[IPV6]: Reporting of prefix routes via rtnetlink.

include/linux/ipv6_route.h

@@ -16,6 +16,7 @@
 #define RTF_DEFAULT	0x00010000	/* default - learned via ND	*/
 #define RTF_ALLONLINK	0x00020000	/* fallback, no routers on link	*/
 #define RTF_ADDRCONF	0x00040000	/* addrconf route - RA		*/
+#define RTF_PREFIX_RT	0x00080000	/* A prefix only route - RA	*/
 
 #define RTF_NONEXTHOP	0x00200000	/* route with no nexthop	*/
 #define RTF_EXPIRES	0x00400000

include/linux/rtnetlink.h

@@ -168,6 +168,7 @@ enum rt_scope_t
 #define RTM_F_NOTIFY		0x100	/* Notify user of route change	*/
 #define RTM_F_CLONED		0x200	/* This route is cloned		*/
 #define RTM_F_EQUALIZE		0x400	/* Multipath equalizer: NI	*/
+#define RTM_F_PREFIX		0x800	/* Prefix addresses		*/
 
 /* Reserved table identifiers */
 

net/ipv6/addrconf.c

@@ -130,7 +130,7 @@ static spinlock_t addrconf_verify_lock = SPIN_LOCK_UNLOCKED;
 
 static int addrconf_ifdown(struct net_device *dev, int how);
 
-static void addrconf_dad_start(struct inet6_ifaddr *ifp);
+static void addrconf_dad_start(struct inet6_ifaddr *ifp, int flags);
 static void addrconf_dad_timer(unsigned long data);
 static void addrconf_dad_completed(struct inet6_ifaddr *ifp);
 static void addrconf_rs_timer(unsigned long data);
@@ -710,7 +710,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *i
 	ift->prefered_lft = tmp_prefered_lft;
 	ift->tstamp = ifp->tstamp;
 	spin_unlock_bh(&ift->lock);
-	addrconf_dad_start(ift);
+	addrconf_dad_start(ift, 0);
 	in6_ifa_put(ift);
 	in6_dev_put(idev);
 out:
@@ -1247,7 +1247,7 @@ static void addrconf_add_mroute(struct net_device *dev)
 	rtmsg.rtmsg_dst_len = 8;
 	rtmsg.rtmsg_metric = IP6_RT_PRIO_ADDRCONF;
 	rtmsg.rtmsg_ifindex = dev->ifindex;
-	rtmsg.rtmsg_flags = RTF_UP|RTF_ADDRCONF;
+	rtmsg.rtmsg_flags = RTF_UP;
 	rtmsg.rtmsg_type = RTMSG_NEWROUTE;
 	ip6_route_add(&rtmsg, NULL, NULL);
 }
@@ -1274,7 +1274,7 @@ static void addrconf_add_lroute(struct net_device *dev)
 	struct in6_addr addr;
 
 	ipv6_addr_set(&addr,  htonl(0xFE800000), 0, 0, 0);
-	addrconf_prefix_route(&addr, 64, dev, 0, RTF_ADDRCONF);
+	addrconf_prefix_route(&addr, 64, dev, 0, 0);
 }
 
 static struct inet6_dev *addrconf_add_dev(struct net_device *dev)
@@ -1367,7 +1367,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
 			}
 		} else if (valid_lft) {
 			addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len,
-					      dev, rt_expires, RTF_ADDRCONF|RTF_EXPIRES);
+					      dev, rt_expires, RTF_ADDRCONF|RTF_EXPIRES|RTF_PREFIX_RT);
 		}
 		if (rt)
 			dst_release(&rt->u.dst);
@@ -1413,7 +1413,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len)
 			}
 
 			update_lft = create = 1;
-			addrconf_dad_start(ifp);
+			addrconf_dad_start(ifp, RTF_ADDRCONF|RTF_PREFIX_RT);
 		}
 
 		if (ifp) {
@@ -1586,7 +1586,7 @@ static int inet6_addr_add(int ifindex, struct in6_addr *pfx, int plen)
 
 	ifp = ipv6_add_addr(idev, pfx, plen, scope, IFA_F_PERMANENT);
 	if (!IS_ERR(ifp)) {
-		addrconf_dad_start(ifp);
+		addrconf_dad_start(ifp, 0);
 		in6_ifa_put(ifp);
 		return 0;
 	}
@@ -1761,7 +1761,7 @@ static void addrconf_add_linklocal(struct inet6_dev *idev, struct in6_addr *addr
 
