| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: sw_rsh.c,v 1.1 1999/06/02 16:53:34 mdw Exp $ |
| 4 | * |
| 5 | * Run remote commands |
| 6 | * |
| 7 | * (c) 1999 EBI |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of sw-tools. |
| 13 | * |
| 14 | * sw-tools is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * sw-tools is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with sw-tools; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Revision history --------------------------------------------------* |
| 30 | * |
| 31 | * $Log: sw_rsh.c,v $ |
| 32 | * Revision 1.1 1999/06/02 16:53:34 mdw |
| 33 | * Initial revision |
| 34 | * |
| 35 | */ |
| 36 | |
| 37 | /*----- Header files ------------------------------------------------------*/ |
| 38 | |
| 39 | #include "config.h" |
| 40 | |
| 41 | #include <ctype.h> |
| 42 | #include <errno.h> |
| 43 | #include <signal.h> |
| 44 | #include <stdarg.h> |
| 45 | #include <stdio.h> |
| 46 | #include <stdlib.h> |
| 47 | #include <string.h> |
| 48 | |
| 49 | #include <sys/types.h> |
| 50 | #include <sys/time.h> |
| 51 | #include <fcntl.h> |
| 52 | #include <unistd.h> |
| 53 | |
| 54 | #include <sys/socket.h> |
| 55 | #include <sys/wait.h> |
| 56 | |
| 57 | #ifndef DECL_ENVIRON |
| 58 | extern char **environ; |
| 59 | #endif |
| 60 | |
| 61 | #include <mLib/alloc.h> |
| 62 | #include <mLib/dstr.h> |
| 63 | #include <mLib/exc.h> |
| 64 | #include <mLib/mdwopt.h> |
| 65 | #include <mLib/quis.h> |
| 66 | #include <mLib/report.h> |
| 67 | #include <mLib/sym.h> |
| 68 | |
| 69 | #define RCMD_LINK 0 |
| 70 | #include "sw_arch.h" |
| 71 | #include "sw_build.h" |
| 72 | #include "sw_env.h" |
| 73 | #include "sw_rsh.h" |
| 74 | |
| 75 | /*----- Data structures ---------------------------------------------------*/ |
| 76 | |
| 77 | typedef unsigned char octet; |
| 78 | |
| 79 | #define PKHEADSZ 3 |
| 80 | |
| 81 | typedef struct pkhead { |
| 82 | octet len[2]; |
| 83 | octet type; |
| 84 | } pkhead; |
| 85 | |
| 86 | /*----- Static variables --------------------------------------------------*/ |
| 87 | |
| 88 | static int handler = 0; |
| 89 | static rcmd *rcmds = RCMD_LINK; |
| 90 | |
| 91 | /*----- Packet interface --------------------------------------------------*/ |
| 92 | |
| 93 | /* --- @pksend@ --- * |
| 94 | * |
| 95 | * Arguments: @sw_remote@ = pointer to the remote block |
| 96 | * @int type@ = packet type to send |
| 97 | * @const void *p@ = pointer to packet data |
| 98 | * @size_t sz@ = size of data to send |
| 99 | * |
| 100 | * Returns: Zero if it worked, nonzero otherwise. |
| 101 | * |
| 102 | * Use: Sends a data packet. If the type is `data', then `sz' may be |
| 103 | * arbitrarily large and is divided into small eenough chunks. |
| 104 | * Otherwise it's an error to send a packet that's too big. |
| 105 | */ |
| 106 | |
| 107 | int pksend(sw_remote *r, int type, const void *p, size_t sz) |
| 108 | { |
| 109 | pkhead h; |
| 110 | const char *q = p; |
| 111 | size_t chunk; |
| 112 | |
| 113 | /* --- Sort out error conditions --- */ |
| 114 | |
