fflush.c revision 261363 
1266987Smarkj/*
2266987Smarkj * Copyright (c) 2000-2001, 2005, 2006 Proofpoint, Inc. and its suppliers.
3266987Smarkj *      All rights reserved.
4266987Smarkj * Copyright (c) 1990, 1993
5266987Smarkj *	The Regents of the University of California.  All rights reserved.
6266987Smarkj *
7266987Smarkj * This code is derived from software contributed to Berkeley by
8266987Smarkj * Chris Torek.
9266987Smarkj *
10266987Smarkj * By using this file, you agree to the terms and conditions set
11266987Smarkj * forth in the LICENSE file which can be found at the top level of
12266987Smarkj * the sendmail distribution.
13266987Smarkj */
14266987Smarkj
15266987Smarkj#include <sm/gen.h>
16266987SmarkjSM_RCSID("@(#)$Id: fflush.c,v 1.46 2013/11/22 20:51:42 ca Exp $")
17266987Smarkj#include <unistd.h>
18266987Smarkj#include <errno.h>
19266987Smarkj#include <sm/time.h>
20266987Smarkj#include <signal.h>
21266987Smarkj#include <fcntl.h>
22266987Smarkj#include <string.h>
23266987Smarkj#include <sm/io.h>
24266987Smarkj#include <sm/assert.h>
25266987Smarkj#include <sm/setjmp.h>
26266987Smarkj#include "local.h"
27266987Smarkj#include <sm/conf.h>
28266987Smarkj
29266987Smarkj/*
30266987Smarkj**  SM_IO_FLUSH -- flush the buffer for a 'fp' to the "file"
31266987Smarkj**
32266987Smarkj**  Flush a single file. We don't allow this function to flush
33266987Smarkj**  all open files when fp==NULL any longer.
34266987Smarkj**
35266987Smarkj**	Parameters:
36266987Smarkj**		fp -- the file pointer buffer to flush
37266987Smarkj**		timeout -- time to complete the flush
38266987Smarkj**
39266987Smarkj**	Results:
40266987Smarkj**		Failure: SM_IO_EOF and sets errno
41266987Smarkj**		Success: 0 (zero)
42266987Smarkj*/
43266987Smarkj
44266987Smarkjint
45266987Smarkjsm_io_flush(fp, timeout)
46266987Smarkj	register SM_FILE_T *fp;
47266987Smarkj	int SM_NONVOLATILE timeout;
48266987Smarkj{
49266987Smarkj	int fd;
50266987Smarkj	struct timeval to;
51266987Smarkj
52266987Smarkj	SM_REQUIRE_ISA(fp, SmFileMagic);
53266987Smarkj
54266987Smarkj	if ((fp->f_flags & (SMWR | SMRW)) == 0)
55266987Smarkj	{
56266987Smarkj		/*
57266987Smarkj		**  The file is not opened for writing, so it cannot be flushed
58266987Smarkj		**  (writable means SMWR [write] or SMRW [read/write].
59266987Smarkj		*/
60266987Smarkj
61266987Smarkj		errno = EBADF;
62266987Smarkj		return SM_IO_EOF;
63266987Smarkj	}
64266987Smarkj
65266987Smarkj	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
88int
89sm_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