if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
				goto rtattr_failure;
			p_rta->rta_len = skb->tail - (u8*)p_rta;
		}
	}
#elif defined CONFIG_NET_CLS_POLICE
	if (map->police && exts->police) {
		struct rtattr * p_rta = (struct rtattr*) skb->tail;

		RTA_PUT(skb, map->police, 0, NULL);

		if (tcf_police_dump(skb, exts->police) < 0)
			goto rtattr_failure;

		p_rta->rta_len = skb->tail - (u8*)p_rta;
	}
#endif
	return 0;
rtattr_failure: __attribute__ ((unused))
	return -1;
}

int
tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts,
	            struct tcf_ext_map *map)
{
#ifdef CONFIG_NET_CLS_ACT
	if (exts->action)
		if (tcf_action_copy_stats(skb, exts->action, 1) < 0)
			goto rtattr_failure;
#elif defined CONFIG_NET_CLS_POLICE
	if (exts->police)
		if (tcf_police_dump_stats(skb, exts->police) < 0)
			goto rtattr_failure;
#endif
	return 0;
rtattr_failure: __attribute__ ((unused))
	return -1;
}

static int __init tc_filter_init(void)
{
	struct rtnetlink_link *link_p = rtnetlink_links[PF_UNSPEC];

	/* Setup rtnetlink links. It is made here to avoid
	   exporting large number of public symbols.
	 */

	if (link_p) {
		link_p[RTM_NEWTFILTER-RTM_BASE].doit = tc_ctl_tfilter;
		link_p[RTM_DELTFILTER-RTM_BASE].doit = tc_ctl_tfilter;
		link_p[RTM_GETTFILTER-RTM_BASE].doit = tc_ctl_tfilter;
		link_p[RTM_GETTFILTER-RTM_BASE].dumpit = tc_dump_tfilter;
	}
	return 0;
}

subsys_initcall(tc_filter_init);

EXPORT_SYMBOL(register_tcf_proto_ops);
EXPORT_SYMBOL(unregister_tcf_proto_ops);
EXPORT_SYMBOL(tcf_exts_validate);
EXPORT_SYMBOL(tcf_exts_destroy);
EXPORT_SYMBOL(tcf_exts_change);
EXPORT_SYMBOL(tcf_exts_dump);
EXPORT_SYMBOL(tcf_exts_dump_stats);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* net/sched/cls_api.c Packet classifier API.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version
	7	* 2 of the License, or (at your option) any later version.
	8	*
	9	* Authors: Alexey Kuznetsov, <[email protected]>
	10	*
	11	* Changes:
	12	*
	13	* Eduardo J. Blanco <[email protected]> :990222: kmod support
	14	*
	15	*/
	16
	17	#include <asm/uaccess.h>
	18	#include <asm/system.h>
	19	#include <linux/bitops.h>
1da177e4 LT	20	#include <linux/module.h>
	21	#include <linux/types.h>
	22	#include <linux/kernel.h>
	23	#include <linux/sched.h>
	24	#include <linux/string.h>
	25	#include <linux/mm.h>
	26	#include <linux/socket.h>
	27	#include <linux/sockios.h>
	28	#include <linux/in.h>
	29	#include <linux/errno.h>
	30	#include <linux/interrupt.h>
	31	#include <linux/netdevice.h>
	32	#include <linux/skbuff.h>
	33	#include <linux/rtnetlink.h>
	34	#include <linux/init.h>
	35	#include <linux/kmod.h>
	36	#include <net/sock.h>
	37	#include <net/pkt_sched.h>
	38	#include <net/pkt_cls.h>
	39
	40	#if 0 /* control */
	41	#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
	42	#else
	43	#define DPRINTK(format,args...)
