2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2012-2021 Marko Zec
5 * Copyright (c) 2005, 2018 University of Zagreb
6 * Copyright (c) 2005 International Computer Science Institute
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * An implementation of DXR, a simple IPv4 LPM scheme with compact lookup
32 * structures and a trivial search procedure. More significant bits of
33 * the search key are used to directly index a two-stage trie, while the
34 * remaining bits are used for finding the next hop in a sorted array.
37 * M. Zec, L. Rizzo, M. Mikuc, DXR: towards a billion routing lookups per
38 * second in software, ACM SIGCOMM Computer Communication Review, September
41 * M. Zec, M. Mikuc, Pushing the envelope: beyond two billion IP routing
42 * lookups per second on commodity CPUs, IEEE SoftCOM, September 2017, Split
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
50 #include <sys/param.h>
51 #include <sys/kernel.h>
52 #include <sys/epoch.h>
53 #include <sys/malloc.h>
54 #include <sys/module.h>
55 #include <sys/socket.h>
56 #include <sys/sysctl.h>
57 #include <sys/syslog.h>
61 #include <netinet/in.h>
62 #include <netinet/in_fib.h>
64 #include <net/route.h>
65 #include <net/route/route_ctl.h>
66 #include <net/route/fib_algo.h>
68 #define DXR_TRIE_BITS 20
70 CTASSERT(DXR_TRIE_BITS >= 16 && DXR_TRIE_BITS <= 24);
72 /* DXR2: two-stage primary trie, instead of a single direct lookup table */
75 #if DXR_TRIE_BITS > 16
78 #define DXR_D (DXR_TRIE_BITS - 1)
80 #define DXR_X (DXR_TRIE_BITS - DXR_D)
82 #define D_TBL_SIZE (1 << DXR_D)
83 #define DIRECT_TBL_SIZE (1 << DXR_TRIE_BITS)
84 #define DXR_RANGE_MASK (0xffffffffU >> DXR_TRIE_BITS)
85 #define DXR_RANGE_SHIFT (32 - DXR_TRIE_BITS)
87 #define DESC_BASE_BITS 22
88 #define DESC_FRAGMENTS_BITS (32 - DESC_BASE_BITS)
89 #define BASE_MAX ((1 << DESC_BASE_BITS) - 1)
90 #define RTBL_SIZE_INCR (BASE_MAX / 64)
92 #if DXR_TRIE_BITS < 24
93 #define FRAGS_MASK_SHORT ((1 << (23 - DXR_TRIE_BITS)) - 1)
95 #define FRAGS_MASK_SHORT 0
97 #define FRAGS_PREF_SHORT (((1 << DESC_FRAGMENTS_BITS) - 1) & \
99 #define FRAGS_MARK_XL (FRAGS_PREF_SHORT - 1)
100 #define FRAGS_MARK_HIT (FRAGS_PREF_SHORT - 2)
102 #define IS_SHORT_FORMAT(x) ((x & FRAGS_PREF_SHORT) == FRAGS_PREF_SHORT)
103 #define IS_LONG_FORMAT(x) ((x & FRAGS_PREF_SHORT) != FRAGS_PREF_SHORT)
104 #define IS_XL_FORMAT(x) (x == FRAGS_MARK_XL)
106 #define RE_SHORT_MAX_NH ((1 << (DXR_TRIE_BITS - 8)) - 1)
108 #define CHUNK_HASH_BITS 16
109 #define CHUNK_HASH_SIZE (1 << CHUNK_HASH_BITS)
110 #define CHUNK_HASH_MASK (CHUNK_HASH_SIZE - 1)
112 #define TRIE_HASH_BITS 16
113 #define TRIE_HASH_SIZE (1 << TRIE_HASH_BITS)
114 #define TRIE_HASH_MASK (TRIE_HASH_SIZE - 1)
116 #define XTBL_SIZE_INCR (DIRECT_TBL_SIZE / 16)
118 /* Lookup structure elements */
120 struct direct_entry {
121 uint32_t fragments: DESC_FRAGMENTS_BITS,
122 base: DESC_BASE_BITS;
125 struct range_entry_long {
126 uint32_t start: DXR_RANGE_SHIFT,
127 nexthop: DXR_TRIE_BITS;
130 #if DXR_TRIE_BITS < 24
131 struct range_entry_short {
132 uint16_t start: DXR_RANGE_SHIFT - 8,
133 nexthop: DXR_TRIE_BITS - 8;
137 /* Auxiliary structures */
147 LIST_ENTRY(chunk_desc) cd_all_le;
148 LIST_ENTRY(chunk_desc) cd_hash_le;
152 uint32_t cd_cur_size;
153 uint32_t cd_max_size;
157 LIST_ENTRY(trie_desc) td_all_le;
158 LIST_ENTRY(trie_desc) td_hash_le;
165 /* Glue to external state */
170 /* Auxiliary build-time tables */
171 struct direct_entry direct_tbl[DIRECT_TBL_SIZE];
172 uint16_t d_tbl[D_TBL_SIZE];
173 struct direct_entry *x_tbl;
175 struct range_entry_long re;
