lib, irmd, ipcpd: Add name querying to IPCPs

This adds the ability to query IPCPs if a name can be reached through
them, e.g. if a name is available in a DIF. This means that in the
shim-udp a DNS query is performed, in the shim-eth-llc an ARP-like
query has been added, in the local a check is done to see if the name
is registered, and in the normal currently no application is reachable
through it.

15 files changed, 604 insertions, 276 deletions

diff --git a/src/ipcpd/ipcp-data.c b/src/ipcpd/ipcp-data.c
index ed7e578d..b3078054 100644
--- a/src/ipcpd/ipcp-data.c
+++ b/src/ipcpd/ipcp-data.c
@@ -21,14 +21,16 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
-#include <ouroboros/config.h>
-#include <ouroboros/list.h>
-
 #define OUROBOROS_PREFIX "ipcp-utils"
 
+#include <ouroboros/config.h>
+#include <ouroboros/list.h>
+#include <ouroboros/time_utils.h>
 #include <ouroboros/logs.h>
+#include <ouroboros/errno.h>
 
 #include "ipcp-data.h"
+#include "ipcp.h"
 
 #include <string.h>
 #include <stdlib.h>
@@ -41,8 +43,8 @@ struct reg_entry {
 
 struct dir_entry {
         struct list_head list;
-        char *     ap_name;
-        uint64_t   addr;
+        char *           name;
+        uint64_t         addr;
 };
 
 static struct reg_entry * reg_entry_create(char * name)
@@ -70,18 +72,18 @@ static void reg_entry_destroy(struct reg_entry * entry)
         free(entry);
 }
 
-static struct dir_entry * dir_entry_create(char *   ap_name,
+static struct dir_entry * dir_entry_create(char *   name,
                                            uint64_t addr)
 {
         struct dir_entry * entry = malloc(sizeof(*entry));
         if (entry == NULL)
                 return NULL;
 
-        assert(ap_name);
+        assert(name);
 
         entry->addr    = addr;
-        entry->ap_name = ap_name;
-        if (entry->ap_name == NULL)
+        entry->name = name;
+        if (entry->name == NULL)
                 return NULL;
 
         return entry;
@@ -91,8 +93,8 @@ static void dir_entry_destroy(struct dir_entry * entry)
 {
         assert(entry);
 
-        if (entry->ap_name != NULL)
-                free(entry->ap_name);
+        if (entry->name != NULL)
+                free(entry->name);
 
         free(entry);
 }
@@ -120,10 +122,12 @@ struct ipcp_data * ipcp_data_init(struct ipcp_data * dst,
         /* init the lists */
         INIT_LIST_HEAD(&dst->registry);
         INIT_LIST_HEAD(&dst->directory);
+        INIT_LIST_HEAD(&dst->dir_queries);
 
         /* init the locks */
         pthread_rwlock_init(&dst->reg_lock, NULL);
         pthread_rwlock_init(&dst->dir_lock, NULL);
+        pthread_mutex_init(&dst->dir_queries_lock, NULL);
 
         return dst;
 }
@@ -156,6 +160,20 @@ static void clear_directory(struct ipcp_data * data)
         }
 }
 
+static void clear_dir_queries(struct ipcp_data * data)
+{
+        struct list_head * h;
+        struct list_head * t;
+
+        assert(data);
+
+        list_for_each_safe(h, t, &data->dir_queries) {
+                struct dir_query * e = list_entry(h, struct dir_query, next);
+                list_del(&e->next);
+                ipcp_data_dir_query_destroy(e);
+        }
+}
+
 void ipcp_data_destroy(struct ipcp_data * data)
 {
         if (data == NULL)
@@ -163,27 +181,27 @@ void ipcp_data_destroy(struct ipcp_data * data)
 
         /* clear the lists */
         pthread_rwlock_wrlock(&data->reg_lock);
-
         clear_registry(data);
-
         pthread_rwlock_unlock(&data->reg_lock);
-        pthread_rwlock_wrlock(&data->dir_lock);
 
+        pthread_rwlock_wrlock(&data->dir_lock);
         clear_directory(data);
-
         pthread_rwlock_unlock(&data->dir_lock);
 
+        pthread_mutex_lock(&data->dir_queries_lock);
+        clear_dir_queries(data);
+        pthread_mutex_unlock(&data->dir_queries_lock);
+
         if (data->dif_name != NULL)
                 free(data->dif_name);
 
         pthread_rwlock_destroy(&data->dir_lock);
         pthread_rwlock_destroy(&data->reg_lock);
+        pthread_mutex_destroy(&data->dir_queries_lock);
 
         free(data);
 }
 
-
-
 static struct reg_entry * find_reg_entry_by_name(struct ipcp_data * data,
                                                  const char *       name)
 {
@@ -202,13 +220,13 @@ static struct reg_entry * find_reg_entry_by_name(struct ipcp_data * data,
 }
 
 static struct dir_entry * find_dir_entry(struct ipcp_data * data,
-                                         const char *       ap_name,
+                                         const char *       name,
                                          uint64_t           addr)
 {
         struct list_head * h;
         list_for_each(h, &data->directory) {
                 struct dir_entry * e = list_entry(h, struct dir_entry, list);
-                if (e->addr == addr && !strcmp(e->ap_name, ap_name))
+                if (e->addr == addr && !strcmp(e->name, name))
                         return e;
         }
 
@@ -216,33 +234,47 @@ static struct dir_entry * find_dir_entry(struct ipcp_data * data,
 }
 
 static struct dir_entry * find_dir_entry_any(struct ipcp_data * data,
-                                             const char *       ap_name)
+                                             const char *       name)
 {
         struct list_head * h;
         list_for_each(h, &data->directory) {
                 struct dir_entry * e = list_entry(h, struct dir_entry, list);
-                if (!strcmp(e->ap_name, ap_name))
+                if (!strcmp(e->name, name))
                         return e;
         }
 
         return NULL;
 }
 
-bool ipcp_data_is_in_directory(struct ipcp_data * data,
-                               const char *       ap_name)
+int ipcp_data_reg_add_entry(struct ipcp_data * data,
+                            char *             name)
 {
-        bool ret = false;
+        struct reg_entry * entry;
 
-        pthread_rwlock_rdlock(&data->dir_lock);
+        if (data == NULL || name == NULL)
+                return -1;
 
-        ret = (find_dir_entry_any(data, ap_name) != NULL);
+        pthread_rwlock_wrlock(&data->reg_lock);
 
-        pthread_rwlock_unlock(&data->dir_lock);
+        if (find_reg_entry_by_name(data, name)) {
+                pthread_rwlock_unlock(&data->reg_lock);
+                return -1;
+        }
 
-        return ret;
+        entry = reg_entry_create(name);
+        if (entry == NULL) {
+                pthread_rwlock_unlock(&data->reg_lock);
+                return -1;
+        }
+
+        list_add(&entry->list, &data->registry);
+
+        pthread_rwlock_unlock(&data->reg_lock);
+
+        return 0;
 }
 
-int ipcp_data_del_reg_entry(struct ipcp_data * data,
+int ipcp_data_reg_del_entry(struct ipcp_data * data,
                             const char *       name)
 {
         struct reg_entry * e;
@@ -266,114 +298,109 @@ int ipcp_data_del_reg_entry(struct ipcp_data * data,
         return 0;
 }
 
