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