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There have been many people complaining about the inconsistent behaviors of IPv4 and IPv6 devconf when creating new network namespaces. Currently, for IPv4, we inherit all current settings from init_net, but for IPv6 we reset all setting to default. This patch introduces a new /proc file /proc/sys/net/core/devconf_inherit_init_net to control the behavior of whether to inhert sysctl current settings from init_net. This file itself is only available in init_net. As demonstrated below: Initial setup in init_net: # cat /proc/sys/net/ipv4/conf/all/rp_filter 2 # cat /proc/sys/net/ipv6/conf/all/accept_dad 1 Default value 0 (current behavior): # ip netns del test # ip netns add test # ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter 2 # ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad 0 Set to 1 (inherit from init_net): # echo 1 > /proc/sys/net/core/devconf_inherit_init_net # ip netns del test # ip netns add test # ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter 2 # ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad 1 Set to 2 (reset to default): # echo 2 > /proc/sys/net/core/devconf_inherit_init_net # ip netns del test # ip netns add test # ip netns exec test cat /proc/sys/net/ipv4/conf/all/rp_filter 0 # ip netns exec test cat /proc/sys/net/ipv6/conf/all/accept_dad 0 Set to a value out of range (invalid): # echo 3 > /proc/sys/net/core/devconf_inherit_init_net -bash: echo: write error: Invalid argument # echo -1 > /proc/sys/net/core/devconf_inherit_init_net -bash: echo: write error: Invalid argument Reported-by: Zhu Yanjun <Yanjun.Zhu@windriver.com> Reported-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| README | ||
| sunrpc.txt | ||
| user.txt | ||
| vm.txt | ||
Documentation for /proc/sys/ kernel version 2.2.10 (c) 1998, 1999, Rik van Riel <riel@nl.linux.org> 'Why', I hear you ask, 'would anyone even _want_ documentation for them sysctl files? If anybody really needs it, it's all in the source...' Well, this documentation is written because some people either don't know they need to tweak something, or because they don't have the time or knowledge to read the source code. Furthermore, the programmers who built sysctl have built it to be actually used, not just for the fun of programming it :-) ============================================================== Legal blurb: As usual, there are two main things to consider: 1. you get what you pay for 2. it's free The consequences are that I won't guarantee the correctness of this document, and if you come to me complaining about how you screwed up your system because of wrong documentation, I won't feel sorry for you. I might even laugh at you... But of course, if you _do_ manage to screw up your system using only the sysctl options used in this file, I'd like to hear of it. Not only to have a great laugh, but also to make sure that you're the last RTFMing person to screw up. In short, e-mail your suggestions, corrections and / or horror stories to: <riel@nl.linux.org> Rik van Riel. ============================================================== Introduction: Sysctl is a means of configuring certain aspects of the kernel at run-time, and the /proc/sys/ directory is there so that you don't even need special tools to do it! In fact, there are only four things needed to use these config facilities: - a running Linux system - root access - common sense (this is especially hard to come by these days) - knowledge of what all those values mean As a quick 'ls /proc/sys' will show, the directory consists of several (arch-dependent?) subdirs. Each subdir is mainly about one part of the kernel, so you can do configuration on a piece by piece basis, or just some 'thematic frobbing'. The subdirs are about: abi/ execution domains & personalities debug/ <empty> dev/ device specific information (eg dev/cdrom/info) fs/ specific filesystems filehandle, inode, dentry and quota tuning binfmt_misc <Documentation/admin-guide/binfmt-misc.rst> kernel/ global kernel info / tuning miscellaneous stuff net/ networking stuff, for documentation look in: <Documentation/networking/> proc/ <empty> sunrpc/ SUN Remote Procedure Call (NFS) vm/ memory management tuning buffer and cache management user/ Per user per user namespace limits These are the subdirs I have on my system. There might be more or other subdirs in another setup. If you see another dir, I'd really like to hear about it :-)