-add gns record plugin for messenger room entries

Signed-off-by: TheJackiMonster <thejackimonster@gmail.com>

4 files changed, 287 insertions, 0 deletions

diff --git a/src/include/gnu_name_system_record_types.h b/src/include/gnu_name_system_record_types.h
index b2cf45dc8..22b2c472e 100644
--- a/src/include/gnu_name_system_record_types.h
+++ b/src/include/gnu_name_system_record_types.h
@@ -127,6 +127,16 @@ extern "C" {
  */
 #define GNUNET_GNSRECORD_TYPE_EDKEY 65556
 
+/**
+ * Encoding for Robust Immutable Storage (ERIS) binary read capability
+ */
+#define GNUNET_GNSRECORD_TYPE_ERIS_READ_CAPABILITY 65557
+
+/**
+ * Record type to share an entry of a messenger room
+ */
+#define GNUNET_GNSRECORD_TYPE_MESSENGER_ROOM_ENTRY 65558
+
 
 #if 0 /* keep Emacsens' auto-indent happy */
 {
diff --git a/src/include/gnunet_messenger_service.h b/src/include/gnunet_messenger_service.h
index b54567aa7..96d48b411 100644
--- a/src/include/gnunet_messenger_service.h
+++ b/src/include/gnunet_messenger_service.h
@@ -75,6 +75,27 @@ struct GNUNET_MESSENGER_Room;
  */
 struct GNUNET_MESSENGER_Contact;
 
+GNUNET_NETWORK_STRUCT_BEGIN
+
+/**
+ * A room entry record specifies which peer is hosting a given room and
+ * may also specify the key to enter it.
+ */
+struct GNUNET_MESSENGER_RoomEntryRecord
+{
+  /**
+   * The peer identity of an open door to a room.
+   */
+  struct GNUNET_PeerIdentity door;
+
+  /**
+   * The hash identifying the port of the room.
+   */
+  struct GNUNET_HashCode key;
+};
+
+GNUNET_NETWORK_STRUCT_END
+
 /**
  * Enum for the different supported kinds of messages
  */
diff --git a/src/messenger/Makefile.am b/src/messenger/Makefile.am
index 3fc532e7e..4be11f3aa 100644
--- a/src/messenger/Makefile.am
+++ b/src/messenger/Makefile.am
@@ -10,6 +10,19 @@ pkgcfgdir= $(pkgdatadir)/config.d/
 
 libexecdir= $(pkglibdir)/libexec/
 
+plugin_LTLIBRARIES = \
+  libgnunet_plugin_gnsrecord_messenger.la
+
+
+libgnunet_plugin_gnsrecord_messenger_la_SOURCES = \
+  plugin_gnsrecord_messenger.c
+libgnunet_plugin_gnsrecord_messenger_la_LIBADD = \
+  $(top_builddir)/src/util/libgnunetutil.la \
+  $(LTLIBINTL)
+libgnunet_plugin_gnsrecord_messenger_la_LDFLAGS = \
+ $(GN_PLUGIN_LDFLAGS)
+
+
 pkgcfg_DATA = \
   messenger.conf
 
