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Diffstat (limited to 'release/src/router/busybox/archival/libunarchive/get_header_tar.c')
-rw-r--r--release/src/router/busybox/archival/libunarchive/get_header_tar.c535
1 files changed, 398 insertions, 137 deletions
diff --git a/release/src/router/busybox/archival/libunarchive/get_header_tar.c b/release/src/router/busybox/archival/libunarchive/get_header_tar.c
index 33cb75df..443052f7 100644
--- a/release/src/router/busybox/archival/libunarchive/get_header_tar.c
+++ b/release/src/router/busybox/archival/libunarchive/get_header_tar.c
@@ -1,188 +1,449 @@
-/*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+/* vi: set sw=4 ts=4: */
+/* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Library General Public License for more details.
+ * 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
*
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * References:
+ * GNU tar and star man pages,
+ * Opengroup's ustar interchange format,
+ * http://www.opengroup.org/onlinepubs/007904975/utilities/pax.html
*/
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include "unarchive.h"
#include "libbb.h"
+#include "unarchive.h"
+
+/*
+ * GNU tar uses "base-256 encoding" for very large numbers (>8 billion).
+ * 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
+ *
+ * We expect it only in size field, where negative numbers don't make sense.
+ */
+static off_t getBase256_len12(const char *str)
+{
+ off_t value;
+ int len;
+
+ /* if (*str & 0x40) error; - caller prevents this */
-#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
-static char *longname = NULL;
-static char *linkname = NULL;
+ if (sizeof(off_t) >= 12) {
+ /* Probably 128-bit (16 byte) off_t. Can be optimized. */
+ len = 12;
+ value = *str++ & 0x3f;
+ while (--len)
+ value = (value << 8) + (unsigned char) *str++;
+ return value;
+ }
+
+#ifdef CHECK_FOR_OVERFLOW
+ /* Can be optimized to eat 32-bit chunks */
+ char c = *str++ & 0x3f;
+ len = 12;
+ while (1) {
+ if (c)
+ bb_error_msg_and_die("overflow in base-256 encoded file size");
+ if (--len == sizeof(off_t))
+ break;
+ c = *str++;
+ }
+#else
+ str += (12 - sizeof(off_t));
#endif
-extern char get_header_tar(archive_handle_t *archive_handle)
+/* Now str points to sizeof(off_t) least significant bytes.
+ *
+ * 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|
+ *
+ * str is at offset 80 or 84 now (64-bit or 32-bit off_t).
+ * We (ab)use the fact that value happens to be aligned,
+ * and fetch it in one go:
+ */
+ if (sizeof(off_t) == 8) {
+ value = *(off_t*)str;
+ value = SWAP_BE64(value);
+ } else if (sizeof(off_t) == 4) {
+ value = *(off_t*)str;
+ value = SWAP_BE32(value);
+ } else {
+ value = 0;
+ len = sizeof(off_t);
+ while (--len)
+ value = (value << 8) + (unsigned char) *str++;
+ }
+ return value;
+}
+
+/* NB: _DESTROYS_ str[len] character! */
+static unsigned long long getOctal(char *str, int len)
+{
+ unsigned long long v;
+ /* 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, &str, 8);
+ if (*str && (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY || *str != ' '))
+ bb_error_msg_and_die("corrupted octal value in tar header");
+ return v;
+}
+#define GET_OCTAL(a) getOctal((a), sizeof(a))
+
+void BUG_tar_header_size(void);
+char FAST_FUNC get_header_tar(archive_handle_t *archive_handle)
{
file_header_t *file_header = archive_handle->file_header;
- union {
- unsigned char raw[512];
- struct {
- char name[100]; /* 0-99 */
- 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 */
- char chksum[8]; /* 148-155 */
- char typeflag; /* 156-156 */
- char linkname[100]; /* 157-256 */
- char magic[6]; /* 257-262 */
- char version[2]; /* 263-264 */
- 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 */
- } formated;
+ struct {
+ /* ustar header, Posix 1003.1 */
+ char name[100]; /* 0-99 */
+ 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 */
+ char chksum[8]; /* 148-155 */
+ char typeflag; /* 156-156 */
+ char linkname[100]; /* 157-256 */
+ /* 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 simplify 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 */
} tar;
- long sum = 0;
- long i;
- char *tmp;
+ char *cp;
+ int i, sum_u, sum;
+#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY
