1 /* $NetBSD: smtpd.h,v 1.5 2023/12/23 20:30:45 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 *anvil_range; /* client address or network/length */ 83 char *rfc_addr; /* address for RFC 2821 */ 84 int addr_family; /* address family */ 85 char *dest_addr; /* Dovecot AUTH, Milter {daemon_addr} */ 86 char *dest_port; /* Milter {daemon_port} */ 87 struct sockaddr_storage sockaddr; /* binary client endpoint */ 88 SOCKADDR_SIZE sockaddr_len; /* binary client endpoint */ 89 struct sockaddr_storage dest_sockaddr; /* binary local endpoint */ 90 SOCKADDR_SIZE dest_sockaddr_len; /* binary local endpoint */ 91 int name_status; /* 2=ok 4=soft 5=hard 6=forged */ 92 int reverse_name_status; /* 2=ok 4=soft 5=hard */ 93 int conn_count; /* connections from this client */ 94 int conn_rate; /* connection rate for this client */ 95 int error_count; /* reset after DOT */ 96 int error_mask; /* client errors */ 97 int notify_mask; /* what to report to postmaster */ 98 char *helo_name; /* client HELO/EHLO argument */ 99 char *queue_id; /* from cleanup server/queue file */ 100 VSTREAM *cleanup; /* cleanup server/queue file handle */ 101 MAIL_STREAM *dest; /* another server/file handle */ 102 int rcpt_count; /* number of accepted recipients */ 103 char *access_denied; /* fixme */ 104 ARGV *history; /* protocol transcript */ 105 char *reason; /* cause of connection loss */ 106 char *sender; /* sender address */ 107 char *encoding; /* owned by mail_cmd() */ 108 char *verp_delims; /* owned by mail_cmd() */ 109 char *recipient; /* recipient address */ 110 char *etrn_name; /* client ETRN argument */ 111 char *protocol; /* SMTP or ESMTP */ 112 char *where; /* protocol stage */ 113 int recursion; /* Kellerspeicherpegelanzeiger */ 114 off_t msg_size; /* MAIL FROM message size */ 115 off_t act_size; /* END-OF-DATA message size */ 116 int junk_cmds; /* counter */ 117 int rcpt_overshoot; /* counter */ 118 char *rewrite_context; /* address rewriting context */ 119 120 /* 121 * SASL specific. 122 */ 123 #ifdef USE_SASL_AUTH 124 struct XSASL_SERVER *sasl_server; 125 VSTRING *sasl_reply; 126 char *sasl_mechanism_list; 127 char *sasl_method; 128 char *sasl_username; 129 char *sasl_sender; 130 #endif 131 132 /* 133 * Specific to smtpd access checks. 134 */ 135 int sender_rcptmap_checked; /* sender validated against maps */ 136 int recipient_rcptmap_checked; /* recipient validated against maps */ 137 int warn_if_reject; /* force reject into warning */ 138 SMTPD_DEFER defer_if_reject; /* force reject into deferral */ 139 SMTPD_DEFER defer_if_permit; /* force permit into deferral */ 140 int defer_if_permit_client; /* force permit into warning */ 141 int defer_if_permit_helo; /* force permit into warning */ 142 int defer_if_permit_sender; /* force permit into warning */ 143 int discard; /* discard message */ 144 char *saved_filter; /* postponed filter action */ 145 char *saved_redirect; /* postponed redirect action */ 146 ARGV *saved_bcc; /* postponed bcc action */ 147 int saved_flags; /* postponed hold/discard */ 148 #ifdef DELAY_ACTION 149 int saved_delay; /* postponed deferred delay */ 150 #endif 151 VSTRING *expand_buf; /* scratch space for $name expansion */ 152 ARGV *prepend; /* prepended headers */ 153 VSTRING *instance; /* policy query correlation */ 154 int seqno; /* policy query correlation */ 155 int ehlo_discard_mask; /* suppressed EHLO features */ 156 char *dsn_envid; /* temporary MAIL FROM state */ 157 int dsn_ret; /* temporary MAIL FROM state */ 158 VSTRING *dsn_buf; /* scratch space for xtext expansion */ 159 VSTRING *dsn_orcpt_buf; /* scratch space for ORCPT parsing */ 160 161 /* 162 * Pass-through proxy client. 