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
206  *       map to elements:             0x66  0x42
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
301  *       map to elements:             0x66  0x42
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.
315  *      https://www.cse.usf.edu/~ligatti/papers/grouper-conf.pdf
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.
328  *      https://www.sigcomm.org/sites/default/files/ccr/papers/2014/August/2619239-2626294.pdf
329  */
330 
331 #include <linux/kernel.h>
332 #include <linux/init.h>
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>
339 #include <linux/bitmap.h>
340 #include <linux/bitops.h>
341 
342 #include "nft_set_pipapo_avx2.h"
343 #include "nft_set_pipapo.h"
344 
345 /* Current working bitmap index, toggled between field matches */
346 static DEFINE_PER_CPU(bool, nft_pipapo_scratch_index);
347 
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  */
365 int pipapo_refill(unsigned long *map, int len, int rules, unsigned long *dst,
366 		  union nft_pipapo_map_bucket *mt, bool match_only)
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 
383 			if (match_only) {
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
404  * @key:	nftables API element representation containing key data
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  */
411 static 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;
439 		int b;
440 
441 		/* For each bit group: select lookup table bucket depending on
442 		 * packet bytes value, then AND bucket value
443 		 */
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;
449 
450 		rp += f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f);
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 		 */
459 next_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 
493 		rp += NFT_PIPAPO_GROUPS_PADDING(f);
494 	}
495 
496 out:
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  */
514 static 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;
541 		int b;
542 
543 		/* For each bit group: select lookup table bucket depending on
544 		 * packet bytes value, then AND bucket value
545 		 */
546 		if (f->bb == 8)
547 			pipapo_and_field_buckets_8bit(f, res_map, data);
548 		else if (f->bb == 4)
549 			pipapo_and_field_buckets_4bit(f, res_map, data);
550 		else
551 			BUG();
552 
553 		data += f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f);
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 		 */
562 next_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 
578 		data += NFT_PIPAPO_GROUPS_PADDING(f);
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 
588 out:
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  */
601 static void *nft_pipapo_get(const struct net *net, const struct nft_set *set,
602 			    const struct nft_set_elem *elem, unsigned int flags)
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  */
620 static 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);
628 #ifdef NFT_PIPAPO_ALIGN
629 	new_bucket_size = roundup(new_bucket_size,
630 				  NFT_PIPAPO_ALIGN / sizeof(*new_lt));
631 #endif
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 
641 	new_lt = kvzalloc(f->groups * NFT_PIPAPO_BUCKETS(f->bb) *
642 			  new_bucket_size * sizeof(*new_lt) +
643 			  NFT_PIPAPO_ALIGN_HEADROOM,
644 			  GFP_KERNEL);
645 	if (!new_lt)
646 		return -ENOMEM;
647 
648 	new_p = NFT_PIPAPO_LT_ALIGN(new_lt);
649 	old_p = NFT_PIPAPO_LT_ALIGN(old_lt);
650 
651 	for (group = 0; group < f->groups; group++) {
652 		for (bucket = 0; bucket < NFT_PIPAPO_BUCKETS(f->bb); bucket++) {
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 
664 mt:
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;
679 		NFT_PIPAPO_LT_ASSIGN(f, new_lt);
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  */
696 static void pipapo_bucket_set(struct nft_pipapo_field *f, int rule, int group,
697 			      int v)
698 {
699 	unsigned long *pos;
700 
701 	pos = NFT_PIPAPO_LT_ALIGN(f->lt);
702 	pos += f->bsize * NFT_PIPAPO_BUCKETS(f->bb) * group;
703 	pos += f->bsize * v;
704 
705 	__set_bit(rule, pos);
706 }
707 
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  */
743 static 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  */
789 static 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  */
834 static 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 
867 	new_lt = kvzalloc(lt_size + NFT_PIPAPO_ALIGN_HEADROOM, GFP_KERNEL);
868 	if (!new_lt)
869 		return;
870 
871 	NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4;
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 {
881 		BUG();
882 	}
883 
884 	f->groups = groups;
885 	f->bb = bb;
886 	kvfree(f->lt);
887 	NFT_PIPAPO_LT_ASSIGN(f, new_lt);
888 }
889 
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  */
901 static int pipapo_insert(struct nft_pipapo_field *f, const uint8_t *k,
902 			 int mask_bits)
903 {
904 	int rule = f->rules++, group, ret, bit_offset = 0;
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 
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;
917 
918 		bit_offset += f->bb;
919 		bit_offset %= BITS_PER_BYTE;
920 
921 		if (mask_bits >= (group + 1) * f->bb) {
922 			/* Not masked */
923 			pipapo_bucket_set(f, rule, group, v);
924 		} else if (mask_bits <= group * f->bb) {
925 			/* Completely masked */
926 			for (i = 0; i < NFT_PIPAPO_BUCKETS(f->bb); i++)
927 				pipapo_bucket_set(f, rule, group, i);
928 		} else {
929 			/* The mask limit falls on this group */
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++) {
933 				if ((i & ~mask) == (v & ~mask))
934 					pipapo_bucket_set(f, rule, group, i);
935 			}
936 		}
937 	}
938 
939 	pipapo_lt_bits_adjust(f);
940 
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  */
954 static 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  */
976 static 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  */
1001 static 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  */
1036 static 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 	}
1069 out:
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
1078  * @e:		For last field, nft_set_ext pointer matching rules map to
1079  */
1080 static 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
1102  * @bsize_max:	Maximum bucket size, scratch maps cover two buckets
1103  *
1104  * Return: 0 on success, -ENOMEM on failure.
