xref: /dflybsd-src/lib/libc/stdio/fopencookie.c (revision a765cedf26cef470ba7deee42c365f0221690a1a)
1*a765cedfSAntonio Huete Jimenez /*
2*a765cedfSAntonio Huete Jimenez  * Copyright (c) 2016, EMC / Isilon Storage Division
3*a765cedfSAntonio Huete Jimenez  * All rights reserved.
4*a765cedfSAntonio Huete Jimenez  *
5*a765cedfSAntonio Huete Jimenez  * Redistribution and use in source and binary forms, with or without
6*a765cedfSAntonio Huete Jimenez  * modification, are permitted provided that the following conditions
7*a765cedfSAntonio Huete Jimenez  * are met:
8*a765cedfSAntonio Huete Jimenez  * 1. Redistributions of source code must retain the above copyright
9*a765cedfSAntonio Huete Jimenez  *    notice, this list of conditions and the following disclaimer.
10*a765cedfSAntonio Huete Jimenez  * 2. Redistributions in binary form must reproduce the above copyright
11*a765cedfSAntonio Huete Jimenez  *    notice, this list of conditions and the following disclaimer in the
12*a765cedfSAntonio Huete Jimenez  *    documentation and/or other materials provided with the distribution.
13*a765cedfSAntonio Huete Jimenez  *
14*a765cedfSAntonio Huete Jimenez  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
15*a765cedfSAntonio Huete Jimenez  * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
16*a765cedfSAntonio Huete Jimenez  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17*a765cedfSAntonio Huete Jimenez  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
18*a765cedfSAntonio Huete Jimenez  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19*a765cedfSAntonio Huete Jimenez  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20*a765cedfSAntonio Huete Jimenez  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21*a765cedfSAntonio Huete Jimenez  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22*a765cedfSAntonio Huete Jimenez  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23*a765cedfSAntonio Huete Jimenez  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24*a765cedfSAntonio Huete Jimenez  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25*a765cedfSAntonio Huete Jimenez  */
26*a765cedfSAntonio Huete Jimenez 
27*a765cedfSAntonio Huete Jimenez #include <sys/cdefs.h>
28*a765cedfSAntonio Huete Jimenez __FBSDID("$FreeBSD$");
29*a765cedfSAntonio Huete Jimenez 
30*a765cedfSAntonio Huete Jimenez #include <sys/fcntl.h>
31*a765cedfSAntonio Huete Jimenez 
32*a765cedfSAntonio Huete Jimenez #include <errno.h>
33*a765cedfSAntonio Huete Jimenez #include <stdio.h>
34*a765cedfSAntonio Huete Jimenez #include <stdlib.h>
35*a765cedfSAntonio Huete Jimenez 
36*a765cedfSAntonio Huete Jimenez #include "local.h"
37*a765cedfSAntonio Huete Jimenez 
38*a765cedfSAntonio Huete Jimenez struct fopencookie_thunk {
39*a765cedfSAntonio Huete Jimenez 	void			*foc_cookie;
40*a765cedfSAntonio Huete Jimenez 	cookie_io_functions_t	foc_io;
41*a765cedfSAntonio Huete Jimenez };
42*a765cedfSAntonio Huete Jimenez 
43*a765cedfSAntonio Huete Jimenez static int _fopencookie_read(void *, char *, int);
44*a765cedfSAntonio Huete Jimenez static int _fopencookie_write(void *, const char *, int);
45*a765cedfSAntonio Huete Jimenez static fpos_t _fopencookie_seek(void *, fpos_t, int);
46*a765cedfSAntonio Huete Jimenez static int _fopencookie_close(void *);
