git.distorted.org.uk Git - u/mdw/putty/blob - winnet.c

   1 /*
   2  * Windows networking abstraction.
   3  *
   4  * Due to this clean abstraction it was possible
   5  * to easily implement IPv6 support :)
   6  *
   7  * IPv6 patch 1 (27 October 2000) Jeroen Massar <jeroen@unfix.org>
   8  *  - Preliminary hacked IPv6 support.
   9  *    - Connecting to IPv6 address (eg fec0:4242:4242:100:2d0:b7ff:fe8f:5d42) works.
  10  *    - Connecting to IPv6 hostname (eg heaven.ipv6.unfix.org) works.
  11  *  - Compiles as either IPv4 or IPv6.
  12  *
  13  * IPv6 patch 2 (29 October 2000) Jeroen Massar <jeroen@unfix.org>
  14  *  - When compiled as IPv6 it also allows connecting to IPv4 hosts.
  15  *  - Added some more documentation.
  16  *
  17  * IPv6 patch 3 (18 November 2000) Jeroen Massar <jeroen@unfix.org>
  18  *  - It now supports dynamically loading the IPv6 resolver dll's.
  19  *    This way we should be able to distribute one (1) binary
  20  *    which supports both IPv4 and IPv6.
  21  *  - getaddrinfo() and getnameinfo() are loaded dynamicaly if possible.
  22  *  - in6addr_any is defined in this file so we don't need to link to wship6.lib
  23  *  - The patch is now more unified so that we can still
  24  *    remove all IPv6 support by undef'ing IPV6.
  25  *    But where it fallsback to IPv4 it uses the IPv4 code which is already in place...
  26  *  - Canonical name resolving works.
  27  *
  28  * IPv6 patch 4 (07 January 2001) Jeroen Massar <jeroen@unfix.org>
  29  *  - patch against CVS of today, will be submitted to the bugs list
  30  *    as a 'cvs diff -u' on Simon's request...
  31  *
  32  */
  33
  34 /*
  35  * Define IPV6 to have IPv6 on-the-fly-loading support.
  36  * This means that one doesn't have to have an IPv6 stack to use it.
  37  * But if an IPv6 stack is found it is used with a fallback to IPv4.
  38  */
  39 /* #define IPV6 1 */
  40
  41 #ifdef IPV6
  42 #include <winsock2.h>
  43 #include <ws2tcpip.h>
  44 #include <tpipv6.h>
  45 #else
  46 #include <winsock.h>
  47 #endif
  48 #include <windows.h>
  49 #include <stdio.h>
  50 #include <stdlib.h>
  51 #include <assert.h>
  52
  53 #define DEFINE_PLUG_METHOD_MACROS
  54 #include "putty.h"
  55 #include "network.h"
  56 #include "tree234.h"
  57
  58 struct Socket_tag {
  59     struct socket_function_table *fn;
  60     /* the above variable absolutely *must* be the first in this structure */
  61     char *error;
  62     SOCKET s;
  63     Plug plug;
  64     void *private_ptr;
  65     bufchain output_data;
  66     int connected;
  67     int writable;
  68     int frozen; /* this causes readability notifications to be ignored */
  69     int frozen_readable; /* this means we missed at least one readability
  70                           * notification while we were frozen */
  71     char oobdata[1];
  72     int sending_oob;
  73     int oobinline;
  74 };
  75
  76 /*
  77  * We used to typedef struct Socket_tag *Socket.
  78  *
  79  * Since we have made the networking abstraction slightly more
  80  * abstract, Socket no longer means a tcp socket (it could mean
  81  * an ssl socket).  So now we must use Actual_Socket when we know
  82  * we are talking about a tcp socket.
