fixed a race condition in rsync that opened a security hole. The

[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.
*/

#include "rsync.h"

extern int csum_length;

extern int verbose;
extern int am_server;
extern int always_checksum;
extern time_t starttime;

extern int remote_version;

extern char *backup_suffix;
extern char *tmpdir;

extern int whole_file;
extern int block_size;
extern int update_only;
extern int make_backups;
extern int preserve_links;
extern int preserve_hard_links;
extern int preserve_perms;
extern int preserve_devices;
extern int preserve_uid;
extern int preserve_gid;
extern int preserve_times;
extern int dry_run;
extern int ignore_times;
extern int recurse;
extern int delete_mode;
extern int cvs_exclude;
extern int am_root;
extern int relative_paths;
extern int io_timeout;
extern int io_error;
extern struct stats stats;

/*
  free a sums struct
  */
static 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 
 */
static 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 (do_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)-1, "%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;
}

/*
  send a sums struct down a fd
  */
static void send_sums(struct sum_struct *s,int f_out)
{
  int i;

  /* tell the other guy how many we are going to be doing and how many
     bytes there are in the last chunk */
  write_int(f_out,s?s->count:0);
  write_int(f_out,s?s->n:block_size);
  write_int(f_out,s?s->remainder:0);
  if (s)
    for (i=0;i<s->count;i++) {
      write_int(f_out,s->sums[i].sum1);
      write_buf(f_out,s->sums[i].sum2,csum_length);
    }
}


/*
  generate a stream of signatures/checksums that describe a buffer

  generate approximately one checksum every n bytes
  */
static struct sum_struct *generate_sums(struct map_struct *buf,OFF_T len,int n)
{
  int i;
  struct sum_struct *s;
  int count;
  int block_len = n;
  int remainder = (len%block_len);
  OFF_T offset = 0;

  count = (len+(block_len-1))/block_len;

  s = (struct sum_struct *)malloc(sizeof(*s));
  if (!s) out_of_memory("generate_sums");

  s->count = count;
  s->remainder = remainder;
  s->n = n;
  s->flength = len;

  if (count==0) {
    s->sums = NULL;
    return s;
  }

  if (verbose > 3)
    rprintf(FINFO,"count=%d rem=%d n=%d flength=%d\n",
	    s->count,s->remainder,s->n,(int)s->flength);

  s->sums = (struct sum_buf *)malloc(sizeof(s->sums[0])*s->count);
  if (!s->sums) out_of_memory("generate_sums");
  
  for (i=0;i<count;i++) {
    int n1 = MIN(len,n);
    char *map = map_ptr(buf,offset,n1);

    s->sums[i].sum1 = get_checksum1(map,n1);
    get_checksum2(map,n1,s->sums[i].sum2);

    s->sums[i].offset = offset;
    s->sums[i].len = n1;
    s->sums[i].i = i;

    if (verbose > 3)
      rprintf(FINFO,"chunk[%d] offset=%d len=%d sum1=%08x\n",
	      i,(int)s->sums[i].offset,s->sums[i].len,s->sums[i].sum1);

    len -= n1;
    offset += n1;
  }

  return s;
}


/*
  receive the checksums for a buffer
  */
static struct sum_struct *receive_sums(int f)
{
  struct sum_struct *s;
  int i;
  OFF_T offset = 0;

  s = (struct sum_struct *)malloc(sizeof(*s));
  if (!s) out_of_memory("receive_sums");

  s->count = read_int(f);
  s->n = read_int(f);
  s->remainder = read_int(f);  
  s->sums = NULL;

  if (verbose > 3)
    rprintf(FINFO,"count=%d n=%d rem=%d\n",
	    s->count,s->n,s->remainder);

  if (s->count == 0) 
    return(s);

  s->sums = (struct sum_buf *)malloc(sizeof(s->sums[0])*s->count);
  if (!s->sums) out_of_memory("receive_sums");

  for (i=0;i<s->count;i++) {
    s->sums[i].sum1 = read_int(f);
    read_buf(f,s->sums[i].sum2,csum_length);

    s->sums[i].offset = offset;
    s->sums[i].i = i;

    if (i == s->count-1 && s->remainder != 0) {
      s->sums[i].len = s->remainder;
    } else {
      s->sums[i].len = s->n;
    }
    offset += s->sums[i].len;