47*a765cedfSAntonio Huete Jimenez 
48*a765cedfSAntonio Huete Jimenez FILE *
49*a765cedfSAntonio Huete Jimenez fopencookie(void *cookie, const char *mode, cookie_io_functions_t io_funcs)
50*a765cedfSAntonio Huete Jimenez {
51*a765cedfSAntonio Huete Jimenez 	int (*readfn)(void *, char *, int);
52*a765cedfSAntonio Huete Jimenez 	int (*writefn)(void *, const char *, int);
53*a765cedfSAntonio Huete Jimenez 	struct fopencookie_thunk *thunk;
54*a765cedfSAntonio Huete Jimenez 	FILE *fp;
55*a765cedfSAntonio Huete Jimenez 	int flags, oflags;
56*a765cedfSAntonio Huete Jimenez 
57*a765cedfSAntonio Huete Jimenez 	if ((flags = __sflags(mode, &oflags)) == 0)
58*a765cedfSAntonio Huete Jimenez 		return (NULL);
59*a765cedfSAntonio Huete Jimenez 
60*a765cedfSAntonio Huete Jimenez 	thunk = malloc(sizeof(*thunk));
61*a765cedfSAntonio Huete Jimenez 	if (thunk == NULL)
62*a765cedfSAntonio Huete Jimenez 		return (NULL);
63*a765cedfSAntonio Huete Jimenez 
64*a765cedfSAntonio Huete Jimenez 	thunk->foc_cookie = cookie;
65*a765cedfSAntonio Huete Jimenez 	thunk->foc_io = io_funcs;
66*a765cedfSAntonio Huete Jimenez 
67*a765cedfSAntonio Huete Jimenez 	readfn = _fopencookie_read;
68*a765cedfSAntonio Huete Jimenez 	writefn = _fopencookie_write;
69*a765cedfSAntonio Huete Jimenez 	if (flags == __SWR)
70*a765cedfSAntonio Huete Jimenez 		readfn = NULL;
71*a765cedfSAntonio Huete Jimenez 	else if (flags == __SRD)
72*a765cedfSAntonio Huete Jimenez 		writefn = NULL;
73*a765cedfSAntonio Huete Jimenez 
74*a765cedfSAntonio Huete Jimenez 	fp = funopen(thunk, readfn, writefn, _fopencookie_seek,
75*a765cedfSAntonio Huete Jimenez 	    _fopencookie_close);
76*a765cedfSAntonio Huete Jimenez 	if (fp == NULL) {
77*a765cedfSAntonio Huete Jimenez 		free(thunk);
78*a765cedfSAntonio Huete Jimenez 		return (NULL);
79*a765cedfSAntonio Huete Jimenez 	}
80*a765cedfSAntonio Huete Jimenez 
81*a765cedfSAntonio Huete Jimenez 	if ((oflags & O_APPEND) != 0)
82*a765cedfSAntonio Huete Jimenez 		fp->pub._flags |= __SAPP;
83*a765cedfSAntonio Huete Jimenez 
84*a765cedfSAntonio Huete Jimenez 	return (fp);
85*a765cedfSAntonio Huete Jimenez }
86*a765cedfSAntonio Huete Jimenez 
87*a765cedfSAntonio Huete Jimenez static int
88*a765cedfSAntonio Huete Jimenez _fopencookie_read(void *cookie, char *buf, int size)
89*a765cedfSAntonio Huete Jimenez {
90*a765cedfSAntonio Huete Jimenez 	struct fopencookie_thunk *thunk;
91*a765cedfSAntonio Huete Jimenez 
92*a765cedfSAntonio Huete Jimenez 	thunk = cookie;
93*a765cedfSAntonio Huete Jimenez 
94*a765cedfSAntonio Huete Jimenez 	/* Reads from a stream with NULL read return EOF. */
95*a765cedfSAntonio Huete Jimenez 	if (thunk->foc_io.read == NULL)
96*a765cedfSAntonio Huete Jimenez 		return (0);
97*a765cedfSAntonio Huete Jimenez 
98*a765cedfSAntonio Huete Jimenez 	return ((int)thunk->foc_io.read(thunk->foc_cookie, buf, (size_t)size));
99*a765cedfSAntonio Huete Jimenez }
100*a765cedfSAntonio Huete Jimenez 
101*a765cedfSAntonio Huete Jimenez static int
102*a765cedfSAntonio Huete Jimenez _fopencookie_write(void *cookie, const char *buf, int size)
103*a765cedfSAntonio Huete Jimenez {
104*a765cedfSAntonio Huete Jimenez 	struct fopencookie_thunk *thunk;
105*a765cedfSAntonio Huete Jimenez 
106*a765cedfSAntonio Huete Jimenez 	thunk = cookie;
