1 #include <u.h>
2 #include <libc.h>
3 #include <venti.h>
4 #include "cvt.h"
5 
6 static int
7 checksize(int n)
8 {
9 	if(n < 256) {
10 		werrstr("bad block size");
11 		return -1;
12 	}
13 	return 0;
14 }
15 
16 extern int vttobig(ulong);
17 
18 void
19 vtrootpack(VtRoot *r, uchar *p)
20 {
21 	uchar *op = p;
22 	int vers, bsize;
23 
24 	vers = VtRootVersion;
25 	bsize = r->blocksize;
26 	if(bsize >= (1<<16)) {
27 		vers |= _VtRootVersionBig;
28 		bsize = vttobig(bsize);
29 		if(bsize < 0)
30 			sysfatal("invalid root blocksize: %#lx", r->blocksize);
31 	}
32 	U16PUT(p, vers);
33 	p += 2;
34 	memmove(p, r->name, sizeof(r->name));
35 	p += sizeof(r->name);
36 	memmove(p, r->type, sizeof(r->type));
37 	p += sizeof(r->type);
38 	memmove(p, r->score, VtScoreSize);
39 	p +=  VtScoreSize;
40 	U16PUT(p, bsize);
41 	p += 2;
42 	memmove(p, r->prev, VtScoreSize);
43 	p += VtScoreSize;
44 
45 	assert(p-op == VtRootSize);
46 }
47 
48 int
49 vtrootunpack(VtRoot *r, uchar *p)
50 {
51 	uchar *op = p;
52 	uint vers;
53 	memset(r, 0, sizeof(*r));
54 
55 	vers = U16GET(p);
56 	if((vers&~_VtRootVersionBig) != VtRootVersion) {
57 		werrstr("unknown root version");
58 		return -1;
59 	}
60 	p += 2;
61 	memmove(r->name, p, sizeof(r->name));
62 	r->name[sizeof(r->name)-1] = 0;
63 	p += sizeof(r->name);
64 	memmove(r->type, p, sizeof(r->type));
65 	r->type[sizeof(r->type)-1] = 0;
66 	p += sizeof(r->type);
67 	memmove(r->score, p, VtScoreSize);
68 	p +=  VtScoreSize;
69 	r->blocksize = U16GET(p);
70 	if(vers & _VtRootVersionBig)
71 		r->blocksize = (r->blocksize >> 5) << (r->blocksize & 31);
72 	if(checksize(r->blocksize) < 0)
73 		return -1;
74 	p += 2;
75 	memmove(r->prev, p, VtScoreSize);
76 	p += VtScoreSize;
77 
78 	assert(p-op == VtRootSize);
79 	return 0;
80 }