179 /* Auxiliary internal state */
180 uint32_t updates_mask[DIRECT_TBL_SIZE / 32];
181 struct trie_desc *trietbl[D_TBL_SIZE];
182 LIST_HEAD(, chunk_desc) chunk_hashtbl[CHUNK_HASH_SIZE];
183 LIST_HEAD(, chunk_desc) all_chunks;
184 LIST_HEAD(, chunk_desc) unused_chunks; /* abuses hash link entry */
185 LIST_HEAD(, trie_desc) trie_hashtbl[TRIE_HASH_SIZE];
186 LIST_HEAD(, trie_desc) all_trie;
187 LIST_HEAD(, trie_desc) unused_trie; /* abuses hash link entry */
188 struct sockaddr_in dst;
189 struct sockaddr_in mask;
190 struct heap_entry heap[33];
192 uint32_t updates_low;
193 uint32_t updates_high;
194 uint32_t all_chunks_cnt;
195 uint32_t unused_chunks_cnt;
197 uint32_t all_trie_cnt;
198 uint32_t unused_trie_cnt;
199 uint32_t trie_rebuilt_prefixes;
204 uint32_t rtbl_work_frags;
208 /* Main lookup structure container */
218 struct nhop_object **nh_tbl;
220 /* Glue to external state */
223 struct epoch_context epoch_ctx;
227 static MALLOC_DEFINE(M_DXRLPM, "dxr", "DXR LPM");
228 static MALLOC_DEFINE(M_DXRAUX, "dxr aux", "DXR auxiliary");
230 uma_zone_t chunk_zone;
231 uma_zone_t trie_zone;
233 SYSCTL_DECL(_net_route_algo);
234 SYSCTL_NODE(_net_route_algo, OID_AUTO, dxr, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
237 VNET_DEFINE_STATIC(int, max_trie_holes) = 8;
238 #define V_max_trie_holes VNET(max_trie_holes)
239 SYSCTL_INT(_net_route_algo_dxr, OID_AUTO, max_trie_holes,
240 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(max_trie_holes), 0,
241 "Trie fragmentation threshold before triggering a full rebuild");
243 VNET_DEFINE_STATIC(int, max_range_holes) = 16;
244 #define V_max_range_holes VNET(max_range_holes)
245 SYSCTL_INT(_net_route_algo_dxr, OID_AUTO, max_range_holes,
246 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(max_range_holes), 0,
247 "Range table fragmentation threshold before triggering a full rebuild");
249 /* Binary search for a matching address range */
250 #define DXR_LOOKUP_STAGE \
251 if (masked_dst < range[middle].start) { \
252 upperbound = middle; \
253 middle = (middle + lowerbound) / 2; \
254 } else if (masked_dst < range[middle + 1].start) \
255 return (range[middle].nexthop); \
257 lowerbound = middle + 1; \
258 middle = (upperbound + middle + 1) / 2; \
260 if (upperbound == lowerbound) \
261 return (range[lowerbound].nexthop);
264 dxr_lookup(struct dxr *dxr, uint32_t dst)
267 uint16_t *dt = dxr->d;
268 struct direct_entry *xt = dxr->x;
271 struct direct_entry *dt = dxr->d;
273 struct direct_entry de;
274 struct range_entry_long *rt;
282 xi = (dt[dst >> dxr->d_shift] << dxr->x_shift) +
283 ((dst >> DXR_RANGE_SHIFT) & dxr->x_mask);
286 de = dt[dst >> DXR_RANGE_SHIFT];
289 if (__predict_true(de.fragments == FRAGS_MARK_HIT))
295 masked_dst = dst & DXR_RANGE_MASK;
297 #if DXR_TRIE_BITS < 24
298 if (__predict_true(IS_SHORT_FORMAT(de.fragments))) {
299 upperbound = de.fragments & FRAGS_MASK_SHORT;
300 struct range_entry_short *range =
301 (struct range_entry_short *) &rt[base];
305 upperbound = upperbound * 2 + 1;
314 upperbound = de.fragments;
315 middle = upperbound / 2;
316 struct range_entry_long *range = &rt[base];
317 if (__predict_false(IS_XL_FORMAT(de.fragments))) {
318 upperbound = *((uint32_t *) range);
320 middle = upperbound / 2;
330 initheap(struct dxr_aux *da, uint32_t dst_u32, uint32_t chunk)
332 struct heap_entry *fhp = &da->heap[0];
334 struct route_nhop_data rnd;
337 da->dst.sin_addr.s_addr = htonl(dst_u32);
338 rt = fib4_lookup_rt(da->fibnum, da->dst.sin_addr, 0, NHR_UNLOCKED,
344 rt_get_inet_prefix_plen(rt, &addr, &fhp->preflen, &scopeid);
