#include "libbb.h"
#include "unarchive.h"
-#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
-static char *longname = NULL;
-static char *linkname = NULL;
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+static char *longname;
+static char *linkname;
+#else
+enum {
+ longname = 0,
+ linkname = 0,
+};
#endif
+/* NB: _DESTROYS_ str[len] character! */
+static unsigned long long getOctal(char *str, int len)
+{
+ unsigned long long v;
+ /* Actually, tar header allows leading spaces also.
+ * Oh well, we will be liberal and skip this...
+ * The only downside probably is that we allow "-123" too :)
+ if (*str < '0' || *str > '7')
+ bb_error_msg_and_die("corrupted octal value in tar header");
+ */
+ str[len] = '\0';
+ v = strtoull(str, &str, 8);
+ if (*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 get_header_tar(archive_handle_t *archive_handle)
{
+ static int end;
+
file_header_t *file_header = archive_handle->file_header;
- union {
+ struct {
/* ustar header, Posix 1003.1 */
- 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 */
- } formatted;
+ 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 */
} tar;
- long sum = 0;
- long i;
- static int end = 0;
+ char *cp;
+ int sum, i;
+ int parse_names;
+
+ if (sizeof(tar) != 512)
+ BUG_tar_header_size();
+ again:
/* Align header */
data_align(archive_handle, 512);
- xread(archive_handle->src_fd, tar.raw, 512);
+ again_after_align:
+
+ xread(archive_handle->src_fd, &tar, 512);
archive_handle->offset += 512;
/* If there is no filename its an empty header */
- if (tar.formatted.name[0] == 0) {
+ if (tar.name[0] == 0) {
if (end) {
/* This is the 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.raw, 512) == 512);
- return(EXIT_FAILURE);
+ while (full_read(archive_handle->src_fd, &tar, 512) == 512)
+ /* repeat */;
+ return EXIT_FAILURE;
}
end = 1;
- return(EXIT_SUCCESS);
+ return EXIT_SUCCESS;
}
end = 0;
/* Check header has valid magic, "ustar" is for the proper tar
* 0's are for the old tar format
*/
- if (strncmp(tar.formatted.magic, "ustar", 5) != 0) {
-#ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATIBILITY
- if (strncmp(tar.formatted.magic, "\0\0\0\0\0", 5) != 0)
+ if (strncmp(tar.magic, "ustar", 5) != 0) {
+#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
+ if (memcmp(tar.magic, "\0\0\0\0", 5) != 0)
#endif
- bb_error_msg_and_die("Invalid tar magic");
+ bb_error_msg_and_die("invalid tar magic");
}
/* Do checksum on headers */
- for (i = 0; i < 148 ; i++) {
- sum += tar.raw[i];
+ sum = ' ' * sizeof(tar.chksum);
+ for (i = 0; i < 148 ; i++) {
+ sum += ((char*)&tar)[i];
}
- sum += ' ' * 8;
- for (i = 156; i < 512 ; i++) {
- sum += tar.raw[i];
+ for (i = 156; i < 512 ; i++) {
+ sum += ((char*)&tar)[i];
}
- if (sum != strtol(tar.formatted.chksum, NULL, 8)) {
- bb_error_msg("Invalid tar header checksum");
- return(EXIT_FAILURE);
+ /* This field does not need special treatment (getOctal) */
+ if (sum != xstrtoul(tar.chksum, 8)) {
+ bb_error_msg_and_die("invalid tar header checksum");
}
-#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
- if (longname) {
- file_header->name = longname;
- longname = NULL;
- }
- else if (linkname) {
- file_header->name = linkname;
- linkname = NULL;
- } else
-#endif
- {
- file_header->name = xstrndup(tar.formatted.name,100);
+ /* 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');
- if (tar.formatted.prefix[0]) {
- char *temp = file_header->name;
- file_header->name = concat_path_file(tar.formatted.prefix, temp);
- free(temp);
- }
+ /* getOctal trashes subsequent field, therefore we call it
+ * on fields in reverse order */
+ if (tar.devmajor[0]) {
+ unsigned minor = GET_OCTAL(tar.devminor);
+ unsigned major = GET_OCTAL(tar.devmajor);
+ file_header->device = makedev(major, minor);
}
-
- file_header->uid = strtol(tar.formatted.uid, NULL, 8);
- file_header->gid = strtol(tar.formatted.gid, NULL, 8);
- file_header->size = strtol(tar.formatted.size, NULL, 8);
- file_header->mtime = strtol(tar.formatted.mtime, NULL, 8);
- file_header->link_name = (tar.formatted.linkname[0] != '\0') ?
