Mercurial > dnsbl
annotate src/dnsbl.cpp @ 129:c5cd1261394d
ignore smtp connection attempts for 10 minutes when getting connection errors on verify hosts
| author | carl |
|---|---|
| date | Tue, 06 Jun 2006 08:45:07 -0700 |
| parents | 9ab51896447f |
| children | df355d117199 |
| rev | line source |
|---|---|
| 94 | 1 /* |
| 2 | |
| 3 Copyright (c) 2004, 2005 Carl Byington - 510 Software Group, released | |
| 4 under the GPL version 2 or any later version at your choice available at | |
| 5 http://www.fsf.org/licenses/gpl.txt | |
| 6 | |
| 7 Based on a sample milter Copyright (c) 2000-2003 Sendmail, Inc. and its | |
| 8 suppliers. Inspired by the DCC by Rhyolite Software | |
| 9 | |
| 10 -r port The port used to talk to our internal dns resolver processes | |
| 11 -p port The port through which the MTA will connect to this milter. | |
| 12 -t sec The timeout value. | |
| 13 -c Check the config, and print a copy to stdout. Don't start the | |
| 14 milter or do anything with the socket. | |
| 15 -s Stress test by loading and deleting the current config in a loop. | |
| 16 -d increase debug level | |
| 17 -e f|t Print the results of looking up from address f and to address | |
| 18 t in the current config | |
| 19 | |
| 20 */ | |
| 21 | |
| 22 | |
| 23 // from sendmail sample | |
| 24 #include <sys/types.h> | |
| 25 #include <sys/stat.h> | |
| 26 #include <errno.h> | |
| 27 #include <sysexits.h> | |
| 28 #include <unistd.h> | |
| 29 | |
| 30 // needed for socket io | |
| 31 #include <sys/ioctl.h> | |
| 32 #include <net/if.h> | |
| 33 #include <arpa/inet.h> | |
| 34 #include <netinet/in.h> | |
| 35 #include <netinet/tcp.h> | |
| 36 #include <netdb.h> | |
| 37 #include <sys/socket.h> | |
| 38 #include <sys/un.h> | |
| 39 | |
| 40 // needed for thread | |
| 41 #include <pthread.h> | |
| 42 | |
| 43 // needed for std c++ collections | |
| 44 #include <set> | |
| 45 #include <map> | |
| 46 #include <list> | |
| 47 | |
| 48 // for the dns resolver | |
| 49 #include <netinet/in.h> | |
| 50 #include <arpa/nameser.h> | |
| 51 #include <resolv.h> | |
| 52 | |
| 53 // misc stuff needed here | |
| 54 #include <ctype.h> | |
| 55 #include <syslog.h> | |
| 56 #include <pwd.h> | |
| 57 #include <sys/wait.h> /* header for waitpid() and various macros */ | |
| 58 #include <signal.h> /* header for signal functions */ | |
| 59 | |
| 60 #include "includes.h" | |
| 61 | |
| 62 static char* dnsbl_version="$Id$"; | |
| 63 | |
| 64 | |
| 65 extern "C" { | |
| 66 #include "libmilter/mfapi.h" | |
| 67 sfsistat mlfi_connect(SMFICTX *ctx, char *hostname, _SOCK_ADDR *hostaddr); | |
| 68 sfsistat mlfi_envfrom(SMFICTX *ctx, char **argv); | |
| 69 sfsistat mlfi_envrcpt(SMFICTX *ctx, char **argv); | |
| 70 sfsistat mlfi_body(SMFICTX *ctx, u_char *data, size_t len); | |
| 71 sfsistat mlfi_eom(SMFICTX *ctx); | |
| 72 sfsistat mlfi_abort(SMFICTX *ctx); | |
| 73 sfsistat mlfi_close(SMFICTX *ctx); | |
| 74 void sig_chld(int signo); | |
| 75 } | |
| 76 | |
| 77 int debug_syslog = 0; | |
| 78 bool syslog_opened = false; | |
| 79 bool use_syslog = true; // false to printf | |
| 80 bool loader_run = true; // used to stop the config loader thread | |
| 81 CONFIG *config = NULL; // protected by the config_mutex | |
| 82 int generation = 0; // protected by the config_mutex | |
| 83 const int maxlen = 1000; // used for snprintf buffers | |
| 84 | |
| 85 pthread_mutex_t config_mutex; | |
| 86 pthread_mutex_t syslog_mutex; | |
| 87 pthread_mutex_t resolve_mutex; | |
| 88 pthread_mutex_t fd_pool_mutex; | |
| 89 | |
| 90 std::set<int> fd_pool; | |
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91 const int NULL_SOCKET = -1; |
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92 const time_t ERROR_SOCKET_TIME = 60; // number of seconds between attempts to open a socket to the dns resolver process |
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93 char *resolver_port = NULL; // unix domain socket to talk to the dns resolver process |
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94 int resolver_socket = NULL_SOCKET; // socket used to listen for resolver requests |
| 94 | 95 time_t last_error_time; |
| 96 int resolver_sock_count = 0; // protected with fd_pool_mutex | |
| 97 int resolver_pool_size = 0; // protected with fd_pool_mutex | |
| 98 | |
| 99 | |
| 100 struct ns_map { | |
| 101 // all the strings are owned by the keys/values in the ns_host string map | |
| 102 string_map ns_host; // nameserver name -> host name that uses this name server | |
| 103 ns_mapper ns_ip; // nameserver name -> ip address of the name server | |
| 104 ~ns_map(); | |
| 105 void add(char *name, char *refer); | |
| 106 }; | |
| 107 | |
| 108 | |
| 109 ns_map::~ns_map() { | |
| 110 for (string_map::iterator i=ns_host.begin(); i!=ns_host.end(); i++) { | |
| 111 char *x = (*i).first; | |
| 112 char *y = (*i).second; | |
| 113 free(x); | |
| 114 free(y); | |
| 115 } | |
| 116 ns_ip.clear(); | |
| 117 ns_host.clear(); | |
| 118 } | |
| 119 | |
| 120 | |
| 121 void ns_map::add(char *name, char *refer) { | |
| 122 string_map::iterator i = ns_host.find(name); | |
| 123 if (i != ns_host.end()) return; | |
| 124 char *x = strdup(name); | |
| 125 char *y = strdup(refer); | |
| 126 ns_ip[x] = 0; | |
| 127 ns_host[x] = y; | |
| 128 | |
| 129 } | |
| 130 | |
| 131 // packed structure to allow a single socket write to dump the | |
| 132 // length and the following answer. The packing attribute is gcc specific. | |
| 133 struct glommer { | |
| 134 int length; | |
| 135 #ifdef NS_PACKETSZ | |
| 115 | 136 u_char answer[NS_PACKETSZ*4]; // with a resolver, we return resolver answers |
| 94 | 137 #else |
| 138 int answer; // without a resolver, we return a single ip4 address, 0 == no answer | |
| 139 #endif | |
| 140 } __attribute__ ((packed)); | |
| 141 | |
| 142 | |
| 143 //////////////////////////////////////////////// | |
| 144 // helper to discard the strings held by a context_map | |
| 145 // | |
| 146 void discard(context_map &cm); | |
| 147 void discard(context_map &cm) { | |
| 148 for (context_map::iterator i=cm.begin(); i!=cm.end(); i++) { | |
| 149 char *x = (*i).first; | |
| 150 free(x); | |
| 151 } | |
| 152 cm.clear(); | |
| 153 } | |
| 154 | |
| 155 | |
| 156 //////////////////////////////////////////////// | |
| 157 // helper to register a string in a context_map | |
| 158 // | |
| 159 void register_string(context_map &cm, char *name, CONTEXT *con); | |
| 160 void register_string(context_map &cm, char *name, CONTEXT *con) { | |
| 161 context_map::iterator i = cm.find(name); | |
| 162 if (i != cm.end()) return; | |
| 163 char *x = strdup(name); | |
| 164 cm[x] = con; | |
| 165 } | |
| 166 | |
| 167 | |
| 168 //////////////////////////////////////////////// | |
| 169 // disconnect the fd from the dns resolver process | |
| 170 // | |
| 171 void my_disconnect(int sock, bool decrement = true); | |
| 172 void my_disconnect(int sock, bool decrement) { | |
| 173 if (sock != NULL_SOCKET) { | |
| 174 if (decrement) { | |
