1 /* vi: set sw=4 ts=4: */
2 /* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
5 * In privileged mode if uname and gname map to a uid and gid then use the
6 * mapped value instead of the uid/gid values in tar header
9 * GNU tar and star man pages,
10 * Opengroup's ustar interchange format,
11 * http://www.opengroup.org/onlinepubs/007904975/utilities/pax.html
15 #include "unarchive.h"
17 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
18 static char *longname;
19 static char *linkname;
27 /* NB: _DESTROYS_ str[len] character! */
28 static unsigned long long getOctal(char *str, int len)
31 /* Actually, tar header allows leading spaces also.
32 * Oh well, we will be liberal and skip this...
33 * The only downside probably is that we allow "-123" too :)
34 if (*str < '0' || *str > '7')
35 bb_error_msg_and_die("corrupted octal value in tar header");
38 v = strtoull(str, &str, 8);
40 bb_error_msg_and_die("corrupted octal value in tar header");
43 #define GET_OCTAL(a) getOctal((a), sizeof(a))
45 void BUG_tar_header_size(void);
46 char get_header_tar(archive_handle_t *archive_handle)
50 file_header_t *file_header = archive_handle->file_header;
52 /* ustar header, Posix 1003.1 */
53 char name[100]; /* 0-99 */
54 char mode[8]; /* 100-107 */
55 char uid[8]; /* 108-115 */
56 char gid[8]; /* 116-123 */
57 char size[12]; /* 124-135 */
58 char mtime[12]; /* 136-147 */
59 char chksum[8]; /* 148-155 */
60 char typeflag; /* 156-156 */
61 char linkname[100]; /* 157-256 */
62 char magic[6]; /* 257-262 */
63 char version[2]; /* 263-264 */
64 char uname[32]; /* 265-296 */
65 char gname[32]; /* 297-328 */
66 char devmajor[8]; /* 329-336 */
67 char devminor[8]; /* 337-344 */
68 char prefix[155]; /* 345-499 */
69 char padding[12]; /* 500-512 */
72 int i, sum_u, sum_s, sum;
75 if (sizeof(tar) != 512)
76 BUG_tar_header_size();
78 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
82 data_align(archive_handle, 512);
86 xread(archive_handle->src_fd, &tar, 512);
87 archive_handle->offset += 512;
89 /* If there is no filename its an empty header */
90 if (tar.name[0] == 0) {
92 /* This is the second consecutive empty header! End of archive!
93 * Read until the end to empty the pipe from gz or bz2
95 while (full_read(archive_handle->src_fd, &tar, 512) == 512)
104 /* Check header has valid magic, "ustar" is for the proper tar
105 * 0's are for the old tar format
107 if (strncmp(tar.magic, "ustar", 5) != 0) {
108 #if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
109 if (memcmp(tar.magic, "\0\0\0\0", 5) != 0)
111 bb_error_msg_and_die("invalid tar magic");
114 /* Do checksum on headers.
115 * POSIX says that checksum is done on unsigned bytes, but
116 * Sun and HP-UX gets it wrong... more details in
118 sum_s = sum_u = ' ' * sizeof(tar.chksum);
119 for (i = 0; i < 148 ; i++) {
120 sum_u += ((unsigned char*)&tar)[i];
121 sum_s += ((signed char*)&tar)[i];
123 for (i = 156; i < 512 ; i++) {
124 sum_u += ((unsigned char*)&tar)[i];
125 sum_s += ((signed char*)&tar)[i];
127 /* This field does not need special treatment (getOctal) */
128 sum = xstrtoul(tar.chksum, 8);
129 if (sum_u != sum && sum_s != sum) {
130 bb_error_msg_and_die("invalid tar header checksum");
133 /* 0 is reserved for high perf file, treat as normal file */
134 if (!tar.typeflag) tar.typeflag = '0';
135 parse_names = (tar.typeflag >= '0' && tar.typeflag <= '7');
137 /* getOctal trashes subsequent field, therefore we call it
138 * on fields in reverse order */
139 if (tar.devmajor[0]) {
140 unsigned minor = GET_OCTAL(tar.devminor);
141 unsigned major = GET_OCTAL(tar.devmajor);
142 file_header->device = makedev(major, minor);
144 file_header->link_name = NULL;
145 if (!linkname && parse_names && tar.linkname[0]) {
146 /* we trash magic[0] here, it's ok */
147 tar.linkname[sizeof(tar.linkname)] = '\0';