  83  */
  84 typedef struct Socket_tag *Actual_Socket;
  85
  86 struct SockAddr_tag {
  87     char *error;
  88     /* address family this belongs to, AF_INET for IPv4, AF_INET6 for IPv6. */
  89     int family;
  90     unsigned long address;             /* Address IPv4 style. */
  91 #ifdef IPV6
  92     struct addrinfo *ai;               /* Address IPv6 style. */
  93 #endif
  94 };
  95
  96 static tree234 *sktree;
  97
  98 static int cmpfortree(void *av, void *bv)
  99 {
 100     Actual_Socket a = (Actual_Socket) av, b = (Actual_Socket) bv;
 101     unsigned long as = (unsigned long) a->s, bs = (unsigned long) b->s;
 102     if (as < bs)
 103         return -1;
 104     if (as > bs)
 105         return +1;
 106     return 0;
 107 }
 108
 109 static int cmpforsearch(void *av, void *bv)
 110 {
 111     Actual_Socket b = (Actual_Socket) bv;
 112     unsigned long as = (unsigned long) av, bs = (unsigned long) b->s;
 113     if (as < bs)
 114         return -1;
 115     if (as > bs)
 116         return +1;
 117     return 0;
 118 }
 119
 120 void sk_init(void)
 121 {
 122     sktree = newtree234(cmpfortree);
 123 }
 124
 125 char *winsock_error_string(int error)
 126 {
 127     switch (error) {
 128       case WSAEACCES:
 129         return "Network error: Permission denied";
 130       case WSAEADDRINUSE:
 131         return "Network error: Address already in use";
 132       case WSAEADDRNOTAVAIL:
 133         return "Network error: Cannot assign requested address";
 134       case WSAEAFNOSUPPORT:
 135         return
 136             "Network error: Address family not supported by protocol family";
 137       case WSAEALREADY:
 138         return "Network error: Operation already in progress";
 139       case WSAECONNABORTED:
 140         return "Network error: Software caused connection abort";
 141       case WSAECONNREFUSED:
 142         return "Network error: Connection refused";
 143       case WSAECONNRESET:
 144         return "Network error: Connection reset by peer";
 145       case WSAEDESTADDRREQ:
 146         return "Network error: Destination address required";
 147       case WSAEFAULT:
 148         return "Network error: Bad address";
 149       case WSAEHOSTDOWN:
 150         return "Network error: Host is down";
 151       case WSAEHOSTUNREACH:
 152         return "Network error: No route to host";
 153       case WSAEINPROGRESS:
 154         return "Network error: Operation now in progress";
 155       case WSAEINTR:
 156         return "Network error: Interrupted function call";
 157       case WSAEINVAL:
 158         return "Network error: Invalid argument";
 159       case WSAEISCONN:
 160         return "Network error: Socket is already connected";
 161       case WSAEMFILE:
 162         return "Network error: Too many open files";
 163       case WSAEMSGSIZE:
 164         return "Network error: Message too long";
 165       case WSAENETDOWN:
 166         return "Network error: Network is down";
 167       case WSAENETRESET:
 168         return "Network error: Network dropped connection on reset";
 169       case WSAENETUNREACH:
 170         return "Network error: Network is unreachable";
 171       case WSAENOBUFS:
 172         return "Network error: No buffer space available";
 173       case WSAENOPROTOOPT:
 174         return "Network error: Bad protocol option";
 175       case WSAENOTCONN:
 176         return "Network error: Socket is not connected";
 177       case WSAENOTSOCK:
 178         return "Network error: Socket operation on non-socket";
 179       case WSAEOPNOTSUPP:
 180         return "Network error: Operation not supported";
 181       case WSAEPFNOSUPPORT:
 182         return "Network error: Protocol family not supported";
 183       case WSAEPROCLIM:
 184         return "Network error: Too many processes";
 185       case WSAEPROTONOSUPPORT:
 186         return "Network error: Protocol not supported";
 187       case WSAEPROTOTYPE:
 188         return "Network error: Protocol wrong type for socket";
 189       case WSAESHUTDOWN:
 190         return "Network error: Cannot send after socket shutdown";
 191       case WSAESOCKTNOSUPPORT:
 192         return "Network error: Socket type not supported";
 193       case WSAETIMEDOUT:
 194         return "Network error: Connection timed out";
 195       case WSAEWOULDBLOCK:
 196         return "Network error: Resource temporarily unavailable";
 197       case WSAEDISCON:
 198         return "Network error: Graceful shutdown in progress";
 199       default:
 200         return "Unknown network error";
 201     }
 202 }
 203
 204 SockAddr sk_namelookup(char *host, char **canonicalname)
 205 {
 206     SockAddr ret = smalloc(sizeof(struct SockAddr_tag));
 207     unsigned long a;
 208     struct hostent *h = NULL;
 209     char realhost[8192];
 210
 211     /* Clear the structure and default to IPv4. */
 212     memset(ret, 0, sizeof(struct SockAddr_tag));
 213     ret->family = 0;                   /* We set this one when we have resolved the host. */
 214     *realhost = '\0';
 215
 216     if ((a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
 217 #ifdef IPV6
 218
 219         /* Try to get the getaddrinfo() function from wship6.dll */
 220         /* This way one doesn't need to have IPv6 dll's to use PuTTY and
 221          * it will fallback to IPv4. */
 222         typedef int (CALLBACK * FGETADDRINFO) (const char *nodename,
 223                                                const char *servname,
 224                                                const struct addrinfo *
 225                                                hints,
 226                                                struct addrinfo ** res);
 227         FGETADDRINFO fGetAddrInfo = NULL;
 228
 229         HINSTANCE dllWSHIP6 = LoadLibrary("wship6.dll");
 230         if (dllWSHIP6)
 231             fGetAddrInfo = (FGETADDRINFO) GetProcAddress(dllWSHIP6,
 232                                                          "getaddrinfo");
 233
 234         /*
 235          * Use fGetAddrInfo when it's available (which usually also
 236          * means IPv6 is installed...)
