/* Unix SMB/CIFS implementation. 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 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 cm_get_dc_name() - Take care when destroying cli_structs as they can be shared between various sam handles. */ #include "winbindd.h" /* Global list of connections. Initially a DLIST but can become a hash table or whatever later. */ struct winbindd_cm_conn { struct winbindd_cm_conn *prev, *next; fstring domain; fstring controller; fstring pipe_name; struct cli_state *cli; POLICY_HND pol; }; static struct winbindd_cm_conn *cm_conns = NULL; /* Get a domain controller name */ static BOOL cm_get_dc_name(const char *domain, fstring srv_name, struct in_addr *ip_out) { struct in_addr *ip_list = NULL, dc_ip, exclude_ip; int count, i; zero_ip(&exclude_ip); /* Lookup domain controller name. Try the real PDC first to avoid SAM sync delays */ if (get_dc_list(True, domain, &ip_list, &count)) { if (name_status_find(domain, 0x1c, 0x20, ip_list[0], srv_name)) { dc_ip = ip_list[0]; goto done; } /* Didn't get name, remember not to talk to this DC. */ exclude_ip = ip_list[0]; SAFE_FREE(ip_list); } if (!get_dc_list(False, domain, &ip_list, &count)) { DEBUG(3, ("Could not look up dc's for domain %s\n", domain)); return False; } /* Remove the entry we've already failed with (should be the PDC). */ for (i = 0; i < count; i++) { if (ip_equal( exclude_ip, ip_list[i])) zero_ip(&ip_list[i]); } /* Pick a nice close server */ /* Look for DC on local net */ for (i = 0; i < count; i++) { if (is_zero_ip(ip_list[i])) continue; if (!is_local_net(ip_list[i])) continue; if (name_status_find(domain, 0x1c, 0x20, ip_list[i], srv_name)) { dc_ip = ip_list[i]; goto done; } zero_ip(&ip_list[i]); } /* * Secondly try and contact a random PDC/BDC. */ i = (sys_random() % count); if (!is_zero_ip(ip_list[i]) && name_status_find(domain, 0x1c, 0x20, ip_list[i], srv_name)) { dc_ip = ip_list[i]; goto done; } zero_ip(&ip_list[i]); /* Tried and failed. */ /* Finally return first DC that we can contact */ for (i = 0; i < count; i++) { if (is_zero_ip(ip_list[i])) continue; if (name_status_find(domain, 0x1c, 0x20, ip_list[i], srv_name)) { dc_ip = ip_list[i]; goto done; } } SAFE_FREE(ip_list); /* No-one to talk to )-: */ return False; /* Boo-hoo */ done: /* We have the netbios name and IP address of a domain controller. Ideally we should sent a SAMLOGON request to determine whether the DC is alive and kicking. If we can catch a dead DC before performing a cli_connect() we can avoid a 30-second timeout. */ DEBUG(3, ("cm_get_dc_name: Returning DC %s (%s) for domain %s\n", srv_name, inet_ntoa(dc_ip), domain)); *ip_out = dc_ip; SAFE_FREE(ip_list); return True; } /* Choose between anonymous or authenticated connections. We need to use an authenticated connection if DCs have the RestrictAnonymous registry entry set > 0, or the "Additional restrictions for anonymous connections" set in the win2k Local Security Policy. Caller to free() result in domain, username, password */ static void cm_get_ipc_userpass(char **username, char **domain, char **password) { *username = secrets_fetch(SECRETS_AUTH_USER, NULL); *domain = secrets_fetch(SECRETS_AUTH_DOMAIN, NULL); *password = secrets_fetch(SECRETS_AUTH_PASSWORD, NULL); if (*username && **username) { if (!*domain || !