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     if (is_stderr) {
 174         bufchain_add(&stderr_data, data, len);
 175         try_output(1);
 176     } else {
 177         bufchain_add(&stdout_data, data, len);
 178         try_output(0);
 179     }
 180
 181     osize = bufchain_size(&stdout_data);
 182     esize = bufchain_size(&stderr_data);
 183
 184     return osize + esize;
 185 }
 186
 187 int signalpipe[2];
 188
 189 void sigwinch(int signum)
 190 {
 191     write(signalpipe[1], "x", 1);
 192 }
 193
 194 /*
 195  * In Plink our selects are synchronous, so these functions are
 196  * empty stubs.
 197  */
 198 int uxsel_input_add(int fd, int rwx) { return 0; }
 199 void uxsel_input_remove(int id) { }
 200
 201 /*
 202  * Short description of parameters.
 203  */
 204 static void usage(void)
 205 {
 206     printf("PuTTY Link: command-line connection utility\n");
 207     printf("%s\n", ver);
 208     printf("Usage: plink [options] [user@]host [command]\n");
 209     printf("       (\"host\" can also be a PuTTY saved session name)\n");
 210     printf("Options:\n");
 211     printf("  -V        print version information\n");
 212     printf("  -v        show verbose messages\n");
 213     printf("  -load sessname  Load settings from saved session\n");
 214     printf("  -ssh -telnet -rlogin -raw\n");
 215     printf("            force use of a particular protocol (default SSH)\n");
 216     printf("  -P port   connect to specified port\n");
 217     printf("  -l user   connect with specified username\n");
 218     printf("  -m file   read remote command(s) from file\n");
 219     printf("  -batch    disable all interactive prompts\n");
 220     printf("The following options only apply to SSH connections:\n");
 221     printf("  -pw passw login with specified password\n");
 222     printf("  -D [listen-IP:]listen-port\n");
 223     printf("            Dynamic SOCKS-based port forwarding\n");
 224     printf("  -L [listen-IP:]listen-port:host:port\n");
 225     printf("            Forward local port to remote address\n");
 226     printf("  -R [listen-IP:]listen-port:host:port\n");
 227     printf("            Forward remote port to 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 static void version(void)
 239 {
 240     printf("plink: %s\n", ver);
 241     exit(1);
 242 }
 243
 244 int main(int argc, char **argv)
 245 {
 246     int sending;
 247     int portnumber = -1;
 248     int *fdlist;
 249     int fd;
 250     int i, fdcount, fdsize, fdstate;
 251     int connopen;
 252     int exitcode;
 253     int errors;
 254     int use_subsystem = 0;
 255     void *ldisc, *logctx;
 256
 257     ssh_get_line = console_get_line;
 258
 259     fdlist = NULL;
 260     fdcount = fdsize = 0;
 261     /*
 262      * Initialise port and protocol to sensible defaults. (These
 263      * will be overridden by more or less anything.)
 264      */
 265     default_protocol = PROT_SSH;
 266     default_port = 22;
 267
 268     flags = FLAG_STDERR;
 269     /*
 270      * Process the command line.
 271      */
 272     do_defaults(NULL, &cfg);
 273     default_protocol = cfg.protocol;
 274     default_port = cfg.port;
 275     errors = 0;
 276     {
 277         /*
 278          * Override the default protocol if PLINK_PROTOCOL is set.
 279          */
 280         char *p = getenv("PLINK_PROTOCOL");
 281         int i;
 282         if (p) {
 283             for (i = 0; backends[i].backend != NULL; i++) {
 284                 if (!strcmp(backends[i].name, p)) {
 285                     default_protocol = cfg.protocol = backends[i].protocol;
 286                     default_port = cfg.port =
 287                         backends[i].backend->default_port;
 288                     break;
 289                 }
 290             }
 291         }
 292     }
 293     while (--argc) {
 294         char *p = *++argv;
 295         if (*p == '-') {
 296             int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
 297                                             1, &cfg);
 298             if (ret == -2) {
 299                 fprintf(stderr,
 300                         "plink: option \"%s\" requires an argument\n", p);
 301                 errors = 1;
 302             } else if (ret == 2) {
 303                 --argc, ++argv;
 304             } else if (ret == 1) {
 305                 continue;
 306             } else if (!strcmp(p, "-batch")) {
 307                 console_batch_mode = 1;
 308             } else if (!strcmp(p, "-s")) {
 309                 /* Save status to write to cfg later. */
 310                 use_subsystem = 1;
 311             } else if (!strcmp(p, "-V")) {
 312                 version();
 313             } else if (!strcmp(p, "-o")) {
 314                 if (argc <= 1) {
 315                     fprintf(stderr,
 316                             "plink: option \"-o\" requires an argument\n");
 317                     errors = 1;
 318                 } else {
 319                     --argc;
 320                     provide_xrm_string(*++argv);
 321                 }
 322             } else {
 323                 fprintf(stderr, "plink: unknown option \"%s\"\n", p);
 324                 errors = 1;
 325             }
 326         } else if (*p) {
 327             if (!*cfg.host) {
 328                 char *q = p;
 329
 330                 do_defaults(NULL, &cfg);
 331
 332                 /*
 333                  * If the hostname starts with "telnet:", set the
 334                  * protocol to Telnet and process the string as a
 335                  * Telnet URL.
