1 /* $NetBSD: smtpd.h,v 1.4 2022/10/08 16:12:49 christos Exp $ */ 2 3 /*++ 4 /* NAME 5 /* smtpd 3h 6 /* SUMMARY 7 /* smtp server 8 /* SYNOPSIS 9 /* include "smtpd.h" 10 /* DESCRIPTION 11 /* .nf 12 13 /* 14 * System library. 15 */ 16 #include <sys/time.h> 17 #include <unistd.h> 18 19 /* 20 * Utility library. 21 */ 22 #include <vstream.h> 23 #include <vstring.h> 24 #include <argv.h> 25 #include <myaddrinfo.h> 26 27 /* 28 * Global library. 29 */ 30 #include <mail_stream.h> 31 32 /* 33 * Postfix TLS library. 34 */ 35 #include <tls.h> 36 37 /* 38 * Milter library. 39 */ 40 #include <milter.h> 41 42 /* 43 * Variables that keep track of conversation state. There is only one SMTP 44 * conversation at a time, so the state variables can be made global. And 45 * some of this has to be global anyway, so that the run-time error handler 46 * can clean up in case of a fatal error deep down in some library routine. 47 */ 48 typedef struct SMTPD_DEFER { 49 int active; /* is this active */ 50 VSTRING *reason; /* reason for deferral */ 51 VSTRING *dsn; /* DSN detail */ 52 int code; /* SMTP reply code */ 53 int class; /* error notification class */ 54 } SMTPD_DEFER; 55 56 typedef struct { 57 int flags; /* XFORWARD server state */ 58 char *name; /* name for access control */ 59 char *addr; /* address for access control */ 60 char *port; /* port for logging */ 61 char *namaddr; /* name[address]:port */ 62 char *rfc_addr; /* address for RFC 2821 */ 63 char *protocol; /* email protocol */ 64 char *helo_name; /* helo/ehlo parameter */ 65 char *ident; /* local message identifier */ 66 char *domain; /* rewrite context */ 67 } SMTPD_XFORWARD_ATTR; 68 69 typedef struct { 70 int flags; /* see below */ 71 int err; /* cleanup server/queue file errors */ 72 VSTREAM *client; /* SMTP client handle */ 73 VSTRING *buffer; /* SMTP client buffer */ 74 VSTRING *addr_buf; /* internalized address buffer */ 75 char *service; /* for event rate control */ 76 struct timeval arrival_time; /* start of MAIL FROM transaction */ 77 char *name; /* verified client hostname */ 78 char *reverse_name; /* unverified client hostname */ 79 char *addr; /* client host address string */ 80 char *port; /* port for logging */ 81 char *namaddr; /* name[address]:port */ 82 char *rfc_addr; /* address for RFC 2821 */ 83 int addr_family; /* address family */ 84 char *dest_addr; /* Dovecot AUTH, Milter {daemon_addr} */ 85 char *dest_port; /* Milter {daemon_port} */ 86 struct sockaddr_storage sockaddr; /* binary client endpoint */ 87 SOCKADDR_SIZE sockaddr_len; /* binary client endpoint */ 88 struct sockaddr_storage dest_sockaddr; /* binary local endpoint */ 89 SOCKADDR_SIZE dest_sockaddr_len; /* binary local endpoint */ 90 int name_status; /* 2=ok 4=soft 5=hard 6=forged */ 91 int reverse_name_status; /* 2=ok 4=soft 5=hard */ 92 int conn_count; /* connections from this client */ 93 int conn_rate; /* connection rate for this client */ 94 int error_count; /* reset after DOT */ 95 int error_mask; /* client errors */ 96 int notify_mask; /* what to report to postmaster */ 97 char *helo_name; /* client HELO/EHLO argument */ 98 char *queue_id; /* from cleanup server/queue file */ 99 VSTREAM *cleanup; /* cleanup