util.c

Rsync 3.0.5 source code

/*
 * Utility routines used in rsync.
 *
 * Copyright (C) 1996-2000 Andrew Tridgell
 * Copyright (C) 1996 Paul Mackerras
 * Copyright (C) 2001, 2002 Martin Pool <[e-mail]>
 * Copyright (C) 2003-2008 Wayne Davison
 *
 * 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 3 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, visit the http://fsf.org website.
 */

#include "rsync.h"
#include "ifuncs.h"

extern int verbose;
extern int dry_run;
extern int module_id;
extern int modify_window;
extern int relative_paths;
extern int human_readable;
extern int preserve_xattrs;
extern char *module_dir;
extern unsigned int module_dirlen;
extern mode_t orig_umask;
extern char *partial_dir;
extern struct filter_list_struct daemon_filter_list;

int sanitize_paths = 0;

char curr_dir[MAXPATHLEN];
unsigned int curr_dir_len;
int curr_dir_depth; /* This is only set for a sanitizing daemon. */

/* Set a fd into nonblocking mode. */
void set_nonblocking(int fd)
{
	int val;

	if ((val = fcntl(fd, F_GETFL)) == -1)
		return;
	if (!(val & NONBLOCK_FLAG)) {
		val |= NONBLOCK_FLAG;
		fcntl(fd, F_SETFL, val);
	}
}

/* Set a fd into blocking mode. */
void set_blocking(int fd)
{
	int val;

	if ((val = fcntl(fd, F_GETFL)) == -1)
		return;
	if (val & NONBLOCK_FLAG) {
		val &= ~NONBLOCK_FLAG;
		fcntl(fd, F_SETFL, val);
	}
}

/**
 * Create a file descriptor pair - like pipe() but use socketpair if
 * possible (because of blocking issues on pipes).
 *
 * Always set non-blocking.
 */
int fd_pair(int fd[2])
{
	int ret;

#ifdef HAVE_SOCKETPAIR
	ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
#else
	ret = pipe(fd);
#endif

	if (ret == 0) {
		set_nonblocking(fd[0]);
		set_nonblocking(fd[1]);
	}

	return ret;
}

void print_child_argv(const char *prefix, char **cmd)
{
	rprintf(FCLIENT, "%s ", prefix);
	for (; *cmd; cmd++) {
		/* Look for characters that ought to be quoted.  This
		* is not a great quoting algorithm, but it's
		* sufficient for a log message. */
		if (strspn(*cmd, "abcdefghijklmnopqrstuvwxyz"
			   "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
			   "0123456789"
			   ",.-_=+@/") != strlen(*cmd)) {
			rprintf(FCLIENT, "\"%s\" ", *cmd);
		} else {
			rprintf(FCLIENT, "%s ", *cmd);
		}
	}
	rprintf(FCLIENT, "\n");
}

NORETURN void out_of_memory(const char *str)
{
	rprintf(FERROR, "ERROR: out of memory in %s [%s]\n", str, who_am_i());
	exit_cleanup(RERR_MALLOC);
}

NORETURN void overflow_exit(const char *str)
{
	rprintf(FERROR, "ERROR: buffer overflow in %s [%s]\n", str, who_am_i());
	exit_cleanup(RERR_MALLOC);
}

int set_modtime(const char *fname, time_t modtime, mode_t mode)
{
#if !defined HAVE_LUTIMES || !defined HAVE_UTIMES
	if (S_ISLNK(mode))
		return 1;
#endif

	if (verbose > 2) {
		rprintf(FINFO, "set modtime of %s to (%ld) %s",
			fname, (long)modtime,
			asctime(localtime(&modtime)));
	}

	if (dry_run)
		return 0;

