contrib/sendmail-8.13.8/libmilter/listener.c

   1 /*
   2  *  Copyright (c) 1999-2006 Sendmail, Inc. and its suppliers.
   3  *      All rights reserved.
   4  *
   5  * By using this file, you agree to the terms and conditions set
   6  * forth in the LICENSE file which can be found at the top level of
   7  * the sendmail distribution.
   8  *
   9  */
  10
  11 #include <sm/gen.h>
  12 SM_RCSID("@(#)$Id: listener.c,v 8.115 2006/01/24 00:48:39 ca Exp $")
  13
  14 /*
  15 **  listener.c -- threaded network listener
  16 */
  17
  18 #include "libmilter.h"
  19 #include <sm/errstring.h>
  20
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23
  24
  25 # if NETINET || NETINET6
  26 #  include <arpa/inet.h>
  27 # endif /* NETINET || NETINET6 */
  28
  29 static smutex_t L_Mutex;
  30 static int L_family;
  31 static SOCKADDR_LEN_T L_socksize;
  32 static socket_t listenfd = INVALID_SOCKET;
  33
  34 static socket_t mi_milteropen __P((char *, int, bool, char *));
  35 static void *mi_thread_handle_wrapper __P((void *));
  36
  37 /*
  38 **  MI_OPENSOCKET -- create the socket where this filter and the MTA will meet
  39 **
  40 **      Parameters:
  41 **              conn -- connection description
  42 **              backlog -- listen backlog
  43 **              dbg -- debug level
  44 **              rmsocket -- if true, try to unlink() the socket first
  45 **                      (UNIX domain sockets only)
  46 **              smfi -- filter structure to use
  47 **
  48 **      Return value:
  49 **              MI_SUCCESS/MI_FAILURE
  50 */
  51
  52 int
  53 mi_opensocket(conn, backlog, dbg, rmsocket, smfi)
  54         char *conn;
  55         int backlog;
  56         int dbg;
  57         bool rmsocket;
  58         smfiDesc_ptr smfi;
  59 {
  60         if (smfi == NULL || conn == NULL)
  61                 return MI_FAILURE;
  62
  63         if (ValidSocket(listenfd))
  64                 return MI_SUCCESS;
  65
  66         if (dbg > 0)
  67         {
  68                 smi_log(SMI_LOG_DEBUG,
  69                         "%s: Opening listen socket on conn %s",
  70                         smfi->xxfi_name, conn);
  71         }
  72         (void) smutex_init(&L_Mutex);
  73         (void) smutex_lock(&L_Mutex);
  74         listenfd = mi_milteropen(conn, backlog, rmsocket, smfi->xxfi_name);
  75         if (!ValidSocket(listenfd))
  76         {
  77                 smi_log(SMI_LOG_FATAL,
  78                         "%s: Unable to create listening socket on conn %s",
  79                         smfi->xxfi_name, conn);
  80                 (void) smutex_unlock(&L_Mutex);
  81                 return MI_FAILURE;
  82         }
  83 #if !SM_CONF_POLL
  84         if (!SM_FD_OK_SELECT(listenfd))
  85         {
  86                 smi_log(SMI_LOG_ERR, "%s: fd %d is larger than FD_SETSIZE %d",
  87                         smfi->xxfi_name, listenfd, FD_SETSIZE);
  88                 (void) smutex_unlock(&L_Mutex);
  89                 return MI_FAILURE;
  90         }
  91 #endif /* !SM_CONF_POLL */
  92         (void) smutex_unlock(&L_Mutex);
  93         return MI_SUCCESS;
  94 }
  95
  96 /*
  97 **  MI_MILTEROPEN -- setup socket to listen on
  98 **
  99 **      Parameters:
 100 **              conn -- connection description
 101 **              backlog -- listen backlog
 102 **              rmsocket -- if true, try to unlink() the socket first
 103 **                      (UNIX domain sockets only)
 104 **              name -- name for logging
 105 **
 106 **      Returns:
 107 **              socket upon success, error code otherwise.
 108 **
 109 **      Side effect:
 110 **              sets sockpath if UNIX socket.
