Mercurial > dnsbl
annotate src/dnsbl.cpp @ 141:6256cab02248
cleanup smtp rate limit code
| author | carl |
|---|---|
| date | Wed, 27 Sep 2006 08:11:38 -0700 |
| parents | 4028de9b46dd |
| children | b82e00146672 |
| 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; | |
| 136 | 89 pthread_mutex_t rate_mutex; |
| 94 | 90 |
| 91 std::set<int> fd_pool; | |
| 136 | 92 int NULL_SOCKET = -1; |
| 93 const time_t ERROR_SOCKET_TIME = 60; // number of seconds between attempts to open a socket to the dns resolver process | |
| 94 char *resolver_port = NULL; // unix domain socket to talk to the dns resolver process | |
| 95 int resolver_socket = NULL_SOCKET; // socket used to listen for resolver requests | |
| 96 time_t last_error_time; | |
| 97 int resolver_sock_count = 0; // protected with fd_pool_mutex | |
| 98 int resolver_pool_size = 0; // protected with fd_pool_mutex | |
| 99 rcpt_rates rcpt_counts; // protected with rate_mutex | |
| 94 | 100 |
| 101 | |
| 102 struct ns_map { | |
| 103 // all the strings are owned by the keys/values in the ns_host string map | |
| 104 string_map ns_host; // nameserver name -> host name that uses this name server | |
| 105 ns_mapper ns_ip; // nameserver name -> ip address of the name server | |
| 106 ~ns_map(); | |
| 107 void add(char *name, char *refer); | |
| 108 }; | |
| 109 | |
| 110 | |
| 111 ns_map::~ns_map() { | |
| 112 for (string_map::iterator i=ns_host.begin(); i!=ns_host.end(); i++) { | |
| 113 char *x = (*i).first; | |
| 114 char *y = (*i).second; | |
| 115 free(x); | |
| 116 free(y); | |
| 117 } | |
| 118 ns_ip.clear(); | |
| 119 ns_host.clear(); | |
| 120 } | |
| 121 | |
| 122 | |
| 123 void ns_map::add(char *name, char *refer) { | |
| 124 string_map::iterator i = ns_host.find(name); | |
| 125 if (i != ns_host.end()) return; | |
| 126 char *x = strdup(name); | |
| 127 char *y = strdup(refer); | |
| 128 ns_ip[x] = 0; | |
| 129 ns_host[x] = y; | |
| 130 | |
| 131 } | |
| 132 | |
| 133 // packed structure to allow a single socket write to dump the | |
| 134 // length and the following answer. The packing attribute is gcc specific. | |
| 135 struct glommer { | |
| 136 int length; | |
| 137 #ifdef NS_PACKETSZ | |
| 115 | 138 u_char answer[NS_PACKETSZ*4]; // with a resolver, we return resolver answers |
| 94 | 139 #else |
| 140 int answer; // without a resolver, we return a single ip4 address, 0 == no answer | |
| 141 #endif | |
| 142 } __attribute__ ((packed)); | |
| 143 | |
| 144 | |
| 145 //////////////////////////////////////////////// | |
| 136 | 146 // helper to manipulate recipient counts |
| 147 // | |
| 148 int incr_rcpt_count(char *user); | |
| 149 int incr_rcpt_count(char *user) { | |
| 150 pthread_mutex_lock(&rate_mutex); | |
| 151 rcpt_rates::iterator i = rcpt_counts.find(user); | |
| 138 | 152 int c = 1; |
| 153 if (i == rcpt_counts.end()) { | |
| 154 user = strdup(user); | |
| 155 rcpt_counts[user] = c; | |
| 156 } | |
| 157 else { | |
| 139 | 158 c = ++((*i).second); |
| 138 | 159 } |
| 136 | 160 pthread_mutex_unlock(&rate_mutex); |
| 161 return c; | |
| 162 } | |
| 163 | |
| 164 //////////////////////////////////////////////// | |
| 94 | 165 // helper to discard the strings held by a context_map |
| 166 // | |
| 167 void discard(context_map &cm); | |
| 168 void discard(context_map &cm) { | |
| 169 for (context_map::iterator i=cm.begin(); i!=cm.end(); i++) { | |
| 170 char *x = (*i).first; | |
| 171 free(x); | |
| 172 } | |
| 173 cm.clear(); | |
| 174 } | |
| 175 | |
| 176 | |
| 177 //////////////////////////////////////////////// | |
| 178 // helper to register a string in a context_map | |
| 179 // | |
| 180 void register_string(context_map &cm, char *name, CONTEXT *con); | |
| 181 void register_string(context_map &cm, char *name, CONTEXT *con) { | |
| 182 context_map::iterator i = cm.find(name); | |
| 183 if (i != cm.end()) return; | |
| 184 char *x = strdup(name); | |
| 185 cm[x] = con; | |
| 186 } | |
| 187 | |
| 188 | |
| 189 //////////////////////////////////////////////// | |
| 190 // disconnect the fd from the dns resolver process | |
| 191 // | |
| 192 void my_disconnect(int sock, bool decrement = true); | |
| 193 void my_disconnect(int sock, bool decrement) { | |
| 194 if (sock != NULL_SOCKET) { | |
| 195 if (decrement) { | |
| 196 pthread_mutex_lock(&fd_pool_mutex); | |
| 197 resolver_sock_count--; | |
| 198 pthread_mutex_unlock(&fd_pool_mutex); | |
| 199 } | |
| 200 shutdown(sock, SHUT_RDWR); | |
| 201 close(sock); | |
| 202 } | |
| 203 } | |
| 204 | |
| 205 | |
| 206 //////////////////////////////////////////////// | |
| 207 // return fd connected to the dns resolver process | |
| 208 // | |
| 209 int my_connect(); | |
| 210 int my_connect() { | |
| 211 // if we have had recent errors, don't even try to open the socket | |
|
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212 if ((time(NULL) - last_error_time) < ERROR_SOCKET_TIME) return NULL_SOCKET; |
| 94 | 213 |
| 214 // nothing recent, maybe this time it will work | |
| 215 int sock = NULL_SOCKET; | |
| 216 sockaddr_un server; | |
| 217 memset(&server, '\0', sizeof(server)); | |
| 218 server.sun_family = AF_UNIX; | |
| 219 strncpy(server.sun_path, resolver_port, sizeof(server.sun_path)-1); | |
| 220 sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
| 221 if (sock != NULL_SOCKET) { | |
| 222 bool rc = (connect(sock, (sockaddr *)&server, sizeof(server)) == 0); | |
| 223 if (!rc) { | |
| 224 my_disconnect(sock, false); | |
| 225 sock = NULL_SOCKET; | |
|
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226 last_error_time = time(NULL); |
| 94 | 227 } |
| 228 } | |
|
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229 else last_error_time = time(NULL); |
| 94 | 230 if (sock != NULL_SOCKET) { |
| 231 pthread_mutex_lock(&fd_pool_mutex); | |
| 232 resolver_sock_count++; | |
| 233 pthread_mutex_unlock(&fd_pool_mutex); | |
| 234 } | |
| 235 return sock; | |
| 236 } | |
| 237 | |
| 238 | |
| 239 mlfiPriv::mlfiPriv() { | |
| 240 pthread_mutex_lock(&config_mutex); | |
| 241 pc = config; | |
| 242 pc->reference_count++; | |
| 243 pthread_mutex_unlock(&config_mutex); | |
| 244 get_fd(); | |
| 245 ip = 0; | |
| 246 mailaddr = NULL; | |
| 247 queueid = NULL; | |
| 136 | 248 authenticated = NULL; |
| 94 | 249 have_whites = false; |
| 250 only_whites = true; | |
| 251 memory = NULL; | |
| 252 scanner = NULL; | |
| 253 content_suffix = NULL; | |
| 254 content_message = NULL; | |
| 119 | 255 uribl_suffix = NULL; |
| 256 uribl_message = NULL; | |
| 94 | 257 content_host_ignore = NULL; |
| 258 } | |
| 259 | |
| 260 mlfiPriv::~mlfiPriv() { | |
| 261 return_fd(); | |
| 262 pthread_mutex_lock(&config_mutex); | |
| 263 pc->reference_count--; | |
| 264 pthread_mutex_unlock(&config_mutex); | |
| 265 reset(true); | |
| 266 } | |
| 267 | |
| 268 void mlfiPriv::reset(bool final) { | |
| 136 | 269 if (mailaddr) free(mailaddr); |
| 270 if (queueid) free(queueid); | |
