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 static Config cfg;
  76
  77 /*
  78  * Default settings that are specific to pterm.
  79  */
  80 char *platform_default_s(const char *name)
  81 {
  82     if (!strcmp(name, "X11Display"))
  83         return getenv("DISPLAY");
  84     if (!strcmp(name, "TermType"))
  85         return getenv("TERM");
  86     if (!strcmp(name, "UserName")) {
  87         /*
  88          * Remote login username will default to the local username.
  89          */
  90         struct passwd *p;
  91         uid_t uid = getuid();
  92         char *user, *ret = NULL;
  93
  94         /*
  95          * First, find who we think we are using getlogin. If this
  96          * agrees with our uid, we'll go along with it. This should
  97          * allow sharing of uids between several login names whilst
  98          * coping correctly with people who have su'ed.
  99          */
 100         user = getlogin();
 101         setpwent();
 102         if (user)
 103             p = getpwnam(user);
 104         else
 105             p = NULL;
 106         if (p && p->pw_uid == uid) {
 107             /*
 108              * The result of getlogin() really does correspond to
 109              * our uid. Fine.
 110              */
 111             ret = user;
 112         } else {
 113             /*
 114              * If that didn't work, for whatever reason, we'll do
 115              * the simpler version: look up our uid in the password
 116              * file and map it straight to a name.
 117              */
 118             p = getpwuid(uid);
 119             ret = p->pw_name;
 120         }
 121         endpwent();
 122
 123         return ret;
 124     }
 125     return NULL;
 126 }
 127
 128 int platform_default_i(const char *name, int def)
 129 {
 130     if (!strcmp(name, "TermWidth") ||
 131         !strcmp(name, "TermHeight")) {
 132         struct winsize size;
 133         if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
 134             return (!strcmp(name, "TermWidth") ? size.ws_col : size.ws_row);
 135     }
 136     return def;
 137 }
 138
 139 FontSpec platform_default_fontspec(const char *name)
 140 {
 141     FontSpec ret;
 142     *ret.name = '\0';
 143     return ret;
 144 }
 145
 146 Filename platform_default_filename(const char *name)
 147 {
 148     Filename ret;
 149     if (!strcmp(name, "LogFileName"))
 150         strcpy(ret.path, "putty.log");
 151     else
 152         *ret.path = '\0';
 153     return ret;
 154 }
 155
 156 char *x_get_default(const char *key)
 157 {
 158     return NULL;                       /* this is a stub */
 159 }
 160 int term_ldisc(Terminal *term, int mode)
 161 {
 162     return FALSE;
 163 }
 164 void ldisc_update(void *frontend, int echo, int edit)
 165 {
 166     /* Update stdin read mode to reflect changes in line discipline. */
 167     struct termios mode;
 168
 169     mode = orig_termios;
 170
 171     if (echo)
 172         mode.c_lflag |= ECHO;
 173     else
 174         mode.c_lflag &= ~ECHO;
 175
 176     if (edit)
 177         mode.c_lflag |= ISIG | ICANON;
 178     else
 179         mode.c_lflag &= ~(ISIG | ICANON);
 180
 181     tcsetattr(0, TCSANOW, &mode);
 182 }
 183
 184 void cleanup_termios(void)
 185 {
 186     tcsetattr(0, TCSANOW, &orig_termios);
 187 }
 188
 189 bufchain stdout_data, stderr_data;
 190
 191 void try_output(int is_stderr)
 192 {
 193     bufchain *chain = (is_stderr ? &stderr_data : &stdout_data);
 194     int fd = (is_stderr ? 2 : 1);
 195     void *senddata;
 196     int sendlen, ret;
 197
 198     if (bufchain_size(chain) == 0)
 199         return;
 200
 201     bufchain_prefix(chain, &senddata, &sendlen);
 202     ret = write(fd, senddata, sendlen);
 203     if (ret > 0)
 204         bufchain_consume(chain, ret);
 205     else if (ret < 0) {
 206         perror(is_stderr ? "stderr: write" : "stdout: write");
 207         exit(1);
 208     }
 209 }
 210
 211 int from_backend(void *frontend_handle, int is_stderr,
 212                  const char *data, int len)
 213 {
 214     int osize, esize;
 215
 216     assert(len > 0);
 217
 218     if (is_stderr) {
 219         bufchain_add(&stderr_data, data, len);
 220         try_output(1);
 221     } else {
 222         bufchain_add(&stdout_data, data, len);
 223         try_output(0);
 224     }
 225
 226     osize = bufchain_size(&stdout_data);
 227     esize = bufchain_size(&stderr_data);
 228
 229     return osize + esize;
 230 }
 231
 232 int signalpipe[2];
 233
 234 void sigwinch(int signum)
 235 {
 236     write(signalpipe[1], "x", 1);
 237 }
 238
 239 /*
 240  * In Plink our selects are synchronous, so these functions are
 241  * empty stubs.
