io.c

   1 /*
   2 Copyright (c) 2003-2006 by Juliusz Chroboczek
   3
   4 Permission is hereby granted, free of charge, to any person obtaining a copy
   5 of this software and associated documentation files (the "Software"), to deal
   6 in the Software without restriction, including without limitation the rights
   7 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8 copies of the Software, and to permit persons to whom the Software is
   9 furnished to do so, subject to the following conditions:
  10
  11 The above copyright notice and this permission notice shall be included in
  12 all copies or substantial portions of the Software.
  13
  14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  17 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  20 THE SOFTWARE.
  21 */
  22
  23 #include "polipo.h"
  24
  25 #ifdef HAVE_IPv6
  26 #ifdef IPV6_PREFER_TEMPADDR
  27 #define HAVE_IPV6_PREFER_TEMPADDR 1
  28 #endif
  29 #endif
  30
  31 #ifdef HAVE_IPV6_PREFER_TEMPADDR
  32 int useTemporarySourceAddress = 1;
  33 #endif
  34
  35 void
  36 preinitIo()
  37 {
  38 #ifdef HAVE_IPV6_PREFER_TEMPADDR
  39     CONFIG_VARIABLE_SETTABLE(useTemporarySourceAddress, CONFIG_TRISTATE,
  40                              configIntSetter,
  41                              "Prefer IPv6 temporary source address.");
  42 #endif
  43
  44 #ifdef HAVE_WINSOCK
  45     /* Load the winsock dll */
  46     WSADATA wsaData;
  47     WORD wVersionRequested = MAKEWORD(2, 2);
  48     int err = WSAStartup( wVersionRequested, &wsaData );
  49     if (err != 0) {
  50         do_log_error(L_ERROR, err, "Couldn't load winsock dll");
  51         exit(-1);
  52     }
  53 #endif
  54     return;
  55 }
  56
  57 void
  58 initIo()
  59 {
  60     return;
  61 }
  62
  63 FdEventHandlerPtr
  64 do_stream(int operation, int fd, int offset, char *buf, int len,
  65           int (*handler)(int, FdEventHandlerPtr, StreamRequestPtr),
  66           void *data)
  67 {
  68     assert(len > offset || (operation & (IO_END | IO_IMMEDIATE)));
  69     return schedule_stream(operation, fd, offset,
  70                            NULL, 0, buf, len, NULL, 0, NULL, 0, NULL,
  71                            handler, data);
  72 }
  73
  74 FdEventHandlerPtr
  75 do_stream_2(int operation, int fd, int offset,
  76             char *buf, int len, char *buf2, int len2,
  77             int (*handler)(int, FdEventHandlerPtr, StreamRequestPtr),
  78             void *data)
  79 {
  80     assert(len + len2 > offset || (operation & (IO_END | IO_IMMEDIATE)));
  81     return schedule_stream(operation, fd, offset,
  82                            NULL, 0, buf, len, buf2, len2, NULL, 0, NULL,
  83                            handler, data);
  84 }
  85
  86 FdEventHandlerPtr
  87 do_stream_3(int operation, int fd, int offset,
  88             char *buf, int len, char *buf2, int len2, char *buf3, int len3,
  89             int (*handler)(int, FdEventHandlerPtr, StreamRequestPtr),
  90             void *data)
  91 {
  92     assert(len + len2 > offset || (operation & (IO_END | IO_IMMEDIATE)));
  93     return schedule_stream(operation, fd, offset,
  94                            NULL, 0, buf, len, buf2, len2, buf3, len3, NULL,
  95                            handler, data);
  96 }
  97
  98 FdEventHandlerPtr
  99 do_stream_h(int operation, int fd, int offset,
 100             char *header, int hlen, char *buf, int len,
 101             int (*handler)(int, FdEventHandlerPtr, StreamRequestPtr),
 102             void *data)
 103 {
 104     assert(hlen + len > offset || (operation & (IO_END | IO_IMMEDIATE)));
 105     return schedule_stream(operation, fd, offset,
 106                            header, hlen, buf, len, NULL, 0, NULL, 0, NULL,
 107                            handler, data);
 108 }
 109
 110 FdEventHandlerPtr
 111 do_stream_buf(int operation, int fd, int offset, char **buf_location, int len,
 112               int (*handler)(int, FdEventHandlerPtr, StreamRequestPtr),
 113               void *data)
 114 {
 115     assert((len > offset || (operation & (IO_END | IO_IMMEDIATE)))
 116            && len <= CHUNK_SIZE);
 117     return schedule_stream(operation, fd, offset,
 118                            NULL, 0, *buf_location, len,
 119                            NULL, 0, NULL, 0, buf_location,
 120                            handler, data);
 121 }
 122
 123 static int
 124 chunkHeaderLen(int i)
 125 {
 126     if(i <= 0)
 127         return 0;
 128     if(i < 0x10)
 129         return 3;