| 271 if (authenticated) free(authenticated); | |
| 94 | 272 discard(env_to); |
| 273 if (memory) delete memory; | |
| 274 if (scanner) delete scanner; | |
| 275 if (!final) { | |
| 276 mailaddr = NULL; | |
| 277 queueid = NULL; | |
| 136 | 278 authenticated = NULL; |
| 94 | 279 have_whites = false; |
| 280 only_whites = true; | |
| 281 memory = NULL; | |
| 282 scanner = NULL; | |
| 283 content_suffix = NULL; | |
| 284 content_message = NULL; | |
| 119 | 285 uribl_suffix = NULL; |
| 286 uribl_message = NULL; | |
| 94 | 287 content_host_ignore = NULL; |
| 288 } | |
| 289 } | |
| 290 | |
| 291 void mlfiPriv::get_fd() { | |
| 292 err = true; | |
| 293 fd = NULL_SOCKET; | |
| 294 int result = pthread_mutex_lock(&fd_pool_mutex); | |
| 295 if (!result) { | |
| 296 std::set<int>::iterator i; | |
| 297 i = fd_pool.begin(); | |
| 298 if (i != fd_pool.end()) { | |
| 299 // have at least one fd in the pool | |
| 300 err = false; | |
| 301 fd = *i; | |
| 302 fd_pool.erase(fd); | |
| 303 resolver_pool_size--; | |
| 304 pthread_mutex_unlock(&fd_pool_mutex); | |
| 305 } | |
| 306 else { | |
| 307 // pool is empty, get a new fd | |
| 308 pthread_mutex_unlock(&fd_pool_mutex); | |
| 309 fd = my_connect(); | |
| 310 err = (fd == NULL_SOCKET); | |
| 311 } | |
| 312 } | |
| 313 else { | |
| 314 // cannot lock the pool, just get a new fd | |
| 315 fd = my_connect(); | |
| 316 err = (fd == NULL_SOCKET); | |
| 317 } | |
| 318 } | |
| 319 | |
| 320 void mlfiPriv::return_fd() { | |
| 321 if (err) { | |
| 322 // this fd got a socket error, so close it, rather than returning it to the pool | |
| 323 my_disconnect(fd); | |
| 324 } | |
| 325 else { | |
| 326 int result = pthread_mutex_lock(&fd_pool_mutex); | |
| 327 if (!result) { | |
| 328 if ((resolver_sock_count > resolver_pool_size*5) || (resolver_pool_size < 5)) { | |
| 329 // return the fd to the pool | |
| 330 fd_pool.insert(fd); | |
| 331 resolver_pool_size++; | |
| 332 pthread_mutex_unlock(&fd_pool_mutex); | |
| 333 } | |
| 334 else { | |
| 335 // more than 20% of the open resolver sockets are in the pool, and the | |
| 336 // pool as at least 5 sockets. that is enough, so just close this one. | |
| 337 pthread_mutex_unlock(&fd_pool_mutex); | |
| 338 my_disconnect(fd); | |
| 339 } | |
| 340 } | |
| 341 else { | |
| 342 // could not lock the pool, so just close the fd | |
| 343 my_disconnect(fd); | |
| 344 } | |
| 345 } | |
| 346 } | |
| 347 | |
| 348 int mlfiPriv::my_write(char *buf, int len) { | |
| 349 if (err) return 0; | |
| 350 int rs = 0; | |
| 351 while (len) { | |
| 352 int ws = write(fd, buf, len); | |
| 353 if (ws > 0) { | |
| 354 rs += ws; | |
| 355 len -= ws; | |
| 356 buf += ws; | |
| 357 } | |
| 358 else { | |
| 359 // peer closed the socket! | |
| 360 rs = 0; | |
| 361 err = true; | |
| 362 break; | |
| 363 } | |
| 364 } | |
| 365 return rs; | |
| 366 } | |
| 367 | |
| 368 int mlfiPriv::my_read(char *buf, int len) { | |
| 369 if (err) return 0; | |
| 370 int rs = 0; | |
| 134 | 371 while (len) { |
| 94 | 372 int ws = read(fd, buf, len); |
| 373 if (ws > 0) { | |
| 374 rs += ws; | |
| 375 len -= ws; | |
| 376 buf += ws; | |
| 377 } | |
| 378 else { | |
| 379 // peer closed the socket! | |
| 380 rs = 0; | |
| 381 err = true; | |
| 382 break; | |
| 383 } | |
| 384 } | |
| 385 return rs; | |
| 386 } | |
| 387 | |
| 388 void mlfiPriv::need_content_filter(char *rcpt, CONTEXT &con) { | |
| 389 register_string(env_to, rcpt, &con); | |
| 390 if (!memory) { | |
| 391 // first recipient that needs content filtering sets all | |
| 392 // the content filtering parameters | |
| 117 | 393 memory = new recorder(this, con.get_html_tags(), con.get_content_tlds(), con.get_content_cctlds()); |
| 94 | 394 scanner = new url_scanner(memory); |
| 395 content_suffix = con.get_content_suffix(); | |
| 396 content_message = con.get_content_message(); | |
| 119 | 397 uribl_suffix = con.get_uribl_suffix(); |
| 398 uribl_message = con.get_uribl_message(); | |
| 94 | 399 content_host_ignore = &con.get_content_host_ignore(); |
| 400 } | |
| 401 } | |
| 402 | |
| 403 #define MLFIPRIV ((struct mlfiPriv *) smfi_getpriv(ctx)) | |
| 404 | |
| 405 | |
| 406 //////////////////////////////////////////////// | |
| 407 // syslog a message | |
| 408 // | |
| 409 void my_syslog(mlfiPriv *priv, char *text) { | |
| 410 char buf[maxlen]; | |
| 411 if (priv) { | |
| 412 snprintf(buf, sizeof(buf), "%s: %s", priv->queueid, text); | |
| 413 text = buf; | |
| 414 } | |
| 415 if (use_syslog) { | |
| 416 pthread_mutex_lock(&syslog_mutex); | |
| 417 if (!syslog_opened) { | |
| 418 openlog("dnsbl", LOG_PID, LOG_MAIL); | |
| 419 syslog_opened = true; | |
| 420 } | |
| 421 syslog(LOG_NOTICE, "%s", text); | |
| 422 pthread_mutex_unlock(&syslog_mutex); | |
| 423 } | |
| 424 else { | |
| 425 printf("%s \n", text); | |
| 426 } | |
| 427 } | |
| 428 | |
| 429 void my_syslog(char *text) { | |
| 430 my_syslog(NULL, text); | |
| 431 } | |
| 432 | |
| 433 | |
| 434 //////////////////////////////////////////////// | |
| 435 // read a resolver request from the socket, process it, and | |
| 436 // write the result back to the socket. | |
| 437 | |
| 438 void process_resolver_requests(int socket); | |
| 439 void process_resolver_requests(int socket) { | |
| 440 #ifdef NS_MAXDNAME | |
| 441 char question[NS_MAXDNAME]; | |
| 442 #else | |
| 443 char question[1000]; | |
| 444 #endif | |
| 445 glommer glom; | |
| 446 | |
| 447 int maxq = sizeof(question); | |
| 448 while (true) { | |
| 449 // read a question | |
| 450 int rs = 0; | |
| 451 while (rs < maxq) { | |
| 452 int ns = read(socket, question+rs, maxq-rs); | |
| 453 if (ns > 0) { | |
| 454 rs += ns; | |
| 455 if (question[rs-1] == '\0') { | |
| 456 // last byte read was the null terminator, we are done | |
| 457 break; | |
| 458 } | |
| 459 } | |
| 460 else { | |
| 461 // peer closed the socket | |
| 462 #ifdef RESOLVER_DEBUG | |
| 463 my_syslog("process_resolver_requests() peer closed socket while reading question"); | |
| 464 #endif | |
| 465 shutdown(socket, SHUT_RDWR); | |
| 466 close(socket); | |
| 467 return; | |
| 468 } | |
| 469 } | |
| 470 question[rs-1] = '\0'; // ensure null termination | |
| 471 | |
| 472 // find the answer | |
| 473 #ifdef NS_PACKETSZ | |
| 474 #ifdef RESOLVER_DEBUG | |
| 475 char text[1000]; | |
| 476 snprintf(text, sizeof(text), "process_resolver_requests() has a question %s", question); | |
| 477 my_syslog(text); | |
| 478 #endif | |
| 479 glom.length = res_search(question, ns_c_in, ns_t_a, glom.answer, sizeof(glom.answer)); | |
| 480 if (glom.length < 0) glom.length = 0; // represent all errors as zero length answers | |
| 481 #else | |
| 482 glom.length = sizeof(glom.answer); | |
| 483 glom.answer = 0; | |
| 484 struct hostent *host = gethostbyname(question); | |
| 485 if (host && (host->h_addrtype == AF_INET)) { | |
| 486 memcpy(&glom.answer, host->h_addr, sizeof(glom.answer)); | |
