rename archival/libunarchive -> archival/libarchive; move bz/ into it

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 461 insertions, 0 deletions

diff --git a/archival/libarchive/get_header_tar.c b/archival/libarchive/get_header_tar.c
new file mode 100644
index 0000000..78b0ae2
--- /dev/null
+++ b/archival/libarchive/get_header_tar.c
@@ -0,0 +1,461 @@
+/* vi: set sw=4 ts=4: */
+/* Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ *
+ * FIXME:
+ *    In privileged mode if uname and gname map to a uid and gid then use the
+ *    mapped value instead of the uid/gid values in tar header
+ *
+ * References:
+ *    GNU tar and star man pages,
+ *    Opengroup's ustar interchange format,
+ *    http://www.opengroup.org/onlinepubs/007904975/utilities/pax.html
+ */
+
+#include "libbb.h"
+#include "archive.h"
+
+typedef uint32_t aliased_uint32_t FIX_ALIASING;
+typedef off_t    aliased_off_t    FIX_ALIASING;
+
+
+/* NB: _DESTROYS_ str[len] character! */
+static unsigned long long getOctal(char *str, int len)
+{
+	unsigned long long v;
+	char *end;
+	/* NB: leading spaces are allowed. Using strtoull to handle that.
+	 * The downside is that we accept e.g. "-123" too :(
+	 */
+	str[len] = '\0';
+	v = strtoull(str, &end, 8);
+	/* std: "Each numeric field is terminated by one or more
+	 * <space> or NUL characters". We must support ' '! */
+	if (*end != '\0' && *end != ' ') {
+		int8_t first = str[0];
+		if (!(first & 0x80))
+			bb_error_msg_and_die("corrupted octal value in tar header");
+		/*
+		 * GNU tar uses "base-256 encoding" for very large numbers.
+		 * Encoding is binary, with highest bit always set as a marker
+		 * and sign in next-highest bit:
+		 * 80 00 .. 00 - zero
+		 * bf ff .. ff - largest positive number
+		 * ff ff .. ff - minus 1
+		 * c0 00 .. 00 - smallest negative number
+		 *
+		 * Example of tar file with 8914993153 (0x213600001) byte file.
+		 * Field starts at offset 7c:
+		 * 00070  30 30 30 00 30 30 30 30  30 30 30 00 80 00 00 00  |000.0000000.....|
+		 * 00080  00 00 00 02 13 60 00 01  31 31 31 32 30 33 33 36  |.....`..11120336|
+		 *
+		 * NB: tarballs with NEGATIVE unix times encoded that way were seen!
+		 */
+		v = first;
+		/* Sign-extend using 6th bit: */
+		v <<= sizeof(unsigned long long)*8 - 7;
+		v = (long long)v >> (sizeof(unsigned long long)*8 - 7);
+		while (--len != 0)
+			v = (v << 8) + (unsigned char) *str++;
+	}
+	return v;
+}
+#define GET_OCTAL(a) getOctal((a), sizeof(a))
+
+#if ENABLE_FEATURE_TAR_SELINUX
+/* Scan a PAX header for SELinux contexts, via "RHT.security.selinux" keyword.
+ * This is what Red Hat's patched version of tar uses.
+ */
+# define SELINUX_CONTEXT_KEYWORD "RHT.security.selinux"
+static char *get_selinux_sctx_from_pax_hdr(archive_handle_t *archive_handle, unsigned sz)
+{
+	char *buf, *p;
+	char *result;
+
+	p = buf = xmalloc(sz + 1);
+	/* prevent bb_strtou from running off the buffer */
+	buf[sz] = '\0';
+	xread(archive_handle->src_fd, buf, sz);
+	archive_handle->offset += sz;
+
+	result = NULL;
+	while (sz != 0) {
+		char *end, *value;
+		unsigned len;
+
+		/* Every record has this format: "LEN NAME=VALUE\n" */
+		len = bb_strtou(p, &end, 10);
+		/* expect errno to be EINVAL, because the character
+		 * following the digits should be a space
+		 */
+		p += len;
+		sz -= len;
+		if ((int)sz < 0
+		 || len == 0
+		 || errno != EINVAL
+		 || *end != ' '
+		) {
+			bb_error_msg("malformed extended header, skipped");
+			// More verbose version:
+			//bb_error_msg("malformed extended header at %"OFF_FMT"d, skipped",
+			//		archive_handle->offset - (sz + len));
+			break;
+		}
+		/* overwrite the terminating newline with NUL
+		 * (we do not bother to check that it *was* a newline)
+		 */
+		p[-1] = '\0';
+		/* Is it selinux security context? */
+		value = end + 1;
