tlshd: Add init/shutdown hooks for the session tagging subsystem

TLS session tags will be managed in functions contained in a new
source file, tags.c.

Signed-off-by: Chuck Lever <[email protected]>

Author: chucklever

src/tlshd/Makefile.am

@@ -20,8 +20,9 @@ sbin_PROGRAMS		= tlshd
 tlshd_CFLAGS		= -Werror -Wall -Wextra $(LIBGNUTLS_CFLAGS) \
 			  $(LIBKEYUTILS_CFLAGS) $(GLIB_CFLAGS) $(LIBNL3_CFLAGS) \
 			  $(LIBNL_GENL3_CFLAGS) $(LIBYAML_CFLAGS)
-tlshd_SOURCES		= client.c config.c handshake.c keyring.c ktls.c log.c \
-			  main.c netlink.c netlink.h server.c tlshd.h quic.c
+tlshd_SOURCES		= client.c config.c handshake.c keyring.c ktls.c \
+			  log.c main.c netlink.c netlink.h quic.c server.c \
+			  tags.c tlshd.h
 tlshd_LDADD		= $(LIBGNUTLS_LIBS) $(LIBKEYUTILS_LIBS) $(GLIB_LIBS) \
 			  $(LIBNL3_LIBS) $(LIBNL_GENL3_LIBS) $(LIBYAML_LIBS)
 

src/tlshd/config.c

@@ -108,11 +108,13 @@ bool tlshd_config_init(const gchar *pathname, bool legacy)
 	tlshd_keyring_link_session(".nfs");
 	tlshd_keyring_link_session(".nfsd");
 
-	return true;
+	/* Eventually the tags directory might become a tlshd config option */
+	return tlshd_tags_config_init("/etc/tlshd/tags.d");
 }
 
 void tlshd_config_shutdown(void)
 {
+	tlshd_tags_config_shutdown();
 	g_key_file_free(tlshd_configuration);
 }
 

src/tlshd/tags.c

@@ -0,0 +1,51 @@
+/*
+ * TLS session tagging
+ *
+ * Copyright (c) 2025 Oracle and/or its affiliates.
+ *
+ * ktls-utils is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include "config.h"
+
+#include <stdbool.h>
+#include <keyutils.h>
+
+#include <gnutls/gnutls.h>
+#include <gnutls/abstract.h>
+
+#include <glib.h>
+
+#include "tlshd.h"
+
+/* --- Subsystem start-up / shutdown APIs --- */
+
+/**
+ * tlshd_tags_config_init - Initialize the TLS session tags configuration
+ * @tagsdir: pathname of directory containing files that define tags
+ *
+ */
+bool tlshd_tags_config_init(__attribute__ ((unused)) const char *tagsdir)
+{
+	return true;
+}
+
+/**
+ * tlshd_tags_config_shutdown - Release all tag-related resources
+ *
+ */
+void tlshd_tags_config_shutdown(void)
+{
+}

src/tlshd/tlshd.h

@@ -119,6 +119,10 @@ extern void tlshd_genl_done(struct tlshd_handshake_parms *parms);
 extern void tlshd_tls13_serverhello_handshake(struct tlshd_handshake_parms *parms);
 extern void tlshd_quic_serverhello_handshake(struct tlshd_handshake_parms *parms);
 
+/* tags.c */
+extern bool tlshd_tags_config_init(const char *tagsdir);
+extern void tlshd_tags_config_shutdown(void);
+
 #ifdef HAVE_GNUTLS_QUIC
 #include <linux/quic.h>