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1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | ||
3 | #ifndef _NFT_SET_PIPAPO_H | |
4 | ||
5 | #include <linux/log2.h> | |
6 | #include <net/ipv6.h> /* For the maximum length of a field */ | |
7 | ||
8 | /* Count of concatenated fields depends on count of 32-bit nftables registers */ | |
9 | #define NFT_PIPAPO_MAX_FIELDS NFT_REG32_COUNT | |
10 | ||
eb16933a SB |
11 | /* Restrict usage to multiple fields, make sure rbtree is used otherwise */ |
12 | #define NFT_PIPAPO_MIN_FIELDS 2 | |
13 | ||
8683f4b9 SB |
14 | /* Largest supported field size */ |
15 | #define NFT_PIPAPO_MAX_BYTES (sizeof(struct in6_addr)) | |
16 | #define NFT_PIPAPO_MAX_BITS (NFT_PIPAPO_MAX_BYTES * BITS_PER_BYTE) | |
17 | ||
18 | /* Bits to be grouped together in table buckets depending on set size */ | |
19 | #define NFT_PIPAPO_GROUP_BITS_INIT NFT_PIPAPO_GROUP_BITS_SMALL_SET | |
20 | #define NFT_PIPAPO_GROUP_BITS_SMALL_SET 8 | |
21 | #define NFT_PIPAPO_GROUP_BITS_LARGE_SET 4 | |
22 | #define NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4 \ | |
23 | BUILD_BUG_ON((NFT_PIPAPO_GROUP_BITS_SMALL_SET != 8) || \ | |
24 | (NFT_PIPAPO_GROUP_BITS_LARGE_SET != 4)) | |
25 | #define NFT_PIPAPO_GROUPS_PER_BYTE(f) (BITS_PER_BYTE / (f)->bb) | |
26 | ||
27 | /* If a lookup table gets bigger than NFT_PIPAPO_LT_SIZE_HIGH, switch to the | |
28 | * small group width, and switch to the big group width if the table gets | |
29 | * smaller than NFT_PIPAPO_LT_SIZE_LOW. | |
30 | * | |
31 | * Picking 2MiB as threshold (for a single table) avoids as much as possible | |
32 | * crossing page boundaries on most architectures (x86-64 and MIPS huge pages, | |
33 | * ARMv7 supersections, POWER "large" pages, SPARC Level 1 regions, etc.), which | |
34 | * keeps performance nice in case kvmalloc() gives us non-contiguous areas. | |
35 | */ | |
36 | #define NFT_PIPAPO_LT_SIZE_THRESHOLD (1 << 21) | |
37 | #define NFT_PIPAPO_LT_SIZE_HYSTERESIS (1 << 16) | |
38 | #define NFT_PIPAPO_LT_SIZE_HIGH NFT_PIPAPO_LT_SIZE_THRESHOLD | |
39 | #define NFT_PIPAPO_LT_SIZE_LOW NFT_PIPAPO_LT_SIZE_THRESHOLD - \ | |
40 | NFT_PIPAPO_LT_SIZE_HYSTERESIS | |
41 | ||
42 | /* Fields are padded to 32 bits in input registers */ | |
43 | #define NFT_PIPAPO_GROUPS_PADDED_SIZE(f) \ | |
44 | (round_up((f)->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f), sizeof(u32))) | |
45 | #define NFT_PIPAPO_GROUPS_PADDING(f) \ | |
46 | (NFT_PIPAPO_GROUPS_PADDED_SIZE(f) - (f)->groups / \ | |
47 | NFT_PIPAPO_GROUPS_PER_BYTE(f)) | |
48 | ||
49 | /* Number of buckets given by 2 ^ n, with n bucket bits */ | |
50 | #define NFT_PIPAPO_BUCKETS(bb) (1 << (bb)) | |
51 | ||
52 | /* Each n-bit range maps to up to n * 2 rules */ | |
53 | #define NFT_PIPAPO_MAP_NBITS (const_ilog2(NFT_PIPAPO_MAX_BITS * 2)) | |
54 | ||
55 | /* Use the rest of mapping table buckets for rule indices, but it makes no sense | |
56 | * to exceed 32 bits | |
57 | */ | |
58 | #if BITS_PER_LONG == 64 | |
59 | #define NFT_PIPAPO_MAP_TOBITS 32 | |
60 | #else | |
61 | #define NFT_PIPAPO_MAP_TOBITS (BITS_PER_LONG - NFT_PIPAPO_MAP_NBITS) | |
62 | #endif | |
63 | ||
64 | /* ...which gives us the highest allowed index for a rule */ | |
65 | #define NFT_PIPAPO_RULE0_MAX ((1UL << (NFT_PIPAPO_MAP_TOBITS - 1)) \ | |
66 | - (1UL << NFT_PIPAPO_MAP_NBITS)) | |
67 | ||
68 | /* Definitions for vectorised implementations */ | |
69 | #ifdef NFT_PIPAPO_ALIGN | |
70 | #define NFT_PIPAPO_ALIGN_HEADROOM \ | |
71 | (NFT_PIPAPO_ALIGN - ARCH_KMALLOC_MINALIGN) | |
72 | #define NFT_PIPAPO_LT_ALIGN(lt) (PTR_ALIGN((lt), NFT_PIPAPO_ALIGN)) | |
73 | #define NFT_PIPAPO_LT_ASSIGN(field, x) \ | |
74 | do { \ | |
75 | (field)->lt_aligned = NFT_PIPAPO_LT_ALIGN(x); \ | |
76 | (field)->lt = (x); \ | |
77 | } while (0) | |
78 | #else | |
79 | #define NFT_PIPAPO_ALIGN_HEADROOM 0 | |
