[src/trunk]: src/sys/netipsec Provide a function to call MGETHDR and MCLGET

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

details:   https://anonhg.NetBSD.org/src/rev/7ccd1885c4fc
branches:  trunk
changeset: 827976:7ccd1885c4fc
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Tue Nov 21 06:49:56 2017 +0000

description:
Provide a function to call MGETHDR and MCLGET

The change fixes two usages of MGETHDR that don't check whether a mbuf is really
allocated before passing it to MCLGET.

diffstat:

 sys/netipsec/key.c |  66 +++++++++++++++++++----------------------------------
 1 files changed, 24 insertions(+), 42 deletions(-)

diffs (129 lines):

diff -r 3449540caf9e -r 7ccd1885c4fc sys/netipsec/key.c
--- a/sys/netipsec/key.c        Tue Nov 21 06:35:22 2017 +0000
+++ b/sys/netipsec/key.c        Tue Nov 21 06:49:56 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: key.c,v 1.235 2017/11/08 10:35:30 ozaki-r Exp $        */
+/*     $NetBSD: key.c,v 1.236 2017/11/21 06:49:56 ozaki-r Exp $        */
 /*     $FreeBSD: src/sys/netipsec/key.c,v 1.3.2.3 2004/02/14 22:23:23 bms Exp $        */
 /*     $KAME: key.c,v 1.191 2001/06/27 10:46:49 sakane Exp $   */
 
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: key.c,v 1.235 2017/11/08 10:35:30 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: key.c,v 1.236 2017/11/21 06:49:56 ozaki-r Exp $");
 
 /*
  * This code is referred to RFC 2367
@@ -788,6 +788,7 @@
 static void key_sa_chgstate (struct secasvar *, u_int8_t);
 
 static struct mbuf *key_alloc_mbuf (int);
+static struct mbuf *key_alloc_mbuf_simple(int, int);
 
 static void key_timehandler(void *);
 static void key_timehandler_work(struct work *, void *);
@@ -2416,6 +2417,22 @@
     }
 }
 
+static struct mbuf *
+key_alloc_mbuf_simple(int len, int mflag)
+{
+       struct mbuf *n;
+
+       MGETHDR(n, mflag, MT_DATA);
+       if (n && len > MHLEN) {
+               MCLGET(n, mflag);
+               if ((n->m_flags & M_EXT) == 0) {
+                       m_freem(n);
+                       n = NULL;
+               }
+       }
+       return n;
+}
+
 /*
  * SADB_SPDDELETE2 processing
  * receive
@@ -2465,14 +2482,7 @@
        /* create new sadb_msg to reply. */
        len = PFKEY_ALIGN8(sizeof(struct sadb_msg));
 
-       MGETHDR(n, M_DONTWAIT, MT_DATA);
-       if (n && len > MHLEN) {
-               MCLGET(n, M_DONTWAIT);
-               if ((n->m_flags & M_EXT) == 0) {
-                       m_freem(n);
-                       n = NULL;
-               }
-       }
+       n = key_alloc_mbuf_simple(len, M_DONTWAIT);
        if (!n)
                return key_senderror(so, m, ENOBUFS);
 
@@ -4072,14 +4082,7 @@
 
        len = PFKEY_ALIGN8(sizeof(struct sadb_msg));
 
-       MGETHDR(m, M_DONTWAIT, MT_DATA);
-       if (m && len > MHLEN) {
-               MCLGET(m, M_DONTWAIT);
-               if ((m->m_flags & M_EXT) == 0) {
-                       m_freem(m);
-                       m = NULL;
-               }
-       }
+       m = key_alloc_mbuf_simple(len, M_DONTWAIT);
        if (!m)
                return NULL;
        m->m_pkthdr.len = m->m_len = len;
@@ -5257,14 +5260,7 @@
        len = PFKEY_ALIGN8(sizeof(struct sadb_msg)) +
            PFKEY_ALIGN8(sizeof(struct sadb_sa));
 
-       MGETHDR(n, M_DONTWAIT, MT_DATA);
-       if (len > MHLEN) {
-               MCLGET(n, M_DONTWAIT);
-               if ((n->m_flags & M_EXT) == 0) {
-                       m_freem(n);
-                       n = NULL;
-               }
-       }
+       n = key_alloc_mbuf_simple(len, M_DONTWAIT);
        if (!n)
                return key_senderror(so, m, ENOBUFS);
 
@@ -7105,14 +7101,7 @@
        if (len > MCLBYTES)
                return key_senderror(so, m, ENOBUFS);
 
-       MGETHDR(n, M_DONTWAIT, MT_DATA);
-       if (len > MHLEN) {
-               MCLGET(n, M_DONTWAIT);
-               if ((n->m_flags & M_EXT) == 0) {
-                       m_freem(n);
-                       n = NULL;
-               }
-       }
+       n = key_alloc_mbuf_simple(len, M_DONTWAIT);
        if (!n)
                return key_senderror(so, m, ENOBUFS);
 
@@ -7728,14 +7717,7 @@
        if (m->m_next) {
                struct mbuf *n;
 
-               MGETHDR(n, M_DONTWAIT, MT_DATA);
-               if (n && m->m_pkthdr.len > MHLEN) {
-                       MCLGET(n, M_DONTWAIT);
-                       if ((n->m_flags & M_EXT) == 0) {
-                               m_free(n);
-                               n = NULL;
-                       }
-               }
+               n = key_alloc_mbuf_simple(m->m_pkthdr.len, M_DONTWAIT);
                if (!n) {
                        m_freem(m);
                        return ENOBUFS;