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alistair23-linux/net/netfilter/nft_hash.c
David S. Miller a01aa920b8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 
Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter updates for your net-next
tree. A large bunch of code cleanups, simplify the conntrack extension
codebase, get rid of the fake conntrack object, speed up netns by
selective synchronize_net() calls. More specifically, they are:

1) Check for ct->status bit instead of using nfct_nat() from IPVS and
   Netfilter codebase, patch from Florian Westphal.

2) Use kcalloc() wherever possible in the IPVS code, from Varsha Rao.

3) Simplify FTP IPVS helper module registration path, from Arushi Singhal.

4) Introduce nft_is_base_chain() helper function.

5) Enforce expectation limit from userspace conntrack helper,
   from Gao Feng.

6) Add nf_ct_remove_expect() helper function, from Gao Feng.

7) NAT mangle helper function return boolean, from Gao Feng.

8) ctnetlink_alloc_expect() should only work for conntrack with
   helpers, from Gao Feng.

9) Add nfnl_msg_type() helper function to nfnetlink to build the
   netlink message type.

10) Get rid of unnecessary cast on void, from simran singhal.

11) Use seq_puts()/seq_putc() instead of seq_printf() where possible,
    also from simran singhal.

12) Use list_prev_entry() from nf_tables, from simran signhal.

13) Remove unnecessary & on pointer function in the Netfilter and IPVS
    code.

14) Remove obsolete comment on set of rules per CPU in ip6_tables,
    no longer true. From Arushi Singhal.

15) Remove duplicated nf_conntrack_l4proto_udplite4, from Gao Feng.

16) Remove unnecessary nested rcu_read_lock() in
    __nf_nat_decode_session(). Code running from hooks are already
    guaranteed to run under RCU read side.

17) Remove deadcode in nf_tables_getobj(), from Aaron Conole.

18) Remove double assignment in nf_ct_l4proto_pernet_unregister_one(),
    also from Aaron.

19) Get rid of unsed __ip_set_get_netlink(), from Aaron Conole.

20) Don't propagate NF_DROP error to userspace via ctnetlink in
    __nf_nat_alloc_null_binding() function, from Gao Feng.

21) Revisit nf_ct_deliver_cached_events() to remove unnecessary checks,
    from Gao Feng.

22) Kill the fake untracked conntrack objects, use ctinfo instead to
    annotate a conntrack object is untracked, from Florian Westphal.

23) Remove nf_ct_is_untracked(), now obsolete since we have no
    conntrack template anymore, from Florian.

24) Add event mask support to nft_ct, also from Florian.

25) Move nf_conn_help structure to
    include/net/netfilter/nf_conntrack_helper.h.

26) Add a fixed 32 bytes scratchpad area for conntrack helpers.
    Thus, we don't deal with variable conntrack extensions anymore.
    Make sure userspace conntrack helper doesn't go over that size.
    Remove variable size ct extension infrastructure now this code
    got no more clients. From Florian Westphal.

27) Restore offset and length of nf_ct_ext structure to 8 bytes now
    that wraparound is not possible any longer, also from Florian.

28) Allow to get rid of unassured flows under stress in conntrack,
    this applies to DCCP, SCTP and TCP protocols, from Florian.

29) Shrink size of nf_conntrack_ecache structure, from Florian.

30) Use TCP_MAX_WSCALE instead of hardcoded 14 in TCP tracker,
    from Gao Feng.

31) Register SYNPROXY hooks on demand, from Florian Westphal.

32) Use pernet hook whenever possible, instead of global hook
    registration, from Florian Westphal.

33) Pass hook structure to ebt_register_table() to consolidate some
    infrastructure code, from Florian Westphal.

34) Use consume_skb() and return NF_STOLEN, instead of NF_DROP in the
    SYNPROXY code, to make sure device stats are not fooled, patch
    from Gao Feng.

35) Remove NF_CT_EXT_F_PREALLOC this kills quite some code that we
    don't need anymore if we just select a fixed size instead of
    expensive runtime time calculation of this. From Florian.

