1/*++ 2/* NAME 3/* smtpd 3h 4/* SUMMARY 5/* smtp server 6/* SYNOPSIS 7/* include "smtpd.h" 8/* DESCRIPTION 9/* .nf 10 11 /* 12 * System library. 13 */ 14#include <sys/time.h> 15#include <unistd.h> 16 17 /* 18 * Utility library. 19 */ 20#include <vstream.h> 21#include <vstring.h> 22#include <argv.h> 23#include <myaddrinfo.h> 24 25 /* 26 * Global library. 27 */ 28#include <mail_stream.h> 29 30 /* 31 * Postfix TLS library. 32 */ 33#include <tls.h> 34 35 /* 36 * Milter library. 37 */ 38#include <milter.h> 39 40 /* 41 * Variables that keep track of conversation state. There is only one SMTP 42 * conversation at a time, so the state variables can be made global. And 43 * some of this has to be global anyway, so that the run-time error handler 44 * can clean up in case of a fatal error deep down in some library routine. 45 */ 46typedef struct SMTPD_DEFER { 47 int active; /* is this active */ 48 VSTRING *reason; /* reason for deferral */ 49 VSTRING *dsn; /* DSN detail */ 50 int code; /* SMTP reply code */ 51 int class; /* error notification class */ 52} SMTPD_DEFER; 53 54typedef struct { 55 int flags; /* XFORWARD server state */ 56 char *name; /* name for access control */ 57 char *addr; /* address for access control */ 58 char *port; /* port for logging */ 59 char *namaddr; /* name[address]:port */ 60 char *rfc_addr; /* address for RFC 2821 */ 61 char *protocol; /* email protocol */ 62 char *helo_name; /* helo/ehlo parameter */ 63 char *ident; /* local message identifier */ 64 char *domain; /* rewrite context */ 65} SMTPD_XFORWARD_ATTR; 66 67typedef struct { 68 int flags; /* see below */ 69 int err; /* cleanup server/queue file errors */ 70 VSTREAM *client; /* SMTP client handle */ 71 VSTRING *buffer; /* SMTP client buffer */ 72 VSTRING *addr_buf; /* internalized address buffer */ 73 char *service; /* for event rate control */ 74 struct timeval arrival_time; /* start of MAIL FROM transaction */ 75 char *name; /* verified client hostname */ 76 char *reverse_name; /* unverified client hostname */ 77 char *addr; /* client host address string */ 78 char *port; /* port for logging */ 79 char *namaddr; /* name[address]:port */ 80 char *rfc_addr; /* address for RFC 2821 */ 81 int addr_family; /* address family */ 82 char *dest_addr; /* for Dovecot AUTH */ 83 struct sockaddr_storage sockaddr; /* binary client endpoint */ 84 SOCKADDR_SIZE sockaddr_len; /* binary client endpoint */ 85 int name_status; /* 2=ok 4=soft 5=hard 6=forged */ 86 int reverse_name_status; /* 2=ok 4=soft 5=hard */ 87 int conn_count; /* connections from this client */ 88 int conn_rate; /* connection rate for this client */ 89 int error_count; /* reset after DOT */ 90 int error_mask; /* client errors */ 91 int notify_mask; /* what to report to postmaster */ 92 char *helo_name; /* client HELO/EHLO argument */ 93 char *queue_id; /* from cleanup server/queue file */ 94 VSTREAM *cleanup; /* cleanup server/queue file handle */ 95 MAIL_STREAM *dest; /* another server/file handle */ 96 int rcpt_count; /* number of accepted recipients */ 97 char *access_denied; /* fixme */ 98 ARGV *history; /* protocol transcript */ 99 char *reason; /* cause of connection loss */ 100 char *sender; /* sender address */ 101 char *encoding; /* owned by mail_cmd() */ 102 char *verp_delims; /* owned by mail_cmd() */ 103 char *recipient; /* recipient address */ 104 char *etrn_name; /* client ETRN argument */ 105 char *protocol; /* SMTP or ESMTP */ 106 char *where; /* protocol stage */ 107 int recursion; /* Kellerspeicherpegelanzeiger */ 108 off_t msg_size; /* MAIL FROM message size */ 109 off_t act_size; /* END-OF-DATA message size */ 110 int junk_cmds; /* counter */ 111 int rcpt_overshoot; /* counter */ 112 char *rewrite_context; /* address rewriting context */ 113 114 /* 115 * SASL specific. 