logind: add virtual object paths that always can be used to refer to the callers session, user, seat or machine object

This way clients can skip invoking GetSessionByPID() for their own PID
or a similar call to access these objects.

3 files changed, 95 insertions, 35 deletions

diff --git a/src/login/logind-seat-dbus.c b/src/login/logind-seat-dbus.c
index e9f8d2637e..c59dfd9338 100644
--- a/src/login/logind-seat-dbus.c
+++ b/src/login/logind-seat-dbus.c
@@ -254,10 +254,9 @@ const sd_bus_vtable seat_vtable[] = {
 };
 
 int seat_object_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
-        _cleanup_free_ char *e = NULL;
         Manager *m = userdata;
         Seat *seat;
-        const char *p;
+        int r;
 
         assert(bus);
         assert(path);
@@ -265,17 +264,43 @@ int seat_object_find(sd_bus *bus, const char *path, const char *interface, void
         assert(found);
         assert(m);
 
-        p = startswith(path, "/org/freedesktop/login1/seat/");
-        if (!p)
-                return 0;
+        if (streq(path, "/org/freedesktop/login1/seat/self")) {
+                sd_bus_message *message;
+                Session *session;
+                pid_t pid;
 
-        e = bus_path_unescape(p);
-        if (!e)
-                return -ENOMEM;
+                message = sd_bus_get_current(bus);
+                if (!message)
+                        return 0;
 
-        seat = hashmap_get(m->seats, e);
-        if (!seat)
-                return 0;
+                r = sd_bus_get_owner_pid(bus, sd_bus_message_get_sender(message), &pid);
+                if (r < 0)
+                        return 0;
+
+                r = manager_get_session_by_pid(m, pid, &session);
+                if (r <= 0)
+                        return 0;
+
+                if (!session->seat)
+                        return 0;
+
+                seat = session->seat;
+        } else {
+                _cleanup_free_ char *e = NULL;
+                const char *p;
+
+                p = startswith(path, "/org/freedesktop/login1/seat/");
+                if (!p)
+                        return 0;
+
+                e = bus_path_unescape(p);
+                if (!e)
+                        return -ENOMEM;
+
+                seat = hashmap_get(m->seats, e);
+                if (!seat)
+                        return 0;
+        }
 
         *found = seat;
         return 1;
diff --git a/src/login/logind-session-dbus.c b/src/login/logind-session-dbus.c
index cda6a0a482..a559e6045b 100644
--- a/src/login/logind-session-dbus.c
+++ b/src/login/logind-session-dbus.c
@@ -465,10 +465,9 @@ const sd_bus_vtable session_vtable[] = {
 };
 
 int session_object_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
-        _cleanup_free_ char *e = NULL;
         Manager *m = userdata;
         Session *session;
-        const char *p;
+        int r;
 
         assert(bus);
         assert(path);
@@ -476,17 +475,37 @@ int session_object_find(sd_bus *bus, const char *path, const char *interface, vo
         assert(found);
         assert(m);
 
-        p = startswith(path, "/org/freedesktop/login1/session/");
-        if (!p)
-                return 0;
+        if (streq(path, "/org/freedesktop/login1/session/self")) {
+                sd_bus_message *message;
+                pid_t pid;
 
-        e = bus_path_unescape(p);
-        if (!e)
-                return -ENOMEM;
+                message = sd_bus_get_current(bus);
+                if (!message)
+                        return 0;
 
-        session = hashmap_get(m->sessions, e);
-        if (!session)
-                return 0;
+                r = sd_bus_get_owner_pid(bus, sd_bus_message_get_sender(message), &pid);
+                if (r < 0)
+                        return 0;
+
+                r = manager_get_session_by_pid(m, pid, &session);
+                if (r <= 0)
+                        return 0;
+        } else {
+                _cleanup_free_ char *e = NULL;
+                const char *p;
+
+                p = startswith(path, "/org/freedesktop/login1/session/");
+                if (!p)
+                        return 0;
+
+                e = bus_path_unescape(p);
+                if (!e)
+                        return -ENOMEM;
+
+                session = hashmap_get(m->sessions, e);
+                if (!session)
+                        return 0;
+        }
 
         *found = session;
         return 1;
diff --git a/src/login/logind-user-dbus.c b/src/login/logind-user-dbus.c
index dbd617f7ac..563c7ef6be 100644
--- a/src/login/logind-user-dbus.c
+++ b/src/login/logind-user-dbus.c
@@ -236,11 +236,7 @@ const sd_bus_vtable user_vtable[] = {
 };
 
 int user_object_find(sd_bus *bus, const char *path, const char *interface, void **found, void *userdata) {
-
-        _cleanup_free_ char *e = NULL;
         Manager *m = userdata;
-        unsigned long lu;
-        const char *p;
         User *user;
         int r;
 
@@ -250,17 +246,37 @@ int user_object_find(sd_bus *bus, const char *path, const char *interface, void
         assert(found);
         assert(m);
 
-        p = startswith(path, "/org/freedesktop/login1/user/_");
-        if (!p)
-                return 0;
+        if (streq(path, "/org/freedesktop/login1/user/self")) {
+                sd_bus_message *message;
+                pid_t pid;
 
-        r = safe_atolu(p, &lu);
-        if (r < 0)
-                return 0;
+                message = sd_bus_get_current(bus);
+                if (!message)
+                        return 0;
 
-        user = hashmap_get(m->users, ULONG_TO_PTR(lu));
-        if (!user)
-                return 0;
+                r = sd_bus_get_owner_pid(bus, sd_bus_message_get_sender(message), &pid);
+                if (r < 0)
+                        return 0;
+
+                r = manager_get_user_by_pid(m, pid, &user);
+                if (r <= 0)
+                        return 0;
+        } else {
+                unsigned long lu;
+                const char *p;
+
+                p = startswith(path, "/org/freedesktop/login1/user/_");
+                if (!p)
+                        return 0;
+
+                r = safe_atolu(p, &lu);
+                if (r < 0)
+                        return 0;
+
+                user = hashmap_get(m->users, ULONG_TO_PTR(lu));
+                if (!user)
+                        return 0;
+        }
 
         *found = user;
         return 1;