From 8dc94a59cfad70ec3a808add56718255eee39ab2 Mon Sep 17 00:00:00 2001
From: Christian Marangi <ansuelsmth@gmail.com>
Date: Sat, 29 Mar 2025 12:50:55 +0100
Subject: [PATCH] backports: handle genlmsg_multicast_allns upstream backport
 changes

Better handle genlmsg_multicast_allns upstream backport changes that
dropped a flag to the function middle version. Use a backport function
if backports project is tried to be built on older kernel version.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 backport-include/net/genetlink.h | 11 +++++
 compat/Makefile                  |  3 +-
 compat/backport-genetlink.c      | 60 +++++++++++++++++++++++
 3 files changed, 73 insertions(+), 1 deletion(-)

--- a/backport-include/net/genetlink.h
+++ b/backport-include/net/genetlink.h
@@ -223,4 +223,15 @@ static inline int genlmsg_parse(const st
 }
 #endif /* LINUX_VERSION_IS_LESS(5,2,0) */
 
+#if LINUX_VERSION_IN_RANGE(5,15,0,5,15,169) || \
+    LINUX_VERSION_IN_RANGE(6,1,0,6,1,115) || \
+    LINUX_VERSION_IN_RANGE(6,6,0,6,6,58)
+#define genlmsg_multicast_allns LINUX_BACKPORT(genlmsg_multicast_allns)
+int backport_genlmsg_multicast_allns(const struct genl_family *family,
+				     struct sk_buff *skb, u32 portid,
+				     unsigned int group);
+#endif /* LINUX_VERSION_IN_RANGE(5,15,0,5,15,169) ||
+	  LINUX_VERSION_IN_RANGE(6,1,0,6,1,115) ||
+	  LINUX_VERSION_IN_RANGE(6,6,0,6,6,58) */
+
 #endif /* __BACKPORT_NET_GENETLINK_H */
--- a/compat/Makefile
+++ b/compat/Makefile
@@ -22,7 +22,8 @@ compat-$(CPTCFG_KERNEL_5_9) += backport-
 compat-$(CPTCFG_KERNEL_5_10) += backport-5.10.o
 compat-$(CPTCFG_KERNEL_5_11) += backport-5.11.o
 compat-$(CPTCFG_KERNEL_5_13) += backport-5.13.o
-compat-$(CPTCFG_KERNEL_5_15) += backport-5.15.o
+compat-$(CPTCFG_KERNEL_5_15) += backport-5.15.o backport-genetlink.o
+compat-$(CPTCFG_KERNEL_6_1) += backport-genetlink.o
 
 compat-$(CPTCFG_BPAUTO_BUILD_SYSTEM_DATA_VERIFICATION) += verification/verify.o
 compat-$(CPTCFG_BPAUTO_BUILD_SYSTEM_DATA_VERIFICATION) += verification/pkcs7.asn1.o
--- a/compat/backport-genetlink.c
+++ b/compat/backport-genetlink.c
@@ -17,6 +17,7 @@
 #include <net/netlink.h>
 #include <net/sock.h>
 
+#if LINUX_VERSION_IS_LESS(5,2,0)
 static const struct genl_family *find_family_real_ops(const struct genl_ops **ops)
 {
 	const struct genl_family *family;
@@ -415,3 +416,63 @@ int backport_genlmsg_multicast_allns(con
 	return genlmsg_mcast(skb, portid, group);
 }
 EXPORT_SYMBOL_GPL(backport_genlmsg_multicast_allns);
+#endif /* LINUX_VERSION_IS_LESS(5,2,0) */
+
+#if LINUX_VERSION_IN_RANGE(5,15,0,5,15,169) || \
+    LINUX_VERSION_IN_RANGE(6,1,0,6,1,115) || \
+    LINUX_VERSION_IN_RANGE(6,6,0,6,6,58)
+static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group)
+{
+	struct sk_buff *tmp;
+	struct net *net, *prev = NULL;
+	bool delivered = false;
+	int err;
+
+	rcu_read_lock();
+	for_each_net_rcu(net) {
+		if (prev) {
+			tmp = skb_clone(skb, GFP_ATOMIC);
+			if (!tmp) {
+				err = -ENOMEM;
+				goto error;
+			}
+			err = nlmsg_multicast(prev->genl_sock, tmp,
+					      portid, group, GFP_ATOMIC);
+			if (!err)
+				delivered = true;
+			else if (err != -ESRCH)
+				goto error;
+		}
+
+		prev = net;
+	}
+	err = nlmsg_multicast(prev->genl_sock, skb, portid, group, GFP_ATOMIC);
+
+	rcu_read_unlock();
+
+	if (!err)
+		delivered = true;
+	else if (err != -ESRCH)
+		return err;
+	return delivered ? 0 : -ESRCH;
+ error:
+	rcu_read_unlock();
+
+	kfree_skb(skb);
+	return err;
+}
+
+int backport_genlmsg_multicast_allns(const struct genl_family *family,
+				     struct sk_buff *skb, u32 portid,
+				     unsigned int group)
+{
+	if (WARN_ON_ONCE(group >= family->n_mcgrps))
+		return -EINVAL;
+
+	group = family->mcgrp_offset + group;
+	return genlmsg_mcast(skb, portid, group);
+}
+EXPORT_SYMBOL_GPL(backport_genlmsg_multicast_allns);
+#endif /* LINUX_VERSION_IN_RANGE(5,15,0,5,15,169) ||
+	  LINUX_VERSION_IN_RANGE(6,1,0,6,1,115) ||
+	  LINUX_VERSION_IN_RANGE(6,6,0,6,6,58) */