nd6: Remove DRAFT_IETF_6MAN_IPV6ONLY_FLAG and EXPERIMENTAL options

The draft-ietf-6man-ipv6only-flag has been obsoleted by RFC 8925.
Remove the EXPERIMENTAL compile option from the kernel and remove
DRAFT_IETF_6MAN_IPV6ONLY_FLAG from userland.
This compile option was not enabled by default.
Also regenerate src.conf.5.

Reviewed by: bz
Differential Revision: https://reviews.freebsd.org/D56228

usr.sbin/ndp/Makefile

@@ -23,11 +23,6 @@ LIBADD=	xo
 CFLAGS+= -I. -I${.CURDIR}
 CFLAGS+= -D_U_=""
 
-.if ${MK_EXPERIMENTAL} != "no"
-CFLAGS+=	-DEXPERIMENTAL
-CFLAGS+=	-DDRAFT_IETF_6MAN_IPV6ONLY_FLAG
-.endif
-
 .if ${MK_NETLINK_SUPPORT} != "no"
 SRCS+=	ndp_netlink.c
 .else

usr.sbin/ndp/ndp.c

@@ -1225,12 +1225,7 @@ rtrlist(void)
 			*pflags++ = 'O';
 			xo_emit("{el:%s}", "other");
 		}
-#ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG
-		if (p->flags & ND_RA_FLAG_IPV6_ONLY) {
-			*pflags++ = 'S';
-			xo_emit("{el:%s}", "ipv6only");
-		}
-#endif
+
 		xo_close_list("flags_pretty");
 		xo_emit(", flags={:flags/%s}", rflags);
 

usr.sbin/rtadvd/Makefile

@@ -20,11 +20,6 @@ MAN=	rtadvd.conf.5 rtadvd.8
 SRCS=	rtadvd.c rrenum.c advcap.c if.c config.c timer.c timer_subr.c	\
 	control.c control_server.c
 
-.if ${MK_EXPERIMENTAL} != "no"
-CFLAGS+=	-DEXPERIMENTAL
-CFLAGS+=	-DDRAFT_IETF_6MAN_IPV6ONLY_FLAG
-.endif
-
 LIBADD=	util
 
 WARNS?=	1

usr.sbin/rtadvd/config.c

@@ -442,10 +442,6 @@ getconfig(struct ifinfo *ifi)
 			}
 			val |= ND_RA_FLAG_RTPREF_LOW;
 		}
-#ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG
-		if (strchr(flagstr, 'S'))
-			val |= ND_RA_FLAG_IPV6_ONLY;
-#endif
 	} else
 		MAYHAVE(val, "raflags", 0);
 
@@ -461,9 +457,6 @@ getconfig(struct ifinfo *ifi)
 		    __func__, rai->rai_rtpref, ifi->ifi_ifname);
 		goto getconfig_free_rai;
 	}
-#ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG
-	rai->rai_ipv6onlyflg = val & ND_RA_FLAG_IPV6_ONLY;
-#endif
 
 	MAYHAVE(val, "rltime", rai->rai_maxinterval * 3);
 	if ((uint16_t)val && ((uint16_t)val < rai->rai_maxinterval ||
@@ -1485,10 +1478,6 @@ make_packet(struct rainfo *rai)
 		rai->rai_managedflg ? ND_RA_FLAG_MANAGED : 0;
 	ra->nd_ra_flags_reserved |=
 		rai->rai_otherflg ? ND_RA_FLAG_OTHER : 0;
-#ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG
-	ra->nd_ra_flags_reserved |=
-		rai->rai_ipv6onlyflg ? ND_RA_FLAG_IPV6_ONLY : 0;
-#endif
 	ra->nd_ra_router_lifetime = htons(rai->rai_lifetime);
 	ra->nd_ra_reachable = htonl(rai->rai_reachabletime);
 	ra->nd_ra_retransmit = htonl(rai->rai_retranstimer);

usr.sbin/rtadvd/rtadvd.c

@@ -1148,19 +1148,6 @@ ra_input(int len, struct nd_router_advert *nra,
 			sizeof(ntopbuf)), on_off[rai->rai_otherflg]);
 		inconsistent++;
 	}
-#ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG
-	/* S "IPv6-Only" (Six, Silence-IPv4) flag */
-	if ((nra->nd_ra_flags_reserved & ND_RA_FLAG_IPV6_ONLY) !=
-	    rai->rai_ipv6onlyflg) {
-		syslog(LOG_NOTICE,
-		    "S flag inconsistent on %s:"
-		    " %s from %s, %s from us",
-		    ifi->ifi_ifname, on_off[!rai->rai_ipv6onlyflg],
-		    inet_ntop(AF_INET6, &from->sin6_addr, ntopbuf,
-			sizeof(ntopbuf)), on_off[rai->rai_ipv6onlyflg]);
-		inconsistent++;
-	}
-#endif
 	/* Reachable Time */
 	reachabletime = ntohl(nra->nd_ra_reachable);
 	if (reachabletime && rai->rai_reachabletime &&

usr.sbin/rtadvd/rtadvd.h

@@ -204,9 +204,6 @@ struct	rainfo {
 	uint16_t	rai_mininterval;	/* MinRtrAdvInterval */
 	int 	rai_managedflg;		/* AdvManagedFlag */
 	int	rai_otherflg;		/* AdvOtherConfigFlag */
-#ifdef DRAFT_IETF_6MAN_IPV6ONLY_FLAG
-	int	rai_ipv6onlyflg;	/* AdvIPv6OnlyFlag */
-#endif
 
 	int	rai_rtpref;		/* router preference */
 	uint32_t	rai_linkmtu;		/* AdvLinkMTU */