X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=archival%2Ftar.c;h=03d66a6929e9e8b2dc8ecca730c6039c0c162d11;hb=8b814b4a349e2262c0ad25793b05206a14651ebb;hp=99c4adb6a2fee01523b0a0b5cce60b99995828d9;hpb=4fbb584a0e6ee086d6b30936c7124c687b3e977f;p=oweals%2Fbusybox.git

diff --git a/archival/tar.c b/archival/tar.c
index 99c4adb6a..03d66a692 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -3,7 +3,7 @@
  * Mini tar implementation for busybox
  *
  * Modified to use common extraction code used by ar, cpio, dpkg-deb, dpkg
- *  Glenn McGrath <bug1@iinet.net.au>
+ *  by Glenn McGrath
  *
  * Note, that as of BusyBox-0.43, tar has been completely rewritten from the
  * ground up.  It still has remnants of the old code lying about, but it is
@@ -23,12 +23,27 @@
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
-#include "busybox.h"
-#include "unarchive.h"
 #include <fnmatch.h>
-#include <getopt.h>
+#include "libbb.h"
+#include "unarchive.h"
+
+/* FIXME: Stop using this non-standard feature */
+#ifndef FNM_LEADING_DIR
+#define FNM_LEADING_DIR 0
+#endif
 
-#ifdef CONFIG_FEATURE_TAR_CREATE
+
+#define block_buf bb_common_bufsiz1
+
+
+#if !ENABLE_FEATURE_SEAMLESS_GZ && !ENABLE_FEATURE_SEAMLESS_BZ2
+/* Do not pass gzip flag to writeTarFile() */
+#define writeTarFile(tar_fd, verboseFlag, dereferenceFlag, include, exclude, gzip) \
+	writeTarFile(tar_fd, verboseFlag, dereferenceFlag, include, exclude)
+#endif
+
+
+#if ENABLE_FEATURE_TAR_CREATE
 
 /* Tar file constants  */
 
@@ -37,6 +52,7 @@
 /* POSIX tar Header Block, from POSIX 1003.1-1990  */
 #define NAME_SIZE      100
 #define NAME_SIZE_STR "100"
+typedef struct TarHeader TarHeader;
 struct TarHeader {		  /* byte offset */
 	char name[NAME_SIZE];     /*   0-99 */
 	char mode[8];             /* 100-107 */
@@ -47,16 +63,19 @@ struct TarHeader {		  /* byte offset */
 	char chksum[8];           /* 148-155 */
 	char typeflag;            /* 156-156 */
 	char linkname[NAME_SIZE]; /* 157-256 */
-	char magic[6];            /* 257-262 */
-	char version[2];          /* 263-264 */
+	/* POSIX:   "ustar" NUL "00" */
+	/* GNU tar: "ustar  " NUL */
+	/* Normally it's defined as magic[6] followed by
+	 * version[2], but we put them together to save code.
+	 */
+	char magic[8];            /* 257-264 */
 	char uname[32];           /* 265-296 */
 	char gname[32];           /* 297-328 */
 	char devmajor[8];         /* 329-336 */
 	char devminor[8];         /* 337-344 */
 	char prefix[155];         /* 345-499 */
-	char padding[12];         /* 500-512 (pad to exactly the TAR_BLOCK_SIZE) */
+	char padding[12];         /* 500-512 (pad to exactly TAR_BLOCK_SIZE) */
 };
-typedef struct TarHeader TarHeader;
 
 /*
 ** writeTarFile(), writeFileToTarball(), and writeTarHeader() are
@@ -65,27 +84,27 @@ typedef struct TarHeader TarHeader;
 */
 typedef struct HardLinkInfo HardLinkInfo;
 struct HardLinkInfo {
-	HardLinkInfo *next;	/* Next entry in list */
-	dev_t dev;			/* Device number */
-	ino_t ino;			/* Inode number */
-	short linkCount;	/* (Hard) Link Count */
-	char name[1];		/* Start of filename (must be last) */
+	HardLinkInfo *next;     /* Next entry in list */
+	dev_t dev;              /* Device number */
+	ino_t ino;              /* Inode number */
+	short linkCount;        /* (Hard) Link Count */
+	char name[1];           /* Start of filename (must be last) */
 };
 
 /* Some info to be carried along when creating a new tarball */
+typedef struct TarBallInfo TarBallInfo;
 struct TarBallInfo {
-	int tarFd;				/* Open-for-write file descriptor
-							   for the tarball */
-	struct stat statBuf;	/* Stat info for the tarball, letting
-							   us know the inode and device that the
-							   tarball lives, so we can avoid trying
-							   to include the tarball into itself */
-	int verboseFlag;		/* Whether to print extra stuff or not */
-	const llist_t *excludeList;	/* List of files to not include */
-	HardLinkInfo *hlInfoHead;	/* Hard Link Tracking Information */
-	HardLinkInfo *hlInfo;	/* Hard Link Info for the current file */
+	int tarFd;                      /* Open-for-write file descriptor
+	                                 * for the tarball */
+	struct stat statBuf;            /* Stat info for the tarball, letting
+	                                 * us know the inode and device that the
+	                                 * tarball lives, so we can avoid trying
+	                                 * to include the tarball into itself */
+	int verboseFlag;                /* Whether to print extra stuff or not */
+	const llist_t *excludeList;     /* List of files to not include */
+	HardLinkInfo *hlInfoHead;       /* Hard Link Tracking Information */
+	HardLinkInfo *hlInfo;           /* Hard Link Info for the current file */
 };
-typedef struct TarBallInfo TarBallInfo;
 
 /* A nice enum with all the possible tar file content types */
 enum TarFileType {
@@ -104,7 +123,7 @@ enum TarFileType {
 typedef enum TarFileType TarFileType;
 
 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
-static void addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr,
+static void addHardLinkInfo(HardLinkInfo **hlInfoHeadPtr,
 					struct stat *statbuf,
 					const char *fileName)
 {
@@ -120,7 +139,7 @@ static void addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr,
 	strcpy(hlInfo->name, fileName);
 }
 
-static void freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)
+static void freeHardLinkInfo(HardLinkInfo **hlInfoHeadPtr)
 {
 	HardLinkInfo *hlInfo;
 	HardLinkInfo *hlInfoNext;
@@ -134,11 +153,10 @@ static void freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)
 		}
 		*hlInfoHeadPtr = NULL;
 	}
-	return;
 }
 
 /* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
-static HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, struct stat *statbuf)
+static HardLinkInfo *findHardLinkInfo(HardLinkInfo *hlInfo, struct stat *statbuf)
 {
 	while (hlInfo) {
 		if ((statbuf->st_ino == hlInfo->ino) && (statbuf->st_dev == hlInfo->dev))
@@ -150,39 +168,94 @@ static HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, struct stat *statbu
 
 /* Put an octal string into the specified buffer.
  * The number is zero padded and possibly null terminated.
- * Returns TRUE if successful. - DISABLED (no caller ever checked)  */
-static void putOctal(char *cp, int len, long long value)
+ * Stores low-order bits only if whole value does not fit. */
+static void putOctal(char *cp, int len, off_t value)
 {
-	int tempLength;
-	/* long long for the sake of storing lengths of 4Gb+ files */
-	/* (we are bust anyway after 64Gb: it doesn't fit into the field) */
-	char tempBuffer[sizeof(long long)*3+1];
+	char tempBuffer[sizeof(off_t)*3+1];
 	char *tempString = tempBuffer;
+	int width;
 