    if (verbose > 3)
      rprintf(FINFO,"chunk[%d] len=%d offset=%d sum1=%08x\n",
	      i,s->sums[i].len,(int)s->sums[i].offset,s->sums[i].sum1);
  }

  s->flength = offset;

  return s;
}


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

	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) {
		updated = 1;
		if (set_modtime(fname,file->modtime) != 0) {
			rprintf(FERROR,"failed to set times on %s : %s\n",
				fname,strerror(errno));
			return 0;
		}
	}

	if ((am_root || !am_daemon) &&
	    ((am_root && preserve_uid && st->st_uid != file->uid) || 
	     (preserve_gid && st->st_gid != file->gid))) {
		if (do_lchown(fname,
			      (am_root&&preserve_uid)?file->uid:-1,
			      preserve_gid?file->gid:-1) != 0) {
			if (preserve_uid && st->st_uid != file->uid)
				updated = 1;
			if (verbose>1 || preserve_uid) {
				rprintf(FERROR,"chown %s : %s\n",
					fname,strerror(errno));
				return 0;
			}
		} else {
			updated = 1;
		}
	}

#ifdef HAVE_CHMOD
	if (preserve_perms && !S_ISLNK(st->st_mode) &&
	    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;
}


/* choose whether to skip a particular file */
static int skip_file(char *fname,
		     struct file_struct *file, STRUCT_STAT *st)
{
	if (st->st_size != file->length) {
		return 0;
	}
	
	/* if always checksum is set then we use the checksum instead 
	   of the file time to determine whether to sync */
	if (always_checksum && S_ISREG(st->st_mode)) {
		char sum[MD4_SUM_LENGTH];
		file_checksum(fname,sum,st->st_size);
		return (memcmp(sum,file->sum,csum_length) == 0);
	}

	if (ignore_times) {
		return 0;
	}

	return (st->st_mtime == file->modtime);
}


/* use a larger block size for really big files */
int adapt_block_size(struct file_struct *file, int bsize)
{
	int ret;

	if (bsize != BLOCK_SIZE) return bsize;

	ret = file->length / (10000); /* rough heuristic */
	ret = ret & ~15; /* multiple of 16 */
	if (ret < bsize) ret = bsize;
	if (ret > CHUNK_SIZE/2) ret = CHUNK_SIZE/2;
	return ret;
}

void recv_generator(char *fname,struct file_list *flist,int i,int f_out)
{  
  int fd;
  STRUCT_STAT st;
  struct map_struct *buf;
  struct sum_struct *s;
  int statret;
  struct file_struct *file = flist->files[i];

  if (verbose > 2)
    rprintf(FINFO,"recv_generator(%s,%d)\n",fname,i);

  statret = link_stat(fname,&st);

  if (S_ISDIR(file->mode)) {
    if (dry_run) return;
    if (statret == 0 && !S_ISDIR(st.st_mode)) {
      if (do_unlink(fname) != 0) {
	rprintf(FERROR,"unlink %s : %s\n",fname,strerror(errno));
	return;
      }
      statret = -1;
    }
    if (statret != 0 && do_mkdir(fname,file->mode) != 0 && errno != EEXIST) {
	    if (!(relative_paths && errno==ENOENT && 
		  create_directory_path(fname)==0 && 
		  do_mkdir(fname,file->mode)==0)) {
		    rprintf(FERROR,"mkdir %s : %s (2)\n",
			    fname,strerror(errno));
	    }
    }
    if (set_perms(fname,file,NULL,0) && verbose) 
      rprintf(FINFO,"%s/\n",fname);
    return;
  }

  if (preserve_links && S_ISLNK(file->mode)) {
#if SUPPORT_LINKS
    char lnk[MAXPATHLEN];
    int l;
    if (statret == 0) {
      l = readlink(fname,lnk,MAXPATHLEN-1);
      if (l > 0) {
	lnk[l] = 0;
	if (strcmp(lnk,file->link) == 0) {
	  set_perms(fname,file,&st,1);
	  return;
	}
      }
    }
    delete_file(fname);
    if (do_symlink(file->link,fname) != 0) {
      rprintf(FERROR,"link %s -> %s : %s\n",
	      fname,file->link,strerror(errno));
    } else {
      set_perms(fname,file,NULL,0);
      if (verbose) 
	rprintf(FINFO,"%s -> %s\n",
		fname,file->link);
    }
#endif
    return;
  }

