Mercurial > dnsbl
annotate src/dnsbl.cpp @ 90:962a1f8f1d9f stable-5-4
add verify statement to verify addresses with better mx host
| author | carl |
|---|---|
| date | Sun, 18 Sep 2005 10:19:58 -0700 |
| parents | 946fc1bcfb2c |
| children | 505e77188317 |
| rev | line source |
|---|---|
| 89 | 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; | |
| 91 int NULL_SOCKET = -1; | |
| 92 char *resolver_port = NULL; // unix domain socket to talk to the dns resolver process | |
| 93 int resolver_socket = NULL_SOCKET; // socket used to listen for resolver requests | |
|
90
962a1f8f1d9f
add verify statement to verify addresses with better mx host
carl
parents:
89
diff
changeset
|
94 time_t ERROR_SOCKET_TIME = 60; // number of seconds between attempts to open a socket to the dns resolver process |
| 89 | 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 | |
| 136 u_char answer[NS_PACKETSZ]; // with a resolver, we return resolver answers | |
| 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 | |
| 191 time_t now = time(NULL); | |
| 192 if ((now - last_error_time) < ERROR_SOCKET_TIME) return NULL_SOCKET; | |
| 193 | |
| 194 // nothing recent, maybe this time it will work | |
| 195 int sock = NULL_SOCKET; | |
| 196 sockaddr_un server; | |
| 197 memset(&server, '\0', sizeof(server)); | |
| 198 server.sun_family = AF_UNIX; | |
| 199 strncpy(server.sun_path, resolver_port, sizeof(server.sun_path)-1); | |
| 200 sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
| 201 if (sock != NULL_SOCKET) { | |
| 202 bool rc = (connect(sock, (sockaddr *)&server, sizeof(server)) == 0); | |
| 203 if (!rc) { | |
| 204 my_disconnect(sock, false); | |
| 205 sock = NULL_SOCKET; | |
| 206 last_error_time = now; | |
| 207 } | |
| 208 } | |
| 209 else last_error_time = now; | |
| 210 if (sock != NULL_SOCKET) { | |
| 211 pthread_mutex_lock(&fd_pool_mutex); | |
| 212 resolver_sock_count++; | |
| 213 pthread_mutex_unlock(&fd_pool_mutex); | |
| 214 } | |
| 215 return sock; | |
| 216 } | |
| 217 | |
| 218 | |
| 219 mlfiPriv::mlfiPriv() { | |
| 220 pthread_mutex_lock(&config_mutex); | |
| 221 pc = config; | |
| 222 pc->reference_count++; | |
| 223 pthread_mutex_unlock(&config_mutex); | |
| 224 get_fd(); | |
| 225 ip = 0; | |
| 226 mailaddr = NULL; | |
| 227 queueid = NULL; | |
| 228 authenticated = false; | |
| 229 have_whites = false; | |
| 230 only_whites = true; | |
| 231 memory = NULL; | |
| 232 scanner = NULL; | |
| 233 content_suffix = NULL; | |
| 234 content_message = NULL; | |
| 235 content_host_ignore = NULL; | |
| 236 } | |
| 237 | |
| 238 mlfiPriv::~mlfiPriv() { | |
| 239 return_fd(); | |
| 240 pthread_mutex_lock(&config_mutex); | |
| 241 pc->reference_count--; | |
| 242 pthread_mutex_unlock(&config_mutex); | |
| 243 reset(true); | |
| 244 } | |
| 245 | |
| 246 void mlfiPriv::reset(bool final) { | |
| 247 if (mailaddr) free(mailaddr); | |
| 248 if (queueid) free(queueid); | |
| 249 discard(env_to); | |
| 250 if (memory) delete memory; | |
| 251 if (scanner) delete scanner; | |
| 252 if (!final) { | |
| 253 mailaddr = NULL; | |
| 254 queueid = NULL; | |
| 255 authenticated = false; | |
| 256 have_whites = false; | |
| 257 only_whites = true; | |
| 258 memory = NULL; | |
| 259 scanner = NULL; | |
| 260 content_suffix = NULL; | |
| 261 content_message = NULL; | |
| 262 content_host_ignore = NULL; | |
| 263 } | |
| 264 } | |
| 265 | |
| 266 void mlfiPriv::get_fd() { | |
| 267 err = true; | |
| 268 fd = NULL_SOCKET; | |
| 269 int result = pthread_mutex_lock(&fd_pool_mutex); | |
| 270 if (!result) { | |
| 271 std::set<int>::iterator i; | |
| 272 i = fd_pool.begin(); | |
| 273 if (i != fd_pool.end()) { | |
| 274 // have at least one fd in the pool | |
| 275 err = false; | |
| 276 fd = *i; | |
| 277 fd_pool.erase(fd); | |
| 278 resolver_pool_size--; | |
| 279 pthread_mutex_unlock(&fd_pool_mutex); | |
| 280 } | |
| 281 else { | |
| 282 // pool is empty, get a new fd | |
| 283 pthread_mutex_unlock(&fd_pool_mutex); | |
| 284 fd = my_connect(); | |
| 285 err = (fd == NULL_SOCKET); | |
| 286 } | |
| 287 } | |
| 288 else { | |
| 289 // cannot lock the pool, just get a new fd | |
| 290 fd = my_connect(); | |
| 291 err = (fd == NULL_SOCKET); | |
| 292 } | |
| 293 } | |
| 294 | |
| 295 void mlfiPriv::return_fd() { | |
| 296 if (err) { | |
| 297 // this fd got a socket error, so close it, rather than returning it to the pool | |
| 298 my_disconnect(fd); | |
| 299 } | |
| 300 else { | |
| 301 int result = pthread_mutex_lock(&fd_pool_mutex); | |
| 302 if (!result) { | |
| 303 if ((resolver_sock_count > resolver_pool_size*5) || (resolver_pool_size < 5)) { | |
| 304 // return the fd to the pool | |
| 305 fd_pool.insert(fd); | |
| 306 resolver_pool_size++; | |
| 307 pthread_mutex_unlock(&fd_pool_mutex); | |
| 308 } | |
| 309 else { | |
| 310 // more than 20% of the open resolver sockets are in the pool, and the | |
| 311 // pool as at least 5 sockets. that is enough, so just close this one. | |
| 312 pthread_mutex_unlock(&fd_pool_mutex); | |
| 313 my_disconnect(fd); | |
| 314 } | |
| 315 } | |
| 316 else { | |
| 317 // could not lock the pool, so just close the fd | |
| 318 my_disconnect(fd); | |
| 319 } | |
| 320 } | |
| 321 } | |
| 322 | |
| 323 int mlfiPriv::my_write(char *buf, int len) { | |
| 324 if (err) return 0; | |
| 325 int rs = 0; | |
| 326 while (len) { | |
| 327 int ws = write(fd, buf, len); | |
| 328 if (ws > 0) { | |
| 329 rs += ws; | |
| 330 len -= ws; | |
| 331 buf += ws; | |
| 332 } | |
| 333 else { | |
| 334 // peer closed the socket! | |
| 335 rs = 0; | |
| 336 err = true; | |
| 337 break; | |
| 338 } | |
| 339 } | |
| 340 return rs; | |
| 341 } | |
| 342 | |
| 343 int mlfiPriv::my_read(char *buf, int len) { | |
