plan9port

unzip.c (14165B)

---

 #include <u.h>
 #include <libc.h>
 #include <bio.h>
 #include <flate.h>
 #include "zip.h"
 
 enum
 {
 	BufSize	= 4096
 };
 
 static	int	cheader(Biobuf *bin, ZipHead *zh);
 static	int	copyout(int ofd, Biobuf *bin, long len);
 static	int	crcwrite(void *ofd, void *buf, int n);
 static	int	findCDir(Biobuf *bin, char *file);
 static	int	get1(Biobuf *b);
 static	int	get2(Biobuf *b);
 static	u32int	get4(Biobuf *b);
 static	char	*getname(Biobuf *b, int len);
 static	int	header(Biobuf *bin, ZipHead *zh);
 static	long	msdos2time(int time, int date);
 static	int	sunzip(Biobuf *bin);
 static	int	sunztable(Biobuf *bin);
 static	void	trailer(Biobuf *bin, ZipHead *zh);
 static	int	unzip(Biobuf *bin, char *file);
 static	int	unzipEntry(Biobuf *bin, ZipHead *czh);
 static	int	unztable(Biobuf *bin, char *file);
 static	int	wantFile(char *file);
 
 static	void	*emalloc(u32int);
 static	void	error(char*, ...);
 /* #pragma	varargck	argpos	error	1 */
 
 static	Biobuf	bin;
 static	u32int	crc;
 static	u32int	*crctab;
 static	int	debug;
 static	char	*delfile;
 static	int	lower;
 static	int	nwant;
 static	u32int	rlen;
 static	int	settimes;
 static	int	stdout;
 static	int	verbose;
 static	char	**want;
 static	int	wbad;
 static	u32int	wlen;
 static	jmp_buf	zjmp;
 
 static void
 usage(void)
 {
 	fprint(2, "usage: unzip [-tsv] [-f zipfile] [file ...]\n");
 	exits("usage");
 }
 
 void
 main(int argc, char *argv[])
 {
 	char *zfile;
 	int fd, ok, table, stream;
 
 	table = 0;
 	stream = 0;
 	zfile = nil;
 	ARGBEGIN{
 	case 'D':
 		debug++;
 		break;
 	case 'c':
 		stdout++;
 		break;
 	case 'i':
 		lower++;
 		break;
 	case 'f':
 		zfile = ARGF();
 		if(zfile == nil)
 			usage();
 		break;
 	case 's':
 		stream++;
 		break;
 	case 't':
 		table++;
 		break;
 	case 'T':
 		settimes++;
 		break;
 	case 'v':
 		verbose++;
 		break;
 	default:
 		usage();
 		break;
 	}ARGEND
 
 	nwant = argc;
 	want = argv;
 
 	crctab = mkcrctab(ZCrcPoly);
 	ok = inflateinit();
 	if(ok != FlateOk)
 		sysfatal("inflateinit failed: %s\n", flateerr(ok));
 
 	if(zfile == nil){
 		Binit(&bin, 0, OREAD);
 		zfile = "<stdin>";
 	}else{
 		fd = open(zfile, OREAD);
 		if(fd < 0)
 			sysfatal("can't open %s: %r", zfile);
 		Binit(&bin, fd, OREAD);
 	}
 
 	if(table){
 		if(stream)
 			ok = sunztable(&bin);
 		else
 			ok = unztable(&bin, zfile);
 	}else{
 		if(stream)
 			ok = sunzip(&bin);
 		else
 			ok = unzip(&bin, zfile);
 	}
 
 	exits(ok ? nil: "errors");
 }
 
 /*
  * print the table of contents from the "central directory structure"
  */
 static int
 unztable(Biobuf *bin, char *file)
 {
 	ZipHead zh;
 	int volatile entries;
 
 	entries = findCDir(bin, file);
 	if(entries < 0)
 		return 0;
 
 	if(verbose > 1)
 		print("%d items in the archive\n", entries);
 	while(entries-- > 0){
 		if(setjmp(zjmp)){
 			free(zh.file);
 			return 0;
 		}
 
 		memset(&zh, 0, sizeof(zh));
 		if(!cheader(bin, &zh))
 			return 1;
 
 		if(wantFile(zh.file)){
 			if(verbose)
 				print("%-32s %10lud %s", zh.file, zh.uncsize, ctime(msdos2time(zh.modtime, zh.moddate)));
 			else
 				print("%s\n", zh.file);
 
