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Annotation of src/usr.bin/compress/nullopen.c, Revision 1.5

1.5     ! deraadt     1: /*     $OpenBSD: nullopen.c,v 1.4 2011/09/22 10:41:04 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: #include <sys/types.h>
                     32: #include <stdio.h>
                     33: #include <stdlib.h>
                     34: #include <errno.h>
                     35: #include <unistd.h>
                     36: #include "compress.h"
                     37:
                     38: typedef struct {
                     39:        off_t     total_in;
                     40:        off_t     total_out;
                     41:        int       fd;
                     42:        int       gotmagic;
                     43:        char      mode;
                     44: } null_stream;
                     45:
                     46: char null_magic[2];
                     47:
                     48:
                     49: void *
                     50: null_open(int fd, const char *mode, char *name, int bits,
                     51:     u_int32_t mtime, int gotmagic)
                     52: {
                     53:        null_stream *s;
                     54:
                     55:        if (fd < 0 || !mode)
                     56:                return NULL;
                     57:
                     58:        if ((mode[0] != 'r' && mode[0] != 'w') || mode[1] != '\0') {
                     59:                errno = EINVAL;
                     60:                return NULL;
                     61:        }
                     62:
1.5     ! deraadt    63:        if ((s = calloc(1, sizeof(null_stream))) == NULL)
1.1       deraadt    64:                return NULL;
                     65:
                     66:        s->fd = fd;
                     67:        s->gotmagic = gotmagic;
                     68:        s->total_in = s->total_out = 0;
                     69:        s->mode = mode[0];
                     70:
                     71:        return s;
                     72: }
                     73:
                     74: int
1.3       otto       75: null_close(void *cookie, struct z_info *info, const char *name, struct stat *sb)
1.1       deraadt    76: {
                     77:        null_stream *s = (null_stream*) cookie;
                     78:        int err = 0;
                     79:
                     80:        if (s == NULL)
                     81:                return -1;
                     82:
                     83:
                     84:        if (info != NULL) {
                     85:                info->mtime = 0;
                     86:                info->crc =  (u_int32_t)-1;
                     87:                info->hlen = 0;
                     88:                info->total_in = (off_t) s->total_in;
                     89:                info->total_out = (off_t) s->total_out;
                     90:        }
                     91:
1.3       otto       92:        setfile(name, s->fd, sb);
1.1       deraadt    93:        err = close(s->fd);
                     94:
                     95:        free(s);
                     96:
                     97:        return err;
                     98: }
                     99:
                    100: int
                    101: null_flush(void *cookie, int flush)
                    102: {
                    103:        null_stream *s = (null_stream*)cookie;
                    104:
                    105:        if (s == NULL || s->mode != 'w') {
                    106:                errno = EBADF;
                    107:                return (-1);
                    108:        }
                    109:
                    110:        return 0;
                    111: }
                    112:
                    113: int
                    114: null_read(void *cookie, char *buf, int len)
                    115: {
                    116:        null_stream *s = (null_stream*)cookie;
                    117:
                    118:        if (s == NULL) {
                    119:                errno = EBADF;
                    120:                return (-1);
                    121:        }
                    122:        if (s->gotmagic) {
                    123:                if (len < 2) {
                    124:                        errno = EBADF;
                    125:                        return (-1);
                    126:                }
                    127:
                    128:                buf[0] = null_magic[0];
                    129:                buf[1] = null_magic[1];
                    130:                s->gotmagic = 0;
                    131:
                    132:                return (2);
                    133:        }
                    134:
                    135:        return read(s->fd, buf, len);
                    136: }
                    137:
                    138: int
                    139: null_write(void *cookie, const char *buf, int len)
                    140: {
                    141:        null_stream *s = (null_stream*)cookie;
                    142:
                    143:        if (s == NULL) {
                    144:                errno = EBADF;
                    145:                return (-1);
                    146:        }
                    147:
                    148:        return write(s->fd, buf, len);
                    149: }