rfc:allow_multiple_simultaneous_syslog_connections

Allow multiple simultaneous syslog connections

Introduction

This patch allows users to use multiple simultaneous syslog connections.

Currently, the openlog function does not return a resource like would do the fopen or any database connection function. That implementation limits to 1 the simultaneous number of connections possible to syslog and this is problematic when the goal is to use syslog with different log locals.

The patch changes openlog, syslog and closelog to handle a ressource which contain ident, option and facility.

Proposal

The proposed implementation should not break any current usage of syslog functions. Here is the changes :

  • add error_log_facility and error_log_ident variables to php.ini in order to defined default syslog parameters.
    • error_log_facility is set to LOG_USER by default
    • errir_log_ident is set to “php” by default
  • add main/php_syslog.c file with :
    • Add 3 variable in the struct _php_core_globals to keep trace of syslog options over the php_syslog2() calls.
    • php_openlog: save ident, facility and option in its global context before calling openlog.
    • php_closelog: clear global context before calling closelog
    • php_syslog_get_ident: returns the ident global context
    • php_syslog_get_facility: returns the facility global context
    • php_syslog_get_option: returns the option global context
    • php_syslog2() is quite the same as php_syslog with ident/facility/option arguments added. Thoses are compared to the syslog global context, and openlog is called if they don't match.
    • php_syslog remains #defined to syslog
  • in main/main.c:
    • if error_log is set to “syslog”, call php_syslog2() with error_log_ident/facility instead of php_syslog()
  • in ext/standard/syslog.c
    • now openlog() returns a ressource which contains ident/option/facility
    • now syslog() and closelog() takes an optional ressource parameter (returned from openlog) at the last position
    • use php_syslog2,php_openlog and php_closelog
  • in sapi/milter/php_milter.c
    • use php_syslog2 in place of previous openlog/syslog

Example

<?php
  syslog(LOG_ERR, "test 1 wihout calling openlog");
  /*
    ident is default aka "php"
    Jul 23 05:20:22 hostname php: test 1 wihout calling openlog
  */
 
  $r1 = openlog("ident#1", LOG_PID, LOG_SYSLOG);
  $r2 = openlog("ident#2", LOG_PID, LOG_SYSLOG);
 
  syslog(LOG_ERR, "test on #1", $r1);
  /*
    use $r1, so ident is now "ident#1"
    Jul 23 05:20:22 hostname ident#1[24144]: test on #1
  */
 
  syslog(LOG_ERR, "test on ressource #2", $r2);
  /*
    use $r2, so ident is now "ident#2"
    Jul 23 05:20:22 hostname ident#2[24144]: test on #2
  */
 
  closelog($r1);
  closelog($r2);
 
  syslog(LOG_ERR, "test 2 without openlog");
  /*
    as $r1 and $r2 have been closed, ident has been reset to default aka "php"
    Jul 23 05:20:22 hostname php: test 2 wihout calling openlog
  */
 
  openlog("ident#0", LOG_PID, LOG_SYSLOG);
  syslog(LOG_ERR, "test 3 with openlog() but without ressource");
  /*
    openlog has been called, so ident not the default until closelog() call
    Jul 23 05:20:22 hostname php[24144]: test 3 with openlog() but without ressource
  */
  closelog();
  syslog(LOG_ERR, "test 4 without calling openlog");
  /*
    closelog() has been called, ident has been reset to default aka "php"
    Jul 23 05:20:22 hostname php: test 4 wihout calling openlog
  */
?>

Patch

  • The source patch can be found with the ticket: https://bugs.php.net/bug.php?id=51118
  • The patch has not been tested on win32 yet and it needs small adjustments.
  • The documentation has not been patched yet. (waiting for approval)
  • Tests have not been done/updated yet. (waiting for approval)

References

Changelog

  • 2011/07/05 Draft
  • 2011/07/05 first revision
  • 2011/10/08 marked as dead
rfc/allow_multiple_simultaneous_syslog_connections.txt · Last modified: 2011/10/08 16:17 by fat