chiark - git - mdw - exim-config/blob - base.m4

   1 ### -*-m4-*-
   2 ###
   3 ### Basic settings for distorted.org.uk Exim configuration
   4 ###
   5 ### (c) 2012 Mark Wooding
   6 ###
   7
   8 ###----- Licensing notice ---------------------------------------------------
   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 Foundation,
  22 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23
  24 ###--------------------------------------------------------------------------
  25 ### Global settings.
  26
  27 SECTION(global, priv)m4_dnl
  28 admin_groups = CONF_admin_groups
  29 prod_requires_admin = false
  30
  31 SECTION(global, logging)m4_dnl
  32 log_file_path = : syslog
  33 log_selector = \
  34         +smtp_confirmation \
  35         +tls_peerdn
  36 log_timezone = true
  37 syslog_duplication = false
  38 syslog_timestamp = false
  39
  40 SECTION(global, daemon)m4_dnl
  41 local_interfaces = <; CONF_interfaces
  42 extra_local_interfaces = <; 0.0.0.0 ; ::
  43
  44 SECTION(global, resource)m4_dnl
  45 deliver_queue_load_max = 8
  46 queue_only_load = 12
  47 smtp_accept_max = 16
  48 smtp_accept_queue = 32
  49 smtp_accept_reserve = 4
  50 smtp_load_reserve = 10
  51 smtp_reserve_hosts = +trusted
  52
  53 SECTION(global, policy)m4_dnl
  54 host_lookup = *
  55
  56 SECTION(global, users)m4_dnl
  57 gecos_name = $1
  58 gecos_pattern = ([^,:]*)
  59
  60 SECTION(global, incoming)m4_dnl
  61 received_header_text = Received: \
  62         ${if def:sender_rcvhost \
  63              {from $sender_rcvhost\n\t} \
  64              {${if def:sender_ident \
  65                    {from ${quote_local_part:$sender_ident} }}}}\
  66         by $primary_hostname \
  67         (Exim $version_number)\
  68         ${if def:tls_cipher {\n\t} { }}\
  69         ${if def:received_protocol \
  70              {with $received_protocol \
  71               ${if def:tls_cipher {(cipher=$tls_cipher)}}}}\n\t\
  72         ${if def:sender_address \
  73              {(envelope-from $sender_address\
  74               ${if def:authenticated_id \
  75                    {; auth=$authenticated_id}})\n\t}}\
  76         id $message_exim_id\
  77         ${if def:received_for {\n\tfor $received_for}}
  78
  79 SECTION(global, smtp)m4_dnl
  80 smtp_return_error_details = true
  81 accept_8bitmime = true
  82
  83 SECTION(global, process)m4_dnl
  84 extract_addresses_remove_arguments = false
  85 headers_charset = utf-8
  86 qualify_domain = CONF_master_domain
  87
  88 SECTION(global, bounce)m4_dnl
  89 delay_warning = 1h : 24h : 2d
  90
  91 SECTION(global, tls)m4_dnl
  92 tls_certificate = CONF_sysconf_dir/server.cert
  93 tls_privatekey = CONF_sysconf_dir/server.key
  94 tls_advertise_hosts = ${if exists {CONF_sysconf_dir/server.key} {*}{}}
  95 tls_dhparam = CONF_ca_dir/dh-param-2048.pem
  96 tls_require_ciphers = ${if or {{={$received_port}{CONF_submission_port}} \
  97                                {match_ip {$sender_host_address}{+trusted}}} \
  98                            {CONF_good_ciphers} \
  99                            {CONF_acceptable_ciphers}}
 100 tls_verify_certificates = CONF_ca_dir/ca.cert
 101 tls_verify_hosts = ${if eq{$acl_c_mode}{submission} {} {+allnets}}
 102
 103 DIVERT(null)
 104 ###--------------------------------------------------------------------------
 105 ### Access control lists.
 106
 107 SECTION(global, acl-after)
 108 SECTION(global, acl)m4_dnl
 109 acl_smtp_helo = helo
 110 SECTION(acl, misc)m4_dnl
 111 helo:
 112         ## Check that the caller's claimed identity is actually plausible.
 113         ## This seems like it's a fairly effective filter on spamminess, but
 114         ## it's too blunt a tool.  Rather than reject, add a warning header.
 115         ## Only we can't do this the easy way, so save it up for use in MAIL.