116 */ 117#ifdef USE_SASL_AUTH 118 struct XSASL_SERVER *sasl_server; 119 VSTRING *sasl_reply; 120 char *sasl_mechanism_list; 121 char *sasl_method; 122 char *sasl_username; 123 char *sasl_sender; 124#endif 125 126 /* 127 * Specific to smtpd access checks. 128 */ 129 int sender_rcptmap_checked; /* sender validated against maps */ 130 int recipient_rcptmap_checked; /* recipient validated against maps */ 131 int warn_if_reject; /* force reject into warning */ 132 SMTPD_DEFER defer_if_reject; /* force reject into deferral */ 133 SMTPD_DEFER defer_if_permit; /* force permit into deferral */ 134 int defer_if_permit_client; /* force permit into warning */ 135 int defer_if_permit_helo; /* force permit into warning */ 136 int defer_if_permit_sender; /* force permit into warning */ 137 int discard; /* discard message */ 138 char *saved_filter; /* postponed filter action */ 139 char *saved_redirect; /* postponed redirect action */ 140 char *saved_bcc; /* postponed bcc action */ 141 int saved_flags; /* postponed hold/discard */ 142#ifdef DELAY_ACTION 143 int saved_delay; /* postponed deferred delay */ 144#endif 145 VSTRING *expand_buf; /* scratch space for $name expansion */ 146 ARGV *prepend; /* prepended headers */ 147 VSTRING *instance; /* policy query correlation */ 148 int seqno; /* policy query correlation */ 149 int ehlo_discard_mask; /* suppressed EHLO features */ 150 char *dsn_envid; /* temporary MAIL FROM state */ 151 int dsn_ret; /* temporary MAIL FROM state */ 152 VSTRING *dsn_buf; /* scratch space for xtext expansion */ 153 VSTRING *dsn_orcpt_buf; /* scratch space for ORCPT parsing */ 154 155 /* 156 * Pass-through proxy client. 157 */ 158 struct SMTPD_PROXY *proxy; 159 char *proxy_mail; /* owned by mail_cmd() */ 160 161 /* 162 * XFORWARD server state. 163 */ 164 SMTPD_XFORWARD_ATTR xforward; /* up-stream logging info */ 165 166 /* 167 * TLS related state. 168 */ 169#ifdef USE_TLS 170#ifdef USE_TLSPROXY 171 VSTREAM *tlsproxy; /* tlsproxy(8) temp. handle */ 172#endif 173 TLS_SESS_STATE *tls_context; /* TLS session state */ 174#endif 175 176 /* 177 * Milter support. 178 */ 179 const char **milter_argv; /* SMTP command vector */ 180 ssize_t milter_argc; /* SMTP command vector */ 181 const char *milter_reject_text; /* input to call-back from Milter */ 182 183 /* 184 * EHLO temporary space. 185 */ 186 VSTRING *ehlo_buf; 187 ARGV *ehlo_argv; 188} SMTPD_STATE; 189 190#define SMTPD_FLAG_HANGUP (1<<0) /* 421/521 disconnect */ 191#define SMTPD_FLAG_ILL_PIPELINING (1<<1) /* inappropriate pipelining */ 192#define SMTPD_FLAG_AUTH_USED (1<<2) /* don't reuse SASL state */ 193 194 /* Security: don't reset SMTPD_FLAG_AUTH_USED. */ 195#define SMTPD_MASK_MAIL_KEEP ~0 /* keep all after MAIL reset */ 196 197#define SMTPD_STATE_XFORWARD_INIT (1<<0) /* xforward preset done */ 198#define SMTPD_STATE_XFORWARD_NAME (1<<1) /* client name received */ 199#define SMTPD_STATE_XFORWARD_ADDR (1<<2) /* client address received */ 200#define SMTPD_STATE_XFORWARD_PROTO (1<<3) /* protocol received */ 201#define SMTPD_STATE_XFORWARD_HELO (1<<4) /* client helo received */ 202#define SMTPD_STATE_XFORWARD_IDENT (1<<5) /* message identifier */ 203#define SMTPD_STATE_XFORWARD_DOMAIN (1<<6) /* address context */ 204#define SMTPD_STATE_XFORWARD_PORT (1<<7) /* client port received */ 205 206#define SMTPD_STATE_XFORWARD_CLIENT_MASK \ 207 (SMTPD_STATE_XFORWARD_NAME | SMTPD_STATE_XFORWARD_ADDR \ 208 | SMTPD_STATE_XFORWARD_PROTO | SMTPD_STATE_XFORWARD_HELO \ 209 | SMTPD_STATE_XFORWARD_PORT) 210 211extern void smtpd_state_init(SMTPD_STATE *, VSTREAM *, const char *); 212extern void smtpd_state_reset(SMTPD_STATE *); 213 214 /* 215 * Conversation stages. This is used for "lost connection after XXX" 216 * diagnostics. 