 130     else if(i < 0x100)
 131         return 4;
 132     else if(i < 0x1000)
 133         return 5;
 134     else if(i < 0x10000)
 135         return 6;
 136     else
 137         abort();
 138 }
 139
 140 static int
 141 chunkHeader(char *buf, int buflen, int i)
 142 {
 143     int n;
 144     if(i <= 0)
 145         return 0;
 146     n = snprintf(buf, buflen, "%x\r\n", i);
 147     return n;
 148 }
 149
 150
 151 FdEventHandlerPtr
 152 schedule_stream(int operation, int fd, int offset,
 153                 char *header, int hlen,
 154                 char *buf, int len, char *buf2, int len2, char *buf3, int len3,
 155                 char **buf_location,
 156                 int (*handler)(int, FdEventHandlerPtr, StreamRequestPtr),
 157                 void *data)
 158 {
 159     StreamRequestRec request;
 160     FdEventHandlerPtr event;
 161     int done;
 162
 163     request.operation = operation;
 164     request.fd = fd;
 165     if(len3) {
 166         assert(hlen == 0 && buf_location == NULL);
 167         request.u.b.len3 = len3;
 168         request.u.b.buf3 = buf3;
 169         request.operation |= IO_BUF3;
 170     } else if(buf_location) {
 171         assert(hlen == 0);
 172         request.u.l.buf_location = buf_location;
 173         request.operation |= IO_BUF_LOCATION;
 174     } else {
 175         request.u.h.hlen = hlen;
 176         request.u.h.header = header;
 177     }
 178     request.buf = buf;
 179     request.len = len;
 180     request.buf2 = buf2;
 181     request.len2 = len2;
 182     if((operation & IO_CHUNKED) ||
 183        (!(request.operation & (IO_BUF3 | IO_BUF_LOCATION)) && hlen > 0)) {
 184         assert(offset == 0);
 185         request.offset = -hlen;
 186         if(operation & IO_CHUNKED)
 187             request.offset += -chunkHeaderLen(len + len2);
 188     } else {
 189         request.offset = offset;
 190     }
 191     request.handler = handler;
 192     request.data = data;
 193     event = makeFdEvent(fd,
 194                         (operation & IO_MASK) == IO_WRITE ?
 195                         POLLOUT : POLLIN,
 196                         do_scheduled_stream,
 197                         sizeof(StreamRequestRec), &request);
 198     if(!event) {
 199         done = (*handler)(-ENOMEM, NULL, &request);
 200         assert(done);
 201         return NULL;
 202     }
 203
 204     if(!(operation & IO_NOTNOW)) {
 205         done = event->handler(0, event);
 206         if(done) {
 207             free(event);
 208             return NULL;
 209         }
 210     }
 211
 212     if(operation & IO_IMMEDIATE) {
 213         assert(hlen == 0 && !(operation & IO_CHUNKED));
 214         done = (*handler)(0, event, &request);
 215         if(done) {
 216             free(event);
 217             return NULL;
 218         }
 219     }
 220     event = registerFdEventHelper(event);
 221     return event;
 222 }
 223
 224 static const char *endChunkTrailer = "\r\n0\r\n\r\n";
 225
 226 int
 227 do_scheduled_stream(int status, FdEventHandlerPtr event)
 228 {
 229     StreamRequestPtr request = (StreamRequestPtr)&event->data;
 230     int rc, done, i;
 231     struct iovec iov[6];
 232     int chunk_header_len, chunk_trailer_len;
 233     char chunk_header[10];
 234     int len12 = request->len + request->len2;
 235     int len123 =
 236         request->len + request->len2 +
 237         ((request->operation & IO_BUF3) ? request->u.b.len3 : 0);
 238
 239     if(status) {
 240         done = request->handler(status, event, request);
 241         return done;
 242     }
 243
 244     i = 0;
 245
 246     if(request->offset < 0) {
 247         assert((request->operation & (IO_MASK | IO_BUF3 | IO_BUF_LOCATION)) ==
 248                IO_WRITE);
 249         if(request->operation & IO_CHUNKED) {
 250             chunk_header_len = chunkHeaderLen(len123);
 251             chunk_trailer_len = 2;
 252         } else {
 253             chunk_header_len = 0;
 254             chunk_trailer_len = 0;
 255         }
 256
 257         if(request->offset < -chunk_header_len) {
 258             assert(request->offset >= -(request->u.h.hlen + chunk_header_len));
 259             iov[i].iov_base = request->u.h.header;
 260             iov[i].iov_len = -request->offset - chunk_header_len;
 261             i++;
 262         }
 263
 264         if(chunk_header_len > 0) {
 265             chunkHeader(chunk_header, 10, len123);
 266             if(request->offset < -chunk_header_len) {
 267                 iov[i].iov_base = chunk_header;
