Move magic number checking into main.c and make it work when

decompressing from a pipe.  Currently assumes that magic numbers
are 2 bytes but this is relatively easy to change as needed in the
future.  Discussed w/ mickey@

4 files changed, 58 insertions, 75 deletions

diff --git a/usr.bin/compress/compress.h b/usr.bin/compress/compress.h
index a5c3a72fa38..b9ce25d7ca2 100644
--- a/usr.bin/compress/compress.h
+++ b/usr.bin/compress/compress.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: compress.h,v 1.4 2003/06/03 21:08:36 mickey Exp $	*/
+/*	$OpenBSD: compress.h,v 1.5 2003/07/11 02:31:18 millert Exp $	*/
 
 /*
  * Copyright (c) 1997 Michael Shalayeff
@@ -37,21 +37,21 @@ extern const char main_rcsid[], z_rcsid[], gz_rcsid[], pkzip_rcsid[],
     pack_rcsid[], lzh_rcsid[];
 
 extern int z_check_header(int, struct stat *, const char *);
-extern void *z_open(int, const char *, int);
+extern void *z_open(int, const char *, int, int);
 extern FILE *zopen(const char *, const char *,int);
 extern int zread(void *, char *, int);
 extern int zwrite(void *, const char *, int);
 extern int zclose(void *);
 
 extern int gz_check_header(int, struct stat *, const char *);
-extern void *gz_open(int, const char *, int);
+extern void *gz_open(int, const char *, int, int);
 extern int gz_read(void *, char *, int);
 extern int gz_write(void *, const char *, int);
 extern int gz_close(void *);
 extern int gz_flush(void *, int);
 
 extern int lzh_check_header(int, struct stat *, const char *);
-extern void *lzh_open(int, const char *, int);
+extern void *lzh_open(int, const char *, int, int);
 extern int lzh_read(void *, char *, int);
 extern int lzh_write(void *, const char *, int);
 extern int lzh_close(void *);
diff --git a/usr.bin/compress/gzopen.c b/usr.bin/compress/gzopen.c
index b73ed5d2422..c7c9e203ad3 100644
--- a/usr.bin/compress/gzopen.c
+++ b/usr.bin/compress/gzopen.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gzopen.c,v 1.11 2003/07/10 00:06:50 david Exp $	*/
+/*	$OpenBSD: gzopen.c,v 1.12 2003/07/11 02:31:18 millert Exp $	*/
 
 /*
  * Copyright (c) 1997 Michael Shalayeff
@@ -59,7 +59,7 @@
 */
 
 const char gz_rcsid[] =
-    "$OpenBSD: gzopen.c,v 1.11 2003/07/10 00:06:50 david Exp $";
+    "$OpenBSD: gzopen.c,v 1.12 2003/07/11 02:31:18 millert Exp $";
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -97,26 +97,11 @@ static const u_char gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
 
 static int put_int32(gz_stream *, u_int32_t);
 static u_int32_t get_int32(gz_stream *);
-static int get_header(gz_stream *);
+static int get_header(gz_stream *, int);
 static int get_byte(gz_stream *);
 
-int
-gz_check_header(int fd, struct stat *sb, const char *ofn)
-{
-	int f;
-	u_char buf[sizeof(gz_magic)];
-	off_t off = lseek(fd, 0, SEEK_CUR);
-
-	f = (read(fd, buf, sizeof(buf)) == sizeof(buf) &&
-	    !memcmp(buf, gz_magic, sizeof(buf)));
-
-	lseek (fd, off, SEEK_SET);
-
-	return f;
-}
-
 void *
-gz_open(int fd, const char *mode, int bits)
+gz_open(int fd, const char *mode, int bits, int gotmagic)
 {
 	gz_stream *s;
 
@@ -177,7 +162,7 @@ gz_open(int fd, const char *mode, int bits)
 			s = NULL;
 		}
 	} else {
-		if (get_header(s) != 0) { /* skip the .gz header */
+		if (get_header(s, gotmagic) != 0) { /* skip the .gz header */
 			gz_close (s);
 			s = NULL;
 		}
@@ -297,7 +282,7 @@ get_int32(gz_stream *s)
 }
 
 static int
-get_header(gz_stream *s)
+get_header(gz_stream *s, int gotmagic)
 {
 	int method; /* method byte */
 	int flags;  /* flags byte */
@@ -305,11 +290,13 @@ get_header(gz_stream *s)
 	int c;
 
