--- /dev/null
+/*-
+ * Copyright (c) 1998-2002,2010 Luigi Rizzo, Universita` di Pisa
+ * All rights reserved
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Binary heap and hash tables, used in dummynet
+ *
+ * $Id: dn_heap.c 5646 2010-03-08 12:48:30Z luigi $
+ */
+
+#include <sys/cdefs.h>
+#include <sys/param.h>
+#ifdef _KERNEL
+__FBSDID("$FreeBSD: user/luigi/ipfw3-head/sys/netinet/ipfw/dn_heap.c 203279 2010-01-31 12:20:29Z luigi $");
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/kernel.h>
+#include <netinet/ipfw/dn_heap.h>
+#ifndef log
+#define log(x, arg...)
+#endif
+
+#else /* !_KERNEL */
+
+#include <stdio.h>
+#include <dn_test.h>
+#include <strings.h>
+#include <stdlib.h>
+
+#include "dn_heap.h"
+#define log(x, arg...) fprintf(stderr, ## arg)
+#define panic(x...) fprintf(stderr, ## x), exit(1)
+#define MALLOC_DEFINE(a, b, c)
+static void *my_malloc(int s) { return malloc(s); }
+static void my_free(void *p) { free(p); }
+#define malloc(s, t, w) my_malloc(s)
+#define free(p, t) my_free(p)
+#endif /* !_KERNEL */
+
+MALLOC_DEFINE(M_DN_HEAP, "dummynet", "dummynet heap");
+
+/*
+ * Heap management functions.
+ *
+ * In the heap, first node is element 0. Children of i are 2i+1 and 2i+2.
+ * Some macros help finding parent/children so we can optimize them.
+ *
+ * heap_init() is called to expand the heap when needed.
+ * Increment size in blocks of 16 entries.
+ * Returns 1 on error, 0 on success
+ */
+#define HEAP_FATHER(x) ( ( (x) - 1 ) / 2 )
+#define HEAP_LEFT(x) ( (x)+(x) + 1 )
+#define HEAP_SWAP(a, b, buffer) { buffer = a ; a = b ; b = buffer ; }
+#define HEAP_INCREMENT 15
+
+static int
+heap_resize(struct dn_heap *h, unsigned int new_size)
+{
+ struct dn_heap_entry *p;
+
+ if (h->size >= new_size ) /* have enough room */
+ return 0;
+#if 1 /* round to the next power of 2 */
+ new_size |= new_size >> 1;
+ new_size |= new_size >> 2;
+ new_size |= new_size >> 4;
+ new_size |= new_size >> 8;
+ new_size |= new_size >> 16;
+#else
+ new_size = (new_size + HEAP_INCREMENT ) & ~HEAP_INCREMENT;
+#endif
+ p = malloc(new_size * sizeof(*p), M_DN_HEAP, M_NOWAIT);
+ if (p == NULL) {
+ printf("--- %s, resize %d failed\n", __func__, new_size );
+ return 1; /* error */
+ }
+ if (h->size > 0) {
+ bcopy(h->p, p, h->size * sizeof(*p) );
+ free(h->p, M_DN_HEAP);
+ }
+ h->p = p;
+ h->size = new_size;
+ return 0;
+}
+
+int
+heap_init(struct dn_heap *h, int size, int ofs)
+{
+ if (heap_resize(h, size))
+ return 1;
+ h->elements = 0;
+ h->ofs = ofs;
+ return 0;
+}
+
+/*
+ * Insert element in heap. Normally, p != NULL, we insert p in
+ * a new position and bubble up. If p == NULL, then the element is
+ * already in place, and key is the position where to start the
+ * bubble-up.
+ * Returns 1 on failure (cannot allocate new heap entry)
+ *
+ * If ofs > 0 the position (index, int) of the element in the heap is
+ * also stored in the element itself at the given offset in bytes.
+ */
+#define SET_OFFSET(h, i) do { \
+ if (h->ofs > 0) \
+ *((int32_t *)((char *)(h->p[i].object) + h->ofs)) = i; \
+ } while (0)
+/*
+ * RESET_OFFSET is used for sanity checks. It sets ofs
+ * to an invalid value.