 			if(verbose > 1){
 				print("\tmade by os %d vers %d.%d\n", zh.madeos, zh.madevers/10, zh.madevers % 10);
 				print("\textract by os %d vers %d.%d\n", zh.extos, zh.extvers/10, zh.extvers % 10);
 				print("\tflags %x\n", zh.flags);
 				print("\tmethod %d\n", zh.meth);
 				print("\tmod time %d\n", zh.modtime);
 				print("\tmod date %d\n", zh.moddate);
 				print("\tcrc %lux\n", zh.crc);
 				print("\tcompressed size %lud\n", zh.csize);
 				print("\tuncompressed size %lud\n", zh.uncsize);
 				print("\tinternal attributes %ux\n", zh.iattr);
 				print("\texternal attributes %lux\n", zh.eattr);
 				print("\tstarts at %ld\n", zh.off);
 			}
 		}
 
 		free(zh.file);
 		zh.file = nil;
 	}
 
 	return 1;
 }
 
 /*
  * print the "local file header" table of contents
  */
 static int
 sunztable(Biobuf *bin)
 {
 	ZipHead zh;
 	vlong off;
 	u32int hcrc, hcsize, huncsize;
 	int ok, err;
 
 	ok = 1;
 	for(;;){
 		if(setjmp(zjmp)){
 			free(zh.file);
 			return 0;
 		}
 
 		memset(&zh, 0, sizeof(zh));
 		if(!header(bin, &zh))
 			return ok;
 
 		hcrc = zh.crc;
 		hcsize = zh.csize;
 		huncsize = zh.uncsize;
 
 		wlen = 0;
 		rlen = 0;
 		crc = 0;
 		wbad = 0;
 
 		if(zh.meth == 0){
 			if(!copyout(-1, bin, zh.csize))
 				error("reading data for %s failed: %r", zh.file);
 		}else if(zh.meth == 8){
 			off = Boffset(bin);
 			err = inflate((void*)-1, crcwrite, bin, (int(*)(void*))Bgetc);
 			if(err != FlateOk)
 				error("inflate %s failed: %s", zh.file, flateerr(err));
 			rlen = Boffset(bin) - off;
 		}else
 			error("can't handle compression method %d for %s", zh.meth, zh.file);
 
 		trailer(bin, &zh);
 
 		if(wantFile(zh.file)){
 			if(verbose)
 				print("%-32s %10lud %s", zh.file, zh.uncsize, ctime(msdos2time(zh.modtime, zh.moddate)));
 			else
 				print("%s\n", zh.file);
 
 			if(verbose > 1){
 				print("\textract by os %d vers %d.%d\n", zh.extos, zh.extvers / 10, zh.extvers % 10);
 				print("\tflags %x\n", zh.flags);
 				print("\tmethod %d\n", zh.meth);
 				print("\tmod time %d\n", zh.modtime);
 				print("\tmod date %d\n", zh.moddate);
 				print("\tcrc %lux\n", zh.crc);
 				print("\tcompressed size %lud\n", zh.csize);
 				print("\tuncompressed size %lud\n", zh.uncsize);
 				if((zh.flags & ZTrailInfo) && (hcrc || hcsize || huncsize)){
 					print("\theader crc %lux\n", zh.crc);
 					print("\theader compressed size %lud\n", zh.csize);
 					print("\theader uncompressed size %lud\n", zh.uncsize);
 				}
 			}
 		}
 
 		if(zh.crc != crc)
 			error("crc mismatch for %s", zh.file);
 		if(zh.uncsize != wlen)
 			error("output size mismatch for %s", zh.file);
 		if(zh.csize != rlen)
 			error("input size mismatch for %s", zh.file);
 
 
 		free(zh.file);
 		zh.file = nil;
 	}
 }
 
 /*
  * extract files using the info in the central directory structure
  */
 static int
 unzip(Biobuf *bin, char *file)
 {
 	ZipHead zh;
 	vlong off;
 	int volatile ok, eok, entries;
 
 	entries = findCDir(bin, file);
 	if(entries < 0)
 		return 0;
 
 	ok = 1;
 	while(entries-- > 0){
 		if(setjmp(zjmp)){
 			free(zh.file);
 			return 0;
 		}
 		memset(&zh, 0, sizeof(zh));
 		if(!cheader(bin, &zh))
 			return ok;
 
