Be a bit more helpful when someone tries something silly.

diff --git a/nbd-client.c b/nbd-client.c
index 1445621..83a68f8 100644 (file)
--- a/nbd-client.c
+++ b/nbd-client.c
@@ -278,8 +278,11 @@ void negotiate(int sock, u64 *rsize64, u32 *flags, char* name, uint32_t needed_f
                if (write(sock, name, strlen(name)) < 0)
                        err("Failed/2.4: %m");
        } else {
-               if (magic != cliserv_magic)
-                       err("Not enough cliserv_magic");
+               if (magic != cliserv_magic) {
+                       if(magic != opts_magic)
+                               err("Not enough cliserv_magic");
+                       else
+                               err("It looks like you're trying to connect to a newstyle server with the oldstyle protocol. Try the -N option.");
                printf(".");
        }