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