DNS_LOCAL_HOSTLIST_IS_DYNAMIC uses its own MEMP pool instead of the heap

src/include/lwip/dns.h

@@ -73,6 +73,23 @@
    sizeof(struct addrinfo) + sizeof(struct sockaddr_in) + DNS_MAX_NAME_LENGTH + 1 byte zero-termination */
 #define NETDB_ELEM_SIZE           (32 + 16 + DNS_MAX_NAME_LENGTH + 1)
 
+#if DNS_LOCAL_HOSTLIST
+/** struct used for local host-list */
+struct local_hostlist_entry {
+  /** static hostname */
+  const char *name;
+  /** static host address in network byteorder */
+  ip_addr_t addr;
+  struct local_hostlist_entry *next;
+};
+#if DNS_LOCAL_HOSTLIST_IS_DYNAMIC
+#ifndef DNS_LOCAL_HOSTLIST_MAX_NAMELEN
+#define DNS_LOCAL_HOSTLIST_MAX_NAMELEN  DNS_MAX_NAME_LENGTH
+#endif
+#define LOCALHOSTLIST_ELEM_SIZE ((sizeof(struct local_hostlist_entry) + DNS_LOCAL_HOSTLIST_MAX_NAMELEN + 1))
+#endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
+#endif /* DNS_LOCAL_HOSTLIST */
+
 /** Callback which is invoked when a hostname is found.
  * A function of this type must be implemented by the application using the DNS resolver.
  * @param name pointer to the name that was looked up.

src/include/lwip/memp_std.h

@@ -79,6 +79,9 @@ LWIP_MEMPOOL(SNMP_VALUE,     MEMP_NUM_SNMP_VALUE,      SNMP_MAX_VALUE_SIZE,
 #if LWIP_DNS && LWIP_SOCKET
 LWIP_MEMPOOL(NETDB,          MEMP_NUM_NETDB,           NETDB_ELEM_SIZE,               "NETDB")
 #endif /* LWIP_DNS && LWIP_SOCKET */
+#if LWIP_DNS && DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC
+LWIP_MEMPOOL(LOCALHOSTLIST,  MEMP_NUM_LOCALHOSTLIST,   LOCALHOSTLIST_ELEM_SIZE,       "LOCALHOSTLIST")
+#endif /* LWIP_DNS && DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC */
 
 /*
  * A list of pools of pbuf's used by LWIP.

src/include/lwip/opt.h

@@ -370,6 +370,14 @@
 #define MEMP_NUM_NETDB                  1
 #endif
 
+/**
+ * MEMP_NUM_LOCALHOSTLIST: the number of host entries in the local host list
+ * if DNS_LOCAL_HOSTLIST_IS_DYNAMIC==1.
+ */
+#ifndef MEMP_NUM_LOCALHOSTLIST
+#define MEMP_NUM_LOCALHOSTLIST          1
+#endif
+
 /**
  * PBUF_POOL_SIZE: the number of buffers in the pbuf pool. 
  */