-/* $Cambridge: exim/src/src/log.c,v 1.1 2004/10/07 10:39:01 ph10 Exp $ */
+/* $Cambridge: exim/src/src/log.c,v 1.3 2005/03/29 15:19:25 ph10 Exp $ */
/*************************************************
* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2004 */
+/* Copyright (c) University of Cambridge 1995 - 2005 */
/* See the file NOTICE for conditions of use and distribution. */
/* Functions for writing log files. The code for maintaining datestamped
/* Open was not successful: try creating the file. If this is a root process,
we must do the creating in a subprocess set to exim:exim in order to ensure
that the file is created with the right ownership. Otherwise, there can be a
-race if an exim process is trying to write to the log at the same time. The use
-of SIGUSR1 by the exiwhat utility can provoke a lot of simultaneous writing. */
+race if another Exim process is trying to write to the log at the same time.
+The use of SIGUSR1 by the exiwhat utility can provoke a lot of simultaneous
+writing. */
euid = geteuid();
_exit((create_log(buffer) < 0)? 1 : 0);
}
- /* Wait for the subprocess. If it succeeded retry the open. */
+ /* If we created a subprocess, wait for it. If it succeeded retry the open. */
- while (waitpid(pid, &status, 0) != pid);
- if (status == 0) *fd = Uopen(buffer, O_APPEND|O_WRONLY, LOG_MODE);
+ if (pid > 0)
+ {
+ while (waitpid(pid, &status, 0) != pid);
+ if (status == 0) *fd = Uopen(buffer, O_APPEND|O_WRONLY, LOG_MODE);
+ }
+
+ /* If we failed to create a subprocess, we are in a bad way. We fall through
+ with *fd still < 0, and errno set, letting the code below handle the error. */
}
/* If we now have an open file, set the close-on-exec flag and return. */