| 115 | if (sz > PKMAX && type != PKTYPE_DATA) { |
| 116 | errno = E2BIG; |
| 117 | return (-1); |
| 118 | } |
| 119 | |
| 120 | /* --- Main output loop --- */ |
| 121 | |
| 122 | h.type = type; |
| 123 | do { |
| 124 | |
| 125 | /* --- Set up the packet header --- */ |
| 126 | |
| 127 | chunk = (sz > PKMAX ? PKMAX : sz); |
| 128 | h.len[0] = chunk & 0xff; |
| 129 | h.len[1] = (chunk >> 8) & 0xff; |
| 130 | |
| 131 | /* --- Write the packet header --- */ |
| 132 | |
| 133 | try_again: |
| 134 | if (write(r->fdout, &h, PKHEADSZ) < PKHEADSZ) { |
| 135 | if (errno == EINTR) |
| 136 | goto try_again; |
| 137 | return (-1); |
| 138 | } |
| 139 | |
| 140 | /* --- Write the payload, if there is one --- * |
| 141 | * |
| 142 | * Maybe the OS won't want to bite it all off in one go. |
| 143 | */ |
| 144 | |
| 145 | while (chunk) { |
| 146 | ssize_t n = write(r->fdout, q, chunk); |
| 147 | if (n < 0 && errno != EINTR) |
| 148 | return (-1); |
| 149 | if (n > 0) { |
| 150 | q += n; |
| 151 | chunk -= n; |
| 152 | sz -= n; |
| 153 | } |
| 154 | } |
| 155 | } while (sz); |
| 156 | |
| 157 | /* --- Done --- */ |
| 158 | |
| 159 | return (0); |
| 160 | } |
| 161 | |
| 162 | /* --- @pkrecv@ --- * |
| 163 | * |
| 164 | * Arguments: @sw_remote *r@ = remote block |
| 165 | * |
| 166 | * Returns: Packet type received, or @-1@ for an error. |
| 167 | * |
| 168 | * Use: Receives a packet from the remote host. The packet data is |
| 169 | * placed in the block's buffer, the block's packet length is |
| 170 | * diddled appropriately. |
| 171 | */ |
| 172 | |
| 173 | int pkrecv(sw_remote *r) |
| 174 | { |
| 175 | pkhead h; |
| 176 | size_t sz; |
| 177 | char *p; |
| 178 | ssize_t n; |
| 179 | |
| 180 | /* --- Read the packet header --- */ |
| 181 | |
| 182 | sz = PKHEADSZ; |
| 183 | p = (char *)&h; |
| 184 | while (sz) { |
| 185 | n = read(r->fdin, p, sz); |
| 186 | if (n < 0 && errno != EINTR) |
| 187 | return (-1); |
| 188 | if (n == 0) |
| 189 | return (PKTYPE_EOF); |
| 190 | if (n > 0) { |
| 191 | p += n; |
| 192 | sz -= n; |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | /* --- Hack for error messages --- * |
| 197 | * |
| 198 | * If it doesn't look like a valid packet, read a `chunk' and pretend it's |
| 199 | * data. This isn't too bad, because all the packet types are control |
| 200 | * codes, and are unlikely to be in a textual message. |
| 201 | * |
| 202 | * Normally what happens here is that something sitting before the `sw' |
| 203 | * program fails, reports a plain textual error, and exits. Grabbing the |
| 204 | * `last gasp' like this, then, traps that error message and allows |
| 205 | * something to report it. The rest ought to be completely silent, so I |
| 206 | * get an `unexpected eof' and then drop everything. |
| 207 | * |
| 208 | * This is certainly better than the behaviour otherwise, which is an |
| 209 | * @E2BIG@ message reported when the packet size is really ASCII |
| 210 | * characters. |
| 211 | */ |
| 212 | |
| 213 | if (h.type >= PKTYPE_BOGUS) { |
| 214 | memcpy(r->buf, &h, PKHEADSZ); |
