pim6d: add skeleton for IPv6 PIM daemon

This newborn pim6d is essentially an empty husk, but it does build
without warnings or errors and has the build system integration prepared
and working.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

4 files changed, 248 insertions, 7 deletions

diff --git a/pimd/.gitignore b/pimd/.gitignore
index b1780df75..3f7347108 100644
--- a/pimd/.gitignore
+++ b/pimd/.gitignore
@@ -1,3 +1,4 @@
-pimd
-mtracebis
-test_igmpv3_join
+/pimd
+/pim6d
+/mtracebis
+/test_igmpv3_join
diff --git a/pimd/pim6_main.c b/pimd/pim6_main.c
new file mode 100644
index 000000000..02654e1cb
--- /dev/null
+++ b/pimd/pim6_main.c
@@ -0,0 +1,214 @@
+/*
+ * PIMv6 main()
+ * Copyright (C) 2021  David Lamparter for NetDEF, Inc.
+ * Copyright (C) 2008  Everton da Silva Marques (pim_main.c)
+ *
+ * This program 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; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * 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; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+
+#include "lib/vrf.h"
+#include "lib/filter.h"
+#include "lib/plist.h"
+#include "lib/routemap.h"
+#include "lib/routing_nb.h"
+
+#include "lib/privs.h"
+#include "lib/sigevent.h"
+#include "lib/libfrr.h"
+#include "lib/version.h"
+
+#include "pimd.h"
+#include "pim_instance.h"
+#include "pim_errors.h"
+#include "pim_iface.h"
+#include "pim_zebra.h"
+
+zebra_capabilities_t _caps_p[] = {
+	ZCAP_SYS_ADMIN,
+	ZCAP_NET_ADMIN,
+	ZCAP_NET_RAW,
+	ZCAP_BIND,
+};
+
+/* pimd privileges to run with */
+struct zebra_privs_t pimd_privs = {
+#if defined(FRR_USER) && defined(FRR_GROUP)
+	.user = FRR_USER,
+	.group = FRR_GROUP,
+#endif
+#ifdef VTY_GROUP
+	.vty_group = VTY_GROUP,
+#endif
+	.caps_p = _caps_p,
+	.cap_num_p = array_size(_caps_p),
+	.cap_num_i = 0,
+};
+
+static void pim6_terminate(void);
+
+static void pim6_sighup(void)
+{
+	zlog_info("SIGHUP received, ignoring");
+}
+
+static void pim6_sigint(void)
+{
+	zlog_notice("Terminating on signal SIGINT");
+	pim6_terminate();
+	exit(1);
+}
+
+static void pim6_sigterm(void)
+{
+	zlog_notice("Terminating on signal SIGTERM");
+	pim6_terminate();
+	exit(1);
+}
+
+static void pim6_sigusr1(void)
+{
+	zlog_rotate();
+}
+
+struct frr_signal_t pim6d_signals[] = {
+	{
+		.signal = SIGHUP,
+		.handler = &pim6_sighup,
+	},
+	{
+		.signal = SIGUSR1,
+		.handler = &pim6_sigusr1,
+	},
+	{
+		.signal = SIGINT,
+		.handler = &pim6_sigint,
+	},
+	{
+		.signal = SIGTERM,
+		.handler = &pim6_sigterm,
+	},
+};
+
+static const struct frr_yang_module_info *const pim6d_yang_modules[] = {
+	&frr_filter_info,
+	&frr_interface_info,
+	&frr_route_map_info,
+	&frr_vrf_info,
+	&frr_routing_info,
+};
+
+/* clang-format off */
+FRR_DAEMON_INFO(pim6d, PIM6,
+	.vty_port = 0,
+	.flags = FRR_NO_SPLIT_CONFIG,
+
+	.proghelp = "Protocol Independent Multicast (RFC7761) for IPv6",
+
+	.signals = pim6d_signals,
+	.n_signals = array_size(pim6d_signals),
+
+	.privs = &pimd_privs,
+
+	.yang_modules = pim6d_yang_modules,
+	.n_yang_modules = array_size(pim6d_yang_modules),
+);
+/* clang-format on */
+
+
+int main(int argc, char **argv, char **envp)
+{
+	static struct option longopts[] = {
+		{},
+	};
+
+	frr_preinit(&pim6d_di, argc, argv);
+	frr_opt_add("", longopts, "");
+
+	/* this while just reads the options */
+	while (1) {
+		int opt;
+
+		opt = frr_getopt(argc, argv, NULL);
+
+		if (opt == EOF)
+			break;
+
+		switch (opt) {
+		case 0:
+			break;
+		default:
+			frr_help_exit(1);
+		}
+	}
+
+	pim_router_init();
+	/* TODO PIM6: temporary enable all debugs, remove later in PIMv6 work */
+	router->debugs = ~0U;
+
+	access_list_init();
+	prefix_list_init();
+
+	/*
+	 * Initializations
+	 */
+	pim_error_init();
+	pim_vrf_init();
+#if 0
+	prefix_list_add_hook(pim_prefix_list_update);
+	prefix_list_delete_hook(pim_prefix_list_update);
+
+	pim_route_map_init();
+	pim_init();
+#endif
+
+	/*
+	 * Initialize zclient "update" and "lookup" sockets
+	 */
+	if_zapi_callbacks(pim_ifp_create, pim_ifp_up,
+			  pim_ifp_down, pim_ifp_destroy);
+
+	/* TODO PIM6: next line is temporary since pim_cmd_init is disabled */
+	if_cmd_init(NULL);
+
+#if 0
+	pim_zebra_init();
+	pim_bfd_init();
+	pim_mlag_init();
+
+	hook_register(routing_conf_event,
+		      routing_control_plane_protocols_name_validate);
+
+	routing_control_plane_protocols_register_vrf_dependency();
+#endif
+
+	frr_config_fork();
+	frr_run(router->master);
+
+	/* never reached */
+	return 0;
+}
+
+static void pim6_terminate(void)
+{
+	pim_vrf_terminate();
+	pim_router_terminate();
+
+	prefix_list_reset();
+	access_list_reset();
+
+	frr_fini();
+}
diff --git a/pimd/pimd.c b/pimd/pimd.c
index 38e727394..992bb931b 100644
--- a/pimd/pimd.c
+++ b/pimd/pimd.c
@@ -115,7 +115,6 @@ void pim_router_init(void)
 
