/* $OpenBSD: pax.c,v 1.57 2023/11/26 16:04:17 espie Exp $ */ /* $NetBSD: pax.c,v 1.5 1996/03/26 23:54:20 mrg Exp $ */ /*- * Copyright (c) 1992 Keith Muller. * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Keith Muller of the University of California, San Diego. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/types.h> #include <sys/stat.h> #include <sys/resource.h> #include <signal.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <err.h> #include <fcntl.h> #include <grp.h> #include <paths.h> #include <pwd.h> #include <stdio.h> #include "pax.h" #include "extern.h" static int gen_init(void); static void sig_cleanup(int); /* * PAX main routines, general globals and some simple start up routines */ /* * Variables that can be accessed by any routine within pax */ int act = DEFOP; /* read/write/append/copy */ FSUB *frmt = NULL; /* archive format type */ int cflag; /* match all EXCEPT pattern/file */ int cwdfd; /* starting cwd */ int dflag; /* directory member match only */ int iflag; /* interactive file/archive rename */ int kflag; /* do not overwrite existing files */ int lflag; /* use hard links when possible */ int nflag; /* select first archive member match */ int tflag; /* restore access time after read */ int uflag; /* ignore older modification time files */ int vflag; /* produce verbose output */ int Dflag; /* same as uflag except inode change time */ int Hflag; /* follow command line symlinks (write only) */ int Lflag; /* follow symlinks when writing */ int Nflag; /* only use numeric uid and gid */ int Xflag; /* archive files with same device id only */ int Yflag; /* same as Dflag except after name mode */ int Zflag; /* same as uflag except after name mode */ int zeroflag; /* use \0 as pathname terminator */ int vfpart; /* is partial verbose output in progress */ int patime = 1; /* preserve file access time */ int pmtime = 1; /* preserve file modification times */ int nodirs; /* do not create directories as needed */ int pmode; /* preserve file mode bits */ int pids; /* preserve file uid/gid */ int rmleadslash = 0; /* remove leading '/' from pathnames */ int exit_val; /* exit value */ int docrc; /* check/create file crc */ char *dirptr; /* destination dir in a copy */ char *argv0; /* root of argv[0] */ enum op_mode op_mode; /* what program are we acting as? */ sigset_t s_mask; /* signal mask for cleanup critical sect */ FILE *listf; /* file pointer to print file list to */ int listfd = STDERR_FILENO; /* fd matching listf, for sighandler output */ char *tempfile; /* tempfile to use for mkstemp(3) */ char *tempbase; /* basename of tempfile to use for mkstemp(3) */ /* * PAX - Portable Archive Interchange * * A utility to read, write, and write lists of the members of archive * files and copy directory hierarchies. A variety of archive formats * are supported (some are described in POSIX 1003.1 10.1): * * ustar - 10.1.1 extended tar interchange format * cpio - 10.1.2 extended cpio interchange format * tar - old BSD 4.3 tar format * binary cpio - old cpio with binary header format * sysVR4 cpio - with and without CRC * * This version is a superset of IEEE Std 1003.2b-d3 * * Summary of Extensions to the IEEE Standard: * * 1 READ ENHANCEMENTS * 1.1 Operations which read archives will continue to operate even when * processing archives which may be damaged, truncated, or fail to meet * format specs in several different ways. Damaged sections of archives * are detected and avoided if possible. Attempts will be made to resync * archive read operations even with badly damaged media. * 1.2 Blocksize requirements are not strictly enforced on archive read. * Tapes which have variable sized records can be read without errors. * 1.3 The user can specify via the non-standard option flag -E if error * resync operation should stop on a media error, try a specified number * of times to correct, or try to correct forever. * 1.4 Sparse files (lseek holes) stored on the archive (but stored with blocks * of all zeros will be restored with holes appropriate for the target * filesystem * 1.5 The user is notified whenever something is found during archive * read operations which violates spec (but the read will continue). * 1.6 Multiple archive volumes can be read and may span over different * archive devices * 1.7 Rigidly restores all file attributes exactly as they are stored on the * archive. * 1.8 Modification change time ranges can be specified via multiple -T * options. These allow a user to select files whose modification time * lies within a specific time range. * 1.9 Files can be selected based on owner (user name or uid) via one or more * -U