| 1 | /* |
| 2 | * Rlogin backend. |
| 3 | */ |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <stdlib.h> |
| 7 | #include <limits.h> |
| 8 | #include <ctype.h> |
| 9 | |
| 10 | #include "putty.h" |
| 11 | |
| 12 | #ifndef FALSE |
| 13 | #define FALSE 0 |
| 14 | #endif |
| 15 | #ifndef TRUE |
| 16 | #define TRUE 1 |
| 17 | #endif |
| 18 | |
| 19 | #define RLOGIN_MAX_BACKLOG 4096 |
| 20 | |
| 21 | typedef struct rlogin_tag { |
| 22 | const struct plug_function_table *fn; |
| 23 | /* the above field _must_ be first in the structure */ |
| 24 | |
| 25 | Socket s; |
| 26 | int closed_on_socket_error; |
| 27 | int bufsize; |
| 28 | int firstbyte; |
| 29 | int cansize; |
| 30 | int term_width, term_height; |
| 31 | void *frontend; |
| 32 | |
| 33 | Conf *conf; |
| 34 | |
| 35 | /* In case we need to read a username from the terminal before starting */ |
| 36 | prompts_t *prompt; |
| 37 | } *Rlogin; |
| 38 | |
| 39 | static void rlogin_size(void *handle, int width, int height); |
| 40 | |
| 41 | static void c_write(Rlogin rlogin, char *buf, int len) |
| 42 | { |
| 43 | int backlog = from_backend(rlogin->frontend, 0, buf, len); |
| 44 | sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG); |
| 45 | } |
| 46 | |
| 47 | static void rlogin_log(Plug plug, int type, SockAddr addr, int port, |
| 48 | const char *error_msg, int error_code) |
| 49 | { |
| 50 | Rlogin rlogin = (Rlogin) plug; |
| 51 | char addrbuf[256], *msg; |
| 52 | |
| 53 | sk_getaddr(addr, addrbuf, lenof(addrbuf)); |
| 54 | |
| 55 | if (type == 0) |
| 56 | msg = dupprintf("Connecting to %s port %d", addrbuf, port); |
| 57 | else |
| 58 | msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg); |
| 59 | |
| 60 | logevent(rlogin->frontend, msg); |
| 61 | sfree(msg); |
| 62 | } |
| 63 | |
| 64 | static int rlogin_closing(Plug plug, const char *error_msg, int error_code, |
| 65 | int calling_back) |
| 66 | { |
| 67 | Rlogin rlogin = (Rlogin) plug; |
| 68 | |
| 69 | /* |
| 70 | * We don't implement independent EOF in each direction for Telnet |
| 71 | * connections; as soon as we get word that the remote side has |
| 72 | * sent us EOF, we wind up the whole connection. |
| 73 | */ |
| 74 | |
| 75 | if (rlogin->s) { |
| 76 | sk_close(rlogin->s); |
| 77 | rlogin->s = NULL; |
| 78 | if (error_msg) |
| 79 | rlogin->closed_on_socket_error = TRUE; |
| 80 | notify_remote_exit(rlogin->frontend); |
| 81 | } |
| 82 | if (error_msg) { |
| 83 | /* A socket error has occurred. */ |
| 84 | logevent(rlogin->frontend, error_msg); |
| 85 | connection_fatal(rlogin->frontend, "%s", error_msg); |
| 86 | } /* Otherwise, the remote side closed the connection normally. */ |
| 87 | return 0; |
| 88 | } |
| 89 | |
| 90 | static int rlogin_receive(Plug plug, int urgent, char *data, int len) |
| 91 | { |
| 92 | Rlogin rlogin = (Rlogin) plug; |
| 93 | if (urgent == 2) { |
| 94 | char c; |
| 95 | |
| 96 | c = *data++; |
| 97 | len--; |
| 98 | if (c == '\x80') { |
| 99 | rlogin->cansize = 1; |
| 100 | rlogin_size(rlogin, rlogin->term_width, rlogin->term_height); |
| 101 | } |
| 102 | /* |
| 103 | * We should flush everything (aka Telnet SYNCH) if we see |
| 104 | * 0x02, and we should turn off and on _local_ flow control |
| 105 | * on 0x10 and 0x20 respectively. I'm not convinced it's |
| 106 | * worth it... |
| 107 | */ |
| 108 | } else { |
| 109 | /* |
| 110 | * Main rlogin protocol. This is really simple: the first |
