spice-server: Add the ability to filter agent messages

1 files changed, 85 insertions, 0 deletions

diff --git a/server/agent-msg-filter.c b/server/agent-msg-filter.c
new file mode 100644
index 00000000..3867d11e
--- /dev/null
+++ b/server/agent-msg-filter.c
@@ -0,0 +1,85 @@
+/*
+   Copyright (C) 2011 Red Hat, Inc.
+
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   This library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, see <http://www.gnu.org/licenses/>.
+
+   Red Hat Authors:
+        hdegoede@redhat.com
+*/
+
+#include <string.h>
+#include "red_common.h"
+#include "agent-msg-filter.h"
+
+void agent_msg_filter_init(struct AgentMsgFilter *filter, int copy_paste)
+{
+    memset(filter, 0, sizeof(*filter));
+    filter->copy_paste_enabled = copy_paste;
+}
+
+int agent_msg_filter_process_data(struct AgentMsgFilter *filter,
+                                  uint8_t *data, uint32_t len)
+{
+    struct VDAgentMessage msg_header;
+
+    if (len > VD_AGENT_MAX_DATA_SIZE) {
+        red_printf("invalid agent message: too large");
+        return AGENT_MSG_FILTER_PROTO_ERROR;
+    }
+
+    /* Are we expecting more data from a previous message? */
+    if (filter->msg_data_to_read) {
+data_to_read:
+        if (len > filter->msg_data_to_read) {
+            red_printf("invalid agent message: data exceeds size from header");
+            return AGENT_MSG_FILTER_PROTO_ERROR;
+        }
+        filter->msg_data_to_read -= len;
+        return filter->result;
+    }
+
+    if (len < sizeof(msg_header)) {
+        red_printf("invalid agent message: incomplete header");
+        return AGENT_MSG_FILTER_PROTO_ERROR;
+    }
+    memcpy(&msg_header, data, sizeof(msg_header));
+    len -= sizeof(msg_header);
+
+    if (msg_header.protocol != VD_AGENT_PROTOCOL) {
+        red_printf("invalid agent protocol: %u", msg_header.protocol);
+        return AGENT_MSG_FILTER_PROTO_ERROR;
+    }
+
+    switch (msg_header.type) {
+    case VD_AGENT_CLIPBOARD:
+    case VD_AGENT_CLIPBOARD_GRAB:
+    case VD_AGENT_CLIPBOARD_REQUEST:
+    case VD_AGENT_CLIPBOARD_RELEASE:
+        if (filter->copy_paste_enabled) {
+            filter->result = AGENT_MSG_FILTER_OK;
+        } else {
+            filter->result = AGENT_MSG_FILTER_DISCARD;
+        }
+        break;
+    default:
+        filter->result = AGENT_MSG_FILTER_OK;
+    }
+
+    filter->msg_data_to_read = msg_header.size;
+    if (filter->msg_data_to_read) {
+        goto data_to_read;
+    }
+
+    return filter->result;
+}