	{
#ifdef HAVE_UTIMES
		struct timeval t[2];
		t[0].tv_sec = time(NULL);
		t[0].tv_usec = 0;
		t[1].tv_sec = modtime;
		t[1].tv_usec = 0;
# ifdef HAVE_LUTIMES
		if (S_ISLNK(mode)) {
			if (lutimes(fname, t) < 0)
				return errno == ENOSYS ? 1 : -1;
			return 0;
		}
# endif
		return utimes(fname, t);
#elif defined HAVE_STRUCT_UTIMBUF
		struct utimbuf tbuf;
		tbuf.actime = time(NULL);
		tbuf.modtime = modtime;
		return utime(fname,&tbuf);
#elif defined HAVE_UTIME
		time_t t[2];
		t[0] = time(NULL);
		t[1] = modtime;
		return utime(fname,t);
#else
#error No file-time-modification routine found!
#endif
	}
}

/* This creates a new directory with default permissions.  Since there
 * might be some directory-default permissions affecting this, we can't
 * force the permissions directly using the original umask and mkdir(). */
int mkdir_defmode(char *fname)
{
	int ret;

	umask(orig_umask);
	ret = do_mkdir(fname, ACCESSPERMS);
	umask(0);

	return ret;
}

/* Create any necessary directories in fname.  Any missing directories are
 * created with default permissions. */
int create_directory_path(char *fname)
{
	char *p;
	int ret = 0;

	while (*fname == '/')
		fname++;
	while (strncmp(fname, "./", 2) == 0)
		fname += 2;

	umask(orig_umask);
	p = fname;
	while ((p = strchr(p,'/')) != NULL) {
		*p = '\0';
		if (do_mkdir(fname, ACCESSPERMS) < 0 && errno != EEXIST)
		    ret = -1;
		*p++ = '/';
	}
	umask(0);

	return ret;
}

/**
 * Write @p len bytes at @p ptr to descriptor @p desc, retrying if
 * interrupted.
 *
 * @retval len upon success
 *
 * @retval <0 write's (negative) error code
 *
 * Derived from GNU C's cccp.c.
 */
int full_write(int desc, const char *ptr, size_t len)
{
	int total_written;

	total_written = 0;
	while (len > 0) {
		int written = write(desc, ptr, len);
		if (written < 0)  {
			if (errno == EINTR)
				continue;
			return written;
		}
		total_written += written;
		ptr += written;
		len -= written;
	}
	return total_written;
}

/**
 * Read @p len bytes at @p ptr from descriptor @p desc, retrying if
 * interrupted.
 *
 * @retval >0 the actual number of bytes read
 *
 * @retval 0 for EOF
 *
 * @retval <0 for an error.
 *
 * Derived from GNU C's cccp.c. */
static int safe_read(int desc, char *ptr, size_t len)
{
	int n_chars;

	if (len == 0)
		return len;

	do {
		n_chars = read(desc, ptr, len);
	} while (n_chars < 0 && errno == EINTR);

	return n_chars;
}

/* Copy a file.  If ofd < 0, copy_file unlinks and opens the "dest" file.
 * Otherwise, it just writes to and closes the provided file descriptor.
 * In either case, if --xattrs are being preserved, the dest file will
 * have its xattrs set from the source file.
 *
 * This is used in conjunction with the --temp-dir, --backup, and
 * --copy-dest options. */
int copy_file(const char *source, const char *dest, int ofd,
	      mode_t mode, int create_bak_dir)
{
	int ifd;
	char buf[1024 * 8];
	int len;   /* Number of bytes read into `buf'. */

	if ((ifd = do_open(source, O_RDONLY, 0)) < 0) {
		int save_errno = errno;
		rsyserr(FERROR_XFER, errno, "open %s", full_fname(source));
		errno = save_errno;
		return -1;
	}

	if (ofd < 0) {
		if (robust_unlink(dest) && errno != ENOENT) {
			int save_errno = errno;
			rsyserr(FERROR_XFER, errno, "unlink %s", full_fname(dest));
			errno = save_errno;
			return -1;
		}

