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- // SPDX-License-Identifier: GPL-2.0-only
- #ifndef _NFT_SET_PIPAPO_H
- #include <linux/log2.h>
- #include <net/ipv6.h> /* For the maximum length of a field */
- /* Count of concatenated fields depends on count of 32-bit nftables registers */
- #define NFT_PIPAPO_MAX_FIELDS NFT_REG32_COUNT
- /* Restrict usage to multiple fields, make sure rbtree is used otherwise */
- #define NFT_PIPAPO_MIN_FIELDS 2
- /* Largest supported field size */
- #define NFT_PIPAPO_MAX_BYTES (sizeof(struct in6_addr))
- #define NFT_PIPAPO_MAX_BITS (NFT_PIPAPO_MAX_BYTES * BITS_PER_BYTE)
- /* Bits to be grouped together in table buckets depending on set size */
- #define NFT_PIPAPO_GROUP_BITS_INIT NFT_PIPAPO_GROUP_BITS_SMALL_SET
- #define NFT_PIPAPO_GROUP_BITS_SMALL_SET 8
- #define NFT_PIPAPO_GROUP_BITS_LARGE_SET 4
- #define NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4 \
- BUILD_BUG_ON((NFT_PIPAPO_GROUP_BITS_SMALL_SET != 8) || \
- (NFT_PIPAPO_GROUP_BITS_LARGE_SET != 4))
- #define NFT_PIPAPO_GROUPS_PER_BYTE(f) (BITS_PER_BYTE / (f)->bb)
- /* If a lookup table gets bigger than NFT_PIPAPO_LT_SIZE_HIGH, switch to the
- * small group width, and switch to the big group width if the table gets
- * smaller than NFT_PIPAPO_LT_SIZE_LOW.
- *
- * Picking 2MiB as threshold (for a single table) avoids as much as possible
- * crossing page boundaries on most architectures (x86-64 and MIPS huge pages,
- * ARMv7 supersections, POWER "large" pages, SPARC Level 1 regions, etc.), which
- * keeps performance nice in case kvmalloc() gives us non-contiguous areas.
- */
- #define NFT_PIPAPO_LT_SIZE_THRESHOLD (1 << 21)
- #define NFT_PIPAPO_LT_SIZE_HYSTERESIS (1 << 16)
- #define NFT_PIPAPO_LT_SIZE_HIGH NFT_PIPAPO_LT_SIZE_THRESHOLD
- #define NFT_PIPAPO_LT_SIZE_LOW NFT_PIPAPO_LT_SIZE_THRESHOLD - \
- NFT_PIPAPO_LT_SIZE_HYSTERESIS
- /* Fields are padded to 32 bits in input registers */
- #define NFT_PIPAPO_GROUPS_PADDED_SIZE(f) \
- (round_up((f)->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f), sizeof(u32)))
- #define NFT_PIPAPO_GROUPS_PADDING(f) \
- (NFT_PIPAPO_GROUPS_PADDED_SIZE(f) - (f)->groups / \
- NFT_PIPAPO_GROUPS_PER_BYTE(f))
- /* Number of buckets given by 2 ^ n, with n bucket bits */
- #define NFT_PIPAPO_BUCKETS(bb) (1 << (bb))
- /* Each n-bit range maps to up to n * 2 rules */
- #define NFT_PIPAPO_MAP_NBITS (const_ilog2(NFT_PIPAPO_MAX_BITS * 2))
- /* Use the rest of mapping table buckets for rule indices, but it makes no sense
- * to exceed 32 bits
- */
- #if BITS_PER_LONG == 64
- #define NFT_PIPAPO_MAP_TOBITS 32
- #else
- #define NFT_PIPAPO_MAP_TOBITS (BITS_PER_LONG - NFT_PIPAPO_MAP_NBITS)
- #endif
- /* ...which gives us the highest allowed index for a rule */
- #define NFT_PIPAPO_RULE0_MAX ((1UL << (NFT_PIPAPO_MAP_TOBITS - 1)) \
- - (1UL << NFT_PIPAPO_MAP_NBITS))
- /* Definitions for vectorised implementations */
- #ifdef NFT_PIPAPO_ALIGN
- #define NFT_PIPAPO_ALIGN_HEADROOM \
- (NFT_PIPAPO_ALIGN - ARCH_KMALLOC_MINALIGN)
- #define NFT_PIPAPO_LT_ALIGN(lt) (PTR_ALIGN((lt), NFT_PIPAPO_ALIGN))
- #define NFT_PIPAPO_LT_ASSIGN(field, x) \
- do { \
- (field)->lt_aligned = NFT_PIPAPO_LT_ALIGN(x); \
