*/
#include "libbb.h"
-#include "archive.h"
+#include "bb_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)
{
*
* 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);
+ /* Sign-extend 7bit 'first' to 64bit 'v' (that is, using 6th bit as sign): */
+ first <<= 1;
+ first >>= 1; /* now 7th bit = 6th bit */
+ v = first; /* sign-extend 8 bits to 64 */
while (--len != 0)
- v = (v << 8) + (unsigned char) *str++;
+ v = (v << 8) + (uint8_t) *++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)
+/* "global" is 0 or 1 */
+static void process_pax_hdr(archive_handle_t *archive_handle, unsigned sz, int global)
{
char *buf, *p;
- char *result;
+ unsigned blk_sz;
+
+ blk_sz = (sz + 511) & (~511);
+ p = buf = xmalloc(blk_sz + 1);
+ xread(archive_handle->src_fd, buf, blk_sz);
+ archive_handle->offset += blk_sz;
- 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;
*/
p += len;
sz -= len;
- if ((int)sz < 0
+ if (
+ /** (int)sz < 0 - not good enough for huge malicious VALUE of 2^32-1 */
+ (int)(sz|len) < 0 /* this works */
|| len == 0
|| errno != EINVAL
|| *end != ' '
* (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) {
+
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+ if (!global && is_prefixed_with(value, "path=")) {
+ value += sizeof("path=") - 1;
+ free(archive_handle->tar__longname);
+ archive_handle->tar__longname = xstrdup(value);
+ continue;
+ }
+#endif
+
+#if ENABLE_FEATURE_TAR_SELINUX
+ /* Scan 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"
+ if (is_prefixed_with(value, SELINUX_CONTEXT_KEYWORD"=")) {
value += sizeof(SELINUX_CONTEXT_KEYWORD"=") - 1;
- result = xstrdup(value);
- break;
+ free(archive_handle->tar__sctx[global]);
+ archive_handle->tar__sctx[global] = xstrdup(value);
+ continue;
}
+#endif
}
free(buf);
- return result;
}
-#endif
char FAST_FUNC get_header_tar(archive_handle_t *archive_handle)
{
* 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");
+ bb_error_msg("short read");
+ /* this merely signals end of archive, not exit(1): */
+ return EXIT_FAILURE;
}
if (i != 512) {
IF_FEATURE_TAR_AUTODETECT(goto autodetect;)
- goto short_read;
+ bb_error_msg_and_die("short read");
}
#else
*/
while (full_read(archive_handle->src_fd, &tar, 512) == 512)
continue;
- return EXIT_FAILURE;
+ return EXIT_FAILURE; /* "end of archive" */
}
archive_handle->tar__end = 1;
- return EXIT_SUCCESS;
+ return EXIT_SUCCESS; /* "decoded one header" */
}
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
+ if (!is_prefixed_with(tar.magic, "ustar")
&& (!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 = *(bb__aliased_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;
+ if (setup_unzip_on_fd(archive_handle->src_fd, /*fail_if_not_compressed:*/ 0) != 0)
err:
-#endif /* FEATURE_TAR_AUTODETECT */
+ bb_error_msg_and_die("invalid tar magic");
+ archive_handle->offset = 0;
+ goto again_after_align;
+#endif
bb_error_msg_and_die("invalid tar magic");
}
/* 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':
+ case '1': /* hardlink */
+ /* we mark hardlinks as regular files with zero size and a link name */
file_header->mode |= S_IFREG;
- break;
+ /* on size of link fields from star(4)
+ * ... For tar archives written by pre POSIX.1-1988
+ * implementations, the size field usually contains the size of
+ * the file and needs to be ignored as no data may follow this
+ * header type. For POSIX.1- 1988 compliant archives, the size
+ * field needs to be 0. For POSIX.1-2001 compliant archives,
+ * the size field may be non zero, indicating that file data is
+ * included in the archive.
+ * i.e; always assume this is zero for safety.
+ */
+ goto size0;
case '7':
/* case 0: */
case '0':
case '6':
file_header->mode |= S_IFIFO;
goto size0;
+ case 'g': /* pax global header */
+ case 'x': { /* pax extended header */
+ if ((uoff_t)file_header->size > 0xfffff) /* paranoia */
+ goto skip_ext_hdr;
+ process_pax_hdr(archive_handle, file_header->size, (tar.typeflag == 'g'));
+ goto again_after_align;
#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+/* See http://www.gnu.org/software/tar/manual/html_node/Extensions.html */
case 'L':
/* free: paranoia: tar with several consecutive longnames */
free(p_longname);
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 */
+/*
+ * case 'S': // Sparse file
+ * Was seen in the wild. Not supported (yet?).
+ * See https://www.gnu.org/software/tar/manual/html_section/tar_92.html
+ * for the format. (An "Old GNU Format" was seen, not PAX formats).
+ */
+// case 'D': /* GNU dump dir */
+// case 'M': /* Continuation of multi volume archive */
+// case 'N': /* Old GNU for names > 100 characters */
+// 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);
/* 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);
}
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);
- }
+
+ /* Everything up to and including last ".." component is stripped */
+ overlapping_strcpy(file_header->name, strip_unsafe_prefix(file_header->name));
/* Strip trailing '/' in directories */
/* Must be done after mode is set as '/' is used to check if it's a directory */
if (cp)
*cp = '\0';
archive_handle->action_data(archive_handle);
- if (archive_handle->accept || archive_handle->reject)
+ if (archive_handle->accept || archive_handle->reject
+ || (archive_handle->ah_flags & ARCHIVE_REMEMBER_NAMES)
+ ) {
llist_add_to(&archive_handle->passed, file_header->name);
- else /* Caller isn't interested in list of unpacked files */
+ } else /* Caller isn't interested in list of unpacked files */
free(file_header->name);
} else {
data_skip(archive_handle);
free(file_header->tar__uname);
free(file_header->tar__gname);
#endif
- return EXIT_SUCCESS;
+ return EXIT_SUCCESS; /* "decoded one header" */
}
projects / oweals / busybox.git / blobdiff