| 344 if (err) return 0; | |
| 345 int rs = 0; | |
| 346 while (len > 1) { | |
| 347 int ws = read(fd, buf, len); | |
| 348 if (ws > 0) { | |
| 349 rs += ws; | |
| 350 len -= ws; | |
| 351 buf += ws; | |
| 352 } | |
| 353 else { | |
| 354 // peer closed the socket! | |
| 355 rs = 0; | |
| 356 err = true; | |
| 357 break; | |
| 358 } | |
| 359 } | |
| 360 return rs; | |
| 361 } | |
| 362 | |
| 363 void mlfiPriv::need_content_filter(char *rcpt, CONTEXT &con) { | |
| 364 register_string(env_to, rcpt, &con); | |
| 365 if (!memory) { | |
| 366 // first recipient that needs content filtering sets all | |
| 367 // the content filtering parameters | |
| 368 memory = new recorder(this, con.get_html_tags(), con.get_content_tlds()); | |
| 369 scanner = new url_scanner(memory); | |
| 370 content_suffix = con.get_content_suffix(); | |
| 371 content_message = con.get_content_message(); | |
| 372 content_host_ignore = &con.get_content_host_ignore(); | |
| 373 } | |
| 374 } | |
| 375 | |
| 376 #define MLFIPRIV ((struct mlfiPriv *) smfi_getpriv(ctx)) | |
| 377 | |
| 378 | |
| 379 //////////////////////////////////////////////// | |
| 380 // syslog a message | |
| 381 // | |
| 382 void my_syslog(mlfiPriv *priv, char *text) { | |
| 383 char buf[maxlen]; | |
| 384 if (priv) { | |
| 385 snprintf(buf, sizeof(buf), "%s: %s", priv->queueid, text); | |
| 386 text = buf; | |
| 387 } | |
| 388 if (use_syslog) { | |
| 389 pthread_mutex_lock(&syslog_mutex); | |
| 390 if (!syslog_opened) { | |
| 391 openlog("dnsbl", LOG_PID, LOG_MAIL); | |
| 392 syslog_opened = true; | |
| 393 } | |
| 394 syslog(LOG_NOTICE, "%s", text); | |
| 395 // closelog(); | |
| 396 // syslog_opened = false; | |
| 397 pthread_mutex_unlock(&syslog_mutex); | |
| 398 } | |
| 399 else { | |
| 400 printf("%s \n", text); | |
| 401 } | |
| 402 } | |
| 403 | |
| 404 void my_syslog(char *text) { | |
| 405 my_syslog(NULL, text); | |
| 406 } | |
| 407 | |
| 408 | |
| 409 //////////////////////////////////////////////// | |
| 410 // read a resolver request from the socket, process it, and | |
| 411 // write the result back to the socket. | |
| 412 | |
| 413 void process_resolver_requests(int socket); | |
| 414 void process_resolver_requests(int socket) { | |
| 415 #ifdef NS_MAXDNAME | |
| 416 char question[NS_MAXDNAME]; | |
| 417 #else | |
| 418 char question[1000]; | |
| 419 #endif | |
| 420 glommer glom; | |
| 421 | |
| 422 int maxq = sizeof(question); | |
| 423 while (true) { | |
| 424 // read a question | |
| 425 int rs = 0; | |
|
90
962a1f8f1d9f
add verify statement to verify addresses with better mx host
carl
parents:
89
diff
changeset
|
426 while (rs < maxq) { |
| 89 | 427 int ns = read(socket, question+rs, maxq-rs); |
| 428 if (ns > 0) { | |
| 429 rs += ns; | |
| 430 if (question[rs-1] == '\0') { | |
| 431 // last byte read was the null terminator, we are done | |
| 432 break; | |
| 433 } | |
| 434 } | |
| 435 else { | |
| 436 // peer closed the socket | |
| 437 //my_syslog("!!child worker process, peer closed socket while reading question"); | |
| 438 shutdown(socket, SHUT_RDWR); | |
| 439 close(socket); | |
| 440 return; | |
| 441 } | |
| 442 } | |
|
90
962a1f8f1d9f
add verify statement to verify addresses with better mx host
carl
parents:
89
diff
changeset
|
443 question[rs-1] = '\0'; // ensure null termination |
| 89 | 444 |
| 445 // find the answer | |
| 446 #ifdef NS_PACKETSZ | |
| 447 //char text[1000]; | |
| 448 //snprintf(text, sizeof(text), "!!child worker process has a question %s", question); | |
| 449 //my_syslog(text); | |
| 450 glom.length = res_search(question, ns_c_in, ns_t_a, glom.answer, sizeof(glom.answer)); | |
| 451 if (glom.length < 0) glom.length = 0; // represent all errors as zero length answers | |
| 452 #else | |
| 453 glom.length = sizeof(glom.answer); | |
| 454 glom.answer = 0; | |
| 455 struct hostent *host = gethostbyname(question); | |
| 456 if (host && (host->h_addrtype == AF_INET)) { | |
| 457 memcpy(&glom.answer, host->h_addr, sizeof(glom.answer)); | |
| 458 } | |
| 459 #endif | |
| 460 | |
| 461 // write the answer | |
| 462 char *buf = (char *)&glom; | |
| 463 int len = glom.length + sizeof(glom.length); | |
| 464 //snprintf(text, sizeof(text), "!!child worker process writing answer length %d for total %d", glom.length, len); | |
| 465 //my_syslog(text); | |
| 466 int ws = 0; | |
| 467 while (len > ws) { | |
| 468 int ns = write(socket, buf+ws, len-ws); | |
| 469 if (ns > 0) { | |
| 470 ws += ns; | |
| 471 } | |
| 472 else { | |
| 473 // peer closed the socket! | |
| 474 //my_syslog("!!child worker process, peer closed socket while writing answer"); | |
| 475 shutdown(socket, SHUT_RDWR); | |
| 476 close(socket); | |
| 477 return; | |
| 478 } | |
| 479 } | |
| 480 } | |
| 481 } | |
| 482 | |
| 483 | |
| 484 //////////////////////////////////////////////// | |
| 485 // ask a dns question and get an A record answer - we don't try | |
| 486 // very hard, just using the default resolver retry settings. | |
| 487 // If we cannot get an answer, we just accept the mail. | |
| 488 // | |
| 489 // | |
| 490 int dns_interface(mlfiPriv &priv, char *question, bool maybe_ip, ns_map *nameservers); | |
| 491 int dns_interface(mlfiPriv &priv, char *question, bool maybe_ip, ns_map *nameservers) { | |
| 492 // this part can be done without locking the resolver mutex. Each | |
| 493 // milter thread is talking over its own socket to a separate resolver | |
| 494 // process, which does the actual dns resolution. | |
| 495 if (priv.err) return 0; // cannot ask more questions on this socket. | |
| 496 priv.my_write(question, strlen(question)+1); // write the question including the null terminator | |
