X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/3ec4dd9781ed23be4a2b939fa5bfded619a1a8fb..2b284ee33d97c4414c49c45720a3566a58a93a18:/compat.c

diff --git a/compat.c b/compat.c
index 237e40c0..d1c367a7 100644
--- a/compat.c
+++ b/compat.c
@@ -17,13 +17,17 @@
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
 
-/* compatability routines for older rsync protocol versions */
+/**
+ * @file compat.c
+ *
+ * Compatibility routines for older rsync protocol versions.
+ **/
 
 #include "rsync.h"
 
-extern int am_server;
+int remote_protocol = 0;
 
-extern int csum_length;
+extern int am_server;
 
 extern int preserve_links;
 extern int preserve_perms;
@@ -34,36 +38,56 @@ extern int preserve_times;
 extern int always_checksum;
 extern int checksum_seed;
 
+extern int protocol_version;
+extern int verbose;
 
-extern int remote_version;
+extern int read_batch;
+extern int write_batch;
 
 void setup_protocol(int f_out,int f_in)
 {
-  if (am_server) {
-    remote_version = read_int(f_in);
-    write_int(f_out,PROTOCOL_VERSION);
-    write_flush(f_out);
-  } else {
-    write_int(f_out,PROTOCOL_VERSION);
-    write_flush(f_out);
-    remote_version = read_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 (remote_version < MIN_PROTOCOL_VERSION ||
-      remote_version > MAX_PROTOCOL_VERSION) {
-    fprintf(FERROR,"protocol version mismatch - is your shell clean?\n");
-    exit_cleanup(1);
-  }	
+	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 (remote_version >= 12) {
-    if (am_server) {
-      checksum_seed = time(NULL);
-      write_int(f_out,checksum_seed);
-    } else {
-      checksum_seed = read_int(f_in);
-    }
-  }
-
-  checksum_init();
+	if (am_server) {
+		if (!checksum_seed)
+			checksum_seed = time(NULL);
+		write_int(f_out, checksum_seed);
+	} else {
+		checksum_seed = read_int(f_in);
+	}
 }
-