net/sched/cls_api.c - pub/scm/linux/kernel/git/tglx/history - Git at Google

 /*
  * 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, <kuznet@ms2.inr.ac.ru>
  *
  * Changes:
  *
  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
  */

 #include <asm/uaccess.h>
 #include <asm/system.h>
 #include <asm/bitops.h>
 #include <linux/config.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>

 /* 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 rwlock_t cls_mod_lock = RW_LOCK_UNLOCKED;

 /* Find classifier type by string name */

 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)
 				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;

 	write_lock(&cls_mod_lock);
 	for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next) {
 		if (strcmp(ops->kind, t->kind) == 0) {
 			write_unlock(&cls_mod_lock);
 			return -EEXIST;
 		}
 	}

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

 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
 {
 	struct tcf_proto_ops *t, **tp;

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

 	if (!t) {
 		write_unlock(&cls_mod_lock);
 		return -ENOENT;
 	}
 	*tp = t->next;
 	write_unlock(&cls_mod_lock);
 	return 0;
 }

 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 = arg;
 	struct tcmsg *t = NLMSG_DATA(n);
 	u32 protocol = TC_H_MIN(t->tcm_info);
 	u32 prio = TC_H_MAJ(t->tcm_info);
 	u32 nprio = prio;
 	u32 parent = t->tcm_parent;
 	struct net_device *dev;
 	struct Qdisc  *q;
 	struct tcf_proto **back, **chain;
 	struct tcf_proto *tp = NULL;
 	struct tcf_proto_ops *tp_ops;
 	struct Qdisc_class_ops *cops;
 	unsigned long cl = 0;
 	unsigned long fh;
 	int err;

 	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;
 		tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]);
 #ifdef CONFIG_KMOD
 		if (tp_ops==NULL && tca[TCA_KIND-1] != NULL) {
 			struct rtattr *kind = tca[TCA_KIND-1];
 			char module_name[4 + IFNAMSIZ + 1];

 			if (RTA_PAYLOAD(kind) <= IFNAMSIZ) {
 				sprintf(module_name, "cls_%s", (char*)RTA_DATA(kind));
 				request_module (module_name);
 				tp_ops = tcf_proto_lookup_ops(kind);
 			}
 		}
 #endif
 		if (tp_ops == NULL) {
 			err = -EINVAL;
 			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;
 		err = tp_ops->init(tp);
 		if (err) {
 			kfree(tp);
 			goto errout;
 		}
 		write_lock(&qdisc_tree_lock);
 		spin_lock_bh(&dev->queue_lock);
 		tp->next = *back;
 		*back = tp;
 		spin_unlock_bh(&dev->queue_lock);
 		write_unlock(&qdisc_tree_lock);
 	} 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) {
 			write_lock(&qdisc_tree_lock);
 			spin_lock_bh(&dev->queue_lock);
 			*back = tp->next;
 			spin_unlock_bh(&dev->queue_lock);
 			write_unlock(&qdisc_tree_lock);

 			tp->ops->destroy(tp);
 			kfree(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);
 			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);
 	return err;
 }

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

 	nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*tcm));
 	nlh->nlmsg_flags = flags;
 	tcm = NLMSG_DATA(nlh);
 	tcm->tcm_family = AF_UNSPEC;
 	tcm->tcm_ifindex = tp->q->dev->ifindex;
 	tcm->tcm_parent = tp->classid;
 	tcm->tcm_handle = 0;
 	tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
 	RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind);
 	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, RTMGRP_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 == NULL) {
 		read_unlock(&qdisc_tree_lock);
 		dev_put(dev);
 		return skb->len;
 	}
 	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);

 	read_unlock(&qdisc_tree_lock);
 	dev_put(dev);
 	return skb->len;
 }


 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;
 	}
 #define INIT_TC_FILTER(name) { \
           extern struct tcf_proto_ops cls_##name##_ops; \
           register_tcf_proto_ops(&cls_##name##_ops); \
 	}

 #ifdef CONFIG_NET_CLS_U32
 	INIT_TC_FILTER(u32);
 #endif
 #ifdef CONFIG_NET_CLS_ROUTE4
 	INIT_TC_FILTER(route4);
 #endif
 #ifdef CONFIG_NET_CLS_FW
 	INIT_TC_FILTER(fw);
 #endif
 #ifdef CONFIG_NET_CLS_RSVP
 	INIT_TC_FILTER(rsvp);
 #endif
 #ifdef CONFIG_NET_CLS_TCINDEX
 	INIT_TC_FILTER(tcindex);
 #endif
 #ifdef CONFIG_NET_CLS_RSVP6
 	INIT_TC_FILTER(rsvp6);
 #endif
 	return 0;
 }
	/*
	* 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, <kuznet@ms2.inr.ac.ru>
	*
	* Changes:
	*
	* Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
	*/

