r5108: the beginnings of a nbtd server for Samba4. Currently just displays

the packets it receives, but it at least shows how the server
structure will work.

To implement it I extended the libcli/nbt/ library to allow for an
incoming packet handler to be registered. That allows the nbt client
library to be used for low level processing of the nbtd server packets.

Other changes:

 - made the socket library always set SO_REUSEADDR when binding to an
   interface, to ensure that restarts of a server don't have to wait
   for a couple of minutes.

 - made the nbt port configurable. Defaults to 137, but other ports
   will be useful for testing.
(This used to be commit 2fedca6adfd4df9e85cc86896dfa79630777a917)

4 files changed, 230 insertions, 0 deletions

diff --git a/source4/nbt_server/config.mk b/source4/nbt_server/config.mk
new file mode 100644
index 0000000000..093cb61864
--- /dev/null
+++ b/source4/nbt_server/config.mk
@@ -0,0 +1,13 @@
+# NBTD server subsystem
+
+#######################
+# Start SUBSYSTEM NBTD
+[SUBSYSTEM::NBTD]
+INIT_OBJ_FILES = \
+		nbt_server/nbt_server.o
+ADD_OBJ_FILES = \
+		nbt_server/interfaces.o
+REQUIRED_SUBSYSTEMS = \
+		LIBCLI_NBT
+# End SUBSYSTEM SMB
+#######################
diff --git a/source4/nbt_server/interfaces.c b/source4/nbt_server/interfaces.c
new file mode 100644
index 0000000000..18893e179b
--- /dev/null
+++ b/source4/nbt_server/interfaces.c
@@ -0,0 +1,88 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   NBT interface handling
+
+   Copyright (C) Andrew Tridgell	2005
+   
+   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; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+#include "dlinklist.h"
+#include "nbt_server/nbt_server.h"
+#include "smbd/service_task.h"
+#include "libcli/nbt/libnbt.h"
+
+/*
+  start listening on the given address
+*/
+static NTSTATUS nbt_add_socket(struct nbt_server *nbtsrv, 
+			       const char *address, const char *bcast)
+{
+	struct nbt_interface *iface;
+	NTSTATUS status;
+
+	iface = talloc(nbtsrv, struct nbt_interface);
+	NT_STATUS_HAVE_NO_MEMORY(iface);
+
+	iface->nbtsrv = nbtsrv;
+	iface->bcast_address = talloc_steal(iface, bcast);
+	iface->ip_address = talloc_steal(iface, address);
+
+	iface->nbtsock = nbt_name_socket_init(iface, nbtsrv->task->event_ctx);
+	NT_STATUS_HAVE_NO_MEMORY(iface->ip_address);
+
+	status = socket_listen(iface->nbtsock->sock, address, lp_nbt_port(), 0, 0);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0,("Failed to bind to %s:%d - %s\n", 
+			 address, lp_nbt_port(), nt_errstr(status)));
+		talloc_free(iface);
+		return status;
+	}
+
+	DLIST_ADD(nbtsrv->interfaces, iface);
+
+	return NT_STATUS_OK;
+}
+
+
+/*
+  setup our listening sockets on the configured network interfaces
+*/
+NTSTATUS nbt_startup_interfaces(struct nbt_server *nbtsrv)
+{
+	int num_interfaces = iface_count();
+	int i;
+	TALLOC_CTX *tmp_ctx = talloc_new(nbtsrv);
+	NTSTATUS status;
+
+	status = nbt_add_socket(nbtsrv, 
+				talloc_strdup(tmp_ctx, "0.0.0.0"), 
+				talloc_strdup(tmp_ctx, "255.255.255.255"));
+	NT_STATUS_NOT_OK_RETURN(status);
+
+	for (i=0; i<num_interfaces; i++) {
+		const char *address = talloc_strdup(tmp_ctx, sys_inet_ntoa(*iface_n_ip(i)));
+		const char *bcast   = talloc_strdup(tmp_ctx, sys_inet_ntoa(*iface_n_bcast(i)));
+
+		status = nbt_add_socket(nbtsrv, address, bcast);
+		NT_STATUS_NOT_OK_RETURN(status);
+	}
+
+	talloc_free(tmp_ctx);
+
+	return NT_STATUS_OK;
+}
diff --git a/source4/nbt_server/nbt_server.c b/source4/nbt_server/nbt_server.c
new file mode 100644
index 0000000000..19dabdfa51
--- /dev/null
+++ b/source4/nbt_server/nbt_server.c
@@ -0,0 +1,85 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   NBT server task
+
+   Copyright (C) Andrew Tridgell	2005
+   
+   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; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+#include "events.h"
+#include "libcli/nbt/libnbt.h"
+#include "smbd/service_task.h"
+#include "nbt_server/nbt_server.h"
+
+
+/*
+  receive an incoming request
+*/
+static void nbt_request_handler(struct nbt_name_socket *nbtsock, 
+				struct nbt_name_packet *packet, 
+				const char *src_address, int src_port)
+{
+	struct nbt_interface *iface = talloc_get_type(nbtsock->incoming.private, 
+						      struct nbt_interface);
+	DEBUG(0,("nbtd request from %s:%d\n", src_address, src_port));
+
+	NDR_PRINT_DEBUG(nbt_name_packet, packet);
+}
+
+
+/*
+  startup the nbtd task
+*/
+static void nbtd_task_init(struct task_server *task)
+{
+	struct nbt_server *nbtsrv;
+	struct nbt_interface *iface;
+
+	nbtsrv = talloc(task, struct nbt_server);
+	if (nbtsrv == NULL) {
+		task_terminate(task, "nbtd: out of memory");
+		return;
+	}
+
+	nbtsrv->task = task;
+	nbtsrv->interfaces = NULL;
+
+	nbt_startup_interfaces(nbtsrv);
+
+	for (iface=nbtsrv->interfaces;iface;iface=iface->next) {
+		nbt_set_incoming_handler(iface->nbtsock, nbt_request_handler, iface);
+	}
+}
+
+
+/*
+  initialise the nbt server
+ */
+static NTSTATUS nbtd_init(struct event_context *event_ctx, const struct model_ops *model_ops)
+{
+	return task_server_startup(event_ctx, model_ops, nbtd_task_init);
+}
+
+
+/*
+  register ourselves as a available server
+*/
+NTSTATUS server_service_nbtd_init(void)
+{
+	return register_server_service("nbt", nbtd_init);
+}
diff --git a/source4/nbt_server/nbt_server.h b/source4/nbt_server/nbt_server.h
new file mode 100644
index 0000000000..9ef510fbb2
--- /dev/null
+++ b/source4/nbt_server/nbt_server.h
@@ -0,0 +1,44 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   NBT server structures
+
+   Copyright (C) Andrew Tridgell	2005
+   
+   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; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+
+/* a list of network interfaces we are listening on */
+struct nbt_interface {
+	struct nbt_interface *next, *prev;
+	const char *ip_address;
+	const char *bcast_address;
+	struct nbt_name_socket *nbtsock;
+	struct nbt_server *nbtsrv;
+};
+
+
+/*
+  top level context structure for the nbt server
+*/
+struct nbt_server {
+	struct task_server *task;
+
+	struct nbt_interface *interfaces;
+};
+
+
+