-int ipcp_data_del_dir_entry(struct ipcp_data * data,
-                            const char *       ap_name,
-                            uint64_t           addr)
+bool ipcp_data_reg_has(struct ipcp_data * data,
+                       const char *       name)
 {
-        struct dir_entry * e;
-        if (data == NULL)
-                return -1;
-
-        pthread_rwlock_wrlock(&data->dir_lock);
+        bool ret = false;
 
-        e = find_dir_entry(data, ap_name, addr);
-        if (e == NULL) {
-                pthread_rwlock_unlock(&data->dir_lock);
-                return 0; /* nothing to do */
-        }
+        if (data == NULL || name == NULL)
+                return false;
 
-        list_del(&e->list);
+        pthread_rwlock_rdlock(&data->reg_lock);
 
-        pthread_rwlock_unlock(&data->dir_lock);
+        ret = (find_reg_entry_by_name(data, name) != NULL);
 
-        dir_entry_destroy(e);
+        pthread_rwlock_unlock(&data->reg_lock);
 
-        return 0;
+        return ret;
 }
 
-int ipcp_data_add_reg_entry(struct ipcp_data * data,
-                            char *             name)
+int ipcp_data_dir_add_entry(struct ipcp_data * data,
+                            char *             name,
+                            uint64_t           addr)
 {
-        struct reg_entry * entry;
+        struct dir_entry * entry;
+        char * entry_name;
 
         if (data == NULL || name == NULL)
                 return -1;
 
-        pthread_rwlock_wrlock(&data->reg_lock);
+        pthread_rwlock_wrlock(&data->dir_lock);
 
-        if (find_reg_entry_by_name(data, name)) {
-                pthread_rwlock_unlock(&data->reg_lock);
+        if (find_dir_entry(data, name, addr) != NULL) {
+                pthread_rwlock_unlock(&data->dir_lock);
                 return -1;
         }
 
-        entry = reg_entry_create(name);
+        entry_name = strdup(name);
+        if (entry_name == NULL) {
+                pthread_rwlock_unlock(&data->dir_lock);
+                return -1;
+        }
+
+        entry = dir_entry_create(entry_name, addr);
         if (entry == NULL) {
-                pthread_rwlock_unlock(&data->reg_lock);
+                pthread_rwlock_unlock(&data->dir_lock);
                 return -1;
         }
 
-        list_add(&entry->list, &data->registry);
+        list_add(&entry->list,&data->directory);
 
-        pthread_rwlock_unlock(&data->reg_lock);
+        pthread_rwlock_unlock(&data->dir_lock);
+
+        LOG_DBG("Added directory entry for %s.", entry_name);
 
         return 0;
 }
 
-int ipcp_data_add_dir_entry(struct ipcp_data * data,
-                            char *             ap_name,
+int ipcp_data_dir_del_entry(struct ipcp_data * data,
+                            const char *       name,
                             uint64_t           addr)
 {
-        struct dir_entry * entry;
-
-        if (data == NULL || ap_name == NULL)
+        struct dir_entry * e;
+        if (data == NULL)
                 return -1;
 
         pthread_rwlock_wrlock(&data->dir_lock);
 
-        if (find_dir_entry(data, ap_name, addr) != NULL) {
-                pthread_rwlock_unlock(&data->dir_lock);
-                return -1;
-        }
-
-        entry = dir_entry_create(ap_name, addr);
-        if (entry == NULL) {
+        e = find_dir_entry(data, name, addr);
+        if (e == NULL) {
                 pthread_rwlock_unlock(&data->dir_lock);
-                return -1;
+                return 0; /* nothing to do */
         }
 
-        list_add(&entry->list,&data->directory);
+        list_del(&e->list);
 
         pthread_rwlock_unlock(&data->dir_lock);
 
+        dir_entry_destroy(e);
+
         return 0;
 }
 
-bool ipcp_data_is_in_registry(struct ipcp_data * data,
-                              const char *       ap_name)
+bool ipcp_data_dir_has(struct ipcp_data * data,
+                       const char *       name)
 {
         bool ret = false;
 
-        if (data == NULL || ap_name == NULL)
-                return false;
-
-        pthread_rwlock_rdlock(&data->reg_lock);
+        pthread_rwlock_rdlock(&data->dir_lock);
 
-        ret = (find_reg_entry_by_name(data, ap_name) != NULL);
+        ret = (find_dir_entry_any(data, name) != NULL);
 
-        pthread_rwlock_unlock(&data->reg_lock);
+        pthread_rwlock_unlock(&data->dir_lock);
 
         return ret;
 }
 
-uint64_t ipcp_data_get_addr(struct ipcp_data * data,
-                            const char *       ap_name)
+uint64_t ipcp_data_dir_get_addr(struct ipcp_data * data,
+                                const char *       name)
 {
         struct dir_entry * entry;
         uint64_t           addr;
 
         pthread_rwlock_rdlock(&data->dir_lock);
 
-        entry = find_dir_entry_any(data, ap_name);
+        entry = find_dir_entry_any(data, name);
 
         if (entry == NULL) {
                 pthread_rwlock_unlock(&data->dir_lock);
@@ -386,3 +413,122 @@ uint64_t ipcp_data_get_addr(struct ipcp_data * data,
 
         return addr;
 }
+
+struct dir_query * ipcp_data_dir_query_create(char * name)
+{
+        struct dir_query * query;
+        pthread_condattr_t cattr;
+
+        query = malloc(sizeof(*query));
+        if (query == NULL)
+                return NULL;
+
+        query->name = strdup(name);
+        if (query->name == NULL) {
+                free(query);
+                return NULL;
+        }
+
+        query->state = QUERY_INIT;
+
+        pthread_condattr_init(&cattr);
+#ifndef __APPLE__
+        pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
+#endif
+        pthread_cond_init(&query->cond, &cattr);
+        pthread_mutex_init(&query->lock, NULL);
+
+        INIT_LIST_HEAD(&query->next);
+
+        return query;
+}
+
+void ipcp_data_dir_query_respond(struct dir_query * query)
+{
+        assert(query);
+
+        pthread_mutex_lock(&query->lock);
+
+        if (query->state != QUERY_PENDING) {
+                pthread_mutex_unlock(&query->lock);
+                return;
+        }
+
+        query->state = QUERY_RESPONSE;
+        pthread_cond_broadcast(&query->cond);
+
+        while (query->state == QUERY_RESPONSE)
+                pthread_cond_wait(&query->cond, &query->lock);
+
+        pthread_mutex_unlock(&query->lock);
+}
+
+void ipcp_data_dir_query_destroy(struct dir_query * query)
+{
+        assert(query);
+
+        pthread_mutex_lock(&query->lock);
+
+        if (query->state == QUERY_DESTROY) {
+                pthread_mutex_unlock(&query->lock);
+                return;
+        }
+
+        if (query->state == QUERY_INIT)
+                query->state = QUERY_DONE;
+
+        if (query->state == QUERY_PENDING) {
+                query->state = QUERY_DESTROY;
+                pthread_cond_broadcast(&query->cond);
+        }
+
+        while (query->state != QUERY_DONE)
+                pthread_cond_wait(&query->cond, &query->lock);
+
+        pthread_mutex_unlock(&query->lock);
+
+        pthread_cond_destroy(&query->cond);
+        pthread_mutex_destroy(&query->lock);
+
+        free(query->name);
+        free(query);
+}
+
+int ipcp_data_dir_query_wait(struct dir_query * query,
+                             const struct timespec * timeout)
+{
+        struct timespec abstime;
+        int ret = 0;
+
+        assert(query);
+        assert(timeout);
+
+        clock_gettime(PTHREAD_COND_CLOCK, &abstime);
+        ts_add(&abstime, timeout, &abstime);
+
+        pthread_mutex_lock(&query->lock);
+
+        if (query->state != QUERY_INIT) {
+                pthread_mutex_unlock(&query->lock);
+                return -EINVAL;
+        }
+
+        query->state = QUERY_PENDING;
+
+        while (query->state == QUERY_PENDING) {
+                if ((ret = -pthread_cond_timedwait(&query->cond,
+                                                   &query->lock,
+                                                   &abstime)) == -ETIMEDOUT)
+                        break;
+        }
+
+        if (query->state == QUERY_DESTROY)
+                ret = -1;
+
+        query->state = QUERY_DONE;
+        pthread_cond_broadcast(&query->cond);
+
+        pthread_mutex_unlock(&query->lock);
+
+        return ret;
+}
diff --git a/src/ipcpd/ipcp-data.h b/src/ipcpd/ipcp-data.h
index 4472a1d7..5263b156 100644
--- a/src/ipcpd/ipcp-data.h
+++ b/src/ipcpd/ipcp-data.h
@@ -26,10 +26,28 @@
 
