X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=sidebyside;f=libbb%2Fcopy_file.c;h=23c0f8320b86f19f5d1a478368843340bd1bf51b;hb=b05bcaf29c9008799aedb535cb42d2e60cc4cbb9;hp=d71dbf47d5c6cbe2dd95e9f73453847204a03780;hpb=02b8dfc5249303dd489c479aae1087905427a50e;p=oweals%2Fbusybox.git diff --git a/libbb/copy_file.c b/libbb/copy_file.c index d71dbf47d..23c0f8320 100644 --- a/libbb/copy_file.c +++ b/libbb/copy_file.c @@ -3,323 +3,422 @@ * Mini copy_file implementation for busybox * * Copyright (C) 2001 by Matt Kraai + * SELinux support by Yuichi Nakamura * - * 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. - * - * 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 - * General Public License for more details. - * - * 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 - * + * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ +#include "libbb.h" + +// FEATURE_NON_POSIX_CP: +// +// POSIX: if exists and -i, ask (w/o -i assume yes). +// Then open w/o EXCL (yes, not unlink!). +// If open still fails and -f, try unlink, then try open again. +// Result: a mess: +// If dest is a (sym)link, we overwrite link destination! +// (or fail, if it points to dir/nonexistent location/etc). +// This is strange, but POSIX-correct. +// coreutils cp has --remove-destination to override this... + +/* Called if open of destination, link creation etc fails. + * errno must be set to relevant value ("why we cannot create dest?") + * to give reasonable error message */ +static int ask_and_unlink(const char *dest, int flags) +{ + int e = errno; -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "busybox.h" +#if !ENABLE_FEATURE_NON_POSIX_CP + if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) { + /* Either it exists, or the *path* doesnt exist */ + bb_perror_msg("can't create '%s'", dest); + return -1; + } +#endif + // else: act as if -f is always in effect. + // We don't want "can't create" msg, we want unlink to be done + // (silently unless -i). Why? POSIX cp usually succeeds with + // O_TRUNC open of existing file, and user is left ignorantly happy. + // With above block unconditionally enabled, non-POSIX cp + // will complain a lot more than POSIX one. + + /* TODO: maybe we should do it only if ctty is present? */ + if (flags & FILEUTILS_INTERACTIVE) { + // We would not do POSIX insanity. -i asks, + // then _unlinks_ the offender. Presto. + // (No "opening without O_EXCL", no "unlink only if -f") + // Or else we will end up having 3 open()s! + fprintf(stderr, "%s: overwrite '%s'? ", applet_name, dest); + if (!bb_ask_confirmation()) + return 0; /* not allowed to overwrite */ + } + if (unlink(dest) < 0) { +#if ENABLE_FEATURE_VERBOSE_CP_MESSAGE + if (e == errno && e == ENOENT) { + /* e == ENOTDIR is similar: path has non-dir component, + * but in this case we don't even reach copy_file() */ + bb_error_msg("can't create '%s': Path does not exist", dest); + return -1; /* error */ + } +#endif + errno = e; /* do not use errno from unlink */ + bb_perror_msg("can't create '%s'", dest); + return -1; /* error */ + } +#if ENABLE_FEATURE_CP_LONG_OPTIONS + if (flags & FILEUTILS_RMDEST) + if (flags & FILEUTILS_VERBOSE) + printf("removed '%s'\n", dest); +#endif + return 1; /* ok (to try again) */ +} -int copy_file(const char *source, const char *dest, int flags) +/* Return: + * -1 error, copy not made + * 0 copy is made or user answered "no" in interactive mode + * (failures to preserve mode/owner/times are not reported in exit code) + */ +int FAST_FUNC copy_file(const char *source, const char *dest, int flags) { + /* This is a recursive function, try to minimize stack usage */ + /* NB: each struct stat is ~100 bytes */ struct stat source_stat; struct stat dest_stat; - int dest_exists = 1; - int status = 0; - - if ((!