mdw@git.distorted.org.uk Git - sgt/putty/blob - unix/uxplink.c

   1 /*
   2  * PLink - a command-line (stdin/stdout) variant of PuTTY.
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <assert.h>
   8 #include <stdarg.h>
   9 #include <unistd.h>
  10 #include <fcntl.h>
  11 #include <termios.h>
  12 #include <pwd.h>
  13 #include <sys/ioctl.h>
  14
  15 /* More helpful version of the FD_SET macro, to also handle maxfd. */
  16 #define FD_SET_MAX(fd, max, set) do { \
  17     FD_SET(fd, &set); \
  18     if (max < fd + 1) max = fd + 1; \
  19 } while (0)
  20
  21 #define PUTTY_DO_GLOBALS               /* actually _define_ globals */
  22 #include "putty.h"
  23 #include "storage.h"
  24 #include "tree234.h"
  25
  26 #define MAX_STDIN_BACKLOG 4096
  27
  28 void fatalbox(char *p, ...)
  29 {
  30     va_list ap;
  31     fprintf(stderr, "FATAL ERROR: ");
  32     va_start(ap, p);
  33     vfprintf(stderr, p, ap);
  34     va_end(ap);
  35     fputc('\n', stderr);
  36     cleanup_exit(1);
  37 }
  38 void modalfatalbox(char *p, ...)
  39 {
  40     va_list ap;
  41     fprintf(stderr, "FATAL ERROR: ");
  42     va_start(ap, p);
  43     vfprintf(stderr, p, ap);
  44     va_end(ap);
  45     fputc('\n', stderr);
  46     cleanup_exit(1);
  47 }
  48 void connection_fatal(void *frontend, char *p, ...)
  49 {
  50     va_list ap;
  51     fprintf(stderr, "FATAL ERROR: ");
  52     va_start(ap, p);
  53     vfprintf(stderr, p, ap);
  54     va_end(ap);
  55     fputc('\n', stderr);
  56     cleanup_exit(1);
  57 }
  58 void cmdline_error(char *p, ...)
  59 {
  60     va_list ap;
  61     fprintf(stderr, "plink: ");
  62     va_start(ap, p);
  63     vfprintf(stderr, p, ap);
  64     va_end(ap);
  65     fputc('\n', stderr);
  66     exit(1);
  67 }
  68
  69 struct termios orig_termios;
  70
  71 static Backend *back;
  72 static void *backhandle;
  73
  74 /*
  75  * Default settings that are specific to pterm.
  76  */
  77 char *platform_default_s(char *name)
  78 {
  79     if (!strcmp(name, "X11Display"))
  80         return getenv("DISPLAY");
  81     if (!strcmp(name, "TermType"))
  82         return getenv("TERM");
  83     if (!strcmp(name, "UserName")) {
  84         /*
  85          * Remote login username will default to the local username.
  86          */
  87         struct passwd *p;
  88         uid_t uid = getuid();
  89         char *user, *ret = NULL;
  90
  91         /*
  92          * First, find who we think we are using getlogin. If this
  93          * agrees with our uid, we'll go along with it. This should
  94          * allow sharing of uids between several login names whilst
  95          * coping correctly with people who have su'ed.
  96          */
  97         user = getlogin();
  98         setpwent();
  99         if (user)
 100             p = getpwnam(user);
 101         else
 102             p = NULL;
 103         if (p && p->pw_uid == uid) {
 104             /*
 105              * The result of getlogin() really does correspond to
 106              * our uid. Fine.
 107              */
 108             ret = user;
 109         } else {
 110             /*
 111              * If that didn't work, for whatever reason, we'll do
 112              * the simpler version: look up our uid in the password
 113              * file and map it straight to a name.
