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1// SPDX-License-Identifier: GPL-2.0-only
2
3/* PIPAPO: PIle PAcket POlicies: set for arbitrary concatenations of ranges
4 *
5 * Copyright (c) 2019-2020 Red Hat GmbH
6 *
7 * Author: Stefano Brivio <sbrivio@redhat.com>
8 */
9
10/**
11 * DOC: Theory of Operation
12 *
13 *
14 * Problem
15 * -------
16 *
17 * Match packet bytes against entries composed of ranged or non-ranged packet
18 * field specifiers, mapping them to arbitrary references. For example:
19 *
20 * ::
21 *
22 * --- fields --->
23 * | [net],[port],[net]... => [reference]
24 * entries [net],[port],[net]... => [reference]
25 * | [net],[port],[net]... => [reference]
26 * V ...
27 *
28 * where [net] fields can be IP ranges or netmasks, and [port] fields are port
29 * ranges. Arbitrary packet fields can be matched.
30 *
31 *
32 * Algorithm Overview
33 * ------------------
34 *
35 * This algorithm is loosely inspired by [Ligatti 2010], and fundamentally
36 * relies on the consideration that every contiguous range in a space of b bits
37 * can be converted into b * 2 netmasks, from Theorem 3 in [Rottenstreich 2010],
38 * as also illustrated in Section 9 of [Kogan 2014].
39 *
40 * Classification against a number of entries, that require matching given bits
41 * of a packet field, is performed by grouping those bits in sets of arbitrary
42 * size, and classifying packet bits one group at a time.
43 *
44 * Example:
45 * to match the source port (16 bits) of a packet, we can divide those 16 bits
46 * in 4 groups of 4 bits each. Given the entry:
47 * 0000 0001 0101 1001
48 * and a packet with source port:
49 * 0000 0001 1010 1001
50 * first and second groups match, but the third doesn't. We conclude that the
51 * packet doesn't match the given entry.
52 *
53 * Translate the set to a sequence of lookup tables, one per field. Each table
54 * has two dimensions: bit groups to be matched for a single packet field, and
55 * all the possible values of said groups (buckets). Input entries are
56 * represented as one or more rules, depending on the number of composing
57 * netmasks for the given field specifier, and a group match is indicated as a
58 * set bit, with number corresponding to the rule index, in all the buckets
59 * whose value matches the entry for a given group.
60 *
61 * Rules are mapped between fields through an array of x, n pairs, with each
62 * item mapping a matched rule to one or more rules. The position of the pair in
63 * the array indicates the matched rule to be mapped to the next field, x
64 * indicates the first rule index in the next field, and n the amount of
65 * next-field rules the current rule maps to.
66 *
67 * The mapping array for the last field maps to the desired references.
68 *
69 * To match, we perform table lookups using the values of grouped packet bits,
70 * and use a sequence of bitwise operations to progressively evaluate rule
71 * matching.
72 *
73 * A stand-alone, reference implementation, also including notes about possible
74 * future optimisations, is available at:
75 * https://pipapo.lameexcu.se/
76 *
77 * Insertion
78 * ---------
79 *
80 * - For each packet field:
81 *
82 * - divide the b packet bits we want to classify into groups of size t,
83 * obtaining ceil(b / t) groups
84 *
85 * Example: match on destination IP address, with t = 4: 32 bits, 8 groups
86 * of 4 bits each
87 *
88 * - allocate a lookup table with one column ("bucket") for each possible
89 * value of a group, and with one row for each group
90 *
91 * Example: 8 groups, 2^4 buckets:
92 *
93 * ::
94 *
95 * bucket
96 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
97 * 0
98 * 1
99 * 2
100 * 3
101 * 4
102 * 5
103 * 6
104 * 7
105 *
106 * - map the bits we want to classify for the current field, for a given
107 * entry, to a single rule for non-ranged and netmask set items, and to one
108 * or multiple rules for ranges. Ranges are expanded to composing netmasks
109 * by pipapo_expand().
110 *
111 * Example: 2 entries, 10.0.0.5:1024 and 192.168.1.0-192.168.2.1:2048
112 * - rule #0: 10.0.0.5
113 * - rule #1: 192.168.1.0/24
114 * - rule #2: 192.168.2.0/31
115 *
116 * - insert references to the rules in the lookup table, selecting buckets
117 * according to bit values of a rule in the given group. This is done by
118 * pipapo_insert().
119 *
120 * Example: given:
121 * - rule #0: 10.0.0.5 mapping to buckets
122 * < 0 10 0 0 0 0 0 5 >
123 * - rule #1: 192.168.1.0/24 mapping to buckets
124 * < 12 0 10 8 0 1 < 0..15 > < 0..15 > >
125 * - rule #2: 192.168.2.0/31 mapping to buckets
126 * < 12 0 10 8 0 2 0 < 0..1 > >
127 *
128 * these bits are set in the lookup table:
129 *
130 * ::
131 *
132 * bucket
133 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
134 * 0 0 1,2
135 * 1 1,2 0
136 * 2 0 1,2
137 * 3 0 1,2
138 * 4 0,1,2
139 * 5 0 1 2
140 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
141 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1
142 *
143 * - if this is not the last field in the set, fill a mapping array that maps
144 * rules from the lookup table to rules belonging to the same entry in
145 * the next lookup table, done by pipapo_map().
146 *
147 * Note that as rules map to contiguous ranges of rules, given how netmask
148 * expansion and insertion is performed, &union nft_pipapo_map_bucket stores
149 * this information as pairs of first rule index, rule count.
150 *
151 * Example: 2 entries, 10.0.0.5:1024 and 192.168.1.0-192.168.2.1:2048,
152 * given lookup table #0 for field 0 (see example above):
153 *
154 * ::
155 *
156 * bucket
157 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
158 * 0 0 1,2
159 * 1 1,2 0
160 * 2 0 1,2
161 * 3 0 1,2
162 * 4 0,1,2
163 * 5 0 1 2
164 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
165 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1
166 *
167 * and lookup table #1 for field 1 with:
168 * - rule #0: 1024 mapping to buckets
169 * < 0 0 4 0 >
170 * - rule #1: 2048 mapping to buckets
171 * < 0 0 5 0 >
172 *
173 * ::
174 *
175 * bucket
176 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
177 * 0 0,1
178 * 1 0,1
179 * 2 0 1
180 * 3 0,1
181 *
182 * we need to map rules for 10.0.0.5 in lookup table #0 (rule #0) to 1024
183 * in lookup table #1 (rule #0) and rules for 192.168.1.0-192.168.2.1
184 * (rules #1, #2) to 2048 in lookup table #2 (rule #1):
185 *
186 * ::
187 *
188 * rule indices in current field: 0 1 2
189 * map to rules in next field: 0 1 1
190 *
191 * - if this is the last field in the set, fill a mapping array that maps
192 * rules from the last lookup table to element pointers, also done by
193 * pipapo_map().
194 *
195 * Note that, in this implementation, we have two elements (start, end) for
196 * each entry. The pointer to the end element is stored in this array, and
197 * the pointer to the start element is linked from it.
198 *
199 * Example: entry 10.0.0.5:1024 has a corresponding &struct nft_pipapo_elem
200 * pointer, 0x66, and element for 192.168.1.0-192.168.2.1:2048 is at 0x42.
201 * From the rules of lookup table #1 as mapped above:
202 *
203 * ::
204 *
205 * rule indices in last field: 0 1
bd97ad51 206 * map to elements: 0x66 0x42
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207 *
208 *
209 * Matching
210 * --------
211 *
212 * We use a result bitmap, with the size of a single lookup table bucket, to
213 * represent the matching state that applies at every algorithm step. This is
214 * done by pipapo_lookup().
215 *
216 * - For each packet field:
217 *
218 * - start with an all-ones result bitmap (res_map in pipapo_lookup())
219 *
220 * - perform a lookup into the table corresponding to the current field,
221 * for each group, and at every group, AND the current result bitmap with
222 * the value from the lookup table bucket
223 *
224 * ::
225 *
226 * Example: 192.168.1.5 < 12 0 10 8 0 1 0 5 >, with lookup table from
227 * insertion examples.
228 * Lookup table buckets are at least 3 bits wide, we'll assume 8 bits for
229 * convenience in this example. Initial result bitmap is 0xff, the steps
230 * below show the value of the result bitmap after each group is processed:
231 *
232 * bucket
233 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
234 * 0 0 1,2
235 * result bitmap is now: 0xff & 0x6 [bucket 12] = 0x6
236 *
237 * 1 1,2 0
238 * result bitmap is now: 0x6 & 0x6 [bucket 0] = 0x6
239 *
240 * 2 0 1,2
241 * result bitmap is now: 0x6 & 0x6 [bucket 10] = 0x6
242 *
243 * 3 0 1,2
244 * result bitmap is now: 0x6 & 0x6 [bucket 8] = 0x6
245 *
246 * 4 0,1,2
247 * result bitmap is now: 0x6 & 0x7 [bucket 0] = 0x6
248 *
249 * 5 0 1 2
250 * result bitmap is now: 0x6 & 0x2 [bucket 1] = 0x2
251 *
252 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
253 * result bitmap is now: 0x2 & 0x7 [bucket 0] = 0x2
254 *
255 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1
256 * final result bitmap for this field is: 0x2 & 0x3 [bucket 5] = 0x2
257 *
258 * - at the next field, start with a new, all-zeroes result bitmap. For each
259 * bit set in the previous result bitmap, fill the new result bitmap
260 * (fill_map in pipapo_lookup()) with the rule indices from the
261 * corresponding buckets of the mapping field for this field, done by
262 * pipapo_refill()
263 *
264 * Example: with mapping table from insertion examples, with the current
265 * result bitmap from the previous example, 0x02:
266 *
267 * ::
268 *
269 * rule indices in current field: 0 1 2
270 * map to rules in next field: 0 1 1
271 *
272 * the new result bitmap will be 0x02: rule 1 was set, and rule 1 will be
273 * set.
274 *
275 * We can now extend this example to cover the second iteration of the step
276 * above (lookup and AND bitmap): assuming the port field is
277 * 2048 < 0 0 5 0 >, with starting result bitmap 0x2, and lookup table
278 * for "port" field from pre-computation example:
279 *
280 * ::
281 *
282 * bucket
283 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
284 * 0 0,1
285 * 1 0,1
286 * 2 0 1
287 * 3 0,1
288 *
289 * operations are: 0x2 & 0x3 [bucket 0] & 0x3 [bucket 0] & 0x2 [bucket 5]
290 * & 0x3 [bucket 0], resulting bitmap is 0x2.