 	ifp = ipv6_add_addr(idev, addr, 64, IFA_LINK, IFA_F_PERMANENT);
 	if (!IS_ERR(ifp)) {
-		addrconf_dad_start(ifp);
+		addrconf_dad_start(ifp, 0);
 		in6_ifa_put(ifp);
 	}
 }
@@ -2021,8 +2021,7 @@ static void addrconf_rs_timer(unsigned long data)
 		memset(&rtmsg, 0, sizeof(struct in6_rtmsg));
 		rtmsg.rtmsg_type = RTMSG_NEWROUTE;
 		rtmsg.rtmsg_metric = IP6_RT_PRIO_ADDRCONF;
-		rtmsg.rtmsg_flags = (RTF_ALLONLINK | RTF_ADDRCONF | 
-				     RTF_DEFAULT | RTF_UP);
+		rtmsg.rtmsg_flags = (RTF_ALLONLINK | RTF_DEFAULT | RTF_UP);
 
 		rtmsg.rtmsg_ifindex = ifp->idev->dev->ifindex;
 
@@ -2036,7 +2035,7 @@ static void addrconf_rs_timer(unsigned long data)
 /*
  *	Duplicate Address Detection
  */
-static void addrconf_dad_start(struct inet6_ifaddr *ifp)
+static void addrconf_dad_start(struct inet6_ifaddr *ifp, int flags)
 {
 	struct net_device *dev;
 	unsigned long rand_num;
@@ -2046,7 +2045,8 @@ static void addrconf_dad_start(struct inet6_ifaddr *ifp)
 	addrconf_join_solict(dev, &ifp->addr);
 
 	if (ifp->prefix_len != 128 && (ifp->flags&IFA_F_PERMANENT))
-		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, dev, 0, RTF_ADDRCONF);
+		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, dev, 0,
+					flags);
 
 	net_srandom(ifp->addr.s6_addr32[3]);
 	rand_num = net_random() % (ifp->idev->cnf.rtr_solicit_delay ? : 1);

net/ipv6/route.c

@@ -1459,13 +1459,20 @@ static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
 			 struct in6_addr *src,
 			 int iif,
 			 int type, u32 pid, u32 seq,
-			 struct nlmsghdr *in_nlh)
+			 struct nlmsghdr *in_nlh, int prefix)
 {
 	struct rtmsg *rtm;
 	struct nlmsghdr  *nlh;
 	unsigned char	 *b = skb->tail;
 	struct rta_cacheinfo ci;
 
+	if (prefix) {	/* user wants prefix routes only */
+		if (!(rt->rt6i_flags & RTF_PREFIX_RT)) {
+			/* success since this is not a prefix route */
+			return 1;
+		}
+	}
+
 	if (!pid && in_nlh) {
 		pid = in_nlh->nlmsg_pid;
 	}
@@ -1546,10 +1553,17 @@ static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
 static int rt6_dump_route(struct rt6_info *rt, void *p_arg)
 {
 	struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
+	struct rtmsg *rtm;
+	int prefix;
+
+	rtm = NLMSG_DATA(arg->cb->nlh);
+	if (rtm)
+		prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0;
+	else prefix = 0;
 
 	return rt6_fill_node(arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
 		     NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq,
-		     NULL);
+		     NULL, prefix);
 }
 
 static int fib6_dump_node(struct fib6_walker_t *w)
@@ -1697,7 +1711,7 @@ int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg)
 			    &fl.fl6_dst, &fl.fl6_src,
 			    iif,
 			    RTM_NEWROUTE, NETLINK_CB(in_skb).pid,
-			    nlh->nlmsg_seq, nlh);
+			    nlh->nlmsg_seq, nlh, 0);
 	if (err < 0) {
 		err = -EMSGSIZE;
 		goto out_free;
@@ -1723,7 +1737,7 @@ void inet6_rt_notify(int event, struct rt6_info *rt, struct nlmsghdr *nlh)
 		netlink_set_err(rtnl, 0, RTMGRP_IPV6_ROUTE, ENOBUFS);
 		return;
 	}
-	if (rt6_fill_node(skb, rt, NULL, NULL, 0, event, 0, 0, nlh) < 0) {
+	if (rt6_fill_node(skb, rt, NULL, NULL, 0, event, 0, 0, nlh, 0) < 0) {
 		kfree_skb(skb);
 		netlink_set_err(rtnl, 0, RTMGRP_IPV6_ROUTE, EINVAL);
 		return;