36) Constify nf_ct_extend_register() and nf_ct_extend_unregister(),
    from Florian.

37) Simplify nf_ct_ext_add(), this kills nf_ct_ext_create(), from
    Florian.

38) Attach NAT extension on-demand from masquerade and pptp helper
    path, from Florian.

39) Get rid of useless ip_vs_set_state_timeout(), from Aaron Conole.

40) Speed up netns by selective calls of synchronize_net(), from
    Florian Westphal.

41) Silence stack size warning gcc in 32-bit arch in snmp helper,
    from Florian.

42) Inconditionally call nf_ct_ext_destroy(), even if we have no
    extensions, to deal with the NF_NAT_MANIP_SRC case. Patch from
    Liping Zhang.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-01 10:47:53 -04:00

253 lines
6.4 KiB
C
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/*
* 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_jhash {
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_jhash_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
struct nft_jhash *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;
}
struct nft_symhash {
enum nft_registers dreg:8;
u32 modulus;
u32 offset;
};
static void nft_symhash_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
struct nft_symhash *priv = nft_expr_priv(expr);
struct sk_buff *skb = pkt->skb;
u32 h;
h = reciprocal_scale(__skb_get_hash_symmetric(skb), priv->modulus);
regs->data[priv->dreg] = h + priv->offset;
}
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 },
[NFTA_HASH_TYPE] = { .type = NLA_U32 },
};
static int nft_jhash_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_jhash *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));
}
static int nft_symhash_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_symhash *priv = nft_expr_priv(expr);
if (!tb[NFTA_HASH_DREG] ||
!tb[NFTA_HASH_MODULUS])
return -EINVAL;
if (tb[NFTA_HASH_OFFSET])
priv->offset = ntohl(nla_get_be32(tb[NFTA_HASH_OFFSET]));
priv->dreg = nft_parse_register(tb[NFTA_HASH_DREG]);
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;
return nft_validate_register_store(ctx, priv->dreg, NULL,
NFT_DATA_VALUE, sizeof(u32));
}
static int nft_jhash_dump(struct sk_buff *skb,
const struct nft_expr *expr)
{
const struct nft_jhash *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;
if (nla_put_be32(skb, NFTA_HASH_TYPE, htonl(NFT_HASH_JENKINS)))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static int nft_symhash_dump(struct sk_buff *skb,
const struct nft_expr *expr)
{
const struct nft_symhash *priv = nft_expr_priv(expr);
if (nft_dump_register(skb, NFTA_HASH_DREG, priv->dreg))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_HASH_MODULUS, htonl(priv->modulus)))
goto nla_put_failure;
if (priv->offset != 0)
if (nla_put_be32(skb, NFTA_HASH_OFFSET, htonl(priv->offset)))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_HASH_TYPE, htonl(NFT_HASH_SYM)))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static struct nft_expr_type nft_hash_type;
static const struct nft_expr_ops nft_jhash_ops = {
.type = &nft_hash_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_jhash)),
.eval = nft_jhash_eval,
.init = nft_jhash_init,
.dump = nft_jhash_dump,
};
static const struct nft_expr_ops nft_symhash_ops = {
.type = &nft_hash_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_symhash)),
.eval = nft_symhash_eval,
.init = nft_symhash_init,
.dump = nft_symhash_dump,
};
static const struct nft_expr_ops *
nft_hash_select_ops(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
u32 type;
if (!tb[NFTA_HASH_TYPE])
return &nft_jhash_ops;
type = ntohl(nla_get_be32(tb[NFTA_HASH_TYPE]));
switch (type) {
case NFT_HASH_SYM:
return &nft_symhash_ops;
case NFT_HASH_JENKINS:
return &nft_jhash_ops;
default:
break;
}
return ERR_PTR(-EOPNOTSUPP);
}
static struct nft_expr_type nft_hash_type __read_mostly = {
.name = "hash",
.select_ops = nft_hash_select_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);
}
static void __exit nft_hash_module_exit(void)
{
nft_unregister_expr(&nft_hash_type);
}
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");
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