external/ibm-public/postfix/dist/src/global/mbox_conf.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      mbox_conf 3
   6 /* SUMMARY
   7 /*      mailbox lock configuration
   8 /* SYNOPSIS
   9 /*      #include <mbox_conf.h>
  10 /*
  11 /*      int     mbox_lock_mask(string)
  12 /*      const char *string;
  13 /*
  14 /*      ARGV    *mbox_lock_names()
  15 /* DESCRIPTION
  16 /*      The functions in this module translate between external
  17 /*      mailbox locking method names and internal representations.
  18 /*
  19 /*      mbox_lock_mask() translates a string with locking method names
  20 /*      into a bit mask. Names are separated by comma or whitespace.
  21 /*      The following gives the method names and corresponding bit
  22 /*      mask value:
  23 /* .IP "flock (MBOX_FLOCK_LOCK)"
  24 /*      Use flock() style lock after opening the file. This is the mailbox
  25 /*      locking method traditionally used on BSD-ish systems (including
  26 /*      Ultrix and SunOS). It is not suitable for remote file systems.
  27 /* .IP "fcntl (MBOX_FCNTL_LOCK)"
  28 /*      Use fcntl() style lock after opening the file. This is the mailbox
  29 /*      locking method on System-V-ish systems (Solaris, AIX, IRIX, HP-UX).
  30 /*      This method is supposed to work for remote systems, but often
  31 /*      has problems.
  32 /* .IP "dotlock (MBOX_DOT_LOCK)"
  33 /*      Create a lock file with the name \fIfilename\fB.lock\fR. This
  34 /*      method pre-dates kernel locks. This works with remote file systems,
  35 /*      modulo cache coherency problems.
  36 /* .PP
  37 /*      mbox_lock_names() returns an array with the names of available
  38 /*      mailbox locking methods. The result should be given to argv_free().
  39 /* DIAGNOSTICS
  40 /*      Fatal errors: undefined locking method name.
  41 /* LICENSE
  42 /* .ad
  43 /* .fi
  44 /*      The Secure Mailer license must be distributed with this software.
  45 /* AUTHOR(S)
  46 /*      Wietse Venema
  47 /*      IBM T.J. Watson Research
  48 /*      P.O. Box 704
  49 /*      Yorktown Heights, NY 10598, USA
  50 /*--*/
  51
  52 /* System library. */
  53
  54 #include <sys_defs.h>
  55
  56 /* Utility library. */
  57
  58 #include <name_mask.h>
  59 #include <argv.h>
  60
  61 /* Global library. */
  62
  63 #include <mail_params.h>
  64 #include <mbox_conf.h>
  65
  66  /*
  67   * The table with available mailbox locking methods. Some systems have
  68   * flock() locks; all POSIX-compatible systems have fcntl() locks. Even
  69   * though some systems do not use dotlock files by default (4.4BSD), such
  70   * locks can be necessary when accessing mailbox files over NFS.
  71   */
  72 static const NAME_MASK mbox_mask[] = {
  73 #ifdef HAS_FLOCK_LOCK
  74     "flock", MBOX_FLOCK_LOCK,
  75 #endif
  76 #ifdef HAS_FCNTL_LOCK
  77     "fcntl", MBOX_FCNTL_LOCK,
  78 #endif
  79     "dotlock", MBOX_DOT_LOCK,
  80     0,
  81 };
  82
  83 /* mbox_lock_mask - translate mailbox lock names to bit mask */
  84
  85 int     mbox_lock_mask(const char *string)
  86 {
  87     return (name_mask(VAR_MAILBOX_LOCK, mbox_mask, string));
  88 }
  89
  90 /* mbox_lock_names - return available mailbox lock method names */
  91
  92 ARGV   *mbox_lock_names(void)
  93 {
  94     const NAME_MASK *np;
  95     ARGV   *argv;
  96
  97     argv = argv_alloc(2);
  98     for (np = mbox_mask; np->name != 0; np++)
  99         argv_add(argv, np->name, ARGV_END);
 100     argv_terminate(argv);
 101     return (argv);
 102 }