+		if (strncmp(value, SELINUX_CONTEXT_KEYWORD"=", sizeof(SELINUX_CONTEXT_KEYWORD"=") - 1) == 0) {
+			value += sizeof(SELINUX_CONTEXT_KEYWORD"=") - 1;
+			result = xstrdup(value);
+			break;
+		}
+	}
+
+	free(buf);
+	return result;
+}
+#endif
+
+char FAST_FUNC get_header_tar(archive_handle_t *archive_handle)
+{
+	file_header_t *file_header = archive_handle->file_header;
+	struct tar_header_t tar;
+	char *cp;
+	int i, sum_u, sum;
+#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY
+	int sum_s;
+#endif
+	int parse_names;
+
+	/* Our "private data" */
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+# define p_longname (archive_handle->tar__longname)
+# define p_linkname (archive_handle->tar__linkname)
+#else
+# define p_longname 0
+# define p_linkname 0
+#endif
+
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS || ENABLE_FEATURE_TAR_SELINUX
+ again:
+#endif
+	/* Align header */
+	data_align(archive_handle, 512);
+
+ again_after_align:
+
+#if ENABLE_DESKTOP || ENABLE_FEATURE_TAR_AUTODETECT
+	/* to prevent misdetection of bz2 sig */
+	*(aliased_uint32_t*)&tar = 0;
+	i = full_read(archive_handle->src_fd, &tar, 512);
+	/* If GNU tar sees EOF in above read, it says:
+	 * "tar: A lone zero block at N", where N = kilobyte
+	 * where EOF was met (not EOF block, actual EOF!),
+	 * and exits with EXIT_SUCCESS.
+	 * We will mimic exit(EXIT_SUCCESS), although we will not mimic
+	 * the message and we don't check whether we indeed
+	 * saw zero block directly before this. */
+	if (i == 0) {
+		xfunc_error_retval = 0;
+ short_read:
+		bb_error_msg_and_die("short read");
+	}
+	if (i != 512) {
+		IF_FEATURE_TAR_AUTODETECT(goto autodetect;)
+		goto short_read;
+	}
+
+#else
+	i = 512;
+	xread(archive_handle->src_fd, &tar, i);
+#endif
+	archive_handle->offset += i;
+
+	/* If there is no filename its an empty header */
+	if (tar.name[0] == 0 && tar.prefix[0] == 0) {
+		if (archive_handle->tar__end) {
+			/* Second consecutive empty header - end of archive.
+			 * Read until the end to empty the pipe from gz or bz2
+			 */
+			while (full_read(archive_handle->src_fd, &tar, 512) == 512)
+				continue;
+			return EXIT_FAILURE;
+		}
+		archive_handle->tar__end = 1;
+		return EXIT_SUCCESS;
+	}
+	archive_handle->tar__end = 0;
+
+	/* Check header has valid magic, "ustar" is for the proper tar,
+	 * five NULs are for the old tar format  */
+	if (strncmp(tar.magic, "ustar", 5) != 0
+	 && (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
+	     || memcmp(tar.magic, "\0\0\0\0", 5) != 0)
+	) {
+#if ENABLE_FEATURE_TAR_AUTODETECT
+		char FAST_FUNC (*get_header_ptr)(archive_handle_t *);
+		uint16_t magic2;
+
+ autodetect:
+		magic2 = *(uint16_t*)tar.name;
+		/* tar gz/bz autodetect: check for gz/bz2 magic.
+		 * If we see the magic, and it is the very first block,
+		 * we can switch to get_header_tar_gz/bz2/lzma().
+		 * Needs seekable fd. I wish recv(MSG_PEEK) works
+		 * on any fd... */
+# if ENABLE_FEATURE_SEAMLESS_GZ
+		if (magic2 == GZIP_MAGIC) {
+			get_header_ptr = get_header_tar_gz;
+		} else
+# endif
+# if ENABLE_FEATURE_SEAMLESS_BZ2
+		if (magic2 == BZIP2_MAGIC
+		 && tar.name[2] == 'h' && isdigit(tar.name[3])
+		) { /* bzip2 */
+			get_header_ptr = get_header_tar_bz2;
+		} else
+# endif
+# if ENABLE_FEATURE_SEAMLESS_XZ
+		//TODO: if (magic2 == XZ_MAGIC1)...
+		//else
+# endif
+			goto err;
+		/* Two different causes for lseek() != 0:
+		 * unseekable fd (would like to support that too, but...),
+		 * or not first block (false positive, it's not .gz/.bz2!) */
+		if (lseek(archive_handle->src_fd, -i, SEEK_CUR) != 0)
+			goto err;
+		while (get_header_ptr(archive_handle) == EXIT_SUCCESS)
+			continue;
+		return EXIT_FAILURE;
+ err:
+#endif /* FEATURE_TAR_AUTODETECT */
+		bb_error_msg_and_die("invalid tar magic");
+	}
+
+	/* Do checksum on headers.