	44	#endif
	45
	46	/* The list of all installed classifier types */
	47
	48	static struct tcf_proto_ops *tcf_proto_base;
	49
	50	/* Protects list of registered TC modules. It is pure SMP lock. */
	51	static DEFINE_RWLOCK(cls_mod_lock);
	52
	53	/* Find classifier type by string name */
	54
	55	static struct tcf_proto_ops * tcf_proto_lookup_ops(struct rtattr *kind)
	56	{
	57	struct tcf_proto_ops *t = NULL;
	58
	59	if (kind) {
	60	read_lock(&cls_mod_lock);
	61	for (t = tcf_proto_base; t; t = t->next) {
	62	if (rtattr_strcmp(kind, t->kind) == 0) {
	63	if (!try_module_get(t->owner))
	64	t = NULL;
	65	break;
	66	}
	67	}
	68	read_unlock(&cls_mod_lock);
	69	}
	70	return t;
	71	}
	72
	73	/* Register(unregister) new classifier type */
	74
	75	int register_tcf_proto_ops(struct tcf_proto_ops *ops)
	76	{
	77	struct tcf_proto_ops t, *tp;
	78	int rc = -EEXIST;
	79
	80	write_lock(&cls_mod_lock);
	81	for (tp = &tcf_proto_base; (t = *tp) != NULL; tp = &t->next)
	82	if (!strcmp(ops->kind, t->kind))
	83	goto out;
84
85	ops->next = NULL;
86	*tp = ops;
87	rc = 0;
88	out:
89	write_unlock(&cls_mod_lock);
90	return rc;
91	}
92
93	int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
94	{
95	struct tcf_proto_ops t, *tp;
96	int rc = -ENOENT;
97
98	write_lock(&cls_mod_lock);
99	for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next)
100	if (t == ops)
101	break;
102
103	if (!t)
104	goto out;
105	*tp = t->next;
106	rc = 0;
107	out:
108	write_unlock(&cls_mod_lock);
109	return rc;
110	}
111
112	static int tfilter_notify(struct sk_buff oskb, struct nlmsghdr n,
113	struct tcf_proto *tp, unsigned long fh, int event);
114
115
116	/* Select new prio value from the range, managed by kernel. */
117
118	static __inline__ u32 tcf_auto_prio(struct tcf_proto *tp)
119	{
120	u32 first = TC_H_MAKE(0xC0000000U,0U);
121
122	if (tp)
123	first = tp->prio-1;
124
125	return first;
126	}
127
128	/* Add/change/delete/get a filter node */
129
130	static int tc_ctl_tfilter(struct sk_buff skb, struct nlmsghdr n, void *arg)
131	{
132	struct rtattr **tca;
133	struct tcmsg *t;
134	u32 protocol;
135	u32 prio;
136	u32 nprio;
137	u32 parent;
138	struct net_device *dev;
139	struct Qdisc *q;
140	struct tcf_proto back, chain;
141	struct tcf_proto *tp;
142	struct tcf_proto_ops *tp_ops;
143	struct Qdisc_class_ops *cops;
144	unsigned long cl;
145	unsigned long fh;
146	int err;
147
148	replay:
149	tca = arg;
150	t = NLMSG_DATA(n);
151	protocol = TC_H_MIN(t->tcm_info);
152	prio = TC_H_MAJ(t->tcm_info);
153	nprio = prio;
154	parent = t->tcm_parent;
155	cl = 0;
156
157	if (prio == 0) {
158	/* If no priority is given, user wants we allocated it. */
159	if (n->nlmsg_type != RTM_NEWTFILTER \|\| !(n->nlmsg_flags&NLM_F_CREATE))
160	return -ENOENT;
161	prio = TC_H_MAKE(0x80000000U,0U);
162	}
163
164	/* Find head of filter chain. */
165
166	/* Find link */
167	if ((dev = __dev_get_by_index(t->tcm_ifindex)) == NULL)
168	return -ENODEV;
169
170	/* Find qdisc */
171	if (!parent) {
172	q = dev->qdisc_sleeping;
173	parent = q->handle;
174	} else if ((q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent))) == NULL)
175	return -EINVAL;
176
