Jakub Kicinski
14d7b8122f
net: don't allow user space to lift the device limits
Up until commit 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on device creation") the gso_max_segs and gso_max_size of a device were not controlled from user space. The quoted commit added the ability to control them because of the following setup: netns A | netns B veth<->veth eth0 If eth0 has TSO limitations and user wants to efficiently forward traffic between eth0 and the veths they should copy the TSO limitations of eth0 onto the veths. This would happen automatically for macvlans or ipvlan but veth users are not so lucky (given the loose coupling). Unfortunately the commit in question allowed users to also override the limits on real HW devices. It may be useful to control the max GSO size and someone may be using that ability (not that I know of any user), so create a separate set of knobs to reliably record the TSO limitations. Validate the user requests. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
Description
Languages
C
97.6%
Assembly
1%
Shell
0.5%
Python
0.3%
Makefile
0.3%