| 215 | n = read(r->fdin, r->buf + PKHEADSZ, sizeof(r->buf) - PKHEADSZ); |
| 216 | if (n < 0) |
| 217 | return (-1); |
| 218 | r->sz = n + PKHEADSZ; |
| 219 | return (PKTYPE_DATA); |
| 220 | } |
| 221 | |
| 222 | /* --- Sort out what's going on --- */ |
| 223 | |
| 224 | sz = h.len[0] | (h.len[1] << 8); |
| 225 | r->sz = sz; |
| 226 | if (!sz) |
| 227 | return (h.type); |
| 228 | if (sz > PKMAX) { |
| 229 | errno = E2BIG; |
| 230 | return (-1); |
| 231 | } |
| 232 | |
| 233 | /* --- Read the packet payload --- */ |
| 234 | |
| 235 | p = r->buf; |
| 236 | while (sz) { |
| 237 | n = read(r->fdin, p, sz); |
| 238 | if (n < 0 && errno != EINTR) |
| 239 | return (-1); |
| 240 | if (n == 0) |
| 241 | return (PKTYPE_EOF); |
| 242 | if (n > 0) { |
| 243 | p += n; |
| 244 | sz -= n; |
| 245 | } |
| 246 | } |
| 247 | |
| 248 | return (h.type); |
| 249 | } |
| 250 | |
| 251 | /*----- Error reporting and exit statuses --------------------------------*/ |
| 252 | |
| 253 | /* --- @swexit@ --- * |
| 254 | * |
| 255 | * Arguments: @sw_remote *r@ = remote context |
| 256 | * @int status@ = exit status to return |
| 257 | * |
| 258 | * Returns: Doesn't. |
| 259 | * |
| 260 | * Use: Reports the exit status via packet protocol and quits. |
| 261 | */ |
| 262 | |
| 263 | void swexit(sw_remote *r, int status) |
| 264 | { |
| 265 | unsigned char s = status; |
| 266 | pksend(r, PKTYPE_STATUS, &s, 1); |
| 267 | _exit(status); |
| 268 | } |
| 269 | |
| 270 | /* --- @swsignal@ --- * |
| 271 | * |
| 272 | * Arguments: @sw_remote *r@ = remote context |
| 273 | * @int sig@ = signal ocurrence to return |
| 274 | * |
| 275 | * Returns: Doesn't. |
| 276 | * |
| 277 | * Use: Reports a signalled-to-death status via packet protocol and |
| 278 | * quits. |
| 279 | */ |
| 280 | |
| 281 | void swsignal(sw_remote *r, int sig) |
| 282 | { |
| 283 | #if defined(HAVE_STRSIGNAL) |
| 284 | char *s = strsignal(sig); |
| 285 | #elif defined(HAVE__SYS_SIGLIST) |
| 286 | char *s = _sys_siglist[sig]; |
| 287 | #else |
| 288 | char s[16]; |
| 289 | sprintf(s, "signal %i", sig); |
| 290 | #endif |
| 291 | |
| 292 | pksend(r, PKTYPE_STATUS, s, strlen(s) + 1); |
| 293 | _exit(127); |
| 294 | } |
| 295 | |
| 296 | /* --- @swwait@ --- * |
| 297 | * |
| 298 | * Arguments: @sw_remote *r@ = remote context |
| 299 | * @int status@ = status answer from @wait@(2) |
| 300 | * |
| 301 | * Returns: Doesn't. |
| 302 | * |
| 303 | * Use: Reports a child's demise appropriately, and quits. |
| 304 | */ |
| 305 | |
| 306 | void swwait(sw_remote *r, int status) |
| 307 | { |
| 308 | if (WIFEXITED(status)) |
| 309 | swexit(r, WEXITSTATUS(status)); |
| 310 | else if (WIFSIGNALED(status)) |
| 311 | swsignal(r, WTERMSIG(status)); |
| 312 | else |
| 313 | swexit(r, 126); |
| 314 | } |
| 315 | |
| 316 | /* --- @swvprintf@ --- * |
| 317 | * |
| 318 | * Arguments: @sw_remote *r@ = remote context |
| 319 | * @const char *format@ = format string |
| 320 | * @va_list ap@ = things to format |
| 321 | * |
| 322 | * Returns: --- |
| 323 | * |
| 324 | * Use: Writes a string to the remote end. This is the low-level bit |
