1 /*
2  * Vax 32V Unix filesystem (same as pre-FFS Berkeley)
3  */
4 #include <u.h>
5 #include <libc.h>
6 #include <auth.h>
7 #include <fcall.h>
8 #include "tapefs.h"
9 
10 /*
11  * v32 disk inode
12  */
13 #define	VNADDR	13
14 #define	VFMT	0160000
15 #define	VIFREG	0100000
16 #define	VIFDIR	0040000
17 #define	VIFCHR	0120000
18 #define	VIFBLK	0160000
19 #define	VMODE	0777
20 #define	VSUPERB	1
21 #define	VROOT		2	/* root inode */
22 #define	VNAMELEN	14
23 #define	MAXBLSIZE	1024
24 int	BLSIZE;
25 #define	LINOPB	(BLSIZE/sizeof(struct v32dinode))
26 #define	LNINDIR	(BLSIZE/4)
27 #define	MAXLNINDIR	(MAXBLSIZE/4)
28 
29 struct v32dinode {
30 	unsigned char flags[2];
31 	unsigned char nlinks[2];
32 	unsigned char uid[2];
33 	unsigned char gid[2];
34 	unsigned char size[4];
35 	unsigned char addr[40];
36 	unsigned char atime[4];
37 	unsigned char mtime[4];
38 	unsigned char ctime[4];
39 };
40 
41 struct	v32dir {
42 	uchar	ino[2];
43 	char	name[VNAMELEN];
44 };
45 
46 int	tapefile;
47 Fileinf	iget(int ino);
48 long	bmap(Ram *r, long bno);
49 void	getblk(Ram *r, long bno, char *buf);
50 
51 void
52 populate(char *name)
53 {
54 	Fileinf f;
55 
56 	BLSIZE = 512;	/* 32v */
57 	if(blocksize){
58 		/* 1024 for 4.1BSD */
59 		if(blocksize != 512 && blocksize != 1024)
60 			error("bad block size");
61 		BLSIZE = blocksize;
62 	}
63 	replete = 0;
64 	tapefile = open(name, OREAD);
65 	if (tapefile<0)
66 		error("Can't open argument file");
67 	f = iget(VROOT);
68 	ram->perm = f.mode;
69 	ram->mtime = f.mdate;
70 	ram->addr = f.addr;
71 	ram->data = f.data;
72 	ram->ndata = f.size;
73 }
74 
75 void
76 popdir(Ram *r)
77 {
78 	int i, ino;
79 	char *cp;
80 	struct v32dir *dp;
81 	Fileinf f;
82 	char name[VNAMELEN+1];
83 
84 	cp = 0;
85 	for (i=0; i<r->ndata; i+=sizeof(struct v32dir)) {
86 		if (i%BLSIZE==0)
87 			cp = doread(r, i, BLSIZE);
88 		dp = (struct v32dir *)(cp+i%BLSIZE);
89 		ino = g2byte(dp->ino);
90 		if (strcmp(dp->name, ".")==0 || strcmp(dp->name, "..")==0)
91 			continue;
92 		if (ino==0)
93 			continue;
94 		f = iget(ino);
95 		strncpy(name, dp->name, VNAMELEN);
96 		name[VNAMELEN] = '\0';
97 		f.name = name;
98 		popfile(r, f);
99 	}
100 	r->replete = 1;
101 }
102 
103 void
104 dotrunc(Ram *r)
105 {
106 	USED(r);
107 }
108 
109 void
110 docreate(Ram *r)
111 {
112 	USED(r);
113 }
114 
115 char *
116 doread(Ram *r, vlong off, long cnt)
117 {
118 	static char buf[Maxbuf+MAXBLSIZE];
119 	int bno, i;
120 
121 	bno = off/BLSIZE;
122 	off -= bno*BLSIZE;
123 	if (cnt>Maxbuf)
124 		error("count too large");
125 	if (off)
126 		cnt += off;
127 	i = 0;
128 	while (cnt>0) {
129 		getblk(r, bno, &buf[i*BLSIZE]);
130 		cnt -= BLSIZE;
131 		bno++;
132 		i++;
133 	}
134 	return buf;
135 }
136 
137 void
138 dowrite(Ram *r, char *buf, long off, long cnt)
139 {
140 	USED(r); USED(buf); USED(off); USED(cnt);
141 }
142 
143 int
144 dopermw(Ram *r)
145 {
146 	USED(r);
147 	return 0;
148 }
149 
150 /*
151  * fetch an i-node
152  * -- no sanity check for now
153  * -- magic inode-to-disk-block stuff here
154  */
155 
156 Fileinf
157 iget(int ino)
158 {
159 	char buf[MAXBLSIZE];
160 	struct v32dinode *dp;
161 	long flags, i;
162 	Fileinf f;
163 
164 	memset(&f, 0, sizeof f);
165 	seek(tapefile, BLSIZE*((ino-1)/LINOPB + VSUPERB + 1), 0);
166 	if (read(tapefile, buf, BLSIZE) != BLSIZE)
167 		error("Can't read inode");
168 	dp = ((struct v32dinode *)buf) + ((ino-1)%LINOPB);
169 	flags = g2byte(dp->flags);
170 	f.size = g4byte(dp->size);
171 	if ((flags&VFMT)==VIFCHR || (flags&VFMT)==VIFBLK)
172 		f.size = 0;
173 	f.data = emalloc(VNADDR*sizeof(long));
174 	for (i = 0; i < VNADDR; i++)
175 		((long*)f.data)[i] = g3byte(dp->addr+3*i);
176 	f.mode = flags & VMODE;
177 	if ((flags&VFMT)==VIFDIR)
178 		f.mode |= DMDIR;
179 	f.uid = g2byte(dp->uid);
180 	f.gid = g2byte(dp->gid);
181 	f.mdate = g4byte(dp->mtime);
182 	return f;
183 }
184 
185 void
186 getblk(Ram *r, long bno, char *buf)
187 {
188 	long dbno;
189 
190 	if ((dbno = bmap(r, bno)) == 0) {
191 		memset(buf, 0, BLSIZE);
192 		return;
193 	}
194 	seek(tapefile, dbno*BLSIZE, 0);
195 	if (read(tapefile, buf, BLSIZE) != BLSIZE)
196 		error("bad read");
197 }
198 
199 /*
200  * logical to physical block
201  * only singly-indirect files for now
202  */
203 
204 long
205 bmap(Ram *r, long bno)
206 {
207 	unsigned char indbuf[LNINDIR][sizeof(long)];
208 
209 	if (bno < VNADDR-3)
210 		return ((long*)r->data)[bno];
211 	if (bno < VNADDR*LNINDIR) {
212 		seek(tapefile, ((long *)r->data)[(bno-(VNADDR-3))/LNINDIR]*BLSIZE, 0);
213 		if (read(tapefile, (char *)indbuf, BLSIZE) != BLSIZE)
214 			return 0;
215 		return ((indbuf[bno%LNINDIR][1]<<8) + indbuf[bno%LNINDIR][0]);
216 	}
217 	return 0;
218 }