/* Unix SMB/CIFS implementation. Winbind daemon connection manager Copyright (C) Tim Potter 2001 Copyright (C) Andrew Bartlett 2002 Copyright (C) Gerald (Jerry) Carter 2003 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 3 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, see <http://www.gnu.org/licenses/>. */ #include "includes.h" #define CONNCACHE_ADDR 1 #define CONNCACHE_NAME 2 /* cache entry contains either a server name **or** and IP address as the key. This means that a server could have two entries (one for each key) */ 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; /********************************************************************** Check for a previously failed connection. failed_cache_timeout is an a absolute number of seconds after which we should time this out. If failed_cache_timeout == 0 then time out immediately. If failed_cache_timeout == -1 then never time out. **********************************************************************/ NTSTATUS check_negative_conn_cache_timeout( const char *domain, const char *server, unsigned int failed_cache_timeout ) { struct failed_connection_cache *fcc; NTSTATUS result = NT_STATUS_UNSUCCESSFUL; /* can't check if we don't have strings */ if ( !domain || !server ) return NT_STATUS_OK; for (fcc = failed_connection_cache; fcc; fcc = fcc->next) { if (!(strequal(domain, fcc->domain_name) && strequal(server, fcc->controller))) { continue; /* no match; check the next entry */ } /* we have a match so see if it is still current */ if (failed_cache_timeout != (unsigned int)-1) { if (failed_cache_timeout == 0 || (time(NULL) - fcc->lookup_time) > (time_t)failed_cache_timeout) { /* Cache entry has expired, delete it */ DEBUG(10, ("check_negative_conn_cache: cache entry expired for %s, %s\n", domain, server )); DLIST_REMOVE(failed_connection_cache, fcc); SAFE_FREE(fcc); return NT_STATUS_OK; } } /* The timeout hasn't expired yet so return false */ DEBUG(10, ("check_negative_conn_cache: returning negative entry for %s, %s\n", domain, server )); result = fcc->nt_status; return result; } /* end of function means no cache entry */ return NT_STATUS_OK; } NTSTATUS check_negative_conn_cache( const char *domain, const char *server) { return check_negative_conn_cache_timeout(domain, server, FAILED_CONNECTION_CACHE_TIMEOUT); } /********************************************************************** Add an entry to the failed conneciton cache (aither a name of dotted decimal IP **********************************************************************/ void add_failed_connection_entry(const char *domain, const char *server, NTSTATUS result) { struct failed_connection_cache *fcc; SMB_ASSERT(!NT_STATUS_IS_OK(result)); /* Check we already aren't in the cache. We always have to have a domain, but maybe not a specific DC name. */ for (fcc = failed_connection_cache; fcc; fcc = fcc->next) { if ( strequal(fcc->domain_name, domain) && strequal(fcc->controller, server) ) { DEBUG(10, ("add_failed_connection_entry: domain %s (%s) already tried and failed\n", domain, server )); /* Update the failed time. */ fcc->lookup_time = time(NULL); return; } } /* Create negative lookup cache entry for this domain and controller */ if ( !(fcc = SMB_MALLOC_P(struct failed_connection_cache)) ) { DEBUG(0, ("malloc failed in add_failed_connection_entry!\n")); return; } ZERO_STRUCTP(fcc); fstrcpy( fcc->domain_name, domain ); fstrcpy( fcc->controller, server ); fcc->lookup_time = time(NULL); fcc->nt_status = result; DEBUG(10,("add_failed_connection_entry: added domain %s (%s) to failed conn cache\n", domain, server )); DLIST_ADD(failed_connection_cache, fcc); } /**************************************************************************** ****************************************************************************/ void flush_negative_conn_cache( void ) { struct failed_connection_cache *fcc; fcc = failed_connection_cache; while (fcc) { struct failed_connection_cache *fcc_next; fcc_next = fcc->next; DLIST_REMOVE(failed_connection_cache, fcc); free(fcc); fcc = fcc_next; } } /**************************************************************************** Remove all negative entries for a domain. Used when going to online state in winbindd. ****************************************************************************/ void flush_negative_conn_cache_for_domain(const char *domain) { struct failed_connection_cache *fcc; fcc = failed_connection_cache; while (fcc) { struct failed_connection_cache *fcc_next; fcc_next = fcc->next; if (strequal(fcc->domain_name, domain)) { DEBUG(10,("flush_negative_conn_cache_for_domain: removed server %s " " from failed cache for domain %s\n", fcc->controller, domain)); DLIST_REMOVE(failed_connection_cache, fcc); free(fcc); } fcc = fcc_next; } }