 237          */
 238         if (fGetAddrInfo) {
 239             /*debug(("Resolving \"%s\" with getaddrinfo()  (IPv4+IPv6 capable)...\n", host)); */
 240             if (fGetAddrInfo(host, NULL, NULL, &ret->ai) == 0)
 241                 ret->family = ret->ai->ai_family;
 242         } else
 243 #endif
 244         {
 245             /*
 246              * Otherwise use the IPv4-only gethostbyname...
 247              * (NOTE: we don't use gethostbyname as a
 248              * fallback!)
 249              */
 250             if (ret->family == 0) {
 251                 /*debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); */
 252                 if ( (h = gethostbyname(host)) )
 253                     ret->family = AF_INET;
 254             }
 255         }
 256         /*debug(("Done resolving...(family is %d) AF_INET = %d, AF_INET6 = %d\n", ret->family, AF_INET, AF_INET6)); */
 257
 258         if (ret->family == 0) {
 259             DWORD err = WSAGetLastError();
 260             ret->error = (err == WSAENETDOWN ? "Network is down" :
 261                           err ==
 262                           WSAHOST_NOT_FOUND ? "Host does not exist" : err
 263                           == WSATRY_AGAIN ? "Host not found" :
 264 #ifdef IPV6
 265                           fGetAddrInfo ? "getaddrinfo: unknown error" :
 266 #endif
 267                           "gethostbyname: unknown error");
 268 #ifdef DEBUG
 269             {
 270                 LPVOID lpMsgBuf;
 271                 FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
 272                               FORMAT_MESSAGE_FROM_SYSTEM |
 273                               FORMAT_MESSAGE_IGNORE_INSERTS, NULL, err,
 274                               MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
 275                               (LPTSTR) & lpMsgBuf, 0, NULL);
 276                 /*debug(("Error %ld: %s (h=%lx)\n", err, lpMsgBuf, h)); */
 277                 /* Free the buffer. */
 278                 LocalFree(lpMsgBuf);
 279             }
 280 #endif
 281         } else {
 282             ret->error = NULL;
 283
 284 #ifdef IPV6
 285             /* If we got an address info use that... */
 286             if (ret->ai) {
 287                 typedef int (CALLBACK * FGETNAMEINFO)
 288                  (const struct sockaddr FAR * sa, socklen_t salen,
 289                   char FAR * host, size_t hostlen, char FAR * serv,
 290                   size_t servlen, int flags);
 291                 FGETNAMEINFO fGetNameInfo = NULL;
 292
 293                 /* Are we in IPv4 fallback mode? */
 294                 /* We put the IPv4 address into the a variable so we can further-on use the IPv4 code... */
 295                 if (ret->family == AF_INET)
 296                     memcpy(&a,
 297                            (char *) &((SOCKADDR_IN *) ret->ai->
 298                                       ai_addr)->sin_addr, sizeof(a));
 299
 300                 /* Now let's find that canonicalname... */
 301                 if ((dllWSHIP6)
 302                     && (fGetNameInfo =
 303                         (FGETNAMEINFO) GetProcAddress(dllWSHIP6,
 304                                                       "getnameinfo"))) {
 305                     if (fGetNameInfo
 306                         ((struct sockaddr *) ret->ai->ai_addr,
 307                          ret->family ==
 308                          AF_INET ? sizeof(SOCKADDR_IN) :
 309                          sizeof(SOCKADDR_IN6), realhost,
 310                          sizeof(realhost), NULL, 0, 0) != 0) {
 311                         strncpy(realhost, host, sizeof(realhost));
 312                     }
 313                 }
 314             }
 315             /* We used the IPv4-only gethostbyname()... */
 316             else
 317 #endif
 318             {
 319                 memcpy(&a, h->h_addr, sizeof(a));
 320                 /* This way we are always sure the h->h_name is valid :) */
 321                 strncpy(realhost, h->h_name, sizeof(realhost));
 322             }
 323         }
 324 #ifdef IPV6
 325         FreeLibrary(dllWSHIP6);
 326 #endif
 327     } else {
 328         /*
 329          * This must be a numeric IPv4 address because it caused a
 330          * success return from inet_addr.
