/* $NetBSD: smtp.c,v 1.10 2017/02/14 01:16:48 christos Exp $ */
/*++
/* NAME
/* smtp 8
/* SUMMARY
/* Postfix SMTP+LMTP client
/* SYNOPSIS
/* \fBsmtp\fR [generic Postfix daemon options]
/* DESCRIPTION
/* The Postfix SMTP+LMTP client implements the SMTP and LMTP mail
/* delivery protocols. It processes message delivery requests from
/* the queue manager. Each request specifies a queue file, a sender
/* address, a domain or host to deliver to, and recipient information.
/* This program expects to be run from the \fBmaster\fR(8) process
/* manager.
/*
/* The SMTP+LMTP client updates the queue file and marks recipients
/* as finished, or it informs the queue manager that delivery should
/* be tried again at a later time. Delivery status reports are sent
/* to the \fBbounce\fR(8), \fBdefer\fR(8) or \fBtrace\fR(8) daemon as
/* appropriate.
/*
/* The SMTP+LMTP client looks up a list of mail exchanger addresses for
/* the destination host, sorts the list by preference, and connects
/* to each listed address until it finds a server that responds.
/*
/* When a server is not reachable, or when mail delivery fails due
/* to a recoverable error condition, the SMTP+LMTP client will try to
/* deliver the mail to an alternate host.
/*
/* After a successful mail transaction, a connection may be saved
/* to the \fBscache\fR(8) connection cache server, so that it
/* may be used by any SMTP+LMTP client for a subsequent transaction.
/*
/* By default, connection caching is enabled temporarily for
/* destinations that have a high volume of mail in the active
/* queue. Connection caching can be enabled permanently for
/* specific destinations.
/* SMTP DESTINATION SYNTAX
/* .ad
/* .fi
/* SMTP destinations have the following form:
/* .IP \fIdomainname\fR
/* .IP \fIdomainname\fR:\fIport\fR
/* Look up the mail exchangers for the specified domain, and
/* connect to the specified port (default: \fBsmtp\fR).
/* .IP [\fIhostname\fR]
/* .IP [\fIhostname\fR]:\fIport\fR
/* Look up the address(es) of the specified host, and connect to
/* the specified port (default: \fBsmtp\fR).
/* .IP [\fIaddress\fR]
/* .IP [\fIaddress\fR]:\fIport\fR
/* Connect to the host at the specified address, and connect
/* to the specified port (default: \fBsmtp\fR). An IPv6 address
/* must be formatted as [\fBipv6\fR:\fIaddress\fR].
/* LMTP DESTINATION SYNTAX
/* .ad
/* .fi
/* LMTP destinations have the following form:
/* .IP \fBunix\fR:\fIpathname\fR
/* Connect to the local UNIX-domain server that is bound to the specified
/* \fIpathname\fR. If the process runs chrooted, an absolute pathname
/* is interpreted relative to the Postfix queue directory.
/* .IP \fBinet\fR:\fIhostname\fR
/* .IP \fBinet\fR:\fIhostname\fR:\fIport\fR
/* .IP \fBinet\fR:[\fIaddress\fR]
/* .IP \fBinet\fR:[\fIaddress\fR]:\fIport\fR
/* Connect to the specified TCP port on the specified local or
/* remote host. If no port is specified, connect to the port defined as
/* \fBlmtp\fR in \fBservices\fR(4).
/* If no such service is found, the \fBlmtp_tcp_port\fR configuration
/* parameter (default value of 24) will be used.
/* An IPv6 address must be formatted as [\fBipv6\fR:\fIaddress\fR].
/* .PP
/* SECURITY
/* .ad
/* .fi
/* The SMTP+LMTP client is moderately security-sensitive. It
/* talks to SMTP or LMTP servers and to DNS servers on the
/* network. The SMTP+LMTP client can be run chrooted at fixed
/* low privilege.
/* STANDARDS
/* RFC 821 (SMTP protocol)
/* RFC 822 (ARPA Internet Text Messages)
/* RFC 1651 (SMTP service extensions)
/* RFC 1652 (8bit-MIME transport)
/* RFC 1870 (Message Size Declaration)
/* RFC 2033 (LMTP protocol)
/* RFC 2034 (SMTP Enhanced Error Codes)
/* RFC 2045 (MIME: Format of Internet Message Bodies)
/* RFC 2046 (MIME: Media Types)
/* RFC 2554 (AUTH command)
/* RFC 2821 (SMTP protocol)
/* RFC 2920 (SMTP Pipelining)
/* RFC 3207 (STARTTLS command)
/* RFC 3461 (SMTP DSN Extension)
/* RFC 3463 (Enhanced Status Codes)
/* RFC 4954 (AUTH command)
/* RFC 5321 (SMTP protocol)
/* RFC 6531 (Internationalized SMTP)
/* RFC 6533 (Internationalized Delivery Status Notifications)
/* RFC 7672 (SMTP security via opportunistic DANE TLS)
/* DIAGNOSTICS
/* Problems and transactions are logged to \fBsyslogd\fR(8).
/* Corrupted message files are marked so that the queue manager can
/* move them to the \fBcorrupt\fR queue for further inspection.
/*
/* Depending on the setting of the \fBnotify_classes\fR parameter,
/* the postmaster is notified of bounces, protocol problems, and of
/* other trouble.
/* BUGS
/* SMTP and LMTP connection caching does not work with TLS. The necessary
/* support for TLS object passivation and re-activation does not
/* exist without closing the session, which defeats the purpose.
/*
/* SMTP and LMTP connection caching assumes that SASL credentials
/* are valid for all destinations that map onto the same IP
/* address and TCP port.
/* CONFIGURATION PARAMETERS
/* .ad
/* .fi
/* Before Postfix version 2.3, the LMTP client is a separate
/* program that implements only a subset of the functionality
/* available with SMTP: there is no support for TLS, and
/* connections are cached in-process, making it ineffective
/* when the client is used for multiple domains.
/*
/* Most smtp_\fIxxx\fR configuration parameters have an
/* lmtp_\fIxxx\fR "mirror" parameter for the equivalent LMTP
/* feature. This document describes only those LMTP-related
/* parameters that aren't simply "mirror" parameters.
/*
/* Changes to \fBmain.cf\fR are picked up automatically, as \fBsmtp\fR(8)
/* processes run for only a limited amount of time. Use the command
/* "\fBpostfix reload\fR" to speed up a change.
/*
/* The text below provides only a parameter summary. See
/* \fBpostconf\fR(5) for more details including examples.
/* COMPATIBILITY CONTROLS
/* .ad
/* .fi
/* .IP "\fBignore_mx_lookup_error (no)\fR"
/* Ignore DNS MX lookups that produce no response.
/* .IP "\fBsmtp_always_send_ehlo (yes)\fR"
/* Always send EHLO at the start of an SMTP session.
/* .IP "\fBsmtp_never_send_ehlo (no)\fR"
/* Never send EHLO at the start of an SMTP session.
/* .IP "\fBsmtp_defer_if_no_mx_address_found (no)\fR"
/* Defer mail delivery when no MX record resolves to an IP address.
/* .IP "\fBsmtp_line_length_limit (998)\fR"
/* The maximal length of message header and body lines that Postfix
/* will send via SMTP.
/* .IP "\fBsmtp_pix_workaround_delay_time (10s)\fR"
/* How long the Postfix SMTP client pauses before sending
/* ".<CR><LF>" in order to work around the PIX firewall
/* "<CR><LF>.<CR><LF>" bug.
