Calculate ICMP checksums with in4_cksum() which lets us get rid of the

clunky m_data/m_len dance needed by in_cksum().

Tested on amd64, hppa, i386, loongson, macppc, sgi, and sparc64.

Thanks to blambert@, bluhm@, and henning@ for help and feedback;
abieber@ for testing this diff independently on macppc; krw@ for access
to his hppa, sgi, and sparc64 test systems at t2k13; nick@ for helping
me figure out Ken's hppa so that I can test this diff. :)

ok blambert bluhm henning mikeb

2 files changed, 9 insertions, 20 deletions

diff --git a/sys/netinet/ip_icmp.c b/sys/netinet/ip_icmp.c
index 1680ac52816..baef294334c 100644
--- a/sys/netinet/ip_icmp.c
+++ b/sys/netinet/ip_icmp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_icmp.c,v 1.99 2013/05/03 09:35:20 mpi Exp $	*/
+/*	$OpenBSD: ip_icmp.c,v 1.100 2013/06/05 02:25:05 lteo Exp $	*/
 /*	$NetBSD: ip_icmp.c,v 1.19 1996/02/13 23:42:22 christos Exp $	*/
 
 /*
@@ -347,16 +347,12 @@ icmp_input(struct mbuf *m, ...)
 		return;
 	}
 	ip = mtod(m, struct ip *);
-	m->m_len -= hlen;
-	m->m_data += hlen;
-	icp = mtod(m, struct icmp *);
-	if (in_cksum(m, icmplen)) {
+	if (in4_cksum(m, 0, hlen, icmplen)) {
 		icmpstat.icps_checksum++;
 		goto freeit;
 	}
-	m->m_len += hlen;
-	m->m_data -= hlen;
 
+	icp = (struct icmp *)(mtod(m, caddr_t) + hlen);
 #ifdef ICMPPRINTFS
 	/*
 	 * Message type specific processing.
@@ -807,13 +803,9 @@ icmp_send(struct mbuf *m, struct mbuf *opts)
 	struct icmp *icp;
 
 	hlen = ip->ip_hl << 2;
-	m->m_data += hlen;
-	m->m_len -= hlen;
-	icp = mtod(m, struct icmp *);
+	icp = (struct icmp *)(mtod(m, caddr_t) + hlen);
 	icp->icmp_cksum = 0;
-	icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen);
-	m->m_data -= hlen;
-	m->m_len += hlen;
+	icp->icmp_cksum = in4_cksum(m, 0, hlen, ntohs(ip->ip_len) - hlen);
 #ifdef ICMPPRINTFS
 	if (icmpprintfs) {
 		char buf[4 * sizeof("123")];
diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c
index 00c2e21957c..099f71ffc05 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ip_output.c,v 1.239 2013/04/24 12:34:15 mpi Exp $	*/
+/*	$OpenBSD: ip_output.c,v 1.240 2013/06/05 02:25:05 lteo Exp $	*/
 /*	$NetBSD: ip_output.c,v 1.28 1996/02/13 23:43:07 christos Exp $	*/
 
 /*
@@ -2126,13 +2126,10 @@ in_proto_cksum_out(struct mbuf *m, struct ifnet *ifp)
 		struct icmp *icp;
 
 		hlen = ip->ip_hl << 2;
-		m->m_data += hlen;
-		m->m_len -= hlen;
-		icp = mtod(m, struct icmp *);
+		icp = (struct icmp *)(mtod(m, caddr_t) + hlen);
 		icp->icmp_cksum = 0;
-		icp->icmp_cksum = in_cksum(m, ntohs(ip->ip_len) - hlen);
-		m->m_data -= hlen;
-		m->m_len += hlen;
+		icp->icmp_cksum = in4_cksum(m, 0, hlen,
+		    ntohs(ip->ip_len) - hlen);
 		m->m_pkthdr.csum_flags &= ~M_ICMP_CSUM_OUT; /* Clear */
 	}
 }