 242  */
 243 int uxsel_input_add(int fd, int rwx) { return 0; }
 244 void uxsel_input_remove(int id) { }
 245
 246 /*
 247  * Short description of parameters.
 248  */
 249 static void usage(void)
 250 {
 251     printf("PuTTY Link: command-line connection utility\n");
 252     printf("%s\n", ver);
 253     printf("Usage: plink [options] [user@]host [command]\n");
 254     printf("       (\"host\" can also be a PuTTY saved session name)\n");
 255     printf("Options:\n");
 256     printf("  -v        show verbose messages\n");
 257     printf("  -load sessname  Load settings from saved session\n");
 258     printf("  -ssh -telnet -rlogin -raw\n");
 259     printf("            force use of a particular protocol (default SSH)\n");
 260     printf("  -P port   connect to specified port\n");
 261     printf("  -l user   connect with specified username\n");
 262     printf("  -m file   read remote command(s) from file\n");
 263     printf("  -batch    disable all interactive prompts\n");
 264     printf("The following options only apply to SSH connections:\n");
 265     printf("  -pw passw login with specified password\n");
 266     printf("  -D listen-port   Dynamic SOCKS-based port forwarding\n");
 267     printf("  -L listen-port:host:port   Forward local port to "
 268            "remote address\n");
 269     printf("  -R listen-port:host:port   Forward remote port to"
 270            " local address\n");
 271     printf("  -X -x     enable / disable X11 forwarding\n");
 272     printf("  -A -a     enable / disable agent forwarding\n");
 273     printf("  -t -T     enable / disable pty allocation\n");
 274     printf("  -1 -2     force use of particular protocol version\n");
 275     printf("  -C        enable compression\n");
 276     printf("  -i key    private key file for authentication\n");
 277     exit(1);
 278 }
 279
 280 int main(int argc, char **argv)
 281 {
 282     int sending;
 283     int portnumber = -1;
 284     int *fdlist;
 285     int fd;
 286     int i, fdcount, fdsize, fdstate;
 287     int connopen;
 288     int exitcode;
 289     int errors;
 290     void *ldisc;
 291
 292     ssh_get_line = console_get_line;
 293
 294     fdlist = NULL;
 295     fdcount = fdsize = 0;
 296     /*
 297      * Initialise port and protocol to sensible defaults. (These
 298      * will be overridden by more or less anything.)
 299      */
 300     default_protocol = PROT_SSH;
 301     default_port = 22;
 302
 303     flags = FLAG_STDERR;
 304     /*
 305      * Process the command line.
 306      */
 307     do_defaults(NULL, &cfg);
 308     default_protocol = cfg.protocol;
 309     default_port = cfg.port;
 310     errors = 0;
 311     {
 312         /*
 313          * Override the default protocol if PLINK_PROTOCOL is set.
 314          */
 315         char *p = getenv("PLINK_PROTOCOL");
 316         int i;
 317         if (p) {
 318             for (i = 0; backends[i].backend != NULL; i++) {
 319                 if (!strcmp(backends[i].name, p)) {
 320                     default_protocol = cfg.protocol = backends[i].protocol;
 321                     default_port = cfg.port =
 322                         backends[i].backend->default_port;
 323                     break;
 324                 }
 325             }
 326         }
 327     }
 328     while (--argc) {
 329         char *p = *++argv;
 330         if (*p == '-') {
 331             int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
 332                                             1, &cfg);
 333             if (ret == -2) {
 334                 fprintf(stderr,
 335                         "plink: option \"%s\" requires an argument\n", p);
 336                 errors = 1;
 337             } else if (ret == 2) {
 338                 --argc, ++argv;
 339             } else if (ret == 1) {
 340                 continue;
 341             } else if (!strcmp(p, "-batch")) {
 342                 console_batch_mode = 1;
 343             } else if (!strcmp(p, "-o")) {
 344                 if (argc <= 1) {
 345                     fprintf(stderr,
 346                             "plink: option \"-o\" requires an argument\n");
 347                     errors = 1;
 348                 } else {
 349                     --argc;
 350                     provide_xrm_string(*++argv);
 351                 }
 352             } else {
 353                 fprintf(stderr, "plink: unknown option \"%s\"\n", p);
 354                 errors = 1;
 355             }
 356         } else if (*p) {
 357             if (!*cfg.host) {
 358                 char *q = p;
 359
 360                 do_defaults(NULL, &cfg);
 361
 362                 /*
 363                  * If the hostname starts with "telnet:", set the
 364                  * protocol to Telnet and process the string as a
 365                  * Telnet URL.