345 fhp->start = ntohl(addr.s_addr);
346 fhp->end = fhp->start;
347 if (fhp->preflen < 32)
348 fhp->end |= (0xffffffffU >> fhp->preflen);
349 fhp->nexthop = fib_get_nhop_idx(da->fd, rnd.rnd_nhop);
351 fhp->preflen = fhp->nexthop = fhp->start = 0;
352 fhp->end = 0xffffffffU;
357 chunk_size(struct dxr_aux *da, struct direct_entry *fdesc)
360 if (IS_SHORT_FORMAT(fdesc->fragments))
361 return ((fdesc->fragments & FRAGS_MASK_SHORT) + 1);
362 else if (IS_XL_FORMAT(fdesc->fragments))
363 return (da->range_tbl[fdesc->base].fragments + 2);
364 else /* if (IS_LONG_FORMAT(fdesc->fragments)) */
365 return (fdesc->fragments + 1);
369 chunk_hash(struct dxr_aux *da, struct direct_entry *fdesc)
371 uint32_t size = chunk_size(da, fdesc);
372 uint32_t *p = (uint32_t *) &da->range_tbl[fdesc->base];
373 uint32_t *l = (uint32_t *) &da->range_tbl[fdesc->base + size];
374 uint32_t hash = fdesc->fragments;
377 hash = (hash << 7) + (hash >> 13) + *p;
379 return (hash + (hash >> 16));
383 chunk_ref(struct dxr_aux *da, uint32_t chunk)
385 struct direct_entry *fdesc = &da->direct_tbl[chunk];
386 struct chunk_desc *cdp, *empty_cdp;
387 uint32_t base = fdesc->base;
388 uint32_t size = chunk_size(da, fdesc);
389 uint32_t hash = chunk_hash(da, fdesc);
391 /* Find an existing descriptor */
392 LIST_FOREACH(cdp, &da->chunk_hashtbl[hash & CHUNK_HASH_MASK],
394 if (cdp->cd_hash != hash || cdp->cd_cur_size != size ||
395 memcmp(&da->range_tbl[base], &da->range_tbl[cdp->cd_base],
396 sizeof(struct range_entry_long) * size))
398 da->rtbl_top = fdesc->base;
399 fdesc->base = cdp->cd_base;
404 /* No matching chunks found. Recycle an empty or allocate a new one */
406 LIST_FOREACH(empty_cdp, &da->unused_chunks, cd_hash_le)
407 if (empty_cdp->cd_max_size >= size && (cdp == NULL ||
408 empty_cdp->cd_max_size < cdp->cd_max_size)) {
410 if (empty_cdp->cd_max_size == size)
415 /* Copy from heap into the recycled chunk */
416 bcopy(&da->range_tbl[fdesc->base], &da->range_tbl[cdp->cd_base],
417 size * sizeof(struct range_entry_long));
418 fdesc->base = cdp->cd_base;
419 da->rtbl_top -= size;
420 da->unused_chunks_cnt--;
421 if (cdp->cd_max_size > size + 1) {
422 /* Split the range in two, need a new descriptor */
423 empty_cdp = uma_zalloc(chunk_zone, M_NOWAIT);
424 if (empty_cdp == NULL)
426 empty_cdp->cd_max_size = cdp->cd_max_size - size;
427 empty_cdp->cd_base = cdp->cd_base + size;
428 LIST_INSERT_AFTER(cdp, empty_cdp, cd_all_le);
429 LIST_INSERT_AFTER(cdp, empty_cdp, cd_hash_le);
430 da->all_chunks_cnt++;
431 da->unused_chunks_cnt++;
432 cdp->cd_max_size = size;
434 LIST_REMOVE(cdp, cd_hash_le);
436 /* Alloc a new descriptor */
437 cdp = uma_zalloc(chunk_zone, M_NOWAIT);
440 cdp->cd_max_size = size;
441 cdp->cd_base = fdesc->base;
442 LIST_INSERT_HEAD(&da->all_chunks, cdp, cd_all_le);
443 da->all_chunks_cnt++;
448 cdp->cd_cur_size = size;
449 LIST_INSERT_HEAD(&da->chunk_hashtbl[hash & CHUNK_HASH_MASK], cdp,
451 if (da->rtbl_top >= da->rtbl_size) {
452 if (da->rtbl_top >= BASE_MAX) {
453 FIB_PRINTF(LOG_ERR, da->fd,
454 "structural limit exceeded at %d "
455 "range table elements", da->rtbl_top);
458 da->rtbl_size += RTBL_SIZE_INCR;
459 if (da->rtbl_top >= BASE_MAX / 4)
460 FIB_PRINTF(LOG_WARNING, da->fd, "range table at %d%%",
461 da->rtbl_top * 100 / BASE_MAX);
462 da->range_tbl = realloc(da->range_tbl,
463 sizeof(*da->range_tbl) * da->rtbl_size + FRAGS_PREF_SHORT,
465 if (da->range_tbl == NULL)
473 chunk_unref(struct dxr_aux *da, uint32_t chunk)
475 struct direct_entry *fdesc = &da->direct_tbl[chunk];