(flags & FILEUTILS_DEREFERENCE) && - lstat(source, &source_stat) < 0) || - ((flags & FILEUTILS_DEREFERENCE) && - stat(source, &source_stat) < 0)) { - perror_msg("%s", source); + smallint retval = 0; + smallint dest_exists = 0; + smallint ovr; + +/* Inverse of cp -d ("cp without -d") */ +#define FLAGS_DEREF (flags & (FILEUTILS_DEREFERENCE + FILEUTILS_DEREFERENCE_L0)) + + if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) { + /* This may be a dangling symlink. + * Making [sym]links to dangling symlinks works, so... */ + if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) + goto make_links; + bb_perror_msg("can't stat '%s'", source); return -1; } if (lstat(dest, &dest_stat) < 0) { if (errno != ENOENT) { - perror_msg("unable to stat `%s'", dest); + bb_perror_msg("can't stat '%s'", dest); + return -1; + } + } else { + if (source_stat.st_dev == dest_stat.st_dev + && source_stat.st_ino == dest_stat.st_ino + ) { + bb_error_msg("'%s' and '%s' are the same file", source, dest); return -1; } - dest_exists = 0; + dest_exists = 1; } - if (dest_exists && source_stat.st_dev == dest_stat.st_dev && - source_stat.st_ino == dest_stat.st_ino) { - error_msg("`%s' and `%s' are the same file", source, dest); - return -1; +#if ENABLE_SELINUX + if ((flags & FILEUTILS_PRESERVE_SECURITY_CONTEXT) && is_selinux_enabled() > 0) { + security_context_t con; + if (lgetfilecon(source, &con) >= 0) { + if (setfscreatecon(con) < 0) { + bb_perror_msg("can't set setfscreatecon %s", con); + freecon(con); + return -1; + } + } else if (errno == ENOTSUP || errno == ENODATA) { + setfscreatecon_or_die(NULL); + } else { + bb_perror_msg("can't lgetfilecon %s", source); + return -1; + } } +#endif if (S_ISDIR(source_stat.st_mode)) { DIR *dp; + const char *tp; struct dirent *d; mode_t saved_umask = 0; if (!(flags & FILEUTILS_RECUR)) { - error_msg("%s: omitting directory", source); + bb_error_msg("omitting directory '%s'", source); + return -1; + } + + /* Did we ever create source ourself before? */ + tp = is_in_ino_dev_hashtable(&source_stat); + if (tp) { + /* We did! it's a recursion! man the lifeboats... */ + bb_error_msg("recursion detected, omitting directory '%s'", + source); return -1; } - /* Create DEST. */ if (dest_exists) { if (!S_ISDIR(dest_stat.st_mode)) { - error_msg("`%s' is not a directory", dest); + bb_error_msg("target '%s' is not a directory", dest); return -1; } + /* race here: user can substitute a symlink between + * this check and actual creation of files inside dest */ } else { + /* Create DEST */ mode_t mode; saved_umask = umask(0); mode = source_stat.st_mode; if (!(flags & FILEUTILS_PRESERVE_STATUS)) mode = source_stat.st_mode & ~saved_umask; + /* Allow owner to access new dir (at least for now) */ mode |= S_IRWXU; - if (mkdir(dest, mode) < 0) { umask(saved_umask); - perror_msg("cannot create directory `%s'", dest); + bb_perror_msg("can't create directory '%s'", dest); return -1; } - umask(saved_umask); + /* need stat info for add_to_ino_dev_hashtable */ + if (lstat(dest, &dest_stat) < 0) { + bb_perror_msg("can't stat '%s'", dest); + return -1; + } } - - /* Recursively copy files in SOURCE. */ - if ((dp = opendir(source)) == NULL) { - perror_msg("unable to open directory `%s'", source); - status = -1; - goto end; + /* remember (dev,inode) of each created dir. + * NULL: name is not remembered */ + add_to_ino_dev_hashtable(&dest_stat, NULL); + + /* Recursively