| 497 glommer glom; | |
| 498 char *buf = (char *)&glom; | |
| 499 priv.my_read(buf, sizeof(glom.length)); | |
| 500 buf += sizeof(glom.length); | |
| 501 ///char text[1000]; | |
| 502 ///snprintf(text, sizeof(text), "!!milter thread wrote question %s and has answer length %d", question, glom.length); | |
| 503 ///my_syslog(text); | |
| 504 if ((glom.length < 0) || (glom.length > sizeof(glom.answer))) { | |
| 505 priv.err = true; | |
| 506 return 0; // cannot process overlarge answers | |
| 507 } | |
| 508 priv.my_read(buf, glom.length); | |
| 509 | |
| 510 #ifdef NS_PACKETSZ | |
| 511 // now we need to lock the resolver mutex to keep the milter threads from | |
| 512 // stepping on each other while parsing the dns answer. | |
| 513 int ret_address = 0; | |
| 514 pthread_mutex_lock(&resolve_mutex); | |
| 515 if (glom.length > 0) { | |
| 516 // parse the answer | |
| 517 ns_msg handle; | |
| 518 ns_rr rr; | |
| 519 if (ns_initparse(glom.answer, glom.length, &handle) == 0) { | |
| 520 // look for ns names | |
| 521 if (nameservers) { | |
| 522 ns_map &ns = *nameservers; | |
| 523 int rrnum = 0; | |
| 524 while (ns_parserr(&handle, ns_s_ns, rrnum++, &rr) == 0) { | |
| 525 if (ns_rr_type(rr) == ns_t_ns) { | |
| 526 char nam[NS_MAXDNAME+1]; | |
| 527 char *n = nam; | |
| 528 const u_char *p = ns_rr_rdata(rr); | |
| 529 while (((n-nam) < NS_MAXDNAME) && ((p-glom.answer) < glom.length) && *p) { | |
| 530 size_t s = *(p++); | |
| 531 if (s > 191) { | |
| 532 // compression pointer | |
| 533 s = (s-192)*256 + *(p++); | |
| 534 if (s >= glom.length) break; // pointer outside bounds of answer | |
| 535 p = glom.answer + s; | |
| 536 s = *(p++); | |
| 537 } | |
| 538 if (s > 0) { | |
| 539 if ((n-nam) >= (NS_MAXDNAME-s)) break; // destination would overflow name buffer | |
| 540 if ((p-glom.answer) >= (glom.length-s)) break; // source outside bounds of answer | |
| 541 memcpy(n, p, s); | |
| 542 n += s; | |
| 543 p += s; | |
| 544 *(n++) = '.'; | |
| 545 } | |
| 546 } | |
| 547 if (n-nam) n--; // remove trailing . | |
| 548 *n = '\0'; // null terminate it | |
| 549 ns.add(nam, question); // ns host to lookup later | |
| 550 } | |
| 551 } | |
| 552 rrnum = 0; | |
| 553 while (ns_parserr(&handle, ns_s_ar, rrnum++, &rr) == 0) { | |
| 554 if (ns_rr_type(rr) == ns_t_a) { | |
| 555 char* nam = (char*)ns_rr_name(rr); | |
| 556 ns_mapper::iterator i = ns.ns_ip.find(nam); | |
| 557 if (i != ns.ns_ip.end()) { | |
| 558 // we want this ip address | |
| 559 int address; | |
| 560 memcpy(&address, ns_rr_rdata(rr), sizeof(address)); | |
| 561 ns.ns_ip[nam] = address; | |
| 562 } | |
| 563 } | |
| 564 } | |
| 565 } | |
| 566 int rrnum = 0; | |
| 567 while (ns_parserr(&handle, ns_s_an, rrnum++, &rr) == 0) { | |
| 568 if (ns_rr_type(rr) == ns_t_a) { | |
| 569 int address; | |
| 570 memcpy(&address, ns_rr_rdata(rr), sizeof(address)); | |
| 571 ret_address = address; | |
| 572 } | |
| 573 } | |
| 574 } | |
| 575 } | |
| 576 if (maybe_ip && !ret_address) { | |
| 577 // might be a bare ip address | |
| 578 in_addr ip; | |
| 579 if (inet_aton(question, &ip)) { | |
| 580 ret_address = ip.s_addr; | |
| 581 } | |
| 582 } | |
| 583 pthread_mutex_unlock(&resolve_mutex); | |
| 584 return ret_address; | |
| 585 #else | |
| 586 return glom.answer; | |
| 587 #endif | |
| 588 } | |
| 589 | |
| 590 | |
| 591 //////////////////////////////////////////////// | |
| 592 // check a single dnsbl | |
| 593 // | |
| 594 bool check_single(mlfiPriv &priv, int ip, char *suffix); | |
| 595 bool check_single(mlfiPriv &priv, int ip, char *suffix) { | |
| 596 // make a dns question | |
| 597 const u_char *src = (const u_char *)&ip; | |
| 598 if (src[0] == 127) return false; // don't do dns lookups on localhost | |
| 599 #ifdef NS_MAXDNAME | |
| 600 char question[NS_MAXDNAME]; | |
| 601 #else | |
| 602 char question[1000]; | |
| 603 #endif | |
| 604 snprintf(question, sizeof(question), "%u.%u.%u.%u.%s.", src[3], src[2], src[1], src[0], suffix); | |
| 605 // ask the question, if we get an A record it implies a blacklisted ip address | |
| 606 return dns_interface(priv, question, false, NULL); | |
| 607 } | |
| 608 | |
| 609 | |
| 610 //////////////////////////////////////////////// | |
| 611 // check a single dnsbl | |
| 612 // | |
| 613 bool check_single(mlfiPriv &priv, int ip, DNSBL &bl); | |
| 614 bool check_single(mlfiPriv &priv, int ip, DNSBL &bl) { | |
| 615 return check_single(priv, ip, bl.suffix); | |
| 616 } | |
| 617 | |
| 618 | |
| 619 //////////////////////////////////////////////// | |
| 620 // check the dnsbls specified for this recipient | |
| 621 // | |
| 622 bool check_dnsbl(mlfiPriv &priv, dnsblp_list &dnsbll, DNSBLP &rejectlist); | |
| 623 bool check_dnsbl(mlfiPriv &priv, dnsblp_list &dnsbll, DNSBLP &rejectlist) { | |
| 624 for (dnsblp_list::iterator i=dnsbll.begin(); i!=dnsbll.end(); i++) { | |
| 625 DNSBLP dp = *i; // non null by construction | |
| 626 bool st; | |
| 627 map<DNSBLP, bool>::iterator f = priv.checked.find(dp); | |
| 628 if (f == priv.checked.end()) { | |
| 629 // have not checked this list yet | |
| 630 st = check_single(priv, priv.ip, *dp); | |
| 631 rejectlist = dp; | |
| 632 priv.checked[dp] = st; | |
| 633 } | |
| 634 else { | |
| 635 st = (*f).second; | |
| 636 rejectlist = (*f).first; | |
| 637 } | |
| 638 if (st) return st; | |
| 639 } | |
| 640 return false; | |
| 641 } | |
| 642 | |
| 643 | |
| 644 //////////////////////////////////////////////// | |
| 645 // check the hosts from the body against the content dnsbl | |
| 646 // | |
| 647 bool check_hosts(mlfiPriv &priv, bool random, int limit, char *&host, int &ip); | |
| 648 bool check_hosts(mlfiPriv &priv, bool random, int limit, char *&host, int &ip) { | |
