/*++ /* NAME /* smtpd 3h /* SUMMARY /* smtp server /* SYNOPSIS /* include "smtpd.h" /* DESCRIPTION /* .nf /* * System library. */ #include #include /* * Utility library. */ #include #include #include #include /* * Global library. */ #include /* * Postfix TLS library. */ #include /* * Milter library. */ #include /* * Variables that keep track of conversation state. There is only one SMTP * conversation at a time, so the state variables can be made global. And * some of this has to be global anyway, so that the run-time error handler * can clean up in case of a fatal error deep down in some library routine. */ typedef struct SMTPD_DEFER { int active; /* is this active */ VSTRING *reason; /* reason for deferral */ VSTRING *dsn; /* DSN detail */ int code; /* SMTP reply code */ int class; /* error notification class */ } SMTPD_DEFER; typedef struct { int flags; /* XFORWARD server state */ char *name; /* name for access control */ char *addr; /* address for access control */ char *port; /* port for logging */ char *namaddr; /* name[address]:port */ char *rfc_addr; /* address for RFC 2821 */ char *protocol; /* email protocol */ char *helo_name; /* helo/ehlo parameter */ char *ident; /* local message identifier */ char *domain; /* rewrite context */ } SMTPD_XFORWARD_ATTR; typedef struct { int flags; /* see below */ int err; /* cleanup server/queue file errors */ VSTREAM *client; /* SMTP client handle */ VSTRING *buffer; /* SMTP client buffer */ VSTRING *addr_buf; /* internalized address buffer */ char *service; /* for event rate control */ struct timeval arrival_time; /* start of MAIL FROM transaction */ char *name; /* verified client hostname */ char *reverse_name; /* unverified client hostname */ char *addr; /* client host address string */ char *port; /* port for logging */ char *namaddr; /* name[address]:port */ char *rfc_addr; /* address for RFC 2821 */ int addr_family; /* address family */ char *dest_addr; /* Dovecot AUTH, Milter {daemon_addr} */ char *dest_port; /* Milter {daemon_port} */ struct sockaddr_storage sockaddr; /* binary client endpoint */ SOCKADDR_SIZE sockaddr_len; /* binary client endpoint */ struct sockaddr_storage dest_sockaddr; /* binary local endpoint */ SOCKADDR_SIZE dest_sockaddr_len; /* binary local endpoint */ int name_status; /* 2=ok 4=soft 5=hard 6=forged */ int reverse_name_status; /* 2=ok 4=soft 5=hard */ int conn_count; /* connections from this client */ int conn_rate; /* connection rate for this client */ int error_count; /* reset after DOT */ int error_mask; /* client errors */ int notify_mask; /* what to report to postmaster */ char *helo_name; /* client HELO/EHLO argument */ char *queue_id; /* from cleanup server/queue file */ VSTREAM *cleanup; /* cleanup server/queue file handle */ MAIL_STREAM *dest; /* another server/file handle */ int rcpt_count; /* number of accepted recipients */ char *access_denied; /* fixme */ ARGV *history; /* protocol transcript */ char *reason; /* cause of connection loss */ char *sender; /* sender address */ char *encoding; /* owned by mail_cmd() */ char *verp_delims; /* owned by mail_cmd() */ char *recipient; /* recipient address */ char *etrn_name; /* client ETRN argument */ char *protocol; /* SMTP or ESMTP */ char *where; /* protocol stage */ int recursion; /* Kellerspeicherpegelanzeiger */ off_t msg_size; /* MAIL FROM message size */ off_t act_size; /* END-OF-DATA message size */ int junk_cmds; /* counter */ int rcpt_overshoot; /* counter */ char *rewrite_context; /* address rewriting context */ /* * SASL specific. */ #ifdef USE_SASL_AUTH struct XSASL_SERVER *sasl_server; VSTRING *sasl_reply; char *sasl_mechanism_list; char *sasl_method; char *sasl_username; char *sasl_sender; #endif /* * Specific to smtpd access checks. */ int sender_rcptmap_checked; /* sender validated against maps */ int recipient_rcptmap_checked; /* recipient validated against maps */ int warn_if_reject; /* force reject into warning */ SMTPD_DEFER defer_if_reject; /* force reject into deferral */ SMTPD_DEFER defer_if_permit; /* force permit into deferral */ int defer_if_permit_client; /* force permit into warning */ int defer_if_permit_helo; /* force permit into warning */ int defer_if_permit_sender; /* force permit into warning */ int discard; /* discard message */ char *saved_filter; /* postponed filter action */ char *saved_redirect; /* postponed redirect action */ ARGV *saved_bcc; /* postponed bcc action */ int saved_flags; /* postponed hold/discard */ #ifdef DELAY_ACTION int saved_delay; /* postponed deferred delay */ #endif VSTRING *expand_buf; /* scratch space for $name expansion */ ARGV *prepend; /* prepended headers */ VSTRING *instance; /* policy query correlation */ int seqno; /* policy query correlation */ int ehlo_discard_mask; /* suppressed EHLO features */ char *dsn_envid; /* temporary MAIL FROM state */ int dsn_ret; /* temporary MAIL FROM state */ VSTRING *dsn_buf; /* scratch space for xtext expansion */ VSTRING *dsn_orcpt_buf; /* scratch space for ORCPT parsing */ /* * Pass-through proxy client. */ struct SMTPD_PROXY *proxy; char *proxy_mail; /* owned by mail_cmd() */ /* * XFORWARD server state. */ SMTPD_XFORWARD_ATTR xforward; /* up-stream logging info */ /* * TLS related state. */ #ifdef USE_TLS #ifdef USE_TLSPROXY VSTREAM *tlsproxy; /* tlsproxy(8) temp. handle */ #endif TLS_SESS_STATE *tls_context; /* TLS session state */ #endif /* * Milter support. */ const char **milter_argv; /* SMTP command vector */ ssize_t milter_argc; /* SMTP command vector */ const char *milter_reject_text; /* input to call-back from Milter */ MILTERS *milters; /* Milter initialization status. */ /* * EHLO temporary space. */ VSTRING *ehlo_buf; ARGV *ehlo_argv; /* * BDAT processing state. */ #define SMTPD_BDAT_STAT_NONE 0 /* not processing BDAT */ #define SMTPD_BDAT_STAT_OK 1 /* accepting BDAT chunks */ #define SMTPD_BDAT_STAT_ERROR 2 /* skipping BDAT chunks */ int bdat_state; /* see above */ VSTREAM *bdat_get_stream; /* memory stream from BDAT chunk */ VSTRING *bdat_get_buffer; /* read from memory stream */ int bdat_prev_rec_type; } SMTPD_STATE; #define SMTPD_FLAG_HANGUP (1<<0) /* 421/521 disconnect */ #define SMTPD_FLAG_ILL_PIPELINING (1<<1) /* inappropriate pipelining */ #define SMTPD_FLAG_AUTH_USED (1<<2) /* don't reuse SASL state */ #define SMTPD_FLAG_SMTPUTF8 (1<<3) /* RFC 6531/2 transaction */ #define SMTPD_FLAG_NEED_MILTER_ABORT (1<<4) /* undo milter_mail_event() */ /* Security: don't reset SMTPD_FLAG_AUTH_USED. */ #define SMTPD_MASK_MAIL_KEEP \ ~(SMTPD_FLAG_SMTPUTF8) /* Fix 20140706 */ #define SMTPD_STATE_XFORWARD_INIT (1<<0) /* xforward preset done */ #define SMTPD_STATE_XFORWARD_NAME (1<<1) /* client name received */ #define SMTPD_STATE_XFORWARD_ADDR (1<<2) /* client address received */ #define SMTPD_STATE_XFORWARD_PROTO (1<<3) /* protocol received */ #define SMTPD_STATE_XFORWARD_HELO (1<<4) /* client helo received */ #define SMTPD_STATE_XFORWARD_IDENT (1<<5) /* message identifier */ #define SMTPD_STATE_XFORWARD_DOMAIN (1<<6) /* address context */ #define SMTPD_STATE_XFORWARD_PORT (1<<7) /* client port received */ #define SMTPD_STATE_XFORWARD_CLIENT_MASK \ (SMTPD_STATE_XFORWARD_NAME | SMTPD_STATE_XFORWARD_ADDR \ | SMTPD_STATE_XFORWARD_PROTO | SMTPD_STATE_XFORWARD_HELO \ | SMTPD_STATE_XFORWARD_PORT) extern void smtpd_state_init(SMTPD_STATE *, VSTREAM *, const char *); extern void smtpd_state_reset(SMTPD_STATE *); /* * Conversation stages. This is used for "lost connection after XXX" * diagnostics. */ #define SMTPD_AFTER_CONNECT "CONNECT" #define SMTPD_AFTER_DATA "DATA content" #define SMTPD_AFTER_BDAT "BDAT content" #define SMTPD_AFTER_EOM "END-OF-MESSAGE" /* * Other stages. These are sometimes used to change the way information is * logged or what information will be available for access control. */ #define SMTPD_CMD_HELO "HELO" #define SMTPD_CMD_EHLO "EHLO" #define SMTPD_CMD_STARTTLS "STARTTLS" #define SMTPD_CMD_AUTH "AUTH" #define SMTPD_CMD_MAIL "MAIL" #define SMTPD_CMD_RCPT "RCPT" #define SMTPD_CMD_DATA "DATA" #define SMTPD_CMD_BDAT "BDAT" #define SMTPD_CMD_EOD SMTPD_AFTER_EOM /* XXX Was: END-OF-DATA */ #define SMTPD_CMD_RSET "RSET" #define SMTPD_CMD_NOOP "NOOP" #define SMTPD_CMD_VRFY "VRFY" #define SMTPD_CMD_ETRN "ETRN" #define SMTPD_CMD_QUIT "QUIT" #define SMTPD_CMD_XCLIENT "XCLIENT" #define SMTPD_CMD_XFORWARD "XFORWARD" #define SMTPD_CMD_UNKNOWN "UNKNOWN" /* * Representation of unknown and non-existent client information. Throughout * Postfix, we use the "unknown" string value for unknown client information * (e.g., unknown remote client hostname), and we use the empty string, null * pointer or "no queue file record" for non-existent client information * (e.g., no HELO command, or local submission). * * Inside the SMTP server, unknown real client attributes are represented by * the string "unknown", and non-existent HELO is represented as a null * pointer. The SMTP server uses this same representation internally for * forwarded client attributes; the XFORWARD syntax makes no distinction * between unknown (remote submission) and non-existent (local submission). * * The SMTP client sends forwarded client attributes only when upstream client * attributes exist (i.e. remote submission). Thus, local submissions will * appear to come from an SMTP-based content filter, which is acceptable. * * Known/unknown client attribute values use the SMTP server's internal * representation in queue files, in queue manager delivery requests, and in * delivery agent $name expansions. * * Non-existent attribute values are never present in queue files. Non-existent * information is represented as empty strings in queue manager delivery * requests and in delivery agent $name expansions. */ #define CLIENT_ATTR_UNKNOWN "unknown" #define CLIENT_NAME_UNKNOWN CLIENT_ATTR_UNKNOWN #define CLIENT_ADDR_UNKNOWN CLIENT_ATTR_UNKNOWN #define CLIENT_PORT_UNKNOWN CLIENT_ATTR_UNKNOWN #define CLIENT_NAMADDR_UNKNOWN CLIENT_ATTR_UNKNOWN #define CLIENT_HELO_UNKNOWN 0 #define CLIENT_PROTO_UNKNOWN CLIENT_ATTR_UNKNOWN #define CLIENT_IDENT_UNKNOWN 0 #define CLIENT_DOMAIN_UNKNOWN 0 #define CLIENT_LOGIN_UNKNOWN 0 #define SERVER_ATTR_UNKNOWN "unknown" #define SERVER_ADDR_UNKNOWN SERVER_ATTR_UNKNOWN #define SERVER_PORT_UNKNOWN SERVER_ATTR_UNKNOWN #define IS_AVAIL_CLIENT_ATTR(v) ((v) && strcmp((v), CLIENT_ATTR_UNKNOWN)) #define IS_AVAIL_CLIENT_NAME(v) IS_AVAIL_CLIENT_ATTR(v) #define IS_AVAIL_CLIENT_ADDR(v) IS_AVAIL_CLIENT_ATTR(v) #define