server/queue file handle */ 100 MAIL_STREAM *dest; /* another server/file handle */ 101 int rcpt_count; /* number of accepted recipients */ 102 char *access_denied; /* fixme */ 103 ARGV *history; /* protocol transcript */ 104 char *reason; /* cause of connection loss */ 105 char *sender; /* sender address */ 106 char *encoding; /* owned by mail_cmd() */ 107 char *verp_delims; /* owned by mail_cmd() */ 108 char *recipient; /* recipient address */ 109 char *etrn_name; /* client ETRN argument */ 110 char *protocol; /* SMTP or ESMTP */ 111 char *where; /* protocol stage */ 112 int recursion; /* Kellerspeicherpegelanzeiger */ 113 off_t msg_size; /* MAIL FROM message size */ 114 off_t act_size; /* END-OF-DATA message size */ 115 int junk_cmds; /* counter */ 116 int rcpt_overshoot; /* counter */ 117 char *rewrite_context; /* address rewriting context */ 118 119 /* 120 * SASL specific. 121 */ 122 #ifdef USE_SASL_AUTH 123 struct XSASL_SERVER *sasl_server; 124 VSTRING *sasl_reply; 125 char *sasl_mechanism_list; 126 char *sasl_method; 127 char *sasl_username; 128 char *sasl_sender; 129 #endif 130 131 /* 132 * Specific to smtpd access checks. 133 */ 134 int sender_rcptmap_checked; /* sender validated against maps */ 135 int recipient_rcptmap_checked; /* recipient validated against maps */ 136 int warn_if_reject; /* force reject into warning */ 137 SMTPD_DEFER defer_if_reject; /* force reject into deferral */ 138 SMTPD_DEFER defer_if_permit; /* force permit into deferral */ 139 int defer_if_permit_client; /* force permit into warning */ 140 int defer_if_permit_helo; /* force permit into warning */ 141 int defer_if_permit_sender; /* force permit into warning */ 142 int discard; /* discard message */ 143 char *saved_filter; /* postponed filter action */ 144 char *saved_redirect; /* postponed redirect action */ 145 ARGV *saved_bcc; /* postponed bcc action */ 146 int saved_flags; /* postponed hold/discard */ 147 #ifdef DELAY_ACTION 148 int saved_delay; /* postponed deferred delay */ 149 #endif 150 VSTRING *expand_buf; /* scratch space for $name expansion */ 151 ARGV *prepend; /* prepended headers */ 152 VSTRING *instance; /* policy query correlation */ 153 int seqno; /* policy query correlation */ 154 int ehlo_discard_mask; /* suppressed EHLO features */ 155 char *dsn_envid; /* temporary MAIL FROM state */ 156 int dsn_ret; /* temporary MAIL FROM state */ 157 VSTRING *dsn_buf; /* scratch space for xtext expansion */ 158 VSTRING *dsn_orcpt_buf; /* scratch space for ORCPT parsing */ 159 160 /* 161 * Pass-through proxy client. 162 */ 163 struct SMTPD_PROXY *proxy; 164 char *proxy_mail; /* owned by mail_cmd() */ 165 166 /* 167 * XFORWARD server state. 168 */ 169 SMTPD_XFORWARD_ATTR xforward; /* up-stream logging info */ 170 171 /* 172 * TLS related state. 173 */ 174 #ifdef USE_TLS 175 #ifdef USE_TLSPROXY 176 VSTREAM *tlsproxy; /* tlsproxy(8) temp. handle */ 177 #endif 178 TLS_SESS_STATE *tls_context; /* TLS session state */ 179 #endif 180 181 /* 182 * Milter support. 183 */ 184 const char **milter_argv; /* SMTP command vector */ 185 ssize_t milter_argc; /* SMTP command vector */ 186 const char *milter_reject_text; /* input to call-back from Milter */ 187 MILTERS *milters; /* Milter initialization status. */ 188 189 /* 190 * EHLO temporary space. 