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rsync.c

Go to the documentation of this file.

/* 
   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_delete 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 SUPPORT_LINKS
        ret = do_lstat(fname, &st);
#else
        ret = do_stat(fname, &st);
#endif
        if (ret) {
                return -1;
        }

        if (!S_ISDIR(st.st_mode)) {
                if (robust_unlink(fname) == 0 || errno == ENOENT) return 0;
                rprintf(FERROR,"delete_file: 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,"delete_file: 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,"delete_file: 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;
                snprintf(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,"delete_file: 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) &&
            cmp_modtime(st->st_mtime, file->modtime) != 0) {
                /* 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);
        }
}

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