copy files in SOURCE */ + dp = opendir(source); + if (dp == NULL) { + retval = -1; + goto preserve_mode_ugid_time; } while ((d = readdir(dp)) != NULL) { char *new_source, *new_dest; - if (strcmp(d->d_name, ".") == 0 || - strcmp(d->d_name, "..") == 0) + new_source = concat_subpath_file(source, d->d_name); + if (new_source == NULL) continue; - - new_source = concat_path_file(source, d->d_name); new_dest = concat_path_file(dest, d->d_name); - if (copy_file(new_source, new_dest, flags) < 0) - status = -1; + if (copy_file(new_source, new_dest, flags & ~FILEUTILS_DEREFERENCE_L0) < 0) + retval = -1; free(new_source); free(new_dest); } + closedir(dp); - /* ??? What if an error occurs in readdir? */ - - if (closedir(dp) < 0) { - perror_msg("unable to close directory `%s'", source); - status = -1; + if (!dest_exists + && chmod(dest, source_stat.st_mode & ~saved_umask) < 0 + ) { + bb_perror_msg("can't preserve %s of '%s'", "permissions", dest); + /* retval = -1; - WRONG! copy *WAS* made */ } + goto preserve_mode_ugid_time; + } - if (!dest_exists && - chmod(dest, source_stat.st_mode & ~saved_umask) < 0) { - perror_msg("unable to change permissions of `%s'", dest); - status = -1; - } - } else if (S_ISREG(source_stat.st_mode)) { - FILE *sfp, *dfp=NULL; -#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS - char *link_name; - - if (!(flags & FILEUTILS_DEREFERENCE) && - is_in_ino_dev_hashtable(&source_stat, &link_name)) { - if (link(link_name, dest) < 0) { - perror_msg("unable to link `%s'", dest); - return -1; + if (dest_exists) { + if (flags & FILEUTILS_UPDATE) { + if (source_stat.st_mtime <= dest_stat.st_mtime) { + return 0; /* source file must be newer */ } - - return 0; - } -#endif - - if ((sfp = fopen(source, "r")) == NULL) { - perror_msg("unable to open `%s'", source); - return -1; } - - if (dest_exists) { - if (flags & FILEUTILS_INTERACTIVE) { - fprintf(stderr, "%s: overwrite `%s'? ", applet_name, dest); - if (!ask_confirmation()) { - fclose (sfp); - return 0; - } - } - - if ((dfp = fopen(dest, "w")) == NULL) { - if (!(flags & FILEUTILS_FORCE)) { - perror_msg("unable to open `%s'", dest); - fclose (sfp); - return -1; - } - - if (unlink(dest) < 0) { - perror_msg("unable to remove `%s'", dest); - fclose (sfp); - return -1; - } - - dest_exists = 0; - } +#if ENABLE_FEATURE_CP_LONG_OPTIONS + if (flags & FILEUTILS_RMDEST) { + ovr = ask_and_unlink(dest, flags); + if (ovr <= 0) + return ovr; + dest_exists = 0; } +#endif + } - if (!dest_exists) { - int fd; - - if ((fd = open(dest, O_WRONLY|O_CREAT, source_stat.st_mode)) < 0 || - (dfp = fdopen(fd, "w")) == NULL) { - if (fd >= 0) - close(fd); - perror_msg("unable to open `%s'", dest); - fclose (sfp); + if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) { + int (*lf)(const char *oldpath, const char *newpath); + make_links: + /* Hmm... maybe + * if (DEREF && MAKE_SOFTLINK) source = realpath(source) ? + * (but realpath returns NULL on dangling symlinks...) */ + lf = (flags & FILEUTILS_MAKE_SOFTLINK) ? symlink : link; + if (lf(source, dest) < 0) { + ovr = ask_and_unlink(dest, flags); + if (ovr <= 0) + return ovr; + if (lf(source, dest) < 0) { + bb_perror_msg("can't create link '%s'", dest); return -1; } } + /* _Not_ jumping to preserve_mode_ugid_time: + * (sym)links don't have those */ + return 0; + } - if (copy_file_chunk(sfp, dfp, -1) < 0) - status = -1; - - if (fclose(dfp) < 0) { - perror_msg("unable to close `%s'", dest); - status = -1; - } - - if (fclose(sfp) < 0) { - perror_msg("unable to close `%s'", source); - status = -1; + if (/* "cp thing1 thing2" without -R: just open and read() from thing1 */ + !