From: kn <kn@openbsd.org>
Date: Mon, 14 Nov 2022 22:06:25 +0000 (+0000)
Subject: Document global interface group list locking
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=32ce3e3f29cea362a61a203962d9b193e353ee97;p=openbsd

Document global interface group list locking

The per-interface group list is protected by the net lock and already
documented as such.

The global interface group list `ifg_head' is also protected by the net
lock and all access to it (all within if.c) take it accordingly.

Feedback OK mvs
---

diff --git a/sys/net/if.c b/sys/net/if.c
index a29a011a32b..e80b50fdf83 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.677 2022/11/10 17:17:47 dlg Exp $	*/
+/*	$OpenBSD: if.c,v 1.678 2022/11/14 22:06:25 kn Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -222,7 +222,8 @@ void	if_idxmap_alloc(struct ifnet *);
 void	if_idxmap_insert(struct ifnet *);
 void	if_idxmap_remove(struct ifnet *);
 
-TAILQ_HEAD(, ifg_group) ifg_head = TAILQ_HEAD_INITIALIZER(ifg_head);
+TAILQ_HEAD(, ifg_group) ifg_head =
+    TAILQ_HEAD_INITIALIZER(ifg_head);	/* [N] list of interface groups */
 
 LIST_HEAD(, if_clone) if_cloners =
     LIST_HEAD_INITIALIZER(if_cloners);	/* [I] list of clonable interfaces */
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index b5ebe479b73..3a418bf0547 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_var.h,v 1.119 2022/11/10 12:46:19 kn Exp $	*/
+/*	$OpenBSD: if_var.h,v 1.120 2022/11/14 22:06:26 kn Exp $	*/
 /*	$NetBSD: if.h,v 1.23 1996/05/07 02:40:27 thorpej Exp $	*/
 
 /*
@@ -263,22 +263,22 @@ struct ifmaddr {
  */
 
 struct ifg_group {
-	char			 ifg_group[IFNAMSIZ];
-	u_int			 ifg_refcnt;
-	caddr_t			 ifg_pf_kif;
-	int			 ifg_carp_demoted;
-	TAILQ_HEAD(, ifg_member) ifg_members;
-	TAILQ_ENTRY(ifg_group)	 ifg_next;
+	char			 ifg_group[IFNAMSIZ]; /* [I] group name */
+	u_int			 ifg_refcnt;  /* [N] group reference count */
+	caddr_t			 ifg_pf_kif;  /* [I] pf interface group */
+	int			 ifg_carp_demoted; /* [K] carp demotion counter */
+	TAILQ_HEAD(, ifg_member) ifg_members; /* [N] list of members per group */
+	TAILQ_ENTRY(ifg_group)	 ifg_next;    /* [N] all groups are chained */
 };
 
 struct ifg_member {
-	TAILQ_ENTRY(ifg_member)	 ifgm_next;
-	struct ifnet		*ifgm_ifp;
+	TAILQ_ENTRY(ifg_member)	 ifgm_next; /* [N] all members are chained */
+	struct ifnet		*ifgm_ifp;  /* [I] member interface */
 };
 
 struct ifg_list {
-	struct ifg_group	*ifgl_group;
-	TAILQ_ENTRY(ifg_list)	 ifgl_next;
+	struct ifg_group	*ifgl_group; /* [I] interface group */
+	TAILQ_ENTRY(ifg_list)	 ifgl_next;  /* [N] all groups are chained */
 };
 
 #define	IFNET_SLOWTIMO	1		/* granularity is 1 second */