dhcpv6-ia: switch case refactor in dhcpv6_handle_ias()

rewrite core logic using switch cases for clarity and improved
performance.

Signed-off-by: Paul Donald <newtwen+github@gmail.com>

Author: systemcrash

src/dhcpv6-ia.c

@@ -1263,32 +1263,38 @@ ssize_t dhcpv6_ia_handle_IAs(uint8_t *buf, size_t buflen, struct interface *ifac
 
 
 			/* Was only a solicitation: mark binding for removal in 60 seconds */
-			if (assigned && hdr->msg_type == DHCPV6_MSG_SOLICIT && !rapid_commit) {
-
-				a->bound = false;
-				a->valid_until = now + 60;
-
-			} else if (assigned &&
-				   ((hdr->msg_type == DHCPV6_MSG_SOLICIT && rapid_commit) ||
-				    hdr->msg_type == DHCPV6_MSG_REQUEST ||
-				    hdr->msg_type == DHCPV6_MSG_REBIND)) {
-
-				if (hostname_len > 0 && (!a->lease_cfg || !a->lease_cfg->hostname)) {
-
-					char *tmp = realloc(a->hostname, hostname_len + 1);
-					if (tmp) {
-						a->hostname = tmp;
-						memcpy(a->hostname, hostname, hostname_len);
-						a->hostname[hostname_len] = 0;
-						a->hostname_valid = odhcpd_hostname_valid(a->hostname);
+			if (assigned) {
+				switch (hdr->msg_type) {
+				case DHCPV6_MSG_SOLICIT:
+					if (!rapid_commit) {
+						a->bound = false;
+						a->valid_until = now + 60;
+						break;
+					}
+					_o_fallthrough;
+
+				case DHCPV6_MSG_REQUEST:
+				case DHCPV6_MSG_REBIND:
+					if (hostname_len > 0 && (!a->lease_cfg || !a->lease_cfg->hostname)) {
+
+						char *tmp = realloc(a->hostname, hostname_len + 1);
+						if (tmp) {
+							a->hostname = tmp;
+							memcpy(a->hostname, hostname, hostname_len);
+							a->hostname[hostname_len] = 0;
+							a->hostname_valid = odhcpd_hostname_valid(a->hostname);
+						}
 					}
-				}
 
-				a->accept_fr_nonce = accept_reconf;
-				a->bound = true;
-				apply_lease(a, true);
+					a->accept_fr_nonce = accept_reconf;
+					a->bound = true;
+					apply_lease(a, true);
+					break;
 
-			} else if (!assigned) {
+				default:
+					break;
+				}
+			} else {
 				/* Clean up failed assignment */
 				dhcpv6_free_lease(a);
 				a = NULL;