| 649 CONFIG &dc = *priv.pc; | |
| 650 string_set &hosts = priv.memory->get_hosts(); | |
| 651 string_set &ignore = *priv.content_host_ignore; | |
| 652 char *suffix = priv.content_suffix; | |
| 653 | |
| 654 int count = 0; | |
| 655 int cnt = hosts.size(); // number of hosts we could look at | |
| 656 int_set ips; | |
| 657 ns_map nameservers; | |
| 658 for (string_set::iterator i=hosts.begin(); i!=hosts.end(); i++) { | |
| 659 host = *i; // a reference into hosts, which will live until this smtp transaction is closed | |
| 660 | |
| 661 // don't bother looking up hosts on the ignore list | |
| 662 string_set::iterator j = ignore.find(host); | |
| 663 if (j != ignore.end()) continue; | |
| 664 | |
| 665 // try to only look at limit/cnt fraction of the available cnt host names in random mode | |
| 666 if ((cnt > limit) && (limit > 0) && random) { | |
| 667 int r = rand() % cnt; | |
| 668 if (r >= limit) { | |
| 669 if (debug_syslog > 2) { | |
| 670 char buf[maxlen]; | |
| 671 snprintf(buf, sizeof(buf), "host %s skipped", host); | |
| 672 my_syslog(&priv, buf); | |
| 673 } | |
| 674 continue; | |
| 675 } | |
| 676 } | |
| 677 count++; | |
| 678 ip = dns_interface(priv, host, true, &nameservers); | |
| 679 if (debug_syslog > 2) { | |
| 680 char buf[maxlen]; | |
| 681 if (ip) { | |
| 682 char adr[sizeof "255.255.255.255"]; | |
| 683 adr[0] = '\0'; | |
| 684 inet_ntop(AF_INET, (const u_char *)&ip, adr, sizeof(adr)); | |
| 685 snprintf(buf, sizeof(buf), "host %s found at %s", host, adr); | |
| 686 } | |
| 687 else { | |
| 688 snprintf(buf, sizeof(buf), "host %s not found", host); | |
| 689 } | |
| 690 my_syslog(&priv, buf); | |
| 691 } | |
| 692 if (ip) { | |
| 693 int_set::iterator i = ips.find(ip); | |
| 694 if (i == ips.end()) { | |
| 695 ips.insert(ip); | |
| 696 if (check_single(priv, ip, suffix)) { | |
| 697 return true; | |
| 698 } | |
| 699 } | |
| 700 } | |
| 701 } | |
| 702 limit *= 4; // allow average of 3 ns per host name | |
| 703 for (ns_mapper::iterator i=nameservers.ns_ip.begin(); i!=nameservers.ns_ip.end(); i++) { | |
| 704 count++; | |
| 705 if ((count > limit) && (limit > 0)) { | |
| 706 if (random) continue; // don't complain | |
| 707 return true; | |
| 708 } | |
| 709 host = (*i).first; // a transient reference that needs to be replaced before we return it | |
| 710 ip = (*i).second; | |
| 711 if (!ip) ip = dns_interface(priv, host, false, NULL); | |
| 712 if (debug_syslog > 2) { | |
| 713 char buf[maxlen]; | |
| 714 if (ip) { | |
| 715 char adr[sizeof "255.255.255.255"]; | |
| 716 adr[0] = '\0'; | |
| 717 inet_ntop(AF_INET, (const u_char *)&ip, adr, sizeof(adr)); | |
| 718 snprintf(buf, sizeof(buf), "ns %s found at %s", host, adr); | |
| 719 } | |
| 720 else { | |
| 721 snprintf(buf, sizeof(buf), "ns %s not found", host); | |
| 722 } | |
| 723 my_syslog(&priv, buf); | |
| 724 } | |
| 725 if (ip) { | |
| 726 int_set::iterator i = ips.find(ip); | |
| 727 if (i == ips.end()) { | |
| 728 ips.insert(ip); | |
| 729 if (check_single(priv, ip, suffix)) { | |
| 730 string_map::iterator j = nameservers.ns_host.find(host); | |
| 731 if (j != nameservers.ns_host.end()) { | |
| 732 char *refer = (*j).second; | |
| 733 char buf[maxlen]; | |
| 734 snprintf(buf, sizeof(buf), "%s with nameserver %s", refer, host); | |
| 735 host = register_string(hosts, buf); // put a copy into hosts, and return that reference | |
| 736 } | |
| 737 else { | |
| 738 host = register_string(hosts, host); // put a copy into hosts, and return that reference | |
| 739 } | |
| 740 return true; | |
| 741 } | |
| 742 } | |
| 743 } | |
| 744 } | |
| 745 return false; | |
| 746 } | |
| 747 | |
| 748 | |
| 749 //////////////////////////////////////////////// | |
| 750 // this email address is passed in from sendmail, and will | |
| 751 // always be enclosed in <>. It may have mixed case, just | |
| 752 // as the mail client sent it. We dup the string and convert | |
| 753 // the duplicate to lower case. | |
| 754 // | |
| 755 char *to_lower_string(char *email); | |
| 756 char *to_lower_string(char *email) { | |
| 757 int n = strlen(email)-2; | |
| 758 if (n < 1) return strdup(email); | |
| 759 char *key = strdup(email+1); | |
| 760 key[n] = '\0'; | |
| 761 for (int i=0; i<n; i++) key[i] = tolower(key[i]); | |
| 762 return key; | |
| 763 } | |
| 764 | |
| 765 | |
| 766 //////////////////////////////////////////////// | |
| 767 // start of sendmail milter interfaces | |
| 768 // | |
| 769 sfsistat mlfi_connect(SMFICTX *ctx, char *hostname, _SOCK_ADDR *hostaddr) | |
| 770 { | |
| 771 // allocate some private memory | |
| 772 mlfiPriv *priv = new mlfiPriv; | |
| 773 if (hostaddr->sa_family == AF_INET) { | |
| 774 priv->ip = ((struct sockaddr_in *)hostaddr)->sin_addr.s_addr; | |
| 775 } | |
| 776 | |
| 777 // save the private data | |
| 778 smfi_setpriv(ctx, (void*)priv); | |
| 779 | |
| 780 // continue processing | |
| 781 return SMFIS_CONTINUE; | |
| 782 } | |
| 783 | |
| 784 sfsistat mlfi_envfrom(SMFICTX *ctx, char **from) | |
| 785 { | |
|
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786 mlfiPriv &priv = *MLFIPRIV; |
| 89 | 787 priv.mailaddr = to_lower_string(from[0]); |
| 788 priv.authenticated = (smfi_getsymval(ctx, "{auth_authen}") != NULL); | |
| 789 return SMFIS_CONTINUE; | |
| 790 } | |
| 791 | |
| 792 sfsistat mlfi_envrcpt(SMFICTX *ctx, char **rcpt) | |
| 793 { | |
| 794 DNSBLP rejectlist = NULL; // list that caused the reject | |
| 795 mlfiPriv &priv = *MLFIPRIV; | |
| 796 CONFIG &dc = *priv.pc; | |
| 797 if (!priv.queueid) priv.queueid = strdup(smfi_getsymval(ctx, "i")); | |
| 798 char *rcptaddr = rcpt[0]; | |
| 799 char *loto = to_lower_string(rcptaddr); | |
