[src/trunk]: src/sys/dev/ic actually check the return value from m_gethdr() a...

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

details:   https://anonhg.NetBSD.org/src/rev/3e48aac76805
branches:  trunk
changeset: 338863:3e48aac76805
user:      macallan <macallan%NetBSD.org@localhost>
date:      Fri Jun 12 17:24:02 2015 +0000

description:
actually check the return value from m_gethdr() and deal with errors
now we no longer segfault in dme_allocate_buffer()

diffstat:

 sys/dev/ic/dm9000.c |  36 +++++++++++++++++++++++++++++++++---
 1 files changed, 33 insertions(+), 3 deletions(-)

diffs (71 lines):

diff -r 1c7486d1ef7c -r 3e48aac76805 sys/dev/ic/dm9000.c
--- a/sys/dev/ic/dm9000.c       Fri Jun 12 17:02:30 2015 +0000
+++ b/sys/dev/ic/dm9000.c       Fri Jun 12 17:24:02 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: dm9000.c,v 1.7 2015/03/14 13:45:43 macallan Exp $      */
+/*     $NetBSD: dm9000.c,v 1.8 2015/06/12 17:24:02 macallan Exp $      */
 
 /*
  * Copyright (c) 2009 Paul Fleischer
@@ -809,8 +809,12 @@
                                          sc->dme_io, DM9000_MRCMD);
 
                        rx_status = sc->sc_pkt_read(sc, ifp, &m);
-
-                       if (rx_status & (DM9000_RSR_CE | DM9000_RSR_PLE)) {
+                       if (m == NULL) {
+                               /* failed to allocate a receive buffer */
+                               ifp->if_ierrors++;
+                               RX_DPRINTF(("dme_receive: "
+                                       "Error allocating buffer\n"));
+                       } else if (rx_status & (DM9000_RSR_CE | DM9000_RSR_PLE)) {
                                /* Error while receiving the packet,
                                 * discard it and keep track of counters
                                 */
@@ -1082,6 +1086,18 @@
 
 
        m = dme_alloc_receive_buffer(ifp, frame_length);
+       if (m == NULL) {
+               /*
+                * didn't get a receive buffer, so we read the rest of the
+                * packet, throw it away and return an error
+                */
+               for (i = 0; i < frame_length; i += 2 ) {
+                       data = bus_space_read_2(sc->sc_iot,
+                                       sc->sc_ioh, sc->dme_data);
+               }
+               *outBuf = NULL;
+               return 0;
+       }
 
        buf = mtod(m, uint16_t*);
 
@@ -1163,6 +1179,18 @@
 
 
        m = dme_alloc_receive_buffer(ifp, frame_length);
+       if (m == NULL) {
+               /*
+                * didn't get a receive buffer, so we read the rest of the
+                * packet, throw it away and return an error
+                */
+               for (i = 0; i < frame_length; i++ ) {
+                       data = bus_space_read_2(sc->sc_iot,
+                                       sc->sc_ioh, sc->dme_data);
+               }
+               *outBuf = NULL;
+               return 0;
+       }
 
        buf = mtod(m, uint8_t *);
 
@@ -1190,6 +1218,8 @@
        int pad;
 
        MGETHDR(m, M_DONTWAIT, MT_DATA);
+       if (m == NULL) return NULL;
+
        m->m_pkthdr.rcvif = ifp;
        /* Ensure that we always allocate an even number of
         * bytes in order to avoid writing beyond the buffer