From 48a71a20420e307d0a1d8a89ac9fc7b46ec5a1ca Mon Sep 17 00:00:00 2001 From: Laura Garcia Liebana Date: Sat, 13 Aug 2016 01:02:03 +0200 Subject: expr: add hash expression Support for the nft hash expression in libnftnl. Signed-off-by: Laura Garcia Liebana Signed-off-by: Pablo Neira Ayuso --- src/expr/hash.c | 294 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 294 insertions(+) create mode 100644 src/expr/hash.c (limited to 'src/expr') diff --git a/src/expr/hash.c b/src/expr/hash.c new file mode 100644 index 0000000..7309907 --- /dev/null +++ b/src/expr/hash.c @@ -0,0 +1,294 @@ +/* + * (C) 2016 by Laura Garcia + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include +#include +#include +#include +#include +#include + +#include "internal.h" +#include +#include +#include + +struct nftnl_expr_hash { + enum nft_registers sreg; + enum nft_registers dreg; + unsigned int len; + unsigned int modulus; + unsigned int seed; +}; + +static int +nftnl_expr_hash_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_hash *hash = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_HASH_SREG: + hash->sreg = *((uint32_t *)data); + break; + case NFTNL_EXPR_HASH_DREG: + hash->dreg = *((uint32_t *)data); + break; + case NFTNL_EXPR_HASH_LEN: + hash->len = *((uint32_t *)data); + break; + case NFTNL_EXPR_HASH_MODULUS: + hash->modulus = *((uint32_t *)data); + break; + case NFTNL_EXPR_HASH_SEED: + hash->seed = *((uint32_t *)data); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_hash_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_hash *hash = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_HASH_SREG: + *data_len = sizeof(hash->sreg); + return &hash->sreg; + case NFTNL_EXPR_HASH_DREG: + *data_len = sizeof(hash->dreg); + return &hash->dreg; + case NFTNL_EXPR_HASH_LEN: + *data_len = sizeof(hash->len); + return &hash->len; + case NFTNL_EXPR_HASH_MODULUS: + *data_len = sizeof(hash->modulus); + return &hash->modulus; + case NFTNL_EXPR_HASH_SEED: + *data_len = sizeof(hash->seed); + return &hash->seed; + } + return NULL; +} + +static int nftnl_expr_hash_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, NFTA_HASH_MAX) < 0) + return MNL_CB_OK; + + switch (type) { + case NFTA_HASH_SREG: + case NFTA_HASH_DREG: + case NFTA_HASH_LEN: + case NFTA_HASH_MODULUS: + case NFTA_HASH_SEED: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_hash_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_hash *hash = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_HASH_SREG)) + mnl_attr_put_u32(nlh, NFTA_HASH_SREG, htonl(hash->sreg)); + if (e->flags & (1 << NFTNL_EXPR_HASH_DREG)) + mnl_attr_put_u32(nlh, NFTA_HASH_DREG, htonl(hash->dreg)); + if (e->flags & (1 << NFTNL_EXPR_HASH_LEN)) + mnl_attr_put_u32(nlh, NFTA_HASH_LEN, htonl(hash->len)); + if (e->flags & (1 << NFTNL_EXPR_HASH_MODULUS)) + mnl_attr_put_u32(nlh, NFTA_HASH_MODULUS, htonl(hash->modulus)); + if (e->flags & (1 << NFTNL_EXPR_HASH_SEED)) + mnl_attr_put_u32(nlh, NFTA_HASH_SEED, htonl(hash->seed)); + +} + +static int +nftnl_expr_hash_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_hash *hash = nftnl_expr_data(e); + struct nlattr *tb[NFTA_HASH_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_expr_hash_cb, tb) < 0) + return -1; + + if (tb[NFTA_HASH_SREG]) { + hash->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_SREG])); + e->flags |= (1 << NFTNL_EXPR_HASH_SREG); + } + if (tb[NFTA_HASH_DREG]) { + hash->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_DREG])); + e->flags |= (1 << NFTNL_EXPR_HASH_DREG); + } + if (tb[NFTA_HASH_LEN]) { + hash->len = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_LEN])); + e->flags |= (1 << NFTNL_EXPR_HASH_LEN); + } + if (tb[NFTA_HASH_MODULUS]) { + hash->modulus = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_MODULUS])); + e->flags |= (1 << NFTNL_EXPR_HASH_MODULUS); + } + if (tb[NFTA_HASH_SEED]) { + hash->seed = ntohl(mnl_attr_get_u32(tb[NFTA_HASH_SEED])); + e->flags |= (1 << NFTNL_EXPR_HASH_SEED); + } + + return ret; +} + +static int nftnl_expr_hash_json_parse(struct nftnl_expr *e, json_t *root, + struct nftnl_parse_err *err) +{ +#ifdef JSON_PARSING + uint32_t sreg, dreg, len, modulus, seed; + + if (nftnl_jansson_parse_reg(root, "sreg", NFTNL_TYPE_U32, + &sreg, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_SREG, sreg); + + if (nftnl_jansson_parse_reg(root, "dreg", NFTNL_TYPE_U32, + &dreg, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_DREG, dreg); + + if (nftnl_jansson_parse_val(root, "len", NFTNL_TYPE_U32, + &len, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_LEN, len); + + if (nftnl_jansson_parse_val(root, "modulus", NFTNL_TYPE_U32, + &modulus, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_MODULUS, modulus); + + if (nftnl_jansson_parse_val(root, "seed", NFTNL_TYPE_U32, + &seed, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_SEED, seed); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + + +static int nftnl_expr_hash_xml_parse(struct nftnl_expr *e, + mxml_node_t *tree, + struct nftnl_parse_err *err) +{ +#ifdef XML_PARSING + uint32_t sreg, dreg, len, modulus, seed; + + if (nftnl_mxml_reg_parse(tree, "sreg", &sreg, MXML_DESCEND_FIRST, + NFTNL_XML_MAND, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_SREG, sreg); + + if (nftnl_mxml_reg_parse(tree, "dreg", &dreg, MXML_DESCEND_FIRST, + NFTNL_XML_MAND, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_DREG, dreg); + + if (nftnl_mxml_num_parse(tree, "len", MXML_DESCEND_FIRST, BASE_DEC, + &len, NFTNL_TYPE_U32, NFTNL_XML_MAND, + err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_LEN, len); + + if (nftnl_mxml_num_parse(tree, "modulus", MXML_DESCEND_FIRST, BASE_DEC, + &modulus, NFTNL_TYPE_U32, NFTNL_XML_MAND, + err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_MODULUS, modulus); + + if (nftnl_mxml_num_parse(tree, "seed", MXML_DESCEND_FIRST, BASE_DEC, + &seed, NFTNL_TYPE_U32, NFTNL_XML_MAND, + err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_HASH_SEED, seed); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + +static int +nftnl_expr_hash_snprintf_default(char *buf, size_t size, + const struct nftnl_expr *e) +{ + struct nftnl_expr_hash *hash = nftnl_expr_data(e); + int len = size, offset = 0, ret; + + ret = snprintf(buf, len, "reg %u = jhash(reg %u, %u, %u) %% modulus %u", + hash->dreg, hash->sreg, hash->len, hash->seed, + hash->modulus); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + + return offset; +} + +static int nftnl_expr_hash_export(char *buf, size_t size, + const struct nftnl_expr *e, int type) +{ + struct nftnl_expr_hash *hash = nftnl_expr_data(e); + + NFTNL_BUF_INIT(b, buf, size); + + if (e->flags & (1 << NFTNL_EXPR_HASH_SREG)) + nftnl_buf_u32(&b, type, hash->sreg, SREG); + if (e->flags & (1 << NFTNL_EXPR_HASH_DREG)) + nftnl_buf_u32(&b, type, hash->dreg, DREG); + if (e->flags & (1 << NFTNL_EXPR_HASH_LEN)) + nftnl_buf_u32(&b, type, hash->len, LEN); + if (e->flags & (1 << NFTNL_EXPR_HASH_MODULUS)) + nftnl_buf_u32(&b, type, hash->modulus, MODULUS); + if (e->flags & (1 << NFTNL_EXPR_HASH_SEED)) + nftnl_buf_u32(&b, type, hash->seed, SEED); + + return nftnl_buf_done(&b); +} + +static int +nftnl_expr_hash_snprintf(char *buf, size_t len, uint32_t type, + uint32_t flags, const struct nftnl_expr *e) +{ + switch (type) { + case NFTNL_OUTPUT_DEFAULT: + return nftnl_expr_hash_snprintf_default(buf, len, e); + case NFTNL_OUTPUT_XML: + case NFTNL_OUTPUT_JSON: + return nftnl_expr_hash_export(buf, len, e, type); + default: + break; + } + return -1; +} + +struct expr_ops expr_ops_hash = { + .name = "hash", + .alloc_len = sizeof(struct nftnl_expr_hash), + .max_attr = NFTA_HASH_MAX, + .set = nftnl_expr_hash_set, + .get = nftnl_expr_hash_get, + .parse = nftnl_expr_hash_parse, + .build = nftnl_expr_hash_build, + .snprintf = nftnl_expr_hash_snprintf, + .xml_parse = nftnl_expr_hash_xml_parse, + .json_parse = nftnl_expr_hash_json_parse, +}; -- cgit v1.2.3