 #include <ouroboros/shared.h>
 #include <ouroboros/list.h>
+
+#include "ipcp-ops.h"
+
 #include <sys/types.h>
 #include <pthread.h>
 
-#include "ipcp-ops.h"
+enum dir_query_state {
+        QUERY_INIT = 0,
+        QUERY_PENDING,
+        QUERY_RESPONSE,
+        QUERY_DONE,
+        QUERY_DESTROY
+};
+
+struct dir_query {
+        struct list_head     next;
+        char *               name;
+        enum dir_query_state state;
+
+        pthread_mutex_t      lock;
+        pthread_cond_t       cond;
+};
 
 struct ipcp_data {
         enum ipcp_type      type;
@@ -40,6 +58,9 @@ struct ipcp_data {
 
         struct list_head    directory;
         pthread_rwlock_t    dir_lock;
+
+        struct list_head    dir_queries;
+        pthread_mutex_t     dir_queries_lock;
 };
 
 struct ipcp_data * ipcp_data_create(void);
@@ -49,26 +70,35 @@ struct ipcp_data * ipcp_data_init(struct ipcp_data * dst,
 
 void               ipcp_data_destroy(struct ipcp_data * data);
 
-int                ipcp_data_add_reg_entry(struct ipcp_data * data,
+int                ipcp_data_reg_add_entry(struct ipcp_data * data,
                                            char *             name);
 
-int                ipcp_data_del_reg_entry(struct ipcp_data * data,
+int                ipcp_data_reg_del_entry(struct ipcp_data * data,
                                            const char *       name);
 
-int                ipcp_data_add_dir_entry(struct ipcp_data * data,
-                                           char *             ap_name,
+bool               ipcp_data_reg_has(struct ipcp_data * data,
+                                     const char *       name);
+
+int                ipcp_data_dir_add_entry(struct ipcp_data * data,
+                                           char *             name,
                                            uint64_t           addr);
 
-int                ipcp_data_del_dir_entry(struct ipcp_data * data,
-                                           const char *       ap_name,
+int                ipcp_data_dir_del_entry(struct ipcp_data * data,
+                                           const char *       name,
                                            uint64_t           addr);
 
-bool               ipcp_data_is_in_registry(struct ipcp_data * data,
-                                            const char *       name);
+bool               ipcp_data_dir_has(struct ipcp_data * data,
+                                     const char *       name);
+
+uint64_t           ipcp_data_dir_get_addr(struct ipcp_data * data,
+                                          const char *       name);
+
+struct dir_query * ipcp_data_dir_query_create(char * name);
+
+void               ipcp_data_dir_query_respond(struct dir_query * query);
 
-bool               ipcp_data_is_in_directory(struct ipcp_data * data,
-                                             const char *       ap_name);
+void               ipcp_data_dir_query_destroy(struct dir_query * query);
 
-uint64_t           ipcp_data_get_addr(struct ipcp_data * data,
-                                      const char *       ap_name);
+int                ipcp_data_dir_query_wait(struct dir_query *      query,
+                                            const struct timespec * timeout);
 #endif /* IPCPD_IPCP_DATA_H */
diff --git a/src/ipcpd/ipcp-ops.h b/src/ipcpd/ipcp-ops.h
index 815cda09..0b79a328 100644
--- a/src/ipcpd/ipcp-ops.h
+++ b/src/ipcpd/ipcp-ops.h
@@ -36,6 +36,8 @@ struct ipcp_ops {
 
         int   (* ipcp_name_unreg)(char * name);
 
+        int   (* ipcp_name_query)(char * name);
+
         int   (* ipcp_flow_alloc)(int           fd,
                                   char *        dst_ap_name,
                                   char *        src_ae_name,
diff --git a/src/ipcpd/ipcp.c b/src/ipcpd/ipcp.c
index c2d343f8..90fb94ef 100644
--- a/src/ipcpd/ipcp.c
+++ b/src/ipcpd/ipcp.c
@@ -20,7 +20,11 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+
+#define OUROBOROS_PREFIX "ipcpd/ipcp"
+
 #include <ouroboros/config.h>
+#include <ouroboros/logs.h>
 #include <ouroboros/time_utils.h>
 #include <ouroboros/utils.h>
 #include <ouroboros/sockets.h>
@@ -28,13 +32,11 @@
 #include <ouroboros/dev.h>
 #include <ouroboros/np1_flow.h>
 
-#define OUROBOROS_PREFIX "ipcpd/ipcp"
-#include <ouroboros/logs.h>
+#include "ipcp.h"
 
 #include <string.h>
 #include <sys/socket.h>
 #include <stdlib.h>
-#include "ipcp.h"
 
 int ipcp_init(enum ipcp_type type, struct ipcp_ops * ops)
 {
@@ -307,6 +309,15 @@ void * ipcp_main_loop(void * o)
                         ret_msg.result =
                                 ipcpi.ops->ipcp_name_unreg(msg->name);
                         break;
+                case IPCP_MSG_CODE__IPCP_NAME_QUERY:
+                        if (ipcpi.ops->ipcp_name_query == NULL) {
+                                LOG_ERR("Ap_query unsupported.");
+                                break;
+                        }
+                        ret_msg.has_result = true;
+                        ret_msg.result =
+                                ipcpi.ops->ipcp_name_query(msg->name);
+                        break;
                 case IPCP_MSG_CODE__IPCP_FLOW_ALLOC:
                         if (ipcpi.ops->ipcp_flow_alloc == NULL) {
                                 LOG_ERR("Flow_alloc unsupported.");
diff --git a/src/ipcpd/local/main.c b/src/ipcpd/local/main.c
index 192607c1..b8783d9d 100644
--- a/src/ipcpd/local/main.c
+++ b/src/ipcpd/local/main.c
@@ -20,17 +20,18 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#define OUROBOROS_PREFIX "ipcpd/local"
+
 #include <ouroboros/config.h>
-#include "ipcp.h"
+#include <ouroboros/logs.h>
 #include <ouroboros/errno.h>
 #include <ouroboros/dev.h>
 #include <ouroboros/fcntl.h>
 #include <ouroboros/fqueue.h>
 #include <ouroboros/ipcp-dev.h>
 #include <ouroboros/local-dev.h>
-#define OUROBOROS_PREFIX "ipcpd/local"
 
