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Diffstat (limited to 'src/smtpd/smtpd.h')
| -rw-r--r-- | src/smtpd/smtpd.h | 440 |
1 files changed, 440 insertions, 0 deletions
diff --git a/src/smtpd/smtpd.h b/src/smtpd/smtpd.h new file mode 100644 index 0000000..0b1d87b --- /dev/null +++ b/src/smtpd/smtpd.h @@ -0,0 +1,440 @@ +/*++ +/* NAME +/* smtpd 3h +/* SUMMARY +/* smtp server +/* SYNOPSIS +/* include "smtpd.h" +/* DESCRIPTION +/* .nf + + /* + * System library. + */ +#include <sys/time.h> +#include <unistd.h> + + /* + * Utility library. + */ +#include <vstream.h> +#include <vstring.h> +#include <argv.h> +#include <myaddrinfo.h> + + /* + * Global library. + */ +#include <mail_stream.h> + + /* + * Postfix TLS library. + */ +#include <tls.h> + + /* + * Milter library. + */ +#include <milter.h> + + /* + * 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 int smtpd_peer_from_haproxy(SMTPD_STATE *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; + +/* 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 +/*--*/ |