**domain) { *domain = smb_xstrdup(lp_workgroup()); } DEBUG(3, ("IPC$ connections done by user %s\\%s\n", *domain, *username)); } else { DEBUG(3, ("IPC$ connections done anonymously\n")); *username = smb_xstrdup(""); *domain = smb_xstrdup(""); *password = smb_xstrdup(""); } } /* Open a new smb pipe connection to a DC on a given domain. Cache negative creation attempts so we don't try and connect to broken machines too often. */ #define FAILED_CONNECTION_CACHE_TIMEOUT 30 /* Seconds between attempts */ struct failed_connection_cache { fstring domain_name; fstring controller; time_t lookup_time; NTSTATUS nt_status; struct failed_connection_cache *prev, *next; }; static struct failed_connection_cache *failed_connection_cache; /* Add an entry to the failed conneciton cache */ static void add_failed_connection_entry(struct winbindd_cm_conn *new_conn, NTSTATUS result) { struct failed_connection_cache *fcc; SMB_ASSERT(!NT_STATUS_IS_OK(result)); /* Check we already aren't in the cache */ for (fcc = failed_connection_cache; fcc; fcc = fcc->next) { if (strequal(fcc->domain_name, new_conn->domain)) { DEBUG(10, ("domain %s already tried and failed\n", fcc->domain_name)); return; } } /* Create negative lookup cache entry for this domain and controller */ if (!(fcc = (struct failed_connection_cache *) malloc(sizeof(struct failed_connection_cache)))) { DEBUG(0, ("malloc failed in add_failed_connection_entry!\n")); return; } ZERO_STRUCTP(fcc); fstrcpy(fcc->domain_name, new_conn->domain); fstrcpy(fcc->controller, new_conn->controller); fcc->lookup_time = time(NULL); fcc->nt_status = result; DLIST_ADD(failed_connection_cache, fcc); } /* Open a connction to the remote server, cache failures for 30 seconds */ static NTSTATUS cm_open_connection(const char *domain,const char *pipe_name, struct winbindd_cm_conn *new_conn) { struct failed_connection_cache *fcc; extern pstring global_myname; NTSTATUS result; char *ipc_username, *ipc_domain, *ipc_password; struct in_addr dc_ip; ZERO_STRUCT(dc_ip); fstrcpy(new_conn->domain, domain); fstrcpy(new_conn->pipe_name, pipe_name); /* Look for a domain controller for this domain. Negative results are cached so don't bother applying the caching for this function just yet. */ if (!cm_get_dc_name(domain, new_conn->controller, &dc_ip)) { result = NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND; add_failed_connection_entry(new_conn, result); return result; } /* Return false if we have tried to look up this domain and netbios name before and failed. */ for (fcc = failed_connection_cache; fcc; fcc = fcc->next) { if (!(strequal(domain, fcc->domain_name) && strequal(new_conn->controller, fcc->controller))) continue; /* Not our domain */ if ((time(NULL) - fcc->lookup_time) > FAILED_CONNECTION_CACHE_TIMEOUT) { /* Cache entry has expired, delete it */ DEBUG(10, ("cm_open_connection cache entry expired for %s, %s\n", domain, new_conn->controller)); DLIST_REMOVE(failed_connection_cache, fcc); free(fcc); break; } /* The timeout hasn't expired yet so return false */ DEBUG(10, ("returning negative open_connection_cache entry for %s, %s\n", domain, new_conn->controller)); result = fcc->nt_status; SMB_ASSERT(!NT_STATUS_IS_OK(result)); return result; } /* Initialise SMB connection */ cm_get_ipc_userpass(&ipc_username, &ipc_domain, &ipc_password); DEBUG(5, ("connecting to %s from %s with username [%s]\\[%s]\n", new_conn->controller, global_myname, ipc_domain, ipc_username)); result = cli_full_connection(&(new_conn->cli), global_myname, new_conn->controller, &dc_ip, 0, "IPC$", "IPC", ipc_username, ipc_domain, ipc_password, strlen(ipc_password)); SAFE_FREE(ipc_username); SAFE_FREE(ipc_domain); SAFE_FREE(ipc_password); if (!NT_STATUS_IS_OK(result)) { add_failed_connection_entry(new_conn, result); return result; } if (!cli_nt_session_open (new_conn->cli, pipe_name)) { result = NT_STATUS_PIPE_NOT_AVAILABLE; add_failed_connection_entry(new_conn, result); cli_shutdown(new_conn->cli); return result; } return NT_STATUS_OK; } /* Return true if a connection is still alive */ static BOOL connection_ok(struct winbindd_cm_conn *conn) { if (!conn) { smb_panic("Invalid paramater passed to conneciton_ok(): conn was NULL!