 111 */
 112
 113 #if NETUNIX
 114 static char     *sockpath = NULL;
 115 #endif /* NETUNIX */
 116
 117 static socket_t
 118 mi_milteropen(conn, backlog, rmsocket, name)
 119         char *conn;
 120         int backlog;
 121         bool rmsocket;
 122         char *name;
 123 {
 124         socket_t sock;
 125         int sockopt = 1;
 126         int fdflags;
 127         size_t len = 0;
 128         char *p;
 129         char *colon;
 130         char *at;
 131         SOCKADDR addr;
 132
 133         if (conn == NULL || conn[0] == '\0')
 134         {
 135                 smi_log(SMI_LOG_ERR, "%s: empty or missing socket information",
 136                         name);
 137                 return INVALID_SOCKET;
 138         }
 139         (void) memset(&addr, '\0', sizeof addr);
 140
 141         /* protocol:filename or protocol:port@host */
 142         p = conn;
 143         colon = strchr(p, ':');
 144         if (colon != NULL)
 145         {
 146                 *colon = '\0';
 147
 148                 if (*p == '\0')
 149                 {
 150 #if NETUNIX
 151                         /* default to AF_UNIX */
 152                         addr.sa.sa_family = AF_UNIX;
 153                         L_socksize = sizeof (struct sockaddr_un);
 154 #else /* NETUNIX */
 155 # if NETINET
 156                         /* default to AF_INET */
 157                         addr.sa.sa_family = AF_INET;
 158                         L_socksize = sizeof addr.sin;
 159 # else /* NETINET */
 160 #  if NETINET6
 161                         /* default to AF_INET6 */
 162                         addr.sa.sa_family = AF_INET6;
 163                         L_socksize = sizeof addr.sin6;
 164 #  else /* NETINET6 */
 165                         /* no protocols available */
 166                         smi_log(SMI_LOG_ERR,
 167                                 "%s: no valid socket protocols available",
 168                                 name);
 169                         return INVALID_SOCKET;
 170 #  endif /* NETINET6 */
 171 # endif /* NETINET */
 172 #endif /* NETUNIX */
 173                 }
 174 #if NETUNIX
 175                 else if (strcasecmp(p, "unix") == 0 ||
 176                          strcasecmp(p, "local") == 0)
 177                 {
 178                         addr.sa.sa_family = AF_UNIX;
 179                         L_socksize = sizeof (struct sockaddr_un);
 180                 }
 181 #endif /* NETUNIX */
 182 #if NETINET
 183                 else if (strcasecmp(p, "inet") == 0)
 184                 {
 185                         addr.sa.sa_family = AF_INET;
 186                         L_socksize = sizeof addr.sin;
 187                 }
 188 #endif /* NETINET */
 189 #if NETINET6
 190                 else if (strcasecmp(p, "inet6") == 0)
 191                 {
 192                         addr.sa.sa_family = AF_INET6;
 193                         L_socksize = sizeof addr.sin6;
 194                 }
 195 #endif /* NETINET6 */
 196                 else
 197                 {
 198                         smi_log(SMI_LOG_ERR, "%s: unknown socket type %s",
 199                                 name, p);
 200                         return INVALID_SOCKET;
 201                 }
 202                 *colon++ = ':';
 203         }
 204         else
 205         {
 206                 colon = p;
 207 #if NETUNIX
 208                 /* default to AF_UNIX */
 209                 addr.sa.sa_family = AF_UNIX;
 210                 L_socksize = sizeof (struct sockaddr_un);
 211 #else /* NETUNIX */
 212 # if NETINET
 213                 /* default to AF_INET */
 214                 addr.sa.sa_family = AF_INET;
 215                 L_socksize = sizeof addr.sin;
 216 # else /* NETINET */
 217 #  if NETINET6
 218                 /* default to AF_INET6 */
 219                 addr.sa.sa_family = AF_INET6;
 220                 L_socksize = sizeof addr.sin6;
 221 #  else /* NETINET6 */
 222                 smi_log(SMI_LOG_ERR, "%s: unknown socket type %s",
 223                         name, p);
 224                 return INVALID_SOCKET;
 225 #  endif /* NETINET6 */
 226 # endif /* NETINET */
 227 #endif /* NETUNIX */
 228         }
 229
 230 #if NETUNIX
 231         if (addr.sa.sa_family == AF_UNIX)
 232         {
 233 # if 0
 234                 long sff = SFF_SAFEDIRPATH|SFF_OPENASROOT|SFF_NOLINK|SFF_CREAT|SFF_MUSTOWN;
 235 # endif /* 0 */
 236
 237                 at = colon;
 238                 len = strlen(colon) + 1;
 239                 if (len >= sizeof addr.sunix.sun_path)
 240                 {
 241                         errno = EINVAL;
 242                         smi_log(SMI_LOG_ERR, "%s: UNIX socket name %s too long",
 243                                 name, colon);
 244                         return INVALID_SOCKET;
 245                 }
 246                 (void) sm_strlcpy(addr.sunix.sun_path, colon,
 247                                 sizeof addr.sunix.sun_path);
 248 # if 0
 249                 errno = safefile(colon, RunAsUid, RunAsGid, RunAsUserName, sff,
 250                                  S_IRUSR|S_IWUSR, NULL);
 251
 252                 /* if not safe, don't create */
 253                 if (errno != 0)
 254                 {
 255                         smi_log(SMI_LOG_ERR,
 256                                 "%s: UNIX socket name %s unsafe",
 257                                 name, colon);
 258                         return INVALID_SOCKET;
 259                 }
 260 # endif /* 0 */
 261         }
 262 #endif /* NETUNIX */
 263
 264 #if NETINET || NETINET6
 265         if (
 266 # if NETINET
 267             addr.sa.sa_family == AF_INET
 268 # endif /* NETINET */
 269 # if NETINET && NETINET6
 270             ||
 271 # endif /* NETINET && NETINET6 */
 272 # if NETINET6