| 175 pthread_mutex_lock(&fd_pool_mutex); | |
| 176 resolver_sock_count--; | |
| 177 pthread_mutex_unlock(&fd_pool_mutex); | |
| 178 } | |
| 179 shutdown(sock, SHUT_RDWR); | |
| 180 close(sock); | |
| 181 } | |
| 182 } | |
| 183 | |
| 184 | |
| 185 //////////////////////////////////////////////// | |
| 186 // return fd connected to the dns resolver process | |
| 187 // | |
| 188 int my_connect(); | |
| 189 int my_connect() { | |
| 190 // if we have had recent errors, don't even try to open the socket | |
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191 if ((time(NULL) - last_error_time) < ERROR_SOCKET_TIME) return NULL_SOCKET; |
| 94 | 192 |
| 193 // nothing recent, maybe this time it will work | |
| 194 int sock = NULL_SOCKET; | |
| 195 sockaddr_un server; | |
| 196 memset(&server, '\0', sizeof(server)); | |
| 197 server.sun_family = AF_UNIX; | |
| 198 strncpy(server.sun_path, resolver_port, sizeof(server.sun_path)-1); | |
| 199 sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
| 200 if (sock != NULL_SOCKET) { | |
| 201 bool rc = (connect(sock, (sockaddr *)&server, sizeof(server)) == 0); | |
| 202 if (!rc) { | |
| 203 my_disconnect(sock, false); | |
| 204 sock = NULL_SOCKET; | |
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205 last_error_time = time(NULL); |
| 94 | 206 } |
| 207 } | |
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208 else last_error_time = time(NULL); |
| 94 | 209 if (sock != NULL_SOCKET) { |
| 210 pthread_mutex_lock(&fd_pool_mutex); | |
| 211 resolver_sock_count++; | |
| 212 pthread_mutex_unlock(&fd_pool_mutex); | |
| 213 } | |
| 214 return sock; | |
| 215 } | |
| 216 | |
| 217 | |
| 218 mlfiPriv::mlfiPriv() { | |
| 219 pthread_mutex_lock(&config_mutex); | |
| 220 pc = config; | |
| 221 pc->reference_count++; | |
| 222 pthread_mutex_unlock(&config_mutex); | |
| 223 get_fd(); | |
| 224 ip = 0; | |
| 225 mailaddr = NULL; | |
| 226 queueid = NULL; | |
| 227 authenticated = false; | |
| 228 have_whites = false; | |
| 229 only_whites = true; | |
| 230 memory = NULL; | |
| 231 scanner = NULL; | |
| 232 content_suffix = NULL; | |
| 233 content_message = NULL; | |
| 119 | 234 uribl_suffix = NULL; |
| 235 uribl_message = NULL; | |
| 94 | 236 content_host_ignore = NULL; |
| 237 } | |
| 238 | |
| 239 mlfiPriv::~mlfiPriv() { | |
| 240 return_fd(); | |
| 241 pthread_mutex_lock(&config_mutex); | |
| 242 pc->reference_count--; | |
| 243 pthread_mutex_unlock(&config_mutex); | |
| 244 reset(true); | |
| 245 } | |
| 246 | |
| 247 void mlfiPriv::reset(bool final) { | |
| 248 if (mailaddr) free(mailaddr); | |
| 249 if (queueid) free(queueid); | |
| 250 discard(env_to); | |
| 251 if (memory) delete memory; | |
| 252 if (scanner) delete scanner; | |
| 253 if (!final) { | |
| 254 mailaddr = NULL; | |
| 255 queueid = NULL; | |
| 256 authenticated = false; | |
| 257 have_whites = false; | |
| 258 only_whites = true; | |
| 259 memory = NULL; | |
| 260 scanner = NULL; | |
| 261 content_suffix = NULL; | |
| 262 content_message = NULL; | |
| 119 | 263 uribl_suffix = NULL; |
| 264 uribl_message = NULL; | |
| 94 | 265 content_host_ignore = NULL; |
| 266 } | |
| 267 } | |
| 268 | |
| 269 void mlfiPriv::get_fd() { | |
| 270 err = true; | |
| 271 fd = NULL_SOCKET; | |
| 272 int result = pthread_mutex_lock(&fd_pool_mutex); | |
| 273 if (!result) { | |
| 274 std::set<int>::iterator i; | |
| 275 i = fd_pool.begin(); | |
| 276 if (i != fd_pool.end()) { | |
| 277 // have at least one fd in the pool | |
| 278 err = false; | |
| 279 fd = *i; | |
| 280 fd_pool.erase(fd); | |
| 281 resolver_pool_size--; | |
| 282 pthread_mutex_unlock(&fd_pool_mutex); | |
| 283 } | |
| 284 else { | |
| 285 // pool is empty, get a new fd | |
| 286 pthread_mutex_unlock(&fd_pool_mutex); | |
| 287 fd = my_connect(); | |
| 288 err = (fd == NULL_SOCKET); | |
| 289 } | |
| 290 } | |
| 291 else { | |
| 292 // cannot lock the pool, just get a new fd | |
| 293 fd = my_connect(); | |
| 294 err = (fd == NULL_SOCKET); | |
| 295 } | |
| 296 } | |
| 297 | |
| 298 void mlfiPriv::return_fd() { | |
| 299 if (err) { | |
| 300 // this fd got a socket error, so close it, rather than returning it to the pool | |
| 301 my_disconnect(fd); | |
| 302 } | |
| 303 else { | |
| 304 int result = pthread_mutex_lock(&fd_pool_mutex); | |
| 305 if (!result) { | |
| 306 if ((resolver_sock_count > resolver_pool_size*5) || (resolver_pool_size < 5)) { | |
| 307 // return the fd to the pool | |
| 308 fd_pool.insert(fd); | |
| 309 resolver_pool_size++; | |
| 310 pthread_mutex_unlock(&fd_pool_mutex); | |
| 311 } | |
| 312 else { | |
| 313 // more than 20% of the open resolver sockets are in the pool, and the | |
| 314 // pool as at least 5 sockets. that is enough, so just close this one. | |
| 315 pthread_mutex_unlock(&fd_pool_mutex); | |
| 316 my_disconnect(fd); | |
| 317 } | |
| 318 } | |
| 319 else { | |
| 320 // could not lock the pool, so just close the fd | |
| 321 my_disconnect(fd); | |
| 322 } | |
| 323 } | |
| 324 } | |
| 325 | |
| 326 int mlfiPriv::my_write(char *buf, int len) { | |
| 327 if (err) return 0; | |
| 328 int rs = 0; | |
| 329 while (len) { | |
| 330 int ws = write(fd, buf, len); | |
| 331 if (ws > 0) { | |
| 332 rs += ws; | |
| 333 len -= ws; | |
| 334 buf += ws; | |
| 335 } | |
| 336 else { | |
| 337 // peer closed the socket! | |
| 338 rs = 0; | |
| 339 err = true; | |
| 340 break; | |
| 341 } | |
| 342 } | |
| 343 return rs; | |
| 344 } | |
| 345 | |
| 346 int mlfiPriv::my_read(char *buf, int len) { | |
| 347 if (err) return 0; | |
| 348 int rs = 0; | |
| 349 while (len > 1) { | |
| 350 int ws = read(fd, buf, len); | |
| 351 if (ws > 0) { | |
| 352 rs += ws; | |
| 353 len -= ws; | |
| 354 buf += ws; | |
| 355 } | |
| 356 else { | |
| 357 // peer closed the socket! | |
| 358 rs = 0; | |
| 359 err = true; | |
| 360 break; | |
| 361 } | |
| 362 } | |
| 363 return rs; | |
| 364 } | |
| 365 | |
| 366 void mlfiPriv::need_content_filter(char *rcpt, CONTEXT &con) { | |
| 367 register_string(env_to, rcpt, &con); | |
| 368 if (!memory) { | |
| 369 // first recipient that needs content filtering sets all | |
| 370 // the content filtering parameters | |
| 117 | 371 memory = new recorder(this, con.get_html_tags(), con.get_content_tlds(), con.get_content_cctlds()); |
| 94 | 372 scanner = new url_scanner(memory); |
| 373 content_suffix = con.get_content_suffix(); | |
| 374 content_message = con.get_content_message(); | |
| 119 | 375 uribl_suffix = con.get_uribl_suffix(); |
| 376 uribl_message = con.get_uribl_message(); | |
| 94 | 377 content_host_ignore = &con.get_content_host_ignore(); |
| 378 } | |
| 379 } | |
| 380 | |
| 381 #define MLFIPRIV ((struct mlfiPriv *) smfi_getpriv(ctx)) | |
| 382 | |
| 383 | |
| 384 //////////////////////////////////////////////// | |
| 385 // syslog a message | |
| 386 // | |
| 387 void my_syslog(mlfiPriv *priv, char *text) { | |
| 388 char buf[maxlen]; | |
| 389 if (priv) { | |
| 390 snprintf(buf, sizeof(buf), "%s: %s", priv->queueid, text); | |
| 391 text = buf; | |
| 392 } | |
| 393 if (use_syslog) { | |