476 struct chunk_desc *cdp;
477 uint32_t base = fdesc->base;
478 uint32_t size = chunk_size(da, fdesc);
479 uint32_t hash = chunk_hash(da, fdesc);
481 /* Find an existing descriptor */
482 LIST_FOREACH(cdp, &da->chunk_hashtbl[hash & CHUNK_HASH_MASK],
484 if (cdp->cd_hash == hash && cdp->cd_cur_size == size &&
485 memcmp(&da->range_tbl[base], &da->range_tbl[cdp->cd_base],
486 sizeof(struct range_entry_long) * size) == 0)
489 KASSERT(cdp != NULL, ("dxr: dangling chunk"));
490 if (--cdp->cd_refcnt > 0)
493 LIST_REMOVE(cdp, cd_hash_le);
494 da->unused_chunks_cnt++;
495 if (cdp->cd_base + cdp->cd_max_size != da->rtbl_top) {
496 LIST_INSERT_HEAD(&da->unused_chunks, cdp, cd_hash_le);
501 da->all_chunks_cnt--;
502 da->unused_chunks_cnt--;
503 da->rtbl_top -= cdp->cd_max_size;
504 LIST_REMOVE(cdp, cd_all_le);
505 uma_zfree(chunk_zone, cdp);
506 LIST_FOREACH(cdp, &da->unused_chunks, cd_hash_le)
507 if (cdp->cd_base + cdp->cd_max_size == da->rtbl_top) {
508 LIST_REMOVE(cdp, cd_hash_le);
511 } while (cdp != NULL);
516 trie_hash(struct dxr_aux *da, uint32_t dxr_x, uint32_t index)
521 for (i = 0; i < (1 << dxr_x); i++) {
522 hash = (hash << 3) ^ (hash >> 3);
524 (void *) &da->direct_tbl[(index << dxr_x) + i];
529 return (hash + (hash >> 16));
533 trie_ref(struct dxr_aux *da, uint32_t index)
535 struct trie_desc *tp;
536 uint32_t dxr_d = da->d_bits;
537 uint32_t dxr_x = DXR_TRIE_BITS - dxr_d;
538 uint32_t hash = trie_hash(da, dxr_x, index);
540 /* Find an existing descriptor */
541 LIST_FOREACH(tp, &da->trie_hashtbl[hash & TRIE_HASH_MASK], td_hash_le)
542 if (tp->td_hash == hash &&
543 memcmp(&da->direct_tbl[index << dxr_x],
544 &da->x_tbl[tp->td_index << dxr_x],
545 sizeof(*da->x_tbl) << dxr_x) == 0) {
547 da->trietbl[index] = tp;
548 return(tp->td_index);
551 tp = LIST_FIRST(&da->unused_trie);
553 LIST_REMOVE(tp, td_hash_le);
554 da->unused_trie_cnt--;
556 tp = uma_zalloc(trie_zone, M_NOWAIT);
559 LIST_INSERT_HEAD(&da->all_trie, tp, td_all_le);
560 tp->td_index = da->all_trie_cnt++;
565 LIST_INSERT_HEAD(&da->trie_hashtbl[hash & TRIE_HASH_MASK], tp,
567 memcpy(&da->x_tbl[tp->td_index << dxr_x],
568 &da->direct_tbl[index << dxr_x], sizeof(*da->x_tbl) << dxr_x);
569 da->trietbl[index] = tp;
570 if (da->all_trie_cnt >= da->xtbl_size >> dxr_x) {
571 da->xtbl_size += XTBL_SIZE_INCR;
572 da->x_tbl = realloc(da->x_tbl,
573 sizeof(*da->x_tbl) * da->xtbl_size, M_DXRAUX, M_NOWAIT);
574 if (da->x_tbl == NULL)
577 return(tp->td_index);
581 trie_unref(struct dxr_aux *da, uint32_t index)
583 struct trie_desc *tp = da->trietbl[index];
587 da->trietbl[index] = NULL;
588 if (--tp->td_refcnt > 0)
591 LIST_REMOVE(tp, td_hash_le);
592 da->unused_trie_cnt++;
593 if (tp->td_index != da->all_trie_cnt - 1) {
594 LIST_INSERT_HEAD(&da->unused_trie, tp, td_hash_le);
600 da->unused_trie_cnt--;
601 LIST_REMOVE(tp, td_all_le);
602 uma_zfree(trie_zone, tp);
603 LIST_FOREACH(tp, &da->unused_trie, td_hash_le)
604 if (tp->td_index == da->all_trie_cnt - 1) {
605 LIST_REMOVE(tp, td_hash_le);
608 } while (tp != NULL);
613 heap_inject(struct dxr_aux *da, uint32_t start, uint32_t end, uint32_t preflen,
616 struct heap_entry *fhp;
619 for (i = da->heap_index; i >= 0; i--) {
620 if (preflen > da->heap[i].preflen)
622 else if (preflen < da->heap[i].preflen)
623 da->heap[i + 1] = da->heap[i];
628 fhp = &da->heap[i + 1];
629 fhp->preflen = preflen;
637 dxr_walk(struct rtentry *rt, void *arg)
639 struct dxr_aux *da = arg;
640 uint32_t chunk = da->work_chunk;
641 uint32_t first = chunk << DXR_RANGE_SHIFT;
642 uint32_t last = first | DXR_RANGE_MASK;
