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/*
* net/sched/cls_u32.c Ugly (or Universal) 32bit key Packet Classifier.
*
* 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>
*
* The filters are packed to hash tables of key nodes
* with a set of 32bit key/mask pairs at every node.
* Nodes reference next level hash tables etc.
*
* This scheme is the best universal classifier I managed to
* invent; it is not super-fast, but it is not slow (provided you
* program it correctly), and general enough. And its relative
* speed grows as the number of rules becomes larger.
*
* It seems that it represents the best middle point between
* speed and manageability both by human and by machine.
*
* It is especially useful for link sharing combined with QoS;
* pure RSVP doesn't need such a general approach and can use
* much simpler (and faster) schemes, sort of cls_rsvp.c.
*/
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <linux/config.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/if_ether.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/notifier.h>
#include <linux/rtnetlink.h>
#include <net/ip.h>
#include <net/route.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
struct tc_u_knode
{
struct tc_u_knode *next;
u32 handle;
struct tc_u_hnode *ht_up;
#ifdef CONFIG_NET_CLS_POLICE
struct tcf_police *police;
#endif
struct tcf_result res;
struct tc_u_hnode *ht_down;
struct tc_u32_sel sel;
};
struct tc_u_hnode
{
struct tc_u_hnode *next;
u32 handle;
struct tc_u_common *tp_c;
int refcnt;
unsigned divisor;
u32 hgenerator;
struct tc_u_knode *ht[1];
};
struct tc_u_common
{
struct tc_u_common *next;
struct tc_u_hnode *hlist;
struct Qdisc *q;
int refcnt;
u32 hgenerator;
};
static struct tc_u_common *u32_list;
static __inline__ unsigned u32_hash_fold(u32 key, struct tc_u32_sel *sel)
{
unsigned h = key & sel->hmask;
h ^= h>>16;
h ^= h>>8;
return h;
}
static int u32_classify(struct sk_buff *skb, struct tcf_proto *tp, struct tcf_result *res)
{
struct {
struct tc_u_knode *knode;
u8 *ptr;
} stack[TC_U32_MAXDEPTH];
struct tc_u_hnode *ht = (struct tc_u_hnode*)tp->root;
u8 *ptr = skb->nh.raw;
struct tc_u_knode *n;
int sdepth = 0;
int off2 = 0;
int sel = 0;
int i;
#if !defined(__i386__) && !defined(__mc68000__)
if ((unsigned long)ptr & 3)
return -1;
#endif
next_ht:
n = ht->ht[sel];
next_knode:
if (n) {
struct tc_u32_key *key = n->sel.keys;
for (i = n->sel.nkeys; i>0; i--, key++) {
if ((*(u32*)(ptr+key->off+(off2&key->offmask))^key->val)&key->mask) {
n = n->next;
goto next_knode;
}
}
if (n->ht_down == NULL) {
check_terminal:
if (n->sel.flags&TC_U32_TERMINAL) {
*res = n->res;
#ifdef CONFIG_NET_CLS_POLICE
if (n->police) {
int pol_res = tcf_police(skb, n->police);
if (pol_res >= 0)
return pol_res;
} else
#endif
return 0;
}
n = n->next;
goto next_knode;
}
/* PUSH */
if (sdepth >= TC_U32_MAXDEPTH)
goto deadloop;
stack[sdepth].knode = n;
stack[sdepth].ptr = ptr;
sdepth++;
ht = n->ht_down;
sel = 0;
if (ht->divisor)
sel = ht->divisor&u32_hash_fold(*(u32*)(ptr+n->sel.hoff), &n->sel);
if (!(n->sel.flags&(TC_U32_VAROFFSET|TC_U32_OFFSET|TC_U32_EAT)))
goto next_ht;
if (n->sel.flags&(TC_U32_OFFSET|TC_U32_VAROFFSET)) {
off2 = n->sel.off + 3;
if (n->sel.flags&TC_U32_VAROFFSET)
off2 += ntohs(n->sel.offmask & *(u16*)(ptr+n->sel.offoff)) >>n->sel.offshift;
off2 &= ~3;
}
if (n->sel.flags&TC_U32_EAT) {
ptr += off2;
off2 = 0;
}
if (ptr < skb->tail)
goto next_ht;
}
/* POP */
