decnet: Parse netlink attributes on our own

decnet is the only subsystem left that is relying on the global
netlink attribute buffer rta_buf. It's horrible design and we
want to get rid of it.

This converts all of decnet to do implicit attribute parsing. It
also gets rid of the error prone struct dn_kern_rta.

Yes, the fib_magic() stuff is not pretty.

It's compiled tested but I need someone with appropriate hardware
to test the patch since I don't have access to it.

Cc: linux-decnet-user@lists.sourceforge.net
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 154 insertions, 126 deletions

diff --git a/net/decnet/dn_fib.c b/net/decnet/dn_fib.c
index e36614eccc04..42a8048fe725 100644
--- a/net/decnet/dn_fib.c
+++ b/net/decnet/dn_fib.c
@@ -145,22 +145,10 @@ static inline struct dn_fib_info *dn_fib_find_info(const struct dn_fib_info *nfi
         return NULL;
 }
 
-__le16 dn_fib_get_attr16(struct rtattr *attr, int attrlen, int type)
+static int dn_fib_count_nhs(const struct nlattr *attr)
 {
-        while(RTA_OK(attr,attrlen)) {
-                if (attr->rta_type == type)
-                        return *(__le16*)RTA_DATA(attr);
-                attr = RTA_NEXT(attr, attrlen);
-        }
-
-        return 0;
-}
-
-static int dn_fib_count_nhs(struct rtattr *rta)
-{
-        int nhs = 0;
-        struct rtnexthop *nhp = RTA_DATA(rta);
-        int nhlen = RTA_PAYLOAD(rta);
+        struct rtnexthop *nhp = nla_data(attr);
+        int nhs = 0, nhlen = nla_len(attr);
 
         while(nhlen >= (int)sizeof(struct rtnexthop)) {
                 if ((nhlen -= nhp->rtnh_len) < 0)
@@ -172,10 +160,11 @@ static int dn_fib_count_nhs(struct rtattr *rta)
         return nhs;
 }
 
-static int dn_fib_get_nhs(struct dn_fib_info *fi, const struct rtattr *rta, const struct rtmsg *r)
+static int dn_fib_get_nhs(struct dn_fib_info *fi, const struct nlattr *attr,
+                          const struct rtmsg *r)
 {
-        struct rtnexthop *nhp = RTA_DATA(rta);
-        int nhlen = RTA_PAYLOAD(rta);
+        struct rtnexthop *nhp = nla_data(attr);
+        int nhlen = nla_len(attr);
 
         change_nexthops(fi) {
                 int attrlen = nhlen - sizeof(struct rtnexthop);
@@ -187,7 +176,10 @@ static int dn_fib_get_nhs(struct dn_fib_info *fi, const struct rtattr *rta, cons
                 nh->nh_weight = nhp->rtnh_hops + 1;
 
                 if (attrlen) {
-                        nh->nh_gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
+                        struct nlattr *gw_attr;
+
+                        gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
+                        nh->nh_gw = gw_attr ? nla_get_le16(gw_attr) : 0;
                 }
                 nhp = RTNH_NEXT(nhp);
         } endfor_nexthops(fi);
@@ -268,7 +260,8 @@ out:
 }
 
 
-struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct dn_kern_rta *rta, const struct nlmsghdr *nlh, int *errp)
+struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct nlattr *attrs[],
+                                       const struct nlmsghdr *nlh, int *errp)
 {
         int err;
         struct dn_fib_info *fi = NULL;
@@ -281,11 +274,9 @@ struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct dn_kern_rta
         if (dn_fib_props[r->rtm_type].scope > r->rtm_scope)
                 goto err_inval;
 