 366                  */
 367                 if (!strncmp(q, "telnet:", 7)) {
 368                     char c;
 369
 370                     q += 7;
 371                     if (q[0] == '/' && q[1] == '/')
 372                         q += 2;
 373                     cfg.protocol = PROT_TELNET;
 374                     p = q;
 375                     while (*p && *p != ':' && *p != '/')
 376                         p++;
 377                     c = *p;
 378                     if (*p)
 379                         *p++ = '\0';
 380                     if (c == ':')
 381                         cfg.port = atoi(p);
 382                     else
 383                         cfg.port = -1;
 384                     strncpy(cfg.host, q, sizeof(cfg.host) - 1);
 385                     cfg.host[sizeof(cfg.host) - 1] = '\0';
 386                 } else {
 387                     char *r;
 388                     /*
 389                      * Before we process the [user@]host string, we
 390                      * first check for the presence of a protocol
 391                      * prefix (a protocol name followed by ",").
 392                      */
 393                     r = strchr(p, ',');
 394                     if (r) {
 395                         int i, j;
 396                         for (i = 0; backends[i].backend != NULL; i++) {
 397                             j = strlen(backends[i].name);
 398                             if (j == r - p &&
 399                                 !memcmp(backends[i].name, p, j)) {
 400                                 default_protocol = cfg.protocol =
 401                                     backends[i].protocol;
 402                                 portnumber =
 403                                     backends[i].backend->default_port;
 404                                 p = r + 1;
 405                                 break;
 406                             }
 407                         }
 408                     }
 409
 410                     /*
 411                      * Three cases. Either (a) there's a nonzero
 412                      * length string followed by an @, in which
 413                      * case that's user and the remainder is host.
 414                      * Or (b) there's only one string, not counting
 415                      * a potential initial @, and it exists in the
 416                      * saved-sessions database. Or (c) only one
 417                      * string and it _doesn't_ exist in the
 418                      * database.
 419                      */
 420                     r = strrchr(p, '@');
 421                     if (r == p)
 422                         p++, r = NULL; /* discount initial @ */
 423                     if (r == NULL) {
 424                         /*
 425                          * One string.
 426                          */
 427                         Config cfg2;
 428                         do_defaults(p, &cfg2);
 429                         if (cfg2.host[0] == '\0') {
 430                             /* No settings for this host; use defaults */
 431                             strncpy(cfg.host, p, sizeof(cfg.host) - 1);
 432                             cfg.host[sizeof(cfg.host) - 1] = '\0';
 433                             cfg.port = default_port;
 434                         } else {
 435                             cfg = cfg2;
 436                             cfg.remote_cmd_ptr = cfg.remote_cmd;
 437                         }
 438                     } else {
 439                         *r++ = '\0';
 440                         strncpy(cfg.username, p, sizeof(cfg.username) - 1);
 441                         cfg.username[sizeof(cfg.username) - 1] = '\0';
 442                         strncpy(cfg.host, r, sizeof(cfg.host) - 1);
 443                         cfg.host[sizeof(cfg.host) - 1] = '\0';
 444                         cfg.port = default_port;
 445                     }
 446                 }
 447             } else {
 448                 char *command;
 449                 int cmdlen, cmdsize;
 450                 cmdlen = cmdsize = 0;
 451                 command = NULL;
 452
 453                 while (argc) {
 454                     while (*p) {
 455                         if (cmdlen >= cmdsize) {
 456                             cmdsize = cmdlen + 512;
 457                             command = sresize(command, cmdsize, char);
 458                         }
 459                         command[cmdlen++]=*p++;
 460                     }
 461                     if (cmdlen >= cmdsize) {
 462                         cmdsize = cmdlen + 512;
 463                         command = sresize(command, cmdsize, char);
 464                     }
 465                     command[cmdlen++]=' '; /* always add trailing space */
 466                     if (--argc) p = *++argv;
 467                 }
 468                 if (cmdlen) command[--cmdlen]='\0';
 469                                        /* change trailing blank to NUL */
 470                 cfg.remote_cmd_ptr = command;
 471                 cfg.remote_cmd_ptr2 = NULL;
 472                 cfg.nopty = TRUE;      /* command => no terminal */
 473
 474                 break;                 /* done with cmdline */
 475             }
 476         }
 477     }
 478
 479     if (errors)
 480         return 1;
 481
 482     if (!*cfg.host) {
 483         usage();
 484     }
 485
 486     /*
 487      * Trim leading whitespace off the hostname if it's there.