 268                 iov[i].iov_len = chunk_header_len;
 269             } else {
 270                 iov[i].iov_base = chunk_header +
 271                     chunk_header_len + request->offset;
 272                 iov[i].iov_len = -request->offset;
 273             }
 274             i++;
 275         }
 276     }
 277
 278     if(request->len > 0) {
 279         if(request->buf == NULL &&
 280            (request->operation & IO_BUF_LOCATION)) {
 281             assert(*request->u.l.buf_location == NULL);
 282             request->buf = *request->u.l.buf_location = get_chunk();
 283             if(request->buf == NULL) {
 284                 done = request->handler(-ENOMEM, event, request);
 285                 return done;
 286             }
 287         }
 288         if(request->offset <= 0) {
 289             iov[i].iov_base = request->buf;
 290             iov[i].iov_len = request->len;
 291             i++;
 292         } else if(request->offset < request->len) {
 293             iov[i].iov_base = request->buf + request->offset;
 294             iov[i].iov_len = request->len - request->offset;
 295             i++;
 296         }
 297     }
 298
 299     if(request->len2 > 0) {
 300         if(request->offset <= request->len) {
 301             iov[i].iov_base = request->buf2;
 302             iov[i].iov_len = request->len2;
 303             i++;
 304         } else if(request->offset < request->len + request->len2) {
 305             iov[i].iov_base = request->buf2 + request->offset - request->len;
 306             iov[i].iov_len = request->len2 - request->offset + request->len;
 307             i++;
 308         }
 309     }
 310
 311     if((request->operation & IO_BUF3) && request->u.b.len3 > 0) {
 312         if(request->offset <= len12) {
 313             iov[i].iov_base = request->u.b.buf3;
 314             iov[i].iov_len = request->u.b.len3;
 315             i++;
 316         } else if(request->offset < len12 + request->u.b.len3) {
 317             iov[i].iov_base = request->u.b.buf3 + request->offset - len12;
 318             iov[i].iov_len = request->u.b.len3 - request->offset + len12;
 319             i++;
 320         }
 321     }
 322
 323     if((request->operation & IO_CHUNKED)) {
 324         int l;
 325         const char *trailer;
 326         if(request->operation & IO_END) {
 327             if(len123 == 0) {
 328                 trailer = endChunkTrailer + 2;
 329                 l = 5;
 330             } else {
 331                 trailer = endChunkTrailer;
 332                 l = 7;
 333             }
 334         } else {
 335             trailer = endChunkTrailer;
 336             l = 2;
 337         }
 338
 339         if(request->offset <= len123) {
 340             iov[i].iov_base = (char*)trailer;
 341             iov[i].iov_len = l;
 342             i++;
 343         } else if(request->offset < len123 + l) {
 344             iov[i].iov_base =
 345                 (char*)endChunkTrailer + request->offset - len123;
 346             iov[i].iov_len = l - request->offset + len123;
 347             i++;
 348         }
 349     }
 350
 351     assert(i > 0);
 352
 353     if((request->operation & IO_MASK) == IO_WRITE) {
 354         if(i > 1)
 355             rc = WRITEV(request->fd, iov, i);
 356         else
 357             rc = WRITE(request->fd, iov[0].iov_base, iov[0].iov_len);
 358     } else {
 359         if(i > 1)
 360             rc = READV(request->fd, iov, i);
 361         else
 362             rc = READ(request->fd, iov[0].iov_base, iov[0].iov_len);
 363     }
 364
 365     if(rc > 0) {
 366         request->offset += rc;
 367         if(request->offset < 0) return 0;
 368         done = request->handler(0, event, request);
 369         return done;
 370     } else if(rc == 0 || errno == EPIPE) {
 371         done = request->handler(1, event, request);
 372     } else if(errno == EAGAIN || errno == EINTR) {
 373         return 0;
 374     } else if(errno == EFAULT || errno == EBADF) {
 375         abort();
 376     } else {
 377         done = request->handler(-errno, event, request);
 378     }
 379     assert(done);
 380     return done;
 381 }
 382
 383 int
 384 streamRequestDone(StreamRequestPtr request)
 385 {
 386     int len123 =
 387         request->len + request->len2 +
 388         ((request->operation & IO_BUF3) ? request->u.b.len3 : 0);
 389
 390     if(request->offset < 0)
 391         return 0;
 392     else if(request->offset < len123)
 393         return 0;
