1 /* $OpenBSD: pax.c,v 1.47 2016/08/26 04:11:16 guenther Exp $ */ 2 /* $NetBSD: pax.c,v 1.5 1996/03/26 23:54:20 mrg Exp $ */ 3 4 /*- 5 * Copyright (c) 1992 Keith Muller. 6 * Copyright (c) 1992, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * Keith Muller of the University of California, San Diego. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #include <sys/types.h> 38 #include <sys/stat.h> 39 #include <sys/resource.h> 40 #include <signal.h> 41 #include <unistd.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <errno.h> 45 #include <err.h> 46 #include <fcntl.h> 47 #include <paths.h> 48 #include <stdio.h> 49 50 #include "pax.h" 51 #include "extern.h" 52 static int gen_init(void); 53 54 /* 55 * PAX main routines, general globals and some simple start up routines 56 */ 57 58 /* 59 * Variables that can be accessed by any routine within pax 60 */ 61 int act = DEFOP; /* read/write/append/copy */ 62 FSUB *frmt = NULL; /* archive format type */ 63 int cflag; /* match all EXCEPT pattern/file */ 64 int cwdfd; /* starting cwd */ 65 int dflag; /* directory member match only */ 66 int iflag; /* interactive file/archive rename */ 67 int kflag; /* do not overwrite existing files */ 68 int lflag; /* use hard links when possible */ 69 int nflag; /* select first archive member match */ 70 int tflag; /* restore access time after read */ 71 int uflag; /* ignore older modification time files */ 72 int vflag; /* produce verbose output */ 73 int Dflag; /* same as uflag except inode change time */ 74 int Hflag; /* follow command line symlinks (write only) */ 75 int Lflag; /* follow symlinks when writing */ 76 int Nflag; /* only use numeric uid and gid */ 77 int Xflag; /* archive files with same device id only */ 78 int Yflag; /* same as Dflag except after name mode */ 79 int Zflag; /* same as uflag except after name mode */ 80 int zeroflag; /* use \0 as pathname terminator */ 81 int vfpart; /* is partial verbose output in progress */ 82 int patime = 1; /* preserve file access time */ 83 int pmtime = 1; /* preserve file modification times */ 84 int nodirs; /* do not create directories as needed */ 85 int pmode; /* preserve file mode bits */ 86 int pids; /* preserve file uid/gid */ 87 int rmleadslash = 0; /* remove leading '/' from pathnames */ 88 int exit_val; /* exit value */ 89 int docrc; /* check/create file crc */ 90 char *dirptr; /* destination dir in a copy */ 91 char *argv0; /* root of argv[0] */ 92 enum op_mode op_mode; /* what program are we acting as? */ 93 sigset_t s_mask; /* signal mask for cleanup critical sect */ 94 FILE *listf = stderr; /* file pointer to print file list to */ 95 int listfd = STDERR_FILENO; /* fd matching listf, for sighandler output */ 96 char *tempfile; /* tempfile to use for mkstemp(3) */ 97 char *tempbase; /* basename of tempfile to use for mkstemp(3) */ 98 99 /* 100 * PAX - Portable Archive Interchange 101 * 102 * A utility to read, write, and write lists of the members of archive 103 * files and copy directory hierarchies. A variety of archive formats 104 * are supported (some are described in POSIX 1003.1 10.1): 105 * 106 * ustar - 10.1.1 extended tar interchange format 107 * cpio - 10.1.2 extended cpio interchange format 108 * tar - old BSD 4.3 tar format 109 * binary cpio - old cpio with binary header format 110 * sysVR4 cpio - with and without CRC 111 * 112 * This version is a superset of IEEE Std 1003.2b-d3 113 * 114 * Summary of Extensions to the IEEE Standard: 115 * 116 * 1 READ ENHANCEMENTS 117 * 1.1 Operations which read archives will continue to operate even when 118 * processing archives which may be damaged, truncated, or fail to meet 119 * format specs in several different ways. Damaged sections of archives 120 * are detected and avoided if possible. Attempts will be made to resync 121 * archive read operations even with badly damaged media. 