-        if (rta->rta_mp) {
-                nhs = dn_fib_count_nhs(rta->rta_mp);
-                if (nhs == 0)
-                        goto err_inval;
-        }
+        if (attrs[RTA_MULTIPATH] &&
+            (nhs = dn_fib_count_nhs(attrs[RTA_MULTIPATH])) == 0)
+                goto err_inval;
 
         fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct dn_fib_nh), GFP_KERNEL);
         err = -ENOBUFS;
@@ -295,53 +286,65 @@ struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct dn_kern_rta
         fi->fib_protocol = r->rtm_protocol;
         fi->fib_nhs = nhs;
         fi->fib_flags = r->rtm_flags;
-        if (rta->rta_priority)
-                fi->fib_priority = *rta->rta_priority;
-        if (rta->rta_mx) {
-                int attrlen = RTA_PAYLOAD(rta->rta_mx);
-                struct rtattr *attr = RTA_DATA(rta->rta_mx);
 
-                while(RTA_OK(attr, attrlen)) {
-                        unsigned int flavour = attr->rta_type;
+        if (attrs[RTA_PRIORITY])
+                fi->fib_priority = nla_get_u32(attrs[RTA_PRIORITY]);
+
+        if (attrs[RTA_METRICS]) {
+                struct nlattr *attr;
+                int rem;
 
-                        if (flavour) {
-                                if (flavour > RTAX_MAX)
+                nla_for_each_nested(attr, attrs[RTA_METRICS], rem) {
+                        int type = nla_type(attr);
+
+                        if (type) {
+                                if (type > RTAX_MAX || nla_len(attr) < 4)
                                         goto err_inval;
-                                fi->fib_metrics[flavour-1] = *(unsigned int *)RTA_DATA(attr);
+
+                                fi->fib_metrics[type-1] = nla_get_u32(attr);
                         }
-                        attr = RTA_NEXT(attr, attrlen);
                 }
         }
-        if (rta->rta_prefsrc)
-                memcpy(&fi->fib_prefsrc, rta->rta_prefsrc, 2);
 
-        if (rta->rta_mp) {
-                if ((err = dn_fib_get_nhs(fi, rta->rta_mp, r)) != 0)
+        if (attrs[RTA_PREFSRC])
+                fi->fib_prefsrc = nla_get_le16(attrs[RTA_PREFSRC]);
+
+        if (attrs[RTA_MULTIPATH]) {
+                if ((err = dn_fib_get_nhs(fi, attrs[RTA_MULTIPATH], r)) != 0)
                         goto failure;
-                if (rta->rta_oif && fi->fib_nh->nh_oif != *rta->rta_oif)
+
+                if (attrs[RTA_OIF] &&
+                    fi->fib_nh->nh_oif != nla_get_u32(attrs[RTA_OIF]))
                         goto err_inval;
-                if (rta->rta_gw && memcmp(&fi->fib_nh->nh_gw, rta->rta_gw, 2))
+
+                if (attrs[RTA_GATEWAY] &&
+                    fi->fib_nh->nh_gw != nla_get_le16(attrs[RTA_GATEWAY]))
                         goto err_inval;
         } else {
                 struct dn_fib_nh *nh = fi->fib_nh;
-                if (rta->rta_oif)
-                        nh->nh_oif = *rta->rta_oif;
-                if (rta->rta_gw)
-                        memcpy(&nh->nh_gw, rta->rta_gw, 2);
+
+                if (attrs[RTA_OIF])
+                        nh->nh_oif = nla_get_u32(attrs[RTA_OIF]);
+
+                if (attrs[RTA_GATEWAY])
+                        nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);
+
                 nh->nh_flags = r->rtm_flags;
                 nh->nh_weight = 1;
         }
 
         if (r->rtm_type == RTN_NAT) {
-                if (rta->rta_gw == NULL || nhs != 1 || rta->rta_oif)
+                if (!attrs[RTA_GATEWAY] || nhs != 1 || attrs[RTA_OIF])
                         goto err_inval;
-                memcpy(&fi->fib_nh->nh_gw, rta->rta_gw, 2);
+
+                fi->fib_nh->nh_gw = nla_get_le16(attrs[RTA_GATEWAY]);
                 goto link_it;
         }
 
         if (dn_fib_props[r->rtm_type].error) {
-                if (rta->rta_gw || rta->rta_oif || rta->rta_mp)
+                if (attrs[RTA_GATEWAY] || attrs[RTA_OIF] || attrs[RTA_MULTIPATH])
                         goto err_inval;
+
                 goto link_it;
         }
 