-#include <ouroboros/logs.h>
+#include "ipcp.h"
 
 #include <string.h>
 #include <signal.h>
@@ -176,7 +177,7 @@ static int ipcp_local_name_reg(char * name)
 {
         pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_data_add_reg_entry(ipcpi.data, name)) {
+        if (ipcp_data_reg_add_entry(ipcpi.data, name)) {
                 pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_DBG("Failed to add %s to local registry.", name);
                 return -1;
@@ -193,7 +194,7 @@ static int ipcp_local_name_unreg(char * name)
 {
         pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        ipcp_data_del_reg_entry(ipcpi.data, name);
+        ipcp_data_reg_del_entry(ipcpi.data, name);
 
         pthread_rwlock_unlock(&ipcpi.state_lock);
 
@@ -202,6 +203,19 @@ static int ipcp_local_name_unreg(char * name)
         return 0;
 }
 
+static int ipcp_local_name_query(char * name)
+{
+        int ret;
+
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+
+        ret = (ipcp_data_reg_has(ipcpi.data, name) ? 0 : -1);
+
+        pthread_rwlock_unlock(&ipcpi.state_lock);
+
+        return ret;
+}
+
 static int ipcp_local_flow_alloc(int           fd,
                                  char *        dst_name,
                                  char *        src_ae_name,
@@ -302,6 +316,7 @@ static struct ipcp_ops local_ops = {
         .ipcp_enroll          = NULL,                       /* shim */
         .ipcp_name_reg        = ipcp_local_name_reg,
         .ipcp_name_unreg      = ipcp_local_name_unreg,
+        .ipcp_name_query      = ipcp_local_name_query,
         .ipcp_flow_alloc      = ipcp_local_flow_alloc,
         .ipcp_flow_alloc_resp = ipcp_local_flow_alloc_resp,
         .ipcp_flow_dealloc    = ipcp_local_flow_dealloc
diff --git a/src/ipcpd/normal/main.c b/src/ipcpd/normal/main.c
index 32aabdf2..2402972f 100644
--- a/src/ipcpd/normal/main.c
+++ b/src/ipcpd/normal/main.c
@@ -28,6 +28,11 @@
 #include <ouroboros/ipcp-dev.h>
 #include <ouroboros/time_utils.h>
 
+#include "fmgr.h"
+#include "ribmgr.h"
+#include "ipcp.h"
+#include "frct.h"
+
 #include <stdbool.h>
 #include <signal.h>
 #include <stdlib.h>
@@ -35,11 +40,6 @@
 #include <string.h>
 #include <errno.h>
 
-#include "fmgr.h"
-#include "ribmgr.h"
-#include "ipcp.h"
-#include "frct.h"
-
 #define THIS_TYPE IPCP_NORMAL
 
 /* global for trapping signal */
@@ -72,7 +72,7 @@ static int normal_ipcp_name_reg(char * name)
 {
         pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_data_add_reg_entry(ipcpi.data, name)) {
+        if (ipcp_data_reg_add_entry(ipcpi.data, name)) {
                 pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Failed to add %s to local registry.", name);
                 return -1;
@@ -89,13 +89,28 @@ static int normal_ipcp_name_unreg(char * name)
 {
         pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        ipcp_data_del_reg_entry(ipcpi.data, name);
+        ipcp_data_reg_del_entry(ipcpi.data, name);
 
         pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
 
+static int normal_ipcp_name_query(char * name)
+{
+        LOG_MISSING;
+
+        (void) name;
+
+        /*
+         * NOTE: For the moment we just return -1,
+         * for testing purposes we may return zero here
+         * for certain names.
+         */
+
+        return -1;
+}
+
 static int normal_ipcp_enroll(char * dif_name)
 {
         struct timespec timeout = {(ENROLL_TIMEOUT / 1000),
@@ -165,6 +180,7 @@ static struct ipcp_ops normal_ops = {
         .ipcp_enroll          = normal_ipcp_enroll,
         .ipcp_name_reg        = normal_ipcp_name_reg,
         .ipcp_name_unreg      = normal_ipcp_name_unreg,
+        .ipcp_name_query      = normal_ipcp_name_query,
         .ipcp_flow_alloc      = fmgr_np1_alloc,
         .ipcp_flow_alloc_resp = fmgr_np1_alloc_resp,
         .ipcp_flow_dealloc    = fmgr_np1_dealloc
diff --git a/src/ipcpd/shim-eth-llc/main.c b/src/ipcpd/shim-eth-llc/main.c
index 6046d939..d4ea8eba 100644
--- a/src/ipcpd/shim-eth-llc/main.c
+++ b/src/ipcpd/shim-eth-llc/main.c
@@ -20,10 +20,11 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
-#include <ouroboros/config.h>
-
 #define _DEFAULT_SOURCE
 
+#define OUROBOROS_PREFIX "ipcpd/shim-eth-llc"
+
+#include <ouroboros/config.h>
 #include <ouroboros/errno.h>
 #include <ouroboros/list.h>
 #include <ouroboros/utils.h>
@@ -32,12 +33,10 @@
 #include <ouroboros/ipcp-dev.h>
 #include <ouroboros/fcntl.h>
 #include <ouroboros/fqueue.h>
-
-#define OUROBOROS_PREFIX "ipcpd/shim-eth-llc"
-
 #include <ouroboros/logs.h>
 
 #include "ipcp.h"
+#include "shim_eth_llc_messages.pb-c.h"
 
 #include <net/if.h>
 #include <signal.h>
@@ -65,8 +64,6 @@
 #include <poll.h>
 #include <sys/mman.h>
 
-#include "shim_eth_llc_messages.pb-c.h"
-
 typedef ShimEthLlcMsg shim_eth_llc_msg_t;
 
 #define THIS_TYPE IPCP_SHIM_ETH_LLC
@@ -80,6 +77,7 @@ typedef ShimEthLlcMsg shim_eth_llc_msg_t;
                         + SHIM_ETH_LLC_MAX_SDU_SIZE)
 
 #define EVENT_WAIT_TIMEOUT 100 /* us */
+#define NAME_QUERY_TIMEOUT 100000000 /* ns */
 
 /* global for trapping signal */
 int irmd_api;
@@ -313,6 +311,7 @@ static int eth_llc_ipcp_sap_alloc(uint8_t * dst_addr,
         shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
 
         msg.code        = SHIM_ETH_LLC_MSG_CODE__FLOW_REQ;
+        msg.has_ssap    = true;
         msg.ssap        = ssap;
         msg.dst_name    = dst_name;
         msg.src_ae_name = src_ae_name;
@@ -328,6 +327,7 @@ static int eth_llc_ipcp_sap_alloc_resp(uint8_t * dst_addr,
         shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
 
         msg.code         = SHIM_ETH_LLC_MSG_CODE__FLOW_REPLY;
+        msg.has_ssap     = true;
         msg.ssap         = ssap;
         msg.has_dsap     = true;
         msg.dsap         = dsap;
@@ -341,8 +341,9 @@ static int eth_llc_ipcp_sap_dealloc(uint8_t * dst_addr, uint8_t ssap)
 {
         shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
 
