1 64f7506b 2006-02-24 devnull #include <u.h>
2 64f7506b 2006-02-24 devnull #include <libc.h>
3 64f7506b 2006-02-24 devnull #include <auth.h>
4 64f7506b 2006-02-24 devnull #include <fcall.h>
5 64f7506b 2006-02-24 devnull #include "tapefs.h"
8 64f7506b 2006-02-24 devnull * File system for tar tapes (read-only)
11 64f7506b 2006-02-24 devnull #define TBLOCK 512
12 64f7506b 2006-02-24 devnull #define NBLOCK 40 /* maximum blocksize */
13 64f7506b 2006-02-24 devnull #define DBLOCK 20 /* default blocksize */
14 64f7506b 2006-02-24 devnull #define TNAMSIZ 100
16 64f7506b 2006-02-24 devnull union hblock {
17 64f7506b 2006-02-24 devnull char dummy[TBLOCK];
18 64f7506b 2006-02-24 devnull char tbuf[Maxbuf];
19 64f7506b 2006-02-24 devnull struct header {
20 64f7506b 2006-02-24 devnull char name[TNAMSIZ];
21 64f7506b 2006-02-24 devnull char mode[8];
22 64f7506b 2006-02-24 devnull char uid[8];
23 64f7506b 2006-02-24 devnull char gid[8];
24 64f7506b 2006-02-24 devnull char size[12];
25 64f7506b 2006-02-24 devnull char mtime[12];
26 64f7506b 2006-02-24 devnull char chksum[8];
27 64f7506b 2006-02-24 devnull char linkflag;
28 64f7506b 2006-02-24 devnull char linkname[TNAMSIZ];
30 64f7506b 2006-02-24 devnull } dblock;
32 64f7506b 2006-02-24 devnull int tapefile;
33 64f7506b 2006-02-24 devnull int checksum(void);
36 64f7506b 2006-02-24 devnull populate(char *name)
38 64f7506b 2006-02-24 devnull long blkno, isabs, chksum, linkflg;
39 64f7506b 2006-02-24 devnull Fileinf f;
41 64f7506b 2006-02-24 devnull tapefile = open(name, OREAD);
42 64f7506b 2006-02-24 devnull if (tapefile<0)
43 64f7506b 2006-02-24 devnull error("Can't open argument file");
44 64f7506b 2006-02-24 devnull replete = 1;
45 64f7506b 2006-02-24 devnull for (blkno = 0;;) {
46 64f7506b 2006-02-24 devnull seek(tapefile, TBLOCK*blkno, 0);
47 64f7506b 2006-02-24 devnull if (read(tapefile, dblock.dummy, sizeof(dblock.dummy))<sizeof(dblock.dummy))
49 64f7506b 2006-02-24 devnull if (dblock.dbuf.name[0]=='\0')
51 64f7506b 2006-02-24 devnull f.addr = blkno+1;
52 64f7506b 2006-02-24 devnull f.mode = strtoul(dblock.dbuf.mode, 0, 8);
53 64f7506b 2006-02-24 devnull f.uid = strtoul(dblock.dbuf.uid, 0, 8);
54 64f7506b 2006-02-24 devnull f.gid = strtoul(dblock.dbuf.gid, 0, 8);
55 64f7506b 2006-02-24 devnull if((uchar)dblock.dbuf.size[0] == 0x80)
56 38c7eb9b 2006-05-21 devnull f.size = b8byte(dblock.dbuf.size+3);
58 64f7506b 2006-02-24 devnull f.size = strtoull(dblock.dbuf.size, 0, 8);
59 64f7506b 2006-02-24 devnull f.mdate = strtoul(dblock.dbuf.mtime, 0, 8);
60 64f7506b 2006-02-24 devnull chksum = strtoul(dblock.dbuf.chksum, 0, 8);
61 64f7506b 2006-02-24 devnull /* the mode test is ugly but sometimes necessary */