| 800 CONTEXT &con = *(dc.find_context(loto)->find_context(priv.mailaddr)); | |
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801 VERIFYP ver = con.find_verify(loto); |
| 89 | 802 if (debug_syslog > 1) { |
| 803 char buf[maxlen]; | |
| 804 char msg[maxlen]; | |
| 805 snprintf(msg, sizeof(msg), "from <%s> to <%s> using context %s", priv.mailaddr, loto, con.get_full_name(buf,maxlen)); | |
| 806 my_syslog(&priv, msg); | |
| 807 } | |
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808 free(loto); |
| 89 | 809 char *fromvalue = con.find_from(priv.mailaddr); |
| 810 status st; | |
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811 if (priv.authenticated) { |
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812 st = white; |
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813 } |
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814 else if (fromvalue == token_black) { |
| 89 | 815 st = black; |
| 816 } | |
| 817 else if (fromvalue == token_white) { | |
| 818 st = white; | |
| 819 } | |
| 820 else { | |
| 821 // check the dns based lists | |
| 822 st = (check_dnsbl(priv, con.get_dnsbl_list(), rejectlist)) ? reject : oksofar; | |
| 823 } | |
| 824 if (st == reject) { | |
| 825 // reject the recipient based on some dnsbl | |
| 826 char adr[sizeof "255.255.255.255"]; | |
| 827 adr[0] = '\0'; | |
| 828 inet_ntop(AF_INET, (const u_char *)&priv.ip, adr, sizeof(adr)); | |
| 829 char buf[maxlen]; | |
| 830 snprintf(buf, sizeof(buf), rejectlist->message, adr, adr); | |
| 831 smfi_setreply(ctx, "550", "5.7.1", buf); | |
| 832 return SMFIS_REJECT; | |
| 833 } | |
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834 if (st == black) { |
| 89 | 835 // reject the recipient based on blacklisting either from or to |
| 836 smfi_setreply(ctx, "550", "5.7.1", "no such user"); | |
| 837 return SMFIS_REJECT; | |
| 838 } | |
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839 if (ver && (st != white)) { |
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840 // try to verify this from/to pair of addresses since it is not explicitly whitelisted |
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841 char *loto = to_lower_string(rcptaddr); |
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842 bool rc = ver->ok(priv.mailaddr, loto); |
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843 free(loto); |
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844 if (!rc) { |
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845 smfi_setreply(ctx, "550", "5.7.1", "no such user"); |
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846 return SMFIS_REJECT; |
| 89 | 847 } |
| 848 } | |
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849 // accept the recipient |
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850 if (!con.get_content_filtering()) st = white; |
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851 if (st == oksofar) { |
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852 // but remember the non-whites |
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853 priv.need_content_filter(rcptaddr, con); |
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854 priv.only_whites = false; |
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855 } |
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856 if (st == white) { |
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857 priv.have_whites = true; |
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858 } |
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859 return SMFIS_CONTINUE; |
| 89 | 860 } |
| 861 | |
| 862 sfsistat mlfi_body(SMFICTX *ctx, u_char *data, size_t len) | |
| 863 { | |
| 864 mlfiPriv &priv = *MLFIPRIV; | |
| 865 if (priv.authenticated) return SMFIS_CONTINUE; | |
| 866 if (priv.only_whites) return SMFIS_CONTINUE; | |
| 867 priv.scanner->scan(data, len); | |
| 868 return SMFIS_CONTINUE; | |
| 869 } | |
| 870 | |
| 871 sfsistat mlfi_eom(SMFICTX *ctx) | |
| 872 { | |
| 873 sfsistat rc; | |
| 874 mlfiPriv &priv = *MLFIPRIV; | |
| 875 CONFIG &dc = *priv.pc; | |
| 876 char *host = NULL; | |
| 877 int ip; | |
| 878 status st; | |
| 879 // process end of message | |
| 880 if (priv.authenticated || priv.only_whites) rc = SMFIS_CONTINUE; | |
| 881 else { | |
| 882 // assert env_to not empty | |
| 883 char buf[maxlen]; | |
| 884 char *msg = NULL; | |
| 885 string_set alive; | |
| 886 bool random = false; | |
| 887 int limit = 0; | |
| 888 for (context_map::iterator i=priv.env_to.begin(); i!=priv.env_to.end(); i++) { | |
| 889 char *rcpt = (*i).first; | |
| 890 CONTEXT &con = *((*i).second); | |
| 891 if (!con.acceptable_content(*priv.memory, msg)) { | |
| 892 // bad html tags or excessive hosts | |
| 893 smfi_delrcpt(ctx, rcpt); | |
| 894 } | |
| 895 else { | |
| 896 alive.insert(rcpt); | |
| 897 random |= con.get_host_random(); | |
| 898 limit = max(limit, con.get_host_limit()); | |
| 899 } | |
| 900 } | |
| 901 bool rejecting = alive.empty(); // if alive is empty, we must have set msg above in acceptable_content() | |
| 902 if (!rejecting) { | |
| 903 if (check_hosts(priv, random, limit, host, ip)) { | |
| 904 char adr[sizeof "255.255.255.255"]; | |
| 905 adr[0] = '\0'; | |
| 906 inet_ntop(AF_INET, (const u_char *)&ip, adr, sizeof(adr)); | |
| 907 snprintf(buf, sizeof(buf), priv.content_message, host, adr); | |
| 908 msg = buf; | |
| 909 rejecting = true; | |
| 910 } | |
| 911 } | |
| 912 if (!rejecting) { | |
| 913 rc = SMFIS_CONTINUE; | |
| 914 } | |
| 915 else if (!priv.have_whites) { | |
| 916 // can reject the entire message | |
| 917 smfi_setreply(ctx, "550", "5.7.1", msg); | |
| 918 rc = SMFIS_REJECT; | |
| 919 } | |
| 920 else { | |
| 921 // need to accept it but remove the recipients that don't want it | |