| 325 | * of @swprintf@. |
| 326 | */ |
| 327 | |
| 328 | void swvprintf(sw_remote *r, const char *format, va_list ap) |
| 329 | { |
| 330 | dstr d = DSTR_INIT; |
| 331 | dstr_vputf(&d, format, ap); |
| 332 | pksend(r, PKTYPE_DATA, d.buf, d.len); |
| 333 | dstr_destroy(&d); |
| 334 | } |
| 335 | |
| 336 | /* --- @swprintf@ --- * |
| 337 | * |
| 338 | * Arguments: @sw_remote *r@ = remote context |
| 339 | * @const char *format@ = format string |
| 340 | * @...@ = other arguments |
| 341 | * |
| 342 | * Returns: --- |
| 343 | * |
| 344 | * Use: Writes a string to the remote end. |
| 345 | */ |
| 346 | |
| 347 | void swprintf(sw_remote *r, const char *format, ...) |
| 348 | { |
| 349 | va_list ap; |
| 350 | va_start(ap, format); |
| 351 | swvprintf(r, format, ap); |
| 352 | va_end(ap); |
| 353 | } |
| 354 | |
| 355 | /* --- @swdie@ --- * |
| 356 | * |
| 357 | * Arguments: @sw_remote *r@ = remote context |
| 358 | * @int status@ = exit status to report |
| 359 | * @const char *format@ = format string to fill in |
| 360 | * @...@ = other arguments |
| 361 | * |
| 362 | * Returns: Doesn't. |
| 363 | * |
| 364 | * Use: Reports a message and quits. |
| 365 | */ |
| 366 | |
| 367 | void swdie(sw_remote *r, int status, const char *format, ...) |
| 368 | { |
| 369 | va_list ap; |
| 370 | dstr d = DSTR_INIT; |
| 371 | |
| 372 | va_start(ap, format); |
| 373 | dstr_putf(&d, "%s [remote]: ", QUIS); |
| 374 | dstr_vputf(&d, format, ap); |
| 375 | dstr_putc(&d, '\n'); |
| 376 | dstr_putz(&d); |
| 377 | va_end(ap); |
| 378 | pksend(r, PKTYPE_DATA, d.buf, d.len); |
| 379 | dstr_destroy(&d); |
| 380 | swexit(r, status); |
| 381 | } |
| 382 | |
| 383 | /*----- Command handling and dispatch -------------------------------------*/ |
| 384 | |
| 385 | /* --- @remote@ --- * |
| 386 | * |
| 387 | * Arguments: @sw_remote *r@ = pointer to remote block |
| 388 | * @const char *cmd@ = command to run |
| 389 | * @char *argv[]@ = argument array |
| 390 | * @char *env[]@ = environment variables |
| 391 | * |
| 392 | * Returns: Doesn't. Reports an exit status through packet protocol and |
| 393 | * quits. |
| 394 | * |
| 395 | * Use: Dispatches a remote command. At this point, the two code |
| 396 | * paths for local and remote invokation have joined again. |
| 397 | */ |
| 398 | |
| 399 | static void remote(sw_remote *r, const char *cmd, char *argv[], char *env[]) |
| 400 | { |
| 401 | struct rcmd *p, *chosen = 0; |
| 402 | size_t sz = strlen(cmd); |
| 403 | |
| 404 | /* --- Make sure that I can get the exit status of children --- */ |
| 405 | |
| 406 | signal(SIGCHLD, SIG_DFL); |
| 407 | |
| 408 | /* --- Fix up the environment --- */ |
| 409 | |
| 410 | { |
| 411 | sym_table t; |
| 412 | sym_create(&t); |
| 413 | env_import(&t, env); |
| 414 | if (env != environ) { |
| 415 | free(env); |
| 416 | env_import(&t, environ); |
| 417 | } |
| 418 | env_put(&t, "SW_ARCH", ARCH); |
| 419 | env_file(&t, DATADIR "/sw-env"); |
| 420 | env = env_export(&t); |
| 421 | } |
| 422 | |
| 423 | /* --- Dispatch to the command handler --- */ |
| 424 | |
| 425 | for (p = rcmds; p; p = p->next) { |