148 file_header->link_name = xstrdup(tar.linkname);
149 /* FIXME: what if we have non-link object with link_name? */
150 /* Will link_name be free()ed? */
152 file_header->mtime = GET_OCTAL(tar.mtime);
153 file_header->size = GET_OCTAL(tar.size);
154 file_header->gid = GET_OCTAL(tar.gid);
155 file_header->uid = GET_OCTAL(tar.uid);
156 /* Set bits 0-11 of the files mode */
157 file_header->mode = 07777 & GET_OCTAL(tar.mode);
159 file_header->name = NULL;
160 if (!longname && parse_names) {
161 /* we trash mode[0] here, it's ok */
162 tar.name[sizeof(tar.name)] = '\0';
165 tar.prefix[sizeof(tar.prefix)] = '\0';
166 file_header->name = concat_path_file(tar.prefix, tar.name);
168 file_header->name = xstrdup(tar.name);
171 /* Set bits 12-15 of the files mode */
172 /* (typeflag was not trashed because chksum does not use getOctal) */
173 switch (tar.typeflag) {
174 /* busybox identifies hard links as being regular files with 0 size and a link name */
176 file_header->mode |= S_IFREG;
181 #if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
182 if (last_char_is(file_header->name, '/')) {
183 file_header->mode |= S_IFDIR;
186 file_header->mode |= S_IFREG;
189 file_header->mode |= S_IFLNK;
192 file_header->mode |= S_IFCHR;
195 file_header->mode |= S_IFBLK;
198 file_header->mode |= S_IFDIR;
201 file_header->mode |= S_IFIFO;
203 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
205 /* free: paranoia: tar with several consecutive longnames */
207 /* For paranoia reasons we allocate extra NUL char */
208 longname = xzalloc(file_header->size + 1);
209 /* We read ASCIZ string, including NUL */
210 xread(archive_handle->src_fd, longname, file_header->size);
211 archive_handle->offset += file_header->size;
212 /* return get_header_tar(archive_handle); */
213 /* gcc 4.1.1 didn't optimize it into jump */
214 /* so we will do it ourself, this also saves stack */
218 linkname = xzalloc(file_header->size + 1);
219 xread(archive_handle->src_fd, linkname, file_header->size);
220 archive_handle->offset += file_header->size;
221 /* return get_header_tar(archive_handle); */
223 case 'D': /* GNU dump dir */
224 case 'M': /* Continuation of multi volume archive */
225 case 'N': /* Old GNU for names > 100 characters */
226 case 'S': /* Sparse file */
227 case 'V': /* Volume header */
229 case 'g': /* pax global header */
230 case 'x': { /* pax extended header */
232 bb_error_msg("warning: skipping header '%c'", tar.typeflag);
233 sz = (file_header->size + 511) & ~(off_t)511;
234 archive_handle->offset += sz;
235 sz >>= 9; /* sz /= 512 but w/o contortions for signed div */
237 xread(archive_handle->src_fd, &tar, 512);
238 /* return get_header_tar(archive_handle); */
239 goto again_after_align;
242 bb_error_msg_and_die("unknown typeflag: 0x%x", tar.typeflag);
245 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
247 file_header->name = longname;
251 file_header->link_name = linkname;
255 if (!strncmp(file_header->name, "/../"+1, 3)
256 || strstr(file_header->name, "/../")
258 bb_error_msg_and_die("name with '..' encountered: '%s'",
262 /* Strip trailing '/' in directories */
263 /* Must be done after mode is set as '/' is used to check if it's a directory */
264 cp = last_char_is(file_header->name, '/');
266 if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
267 archive_handle->action_header(archive_handle->file_header);
268 /* Note that we kill the '/' only after action_header() */
269 /* (like GNU tar 1.15.1: verbose mode outputs "dir/dir/") */
271 archive_handle->flags |= ARCHIVE_EXTRACT_QUIET;
272 archive_handle->action_data(archive_handle);
273 llist_add_to(&(archive_handle->passed), file_header->name);
275 data_skip(archive_handle);
276 free(file_header->name);
278 archive_handle->offset += file_header->size;
280 free(file_header->link_name);
281 /* Do not free(file_header->name)! */