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

   1 /*
   2  * PLink - a command-line (stdin/stdout) variant of PuTTY.
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <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("  -L listen-port:host:port   Forward local port to "
 267            "remote address\n");
 268     printf("  -R listen-port:host:port   Forward remote port to"
 269            " local address\n");
 270     printf("  -X -x     enable / disable X11 forwarding\n");
 271     printf("  -A -a     enable / disable agent forwarding\n");
 272     printf("  -t -T     enable / disable pty allocation\n");
 273     printf("  -1 -2     force use of particular protocol version\n");
 274     printf("  -C        enable compression\n");
 275     printf("  -i key    private key file for authentication\n");
 276     exit(1);
 277 }
 278
 279 int main(int argc, char **argv)
 280 {
 281     int sending;
 282     int portnumber = -1;
 283     int *fdlist;
 284     int fd;
 285     int i, fdcount, fdsize, fdstate;
 286     int connopen;
 287     int exitcode;
 288     int errors;
 289     void *ldisc;
 290
 291     ssh_get_line = console_get_line;
 292
 293     fdlist = NULL;
 294     fdcount = fdsize = 0;
 295     /*
 296      * Initialise port and protocol to sensible defaults. (These
 297      * will be overridden by more or less anything.)
 298      */
 299     default_protocol = PROT_SSH;
 300     default_port = 22;
 301
 302     flags = FLAG_STDERR;
 303     /*
 304      * Process the command line.
 305      */
 306     do_defaults(NULL, &cfg);
 307     default_protocol = cfg.protocol;
 308     default_port = cfg.port;
 309     errors = 0;
 310     {
 311         /*
 312          * Override the default protocol if PLINK_PROTOCOL is set.
 313          */
 314         char *p = getenv("PLINK_PROTOCOL");
 315         int i;
 316         if (p) {
 317             for (i = 0; backends[i].backend != NULL; i++) {
 318                 if (!strcmp(backends[i].name, p)) {
 319                     default_protocol = cfg.protocol = backends[i].protocol;
 320                     default_port = cfg.port =
 321                         backends[i].backend->default_port;
 322                     break;
 323                 }
 324             }
 325         }
 326     }
 327     while (--argc) {
 328         char *p = *++argv;
 329         if (*p == '-') {
 330             int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
 331                                             1, &cfg);
 332             if (ret == -2) {
 333                 fprintf(stderr,
 334                         "plink: option \"%s\" requires an argument\n", p);
 335                 errors = 1;
 336             } else if (ret == 2) {
 337                 --argc, ++argv;
 338             } else if (ret == 1) {
 339                 continue;
 340             } else if (!strcmp(p, "-batch")) {
 341                 console_batch_mode = 1;
 342             } else if (!strcmp(p, "-o")) {
 343                 if (argc <= 1) {
 344                     fprintf(stderr,
 345                             "plink: option \"-o\" requires an argument\n");
 346                     errors = 1;
 347                 } else {
 348                     --argc;
 349                     provide_xrm_string(*++argv);
 350                 }
 351             } else {
 352                 fprintf(stderr, "plink: unknown option \"%s\"\n", p);
 353                 errors = 1;
 354             }
 355         } else if (*p) {
 356             if (!*cfg.host) {
 357                 char *q = p;
 358
 359                 do_defaults(NULL, &cfg);
 360
 361                 /*
 362                  * If the hostname starts with "telnet:", set the
 363                  * protocol to Telnet and process the string as a
 364                  * Telnet URL.
 365                  */
 366                 if (!strncmp(q, "telnet:", 7)) {
 367                     char c;
 368
 369                     q += 7;
 370                     if (q[0] == '/' && q[1] == '/')
 371                         q += 2;
 372                     cfg.protocol = PROT_TELNET;
 373                     p = q;
 374                     while (*p && *p != ':' && *p != '/')
 375                         p++;
 376                     c = *p;
 377                     if (*p)
 378                         *p++ = '\0';
 379                     if (c == ':')
 380                         cfg.port = atoi(p);
 381                     else
 382                         cfg.port = -1;
 383                     strncpy(cfg.host, q, sizeof(cfg.host) - 1);
 384                     cfg.host[sizeof(cfg.host) - 1] = '\0';
 385                 } else {
 386                     char *r;
 387                     /*
 388                      * Before we process the [user@]host string, we
 389                      * first check for the presence of a protocol
 390                      * prefix (a protocol name followed by ",").