| 426 | if (strncmp(cmd, p->name, sz) == 0) { |
| 427 | if (p->name[sz] == 0) { |
| 428 | chosen = p; |
| 429 | break; |
| 430 | } else if (chosen) |
| 431 | swdie(r, 1, "ambiguous remote command name `%s'", cmd); |
| 432 | else |
| 433 | chosen = p; |
| 434 | } |
| 435 | } |
| 436 | if (!chosen) |
| 437 | swdie(r, 1, "unknown remote command name `%s'", cmd); |
| 438 | chosen->rcmd(r, argv, env); |
| 439 | } |
| 440 | |
| 441 | /*----- Remote invocation -------------------------------------------------*/ |
| 442 | |
| 443 | /* --- @sendargv@ --- * |
| 444 | * |
| 445 | * Arguments: @sw_remote *r@ = pointer to the remote context |
| 446 | * @int type@ = packet type to send with |
| 447 | * @char *v[]@ = pointer to the array to send |
| 448 | * |
| 449 | * Returns: Zero if OK, nonzero if it failed. |
| 450 | * |
| 451 | * Use: Sends something @argv@-shaped; i.e., an array of strings |
| 452 | * terminated by a null pointer. |
| 453 | */ |
| 454 | |
| 455 | static int sendargv(sw_remote *r, int type, char *v[]) |
| 456 | { |
| 457 | dstr d = DSTR_INIT; |
| 458 | int e; |
| 459 | |
| 460 | while (*v) { |
| 461 | dstr_puts(&d, *v); |
| 462 | d.len++; /* Make the null `real' */ |
| 463 | v++; |
| 464 | } |
| 465 | e = pksend(r, type, d.buf, d.len); |
| 466 | dstr_destroy(&d); |
| 467 | return (e); |
| 468 | } |
| 469 | |
| 470 | /* --- @snarfargv@ --- * |
| 471 | * |
| 472 | * Arguments: @const char *buf@ = pointer to buffer |
| 473 | * @size_t sz@ = size of buffer |
| 474 | * |
| 475 | * Returns: Pointer to argument array (allocated with @malloc@). |
| 476 | * |
| 477 | * Use: Snarfs the null-terminated strings in the buffer and returns |
| 478 | * an array of them. The whole lot, strings and array, is |
| 479 | * returned in one big chunk allocated from the heap. Note that |
| 480 | * this means it's OK to throw the initial buffer away. |
| 481 | */ |
| 482 | |
| 483 | static char **snarfargv(const char *buf, size_t sz) |
| 484 | { |
| 485 | /* --- Initial setup --- */ |
| 486 | |
| 487 | const char *p, *lim; |
| 488 | char *q; |
| 489 | size_t c; |
| 490 | char **v, **w; |
| 491 | |
| 492 | /* --- Pass one: count the number of arguments --- */ |
| 493 | |
| 494 | c = 0; |
| 495 | p = buf; |
| 496 | lim = p + sz; |
| 497 | while (p < lim) { |
| 498 | c++; |
| 499 | while (*p) { |
| 500 | p++; |
| 501 | if (p >= lim) |
| 502 | goto done_pass1; |
| 503 | } |
| 504 | p++; |
| 505 | } |
| 506 | done_pass1: |
| 507 | |
| 508 | /* --- Allocate memory for everything --- */ |
| 509 | |
| 510 | v = xmalloc((c + 1) * sizeof(char *) + sz + 1); |
| 511 | q = (char *)(v + c + 1); |
| 512 | memcpy(q, buf, sz); |
| 513 | |
| 514 | /* --- Pass two: set up the arrays --- */ |
| 515 | |
| 516 | lim = q + sz; |
| 517 | w = v; |
| 518 | while (q < lim) { |
| 519 | *w++ = q; |
| 520 | while (*q) { |
| 521 | q++; |
| 522 | if (q >= lim) |
| 523 | goto done_pass2; |
| 524 | } |
| 525 | q++; |
| 526 | } |
| 527 | done_pass2: |
| 528 | *w++ = 0; |
| 529 | *q++ = 0; |
| 530 | |
| 531 | /* --- Done --- */ |
| 532 | |
| 533 | return (v); |