#ifdef HAVE_MKNOD
  if (am_root && preserve_devices && IS_DEVICE(file->mode)) {
    if (statret != 0 || 
	st.st_mode != file->mode ||
	st.st_rdev != file->rdev) {	
      delete_file(fname);
      if (verbose > 2)
	rprintf(FINFO,"mknod(%s,0%o,0x%x)\n",
		fname,(int)file->mode,(int)file->rdev);
      if (do_mknod(fname,file->mode,file->rdev) != 0) {
	rprintf(FERROR,"mknod %s : %s\n",fname,strerror(errno));
      } else {
	set_perms(fname,file,NULL,0);
	if (verbose)
	  rprintf(FINFO,"%s\n",fname);
      }
    } else {
      set_perms(fname,file,&st,1);
    }
    return;
  }
#endif

  if (preserve_hard_links && check_hard_link(file)) {
    if (verbose > 1)
      rprintf(FINFO,"%s is a hard link\n",f_name(file));
    return;
  }

  if (!S_ISREG(file->mode)) {
    rprintf(FINFO,"skipping non-regular file %s\n",fname);
    return;
  }

  if (statret == -1) {
    if (errno == ENOENT) {
      write_int(f_out,i);
      if (!dry_run) send_sums(NULL,f_out);
    } else {
      if (verbose > 1)
	rprintf(FERROR,"recv_generator failed to open %s\n",fname);
    }
    return;
  }

  if (!S_ISREG(st.st_mode)) {
    if (delete_file(fname) != 0) {
      return;
    }

    /* now pretend the file didn't exist */
    write_int(f_out,i);
    if (!dry_run) send_sums(NULL,f_out);    
    return;
  }

  if (update_only && st.st_mtime > file->modtime) {
    if (verbose > 1)
      rprintf(FINFO,"%s is newer\n",fname);
    return;
  }

  if (skip_file(fname, file, &st)) {
    set_perms(fname,file,&st,1);
    return;
  }

  if (dry_run) {
    write_int(f_out,i);
    return;
  }

  if (whole_file) {
    write_int(f_out,i);
    send_sums(NULL,f_out);    
    return;
  }

  /* open the file */  
  fd = open(fname,O_RDONLY);

  if (fd == -1) {
    rprintf(FERROR,"failed to open %s : %s\n",fname,strerror(errno));
    rprintf(FERROR,"skipping %s\n",fname);
    return;
  }

  if (st.st_size > 0) {
    buf = map_file(fd,st.st_size);
  } else {
    buf = NULL;
  }

  if (verbose > 3)
    rprintf(FINFO,"gen mapped %s of size %d\n",fname,(int)st.st_size);

  s = generate_sums(buf,st.st_size,adapt_block_size(file, block_size));

  if (verbose > 2)
    rprintf(FINFO,"sending sums for %d\n",i);

  write_int(f_out,i);
  send_sums(s,f_out);

  close(fd);
  if (buf) unmap_file(buf);

  free_sums(s);
}



static int receive_data(int f_in,struct map_struct *buf,int fd,char *fname)
{
  int i,n,remainder,len,count;
  OFF_T offset = 0;
  OFF_T offset2;
  char *data;
  static char file_sum1[MD4_SUM_LENGTH];
  static char file_sum2[MD4_SUM_LENGTH];
  char *map=NULL;

  count = read_int(f_in);
  n = read_int(f_in);
  remainder = read_int(f_in);

  sum_init();

  for (i=recv_token(f_in,&data); i != 0; i=recv_token(f_in,&data)) {
    if (i > 0) {
      if (verbose > 3)
	rprintf(FINFO,"data recv %d at %d\n",i,(int)offset);

      stats.literal_data += i;
      sum_update(data,i);

      if (fd != -1 && write_file(fd,data,i) != i) {
	rprintf(FERROR,"write failed on %s : %s\n",fname,strerror(errno));
	exit_cleanup(1);
      }
      offset += i;
    } else {
      i = -(i+1);
      offset2 = i*n;
      len = n;
      if (i == count-1 && remainder != 0)
	len = remainder;

