git.distorted.org.uk Git - u/mdw/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 <errno.h>
   8 #include <assert.h>
   9 #include <stdarg.h>
  10 #include <signal.h>
  11 #include <unistd.h>
  12 #include <fcntl.h>
  13 #include <termios.h>
  14 #include <pwd.h>
  15 #include <sys/ioctl.h>
  16
  17 #define PUTTY_DO_GLOBALS               /* actually _define_ globals */
  18 #include "putty.h"
  19 #include "storage.h"
  20 #include "tree234.h"
  21
  22 #define MAX_STDIN_BACKLOG 4096
  23
  24 void fatalbox(char *p, ...)
  25 {
  26     va_list ap;
  27     fprintf(stderr, "FATAL ERROR: ");
  28     va_start(ap, p);
  29     vfprintf(stderr, p, ap);
  30     va_end(ap);
  31     fputc('\n', stderr);
  32     cleanup_exit(1);
  33 }
  34 void modalfatalbox(char *p, ...)
  35 {
  36     va_list ap;
  37     fprintf(stderr, "FATAL ERROR: ");
  38     va_start(ap, p);
  39     vfprintf(stderr, p, ap);
  40     va_end(ap);
  41     fputc('\n', stderr);
  42     cleanup_exit(1);
  43 }
  44 void connection_fatal(void *frontend, char *p, ...)
  45 {
  46     va_list ap;
  47     fprintf(stderr, "FATAL ERROR: ");
  48     va_start(ap, p);
  49     vfprintf(stderr, p, ap);
  50     va_end(ap);
  51     fputc('\n', stderr);
  52     cleanup_exit(1);
  53 }
  54 void cmdline_error(char *p, ...)
  55 {
  56     va_list ap;
  57     fprintf(stderr, "plink: ");
  58     va_start(ap, p);
  59     vfprintf(stderr, p, ap);
  60     va_end(ap);
  61     fputc('\n', stderr);
  62     exit(1);
  63 }
  64
  65 struct termios orig_termios;
  66
  67 static Backend *back;
  68 static void *backhandle;
  69 static Config cfg;
  70
  71 /*
  72  * Default settings that are specific to pterm.
  73  */
  74 char *platform_default_s(const char *name)
  75 {
  76     if (!strcmp(name, "X11Display"))
  77         return dupstr(getenv("DISPLAY"));
  78     if (!strcmp(name, "TermType"))
  79         return dupstr(getenv("TERM"));
  80     if (!strcmp(name, "UserName"))
  81         return get_username();
  82     return NULL;
  83 }
  84
  85 int platform_default_i(const char *name, int def)
  86 {
  87     if (!strcmp(name, "TermWidth") ||
  88         !strcmp(name, "TermHeight")) {
  89         struct winsize size;
  90         if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
  91             return (!strcmp(name, "TermWidth") ? size.ws_col : size.ws_row);
  92     }
  93     return def;
  94 }
  95
  96 FontSpec platform_default_fontspec(const char *name)
  97 {
  98     FontSpec ret;
  99     *ret.name = '\0';
 100     return ret;
 101 }
 102
 103 Filename platform_default_filename(const char *name)
 104 {
 105     Filename ret;
 106     if (!strcmp(name, "LogFileName"))
 107         strcpy(ret.path, "putty.log");
 108     else
 109         *ret.path = '\0';
 110     return ret;
 111 }
 112
 113 char *x_get_default(const char *key)
 114 {
 115     return NULL;                       /* this is a stub */
 116 }
 117 int term_ldisc(Terminal *term, int mode)
 118 {
 119     return FALSE;
 120 }
 121 void ldisc_update(void *frontend, int echo, int edit)
 122 {
 123     /* Update stdin read mode to reflect changes in line discipline. */
 124     struct termios mode;
 125
 126     mode = orig_termios;
 127
 128     if (echo)
 129         mode.c_lflag |= ECHO;
 130     else
 131         mode.c_lflag &= ~ECHO;
 132
 133     if (edit)
 134         mode.c_lflag |= ISIG | ICANON;
 135     else
 136         mode.c_lflag &= ~(ISIG | ICANON);
 137
 138     tcsetattr(0, TCSANOW, &mode);
 139 }
 140
 141 void cleanup_termios(void)
 142 {
 143     tcsetattr(0, TCSANOW, &orig_termios);
 144 }
 145
 146 bufchain stdout_data, stderr_data;
 147
 148 void try_output(int is_stderr)
 149 {