| 534 | } |
| 535 | |
| 536 | /* --- @swrsh_remote@ --- * |
| 537 | * |
| 538 | * Arguments: @const char *cmd@ = the command to perform |
| 539 | * |
| 540 | * Returns: Doesn't. Reports an exit status through packet protocol and |
| 541 | * quits. |
| 542 | * |
| 543 | * Use: Handles the remote end of a remote job invokation. |
| 544 | */ |
| 545 | |
| 546 | void swrsh_remote(const char *cmd) |
| 547 | { |
| 548 | sw_remote r; |
| 549 | static char *dummy = 0; |
| 550 | char **argv = 0; |
| 551 | char **env = 0; |
| 552 | char *dir = 0; |
| 553 | r.fdin = 0; |
| 554 | r.fdout = 1; |
| 555 | |
| 556 | /* --- Read packets from the remote host --- */ |
| 557 | |
| 558 | for (;;) { |
| 559 | int t = pkrecv(&r); |
| 560 | switch (t) { |
| 561 | case -1: |
| 562 | swdie(&r, 1, "error reading packet: %s", strerror(errno)); |
| 563 | break; |
| 564 | case PKTYPE_EOF: |
| 565 | goto done; |
| 566 | case PKTYPE_ARGS: |
| 567 | if (argv) |
| 568 | free(argv); |
| 569 | argv = snarfargv(r.buf, r.sz); |
| 570 | break; |
| 571 | case PKTYPE_ENV: |
| 572 | if (env) |
| 573 | free(env); |
| 574 | env = snarfargv(r.buf, r.sz); |
| 575 | break; |
| 576 | case PKTYPE_DIR: |
| 577 | if (dir) |
| 578 | free(dir); |
| 579 | r.buf[r.sz] = 0; |
| 580 | dir = xstrdup(r.buf); |
| 581 | break; |
| 582 | case PKTYPE_GO: |
| 583 | goto done; |
| 584 | case PKTYPE_DATA: |
| 585 | case PKTYPE_STATUS: |
| 586 | swdie(&r, 1, "internal error: unexpected packet"); |
| 587 | break; |
| 588 | } |
| 589 | } |
| 590 | |
| 591 | /* --- Sort out any missing arguments --- */ |
| 592 | |
| 593 | done: |
| 594 | if (!argv) |
| 595 | argv = &dummy; |
| 596 | if (!env) |
| 597 | env = &dummy; |
| 598 | if (dir) |
| 599 | chdir(dir); |
| 600 | |
| 601 | /* --- Run the command --- */ |
| 602 | |
| 603 | TRY |
| 604 | remote(&r, cmd, argv, env); |
| 605 | CATCH switch (exc_type) { |
| 606 | case EXC_NOMEM: { |
| 607 | static char msg[] = "\nsw [remote]: not enough memory\n"; |
| 608 | pksend(&r, PKTYPE_DATA, msg, sizeof(msg) - 1); |
| 609 | swexit(&r, 1); |
| 610 | } break; |
| 611 | default: |
| 612 | swdie(&r, 1, "uncaught exception, type = %lx", exc_type); |
| 613 | } END_TRY; |
| 614 | } |
| 615 | |
| 616 | /*----- Starting remote jobs ----------------------------------------------*/ |
| 617 | |
| 618 | /* --- @sigchld@ --- * |
| 619 | * |
| 620 | * Arguments: @int sig@ = the signal number |
| 621 | * |
| 622 | * Returns: --- |
| 623 | * |
| 624 | * Use: Catches @SIGCHLD@ and reaps any children that have lost. |
| 625 | */ |
| 626 | |
| 627 | static void sigchld(int sig) |
| 628 | { |
| 629 | #ifdef DEBUG_SIGCHLD |
| 630 | int status; |
| 631 | while (waitpid(-1, &status, WNOHANG) > 0) { |
| 632 | if (WIFEXITED(status)) { |
| 633 | fprintf(stderr, "reap child with exit status %i\n", |
| 634 | WEXITSTATUS(status)); |
| 635 | } else if (WIFSIGNALED(status)) { |
| 636 | fprintf(stderr, "reap child killed by signal %s\n", |
| 637 | strsignal(WTERMSIG(status))); |
| 638 | } else |
| 639 | fprintf(stderr, "reaped bizarre child which is still alive\n"); |
| 640 | } |