| 922 for (string_set::iterator i=alive.begin(); i!=alive.end(); i++) { | |
| 923 char *rcpt = *i; | |
| 924 smfi_delrcpt(ctx, rcpt); | |
| 925 } | |
| 926 rc = SMFIS_CONTINUE; | |
| 927 } | |
| 928 } | |
| 929 // reset for a new message on the same connection | |
| 930 mlfi_abort(ctx); | |
| 931 return rc; | |
| 932 } | |
| 933 | |
| 934 sfsistat mlfi_abort(SMFICTX *ctx) | |
| 935 { | |
| 936 mlfiPriv &priv = *MLFIPRIV; | |
| 937 priv.reset(); | |
| 938 return SMFIS_CONTINUE; | |
| 939 } | |
| 940 | |
| 941 sfsistat mlfi_close(SMFICTX *ctx) | |
| 942 { | |
| 943 mlfiPriv *priv = MLFIPRIV; | |
| 944 if (!priv) return SMFIS_CONTINUE; | |
| 945 delete priv; | |
| 946 smfi_setpriv(ctx, NULL); | |
| 947 return SMFIS_CONTINUE; | |
| 948 } | |
| 949 | |
| 950 struct smfiDesc smfilter = | |
| 951 { | |
| 952 "DNSBL", // filter name | |
| 953 SMFI_VERSION, // version code -- do not change | |
| 954 SMFIF_DELRCPT, // flags | |
| 955 mlfi_connect, // connection info filter | |
| 956 NULL, // SMTP HELO command filter | |
| 957 mlfi_envfrom, // envelope sender filter | |
| 958 mlfi_envrcpt, // envelope recipient filter | |
| 959 NULL, // header filter | |
| 960 NULL, // end of header | |
| 961 mlfi_body, // body block filter | |
| 962 mlfi_eom, // end of message | |
| 963 mlfi_abort, // message aborted | |
| 964 mlfi_close, // connection cleanup | |
| 965 }; | |
| 966 | |
| 967 | |
| 968 //////////////////////////////////////////////// | |
| 969 // reload the config | |
| 970 // | |
| 971 CONFIG* new_conf(); | |
| 972 CONFIG* new_conf() { | |
| 973 CONFIG *newc = new CONFIG; | |
| 974 pthread_mutex_lock(&config_mutex); | |
| 975 newc->generation = generation++; | |
| 976 pthread_mutex_unlock(&config_mutex); | |
| 977 if (debug_syslog) { | |
| 978 char buf[maxlen]; | |
| 979 snprintf(buf, sizeof(buf), "loading configuration generation %d", newc->generation); | |
| 980 my_syslog(buf); | |
| 981 } | |
| 982 if (load_conf(*newc, "dnsbl.conf")) { | |
| 983 newc->load_time = time(NULL); | |
| 984 return newc; | |
| 985 } | |
| 986 delete newc; | |
| 987 return NULL; | |
| 988 } | |
| 989 | |
| 990 | |
| 991 //////////////////////////////////////////////// | |
| 992 // thread to watch the old config files for changes | |
| 993 // and reload when needed. we also cleanup old | |
| 994 // configs whose reference count has gone to zero. | |
| 995 // | |
| 996 void* config_loader(void *arg); | |
| 997 void* config_loader(void *arg) { | |
| 998 typedef set<CONFIG *> configp_set; | |
| 999 configp_set old_configs; | |
| 1000 while (loader_run) { | |
| 1001 sleep(180); // look for modifications every 3 minutes | |
| 1002 if (!loader_run) break; | |
| 1003 CONFIG &dc = *config; | |
| 1004 time_t then = dc.load_time; | |
| 1005 struct stat st; | |
| 1006 bool reload = false; | |
| 1007 for (string_set::iterator i=dc.config_files.begin(); i!=dc.config_files.end(); i++) { | |
| 1008 char *fn = *i; | |
| 1009 if (stat(fn, &st)) reload = true; // file disappeared | |
| 1010 else if (st.st_mtime > then) reload = true; // file modified | |
| 1011 if (reload) break; | |
| 1012 } | |
| 1013 if (reload) { | |
| 1014 CONFIG *newc = new_conf(); | |
| 1015 if (newc) { | |
| 1016 // replace the global config pointer | |
| 1017 pthread_mutex_lock(&config_mutex); | |
| 1018 CONFIG *old = config; | |
| 1019 config = newc; | |
| 1020 pthread_mutex_unlock(&config_mutex); | |
| 1021 if (old) old_configs.insert(old); | |
| 1022 } | |
| 1023 else { | |
| 1024 // failed to load new config | |
| 1025 my_syslog("failed to load new configuration"); | |
| 1026 system("echo 'failed to load new dnsbl configuration from /etc/dnsbl' | mail -s 'error in /etc/dnsbl configuration' root"); | |
| 1027 // update the load time on the current config to prevent complaining every 3 minutes | |
| 1028 dc.load_time = time(NULL); | |
| 1029 } | |
| 1030 } | |
| 1031 // now look for old configs with zero ref counts | |
| 1032 for (configp_set::iterator i=old_configs.begin(); i!=old_configs.end(); ) { | |
| 1033 CONFIG *old = *i; | |
| 1034 if (!old->reference_count) { | |
| 1035 if (debug_syslog) { | |
| 1036 char buf[maxlen]; | |
| 1037 snprintf(buf, sizeof(buf), "freeing memory for old configuration generation %d", old->generation); | |
| 1038 my_syslog(buf); | |
| 1039 } | |
| 1040 delete old; // destructor does all the work | |
| 1041 old_configs.erase(i++); | |
| 1042 } | |
| 1043 else i++; | |
| 1044 } | |
| 1045 } | |
| 1046 return NULL; | |
| 1047 } | |
| 1048 | |
| 1049 | |
| 1050 void usage(char *prog); | |
| 1051 void usage(char *prog) | |
| 1052 { | |
| 1053 fprintf(stderr, "Usage: %s [-d [level]] [-c] [-s] [-e from|to] -r port -p sm-sock-addr [-t timeout]\n", prog); | |
| 1054 fprintf(stderr, "where port is for the connection to our own dns resolver processes\n"); | |
| 1055 fprintf(stderr, " and should be local-domain-socket-file-name\n"); | |
| 1056 fprintf(stderr, "where sm-sock-addr is for the connection to sendmail\n"); | |
| 1057 fprintf(stderr, " and should be one of\n"); | |
| 1058 fprintf(stderr, " inet:port@ip-address\n"); | |
| 1059 fprintf(stderr, " local:local-domain-socket-file-name\n"); | |
| 1060 fprintf(stderr, "-c will load and dump the config to stdout\n"); | |
| 1061 fprintf(stderr, "-s will stress test the config loading code by repeating the load/free cycle\n"); | |
| 1062 fprintf(stderr, " in an infinte loop.\n"); | |
|
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|
1063 fprintf(stderr, "-d will set the syslog message level, currently 0 to 3\n"); |
| 89 | 1064 fprintf(stderr, "-e will print the results of looking up the from and to addresses in the\n"); |