 331          */
 332         ret->family = AF_INET;
 333         strncpy(realhost, host, sizeof(realhost));
 334     }
 335     ret->address = ntohl(a);
 336     realhost[lenof(realhost)-1] = '\0';
 337     *canonicalname = smalloc(1+strlen(realhost));
 338     strcpy(*canonicalname, realhost);
 339     return ret;
 340 }
 341
 342 void sk_getaddr(SockAddr addr, char *buf, int buflen)
 343 {
 344 #ifdef IPV6
 345     if (addr->family == AF_INET) {
 346 #endif
 347         struct in_addr a;
 348         a.s_addr = htonl(addr->address);
 349         strncpy(buf, inet_ntoa(a), buflen);
 350 #ifdef IPV6
 351     } else {
 352         FIXME; /* I don't know how to get a text form of an IPv6 address. */
 353     }
 354 #endif
 355 }
 356
 357 void sk_addr_free(SockAddr addr)
 358 {
 359     sfree(addr);
 360 }
 361
 362 static Plug sk_tcp_plug(Socket sock, Plug p)
 363 {
 364     Actual_Socket s = (Actual_Socket) sock;
 365     Plug ret = s->plug;
 366     if (p)
 367         s->plug = p;
 368     return ret;
 369 }
 370
 371 static void sk_tcp_flush(Socket s)
 372 {
 373     /*
 374      * We send data to the socket as soon as we can anyway,
 375      * so we don't need to do anything here.  :-)
 376      */
 377 }
 378
 379 static void sk_tcp_close(Socket s);
 380 static int sk_tcp_write(Socket s, char *data, int len);
 381 static int sk_tcp_write_oob(Socket s, char *data, int len);
 382 static char *sk_tcp_socket_error(Socket s);
 383
 384 extern char *do_select(SOCKET skt, int startup);
 385
 386 Socket sk_register(void *sock, Plug plug)
 387 {
 388     static struct socket_function_table fn_table = {
 389         sk_tcp_plug,
 390         sk_tcp_close,
 391         sk_tcp_write,
 392         sk_tcp_write_oob,
 393         sk_tcp_flush,
 394         sk_tcp_socket_error
 395     };
 396
 397     DWORD err;
 398     char *errstr;
 399     Actual_Socket ret;
 400
 401     /*
 402      * Create Socket structure.
 403      */
 404     ret = smalloc(sizeof(struct Socket_tag));
 405     ret->fn = &fn_table;
 406     ret->error = NULL;
 407     ret->plug = plug;
 408     bufchain_init(&ret->output_data);
 409     ret->writable = 1;                 /* to start with */
 410     ret->sending_oob = 0;
 411     ret->frozen = 1;
 412     ret->frozen_readable = 0;
 413
 414     ret->s = (SOCKET)sock;
 415
 416     if (ret->s == INVALID_SOCKET) {
 417         err = WSAGetLastError();
 418         ret->error = winsock_error_string(err);
 419         return (Socket) ret;
 420     }
 421
 422     ret->oobinline = 0;
 423
 424     /* Set up a select mechanism. This could be an AsyncSelect on a
 425      * window, or an EventSelect on an event object. */
 426     errstr = do_select(ret->s, 1);
 427     if (errstr) {
 428         ret->error = errstr;
 429         return (Socket) ret;
 430     }
 431
 432     add234(sktree, ret);
 433
 434     return (Socket) ret;
 435 }
 436
 437 Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
 438               Plug plug)
 439 {
 440     static struct socket_function_table fn_table = {
 441         sk_tcp_plug,
 442         sk_tcp_close,
 443         sk_tcp_write,
 444         sk_tcp_write_oob,
 445         sk_tcp_flush,
 446         sk_tcp_socket_error
 447     };
 448
 449     SOCKET s;
 450 #ifdef IPV6
 451     SOCKADDR_IN6 a6;
 452 #endif
 453     SOCKADDR_IN a;
 454     DWORD err;
 455     char *errstr;
 456     Actual_Socket ret;
 457     short localport;
 458
 459     /*
 460      * Create Socket structure.
 461      */
 462     ret = smalloc(sizeof(struct Socket_tag));
 463     ret->fn = &fn_table;
 464     ret->error = NULL;
 465     ret->plug = plug;
 466     bufchain_init(&ret->output_data);
 467     ret->connected = 0;                /* to start with */
 468     ret->writable = 0;                 /* to start with */
 469     ret->sending_oob = 0;
 470     ret->frozen = 0;
 471     ret->frozen_readable = 0;
 472
 473     /*
 474      * Open socket.
 475      */
 476     s = socket(addr->family, SOCK_STREAM, 0);
 477     ret->s = s;
 478
 479     if (s == INVALID_SOCKET) {
 480         err = WSAGetLastError();
 481         ret->error = winsock_error_string(err);
 482         return (Socket) ret;
 483     }
 484
 485     ret->oobinline = oobinline;
 486     if (oobinline) {
 487         BOOL b = TRUE;
 488         setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b));
 489     }
 490
 491     /*
 492      * Bind to local address.