+ */
+#define RESET_OFFSET(h, i) do { \
+ if (h->ofs > 0) \
+ *((int32_t *)((char *)(h->p[i].object) + h->ofs)) = -16; \
+ } while (0)
+
+int
+heap_insert(struct dn_heap *h, uint64_t key1, void *p)
+{
+ int son = h->elements;
+
+ //log("%s key %llu p %p\n", __FUNCTION__, key1, p);
+ if (p == NULL) { /* data already there, set starting point */
+ son = key1;
+ } else { /* insert new element at the end, possibly resize */
+ son = h->elements;
+ if (son == h->size) /* need resize... */
+ // XXX expand by 16 or so
+ if (heap_resize(h, h->elements+16) )
+ return 1; /* failure... */
+ h->p[son].object = p;
+ h->p[son].key = key1;
+ h->elements++;
+ }
+ /* make sure that son >= father along the path */
+ while (son > 0) {
+ int father = HEAP_FATHER(son);
+ struct dn_heap_entry tmp;
+
+ if (DN_KEY_LT( h->p[father].key, h->p[son].key ) )
+ break; /* found right position */
+ /* son smaller than father, swap and repeat */
+ HEAP_SWAP(h->p[son], h->p[father], tmp);
+ SET_OFFSET(h, son);
+ son = father;
+ }
+ SET_OFFSET(h, son);
+ return 0;
+}
+
+/*
+ * remove top element from heap, or obj if obj != NULL
+ */
+void
+heap_extract(struct dn_heap *h, void *obj)
+{
+ int child, father, max = h->elements - 1;
+
+ if (max < 0) {
+ printf("--- %s: empty heap 0x%p\n", __FUNCTION__, h);
+ return;
+ }
+ if (obj == NULL)
+ father = 0; /* default: move up smallest child */
+ else { /* extract specific element, index is at offset */
+ if (h->ofs <= 0)
+ panic("%s: extract from middle not set on %p\n",
+ __FUNCTION__, h);
+ father = *((int *)((char *)obj + h->ofs));
+ if (father < 0 || father >= h->elements) {
+ panic("%s: father %d out of bound 0..%d\n",
+ __FUNCTION__, father, h->elements);
+ }
+ }
+ /*
+ * below, father is the index of the empty element, which
+ * we replace at each step with the smallest child until we
+ * reach the bottom level.
+ */
+ // XXX why removing RESET_OFFSET increases runtime by 10% ?
+ RESET_OFFSET(h, father);
+ while ( (child = HEAP_LEFT(father)) <= max ) {
+ if (child != max &&
+ DN_KEY_LT(h->p[child+1].key, h->p[child].key) )
+ child++; /* take right child, otherwise left */
+ h->p[father] = h->p[child];
+ SET_OFFSET(h, father);
+ father = child;
+ }
+ h->elements--;
+ if (father != max) {
+ /*
+ * Fill hole with last entry and bubble up,
+ * reusing the insert code
+ */
+ h->p[father] = h->p[max];
+ heap_insert(h, father, NULL);
+ }
+}
+
+#if 0
+/*
+ * change object position and update references
+ * XXX this one is never used!
+ */
+static void
+heap_move(struct dn_heap *h, uint64_t new_key, void *object)
+{
+ int temp, i, max = h->elements-1;
+ struct dn_heap_entry *p, buf;
+
+ if (h->ofs <= 0)
+ panic("cannot move items on this heap");
+ p = h->p; /* shortcut */
+
+ i = *((int *)((char *)object + h->ofs));
+ if (DN_KEY_LT(new_key, p[i].key) ) { /* must move up */
+ p[i].key = new_key;
+ for (; i>0 &&
+ DN_KEY_LT(new_key, p[(temp = HEAP_FATHER(i))].key);
+ i = temp ) { /* bubble up */
+ HEAP_SWAP(p[i], p[temp], buf);
+ SET_OFFSET(h, i);
+ }
+ } else { /* must move down */
+ p[i].key = new_key;
+ while ( (temp = HEAP_LEFT(i)) <= max ) {
+ /* found left child */
+ if (temp != max &&
+ DN_KEY_LT(p[temp+1].key, p[temp].key))
+ temp++; /* select child with min key */
+ if (DN_KEY_LT(>p[temp].key, new_key)) {
+ /* go down */
+ HEAP_SWAP(p[i], p[temp], buf);
+ SET_OFFSET(h, i);
+ } else
+ break;
+ i = temp;
+ }
+ }
+ SET_OFFSET(h, i);
+}
+#endif /* heap_move, unused */
+
+/*
+ * heapify() will reorganize data inside an array to maintain the
+ * heap property. It is needed when we delete a bunch of entries.