291 *
292 * - if this is the last field in the set, look up the value from the mapping
293 * array corresponding to the final result bitmap
294 *
295 * Example: 0x2 resulting bitmap from 192.168.1.5:2048, mapping array for
296 * last field from insertion example:
297 *
298 * ::
299 *
300 * rule indices in last field: 0 1
bd97ad51 301 * map to elements: 0x66 0x42
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302 *
303 * the matching element is at 0x42.
304 *
305 *
306 * References
307 * ----------
308 *
309 * [Ligatti 2010]
310 * A Packet-classification Algorithm for Arbitrary Bitmask Rules, with
311 * Automatic Time-space Tradeoffs
312 * Jay Ligatti, Josh Kuhn, and Chris Gage.
313 * Proceedings of the IEEE International Conference on Computer
314 * Communication Networks (ICCCN), August 2010.
50935339 315 * https://www.cse.usf.edu/~ligatti/papers/grouper-conf.pdf
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316 *
317 * [Rottenstreich 2010]
318 * Worst-Case TCAM Rule Expansion
319 * Ori Rottenstreich and Isaac Keslassy.
320 * 2010 Proceedings IEEE INFOCOM, San Diego, CA, 2010.
321 * http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.212.4592&rep=rep1&type=pdf
322 *
323 * [Kogan 2014]
324 * SAX-PAC (Scalable And eXpressive PAcket Classification)
325 * Kirill Kogan, Sergey Nikolenko, Ori Rottenstreich, William Culhane,
326 * and Patrick Eugster.
327 * Proceedings of the 2014 ACM conference on SIGCOMM, August 2014.
50935339 328 * https://www.sigcomm.org/sites/default/files/ccr/papers/2014/August/2619239-2626294.pdf
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329 */
330
331#include <linux/kernel.h>
332#include <linux/init.h>
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333#include <linux/module.h>
334#include <linux/netlink.h>
335#include <linux/netfilter.h>
336#include <linux/netfilter/nf_tables.h>
337#include <net/netfilter/nf_tables_core.h>
338#include <uapi/linux/netfilter/nf_tables.h>
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339#include <linux/bitmap.h>
340#include <linux/bitops.h>
341
7400b063 342#include "nft_set_pipapo_avx2.h"
8683f4b9 343#include "nft_set_pipapo.h"
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344
345/* Current working bitmap index, toggled between field matches */
346static DEFINE_PER_CPU(bool, nft_pipapo_scratch_index);
347
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348/**
349 * pipapo_refill() - For each set bit, set bits from selected mapping table item
350 * @map: Bitmap to be scanned for set bits
351 * @len: Length of bitmap in longs
352 * @rules: Number of rules in field
353 * @dst: Destination bitmap
354 * @mt: Mapping table containing bit set specifiers
355 * @match_only: Find a single bit and return, don't fill
356 *
357 * Iteration over set bits with __builtin_ctzl(): Daniel Lemire, public domain.
358 *
359 * For each bit set in map, select the bucket from mapping table with index
360 * corresponding to the position of the bit set. Use start bit and amount of
361 * bits specified in bucket to fill region in dst.
362 *
363 * Return: -1 on no match, bit position on 'match_only', 0 otherwise.
364 */
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365int pipapo_refill(unsigned long *map, int len, int rules, unsigned long *dst,
366 union nft_pipapo_map_bucket *mt, bool match_only)
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367{
368 unsigned long bitset;
369 int k, ret = -1;
370
371 for (k = 0; k < len; k++) {
372 bitset = map[k];
373 while (bitset) {
374 unsigned long t = bitset & -bitset;
375 int r = __builtin_ctzl(bitset);
376 int i = k * BITS_PER_LONG + r;
377
378 if (unlikely(i >= rules)) {
379 map[k] = 0;
380 return -1;
381 }
382
9a771204 383 if (match_only) {
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384 bitmap_clear(map, i, 1);
385 return i;
386 }
387
388 ret = 0;
389
390 bitmap_set(dst, mt[i].to, mt[i].n);
391
392 bitset ^= t;
393 }
394 map[k] = 0;
395 }
396
397 return ret;
398}
399
400/**
401 * nft_pipapo_lookup() - Lookup function
402 * @net: Network namespace
403 * @set: nftables API set representation
3db86c39 404 * @key: nftables API element representation containing key data
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405 * @ext: nftables API extension pointer, filled with matching reference
406 *
407 * For more details, see DOC: Theory of Operation.
408 *
409 * Return: true on match, false otherwise.
410 */
411static bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set,
412 const u32 *key, const struct nft_set_ext **ext)
413{
414 struct nft_pipapo *priv = nft_set_priv(set);
415 unsigned long *res_map, *fill_map;
416 u8 genmask = nft_genmask_cur(net);
417 const u8 *rp = (const u8 *)key;
418 struct nft_pipapo_match *m;
419 struct nft_pipapo_field *f;
420 bool map_index;
421 int i;
422
423 local_bh_disable();
424
425 map_index = raw_cpu_read(nft_pipapo_scratch_index);
426
427 m = rcu_dereference(priv->match);
428
429 if (unlikely(!m || !*raw_cpu_ptr(m->scratch)))
430 goto out;
431
432 res_map = *raw_cpu_ptr(m->scratch) + (map_index ? m->bsize_max : 0);
433 fill_map = *raw_cpu_ptr(m->scratch) + (map_index ? 0 : m->bsize_max);
434
435 memset(res_map, 0xff, m->bsize_max * sizeof(*res_map));
436
437 nft_pipapo_for_each_field(f, i, m) {
438 bool last = i == m->field_count - 1;
e807b13c 439 int b;
3c4287f6 440
e807b13c 441 /* For each bit group: select lookup table bucket depending on
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442 * packet bytes value, then AND bucket value
443 */
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444 if (likely(f->bb == 8))
445 pipapo_and_field_buckets_8bit(f, res_map, rp);
446 else
447 pipapo_and_field_buckets_4bit(f, res_map, rp);
448 NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4;
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449
450 rp += f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f);
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451
452 /* Now populate the bitmap for the next field, unless this is
453 * the last field, in which case return the matched 'ext'
454 * pointer if any.
455 *
456 * Now res_map contains the matching bitmap, and fill_map is the
457 * bitmap for the next field.
458 */
459next_match:
460 b = pipapo_refill(res_map, f->bsize, f->rules, fill_map, f->mt,
461 last);
462 if (b < 0) {
463 raw_cpu_write(nft_pipapo_scratch_index, map_index);
464 local_bh_enable();
465
466 return false;
467 }
468
469 if (last) {
470 *ext = &f->mt[b].e->ext;
471 if (unlikely(nft_set_elem_expired(*ext) ||
472 !nft_set_elem_active(*ext, genmask)))
473 goto next_match;
474
475 /* Last field: we're just returning the key without
476 * filling the initial bitmap for the next field, so the
477 * current inactive bitmap is clean and can be reused as
478 * *next* bitmap (not initial) for the next packet.
479 */
480 raw_cpu_write(nft_pipapo_scratch_index, map_index);
481 local_bh_enable();
482
483 return true;
484 }
485
486 /* Swap bitmap indices: res_map is the initial bitmap for the
487 * next field, and fill_map is guaranteed to be all-zeroes at
488 * this point.
489 */
490 map_index = !map_index;
491 swap(res_map, fill_map);
492
e807b13c 493 rp += NFT_PIPAPO_GROUPS_PADDING(f);
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494 }
495
496out:
497 local_bh_enable();
498 return false;
499}
500
501/**
502 * pipapo_get() - Get matching element reference given key data
503 * @net: Network namespace
504 * @set: nftables API set representation
505 * @data: Key data to be matched against existing elements
506 * @genmask: If set, check that element is active in given genmask
507 *
508 * This is essentially the same as the lookup function, except that it matches
509 * key data against the uncommitted copy and doesn't use preallocated maps for
510 * bitmap results.
511 *
512 * Return: pointer to &struct nft_pipapo_elem on match, error pointer otherwise.
513 */
514static struct nft_pipapo_elem *pipapo_get(const struct net *net,
515 const struct nft_set *set,
516 const u8 *data, u8 genmask)
517{
518 struct nft_pipapo_elem *ret = ERR_PTR(-ENOENT);
519 struct nft_pipapo *priv = nft_set_priv(set);
520 struct nft_pipapo_match *m = priv->clone;
521 unsigned long *res_map, *fill_map = NULL;
522 struct nft_pipapo_field *f;
523 int i;
524
525 res_map = kmalloc_array(m->bsize_max, sizeof(*res_map), GFP_ATOMIC);
526 if (!res_map) {
527 ret = ERR_PTR(-ENOMEM);
528 goto out;
529 }
530
531 fill_map = kcalloc(m->bsize_max, sizeof(*res_map), GFP_ATOMIC);
532 if (!fill_map) {
533 ret = ERR_PTR(-ENOMEM);
534 goto out;
535 }
536
537 memset(res_map, 0xff, m->bsize_max * sizeof(*res_map));
538
539 nft_pipapo_for_each_field(f, i, m) {
540 bool last = i == m->field_count - 1;
e807b13c 541 int b;
3c4287f6 542
e807b13c 543 /* For each bit group: select lookup table bucket depending on
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544 * packet bytes value, then AND bucket value
545 */
4051f431
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546 if (f->bb == 8)
547 pipapo_and_field_buckets_8bit(f, res_map, data);
548 else if (f->bb == 4)
e807b13c
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549 pipapo_and_field_buckets_4bit(f, res_map, data);
550 else
551 BUG();
3c4287f6 552
e807b13c 553 data += f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f);
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554
555 /* Now populate the bitmap for the next field, unless this is
556 * the last field, in which case return the matched 'ext'
557 * pointer if any.
558 *
559 * Now res_map contains the matching bitmap, and fill_map is the
560 * bitmap for the next field.
561 */
562next_match:
563 b = pipapo_refill(res_map, f->bsize, f->rules, fill_map, f->mt,
564 last);
565 if (b < 0)
566 goto out;
567
568 if (last) {
569 if (nft_set_elem_expired(&f->mt[b].e->ext) ||
570 (genmask &&
571 !nft_set_elem_active(&f->mt[b].e->ext, genmask)))
572 goto next_match;
573
574 ret = f->mt[b].e;
575 goto out;
576 }
577
e807b13c 578 data += NFT_PIPAPO_GROUPS_PADDING(f);
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579
580 /* Swap bitmap indices: fill_map will be the initial bitmap for
581 * the next field (i.e. the new res_map), and res_map is
582 * guaranteed to be all-zeroes at this point, ready to be filled
583 * according to the next mapping table.