-	/* Create a string of the specified length with
-	 * leading zeroes and the octal number, and a trailing null.  */
-	tempLength = sprintf(tempBuffer, "%0*llo", len - 1, value);
-
-	/* If the string is too large, suppress leading 0's.  */
-	/* If that is not enough, drop trailing null.  */
-	tempLength -= len; /* easier to do checks */
-	while (tempLength >= 0) {
-		if (tempString[0] != '0') {
-			if (!tempLength) {
-				/* 1234 barely fits in 4 chars (w/o EOL '\0') */
-				break;
-			}
-			/* 12345 doesn't fit into 4 chars */
-			return /*FALSE*/;
-		}
-		tempLength--; /* still have leading '0', */
-		tempString++; /* can afford to drop it but retain EOL '\0' */
-	}
+	width = sprintf(tempBuffer, "%0*"OFF_FMT"o", len, value);
+	tempString += (width - len);
+
+	/* If string has leading zeroes, we can drop one */
+	/* and field will have trailing '\0' */
+	/* (increases chances of compat with other tars) */
+	if (tempString[0] == '0')
+		tempString++;
 
-	/* Copy the string to the field.  */
+	/* Copy the string to the field */
 	memcpy(cp, tempString, len);
-	/*return TRUE;*/
 }
+#define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b))
+
+static void chksum_and_xwrite(int fd, struct TarHeader* hp)
+{
+	/* POSIX says that checksum is done on unsigned bytes
+	 * (Sun and HP-UX gets it wrong... more details in
+	 * GNU tar source) */
+	const unsigned char *cp;
+	int chksum, size;
+
+	strcpy(hp->magic, "ustar  ");
+
+	/* Calculate and store the checksum (i.e., the sum of all of the bytes of
+	 * the header).  The checksum field must be filled with blanks for the
+	 * calculation.  The checksum field is formatted differently from the
+	 * other fields: it has 6 digits, a null, then a space -- rather than
+	 * digits, followed by a null like the other fields... */
+	memset(hp->chksum, ' ', sizeof(hp->chksum));
+	cp = (const unsigned char *) hp;
+	chksum = 0;
+	size = sizeof(*hp);
+	do { chksum += *cp++; } while (--size);
+	putOctal(hp->chksum, sizeof(hp->chksum)-1, chksum);
+
+	/* Now write the header out to disk */
+	xwrite(fd, hp, sizeof(*hp));
+}
+
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+static void writeLongname(int fd, int type, const char *name, int dir)
+{
+	static const struct {
+		char mode[8];             /* 100-107 */
+		char uid[8];              /* 108-115 */
+		char gid[8];              /* 116-123 */
+		char size[12];            /* 124-135 */
+		char mtime[12];           /* 136-147 */
+	} prefilled = {
+		"0000000",
+		"0000000",
+		"0000000",
+		"00000000000",
+		"00000000000",
+	};
+	struct TarHeader header;
+	int size;
+
+	dir = !!dir; /* normalize: 0/1 */
+	size = strlen(name) + 1 + dir; /* GNU tar uses strlen+1 */
+	/* + dir: account for possible '/' */
+
+	memset(&header, 0, sizeof(header));
+	strcpy(header.name, "././@LongLink");
+	memcpy(header.mode, prefilled.mode, sizeof(prefilled));
+	PUT_OCTAL(header.size, size);
+	header.typeflag = type;
+	chksum_and_xwrite(fd, &header);
+
+	/* Write filename[/] and pad the block. */
+	/* dir=0: writes 'name<NUL>', pads */
+	/* dir=1: writes 'name', writes '/<NUL>', pads */
+	dir *= 2;
+	xwrite(fd, name, size - dir);
+	xwrite(fd, "/", dir);
+	size = (-size) & (TAR_BLOCK_SIZE-1);
+	memset(&header, 0, size);
+	xwrite(fd, &header, size);
+}
+#endif
 
 /* Write out a tar header for the specified file/directory/whatever */
 void BUG_tar_header_size(void);
@@ -190,109 +263,114 @@ static int writeTarHeader(struct TarBallInfo *tbInfo,
 		const char *header_name, const char *fileName, struct stat *statbuf)
 {
 	struct TarHeader header;
-	const unsigned char *cp;
-	int chksum;
-	int size;
 
 	if (sizeof(header) != 512)
 		BUG_tar_header_size();
 
-	bzero(&header, sizeof(struct TarHeader));
+	memset(&header, 0, sizeof(struct TarHeader));
 
-	safe_strncpy(header.name, header_name, sizeof(header.name));
+	strncpy(header.name, header_name, sizeof(header.name));
 
 	/* POSIX says to mask mode with 07777. */
-	putOctal(header.mode, sizeof(header.mode), statbuf->st_mode & 07777);
-	putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
-	putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
-	if (sizeof(header.size) != sizeof("00000000000"))
-		BUG_tar_header_size();
-	strcpy(header.size, "00000000000"); /* Regular file size is handled later */
-	putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
-	strcpy(header.magic, "ustar  ");
+	PUT_OCTAL(header.mode, statbuf->st_mode & 07777);
+	PUT_OCTAL(header.uid, statbuf->st_uid);
+	PUT_OCTAL(header.gid, statbuf->st_gid);
+	memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */
+	PUT_OCTAL(header.mtime, statbuf->st_mtime);
 
-	/* Enter the user and group names (default to root if it fails) */
-//cache!!!
-	if (bb_getpwuid(header.uname, statbuf->st_uid, sizeof(header.uname)) == NULL)
-		strcpy(header.uname, "root");
-	if (bb_getgrgid(header.gname, statbuf->st_gid, sizeof(header.gname)) == NULL)
-		strcpy(header.gname, "root");
+	/* Enter the user and group names */
+	safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname));
+	safe_strncpy(header.gname, get_cached_groupname(statbuf->st_gid), sizeof(header.gname));
 
 	if (tbInfo->hlInfo) {
 		/* This is a hard link */
 		header.typeflag = LNKTYPE;
 		strncpy(header.linkname, tbInfo->hlInfo->name,
 				sizeof(header.linkname));
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+		/* Write out long linkname if needed */
+		if (header.linkname[sizeof(header.linkname)-1])
+			writeLongname(tbInfo->tarFd, GNULONGLINK,
+					tbInfo->hlInfo->name, 0);
+#endif
 	} else if (S_ISLNK(statbuf->st_mode)) {
-		char *lpath = xreadlink(fileName);
-		if (!lpath)		/* Already printed err msg inside xreadlink() */
+		char *lpath = xmalloc_readlink_or_warn(fileName);
+		if (!lpath)
 			return FALSE;
 		header.typeflag = SYMTYPE;
 		strncpy(header.linkname, lpath, sizeof(header.linkname));
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+		/* Write out long linkname if needed */
+		if (header.linkname[sizeof(header.linkname)-1])
+			writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0);
+#else
 		/* If it is larger than 100 bytes, bail out */
-		if (header.linkname[sizeof(header.linkname)-1] /* at least 100? */
-		 && lpath[sizeof(header.linkname)] /* and 101th is also not zero */
-		) {
+		if (header.linkname[sizeof(header.linkname)-1]) {
 			free(lpath);
 			bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
 			return FALSE;
 		}
+#endif
 		free(lpath);
 	} else if (S_ISDIR(statbuf->st_mode)) {
 		header.typeflag = DIRTYPE;
-		strncat(header.name, "/", sizeof(header.name));
+		/* Append '/' only if there is a space for it */
+		if (!header.name[sizeof(header.name)-1])
+			header.name[strlen(header.name)] = '/';
 	} else if (S_ISCHR(statbuf->st_mode)) {
 		header.typeflag = CHRTYPE;
-		putOctal(header.devmajor, sizeof(header.devmajor),
-				 major(statbuf->st_rdev));
-		putOctal(header.devminor, sizeof(header.devminor),
-				 minor(statbuf->st_rdev));
+		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
+		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
 	} else if (S_ISBLK(statbuf->st_mode)) {
 		header.typeflag = BLKTYPE;
-		putOctal(header.devmajor, sizeof(header.devmajor),
-				 major(statbuf->st_rdev));
-		putOctal(header.devminor, sizeof(header.devminor),
-				 minor(statbuf->st_rdev));
+		PUT_OCTAL(header.devmajor, major(statbuf->st_rdev));
+		PUT_OCTAL(header.devminor, minor(statbuf->st_rdev));
 	} else if (S_ISFIFO(statbuf->st_mode)) {
 		header.typeflag = FIFOTYPE;
 	} else if (S_ISREG(statbuf->st_mode)) {
+		if (sizeof(statbuf->st_size) > 4
+		 && statbuf->st_size > (off_t)0777777777777LL
+		) {
+			bb_error_msg_and_die("cannot store file '%s' "
+				"of size %"OFF_FMT"d, aborting",
+				fileName, statbuf->st_size);
+		}
 		header.typeflag = REGTYPE;
-		putOctal(header.size, sizeof(header.size), statbuf->st_size);
+		PUT_OCTAL(header.size, statbuf->st_size);
 	} else {
 		bb_error_msg("%s: unknown file type", fileName);
 		return FALSE;
 	}
 
