[src/trunk]: src/sys/net Add debug helper function for interface addresses

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/db38aed1d7f0
branches:  trunk
changeset: 816336:db38aed1d7f0
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Fri Jul 01 05:15:40 2016 +0000

description:
Add debug helper function for interface addresses

It checks whether all addresses of an interface being destroyed
are freed (no reference remains) at the end of if_detach.

diffstat:

 sys/net/if.c |  70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 68 insertions(+), 2 deletions(-)

diffs (105 lines):

diff -r 106d83f0902a -r db38aed1d7f0 sys/net/if.c
--- a/sys/net/if.c      Thu Jun 30 20:39:54 2016 +0000
+++ b/sys/net/if.c      Fri Jul 01 05:15:40 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if.c,v 1.348 2016/06/28 02:36:54 ozaki-r Exp $ */
+/*     $NetBSD: if.c,v 1.349 2016/07/01 05:15:40 ozaki-r Exp $ */
 
 /*-
  * Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc.
@@ -90,7 +90,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.348 2016/06/28 02:36:54 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.349 2016/07/01 05:15:40 ozaki-r Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -1025,6 +1025,65 @@
        }
 }
 
+#ifdef IFAREF_DEBUG
+static struct ifaddr **ifa_list;
+static int ifa_list_size;
+
+/* Depends on only one if_attach runs at once */
+static void
+if_build_ifa_list(struct ifnet *ifp)
+{
+       struct ifaddr *ifa;
+       int i;
+
+       KASSERT(ifa_list == NULL);
+       KASSERT(ifa_list_size == 0);
+
+       IFADDR_FOREACH(ifa, ifp)
+               ifa_list_size++;
+
+       ifa_list = kmem_alloc(sizeof(*ifa) * ifa_list_size, KM_SLEEP);
+       if (ifa_list == NULL)
+               return;
+
+       i = 0;
+       IFADDR_FOREACH(ifa, ifp) {
+               ifa_list[i++] = ifa;
+               ifaref(ifa);
+       }
+}
+
+static void
+if_check_and_free_ifa_list(struct ifnet *ifp)
+{
+       int i;
+       struct ifaddr *ifa;
+
+       if (ifa_list == NULL)
+               return;
+
+       for (i = 0; i < ifa_list_size; i++) {
+               char buf[64];
+
+               ifa = ifa_list[i];
+               sockaddr_format(ifa->ifa_addr, buf, sizeof(buf));
+               if (ifa->ifa_refcnt > 1) {
+                       log(LOG_WARNING,
+                           "ifa(%s) still referenced (refcnt=%d)\n",
+                           buf, ifa->ifa_refcnt - 1);
+               } else
+                       log(LOG_DEBUG,
+                           "ifa(%s) not referenced (refcnt=%d)\n",
+                           buf, ifa->ifa_refcnt - 1);
+               ifafree(ifa);
+       }
+
+       kmem_free(ifa_list, sizeof(*ifa) * ifa_list_size);
+       ifa_list = NULL;
+       ifa_list_size = 0;
+}
+#endif
+
 /*
  * Detach an interface from the list of "active" interfaces,
  * freeing any resources as we go along.
@@ -1045,6 +1104,9 @@
        int s, i, family, purged;
        uint64_t xc;
 
+#ifdef IFAREF_DEBUG
+       if_build_ifa_list(ifp);
+#endif
        /*
         * XXX It's kind of lame that we have to have the
         * XXX socket structure...
@@ -1245,6 +1307,10 @@
        }
 
        splx(s);
+
+#ifdef IFAREF_DEBUG
+       if_check_and_free_ifa_list(ifp);
+#endif
 }
 
 static void