1 /* Copyright 1996,1997,1999,2001-2003,2008,2009 Alain Knaff.
2 * This file is part of mtools.
3 *
4 * Mtools is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
8 *
9 * Mtools is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with Mtools. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include "sysincludes.h"
19 #include "msdos.h"
20 #include "mtools.h"
21 #include "codepage.h"
22
23 typedef struct Filter_t {
24 Class_t *Class;
25 int refs;
26 Stream_t *Next;
27 Stream_t *Buffer;
28
29 int dospos;
30 int unixpos;
31 int mode;
32 int rw;
33 int lastchar;
34 /* int convertCharset; */
35 } Filter_t;
36
37 #define F_READ 1
38 #define F_WRITE 2
39
40 /* read filter filters out messy dos' bizarre end of lines and final 0x1a's */
41
read_filter(Stream_t * Stream,char * buf,mt_off_t iwhere,size_t len)42 static int read_filter(Stream_t *Stream, char *buf, mt_off_t iwhere, size_t len)
43 {
44 DeclareThis(Filter_t);
45 int i,j,ret;
46 unsigned char newchar;
47
48 off_t where = truncBytes32(iwhere);
49
50 if ( where != This->unixpos ){
51 fprintf(stderr,"Bad offset\n");
52 exit(1);
53 }
54 if (This->rw == F_WRITE){
55 fprintf(stderr,"Change of transfer direction!\n");
56 exit(1);
57 }
58 This->rw = F_READ;
59
60 ret = READS(This->Next, buf, (mt_off_t) This->dospos, len);
61 if ( ret < 0 )
62 return ret;
63
64 j = 0;
65 for (i=0; i< ret; i++){
66 if ( buf[i] == '\r' )
67 continue;
68 if (buf[i] == 0x1a)
69 break;
70 newchar = buf[i];
71 /*
72 if (This->convertCharset) newchar = contents_to_unix(newchar);
73 */
74 This->lastchar = buf[j++] = newchar;
75 }
76
77 This->dospos += i;
78 This->unixpos += j;
79 return j;
80 }
81
write_filter(Stream_t * Stream,char * buf,mt_off_t iwhere,size_t len)82 static int write_filter(Stream_t *Stream, char *buf, mt_off_t iwhere,
83 size_t len)
84 {
85 DeclareThis(Filter_t);
86 unsigned int i,j;
87 int ret;
88 char buffer[1025];
89 unsigned char newchar;
90
91 off_t where = truncBytes32(iwhere);
92
93 if(This->unixpos == -1)
94 return -1;
95
96 if (where != This->unixpos ){
97 fprintf(stderr,"Bad offset\n");
98 exit(1);
99 }
100
101 if (This->rw == F_READ){
102 fprintf(stderr,"Change of transfer direction!\n");
103 exit(1);
104 }
105 This->rw = F_WRITE;
106
107 j=i=0;
108 while(i < 1024 && j < len){
109 if (buf[j] == '\n' ){
110 buffer[i++] = '\r';
111 buffer[i++] = '\n';
112 j++;
113 continue;
114 }
115 newchar = buf[j++];
116 /*
117 if (This->convertCharset) newchar = to_dos(newchar);
118 */
119 buffer[i++] = newchar;
120 }
121 This->unixpos += j;
122
123 ret = force_write(This->Next, buffer, (mt_off_t) This->dospos, i);
124 if(ret >0 )
125 This->dospos += ret;
126 if ( ret != (signed int) i ){
127 /* no space on target file ? */
128 This->unixpos = -1;
129 return -1;
130 }
131 return j;
132 }
133
free_filter(Stream_t * Stream)134 static int free_filter(Stream_t *Stream)
135 {
136 DeclareThis(Filter_t);
137 char buffer=0x1a;
138
139 /* write end of file */
140 if (This->rw == F_WRITE)
141 return force_write(This->Next, &buffer, (mt_off_t) This->dospos, 1);
142 else
143 return 0;
144 }
145
146 static Class_t FilterClass = {
147 read_filter,
148 write_filter,
149 0, /* flush */
150 free_filter,
151 0, /* set geometry */
152 get_data_pass_through,
153 0,
154 0, /* get_dosconvert */
155 0 /* discard */
156 };
157
open_filter(Stream_t * Next,int convertCharset UNUSEDP)158 Stream_t *open_filter(Stream_t *Next, int convertCharset UNUSEDP)
159 {
160 Filter_t *This;
161
162 This = New(Filter_t);
163 if (!This)
164 return NULL;
165 This->Class = &FilterClass;
166 This->dospos = This->unixpos = This->rw = 0;
167 This->Next = Next;
168 This->refs = 1;
169 This->Buffer = 0;
170 /*
171 This->convertCharset = convertCharset;
172 */
173
174 return (Stream_t *) This;
175 }
176