From b7c15c31519dc44c1f691e0466badd556ffe9423 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:18:56 +0200 Subject: Adding upstream version 3.7.10. Signed-off-by: Daniel Baumann --- src/global/deliver_flock.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 src/global/deliver_flock.c (limited to 'src/global/deliver_flock.c') diff --git a/src/global/deliver_flock.c b/src/global/deliver_flock.c new file mode 100644 index 0000000..35a6bcb --- /dev/null +++ b/src/global/deliver_flock.c @@ -0,0 +1,82 @@ +/*++ +/* NAME +/* deliver_flock 3 +/* SUMMARY +/* lock open file for mail delivery +/* SYNOPSIS +/* #include +/* +/* int deliver_flock(fd, lock_style, why) +/* int fd; +/* int lock_style; +/* VSTRING *why; +/* DESCRIPTION +/* deliver_flock() sets one exclusive kernel lock on an open file, +/* for example in order to deliver mail. +/* It performs several non-blocking attempts to acquire an exclusive +/* lock before giving up. +/* +/* Arguments: +/* .IP fd +/* A file descriptor that is associated with an open file. +/* .IP lock_style +/* A locking style defined in myflock(3). +/* .IP why +/* A null pointer, or storage for diagnostics. +/* DIAGNOSTICS +/* deliver_flock() returns -1 in case of problems, 0 in case +/* of success. The reason for failure is returned via the \fIwhy\fR +/* parameter. +/* CONFIGURATION PARAMETERS +/* deliver_lock_attempts, number of locking attempts +/* deliver_lock_delay, time in seconds between attempts +/* sun_mailtool_compatibility, disable kernel locking +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System library. */ + +#include "sys_defs.h" +#include + +/* Utility library. */ + +#include +#include +#include + +/* Global library. */ + +#include "mail_params.h" +#include "deliver_flock.h" + +/* Application-specific. */ + +#define MILLION 1000000 + +/* deliver_flock - lock open file for mail delivery */ + +int deliver_flock(int fd, int lock_style, VSTRING *why) +{ + int i; + + for (i = 1; /* void */ ; i++) { + if (myflock(fd, lock_style, + MYFLOCK_OP_EXCLUSIVE | MYFLOCK_OP_NOWAIT) == 0) + return (0); + if (i >= var_flock_tries) + break; + rand_sleep(var_flock_delay * MILLION, var_flock_delay * MILLION / 2); + } + if (why) + vstring_sprintf(why, "unable to lock for exclusive access: %m"); + return (-1); +} -- cgit v1.2.3