 273             addr.sa.sa_family == AF_INET6
 274 # endif /* NETINET6 */
 275            )
 276         {
 277                 unsigned short port;
 278
 279                 /* Parse port@host */
 280                 at = strchr(colon, '@');
 281                 if (at == NULL)
 282                 {
 283                         switch (addr.sa.sa_family)
 284                         {
 285 # if NETINET
 286                           case AF_INET:
 287                                 addr.sin.sin_addr.s_addr = INADDR_ANY;
 288                                 break;
 289 # endif /* NETINET */
 290
 291 # if NETINET6
 292                           case AF_INET6:
 293                                 addr.sin6.sin6_addr = in6addr_any;
 294                                 break;
 295 # endif /* NETINET6 */
 296                         }
 297                 }
 298                 else
 299                         *at = '\0';
 300
 301                 if (isascii(*colon) && isdigit(*colon))
 302                         port = htons((unsigned short) atoi(colon));
 303                 else
 304                 {
 305 # ifdef NO_GETSERVBYNAME
 306                         smi_log(SMI_LOG_ERR, "%s: invalid port number %s",
 307                                 name, colon);
 308                         return INVALID_SOCKET;
 309 # else /* NO_GETSERVBYNAME */
 310                         register struct servent *sp;
 311
 312                         sp = getservbyname(colon, "tcp");
 313                         if (sp == NULL)
 314                         {
 315                                 smi_log(SMI_LOG_ERR,
 316                                         "%s: unknown port name %s",
 317                                         name, colon);
 318                                 return INVALID_SOCKET;
 319                         }
 320                         port = sp->s_port;
 321 # endif /* NO_GETSERVBYNAME */
 322                 }
 323                 if (at != NULL)
 324                 {
 325                         *at++ = '@';
 326                         if (*at == '[')
 327                         {
 328                                 char *end;
 329
 330                                 end = strchr(at, ']');
 331                                 if (end != NULL)
 332                                 {
 333                                         bool found = false;
 334 # if NETINET
 335                                         unsigned long hid = INADDR_NONE;
 336 # endif /* NETINET */
 337 # if NETINET6
 338                                         struct sockaddr_in6 hid6;
 339 # endif /* NETINET6 */
 340
 341                                         *end = '\0';
 342 # if NETINET
 343                                         if (addr.sa.sa_family == AF_INET &&
 344                                             (hid = inet_addr(&at[1])) != INADDR_NONE)
 345                                         {
 346                                                 addr.sin.sin_addr.s_addr = hid;
 347                                                 addr.sin.sin_port = port;
 348                                                 found = true;
 349                                         }
 350 # endif /* NETINET */
 351 # if NETINET6
 352                                         (void) memset(&hid6, '\0', sizeof hid6);
 353                                         if (addr.sa.sa_family == AF_INET6 &&
 354                                             mi_inet_pton(AF_INET6, &at[1],
 355                                                          &hid6.sin6_addr) == 1)
 356                                         {
 357                                                 addr.sin6.sin6_addr = hid6.sin6_addr;
 358                                                 addr.sin6.sin6_port = port;
 359                                                 found = true;
 360                                         }
 361 # endif /* NETINET6 */
 362                                         *end = ']';
 363                                         if (!found)
 364                                         {
 365                                                 smi_log(SMI_LOG_ERR,
 366                                                         "%s: Invalid numeric domain spec \"%s\"",
 367                                                         name, at);
 368                                                 return INVALID_SOCKET;
 369                                         }
 370                                 }
 371                                 else
 372                                 {
 373                                         smi_log(SMI_LOG_ERR,
 374                                                 "%s: Invalid numeric domain spec \"%s\"",
 375                                                 name, at);
 376                                         return INVALID_SOCKET;
 377                                 }
 378                         }
 379                         else
 380                         {
 381                                 struct hostent *hp = NULL;
 382
 383                                 hp = mi_gethostbyname(at, addr.sa.sa_family);
 384                                 if (hp == NULL)
 385                                 {
 386                                         smi_log(SMI_LOG_ERR,
 387                                                 "%s: Unknown host name %s",
 388                                                 name, at);
 389                                         return INVALID_SOCKET;
 390                                 }
 391                                 addr.sa.sa_family = hp->h_addrtype;
 392                                 switch (hp->h_addrtype)
 393                                 {
 394 # if NETINET