| 487 } | |
| 488 #endif | |
| 489 | |
| 490 // write the answer | |
| 491 char *buf = (char *)&glom; | |
| 492 int len = glom.length + sizeof(glom.length); | |
| 493 #ifdef RESOLVER_DEBUG | |
| 494 snprintf(text, sizeof(text), "process_resolver_requests() writing answer length %d for total %d", glom.length, len); | |
| 495 my_syslog(text); | |
| 496 #endif | |
| 497 int ws = 0; | |
| 498 while (len > ws) { | |
| 499 int ns = write(socket, buf+ws, len-ws); | |
| 500 if (ns > 0) { | |
| 501 ws += ns; | |
| 502 } | |
| 503 else { | |
| 504 // peer closed the socket! | |
| 505 #ifdef RESOLVER_DEBUG | |
| 506 my_syslog("process_resolver_requests() peer closed socket while writing answer"); | |
| 507 #endif | |
| 508 shutdown(socket, SHUT_RDWR); | |
| 509 close(socket); | |
| 510 return; | |
| 511 } | |
| 512 } | |
| 513 } | |
| 514 } | |
| 515 | |
| 516 | |
| 517 //////////////////////////////////////////////// | |
| 518 // ask a dns question and get an A record answer - we don't try | |
| 519 // very hard, just using the default resolver retry settings. | |
| 520 // If we cannot get an answer, we just accept the mail. | |
| 521 // | |
| 522 // | |
| 523 int dns_interface(mlfiPriv &priv, char *question, bool maybe_ip, ns_map *nameservers); | |
| 524 int dns_interface(mlfiPriv &priv, char *question, bool maybe_ip, ns_map *nameservers) { | |
| 525 // this part can be done without locking the resolver mutex. Each | |
| 526 // milter thread is talking over its own socket to a separate resolver | |
| 527 // process, which does the actual dns resolution. | |
| 528 if (priv.err) return 0; // cannot ask more questions on this socket. | |
| 134 | 529 if (maybe_ip) { |
| 530 // might be a bare ip address, try this first to avoid dns lookups that may not be needed | |
| 531 in_addr ip; | |
| 532 if (inet_aton(question, &ip)) { | |
| 533 return (int)ip.s_addr; | |
| 534 } | |
| 535 } | |
| 536 int n = strlen(question); | |
| 537 if (question[n-1] == '.') { | |
| 538 priv.my_write(question, n+1); // write the question including the null terminator | |
| 539 } | |
| 540 else { | |
| 541 priv.my_write(question, n); // write the question | |
| 542 priv.my_write(".", 2); // and the fully qualified . terminator and null string terminator | |
| 543 } | |
| 94 | 544 glommer glom; |
| 545 char *buf = (char *)&glom; | |
| 546 priv.my_read(buf, sizeof(glom.length)); | |
| 547 buf += sizeof(glom.length); | |
| 548 #ifdef RESOLVER_DEBUG | |
| 549 char text[1000]; | |
| 550 snprintf(text, sizeof(text), "dns_interface() wrote question %s and has answer length %d", question, glom.length); | |
| 551 my_syslog(text); | |
| 552 #endif | |
| 553 if ((glom.length < 0) || (glom.length > sizeof(glom.answer))) { | |
| 554 priv.err = true; | |
| 555 return 0; // cannot process overlarge answers | |
| 556 } | |
| 557 priv.my_read(buf, glom.length); | |
| 558 | |
| 559 #ifdef NS_PACKETSZ | |
| 560 // now we need to lock the resolver mutex to keep the milter threads from | |
| 561 // stepping on each other while parsing the dns answer. | |
| 562 int ret_address = 0; | |
| 563 pthread_mutex_lock(&resolve_mutex); | |
| 564 if (glom.length > 0) { | |
| 565 // parse the answer | |
| 566 ns_msg handle; | |
| 567 ns_rr rr; | |
| 568 if (ns_initparse(glom.answer, glom.length, &handle) == 0) { | |
| 569 // look for ns names | |
| 570 if (nameservers) { | |
| 571 ns_map &ns = *nameservers; | |
| 572 int rrnum = 0; | |
| 573 while (ns_parserr(&handle, ns_s_ns, rrnum++, &rr) == 0) { | |
| 574 if (ns_rr_type(rr) == ns_t_ns) { | |
| 575 char nam[NS_MAXDNAME+1]; | |
| 576 char *n = nam; | |
| 577 const u_char *p = ns_rr_rdata(rr); | |
| 578 while (((n-nam) < NS_MAXDNAME) && ((p-glom.answer) < glom.length) && *p) { | |
| 579 size_t s = *(p++); | |
| 580 if (s > 191) { | |
| 581 // compression pointer | |
| 582 s = (s-192)*256 + *(p++); | |
| 583 if (s >= glom.length) break; // pointer outside bounds of answer | |
| 584 p = glom.answer + s; | |
| 585 s = *(p++); | |
| 586 } | |
| 587 if (s > 0) { | |
| 588 if ((n-nam) >= (NS_MAXDNAME-s)) break; // destination would overflow name buffer | |
| 589 if ((p-glom.answer) >= (glom.length-s)) break; // source outside bounds of answer | |
| 590 memcpy(n, p, s); | |
| 591 n += s; | |
| 592 p += s; | |
| 593 *(n++) = '.'; | |
| 594 } | |
| 595 } | |
| 596 if (n-nam) n--; // remove trailing . | |
| 597 *n = '\0'; // null terminate it | |
| 598 ns.add(nam, question); // ns host to lookup later | |
| 599 } | |
| 600 } | |
| 601 rrnum = 0; | |
| 602 while (ns_parserr(&handle, ns_s_ar, rrnum++, &rr) == 0) { | |
| 603 if (ns_rr_type(rr) == ns_t_a) { | |
| 604 char* nam = (char*)ns_rr_name(rr); | |
| 605 ns_mapper::iterator i = ns.ns_ip.find(nam); | |
| 606 if (i != ns.ns_ip.end()) { | |
| 607 // we want this ip address | |
| 608 int address; | |
| 609 memcpy(&address, ns_rr_rdata(rr), sizeof(address)); | |
| 610 ns.ns_ip[nam] = address; | |
| 611 } | |
| 612 } | |
| 613 } | |
| 614 } | |
| 615 int rrnum = 0; | |
| 616 while (ns_parserr(&handle, ns_s_an, rrnum++, &rr) == 0) { | |
| 617 if (ns_rr_type(rr) == ns_t_a) { | |
| 618 int address; | |
| 619 memcpy(&address, ns_rr_rdata(rr), sizeof(address)); | |
| 620 ret_address = address; | |
| 621 } | |
| 622 } | |
| 623 } | |
| 624 } | |
| 625 pthread_mutex_unlock(&resolve_mutex); | |
| 626 return ret_address; | |
| 627 #else | |
| 628 return glom.answer; | |
| 629 #endif | |
| 630 } | |
| 631 | |
| 632 | |
| 633 //////////////////////////////////////////////// | |
| 634 // check a single dnsbl | |
| 635 // | |
| 636 bool check_single(mlfiPriv &priv, int ip, char *suffix); | |
| 637 bool check_single(mlfiPriv &priv, int ip, char *suffix) { | |
| 638 // make a dns question | |
| 639 const u_char *src = (const u_char *)&ip; | |
| 640 if (src[0] == 127) return false; // don't do dns lookups on localhost | |
| 126 | 641 if (src[0] == 10) return false; // don't do dns lookups on rfc1918 space |
| 642 if ((src[0] == 192) && (src[1] == 168)) return false; | |
| 643 if ((src[0] == 172) && (16 <= src[1]) && (src[1] <= 31)) return false; | |
| 94 | 644 #ifdef NS_MAXDNAME |
| 645 char question[NS_MAXDNAME]; | |
| 646 #else | |
| 647 char question[1000]; | |
| 648 #endif | |
| 649 snprintf(question, sizeof(question), "%u.%u.%u.%u.%s.", src[3], src[2], src[1], src[0], suffix); | |
| 650 // ask the question, if we get an A record it implies a blacklisted ip address | |
| 651 return dns_interface(priv, question, false, NULL); | |
| 652 } | |
| 653 | |
| 654 | |
| 655 //////////////////////////////////////////////// | |
| 656 // check a single dnsbl | |
| 657 // | |
| 658 bool check_single(mlfiPriv &priv, int ip, DNSBL &bl); | |
| 659 bool check_single(mlfiPriv &priv, int ip, DNSBL &bl) { | |
| 660 return check_single(priv, ip, bl.suffix); | |
| 661 } | |
| 662 | |
| 663 | |
| 664 //////////////////////////////////////////////// | |
