contrib/sendmail-8.13.7/libsm/fflush.c

   1 /*
   2  * Copyright (c) 2000-2001, 2005, 2006 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  * Copyright (c) 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Chris Torek.
   9  *
  10  * By using this file, you agree to the terms and conditions set
  11  * forth in the LICENSE file which can be found at the top level of
  12  * the sendmail distribution.
  13  */
  14
  15 #include <sm/gen.h>
  16 SM_RCSID("@(#)$Id: fflush.c,v 1.45 2006/03/03 22:25:00 ca Exp $")
  17 #include <unistd.h>
  18 #include <errno.h>
  19 #include <sm/time.h>
  20 #include <signal.h>
  21 #include <fcntl.h>
  22 #include <string.h>
  23 #include <sm/io.h>
  24 #include <sm/assert.h>
  25 #include <sm/setjmp.h>
  26 #include "local.h"
  27 #include <sm/conf.h>
  28
  29 /*
  30 **  SM_IO_FLUSH -- flush the buffer for a 'fp' to the "file"
  31 **
  32 **  Flush a single file. We don't allow this function to flush
  33 **  all open files when fp==NULL any longer.
  34 **
  35 **      Parameters:
  36 **              fp -- the file pointer buffer to flush
  37 **              timeout -- time to complete the flush
  38 **
  39 **      Results:
  40 **              Failure: SM_IO_EOF and sets errno
  41 **              Success: 0 (zero)
  42 */
  43
  44 int
  45 sm_io_flush(fp, timeout)
  46         register SM_FILE_T *fp;
  47         int SM_NONVOLATILE timeout;
  48 {
  49         int fd;
  50         struct timeval to;
  51
  52         SM_REQUIRE_ISA(fp, SmFileMagic);
  53
  54         if ((fp->f_flags & (SMWR | SMRW)) == 0)
  55         {
  56                 /*
  57                 **  The file is not opened for writing, so it cannot be flushed
  58                 **  (writable means SMWR [write] or SMRW [read/write].
  59                 */
  60
  61                 errno = EBADF;
  62                 return SM_IO_EOF;
  63         }
  64
  65         SM_CONVERT_TIME(fp, fd, timeout, &to);
  66
  67         /* Now do the flush */
  68         return sm_flush(fp, (int *) &timeout);
  69 }
  70
  71 /*
  72 **  SM_FLUSH -- perform the actual flush
  73 **
  74 **  Assumes that 'fp' has been validated before this function called.
  75 **
  76 **      Parameters:
  77 **              fp -- file pointer to be flushed
  78 **              timeout -- max time allowed for flush (milliseconds)
  79 **
  80 **      Results:
  81 **              Success: 0 (zero)
  82 **              Failure: SM_IO_EOF and errno set
  83 **
  84 **      Side Effects:
  85 **              timeout will get updated with the time remaining (if any)
  86 */
  87
  88 int
  89 sm_flush(fp, timeout)
  90         register SM_FILE_T *fp;
  91         int *timeout;
  92 {
  93         register unsigned char *p;
  94         register int n, t;
  95         int fd;
  96
  97         SM_REQUIRE_ISA(fp, SmFileMagic);
  98
  99         t = fp->f_flags;
 100         if ((t & SMWR) == 0)
 101                 return 0;
 102
 103         if (t & SMSTR)
 104         {
 105                 *fp->f_p = '\0';
 106                 return 0;
 107         }
 108
 109         if ((p = fp->f_bf.smb_base) == NULL)
 110                 return 0;
 111
 112         n = fp->f_p - p;                /* write this much */
 113
 114         if ((fd = sm_io_getinfo(fp, SM_IO_WHAT_FD, NULL)) == -1)
 115         {
 116                 /* can't get an fd, likely internal 'fake' fp */
 117                 errno = 0;
 118                 fd = -1;
 119         }
 120
 121         /*
 122         **  Set these immediately to avoid problems with longjmp and to allow
 123         **  exchange buffering (via setvbuf) in user write function.
 124         */
 125
 126         fp->f_p = p;
 127         fp->f_w = t & (SMLBF|SMNBF) ? 0 : fp->f_bf.smb_size; /* implies SMFBF */
 128
 129         for (; n > 0; n -= t, p += t)
 130         {
 131                 errno = 0; /* needed to ensure EOF correctly found */
 132
 133                 /* Call the file type's write function */
 134                 t = (*fp->f_write)(fp, (char *)p, n);
 135                 if (t <= 0)
 136                 {
 137                         if (t == 0 && errno == 0)
 138                                 break; /* EOF found */
 139
 140                         if (IS_IO_ERROR(fd, t, *timeout))
 141                         {
 142                                 fp->f_flags |= SMERR;
 143
 144                                 /* errno set by fp->f_write */
 145                                 return SM_IO_EOF;
 146                         }
 147                         SM_IO_WR_TIMEOUT(fp, fd, *timeout);
 148                         t = 0;
 149                 }
 150         }
 151         return 0;
 152 }