[src/trunk]: src/sys/net ether: count dropped packets on input

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

details:   https://anonhg.NetBSD.org/src/rev/294c36b61f0a
branches:  trunk
changeset: 937853:294c36b61f0a
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Fri Aug 28 06:27:16 2020 +0000

description:
ether: count dropped packets on input

diffstat:

 sys/net/if_ethersubr.c |  69 +++++++++++++++++++++----------------------------
 1 files changed, 30 insertions(+), 39 deletions(-)

diffs (184 lines):

diff -r c10a366b8785 -r 294c36b61f0a sys/net/if_ethersubr.c
--- a/sys/net/if_ethersubr.c    Fri Aug 28 06:25:52 2020 +0000
+++ b/sys/net/if_ethersubr.c    Fri Aug 28 06:27:16 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_ethersubr.c,v 1.286 2020/08/28 06:25:52 ozaki-r Exp $       */
+/*     $NetBSD: if_ethersubr.c,v 1.287 2020/08/28 06:27:16 ozaki-r Exp $       */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_ethersubr.c,v 1.286 2020/08/28 06:25:52 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_ethersubr.c,v 1.287 2020/08/28 06:27:16 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -620,6 +620,7 @@
 
 drop:
        m_freem(m);
+       if_statinc(ifp, if_ierrors); /* XXX should have a dedicated counter? */
        return;
 }
 #endif /* defined (LLC) || defined (NETATALK) */
@@ -644,14 +645,12 @@
        KASSERT(!cpu_intr_p());
        KASSERT((m->m_flags & M_PKTHDR) != 0);
 
-       if ((ifp->if_flags & IFF_UP) == 0) {
-               m_freem(m);
-               return;
-       }
+       if ((ifp->if_flags & IFF_UP) == 0)
+               goto drop;
        if (m->m_len < sizeof(*eh)) {
                m = m_pullup(m, sizeof(*eh));
                if (m == NULL)
-                       return;
+                       goto dropped;
        }
 
 #ifdef MBUFTRACE
@@ -682,9 +681,7 @@
                }
                mutex_exit(&bigpktpps_lock);
 #endif
-               if_statinc(ifp, if_iqdrops);
-               m_freem(m);
-               return;
+               goto drop;
        }
 
        if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
@@ -695,8 +692,7 @@
                if ((ifp->if_flags & IFF_SIMPLEX) == 0 &&
                    memcmp(CLLADDR(ifp->if_sadl), eh->ether_shost,
                    ETHER_ADDR_LEN) == 0) {
-                       m_freem(m);
-                       return;
+                       goto drop;
                }
 
                if (memcmp(etherbroadcastaddr,
@@ -766,10 +762,10 @@
                 * or drop the packet.
                 */
                vlan_input(ifp, m);
+               return;
 #else
-               m_freem(m);
+               goto drop;
 #endif
-               return;
        }
 
        /*
@@ -800,13 +796,12 @@
                 * vlan_input() will either recursively call ether_input()
                 * or drop the packet.
                 */
-               if (ec->ec_nvlans != 0)
+               if (ec->ec_nvlans != 0) {
                        vlan_input(ifp, m);
-               else
+                       return;
+               } else
 #endif
-                       m_freem(m);
-
-               return;
+                       goto drop;
        }
 
 #if NPPPOE > 0
@@ -822,10 +817,8 @@
        case ETHERTYPE_SLOWPROTOCOLS: {
                uint8_t subtype;
 
-               if (m->m_pkthdr.len < sizeof(*eh) + sizeof(subtype)) {
-                       m_freem(m);
-                       return;
-               }
+               if (m->m_pkthdr.len < sizeof(*eh) + sizeof(subtype))
+                       goto drop;
 
                m_copydata(m, sizeof(*eh), sizeof(subtype), &subtype);
                switch (subtype) {
@@ -848,8 +841,7 @@
                default:
                        if (subtype == 0 || subtype > 10) {
                                /* illegal value */
-                               m_freem(m);
-                               return;
+                               goto drop;
                        }
                        /* unknown subtype */
                        break;
@@ -857,10 +849,8 @@
        }
        /* FALLTHROUGH */
        default:
-               if (m->m_flags & M_PROMISC) {
-                       m_freem(m);
-                       return;
-               }
+               if (m->m_flags & M_PROMISC)
+                       goto drop;
        }
 
        /* If the CRC is still on the packet, trim it off. */
@@ -876,8 +866,7 @@
                ether_input_llc(ifp, m, eh);
                return;
 #else
-               m_freem(m);
-               return;
+               goto drop;
 #endif
        }
 
@@ -906,10 +895,8 @@
 
 #ifdef INET6
        case ETHERTYPE_IPV6:
-               if (__predict_false(!in6_present)) {
-                       m_freem(m);
-                       return;
-               }
+               if (__predict_false(!in6_present))
+                       goto drop;
 #ifdef GATEWAY
                if (ip6flow_fastforward(&m))
                        return;
@@ -937,8 +924,7 @@
 #endif
 
        default:
-               m_freem(m);
-               return;
+               goto drop;
        }
 
        if (__predict_true(pktq)) {
@@ -955,11 +941,16 @@
 
        if (__predict_false(!inq)) {
                /* Should not happen. */
-               m_freem(m);
-               return;
+               goto drop;
        }
 
        IFQ_ENQUEUE_ISR(inq, m, isr);
+       return;
+
+drop:
+       m_freem(m);
+dropped:
+       if_statinc(ifp, if_ierrors); /* XXX should have a dedicated counter? */
 }
 
 /*