177	/* Is it classful? */
178	if ((cops = q->ops->cl_ops) == NULL)
179	return -EINVAL;
180
181	/* Do we search for filter, attached to class? */
182	if (TC_H_MIN(parent)) {
183	cl = cops->get(q, parent);
184	if (cl == 0)
185	return -ENOENT;
186	}
187
188	/* And the last stroke */
189	chain = cops->tcf_chain(q, cl);
190	err = -EINVAL;
191	if (chain == NULL)
192	goto errout;
193
194	/* Check the chain for existence of proto-tcf with this priority */
195	for (back = chain; (tp=*back) != NULL; back = &tp->next) {
196	if (tp->prio >= prio) {
197	if (tp->prio == prio) {
198	if (!nprio \|\| (tp->protocol != protocol && protocol))
199	goto errout;
200	} else
201	tp = NULL;
202	break;
203	}
204	}
205
206	if (tp == NULL) {
207	/* Proto-tcf does not exist, create new one */
208
209	if (tca[TCA_KIND-1] == NULL \|\| !protocol)
210	goto errout;
211
212	err = -ENOENT;
213	if (n->nlmsg_type != RTM_NEWTFILTER \|\| !(n->nlmsg_flags&NLM_F_CREATE))
214	goto errout;
215
216
217	/* Create new proto tcf */
218
219	err = -ENOBUFS;
220	if ((tp = kmalloc(sizeof(*tp), GFP_KERNEL)) == NULL)
221	goto errout;
222	err = -EINVAL;
223	tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]);
224	if (tp_ops == NULL) {
225	#ifdef CONFIG_KMOD
226	struct rtattr *kind = tca[TCA_KIND-1];
227	char name[IFNAMSIZ];
228
229	if (kind != NULL &&
230	rtattr_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
231	rtnl_unlock();
232	request_module("cls_%s", name);
233	rtnl_lock();
234	tp_ops = tcf_proto_lookup_ops(kind);
235	/* We dropped the RTNL semaphore in order to
236	* perform the module load. So, even if we
237	* succeeded in loading the module we have to
238	* replay the request. We indicate this using
239	* -EAGAIN.
240	*/
241	if (tp_ops != NULL) {
242	module_put(tp_ops->owner);
243	err = -EAGAIN;
244	}
245	}
246	#endif
247	kfree(tp);
248	goto errout;
249	}
250	memset(tp, 0, sizeof(*tp));
251	tp->ops = tp_ops;
252	tp->protocol = protocol;
253	tp->prio = nprio ? : tcf_auto_prio(*back);
254	tp->q = q;
255	tp->classify = tp_ops->classify;
256	tp->classid = parent;
257	if ((err = tp_ops->init(tp)) != 0) {
258	module_put(tp_ops->owner);
259	kfree(tp);
260	goto errout;
261	}
262
263	qdisc_lock_tree(dev);
264	tp->next = *back;
265	*back = tp;
266	qdisc_unlock_tree(dev);
267
268	} else if (tca[TCA_KIND-1] && rtattr_strcmp(tca[TCA_KIND-1], tp->ops->kind))
269	goto errout;
270
271	fh = tp->ops->get(tp, t->tcm_handle);
272
273	if (fh == 0) {
274	if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
275	qdisc_lock_tree(dev);
276	*back = tp->next;
277	qdisc_unlock_tree(dev);
278
279	tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
280	tcf_destroy(tp);
281	err = 0;
282	goto errout;
283	}
284
285	err = -ENOENT;
286	if (n->nlmsg_type != RTM_NEWTFILTER \|\| !(n->nlmsg_flags&NLM_F_CREATE))
287	goto errout;
288	} else {
289	switch (n->nlmsg_type) {
290	case RTM_NEWTFILTER:
291	err = -EEXIST;
292	if (n->nlmsg_flags&NLM_F_EXCL)
293	goto errout;
294	break;
295	case RTM_DELTFILTER:
296	err = tp->ops->delete(tp, fh);
297	if (err == 0)
298	tfilter_notify(skb, n, tp, fh, RTM_DELTFILTER);
299	goto errout;
300	case RTM_GETTFILTER:
