1 files changed, 609 insertions, 0 deletions

diff --git a/src/cmd/vac/pack.c b/src/cmd/vac/pack.c
new file mode 100644
index 00000000..b16834d9
--- /dev/null
+++ b/src/cmd/vac/pack.c
@@ -0,0 +1,609 @@
+#include "stdinc.h"
+#include "vac.h"
+#include "dat.h"
+#include "fns.h"
+#include "error.h"
+
+typedef struct MetaChunk MetaChunk;
+
+struct MetaChunk {
+	ushort offset;
+	ushort size;
+	ushort index;
+};
+
+static int	stringUnpack(char **s, uchar **p, int *n);
+
+/*
+ * integer conversion routines
+ */
+#define	U8GET(p)	((p)[0])
+#define	U16GET(p)	(((p)[0]<<8)|(p)[1])
+#define	U32GET(p)	(((p)[0]<<24)|((p)[1]<<16)|((p)[2]<<8)|(p)[3])
+#define	U48GET(p)	(((uvlong)U16GET(p)<<32)|(uvlong)U32GET((p)+2))
+#define	U64GET(p)	(((uvlong)U32GET(p)<<32)|(uvlong)U32GET((p)+4))
+
+#define	U8PUT(p,v)	(p)[0]=(v)
+#define	U16PUT(p,v)	(p)[0]=(v)>>8;(p)[1]=(v)
+#define	U32PUT(p,v)	(p)[0]=(v)>>24;(p)[1]=(v)>>16;(p)[2]=(v)>>8;(p)[3]=(v)
+#define	U48PUT(p,v,t32)	t32=(v)>>32;U16PUT(p,t32);t32=(v);U32PUT((p)+2,t32)
+#define	U64PUT(p,v,t32)	t32=(v)>>32;U32PUT(p,t32);t32=(v);U32PUT((p)+4,t32)
+
+static int
+stringUnpack(char **s, uchar **p, int *n)
+{
+	int nn;
+
+	if(*n < 2)
+		return 0;
+	
+	nn = U16GET(*p);
+	*p += 2;
+	*n -= 2;
+	if(nn > *n)
+		return 0;
+	*s = vtMemAlloc(nn+1);
+	memmove(*s, *p, nn);
+	(*s)[nn] = 0;
+	*p += nn;
+	*n -= nn;
+	return 1;
+}
+
+static int
+stringPack(char *s, uchar *p)
+{
+	int n;
+
+	n = strlen(s);
+	U16PUT(p, n);
+	memmove(p+2, s, n);
+	return n+2;
+}
+
+
+int
+mbUnpack(MetaBlock *mb, uchar *p, int n)
+{
+	u32int magic;
+
+	mb->maxsize = n;
+	mb->buf = p;
+
+	if(n == 0) {
+		memset(mb, 0, sizeof(MetaBlock));
+		return 1;
+	}
+
+	magic = U32GET(p);
+	if(magic != MetaMagic && magic != MetaMagic+1) {
+		vtSetError("bad meta block magic");
+		return 0;
+	}
+	mb->size = U16GET(p+4);
+	mb->free = U16GET(p+6);
+	mb->maxindex = U16GET(p+8);
+	mb->nindex = U16GET(p+10);
+	mb->unbotch = (magic == MetaMagic+1);
+
+	if(mb->size > n) {
+		vtSetError("bad meta block size");
+		return 0;
+	}
+	p += MetaHeaderSize;
+	n -= MetaHeaderSize;
+
+	USED(p);
+	if(n < mb->maxindex*MetaIndexSize) {
+ 		vtSetError("truncated meta block 2");
+		return 0;
+	}
+	return 1;
+}
+
+void
+mbPack(MetaBlock *mb)
+{
+	uchar *p;
+
+	p = mb->buf;
+
+	U32PUT(p, MetaMagic);
+	U16PUT(p+4, mb->size);
+	U16PUT(p+6, mb->free);
+	U16PUT(p+8, mb->maxindex);
+	U16PUT(p+10, mb->nindex);
+}
+
+
+void
+mbDelete(MetaBlock *mb, int i, MetaEntry *me)
+{
+	uchar *p;
+	int n;
+
+	assert(i < mb->nindex);
+
+	if(me->p - mb->buf + me->size == mb->size)
+		mb->size -= me->size;
+	else
+		mb->free += me->size;
+
+	p = mb->buf + MetaHeaderSize + i*MetaIndexSize;
+	n = (mb->nindex-i-1)*MetaIndexSize;
+	memmove(p, p+MetaIndexSize, n);