if (sdepth--) {
n = stack[sdepth].knode;
ht = n->ht_up;
ptr = stack[sdepth].ptr;
goto check_terminal;
}
return -1;
deadloop:
if (net_ratelimit())
printk("cls_u32: dead loop\n");
return -1;
}
static __inline__ struct tc_u_hnode *
u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
{
struct tc_u_hnode *ht;
for (ht = tp_c->hlist; ht; ht = ht->next)
if (ht->handle == handle)
break;
return ht;
}
static __inline__ struct tc_u_knode *
u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
{
unsigned sel;
struct tc_u_knode *n;
sel = TC_U32_HASH(handle);
if (sel > ht->divisor)
return 0;
for (n = ht->ht[sel]; n; n = n->next)
if (n->handle == handle)
return n;
return NULL;
}
static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
{
struct tc_u_hnode *ht;
struct tc_u_common *tp_c = tp->data;
if (TC_U32_HTID(handle) == TC_U32_ROOT)
ht = tp->root;
else
ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
if (!ht)
return 0;
if (TC_U32_KEY(handle) == 0)
return (unsigned long)ht;
return (unsigned long)u32_lookup_key(ht, handle);
}
static void u32_put(struct tcf_proto *tp, unsigned long f)
{
}
static u32 gen_new_htid(struct tc_u_common *tp_c)
{
int i = 0x800;
do {
if (++tp_c->hgenerator == 0x7FF)
tp_c->hgenerator = 1;
} while (--i>0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
}
static int u32_init(struct tcf_proto *tp)
{
struct tc_u_hnode *root_ht;
struct tc_u_common *tp_c;
MOD_INC_USE_COUNT;
for (tp_c = u32_list; tp_c; tp_c = tp_c->next)
if (tp_c->q == tp->q)
break;
root_ht = kmalloc(sizeof(*root_ht), GFP_KERNEL);
if (root_ht == NULL) {
MOD_DEC_USE_COUNT;
return -ENOBUFS;
}
memset(root_ht, 0, sizeof(*root_ht));
root_ht->divisor = 0;
root_ht->refcnt++;
root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
if (tp_c == NULL) {
tp_c = kmalloc(sizeof(*tp_c), GFP_KERNEL);
if (tp_c == NULL) {
kfree(root_ht);
MOD_DEC_USE_COUNT;
return -ENOBUFS;
}
memset(tp_c, 0, sizeof(*tp_c));
tp_c->q = tp->q;
tp_c->next = u32_list;
u32_list = tp_c;
}
tp_c->refcnt++;
root_ht->next = tp_c->hlist;
tp_c->hlist = root_ht;
root_ht->tp_c = tp_c;
tp->root = root_ht;
tp->data = tp_c;
return 0;
}
static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n)
{
unsigned long cl;
if ((cl = __cls_set_class(&n->res.class, 0)) != 0)
tp->q->ops->cl_ops->unbind_tcf(tp->q, cl);
#ifdef CONFIG_NET_CLS_POLICE
tcf_police_release(n->police);
#endif
if (n->ht_down)
n->ht_down->refcnt--;
kfree(n);
return 0;
}
static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode* key)
{
struct tc_u_knode **kp;
struct tc_u_hnode *ht = key->ht_up;
if (ht) {
for (kp = &ht->ht[TC_U32_HASH(key->handle)]; *kp; kp = &(*kp)->next) {
if (*kp == key) {
tcf_tree_lock(tp);
*kp = key->next;
tcf_tree_unlock(tp);
u32_destroy_key(tp, key);
return 0;
}
}
}
BUG_TRAP(0);
return 0;
}
static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
{
struct tc_u_knode *n;
unsigned h;
for (h=0; h<=ht->divisor; h++) {
while ((n = ht->ht[h]) != NULL) {
ht->ht[h] = n->next;
u32_destroy_key(tp, n);
}
}
}
static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
{
struct tc_u_common *tp_c = tp->data;
struct tc_u_hnode **hn;
BUG_TRAP(!ht->refcnt);
u32_clear_hnode(tp, ht);
for (hn = &tp_c->hlist; *hn; hn = &(*hn)->next) {
if (*hn == ht) {
*hn = ht->next;
kfree(ht);
return 0;
}
}
BUG_TRAP(0);
return -ENOENT;
}
static void u32_destroy(struct tcf_proto *tp)
{
struct tc_u_common *tp_c = tp->data;
struct tc_u_hnode *root_ht = xchg(&tp->root, NULL);
