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.

5 files changed, 79 insertions, 100 deletions

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,