1 /* $NetBSD: deliver_request.c,v 1.3 2022/10/08 16:12:45 christos Exp $ */ 2 3 /*++ 4 /* NAME 5 /* deliver_request 3 6 /* SUMMARY 7 /* mail delivery request protocol, server side 8 /* SYNOPSIS 9 /* #include <deliver_request.h> 10 /* 11 /* typedef struct DELIVER_REQUEST { 12 /* .in +5 13 /* VSTREAM *fp; 14 /* int flags; 15 /* char *queue_name; 16 /* char *queue_id; 17 /* long data_offset; 18 /* long data_size; 19 /* char *nexthop; 20 /* char *encoding; 21 /* char *sender; 22 /* MSG_STATS msg_stats; 23 /* RECIPIENT_LIST rcpt_list; 24 /* DSN *hop_status; 25 /* char *client_name; 26 /* char *client_addr; 27 /* char *client_port; 28 /* char *client_proto; 29 /* char *client_helo; 30 /* char *sasl_method; 31 /* char *sasl_username; 32 /* char *sasl_sender; 33 /* char *log_ident; 34 /* char *rewrite_context; 35 /* char *dsn_envid; 36 /* int dsn_ret; 37 /* .in -5 38 /* } DELIVER_REQUEST; 39 /* 40 /* DELIVER_REQUEST *deliver_request_read(stream) 41 /* VSTREAM *stream; 42 /* 43 /* void deliver_request_done(stream, request, status) 44 /* VSTREAM *stream; 45 /* DELIVER_REQUEST *request; 46 /* int status; 47 /* DESCRIPTION 48 /* This module implements the delivery agent side of the `queue manager 49 /* to delivery agent' protocol. In this game, the queue manager is 50 /* the client, while the delivery agent is the server. 51 /* 52 /* deliver_request_read() reads a client message delivery request, 53 /* opens the queue file, and acquires a shared lock. 54 /* A null result means that the client sent bad information or that 55 /* it went away unexpectedly. 56 /* 57 /* The \fBflags\fR structure member is the bit-wise OR of zero or more 58 /* of the following: 59 /* .IP \fBDEL_REQ_FLAG_SUCCESS\fR 60 /* Delete successful recipients from the queue file. 61 /* 62 /* Note: currently, this also controls whether bounced recipients 63 /* are deleted. 64 /* 65 /* Note: the deliver_completed() function ignores this request 66 /* when the recipient queue file offset is -1. 67 /* .IP \fBDEL_REQ_FLAG_BOUNCE\fR 68 /* Delete bounced recipients from the queue file. Currently, 69 /* this flag is non-functional. 70 /* .PP 71 /* The \fBDEL_REQ_FLAG_DEFLT\fR constant provides a convenient shorthand 72 /* for the most common case: delete successful and bounced recipients. 73 /* 74 /* The \fIhop_status\fR member must be updated by the caller 75 /* when all delivery to the destination in \fInexthop\fR should 76 /* be deferred. This member is passed to dsn_free(). 77 /* 78 /* deliver_request_done() reports the delivery status back to the 79 /* client, including the optional \fIhop_status\fR etc. information, 80 /* closes the queue file, 81 /* and destroys the DELIVER_REQUEST structure. The result is 82 /* non-zero when the status could not be reported to the client. 83 /* DIAGNOSTICS 84 /* Warnings: bad data sent by the client. Fatal errors: out of 85 /* memory, queue file open errors. 86 /* SEE ALSO 87 /* attr_scan(3) low-level intra-mail input routines 88 /* LICENSE 89 /* .ad 90 /* .fi 91 /* The Secure Mailer license must be distributed with this software. 