| 394 pthread_mutex_lock(&syslog_mutex); | |
| 395 if (!syslog_opened) { | |
| 396 openlog("dnsbl", LOG_PID, LOG_MAIL); | |
| 397 syslog_opened = true; | |
| 398 } | |
| 399 syslog(LOG_NOTICE, "%s", text); | |
| 400 pthread_mutex_unlock(&syslog_mutex); | |
| 401 } | |
| 402 else { | |
| 403 printf("%s \n", text); | |
| 404 } | |
| 405 } | |
| 406 | |
| 407 void my_syslog(char *text) { | |
| 408 my_syslog(NULL, text); | |
| 409 } | |
| 410 | |
| 411 | |
| 412 //////////////////////////////////////////////// | |
| 413 // read a resolver request from the socket, process it, and | |
| 414 // write the result back to the socket. | |
| 415 | |
| 416 void process_resolver_requests(int socket); | |
| 417 void process_resolver_requests(int socket) { | |
| 418 #ifdef NS_MAXDNAME | |
| 419 char question[NS_MAXDNAME]; | |
| 420 #else | |
| 421 char question[1000]; | |
| 422 #endif | |
| 423 glommer glom; | |
| 424 | |
| 425 int maxq = sizeof(question); | |
| 426 while (true) { | |
| 427 // read a question | |
| 428 int rs = 0; | |
| 429 while (rs < maxq) { | |
| 430 int ns = read(socket, question+rs, maxq-rs); | |
| 431 if (ns > 0) { | |
| 432 rs += ns; | |
| 433 if (question[rs-1] == '\0') { | |
| 434 // last byte read was the null terminator, we are done | |
| 435 break; | |
| 436 } | |
| 437 } | |
| 438 else { | |
| 439 // peer closed the socket | |
| 440 #ifdef RESOLVER_DEBUG | |
| 441 my_syslog("process_resolver_requests() peer closed socket while reading question"); | |
| 442 #endif | |
| 443 shutdown(socket, SHUT_RDWR); | |
| 444 close(socket); | |
| 445 return; | |
| 446 } | |
| 447 } | |
| 448 question[rs-1] = '\0'; // ensure null termination | |
| 449 | |
| 450 // find the answer | |
| 451 #ifdef NS_PACKETSZ | |
| 452 #ifdef RESOLVER_DEBUG | |
| 453 char text[1000]; | |
| 454 snprintf(text, sizeof(text), "process_resolver_requests() has a question %s", question); | |
| 455 my_syslog(text); | |
| 456 #endif | |
| 457 glom.length = res_search(question, ns_c_in, ns_t_a, glom.answer, sizeof(glom.answer)); | |
| 458 if (glom.length < 0) glom.length = 0; // represent all errors as zero length answers | |
| 459 #else | |
| 460 glom.length = sizeof(glom.answer); | |
| 461 glom.answer = 0; | |
| 462 struct hostent *host = gethostbyname(question); | |
| 463 if (host && (host->h_addrtype == AF_INET)) { | |
| 464 memcpy(&glom.answer, host->h_addr, sizeof(glom.answer)); | |
| 465 } | |
| 466 #endif | |
| 467 | |
| 468 // write the answer | |
| 469 char *buf = (char *)&glom; | |
| 470 int len = glom.length + sizeof(glom.length); | |
| 471 #ifdef RESOLVER_DEBUG | |
| 472 snprintf(text, sizeof(text), "process_resolver_requests() writing answer length %d for total %d", glom.length, len); | |
| 473 my_syslog(text); | |
| 474 #endif | |
| 475 int ws = 0; | |
| 476 while (len > ws) { | |
| 477 int ns = write(socket, buf+ws, len-ws); | |
| 478 if (ns > 0) { | |
| 479 ws += ns; | |
| 480 } | |
| 481 else { | |
| 482 // peer closed the socket! | |
| 483 #ifdef RESOLVER_DEBUG | |
| 484 my_syslog("process_resolver_requests() peer closed socket while writing answer"); | |
| 485 #endif | |
| 486 shutdown(socket, SHUT_RDWR); | |
| 487 close(socket); | |
| 488 return; | |
| 489 } | |
| 490 } | |
| 491 } | |
| 492 } | |
| 493 | |
| 494 | |
| 495 //////////////////////////////////////////////// | |
| 496 // ask a dns question and get an A record answer - we don't try | |
| 497 // very hard, just using the default resolver retry settings. | |
| 498 // If we cannot get an answer, we just accept the mail. | |
| 499 // | |
| 500 // | |
| 501 int dns_interface(mlfiPriv &priv, char *question, bool maybe_ip, ns_map *nameservers); | |
| 502 int dns_interface(mlfiPriv &priv, char *question, bool maybe_ip, ns_map *nameservers) { | |
| 503 // this part can be done without locking the resolver mutex. Each | |
| 504 // milter thread is talking over its own socket to a separate resolver | |
| 505 // process, which does the actual dns resolution. | |
| 506 if (priv.err) return 0; // cannot ask more questions on this socket. | |
| 507 priv.my_write(question, strlen(question)+1); // write the question including the null terminator | |
| 508 glommer glom; | |
| 509 char *buf = (char *)&glom; | |
| 510 priv.my_read(buf, sizeof(glom.length)); | |
| 511 buf += sizeof(glom.length); | |
| 512 #ifdef RESOLVER_DEBUG | |
| 513 char text[1000]; | |
| 514 snprintf(text, sizeof(text), "dns_interface() wrote question %s and has answer length %d", question, glom.length); | |
| 515 my_syslog(text); | |
| 516 #endif | |
| 517 if ((glom.length < 0) || (glom.length > sizeof(glom.answer))) { | |
| 518 priv.err = true; | |
| 519 return 0; // cannot process overlarge answers | |
| 520 } | |
| 521 priv.my_read(buf, glom.length); | |
| 522 | |
| 523 #ifdef NS_PACKETSZ | |
| 524 // now we need to lock the resolver mutex to keep the milter threads from | |
| 525 // stepping on each other while parsing the dns answer. | |
| 526 int ret_address = 0; | |
| 527 pthread_mutex_lock(&resolve_mutex); | |
| 528 if (glom.length > 0) { | |
| 529 // parse the answer | |
| 530 ns_msg handle; | |
| 531 ns_rr rr; | |
| 532 if (ns_initparse(glom.answer, glom.length, &handle) == 0) { | |
| 533 // look for ns names | |
| 534 if (nameservers) { | |
| 535 ns_map &ns = *nameservers; | |
| 536 int rrnum = 0; | |
| 537 while (ns_parserr(&handle, ns_s_ns, rrnum++, &rr) == 0) { | |
| 538 if (ns_rr_type(rr) == ns_t_ns) { | |
| 539 char nam[NS_MAXDNAME+1]; | |
| 540 char *n = nam; | |
| 541 const u_char *p = ns_rr_rdata(rr); | |
| 542 while (((n-nam) < NS_MAXDNAME) && ((p-glom.answer) < glom.length) && *p) { | |
| 543 size_t s = *(p++); | |
| 544 if (s > 191) { | |
| 545 // compression pointer | |
| 546 s = (s-192)*256 + *(p++); | |
| 547 if (s >= glom.length) break; // pointer outside bounds of answer | |
| 548 p = glom.answer + s; | |
| 549 s = *(p++); | |
| 550 } | |
| 551 if (s > 0) { | |
| 552 if ((n-nam) >= (NS_MAXDNAME-s)) break; // destination would overflow name buffer | |
| 553 if ((p-glom.answer) >= (glom.length-s)) break; // source outside bounds of answer | |
| 554 memcpy(n, p, s); | |
| 555 n += s; | |
| 556 p += s; | |
| 557 *(n++) = '.'; | |
| 558 } | |
| 559 } | |
| 560 if (n-nam) n--; // remove trailing . | |
| 561 *n = '\0'; // null terminate it | |
| 562 ns.add(nam, question); // ns host to lookup later | |
| 563 } | |
| 564 } | |
| 565 rrnum = 0; | |
| 566 while (ns_parserr(&handle, ns_s_ar, rrnum++, &rr) == 0) { | |
| 567 if (ns_rr_type(rr) == ns_t_a) { | |
| 568 char* nam = (char*)ns_rr_name(rr); | |
| 569 ns_mapper::iterator i = ns.ns_ip.find(nam); | |
| 570 if (i != ns.ns_ip.end()) { | |
| 571 // we want this ip address | |
| 572 int address; | |
| 573 memcpy(&address, ns_rr_rdata(rr), sizeof(address)); | |
| 574 ns.ns_ip[nam] = address; | |
| 575 } | |
| 576 } | |
| 577 } | |
| 578 } | |
| 579 int rrnum = 0; | |
| 580 while (ns_parserr(&handle, ns_s_an, rrnum++, &rr) == 0) { | |
| 581 if (ns_rr_type(rr) == ns_t_a) { | |
| 582 int address; | |
