[IPV6]: V6 route events reported with wrong netlink PID and seq number

Essentially netlink at the moment always reports a pid and sequence of 0
always for v6 route activities. 
To understand the repurcassions of this look at:
http://lists.quagga.net/pipermail/quagga-dev/2005-June/003507.html

While fixing this, i took the liberty to resolve the outstanding issue
of IPV6 routes inserted via ioctls to have the correct pids as well.

This patch tries to behave as close as possible to the v4 routes i.e
maintains whatever PID the socket issuing the command owns as opposed to
the process. That made the patch a little bulky.

I have tested against both netlink derived utility to add/del routes as
well as ioctl derived one. The Quagga folks have tested against quagga.
This fixes the problem and so far hasnt been detected to introduce any
new issues.

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 41 insertions, 37 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 1f5b226..878789b 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -384,12 +384,13 @@ struct rt6_info *rt6_lookup(struct in6_addr *daddr, struct in6_addr *saddr,
    be destroyed.
  */
 
-int ip6_ins_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr)
+int ip6_ins_rt(struct rt6_info *rt, struct nlmsghdr *nlh,
+		void *_rtattr, struct netlink_skb_parms *req)
 {
 	int err;
 
 	write_lock_bh(&rt6_lock);
-	err = fib6_add(&ip6_routing_table, rt, nlh, _rtattr);
+	err = fib6_add(&ip6_routing_table, rt, nlh, _rtattr, req);
 	write_unlock_bh(&rt6_lock);
 
 	return err;
@@ -400,7 +401,7 @@ int ip6_ins_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr)
  */
 
 static struct rt6_info *rt6_cow(struct rt6_info *ort, struct in6_addr *daddr,
-				struct in6_addr *saddr)
+				struct in6_addr *saddr, struct netlink_skb_parms *req)
 {
 	int err;
 	struct rt6_info *rt;
@@ -432,7 +433,7 @@ static struct rt6_info *rt6_cow(struct rt6_info *ort, struct in6_addr *daddr,
 
 		dst_hold(&rt->u.dst);
 
-		err = ip6_ins_rt(rt, NULL, NULL);
+		err = ip6_ins_rt(rt, NULL, NULL, req);
 		if (err == 0)
 			return rt;
 
@@ -491,7 +492,8 @@ restart:
 		read_unlock_bh(&rt6_lock);
 
 		nrt = rt6_cow(rt, &skb->nh.ipv6h->daddr,
-			      &skb->nh.ipv6h->saddr);
+			      &skb->nh.ipv6h->saddr,
+			      &NETLINK_CB(skb));
 
 		dst_release(&rt->u.dst);
 		rt = nrt;
@@ -551,7 +553,7 @@ restart:
 		dst_hold(&rt->u.dst);
 		read_unlock_bh(&rt6_lock);
 
-		nrt = rt6_cow(rt, &fl->fl6_dst, &fl->fl6_src);
+		nrt = rt6_cow(rt, &fl->fl6_dst, &fl->fl6_src, NULL);
 
 		dst_release(&rt->u.dst);
 		rt = nrt;
@@ -598,7 +600,7 @@ static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
 
 	if (rt) {
 		if (rt->rt6i_flags & RTF_CACHE)
-			ip6_del_rt(rt, NULL, NULL);
+			ip6_del_rt(rt, NULL, NULL, NULL);
 		else
 			dst_release(dst);
 	}
@@ -787,7 +789,8 @@ int ipv6_get_hoplimit(struct net_device *dev)
  *
  */
 
-int ip6_route_add(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, void *_rtattr)
+int ip6_route_add(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, 
+		void *_rtattr, struct netlink_skb_parms *req)
 {
 	int err;
 	struct rtmsg *r;
@@ -974,7 +977,7 @@ install_route:
 		rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
 	rt->u.dst.dev = dev;
 	rt->rt6i_idev = idev;
-	return ip6_ins_rt(rt, nlh, _rtattr);
+	return ip6_ins_rt(rt, nlh, _rtattr, req);
 
 out:
 	if (dev)
@@ -986,7 +989,7 @@ out:
 	return err;
 }
 
-int ip6_del_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr)
+int ip6_del_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req)
 {
 	int err;
 
@@ -994,7 +997,7 @@ int ip6_del_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr)
 
 	rt6_reset_dflt_pointer(NULL);
 
-	err = fib6_del(rt, nlh, _rtattr);
+	err = fib6_del(rt, nlh, _rtattr, req);
 	dst_release(&rt->u.dst);
 
 	write_unlock_bh(&rt6_lock);
@@ -1002,7 +1005,7 @@ int ip6_del_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr)
 	return err;
 }
 
-static int ip6_route_del(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, void *_rtattr)
+static int ip6_route_del(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req)
 {
 	struct fib6_node *fn;
 	struct rt6_info *rt;
@@ -1029,7 +1032,7 @@ static int ip6_route_del(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, void *_r
 			dst_hold(&rt->u.dst);
 			read_unlock_bh(&rt6_lock);
 
-			return ip6_del_rt(rt, nlh, _rtattr);
+			return ip6_del_rt(rt, nlh, _rtattr, req);
 		}
 	}
 	read_unlock_bh(&rt6_lock);
@@ -1136,11 +1139,11 @@ source_ok:
 	nrt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(neigh->dev);
 	nrt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&nrt->u.dst));
 
-	if (ip6_ins_rt(nrt, NULL, NULL))
+	if (ip6_ins_rt(nrt, NULL, NULL, NULL))
 		goto out;
 
 	if (rt->rt6i_flags&RTF_CACHE) {
-		ip6_del_rt(rt, NULL, NULL);
+		ip6_del_rt(rt, NULL, NULL, NULL);
 		return;
 	}
 