diff --git a/src/messenger/plugin_gnsrecord_messenger.c b/src/messenger/plugin_gnsrecord_messenger.c
new file mode 100644
index 000000000..2219f0bde
--- /dev/null
+++ b/src/messenger/plugin_gnsrecord_messenger.c
@@ -0,0 +1,243 @@
+/*
+   This file is part of GNUnet.
+   Copyright (C) 2021 GNUnet e.V.
+
+   GNUnet is free software: you can redistribute it and/or modify it
+   under the terms of the GNU Affero General Public License as published
+   by the Free Software Foundation, either version 3 of the License,
+   or (at your option) any later version.
+
+   GNUnet is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+   SPDX-License-Identifier: AGPL3.0-or-later
+ */
+/**
+ * @author Tobias Frisch
+ * @file src/messenger/plugin_gnsrecord_messenger.c
+ * @brief Plugin to provide the API for useful GNS records to improve
+ *        the usability of the messenger service.
+ */
+
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_gnsrecord_lib.h"
+#include "gnunet_messenger_service.h"
+#include "gnunet_gnsrecord_plugin.h"
+
+
+/**
+ * Convert the 'value' of a record to a string.
+ *
+ * @param cls closure, unused
+ * @param type type of the record
+ * @param data value in binary encoding
+ * @param data_size number of bytes in @a data
+ * @return NULL on error, otherwise human-readable representation of the value
+ */
+static char *
+messenger_value_to_string (void *cls,
+                           uint32_t type,
+                           const void *data,
+                           size_t data_size)
+{
+  (void) cls;
+  switch (type)
+  {
+  case GNUNET_GNSRECORD_TYPE_MESSENGER_ROOM_ENTRY:
+    {
+      if (data_size != sizeof(struct GNUNET_MESSENGER_RoomEntryRecord))
+      {
+        GNUNET_break_op (0);
+        return NULL;
+      }
+
+      const struct GNUNET_MESSENGER_RoomEntryRecord *record = data;
+
+      char *door = GNUNET_CRYPTO_eddsa_public_key_to_string (&(record->door.public_key));
+      char *key = GNUNET_STRINGS_data_to_string_alloc (&(record->key), sizeof(struct GNUNET_HashCode));
+
+      char *ret;
+      GNUNET_asprintf (&ret, "%s-%s", door, key);
+      GNUNET_free (key);
+      GNUNET_free (door);
+      return ret;
+    }
+
+  default:
+    return NULL;
+  }
+}
+
+
+/**
+ * Convert human-readable version of a 'value' of a record to the binary
+ * representation.
+ *
+ * @param cls closure, unused
+ * @param type type of the record
+ * @param s human-readable string
+ * @param data set to value in binary encoding (will be allocated)
+ * @param data_size set to number of bytes in @a data
+ * @return #GNUNET_OK on success
+ */
+static int
+messenger_string_to_value (void *cls,
+                           uint32_t type,
+                           const char *s,
+                           void **data,
+                           size_t *data_size)
+{
+  (void) cls;
+  if (NULL == s)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+
+  switch (type)
+  {
+  case GNUNET_GNSRECORD_TYPE_MESSENGER_ROOM_ENTRY:
+    {
+      char key [103];
+      const char *dash;
+      struct GNUNET_PeerIdentity door;
+
+      if ((NULL == (dash = strchr (s, '-'))) ||
+          (1 != sscanf (s, "%103s-", key)) ||
+          (GNUNET_OK != GNUNET_CRYPTO_eddsa_public_key_from_string (dash + 1,
+                                                                    strlen (dash + 1),
+                                                                    &(door.public_key))))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                    _ ("Unable to parse MESSENGER_ROOM_ENTRY record `%s'\n"),
+                    s);
+        return GNUNET_SYSERR;
+      }
+
+      struct GNUNET_MESSENGER_RoomEntryRecord *record = GNUNET_new (
+          struct GNUNET_MESSENGER_RoomEntryRecord
+      );
+
+      if (GNUNET_OK != GNUNET_STRINGS_string_to_data (key,
+                                                      strlen (key),
+                                                      &(record->key),
+                                                      sizeof(struct GNUNET_HashCode)))
+      {
+        GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                    _ ("Unable to parse MESSENGER_ROOM_ENTRY record `%s'\n"),
+                    s);
+        GNUNET_free (record);
+        return GNUNET_SYSERR;
+      }
+
+      record->door = door;
+      *data = record;
+      *data_size = sizeof(struct GNUNET_MESSENGER_RoomEntryRecord);
+      return GNUNET_OK;
+    }
+
+  default:
+    return GNUNET_SYSERR;
+  }
+}
+
+
+/**
+ * Mapping of record type numbers to human-readable
+ * record type names.
+ */
+static struct
+{
+  const char *name;
+  uint32_t number;
+} name_map[] = {
+  { "MESSENGER_ROOM_ENTRY", GNUNET_GNSRECORD_TYPE_MESSENGER_ROOM_ENTRY },
+  { NULL, UINT32_MAX }
+};
+
+
+/**
+ * Convert a type name (e.g. "AAAA") to the corresponding number.
+ *
+ * @param cls closure, unused
+ * @param gns_typename name to convert
+ * @return corresponding number, UINT32_MAX on error
+ */
+static uint32_t
+messenger_typename_to_number (void *cls,
+                              const char *gns_typename)
+{
+  unsigned int i;
+
+  (void) cls;
+  i = 0;
+  while ((name_map[i].name != NULL) &&
+         (0 != strcasecmp (gns_typename, name_map[i].name)))
+    i++;
+  return name_map[i].number;
+}
+
+
+/**
+ * Convert a type number to the corresponding type string (e.g. 1 to "A")
+ *
+ * @param cls closure, unused
+ * @param type number of a type to convert
+ * @return corresponding typestring, NULL on error
+ */
+static const char *
+messenger_number_to_typename (void *cls,
+                              uint32_t type)
+{
+  unsigned int i;
+
+  (void) cls;
+  i = 0;
+  while ((name_map[i].name != NULL) &&
+         (type != name_map[i].number))
+    i++;
+  return name_map[i].name;
+}
+
+
+/**
+ * Entry point for the plugin.
+ *
+ * @param cls NULL
+ * @return the exported block API
+ */
+void *
+libgnunet_plugin_gnsrecord_messenger_init (void *cls)
+{
+  struct GNUNET_GNSRECORD_PluginFunctions *api;
+
+  (void) cls;
+  api = GNUNET_new (struct GNUNET_GNSRECORD_PluginFunctions);
+  api->value_to_string = &messenger_value_to_string;
+  api->string_to_value = &messenger_string_to_value;
+  api->typename_to_number = &messenger_typename_to_number;
+  api->number_to_typename = &messenger_number_to_typename;
+  return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ *
+ * @param cls the return value from #libgnunet_plugin_block_test_init
+ * @return NULL
+ */
+void *
+libgnunet_plugin_gnsrecord_messenger_done (void *cls)
+{
+  struct GNUNET_GNSRECORD_PluginFunctions *api = cls;
+
+  GNUNET_free (api);
+  return NULL;
+}