[OpenWrt-Devel] python ctypes.util.find_library cannot find libc
Alexandru Ardelean
ardeleanalex at gmail.com
Wed Jan 18 11:05:10 EST 2017
Hey,
So, if you try on the system.
echo /usr/sbin/modprobe > /proc/sys/kernel/modprobe
Does it work ? I mean to just import iptc ?
It worked for me, but I tried on a LEDE system (x86_64), which I'm
hoping may be similar to OpenWrt.
For me, the part that interests me the most, is if this is a bug
within Python [ since I maintain it ], and it runs on both LEDE &
OpenWrt.
Will try to spin up a OpenWrt [just cloned trunk from Github ].
And I'll try to reproduce.
For reference ; Python is version 2.7.13
It's from here: https://github.com/openwrt/packages
I could not find hash 5ba298c in OpenWrt [
https://github.com/openwrt/openwrt ] nor in packages [ link above ].
Will come back with findings for OpenWrt.
In the meantime, I will see about proposing a solution for updating
/proc/sys/kernel/modprobe correctly for both LEDE & OpenWrt.
Thanks
Alex
On Wed, Jan 18, 2017 at 4:38 PM, Andrew McConachie <andrew at depht.com> wrote:
> Hi 郭涛 and Alexandru,
>
> ldconfig depends on using eglibc to fulfill libc requirement.
>
> Symbol: PACKAGE_ldconfig [=n]
> Type : tristate
> Prompt: ldconfig............................... Shared library path
> configuration
> Location:
> (3) -> Utilities
> Defined at tmp/.config-package.in:82365
> Depends on: !USE_MUSL [=y]
>
> If we make python depend on ldconfig, then are we saying python cannot be
> used with MUSL libc? I don't know what the default libc is for OpenWRT or
> whether one is considered experimental more than the other. But this is
> something to consider.
>
> Thanks,
> Andrew
>
>
> On 1/18/17 03:32, 郭涛 wrote:
>>
>> Hi Andrew & Alexandru
>>
>> Forget the patch in prev mail, use attached patch instead.
>>
>> To use ctypes.util.find_library, you need one of gcc, ldconfig or
>> objdump. I suggest you use ldconfig
>>
>> After install ldconfig, run ldconfig first to update cache
>> then run ldconfig -p to show all of your libraries
>> in my case, it shows:
>>
>> 195 libs found in cache `/etc/ld.so.cache' (version 1.7.0)
>> uhttpd_tls.so (libc0) => /usr/lib/uhttpd_tls.so
>> rclibrary.so (libc0) => /usr/lib/rclibrary.so
>> libz.so.1 (libc0) => /usr/lib/libz.so.1
>> libz.so (libc0) => /usr/lib/libz.so
>> libyaml-0.so.2 (libc0) => /usr/lib/libyaml-0.so.2
>> ......
>>
>> All libraries are libc0, that's why ctypes.util.find_library does not
>> work on my platform
>>
>> You need to run 'uname -m' to get your matchine name and run 'ldconfig
>> -p' to get library type.
>> Atter all, append '$machine' : '$type' to mach_map list in
>> ctypes/util.py and try find_library('pthread')
>>
>>
>>>>> from ctypes.util import find_library
>>>>>
>>>>> find_library('pthread')
>>
>> 'libpthread.so.0'
>>
>>
>>
>>
>>
>>
>> 2017-01-17 22:22 GMT+08:00 Alexandru Ardelean <ardeleanalex at gmail.com>:
>>>
>>> Will give it a try.
>>>
>>> On Mon, Jan 16, 2017 at 9:41 PM, Andrew McConachie <andrew at depht.com>
>>> wrote:
>>>>
>>>> Hi Alexandru and 郭涛,
>>>>
>>>> Attached is the Makefile I made for python-iptables. I can work around
>>>> this
>>>> by hardwiring library locations in the source of python-iptables, but
>>>> I'd
>>>> rather do it the correct way. To reproduce this build an OpenWrt system
>>>> with
>>>> this Makefile and then just create a simple Python script with 'import
>>>> iptc'.
>>>>
>>>> I am cloning OpenWrt from Github and running make menuconfig;make to
>>>> build
>>>> everything. My Github version is about 6 days old with the last commit
>>>> at
>>>> 5ba298c.
