[PATCH libxtrans v3.1] Enable systemd socket activation

[walter harms]

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 ?


> +    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.

re,
 wh

ntl: thx for making this a single function it is much more easy to review now.

> +	for (i = 0; i < systemd_listen_fds && *count_ret < NUMTRANS; i++)
> +	{
> +	    struct sockaddr_storage a;
> +	    int ti;
> +	    const char* tn;
> +	    socklen_t al;
> +
> +	    al = sizeof(a);
> +	    if (getsockname(i + SD_LISTEN_FDS_START, (struct sockaddr*)&a, &al) < 0)
> +		return -1;
> +
> +	    switch (a.ss_family)
> +	    {
> +	    case AF_UNIX:
> +		ti = TRANS_SOCKET_UNIX_INDEX;
> +		if (*((struct sockaddr_un*)&a)->sun_path == '\0' &&
> +		    al > sizeof(sa_family_t))
> +		    tn = "local";
> +		else
> +		    tn = "unix";
> +		break;
> +	    case AF_INET:
> +		ti = TRANS_SOCKET_INET_INDEX;
> +		tn = "inet";
> +		break;
> +#if defined(IPv6) && defined(AF_INET6)
> +	    case AF_INET6:
> +		ti = TRANS_SOCKET_INET6_INDEX;
> +		tn = "inet6";
> +		break;
> +#endif /* IPv6 */
> +	    default:
> +		return -1;
> +	    }
> +
> +	    if ((ciptr = TRANS(ReopenCOTSServer)(ti, i + SD_LISTEN_FDS_START,
> +						 port))==NULL)
> +		prmsg (1, "MakeAllCOTSServerListeners:"
> +		       "Got NULL while trying to reopen socket received from systemd.\n");
> +	    else
> +	    {
> +		prmsg (5, "MakeAllCOTSServerListeners: received listener for %s, %d\n",
> +		       tn, ciptr->fd);
> +		temp_ciptrs[(*count_ret)++] = ciptr;
> +		TRANS(Received)(tn);
> +	    }
> +	}
> +    }
> +#endif /* HAVE_SYSTEMD */
> +    return 0;
> +}
> +
>  #ifdef XQUARTZ_EXPORTS_LAUNCHD_FD
>  extern int xquartz_launchd_fd;
>  #endif
> @@ -1069,12 +1141,16 @@ TRANS(MakeAllCOTSServerListeners) (char *port, int *partial, int *count_ret,
>      }
>  #endif
>  
> +    if (receive_listening_fds(port, temp_ciptrs, count_ret) < 0)
> +	return -1;
> +
>      for (i = 0; i < NUMTRANS; i++)
>      {
>  	Xtransport *trans = Xtransports[i].transport;
>  	unsigned int flags = 0;
>  
> -	if (trans->flags&TRANS_ALIAS || trans->flags&TRANS_NOLISTEN)
> +	if (trans->flags&TRANS_ALIAS || trans->flags&TRANS_NOLISTEN ||
> +	    trans->flags&TRANS_RECEIVED)
>  	    continue;
>  
>  	snprintf(buffer, sizeof(buffer), "%s/:%s",