-	/* Calculate and store the checksum (i.e., the sum of all of the bytes of
-	 * the header).  The checksum field must be filled with blanks for the
-	 * calculation.  The checksum field is formatted differently from the
-	 * other fields: it has [6] digits, a null, then a space -- rather than
-	 * digits, followed by a null like the other fields... */
-	memset(header.chksum, ' ', sizeof(header.chksum));
-	cp = (const unsigned char *) &header;
-	chksum = 0;
-	size = sizeof(struct TarHeader);
-	do { chksum += *cp++; } while (--size);
-	putOctal(header.chksum, sizeof(header.chksum)-1, chksum);
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+	/* Write out long name if needed */
+	/* (we, like GNU tar, output long linkname *before* long name) */
+	if (header.name[sizeof(header.name)-1])
+		writeLongname(tbInfo->tarFd, GNULONGNAME,
+				header_name, S_ISDIR(statbuf->st_mode));
+#endif
 
 	/* Now write the header out to disk */
-	xwrite(tbInfo->tarFd, &header, sizeof(struct TarHeader));
+	chksum_and_xwrite(tbInfo->tarFd, &header);
 
 	/* Now do the verbose thing (or not) */
-
 	if (tbInfo->verboseFlag) {
 		FILE *vbFd = stdout;
 
-		if (tbInfo->tarFd == STDOUT_FILENO)	/* If the archive goes to stdout, verbose to stderr */
+		/* If archive goes to stdout, verbose goes to stderr */
+		if (tbInfo->tarFd == STDOUT_FILENO)
 			vbFd = stderr;
-
-		fprintf(vbFd, "%s\n", header.name);
+		/* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */
+		/* We don't have such excesses here: for us "v" == "vv" */
+		/* '/' is probably a GNUism */
+		fprintf(vbFd, "%s%s\n", header_name,
+				S_ISDIR(statbuf->st_mode) ? "/" : "");
 	}
 
 	return TRUE;
 }
 
-# ifdef CONFIG_FEATURE_TAR_FROM
+#if ENABLE_FEATURE_TAR_FROM
 static int exclude_file(const llist_t *excluded_files, const char *file)
 {
 	while (excluded_files) {
@@ -315,17 +393,38 @@ static int exclude_file(const llist_t *excluded_files, const char *file)
 
 	return 0;
 }
-# else
+#else
 #define exclude_file(excluded_files, file) 0
-# endif
+#endif
 
-static int writeFileToTarball(const char *fileName, struct stat *statbuf,
-			void *userData, int depth)
+static int FAST_FUNC writeFileToTarball(const char *fileName, struct stat *statbuf,
+			void *userData, int depth UNUSED_PARAM)
 {
 	struct TarBallInfo *tbInfo = (struct TarBallInfo *) userData;
 	const char *header_name;
 	int inputFileFd = -1;
 
+	/* Strip leading '/' (must be before memorizing hardlink's name) */
+	header_name = fileName;
+	while (header_name[0] == '/') {
+		static smallint warned;
+
+		if (!warned) {
+			bb_error_msg("removing leading '/' from member names");
+			warned = 1;
+		}
+		header_name++;
+	}
+
+	if (header_name[0] == '\0')
+		return TRUE;
+
+	/* It is against the rules to archive a socket */
+	if (S_ISSOCK(statbuf->st_mode)) {
+		bb_error_msg("%s: socket ignored", fileName);
+		return TRUE;
+	}
+
 	/*
 	 * Check to see if we are dealing with a hard link.
 	 * If so -
@@ -337,52 +436,34 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf,
 	if (statbuf->st_nlink > 1) {
 		tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf);
 		if (tbInfo->hlInfo == NULL)
-			addHardLinkInfo(&tbInfo->hlInfoHead, statbuf, fileName);
-	}
-
-	/* It is against the rules to archive a socket */
-	if (S_ISSOCK(statbuf->st_mode)) {
-		bb_error_msg("%s: socket ignored", fileName);
-		return TRUE;
+			addHardLinkInfo(&tbInfo->hlInfoHead, statbuf, header_name);
 	}
 
 	/* It is a bad idea to store the archive we are in the process of creating,
 	 * so check the device and inode to be sure that this particular file isn't
 	 * the new tarball */
-	if (tbInfo->statBuf.st_dev == statbuf->st_dev &&
-		tbInfo->statBuf.st_ino == statbuf->st_ino) {
+	if (tbInfo->statBuf.st_dev == statbuf->st_dev
+	 && tbInfo->statBuf.st_ino == statbuf->st_ino
+	) {
 		bb_error_msg("%s: file is the archive; skipping", fileName);
 		return TRUE;
 	}
 
-	header_name = fileName;
-	while (header_name[0] == '/') {
-		static int alreadyWarned = FALSE;
-
-		if (alreadyWarned == FALSE) {
-			bb_error_msg("removing leading '/' from member names");
-			alreadyWarned = TRUE;
-		}
-		header_name++;
-	}
+	if (exclude_file(tbInfo->excludeList, header_name))
+		return SKIP;
 
-	if (strlen(fileName) >= NAME_SIZE) {
+#if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+	if (strlen(header_name) >= NAME_SIZE) {
 		bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
 		return TRUE;
 	}
-
-	if (header_name[0] == '\0')
-		return TRUE;
-
-	if (exclude_file(tbInfo->excludeList, header_name))
-		return SKIP;
+#endif
 
 	/* Is this a regular file? */
 	if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
 		/* open the file we want to archive, and make sure all is well */
-		inputFileFd = open(fileName, O_RDONLY);
+		inputFileFd = open_or_warn(fileName, O_RDONLY);
 		if (inputFileFd < 0) {
-			bb_perror_msg("%s: cannot open", fileName);
 			return FALSE;
 		}
 	}
@@ -394,43 +475,123 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf,
 
 	/* If it was a regular file, write out the body */
 	if (inputFileFd >= 0) {
-		off_t readSize = 0;
-
-		/* write the file to the archive */
-		readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
-		if (readSize != statbuf->st_size) {
-			/* Deadly. We record size into header first, */
-			/* and then write out file. If file shrinks in between, */
-			/* tar will be corrupted. So bail out. */
-			/* NB: GNU tar 1.16 warns and pads with zeroes */
-			/* or even seeks back and updates header */
-			bb_error_msg_and_die("short read from %s", fileName);
-		}
+		size_t readSize;
+		/* Write the file to the archive. */
+		/* We record size into header first, */
+		/* and then write out file. If file shrinks in between, */
+		/* tar will be corrupted. So we don't allow for that. */
+		/* NB: GNU tar 1.16 warns and pads with zeroes */
+		/* or even seeks back and updates header */
+		bb_copyfd_exact_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
+		////off_t readSize;
+		////readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size);
+		////if (readSize != statbuf->st_size && readSize >= 0) {
+		////	bb_error_msg_and_die("short read from %s, aborting", fileName);
+		////}
+
 		/* Check that file did not grow in between? */
-		/* if (safe_read(inputFileFd,1) == 1) warn but continue? */
+		/* if (safe_read(inputFileFd, 1) == 1) warn but continue? */
+
 		close(inputFileFd);
 
 		/* Pad the file up to the tar block size */
 		/* (a few tricks here in the name of code size) */
-		readSize = (-(int)readSize) & (TAR_BLOCK_SIZE-1);
-		bzero(bb_common_bufsiz1, readSize);
-		xwrite(tbInfo->tarFd, bb_common_bufsiz1, readSize);
+		readSize = (-(int)statbuf->st_size) & (TAR_BLOCK_SIZE-1);
+		memset(block_buf, 0, readSize);
+		xwrite(tbInfo->tarFd, block_buf, readSize);
 	}
 
 	return TRUE;
 }
 
-static int writeTarFile(const int tar_fd, const int verboseFlag,
-	const unsigned long dereferenceFlag, const llist_t *include,
-	const llist_t *exclude, const int gzip)
+#if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
+#if !(ENABLE_FEATURE_SEAMLESS_GZ && ENABLE_FEATURE_SEAMLESS_BZ2)
+#define vfork_compressor(tar_fd, gzip) vfork_compressor(tar_fd)
+#endif
+/* Don't inline: vfork scares gcc and pessimizes code */
+static void NOINLINE vfork_compressor(int tar_fd, int gzip)
+{
+	pid_t gzipPid;
+#if ENABLE_FEATURE_SEAMLESS_GZ && ENABLE_FEATURE_SEAMLESS_BZ2
+	const char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
+#elif ENABLE_FEATURE_SEAMLESS_GZ
+	const char *zip_exec = "gzip";
+#else /* only ENABLE_FEATURE_SEAMLESS_BZ2 */
+	const char *zip_exec = "bzip2";
+#endif
+	// On Linux, vfork never unpauses parent early, although standard
+	// allows for that. Do we want to waste bytes checking for it?
+#define WAIT_FOR_CHILD 0
+	volatile int vfork_exec_errno = 0;
+	struct fd_pair gzipDataPipe;
+#if WAIT_FOR_CHILD
+	struct fd_pair gzipStatusPipe;
+	xpiped_pair(gzipStatusPipe);
+#endif
+	xpiped_pair(gzipDataPipe);
+
+	signal(SIGPIPE, SIG_IGN); /* we only want EPIPE on errors */
+
+#if defined(__GNUC__) && __GNUC__
+	/* Avoid vfork clobbering */
+	(void) &zip_exec;
+#endif
+
+	gzipPid = vfork();
+	if (gzipPid < 0)
+		bb_perror_msg_and_die("vfork");
+
+	if (gzipPid == 0) {
+		/* child */
+		/* NB: close _first_, then move fds! */
+		close(gzipDataPipe.wr);
+#if WAIT_FOR_CHILD
+		close(gzipStatusPipe.rd);
+		/* gzipStatusPipe.wr will close only on exec -
+		 * parent waits for this close to happen */
+		fcntl(gzipStatusPipe.wr, F_SETFD, FD_CLOEXEC);
+#endif
+		xmove_fd(gzipDataPipe.rd, 0);
+		xmove_fd(tar_fd, 1);
+		/* exec gzip/bzip2 program/applet */
+		BB_EXECLP(zip_exec, zip_exec, "-f", NULL);
+		vfork_exec_errno = errno;
+		_exit(EXIT_FAILURE);
+	}
+
+	/* parent */
+	xmove_fd(gzipDataPipe.wr, tar_fd);
+	close(gzipDataPipe.rd);
+#if WAIT_FOR_CHILD
+	close(gzipStatusPipe.wr);
+	while (1) {
+		char buf;
+		int n;
+
+		/* Wait until child execs (or fails to) */
+		n = full_read(gzipStatusPipe.rd, &buf, 1);
+		if (n < 0 /* && errno == EAGAIN */)
+			continue;	/* try it again */
+	}
+	close(gzipStatusPipe.rd);
+#endif
+	if (vfork_exec_errno) {
+		errno = vfork_exec_errno;
+		bb_perror_msg_and_die("cannot exec %s", zip_exec);
+	}
+}
+#endif /* ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2 */
+
+
+/* gcc 4.2.1 inlines it, making code bigger */
+static NOINLINE int writeTarFile(int tar_fd, int verboseFlag,
+	int dereferenceFlag, const llist_t *include,
+	const llist_t *exclude, int gzip)
 {
-	pid_t gzipPid = 0;
 	int errorFlag = FALSE;
 	struct TarBallInfo tbInfo;
 
 	tbInfo.hlInfoHead = NULL;
-
-	fchmod(tar_fd, 0644);
 	tbInfo.tarFd = tar_fd;
 	tbInfo.verboseFlag = verboseFlag;
 
@@ -439,78 +600,26 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
 	if (fstat(tbInfo.tarFd, &tbInfo.statBuf) < 0)
 		bb_perror_msg_and_die("cannot stat tar file");
 
-	if ((ENABLE_FEATURE_TAR_GZIP || ENABLE_FEATURE_TAR_BZIP2) && gzip) {
-		int gzipDataPipe[2] = { -1, -1 };
-		int gzipStatusPipe[2] = { -1, -1 };
-		volatile int vfork_exec_errno = 0;
-		char *zip_exec = (gzip == 1) ? "gzip" : "bzip2";
-
-
-		if (pipe(gzipDataPipe) < 0 || pipe(gzipStatusPipe) < 0)
-			bb_perror_msg_and_die("pipe");
-
-		signal(SIGPIPE, SIG_IGN);	/* we only want EPIPE on errors */
-
-# if __GNUC__
-		/* Avoid vfork clobbering */
-		(void) &include;
-		(void) &errorFlag;
-		(void) &zip_exec;
-# endif
-
-		gzipPid = vfork();
-
-		if (gzipPid == 0) {
-			dup2(gzipDataPipe[0], 0);
-			close(gzipDataPipe[1]);
-
-			if (tbInfo.tarFd != 1)
-				dup2(tbInfo.tarFd, 1);
-
-			close(gzipStatusPipe[0]);
-			fcntl(gzipStatusPipe[1], F_SETFD, FD_CLOEXEC);	/* close on exec shows success */
-
-			execlp(zip_exec, zip_exec, "-f", NULL);
-			vfork_exec_errno = errno;
-
-			close(gzipStatusPipe[1]);
-			exit(-1);
-		} else if (gzipPid > 0) {
-			close(gzipDataPipe[0]);
-			close(gzipStatusPipe[1]);
-
-			while (1) {
-				char buf;
-
-				int n = full_read(gzipStatusPipe[0], &buf, 1);
-
-				if (n == 0 && vfork_exec_errno != 0) {
-					errno = vfork_exec_errno;
-					bb_perror_msg_and_die("cannot exec %s", zip_exec);
-				} else if ((n < 0) && (errno == EAGAIN || errno == EINTR))
-					continue;	/* try it again */
-				break;
-			}
-			close(gzipStatusPipe[0]);
-
-			tbInfo.tarFd = gzipDataPipe[1];
-		} else bb_perror_msg_and_die("vfork gzip");
-	}
+#if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
+	if (gzip)
+		vfork_compressor(tbInfo.tarFd, gzip);
+#endif
 
 	tbInfo.excludeList = exclude;
 