217 */ 218#define SMTPD_AFTER_CONNECT "CONNECT" 219#define SMTPD_AFTER_DATA "DATA content" 220#define SMTPD_AFTER_DOT "END-OF-MESSAGE" 221 222 /* 223 * Other stages. These are sometimes used to change the way information is 224 * logged or what information will be available for access control. 225 */ 226#define SMTPD_CMD_HELO "HELO" 227#define SMTPD_CMD_EHLO "EHLO" 228#define SMTPD_CMD_STARTTLS "STARTTLS" 229#define SMTPD_CMD_AUTH "AUTH" 230#define SMTPD_CMD_MAIL "MAIL" 231#define SMTPD_CMD_RCPT "RCPT" 232#define SMTPD_CMD_DATA "DATA" 233#define SMTPD_CMD_EOD SMTPD_AFTER_DOT /* XXX Was: END-OF-DATA */ 234#define SMTPD_CMD_RSET "RSET" 235#define SMTPD_CMD_NOOP "NOOP" 236#define SMTPD_CMD_VRFY "VRFY" 237#define SMTPD_CMD_ETRN "ETRN" 238#define SMTPD_CMD_QUIT "QUIT" 239#define SMTPD_CMD_XCLIENT "XCLIENT" 240#define SMTPD_CMD_XFORWARD "XFORWARD" 241#define SMTPD_CMD_UNKNOWN "UNKNOWN" 242 243 /* 244 * Representation of unknown and non-existent client information. Throughout 245 * Postfix, we use the "unknown" string value for unknown client information 246 * (e.g., unknown remote client hostname), and we use the empty string, null 247 * pointer or "no queue file record" for non-existent client information 248 * (e.g., no HELO command, or local submission). 249 * 250 * Inside the SMTP server, unknown real client attributes are represented by 251 * the string "unknown", and non-existent HELO is represented as a null 252 * pointer. The SMTP server uses this same representation internally for 253 * forwarded client attributes; the XFORWARD syntax makes no distinction 254 * between unknown (remote submission) and non-existent (local submission). 255 * 256 * The SMTP client sends forwarded client attributes only when upstream client 257 * attributes exist (i.e. remote submission). Thus, local submissions will 258 * appear to come from an SMTP-based content filter, which is acceptable. 259 * 260 * Known/unknown client attribute values use the SMTP server's internal 261 * representation in queue files, in queue manager delivery requests, and in 262 * delivery agent $name expansions. 263 * 264 * Non-existent attribute values are never present in queue files. Non-existent 265 * information is represented as empty strings in queue manager delivery 266 * requests and in delivery agent $name expansions. 267 */ 268#define CLIENT_ATTR_UNKNOWN "unknown" 269 270#define CLIENT_NAME_UNKNOWN CLIENT_ATTR_UNKNOWN 271#define CLIENT_ADDR_UNKNOWN CLIENT_ATTR_UNKNOWN 272#define CLIENT_PORT_UNKNOWN CLIENT_ATTR_UNKNOWN 273#define CLIENT_NAMADDR_UNKNOWN CLIENT_ATTR_UNKNOWN 274#define CLIENT_HELO_UNKNOWN 0 275#define CLIENT_PROTO_UNKNOWN CLIENT_ATTR_UNKNOWN 276#define CLIENT_IDENT_UNKNOWN 0 277#define CLIENT_DOMAIN_UNKNOWN 0 278#define CLIENT_LOGIN_UNKNOWN 0 279 280#define IS_AVAIL_CLIENT_ATTR(v) ((v) && strcmp((v), CLIENT_ATTR_UNKNOWN)) 281 282#define IS_AVAIL_CLIENT_NAME(v) IS_AVAIL_CLIENT_ATTR(v) 283#define IS_AVAIL_CLIENT_ADDR(v) IS_AVAIL_CLIENT_ATTR(v) 284#define IS_AVAIL_CLIENT_PORT(v) IS_AVAIL_CLIENT_ATTR(v) 285#define IS_AVAIL_CLIENT_NAMADDR(v) IS_AVAIL_CLIENT_ATTR(v) 286#define IS_AVAIL_CLIENT_HELO(v) ((v) != 0) 287#define IS_AVAIL_CLIENT_PROTO(v) IS_AVAIL_CLIENT_ATTR(v) 288#define IS_AVAIL_CLIENT_IDENT(v) ((v) != 0) 289#define IS_AVAIL_CLIENT_DOMAIN(v) ((v) != 0) 290 291 /* 292 * If running in stand-alone mode, do not try to talk to Postfix daemons but 293 * write to queue file instead. 