 
 		off = Boffset(bin);
 		if(wantFile(zh.file)){
 			if(Bseek(bin, zh.off, 0) < 0){
 				fprint(2, "unzip: can't seek to start of %s, skipping\n", zh.file);
 				ok = 0;
 			}else{
 				eok = unzipEntry(bin, &zh);
 				if(eok <= 0){
 					fprint(2, "unzip: skipping %s\n", zh.file);
 					ok = 0;
 				}
 			}
 		}
 
 		free(zh.file);
 		zh.file = nil;
 
 		if(Bseek(bin, off, 0) < 0){
 			fprint(2, "unzip: can't seek to start of next entry, terminating extraction\n");
 			return 0;
 		}
 	}
 
 	return ok;
 }
 
 /*
  * extract files using the info the "local file headers"
  */
 static int
 sunzip(Biobuf *bin)
 {
 	int eok;
 
 	for(;;){
 		eok = unzipEntry(bin, nil);
 		if(eok == 0)
 			return 1;
 		if(eok < 0)
 			return 0;
 	}
 }
 
 static int
 makedir(char *s)
 {
 	int f;
 
 	if (access(s, AEXIST) == 0)
 		return -1;
 	f = create(s, OREAD, DMDIR | 0777);
 	if (f >= 0)
 		close(f);
 	return f;
 }
 
 static void
 mkpdirs(char *s)
 {
 	int done = 0;
 	char *p = s;
 
 	while (!done && (p = strchr(p + 1, '/')) != nil) {
 		*p = '\0';
 		done = (access(s, AEXIST) < 0 && makedir(s) < 0);
 		*p = '/';
 	}
 }
 
 /*
  * extracts a single entry from a zip file
  * czh is the optional corresponding central directory entry
  */
 static int
 unzipEntry(Biobuf *bin, ZipHead *czh)
 {
 	Dir *d;
 	ZipHead zh;
 	char *p;
 	vlong off;
 	int fd, isdir, ok, err;
 
 	zh.file = nil;
 	if(setjmp(zjmp)){
 		delfile = nil;
 		free(zh.file);
 		return -1;
 	}
 
 	memset(&zh, 0, sizeof(zh));
 	if(!header(bin, &zh))
 		return 0;
 
 	ok = 1;
 	isdir = 0;
 
 	fd = -1;
 	if(wantFile(zh.file)){
 		if(verbose)
 			fprint(2, "extracting %s\n", zh.file);
 
 		if(czh != nil && czh->extos == ZDos){
 			isdir = czh->eattr & ZDDir;
 			if(isdir && zh.uncsize != 0)
 				fprint(2, "unzip: ignoring directory data for %s\n", zh.file);
 		}
 		if(zh.meth == 0 && zh.uncsize == 0){
 			p = strchr(zh.file, '\0');
 			if(p > zh.file && p[-1] == '/')
 				isdir = 1;
 		}
 
 		if(stdout){
 			if(ok && !isdir)
 				fd = 1;
 		}else if(isdir){
 			fd = create(zh.file, OREAD, DMDIR | 0775);
 			if(fd < 0){
 				mkpdirs(zh.file);
 				fd = create(zh.file, OREAD, DMDIR | 0775);
 			}
 			if(fd < 0){
 				d = dirstat(zh.file);
 				if(d == nil || (d->mode & DMDIR) != DMDIR){
 					fprint(2, "unzip: can't create directory %s: %r\n", zh.file);
 					ok = 0;
 				}
 				free(d);
 			}
 		}else if(ok){
 			fd = create(zh.file, OWRITE, 0664);
 			if(fd < 0){
 				mkpdirs(zh.file);
 				fd = create(zh.file, OWRITE, 0664);
 			}
 			if(fd < 0){
 				fprint(2, "unzip: can't create %s: %r\n", zh.file);
 				ok = 0;
 			}else
 				delfile = zh.file;
 		}
 	}
 
 	wlen = 0;
 	rlen = 0;
 	crc = 0;
 	wbad = 0;
 