 394     else if(request->operation & IO_CHUNKED) {
 395         if(request->operation & IO_END) {
 396             if(request->offset < len123 + (len123 ? 7 : 5))
 397                 return 0;
 398         } else {
 399             if(request->offset < len123 + 2)
 400                 return 0;
 401         }
 402     }
 403
 404     return 1;
 405 }
 406
 407 static int
 408 serverSocket(int af)
 409 {
 410     int fd, rc;
 411     if(af == 4) {
 412         fd = socket(PF_INET, SOCK_STREAM, 0);
 413     } else if(af == 6) {
 414 #ifdef HAVE_IPv6
 415         fd = socket(PF_INET6, SOCK_STREAM, 0);
 416 #else
 417         fd = -1;
 418         errno = EAFNOSUPPORT;
 419 #endif
 420     } else {
 421         abort();
 422     }
 423
 424     if(fd >= 0) {
 425         rc = setNonblocking(fd, 1);
 426         if(rc < 0) {
 427             int errno_save = errno;
 428             CLOSE(fd);
 429             errno = errno_save;
 430             return -1;
 431         }
 432 #ifdef HAVE_IPV6_PREFER_TEMPADDR
 433         if (af == 6 && useTemporarySourceAddress != 1) {
 434             int value;
 435             value = (useTemporarySourceAddress == 2) ? 1 : 0;
 436             rc = setsockopt(fd, IPPROTO_IPV6, IPV6_PREFER_TEMPADDR,
 437                             &value, sizeof(value));
 438             if (rc < 0) {
 439                 /* no error, warning only */
 440                 do_log_error(L_WARN, errno, "Couldn't set IPV6CTL_USETEMPADDR");
 441             }
 442         }
 443
 444 #endif
 445     }
 446     return fd;
 447 }
 448
 449 FdEventHandlerPtr
 450 do_connect(AtomPtr addr, int index, int port,
 451            int (*handler)(int, FdEventHandlerPtr, ConnectRequestPtr),
 452            void *data)
 453 {
 454     ConnectRequestRec request;
 455     FdEventHandlerPtr event;
 456     int done, fd, af;
 457
 458     assert(addr->length > 0 && addr->string[0] == DNS_A);
 459     assert(addr->length % sizeof(HostAddressRec) == 1);
 460
 461     if(index >= (addr->length - 1)/ sizeof(HostAddressRec))
 462         index = 0;
 463
 464     request.firstindex = index;
 465     request.port = port;
 466     request.handler = handler;
 467     request.data = data;
 468  again:
 469     af = addr->string[1 + index * sizeof(HostAddressRec)];
 470     fd = serverSocket(af);
 471
 472     request.fd = fd;
 473     request.af = af;
 474     request.addr = addr;
 475     request.index = index;
 476
 477     if(fd < 0) {
 478         int n = (addr->length - 1) / sizeof(HostAddressRec);
 479         if(errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT) {
 480             if((index + 1) % n != request.firstindex) {
 481                 index = (index + 1) % n;
 482                 goto again;
 483             }
 484         }
 485         do_log_error(L_ERROR, errno, "Couldn't create socket");
 486         done = (*handler)(-errno, NULL, &request);
 487         assert(done);
 488         return NULL;
 489     }
 490
 491     /* POLLIN is apparently needed on Windows */
 492     event = registerFdEvent(fd, POLLIN | POLLOUT,
 493                             do_scheduled_connect,
 494                             sizeof(ConnectRequestRec), &request);
 495     if(event == NULL) {
 496         done = (*handler)(-ENOMEM, NULL, &request);
 497         assert(done);
 498         return NULL;
 499     }
 500
 501     done = event->handler(0, event);
 502     if(done) {
 503         unregisterFdEvent(event);
 504         return NULL;
 505     }
 506     return event;
 507 }
 508
 509 int
 510 do_scheduled_connect(int status, FdEventHandlerPtr event)
 511 {
 512     ConnectRequestPtr request = (ConnectRequestPtr)&event->data;
 513     AtomPtr addr = request->addr;
 514     int done;
 515     int rc;
 516     HostAddressPtr host;
 517     struct sockaddr_in servaddr;
 518 #ifdef HAVE_IPv6
 519     struct sockaddr_in6 servaddr6;
 520 #endif
 521
 522     assert(addr->length > 0 && addr->string[0] == DNS_A);
 523     assert(addr->length % sizeof(HostAddressRec) == 1);
 524     assert(request->index < (addr->length - 1) / sizeof(HostAddressRec));
 525
 526     if(status) {
 527         done = request->handler(status, event, request);
 528         if(done) {
 529             releaseAtom(addr);
 530             request->addr = NULL;
 531             return 1;
 532         }
 533         return 0;
 534     }
 535
 536  again:
 537     host = (HostAddressPtr)&addr->string[1 +
 538                                          request->index *
 539                                          sizeof(HostAddressRec)];