/* .IP "\fBsmtp_pix_workaround_threshold_time (500s)\fR"
/* How long a message must be queued before the Postfix SMTP client
/* turns on the PIX firewall "<CR><LF>.<CR><LF>"
/* bug workaround for delivery through firewalls with "smtp fixup"
/* mode turned on.
/* .IP "\fBsmtp_pix_workarounds (disable_esmtp, delay_dotcrlf)\fR"
/* A list that specifies zero or more workarounds for CISCO PIX
/* firewall bugs.
/* .IP "\fBsmtp_pix_workaround_maps (empty)\fR"
/* Lookup tables, indexed by the remote SMTP server address, with
/* per-destination workarounds for CISCO PIX firewall bugs.
/* .IP "\fBsmtp_quote_rfc821_envelope (yes)\fR"
/* Quote addresses in Postfix SMTP client MAIL FROM and RCPT TO commands
/* as required
/* by RFC 5321.
/* .IP "\fBsmtp_reply_filter (empty)\fR"
/* A mechanism to transform replies from remote SMTP servers one
/* line at a time.
/* .IP "\fBsmtp_skip_5xx_greeting (yes)\fR"
/* Skip remote SMTP servers that greet with a 5XX status code.
/* .IP "\fBsmtp_skip_quit_response (yes)\fR"
/* Do not wait for the response to the SMTP QUIT command.
/* .PP
/* Available in Postfix version 2.0 and earlier:
/* .IP "\fBsmtp_skip_4xx_greeting (yes)\fR"
/* Skip SMTP servers that greet with a 4XX status code (go away, try
/* again later).
/* .PP
/* Available in Postfix version 2.2 and later:
/* .IP "\fBsmtp_discard_ehlo_keyword_address_maps (empty)\fR"
/* Lookup tables, indexed by the remote SMTP server address, with
/* case insensitive lists of EHLO keywords (pipelining, starttls, auth,
/* etc.) that the Postfix SMTP client will ignore in the EHLO response from a
/* remote SMTP server.
/* .IP "\fBsmtp_discard_ehlo_keywords (empty)\fR"
/* A case insensitive list of EHLO keywords (pipelining, starttls,
/* auth, etc.) that the Postfix SMTP client will ignore in the EHLO
/* response from a remote SMTP server.
/* .IP "\fBsmtp_generic_maps (empty)\fR"
/* Optional lookup tables that perform address rewriting in the
/* Postfix SMTP client, typically to transform a locally valid address into
/* a globally valid address when sending mail across the Internet.
/* .PP
/* Available in Postfix version 2.2.9 and later:
/* .IP "\fBsmtp_cname_overrides_servername (version dependent)\fR"
/* When the remote SMTP servername is a DNS CNAME, replace the
/* servername with the result from CNAME expansion for the purpose of
/* logging, SASL password lookup, TLS
/* policy decisions, or TLS certificate verification.
/* .PP
/* Available in Postfix version 2.3 and later:
/* .IP "\fBlmtp_discard_lhlo_keyword_address_maps (empty)\fR"
/* Lookup tables, indexed by the remote LMTP server address, with
/* case insensitive lists of LHLO keywords (pipelining, starttls,
/* auth, etc.) that the Postfix LMTP client will ignore in the LHLO
/* response
/* from a remote LMTP server.
/* .IP "\fBlmtp_discard_lhlo_keywords (empty)\fR"
/* A case insensitive list of LHLO keywords (pipelining, starttls,
/* auth, etc.) that the Postfix LMTP client will ignore in the LHLO
/* response
/* from a remote LMTP server.
/* .PP
/* Available in Postfix version 2.4.4 and later:
/* .IP "\fBsend_cyrus_sasl_authzid (no)\fR"
/* When authenticating to a remote SMTP or LMTP server with the
/* default setting "no", send no SASL authoriZation ID (authzid); send
/* only the SASL authentiCation ID (authcid) plus the authcid's password.
/* .PP
/* Available in Postfix version 2.5 and later:
/* .IP "\fBsmtp_header_checks (empty)\fR"
/* Restricted \fBheader_checks\fR(5) tables for the Postfix SMTP client.
/* .IP "\fBsmtp_mime_header_checks (empty)\fR"
/* Restricted \fBmime_header_checks\fR(5) tables for the Postfix SMTP
/* client.
/* .IP "\fBsmtp_nested_header_checks (empty)\fR"
/* Restricted \fBnested_header_checks\fR(5) tables for the Postfix SMTP
/* client.
/* .IP "\fBsmtp_body_checks (empty)\fR"
/* Restricted \fBbody_checks\fR(5) tables for the Postfix SMTP client.
/* .PP
/* Available in Postfix version 2.6 and later:
/* .IP "\fBtcp_windowsize (0)\fR"
/* An optional workaround for routers that break TCP window scaling.
/* .PP
/* Available in Postfix version 2.8 and later:
/* .IP "\fBsmtp_dns_resolver_options (empty)\fR"
/* DNS Resolver options for the Postfix SMTP client.
/* .PP
/* Available in Postfix version 2.9 and later:
/* .IP "\fBsmtp_per_record_deadline (no)\fR"
/* Change the behavior of the smtp_*_timeout time limits, from a
/* time limit per read or write system call, to a time limit to send
/* or receive a complete record (an SMTP command line, SMTP response
/* line, SMTP message content line, or TLS protocol message).
/* .IP "\fBsmtp_send_dummy_mail_auth (no)\fR"
/* Whether or not to append the "AUTH=<>" option to the MAIL
/* FROM command in SASL-authenticated SMTP sessions.
/* .PP
/* Available in Postfix version 2.11 and later:
/* .IP "\fBsmtp_dns_support_level (empty)\fR"
/* Level of DNS support in the Postfix SMTP client.
/* .PP
/* Available in Postfix version 3.0 and later:
/* .IP "\fBsmtp_delivery_status_filter ($default_delivery_status_filter)\fR"
/* Optional filter for the \fBsmtp\fR(8) delivery agent to change the
/* delivery status code or explanatory text of successful or unsuccessful
/* deliveries.
/* .IP "\fBsmtp_dns_reply_filter (empty)\fR"
/* Optional filter for Postfix SMTP client DNS lookup results.
/* MIME PROCESSING CONTROLS
/* .ad
/* .fi
/* Available in Postfix version 2.0 and later:
/* .IP "\fBdisable_mime_output_conversion (no)\fR"
/* Disable the conversion of 8BITMIME format to 7BIT format.
/* .IP "\fBmime_boundary_length_limit (2048)\fR"
/* The maximal length of MIME multipart boundary strings.
/* .IP "\fBmime_nesting_limit (100)\fR"
/* The maximal recursion level that the MIME processor will handle.
/* EXTERNAL CONTENT INSPECTION CONTROLS
/* .ad
/* .fi
/* Available in Postfix version 2.1 and later:
/* .IP "\fBsmtp_send_xforward_command (no)\fR"
/* Send the non-standard XFORWARD command when the Postfix SMTP server
/* EHLO response announces XFORWARD support.
/* SASL AUTHENTICATION CONTROLS
/* .ad
/* .fi
/* .IP "\fBsmtp_sasl_auth_enable (no)\fR"
/* Enable SASL authentication in the Postfix SMTP client.
