| 1 | /* |
| 2 | * Windows networking abstraction. |
| 3 | */ |
| 4 | |
| 5 | #include <windows.h> |
| 6 | #include <winsock.h> |
| 7 | #include <stdio.h> |
| 8 | #include <stdlib.h> |
| 9 | |
| 10 | #include "putty.h" |
| 11 | #include "network.h" |
| 12 | #include "tree234.h" |
| 13 | |
| 14 | #define BUFFER_GRANULE 512 |
| 15 | |
| 16 | struct Socket_tag { |
| 17 | char *error; |
| 18 | SOCKET s; |
| 19 | sk_receiver_t receiver; |
| 20 | void *private_ptr; |
| 21 | struct buffer *head, *tail; |
| 22 | int writable; |
| 23 | int in_oob, sending_oob; |
| 24 | }; |
| 25 | |
| 26 | struct SockAddr_tag { |
| 27 | char *error; |
| 28 | unsigned long address; |
| 29 | }; |
| 30 | |
| 31 | struct buffer { |
| 32 | struct buffer *next; |
| 33 | int buflen, bufpos; |
| 34 | char buf[BUFFER_GRANULE]; |
| 35 | }; |
| 36 | |
| 37 | static tree234 *sktree; |
| 38 | |
| 39 | static int cmpfortree(void *av, void *bv) { |
| 40 | Socket a = (Socket)av, b = (Socket)bv; |
| 41 | unsigned long as = (unsigned long)a->s, bs = (unsigned long)b->s; |
| 42 | if (as < bs) return -1; |
| 43 | if (as > bs) return +1; |
| 44 | return 0; |
| 45 | } |
| 46 | |
| 47 | static int cmpforsearch(void *av, void *bv) { |
| 48 | Socket b = (Socket)bv; |
| 49 | unsigned long as = (unsigned long)av, bs = (unsigned long)b->s; |
| 50 | if (as < bs) return -1; |
| 51 | if (as > bs) return +1; |
| 52 | return 0; |
| 53 | } |
| 54 | |
| 55 | void sk_init(void) { |
| 56 | sktree = newtree234(cmpfortree); |
| 57 | } |
| 58 | |
| 59 | SockAddr sk_namelookup(char *host, char **canonicalname) { |
| 60 | SockAddr ret = smalloc(sizeof(struct SockAddr_tag)); |
| 61 | unsigned long a; |
| 62 | struct hostent *h; |
| 63 | |
| 64 | if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) { |
| 65 | if ( (h = gethostbyname(host)) == NULL) { |
| 66 | DWORD err = WSAGetLastError(); |
| 67 | ret->error = (err == WSAENETDOWN ? "Network is down" : |
| 68 | err == WSAHOST_NOT_FOUND ? "Host does not exist" : |
| 69 | err == WSATRY_AGAIN ? "Host not found" : |
| 70 | "gethostbyname: unknown error"); |
| 71 | } else { |
| 72 | ret->error = NULL; |
| 73 | memcpy (&a, h->h_addr, sizeof(a)); |
| 74 | *canonicalname = h->h_name; |
| 75 | } |
| 76 | } else { |
| 77 | *canonicalname = host; |
| 78 | } |
| 79 | ret->address = ntohl(a); |
| 80 | |
| 81 | return ret; |
| 82 | } |
| 83 | |
| 84 | void sk_addr_free(SockAddr addr) { |
| 85 | sfree(addr); |
| 86 | } |
| 87 | |
| 88 | Socket sk_new(SockAddr addr, int port, sk_receiver_t receiver) { |
| 89 | SOCKET s; |
| 90 | SOCKADDR_IN a; |
| 91 | DWORD err; |
| 92 | char *errstr; |
| 93 | Socket ret; |
| 94 | extern char *do_select(SOCKET skt, int startup); |
| 95 | |
| 96 | /* |
| 97 | * Create Socket structure. |
| 98 | */ |
| 99 | ret = smalloc(sizeof(struct Socket_tag)); |
| 100 | ret->error = NULL; |
| 101 | ret->receiver = receiver; |
| 102 | ret->head = ret->tail = NULL; |
| 103 | ret->writable = 1; /* to start with */ |
| 104 | ret->in_oob = FALSE; |
| 105 | ret->sending_oob = 0; |
| 106 | |
| 107 | /* |