+ int sum_s;
+#endif
+ int parse_names;
+
+ /* Our "private data" */
+#define p_end (*(smallint *)(&archive_handle->ah_priv[0]))
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+#define p_longname (*(char* *)(&archive_handle->ah_priv[1]))
+#define p_linkname (*(char* *)(&archive_handle->ah_priv[2]))
+#else
+#define p_longname 0
+#define p_linkname 0
+#endif
+// if (!archive_handle->ah_priv_inited) {
+// archive_handle->ah_priv_inited = 1;
+// p_end = 0;
+// USE_FEATURE_TAR_GNU_EXTENSIONS(p_longname = NULL;)
+// USE_FEATURE_TAR_GNU_EXTENSIONS(p_linkname = NULL;)
+// }
+
+ if (sizeof(tar) != 512)
+ BUG_tar_header_size();
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+ again:
+#endif
/* Align header */
data_align(archive_handle, 512);
- if (archive_xread(archive_handle, tar.raw, 512) != 512) {
- /* Assume end of file */
- return(EXIT_FAILURE);
+ again_after_align:
+
+#if ENABLE_DESKTOP || ENABLE_FEATURE_TAR_AUTODETECT
+ /* to prevent misdetection of bz2 sig */
+ *(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");
}
- archive_handle->offset += 512;
+ if (i != 512) {
+ USE_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.formated.name[0] == 0) {
- return(EXIT_SUCCESS);
+ if (tar.name[0] == 0 && tar.prefix[0] == 0) {
+ if (p_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;
+ }
+ p_end = 1;
+ return EXIT_SUCCESS;
}
+ p_end = 0;
- /* Check header has valid magic, "ustar" is for the proper tar
- * 0's are for the old tar format
- */
- if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
-#ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
- if (strncmp(tar.formated.magic, "\0\0\0\0\0", 5) != 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 *);
+
+ autodetect:
+ /* 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 (tar.name[0] == 0x1f && tar.name[1] == (char)0x8b) { /* gzip */
+ get_header_ptr = get_header_tar_gz;
+ } else
#endif
- bb_error_msg_and_die("Invalid tar magic");
+#if ENABLE_FEATURE_SEAMLESS_BZ2
+ if (tar.name[0] == 'B' && tar.name[1] == 'Z'
+ && tar.name[2] == 'h' && isdigit(tar.name[3])
+ ) { /* bzip2 */
+ get_header_ptr = get_header_tar_bz2;
+ } 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 */
- for (i = 0; i < 148 ; i++) {
- sum += tar.raw[i];
+
+ /* 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
}
- sum += ' ' * 8;
- for (i = 156; i < 512 ; i++) {
- sum += tar.raw[i];
+ 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
}
- if (sum != strtol(tar.formated.chksum, NULL, 8)) {
- bb_error_msg("Invalid tar header checksum");
- return(EXIT_FAILURE);
+#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
+ sum = strtoul(tar.chksum, &cp, 8);
+ if ((*cp && *cp != ' ')
+ || (sum_u != sum USE_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum))
+ ) {
+ bb_error_msg_and_die("invalid tar header checksum");
}
+#else
+ /* This field does not need special treatment (getOctal) */
+ sum = xstrtoul(tar.chksum, 8);
+ if (sum_u != sum USE_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum)) {
+ bb_error_msg_and_die("invalid tar header checksum");
+ }
+#endif
-#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
- if (longname) {
- file_header->name = longname;
- longname = NULL;
+ /* 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? */
}
- else if (linkname) {
- file_header->name = linkname;
- linkname = NULL;
- } else
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+ file_header->uname = tar.uname[0] ? xstrndup(tar.uname, sizeof(tar.uname)) : NULL;
+ file_header->gname = tar.gname[0] ? xstrndup(tar.gname, sizeof(tar.gname)) : NULL;
#endif
- if (tar.formated.prefix[0] == 0) {
- file_header->name = strdup(tar.formated.name);
- } else {
- file_header->name = concat_path_file(tar.formated.prefix, tar.formated.name);
- }
- tmp = last_char_is(archive_handle->file_header->name, '/');
- if (tmp) {
- *tmp = '\0';
- }
-
- file_header->mode = strtol(tar.formated.mode, NULL, 8);
- file_header->uid = strtol(tar.formated.uid, NULL, 8);
- file_header->gid = strtol(tar.formated.gid, NULL, 8);
- file_header->size = strtol(tar.formated.size, NULL, 8);
- file_header->mtime = strtol(tar.formated.mtime, NULL, 8);
- file_header->link_name = (tar.formated.linkname[0] != '\0') ?