| 665 // check the dnsbls specified for this recipient | |
| 666 // | |
| 667 bool check_dnsbl(mlfiPriv &priv, dnsblp_list &dnsbll, DNSBLP &rejectlist); | |
| 668 bool check_dnsbl(mlfiPriv &priv, dnsblp_list &dnsbll, DNSBLP &rejectlist) { | |
| 669 for (dnsblp_list::iterator i=dnsbll.begin(); i!=dnsbll.end(); i++) { | |
| 670 DNSBLP dp = *i; // non null by construction | |
| 671 bool st; | |
| 672 map<DNSBLP, bool>::iterator f = priv.checked.find(dp); | |
| 673 if (f == priv.checked.end()) { | |
| 674 // have not checked this list yet | |
| 675 st = check_single(priv, priv.ip, *dp); | |
| 676 rejectlist = dp; | |
| 677 priv.checked[dp] = st; | |
| 678 } | |
| 679 else { | |
| 680 st = (*f).second; | |
| 681 rejectlist = (*f).first; | |
| 682 } | |
| 683 if (st) return st; | |
| 684 } | |
| 685 return false; | |
| 686 } | |
| 687 | |
| 688 | |
| 689 //////////////////////////////////////////////// | |
| 134 | 690 // lookup the domain name part of a hostname on the uribl |
| 117 | 691 // |
| 124 | 692 // if we find part of the hostname on the uribl, return |
| 693 // true and point found to the part of the hostname that we found. | |
| 694 // otherwise, return false and preserve the value of found. | |
| 695 // | |
| 696 bool uriblookup(mlfiPriv &priv ,char *hostname, char *top, char *&found) ; | |
| 697 bool uriblookup(mlfiPriv &priv, char *hostname, char *top, char *&found) { | |
| 117 | 698 // top is pointer to '.' char at end of base domain, or null for ip address form |
| 699 // so for hostname of www.fred.mydomain.co.uk | |
| 700 // top points to-----------------------^ | |
| 701 // and we end up looking at only mydomain.co.uk, ignoring the www.fred stuff | |
| 702 char buf[maxlen]; | |
| 703 if (top) { | |
| 704 // add one more component | |
| 705 *top = '\0'; | |
| 706 char *x = strrchr(hostname, '.'); | |
| 707 if (x) hostname = x+1; | |
| 708 *top = '.'; | |
| 709 } | |
|
131
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uribl lookups fully qualified; allow two component host names
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|
710 snprintf(buf, sizeof(buf), "%s.%s.", hostname, priv.uribl_suffix); |
| 119 | 711 if (dns_interface(priv, buf, false, NULL)) { |
| 117 | 712 if (debug_syslog > 2) { |
| 713 char tmp[maxlen]; | |
| 119 | 714 snprintf(tmp, sizeof(tmp), "found %s on %s", hostname, priv.uribl_suffix); |
| 117 | 715 my_syslog(tmp); |
| 716 } | |
| 124 | 717 found = hostname; |
| 119 | 718 return true; |
| 117 | 719 } |
| 720 return false; | |
| 721 } | |
| 722 | |
| 723 | |
| 724 //////////////////////////////////////////////// | |
| 124 | 725 // uribl checker |
| 726 // ------------- | |
| 727 // hostname MUST not have a trailing dot | |
| 728 // If tld, two level lookup. | |
| 729 // Else, look up three level domain. | |
| 730 // | |
| 731 // if we find part of the hostname on the uribl, return | |
| 732 // true and point found to the part of the hostname that we found. | |
| 733 // otherwise, return false and preserve the value of found. | |
| 734 // | |
| 735 bool check_uribl(mlfiPriv &priv, char *hostname, char *&found) ; | |
| 736 bool check_uribl(mlfiPriv &priv, char *hostname, char *&found) { | |
| 117 | 737 in_addr ip; |
| 738 if (inet_aton(hostname, &ip)) { | |
| 120 | 739 const u_char *src = (const u_char *)&ip.s_addr; |
| 128 | 740 if (src[0] == 127) return false; // don't do dns lookups on localhost |
| 741 if (src[0] == 10) return false; // don't do dns lookups on rfc1918 space | |
| 742 if ((src[0] == 192) && (src[1] == 168)) return false; | |
| 743 if ((src[0] == 172) && (16 <= src[1]) && (src[1] <= 31)) return false; | |
| 124 | 744 static char adr[sizeof "255.255.255.255"]; |
| 120 | 745 snprintf(adr, sizeof(adr), "%u.%u.%u.%u", src[3], src[2], src[1], src[0]); |
| 124 | 746 return (uriblookup(priv, adr, NULL, found)); |
| 117 | 747 } |
| 748 | |
| 749 char *top, *top2, *top3; | |
| 750 top = strrchr(hostname, '.'); | |
| 751 if (top) { | |
| 752 *top = '\0'; | |
| 753 top2 = strrchr(hostname, '.'); | |
| 754 *top = '.'; | |
| 755 | |
| 756 if (top2) { | |
| 757 string_set::iterator i = priv.memory->get_cctlds()->find(top2+1); | |
| 758 string_set::iterator x = priv.memory->get_cctlds()->end(); | |
| 759 // if we have a 2-level-cctld, just look at top three levels of the name | |
| 124 | 760 if (i != x) return uriblookup(priv, hostname, top2, found); |
| 117 | 761 |
| 762 *top2 = '\0'; | |
| 763 top3 = strrchr(hostname, '.'); | |
| 764 *top2 = '.'; | |
| 765 | |
| 766 // if we have more than 3 levels in the name, look at the top three levels of the name | |
| 124 | 767 if (top3 && uriblookup(priv, hostname, top2, found)) return true; |
| 117 | 768 // if that was not found, fall thru to looking at the top two levels |
| 769 } | |
| 770 // look at the top two levels of the name | |
| 124 | 771 return uriblookup(priv, hostname, top, found); |
| 117 | 772 } |
| 773 return false; | |
| 774 } | |
| 775 | |
| 776 | |
| 777 //////////////////////////////////////////////// | |
| 119 | 778 // check the hosts from the body against the content filter and uribl dnsbls |
| 94 | 779 // |
| 124 | 780 // |
| 781 bool check_hosts(mlfiPriv &priv, bool random, int limit, char *&msg, char *&host, int &ip, char *&found); | |
| 782 bool check_hosts(mlfiPriv &priv, bool random, int limit, char *&msg, char *&host, int &ip, char *&found) { | |
| 783 found = NULL; // normally ip address style | |
| 119 | 784 if (!priv.content_suffix && !priv.uribl_suffix) return false; // nothing to check |
| 94 | 785 CONFIG &dc = *priv.pc; |
| 786 string_set &hosts = priv.memory->get_hosts(); | |
| 787 string_set &ignore = *priv.content_host_ignore; | |
| 788 | |
| 789 int count = 0; | |
| 790 int cnt = hosts.size(); // number of hosts we could look at | |
| 791 int_set ips; | |
| 792 ns_map nameservers; | |
| 793 for (string_set::iterator i=hosts.begin(); i!=hosts.end(); i++) { | |
| 794 host = *i; // a reference into hosts, which will live until this smtp transaction is closed | |
| 795 | |
| 796 // don't bother looking up hosts on the ignore list | |
| 797 string_set::iterator j = ignore.find(host); | |
| 798 if (j != ignore.end()) continue; | |
| 799 | |
| 800 // try to only look at limit/cnt fraction of the available cnt host names in random mode | |
| 801 if ((cnt > limit) && (limit > 0) && random) { | |
| 802 int r = rand() % cnt; | |
| 803 if (r >= limit) { | |
| 804 if (debug_syslog > 2) { | |
| 805 char buf[maxlen]; | |
| 806 snprintf(buf, sizeof(buf), "host %s skipped", host); | |
| 807 my_syslog(&priv, buf); | |
| 808 } | |
| 809 continue; | |
| 810 } | |
| 811 } | |
| 812 count++; | |
| 813 ip = dns_interface(priv, host, true, &nameservers); | |
| 814 if (debug_syslog > 2) { | |
| 815 char buf[maxlen]; | |
| 816 if (ip) { | |
| 817 char adr[sizeof "255.255.255.255"]; | |
| 818 adr[0] = '\0'; | |
| 819 inet_ntop(AF_INET, (const u_char *)&ip, adr, sizeof(adr)); | |
