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 /* More helpful version of the FD_SET macro, to also handle maxfd. */
  18 #define FD_SET_MAX(fd, max, set) do { \
  19     FD_SET(fd, &set); \
  20     if (max < fd + 1) max = fd + 1; \
  21 } while (0)
  22
  23 #define PUTTY_DO_GLOBALS               /* actually _define_ globals */
  24 #include "putty.h"
  25 #include "storage.h"
  26 #include "tree234.h"
  27
  28 #define MAX_STDIN_BACKLOG 4096
  29
  30 void fatalbox(char *p, ...)
  31 {
  32     va_list ap;
  33     fprintf(stderr, "FATAL ERROR: ");
  34     va_start(ap, p);
  35     vfprintf(stderr, p, ap);
  36     va_end(ap);
  37     fputc('\n', stderr);
  38     cleanup_exit(1);
  39 }
  40 void modalfatalbox(char *p, ...)
  41 {
  42     va_list ap;
  43     fprintf(stderr, "FATAL ERROR: ");
  44     va_start(ap, p);
  45     vfprintf(stderr, p, ap);
  46     va_end(ap);
  47     fputc('\n', stderr);
  48     cleanup_exit(1);
  49 }
  50 void connection_fatal(void *frontend, char *p, ...)
  51 {
  52     va_list ap;
  53     fprintf(stderr, "FATAL ERROR: ");
  54     va_start(ap, p);
  55     vfprintf(stderr, p, ap);
  56     va_end(ap);
  57     fputc('\n', stderr);
  58     cleanup_exit(1);
  59 }
  60 void cmdline_error(char *p, ...)
  61 {
  62     va_list ap;
  63     fprintf(stderr, "plink: ");
  64     va_start(ap, p);
  65     vfprintf(stderr, p, ap);
  66     va_end(ap);
  67     fputc('\n', stderr);
  68     exit(1);
  69 }
  70
  71 struct termios orig_termios;
  72
  73 static Backend *back;
  74 static void *backhandle;
  75
  76 /*
  77  * Default settings that are specific to pterm.
  78  */
  79 char *platform_default_s(char *name)
  80 {
  81     if (!strcmp(name, "X11Display"))
  82         return getenv("DISPLAY");
  83     if (!strcmp(name, "TermType"))
  84         return getenv("TERM");
  85     if (!strcmp(name, "UserName")) {
  86         /*
  87          * Remote login username will default to the local username.
  88          */
  89         struct passwd *p;
  90         uid_t uid = getuid();
  91         char *user, *ret = NULL;
  92
  93         /*
  94          * First, find who we think we are using getlogin. If this
  95          * agrees with our uid, we'll go along with it. This should
  96          * allow sharing of uids between several login names whilst
  97          * coping correctly with people who have su'ed.
  98          */
  99         user = getlogin();
 100         setpwent();
 101         if (user)
 102             p = getpwnam(user);
 103         else
 104             p = NULL;
 105         if (p && p->pw_uid == uid) {
 106             /*
 107              * The result of getlogin() really does correspond to
 108              * our uid. Fine.
 109              */
 110             ret = user;
 111         } else {
 112             /*
 113              * If that didn't work, for whatever reason, we'll do
 114              * the simpler version: look up our uid in the password
 115              * file and map it straight to a name.