 114              */
 115             p = getpwuid(uid);
 116             ret = p->pw_name;
 117         }
 118         endpwent();
 119
 120         return ret;
 121     }
 122     return NULL;
 123 }
 124
 125 int platform_default_i(char *name, int def)
 126 {
 127     if (!strcmp(name, "TermWidth") ||
 128         !strcmp(name, "TermHeight")) {
 129         struct winsize size;
 130         if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
 131             return (!strcmp(name, "TermWidth") ? size.ws_col : size.ws_row);
 132     }
 133     return def;
 134 }
 135
 136 char *x_get_default(char *key)
 137 {
 138     return NULL;                       /* this is a stub */
 139 }
 140 int term_ldisc(Terminal *term, int mode)
 141 {
 142     return FALSE;
 143 }
 144 void ldisc_update(void *frontend, int echo, int edit)
 145 {
 146     /* Update stdin read mode to reflect changes in line discipline. */
 147     struct termios mode;
 148
 149     mode = orig_termios;
 150
 151     if (echo)
 152         mode.c_lflag |= ECHO;
 153     else
 154         mode.c_lflag &= ~ECHO;
 155
 156     if (edit)
 157         mode.c_lflag |= ISIG | ICANON;
 158     else
 159         mode.c_lflag &= ~(ISIG | ICANON);
 160
 161     tcsetattr(0, TCSANOW, &mode);
 162 }
 163
 164 void cleanup_termios(void)
 165 {
 166     tcsetattr(0, TCSANOW, &orig_termios);
 167 }
 168
 169 bufchain stdout_data, stderr_data;
 170
 171 void try_output(int is_stderr)
 172 {
 173     bufchain *chain = (is_stderr ? &stderr_data : &stdout_data);
 174     int fd = (is_stderr ? 2 : 1);
 175     void *senddata;
 176     int sendlen, ret;
 177
 178     if (bufchain_size(chain) == 0)
 179         return;
 180
 181     bufchain_prefix(chain, &senddata, &sendlen);
 182     ret = write(fd, senddata, sendlen);
 183     if (ret > 0)
 184         bufchain_consume(chain, ret);
 185     else if (ret < 0) {
 186         perror(is_stderr ? "stderr: write" : "stdout: write");
 187         exit(1);
 188     }
 189 }
 190
 191 int from_backend(void *frontend_handle, int is_stderr, char *data, int len)
 192 {
 193     int osize, esize;
 194
 195     assert(len > 0);
 196
 197     if (is_stderr) {
 198         bufchain_add(&stderr_data, data, len);
 199         try_output(1);
 200     } else {
 201         bufchain_add(&stdout_data, data, len);
 202         try_output(0);
 203     }
 204
 205     osize = bufchain_size(&stdout_data);
 206     esize = bufchain_size(&stderr_data);
 207
 208     return osize + esize;
 209 }
 210
 211 /*
 212  * Short description of parameters.
 213  */
 214 static void usage(void)
 215 {
 216     printf("PuTTY Link: command-line connection utility\n");
 217     printf("%s\n", ver);
 218     printf("Usage: plink [options] [user@]host [command]\n");
 219     printf("       (\"host\" can also be a PuTTY saved session name)\n");
 220     printf("Options:\n");
 221     printf("  -v        show verbose messages\n");
 222     printf("  -load sessname  Load settings from saved session\n");
 223     printf("  -ssh -telnet -rlogin -raw\n");
 224     printf("            force use of a particular protocol (default SSH)\n");
 225     printf("  -P port   connect to specified port\n");
 226     printf("  -l user   connect with specified username\n");
 227     printf("  -m file   read remote command(s) from file\n");
 228     printf("  -batch    disable all interactive prompts\n");
 229     printf("The following options only apply to SSH connections:\n");
 230     printf("  -pw passw login with specified password\n");
 231     printf("  -L listen-port:host:port   Forward local port to "
 232            "remote address\n");
 233     printf("  -R listen-port:host:port   Forward remote port to"
 234            " local address\n");
 235     printf("  -X -x     enable / disable X11 forwarding\n");
 236     printf("  -A -a     enable / disable agent forwarding\n");
 237     printf("  -t -T     enable / disable pty allocation\n");
 238     printf("  -1 -2     force use of particular protocol version\n");
 239     printf("  -C        enable compression\n");
 240     printf("  -i key    private key file for authentication\n");
 241     exit(1);
 242 }
 243
 244 int main(int argc, char **argv)
 245 {
 246     int sending;
 247     int portnumber = -1;
 248     int *sklist;
 249     int socket;
 250     int i, skcount, sksize, socketstate;
 251     int connopen;
 252     int exitcode;
 253     int errors;
 254     void *ldisc;
 255
 256     ssh_get_line = console_get_line;
 257
 258     sklist = NULL;
 259     skcount = sksize = 0;
 260     /*
 261      * Initialise port and protocol to sensible defaults. (These
 262      * will be overridden by more or less anything.)
 263      */
 264     default_protocol = PROT_SSH;
 265     default_port = 22;
 266
 267     flags = FLAG_STDERR;
 268     /*
 269      * Process the command line.
 270      */
 271     do_defaults(NULL, &cfg);
 272     default_protocol = cfg.protocol;
 273     default_port = cfg.port;
 274     errors = 0;
 275     {
 276         /*
 277          * Override the default protocol if PLINK_PROTOCOL is set.