- (field)->lt = (x); \
- } while (0)
- #else
- #define NFT_PIPAPO_ALIGN_HEADROOM 0
- #define NFT_PIPAPO_LT_ALIGN(lt) (lt)
- #define NFT_PIPAPO_LT_ASSIGN(field, x) ((field)->lt = (x))
- #endif /* NFT_PIPAPO_ALIGN */
- #define nft_pipapo_for_each_field(field, index, match) \
- for ((field) = (match)->f, (index) = 0; \
- (index) < (match)->field_count; \
- (index)++, (field)++)
- /**
- * union nft_pipapo_map_bucket - Bucket of mapping table
- * @to: First rule number (in next field) this rule maps to
- * @n: Number of rules (in next field) this rule maps to
- * @e: If there's no next field, pointer to element this rule maps to
- */
- union nft_pipapo_map_bucket {
- struct {
- #if BITS_PER_LONG == 64
- static_assert(NFT_PIPAPO_MAP_TOBITS <= 32);
- u32 to;
- static_assert(NFT_PIPAPO_MAP_NBITS <= 32);
- u32 n;
- #else
- unsigned long to:NFT_PIPAPO_MAP_TOBITS;
- unsigned long n:NFT_PIPAPO_MAP_NBITS;
- #endif
- };
- struct nft_pipapo_elem *e;
- };
- /**
- * struct nft_pipapo_field - Lookup, mapping tables and related data for a field
- * @groups: Amount of bit groups
- * @rules: Number of inserted rules
- * @bsize: Size of each bucket in lookup table, in longs
- * @bb: Number of bits grouped together in lookup table buckets
- * @lt: Lookup table: 'groups' rows of buckets
- * @lt_aligned: Version of @lt aligned to NFT_PIPAPO_ALIGN bytes
- * @mt: Mapping table: one bucket per rule
- */
- struct nft_pipapo_field {
- int groups;
- unsigned long rules;
- size_t bsize;
- int bb;
- #ifdef NFT_PIPAPO_ALIGN
- unsigned long *lt_aligned;
- #endif
- unsigned long *lt;
- union nft_pipapo_map_bucket *mt;
- };
- /**
- * struct nft_pipapo_match - Data used for lookup and matching
- * @field_count Amount of fields in set
- * @scratch: Preallocated per-CPU maps for partial matching results
- * @scratch_aligned: Version of @scratch aligned to NFT_PIPAPO_ALIGN bytes
- * @bsize_max: Maximum lookup table bucket size of all fields, in longs
- * @rcu Matching data is swapped on commits
- * @f: Fields, with lookup and mapping tables
- */
- struct nft_pipapo_match {
- int field_count;
- #ifdef NFT_PIPAPO_ALIGN
- unsigned long * __percpu *scratch_aligned;
- #endif
- unsigned long * __percpu *scratch;
- size_t bsize_max;
- struct rcu_head rcu;
- struct nft_pipapo_field f[];
- };
- /**
- * struct nft_pipapo - Representation of a set
- * @match: Currently in-use matching data
- * @clone: Copy where pending insertions and deletions are kept
- * @width: Total bytes to be matched for one packet, including padding
- * @dirty: Working copy has pending insertions or deletions
- * @last_gc: Timestamp of last garbage collection run, jiffies
- */
- struct nft_pipapo {
- struct nft_pipapo_match __rcu *match;
- struct nft_pipapo_match *clone;
- int width;
- bool dirty;
- unsigned long last_gc;
- };
- struct nft_pipapo_elem;
- /**
- * struct nft_pipapo_elem - API-facing representation of single set element
- * @ext: nftables API extensions
- */
- struct nft_pipapo_elem {
- struct nft_set_ext ext;
- };
- int pipapo_refill(unsigned long *map, int len, int rules, unsigned long *dst,
- union nft_pipapo_map_bucket *mt, bool match_only);
- bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set,
- const u32 *key, const struct nft_set_ext **ext);
- /**
- * pipapo_and_field_buckets_4bit() - Intersect 4-bit buckets
- * @f: Field including lookup table
- * @dst: Area to store result
- * @data: Input data selecting table buckets
- */
- static inline void pipapo_and_field_buckets_4bit(struct nft_pipapo_field *f,
- unsigned long *dst,
- const u8 *data)
- {
- unsigned long *lt = NFT_PIPAPO_LT_ALIGN(f->lt);
- int group;
- for (group = 0; group < f->groups; group += BITS_PER_BYTE / 4, data++) {
- u8 v;
- v = *data >> 4;
- __bitmap_and(dst, dst, lt + v * f->bsize,
- f->bsize * BITS_PER_LONG);
- lt += f->bsize * NFT_PIPAPO_BUCKETS(4);
- v = *data & 0x0f;
- __bitmap_and(dst, dst, lt + v * f->bsize,
- f->bsize * BITS_PER_LONG);
- lt += f->bsize * NFT_PIPAPO_BUCKETS(4);
- }
- }
- /**
- * pipapo_and_field_buckets_8bit() - Intersect 8-bit buckets
- * @f: Field including lookup table
- * @dst: Area to store result
- * @data: Input data selecting table buckets
- */
- static inline void pipapo_and_field_buckets_8bit(struct nft_pipapo_field *f,
- unsigned long *dst,
- const u8 *data)
- {
- unsigned long *lt = NFT_PIPAPO_LT_ALIGN(f->lt);
- int group;
- for (group = 0; group < f->groups; group++, data++) {
- __bitmap_and(dst, dst, lt + *data * f->bsize,
- f->bsize * BITS_PER_LONG);
- lt += f->bsize * NFT_PIPAPO_BUCKETS(8);
- }
- }
- /**
- * pipapo_estimate_size() - Estimate worst-case for set size
- * @desc: Set description, element count and field description used here
- *
- * The size for this set type can vary dramatically, as it depends on the number
- * of rules (composing netmasks) the entries expand to. We compute the worst
- * case here.
- *
- * In general, for a non-ranged entry or a single composing netmask, we need
- * one bit in each of the sixteen NFT_PIPAPO_BUCKETS, for each 4-bit group (that
- * is, each input bit needs four bits of matching data), plus a bucket in the
- * mapping table for each field.
- *
- * Return: worst-case set size in bytes, 0 on any overflow
- */
- static u64 pipapo_estimate_size(const struct nft_set_desc *desc)
- {
- unsigned long entry_size;
- u64 size;
- int i;
- for (i = 0, entry_size = 0; i < desc->field_count; i++) {
- unsigned long rules;
- if (desc->field_len[i] > NFT_PIPAPO_MAX_BYTES)
- return 0;
- /* Worst-case ranges for each concatenated field: each n-bit
- * field can expand to up to n * 2 rules in each bucket, and
- * each rule also needs a mapping bucket.
- */
- rules = ilog2(desc->field_len[i] * BITS_PER_BYTE) * 2;
- entry_size += rules *
- NFT_PIPAPO_BUCKETS(NFT_PIPAPO_GROUP_BITS_INIT) /
- BITS_PER_BYTE;
- entry_size += rules * sizeof(union nft_pipapo_map_bucket);
- }
- /* Rules in lookup and mapping tables are needed for each entry */
- size = desc->size * entry_size;
- if (size && div_u64(size, desc->size) != entry_size)
- return 0;
- size += sizeof(struct nft_pipapo) + sizeof(struct nft_pipapo_match) * 2;
- size += sizeof(struct nft_pipapo_field) * desc->field_count;
- return size;
- }
- #endif /* _NFT_SET_PIPAPO_H */
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