Merge branch 'mana-shared' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

Leon Romanovsky says:

====================
net: mana: Allow variable size indirection table

Like we talked, I created new shared branch for this patch:
https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/log/?h=mana-shared

* 'mana-shared' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
   net: mana: Allow variable size indirection table
====================

Link: https://lore.kernel.org/all/20240612183051.GE4966@unreal
Signed-off-by: Leon Romanovsky <leon@kernel.org>

1 files changed, 42 insertions, 2 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index b86b0a87367d..4668d6718040 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -6484,6 +6484,46 @@ static int rtnl_mdb_del(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 /* Process one rtnetlink message. */
 
+static int rtnl_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	rtnl_dumpit_func dumpit = cb->data;
+	int err;
+
+	/* Previous iteration have already finished, avoid calling->dumpit()
+	 * again, it may not expect to be called after it reached the end.
+	 */
+	if (!dumpit)
+		return 0;
+
+	err = dumpit(skb, cb);
+
+	/* Old dump handlers used to send NLM_DONE as in a separate recvmsg().
+	 * Some applications which parse netlink manually depend on this.
+	 */
+	if (cb->flags & RTNL_FLAG_DUMP_SPLIT_NLM_DONE) {
+		if (err < 0 && err != -EMSGSIZE)
+			return err;
+		if (!err)
+			cb->data = NULL;
+
+		return skb->len;
+	}
+	return err;
+}
+
+static int rtnetlink_dump_start(struct sock *ssk, struct sk_buff *skb,
+				const struct nlmsghdr *nlh,
+				struct netlink_dump_control *control)
+{
+	if (control->flags & RTNL_FLAG_DUMP_SPLIT_NLM_DONE) {
+		WARN_ON(control->data);
+		control->data = control->dump;
+		control->dump = rtnl_dumpit;
+	}
+
+	return netlink_dump_start(ssk, skb, nlh, control);
+}
+
 static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 			     struct netlink_ext_ack *extack)
 {
@@ -6548,7 +6588,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
 				.module		= owner,
 				.flags		= flags,
 			};
-			err = netlink_dump_start(rtnl, skb, nlh, &c);
+			err = rtnetlink_dump_start(rtnl, skb, nlh, &c);
 			/* netlink_dump_start() will keep a reference on
 			 * module if dump is still in progress.
 			 */
@@ -6694,7 +6734,7 @@ void __init rtnetlink_init(void)
 	register_netdevice_notifier(&rtnetlink_dev_notifier);
 
 	rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink,
-		      rtnl_dump_ifinfo, 0);
+		      rtnl_dump_ifinfo, RTNL_FLAG_DUMP_SPLIT_NLM_DONE);
 	rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL, 0);
 	rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL, 0);
 	rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL, 0);