BUG_TRAP(root_ht != NULL);
if (root_ht && --root_ht->refcnt == 0)
u32_destroy_hnode(tp, root_ht);
if (--tp_c->refcnt == 0) {
struct tc_u_hnode *ht;
struct tc_u_common **tp_cp;
for (tp_cp = &u32_list; *tp_cp; tp_cp = &(*tp_cp)->next) {
if (*tp_cp == tp_c) {
*tp_cp = tp_c->next;
break;
}
}
for (ht=tp_c->hlist; ht; ht = ht->next)
u32_clear_hnode(tp, ht);
while ((ht = tp_c->hlist) != NULL) {
tp_c->hlist = ht->next;
BUG_TRAP(ht->refcnt == 0);
kfree(ht);
};
kfree(tp_c);
}
MOD_DEC_USE_COUNT;
tp->data = NULL;
}
static int u32_delete(struct tcf_proto *tp, unsigned long arg)
{
struct tc_u_hnode *ht = (struct tc_u_hnode*)arg;
if (ht == NULL)
return 0;
if (TC_U32_KEY(ht->handle))
return u32_delete_key(tp, (struct tc_u_knode*)ht);
if (tp->root == ht)
return -EINVAL;
if (--ht->refcnt == 0)
u32_destroy_hnode(tp, ht);
return 0;
}
static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
{
struct tc_u_knode *n;
unsigned i = 0x7FF;
for (n=ht->ht[TC_U32_HASH(handle)]; n; n = n->next)
if (i < TC_U32_NODE(n->handle))
i = TC_U32_NODE(n->handle);
i++;
return handle|(i>0xFFF ? 0xFFF : i);
}
static int u32_set_parms(struct Qdisc *q, unsigned long base,
struct tc_u_hnode *ht,
struct tc_u_knode *n, struct rtattr **tb,
struct rtattr *est)
{
if (tb[TCA_U32_LINK-1]) {
u32 handle = *(u32*)RTA_DATA(tb[TCA_U32_LINK-1]);
struct tc_u_hnode *ht_down = NULL;
if (TC_U32_KEY(handle))
return -EINVAL;
if (handle) {
ht_down = u32_lookup_ht(ht->tp_c, handle);
if (ht_down == NULL)
return -EINVAL;
ht_down->refcnt++;
}
sch_tree_lock(q);
ht_down = xchg(&n->ht_down, ht_down);
sch_tree_unlock(q);
if (ht_down)
ht_down->refcnt--;
}
if (tb[TCA_U32_CLASSID-1]) {
unsigned long cl;
n->res.classid = *(u32*)RTA_DATA(tb[TCA_U32_CLASSID-1]);
sch_tree_lock(q);
cl = __cls_set_class(&n->res.class, q->ops->cl_ops->bind_tcf(q, base, n->res.classid));
sch_tree_unlock(q);
if (cl)
q->ops->cl_ops->unbind_tcf(q, cl);
}
#ifdef CONFIG_NET_CLS_POLICE
if (tb[TCA_U32_POLICE-1]) {
struct tcf_police *police = tcf_police_locate(tb[TCA_U32_POLICE-1], est);
sch_tree_lock(q);
police = xchg(&n->police, police);
sch_tree_unlock(q);
tcf_police_release(police);
}
#endif
return 0;
}
static int u32_change(struct tcf_proto *tp, unsigned long base, u32 handle,
struct rtattr **tca,
unsigned long *arg)
{
struct tc_u_common *tp_c = tp->data;
struct tc_u_hnode *ht;
struct tc_u_knode *n;
struct tc_u32_sel *s;
struct rtattr *opt = tca[TCA_OPTIONS-1];
struct rtattr *tb[TCA_U32_MAX];
u32 htid;
int err;
if (opt == NULL)
return handle ? -EINVAL : 0;
if (rtattr_parse(tb, TCA_U32_MAX, RTA_DATA(opt), RTA_PAYLOAD(opt)) < 0)
return -EINVAL;
if ((n = (struct tc_u_knode*)*arg) != NULL) {
if (TC_U32_KEY(n->handle) == 0)
return -EINVAL;
return u32_set_parms(tp->q, base, n->ht_up, n, tb, tca[TCA_RATE-1]);
}
if (tb[TCA_U32_DIVISOR-1]) {
unsigned divisor = *(unsigned*)RTA_DATA(tb[TCA_U32_DIVISOR-1]);
if (--divisor > 0x100)
return -EINVAL;
if (TC_U32_KEY(handle))
return -EINVAL;
if (handle == 0) {
handle = gen_new_htid(tp->data);
if (handle == 0)
return -ENOMEM;
}
ht = kmalloc(sizeof(*ht) + divisor*sizeof(void*), GFP_KERNEL);
if (ht == NULL)
return -ENOBUFS;
memset(ht, 0, sizeof(*ht) + divisor*sizeof(void*));
ht->tp_c = tp_c;
ht->refcnt = 0;
ht->divisor = divisor;
ht->handle = handle;
ht->next = tp_c->hlist;
tp_c->hlist = ht;
*arg = (unsigned long)ht;
return 0;
}
if (tb[TCA_U32_HASH-1]) {
htid = *(unsigned*)RTA_DATA(tb[TCA_U32_HASH-1]);
if (TC_U32_HTID(htid) == TC_U32_ROOT) {
