nefilter: eache: reduce struct size from 32 to 24 byte

Florian Westphal · ummakynes · commit 01026edef906 · 2017-04-19T17:55:17.000+02:00
Only "cache" needs to use ulong (its used with set_bit()), missed can use
u16.  Also add build-time assertion to ensure event bits fit.

Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
diff --git a/include/net/netfilter/nf_conntrack_ecache.h b/include/net/netfilter/nf_conntrack_ecache.h
@@ -20,11 +20,11 @@ enum nf_ct_ecache_state {
 
 struct nf_conntrack_ecache {
 	unsigned long cache;		/* bitops want long */
-	unsigned long missed;		/* missed events */
+	u16 missed;			/* missed events */
 	u16 ctmask;			/* bitmask of ct events to be delivered */
 	u16 expmask;			/* bitmask of expect events to be delivered */
+	enum nf_ct_ecache_state state:8;/* ecache state */
 	u32 portid;			/* netlink portid of destroyer */
-	enum nf_ct_ecache_state state;	/* ecache state */
 };
 
 static inline struct nf_conntrack_ecache *
diff --git a/include/uapi/linux/netfilter/nf_conntrack_common.h b/include/uapi/linux/netfilter/nf_conntrack_common.h
@@ -119,6 +119,9 @@ enum ip_conntrack_events {
 	IPCT_NATSEQADJ = IPCT_SEQADJ,
 	IPCT_SECMARK,		/* new security mark has been set */
 	IPCT_LABEL,		/* new connlabel has been set */
+#ifdef __KERNEL__
+	__IPCT_MAX
+#endif
 };
 
 enum ip_conntrack_expect_events {
diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c
@@ -420,6 +420,9 @@ int nf_conntrack_ecache_init(void)
 	int ret = nf_ct_extend_register(&event_extend);
 	if (ret < 0)
 		pr_err("nf_ct_event: Unable to register event extension.\n");
+
+	BUILD_BUG_ON(__IPCT_MAX >= 16);	/* ctmask, missed use u16 */
+
 	return ret;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -420,6 +420,9 @@ int nf_conntrack_ecache_init(void)`
`420`	`420`	`int ret = nf_ct_extend_register(&event_extend);`
`421`	`421`	`if (ret < 0)`
`422`	`422`	`pr_err("nf_ct_event: Unable to register event extension.\n");`
	`423`	`+`
	`424`	`+ BUILD_BUG_ON(__IPCT_MAX >= 16); /* ctmask, missed use u16 */`
	`425`	`+`
`423`	`426`	`return ret;`
`424`	`427`	`}`
`425`	`428`