[PATCH net v2 0/2] fix glitch in IPVS /proc handlers

[PATCH net v2 0/2] fix glitch in IPVS /proc handlers

[Matteo Croce]

Fix a bug which shows negative values in IPVS /proc handlers.
Also add an helper function to calculate a time delta

Matteo Croce (2):
  jiffies: add utility function to calculate delta in ms
  ipvs: don't show negative times in ip_vs_conn

 include/linux/jiffies.h         |  5 +++++
 net/netfilter/ipvs/ip_vs_conn.c | 22 ++++++++++++++--------
 2 files changed, 19 insertions(+), 8 deletions(-)

-- 
2.17.1

[PATCH net v2 1/2] jiffies: add utility function to calculate delta in ms

[Matteo Croce]

add jiffies_delta_to_msecs() helper func to calculate the delta between
two times and eventually 0 if negative.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Matteo Croce <mcroce@redhat.com>
---
 include/linux/jiffies.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index a27cf6652327..fa928242567d 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -447,6 +447,11 @@ static inline clock_t jiffies_delta_to_clock_t(long delta)
 	return jiffies_to_clock_t(max(0L, delta));
 }
 
+static inline unsigned int jiffies_delta_to_msecs(long delta)
+{
+	return jiffies_to_msecs(max(0L, delta));
+}
+
 extern unsigned long clock_t_to_jiffies(unsigned long x);
 extern u64 jiffies_64_to_clock_t(u64 x);
 extern u64 nsec_to_clock_t(u64 x);
-- 
2.17.1

[PATCH net v2 2/2] ipvs: don't show negative times in ip_vs_conn

[Matteo Croce]

Since commit 500462a9de65 ("timers: Switch to a non-cascading wheel"),
timers duration can last even 12.5% more than the scheduled interval.

IPVS has two handlers, /proc/net/ip_vs_conn and /proc/net/ip_vs_conn_sync,
which shows the remaining time before that a connection expires.
The default expire time for a connection is 60 seconds, and the
expiration timer can fire even 4 seconds later than the scheduled time.
The expiration time is calculated subtracting jiffies to the scheduled
expiration time, and it's shown as a huge number when the timer fires late,
since both values are unsigned.

This can confuse script and tools which relies on it, like ipvsadm:

    root@mcroce-redhat:~# while ipvsadm -lc |grep SYN_RECV; do sleep 1 ; done
    TCP 00:05  SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 00:04  SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 00:03  SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 00:02  SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 00:01  SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 00:00  SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 68719476:44 SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 68719476:43 SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 68719476:42 SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 68719476:41 SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 68719476:40 SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000
    TCP 68719476:39 SYN_RECV    [fc00:1::1]:55732  [fc00:1::2]:8000   [fc00:2000::1]:8000