122 * 1.2 Blocksize requirements are not strictly enforced on archive read. 123 * Tapes which have variable sized records can be read without errors. 124 * 1.3 The user can specify via the non-standard option flag -E if error 125 * resync operation should stop on a media error, try a specified number 126 * of times to correct, or try to correct forever. 127 * 1.4 Sparse files (lseek holes) stored on the archive (but stored with blocks 128 * of all zeros will be restored with holes appropriate for the target 129 * filesystem 130 * 1.5 The user is notified whenever something is found during archive 131 * read operations which violates spec (but the read will continue). 132 * 1.6 Multiple archive volumes can be read and may span over different 133 * archive devices 134 * 1.7 Rigidly restores all file attributes exactly as they are stored on the 135 * archive. 136 * 1.8 Modification change time ranges can be specified via multiple -T 137 * options. These allow a user to select files whose modification time 138 * lies within a specific time range. 139 * 1.9 Files can be selected based on owner (user name or uid) via one or more 140 * -U options. 141 * 1.10 Files can be selected based on group (group name or gid) via one o 142 * more -G options. 143 * 1.11 File modification time can be checked against existing file after 144 * name modification (-Z) 145 * 146 * 2 WRITE ENHANCEMENTS 147 * 2.1 Write operation will stop instead of allowing a user to create a flawed 148 * flawed archive (due to any problem). 149 * 2.2 Archives written by pax are forced to strictly conform to both the 150 * archive and pax the specific format specifications. 151 * 2.3 Blocking size and format is rigidly enforced on writes. 152 * 2.4 Formats which may exhibit header overflow problems (they have fields 153 * too small for large file systems, such as inode number storage), use 154 * routines designed to repair this problem. These techniques still 155 * conform to both pax and format specifications, but no longer truncate 156 * these fields. This removes any restrictions on using these archive 157 * formats on large file systems. 158 * 2.5 Multiple archive volumes can be written and may span over different 159 * archive devices 160 * 2.6 A archive volume record limit allows the user to specify the number 161 * of bytes stored on an archive volume. When reached the user is 162 * prompted for the next archive volume. This is specified with the 163 * non-standard -B flag. The limit is rounded up to the next blocksize. 164 * 2.7 All archive padding during write use zero filled sections. This makes 165 * it much easier to pull data out of flawed archive during read 166 * operations. 167 * 2.8 Access time reset with the -t applies to all file nodes (including 168 * directories). 169 * 2.9 Symbolic links can be followed with -L (optional in the spec). 170 * 2.10 Modification or inode change time ranges can be specified via 171 * multiple -T options. These allow a user to select files whose 172 * modification or inode change time lies within a specific time range. 173 * 2.11 Files can be selected based on owner (user name or uid) via one or more 174 * -U options. 175 * 2.12 Files can be selected based on group (group name or gid) via one o 176 * more -G options. 177 * 2.13 Symlinks which appear on the command line can be followed (without 178 * following other symlinks; -H flag) 179 * 180 * 3 COPY ENHANCEMENTS 181 * 3.1 Sparse files (lseek holes) can be copied without expanding the holes 182 * into zero filled blocks. The file copy is created with holes which are 183 * appropriate for the target filesystem 184 * 3.2 Access time as well as modification time on copied file trees can be 185 * preserved with the appropriate -p options. 