 395                                   case AF_INET:
 396                                         (void) memmove(&addr.sin.sin_addr,
 397                                                        hp->h_addr,
 398                                                        INADDRSZ);
 399                                         addr.sin.sin_port = port;
 400                                         break;
 401 # endif /* NETINET */
 402
 403 # if NETINET6
 404                                   case AF_INET6:
 405                                         (void) memmove(&addr.sin6.sin6_addr,
 406                                                        hp->h_addr,
 407                                                        IN6ADDRSZ);
 408                                         addr.sin6.sin6_port = port;
 409                                         break;
 410 # endif /* NETINET6 */
 411
 412                                   default:
 413                                         smi_log(SMI_LOG_ERR,
 414                                                 "%s: Unknown protocol for %s (%d)",
 415                                                 name, at, hp->h_addrtype);
 416                                         return INVALID_SOCKET;
 417                                 }
 418 # if NETINET6
 419                                 freehostent(hp);
 420 # endif /* NETINET6 */
 421                         }
 422                 }
 423                 else
 424                 {
 425                         switch (addr.sa.sa_family)
 426                         {
 427 # if NETINET
 428                           case AF_INET:
 429                                 addr.sin.sin_port = port;
 430                                 break;
 431 # endif /* NETINET */
 432 # if NETINET6
 433                           case AF_INET6:
 434                                 addr.sin6.sin6_port = port;
 435                                 break;
 436 # endif /* NETINET6 */
 437                         }
 438                 }
 439         }
 440 #endif /* NETINET || NETINET6 */
 441
 442         sock = socket(addr.sa.sa_family, SOCK_STREAM, 0);
 443         if (!ValidSocket(sock))
 444         {
 445                 smi_log(SMI_LOG_ERR,
 446                         "%s: Unable to create new socket: %s",
 447                         name, sm_errstring(errno));
 448                 return INVALID_SOCKET;
 449         }
 450
 451         if ((fdflags = fcntl(sock, F_GETFD, 0)) == -1 ||
 452             fcntl(sock, F_SETFD, fdflags | FD_CLOEXEC) == -1)
 453         {
 454                 smi_log(SMI_LOG_ERR,
 455                         "%s: Unable to set close-on-exec: %s", name,
 456                         sm_errstring(errno));
 457                 (void) closesocket(sock);
 458                 return INVALID_SOCKET;
 459         }
 460
 461         if (
 462 #if NETUNIX
 463             addr.sa.sa_family != AF_UNIX &&
 464 #endif /* NETUNIX */
 465             setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *) &sockopt,
 466                        sizeof(sockopt)) == -1)
 467         {
 468                 smi_log(SMI_LOG_ERR,
 469                         "%s: set reuseaddr failed (%s)", name,
 470                         sm_errstring(errno));
 471                 (void) closesocket(sock);
 472                 return INVALID_SOCKET;
 473         }
 474
 475 #if NETUNIX
 476         if (addr.sa.sa_family == AF_UNIX && rmsocket)
 477         {
 478                 struct stat s;
 479
 480                 if (stat(colon, &s) != 0)
 481                 {
 482                         if (errno != ENOENT)
 483                         {
 484                                 smi_log(SMI_LOG_ERR,
 485                                         "%s: Unable to stat() %s: %s",
 486                                         name, colon, sm_errstring(errno));
 487                                 (void) closesocket(sock);
 488                                 return INVALID_SOCKET;
 489                         }
 490                 }
 491                 else if (!S_ISSOCK(s.st_mode))
 492                 {
 493                         smi_log(SMI_LOG_ERR,
 494                                 "%s: %s is not a UNIX domain socket",
 495                                 name, colon);
 496                         (void) closesocket(sock);
 497                         return INVALID_SOCKET;
 498                 }
 499                 else if (unlink(colon) != 0)
 500                 {
 501                         smi_log(SMI_LOG_ERR,
 502                                 "%s: Unable to remove %s: %s",
 503                                 name, colon, sm_errstring(errno));
 504                         (void) closesocket(sock);
 505                         return INVALID_SOCKET;
 506                 }
 507         }
 508 #endif /* NETUNIX */
 509
 510         if (bind(sock, &addr.sa, L_socksize) < 0)
 511         {
 512                 smi_log(SMI_LOG_ERR,
 513                         "%s: Unable to bind to port %s: %s",
 514                         name, conn, sm_errstring(errno));
 515                 (void) closesocket(sock);
 516                 return INVALID_SOCKET;
 517         }
 518
 519         if (listen(sock, backlog) < 0)
 520         {
 521                 smi_log(SMI_LOG_ERR,
 522                         "%s: listen call failed: %s", name,
 523                         sm_errstring(errno));
 524                 (void) closesocket(sock);
 525                 return INVALID_SOCKET;
 526         }
 527
 528 #if NETUNIX
 529         if (addr.sa.sa_family == AF_UNIX && len > 0)
 530         {
 531                 /*
 532                 **  Set global variable sockpath so the UNIX socket can be
 533                 **  unlink()ed at exit.