 116              */
 117             p = getpwuid(uid);
 118             ret = p->pw_name;
 119         }
 120         endpwent();
 121
 122         return ret;
 123     }
 124     return NULL;
 125 }
 126
 127 int platform_default_i(char *name, int def)
 128 {
 129     if (!strcmp(name, "TermWidth") ||
 130         !strcmp(name, "TermHeight")) {
 131         struct winsize size;
 132         if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
 133             return (!strcmp(name, "TermWidth") ? size.ws_col : size.ws_row);
 134     }
 135     return def;
 136 }
 137
 138 char *x_get_default(char *key)
 139 {
 140     return NULL;                       /* this is a stub */
 141 }
 142 int term_ldisc(Terminal *term, int mode)
 143 {
 144     return FALSE;
 145 }
 146 void ldisc_update(void *frontend, int echo, int edit)
 147 {
 148     /* Update stdin read mode to reflect changes in line discipline. */
 149     struct termios mode;
 150
 151     mode = orig_termios;
 152
 153     if (echo)
 154         mode.c_lflag |= ECHO;
 155     else
 156         mode.c_lflag &= ~ECHO;
 157
 158     if (edit)
 159         mode.c_lflag |= ISIG | ICANON;
 160     else
 161         mode.c_lflag &= ~(ISIG | ICANON);
 162
 163     tcsetattr(0, TCSANOW, &mode);
 164 }
 165
 166 void cleanup_termios(void)
 167 {
 168     tcsetattr(0, TCSANOW, &orig_termios);
 169 }
 170
 171 bufchain stdout_data, stderr_data;
 172
 173 void try_output(int is_stderr)
 174 {
 175     bufchain *chain = (is_stderr ? &stderr_data : &stdout_data);
 176     int fd = (is_stderr ? 2 : 1);
 177     void *senddata;
 178     int sendlen, ret;
 179
 180     if (bufchain_size(chain) == 0)
 181         return;
 182
 183     bufchain_prefix(chain, &senddata, &sendlen);
 184     ret = write(fd, senddata, sendlen);
 185     if (ret > 0)
 186         bufchain_consume(chain, ret);
 187     else if (ret < 0) {
 188         perror(is_stderr ? "stderr: write" : "stdout: write");
 189         exit(1);
 190     }
 191 }
 192
 193 int from_backend(void *frontend_handle, int is_stderr, char *data, int len)
 194 {
 195     int osize, esize;
 196
 197     assert(len > 0);
 198
 199     if (is_stderr) {
 200         bufchain_add(&stderr_data, data, len);
 201         try_output(1);
 202     } else {
 203         bufchain_add(&stdout_data, data, len);
 204         try_output(0);
 205     }
 206
 207     osize = bufchain_size(&stdout_data);
 208     esize = bufchain_size(&stderr_data);
 209
 210     return osize + esize;
 211 }
 212
 213 int signalpipe[2];
 214
 215 void sigwinch(int signum)
 216 {
 217     write(signalpipe[1], "x", 1);
 218 }
 219
 220 /*
 221  * Short description of parameters.
 222  */
 223 static void usage(void)
 224 {
 225     printf("PuTTY Link: command-line connection utility\n");
 226     printf("%s\n", ver);
 227     printf("Usage: plink [options] [user@]host [command]\n");
 228     printf("       (\"host\" can also be a PuTTY saved session name)\n");
 229     printf("Options:\n");
 230     printf("  -v        show verbose messages\n");
 231     printf("  -load sessname  Load settings from saved session\n");
 232     printf("  -ssh -telnet -rlogin -raw\n");
 233     printf("            force use of a particular protocol (default SSH)\n");
 234     printf("  -P port   connect to specified port\n");
 235     printf("  -l user   connect with specified username\n");
 236     printf("  -m file   read remote command(s) from file\n");
 237     printf("  -batch    disable all interactive prompts\n");
 238     printf("The following options only apply to SSH connections:\n");
 239     printf("  -pw passw login with specified password\n");
 240     printf("  -L listen-port:host:port   Forward local port to "
 241            "remote address\n");
 242     printf("  -R listen-port:host:port   Forward remote port to"
 243            " local address\n");
 244     printf("  -X -x     enable / disable X11 forwarding\n");
 245     printf("  -A -a     enable / disable agent forwarding\n");
 246     printf("  -t -T     enable / disable pty allocation\n");
 247     printf("  -1 -2     force use of particular protocol version\n");
 248     printf("  -C        enable compression\n");
 249     printf("  -i key    private key file for authentication\n");
 250     exit(1);
 251 }
 252
 253 int main(int argc, char **argv)
 254 {
 255     int sending;
 256     int portnumber = -1;
 257     int *sklist;
 258     int socket;
 259     int i, skcount, sksize, socketstate;
 260     int connopen;
 261     int exitcode;
 262     int errors;
 263     void *ldisc;
 264
 265     ssh_get_line = console_get_line;
 266
 267     sklist = NULL;
 268     skcount = sksize = 0;
 269     /*
 270      * Initialise port and protocol to sensible defaults. (These
 271      * will be overridden by more or less anything.)