 391                      */
 392                     r = strchr(p, ',');
 393                     if (r) {
 394                         int i, j;
 395                         for (i = 0; backends[i].backend != NULL; i++) {
 396                             j = strlen(backends[i].name);
 397                             if (j == r - p &&
 398                                 !memcmp(backends[i].name, p, j)) {
 399                                 default_protocol = cfg.protocol =
 400                                     backends[i].protocol;
 401                                 portnumber =
 402                                     backends[i].backend->default_port;
 403                                 p = r + 1;
 404                                 break;
 405                             }
 406                         }
 407                     }
 408
 409                     /*
 410                      * Three cases. Either (a) there's a nonzero
 411                      * length string followed by an @, in which
 412                      * case that's user and the remainder is host.
 413                      * Or (b) there's only one string, not counting
 414                      * a potential initial @, and it exists in the
 415                      * saved-sessions database. Or (c) only one
 416                      * string and it _doesn't_ exist in the
 417                      * database.
 418                      */
 419                     r = strrchr(p, '@');
 420                     if (r == p)
 421                         p++, r = NULL; /* discount initial @ */
 422                     if (r == NULL) {
 423                         /*
 424                          * One string.
 425                          */
 426                         Config cfg2;
 427                         do_defaults(p, &cfg2);
 428                         if (cfg2.host[0] == '\0') {
 429                             /* No settings for this host; use defaults */
 430                             strncpy(cfg.host, p, sizeof(cfg.host) - 1);
 431                             cfg.host[sizeof(cfg.host) - 1] = '\0';
 432                             cfg.port = default_port;
 433                         } else {
 434                             cfg = cfg2;
 435                             cfg.remote_cmd_ptr = cfg.remote_cmd;
 436                         }
 437                     } else {
 438                         *r++ = '\0';
 439                         strncpy(cfg.username, p, sizeof(cfg.username) - 1);
 440                         cfg.username[sizeof(cfg.username) - 1] = '\0';
 441                         strncpy(cfg.host, r, sizeof(cfg.host) - 1);
 442                         cfg.host[sizeof(cfg.host) - 1] = '\0';
 443                         cfg.port = default_port;
 444                     }
 445                 }
 446             } else {
 447                 char *command;
 448                 int cmdlen, cmdsize;
 449                 cmdlen = cmdsize = 0;
 450                 command = NULL;
 451
 452                 while (argc) {
 453                     while (*p) {
 454                         if (cmdlen >= cmdsize) {
 455                             cmdsize = cmdlen + 512;
 456                             command = sresize(command, cmdsize, char);
 457                         }
 458                         command[cmdlen++]=*p++;
 459                     }
 460                     if (cmdlen >= cmdsize) {
 461                         cmdsize = cmdlen + 512;
 462                         command = sresize(command, cmdsize, char);
 463                     }
 464                     command[cmdlen++]=' '; /* always add trailing space */
 465                     if (--argc) p = *++argv;
 466                 }
 467                 if (cmdlen) command[--cmdlen]='\0';
 468                                        /* change trailing blank to NUL */
 469                 cfg.remote_cmd_ptr = command;
 470                 cfg.remote_cmd_ptr2 = NULL;
 471                 cfg.nopty = TRUE;      /* command => no terminal */
 472
 473                 break;                 /* done with cmdline */
 474             }
 475         }
 476     }
 477
 478     if (errors)
 479         return 1;
 480
 481     if (!*cfg.host) {
 482         usage();
 483     }
 484
 485     /*
 486      * Trim leading whitespace off the hostname if it's there.