1105  */
1106 static 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;
1113 #ifdef NFT_PIPAPO_ALIGN
1114 		unsigned long *scratch_aligned;
1115 #endif
1116 
1117 		scratch = kzalloc_node(bsize_max * sizeof(*scratch) * 2 +
1118 				       NFT_PIPAPO_ALIGN_HEADROOM,
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;
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
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  */
1153 static 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 
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 
1172 	dup = pipapo_get(net, set, start, genmask);
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;
1187 		}
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));
1195 	}
1196 
1197 	if (PTR_ERR(dup) != -ENOENT) {
1198 		if (IS_ERR(dup))
1199 			return PTR_ERR(dup);
1200 		*ext2 = &dup->ext;
1201 		return -ENOTEMPTY;
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,
1212 			   f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)) > 0)
1213 			return -EINVAL;
1214 
1215 		start_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
1216 		end_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
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,
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);
1235 
1236 		if (f->bsize > bsize_max)
1237 			bsize_max = f->bsize;
1238 
1239 		rulemap[i].n = ret;
1240 
1241 		start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
1242 		end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
1243 	}
1244 
1245 	if (!*get_cpu_ptr(m->scratch) || bsize_max > m->bsize_max) {
1246 		put_cpu_ptr(m->scratch);
1247 
1248 		err = pipapo_realloc_scratch(m, bsize_max);
1249 		if (err)
1250 			return err;
1251 
1252 		m->bsize_max = bsize_max;
1253 	} else {
1254 		put_cpu_ptr(m->scratch);
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  */
1270 static 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 
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 
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++) {
1300 		unsigned long *new_lt;
1301 
1302 		memcpy(dst, src, offsetof(struct nft_pipapo_field, lt));
1303 
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)
1309 			goto out_lt;
1310 
1311 		NFT_PIPAPO_LT_ASSIGN(dst, new_lt);
1312 
1313 		memcpy(NFT_PIPAPO_LT_ALIGN(new_lt),
1314 		       NFT_PIPAPO_LT_ALIGN(src->lt),
1315 		       src->bsize * sizeof(*dst->lt) *
1316 		       src->groups * NFT_PIPAPO_BUCKETS(src->bb));
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 
1329 out_mt:
1330 	kvfree(dst->lt);
1331 out_lt:
1332 	for (dst--; i > 0; i--) {
1333 		kvfree(dst->mt);
1334 		kvfree(dst->lt);
1335 		dst--;
1336 	}
1337 #ifdef NFT_PIPAPO_ALIGN
1338 	free_percpu(new->scratch_aligned);
1339 #endif
1340 out_scratch:
1341 	free_percpu(new->scratch);
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  */
1376 static 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  */
1432 static 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
1450  * @rulemap:	Table of rule maps, arrays of first rule and amount of rules
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  */
1484 static 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 
1497 			pos = NFT_PIPAPO_LT_ALIGN(f->lt) + g *
1498 			      NFT_PIPAPO_BUCKETS(f->bb) * f->bsize;
1499 
1500 			for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) {
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;
1518 
1519 		pipapo_lt_bits_adjust(f);
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  */
1528 static 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  */
1579 static 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  */
1594 static 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 
1604 #ifdef NFT_PIPAPO_ALIGN
1605 	free_percpu(m->scratch_aligned);
1606 #endif
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  */
1625 static 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  */
1662 static 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  */
1691 static 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  */
1713 static 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  */
1740 static 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  */
1796 static int pipapo_get_boundaries(struct nft_pipapo_field *f, int first_rule,
1797 				 int rule_count, u8 *left, u8 *right)
1798 {
1799 	int g, mask_len = 0, bit_offset = 0;
1800 	u8 *l = left, *r = right;
1801 
