Fix possible memory alignment issues

xfangfang#34 (comment)

Author: xfangfang

src/exploit.cpp

@@ -1,5 +1,6 @@
 #include <iostream>
 #include <sstream>
+#include <cstring>
 
 #include <IPv6Layer.h>
 #include <IPv4Layer.h>
@@ -87,11 +88,11 @@ struct Cookie {
 #define htole16
 #endif
 
-#define V64BE(list, index, data) (*(uint64_t *) &(list)[index]) = htobe64(data)
-#define V64(list, index, data) (*(uint64_t *) &(list)[index]) = htole64(data)
-#define V32(list, index, data) (*(uint32_t *) &(list)[index]) = htole32(data)
-#define V16(list, index, data) (*(uint16_t *) &(list)[index]) = htole16(data)
-#define V8(list, index, data) (*(uint8_t *) &(list)[index]) = data
+#define V64BE(list, index, data) {uint64_t temp = htobe64(data); std::memcpy(&(list)[index], &temp, sizeof(uint64_t));}
+#define V64(list, index, data) {uint64_t temp = htole64(data); std::memcpy(&(list)[index], &temp, sizeof(uint64_t));}
+#define V32(list, index, data) {uint32_t temp = htole32(data); std::memcpy(&(list)[index], &temp, sizeof(uint32_t));}
+#define V16(list, index, data) {uint16_t temp = htole16(data); std::memcpy(&(list)[index], &temp, sizeof(uint16_t));}
+#define V8(list, index, data) {uint8_t temp = data; std::memcpy(&(list)[index], &temp, sizeof(uint8_t));}
 
 #define CHECK_RET(value) { int ret = (value); if(ret != RETURN_SUCCESS) return ret;}
 #define CHECK_RUNNING() if (!running) return RETURN_STOP
@@ -937,7 +938,8 @@ int Exploit::stage2() {
                 if (option[0] != 1) return false; // type 1 is ICMPv6NDOptSrcLLAddr
                 if (option[1] > 1) {
                     auto *self = (Exploit *) cookie;
-                    self->pppoe_softc_list = htole64(*(uint64_t * )(option + 3));
+                    std::memcpy(&self->pppoe_softc_list, option + 3, sizeof(uint64_t));
+                    self->pppoe_softc_list = htole64(self->pppoe_softc_list);
                     return true; // length > 1
                 }
                 return false;