added --backup-dir option from Bob Edwards

[rsync/rsync.git] / rsync.c

/* 
   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"

extern int verbose;
extern int dry_run;
extern int preserve_times;
extern int am_root;
extern int preserve_uid;
extern int preserve_gid;
extern int preserve_perms;
extern int make_backups;


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


/*
 * delete a file or directory. If force_delet is set then delete 
 * recursively 
 */
int delete_file(char *fname)
{
	DIR *d;
	struct dirent *di;
	char buf[MAXPATHLEN];
	extern int force_delete;
	STRUCT_STAT st;
	int ret;
	extern int recurse;

	if (robust_unlink(fname) == 0 || errno == ENOENT) return 0;

#if SUPPORT_LINKS
	ret = do_lstat(fname, &st);
#else
	ret = do_stat(fname, &st);
#endif
	if (ret) {
		rprintf(FERROR,"stat(%s) : %s\n", fname, strerror(errno));
		return -1;
	}

	if (!S_ISDIR(st.st_mode)) {
		rprintf(FERROR,"unlink(%s) : %s\n", fname, strerror(errno));
		return -1;
	}

	if (do_rmdir(fname) == 0 || errno == ENOENT) return 0;
	if (!force_delete || !recurse || 
	    (errno != ENOTEMPTY && errno != EEXIST)) {
		rprintf(FERROR,"rmdir(%s) : %s\n", fname, strerror(errno));
		return -1;
	}

	/* now we do a recsursive delete on the directory ... */
	d = opendir(fname);
	if (!d) {
		rprintf(FERROR,"opendir(%s): %s\n",
			fname,strerror(errno));
		return -1;
	}

	for (di=readdir(d); di; di=readdir(d)) {
		char *dname = d_name(di);
		if (strcmp(dname,".")==0 ||
		    strcmp(dname,"..")==0)
			continue;
		slprintf(buf, sizeof(buf), "%s/%s", fname, dname);
		if (verbose > 0)
			rprintf(FINFO,"deleting %s\n", buf);
		if (delete_file(buf) != 0) {
			closedir(d);
			return -1;
		}
	}	

	closedir(d);
	
	if (do_rmdir(fname) != 0) {
		rprintf(FERROR,"rmdir(%s) : %s\n", fname, strerror(errno));
		return -1;
	}

	return 0;
}

static int is_in_group(gid_t gid)
{
#ifdef GETGROUPS_T
	static gid_t last_in = (gid_t) -2, last_out;
	static int ngroups = -2;
	static GETGROUPS_T *gidset;
	int n;

	if (gid == last_in)
		return last_out;
	if (ngroups < -1) {
		/* treat failure (-1) as if not member of any group */
		ngroups = getgroups(0, 0);
		if (ngroups > 0) {
			gidset = (GETGROUPS_T *) malloc(ngroups * sizeof(GETGROUPS_T));
			ngroups = getgroups(ngroups, gidset);
		}
	}

	last_in = gid;
	last_out = 0;
	for (n = 0; n < ngroups; n++) {
		if (gidset[n] == gid) {
			last_out = 1;
			break;
		}
	}
	return last_out;

#else
	return 0;
#endif
}

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

	if (dry_run) return 0;

	if (!st) {
		if (link_stat(fname,&st2) != 0) {
			rprintf(FERROR,"stat %s : %s\n",fname,strerror(errno));
			return 0;
		}
		st = &st2;
	}

	if (preserve_times && !S_ISLNK(st->st_mode) &&
	    st->st_mtime != file->modtime) {
		/* don't complain about not setting times on directories
		   because some filesystems can't do it */
		if (set_modtime(fname,file->modtime) != 0 &&
		    !S_ISDIR(st->st_mode)) {
			rprintf(FERROR,"failed to set times on %s : %s\n",
				fname,strerror(errno));
			return 0;
		} else {
			updated = 1;
		}
	}

	change_uid = am_root && preserve_uid && st->st_uid != file->uid;
	change_gid = preserve_gid && file->gid != (gid_t) -1 && \
				st->st_gid != file->gid;
	if (change_gid && !am_root) {
		/* enforce bsd-style group semantics: non-root can only
		    change to groups that the user is a member of */
		change_gid = is_in_group(file->gid);
	}
	if (change_uid || change_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 */
			rprintf(FERROR,"chown %s : %s\n", fname,strerror(errno));
			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);
		}
		updated = 1;
	}

#ifdef HAVE_CHMOD
	if (!S_ISLNK(st->st_mode)) {
		if (st->st_mode != file->mode) {
			updated = 1;
			if (do_chmod(fname,file->mode) != 0) {
				rprintf(FERROR,"failed to set permissions on %s : %s\n",
					fname,strerror(errno));
				return 0;
			}
		}
	}
#endif
    
	if (verbose > 1 && report) {
		if (updated)
			rprintf(FINFO,"%s\n",fname);
		else
			rprintf(FINFO,"%s is uptodate\n",fname);
	}
	return updated;
}


void sig_int(void)
{
	exit_cleanup(RERR_SIGNAL);
}


/* finish off a file transfer, renaming the file and setting the permissions
   and ownership */
void finish_transfer(char *fname, char *fnametmp, struct file_struct *file)
{
	if (make_backups && !make_backup(fname))
		return;

	/* move tmp file over real file */
	if (robust_rename(fnametmp,fname) != 0) {
		if (errno == EXDEV) {
			/* rename failed on cross-filesystem link.  
			   Copy the file instead. */
			if (copy_file(fnametmp,fname, file->mode & INITACCESSPERMS)) {
				rprintf(FERROR,"copy %s -> %s : %s\n",
					fnametmp,fname,strerror(errno));
			} else {
				set_perms(fname,file,NULL,0);
			}
		} else {
			rprintf(FERROR,"rename %s -> %s : %s\n",
				fnametmp,fname,strerror(errno));
		}
		do_unlink(fnametmp);
	} else {
		set_perms(fname,file,NULL,0);
	}
}