584 */
585 swap(res_map, fill_map);
586 }
587
588out:
589 kfree(fill_map);
590 kfree(res_map);
591 return ret;
592}
593
594/**
595 * nft_pipapo_get() - Get matching element reference given key data
596 * @net: Network namespace
597 * @set: nftables API set representation
598 * @elem: nftables API element representation containing key data
599 * @flags: Unused
600 */
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601static void *nft_pipapo_get(const struct net *net, const struct nft_set *set,
602 const struct nft_set_elem *elem, unsigned int flags)
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603{
604 return pipapo_get(net, set, (const u8 *)elem->key.val.data,
605 nft_genmask_cur(net));
606}
607
608/**
609 * pipapo_resize() - Resize lookup or mapping table, or both
610 * @f: Field containing lookup and mapping tables
611 * @old_rules: Previous amount of rules in field
612 * @rules: New amount of rules
613 *
614 * Increase, decrease or maintain tables size depending on new amount of rules,
615 * and copy data over. In case the new size is smaller, throw away data for
616 * highest-numbered rules.
617 *
618 * Return: 0 on success, -ENOMEM on allocation failure.
619 */
620static int pipapo_resize(struct nft_pipapo_field *f, int old_rules, int rules)
621{
622 long *new_lt = NULL, *new_p, *old_lt = f->lt, *old_p;
623 union nft_pipapo_map_bucket *new_mt, *old_mt = f->mt;
624 size_t new_bucket_size, copy;
625 int group, bucket;
626
627 new_bucket_size = DIV_ROUND_UP(rules, BITS_PER_LONG);
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628#ifdef NFT_PIPAPO_ALIGN
629 new_bucket_size = roundup(new_bucket_size,
630 NFT_PIPAPO_ALIGN / sizeof(*new_lt));
631#endif
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632
633 if (new_bucket_size == f->bsize)
634 goto mt;
635
636 if (new_bucket_size > f->bsize)
637 copy = f->bsize;
638 else
639 copy = new_bucket_size;
640
e807b13c 641 new_lt = kvzalloc(f->groups * NFT_PIPAPO_BUCKETS(f->bb) *
bf3e5839
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642 new_bucket_size * sizeof(*new_lt) +
643 NFT_PIPAPO_ALIGN_HEADROOM,
644 GFP_KERNEL);
3c4287f6
SB
645 if (!new_lt)
646 return -ENOMEM;
647
bf3e5839
SB
648 new_p = NFT_PIPAPO_LT_ALIGN(new_lt);
649 old_p = NFT_PIPAPO_LT_ALIGN(old_lt);
650
3c4287f6 651 for (group = 0; group < f->groups; group++) {
e807b13c 652 for (bucket = 0; bucket < NFT_PIPAPO_BUCKETS(f->bb); bucket++) {
3c4287f6
SB
653 memcpy(new_p, old_p, copy * sizeof(*new_p));
654 new_p += copy;
655 old_p += copy;
656
657 if (new_bucket_size > f->bsize)
658 new_p += new_bucket_size - f->bsize;
659 else
660 old_p += f->bsize - new_bucket_size;
661 }
662 }
663
664mt:
665 new_mt = kvmalloc(rules * sizeof(*new_mt), GFP_KERNEL);
666 if (!new_mt) {
667 kvfree(new_lt);
668 return -ENOMEM;
669 }
670
671 memcpy(new_mt, f->mt, min(old_rules, rules) * sizeof(*new_mt));
672 if (rules > old_rules) {
673 memset(new_mt + old_rules, 0,
674 (rules - old_rules) * sizeof(*new_mt));
675 }
676
677 if (new_lt) {
678 f->bsize = new_bucket_size;
bf3e5839 679 NFT_PIPAPO_LT_ASSIGN(f, new_lt);
3c4287f6
SB
680 kvfree(old_lt);
681 }
682
683 f->mt = new_mt;
684 kvfree(old_mt);
685
686 return 0;
687}
688
689/**
690 * pipapo_bucket_set() - Set rule bit in bucket given group and group value
691 * @f: Field containing lookup table
692 * @rule: Rule index
693 * @group: Group index
694 * @v: Value of bit group
695 */
696static void pipapo_bucket_set(struct nft_pipapo_field *f, int rule, int group,
697 int v)
698{
699 unsigned long *pos;
700
bf3e5839
SB
701 pos = NFT_PIPAPO_LT_ALIGN(f->lt);
702 pos += f->bsize * NFT_PIPAPO_BUCKETS(f->bb) * group;
3c4287f6
SB
703 pos += f->bsize * v;
704
705 __set_bit(rule, pos);
706}
707
4051f431
SB
708/**
709 * pipapo_lt_4b_to_8b() - Switch lookup table group width from 4 bits to 8 bits
710 * @old_groups: Number of current groups
711 * @bsize: Size of one bucket, in longs
712 * @old_lt: Pointer to the current lookup table
713 * @new_lt: Pointer to the new, pre-allocated lookup table
714 *
715 * Each bucket with index b in the new lookup table, belonging to group g, is
716 * filled with the bit intersection between:
717 * - bucket with index given by the upper 4 bits of b, from group g, and
718 * - bucket with index given by the lower 4 bits of b, from group g + 1
719 *
720 * That is, given buckets from the new lookup table N(x, y) and the old lookup
721 * table O(x, y), with x bucket index, and y group index:
722 *
723 * N(b, g) := O(b / 16, g) & O(b % 16, g + 1)
724 *
725 * This ensures equivalence of the matching results on lookup. Two examples in
726 * pictures:
727 *
728 * bucket
729 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ... 254 255
730 * 0 ^
731 * 1 | ^
732 * ... ( & ) |
733 * / \ |
734 * / \ .-( & )-.
735 * / bucket \ | |
736 * group 0 / 1 2 3 \ 4 5 6 7 8 9 10 11 12 13 |14 15 |
737 * 0 / \ | |
738 * 1 \ | |
739 * 2 | --'
740 * 3 '-
741 * ...
742 */
743static void pipapo_lt_4b_to_8b(int old_groups, int bsize,
744 unsigned long *old_lt, unsigned long *new_lt)
745{
746 int g, b, i;
747
748 for (g = 0; g < old_groups / 2; g++) {
749 int src_g0 = g * 2, src_g1 = g * 2 + 1;
750
751 for (b = 0; b < NFT_PIPAPO_BUCKETS(8); b++) {
752 int src_b0 = b / NFT_PIPAPO_BUCKETS(4);
753 int src_b1 = b % NFT_PIPAPO_BUCKETS(4);
754 int src_i0 = src_g0 * NFT_PIPAPO_BUCKETS(4) + src_b0;
755 int src_i1 = src_g1 * NFT_PIPAPO_BUCKETS(4) + src_b1;
756
757 for (i = 0; i < bsize; i++) {
758 *new_lt = old_lt[src_i0 * bsize + i] &
759 old_lt[src_i1 * bsize + i];
760 new_lt++;
761 }
762 }
763 }
764}
765
766/**
767 * pipapo_lt_8b_to_4b() - Switch lookup table group width from 8 bits to 4 bits
768 * @old_groups: Number of current groups
769 * @bsize: Size of one bucket, in longs
770 * @old_lt: Pointer to the current lookup table
771 * @new_lt: Pointer to the new, pre-allocated lookup table
772 *
773 * Each bucket with index b in the new lookup table, belonging to group g, is
774 * filled with the bit union of:
775 * - all the buckets with index such that the upper four bits of the lower byte
776 * equal b, from group g, with g odd
777 * - all the buckets with index such that the lower four bits equal b, from
778 * group g, with g even
779 *
780 * That is, given buckets from the new lookup table N(x, y) and the old lookup
781 * table O(x, y), with x bucket index, and y group index:
782 *
783 * - with g odd: N(b, g) := U(O(x, g) for each x : x = (b & 0xf0) >> 4)
784 * - with g even: N(b, g) := U(O(x, g) for each x : x = b & 0x0f)
785 *
786 * where U() denotes the arbitrary union operation (binary OR of n terms). This
787 * ensures equivalence of the matching results on lookup.
788 */
789static void pipapo_lt_8b_to_4b(int old_groups, int bsize,
790 unsigned long *old_lt, unsigned long *new_lt)
791{
792 int g, b, bsrc, i;
793
794 memset(new_lt, 0, old_groups * 2 * NFT_PIPAPO_BUCKETS(4) * bsize *
795 sizeof(unsigned long));
796
797 for (g = 0; g < old_groups * 2; g += 2) {
798 int src_g = g / 2;
799
800 for (b = 0; b < NFT_PIPAPO_BUCKETS(4); b++) {
801 for (bsrc = NFT_PIPAPO_BUCKETS(8) * src_g;
802 bsrc < NFT_PIPAPO_BUCKETS(8) * (src_g + 1);
803 bsrc++) {
804 if (((bsrc & 0xf0) >> 4) != b)
805 continue;
806
807 for (i = 0; i < bsize; i++)
808 new_lt[i] |= old_lt[bsrc * bsize + i];
809 }
810
811 new_lt += bsize;
812 }
813
814 for (b = 0; b < NFT_PIPAPO_BUCKETS(4); b++) {
815 for (bsrc = NFT_PIPAPO_BUCKETS(8) * src_g;
816 bsrc < NFT_PIPAPO_BUCKETS(8) * (src_g + 1);
817 bsrc++) {
818 if ((bsrc & 0x0f) != b)
819 continue;
820
821 for (i = 0; i < bsize; i++)
822 new_lt[i] |= old_lt[bsrc * bsize + i];
823 }
824
825 new_lt += bsize;
826 }
827 }
828}
829
830/**
831 * pipapo_lt_bits_adjust() - Adjust group size for lookup table if needed
832 * @f: Field containing lookup table
833 */
834static void pipapo_lt_bits_adjust(struct nft_pipapo_field *f)
835{
836 unsigned long *new_lt;
837 int groups, bb;
838 size_t lt_size;
839
840 lt_size = f->groups * NFT_PIPAPO_BUCKETS(f->bb) * f->bsize *
841 sizeof(*f->lt);
842
843 if (f->bb == NFT_PIPAPO_GROUP_BITS_SMALL_SET &&
844 lt_size > NFT_PIPAPO_LT_SIZE_HIGH) {
845 groups = f->groups * 2;
846 bb = NFT_PIPAPO_GROUP_BITS_LARGE_SET;
847
848 lt_size = groups * NFT_PIPAPO_BUCKETS(bb) * f->bsize *
849 sizeof(*f->lt);
850 } else if (f->bb == NFT_PIPAPO_GROUP_BITS_LARGE_SET &&
851 lt_size < NFT_PIPAPO_LT_SIZE_LOW) {
852 groups = f->groups / 2;
853 bb = NFT_PIPAPO_GROUP_BITS_SMALL_SET;
854
855 lt_size = groups * NFT_PIPAPO_BUCKETS(bb) * f->bsize *
856 sizeof(*f->lt);
857
858 /* Don't increase group width if the resulting lookup table size
859 * would exceed the upper size threshold for a "small" set.