 540     if(host->af != request->af) {
 541         int newfd;
 542         /* Ouch.  Our socket has a different protocol than the host
 543            address. */
 544         CLOSE(request->fd);
 545         newfd = serverSocket(host->af);
 546         if(newfd < 0) {
 547             if(errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT) {
 548                 int n = request->addr->length / sizeof(HostAddressRec);
 549                 if((request->index + 1) % n != request->firstindex) {
 550                     request->index = (request->index + 1) % n;
 551                     goto again;
 552                 }
 553             }
 554             request->fd = -1;
 555             done = request->handler(-errno, event, request);
 556             assert(done);
 557             return 1;
 558         }
 559         if(newfd != request->fd) {
 560             request->fd = dup2(newfd, request->fd);
 561             CLOSE(newfd);
 562             if(request->fd < 0) {
 563                 done = request->handler(-errno, event, request);
 564                 assert(done);
 565                 return 1;
 566             }
 567         }
 568         request->af = host->af;
 569     }
 570     switch(host->af) {
 571     case 4:
 572         memset(&servaddr, 0, sizeof(servaddr));
 573         servaddr.sin_family = AF_INET;
 574         servaddr.sin_port = htons(request->port);
 575         memcpy(&servaddr.sin_addr, &host->data, sizeof(struct in_addr));
 576         rc = connect(request->fd,
 577                      (struct sockaddr*)&servaddr, sizeof(servaddr));
 578         break;
 579     case 6:
 580 #ifdef HAVE_IPv6
 581         memset(&servaddr6, 0, sizeof(servaddr6));
 582         servaddr6.sin6_family = AF_INET6;
 583         servaddr6.sin6_port = htons(request->port);
 584         memcpy(&servaddr6.sin6_addr, &host->data, sizeof(struct in6_addr));
 585         rc = connect(request->fd,
 586                      (struct sockaddr*)&servaddr6, sizeof(servaddr6));
 587 #else
 588         rc = -1;
 589         errno = EAFNOSUPPORT;
 590 #endif
 591         break;
 592     default:
 593         abort();
 594     }
 595
 596     if(rc >= 0 || errno == EISCONN) {
 597         done = request->handler(1, event, request);
 598         assert(done);
 599         releaseAtom(request->addr);
 600         request->addr = NULL;
 601         return 1;
 602     }
 603
 604     if(errno == EINPROGRESS || errno == EINTR) {
 605         return 0;
 606     } else if(errno == EFAULT || errno == EBADF) {
 607         abort();
 608     } else {
 609         int n = request->addr->length / sizeof(HostAddressRec);
 610         if((request->index + 1) % n != request->firstindex) {
 611             request->index = (request->index + 1) % n;
 612             goto again;
 613         }
 614         done = request->handler(-errno, event, request);
 615         assert(done);
 616         releaseAtom(request->addr);
 617         request->addr = NULL;
 618         return 1;
 619     }
 620 }
 621
 622 FdEventHandlerPtr
 623 do_accept(int fd,
 624           int (*handler)(int, FdEventHandlerPtr, AcceptRequestPtr),
 625           void *data)
 626 {
 627     FdEventHandlerPtr event;
 628     int done;
 629
 630     event = schedule_accept(fd, handler, data);
 631     if(event == NULL) {
 632         done = (*handler)(-ENOMEM, NULL, NULL);
 633         assert(done);
 634     }
 635
 636     /* But don't invoke it now - this will delay accept if under load. */
 637     return event;
 638 }
 639
 640 FdEventHandlerPtr
 641 schedule_accept(int fd,
 642                 int (*handler)(int, FdEventHandlerPtr, AcceptRequestPtr),
 643                 void *data)
 644 {
 645     FdEventHandlerPtr event;
 646     AcceptRequestRec request;
 647     int done;
 648
 649     request.fd = fd;
 650     request.handler = handler;
 651     request.data = data;
 652     event = registerFdEvent(fd, POLLOUT|POLLIN,
 653                             do_scheduled_accept, sizeof(request), &request);
 654     if(!event) {
 655         done = (*handler)(-ENOMEM, NULL, NULL);
 656         assert(done);
 657     }
 658     return event;
 659 }
 660
 661 int
 662 do_scheduled_accept(int status, FdEventHandlerPtr event)
 663 {
 664     AcceptRequestPtr request = (AcceptRequestPtr)&event->data;
 665     int rc, done;
 666     unsigned len;
 667     struct sockaddr_in addr;
 668
 669     if(status) {
 670         done = request->handler(status, event, request);