 488      */
 489     {
 490         int space = strspn(cfg.host, " \t");
 491         memmove(cfg.host, cfg.host+space, 1+strlen(cfg.host)-space);
 492     }
 493
 494     /* See if host is of the form user@host */
 495     if (cfg.host[0] != '\0') {
 496         char *atsign = strchr(cfg.host, '@');
 497         /* Make sure we're not overflowing the user field */
 498         if (atsign) {
 499             if (atsign - cfg.host < sizeof cfg.username) {
 500                 strncpy(cfg.username, cfg.host, atsign - cfg.host);
 501                 cfg.username[atsign - cfg.host] = '\0';
 502             }
 503             memmove(cfg.host, atsign + 1, 1 + strlen(atsign + 1));
 504         }
 505     }
 506
 507     /*
 508      * Perform command-line overrides on session configuration.
 509      */
 510     cmdline_run_saved(&cfg);
 511
 512     /*
 513      * Trim a colon suffix off the hostname if it's there.
 514      */
 515     cfg.host[strcspn(cfg.host, ":")] = '\0';
 516
 517     /*
 518      * Remove any remaining whitespace from the hostname.
 519      */
 520     {
 521         int p1 = 0, p2 = 0;
 522         while (cfg.host[p2] != '\0') {
 523             if (cfg.host[p2] != ' ' && cfg.host[p2] != '\t') {
 524                 cfg.host[p1] = cfg.host[p2];
 525                 p1++;
 526             }
 527             p2++;
 528         }
 529         cfg.host[p1] = '\0';
 530     }
 531
 532     if (!*cfg.remote_cmd_ptr)
 533         flags |= FLAG_INTERACTIVE;
 534
 535     /*
 536      * Select protocol. This is farmed out into a table in a
 537      * separate file to enable an ssh-free variant.
 538      */
 539     {
 540         int i;
 541         back = NULL;
 542         for (i = 0; backends[i].backend != NULL; i++)
 543             if (backends[i].protocol == cfg.protocol) {
 544                 back = backends[i].backend;
 545                 break;
 546             }
 547         if (back == NULL) {
 548             fprintf(stderr,
 549                     "Internal fault: Unsupported protocol found\n");
 550             return 1;
 551         }
 552     }
 553
 554     /*
 555      * Select port.
 556      */
 557     if (portnumber != -1)
 558         cfg.port = portnumber;
 559
 560     /*
 561      * Set up the pipe we'll use to tell us about SIGWINCH.
 562      */
 563     if (pipe(signalpipe) < 0) {
 564         perror("pipe");
 565         exit(1);
 566     }
 567     putty_signal(SIGWINCH, sigwinch);
 568
 569     sk_init();
 570     uxsel_init();
 571
 572     /*
 573      * Start up the connection.
 574      */
 575     logctx = log_init(NULL, &cfg);
 576     {
 577         const char *error;
 578         char *realhost;
 579         /* nodelay is only useful if stdin is a terminal device */
 580         int nodelay = cfg.tcp_nodelay && isatty(0);
 581
 582         error = back->init(NULL, &backhandle, &cfg, cfg.host, cfg.port,
 583                            &realhost, nodelay);
 584         if (error) {
 585             fprintf(stderr, "Unable to open connection:\n%s\n", error);
 586             return 1;
 587         }
 588         back->provide_logctx(backhandle, logctx);
 589         ldisc = ldisc_create(&cfg, NULL, back, backhandle, NULL);
 590         sfree(realhost);
 591     }
 592     connopen = 1;
 593
 594     /*
 595      * Set up the initial console mode. We don't care if this call
 596      * fails, because we know we aren't necessarily running in a
 597      * console.
