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\
  64               ${if def:sender_helo_name \
  65                    { (helo=$sender_helo_name)}}\n\t} \
  66              {${if def:sender_ident \
  67                    {from ${quote_local_part:$sender_ident} }}}}\
  68         by $primary_hostname \
  69         (Exim $version_number)\
  70         ${if def:tls_cipher {\n\t} { }}\
  71         ${if def:received_protocol \
  72              {with $received_protocol \
  73               ${if def:tls_cipher {(cipher=$tls_cipher)}}}}\n\t\
  74         ${if def:sender_address \
  75              {(envelope-from $sender_address\
  76               ${if def:authenticated_id \
  77                    {; auth=$authenticated_id}})\n\t}}\
  78         id $message_exim_id\
  79         ${if def:received_for {\n\tfor $received_for}}
  80
  81 SECTION(global, smtp)m4_dnl
  82 smtp_return_error_details = true
  83 accept_8bitmime = true
  84
  85 SECTION(global, process)m4_dnl
  86 extract_addresses_remove_arguments = false
  87 headers_charset = utf-8
  88 qualify_domain = CONF_master_domain
  89
  90 SECTION(global, bounce)m4_dnl
  91 delay_warning = 1h : 24h : 2d
  92
  93 DIVERT(null)
  94 ###--------------------------------------------------------------------------
  95 ### Access control lists.
  96
  97 SECTION(global, acl-after)
  98 SECTION(global, acl)m4_dnl
  99 acl_smtp_helo = helo
 100 SECTION(acl, misc)m4_dnl
 101 helo:
 102         ## Check that the caller's claimed identity is actually plausible.
 103         ## This seems like it's a fairly effective filter on spamminess, but
 104         ## it's too blunt a tool.  Rather than reject, add a warning header.
 105         ## Only we can't do this the easy way, so save it up for use in MAIL.
 106         ## Also, we're liable to get a subsequent HELO (e.g., after STARTTLS)
 107         ## and we should only care about the most recent one.
 108         warn     set acl_c_helo_warning = false
 109                 !condition = \
 110                         ${if exists {CONF_sysconf_dir/helo.conf} \
 111                              {${lookup {$sender_helo_name} \
 112                                        partial0-lsearch \
 113                                        {CONF_sysconf_dir/helo.conf} \
 114                                        {${if match_ip \
 115                                              {$sender_host_address} \
 116                                              {$value}}}}}}
 117                 !verify = helo
 118                  set acl_c_helo_warning = true
 119
 120         accept
 121
 122 SECTION(global, acl)m4_dnl
 123 acl_not_smtp_start = not_smtp_start
 124 SECTION(acl, misc)m4_dnl
 125 not_smtp_start:
 126         ## Record the user's name.
 127         warn     set acl_c_user = $sender_ident
 128
 129         ## Done.
 130         accept
 131
 132 SECTION(global, acl)m4_dnl
 133 acl_smtp_mail = mail
 134 SECTION(acl, mail)m4_dnl
 135 mail:
 136
 137         ## If we stashed a warning header about HELO from earlier, we should
 138         ## add it now.
 139         warn     condition = $acl_c_helo_warning
 140                  add_header = :after_received:X-Distorted-Warning: \
 141                         BADHELO \
 142                         Client's HELO doesn't match its IP address.\n\t\
 143                         HELO name=$sender_helo_name, \
 144                         address=$sender_host_address
 145
 146         ## Always allow the empty sender, so that we can receive bounces.
 147         accept   senders = :
 148
 149         ## Ensure that the sender is routable.  This is important to prevent
 150         ## undeliverable bounces.
 151         require  message = Invalid sender; \
 152                         ($sender_verify_failure; $acl_verify_message)
 153                  verify = sender
 154
 155         ## If this is directly from a client then hack on it for a while.
 156         warn     condition = ${if eq{$acl_c_mode}{submission}}
 157                  control = submission
 158
 159         ## Insist that a local client connect through TLS.
 160         deny     message = Hosts within CONF_master_domain must use TLS
 161                 !condition = ${if eq{$acl_c_mode}{submission}}
 162                  hosts = +allnets
 163                 !encrypted = *
 164
 165         ## Check that a submitted message's sender address is allowable.