186 * 3.3 Access time reset with the -t applies to all file nodes (including 187 * directories). 188 * 3.4 Symbolic links can be followed with -L (optional in the spec). 189 * 3.5 Modification or inode change time ranges can be specified via 190 * multiple -T options. These allow a user to select files whose 191 * modification or inode change time lies within a specific time range. 192 * 3.6 Files can be selected based on owner (user name or uid) via one or more 193 * -U options. 194 * 3.7 Files can be selected based on group (group name or gid) via one o 195 * more -G options. 196 * 3.8 Symlinks which appear on the command line can be followed (without 197 * following other symlinks; -H flag) 198 * 3.9 File inode change time can be checked against existing file before 199 * name modification (-D) 200 * 3.10 File inode change time can be checked against existing file after 201 * name modification (-Y) 202 * 3.11 File modification time can be checked against existing file after 203 * name modification (-Z) 204 * 205 * 4 GENERAL ENHANCEMENTS 206 * 4.1 Internal structure is designed to isolate format dependent and 207 * independent functions. Formats are selected via a format driver table. 208 * This encourages the addition of new archive formats by only having to 209 * write those routines which id, read and write the archive header. 210 */ 211 212 /* 213 * main() 214 * parse options, set up and operate as specified by the user. 215 * any operational flaw will set exit_val to non-zero 216 * Return: 0 if ok, 1 otherwise 217 */ 218 219 int 220 main(int argc, char **argv) 221 { 222 char *tmpdir; 223 size_t tdlen; 224 225 /* 226 * Keep a reference to cwd, so we can always come back home. 227 */ 228 cwdfd = open(".", O_RDONLY | O_CLOEXEC); 229 if (cwdfd < 0) { 230 syswarn(1, errno, "Can't open current working directory."); 231 return(exit_val); 232 } 233 234 /* 235 * Where should we put temporary files? 236 */ 237 if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0') 238 tmpdir = _PATH_TMP; 239 tdlen = strlen(tmpdir); 240 while (tdlen > 0 && tmpdir[tdlen - 1] == '/') 241 tdlen--; 242 tempfile = malloc(tdlen + 1 + sizeof(_TFILE_BASE)); 243 if (tempfile == NULL) { 244 paxwarn(1, "Cannot allocate memory for temp file name."); 245 return(exit_val); 246 } 247 if (tdlen) 248 memcpy(tempfile, tmpdir, tdlen); 249 tempbase = tempfile + tdlen; 250 *tempbase++ = '/'; 251 252 /* 253 * parse options, determine operational mode, general init 254 */ 255 options(argc, argv); 256 if ((gen_init() < 0) || (tty_init() < 0)) 257 return(exit_val); 258 259 /* 260 * pmode needs to restore setugid bits when extracting or copying, 261 * so can't pledge at all then. 262 */ 263 if (pmode == 0 || (act != EXTRACT && act != COPY)) { 264 if (pledge("stdio rpath wpath cpath fattr dpath getpw ioctl proc exec", 265 NULL) == -1) 266 err(1, "pledge"); 267 268 /* Copy mode, or no gzip -- don't need to fork/exec. */ 269 if (gzip_program == NULL || act == COPY) { 270 if (pledge("stdio rpath wpath cpath fattr dpath getpw ioctl", 271 NULL) == -1) 272 err(1, "pledge"); 273 } 274 } 275 276 /* 277 * select a primary operation mode 278 */ 279 switch (act) { 280 case EXTRACT: 281 extract(); 282 break; 283 case ARCHIVE: 284 archive(); 285 break; 286 case APPND: 287 if (gzip_program != NULL) 288 errx(1, "can not gzip while appending"); 289 append(); 290 break; 291 case COPY: 292 copy(); 293 break; 294 default: 295 case LIST: 296 list(); 297 break; 298 } 299 return(exit_val); 300 } 301 302 /* 303 * sig_cleanup() 304 * when interrupted we try to do whatever delayed processing we can. 305 * This is not critical, but we really ought to limit our damage when we 306 * are aborted by the user. 307 * Return: 308 * never.... 