643 struct range_entry_long *fp =
644 &da->range_tbl[da->rtbl_top + da->rtbl_work_frags].re;
645 struct heap_entry *fhp = &da->heap[da->heap_index];
646 uint32_t preflen, nh, start, end, scopeid;
649 rt_get_inet_prefix_plen(rt, &addr, &preflen, &scopeid);
650 start = ntohl(addr.s_addr);
652 return (-1); /* Beyond chunk boundaries, we are done */
654 return (0); /* Skip this route */
658 end |= (0xffffffffU >> preflen);
659 nh = fib_get_nhop_idx(da->fd, rt_get_raw_nhop(rt));
661 if (start == fhp->start)
662 heap_inject(da, start, end, preflen, nh);
664 /* start > fhp->start */
665 while (start > fhp->end) {
666 uint32_t oend = fhp->end;
668 if (da->heap_index > 0) {
672 initheap(da, fhp->end + 1, chunk);
673 if (fhp->end > oend && fhp->nexthop != fp->nexthop) {
675 da->rtbl_work_frags++;
676 fp->start = (oend + 1) & DXR_RANGE_MASK;
677 fp->nexthop = fhp->nexthop;
680 if (start > ((chunk << DXR_RANGE_SHIFT) | fp->start) &&
683 da->rtbl_work_frags++;
684 fp->start = start & DXR_RANGE_MASK;
685 } else if (da->rtbl_work_frags) {
686 if ((--fp)->nexthop == nh)
687 da->rtbl_work_frags--;
692 heap_inject(da, start, end, preflen, nh);
699 update_chunk(struct dxr_aux *da, uint32_t chunk)
701 struct range_entry_long *fp;
702 #if DXR_TRIE_BITS < 24
703 struct range_entry_short *fps;
704 uint32_t start, nh, i;
706 struct heap_entry *fhp;
707 uint32_t first = chunk << DXR_RANGE_SHIFT;
708 uint32_t last = first | DXR_RANGE_MASK;
710 if (da->direct_tbl[chunk].fragments != FRAGS_MARK_HIT)
711 chunk_unref(da, chunk);
713 initheap(da, first, chunk);
715 fp = &da->range_tbl[da->rtbl_top].re;
716 da->rtbl_work_frags = 0;
717 fp->start = first & DXR_RANGE_MASK;
718 fp->nexthop = da->heap[0].nexthop;
720 da->dst.sin_addr.s_addr = htonl(first);
721 da->mask.sin_addr.s_addr = htonl(~DXR_RANGE_MASK);
723 da->work_chunk = chunk;
724 rib_walk_from(da->fibnum, AF_INET, RIB_FLAG_LOCKED,
725 (struct sockaddr *) &da->dst, (struct sockaddr *) &da->mask,
728 /* Flush any remaining objects on the heap */
729 fp = &da->range_tbl[da->rtbl_top + da->rtbl_work_frags].re;
730 fhp = &da->heap[da->heap_index];
731 while (fhp->preflen > DXR_TRIE_BITS) {
732 uint32_t oend = fhp->end;
734 if (da->heap_index > 0) {
738 initheap(da, fhp->end + 1, chunk);
739 if (fhp->end > oend && fhp->nexthop != fp->nexthop) {
740 /* Have we crossed the upper chunk boundary? */
744 da->rtbl_work_frags++;
745 fp->start = (oend + 1) & DXR_RANGE_MASK;
746 fp->nexthop = fhp->nexthop;
750 /* Direct hit if the chunk contains only a single fragment */
751 if (da->rtbl_work_frags == 0) {
752 da->direct_tbl[chunk].base = fp->nexthop;
753 da->direct_tbl[chunk].fragments = FRAGS_MARK_HIT;
757 da->direct_tbl[chunk].base = da->rtbl_top;
758 da->direct_tbl[chunk].fragments = da->rtbl_work_frags;
760 #if DXR_TRIE_BITS < 24
761 /* Check whether the chunk can be more compactly encoded */
762 fp = &da->range_tbl[da->rtbl_top].re;
763 for (i = 0; i <= da->rtbl_work_frags; i++, fp++)
764 if ((fp->start & 0xff) != 0 || fp->nexthop > RE_SHORT_MAX_NH)
766 if (i == da->rtbl_work_frags + 1) {
767 fp = &da->range_tbl[da->rtbl_top].re;
769 for (i = 0; i <= da->rtbl_work_frags; i++, fp++, fps++) {
772 fps->start = start >> 8;
775 fps->start = start >> 8;
777 da->rtbl_work_frags >>= 1;
778 da->direct_tbl[chunk].fragments =
779 da->rtbl_work_frags | FRAGS_PREF_SHORT;
782 if (da->rtbl_work_frags >= FRAGS_MARK_HIT) {
783 da->direct_tbl[chunk].fragments = FRAGS_MARK_XL;
784 memmove(&da->range_tbl[da->rtbl_top + 1],
785 &da->range_tbl[da->rtbl_top],
786 (da->rtbl_work_frags + 1) * sizeof(*da->range_tbl));