| 111 | * byte is expected to be NULL and is ignored, and the rest |
| 112 | * is printed. |
| 113 | */ |
| 114 | if (rlogin->firstbyte) { |
| 115 | if (data[0] == '\0') { |
| 116 | data++; |
| 117 | len--; |
| 118 | } |
| 119 | rlogin->firstbyte = 0; |
| 120 | } |
| 121 | if (len > 0) |
| 122 | c_write(rlogin, data, len); |
| 123 | } |
| 124 | return 1; |
| 125 | } |
| 126 | |
| 127 | static void rlogin_sent(Plug plug, int bufsize) |
| 128 | { |
| 129 | Rlogin rlogin = (Rlogin) plug; |
| 130 | rlogin->bufsize = bufsize; |
| 131 | } |
| 132 | |
| 133 | static void rlogin_startup(Rlogin rlogin, const char *ruser) |
| 134 | { |
| 135 | char z = 0; |
| 136 | char *p; |
| 137 | |
| 138 | sk_write(rlogin->s, &z, 1); |
| 139 | p = conf_get_str(rlogin->conf, CONF_localusername); |
| 140 | sk_write(rlogin->s, p, strlen(p)); |
| 141 | sk_write(rlogin->s, &z, 1); |
| 142 | sk_write(rlogin->s, ruser, strlen(ruser)); |
| 143 | sk_write(rlogin->s, &z, 1); |
| 144 | p = conf_get_str(rlogin->conf, CONF_termtype); |
| 145 | sk_write(rlogin->s, p, strlen(p)); |
| 146 | sk_write(rlogin->s, "/", 1); |
| 147 | p = conf_get_str(rlogin->conf, CONF_termspeed); |
| 148 | sk_write(rlogin->s, p, strspn(p, "0123456789")); |
| 149 | rlogin->bufsize = sk_write(rlogin->s, &z, 1); |
| 150 | |
| 151 | rlogin->prompt = NULL; |
| 152 | } |
| 153 | |
| 154 | /* |
| 155 | * Called to set up the rlogin connection. |
| 156 | * |
| 157 | * Returns an error message, or NULL on success. |
| 158 | * |
| 159 | * Also places the canonical host name into `realhost'. It must be |
| 160 | * freed by the caller. |
| 161 | */ |
| 162 | static const char *rlogin_init(void *frontend_handle, void **backend_handle, |
| 163 | Conf *conf, |
| 164 | char *host, int port, char **realhost, |
| 165 | int nodelay, int keepalive) |
| 166 | { |
| 167 | static const struct plug_function_table fn_table = { |
| 168 | rlogin_log, |
| 169 | rlogin_closing, |
| 170 | rlogin_receive, |
| 171 | rlogin_sent |
| 172 | }; |
| 173 | SockAddr addr; |
| 174 | const char *err; |
| 175 | Rlogin rlogin; |
| 176 | char *ruser; |
| 177 | int addressfamily; |
| 178 | char *loghost; |
| 179 | |
| 180 | rlogin = snew(struct rlogin_tag); |
| 181 | rlogin->fn = &fn_table; |
| 182 | rlogin->s = NULL; |
| 183 | rlogin->closed_on_socket_error = FALSE; |
| 184 | rlogin->frontend = frontend_handle; |
| 185 | rlogin->term_width = conf_get_int(conf, CONF_width); |
| 186 | rlogin->term_height = conf_get_int(conf, CONF_height); |
| 187 | rlogin->firstbyte = 1; |
| 188 | rlogin->cansize = 0; |
| 189 | rlogin->prompt = NULL; |
| 190 | rlogin->conf = conf_copy(conf); |
| 191 | *backend_handle = rlogin; |
| 192 | |
| 193 | addressfamily = conf_get_int(conf, CONF_addressfamily); |
| 194 | /* |
| 195 | * Try to find host. |
| 196 | */ |
| 197 | { |
| 198 | char *buf; |
| 199 | buf = dupprintf("Looking up host \"%s\"%s", host, |
| 200 | (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" : |
| 201 | (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : |
| 202 | ""))); |
| 203 | logevent(rlogin->frontend, buf); |
| 204 | sfree(buf); |
| 205 | } |
| 206 | addr = name_lookup(host, port, realhost, conf, addressfamily); |
| 207 | if ((err = sk_addr_error(addr)) != NULL) { |
| 208 | sk_addr_free(addr); |
| 209 | return err; |
| 210 | } |
| 211 | |
| 212 | if (port < 0) |
| 213 | port = 513; /* default rlogin port */ |