92 /* AUTHOR(S) 93 /* Wietse Venema 94 /* IBM T.J. Watson Research 95 /* P.O. Box 704 96 /* Yorktown Heights, NY 10598, USA 97 /* 98 /* Wietse Venema 99 /* Google, Inc. 100 /* 111 8th Avenue 101 /* New York, NY 10011, USA 102 /*--*/ 103 104 /* System library. */ 105 106 #include <sys_defs.h> 107 #include <sys/stat.h> 108 #include <string.h> 109 #include <unistd.h> 110 #include <errno.h> 111 112 /* Utility library. */ 113 114 #include <msg.h> 115 #include <vstream.h> 116 #include <vstring.h> 117 #include <mymalloc.h> 118 #include <iostuff.h> 119 #include <myflock.h> 120 121 /* Global library. */ 122 123 #include "mail_queue.h" 124 #include "mail_proto.h" 125 #include "mail_open_ok.h" 126 #include "recipient_list.h" 127 #include "dsn.h" 128 #include "dsn_print.h" 129 #include "deliver_request.h" 130 #include "rcpt_buf.h" 131 132 /* deliver_request_initial - send initial status code */ 133 134 static int deliver_request_initial(VSTREAM *stream) 135 { 136 int err; 137 138 /* 139 * The master processes runs a finite number of delivery agent processes 140 * to handle service requests. Thus, a delivery agent process must send 141 * something to inform the queue manager that it is ready to receive a 142 * delivery request; otherwise the queue manager could block in write(). 143 */ 144 if (msg_verbose) 145 msg_info("deliver_request_initial: send initial response"); 146 attr_print(stream, ATTR_FLAG_NONE, 147 SEND_ATTR_STR(MAIL_ATTR_PROTO, MAIL_ATTR_PROTO_DELIVER), 148 ATTR_TYPE_END); 149 if ((err = vstream_fflush(stream)) != 0) 150 if (msg_verbose) 151 msg_warn("send initial response: %m"); 152 return (err); 153 } 154 155 /* deliver_request_final - send final delivery request status */ 156 157 static int deliver_request_final(VSTREAM *stream, DELIVER_REQUEST *request, 158 int status) 159 { 160 DSN *hop_status; 161 int err; 162 163 /* XXX This DSN structure initialization bypasses integrity checks. */ 164 static DSN dummy_dsn = {"", "", "", "", "", "", ""}; 165 166 /* 167 * Send the status and the optional reason. 168 */ 169 if ((hop_status = request->hop_status) == 0) 170 hop_status = &dummy_dsn; 171 if (msg_verbose) 172 msg_info("deliver_request_final: send: \"%s\" %d", 173 hop_status->reason, status); 174 attr_print(stream, ATTR_FLAG_NONE, 175 SEND_ATTR_FUNC(dsn_print, (const void *) hop_status), 176 SEND_ATTR_INT(MAIL_ATTR_STATUS, status), 177 ATTR_TYPE_END); 178 if ((err = vstream_fflush(stream)) != 0) 179 if (msg_verbose) 180 msg_warn("send final status: %m"); 181 182 /* 183 * With some UNIX systems, stream sockets lose data when you close them 184 * immediately after writing to them. That is not how sockets are 185 * supposed to behave! The workaround is to wait until the receiver 186 * closes the connection. Calling VSTREAM_GETC() has the benefit of using 187 * whatever timeout is specified in the ipc_timeout parameter. 188 */ 189 (void) VSTREAM_GETC(stream); 190 return (err); 191 } 192 193 /* deliver_request_get - receive message delivery request */ 194 195 static int deliver_request_get(VSTREAM *stream, DELIVER_REQUEST *request) 196 { 197 const char *myname = "deliver_request_get"; 198 const char *path; 199 struct stat st; 200 static VSTRING *queue_name; 201 static VSTRING *queue_id; 202 static VSTRING *nexthop; 203 static VSTRING *encoding; 204 static VSTRING *address; 205 static VSTRING *client_name; 206 static VSTRING *client_addr; 207 static VSTRING *client_port; 208 static VSTRING *client_proto; 209 static VSTRING *client_helo; 210 static VSTRING *sasl_method; 211 static VSTRING *sasl_username; 212 static VSTRING *sasl_sender; 213 static VSTRING *log_ident; 214 static VSTRING *rewrite_context; 215 static VSTRING *dsn_envid; 216 static RCPT_BUF *rcpt_buf; 217 int rcpt_count; 218 int smtputf8; 219 int dsn_ret; 220 221 /* 222 * Initialize. For some reason I wanted to allow for multiple instances 223 * of a deliver_request structure, thus the hoopla with string 224 * initialization and copying. 