 534                 */
 535
 536                 sockpath = (char *) malloc(len);
 537                 if (sockpath != NULL)
 538                         (void) sm_strlcpy(sockpath, colon, len);
 539                 else
 540                 {
 541                         smi_log(SMI_LOG_ERR,
 542                                 "%s: can't malloc(%d) for sockpath: %s",
 543                                 name, (int) len, sm_errstring(errno));
 544                         (void) closesocket(sock);
 545                         return INVALID_SOCKET;
 546                 }
 547         }
 548 #endif /* NETUNIX */
 549         L_family = addr.sa.sa_family;
 550         return sock;
 551 }
 552 /*
 553 **  MI_THREAD_HANDLE_WRAPPER -- small wrapper to handle session
 554 **
 555 **      Parameters:
 556 **              arg -- argument to pass to mi_handle_session()
 557 **
 558 **      Returns:
 559 **              results from mi_handle_session()
 560 */
 561
 562 static void *
 563 mi_thread_handle_wrapper(arg)
 564         void *arg;
 565 {
 566         return (void *) mi_handle_session(arg);
 567 }
 568
 569 /*
 570 **  MI_CLOSENER -- close listen socket
 571 **
 572 **      Parameters:
 573 **              none.
 574 **
 575 **      Returns:
 576 **              none.
 577 */
 578
 579 void
 580 mi_closener()
 581 {
 582         (void) smutex_lock(&L_Mutex);
 583         if (ValidSocket(listenfd))
 584         {
 585 #if NETUNIX
 586                 bool removable;
 587                 struct stat sockinfo;
 588                 struct stat fileinfo;
 589
 590                 removable = sockpath != NULL &&
 591                             geteuid() != 0 &&
 592                             fstat(listenfd, &sockinfo) == 0 &&
 593                             (S_ISFIFO(sockinfo.st_mode)
 594 # ifdef S_ISSOCK
 595                              || S_ISSOCK(sockinfo.st_mode)
 596 # endif /* S_ISSOCK */
 597                             );
 598 #endif /* NETUNIX */
 599
 600                 (void) closesocket(listenfd);
 601                 listenfd = INVALID_SOCKET;
 602
 603 #if NETUNIX
 604                 /* XXX sleep() some time before doing this? */
 605                 if (sockpath != NULL)
 606                 {
 607                         if (removable &&
 608                             stat(sockpath, &fileinfo) == 0 &&
 609                             ((fileinfo.st_dev == sockinfo.st_dev &&
 610                               fileinfo.st_ino == sockinfo.st_ino)
 611 # ifdef S_ISSOCK
 612                              || S_ISSOCK(fileinfo.st_mode)
 613 # endif /* S_ISSOCK */
 614                             )
 615                             &&
 616                             (S_ISFIFO(fileinfo.st_mode)
 617 # ifdef S_ISSOCK
 618                              || S_ISSOCK(fileinfo.st_mode)
 619 # endif /* S_ISSOCK */
 620                              ))
 621                                 (void) unlink(sockpath);
 622                         free(sockpath);
 623                         sockpath = NULL;
 624                 }
 625 #endif /* NETUNIX */
 626         }
 627         (void) smutex_unlock(&L_Mutex);
 628 }
 629
 630 /*
 631 **  MI_LISTENER -- Generic listener harness
 632 **
 633 **      Open up listen port
 634 **      Wait for connections
 635 **
 636 **      Parameters:
 637 **              conn -- connection description
 638 **              dbg -- debug level
 639 **              smfi -- filter structure to use
 640 **              timeout -- timeout for reads/writes
 641 **              backlog -- listen queue backlog size
 642 **
 643 **      Returns:
 644 **              MI_SUCCESS -- Exited normally
 645 **                         (session finished or we were told to exit)
 646 **              MI_FAILURE -- Network initialization failed.
