core: add support for naming file descriptors passed using socket activation

This adds support for naming file descriptors passed using socket
activation. The names are passed in a new $LISTEN_FDNAMES= environment
variable, that matches the existign $LISTEN_FDS= one and contains a
colon-separated list of names.

This also adds support for naming fds submitted to the per-service fd
store using FDNAME= in the sd_notify() message.

This also adds a new FileDescriptorName= setting for socket unit files
to set the name for fds created by socket units.

This also adds a new call sd_listen_fds_with_names(), that is similar to
sd_listen_fds(), but also returns the names of the fds.

systemd-activate gained the new --fdname= switch to specify a name for
testing socket activation.

This is based on #1247 by Maciej Wereski.

Fixes #1247.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/core/socket.h b/src/core/socket.h
index 96091b0609..94cda8a90d 100644
--- a/src/core/socket.h
+++ b/src/core/socket.h
@@ -154,6 +154,8 @@ struct Socket {
         char *user, *group;
 
         bool reset_cpu_usage:1;
+
+        char *fdname;
 };
 
 /* Called from the service code when collecting fds */
@@ -164,6 +166,10 @@ void socket_connection_unref(Socket *s);
 
 void socket_free_ports(Socket *s);
 
+int socket_instantiate_service(Socket *s);
+
+char *socket_fdname(Socket *s);
+
 extern const UnitVTable socket_vtable;
 
 const char* socket_exec_command_to_string(SocketExecCommand i) _const_;
@@ -173,5 +179,3 @@ const char* socket_result_to_string(SocketResult i) _const_;
 SocketResult socket_result_from_string(const char *s) _pure_;
 
 const char* socket_port_type_to_string(SocketPort *p) _pure_;
-
-int socket_instantiate_service(Socket *s);