      stats.matched_data += len;

      if (verbose > 3)
	rprintf(FINFO,"chunk[%d] of size %d at %d offset=%d\n",
		i,len,(int)offset2,(int)offset);

      map = map_ptr(buf,offset2,len);

      see_token(map, len);
      sum_update(map,len);

      if (fd != -1 && write_file(fd,map,len) != len) {
	rprintf(FERROR,"write failed on %s : %s\n",fname,strerror(errno));
	exit_cleanup(1);
      }
      offset += len;
    }
  }

  if (fd != -1 && offset > 0 && sparse_end(fd) != 0) {
    rprintf(FERROR,"write failed on %s : %s\n",fname,strerror(errno));
    exit_cleanup(1);
  }

  sum_end(file_sum1);

  if (remote_version >= 14) {
    read_buf(f_in,file_sum2,MD4_SUM_LENGTH);
    if (verbose > 2)
      rprintf(FINFO,"got file_sum\n");
    if (fd != -1 && memcmp(file_sum1,file_sum2,MD4_SUM_LENGTH) != 0)
      return 0;
  }
  return 1;
}


static void delete_one(struct file_struct *f)
{
  if (!S_ISDIR(f->mode)) {
    if (do_unlink(f_name(f)) != 0) {
      rprintf(FERROR,"unlink %s : %s\n",f_name(f),strerror(errno));
    } else if (verbose) {
      rprintf(FINFO,"deleting %s\n",f_name(f));
    }
  } else {    
    if (do_rmdir(f_name(f)) != 0) {
      if (errno != ENOTEMPTY && errno != EEXIST)
	rprintf(FERROR,"rmdir %s : %s\n",f_name(f),strerror(errno));
    } else if (verbose) {
      rprintf(FINFO,"deleting directory %s\n",f_name(f));      
    }
  }
}



static struct delete_list {
	dev_t dev;
	ino_t inode;
} *delete_list;
static int dlist_len, dlist_alloc_len;

static void add_delete_entry(struct file_struct *file)
{
	if (dlist_len == dlist_alloc_len) {
		dlist_alloc_len += 1024;
		delete_list = (struct delete_list *)Realloc(delete_list, sizeof(delete_list[0])*dlist_alloc_len);
		if (!delete_list) out_of_memory("add_delete_entry");
	}

	delete_list[dlist_len].dev = file->dev;
	delete_list[dlist_len].inode = file->inode;
	dlist_len++;

	if (verbose > 3)
		rprintf(FINFO,"added %s to delete list\n", f_name(file));
}

/* yuck! This function wouldn't have been necessary if I had the sorting
   algorithm right. Unfortunately fixing the sorting algorithm would introduce
   a backward incompatibility as file list indexes are sent over the link.
*/
static int delete_already_done(struct file_list *flist,int j)
{
	int i;
	STRUCT_STAT st;

	if (link_stat(f_name(flist->files[j]), &st)) return 1;

	for (i=0;i<dlist_len;i++) {
		if (st.st_ino == delete_list[i].inode &&
		    st.st_dev == delete_list[i].dev)
			return 1;
	}

	return 0;
}


/* this deletes any files on the receiving side that are not present
   on the sending side. For version 1.6.4 I have changed the behaviour
   to match more closely what most people seem to expect of this option */
static void delete_files(struct file_list *flist)
{
	struct file_list *local_file_list;
	int i, j;
	char *name;

	if (cvs_exclude)
		add_cvs_excludes();

	if (io_error) {
		rprintf(FINFO,"IO error encountered - skipping file deletion\n");
		return;
	}

	for (j=0;j<flist->count;j++) {
		if (!S_ISDIR(flist->files[j]->mode) || 
		    !(flist->files[j]->flags & FLAG_DELETE)) continue;

		if (remote_version < 19 &&
		    delete_already_done(flist, j)) continue;

		name = strdup(f_name(flist->files[j]));

		if (!(local_file_list = send_file_list(-1,1,&name))) {
			free(name);
			continue;
		}

		if (verbose > 1)
			rprintf(FINFO,"deleting in %s\n", name);