 647 */
 648
 649 #if BROKEN_PTHREAD_SLEEP
 650
 651 /*
 652 **  Solaris 2.6, perhaps others, gets an internal threads library panic
 653 **  when sleep() is used:
 654 **
 655 **  thread_create() failed, returned 11 (EINVAL)
 656 **  co_enable, thr_create() returned error = 24
 657 **  libthread panic: co_enable failed (PID: 17793 LWP 1)
 658 **  stacktrace:
 659 **      ef526b10
 660 **      ef52646c
 661 **      ef534cbc
 662 **      156a4
 663 **      14644
 664 **      1413c
 665 **      135e0
 666 **      0
 667 */
 668
 669 # define MI_SLEEP(s)                                                    \
 670 {                                                                       \
 671         int rs = 0;                                                     \
 672         struct timeval st;                                              \
 673                                                                         \
 674         st.tv_sec = (s);                                                \
 675         st.tv_usec = 0;                                                 \
 676         if (st.tv_sec > 0)                                              \
 677         {                                                               \
 678                 for (;;)                                                \
 679                 {                                                       \
 680                         rs = select(0, NULL, NULL, NULL, &st);          \
 681                         if (rs < 0 && errno == EINTR)                   \
 682                                 continue;                               \
 683                         if (rs != 0)                                    \
 684                         {                                               \
 685                                 smi_log(SMI_LOG_ERR,                    \
 686                                         "MI_SLEEP(): select() returned non-zero result %d, errno = %d", \
 687                                         rs, errno);                     \
 688                         }                                               \
 689                         break;                                          \
 690                 }                                                       \
 691         }                                                               \
 692 }
 693 #else /* BROKEN_PTHREAD_SLEEP */
 694 # define MI_SLEEP(s)    sleep((s))
 695 #endif /* BROKEN_PTHREAD_SLEEP */
 696
 697 int
 698 mi_listener(conn, dbg, smfi, timeout, backlog)
 699         char *conn;
 700         int dbg;
 701         smfiDesc_ptr smfi;
 702         time_t timeout;
 703         int backlog;
 704 {
 705         socket_t connfd = INVALID_SOCKET;
 706 #if _FFR_DUP_FD
 707         socket_t dupfd = INVALID_SOCKET;
 708 #endif /* _FFR_DUP_FD */
 709         int sockopt = 1;
 710         int r, mistop;
 711         int ret = MI_SUCCESS;
 712         int mcnt = 0;   /* error count for malloc() failures */
 713         int tcnt = 0;   /* error count for thread_create() failures */
 714         int acnt = 0;   /* error count for accept() failures */
 715         int scnt = 0;   /* error count for select() failures */
 716         int save_errno = 0;
 717         sthread_t thread_id;
 718         _SOCK_ADDR cliaddr;
 719         SOCKADDR_LEN_T clilen;
 720         SMFICTX_PTR ctx;
 721         FD_RD_VAR(rds, excs);
 722         struct timeval chktime;
 723
 724         if (mi_opensocket(conn, backlog, dbg, false, smfi) == MI_FAILURE)
 725                 return MI_FAILURE;
 726
 727         clilen = L_socksize;
 728         while ((mistop = mi_stop()) == MILTER_CONT)
 729         {
 730                 (void) smutex_lock(&L_Mutex);
 731                 if (!ValidSocket(listenfd))
 732                 {
 733                         ret = MI_FAILURE;
 734                         smi_log(SMI_LOG_ERR,
 735                                 "%s: listenfd=%d corrupted, terminating, errno=%d",
 736                                 smfi->xxfi_name, listenfd, errno);
 737                         (void) smutex_unlock(&L_Mutex);
 738                         break;
 739                 }
 740
 741                 /* select on interface ports */
 742                 FD_RD_INIT(listenfd, rds, excs);
 743                 chktime.tv_sec = MI_CHK_TIME;
 744                 chktime.tv_usec = 0;
 745                 r = FD_RD_READY(listenfd, rds, excs, &chktime);
 746                 if (r == 0)             /* timeout */
 747                 {
 748                         (void) smutex_unlock(&L_Mutex);
