[Spice-commits] Branch '0.12' - server/reds.c

[Frediano Ziglio]

 server/reds.c |   28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

New commits:
commit bb79d369e8d0796a5d4f5e578171a1ef807d2ab6
Author: Frediano Ziglio <fziglio at redhat.com>
Date:   Thu Jan 26 15:53:18 2017 +0000

    reds: Check link header magic without waiting for the whole header
    
    This allows the connection to early fail in case initial bytes
    are not correct.
    This allows for instance VNC client to graceful fail connecting
    to a spice-server. This happens easily as the two protocols
    share the same range of ports.
    
    This resolves rhbz#1416692.
    
    Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
    Acked-by: Christophe Fergeau <cfergeau at redhat.com>

diff --git a/server/reds.c b/server/reds.c
index 9150454..f439a36 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -2192,12 +2192,6 @@ static void reds_handle_read_header_done(void *opaque)
     header->minor_version = GUINT32_FROM_LE(header->minor_version);
     header->size = GUINT32_FROM_LE(header->size);
 
-    if (header->magic != SPICE_MAGIC) {
-        reds_send_link_error(link, SPICE_LINK_ERR_INVALID_MAGIC);
-        reds_link_free(link);
-        return;
-    }
-
     if (header->major_version != SPICE_VERSION_MAJOR) {
         if (header->major_version > 0) {
             reds_send_link_error(link, SPICE_LINK_ERR_VERSION_MISMATCH);
@@ -2227,13 +2221,31 @@ static void reds_handle_read_header_done(void *opaque)
                            link);
 }
 
+static void reds_handle_read_magic_done(void *opaque)
+{
+    RedLinkInfo *link = (RedLinkInfo *)opaque;
+    const SpiceLinkHeader *header = &link->link_header;
+
+    if (header->magic != SPICE_MAGIC) {
+        reds_send_link_error(link, SPICE_LINK_ERR_INVALID_MAGIC);
+        reds_link_free(link);
+        return;
+    }
+
+    reds_stream_async_read(link->stream,
+                           ((uint8_t *)&link->link_header) + sizeof(header->magic),
+                           sizeof(SpiceLinkHeader) - sizeof(header->magic),
+                           reds_handle_read_header_done,
+                           link);
+}
+
 static void reds_handle_new_link(RedLinkInfo *link)
 {
     reds_stream_set_async_error_handler(link->stream, reds_handle_link_error);
     reds_stream_async_read(link->stream,
                            (uint8_t *)&link->link_header,
-                           sizeof(SpiceLinkHeader),
-                           reds_handle_read_header_done,
+                           sizeof(link->link_header.magic),
+                           reds_handle_read_magic_done,
                            link);
 }