 116         ## Also, we're liable to get a subsequent HELO (e.g., after STARTTLS)
 117         ## and we should only care about the most recent one.
 118         warn     set acl_c_helo_warning = false
 119                 !condition = \
 120                         ${if and {{match_ip {$sender_host_address} \
 121                                             {<; 127.0.0.0/8 ; ::1}} \
 122                                   {match_domain {$sender_helo_name} \
 123                                                 {localhost : +thishost}}}}
 124                 !condition = \
 125                         ${if exists {CONF_sysconf_dir/helo.conf} \
 126                              {${lookup {$sender_helo_name} \
 127                                        partial0-lsearch \
 128                                        {CONF_sysconf_dir/helo.conf} \
 129                                        {${if match_ip \
 130                                              {$sender_host_address} \
 131                                              {$value}}}}}}
 132                 !verify = helo
 133                  set acl_c_helo_warning = true
 134
 135         accept
 136
 137 SECTION(global, acl)m4_dnl
 138 acl_not_smtp_start = not_smtp_start
 139 SECTION(acl, misc)m4_dnl
 140 not_smtp_start:
 141         ## Record the user's name.
 142         warn     set acl_c_user = $sender_ident
 143
 144         ## Done.
 145         accept
 146
 147 SECTION(global, acl)m4_dnl
 148 acl_smtp_mail = mail
 149 SECTION(acl, mail)m4_dnl
 150 mail:
 151
 152         ## If we stashed a warning header about HELO from earlier, we should
 153         ## add it now.
 154         warn     condition = $acl_c_helo_warning
 155                  add_header = :after_received:X-Distorted-Warning: \
 156                         BADHELO \
 157                         Client's HELO doesn't match its IP address.\n\t\
 158                         helo-name=$sender_helo_name \
 159                         address=$sender_host_address
 160
 161         ## Always allow the empty sender, so that we can receive bounces.
 162         accept   senders = :
 163
 164         ## Ensure that the sender is routable.  This is important to prevent
 165         ## undeliverable bounces.
 166         require  message = Invalid sender; \
 167                         ($sender_verify_failure; $acl_verify_message)
 168                  verify = sender
 169
 170         ## If this is directly from a client then hack on it for a while.
 171         warn     condition = ${if eq{$acl_c_mode}{submission}}
 172                  control = submission
 173
 174         ## Insist that a local client connect through TLS.
 175         deny     message = Hosts within CONF_master_domain must use TLS
 176                 !condition = ${if eq{$acl_c_mode}{submission}}
 177                  hosts = +allnets
 178                 !encrypted = *
 179
 180         ## Check that a submitted message's sender address is allowable.
 181         require  acl = mail_check_auth
 182
 183 SECTION(acl, mail-tail)m4_dnl
 184         ## And we're done.
 185         accept
 186
 187 SECTION(global, acl)m4_dnl
 188 acl_smtp_connect = connect
 189 SECTION(acl, connect)m4_dnl
 190 connect:
 191 SECTION(acl, connect-tail)m4_dnl
 192         ## Configure variables according to the submission mode.
 193         warn     acl = check_submission
 194
 195         ## Done.
 196         accept
 197
 198 check_submission:
 199         ## See whether this message needs hacking on.
 200         accept  !hosts = +thishost
 201                 !condition = ${if ={$received_port}{CONF_submission_port}}
 202                  set acl_c_mode = relay
 203
 204         ## Remember to apply submission controls.
 205         warn     set acl_c_mode = submission
 206
 207         ## Done.
 208         accept
 209
 210 SECTION(global, acl)m4_dnl
 211 acl_smtp_rcpt = rcpt
 212 SECTION(acl, rcpt)m4_dnl
 213 rcpt:
 214
 215         ## Reject if the client isn't allowed to relay and the recipient
 216         ## isn't in one of our known domains.
 217         deny     message = Relaying not permitted
 218                 !hosts = CONF_relay_clients
 219                 !authenticated = *
 220                 !domains = +known
 221
 222         ## Ensure that the recipient is routable.
 223         require  message = Invalid recipient \
 224                         ($recipient_verify_failure; $acl_verify_message)
 225                  verify = recipient
 226
 227 SECTION(acl, rcpt-tail)m4_dnl
 228         ## Everything checks out OK: let this one go through.