 166         require  acl = mail_check_auth
 167
 168 SECTION(acl, mail-tail)m4_dnl
 169         ## And we're done.
 170         accept
 171
 172 SECTION(global, acl)m4_dnl
 173 acl_smtp_connect = connect
 174 SECTION(acl, connect)m4_dnl
 175 connect:
 176 SECTION(acl, connect-tail)m4_dnl
 177         ## Configure variables according to the submission mode.
 178         warn     acl = check_submission
 179
 180         ## Done.
 181         accept
 182
 183 check_submission:
 184         ## See whether this message needs hacking on.
 185         accept  !hosts = +localnet
 186                 !condition = ${if ={$received_port}{CONF_submission_port}}
 187                  set acl_c_mode = relay
 188
 189         ## Remember to apply submission controls.
 190         warn     set acl_c_mode = submission
 191
 192         ## Done.
 193         accept
 194
 195 SECTION(global, acl)m4_dnl
 196 acl_smtp_rcpt = rcpt
 197 SECTION(acl, rcpt)m4_dnl
 198 rcpt:
 199
 200         ## Reject if the client isn't allowed to relay and the recipient
 201         ## isn't in one of our known domains.
 202         deny     message = Relaying not permitted
 203                 !hosts = CONF_relay_clients
 204                 !authenticated = *
 205                 !domains = +known
 206
 207         ## Ensure that the recipient is routable.
 208         require  message = Invalid recipient \
 209                         ($recipient_verify_failure; $acl_verify_message)
 210                  verify = recipient
 211
 212 SECTION(acl, rcpt-tail)m4_dnl
 213         ## Everything checks out OK: let this one go through.
 214         accept
 215
 216 SECTION(global, acl)m4_dnl
 217 acl_smtp_data = data
 218 SECTION(acl, data)m4_dnl
 219 data:
 220
 221 SECTION(acl, data-tail)m4_dnl
 222         accept
 223
 224 SECTION(global, acl)m4_dnl
 225 acl_smtp_expn = expn_vrfy
 226 acl_smtp_vrfy = expn_vrfy
 227 SECTION(acl)m4_dnl
 228 expn_vrfy:
 229         accept   hosts = +trusted
 230         deny     message = Suck it and see
 231
 232 DIVERT(null)
 233 ###--------------------------------------------------------------------------
 234 ### Verification of sender address.
 235
 236 SECTION(acl, misc)m4_dnl
 237 mail_check_auth:
 238
 239         ## If this isn't a submission then it doesn't need checking.
 240         accept   condition = ${if !eq{$acl_c_mode}{submission}}
 241
 242         ## If the caller hasn't formally authenticated, but this is a
 243         ## loopback connection, then we can trust identd to tell us the right
 244         ## answer.  So we should stash the right name somewhere consistent.
 245         warn     set acl_c_user = $authenticated_id
 246                  hosts = +localnet
 247                 !authenticated = *
 248                  set acl_c_user = $sender_ident
 249
 250         ## User must be authenticated.
 251         deny     message = Sender not authenticated
 252                 !hosts = +localnet
 253                 !authenticated = *
 254
 255         ## Make sure that the local part is one that the authenticated sender
 256         ## is allowed to claim.
 257         deny     message = Sender address forbidden to calling user
 258                 !condition = ${LOOKUP_DOMAIN($sender_address_domain,
 259                                {${if and {{match_local_part \
 260                                             {$acl_c_user} \
 261                                             {+dom_users}} \
 262                                           {match_local_part \
 263                                             {$sender_address_local_part} \
 264                                             {+dom_locals}}}}},
 265                                {${if and {{match_local_part \
 266                                             {$sender_address_local_part} \
 267                                             {+user_extaddr}} \
 268                                           {or {{eq {$sender_address_domain} \
 269                                                    {}} \
 270                                                {match_domain \
 271                                                  {$sender_address_domain} \
 272                                                  {+public}}}}}}})}
 273
 274         ## All done.
 275         accept
 276
 277 DIVERT(null)
 278 ###--------------------------------------------------------------------------
 279 ### Common options for forwarding routers.
 280
 281 ## We're pretty permissive here.