/* .IP "\fBsmtp_sasl_password_maps (empty)\fR"
/* Optional Postfix SMTP client lookup tables with one username:password
/* entry per sender, remote hostname or next-hop domain.
/* .IP "\fBsmtp_sasl_security_options (noplaintext, noanonymous)\fR"
/* Postfix SMTP client SASL security options; as of Postfix 2.3
/* the list of available
/* features depends on the SASL client implementation that is selected
/* with \fBsmtp_sasl_type\fR.
/* .PP
/* Available in Postfix version 2.2 and later:
/* .IP "\fBsmtp_sasl_mechanism_filter (empty)\fR"
/* If non-empty, a Postfix SMTP client filter for the remote SMTP
/* server's list of offered SASL mechanisms.
/* .PP
/* Available in Postfix version 2.3 and later:
/* .IP "\fBsmtp_sender_dependent_authentication (no)\fR"
/* Enable sender-dependent authentication in the Postfix SMTP client; this is
/* available only with SASL authentication, and disables SMTP connection
/* caching to ensure that mail from different senders will use the
/* appropriate credentials.
/* .IP "\fBsmtp_sasl_path (empty)\fR"
/* Implementation-specific information that the Postfix SMTP client
/* passes through to
/* the SASL plug-in implementation that is selected with
/* \fBsmtp_sasl_type\fR.
/* .IP "\fBsmtp_sasl_type (cyrus)\fR"
/* The SASL plug-in type that the Postfix SMTP client should use
/* for authentication.
/* .PP
/* Available in Postfix version 2.5 and later:
/* .IP "\fBsmtp_sasl_auth_cache_name (empty)\fR"
/* An optional table to prevent repeated SASL authentication
/* failures with the same remote SMTP server hostname, username and
/* password.
/* .IP "\fBsmtp_sasl_auth_cache_time (90d)\fR"
/* The maximal age of an smtp_sasl_auth_cache_name entry before it
/* is removed.
/* .IP "\fBsmtp_sasl_auth_soft_bounce (yes)\fR"
/* When a remote SMTP server rejects a SASL authentication request
/* with a 535 reply code, defer mail delivery instead of returning
/* mail as undeliverable.
/* .PP
/* Available in Postfix version 2.9 and later:
/* .IP "\fBsmtp_send_dummy_mail_auth (no)\fR"
/* Whether or not to append the "AUTH=<>" option to the MAIL
/* FROM command in SASL-authenticated SMTP sessions.
/* STARTTLS SUPPORT CONTROLS
/* .ad
/* .fi
/* Detailed information about STARTTLS configuration may be found
/* in the TLS_README document.
/* .IP "\fBsmtp_tls_security_level (empty)\fR"
/* The default SMTP TLS security level for the Postfix SMTP client;
/* when a non-empty value is specified, this overrides the obsolete
/* parameters smtp_use_tls, smtp_enforce_tls, and smtp_tls_enforce_peername.
/* .IP "\fBsmtp_sasl_tls_security_options ($smtp_sasl_security_options)\fR"
/* The SASL authentication security options that the Postfix SMTP
/* client uses for TLS encrypted SMTP sessions.
/* .IP "\fBsmtp_starttls_timeout (300s)\fR"
/* Time limit for Postfix SMTP client write and read operations
/* during TLS startup and shutdown handshake procedures.
/* .IP "\fBsmtp_tls_CAfile (empty)\fR"
/* A file containing CA certificates of root CAs trusted to sign
/* either remote SMTP server certificates or intermediate CA certificates.
/* .IP "\fBsmtp_tls_CApath (empty)\fR"
/* Directory with PEM format Certification Authority certificates
/* that the Postfix SMTP client uses to verify a remote SMTP server
/* certificate.
/* .IP "\fBsmtp_tls_cert_file (empty)\fR"
/* File with the Postfix SMTP client RSA certificate in PEM format.
/* .IP "\fBsmtp_tls_mandatory_ciphers (medium)\fR"
/* The minimum TLS cipher grade that the Postfix SMTP client will
/* use with
/* mandatory TLS encryption.
/* .IP "\fBsmtp_tls_exclude_ciphers (empty)\fR"
/* List of ciphers or cipher types to exclude from the Postfix
/* SMTP client cipher
/* list at all TLS security levels.
/* .IP "\fBsmtp_tls_mandatory_exclude_ciphers (empty)\fR"
/* Additional list of ciphers or cipher types to exclude from the
/* Postfix SMTP client cipher list at mandatory TLS security levels.
/* .IP "\fBsmtp_tls_dcert_file (empty)\fR"
/* File with the Postfix SMTP client DSA certificate in PEM format.
/* .IP "\fBsmtp_tls_dkey_file ($smtp_tls_dcert_file)\fR"
/* File with the Postfix SMTP client DSA private key in PEM format.
/* .IP "\fBsmtp_tls_key_file ($smtp_tls_cert_file)\fR"
/* File with the Postfix SMTP client RSA private key in PEM format.
/* .IP "\fBsmtp_tls_loglevel (0)\fR"
/* Enable additional Postfix SMTP client logging of TLS activity.
/* .IP "\fBsmtp_tls_note_starttls_offer (no)\fR"
/* Log the hostname of a remote SMTP server that offers STARTTLS,
/* when TLS is not already enabled for that server.
/* .IP "\fBsmtp_tls_policy_maps (empty)\fR"
/* Optional lookup tables with the Postfix SMTP client TLS security
/* policy by next-hop destination; when a non-empty value is specified,
/* this overrides the obsolete smtp_tls_per_site parameter.
/* .IP "\fBsmtp_tls_mandatory_protocols (!SSLv2, !SSLv3)\fR"
/* List of SSL/TLS protocols that the Postfix SMTP client will use with
/* mandatory TLS encryption.
/* .IP "\fBsmtp_tls_scert_verifydepth (9)\fR"
/* The verification depth for remote SMTP server certificates.
/* .IP "\fBsmtp_tls_secure_cert_match (nexthop, dot-nexthop)\fR"
/* How the Postfix SMTP client verifies the server certificate
/* peername for the "secure" TLS security level.
/* .IP "\fBsmtp_tls_session_cache_database (empty)\fR"
/* Name of the file containing the optional Postfix SMTP client
/* TLS session cache.
/* .IP "\fBsmtp_tls_session_cache_timeout (3600s)\fR"
/* The expiration time of Postfix SMTP client TLS session cache
/* information.
/* .IP "\fBsmtp_tls_verify_cert_match (hostname)\fR"
/* How the Postfix SMTP client verifies the server certificate
/* peername for the
/* "verify" TLS security level.
/* .IP "\fBtls_daemon_random_bytes (32)\fR"
/* The number of pseudo-random bytes that an \fBsmtp\fR(8) or \fBsmtpd\fR(8)
/* process requests from the \fBtlsmgr\fR(8) server in order to seed its
/* internal pseudo random number generator (PRNG).
/* .IP "\fBtls_high_cipherlist (see 'postconf -d' output)\fR"
/* The OpenSSL cipherlist for "high" grade ciphers.
/* .IP "\fBtls_medium_cipherlist (see 'postconf -d' output)\fR"
/* The OpenSSL cipherlist for "medium" or higher grade ciphers.
/* .IP "\fBtls_low_cipherlist (see 'postconf -d' output)\fR"
/* The OpenSSL cipherlist for "low" or higher grade ciphers.