	#include <asm/uaccess.h>
	#include <asm/system.h>
	#include <asm/bitops.h>
	#include <linux/config.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>

	/* 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 rwlock_t cls_mod_lock = RW_LOCK_UNLOCKED;

	/* Find classifier type by string name */

	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)
	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;

	write_lock(&cls_mod_lock);
	for (tp = &tcf_proto_base; (t=*tp) != NULL; tp = &t->next) {
	if (strcmp(ops->kind, t->kind) == 0) {
	write_unlock(&cls_mod_lock);
	return -EEXIST;
	}
	}

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

	int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
	{
	struct tcf_proto_ops t, *tp;

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

	if (!t) {
	write_unlock(&cls_mod_lock);
	return -ENOENT;
	}
	*tp = t->next;
	write_unlock(&cls_mod_lock);
	return 0;
	}

	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 = arg;
	struct tcmsg *t = NLMSG_DATA(n);
	u32 protocol = TC_H_MIN(t->tcm_info);
	u32 prio = TC_H_MAJ(t->tcm_info);
	u32 nprio = prio;
	u32 parent = t->tcm_parent;
	struct net_device *dev;
	struct Qdisc *q;
	struct tcf_proto back, chain;
	struct tcf_proto *tp = NULL;
	struct tcf_proto_ops *tp_ops;
	struct Qdisc_class_ops *cops;
	unsigned long cl = 0;
	unsigned long fh;
	int err;

	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;
	tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND-1]);
	#ifdef CONFIG_KMOD
	if (tp_ops==NULL && tca[TCA_KIND-1] != NULL) {
	struct rtattr *kind = tca[TCA_KIND-1];
	char module_name[4 + IFNAMSIZ + 1];

	if (RTA_PAYLOAD(kind) <= IFNAMSIZ) {
	sprintf(module_name, "cls_%s", (char*)RTA_DATA(kind));
	request_module (module_name);
	tp_ops = tcf_proto_lookup_ops(kind);
	}
	}
	#endif
	if (tp_ops == NULL) {
	err = -EINVAL;
	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;
	err = tp_ops->init(tp);
	if (err) {
	kfree(tp);
	goto errout;
	}
	write_lock(&qdisc_tree_lock);
	spin_lock_bh(&dev->queue_lock);
	tp->next = *back;
	*back = tp;
	spin_unlock_bh(&dev->queue_lock);
	write_unlock(&qdisc_tree_lock);
	} 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) {
	write_lock(&qdisc_tree_lock);
	spin_lock_bh(&dev->queue_lock);
	*back = tp->next;
	spin_unlock_bh(&dev->queue_lock);
	write_unlock(&qdisc_tree_lock);

	tp->ops->destroy(tp);
	kfree(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);
	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);
	return err;
	}

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

	nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*tcm));
	nlh->nlmsg_flags = flags;
	tcm = NLMSG_DATA(nlh);
	tcm->tcm_family = AF_UNSPEC;
	tcm->tcm_ifindex = tp->q->dev->ifindex;
	tcm->tcm_parent = tp->classid;
	tcm->tcm_handle = 0;
	tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
	RTA_PUT(skb, TCA_KIND, IFNAMSIZ, tp->ops->kind);
	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, RTMGRP_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 == NULL) {
	read_unlock(&qdisc_tree_lock);
	dev_put(dev);
	return skb->len;
	}
	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);

	read_unlock(&qdisc_tree_lock);
	dev_put(dev);
	return skb->len;
	}


	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;
	}
	#define INIT_TC_FILTER(name) { \
	extern struct tcf_proto_ops cls_##name##_ops; \
	register_tcf_proto_ops(&cls_##name##_ops); \
	}

	#ifdef CONFIG_NET_CLS_U32
	INIT_TC_FILTER(u32);
	#endif
	#ifdef CONFIG_NET_CLS_ROUTE4
	INIT_TC_FILTER(route4);
	#endif
	#ifdef CONFIG_NET_CLS_FW
	INIT_TC_FILTER(fw);
	#endif
	#ifdef CONFIG_NET_CLS_RSVP
	INIT_TC_FILTER(rsvp);
	#endif
	#ifdef CONFIG_NET_CLS_TCINDEX
	INIT_TC_FILTER(tcindex);
	#endif
	#ifdef CONFIG_NET_CLS_RSVP6
	INIT_TC_FILTER(rsvp6);
	#endif
	return 0;
	}