860 */
861 if (lt_size > NFT_PIPAPO_LT_SIZE_HIGH)
862 return;
863 } else {
864 return;
865 }
866
bf3e5839 867 new_lt = kvzalloc(lt_size + NFT_PIPAPO_ALIGN_HEADROOM, GFP_KERNEL);
4051f431
SB
868 if (!new_lt)
869 return;
870
871 NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4;
bf3e5839
SB
872 if (f->bb == 4 && bb == 8) {
873 pipapo_lt_4b_to_8b(f->groups, f->bsize,
874 NFT_PIPAPO_LT_ALIGN(f->lt),
875 NFT_PIPAPO_LT_ALIGN(new_lt));
876 } else if (f->bb == 8 && bb == 4) {
877 pipapo_lt_8b_to_4b(f->groups, f->bsize,
878 NFT_PIPAPO_LT_ALIGN(f->lt),
879 NFT_PIPAPO_LT_ALIGN(new_lt));
880 } else {
4051f431 881 BUG();
bf3e5839 882 }
4051f431
SB
883
884 f->groups = groups;
885 f->bb = bb;
886 kvfree(f->lt);
bf3e5839 887 NFT_PIPAPO_LT_ASSIGN(f, new_lt);
4051f431
SB
888}
889
3c4287f6
SB
890/**
891 * pipapo_insert() - Insert new rule in field given input key and mask length
892 * @f: Field containing lookup table
893 * @k: Input key for classification, without nftables padding
894 * @mask_bits: Length of mask; matches field length for non-ranged entry
895 *
896 * Insert a new rule reference in lookup buckets corresponding to k and
897 * mask_bits.
898 *
899 * Return: 1 on success (one rule inserted), negative error code on failure.
900 */
901static int pipapo_insert(struct nft_pipapo_field *f, const uint8_t *k,
902 int mask_bits)
903{
e807b13c 904 int rule = f->rules++, group, ret, bit_offset = 0;
3c4287f6
SB
905
906 ret = pipapo_resize(f, f->rules - 1, f->rules);
907 if (ret)
908 return ret;
909
910 for (group = 0; group < f->groups; group++) {
911 int i, v;
912 u8 mask;
913
e807b13c
SB
914 v = k[group / (BITS_PER_BYTE / f->bb)];
915 v &= GENMASK(BITS_PER_BYTE - bit_offset - 1, 0);
916 v >>= (BITS_PER_BYTE - bit_offset) - f->bb;
3c4287f6 917
e807b13c
SB
918 bit_offset += f->bb;
919 bit_offset %= BITS_PER_BYTE;
920
921 if (mask_bits >= (group + 1) * f->bb) {
3c4287f6
SB
922 /* Not masked */
923 pipapo_bucket_set(f, rule, group, v);
e807b13c 924 } else if (mask_bits <= group * f->bb) {
3c4287f6 925 /* Completely masked */
e807b13c 926 for (i = 0; i < NFT_PIPAPO_BUCKETS(f->bb); i++)
3c4287f6
SB
927 pipapo_bucket_set(f, rule, group, i);
928 } else {
929 /* The mask limit falls on this group */
e807b13c
SB
930 mask = GENMASK(f->bb - 1, 0);
931 mask >>= mask_bits - group * f->bb;
932 for (i = 0; i < NFT_PIPAPO_BUCKETS(f->bb); i++) {
3c4287f6
SB
933 if ((i & ~mask) == (v & ~mask))
934 pipapo_bucket_set(f, rule, group, i);
935 }
936 }
937 }
938
4051f431
SB
939 pipapo_lt_bits_adjust(f);
940
3c4287f6
SB
941 return 1;
942}
943
944/**
945 * pipapo_step_diff() - Check if setting @step bit in netmask would change it
946 * @base: Mask we are expanding
947 * @step: Step bit for given expansion step
948 * @len: Total length of mask space (set and unset bits), bytes
949 *
950 * Convenience function for mask expansion.
951 *
952 * Return: true if step bit changes mask (i.e. isn't set), false otherwise.
953 */
954static bool pipapo_step_diff(u8 *base, int step, int len)
955{
956 /* Network order, byte-addressed */
957#ifdef __BIG_ENDIAN__
958 return !(BIT(step % BITS_PER_BYTE) & base[step / BITS_PER_BYTE]);
959#else
960 return !(BIT(step % BITS_PER_BYTE) &
961 base[len - 1 - step / BITS_PER_BYTE]);
962#endif
963}
964
965/**
966 * pipapo_step_after_end() - Check if mask exceeds range end with given step
967 * @base: Mask we are expanding
968 * @end: End of range
969 * @step: Step bit for given expansion step, highest bit to be set
970 * @len: Total length of mask space (set and unset bits), bytes
971 *
972 * Convenience function for mask expansion.
973 *
974 * Return: true if mask exceeds range setting step bits, false otherwise.
975 */
976static bool pipapo_step_after_end(const u8 *base, const u8 *end, int step,
977 int len)
978{
979 u8 tmp[NFT_PIPAPO_MAX_BYTES];
980 int i;
981
982 memcpy(tmp, base, len);
983
984 /* Network order, byte-addressed */
985 for (i = 0; i <= step; i++)
986#ifdef __BIG_ENDIAN__
987 tmp[i / BITS_PER_BYTE] |= BIT(i % BITS_PER_BYTE);
988#else
989 tmp[len - 1 - i / BITS_PER_BYTE] |= BIT(i % BITS_PER_BYTE);
990#endif
991
992 return memcmp(tmp, end, len) > 0;
993}
994
995/**
996 * pipapo_base_sum() - Sum step bit to given len-sized netmask base with carry
997 * @base: Netmask base
998 * @step: Step bit to sum
999 * @len: Netmask length, bytes
1000 */
1001static void pipapo_base_sum(u8 *base, int step, int len)
1002{
1003 bool carry = false;
1004 int i;
1005
1006 /* Network order, byte-addressed */
1007#ifdef __BIG_ENDIAN__
1008 for (i = step / BITS_PER_BYTE; i < len; i++) {
1009#else
1010 for (i = len - 1 - step / BITS_PER_BYTE; i >= 0; i--) {
1011#endif
1012 if (carry)
1013 base[i]++;
1014 else
1015 base[i] += 1 << (step % BITS_PER_BYTE);
1016
1017 if (base[i])
1018 break;
1019
1020 carry = true;
1021 }
1022}
1023
1024/**
1025 * pipapo_expand() - Expand to composing netmasks, insert into lookup table
1026 * @f: Field containing lookup table
1027 * @start: Start of range
1028 * @end: End of range
1029 * @len: Length of value in bits
1030 *
1031 * Expand range to composing netmasks and insert corresponding rule references
1032 * in lookup buckets.
1033 *
1034 * Return: number of inserted rules on success, negative error code on failure.
1035 */
1036static int pipapo_expand(struct nft_pipapo_field *f,
1037 const u8 *start, const u8 *end, int len)
1038{
1039 int step, masks = 0, bytes = DIV_ROUND_UP(len, BITS_PER_BYTE);
1040 u8 base[NFT_PIPAPO_MAX_BYTES];
1041
1042 memcpy(base, start, bytes);
1043 while (memcmp(base, end, bytes) <= 0) {
1044 int err;
1045
1046 step = 0;
1047 while (pipapo_step_diff(base, step, bytes)) {
1048 if (pipapo_step_after_end(base, end, step, bytes))
1049 break;
1050
1051 step++;
1052 if (step >= len) {
1053 if (!masks) {
1054 pipapo_insert(f, base, 0);
1055 masks = 1;
1056 }
1057 goto out;
1058 }
1059 }
1060
1061 err = pipapo_insert(f, base, len - step);
1062
1063 if (err < 0)
1064 return err;
1065
1066 masks++;
1067 pipapo_base_sum(base, step, bytes);
1068 }
1069out:
1070 return masks;
1071}
1072
1073/**
1074 * pipapo_map() - Insert rules in mapping tables, mapping them between fields
1075 * @m: Matching data, including mapping table
1076 * @map: Table of rule maps: array of first rule and amount of rules
1077 * in next field a given rule maps to, for each field
3db86c39 1078 * @e: For last field, nft_set_ext pointer matching rules map to
3c4287f6
SB
1079 */
1080static void pipapo_map(struct nft_pipapo_match *m,
1081 union nft_pipapo_map_bucket map[NFT_PIPAPO_MAX_FIELDS],
1082 struct nft_pipapo_elem *e)
1083{
1084 struct nft_pipapo_field *f;
1085 int i, j;
1086
1087 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++) {
1088 for (j = 0; j < map[i].n; j++) {
1089 f->mt[map[i].to + j].to = map[i + 1].to;
1090 f->mt[map[i].to + j].n = map[i + 1].n;
1091 }
1092 }
1093
1094 /* Last field: map to ext instead of mapping to next field */
1095 for (j = 0; j < map[i].n; j++)
1096 f->mt[map[i].to + j].e = e;
1097}
1098
1099/**
1100 * pipapo_realloc_scratch() - Reallocate scratch maps for partial match results
1101 * @clone: Copy of matching data with pending insertions and deletions
3db86c39 1102 * @bsize_max: Maximum bucket size, scratch maps cover two buckets
3c4287f6
SB
1103 *
1104 * Return: 0 on success, -ENOMEM on failure.