| 820 snprintf(buf, sizeof(buf), "host %s found at %s", host, adr); | |
| 821 } | |
| 822 else { | |
| 823 snprintf(buf, sizeof(buf), "host %s not found", host); | |
| 824 } | |
| 825 my_syslog(&priv, buf); | |
| 826 } | |
| 827 if (ip) { | |
| 828 int_set::iterator i = ips.find(ip); | |
| 829 if (i == ips.end()) { | |
| 117 | 830 // we haven't looked this up yet |
| 94 | 831 ips.insert(ip); |
| 124 | 832 // check dnsbl style list |
| 833 if (priv.content_suffix && check_single(priv, ip, priv.content_suffix)) { | |
| 119 | 834 msg = priv.content_message; |
| 835 return true; | |
| 836 } | |
| 124 | 837 // Check uribl & surbl style list |
| 838 if (priv.uribl_suffix && check_uribl(priv, host, found)) { | |
| 119 | 839 msg = priv.uribl_message; |
| 840 return true; | |
| 841 } | |
| 94 | 842 } |
| 843 } | |
| 844 } | |
| 845 limit *= 4; // allow average of 3 ns per host name | |
| 846 for (ns_mapper::iterator i=nameservers.ns_ip.begin(); i!=nameservers.ns_ip.end(); i++) { | |
| 847 count++; | |
| 119 | 848 if ((count > limit) && (limit > 0)) return false; // too many name servers to check them all |
| 94 | 849 host = (*i).first; // a transient reference that needs to be replaced before we return it |
| 850 ip = (*i).second; | |
| 851 if (!ip) ip = dns_interface(priv, host, false, NULL); | |
| 852 if (debug_syslog > 2) { | |
| 853 char buf[maxlen]; | |
| 854 if (ip) { | |
| 855 char adr[sizeof "255.255.255.255"]; | |
| 856 adr[0] = '\0'; | |
| 857 inet_ntop(AF_INET, (const u_char *)&ip, adr, sizeof(adr)); | |
| 858 snprintf(buf, sizeof(buf), "ns %s found at %s", host, adr); | |
| 859 } | |
| 860 else { | |
| 861 snprintf(buf, sizeof(buf), "ns %s not found", host); | |
| 862 } | |
| 863 my_syslog(&priv, buf); | |
| 864 } | |
| 865 if (ip) { | |
| 866 int_set::iterator i = ips.find(ip); | |
| 867 if (i == ips.end()) { | |
| 868 ips.insert(ip); | |
| 119 | 869 if (check_single(priv, ip, priv.content_suffix)) { |
| 870 msg = priv.content_message; | |
| 94 | 871 string_map::iterator j = nameservers.ns_host.find(host); |
| 872 if (j != nameservers.ns_host.end()) { | |
| 873 char *refer = (*j).second; | |
| 874 char buf[maxlen]; | |
| 875 snprintf(buf, sizeof(buf), "%s with nameserver %s", refer, host); | |
| 876 host = register_string(hosts, buf); // put a copy into hosts, and return that reference | |
| 877 } | |
| 878 else { | |
| 879 host = register_string(hosts, host); // put a copy into hosts, and return that reference | |
| 880 } | |
| 881 return true; | |
| 882 } | |
| 883 } | |
| 884 } | |
| 885 } | |
| 886 return false; | |
| 887 } | |
| 888 | |
| 127 | 889 |
| 94 | 890 //////////////////////////////////////////////// |
| 127 | 891 // |
| 892 // this email address is passed in from sendmail, and will normally be | |
| 893 // enclosed in <>. I think older versions of sendmail supplied the <> | |
| 894 // wrapper if the mail client did not, but the current version does not do | |
| 895 // that. So the <> wrapper is now optional. It may have mixed case, just | |
| 896 // as the mail client sent it. We dup the string and convert the duplicate | |
| 897 // to lower case. | |
| 94 | 898 // |
| 899 char *to_lower_string(char *email); | |
| 900 char *to_lower_string(char *email) { | |
| 127 | 901 int n = strlen(email); |
| 902 if (*email == '<') { | |
| 903 // assume it also ends with > | |
| 904 n -= 2; | |
| 905 if (n < 1) return strdup(email); // return "<>" | |
| 906 email++; | |
| 907 } | |
| 908 char *key = strdup(email); | |
| 94 | 909 key[n] = '\0'; |
| 910 for (int i=0; i<n; i++) key[i] = tolower(key[i]); | |
| 911 return key; | |
| 912 } | |
| 913 | |
| 914 | |
| 915 //////////////////////////////////////////////// | |
| 916 // start of sendmail milter interfaces | |
| 917 // | |
| 918 sfsistat mlfi_connect(SMFICTX *ctx, char *hostname, _SOCK_ADDR *hostaddr) | |
| 919 { | |
| 920 // allocate some private memory | |
| 921 mlfiPriv *priv = new mlfiPriv; | |
| 922 if (hostaddr->sa_family == AF_INET) { | |
| 923 priv->ip = ((struct sockaddr_in *)hostaddr)->sin_addr.s_addr; | |
| 924 } | |
| 925 | |
| 926 // save the private data | |
| 927 smfi_setpriv(ctx, (void*)priv); | |
| 928 | |
| 929 // continue processing | |
| 930 return SMFIS_CONTINUE; | |
| 931 } | |
| 932 | |
| 933 sfsistat mlfi_envfrom(SMFICTX *ctx, char **from) | |
| 934 { | |
| 935 mlfiPriv &priv = *MLFIPRIV; | |
| 936 priv.mailaddr = to_lower_string(from[0]); | |
| 136 | 937 priv.authenticated = smfi_getsymval(ctx, "{auth_authen}"); |
| 938 if (priv.authenticated) priv.authenticated = strdup(priv.authenticated); | |
| 94 | 939 return SMFIS_CONTINUE; |
| 940 } | |
| 941 | |
| 942 sfsistat mlfi_envrcpt(SMFICTX *ctx, char **rcpt) | |
| 943 { | |
| 944 DNSBLP rejectlist = NULL; // list that caused the reject | |
| 945 mlfiPriv &priv = *MLFIPRIV; | |
| 946 CONFIG &dc = *priv.pc; | |
| 947 if (!priv.queueid) priv.queueid = strdup(smfi_getsymval(ctx, "i")); | |
| 948 char *rcptaddr = rcpt[0]; | |
| 949 char *loto = to_lower_string(rcptaddr); | |
| 950 CONTEXT &con = *(dc.find_context(loto)->find_context(priv.mailaddr)); | |
| 951 VERIFYP ver = con.find_verify(loto); | |
| 952 if (debug_syslog > 1) { | |
| 953 char buf[maxlen]; | |
| 954 char msg[maxlen]; | |
| 955 snprintf(msg, sizeof(msg), "from <%s> to <%s> using context %s", priv.mailaddr, loto, con.get_full_name(buf,maxlen)); | |
| 956 my_syslog(&priv, msg); | |
| 957 } | |
| 958 free(loto); | |
| 959 char *fromvalue = con.find_from(priv.mailaddr); | |
| 960 status st; | |
| 961 if (priv.authenticated) { | |
| 136 | 962 int c = incr_rcpt_count(priv.authenticated); |
| 963 int l = dc.default_context->find_rate(priv.authenticated); | |
| 964 if (c > l) { | |
| 965 smfi_setreply(ctx, "550", "5.7.1", "recipient rate limit exceeded"); | |
| 966 return SMFIS_REJECT; | |
| 967 } | |
| 968 else { | |
| 969 if (debug_syslog > 1) { | |
| 970 char buf[maxlen]; | |
| 971 char msg[maxlen]; | |
| 972 snprintf(msg, sizeof(msg), "authenticated id %s (%d recipients, %d limit)", priv.authenticated, c, l); | |
| 973 my_syslog(&priv, msg); | |
| 974 } | |
| 975 st = white; | |
| 976 } | |
| 94 | 977 } |
| 978 else if (fromvalue == token_black) { | |
| 979 st = black; | |
| 980 } | |
| 981 else if (fromvalue == token_white) { | |
| 982 st = white; | |
| 983 } | |
| 984 else { | |
| 985 // check the dns based lists | |
| 986 st = (check_dnsbl(priv, con.get_dnsbl_list(), rejectlist)) ? reject : oksofar; | |
| 987 } | |
| 988 if (st == reject) { | |
| 989 // reject the recipient based on some dnsbl | |
| 990 char adr[sizeof "255.255.255.255"]; | |
| 991 adr[0] = '\0'; | |
| 992 inet_ntop(AF_INET, (const u_char *)&priv.ip, adr, sizeof(adr)); | |
| 993 char buf[maxlen]; | |
| 994 snprintf(buf, sizeof(buf), rejectlist->message, adr, adr); | |
| 995 smfi_setreply(ctx, "550", "5.7.1", buf); | |
| 996 return SMFIS_REJECT; | |
| 997 } | |
| 998 if (st == black) { | |