1802 	for (g = 0; g < f->groups; g++) {
1803 		int b, x0, x1;
1804 
1805 		x0 = -1;
1806 		x1 = -1;
1807 		for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) {
1808 			unsigned long *pos;
1809 
1810 			pos = NFT_PIPAPO_LT_ALIGN(f->lt) +
1811 			      (g * NFT_PIPAPO_BUCKETS(f->bb) + b) * f->bsize;
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 
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++;
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  */
1851 static 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 
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));
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  */
1876 static void nft_pipapo_remove(const struct net *net, const struct nft_set *set,
1877 			      const struct nft_set_elem *elem)
1878 {
1879 	struct nft_pipapo *priv = nft_set_priv(set);
1880 	struct nft_pipapo_match *m = priv->clone;
1881 	struct nft_pipapo_elem *e = elem->priv;
1882 	int rules_f0, first_rule = 0;
1883 	const u8 *data;
1884 
1885 	data = (const u8 *)nft_set_ext_key(&e->ext);
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 
1914 			match_start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
1915 			match_end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f);
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  */
1939 static 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 
1976 cont:
1977 		iter->count++;
1978 	}
1979 
1980 out:
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  */
1991 static 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 /**
1998  * nft_pipapo_estimate() - Set size, space and lookup complexity
1999  * @desc:	Set description, element count and field description used
2000  * @features:	Flags: NFT_SET_INTERVAL needs to be there
2001  * @est:	Storage for estimation data
2002  *
2003  * Return: true if set description is compatible, false otherwise
2004  */
2005 static bool nft_pipapo_estimate(const struct nft_set_desc *desc, u32 features,
2006 				struct nft_set_estimate *est)
2007 {
2008 	if (!(features & NFT_SET_INTERVAL) ||
2009 	    desc->field_count < NFT_PIPAPO_MIN_FIELDS)
2010 		return false;
2011 
2012 	est->size = pipapo_estimate_size(desc);
2013 	if (!est->size)
2014 		return false;
2015 
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  */
2035 static 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;
2042 	int err, i, field_count;
2043 
2044 	field_count = desc->field_count ? : 1;
2045 
2046 	if (field_count > NFT_PIPAPO_MAX_FIELDS)
2047 		return -EINVAL;
2048 
2049 	m = kmalloc(sizeof(*priv->match) + sizeof(*f) * field_count,
2050 		    GFP_KERNEL);
2051 	if (!m)
2052 		return -ENOMEM;
2053 
2054 	m->field_count = field_count;
2055 	m->bsize_max = 0;
2056 
2057 	m->scratch = alloc_percpu(unsigned long *);
2058 	if (!m->scratch) {
2059 		err = -ENOMEM;
2060 		goto out_scratch;
2061 	}
2062 	for_each_possible_cpu(i)
2063 		*per_cpu_ptr(m->scratch, i) = NULL;
2064 
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 
2075 	rcu_head_init(&m->rcu);
2076 
2077 	nft_pipapo_for_each_field(f, i, m) {
2078 		int len = desc->field_len[i] ? : set->klen;
2079 
2080 		f->bb = NFT_PIPAPO_GROUP_BITS_INIT;
2081 		f->groups = len * NFT_PIPAPO_GROUPS_PER_BYTE(f);
2082 
2083 		priv->width += round_up(len, sizeof(u32));
2084 
2085 		f->bsize = 0;
2086 		f->rules = 0;
2087 		NFT_PIPAPO_LT_ASSIGN(f, NULL);
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 
2104 out_free:
2105 #ifdef NFT_PIPAPO_ALIGN
2106 	free_percpu(m->scratch_aligned);
2107 #endif
2108 	free_percpu(m->scratch);
2109 out_scratch:
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  */
2119 static 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 
2144 #ifdef NFT_PIPAPO_ALIGN
2145 		free_percpu(m->scratch_aligned);
2146 #endif
2147 		for_each_possible_cpu(cpu)
2148 			kfree(*per_cpu_ptr(m->scratch, cpu));
2149 		free_percpu(m->scratch);
2150 		pipapo_free_fields(m);
2151 		kfree(m);
2152 		priv->match = NULL;
2153 	}
2154 
2155 	if (priv->clone) {
2156 #ifdef NFT_PIPAPO_ALIGN
2157 		free_percpu(priv->clone->scratch_aligned);
2158 #endif
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  */
2178 static 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 
2185 const struct nft_set_type nft_set_pipapo_type = {
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 };
2205 
2206 #if defined(CONFIG_X86_64) && !defined(CONFIG_UML)
2207 const 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
2228