 487      */
 488     {
 489         int space = strspn(cfg.host, " \t");
 490         memmove(cfg.host, cfg.host+space, 1+strlen(cfg.host)-space);
 491     }
 492
 493     /* See if host is of the form user@host */
 494     if (cfg.host[0] != '\0') {
 495         char *atsign = strchr(cfg.host, '@');
 496         /* Make sure we're not overflowing the user field */
 497         if (atsign) {
 498             if (atsign - cfg.host < sizeof cfg.username) {
 499                 strncpy(cfg.username, cfg.host, atsign - cfg.host);
 500                 cfg.username[atsign - cfg.host] = '\0';
 501             }
 502             memmove(cfg.host, atsign + 1, 1 + strlen(atsign + 1));
 503         }
 504     }
 505
 506     /*
 507      * Perform command-line overrides on session configuration.
 508      */
 509     cmdline_run_saved(&cfg);
 510
 511     /*
 512      * Trim a colon suffix off the hostname if it's there.
 513      */
 514     cfg.host[strcspn(cfg.host, ":")] = '\0';
 515
 516     /*
 517      * Remove any remaining whitespace from the hostname.
 518      */
 519     {
 520         int p1 = 0, p2 = 0;
 521         while (cfg.host[p2] != '\0') {
 522             if (cfg.host[p2] != ' ' && cfg.host[p2] != '\t') {
 523                 cfg.host[p1] = cfg.host[p2];
 524                 p1++;
 525             }
 526             p2++;
 527         }
 528         cfg.host[p1] = '\0';
 529     }
 530
 531     if (!*cfg.remote_cmd_ptr)
 532         flags |= FLAG_INTERACTIVE;
 533
 534     /*
 535      * Select protocol. This is farmed out into a table in a
 536      * separate file to enable an ssh-free variant.
 537      */
 538     {
 539         int i;
 540         back = NULL;
 541         for (i = 0; backends[i].backend != NULL; i++)
 542             if (backends[i].protocol == cfg.protocol) {
 543                 back = backends[i].backend;
 544                 break;
 545             }
 546         if (back == NULL) {
 547             fprintf(stderr,
 548                     "Internal fault: Unsupported protocol found\n");
 549             return 1;
 550         }
 551     }
 552
 553     /*
 554      * Select port.
 555      */
 556     if (portnumber != -1)
 557         cfg.port = portnumber;
 558
 559     /*
 560      * Set up the pipe we'll use to tell us about SIGWINCH.
 561      */
 562     if (pipe(signalpipe) < 0) {
 563         perror("pipe");
 564         exit(1);
 565     }
 566     putty_signal(SIGWINCH, sigwinch);
 567
 568     sk_init();
 569     uxsel_init();
 570
 571     /*
 572      * Start up the connection.
 573      */
 574     logctx = log_init(NULL, &cfg);
 575     {
 576         char *error;
 577         char *realhost;
 578         /* nodelay is only useful if stdin is a terminal device */
 579         int nodelay = cfg.tcp_nodelay && isatty(0);
 580
 581         error = back->init(NULL, &backhandle, &cfg, cfg.host, cfg.port,
 582                            &realhost, nodelay);
 583         if (error) {
 584             fprintf(stderr, "Unable to open connection:\n%s\n", error);
 585             return 1;
 586         }
 587         back->provide_logctx(backhandle, logctx);
 588         ldisc = ldisc_create(&cfg, NULL, back, backhandle, NULL);
 589         sfree(realhost);
 590     }
 591     connopen = 1;
 592
 593     /*
 594      * Set up the initial console mode. We don't care if this call
 595      * fails, because we know we aren't necessarily running in a
 596      * console.