+	 * POSIX says that checksum is done on unsigned bytes, but
+	 * Sun and HP-UX gets it wrong... more details in
+	 * GNU tar source. */
+#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY
+	sum_s = ' ' * sizeof(tar.chksum);
+#endif
+	sum_u = ' ' * sizeof(tar.chksum);
+	for (i = 0; i < 148; i++) {
+		sum_u += ((unsigned char*)&tar)[i];
+#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY
+		sum_s += ((signed char*)&tar)[i];
+#endif
+	}
+	for (i = 156; i < 512; i++) {
+		sum_u += ((unsigned char*)&tar)[i];
+#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY
+		sum_s += ((signed char*)&tar)[i];
+#endif
+	}
+	/* This field does not need special treatment (getOctal) */
+	{
+		char *endp; /* gcc likes temp var for &endp */
+		sum = strtoul(tar.chksum, &endp, 8);
+		if ((*endp != '\0' && *endp != ' ')
+		 || (sum_u != sum IF_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum))
+		) {
+			bb_error_msg_and_die("invalid tar header checksum");
+		}
+	}
+	/* don't use xstrtoul, tar.chksum may have leading spaces */
+	sum = strtoul(tar.chksum, NULL, 8);
+	if (sum_u != sum IF_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum)) {
+		bb_error_msg_and_die("invalid tar header checksum");
+	}
+
+	/* 0 is reserved for high perf file, treat as normal file */
+	if (!tar.typeflag) tar.typeflag = '0';
+	parse_names = (tar.typeflag >= '0' && tar.typeflag <= '7');
+
+	/* getOctal trashes subsequent field, therefore we call it
+	 * on fields in reverse order */
+	if (tar.devmajor[0]) {
+		char t = tar.prefix[0];
+		/* we trash prefix[0] here, but we DO need it later! */
+		unsigned minor = GET_OCTAL(tar.devminor);
+		unsigned major = GET_OCTAL(tar.devmajor);
+		file_header->device = makedev(major, minor);
+		tar.prefix[0] = t;
+	}
+	file_header->link_target = NULL;
+	if (!p_linkname && parse_names && tar.linkname[0]) {
+		file_header->link_target = xstrndup(tar.linkname, sizeof(tar.linkname));
+		/* FIXME: what if we have non-link object with link_target? */
+		/* Will link_target be free()ed? */
+	}
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+	file_header->tar__uname = tar.uname[0] ? xstrndup(tar.uname, sizeof(tar.uname)) : NULL;
+	file_header->tar__gname = tar.gname[0] ? xstrndup(tar.gname, sizeof(tar.gname)) : NULL;
+#endif
+	file_header->mtime = GET_OCTAL(tar.mtime);
+	file_header->size = GET_OCTAL(tar.size);
+	file_header->gid = GET_OCTAL(tar.gid);
+	file_header->uid = GET_OCTAL(tar.uid);
+	/* Set bits 0-11 of the files mode */
+	file_header->mode = 07777 & GET_OCTAL(tar.mode);
+
+	file_header->name = NULL;
+	if (!p_longname && parse_names) {
+		/* we trash mode[0] here, it's ok */
+		//tar.name[sizeof(tar.name)] = '\0'; - gcc 4.3.0 would complain
+		tar.mode[0] = '\0';
+		if (tar.prefix[0]) {
+			/* and padding[0] */
+			//tar.prefix[sizeof(tar.prefix)] = '\0'; - gcc 4.3.0 would complain
+			tar.padding[0] = '\0';
+			file_header->name = concat_path_file(tar.prefix, tar.name);
+		} else
+			file_header->name = xstrdup(tar.name);
+	}
+
+	/* Set bits 12-15 of the files mode */
+	/* (typeflag was not trashed because chksum does not use getOctal) */
+	switch (tar.typeflag) {
+	/* busybox identifies hard links as being regular files with 0 size and a link name */
+	case '1':
+		file_header->mode |= S_IFREG;
+		break;
+	case '7':
+	/* case 0: */
+	case '0':
+#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
+		if (last_char_is(file_header->name, '/')) {
+			goto set_dir;
+		}
+#endif
+		file_header->mode |= S_IFREG;
+		break;
+	case '2':
+		file_header->mode |= S_IFLNK;
+		/* have seen tarballs with size field containing
+		 * the size of the link target's name */
+ size0:
+		file_header->size = 0;
+		break;
+	case '3':
+		file_header->mode |= S_IFCHR;
+		goto size0; /* paranoia */
+	case '4':
+		file_header->mode |= S_IFBLK;