301	err = tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
302	goto errout;
303	default:
304	err = -EINVAL;
305	goto errout;
306	}
307	}
308
309	err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
310	if (err == 0)
311	tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
312
313	errout:
314	if (cl)
315	cops->put(q, cl);
316	if (err == -EAGAIN)
317	/* Replay the request. */
318	goto replay;
319	return err;
320	}
321
322	static int
323	tcf_fill_node(struct sk_buff skb, struct tcf_proto tp, unsigned long fh,
e431b8c0	324	u32 pid, u32 seq, u16 flags, int event)
1da177e4 LT	325	{
	326	struct tcmsg *tcm;
	327	struct nlmsghdr *nlh;
	328	unsigned char *b = skb->tail;
	329
e431b8c0	330	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*tcm), flags);
1da177e4 LT	331	tcm = NLMSG_DATA(nlh);
1da177e4 LT	332	tcm->tcm_family = AF_UNSPEC;
9ef1d4c7 PM	333	tcm->tcm__pad1 = 0;
9ef1d4c7 PM	334	tcm->tcm__pad1 = 0;
1da177e4 LT	335	tcm->tcm_ifindex = tp->q->dev->ifindex;
	336	tcm->tcm_parent = tp->classid;
	337	tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
	338	RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind);
	339	tcm->tcm_handle = fh;
	340	if (RTM_DELTFILTER != event) {
	341	tcm->tcm_handle = 0;
	342	if (tp->ops->dump && tp->ops->dump(tp, fh, skb, tcm) < 0)
	343	goto rtattr_failure;
	344	}
	345	nlh->nlmsg_len = skb->tail - b;
	346	return skb->len;
	347
	348	nlmsg_failure:
	349	rtattr_failure:
	350	skb_trim(skb, b - skb->data);
	351	return -1;
	352	}
	353
	354	static int tfilter_notify(struct sk_buff oskb, struct nlmsghdr n,
	355	struct tcf_proto *tp, unsigned long fh, int event)
	356	{
	357	struct sk_buff *skb;
	358	u32 pid = oskb ? NETLINK_CB(oskb).pid : 0;
	359
	360	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
	361	if (!skb)
	362	return -ENOBUFS;
	363
	364	if (tcf_fill_node(skb, tp, fh, pid, n->nlmsg_seq, 0, event) <= 0) {
	365	kfree_skb(skb);
	366	return -EINVAL;
	367	}
	368
ac6d439d	369	return rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
1da177e4 LT	370	}
	371
	372	struct tcf_dump_args
	373	{
	374	struct tcf_walker w;
	375	struct sk_buff *skb;
	376	struct netlink_callback *cb;
	377	};
	378
	379	static int tcf_node_dump(struct tcf_proto tp, unsigned long n, struct tcf_walker arg)
	380	{
	381	struct tcf_dump_args a = (void)arg;
	382
	383	return tcf_fill_node(a->skb, tp, n, NETLINK_CB(a->cb->skb).pid,
	384	a->cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER);
	385	}
	386
	387	static int tc_dump_tfilter(struct sk_buff skb, struct netlink_callback cb)
	388	{
	389	int t;
	390	int s_t;
	391	struct net_device *dev;
	392	struct Qdisc *q;
	393	struct tcf_proto tp, *chain;
	394	struct tcmsg tcm = (struct tcmsg)NLMSG_DATA(cb->nlh);
	395	unsigned long cl = 0;
	396	struct Qdisc_class_ops *cops;
	397	struct tcf_dump_args arg;
	398
	399	if (cb->nlh->nlmsg_len < NLMSG_LENGTH(sizeof(*tcm)))
	400	return skb->len;
	401	if ((dev = dev_get_by_index(tcm->tcm_ifindex)) == NULL)
	402	return skb->len;
	403
85670cc1	404	read_lock(&qdisc_tree_lock);
1da177e4 LT	405	if (!tcm->tcm_parent)
	406	q = dev->qdisc_sleeping;
	407	else