| 583 memcpy(&address, ns_rr_rdata(rr), sizeof(address)); | |
| 584 ret_address = address; | |
| 585 } | |
| 586 } | |
| 587 } | |
| 588 } | |
| 589 if (maybe_ip && !ret_address) { | |
| 590 // might be a bare ip address | |
| 591 in_addr ip; | |
| 592 if (inet_aton(question, &ip)) { | |
| 593 ret_address = ip.s_addr; | |
| 594 } | |
| 595 } | |
| 596 pthread_mutex_unlock(&resolve_mutex); | |
| 597 return ret_address; | |
| 598 #else | |
| 599 return glom.answer; | |
| 600 #endif | |
| 601 } | |
| 602 | |
| 603 | |
| 604 //////////////////////////////////////////////// | |
| 605 // check a single dnsbl | |
| 606 // | |
| 607 bool check_single(mlfiPriv &priv, int ip, char *suffix); | |
| 608 bool check_single(mlfiPriv &priv, int ip, char *suffix) { | |
| 609 // make a dns question | |
| 610 const u_char *src = (const u_char *)&ip; | |
| 611 if (src[0] == 127) return false; // don't do dns lookups on localhost | |
| 126 | 612 if (src[0] == 10) return false; // don't do dns lookups on rfc1918 space |
| 613 if ((src[0] == 192) && (src[1] == 168)) return false; | |
| 614 if ((src[0] == 172) && (16 <= src[1]) && (src[1] <= 31)) return false; | |
| 94 | 615 #ifdef NS_MAXDNAME |
| 616 char question[NS_MAXDNAME]; | |
| 617 #else | |
| 618 char question[1000]; | |
| 619 #endif | |
| 620 snprintf(question, sizeof(question), "%u.%u.%u.%u.%s.", src[3], src[2], src[1], src[0], suffix); | |
| 621 // ask the question, if we get an A record it implies a blacklisted ip address | |
| 622 return dns_interface(priv, question, false, NULL); | |
| 623 } | |
| 624 | |
| 625 | |
| 626 //////////////////////////////////////////////// | |
| 627 // check a single dnsbl | |
| 628 // | |
| 629 bool check_single(mlfiPriv &priv, int ip, DNSBL &bl); | |
| 630 bool check_single(mlfiPriv &priv, int ip, DNSBL &bl) { | |
| 631 return check_single(priv, ip, bl.suffix); | |
| 632 } | |
| 633 | |
| 634 | |
| 635 //////////////////////////////////////////////// | |
| 636 // check the dnsbls specified for this recipient | |
| 637 // | |
| 638 bool check_dnsbl(mlfiPriv &priv, dnsblp_list &dnsbll, DNSBLP &rejectlist); | |
| 639 bool check_dnsbl(mlfiPriv &priv, dnsblp_list &dnsbll, DNSBLP &rejectlist) { | |
| 640 for (dnsblp_list::iterator i=dnsbll.begin(); i!=dnsbll.end(); i++) { | |
| 641 DNSBLP dp = *i; // non null by construction | |
| 642 bool st; | |
| 643 map<DNSBLP, bool>::iterator f = priv.checked.find(dp); | |
| 644 if (f == priv.checked.end()) { | |
| 645 // have not checked this list yet | |
| 646 st = check_single(priv, priv.ip, *dp); | |
| 647 rejectlist = dp; | |
| 648 priv.checked[dp] = st; | |
| 649 } | |
| 650 else { | |
| 651 st = (*f).second; | |
| 652 rejectlist = (*f).first; | |
| 653 } | |
| 654 if (st) return st; | |
| 655 } | |
| 656 return false; | |
| 657 } | |
| 658 | |
| 659 | |
| 660 //////////////////////////////////////////////// | |
| 117 | 661 // lookup the domain name part of a hostname on two lists |
| 662 // | |
| 124 | 663 // if we find part of the hostname on the uribl, return |
| 664 // true and point found to the part of the hostname that we found. | |
| 665 // otherwise, return false and preserve the value of found. | |
| 666 // | |
| 667 bool uriblookup(mlfiPriv &priv ,char *hostname, char *top, char *&found) ; | |
| 668 bool uriblookup(mlfiPriv &priv, char *hostname, char *top, char *&found) { | |
| 117 | 669 // top is pointer to '.' char at end of base domain, or null for ip address form |
| 670 // so for hostname of www.fred.mydomain.co.uk | |
| 671 // top points to-----------------------^ | |
| 672 // and we end up looking at only mydomain.co.uk, ignoring the www.fred stuff | |
| 673 char buf[maxlen]; | |
| 674 if (top) { | |
| 675 // add one more component | |
| 676 *top = '\0'; | |
| 677 char *x = strrchr(hostname, '.'); | |
| 678 if (x) hostname = x+1; | |
| 679 *top = '.'; | |
| 680 } | |
| 119 | 681 snprintf(buf, sizeof(buf), "%s.%s", hostname, priv.uribl_suffix); |
| 682 if (dns_interface(priv, buf, false, NULL)) { | |
| 117 | 683 if (debug_syslog > 2) { |
| 684 char tmp[maxlen]; | |
| 119 | 685 snprintf(tmp, sizeof(tmp), "found %s on %s", hostname, priv.uribl_suffix); |
| 117 | 686 my_syslog(tmp); |
| 687 } | |
| 124 | 688 found = hostname; |
| 119 | 689 return true; |
| 117 | 690 } |
| 691 return false; | |
| 692 } | |
| 693 | |
| 694 | |
| 695 //////////////////////////////////////////////// | |
| 124 | 696 // uribl checker |
| 697 // ------------- | |
| 698 // hostname MUST not have a trailing dot | |
| 699 // If tld, two level lookup. | |
| 700 // Else, look up three level domain. | |
| 701 // | |
| 702 // if we find part of the hostname on the uribl, return | |
| 703 // true and point found to the part of the hostname that we found. | |
| 704 // otherwise, return false and preserve the value of found. | |
| 705 // | |
| 706 bool check_uribl(mlfiPriv &priv, char *hostname, char *&found) ; | |
| 707 bool check_uribl(mlfiPriv &priv, char *hostname, char *&found) { | |
| 117 | 708 in_addr ip; |
| 709 if (inet_aton(hostname, &ip)) { | |
| 120 | 710 const u_char *src = (const u_char *)&ip.s_addr; |
| 128 | 711 if (src[0] == 127) return false; // don't do dns lookups on localhost |
| 712 if (src[0] == 10) return false; // don't do dns lookups on rfc1918 space | |
| 713 if ((src[0] == 192) && (src[1] == 168)) return false; | |
| 714 if ((src[0] == 172) && (16 <= src[1]) && (src[1] <= 31)) return false; | |
| 124 | 715 static char adr[sizeof "255.255.255.255"]; |
| 120 | 716 snprintf(adr, sizeof(adr), "%u.%u.%u.%u", src[3], src[2], src[1], src[0]); |
| 124 | 717 return (uriblookup(priv, adr, NULL, found)); |
| 117 | 718 } |
| 719 | |
| 720 char *top, *top2, *top3; | |
| 721 top = strrchr(hostname, '.'); | |
| 722 if (top) { | |
| 723 *top = '\0'; | |
| 724 top2 = strrchr(hostname, '.'); | |
| 725 *top = '.'; | |
| 726 | |
| 727 if (top2) { | |
| 728 string_set::iterator i = priv.memory->get_cctlds()->find(top2+1); | |
| 729 string_set::iterator x = priv.memory->get_cctlds()->end(); | |
| 730 // if we have a 2-level-cctld, just look at top three levels of the name | |
| 124 | 731 if (i != x) return uriblookup(priv, hostname, top2, found); |
| 117 | 732 |
| 733 *top2 = '\0'; | |
| 734 top3 = strrchr(hostname, '.'); | |
| 735 *top2 = '.'; | |
| 736 | |
| 737 // if we have more than 3 levels in the name, look at the top three levels of the name | |
| 124 | 738 if (top3 && uriblookup(priv, hostname, top2, found)) return true; |
| 117 | 739 // if that was not found, fall thru to looking at the top two levels |
| 740 } | |
| 741 // look at the top two levels of the name | |
| 124 | 742 return uriblookup(priv, hostname, top, found); |
| 117 | 743 } |
| 744 return false; | |
| 745 } | |
| 746 | |
| 747 | |
| 748 //////////////////////////////////////////////// | |
| 119 | 749 // check the hosts from the body against the content filter and uribl dnsbls |
| 94 | 750 // |
| 124 | 751 // |
| 752 bool check_hosts(mlfiPriv &priv, bool random, int limit, char *&msg, char *&host, int &ip, char *&found); | |
