xref: /illumos-gate/usr/src/lib/libc/port/stdio/_endopen.c (revision 66582b606a8194f7f3ba5b3a3a6dca5b0d346361)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /* Copyright (c) 2013 OmniTI Computer Consulting, Inc. All rights reserved. */
31 
32 /*
33  *	This routine is a special case, in that it is aware of
34  *	both small and large file interfaces. It must be built
35  *	in the small compilation environment.
36  */
37 
38 #include "lint.h"
39 #include "file64.h"
40 #include <mtlib.h>
41 #include <sys/types.h>
42 #include <stdio.h>
43 #include <fcntl.h>
44 #include <unistd.h>
45 #include <limits.h>
46 #include <thread.h>
47 #include <synch.h>
48 #include "stdiom.h"
49 #include <errno.h>
50 
51 /*
52  * open UNIX file name, associate with iop
53  */
54 
55 FILE *
56 _endopen(const char *name, const char *type, FILE *iop, int largefile)
57 {
58 	int oflag, fd, fflag, eflag, plusflag, xflag;
59 	const char *echr;
60 
61 	if (iop == NULL)
62 		return (NULL);
63 	switch (type[0]) {
64 	default:
65 		errno = EINVAL;
66 		return (NULL);
67 	case 'r':
68 		oflag = O_RDONLY;
69 		fflag = _IOREAD;
70 		break;
71 	case 'w':
72 		oflag = O_WRONLY | O_TRUNC | O_CREAT;
73 		fflag = _IOWRT;
74 		break;
75 	case 'a':
76 		oflag = O_WRONLY | O_APPEND | O_CREAT;
77 		fflag = _IOWRT;
78 		break;
79 	}
80 
81 	plusflag = 0;
82 	eflag = 0;
83 	xflag = 0;
84 	for (echr = type + 1; *echr != '\0'; echr++) {
85 		switch (*echr) {
86 		/* UNIX ignores 'b' and treats text and binary the same */
87 		default:
88 			break;
89 		case '+':
90 			plusflag = 1;
91 			break;
92 		case 'e':
93 			eflag = 1;
94 			break;
95 		case 'x':
96 			xflag = 1;
97 			break;
98 		}
99 	}
100 	if (eflag) {
101 		/* Subsequent to a mode flag, 'e' indicates O_CLOEXEC */
102 		oflag = oflag | O_CLOEXEC;
103 	}
104 	if (plusflag) {
105 		oflag = (oflag & ~(O_RDONLY | O_WRONLY)) | O_RDWR;
106 		fflag = _IORW;
107 	}
108 	if (xflag) {
109 		oflag |= O_EXCL;
110 	}
111 
112 	/* select small or large file open based on flag */
113 	if (largefile) {
114 		fd = open64(name, oflag, 0666);
115 	} else {
116 		fd = open(name, oflag, 0666);
117 	}
118 	if (fd < 0)
119 		return (NULL);
120 
121 	/* As long as we make sure _flag stays != 0, we don't need to lock */
122 #ifdef	_LP64
123 	iop->_file = fd;
124 	iop->_flag = (iop->_flag & ~0377) | fflag;
125 #else
126 	if (fd <= _FILE_FD_MAX) {
127 		SET_FILE(iop, fd);
128 	} else if (_file_set(iop, fd, type) != 0) {
129 		/* errno set in _file_set() */
130 		(void) close(fd);
131 		return (NULL);
132 	}
133 	iop->_flag = fflag;
134 #endif	/*	_LP64	*/
135 
136 	if (oflag == (O_WRONLY | O_APPEND | O_CREAT)) {	/* type == "a" */
137 		if (lseek64(fd, (off64_t)0, SEEK_END) < (off64_t)0) {
138 			(void) close(fd);
139 			return (NULL);
140 		}
141 	}
142 
143 	return (iop);
144 }
145