	408	q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
	409	if (!q)
	410	goto out;
	411	if ((cops = q->ops->cl_ops) == NULL)
	412	goto errout;
	413	if (TC_H_MIN(tcm->tcm_parent)) {
	414	cl = cops->get(q, tcm->tcm_parent);
	415	if (cl == 0)
	416	goto errout;
	417	}
	418	chain = cops->tcf_chain(q, cl);
	419	if (chain == NULL)
	420	goto errout;
	421
	422	s_t = cb->args[0];
	423
	424	for (tp=*chain, t=0; tp; tp = tp->next, t++) {
	425	if (t < s_t) continue;
	426	if (TC_H_MAJ(tcm->tcm_info) &&
	427	TC_H_MAJ(tcm->tcm_info) != tp->prio)
	428	continue;
	429	if (TC_H_MIN(tcm->tcm_info) &&
	430	TC_H_MIN(tcm->tcm_info) != tp->protocol)
	431	continue;
	432	if (t > s_t)
	433	memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
	434	if (cb->args[1] == 0) {
	435	if (tcf_fill_node(skb, tp, 0, NETLINK_CB(cb->skb).pid,
	436	cb->nlh->nlmsg_seq, NLM_F_MULTI, RTM_NEWTFILTER) <= 0) {
	437	break;
	438	}
	439	cb->args[1] = 1;
	440	}
	441	if (tp->ops->walk == NULL)
	442	continue;
	443	arg.w.fn = tcf_node_dump;
	444	arg.skb = skb;
	445	arg.cb = cb;
	446	arg.w.stop = 0;
	447	arg.w.skip = cb->args[1]-1;
	448	arg.w.count = 0;
	449	tp->ops->walk(tp, &arg.w);
	450	cb->args[1] = arg.w.count+1;
	451	if (arg.w.stop)
	452	break;
	453	}
	454
	455	cb->args[0] = t;
	456
	457	errout:
	458	if (cl)
	459	cops->put(q, cl);
	460	out:
85670cc1	461	read_unlock(&qdisc_tree_lock);
1da177e4 LT	462	dev_put(dev);
	463	return skb->len;
	464	}
	465
	466	void
	467	tcf_exts_destroy(struct tcf_proto tp, struct tcf_exts exts)
	468	{
	469	#ifdef CONFIG_NET_CLS_ACT
	470	if (exts->action) {
	471	tcf_action_destroy(exts->action, TCA_ACT_UNBIND);
	472	exts->action = NULL;
	473	}
	474	#elif defined CONFIG_NET_CLS_POLICE
	475	if (exts->police) {
	476	tcf_police_release(exts->police, TCA_ACT_UNBIND);
	477	exts->police = NULL;
	478	}
	479	#endif
	480	}
	481
	482
	483	int
	484	tcf_exts_validate(struct tcf_proto tp, struct rtattr *tb,
	485	struct rtattr rate_tlv, struct tcf_exts exts,
	486	struct tcf_ext_map *map)
	487	{
	488	memset(exts, 0, sizeof(*exts));
	489
	490	#ifdef CONFIG_NET_CLS_ACT
	491	{
	492	int err;
	493	struct tc_action *act;
	494
	495	if (map->police && tb[map->police-1]) {
	496	act = tcf_action_init_1(tb[map->police-1], rate_tlv, "police",
	497	TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err);
	498	if (act == NULL)
	499	return err;
	500
	501	act->type = TCA_OLD_COMPAT;
	502	exts->action = act;
	503	} else if (map->action && tb[map->action-1]) {
	504	act = tcf_action_init(tb[map->action-1], rate_tlv, NULL,
	505	TCA_ACT_NOREPLACE, TCA_ACT_BIND, &err);
	506	if (act == NULL)
	507	return err;
	508
	509	exts->action = act;
	510	}
	511	}
	512	#elif defined CONFIG_NET_CLS_POLICE
	513	if (map->police && tb[map->police-1]) {
	514	struct tcf_police *p;
	515
	516	p = tcf_police_locate(tb[map->police-1], rate_tlv);
	517	if (p == NULL)
	518	return -EINVAL;
	519
	520	exts->police = p;
	521	} else if (map->action && tb[map->action-1])
	522	return -EOPNOTSUPP;
	523	#else
	524	if ((map->action && tb[map->action-1]) \|\|
	525	(map->police && tb[map->police-1]))
526	return -EOPNOTSUPP;
527	#endif
528
529	return 0;
530	}
531
532	void