 229         accept
 230
 231 SECTION(global, acl)m4_dnl
 232 acl_smtp_data = data
 233 SECTION(acl, data)m4_dnl
 234 data:
 235
 236 SECTION(acl, data-tail)m4_dnl
 237         accept
 238
 239 SECTION(global, acl)m4_dnl
 240 acl_smtp_expn = expn_vrfy
 241 acl_smtp_vrfy = expn_vrfy
 242 SECTION(acl)m4_dnl
 243 expn_vrfy:
 244         accept   hosts = +trusted
 245         deny     message = Suck it and see
 246
 247 DIVERT(null)
 248 ###--------------------------------------------------------------------------
 249 ### Verification of sender address.
 250
 251 SECTION(acl, misc)m4_dnl
 252 mail_check_auth:
 253
 254         ## If this isn't a submission then it doesn't need checking.
 255         accept   condition = ${if !eq{$acl_c_mode}{submission}}
 256
 257         ## If the caller hasn't formally authenticated, but this is a
 258         ## loopback connection, then we can trust identd to tell us the right
 259         ## answer.  So we should stash the right name somewhere consistent.
 260         warn     set acl_c_user = $authenticated_id
 261                  hosts = +thishost
 262                 !authenticated = *
 263                  condition = ${if def:sender_ident}
 264                  set acl_c_user = $sender_ident
 265
 266         ## User must be authenticated by now.
 267         deny     message = Sender not authenticated
 268                  condition = ${if !def:acl_c_user}
 269
 270         ## Make sure that the local part is one that the authenticated sender
 271         ## is allowed to claim.
 272         deny     message = Sender address forbidden to calling user
 273                 !condition = \
 274                         ${if exists {CONF_sysconf_dir/auth-sender.conf} \
 275                              {${lookup {$acl_c_user} \
 276                                        lsearch \
 277                                        {CONF_sysconf_dir/auth-sender.conf} \
 278                                        {${if match_address \
 279                                              {$sender_address} \
 280                                              {+value}}} \
 281                                        {false}}}}
 282                 !condition = ${LOOKUP_DOMAIN($sender_address_domain,
 283                                {${if and {{match_local_part \
 284                                             {$acl_c_user} \
 285                                             {+dom_users}} \
 286                                           {match_local_part \
 287                                             {$sender_address_local_part} \
 288                                             {+dom_locals}}}}},
 289                                {${if and {{match_local_part \
 290                                             {$sender_address_local_part} \
 291                                             {+user_extaddr}} \
 292                                           {or {{eq {$sender_address_domain} \
 293                                                    {}} \
 294                                                {match_domain \
 295                                                  {$sender_address_domain} \
 296                                                  {+public}}}}}}})}
 297
 298         ## All done.
 299         accept
 300
 301 DIVERT(null)
 302 ###--------------------------------------------------------------------------
 303 ### Common options for forwarding routers.
 304
 305 ## We're pretty permissive here.
 306 m4_define(<:FILTER_BASE:>,
 307         <:driver = redirect
 308         modemask = 002
 309         check_owner = false
 310         check_group = false
 311         allow_filter = true
 312         allow_defer = true
 313         allow_fail = true
 314         forbid_blackhole = false
 315         check_ancestor = true:>)
 316
 317 ## Common options for forwarding routers at verification time.
 318 m4_define(<:FILTER_VERIFY:>,
 319         <:verify_only = true
 320         user = CONF_filter_user
 321         forbid_filter_dlfunc = true
 322         forbid_filter_logwrite = true
 323         forbid_filter_perl = true
 324         forbid_filter_readsocket = true
 325         forbid_filter_run = true
 326         file_transport = dummy
 327         directory_transport = dummy
 328         pipe_transport = dummy
 329         reply_transport = dummy:>)
 330
 331 ## Transports for redirection filters.
 332 m4_define(<:FILTER_TRANSPORTS:>,
 333         <:file_transport = mailbox
 334         directory_transport = maildir
 335         pipe_transport = pipe
 336         reply_transport = reply:>)
 337
 338 m4_define(<:FILTER_ROUTER:>,
 339 <:$1_vrf:
 340         $2
 341         FILTER_VERIFY<::>$3
 342 $1:
 343         $2
 344         verify = no
 345         FILTER_TRANSPORTS<::>$4:>)
 346
 347 DIVERT(null)
 348 ###--------------------------------------------------------------------------
 349 ### Some standard transports.
