cregit-Linux how code gets into the kernel

Release 4.11 net/netfilter/nft_hash.c

Directory: net/netfilter
/*
 * Copyright (c) 2016 Laura Garcia <nevola@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <linux/jhash.h>


struct nft_hash {
	
enum nft_registers      sreg:8;
	
enum nft_registers      dreg:8;
	
u8			len;
	
bool			autogen_seed:1;
	
u32			modulus;
	
u32			seed;
	
u32			offset;
};


static void nft_hash_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) { struct nft_hash *priv = nft_expr_priv(expr); const void *data = &regs->data[priv->sreg]; u32 h; h = reciprocal_scale(jhash(data, priv->len, priv->seed), priv->modulus); regs->data[priv->dreg] = h + priv->offset; }

Contributors

PersonTokensPropCommitsCommitProp
Laura Garcia Liebana88100.00%2100.00%
Total88100.00%2100.00%

static const struct nla_policy nft_hash_policy[NFTA_HASH_MAX + 1] = { [NFTA_HASH_SREG] = { .type = NLA_U32 }, [NFTA_HASH_DREG] = { .type = NLA_U32 }, [NFTA_HASH_LEN] = { .type = NLA_U32 }, [NFTA_HASH_MODULUS] = { .type = NLA_U32 }, [NFTA_HASH_SEED] = { .type = NLA_U32 }, [NFTA_HASH_OFFSET] = { .type = NLA_U32 }, };
static int nft_hash_init(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nlattr * const tb[]) { struct nft_hash *priv = nft_expr_priv(expr); u32 len; int err; if (!tb[NFTA_HASH_SREG] || !tb[NFTA_HASH_DREG] || !tb[NFTA_HASH_LEN] || !tb[NFTA_HASH_MODULUS]) return -EINVAL; if (tb[NFTA_HASH_OFFSET]) priv->offset = ntohl(nla_get_be32(tb[NFTA_HASH_OFFSET])); priv->sreg = nft_parse_register(tb[NFTA_HASH_SREG]); priv->dreg = nft_parse_register(tb[NFTA_HASH_DREG]); err = nft_parse_u32_check(tb[NFTA_HASH_LEN], U8_MAX, &len); if (err < 0) return err; if (len == 0) return -ERANGE; priv->len = len; priv->modulus = ntohl(nla_get_be32(tb[NFTA_HASH_MODULUS])); if (priv->modulus <= 1) return -ERANGE; if (priv->offset + priv->modulus - 1 < priv->offset) return -EOVERFLOW; if (tb[NFTA_HASH_SEED]) { priv->seed = ntohl(nla_get_be32(tb[NFTA_HASH_SEED])); } else { priv->autogen_seed = true; get_random_bytes(&priv->seed, sizeof(priv->seed)); } return nft_validate_register_load(priv->sreg, len) && nft_validate_register_store(ctx, priv->dreg, NULL, NFT_DATA_VALUE, sizeof(u32)); }

Contributors

PersonTokensPropCommitsCommitProp
Laura Garcia Liebana24888.26%466.67%
Pablo Neira Ayuso238.19%116.67%
Liping Zhang103.56%116.67%
Total281100.00%6100.00%


static int nft_hash_dump(struct sk_buff *skb, const struct nft_expr *expr) { const struct nft_hash *priv = nft_expr_priv(expr); if (nft_dump_register(skb, NFTA_HASH_SREG, priv->sreg)) goto nla_put_failure; if (nft_dump_register(skb, NFTA_HASH_DREG, priv->dreg)) goto nla_put_failure; if (nla_put_be32(skb, NFTA_HASH_LEN, htonl(priv->len))) goto nla_put_failure; if (nla_put_be32(skb, NFTA_HASH_MODULUS, htonl(priv->modulus))) goto nla_put_failure; if (!priv->autogen_seed && nla_put_be32(skb, NFTA_HASH_SEED, htonl(priv->seed))) goto nla_put_failure; if (priv->offset != 0) if (nla_put_be32(skb, NFTA_HASH_OFFSET, htonl(priv->offset))) goto nla_put_failure; return 0; nla_put_failure: return -1; }

Contributors

PersonTokensPropCommitsCommitProp
Laura Garcia Liebana14189.24%250.00%
Pablo Neira Ayuso127.59%125.00%
Liping Zhang53.16%125.00%
Total158100.00%4100.00%

static struct nft_expr_type nft_hash_type; static const struct nft_expr_ops nft_hash_ops = { .type = &nft_hash_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_hash)), .eval = nft_hash_eval, .init = nft_hash_init, .dump = nft_hash_dump, }; static struct nft_expr_type nft_hash_type __read_mostly = { .name = "hash", .ops = &nft_hash_ops, .policy = nft_hash_policy, .maxattr = NFTA_HASH_MAX, .owner = THIS_MODULE, };
static int __init nft_hash_module_init(void) { return nft_register_expr(&nft_hash_type); }

Contributors

PersonTokensPropCommitsCommitProp
Laura Garcia Liebana16100.00%1100.00%
Total16100.00%1100.00%


static void __exit nft_hash_module_exit(void) { nft_unregister_expr(&nft_hash_type); }

Contributors

PersonTokensPropCommitsCommitProp
Laura Garcia Liebana15100.00%1100.00%
Total15100.00%1100.00%

module_init(nft_hash_module_init); module_exit(nft_hash_module_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Laura Garcia <nevola@gmail.com>"); MODULE_ALIAS_NFT_EXPR("hash");

Overall Contributors

PersonTokensPropCommitsCommitProp
Laura Garcia Liebana73791.67%444.44%
Pablo Neira Ayuso354.35%222.22%
Liping Zhang313.86%222.22%
Wei Yongjun10.12%111.11%
Total804100.00%9100.00%
Directory: net/netfilter
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