 278          */
 279         char *p = getenv("PLINK_PROTOCOL");
 280         int i;
 281         if (p) {
 282             for (i = 0; backends[i].backend != NULL; i++) {
 283                 if (!strcmp(backends[i].name, p)) {
 284                     default_protocol = cfg.protocol = backends[i].protocol;
 285                     default_port = cfg.port =
 286                         backends[i].backend->default_port;
 287                     break;
 288                 }
 289             }
 290         }
 291     }
 292     while (--argc) {
 293         char *p = *++argv;
 294         if (*p == '-') {
 295             int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL), 1);
 296             if (ret == -2) {
 297                 fprintf(stderr,
 298                         "plink: option \"%s\" requires an argument\n", p);
 299                 errors = 1;
 300             } else if (ret == 2) {
 301                 --argc, ++argv;
 302             } else if (ret == 1) {
 303                 continue;
 304             } else if (!strcmp(p, "-batch")) {
 305                 console_batch_mode = 1;
 306             } else if (!strcmp(p, "-o")) {
 307                 if (argc <= 1) {
 308                     fprintf(stderr,
 309                             "plink: option \"-o\" requires an argument\n");
 310                     errors = 1;
 311                 } else {
 312                     --argc;
 313                     provide_xrm_string(*++argv);
 314                 }
 315             } else {
 316                 fprintf(stderr, "plink: unknown option \"%s\"\n", p);
 317                 errors = 1;
 318             }
 319         } else if (*p) {
 320             if (!*cfg.host) {
 321                 char *q = p;
 322
 323                 do_defaults(NULL, &cfg);
 324
 325                 /*
 326                  * If the hostname starts with "telnet:", set the
 327                  * protocol to Telnet and process the string as a
 328                  * Telnet URL.
 329                  */
 330                 if (!strncmp(q, "telnet:", 7)) {
 331                     char c;
 332
 333                     q += 7;
 334                     if (q[0] == '/' && q[1] == '/')
 335                         q += 2;
 336                     cfg.protocol = PROT_TELNET;
 337                     p = q;
 338                     while (*p && *p != ':' && *p != '/')
 339                         p++;
 340                     c = *p;
 341                     if (*p)
 342                         *p++ = '\0';
 343                     if (c == ':')
 344                         cfg.port = atoi(p);
 345                     else
 346                         cfg.port = -1;
 347                     strncpy(cfg.host, q, sizeof(cfg.host) - 1);
 348                     cfg.host[sizeof(cfg.host) - 1] = '\0';
 349                 } else {
 350                     char *r;
 351                     /*
 352                      * Before we process the [user@]host string, we
 353                      * first check for the presence of a protocol
 354                      * prefix (a protocol name followed by ",").
 355                      */
 356                     r = strchr(p, ',');
 357                     if (r) {
 358                         int i, j;
 359                         for (i = 0; backends[i].backend != NULL; i++) {
 360                             j = strlen(backends[i].name);
 361                             if (j == r - p &&
 362                                 !memcmp(backends[i].name, p, j)) {
 363                                 default_protocol = cfg.protocol =
 364                                     backends[i].protocol;
 365                                 portnumber =
 366                                     backends[i].backend->default_port;
 367                                 p = r + 1;
 368                                 break;
 369                             }
 370                         }
 371                     }
 372
 373                     /*
 374                      * Three cases. Either (a) there's a nonzero
 375                      * length string followed by an @, in which
 376                      * case that's user and the remainder is host.
 377                      * Or (b) there's only one string, not counting
 378                      * a potential initial @, and it exists in the
 379                      * saved-sessions database. Or (c) only one
 380                      * string and it _doesn't_ exist in the
 381                      * database.
 382                      */
 383                     r = strrchr(p, '@');
 384                     if (r == p)
 385                         p++, r = NULL; /* discount initial @ */
 386                     if (r == NULL) {
 387                         /*
 388                          * One string.