225 */ 226 if (queue_name == 0) { 227 queue_name = vstring_alloc(10); 228 queue_id = vstring_alloc(10); 229 nexthop = vstring_alloc(10); 230 encoding = vstring_alloc(10); 231 address = vstring_alloc(10); 232 client_name = vstring_alloc(10); 233 client_addr = vstring_alloc(10); 234 client_port = vstring_alloc(10); 235 client_proto = vstring_alloc(10); 236 client_helo = vstring_alloc(10); 237 sasl_method = vstring_alloc(10); 238 sasl_username = vstring_alloc(10); 239 sasl_sender = vstring_alloc(10); 240 log_ident = vstring_alloc(10); 241 rewrite_context = vstring_alloc(10); 242 dsn_envid = vstring_alloc(10); 243 rcpt_buf = rcpb_create(); 244 } 245 246 /* 247 * Extract the queue file name, data offset, and sender address. Abort 248 * the conversation when they send bad information. 249 */ 250 if (attr_scan(stream, ATTR_FLAG_STRICT, 251 RECV_ATTR_INT(MAIL_ATTR_FLAGS, &request->flags), 252 RECV_ATTR_STR(MAIL_ATTR_QUEUE, queue_name), 253 RECV_ATTR_STR(MAIL_ATTR_QUEUEID, queue_id), 254 RECV_ATTR_LONG(MAIL_ATTR_OFFSET, &request->data_offset), 255 RECV_ATTR_LONG(MAIL_ATTR_SIZE, &request->data_size), 256 RECV_ATTR_STR(MAIL_ATTR_NEXTHOP, nexthop), 257 RECV_ATTR_STR(MAIL_ATTR_ENCODING, encoding), 258 RECV_ATTR_INT(MAIL_ATTR_SMTPUTF8, &smtputf8), 259 RECV_ATTR_STR(MAIL_ATTR_SENDER, address), 260 RECV_ATTR_STR(MAIL_ATTR_DSN_ENVID, dsn_envid), 261 RECV_ATTR_INT(MAIL_ATTR_DSN_RET, &dsn_ret), 262 RECV_ATTR_FUNC(msg_stats_scan, (void *) &request->msg_stats), 263 /* XXX Should be encapsulated with ATTR_TYPE_FUNC. */ 264 RECV_ATTR_STR(MAIL_ATTR_LOG_CLIENT_NAME, client_name), 265 RECV_ATTR_STR(MAIL_ATTR_LOG_CLIENT_ADDR, client_addr), 266 RECV_ATTR_STR(MAIL_ATTR_LOG_CLIENT_PORT, client_port), 267 RECV_ATTR_STR(MAIL_ATTR_LOG_PROTO_NAME, client_proto), 268 RECV_ATTR_STR(MAIL_ATTR_LOG_HELO_NAME, client_helo), 269 /* XXX Should be encapsulated with ATTR_TYPE_FUNC. */ 270 RECV_ATTR_STR(MAIL_ATTR_SASL_METHOD, sasl_method), 271 RECV_ATTR_STR(MAIL_ATTR_SASL_USERNAME, sasl_username), 272 RECV_ATTR_STR(MAIL_ATTR_SASL_SENDER, sasl_sender), 273 /* XXX Ditto if we want to pass TLS certificate info. */ 274 RECV_ATTR_STR(MAIL_ATTR_LOG_IDENT, log_ident), 275 RECV_ATTR_STR(MAIL_ATTR_RWR_CONTEXT, rewrite_context), 276 RECV_ATTR_INT(MAIL_ATTR_RCPT_COUNT, &rcpt_count), 277 ATTR_TYPE_END) != 23) { 278 msg_warn("%s: error receiving common attributes", myname); 279 return (-1); 280 } 281 if (mail_open_ok(vstring_str(queue_name), 282 vstring_str(queue_id), &st, &path) == 0) 283 return (-1); 284 285 /* Don't override hand-off time after deliver_pass() delegation. */ 286 if (request->msg_stats.agent_handoff.tv_sec == 0) 287 GETTIMEOFDAY(&request->msg_stats.agent_handoff); 288 289 request->queue_name = mystrdup(vstring_str(queue_name)); 290 request->queue_id = mystrdup(vstring_str(queue_id)); 291 request->nexthop = mystrdup(vstring_str(nexthop)); 292 request->encoding = mystrdup(vstring_str(encoding)); 293 /* Fix 20140708: dedicated smtputf8 attribute with its own flags. */ 294 