| 1065 fprintf(stderr, " current config. The | character is used to separate the from and to\n"); | |
| 1066 fprintf(stderr, " addresses in the argument to the -e switch\n"); | |
| 1067 } | |
| 1068 | |
| 1069 | |
| 1070 | |
| 1071 void setup_socket(char *sock); | |
| 1072 void setup_socket(char *sock) { | |
| 1073 unlink(sock); | |
| 1074 // sockaddr_un addr; | |
| 1075 // memset(&addr, '\0', sizeof addr); | |
| 1076 // addr.sun_family = AF_UNIX; | |
| 1077 // strncpy(addr.sun_path, sock, sizeof(addr.sun_path)-1); | |
| 1078 // int s = socket(AF_UNIX, SOCK_STREAM, 0); | |
| 1079 // bind(s, (sockaddr*)&addr, sizeof(addr)); | |
| 1080 // close(s); | |
| 1081 } | |
| 1082 | |
| 1083 | |
| 1084 /* | |
| 1085 * The signal handler function -- only gets called when a SIGCHLD | |
| 1086 * is received, ie when a child terminates | |
| 1087 */ | |
| 1088 void sig_chld(int signo) | |
| 1089 { | |
| 1090 int status; | |
| 1091 /* Wait for any child without blocking */ | |
| 1092 while (waitpid(-1, &status, WNOHANG) > 0) { | |
| 1093 // ignore child exit status, we only do this to cleanup zombies | |
| 1094 } | |
| 1095 } | |
| 1096 | |
| 1097 | |
| 1098 int main(int argc, char**argv) | |
| 1099 { | |
| 1100 token_init(); | |
| 1101 bool check = false; | |
| 1102 bool stress = false; | |
| 1103 bool setconn = false; | |
| 1104 bool setreso = false; | |
| 1105 char *email = NULL; | |
| 1106 int c; | |
| 1107 const char *args = "r:p:t:e:d:chs"; | |
| 1108 extern char *optarg; | |
| 1109 | |
| 1110 // Process command line options | |
| 1111 while ((c = getopt(argc, argv, args)) != -1) { | |
| 1112 switch (c) { | |
| 1113 case 'r': | |
| 1114 if (optarg == NULL || *optarg == '\0') { | |
| 1115 fprintf(stderr, "Illegal resolver socket: %s\n", optarg); | |
| 1116 exit(EX_USAGE); | |
| 1117 } | |
| 1118 resolver_port = strdup(optarg); | |
| 1119 setup_socket(resolver_port); | |
| 1120 setreso = true; | |
| 1121 break; | |
| 1122 | |
| 1123 case 'p': | |
| 1124 if (optarg == NULL || *optarg == '\0') { | |
| 1125 fprintf(stderr, "Illegal sendmail socket: %s\n", optarg); | |
| 1126 exit(EX_USAGE); | |
| 1127 } | |
| 1128 if (smfi_setconn(optarg) == MI_FAILURE) { | |
| 1129 fprintf(stderr, "smfi_setconn failed\n"); | |
| 1130 exit(EX_SOFTWARE); | |
| 1131 } | |
| 1132 if (strncasecmp(optarg, "unix:", 5) == 0) setup_socket(optarg + 5); | |
| 1133 else if (strncasecmp(optarg, "local:", 6) == 0) setup_socket(optarg + 6); | |
| 1134 setconn = true; | |
| 1135 break; | |
| 1136 | |
| 1137 case 't': | |
| 1138 if (optarg == NULL || *optarg == '\0') { | |
| 1139 fprintf(stderr, "Illegal timeout: %s\n", optarg); | |
| 1140 exit(EX_USAGE); | |
| 1141 } | |
| 1142 if (smfi_settimeout(atoi(optarg)) == MI_FAILURE) { | |
| 1143 fprintf(stderr, "smfi_settimeout failed\n"); | |
| 1144 exit(EX_SOFTWARE); | |
| 1145 } | |
| 1146 break; | |
| 1147 | |
| 1148 case 'e': | |
| 1149 if (email) free(email); | |
| 1150 email = strdup(optarg); | |
| 1151 break; | |
| 1152 | |
| 1153 case 'c': | |
| 1154 check = true; | |
| 1155 break; | |
| 1156 | |
| 1157 case 's': | |
| 1158 stress = true; | |
| 1159 break; | |
| 1160 | |
| 1161 case 'd': | |
| 1162 if (optarg == NULL || *optarg == '\0') debug_syslog = 1; | |
| 1163 else debug_syslog = atoi(optarg); | |
| 1164 break; | |
| 1165 | |
| 1166 case 'h': | |
| 1167 default: | |
| 1168 usage(argv[0]); | |
| 1169 exit(EX_USAGE); | |
| 1170 } | |
| 1171 } | |
| 1172 | |
| 1173 if (check) { | |
| 1174 use_syslog = false; | |
| 1175 debug_syslog = 10; | |
| 1176 CONFIG *conf = new_conf(); | |
| 1177 if (conf) { | |
| 1178 conf->dump(); | |
| 1179 delete conf; | |
| 1180 return 0; | |
| 1181 } | |
| 1182 else { | |
| 1183 return 1; // config failed to load | |
| 1184 } | |
| 1185 } | |
| 1186 | |
| 1187 if (stress) { | |
| 1188 fprintf(stdout, "stress testing\n"); | |
| 1189 while (1) { | |
| 1190 for (int i=0; i<10; i++) { | |
| 1191 CONFIG *conf = new_conf(); | |
| 1192 if (conf) delete conf; | |
| 1193 } | |
| 1194 fprintf(stdout, "."); | |
| 1195 fflush(stdout); | |
| 1196 sleep(1); | |
| 1197 } | |
| 1198 } | |
| 1199 | |
| 1200 if (email) { | |
| 1201 char *x = strchr(email, '|'); | |
| 1202 if (x) { | |
| 1203 *x = '\0'; | |
| 1204 char *from = strdup(email); | |
| 1205 char *to = strdup(x+1); | |
| 1206 use_syslog = false; | |
| 1207 CONFIG *conf = new_conf(); | |
| 1208 if (conf) { | |
| 1209 CONTEXTP con = conf->find_context(to); | |
| 1210 char buf[maxlen]; | |
| 1211 fprintf(stdout, "envelope to <%s> finds context %s\n", to, con->get_full_name(buf,maxlen)); | |
| 1212 CONTEXTP fc = con->find_context(from); | |
| 1213 fprintf(stdout, "envelope from <%s> finds context %s\n", from, fc->get_full_name(buf,maxlen)); | |
| 1214 char *st = fc->find_from(from); | |
| 1215 fprintf(stdout, "envelope from <%s> finds status %s\n", from, st); | |
| 1216 delete conf; | |
| 1217 } | |
| 1218 } | |
| 1219 return 0; | |
| 1220 } | |
| 1221 | |
| 1222 if (!setconn) { | |
| 1223 fprintf(stderr, "%s: Missing required -p argument\n", argv[0]); | |
| 1224 usage(argv[0]); | |
| 1225 exit(EX_USAGE); | |
| 1226 } | |
| 1227 | |
| 1228 if (!setreso) { | |
| 1229 fprintf(stderr, "%s: Missing required -r argument\n", argv[0]); | |
| 1230 usage(argv[0]); | |
| 1231 exit(EX_USAGE); | |
| 1232 } | |
| 1233 | |
| 1234 if (smfi_register(smfilter) == MI_FAILURE) { | |
| 1235 fprintf(stderr, "smfi_register failed\n"); | |
| 1236 exit(EX_UNAVAILABLE); | |
| 1237 } | |
| 1238 | |
| 1239 // switch to background mode | |
| 1240 if (daemon(1,0) < 0) { | |
| 1241 fprintf(stderr, "daemon() call failed\n"); | |
| 1242 exit(EX_UNAVAILABLE); | |
| 1243 } | |
| 1244 | |
| 1245 // write the pid | |
| 1246 const char *pidpath = "/var/run/dnsbl.pid"; | |