107*a765cedfSAntonio Huete Jimenez 
108*a765cedfSAntonio Huete Jimenez 	/* Writes to a stream with NULL write discard data. */
109*a765cedfSAntonio Huete Jimenez 	if (thunk->foc_io.write == NULL)
110*a765cedfSAntonio Huete Jimenez 		return (size);
111*a765cedfSAntonio Huete Jimenez 
112*a765cedfSAntonio Huete Jimenez 	return ((int)thunk->foc_io.write(thunk->foc_cookie, buf,
113*a765cedfSAntonio Huete Jimenez 		(size_t)size));
114*a765cedfSAntonio Huete Jimenez }
115*a765cedfSAntonio Huete Jimenez 
116*a765cedfSAntonio Huete Jimenez static fpos_t
117*a765cedfSAntonio Huete Jimenez _fopencookie_seek(void *cookie, fpos_t offset, int whence)
118*a765cedfSAntonio Huete Jimenez {
119*a765cedfSAntonio Huete Jimenez 	struct fopencookie_thunk *thunk;
120*a765cedfSAntonio Huete Jimenez 	off64_t off64;
121*a765cedfSAntonio Huete Jimenez 	int res;
122*a765cedfSAntonio Huete Jimenez 
123*a765cedfSAntonio Huete Jimenez 	switch (whence) {
124*a765cedfSAntonio Huete Jimenez 	case SEEK_SET:
125*a765cedfSAntonio Huete Jimenez 	case SEEK_CUR:
126*a765cedfSAntonio Huete Jimenez 	case SEEK_END:
127*a765cedfSAntonio Huete Jimenez 		break;
128*a765cedfSAntonio Huete Jimenez 	default:
129*a765cedfSAntonio Huete Jimenez 		/* fopencookie(3) only allows these three seek modes. */
130*a765cedfSAntonio Huete Jimenez 		errno = EINVAL;
131*a765cedfSAntonio Huete Jimenez 		return (-1);
132*a765cedfSAntonio Huete Jimenez 	}
133*a765cedfSAntonio Huete Jimenez 
134*a765cedfSAntonio Huete Jimenez 	thunk = cookie;
135*a765cedfSAntonio Huete Jimenez 
136*a765cedfSAntonio Huete Jimenez 	/*
137*a765cedfSAntonio Huete Jimenez 	 * If seek is NULL, it is not possible to perform seek operations on
138*a765cedfSAntonio Huete Jimenez 	 * the stream.
139*a765cedfSAntonio Huete Jimenez 	 */
140*a765cedfSAntonio Huete Jimenez 	if (thunk->foc_io.seek == NULL) {
141*a765cedfSAntonio Huete Jimenez 		errno = ENOTSUP;
142*a765cedfSAntonio Huete Jimenez 		return (-1);
143*a765cedfSAntonio Huete Jimenez 	}
144*a765cedfSAntonio Huete Jimenez 
145*a765cedfSAntonio Huete Jimenez 	off64 = (off64_t)offset;
146*a765cedfSAntonio Huete Jimenez 	res = thunk->foc_io.seek(thunk->foc_cookie, &off64, whence);
147*a765cedfSAntonio Huete Jimenez 	if (res < 0)
148*a765cedfSAntonio Huete Jimenez 		return (res);
149*a765cedfSAntonio Huete Jimenez 
150*a765cedfSAntonio Huete Jimenez 	return ((fpos_t)off64);
151*a765cedfSAntonio Huete Jimenez }
152*a765cedfSAntonio Huete Jimenez 
153*a765cedfSAntonio Huete Jimenez static int
154*a765cedfSAntonio Huete Jimenez _fopencookie_close(void *cookie)
155*a765cedfSAntonio Huete Jimenez {
156*a765cedfSAntonio Huete Jimenez 	struct fopencookie_thunk *thunk;
157*a765cedfSAntonio Huete Jimenez 	int ret, serrno;
158*a765cedfSAntonio Huete Jimenez 
159*a765cedfSAntonio Huete Jimenez 	ret = 0;
160*a765cedfSAntonio Huete Jimenez 	thunk = cookie;
161*a765cedfSAntonio Huete Jimenez 	if (thunk->foc_io.close != NULL)
162*a765cedfSAntonio Huete Jimenez 		ret = thunk->foc_io.close(thunk->foc_cookie);
163*a765cedfSAntonio Huete Jimenez 
164*a765cedfSAntonio Huete Jimenez 	serrno = errno;
165*a765cedfSAntonio Huete Jimenez 	free(thunk);
166*a765cedfSAntonio Huete Jimenez 	errno = serrno;
167*a765cedfSAntonio Huete Jimenez 	return (ret);
168*a765cedfSAntonio Huete Jimenez }
169