 597      */
 598     tcgetattr(0, &orig_termios);
 599     atexit(cleanup_termios);
 600     ldisc_update(NULL, 1, 1);
 601     sending = FALSE;
 602
 603     while (1) {
 604         fd_set rset, wset, xset;
 605         int maxfd;
 606         int rwx;
 607         int ret;
 608
 609         FD_ZERO(&rset);
 610         FD_ZERO(&wset);
 611         FD_ZERO(&xset);
 612         maxfd = 0;
 613
 614         FD_SET_MAX(signalpipe[0], maxfd, rset);
 615
 616         if (connopen && !sending &&
 617             back->socket(backhandle) != NULL &&
 618             back->sendok(backhandle) &&
 619             back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
 620             /* If we're OK to send, then try to read from stdin. */
 621             FD_SET_MAX(0, maxfd, rset);
 622         }
 623
 624         if (bufchain_size(&stdout_data) > 0) {
 625             /* If we have data for stdout, try to write to stdout. */
 626             FD_SET_MAX(1, maxfd, wset);
 627         }
 628
 629         if (bufchain_size(&stderr_data) > 0) {
 630             /* If we have data for stderr, try to write to stderr. */
 631             FD_SET_MAX(2, maxfd, wset);
 632         }
 633
 634         /* Count the currently active fds. */
 635         i = 0;
 636         for (fd = first_fd(&fdstate, &rwx); fd >= 0;
 637              fd = next_fd(&fdstate, &rwx)) i++;
 638
 639         /* Expand the fdlist buffer if necessary. */
 640         if (i > fdsize) {
 641             fdsize = i + 16;
 642             fdlist = sresize(fdlist, fdsize, int);
 643         }
 644
 645         /*
 646          * Add all currently open fds to the select sets, and store
 647          * them in fdlist as well.
 648          */
 649         fdcount = 0;
 650         for (fd = first_fd(&fdstate, &rwx); fd >= 0;
 651              fd = next_fd(&fdstate, &rwx)) {
 652             fdlist[fdcount++] = fd;
 653             if (rwx & 1)
 654                 FD_SET_MAX(fd, maxfd, rset);
 655             if (rwx & 2)
 656                 FD_SET_MAX(fd, maxfd, wset);
 657             if (rwx & 4)
 658                 FD_SET_MAX(fd, maxfd, xset);
 659         }
 660
 661         do {
 662             ret = select(maxfd, &rset, &wset, &xset, NULL);
 663         } while (ret < 0 && errno == EINTR);
 664
 665         if (ret < 0) {
 666             perror("select");
 667             exit(1);
 668         }
 669
 670         for (i = 0; i < fdcount; i++) {
 671             fd = fdlist[i];
 672             /*
 673              * We must process exceptional notifications before
 674              * ordinary readability ones, or we may go straight
 675              * past the urgent marker.
 676              */
 677             if (FD_ISSET(fd, &xset))
 678                 select_result(fd, 4);
 679             if (FD_ISSET(fd, &rset))
 680                 select_result(fd, 1);
 681             if (FD_ISSET(fd, &wset))
 682                 select_result(fd, 2);
 683         }
 684
 685         if (FD_ISSET(signalpipe[0], &rset)) {
 686             char c[1];
 687             struct winsize size;
 688             read(signalpipe[0], c, 1); /* ignore its value; it'll be `x' */
 689             if (ioctl(0, TIOCGWINSZ, (void *)&size) >= 0)
 690                 back->size(backhandle, size.ws_col, size.ws_row);
 691         }
 692
 693         if (FD_ISSET(0, &rset)) {
 694             char buf[4096];
 695             int ret;
 696
 697             if (connopen && back->socket(backhandle) != NULL) {
 698                 ret = read(0, buf, sizeof(buf));
 699                 if (ret < 0) {
 700                     perror("stdin: read");
 701                     exit(1);
 702                 } else if (ret == 0) {
 703                     back->special(backhandle, TS_EOF);
 704                     sending = FALSE;   /* send nothing further after this */
 705                 } else {
 706                     back->send(backhandle, buf, ret);
 707                 }
 708             }
 709         }
 710
 711         if (FD_ISSET(1, &wset)) {
 712             try_output(0);
 713         }
 714
 715         if (FD_ISSET(2, &wset)) {
 716             try_output(1);
 717         }
 718
 719         if ((!connopen || back->socket(backhandle) == NULL) &&
 720             bufchain_size(&stdout_data) == 0 &&
 721             bufchain_size(&stderr_data) == 0)
 722             break;                     /* we closed the connection */
 723     }
 724     exitcode = back->exitcode(backhandle);
 725     if (exitcode < 0) {
 726         fprintf(stderr, "Remote process exit code unavailable\n");
 727         exitcode = 1;                  /* this is an error condition */
 728     }
 729     cleanup_exit(exitcode);
 730     return exitcode;                   /* shouldn't happen, but placates gcc */
 731 }