+	memset(p+n, 0, MetaIndexSize);
+	mb->nindex--;
+}
+
+void
+mbInsert(MetaBlock *mb, int i, MetaEntry *me)
+{
+	uchar *p;
+	int o, n;
+
+	assert(mb->nindex < mb->maxindex);
+
+	o = me->p - mb->buf;
+	n = me->size;
+	if(o+n > mb->size) {
+		mb->free -= mb->size - o;
+		mb->size = o + n;
+	} else
+		mb->free -= n;
+
+	p = mb->buf + MetaHeaderSize + i*MetaIndexSize;
+	n = (mb->nindex-i)*MetaIndexSize;
+	memmove(p+MetaIndexSize, p, n);
+	U16PUT(p, me->p - mb->buf);
+	U16PUT(p+2, me->size);
+	mb->nindex++;
+}
+
+int
+meUnpack(MetaEntry *me, MetaBlock *mb, int i)
+{
+	uchar *p;
+	int eo, en;
+
+	if(i < 0 || i >= mb->nindex) {
+		vtSetError("bad meta entry index");
+		return 0;
+	}
+
+	p = mb->buf + MetaHeaderSize + i*MetaIndexSize;
+	eo = U16GET(p);
+	en = U16GET(p+2);
+
+if(0)print("eo = %d en = %d\n", eo, en);
+	if(eo < MetaHeaderSize + mb->maxindex*MetaIndexSize) {
+		vtSetError("corrupted entry in meta block");
+		return 0;
+	}
+
+	if(eo+en > mb->size) {
+ 		vtSetError("truncated meta block");
+		return 0;
+	}
+
+	p = mb->buf + eo;
+	
+	/* make sure entry looks ok and includes an elem name */
+	if(en < 8 || U32GET(p) != DirMagic || en < 8 + U16GET(p+6)) {
+		vtSetError("corrupted meta block entry");
+		return 0;
+	}
+
+	me->p = p;
+	me->size = en;
+
+	return 1;
+}
+
+/* assumes a small amount of checking has been done in mbEntry */
+int
+meCmp(MetaEntry *me, char *s)
+{
+	int n;
+	uchar *p;
+
+	p = me->p;
+
+	p += 6;
+	n = U16GET(p);
+	p += 2;
+
+	assert(n + 8 < me->size);
+
+	while(n > 0) {
+		if(*s == 0)
+			return -1;
+		if(*p < (uchar)*s)
+			return -1;
+		if(*p > (uchar)*s)
+			return 1;
+		p++;
+		s++;
+		n--;
+	}
+	return *s != 0;
+}
+
+int
+meCmpNew(MetaEntry *me, char *s)
+{
+	int n;
+	uchar *p;
+
+	p = me->p;
+
+	p += 6;
+	n = U16GET(p);
+	p += 2;
+
+	assert(n + 8 < me->size);
+
+	while(n > 0) {
+		if(*s == 0)
+			return 1;
+		if(*p < (uchar)*s)
+			return -1;
+		if(*p > (uchar)*s)
+			return 1;
+		p++;
+		s++;
+		n--;
+	}
+	return -(*s != 0);
+}
+
+static int
+offsetCmp(void *s0, void *s1)
+{
+	MetaChunk *mc0, *mc1;
+
+	mc0 = s0;
+	mc1 = s1;
+	if(mc0->offset < mc1->offset)
+		return -1;
+	if(mc0->offset > mc1->offset)
+		return 1;
+	return 0;
+}
+
+static MetaChunk *
+metaChunks(MetaBlock *mb)
+{
+	MetaChunk *mc;
+	int oo, o, n, i;
+	uchar *p;
+
+	mc = vtMemAlloc(mb->nindex*sizeof(MetaChunk));
+	p = mb->buf + MetaHeaderSize;
+	for(i = 0; i<mb->nindex; i++) {
+		mc[i].offset = U16GET(p);
+		mc[i].size = U16GET(p+2);
+		mc[i].index = i;
+		p += MetaIndexSize;
+	}
+
+	qsort(mc, mb->nindex, sizeof(MetaChunk), offsetCmp);
+
+	/* check block looks ok */
+	oo = MetaHeaderSize + mb->maxindex*MetaIndexSize;
+	o = oo;
+	n = 0;
+	for(i=0; i<mb->nindex; i++) {
+		o = mc[i].offset;
