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
sm_flush(fp,timeout)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 }
153