Commit b71ed54d authored Jul 31, 2018 by Matteo Croce Committed by Pablo Neira Ayuso Aug 16, 2018

ipvs: don't show negative times in ip_vs_conn

Since commit 500462a9 ("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>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

parent 14d32b25

net/netfilter/ipvs/ip_vs_conn.c

+14 −8

Original line number	Diff line number	Diff line
		@@ -1117,24 +1117,28 @@ 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),
		(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),
		(cp->timer.expires-jiffies)/HZ, pe_data);
		jiffies_delta_to_msecs(cp->timer.expires -
		jiffies) / 1000,
		pe_data);
		}
		return 0;
		}
		@@ -1179,26 +1183,28 @@ 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),
		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),
		ip_vs_origin_name(cp->flags),
		(cp->timer.expires-jiffies)/HZ);
		jiffies_delta_to_msecs(cp->timer.expires -
		jiffies) / 1000);
		}
		return 0;
		}