@@ -367,8 +370,8 @@ struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct dn_kern_rta
         }
 
         if (fi->fib_prefsrc) {
-                if (r->rtm_type != RTN_LOCAL || rta->rta_dst == NULL ||
-                    memcmp(&fi->fib_prefsrc, rta->rta_dst, 2))
+                if (r->rtm_type != RTN_LOCAL || !attrs[RTA_DST] ||
+                    fi->fib_prefsrc != nla_get_le16(attrs[RTA_DST]))
                         if (dnet_addr_type(fi->fib_prefsrc) != RTN_LOCAL)
                                 goto err_inval;
         }
@@ -486,29 +489,24 @@ void dn_fib_select_multipath(const struct flowidn *fld, struct dn_fib_res *res)
         spin_unlock_bh(&dn_fib_multipath_lock);
 }
 
+const struct nla_policy rtm_dn_policy[RTA_MAX + 1] = {
+        [RTA_DST]               = { .type = NLA_U16 },
+        [RTA_SRC]               = { .type = NLA_U16 },
+        [RTA_IIF]               = { .type = NLA_U32 },
+        [RTA_OIF]               = { .type = NLA_U32 },
+        [RTA_GATEWAY]           = { .type = NLA_U16 },
+        [RTA_PRIORITY]          = { .type = NLA_U32 },
+        [RTA_PREFSRC]           = { .type = NLA_U16 },
+        [RTA_METRICS]           = { .type = NLA_NESTED },
+        [RTA_MULTIPATH]         = { .type = NLA_NESTED },
+        [RTA_TABLE]             = { .type = NLA_U32 },
+        [RTA_MARK]              = { .type = NLA_U32 },
+};
 
-static int dn_fib_check_attr(struct rtmsg *r, struct rtattr **rta)
-{
-        int i;
-
-        for(i = 1; i <= RTA_MAX; i++) {
-                struct rtattr *attr = rta[i-1];
-                if (attr) {
-                        if (RTA_PAYLOAD(attr) < 4 && RTA_PAYLOAD(attr) != 2)
-                                return -EINVAL;
-                        if (i != RTA_MULTIPATH && i != RTA_METRICS &&
-                            i != RTA_TABLE)
-                                rta[i-1] = (struct rtattr *)RTA_DATA(attr);
-                }
-        }
-
-        return 0;
-}
-
-static inline u32 rtm_get_table(struct rtattr **rta, u8 table)
+static inline u32 rtm_get_table(struct nlattr *attrs[], u8 table)
 {
-        if (rta[RTA_TABLE - 1])
-                table = nla_get_u32((struct nlattr *) rta[RTA_TABLE - 1]);
+        if (attrs[RTA_TABLE])
+                table = nla_get_u32(attrs[RTA_TABLE]);
 
         return table;
 }
@@ -517,8 +515,9 @@ static int dn_fib_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *
 {
         struct net *net = sock_net(skb->sk);
         struct dn_fib_table *tb;
-        struct rtattr **rta = arg;
-        struct rtmsg *r = NLMSG_DATA(nlh);
+        struct rtmsg *r = nlmsg_data(nlh);
+        struct nlattr *attrs[RTA_MAX+1];
+        int err;
 
         if (!capable(CAP_NET_ADMIN))
                 return -EPERM;
@@ -526,22 +525,24 @@ static int dn_fib_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *
         if (!net_eq(net, &init_net))
                 return -EINVAL;
 
-        if (dn_fib_check_attr(r, rta))
-                return -EINVAL;
+        err = nlmsg_parse(nlh, sizeof(*r), attrs, RTA_MAX, rtm_dn_policy);
+        if (err < 0)
+                return err;
 
-        tb = dn_fib_get_table(rtm_get_table(rta, r->rtm_table), 0);
-        if (tb)
-                return tb->delete(tb, r, (struct dn_kern_rta *)rta, nlh, &NETLINK_CB(skb));
+        tb = dn_fib_get_table(rtm_get_table(attrs, r->rtm_table), 0);
+        if (!tb)
+                return -ESRCH;
 
-        return -ESRCH;
+        return tb->delete(tb, r, attrs, nlh, &NETLINK_CB(skb));
 }
 
 static int dn_fib_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 {
         struct net *net = sock_net(skb->sk);
         struct dn_fib_table *tb;
-        struct rtattr **rta = arg;
-        struct rtmsg *r = NLMSG_DATA(nlh);
+        struct rtmsg *r = nlmsg_data(nlh);
+        struct nlattr *attrs[RTA_MAX+1];
+        int err;
 
         if (!capable(CAP_NET_ADMIN))
                 return -EPERM;
@@ -549,14 +550,15 @@ static int dn_fib_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *
         if (!net_eq(net, &init_net))
                 return -EINVAL;
 
-        if (dn_fib_check_attr(r, rta))
-                return -EINVAL;
+        err = nlmsg_parse(nlh, sizeof(*r), attrs, RTA_MAX, rtm_dn_policy);
+        if (err < 0)
+                return err;
 
-        tb = dn_fib_get_table(rtm_get_table(rta, r->rtm_table), 1);
-        if (tb)
-                return tb->insert(tb, r, (struct dn_kern_rta *)rta, nlh, &NETLINK_CB(skb));
+        tb = dn_fib_get_table(rtm_get_table(attrs, r->rtm_table), 1);
+        if (!tb)
+                return -ENOBUFS;
 
-        return -ENOBUFS;
+        return tb->insert(tb, r, attrs, nlh, &NETLINK_CB(skb));
 }
 
 static void fib_magic(int cmd, int type, __le16 dst, int dst_len, struct dn_ifaddr *ifa)
@@ -566,10 +568,31 @@ static void fib_magic(int cmd, int type, __le16 dst, int dst_len, struct dn_ifad
                 struct nlmsghdr nlh;
                 struct rtmsg rtm;
         } req;
-        struct dn_kern_rta rta;
+        struct {
+                struct nlattr hdr;
+                __le16 dst;
+        } dst_attr = {
+                .dst = dst,
+        };
+        struct {
+                struct nlattr hdr;
+                __le16 prefsrc;
+        } prefsrc_attr = {
+                .prefsrc = ifa->ifa_local,
+        };
+        struct {
+                struct nlattr hdr;
+                u32 oif;
+        } oif_attr = {
+                .oif = ifa->ifa_dev->dev->ifindex,
+        };
+        struct nlattr *attrs[RTA_MAX+1] = {
+                [RTA_DST] = (struct nlattr *) &dst_attr,
+                [RTA_PREFSRC] = (struct nlattr * ) &prefsrc_attr,
+                [RTA_OIF] = (struct nlattr *) &oif_attr,
+        };
 
         memset(&req.rtm, 0, sizeof(req.rtm));
-        memset(&rta, 0, sizeof(rta));
 
         if (type == RTN_UNICAST)
                 tb = dn_fib_get_table(RT_MIN_TABLE, 1);
@@ -591,14 +614,10 @@ static void fib_magic(int cmd, int type, __le16 dst, int dst_len, struct dn_ifad
         req.rtm.rtm_scope = (type != RTN_LOCAL ? RT_SCOPE_LINK : RT_SCOPE_HOST);
         req.rtm.rtm_type = type;
 
-        rta.rta_dst = &dst;
-        rta.rta_prefsrc = &ifa->ifa_local;
-        rta.rta_oif = &ifa->ifa_dev->dev->ifindex;
-
         if (cmd == RTM_NEWROUTE)
-                tb->insert(tb, &req.rtm, &rta, &req.nlh, NULL);
+                tb->insert(tb, &req.rtm, attrs, &req.nlh, NULL);
         else
-                tb->delete(tb, &req.rtm, &rta, &req.nlh, NULL);
+                tb->delete(tb, &req.rtm, attrs, &req.nlh, NULL);
 }
 
 static void dn_fib_add_ifaddr(struct dn_ifaddr *ifa)
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 5ac0e153ef83..b4b3508e77f0 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1619,17 +1619,21 @@ errout:
 static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void *arg)
 {
         struct net *net = sock_net(in_skb->sk);
-        struct rtattr **rta = arg;
         struct rtmsg *rtm = nlmsg_data(nlh);
         struct dn_route *rt = NULL;
         struct dn_skb_cb *cb;
         int err;
         struct sk_buff *skb;
         struct flowidn fld;
+        struct nlattr *tb[RTA_MAX+1];
 
         if (!net_eq(net, &init_net))
                 return -EINVAL;
 
+        err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_dn_policy);
+        if (err < 0)
+                return err;
+
         memset(&fld, 0, sizeof(fld));
         fld.flowidn_proto = DNPROTO_NSP;
 
@@ -1639,12 +1643,14 @@ static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void
         skb_reset_mac_header(skb);
         cb = DN_SKB_CB(skb);
 
-        if (rta[RTA_SRC-1])
-                memcpy(&fld.saddr, RTA_DATA(rta[RTA_SRC-1]), 2);
-        if (rta[RTA_DST-1])
-                memcpy(&fld.daddr, RTA_DATA(rta[RTA_DST-1]), 2);
-        if (rta[RTA_IIF-1])
-                memcpy(&fld.flowidn_iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int));
+        if (tb[RTA_SRC])
+                fld.saddr = nla_get_le16(tb[RTA_SRC]);
+
+        if (tb[RTA_DST])
+                fld.daddr = nla_get_le16(tb[RTA_DST]);
+
+        if (tb[RTA_IIF])
+                fld.flowidn_iif = nla_get_u32(tb[RTA_IIF]);
 
         if (fld.flowidn_iif) {
                 struct net_device *dev;
@@ -1669,10 +1675,9 @@ static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void
                 if (!err && -rt->dst.error)
                         err = rt->dst.error;
         } else {
-                int oif = 0;
-                if (rta[RTA_OIF - 1])
-                        memcpy(&oif, RTA_DATA(rta[RTA_OIF - 1]), sizeof(int));
-                fld.flowidn_oif = oif;
+                if (tb[RTA_OIF])
+                        fld.flowidn_oif = nla_get_u32(tb[RTA_OIF]);
+
                 err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0);
         }
 
diff --git a/net/decnet/dn_table.c b/net/decnet/dn_table.c
index 6c2445bcaba1..fc42a0afd306 100644
--- a/net/decnet/dn_table.c
+++ b/net/decnet/dn_table.c
@@ -224,26 +224,27 @@ static struct dn_zone *dn_new_zone(struct dn_hash *table, int z)
 }
 
 
-static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern_rta *rta, struct dn_fib_info *fi)
+static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct nlattr *attrs[], struct dn_fib_info *fi)
 {
         struct rtnexthop *nhp;
         int nhlen;
 
-        if (rta->rta_priority && *rta->rta_priority != fi->fib_priority)
+        if (attrs[RTA_PRIORITY] &&
+            nla_get_u32(attrs[RTA_PRIORITY]) != fi->fib_priority)
                 return 1;
 