-        msg.code = SHIM_ETH_LLC_MSG_CODE__FLOW_DEALLOC;
-        msg.ssap = ssap;
+        msg.code     = SHIM_ETH_LLC_MSG_CODE__FLOW_DEALLOC;
+        msg.has_ssap = true;
+        msg.ssap     = ssap;
 
         return eth_llc_ipcp_send_mgmt_frame(&msg, dst_addr);
 }
@@ -438,6 +439,42 @@ static int eth_llc_ipcp_flow_dealloc_req(uint8_t ssap)
         return 0;
 }
 
+static int eth_llc_ipcp_name_query_req(char * name, uint8_t * r_addr)
+{
+        shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
+
+        if (ipcp_data_reg_has(ipcpi.data, name)) {
+                msg.code     = SHIM_ETH_LLC_MSG_CODE__NAME_QUERY_REPLY;
+                msg.dst_name = name;
+
+                eth_llc_ipcp_send_mgmt_frame(&msg, r_addr);
+        }
+
+        return 0;
+}
+
+static int eth_llc_ipcp_name_query_reply(char * name, uint8_t * r_addr)
+{
+        uint64_t address = 0;
+        struct list_head * pos;
+
+        memcpy(&address, r_addr, MAC_SIZE);
+
+        ipcp_data_dir_add_entry(ipcpi.data, name, address);
+
+        pthread_mutex_lock(&ipcpi.data->dir_queries_lock);
+        list_for_each(pos, &ipcpi.data->dir_queries) {
+                struct dir_query * e =
+                        list_entry(pos, struct dir_query, next);
+                if (strcmp(e->name, name) == 0) {
+                        ipcp_data_dir_query_respond(e);
+                }
+        }
+        pthread_mutex_unlock(&ipcpi.data->dir_queries_lock);
+
+        return 0;
+}
+
 static int eth_llc_ipcp_mgmt_frame(uint8_t * buf, size_t len, uint8_t * r_addr)
 {
         shim_eth_llc_msg_t * msg = shim_eth_llc_msg__unpack(NULL, len, buf);
@@ -448,7 +485,7 @@ static int eth_llc_ipcp_mgmt_frame(uint8_t * buf, size_t len, uint8_t * r_addr)
 
         switch (msg->code) {
         case SHIM_ETH_LLC_MSG_CODE__FLOW_REQ:
-                if (ipcp_data_is_in_registry(ipcpi.data, msg->dst_name)) {
+                if (ipcp_data_reg_has(ipcpi.data, msg->dst_name)) {
                         eth_llc_ipcp_sap_req(msg->ssap,
                                              r_addr,
                                              msg->dst_name,
@@ -464,6 +501,12 @@ static int eth_llc_ipcp_mgmt_frame(uint8_t * buf, size_t len, uint8_t * r_addr)
         case SHIM_ETH_LLC_MSG_CODE__FLOW_DEALLOC:
                 eth_llc_ipcp_flow_dealloc_req(msg->ssap);
                 break;
+        case SHIM_ETH_LLC_MSG_CODE__NAME_QUERY_REQ:
+                eth_llc_ipcp_name_query_req(msg->dst_name, r_addr);
+                break;
+        case SHIM_ETH_LLC_MSG_CODE__NAME_QUERY_REPLY:
+                eth_llc_ipcp_name_query_reply(msg->dst_name, r_addr);
+                break;
         default:
                 LOG_ERR("Unknown message received %d.", msg->code);
                 shim_eth_llc_msg__free_unpacked(msg, NULL);
@@ -854,7 +897,7 @@ static int eth_llc_ipcp_name_reg(char * name)
 {
         pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_data_add_reg_entry(ipcpi.data, name)) {
+        if (ipcp_data_reg_add_entry(ipcpi.data, name)) {
                 pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Failed to add %s to local registry.", name);
                 return -1;
@@ -871,13 +914,49 @@ static int eth_llc_ipcp_name_unreg(char * name)
 {
         pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        ipcp_data_del_reg_entry(ipcpi.data, name);
+        ipcp_data_reg_del_entry(ipcpi.data, name);
 
         pthread_rwlock_unlock(&ipcpi.state_lock);
 
         return 0;
 }
 
+static int eth_llc_ipcp_name_query(char * name)
+{
+        uint8_t r_addr[MAC_SIZE];
+        struct timespec timeout = {0, NAME_QUERY_TIMEOUT};
+        shim_eth_llc_msg_t msg = SHIM_ETH_LLC_MSG__INIT;
+        struct dir_query * query;
+        int ret;
+
+        if (ipcp_data_dir_has(ipcpi.data, name))
+                return 0;
+
+        msg.code     = SHIM_ETH_LLC_MSG_CODE__NAME_QUERY_REQ;
+        msg.dst_name = name;
+
+        memset(r_addr, 0xff, MAC_SIZE);
+
+        query = ipcp_data_dir_query_create(name);
+        if (query == NULL)
+                return -1;
+
+        pthread_mutex_lock(&ipcpi.data->dir_queries_lock);
+        list_add(&query->next, &ipcpi.data->dir_queries);
+        pthread_mutex_unlock(&ipcpi.data->dir_queries_lock);
+
+        eth_llc_ipcp_send_mgmt_frame(&msg, r_addr);
+
+        ret = ipcp_data_dir_query_wait(query, &timeout);
+
+        pthread_mutex_lock(&ipcpi.data->dir_queries_lock);
+        list_del(&query->next);
+        ipcp_data_dir_query_destroy(query);
+        pthread_mutex_unlock(&ipcpi.data->dir_queries_lock);
+
+        return ret;
+}
+
 static int eth_llc_ipcp_flow_alloc(int           fd,
                                    char *        dst_name,
                                    char *        src_ae_name,
@@ -885,6 +964,7 @@ static int eth_llc_ipcp_flow_alloc(int           fd,
 {
         uint8_t ssap = 0;
         uint8_t r_addr[MAC_SIZE];
+        uint64_t addr = 0;
 
         LOG_DBG("Allocating flow to %s.", dst_name);
 
@@ -902,6 +982,13 @@ static int eth_llc_ipcp_flow_alloc(int           fd,
                 return -1; /* -ENOTENROLLED */
         }
 
+        if (!ipcp_data_dir_has(ipcpi.data, dst_name)) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+                LOG_ERR("Destination unreachable.");
+                return -1;
+        }
+        addr = ipcp_data_dir_get_addr(ipcpi.data, dst_name);
+
         pthread_rwlock_wrlock(&eth_llc_data.flows_lock);
 
         ssap =  bmp_allocate(eth_llc_data.saps);
@@ -917,7 +1004,7 @@ static int eth_llc_ipcp_flow_alloc(int           fd,
         pthread_rwlock_unlock(&eth_llc_data.flows_lock);
         pthread_rwlock_unlock(&ipcpi.state_lock);
 
