Annotation of src/usr.bin/compress/nullopen.c, Revision 1.2
1.2 ! millert 1: /* $OpenBSD: nullopen.c,v 1.1 2003/09/05 06:08:15 deraadt Exp $ */
1.1 deraadt 2:
3: /*
4: * Copyright (c) 2003 Can Erkin Acar
5: * Copyright (c) 1997 Michael Shalayeff
6: * All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: *
17: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19: * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27: * SUCH DAMAGE.
28: *
29: */
30:
31: const char null_rcsid[] =
1.2 ! millert 32: "$OpenBSD: nullopen.c,v 1.1 2003/09/05 06:08:15 deraadt Exp $";
1.1 deraadt 33:
34: #include <sys/types.h>
35: #include <stdio.h>
36: #include <stdlib.h>
37: #include <errno.h>
38: #include <unistd.h>
39: #include "compress.h"
40:
41: typedef struct {
42: off_t total_in;
43: off_t total_out;
44: int fd;
45: int gotmagic;
46: char mode;
47: } null_stream;
48:
49: char null_magic[2];
50:
51:
52: void *
53: null_open(int fd, const char *mode, char *name, int bits,
54: u_int32_t mtime, int gotmagic)
55: {
56: null_stream *s;
57:
58: if (fd < 0 || !mode)
59: return NULL;
60:
61: if ((mode[0] != 'r' && mode[0] != 'w') || mode[1] != '\0') {
62: errno = EINVAL;
63: return NULL;
64: }
65:
66: if ((s = (null_stream *) calloc(1, sizeof(null_stream))) == NULL)
67: return NULL;
68:
69: s->fd = fd;
70: s->gotmagic = gotmagic;
71: s->total_in = s->total_out = 0;
72: s->mode = mode[0];
73:
74: return s;
75: }
76:
77: int
78: null_close(void *cookie, struct z_info *info)
79: {
80: null_stream *s = (null_stream*) cookie;
81: int err = 0;
82:
83: if (s == NULL)
84: return -1;
85:
86:
87: if (info != NULL) {
88: info->mtime = 0;
89: info->crc = (u_int32_t)-1;
90: info->hlen = 0;
91: info->total_in = (off_t) s->total_in;
92: info->total_out = (off_t) s->total_out;
93: }
94:
95: err = close(s->fd);
96:
97: free(s);
98:
99: return err;
100: }
101:
102: int
103: null_flush(void *cookie, int flush)
104: {
105: null_stream *s = (null_stream*)cookie;
106:
107: if (s == NULL || s->mode != 'w') {
108: errno = EBADF;
109: return (-1);
110: }
111:
112: return 0;
113: }
114:
115: int
116: null_read(void *cookie, char *buf, int len)
117: {
118: null_stream *s = (null_stream*)cookie;
119:
120: if (s == NULL) {
121: errno = EBADF;
122: return (-1);
123: }
124: if (s->gotmagic) {
125: if (len < 2) {
126: errno = EBADF;
127: return (-1);
128: }
129:
130: buf[0] = null_magic[0];
131: buf[1] = null_magic[1];
132: s->gotmagic = 0;
133:
134: return (2);
135: }
136:
137: return read(s->fd, buf, len);
138: }
139:
140: int
141: null_write(void *cookie, const char *buf, int len)
142: {
143: null_stream *s = (null_stream*)cookie;
144:
145: if (s == NULL) {
146: errno = EBADF;
147: return (-1);
148: }
149:
150: return write(s->fd, buf, len);
151: }