| 108 | * Open socket. |
| 109 | */ |
| 110 | s = socket(AF_INET, SOCK_STREAM, 0); |
| 111 | ret->s = s; |
| 112 | |
| 113 | if (s == INVALID_SOCKET) { |
| 114 | err = WSAGetLastError(); |
| 115 | ret->error = (err == WSAENETDOWN ? "Network is down" : |
| 116 | err == WSAEAFNOSUPPORT ? "TCP/IP support not present" : |
| 117 | "socket(): unknown error"); |
| 118 | return ret; |
| 119 | } |
| 120 | |
| 121 | /* |
| 122 | * Bind to local address. |
| 123 | */ |
| 124 | a.sin_family = AF_INET; |
| 125 | a.sin_addr.s_addr = htonl(INADDR_ANY); |
| 126 | a.sin_port = htons(0); |
| 127 | if (bind (s, (struct sockaddr *)&a, sizeof(a)) == SOCKET_ERROR) { |
| 128 | err = WSAGetLastError(); |
| 129 | ret->error = (err == WSAENETDOWN ? "Network is down" : |
| 130 | "bind(): unknown error"); |
| 131 | return ret; |
| 132 | } |
| 133 | |
| 134 | /* |
| 135 | * Connect to remote address. |
| 136 | */ |
| 137 | a.sin_addr.s_addr = htonl(addr->address); |
| 138 | a.sin_port = htons((short)port); |
| 139 | if (connect (s, (struct sockaddr *)&a, sizeof(a)) == SOCKET_ERROR) { |
| 140 | err = WSAGetLastError(); |
| 141 | ret->error = (err == WSAENETDOWN ? "Network is down" : |
| 142 | err == WSAECONNREFUSED ? "Connection refused" : |
| 143 | err == WSAENETUNREACH ? "Network is unreachable" : |
| 144 | err == WSAEHOSTUNREACH ? "No route to host" : |
| 145 | "connect(): unknown error"); |
| 146 | return ret; |
| 147 | } |
| 148 | |
| 149 | /* Set up a select mechanism. This could be an AsyncSelect on a |
| 150 | * window, or an EventSelect on an event object. */ |
| 151 | errstr = do_select(s, 1); |
| 152 | if (errstr) { |
| 153 | ret->error = errstr; |
| 154 | return ret; |
| 155 | } |
| 156 | |
| 157 | add234(sktree, ret); |
| 158 | |
| 159 | return ret; |
| 160 | } |
| 161 | |
| 162 | void sk_close(Socket s) { |
| 163 | del234(sktree, s); |
| 164 | do_select(s->s, 0); |
| 165 | closesocket(s->s); |
| 166 | free(s); |
| 167 | } |
| 168 | |
| 169 | char *winsock_error_string(int error) { |
| 170 | switch (error) { |
| 171 | case WSAEACCES: return "Network error: Permission denied"; |
| 172 | case WSAEADDRINUSE: return "Network error: Address already in use"; |
| 173 | case WSAEADDRNOTAVAIL: return "Network error: Cannot assign requested address"; |
| 174 | case WSAEAFNOSUPPORT: return "Network error: Address family not supported by protocol family"; |
| 175 | case WSAEALREADY: return "Network error: Operation already in progress"; |
| 176 | case WSAECONNABORTED: return "Network error: Software caused connection abort"; |
| 177 | case WSAECONNREFUSED: return "Network error: Connection refused"; |
| 178 | case WSAECONNRESET: return "Network error: Connection reset by peer"; |
| 179 | case WSAEDESTADDRREQ: return "Network error: Destination address required"; |
| 180 | case WSAEFAULT: return "Network error: Bad address"; |
| 181 | case WSAEHOSTDOWN: return "Network error: Host is down"; |
| 182 | case WSAEHOSTUNREACH: return "Network error: No route to host"; |
| 183 | case WSAEINPROGRESS: return "Network error: Operation now in progress"; |
