netfilter: xt_connbytes: Force CT accounting to be enabled

Check at rule install time that CT accounting is enabled. Force it
to be enabled if not while also emitting a warning since this is not
the default state.

This is in preparation for deprecating CONFIG_NF_CT_ACCT upon which
CONFIG_NETFILTER_XT_MATCH_CONNBYTES depended being set.

Added 2 CT accounting support functions:

nf_ct_acct_enabled() - Get CT accounting state.
nf_ct_set_acct() - Enable/disable CT accountuing.

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Tim Gardner 2010-06-25 14:44:07 +02:00 committed by Patrick McHardy
parent fe6fb55285
commit a8756201ba
2 changed files with 22 additions and 0 deletions

View file

@ -45,6 +45,18 @@ struct nf_conn_counter *nf_ct_acct_ext_add(struct nf_conn *ct, gfp_t gfp)
extern unsigned int
seq_print_acct(struct seq_file *s, const struct nf_conn *ct, int dir);
/* Check if connection tracking accounting is enabled */
static inline bool nf_ct_acct_enabled(struct net *net)
{
return net->ct.sysctl_acct != 0;
}
/* Enable/disable connection tracking accounting */
static inline void nf_ct_set_acct(struct net *net, bool enable)
{
net->ct.sysctl_acct = enable;
}
extern int nf_conntrack_acct_init(struct net *net);
extern void nf_conntrack_acct_fini(struct net *net);

View file

@ -112,6 +112,16 @@ static int connbytes_mt_check(const struct xt_mtchk_param *par)
if (ret < 0)
pr_info("cannot load conntrack support for proto=%u\n",
par->family);
/*
* This filter cannot function correctly unless connection tracking
* accounting is enabled, so complain in the hope that someone notices.
*/
if (!nf_ct_acct_enabled(par->net)) {
pr_warning("Forcing CT accounting to be enabled\n");
nf_ct_set_acct(par->net, true);
}
return ret;
}