+		n = mc[i].size;
+		if(o < oo)
+			goto Err;
+		oo += n;
+	}
+	if(o+n <= mb->size)
+		goto Err;
+	if(mb->size - oo != mb->free)
+		goto Err;
+
+	return mc;
+Err:
+	vtMemFree(mc);
+	return nil;
+}
+
+static void
+mbCompact(MetaBlock *mb, MetaChunk *mc)
+{
+	int oo, o, n, i;
+
+	oo = MetaHeaderSize + mb->maxindex*MetaIndexSize;
+	
+	for(i=0; i<mb->nindex; i++) {
+		o = mc[i].offset;
+		n = mc[i].size;
+		if(o != oo) {
+			memmove(mb->buf + oo, mb->buf + o, n);
+			U16PUT(mb->buf + MetaHeaderSize + mc[i].index*MetaIndexSize, oo);
+		}
+		oo += n;
+	}
+
+	mb->size = oo;
+	mb->free = 0;
+}
+
+uchar *
+mbAlloc(MetaBlock *mb, int n)
+{
+	int i, o;
+	MetaChunk *mc;
+
+	/* off the end */
+	if(mb->maxsize - mb->size >= n)
+		return mb->buf + mb->size;
+
+	/* check if possible */
+	if(mb->maxsize - mb->size + mb->free < n)
+		return nil;
+
+	mc = metaChunks(mb);
+
+	/* look for hole */
+	o = MetaHeaderSize + mb->maxindex*MetaIndexSize;
+	for(i=0; i<mb->nindex; i++) {
+		if(mc[i].offset - o >= n) {
+			vtMemFree(mc);
+			return mb->buf + o;
+		}
+		o = mc[i].offset + mc[i].size;
+	}
+
+	if(mb->maxsize - o >= n) {
+		vtMemFree(mc);
+		return mb->buf + o;
+	}
+
+	/* compact and return off the end */
+	mbCompact(mb, mc);
+	vtMemFree(mc);
+
+	assert(mb->maxsize - mb->size >= n);
+	return mb->buf + mb->size;
+}
+
+int
+vdSize(VacDir *dir)
+{
+	int n;
+	
+	/* constant part */
+
+	n = 	4 +	/* magic */
+		2 + 	/* version */
+		4 +	/* entry */
+		4 + 	/* guid */
+		4 + 	/* mentry */
+		4 + 	/* mgen */
+		8 +	/* qid */
+		4 + 	/* mtime */
+		4 + 	/* mcount */
+		4 + 	/* ctime */
+		4 + 	/* atime */
+		4 +	/* mode */
+		0;
+
+	/* strings */
+	n += 2 + strlen(dir->elem);
+	n += 2 + strlen(dir->uid);
+	n += 2 + strlen(dir->gid);
+	n += 2 + strlen(dir->mid);
+
+	/* optional sections */
+	if(dir->qidSpace) {
+		n += 	3 + 	/* option header */
+			8 + 	/* qidOffset */
+			8;	/* qid Max */
+	}
+
+	return n;
+}
+
+void
+vdPack(VacDir *dir, MetaEntry *me)
+{
+	uchar *p;
+	ulong t32;
+
+	p = me->p;
+	
+	U32PUT(p, DirMagic);
+	U16PUT(p+4, 9);		/* version */
+	p += 6;
+
+	p += stringPack(dir->elem, p);
+
+	U32PUT(p, dir->entry);
+	U32PUT(p+4, dir->gen);
+	U32PUT(p+8, dir->mentry);
+	U32PUT(p+12, dir->mgen);
+	U64PUT(p+16, dir->qid, t32);
+	p += 24;
+
+	p += stringPack(dir->uid, p);
+	p += stringPack(dir->gid, p);
+	p += stringPack(dir->mid, p);
+	
+	U32PUT(p, dir->mtime);
+	U32PUT(p+4, dir->mcount);
+	U32PUT(p+8, dir->ctime);
+	U32PUT(p+12, dir->atime);
+	U32PUT(p+16, dir->mode);
+	p += 5*4;
+
+	if(dir->qidSpace) {
+		U8PUT(p, DirQidSpaceEntry);
+		U16PUT(p+1, 2*8);
+		p += 3;
+		U64PUT(p, dir->qidOffset, t32);
+		U64PUT(p+8, dir->qidMax, t32);
+	}
+
+	assert(p == me->p + me->size);
+}
+
+
+int
+vdUnpack(VacDir *dir, MetaEntry *me)
