[PATCH] ssh-protocol version, command types, response code

This patch makes an incompatible change to the protocol used by
rpull/rpush which will let it be extended in the future without
incompatible changes.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

rpull.c

@@ -6,16 +6,39 @@
 static int fd_in;
 static int fd_out;
 
+static unsigned char remote_version = 0;
+static unsigned char local_version = 1;
+
 int fetch(unsigned char *sha1)
 {
 	int ret;
+	signed char remote;
+	char type = 'o';
+	if (has_sha1_file(sha1))
+		return 0;
+	write(fd_out, &type, 1);
 	write(fd_out, sha1, 20);
+	if (read(fd_in, &remote, 1) < 1)
+		return -1;
+	if (remote < 0)
+		return remote;
 	ret = write_sha1_from_fd(sha1, fd_in);
 	if (!ret)
 		pull_say("got %s\n", sha1_to_hex(sha1));
 	return ret;
 }
 
+int get_version(void)
+{
+	char type = 'v';
+	write(fd_out, &type, 1);
+	write(fd_out, &local_version, 1);
+	if (read(fd_in, &remote_version, 1) < 1) {
+		return error("Couldn't read version from remote end");
+	}
+	return 0;
+}
+
 int main(int argc, char **argv)
 {
 	char *commit_id;
@@ -48,6 +71,9 @@ int main(int argc, char **argv)
 	if (setup_connection(&fd_in, &fd_out, "git-rpush", url, arg, argv + 1))
 		return 1;
 
+	if (get_version())
+		return 1;
+
 	if (pull(commit_id))
 		return 1;
 

rpush.c

@@ -3,33 +3,43 @@
 #include <sys/socket.h>
 #include <errno.h>
 
-static void service(int fd_in, int fd_out) {
+unsigned char local_version = 1;
+unsigned char remote_version = 0;
+
+int serve_object(int fd_in, int fd_out) {
 	ssize_t size;
-	int posn;
-	char unsigned sha1[20];
+	int posn = 0;
+	char sha1[20];
 	unsigned long objsize;
 	void *buf;
-	do {
-		posn = 0;
+	signed char remote;
 	do {
 		size = read(fd_in, sha1 + posn, 20 - posn);
 		if (size < 0) {
 			perror("git-rpush: read ");
-				return;
+			return -1;
 		}
 		if (!size)
-				return;
+			return -1;
 		posn += size;
 	} while (posn < 20);
 	
 	/* fprintf(stderr, "Serving %s\n", sha1_to_hex(sha1)); */
+	remote = 0;
 	
 	buf = map_sha1_file(sha1, &objsize);
+	
 	if (!buf) {
 		fprintf(stderr, "git-rpush: could not find %s\n", 
 			sha1_to_hex(sha1));
-			return;
+		remote = -1;
 	}
+	
+	write(fd_out, &remote, 1);
+	
+	if (remote < 0)
+		return 0;
+	
 	posn = 0;
 	do {
 		size = write(fd_out, buf + posn, objsize - posn);
@@ -39,10 +49,35 @@ static void service(int fd_in, int fd_out) {
 			} else {
 				perror("git-rpush: write ");
 			}
-				return;
+			return -1;
 		}
 		posn += size;
 	} while (posn < objsize);
+	return 0;
+}
+
+int serve_version(int fd_in, int fd_out)
+{
+	if (read(fd_in, &remote_version, 1) < 1)
+		return -1;
+	write(fd_out, &local_version, 1);
+	return 0;
+}
+
+void service(int fd_in, int fd_out) {
+	char type;
+	int retval;
+	do {
+		retval = read(fd_in, &type, 1);
+		if (retval < 1) {
+			if (retval < 0)
+				perror("rpush: read ");
+			return;
+		}
+		if (type == 'v' && serve_version(fd_in, fd_out))
+			return;
+		if (type == 'o' && serve_object(fd_in, fd_out))
+			return;
 	} while (1);
 }