 389                          */
 390                         Config cfg2;
 391                         do_defaults(p, &cfg2);
 392                         if (cfg2.host[0] == '\0') {
 393                             /* No settings for this host; use defaults */
 394                             strncpy(cfg.host, p, sizeof(cfg.host) - 1);
 395                             cfg.host[sizeof(cfg.host) - 1] = '\0';
 396                             cfg.port = default_port;
 397                         } else {
 398                             cfg = cfg2;
 399                             cfg.remote_cmd_ptr = cfg.remote_cmd;
 400                         }
 401                     } else {
 402                         *r++ = '\0';
 403                         strncpy(cfg.username, p, sizeof(cfg.username) - 1);
 404                         cfg.username[sizeof(cfg.username) - 1] = '\0';
 405                         strncpy(cfg.host, r, sizeof(cfg.host) - 1);
 406                         cfg.host[sizeof(cfg.host) - 1] = '\0';
 407                         cfg.port = default_port;
 408                     }
 409                 }
 410             } else {
 411                 char *command;
 412                 int cmdlen, cmdsize;
 413                 cmdlen = cmdsize = 0;
 414                 command = NULL;
 415
 416                 while (argc) {
 417                     while (*p) {
 418                         if (cmdlen >= cmdsize) {
 419                             cmdsize = cmdlen + 512;
 420                             command = srealloc(command, cmdsize);
 421                         }
 422                         command[cmdlen++]=*p++;
 423                     }
 424                     if (cmdlen >= cmdsize) {
 425                         cmdsize = cmdlen + 512;
 426                         command = srealloc(command, cmdsize);
 427                     }
 428                     command[cmdlen++]=' '; /* always add trailing space */
 429                     if (--argc) p = *++argv;
 430                 }
 431                 if (cmdlen) command[--cmdlen]='\0';
 432                                        /* change trailing blank to NUL */
 433                 cfg.remote_cmd_ptr = command;
 434                 cfg.remote_cmd_ptr2 = NULL;
 435                 cfg.nopty = TRUE;      /* command => no terminal */
 436
 437                 break;                 /* done with cmdline */
 438             }
 439         }
 440     }
 441
 442     if (errors)
 443         return 1;
 444
 445     if (!*cfg.host) {
 446         usage();
 447     }
 448
 449     /*
 450      * Trim leading whitespace off the hostname if it's there.
 451      */
 452     {
 453         int space = strspn(cfg.host, " \t");
 454         memmove(cfg.host, cfg.host+space, 1+strlen(cfg.host)-space);
 455     }
 456
 457     /* See if host is of the form user@host */
 458     if (cfg.host[0] != '\0') {
 459         char *atsign = strchr(cfg.host, '@');
 460         /* Make sure we're not overflowing the user field */
 461         if (atsign) {
 462             if (atsign - cfg.host < sizeof cfg.username) {
 463                 strncpy(cfg.username, cfg.host, atsign - cfg.host);
 464                 cfg.username[atsign - cfg.host] = '\0';
 465             }
 466             memmove(cfg.host, atsign + 1, 1 + strlen(atsign + 1));
 467         }
 468     }
 469
 470     /*
 471      * Perform command-line overrides on session configuration.
 472      */
 473     cmdline_run_saved();
 474
 475     /*
 476      * Trim a colon suffix off the hostname if it's there.
 477      */
 478     cfg.host[strcspn(cfg.host, ":")] = '\0';
 479
 480     /*
 481      * Remove any remaining whitespace from the hostname.
 482      */
 483     {
 484         int p1 = 0, p2 = 0;
 485         while (cfg.host[p2] != '\0') {
 486             if (cfg.host[p2] != ' ' && cfg.host[p2] != '\t') {
 487                 cfg.host[p1] = cfg.host[p2];
 488                 p1++;
 489             }
 490             p2++;
 491         }
 492         cfg.host[p1] = '\0';
 493     }
 494
 495     if (!*cfg.remote_cmd_ptr)
 496         flags |= FLAG_INTERACTIVE;
 497
 498     /*
 499      * Select protocol. This is farmed out into a table in a
 500      * separate file to enable an ssh-free variant.
 501      */
 502     {
 503         int i;
 504         back = NULL;
 505         for (i = 0; backends[i].backend != NULL; i++)
 506             if (backends[i].protocol == cfg.protocol) {
 507                 back = backends[i].backend;
 508                 break;
 509             }
 510         if (back == NULL) {
 511             fprintf(stderr,
 512                     "Internal fault: Unsupported protocol found\n");
 513             return 1;
 514         }
 515     }
 516
 517     /*
 518      * Select port.
 519      */
 520     if (portnumber != -1)
 521         cfg.port = portnumber;
 522
 523     sk_init();
 524
 525     /*
 526      * Start up the connection.
 527      */
 528     logctx = log_init(NULL);
 529     {
 530         char *error;
 531         char *realhost;
 532         /* nodelay is only useful if stdin is a terminal device */
 533         int nodelay = cfg.tcp_nodelay && isatty(0);
 534
 535         error = back->init(NULL, &backhandle, cfg.host, cfg.port,
 536                            &realhost, nodelay);
 537         if (error) {
 538             fprintf(stderr, "Unable to open connection:\n%s\n", error);
 539             return 1;
 540         }
 541         back->provide_logctx(backhandle, logctx);
 542         ldisc = ldisc_create(&cfg, NULL, back, backhandle, NULL);
 543         sfree(realhost);
 544     }
 545     connopen = 1;
 546
 547     /*
 548      * Set up the initial console mode. We don't care if this call
 549      * fails, because we know we aren't necessarily running in a
 550      * console.