787 da->range_tbl[da->rtbl_top].fragments = da->rtbl_work_frags;
788 da->rtbl_work_frags++;
790 da->rtbl_top += (da->rtbl_work_frags + 1);
791 return (chunk_ref(da, chunk));
795 dxr_build(struct dxr *dxr)
797 struct dxr_aux *da = dxr->aux;
798 struct chunk_desc *cdp;
799 struct rib_rtable_info rinfo;
800 struct timeval t0, t1, t2, t3;
801 uint32_t r_size, dxr_tot_size;
802 uint32_t i, m, range_rebuild = 0;
804 struct trie_desc *tp;
805 uint32_t d_tbl_size, dxr_x, d_size, x_size;
806 uint32_t ti, trie_rebuild = 0, prev_size = 0;
809 KASSERT(dxr->d == NULL, ("dxr: d not free"));
812 da = malloc(sizeof(*dxr->aux), M_DXRAUX, M_NOWAIT);
816 da->fibnum = dxr->fibnum;
818 LIST_INIT(&da->all_chunks);
819 LIST_INIT(&da->all_trie);
820 da->rtbl_size = RTBL_SIZE_INCR;
821 da->range_tbl = NULL;
822 da->xtbl_size = XTBL_SIZE_INCR;
824 bzero(&da->dst, sizeof(da->dst));
825 bzero(&da->mask, sizeof(da->mask));
826 da->dst.sin_len = sizeof(da->dst);
827 da->mask.sin_len = sizeof(da->mask);
828 da->dst.sin_family = AF_INET;
829 da->mask.sin_family = AF_INET;
831 if (da->range_tbl == NULL) {
832 da->range_tbl = malloc(sizeof(*da->range_tbl) * da->rtbl_size
833 + FRAGS_PREF_SHORT, M_DXRAUX, M_NOWAIT);
834 if (da->range_tbl == NULL)
839 if (da->x_tbl == NULL) {
840 da->x_tbl = malloc(sizeof(*da->x_tbl) * da->xtbl_size,
842 if (da->x_tbl == NULL)
851 dxr->nh_tbl = fib_get_nhop_array(da->fd);
852 fib_get_rtable_info(fib_get_rh(da->fd), &rinfo);
854 if (da->updates_low > da->updates_high ||
855 da->unused_chunks_cnt > V_max_range_holes)
859 bzero(da->chunk_hashtbl, sizeof(da->chunk_hashtbl));
860 while ((cdp = LIST_FIRST(&da->all_chunks)) != NULL) {
861 LIST_REMOVE(cdp, cd_all_le);
862 uma_zfree(chunk_zone, cdp);
864 LIST_INIT(&da->unused_chunks);
865 da->all_chunks_cnt = da->unused_chunks_cnt = 0;
868 da->updates_high = DIRECT_TBL_SIZE - 1;
869 memset(da->updates_mask, 0xff, sizeof(da->updates_mask));
870 for (i = 0; i < DIRECT_TBL_SIZE; i++) {
871 da->direct_tbl[i].fragments = FRAGS_MARK_HIT;
872 da->direct_tbl[i].base = 0;
875 da->prefixes = rinfo.num_prefixes;
877 /* DXR: construct direct & range table */
878 for (i = da->updates_low; i <= da->updates_high; i++) {
879 m = da->updates_mask[i >> 5] >> (i & 0x1f);
882 else if (m & 1 && update_chunk(da, i) != 0)
885 r_size = sizeof(*da->range_tbl) * da->rtbl_top;
889 if (range_rebuild || da->unused_trie_cnt > V_max_trie_holes ||
890 abs(fls(da->prefixes) - fls(da->trie_rebuilt_prefixes)) > 1)
893 da->trie_rebuilt_prefixes = da->prefixes;
896 da->updates_high = DIRECT_TBL_SIZE - 1;
902 bzero(da->trietbl, sizeof(da->trietbl));
903 bzero(da->trie_hashtbl, sizeof(da->trie_hashtbl));
904 while ((tp = LIST_FIRST(&da->all_trie)) != NULL) {
905 LIST_REMOVE(tp, td_all_le);
906 uma_zfree(trie_zone, tp);
908 LIST_INIT(&da->unused_trie);
909 da->all_trie_cnt = da->unused_trie_cnt = 0;
912 /* Populate d_tbl, x_tbl */
913 dxr_x = DXR_TRIE_BITS - da->d_bits;
914 d_tbl_size = (1 << da->d_bits);
916 for (i = da->updates_low >> dxr_x; i <= da->updates_high >> dxr_x;
919 ti = trie_ref(da, i);
925 d_size = sizeof(*da->d_tbl) * d_tbl_size;
926 x_size = sizeof(*da->x_tbl) * DIRECT_TBL_SIZE / d_tbl_size
928 dxr_tot_size = d_size + x_size + r_size;
930 if (trie_rebuild == 1) {
931 /* Try to find a more compact D/X split */
932 if (prev_size == 0 || dxr_tot_size <= prev_size)
938 prev_size = dxr_tot_size;
939 goto dxr2_try_squeeze;
943 dxr_tot_size = sizeof(da->direct_tbl) + r_size;
947 dxr->d = malloc(dxr_tot_size, M_DXRLPM, M_NOWAIT);
951 memcpy(dxr->d, da->d_tbl, d_size);