309 */ 310 311 void 312 sig_cleanup(int which_sig) 313 { 314 char errbuf[80]; 315 316 /* 317 * restore modes and times for any dirs we may have created 318 * or any dirs we may have read. 319 */ 320 321 /* paxwarn() uses stdio; fake it as well as we can */ 322 if (which_sig == SIGXCPU) 323 strlcpy(errbuf, "\nCPU time limit reached, cleaning up.\n", 324 sizeof errbuf); 325 else 326 strlcpy(errbuf, "\nSignal caught, cleaning up.\n", 327 sizeof errbuf); 328 (void) write(STDERR_FILENO, errbuf, strlen(errbuf)); 329 330 ar_close(1); 331 sltab_process(1); 332 proc_dir(1); 333 if (tflag) 334 atdir_end(); 335 _exit(1); 336 } 337 338 /* 339 * setup_sig() 340 * set a signal to be caught, but only if it isn't being ignored already 341 */ 342 343 static int 344 setup_sig(int sig, const struct sigaction *n_hand) 345 { 346 struct sigaction o_hand; 347 348 if (sigaction(sig, NULL, &o_hand) < 0) 349 return (-1); 350 351 if (o_hand.sa_handler == SIG_IGN) 352 return (0); 353 354 return (sigaction(sig, n_hand, NULL)); 355 } 356 357 /* 358 * gen_init() 359 * general setup routines. Not all are required, but they really help 360 * when dealing with a medium to large sized archives. 361 */ 362 363 static int 364 gen_init(void) 365 { 366 struct rlimit reslimit; 367 struct sigaction n_hand; 368 369 /* 370 * Really needed to handle large archives. We can run out of memory for 371 * internal tables really fast when we have a whole lot of files... 372 */ 373 if (getrlimit(RLIMIT_DATA , &reslimit) == 0){ 374 reslimit.rlim_cur = reslimit.rlim_max; 375 (void)setrlimit(RLIMIT_DATA , &reslimit); 376 } 377 378 /* 379 * should file size limits be waived? if the os limits us, this is 380 * needed if we want to write a large archive 381 */ 382 if (getrlimit(RLIMIT_FSIZE , &reslimit) == 0){ 383 reslimit.rlim_cur = reslimit.rlim_max; 384 (void)setrlimit(RLIMIT_FSIZE , &reslimit); 385 } 386 387 /* 388 * increase the size the stack can grow to 389 */ 390 if (getrlimit(RLIMIT_STACK , &reslimit) == 0){ 391 reslimit.rlim_cur = reslimit.rlim_max; 392 (void)setrlimit(RLIMIT_STACK , &reslimit); 393 } 394 395 /* 396 * not really needed, but doesn't hurt 397 */ 398 if (getrlimit(RLIMIT_RSS , &reslimit) == 0){ 399 reslimit.rlim_cur = reslimit.rlim_max; 400 (void)setrlimit(RLIMIT_RSS , &reslimit); 401 } 402 403 /* 404 * signal handling to reset stored directory times and modes. Since 405 * we deal with broken pipes via failed writes we ignore it. We also 406 * deal with any file size limit through failed writes. Cpu time 407 * limits are caught and a cleanup is forced. 408 */ 409 if ((sigemptyset(&s_mask) < 0) || (sigaddset(&s_mask, SIGTERM) < 0) || 410 (sigaddset(&s_mask,SIGINT) < 0)||(sigaddset(&s_mask,SIGHUP) < 0) || 411 (sigaddset(&s_mask,SIGPIPE) < 0)||(sigaddset(&s_mask,SIGQUIT)<0) || 412 (sigaddset(&s_mask,SIGXCPU) < 0)||(sigaddset(&s_mask,SIGXFSZ)<0)) { 413 paxwarn(1, "Unable to set up signal mask"); 414 return(-1); 415 } 416 417 /* snag the fd to be used from the signal handler */ 418 listfd = fileno(listf); 419 420 memset(&n_hand, 0, sizeof n_hand); 421 n_hand.sa_mask = s_mask; 422 n_hand.sa_flags = 0; 423 n_hand.sa_handler = sig_cleanup; 424 425 if (setup_sig(SIGHUP, &n_hand) || 426 setup_sig(SIGTERM, &n_hand) || 427 setup_sig(SIGINT, &n_hand) || 428 setup_sig(SIGQUIT, &n_hand) || 429 setup_sig(SIGXCPU, &n_hand)) 430 goto out; 431 432 n_hand.sa_handler = SIG_IGN; 433 if ((sigaction(SIGPIPE, &n_hand, NULL) < 0) || 434 (sigaction(SIGXFSZ, &n_hand, NULL) < 0)) 435 goto out; 436 return(0); 437 438 out: 439 syswarn(1, errno, "Unable to set up signal handler"); 440 return(-1); 441 } 442