From 5098b0e414172b2ed3ee9d0db33ca3ddcb72ac8c Mon Sep 17 00:00:00 2001
From: jtl <jtl@FreeBSD.org>
Date: Fri, 20 Apr 2018 14:34:04 +0000
Subject: [PATCH] MFC r331484:   Remove some unneccessary variable sets in IPv6
 code, as detected by   clang's static analyzer.

Sponsored by:	Netflix, Inc.
---
 sys/netinet6/dest6.c       | 2 +-
 sys/netinet6/icmp6.c       | 1 -
 sys/netinet6/ip6_output.c  | 2 +-
 sys/netinet6/udp6_usrreq.c | 2 +-
 4 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/sys/netinet6/dest6.c b/sys/netinet6/dest6.c
index 2b95fd9d011..19c8d26163b 100644
--- a/sys/netinet6/dest6.c
+++ b/sys/netinet6/dest6.c
@@ -91,7 +91,7 @@ dest6_input(struct mbuf **mp, int *offp, int proto)
 	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
 
 	/* search header for all options. */
-	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
+	for (; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
 		if (*opt != IP6OPT_PAD1 &&
 		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
 			IP6STAT_INC(ip6s_toosmall);
diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index 53a228c29ba..7203f497d9e 100644
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -592,7 +592,6 @@ icmp6_input(struct mbuf **mp, int *offp, int proto)
 			n->m_pkthdr.len = n0len + (noff - off);
 			n->m_next = n0;
 		} else {
-			nip6 = mtod(n, struct ip6_hdr *);
 			IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 			    sizeof(*nicmp6));
 			noff = off;
diff --git a/sys/netinet6/ip6_output.c b/sys/netinet6/ip6_output.c
index aa3775cf1f3..8f74d84e08e 100644
--- a/sys/netinet6/ip6_output.c
+++ b/sys/netinet6/ip6_output.c
@@ -1038,7 +1038,7 @@ ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
 	m = m0->m_nextpkt;
 	m0->m_nextpkt = 0;
 	m_freem(m0);
-	for (m0 = m; m; m = m0) {
+	for (; m; m = m0) {
 		m0 = m->m_nextpkt;
 		m->m_nextpkt = 0;
 		if (error == 0) {
diff --git a/sys/netinet6/udp6_usrreq.c b/sys/netinet6/udp6_usrreq.c
index 56faf5a8515..c38375331ed 100644
--- a/sys/netinet6/udp6_usrreq.c
+++ b/sys/netinet6/udp6_usrreq.c
@@ -208,7 +208,6 @@ udp6_input(struct mbuf **mp, int *offp, int proto)
 	uint8_t nxt;
 
 	ifp = m->m_pkthdr.rcvif;
-	ip6 = mtod(m, struct ip6_hdr *);
 
 #ifndef PULLDOWN_TEST
 	IP6_EXTHDR_CHECK(m, off, sizeof(struct udphdr), IPPROTO_DONE);
@@ -218,6 +217,7 @@ udp6_input(struct mbuf **mp, int *offp, int proto)
 	IP6_EXTHDR_GET(uh, struct udphdr *, m, off, sizeof(*uh));
 	if (!uh)
 		return (IPPROTO_DONE);
+	ip6 = mtod(m, struct ip6_hdr *);
 #endif
 
 	UDPSTAT_INC(udps_ipackets);
-- 
2.45.0