 150     bufchain *chain = (is_stderr ? &stderr_data : &stdout_data);
 151     int fd = (is_stderr ? 2 : 1);
 152     void *senddata;
 153     int sendlen, ret;
 154
 155     if (bufchain_size(chain) == 0)
 156         return;
 157
 158     bufchain_prefix(chain, &senddata, &sendlen);
 159     ret = write(fd, senddata, sendlen);
 160     if (ret > 0)
 161         bufchain_consume(chain, ret);
 162     else if (ret < 0) {
 163         perror(is_stderr ? "stderr: write" : "stdout: write");
 164         exit(1);
 165     }
 166 }
 167
 168 int from_backend(void *frontend_handle, int is_stderr,
 169                  const char *data, int len)
 170 {
 171     int osize, esize;
 172
 173     assert(len > 0);
 174
 175     if (is_stderr) {
 176         bufchain_add(&stderr_data, data, len);
 177         try_output(1);
 178     } else {
 179         bufchain_add(&stdout_data, data, len);
 180         try_output(0);
 181     }
 182
 183     osize = bufchain_size(&stdout_data);
 184     esize = bufchain_size(&stderr_data);
 185
 186     return osize + esize;
 187 }
 188
 189 int signalpipe[2];
 190
 191 void sigwinch(int signum)
 192 {
 193     write(signalpipe[1], "x", 1);
 194 }
 195
 196 /*
 197  * In Plink our selects are synchronous, so these functions are
 198  * empty stubs.
 199  */
 200 int uxsel_input_add(int fd, int rwx) { return 0; }
 201 void uxsel_input_remove(int id) { }
 202
 203 /*
 204  * Short description of parameters.
 205  */
 206 static void usage(void)
 207 {
 208     printf("PuTTY Link: command-line connection utility\n");
 209     printf("%s\n", ver);
 210     printf("Usage: plink [options] [user@]host [command]\n");
 211     printf("       (\"host\" can also be a PuTTY saved session name)\n");
 212     printf("Options:\n");
 213     printf("  -v        show verbose messages\n");
 214     printf("  -load sessname  Load settings from saved session\n");
 215     printf("  -ssh -telnet -rlogin -raw\n");
 216     printf("            force use of a particular protocol (default SSH)\n");
 217     printf("  -P port   connect to specified port\n");
 218     printf("  -l user   connect with specified username\n");
 219     printf("  -m file   read remote command(s) from file\n");
 220     printf("  -batch    disable all interactive prompts\n");
 221     printf("The following options only apply to SSH connections:\n");
 222     printf("  -pw passw login with specified password\n");
 223     printf("  -D listen-port   Dynamic SOCKS-based port forwarding\n");
 224     printf("  -L listen-port:host:port   Forward local port to "
 225            "remote address\n");
 226     printf("  -R listen-port:host:port   Forward remote port to"
 227            " local address\n");
 228     printf("  -X -x     enable / disable X11 forwarding\n");
 229     printf("  -A -a     enable / disable agent forwarding\n");
 230     printf("  -t -T     enable / disable pty allocation\n");
 231     printf("  -1 -2     force use of particular protocol version\n");
 232     printf("  -C        enable compression\n");
 233     printf("  -i key    private key file for authentication\n");
 234     printf("  -s        remote command is an SSH subsystem (SSH-2 only)\n");
 235     exit(1);
 236 }
 237
 238 int main(int argc, char **argv)
 239 {
 240     int sending;
 241     int portnumber = -1;
 242     int *fdlist;
 243     int fd;
 244     int i, fdcount, fdsize, fdstate;
 245     int connopen;
 246     int exitcode;
 247     int errors;
 248     int use_subsystem = 0;
 249     void *ldisc, *logctx;
 250
 251     ssh_get_line = console_get_line;
 252
 253     fdlist = NULL;
 254     fdcount = fdsize = 0;
 255     /*
 256      * Initialise port and protocol to sensible defaults. (These
 257      * will be overridden by more or less anything.)