request->smtputf8 = smtputf8; 295 request->sender = mystrdup(vstring_str(address)); 296 request->client_name = mystrdup(vstring_str(client_name)); 297 request->client_addr = mystrdup(vstring_str(client_addr)); 298 request->client_port = mystrdup(vstring_str(client_port)); 299 request->client_proto = mystrdup(vstring_str(client_proto)); 300 request->client_helo = mystrdup(vstring_str(client_helo)); 301 request->sasl_method = mystrdup(vstring_str(sasl_method)); 302 request->sasl_username = mystrdup(vstring_str(sasl_username)); 303 request->sasl_sender = mystrdup(vstring_str(sasl_sender)); 304 request->log_ident = mystrdup(vstring_str(log_ident)); 305 request->rewrite_context = mystrdup(vstring_str(rewrite_context)); 306 request->dsn_envid = mystrdup(vstring_str(dsn_envid)); 307 request->dsn_ret = dsn_ret; 308 309 /* 310 * Extract the recipient offset and address list. Skip over any 311 * attributes from the sender that we do not understand. 312 */ 313 while (rcpt_count-- > 0) { 314 if (attr_scan(stream, ATTR_FLAG_STRICT, 315 RECV_ATTR_FUNC(rcpb_scan, (void *) rcpt_buf), 316 ATTR_TYPE_END) != 1) { 317 msg_warn("%s: error receiving recipient attributes", myname); 318 return (-1); 319 } 320 recipient_list_add(&request->rcpt_list, rcpt_buf->offset, 321 vstring_str(rcpt_buf->dsn_orcpt), 322 rcpt_buf->dsn_notify, 323 vstring_str(rcpt_buf->orig_addr), 324 vstring_str(rcpt_buf->address)); 325 } 326 if (request->rcpt_list.len <= 0) { 327 msg_warn("%s: no recipients in delivery request for destination %s", 328 request->queue_id, request->nexthop); 329 return (-1); 330 } 331 332 /* 333 * Open the queue file and set a shared lock, in order to prevent 334 * duplicate deliveries when the queue is flushed immediately after queue 335 * manager restart. 336 * 337 * The queue manager locks the file exclusively when it enters the active 338 * queue, and releases the lock before starting deliveries from that 339 * file. The queue manager does not lock the file again when reading more 340 * recipients into memory. When the queue manager is restarted, the new 341 * process moves files from the active queue to the incoming queue to 342 * cool off for a while. Delivery agents should therefore never try to 343 * open a file that is locked by a queue manager process. 344 * 345 * Opening the queue file can fail for a variety of reasons, such as the 346 * system running out of resources. Instead of throwing away mail, we're 347 * raising a fatal error which forces the mail system to back off, and 348 * retry later. 349 */ 350 #define DELIVER_LOCK_MODE (MYFLOCK_OP_SHARED | MYFLOCK_OP_NOWAIT) 351 352 request->fp = 353 mail_queue_open(request->queue_name, request->queue_id, O_RDWR, 0); 354 if (request->fp == 0) { 355 if (errno != ENOENT) 356 msg_fatal("open %s %s: %m", request->queue_name, request->queue_id); 357 msg_warn("open %s %s: %m", request->queue_name, request->queue_id); 358 return (-1); 359 } 360 if (msg_verbose) 361 msg_info("%s: file %s", myname, VSTREAM_PATH(request->fp)); 362 if (myflock(vstream_fileno(request->fp), INTERNAL_LOCK, DELIVER_LOCK_MODE) < 0) 363 msg_fatal("shared lock %s: %m", VSTREAM_PATH(request->fp)); 364 close_on_exec(vstream_fileno(request->fp), CLOSE_ON_EXEC); 365 366 return (0); 367 } 368 369 /* deliver_request_alloc - allocate delivery request structure */ 370 371 static DELIVER_REQUEST *deliver_request_alloc(void) 372 { 373 DELIVER_REQUEST *request; 374 375 request = (DELIVER_REQUEST *) mymalloc(sizeof(*request)); 376 request->fp = 0; 377 request->queue_name = 0; 378 request->queue_id = 0; 379 request->nexthop = 0; 380 request->encoding = 0; 381 request->sender = 0; 382 request->data_offset = 0; 383 request->data_size = 0; 384 recipient_list_init(&request->rcpt_list, RCPT_LIST_INIT_STATUS); 385 request->hop_status = 0; 386 request->client_name = 0; 387 request->client_addr = 0; 388 request->client_port = 0; 389 request->client_proto = 0; 390 request->client_helo = 0; 391 request->sasl_method = 0; 392 request->sasl_username = 0; 393 request->sasl_sender = 0; 394 request->log_ident = 0; 395 request->rewrite_context = 0; 396 request->dsn_envid = 0; 397 return (request); 398 } 399 400 /* deliver_request_free - clean up delivery request structure */ 401 402 static void deliver_request_free(DELIVER_REQUEST *request) 403 { 404 if (request->fp) 405 vstream_fclose(request->fp); 406 if (request->queue_name) 407 myfree(request->queue_name); 408 if (request->queue_id) 409 myfree(request->queue_id); 410 if (request->nexthop) 411 myfree(request->nexthop); 412 if (request->encoding) 413 myfree(request->encoding); 414 if (request->sender) 415 myfree(request->sender); 416 recipient_list_free(&request->rcpt_list); 417 if (request->hop_status) 418 dsn_free(request->hop_status); 419 if (request->client_name) 420 myfree(request->client_name); 421 if (request->client_addr) 422 myfree(request->client_addr); 423 if (request->client_port) 424 myfree(request->client_port); 425 if (request->client_proto) 426 myfree(request->client_proto); 427 if (request->client_helo) 428 myfree(request->client_helo); 429 if (request->sasl_method) 430 myfree(request->sasl_method); 431 if (request->sasl_username) 432 myfree(request->sasl_username); 433 if (request->sasl_sender) 434 myfree(request->sasl_sender); 435 if (request->log_ident) 436 myfree(request->log_ident); 437 if (request->rewrite_context) 438 myfree(request->rewrite_context); 439 if (request->dsn_envid) 440 myfree(request->dsn_envid); 441 myfree((void *) request); 442 } 443 444 /* deliver_request_read - create and read delivery request */ 445 446 DELIVER_REQUEST *deliver_request_read(VSTREAM *stream) 447 { 448 DELIVER_REQUEST *request; 449 450 /* 451 * Tell the queue manager that we are ready for this request. 452 */ 453 if (deliver_request_initial(stream) != 0) 454 return (0); 455 456 /* 457 * Be prepared for the queue manager to change its mind after contacting 458 * us. This can happen when a transport or host goes bad. 459 */ 460 (void) read_wait(vstream_fileno(stream), -1); 461 if (peekfd(vstream_fileno(stream)) <= 0) 462 return (0); 463 464 /* 465 * Allocate and read the queue manager's delivery request. 466 */ 467 #define XXX_DEFER_STATUS -1 468 469 request = deliver_request_alloc(); 470 if (deliver_request_get(stream, request) < 0) { 471 deliver_request_done(stream, request, XXX_DEFER_STATUS); 472 request = 0; 473 } 474 return (request); 475 } 476 477 /* deliver_request_done - finish delivery request */ 478 479 int deliver_request_done(VSTREAM *stream, DELIVER_REQUEST *request, int status) 480 { 481 int err; 482 483 err = deliver_request_final(stream, request, status); 484 deliver_request_free(request); 485 return (err); 486 } 487