\n"); return False; } if (!conn->cli) { DEBUG(0, ("Connection to %s for domain %s (pipe %s) has NULL conn->cli!\n", conn->controller, conn->domain, conn->pipe_name)); smb_panic("connection_ok: conn->cli was null!"); return False; } if (!conn->cli->initialised) { DEBUG(0, ("Connection to %s for domain %s (pipe %s) was never initialised!\n", conn->controller, conn->domain, conn->pipe_name)); smb_panic("connection_ok: conn->cli->initialised is False!"); return False; } if (conn->cli->fd == -1) { DEBUG(3, ("Connection to %s for domain %s (pipe %s) has died or was never started (fd == -1)\n", conn->controller, conn->domain, conn->pipe_name)); return False; } return True; } /* Get a connection to the remote DC and open the pipe. If there is already a connection, use that */ static NTSTATUS get_connection_from_cache(const char *domain, const char *pipe_name, struct winbindd_cm_conn **conn_out) { struct winbindd_cm_conn *conn, conn_temp; NTSTATUS result; for (conn = cm_conns; conn; conn = conn->next) { if (strequal(conn->domain, domain) && strequal(conn->pipe_name, pipe_name)) { if (!connection_ok(conn)) { if (conn->cli) { cli_shutdown(conn->cli); } conn_temp.next = conn->next; DLIST_REMOVE(cm_conns, conn); SAFE_FREE(conn); conn = &conn_temp; /* Just to keep the loop moving */ } else { break; } } } if (!conn) { if (!(conn = (struct winbindd_cm_conn *) malloc(sizeof(struct winbindd_cm_conn)))) return NT_STATUS_NO_MEMORY; ZERO_STRUCTP(conn); if (!NT_STATUS_IS_OK(result = cm_open_connection(domain, pipe_name, conn))) { DEBUG(3, ("Could not open a connection to %s for %s (%s)\n", domain, pipe_name, nt_errstr(result))); SAFE_FREE(conn); return result; } DLIST_ADD(cm_conns, conn); } *conn_out = conn; return NT_STATUS_OK; } /* Return a LSA policy handle on a domain */ NTSTATUS cm_get_lsa_handle(char *domain, CLI_POLICY_HND **return_hnd) { struct winbindd_cm_conn *conn; uint32 des_access = SEC_RIGHTS_MAXIMUM_ALLOWED; NTSTATUS result; static CLI_POLICY_HND hnd; /* Look for existing connections */ if (!NT_STATUS_IS_OK(result = get_connection_from_cache(domain, PIPE_LSARPC, &conn))) return result; /* This *shitty* code needs scrapping ! JRA */ if (policy_handle_is_valid(&conn->pol)) { hnd.pol = conn->pol; hnd.cli = conn->cli; *return_hnd = &hnd; return NT_STATUS_OK; } result = cli_lsa_open_policy(conn->cli, conn->cli->mem_ctx, False, des_access, &conn->pol); if (!NT_STATUS_IS_OK(result)) { /* Hit the cache code again. This cleans out the old connection and gets a new one */ if (conn->cli->fd == -1) { /* Try again, if the remote host disapeared */ if (!NT_STATUS_IS_OK(result = get_connection_from_cache(domain, PIPE_LSARPC, &conn))) return result; result = cli_lsa_open_policy(conn->cli, conn->cli->mem_ctx, False, des_access, &conn->pol); } if (!NT_STATUS_IS_OK(result)) { cli_shutdown(conn->cli); DLIST_REMOVE(cm_conns, conn); SAFE_FREE(conn); return result; } } hnd.pol = conn->pol; hnd.cli = conn->cli; *return_hnd = &hnd; return NT_STATUS_OK; } /* Return a SAM policy handle on a domain */ NTSTATUS cm_get_sam_handle(char *domain, CLI_POLICY_HND **return_hnd) { struct winbindd_cm_conn *conn; uint32 des_access = SEC_RIGHTS_MAXIMUM_ALLOWED; NTSTATUS result; static CLI_POLICY_HND hnd; /* Look for existing connections */ if (!NT_STATUS_IS_OK(result = get_connection_from_cache(domain, PIPE_SAMR, &conn))) return result; /* This *shitty* code needs scrapping ! JRA */ if (policy_handle_is_valid(&conn->pol)) { hnd.pol = conn->pol; hnd.cli = conn->cli; *return_hnd = &hnd; return NT_STATUS_OK; } result = cli_samr_connect(conn->cli, conn->cli->mem_ctx, des_access, &conn->pol); if (!NT_STATUS_IS_OK(result)) { /* Hit the cache code