80 | #define NFT_PIPAPO_LT_ALIGN(lt) (lt) | |
81 | #define NFT_PIPAPO_LT_ASSIGN(field, x) ((field)->lt = (x)) | |
82 | #endif /* NFT_PIPAPO_ALIGN */ | |
83 | ||
84 | #define nft_pipapo_for_each_field(field, index, match) \ | |
85 | for ((field) = (match)->f, (index) = 0; \ | |
86 | (index) < (match)->field_count; \ | |
87 | (index)++, (field)++) | |
88 | ||
89 | /** | |
90 | * union nft_pipapo_map_bucket - Bucket of mapping table | |
91 | * @to: First rule number (in next field) this rule maps to | |
92 | * @n: Number of rules (in next field) this rule maps to | |
93 | * @e: If there's no next field, pointer to element this rule maps to | |
94 | */ | |
95 | union nft_pipapo_map_bucket { | |
96 | struct { | |
97 | #if BITS_PER_LONG == 64 | |
98 | static_assert(NFT_PIPAPO_MAP_TOBITS <= 32); | |
99 | u32 to; | |
100 | ||
101 | static_assert(NFT_PIPAPO_MAP_NBITS <= 32); | |
102 | u32 n; | |
103 | #else | |
104 | unsigned long to:NFT_PIPAPO_MAP_TOBITS; | |
105 | unsigned long n:NFT_PIPAPO_MAP_NBITS; | |
106 | #endif | |
107 | }; | |
108 | struct nft_pipapo_elem *e; | |
109 | }; | |
110 | ||
111 | /** | |
112 | * struct nft_pipapo_field - Lookup, mapping tables and related data for a field | |
113 | * @groups: Amount of bit groups | |
114 | * @rules: Number of inserted rules | |
115 | * @bsize: Size of each bucket in lookup table, in longs | |
116 | * @bb: Number of bits grouped together in lookup table buckets | |
117 | * @lt: Lookup table: 'groups' rows of buckets | |
118 | * @lt_aligned: Version of @lt aligned to NFT_PIPAPO_ALIGN bytes | |
119 | * @mt: Mapping table: one bucket per rule | |
120 | */ | |
121 | struct nft_pipapo_field { | |
122 | int groups; | |
123 | unsigned long rules; | |
124 | size_t bsize; | |
125 | int bb; | |
126 | #ifdef NFT_PIPAPO_ALIGN | |
127 | unsigned long *lt_aligned; | |
128 | #endif | |
129 | unsigned long *lt; | |
130 | union nft_pipapo_map_bucket *mt; | |
131 | }; | |
132 | ||
133 | /** | |
134 | * struct nft_pipapo_match - Data used for lookup and matching | |
135 | * @field_count Amount of fields in set | |
136 | * @scratch: Preallocated per-CPU maps for partial matching results | |
137 | * @scratch_aligned: Version of @scratch aligned to NFT_PIPAPO_ALIGN bytes | |
138 | * @bsize_max: Maximum lookup table bucket size of all fields, in longs | |
139 | * @rcu Matching data is swapped on commits | |
140 | * @f: Fields, with lookup and mapping tables | |
141 | */ | |
142 | struct nft_pipapo_match { | |
143 | int field_count; | |
144 | #ifdef NFT_PIPAPO_ALIGN | |
145 | unsigned long * __percpu *scratch_aligned; | |
146 | #endif | |
147 | unsigned long * __percpu *scratch; | |
148 | size_t bsize_max; | |
149 | struct rcu_head rcu; | |
150 | struct nft_pipapo_field f[]; | |
151 | }; | |
152 | ||
153 | /** | |
154 | * struct nft_pipapo - Representation of a set | |
155 | * @match: Currently in-use matching data | |
156 | * @clone: Copy where pending insertions and deletions are kept | |
157 | * @width: Total bytes to be matched for one packet, including padding | |
158 | * @dirty: Working copy has pending insertions or deletions | |
159 | * @last_gc: Timestamp of last garbage collection run, jiffies | |
160 | */ | |
161 | struct nft_pipapo { | |
162 | struct nft_pipapo_match __rcu *match; | |
163 | struct nft_pipapo_match *clone; | |
164 | int width; | |
165 | bool dirty; | |
166 | unsigned long last_gc; | |
167 | }; | |
168 | ||
169 | struct nft_pipapo_elem; | |
170 | ||
171 | /** | |
172 | * struct nft_pipapo_elem - API-facing representation of single set element | |
173 | * @ext: nftables API extensions | |
174 | */ | |
175 | struct nft_pipapo_elem { | |
176 | struct nft_set_ext ext; | |
177 | }; | |
178 | ||
179 | int pipapo_refill(unsigned long *map, int len, int rules, unsigned long *dst, | |