options. * 1.10 Files can be selected based on group (group name or gid) via one o * more -G options. * 1.11 File modification time can be checked against existing file after * name modification (-Z) * * 2 WRITE ENHANCEMENTS * 2.1 Write operation will stop instead of allowing a user to create a flawed * flawed archive (due to any problem). * 2.2 Archives written by pax are forced to strictly conform to both the * archive and pax the specific format specifications. * 2.3 Blocking size and format is rigidly enforced on writes. * 2.4 Formats which may exhibit header overflow problems (they have fields * too small for large file systems, such as inode number storage), use * routines designed to repair this problem. These techniques still * conform to both pax and format specifications, but no longer truncate * these fields. This removes any restrictions on using these archive * formats on large file systems. * 2.5 Multiple archive volumes can be written and may span over different * archive devices * 2.6 A archive volume record limit allows the user to specify the number * of bytes stored on an archive volume. When reached the user is * prompted for the next archive volume. This is specified with the * non-standard -B flag. The limit is rounded up to the next blocksize. * 2.7 All archive padding during write use zero filled sections. This makes * it much easier to pull data out of flawed archive during read * operations. * 2.8 Access time reset with the -t applies to all file nodes (including * directories). * 2.9 Symbolic links can be followed with -L (optional in the spec). * 2.10 Modification or inode change time ranges can be specified via * multiple -T options. These allow a user to select files whose * modification or inode change time lies within a specific time range. * 2.11 Files can be selected based on owner (user name or uid) via one or more * -U options. * 2.12 Files can be selected based on group (group name or gid) via one o * more -G options. * 2.13 Symlinks which appear on the command line can be followed (without * following other symlinks; -H flag) * * 3 COPY ENHANCEMENTS * 3.1 Sparse files (lseek holes) can be copied without expanding the holes * into zero filled blocks. The file copy is created with holes which are * appropriate for the target filesystem * 3.2 Access time as well as modification time on copied file trees can be * preserved with the appropriate -p options. * 3.3 Access time reset with the -t applies to all file nodes (including * directories). * 3.4 Symbolic links can be followed with -L (optional in the spec). * 3.5 Modification or inode change time ranges can be specified via * multiple -T options. These allow a user to select files whose * modification or inode change time lies within a specific time range. * 3.6 Files can be selected based on owner (user name or uid) via one or more * -U options. * 3.7 Files can be selected based on group (group name or gid) via one o * more -G options. * 3.8 Symlinks which appear on the command line can be followed (without * following other symlinks; -H flag) * 3.9 File inode change time can be checked against existing file before * name modification (-D) * 3.10 File inode change time can be checked against existing file after * name modification (-Y) * 3.11 File modification time can be checked against existing file after * name modification (-Z) * * 4 GENERAL ENHANCEMENTS * 4.1 Internal structure is designed to isolate format dependent and * independent functions. Formats are selected via a format driver table. * This encourages the addition of new archive formats by only having to * write those routines which id, read and write the archive header. */ /* * main() * parse options, set up and operate as specified by the user. * any operational flaw will set exit_val to non-zero * Return: 0 if ok, 1 otherwise */ int main(int argc, char **argv) { char *tmpdir; size_t tdlen; listf = stderr; /* * Keep a reference to cwd, so we can always come back home. */ cwdfd = open(".", O_RDONLY | O_CLOEXEC); if (cwdfd == -1) { syswarn(1, errno, "Can't open current working directory."); return(exit_val); } /* * Where should we put temporary files? */ if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0') tmpdir = _PATH_TMP; tdlen = strlen(tmpdir); while (tdlen > 0 && tmpdir[tdlen - 1] == '/') tdlen--; tempfile = malloc(tdlen + 1 + sizeof(_TFILE_BASE)); if (tempfile == NULL) { paxwarn(1, "Cannot allocate memory for temp file name."); return(exit_val); } if (tdlen) memcpy(tempfile, tmpdir, tdlen); tempbase = tempfile + tdlen; *tempbase++ = '/'; /* * keep passwd and group files open