/* .IP "\fBtls_export_cipherlist (see 'postconf -d' output)\fR"
/* The OpenSSL cipherlist for "export" or higher grade ciphers.
/* .IP "\fBtls_null_cipherlist (eNULL:!aNULL)\fR"
/* The OpenSSL cipherlist for "NULL" grade ciphers that provide
/* authentication without encryption.
/* .PP
/* Available in Postfix version 2.4 and later:
/* .IP "\fBsmtp_sasl_tls_verified_security_options ($smtp_sasl_tls_security_options)\fR"
/* The SASL authentication security options that the Postfix SMTP
/* client uses for TLS encrypted SMTP sessions with a verified server
/* certificate.
/* .PP
/* Available in Postfix version 2.5 and later:
/* .IP "\fBsmtp_tls_fingerprint_cert_match (empty)\fR"
/* List of acceptable remote SMTP server certificate fingerprints for
/* the "fingerprint" TLS security level (\fBsmtp_tls_security_level\fR =
/* fingerprint).
/* .IP "\fBsmtp_tls_fingerprint_digest (md5)\fR"
/* The message digest algorithm used to construct remote SMTP server
/* certificate fingerprints.
/* .PP
/* Available in Postfix version 2.6 and later:
/* .IP "\fBsmtp_tls_protocols (!SSLv2, !SSLv3)\fR"
/* List of TLS protocols that the Postfix SMTP client will exclude or
/* include with opportunistic TLS encryption.
/* .IP "\fBsmtp_tls_ciphers (medium)\fR"
/* The minimum TLS cipher grade that the Postfix SMTP client
/* will use with opportunistic TLS encryption.
/* .IP "\fBsmtp_tls_eccert_file (empty)\fR"
/* File with the Postfix SMTP client ECDSA certificate in PEM format.
/* .IP "\fBsmtp_tls_eckey_file ($smtp_tls_eccert_file)\fR"
/* File with the Postfix SMTP client ECDSA private key in PEM format.
/* .PP
/* Available in Postfix version 2.7 and later:
/* .IP "\fBsmtp_tls_block_early_mail_reply (no)\fR"
/* Try to detect a mail hijacking attack based on a TLS protocol
/* vulnerability (CVE-2009-3555), where an attacker prepends malicious
/* HELO, MAIL, RCPT, DATA commands to a Postfix SMTP client TLS session.
/* .PP
/* Available in Postfix version 2.8 and later:
/* .IP "\fBtls_disable_workarounds (see 'postconf -d' output)\fR"
/* List or bit-mask of OpenSSL bug work-arounds to disable.
/* .PP
/* Available in Postfix version 2.11 and later:
/* .IP "\fBsmtp_tls_trust_anchor_file (empty)\fR"
/* Zero or more PEM-format files with trust-anchor certificates
/* and/or public keys.
/* .IP "\fBsmtp_tls_force_insecure_host_tlsa_lookup (no)\fR"
/* Lookup the associated DANE TLSA RRset even when a hostname is
/* not an alias and its address records lie in an unsigned zone.
/* .IP "\fBtls_dane_trust_anchor_digest_enable (yes)\fR"
/* RFC 6698 trust-anchor digest support in the Postfix TLS library.
/* .IP "\fBtlsmgr_service_name (tlsmgr)\fR"
/* The name of the \fBtlsmgr\fR(8) service entry in master.cf.
/* .PP
/* Available in Postfix version 3.0 and later:
/* .IP "\fBsmtp_tls_wrappermode (no)\fR"
/* Request that the Postfix SMTP client connects using the
/* legacy SMTPS protocol instead of using the STARTTLS command.
/* .PP
/* Available in Postfix version 3.1 and later:
/* .IP "\fBsmtp_tls_dane_insecure_mx_policy (dane)\fR"
/* The TLS policy for MX hosts with "secure" TLSA records when the
/* nexthop destination security level is \fBdane\fR, but the MX
/* record was found via an "insecure" MX lookup.
/* OBSOLETE STARTTLS CONTROLS
/* .ad
/* .fi
/* The following configuration parameters exist for compatibility
/* with Postfix versions before 2.3. Support for these will
/* be removed in a future release.
/* .IP "\fBsmtp_use_tls (no)\fR"
/* Opportunistic mode: use TLS when a remote SMTP server announces
/* STARTTLS support, otherwise send the mail in the clear.
/* .IP "\fBsmtp_enforce_tls (no)\fR"
/* Enforcement mode: require that remote SMTP servers use TLS
/* encryption, and never send mail in the clear.
/* .IP "\fBsmtp_tls_enforce_peername (yes)\fR"
/* With mandatory TLS encryption, require that the remote SMTP
/* server hostname matches the information in the remote SMTP server
/* certificate.
/* .IP "\fBsmtp_tls_per_site (empty)\fR"
/* Optional lookup tables with the Postfix SMTP client TLS usage
/* policy by next-hop destination and by remote SMTP server hostname.
/* .IP "\fBsmtp_tls_cipherlist (empty)\fR"
/* Obsolete Postfix < 2.3 control for the Postfix SMTP client TLS
/* cipher list.
/* RESOURCE AND RATE CONTROLS
/* .ad
/* .fi
/* .IP "\fBsmtp_destination_concurrency_limit ($default_destination_concurrency_limit)\fR"
/* The maximal number of parallel deliveries to the same destination
/* via the smtp message delivery transport.
/* .IP "\fBsmtp_destination_recipient_limit ($default_destination_recipient_limit)\fR"
/* The maximal number of recipients per message for the smtp
/* message delivery transport.
/* .IP "\fBsmtp_connect_timeout (30s)\fR"
/* The Postfix SMTP client time limit for completing a TCP connection, or
/* zero (use the operating system built-in time limit).
/* .IP "\fBsmtp_helo_timeout (300s)\fR"
/* The Postfix SMTP client time limit for sending the HELO or EHLO command,
/* and for receiving the initial remote SMTP server response.
/* .IP "\fBlmtp_lhlo_timeout (300s)\fR"
/* The Postfix LMTP client time limit for sending the LHLO command,
/* and for receiving the initial remote LMTP server response.
/* .IP "\fBsmtp_xforward_timeout (300s)\fR"
/* The Postfix SMTP client time limit for sending the XFORWARD command,
/* and for receiving the remote SMTP server response.
/* .IP "\fBsmtp_mail_timeout (300s)\fR"
/* The Postfix SMTP client time limit for sending the MAIL FROM command,
/* and for receiving the remote SMTP server response.
/* .IP "\fBsmtp_rcpt_timeout (300s)\fR"
/* The Postfix SMTP client time limit for sending the SMTP RCPT TO
/* command, and for receiving the remote SMTP server response.
/* .IP "\fBsmtp_data_init_timeout (120s)\fR"
/* The Postfix SMTP client time limit for sending the SMTP DATA command,
/* and for receiving the remote SMTP server response.
/* .IP "\fBsmtp_data_xfer_timeout (180s)\fR"
/* The Postfix SMTP client time limit for sending the SMTP message content.
/* .IP "\fBsmtp_data_done_timeout (600s)\fR"
/* The Postfix SMTP client time limit for sending the SMTP ".", and
/* for receiving the remote SMTP server response.
/* .IP "\fBsmtp_quit_timeout (300s)\fR"
/* The Postfix SMTP client time limit for sending the QUIT command,
/* and for receiving the remote SMTP server response.