 671         if(done) return done;
 672     }
 673
 674     len = sizeof(struct sockaddr_in);
 675
 676     rc = accept(request->fd, (struct sockaddr*)&addr, &len);
 677
 678     if(rc >= 0)
 679         done = request->handler(rc, event, request);
 680     else
 681         done = request->handler(-errno, event, request);
 682     return done;
 683 }
 684
 685 FdEventHandlerPtr
 686 create_listener(char *address, int port,
 687                 int (*handler)(int, FdEventHandlerPtr, AcceptRequestPtr),
 688                 void *data)
 689 {
 690     int fd, rc;
 691     int one = 1;
 692     int done;
 693     struct sockaddr_in addr;
 694 #ifdef HAVE_IPv6
 695     int inet6 = 1;
 696     struct sockaddr_in6 addr6;
 697 #else
 698     int inet6 = 0;
 699 #endif
 700
 701     if(inet6 && address) {
 702         struct in_addr buf;
 703         rc = inet_aton(address, &buf);
 704         if(rc == 1)
 705             inet6 = 0;
 706     }
 707     fd = -1;
 708     errno = EAFNOSUPPORT;
 709
 710 #ifdef HAVE_IPv6
 711     if(inet6) {
 712         fd = socket(PF_INET6, SOCK_STREAM, 0);
 713     }
 714 #endif
 715
 716     if(fd < 0 && (errno == EPROTONOSUPPORT || errno == EAFNOSUPPORT)) {
 717         inet6 = 0;
 718         fd = socket(PF_INET, SOCK_STREAM, 0);
 719     }
 720
 721     if(fd < 0) {
 722         done = (*handler)(-errno, NULL, NULL);
 723         assert(done);
 724         return NULL;
 725     }
 726
 727     rc = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *)&one, sizeof(one));
 728     if(rc < 0) do_log_error(L_WARN, errno, "Couldn't set SO_REUSEADDR");
 729
 730     if(inet6) {
 731 #ifdef HAVE_IPv6
 732         rc = setV6only(fd, 0);
 733         if(rc < 0)
 734             /* Reportedly OpenBSD returns an error for that.  So only
 735                log it as a debugging message. */
 736             do_log_error(D_CLIENT_CONN, errno, "Couldn't reset IPV6_V6ONLY");
 737
 738         memset(&addr6, 0, sizeof(addr6));
 739         rc = inet_pton(AF_INET6, address, &addr6.sin6_addr);
 740         if(rc != 1) {
 741             done = (*handler)(rc == 0 ? -ESYNTAX : -errno, NULL, NULL);
 742             assert(done);
 743             return NULL;
 744         }
 745         addr6.sin6_family = AF_INET6;
 746         addr6.sin6_port = htons(port);
 747         rc = bind(fd, (struct sockaddr*)&addr6, sizeof(addr6));
 748 #else
 749         rc = -1;
 750         errno = EAFNOSUPPORT;
 751 #endif
 752     } else {
 753         memset(&addr, 0, sizeof(addr));
 754         rc = inet_aton(address, &addr.sin_addr);
 755         if(rc != 1) {
 756             done = (*handler)(rc == 0 ? -ESYNTAX : -errno, NULL, NULL);
 757             assert(done);
 758             return NULL;
 759         }
 760         addr.sin_family = AF_INET;
 761         addr.sin_port = htons(port);
 762         rc = bind(fd, (struct sockaddr*)&addr, sizeof(addr));
 763     }
 764
 765     if(rc < 0) {
 766         do_log_error(L_ERROR, errno, "Couldn't bind");
 767         CLOSE(fd);
 768         done = (*handler)(-errno, NULL, NULL);
 769         assert(done);
 770         return NULL;
 771     }
 772
 773     rc = setNonblocking(fd, 1);
 774     if(rc < 0) {
 775         do_log_error(L_ERROR, errno, "Couldn't set non blocking mode");
 776         CLOSE(fd);
 777         done = (*handler)(-errno, NULL, NULL);
 778         assert(done);
 779         return NULL;
 780     }
 781
 782     rc = listen(fd, 32);
 783     if(rc < 0) {
 784         do_log_error(L_ERROR, errno, "Couldn't listen");
 785         CLOSE(fd);
 786         done = (*handler)(-errno, NULL, NULL);
 787         assert(done);
 788         return NULL;
 789     }
 790
 791     do_log(L_INFO, "Established listening socket on port %d.\n", port);
 792
 793     return schedule_accept(fd, handler, data);
 794 }
 795
 796 #ifndef SOL_TCP
 797 /* BSD */
 798 #define SOL_TCP IPPROTO_TCP
 799 #endif
 800
 801 int
 802 setNonblocking(int fd, int nonblocking)
 803 {
 804 #ifdef MINGW
 805     return mingw_setnonblocking(fd, nonblocking);
 806 #else
 807     int rc;
 808     rc = fcntl(fd, F_GETFL, 0);
 809     if(rc < 0)
 810         return -1;
 811
 812     rc = fcntl(fd, F_SETFL, nonblocking?(rc | O_NONBLOCK):(rc & ~O_NONBLOCK));
 813     if(rc < 0)
 814         return -1;
 815
 816     return 0;
 817 #endif
 818 }
 819
 820 int
 821 setNodelay(int fd, int nodelay)
 822 {
 823     int val = nodelay ? 1 : 0;
 824     int rc;
 825     rc = setsockopt(fd, SOL_TCP, TCP_NODELAY, (char *)&val, sizeof(val));
 826     if(rc < 0)
