rsync.c

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/*
   Copyright (C) Andrew Tridgell 1996
   Copyright (C) Paul Mackerras 1996

   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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/* this file contains code used by more than one part of the rsync
   process */

#include "rsync.h"
#if defined HAVE_ICONV_OPEN && defined HAVE_ICONV_H
#include <iconv.h>
#endif
#if defined HAVE_LIBCHARSET_H && defined HAVE_LOCALE_CHARSET
#include <libcharset.h>
#elif defined HAVE_LANGINFO_H && defined HAVE_NL_LANGINFO
#include <langinfo.h>
#endif

extern int verbose;
extern int dry_run;
extern int daemon_log_format_has_i;
extern int preserve_acls;
extern int preserve_xattrs;
extern int preserve_perms;
extern int preserve_executability;
extern int preserve_times;
extern int omit_dir_times;
extern int am_root;
extern int am_server;
extern int am_sender;
extern int am_generator;
extern int am_starting_up;
extern int allow_8bit_chars;
extern int preserve_uid;
extern int preserve_gid;
extern int inplace;
extern int keep_dirlinks;
extern int make_backups;
extern mode_t orig_umask;
extern struct stats stats;
extern struct chmod_mode_struct *daemon_chmod_modes;

#if defined HAVE_ICONV_OPEN && defined HAVE_ICONV_H
iconv_t ic_chck = (iconv_t)-1;

static const char *default_charset(void)
{
#if defined HAVE_LIBCHARSET_H && defined HAVE_LOCALE_CHARSET
        return locale_charset();
#elif defined HAVE_LANGINFO_H && defined HAVE_NL_LANGINFO
        return nl_langinfo(CODESET);
#else
        return ""; /* Works with (at the very least) gnu iconv... */
#endif
}

void setup_iconv()
{
        if (!am_server && !allow_8bit_chars) {
                const char *defset = default_charset();

                /* It's OK if this fails... */
                ic_chck = iconv_open(defset, defset);

                if (verbose > 3) {
                        if (ic_chck == (iconv_t)-1) {
                                rprintf(FINFO,
                                        "note: iconv_open(\"%s\", \"%s\") failed (%d)"
                                        " -- using isprint() instead of iconv().\n",
                                        defset, defset, errno);
                        } else {
                                rprintf(FINFO,
                                        "note: iconv_open(\"%s\", \"%s\") succeeded.\n",
                                        defset, defset);
                        }
                }
        }
}
#endif

/*
  free a sums struct
  */
void free_sums(struct sum_struct *s)
{
        if (s->sums) free(s->sums);
        free(s);
}

/* This is only called when we aren't preserving permissions.  Figure out what
 * the permissions should be and return them merged back into the mode. */
mode_t dest_mode(mode_t flist_mode, mode_t cur_mode, int dflt_perms,
                 int exists)
{
        /* If the file already exists, we'll return the local permissions,
         * possibly tweaked by the --executability option. */
        if (exists) {
                if (preserve_executability && S_ISREG(flist_mode)) {
                        /* If the source file is executable, grant execute
                         * rights to everyone who can read, but ONLY if the
                         * file isn't already executable. */
                        if (!(flist_mode & 0111))
                                cur_mode &= ~0111;
                        else if (!(cur_mode & 0111))
                                cur_mode |= (cur_mode & 0444) >> 2;
                }
        } else
                cur_mode = flist_mode & ACCESSPERMS & dflt_perms;
        if (daemon_chmod_modes && !S_ISLNK(flist_mode))
                cur_mode = tweak_mode(cur_mode, daemon_chmod_modes);
        return (flist_mode & ~CHMOD_BITS) | (cur_mode & CHMOD_BITS);
}

int set_file_attrs(char *fname, struct file_struct *file, STRUCT_STAT *st,
                   int flags)
{
        int updated = 0;
        STRUCT_STAT st2;
        int change_uid, change_gid;

        if (!st) {
                if (dry_run)
                        return 1;
                if (link_stat(fname, &st2, 0) < 0) {
                        rsyserr(FERROR, errno, "stat %s failed",
                                full_fname(fname));
                        return 0;
                }
                st = &st2;
                if (!preserve_perms && S_ISDIR(file->mode)
                 && st->st_mode & S_ISGID) {
                        /* We just created this directory and its setgid
                         * bit is on, so make sure it stays on. */
                        file->mode |= S_ISGID;
                }
        }

        if (!preserve_times || (S_ISDIR(st->st_mode) && omit_dir_times))
                flags |= ATTRS_SKIP_MTIME;
        if (!(flags & ATTRS_SKIP_MTIME)
            && cmp_time(st->st_mtime, file->modtime) != 0) {
                int ret = set_modtime(fname, file->modtime, st->st_mode);
                if (ret < 0) {
                        rsyserr(FERROR, errno, "failed to set times on %s",
                                full_fname(fname));
                        return 0;
                }
                if (ret == 0) /* ret == 1 if symlink could not be set */
                        updated = 1;
        }

