Messages in this thread | | | Subject | Re: [PATCH] enhance usability of /proc/sys/net/ipv4/ip_local_reserved_ports | From | Cong Wang <> | Date | Mon, 12 Mar 2012 11:42:39 +0800 |
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Hello, Helge,
On Sun, 2012-03-11 at 00:36 +0100, Helge Deller wrote: > When writing to the ip_local_reserved_ports proc file it will currently clear > all previously reserved ports and update the current list with the one given > in the input. > > This behaviour makes it's usage quite hard, for example: > a) The generic proc filesystem limitation of only handle up to PAGE_SIZE-1 > characters at maximum may not be sufficient to provide all your wished-to- > be-reserved ports at once.
Yes, this should be extended IMHO.
> b) There is no easy way to disable specific given ports, you always need to > give the full port list at once. This makes shell scripting hard, since > you need to parse everything yourself. > c) There is no easy way to just add specific ports or port ranges. Again, > this would be useful for shell scripts. >
These could be calculated in user-space, although it maybe not as easy as you want.
> The following patch solves this problem by simply extending the parser > in proc_do_large_bitmap() to accept the keywords "add" and "release" in front > of given ports or port ranges and to either add or drop the given ports > from the already existing list.
This looks a little odd, because we do "magic" things with a sysctl file, which is supposed to be plain text file. Do we have existing examples?
BTW, as David mentioned, please Cc netdev next time.
Thanks.
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