 493      */
 494     if (privport)
 495         localport = 1023;              /* count from 1023 downwards */
 496     else
 497         localport = 0;                 /* just use port 0 (ie winsock picks) */
 498
 499     /* Loop round trying to bind */
 500     while (1) {
 501         int retcode;
 502
 503 #ifdef IPV6
 504         if (addr->family == AF_INET6) {
 505             memset(&a6, 0, sizeof(a6));
 506             a6.sin6_family = AF_INET6;
 507 /*a6.sin6_addr      = in6addr_any; *//* == 0 */
 508             a6.sin6_port = htons(localport);
 509         } else
 510 #endif
 511         {
 512             a.sin_family = AF_INET;
 513             a.sin_addr.s_addr = htonl(INADDR_ANY);
 514             a.sin_port = htons(localport);
 515         }
 516 #ifdef IPV6
 517         retcode = bind(s, (addr->family == AF_INET6 ?
 518                            (struct sockaddr *) &a6 :
 519                            (struct sockaddr *) &a),
 520                        (addr->family ==
 521                         AF_INET6 ? sizeof(a6) : sizeof(a)));
 522 #else
 523         retcode = bind(s, (struct sockaddr *) &a, sizeof(a));
 524 #endif
 525         if (retcode != SOCKET_ERROR) {
 526             err = 0;
 527             break;                     /* done */
 528         } else {
 529             err = WSAGetLastError();
 530             if (err != WSAEADDRINUSE)  /* failed, for a bad reason */
 531                 break;
 532         }
 533
 534         if (localport == 0)
 535             break;                     /* we're only looping once */
 536         localport--;
 537         if (localport == 0)
 538             break;                     /* we might have got to the end */
 539     }
 540
 541     if (err) {
 542         ret->error = winsock_error_string(err);
 543         return (Socket) ret;
 544     }
 545
 546     /*
 547      * Connect to remote address.
 548      */
 549 #ifdef IPV6
 550     if (addr->family == AF_INET6) {
 551         memset(&a, 0, sizeof(a));
 552         a6.sin6_family = AF_INET6;
 553         a6.sin6_port = htons((short) port);
 554         a6.sin6_addr =
 555             ((struct sockaddr_in6 *) addr->ai->ai_addr)->sin6_addr;
 556     } else
 557 #endif
 558     {
 559         a.sin_family = AF_INET;
 560         a.sin_addr.s_addr = htonl(addr->address);
 561         a.sin_port = htons((short) port);
 562     }
 563
 564     /* Set up a select mechanism. This could be an AsyncSelect on a
 565      * window, or an EventSelect on an event object. */
 566     errstr = do_select(s, 1);
 567     if (errstr) {
 568         ret->error = errstr;
 569         return (Socket) ret;
 570     }
 571
 572     if ((
 573 #ifdef IPV6
 574             connect(s, ((addr->family == AF_INET6) ?
 575                         (struct sockaddr *) &a6 : (struct sockaddr *) &a),
 576                     (addr->family == AF_INET6) ? sizeof(a6) : sizeof(a))
 577 #else
 578             connect(s, (struct sockaddr *) &a, sizeof(a))
 579 #endif
 580         ) == SOCKET_ERROR) {
 581         err = WSAGetLastError();
 582         /*
 583          * We expect a potential EWOULDBLOCK here, because the
 584          * chances are the front end has done a select for
 585          * FD_CONNECT, so that connect() will complete
 586          * asynchronously.
 587          */
 588         if ( err != WSAEWOULDBLOCK ) {
 589             ret->error = winsock_error_string(err);
 590             return (Socket) ret;
 591         }
 592     } else {
 593         /*
 594          * If we _don't_ get EWOULDBLOCK, the connect has completed
 595          * and we should set the socket as writable.
 596          */
 597         ret->writable = 1;
 598     }
 599
 600     add234(sktree, ret);
 601
 602     return (Socket) ret;
 603 }
 604
 605 Socket sk_newlistener(int port, Plug plug, int local_host_only)
 606 {
 607     static struct socket_function_table fn_table = {
 608         sk_tcp_plug,
 609         sk_tcp_close,
 610         sk_tcp_write,
 611         sk_tcp_write_oob,
 612         sk_tcp_flush,
 613         sk_tcp_socket_error
 614     };
 615
 616     SOCKET s;
 617 #ifdef IPV6
 618     SOCKADDR_IN6 a6;
 619 #endif
 620     SOCKADDR_IN a;
 621     DWORD err;
 622     char *errstr;
 623     Actual_Socket ret;
 624     int retcode;
 625     int on = 1;
 626
 627     /*
 628      * Create Socket structure.
