[src/trunk]: src/sys/netipsec Add a KASSERT (which is not triggerable since i...

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

details:   https://anonhg.NetBSD.org/src/rev/0d51563e855c
branches:  trunk
changeset: 831907:0d51563e855c
user:      maxv <maxv%NetBSD.org@localhost>
date:      Thu Apr 19 07:58:26 2018 +0000

description:
Add a KASSERT (which is not triggerable since ipsec_common_input already
ensures 8 bytes are present), add an XXX (about the fact that it is
better to use m_copydata, because it is faster and less error-prone), and
improve two m_copybacks (remove useless casts).

diffstat:

 sys/netipsec/xform_ipcomp.c |  17 +++++++++++------
 1 files changed, 11 insertions(+), 6 deletions(-)

diffs (67 lines):

diff -r 7a710d5678ab -r 0d51563e855c sys/netipsec/xform_ipcomp.c
--- a/sys/netipsec/xform_ipcomp.c       Thu Apr 19 07:40:12 2018 +0000
+++ b/sys/netipsec/xform_ipcomp.c       Thu Apr 19 07:58:26 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xform_ipcomp.c,v 1.60 2018/03/10 17:48:32 maxv Exp $   */
+/*     $NetBSD: xform_ipcomp.c,v 1.61 2018/04/19 07:58:26 maxv Exp $   */
 /*     $FreeBSD: src/sys/netipsec/xform_ipcomp.c,v 1.1.4.1 2003/01/24 05:11:36 sam Exp $       */
 /* $OpenBSD: ip_ipcomp.c,v 1.1 2001/07/05 12:08:52 jjbg Exp $ */
 
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xform_ipcomp.c,v 1.60 2018/03/10 17:48:32 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xform_ipcomp.c,v 1.61 2018/04/19 07:58:26 maxv Exp $");
 
 /* IP payload compression protocol (IPComp), see RFC 2393 */
 #if defined(_KERNEL_OPT)
@@ -147,6 +147,7 @@
        int error, hlen = IPCOMP_HLENGTH, stat = IPCOMP_STAT_CRYPTO;
 
        IPSEC_SPLASSERT_SOFTNET(__func__);
+       KASSERT(skip + hlen <= m->m_pkthdr.len);
 
        /* Get crypto descriptors */
        crp = crypto_getreq(1);
@@ -307,16 +308,20 @@
        /* In case it's not done already, adjust the size of the mbuf chain */
        m->m_pkthdr.len = clen + hlen + skip;
 
+       /*
+        * Get the next protocol field.
+        *
+        * XXX: Really, we should use m_copydata instead of m_pullup.
+        */
        if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) {
                IPCOMP_STATINC(IPCOMP_STAT_HDROPS);
                DPRINTF(("%s: m_pullup failed\n", __func__));
                error = EINVAL;
                goto bad;
        }
-
-       /* Keep the next protocol field */
        ipc = (struct ipcomp *)(mtod(m, uint8_t *) + skip);
        nproto = ipc->comp_nxt;
+
        switch (nproto) {
        case IPPROTO_IPCOMP:
        case IPPROTO_AH:
@@ -342,7 +347,7 @@
        }
 
        /* Restore the Next Protocol field */
-       m_copyback(m, protoff, sizeof(uint8_t), (uint8_t *)&nproto);
+       m_copyback(m, protoff, sizeof(nproto), &nproto);
 
        IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff);
 
@@ -602,7 +607,7 @@
 
                /* Fix Next Protocol in IPv4/IPv6 header */
                prot = IPPROTO_IPCOMP;
-               m_copyback(m, tc->tc_protoff, sizeof(uint8_t), (u_char *)&prot);
+               m_copyback(m, tc->tc_protoff, sizeof(prot), &prot);
 
                /* Adjust the length in the IP header */
                switch (sav->sah->saidx.dst.sa.sa_family) {