 258      */
 259     default_protocol = PROT_SSH;
 260     default_port = 22;
 261
 262     flags = FLAG_STDERR;
 263     /*
 264      * Process the command line.
 265      */
 266     do_defaults(NULL, &cfg);
 267     default_protocol = cfg.protocol;
 268     default_port = cfg.port;
 269     errors = 0;
 270     {
 271         /*
 272          * Override the default protocol if PLINK_PROTOCOL is set.
 273          */
 274         char *p = getenv("PLINK_PROTOCOL");
 275         int i;
 276         if (p) {
 277             for (i = 0; backends[i].backend != NULL; i++) {
 278                 if (!strcmp(backends[i].name, p)) {
 279                     default_protocol = cfg.protocol = backends[i].protocol;
 280                     default_port = cfg.port =
 281                         backends[i].backend->default_port;
 282                     break;
 283                 }
 284             }
 285         }
 286     }
 287     while (--argc) {
 288         char *p = *++argv;
 289         if (*p == '-') {
 290             int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
 291                                             1, &cfg);
 292             if (ret == -2) {
 293                 fprintf(stderr,
 294                         "plink: option \"%s\" requires an argument\n", p);
 295                 errors = 1;
 296             } else if (ret == 2) {
 297                 --argc, ++argv;
 298             } else if (ret == 1) {
 299                 continue;
 300             } else if (!strcmp(p, "-batch")) {
 301                 console_batch_mode = 1;
 302             } else if (!strcmp(p, "-s")) {
 303                 /* Save status to write to cfg later. */
 304                 use_subsystem = 1;
 305             } else if (!strcmp(p, "-o")) {
 306                 if (argc <= 1) {
 307                     fprintf(stderr,
 308                             "plink: option \"-o\" requires an argument\n");
 309                     errors = 1;
 310                 } else {
 311                     --argc;
 312                     provide_xrm_string(*++argv);
 313                 }
 314             } else {
 315                 fprintf(stderr, "plink: unknown option \"%s\"\n", p);
 316                 errors = 1;
 317             }
 318         } else if (*p) {
 319             if (!*cfg.host) {
 320                 char *q = p;
 321
 322                 do_defaults(NULL, &cfg);
 323
 324                 /*
 325                  * If the hostname starts with "telnet:", set the
 326                  * protocol to Telnet and process the string as a
 327                  * Telnet URL.
 328                  */
 329                 if (!strncmp(q, "telnet:", 7)) {
 330                     char c;
 331
 332                     q += 7;
 333                     if (q[0] == '/' && q[1] == '/')
 334                         q += 2;
 335                     cfg.protocol = PROT_TELNET;
 336                     p = q;
 337                     while (*p && *p != ':' && *p != '/')
 338                         p++;
 339                     c = *p;
 340                     if (*p)
 341                         *p++ = '\0';
 342                     if (c == ':')
 343                         cfg.port = atoi(p);
 344                     else
 345                         cfg.port = -1;
 346                     strncpy(cfg.host, q, sizeof(cfg.host) - 1);
 347                     cfg.host[sizeof(cfg.host) - 1] = '\0';
 348                 } else {
 349                     char *r;
 350                     /*
 351                      * Before we process the [user@]host string, we
 352                      * first check for the presence of a protocol
 353                      * prefix (a protocol name followed by ",").
