| 1 | /* |
| 2 | * Unix networking abstraction. |
| 3 | */ |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <stdlib.h> |
| 7 | #include <assert.h> |
| 8 | #include <errno.h> |
| 9 | #include <fcntl.h> |
| 10 | #include <unistd.h> |
| 11 | #include <sys/types.h> |
| 12 | #include <sys/socket.h> |
| 13 | #include <sys/ioctl.h> |
| 14 | #include <arpa/inet.h> |
| 15 | #include <netinet/in.h> |
| 16 | #include <netinet/tcp.h> |
| 17 | #include <netdb.h> |
| 18 | |
| 19 | #define DEFINE_PLUG_METHOD_MACROS |
| 20 | #include "putty.h" |
| 21 | #include "network.h" |
| 22 | #include "tree234.h" |
| 23 | |
| 24 | #define ipv4_is_loopback(addr) (inet_netof(addr) == IN_LOOPBACKNET) |
| 25 | |
| 26 | struct Socket_tag { |
| 27 | struct socket_function_table *fn; |
| 28 | /* the above variable absolutely *must* be the first in this structure */ |
| 29 | char *error; |
| 30 | int s; |
| 31 | Plug plug; |
| 32 | void *private_ptr; |
| 33 | bufchain output_data; |
| 34 | int connected; |
| 35 | int writable; |
| 36 | int frozen; /* this causes readability notifications to be ignored */ |
| 37 | int frozen_readable; /* this means we missed at least one readability |
| 38 | * notification while we were frozen */ |
| 39 | int localhost_only; /* for listening sockets */ |
| 40 | char oobdata[1]; |
| 41 | int sending_oob; |
| 42 | int oobpending; /* is there OOB data available to read? */ |
| 43 | int oobinline; |
| 44 | int pending_error; /* in case send() returns error */ |
| 45 | int listener; |
| 46 | }; |
| 47 | |
| 48 | /* |
| 49 | * We used to typedef struct Socket_tag *Socket. |
| 50 | * |
| 51 | * Since we have made the networking abstraction slightly more |
| 52 | * abstract, Socket no longer means a tcp socket (it could mean |
| 53 | * an ssl socket). So now we must use Actual_Socket when we know |
| 54 | * we are talking about a tcp socket. |
| 55 | */ |
| 56 | typedef struct Socket_tag *Actual_Socket; |
| 57 | |
| 58 | struct SockAddr_tag { |
| 59 | char *error; |
| 60 | /* |
| 61 | * Which address family this address belongs to. AF_INET for |
| 62 | * IPv4; AF_INET6 for IPv6; AF_UNSPEC indicates that name |
| 63 | * resolution has not been done and a simple host name is held |
| 64 | * in this SockAddr structure. |
| 65 | */ |
| 66 | int family; |
| 67 | unsigned long address; /* Address IPv4 style. */ |
| 68 | #ifdef IPV6 |
| 69 | struct addrinfo *ai; /* Address IPv6 style. */ |
| 70 | #endif |
| 71 | char hostname[512]; /* Store an unresolved host name. */ |
| 72 | }; |
| 73 | |
| 74 | static tree234 *sktree; |
| 75 | |
| 76 | static int cmpfortree(void *av, void *bv) |
| 77 | { |
| 78 | Actual_Socket a = (Actual_Socket) av, b = (Actual_Socket) bv; |
| 79 | int as = a->s, bs = b->s; |
| 80 | if (as < bs) |
| 81 | return -1; |
| 82 | if (as > bs) |
| 83 | return +1; |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | static int cmpforsearch(void *av, void *bv) |
| 88 | { |
| 89 | Actual_Socket b = (Actual_Socket) bv; |
| 90 | int as = (int) av, bs = b->s; |
| 91 | if (as < bs) |
| 92 | return -1; |
| 93 | if (as > bs) |
| 94 | return +1; |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | void sk_init(void) |
| 99 | { |
| 100 | sktree = newtree234(cmpfortree); |
| 101 | } |
| 102 | |
| 103 | void sk_cleanup(void) |
| 104 | { |
| 105 | Actual_Socket s; |
| 106 | int i; |
| 107 | |
| 108 | if (sktree) { |
| 109 | for (i = 0; (s = index234(sktree, i)) != NULL; i++) { |
| 110 | close(s->s); |
| 111 | } |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | char *error_string(int error) |
| 116 | { |
| 117 | return strerror(error); |
| 118 | } |
| 119 | |
| 120 | SockAddr sk_namelookup(char *host, char **canonicalname) |
| 121 | { |
| 122 | SockAddr ret = smalloc(sizeof(struct SockAddr_tag)); |
| 123 | unsigned long a; |
| 124 | struct hostent *h = NULL; |
| 125 | char realhost[8192]; |
| 126 | |
| 127 | /* Clear the structure and default to IPv4. */ |
| 128 | memset(ret, 0, sizeof(struct SockAddr_tag)); |
