[ 08/94] isdn/gigaset: ratelimit CAPI message dumps

From: Greg KH
Date: Sat May 26 2012 - 21:06:19 EST


3.3-stable review patch. If anyone has any objections, please let me know.

------------------

From: Tilman Schmidt <tilman@xxxxxxx>

commit 8e618aad5348b6e6c5a90e8d97ea643197963b20 upstream.

Introduce a global ratelimit for CAPI message dumps to protect
against possible log flood.
Drop the ratelimit for ignored messages which is now covered by the
global one.

Signed-off-by: Tilman Schmidt <tilman@xxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/isdn/gigaset/capi.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)

--- a/drivers/isdn/gigaset/capi.c
+++ b/drivers/isdn/gigaset/capi.c
@@ -14,6 +14,7 @@
#include "gigaset.h"
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
+#include <linux/ratelimit.h>
#include <linux/isdn/capilli.h>
#include <linux/isdn/capicmd.h>
#include <linux/isdn/capiutil.h>
@@ -223,10 +224,14 @@ get_appl(struct gigaset_capi_ctr *iif, u
static inline void dump_cmsg(enum debuglevel level, const char *tag, _cmsg *p)
{
#ifdef CONFIG_GIGASET_DEBUG
+ /* dump at most 20 messages in 20 secs */
+ static DEFINE_RATELIMIT_STATE(msg_dump_ratelimit, 20 * HZ, 20);
_cdebbuf *cdb;

if (!(gigaset_debuglevel & level))
return;
+ if (!___ratelimit(&msg_dump_ratelimit, tag))
+ return;

cdb = capi_cmsg2str(p);
if (cdb) {
@@ -2059,12 +2064,6 @@ static void do_reset_b3_req(struct gigas
}

/*
- * dump unsupported/ignored messages at most twice per minute,
- * some apps send those very frequently
- */
-static unsigned long ignored_msg_dump_time;
-
-/*
* unsupported CAPI message handler
*/
static void do_unsupported(struct gigaset_capi_ctr *iif,
@@ -2073,8 +2072,7 @@ static void do_unsupported(struct gigase
{
/* decode message */
capi_message2cmsg(&iif->acmsg, skb->data);
- if (printk_timed_ratelimit(&ignored_msg_dump_time, 30 * 1000))
- dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
+ dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
send_conf(iif, ap, skb, CapiMessageNotSupportedInCurrentState);
}

@@ -2085,11 +2083,9 @@ static void do_nothing(struct gigaset_ca
struct gigaset_capi_appl *ap,
struct sk_buff *skb)
{
- if (printk_timed_ratelimit(&ignored_msg_dump_time, 30 * 1000)) {
- /* decode message */
- capi_message2cmsg(&iif->acmsg, skb->data);
- dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
- }
+ /* decode message */
+ capi_message2cmsg(&iif->acmsg, skb->data);
+ dump_cmsg(DEBUG_CMD, __func__, &iif->acmsg);
dev_kfree_skb_any(skb);
}



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