/* .PP
/* Available in Postfix version 2.1 and later:
/* .IP "\fBsmtp_mx_address_limit (5)\fR"
/* The maximal number of MX (mail exchanger) IP addresses that can
/* result from Postfix SMTP client mail exchanger lookups, or zero (no
/* limit).
/* .IP "\fBsmtp_mx_session_limit (2)\fR"
/* The maximal number of SMTP sessions per delivery request before
/* the Postfix SMTP client
/* gives up or delivers to a fall-back relay host, or zero (no
/* limit).
/* .IP "\fBsmtp_rset_timeout (20s)\fR"
/* The Postfix SMTP client time limit for sending the RSET command,
/* and for receiving the remote SMTP server response.
/* .PP
/* Available in Postfix version 2.2 and earlier:
/* .IP "\fBlmtp_cache_connection (yes)\fR"
/* Keep Postfix LMTP client connections open for up to $max_idle
/* seconds.
/* .PP
/* Available in Postfix version 2.2 and later:
/* .IP "\fBsmtp_connection_cache_destinations (empty)\fR"
/* Permanently enable SMTP connection caching for the specified
/* destinations.
/* .IP "\fBsmtp_connection_cache_on_demand (yes)\fR"
/* Temporarily enable SMTP connection caching while a destination
/* has a high volume of mail in the active queue.
/* .IP "\fBsmtp_connection_reuse_time_limit (300s)\fR"
/* The amount of time during which Postfix will use an SMTP
/* connection repeatedly.
/* .IP "\fBsmtp_connection_cache_time_limit (2s)\fR"
/* When SMTP connection caching is enabled, the amount of time that
/* an unused SMTP client socket is kept open before it is closed.
/* .PP
/* Available in Postfix version 2.3 and later:
/* .IP "\fBconnection_cache_protocol_timeout (5s)\fR"
/* Time limit for connection cache connect, send or receive
/* operations.
/* .PP
/* Available in Postfix version 2.9 and later:
/* .IP "\fBsmtp_per_record_deadline (no)\fR"
/* Change the behavior of the smtp_*_timeout time limits, from a
/* time limit per read or write system call, to a time limit to send
/* or receive a complete record (an SMTP command line, SMTP response
/* line, SMTP message content line, or TLS protocol message).
/* .PP
/* Available in Postfix version 2.11 and later:
/* .IP "\fBsmtp_connection_reuse_count_limit (0)\fR"
/* When SMTP connection caching is enabled, the number of times
/* that an SMTP session may be reused before it is closed, or zero (no
/* limit).
/* SMTPUTF8 CONTROLS
/* .ad
/* .fi
/* Preliminary SMTPUTF8 support is introduced with Postfix 3.0.
/* .IP "\fBsmtputf8_enable (yes)\fR"
/* Enable preliminary SMTPUTF8 support for the protocols described
/* in RFC 6531..6533.
/* .IP "\fBsmtputf8_autodetect_classes (sendmail, verify)\fR"
/* Detect that a message requires SMTPUTF8 support for the specified
/* mail origin classes.
/* TROUBLE SHOOTING CONTROLS
/* .ad
/* .fi
/* .IP "\fBdebug_peer_level (2)\fR"
/* The increment in verbose logging level when a remote client or
/* server matches a pattern in the debug_peer_list parameter.
/* .IP "\fBdebug_peer_list (empty)\fR"
/* Optional list of remote client or server hostname or network
/* address patterns that cause the verbose logging level to increase
/* by the amount specified in $debug_peer_level.
/* .IP "\fBerror_notice_recipient (postmaster)\fR"
/* The recipient of postmaster notifications about mail delivery
/* problems that are caused by policy, resource, software or protocol
/* errors.
/* .IP "\fBinternal_mail_filter_classes (empty)\fR"
/* What categories of Postfix-generated mail are subject to
/* before-queue content inspection by non_smtpd_milters, header_checks
/* and body_checks.
/* .IP "\fBnotify_classes (resource, software)\fR"
/* The list of error classes that are reported to the postmaster.
/* MISCELLANEOUS CONTROLS
/* .ad
/* .fi
/* .IP "\fBbest_mx_transport (empty)\fR"
/* Where the Postfix SMTP client should deliver mail when it detects
/* a "mail loops back to myself" error condition.
/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
/* The default location of the Postfix main.cf and master.cf
/* configuration files.
/* .IP "\fBdaemon_timeout (18000s)\fR"
/* How much time a Postfix daemon process may take to handle a
/* request before it is terminated by a built-in watchdog timer.
/* .IP "\fBdelay_logging_resolution_limit (2)\fR"
/* The maximal number of digits after the decimal point when logging
/* sub-second delay values.
/* .IP "\fBdisable_dns_lookups (no)\fR"
/* Disable DNS lookups in the Postfix SMTP and LMTP clients.
/* .IP "\fBinet_interfaces (all)\fR"
/* The network interface addresses that this mail system receives
/* mail on.
/* .IP "\fBinet_protocols (all)\fR"
/* The Internet protocols Postfix will attempt to use when making
/* or accepting connections.
/* .IP "\fBipc_timeout (3600s)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBlmtp_assume_final (no)\fR"
/* When a remote LMTP server announces no DSN support, assume that
/* the
/* server performs final delivery, and send "delivered" delivery status
/* notifications instead of "relayed".
/* .IP "\fBlmtp_tcp_port (24)\fR"
/* The default TCP port that the Postfix LMTP client connects to.
/* .IP "\fBmax_idle (100s)\fR"
/* The maximum amount of time that an idle Postfix daemon process waits
/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
/* The maximal number of incoming connections that a Postfix daemon
/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The process name of a Postfix command or daemon process.
/* .IP "\fBproxy_interfaces (empty)\fR"
/* The network interface addresses that this mail system receives mail
/* on by way of a proxy or network address translation unit.
/* .IP "\fBsmtp_address_preference (any)\fR"
/* The address type ("ipv6", "ipv4" or "any") that the Postfix
/* SMTP client will try first, when a destination has IPv6 and IPv4
/* addresses with equal MX preference.
/* .IP "\fBsmtp_bind_address (empty)\fR"
/* An optional numerical network address that the Postfix SMTP client
/* should bind to when making an IPv4 connection.
/* .IP "\fBsmtp_bind_address6 (empty)\fR"
/* An optional numerical network address that the Postfix SMTP client
/* should bind to when making an IPv6 connection.
/* .IP "\fBsmtp_helo_name ($myhostname)\fR"
/* The hostname to send in the SMTP HELO or EHLO command.
/* .IP "\fBlmtp_lhlo_name ($myhostname)\fR"
/* The hostname to send in the LMTP LHLO command.
/* .IP "\fBsmtp_host_lookup (dns)\fR"
/* What mechanisms the Postfix SMTP client uses to look up a host's
/* IP address.
/* .IP "\fBsmtp_randomize_addresses (yes)\fR"
/* Randomize the order of equal-preference MX host addresses.
/* .IP "\fBsyslog_facility (mail)\fR"
/* The syslog facility of Postfix logging.
/* .IP "\fBsyslog_name (see 'postconf -d' output)\fR"
/* The mail system name that is prepended to the process name in syslog
/* records, so that "smtpd" becomes, for example, "postfix/smtpd".
/* .PP
/* Available with Postfix 2.2 and earlier:
/* .IP "\fBfallback_relay (empty)\fR"
/* Optional list of relay hosts for SMTP destinations that can't be
/* found or that are unreachable.
