external/ibm-public/postfix/dist/src/util/file_limit.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      file_limit 3
   6 /* SUMMARY
   7 /*      limit the file size
   8 /* SYNOPSIS
   9 /*      #include <iostuff.h>
  10 /*
  11 /*      off_t   get_file_limit()
  12 /*
  13 /*      void    set_file_limit(limit)
  14 /*      off_t   limit;
  15 /* DESCRIPTION
  16 /*      This module manipulates the process-wide file size limit.
  17 /*      The limit is specified in bytes.
  18 /*
  19 /*      get_file_limit() looks up the process-wide file size limit.
  20 /*
  21 /*      set_file_limit() sets the process-wide file size limit to
  22 /*      \fIlimit\fR.
  23 /* DIAGNOSTICS
  24 /*      All errors are fatal.
  25 /* SEE ALSO
  26 /*      setrlimit(2)
  27 /*      ulimit(2)
  28 /* LICENSE
  29 /* .ad
  30 /* .fi
  31 /*      The Secure Mailer license must be distributed with this software.
  32 /* AUTHOR(S)
  33 /*      Wietse Venema
  34 /*      IBM T.J. Watson Research
  35 /*      P.O. Box 704
  36 /*      Yorktown Heights, NY 10598, USA
  37 /*--*/
  38
  39 /* System library. */
  40
  41 #include <sys_defs.h>
  42 #ifdef USE_ULIMIT
  43 #include <ulimit.h>
  44 #else
  45 #include <sys/time.h>
  46 #include <sys/resource.h>
  47 #include <signal.h>
  48 #endif
  49 #include <limits.h>
  50
  51 /* Utility library. */
  52
  53 #include <msg.h>
  54 #include <iostuff.h>
  55
  56 #define ULIMIT_BLOCK_SIZE       512
  57
  58 /* get_file_limit - get process-wide file size limit */
  59
  60 off_t   get_file_limit(void)
  61 {
  62     off_t   limit;
  63
  64 #ifdef USE_ULIMIT
  65     if ((limit = ulimit(UL_GETFSIZE, 0)) < 0)
  66         msg_fatal("ulimit: %m");
  67     if (limit > OFF_T_MAX / ULIMIT_BLOCK_SIZE)
  68         limit = OFF_T_MAX / ULIMIT_BLOCK_SIZE;
  69     return (limit * ULIMIT_BLOCK_SIZE);
  70 #else
  71     struct rlimit rlim;
  72
  73     if (getrlimit(RLIMIT_FSIZE, &rlim) < 0)
  74         msg_fatal("getrlimit: %m");
  75     limit = rlim.rlim_cur;
  76     return (limit < 0 ? OFF_T_MAX : rlim.rlim_cur);
  77 #endif                                          /* USE_ULIMIT */
  78 }
  79
  80 /* set_file_limit - process-wide file size limit */
  81
  82 void    set_file_limit(off_t limit)
  83 {
  84 #ifdef USE_ULIMIT
  85     if (ulimit(UL_SETFSIZE, limit / ULIMIT_BLOCK_SIZE) < 0)
  86         msg_fatal("ulimit: %m");
  87 #else
  88     struct rlimit rlim;
  89
  90     rlim.rlim_cur = rlim.rlim_max = limit;
  91     if (setrlimit(RLIMIT_FSIZE, &rlim) < 0)
  92         msg_fatal("setrlimit: %m");
  93 #ifdef SIGXFSZ
  94     if (signal(SIGXFSZ, SIG_IGN) == SIG_ERR)
  95         msg_fatal("signal(SIGXFSZ,SIG_IGN): %m");
  96 #endif
  97 #endif                                          /* USE_ULIMIT */
  98 }