[src/trunk]: src/sys/netinet Send an arp request before the arp entry times o...

[ragge <ragge%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0aa93140796c
branches:  trunk
changeset: 566129:0aa93140796c
user:      ragge <ragge%NetBSD.org@localhost>
date:      Wed Apr 28 14:09:36 2004 +0000

description:
Send an arp request before the arp entry times out if the entry is active,
to avoid deleting active entries.
Add sysctl support to tune the default arp timeout values.

diffstat:

 sys/netinet/if_arp.c |  68 +++++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 65 insertions(+), 3 deletions(-)

diffs (116 lines):

diff -r 5f4b218c340b -r 0aa93140796c sys/netinet/if_arp.c
--- a/sys/netinet/if_arp.c      Wed Apr 28 12:38:19 2004 +0000
+++ b/sys/netinet/if_arp.c      Wed Apr 28 14:09:36 2004 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_arp.c,v 1.96 2004/04/22 01:01:40 matt Exp $ */
+/*     $NetBSD: if_arp.c,v 1.97 2004/04/28 14:09:36 ragge Exp $        */
 
 /*-
  * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
@@ -75,7 +75,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.96 2004/04/22 01:01:40 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.97 2004/04/28 14:09:36 ragge Exp $");
 
 #include "opt_ddb.h"
 #include "opt_inet.h"
@@ -98,6 +98,7 @@
 #include <sys/proc.h>
 #include <sys/protosw.h>
 #include <sys/domain.h>
+#include <sys/sysctl.h>
 
 #include <net/ethertypes.h>
 #include <net/if.h>
@@ -137,7 +138,9 @@
 int    arpt_prune = (5*60*1);  /* walk list every 5 minutes */
 int    arpt_keep = (20*60);    /* once resolved, good for 20 more minutes */
 int    arpt_down = 20;         /* once declared down, don't send for 20 secs */
+int    arpt_refresh = (5*60);  /* time left before refreshing */
 #define        rt_expire rt_rmx.rmx_expire
+#define        rt_pksent rt_rmx.rmx_pksent
 
 extern struct domain arpdomain;
 
@@ -356,7 +359,19 @@
                struct rtentry *rt = la->la_rt;
 
                nla = LIST_NEXT(la, la_list);
-               if (rt->rt_expire && rt->rt_expire <= time.tv_sec)
+               if (rt->rt_expire == 0)
+                       continue;
+               if ((rt->rt_expire - time.tv_sec) < arpt_refresh &&
+                   rt->rt_pksent > (time.tv_sec - arpt_keep)) {
+                       /*
+                        * If the entry has been used during since last
+                        * refresh, try to renew it before deleting.
+                        */
+                       arprequest(rt->rt_ifp,
+                           &SIN(rt->rt_ifa->ifa_addr)->sin_addr,
+                           &SIN(rt_key(rt))->sin_addr,
+                           LLADDR(rt->rt_ifp->if_sadl));
+               } else if (rt->rt_expire <= time.tv_sec)
                        arptfree(la); /* timer has expired; clear */
        }
 
@@ -698,6 +713,7 @@
            sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) {
                bcopy(LLADDR(sdl), desten,
                    min(sdl->sdl_alen, ifp->if_addrlen));
+               rt->rt_pksent = time.tv_sec; /* Time for last pkt sent */
                return 1;
        }
        /*
@@ -1490,4 +1506,50 @@
        return;
 }
 #endif
+
+SYSCTL_SETUP(sysctl_net_inet_arp_setup, "sysctl net.inet.arp subtree setup")
+{
+       struct sysctlnode *node;
+
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT,
+                       CTLTYPE_NODE, "net", NULL,
+                       NULL, 0, NULL, 0,
+                       CTL_NET, CTL_EOL);
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT,
+                       CTLTYPE_NODE, "inet", NULL,
+                       NULL, 0, NULL, 0,
+                       CTL_NET, PF_INET, CTL_EOL);
+       sysctl_createv(clog, 0, NULL, &node,
+                       CTLFLAG_PERMANENT,
+                       CTLTYPE_NODE, "arp", NULL,
+                       NULL, 0, NULL, 0,
+                       CTL_NET, PF_INET, CTL_CREATE, CTL_EOL);
+
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+                       CTLTYPE_INT, "prune", NULL,
+                       NULL, 0, &arpt_prune, 0,
+                       CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
+
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+                       CTLTYPE_INT, "keep", NULL,
+                       NULL, 0, &arpt_keep, 0,
+                       CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
+
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+                       CTLTYPE_INT, "down", NULL,
+                       NULL, 0, &arpt_down, 0,
+                       CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
+
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+                       CTLTYPE_INT, "refresh", NULL,
+                       NULL, 0, &arpt_refresh, 0,
+                       CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
+}
+
 #endif /* INET */