 272      */
 273     default_protocol = PROT_SSH;
 274     default_port = 22;
 275
 276     flags = FLAG_STDERR;
 277     /*
 278      * Process the command line.
 279      */
 280     do_defaults(NULL, &cfg);
 281     default_protocol = cfg.protocol;
 282     default_port = cfg.port;
 283     errors = 0;
 284     {
 285         /*
 286          * Override the default protocol if PLINK_PROTOCOL is set.
 287          */
 288         char *p = getenv("PLINK_PROTOCOL");
 289         int i;
 290         if (p) {
 291             for (i = 0; backends[i].backend != NULL; i++) {
 292                 if (!strcmp(backends[i].name, p)) {
 293                     default_protocol = cfg.protocol = backends[i].protocol;
 294                     default_port = cfg.port =
 295                         backends[i].backend->default_port;
 296                     break;
 297                 }
 298             }
 299         }
 300     }
 301     while (--argc) {
 302         char *p = *++argv;
 303         if (*p == '-') {
 304             int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
 305                                             1, &cfg);
 306             if (ret == -2) {
 307                 fprintf(stderr,
 308                         "plink: option \"%s\" requires an argument\n", p);
 309                 errors = 1;
 310             } else if (ret == 2) {
 311                 --argc, ++argv;
 312             } else if (ret == 1) {
 313                 continue;
 314             } else if (!strcmp(p, "-batch")) {
 315                 console_batch_mode = 1;
 316             } else if (!strcmp(p, "-o")) {
 317                 if (argc <= 1) {
 318                     fprintf(stderr,
 319                             "plink: option \"-o\" requires an argument\n");
 320                     errors = 1;
 321                 } else {
 322                     --argc;
 323                     provide_xrm_string(*++argv);
 324                 }
 325             } else {
 326                 fprintf(stderr, "plink: unknown option \"%s\"\n", p);
 327                 errors = 1;
 328             }
 329         } else if (*p) {
 330             if (!*cfg.host) {
 331                 char *q = p;
 332
 333                 do_defaults(NULL, &cfg);
 334
 335                 /*
 336                  * If the hostname starts with "telnet:", set the
 337                  * protocol to Telnet and process the string as a
 338                  * Telnet URL.
 339                  */
 340                 if (!strncmp(q, "telnet:", 7)) {
 341                     char c;
 342
 343                     q += 7;
 344                     if (q[0] == '/' && q[1] == '/')
 345                         q += 2;
 346                     cfg.protocol = PROT_TELNET;
 347                     p = q;
 348                     while (*p && *p != ':' && *p != '/')
 349                         p++;
 350                     c = *p;
 351                     if (*p)
 352                         *p++ = '\0';
 353                     if (c == ':')
 354                         cfg.port = atoi(p);
 355                     else
 356                         cfg.port = -1;
 357                     strncpy(cfg.host, q, sizeof(cfg.host) - 1);
 358                     cfg.host[sizeof(cfg.host) - 1] = '\0';
 359                 } else {
 360                     char *r;
 361                     /*
 362                      * Before we process the [user@]host string, we
 363                      * first check for the presence of a protocol
 364                      * prefix (a protocol name followed by ",").