191 */ 192 VSTRING *ehlo_buf; 193 ARGV *ehlo_argv; 194 195 /* 196 * BDAT processing state. 197 */ 198 #define SMTPD_BDAT_STAT_NONE 0 /* not processing BDAT */ 199 #define SMTPD_BDAT_STAT_OK 1 /* accepting BDAT chunks */ 200 #define SMTPD_BDAT_STAT_ERROR 2 /* skipping BDAT chunks */ 201 int bdat_state; /* see above */ 202 VSTREAM *bdat_get_stream; /* memory stream from BDAT chunk */ 203 VSTRING *bdat_get_buffer; /* read from memory stream */ 204 int bdat_prev_rec_type; 205 } SMTPD_STATE; 206 207 #define SMTPD_FLAG_HANGUP (1<<0) /* 421/521 disconnect */ 208 #define SMTPD_FLAG_ILL_PIPELINING (1<<1) /* inappropriate pipelining */ 209 #define SMTPD_FLAG_AUTH_USED (1<<2) /* don't reuse SASL state */ 210 #define SMTPD_FLAG_SMTPUTF8 (1<<3) /* RFC 6531/2 transaction */ 211 #define SMTPD_FLAG_NEED_MILTER_ABORT (1<<4) /* undo milter_mail_event() */ 212 213 /* Security: don't reset SMTPD_FLAG_AUTH_USED. */ 214 #define SMTPD_MASK_MAIL_KEEP \ 215 ~(SMTPD_FLAG_SMTPUTF8) /* Fix 20140706 */ 216 217 #define SMTPD_STATE_XFORWARD_INIT (1<<0) /* xforward preset done */ 218 #define SMTPD_STATE_XFORWARD_NAME (1<<1) /* client name received */ 219 #define SMTPD_STATE_XFORWARD_ADDR (1<<2) /* client address received */ 220 #define SMTPD_STATE_XFORWARD_PROTO (1<<3) /* protocol received */ 221 #define SMTPD_STATE_XFORWARD_HELO (1<<4) /* client helo received */ 222 #define SMTPD_STATE_XFORWARD_IDENT (1<<5) /* message identifier */ 223 #define SMTPD_STATE_XFORWARD_DOMAIN (1<<6) /* address context */ 224 #define SMTPD_STATE_XFORWARD_PORT (1<<7) /* client port received */ 225 226 #define SMTPD_STATE_XFORWARD_CLIENT_MASK \ 227 (SMTPD_STATE_XFORWARD_NAME | SMTPD_STATE_XFORWARD_ADDR \ 228 | SMTPD_STATE_XFORWARD_PROTO | SMTPD_STATE_XFORWARD_HELO \ 229 | SMTPD_STATE_XFORWARD_PORT) 230 231 extern void smtpd_state_init(SMTPD_STATE *, VSTREAM *, const char *); 232 extern void smtpd_state_reset(SMTPD_STATE *); 233 234 /* 235 * Conversation stages. This is used for "lost connection after XXX" 236 * diagnostics. 237 */ 238 #define SMTPD_AFTER_CONNECT "CONNECT" 239 #define SMTPD_AFTER_DATA "DATA content" 240 #define SMTPD_AFTER_BDAT "BDAT content" 241 #define SMTPD_AFTER_EOM "END-OF-MESSAGE" 242 243 /* 244 * Other stages. These are sometimes used to change the way information is 245 * logged or what information will be available for access control. 246 */ 247 #define SMTPD_CMD_HELO "HELO" 248 #define SMTPD_CMD_EHLO "EHLO" 249 #define SMTPD_CMD_STARTTLS "STARTTLS" 250 #define SMTPD_CMD_AUTH "AUTH" 251 #define SMTPD_CMD_MAIL "MAIL" 252 #define SMTPD_CMD_RCPT "RCPT" 253 #define SMTPD_CMD_DATA "DATA" 254 #define SMTPD_CMD_BDAT "BDAT" 255 #define SMTPD_CMD_EOD SMTPD_AFTER_EOM /* XXX Was: END-OF-DATA */ 256 #define SMTPD_CMD_RSET "RSET" 257 #define SMTPD_CMD_NOOP "NOOP" 258 #define SMTPD_CMD_VRFY "VRFY" 259 #define SMTPD_CMD_ETRN "ETRN" 260 #define SMTPD_CMD_QUIT "QUIT" 261 #define SMTPD_CMD_XCLIENT "XCLIENT" 262 #define SMTPD_CMD_XFORWARD "XFORWARD" 263 #define SMTPD_CMD_UNKNOWN "UNKNOWN" 264 265 /* 266 * Representation of unknown and non-existent client information. Throughout 267 * Postfix, we use the "unknown" string value for unknown client information 268 * (e.g., unknown remote client hostname), and we use the empty string, null 269 * pointer or "no queue file record" for non-existent client information 270 * (e.g., no HELO command, or local submission). 