| 753 bool check_hosts(mlfiPriv &priv, bool random, int limit, char *&msg, char *&host, int &ip, char *&found) { | |
| 754 found = NULL; // normally ip address style | |
| 119 | 755 if (!priv.content_suffix && !priv.uribl_suffix) return false; // nothing to check |
| 94 | 756 CONFIG &dc = *priv.pc; |
| 757 string_set &hosts = priv.memory->get_hosts(); | |
| 758 string_set &ignore = *priv.content_host_ignore; | |
| 759 | |
| 760 int count = 0; | |
| 761 int cnt = hosts.size(); // number of hosts we could look at | |
| 762 int_set ips; | |
| 763 ns_map nameservers; | |
| 764 for (string_set::iterator i=hosts.begin(); i!=hosts.end(); i++) { | |
| 765 host = *i; // a reference into hosts, which will live until this smtp transaction is closed | |
| 766 | |
| 767 // don't bother looking up hosts on the ignore list | |
| 768 string_set::iterator j = ignore.find(host); | |
| 769 if (j != ignore.end()) continue; | |
| 770 | |
| 771 // try to only look at limit/cnt fraction of the available cnt host names in random mode | |
| 772 if ((cnt > limit) && (limit > 0) && random) { | |
| 773 int r = rand() % cnt; | |
| 774 if (r >= limit) { | |
| 775 if (debug_syslog > 2) { | |
| 776 char buf[maxlen]; | |
| 777 snprintf(buf, sizeof(buf), "host %s skipped", host); | |
| 778 my_syslog(&priv, buf); | |
| 779 } | |
| 780 continue; | |
| 781 } | |
| 782 } | |
| 783 count++; | |
| 784 ip = dns_interface(priv, host, true, &nameservers); | |
| 785 if (debug_syslog > 2) { | |
| 786 char buf[maxlen]; | |
| 787 if (ip) { | |
| 788 char adr[sizeof "255.255.255.255"]; | |
| 789 adr[0] = '\0'; | |
| 790 inet_ntop(AF_INET, (const u_char *)&ip, adr, sizeof(adr)); | |
| 791 snprintf(buf, sizeof(buf), "host %s found at %s", host, adr); | |
| 792 } | |
| 793 else { | |
| 794 snprintf(buf, sizeof(buf), "host %s not found", host); | |
| 795 } | |
| 796 my_syslog(&priv, buf); | |
| 797 } | |
| 798 if (ip) { | |
| 799 int_set::iterator i = ips.find(ip); | |
| 800 if (i == ips.end()) { | |
| 117 | 801 // we haven't looked this up yet |
| 94 | 802 ips.insert(ip); |
| 124 | 803 // check dnsbl style list |
| 804 if (priv.content_suffix && check_single(priv, ip, priv.content_suffix)) { | |
| 119 | 805 msg = priv.content_message; |
| 806 return true; | |
| 807 } | |
| 124 | 808 // Check uribl & surbl style list |
| 809 if (priv.uribl_suffix && check_uribl(priv, host, found)) { | |
| 119 | 810 msg = priv.uribl_message; |
| 811 return true; | |
| 812 } | |
| 94 | 813 } |
| 814 } | |
| 815 } | |
| 816 limit *= 4; // allow average of 3 ns per host name | |
| 817 for (ns_mapper::iterator i=nameservers.ns_ip.begin(); i!=nameservers.ns_ip.end(); i++) { | |
| 818 count++; | |
| 119 | 819 if ((count > limit) && (limit > 0)) return false; // too many name servers to check them all |
| 94 | 820 host = (*i).first; // a transient reference that needs to be replaced before we return it |
| 821 ip = (*i).second; | |
| 822 if (!ip) ip = dns_interface(priv, host, false, NULL); | |
| 823 if (debug_syslog > 2) { | |
| 824 char buf[maxlen]; | |
| 825 if (ip) { | |
| 826 char adr[sizeof "255.255.255.255"]; | |
| 827 adr[0] = '\0'; | |
| 828 inet_ntop(AF_INET, (const u_char *)&ip, adr, sizeof(adr)); | |
| 829 snprintf(buf, sizeof(buf), "ns %s found at %s", host, adr); | |
| 830 } | |
| 831 else { | |
| 832 snprintf(buf, sizeof(buf), "ns %s not found", host); | |
| 833 } | |
| 834 my_syslog(&priv, buf); | |
| 835 } | |
| 836 if (ip) { | |
| 837 int_set::iterator i = ips.find(ip); | |
| 838 if (i == ips.end()) { | |
| 839 ips.insert(ip); | |
| 119 | 840 if (check_single(priv, ip, priv.content_suffix)) { |
| 841 msg = priv.content_message; | |
| 94 | 842 string_map::iterator j = nameservers.ns_host.find(host); |
| 843 if (j != nameservers.ns_host.end()) { | |
| 844 char *refer = (*j).second; | |
| 845 char buf[maxlen]; | |
| 846 snprintf(buf, sizeof(buf), "%s with nameserver %s", refer, host); | |
| 847 host = register_string(hosts, buf); // put a copy into hosts, and return that reference | |
| 848 } | |
| 849 else { | |
| 850 host = register_string(hosts, host); // put a copy into hosts, and return that reference | |
| 851 } | |
| 852 return true; | |
| 853 } | |
| 854 } | |
| 855 } | |
| 856 } | |
| 857 return false; | |
| 858 } | |
| 859 | |
| 127 | 860 |
| 94 | 861 //////////////////////////////////////////////// |
| 127 | 862 // |
| 863 // this email address is passed in from sendmail, and will normally be | |
| 864 // enclosed in <>. I think older versions of sendmail supplied the <> | |
| 865 // wrapper if the mail client did not, but the current version does not do | |
| 866 // that. So the <> wrapper is now optional. It may have mixed case, just | |
| 867 // as the mail client sent it. We dup the string and convert the duplicate | |
| 868 // to lower case. | |
| 94 | 869 // |
| 870 char *to_lower_string(char *email); | |
| 871 char *to_lower_string(char *email) { | |
| 127 | 872 int n = strlen(email); |
| 873 if (*email == '<') { | |
| 874 // assume it also ends with > | |
| 875 n -= 2; | |
| 876 if (n < 1) return strdup(email); // return "<>" | |
| 877 email++; | |
| 878 } | |
| 879 char *key = strdup(email); | |
| 94 | 880 key[n] = '\0'; |
| 881 for (int i=0; i<n; i++) key[i] = tolower(key[i]); | |
| 882 return key; | |
| 883 } | |
| 884 | |
| 885 | |
| 886 //////////////////////////////////////////////// | |
| 887 // start of sendmail milter interfaces | |
| 888 // | |
| 889 sfsistat mlfi_connect(SMFICTX *ctx, char *hostname, _SOCK_ADDR *hostaddr) | |
| 890 { | |
| 891 // allocate some private memory | |
| 892 mlfiPriv *priv = new mlfiPriv; | |
| 893 if (hostaddr->sa_family == AF_INET) { | |
| 894 priv->ip = ((struct sockaddr_in *)hostaddr)->sin_addr.s_addr; | |
| 895 } | |
| 896 | |
| 897 // save the private data | |
| 898 smfi_setpriv(ctx, (void*)priv); | |
| 899 | |
| 900 // continue processing | |
| 901 return SMFIS_CONTINUE; | |
| 902 } | |
| 903 | |
| 904 sfsistat mlfi_envfrom(SMFICTX *ctx, char **from) | |
| 905 { | |
| 906 mlfiPriv &priv = *MLFIPRIV; | |
| 907 priv.mailaddr = to_lower_string(from[0]); | |
| 908 priv.authenticated = (smfi_getsymval(ctx, "{auth_authen}") != NULL); | |
| 909 return SMFIS_CONTINUE; | |
| 910 } | |
| 911 | |
| 912 sfsistat mlfi_envrcpt(SMFICTX *ctx, char **rcpt) | |
| 913 { | |
| 914 DNSBLP rejectlist = NULL; // list that caused the reject | |
| 915 mlfiPriv &priv = *MLFIPRIV; | |
| 916 CONFIG &dc = *priv.pc; | |
| 917 if (!priv.queueid) priv.queueid = strdup(smfi_getsymval(ctx, "i")); | |
| 918 char *rcptaddr = rcpt[0]; | |
| 919 char *loto = to_lower_string(rcptaddr); | |
| 920 CONTEXT &con = *(dc.find_context(loto)->find_context(priv.mailaddr)); | |
| 921 VERIFYP ver = con.find_verify(loto); | |
| 922 if (debug_syslog > 1) { | |
| 923 char buf[maxlen]; | |
| 924 char msg[maxlen]; | |
| 925 snprintf(msg, sizeof(msg), "from <%s> to <%s> using context %s", priv.mailaddr, loto, con.get_full_name(buf,maxlen)); | |
| 926 my_syslog(&priv, msg); | |
| 927 } | |
| 928 free(loto); | |