| 214 | |
| 215 | /* |
| 216 | * Open socket. |
| 217 | */ |
| 218 | rlogin->s = new_connection(addr, *realhost, port, 1, 0, |
| 219 | nodelay, keepalive, (Plug) rlogin, conf); |
| 220 | if ((err = sk_socket_error(rlogin->s)) != NULL) |
| 221 | return err; |
| 222 | |
| 223 | loghost = conf_get_str(conf, CONF_loghost); |
| 224 | if (*loghost) { |
| 225 | char *colon; |
| 226 | |
| 227 | sfree(*realhost); |
| 228 | *realhost = dupstr(loghost); |
| 229 | colon = strrchr(*realhost, ':'); |
| 230 | if (colon) { |
| 231 | /* |
| 232 | * FIXME: if we ever update this aspect of ssh.c for |
| 233 | * IPv6 literal management, this should change in line |
| 234 | * with it. |
| 235 | */ |
| 236 | *colon++ = '\0'; |
| 237 | } |
| 238 | } |
| 239 | |
| 240 | /* |
| 241 | * Send local username, remote username, terminal type and |
| 242 | * terminal speed - unless we don't have the remote username yet, |
| 243 | * in which case we prompt for it and may end up deferring doing |
| 244 | * anything else until the local prompt mechanism returns. |
| 245 | */ |
| 246 | if ((ruser = get_remote_username(conf)) != NULL) { |
| 247 | rlogin_startup(rlogin, ruser); |
| 248 | sfree(ruser); |
| 249 | } else { |
| 250 | int ret; |
| 251 | |
| 252 | rlogin->prompt = new_prompts(rlogin->frontend); |
| 253 | rlogin->prompt->to_server = TRUE; |
| 254 | rlogin->prompt->name = dupstr("Rlogin login name"); |
| 255 | add_prompt(rlogin->prompt, dupstr("rlogin username: "), TRUE); |
| 256 | ret = get_userpass_input(rlogin->prompt, NULL, 0); |
| 257 | if (ret >= 0) { |
| 258 | rlogin_startup(rlogin, rlogin->prompt->prompts[0]->result); |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | return NULL; |
| 263 | } |
| 264 | |
| 265 | static void rlogin_free(void *handle) |
| 266 | { |
| 267 | Rlogin rlogin = (Rlogin) handle; |
| 268 | |
| 269 | if (rlogin->prompt) |
| 270 | free_prompts(rlogin->prompt); |
| 271 | if (rlogin->s) |
| 272 | sk_close(rlogin->s); |
| 273 | conf_free(rlogin->conf); |
| 274 | sfree(rlogin); |
| 275 | } |
| 276 | |
| 277 | /* |
| 278 | * Stub routine (we don't have any need to reconfigure this backend). |
| 279 | */ |
| 280 | static void rlogin_reconfig(void *handle, Conf *conf) |
| 281 | { |
| 282 | } |
| 283 | |
| 284 | /* |
| 285 | * Called to send data down the rlogin connection. |
| 286 | */ |
| 287 | static int rlogin_send(void *handle, char *buf, int len) |
| 288 | { |
| 289 | Rlogin rlogin = (Rlogin) handle; |
| 290 | |
| 291 | if (rlogin->s == NULL) |
| 292 | return 0; |
| 293 | |
| 294 | if (rlogin->prompt) { |
| 295 | /* |
| 296 | * We're still prompting for a username, and aren't talking |
| 297 | * directly to the network connection yet. |
| 298 | */ |
| 299 | int ret = get_userpass_input(rlogin->prompt, |
| 300 | (unsigned char *)buf, len); |
| 301 | if (ret >= 0) { |
| 302 | rlogin_startup(rlogin, rlogin->prompt->prompts[0]->result); |
| 303 | /* that nulls out rlogin->prompt, so then we'll start sending |
| 304 | * data down the wire in the obvious way */ |
| 305 | } |
| 306 | } else { |
| 307 | rlogin->bufsize = sk_write(rlogin->s, buf, len); |
| 308 | } |
| 309 | |
| 310 | return rlogin->bufsize; |
| 311 | } |
| 312 | |
| 313 | /* |
| 314 | * Called to query the current socket sendability status. |
| 315 | */ |
| 316 | static int rlogin_sendbuffer(void *handle) |
| 317 | { |
| 318 | Rlogin rlogin = (Rlogin) handle; |
