Nack LDC protocol versions that we don't support. Avoids a hang on SPARC T3

systems (and possible newer systems as well).

diff --git a/usr.sbin/ldomd/ds.c b/usr.sbin/ldomd/ds.c
index 2bb4ac7..6e19a80 100644 (file)
--- a/usr.sbin/ldomd/ds.c
+++ b/usr.sbin/ldomd/ds.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ds.c,v 1.5 2014/10/15 21:37:27 deraadt Exp $  */
+/*     $OpenBSD: ds.c,v 1.6 2018/07/09 14:46:08 kettenis Exp $ */
 
 /*
  * Copyright (c) 2012 Mark Kettenis
@@ -35,6 +35,7 @@ void  ldc_rx_ctrl_rts(struct ldc_conn *, struct ldc_pkt *);
 void   ldc_rx_ctrl_rdx(struct ldc_conn *, struct ldc_pkt *);
 
 void   ldc_send_ack(struct ldc_conn *);
+void   ldc_send_nack(struct ldc_conn *);
 void   ldc_send_rtr(struct ldc_conn *);
 void   ldc_send_rts(struct ldc_conn *);
 void   ldc_send_rdx(struct ldc_conn *);
@@ -83,8 +84,7 @@ ldc_rx_ctrl_vers(struct ldc_conn *lc, struct ldc_pkt *lp)
                    lvp->minor == LDC_VERSION_MINOR)
                        ldc_send_ack(lc);
                else
-                       /* XXX do nothing for now. */
-                       ;
+                       ldc_send_nack(lc);
                break;
 
        case LDC_ACK:
@@ -313,6 +313,26 @@ ldc_send_ack(struct ldc_conn *lc)
        lc->lc_state = LDC_RCV_VERS;
 }
 
+void
+ldc_send_nack(struct ldc_conn *lc)
+{
+       struct ldc_pkt lp;
+       ssize_t nbytes;
+
+       bzero(&lp, sizeof(lp));
+       lp.type = LDC_CTRL;
+       lp.stype = LDC_NACK;
+       lp.ctrl = LDC_VERS;
+       lp.major = 1;
+       lp.minor = 0;
+
+       nbytes = write(lc->lc_fd, &lp, sizeof(lp));
+       if (nbytes != sizeof(lp))
+               err(1, "write");
+
+       lc->lc_state = 0;
+}
+
 void
 ldc_send_rts(struct ldc_conn *lc)
 {