62 64f7506b 2006-02-24 devnull if (dblock.dbuf.linkflag == '5'
63 64f7506b 2006-02-24 devnull || (f.mode&0170000) == 040000
64 64f7506b 2006-02-24 devnull || strrchr(dblock.dbuf.name, '\0')[-1] == '/'){
65 64f7506b 2006-02-24 devnull f.mode |= DMDIR;
66 64f7506b 2006-02-24 devnull f.size = 0;
68 64f7506b 2006-02-24 devnull f.mode &= DMDIR|0777;
69 64f7506b 2006-02-24 devnull linkflg = dblock.dbuf.linkflag=='s' || dblock.dbuf.linkflag=='1';
70 64f7506b 2006-02-24 devnull isabs = dblock.dbuf.name[0]=='/';
71 64f7506b 2006-02-24 devnull if (chksum != checksum()){
72 64f7506b 2006-02-24 devnull fprint(1, "bad checksum on %.28s\n", dblock.dbuf.name);
73 64f7506b 2006-02-24 devnull exits("checksum");
75 64f7506b 2006-02-24 devnull if (linkflg) {
76 64f7506b 2006-02-24 devnull /*fprint(2, "link %s->%s skipped\n", dblock.dbuf.name,
77 64f7506b 2006-02-24 devnull dblock.dbuf.linkname);*/
78 64f7506b 2006-02-24 devnull f.size = 0;
79 64f7506b 2006-02-24 devnull blkno += 1;
80 64f7506b 2006-02-24 devnull continue;
82 64f7506b 2006-02-24 devnull f.name = dblock.dbuf.name+isabs;
83 64f7506b 2006-02-24 devnull if (f.name[0]=='\0')
84 64f7506b 2006-02-24 devnull fprint(1, "null name skipped\n");
86 64f7506b 2006-02-24 devnull poppath(f, 1);
87 64f7506b 2006-02-24 devnull blkno += 1 + (f.size+TBLOCK-1)/TBLOCK;
92 64f7506b 2006-02-24 devnull dotrunc(Ram *r)
98 64f7506b 2006-02-24 devnull docreate(Ram *r)
100 64f7506b 2006-02-24 devnull USED(r);
104 64f7506b 2006-02-24 devnull doread(Ram *r, vlong off, long cnt)
106 64f7506b 2006-02-24 devnull seek(tapefile, TBLOCK*r->addr+off, 0);
107 64f7506b 2006-02-24 devnull if (cnt>sizeof(dblock.tbuf))
108 64f7506b 2006-02-24 devnull error("read too big");
109 64f7506b 2006-02-24 devnull read(tapefile, dblock.tbuf, cnt);
110 64f7506b 2006-02-24 devnull return dblock.tbuf;
114 64f7506b 2006-02-24 devnull popdir(Ram *r)
116 64f7506b 2006-02-24 devnull USED(r);
120 64f7506b 2006-02-24 devnull dowrite(Ram *r, char *buf, long off, long cnt)
122 64f7506b 2006-02-24 devnull USED(r); USED(buf); USED(off); USED(cnt);
126 64f7506b 2006-02-24 devnull dopermw(Ram *r)
128 64f7506b 2006-02-24 devnull USED(r);
129 64f7506b 2006-02-24 devnull return 0;
133 64f7506b 2006-02-24 devnull checksum()
136 64f7506b 2006-02-24 devnull char *cp;
138 64f7506b 2006-02-24 devnull for (cp = dblock.dbuf.chksum; cp < &dblock.dbuf.chksum[sizeof(dblock.dbuf.chksum)]; cp++)
139 64f7506b 2006-02-24 devnull *cp = ' ';
141 64f7506b 2006-02-24 devnull for (cp = dblock.dummy; cp < &dblock.dummy[TBLOCK]; cp++)
142 64f7506b 2006-02-24 devnull i += *cp&0xff;
143 64f7506b 2006-02-24 devnull return(i);
