rtadvd/rrenum.c:179

[Matthew Luckie]

When rtadvd is compiled on 7.0, the following warning is emitted:

/usr/src/usr.sbin/rtadvd/rrenum.c:179: warning: overflow in implicit
constant conversion

I have not determined if the code works correct or not, but I wonder
if it does.  the line in question is this:

   struct irr_raflagmask {
   	  u_char onlink : 1;
	  u_char autonomous : 1;
	  u_char reserved : 6;
   } irr_raflagmask;

irr->irr_raf_mask_onlink = (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);

rpu_ramask is unsigned char, the constant is 0x80, and
irr_raf_mask_onlink is a single bit value.  This troubles me, and the
compiler.

I'm only raising this for consideration; if it can be determined that
the code works correctly, maybe a commit can be made to silence the
warnings.

--- rrenum.c.orig   2004-03-10 21:46:39.000000000 +1300
+++ rrenum.c    2008-05-19 19:39:52.000000000 +1200
@@ -176,9 +176,9 @@ do_use_prefix(int len, struct rr_pco_mat
                irr->irr_u_uselen = rpu->rpu_uselen;
                irr->irr_u_keeplen = rpu->rpu_keeplen;
                irr->irr_raf_mask_onlink =
-                       (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK);
+                       (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_ONLINK) == 0 ? 0 : 1;
                irr->irr_raf_mask_auto =
-                       (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO);
+                       (rpu->rpu_ramask & ICMP6_RR_PCOUSE_RAFLAGS_AUTO) == 0 ? 0 : 1;
                irr->irr_vltime = ntohl(rpu->rpu_vltime);
                irr->irr_pltime = ntohl(rpu->rpu_pltime);
                irr->irr_raf_onlink =