 	/* Check the gzip magic header */
-	for (len = 0; len < 2; len++) {
-		c = get_byte(s);
-		if (c != gz_magic[len]) {
-			errno = EFTYPE;
-			return -1;
+	if (!gotmagic) {
+		for (len = 0; len < 2; len++) {
+			c = get_byte(s);
+			if (c != gz_magic[len]) {
+				errno = EFTYPE;
+				return -1;
+			}
 		}
 	}
 
diff --git a/usr.bin/compress/main.c b/usr.bin/compress/main.c
index 3238f738a51..dfdfbb9f712 100644
--- a/usr.bin/compress/main.c
+++ b/usr.bin/compress/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.32 2003/07/08 00:30:12 mickey Exp $	*/
+/*	$OpenBSD: main.c,v 1.33 2003/07/11 02:31:18 millert Exp $	*/
 
 static const char copyright[] =
 "@(#) Copyright (c) 1992, 1993\n\
@@ -35,7 +35,7 @@ static const char license[] =
 #if 0
 static char sccsid[] = "@(#)compress.c	8.2 (Berkeley) 1/7/94";
 #else
-static const char main_rcsid[] = "$OpenBSD: main.c,v 1.32 2003/07/08 00:30:12 mickey Exp $";
+static const char main_rcsid[] = "$OpenBSD: main.c,v 1.33 2003/07/11 02:31:18 millert Exp $";
 #endif
 #endif /* not lint */
 
@@ -65,23 +65,23 @@ extern char *__progname;
 const struct compressor {
 	char *name;
 	char *suffix;
-	int (*check_header)(int, struct stat *, const char *);
-	void *(*open)(int, const char *, int);
+	u_char *magic;
+	void *(*open)(int, const char *, int, int);
 	int (*read)(void *, char *, int);
 	int (*write)(void *, const char *, int);
 	int (*close)(void *);
 } c_table[] = {
 #define M_COMPRESS (&c_table[0])
-  { "compress", ".Z", z_check_header,  z_open,  zread,   zwrite,   zclose },
+  { "compress", ".Z", "\037\235", z_open,  zread,   zwrite,   zclose },
 #define M_DEFLATE (&c_table[1])
-  { "deflate", ".gz", gz_check_header, gz_open, gz_read, gz_write, gz_close },
+  { "deflate", ".gz", "\037\213", gz_open, gz_read, gz_write, gz_close },
 #if 0
 #define M_LZH (&c_table[2])
-  { "lzh", ".lzh", lzh_check_header, lzh_open, lzh_read, lzh_write, lzh_close },
+  { "lzh", ".lzh", "\037\240", lzh_open, lzh_read, lzh_write, lzh_close },
 #define M_ZIP (&c_table[3])
-  { "zip", ".zip", zip_check_header, zip_open, zip_read, zip_write, zip_close },
+  { "zip", ".zip", "PK", zip_open, zip_read, zip_write, zip_close },
 #define M_PACK (&c_table[4])
-  { "pack", ".pak",pak_check_header, pak_open, pak_read, pak_write, pak_close },
+  { "pack", ".pak", "\037\036", pak_open, pak_read, pak_write, pak_close },
 #endif
   { NULL }
 };
@@ -464,7 +464,7 @@ compress(const char *in, const char *out, const struct compressor *method,
 		return (-1);
 	}
 
-	if ((cookie = (*method->open)(ofd, "w", bits)) == NULL) {
+	if ((cookie = (*method->open)(ofd, "w", bits, 0)) == NULL) {
 		if (verbose >= 0)
 			warn("%s", in);
 		(void) close(ofd);
@@ -505,16 +505,16 @@ const struct compressor *
 check_method(int fd, struct stat *sb, const char *out)
 {
 	const struct compressor *method;
-
-	for (method = &c_table[0];
-	    method->name != NULL && !(*method->check_header)(fd, sb, out);
-	    method++)
-		;
-
-	if (method->name == NULL)
-		method = NULL;
-
-	return (method);
+	u_char magic[2];
+
+	if (read(fd, magic, sizeof(magic)) != 2)
+		return (NULL);
+	for (method = &c_table[0]; method->name != NULL; method++) {
+		if (magic[0] == method->magic[0] &&
+		    magic[1] == method->magic[1])
+			return (method);
+	}
+	return (NULL);
 }
 
 int
@@ -543,14 +543,14 @@ decompress(const char *in, const char *out, const struct compressor *method,
 		return -1;
 	}
 
-	if (!pipin && (method = check_method(ifd, sb, out)) == NULL) {
+	if ((method = check_method(ifd, sb, out)) == NULL) {
 		if (verbose >= 0)
 			warnx("%s: unrecognized file format", in);
 		close (ifd);
 		return -1;
 	}
 
