inet: constify ip headers and in6_addr

Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 76b8937..ff62e33 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -92,16 +92,16 @@
 static void mld_ifc_timer_expire(unsigned long data);
 static void mld_ifc_event(struct inet6_dev *idev);
 static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
-static void mld_del_delrec(struct inet6_dev *idev, struct in6_addr *addr);
+static void mld_del_delrec(struct inet6_dev *idev, const struct in6_addr *addr);
 static void mld_clear_delrec(struct inet6_dev *idev);
 static int sf_setstate(struct ifmcaddr6 *pmc);
 static void sf_markstate(struct ifmcaddr6 *pmc);
 static void ip6_mc_clear_src(struct ifmcaddr6 *pmc);
-static int ip6_mc_del_src(struct inet6_dev *idev, struct in6_addr *pmca,
-			  int sfmode, int sfcount, struct in6_addr *psfsrc,
+static int ip6_mc_del_src(struct inet6_dev *idev, const struct in6_addr *pmca,
+			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
 			  int delta);
-static int ip6_mc_add_src(struct inet6_dev *idev, struct in6_addr *pmca,
-			  int sfmode, int sfcount, struct in6_addr *psfsrc,
+static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
+			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
 			  int delta);
 static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
 			    struct inet6_dev *idev);
@@ -250,7 +250,7 @@
 
 /* called with rcu_read_lock() */
 static struct inet6_dev *ip6_mc_find_dev_rcu(struct net *net,
-					     struct in6_addr *group,
+					     const struct in6_addr *group,
 					     int ifindex)
 {
 	struct net_device *dev = NULL;
@@ -451,7 +451,7 @@
 
 int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
 {
-	struct in6_addr *group;
+	const struct in6_addr *group;
 	struct ipv6_mc_socklist *pmc;
 	struct inet6_dev *idev;
 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
@@ -542,7 +542,7 @@
 	struct group_filter __user *optval, int __user *optlen)
 {
 	int err, i, count, copycount;
-	struct in6_addr *group;
+	const struct in6_addr *group;
 	struct ipv6_mc_socklist *pmc;
 	struct inet6_dev *idev;
 	struct ipv6_pinfo *inet6 = inet6_sk(sk);
@@ -752,7 +752,7 @@
 	spin_unlock_bh(&idev->mc_lock);
 }
 
-static void mld_del_delrec(struct inet6_dev *idev, struct in6_addr *pmca)
+static void mld_del_delrec(struct inet6_dev *idev, const struct in6_addr *pmca)
 {
 	struct ifmcaddr6 *pmc, *pmc_prev;
 	struct ip6_sf_list *psf, *psf_next;
@@ -1052,7 +1052,7 @@
 
 /* mark EXCLUDE-mode sources */
 static int mld_xmarksources(struct ifmcaddr6 *pmc, int nsrcs,
-	struct in6_addr *srcs)
+	const struct in6_addr *srcs)
 {
 	struct ip6_sf_list *psf;
 	int i, scount;
@@ -1080,7 +1080,7 @@
 }
 
 static int mld_marksources(struct ifmcaddr6 *pmc, int nsrcs,
-	struct in6_addr *srcs)
+	const struct in6_addr *srcs)
 {
 	struct ip6_sf_list *psf;
 	int i, scount;
@@ -1115,7 +1115,7 @@
 {
 	struct mld2_query *mlh2 = NULL;
 	struct ifmcaddr6 *ma;
-	struct in6_addr *group;
+	const struct in6_addr *group;
 	unsigned long max_delay;
 	struct inet6_dev *idev;
 	struct mld_msg *mld;
@@ -1821,7 +1821,7 @@
 }
 
 static int ip6_mc_del1_src(struct ifmcaddr6 *pmc, int sfmode,
-	struct in6_addr *psfsrc)
+	const struct in6_addr *psfsrc)
 {
 	struct ip6_sf_list *psf, *psf_prev;
 	int rv = 0;
@@ -1857,8 +1857,8 @@
 	return rv;
 }
 
-static int ip6_mc_del_src(struct inet6_dev *idev, struct in6_addr *pmca,
-			  int sfmode, int sfcount, struct in6_addr *psfsrc,
+static int ip6_mc_del_src(struct inet6_dev *idev, const struct in6_addr *pmca,
+			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
 			  int delta)
 {
 	struct ifmcaddr6 *pmc;
@@ -1918,7 +1918,7 @@
  * Add multicast single-source filter to the interface list
  */
 static int ip6_mc_add1_src(struct ifmcaddr6 *pmc, int sfmode,
-	struct in6_addr *psfsrc, int delta)
+	const struct in6_addr *psfsrc, int delta)
 {
 	struct ip6_sf_list *psf, *psf_prev;
 
@@ -2021,8 +2021,8 @@
 /*
  * Add multicast source filter list to the interface list
  */
-static int ip6_mc_add_src(struct inet6_dev *idev, struct in6_addr *pmca,
-			  int sfmode, int sfcount, struct in6_addr *psfsrc,
+static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
+			  int sfmode, int sfcount, const struct in6_addr *psfsrc,
 			  int delta)
 {
 	struct ifmcaddr6 *pmc;