 	if(zh.meth == 0){
 		if(!copyout(fd, bin, zh.csize))
 			error("copying data for %s failed: %r", zh.file);
 	}else if(zh.meth == 8){
 		off = Boffset(bin);
 		err = inflate((void*)(uintptr)fd, crcwrite, bin, (int(*)(void*))Bgetc);
 		if(err != FlateOk)
 			error("inflate failed: %s", flateerr(err));
 		rlen = Boffset(bin) - off;
 	}else
 		error("can't handle compression method %d for %s", zh.meth, zh.file);
 
 	trailer(bin, &zh);
 
 	if(zh.crc != crc)
 		error("crc mismatch for %s", zh.file);
 	if(zh.uncsize != wlen)
 		error("output size mismatch for %s", zh.file);
 	if(zh.csize != rlen)
 		error("input size mismatch for %s", zh.file);
 
 	delfile = nil;
 	free(zh.file);
 
 	if(fd >= 0 && !stdout){
 		if(settimes){
 			d = dirfstat(fd);
 			if(d != nil){
 				d->mtime = msdos2time(zh.modtime, zh.moddate);
 				if(d->mtime)
 					dirfwstat(fd, d);
 			}
 		}
 		close(fd);
 	}
 
 	return ok;
 }
 
 static int
 wantFile(char *file)
 {
 	int i, n;
 
 	if(nwant == 0)
 		return 1;
 	for(i = 0; i < nwant; i++){
 		if(strcmp(want[i], file) == 0)
 			return 1;
 		n = strlen(want[i]);
 		if(strncmp(want[i], file, n) == 0 && file[n] == '/')
 			return 1;
 	}
 	return 0;
 }
 
 /*
  * find the start of the central directory
  * returns the number of entries in the directory,
  * or -1 if there was an error
  */
 static int
 findCDir(Biobuf *bin, char *file)
 {
 	vlong ecoff;
 	long off, size;
 	int entries, zclen, dn, ds, de;
 
 	ecoff = Bseek(bin, -ZECHeadSize, 2);
 	if(ecoff < 0){
 		fprint(2, "unzip: can't seek to contents of %s; try adding -s\n", file);
 		return -1;
 	}
 	if(setjmp(zjmp))
 		return -1;
 
 	if(get4(bin) != ZECHeader){
 		fprint(2, "unzip: bad magic number for contents of %s\n", file);
 		return -1;
 	}
 	dn = get2(bin);
 	ds = get2(bin);
 	de = get2(bin);
 	entries = get2(bin);
 	size = get4(bin);
 	off = get4(bin);
 	zclen = get2(bin);
 	while(zclen-- > 0)
 		get1(bin);
 
 	if(verbose > 1){
 		print("table starts at %ld for %ld bytes\n", off, size);
 		if(ecoff - size != off)
 			print("\ttable should start at %lld-%ld=%lld\n", ecoff, size, ecoff-size);
 		if(dn || ds || de != entries)
 			print("\tcurrent disk=%d start disk=%d table entries on this disk=%d\n", dn, ds, de);
 	}
 
 	if(Bseek(bin, off, 0) != off){
 		fprint(2, "unzip: can't seek to start of contents of %s\n", file);
 		return -1;
 	}
 
 	return entries;
 }
 
 static int
 cheader(Biobuf *bin, ZipHead *zh)
 {
 	u32int v;
 	int flen, xlen, fclen;
 
 	v = get4(bin);
 	if(v != ZCHeader){
 		if(v == ZECHeader)
 			return 0;
 		error("bad magic number %lux", v);
 	}
 	zh->madevers = get1(bin);
 	zh->madeos = get1(bin);
 	zh->extvers = get1(bin);
 	zh->extos = get1(bin);
 	zh->flags = get2(bin);
 	zh->meth = get2(bin);
 	zh->modtime = get2(bin);
 	zh->moddate = get2(bin);
 	zh->crc = get4(bin);
 	zh->csize = get4(bin);
 	zh->uncsize = get4(bin);
 	flen = get2(bin);
 	xlen = get2(bin);
 	fclen = get2(bin);
 	get2(bin);		/* disk number start */
 	zh->iattr = get2(bin);
 	zh->eattr = get4(bin);
 	zh->off = get4(bin);
 
 	zh->file = getname(bin, flen);
 
 	while(xlen-- > 0)
 		get1(bin);
 
 	while(fclen-- > 0)
 		get1(bin);
 
 	return 1;
 }
 
 static int
 header(Biobuf *bin, ZipHead *zh)
 {
 	u32int v;
 	int flen, xlen;
 