/* .PP
/* Available with Postfix 2.3 and later:
/* .IP "\fBsmtp_fallback_relay ($fallback_relay)\fR"
/* Optional list of relay hosts for SMTP destinations that can't be
/* found or that are unreachable.
/* .PP
/* Available with Postfix 3.0 and later:
/* .IP "\fBsmtp_address_verify_target (rcpt)\fR"
/* In the context of email address verification, the SMTP protocol
/* stage that determines whether an email address is deliverable.
/* .PP
/* Available with Postfix 3.1 and later:
/* .IP "\fBlmtp_fallback_relay (empty)\fR"
/* Optional list of relay hosts for LMTP destinations that can't be
/* found or that are unreachable.
/* SEE ALSO
/* generic(5), output address rewriting
/* header_checks(5), message header content inspection
/* body_checks(5), body parts content inspection
/* qmgr(8), queue manager
/* bounce(8), delivery status reports
/* scache(8), connection cache server
/* postconf(5), configuration parameters
/* master(5), generic daemon options
/* master(8), process manager
/* tlsmgr(8), TLS session and PRNG management
/* syslogd(8), system logging
/* README FILES
/* .ad
/* .fi
/* Use "\fBpostconf readme_directory\fR" or
/* "\fBpostconf html_directory\fR" to locate this information.
/* .na
/* .nf
/* SASL_README, Postfix SASL howto
/* TLS_README, Postfix STARTTLS howto
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*
/* Wietse Venema
/* Google, Inc.
/* 111 8th Avenue
/* New York, NY 10011, USA
/*
/* Command pipelining in cooperation with:
/* Jon Ribbens
/* Oaktree Internet Solutions Ltd.,
/* Internet House,
/* Canal Basin,
/* Coventry,
/* CV1 4LY, United Kingdom.
/*
/* SASL support originally by:
/* Till Franke
/* SuSE Rhein/Main AG
/* 65760 Eschborn, Germany
/*
/* TLS support originally by:
/* Lutz Jaenicke
/* BTU Cottbus
/* Allgemeine Elektrotechnik
/* Universitaetsplatz 3-4
/* D-03044 Cottbus, Germany
/*
/* Revised TLS and SMTP connection cache support by:
/* Victor Duchovni
/* Morgan Stanley
/*--*/
/* System library. */
#include <sys_defs.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <dict.h>
#include <stringops.h>
/* Utility library. */
#include <msg.h>
#include <mymalloc.h>
#include <name_mask.h>
#include <name_code.h>
/* Global library. */
#include <deliver_request.h>
#include <mail_params.h>
#include <mail_version.h>
#include <mail_conf.h>
#include <debug_peer.h>
#include <flush_clnt.h>
#include <scache.h>
#include <string_list.h>
#include <maps.h>
#include <ext_prop.h>
/* DNS library. */
#include <dns.h>
/* Single server skeleton. */
#include <mail_server.h>
/* Application-specific. */
#include "smtp.h"
#include "smtp_sasl.h"
/*
* Tunable parameters. These have compiled-in defaults that can be overruled
* by settings in the global Postfix configuration file.
*/
int var_smtp_conn_tmout;
int var_smtp_helo_tmout;
int var_smtp_xfwd_tmout;
int var_smtp_mail_tmout;
int var_smtp_rcpt_tmout;
int var_smtp_data0_tmout;
int var_smtp_data1_tmout;
int var_smtp_data2_tmout;
int var_smtp_rset_tmout;
int var_smtp_quit_tmout;
char *var_inet_interfaces;
char *var_notify_classes;
int var_smtp_skip_5xx_greeting;
int var_ign_mx_lookup_err;
int var_skip_quit_resp;
char *var_fallback_relay;
char *var_bestmx_transp;
char *var_error_rcpt;
int var_smtp_always_ehlo;
int var_smtp_never_ehlo;
char *var_smtp_sasl_opts;
char *var_smtp_sasl_path;
char *var_smtp_sasl_passwd;
bool var_smtp_sasl_enable;
char *var_smtp_sasl_mechs;
char *var_smtp_sasl_type;
char *var_smtp_bind_addr;
char *var_smtp_bind_addr6;
char *var_smtp_vrfy_tgt;
bool var_smtp_rand_addr;
int var_smtp_pix_thresh;
int var_queue_run_delay;
int var_min_backoff_time;
int var_smtp_pix_delay;
int var_smtp_line_limit;
char *var_smtp_helo_name;
char *var_smtp_host_lookup;
bool var_smtp_quote_821_env;
bool var_smtp_defer_mxaddr;
bool var_smtp_send_xforward;
int var_smtp_mxaddr_limit;
int var_smtp_mxsess_limit;
int var_smtp_cache_conn;
int var_smtp_reuse_time;
int var_smtp_reuse_count;
char *var_smtp_cache_dest;
char *var_scache_service; /* You can now leave this here. */
bool var_smtp_cache_demand;
char *var_smtp_ehlo_dis_words;
char *var_smtp_ehlo_dis_maps;
char *var_smtp_addr_pref;
char *var_smtp_tls_level;
bool var_smtp_use_tls;
bool var_smtp_enforce_tls;
char *var_smtp_tls_per_site;
char *var_smtp_tls_policy;
bool var_smtp_tls_wrappermode;
#ifdef USE_TLS
char *var_smtp_sasl_tls_opts;
char *var_smtp_sasl_tlsv_opts;
int var_smtp_starttls_tmout;
char *var_smtp_tls_CAfile;
char *var_smtp_tls_CApath;
char *var_smtp_tls_cert_file;
char *var_smtp_tls_mand_ciph;
char *var_smtp_tls_excl_ciph;
char *var_smtp_tls_mand_excl;
char *var_smtp_tls_dcert_file;
char *var_smtp_tls_dkey_file;
bool var_smtp_tls_enforce_peername;
char *var_smtp_tls_key_file;
char *var_smtp_tls_loglevel;
bool var_smtp_tls_note_starttls_offer;
char *var_smtp_tls_mand_proto;
char *var_smtp_tls_sec_cmatch;
int var_smtp_tls_scert_vd;
char *var_smtp_tls_vfy_cmatch;
char *var_smtp_tls_fpt_cmatch;
char *var_smtp_tls_fpt_dgst;
char *var_smtp_tls_tafile;
char *var_smtp_tls_proto;
char *var_smtp_tls_ciph;
char *var_smtp_tls_eccert_file;
char *var_smtp_tls_eckey_file;
bool var_smtp_tls_blk_early_mail_reply;
bool var_smtp_tls_force_tlsa;
char *var_smtp_tls_insecure_mx_policy;
#endif
char *var_smtp_generic_maps;
char *var_prop_extension;
bool var_smtp_sender_auth;
char *var_lmtp_tcp_port;
int var_scache_proto_tmout;
bool var_smtp_cname_overr;
char *var_smtp_pix_bug_words;
char *var_smtp_pix_bug_maps;
char *var_cyrus_conf_path;
char *var_smtp_head_chks;
char *var_smtp_mime_chks;
char *var_smtp_nest_chks;
char *var_smtp_body_chks;
char *var_smtp_resp_filter;
bool var_lmtp_assume_final;
char *var_smtp_dns_res_opt;
char *var_smtp_dns_support;
bool var_smtp_rec_deadline;
bool var_smtp_dummy_mail_auth;
char *var_smtp_dsn_filter;
char *var_smtp_dns_re_filter;
/* Special handling of 535 AUTH errors. */
char *var_smtp_sasl_auth_cache_name;
int var_smtp_sasl_auth_cache_time;
bool var_smtp_sasl_auth_soft_bounce;
/*
* Global variables.
