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 #pragma ident "%Z%%M% %I% %E% SMI"
16
17 #include <sm/gen.h>
18 SM_RCSID("@(#)$Id: fflush.c,v 1.45 2006/03/03 22:25:00 ca Exp $")
19 #include <unistd.h>
20 #include <errno.h>
21 #include <sm/time.h>
22 #include <signal.h>
23 #include <fcntl.h>
24 #include <string.h>
25 #include <sm/io.h>
26 #include <sm/assert.h>
27 #include <sm/setjmp.h>
28 #include "local.h"
29 #include <sm/conf.h>
30
31 /*
32 ** SM_IO_FLUSH -- flush the buffer for a 'fp' to the "file"
33 **
34 ** Flush a single file. We don't allow this function to flush
35 ** all open files when fp==NULL any longer.
36 **
37 ** Parameters:
38 ** fp -- the file pointer buffer to flush
39 ** timeout -- time to complete the flush
40 **
41 ** Results:
42 ** Failure: SM_IO_EOF and sets errno
43 ** Success: 0 (zero)
44 */
45
46 int
47 sm_io_flush(fp, timeout)
48 register SM_FILE_T *fp;
49 int SM_NONVOLATILE timeout;
50 {
51 int fd;
52 struct timeval to;
53
54 SM_REQUIRE_ISA(fp, SmFileMagic);
55
56 if ((fp->f_flags & (SMWR | SMRW)) == 0)
57 {
58 /*
59 ** The file is not opened for writing, so it cannot be flushed
60 ** (writable means SMWR [write] or SMRW [read/write].
61 */
62
63 errno = EBADF;
64 return SM_IO_EOF;
65 }
66
67 SM_CONVERT_TIME(fp, fd, timeout, &to);
68
69 /* Now do the flush */
70 return sm_flush(fp, (int *) &timeout);
71 }
72
73 /*
74 ** SM_FLUSH -- perform the actual flush
75 **
76 ** Assumes that 'fp' has been validated before this function called.
77 **
78 ** Parameters:
79 ** fp -- file pointer to be flushed
80 ** timeout -- max time allowed for flush (milliseconds)
81 **
82 ** Results:
83 ** Success: 0 (zero)
84 ** Failure: SM_IO_EOF and errno set
85 **
86 ** Side Effects:
87 ** timeout will get updated with the time remaining (if any)
88 */
89
90 int
sm_flush(fp,timeout)91 sm_flush(fp, timeout)
92 register SM_FILE_T *fp;
93 int *timeout;
94 {
95 register unsigned char *p;
96 register int n, t;
97 int fd;
98
99 SM_REQUIRE_ISA(fp, SmFileMagic);
100
101 t = fp->f_flags;
102 if ((t & SMWR) == 0)
103 return 0;
104
105 if (t & SMSTR)
106 {
107 *fp->f_p = '\0';
108 return 0;
109 }
110
111 if ((p = fp->f_bf.smb_base) == NULL)
112 return 0;
113
114 n = fp->f_p - p; /* write this much */
115
116 if ((fd = sm_io_getinfo(fp, SM_IO_WHAT_FD, NULL)) == -1)
117 {
118 /* can't get an fd, likely internal 'fake' fp */
119 errno = 0;
120 fd = -1;
121 }
122
123 /*
124 ** Set these immediately to avoid problems with longjmp and to allow
125 ** exchange buffering (via setvbuf) in user write function.
126 */
127
128 fp->f_p = p;
129 fp->f_w = t & (SMLBF|SMNBF) ? 0 : fp->f_bf.smb_size; /* implies SMFBF */
130
131 for (; n > 0; n -= t, p += t)
132 {
133 errno = 0; /* needed to ensure EOF correctly found */
134
135 /* Call the file type's write function */
136 t = (*fp->f_write)(fp, (char *)p, n);
137 if (t <= 0)
138 {
139 if (t == 0 && errno == 0)
140 break; /* EOF found */
141
142 if (IS_IO_ERROR(fd, t, *timeout))
143 {
144 fp->f_flags |= SMERR;
145
146 /* errno set by fp->f_write */
147 return SM_IO_EOF;
148 }
149 SM_IO_WR_TIMEOUT(fp, fd, *timeout);
150 t = 0;
151 }
152 }
153 return 0;
154 }
155