| 184 | case WSAEINTR: return "Network error: Interrupted function call"; |
| 185 | case WSAEINVAL: return "Network error: Invalid argument"; |
| 186 | case WSAEISCONN: return "Network error: Socket is already connected"; |
| 187 | case WSAEMFILE: return "Network error: Too many open files"; |
| 188 | case WSAEMSGSIZE: return "Network error: Message too long"; |
| 189 | case WSAENETDOWN: return "Network error: Network is down"; |
| 190 | case WSAENETRESET: return "Network error: Network dropped connection on reset"; |
| 191 | case WSAENETUNREACH: return "Network error: Network is unreachable"; |
| 192 | case WSAENOBUFS: return "Network error: No buffer space available"; |
| 193 | case WSAENOPROTOOPT: return "Network error: Bad protocol option"; |
| 194 | case WSAENOTCONN: return "Network error: Socket is not connected"; |
| 195 | case WSAENOTSOCK: return "Network error: Socket operation on non-socket"; |
| 196 | case WSAEOPNOTSUPP: return "Network error: Operation not supported"; |
| 197 | case WSAEPFNOSUPPORT: return "Network error: Protocol family not supported"; |
| 198 | case WSAEPROCLIM: return "Network error: Too many processes"; |
| 199 | case WSAEPROTONOSUPPORT: return "Network error: Protocol not supported"; |
| 200 | case WSAEPROTOTYPE: return "Network error: Protocol wrong type for socket"; |
| 201 | case WSAESHUTDOWN: return "Network error: Cannot send after socket shutdown"; |
| 202 | case WSAESOCKTNOSUPPORT: return "Network error: Socket type not supported"; |
| 203 | case WSAETIMEDOUT: return "Network error: Connection timed out"; |
| 204 | case WSAEWOULDBLOCK: return "Network error: Resource temporarily unavailable"; |
| 205 | case WSAEDISCON: return "Network error: Graceful shutdown in progress"; |
| 206 | default: return "Unknown network error"; |
| 207 | } |
| 208 | } |
| 209 | |
| 210 | /* |
| 211 | * The function which tries to send on a socket once it's deemed |
| 212 | * writable. |
| 213 | */ |
| 214 | void try_send(Socket s) { |
| 215 | while (s->head) { |
| 216 | int nsent; |
| 217 | DWORD err; |
| 218 | int len, urgentflag; |
| 219 | |
| 220 | if (s->sending_oob) { |
| 221 | urgentflag = MSG_OOB; |
| 222 | len = s->sending_oob; |
| 223 | } else { |
| 224 | urgentflag = 0; |
| 225 | len = s->head->buflen - s->head->bufpos; |
| 226 | } |
| 227 | |
| 228 | nsent = send(s->s, s->head->buf + s->head->bufpos, len, urgentflag); |
| 229 | noise_ultralight(nsent); |
| 230 | if (nsent <= 0) { |
| 231 | err = (nsent < 0 ? WSAGetLastError() : 0); |
| 232 | if (err == WSAEWOULDBLOCK) { |
| 233 | /* Perfectly normal: we've sent all we can for the moment. */ |
| 234 | s->writable = FALSE; |
| 235 | return; |
| 236 | } else if (nsent == 0 || |
| 237 | err == WSAECONNABORTED || |
| 238 | err == WSAECONNRESET) { |
| 239 | /* |
| 240 | * FIXME. This will have to be done better when we |
| 241 | * start managing multiple sockets (e.g. SSH port |
| 242 | * forwarding), because if we get CONNRESET while |
| 243 | * trying to write a particular forwarded socket |
