1 /* $NetBSD: dosfile.c,v 1.16 2013/10/20 21:06:37 christos Exp $ */
2
3 /*
4 * Copyright (c) 1996
5 * Matthias Drochner. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 */
28
29 /*
30 * DOS filesystem for libsa
31 * standalone - uses no device, works only with DOS running
32 * needs lowlevel parts from dos_file.S
33 */
34
35 #include <lib/libsa/stand.h>
36
37 #include "diskbuf.h"
38 #include "dosfile.h"
39
40 extern int dosopen(const char *);
41 extern void dosclose(int);
42 extern int dosread(int, char *, int);
43 extern int dosseek(int, int, int);
44
45 struct dosfile {
46 int doshandle, off;
47 };
48
49 extern int doserrno; /* in dos_file.S */
50
51 static int dos2errno(void);
52
53 static int
dos2errno(void)54 dos2errno(void)
55 {
56 int err;
57
58 switch (doserrno) {
59 case 1:
60 case 4:
61 case 12:
62 default:
63 err = EIO;
64 case 2:
65 case 3:
66 err = ENOENT;
67 case 5:
68 err = EPERM;
69 case 6:
70 err = EINVAL;
71 }
72 return err;
73 }
74
75 __compactcall int
dos_open(const char * path,struct open_file * f)76 dos_open(const char *path, struct open_file *f)
77 {
78 struct dosfile *df;
79
80 df = (struct dosfile *) alloc(sizeof(*df));
81 if (!df)
82 return -1;
83
84 df->off = 0;
85 df->doshandle = dosopen(path);
86 if (df->doshandle < 0) {
87 #ifdef DEBUG
88 printf("DOS error %d\n", doserrno);
89 #endif
90 dealloc(df, sizeof(*df));
91 return dos2errno();
92 }
93 f->f_fsdata = (void *) df;
94 return 0;
95 }
96
97 __compactcall int
dos_read(struct open_file * f,void * addr,size_t size,size_t * resid)98 dos_read(struct open_file *f, void *addr, size_t size, size_t *resid)
99 {
100 struct dosfile *df;
101 int got;
102 static int tc = 0;
103
104 df = (struct dosfile *) f->f_fsdata;
105
106 if (!(tc++ % 4))
107 twiddle();
108
109 if ((unsigned long) addr >= 0x10000) {
110 u_int lsize = size;
111
112 while (lsize > 0) {
113 u_int tsize;
114 size_t tgot;
115 char *p = addr;
116
117 tsize = lsize;
118
119 if (tsize > DISKBUFSIZE)
120 tsize = DISKBUFSIZE;
121
122 alloc_diskbuf(dos_read);
123
124 tgot = dosread(df->doshandle, diskbufp, tsize);
125 if (tgot < 0) {
126 #ifdef DEBUG
127 printf("DOS error %d\n", doserrno);
128 #endif
129 return dos2errno();
130 }
131 memcpy(p, diskbufp, tgot);
132
133 p += tgot;
134 lsize -= tgot;
135
136 if (tgot != tsize)
137 break; /* EOF */
138 }
139 got = size - lsize;
140 } else {
141 got = dosread(df->doshandle, addr, size);
142
143 if (got < 0) {
144 #ifdef DEBUG
145 printf("DOS error %d\n", doserrno);
146 #endif
147 return dos2errno();
148 }
149 }
150
151 df->off += got;
152 size -= got;
153
154 if (resid)
155 *resid = size;
156 return 0;
157 }
158
159 __compactcall int
dos_close(struct open_file * f)160 dos_close(struct open_file *f)
161 {
162 struct dosfile *df;
163 df = (struct dosfile *) f->f_fsdata;
164
165 dosclose(df->doshandle);
166
167 if (df)
168 dealloc(df, sizeof(*df));
169 return 0;
170 }
171
172 __compactcall int
dos_write(struct open_file * f,void * start,size_t size,size_t * resid)173 dos_write(struct open_file *f, void *start, size_t size, size_t *resid)
174 {
175 return EROFS;
176 }
177
178 __compactcall int
dos_stat(struct open_file * f,struct stat * sb)179 dos_stat(struct open_file *f, struct stat *sb)
180 {
181 sb->st_mode = 0444;
182 sb->st_nlink = 1;
183 sb->st_uid = 0;
184 sb->st_gid = 0;
185 sb->st_size = -1;
186 return 0;
187 }
188
189 __compactcall off_t
dos_seek(struct open_file * f,off_t offset,int where)190 dos_seek(struct open_file *f, off_t offset, int where)
191 {
192 struct dosfile *df;
193 int doswhence, res;
194 #ifdef DOS_CHECK
195 int checkoffs;
196 #endif
197 df = (struct dosfile *) f->f_fsdata;
198
199 switch (where) {
200 case SEEK_SET:
201 doswhence = 0;
202 #ifdef DOS_CHECK
203 checkoffs = offset; /* don't trust DOS */
204 #endif
205 break;
206 case SEEK_CUR:
207 doswhence = 1;
208 #ifdef DOS_CHECK
209 checkoffs = df->off + offset;
210 #endif
211 break;
212 case SEEK_END:
213 doswhence = 2;
214 #ifdef DOS_CHECK
215 checkoffs = -1; /* we dont know len */
216 #endif
217 break;
218 default:
219 errno = EOFFSET;
220 return -1;
221 }
222 res = dosseek(df->doshandle, offset, doswhence);
223 if (res == -1) {
224 errno = dos2errno();
225 return -1;
226 }
227 #ifdef DOS_CHECK
228 if ((checkoffs != -1) && (res != checkoffs)) {
229 printf("dosfile: unexpected seek result (%d+%d(%d)=%d)\n",
230 df->off, offset, where, res);
231 errno = EOFFSET;
232 return -1;
233 }
234 #endif
235 df->off = res;
236 return res;
237 }
238