From 6f0fb6644fbb9fe2c05f1719e619ce4d0073728d Mon Sep 17 00:00:00 2001
From: sinanmohd <sinan@sinanmohd.com>
Date: Sun, 21 Apr 2024 15:30:07 +0530
Subject: npassd/session: free session when owner service disconnects from the
 bus

---
 include/npassd/session.h |  5 +++-
 src/npassd/service.c     |  4 ++-
 src/npassd/session.c     | 64 ++++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 63 insertions(+), 10 deletions(-)

diff --git a/include/npassd/session.h b/include/npassd/session.h
index 6763c6a..a3aa705 100644
--- a/include/npassd/session.h
+++ b/include/npassd/session.h
@@ -4,11 +4,13 @@
 #include "npassd/common.h"
 
 #define SESSION_IFACE "org.freedesktop.Secret.Session"
+#define MAX_OWNER_LEN 64
 
 /* reusable slots */
 struct session {
 	bool isactive;
 	sd_bus_slot *slot;
+	char owner[MAX_OWNER_LEN];
 	/* +32 for snprintf("/session/%d") */
 	char path[sizeof(DBUS_OBJECT_PATH) + 32];
 };
@@ -16,4 +18,5 @@ struct session {
 void session_init(struct session *s, size_t n);
 int session_slot_available(struct session *s, size_t n);
 int session_free(struct session *s);
-int session_new(sd_bus *bus, struct session *s, unsigned slot_no);
+int session_new(sd_bus *bus, struct session *session, unsigned session_no,
+		const char *owner);
diff --git a/src/npassd/service.c b/src/npassd/service.c
index 60e458b..c93073a 100644
--- a/src/npassd/service.c
+++ b/src/npassd/service.c
@@ -23,6 +23,7 @@ static int handle_open_session(sd_bus_message *msg, void *data,
 {
 	struct service *service = data;
 	int ret, session_slot_no;
+	const char *sender;
 	char *algo;
 
 	ret = sd_bus_message_read(msg, "s", &algo);
@@ -43,8 +44,9 @@ static int handle_open_session(sd_bus_message *msg, void *data,
 		return ret;
 	}
 
+	sender = sd_bus_message_get_sender(msg);
 	ret = session_new(service->bus, &service->session[session_slot_no],
-			  session_slot_no);
+			  session_slot_no, sender);
 	if (ret < 0)
 		return ret;
 
diff --git a/src/npassd/session.c b/src/npassd/session.c
index e674bb7..7190aec 100644
--- a/src/npassd/session.c
+++ b/src/npassd/session.c
@@ -11,6 +11,9 @@
 
 static int handle_close(__attribute__((unused)) sd_bus_message *msg, void *data,
 			__attribute__((unused)) sd_bus_error *ret_error);
+static int handle_nameownerchanged(sd_bus_message *msg, void *data,
+				   __attribute__((unused))
+				   sd_bus_error *ret_error);
 
 static const sd_bus_vtable session_vtable[] = {
 	SD_BUS_VTABLE_START(0),
@@ -19,6 +22,28 @@ static const sd_bus_vtable session_vtable[] = {
 	SD_BUS_VTABLE_END,
 };
 
+static int handle_nameownerchanged(sd_bus_message *msg, void *data,
+				   __attribute__((unused))
+				   sd_bus_error *ret_error)
+{
+	struct session *session = data;
+	const char *name;
+	int ret;
+
+	ret = sd_bus_message_read(msg, "ss", NULL, &name);
+	if (ret < 0) {
+		print_err("%s", strerror(-ret));
+		return ret;
+	}
+
+	ret = strcmp(session->owner, name);
+	if (ret)
+		return 0;
+
+	session_free(session);
+	return 0;
+}
+
 static int handle_close(__attribute__((unused)) sd_bus_message *msg, void *data,
 			__attribute__((unused)) sd_bus_error *ret_error)
 {
@@ -28,7 +53,7 @@ static int handle_close(__attribute__((unused)) sd_bus_message *msg, void *data,
 	if (ret < 0)
 		print_err("Failed to free session: %s", strerror(-ret));
 
-	return ret;
+	return sd_bus_reply_method_return(msg, "");
 }
 
 int session_slot_available(struct session *s, size_t n)
@@ -47,25 +72,48 @@ int session_slot_available(struct session *s, size_t n)
 	return -ENOMEM;
 }
 
-int session_new(sd_bus *bus, struct session *session, unsigned session_no)
+int session_new(sd_bus *bus, struct session *session, unsigned session_no,
+		const char *owner)
 {
 	int ret;
 
-	snprintf(session->path, sizeof(session->path),
-		 DBUS_OBJECT_PATH "/session/%d", session_no);
+	ret = snprintf(session->path, sizeof(session->path),
+		       DBUS_OBJECT_PATH "/session/%d", session_no);
+	if (ret < 0 || (size_t)ret > sizeof(session->path)) {
+		print_err("%s", "Failed to create session path");
+		return -ENOMEM;
+	}
+
+	ret = snprintf(session->owner, sizeof(session->owner), "%s", owner);
+	if (ret < 0 || (size_t)ret > sizeof(session->owner)) {
+		print_err("%s", "Failed to set session owner");
+		return -ENOMEM;
+	}
+
 	ret = sd_bus_add_object_vtable(bus, &session->slot, session->path,
 				       SESSION_IFACE, session_vtable, session);
-	if (ret < 0)
+	if (ret < 0) {
 		print_err("Failed to create session: %s", strerror(-ret));
-	else
-		session->isactive = true;
+		return ret;
+	}
+	session->isactive = true;
+
+	ret = sd_bus_match_signal(bus, NULL, "org.freedesktop.DBus",
+				  "/org/freedesktop/DBus",
+				  "org.freedesktop.DBus", "NameOwnerChanged",
+				  handle_nameownerchanged, session);
+	if (ret < 0) {
+		session_free(session);
+		print_err("%s", strerror(-ret));
+		return ret;
+	}
 
 	return ret;
 }
 
 int session_free(struct session *s)
 {
-	if (!s->isactive)
+	if (s->isactive == false)
 		return -EINVAL;
 
 	s->isactive = false;
-- 
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