| 999 // reject the recipient based on blacklisting either from or to | |
| 1000 smfi_setreply(ctx, "550", "5.7.1", "no such user"); | |
| 1001 return SMFIS_REJECT; | |
| 1002 } | |
| 1003 if (ver && (st != white)) { | |
| 1004 // try to verify this from/to pair of addresses since it is not explicitly whitelisted | |
| 1005 char *loto = to_lower_string(rcptaddr); | |
| 1006 bool rc = ver->ok(priv.mailaddr, loto); | |
| 1007 free(loto); | |
| 1008 if (!rc) { | |
| 1009 smfi_setreply(ctx, "550", "5.7.1", "no such user"); | |
| 1010 return SMFIS_REJECT; | |
| 1011 } | |
| 1012 } | |
| 1013 // accept the recipient | |
| 1014 if (!con.get_content_filtering()) st = white; | |
| 1015 if (st == oksofar) { | |
| 1016 // but remember the non-whites | |
| 1017 priv.need_content_filter(rcptaddr, con); | |
| 1018 priv.only_whites = false; | |
| 1019 } | |
| 1020 if (st == white) { | |
| 1021 priv.have_whites = true; | |
| 1022 } | |
| 1023 return SMFIS_CONTINUE; | |
| 1024 } | |
| 1025 | |
| 1026 sfsistat mlfi_body(SMFICTX *ctx, u_char *data, size_t len) | |
| 1027 { | |
| 1028 mlfiPriv &priv = *MLFIPRIV; | |
| 1029 if (priv.authenticated) return SMFIS_CONTINUE; | |
| 1030 if (priv.only_whites) return SMFIS_CONTINUE; | |
| 1031 priv.scanner->scan(data, len); | |
| 1032 return SMFIS_CONTINUE; | |
| 1033 } | |
| 1034 | |
| 1035 sfsistat mlfi_eom(SMFICTX *ctx) | |
| 1036 { | |
| 1037 sfsistat rc; | |
| 1038 mlfiPriv &priv = *MLFIPRIV; | |
| 1039 CONFIG &dc = *priv.pc; | |
| 1040 char *host = NULL; | |
| 1041 int ip; | |
| 1042 status st; | |
| 1043 // process end of message | |
| 1044 if (priv.authenticated || priv.only_whites) rc = SMFIS_CONTINUE; | |
| 1045 else { | |
| 1046 // assert env_to not empty | |
| 1047 char buf[maxlen]; | |
| 1048 char *msg = NULL; | |
| 1049 string_set alive; | |
| 1050 bool random = false; | |
| 1051 int limit = 0; | |
| 1052 for (context_map::iterator i=priv.env_to.begin(); i!=priv.env_to.end(); i++) { | |
| 1053 char *rcpt = (*i).first; | |
| 1054 CONTEXT &con = *((*i).second); | |
| 1055 if (!con.acceptable_content(*priv.memory, msg)) { | |
| 1056 // bad html tags or excessive hosts | |
| 1057 smfi_delrcpt(ctx, rcpt); | |
| 1058 } | |
| 1059 else { | |
| 1060 alive.insert(rcpt); | |
| 1061 random |= con.get_host_random(); | |
| 1062 limit = max(limit, con.get_host_limit()); | |
| 1063 } | |
| 1064 } | |
| 1065 bool rejecting = alive.empty(); // if alive is empty, we must have set msg above in acceptable_content() | |
| 1066 if (!rejecting) { | |
| 124 | 1067 char *fmt, *found; |
| 1068 if (check_hosts(priv, random, limit, fmt, host, ip, found)) { | |
| 1069 if (found) { | |
| 1070 // uribl style | |
| 1071 snprintf(buf, sizeof(buf), fmt, host, found); | |
| 1072 } | |
| 1073 else { | |
| 1074 // dnsbl style | |
| 1075 char adr[sizeof "255.255.255.255"]; | |
| 1076 adr[0] = '\0'; | |
| 1077 inet_ntop(AF_INET, (const u_char *)&ip, adr, sizeof(adr)); | |
| 1078 snprintf(buf, sizeof(buf), fmt, host, adr); | |
| 1079 } | |
| 94 | 1080 msg = buf; |
| 1081 rejecting = true; | |
| 1082 } | |
| 1083 } | |
| 1084 if (!rejecting) { | |
| 1085 rc = SMFIS_CONTINUE; | |
| 1086 } | |
| 1087 else if (!priv.have_whites) { | |
| 1088 // can reject the entire message | |
| 1089 smfi_setreply(ctx, "550", "5.7.1", msg); | |
| 1090 rc = SMFIS_REJECT; | |
| 1091 } | |
| 1092 else { | |
| 1093 // need to accept it but remove the recipients that don't want it | |
| 1094 for (string_set::iterator i=alive.begin(); i!=alive.end(); i++) { | |
| 1095 char *rcpt = *i; | |
| 1096 smfi_delrcpt(ctx, rcpt); | |
| 1097 } | |
| 1098 rc = SMFIS_CONTINUE; | |
| 1099 } | |
| 1100 } | |
| 1101 // reset for a new message on the same connection | |
| 1102 mlfi_abort(ctx); | |
| 1103 return rc; | |
| 1104 } | |
| 1105 | |
| 1106 sfsistat mlfi_abort(SMFICTX *ctx) | |
| 1107 { | |
| 1108 mlfiPriv &priv = *MLFIPRIV; | |
| 1109 priv.reset(); | |
| 1110 return SMFIS_CONTINUE; | |
| 1111 } | |
| 1112 | |
| 1113 sfsistat mlfi_close(SMFICTX *ctx) | |
| 1114 { | |
| 1115 mlfiPriv *priv = MLFIPRIV; | |
| 1116 if (!priv) return SMFIS_CONTINUE; | |
| 1117 delete priv; | |
| 1118 smfi_setpriv(ctx, NULL); | |
| 1119 return SMFIS_CONTINUE; | |
| 1120 } | |
| 1121 | |
| 1122 struct smfiDesc smfilter = | |
| 1123 { | |
| 1124 "DNSBL", // filter name | |
| 1125 SMFI_VERSION, // version code -- do not change | |
| 1126 SMFIF_DELRCPT, // flags | |
| 1127 mlfi_connect, // connection info filter | |
| 1128 NULL, // SMTP HELO command filter | |
| 1129 mlfi_envfrom, // envelope sender filter | |
| 1130 mlfi_envrcpt, // envelope recipient filter | |
| 1131 NULL, // header filter | |
| 1132 NULL, // end of header | |
| 1133 mlfi_body, // body block filter | |
| 1134 mlfi_eom, // end of message | |
| 1135 mlfi_abort, // message aborted | |
| 1136 mlfi_close, // connection cleanup | |
| 1137 }; | |
| 1138 | |
| 1139 | |
| 1140 //////////////////////////////////////////////// | |
| 1141 // reload the config | |
| 1142 // | |
| 1143 CONFIG* new_conf(); | |
| 1144 CONFIG* new_conf() { | |
| 1145 CONFIG *newc = new CONFIG; | |
| 1146 pthread_mutex_lock(&config_mutex); | |
| 1147 newc->generation = generation++; | |
| 1148 pthread_mutex_unlock(&config_mutex); | |
| 1149 if (debug_syslog) { | |
| 1150 char buf[maxlen]; | |
| 1151 snprintf(buf, sizeof(buf), "loading configuration generation %d", newc->generation); | |
| 1152 my_syslog(buf); | |
| 1153 } | |
| 1154 if (load_conf(*newc, "dnsbl.conf")) { | |
| 1155 newc->load_time = time(NULL); | |
| 1156 return newc; | |
| 1157 } | |
| 1158 delete newc; | |
| 1159 return NULL; | |
| 1160 } | |
| 1161 | |
| 1162 | |
| 1163 //////////////////////////////////////////////// | |
| 1164 // thread to watch the old config files for changes | |
| 1165 // and reload when needed. we also cleanup old | |
| 1166 // configs whose reference count has gone to zero. | |
| 136 | 1167 // we also clear the SMTP AUTH recipient counts hourly |
| 94 | 1168 // |
| 1169 void* config_loader(void *arg); | |
| 1170 void* config_loader(void *arg) { | |
| 136 | 1171 int loop = 0; |
| 94 | 1172 typedef set<CONFIG *> configp_set; |
| 1173 configp_set old_configs; | |
| 1174 while (loader_run) { | |
| 1175 sleep(180); // look for modifications every 3 minutes | |
| 1176 if (!loader_run) break; | |
| 136 | 1177 loop++; |
| 1178 if (loop == 20) { | |
| 1179 // three minutes thru each loop, 20 loops per hour | |
| 1180 // clear the recipient counts | |
| 1181 pthread_mutex_lock(&rate_mutex); | |
| 138 | 1182 for (rcpt_rates::iterator i=rcpt_counts.begin(); i!=rcpt_counts.end(); i++) { |
| 140 | 1183 (*i).second = 0; |
| 138 | 1184 } |
| 136 | 1185 pthread_mutex_unlock(&rate_mutex); |
| 137 | 1186 loop = 0; |
| 136 | 1187 } |
| 94 | 1188 CONFIG &dc = *config; |
| 1189 time_t then = dc.load_time; | |
| 1190 struct stat st; | |
| 1191 bool reload = false; | |
| 1192 for (string_set::iterator i=dc.config_files.begin(); i!=dc.config_files.end(); i++) { | |