| 244 | * then it isn't necessarily the end of the world. |
| 245 | * Ideally I'd like to pass the error code back to |
| 246 | * somewhere the next select_result() will see it, |
| 247 | * but that might be hard. Perhaps I should pass it |
| 248 | * back to be queued in the Windows front end bit. |
| 249 | */ |
| 250 | fatalbox(winsock_error_string(err)); |
| 251 | } else { |
| 252 | fatalbox(winsock_error_string(err)); |
| 253 | } |
| 254 | } else { |
| 255 | s->head->bufpos += nsent; |
| 256 | if (s->sending_oob) |
| 257 | s->sending_oob -= nsent; |
| 258 | if (s->head->bufpos >= s->head->buflen) { |
| 259 | struct buffer *tmp = s->head; |
| 260 | s->head = tmp->next; |
| 261 | free(tmp); |
| 262 | if (!s->head) |
| 263 | s->tail = NULL; |
| 264 | } |
| 265 | } |
| 266 | } |
| 267 | } |
| 268 | |
| 269 | void sk_write(Socket s, char *buf, int len) { |
| 270 | /* |
| 271 | * Add the data to the buffer list on the socket. |
| 272 | */ |
| 273 | if (s->tail && s->tail->buflen < BUFFER_GRANULE) { |
| 274 | int copylen = min(len, BUFFER_GRANULE - s->tail->buflen); |
| 275 | memcpy(s->tail->buf + s->tail->buflen, buf, copylen); |
| 276 | buf += copylen; |
| 277 | len -= copylen; |
| 278 | s->tail->buflen += copylen; |
| 279 | } |
| 280 | while (len > 0) { |
| 281 | int grainlen = min(len, BUFFER_GRANULE); |
| 282 | struct buffer *newbuf; |
| 283 | newbuf = smalloc(sizeof(struct buffer)); |
| 284 | newbuf->bufpos = 0; |
| 285 | newbuf->buflen = grainlen; |
| 286 | memcpy(newbuf->buf, buf, grainlen); |
| 287 | buf += grainlen; |
| 288 | len -= grainlen; |
| 289 | if (s->tail) |
| 290 | s->tail->next = newbuf; |
| 291 | else |
| 292 | s->head = s->tail = newbuf; |
| 293 | newbuf->next = NULL; |
| 294 | s->tail = newbuf; |
| 295 | } |
| 296 | |
| 297 | /* |
| 298 | * Now try sending from the start of the buffer list. |
| 299 | */ |
| 300 | if (s->writable) |
| 301 | try_send(s); |
| 302 | } |
| 303 | |
| 304 | void sk_write_oob(Socket s, char *buf, int len) { |
| 305 | /* |
| 306 | * Replace the buffer list on the socket with the data. |
| 307 | */ |
| 308 | if (!s->head) { |
| 309 | s->head = smalloc(sizeof(struct buffer)); |
| 310 | } else { |
| 311 | struct buffer *walk = s->head->next; |
| 312 | while (walk) { |
| 313 | struct buffer *tmp = walk; |
| 314 | walk = tmp->next; |
| 315 | free(tmp); |
| 316 | } |
| 317 | } |
| 318 | s->head->next = NULL; |
| 319 | s->tail = s->head; |
| 320 | s->head->buflen = len; |
| 321 | memcpy(s->head->buf, buf, len); |
| 322 | |
| 323 | /* |
| 324 | * Set the Urgent marker. |
| 325 | */ |
| 326 | s->sending_oob = len; |
| 327 | |
| 328 | /* |
| 329 | * Now try sending from the start of the buffer list. |
| 330 | */ |
| 331 | if (s->writable) |
| 332 | try_send(s); |
| 333 | } |
| 334 | |
| 335 | int select_result(WPARAM wParam, LPARAM lParam) { |
| 336 | int ret; |
| 337 | DWORD err; |
| 338 | char buf[BUFFER_GRANULE]; |
| 339 | Socket s; |
| 340 | u_long atmark; |
| 341 | |
| 342 | /* wParam is the socket itself */ |