 365                      */
 366                     r = strchr(p, ',');
 367                     if (r) {
 368                         int i, j;
 369                         for (i = 0; backends[i].backend != NULL; i++) {
 370                             j = strlen(backends[i].name);
 371                             if (j == r - p &&
 372                                 !memcmp(backends[i].name, p, j)) {
 373                                 default_protocol = cfg.protocol =
 374                                     backends[i].protocol;
 375                                 portnumber =
 376                                     backends[i].backend->default_port;
 377                                 p = r + 1;
 378                                 break;
 379                             }
 380                         }
 381                     }
 382
 383                     /*
 384                      * Three cases. Either (a) there's a nonzero
 385                      * length string followed by an @, in which
 386                      * case that's user and the remainder is host.
 387                      * Or (b) there's only one string, not counting
 388                      * a potential initial @, and it exists in the
 389                      * saved-sessions database. Or (c) only one
 390                      * string and it _doesn't_ exist in the
 391                      * database.
 392                      */
 393                     r = strrchr(p, '@');
 394                     if (r == p)
 395                         p++, r = NULL; /* discount initial @ */
 396                     if (r == NULL) {
 397                         /*
 398                          * One string.
 399                          */
 400                         Config cfg2;
 401                         do_defaults(p, &cfg2);
 402                         if (cfg2.host[0] == '\0') {
 403                             /* No settings for this host; use defaults */
 404                             strncpy(cfg.host, p, sizeof(cfg.host) - 1);
 405                             cfg.host[sizeof(cfg.host) - 1] = '\0';
 406                             cfg.port = default_port;
 407                         } else {
 408                             cfg = cfg2;
 409                             cfg.remote_cmd_ptr = cfg.remote_cmd;
 410                         }
 411                     } else {
 412                         *r++ = '\0';
 413                         strncpy(cfg.username, p, sizeof(cfg.username) - 1);
 414                         cfg.username[sizeof(cfg.username) - 1] = '\0';
 415                         strncpy(cfg.host, r, sizeof(cfg.host) - 1);
 416                         cfg.host[sizeof(cfg.host) - 1] = '\0';
 417                         cfg.port = default_port;
 418                     }
 419                 }
 420             } else {
 421                 char *command;
 422                 int cmdlen, cmdsize;
 423                 cmdlen = cmdsize = 0;
 424                 command = NULL;
 425
 426                 while (argc) {
 427                     while (*p) {
 428                         if (cmdlen >= cmdsize) {
 429                             cmdsize = cmdlen + 512;
 430                             command = srealloc(command, cmdsize);
 431                         }
 432                         command[cmdlen++]=*p++;
 433                     }
 434                     if (cmdlen >= cmdsize) {
 435                         cmdsize = cmdlen + 512;
 436                         command = srealloc(command, cmdsize);
 437                     }
 438                     command[cmdlen++]=' '; /* always add trailing space */
 439                     if (--argc) p = *++argv;
 440                 }
 441                 if (cmdlen) command[--cmdlen]='\0';
 442                                        /* change trailing blank to NUL */
 443                 cfg.remote_cmd_ptr = command;
 444                 cfg.remote_cmd_ptr2 = NULL;
 445                 cfg.nopty = TRUE;      /* command => no terminal */
 446
 447                 break;                 /* done with cmdline */
 448             }
 449         }
 450     }
 451
 452     if (errors)
 453         return 1;
 454
 455     if (!*cfg.host) {
 456         usage();
 457     }
 458
 459     /*
 460      * Trim leading whitespace off the hostname if it's there.
 461      */
 462     {
 463         int space = strspn(cfg.host, " \t");
 464         memmove(cfg.host, cfg.host+space, 1+strlen(cfg.host)-space);
 465     }
 466
 467     /* See if host is of the form user@host */
 468     if (cfg.host[0] != '\0') {
 469         char *atsign = strchr(cfg.host, '@');
 470         /* Make sure we're not overflowing the user field */
 471         if (atsign) {
 472             if (atsign - cfg.host < sizeof cfg.username) {
 473                 strncpy(cfg.username, cfg.host, atsign - cfg.host);
 474                 cfg.username[atsign - cfg.host] = '\0';
 475             }
 476             memmove(cfg.host, atsign + 1, 1 + strlen(atsign + 1));
 477         }
 478     }
 479
 480     /*
 481      * Perform command-line overrides on session configuration.