 354                      */
 355                     r = strchr(p, ',');
 356                     if (r) {
 357                         int i, j;
 358                         for (i = 0; backends[i].backend != NULL; i++) {
 359                             j = strlen(backends[i].name);
 360                             if (j == r - p &&
 361                                 !memcmp(backends[i].name, p, j)) {
 362                                 default_protocol = cfg.protocol =
 363                                     backends[i].protocol;
 364                                 portnumber =
 365                                     backends[i].backend->default_port;
 366                                 p = r + 1;
 367                                 break;
 368                             }
 369                         }
 370                     }
 371
 372                     /*
 373                      * Three cases. Either (a) there's a nonzero
 374                      * length string followed by an @, in which
 375                      * case that's user and the remainder is host.
 376                      * Or (b) there's only one string, not counting
 377                      * a potential initial @, and it exists in the
 378                      * saved-sessions database. Or (c) only one
 379                      * string and it _doesn't_ exist in the
 380                      * database.
 381                      */
 382                     r = strrchr(p, '@');
 383                     if (r == p)
 384                         p++, r = NULL; /* discount initial @ */
 385                     if (r == NULL) {
 386                         /*
 387                          * One string.
 388                          */
 389                         Config cfg2;
 390                         do_defaults(p, &cfg2);
 391                         if (cfg2.host[0] == '\0') {
 392                             /* No settings for this host; use defaults */
 393                             strncpy(cfg.host, p, sizeof(cfg.host) - 1);
 394                             cfg.host[sizeof(cfg.host) - 1] = '\0';
 395                             cfg.port = default_port;
 396                         } else {
 397                             cfg = cfg2;
 398                             cfg.remote_cmd_ptr = cfg.remote_cmd;
 399                         }
 400                     } else {
 401                         *r++ = '\0';
 402                         strncpy(cfg.username, p, sizeof(cfg.username) - 1);
 403                         cfg.username[sizeof(cfg.username) - 1] = '\0';
 404                         strncpy(cfg.host, r, sizeof(cfg.host) - 1);
 405                         cfg.host[sizeof(cfg.host) - 1] = '\0';
 406                         cfg.port = default_port;
 407                     }
 408                 }
 409             } else {
 410                 char *command;
 411                 int cmdlen, cmdsize;
 412                 cmdlen = cmdsize = 0;
 413                 command = NULL;
 414
 415                 while (argc) {
 416                     while (*p) {
 417                         if (cmdlen >= cmdsize) {
 418                             cmdsize = cmdlen + 512;
 419                             command = sresize(command, cmdsize, char);
 420                         }
 421                         command[cmdlen++]=*p++;
 422                     }
 423                     if (cmdlen >= cmdsize) {
 424                         cmdsize = cmdlen + 512;
 425                         command = sresize(command, cmdsize, char);
 426                     }
 427                     command[cmdlen++]=' '; /* always add trailing space */
 428                     if (--argc) p = *++argv;
 429                 }
 430                 if (cmdlen) command[--cmdlen]='\0';
 431                                        /* change trailing blank to NUL */
 432                 cfg.remote_cmd_ptr = command;
 433                 cfg.remote_cmd_ptr2 = NULL;
 434                 cfg.nopty = TRUE;      /* command => no terminal */
 435
 436                 break;                 /* done with cmdline */
 437             }
 438         }
 439     }
 440
 441     if (errors)
 442         return 1;
 443
 444     if (!*cfg.host) {
 445         usage();
 446     }
 447
 448     /*
 449      * Trim leading whitespace off the hostname if it's there.
 450      */
 451     {
 452         int space = strspn(cfg.host, " \t");
 453         memmove(cfg.host, cfg.host+space, 1+strlen(cfg.host)-space);
 454     }
 455
 456     /* See if host is of the form user@host */
 457     if (cfg.host[0] != '\0') {
 458         char *atsign = strchr(cfg.host, '@');
 459         /* Make sure we're not overflowing the user field */
 460         if (atsign) {
 461             if (atsign - cfg.host < sizeof cfg.username) {
 462                 strncpy(cfg.username, cfg.host, atsign - cfg.host);
 463                 cfg.username[atsign - cfg.host] = '\0';
 464             }
 465             memmove(cfg.host, atsign + 1, 1 + strlen(atsign + 1));
 466         }
 467     }
 468
 469     /*
 470      * Perform command-line overrides on session configuration.