-        memset(r_addr, 0xff, MAC_SIZE);
+        memcpy(r_addr, &addr, MAC_SIZE);
 
         if (eth_llc_ipcp_sap_alloc(r_addr,
                                    ssap,
@@ -1025,6 +1112,7 @@ static struct ipcp_ops eth_llc_ops = {
         .ipcp_enroll          = NULL,
         .ipcp_name_reg        = eth_llc_ipcp_name_reg,
         .ipcp_name_unreg      = eth_llc_ipcp_name_unreg,
+        .ipcp_name_query      = eth_llc_ipcp_name_query,
         .ipcp_flow_alloc      = eth_llc_ipcp_flow_alloc,
         .ipcp_flow_alloc_resp = eth_llc_ipcp_flow_alloc_resp,
         .ipcp_flow_dealloc    = eth_llc_ipcp_flow_dealloc
diff --git a/src/ipcpd/shim-eth-llc/shim_eth_llc_messages.proto b/src/ipcpd/shim-eth-llc/shim_eth_llc_messages.proto
index 0e8a1ce2..4d027d98 100644
--- a/src/ipcpd/shim-eth-llc/shim_eth_llc_messages.proto
+++ b/src/ipcpd/shim-eth-llc/shim_eth_llc_messages.proto
@@ -1,14 +1,16 @@
 enum shim_eth_llc_msg_code {
-        FLOW_REQ     = 1;
-        FLOW_REPLY   = 2;
-        FLOW_DEALLOC = 3;
+        FLOW_REQ         = 1;
+        FLOW_REPLY       = 2;
+        FLOW_DEALLOC     = 3;
+        NAME_QUERY_REQ   = 4;
+        NAME_QUERY_REPLY = 5;
 };
 
 message shim_eth_llc_msg {
         required shim_eth_llc_msg_code code  = 1;
         optional string dst_name             = 2;
         optional string src_ae_name          = 3;
-        required uint32 ssap                 = 4;
+        optional uint32 ssap                 = 4;
         optional uint32 dsap                 = 5;
         optional sint32 response             = 6;
 };
diff --git a/src/ipcpd/shim-udp/main.c b/src/ipcpd/shim-udp/main.c
index 62e1b2d0..f779713c 100644
--- a/src/ipcpd/shim-udp/main.c
+++ b/src/ipcpd/shim-udp/main.c
@@ -20,9 +20,9 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#define OUROBOROS_PREFIX "ipcpd/shim-udp"
+
 #include <ouroboros/config.h>
-#include "ipcp.h"
-#include "shim_udp_config.h"
 #include <ouroboros/list.h>
 #include <ouroboros/utils.h>
 #include <ouroboros/dev.h>
@@ -30,11 +30,12 @@
 #include <ouroboros/fqueue.h>
 #include <ouroboros/fcntl.h>
 #include <ouroboros/errno.h>
-
-#define OUROBOROS_PREFIX "ipcpd/shim-udp"
-
 #include <ouroboros/logs.h>
 
+#include "shim_udp_messages.pb-c.h"
+#include "ipcp.h"
+#include "shim_udp_config.h"
+
 #include <string.h>
 #include <sys/socket.h>
 #include <sys/select.h>
@@ -47,8 +48,6 @@
 #include <sys/wait.h>
 #include <fcntl.h>
 
-#include "shim_udp_messages.pb-c.h"
-
 typedef ShimUdpMsg shim_udp_msg_t;
 
 #define THIS_TYPE IPCP_SHIM_UDP
@@ -833,7 +832,7 @@ static int ipcp_udp_name_reg(char * name)
 
         pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        if (ipcp_data_add_reg_entry(ipcpi.data, name)) {
+        if (ipcp_data_reg_add_entry(ipcpi.data, name)) {
                 pthread_rwlock_unlock(&ipcpi.state_lock);
                 LOG_ERR("Failed to add %s to local registry.", name);
                 return -1;
@@ -864,7 +863,7 @@ static int ipcp_udp_name_reg(char * name)
 
                 if (ddns_send(cmd)) {
                         pthread_rwlock_rdlock(&ipcpi.state_lock);
-                        ipcp_data_del_reg_entry(ipcpi.data, name);
+                        ipcp_data_reg_del_entry(ipcpi.data, name);
                         pthread_rwlock_unlock(&ipcpi.state_lock);
                         return -1;
                 }
@@ -885,7 +884,6 @@ static int ipcp_udp_name_unreg(char * name)
         char cmd[100];
         uint32_t dns_addr;
 #endif
-
         if (strlen(name) > 24) {
                 LOG_ERR("DNS names cannot be longer than 24 chars.");
                 return -1;
@@ -914,7 +912,74 @@ static int ipcp_udp_name_unreg(char * name)
 
         pthread_rwlock_rdlock(&ipcpi.state_lock);
 
-        ipcp_data_del_reg_entry(ipcpi.data, name);
+        ipcp_data_reg_del_entry(ipcpi.data, name);
+
+        pthread_rwlock_unlock(&ipcpi.state_lock);
+
+        return 0;
+}
+
+static int ipcp_udp_name_query(char * name)
+{
+        uint32_t           ip_addr = 0;
+        struct hostent *   h;
+#ifdef CONFIG_OUROBOROS_ENABLE_DNS
+        uint32_t           dns_addr = 0;
+#endif
+
+        assert(name);
+
+        if (strlen(name) > 24) {
+                LOG_ERR("DNS names cannot be longer than 24 chars.");
+                return -1;
+        }
+
+        pthread_rwlock_rdlock(&ipcpi.state_lock);
+
+        if (ipcp_get_state() != IPCP_ENROLLED) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+                LOG_DBG("Won't query a name on a non-enrolled IPCP.");
+                return -1; /* -ENOTENROLLED */
+        }
+
+#ifdef CONFIG_OUROBOROS_ENABLE_DNS
+        dns_addr = udp_data.dns_addr;
+
+        if (dns_addr != 0) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+
+                ip_addr = ddns_resolve(name, dns_addr);
+                if (ip_addr == 0) {
+                        LOG_DBG("Could not resolve %s.", name);
+                        return -1;
+                }
+
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
+
+                if (ipcp_get_state() != IPCP_ENROLLED) {
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
+                        LOG_DBG("Won't add name to the directory.");
+                        return -1; /* -ENOTENROLLED */
+                }
+        } else {
+#endif
+                h = gethostbyname(name);
+                if (h == NULL) {
+                        pthread_rwlock_unlock(&ipcpi.state_lock);
+                        LOG_DBG("Could not resolve %s.", name);
+                        return -1;
+                }
+
+                ip_addr = *((uint32_t *) (h->h_addr_list[0]));
+#ifdef CONFIG_OUROBOROS_ENABLE_DNS
+        }
+#endif
+
+        if (ipcp_data_dir_add_entry(ipcpi.data, name, ip_addr)) {
+                pthread_rwlock_unlock(&ipcpi.state_lock);
+                LOG_ERR("Failed to add directory entry.");
+                return -1;
+        }
 
         pthread_rwlock_unlock(&ipcpi.state_lock);
 