		for (i=local_file_list->count-1;i>=0;i--) {
			if (!local_file_list->files[i]->basename) continue;
			if (remote_version < 19 &&
			    S_ISDIR(local_file_list->files[i]->mode))
				add_delete_entry(local_file_list->files[i]);
			if (-1 == flist_find(flist,local_file_list->files[i])) {
				delete_one(local_file_list->files[i]);
			}    
		}
		flist_free(local_file_list);
		free(name);
	}
}

static char *cleanup_fname;

void exit_cleanup(int code)
{
	io_flush();
	if (cleanup_fname)
		do_unlink(cleanup_fname);
	signal(SIGUSR1, SIG_IGN);
	if (code) {
		kill_all(SIGUSR1);
	}
	exit(code);
}

void sig_int(void)
{
  exit_cleanup(1);
}




static int get_tmpname(char *fnametmp, char *fname)
{
	char *f;

	/* open tmp file */
	if (tmpdir) {
		f = strrchr(fname,'/');
		if (f == NULL) 
			f = fname;
		else 
			f++;
		if (strlen(tmpdir)+strlen(f)+10 > MAXPATHLEN) {
			rprintf(FERROR,"filename too long\n");
			return 0;
		}
		slprintf(fnametmp,MAXPATHLEN-1, "%s/.%s.XXXXXX",tmpdir,f);
		return 1;
	} 

	f = strrchr(fname,'/');

	if (strlen(fname)+9 > MAXPATHLEN) {
		rprintf(FERROR,"filename too long\n");
		return 0;
	}

	if (f) {
		*f = 0;
		slprintf(fnametmp,MAXPATHLEN-1,"%s/.%s.XXXXXX",
			 fname,f+1);
		*f = '/';
	} else {
		slprintf(fnametmp,MAXPATHLEN-1,".%s.XXXXXX",fname);
	}

	return 1;
}

int recv_files(int f_in,struct file_list *flist,char *local_name,int f_gen)
{  
	int fd1,fd2;
	STRUCT_STAT st;
	char *fname;
	char fnametmp[MAXPATHLEN];
	struct map_struct *buf;
	int i;
	struct file_struct *file;
	int phase=0;
	int recv_ok;
	
	if (verbose > 2) {
		rprintf(FINFO,"recv_files(%d) starting\n",flist->count);
	}

	if (recurse && delete_mode && !local_name && flist->count>0) {
		delete_files(flist);
	}

	while (1) {      
		i = read_int(f_in);
		if (i == -1) {
			if (phase==0 && remote_version >= 13) {
				phase++;
				csum_length = SUM_LENGTH;
				if (verbose > 2)
					rprintf(FINFO,"recv_files phase=%d\n",phase);
				write_int(f_gen,-1);
				continue;
			}
			break;
		}

		if (i < 0 || i >= flist->count) {
			rprintf(FERROR,"Invalid file index %d in recv_files (count=%d)\n", 
				i, flist->count);
			exit_cleanup(1);
		}

		file = flist->files[i];
		fname = f_name(file);

		stats.num_transferred_files++;
		stats.total_transferred_size += file->length;

		if (local_name)
			fname = local_name;

		if (dry_run) {
			if (!am_server && verbose)
				printf("%s\n",fname);
			continue;
		}

		if (verbose > 2)
			rprintf(FINFO,"recv_files(%s)\n",fname);

		/* open the file */  
		fd1 = open(fname,O_RDONLY);

		if (fd1 != -1 && do_fstat(fd1,&st) != 0) {
			rprintf(FERROR,"fstat %s : %s\n",fname,strerror(errno));
			receive_data(f_in,NULL,-1,NULL);
			close(fd1);
			continue;
		}

		if (fd1 != -1 && !S_ISREG(st.st_mode)) {
			rprintf(FERROR,"%s : not a regular file (recv_files)\n",fname);
			receive_data(f_in,NULL,-1,NULL);
			close(fd1);
			continue;
		}

		if (fd1 != -1 && st.st_size > 0) {
			buf = map_file(fd1,st.st_size);
			if (verbose > 2)
				rprintf(FINFO,"recv mapped %s of size %d\n",fname,(int)st.st_size);
		} else {
			buf = NULL;
		}

		if (!get_tmpname(fnametmp,fname)) {
			if (buf) unmap_file(buf);
			close(fd1);
			continue;
		}

		if (NULL == do_mktemp(fnametmp)) {
			rprintf(FERROR,"mktemp %s failed\n",fnametmp);
			receive_data(f_in,buf,-1,NULL);
			if (buf) unmap_file(buf);
			close(fd1);
			continue;
		}

