[PATCH libxtrans v3.1] Enable systemd socket activation

[Łukasz Stelmach]

It was <2013-07-12 pią 18:08>, when walter harms wrote:
> Am 12.07.2013 17:17, schrieb Łukasz Stelmach:
>> Receive file descriptors of open sockets from systemd instead of
>> creating them.
>> 
>> Signed-off-by: Łukasz Stelmach <l.stelmach at samsung.com>
>> Cc: Kyungmin Park <kyungmin.park at samsung.com>
>> Cc: MyungJoo Ham <myungjoo.ham at samsung.com>
>> Cc: Piort Bereza <p.bereza at samsung.com>
>> Cc: Karol Lewandowski <k.lewandowsk at samsung.com>
>> Cc: Lennart Poettering <lennart at poettering.net>
>> Cc: Zbigniew Jędrzejewski-Szmek <zbyszek at in.waw.pl>
>> Cc: Peter Hutterer <peter.hutterer at who-t.net>
>> Cc: walter harms <wharms at bfs.de>
>> Cc: Alan Coopersmith <alan.coopersmith at oracle.com>
>> ---
>>  Xtrans.c |   78 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 77 insertions(+), 1 deletion(-)
>> 
>> diff --git a/Xtrans.c b/Xtrans.c
>> index 5860f3a..891edb4 100644
>> --- a/Xtrans.c
>> +++ b/Xtrans.c
>> @@ -48,6 +48,9 @@ from The Open Group.
>>   */
>>  
>>  #include <ctype.h>
>> +#ifdef HAVE_SYSTEMD
>> +#include <systemd/sd-daemon.h>
>> +#endif
>>  
>>  /*
>>   * The transport table contains a definition for every transport (protocol)
>> @@ -1037,6 +1040,75 @@ complete_network_count (void)
>>  }
>>  
>>  
>> +static int
>> +receive_listening_fds(char* port, XtransConnInfo* temp_ciptrs, int* count_ret)
>> +
>> +{
>> +#ifdef HAVE_SYSTEMD
>> +    XtransConnInfo	ciptr;
>> +    char buffer[8];
>> +    int  systemd_listen_fds, i;
>> +
>> +    systemd_listen_fds = sd_listen_fds(1);
>> +    if (systemd_listen_fds < 0)
>> +    {
>> +	return -1;
>> +    }
>
> sd_listen_fds(1) can never be 0 ?

Of course it can. It means no file descriptors have been passed (or they
have been passed incorectly)[1] and as one might expect it causes the
programme to jump directly to the "return 0" at the end of the function.

>> +    else if (systemd_listen_fds > 0)
>> +    {
>> +	snprintf(buffer, sizeof(buffer), ":%s", port);
>
> sorry, i feel stupid but i still can not see any use of buffer.
> The others seem to use it for debugging output but not in this function.

Indeed. You are right, I've fixed it.

[1] http://www.freedesktop.org/software/systemd/man/sd_listen_fds.html
-- 
Łukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics