1 /*
2 * Copyright (c) 2016, EMC / Isilon Storage Division
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
15 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
16 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <sys/fcntl.h>
31
32 #include <errno.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35
36 #include "local.h"
37
38 struct fopencookie_thunk {
39 void *foc_cookie;
40 cookie_io_functions_t foc_io;
41 };
42
43 static int _fopencookie_read(void *, char *, int);
44 static int _fopencookie_write(void *, const char *, int);
45 static fpos_t _fopencookie_seek(void *, fpos_t, int);
46 static int _fopencookie_close(void *);
47
48 FILE *
fopencookie(void * cookie,const char * mode,cookie_io_functions_t io_funcs)49 fopencookie(void *cookie, const char *mode, cookie_io_functions_t io_funcs)
50 {
51 int (*readfn)(void *, char *, int);
52 int (*writefn)(void *, const char *, int);
53 struct fopencookie_thunk *thunk;
54 FILE *fp;
55 int flags, oflags;
56
57 if ((flags = __sflags(mode, &oflags)) == 0)
58 return (NULL);
59
60 thunk = malloc(sizeof(*thunk));
61 if (thunk == NULL)
62 return (NULL);
63
64 thunk->foc_cookie = cookie;
65 thunk->foc_io = io_funcs;
66
67 readfn = _fopencookie_read;
68 writefn = _fopencookie_write;
69 if (flags == __SWR)
70 readfn = NULL;
71 else if (flags == __SRD)
72 writefn = NULL;
73
74 fp = funopen(thunk, readfn, writefn, _fopencookie_seek,
75 _fopencookie_close);
76 if (fp == NULL) {
77 free(thunk);
78 return (NULL);
79 }
80
81 if ((oflags & O_APPEND) != 0)
82 fp->pub._flags |= __SAPP;
83
84 return (fp);
85 }
86
87 static int
_fopencookie_read(void * cookie,char * buf,int size)88 _fopencookie_read(void *cookie, char *buf, int size)
89 {
90 struct fopencookie_thunk *thunk;
91
92 thunk = cookie;
93
94 /* Reads from a stream with NULL read return EOF. */
95 if (thunk->foc_io.read == NULL)
96 return (0);
97
98 return ((int)thunk->foc_io.read(thunk->foc_cookie, buf, (size_t)size));
99 }
100
101 static int
_fopencookie_write(void * cookie,const char * buf,int size)102 _fopencookie_write(void *cookie, const char *buf, int size)
103 {
104 struct fopencookie_thunk *thunk;
105
106 thunk = cookie;
107
108 /* Writes to a stream with NULL write discard data. */
109 if (thunk->foc_io.write == NULL)
110 return (size);
111
112 return ((int)thunk->foc_io.write(thunk->foc_cookie, buf,
113 (size_t)size));
114 }
115
116 static fpos_t
_fopencookie_seek(void * cookie,fpos_t offset,int whence)117 _fopencookie_seek(void *cookie, fpos_t offset, int whence)
118 {
119 struct fopencookie_thunk *thunk;
120 off_t off64;
121 int res;
122
123 switch (whence) {
124 case SEEK_SET:
125 case SEEK_CUR:
126 case SEEK_END:
127 break;
128 default:
129 /* fopencookie(3) only allows these three seek modes. */
130 errno = EINVAL;
131 return (-1);
132 }
133
134 thunk = cookie;
135
136 /*
137 * If seek is NULL, it is not possible to perform seek operations on
138 * the stream.
139 */
140 if (thunk->foc_io.seek == NULL) {
141 errno = ENOTSUP;
142 return (-1);
143 }
144
145 off64 = (off_t)offset;
146 res = thunk->foc_io.seek(thunk->foc_cookie, &off64, whence);
147 if (res < 0)
148 return (res);
149
150 return ((fpos_t)off64);
151 }
152
153 static int
_fopencookie_close(void * cookie)154 _fopencookie_close(void *cookie)
155 {
156 struct fopencookie_thunk *thunk;
157 int ret, serrno;
158
159 ret = 0;
160 thunk = cookie;
161 if (thunk->foc_io.close != NULL)
162 ret = thunk->foc_io.close(thunk->foc_cookie);
163
164 serrno = errno;
165 free(thunk);
166 errno = serrno;
167 return (ret);
168 }
169