 598      */
 599     tcgetattr(0, &orig_termios);
 600     atexit(cleanup_termios);
 601     ldisc_update(NULL, 1, 1);
 602     sending = FALSE;
 603
 604     while (1) {
 605         fd_set rset, wset, xset;
 606         int maxfd;
 607         int rwx;
 608         int ret;
 609
 610         FD_ZERO(&rset);
 611         FD_ZERO(&wset);
 612         FD_ZERO(&xset);
 613         maxfd = 0;
 614
 615         FD_SET_MAX(signalpipe[0], maxfd, rset);
 616
 617         if (connopen && !sending &&
 618             back->socket(backhandle) != NULL &&
 619             back->sendok(backhandle) &&
 620             back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
 621             /* If we're OK to send, then try to read from stdin. */
 622             FD_SET_MAX(0, maxfd, rset);
 623         }
 624
 625         if (bufchain_size(&stdout_data) > 0) {
 626             /* If we have data for stdout, try to write to stdout. */
 627             FD_SET_MAX(1, maxfd, wset);
 628         }
 629
 630         if (bufchain_size(&stderr_data) > 0) {
 631             /* If we have data for stderr, try to write to stderr. */
 632             FD_SET_MAX(2, maxfd, wset);
 633         }
 634
 635         /* Count the currently active fds. */
 636         i = 0;
 637         for (fd = first_fd(&fdstate, &rwx); fd >= 0;
 638              fd = next_fd(&fdstate, &rwx)) i++;
 639
 640         /* Expand the fdlist buffer if necessary. */
 641         if (i > fdsize) {
 642             fdsize = i + 16;
 643             fdlist = sresize(fdlist, fdsize, int);
 644         }
 645
 646         /*
 647          * Add all currently open fds to the select sets, and store
 648          * them in fdlist as well.
 649          */
 650         fdcount = 0;
 651         for (fd = first_fd(&fdstate, &rwx); fd >= 0;
 652              fd = next_fd(&fdstate, &rwx)) {
 653             fdlist[fdcount++] = fd;
 654             if (rwx & 1)
 655                 FD_SET_MAX(fd, maxfd, rset);
 656             if (rwx & 2)
 657                 FD_SET_MAX(fd, maxfd, wset);
 658             if (rwx & 4)
 659                 FD_SET_MAX(fd, maxfd, xset);
 660         }
 661
 662         do {
 663             ret = select(maxfd, &rset, &wset, &xset, NULL);
 664         } while (ret < 0 && errno == EINTR);
 665
 666         if (ret < 0) {
 667             perror("select");
 668             exit(1);
 669         }
 670
 671         for (i = 0; i < fdcount; i++) {
 672             fd = fdlist[i];
 673             /*
 674              * We must process exceptional notifications before
 675              * ordinary readability ones, or we may go straight
 676              * past the urgent marker.
 677              */
 678             if (FD_ISSET(fd, &xset))
 679                 select_result(fd, 4);
 680             if (FD_ISSET(fd, &rset))
 681                 select_result(fd, 1);
 682             if (FD_ISSET(fd, &wset))
 683                 select_result(fd, 2);
 684         }
 685
 686         if (FD_ISSET(signalpipe[0], &rset)) {
 687             char c[1];
 688             struct winsize size;
 689             read(signalpipe[0], c, 1); /* ignore its value; it'll be `x' */
 690             if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
 691                 back->size(backhandle, size.ws_col, size.ws_row);
 692         }
 693
 694         if (FD_ISSET(0, &rset)) {
 695             char buf[4096];
 696             int ret;
 697
 698             if (connopen && back->socket(backhandle) != NULL) {
 699                 ret = read(0, buf, sizeof(buf));
 700                 if (ret < 0) {
 701                     perror("stdin: read");
 702                     exit(1);
 703                 } else if (ret == 0) {
 704                     back->special(backhandle, TS_EOF);
 705                     sending = FALSE;   /* send nothing further after this */
 706                 } else {
 707                     back->send(backhandle, buf, ret);
 708                 }
 709             }
 710         }
 711
 712         if (FD_ISSET(1, &wset)) {
 713             try_output(0);
 714         }
 715
 716         if (FD_ISSET(2, &wset)) {
 717             try_output(1);
 718         }
 719
 720         if ((!connopen || back->socket(backhandle) == NULL) &&
 721             bufchain_size(&stdout_data) == 0 &&
 722             bufchain_size(&stderr_data) == 0)
 723             break;                     /* we closed the connection */
 724     }
 725     exitcode = back->exitcode(backhandle);
 726     if (exitcode < 0) {
 727         fprintf(stderr, "Remote process exit code unavailable\n");
 728         exitcode = 1;                  /* this is an error condition */
 729     }
 730     cleanup_exit(exitcode);
 731     return exitcode;                   /* shouldn't happen, but placates gcc */
 732 }