| 129 | ret->family = 0; /* We set this one when we have resolved the host. */ |
| 130 | *realhost = '\0'; |
| 131 | ret->error = NULL; |
| 132 | |
| 133 | if ((a = inet_addr(host)) == (unsigned long) INADDR_NONE) { |
| 134 | #ifdef IPV6 |
| 135 | if (getaddrinfo(host, NULL, NULL, &ret->ai) == 0) { |
| 136 | ret->family = ret->ai->ai_family; |
| 137 | } else |
| 138 | #endif |
| 139 | { |
| 140 | /* |
| 141 | * Otherwise use the IPv4-only gethostbyname... (NOTE: |
| 142 | * we don't use gethostbyname as a fallback!) |
| 143 | */ |
| 144 | if (ret->family == 0) { |
| 145 | /*debug(("Resolving \"%s\" with gethostbyname() (IPv4 only)...\n", host)); */ |
| 146 | if ( (h = gethostbyname(host)) ) |
| 147 | ret->family = AF_INET; |
| 148 | } |
| 149 | if (ret->family == 0) { |
| 150 | ret->error = (h_errno == HOST_NOT_FOUND || |
| 151 | h_errno == NO_DATA || |
| 152 | h_errno == NO_ADDRESS ? "Host does not exist" : |
| 153 | h_errno == TRY_AGAIN ? |
| 154 | "Temporary name service failure" : |
| 155 | "gethostbyname: unknown error"); |
| 156 | return ret; |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | #ifdef IPV6 |
| 161 | /* If we got an address info use that... */ |
| 162 | if (ret->ai) { |
| 163 | |
| 164 | /* Are we in IPv4 fallback mode? */ |
| 165 | /* We put the IPv4 address into the a variable so we can further-on use the IPv4 code... */ |
| 166 | if (ret->family == AF_INET) |
| 167 | memcpy(&a, |
| 168 | (char *) &((struct sockaddr_in *) ret->ai-> |
| 169 | ai_addr)->sin_addr, sizeof(a)); |
| 170 | |
| 171 | /* Now let's find that canonicalname... */ |
| 172 | if (getnameinfo((struct sockaddr *) ret->ai->ai_addr, |
| 173 | ret->family == |
| 174 | AF_INET ? sizeof(struct sockaddr_in) : |
| 175 | sizeof(struct sockaddr_in6), realhost, |
| 176 | sizeof(realhost), NULL, 0, 0) != 0) { |
| 177 | strncpy(realhost, host, sizeof(realhost)); |
| 178 | } |
| 179 | } |
| 180 | /* We used the IPv4-only gethostbyname()... */ |
| 181 | else |
| 182 | #endif |
| 183 | { |
| 184 | memcpy(&a, h->h_addr, sizeof(a)); |
| 185 | /* This way we are always sure the h->h_name is valid :) */ |
| 186 | strncpy(realhost, h->h_name, sizeof(realhost)); |
| 187 | } |
| 188 | } else { |
| 189 | /* |
| 190 | * This must be a numeric IPv4 address because it caused a |
| 191 | * success return from inet_addr. |
| 192 | */ |
| 193 | ret->family = AF_INET; |
| 194 | strncpy(realhost, host, sizeof(realhost)); |
| 195 | } |
| 196 | ret->address = ntohl(a); |
| 197 | realhost[lenof(realhost)-1] = '\0'; |
| 198 | *canonicalname = smalloc(1+strlen(realhost)); |
| 199 | strcpy(*canonicalname, realhost); |
| 200 | return ret; |
| 201 | } |
| 202 | |
| 203 | SockAddr sk_nonamelookup(char *host) |
| 204 | { |
| 205 | SockAddr ret = smalloc(sizeof(struct SockAddr_tag)); |
| 206 | ret->family = AF_UNSPEC; |
| 207 | strncpy(ret->hostname, host, lenof(ret->hostname)); |
| 208 | ret->hostname[lenof(ret->hostname)-1] = '\0'; |
| 209 | return ret; |
| 210 | } |
| 211 | |
| 212 | void sk_getaddr(SockAddr addr, char *buf, int buflen) |
| 213 | { |
| 214 | #ifdef IPV6 |
| 215 | if (addr->family == AF_INET6) { |
| 216 | FIXME; /* I don't know how to get a text form of an IPv6 address. */ |
| 217 | } else |
| 218 | #endif |
| 219 | if (addr->family == AF_INET) { |
| 220 | struct in_addr a; |
| 221 | a.s_addr = htonl(addr->address); |
| 222 | strncpy(buf, inet_ntoa(a), buflen); |
| 223 | buf[buflen-1] = '\0'; |
| 224 | } else { |
| 225 | assert(addr->family == AF_UNSPEC); |
| 226 | strncpy(buf, addr->hostname, buflen); |
| 227 | buf[buflen-1] = '\0'; |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | int sk_hostname_is_local(char *name) |
| 232 | { |
| 233 | return !strcmp(name, "localhost"); |
| 234 | } |
| 235 | |
| 236 | int sk_address_is_local(SockAddr addr) |
| 237 | { |
| 238 | #ifdef IPV6 |
| 239 | if (addr->family == AF_INET6) { |
| 240 | FIXME; /* someone who can compile for IPV6 had better do this bit */ |
| 241 | } else |
| 242 | #endif |
| 243 | if (addr->family == AF_INET) { |