952 dxr->x = ((char *) dxr->d) + d_size;
953 memcpy(dxr->x, da->x_tbl, x_size);
954 dxr->r = ((char *) dxr->x) + x_size;
955 dxr->d_shift = 32 - da->d_bits;
956 dxr->x_shift = dxr_x;
957 dxr->x_mask = 0xffffffffU >> (32 - dxr_x);
959 memcpy(dxr->d, da->direct_tbl, sizeof(da->direct_tbl));
960 dxr->r = ((char *) dxr->d) + sizeof(da->direct_tbl);
962 memcpy(dxr->r, da->range_tbl, r_size);
964 if (da->updates_low <= da->updates_high)
965 bzero(&da->updates_mask[da->updates_low / 32],
966 (da->updates_high - da->updates_low) / 8 + 1);
967 da->updates_low = DIRECT_TBL_SIZE - 1;
968 da->updates_high = 0;
972 FIB_PRINTF(LOG_INFO, da->fd, "D%dX%dR, %d prefixes, %d nhops (max)",
973 da->d_bits, dxr_x, rinfo.num_prefixes, rinfo.num_nhops);
975 FIB_PRINTF(LOG_INFO, da->fd, "D%dR, %d prefixes, %d nhops (max)",
976 DXR_D, rinfo.num_prefixes, rinfo.num_nhops);
978 i = dxr_tot_size * 100 / rinfo.num_prefixes;
979 FIB_PRINTF(LOG_INFO, da->fd, "%d.%02d KBytes, %d.%02d Bytes/prefix",
980 dxr_tot_size / 1024, dxr_tot_size * 100 / 1024 % 100,
982 i = (t1.tv_sec - t0.tv_sec) * 1000000 + t1.tv_usec - t0.tv_usec;
983 FIB_PRINTF(LOG_INFO, da->fd, "range table %s in %u.%03u ms",
984 range_rebuild ? "rebuilt" : "updated", i / 1000, i % 1000);
986 i = (t2.tv_sec - t1.tv_sec) * 1000000 + t2.tv_usec - t1.tv_usec;
987 FIB_PRINTF(LOG_INFO, da->fd, "trie %s in %u.%03u ms",
988 trie_rebuild ? "rebuilt" : "updated", i / 1000, i % 1000);
990 i = (t3.tv_sec - t2.tv_sec) * 1000000 + t3.tv_usec - t2.tv_usec;
991 FIB_PRINTF(LOG_INFO, da->fd, "snapshot forked in %u.%03u ms",
993 FIB_PRINTF(LOG_INFO, da->fd, "range table: %d%%, %d chunks, %d holes",
994 da->rtbl_top * 100 / BASE_MAX, da->all_chunks_cnt,
995 da->unused_chunks_cnt);
999 * Glue functions for attaching to FreeBSD 13 fib_algo infrastructure.
1002 static struct nhop_object *
1003 dxr_fib_lookup(void *algo_data, const struct flm_lookup_key key,
1006 struct dxr *dxr = algo_data;
1009 nh = dxr_lookup(dxr, ntohl(key.addr4.s_addr));
1011 return (dxr->nh_tbl[nh]);
1014 static enum flm_op_result
1015 dxr_init(uint32_t fibnum, struct fib_data *fd, void *old_data, void **data)
1017 struct dxr *old_dxr = old_data;
1018 struct dxr_aux *da = NULL;
1021 dxr = malloc(sizeof(*dxr), M_DXRAUX, M_NOWAIT);
1023 return (FLM_REBUILD);
1025 /* Check whether we may reuse the old auxiliary structures */
1026 if (old_dxr != NULL && old_dxr->aux != NULL) {
1028 atomic_add_int(&da->refcnt, 1);
1034 dxr->fibnum = fibnum;
1037 return (FLM_SUCCESS);
1041 dxr_destroy(void *data)
1043 struct dxr *dxr = data;
1045 struct chunk_desc *cdp;
1046 struct trie_desc *tp;
1049 free(dxr->d, M_DXRLPM);
1052 free(dxr, M_DXRAUX);
1054 if (da == NULL || atomic_fetchadd_int(&da->refcnt, -1) > 1)
1057 /* Release auxiliary structures */
1058 while ((cdp = LIST_FIRST(&da->all_chunks)) != NULL) {
1059 LIST_REMOVE(cdp, cd_all_le);
1060 uma_zfree(chunk_zone, cdp);
1062 while ((tp = LIST_FIRST(&da->all_trie)) != NULL) {
1063 LIST_REMOVE(tp, td_all_le);
1064 uma_zfree(trie_zone, tp);
1066 free(da->range_tbl, M_DXRAUX);
1067 free(da->x_tbl, M_DXRAUX);
1072 epoch_dxr_destroy(epoch_context_t ctx)
1074 struct dxr *dxr = __containerof(ctx, struct dxr, epoch_ctx);
1079 static enum flm_op_result
1080 dxr_dump_end(void *data, struct fib_dp *dp)
1082 struct dxr *dxr = data;
1089 return (FLM_REBUILD);
1091 /* Structural limit exceeded, hard error */
1092 if (da->rtbl_top >= BASE_MAX)
1095 /* A malloc(,, M_NOWAIT) failed somewhere, retry later */
1097 return (FLM_REBUILD);
1099 dp->f = dxr_fib_lookup;