Signed-off-by: Matteo Croce <mcroce@redhat.com>
---
 net/netfilter/ipvs/ip_vs_conn.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index 99e0aa350dc5..615286dcf4c0 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -1102,24 +1102,28 @@ static int ip_vs_conn_seq_show(struct seq_file *seq, void *v)
 #ifdef CONFIG_IP_VS_IPV6
 		if (cp->af == AF_INET6)
 			seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
-				"%s %04X %-11s %7lu%s\n",
+				"%s %04X %-11s %7u%s\n",
 				ip_vs_proto_name(cp->protocol),
 				&cp->caddr.in6, ntohs(cp->cport),
 				&cp->vaddr.in6, ntohs(cp->vport),
 				dbuf, ntohs(cp->dport),
 				ip_vs_state_name(cp->protocol, cp->state),
-				(cp->timer.expires-jiffies)/HZ, pe_data);
+				jiffies_delta_to_msecs(cp->timer.expires -
+						       jiffies) / 1000,
+				pe_data);
 		else
 #endif
 			seq_printf(seq,
 				"%-3s %08X %04X %08X %04X"
-				" %s %04X %-11s %7lu%s\n",
+				" %s %04X %-11s %7u%s\n",
 				ip_vs_proto_name(cp->protocol),
 				ntohl(cp->caddr.ip), ntohs(cp->cport),
 				ntohl(cp->vaddr.ip), ntohs(cp->vport),
 				dbuf, ntohs(cp->dport),
 				ip_vs_state_name(cp->protocol, cp->state),
-				(cp->timer.expires-jiffies)/HZ, pe_data);
+				jiffies_delta_to_msecs(cp->timer.expires -
+						       jiffies) / 1000,
+				pe_data);
 	}
 	return 0;
 }
@@ -1164,26 +1168,28 @@ static int ip_vs_conn_sync_seq_show(struct seq_file *seq, void *v)
 #ifdef CONFIG_IP_VS_IPV6
 		if (cp->af == AF_INET6)
 			seq_printf(seq, "%-3s %pI6 %04X %pI6 %04X "
-				"%s %04X %-11s %-6s %7lu\n",
+				"%s %04X %-11s %-6s %7u\n",
 				ip_vs_proto_name(cp->protocol),
 				&cp->caddr.in6, ntohs(cp->cport),
 				&cp->vaddr.in6, ntohs(cp->vport),
 				dbuf, ntohs(cp->dport),
 				ip_vs_state_name(cp->protocol, cp->state),
 				ip_vs_origin_name(cp->flags),
-				(cp->timer.expires-jiffies)/HZ);
+				jiffies_delta_to_msecs(cp->timer.expires -
+						       jiffies) / 1000);
 		else
 #endif
 			seq_printf(seq,
 				"%-3s %08X %04X %08X %04X "
-				"%s %04X %-11s %-6s %7lu\n",
+				"%s %04X %-11s %-6s %7u\n",
 				ip_vs_proto_name(cp->protocol),
 				ntohl(cp->caddr.ip), ntohs(cp->cport),
 				ntohl(cp->vaddr.ip), ntohs(cp->vport),
 				dbuf, ntohs(cp->dport),
 				ip_vs_state_name(cp->protocol, cp->state),
 				ip_vs_origin_name(cp->flags),
-				(cp->timer.expires-jiffies)/HZ);
+				jiffies_delta_to_msecs(cp->timer.expires -
+						       jiffies) / 1000);
 	}
 	return 0;
 }
-- 
2.17.1

Re: [PATCH net v2 1/2] jiffies: add utility function to calculate delta in ms

[Eric Dumazet]

On 07/31/2018 09:03 AM, Matteo Croce wrote:
> add jiffies_delta_to_msecs() helper func to calculate the delta between
> two times and eventually 0 if negative.
> 
> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
> Signed-off-by: Matteo Croce <mcroce@redhat.com>

Reviewed-by: Eric Dumazet <edumazet@google.com>

Thanks.

Re: [PATCH net v2 0/2] fix glitch in IPVS /proc handlers

[Simon Horman]

On Tue, Jul 31, 2018 at 06:03:31PM +0200, Matteo Croce wrote:
> Fix a bug which shows negative values in IPVS /proc handlers.
> Also add an helper function to calculate a time delta
> 
> Matteo Croce (2):
>   jiffies: add utility function to calculate delta in ms
>   ipvs: don't show negative times in ip_vs_conn

Acked-by: Simon Horman <horms@verge.net.au>

Pablo, please consider taking these via the nf tree.

Re: [PATCH net v2 0/2] fix glitch in IPVS /proc handlers

[Pablo Neira Ayuso]

On Tue, Jul 31, 2018 at 06:28:22PM +0200, Simon Horman wrote:
> On Tue, Jul 31, 2018 at 06:03:31PM +0200, Matteo Croce wrote:
> > Fix a bug which shows negative values in IPVS /proc handlers.
> > Also add an helper function to calculate a time delta
> > 
> > Matteo Croce (2):
> >   jiffies: add utility function to calculate delta in ms
> >   ipvs: don't show negative times in ip_vs_conn
> 
> Acked-by: Simon Horman <horms@verge.net.au>
> 
> Pablo, please consider taking these via the nf tree.

Applied, thanks Simon.

Re: [PATCH net v2 0/2] fix glitch in IPVS /proc handlers

[Pablo Neira Ayuso]

On Tue, Jul 31, 2018 at 06:03:31PM +0200, Matteo Croce wrote:
> Fix a bug which shows negative values in IPVS /proc handlers.
> Also add an helper function to calculate a time delta

Series applied, thanks Matteo.