163 */ 164 struct SMTPD_PROXY *proxy; 165 char *proxy_mail; /* owned by mail_cmd() */ 166 167 /* 168 * XFORWARD server state. 169 */ 170 SMTPD_XFORWARD_ATTR xforward; /* up-stream logging info */ 171 172 /* 173 * TLS related state. 174 */ 175 #ifdef USE_TLS 176 #ifdef USE_TLSPROXY 177 VSTREAM *tlsproxy; /* tlsproxy(8) temp. handle */ 178 #endif 179 TLS_SESS_STATE *tls_context; /* TLS session state */ 180 #endif 181 182 /* 183 * Milter support. 184 */ 185 const char **milter_argv; /* SMTP command vector */ 186 ssize_t milter_argc; /* SMTP command vector */ 187 const char *milter_reject_text; /* input to call-back from Milter */ 188 MILTERS *milters; /* Milter initialization status. */ 189 190 /* 191 * EHLO temporary space. 192 */ 193 VSTRING *ehlo_buf; 194 ARGV *ehlo_argv; 195 196 /* 197 * BDAT processing state. 198 */ 199 #define SMTPD_BDAT_STAT_NONE 0 /* not processing BDAT */ 200 #define SMTPD_BDAT_STAT_OK 1 /* accepting BDAT chunks */ 201 #define SMTPD_BDAT_STAT_ERROR 2 /* skipping BDAT chunks */ 202 int bdat_state; /* see above */ 203 VSTREAM *bdat_get_stream; /* memory stream from BDAT chunk */ 204 VSTRING *bdat_get_buffer; /* read from memory stream */ 205 int bdat_prev_rec_type; 206 } SMTPD_STATE; 207 208 #define SMTPD_FLAG_HANGUP (1<<0) /* 421/521 disconnect */ 209 #define SMTPD_FLAG_ILL_PIPELINING (1<<1) /* inappropriate pipelining */ 210 #define SMTPD_FLAG_AUTH_USED (1<<2) /* don't reuse SASL state */ 211 #define SMTPD_FLAG_SMTPUTF8 (1<<3) /* RFC 6531/2 transaction */ 212 #define SMTPD_FLAG_NEED_MILTER_ABORT (1<<4) /* undo milter_mail_event() */ 213 214 /* Security: don't reset SMTPD_FLAG_AUTH_USED. */ 215 #define SMTPD_MASK_MAIL_KEEP \ 216 ~(SMTPD_FLAG_SMTPUTF8) /* Fix 20140706 */ 217 218 #define SMTPD_STATE_XFORWARD_INIT (1<<0) /* xforward preset done */ 219 #define SMTPD_STATE_XFORWARD_NAME (1<<1) /* client name received */ 220 #define SMTPD_STATE_XFORWARD_ADDR (1<<2) /* client address received */ 221 #define SMTPD_STATE_XFORWARD_PROTO (1<<3) /* protocol received */ 222 #define SMTPD_STATE_XFORWARD_HELO (1<<4) /* client helo received */ 223 #define SMTPD_STATE_XFORWARD_IDENT (1<<5) /* message identifier */ 224 #define SMTPD_STATE_XFORWARD_DOMAIN (1<<6) /* address context */ 225 #define SMTPD_STATE_XFORWARD_PORT (1<<7) /* client port received */ 226 227 #define SMTPD_STATE_XFORWARD_CLIENT_MASK \ 228 (SMTPD_STATE_XFORWARD_NAME | SMTPD_STATE_XFORWARD_ADDR \ 229 | SMTPD_STATE_XFORWARD_PROTO | SMTPD_STATE_XFORWARD_HELO \ 230 | SMTPD_STATE_XFORWARD_PORT) 231 232 extern void smtpd_state_init(SMTPD_STATE *, VSTREAM *, const char *); 233 extern void smtpd_state_reset(SMTPD_STATE *); 234 235 /* 236 * Conversation stages. This is used for "lost connection after XXX" 237 * diagnostics. 238 */ 239 #define SMTPD_AFTER_CONNECT "CONNECT" 240 #define SMTPD_AFTER_DATA "DATA content" 241 #define SMTPD_AFTER_BDAT "BDAT content" 242 #define SMTPD_AFTER_EOM "END-OF-MESSAGE" 243 244 /* 245 * Other stages. These are sometimes used to change the way information is 246 * logged or what information will be available for access control. 