- bb_xstrdup(tar.formated.linkname) : NULL;
- file_header->device = (dev_t) ((strtol(tar.formated.devmajor, NULL, 8) << 8) +
- strtol(tar.formated.devminor, NULL, 8));
-
-#if defined CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY || defined CONFIG_FEATURE_TAR_GNU_EXTENSIONS
- /* Fix mode, used by the old format */
- switch (tar.formated.typeflag) {
-# ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
- case 0:
+ file_header->mtime = GET_OCTAL(tar.mtime);
+ /* Size field: handle GNU tar's "base256 encoding" */
+ file_header->size = (*tar.size & 0xc0) == 0x80 /* positive base256? */
+ ? getBase256_len12(tar.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 '1':
- bb_error_msg("WARNING: Converting hard link to symlink");
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;
- break;
+ goto size0; /* paranoia */
case '4':
file_header->mode |= S_IFBLK;
- break;
+ goto size0;
case '5':
+ USE_FEATURE_TAR_OLDGNU_COMPATIBILITY(set_dir:)
file_header->mode |= S_IFDIR;
- break;
+ goto size0;
case '6':
file_header->mode |= S_IFIFO;
- break;
-# endif
-# ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
- case 'L': {
- longname = xmalloc(file_header->size + 1);
- archive_xread_all(archive_handle, longname, file_header->size);
- longname[file_header->size] = '\0';
- archive_handle->offset += file_header->size;
-
- return(get_header_tar(archive_handle));
- }
- case 'K': {
- linkname = xmalloc(file_header->size + 1);
- archive_xread_all(archive_handle, linkname, file_header->size);
- linkname[file_header->size] = '\0';
- archive_handle->offset += file_header->size;
-
- file_header->name = linkname;
- return(get_header_tar(archive_handle));
- }
- case 'D':
- case 'M':
- case 'N':
- case 'S':
- case 'V':
- bb_error_msg("Ignoring GNU extension type %c", tar.formated.typeflag);
-# endif
+ 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
+ case 'g': /* pax global header */
+ case 'x': { /* pax extended header */
+ 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;
+ }
+ 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);
- archive_handle->flags |= ARCHIVE_EXTRACT_QUIET;
+ 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->ah_flags |= ARCHIVE_EXTRACT_QUIET;
archive_handle->action_data(archive_handle);
- archive_handle->passed = llist_add_to(archive_handle->passed, archive_handle->file_header->name);
+ llist_add_to(&(archive_handle->passed), file_header->name);
} else {
- data_skip(archive_handle);
+ data_skip(archive_handle);
+ free(file_header->name);
}
archive_handle->offset += file_header->size;
- return(EXIT_SUCCESS);
+ free(file_header->link_target);
+ /* Do not free(file_header->name)! (why?) */
+#if ENABLE_FEATURE_TAR_UNAME_GNAME
+ free(file_header->uname);
+ free(file_header->gname);
+#endif
+ return EXIT_SUCCESS;
}
-
generated by cgit v1.2.3-54-g00ecf (git 2.44.0) at 2024-04-19 22:50:26 +0000