*/
int smtp_mode;
int smtp_host_lookup_mask;
int smtp_dns_support;
STRING_LIST *smtp_cache_dest;
SCACHE *smtp_scache;
MAPS *smtp_ehlo_dis_maps;
MAPS *smtp_generic_maps;
int smtp_ext_prop_mask;
unsigned smtp_dns_res_opt;
MAPS *smtp_pix_bug_maps;
HBC_CHECKS *smtp_header_checks; /* limited header checks */
HBC_CHECKS *smtp_body_checks; /* limited body checks */
#ifdef USE_TLS
/*
* OpenSSL client state (opaque handle)
*/
TLS_APPL_STATE *smtp_tls_ctx;
int smtp_tls_insecure_mx_policy;
#endif
/*
* IPv6 preference.
*/
static int smtp_addr_pref;
/* deliver_message - deliver message with extreme prejudice */
static int deliver_message(const char *service, DELIVER_REQUEST *request)
{
SMTP_STATE *state;
int result;
if (msg_verbose)
msg_info("deliver_message: from %s", request->sender);
/*
* Sanity checks. The smtp server is unprivileged and chrooted, so we can
* afford to distribute the data censoring code, instead of having it all
* in one place.
*/
if (request->nexthop[0] == 0)
msg_fatal("empty nexthop hostname");
if (request->rcpt_list.len <= 0)
msg_fatal("recipient count: %d", request->rcpt_list.len);
/*
* Initialize. Bundle all information about the delivery request, so that
* we can produce understandable diagnostics when something goes wrong
* many levels below. The alternative would be to make everything global.
*/
state = smtp_state_alloc();
state->request = request;
state->src = request->fp;
state->service = service;
state->misc_flags |= smtp_addr_pref;
SMTP_RCPT_INIT(state);
/*
* Establish an SMTP session and deliver this message to all requested
* recipients. At the end, notify the postmaster of any protocol errors.
* Optionally deliver mail locally when this machine is the best mail
* exchanger.
*/
result = smtp_connect(state);
/*
* Clean up.
*/
smtp_state_free(state);
return (result);
}
/* smtp_service - perform service for client */
static void smtp_service(VSTREAM *client_stream, char *service, char **argv)
{
DELIVER_REQUEST *request;
int status;
/*
* Sanity check. This service takes no command-line arguments.
*/
if (argv[0])
msg_fatal("unexpected command-line argument: %s", argv[0]);
/*
* This routine runs whenever a client connects to the UNIX-domain socket
* dedicated to remote SMTP delivery service. What we see below is a
* little protocol to (1) tell the queue manager that we are ready, (2)
* read a request from the queue manager, and (3) report the completion
* status of that request. All connection-management stuff is handled by
* the common code in single_server.c.
*/
if ((request = deliver_request_read(client_stream)) != 0) {
status = deliver_message(service, request);
deliver_request_done(client_stream, request, status);
}
}
/* post_init - post-jail initialization */
static void post_init(char *unused_name, char **unused_argv)
{
static const NAME_MASK lookup_masks[] = {
SMTP_HOST_LOOKUP_DNS, SMTP_HOST_FLAG_DNS,
SMTP_HOST_LOOKUP_NATIVE, SMTP_HOST_FLAG_NATIVE,
0,
};
static const NAME_MASK dns_res_opt_masks[] = {
SMTP_DNS_RES_OPT_DEFNAMES, RES_DEFNAMES,
SMTP_DNS_RES_OPT_DNSRCH, RES_DNSRCH,
0,
};
static const NAME_CODE dns_support[] = {
SMTP_DNS_SUPPORT_DISABLED, SMTP_DNS_DISABLED,
SMTP_DNS_SUPPORT_ENABLED, SMTP_DNS_ENABLED,
#if (RES_USE_DNSSEC != 0) && (RES_USE_EDNS0 != 0)
SMTP_DNS_SUPPORT_DNSSEC, SMTP_DNS_DNSSEC,
#endif
0, SMTP_DNS_INVALID,
};
if (*var_smtp_dns_support == 0) {
/* Backwards compatible empty setting */
smtp_dns_support =
var_disable_dns ? SMTP_DNS_DISABLED : SMTP_DNS_ENABLED;
} else {
smtp_dns_support =
name_code(dns_support, NAME_CODE_FLAG_NONE, var_smtp_dns_support);
if (smtp_dns_support == SMTP_DNS_INVALID)
msg_fatal("invalid %s: \"%s\"", VAR_LMTP_SMTP(DNS_SUPPORT),
var_smtp_dns_support);
var_disable_dns = (smtp_dns_support == SMTP_DNS_DISABLED);
}
#ifdef USE_TLS
if (smtp_mode) {
smtp_tls_insecure_mx_policy =
tls_level_lookup(var_smtp_tls_insecure_mx_policy);
switch (smtp_tls_insecure_mx_policy) {
case TLS_LEV_MAY:
case TLS_LEV_ENCRYPT:
case TLS_LEV_DANE:
break;
default:
msg_fatal("invalid %s: \"%s\"", VAR_SMTP_TLS_INSECURE_MX_POLICY,
var_smtp_tls_insecure_mx_policy);
}
}
#endif
/*
* Select hostname lookup mechanisms.
*/
if (smtp_dns_support == SMTP_DNS_DISABLED)
smtp_host_lookup_mask = SMTP_HOST_FLAG_NATIVE;
else
smtp_host_lookup_mask =
name_mask(VAR_LMTP_SMTP(HOST_LOOKUP), lookup_masks,
var_smtp_host_lookup);
if (msg_verbose)
msg_info("host name lookup methods: %s",
str_name_mask(VAR_LMTP_SMTP(HOST_LOOKUP), lookup_masks,
smtp_host_lookup_mask));
/*
* Session cache instance.
*/
if (*var_smtp_cache_dest || var_smtp_cache_demand)
#if 0
smtp_scache = scache_multi_create();
#else
smtp_scache = scache_clnt_create(var_scache_service,
var_scache_proto_tmout,
var_ipc_idle_limit,
var_ipc_ttl_limit);
#endif
/*
* Select DNS query flags.
*/
smtp_dns_res_opt = name_mask(VAR_LMTP_SMTP(DNS_RES_OPT), dns_res_opt_masks,
var_smtp_dns_res_opt);
/*
* Address verification.
*/
smtp_vrfy_init();
}
/* pre_init - pre-jail initialization */
static void pre_init(char *unused_name, char **unused_argv)
{
int use_tls;
static const NAME_CODE addr_pref_map[] = {
INET_PROTO_NAME_IPV6, SMTP_MISC_FLAG_PREF_IPV6,
INET_PROTO_NAME_IPV4, SMTP_MISC_FLAG_PREF_IPV4,
INET_PROTO_NAME_ANY, 0,
0, -1,
};
/*
* Turn on per-peer debugging.
*/
debug_peer_init();
/*
* SASL initialization.