247 */ 248 #define SMTPD_CMD_HELO "HELO" 249 #define SMTPD_CMD_EHLO "EHLO" 250 #define SMTPD_CMD_STARTTLS "STARTTLS" 251 #define SMTPD_CMD_AUTH "AUTH" 252 #define SMTPD_CMD_MAIL "MAIL" 253 #define SMTPD_CMD_RCPT "RCPT" 254 #define SMTPD_CMD_DATA "DATA" 255 #define SMTPD_CMD_BDAT "BDAT" 256 #define SMTPD_CMD_EOD SMTPD_AFTER_EOM /* XXX Was: END-OF-DATA */ 257 #define SMTPD_CMD_RSET "RSET" 258 #define SMTPD_CMD_NOOP "NOOP" 259 #define SMTPD_CMD_VRFY "VRFY" 260 #define SMTPD_CMD_ETRN "ETRN" 261 #define SMTPD_CMD_QUIT "QUIT" 262 #define SMTPD_CMD_XCLIENT "XCLIENT" 263 #define SMTPD_CMD_XFORWARD "XFORWARD" 264 #define SMTPD_CMD_UNKNOWN "UNKNOWN" 265 266 /* 267 * Representation of unknown and non-existent client information. Throughout 268 * Postfix, we use the "unknown" string value for unknown client information 269 * (e.g., unknown remote client hostname), and we use the empty string, null 270 * pointer or "no queue file record" for non-existent client information 271 * (e.g., no HELO command, or local submission). 272 * 273 * Inside the SMTP server, unknown real client attributes are represented by 274 * the string "unknown", and non-existent HELO is represented as a null 275 * pointer. The SMTP server uses this same representation internally for 276 * forwarded client attributes; the XFORWARD syntax makes no distinction 277 * between unknown (remote submission) and non-existent (local submission). 278 * 279 * The SMTP client sends forwarded client attributes only when upstream client 280 * attributes exist (i.e. remote submission). Thus, local submissions will 281 * appear to come from an SMTP-based content filter, which is acceptable. 282 * 283 * Known/unknown client attribute values use the SMTP server's internal 284 * representation in queue files, in queue manager delivery requests, and in 285 * delivery agent $name expansions. 286 * 287 * Non-existent attribute values are never present in queue files. Non-existent 288 * information is represented as empty strings in queue manager delivery 289 * requests and in delivery agent $name expansions. 290 */ 291 #define CLIENT_ATTR_UNKNOWN "unknown" 292 293 #define CLIENT_NAME_UNKNOWN CLIENT_ATTR_UNKNOWN 294 #define CLIENT_ADDR_UNKNOWN CLIENT_ATTR_UNKNOWN 295 #define CLIENT_PORT_UNKNOWN CLIENT_ATTR_UNKNOWN 296 #define CLIENT_NAMADDR_UNKNOWN CLIENT_ATTR_UNKNOWN 297 #define CLIENT_HELO_UNKNOWN 0 298 #define CLIENT_PROTO_UNKNOWN CLIENT_ATTR_UNKNOWN 299 #define CLIENT_IDENT_UNKNOWN 0 300 #define CLIENT_DOMAIN_UNKNOWN 0 301 #define CLIENT_LOGIN_UNKNOWN 0 302 303 #define SERVER_ATTR_UNKNOWN "unknown" 304 305 #define SERVER_ADDR_UNKNOWN SERVER_ATTR_UNKNOWN 306 #define SERVER_PORT_UNKNOWN SERVER_ATTR_UNKNOWN 307 308 #define IS_AVAIL_CLIENT_ATTR(v) ((v) && strcmp((v), CLIENT_ATTR_UNKNOWN)) 309 310 #define IS_AVAIL_CLIENT_NAME(v) IS_AVAIL_CLIENT_ATTR(v) 311 #define IS_AVAIL_CLIENT_ADDR(v) IS_AVAIL_CLIENT_ATTR(v) 312 #define IS_AVAIL_CLIENT_PORT(v) IS_AVAIL_CLIENT_ATTR(v) 313 #define IS_AVAIL_CLIENT_NAMADDR(v) IS_AVAIL_CLIENT_ATTR(v) 314 #define IS_AVAIL_CLIENT_HELO(v) ((v) != 0) 315 #define IS_AVAIL_CLIENT_PROTO(v) IS_AVAIL_CLIENT_ATTR(v) 316 #define IS_AVAIL_CLIENT_IDENT(v) ((v) != 0) 317 #define IS_AVAIL_CLIENT_DOMAIN(v) ((v) != 0) 318 319 /* 320 * If running in stand-alone mode, do not try to talk to Postfix daemons but 321 * write to queue file instead. 322 */ 323 #define SMTPD_STAND_ALONE_STREAM(stream) \ 324 (stream == VSTREAM_IN && getuid() != var_owner_uid) 325 326 #define SMTPD_STAND_ALONE(state) \ 327 (state->client == VSTREAM_IN && getuid() != var_owner_uid) 328 329 /* 330 * If running as proxy front-end, disable actions that require communication 331 * with the cleanup server. 