[src/trunk]: src/sys/net Replace panic with rate-limited LOG_ERR message when...

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

details:   https://anonhg.NetBSD.org/src/rev/33ab30195f3d
branches:  trunk
changeset: 446706:33ab30195f3d
user:      rin <rin%NetBSD.org@localhost>
date:      Sat Dec 15 07:29:44 2018 +0000

description:
Replace panic with rate-limited LOG_ERR message when we encounter
invalid ether frame with non-zero csum flags.

Requested by thorpej.

diffstat:

 sys/net/ether_sw_offload.c |  24 ++++++++++++++++++++----
 1 files changed, 20 insertions(+), 4 deletions(-)

diffs (70 lines):

diff -r f57a2fd53325 -r 33ab30195f3d sys/net/ether_sw_offload.c
--- a/sys/net/ether_sw_offload.c        Sat Dec 15 05:40:10 2018 +0000
+++ b/sys/net/ether_sw_offload.c        Sat Dec 15 07:29:44 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ether_sw_offload.c,v 1.4 2018/12/13 20:54:50 rin Exp $ */
+/*     $NetBSD: ether_sw_offload.c,v 1.5 2018/12/15 07:29:44 rin Exp $ */
 
 /*
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -34,11 +34,13 @@
 #endif
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ether_sw_offload.c,v 1.4 2018/12/13 20:54:50 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ether_sw_offload.c,v 1.5 2018/12/15 07:29:44 rin Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
 #include <sys/mbuf.h>
+#include <sys/syslog.h>
+#include <sys/time.h>
 
 #include <net/if.h>
 #include <net/if_ether.h>
@@ -57,6 +59,15 @@
 #endif
 
 /*
+ * Limit error messages at most once per 10 seconds.
+ */
+static const struct timeval eso_err_interval = {
+       .tv_sec = 10,
+       .tv_usec = 0,
+};
+static struct timeval eso_err_lasttime;
+
+/*
  * Handle TX offload in software. For TSO, split the packet into
  * chanks with payloads of size MSS. For chekcsum offload, update
  * required checksum fields. The results are more than one packet
@@ -68,6 +79,7 @@
 {
        struct ether_header *ep;
        int flags, ehlen;
+       uint16_t type;
 #ifdef INET6
        bool v6;
 #else
@@ -90,7 +102,7 @@
                        return NULL;
        }
        ep = mtod(m, struct ether_header *);
-       switch (ntohs(ep->ether_type)) {
+       switch (type = ntohs(ep->ether_type)) {
        case ETHERTYPE_IP:
        case ETHERTYPE_IPV6:
                ehlen = ETHER_HDR_LEN;
@@ -99,7 +111,11 @@
                ehlen = ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
                break;
        default:
-               panic("%s: unexpected frame type", __func__);
+               if (ratecheck(&eso_err_lasttime, &eso_err_interval))
+                       log(LOG_ERR, "%s: %s: dropping invalid frame "
+                           "type 0x%04hx csum_flags 0x%08x\n",
+                           __func__, ifp->if_xname, type, flags);
+               goto quit;
        }
        KASSERT(m->m_pkthdr.len >= ehlen);