>>>>
>>>> I also found that /proc/sys/kernel/modprobe contains /sbin/modprobe,
>>>> while
>>>> the modprobe binary is at /usr/sbin/modprobe. According to the Debian
>>>> man
>>>> page on proc(5), /proc/sys/kernel/modprobe should point to the modprobe
>>>> binary. Googling about seems also to suggest that this file should
>>>> contain
>>>> the location of the modprobe binary. So I would say this is also a bug.
>>>>
>>>> Thanks!
>>>> --Andrew
>>>>
>>>>
>>>> On 1/16/17 07:23, Alexandru Ardelean wrote:
>>>>>
>>>>> Hey Andrew & 郭涛
>>>>>
>>>>> Sorry I did not answer sooner.
>>>>>
>>>>> @Andrew: do you have a Makefile for the python-iptables packages ?
>>>>> I'd like to try to build it and see the issue. Or, are you just using
>>>>> that .py file ?
>>>>> Can you give a bit more input on which Python version you're using,
>>>>> and which OpenWrt version?
>>>>>
>>>>> If the issue is still present in the current packages trunk, I'd like
>>>>> to
>>>>> fix it.
>>>>> And if 郭涛's fix works, we can apply it to trunk.
>>>>>
>>>>> Thanks
>>>>> Alex
>>>>>
>>>>>
>>>>> On Mon, Jan 16, 2017 at 6:23 AM, 郭涛 <guotao945 at gmail.com> wrote:
>>>>>>
>>>>>> I also meet this issue.
>>>>>> I fixed it using below change
>>>>>>
>>>>>>
>>>>>>
>>>>>> https://github.com/gt945/Netgear-D7800-Openwrt-Packages/commit/fab71ca0ebf36d5f7b495b96f14d459e794b7224
>>>>>>
>>>>>>
>>>>>> 2017-01-13 0:43 GMT+08:00 Andrew McConachie <andrew at depht.com>:
>>>>>>>
>>>>>>> Hi OpenWRT Devs,
>>>>>>>
>>>>>>> I'm building an OpenWRT package for python-iptables for a project I'm
>>>>>>> working on and getting this error message when attempting to use it.
>>>>>>>
>>>>>>> import iptc
>>>>>>> File "/usr/lib/python2.7/site-packages/iptc/__init__.py", line
>>>>>>> 10, in
>>>>>>> <module>
>>>>>>> from ip4tc import (is_table_available, Table, Chain, Rule,
>>>>>>> Match,
>>>>>>> Target,
>>>>>>> File "/usr/lib/python2.7/site-packages/iptc/ip4tc.py", line 13,
>>>>>>> in
>>>>>>> <module>
>>>>>>> from xtables import (XT_INV_PROTO, NFPROTO_IPV4, XTablesError,
>>>>>>> xtables,
>>>>>>> File "/usr/lib/python2.7/site-packages/iptc/xtables.py", line
>>>>>>> 677, in
>>>>>>> <module>
>>>>>>> _optind = ct.c_long.in_dll(_libc, "optind")
>>>>>>> AttributeError: 'NoneType' object has no attribute '_handle'
>>>>>>>
>>>>>>> You can view xtables.py here if you're curious.
>>>>>>> https://github.com/ldx/python-iptables/blob/master/iptc/xtables.py
>>>>>>>
>>>>>>> The problem is that my python-iptables package cannot find libc
>>>>>>> functions
>>>>>>> using ctypes.util.find_library(). I've tried building OpenWRT using
>>>>>>> both
>>>>>>> musl and eglibc but neither work. I've also tried building OpenWRT
>>>>>>> with
>>>>>>> objdump and ldconfig. When I include ldconfig via 'make menuconfig'
>>>>>>> it
>>>>>>> doesn't actually populate my OpenWRT image with an ldconfig binary.
>>>>>>> Maybe
>>>>>>> this is the problem?
>>>>>>>
>>>>>>> This bug report looks similar to my problem, but it's about MIPS and
>>>>>>> marked
>>>>>>> as closed.
>>>>>>> https://dev.openwrt.org/ticket/20123
>>>>>>>
>>>>>>> Any help or pointers would be much appreciated.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Andrew
>>>>>>> _______________________________________________
>>>>>>> openwrt-devel mailing list
>>>>>>> openwrt-devel at lists.openwrt.org
>>>>>>> https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
>>>>>>
>>>>>> _______________________________________________
>>>>>> openwrt-devel mailing list
>>>>>> openwrt-devel at lists.openwrt.org
>>>>>> https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
>>>>
>>>>
>
_______________________________________________
openwrt-devel mailing list
openwrt-devel at lists.openwrt.org
https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
More information about the openwrt-devel
mailing list