332 */ 333 #define USE_SMTPD_PROXY(state) \ 334 (SMTPD_STAND_ALONE(state) == 0 && *var_smtpd_proxy_filt) 335 336 /* 337 * Are we in a MAIL transaction? 338 */ 339 #define SMTPD_IN_MAIL_TRANSACTION(state) ((state)->sender != 0) 340 341 /* 342 * Are we processing BDAT requests? 343 */ 344 #define SMTPD_PROCESSING_BDAT(state) \ 345 ((state)->bdat_state != SMTPD_BDAT_STAT_NONE) 346 347 /* 348 * SMTPD peer information lookup. 349 */ 350 extern void smtpd_peer_init(SMTPD_STATE *state); 351 extern void smtpd_peer_reset(SMTPD_STATE *state); 352 extern void smtpd_peer_from_default(SMTPD_STATE *); 353 extern int smtpd_peer_from_haproxy(SMTPD_STATE *); 354 355 #define SMTPD_PEER_CODE_OK 2 356 #define SMTPD_PEER_CODE_TEMP 4 357 #define SMTPD_PEER_CODE_PERM 5 358 #define SMTPD_PEER_CODE_FORGED 6 359 360 /* 361 * Construct name[addr] or name[addr]:port as appropriate 362 */ 363 #define SMTPD_BUILD_NAMADDRPORT(name, addr, port) \ 364 concatenate((name), "[", (addr), "]", \ 365 var_smtpd_client_port_log ? ":" : (char *) 0, \ 366 (port), (char *) 0) 367 368 /* 369 * Don't mix information from the current SMTP session with forwarded 370 * information from an up-stream session. 371 */ 372 #define HAVE_FORWARDED_CLIENT_ATTR(s) \ 373 ((s)->xforward.flags & SMTPD_STATE_XFORWARD_CLIENT_MASK) 374 375 #define FORWARD_CLIENT_ATTR(s, a) \ 376 (HAVE_FORWARDED_CLIENT_ATTR(s) ? \ 377 (s)->xforward.a : (s)->a) 378 379 #define FORWARD_ADDR(s) FORWARD_CLIENT_ATTR((s), rfc_addr) 380 #define FORWARD_NAME(s) FORWARD_CLIENT_ATTR((s), name) 381 #define FORWARD_NAMADDR(s) FORWARD_CLIENT_ATTR((s), namaddr) 382 #define FORWARD_PROTO(s) FORWARD_CLIENT_ATTR((s), protocol) 383 #define FORWARD_HELO(s) FORWARD_CLIENT_ATTR((s), helo_name) 384 #define FORWARD_PORT(s) FORWARD_CLIENT_ATTR((s), port) 385 386 /* 387 * Mixing is not a problem with forwarded local message identifiers. 388 */ 389 #define HAVE_FORWARDED_IDENT(s) \ 390 ((s)->xforward.ident != 0) 391 392 #define FORWARD_IDENT(s) \ 393 (HAVE_FORWARDED_IDENT(s) ? \ 394 (s)->xforward.ident : (s)->queue_id) 395 396 /* 397 * Mixing is not a problem with forwarded address rewriting contexts. 398 */ 399 #define FORWARD_DOMAIN(s) \ 400 (((s)->xforward.flags & SMTPD_STATE_XFORWARD_DOMAIN) ? \ 401 (s)->xforward.domain : (s)->rewrite_context) 402 403 extern void smtpd_xforward_init(SMTPD_STATE *); 404 extern void smtpd_xforward_preset(SMTPD_STATE *); 405 extern void smtpd_xforward_reset(SMTPD_STATE *); 406 407 /* 408 * Transparency: before mail is queued, do we check for unknown recipients, 409 * do we allow address mapping, automatic bcc, header/body checks? 410 */ 411 extern int smtpd_input_transp_mask; 412 413 /* 414 * More Milter support. 415 */ 416 extern MILTERS *smtpd_milters; 417 418 /* 419 * Message size multiplication factor for free space check. 420 */ 421 extern double smtpd_space_multf; 422 423 /* 424 * header_from_format support. 425 */ 426 extern int smtpd_hfrom_format; 427 428 /* LICENSE 429 /* .ad 430 /* .fi 431 /* The Secure Mailer license must be distributed with this software. 432 /* AUTHOR(S) 433 /* Wietse Venema 434 /* IBM T.J. Watson Research 435 /* P.O. Box 704 436 /* Yorktown Heights, NY 10598, USA 437 /* 438 /* Wietse Venema 439 /* Google, Inc. 440 /* 111 8th Avenue 441 /* New York, NY 10011, USA 442 /* 443 /* TLS support originally by: 444 /* Lutz Jaenicke 445 /* BTU Cottbus 446 /* Allgemeine Elektrotechnik 447 /* Universitaetsplatz 3-4 448 /* D-03044 Cottbus, Germany 449 /*--*/ 450