| 929 char *fromvalue = con.find_from(priv.mailaddr); | |
| 930 status st; | |
| 931 if (priv.authenticated) { | |
| 932 st = white; | |
| 933 } | |
| 934 else if (fromvalue == token_black) { | |
| 935 st = black; | |
| 936 } | |
| 937 else if (fromvalue == token_white) { | |
| 938 st = white; | |
| 939 } | |
| 940 else { | |
| 941 // check the dns based lists | |
| 942 st = (check_dnsbl(priv, con.get_dnsbl_list(), rejectlist)) ? reject : oksofar; | |
| 943 } | |
| 944 if (st == reject) { | |
| 945 // reject the recipient based on some dnsbl | |
| 946 char adr[sizeof "255.255.255.255"]; | |
| 947 adr[0] = '\0'; | |
| 948 inet_ntop(AF_INET, (const u_char *)&priv.ip, adr, sizeof(adr)); | |
| 949 char buf[maxlen]; | |
| 950 snprintf(buf, sizeof(buf), rejectlist->message, adr, adr); | |
| 951 smfi_setreply(ctx, "550", "5.7.1", buf); | |
| 952 return SMFIS_REJECT; | |
| 953 } | |
| 954 if (st == black) { | |
| 955 // reject the recipient based on blacklisting either from or to | |
| 956 smfi_setreply(ctx, "550", "5.7.1", "no such user"); | |
| 957 return SMFIS_REJECT; | |
| 958 } | |
| 959 if (ver && (st != white)) { | |
| 960 // try to verify this from/to pair of addresses since it is not explicitly whitelisted | |
| 961 char *loto = to_lower_string(rcptaddr); | |
| 962 bool rc = ver->ok(priv.mailaddr, loto); | |
| 963 free(loto); | |
| 964 if (!rc) { | |
| 965 smfi_setreply(ctx, "550", "5.7.1", "no such user"); | |
| 966 return SMFIS_REJECT; | |
| 967 } | |
| 968 } | |
| 969 // accept the recipient | |
| 970 if (!con.get_content_filtering()) st = white; | |
| 971 if (st == oksofar) { | |
| 972 // but remember the non-whites | |
| 973 priv.need_content_filter(rcptaddr, con); | |
| 974 priv.only_whites = false; | |
| 975 } | |
| 976 if (st == white) { | |
| 977 priv.have_whites = true; | |
| 978 } | |
| 979 return SMFIS_CONTINUE; | |
| 980 } | |
| 981 | |
| 982 sfsistat mlfi_body(SMFICTX *ctx, u_char *data, size_t len) | |
| 983 { | |
| 984 mlfiPriv &priv = *MLFIPRIV; | |
| 985 if (priv.authenticated) return SMFIS_CONTINUE; | |
| 986 if (priv.only_whites) return SMFIS_CONTINUE; | |
| 987 priv.scanner->scan(data, len); | |
| 988 return SMFIS_CONTINUE; | |
| 989 } | |
| 990 | |
| 991 sfsistat mlfi_eom(SMFICTX *ctx) | |
| 992 { | |
| 993 sfsistat rc; | |
| 994 mlfiPriv &priv = *MLFIPRIV; | |
| 995 CONFIG &dc = *priv.pc; | |
| 996 char *host = NULL; | |
| 997 int ip; | |
| 998 status st; | |
| 999 // process end of message | |
| 1000 if (priv.authenticated || priv.only_whites) rc = SMFIS_CONTINUE; | |
| 1001 else { | |
| 1002 // assert env_to not empty | |
| 1003 char buf[maxlen]; | |
| 1004 char *msg = NULL; | |
| 1005 string_set alive; | |
| 1006 bool random = false; | |
| 1007 int limit = 0; | |
| 1008 for (context_map::iterator i=priv.env_to.begin(); i!=priv.env_to.end(); i++) { | |
| 1009 char *rcpt = (*i).first; | |
| 1010 CONTEXT &con = *((*i).second); | |
| 1011 if (!con.acceptable_content(*priv.memory, msg)) { | |
| 1012 // bad html tags or excessive hosts | |
| 1013 smfi_delrcpt(ctx, rcpt); | |
| 1014 } | |
| 1015 else { | |
| 1016 alive.insert(rcpt); | |
| 1017 random |= con.get_host_random(); | |
| 1018 limit = max(limit, con.get_host_limit()); | |
| 1019 } | |
| 1020 } | |
| 1021 bool rejecting = alive.empty(); // if alive is empty, we must have set msg above in acceptable_content() | |
| 1022 if (!rejecting) { | |
| 124 | 1023 char *fmt, *found; |
| 1024 if (check_hosts(priv, random, limit, fmt, host, ip, found)) { | |
| 1025 if (found) { | |
| 1026 // uribl style | |
| 1027 snprintf(buf, sizeof(buf), fmt, host, found); | |
| 1028 } | |
| 1029 else { | |
| 1030 // dnsbl style | |
| 1031 char adr[sizeof "255.255.255.255"]; | |
| 1032 adr[0] = '\0'; | |
| 1033 inet_ntop(AF_INET, (const u_char *)&ip, adr, sizeof(adr)); | |
| 1034 snprintf(buf, sizeof(buf), fmt, host, adr); | |
| 1035 } | |
| 94 | 1036 msg = buf; |
| 1037 rejecting = true; | |
| 1038 } | |
| 1039 } | |
| 1040 if (!rejecting) { | |
| 1041 rc = SMFIS_CONTINUE; | |
| 1042 } | |
| 1043 else if (!priv.have_whites) { | |
| 1044 // can reject the entire message | |
| 1045 smfi_setreply(ctx, "550", "5.7.1", msg); | |
| 1046 rc = SMFIS_REJECT; | |
| 1047 } | |
| 1048 else { | |
| 1049 // need to accept it but remove the recipients that don't want it | |
| 1050 for (string_set::iterator i=alive.begin(); i!=alive.end(); i++) { | |
| 1051 char *rcpt = *i; | |
| 1052 smfi_delrcpt(ctx, rcpt); | |
| 1053 } | |
| 1054 rc = SMFIS_CONTINUE; | |
| 1055 } | |
| 1056 } | |
| 1057 // reset for a new message on the same connection | |
| 1058 mlfi_abort(ctx); | |
| 1059 return rc; | |
| 1060 } | |
| 1061 | |
| 1062 sfsistat mlfi_abort(SMFICTX *ctx) | |
| 1063 { | |
| 1064 mlfiPriv &priv = *MLFIPRIV; | |
| 1065 priv.reset(); | |
| 1066 return SMFIS_CONTINUE; | |
| 1067 } | |
| 1068 | |
| 1069 sfsistat mlfi_close(SMFICTX *ctx) | |
| 1070 { | |
| 1071 mlfiPriv *priv = MLFIPRIV; | |
| 1072 if (!priv) return SMFIS_CONTINUE; | |
| 1073 delete priv; | |
| 1074 smfi_setpriv(ctx, NULL); | |
| 1075 return SMFIS_CONTINUE; | |
| 1076 } | |
| 1077 | |
| 1078 struct smfiDesc smfilter = | |
| 1079 { | |
| 1080 "DNSBL", // filter name | |
| 1081 SMFI_VERSION, // version code -- do not change | |
| 1082 SMFIF_DELRCPT, // flags | |
| 1083 mlfi_connect, // connection info filter | |
| 1084 NULL, // SMTP HELO command filter | |
| 1085 mlfi_envfrom, // envelope sender filter | |
| 1086 mlfi_envrcpt, // envelope recipient filter | |
| 1087 NULL, // header filter | |
| 1088 NULL, // end of header | |
| 1089 mlfi_body, // body block filter | |
| 1090 mlfi_eom, // end of message | |
| 1091 mlfi_abort, // message aborted | |
| 1092 mlfi_close, // connection cleanup | |
| 1093 }; | |
| 1094 | |
| 1095 | |
| 1096 //////////////////////////////////////////////// | |
| 1097 // reload the config | |
| 1098 // | |
| 1099 CONFIG* new_conf(); | |
| 1100 CONFIG* new_conf() { | |
| 1101 CONFIG *newc = new CONFIG; | |
| 1102 pthread_mutex_lock(&config_mutex); | |
| 1103 newc->generation = generation++; | |
| 1104 pthread_mutex_unlock(&config_mutex); | |
| 1105 if (debug_syslog) { | |
| 1106 char buf[maxlen]; | |
| 1107 snprintf(buf, sizeof(buf), "loading configuration generation %d", newc->generation); | |
| 1108 my_syslog(buf); | |
| 1109 } | |
| 1110 if (load_conf(*newc, "dnsbl.conf")) { | |
| 1111 newc->load_time = time(NULL); | |
| 1112 return newc; | |
| 1113 } | |
| 1114 delete newc; | |
| 1115 return NULL; | |
| 1116 } | |
| 1117 | |
| 1118 | |
| 1119 //////////////////////////////////////////////// | |
| 1120 // thread to watch the old config files for changes | |
| 1121 // and reload when needed. we also cleanup old | |
| 1122 // configs whose reference count has gone to zero. | |
| 1123 // | |
| 1124 void* config_loader(void *arg); | |
| 1125 void* config_loader(void *arg) { | |
| 1126 typedef set<CONFIG *> configp_set; | |
| 1127 configp_set old_configs; | |
| 1128 while (loader_run) { | |
| 1129 sleep(180); // look for modifications every 3 minutes | |