 void pim_router_terminate(void)
 {
-	pim_mlag_terminate();
 	XFREE(MTYPE_ROUTER, router);
 }
 
@@ -155,6 +154,7 @@ void pim_terminate(void)
 	}
 
 	pim_free();
+	pim_mlag_terminate();
 	pim_router_terminate();
 
 	frr_fini();
diff --git a/pimd/subdir.am b/pimd/subdir.am
index f8bc0ff08..520b1aa18 100644
--- a/pimd/subdir.am
+++ b/pimd/subdir.am
@@ -12,7 +12,7 @@ man8 += $(MANBUILD)/frr-pimd.8
 man8 += $(MANBUILD)/mtracebis.8
 endif
 
-pimd_pimd_SOURCES = \
+pim_common = \
 	pimd/pim_assert.c \
 	pimd/pim_bfd.c \
 	pimd/pim_br.c \
@@ -32,7 +32,6 @@ pimd_pimd_SOURCES = \
 	pimd/pim_join.c \
 	pimd/pim_jp_agg.c \
 	pimd/pim_macro.c \
-	pimd/pim_main.c \
 	pimd/pim_memory.c \
 	pimd/pim_mlag.c \
 	pimd/pim_mroute.c \
@@ -50,7 +49,6 @@ pimd_pimd_SOURCES = \
 	pimd/pim_routemap.c \
 	pimd/pim_rp.c \
 	pimd/pim_rpf.c \
-	pimd/pim_signals.c \
 	pimd/pim_sock.c \
 	pimd/pim_ssm.c \
 	pimd/pim_ssmpingd.c \
@@ -68,12 +66,26 @@ pimd_pimd_SOURCES = \
 	pimd/pimd.c \
 	# end
 
+pimd_pimd_SOURCES = \
+	$(pim_common) \
+	pimd/pim_main.c \
+	pimd/pim_signals.c \
+	# end
+
 nodist_pimd_pimd_SOURCES = \
 	yang/frr-pim.yang.c \
 	yang/frr-pim-rp.yang.c \
 	yang/frr-igmp.yang.c \
 	# end
 
+pimd_pim6d_SOURCES = \
+	$(pim_common) \
+	pimd/pim6_main.c \
+	# end
+
+nodist_pimd_pim6d_SOURCES = \
+	# end
+
 noinst_HEADERS += \
 	pimd/pim_assert.h \
 	pimd/pim_bfd.h \
@@ -134,12 +146,26 @@ clippy_scan += \
 	pimd/pim_cmd.c \
 	# end
 
+pimd_pimd_CFLAGS = $(AM_CFLAGS) -DPIM_IPV=4
 pimd_pimd_LDADD = lib/libfrr.la $(LIBCAP)
 
+if PIMD
+if DEV_BUILD
+#
+# pim6d is only enabled for --enable-dev-build, and NOT installed currently
+# (change noinst_ to sbin_ below to install it.)
+#
+noinst_PROGRAMS += pimd/pim6d
+pimd_pim6d_CFLAGS = $(AM_CFLAGS) -DPIM_IPV=6
+pimd_pim6d_LDADD = lib/libfrr.la $(LIBCAP)
+endif
+endif
+
 pimd_test_igmpv3_join_LDADD = lib/libfrr.la
 pimd_test_igmpv3_join_SOURCES = pimd/test_igmpv3_join.c
 
 pimd_mtracebis_LDADD =  lib/libfrr.la
+pimd_mtracebis_CFLAGS = $(AM_CFLAGS) -DPIM_IPV=4
 pimd_mtracebis_SOURCES = pimd/mtracebis.c \
 			 pimd/mtracebis_netlink.c \
 			 pimd/mtracebis_routeget.c \