again. This cleans out the old connection and gets a new one */ if (conn->cli->fd == -1) { /* Try again, if the remote host disapeared */ if (!NT_STATUS_IS_OK(result = get_connection_from_cache(domain, PIPE_SAMR, &conn))) return result; result = cli_samr_connect(conn->cli, conn->cli->mem_ctx, des_access, &conn->pol); } if (!NT_STATUS_IS_OK(result)) { cli_shutdown(conn->cli); DLIST_REMOVE(cm_conns, conn); SAFE_FREE(conn); return result; } } hnd.pol = conn->pol; hnd.cli = conn->cli; *return_hnd = &hnd; return NT_STATUS_OK; } #if 0 /* This code now *well* out of date */ /* Return a SAM domain policy handle on a domain */ CLI_POLICY_HND *cm_get_sam_dom_handle(char *domain, DOM_SID *domain_sid) { struct winbindd_cm_conn *conn, *basic_conn = NULL; static CLI_POLICY_HND hnd; NTSTATUS result; uint32 des_access = SEC_RIGHTS_MAXIMUM_ALLOWED; /* Look for existing connections */ for (conn = cm_conns; conn; conn = conn->next) { if (strequal(conn->domain, domain) && strequal(conn->pipe_name, PIPE_SAMR) && conn->pipe_data.samr.pipe_type == SAM_PIPE_DOM) { if (!connection_ok(conn)) { /* Shutdown cli? Free conn? Allow retry of DC? */ DLIST_REMOVE(cm_conns, conn); return NULL; } goto ok; } } /* Create a basic handle to open a domain handle from */ if (!cm_get_sam_handle(domain)) return False; for (conn = cm_conns; conn; conn = conn->next) { if (strequal(conn->domain, domain) && strequal(conn->pipe_name, PIPE_SAMR) && conn->pipe_data.samr.pipe_type == SAM_PIPE_BASIC) basic_conn = conn; } if (!(conn = (struct winbindd_cm_conn *) malloc(sizeof(struct winbindd_cm_conn)))) return NULL; ZERO_STRUCTP(conn); fstrcpy(conn->domain, basic_conn->domain); fstrcpy(conn->controller, basic_conn->controller); fstrcpy(conn->pipe_name, basic_conn->pipe_name); conn->pipe_data.samr.pipe_type = SAM_PIPE_DOM; conn->cli = basic_conn->cli; result = cli_samr_open_domain(conn->cli, conn->cli->mem_ctx, &basic_conn->pol, des_access, domain_sid, &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 user */ CLI_POLICY_HND *cm_get_sam_user_handle(char *domain, DOM_SID *domain_sid, uint32 user_rid) { struct winbindd_cm_conn *conn, *basic_conn = NULL; static CLI_POLICY_HND hnd; NTSTATUS result; uint32 des_access = SEC_RIGHTS_MAXIMUM_ALLOWED; /* Look for existing connections */ for (conn = cm_conns; conn; conn = conn->next) { if (strequal(conn->domain, domain) && strequal(conn->pipe_name, PIPE_SAMR) && conn->pipe_data.samr.pipe_type == SAM_PIPE_USER && conn->pipe_data.samr.rid == user_rid) { if (!connection_ok(conn)) { /* Shutdown cli? Free conn? Allow retry of DC? */ DLIST_REMOVE(cm_conns, conn); return NULL; } goto ok; } } /* Create a domain handle to open a user handle from */ if (!cm_get_sam_dom_handle(domain, domain_sid)) return NULL; for (conn = cm_conns; conn; conn = conn->next) { if (strequal(conn->domain, domain) && strequal(conn->pipe_name, PIPE_SAMR) && conn->pipe_data.samr.pipe_type == SAM_PIPE_DOM) basic_conn = conn; } if (!basic_conn) { DEBUG(0, ("No domain sam handle was created!\n")); return NULL; } if (!(conn = (struct winbindd_cm_conn *) malloc(sizeof(struct winbindd_cm_conn)))) return NULL; ZERO_STRUCTP(conn); fstrcpy(conn->domain, basic_conn->domain); fstrcpy(conn->controller, basic_conn->controller); fstrcpy(conn->pipe_name, basic_conn->pipe_name); conn->pipe_data.samr.pipe_type = SAM_PIPE_USER; conn->cli = basic_conn->cli; conn->pipe_data.samr.rid = user_rid; result = cli_samr_open_user(conn->cli, conn->cli->mem_ctx, &basic_conn->pol, des_access, user_rid, &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 group */ CLI_POLICY_HND *cm_get_sam_group_handle(char *domain, DOM_SID *domain_sid, uint32 group_rid) { struct winbindd_cm_conn *conn, *basic_conn = NULL; static