- xstrdup(tar.formatted.linkname) : NULL;
- file_header->device = makedev(strtol(tar.formatted.devmajor, NULL, 8),
- strtol(tar.formatted.devminor, NULL, 8));
-
+ file_header->link_name = NULL;
+ if (!linkname && parse_names && tar.linkname[0]) {
+ /* we trash magic[0] here, it's ok */
+ tar.linkname[sizeof(tar.linkname)] = '\0';
+ file_header->link_name = xstrdup(tar.linkname);
+ /* FIXME: what if we have non-link object with link_name? */
+ /* Will link_name be free()ed? */
+ }
+ 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 & strtol(tar.formatted.mode, NULL, 8);
+ file_header->mode = 07777 & GET_OCTAL(tar.mode);
+
+ file_header->name = NULL;
+ if (!longname && parse_names) {
+ /* we trash mode[0] here, it's ok */
+ tar.name[sizeof(tar.name)] = '\0';
+ if (tar.prefix[0]) {
+ /* and padding[0] */
+ tar.prefix[sizeof(tar.prefix)] = '\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 */
- switch (tar.formatted.typeflag) {
+ /* (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':
- /* Reserved for high performance files, treat as normal file */
- case 0:
+ /* case 0: */
case '0':
-#ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATIBILITY
+#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
if (last_char_is(file_header->name, '/')) {
file_header->mode |= S_IFDIR;
} else
#endif
- file_header->mode |= S_IFREG;
+ file_header->mode |= S_IFREG;
break;
case '2':
file_header->mode |= S_IFLNK;
case '6':
file_header->mode |= S_IFIFO;
break;
-#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
- case 'L': {
- longname = xzalloc(file_header->size + 1);
- xread(archive_handle->src_fd, longname, file_header->size);
- archive_handle->offset += file_header->size;
-
- return(get_header_tar(archive_handle));
- }
- case 'K': {
- linkname = xzalloc(file_header->size + 1);
- xread(archive_handle->src_fd, linkname, file_header->size);
- archive_handle->offset += file_header->size;
-
- file_header->name = linkname;
- return(get_header_tar(archive_handle));
- }
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+ case 'L':
+ /* free: paranoia: tar with several consecutive longnames */
+ free(longname);
+ /* For paranoia reasons we allocate extra NUL char */
+ longname = xzalloc(file_header->size + 1);
+ /* We read ASCIZ string, including NUL */
+ xread(archive_handle->src_fd, 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(linkname);
+ linkname = xzalloc(file_header->size + 1);
+ xread(archive_handle->src_fd, 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 '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 */
- bb_error_msg("Ignoring extension type %c", tar.formatted.typeflag);
- break;
+ 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("Unknown typeflag: 0x%x", tar.formatted.typeflag);
+ bb_error_msg_and_die("unknown typeflag: 0x%x", tar.typeflag);
}
- { /* Strip trailing '/' in directories */
- /* Must be done after mode is set as '/' is used to check if its a directory */
- char *tmp = last_char_is(file_header->name, '/');
- if (tmp) {
- *tmp = '\0';
- }
+
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+ if (longname) {
+ file_header->name = longname;
+ longname = NULL;
}
+ if (linkname) {
+ file_header->link_name = linkname;
+ linkname = NULL;
+ }
+#endif
+ if (!strncmp(file_header->name, "/../"+1, 3)
+ || 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->flags |= ARCHIVE_EXTRACT_QUIET;
archive_handle->action_data(archive_handle);
llist_add_to(&(archive_handle->passed), file_header->name);
} else {
data_skip(archive_handle);
+ free(file_header->name);
}
archive_handle->offset += file_header->size;
free(file_header->link_name);
+ /* Do not free(file_header->name)! */
- return(EXIT_SUCCESS);
+ return EXIT_SUCCESS;
}