 482      */
 483     cmdline_run_saved(&cfg);
 484
 485     /*
 486      * Trim a colon suffix off the hostname if it's there.
 487      */
 488     cfg.host[strcspn(cfg.host, ":")] = '\0';
 489
 490     /*
 491      * Remove any remaining whitespace from the hostname.
 492      */
 493     {
 494         int p1 = 0, p2 = 0;
 495         while (cfg.host[p2] != '\0') {
 496             if (cfg.host[p2] != ' ' && cfg.host[p2] != '\t') {
 497                 cfg.host[p1] = cfg.host[p2];
 498                 p1++;
 499             }
 500             p2++;
 501         }
 502         cfg.host[p1] = '\0';
 503     }
 504
 505     if (!*cfg.remote_cmd_ptr)
 506         flags |= FLAG_INTERACTIVE;
 507
 508     /*
 509      * Select protocol. This is farmed out into a table in a
 510      * separate file to enable an ssh-free variant.
 511      */
 512     {
 513         int i;
 514         back = NULL;
 515         for (i = 0; backends[i].backend != NULL; i++)
 516             if (backends[i].protocol == cfg.protocol) {
 517                 back = backends[i].backend;
 518                 break;
 519             }
 520         if (back == NULL) {
 521             fprintf(stderr,
 522                     "Internal fault: Unsupported protocol found\n");
 523             return 1;
 524         }
 525     }
 526
 527     /*
 528      * Select port.
 529      */
 530     if (portnumber != -1)
 531         cfg.port = portnumber;
 532
 533     /*
 534      * Set up the pipe we'll use to tell us about SIGWINCH.
 535      */
 536     if (pipe(signalpipe) < 0) {
 537         perror("pipe");
 538         exit(1);
 539     }
 540     putty_signal(SIGWINCH, sigwinch);
 541
 542     sk_init();
 543
 544     /*
 545      * Start up the connection.
 546      */
 547     logctx = log_init(NULL);
 548     {
 549         char *error;
 550         char *realhost;
 551         /* nodelay is only useful if stdin is a terminal device */
 552         int nodelay = cfg.tcp_nodelay && isatty(0);
 553
 554         error = back->init(NULL, &backhandle, &cfg, cfg.host, cfg.port,
 555                            &realhost, nodelay);
 556         if (error) {
 557             fprintf(stderr, "Unable to open connection:\n%s\n", error);
 558             return 1;
 559         }
 560         back->provide_logctx(backhandle, logctx);
 561         ldisc = ldisc_create(&cfg, NULL, back, backhandle, NULL);
 562         sfree(realhost);
 563     }
 564     connopen = 1;
 565
 566     /*
 567      * Set up the initial console mode. We don't care if this call
 568      * fails, because we know we aren't necessarily running in a
 569      * console.
 570      */
 571     tcgetattr(0, &orig_termios);
 572     atexit(cleanup_termios);
 573     ldisc_update(NULL, 1, 1);
 574     sending = FALSE;
 575
 576     while (1) {
 577         fd_set rset, wset, xset;
 578         int maxfd;
 579         int rwx;
 580         int ret;
 581
 582         FD_ZERO(&rset);
 583         FD_ZERO(&wset);
 584         FD_ZERO(&xset);
 585         maxfd = 0;
 586
 587         FD_SET_MAX(signalpipe[0], maxfd, rset);
 588
 589         if (connopen && !sending &&
 590             back->socket(backhandle) != NULL &&
 591             back->sendok(backhandle) &&
 592             back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
 593             /* If we're OK to send, then try to read from stdin. */
 594             FD_SET_MAX(0, maxfd, rset);
 595         }
 596
 597         if (bufchain_size(&stdout_data) > 0) {
 598             /* If we have data for stdout, try to write to stdout. */
 599             FD_SET_MAX(1, maxfd, wset);
 600         }
 601
 602         if (bufchain_size(&stderr_data) > 0) {
 603             /* If we have data for stderr, try to write to stderr. */
 604             FD_SET_MAX(2, maxfd, wset);
 605         }
 606
 607         /* Count the currently active sockets. */
 608         i = 0;
 609         for (socket = first_socket(&socketstate, &rwx); socket >= 0;
 610              socket = next_socket(&socketstate, &rwx)) i++;
 611
 612         /* Expand the sklist buffer if necessary. */
 613         if (i > sksize) {
 614             sksize = i + 16;
 615             sklist = srealloc(sklist, sksize * sizeof(*sklist));
 616         }
 617
 618         /*
 619          * Add all currently open sockets to the select sets, and
 620          * store them in sklist as well.
