On Mon, 15 Oct 2007 13:06:14 -0700 (PDT) David Miller <[EMAIL PROTECTED]> wrote:
> From: Andrew Morton <[EMAIL PROTECTED]> > Date: Mon, 15 Oct 2007 12:49:19 -0700 > > > This code has recently been reworked, but from my reading, that > > divide-by-zero can still occur. And given that the numbers in > > /proc/sys/net/ipv4/ip_local_port_range are inclusive, the arithmetic in > > inet_csk_get_port() seems to just be wrong? > > > > So we have this, against David's current devel tree: > > I'm pretty sure we took care of this, but maybe not :-) <looks> OK, in ipv4_local_port_range() we have if (range[1] <= range[0]) ret = -EINVAL; which will prevent the crashes. But is it good to disallow high=low? This disallows a port range of one single port. Unless "high" is exclusive. But Documentation/filesystems/proc.txt says : ip_local_port_range : ------------------- : : Range of ports used by TCP and UDP to choose the local port. Contains two : numbers, the first number is the lowest port, the second number the highest : local port. Default is 1024-4999. Should be changed to 32768-61000 for : high-usage systems. ie: inclusive. Documentation/networking/ip-sysctl.txt says : ip_local_port_range - 2 INTEGERS : Defines the local port range that is used by TCP and UDP to : choose the local port. The first number is the first, the : second the last local port number. Default value depends on : amount of memory available on the system: : > 128Mb 32768-61000 : < 128Mb 1024-4999 or even less. : This number defines number of active connections, which this : system can issue simultaneously to systems not supporting : TCP extensions (timestamps). With tcp_tw_recycle enabled : (i.e. by default) range 1024-4999 is enough to issue up to : 2000 connections per second to systems supporting timestamps. also inclusive. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/