[PATCH 10/16] dpp: replace PKEX agent with generic DPP agent

[James Prestwood <prestwoj@gmail.com>]

This is one of two commits which replaces the existing shared code
agent with a generic DPP agent. This commit alone breaks DPP PKEX
but the next will fully remove the PKEX agent in place of the new
generic agent.

This is being done to prepare for enterprise DPP configuration where
additional agent APIs will be needed. Rather than invent a new
agent type it makes sense to bundle both into one and just define
separate methods, PKEX/Enterprise.
---
 src/dpp.c | 168 +++++++++++++++++++++++++++++++++++-------------------
 src/dpp.h |  24 ++++++++
 2 files changed, 133 insertions(+), 59 deletions(-)
 create mode 100644 src/dpp.h

diff --git a/src/dpp.c b/src/dpp.c
index 3ad60188..7b700018 100644
--- a/src/dpp.c
+++ b/src/dpp.c
@@ -54,6 +54,7 @@
 #include "src/handshake.h"
 #include "src/nl80211util.h"
 #include "src/knownnetworks.h"
+#include "src/dpp.h"
 
 #define DPP_FRAME_MAX_RETRIES 5
 #define DPP_FRAME_RETRY_TIMEOUT 1
@@ -81,6 +82,10 @@ static uint32_t unicast_watch;
 
 static uint8_t dpp_prefix[] = { 0x04, 0x09, 0x50, 0x6f, 0x9a, 0x1a, 0x01 };
 
+static char *dpp_agent_name;
+static char *dpp_agent_path;
+static unsigned int dpp_agent_watch;
+
 enum dpp_state {
 	DPP_STATE_NOTHING,
 	DPP_STATE_PRESENCE,
@@ -134,6 +139,7 @@ struct dpp_sm {
 	enum dpp_state state;
 	enum dpp_interface interface;
 
+	uint32_t agent_request_id;
 	struct pkex_agent *agent;
 
 	/*
@@ -373,64 +379,6 @@ static void dpp_free_pending_pkex_data(struct dpp_sm *dpp)
 	}
 }
 
-static void pkex_agent_free(void *data)
-{
-	struct pkex_agent *agent = data;
-
-	l_free(agent->owner);
-	l_free(agent->path);
-	l_dbus_remove_watch(dbus_get_bus(), agent->disconnect_watch);
-	l_free(agent);
-}
-
-static void dpp_agent_cancel(struct dpp_sm *dpp)
-{
-	struct l_dbus_message *msg;
-
-	const char *reason = "shutdown";
-
-	msg = l_dbus_message_new_method_call(dbus_get_bus(),
-						dpp->agent->owner,
-						dpp->agent->path,
-						IWD_SHARED_CODE_AGENT_INTERFACE,
-						"Cancel");
-	l_dbus_message_set_arguments(msg, "s", reason);
-	l_dbus_message_set_no_reply(msg, true);
-	l_dbus_send(dbus_get_bus(), msg);
-}
-
-static void dpp_agent_release(struct dpp_sm *dpp)
-{
-	struct l_dbus_message *msg;
-
-	msg = l_dbus_message_new_method_call(dbus_get_bus(),
-						dpp->agent->owner,
-						dpp->agent->path,
-						IWD_SHARED_CODE_AGENT_INTERFACE,
-						"Release");
-	l_dbus_message_set_arguments(msg, "");
-	l_dbus_message_set_no_reply(msg, true);
-	l_dbus_send(dbus_get_bus(), msg);
-}
-
-static void dpp_destroy_agent(struct dpp_sm *dpp)
-{
-	if (!dpp->agent)
-		return;
-
-	if (dpp->agent->pending_id) {
-		dpp_agent_cancel(dpp);
-		l_dbus_cancel(dbus_get_bus(), dpp->agent->pending_id);
-	}
-
-	dpp_agent_release(dpp);
-
-	l_debug("Released SharedCodeAgent on path %s", dpp->agent->path);
-
-	pkex_agent_free(dpp->agent);
-	dpp->agent = NULL;
-}
-
 static void dpp_free_auth_data(struct dpp_sm *dpp)
 {
 	if (dpp->own_proto_public) {
@@ -480,6 +428,47 @@ static void dpp_free_auth_data(struct dpp_sm *dpp)
 