		/* we initially set the perms without the
		   setuid/setgid bits to ensure that there is no race
		   condition. They are then correctly updated after
		   the lchown. Thanks to snabb@epipe.fi for pointing
		   this out */
		fd2 = do_open(fnametmp,O_WRONLY|O_CREAT|O_EXCL,
			      file->mode & ACCESSPERMS);

		if (fd2 == -1 && relative_paths && errno == ENOENT && 
		    create_directory_path(fnametmp) == 0) {
			fd2 = do_open(fnametmp,O_WRONLY|O_CREAT|O_EXCL,
				      file->mode & ACCESSPERMS);
		}
		if (fd2 == -1) {
			rprintf(FERROR,"open %s : %s\n",fnametmp,strerror(errno));
			receive_data(f_in,buf,-1,NULL);
			if (buf) unmap_file(buf);
			close(fd1);
			continue;
		}
      
		cleanup_fname = fnametmp;

		if (!am_server && verbose)
			printf("%s\n",fname);
		
		/* recv file data */
		recv_ok = receive_data(f_in,buf,fd2,fname);
		
		if (buf) unmap_file(buf);
		if (fd1 != -1) {
			close(fd1);
		}
		close(fd2);
		
		if (verbose > 2)
			rprintf(FINFO,"renaming %s to %s\n",fnametmp,fname);
		
		if (make_backups) {
			char fnamebak[MAXPATHLEN];
			if (strlen(fname) + strlen(backup_suffix) > (MAXPATHLEN-1)) {
				rprintf(FERROR,"backup filename too long\n");
				continue;
			}
			slprintf(fnamebak,sizeof(fnamebak)-1,"%s%s",fname,backup_suffix);
			if (do_rename(fname,fnamebak) != 0 && errno != ENOENT) {
				rprintf(FERROR,"rename %s %s : %s\n",fname,fnamebak,strerror(errno));
				continue;
			}
		}

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

		cleanup_fname = NULL;

		
		if (!recv_ok) {
			if (csum_length == SUM_LENGTH) {
				rprintf(FERROR,"ERROR: file corruption in %s. File changed during transfer?\n",
					fname);
			} else {
				if (verbose > 1)
					rprintf(FINFO,"redoing %s(%d)\n",fname,i);
				write_int(f_gen,i);
			}
		}
	}

	if (preserve_hard_links)
		do_hard_links(flist);

	/* now we need to fix any directory permissions that were 
	   modified during the transfer */
	for (i = 0; i < flist->count; i++) {
		file = flist->files[i];
		if (!file->basename || !S_ISDIR(file->mode)) continue;
		recv_generator(f_name(file),flist,i,-1);
	}

	if (verbose > 2)
		rprintf(FINFO,"recv_files finished\n");
	
	return 0;
}



void send_files(struct file_list *flist,int f_out,int f_in)
{ 
  int fd;
  struct sum_struct *s;
  struct map_struct *buf;
  STRUCT_STAT st;
  char fname[MAXPATHLEN];  
  int i;
  struct file_struct *file;
  int phase = 0;

  if (verbose > 2)
    rprintf(FINFO,"send_files starting\n");

  setup_readbuffer(f_in);

  while (1) {
	  int offset=0;

	  i = read_int(f_in);
	  if (i == -1) {
		  if (phase==0 && remote_version >= 13) {
			  phase++;
			  csum_length = SUM_LENGTH;
			  write_int(f_out,-1);
			  if (verbose > 2)
				  rprintf(FINFO,"send_files phase=%d\n",phase);
			  continue;
		  }
		  break;
	  }

	  if (i < 0 || i >= flist->count) {
		  rprintf(FERROR,"Invalid file index %d (count=%d)\n", 
			  i, flist->count);
		  exit_cleanup(1);
	  }

	  file = flist->files[i];

	  stats.num_transferred_files++;
	  stats.total_transferred_size += file->length;

