@@ -34,10 +34,13 @@ nf_conntrack_count - INTEGER (read-only)
nf_conntrack_events - BOOLEAN
- 0 - disabled
- - not 0 - enabled (default)
+ - 1 - enabled
+ - 2 - auto (default)
If this option is enabled, the connection tracking code will
provide userspace with connection tracking events via ctnetlink.
+ The default allocates the extension if a userspace program is
+ listening to ctnetlink events.
nf_conntrack_expect_max - INTEGER
Maximum size of expectation table. Default value is
@@ -1739,7 +1739,8 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
#ifdef CONFIG_NF_CONNTRACK_EVENTS
ecache = tmpl ? nf_ct_ecache_find(tmpl) : NULL;
- if (!nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
+ if ((ecache || net->ct.sysctl_events) &&
+ !nf_ct_ecache_ext_add(ct, ecache ? ecache->ctmask : 0,
ecache ? ecache->expmask : 0,
GFP_ATOMIC)) {
nf_conntrack_free(ct);
@@ -303,12 +303,27 @@ bool nf_ct_ecache_ext_add(struct nf_conn *ct, u16 ctmask, u16 expmask, gfp_t gfp
struct net *net = nf_ct_net(ct);
struct nf_conntrack_ecache *e;
- if (!ctmask && !expmask && net->ct.sysctl_events) {
- ctmask = ~0;
- expmask = ~0;
+ switch (net->ct.sysctl_events) {
+ case 0:
+ /* assignment via template / ruleset? ignore sysctl. */
+ if (ctmask || expmask)
+ break;
+ return true;
+ case 2: /* autodetect: no event listener, don't allocate extension. */
+ if (!READ_ONCE(net->ct.ctnetlink_has_listener))
+ return true;
+ fallthrough;
+ case 1:
+ /* always allocate an extension. */
+ if (!ctmask && !expmask) {
+ ctmask = ~0;
+ expmask = ~0;
+ }
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return true;
}
- if (!ctmask && !expmask)
- return false;
e = nf_ct_ext_add(ct, NF_CT_EXT_ECACHE, gfp);
if (e) {
@@ -320,7 +335,7 @@ bool nf_ct_ecache_ext_add(struct nf_conn *ct, u16 ctmask, u16 expmask, gfp_t gfp
}
EXPORT_SYMBOL_GPL(nf_ct_ecache_ext_add);
-#define NF_CT_EVENTS_DEFAULT 1
+#define NF_CT_EVENTS_DEFAULT 2
static int nf_ct_events __read_mostly = NF_CT_EVENTS_DEFAULT;
void nf_conntrack_ecache_pernet_init(struct net *net)
@@ -693,7 +693,7 @@ static struct ctl_table nf_ct_sysctl_table[] = {
.mode = 0644,
.proc_handler = proc_dou8vec_minmax,
.extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
+ .extra2 = SYSCTL_TWO,
},
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP