[PATCH net-next 10/12] nexthop: Extract a helper for walking the next-hop tree

[Petr Machata]

Extract from rtm_dump_nexthop() a helper to walk the next hop tree. A
separate function for this will be reusable from the bucket dumper.

Signed-off-by: Petr Machata <pe...@nvidia.com>
Reviewed-by: Ido Schimmel <ido...@nvidia.com>
---
 net/ipv4/nexthop.c | 52 +++++++++++++++++++++++++++++-----------------
 1 file changed, 33 insertions(+), 19 deletions(-)

diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 7ae197efa5a9..e5175f531ffb 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -2079,22 +2079,17 @@ rtm_dump_nh_ctx(struct netlink_callback *cb)
        return ctx;
 }
 
-/* rtnl */
-static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
+static int rtm_dump_walk_nexthops(struct sk_buff *skb,
+                                 struct netlink_callback *cb,
+                                 struct rb_root *root,
+                                 struct rtm_dump_nh_ctx *ctx,
+                                 struct nh_dump_filter *filter)
 {
-       struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb);
        struct nhmsg *nhm = nlmsg_data(cb->nlh);
-       struct net *net = sock_net(skb->sk);
-       struct rb_root *root = &net->nexthop.rb_root;
-       struct nh_dump_filter filter = {};
        struct rb_node *node;
        int idx = 0, s_idx;
        int err;
 
-       err = nh_valid_dump_req(cb->nlh, &filter, cb);
-       if (err < 0)
-               return err;
-
        s_idx = ctx->idx;
        for (node = rb_first(root); node; node = rb_next(node)) {
                struct nexthop *nh;
@@ -2103,29 +2098,48 @@ static int rtm_dump_nexthop(struct sk_buff *skb, struct 
netlink_callback *cb)
                        goto cont;
 
                nh = rb_entry(node, struct nexthop, rb_node);
-               if (nh_dump_filtered(nh, &filter, nhm->nh_family))
+               if (nh_dump_filtered(nh, filter, nhm->nh_family))
                        goto cont;
 
+               ctx->idx = idx;
                err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
                                   NETLINK_CB(cb->skb).portid,
                                   cb->nlh->nlmsg_seq, NLM_F_MULTI);
-               if (err < 0) {
-                       if (likely(skb->len))
-                               goto out;
-
-                       goto out_err;
-               }
+               if (err < 0)
+                       return err;
 cont:
                idx++;
        }
 
+       ctx->idx = idx;
+       return 0;
+}
+
+/* rtnl */
+static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
+{
+       struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb);
+       struct net *net = sock_net(skb->sk);
+       struct rb_root *root = &net->nexthop.rb_root;
+       struct nh_dump_filter filter = {};
+       int err;
+
+       err = nh_valid_dump_req(cb->nlh, &filter, cb);
+       if (err < 0)
+               return err;
+
+       err = rtm_dump_walk_nexthops(skb, cb, root, ctx, &filter);
+       if (err < 0) {
+               if (likely(skb->len))
+                       goto out;
+               goto out_err;
+       }
+
 out:
        err = skb->len;
 out_err:
-       ctx->idx = idx;
        cb->seq = net->nexthop.seq;
        nl_dump_check_consistent(cb, nlmsg_hdr(skb));
-
        return err;
 }
 
-- 
2.26.2