 282 m4_define(<:FILTER_BASE:>,
 283         <:driver = redirect
 284         modemask = 002
 285         check_owner = false
 286         check_group = false
 287         allow_filter = true
 288         allow_defer = true
 289         allow_fail = true
 290         forbid_blackhole = false
 291         check_ancestor = true:>)
 292
 293 ## Common options for forwarding routers at verification time.
 294 m4_define(<:FILTER_VERIFY:>,
 295         <:verify_only = true
 296         user = CONF_filter_user
 297         forbid_filter_dlfunc = true
 298         forbid_filter_logwrite = true
 299         forbid_filter_perl = true
 300         forbid_filter_readsocket = true
 301         forbid_filter_run = true
 302         file_transport = dummy
 303         directory_transport = dummy
 304         pipe_transport = dummy
 305         reply_transport = dummy:>)
 306
 307 ## Transports for redirection filters.
 308 m4_define(<:FILTER_TRANSPORTS:>,
 309         <:file_transport = mailbox
 310         directory_transport = maildir
 311         pipe_transport = pipe
 312         reply_transport = reply:>)
 313
 314 m4_define(<:FILTER_ROUTER:>,
 315 <:$1_vrf:
 316         $2
 317         FILTER_VERIFY<::>$3
 318 $1:
 319         $2
 320         verify = no
 321         FILTER_TRANSPORTS<::>$4:>)
 322
 323 DIVERT(null)
 324 ###--------------------------------------------------------------------------
 325 ### Some standard transports.
 326
 327 m4_define(<:USER_DELIVERY:>,
 328         <:delivery_date_add = true
 329         envelope_to_add = true
 330         return_path_add = true:>)
 331
 332 SECTION(transports)m4_dnl
 333 ## A standard transport for remote delivery.  Try to do TLS, and don't worry
 334 ## too much if it's not very secure: the alternative is sending in plaintext
 335 ## anyway.
 336 smtp:
 337         driver = smtp
 338         tls_require_ciphers = CONF_acceptable_ciphers
 339         tls_dh_min_bits = 1020
 340         tls_tempfail_tryclear = true
 341
 342 ## Transport to a local SMTP server; use TLS and perform client
 343 ## authentication.
 344 smtp_local:
 345         driver = smtp
 346         hosts_require_tls = *
 347         tls_certificate = CONF_sysconf_dir/client.cert
 348         tls_privatekey = CONF_sysconf_dir/client.key
 349         tls_verify_certificates = CONF_ca_dir/ca.cert
 350         tls_require_ciphers = CONF_good_ciphers
 351         tls_dh_min_bits = 2046
 352         tls_tempfail_tryclear = false
 353         authenticated_sender = ${if def:authenticated_id \
 354                                     {$authenticated_id@CONF_master_domain} \
 355                                     fail}
 356
 357 ## A standard transport for local delivery.
 358 deliver:
 359         driver = appendfile
 360         file = /var/mail/$local_part
 361         group = mail
 362         mode = 0600
 363         mode_fail_narrower = false
 364         USER_DELIVERY
 365
 366 ## Transports for user filters.
 367 mailbox:
 368         driver = appendfile
 369         initgroups = true
 370         USER_DELIVERY
 371
 372 maildir:
 373         driver = appendfile
 374         maildir_format = true
 375         initgroups = true
 376         USER_DELIVERY
 377
 378 pipe:
 379         driver = pipe
 380         path = ${if and {{def:home} {exists{$home/bin}}} {$home/bin:} {}}\
 381                 /usr/local/bin:/usr/local/sbin:\
 382                 /usr/bin:/usr/sbin:/bin:/sbin
 383         initgroups = true
 384         umask = 002
 385         return_fail_output = true
 386         log_output = true
 387
 388 ## A special dummy transport for use during address verification.
 389 dummy:
 390         driver = appendfile
 391         file = /dev/null
 392
 393 DIVERT(null)
 394 ###--------------------------------------------------------------------------
 395 ### Retry configuration.
 396
 397 SECTION(retry, default)m4_dnl
 398 ## Default.
 399 *                                       * \
 400         F,2h,15m; G,16h,2h,1.5; F,4d,6h
 401
 402 DIVERT(null)
 403 ###----- That's all, folks --------------------------------------------------