1102 return (FLM_SUCCESS);
1105 static enum flm_op_result
1106 dxr_dump_rib_item(struct rtentry *rt, void *data)
1109 return (FLM_SUCCESS);
1112 static enum flm_op_result
1113 dxr_change_rib_item(struct rib_head *rnh, struct rib_cmd_info *rc,
1120 static enum flm_op_result
1121 dxr_change_rib_batch(struct rib_head *rnh, struct fib_change_queue *q,
1124 struct dxr *dxr = data;
1125 struct dxr *new_dxr;
1127 struct fib_dp new_dp;
1128 enum flm_op_result res;
1129 uint32_t ip, plen, hmask, start, end, i, ui;
1131 struct rib_rtable_info rinfo;
1132 int update_delta = 0;
1135 KASSERT(data != NULL, ("%s: NULL data", __FUNCTION__));
1136 KASSERT(q != NULL, ("%s: NULL q", __FUNCTION__));
1137 KASSERT(q->count < q->size, ("%s: q->count %d q->size %d",
1138 __FUNCTION__, q->count, q->size));
1141 KASSERT(da != NULL, ("%s: NULL dxr->aux", __FUNCTION__));
1143 FIB_PRINTF(LOG_INFO, da->fd, "processing %d update(s)", q->count);
1144 for (ui = 0; ui < q->count; ui++) {
1146 if (q->entries[ui].nh_new != NULL)
1148 if (q->entries[ui].nh_old != NULL)
1151 plen = q->entries[ui].plen;
1152 ip = ntohl(q->entries[ui].addr4.s_addr);
1153 hmask = 0xffffffffU >> plen;
1154 start = (ip & ~hmask) >> DXR_RANGE_SHIFT;
1155 end = (ip | hmask) >> DXR_RANGE_SHIFT;
1157 if ((start & 0x1f) == 0 && (end & 0x1f) == 0x1f)
1158 for (i = start >> 5; i <= end >> 5; i++)
1159 da->updates_mask[i] = 0xffffffffU;
1161 for (i = start; i <= end; i++)
1162 da->updates_mask[i >> 5] |= (1 << (i & 0x1f));
1163 if (start < da->updates_low)
1164 da->updates_low = start;
1165 if (end > da->updates_high)
1166 da->updates_high = end;
1170 fib_get_rtable_info(fib_get_rh(da->fd), &rinfo);
1171 KASSERT(da->prefixes + update_delta == rinfo.num_prefixes,
1172 ("%s: update count mismatch", __FUNCTION__));
1175 res = dxr_init(0, dxr->fd, data, (void **) &new_dxr);
1176 if (res != FLM_SUCCESS)
1181 /* Structural limit exceeded, hard error */
1182 if (da->rtbl_top >= BASE_MAX) {
1183 dxr_destroy(new_dxr);
1187 /* A malloc(,, M_NOWAIT) failed somewhere, retry later */
1188 if (new_dxr->d == NULL) {
1189 dxr_destroy(new_dxr);
1190 return (FLM_REBUILD);
1193 new_dp.f = dxr_fib_lookup;
1194 new_dp.arg = new_dxr;
1195 if (fib_set_datapath_ptr(dxr->fd, &new_dp)) {
1196 fib_set_algo_ptr(dxr->fd, new_dxr);
1197 fib_epoch_call(epoch_dxr_destroy, &dxr->epoch_ctx);
1198 return (FLM_SUCCESS);
1201 dxr_destroy(new_dxr);
1202 return (FLM_REBUILD);
1206 dxr_get_pref(const struct rib_rtable_info *rinfo)
1209 /* Below bsearch4 up to 10 prefixes. Always supersedes dpdk_lpm4. */
1213 static struct fib_lookup_module fib_dxr_mod = {
1215 .flm_family = AF_INET,
1216 .flm_init_cb = dxr_init,
1217 .flm_destroy_cb = dxr_destroy,
1218 .flm_dump_rib_item_cb = dxr_dump_rib_item,
1219 .flm_dump_end_cb = dxr_dump_end,
1220 .flm_change_rib_item_cb = dxr_change_rib_item,
1221 .flm_change_rib_items_cb = dxr_change_rib_batch,
1222 .flm_get_pref = dxr_get_pref,
1226 dxr_modevent(module_t mod, int type, void *unused)
1232 chunk_zone = uma_zcreate("dxr chunk", sizeof(struct chunk_desc),
1233 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1234 trie_zone = uma_zcreate("dxr trie", sizeof(struct trie_desc),
1235 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1236 fib_module_register(&fib_dxr_mod);
1239 error = fib_module_unregister(&fib_dxr_mod);
1242 uma_zdestroy(chunk_zone);
1243 uma_zdestroy(trie_zone);
1250 static moduledata_t dxr_mod = {"fib_dxr", dxr_modevent, 0};
1252 DECLARE_MODULE(fib_dxr, dxr_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
1253 MODULE_VERSION(fib_dxr, 1);