533	tcf_exts_change(struct tcf_proto tp, struct tcf_exts dst,
534	struct tcf_exts *src)
535	{
536	#ifdef CONFIG_NET_CLS_ACT
537	if (src->action) {
538	struct tc_action *act;
539	tcf_tree_lock(tp);
540	act = xchg(&dst->action, src->action);
541	tcf_tree_unlock(tp);
542	if (act)
543	tcf_action_destroy(act, TCA_ACT_UNBIND);
544	}
545	#elif defined CONFIG_NET_CLS_POLICE
546	if (src->police) {
547	struct tcf_police *p;
548	tcf_tree_lock(tp);
549	p = xchg(&dst->police, src->police);
550	tcf_tree_unlock(tp);
551	if (p)
552	tcf_police_release(p, TCA_ACT_UNBIND);
553	}
554	#endif
555	}
556
557	int
558	tcf_exts_dump(struct sk_buff skb, struct tcf_exts exts,
559	struct tcf_ext_map *map)
560	{
561	#ifdef CONFIG_NET_CLS_ACT
562	if (map->action && exts->action) {
563	/*
564	* again for backward compatible mode - we want
565	* to work with both old and new modes of entering
566	* tc data even if iproute2 was newer - jhs
567	*/
568	struct rtattr * p_rta = (struct rtattr*) skb->tail;
569
570	if (exts->action->type != TCA_OLD_COMPAT) {
571	RTA_PUT(skb, map->action, 0, NULL);
572	if (tcf_action_dump(skb, exts->action, 0, 0) < 0)
573	goto rtattr_failure;
574	p_rta->rta_len = skb->tail - (u8*)p_rta;
575	} else if (map->police) {
576	RTA_PUT(skb, map->police, 0, NULL);
577	if (tcf_action_dump_old(skb, exts->action, 0, 0) < 0)
578	goto rtattr_failure;
579	p_rta->rta_len = skb->tail - (u8*)p_rta;
580	}
581	}
582	#elif defined CONFIG_NET_CLS_POLICE
583	if (map->police && exts->police) {
584	struct rtattr * p_rta = (struct rtattr*) skb->tail;
585
586	RTA_PUT(skb, map->police, 0, NULL);
587
588	if (tcf_police_dump(skb, exts->police) < 0)
589	goto rtattr_failure;
590
591	p_rta->rta_len = skb->tail - (u8*)p_rta;
592	}
593	#endif
594	return 0;
595	rtattr_failure: __attribute__ ((unused))
596	return -1;
597	}
598
599	int
600	tcf_exts_dump_stats(struct sk_buff skb, struct tcf_exts exts,
601	struct tcf_ext_map *map)
602	{
603	#ifdef CONFIG_NET_CLS_ACT
604	if (exts->action)
605	if (tcf_action_copy_stats(skb, exts->action, 1) < 0)
606	goto rtattr_failure;
607	#elif defined CONFIG_NET_CLS_POLICE
608	if (exts->police)
609	if (tcf_police_dump_stats(skb, exts->police) < 0)
610	goto rtattr_failure;
611	#endif
612	return 0;
613	rtattr_failure: __attribute__ ((unused))
614	return -1;
615	}
616
617	static int __init tc_filter_init(void)
618	{
619	struct rtnetlink_link *link_p = rtnetlink_links[PF_UNSPEC];
620
621	/* Setup rtnetlink links. It is made here to avoid
622	exporting large number of public symbols.
623	*/
624
625	if (link_p) {
626	link_p[RTM_NEWTFILTER-RTM_BASE].doit = tc_ctl_tfilter;
627	link_p[RTM_DELTFILTER-RTM_BASE].doit = tc_ctl_tfilter;
628	link_p[RTM_GETTFILTER-RTM_BASE].doit = tc_ctl_tfilter;
629	link_p[RTM_GETTFILTER-RTM_BASE].dumpit = tc_dump_tfilter;
630	}
631	return 0;
632	}
633
634	subsys_initcall(tc_filter_init);
635
636	EXPORT_SYMBOL(register_tcf_proto_ops);
637	EXPORT_SYMBOL(unregister_tcf_proto_ops);
638	EXPORT_SYMBOL(tcf_exts_validate);
639	EXPORT_SYMBOL(tcf_exts_destroy);
640	EXPORT_SYMBOL(tcf_exts_change);
641	EXPORT_SYMBOL(tcf_exts_dump);
642	EXPORT_SYMBOL(tcf_exts_dump_stats);