From:   Gagan Kumar <gagan1kumar.cs@gmail.com>
To:     kuba@kernel.org, jk@codeconstruct.com.au
Cc:     matt@codeconstruct.com.au, davem@davemloft.net,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Gagan Kumar <gagan1kumar.cs@gmail.com>
Subject: [PATCH v2] mctp: Remove only static neighbour on RTM_DELNEIGH
Date:   Sat,  1 Jan 2022 11:11:25 +0530
Message-Id: <20220101054125.9104-1-gagan1kumar.cs@gmail.com>
In-Reply-To: <20211231181709.7f46dbfc@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net>
References: <20211231181709.7f46dbfc@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net>
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Precedence: bulk

Add neighbour source flag in mctp_neigh_remove(...) to allow removal of
only static neighbours.

This should be a no-op change and might be useful later when mctp can
have MCTP_NEIGH_DISCOVER neighbours.

Signed-off-by: Gagan Kumar <gagan1kumar.cs@gmail.com>
---
Changes in v2:
  - Add motivation and impact in the commit message.
  - Split long line > 80 chars into two.

 net/mctp/neigh.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/mctp/neigh.c b/net/mctp/neigh.c
index 5cc042121493..6ad3e33bd4d4 100644
--- a/net/mctp/neigh.c
+++ b/net/mctp/neigh.c
@@ -85,8 +85,8 @@ void mctp_neigh_remove_dev(struct mctp_dev *mdev)
 	mutex_unlock(&net->mctp.neigh_lock);
 }
 
-// TODO: add a "source" flag so netlink can only delete static neighbours?
-static int mctp_neigh_remove(struct mctp_dev *mdev, mctp_eid_t eid)
+static int mctp_neigh_remove(struct mctp_dev *mdev, mctp_eid_t eid,
+			     enum mctp_neigh_source source)
 {
 	struct net *net = dev_net(mdev->dev);
 	struct mctp_neigh *neigh, *tmp;
@@ -94,7 +94,8 @@ static int mctp_neigh_remove(struct mctp_dev *mdev, mctp_eid_t eid)
 
 	mutex_lock(&net->mctp.neigh_lock);
 	list_for_each_entry_safe(neigh, tmp, &net->mctp.neighbours, list) {
-		if (neigh->dev == mdev && neigh->eid == eid) {
+		if (neigh->dev == mdev && neigh->eid == eid &&
+		    neigh->source == source) {
 			list_del_rcu(&neigh->list);
 			/* TODO: immediate RTM_DELNEIGH */
 			call_rcu(&neigh->rcu, __mctp_neigh_free);
@@ -202,7 +203,7 @@ static int mctp_rtm_delneigh(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (!mdev)
 		return -ENODEV;
 
-	return mctp_neigh_remove(mdev, eid);
+	return mctp_neigh_remove(mdev, eid, MCTP_NEIGH_STATIC);
 }
 
 static int mctp_fill_neigh(struct sk_buff *skb, u32 portid, u32 seq, int event,
-- 
2.32.0