271 * 272 * Inside the SMTP server, unknown real client attributes are represented by 273 * the string "unknown", and non-existent HELO is represented as a null 274 * pointer. The SMTP server uses this same representation internally for 275 * forwarded client attributes; the XFORWARD syntax makes no distinction 276 * between unknown (remote submission) and non-existent (local submission). 277 * 278 * The SMTP client sends forwarded client attributes only when upstream client 279 * attributes exist (i.e. remote submission). Thus, local submissions will 280 * appear to come from an SMTP-based content filter, which is acceptable. 281 * 282 * Known/unknown client attribute values use the SMTP server's internal 283 * representation in queue files, in queue manager delivery requests, and in 284 * delivery agent $name expansions. 285 * 286 * Non-existent attribute values are never present in queue files. Non-existent 287 * information is represented as empty strings in queue manager delivery 288 * requests and in delivery agent $name expansions. 289 */ 290 #define CLIENT_ATTR_UNKNOWN "unknown" 291 292 #define CLIENT_NAME_UNKNOWN CLIENT_ATTR_UNKNOWN 293 #define CLIENT_ADDR_UNKNOWN CLIENT_ATTR_UNKNOWN 294 #define CLIENT_PORT_UNKNOWN CLIENT_ATTR_UNKNOWN 295 #define CLIENT_NAMADDR_UNKNOWN CLIENT_ATTR_UNKNOWN 296 #define CLIENT_HELO_UNKNOWN 0 297 #define CLIENT_PROTO_UNKNOWN CLIENT_ATTR_UNKNOWN 298 #define CLIENT_IDENT_UNKNOWN 0 299 #define CLIENT_DOMAIN_UNKNOWN 0 300 #define CLIENT_LOGIN_UNKNOWN 0 301 302 #define SERVER_ATTR_UNKNOWN "unknown" 303 304 #define SERVER_ADDR_UNKNOWN SERVER_ATTR_UNKNOWN 305 #define SERVER_PORT_UNKNOWN SERVER_ATTR_UNKNOWN 306 307 #define IS_AVAIL_CLIENT_ATTR(v) ((v) && strcmp((v), CLIENT_ATTR_UNKNOWN)) 308 309 #define IS_AVAIL_CLIENT_NAME(v) IS_AVAIL_CLIENT_ATTR(v) 310 #define IS_AVAIL_CLIENT_ADDR(v) IS_AVAIL_CLIENT_ATTR(v) 311 #define IS_AVAIL_CLIENT_PORT(v) IS_AVAIL_CLIENT_ATTR(v) 312 #define IS_AVAIL_CLIENT_NAMADDR(v) IS_AVAIL_CLIENT_ATTR(v) 313 #define IS_AVAIL_CLIENT_HELO(v) ((v) != 0) 314 #define IS_AVAIL_CLIENT_PROTO(v) IS_AVAIL_CLIENT_ATTR(v) 315 #define IS_AVAIL_CLIENT_IDENT(v) ((v) != 0) 316 #define IS_AVAIL_CLIENT_DOMAIN(v) ((v) != 0) 317 318 /* 319 * If running in stand-alone mode, do not try to talk to Postfix daemons but 320 * write to queue file instead. 321 */ 322 #define SMTPD_STAND_ALONE_STREAM(stream) \ 323 (stream == VSTREAM_IN && getuid() != var_owner_uid) 324 325 #define SMTPD_STAND_ALONE(state) \ 326 (state->client == VSTREAM_IN && getuid() != var_owner_uid) 327 328 /* 329 * If running as proxy front-end, disable actions that require communication 330 * with the cleanup server. 331 */ 332 #define USE_SMTPD_PROXY(state) \ 333 (SMTPD_STAND_ALONE(state) == 0 && *var_smtpd_proxy_filt) 334 335 /* 336 * Are we in a MAIL transaction? 337 */ 338 #define SMTPD_IN_MAIL_TRANSACTION(state) ((state)->sender != 0) 339 340 /* 341 * Are we processing BDAT requests? 