| 1247 unlink(pidpath); | |
| 1248 FILE *f = fopen(pidpath, "w"); | |
| 1249 if (f) { | |
| 1250 #ifdef linux | |
| 1251 // from a comment in the DCC source code: | |
| 1252 // Linux threads are broken. Signals given the | |
| 1253 // original process are delivered to only the | |
| 1254 // thread that happens to have that PID. The | |
| 1255 // sendmail libmilter thread that needs to hear | |
| 1256 // SIGINT and other signals does not, and that breaks | |
| 1257 // scripts that need to stop milters. | |
| 1258 // However, signaling the process group works. | |
| 1259 fprintf(f, "-%d\n", (u_int)getpgrp()); | |
| 1260 #else | |
| 1261 fprintf(f, "%d\n", (u_int)getpid()); | |
| 1262 #endif | |
| 1263 fclose(f); | |
| 1264 } | |
| 1265 | |
| 1266 // initialize the thread sync objects | |
| 1267 pthread_mutex_init(&config_mutex, 0); | |
| 1268 pthread_mutex_init(&syslog_mutex, 0); | |
| 1269 pthread_mutex_init(&resolve_mutex, 0); | |
| 1270 pthread_mutex_init(&fd_pool_mutex, 0); | |
| 1271 | |
| 1272 // drop root privs | |
| 1273 struct passwd *pw = getpwnam("dnsbl"); | |
| 1274 if (pw) { | |
| 1275 if (setgid(pw->pw_gid) == -1) { | |
| 1276 my_syslog("failed to switch to group dnsbl"); | |
| 1277 } | |
| 1278 if (setuid(pw->pw_uid) == -1) { | |
| 1279 my_syslog("failed to switch to user dnsbl"); | |
| 1280 } | |
| 1281 } | |
| 1282 | |
| 1283 // load the initial config | |
| 1284 config = new_conf(); | |
| 1285 if (!config) { | |
| 1286 my_syslog("failed to load initial configuration, quitting"); | |
| 1287 exit(1); | |
| 1288 } | |
| 1289 | |
| 1290 // fork off the resolver listener process | |
| 1291 pid_t child = fork(); | |
| 1292 if (child < 0) { | |
| 1293 my_syslog("failed to create resolver listener process"); | |
| 1294 exit(0); | |
| 1295 } | |
| 1296 if (child == 0) { | |
| 1297 // we are the child - dns resolver listener process | |
| 1298 resolver_socket = socket(AF_UNIX, SOCK_STREAM, 0); | |
| 1299 if (resolver_socket < 0) { | |
| 1300 my_syslog("child failed to create resolver socket"); | |
| 1301 exit(0); // failed | |
| 1302 } | |
| 1303 sockaddr_un server; | |
| 1304 memset(&server, '\0', sizeof(server)); | |
| 1305 server.sun_family = AF_UNIX; | |
| 1306 strncpy(server.sun_path, resolver_port, sizeof(server.sun_path)-1); | |
| 1307 //try to bind the address to the socket. | |
| 1308 if (bind(resolver_socket, (sockaddr *)&server, sizeof(server)) < 0) { | |
| 1309 // bind failed | |
| 1310 shutdown(resolver_socket, SHUT_RDWR); | |
| 1311 close(resolver_socket); | |
| 1312 my_syslog("child failed to bind resolver socket"); | |
| 1313 exit(0); // failed | |
| 1314 } | |
| 1315 //listen on the socket. | |
| 1316 if (listen(resolver_socket, 10) < 0) { | |
| 1317 // listen failed | |
| 1318 shutdown(resolver_socket, SHUT_RDWR); | |
| 1319 close(resolver_socket); | |
| 1320 my_syslog("child failed to listen to resolver socket"); | |
| 1321 exit(0); // failed | |
| 1322 } | |
| 1323 // setup sigchld handler to prevent zombies | |
| 1324 struct sigaction act; | |
| 1325 act.sa_handler = sig_chld; // Assign sig_chld as our SIGCHLD handler | |
| 1326 sigemptyset(&act.sa_mask); // We don't want to block any other signals in this example | |
| 1327 act.sa_flags = SA_NOCLDSTOP; // only want children that have terminated | |
| 1328 if (sigaction(SIGCHLD, &act, NULL) < 0) { | |
| 1329 my_syslog("child failed to setup SIGCHLD handler"); | |
| 1330 exit(0); // failed | |
| 1331 } | |
| 1332 while (true) { | |
| 1333 sockaddr_un client; | |
| 1334 socklen_t clientlen = sizeof(client); | |
| 1335 int s = accept(resolver_socket, (sockaddr *)&client, &clientlen); | |
| 1336 if (s > 0) { | |
| 1337 // accept worked, it did not get cancelled before we could accept it | |
| 1338 // fork off a process to handle this connection | |
| 1339 int newchild = fork(); | |
| 1340 if (newchild == 0) { | |
| 1341 // this is the worker process | |
| 1342 // child does not need the listening socket | |
| 1343 close(resolver_socket); | |
| 1344 process_resolver_requests(s); | |
| 1345 exit(0); | |
| 1346 } | |
| 1347 else { | |
| 1348 // this is the parent | |
| 1349 // parent does not need the accepted socket | |
| 1350 close(s); | |
| 1351 } | |
| 1352 } | |
| 1353 } | |
| 1354 exit(0); // make sure we don't fall thru. | |
| 1355 } | |
| 1356 else { | |
| 1357 sleep(2); // allow child to get started | |
| 1358 } | |
| 1359 | |
| 1360 // only create threads after the fork() in daemon | |
| 1361 pthread_t tid; | |
| 1362 if (pthread_create(&tid, 0, config_loader, 0)) | |
| 1363 my_syslog("failed to create config loader thread"); | |
| 1364 if (pthread_detach(tid)) | |
| 1365 my_syslog("failed to detach config loader thread"); | |
|
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diff
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1366 if (pthread_create(&tid, 0, verify_closer, 0)) |
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diff
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|
1367 my_syslog("failed to create verify closer thread"); |
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diff
changeset
|
1368 if (pthread_detach(tid)) |
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|
1369 my_syslog("failed to detach verify closer thread"); |
| 89 | 1370 |
| 1371 time_t starting = time(NULL); | |
| 1372 int rc = smfi_main(); | |
| 1373 if ((rc != MI_SUCCESS) && (time(NULL) > starting+5*60)) { | |
| 1374 my_syslog("trying to restart after smfi_main()"); | |
| 1375 loader_run = false; // eventually the config loader thread will terminate | |
| 1376 execvp(argv[0], argv); | |
| 1377 } | |
| 1378 exit((rc == MI_SUCCESS) ? 0 : EX_UNAVAILABLE); | |
| 1379 } | |
| 1380 |