 471      */
 472     cmdline_run_saved(&cfg);
 473
 474     /*
 475      * Apply subsystem status.
 476      */
 477     if (use_subsystem)
 478         cfg.ssh_subsys = TRUE;
 479
 480     /*
 481      * Trim a colon suffix off the hostname if it's there.
 482      */
 483     cfg.host[strcspn(cfg.host, ":")] = '\0';
 484
 485     /*
 486      * Remove any remaining whitespace from the hostname.
 487      */
 488     {
 489         int p1 = 0, p2 = 0;
 490         while (cfg.host[p2] != '\0') {
 491             if (cfg.host[p2] != ' ' && cfg.host[p2] != '\t') {
 492                 cfg.host[p1] = cfg.host[p2];
 493                 p1++;
 494             }
 495             p2++;
 496         }
 497         cfg.host[p1] = '\0';
 498     }
 499
 500     if (!*cfg.remote_cmd_ptr)
 501         flags |= FLAG_INTERACTIVE;
 502
 503     /*
 504      * Select protocol. This is farmed out into a table in a
 505      * separate file to enable an ssh-free variant.
 506      */
 507     {
 508         int i;
 509         back = NULL;
 510         for (i = 0; backends[i].backend != NULL; i++)
 511             if (backends[i].protocol == cfg.protocol) {
 512                 back = backends[i].backend;
 513                 break;
 514             }
 515         if (back == NULL) {
 516             fprintf(stderr,
 517                     "Internal fault: Unsupported protocol found\n");
 518             return 1;
 519         }
 520     }
 521
 522     /*
 523      * Select port.
 524      */
 525     if (portnumber != -1)
 526         cfg.port = portnumber;
 527
 528     /*
 529      * Set up the pipe we'll use to tell us about SIGWINCH.
 530      */
 531     if (pipe(signalpipe) < 0) {
 532         perror("pipe");
 533         exit(1);
 534     }
 535     putty_signal(SIGWINCH, sigwinch);
 536
 537     sk_init();
 538     uxsel_init();
 539
 540     /*
 541      * Start up the connection.
 542      */
 543     logctx = log_init(NULL, &cfg);
 544     console_provide_logctx(logctx);
 545     {
 546         const char *error;
 547         char *realhost;
 548         /* nodelay is only useful if stdin is a terminal device */
 549         int nodelay = cfg.tcp_nodelay && isatty(0);
 550
 551         error = back->init(NULL, &backhandle, &cfg, cfg.host, cfg.port,
 552                            &realhost, nodelay);
 553         if (error) {
 554             fprintf(stderr, "Unable to open connection:\n%s\n", error);
 555             return 1;
 556         }
 557         back->provide_logctx(backhandle, logctx);
 558         ldisc = ldisc_create(&cfg, NULL, back, backhandle, NULL);
 559         sfree(realhost);
 560     }
 561     connopen = 1;
 562
 563     /*
 564      * Set up the initial console mode. We don't care if this call
 565      * fails, because we know we aren't necessarily running in a
 566      * console.