 	/* Read the directory/files and iterate over them one at a time */
 	while (include) {
-		if (!recursive_action(include->data, TRUE, dereferenceFlag,
-				FALSE, writeFileToTarball, writeFileToTarball, &tbInfo, 0))
+		if (!recursive_action(include->data, ACTION_RECURSE |
+				(dereferenceFlag ? ACTION_FOLLOWLINKS : 0),
+				writeFileToTarball, writeFileToTarball, &tbInfo, 0))
 		{
 			errorFlag = TRUE;
 		}
 		include = include->link;
 	}
 	/* Write two empty blocks to the end of the archive */
-	bzero(bb_common_bufsiz1, 2*TAR_BLOCK_SIZE);
-	xwrite(tbInfo.tarFd, bb_common_bufsiz1, 2*TAR_BLOCK_SIZE);
+	memset(block_buf, 0, 2*TAR_BLOCK_SIZE);
+	xwrite(tbInfo.tarFd, block_buf, 2*TAR_BLOCK_SIZE);
 
 	/* To be pedantically correct, we would check if the tarball
 	 * is smaller than 20 tar blocks, and pad it if it was smaller,
@@ -527,35 +636,38 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
 	if (errorFlag)
 		bb_error_msg("error exit delayed from previous errors");
 
-	if (gzipPid && waitpid(gzipPid, NULL, 0) == -1)
-		bb_error_msg("waitpid failed");
-
-	return !errorFlag;
+#if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
+	if (gzip) {
+		int status;
+		if (safe_waitpid(-1, &status, 0) == -1)
+			bb_perror_msg("waitpid");
+		else if (!WIFEXITED(status) || WEXITSTATUS(status))
+			/* gzip was killed or has exited with nonzero! */
+			errorFlag = TRUE;
+	}
+#endif
+	return errorFlag;
 }
 #else
-int writeTarFile(const int tar_fd, const int verboseFlag,
-	const unsigned long dereferenceFlag, const llist_t *include,
-	const llist_t *exclude, const int gzip);
-#endif	/* tar_create */
+int writeTarFile(int tar_fd, int verboseFlag,
+	int dereferenceFlag, const llist_t *include,
+	const llist_t *exclude, int gzip);
+#endif /* FEATURE_TAR_CREATE */
 
-#ifdef CONFIG_FEATURE_TAR_FROM
+#if ENABLE_FEATURE_TAR_FROM
 static llist_t *append_file_list_to_list(llist_t *list)
 {
 	FILE *src_stream;
-	llist_t *cur = list;
-	llist_t *tmp;
 	char *line;
 	llist_t *newlist = NULL;
 
-	while (cur) {
-		src_stream = xfopen(cur->data, "r");
-		tmp = cur;
-		cur = cur->link;
-		free(tmp);
-		while ((line = xmalloc_getline(src_stream)) != NULL) {
-			char *filename_ptr = last_char_is(line, '/');
-			if (filename_ptr > line)
-				*filename_ptr = '\0';
+	while (list) {
+		src_stream = xfopen_for_read(llist_pop(&list));
+		while ((line = xmalloc_fgetline(src_stream)) != NULL) {
+			/* kill trailing '/' unless the string is just "/" */
+			char *cp = last_char_is(line, '/');
+			if (cp > line)
+				*cp = '\0';
 			llist_add_to(&newlist, line);
 		}
 		fclose(src_stream);
@@ -563,11 +675,11 @@ static llist_t *append_file_list_to_list(llist_t *list)
 	return newlist;
 }
 #else
-#define append_file_list_to_list(x)	0
+#define append_file_list_to_list(x) 0
 #endif
 
-#ifdef CONFIG_FEATURE_TAR_COMPRESS
-static char get_header_tar_Z(archive_handle_t *archive_handle)
+#if ENABLE_FEATURE_SEAMLESS_Z
+static char FAST_FUNC get_header_tar_Z(archive_handle_t *archive_handle)
 {
 	/* Can't lseek over pipes */
 	archive_handle->seek = seek_by_read;
@@ -579,237 +691,229 @@ static char get_header_tar_Z(archive_handle_t *archive_handle)
 		bb_error_msg_and_die("invalid magic");
 	}
 
-	archive_handle->src_fd = open_transformer(archive_handle->src_fd, uncompress);
+	open_transformer(archive_handle->src_fd, unpack_Z_stream, "uncompress");
 	archive_handle->offset = 0;
 	while (get_header_tar(archive_handle) == EXIT_SUCCESS)
-		/* nothing */;
+		continue;
 
 	/* Can only do one file at a time */
 	return EXIT_FAILURE;
 }
 #else
-#define get_header_tar_Z	0
+#define get_header_tar_Z NULL
 #endif
 
-#define CTX_TEST                          (1 << 0)
-#define CTX_EXTRACT                       (1 << 1)
-#define TAR_OPT_BASEDIR                   (1 << 2)
-#define TAR_OPT_TARNAME                   (1 << 3)
-#define TAR_OPT_2STDOUT                   (1 << 4)
-#define TAR_OPT_P                         (1 << 5)
-#define TAR_OPT_VERBOSE                   (1 << 6)
-#define TAR_OPT_KEEP_OLD                  (1 << 7)
-
-#define TAR_OPT_AFTER_START               8
-
-#define CTX_CREATE                        (1 << (TAR_OPT_AFTER_START))
-#define TAR_OPT_DEREFERENCE               (1 << (TAR_OPT_AFTER_START + 1))
-#ifdef CONFIG_FEATURE_TAR_CREATE
-# define TAR_OPT_STR_CREATE               "ch"
-# define TAR_OPT_AFTER_CREATE             TAR_OPT_AFTER_START + 2
-#else
-# define TAR_OPT_STR_CREATE               ""
-# define TAR_OPT_AFTER_CREATE             TAR_OPT_AFTER_START
-#endif
+#ifdef CHECK_FOR_CHILD_EXITCODE
+/* Looks like it isn't needed - tar detects malformed (truncated)
+ * archive if e.g. bunzip2 fails */
+static int child_error;
 