 629      */
 630     ret = smalloc(sizeof(struct Socket_tag));
 631     ret->fn = &fn_table;
 632     ret->error = NULL;
 633     ret->plug = plug;
 634     bufchain_init(&ret->output_data);
 635     ret->writable = 0;                 /* to start with */
 636     ret->sending_oob = 0;
 637     ret->frozen = 0;
 638     ret->frozen_readable = 0;
 639
 640     /*
 641      * Open socket.
 642      */
 643     s = socket(AF_INET, SOCK_STREAM, 0);
 644     ret->s = s;
 645
 646     if (s == INVALID_SOCKET) {
 647         err = WSAGetLastError();
 648         ret->error = winsock_error_string(err);
 649         return (Socket) ret;
 650     }
 651
 652     ret->oobinline = 0;
 653
 654
 655     setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
 656
 657
 658 #ifdef IPV6
 659         if (addr->family == AF_INET6) {
 660             memset(&a6, 0, sizeof(a6));
 661             a6.sin6_family = AF_INET6;
 662             if (local_host_only)
 663                 a6.sin6_addr = in6addr_loopback;
 664             else
 665                 a6.sin6_addr = in6addr_any;
 666             a6.sin6_port = htons(port);
 667         } else
 668 #endif
 669         {
 670             a.sin_family = AF_INET;
 671             if (local_host_only)
 672                 a.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 673             else
 674                 a.sin_addr.s_addr = htonl(INADDR_ANY);
 675             a.sin_port = htons((short)port);
 676         }
 677 #ifdef IPV6
 678         retcode = bind(s, (addr->family == AF_INET6 ?
 679                            (struct sockaddr *) &a6 :
 680                            (struct sockaddr *) &a),
 681                        (addr->family ==
 682                         AF_INET6 ? sizeof(a6) : sizeof(a)));
 683 #else
 684         retcode = bind(s, (struct sockaddr *) &a, sizeof(a));
 685 #endif
 686         if (retcode != SOCKET_ERROR) {
 687             err = 0;
 688         } else {
 689             err = WSAGetLastError();
 690         }
 691
 692     if (err) {
 693         ret->error = winsock_error_string(err);
 694         return (Socket) ret;
 695     }
 696
 697
 698     if (listen(s, SOMAXCONN) == SOCKET_ERROR) {
 699         closesocket(s);
 700         ret->error = winsock_error_string(err);
 701         return (Socket) ret;
 702     }
 703
 704     /* Set up a select mechanism. This could be an AsyncSelect on a
 705      * window, or an EventSelect on an event object. */
 706     errstr = do_select(s, 1);
 707     if (errstr) {
 708         ret->error = errstr;
 709         return (Socket) ret;
 710     }
 711
 712     add234(sktree, ret);
 713
 714     return (Socket) ret;
 715 }
 716
 717 static void sk_tcp_close(Socket sock)
 718 {
 719     extern char *do_select(SOCKET skt, int startup);
 720     Actual_Socket s = (Actual_Socket) sock;
 721
 722     del234(sktree, s);
 723     do_select(s->s, 0);
 724     closesocket(s->s);
 725     sfree(s);
 726 }
 727
 728 /*
 729  * The function which tries to send on a socket once it's deemed
 730  * writable.
 731  */
 732 void try_send(Actual_Socket s)
 733 {
 734     while (s->sending_oob || bufchain_size(&s->output_data) > 0) {
 735         int nsent;
 736         DWORD err;
 737         void *data;
 738         int len, urgentflag;
 739
 740         if (s->sending_oob) {
 741             urgentflag = MSG_OOB;
 742             len = s->sending_oob;
 743             data = &s->oobdata;
 744         } else {
 745             urgentflag = 0;
 746             bufchain_prefix(&s->output_data, &data, &len);
 747         }
 748         nsent = send(s->s, data, len, urgentflag);
 749         noise_ultralight(nsent);
 750         if (nsent <= 0) {
 751             err = (nsent < 0 ? WSAGetLastError() : 0);
 752             if ((err < WSABASEERR && nsent < 0) || err == WSAEWOULDBLOCK) {
 753                 /*
 754                  * Perfectly normal: we've sent all we can for the moment.
 755                  *
 756                  * (Some WinSock send() implementations can return
 757                  * <0 but leave no sensible error indication -
 758                  * WSAGetLastError() is called but returns zero or
 759                  * a small number - so we check that case and treat
 760                  * it just like WSAEWOULDBLOCK.)
 761                  */
 762                 s->writable = FALSE;
 763                 return;
 764             } else if (nsent == 0 ||
 765                        err == WSAECONNABORTED || err == WSAECONNRESET) {
 766                 /*
 767                  * ASSUMPTION:
 768                  *
 769                  * I'm assuming here that if a TCP connection is
 770                  * reset or aborted once established, we will be
 771                  * notified by a select event rather than a
 772                  * CONNABORTED or CONNRESET from send(). In other
 773                  * words, I'm assuming CONNABORTED and CONNRESET
 774                  * don't come back from a _nonblocking_ send(),
 775                  * because the local side doesn't know they've
 776                  * happened until it waits for a response to its
 777                  * TCP segment - so the error will arrive
 778                  * asynchronously.