 567      */
 568     tcgetattr(0, &orig_termios);
 569     atexit(cleanup_termios);
 570     ldisc_update(NULL, 1, 1);
 571     sending = FALSE;
 572
 573     while (1) {
 574         fd_set rset, wset, xset;
 575         int maxfd;
 576         int rwx;
 577         int ret;
 578
 579         FD_ZERO(&rset);
 580         FD_ZERO(&wset);
 581         FD_ZERO(&xset);
 582         maxfd = 0;
 583
 584         FD_SET_MAX(signalpipe[0], maxfd, rset);
 585
 586         if (connopen && !sending &&
 587             back->socket(backhandle) != NULL &&
 588             back->sendok(backhandle) &&
 589             back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
 590             /* If we're OK to send, then try to read from stdin. */
 591             FD_SET_MAX(0, maxfd, rset);
 592         }
 593
 594         if (bufchain_size(&stdout_data) > 0) {
 595             /* If we have data for stdout, try to write to stdout. */
 596             FD_SET_MAX(1, maxfd, wset);
 597         }
 598
 599         if (bufchain_size(&stderr_data) > 0) {
 600             /* If we have data for stderr, try to write to stderr. */
 601             FD_SET_MAX(2, maxfd, wset);
 602         }
 603
 604         /* Count the currently active fds. */
 605         i = 0;
 606         for (fd = first_fd(&fdstate, &rwx); fd >= 0;
 607              fd = next_fd(&fdstate, &rwx)) i++;
 608
 609         /* Expand the fdlist buffer if necessary. */
 610         if (i > fdsize) {
 611             fdsize = i + 16;
 612             fdlist = sresize(fdlist, fdsize, int);
 613         }
 614
 615         /*
 616          * Add all currently open fds to the select sets, and store
 617          * them in fdlist as well.
 618          */
 619         fdcount = 0;
 620         for (fd = first_fd(&fdstate, &rwx); fd >= 0;
 621              fd = next_fd(&fdstate, &rwx)) {
 622             fdlist[fdcount++] = fd;
 623             if (rwx & 1)
 624                 FD_SET_MAX(fd, maxfd, rset);
 625             if (rwx & 2)
 626                 FD_SET_MAX(fd, maxfd, wset);
 627             if (rwx & 4)
 628                 FD_SET_MAX(fd, maxfd, xset);
 629         }
 630
 631         do {
 632             ret = select(maxfd, &rset, &wset, &xset, NULL);
 633         } while (ret < 0 && errno == EINTR);
 634
 635         if (ret < 0) {
 636             perror("select");
 637             exit(1);
 638         }
 639
 640         for (i = 0; i < fdcount; i++) {
 641             fd = fdlist[i];
 642             /*
 643              * We must process exceptional notifications before
 644              * ordinary readability ones, or we may go straight
 645              * past the urgent marker.
 646              */
 647             if (FD_ISSET(fd, &xset))
 648                 select_result(fd, 4);
 649             if (FD_ISSET(fd, &rset))
 650                 select_result(fd, 1);
 651             if (FD_ISSET(fd, &wset))
 652                 select_result(fd, 2);
 653         }
 654
 655         if (FD_ISSET(signalpipe[0], &rset)) {
 656             char c[1];
 657             struct winsize size;
 658             read(signalpipe[0], c, 1); /* ignore its value; it'll be `x' */
 659             if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
 660                 back->size(backhandle, size.ws_col, size.ws_row);
 661         }
 662
 663         if (FD_ISSET(0, &rset)) {
 664             char buf[4096];
 665             int ret;
 666
 667             if (connopen && back->socket(backhandle) != NULL) {
 668                 ret = read(0, buf, sizeof(buf));
 669                 if (ret < 0) {
 670                     perror("stdin: read");
 671                     exit(1);
 672                 } else if (ret == 0) {
 673                     back->special(backhandle, TS_EOF);
 674                     sending = FALSE;   /* send nothing further after this */
 675                 } else {
 676                     back->send(backhandle, buf, ret);
 677                 }
 678             }
 679         }
 680
 681         if (FD_ISSET(1, &wset)) {
 682             try_output(0);
 683         }
 684
 685         if (FD_ISSET(2, &wset)) {
 686             try_output(1);
 687         }
 688
 689         if ((!connopen || back->socket(backhandle) == NULL) &&
 690             bufchain_size(&stdout_data) == 0 &&
 691             bufchain_size(&stderr_data) == 0)
 692             break;                     /* we closed the connection */
 693     }
 694     exitcode = back->exitcode(backhandle);
 695     if (exitcode < 0) {
 696         fprintf(stderr, "Remote process exit code unavailable\n");
 697         exitcode = 1;                  /* this is an error condition */
 698     }
 699     cleanup_exit(exitcode);
 700     return exitcode;                   /* shouldn't happen, but placates gcc */
 701 }