	  fname[0] = 0;
	  if (file->basedir) {
		  strlcpy(fname,file->basedir,MAXPATHLEN-1);
		  if (strlen(fname) == MAXPATHLEN-1) {
			  io_error = 1;
			  rprintf(FERROR, "send_files failed on long-named directory %s\n",
				  fname);
			  return;
		  }
		  strlcat(fname,"/",MAXPATHLEN-1);
		  offset = strlen(file->basedir)+1;
	  }
	  strlcat(fname,f_name(file),MAXPATHLEN-strlen(fname));
	  
	  if (verbose > 2) 
		  rprintf(FINFO,"send_files(%d,%s)\n",i,fname);
	  
	  if (dry_run) {	
		  if (!am_server && verbose)
			  printf("%s\n",fname);
		  write_int(f_out,i);
		  continue;
	  }

	  s = receive_sums(f_in);
	  if (!s) {
		  io_error = 1;
		  rprintf(FERROR,"receive_sums failed\n");
		  return;
	  }
	  
	  fd = open(fname,O_RDONLY);
	  if (fd == -1) {
		  io_error = 1;
		  rprintf(FERROR,"send_files failed to open %s: %s\n",
			  fname,strerror(errno));
		  free_sums(s);
		  continue;
	  }
	  
	  /* map the local file */
	  if (do_fstat(fd,&st) != 0) {
		  io_error = 1;
		  rprintf(FERROR,"fstat failed : %s\n",strerror(errno));
		  free_sums(s);
		  close(fd);
		  return;
	  }
	  
	  if (st.st_size > 0) {
		  buf = map_file(fd,st.st_size);
	  } else {
		  buf = NULL;
	  }
	  
	  if (verbose > 2)
		  rprintf(FINFO,"send_files mapped %s of size %d\n",
			  fname,(int)st.st_size);
	  
	  write_int(f_out,i);
	  
	  write_int(f_out,s->count);
	  write_int(f_out,s->n);
	  write_int(f_out,s->remainder);
	  
	  if (verbose > 2)
		  rprintf(FINFO,"calling match_sums %s\n",fname);
	  
	  if (!am_server && verbose)
		  printf("%s\n",fname+offset);
	  
	  match_sums(f_out,s,buf,st.st_size);
	  
	  if (buf) unmap_file(buf);
	  close(fd);
	  
	  free_sums(s);
	  
	  if (verbose > 2)
		  rprintf(FINFO,"sender finished %s\n",fname);
  }

  if (verbose > 2)
	  rprintf(FINFO,"send files finished\n");

  match_report();

  write_int(f_out,-1);
}



void generate_files(int f,struct file_list *flist,char *local_name,int f_recv)
{
  int i;
  int phase=0;

  if (verbose > 2)
    rprintf(FINFO,"generator starting pid=%d count=%d\n",
	    (int)getpid(),flist->count);

  for (i = 0; i < flist->count; i++) {
    struct file_struct *file = flist->files[i];
    mode_t saved_mode = file->mode;
    if (!file->basename) continue;

    /* we need to ensure that any directories we create have writeable
       permissions initially so that we can create the files within
       them. This is then fixed after the files are transferred */
    if (!am_root && S_ISDIR(file->mode)) {
      file->mode |= S_IWUSR; /* user write */
    }

    recv_generator(local_name?local_name:f_name(file),
		   flist,i,f);

    file->mode = saved_mode;
  }

  phase++;
  csum_length = SUM_LENGTH;
  ignore_times=1;

  if (verbose > 2)
    rprintf(FINFO,"generate_files phase=%d\n",phase);

  write_int(f,-1);

  /* we expect to just sit around now, so don't exit on a timeout. If we
     really get a timeout then the other process should exit */
  io_timeout = 0;

  if (remote_version >= 13) {
    /* in newer versions of the protocol the files can cycle through
       the system more than once to catch initial checksum errors */
    for (i=read_int(f_recv); i != -1; i=read_int(f_recv)) {
      struct file_struct *file = flist->files[i];
      recv_generator(local_name?local_name:f_name(file),
		     flist,i,f);    
    }

    phase++;
    if (verbose > 2)
      rprintf(FINFO,"generate_files phase=%d\n",phase);

    write_int(f,-1);
  }
}