CLI_POLICY_HND hnd; NTSTATUS result; uint32 des_access = SEC_RIGHTS_MAXIMUM_ALLOWED; /* Look for existing connections */ for (conn = cm_conns; conn; conn = conn->next) { if (strequal(conn->domain, domain) && strequal(conn->pipe_name, PIPE_SAMR) && conn->pipe_data.samr.pipe_type == SAM_PIPE_GROUP && conn->pipe_data.samr.rid == group_rid) { if (!connection_ok(conn)) { /* Shutdown cli? Free conn? Allow retry of DC? */ DLIST_REMOVE(cm_conns, conn); return NULL; } goto ok; } } /* Create a domain handle to open a user handle from */ if (!cm_get_sam_dom_handle(domain, domain_sid)) return NULL; for (conn = cm_conns; conn; conn = conn->next) { if (strequal(conn->domain, domain) && strequal(conn->pipe_name, PIPE_SAMR) && conn->pipe_data.samr.pipe_type == SAM_PIPE_DOM) basic_conn = conn; } if (!basic_conn) { DEBUG(0, ("No domain sam handle was created!\n")); return NULL; } if (!(conn = (struct winbindd_cm_conn *) malloc(sizeof(struct winbindd_cm_conn)))) return NULL; ZERO_STRUCTP(conn); fstrcpy(conn->domain, basic_conn->domain); fstrcpy(conn->controller, basic_conn->controller); fstrcpy(conn->pipe_name, basic_conn->pipe_name); conn->pipe_data.samr.pipe_type = SAM_PIPE_GROUP; conn->cli = basic_conn->cli; conn->pipe_data.samr.rid = group_rid; result = cli_samr_open_group(conn->cli, conn->cli->mem_ctx, &basic_conn->pol, des_access, group_rid, &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; } #endif /* Get a handle on a netlogon pipe. This is a bit of a hack to re-use the netlogon pipe as no handle is returned. */ NTSTATUS cm_get_netlogon_cli(char *domain, unsigned char *trust_passwd, struct cli_state **cli) { NTSTATUS result = NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND; struct winbindd_cm_conn *conn; if (!cli) { return NT_STATUS_INVALID_PARAMETER; } /* Open an initial conection */ if (!NT_STATUS_IS_OK(result = get_connection_from_cache(domain, PIPE_NETLOGON, &conn))) { return result; } result = new_cli_nt_setup_creds(conn->cli, (lp_server_role() == ROLE_DOMAIN_MEMBER) ? SEC_CHAN_WKSTA : SEC_CHAN_BDC, trust_passwd); if (!NT_STATUS_IS_OK(result)) { DEBUG(0, ("error connecting to domain password server: %s\n", nt_errstr(result))); /* Hit the cache code again. This cleans out the old connection and gets a new one */ if (conn->cli->fd == -1) { if (!NT_STATUS_IS_OK(result = get_connection_from_cache(domain, PIPE_NETLOGON, &conn))) { return result; } /* Try again */ result = new_cli_nt_setup_creds(conn->cli, (lp_server_role() == ROLE_DOMAIN_MEMBER) ? SEC_CHAN_WKSTA : SEC_CHAN_BDC, trust_passwd); } if (!NT_STATUS_IS_OK(result)) { cli_shutdown(conn->cli); DLIST_REMOVE(cm_conns, conn); SAFE_FREE(conn); return result; } } *cli = conn->cli; return result; } /* Dump the current connection status */ static void dump_conn_list(void) { struct winbindd_cm_conn *con; DEBUG(0, ("\tDomain Controller Pipe\n")); for(con = cm_conns; con; con = con->next) { char *msg; /* Display pipe info */ if (asprintf(&msg, "\t%-15s %-15s %-16s", con->domain, con->controller, con->pipe_name) < 0) { DEBUG(0, ("Error: not enough memory!\n")); } else { DEBUG(0, ("%s\n", msg)); SAFE_FREE(msg); } } } void winbindd_cm_status(void) { /* List open connections */ DEBUG(0, ("winbindd connection manager status:\n")); if (cm_conns) dump_conn_list(); else DEBUG(0, ("\tNo active connections\n")); } /* Close all cached connections */ void winbindd_cm_flush(void) { struct winbindd_cm_conn *conn, tmp; for (conn = cm_conns; conn; conn = conn->next) { if (!connection_ok(conn)) continue; DEBUG(10, ("Closing connection to %s on %s\n", conn->pipe_name, conn->controller)); if (conn->cli) cli_shutdown(conn->cli); tmp.next = conn->next; DLIST_REMOVE(cm_conns, conn); SAFE_FREE(conn); conn = &tmp; } }