 	v = get4(bin);
 	if(v != ZHeader){
 		if(v == ZCHeader)
 			return 0;
 		error("bad magic number %lux at %lld", v, Boffset(bin)-4);
 	}
 	zh->extvers = get1(bin);
 	zh->extos = get1(bin);
 	zh->flags = get2(bin);
 	zh->meth = get2(bin);
 	zh->modtime = get2(bin);
 	zh->moddate = get2(bin);
 	zh->crc = get4(bin);
 	zh->csize = get4(bin);
 	zh->uncsize = get4(bin);
 	flen = get2(bin);
 	xlen = get2(bin);
 
 	zh->file = getname(bin, flen);
 
 	while(xlen-- > 0)
 		get1(bin);
 
 	return 1;
 }
 
 static void
 trailer(Biobuf *bin, ZipHead *zh)
 {
 	if(zh->flags & ZTrailInfo){
 		zh->crc = get4(bin);
 		zh->csize = get4(bin);
 		zh->uncsize = get4(bin);
 	}
 }
 
 static char*
 getname(Biobuf *bin, int len)
 {
 	char *s;
 	int i, c;
 
 	s = emalloc(len + 1);
 	for(i = 0; i < len; i++){
 		c = get1(bin);
 		if(lower)
 			c = tolower(c);
 		s[i] = c;
 	}
 	s[i] = '\0';
 	return s;
 }
 
 static int
 crcwrite(void *out, void *buf, int n)
 {
 	int fd, nw;
 
 	wlen += n;
 	crc = blockcrc(crctab, crc, buf, n);
 	fd = (int)(uintptr)out;
 	if(fd < 0)
 		return n;
 	nw = write(fd, buf, n);
 	if(nw != n)
 		wbad = 1;
 	return nw;
 }
 
 static int
 copyout(int ofd, Biobuf *bin, long len)
 {
 	char buf[BufSize];
 	int n;
 
 	for(; len > 0; len -= n){
 		n = len;
 		if(n > BufSize)
 			n = BufSize;
 		n = Bread(bin, buf, n);
 		if(n <= 0)
 			return 0;
 		rlen += n;
 		if(crcwrite((void*)(uintptr)ofd, buf, n) != n)
 			return 0;
 	}
 	return 1;
 }
 
 static u32int
 get4(Biobuf *b)
 {
 	u32int v;
 	int i, c;
 
 	v = 0;
 	for(i = 0; i < 4; i++){
 		c = Bgetc(b);
 		if(c < 0)
 			error("unexpected eof reading file information");
 		v |= c << (i * 8);
 	}
 	return v;
 }
 
 static int
 get2(Biobuf *b)
 {
 	int i, c, v;
 
 	v = 0;
 	for(i = 0; i < 2; i++){
 		c = Bgetc(b);
 		if(c < 0)
 			error("unexpected eof reading file information");
 		v |= c << (i * 8);
 	}
 	return v;
 }
 
 static int
 get1(Biobuf *b)
 {
 	int c;
 
 	c = Bgetc(b);
 	if(c < 0)
 		error("unexpected eof reading file information");
 	return c;
 }
 
 static long
 msdos2time(int time, int date)
 {
 	Tm tm;
 
 	tm.hour = time >> 11;
 	tm.min = (time >> 5) & 63;
 	tm.sec = (time & 31) << 1;
 	tm.year = 80 + (date >> 9);
 	tm.mon = ((date >> 5) & 15) - 1;
 	tm.mday = date & 31;
 	tm.zone[0] = '\0';
 	tm.yday = 0;
 
 	return tm2sec(&tm);
 }
 
 static void*
 emalloc(u32int n)
 {
 	void *p;
 
 	p = malloc(n);
 	if(p == nil)
 		sysfatal("out of memory");
 	return p;
 }
 
 static void
 error(char *fmt, ...)
 {
 	va_list arg;
 
 	fprint(2, "unzip: ");
 	va_start(arg, fmt);
 	vfprint(2, fmt, arg);
 	va_end(arg);
 	fprint(2, "\n");
 
 	if(delfile != nil){
 		fprint(2, "unzip: removing output file %s\n", delfile);
 		remove(delfile);
 		delfile = nil;
 	}
 
 	longjmp(zjmp, 1);
 }