ARP has a sysctl to show the number of packets waiting for an arp

response.  Implement analog sysctl net.inet6.icmp6.nd6_queued for
ND6 to reduce places where mbufs can hide within the kernel.
Atomic operations operate on unsigned int.  Make the type of total
hold queue length consistent.
Use atomic load to read the value for the sysctl.  This clarifies
why no lock around sysctl_rdint() is needed.
OK mvs@ kn@

diff --git a/sys/netinet/icmp6.h b/sys/netinet/icmp6.h
index ef7df8d..210c619 100644 (file)
--- a/sys/netinet/icmp6.h
+++ b/sys/netinet/icmp6.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: icmp6.h,v 1.51 2021/01/11 13:28:53 bluhm Exp $        */
+/*     $OpenBSD: icmp6.h,v 1.52 2023/04/05 21:51:47 bluhm Exp $        */
 /*     $KAME: icmp6.h,v 1.84 2003/04/23 10:26:51 itojun Exp $  */
 
 /*
@@ -504,7 +504,8 @@ struct icmp6stat {
 #define ICMPV6CTL_REDIRTIMEOUT 3       /* redirect cache time */
 #define ICMPV6CTL_ND6_DELAY    8
 #define ICMPV6CTL_ND6_UMAXTRIES        9
-#define ICMPV6CTL_ND6_MMAXTRIES                10
+#define ICMPV6CTL_ND6_MMAXTRIES        10
+#define ICMPV6CTL_ND6_QUEUED   11
 #define ICMPV6CTL_NODEINFO     13
 #define ICMPV6CTL_ERRPPSLIMIT  14      /* ICMPv6 error pps limitation */
 #define ICMPV6CTL_ND6_MAXNUDHINT       15
@@ -525,7 +526,7 @@ struct icmp6stat {
        { "nd6_delay", CTLTYPE_INT }, \
        { "nd6_umaxtries", CTLTYPE_INT }, \
        { "nd6_mmaxtries", CTLTYPE_INT }, \
-       { 0, 0 }, \
+       { "nd6_queued", CTLTYPE_INT }, \
        { 0, 0 }, \
        { 0, 0 }, \
        { "errppslimit", CTLTYPE_INT }, \

diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index b1268d3..46aa3c2 100644 (file)
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_ether.c,v 1.259 2023/04/05 19:35:23 bluhm Exp $    */
+/*     $OpenBSD: if_ether.c,v 1.260 2023/04/05 21:51:47 bluhm Exp $    */
 /*     $NetBSD: if_ether.c,v 1.31 1996/05/11 12:59:58 mycroft Exp $    */
 
 /*
@@ -109,7 +109,7 @@ LIST_HEAD(, llinfo_arp) arp_list =
     LIST_HEAD_INITIALIZER(arp_list);   /* [mN] list of llinfo_arp structures */
 struct pool arp_pool;          /* [I] pool for llinfo_arp structures */
 int    arp_maxtries = 5;       /* [I] arp requests before set to rejected */
-int    la_hold_total;          /* [a] packets currently in the arp queue */
+unsigned int   la_hold_total;  /* [a] packets currently in the arp queue */
 
 #ifdef NFSCLIENT
 /* revarp state */

diff --git a/sys/netinet/ip_input.c b/sys/netinet/ip_input.c
index 07dde28..42c1c72 100644 (file)
--- a/sys/netinet/ip_input.c
+++ b/sys/netinet/ip_input.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ip_input.c,v 1.382 2023/03/08 23:17:02 bluhm Exp $    */
+/*     $OpenBSD: ip_input.c,v 1.383 2023/04/05 21:51:47 bluhm Exp $    */
 /*     $NetBSD: ip_input.c,v 1.30 1996/03/16 23:53:58 christos Exp $   */
 