-#define TAR_OPT_BZIP2                     (1 << (TAR_OPT_AFTER_CREATE))
-#ifdef CONFIG_FEATURE_TAR_BZIP2
-# define TAR_OPT_STR_BZIP2                "j"
-# define TAR_OPT_AFTER_BZIP2              TAR_OPT_AFTER_CREATE + 1
-#else
-# define TAR_OPT_STR_BZIP2                ""
-# define TAR_OPT_AFTER_BZIP2              TAR_OPT_AFTER_CREATE
-#endif
-
-#define TAR_OPT_LZMA                      (1 << (TAR_OPT_AFTER_BZIP2))
-#ifdef CONFIG_FEATURE_TAR_LZMA
-# define TAR_OPT_STR_LZMA                 "a"
-# define TAR_OPT_AFTER_LZMA               TAR_OPT_AFTER_BZIP2 + 1
-#else
-# define TAR_OPT_STR_LZMA                 ""
-# define TAR_OPT_AFTER_LZMA               TAR_OPT_AFTER_BZIP2
-#endif
-
-#define TAR_OPT_INCLUDE_FROM              (1 << (TAR_OPT_AFTER_LZMA))
-#define TAR_OPT_EXCLUDE_FROM              (1 << (TAR_OPT_AFTER_LZMA + 1))
-#ifdef CONFIG_FEATURE_TAR_FROM
-# define TAR_OPT_STR_FROM                 "T:X:"
-# define TAR_OPT_AFTER_FROM               TAR_OPT_AFTER_LZMA + 2
-#else
-# define TAR_OPT_STR_FROM                 ""
-# define TAR_OPT_AFTER_FROM               TAR_OPT_AFTER_LZMA
-#endif
-
-#define TAR_OPT_GZIP                      (1 << (TAR_OPT_AFTER_FROM))
-#ifdef CONFIG_FEATURE_TAR_GZIP
-# define TAR_OPT_STR_GZIP                 "z"
-# define TAR_OPT_AFTER_GZIP               TAR_OPT_AFTER_FROM + 1
-#else
-# define TAR_OPT_STR_GZIP                 ""
-# define TAR_OPT_AFTER_GZIP               TAR_OPT_AFTER_FROM
-#endif
-
-#define TAR_OPT_UNCOMPRESS                (1 << (TAR_OPT_AFTER_GZIP))
-#ifdef CONFIG_FEATURE_TAR_COMPRESS
-# define TAR_OPT_STR_COMPRESS             "Z"
-# define TAR_OPT_AFTER_COMPRESS           TAR_OPT_AFTER_GZIP + 1
-#else
-# define TAR_OPT_STR_COMPRESS             ""
-# define TAR_OPT_AFTER_COMPRESS           TAR_OPT_AFTER_GZIP
+static void handle_SIGCHLD(int status)
+{
+	/* Actually, 'status' is a signo. We reuse it for other needs */
+
+	/* Wait for any child without blocking */
+	if (wait_any_nohang(&status) < 0)
+		/* wait failed?! I'm confused... */
+		return;
+
+	if (WIFEXITED(status) && WEXITSTATUS(status)==0)
+		/* child exited with 0 */
+		return;
+	/* Cannot happen?
+	if (!WIFSIGNALED(status) && !WIFEXITED(status)) return; */
+	child_error = 1;
+}
 #endif
 
-#define TAR_OPT_NOPRESERVE_OWN            (1 << (TAR_OPT_AFTER_COMPRESS))
-#define TAR_OPT_NOPRESERVE_PERM           (1 << (TAR_OPT_AFTER_COMPRESS + 1))
-#define TAR_OPT_STR_NOPRESERVE            "\203\213"
-#define TAR_OPT_AFTER_NOPRESERVE          TAR_OPT_AFTER_COMPRESS + 2
-
-static const char tar_options[] = "txC:f:Opvk" \
-	TAR_OPT_STR_CREATE \
-	TAR_OPT_STR_BZIP2 \
-	TAR_OPT_STR_LZMA \
-	TAR_OPT_STR_FROM \
-	TAR_OPT_STR_GZIP \
-	TAR_OPT_STR_COMPRESS \
-	TAR_OPT_STR_NOPRESERVE;
-
-#ifdef CONFIG_FEATURE_TAR_LONG_OPTIONS
-static const struct option tar_long_options[] = {
-	{ "list",               0,  NULL,   't' },
-	{ "extract",            0,  NULL,   'x' },
-	{ "directory",          1,  NULL,   'C' },
-	{ "file",               1,  NULL,   'f' },
-	{ "to-stdout",          0,  NULL,   'O' },
-	{ "same-permissions",   0,  NULL,   'p' },
-	{ "verbose",            0,  NULL,   'v' },
-	{ "keep-old",           0,  NULL,   'k' },
-	{ "no-same-owner",      0,  NULL,   '\203' },
-	{ "no-same-permissions",0,  NULL,   '\213' },
-# ifdef CONFIG_FEATURE_TAR_CREATE
-	{ "create",             0,  NULL,   'c' },
-	{ "dereference",        0,  NULL,   'h' },
+enum {
+	OPTBIT_KEEP_OLD = 7,
+	USE_FEATURE_TAR_CREATE(   OPTBIT_CREATE      ,)
+	USE_FEATURE_TAR_CREATE(   OPTBIT_DEREFERENCE ,)
+	USE_FEATURE_SEAMLESS_BZ2( OPTBIT_BZIP2       ,)
+	USE_FEATURE_SEAMLESS_LZMA(OPTBIT_LZMA        ,)
+	USE_FEATURE_TAR_FROM(     OPTBIT_INCLUDE_FROM,)
+	USE_FEATURE_TAR_FROM(     OPTBIT_EXCLUDE_FROM,)
+	USE_FEATURE_SEAMLESS_GZ(  OPTBIT_GZIP        ,)
+	USE_FEATURE_SEAMLESS_Z(   OPTBIT_COMPRESS    ,)
+	OPTBIT_NOPRESERVE_OWN,
+	OPTBIT_NOPRESERVE_PERM,
+	OPTBIT_NUMERIC_OWNER,
+	OPT_TEST         = 1 << 0, // t
+	OPT_EXTRACT      = 1 << 1, // x
+	OPT_BASEDIR      = 1 << 2, // C
+	OPT_TARNAME      = 1 << 3, // f
+	OPT_2STDOUT      = 1 << 4, // O
+	OPT_P            = 1 << 5, // p
+	OPT_VERBOSE      = 1 << 6, // v
+	OPT_KEEP_OLD     = 1 << 7, // k
+	OPT_CREATE       = USE_FEATURE_TAR_CREATE(   (1 << OPTBIT_CREATE      )) + 0, // c
+	OPT_DEREFERENCE  = USE_FEATURE_TAR_CREATE(   (1 << OPTBIT_DEREFERENCE )) + 0, // h
+	OPT_BZIP2        = USE_FEATURE_SEAMLESS_BZ2( (1 << OPTBIT_BZIP2       )) + 0, // j
+	OPT_LZMA         = USE_FEATURE_SEAMLESS_LZMA((1 << OPTBIT_LZMA        )) + 0, // a
+	OPT_INCLUDE_FROM = USE_FEATURE_TAR_FROM(     (1 << OPTBIT_INCLUDE_FROM)) + 0, // T
+	OPT_EXCLUDE_FROM = USE_FEATURE_TAR_FROM(     (1 << OPTBIT_EXCLUDE_FROM)) + 0, // X
+	OPT_GZIP         = USE_FEATURE_SEAMLESS_GZ(  (1 << OPTBIT_GZIP        )) + 0, // z
+	OPT_COMPRESS     = USE_FEATURE_SEAMLESS_Z(   (1 << OPTBIT_COMPRESS    )) + 0, // Z
+	OPT_NOPRESERVE_OWN  = 1 << OPTBIT_NOPRESERVE_OWN , // no-same-owner
+	OPT_NOPRESERVE_PERM = 1 << OPTBIT_NOPRESERVE_PERM, // no-same-permissions
+	OPT_NUMERIC_OWNER = 1 << OPTBIT_NUMERIC_OWNER,
+};
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS
+static const char tar_longopts[] ALIGN1 =
+	"list\0"                No_argument       "t"
+	"extract\0"             No_argument       "x"
+	"directory\0"           Required_argument "C"
+	"file\0"                Required_argument "f"
+	"to-stdout\0"           No_argument       "O"
+	"same-permissions\0"    No_argument       "p"
+	"verbose\0"             No_argument       "v"
+	"keep-old\0"            No_argument       "k"
+# if ENABLE_FEATURE_TAR_CREATE
+	"create\0"              No_argument       "c"
+	"dereference\0"         No_argument       "h"
 # endif
-# ifdef CONFIG_FEATURE_TAR_BZIP2
-	{ "bzip2",              0,  NULL,   'j' },
+# if ENABLE_FEATURE_SEAMLESS_BZ2
+	"bzip2\0"               No_argument       "j"
 # endif
-# ifdef CONFIG_FEATURE_TAR_LZMA
-	{ "lzma",               0,  NULL,   'a' },
+# if ENABLE_FEATURE_SEAMLESS_LZMA
+	"lzma\0"                No_argument       "a"
 # endif
-# ifdef CONFIG_FEATURE_TAR_FROM
-	{ "files-from",         1,  NULL,   'T' },
-	{ "exclude-from",       1,  NULL,   'X' },
-	{ "exclude",            1,  NULL,   '\n' },
+# if ENABLE_FEATURE_TAR_FROM
+	"files-from\0"          Required_argument "T"
+	"exclude-from\0"        Required_argument "X"
 # endif
-# ifdef CONFIG_FEATURE_TAR_GZIP
-	{ "gzip",               0,  NULL,   'z' },
+# if ENABLE_FEATURE_SEAMLESS_GZ
+	"gzip\0"                No_argument       "z"
 # endif
-# ifdef CONFIG_FEATURE_TAR_COMPRESS
-	{ "compress",           0,  NULL,   'Z' },
+# if ENABLE_FEATURE_SEAMLESS_Z
+	"compress\0"            No_argument       "Z"
 # endif
-	{ 0,                    0, 0, 0 }
-};
-#else
-#define tar_long_options	0
+	"numeric-owner\0"       No_argument       "\xfc"
+	"no-same-owner\0"       No_argument       "\xfd"
+	"no-same-permissions\0" No_argument       "\xfe"
+	/* --exclude takes next bit position in option mask, */
+	/* therefore we have to either put it _after_ --no-same-perm */
+	/* or add OPT[BIT]_EXCLUDE before OPT[BIT]_NOPRESERVE_OWN */
+# if ENABLE_FEATURE_TAR_FROM
+	"exclude\0"             Required_argument "\xff"
+# endif
+	;
 #endif
 