 749                         continue;       /* just check mi_stop() */
 750                 }
 751                 if (r < 0)
 752                 {
 753                         save_errno = errno;
 754                         (void) smutex_unlock(&L_Mutex);
 755                         if (save_errno == EINTR)
 756                                 continue;
 757                         scnt++;
 758                         smi_log(SMI_LOG_ERR,
 759                                 "%s: select() failed (%s), %s",
 760                                 smfi->xxfi_name, sm_errstring(save_errno),
 761                                 scnt >= MAX_FAILS_S ? "abort" : "try again");
 762                         MI_SLEEP(scnt);
 763                         if (scnt >= MAX_FAILS_S)
 764                         {
 765                                 ret = MI_FAILURE;
 766                                 break;
 767                         }
 768                         continue;
 769                 }
 770                 if (!FD_IS_RD_RDY(listenfd, rds, excs))
 771                 {
 772                         /* some error: just stop for now... */
 773                         ret = MI_FAILURE;
 774                         (void) smutex_unlock(&L_Mutex);
 775                         smi_log(SMI_LOG_ERR,
 776                                 "%s: %s() returned exception for socket, abort",
 777                                 smfi->xxfi_name, MI_POLLSELECT);
 778                         break;
 779                 }
 780                 scnt = 0;       /* reset error counter for select() */
 781
 782                 (void) memset(&cliaddr, '\0', sizeof cliaddr);
 783                 connfd = accept(listenfd, (struct sockaddr *) &cliaddr,
 784                                 &clilen);
 785                 save_errno = errno;
 786                 (void) smutex_unlock(&L_Mutex);
 787
 788                 /*
 789                 **  If remote side closes before
 790                 **  accept() finishes, sockaddr
 791                 **  might not be fully filled in.
 792                 */
 793
 794                 if (ValidSocket(connfd) &&
 795                     (clilen == 0 ||
 796 # ifdef BSD4_4_SOCKADDR
 797                      cliaddr.sa.sa_len == 0 ||
 798 # endif /* BSD4_4_SOCKADDR */
 799                      cliaddr.sa.sa_family != L_family))
 800                 {
 801                         (void) closesocket(connfd);
 802                         connfd = INVALID_SOCKET;
 803                         save_errno = EINVAL;
 804                 }
 805
 806 #if !SM_CONF_POLL
 807                 /* check if acceptable for select() */
 808                 if (ValidSocket(connfd) && !SM_FD_OK_SELECT(connfd))
 809                 {
 810                         (void) closesocket(connfd);
 811                         connfd = INVALID_SOCKET;
 812                         save_errno = ERANGE;
 813                 }
 814 #endif /* !SM_CONF_POLL */
 815
 816                 if (!ValidSocket(connfd))
 817                 {
 818                         if (save_errno == EINTR
 819 #ifdef EAGAIN
 820                             || save_errno == EAGAIN
 821 #endif /* EAGAIN */
 822 #ifdef ECONNABORTED
 823                             || save_errno == ECONNABORTED
 824 #endif /* ECONNABORTED */
 825 #ifdef EMFILE
 826                             || save_errno == EMFILE
 827 #endif /* EMFILE */
 828 #ifdef ENFILE
 829                             || save_errno == ENFILE
 830 #endif /* ENFILE */
 831 #ifdef ENOBUFS
 832                             || save_errno == ENOBUFS
 833 #endif /* ENOBUFS */
 834 #ifdef ENOMEM
 835                             || save_errno == ENOMEM
 836 #endif /* ENOMEM */
 837 #ifdef ENOSR
 838                             || save_errno == ENOSR
 839 #endif /* ENOSR */
 840 #ifdef EWOULDBLOCK
 841                             || save_errno == EWOULDBLOCK
 842 #endif /* EWOULDBLOCK */
 843                            )
 844                                 continue;
 845                         acnt++;
 846                         smi_log(SMI_LOG_ERR,
 847                                 "%s: accept() returned invalid socket (%s), %s",
 848                                 smfi->xxfi_name, sm_errstring(save_errno),
 849                                 acnt >= MAX_FAILS_A ? "abort" : "try again");
 850                         MI_SLEEP(acnt);
 851                         if (acnt >= MAX_FAILS_A)
 852                         {
 853                                 ret = MI_FAILURE;
 854                                 break;