| 319 | return rlogin->bufsize; |
| 320 | } |
| 321 | |
| 322 | /* |
| 323 | * Called to set the size of the window |
| 324 | */ |
| 325 | static void rlogin_size(void *handle, int width, int height) |
| 326 | { |
| 327 | Rlogin rlogin = (Rlogin) handle; |
| 328 | char b[12] = { '\xFF', '\xFF', 0x73, 0x73, 0, 0, 0, 0, 0, 0, 0, 0 }; |
| 329 | |
| 330 | rlogin->term_width = width; |
| 331 | rlogin->term_height = height; |
| 332 | |
| 333 | if (rlogin->s == NULL || !rlogin->cansize) |
| 334 | return; |
| 335 | |
| 336 | b[6] = rlogin->term_width >> 8; |
| 337 | b[7] = rlogin->term_width & 0xFF; |
| 338 | b[4] = rlogin->term_height >> 8; |
| 339 | b[5] = rlogin->term_height & 0xFF; |
| 340 | rlogin->bufsize = sk_write(rlogin->s, b, 12); |
| 341 | return; |
| 342 | } |
| 343 | |
| 344 | /* |
| 345 | * Send rlogin special codes. |
| 346 | */ |
| 347 | static void rlogin_special(void *handle, Telnet_Special code) |
| 348 | { |
| 349 | /* Do nothing! */ |
| 350 | return; |
| 351 | } |
| 352 | |
| 353 | /* |
| 354 | * Return a list of the special codes that make sense in this |
| 355 | * protocol. |
| 356 | */ |
| 357 | static const struct telnet_special *rlogin_get_specials(void *handle) |
| 358 | { |
| 359 | return NULL; |
| 360 | } |
| 361 | |
| 362 | static int rlogin_connected(void *handle) |
| 363 | { |
| 364 | Rlogin rlogin = (Rlogin) handle; |
| 365 | return rlogin->s != NULL; |
| 366 | } |
| 367 | |
| 368 | static int rlogin_sendok(void *handle) |
| 369 | { |
| 370 | /* Rlogin rlogin = (Rlogin) handle; */ |
| 371 | return 1; |
| 372 | } |
| 373 | |
| 374 | static void rlogin_unthrottle(void *handle, int backlog) |
| 375 | { |
| 376 | Rlogin rlogin = (Rlogin) handle; |
| 377 | sk_set_frozen(rlogin->s, backlog > RLOGIN_MAX_BACKLOG); |
| 378 | } |
| 379 | |
| 380 | static int rlogin_ldisc(void *handle, int option) |
| 381 | { |
| 382 | /* Rlogin rlogin = (Rlogin) handle; */ |
| 383 | return 0; |
| 384 | } |
| 385 | |
| 386 | static void rlogin_provide_ldisc(void *handle, void *ldisc) |
| 387 | { |
| 388 | /* This is a stub. */ |
| 389 | } |
| 390 | |
| 391 | static void rlogin_provide_logctx(void *handle, void *logctx) |
| 392 | { |
| 393 | /* This is a stub. */ |
| 394 | } |
| 395 | |
| 396 | static int rlogin_exitcode(void *handle) |
| 397 | { |
| 398 | Rlogin rlogin = (Rlogin) handle; |
| 399 | if (rlogin->s != NULL) |
| 400 | return -1; /* still connected */ |
| 401 | else if (rlogin->closed_on_socket_error) |
| 402 | return INT_MAX; /* a socket error counts as an unclean exit */ |
| 403 | else |
| 404 | /* If we ever implement RSH, we'll probably need to do this properly */ |
| 405 | return 0; |
| 406 | } |
| 407 | |
| 408 | /* |
| 409 | * cfg_info for rlogin does nothing at all. |
| 410 | */ |
| 411 | static int rlogin_cfg_info(void *handle) |
| 412 | { |
| 413 | return 0; |
| 414 | } |
| 415 | |
| 416 | Backend rlogin_backend = { |
| 417 | rlogin_init, |
| 418 | rlogin_free, |
| 419 | rlogin_reconfig, |
| 420 | rlogin_send, |
| 421 | rlogin_sendbuffer, |
| 422 | rlogin_size, |
| 423 | rlogin_special, |
| 424 | rlogin_get_specials, |
| 425 | rlogin_connected, |
| 426 | rlogin_exitcode, |
| 427 | rlogin_sendok, |
| 428 | rlogin_ldisc, |
| 429 | rlogin_provide_ldisc, |
| 430 | rlogin_provide_logctx, |
| 431 | rlogin_unthrottle, |
| 432 | rlogin_cfg_info, |
| 433 | "rlogin", |
| 434 | PROT_RLOGIN, |
| 435 | 513 |
| 436 | }; |