From: "Jason Vas Dias" <jason.vas.dias@gmail.com>
To: linux-kernel@vger.kernel.org, linux-8086@vger.kernel.org,
ndetdev@vger.kernel.org
Subject: re: /proc/net/{udp,tcp}{,6} : ip address format : RFC : need for /proc/net/{udp,tcp}{,6}{{n,h},{le,be}} ?
Date: Tue, 20 Jul 2021 19:39:37 +0100 [thread overview]
Message-ID: <hhr1fsvnh2.fsf@jvdspc.jvds.net> (raw)
RE:
On 20/07/2021, Randy Dunlap <rdunlap@infradead.org> wrote:
> On 7/20/21 2:14 AM, Jason Vas Dias wrote:
> ...
> Hi,
> I suggest sending your email to ndetdev@vger.kernel.org
> g'day.
Good day -
I noticed that /proc/net/{udp,tcp} files (bash expansion) - the IPv4
socket tables - contain IPv4 addresses in hex format like:
0100007F:0035
(Little-Endian IPv4 address 127.0.0.1 , Big Endian port 53)
I would have printed / expected the IPv4 address to be printed EITHER
like:
7F000001:0035 (Both Big-Endian)
OR
0100007F:3500 (Both Little-Endian)
.
It is rather idiosyncratic that Linux chooses
to print Little-Endian IPv4 addresses, but not
Little-Endian Ports , and where the other numbers
eg. (rx:tx) , (tr:tm/when) in those files are all
Big-Endian.
Perhaps a later version of Linux could either
A) Print ALL IP addresses and Ports and numbers in network
(Big Endian) byte order, or as IP dotted-quad+port strings
; OR:
B) Provide /proc/net/{udp,tcp}{,6}{n,be,h,le,ip} files
( use shell : $ echo
which print IPv4 addresses & Ports in formats:
n: network: always Big Endian
h: host: native either Little-Endian (LE) or Big Endian (BE)
be: BE - alias for 'n'
le: LE - alias for 'h' on LE platforms, else LE
ip: as dotted-decimal-quad+':'decimal-port strings, with numbers in BE.
; OR:
C) Provide /proc/net/{udp,tcp}{,6}bin memory mappable binary socket
table files
.
?
Should I raise a bug on this ?
Rather than currently letting users discover this fact
by mis-converting IP addresses / ports initially as I did at first.
Just a thought / request for comments.
One would definitely want to inform the netstat + lsof + glibc
developers before choosing option A .
Option B allows users to choose which endianess to use (for ALL numbers)
by only adding new files, not changing existing ones.
Option C would obviate the need to choose an endianess file by
just providing one new memory-mappable binary representation
of the sockets table, of size an even multiple of the page-size,
but whose reported size would be (sizeof(some_linux_ip_socket_table_struct_t) *
n_sockets_in_table). It could be provided alongside option B.
I think options B and / or C would be nice to have - I might implement an
extension to the procfs code that prints these socket tables to
do this, maybe enabled by a new experimental
'+rational-ip-socket-tables' boot option -
then at least it would be clear how the numbers in those files are
meant to be read / converted.
All the best,
Jason
next reply other threads:[~2021-07-20 18:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-20 18:39 Jason Vas Dias [this message]
-- strict thread matches above, loose matches on Subject: below --
2021-07-20 18:59 /proc/net/{udp,tcp}{,6} : ip address format : RFC : need for /proc/net/{udp,tcp}{,6}{{n,h},{le,be}} ? Jason Vas Dias
2021-07-20 22:41 ` Stephen Hemminger
2021-07-22 10:41 ` Jason Vas Dias
2021-07-20 9:14 Jason Vas Dias
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