fix strict aliasing rules

Makefile

@@ -1,7 +1,7 @@
 # Makefile to generate dhtest
 
 CC=gcc
-CFLAGS=-Wall -O3 -g -fno-strict-aliasing
+CFLAGS=-Wall -O3 -g
 
 dhtest: dhtest.o functions.o 
 	$(CC) dhtest.o functions.o -o dhtest

functions.c

@@ -921,11 +921,11 @@ int check_packet(int pkt_type)
 		map_all_layer_ptr(ARP_MAP); 
 		if(!vlan) {
 
-			if((ntohs(arp_hg->ar_op)) == ARPOP_REQUEST && (htonl(ip_address)) == (*((u_int32_t *)(arp_hg->target_ip)))) {
+			if((ntohs(arp_hg->ar_op)) == ARPOP_REQUEST && htonl(ip_address) == arp_hg->target_ip32) {
 				return ARP_RCVD;
 			}
 		} else if(vlan && ntohs(vlan) == vlan_hg->vlan_priority_c_vid) {
-			if((ntohs(arp_hg->ar_op)) == ARPOP_REQUEST && (htonl(ip_address)) == (*((u_int32_t *)(arp_hg->target_ip)))) {
+			if((ntohs(arp_hg->ar_op)) == ARPOP_REQUEST && htonl(ip_address) == arp_hg->target_ip32) {
 				fprintf(stdout, "Arp request received\n"); 
 				return ARP_RCVD;
 			}

headers.h

@@ -92,9 +92,15 @@ struct arp_hdr
 #define ARPOP_INVREQUEST 8  /* req to identify peer */
 #define ARPOP_INVREPLY   9  /* resp identifying peer */
 	u_int8_t sender_mac[ETHER_ADDR_LEN];
-	u_int8_t sender_ip[IP_ADDR_LEN];
+	union {
+		u_int8_t sender_ip[IP_ADDR_LEN];
+		u_int32_t sender_ip32;
+	};
 	u_int8_t target_mac[ETHER_ADDR_LEN];
-	u_int8_t target_ip[IP_ADDR_LEN];
+	union {
+		u_int8_t target_ip[IP_ADDR_LEN];
+		u_int32_t target_ip32;
+	};
 };
 
 /*