180 | union nft_pipapo_map_bucket *mt, bool match_only); | |
181 | ||
182 | /** | |
183 | * pipapo_and_field_buckets_4bit() - Intersect 4-bit buckets | |
184 | * @f: Field including lookup table | |
185 | * @dst: Area to store result | |
186 | * @data: Input data selecting table buckets | |
187 | */ | |
188 | static inline void pipapo_and_field_buckets_4bit(struct nft_pipapo_field *f, | |
189 | unsigned long *dst, | |
190 | const u8 *data) | |
191 | { | |
192 | unsigned long *lt = NFT_PIPAPO_LT_ALIGN(f->lt); | |
193 | int group; | |
194 | ||
195 | for (group = 0; group < f->groups; group += BITS_PER_BYTE / 4, data++) { | |
196 | u8 v; | |
197 | ||
198 | v = *data >> 4; | |
199 | __bitmap_and(dst, dst, lt + v * f->bsize, | |
200 | f->bsize * BITS_PER_LONG); | |
201 | lt += f->bsize * NFT_PIPAPO_BUCKETS(4); | |
202 | ||
203 | v = *data & 0x0f; | |
204 | __bitmap_and(dst, dst, lt + v * f->bsize, | |
205 | f->bsize * BITS_PER_LONG); | |
206 | lt += f->bsize * NFT_PIPAPO_BUCKETS(4); | |
207 | } | |
208 | } | |
209 | ||
210 | /** | |
211 | * pipapo_and_field_buckets_8bit() - Intersect 8-bit buckets | |
212 | * @f: Field including lookup table | |
213 | * @dst: Area to store result | |
214 | * @data: Input data selecting table buckets | |
215 | */ | |
216 | static inline void pipapo_and_field_buckets_8bit(struct nft_pipapo_field *f, | |
217 | unsigned long *dst, | |
218 | const u8 *data) | |
219 | { | |
220 | unsigned long *lt = NFT_PIPAPO_LT_ALIGN(f->lt); | |
221 | int group; | |
222 | ||
223 | for (group = 0; group < f->groups; group++, data++) { | |
224 | __bitmap_and(dst, dst, lt + *data * f->bsize, | |
225 | f->bsize * BITS_PER_LONG); | |
226 | lt += f->bsize * NFT_PIPAPO_BUCKETS(8); | |
227 | } | |
228 | } | |
229 | ||
230 | /** | |
231 | * pipapo_estimate_size() - Estimate worst-case for set size | |
232 | * @desc: Set description, element count and field description used here | |
233 | * | |
234 | * The size for this set type can vary dramatically, as it depends on the number | |
235 | * of rules (composing netmasks) the entries expand to. We compute the worst | |
236 | * case here. | |
237 | * | |
238 | * In general, for a non-ranged entry or a single composing netmask, we need | |
239 | * one bit in each of the sixteen NFT_PIPAPO_BUCKETS, for each 4-bit group (that | |
240 | * is, each input bit needs four bits of matching data), plus a bucket in the | |
241 | * mapping table for each field. | |
242 | * | |
243 | * Return: worst-case set size in bytes, 0 on any overflow | |
244 | */ | |
245 | static u64 pipapo_estimate_size(const struct nft_set_desc *desc) | |
246 | { | |
247 | unsigned long entry_size; | |
248 | u64 size; | |
249 | int i; | |
250 | ||
251 | for (i = 0, entry_size = 0; i < desc->field_count; i++) { | |
252 | unsigned long rules; | |
253 | ||
254 | if (desc->field_len[i] > NFT_PIPAPO_MAX_BYTES) | |
255 | return 0; | |
256 | ||
257 | /* Worst-case ranges for each concatenated field: each n-bit | |
258 | * field can expand to up to n * 2 rules in each bucket, and | |
259 | * each rule also needs a mapping bucket. | |
260 | */ | |
261 | rules = ilog2(desc->field_len[i] * BITS_PER_BYTE) * 2; | |
262 | entry_size += rules * | |
263 | NFT_PIPAPO_BUCKETS(NFT_PIPAPO_GROUP_BITS_INIT) / | |
264 | BITS_PER_BYTE; | |
265 | entry_size += rules * sizeof(union nft_pipapo_map_bucket); | |
266 | } | |
267 | ||
268 | /* Rules in lookup and mapping tables are needed for each entry */ | |
269 | size = desc->size * entry_size; | |
270 | if (size && div_u64(size, desc->size) != entry_size) | |
271 | return 0; | |
272 | ||
273 | size += sizeof(struct nft_pipapo) + sizeof(struct nft_pipapo_match) * 2; | |
274 | ||
275 | size += sizeof(struct nft_pipapo_field) * desc->field_count; | |
276 | ||
277 | return size; | |
278 | } | |
279 | ||
280 | #endif /* _NFT_SET_PIPAPO_H */ |