IS_AVAIL_CLIENT_PORT(v) IS_AVAIL_CLIENT_ATTR(v) #define IS_AVAIL_CLIENT_NAMADDR(v) IS_AVAIL_CLIENT_ATTR(v) #define IS_AVAIL_CLIENT_HELO(v) ((v) != 0) #define IS_AVAIL_CLIENT_PROTO(v) IS_AVAIL_CLIENT_ATTR(v) #define IS_AVAIL_CLIENT_IDENT(v) ((v) != 0) #define IS_AVAIL_CLIENT_DOMAIN(v) ((v) != 0) /* * If running in stand-alone mode, do not try to talk to Postfix daemons but * write to queue file instead. */ #define SMTPD_STAND_ALONE_STREAM(stream) \ (stream == VSTREAM_IN && getuid() != var_owner_uid) #define SMTPD_STAND_ALONE(state) \ (state->client == VSTREAM_IN && getuid() != var_owner_uid) /* * If running as proxy front-end, disable actions that require communication * with the cleanup server. */ #define USE_SMTPD_PROXY(state) \ (SMTPD_STAND_ALONE(state) == 0 && *var_smtpd_proxy_filt) /* * Are we in a MAIL transaction? */ #define SMTPD_IN_MAIL_TRANSACTION(state) ((state)->sender != 0) /* * Are we processing BDAT requests? */ #define SMTPD_PROCESSING_BDAT(state) \ ((state)->bdat_state != SMTPD_BDAT_STAT_NONE) /* * SMTPD peer information lookup. */ extern void smtpd_peer_init(SMTPD_STATE *state); extern void smtpd_peer_reset(SMTPD_STATE *state); extern void smtpd_peer_from_default(SMTPD_STATE *); extern int smtpd_peer_from_haproxy(SMTPD_STATE *); #define SMTPD_PEER_CODE_OK 2 #define SMTPD_PEER_CODE_TEMP 4 #define SMTPD_PEER_CODE_PERM 5 #define SMTPD_PEER_CODE_FORGED 6 /* * Construct name[addr] or name[addr]:port as appropriate */ #define SMTPD_BUILD_NAMADDRPORT(name, addr, port) \ concatenate((name), "[", (addr), "]", \ var_smtpd_client_port_log ? ":" : (char *) 0, \ (port), (char *) 0) /* * Don't mix information from the current SMTP session with forwarded * information from an up-stream session. */ #define HAVE_FORWARDED_CLIENT_ATTR(s) \ ((s)->xforward.flags & SMTPD_STATE_XFORWARD_CLIENT_MASK) #define FORWARD_CLIENT_ATTR(s, a) \ (HAVE_FORWARDED_CLIENT_ATTR(s) ? \ (s)->xforward.a : (s)->a) #define FORWARD_ADDR(s) FORWARD_CLIENT_ATTR((s), rfc_addr) #define FORWARD_NAME(s) FORWARD_CLIENT_ATTR((s), name) #define FORWARD_NAMADDR(s) FORWARD_CLIENT_ATTR((s), namaddr) #define FORWARD_PROTO(s) FORWARD_CLIENT_ATTR((s), protocol) #define FORWARD_HELO(s) FORWARD_CLIENT_ATTR((s), helo_name) #define FORWARD_PORT(s) FORWARD_CLIENT_ATTR((s), port) /* * Mixing is not a problem with forwarded local message identifiers. */ #define HAVE_FORWARDED_IDENT(s) \ ((s)->xforward.ident != 0) #define FORWARD_IDENT(s) \ (HAVE_FORWARDED_IDENT(s) ? \ (s)->xforward.ident : (s)->queue_id) /* * Mixing is not a problem with forwarded address rewriting contexts. */ #define FORWARD_DOMAIN(s) \ (((s)->xforward.flags & SMTPD_STATE_XFORWARD_DOMAIN) ? \ (s)->xforward.domain : (s)->rewrite_context) extern void smtpd_xforward_init(SMTPD_STATE *); extern void smtpd_xforward_preset(SMTPD_STATE *); extern void smtpd_xforward_reset(SMTPD_STATE *); /* * Transparency: before mail is queued, do we check for unknown recipients, * do we allow address mapping, automatic bcc, header/body checks? */ extern int smtpd_input_transp_mask; /* * More Milter support. */ extern MILTERS *smtpd_milters; /* * Message size multiplication factor for free space check. */ extern double smtpd_space_multf; /* * header_from_format support. */ extern int smtpd_hfrom_format; /* 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 /* /* TLS support originally by: /* Lutz Jaenicke /* BTU Cottbus /* Allgemeine Elektrotechnik /* Universitaetsplatz 3-4 /* D-03044 Cottbus, Germany /*--*/