This is the start of a bit of a rewrite of winbindd's connection handling.

I've wrapped up all the decisions about managing, making and closing
connections into a connection manager in nsswitch/winbindd_cm.c.

It's rather incomplete at the moment - only querying basic user info works
at the moment (i.e finger -m DOMAIN/user) and everything else is broken.

Jeremy, please take a look and I'll start moving across the rest of
winbindd to this new system.
(This used to be commit c369cf5af787ed9c642778d21f162716fbf0620e)

1 files changed, 245 insertions, 0 deletions

diff --git a/source3/nsswitch/winbindd_cm.c b/source3/nsswitch/winbindd_cm.c
new file mode 100644
index 0000000000..ec1db826dd
--- /dev/null
+++ b/source3/nsswitch/winbindd_cm.c
@@ -0,0 +1,245 @@
+/* 
+   Unix SMB/Netbios implementation.
+   Version 3.0
+
+   Winbind daemon connection manager
+
+   Copyright (C) Tim Potter 2001
+   
+   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.
+*/
+
+/*
+   We need to manage connections to domain controllers without having to
+   mess up the main winbindd code with other issues.  The aim of the
+   connection manager is to:
+  
+       - make connections to domain controllers and cache them
+       - re-establish connections when networks or servers go down
+       - centralise the policy on connection timeouts, domain controller
+         selection etc
+       - manage re-entrancy for when winbindd becomes able to handle
+         multiple outstanding rpc requests
+  
+   We can also throw away the CLI_POLICY_HND stuff as all this information
+   will be stored within this module.
+  
+   Why not have connection management as part of the rpc layer like tng?
+   Good question.  This code may morph into libsmb/rpc_cache.c or something
+   like that but at the moment it's simply staying as part of winbind.  I
+   think the TNG architecture of forcing every user of the rpc layer to use
+   the connection caching system is a bad idea.  It should be an optional
+   method of using the routines.
+
+   The TNG design is quite good but I disagree with some aspects of the
+   implementation. -tpot
+
+ */
+
+/*
+   TODO:
+
+     - I'm pretty annoyed by all the make_nmb_name() stuff.  It should be
+       moved down into another function.
+
+     - There needs to be a utility function in libsmb/namequery.c that does
+       get_any_dc_name() 
+
+ */
+
+#include "winbindd.h"
+
+/* We store lists of connections here */
+
+struct winbindd_cm_conn {
+        struct winbindd_cm_conn *prev, *next;
+        fstring domain;
+        fstring controller;
+        fstring pipe_name;
+        struct cli_state cli;
+        POLICY_HND pol;
+};
+
+/* Global list of connections.  Initially a DLIST but can become a hash
+   table or whatever later. */
+
+struct winbindd_cm_conn *cm_conns = NULL;
+
+/* Get a domain controller name */
+
+BOOL cm_get_dc_name(char *domain, fstring srv_name)
+{
+	struct in_addr *ip_list, dc_ip;
+	extern pstring global_myname;
+	int count, i;
+
+	/* Lookup domain controller name */
+		
+	if (!get_dc_list(False, domain, &ip_list, &count))
+		return False;
+		
+	/* Firstly choose a PDC/BDC who has the same network address as any
+	   of our interfaces. */
+	
+	for (i = 0; i < count; i++) {
+		if(!is_local_net(ip_list[i]))
+			goto got_ip;
+	}
+	
+	i = (sys_random() % count);
+	
+ got_ip:
+	dc_ip = ip_list[i];
+	SAFE_FREE(ip_list);
+		
+	if (!lookup_pdc_name(global_myname, domain, &dc_ip, srv_name))
+		return False;
+
+	return True;
+}
+
+/* Open a new smb pipe connection to a DC on a given domain */
+
+static BOOL cm_open_connection(char *domain, char *pipe_name,