(flags & FILEUTILS_RECUR) + /* "cp [-opts] regular_file thing2" */ + || S_ISREG(source_stat.st_mode) + /* DEREF uses stat, which never returns S_ISLNK() == true. + * So the below is never true: */ + /* || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) */ + ) { + int src_fd; + int dst_fd; + mode_t new_mode; + + if (!FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) { + /* "cp -d symlink dst": create a link */ + goto dont_cat; } - } else if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode) || - S_ISSOCK(source_stat.st_mode)) { - - if (dest_exists) { - if (flags & FILEUTILS_INTERACTIVE) { - fprintf(stderr, "%s: overwrite `%s'? ", applet_name, dest); - if (!ask_confirmation()) - return 0; - } - - if (!(flags & FILEUTILS_FORCE)) { - perror_msg("unable to remove `%s'", dest); - return -1; - } - if (unlink(dest) < 0) { - perror_msg("unable to remove `%s'", dest); - return -1; + if (ENABLE_FEATURE_PRESERVE_HARDLINKS && !FLAGS_DEREF) { + const char *link_target; + link_target = is_in_ino_dev_hashtable(&source_stat); + if (link_target) { + if (link(link_target, dest) < 0) { + ovr = ask_and_unlink(dest, flags); + if (ovr <= 0) + return ovr; + if (link(link_target, dest) < 0) { + bb_perror_msg("can't create link '%s'", dest); + return -1; + } + } + return 0; } - - dest_exists = 0; + add_to_ino_dev_hashtable(&source_stat, dest); } - if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) { - perror_msg("unable to create `%s'", dest); + src_fd = open_or_warn(source, O_RDONLY); + if (src_fd < 0) return -1; - } - } else if (S_ISFIFO(source_stat.st_mode)) { - if (dest_exists) { - if (flags & FILEUTILS_INTERACTIVE) { - fprintf(stderr, "%s: overwrite `%s'? ", applet_name, dest); - if (!ask_confirmation()) - return 0; + /* Do not try to open with weird mode fields */ + new_mode = source_stat.st_mode; + if (!S_ISREG(source_stat.st_mode)) + new_mode = 0666; + + if (ENABLE_FEATURE_NON_POSIX_CP || (flags & FILEUTILS_INTERACTIVE)) { + /* + * O_CREAT|O_EXCL: require that file did not exist before creation + */ + dst_fd = open(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode); + } else { /* POSIX, and not "cp -i" */ + /* + * O_CREAT|O_TRUNC: create, or truncate (security problem versus (sym)link attacks) + */ + dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, new_mode); + } + if (dst_fd == -1) { + ovr = ask_and_unlink(dest, flags); + if (ovr <= 0) { + close(src_fd); + return ovr; } - - if (!(flags & FILEUTILS_FORCE)) { - perror_msg("unable to remove `%s'", dest); + /* It shouldn't exist. If it exists, do not open (symlink attack?) */ + dst_fd = open3_or_warn(dest, O_WRONLY|O_CREAT|O_EXCL, new_mode); + if (dst_fd < 0) { + close(src_fd); return -1; } + } - if (unlink(dest) < 0) { - perror_msg("unable to remove `%s'", dest); +#if ENABLE_SELINUX + if ((flags & (FILEUTILS_PRESERVE_SECURITY_CONTEXT|FILEUTILS_SET_SECURITY_CONTEXT)) + && is_selinux_enabled() > 0 + ) { + security_context_t con; + if (getfscreatecon(&con) == -1) { + bb_perror_msg("getfscreatecon"); return -1; } - - dest_exists = 0; + if (con) { + if (setfilecon(dest, con) == -1) { + bb_perror_msg("setfilecon:%s,%s", dest, con); + freecon(con); + return -1; + } + freecon(con); + } } - - if (mkfifo(dest, source_stat.st_mode) < 0) { - perror_msg("cannot create fifo `%s'", dest); - return -1; +#endif + if (bb_copyfd_eof(src_fd, dst_fd) == -1) + retval = -1; + /* Careful with writing... */ + if (close(dst_fd) < 0) { + bb_perror_msg("error writing to '%s'", dest); + retval = -1; } - } else if (S_ISLNK(source_stat.st_mode)) { - char *lpath; - - if (dest_exists) { - if (flags & FILEUTILS_INTERACTIVE) { - fprintf(stderr, "%s: overwrite `%s'? ", applet_name, dest); - if (!ask_confirmation()) - return 0; - } - - if (!