+{
+	int t, nn, n, version;
+	uchar *p;
+	
+	p = me->p;
+	n = me->size;
+
+	memset(dir, 0, sizeof(VacDir));
+
+if(0)print("vdUnpack\n");
+	/* magic */
+	if(n < 4 || U32GET(p) != DirMagic)
+		goto Err;
+	p += 4;
+	n -= 4;
+
+if(0)print("vdUnpack: got magic\n");
+	/* version */
+	if(n < 2)
+		goto Err;
+	version = U16GET(p);
+	if(version < 7 || version > 9)
+		goto Err;
+	p += 2;
+	n -= 2;	
+
+if(0)print("vdUnpack: got version\n");
+
+	/* elem */
+	if(!stringUnpack(&dir->elem, &p, &n))
+		goto Err;
+
+if(0)print("vdUnpack: got elem\n");
+
+	/* entry  */
+	if(n < 4)
+		goto Err;
+	dir->entry = U32GET(p);
+	p += 4;
+	n -= 4;
+
+if(0)print("vdUnpack: got entry\n");
+
+	if(version < 9) {
+		dir->gen = 0;
+		dir->mentry = dir->entry+1;
+		dir->mgen = 0;
+	} else {
+		if(n < 3*4)
+			goto Err;
+		dir->gen = U32GET(p);
+		dir->mentry = U32GET(p+4);
+		dir->mgen = U32GET(p+8);
+		p += 3*4;
+		n -= 3*4;
+	}
+
+if(0)print("vdUnpack: got gen etc\n");
+
+	/* size is gotten from DirEntry */
+
+	/* qid */
+	if(n < 8)
+		goto Err;
+	dir->qid = U64GET(p);
+	p += 8;
+	n -= 8;
+
+if(0)print("vdUnpack: got qid\n");
+	/* skip replacement */
+	if(version == 7) {
+		if(n < VtScoreSize)
+			goto Err;
+		p += VtScoreSize;
+		n -= VtScoreSize;
+	}
+	
+	/* uid */
+	if(!stringUnpack(&dir->uid, &p, &n))
+		goto Err;
+
+	/* gid */
+	if(!stringUnpack(&dir->gid, &p, &n))
+		goto Err;
+
+	/* mid */
+	if(!stringUnpack(&dir->mid, &p, &n))
+		goto Err;
+
+if(0)print("vdUnpack: got ids\n");
+	if(n < 5*4)
+		goto Err;
+	dir->mtime = U32GET(p);
+	dir->mcount = U32GET(p+4);
+	dir->ctime = U32GET(p+8);
+	dir->atime = U32GET(p+12);
+	dir->mode = U32GET(p+16);
+	p += 5*4;
+	n -= 5*4;
+
+if(0)print("vdUnpack: got times\n");
+	/* optional meta data */
+	while(n > 0) {
+		if(n < 3)
+			goto Err;
+		t = p[0];
+		nn = U16GET(p+1);
+		p += 3;
+		n -= 3;
+		if(n < nn)
+			goto Err;
+		switch(t) {
+		case DirPlan9Entry:
+			/* not valid in version >= 9 */
+			if(version >= 9)
+				break;
+			if(dir->plan9 || nn != 12)
+				goto Err;
+			dir->plan9 = 1;
+			dir->p9path = U64GET(p);
+			dir->p9version = U32GET(p+8);
+			if(dir->mcount == 0)
+				dir->mcount = dir->p9version;
+			break;
+		case DirGenEntry:
+			/* not valid in version >= 9 */
+			if(version >= 9)
+				break;
+			break;
+		case DirQidSpaceEntry:
+			if(dir->qidSpace || nn != 16)
+				goto Err;
+			dir->qidSpace = 1;
+			dir->qidOffset = U64GET(p);
+			dir->qidMax = U64GET(p+8);
+			break;
+		}
+		p += nn;
+		n -= nn;
+	}
+if(0)print("vdUnpack: got options\n");
+
+	if(p != me->p + me->size)
+		goto Err;
+
+if(0)print("vdUnpack: correct size\n");
+	return 1;
+Err:
+if(0)print("vdUnpack: XXXXXXXXXXXX EbadMeta\n");
+	vtSetError(EBadMeta);
+	vdCleanup(dir);
+	return 0;
+}