-        if (rta->rta_oif || rta->rta_gw) {
-                if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
-                    (!rta->rta_gw  || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 2) == 0))
+        if (attrs[RTA_OIF] || attrs[RTA_GATEWAY]) {
+                if ((!attrs[RTA_OIF] || nla_get_u32(attrs[RTA_OIF]) == fi->fib_nh->nh_oif) &&
+                    (!attrs[RTA_GATEWAY]  || nla_get_le16(attrs[RTA_GATEWAY]) != fi->fib_nh->nh_gw))
                         return 0;
                 return 1;
         }
 
-        if (rta->rta_mp == NULL)
+        if (!attrs[RTA_MULTIPATH])
                 return 0;
 
-        nhp = RTA_DATA(rta->rta_mp);
-        nhlen = RTA_PAYLOAD(rta->rta_mp);
+        nhp = nla_data(attrs[RTA_MULTIPATH]);
+        nhlen = nla_len(attrs[RTA_MULTIPATH]);
 
         for_nexthops(fi) {
                 int attrlen = nhlen - sizeof(struct rtnexthop);
@@ -254,7 +255,10 @@ static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern
                 if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
                         return 1;
                 if (attrlen) {
-                        gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
+                        struct nlattr *gw_attr;
+
+                        gw_attr = nla_find((struct nlattr *) (nhp + 1), attrlen, RTA_GATEWAY);
+                        gw = gw_attr ? nla_get_le16(gw_attr) : 0;
 
                         if (gw && gw != nh->nh_gw)
                                 return 1;
@@ -517,7 +521,8 @@ out:
         return skb->len;
 }
 
-static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
+static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
+                               struct nlmsghdr *n, struct netlink_skb_parms *req)
 {
         struct dn_hash *table = (struct dn_hash *)tb->data;
         struct dn_fib_node *new_f, *f, **fp, **del_fp;
@@ -536,15 +541,14 @@ static int dn_fib_table_insert(struct dn_fib_table *tb, struct rtmsg *r, struct
                 return -ENOBUFS;
 
         dz_key_0(key);
-        if (rta->rta_dst) {
-                __le16 dst;
-                memcpy(&dst, rta->rta_dst, 2);
+        if (attrs[RTA_DST]) {
+                __le16 dst = nla_get_le16(attrs[RTA_DST]);
                 if (dst & ~DZ_MASK(dz))
                         return -EINVAL;
                 key = dz_key(dst, dz);
         }
 
-        if ((fi = dn_fib_create_info(r, rta, n, &err)) == NULL)
+        if ((fi = dn_fib_create_info(r, attrs, n, &err)) == NULL)
                 return err;
 
         if (dz->dz_nent > (dz->dz_divisor << 2) &&
@@ -654,7 +658,8 @@ out:
 }
 
 
-static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct dn_kern_rta *rta, struct nlmsghdr *n, struct netlink_skb_parms *req)
+static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct nlattr *attrs[],
+                               struct nlmsghdr *n, struct netlink_skb_parms *req)
 {
         struct dn_hash *table = (struct dn_hash*)tb->data;
         struct dn_fib_node **fp, **del_fp, *f;
@@ -671,9 +676,8 @@ static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct
                 return -ESRCH;
 
         dz_key_0(key);
-        if (rta->rta_dst) {
-                __le16 dst;
-                memcpy(&dst, rta->rta_dst, 2);
+        if (attrs[RTA_DST]) {
+                __le16 dst = nla_get_le16(attrs[RTA_DST]);
                 if (dst & ~DZ_MASK(dz))
                         return -EINVAL;
                 key = dz_key(dst, dz);
@@ -703,7 +707,7 @@ static int dn_fib_table_delete(struct dn_fib_table *tb, struct rtmsg *r, struct
                                 (r->rtm_scope == RT_SCOPE_NOWHERE || f->fn_scope == r->rtm_scope) &&
                                 (!r->rtm_protocol ||
                                         fi->fib_protocol == r->rtm_protocol) &&
-                                dn_fib_nh_match(r, n, rta, fi) == 0)
+                                dn_fib_nh_match(r, n, attrs, fi) == 0)
                         del_fp = fp;
         }