ht = tp->root;
htid = ht->handle;
} else {
ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
if (ht == NULL)
return -EINVAL;
}
} else {
ht = tp->root;
htid = ht->handle;
}
if (ht->divisor < TC_U32_HASH(htid))
return -EINVAL;
if (handle) {
if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
return -EINVAL;
handle = htid | TC_U32_NODE(handle);
} else
handle = gen_new_kid(ht, htid);
if (tb[TCA_U32_SEL-1] == 0 ||
RTA_PAYLOAD(tb[TCA_U32_SEL-1]) < sizeof(struct tc_u32_sel))
return -EINVAL;
s = RTA_DATA(tb[TCA_U32_SEL-1]);
n = kmalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
if (n == NULL)
return -ENOBUFS;
memset(n, 0, sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key));
memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
n->ht_up = ht;
n->handle = handle;
err = u32_set_parms(tp->q, base, ht, n, tb, tca[TCA_RATE-1]);
if (err == 0) {
struct tc_u_knode **ins;
for (ins = &ht->ht[TC_U32_HASH(handle)]; *ins; ins = &(*ins)->next)
if (TC_U32_NODE(handle) < TC_U32_NODE((*ins)->handle))
break;
n->next = *ins;
wmb();
*ins = n;
*arg = (unsigned long)n;
return 0;
}
kfree(n);
return err;
}
static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
struct tc_u_common *tp_c = tp->data;
struct tc_u_hnode *ht;
struct tc_u_knode *n;
unsigned h;
if (arg->stop)
return;
for (ht = tp_c->hlist; ht; ht = ht->next) {
if (arg->count >= arg->skip) {
if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
arg->stop = 1;
return;
}
}
arg->count++;
for (h = 0; h <= ht->divisor; h++) {
for (n = ht->ht[h]; n; n = n->next) {
if (arg->count < arg->skip) {
arg->count++;
continue;
}
if (arg->fn(tp, (unsigned long)n, arg) < 0) {
arg->stop = 1;
return;
}
arg->count++;
}
}
}
}
static int u32_dump(struct tcf_proto *tp, unsigned long fh,
struct sk_buff *skb, struct tcmsg *t)
{
struct tc_u_knode *n = (struct tc_u_knode*)fh;
unsigned char *b = skb->tail;
struct rtattr *rta;
if (n == NULL)
return skb->len;
t->tcm_handle = n->handle;
rta = (struct rtattr*)b;
RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
if (TC_U32_KEY(n->handle) == 0) {
struct tc_u_hnode *ht = (struct tc_u_hnode*)fh;
u32 divisor = ht->divisor+1;
RTA_PUT(skb, TCA_U32_DIVISOR, 4, &divisor);
} else {
RTA_PUT(skb, TCA_U32_SEL,
sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
&n->sel);
if (n->ht_up) {
u32 htid = n->handle & 0xFFFFF000;
RTA_PUT(skb, TCA_U32_HASH, 4, &htid);
}
if (n->res.classid)
RTA_PUT(skb, TCA_U32_CLASSID, 4, &n->res.classid);
if (n->ht_down)
RTA_PUT(skb, TCA_U32_LINK, 4, &n->ht_down->handle);
#ifdef CONFIG_NET_CLS_POLICE
if (n->police) {
struct rtattr * p_rta = (struct rtattr*)skb->tail;
RTA_PUT(skb, TCA_U32_POLICE, 0, NULL);
if (tcf_police_dump(skb, n->police) < 0)
goto rtattr_failure;
p_rta->rta_len = skb->tail - (u8*)p_rta;
}
#endif
}
rta->rta_len = skb->tail - b;
#ifdef CONFIG_NET_CLS_POLICE
if (TC_U32_KEY(n->handle) && n->police) {
if (qdisc_copy_stats(skb, &n->police->stats))
goto rtattr_failure;
}
#endif
return skb->len;
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
struct tcf_proto_ops cls_u32_ops = {
NULL,
"u32",
u32_classify,
u32_init,
u32_destroy,
u32_get,
u32_put,
u32_change,
u32_delete,
u32_walk,
u32_dump
};
#ifdef MODULE
int init_module(void)
{
return register_tcf_proto_ops(&cls_u32_ops);
}
void cleanup_module(void)
{
unregister_tcf_proto_ops(&cls_u32_ops);
}
#endif
MODULE_LICENSE("GPL");
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