 779                  *
 780                  * If I'm wrong, this will be a really nasty case,
 781                  * because we can't necessarily call plug_closing()
 782                  * without having to make half the SSH code
 783                  * reentrant; so instead we'll have to schedule a
 784                  * call to plug_closing() for some suitable future
 785                  * time.
 786                  */
 787                 fatalbox("SERIOUS NETWORK INTERNAL ERROR: %s\n"
 788                          "Please report this immediately to "
 789                          "<putty@projects.tartarus.org>.",
 790                          winsock_error_string(err));
 791             } else {
 792                 fatalbox(winsock_error_string(err));
 793             }
 794         } else {
 795             if (s->sending_oob) {
 796                 if (nsent < len) {
 797                     memmove(s->oobdata, s->oobdata+nsent, len-nsent);
 798                     s->sending_oob = len - nsent;
 799                 } else {
 800                     s->sending_oob = 0;
 801                 }
 802             } else {
 803                 bufchain_consume(&s->output_data, nsent);
 804             }
 805         }
 806     }
 807 }
 808
 809 static int sk_tcp_write(Socket sock, char *buf, int len)
 810 {
 811     Actual_Socket s = (Actual_Socket) sock;
 812
 813     /*
 814      * Add the data to the buffer list on the socket.
 815      */
 816     bufchain_add(&s->output_data, buf, len);
 817
 818     /*
 819      * Now try sending from the start of the buffer list.
 820      */
 821     if (s->writable)
 822         try_send(s);
 823
 824     return bufchain_size(&s->output_data);
 825 }
 826
 827 static int sk_tcp_write_oob(Socket sock, char *buf, int len)
 828 {
 829     Actual_Socket s = (Actual_Socket) sock;
 830
 831     /*
 832      * Replace the buffer list on the socket with the data.
 833      */
 834     bufchain_clear(&s->output_data);
 835     assert(len <= sizeof(s->oobdata));
 836     memcpy(s->oobdata, buf, len);
 837     s->sending_oob = len;
 838
 839     /*
 840      * Now try sending from the start of the buffer list.
 841      */
 842     if (s->writable)
 843         try_send(s);
 844
 845     return s->sending_oob;
 846 }
 847
 848 int select_result(WPARAM wParam, LPARAM lParam)
 849 {
 850     int ret, open;
 851     DWORD err;
 852     char buf[20480];                   /* nice big buffer for plenty of speed */
 853     Actual_Socket s;
 854     u_long atmark;
 855
 856     /* wParam is the socket itself */
 857     s = find234(sktree, (void *) wParam, cmpforsearch);
 858     if (!s)
 859         return 1;                      /* boggle */
 860
 861     if ((err = WSAGETSELECTERROR(lParam)) != 0) {
 862         /*
 863          * An error has occurred on this socket. Pass it to the
 864          * plug.
 865          */
 866         return plug_closing(s->plug, winsock_error_string(err), err, 0);
 867     }
 868
 869     noise_ultralight(lParam);
 870
 871     switch (WSAGETSELECTEVENT(lParam)) {
 872       case FD_CONNECT:
 873         s->connected = s->writable = 1;
 874         break;
 875       case FD_READ:
 876         /* In the case the socket is still frozen, we don't even bother */
 877         if (s->frozen) {
 878             s->frozen_readable = 1;
 879             break;
 880         }
 881
 882         /*
 883          * We have received data on the socket. For an oobinline
 884          * socket, this might be data _before_ an urgent pointer,
 885          * in which case we send it to the back end with type==1
 886          * (data prior to urgent).
 887          */
 888         if (s->oobinline) {
 889             atmark = 1;
 890             ioctlsocket(s->s, SIOCATMARK, &atmark);
 891             /*
 892              * Avoid checking the return value from ioctlsocket(),
 893              * on the grounds that some WinSock wrappers don't
 894              * support it. If it does nothing, we get atmark==1,
 895              * which is equivalent to `no OOB pending', so the
 896              * effect will be to non-OOB-ify any OOB data.