@@ -1204,7 +1207,7 @@ void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr,
 	   2. It is gatewayed route or NONEXTHOP route. Action: clone it.
 	 */
 	if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) {
-		nrt = rt6_cow(rt, daddr, saddr);
+		nrt = rt6_cow(rt, daddr, saddr, NULL);
 		if (!nrt->u.dst.error) {
 			nrt->u.dst.metrics[RTAX_MTU-1] = pmtu;
 			if (allfrag)
@@ -1232,7 +1235,7 @@ void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr,
 		nrt->u.dst.metrics[RTAX_MTU-1] = pmtu;
 		if (allfrag)
 			nrt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG;
-		ip6_ins_rt(nrt, NULL, NULL);
+		ip6_ins_rt(nrt, NULL, NULL, NULL);
 	}
 
 out:
@@ -1305,7 +1308,7 @@ struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr,
 
 	rtmsg.rtmsg_ifindex = dev->ifindex;
 
-	ip6_route_add(&rtmsg, NULL, NULL);
+	ip6_route_add(&rtmsg, NULL, NULL, NULL);
 	return rt6_get_dflt_router(gwaddr, dev);
 }
 
@@ -1323,7 +1326,7 @@ restart:
 
 			read_unlock_bh(&rt6_lock);
 
-			ip6_del_rt(rt, NULL, NULL);
+			ip6_del_rt(rt, NULL, NULL, NULL);
 
 			goto restart;
 		}
@@ -1349,10 +1352,10 @@ int ipv6_route_ioctl(unsigned int cmd, void __user *arg)
 		rtnl_lock();
 		switch (cmd) {
 		case SIOCADDRT:
-			err = ip6_route_add(&rtmsg, NULL, NULL);
+			err = ip6_route_add(&rtmsg, NULL, NULL, NULL);
 			break;
 		case SIOCDELRT:
-			err = ip6_route_del(&rtmsg, NULL, NULL);
+			err = ip6_route_del(&rtmsg, NULL, NULL, NULL);
 			break;
 		default:
 			err = -EINVAL;
@@ -1546,7 +1549,7 @@ int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 
 	if (inet6_rtm_to_rtmsg(r, arg, &rtmsg))
 		return -EINVAL;
-	return ip6_route_del(&rtmsg, nlh, arg);
+	return ip6_route_del(&rtmsg, nlh, arg, &NETLINK_CB(skb));
 }
 
 int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
@@ -1556,7 +1559,7 @@ int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 
 	if (inet6_rtm_to_rtmsg(r, arg, &rtmsg))
 		return -EINVAL;
-	return ip6_route_add(&rtmsg, nlh, arg);
+	return ip6_route_add(&rtmsg, nlh, arg, &NETLINK_CB(skb));
 }
 
 struct rt6_rtnl_dump_arg
@@ -1566,12 +1569,9 @@ struct rt6_rtnl_dump_arg
 };
 
 static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
-			 struct in6_addr *dst,
-			 struct in6_addr *src,
-			 int iif,
-			 int type, u32 pid, u32 seq,
-			 struct nlmsghdr *in_nlh, int prefix,
-			 unsigned int flags)
+			 struct in6_addr *dst, struct in6_addr *src,
+			 int iif, int type, u32 pid, u32 seq,
+			 int prefix, unsigned int flags)
 {
 	struct rtmsg *rtm;
 	struct nlmsghdr  *nlh;
@@ -1585,10 +1585,6 @@ static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
 		}
 	}
 
-	if (!pid && in_nlh) {
-		pid = in_nlh->nlmsg_pid;
-	}
-
 	nlh = NLMSG_NEW(skb, pid, seq, type, sizeof(*rtm), flags);
 	rtm = NLMSG_DATA(nlh);
 	rtm->rtm_family = AF_INET6;
@@ -1675,7 +1671,7 @@ static int rt6_dump_route(struct rt6_info *rt, void *p_arg)
 
 	return rt6_fill_node(arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE,
 		     NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq,
-		     NULL, prefix, NLM_F_MULTI);
+		     prefix, NLM_F_MULTI);
 }
 
 static int fib6_dump_node(struct fib6_walker_t *w)
@@ -1823,7 +1819,7 @@ 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, 0, 0);
+			    nlh->nlmsg_seq, 0, 0);
 	if (err < 0) {
 		err = -EMSGSIZE;
 		goto out_free;
@@ -1839,17 +1835,25 @@ out_free:
 	goto out;	
 }
 
-void inet6_rt_notify(int event, struct rt6_info *rt, struct nlmsghdr *nlh)
+void inet6_rt_notify(int event, struct rt6_info *rt, struct nlmsghdr *nlh, 
+			struct netlink_skb_parms *req)
 {
 	struct sk_buff *skb;
 	int size = NLMSG_SPACE(sizeof(struct rtmsg)+256);
+	u32 pid = current->pid;
+	u32 seq = 0;
 
+	if (req)
+		pid = req->pid;
+	if (nlh)
+		seq = nlh->nlmsg_seq;
+	
 	skb = alloc_skb(size, gfp_any());
 	if (!skb) {
 		netlink_set_err(rtnl, 0, RTMGRP_IPV6_ROUTE, ENOBUFS);
 		return;
 	}
-	if (rt6_fill_node(skb, rt, NULL, NULL, 0, event, 0, 0, nlh, 0, 0) < 0) {
+	if (rt6_fill_node(skb, rt, NULL, NULL, 0, event, pid, seq, 0, 0) < 0) {
 		kfree_skb(skb);
 		netlink_set_err(rtnl, 0, RTMGRP_IPV6_ROUTE, EINVAL);
 		return;