1105 */
1106static int pipapo_realloc_scratch(struct nft_pipapo_match *clone,
1107 unsigned long bsize_max)
1108{
1109 int i;
1110
1111 for_each_possible_cpu(i) {
1112 unsigned long *scratch;
bf3e5839
SB
1113#ifdef NFT_PIPAPO_ALIGN
1114 unsigned long *scratch_aligned;
1115#endif
3c4287f6 1116
bf3e5839
SB
1117 scratch = kzalloc_node(bsize_max * sizeof(*scratch) * 2 +
1118 NFT_PIPAPO_ALIGN_HEADROOM,
3c4287f6
SB
1119 GFP_KERNEL, cpu_to_node(i));
1120 if (!scratch) {
1121 /* On failure, there's no need to undo previous
1122 * allocations: this means that some scratch maps have
1123 * a bigger allocated size now (this is only called on
1124 * insertion), but the extra space won't be used by any
1125 * CPU as new elements are not inserted and m->bsize_max
1126 * is not updated.
1127 */
1128 return -ENOMEM;
1129 }
1130
1131 kfree(*per_cpu_ptr(clone->scratch, i));
1132
1133 *per_cpu_ptr(clone->scratch, i) = scratch;
bf3e5839
SB
1134
1135#ifdef NFT_PIPAPO_ALIGN
1136 scratch_aligned = NFT_PIPAPO_LT_ALIGN(scratch);
1137 *per_cpu_ptr(clone->scratch_aligned, i) = scratch_aligned;
1138#endif
3c4287f6
SB
1139 }
1140
1141 return 0;
1142}
1143
1144/**
1145 * nft_pipapo_insert() - Validate and insert ranged elements
1146 * @net: Network namespace
1147 * @set: nftables API set representation
1148 * @elem: nftables API element representation containing key data
1149 * @ext2: Filled with pointer to &struct nft_set_ext in inserted element
1150 *
1151 * Return: 0 on success, error pointer on failure.
1152 */
1153static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
1154 const struct nft_set_elem *elem,
1155 struct nft_set_ext **ext2)
1156{
1157 const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
1158 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS];
1159 const u8 *start = (const u8 *)elem->key.val.data, *end;
1160 struct nft_pipapo_elem *e = elem->priv, *dup;
1161 struct nft_pipapo *priv = nft_set_priv(set);
1162 struct nft_pipapo_match *m = priv->clone;
1163 u8 genmask = nft_genmask_next(net);
1164 struct nft_pipapo_field *f;
1165 int i, bsize_max, err = 0;
1166
0eb4b5ee
SB
1167 if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END))
1168 end = (const u8 *)nft_set_ext_key_end(ext)->data;
1169 else
1170 end = start;
1171
3c4287f6 1172 dup = pipapo_get(net, set, start, genmask);
0eb4b5ee
SB
1173 if (!IS_ERR(dup)) {
1174 /* Check if we already have the same exact entry */
1175 const struct nft_data *dup_key, *dup_end;
1176
1177 dup_key = nft_set_ext_key(&dup->ext);
1178 if (nft_set_ext_exists(&dup->ext, NFT_SET_EXT_KEY_END))
1179 dup_end = nft_set_ext_key_end(&dup->ext);
1180 else
1181 dup_end = dup_key;
1182
1183 if (!memcmp(start, dup_key->data, sizeof(*dup_key->data)) &&
1184 !memcmp(end, dup_end->data, sizeof(*dup_end->data))) {
1185 *ext2 = &dup->ext;
1186 return -EEXIST;
3c4287f6 1187 }
0eb4b5ee
SB
1188
1189 return -ENOTEMPTY;
1190 }
1191
1192 if (PTR_ERR(dup) == -ENOENT) {
1193 /* Look for partially overlapping entries */
1194 dup = pipapo_get(net, set, end, nft_genmask_next(net));
3c4287f6
SB
1195 }
1196
1197 if (PTR_ERR(dup) != -ENOENT) {
1198 if (IS_ERR(dup))
1199 return PTR_ERR(dup);
1200 *ext2 = &dup->ext;
0eb4b5ee 1201 return -ENOTEMPTY;
3c4287f6
SB
1202 }
1203
1204 /* Validate */
1205 nft_pipapo_for_each_field(f, i, m) {
1206 const u8 *start_p = start, *end_p = end;
1207
1208 if (f->rules >= (unsigned long)NFT_PIPAPO_RULE0_MAX)
1209 return -ENOSPC;
1210
1211 if (memcmp(start_p, end_p,
e807b13c 1212 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)) > 0)
3c4287f6
SB
1213 return -EINVAL;
1214
e807b13c
SB
1215 start_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
1216 end_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
3c4287f6
SB
1217 }
1218
1219 /* Insert */
1220 priv->dirty = true;
1221
1222 bsize_max = m->bsize_max;
1223
1224 nft_pipapo_for_each_field(f, i, m) {
1225 int ret;
1226
1227 rulemap[i].to = f->rules;
1228
1229 ret = memcmp(start, end,
e807b13c
SB
1230 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f));
1231 if (!ret)
1232 ret = pipapo_insert(f, start, f->groups * f->bb);
1233 else
1234 ret = pipapo_expand(f, start, end, f->groups * f->bb);
3c4287f6
SB
1235
1236 if (f->bsize > bsize_max)
1237 bsize_max = f->bsize;
1238
1239 rulemap[i].n = ret;
1240
e807b13c
SB
1241 start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
1242 end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
3c4287f6
SB
1243 }
1244
c3829285
SB
1245 if (!*get_cpu_ptr(m->scratch) || bsize_max > m->bsize_max) {
1246 put_cpu_ptr(m->scratch);
1247
3c4287f6
SB
1248 err = pipapo_realloc_scratch(m, bsize_max);
1249 if (err)
1250 return err;
1251
3c4287f6 1252 m->bsize_max = bsize_max;
c3829285
SB
1253 } else {
1254 put_cpu_ptr(m->scratch);
3c4287f6
SB
1255 }
1256
1257 *ext2 = &e->ext;
1258
1259 pipapo_map(m, rulemap, e);
1260
1261 return 0;
1262}
1263
1264/**
1265 * pipapo_clone() - Clone matching data to create new working copy
1266 * @old: Existing matching data
1267 *
1268 * Return: copy of matching data passed as 'old', error pointer on failure
1269 */
1270static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old)
1271{
1272 struct nft_pipapo_field *dst, *src;
1273 struct nft_pipapo_match *new;
1274 int i;
1275
1276 new = kmalloc(sizeof(*new) + sizeof(*dst) * old->field_count,
1277 GFP_KERNEL);
1278 if (!new)
1279 return ERR_PTR(-ENOMEM);
1280
1281 new->field_count = old->field_count;
1282 new->bsize_max = old->bsize_max;
1283
1284 new->scratch = alloc_percpu(*new->scratch);
1285 if (!new->scratch)
1286 goto out_scratch;
1287
bf3e5839
SB
1288#ifdef NFT_PIPAPO_ALIGN
1289 new->scratch_aligned = alloc_percpu(*new->scratch_aligned);
1290 if (!new->scratch_aligned)
1291 goto out_scratch;
1292#endif
1293
3c4287f6
SB
1294 rcu_head_init(&new->rcu);
1295
1296 src = old->f;
1297 dst = new->f;
1298
1299 for (i = 0; i < old->field_count; i++) {
bf3e5839
SB
1300 unsigned long *new_lt;
1301
3c4287f6
SB
1302 memcpy(dst, src, offsetof(struct nft_pipapo_field, lt));
1303
bf3e5839
SB
1304 new_lt = kvzalloc(src->groups * NFT_PIPAPO_BUCKETS(src->bb) *
1305 src->bsize * sizeof(*dst->lt) +
1306 NFT_PIPAPO_ALIGN_HEADROOM,
1307 GFP_KERNEL);
1308 if (!new_lt)
3c4287f6
SB
1309 goto out_lt;
1310
bf3e5839
SB
1311 NFT_PIPAPO_LT_ASSIGN(dst, new_lt);
1312
1313 memcpy(NFT_PIPAPO_LT_ALIGN(new_lt),
1314 NFT_PIPAPO_LT_ALIGN(src->lt),
3c4287f6 1315 src->bsize * sizeof(*dst->lt) *
e807b13c 1316 src->groups * NFT_PIPAPO_BUCKETS(src->bb));
3c4287f6
SB
1317
1318 dst->mt = kvmalloc(src->rules * sizeof(*src->mt), GFP_KERNEL);
1319 if (!dst->mt)
1320 goto out_mt;
1321
1322 memcpy(dst->mt, src->mt, src->rules * sizeof(*src->mt));
1323 src++;
1324 dst++;
1325 }
1326
1327 return new;
1328
1329out_mt:
1330 kvfree(dst->lt);
1331out_lt:
1332 for (dst--; i > 0; i--) {
1333 kvfree(dst->mt);
1334 kvfree(dst->lt);
1335 dst--;
1336 }
bf3e5839
SB
1337#ifdef NFT_PIPAPO_ALIGN
1338 free_percpu(new->scratch_aligned);
1339#endif
3c4287f6 1340out_scratch:
bf3e5839 1341 free_percpu(new->scratch);
3c4287f6
SB
1342 kfree(new);
1343
1344 return ERR_PTR(-ENOMEM);
1345}
1346
1347/**
1348 * pipapo_rules_same_key() - Get number of rules originated from the same entry
1349 * @f: Field containing mapping table
1350 * @first: Index of first rule in set of rules mapping to same entry
1351 *
1352 * Using the fact that all rules in a field that originated from the same entry
1353 * will map to the same set of rules in the next field, or to the same element
1354 * reference, return the cardinality of the set of rules that originated from
1355 * the same entry as the rule with index @first, @first rule included.
1356 *
1357 * In pictures:
1358 * rules
1359 * field #0 0 1 2 3 4
1360 * map to: 0 1 2-4 2-4 5-9
1361 * . . ....... . ...
1362 * | | | | \ \
1363 * | | | | \ \
1364 * | | | | \ \
1365 * ' ' ' ' ' \
1366 * in field #1 0 1 2 3 4 5 ...
1367 *
1368 * if this is called for rule 2 on field #0, it will return 3, as also rules 2
1369 * and 3 in field 0 map to the same set of rules (2, 3, 4) in the next field.
1370 *
1371 * For the last field in a set, we can rely on associated entries to map to the
1372 * same element references.
1373 *
1374 * Return: Number of rules that originated from the same entry as @first.