-int tar_main(int argc, char **argv)
+int tar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int tar_main(int argc UNUSED_PARAM, char **argv)
 {
-	char (*get_header_ptr)(archive_handle_t *) = get_header_tar;
+	char FAST_FUNC (*get_header_ptr)(archive_handle_t *) = get_header_tar;
 	archive_handle_t *tar_handle;
 	char *base_dir = NULL;
 	const char *tar_filename = "-";
 	unsigned opt;
+	int verboseFlag = 0;
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
 	llist_t *excludes = NULL;
+#endif
 
 	/* Initialise default values */
 	tar_handle = init_handle();
-	tar_handle->flags = ARCHIVE_CREATE_LEADING_DIRS | ARCHIVE_PRESERVE_DATE | ARCHIVE_EXTRACT_UNCONDITIONAL;
+	tar_handle->ah_flags = ARCHIVE_CREATE_LEADING_DIRS
+	                     | ARCHIVE_PRESERVE_DATE
+	                     | ARCHIVE_EXTRACT_UNCONDITIONAL;
+
+	/* Apparently only root's tar preserves perms (see bug 3844) */
+	if (getuid() != 0)
+		tar_handle->ah_flags |= ARCHIVE_NOPRESERVE_PERM;
 
 	/* Prepend '-' to the first argument if required */
-	opt_complementary = ENABLE_FEATURE_TAR_CREATE ?
-		"--:X::T::\n::c:t:x:?:c--tx:t--cx:x--ct" :
-		"--:X::T::\n::t:x:?:t--x:x--t";
-	if (ENABLE_FEATURE_TAR_LONG_OPTIONS)
-		applet_long_options = tar_long_options;
-	opt = getopt32(argc, argv, tar_options,
-				&base_dir,      /* Change to dir <optarg> */
-				&tar_filename /* archive filename */
-#ifdef CONFIG_FEATURE_TAR_FROM
-				, &(tar_handle->accept),
-				&(tar_handle->reject),
-				&excludes
+	opt_complementary = "--:" // first arg is options
+		"tt:vv:" // count -t,-v
+		"?:" // bail out with usage instead of error return
+		"X::T::" // cumulative lists
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
+		"\xff::" // cumulative lists for --exclude
 #endif
-				);
+		USE_FEATURE_TAR_CREATE("c:") "t:x:" // at least one of these is reqd
+		USE_FEATURE_TAR_CREATE("c--tx:t--cx:x--ct") // mutually exclusive
+		SKIP_FEATURE_TAR_CREATE("t--x:x--t"); // mutually exclusive
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS
+	applet_long_options = tar_longopts;
+#endif
+	opt = getopt32(argv,
+		"txC:f:Opvk"
+		USE_FEATURE_TAR_CREATE(   "ch"  )
+		USE_FEATURE_SEAMLESS_BZ2( "j"   )
+		USE_FEATURE_SEAMLESS_LZMA("a"   )
+		USE_FEATURE_TAR_FROM(     "T:X:")
+		USE_FEATURE_SEAMLESS_GZ(  "z"   )
+		USE_FEATURE_SEAMLESS_Z(   "Z"   )
+		, &base_dir // -C dir
+		, &tar_filename // -f filename
+		USE_FEATURE_TAR_FROM(, &(tar_handle->accept)) // T
+		USE_FEATURE_TAR_FROM(, &(tar_handle->reject)) // X
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS && ENABLE_FEATURE_TAR_FROM
+		, &excludes // --exclude
+#endif
+		, &verboseFlag // combined count for -t and -v
+		, &verboseFlag // combined count for -t and -v
+		);
+	argv += optind;
 
-	if (opt & CTX_TEST) {
-		if (tar_handle->action_header == header_list
-		 || tar_handle->action_header == header_verbose_list
-		) {
-			tar_handle->action_header = header_verbose_list;
-		} else
-			tar_handle->action_header = header_list;
-	}
-	if ((opt & CTX_EXTRACT) && tar_handle->action_data != data_extract_to_stdout)
+	if (verboseFlag) tar_handle->action_header = header_verbose_list;
+	if (verboseFlag == 1) tar_handle->action_header = header_list;
+
+	if (opt & OPT_EXTRACT)
 		tar_handle->action_data = data_extract_all;
 
-	if (opt & TAR_OPT_2STDOUT)
+	if (opt & OPT_2STDOUT)
 		tar_handle->action_data = data_extract_to_stdout;
 
-	if (opt & TAR_OPT_VERBOSE) {
-		if (tar_handle->action_header == header_list
-		 || tar_handle->action_header == header_verbose_list
-		) {
-			tar_handle->action_header = header_verbose_list;
-		} else
-			tar_handle->action_header = header_list;
-	}
-	if (opt & TAR_OPT_KEEP_OLD)
-		tar_handle->flags &= ~ARCHIVE_EXTRACT_UNCONDITIONAL;
+	if (opt & OPT_KEEP_OLD)
+		tar_handle->ah_flags &= ~ARCHIVE_EXTRACT_UNCONDITIONAL;
+
+	if (opt & OPT_NOPRESERVE_OWN)
+		tar_handle->ah_flags |= ARCHIVE_NOPRESERVE_OWN;
 
-	if (opt & TAR_OPT_NOPRESERVE_OWN)
-		tar_handle->flags |= ARCHIVE_NOPRESERVE_OWN;
+	if (opt & OPT_NOPRESERVE_PERM)
+		tar_handle->ah_flags |= ARCHIVE_NOPRESERVE_PERM;
 