| 1193 char *fn = *i; | |
| 1194 if (stat(fn, &st)) reload = true; // file disappeared | |
| 1195 else if (st.st_mtime > then) reload = true; // file modified | |
| 1196 if (reload) break; | |
| 1197 } | |
| 1198 if (reload) { | |
| 1199 CONFIG *newc = new_conf(); | |
| 1200 if (newc) { | |
| 1201 // replace the global config pointer | |
| 1202 pthread_mutex_lock(&config_mutex); | |
| 1203 CONFIG *old = config; | |
| 1204 config = newc; | |
| 1205 pthread_mutex_unlock(&config_mutex); | |
| 1206 if (old) old_configs.insert(old); | |
| 1207 } | |
| 1208 else { | |
| 1209 // failed to load new config | |
| 1210 my_syslog("failed to load new configuration"); | |
| 1211 system("echo 'failed to load new dnsbl configuration from /etc/dnsbl' | mail -s 'error in /etc/dnsbl configuration' root"); | |
| 1212 // update the load time on the current config to prevent complaining every 3 minutes | |
| 1213 dc.load_time = time(NULL); | |
| 1214 } | |
| 1215 } | |
| 1216 // now look for old configs with zero ref counts | |
| 1217 for (configp_set::iterator i=old_configs.begin(); i!=old_configs.end(); ) { | |
| 1218 CONFIG *old = *i; | |
| 1219 if (!old->reference_count) { | |
| 1220 if (debug_syslog) { | |
| 1221 char buf[maxlen]; | |
| 1222 snprintf(buf, sizeof(buf), "freeing memory for old configuration generation %d", old->generation); | |
| 1223 my_syslog(buf); | |
| 1224 } | |
| 1225 delete old; // destructor does all the work | |
| 1226 old_configs.erase(i++); | |
| 1227 } | |
| 1228 else i++; | |
| 1229 } | |
| 1230 } | |
| 1231 return NULL; | |
| 1232 } | |
| 1233 | |
| 1234 | |
| 1235 void usage(char *prog); | |
| 1236 void usage(char *prog) | |
| 1237 { | |
| 1238 fprintf(stderr, "Usage: %s [-d [level]] [-c] [-s] [-e from|to] -r port -p sm-sock-addr [-t timeout]\n", prog); | |
| 1239 fprintf(stderr, "where port is for the connection to our own dns resolver processes\n"); | |
| 1240 fprintf(stderr, " and should be local-domain-socket-file-name\n"); | |
| 1241 fprintf(stderr, "where sm-sock-addr is for the connection to sendmail\n"); | |
| 1242 fprintf(stderr, " and should be one of\n"); | |
| 1243 fprintf(stderr, " inet:port@ip-address\n"); | |
| 1244 fprintf(stderr, " local:local-domain-socket-file-name\n"); | |
| 1245 fprintf(stderr, "-c will load and dump the config to stdout\n"); | |
| 1246 fprintf(stderr, "-s will stress test the config loading code by repeating the load/free cycle\n"); | |
| 1247 fprintf(stderr, " in an infinte loop.\n"); | |
| 1248 fprintf(stderr, "-d will set the syslog message level, currently 0 to 3\n"); | |
| 1249 fprintf(stderr, "-e will print the results of looking up the from and to addresses in the\n"); | |
| 1250 fprintf(stderr, " current config. The | character is used to separate the from and to\n"); | |
| 1251 fprintf(stderr, " addresses in the argument to the -e switch\n"); | |
| 1252 } | |
| 1253 | |
| 1254 | |
| 1255 | |
| 1256 void setup_socket(char *sock); | |
| 1257 void setup_socket(char *sock) { | |
| 1258 unlink(sock); | |
| 1259 // sockaddr_un addr; | |
| 1260 // memset(&addr, '\0', sizeof addr); | |
| 1261 // addr.sun_family = AF_UNIX; | |
| 1262 // strncpy(addr.sun_path, sock, sizeof(addr.sun_path)-1); | |
| 1263 // int s = socket(AF_UNIX, SOCK_STREAM, 0); | |
| 1264 // bind(s, (sockaddr*)&addr, sizeof(addr)); | |
| 1265 // close(s); | |
| 1266 } | |
| 1267 | |
| 1268 | |
| 1269 /* | |
| 1270 * The signal handler function -- only gets called when a SIGCHLD | |
| 1271 * is received, ie when a child terminates | |
| 1272 */ | |
| 1273 void sig_chld(int signo) | |
| 1274 { | |
| 1275 int status; | |
| 1276 /* Wait for any child without blocking */ | |
| 1277 while (waitpid(-1, &status, WNOHANG) > 0) { | |
| 1278 // ignore child exit status, we only do this to cleanup zombies | |
| 1279 } | |
| 1280 } | |
| 1281 | |
| 1282 | |
| 1283 int main(int argc, char**argv) | |
| 1284 { | |
| 1285 token_init(); | |
| 1286 bool check = false; | |
| 1287 bool stress = false; | |
| 1288 bool setconn = false; | |
| 1289 bool setreso = false; | |
| 1290 char *email = NULL; | |
| 1291 int c; | |
| 1292 const char *args = "r:p:t:e:d:chs"; | |
| 1293 extern char *optarg; | |
| 1294 | |
| 1295 // Process command line options | |
| 1296 while ((c = getopt(argc, argv, args)) != -1) { | |
| 1297 switch (c) { | |
| 1298 case 'r': | |
| 1299 if (optarg == NULL || *optarg == '\0') { | |
| 1300 fprintf(stderr, "Illegal resolver socket: %s\n", optarg); | |
| 1301 exit(EX_USAGE); | |
| 1302 } | |
| 1303 resolver_port = strdup(optarg); | |
| 1304 setup_socket(resolver_port); | |
| 1305 setreso = true; | |
| 1306 break; | |
| 1307 | |
| 1308 case 'p': | |
| 1309 if (optarg == NULL || *optarg == '\0') { | |
| 1310 fprintf(stderr, "Illegal sendmail socket: %s\n", optarg); | |
| 1311 exit(EX_USAGE); | |
| 1312 } | |
| 1313 if (smfi_setconn(optarg) == MI_FAILURE) { | |
| 1314 fprintf(stderr, "smfi_setconn failed\n"); | |
| 1315 exit(EX_SOFTWARE); | |
| 1316 } | |
| 1317 if (strncasecmp(optarg, "unix:", 5) == 0) setup_socket(optarg + 5); | |
| 1318 else if (strncasecmp(optarg, "local:", 6) == 0) setup_socket(optarg + 6); | |
| 1319 setconn = true; | |
| 1320 break; | |
| 1321 | |
| 1322 case 't': | |
| 1323 if (optarg == NULL || *optarg == '\0') { | |
| 1324 fprintf(stderr, "Illegal timeout: %s\n", optarg); | |
| 1325 exit(EX_USAGE); | |
| 1326 } | |
| 1327 if (smfi_settimeout(atoi(optarg)) == MI_FAILURE) { | |
| 1328 fprintf(stderr, "smfi_settimeout failed\n"); | |
| 1329 exit(EX_SOFTWARE); | |
| 1330 } | |
| 1331 break; | |
| 1332 | |
| 1333 case 'e': | |
| 1334 if (email) free(email); | |
| 1335 email = strdup(optarg); | |
| 1336 break; | |
| 1337 | |
| 1338 case 'c': | |
| 1339 check = true; | |
| 1340 break; | |
| 1341 | |
| 1342 case 's': | |
| 1343 stress = true; | |
| 1344 break; | |
| 1345 | |
| 1346 case 'd': | |
| 1347 if (optarg == NULL || *optarg == '\0') debug_syslog = 1; | |
| 1348 else debug_syslog = atoi(optarg); | |
| 1349 break; | |
| 1350 | |
| 1351 case 'h': | |
| 1352 default: | |
| 1353 usage(argv[0]); | |
| 1354 exit(EX_USAGE); | |
| 1355 } | |
| 1356 } | |
| 1357 | |
| 1358 if (check) { | |
| 1359 use_syslog = false; | |
| 1360 debug_syslog = 10; | |
| 1361 CONFIG *conf = new_conf(); | |
| 1362 if (conf) { | |
| 1363 conf->dump(); | |
| 1364 delete conf; | |
| 1365 return 0; | |
| 1366 } | |
| 1367 else { | |
| 1368 return 1; // config failed to load | |
| 1369 } | |
| 1370 } | |
| 1371 | |
| 1372 if (stress) { | |
| 1373 fprintf(stdout, "stress testing\n"); | |
| 1374 while (1) { | |
| 1375 for (int i=0; i<10; i++) { | |
| 1376 CONFIG *conf = new_conf(); | |
| 1377 if (conf) delete conf; | |
| 1378 } | |
| 1379 fprintf(stdout, "."); | |
| 1380 fflush(stdout); | |
| 1381 sleep(1); | |
| 1382 } | |
| 1383 } | |
| 1384 | |
| 1385 if (email) { | |
| 1386 char *x = strchr(email, '|'); | |