| 244 | struct in_addr a; |
| 245 | a.s_addr = htonl(addr->address); |
| 246 | return ipv4_is_loopback(a); |
| 247 | } else { |
| 248 | assert(addr->family == AF_UNSPEC); |
| 249 | return 0; /* we don't know; assume not */ |
| 250 | } |
| 251 | } |
| 252 | |
| 253 | int sk_addrtype(SockAddr addr) |
| 254 | { |
| 255 | return (addr->family == AF_INET ? ADDRTYPE_IPV4 : |
| 256 | #ifdef IPV6 |
| 257 | addr->family == AF_INET6 ? ADDRTYPE_IPV6 : |
| 258 | #endif |
| 259 | ADDRTYPE_NAME); |
| 260 | } |
| 261 | |
| 262 | void sk_addrcopy(SockAddr addr, char *buf) |
| 263 | { |
| 264 | assert(addr->family != AF_UNSPEC); |
| 265 | #ifdef IPV6 |
| 266 | if (addr->family == AF_INET6) { |
| 267 | memcpy(buf, (char*) addr->ai, 16); |
| 268 | } else |
| 269 | #endif |
| 270 | if (addr->family == AF_INET) { |
| 271 | struct in_addr a; |
| 272 | a.s_addr = htonl(addr->address); |
| 273 | memcpy(buf, (char*) &a.s_addr, 4); |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | void sk_addr_free(SockAddr addr) |
| 278 | { |
| 279 | sfree(addr); |
| 280 | } |
| 281 | |
| 282 | static Plug sk_tcp_plug(Socket sock, Plug p) |
| 283 | { |
| 284 | Actual_Socket s = (Actual_Socket) sock; |
| 285 | Plug ret = s->plug; |
| 286 | if (p) |
| 287 | s->plug = p; |
| 288 | return ret; |
| 289 | } |
| 290 | |
| 291 | static void sk_tcp_flush(Socket s) |
| 292 | { |
| 293 | /* |
| 294 | * We send data to the socket as soon as we can anyway, |
| 295 | * so we don't need to do anything here. :-) |
| 296 | */ |
| 297 | } |
| 298 | |
| 299 | static void sk_tcp_close(Socket s); |
| 300 | static int sk_tcp_write(Socket s, char *data, int len); |
| 301 | static int sk_tcp_write_oob(Socket s, char *data, int len); |
| 302 | static void sk_tcp_set_private_ptr(Socket s, void *ptr); |
| 303 | static void *sk_tcp_get_private_ptr(Socket s); |
| 304 | static void sk_tcp_set_frozen(Socket s, int is_frozen); |
| 305 | static char *sk_tcp_socket_error(Socket s); |
| 306 | |
| 307 | Socket sk_register(void *sock, Plug plug) |
| 308 | { |
| 309 | static struct socket_function_table fn_table = { |
| 310 | sk_tcp_plug, |
| 311 | sk_tcp_close, |
| 312 | sk_tcp_write, |
| 313 | sk_tcp_write_oob, |
| 314 | sk_tcp_flush, |
| 315 | sk_tcp_set_private_ptr, |
| 316 | sk_tcp_get_private_ptr, |
| 317 | sk_tcp_set_frozen, |
| 318 | sk_tcp_socket_error |
| 319 | }; |
| 320 | |
| 321 | Actual_Socket ret; |
| 322 | |
| 323 | /* |
| 324 | * Create Socket structure. |
| 325 | */ |
| 326 | ret = smalloc(sizeof(struct Socket_tag)); |
| 327 | ret->fn = &fn_table; |
| 328 | ret->error = NULL; |
| 329 | ret->plug = plug; |
| 330 | bufchain_init(&ret->output_data); |
| 331 | ret->writable = 1; /* to start with */ |
| 332 | ret->sending_oob = 0; |
| 333 | ret->frozen = 1; |
| 334 | ret->frozen_readable = 0; |
| 335 | ret->localhost_only = 0; /* unused, but best init anyway */ |
| 336 | ret->pending_error = 0; |
| 337 | ret->oobpending = FALSE; |
| 338 | ret->listener = 0; |
| 339 | |
| 340 | ret->s = (int)sock; |
| 341 | |
| 342 | if (ret->s < 0) { |
| 343 | ret->error = error_string(errno); |
| 344 | return (Socket) ret; |
| 345 | } |
| 346 | |
| 347 | ret->oobinline = 0; |
| 348 | |
| 349 | add234(sktree, ret); |
| 350 | |
| 351 | return (Socket) ret; |
| 352 | } |
| 353 | |
| 354 | Socket sk_new(SockAddr addr, int port, int privport, int oobinline, |
| 355 | int nodelay, Plug plug) |
| 356 | { |
| 357 | static struct socket_function_table fn_table = { |
| 358 | sk_tcp_plug, |
| 359 | sk_tcp_close, |
| 360 | sk_tcp_write, |
| 361 | sk_tcp_write_oob, |
| 362 | sk_tcp_flush, |
| 363 | sk_tcp_set_private_ptr, |
| 364 | sk_tcp_get_private_ptr, |
| 365 | sk_tcp_set_frozen, |
| 366 | sk_tcp_socket_error |
| 367 | }; |
| 368 | |
| 369 | int s; |
| 370 | #ifdef IPV6 |
| 371 | struct sockaddr_in6 a6; |
| 372 | #endif |
| 373 | struct sockaddr_in a; |
| 374 | int err; |
| 375 | Actual_Socket ret; |
| 376 | short localport; |
| 377 | |
| 378 | /* |
| 379 | * Create Socket structure. |
| 380 | */ |