-	if (opt & TAR_OPT_NOPRESERVE_PERM)
-		tar_handle->flags |= ARCHIVE_NOPRESERVE_PERM;
+	if (opt & OPT_NUMERIC_OWNER)
+		tar_handle->ah_flags |= ARCHIVE_NUMERIC_OWNER;
 
-	if (ENABLE_FEATURE_TAR_GZIP && (opt & TAR_OPT_GZIP))
+	if (opt & OPT_GZIP)
 		get_header_ptr = get_header_tar_gz;
 
-	if (ENABLE_FEATURE_TAR_BZIP2 && (opt & TAR_OPT_BZIP2))
+	if (opt & OPT_BZIP2)
 		get_header_ptr = get_header_tar_bz2;
 
-	if (ENABLE_FEATURE_TAR_LZMA && (opt & TAR_OPT_LZMA))
+	if (opt & OPT_LZMA)
 		get_header_ptr = get_header_tar_lzma;
 
-	if (ENABLE_FEATURE_TAR_COMPRESS && (opt & TAR_OPT_UNCOMPRESS))
+	if (opt & OPT_COMPRESS)
 		get_header_ptr = get_header_tar_Z;
 
-	if (ENABLE_FEATURE_TAR_FROM) {
-		tar_handle->reject = append_file_list_to_list(tar_handle->reject);
-		/* Append excludes to reject */
-		while (excludes) {
-			llist_t *temp = excludes->link;
-			excludes->link = tar_handle->reject;
-			tar_handle->reject = excludes;
-			excludes = temp;
-		}
-		tar_handle->accept = append_file_list_to_list(tar_handle->accept);
-	}
-
-	/* Check if we are reading from stdin */
-	if (argv[optind] && *argv[optind] == '-') {
-		/* Default is to read from stdin, so just skip to next arg */
-		optind++;
+#if ENABLE_FEATURE_TAR_FROM
+	tar_handle->reject = append_file_list_to_list(tar_handle->reject);
+#if ENABLE_FEATURE_TAR_LONG_OPTIONS
+	/* Append excludes to reject */
+	while (excludes) {
+		llist_t *next = excludes->link;
+		excludes->link = tar_handle->reject;
+		tar_handle->reject = excludes;
+		excludes = next;
 	}
+#endif
+	tar_handle->accept = append_file_list_to_list(tar_handle->accept);
+#endif
 
 	/* Setup an array of filenames to work with */
 	/* TODO: This is the same as in ar, separate function ? */
-	while (optind < argc) {
-		char *filename_ptr = last_char_is(argv[optind], '/');
-		if (filename_ptr > argv[optind])
-			*filename_ptr = '\0';
-
-		llist_add_to(&(tar_handle->accept), argv[optind]);
-		optind++;
+	while (*argv) {
+		/* kill trailing '/' unless the string is just "/" */
+		char *cp = last_char_is(*argv, '/');
+		if (cp > *argv)
+			*cp = '\0';
+		llist_add_to_end(&tar_handle->accept, *argv);
+		argv++;
 	}
 
 	if (tar_handle->accept || tar_handle->reject)
@@ -820,66 +924,71 @@ int tar_main(int argc, char **argv)
 		FILE *tar_stream;
 		int flags;
 
-		if (ENABLE_FEATURE_TAR_CREATE && (opt & CTX_CREATE)) {
+		if (opt & OPT_CREATE) {
 			/* Make sure there is at least one file to tar up.  */
 			if (tar_handle->accept == NULL)
 				bb_error_msg_and_die("empty archive");
 
 			tar_stream = stdout;
 			/* Mimicking GNU tar 1.15.1: */
-			flags = O_WRONLY|O_CREAT|O_TRUNC;
-		/* was doing unlink; open(O_WRONLY|O_CREAT|O_EXCL); why? */
+			flags = O_WRONLY | O_CREAT | O_TRUNC;
 		} else {
 			tar_stream = stdin;
 			flags = O_RDONLY;
 		}
 
-		if ((tar_filename[0] == '-') && (tar_filename[1] == '\0')) {
+		if (LONE_DASH(tar_filename)) {
 			tar_handle->src_fd = fileno(tar_stream);
 			tar_handle->seek = seek_by_read;
 		} else {
-			tar_handle->src_fd = xopen3(tar_filename, flags, 0666);
+			if (ENABLE_FEATURE_TAR_AUTODETECT && flags == O_RDONLY) {
+				get_header_ptr = get_header_tar;
+				tar_handle->src_fd = open_zipped(tar_filename);
+				if (tar_handle->src_fd < 0)
+					bb_perror_msg_and_die("can't open '%s'", tar_filename);
+			} else {
+				tar_handle->src_fd = xopen(tar_filename, flags);
+			}
 		}
 	}
 
 	if (base_dir)
 		xchdir(base_dir);
 
+#ifdef CHECK_FOR_CHILD_EXITCODE
+	/* We need to know whether child (gzip/bzip/etc) exits abnormally */
+	signal(SIGCHLD, handle_SIGCHLD);
+#endif
+
 	/* create an archive */
-	if (ENABLE_FEATURE_TAR_CREATE && (opt & CTX_CREATE)) {
-		int verboseFlag = FALSE;
+	if (opt & OPT_CREATE) {
+#if ENABLE_FEATURE_SEAMLESS_GZ || ENABLE_FEATURE_SEAMLESS_BZ2
 		int zipMode = 0;
-
-		if (ENABLE_FEATURE_TAR_GZIP && get_header_ptr == get_header_tar_gz)
+		if (ENABLE_FEATURE_SEAMLESS_GZ && (opt & OPT_GZIP))
 			zipMode = 1;
-		if (ENABLE_FEATURE_TAR_BZIP2 && get_header_ptr == get_header_tar_bz2)
+		if (ENABLE_FEATURE_SEAMLESS_BZ2 && (opt & OPT_BZIP2))
 			zipMode = 2;
+#endif
+		/* NB: writeTarFile() closes tar_handle->src_fd */
+		return writeTarFile(tar_handle->src_fd, verboseFlag, opt & OPT_DEREFERENCE,
+				tar_handle->accept,
+				tar_handle->reject, zipMode);
+	}
 
-		if (tar_handle->action_header == header_list
-		 || tar_handle->action_header == header_verbose_list
+	while (get_header_ptr(tar_handle) == EXIT_SUCCESS)
+		continue;
+
+	/* Check that every file that should have been extracted was */
+	while (tar_handle->accept) {
+		if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
+		 && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
 		) {
-			verboseFlag = TRUE;
-		}
-		writeTarFile(tar_handle->src_fd, verboseFlag, opt & TAR_OPT_DEREFERENCE,
-				tar_handle->accept,
-			tar_handle->reject, zipMode);
-	} else {
-		while (get_header_ptr(tar_handle) == EXIT_SUCCESS)
-			/* nothing */;
-
-		/* Check that every file that should have been extracted was */
-		while (tar_handle->accept) {
-			if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
-			 && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
-			) {
-				bb_error_msg_and_die("%s: not found in archive",
-					tar_handle->accept->data);
-			}
-			tar_handle->accept = tar_handle->accept->link;
+			bb_error_msg_and_die("%s: not found in archive",
+				tar_handle->accept->data);
 		}
+		tar_handle->accept = tar_handle->accept->link;
 	}
-
-	if (ENABLE_FEATURE_CLEAN_UP && tar_handle->src_fd != STDIN_FILENO)
+	if (ENABLE_FEATURE_CLEAN_UP /* && tar_handle->src_fd != STDIN_FILENO */)
 		close(tar_handle->src_fd);
 
 	return EXIT_SUCCESS;