 336                  */
 337                 if (!strncmp(q, "telnet:", 7)) {
 338                     char c;
 339
 340                     q += 7;
 341                     if (q[0] == '/' && q[1] == '/')
 342                         q += 2;
 343                     cfg.protocol = PROT_TELNET;
 344                     p = q;
 345                     while (*p && *p != ':' && *p != '/')
 346                         p++;
 347                     c = *p;
 348                     if (*p)
 349                         *p++ = '\0';
 350                     if (c == ':')
 351                         cfg.port = atoi(p);
 352                     else
 353                         cfg.port = -1;
 354                     strncpy(cfg.host, q, sizeof(cfg.host) - 1);
 355                     cfg.host[sizeof(cfg.host) - 1] = '\0';
 356                 } else {
 357                     char *r;
 358                     /*
 359                      * Before we process the [user@]host string, we
 360                      * first check for the presence of a protocol
 361                      * prefix (a protocol name followed by ",").
 362                      */
 363                     r = strchr(p, ',');
 364                     if (r) {
 365                         int i, j;
 366                         for (i = 0; backends[i].backend != NULL; i++) {
 367                             j = strlen(backends[i].name);
 368                             if (j == r - p &&
 369                                 !memcmp(backends[i].name, p, j)) {
 370                                 default_protocol = cfg.protocol =
 371                                     backends[i].protocol;
 372                                 portnumber =
 373                                     backends[i].backend->default_port;
 374                                 p = r + 1;
 375                                 break;
 376                             }
 377                         }
 378                     }
 379
 380                     /*
 381                      * Three cases. Either (a) there's a nonzero
 382                      * length string followed by an @, in which
 383                      * case that's user and the remainder is host.
 384                      * Or (b) there's only one string, not counting
 385                      * a potential initial @, and it exists in the
 386                      * saved-sessions database. Or (c) only one
 387                      * string and it _doesn't_ exist in the
 388                      * database.
 389                      */
 390                     r = strrchr(p, '@');
 391                     if (r == p)
 392                         p++, r = NULL; /* discount initial @ */
 393                     if (r == NULL) {
 394                         /*
 395                          * One string.
 396                          */
 397                         Config cfg2;
 398                         do_defaults(p, &cfg2);
 399                         if (cfg2.host[0] == '\0') {
 400                             /* No settings for this host; use defaults */
 401                             strncpy(cfg.host, p, sizeof(cfg.host) - 1);
 402                             cfg.host[sizeof(cfg.host) - 1] = '\0';
 403                             cfg.port = default_port;
 404                         } else {
 405                             cfg = cfg2;
 406                             cfg.remote_cmd_ptr = cfg.remote_cmd;
 407                         }
 408                     } else {
 409                         *r++ = '\0';
 410                         strncpy(cfg.username, p, sizeof(cfg.username) - 1);
 411                         cfg.username[sizeof(cfg.username) - 1] = '\0';
 412                         strncpy(cfg.host, r, sizeof(cfg.host) - 1);
 413                         cfg.host[sizeof(cfg.host) - 1] = '\0';
 414                         cfg.port = default_port;
 415                     }
 416                 }
 417             } else {
 418                 char *command;
 419                 int cmdlen, cmdsize;
 420                 cmdlen = cmdsize = 0;
 421                 command = NULL;
 422
 423                 while (argc) {
 424                     while (*p) {
 425                         if (cmdlen >= cmdsize) {
 426                             cmdsize = cmdlen + 512;
 427                             command = sresize(command, cmdsize, char);
 428                         }
 429                         command[cmdlen++]=*p++;
 430                     }
 431                     if (cmdlen >= cmdsize) {
 432                         cmdsize = cmdlen + 512;
 433                         command = sresize(command, cmdsize, char);
 434                     }
 435                     command[cmdlen++]=' '; /* always add trailing space */
 436                     if (--argc) p = *++argv;
 437                 }
 438                 if (cmdlen) command[--cmdlen]='\0';
 439                                        /* change trailing blank to NUL */
 440                 cfg.remote_cmd_ptr = command;
 441                 cfg.remote_cmd_ptr2 = NULL;
 442                 cfg.nopty = TRUE;      /* command => no terminal */
 443
 444                 break;                 /* done with cmdline */
 445             }
 446         }
 447     }
 448
 449     if (errors)
 450         return 1;
 451
 452     if (!*cfg.host) {
 453         usage();
 454     }
 455
 456     /*
 457      * Trim leading whitespace off the hostname if it's there.