1375 */
1376static int pipapo_rules_same_key(struct nft_pipapo_field *f, int first)
1377{
1378 struct nft_pipapo_elem *e = NULL; /* Keep gcc happy */
1379 int r;
1380
1381 for (r = first; r < f->rules; r++) {
1382 if (r != first && e != f->mt[r].e)
1383 return r - first;
1384
1385 e = f->mt[r].e;
1386 }
1387
1388 if (r != first)
1389 return r - first;
1390
1391 return 0;
1392}
1393
1394/**
1395 * pipapo_unmap() - Remove rules from mapping tables, renumber remaining ones
1396 * @mt: Mapping array
1397 * @rules: Original amount of rules in mapping table
1398 * @start: First rule index to be removed
1399 * @n: Amount of rules to be removed
1400 * @to_offset: First rule index, in next field, this group of rules maps to
1401 * @is_last: If this is the last field, delete reference from mapping array
1402 *
1403 * This is used to unmap rules from the mapping table for a single field,
1404 * maintaining consistency and compactness for the existing ones.
1405 *
1406 * In pictures: let's assume that we want to delete rules 2 and 3 from the
1407 * following mapping array:
1408 *
1409 * rules
1410 * 0 1 2 3 4
1411 * map to: 4-10 4-10 11-15 11-15 16-18
1412 *
1413 * the result will be:
1414 *
1415 * rules
1416 * 0 1 2
1417 * map to: 4-10 4-10 11-13
1418 *
1419 * for fields before the last one. In case this is the mapping table for the
1420 * last field in a set, and rules map to pointers to &struct nft_pipapo_elem:
1421 *
1422 * rules
1423 * 0 1 2 3 4
1424 * element pointers: 0x42 0x42 0x33 0x33 0x44
1425 *
1426 * the result will be:
1427 *
1428 * rules
1429 * 0 1 2
1430 * element pointers: 0x42 0x42 0x44
1431 */
1432static void pipapo_unmap(union nft_pipapo_map_bucket *mt, int rules,
1433 int start, int n, int to_offset, bool is_last)
1434{
1435 int i;
1436
1437 memmove(mt + start, mt + start + n, (rules - start - n) * sizeof(*mt));
1438 memset(mt + rules - n, 0, n * sizeof(*mt));
1439
1440 if (is_last)
1441 return;
1442
1443 for (i = start; i < rules - n; i++)
1444 mt[i].to -= to_offset;
1445}
1446
1447/**
1448 * pipapo_drop() - Delete entry from lookup and mapping tables, given rule map
1449 * @m: Matching data
3db86c39 1450 * @rulemap: Table of rule maps, arrays of first rule and amount of rules
3c4287f6
SB
1451 * in next field a given entry maps to, for each field
1452 *
1453 * For each rule in lookup table buckets mapping to this set of rules, drop
1454 * all bits set in lookup table mapping. In pictures, assuming we want to drop
1455 * rules 0 and 1 from this lookup table:
1456 *
1457 * bucket
1458 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1459 * 0 0 1,2
1460 * 1 1,2 0
1461 * 2 0 1,2
1462 * 3 0 1,2
1463 * 4 0,1,2
1464 * 5 0 1 2
1465 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1466 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1
1467 *
1468 * rule 2 becomes rule 0, and the result will be:
1469 *
1470 * bucket
1471 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1472 * 0 0
1473 * 1 0
1474 * 2 0
1475 * 3 0
1476 * 4 0
1477 * 5 0
1478 * 6 0
1479 * 7 0 0
1480 *
1481 * once this is done, call unmap() to drop all the corresponding rule references
1482 * from mapping tables.
1483 */
1484static void pipapo_drop(struct nft_pipapo_match *m,
1485 union nft_pipapo_map_bucket rulemap[])
1486{
1487 struct nft_pipapo_field *f;
1488 int i;
1489
1490 nft_pipapo_for_each_field(f, i, m) {
1491 int g;
1492
1493 for (g = 0; g < f->groups; g++) {
1494 unsigned long *pos;
1495 int b;
1496
bf3e5839
SB
1497 pos = NFT_PIPAPO_LT_ALIGN(f->lt) + g *
1498 NFT_PIPAPO_BUCKETS(f->bb) * f->bsize;
3c4287f6 1499
e807b13c 1500 for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) {
3c4287f6
SB
1501 bitmap_cut(pos, pos, rulemap[i].to,
1502 rulemap[i].n,
1503 f->bsize * BITS_PER_LONG);
1504
1505 pos += f->bsize;
1506 }
1507 }
1508
1509 pipapo_unmap(f->mt, f->rules, rulemap[i].to, rulemap[i].n,
1510 rulemap[i + 1].n, i == m->field_count - 1);
1511 if (pipapo_resize(f, f->rules, f->rules - rulemap[i].n)) {
1512 /* We can ignore this, a failure to shrink tables down
1513 * doesn't make tables invalid.
1514 */
1515 ;
1516 }
1517 f->rules -= rulemap[i].n;
4051f431
SB
1518
1519 pipapo_lt_bits_adjust(f);
3c4287f6
SB
1520 }
1521}
1522
1523/**
1524 * pipapo_gc() - Drop expired entries from set, destroy start and end elements
1525 * @set: nftables API set representation
1526 * @m: Matching data
1527 */
1528static void pipapo_gc(const struct nft_set *set, struct nft_pipapo_match *m)
1529{
1530 struct nft_pipapo *priv = nft_set_priv(set);
1531 int rules_f0, first_rule = 0;
1532
1533 while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) {
1534 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS];
1535 struct nft_pipapo_field *f;
1536 struct nft_pipapo_elem *e;
1537 int i, start, rules_fx;
1538
1539 start = first_rule;
1540 rules_fx = rules_f0;
1541
1542 nft_pipapo_for_each_field(f, i, m) {
1543 rulemap[i].to = start;
1544 rulemap[i].n = rules_fx;
1545
1546 if (i < m->field_count - 1) {
1547 rules_fx = f->mt[start].n;
1548 start = f->mt[start].to;
1549 }
1550 }
1551
1552 /* Pick the last field, and its last index */
1553 f--;
1554 i--;
1555 e = f->mt[rulemap[i].to].e;
1556 if (nft_set_elem_expired(&e->ext) &&
1557 !nft_set_elem_mark_busy(&e->ext)) {
1558 priv->dirty = true;
1559 pipapo_drop(m, rulemap);
1560
1561 rcu_barrier();
1562 nft_set_elem_destroy(set, e, true);
1563
1564 /* And check again current first rule, which is now the
1565 * first we haven't checked.
1566 */
1567 } else {
1568 first_rule += rules_f0;
1569 }
1570 }
1571
1572 priv->last_gc = jiffies;
1573}
1574
1575/**
1576 * pipapo_free_fields() - Free per-field tables contained in matching data
1577 * @m: Matching data
1578 */
1579static void pipapo_free_fields(struct nft_pipapo_match *m)
1580{
1581 struct nft_pipapo_field *f;
1582 int i;
1583
1584 nft_pipapo_for_each_field(f, i, m) {
1585 kvfree(f->lt);
1586 kvfree(f->mt);
1587 }
1588}
1589
1590/**
1591 * pipapo_reclaim_match - RCU callback to free fields from old matching data
1592 * @rcu: RCU head
1593 */
1594static void pipapo_reclaim_match(struct rcu_head *rcu)
1595{
1596 struct nft_pipapo_match *m;
1597 int i;
1598
1599 m = container_of(rcu, struct nft_pipapo_match, rcu);
1600
1601 for_each_possible_cpu(i)
1602 kfree(*per_cpu_ptr(m->scratch, i));
1603
bf3e5839
SB
1604#ifdef NFT_PIPAPO_ALIGN
1605 free_percpu(m->scratch_aligned);
1606#endif
3c4287f6
SB
1607 free_percpu(m->scratch);
1608
1609 pipapo_free_fields(m);
1610
1611 kfree(m);
1612}
1613
1614/**
1615 * pipapo_commit() - Replace lookup data with current working copy
1616 * @set: nftables API set representation
1617 *
1618 * While at it, check if we should perform garbage collection on the working
1619 * copy before committing it for lookup, and don't replace the table if the
1620 * working copy doesn't have pending changes.
1621 *
1622 * We also need to create a new working copy for subsequent insertions and
1623 * deletions.
1624 */
1625static void pipapo_commit(const struct nft_set *set)
1626{
1627 struct nft_pipapo *priv = nft_set_priv(set);
1628 struct nft_pipapo_match *new_clone, *old;
1629
1630 if (time_after_eq(jiffies, priv->last_gc + nft_set_gc_interval(set)))
1631 pipapo_gc(set, priv->clone);
1632
1633 if (!priv->dirty)
1634 return;
1635
1636 new_clone = pipapo_clone(priv->clone);
1637 if (IS_ERR(new_clone))
1638 return;
1639
1640 priv->dirty = false;
1641
1642 old = rcu_access_pointer(priv->match);
1643 rcu_assign_pointer(priv->match, priv->clone);
1644 if (old)
1645 call_rcu(&old->rcu, pipapo_reclaim_match);
1646
1647 priv->clone = new_clone;
1648}
1649
1650/**
1651 * nft_pipapo_activate() - Mark element reference as active given key, commit
1652 * @net: Network namespace
1653 * @set: nftables API set representation
1654 * @elem: nftables API element representation containing key data
1655 *
1656 * On insertion, elements are added to a copy of the matching data currently
1657 * in use for lookups, and not directly inserted into current lookup data, so
1658 * we'll take care of that by calling pipapo_commit() here. Both
1659 * nft_pipapo_insert() and nft_pipapo_activate() are called once for each
1660 * element, hence we can't purpose either one as a real commit operation.
1661 */
1662static void nft_pipapo_activate(const struct net *net,
1663 const struct nft_set *set,
1664 const struct nft_set_elem *elem)
1665{
1666 struct nft_pipapo_elem *e;
1667
1668 e = pipapo_get(net, set, (const u8 *)elem->key.val.data, 0);
1669 if (IS_ERR(e))
1670 return;
1671
1672 nft_set_elem_change_active(net, set, &e->ext);
1673 nft_set_elem_clear_busy(&e->ext);
1674
1675 pipapo_commit(set);
1676}
1677
1678/**
1679 * pipapo_deactivate() - Check that element is in set, mark as inactive
1680 * @net: Network namespace
1681 * @set: nftables API set representation
1682 * @data: Input key data
1683 * @ext: nftables API extension pointer, used to check for end element
1684 *
1685 * This is a convenience function that can be called from both
1686 * nft_pipapo_deactivate() and nft_pipapo_flush(), as they are in fact the same
1687 * operation.