 }
 
+static void dpp_agent_cancel(struct dpp_sm *dpp)
+{
+	struct l_dbus_message *msg;
+	const char *reason = "shutdown";
+
+	if (L_WARN_ON(!dpp_agent_name))
+		return;
+
+	msg = l_dbus_message_new_method_call(dbus_get_bus(),
+						dpp_agent_name,
+						dpp_agent_path,
+						IWD_DPP_AGENT_INTERFACE,
+						"CancelSharedCode");
+	l_dbus_message_set_arguments(msg, "s", reason);
+	l_dbus_message_set_no_reply(msg, true);
+	l_dbus_send(dbus_get_bus(), msg);
+
+	l_dbus_cancel(dbus_get_bus(), dpp->agent_request_id);
+	dpp->agent_request_id = 0;
+}
+
+static void dpp_agent_release(void)
+{
+	struct l_dbus_message *msg;
+
+	if (L_WARN_ON(!dpp_agent_name))
+		return;
+
+	msg = l_dbus_message_new_method_call(dbus_get_bus(),
+						dpp_agent_name,
+						dpp_agent_path,
+						IWD_DPP_AGENT_INTERFACE,
+						"Release");
+	l_dbus_message_set_arguments(msg, "");
+	l_dbus_message_set_no_reply(msg, true);
+	l_dbus_send(dbus_get_bus(), msg);
+
+	l_dbus_remove_watch(dbus_get_bus(), dpp_agent_watch);
+}
+
+
 static void dpp_reset(struct dpp_sm *dpp)
 {
 	struct station *station = station_find(netdev_get_ifindex(dpp->netdev));
@@ -555,7 +544,8 @@ static void dpp_reset(struct dpp_sm *dpp)
 	explicit_bzero(dpp->z, dpp->key_len);
 	explicit_bzero(dpp->u, dpp->u_len);
 
-	dpp_destroy_agent(dpp);
+	if (dpp->agent_request_id)
+		dpp_agent_cancel(dpp);
 
 	dpp_free_pending_pkex_data(dpp);
 
@@ -599,6 +589,63 @@ static void dpp_free(struct dpp_sm *dpp)
 	l_free(dpp);
 }
 
+static void dpp_agent_disconnect_cb(struct l_dbus *dbus, void *user_data)
+{
+	const struct l_queue_entry *e;
+
+	l_debug("DPP agent disconnected");
+
+	for (e = l_queue_get_entries(dpp_list); e; e = e->next) {
+		struct dpp_sm *dpp = e->data;
+
+		/*
+		 * If this DPP SM was in the process of making an agent request
+		 * this protocol run won't complete, reset
+		 */
+		if (dpp->agent_request_id)
+			dpp_reset(dpp);
+	}
+
+	l_dbus_remove_watch(dbus, dpp_agent_watch);
+}
+
+static void dpp_agent_watch_destroy(void *user_data)
+{
+	dpp_agent_watch = 0;
+
+	l_free(dpp_agent_name);
+	dpp_agent_name = NULL;
+	l_free(dpp_agent_path);
+	dpp_agent_path = NULL;
+}
+
+int dpp_register_agent(const char *name, const char *path)
+{
+	if (dpp_agent_path)
+		return -EEXIST;
+
+	dpp_agent_name = l_strdup(name);
+	dpp_agent_path = l_strdup(path);
+	dpp_agent_watch = l_dbus_add_disconnect_watch(dbus_get_bus(),
+						name,
+						dpp_agent_disconnect_cb,
+						NULL, dpp_agent_watch_destroy);
+	return 0;
+}
+
+int dpp_unregister_agent(const char *name, const char *path)
+{
+	if (!dpp_agent_path || strcmp(dpp_agent_path, path))
+		return -ENOENT;
+
+	if (strcmp(dpp_agent_name, name))
+		return -EPERM;
+
+	l_dbus_remove_watch(dbus_get_bus(), dpp_agent_watch);
+
+	return 0;
+}
+
 static void dpp_send_frame_cb(struct l_genl_msg *msg, void *user_data)
 {
 	struct dpp_sm *dpp = user_data;
@@ -4832,6 +4879,9 @@ static void dpp_exit(void)
 	nl80211 = NULL;
 
 	l_queue_destroy(dpp_list, (l_queue_destroy_func_t) dpp_free);
+
+	if (dpp_agent_name)
+		dpp_agent_release();
 }
 
 IWD_MODULE(dpp, dpp_init, dpp_exit);
diff --git a/src/dpp.h b/src/dpp.h
new file mode 100644
index 00000000..d66deb52
--- /dev/null
+++ b/src/dpp.h
@@ -0,0 +1,24 @@
+/*
+ *
+ *  Wireless daemon for Linux
+ *
+ *  Copyright (C) 2024  Locus Robotics. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+int dpp_register_agent(const char *name, const char *path);
+int dpp_unregister_agent(const char *name, const char *path);
-- 
2.34.1