*/
if (var_smtp_sasl_enable)
#ifdef USE_SASL_AUTH
smtp_sasl_initialize();
#else
msg_warn("%s is true, but SASL support is not compiled in",
VAR_LMTP_SMTP(SASL_ENABLE));
#endif
if (*var_smtp_tls_level != 0)
#ifdef USE_TLS
switch (tls_level_lookup(var_smtp_tls_level)) {
case TLS_LEV_SECURE:
case TLS_LEV_VERIFY:
case TLS_LEV_DANE_ONLY:
case TLS_LEV_FPRINT:
case TLS_LEV_ENCRYPT:
var_smtp_use_tls = var_smtp_enforce_tls = 1;
break;
case TLS_LEV_DANE:
case TLS_LEV_MAY:
var_smtp_use_tls = 1;
var_smtp_enforce_tls = 0;
break;
case TLS_LEV_NONE:
var_smtp_use_tls = var_smtp_enforce_tls = 0;
break;
default:
/* tls_level_lookup() logs no warning. */
/* session_tls_init() assumes that var_smtp_tls_level is sane. */
msg_fatal("Invalid TLS level \"%s\"", var_smtp_tls_level);
}
#endif
use_tls = (var_smtp_use_tls || var_smtp_enforce_tls);
/*
* Initialize the TLS data before entering the chroot jail
*/
if (use_tls || var_smtp_tls_per_site[0] || var_smtp_tls_policy[0]) {
#ifdef USE_TLS
TLS_CLIENT_INIT_PROPS props;
/*
* We get stronger type safety and a cleaner interface by combining
* the various parameters into a single tls_client_props structure.
*
* Large parameter lists are error-prone, so we emulate a language
* feature that C does not have natively: named parameter lists.
*/
smtp_tls_ctx =
TLS_CLIENT_INIT(&props,
log_param = VAR_LMTP_SMTP(TLS_LOGLEVEL),
log_level = var_smtp_tls_loglevel,
verifydepth = var_smtp_tls_scert_vd,
cache_type = LMTP_SMTP_SUFFIX(TLS_MGR_SCACHE),
cert_file = var_smtp_tls_cert_file,
key_file = var_smtp_tls_key_file,
dcert_file = var_smtp_tls_dcert_file,
dkey_file = var_smtp_tls_dkey_file,
eccert_file = var_smtp_tls_eccert_file,
eckey_file = var_smtp_tls_eckey_file,
CAfile = var_smtp_tls_CAfile,
CApath = var_smtp_tls_CApath,
mdalg = var_smtp_tls_fpt_dgst);
smtp_tls_list_init();
#else
msg_warn("TLS has been selected, but TLS support is not compiled in");
#endif
}
/*
* Flush client.
*/
flush_init();
/*
* Session cache domain list.
*/
if (*var_smtp_cache_dest)
smtp_cache_dest = string_list_init(VAR_SMTP_CACHE_DEST,
MATCH_FLAG_RETURN,
var_smtp_cache_dest);
/*
* EHLO keyword filter.
*/
if (*var_smtp_ehlo_dis_maps)
smtp_ehlo_dis_maps = maps_create(VAR_LMTP_SMTP(EHLO_DIS_MAPS),
var_smtp_ehlo_dis_maps,
DICT_FLAG_LOCK);
/*
* PIX bug workarounds.
*/
if (*var_smtp_pix_bug_maps)
smtp_pix_bug_maps = maps_create(VAR_LMTP_SMTP(PIX_BUG_MAPS),
var_smtp_pix_bug_maps,
DICT_FLAG_LOCK);
/*
* Generic maps.
*/
if (*var_prop_extension)
smtp_ext_prop_mask =
ext_prop_mask(VAR_PROP_EXTENSION, var_prop_extension);
if (*var_smtp_generic_maps)
smtp_generic_maps =
maps_create(VAR_LMTP_SMTP(GENERIC_MAPS), var_smtp_generic_maps,
DICT_FLAG_LOCK | DICT_FLAG_FOLD_FIX
| DICT_FLAG_UTF8_REQUEST);
/*
* Header/body checks.
*/
smtp_header_checks = hbc_header_checks_create(
VAR_LMTP_SMTP(HEAD_CHKS), var_smtp_head_chks,
VAR_LMTP_SMTP(MIME_CHKS), var_smtp_mime_chks,
VAR_LMTP_SMTP(NEST_CHKS), var_smtp_nest_chks,
smtp_hbc_callbacks);
smtp_body_checks = hbc_body_checks_create(
VAR_LMTP_SMTP(BODY_CHKS), var_smtp_body_chks,
smtp_hbc_callbacks);
/*
* Server reply filter.
*/
if (*var_smtp_resp_filter)
smtp_chat_resp_filter =
dict_open(var_smtp_resp_filter, O_RDONLY,
DICT_FLAG_LOCK | DICT_FLAG_FOLD_FIX);
/*
* Address family preference.
*/
if (*var_smtp_addr_pref) {
smtp_addr_pref = name_code(addr_pref_map, NAME_CODE_FLAG_NONE,
var_smtp_addr_pref);
if (smtp_addr_pref < 0)
msg_fatal("bad %s value: %s", VAR_LMTP_SMTP(ADDR_PREF),
var_smtp_addr_pref);
}
/*
* DNS reply filter.
*/
if (*var_smtp_dns_re_filter)
dns_rr_filter_compile(VAR_LMTP_SMTP(DNS_RE_FILTER),
var_smtp_dns_re_filter);
}
/* pre_accept - see if tables have changed */
static void pre_accept(char *unused_name, char **unused_argv)
{
const char *table;
if ((table = dict_changed_name()) != 0) {
msg_info("table %s has changed -- restarting", table);
exit(0);
}
}
MAIL_VERSION_STAMP_DECLARE;
/* main - pass control to the single-threaded skeleton */
int main(int argc, char **argv)
{
char *sane_procname;
#include "smtp_params.c"
#include "lmtp_params.c"
/*
* Fingerprint executables and core dumps.
*/
MAIL_VERSION_STAMP_ALLOCATE;
/*
* XXX At this point, var_procname etc. are not initialized.
*
* The process name, "smtp" or "lmtp", determines the protocol, the DSN
* server reply type, SASL service information lookup, and more. Prepare
* for the possibility there may be another personality.
*/
sane_procname = sane_basename((VSTRING *) 0, argv[0]);
if (strcmp(sane_procname, "smtp") == 0)
smtp_mode = 1;
else if (strcmp(sane_procname, "lmtp") == 0)
smtp_mode = 0;
else
msg_fatal("unexpected process name \"%s\" - "
"specify \"smtp\" or \"lmtp\"", var_procname);
/*
* Initialize with the LMTP or SMTP parameter name space.
*/
single_server_main(argc, argv, smtp_service,
CA_MAIL_SERVER_TIME_TABLE(smtp_mode ?
smtp_time_table : lmtp_time_table),
CA_MAIL_SERVER_INT_TABLE(smtp_mode ?
smtp_int_table : lmtp_int_table),
CA_MAIL_SERVER_STR_TABLE(smtp_mode ?
smtp_str_table : lmtp_str_table),
CA_MAIL_SERVER_BOOL_TABLE(smtp_mode ?
smtp_bool_table : lmtp_bool_table),
CA_MAIL_SERVER_PRE_INIT(pre_init),
CA_MAIL_SERVER_POST_INIT(post_init),
CA_MAIL_SERVER_PRE_ACCEPT(pre_accept),
CA_MAIL_SERVER_BOUNCE_INIT(VAR_SMTP_DSN_FILTER,
&var_smtp_dsn_filter),
0);
}