1 /*
2     Copyright (c) 2010 - 2012, Intel Corporation. All rights reserved.<BR>
3     This program and the accompanying materials are licensed and made available
4     under the terms and conditions of the BSD License that accompanies this
5     distribution.  The full text of the license may be found at
6     http://opensource.org/licenses/bsd-license.
7 
8     THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
9     WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
10 
11  * Copyright (c) 1990, 1993
12  *  The Regents of the University of California.  All rights reserved.
13  *
14  * This code is derived from software contributed to Berkeley by
15  * Chris Torek.
16  *
17  * Redistribution and use in source and binary forms, with or without
18  * modification, are permitted provided that the following conditions
19  * are met:
20  * 1. Redistributions of source code must retain the above copyright
21  *    notice, this list of conditions and the following disclaimer.
22  * 2. Redistributions in binary form must reproduce the above copyright
23  *    notice, this list of conditions and the following disclaimer in the
24  *    documentation and/or other materials provided with the distribution.
25  * 3. Neither the name of the University nor the names of its contributors
26  *    may be used to endorse or promote products derived from this software
27  *    without specific prior written permission.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39  * SUCH DAMAGE.
40 
41     NetBSD: refill.c,v 1.13 2003/08/07 16:43:30 agc Exp
42     refill.c  8.1 (Berkeley) 6/4/93
43 */
44 #include  <LibConfig.h>
45 #include <sys/EfiCdefs.h>
46 
47 #include <assert.h>
48 #include <errno.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include "reentrant.h"
52 #include "local.h"
53 
54 #ifdef _REENTRANT
55 extern rwlock_t __sfp_lock;
56 #endif
57 
58 static int lflush(FILE *);
59 
60 static int
lflush(FILE * fp)61 lflush(FILE *fp)
62 {
63 
64   _DIAGASSERT(fp != NULL);
65   if(fp == NULL) {
66     errno = EINVAL;
67     return (EOF);
68   }
69 
70   if ((fp->_flags & (__SLBF|__SWR)) == (__SLBF|__SWR))
71     return (__sflush(fp));
72   return (0);
73 }
74 
75 /*
76  * Refill a stdio buffer.
77  * Return EOF on eof or error, 0 otherwise.
78  */
79 int
__srefill(FILE * fp)80 __srefill(FILE *fp)
81 {
82 
83   _DIAGASSERT(fp != NULL);
84   if(fp == NULL) {
85     errno = EINVAL;
86     return (EOF);
87   }
88 
89   /* make sure stdio is set up */
90   if (!__sdidinit)
91     __sinit();
92 
93   fp->_r = 0;   /* largely a convenience for callers */
94 
95   /* SysV does not make this test; take it out for compatibility */
96   if (fp->_flags & __SEOF) {
97     return (EOF);
98   }
99 
100   /* if not already reading, have to be reading and writing */
101   if ((fp->_flags & __SRD) == 0) {
102     if ((fp->_flags & __SRW) == 0) {
103       errno = EBADF;
104       fp->_flags |= __SERR;   //<dvm> Allows differentiation between errors and EOF
105       return (EOF);
106     }
107     /* switch to reading */
108     if (fp->_flags & __SWR) {
109       if (__sflush(fp)) {
110         return (EOF);
111       }
112       fp->_flags &= ~__SWR;
113       fp->_w = 0;
114       fp->_lbfsize = 0;
115     }
116     fp->_flags |= __SRD;
117   } else {
118     /*
119      * We were reading.  If there is an ungetc buffer,
120      * we must have been reading from that.  Drop it,
121      * restoring the previous buffer (if any).  If there
122      * is anything in that buffer, return.
123      */
124     if (HASUB(fp)) {
125       FREEUB(fp);
126       if ((fp->_r = fp->_ur) != 0) {
127         fp->_p = fp->_up;
128         return (0);
129       }
130     }
131   }
132 
133   if (fp->_bf._base == NULL)
134     __smakebuf(fp);
135 
136   /*
137    * Before reading from a line buffered or unbuffered file,
138    * flush all line buffered output files, per the ANSI C
139    * standard.
140    */
141   if (fp->_flags & (__SLBF|__SNBF)) {
142     rwlock_rdlock(&__sfp_lock);
143     (void) _fwalk(lflush);
144     rwlock_unlock(&__sfp_lock);
145   }
146   fp->_p = fp->_bf._base;
147   fp->_r = (*fp->_read)(fp->_cookie, (char *)fp->_p, fp->_bf._size);
148   fp->_flags &= ~__SMOD;  /* buffer contents are again pristine */
149   if (fp->_r <= 0) {
150     if (fp->_r == 0)
151       fp->_flags |= __SEOF;
152     else {
153       fp->_r = 0;
154       fp->_flags |= __SERR;
155     }
156     return (EOF);
157   }
158   return (0);
159 }
160