 350
 351 m4_define(<:USER_DELIVERY:>,
 352         <:delivery_date_add = true
 353         envelope_to_add = true
 354         return_path_add = true:>)
 355
 356 SECTION(transports)m4_dnl
 357 ## A standard transport for remote delivery.  By default, try to do TLS, and
 358 ## don't worry too much if it's not very secure: the alternative is sending
 359 ## in plaintext anyway.  But all of this can be overridden from the
 360 ## `domains.conf' file.  Annoyingly, the `tls_dh_min_bits' setting isn't
 361 ## expanded before use, so we can't set it the obvious way.  Instead, encode
 362 ## it into the transport name.  This is very unpleasant, of course.
 363 smtp:
 364         driver = smtp
 365         tls_require_ciphers = CONF_acceptable_ciphers
 366         tls_dh_min_bits = 1020
 367         tls_tempfail_tryclear = true
 368
 369 m4_define(<:SMTP_TRANS_DHBITS:>,
 370         <:driver = smtp
 371         hosts_try_auth = *
 372         hosts_require_tls = DOMKV(tls-peer-ca, {*}{})
 373         hosts_require_auth = \
 374                 ${if bool {DOMKV(require-auth, {$value}{false})} {*}{}}
 375         tls_certificate = DOMKV(tls-certificate, {${expand:$value}}fail)
 376         tls_privatekey = DOMKV(tls-private-key, {${expand:$value}}fail)
 377         tls_verify_certificates = DOMKV(tls-peer-ca, {${expand:$value}}fail)
 378         tls_require_ciphers = \
 379                 DOMKV(tls-ciphers,
 380                       {${extract {${expand:$value}} \
 381                                  { good = CONF_good_ciphers \
 382                                    any = CONF_acceptable_ciphers } \
 383                                  {$value} \
 384                                  {${expand:$value}}}} \
 385                       {CONF_acceptable_ciphers})
 386         tls_dh_min_bits = $1
 387         tls_tempfail_tryclear = true:>)m4_dnl
 388 smtp_dhbits_1024:
 389         SMTP_TRANS_DHBITS(1020)
 390 smtp_dhbits_2048:
 391         SMTP_TRANS_DHBITS(2046)
 392
 393 ## Transport to a local SMTP server; use TLS and perform client
 394 ## authentication.
 395 smtp_local:
 396         driver = smtp
 397         hosts_require_tls = *
 398         tls_certificate = CONF_sysconf_dir/client.cert
 399         tls_privatekey = CONF_sysconf_dir/client.key
 400         tls_verify_certificates = CONF_ca_dir/ca.cert
 401         tls_require_ciphers = CONF_good_ciphers
 402         tls_dh_min_bits = 2046
 403         tls_tempfail_tryclear = false
 404         authenticated_sender = ${if def:authenticated_id \
 405                                     {$authenticated_id@CONF_master_domain} \
 406                                     fail}
 407
 408 ## A standard transport for local delivery.
 409 deliver:
 410         driver = appendfile
 411         file = /var/mail/$local_part
 412         group = mail
 413         mode = 0600
 414         mode_fail_narrower = false
 415         USER_DELIVERY
 416
 417 ## Transports for user filters.
 418 mailbox:
 419         driver = appendfile
 420         initgroups = true
 421         USER_DELIVERY
 422
 423 maildir:
 424         driver = appendfile
 425         maildir_format = true
 426         initgroups = true
 427         USER_DELIVERY
 428
 429 pipe:
 430         driver = pipe
 431         path = ${if and {{def:home} {exists{$home/bin}}} {$home/bin:} {}}\
 432                 /usr/local/bin:/usr/local/sbin:\
 433                 /usr/bin:/usr/sbin:/bin:/sbin
 434         initgroups = true
 435         umask = 002
 436         return_fail_output = true
 437         log_output = true
 438
 439 ## A special dummy transport for use during address verification.
 440 dummy:
 441         driver = appendfile
 442         file = /dev/null
 443
 444 DIVERT(null)
 445 ###--------------------------------------------------------------------------
 446 ### Retry configuration.
 447
 448 SECTION(retry, default)m4_dnl
 449 ## Default.
 450 *                                       * \
 451         F,2h,15m; G,16h,2h,1.5; F,4d,6h
 452
 453 DIVERT(null)
 454 ###----- That's all, folks --------------------------------------------------