		if ((ofd = do_open(dest, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, mode)) < 0) {
			int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
			if (create_bak_dir && errno == ENOENT && make_bak_dir(dest) == 0) {
				if ((ofd = do_open(dest, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, mode)) < 0)
					save_errno = errno ? errno : save_errno;
				else
					save_errno = 0;
			}
			if (save_errno) {
				rsyserr(FERROR_XFER, save_errno, "open %s", full_fname(dest));
				close(ifd);
				errno = save_errno;
				return -1;
			}
		}
	}

	while ((len = safe_read(ifd, buf, sizeof buf)) > 0) {
		if (full_write(ofd, buf, len) < 0) {
			int save_errno = errno;
			rsyserr(FERROR_XFER, errno, "write %s", full_fname(dest));
			close(ifd);
			close(ofd);
			errno = save_errno;
			return -1;
		}
	}

	if (len < 0) {
		int save_errno = errno;
		rsyserr(FERROR_XFER, errno, "read %s", full_fname(source));
		close(ifd);
		close(ofd);
		errno = save_errno;
		return -1;
	}

	if (close(ifd) < 0) {
		rsyserr(FWARNING, errno, "close failed on %s",
			full_fname(source));
	}

	if (close(ofd) < 0) {
		int save_errno = errno;
		rsyserr(FERROR_XFER, errno, "close failed on %s",
			full_fname(dest));
		errno = save_errno;
		return -1;
	}

#ifdef SUPPORT_XATTRS
	if (preserve_xattrs)
		copy_xattrs(source, dest);
#endif

	return 0;
}

/* MAX_RENAMES should be 10**MAX_RENAMES_DIGITS */
#define MAX_RENAMES_DIGITS 3
#define MAX_RENAMES 1000

/**
 * Robust unlink: some OS'es (HPUX) refuse to unlink busy files, so
 * rename to <path>/.rsyncNNN instead.
 *
 * Note that successive rsync runs will shuffle the filenames around a
 * bit as long as the file is still busy; this is because this function
 * does not know if the unlink call is due to a new file coming in, or
 * --delete trying to remove old .rsyncNNN files, hence it renames it
 * each time.
 **/
int robust_unlink(const char *fname)
{
#ifndef ETXTBSY
	return do_unlink(fname);
#else
	static int counter = 1;
	int rc, pos, start;
	char path[MAXPATHLEN];

	rc = do_unlink(fname);
	if (rc == 0 || errno != ETXTBSY)
		return rc;

	if ((pos = strlcpy(path, fname, MAXPATHLEN)) >= MAXPATHLEN)
		pos = MAXPATHLEN - 1;

	while (pos > 0 && path[pos-1] != '/')
		pos--;
	pos += strlcpy(path+pos, ".rsync", MAXPATHLEN-pos);

	if (pos > (MAXPATHLEN-MAX_RENAMES_DIGITS-1)) {
		errno = ETXTBSY;
		return -1;
	}

	/* start where the last one left off to reduce chance of clashes */
	start = counter;
	do {
		snprintf(&path[pos], MAX_RENAMES_DIGITS+1, "%03d", counter);
		if (++counter >= MAX_RENAMES)
			counter = 1;
	} while ((rc = access(path, 0)) == 0 && counter != start);

	if (verbose > 0) {
		rprintf(FWARNING, "renaming %s to %s because of text busy\n",
			fname, path);
	}

	/* maybe we should return rename()'s exit status? Nah. */
	if (do_rename(fname, path) != 0) {
		errno = ETXTBSY;
		return -1;
	}
	return 0;
#endif
}