+ */
+static void
+heapify(struct dn_heap *h)
+{
+ int i;
+
+ for (i = 0; i < h->elements; i++ )
+ heap_insert(h, i , NULL);
+}
+
+int
+heap_scan(struct dn_heap *h, int (*fn)(void *, uintptr_t),
+ uintptr_t arg)
+{
+ int i, ret, found;
+
+ for (i = found = 0 ; i < h->elements ;) {
+ ret = fn(h->p[i].object, arg);
+ if (ret & HEAP_SCAN_DEL) {
+ h->elements-- ;
+ h->p[i] = h->p[h->elements] ;
+ found++ ;
+ } else
+ i++ ;
+ if (ret & HEAP_SCAN_END)
+ break;
+ }
+ if (found)
+ heapify(h);
+ return found;
+}
+
+/*
+ * cleanup the heap and free data structure
+ */
+void
+heap_free(struct dn_heap *h)
+{
+ if (h->size >0 )
+ free(h->p, M_DN_HEAP);
+ bzero(h, sizeof(*h) );
+}
+
+/*
+ * hash table support.
+ */
+
+struct dn_ht {
+ int buckets; /* how many buckets, really buckets - 1*/
+ int entries; /* how many entries */
+ int ofs; /* offset of link field */
+ uint32_t (*hash)(uintptr_t, int, void *arg);
+ int (*match)(void *_el, uintptr_t key, int, void *);
+ void *(*newh)(uintptr_t, int, void *);
+ void **ht; /* bucket heads */
+};
+/*
+ * Initialize, allocating bucket pointers inline.
+ * Recycle previous record if possible.
+ * If the 'newh' function is not supplied, we assume that the
+ * key passed to ht_find is the same object to be stored in.
+ */
+struct dn_ht *
+dn_ht_init(struct dn_ht *ht, int buckets, int ofs,
+ uint32_t (*h)(uintptr_t, int, void *),
+ int (*match)(void *, uintptr_t, int, void *),
+ void *(*newh)(uintptr_t, int, void *))
+{
+ int l;
+
+ /*
+ * Notes about rounding bucket size to a power of two.
+ * Given the original bucket size, we compute the nearest lower and
+ * higher power of two, minus 1 (respectively b_min and b_max) because
+ * this value will be used to do an AND with the index returned
+ * by hash function.
+ * To choice between these two values, the original bucket size is
+ * compared with b_min. If the original size is greater than 4/3 b_min,
+ * we round the bucket size to b_max, else to b_min.
+ * This ratio try to round to the nearest power of two, advantaging
+ * the greater size if the different between two power is relatively
+ * big.
+ * Rounding the bucket size to a power of two avoid the use of
+ * module when calculating the correct bucket.
+ * The ht->buckets variable store the bucket size - 1 to simply
+ * do an AND between the index returned by hash function and ht->bucket
+ * instead of a module.
+ */
+ int b_min; /* min buckets */
+ int b_max; /* max buckets */
+ int b_ori; /* original buckets */
+
+ if (h == NULL || match == NULL) {
+ printf("--- missing hash or match function");
+ return NULL;
+ }
+ if (buckets < 1 || buckets > 65536)
+ return NULL;
+
+ b_ori = buckets;
+ /* calculate next power of 2, - 1*/
+ buckets |= buckets >> 1;
+ buckets |= buckets >> 2;
+ buckets |= buckets >> 4;
+ buckets |= buckets >> 8;
+ buckets |= buckets >> 16;
+
+ b_max = buckets; /* Next power */
+ b_min = buckets >> 1; /* Previous power */
+
+ /* Calculate the 'nearest' bucket size */
+ if (b_min * 4000 / 3000 < b_ori)
+ buckets = b_max;
+ else
+ buckets = b_min;
+
+ if (ht) { /* see if we can reuse */
+ if (buckets <= ht->buckets) {
+ ht->buckets = buckets;
+ } else {
+ /* free pointers if not allocated inline */
+ if (ht->ht != (void *)(ht + 1))
+ free(ht->ht, M_DN_HEAP);
+ free(ht, M_DN_HEAP);
+ ht = NULL;
+ }
+ }
+ if (ht == NULL) {