        change_uid = am_root && preserve_uid && st->st_uid != file->uid;
        change_gid = preserve_gid && file->gid != GID_NONE
                && st->st_gid != file->gid;
#if !defined HAVE_LCHOWN && !defined CHOWN_MODIFIES_SYMLINK
        if (S_ISLNK(st->st_mode))
                ;
        else
#endif
        if (change_uid || change_gid) {
                if (verbose > 2) {
                        if (change_uid) {
                                rprintf(FINFO,
                                        "set uid of %s from %ld to %ld\n",
                                        fname,
                                        (long)st->st_uid, (long)file->uid);
                        }
                        if (change_gid) {
                                rprintf(FINFO,
                                        "set gid of %s from %ld to %ld\n",
                                        fname,
                                        (long)st->st_gid, (long)file->gid);
                        }
                }
                if (do_lchown(fname,
                    change_uid ? file->uid : st->st_uid,
                    change_gid ? file->gid : st->st_gid) != 0) {
                        /* shouldn't have attempted to change uid or gid
                         * unless have the privilege */
                        rsyserr(FERROR, errno, "%s %s failed",
                            change_uid ? "chown" : "chgrp",
                            full_fname(fname));
                        return 0;
                }
                /* a lchown had been done - we have to re-stat if the
                 * destination had the setuid or setgid bits set due
                 * to the side effect of the chown call */
                if (st->st_mode & (S_ISUID | S_ISGID)) {
                        link_stat(fname, st,
                                  keep_dirlinks && S_ISDIR(st->st_mode));
                }
                updated = 1;
        }

#ifdef SUPPORT_ACLS
        /* It's OK to call set_acl() now, even for a dir, as the generator
         * will enable owner-writability using chmod, if necessary.
         * 
         * If set_acl changes permission bits in the process of setting
         * an access ACL, it changes st->st_mode so we know whether we
         * need to chmod. */
        if (preserve_acls && set_acl(fname, file, &st->st_mode) == 0)
                updated = 1;
#endif
#ifdef SUPPORT_XATTRS
        if (preserve_xattrs && set_xattr(fname, file) == 0)
                updated = 1;
#endif

#ifdef HAVE_CHMOD
        if ((st->st_mode & CHMOD_BITS) != (file->mode & CHMOD_BITS)) {
                int ret = do_chmod(fname, file->mode);
                if (ret < 0) {
                        rsyserr(FERROR, errno,
                                "failed to set permissions on %s",
                                full_fname(fname));
                        return 0;
                }
                if (ret == 0) /* ret == 1 if symlink could not be set */
                        updated = 1;
        }
#endif

        if (verbose > 1 && flags & ATTRS_REPORT) {
                enum logcode code = daemon_log_format_has_i || dry_run
                                  ? FCLIENT : FINFO;
                if (updated)
                        rprintf(code, "%s\n", fname);
                else
                        rprintf(code, "%s is uptodate\n", fname);
        }
        return updated;
}

RETSIGTYPE sig_int(UNUSED(int val))
{
        /* KLUGE: if the user hits Ctrl-C while ssh is prompting
         * for a password, then our cleanup's sending of a SIGUSR1
         * signal to all our children may kill ssh before it has a
         * chance to restore the tty settings (i.e. turn echo back
         * on).  By sleeping for a short time, ssh gets a bigger
         * chance to do the right thing.  If child processes are
         * not ssh waiting for a password, then this tiny delay
         * shouldn't hurt anything. */
        msleep(400);
        exit_cleanup(RERR_SIGNAL);
}

/* Finish off a file transfer: renaming the file and setting the file's
 * attributes (e.g. permissions, ownership, etc.).  If partialptr is not
 * NULL and the robust_rename() call is forced to copy the temp file, we
 * stage the file into the partial-dir and then rename it into place. */
void finish_transfer(char *fname, char *fnametmp, char *partialptr,
                     struct file_struct *file, int ok_to_set_time,
                     int overwriting_basis)
{
        int ret;

        if (inplace) {
                if (verbose > 2)
                        rprintf(FINFO, "finishing %s\n", fname);
                fnametmp = fname;
                goto do_set_file_attrs;
        }

        if (make_backups && overwriting_basis && !make_backup(fname))
                return;

        /* Change permissions before putting the file into place. */
        set_file_attrs(fnametmp, file, NULL,
                       ok_to_set_time ? 0 : ATTRS_SKIP_MTIME);

        /* move tmp file over real file */
        if (verbose > 2)
                rprintf(FINFO, "renaming %s to %s\n", fnametmp, fname);
        ret = robust_rename(fnametmp, fname, partialptr,
                            file->mode & INITACCESSPERMS);
        if (ret < 0) {
                rsyserr(FERROR, errno, "%s %s -> \"%s\"",
                        ret == -2 ? "copy" : "rename",
                        full_fname(fnametmp), fname);
                do_unlink(fnametmp);
                return;
        }
        if (ret == 0) {
                /* The file was moved into place (not copied), so it's done. */
                return;
        }
        /* The file was copied, so tweak the perms of the copied file.  If it
         * was copied to partialptr, move it into its final destination. */
        fnametmp = partialptr ? partialptr : fname;

  do_set_file_attrs:
        set_file_attrs(fnametmp, file, NULL,
                       ok_to_set_time ? 0 : ATTRS_SKIP_MTIME);

        if (partialptr) {
                if (do_rename(fnametmp, fname) < 0) {
                        rsyserr(FERROR, errno, "rename %s -> \"%s\"",
                                full_fname(fnametmp), fname);
                } else
                        handle_partial_dir(partialptr, PDIR_DELETE);
        }
}

const char *who_am_i(void)
{
        if (am_starting_up)
                return am_server ? "server" : "client";
        return am_sender ? "sender" : am_generator ? "generator" : "receiver";
}

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