connection: return error on buffer-overflow during read

wl_connection_read() assumes that the caller dispatched all messages
before calling it. wl_buffer_put_iov() does only provide enough room so we
fill the buffer. So the only case when the buffer overflows, is when a
previous read filled up the buffer but we couldn't parse a single message
from it. In this case, the client sent a message bigger than our buffer
and we should return an error and close the connection.

krh: Edited from Davids original patch to just check that the buffer
 isn't full before we try reading into it.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

diff --git a/src/connection.c b/src/connection.c
index b00491e..fdc9309 100644 (file)
--- a/src/connection.c
+++ b/src/connection.c
@@ -314,6 +314,11 @@ wl_connection_read(struct wl_connection *connection)
        char cmsg[CLEN];
        int len, count, ret;
 
+       if (wl_buffer_size(&connection->in) >= sizeof(connection->in.data)) {
+               errno = EOVERFLOW;
+               return -1;
+       }
+
        wl_buffer_put_iov(&connection->in, iov, &count);
 
        msg.msg_name = NULL;