-	if ((cookie = (*method->open)(ifd, "r", bits)) == NULL) {
+	if ((cookie = (*method->open)(ifd, "r", bits, 1)) == NULL) {
 		if (verbose >= 0)
 			warn("%s", in);
 		error++;
diff --git a/usr.bin/compress/zopen.c b/usr.bin/compress/zopen.c
index 24cfab4b5ab..9b26edcb206 100644
--- a/usr.bin/compress/zopen.c
+++ b/usr.bin/compress/zopen.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: zopen.c,v 1.11 2003/06/22 15:22:43 deraadt Exp $	*/
+/*	$OpenBSD: zopen.c,v 1.12 2003/07/11 02:31:18 millert Exp $	*/
 /*	$NetBSD: zopen.c,v 1.5 1995/03/26 09:44:53 glass Exp $	*/
 
 /*-
@@ -40,7 +40,7 @@
 static char sccsid[] = "@(#)zopen.c	8.1 (Berkeley) 6/27/93";
 #else
 const char z_rcsid[] =
-	"$OpenBSD: zopen.c,v 1.11 2003/06/22 15:22:43 deraadt Exp $";
+	"$OpenBSD: zopen.c,v 1.12 2003/07/11 02:31:18 millert Exp $";
 #endif
 
 /*-
@@ -104,7 +104,7 @@ struct s_zstate {
 	int zs_fd;			/* File stream for I/O */
 	char zs_mode;			/* r or w */
 	enum {
-		S_START, S_MIDDLE, S_EOF
+		S_START, S_MAGIC, S_MIDDLE, S_EOF
 	} zs_state;			/* State of computation */
 	int zs_n_bits;			/* Number of bits/code. */
 	int zs_maxbits;			/* User settable max # bits/code. */
@@ -227,6 +227,8 @@ zwrite(void *cookie, const char *wbp, int num)
 	count = num;
 	bp = (u_char *)wbp;
 	switch (zs->zs_state) {
+	case S_MAGIC:
+		return -1;
 	case S_EOF:
 		return 0;
 	case S_START:
@@ -468,6 +470,16 @@ zread(void *cookie, char *rbp, int num)
 	case S_START:
 		zs->zs_state = S_MIDDLE;
 		zs->zs_bp = zs->zs_buf;
+		header[0] = header[1] = header[2] = '\0';
+		read(zs->zs_fd, header, sizeof(header));
+		break;
+	case S_MAGIC:
+		zs->zs_state = S_MIDDLE;
+		zs->zs_bp = zs->zs_buf;
+		header[0] = z_magic[0];
+		header[1] = z_magic[1];
+		header[2] = '\0';
+		read(zs->zs_fd, &header[2], 1);
 		break;
 	case S_MIDDLE:
 		goto middle;
@@ -476,8 +488,7 @@ zread(void *cookie, char *rbp, int num)
 	}
 
 	/* Check the magic number */
-	if (read(zs->zs_fd, header, sizeof(header)) != sizeof(header) ||
-	    memcmp(header, z_magic, sizeof(z_magic)) != 0) {
+	if (header[0] != z_magic[0] || header[1] != z_magic[1]) {
 		errno = EFTYPE;
 		return (-1);
 	}
@@ -706,7 +717,7 @@ zopen(const char *name, const char *mode, int bits)
 	if ((fd = open(name, (*mode=='r'? O_RDONLY:O_WRONLY|O_CREAT),
 	    S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) == -1)
 		return NULL;
-	if ((cookie = z_open(fd, mode, bits)) == NULL) {
+	if ((cookie = z_open(fd, mode, bits, 0)) == NULL) {
 		close(fd);
 		return NULL;
 	}
@@ -715,7 +726,7 @@ zopen(const char *name, const char *mode, int bits)
 }
 
 void *
-z_open(int fd, const char *mode, int bits)
+z_open(int fd, const char *mode, int bits, int gotmagic)
 {
 	struct s_zstate *zs;
 
@@ -740,7 +751,7 @@ z_open(int fd, const char *mode, int bits)
 	zs->zs_checkpoint = CHECK_GAP;
 	zs->zs_in_count = 1;		/* Length of input. */
 	zs->zs_out_count = 0;		/* # of codes output (for debugging).*/
-	zs->zs_state = S_START;
+	zs->zs_state = gotmagic ? S_MAGIC : S_START;
 	zs->zs_offset = 0;
 	zs->zs_size = 0;
 	zs->zs_mode = mode[0];
@@ -749,18 +760,3 @@ z_open(int fd, const char *mode, int bits)
 	zs->zs_fd = fd;
 	return zs;
 }
-
-int
-z_check_header(int fd, struct stat *sb, const char *ofn)
-{
-	int f;
-	u_char buf[sizeof(z_magic)];
-	off_t off = lseek(fd, 0, SEEK_CUR);
-
-	f = (read(fd, buf, sizeof(buf)) == sizeof(buf) &&
-	    !memcmp(buf, z_magic, sizeof(buf)));
-
-	lseek (fd, off, SEEK_SET);
-
-	return f;
-}