 621          */
 622         skcount = 0;
 623         for (socket = first_socket(&socketstate, &rwx); socket >= 0;
 624              socket = next_socket(&socketstate, &rwx)) {
 625             sklist[skcount++] = socket;
 626             if (rwx & 1)
 627                 FD_SET_MAX(socket, maxfd, rset);
 628             if (rwx & 2)
 629                 FD_SET_MAX(socket, maxfd, wset);
 630             if (rwx & 4)
 631                 FD_SET_MAX(socket, maxfd, xset);
 632         }
 633
 634         do {
 635             ret = select(maxfd, &rset, &wset, &xset, NULL);
 636         } while (ret < 0 && errno == EINTR);
 637
 638         if (ret < 0) {
 639             perror("select");
 640             exit(1);
 641         }
 642
 643         for (i = 0; i < skcount; i++) {
 644             socket = sklist[i];
 645             /*
 646              * We must process exceptional notifications before
 647              * ordinary readability ones, or we may go straight
 648              * past the urgent marker.
 649              */
 650             if (FD_ISSET(socket, &xset))
 651                 select_result(socket, 4);
 652             if (FD_ISSET(socket, &rset))
 653                 select_result(socket, 1);
 654             if (FD_ISSET(socket, &wset))
 655                 select_result(socket, 2);
 656         }
 657
 658         if (FD_ISSET(signalpipe[0], &rset)) {
 659             char c[1];
 660             struct winsize size;
 661             read(signalpipe[0], c, 1); /* ignore its value; it'll be `x' */
 662             if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
 663                 back->size(backhandle, size.ws_col, size.ws_row);
 664         }
 665
 666         if (FD_ISSET(0, &rset)) {
 667             char buf[4096];
 668             int ret;
 669
 670             if (connopen && back->socket(backhandle) != NULL) {
 671                 ret = read(0, buf, sizeof(buf));
 672                 if (ret < 0) {
 673                     perror("stdin: read");
 674                     exit(1);
 675                 } else if (ret == 0) {
 676                     back->special(backhandle, TS_EOF);
 677                     sending = FALSE;   /* send nothing further after this */
 678                 } else {
 679                     back->send(backhandle, buf, ret);
 680                 }
 681             }
 682         }
 683
 684         if (FD_ISSET(1, &wset)) {
 685             try_output(0);
 686         }
 687
 688         if (FD_ISSET(2, &wset)) {
 689             try_output(1);
 690         }
 691
 692         if ((!connopen || back->socket(backhandle) == NULL) &&
 693             bufchain_size(&stdout_data) == 0 &&
 694             bufchain_size(&stderr_data) == 0)
 695             break;                     /* we closed the connection */
 696     }
 697     exitcode = back->exitcode(backhandle);
 698     if (exitcode < 0) {
 699         fprintf(stderr, "Remote process exit code unavailable\n");
 700         exitcode = 1;                  /* this is an error condition */
 701     }
 702     cleanup_exit(exitcode);
 703     return exitcode;                   /* shouldn't happen, but placates gcc */
 704 }