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[rsync/rsync.git] / compat.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.
*/

/**
 * @file compat.c
 *
 * Compatibility routines for older rsync protocol versions.
 **/

#include "rsync.h"

int remote_protocol = 0;

extern int am_server;

extern int checksum_seed;

extern int protocol_version;
extern int verbose;

void setup_protocol(int f_out,int f_in)
{
	if (remote_protocol == 0) {
		if (am_server) {
			remote_protocol = read_int(f_in);
			write_int(f_out, protocol_version);
		} else {
			write_int(f_out, protocol_version);
			remote_protocol = read_int(f_in);
		}
		if (protocol_version > remote_protocol)
			protocol_version = remote_protocol;
	}

	if (verbose > 3) {
		rprintf(FINFO, "(%s) Protocol versions: remote=%d, negotiated=%d\n",
			am_server? "Server" : "Client", remote_protocol, protocol_version);
	}
	if (remote_protocol < MIN_PROTOCOL_VERSION
	 || remote_protocol > MAX_PROTOCOL_VERSION) {
		rprintf(FERROR,"protocol version mismatch - is your shell clean?\n");
		rprintf(FERROR,"(see the rsync man page for an explanation)\n");
		exit_cleanup(RERR_PROTOCOL);
	}
	if (remote_protocol < OLD_PROTOCOL_VERSION) {
		rprintf(FINFO,"%s is very old version of rsync, upgrade recommended.\n",
			am_server? "Client" : "Server");
	}
	if (protocol_version < MIN_PROTOCOL_VERSION) {
		rprintf(FERROR, "--protocol must be at least %d on the %s.\n",
			MIN_PROTOCOL_VERSION, am_server? "Server" : "Client");
		exit_cleanup(RERR_PROTOCOL);
	}
	if (protocol_version > PROTOCOL_VERSION) {
		rprintf(FERROR, "--protocol must be no more than %d on the %s.\n",
			PROTOCOL_VERSION, am_server? "Server" : "Client");
		exit_cleanup(RERR_PROTOCOL);
	}

	if (am_server) {
		if (!checksum_seed)
			checksum_seed = time(NULL);
		write_int(f_out, checksum_seed);
	} else {
		checksum_seed = read_int(f_in);
	}
}