| 343 | s = find234(sktree, (void *)wParam, cmpforsearch); |
| 344 | if (!s) |
| 345 | return 1; /* boggle */ |
| 346 | |
| 347 | if ((err = WSAGETSELECTERROR(lParam)) != 0) { |
| 348 | fatalbox(winsock_error_string(err)); |
| 349 | } |
| 350 | |
| 351 | noise_ultralight(lParam); |
| 352 | |
| 353 | switch (WSAGETSELECTEVENT(lParam)) { |
| 354 | case FD_READ: |
| 355 | ret = recv(s->s, buf, sizeof(buf), 0); |
| 356 | if (ret < 0) { |
| 357 | err = WSAGetLastError(); |
| 358 | if (err == WSAEWOULDBLOCK) { |
| 359 | break; |
| 360 | } |
| 361 | } |
| 362 | if (ret < 0) { |
| 363 | fatalbox(winsock_error_string(err)); |
| 364 | } else { |
| 365 | int type = s->in_oob ? 2 : 0; |
| 366 | s->in_oob = FALSE; |
| 367 | return s->receiver(s, type, buf, ret); |
| 368 | } |
| 369 | break; |
| 370 | case FD_OOB: |
| 371 | /* |
| 372 | * Read all data up to the OOB marker, and send it to the |
| 373 | * receiver with urgent==1 (OOB pending). |
| 374 | */ |
| 375 | atmark = 1; |
| 376 | s->in_oob = TRUE; |
| 377 | /* Some WinSock wrappers don't support this call, so we |
| 378 | * deliberately don't check the return value. If the call |
| 379 | * fails and does nothing, we will get back atmark==1, |
| 380 | * which is good enough to keep going at least. */ |
| 381 | ioctlsocket(s->s, SIOCATMARK, &atmark); |
| 382 | ret = recv(s->s, buf, sizeof(buf), MSG_OOB); |
| 383 | noise_ultralight(ret); |
| 384 | if (ret <= 0) { |
| 385 | fatalbox(ret == 0 ? "Internal networking trouble" : |
| 386 | winsock_error_string(WSAGetLastError())); |
| 387 | } else { |
| 388 | return s->receiver(s, atmark ? 2 : 1, buf, ret); |
| 389 | } |
| 390 | break; |
| 391 | case FD_WRITE: |
| 392 | s->writable = 1; |
| 393 | try_send(s); |
| 394 | break; |
| 395 | case FD_CLOSE: |
| 396 | /* Signal a close on the socket. */ |
| 397 | return s->receiver(s, 0, NULL, 0); |
| 398 | break; |
| 399 | } |
| 400 | |
| 401 | return 1; |
| 402 | } |
| 403 | |
| 404 | /* |
| 405 | * Each socket abstraction contains a `void *' private field in |
| 406 | * which the client can keep state. |
| 407 | */ |
| 408 | void sk_set_private_ptr(Socket s, void *ptr) { |
| 409 | s->private_ptr = ptr; |
| 410 | } |
| 411 | void *sk_get_private_ptr(Socket s) { |
| 412 | return s->private_ptr; |
| 413 | } |
| 414 | |
| 415 | /* |
| 416 | * Special error values are returned from sk_namelookup and sk_new |
| 417 | * if there's a problem. These functions extract an error message, |
| 418 | * or return NULL if there's no problem. |
| 419 | */ |
| 420 | char *sk_addr_error(SockAddr addr) { |
| 421 | return addr->error; |
| 422 | } |
| 423 | char *sk_socket_error(Socket s) { |
| 424 | return s->error; |
| 425 | } |
| 426 | |
| 427 | /* |
| 428 | * For Plink: enumerate all sockets currently active. |
| 429 | */ |
| 430 | SOCKET first_socket(enum234 *e) { |
| 431 | Socket s = first234(sktree, e); |
| 432 | return s ? s->s : INVALID_SOCKET; |
| 433 | } |
| 434 | SOCKET next_socket(enum234 *e) { |
| 435 | Socket s = next234(e); |
| 436 | return s ? s->s : INVALID_SOCKET; |
| 437 | } |