From: Andre Noll <maan@systemlinux.org>
Date: Mon, 23 Jul 2012 17:07:07 +0000 (+0200)
Subject: Reject non-sideband connections.
X-Git-Tag: v0.5.0~10^2~5
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=36ba180901dd97003208ee6c51b0795cf351cb03

Reject non-sideband connections.

This makes the client abort the connection if the server does not
support sideband. Conversely, the server closes the socket if the
client did not request a sideband connection.

This breaks compatibility with earlier versions of para_server and
para_client but allows to clean up the code considerably.
---

diff --git a/client_common.c b/client_common.c
index 7bdb4738..a3a471ae 100644
--- a/client_common.c
+++ b/client_common.c
@@ -345,6 +345,11 @@ static void client_post_select(struct sched *s, struct task *t)
 		if (ret < 0 || n == 0)
 			goto out;
 		ct->features = parse_features(buf);
+		if (!has_feature("sideband", ct)) {
+			PARA_ERROR_LOG("server has no sideband support\n");
+			ret = -E_INCOMPAT_FEAT;
+			goto out;
+		}
 		ct->status = CL_RECEIVED_WELCOME;
 		return;
 	case CL_RECEIVED_WELCOME: /* send auth command */
diff --git a/command.c b/command.c
index 39470fa9..9b279f7d 100644
--- a/command.c
+++ b/command.c
@@ -904,6 +904,11 @@ static int parse_auth_request(char *buf, int len, struct user **u,
 			}
 		}
 	}
+	if (*use_sideband == false) { /* sideband is mandatory */
+		PARA_ERROR_LOG("client did not request sideband\n");
+		ret = -E_BAD_FEATURE;
+		goto out;
+	}
 	PARA_DEBUG_LOG("received auth request for user %s (sideband = %s)\n",
 		username, *use_sideband? "true" : "false");
 	*u = lookup_user(username);
diff --git a/error.h b/error.h
index ca172cb4..844c0045 100644
--- a/error.h
+++ b/error.h
@@ -289,6 +289,7 @@ extern const char **para_errlist[];
 	PARA_ERROR(SERVER_EOF, "connection closed by para_server"), \
 	PARA_ERROR(SERVER_CMD_SUCCESS, "command terminated successfully"), \
 	PARA_ERROR(SERVER_CMD_FAILURE, "command failed"), \
+	PARA_ERROR(INCOMPAT_FEAT, "client/server incompatibility"), \
 
 
 #define SCHED_ERRORS \
@@ -463,7 +464,7 @@ extern const char **para_errlist[];
 	PARA_ERROR(SENDER_CMD, "command not supported by this sender"), \
 	PARA_ERROR(SERVER_CRASH, "para_server crashed -- can not live without it"), \
 	PARA_ERROR(BAD_USER, "auth request for invalid user"), \
-	PARA_ERROR(BAD_FEATURE, "request for unknown or invalid feature"), \
+	PARA_ERROR(BAD_FEATURE, "invalid feature request"), \
 	PARA_ERROR(BAD_AUTH, "authentication failure"), \