+ /* Allocate buckets + 1 entries because buckets is use to
+ * do the AND with the index returned by hash function
+ */
+ l = sizeof(*ht) + (buckets + 1) * sizeof(void **);
+ ht = malloc(l, M_DN_HEAP, M_NOWAIT | M_ZERO);
+ }
+ if (ht) {
+ ht->ht = (void **)(ht + 1);
+ ht->buckets = buckets;
+ ht->ofs = ofs;
+ ht->hash = h;
+ ht->match = match;
+ ht->newh = newh;
+ }
+ return ht;
+}
+
+/* dummy callback for dn_ht_free to unlink all */
+static int
+do_del(void *obj, void *arg)
+{
+ return DNHT_SCAN_DEL;
+}
+
+void
+dn_ht_free(struct dn_ht *ht, int flags)
+{
+ if (ht == NULL)
+ return;
+ if (flags & DNHT_REMOVE) {
+ (void)dn_ht_scan(ht, do_del, NULL);
+ } else {
+ if (ht->ht && ht->ht != (void *)(ht + 1))
+ free(ht->ht, M_DN_HEAP);
+ free(ht, M_DN_HEAP);
+ }
+}
+
+int
+dn_ht_entries(struct dn_ht *ht)
+{
+ return ht ? ht->entries : 0;
+}
+
+/* lookup and optionally create or delete element */
+void *
+dn_ht_find(struct dn_ht *ht, uintptr_t key, int flags, void *arg)
+{
+ int i;
+ void **pp, *p;
+
+ if (ht == NULL) /* easy on an empty hash */
+ return NULL;
+ i = (ht->buckets == 1) ? 0 :
+ (ht->hash(key, flags, arg) & ht->buckets);
+
+ for (pp = &ht->ht[i]; (p = *pp); pp = (void **)((char *)p + ht->ofs)) {
+ if (flags & DNHT_MATCH_PTR) {
+ if (key == (uintptr_t)p)
+ break;
+ } else if (ht->match(p, key, flags, arg)) /* found match */
+ break;
+ }
+ if (p) {
+ if (flags & DNHT_REMOVE) {
+ /* link in the next element */
+ *pp = *(void **)((char *)p + ht->ofs);
+ *(void **)((char *)p + ht->ofs) = NULL;
+ ht->entries--;
+ }
+ } else if (flags & DNHT_INSERT) {
+ // printf("%s before calling new, bucket %d ofs %d\n",
+ // __FUNCTION__, i, ht->ofs);
+ p = ht->newh ? ht->newh(key, flags, arg) : (void *)key;
+ // printf("%s newh returns %p\n", __FUNCTION__, p);
+ if (p) {
+ ht->entries++;
+ *(void **)((char *)p + ht->ofs) = ht->ht[i];
+ ht->ht[i] = p;
+ }
+ }
+ return p;
+}
+
+/*
+ * do a scan with the option to delete the object. Extract next before
+ * running the callback because the element may be destroyed there.
+ */
+int
+dn_ht_scan(struct dn_ht *ht, int (*fn)(void *, void *), void *arg)
+{
+ int i, ret, found = 0;
+ void **curp, *cur, *next;
+
+ if (ht == NULL || fn == NULL)
+ return 0;
+ for (i = 0; i <= ht->buckets; i++) {
+ curp = &ht->ht[i];
+ while ( (cur = *curp) != NULL) {
+ next = *(void **)((char *)cur + ht->ofs);
+ ret = fn(cur, arg);
+ if (ret & DNHT_SCAN_DEL) {
+ found++;
+ ht->entries--;
+ *curp = next;
+ } else {
+ curp = (void **)((char *)cur + ht->ofs);
+ }
+ if (ret & DNHT_SCAN_END)
+ return found;
+ }
+ }
+ return found;
+}
+
+/*
+ * Similar to dn_ht_scan(), except thah the scan is performed only
+ * in the bucket 'bucket'. The function returns a correct bucket number if
+ * the original is invalid
+ */
+int
+dn_ht_scan_bucket(struct dn_ht *ht, int *bucket, int (*fn)(void *, void *),
+ void *arg)
+{
+ int i, ret, found = 0;
+ void **curp, *cur, *next;
+
+ if (ht == NULL || fn == NULL)
+ return 0;
+ if (*bucket > ht->buckets)
+ *bucket = 0;
+ i = *bucket;
+
+ curp = &ht->ht[i];
+ while ( (cur = *curp) != NULL) {
+ next = *(void **)((char *)cur + ht->ofs);
+ ret = fn(cur, arg);
+ if (ret & DNHT_SCAN_DEL) {
+ found++;
+ ht->entries--;
+ *curp = next;
+ } else {
+ curp = (void **)((char *)cur + ht->ofs);
+ }
+ if (ret & DNHT_SCAN_END)
+ return found;
+ }
+ return found;
+}
+
git://git.onelab.eu / ipfw.git / blobdiff