+		goto size0;
+	case '5':
+ IF_FEATURE_TAR_OLDGNU_COMPATIBILITY(set_dir:)
+		file_header->mode |= S_IFDIR;
+		goto size0;
+	case '6':
+		file_header->mode |= S_IFIFO;
+		goto size0;
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+	case 'L':
+		/* free: paranoia: tar with several consecutive longnames */
+		free(p_longname);
+		/* For paranoia reasons we allocate extra NUL char */
+		p_longname = xzalloc(file_header->size + 1);
+		/* We read ASCIZ string, including NUL */
+		xread(archive_handle->src_fd, p_longname, file_header->size);
+		archive_handle->offset += file_header->size;
+		/* return get_header_tar(archive_handle); */
+		/* gcc 4.1.1 didn't optimize it into jump */
+		/* so we will do it ourself, this also saves stack */
+		goto again;
+	case 'K':
+		free(p_linkname);
+		p_linkname = xzalloc(file_header->size + 1);
+		xread(archive_handle->src_fd, p_linkname, file_header->size);
+		archive_handle->offset += file_header->size;
+		/* return get_header_tar(archive_handle); */
+		goto again;
+	case 'D':	/* GNU dump dir */
+	case 'M':	/* Continuation of multi volume archive */
+	case 'N':	/* Old GNU for names > 100 characters */
+	case 'S':	/* Sparse file */
+	case 'V':	/* Volume header */
+#endif
+#if !ENABLE_FEATURE_TAR_SELINUX
+	case 'g':	/* pax global header */
+	case 'x':	/* pax extended header */
+#else
+ skip_ext_hdr:
+#endif
+	{
+		off_t sz;
+		bb_error_msg("warning: skipping header '%c'", tar.typeflag);
+		sz = (file_header->size + 511) & ~(off_t)511;
+		archive_handle->offset += sz;
+		sz >>= 9; /* sz /= 512 but w/o contortions for signed div */
+		while (sz--)
+			xread(archive_handle->src_fd, &tar, 512);
+		/* return get_header_tar(archive_handle); */
+		goto again_after_align;
+	}
+#if ENABLE_FEATURE_TAR_SELINUX
+	case 'g':	/* pax global header */
+	case 'x': {	/* pax extended header */
+		char **pp;
+		if ((uoff_t)file_header->size > 0xfffff) /* paranoia */
+			goto skip_ext_hdr;
+		pp = (tar.typeflag == 'g') ? &archive_handle->tar__global_sctx : &archive_handle->tar__next_file_sctx;
+		free(*pp);
+		*pp = get_selinux_sctx_from_pax_hdr(archive_handle, file_header->size);
+		goto again;
+	}
+#endif
+	default:
+		bb_error_msg_and_die("unknown typeflag: 0x%x", tar.typeflag);
+	}
+
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+	if (p_longname) {
+		file_header->name = p_longname;
+		p_longname = NULL;
+	}
+	if (p_linkname) {
+		file_header->link_target = p_linkname;
+		p_linkname = NULL;
+	}
+#endif
+	if (strncmp(file_header->name, "/../"+1, 3) == 0
+	 || strstr(file_header->name, "/../")
+	) {
+		bb_error_msg_and_die("name with '..' encountered: '%s'",
+				file_header->name);
+	}
+
+	/* Strip trailing '/' in directories */
+	/* Must be done after mode is set as '/' is used to check if it's a directory */
+	cp = last_char_is(file_header->name, '/');
+
+	if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
+		archive_handle->action_header(/*archive_handle->*/ file_header);
+		/* Note that we kill the '/' only after action_header() */
+		/* (like GNU tar 1.15.1: verbose mode outputs "dir/dir/") */
+		if (cp)
+			*cp = '\0';
+		archive_handle->action_data(archive_handle);
+		if (archive_handle->accept || archive_handle->reject)
+			llist_add_to(&archive_handle->passed, file_header->name);
+		else /* Caller isn't interested in list of unpacked files */
+			free(file_header->name);
+	} else {
+		data_skip(archive_handle);
+		free(file_header->name);
+	}
+	archive_handle->offset += file_header->size;
+
+	free(file_header->link_target);
+	/* Do not free(file_header->name)!
+	 * It might be inserted in archive_handle->passed - see above */
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+	free(file_header->tar__uname);
+	free(file_header->tar__gname);
+#endif
+	return EXIT_SUCCESS;
+}