342 */ 343 #define SMTPD_PROCESSING_BDAT(state) \ 344 ((state)->bdat_state != SMTPD_BDAT_STAT_NONE) 345 346 /* 347 * SMTPD peer information lookup. 348 */ 349 extern void smtpd_peer_init(SMTPD_STATE *state); 350 extern void smtpd_peer_reset(SMTPD_STATE *state); 351 extern void smtpd_peer_from_default(SMTPD_STATE *); 352 extern int smtpd_peer_from_haproxy(SMTPD_STATE *); 353 354 #define SMTPD_PEER_CODE_OK 2 355 #define SMTPD_PEER_CODE_TEMP 4 356 #define SMTPD_PEER_CODE_PERM 5 357 #define SMTPD_PEER_CODE_FORGED 6 358 359 /* 360 * Construct name[addr] or name[addr]:port as appropriate 361 */ 362 #define SMTPD_BUILD_NAMADDRPORT(name, addr, port) \ 363 concatenate((name), "[", (addr), "]", \ 364 var_smtpd_client_port_log ? ":" : (char *) 0, \ 365 (port), (char *) 0) 366 367 /* 368 * Don't mix information from the current SMTP session with forwarded 369 * information from an up-stream session. 370 */ 371 #define HAVE_FORWARDED_CLIENT_ATTR(s) \ 372 ((s)->xforward.flags & SMTPD_STATE_XFORWARD_CLIENT_MASK) 373 374 #define FORWARD_CLIENT_ATTR(s, a) \ 375 (HAVE_FORWARDED_CLIENT_ATTR(s) ? \ 376 (s)->xforward.a : (s)->a) 377 378 #define FORWARD_ADDR(s) FORWARD_CLIENT_ATTR((s), rfc_addr) 379 #define FORWARD_NAME(s) FORWARD_CLIENT_ATTR((s), name) 380 #define FORWARD_NAMADDR(s) FORWARD_CLIENT_ATTR((s), namaddr) 381 #define FORWARD_PROTO(s) FORWARD_CLIENT_ATTR((s), protocol) 382 #define FORWARD_HELO(s) FORWARD_CLIENT_ATTR((s), helo_name) 383 #define FORWARD_PORT(s) FORWARD_CLIENT_ATTR((s), port) 384 385 /* 386 * Mixing is not a problem with forwarded local message identifiers. 387 */ 388 #define HAVE_FORWARDED_IDENT(s) \ 389 ((s)->xforward.ident != 0) 390 391 #define FORWARD_IDENT(s) \ 392 (HAVE_FORWARDED_IDENT(s) ? \ 393 (s)->xforward.ident : (s)->queue_id) 394 395 /* 396 * Mixing is not a problem with forwarded address rewriting contexts. 397 */ 398 #define FORWARD_DOMAIN(s) \ 399 (((s)->xforward.flags & SMTPD_STATE_XFORWARD_DOMAIN) ? \ 400 (s)->xforward.domain : (s)->rewrite_context) 401 402 extern void smtpd_xforward_init(SMTPD_STATE *); 403 extern void smtpd_xforward_preset(SMTPD_STATE *); 404 extern void smtpd_xforward_reset(SMTPD_STATE *); 405 406 /* 407 * Transparency: before mail is queued, do we check for unknown recipients, 408 * do we allow address mapping, automatic bcc, header/body checks? 409 */ 410 extern int smtpd_input_transp_mask; 411 412 /* 413 * More Milter support. 414 */ 415 extern MILTERS *smtpd_milters; 416 417 /* 418 * Message size multiplication factor for free space check. 419 */ 420 extern double smtpd_space_multf; 421 422 /* 423 * header_from_format support. 424 */ 425 extern int smtpd_hfrom_format; 426 427 /* LICENSE 428 /* .ad 429 /* .fi 430 /* The Secure Mailer license must be distributed with this software. 431 /* AUTHOR(S) 432 /* Wietse Venema 433 /* IBM T.J. Watson Research 434 /* P.O. Box 704 435 /* Yorktown Heights, NY 10598, USA 436 /* 437 /* Wietse Venema 438 /* Google, Inc. 439 /* 111 8th Avenue 440 /* New York, NY 10011, USA 441 /* 442 /* TLS support originally by: 443 /* Lutz Jaenicke 444 /* BTU Cottbus 445 /* Allgemeine Elektrotechnik 446 /* Universitaetsplatz 3-4 447 /* D-03044 Cottbus, Germany 448 /*--*/ 449