| 381 | ret = smalloc(sizeof(struct Socket_tag)); |
| 382 | ret->fn = &fn_table; |
| 383 | ret->error = NULL; |
| 384 | ret->plug = plug; |
| 385 | bufchain_init(&ret->output_data); |
| 386 | ret->connected = 0; /* to start with */ |
| 387 | ret->writable = 0; /* to start with */ |
| 388 | ret->sending_oob = 0; |
| 389 | ret->frozen = 0; |
| 390 | ret->frozen_readable = 0; |
| 391 | ret->localhost_only = 0; /* unused, but best init anyway */ |
| 392 | ret->pending_error = 0; |
| 393 | ret->oobpending = FALSE; |
| 394 | ret->listener = 0; |
| 395 | |
| 396 | /* |
| 397 | * Open socket. |
| 398 | */ |
| 399 | assert(addr->family != AF_UNSPEC); |
| 400 | s = socket(addr->family, SOCK_STREAM, 0); |
| 401 | ret->s = s; |
| 402 | |
| 403 | if (s < 0) { |
| 404 | ret->error = error_string(errno); |
| 405 | return (Socket) ret; |
| 406 | } |
| 407 | |
| 408 | ret->oobinline = oobinline; |
| 409 | if (oobinline) { |
| 410 | int b = TRUE; |
| 411 | setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b)); |
| 412 | } |
| 413 | |
| 414 | if (nodelay) { |
| 415 | int b = TRUE; |
| 416 | setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b)); |
| 417 | } |
| 418 | |
| 419 | /* |
| 420 | * Bind to local address. |
| 421 | */ |
| 422 | if (privport) |
| 423 | localport = 1023; /* count from 1023 downwards */ |
| 424 | else |
| 425 | localport = 0; /* just use port 0 (ie kernel picks) */ |
| 426 | |
| 427 | /* Loop round trying to bind */ |
| 428 | while (1) { |
| 429 | int retcode; |
| 430 | |
| 431 | #ifdef IPV6 |
| 432 | if (addr->family == AF_INET6) { |
| 433 | memset(&a6, 0, sizeof(a6)); |
| 434 | a6.sin6_family = AF_INET6; |
| 435 | /*a6.sin6_addr = in6addr_any; *//* == 0 */ |
| 436 | a6.sin6_port = htons(localport); |
| 437 | } else |
| 438 | #endif |
| 439 | { |
| 440 | a.sin_family = AF_INET; |
| 441 | a.sin_addr.s_addr = htonl(INADDR_ANY); |
| 442 | a.sin_port = htons(localport); |
| 443 | } |
| 444 | #ifdef IPV6 |
| 445 | retcode = bind(s, (addr->family == AF_INET6 ? |
| 446 | (struct sockaddr *) &a6 : |
| 447 | (struct sockaddr *) &a), |
| 448 | (addr->family == |
| 449 | AF_INET6 ? sizeof(a6) : sizeof(a))); |
| 450 | #else |
| 451 | retcode = bind(s, (struct sockaddr *) &a, sizeof(a)); |
| 452 | #endif |
| 453 | if (retcode >= 0) { |
| 454 | err = 0; |
| 455 | break; /* done */ |
| 456 | } else { |
| 457 | err = errno; |
| 458 | if (err != EADDRINUSE) /* failed, for a bad reason */ |
| 459 | break; |
| 460 | } |
| 461 | |
| 462 | if (localport == 0) |
| 463 | break; /* we're only looping once */ |
| 464 | localport--; |
| 465 | if (localport == 0) |
| 466 | break; /* we might have got to the end */ |
| 467 | } |
| 468 | |
| 469 | if (err) { |
| 470 | ret->error = error_string(err); |
| 471 | return (Socket) ret; |
| 472 | } |
| 473 | |
| 474 | /* |
| 475 | * Connect to remote address. |
| 476 | */ |
| 477 | #ifdef IPV6 |
| 478 | if (addr->family == AF_INET6) { |
| 479 | memset(&a, 0, sizeof(a)); |
| 480 | a6.sin6_family = AF_INET6; |
| 481 | a6.sin6_port = htons((short) port); |
| 482 | a6.sin6_addr = |
| 483 | ((struct sockaddr_in6 *) addr->ai->ai_addr)->sin6_addr; |
| 484 | } else |
| 485 | #endif |
| 486 | { |
| 487 | a.sin_family = AF_INET; |
| 488 | a.sin_addr.s_addr = htonl(addr->address); |
| 489 | a.sin_port = htons((short) port); |
| 490 | } |
| 491 | |
| 492 | if (( |
| 493 | #ifdef IPV6 |
| 494 | connect(s, ((addr->family == AF_INET6) ? |
| 495 | (struct sockaddr *) &a6 : (struct sockaddr *) &a), |
| 496 | (addr->family == AF_INET6) ? sizeof(a6) : sizeof(a)) |
| 497 | #else |
| 498 | connect(s, (struct sockaddr *) &a, sizeof(a)) |
| 499 | #endif |
| 500 | ) < 0) { |
| 501 | /* |
| 502 | * FIXME: We are prepared to receive EWOULDBLOCK here, |
| 503 | * because we might want the connection to be made |
| 504 | * asynchronously; but how do we actually arrange this in |
| 505 | * Unix? I forget. |
| 506 | */ |
| 507 | if ( errno != EWOULDBLOCK ) { |
| 508 | ret->error = error_string(errno); |
| 509 | return (Socket) ret; |
| 510 | } |