+                               struct winbindd_cm_conn *new_conn)
+{
+	struct nmb_name calling, called;
+        extern pstring global_myname;
+        fstring dest_host;
+        struct in_addr dest_ip;
+        BOOL result = False;
+        struct ntuser_creds creds;
+
+        ZERO_STRUCT(new_conn->cli);
+
+        fstrcpy(new_conn->domain, domain);
+        fstrcpy(new_conn->pipe_name, pipe_name);
+        
+        /* Look for a domain controller for this domain */
+
+        if (!cm_get_dc_name(lp_workgroup(), new_conn->controller))
+                goto done;
+
+        /* Initialise SMB connection */
+
+        if (!cli_initialise(&new_conn->cli))
+                goto done;
+
+	if (!resolve_srv_name(new_conn->controller, dest_host, &dest_ip))
+		goto done;
+
+	make_nmb_name(&called, dns_to_netbios_name(new_conn->controller), 
+                      0x20);
+	make_nmb_name(&calling, dns_to_netbios_name(global_myname), 0);
+
+	ZERO_STRUCT(creds);
+	creds.pwd.null_pwd = 1;
+
+	cli_init_creds(&new_conn->cli, &creds);
+
+	if (!cli_establish_connection(&new_conn->cli, new_conn->controller, 
+                                      &dest_ip, &calling, &called, "IPC$", 
+                                      "IPC", False, True))
+		goto done;
+
+	if (!cli_nt_session_open (&new_conn->cli, pipe_name))
+		goto done;
+
+        result = True;
+
+ done:
+        if (!result)
+                cli_shutdown(&new_conn->cli);
+
+        return result;
+}
+
+/* Return a LSA policy handle on a domain */
+
+CLI_POLICY_HND *cm_get_lsa_handle(char *domain)
+{
+        struct winbindd_cm_conn *conn;
+        uint32 des_access = SEC_RIGHTS_MAXIMUM_ALLOWED;
+        NTSTATUS result;
+        static CLI_POLICY_HND hnd;
+
+        /* Look for existing connections */
+
+        for (conn = cm_conns; conn; conn = conn->next) {
+                if (strequal(conn->domain, domain) &&
+                    strequal(conn->pipe_name, PIPE_LSARPC))
+                        goto ok;
+        }
+
+        /* Create a new one */
+
+        if (!(conn = (struct winbindd_cm_conn *)
+              malloc(sizeof(struct winbindd_cm_conn))))
+                return NULL;
+
+        if (!cm_open_connection(domain, PIPE_LSARPC, conn)) {
+                DEBUG(3, ("Could not connect to a dc for domain %s\n",
+                          domain));
+                return NULL;
+        }
+
+        result = cli_lsa_open_policy(&conn->cli, conn->cli.mem_ctx, False, 
+                                     des_access, &conn->pol);
+
+        if (!NT_STATUS_IS_OK(result))
+                return NULL;
+
+        /* Add to list */
+
+        DLIST_ADD(cm_conns, conn);
+
+ ok:
+        hnd.pol = conn->pol;
+        hnd.cli = &conn->cli;
+
+        return &hnd;
+}
+
+/* Return a SAM policy handle on a domain */
+
+CLI_POLICY_HND *cm_get_sam_handle(char *domain)
+{ 
+        DEBUG(0, ("get_sam_handle(): not implemented\n"));
+        return NULL;
+}
+
+/* Return a SAM domain policy handle on a domain */
+
+CLI_POLICY_HND *cm_get_sam_dom_handle(char *domain)
+{
+        DEBUG(0, ("get_sam_dom_handle(): not implemented\n"));
+        return NULL;
+}
+
+/* Return a SAM policy handle on a domain user */
+
+CLI_POLICY_HND *cm_get_sam_user_handle(char *domain, char *user)
+{
+        DEBUG(0, ("get_sam_user_handle(): not implemented\n"));
+        return NULL;
+}
+
+/* Return a SAM policy handle on a domain group */
+
+CLI_POLICY_HND *cm_get_sam_group_handle(char *domain, char *group)
+{
+        DEBUG(0, ("get_sam_group_handle(): not implemented\n"));
+        return NULL;
+}