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/*
* 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;
}
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