1 /* $NetBSD: dosfile.c,v 1.2 2024/06/29 13:46:40 rin 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 struct dosfile {
41 int doshandle, off;
42 };
43
44 extern int doserrno; /* in dos_file.S */
45
46 static int dos2errno(void);
47
48 static int
dos2errno(void)49 dos2errno(void)
50 {
51 int err;
52
53 switch (doserrno) {
54 case 1: /* invalid function number */
55 case 4: /* too many open files */
56 case 12: /* invalid access mode */
57 default:
58 err = EIO;
59 break;
60 case 2: /* file not found */
61 case 3: /* path not found */
62 err = ENOENT;
63 break;
64 case 5: /* access denied */
65 err = EPERM;
66 break;
67 case 6: /* invalid handle */
68 err = EINVAL;
69 break;
70 }
71 return err;
72 }
73
74 __compactcall int
dos_open(const char * path,struct open_file * f)75 dos_open(const char *path, struct open_file *f)
76 {
77 struct dosfile *df;
78
79 df = (struct dosfile *) alloc(sizeof(*df));
80 if (!df)
81 return -1;
82
83 df->off = 0;
84 df->doshandle = dosopen(path);
85 if (df->doshandle < 0) {
86 #ifdef DEBUG
87 printf("DOS error %d\n", doserrno);
88 #endif
89 dealloc(df, sizeof(*df));
90 return dos2errno();
91 }
92 f->f_fsdata = (void *) df;
93 return 0;
94 }
95
96 __compactcall int
dos_read(struct open_file * f,void * addr,size_t size,size_t * resid)97 dos_read(struct open_file *f, void *addr, size_t size, size_t *resid)
98 {
99 struct dosfile *df;
100 int got;
101 static int tc = 0;
102
103 df = (struct dosfile *) f->f_fsdata;
104
105 if (!(tc++ % 4))
106 twiddle();
107
108 if ((unsigned long) addr >= 0x10000) {
109 u_int lsize = size;
110
111 while (lsize > 0) {
112 u_int tsize;
113 size_t tgot;
114 char *p = addr;
115
116 tsize = lsize;
117
118 if (tsize > DISKBUFSIZE)
119 tsize = DISKBUFSIZE;
120
121 alloc_diskbuf(dos_read);
122
123 tgot = dosread(df->doshandle, diskbufp, tsize);
124 if (tgot < 0) {
125 #ifdef DEBUG
126 printf("DOS error %d\n", doserrno);
127 #endif
128 return dos2errno();
129 }
130 memcpy(p, diskbufp, tgot);
131
132 p += tgot;
133 lsize -= tgot;
134
135 if (tgot != tsize)
136 break; /* EOF */
137 }
138 got = size - lsize;
139 } else {
140 got = dosread(df->doshandle, addr, size);
141
142 if (got < 0) {
143 #ifdef DEBUG
144 printf("DOS error %d\n", doserrno);
145 #endif
146 return dos2errno();
147 }
148 }
149
150 df->off += got;
151 size -= got;
152
153 if (resid)
154 *resid = size;
155 return 0;
156 }
157
158 __compactcall int
dos_close(struct open_file * f)159 dos_close(struct open_file *f)
160 {
161 struct dosfile *df;
162 df = (struct dosfile *) f->f_fsdata;
163
164 dosclose(df->doshandle);
165
166 if (df)
167 dealloc(df, sizeof(*df));
168 return 0;
169 }
170
171 __compactcall int
dos_write(struct open_file * f,void * start,size_t size,size_t * resid)172 dos_write(struct open_file *f, void *start, size_t size, size_t *resid)
173 {
174 return EROFS;
175 }
176
177 __compactcall int
dos_stat(struct open_file * f,struct stat * sb)178 dos_stat(struct open_file *f, struct stat *sb)
179 {
180 sb->st_mode = 0444;
181 sb->st_nlink = 1;
182 sb->st_uid = 0;
183 sb->st_gid = 0;
184 sb->st_size = -1;
185 return 0;
186 }
187
188 __compactcall off_t
dos_seek(struct open_file * f,off_t offset,int where)189 dos_seek(struct open_file *f, off_t offset, int where)
190 {
191 struct dosfile *df;
192 int doswhence, res;
193 #ifdef DOS_CHECK
194 int checkoffs;
195 #endif
196 df = (struct dosfile *) f->f_fsdata;
197
198 switch (where) {
199 case SEEK_SET:
200 doswhence = 0;
201 #ifdef DOS_CHECK
202 checkoffs = offset; /* don't trust DOS */
203 #endif
204 break;
205 case SEEK_CUR:
206 doswhence = 1;
207 #ifdef DOS_CHECK
208 checkoffs = df->off + offset;
209 #endif
210 break;
211 case SEEK_END:
212 doswhence = 2;
213 #ifdef DOS_CHECK
214 checkoffs = -1; /* we dont know len */
215 #endif
216 break;
217 default:
218 errno = EOFFSET;
219 return -1;
220 }
221 res = dosseek(df->doshandle, offset, doswhence);
222 if (res == -1) {
223 errno = dos2errno();
224 return -1;
225 }
226 #ifdef DOS_CHECK
227 if ((checkoffs != -1) && (res != checkoffs)) {
228 printf("dosfile: unexpected seek result (%d+%d(%d)=%d)\n",
229 df->off, offset, where, res);
230 errno = EOFFSET;
231 return -1;
232 }
233 #endif
234 df->off = res;
235 return res;
236 }
237