| 511 | } else { |
| 512 | /* |
| 513 | * If we _don't_ get EWOULDBLOCK, the connect has completed |
| 514 | * and we should set the socket as connected and writable. |
| 515 | */ |
| 516 | ret->connected = 1; |
| 517 | ret->writable = 1; |
| 518 | } |
| 519 | |
| 520 | add234(sktree, ret); |
| 521 | |
| 522 | return (Socket) ret; |
| 523 | } |
| 524 | |
| 525 | Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only) |
| 526 | { |
| 527 | static struct socket_function_table fn_table = { |
| 528 | sk_tcp_plug, |
| 529 | sk_tcp_close, |
| 530 | sk_tcp_write, |
| 531 | sk_tcp_write_oob, |
| 532 | sk_tcp_flush, |
| 533 | sk_tcp_set_private_ptr, |
| 534 | sk_tcp_get_private_ptr, |
| 535 | sk_tcp_set_frozen, |
| 536 | sk_tcp_socket_error |
| 537 | }; |
| 538 | |
| 539 | int s; |
| 540 | #ifdef IPV6 |
| 541 | struct sockaddr_in6 a6; |
| 542 | #endif |
| 543 | struct sockaddr_in a; |
| 544 | int err; |
| 545 | Actual_Socket ret; |
| 546 | int retcode; |
| 547 | int on = 1; |
| 548 | |
| 549 | /* |
| 550 | * Create Socket structure. |
| 551 | */ |
| 552 | ret = smalloc(sizeof(struct Socket_tag)); |
| 553 | ret->fn = &fn_table; |
| 554 | ret->error = NULL; |
| 555 | ret->plug = plug; |
| 556 | bufchain_init(&ret->output_data); |
| 557 | ret->writable = 0; /* to start with */ |
| 558 | ret->sending_oob = 0; |
| 559 | ret->frozen = 0; |
| 560 | ret->frozen_readable = 0; |
| 561 | ret->localhost_only = local_host_only; |
| 562 | ret->pending_error = 0; |
| 563 | ret->oobpending = FALSE; |
| 564 | ret->listener = 1; |
| 565 | |
| 566 | /* |
| 567 | * Open socket. |
| 568 | */ |
| 569 | s = socket(AF_INET, SOCK_STREAM, 0); |
| 570 | ret->s = s; |
| 571 | |
| 572 | if (s < 0) { |
| 573 | ret->error = error_string(errno); |
| 574 | return (Socket) ret; |
| 575 | } |
| 576 | |
| 577 | ret->oobinline = 0; |
| 578 | |
| 579 | setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on)); |
| 580 | |
| 581 | #ifdef IPV6 |
| 582 | if (addr->family == AF_INET6) { |
| 583 | memset(&a6, 0, sizeof(a6)); |
| 584 | a6.sin6_family = AF_INET6; |
| 585 | /* FIXME: srcaddr is ignored for IPv6, because I (SGT) don't |
| 586 | * know how to do it. :-) */ |
| 587 | if (local_host_only) |
| 588 | a6.sin6_addr = in6addr_loopback; |
| 589 | else |
| 590 | a6.sin6_addr = in6addr_any; |
| 591 | a6.sin6_port = htons(port); |
| 592 | } else |
| 593 | #endif |
| 594 | { |
| 595 | int got_addr = 0; |
| 596 | a.sin_family = AF_INET; |
| 597 | |
| 598 | /* |
| 599 | * Bind to source address. First try an explicitly |
| 600 | * specified one... |
| 601 | */ |
| 602 | if (srcaddr) { |
| 603 | a.sin_addr.s_addr = inet_addr(srcaddr); |
| 604 | if (a.sin_addr.s_addr != INADDR_NONE) { |
| 605 | /* Override localhost_only with specified listen addr. */ |
| 606 | ret->localhost_only = ipv4_is_loopback(a.sin_addr); |
| 607 | got_addr = 1; |
| 608 | } |
| 609 | } |
| 610 | |
| 611 | /* |
| 612 | * ... and failing that, go with one of the standard ones. |
| 613 | */ |
| 614 | if (!got_addr) { |
| 615 | if (local_host_only) |
| 616 | a.sin_addr.s_addr = htonl(INADDR_LOOPBACK); |
| 617 | else |
| 618 | a.sin_addr.s_addr = htonl(INADDR_ANY); |
| 619 | } |
| 620 | |
| 621 | a.sin_port = htons((short)port); |
| 622 | } |
| 623 | #ifdef IPV6 |
| 624 | retcode = bind(s, (addr->family == AF_INET6 ? |
| 625 | (struct sockaddr *) &a6 : |
| 626 | (struct sockaddr *) &a), |
| 627 | (addr->family == |
| 628 | AF_INET6 ? sizeof(a6) : sizeof(a))); |
| 629 | #else |
| 630 | retcode = bind(s, (struct sockaddr *) &a, sizeof(a)); |
| 631 | #endif |
| 632 | if (retcode >= 0) { |
| 633 | err = 0; |
| 634 | } else { |
| 635 | err = errno; |
| 636 | } |
| 637 | |
| 638 | if (err) { |
| 639 | ret->error = error_string(err); |
| 640 | return (Socket) ret; |
| 641 | } |
| 642 | |
| 643 | |
| 644 | if (listen(s, SOMAXCONN) < 0) { |
| 645 | close(s); |
| 646 | ret->error = error_string(errno); |
| 647 | return (Socket) ret; |
| 648 | } |
| 649 | |
| 650 | add234(sktree, ret); |
| 651 | |
| 652 | return (Socket) ret; |