1688 *
1689 * Return: deactivated element if found, NULL otherwise.
1690 */
1691static void *pipapo_deactivate(const struct net *net, const struct nft_set *set,
1692 const u8 *data, const struct nft_set_ext *ext)
1693{
1694 struct nft_pipapo_elem *e;
1695
1696 e = pipapo_get(net, set, data, nft_genmask_next(net));
1697 if (IS_ERR(e))
1698 return NULL;
1699
1700 nft_set_elem_change_active(net, set, &e->ext);
1701
1702 return e;
1703}
1704
1705/**
1706 * nft_pipapo_deactivate() - Call pipapo_deactivate() to make element inactive
1707 * @net: Network namespace
1708 * @set: nftables API set representation
1709 * @elem: nftables API element representation containing key data
1710 *
1711 * Return: deactivated element if found, NULL otherwise.
1712 */
1713static void *nft_pipapo_deactivate(const struct net *net,
1714 const struct nft_set *set,
1715 const struct nft_set_elem *elem)
1716{
1717 const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
1718
1719 return pipapo_deactivate(net, set, (const u8 *)elem->key.val.data, ext);
1720}
1721
1722/**
1723 * nft_pipapo_flush() - Call pipapo_deactivate() to make element inactive
1724 * @net: Network namespace
1725 * @set: nftables API set representation
1726 * @elem: nftables API element representation containing key data
1727 *
1728 * This is functionally the same as nft_pipapo_deactivate(), with a slightly
1729 * different interface, and it's also called once for each element in a set
1730 * being flushed, so we can't implement, strictly speaking, a flush operation,
1731 * which would otherwise be as simple as allocating an empty copy of the
1732 * matching data.
1733 *
1734 * Note that we could in theory do that, mark the set as flushed, and ignore
1735 * subsequent calls, but we would leak all the elements after the first one,
1736 * because they wouldn't then be freed as result of API calls.
1737 *
1738 * Return: true if element was found and deactivated.
1739 */
1740static bool nft_pipapo_flush(const struct net *net, const struct nft_set *set,
1741 void *elem)
1742{
1743 struct nft_pipapo_elem *e = elem;
1744
1745 return pipapo_deactivate(net, set, (const u8 *)nft_set_ext_key(&e->ext),
1746 &e->ext);
1747}
1748
1749/**
1750 * pipapo_get_boundaries() - Get byte interval for associated rules
1751 * @f: Field including lookup table
1752 * @first_rule: First rule (lowest index)
1753 * @rule_count: Number of associated rules
1754 * @left: Byte expression for left boundary (start of range)
1755 * @right: Byte expression for right boundary (end of range)
1756 *
1757 * Given the first rule and amount of rules that originated from the same entry,
1758 * build the original range associated with the entry, and calculate the length
1759 * of the originating netmask.
1760 *
1761 * In pictures:
1762 *
1763 * bucket
1764 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1765 * 0 1,2
1766 * 1 1,2
1767 * 2 1,2
1768 * 3 1,2
1769 * 4 1,2
1770 * 5 1 2
1771 * 6 1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1772 * 7 1,2 1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1773 *
1774 * this is the lookup table corresponding to the IPv4 range
1775 * 192.168.1.0-192.168.2.1, which was expanded to the two composing netmasks,
1776 * rule #1: 192.168.1.0/24, and rule #2: 192.168.2.0/31.
1777 *
1778 * This function fills @left and @right with the byte values of the leftmost
1779 * and rightmost bucket indices for the lowest and highest rule indices,
1780 * respectively. If @first_rule is 1 and @rule_count is 2, we obtain, in
1781 * nibbles:
1782 * left: < 12, 0, 10, 8, 0, 1, 0, 0 >
1783 * right: < 12, 0, 10, 8, 0, 2, 2, 1 >
1784 * corresponding to bytes:
1785 * left: < 192, 168, 1, 0 >
1786 * right: < 192, 168, 2, 1 >
1787 * with mask length irrelevant here, unused on return, as the range is already
1788 * defined by its start and end points. The mask length is relevant for a single
1789 * ranged entry instead: if @first_rule is 1 and @rule_count is 1, we ignore
1790 * rule 2 above: @left becomes < 192, 168, 1, 0 >, @right becomes
1791 * < 192, 168, 1, 255 >, and the mask length, calculated from the distances
1792 * between leftmost and rightmost bucket indices for each group, would be 24.
1793 *
1794 * Return: mask length, in bits.
1795 */
1796static int pipapo_get_boundaries(struct nft_pipapo_field *f, int first_rule,
1797 int rule_count, u8 *left, u8 *right)
1798{
e807b13c 1799 int g, mask_len = 0, bit_offset = 0;
3c4287f6 1800 u8 *l = left, *r = right;
3c4287f6
SB
1801
1802 for (g = 0; g < f->groups; g++) {
1803 int b, x0, x1;
1804
1805 x0 = -1;
1806 x1 = -1;
e807b13c 1807 for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) {
3c4287f6
SB
1808 unsigned long *pos;
1809
bf3e5839
SB
1810 pos = NFT_PIPAPO_LT_ALIGN(f->lt) +
1811 (g * NFT_PIPAPO_BUCKETS(f->bb) + b) * f->bsize;
3c4287f6
SB
1812 if (test_bit(first_rule, pos) && x0 == -1)
1813 x0 = b;
1814 if (test_bit(first_rule + rule_count - 1, pos))
1815 x1 = b;
1816 }
1817
e807b13c
SB
1818 *l |= x0 << (BITS_PER_BYTE - f->bb - bit_offset);
1819 *r |= x1 << (BITS_PER_BYTE - f->bb - bit_offset);
1820
1821 bit_offset += f->bb;
1822 if (bit_offset >= BITS_PER_BYTE) {
1823 bit_offset %= BITS_PER_BYTE;
1824 l++;
1825 r++;
3c4287f6
SB
1826 }
1827
1828 if (x1 - x0 == 0)
1829 mask_len += 4;
1830 else if (x1 - x0 == 1)
1831 mask_len += 3;
1832 else if (x1 - x0 == 3)
1833 mask_len += 2;
1834 else if (x1 - x0 == 7)
1835 mask_len += 1;
1836 }
1837
1838 return mask_len;
1839}
1840
1841/**
1842 * pipapo_match_field() - Match rules against byte ranges
1843 * @f: Field including the lookup table
1844 * @first_rule: First of associated rules originating from same entry
1845 * @rule_count: Amount of associated rules
1846 * @start: Start of range to be matched
1847 * @end: End of range to be matched
1848 *
1849 * Return: true on match, false otherwise.
1850 */
1851static bool pipapo_match_field(struct nft_pipapo_field *f,
1852 int first_rule, int rule_count,
1853 const u8 *start, const u8 *end)
1854{
1855 u8 right[NFT_PIPAPO_MAX_BYTES] = { 0 };
1856 u8 left[NFT_PIPAPO_MAX_BYTES] = { 0 };
1857
1858 pipapo_get_boundaries(f, first_rule, rule_count, left, right);
1859
e807b13c
SB
1860 return !memcmp(start, left,
1861 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)) &&
1862 !memcmp(end, right, f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f));
3c4287f6
SB
1863}
1864
1865/**
1866 * nft_pipapo_remove() - Remove element given key, commit
1867 * @net: Network namespace
1868 * @set: nftables API set representation
1869 * @elem: nftables API element representation containing key data
1870 *
1871 * Similarly to nft_pipapo_activate(), this is used as commit operation by the
1872 * API, but it's called once per element in the pending transaction, so we can't
1873 * implement this as a single commit operation. Closest we can get is to remove
1874 * the matched element here, if any, and commit the updated matching data.
1875 */
1876static void nft_pipapo_remove(const struct net *net, const struct nft_set *set,
1877 const struct nft_set_elem *elem)
1878{
3c4287f6
SB
1879 struct nft_pipapo *priv = nft_set_priv(set);
1880 struct nft_pipapo_match *m = priv->clone;
212d58c1 1881 struct nft_pipapo_elem *e = elem->priv;
3c4287f6 1882 int rules_f0, first_rule = 0;
212d58c1
SB
1883 const u8 *data;
1884
1885 data = (const u8 *)nft_set_ext_key(&e->ext);
3c4287f6
SB
1886
1887 e = pipapo_get(net, set, data, 0);
1888 if (IS_ERR(e))
1889 return;
1890
1891 while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) {
1892 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS];
1893 const u8 *match_start, *match_end;
1894 struct nft_pipapo_field *f;
1895 int i, start, rules_fx;
1896
1897 match_start = data;
1898 match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data;
1899
1900 start = first_rule;
1901 rules_fx = rules_f0;
1902
1903 nft_pipapo_for_each_field(f, i, m) {
1904 if (!pipapo_match_field(f, start, rules_fx,
1905 match_start, match_end))
1906 break;
1907
1908 rulemap[i].to = start;
1909 rulemap[i].n = rules_fx;
1910
1911 rules_fx = f->mt[start].n;
1912 start = f->mt[start].to;
1913
e807b13c
SB
1914 match_start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
1915 match_end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
3c4287f6
SB
1916 }
1917
1918 if (i == m->field_count) {
1919 priv->dirty = true;
1920 pipapo_drop(m, rulemap);
1921 pipapo_commit(set);
1922 return;
1923 }
1924
1925 first_rule += rules_f0;
1926 }
1927}
1928
1929/**
1930 * nft_pipapo_walk() - Walk over elements
1931 * @ctx: nftables API context
1932 * @set: nftables API set representation
1933 * @iter: Iterator
1934 *
1935 * As elements are referenced in the mapping array for the last field, directly
1936 * scan that array: there's no need to follow rule mappings from the first
1937 * field.