 855                         }
 856                         continue;
 857                 }
 858                 acnt = 0;       /* reset error counter for accept() */
 859 #if _FFR_DUP_FD
 860                 dupfd = fcntl(connfd, F_DUPFD, 256);
 861                 if (ValidSocket(dupfd)
 862 # if !SM_CONF_POLL
 863                     && SM_FD_OK_SELECT(dupfd)
 864 # endif /* !SM_CONF_POLL */
 865                    )
 866                 {
 867                         close(connfd);
 868                         connfd = dupfd;
 869                         dupfd = INVALID_SOCKET;
 870                 }
 871 #endif /* _FFR_DUP_FD */
 872
 873                 if (setsockopt(connfd, SOL_SOCKET, SO_KEEPALIVE,
 874                                 (void *) &sockopt, sizeof sockopt) < 0)
 875                 {
 876                         smi_log(SMI_LOG_WARN,
 877                                 "%s: set keepalive failed (%s)",
 878                                 smfi->xxfi_name, sm_errstring(errno));
 879                         /* XXX: continue? */
 880                 }
 881                 if ((ctx = (SMFICTX_PTR) malloc(sizeof *ctx)) == NULL)
 882                 {
 883                         (void) closesocket(connfd);
 884                         mcnt++;
 885                         smi_log(SMI_LOG_ERR, "%s: malloc(ctx) failed (%s), %s",
 886                                 smfi->xxfi_name, sm_errstring(save_errno),
 887                                 mcnt >= MAX_FAILS_M ? "abort" : "try again");
 888                         MI_SLEEP(mcnt);
 889                         if (mcnt >= MAX_FAILS_M)
 890                         {
 891                                 ret = MI_FAILURE;
 892                                 break;
 893                         }
 894                         continue;
 895                 }
 896                 mcnt = 0;       /* reset error counter for malloc() */
 897                 (void) memset(ctx, '\0', sizeof *ctx);
 898                 ctx->ctx_sd = connfd;
 899                 ctx->ctx_dbg = dbg;
 900                 ctx->ctx_timeout = timeout;
 901                 ctx->ctx_smfi = smfi;
 902 #if 0
 903                 if (smfi->xxfi_eoh == NULL)
 904                 if (smfi->xxfi_eom == NULL)
 905                 if (smfi->xxfi_abort == NULL)
 906                 if (smfi->xxfi_close == NULL)
 907 #endif /* 0 */
 908                 if (smfi->xxfi_connect == NULL)
 909                         ctx->ctx_pflags |= SMFIP_NOCONNECT;
 910                 if (smfi->xxfi_helo == NULL)
 911                         ctx->ctx_pflags |= SMFIP_NOHELO;
 912                 if (smfi->xxfi_envfrom == NULL)
 913                         ctx->ctx_pflags |= SMFIP_NOMAIL;
 914                 if (smfi->xxfi_envrcpt == NULL)
 915                         ctx->ctx_pflags |= SMFIP_NORCPT;
 916                 if (smfi->xxfi_header == NULL)
 917                         ctx->ctx_pflags |= SMFIP_NOHDRS;
 918                 if (smfi->xxfi_eoh == NULL)
 919                         ctx->ctx_pflags |= SMFIP_NOEOH;
 920                 if (smfi->xxfi_body == NULL)
 921                         ctx->ctx_pflags |= SMFIP_NOBODY;
 922
 923                 if ((r = thread_create(&thread_id,
 924                                         mi_thread_handle_wrapper,
 925                                         (void *) ctx)) != 0)
 926                 {
 927                         tcnt++;
 928                         smi_log(SMI_LOG_ERR,
 929                                 "%s: thread_create() failed: %d, %s",
 930                                 smfi->xxfi_name,  r,
 931                                 tcnt >= MAX_FAILS_T ? "abort" : "try again");
 932                         MI_SLEEP(tcnt);
 933                         (void) closesocket(connfd);
 934                         free(ctx);
 935                         if (tcnt >= MAX_FAILS_T)
 936                         {
 937                                 ret = MI_FAILURE;
 938                                 break;
 939                         }
 940                         continue;
 941                 }
 942                 tcnt = 0;
 943         }
 944         if (ret != MI_SUCCESS)
 945                 mi_stop_milters(MILTER_ABRT);
 946         else
 947         {
 948                 if (mistop != MILTER_CONT)
 949                         smi_log(SMI_LOG_INFO, "%s: mi_stop=%d",
 950                                 smfi->xxfi_name, mistop);
 951                 mi_closener();
 952         }
 953         (void) smutex_destroy(&L_Mutex);
 954         return ret;
 955 }