| 653 | } |
| 654 | |
| 655 | static void sk_tcp_close(Socket sock) |
| 656 | { |
| 657 | Actual_Socket s = (Actual_Socket) sock; |
| 658 | |
| 659 | del234(sktree, s); |
| 660 | close(s->s); |
| 661 | sfree(s); |
| 662 | } |
| 663 | |
| 664 | /* |
| 665 | * The function which tries to send on a socket once it's deemed |
| 666 | * writable. |
| 667 | */ |
| 668 | void try_send(Actual_Socket s) |
| 669 | { |
| 670 | while (s->sending_oob || bufchain_size(&s->output_data) > 0) { |
| 671 | int nsent; |
| 672 | int err; |
| 673 | void *data; |
| 674 | int len, urgentflag; |
| 675 | |
| 676 | if (s->sending_oob) { |
| 677 | urgentflag = MSG_OOB; |
| 678 | len = s->sending_oob; |
| 679 | data = &s->oobdata; |
| 680 | } else { |
| 681 | urgentflag = 0; |
| 682 | bufchain_prefix(&s->output_data, &data, &len); |
| 683 | } |
| 684 | nsent = send(s->s, data, len, urgentflag); |
| 685 | noise_ultralight(nsent); |
| 686 | if (nsent <= 0) { |
| 687 | err = (nsent < 0 ? errno : 0); |
| 688 | if (err == EWOULDBLOCK) { |
| 689 | /* |
| 690 | * Perfectly normal: we've sent all we can for the moment. |
| 691 | */ |
| 692 | s->writable = FALSE; |
| 693 | return; |
| 694 | } else if (nsent == 0 || |
| 695 | err == ECONNABORTED || err == ECONNRESET) { |
| 696 | /* |
| 697 | * If send() returns CONNABORTED or CONNRESET, we |
| 698 | * unfortunately can't just call plug_closing(), |
| 699 | * because it's quite likely that we're currently |
| 700 | * _in_ a call from the code we'd be calling back |
| 701 | * to, so we'd have to make half the SSH code |
| 702 | * reentrant. Instead we flag a pending error on |
| 703 | * the socket, to be dealt with (by calling |
| 704 | * plug_closing()) at some suitable future moment. |
| 705 | */ |
| 706 | s->pending_error = err; |
| 707 | return; |
| 708 | } else { |
| 709 | /* We're inside the Unix frontend here, so we know |
| 710 | * that the frontend handle is unnecessary. */ |
| 711 | logevent(NULL, error_string(err)); |
| 712 | fatalbox("%s", error_string(err)); |
| 713 | } |
| 714 | } else { |
| 715 | if (s->sending_oob) { |
| 716 | if (nsent < len) { |
| 717 | memmove(s->oobdata, s->oobdata+nsent, len-nsent); |
| 718 | s->sending_oob = len - nsent; |
| 719 | } else { |
| 720 | s->sending_oob = 0; |
| 721 | } |
| 722 | } else { |
| 723 | bufchain_consume(&s->output_data, nsent); |
| 724 | } |
| 725 | } |
| 726 | } |
| 727 | } |
| 728 | |
| 729 | static int sk_tcp_write(Socket sock, char *buf, int len) |
| 730 | { |
| 731 | Actual_Socket s = (Actual_Socket) sock; |
| 732 | |
| 733 | /* |
| 734 | * Add the data to the buffer list on the socket. |
| 735 | */ |
| 736 | bufchain_add(&s->output_data, buf, len); |
| 737 | |
| 738 | /* |
| 739 | * Now try sending from the start of the buffer list. |
| 740 | */ |
| 741 | if (s->writable) |
| 742 | try_send(s); |
| 743 | |
| 744 | return bufchain_size(&s->output_data); |
| 745 | } |
| 746 | |
| 747 | static int sk_tcp_write_oob(Socket sock, char *buf, int len) |
| 748 | { |
| 749 | Actual_Socket s = (Actual_Socket) sock; |
| 750 | |
| 751 | /* |
| 752 | * Replace the buffer list on the socket with the data. |
| 753 | */ |
| 754 | bufchain_clear(&s->output_data); |
| 755 | assert(len <= sizeof(s->oobdata)); |
| 756 | memcpy(s->oobdata, buf, len); |
| 757 | s->sending_oob = len; |
| 758 | |
| 759 | /* |
| 760 | * Now try sending from the start of the buffer list. |
| 761 | */ |
| 762 | if (s->writable) |
| 763 | try_send(s); |
| 764 | |
| 765 | return s->sending_oob; |
| 766 | } |
| 767 | |
| 768 | int select_result(int fd, int event) |
| 769 | { |
| 770 | int ret; |
| 771 | int err; |
| 772 | char buf[20480]; /* nice big buffer for plenty of speed */ |
| 773 | Actual_Socket s; |
| 774 | u_long atmark; |
| 775 | |
| 776 | /* Find the Socket structure */ |
| 777 | s = find234(sktree, (void *) fd, cmpforsearch); |
| 778 | if (!s) |
| 779 | return 1; /* boggle */ |
| 780 | |
| 781 | noise_ultralight(event); |
| 782 | |
| 783 | switch (event) { |
| 784 | #ifdef FIXME_NONBLOCKING_CONNECTIONS |