1938 */
1939static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set,
1940 struct nft_set_iter *iter)
1941{
1942 struct nft_pipapo *priv = nft_set_priv(set);
1943 struct nft_pipapo_match *m;
1944 struct nft_pipapo_field *f;
1945 int i, r;
1946
1947 rcu_read_lock();
1948 m = rcu_dereference(priv->match);
1949
1950 if (unlikely(!m))
1951 goto out;
1952
1953 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++)
1954 ;
1955
1956 for (r = 0; r < f->rules; r++) {
1957 struct nft_pipapo_elem *e;
1958 struct nft_set_elem elem;
1959
1960 if (r < f->rules - 1 && f->mt[r + 1].e == f->mt[r].e)
1961 continue;
1962
1963 if (iter->count < iter->skip)
1964 goto cont;
1965
1966 e = f->mt[r].e;
1967 if (nft_set_elem_expired(&e->ext))
1968 goto cont;
1969
1970 elem.priv = e;
1971
1972 iter->err = iter->fn(ctx, set, iter, &elem);
1973 if (iter->err < 0)
1974 goto out;
1975
1976cont:
1977 iter->count++;
1978 }
1979
1980out:
1981 rcu_read_unlock();
1982}
1983
1984/**
1985 * nft_pipapo_privsize() - Return the size of private data for the set
1986 * @nla: netlink attributes, ignored as size doesn't depend on them
1987 * @desc: Set description, ignored as size doesn't depend on it
1988 *
1989 * Return: size of private data for this set implementation, in bytes
1990 */
1991static u64 nft_pipapo_privsize(const struct nlattr * const nla[],
1992 const struct nft_set_desc *desc)
1993{
1994 return sizeof(struct nft_pipapo);
1995}
1996
1997/**
8683f4b9
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1998 * nft_pipapo_estimate() - Set size, space and lookup complexity
1999 * @desc: Set description, element count and field description used
3c4287f6
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2000 * @features: Flags: NFT_SET_INTERVAL needs to be there
2001 * @est: Storage for estimation data
2002 *
8683f4b9 2003 * Return: true if set description is compatible, false otherwise
3c4287f6
SB
2004 */
2005static bool nft_pipapo_estimate(const struct nft_set_desc *desc, u32 features,
2006 struct nft_set_estimate *est)
2007{
eb16933a
SB
2008 if (!(features & NFT_SET_INTERVAL) ||
2009 desc->field_count < NFT_PIPAPO_MIN_FIELDS)
3c4287f6
SB
2010 return false;
2011
8683f4b9
SB
2012 est->size = pipapo_estimate_size(desc);
2013 if (!est->size)
3c4287f6
SB
2014 return false;
2015
3c4287f6
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2016 est->lookup = NFT_SET_CLASS_O_LOG_N;
2017
2018 est->space = NFT_SET_CLASS_O_N;
2019
2020 return true;
2021}
2022
2023/**
2024 * nft_pipapo_init() - Initialise data for a set instance
2025 * @set: nftables API set representation
2026 * @desc: Set description
2027 * @nla: netlink attributes
2028 *
2029 * Validate number and size of fields passed as NFTA_SET_DESC_CONCAT netlink
2030 * attributes, initialise internal set parameters, current instance of matching
2031 * data and a copy for subsequent insertions.
2032 *
2033 * Return: 0 on success, negative error code on failure.
2034 */
2035static int nft_pipapo_init(const struct nft_set *set,
2036 const struct nft_set_desc *desc,
2037 const struct nlattr * const nla[])
2038{
2039 struct nft_pipapo *priv = nft_set_priv(set);
2040 struct nft_pipapo_match *m;
2041 struct nft_pipapo_field *f;
eb16933a 2042 int err, i, field_count;
3c4287f6 2043
eb16933a
SB
2044 field_count = desc->field_count ? : 1;
2045
2046 if (field_count > NFT_PIPAPO_MAX_FIELDS)
3c4287f6
SB
2047 return -EINVAL;
2048
eb16933a 2049 m = kmalloc(sizeof(*priv->match) + sizeof(*f) * field_count,
3c4287f6
SB
2050 GFP_KERNEL);
2051 if (!m)
2052 return -ENOMEM;
2053
eb16933a 2054 m->field_count = field_count;
3c4287f6
SB
2055 m->bsize_max = 0;
2056
2057 m->scratch = alloc_percpu(unsigned long *);
2058 if (!m->scratch) {
2059 err = -ENOMEM;
bf3e5839 2060 goto out_scratch;
3c4287f6
SB
2061 }
2062 for_each_possible_cpu(i)
2063 *per_cpu_ptr(m->scratch, i) = NULL;
2064
bf3e5839
SB
2065#ifdef NFT_PIPAPO_ALIGN
2066 m->scratch_aligned = alloc_percpu(unsigned long *);
2067 if (!m->scratch_aligned) {
2068 err = -ENOMEM;
2069 goto out_free;
2070 }
2071 for_each_possible_cpu(i)
2072 *per_cpu_ptr(m->scratch_aligned, i) = NULL;
2073#endif
2074
3c4287f6
SB
2075 rcu_head_init(&m->rcu);
2076
2077 nft_pipapo_for_each_field(f, i, m) {
eb16933a
SB
2078 int len = desc->field_len[i] ? : set->klen;
2079
4051f431 2080 f->bb = NFT_PIPAPO_GROUP_BITS_INIT;
eb16933a 2081 f->groups = len * NFT_PIPAPO_GROUPS_PER_BYTE(f);
3c4287f6 2082
eb16933a 2083 priv->width += round_up(len, sizeof(u32));
3c4287f6
SB
2084
2085 f->bsize = 0;
2086 f->rules = 0;
bf3e5839 2087 NFT_PIPAPO_LT_ASSIGN(f, NULL);
3c4287f6
SB
2088 f->mt = NULL;
2089 }
2090
2091 /* Create an initial clone of matching data for next insertion */
2092 priv->clone = pipapo_clone(m);
2093 if (IS_ERR(priv->clone)) {
2094 err = PTR_ERR(priv->clone);
2095 goto out_free;
2096 }
2097
2098 priv->dirty = false;
2099
2100 rcu_assign_pointer(priv->match, m);
2101
2102 return 0;
2103
2104out_free:
bf3e5839
SB
2105#ifdef NFT_PIPAPO_ALIGN
2106 free_percpu(m->scratch_aligned);
2107#endif
3c4287f6 2108 free_percpu(m->scratch);
bf3e5839 2109out_scratch:
3c4287f6
SB
2110 kfree(m);
2111
2112 return err;
2113}
2114
2115/**
2116 * nft_pipapo_destroy() - Free private data for set and all committed elements
2117 * @set: nftables API set representation
2118 */
2119static void nft_pipapo_destroy(const struct nft_set *set)
2120{
2121 struct nft_pipapo *priv = nft_set_priv(set);
2122 struct nft_pipapo_match *m;
2123 struct nft_pipapo_field *f;
2124 int i, r, cpu;
2125
2126 m = rcu_dereference_protected(priv->match, true);
2127 if (m) {
2128 rcu_barrier();
2129
2130 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++)
2131 ;
2132
2133 for (r = 0; r < f->rules; r++) {
2134 struct nft_pipapo_elem *e;
2135
2136 if (r < f->rules - 1 && f->mt[r + 1].e == f->mt[r].e)
2137 continue;
2138
2139 e = f->mt[r].e;
2140
2141 nft_set_elem_destroy(set, e, true);
2142 }
2143
bf3e5839
SB
2144#ifdef NFT_PIPAPO_ALIGN
2145 free_percpu(m->scratch_aligned);
2146#endif
3c4287f6
SB
2147 for_each_possible_cpu(cpu)
2148 kfree(*per_cpu_ptr(m->scratch, cpu));
2149 free_percpu(m->scratch);
3c4287f6
SB
2150 pipapo_free_fields(m);
2151 kfree(m);
2152 priv->match = NULL;
2153 }
2154
2155 if (priv->clone) {
bf3e5839
SB
2156#ifdef NFT_PIPAPO_ALIGN
2157 free_percpu(priv->clone->scratch_aligned);
2158#endif
3c4287f6
SB
2159 for_each_possible_cpu(cpu)
2160 kfree(*per_cpu_ptr(priv->clone->scratch, cpu));
2161 free_percpu(priv->clone->scratch);
2162
2163 pipapo_free_fields(priv->clone);
2164 kfree(priv->clone);
2165 priv->clone = NULL;
2166 }
2167}
2168
2169/**
2170 * nft_pipapo_gc_init() - Initialise garbage collection
2171 * @set: nftables API set representation
2172 *
2173 * Instead of actually setting up a periodic work for garbage collection, as
2174 * this operation requires a swap of matching data with the working copy, we'll
2175 * do that opportunistically with other commit operations if the interval is
2176 * elapsed, so we just need to set the current jiffies timestamp here.
2177 */
2178static void nft_pipapo_gc_init(const struct nft_set *set)
2179{
2180 struct nft_pipapo *priv = nft_set_priv(set);
2181
2182 priv->last_gc = jiffies;
2183}
2184
24d19826 2185const struct nft_set_type nft_set_pipapo_type = {
3c4287f6
SB
2186 .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT |
2187 NFT_SET_TIMEOUT,
2188 .ops = {
2189 .lookup = nft_pipapo_lookup,
2190 .insert = nft_pipapo_insert,
2191 .activate = nft_pipapo_activate,
2192 .deactivate = nft_pipapo_deactivate,
2193 .flush = nft_pipapo_flush,
2194 .remove = nft_pipapo_remove,
2195 .walk = nft_pipapo_walk,
2196 .get = nft_pipapo_get,
2197 .privsize = nft_pipapo_privsize,
2198 .estimate = nft_pipapo_estimate,
2199 .init = nft_pipapo_init,
2200 .destroy = nft_pipapo_destroy,
2201 .gc_init = nft_pipapo_gc_init,
2202 .elemsize = offsetof(struct nft_pipapo_elem, ext),
2203 },
2204};
7400b063 2205
e6abef61 2206#if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
7400b063
SB
2207const struct nft_set_type nft_set_pipapo_avx2_type = {
2208 .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT |
2209 NFT_SET_TIMEOUT,
2210 .ops = {
2211 .lookup = nft_pipapo_avx2_lookup,
2212 .insert = nft_pipapo_insert,
2213 .activate = nft_pipapo_activate,
2214 .deactivate = nft_pipapo_deactivate,
2215 .flush = nft_pipapo_flush,
2216 .remove = nft_pipapo_remove,
2217 .walk = nft_pipapo_walk,
2218 .get = nft_pipapo_get,
2219 .privsize = nft_pipapo_privsize,
2220 .estimate = nft_pipapo_avx2_estimate,
2221 .init = nft_pipapo_init,
2222 .destroy = nft_pipapo_destroy,
2223 .gc_init = nft_pipapo_gc_init,
2224 .elemsize = offsetof(struct nft_pipapo_elem, ext),
2225 },
2226};
2227#endif