ipv6_netif: add prefix list to interface

sys/include/net/ng_ipv6/netif.h

@@ -68,6 +68,7 @@ extern "C" {
 typedef struct {
     ng_ipv6_addr_t addr;    /**< The address data */
     uint8_t flags;          /**< flags */
+    uint8_t prefix_len;     /**< length of the prefix of the address */
 } ng_ipv6_netif_addr_t;
 
 /**
@@ -119,6 +120,8 @@ ng_ipv6_netif_t *ng_ipv6_netif_get(kernel_pid_t pid);
  *
  * @param[in] pid           The PID to the interface.
  * @param[in] addr          An address you want to add to the interface.
+ * @param[in] prefix_len    Length of the prefix of the address.
+ *                          Must be between 1 and 128.
  * @param[in] anycast       If @p addr should be an anycast address, @p anycast
  *                          must be true. Otherwise set it false.
  *                          If @p addr is a multicast address, @p anycast will be
@@ -129,12 +132,13 @@ ng_ipv6_netif_t *ng_ipv6_netif_get(kernel_pid_t pid);
  *      </a>
  *
  * @return  0, on success.
- * @return  -EINVAL, if @p addr is NULL or unspecified address.
+ * @return  -EINVAL, if @p addr is NULL or unspecified address or if
+ *          @p prefix length was < 1 or > 128.
  * @return  -ENOENT, if @p pid is no interface.
  * @return  -ENOMEM, if there is no space left to store @p addr.
  */
 int ng_ipv6_netif_add_addr(kernel_pid_t pid, const ng_ipv6_addr_t *addr,
-                           bool anycast);
+                           uint8_t prefix_len, bool anycast);
 
 /**
  * @brief   Remove an address from the interface.

sys/net/network_layer/ng_ipv6/netif/ng_ipv6_netif.c

@@ -36,7 +36,7 @@ static char addr_str[NG_IPV6_ADDR_MAX_STR_LEN];
 #endif
 
 static int _add_addr_to_entry(ng_ipv6_netif_t *entry, const ng_ipv6_addr_t *addr,
-                              bool anycast)
+                              uint8_t prefix_len, bool anycast)
 {
     for (int i = 0; i < NG_IPV6_NETIF_ADDR_NUMOF; i++) {
         if (ng_ipv6_addr_equal(&(entry->addrs[i].addr), addr)) {
@@ -44,15 +44,22 @@ static int _add_addr_to_entry(ng_ipv6_netif_t *entry, const ng_ipv6_addr_t *addr
         }
 
         if (ng_ipv6_addr_is_unspecified(&(entry->addrs[i].addr))) {
-            DEBUG("Add %s to interface %" PRIkernel_pid "\n",
-                  ng_ipv6_addr_to_str(addr_str, addr, sizeof(addr_str)),
-                  entry->pid);
             memcpy(&(entry->addrs[i].addr), addr, sizeof(ng_ipv6_addr_t));
+            DEBUG("Added %s/%" PRIu8 " to interface %" PRIkernel_pid "\n",
+                  ng_ipv6_addr_to_str(&(entry->addrs[i].addr), addr,
+                                      sizeof(addr_str)),
+                  prefix_len, entry->pid);
 
             if (anycast || ng_ipv6_addr_is_multicast(addr)) {
+                if (ng_ipv6_addr_is_multicast(addr)) {
+                    entry->addrs[i].prefix_len = NG_IPV6_ADDR_BIT_LEN;
+                }
+
                 entry->addrs[i].flags = NG_IPV6_NETIF_FLAGS_NON_UNICAST;
             }
             else {
+                entry->addrs[i].prefix_len = prefix_len;
+
                 entry->addrs[i].flags = NG_IPV6_NETIF_FLAGS_UNICAST;
             }
 
@@ -96,7 +103,7 @@ void ng_ipv6_netif_add(kernel_pid_t pid)
             ipv6_ifs[i].mtu = NG_IPV6_DEFAULT_MTU;
             DEBUG(" * mtu = %d\n", ipv6_ifs[i].mtu);
 
-            _add_addr_to_entry(&ipv6_ifs[i], &addr, 0);
+            _add_addr_to_entry(&ipv6_ifs[i], &addr, NG_IPV6_ADDR_BIT_LEN, 0);
 
             mutex_unlock(&ipv6_ifs[i].mutex);
 
@@ -138,7 +145,7 @@ ng_ipv6_netif_t *ng_ipv6_netif_get(kernel_pid_t pid)
 }
 
 int ng_ipv6_netif_add_addr(kernel_pid_t pid, const ng_ipv6_addr_t *addr,
-                           bool anycast)
+                           uint8_t prefix_len, bool anycast)
 {
     ng_ipv6_netif_t *entry = ng_ipv6_netif_get(pid);
     int res;
@@ -147,13 +154,14 @@ int ng_ipv6_netif_add_addr(kernel_pid_t pid, const ng_ipv6_addr_t *addr,
         return -ENOENT;
     }
 
-    if ((addr == NULL) || (ng_ipv6_addr_is_unspecified(addr))) {
+    if ((addr == NULL) || (ng_ipv6_addr_is_unspecified(addr)) ||
+        ((prefix_len - 1) > 127)) {    /* prefix_len < 1 || prefix_len > 128 */
         return -EINVAL;
     }
 
     mutex_lock(&entry->mutex);
 
-    res = _add_addr_to_entry(entry, addr, anycast);
+    res = _add_addr_to_entry(entry, addr, prefix_len, anycast);
 
     mutex_unlock(&entry->mutex);
 
@@ -271,6 +279,11 @@ static uint8_t _find_by_prefix_unsafe(ng_ipv6_addr_t **res, ng_ipv6_netif_t *ifa
 
         match = ng_ipv6_addr_match_prefix(&(iface->addrs[i].addr), addr);
 
+        if (match < iface->addrs[i].prefix_len) {
+            /* match but not of same subnet */
+            continue;
+        }
+
         if (match > best_match) {
             if (res != NULL) {
                 *res = &(iface->addrs[i].addr);