| 785 | case FIXME: /* connected */ |
| 786 | s->connected = s->writable = 1; |
| 787 | break; |
| 788 | #endif |
| 789 | case 4: /* exceptional */ |
| 790 | if (!s->oobinline) { |
| 791 | /* |
| 792 | * On a non-oobinline socket, this indicates that we |
| 793 | * can immediately perform an OOB read and get back OOB |
| 794 | * data, which we will send to the back end with |
| 795 | * type==2 (urgent data). |
| 796 | */ |
| 797 | ret = recv(s->s, buf, sizeof(buf), MSG_OOB); |
| 798 | noise_ultralight(ret); |
| 799 | if (ret <= 0) { |
| 800 | char *str = (ret == 0 ? "Internal networking trouble" : |
| 801 | error_string(errno)); |
| 802 | /* We're inside the Unix frontend here, so we know |
| 803 | * that the frontend handle is unnecessary. */ |
| 804 | logevent(NULL, str); |
| 805 | fatalbox("%s", str); |
| 806 | } else { |
| 807 | return plug_receive(s->plug, 2, buf, ret); |
| 808 | } |
| 809 | break; |
| 810 | } |
| 811 | |
| 812 | /* |
| 813 | * If we reach here, this is an oobinline socket, which |
| 814 | * means we should set s->oobpending and then deal with it |
| 815 | * when we get called for the readability event (which |
| 816 | * should also occur). |
| 817 | */ |
| 818 | s->oobpending = TRUE; |
| 819 | break; |
| 820 | case 1: /* readable; also acceptance */ |
| 821 | if (s->listener) { |
| 822 | /* |
| 823 | * On a listening socket, the readability event means a |
| 824 | * connection is ready to be accepted. |
| 825 | */ |
| 826 | struct sockaddr_in isa; |
| 827 | int addrlen = sizeof(struct sockaddr_in); |
| 828 | int t; /* socket of connection */ |
| 829 | |
| 830 | memset(&isa, 0, sizeof(struct sockaddr_in)); |
| 831 | err = 0; |
| 832 | t = accept(s->s,(struct sockaddr *)&isa,&addrlen); |
| 833 | if (t < 0) { |
| 834 | break; |
| 835 | } |
| 836 | |
| 837 | if (s->localhost_only && !ipv4_is_loopback(isa.sin_addr)) { |
| 838 | close(t); /* someone let nonlocal through?! */ |
| 839 | } else if (plug_accepting(s->plug, (void*)t)) { |
| 840 | close(t); /* denied or error */ |
| 841 | } |
| 842 | break; |
| 843 | } |
| 844 | |
| 845 | /* |
| 846 | * If we reach here, this is not a listening socket, so |
| 847 | * readability really means readability. |
| 848 | */ |
| 849 | |
| 850 | /* In the case the socket is still frozen, we don't even bother */ |
| 851 | if (s->frozen) { |
| 852 | s->frozen_readable = 1; |
| 853 | break; |
| 854 | } |
| 855 | |
| 856 | /* |
| 857 | * We have received data on the socket. For an oobinline |
| 858 | * socket, this might be data _before_ an urgent pointer, |
| 859 | * in which case we send it to the back end with type==1 |
| 860 | * (data prior to urgent). |
| 861 | */ |
| 862 | if (s->oobinline && s->oobpending) { |
| 863 | atmark = 1; |
| 864 | if (ioctl(s->s, SIOCATMARK, &atmark) == 0 && atmark) |
| 865 | s->oobpending = FALSE; /* clear this indicator */ |
| 866 | } else |
| 867 | atmark = 1; |
| 868 | |
| 869 | ret = recv(s->s, buf, s->oobpending ? 1 : sizeof(buf), 0); |
| 870 | noise_ultralight(ret); |
| 871 | if (ret < 0) { |
| 872 | if (errno == EWOULDBLOCK) { |
| 873 | break; |
| 874 | } |
| 875 | } |
| 876 | if (ret < 0) { |
| 877 | return plug_closing(s->plug, error_string(errno), errno, 0); |
| 878 | } else if (0 == ret) { |
| 879 | return plug_closing(s->plug, NULL, 0, 0); |
| 880 | } else { |
| 881 | return plug_receive(s->plug, atmark ? 0 : 1, buf, ret); |
| 882 | } |
| 883 | break; |
| 884 | case 2: /* writable */ |
| 885 | { |
| 886 | int bufsize_before, bufsize_after; |
| 887 | s->writable = 1; |
| 888 | bufsize_before = s->sending_oob + bufchain_size(&s->output_data); |
| 889 | try_send(s); |
| 890 | bufsize_after = s->sending_oob + bufchain_size(&s->output_data); |
| 891 | if (bufsize_after < bufsize_before) |
| 892 | plug_sent(s->plug, bufsize_after); |
| 893 | } |
| 894 | break; |
| 895 | } |
| 896 | |
| 897 | return 1; |
| 898 | } |
| 899 | |
| 900 | /* |
| 901 | * Deal with socket errors detected in try_send(). |
| 902 | */ |
