1/* 2 Unix SMB/CIFS implementation. 3 4 Winbind daemon connection manager 5 6 Copyright (C) Tim Potter 2001 7 Copyright (C) Andrew Bartlett 2002 8 Copyright (C) Gerald (Jerry) Carter 2003 9 10 This program is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 2 of the License, or 13 (at your option) any later version. 14 15 This program is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with this program; if not, write to the Free Software 22 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 23*/ 24 25 26#include "includes.h" 27 28#define CONNCACHE_ADDR 1 29#define CONNCACHE_NAME 2 30 31/* cache entry contains either a server name **or** and IP address as 32 the key. This means that a server could have two entries (one for each key) */ 33 34struct failed_connection_cache { 35 fstring domain_name; 36 fstring controller; 37 time_t lookup_time; 38 NTSTATUS nt_status; 39 struct failed_connection_cache *prev, *next; 40}; 41 42static struct failed_connection_cache *failed_connection_cache; 43 44/********************************************************************** 45 Check for a previously failed connection. 46 failed_cache_timeout is an a absolute number of seconds after which 47 we should time this out. If failed_cache_timeout == 0 then time out 48 immediately. If failed_cache_timeout == -1 then never time out. 49**********************************************************************/ 50 51NTSTATUS check_negative_conn_cache_timeout( const char *domain, const char *server, unsigned int failed_cache_timeout ) 52{ 53 struct failed_connection_cache *fcc; 54 NTSTATUS result = NT_STATUS_UNSUCCESSFUL; 55 56 /* can't check if we don't have strings */ 57 58 if ( !domain || !server ) 59 return NT_STATUS_OK; 60 61 for (fcc = failed_connection_cache; fcc; fcc = fcc->next) { 62 63 if (!(strequal(domain, fcc->domain_name) && strequal(server, fcc->controller))) { 64 continue; /* no match; check the next entry */ 65 } 66 67 /* we have a match so see if it is still current */ 68 if (failed_cache_timeout != (unsigned int)-1) { 69 if (failed_cache_timeout == 0 || 70 (time(NULL) - fcc->lookup_time) > (time_t)failed_cache_timeout) { 71 /* Cache entry has expired, delete it */ 72 73 DEBUG(10, ("check_negative_conn_cache: cache entry expired for %s, %s\n", 74 domain, server )); 75 76 DLIST_REMOVE(failed_connection_cache, fcc); 77 SAFE_FREE(fcc); 78 79 return NT_STATUS_OK; 80 } 81 } 82 83 /* The timeout hasn't expired yet so return false */ 84 85 DEBUG(10, ("check_negative_conn_cache: returning negative entry for %s, %s\n", 86 domain, server )); 87 88 result = fcc->nt_status; 89 return result; 90 } 91 92 /* end of function means no cache entry */ 93 return NT_STATUS_OK; 94} 95 96NTSTATUS check_negative_conn_cache( const char *domain, const char *server) 97{ 98 return check_negative_conn_cache_timeout(domain, server, FAILED_CONNECTION_CACHE_TIMEOUT); 99} 100 101/********************************************************************** 102 Add an entry to the failed conneciton cache (aither a name of dotted 103 decimal IP 104**********************************************************************/ 105 106void add_failed_connection_entry(const char *domain, const char *server, NTSTATUS result) 107{ 108 struct failed_connection_cache *fcc; 109 110 SMB_ASSERT(!NT_STATUS_IS_OK(result)); 111 112 /* Check we already aren't in the cache. We always have to have 113 a domain, but maybe not a specific DC name. */ 114 115 for (fcc = failed_connection_cache; fcc; fcc = fcc->next) { 116 if ( strequal(fcc->domain_name, domain) && strequal(fcc->controller, server) ) { 117 DEBUG(10, ("add_failed_connection_entry: domain %s (%s) already tried and failed\n", 118 domain, server )); 119 /* Update the failed time. */ 120 fcc->lookup_time = time(NULL); 121 return; 122 } 123 } 124 125 /* Create negative lookup cache entry for this domain and controller */ 126 127 if ( !(fcc = SMB_MALLOC_P(struct failed_connection_cache)) ) { 128 DEBUG(0, ("malloc failed in add_failed_connection_entry!\n")); 129 return; 130 } 131 132 ZERO_STRUCTP(fcc); 133 134 fstrcpy( fcc->domain_name, domain ); 135 fstrcpy( fcc->controller, server ); 136 fcc->lookup_time = time(NULL); 137 fcc->nt_status = result; 138 139 DEBUG(10,("add_failed_connection_entry: added domain %s (%s) to failed conn cache\n", 140 domain, server )); 141 142 DLIST_ADD(failed_connection_cache, fcc); 143} 144 145/**************************************************************************** 146****************************************************************************/ 147 148void flush_negative_conn_cache( void ) 149{ 150 struct failed_connection_cache *fcc; 151 152 fcc = failed_connection_cache; 153 154 while (fcc) { 155 struct failed_connection_cache *fcc_next; 156 157 fcc_next = fcc->next; 158 DLIST_REMOVE(failed_connection_cache, fcc); 159 free(fcc); 160 161 fcc = fcc_next; 162 } 163 164} 165 166/**************************************************************************** 167 Remove all negative entries for a domain. Used when going to online state in 168 winbindd. 169****************************************************************************/ 170 171void flush_negative_conn_cache_for_domain(const char *domain) 172{ 173 struct failed_connection_cache *fcc; 174 175 fcc = failed_connection_cache; 176 177 while (fcc) { 178 struct failed_connection_cache *fcc_next; 179 180 fcc_next = fcc->next; 181 182 if (strequal(fcc->domain_name, domain)) { 183 DEBUG(10,("flush_negative_conn_cache_for_domain: removed server %s " 184 " from failed cache for domain %s\n", 185 fcc->controller, domain)); 186 DLIST_REMOVE(failed_connection_cache, fcc); 187 free(fcc); 188 } 189 190 fcc = fcc_next; 191 } 192} 193