| 1130 if (!loader_run) break; | |
| 1131 CONFIG &dc = *config; | |
| 1132 time_t then = dc.load_time; | |
| 1133 struct stat st; | |
| 1134 bool reload = false; | |
| 1135 for (string_set::iterator i=dc.config_files.begin(); i!=dc.config_files.end(); i++) { | |
| 1136 char *fn = *i; | |
| 1137 if (stat(fn, &st)) reload = true; // file disappeared | |
| 1138 else if (st.st_mtime > then) reload = true; // file modified | |
| 1139 if (reload) break; | |
| 1140 } | |
| 1141 if (reload) { | |
| 1142 CONFIG *newc = new_conf(); | |
| 1143 if (newc) { | |
| 1144 // replace the global config pointer | |
| 1145 pthread_mutex_lock(&config_mutex); | |
| 1146 CONFIG *old = config; | |
| 1147 config = newc; | |
| 1148 pthread_mutex_unlock(&config_mutex); | |
| 1149 if (old) old_configs.insert(old); | |
| 1150 } | |
| 1151 else { | |
| 1152 // failed to load new config | |
| 1153 my_syslog("failed to load new configuration"); | |
| 1154 system("echo 'failed to load new dnsbl configuration from /etc/dnsbl' | mail -s 'error in /etc/dnsbl configuration' root"); | |
| 1155 // update the load time on the current config to prevent complaining every 3 minutes | |
| 1156 dc.load_time = time(NULL); | |
| 1157 } | |
| 1158 } | |
| 1159 // now look for old configs with zero ref counts | |
| 1160 for (configp_set::iterator i=old_configs.begin(); i!=old_configs.end(); ) { | |
| 1161 CONFIG *old = *i; | |
| 1162 if (!old->reference_count) { | |
| 1163 if (debug_syslog) { | |
| 1164 char buf[maxlen]; | |
| 1165 snprintf(buf, sizeof(buf), "freeing memory for old configuration generation %d", old->generation); | |
| 1166 my_syslog(buf); | |
| 1167 } | |
| 1168 delete old; // destructor does all the work | |
| 1169 old_configs.erase(i++); | |
| 1170 } | |
| 1171 else i++; | |
| 1172 } | |
| 1173 } | |
| 1174 return NULL; | |
| 1175 } | |
| 1176 | |
| 1177 | |
| 1178 void usage(char *prog); | |
| 1179 void usage(char *prog) | |
| 1180 { | |
| 1181 fprintf(stderr, "Usage: %s [-d [level]] [-c] [-s] [-e from|to] -r port -p sm-sock-addr [-t timeout]\n", prog); | |
| 1182 fprintf(stderr, "where port is for the connection to our own dns resolver processes\n"); | |
| 1183 fprintf(stderr, " and should be local-domain-socket-file-name\n"); | |
| 1184 fprintf(stderr, "where sm-sock-addr is for the connection to sendmail\n"); | |
| 1185 fprintf(stderr, " and should be one of\n"); | |
| 1186 fprintf(stderr, " inet:port@ip-address\n"); | |
| 1187 fprintf(stderr, " local:local-domain-socket-file-name\n"); | |
| 1188 fprintf(stderr, "-c will load and dump the config to stdout\n"); | |
| 1189 fprintf(stderr, "-s will stress test the config loading code by repeating the load/free cycle\n"); | |
| 1190 fprintf(stderr, " in an infinte loop.\n"); | |
| 1191 fprintf(stderr, "-d will set the syslog message level, currently 0 to 3\n"); | |
| 1192 fprintf(stderr, "-e will print the results of looking up the from and to addresses in the\n"); | |
| 1193 fprintf(stderr, " current config. The | character is used to separate the from and to\n"); | |
| 1194 fprintf(stderr, " addresses in the argument to the -e switch\n"); | |
| 1195 } | |
| 1196 | |
| 1197 | |
| 1198 | |
| 1199 void setup_socket(char *sock); | |
| 1200 void setup_socket(char *sock) { | |
| 1201 unlink(sock); | |
| 1202 // sockaddr_un addr; | |
| 1203 // memset(&addr, '\0', sizeof addr); | |
| 1204 // addr.sun_family = AF_UNIX; | |
| 1205 // strncpy(addr.sun_path, sock, sizeof(addr.sun_path)-1); | |
| 1206 // int s = socket(AF_UNIX, SOCK_STREAM, 0); | |
| 1207 // bind(s, (sockaddr*)&addr, sizeof(addr)); | |
| 1208 // close(s); | |
| 1209 } | |
| 1210 | |
| 1211 | |
| 1212 /* | |
| 1213 * The signal handler function -- only gets called when a SIGCHLD | |
| 1214 * is received, ie when a child terminates | |
| 1215 */ | |
| 1216 void sig_chld(int signo) | |
| 1217 { | |
| 1218 int status; | |
| 1219 /* Wait for any child without blocking */ | |
| 1220 while (waitpid(-1, &status, WNOHANG) > 0) { | |
| 1221 // ignore child exit status, we only do this to cleanup zombies | |
| 1222 } | |
| 1223 } | |
| 1224 | |
| 1225 | |
| 1226 int main(int argc, char**argv) | |
| 1227 { | |
| 1228 token_init(); | |
| 1229 bool check = false; | |
| 1230 bool stress = false; | |
| 1231 bool setconn = false; | |
| 1232 bool setreso = false; | |
| 1233 char *email = NULL; | |
| 1234 int c; | |
| 1235 const char *args = "r:p:t:e:d:chs"; | |
| 1236 extern char *optarg; | |
| 1237 | |
| 1238 // Process command line options | |
| 1239 while ((c = getopt(argc, argv, args)) != -1) { | |
| 1240 switch (c) { | |
| 1241 case 'r': | |
| 1242 if (optarg == NULL || *optarg == '\0') { | |
| 1243 fprintf(stderr, "Illegal resolver socket: %s\n", optarg); | |
| 1244 exit(EX_USAGE); | |
| 1245 } | |
| 1246 resolver_port = strdup(optarg); | |
| 1247 setup_socket(resolver_port); | |
| 1248 setreso = true; | |
| 1249 break; | |
| 1250 | |
| 1251 case 'p': | |
| 1252 if (optarg == NULL || *optarg == '\0') { | |
| 1253 fprintf(stderr, "Illegal sendmail socket: %s\n", optarg); | |
| 1254 exit(EX_USAGE); | |
| 1255 } | |
| 1256 if (smfi_setconn(optarg) == MI_FAILURE) { | |
| 1257 fprintf(stderr, "smfi_setconn failed\n"); | |
| 1258 exit(EX_SOFTWARE); | |
| 1259 } | |
| 1260 if (strncasecmp(optarg, "unix:", 5) == 0) setup_socket(optarg + 5); | |
| 1261 else if (strncasecmp(optarg, "local:", 6) == 0) setup_socket(optarg + 6); | |
| 1262 setconn = true; | |
| 1263 break; | |
| 1264 | |
| 1265 case 't': | |
| 1266 if (optarg == NULL || *optarg == '\0') { | |
| 1267 fprintf(stderr, "Illegal timeout: %s\n", optarg); | |
| 1268 exit(EX_USAGE); | |
| 1269 } | |
| 1270 if (smfi_settimeout(atoi(optarg)) == MI_FAILURE) { | |
| 1271 fprintf(stderr, "smfi_settimeout failed\n"); | |
| 1272 exit(EX_SOFTWARE); | |
| 1273 } | |
| 1274 break; | |
| 1275 | |
| 1276 case 'e': | |
| 1277 if (email) free(email); | |
| 1278 email = strdup(optarg); | |
| 1279 break; | |
| 1280 | |
| 1281 case 'c': | |
| 1282 check = true; | |
| 1283 break; | |
| 1284 | |
| 1285 case 's': | |
| 1286 stress = true; | |
| 1287 break; | |
| 1288 | |
| 1289 case 'd': | |
| 1290 if (optarg == NULL || *optarg == '\0') debug_syslog = 1; | |
| 1291 else debug_syslog = atoi(optarg); | |
| 1292 break; | |
| 1293 | |
| 1294 case 'h': | |
| 1295 default: | |
| 1296 usage(argv[0]); | |
| 1297 exit(EX_USAGE); | |
| 1298 } | |
| 1299 } | |
| 1300 | |
| 1301 if (check) { | |
| 1302 use_syslog = false; | |
| 1303 debug_syslog = 10; | |
| 1304 CONFIG *conf = new_conf(); | |
| 1305 if (conf) { | |
| 1306 conf->dump(); | |
| 1307 delete conf; | |
| 1308 return 0; | |
| 1309 } | |
| 1310 else { | |
| 1311 return 1; // config failed to load | |
| 1312 } | |
| 1313 } | |
| 1314 | |
| 1315 if (stress) { | |
| 1316 fprintf(stdout, "stress testing\n"); | |
| 1317 while (1) { | |
| 1318 for (int i=0; i<10; i++) { | |
| 1319 CONFIG *conf = new_conf(); | |
| 1320 if (conf) delete conf; | |
| 1321 } | |
| 1322 fprintf(stdout, "."); | |
| 1323 fflush(stdout); | |
| 1324 sleep(1); | |