| 1387 if (x) { | |
| 1388 *x = '\0'; | |
| 1389 char *from = strdup(email); | |
| 1390 char *to = strdup(x+1); | |
| 1391 use_syslog = false; | |
| 1392 CONFIG *conf = new_conf(); | |
| 1393 if (conf) { | |
| 1394 CONTEXTP con = conf->find_context(to); | |
| 1395 char buf[maxlen]; | |
| 1396 fprintf(stdout, "envelope to <%s> finds context %s\n", to, con->get_full_name(buf,maxlen)); | |
| 1397 CONTEXTP fc = con->find_context(from); | |
| 1398 fprintf(stdout, "envelope from <%s> finds context %s\n", from, fc->get_full_name(buf,maxlen)); | |
| 1399 char *st = fc->find_from(from); | |
| 1400 fprintf(stdout, "envelope from <%s> finds status %s\n", from, st); | |
| 1401 delete conf; | |
| 1402 } | |
| 1403 } | |
| 1404 return 0; | |
| 1405 } | |
| 1406 | |
| 1407 if (!setconn) { | |
| 1408 fprintf(stderr, "%s: Missing required -p argument\n", argv[0]); | |
| 1409 usage(argv[0]); | |
| 1410 exit(EX_USAGE); | |
| 1411 } | |
| 1412 | |
| 1413 if (!setreso) { | |
| 1414 fprintf(stderr, "%s: Missing required -r argument\n", argv[0]); | |
| 1415 usage(argv[0]); | |
| 1416 exit(EX_USAGE); | |
| 1417 } | |
| 1418 | |
| 1419 if (smfi_register(smfilter) == MI_FAILURE) { | |
| 1420 fprintf(stderr, "smfi_register failed\n"); | |
| 1421 exit(EX_UNAVAILABLE); | |
| 1422 } | |
| 1423 | |
| 1424 // switch to background mode | |
| 1425 if (daemon(1,0) < 0) { | |
| 1426 fprintf(stderr, "daemon() call failed\n"); | |
| 1427 exit(EX_UNAVAILABLE); | |
| 1428 } | |
| 1429 | |
| 1430 // write the pid | |
| 1431 const char *pidpath = "/var/run/dnsbl.pid"; | |
| 1432 unlink(pidpath); | |
| 1433 FILE *f = fopen(pidpath, "w"); | |
| 1434 if (f) { | |
| 1435 #ifdef linux | |
| 1436 // from a comment in the DCC source code: | |
| 1437 // Linux threads are broken. Signals given the | |
| 1438 // original process are delivered to only the | |
| 1439 // thread that happens to have that PID. The | |
| 1440 // sendmail libmilter thread that needs to hear | |
| 1441 // SIGINT and other signals does not, and that breaks | |
| 1442 // scripts that need to stop milters. | |
| 1443 // However, signaling the process group works. | |
| 1444 fprintf(f, "-%d\n", (u_int)getpgrp()); | |
| 1445 #else | |
| 1446 fprintf(f, "%d\n", (u_int)getpid()); | |
| 1447 #endif | |
| 1448 fclose(f); | |
| 1449 } | |
| 1450 | |
| 1451 // initialize the thread sync objects | |
| 1452 pthread_mutex_init(&config_mutex, 0); | |
| 1453 pthread_mutex_init(&syslog_mutex, 0); | |
| 1454 pthread_mutex_init(&resolve_mutex, 0); | |
| 1455 pthread_mutex_init(&fd_pool_mutex, 0); | |
| 1456 | |
| 1457 // drop root privs | |
| 1458 struct passwd *pw = getpwnam("dnsbl"); | |
| 1459 if (pw) { | |
| 1460 if (setgid(pw->pw_gid) == -1) { | |
| 1461 my_syslog("failed to switch to group dnsbl"); | |
| 1462 } | |
| 1463 if (setuid(pw->pw_uid) == -1) { | |
| 1464 my_syslog("failed to switch to user dnsbl"); | |
| 1465 } | |
| 1466 } | |
| 1467 | |
| 1468 // load the initial config | |
| 1469 config = new_conf(); | |
| 1470 if (!config) { | |
| 1471 my_syslog("failed to load initial configuration, quitting"); | |
| 1472 exit(1); | |
| 1473 } | |
| 1474 | |
| 1475 // fork off the resolver listener process | |
| 1476 pid_t child = fork(); | |
| 1477 if (child < 0) { | |
| 1478 my_syslog("failed to create resolver listener process"); | |
| 1479 exit(0); | |
| 1480 } | |
| 1481 if (child == 0) { | |
| 1482 // we are the child - dns resolver listener process | |
| 1483 resolver_socket = socket(AF_UNIX, SOCK_STREAM, 0); | |
| 1484 if (resolver_socket < 0) { | |
| 1485 my_syslog("child failed to create resolver socket"); | |
| 1486 exit(0); // failed | |
| 1487 } | |
| 1488 sockaddr_un server; | |
| 1489 memset(&server, '\0', sizeof(server)); | |
| 1490 server.sun_family = AF_UNIX; | |
| 1491 strncpy(server.sun_path, resolver_port, sizeof(server.sun_path)-1); | |
| 1492 //try to bind the address to the socket. | |
| 1493 if (bind(resolver_socket, (sockaddr *)&server, sizeof(server)) < 0) { | |
| 1494 // bind failed | |
| 1495 shutdown(resolver_socket, SHUT_RDWR); | |
| 1496 close(resolver_socket); | |
| 1497 my_syslog("child failed to bind resolver socket"); | |
| 1498 exit(0); // failed | |
| 1499 } | |
| 1500 //listen on the socket. | |
| 1501 if (listen(resolver_socket, 10) < 0) { | |
| 1502 // listen failed | |
| 1503 shutdown(resolver_socket, SHUT_RDWR); | |
| 1504 close(resolver_socket); | |
| 1505 my_syslog("child failed to listen to resolver socket"); | |
| 1506 exit(0); // failed | |
| 1507 } | |
| 1508 // setup sigchld handler to prevent zombies | |
| 1509 struct sigaction act; | |
| 1510 act.sa_handler = sig_chld; // Assign sig_chld as our SIGCHLD handler | |
| 1511 sigemptyset(&act.sa_mask); // We don't want to block any other signals in this example | |
| 1512 act.sa_flags = SA_NOCLDSTOP; // only want children that have terminated | |
| 1513 if (sigaction(SIGCHLD, &act, NULL) < 0) { | |
| 1514 my_syslog("child failed to setup SIGCHLD handler"); | |
| 1515 exit(0); // failed | |
| 1516 } | |
| 1517 while (true) { | |
| 1518 sockaddr_un client; | |
| 1519 socklen_t clientlen = sizeof(client); | |
| 1520 int s = accept(resolver_socket, (sockaddr *)&client, &clientlen); | |
| 1521 if (s > 0) { | |
| 1522 // accept worked, it did not get cancelled before we could accept it | |
| 1523 // fork off a process to handle this connection | |
| 1524 int newchild = fork(); | |
| 1525 if (newchild == 0) { | |
| 1526 // this is the worker process | |
| 1527 // child does not need the listening socket | |
| 1528 close(resolver_socket); | |
| 1529 process_resolver_requests(s); | |
| 1530 exit(0); | |
| 1531 } | |
| 1532 else { | |
| 1533 // this is the parent | |
| 1534 // parent does not need the accepted socket | |
| 1535 close(s); | |
| 1536 } | |
| 1537 } | |
| 1538 } | |
| 1539 exit(0); // make sure we don't fall thru. | |
| 1540 } | |
| 1541 else { | |
| 1542 sleep(2); // allow child to get started | |
| 1543 } | |
| 1544 | |
| 1545 // only create threads after the fork() in daemon | |
| 1546 pthread_t tid; | |
| 1547 if (pthread_create(&tid, 0, config_loader, 0)) | |
| 1548 my_syslog("failed to create config loader thread"); | |
| 1549 if (pthread_detach(tid)) | |
| 1550 my_syslog("failed to detach config loader thread"); | |
| 1551 if (pthread_create(&tid, 0, verify_closer, 0)) | |
| 1552 my_syslog("failed to create verify closer thread"); | |
| 1553 if (pthread_detach(tid)) | |
| 1554 my_syslog("failed to detach verify closer thread"); | |
| 1555 | |
| 1556 time_t starting = time(NULL); | |
| 1557 int rc = smfi_main(); | |
| 1558 if ((rc != MI_SUCCESS) && (time(NULL) > starting+5*60)) { | |
| 1559 my_syslog("trying to restart after smfi_main()"); | |
| 1560 loader_run = false; // eventually the config loader thread will terminate | |
| 1561 execvp(argv[0], argv); | |
| 1562 } | |
| 1563 exit((rc == MI_SUCCESS) ? 0 : EX_UNAVAILABLE); | |
| 1564 } | |
| 1565 |