[src/trunk]: src/sys/netinet Add 3 logging sysctls for arp from freebsd:

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

details:   https://anonhg.NetBSD.org/src/rev/83de0c0097e0
branches:  trunk
changeset: 768766:83de0c0097e0
user:      christos <christos%NetBSD.org@localhost>
date:      Sat Aug 27 09:05:54 2011 +0000

description:
Add 3 logging sysctls for arp from freebsd:

1. log_movements: do you want to log the arp overwritten message or not?
2. log_wrong_iface: do you want to log when an arp arrives at the wrong
   interface?
3. log_permanent_modify: do you want to log when an arp message attempts
   to overwrite a static entry?

I did not call the sysctls log_arp like FreeBSD does, because we already
have an arp sysctl level. The default is on for all three of them.

diffstat:

 sys/netinet/if_arp.c |  52 +++++++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 43 insertions(+), 9 deletions(-)

diffs (120 lines):

diff -r 1e47f6ea83bb -r 83de0c0097e0 sys/netinet/if_arp.c
--- a/sys/netinet/if_arp.c      Fri Aug 26 21:22:07 2011 +0000
+++ b/sys/netinet/if_arp.c      Sat Aug 27 09:05:54 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_arp.c,v 1.151 2011/05/03 16:00:29 dyoung Exp $      */
+/*     $NetBSD: if_arp.c,v 1.152 2011/08/27 09:05:54 christos Exp $    */
 
 /*-
  * Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.151 2011/05/03 16:00:29 dyoung Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.152 2011/08/27 09:05:54 christos Exp $");
 
 #include "opt_ddb.h"
 #include "opt_inet.h"
@@ -191,6 +191,10 @@
 
 static int arp_drainwanted;
 
+static int log_movements = 1;
+static int log_permanent_modify = 1;
+static int log_wrong_iface = 1;
+
 /*
  * this should be elsewhere.
  */
@@ -1085,6 +1089,8 @@
                    memcmp(ar_sha(ah), CLLADDR(sdl), sdl->sdl_alen)) {
                        if (rt->rt_flags & RTF_STATIC) {
                                ARP_STATINC(ARP_STAT_RCVOVERPERM);
+                               if (!log_permanent_modify)
+                                       goto out;
                                log(LOG_INFO,
                                    "%s tried to overwrite permanent arp info"
                                    " for %s\n",
@@ -1093,6 +1099,8 @@
                                goto out;
                        } else if (rt->rt_ifp != ifp) {
                                ARP_STATINC(ARP_STAT_RCVOVERINT);
+                               if (!log_wrong_iface)
+                                       goto out;
                                log(LOG_INFO,
                                    "%s on %s tried to overwrite "
                                    "arp info for %s on %s\n",
@@ -1102,10 +1110,12 @@
                                    goto out;
                        } else {
                                ARP_STATINC(ARP_STAT_RCVOVER);
-                               log(LOG_INFO,
-                                   "arp info overwritten for %s by %s\n",
-                                   in_fmtaddr(isaddr),
-                                   lla_snprintf(ar_sha(ah), ah->ar_hln));
+                               if (log_movements)
+                                       log(LOG_INFO, "arp info overwritten "
+                                           "for %s by %s\n",
+                                           in_fmtaddr(isaddr),
+                                           lla_snprintf(ar_sha(ah),
+                                           ah->ar_hln));
                        }
                }
                /*
@@ -1641,21 +1651,21 @@
        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                        CTLTYPE_INT, "prune",
-                       SYSCTL_DESCR("ARP cache pruning interval"),
+                       SYSCTL_DESCR("ARP cache pruning interval in seconds"),
                        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",
-                       SYSCTL_DESCR("Valid ARP entry lifetime"),
+                       SYSCTL_DESCR("Valid ARP entry lifetime in seconds"),
                        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",
-                       SYSCTL_DESCR("Failed ARP entry lifetime"),
+                       SYSCTL_DESCR("Failed ARP entry lifetime in seconds"),
                        NULL, 0, &arpt_down, 0,
                        CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
 
@@ -1672,6 +1682,30 @@
                        SYSCTL_DESCR("ARP statistics"),
                        sysctl_net_inet_arp_stats, 0, NULL, 0,
                        CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
+
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+                       CTLTYPE_INT, "log_movements",
+                       SYSCTL_DESCR("log ARP replies from MACs different than"
+                           " the one in the cache"),
+                       NULL, 0, &log_movements, 0,
+                       CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
+
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+                       CTLTYPE_INT, "log_permanent_modify",
+                       SYSCTL_DESCR("log ARP replies from MACs different than"
+                           " the one in the permanent arp entry"),
+                       NULL, 0, &log_permanent_modify, 0,
+                       CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
+
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+                       CTLTYPE_INT, "log_wrong_iface",
+                       SYSCTL_DESCR("log ARP packets arriving on the wrong"
+                           " interface"),
+                       NULL, 0, &log_wrong_iface, 0,
+                       CTL_NET,PF_INET, node->sysctl_num, CTL_CREATE, CTL_EOL);
 }
 
 #endif /* INET */