for faster lookups. */ setpassent(1); setgroupent(1); /* * parse options, determine operational mode, general init */ options(argc, argv); if ((gen_init() < 0) || (tty_init() < 0)) return(exit_val); /* * pmode needs to restore setugid bits when extracting or copying, * so can't pledge at all then. */ if (pmode == 0 || (act != EXTRACT && act != COPY)) { /* Copy mode, or no gzip -- don't need to fork/exec. */ if (gzip_program == NULL || act == COPY) { /* List mode -- don't need to write/create/modify files. */ if (act == LIST) { if (pledge("stdio rpath getpw tape", NULL) == -1) err(1, "pledge"); /* Append mode -- don't need to create/modify files. */ } else if (act == APPND) { if (pledge("stdio rpath wpath getpw tape", NULL) == -1) err(1, "pledge"); } else { if (pledge("stdio rpath wpath cpath fattr dpath getpw tape", NULL) == -1) err(1, "pledge"); } } else { if (act == LIST) { if (pledge("stdio rpath getpw proc exec tape", NULL) == -1) err(1, "pledge"); /* can not gzip while appending */ } else { if (pledge("stdio rpath wpath cpath fattr dpath getpw proc exec tape", NULL) == -1) err(1, "pledge"); } } } /* * select a primary operation mode */ switch (act) { case EXTRACT: extract(); break; case ARCHIVE: archive(); break; case APPND: if (gzip_program != NULL) errx(1, "can not gzip while appending"); append(); break; case COPY: copy(); break; default: case LIST: list(); break; } return(exit_val); } /* * sig_cleanup() * when interrupted we try to do whatever delayed processing we can. * This is not critical, but we really ought to limit our damage when we * are aborted by the user. * Return: * never.... */ static void sig_cleanup(int which_sig) { /* * restore modes and times for any dirs we may have created * or any dirs we may have read. */ /* paxwarn() uses stdio; fake it as well as we can */ if (which_sig == SIGXCPU) dprintf(STDERR_FILENO, "\nCPU time limit reached, cleaning up.\n"); else dprintf(STDERR_FILENO, "\nSignal caught, cleaning up.\n"); ar_close(1); sltab_process(1); proc_dir(1); if (tflag) atdir_end(); _exit(1); } /* * setup_sig() * set a signal to be caught, but only if it isn't being ignored already */ static int setup_sig(int sig, const struct sigaction *n_hand) { struct sigaction o_hand; if (sigaction(sig, NULL, &o_hand) == -1) return (-1); if (o_hand.sa_handler == SIG_IGN) return (0); return (sigaction(sig, n_hand, NULL)); } /* * gen_init() * general setup routines. Not all are required, but they really help * when dealing with a medium to large sized archives. */ static int gen_init(void) { struct rlimit reslimit; struct sigaction n_hand; /* * Really needed to handle large archives. We can run out of memory for * internal tables really fast when we have a whole lot of files... */ if (getrlimit(RLIMIT_DATA , &reslimit) == 0){ reslimit.rlim_cur = reslimit.rlim_max; (void)setrlimit(RLIMIT_DATA , &reslimit); } /* * should file size limits be waived? if the os limits us, this is * needed if we want to write a large archive */ if (getrlimit(RLIMIT_FSIZE , &reslimit) == 0){ reslimit.rlim_cur = reslimit.rlim_max; (void)setrlimit(RLIMIT_FSIZE , &reslimit); } /* * increase the size the stack can grow to */ if (getrlimit(RLIMIT_STACK , &reslimit) == 0){ reslimit.rlim_cur = reslimit.rlim_max; (void)setrlimit(RLIMIT_STACK , &reslimit); } /* * not really needed, but doesn't hurt */ if (getrlimit(RLIMIT_RSS , &reslimit) == 0){ reslimit.rlim_cur = reslimit.rlim_max; (void)setrlimit(RLIMIT_RSS , &reslimit); } /* * signal handling to reset stored directory times and modes. Since * we deal with broken pipes via failed writes we ignore it. We also * deal with any file size limit through failed writes. Cpu time * limits are caught and a cleanup is forced. */ if ((sigemptyset(&s_mask) < 0) || (sigaddset(&s_mask, SIGTERM) < 0) || (sigaddset(&s_mask,SIGINT) < 0)||(sigaddset(&s_mask,SIGHUP) < 0) || (sigaddset(&s_mask,SIGPIPE) < 0)||(sigaddset(&s_mask,SIGQUIT)<0) || (sigaddset(&s_mask,SIGXCPU) < 0)||(sigaddset(&s_mask,SIGXFSZ)<0)) { paxwarn(1, "Unable to set up signal mask"); return(-1); } /* snag the fd to be used from the signal handler */ listfd = fileno(listf); memset(&n_hand, 0, sizeof n_hand); n_hand.sa_mask = s_mask; n_hand.sa_flags = 0; n_hand.sa_handler = sig_cleanup; if (setup_sig(SIGHUP, &n_hand) || setup_sig(SIGTERM, &n_hand) || setup_sig(SIGINT, &n_hand) || setup_sig(SIGQUIT, &n_hand) || setup_sig(SIGXCPU, &n_hand)) goto out; n_hand.sa_handler = SIG_IGN; if ((sigaction(SIGPIPE, &n_hand, NULL) == -1) || (sigaction(SIGXFSZ, &n_hand, NULL) == -1)) goto out; return(0); out: syswarn(1, errno, "Unable to set up signal handler"); return(-1); }