 827         return -1;
 828     return 0;
 829 }
 830
 831 #ifdef IPV6_V6ONLY
 832 int
 833 setV6only(int fd, int v6only)
 834 {
 835     int val = v6only ? 1 : 0;
 836     int rc;
 837     rc = setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&val, sizeof(val));
 838     if(rc < 0)
 839         return -1;
 840     return 0;
 841 }
 842 #else
 843 int
 844 setV6only(int fd, int v6only)
 845 {
 846     return 0;
 847 }
 848 #endif
 849
 850 typedef struct _LingeringClose {
 851     int fd;
 852     FdEventHandlerPtr handler;
 853     TimeEventHandlerPtr timeout;
 854 } LingeringCloseRec, *LingeringClosePtr;
 855
 856 static int
 857 lingeringCloseTimeoutHandler(TimeEventHandlerPtr event)
 858 {
 859     LingeringClosePtr l = *(LingeringClosePtr*)event->data;
 860     assert(l->timeout == event);
 861     l->timeout = NULL;
 862     if(l->handler)
 863         pokeFdEvent(l->fd, -ESHUTDOWN, POLLIN | POLLOUT);
 864     else {
 865         CLOSE(l->fd);
 866         free(l);
 867     }
 868     return 1;
 869 }
 870
 871 static int
 872 lingeringCloseHandler(int status, FdEventHandlerPtr event)
 873 {
 874     LingeringClosePtr l = *(LingeringClosePtr*)event->data;
 875     char buf[17];
 876     int rc;
 877
 878     assert(l->handler == event);
 879
 880     l->handler = NULL;
 881     if(status && status != -EDOGRACEFUL)
 882         goto done;
 883
 884     rc = READ(l->fd, &buf, 17);
 885     if(rc == 0 || (rc < 0 && errno != EAGAIN && errno != EINTR))
 886         goto done;
 887
 888     /* The client is still sending data.  Ignore it in order to let
 889        TCP's flow control do its work.  The timeout will close the
 890        connection. */
 891     return 1;
 892
 893  done:
 894     if(l->timeout) {
 895         cancelTimeEvent(l->timeout);
 896         l->timeout = NULL;
 897     }
 898     CLOSE(l->fd);
 899     free(l);
 900     return 1;
 901 }
 902
 903 int
 904 lingeringClose(int fd)
 905 {
 906     int rc;
 907     LingeringClosePtr l;
 908
 909     rc = shutdown(fd, 1);
 910     if(rc < 0) {
 911         if(errno != ENOTCONN) {
 912             do_log_error(L_ERROR, errno, "Shutdown failed");
 913         } else if(errno == EFAULT || errno == EBADF) {
 914             abort();
 915         }
 916         CLOSE(fd);
 917         return 1;
 918     }
 919
 920     l = malloc(sizeof(LingeringCloseRec));
 921     if(l == NULL)
 922         goto fail;
 923     l->fd = fd;
 924     l->handler = NULL;
 925     l->timeout = NULL;
 926
 927     l->timeout = scheduleTimeEvent(10, lingeringCloseTimeoutHandler,
 928                                    sizeof(LingeringClosePtr), &l);
 929     if(l->timeout == NULL) {
 930         free(l);
 931         goto fail;
 932     }
 933
 934     l->handler = registerFdEvent(fd, POLLIN,
 935                                  lingeringCloseHandler,
 936                                  sizeof(LingeringClosePtr), &l);
 937     if(l->handler == NULL) {
 938         do_log(L_ERROR, "Couldn't schedule lingering close handler.\n");
 939         /* But don't close -- the timeout will do its work. */
 940     }
 941     return 1;
 942
 943  fail:
 944     do_log(L_ERROR, "Couldn't schedule lingering close.\n");
 945     CLOSE(fd);
 946     return 1;
 947 }
 948
 949 NetAddressPtr
 950 parseNetAddress(AtomListPtr list)
 951 {
 952     NetAddressPtr nl;
 953     int i, rc, rc6;
 954     char buf[100];
 955     struct in_addr ina;
 956 #ifdef HAVE_IPv6
 957     struct in6_addr ina6;
 958 #endif
 959
 960     nl = malloc((list->length + 1) * sizeof(NetAddressRec));
 961     if(nl == NULL) {
 962         do_log(L_ERROR, "Couldn't allocate network list.\n");
 963         return NULL;
 964     }
 965
 966     for(i = 0; i < list->length; i++) {
 967         int prefix;
 968         char *s = list->list[i]->string, *p;
 969         int n = list->list[i]->length;
 970         char *suffix;
 971
 972         while(*s == ' ' || *s == '\t') {
 973             s++;
 974             n--;
 975         }
 976
 977         if(n >= 100) {
 978             do_log(L_ERROR, "Network name too long.\n");
 979             goto fail;
 980         }
 981         p = memchr(s, '/', n);
 982         if(p) {
 983             memcpy(buf, s, p - s);
 984             buf[p - s] = '\0';
 985             prefix = strtol(p + 1, &suffix, 10);
 986         } else {
 987             char *s1, *s2;
 988             prefix = -1;
 989             strcpy(buf, s);
 990             s1 = strchr(s, ' ');
 991             s2 = strchr(s, '\t');
