[PATCH 05/16] treewide: Use struct assignment instead of memcpy() for IP addresses

[David Gibson <david@gibson.dropbear.id.au>]

We rely on C11 already, so we can use clearer and more type-checkable
struct assignment instead of mempcy() for copying IP addresses around.

This exposes some "pointer could be const" warnings from cppcheck, so
address those too.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 conf.c   | 12 ++++++------
 dhcpv6.c | 10 ++++++----
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/conf.c b/conf.c
index 750fdc86..9b05afeb 100644
--- a/conf.c
+++ b/conf.c
@@ -389,14 +389,14 @@ static void add_dns6(struct ctx *c,
 	/* Guest or container can only access local addresses via redirect */
 	if (IN6_IS_ADDR_LOOPBACK(addr)) {
 		if (!c->no_map_gw) {
-			memcpy(*conf, &c->ip6.gw, sizeof(**conf));
+			**conf = c->ip6.gw;
 			(*conf)++;
 
 			if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_match))
-				memcpy(&c->ip6.dns_match, addr, sizeof(*addr));
+				c->ip6.dns_match = *addr;
 		}
 	} else {
-		memcpy(*conf, addr, sizeof(**conf));
+		**conf = *addr;
 		(*conf)++;
 	}
 
@@ -632,7 +632,7 @@ static unsigned int conf_ip4(unsigned int ifi,
 			ip4->prefix_len = 32;
 	}
 
-	memcpy(&ip4->addr_seen, &ip4->addr, sizeof(ip4->addr_seen));
+	ip4->addr_seen = ip4->addr;
 
 	if (MAC_IS_ZERO(mac)) {
 		int rc = nl_link_get_mac(nl_sock, ifi, mac);
@@ -693,8 +693,8 @@ static unsigned int conf_ip6(unsigned int ifi,
 		return 0;
 	}
 
-	memcpy(&ip6->addr_seen, &ip6->addr, sizeof(ip6->addr));
-	memcpy(&ip6->addr_ll_seen, &ip6->addr_ll, sizeof(ip6->addr_ll));
+	ip6->addr_seen = ip6->addr;
+	ip6->addr_ll_seen = ip6->addr_ll;
 
 	if (MAC_IS_ZERO(mac)) {
 		rc = nl_link_get_mac(nl_sock, ifi, mac);
diff --git a/dhcpv6.c b/dhcpv6.c
index bbed41dc..87b3c3eb 100644
--- a/dhcpv6.c
+++ b/dhcpv6.c
@@ -298,7 +298,8 @@ static struct opt_hdr *dhcpv6_ia_notonlink(const struct pool *p,
 {
 	char buf[INET6_ADDRSTRLEN];
 	struct in6_addr req_addr;
-	struct opt_hdr *ia, *h;
+	const struct opt_hdr *h;
+	struct opt_hdr *ia;
 	size_t offset;
 	int ia_type;
 
@@ -312,12 +313,13 @@ ia_ta:
 		offset += sizeof(struct opt_ia_na);
 
 		while ((h = dhcpv6_opt(p, &offset, OPT_IAAADR))) {
-			struct opt_ia_addr *opt_addr = (struct opt_ia_addr *)h;
+			const struct opt_ia_addr *opt_addr
+				= (const struct opt_ia_addr *)h;
 
 			if (ntohs(h->l) != OPT_VSIZE(ia_addr))
 				return NULL;
 
-			memcpy(&req_addr, &opt_addr->addr, sizeof(req_addr));
+			req_addr = opt_addr->addr;
 			if (!IN6_ARE_ADDR_EQUAL(la, &req_addr)) {
 				info("DHCPv6: requested address %s not on link",
 				     inet_ntop(AF_INET6, &req_addr,
@@ -363,7 +365,7 @@ static size_t dhcpv6_dns_fill(const struct ctx *c, char *buf, int offset)
 			srv->hdr.l = 0;
 		}
 
-		memcpy(&srv->addr[i], &c->ip6.dns[i], sizeof(srv->addr[i]));
+		srv->addr[i] = c->ip6.dns[i];
 		srv->hdr.l += sizeof(srv->addr[i]);
 		offset += sizeof(srv->addr[i]);
 	}
-- 
@@ -298,7 +298,8 @@ static struct opt_hdr *dhcpv6_ia_notonlink(const struct pool *p,
 {
 	char buf[INET6_ADDRSTRLEN];
 	struct in6_addr req_addr;
-	struct opt_hdr *ia, *h;
+	const struct opt_hdr *h;
+	struct opt_hdr *ia;
 	size_t offset;
 	int ia_type;
 
@@ -312,12 +313,13 @@ ia_ta:
 		offset += sizeof(struct opt_ia_na);
 
 		while ((h = dhcpv6_opt(p, &offset, OPT_IAAADR))) {
-			struct opt_ia_addr *opt_addr = (struct opt_ia_addr *)h;
+			const struct opt_ia_addr *opt_addr
+				= (const struct opt_ia_addr *)h;
 
 			if (ntohs(h->l) != OPT_VSIZE(ia_addr))
 				return NULL;
 
-			memcpy(&req_addr, &opt_addr->addr, sizeof(req_addr));
+			req_addr = opt_addr->addr;
 			if (!IN6_ARE_ADDR_EQUAL(la, &req_addr)) {
 				info("DHCPv6: requested address %s not on link",
 				     inet_ntop(AF_INET6, &req_addr,
@@ -363,7 +365,7 @@ static size_t dhcpv6_dns_fill(const struct ctx *c, char *buf, int offset)
 			srv->hdr.l = 0;
 		}
 
-		memcpy(&srv->addr[i], &c->ip6.dns[i], sizeof(srv->addr[i]));
+		srv->addr[i] = c->ip6.dns[i];
 		srv->hdr.l += sizeof(srv->addr[i]);
 		offset += sizeof(srv->addr[i]);
 	}
-- 
2.46.0