 551      */
 552     tcgetattr(0, &orig_termios);
 553     atexit(cleanup_termios);
 554     ldisc_update(NULL, 1, 1);
 555     sending = FALSE;
 556
 557     while (1) {
 558         fd_set rset, wset, xset;
 559         int maxfd;
 560         int rwx;
 561         int ret;
 562
 563         FD_ZERO(&rset);
 564         FD_ZERO(&wset);
 565         FD_ZERO(&xset);
 566         maxfd = 0;
 567
 568         if (connopen && !sending &&
 569             back->socket(backhandle) != NULL &&
 570             back->sendok(backhandle) &&
 571             back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
 572             /* If we're OK to send, then try to read from stdin. */
 573             FD_SET_MAX(0, maxfd, rset);
 574         }
 575
 576         if (bufchain_size(&stdout_data) > 0) {
 577             /* If we have data for stdout, try to write to stdout. */
 578             FD_SET_MAX(1, maxfd, wset);
 579         }
 580
 581         if (bufchain_size(&stderr_data) > 0) {
 582             /* If we have data for stderr, try to write to stderr. */
 583             FD_SET_MAX(2, maxfd, wset);
 584         }
 585
 586         /* Count the currently active sockets. */
 587         i = 0;
 588         for (socket = first_socket(&socketstate, &rwx); socket >= 0;
 589              socket = next_socket(&socketstate, &rwx)) i++;
 590
 591         /* Expand the sklist buffer if necessary. */
 592         if (i > sksize) {
 593             sksize = i + 16;
 594             sklist = srealloc(sklist, sksize * sizeof(*sklist));
 595         }
 596
 597         /*
 598          * Add all currently open sockets to the select sets, and
 599          * store them in sklist as well.
 600          */
 601         skcount = 0;
 602         for (socket = first_socket(&socketstate, &rwx); socket >= 0;
 603              socket = next_socket(&socketstate, &rwx)) {
 604             sklist[skcount++] = socket;
 605             if (rwx & 1)
 606                 FD_SET_MAX(socket, maxfd, rset);
 607             if (rwx & 2)
 608                 FD_SET_MAX(socket, maxfd, wset);
 609             if (rwx & 4)
 610                 FD_SET_MAX(socket, maxfd, xset);
 611         }
 612
 613         ret = select(maxfd, &rset, &wset, &xset, NULL);
 614
 615         if (ret < 0) {
 616             perror("select");
 617             exit(1);
 618         }
 619
 620         for (i = 0; i < skcount; i++) {
 621             socket = sklist[i];
 622             /*
 623              * We must process exceptional notifications before
 624              * ordinary readability ones, or we may go straight
 625              * past the urgent marker.
 626              */
 627             if (FD_ISSET(socket, &xset))
 628                 select_result(socket, 4);
 629             if (FD_ISSET(socket, &rset))
 630                 select_result(socket, 1);
 631             if (FD_ISSET(socket, &wset))
 632                 select_result(socket, 2);
 633         }
 634
 635         if (FD_ISSET(0, &rset)) {
 636             char buf[4096];
 637             int ret;
 638
 639             if (connopen && back->socket(backhandle) != NULL) {
 640                 ret = read(0, buf, sizeof(buf));
 641                 if (ret < 0) {
 642                     perror("stdin: read");
 643                     exit(1);
 644                 } else if (ret == 0) {
 645                     back->special(backhandle, TS_EOF);
 646                     sending = FALSE;   /* send nothing further after this */
 647                 } else {
 648                     back->send(backhandle, buf, ret);
 649                 }
 650             }
 651         }
 652
 653         if (FD_ISSET(1, &wset)) {
 654             try_output(0);
 655         }
 656
 657         if (FD_ISSET(2, &wset)) {
 658             try_output(1);
 659         }
 660
 661         if ((!connopen || back->socket(backhandle) == NULL) &&
 662             bufchain_size(&stdout_data) == 0 &&
 663             bufchain_size(&stderr_data) == 0)
 664             break;                     /* we closed the connection */
 665     }
 666     exitcode = back->exitcode(backhandle);
 667     if (exitcode < 0) {
 668         fprintf(stderr, "Remote process exit code unavailable\n");
 669         exitcode = 1;                  /* this is an error condition */
 670     }
 671     cleanup_exit(exitcode);
 672     return exitcode;                   /* shouldn't happen, but placates gcc */
 673 }