 897              */
 898         } else
 899             atmark = 1;
 900
 901         ret = recv(s->s, buf, sizeof(buf), 0);
 902         noise_ultralight(ret);
 903         if (ret < 0) {
 904             err = WSAGetLastError();
 905             if (err == WSAEWOULDBLOCK) {
 906                 break;
 907             }
 908         }
 909         if (ret < 0) {
 910             return plug_closing(s->plug, winsock_error_string(err), err,
 911                                 0);
 912         } else if (0 == ret) {
 913             return plug_closing(s->plug, NULL, 0, 0);
 914         } else {
 915             return plug_receive(s->plug, atmark ? 0 : 1, buf, ret);
 916         }
 917         break;
 918       case FD_OOB:
 919         /*
 920          * This will only happen on a non-oobinline socket. It
 921          * indicates that we can immediately perform an OOB read
 922          * and get back OOB data, which we will send to the back
 923          * end with type==2 (urgent data).
 924          */
 925         ret = recv(s->s, buf, sizeof(buf), MSG_OOB);
 926         noise_ultralight(ret);
 927         if (ret <= 0) {
 928             fatalbox(ret == 0 ? "Internal networking trouble" :
 929                      winsock_error_string(WSAGetLastError()));
 930         } else {
 931             return plug_receive(s->plug, 2, buf, ret);
 932         }
 933         break;
 934       case FD_WRITE:
 935         {
 936             int bufsize_before, bufsize_after;
 937             s->writable = 1;
 938             bufsize_before = s->sending_oob + bufchain_size(&s->output_data);
 939             try_send(s);
 940             bufsize_after = s->sending_oob + bufchain_size(&s->output_data);
 941             if (bufsize_after < bufsize_before)
 942                 plug_sent(s->plug, bufsize_after);
 943         }
 944         break;
 945       case FD_CLOSE:
 946         /* Signal a close on the socket. First read any outstanding data. */
 947         open = 1;
 948         do {
 949             ret = recv(s->s, buf, sizeof(buf), 0);
 950             if (ret < 0) {
 951                 err = WSAGetLastError();
 952                 if (err == WSAEWOULDBLOCK)
 953                     break;
 954                 return plug_closing(s->plug, winsock_error_string(err),
 955                                     err, 0);
 956             } else {
 957                 if (ret)
 958                     open &= plug_receive(s->plug, 0, buf, ret);
 959                 else
 960                     open &= plug_closing(s->plug, NULL, 0, 0);
 961             }
 962         } while (ret > 0);
 963         return open;
 964        case FD_ACCEPT:
 965         {
 966             struct sockaddr isa;
 967             int addrlen = sizeof(struct sockaddr);
 968             SOCKET t;  /* socket of connection */
 969
 970             memset(&isa, 0, sizeof(struct sockaddr));
 971             err = 0;
 972             t = accept(s->s,&isa,&addrlen);
 973             if (t == INVALID_SOCKET)
 974             {
 975                 err = WSAGetLastError();
 976                 if (err == WSATRY_AGAIN)
 977                     break;
 978             }
 979
 980             if (plug_accepting(s->plug, (void*)t)) {
 981                 closesocket(t);        /* denied or error */
 982             }
 983         }
 984     }
 985
 986     return 1;
 987 }
 988
 989 /*
 990  * Each socket abstraction contains a `void *' private field in
 991  * which the client can keep state.
 992  */
 993 void sk_set_private_ptr(Socket sock, void *ptr)
 994 {
 995     Actual_Socket s = (Actual_Socket) sock;
 996     s->private_ptr = ptr;
 997 }
 998
 999 void *sk_get_private_ptr(Socket sock)
1000 {
1001     Actual_Socket s = (Actual_Socket) sock;
1002     return s->private_ptr;
1003 }
1004
1005 /*
1006  * Special error values are returned from sk_namelookup and sk_new
1007  * if there's a problem. These functions extract an error message,
1008  * or return NULL if there's no problem.
1009  */
1010 char *sk_addr_error(SockAddr addr)
1011 {
1012     return addr->error;
1013 }
1014 static char *sk_tcp_socket_error(Socket sock)
1015 {
1016     Actual_Socket s = (Actual_Socket) sock;
1017     return s->error;
1018 }
1019
1020 void sk_set_frozen(Socket sock, int is_frozen)
1021 {
1022     Actual_Socket s = (Actual_Socket) sock;
1023     if (s->frozen == is_frozen)
1024         return;
1025     s->frozen = is_frozen;
1026     if (!is_frozen && s->frozen_readable) {
1027         char c;
1028         recv(s->s, &c, 1, MSG_PEEK);
1029     }
1030     s->frozen_readable = 0;
1031 }
1032
1033 /*
1034  * For Plink: enumerate all sockets currently active.
1035  */
1036 SOCKET first_socket(int *state)
1037 {
1038     Actual_Socket s;
1039     *state = 0;
1040     s = index234(sktree, (*state)++);
1041     return s ? s->s : INVALID_SOCKET;
1042 }
1043
1044 SOCKET next_socket(int *state)
1045 {
1046     Actual_Socket s = index234(sktree, (*state)++);
1047     return s ? s->s : INVALID_SOCKET;
1048 }