@@ -930,15 +995,13 @@ static int ipcp_udp_flow_alloc(int           fd,
         struct sockaddr_in f_saddr; /* flow */
         socklen_t          f_saddr_len = sizeof(f_saddr);
         int                skfd;
-        struct hostent *   h;
         uint32_t           ip_addr = 0;
-#ifdef CONFIG_OUROBOROS_ENABLE_DNS
-        uint32_t           dns_addr = 0;
-#endif
+
         LOG_DBG("Allocating flow to %s.", dst_name);
 
         if (dst_name == NULL || src_ae_name == NULL)
                 return -1;
+
         if (strlen(dst_name) > 255
             || strlen(src_ae_name) > 255) {
                 LOG_ERR("Name too long for this shim.");
@@ -976,39 +1039,13 @@ static int ipcp_udp_flow_alloc(int           fd,
                 return -1; /* -ENOTENROLLED */
         }
 
-#ifdef CONFIG_OUROBOROS_ENABLE_DNS
-        dns_addr = udp_data.dns_addr;
-
-        if (dns_addr != 0) {
+        if (!ipcp_data_dir_has(ipcpi.data, dst_name)) {
                 pthread_rwlock_unlock(&ipcpi.state_lock);
-
-                ip_addr = ddns_resolve(dst_name, dns_addr);
-                if (ip_addr == 0) {
-                        LOG_DBG("Could not resolve %s.", dst_name);
-                        close(fd);
-                        return -1;
-                }
-
-                pthread_rwlock_rdlock(&ipcpi.state_lock);
-                if (ipcp_get_state() != IPCP_ENROLLED) {
-                        pthread_rwlock_unlock(&ipcpi.state_lock);
-                        LOG_DBG("Won't allocate flow with non-enrolled IPCP.");
-                        close(skfd);
-                        return -1; /* -ENOTENROLLED */
-                }
-        } else {
-#endif
-                h = gethostbyname(dst_name);
-                if (h == NULL) {
-                        LOG_DBG("Could not resolve %s.", dst_name);
-                        close(skfd);
-                        return -1;
-                }
-
-                ip_addr = *((uint32_t *) (h->h_addr_list[0]));
-#ifdef CONFIG_OUROBOROS_ENABLE_DNS
+                LOG_DBG("Could not resolve destination.");
+                close(skfd);
+                return -1;
         }
-#endif
+        ip_addr = (uint32_t) ipcp_data_dir_get_addr(ipcpi.data, dst_name);
 
         /* connect to server (store the remote IP address in the fd) */
         memset((char *) &r_saddr, 0, sizeof(r_saddr));
@@ -1171,6 +1208,7 @@ static struct ipcp_ops udp_ops = {
         .ipcp_enroll          = NULL,                       /* shim */
         .ipcp_name_reg        = ipcp_udp_name_reg,
         .ipcp_name_unreg      = ipcp_udp_name_unreg,
+        .ipcp_name_query      = ipcp_udp_name_query,
         .ipcp_flow_alloc      = ipcp_udp_flow_alloc,
         .ipcp_flow_alloc_resp = ipcp_udp_flow_alloc_resp,
         .ipcp_flow_dealloc    = ipcp_udp_flow_dealloc
diff --git a/src/irmd/ipcp.c b/src/irmd/ipcp.c
index 33f7650a..29327df4 100644
--- a/src/irmd/ipcp.c
+++ b/src/irmd/ipcp.c
@@ -20,15 +20,14 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#define OUROBOROS_PREFIX "irmd/ipcp"
+
 #include <ouroboros/config.h>
+#include <ouroboros/logs.h>
 #include <ouroboros/errno.h>
 #include <ouroboros/utils.h>
 #include <ouroboros/sockets.h>
 
-#define OUROBOROS_PREFIX "irmd/ipcp"
-
-#include <ouroboros/logs.h>
-
 #include "ipcp.h"
 
 #include <stdlib.h>
@@ -302,6 +301,31 @@ int ipcp_name_unreg(pid_t  api,
         return ret;
 }
 
+int ipcp_name_query(pid_t api,
+                    char * name)
+{
+        ipcp_msg_t msg = IPCP_MSG__INIT;
+        ipcp_msg_t * recv_msg = NULL;
+        int ret = -1;
+
+        msg.code = IPCP_MSG_CODE__IPCP_NAME_QUERY;
+        msg.name = name;
+
+        recv_msg = send_recv_ipcp_msg(api, &msg);
+        if (recv_msg == NULL)
+                return -1;
+
+        if (recv_msg->has_result == false) {
+                ipcp_msg__free_unpacked(recv_msg, NULL);
+                return -1;
+        }
+
+        ret = recv_msg->result;
+        ipcp_msg__free_unpacked(recv_msg, NULL);
+
+        return ret;
+}
+
 int ipcp_flow_alloc(pid_t         api,
                     int           port_id,
                     pid_t         n_api,
diff --git a/src/irmd/ipcp.h b/src/irmd/ipcp.h
index 930695fa..67b14ece 100644
--- a/src/irmd/ipcp.h
+++ b/src/irmd/ipcp.h
@@ -44,6 +44,8 @@ int   ipcp_name_reg(pid_t  api,
                     char * name);
 int   ipcp_name_unreg(pid_t  api,
                       char * name);
+int   ipcp_name_query(pid_t api,
+                      char * name);
 
 int   ipcp_flow_alloc(pid_t         api,
                       int           port_id,
diff --git a/src/irmd/main.c b/src/irmd/main.c
index 3884a9a7..aac47adb 100644
--- a/src/irmd/main.c
+++ b/src/irmd/main.c
@@ -21,6 +21,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#define OUROBOROS_PREFIX "irmd"
+
 #include <ouroboros/config.h>
 #include <ouroboros/errno.h>
 #include <ouroboros/sockets.h>
@@ -33,9 +35,6 @@
 #include <ouroboros/bitmap.h>
 #include <ouroboros/qos.h>
 #include <ouroboros/time_utils.h>
-
-#define OUROBOROS_PREFIX "irmd"
-
 #include <ouroboros/logs.h>
 
 #include "utils.h"
@@ -170,52 +169,45 @@ static struct ipcp_entry * get_ipcp_entry_by_api(pid_t api)
         return NULL;
 }
 
-/* FIXME: Check if the name exists anywhere in a DIF. */
+/* Check if the name exists anywhere in a DIF. */
 static pid_t get_ipcp_by_dst_name(char * dst_name)
 {
         struct list_head * p = NULL;
-        char * dif_name =
-                registry_get_dif_for_dst(&irmd->registry, dst_name);
-        if (dif_name == NULL) {
-                list_for_each(p, &irmd->ipcps) {
-                        struct ipcp_entry * e =
-                                list_entry(p, struct ipcp_entry, next);
-                        if (e->type == IPCP_NORMAL) {
-                                dif_name = e->dif_name;
-                                break;
-                        }
-                }
 
-                list_for_each(p, &irmd->ipcps) {
-                        struct ipcp_entry * e =
-                                list_entry(p, struct ipcp_entry, next);
-                        if (e->type == IPCP_SHIM_ETH_LLC) {
-                                dif_name = e->dif_name;
-                                break;
-                        }
+        list_for_each(p, &irmd->ipcps) {
+                struct ipcp_entry * e =
+                        list_entry(p, struct ipcp_entry, next);
+                if (e->type == IPCP_LOCAL) {
+                        if (ipcp_name_query(e->api, dst_name) == 0)
+                                return e->api;
                 }
+        }
 