294 */ 295#define SMTPD_STAND_ALONE_STREAM(stream) \ 296 (stream == VSTREAM_IN && getuid() != var_owner_uid) 297 298#define SMTPD_STAND_ALONE(state) \ 299 (state->client == VSTREAM_IN && getuid() != var_owner_uid) 300 301 /* 302 * If running as proxy front-end, disable actions that require communication 303 * with the cleanup server. 304 */ 305#define USE_SMTPD_PROXY(state) \ 306 (SMTPD_STAND_ALONE(state) == 0 && *var_smtpd_proxy_filt) 307 308 /* 309 * Are we in a MAIL transaction? 310 */ 311#define SMTPD_IN_MAIL_TRANSACTION(state) ((state)->sender != 0) 312 313 /* 314 * SMTPD peer information lookup. 315 */ 316extern void smtpd_peer_init(SMTPD_STATE *state); 317extern void smtpd_peer_reset(SMTPD_STATE *state); 318extern int smtpd_peer_from_haproxy(SMTPD_STATE *state); 319 320#define SMTPD_PEER_CODE_OK 2 321#define SMTPD_PEER_CODE_TEMP 4 322#define SMTPD_PEER_CODE_PERM 5 323#define SMTPD_PEER_CODE_FORGED 6 324 325 /* 326 * Construct name[addr] or name[addr]:port as appropriate 327 */ 328#define SMTPD_BUILD_NAMADDRPORT(name, addr, port) \ 329 concatenate((name), "[", (addr), "]", \ 330 var_smtpd_client_port_log ? ":" : (char *) 0, \ 331 (port), (char *) 0) 332 333 /* 334 * Don't mix information from the current SMTP session with forwarded 335 * information from an up-stream session. 336 */ 337#define HAVE_FORWARDED_CLIENT_ATTR(s) \ 338 ((s)->xforward.flags & SMTPD_STATE_XFORWARD_CLIENT_MASK) 339 340#define FORWARD_CLIENT_ATTR(s, a) \ 341 (HAVE_FORWARDED_CLIENT_ATTR(s) ? \ 342 (s)->xforward.a : (s)->a) 343 344#define FORWARD_ADDR(s) FORWARD_CLIENT_ATTR((s), rfc_addr) 345#define FORWARD_NAME(s) FORWARD_CLIENT_ATTR((s), name) 346#define FORWARD_NAMADDR(s) FORWARD_CLIENT_ATTR((s), namaddr) 347#define FORWARD_PROTO(s) FORWARD_CLIENT_ATTR((s), protocol) 348#define FORWARD_HELO(s) FORWARD_CLIENT_ATTR((s), helo_name) 349#define FORWARD_PORT(s) FORWARD_CLIENT_ATTR((s), port) 350 351 /* 352 * Mixing is not a problem with forwarded local message identifiers. 353 */ 354#define HAVE_FORWARDED_IDENT(s) \ 355 ((s)->xforward.ident != 0) 356 357#define FORWARD_IDENT(s) \ 358 (HAVE_FORWARDED_IDENT(s) ? \ 359 (s)->xforward.ident : (s)->queue_id) 360 361 /* 362 * Mixing is not a problem with forwarded address rewriting contexts. 363 */ 364#define FORWARD_DOMAIN(s) \ 365 (((s)->xforward.flags & SMTPD_STATE_XFORWARD_DOMAIN) ? \ 366 (s)->xforward.domain : (s)->rewrite_context) 367 368extern void smtpd_xforward_init(SMTPD_STATE *); 369extern void smtpd_xforward_preset(SMTPD_STATE *); 370extern void smtpd_xforward_reset(SMTPD_STATE *); 371 372 /* 373 * Transparency: before mail is queued, do we check for unknown recipients, 374 * do we allow address mapping, automatic bcc, header/body checks? 375 */ 376extern int smtpd_input_transp_mask; 377 378 /* 379 * More Milter support. 380 */ 381extern MILTERS *smtpd_milters; 382 383 /* 384 * Message size multiplication factor for free space check. 385 */ 386extern double smtpd_space_multf; 387 388/* LICENSE 389/* .ad 390/* .fi 391/* The Secure Mailer license must be distributed with this software. 392/* AUTHOR(S) 393/* Wietse Venema 394/* IBM T.J. Watson Research 395/* P.O. Box 704 396/* Yorktown Heights, NY 10598, USA 397/* 398/* TLS support originally by: 399/* Lutz Jaenicke 400/* BTU Cottbus 401/* Allgemeine Elektrotechnik 402/* Universitaetsplatz 3-4 403/* D-03044 Cottbus, Germany 404/*--*/ 405