 992             if(s1 == NULL) suffix = s2;
 993             else if(s2 == NULL) suffix = s1;
 994             else if(s1 < s2) suffix = s1;
 995             else suffix = s2;
 996             if(suffix == NULL)
 997                 suffix = s + n;
 998         }
 999
1000         if(!isWhitespace(suffix)) {
1001             do_log(L_ERROR, "Couldn't parse network %s.\n", buf);
1002             goto fail;
1003         }
1004
1005         rc = 0; rc6 = 0;
1006         rc = inet_aton(buf, &ina);
1007 #ifdef HAVE_IPv6
1008         if(rc == 0) {
1009             rc6 = inet_pton(AF_INET6, buf, &ina6);
1010         }
1011 #endif
1012         if(rc == 0 && rc6 == 0) {
1013             do_log(L_ERROR, "Couldn't parse network %s.\n", buf);
1014             goto fail;
1015         }
1016         nl[i].prefix = prefix;
1017         if(rc) {
1018             nl[i].af = 4;
1019             memcpy(nl[i].data, &ina, 4);
1020         } else {
1021 #ifdef HAVE_IPv6
1022             nl[i].af = 6;
1023             memcpy(nl[i].data, &ina6, 16);
1024 #else
1025             abort();
1026 #endif
1027         }
1028     }
1029     nl[i].af = 0;
1030     return nl;
1031
1032  fail:
1033     free(nl);
1034     return NULL;
1035 }
1036
1037 /* Returns 1 if the first n bits of a and b are equal */
1038 static int
1039 bitmatch(const unsigned char *a, const unsigned char *b, int n)
1040 {
1041     if(n >= 8) {
1042         if(memcmp(a, b, n / 8) != 0)
1043             return 0;
1044     }
1045
1046     if(n % 8 != 0) {
1047         int mask = (~0) << (8 - n % 8);
1048         if((a[n / 8] & mask) != (b[n / 8] & mask))
1049             return 0;
1050     }
1051
1052     return 1;
1053 }
1054
1055 /* Returns 1 if the address in data is in list */
1056 static int
1057 match(int af, unsigned char *data, NetAddressPtr list)
1058 {
1059     int i;
1060 #ifdef HAVE_IPv6
1061     static const unsigned char v6mapped[] =
1062         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF };
1063 #endif
1064
1065     i = 0;
1066     while(list[i].af != 0) {
1067         if(af == 4 && list[i].af == 4) {
1068             if(bitmatch(data, list[i].data,
1069                         list[i].prefix >= 0 ? list[i].prefix : 32))
1070                 return 1;
1071 #ifdef HAVE_IPv6
1072         } else if(af == 6 && list[i].af == 6) {
1073             if(bitmatch(data, list[i].data,
1074                         list[i].prefix >= 0 ? list[i].prefix : 128))
1075                 return 1;
1076         } else if(af == 6 && list[i].af == 4) {
1077             if(bitmatch(data, v6mapped, 96)) {
1078                 if(bitmatch(data + 12, list[i].data,
1079                             list[i].prefix >= 0 ? list[i].prefix : 32))
1080                     return 1;
1081             }
1082         } else if(af == 4 && list[i].af == 6) {
1083             if(bitmatch(list[i].data, v6mapped, 96)) {
1084                 if(bitmatch(data, list[i].data + 12,
1085                             list[i].prefix >= 96 ?
1086                             list[i].prefix - 96 : 32))
1087                     return 1;
1088             }
1089 #endif
1090         } else {
1091             abort();
1092         }
1093         i++;
1094     }
1095     return 0;
1096 }
1097
1098 int
1099 netAddressMatch(int fd, NetAddressPtr list)
1100 {
1101     int rc;
1102     unsigned int len;
1103     struct sockaddr_in sain;
1104 #ifdef HAVE_IPv6
1105     struct sockaddr_in6 sain6;
1106 #endif
1107
1108     len = sizeof(sain);
1109     rc = getpeername(fd, (struct sockaddr*)&sain, &len);
1110     if(rc < 0) {
1111         do_log_error(L_ERROR, errno, "Couldn't get peer name");
1112         return -1;
1113     }
1114
1115     if(sain.sin_family == AF_INET) {
1116         return match(4, (unsigned char*)&sain.sin_addr, list);
1117 #ifdef HAVE_IPv6
1118     } else if(sain.sin_family == AF_INET6) {
1119         len = sizeof(sain6);
1120         rc = getpeername(fd, (struct sockaddr*)&sain6, &len);
1121         if(rc < 0) {
1122             do_log_error(L_ERROR, errno, "Couldn't get peer name");
1123             return -1;
1124         }
1125         if(sain6.sin6_family != AF_INET6) {
1126             do_log(L_ERROR, "Inconsistent peer name");
1127             return -1;
1128         }
1129         return match(6, (unsigned char*)&sain6.sin6_addr, list);
1130 #endif
1131     } else {
1132         do_log(L_ERROR, "Unknown address family %d\n", sain.sin_family);
1133         return -1;
1134     }
1135     return 0;
1136 }
1137
1138
1139
1140
1141
1142