diff options
Diffstat (limited to 'src/hash.c')
| -rw-r--r-- | src/hash.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/src/hash.c b/src/hash.c new file mode 100644 index 0000000..1c8c00a --- /dev/null +++ b/src/hash.c @@ -0,0 +1,165 @@ +/* + * Hash expression definitions. + * + * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 (or any + * later) as published by the Free Software Foundation. + */ + +#include <nft.h> + +#include <nftables.h> +#include <expression.h> +#include <datatype.h> +#include <gmputil.h> +#include <hash.h> +#include <utils.h> + +static void hash_expr_print(const struct expr *expr, struct output_ctx *octx) +{ + switch (expr->hash.type) { + case NFT_HASH_SYM: + nft_print(octx, "symhash"); + break; + case NFT_HASH_JENKINS: + default: + nft_print(octx, "jhash "); + expr_print(expr->hash.expr, octx); + } + + nft_print(octx, " mod %u", expr->hash.mod); + if (expr->hash.seed_set) + nft_print(octx, " seed 0x%x", expr->hash.seed); + if (expr->hash.offset) + nft_print(octx, " offset %u", expr->hash.offset); +} + +static bool hash_expr_cmp(const struct expr *e1, const struct expr *e2) +{ + return (!e1->hash.expr || + expr_cmp(e1->hash.expr, e2->hash.expr)) && + e1->hash.mod == e2->hash.mod && + e1->hash.seed_set == e2->hash.seed_set && + e1->hash.seed == e2->hash.seed && + e1->hash.offset == e2->hash.offset && + e1->hash.type == e2->hash.type; +} + +static void hash_expr_clone(struct expr *new, const struct expr *expr) +{ + if (expr->hash.expr) + new->hash.expr = expr_clone(expr->hash.expr); + new->hash.mod = expr->hash.mod; + new->hash.seed_set = expr->hash.seed_set; + new->hash.seed = expr->hash.seed; + new->hash.offset = expr->hash.offset; + new->hash.type = expr->hash.type; +} + +static void hash_expr_destroy(struct expr *expr) +{ + expr_free(expr->hash.expr); +} + +#define NFTNL_UDATA_HASH_TYPE 0 +#define NFTNL_UDATA_HASH_OFFSET 1 +#define NFTNL_UDATA_HASH_MOD 2 +#define NFTNL_UDATA_HASH_SEED 3 +#define NFTNL_UDATA_HASH_SEED_SET 4 +#define NFTNL_UDATA_HASH_MAX 5 + +static int hash_expr_build_udata(struct nftnl_udata_buf *udbuf, + const struct expr *expr) +{ + nftnl_udata_put_u32(udbuf, NFTNL_UDATA_HASH_TYPE, expr->hash.type); + nftnl_udata_put_u32(udbuf, NFTNL_UDATA_HASH_OFFSET, expr->hash.offset); + nftnl_udata_put_u32(udbuf, NFTNL_UDATA_HASH_MOD, expr->hash.mod); + nftnl_udata_put_u32(udbuf, NFTNL_UDATA_HASH_SEED, expr->hash.seed); + nftnl_udata_put_u32(udbuf, NFTNL_UDATA_HASH_SEED_SET, expr->hash.seed_set); + + return 0; +} + +static int hash_parse_udata(const struct nftnl_udata *attr, void *data) +{ + const struct nftnl_udata **ud = data; + uint8_t type = nftnl_udata_type(attr); + uint8_t len = nftnl_udata_len(attr); + + switch (type) { + case NFTNL_UDATA_HASH_TYPE: + case NFTNL_UDATA_HASH_OFFSET: + case NFTNL_UDATA_HASH_SEED: + case NFTNL_UDATA_HASH_SEED_SET: + case NFTNL_UDATA_HASH_MOD: + if (len != sizeof(uint32_t)) + return -1; + break; + default: + return 0; + } + + ud[type] = attr; + return 0; +} + +static struct expr *hash_expr_parse_udata(const struct nftnl_udata *attr) +{ + const struct nftnl_udata *ud[NFTNL_UDATA_HASH_MAX + 1] = {}; + uint32_t type, seed, seed_set, mod, offset; + int err; + + err = nftnl_udata_parse(nftnl_udata_get(attr), nftnl_udata_len(attr), + hash_parse_udata, ud); + if (err < 0) + return NULL; + + if (!ud[NFTNL_UDATA_HASH_TYPE] || + !ud[NFTNL_UDATA_HASH_OFFSET] || + !ud[NFTNL_UDATA_HASH_SEED] || + !ud[NFTNL_UDATA_HASH_MOD] || + !ud[NFTNL_UDATA_HASH_SEED_SET]) + return NULL; + + type = nftnl_udata_get_u32(ud[NFTNL_UDATA_HASH_TYPE]); + offset = nftnl_udata_get_u32(ud[NFTNL_UDATA_HASH_OFFSET]); + seed = nftnl_udata_get_u32(ud[NFTNL_UDATA_HASH_SEED]); + seed_set = nftnl_udata_get_u32(ud[NFTNL_UDATA_HASH_SEED_SET]); + mod = nftnl_udata_get_u32(ud[NFTNL_UDATA_HASH_MOD]); + + return hash_expr_alloc(&internal_location, mod, seed_set, seed, + offset, type); +} + +const struct expr_ops hash_expr_ops = { + .type = EXPR_HASH, + .name = "hash", + .print = hash_expr_print, + .json = hash_expr_json, + .cmp = hash_expr_cmp, + .clone = hash_expr_clone, + .destroy = hash_expr_destroy, + .parse_udata = hash_expr_parse_udata, + .build_udata = hash_expr_build_udata, +}; + +struct expr *hash_expr_alloc(const struct location *loc, + uint32_t mod, + bool seed_set, uint32_t seed, + uint32_t offset, + enum nft_hash_types type) +{ + struct expr *expr; + + expr = expr_alloc(loc, EXPR_HASH, &integer_type, + BYTEORDER_HOST_ENDIAN, 4 * BITS_PER_BYTE); + expr->hash.mod = mod; + expr->hash.seed_set = seed_set; + expr->hash.seed = seed; + expr->hash.offset = offset; + expr->hash.type = type; + + return expr; +} |