 458      */
 459     {
 460         int space = strspn(cfg.host, " \t");
 461         memmove(cfg.host, cfg.host+space, 1+strlen(cfg.host)-space);
 462     }
 463
 464     /* See if host is of the form user@host */
 465     if (cfg.host[0] != '\0') {
 466         char *atsign = strchr(cfg.host, '@');
 467         /* Make sure we're not overflowing the user field */
 468         if (atsign) {
 469             if (atsign - cfg.host < sizeof cfg.username) {
 470                 strncpy(cfg.username, cfg.host, atsign - cfg.host);
 471                 cfg.username[atsign - cfg.host] = '\0';
 472             }
 473             memmove(cfg.host, atsign + 1, 1 + strlen(atsign + 1));
 474         }
 475     }
 476
 477     /*
 478      * Perform command-line overrides on session configuration.
 479      */
 480     cmdline_run_saved(&cfg);
 481
 482     /*
 483      * Apply subsystem status.
 484      */
 485     if (use_subsystem)
 486         cfg.ssh_subsys = TRUE;
 487
 488     /*
 489      * Trim a colon suffix off the hostname if it's there.
 490      */
 491     cfg.host[strcspn(cfg.host, ":")] = '\0';
 492
 493     /*
 494      * Remove any remaining whitespace from the hostname.
 495      */
 496     {
 497         int p1 = 0, p2 = 0;
 498         while (cfg.host[p2] != '\0') {
 499             if (cfg.host[p2] != ' ' && cfg.host[p2] != '\t') {
 500                 cfg.host[p1] = cfg.host[p2];
 501                 p1++;
 502             }
 503             p2++;
 504         }
 505         cfg.host[p1] = '\0';
 506     }
 507
 508     if (!*cfg.remote_cmd_ptr)
 509         flags |= FLAG_INTERACTIVE;
 510
 511     /*
 512      * Select protocol. This is farmed out into a table in a
 513      * separate file to enable an ssh-free variant.
 514      */
 515     {
 516         int i;
 517         back = NULL;
 518         for (i = 0; backends[i].backend != NULL; i++)
 519             if (backends[i].protocol == cfg.protocol) {
 520                 back = backends[i].backend;
 521                 break;
 522             }
 523         if (back == NULL) {
 524             fprintf(stderr,
 525                     "Internal fault: Unsupported protocol found\n");
 526             return 1;
 527         }
 528     }
 529
 530     /*
 531      * Select port.
 532      */
 533     if (portnumber != -1)
 534         cfg.port = portnumber;
 535
 536     /*
 537      * Set up the pipe we'll use to tell us about SIGWINCH.
 538      */
 539     if (pipe(signalpipe) < 0) {
 540         perror("pipe");
 541         exit(1);
 542     }
 543     putty_signal(SIGWINCH, sigwinch);
 544
 545     sk_init();
 546     uxsel_init();
 547
 548     /*
 549      * Start up the connection.
 550      */
 551     logctx = log_init(NULL, &cfg);
 552     console_provide_logctx(logctx);
 553     {
 554         const char *error;
 555         char *realhost;
 556         /* nodelay is only useful if stdin is a terminal device */
 557         int nodelay = cfg.tcp_nodelay && isatty(0);
 558
 559         error = back->init(NULL, &backhandle, &cfg, cfg.host, cfg.port,
 560                            &realhost, nodelay, cfg.tcp_keepalives);
 561         if (error) {
 562             fprintf(stderr, "Unable to open connection:\n%s\n", error);
 563             return 1;
 564         }
 565         back->provide_logctx(backhandle, logctx);
 566         ldisc = ldisc_create(&cfg, NULL, back, backhandle, NULL);
 567         sfree(realhost);
 568     }
 569     connopen = 1;
 570
 571     /*
 572      * Set up the initial console mode. We don't care if this call
 573      * fails, because we know we aren't necessarily running in a
 574      * console.