| 903 | void net_pending_errors(void) |
| 904 | { |
| 905 | int i; |
| 906 | Actual_Socket s; |
| 907 | |
| 908 | /* |
| 909 | * This might be a fiddly business, because it's just possible |
| 910 | * that handling a pending error on one socket might cause |
| 911 | * others to be closed. (I can't think of any reason this might |
| 912 | * happen in current SSH implementation, but to maintain |
| 913 | * generality of this network layer I'll assume the worst.) |
| 914 | * |
| 915 | * So what we'll do is search the socket list for _one_ socket |
| 916 | * with a pending error, and then handle it, and then search |
| 917 | * the list again _from the beginning_. Repeat until we make a |
| 918 | * pass with no socket errors present. That way we are |
| 919 | * protected against the socket list changing under our feet. |
| 920 | */ |
| 921 | |
| 922 | do { |
| 923 | for (i = 0; (s = index234(sktree, i)) != NULL; i++) { |
| 924 | if (s->pending_error) { |
| 925 | /* |
| 926 | * An error has occurred on this socket. Pass it to the |
| 927 | * plug. |
| 928 | */ |
| 929 | plug_closing(s->plug, error_string(s->pending_error), |
| 930 | s->pending_error, 0); |
| 931 | break; |
| 932 | } |
| 933 | } |
| 934 | } while (s); |
| 935 | } |
| 936 | |
| 937 | /* |
| 938 | * Each socket abstraction contains a `void *' private field in |
| 939 | * which the client can keep state. |
| 940 | */ |
| 941 | static void sk_tcp_set_private_ptr(Socket sock, void *ptr) |
| 942 | { |
| 943 | Actual_Socket s = (Actual_Socket) sock; |
| 944 | s->private_ptr = ptr; |
| 945 | } |
| 946 | |
| 947 | static void *sk_tcp_get_private_ptr(Socket sock) |
| 948 | { |
| 949 | Actual_Socket s = (Actual_Socket) sock; |
| 950 | return s->private_ptr; |
| 951 | } |
| 952 | |
| 953 | /* |
| 954 | * Special error values are returned from sk_namelookup and sk_new |
| 955 | * if there's a problem. These functions extract an error message, |
| 956 | * or return NULL if there's no problem. |
| 957 | */ |
| 958 | char *sk_addr_error(SockAddr addr) |
| 959 | { |
| 960 | return addr->error; |
| 961 | } |
| 962 | static char *sk_tcp_socket_error(Socket sock) |
| 963 | { |
| 964 | Actual_Socket s = (Actual_Socket) sock; |
| 965 | return s->error; |
| 966 | } |
| 967 | |
| 968 | static void sk_tcp_set_frozen(Socket sock, int is_frozen) |
| 969 | { |
| 970 | Actual_Socket s = (Actual_Socket) sock; |
| 971 | if (s->frozen == is_frozen) |
| 972 | return; |
| 973 | s->frozen = is_frozen; |
| 974 | if (!is_frozen && s->frozen_readable) { |
| 975 | char c; |
| 976 | recv(s->s, &c, 1, MSG_PEEK); |
| 977 | } |
| 978 | s->frozen_readable = 0; |
| 979 | } |
| 980 | |
| 981 | /* |
| 982 | * For Unix select()-based frontends: enumerate all sockets |
| 983 | * currently active, and state whether we currently wish to receive |
| 984 | * select events on them for reading, writing and exceptional |
| 985 | * status. |
| 986 | */ |
| 987 | static void set_rwx(Actual_Socket s, int *rwx) |
| 988 | { |
| 989 | int val = 0; |
| 990 | if (s->connected && !s->frozen) |
| 991 | val |= 1 | 4; /* read, except */ |
| 992 | if (bufchain_size(&s->output_data)) |
| 993 | val |= 2; /* write */ |
| 994 | if (s->listener) |
| 995 | val |= 1; /* read == accept */ |
| 996 | *rwx = val; |
| 997 | } |
| 998 | |
| 999 | int first_socket(int *state, int *rwx) |
| 1000 | { |
| 1001 | Actual_Socket s; |
| 1002 | *state = 0; |
| 1003 | s = index234(sktree, (*state)++); |
| 1004 | if (s) |
| 1005 | set_rwx(s, rwx); |
| 1006 | return s ? s->s : -1; |
| 1007 | } |
| 1008 | |
| 1009 | int next_socket(int *state, int *rwx) |
| 1010 | { |
| 1011 | Actual_Socket s = index234(sktree, (*state)++); |
| 1012 | if (s) |
| 1013 | set_rwx(s, rwx); |
| 1014 | return s ? s->s : -1; |
| 1015 | } |
| 1016 | |
| 1017 | int net_service_lookup(char *service) |
| 1018 | { |
| 1019 | struct servent *se; |
| 1020 | se = getservbyname(service, NULL); |
| 1021 | if (se != NULL) |
| 1022 | return ntohs(se->s_port); |
| 1023 | else |
| 1024 | return 0; |
| 1025 | } |