(flags & FILEUTILS_FORCE)) { - perror_msg("unable to remove `%s'", dest); - return -1; - } - - if (unlink(dest) < 0) { - perror_msg("unable to remove `%s'", dest); + /* ...but read size is already checked by bb_copyfd_eof */ + close(src_fd); + /* "cp /dev/something new_file" should not + * copy mode of /dev/something */ + if (!S_ISREG(source_stat.st_mode)) + return retval; + goto preserve_mode_ugid_time; + } + dont_cat: + + /* Source is a symlink or a special file */ + /* We are lazy here, a bit lax with races... */ + if (dest_exists) { + errno = EEXIST; + ovr = ask_and_unlink(dest, flags); + if (ovr <= 0) + return ovr; + } + if (S_ISLNK(source_stat.st_mode)) { + char *lpath = xmalloc_readlink_or_warn(source); + if (lpath) { + int r = symlink(lpath, dest); + free(lpath); + if (r < 0) { + bb_perror_msg("can't create symlink '%s'", dest); return -1; } - - dest_exists = 0; + if (flags & FILEUTILS_PRESERVE_STATUS) + if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0) + bb_perror_msg("can't preserve %s of '%s'", "ownership", dest); } - - lpath = xreadlink(source); - if (symlink(lpath, dest) < 0) { - perror_msg("cannot create symlink `%s'", dest); + /* _Not_ jumping to preserve_mode_ugid_time: + * symlinks don't have those */ + goto verb_and_exit; + } + if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode) + || S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode) + ) { + if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) { + bb_perror_msg("can't create '%s'", dest); return -1; } - free(lpath); - -#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1) - if (flags & FILEUTILS_PRESERVE_STATUS) - if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0) - perror_msg("unable to preserve ownership of `%s'", dest); -#endif - -#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS - add_to_ino_dev_hashtable(&source_stat, dest); -#endif - - return 0; } else { - error_msg("internal error: unrecognized file type"); + bb_error_msg("unrecognized file '%s' with mode %x", source, source_stat.st_mode); return -1; } -#ifdef CONFIG_FEATURE_PRESERVE_HARDLINKS - add_to_ino_dev_hashtable(&source_stat, dest); -#endif + preserve_mode_ugid_time: -end: + if (flags & FILEUTILS_PRESERVE_STATUS + /* Cannot happen: */ + /* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */ + ) { + struct timeval times[2]; - if (flags & FILEUTILS_PRESERVE_STATUS) { - struct utimbuf times; - - times.actime = source_stat.st_atime; - times.modtime = source_stat.st_mtime; - if (utime(dest, ×) < 0) - perror_msg("unable to preserve times of `%s'", dest); + times[1].tv_sec = times[0].tv_sec = source_stat.st_mtime; + times[1].tv_usec = times[0].tv_usec = 0; + /* BTW, utimes sets usec-precision time - just FYI */ + if (utimes(dest, times) < 0) + bb_perror_msg("can't preserve %s of '%s'", "times", dest); if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) { source_stat.st_mode &= ~(S_ISUID | S_ISGID); - perror_msg("unable to preserve ownership of `%s'", dest); + bb_perror_msg("can't preserve %s of '%s'", "ownership", dest); } if (chmod(dest, source_stat.st_mode) < 0) - perror_msg("unable to preserve permissions of `%s'", dest); + bb_perror_msg("can't preserve %s of '%s'", "permissions", dest); + } + + verb_and_exit: + if (flags & FILEUTILS_VERBOSE) { + printf("'%s' -> '%s'\n", source, dest); } - return status; + return retval; }