/* Returns 0 on successful rename, 1 if we successfully copied the file
 * across filesystems, -2 if copy_file() failed, and -1 on other errors.
 * If partialptr is not NULL and we need to do a copy, copy the file into
 * the active partial-dir instead of over the destination file. */
int robust_rename(const char *from, const char *to, const char *partialptr,
		  int mode)
{
	int tries = 4;

	while (tries--) {
		if (do_rename(from, to) == 0)
			return 0;

		switch (errno) {
#ifdef ETXTBSY
		case ETXTBSY:
			if (robust_unlink(to) != 0) {
				errno = ETXTBSY;
				return -1;
			}
			errno = ETXTBSY;
			break;
#endif
		case EXDEV:
			if (partialptr) {
				if (!handle_partial_dir(partialptr,PDIR_CREATE))
					return -2;
				to = partialptr;
			}
			if (copy_file(from, to, -1, mode, 0) != 0)
				return -2;
			do_unlink(from);
			return 1;
		default:
			return -1;
		}
	}
	return -1;
}

static pid_t all_pids[10];
static int num_pids;

/** Fork and record the pid of the child. **/
pid_t do_fork(void)
{
	pid_t newpid = fork();

	if (newpid != 0  &&  newpid != -1) {
		all_pids[num_pids++] = newpid;
	}
	return newpid;
}

/**
 * Kill all children.
 *
 * @todo It would be kind of nice to make sure that they are actually
 * all our children before we kill them, because their pids may have
 * been recycled by some other process.  Perhaps when we wait for a
 * child, we should remove it from this array.  Alternatively we could
 * perhaps use process groups, but I think that would not work on
 * ancient Unix versions that don't support them.
 **/
void kill_all(int sig)
{
	int i;

	for (i = 0; i < num_pids; i++) {
		/* Let's just be a little careful where we
		 * point that gun, hey?  See kill(2) for the
		 * magic caused by negative values. */
		pid_t p = all_pids[i];

		if (p == getpid())
			continue;
		if (p <= 0)
			continue;

		kill(p, sig);
	}
}

/** Turn a user name into a uid */
int name_to_uid(const char *name, uid_t *uid_p)
{
	struct passwd *pass;
	if (!name || !*name)
		return 0;
	if (!(pass = getpwnam(name)))
		return 0;
	*uid_p = pass->pw_uid;
	return 1;
}

/** Turn a group name into a gid */
int name_to_gid(const char *name, gid_t *gid_p)
{
	struct group *grp;
	if (!name || !*name)
		return 0;
	if (!(grp = getgrnam(name)))
		return 0;
	*gid_p = grp->gr_gid;
	return 1;
}

/** Lock a byte range in a open file */
int lock_range(int fd, int offset, int len)
{
	struct flock lock;

	lock.l_type = F_WRLCK;
	lock.l_whence = SEEK_SET;
	lock.l_start = offset;
	lock.l_len = len;
	lock.l_pid = 0;

	return fcntl(fd,F_SETLK,&lock) == 0;
}

#define ENSURE_MEMSPACE(buf, type, sz, req) \
	if ((req) > sz && !(buf = realloc_array(buf, type, sz = MAX(sz * 2, req)))) \
		out_of_memory("glob_expand")

static inline void call_glob_match(const char *name, int len, int from_glob,
				   char *arg, int abpos, int fbpos);

static struct glob_data {
	char *arg_buf, *filt_buf, **argv;
	int absize, fbsize, maxargs, argc;
} glob;

static void glob_match(char *arg, int abpos, int fbpos)
{
	int len;
	char *slash;

	while (*arg == '.' && arg[1] == '/') {
		if (fbpos < 0) {
			ENSURE_MEMSPACE(glob.filt_buf, char, glob.fbsize, glob.absize);
			memcpy(glob.filt_buf, glob.arg_buf, abpos + 1);
			fbpos = abpos;
		}
		ENSURE_MEMSPACE(glob.arg_buf, char, glob.absize, abpos + 3);
		glob.arg_buf[abpos++] = *arg++;
		glob.arg_buf[abpos++] = *arg++;
		glob.arg_buf[abpos] = '\0';
	}
	if ((slash = strchr(arg, '/')) != NULL) {
		*slash = '\0';
		len = slash - arg;
	} else