| 1325 } | |
| 1326 } | |
| 1327 | |
| 1328 if (email) { | |
| 1329 char *x = strchr(email, '|'); | |
| 1330 if (x) { | |
| 1331 *x = '\0'; | |
| 1332 char *from = strdup(email); | |
| 1333 char *to = strdup(x+1); | |
| 1334 use_syslog = false; | |
| 1335 CONFIG *conf = new_conf(); | |
| 1336 if (conf) { | |
| 1337 CONTEXTP con = conf->find_context(to); | |
| 1338 char buf[maxlen]; | |
| 1339 fprintf(stdout, "envelope to <%s> finds context %s\n", to, con->get_full_name(buf,maxlen)); | |
| 1340 CONTEXTP fc = con->find_context(from); | |
| 1341 fprintf(stdout, "envelope from <%s> finds context %s\n", from, fc->get_full_name(buf,maxlen)); | |
| 1342 char *st = fc->find_from(from); | |
| 1343 fprintf(stdout, "envelope from <%s> finds status %s\n", from, st); | |
| 1344 delete conf; | |
| 1345 } | |
| 1346 } | |
| 1347 return 0; | |
| 1348 } | |
| 1349 | |
| 1350 if (!setconn) { | |
| 1351 fprintf(stderr, "%s: Missing required -p argument\n", argv[0]); | |
| 1352 usage(argv[0]); | |
| 1353 exit(EX_USAGE); | |
| 1354 } | |
| 1355 | |
| 1356 if (!setreso) { | |
| 1357 fprintf(stderr, "%s: Missing required -r argument\n", argv[0]); | |
| 1358 usage(argv[0]); | |
| 1359 exit(EX_USAGE); | |
| 1360 } | |
| 1361 | |
| 1362 if (smfi_register(smfilter) == MI_FAILURE) { | |
| 1363 fprintf(stderr, "smfi_register failed\n"); | |
| 1364 exit(EX_UNAVAILABLE); | |
| 1365 } | |
| 1366 | |
| 1367 // switch to background mode | |
| 1368 if (daemon(1,0) < 0) { | |
| 1369 fprintf(stderr, "daemon() call failed\n"); | |
| 1370 exit(EX_UNAVAILABLE); | |
| 1371 } | |
| 1372 | |
| 1373 // write the pid | |
| 1374 const char *pidpath = "/var/run/dnsbl.pid"; | |
| 1375 unlink(pidpath); | |
| 1376 FILE *f = fopen(pidpath, "w"); | |
| 1377 if (f) { | |
| 1378 #ifdef linux | |
| 1379 // from a comment in the DCC source code: | |
| 1380 // Linux threads are broken. Signals given the | |
| 1381 // original process are delivered to only the | |
| 1382 // thread that happens to have that PID. The | |
| 1383 // sendmail libmilter thread that needs to hear | |
| 1384 // SIGINT and other signals does not, and that breaks | |
| 1385 // scripts that need to stop milters. | |
| 1386 // However, signaling the process group works. | |
| 1387 fprintf(f, "-%d\n", (u_int)getpgrp()); | |
| 1388 #else | |
| 1389 fprintf(f, "%d\n", (u_int)getpid()); | |
| 1390 #endif | |
| 1391 fclose(f); | |
| 1392 } | |
| 1393 | |
| 1394 // initialize the thread sync objects | |
| 1395 pthread_mutex_init(&config_mutex, 0); | |
| 1396 pthread_mutex_init(&syslog_mutex, 0); | |
| 1397 pthread_mutex_init(&resolve_mutex, 0); | |
| 1398 pthread_mutex_init(&fd_pool_mutex, 0); | |
| 1399 | |
| 1400 // drop root privs | |
| 1401 struct passwd *pw = getpwnam("dnsbl"); | |
| 1402 if (pw) { | |
| 1403 if (setgid(pw->pw_gid) == -1) { | |
| 1404 my_syslog("failed to switch to group dnsbl"); | |
| 1405 } | |
| 1406 if (setuid(pw->pw_uid) == -1) { | |
| 1407 my_syslog("failed to switch to user dnsbl"); | |
| 1408 } | |
| 1409 } | |
| 1410 | |
| 1411 // load the initial config | |
| 1412 config = new_conf(); | |
| 1413 if (!config) { | |
| 1414 my_syslog("failed to load initial configuration, quitting"); | |
| 1415 exit(1); | |
| 1416 } | |
| 1417 | |
| 1418 // fork off the resolver listener process | |
| 1419 pid_t child = fork(); | |
| 1420 if (child < 0) { | |
| 1421 my_syslog("failed to create resolver listener process"); | |
| 1422 exit(0); | |
| 1423 } | |
| 1424 if (child == 0) { | |
| 1425 // we are the child - dns resolver listener process | |
| 1426 resolver_socket = socket(AF_UNIX, SOCK_STREAM, 0); | |
| 1427 if (resolver_socket < 0) { | |
| 1428 my_syslog("child failed to create resolver socket"); | |
| 1429 exit(0); // failed | |
| 1430 } | |
| 1431 sockaddr_un server; | |
| 1432 memset(&server, '\0', sizeof(server)); | |
| 1433 server.sun_family = AF_UNIX; | |
| 1434 strncpy(server.sun_path, resolver_port, sizeof(server.sun_path)-1); | |
| 1435 //try to bind the address to the socket. | |
| 1436 if (bind(resolver_socket, (sockaddr *)&server, sizeof(server)) < 0) { | |
| 1437 // bind failed | |
| 1438 shutdown(resolver_socket, SHUT_RDWR); | |
| 1439 close(resolver_socket); | |
| 1440 my_syslog("child failed to bind resolver socket"); | |
| 1441 exit(0); // failed | |
| 1442 } | |
| 1443 //listen on the socket. | |
| 1444 if (listen(resolver_socket, 10) < 0) { | |
| 1445 // listen failed | |
| 1446 shutdown(resolver_socket, SHUT_RDWR); | |
| 1447 close(resolver_socket); | |
| 1448 my_syslog("child failed to listen to resolver socket"); | |
| 1449 exit(0); // failed | |
| 1450 } | |
| 1451 // setup sigchld handler to prevent zombies | |
| 1452 struct sigaction act; | |
| 1453 act.sa_handler = sig_chld; // Assign sig_chld as our SIGCHLD handler | |
| 1454 sigemptyset(&act.sa_mask); // We don't want to block any other signals in this example | |
| 1455 act.sa_flags = SA_NOCLDSTOP; // only want children that have terminated | |
| 1456 if (sigaction(SIGCHLD, &act, NULL) < 0) { | |
| 1457 my_syslog("child failed to setup SIGCHLD handler"); | |
| 1458 exit(0); // failed | |
| 1459 } | |
| 1460 while (true) { | |
| 1461 sockaddr_un client; | |
| 1462 socklen_t clientlen = sizeof(client); | |
| 1463 int s = accept(resolver_socket, (sockaddr *)&client, &clientlen); | |
| 1464 if (s > 0) { | |
| 1465 // accept worked, it did not get cancelled before we could accept it | |
| 1466 // fork off a process to handle this connection | |
| 1467 int newchild = fork(); | |
| 1468 if (newchild == 0) { | |
| 1469 // this is the worker process | |
| 1470 // child does not need the listening socket | |
| 1471 close(resolver_socket); | |
| 1472 process_resolver_requests(s); | |
| 1473 exit(0); | |
| 1474 } | |
| 1475 else { | |
| 1476 // this is the parent | |
| 1477 // parent does not need the accepted socket | |
| 1478 close(s); | |
| 1479 } | |
| 1480 } | |
| 1481 } | |
| 1482 exit(0); // make sure we don't fall thru. | |
| 1483 } | |
| 1484 else { | |
| 1485 sleep(2); // allow child to get started | |
| 1486 } | |
| 1487 | |
| 1488 // only create threads after the fork() in daemon | |
| 1489 pthread_t tid; | |
| 1490 if (pthread_create(&tid, 0, config_loader, 0)) | |
| 1491 my_syslog("failed to create config loader thread"); | |
| 1492 if (pthread_detach(tid)) | |
| 1493 my_syslog("failed to detach config loader thread"); | |
| 1494 if (pthread_create(&tid, 0, verify_closer, 0)) | |
| 1495 my_syslog("failed to create verify closer thread"); | |
| 1496 if (pthread_detach(tid)) | |
| 1497 my_syslog("failed to detach verify closer thread"); | |
| 1498 | |
| 1499 time_t starting = time(NULL); | |
| 1500 int rc = smfi_main(); | |
| 1501 if ((rc != MI_SUCCESS) && (time(NULL) > starting+5*60)) { | |
| 1502 my_syslog("trying to restart after smfi_main()"); | |
| 1503 loader_run = false; // eventually the config loader thread will terminate | |
| 1504 execvp(argv[0], argv); | |
| 1505 } | |
| 1506 exit((rc == MI_SUCCESS) ? 0 : EX_UNAVAILABLE); | |
| 1507 } | |
| 1508 |