 /*
@@ -1698,7 +1698,8 @@ ip_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
                return (sysctl_niq(name + 1, namelen - 1,
                    oldp, oldlenp, newp, newlen, &arpinq));
        case IPCTL_ARPQUEUED:
-               return (sysctl_rdint(oldp, oldlenp, newp, la_hold_total));
+               return (sysctl_rdint(oldp, oldlenp, newp,
+                   atomic_load_int(&la_hold_total)));
        case IPCTL_STATS:
                return (ip_sysctl_ipstat(oldp, oldlenp, newp));
 #ifdef MROUTING

diff --git a/sys/netinet/ip_var.h b/sys/netinet/ip_var.h
index e4ba27b..b93b27c 100644 (file)
--- a/sys/netinet/ip_var.h
+++ b/sys/netinet/ip_var.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ip_var.h,v 1.108 2022/11/17 18:05:43 mvs Exp $        */
+/*     $OpenBSD: ip_var.h,v 1.109 2023/04/05 21:51:47 bluhm Exp $      */
 /*     $NetBSD: ip_var.h,v 1.16 1996/02/13 23:43:20 christos Exp $     */
 
 /*
@@ -217,7 +217,7 @@ extern int ipforwarding;            /* enable IP forwarding */
 extern int ipmforwarding;              /* enable multicast forwarding */
 #endif
 extern int ipmultipath;                        /* enable multipath routing */
-extern int la_hold_total;
+extern unsigned int la_hold_total;
 
 extern const struct pr_usrreqs rip_usrreqs;
 

diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index a1174a1..9173b52 100644 (file)
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: icmp6.c,v 1.247 2022/12/10 23:45:51 kn Exp $  */
+/*     $OpenBSD: icmp6.c,v 1.248 2023/04/05 21:51:47 bluhm Exp $       */
 /*     $KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 jinmei Exp $ */
 
 /*
@@ -1902,6 +1902,11 @@ icmp6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
                error = icmp6_sysctl_icmp6stat(oldp, oldlenp, newp);
                break;
 
+       case ICMPV6CTL_ND6_QUEUED:
+               error = sysctl_rdint(oldp, oldlenp, newp,
+                   atomic_load_int(&ln_hold_total));
+               break;
+
        default:
                NET_LOCK();
                error = sysctl_bounded_arr(icmpv6ctl_vars,

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index c937040..591a468 100644 (file)
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: nd6.c,v 1.270 2023/04/05 19:35:23 bluhm Exp $ */
+/*     $OpenBSD: nd6.c,v 1.271 2023/04/05 21:51:47 bluhm Exp $ */
 /*     $KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $   */
 
 /*
@@ -87,7 +87,7 @@ int nd6_debug = 0;
 TAILQ_HEAD(llinfo_nd6_head, llinfo_nd6) nd6_list;
 struct pool nd6_pool;          /* pool for llinfo_nd6 structures */
 int    nd6_inuse;
-int    ln_hold_total;          /* [a] packets currently in the nd6 queue */
+unsigned int   ln_hold_total;  /* [a] packets currently in the nd6 queue */
 
 void nd6_timer(void *);
 void nd6_slowtimo(void *);

diff --git a/sys/netinet6/nd6.h b/sys/netinet6/nd6.h
index b3c2be9..8e6a722 100644 (file)
--- a/sys/netinet6/nd6.h
+++ b/sys/netinet6/nd6.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: nd6.h,v 1.96 2023/04/05 19:35:23 bluhm Exp $  */
+/*     $OpenBSD: nd6.h,v 1.97 2023/04/05 21:51:47 bluhm Exp $  */
 /*     $KAME: nd6.h,v 1.95 2002/06/08 11:31:06 itojun Exp $    */
 
 /*
@@ -91,7 +91,7 @@ struct        llinfo_nd6 {
 #define LN_HOLD_QUEUE 10
 #define LN_HOLD_TOTAL 100
 
-extern int ln_hold_total;
+extern unsigned int ln_hold_total;
 
 #define ND6_LLINFO_PERMANENT(n)        ((n)->ln_rt->rt_expire == 0)