From 26c190d2802ebc17563c8fc467c8bb74eab6a2d9 Mon Sep 17 00:00:00 2001
From: "Alexander V. Chernikov" <melifaro@FreeBSD.org>
Date: Sat, 24 Sep 2022 19:17:27 +0000
Subject: [PATCH] if_clone: add ifc_link_ifp() / ifc_unlink_ifp() to the KPI

Factor cloner ifp addition/deletion into separate functions and
 make them public. This change simlifies the current cloner code
 and paves the way to the other upcoming cloner / epair changes.

MFC after:	2 weeks
---
 sys/net/if_clone.c | 81 ++++++++++++++++++++++++++++------------------
 sys/net/if_clone.h |  3 ++
 2 files changed, 53 insertions(+), 31 deletions(-)

diff --git a/sys/net/if_clone.c b/sys/net/if_clone.c
index 50664c28ff88..8360fb4d1d27 100644
--- a/sys/net/if_clone.c
+++ b/sys/net/if_clone.c
@@ -227,7 +227,7 @@ if_clone_create(char *name, size_t len, caddr_t params)
 }
 
 void
-if_clone_addif(struct if_clone *ifc, struct ifnet *ifp)
+ifc_link_ifp(struct if_clone *ifc, struct ifnet *ifp)
 {
 
 	if ((ifc->ifc_flags & IFC_NOGROUP) == 0)
@@ -238,6 +238,50 @@ if_clone_addif(struct if_clone *ifc, struct ifnet *ifp)
 	IF_CLONE_UNLOCK(ifc);
 }
 
+void
+if_clone_addif(struct if_clone *ifc, struct ifnet *ifp)
+{
+	ifc_link_ifp(ifc, ifp);
+}
+
+bool
+ifc_unlink_ifp(struct if_clone *ifc, struct ifnet *ifp)
+{
+	struct ifnet *ifcifp;
+
+	IF_CLONE_LOCK(ifc);
+	LIST_FOREACH(ifcifp, &ifc->ifc_iflist, if_clones) {
+		if (ifcifp == ifp) {
+			IFC_IFLIST_REMOVE(ifc, ifp);
+			break;
+		}
+	}
+	IF_CLONE_UNLOCK(ifc);
+
+	if (ifcifp != NULL && (ifc->ifc_flags & IFC_F_NOGROUP) == 0)
+		if_delgroup(ifp, ifc->ifc_name);
+
+	return (ifcifp != NULL);
+}
+
+static struct if_clone *
+ifc_find_cloner(const char *name, struct vnet *vnet)
+{
+	struct if_clone *ifc;
+
+	CURVNET_SET_QUIET(vnet);
+	IF_CLONERS_LOCK();
+	LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
+		if (strcmp(ifc->ifc_name, name) == 0) {
+			break;
+		}
+	}
+	IF_CLONERS_UNLOCK();
+	CURVNET_RESTORE();
+
+	return (ifc);
+}
+
 /*
  * Create a clone network interface.
  */
@@ -281,16 +325,7 @@ if_clone_destroy(const char *name)
 	if (ifp == NULL)
 		return (ENXIO);
 
-	/* Find the cloner for this interface */
-	CURVNET_SET_QUIET(ifp->if_home_vnet);
-	IF_CLONERS_LOCK();
-	LIST_FOREACH(ifc, &V_if_cloners, ifc_list) {
-		if (strcmp(ifc->ifc_name, ifp->if_dname) == 0) {
-			break;
-		}
-	}
-	IF_CLONERS_UNLOCK();
-	CURVNET_RESTORE();
+	ifc = ifc_find_cloner(ifp->if_dname, ifp->if_home_vnet);
 	if (ifc == NULL) {
 		if_rele(ifp);
 		return (EINVAL);
@@ -308,7 +343,6 @@ static int
 if_clone_destroyif_flags(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
 {
 	int err;
-	struct ifnet *ifcifp;
 
 	/*
 	 * Given that the cloned ifnet might be attached to a different
@@ -317,32 +351,17 @@ if_clone_destroyif_flags(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags
 	 */
 	CURVNET_SET_QUIET(ifp->if_vnet);
 
-	IF_CLONE_LOCK(ifc);
-	LIST_FOREACH(ifcifp, &ifc->ifc_iflist, if_clones) {
-		if (ifcifp == ifp) {
-			IFC_IFLIST_REMOVE(ifc, ifp);
-			break;
-		}
-	}
-	IF_CLONE_UNLOCK(ifc);
-	if (ifcifp == NULL) {
+	if (!ifc_unlink_ifp(ifc, ifp)) {
 		CURVNET_RESTORE();
 		return (ENXIO);		/* ifp is not on the list. */
 	}
-	if ((ifc->ifc_flags & IFC_F_NOGROUP) == 0)
-		if_delgroup(ifp, ifc->ifc_name);
 
 	int unit = ifp->if_dunit;
 	err = (*ifc->ifc_destroy)(ifc, ifp, flags);
 
-	if (err != 0) {
-		if ((ifc->ifc_flags & IFC_F_NOGROUP) == 0)
-			if_addgroup(ifp, ifc->ifc_name);
-
-		IF_CLONE_LOCK(ifc);
-		IFC_IFLIST_INSERT(ifc, ifp);
-		IF_CLONE_UNLOCK(ifc);
-	} else if (ifc->ifc_flags & IFC_F_AUTOUNIT)
+	if (err != 0)
+		ifc_link_ifp(ifc, ifp);
+	else if (ifc->ifc_flags & IFC_F_AUTOUNIT)
 		ifc_free_unit(ifc, unit);
 	CURVNET_RESTORE();
 	return (err);
diff --git a/sys/net/if_clone.h b/sys/net/if_clone.h
index de20eef993f4..1d918a012a5b 100644
--- a/sys/net/if_clone.h
+++ b/sys/net/if_clone.h
@@ -78,6 +78,9 @@ void ifc_detach_cloner(struct if_clone *ifc);
 int ifc_create_ifp(const char *name, struct ifc_data *ifd,
     struct ifnet **ifpp);
 
+void ifc_link_ifp(struct if_clone *ifc, struct ifnet *ifp);
+bool ifc_unlink_ifp(struct if_clone *ifc, struct ifnet *ifp);
+
 int ifc_copyin(const struct ifc_data *ifd, void *target, size_t len);
 #ifdef CLONE_COMPAT_13