diff options
Diffstat (limited to 'sys/net/route/nhop_utils.c')
| -rw-r--r-- | sys/net/route/nhop_utils.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/sys/net/route/nhop_utils.c b/sys/net/route/nhop_utils.c new file mode 100644 index 000000000000..56bca99c9ed8 --- /dev/null +++ b/sys/net/route/nhop_utils.c @@ -0,0 +1,219 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2020 Alexander V. Chernikov + * + * 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); +#include "opt_inet.h" +#include "opt_route.h" +#include "opt_mpath.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/kernel.h> + +#include <net/route/nhop_utils.h> + +#define BLOCK_ITEMS (8 * sizeof(u_long)) /* Number of items for ffsl() */ + +#define _BLOCKS_TO_SZ(_blocks) ((size_t)(_blocks) * sizeof(u_long)) +#define _BLOCKS_TO_ITEMS(_blocks) ((uint32_t)(_blocks) * BLOCK_ITEMS) +#define _ITEMS_TO_BLOCKS(_items) ((_items) / BLOCK_ITEMS) + + +static void _bitmask_init_idx(void *index, uint32_t items); + +void +bitmask_init(struct bitmask_head *bh, void *idx, uint32_t num_items) +{ + + if (idx != NULL) + _bitmask_init_idx(idx, num_items); + + memset(bh, 0, sizeof(struct bitmask_head)); + bh->blocks = _ITEMS_TO_BLOCKS(num_items); + bh->idx = (u_long *)idx; +} + +uint32_t +bitmask_get_resize_items(const struct bitmask_head *bh) +{ + if ((bh->items_count * 2 > _BLOCKS_TO_ITEMS(bh->blocks)) && bh->items_count < 65536) + return (_BLOCKS_TO_ITEMS(bh->blocks) * 2); + + return (0); +} + +int +bitmask_should_resize(const struct bitmask_head *bh) +{ + + return (bitmask_get_resize_items(bh) != 0); +} + +#if 0 +uint32_t +_bitmask_get_blocks(uint32_t items) +{ + + return (items / BLOCK_ITEMS); +} +#endif + +size_t +bitmask_get_size(uint32_t items) +{ +#if _KERNEL + KASSERT((items % BLOCK_ITEMS) == 0, + ("bitmask size needs to power of 2 and greater or equal to %zu", + BLOCK_ITEMS)); +#else + assert((items % BLOCK_ITEMS) == 0); +#endif + + return (items / 8); +} + +static void +_bitmask_init_idx(void *_idx, uint32_t items) +{ + size_t size = bitmask_get_size(items); + u_long *idx = (u_long *)_idx; + + /* Mark all as free */ + memset(idx, 0xFF, size); + *idx &= ~(u_long)1; /* Always skip index 0 */ +} + + +/* + * _try_merge api to allow shrinking? + */ +int +bitmask_copy(const struct bitmask_head *bi, void *new_idx, uint32_t new_items) +{ + uint32_t new_blocks = _BLOCKS_TO_ITEMS(new_items); + + _bitmask_init_idx(new_idx, new_items); + + if (bi->blocks < new_blocks) { + /* extend current blocks */ + if (bi->blocks > 0) + memcpy(new_idx, bi->idx, _BLOCKS_TO_SZ(bi->blocks)); + return (0); + } else { + /* XXX: ensure all other blocks are non-zero */ + for (int i = new_blocks; i < bi->blocks; i++) { + } + + return (1); + } +} + +void +bitmask_swap(struct bitmask_head *bh, void *new_idx, uint32_t new_items, void **pidx) +{ + void *old_ptr; + + old_ptr = bh->idx; + + bh->idx = (u_long *)new_idx; + bh->blocks = _ITEMS_TO_BLOCKS(new_items); + + if (pidx != NULL) + *pidx = old_ptr; +} + +/* + * Allocate new index in given instance and stores in in @pidx. + * Returns 0 on success. + */ +int +bitmask_alloc_idx(struct bitmask_head *bi, uint16_t *pidx) +{ + u_long *mask; + int i, off, v; + + off = bi->free_off; + mask = &bi->idx[off]; + + for (i = off; i < bi->blocks; i++, mask++) { + if ((v = ffsl(*mask)) == 0) + continue; + + /* Mark as busy */ + *mask &= ~ ((u_long)1 << (v - 1)); + + bi->free_off = i; + + v = BLOCK_ITEMS * i + v - 1; + + *pidx = v; + bi->items_count++; + return (0); + } + + return (1); +} + +/* + * Removes index from given set. + * Returns 0 on success. + */ +int +bitmask_free_idx(struct bitmask_head *bi, uint16_t idx) +{ + u_long *mask; + int i, v; + + if (idx == 0) + return (1); + + i = idx / BLOCK_ITEMS; + v = idx % BLOCK_ITEMS; + + if (i >= bi->blocks) + return (1); + + mask = &bi->idx[i]; + + if ((*mask & ((u_long)1 << v)) != 0) + return (1); + + /* Mark as free */ + *mask |= (u_long)1 << v; + bi->items_count--; + + /* Update free offset */ + if (bi->free_off > i) + bi->free_off = i; + + return (0); +} + |