| Message ID | alpine.LNX.2.00.0809192040250.22510@titan.stealer.net |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Fri, Sep 19, 2008 at 08:41:56PM +0200, Sven Wegener wrote: > The nr_conns variable in the sync message header is only eight bits wide > and will overflow on interfaces with a large MTU. As a result the backup > won't parse all connections contained in the sync buffer. On regular > ethernet with an MTU of 1500 this isn't a problem, because we can't > overflow the value, but consider jumbo frames being used on a cross-over > connection between both directors. > > We now restrict the size of the sync buffer, so that we never put more > than 255 connections into a single sync buffer. > > Signed-off-by: Sven Wegener <sven.wegener@stealer.net> Thanks Sven, applied.
diff --git a/net/ipv4/ipvs/ip_vs_sync.c b/net/ipv4/ipvs/ip_vs_sync.c index 28237a5..de5e7e1 100644 --- a/net/ipv4/ipvs/ip_vs_sync.c +++ b/net/ipv4/ipvs/ip_vs_sync.c @@ -30,6 +30,7 @@ #include <linux/err.h> #include <linux/kthread.h> #include <linux/wait.h> +#include <linux/kernel.h> #include <net/ip.h> #include <net/sock.h> @@ -99,6 +100,7 @@ struct ip_vs_sync_thread_data { */ #define SYNC_MESG_HEADER_LEN 4 +#define MAX_CONNS_PER_SYNCBUFF 255 /* nr_conns in ip_vs_sync_mesg is 8 bit */ struct ip_vs_sync_mesg { __u8 nr_conns; @@ -516,8 +518,8 @@ static int set_sync_mesg_maxlen(int sync_state) num = (dev->mtu - sizeof(struct iphdr) - sizeof(struct udphdr) - SYNC_MESG_HEADER_LEN - 20) / SIMPLE_CONN_SIZE; - sync_send_mesg_maxlen = - SYNC_MESG_HEADER_LEN + SIMPLE_CONN_SIZE * num; + sync_send_mesg_maxlen = SYNC_MESG_HEADER_LEN + + SIMPLE_CONN_SIZE * min(num, MAX_CONNS_PER_SYNCBUFF); IP_VS_DBG(7, "setting the maximum length of sync sending " "message %d.\n", sync_send_mesg_maxlen); } else if (sync_state == IP_VS_STATE_BACKUP) {
The nr_conns variable in the sync message header is only eight bits wide and will overflow on interfaces with a large MTU. As a result the backup won't parse all connections contained in the sync buffer. On regular ethernet with an MTU of 1500 this isn't a problem, because we can't overflow the value, but consider jumbo frames being used on a cross-over connection between both directors. We now restrict the size of the sync buffer, so that we never put more than 255 connections into a single sync buffer. Signed-off-by: Sven Wegener <sven.wegener@stealer.net>