-
-                list_for_each(p, &irmd->ipcps) {
-                        struct ipcp_entry * e =
-                                list_entry(p, struct ipcp_entry, next);
-                        if (e->type == IPCP_SHIM_UDP) {
-                                dif_name = e->dif_name;
-                                break;
-                        }
+        list_for_each(p, &irmd->ipcps) {
+                struct ipcp_entry * e =
+                        list_entry(p, struct ipcp_entry, next);
+                if (e->type == IPCP_NORMAL) {
+                        if (ipcp_name_query(e->api, dst_name) == 0)
+                                return e->api;
                 }
         }
 
-        if (dif_name == NULL)
-                return -1;
-
         list_for_each(p, &irmd->ipcps) {
-                struct ipcp_entry * e = list_entry(p, struct ipcp_entry, next);
-                if (e->dif_name == NULL)
-                        continue;
+                struct ipcp_entry * e =
+                        list_entry(p, struct ipcp_entry, next);
+                if (e->type == IPCP_SHIM_ETH_LLC) {
+                        if (ipcp_name_query(e->api, dst_name) == 0)
+                                return e->api;
+                }
+        }
 
-                if (strcmp(e->dif_name, dif_name) == 0)
-                        return e->api;
+        list_for_each(p, &irmd->ipcps) {
+                struct ipcp_entry * e =
+                        list_entry(p, struct ipcp_entry, next);
+                if (e->type == IPCP_SHIM_UDP) {
+                        if (ipcp_name_query(e->api, dst_name) == 0)
+                                return e->api;
+                }
         }
 
         return -1;
@@ -1136,6 +1128,18 @@ static struct irm_flow * flow_alloc(pid_t  api,
                 return NULL;
         }
 
+        pthread_rwlock_rdlock(&irmd->reg_lock);
+
+        ipcp = get_ipcp_by_dst_name(dst_name);
+        if (ipcp == -1) {
+                pthread_rwlock_unlock(&irmd->reg_lock);
+                pthread_rwlock_unlock(&irmd->state_lock);
+                LOG_INFO("Destination unreachable.");
+                return NULL;
+        }
+
+        pthread_rwlock_unlock(&irmd->reg_lock);
+
         f = irm_flow_create();
         if (f == NULL) {
                 pthread_rwlock_unlock(&irmd->state_lock);
@@ -1149,17 +1153,6 @@ static struct irm_flow * flow_alloc(pid_t  api,
         if (clock_gettime(CLOCK_MONOTONIC, &f->t0) < 0)
                 LOG_WARN("Failed to set timestamp.");
 
-        pthread_rwlock_rdlock(&irmd->reg_lock);
-
-        ipcp = get_ipcp_by_dst_name(dst_name);
-        if (ipcp == -1) {
-                pthread_rwlock_unlock(&irmd->reg_lock);
-                pthread_rwlock_unlock(&irmd->state_lock);
-                LOG_INFO("Destination unreachable.");
-                return NULL;
-        }
-
-        pthread_rwlock_unlock(&irmd->reg_lock);
         pthread_rwlock_wrlock(&irmd->flows_lock);
 
         port_id = f->port_id = bmp_allocate(irmd->port_ids);
diff --git a/src/irmd/registry.c b/src/irmd/registry.c
index 9442f3db..07ec370c 100644
--- a/src/irmd/registry.c
+++ b/src/irmd/registry.c
@@ -20,15 +20,16 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
-#include "registry.h"
-#include "utils.h"
-
 #define OUROBOROS_PREFIX "registry"
 
+#include <ouroboros/config.h>
 #include <ouroboros/errno.h>
 #include <ouroboros/logs.h>
 #include <ouroboros/irm_config.h>
 
+#include "registry.h"
+#include "utils.h"
+
 #include <stdlib.h>
 #include <stdbool.h>
 #include <string.h>
@@ -405,44 +406,6 @@ void registry_del_api(struct list_head * registry,
         return;
 }
 
-char * registry_get_dif_for_dst(struct list_head * registry,
-                                char *             dst_name)
-{
-        struct list_head * pos = NULL;
-        struct reg_entry * re =
-                registry_get_entry(registry, dst_name);
-
-        if (re != NULL) { /* local AP */
-                list_for_each(pos, &re->difs) {
-                        struct reg_dif  * rd =
-                                list_entry(pos, struct reg_dif, next);
-                        if (rd->type == IPCP_LOCAL)
-                                return rd->dif_name;
-                }
-
-                list_for_each(pos, &re->difs) {
-                        struct reg_dif * rd =
-                                list_entry(pos, struct reg_dif, next);
-                        if (rd->type == IPCP_NORMAL)
-                                return rd->dif_name;
-                }
-
-                list_for_each(pos, &re->difs) {
-                        struct reg_dif * rd =
-                                list_entry(pos, struct reg_dif, next);
-                        if (rd->type == IPCP_SHIM_UDP)
-                                return rd->dif_name;
-                }
-
-                LOG_DBG("Could not find DIF for %s.", dst_name);
-
-                return NULL;
-        } else {
-                LOG_DBG("No local ap %s found.", dst_name);
-                return NULL;
-        }
-}
-
 int registry_add_name_to_dif(struct list_head * registry,
                              char *             name,
                              char *             dif_name,
diff --git a/src/irmd/registry.h b/src/irmd/registry.h
index 35c4c10b..10cb12e8 100644
--- a/src/irmd/registry.h
+++ b/src/irmd/registry.h
@@ -27,15 +27,15 @@
 #include <ouroboros/list.h>
 #include <ouroboros/irm_config.h>
 
+#include "api_table.h"
+#include "apn_table.h"
+
 #include <stdint.h>
 #include <stdbool.h>
 #include <pthread.h>
 #include <string.h>
 #include <sys/types.h>
 
-#include "api_table.h"
-#include "apn_table.h"
-
 #define registry_has_name(r, name) \
         (registry_get_entry(r, name) != NULL)
 
@@ -99,9 +99,6 @@ void               registry_sanitize_apis(struct list_head * registry);
 struct reg_entry * registry_get_entry(struct list_head * registry,
                                       char *             name);
 
-char *             registry_get_dif_for_dst(struct list_head * registry,
-                                            char *             dst_name);
-
 int                registry_add_name_to_dif(struct list_head * registry,
                                             char *             name,
                                             char *             dif_name,
diff --git a/src/lib/ipcpd_messages.proto b/src/lib/ipcpd_messages.proto
index f64b6882..147d40c6 100644
--- a/src/lib/ipcpd_messages.proto
+++ b/src/lib/ipcpd_messages.proto
@@ -5,10 +5,11 @@ enum ipcp_msg_code {
         IPCP_ENROLL          =  2;
         IPCP_NAME_REG        =  3;
         IPCP_NAME_UNREG      =  4;
-        IPCP_FLOW_ALLOC      =  5;
-        IPCP_FLOW_ALLOC_RESP =  6;
-        IPCP_FLOW_DEALLOC    =  7;
-        IPCP_REPLY           =  8;
+        IPCP_NAME_QUERY      =  5;
+        IPCP_FLOW_ALLOC      =  6;
+        IPCP_FLOW_ALLOC_RESP =  7;
+        IPCP_FLOW_DEALLOC    =  8;
+        IPCP_REPLY           =  9;
 };
 
 message ipcp_msg {