[src/trunk]: src/sys Add init function for mbuf.

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

details:   https://anonhg.NetBSD.org/src/rev/81f811e8bc58
branches:  trunk
changeset: 814927:81f811e8bc58
user:      knakahara <knakahara%NetBSD.org@localhost>
date:      Wed Apr 20 08:50:43 2016 +0000

description:
Add init function for mbuf.

some functions use mbuf as stack variable instead of allocating by m_get().
They should use this function(s) to prevent access to uninitialized fields.

Currently, the mbuf stack allocating functions are the following.
    + sys/dev/ic/bwi.c
      - bwi_rxeof()
      - bwi_encap()
    + sys/dev/ic/dp8390.c
      - dp8390_ipkdb_send()
    + sys/dev/pci/if_txp.c
      - txp_download_fw_section()
    + sys/dev/ppbus/if_plip.c
      - lptap()
    + sys/net/bpf.c
      - _pf_mtap2()
      - _pf_mtap_af()
      - _pf_mtap_sl_out()
    + sys/netisdn/i4b_ipr.c
      - ipr_rx_data_rdy()
      - ipr_tx_queue_empty()

Reviewed by kre@n.o and christos@n.o, thanks.

diffstat:

 sys/kern/uipc_mbuf.c |  22 +++++-----------------
 sys/sys/mbuf.h       |  34 +++++++++++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 18 deletions(-)

diffs (98 lines):

diff -r 688487304bc6 -r 81f811e8bc58 sys/kern/uipc_mbuf.c
--- a/sys/kern/uipc_mbuf.c      Wed Apr 20 06:51:03 2016 +0000
+++ b/sys/kern/uipc_mbuf.c      Wed Apr 20 08:50:43 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uipc_mbuf.c,v 1.163 2015/08/24 22:21:26 pooka Exp $    */
+/*     $NetBSD: uipc_mbuf.c,v 1.164 2016/04/20 08:50:43 knakahara Exp $        */
 
 /*-
  * Copyright (c) 1999, 2001 The NetBSD Foundation, Inc.
@@ -62,7 +62,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.163 2015/08/24 22:21:26 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uipc_mbuf.c,v 1.164 2016/04/20 08:50:43 knakahara Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_mbuftrace.h"
@@ -583,14 +583,8 @@
                return NULL;
 
        mbstat_type_add(type, 1);
-       mowner_init(m, type);
-       m->m_ext_ref = m;
-       m->m_type = type;
-       m->m_len = 0;
-       m->m_next = NULL;
-       m->m_nextpkt = NULL;
-       m->m_data = m->m_dat;
-       m->m_flags = 0;
+
+       m_hdr_init(m, type, NULL, m->m_dat, 0);
 
        return m;
 }
@@ -604,13 +598,7 @@
        if (m == NULL)
                return NULL;
 
-       m->m_data = m->m_pktdat;
-       m->m_flags = M_PKTHDR;
-       m->m_pkthdr.rcvif = NULL;
-       m->m_pkthdr.len = 0;
-       m->m_pkthdr.csum_flags = 0;
-       m->m_pkthdr.csum_data = 0;
-       SLIST_INIT(&m->m_pkthdr.tags);
+       m_pkthdr_init(m);
 
        return m;
 }
diff -r 688487304bc6 -r 81f811e8bc58 sys/sys/mbuf.h
--- a/sys/sys/mbuf.h    Wed Apr 20 06:51:03 2016 +0000
+++ b/sys/sys/mbuf.h    Wed Apr 20 08:50:43 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mbuf.h,v 1.159 2015/10/13 21:28:34 rjs Exp $   */
+/*     $NetBSD: mbuf.h,v 1.160 2016/04/20 08:50:43 knakahara Exp $     */
 
 /*-
  * Copyright (c) 1996, 1997, 1999, 2001, 2007 The NetBSD Foundation, Inc.
@@ -934,6 +934,38 @@
        return pktlen;
 }
 
+static __inline void
+m_hdr_init(struct mbuf *m, short type, struct mbuf *next, char *data, int len)
+{
+
+       KASSERT(m != NULL);
+
+       mowner_init(m, type);
+       m->m_ext_ref = m; /* default */
+       m->m_type = type;
+       m->m_len = len;
+       m->m_next = next;
+       m->m_nextpkt = NULL; /* default */
+       m->m_data = data;
+       m->m_flags = 0; /* default */
+}
+
+static __inline void
+m_pkthdr_init(struct mbuf *m)
+{
+
+       KASSERT(m != NULL);
+
+       m->m_data = m->m_pktdat;
+       m->m_flags = M_PKTHDR;
+
+       m->m_pkthdr.rcvif = NULL;
+       m->m_pkthdr.len = 0;
+       m->m_pkthdr.csum_flags = 0;
+       m->m_pkthdr.csum_data = 0;
+       SLIST_INIT(&m->m_pkthdr.tags);
+}
+
 void m_print(const struct mbuf *, const char *, void (*)(const char *, ...)
     __printflike(1, 2));