 575      */
 576     tcgetattr(0, &orig_termios);
 577     atexit(cleanup_termios);
 578     ldisc_update(NULL, 1, 1);
 579     sending = FALSE;
 580
 581     while (1) {
 582         fd_set rset, wset, xset;
 583         int maxfd;
 584         int rwx;
 585         int ret;
 586
 587         FD_ZERO(&rset);
 588         FD_ZERO(&wset);
 589         FD_ZERO(&xset);
 590         maxfd = 0;
 591
 592         FD_SET_MAX(signalpipe[0], maxfd, rset);
 593
 594         if (connopen && !sending &&
 595             back->socket(backhandle) != NULL &&
 596             back->sendok(backhandle) &&
 597             back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
 598             /* If we're OK to send, then try to read from stdin. */
 599             FD_SET_MAX(0, maxfd, rset);
 600         }
 601
 602         if (bufchain_size(&stdout_data) > 0) {
 603             /* If we have data for stdout, try to write to stdout. */
 604             FD_SET_MAX(1, maxfd, wset);
 605         }
 606
 607         if (bufchain_size(&stderr_data) > 0) {
 608             /* If we have data for stderr, try to write to stderr. */
 609             FD_SET_MAX(2, maxfd, wset);
 610         }
 611
 612         /* Count the currently active fds. */
 613         i = 0;
 614         for (fd = first_fd(&fdstate, &rwx); fd >= 0;
 615              fd = next_fd(&fdstate, &rwx)) i++;
 616
 617         /* Expand the fdlist buffer if necessary. */
 618         if (i > fdsize) {
 619             fdsize = i + 16;
 620             fdlist = sresize(fdlist, fdsize, int);
 621         }
 622
 623         /*
 624          * Add all currently open fds to the select sets, and store
 625          * them in fdlist as well.
 626          */
 627         fdcount = 0;
 628         for (fd = first_fd(&fdstate, &rwx); fd >= 0;
 629              fd = next_fd(&fdstate, &rwx)) {
 630             fdlist[fdcount++] = fd;
 631             if (rwx & 1)
 632                 FD_SET_MAX(fd, maxfd, rset);
 633             if (rwx & 2)
 634                 FD_SET_MAX(fd, maxfd, wset);
 635             if (rwx & 4)
 636                 FD_SET_MAX(fd, maxfd, xset);
 637         }
 638
 639         do {
 640             ret = select(maxfd, &rset, &wset, &xset, NULL);
 641         } while (ret < 0 && errno == EINTR);
 642
 643         if (ret < 0) {
 644             perror("select");
 645             exit(1);
 646         }
 647
 648         for (i = 0; i < fdcount; i++) {
 649             fd = fdlist[i];
 650             /*
 651              * We must process exceptional notifications before
 652              * ordinary readability ones, or we may go straight
 653              * past the urgent marker.
 654              */
 655             if (FD_ISSET(fd, &xset))
 656                 select_result(fd, 4);
 657             if (FD_ISSET(fd, &rset))
 658                 select_result(fd, 1);
 659             if (FD_ISSET(fd, &wset))
 660                 select_result(fd, 2);
 661         }
 662
 663         if (FD_ISSET(signalpipe[0], &rset)) {
 664             char c[1];
 665             struct winsize size;
 666             read(signalpipe[0], c, 1); /* ignore its value; it'll be `x' */
 667             if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
 668                 back->size(backhandle, size.ws_col, size.ws_row);
 669         }
 670
 671         if (FD_ISSET(0, &rset)) {
 672             char buf[4096];
 673             int ret;
 674
 675             if (connopen && back->socket(backhandle) != NULL) {
 676                 ret = read(0, buf, sizeof(buf));
 677                 if (ret < 0) {
 678                     perror("stdin: read");
 679                     exit(1);
 680                 } else if (ret == 0) {
 681                     back->special(backhandle, TS_EOF);
 682                     sending = FALSE;   /* send nothing further after this */
 683                 } else {
 684                     back->send(backhandle, buf, ret);
 685                 }
 686             }
 687         }
 688
 689         if (FD_ISSET(1, &wset)) {
 690             try_output(0);
 691         }
 692
 693         if (FD_ISSET(2, &wset)) {
 694             try_output(1);
 695         }
 696
 697         if ((!connopen || back->socket(backhandle) == NULL) &&
 698             bufchain_size(&stdout_data) == 0 &&
 699             bufchain_size(&stderr_data) == 0)
 700             break;                     /* we closed the connection */
 701     }
 702     exitcode = back->exitcode(backhandle);
 703     if (exitcode < 0) {
 704         fprintf(stderr, "Remote process exit code unavailable\n");
 705         exitcode = 1;                  /* this is an error condition */
 706     }
 707     cleanup_exit(exitcode);
 708     return exitcode;                   /* shouldn't happen, but placates gcc */
 709 }