| 641 | #else |
| 642 | while (waitpid(-1, 0, WNOHANG) > 0) |
| 643 | ; |
| 644 | #endif |
| 645 | } |
| 646 | |
| 647 | /* --- @swrsh@ --- * |
| 648 | * |
| 649 | * Arguments: @sw_remote *r@ = remote process block to look after |
| 650 | * @const char *host@ = host to run on (0 for this one) |
| 651 | * @const char *cmd@ = remote command to run |
| 652 | * @char *argv[]@ = arguments to pass on |
| 653 | * |
| 654 | * Returns: Zero if it worked, nonzero if not. |
| 655 | * |
| 656 | * Use: Runs a command on a remote host. The argument array is |
| 657 | * mangled to come out OK at the far end. The environment and |
| 658 | * current directory are also passed along, and pop out the |
| 659 | * other end unmolested. |
| 660 | */ |
| 661 | |
| 662 | int swrsh(sw_remote *r, const char *host, const char *cmd, char *argv[]) |
| 663 | { |
| 664 | int sk[2]; |
| 665 | pid_t kid; |
| 666 | |
| 667 | /* --- Get a socket pair for communicating with the other end --- */ |
| 668 | |
| 669 | if (socketpair(PF_UNIX, SOCK_STREAM, 0, sk)) |
| 670 | goto tidy_0; |
| 671 | |
| 672 | /* --- Set up a signal handler --- */ |
| 673 | |
| 674 | if (!handler) { |
| 675 | struct sigaction sa; |
| 676 | sa.sa_handler = sigchld; |
| 677 | sa.sa_flags = 0; |
| 678 | sigemptyset(&sa.sa_mask); |
| 679 | sigaction(SIGCHLD, &sa, 0); |
| 680 | handler = 1; |
| 681 | } |
| 682 | |
| 683 | /* --- Fork off a child to cope with stuff --- */ |
| 684 | |
| 685 | kid = fork(); |
| 686 | if (kid < 0) |
| 687 | goto tidy_1; |
| 688 | |
| 689 | /* --- Handle the child process --- * |
| 690 | * |
| 691 | * If this is a local job, then just loop around inside to handle the |
| 692 | * `remote' command. Otherwise crank up `rsh' and pass the command over to |
| 693 | * a remote copy of myself. |
| 694 | * |
| 695 | * (Why do I need a separate process for local jobs? I don't really, but |
| 696 | * it makes everything much simpler when running multiple jobs at the same |
| 697 | * time.) |
| 698 | */ |
| 699 | |
| 700 | if (kid == 0) { |
| 701 | close(sk[0]); |
| 702 | |
| 703 | /* --- Child end of a local job --- */ |
| 704 | |
| 705 | if (!host) { |
| 706 | r->fdin = r->fdout = sk[1]; |
| 707 | remote(r, cmd, argv, environ); |
| 708 | } |
| 709 | |
| 710 | /* --- Local child end of a remote job --- */ |
| 711 | |
| 712 | else { |
| 713 | const char *rsh; |
| 714 | dup2(sk[1], 0); |
| 715 | dup2(sk[1], 1); |
| 716 | dup2(sk[1], 2); |
| 717 | if (sk[1] > 2) |
| 718 | close(sk[1]); |
| 719 | rsh = getenv("SW_RSH"); |
| 720 | if (!rsh) |
| 721 | rsh = RSH; |
| 722 | execlp(rsh, rsh, host, PATH_SW, "--remote", cmd, (char *)0); |
| 723 | } |
| 724 | |
| 725 | /* --- I don't expect either to come back --- */ |
| 726 | |
| 727 | _exit(1); |
| 728 | } |
| 729 | |
| 730 | /* --- Local sort out of what to do --- * |
| 731 | * |
| 732 | * Either way, I've now got a socket tied to something which speaks my |
| 733 | * communication protocol. However, if this is a local job, then I can get |
| 734 | * going right away; otherwise, I've got to transmit various bits of |
| 735 | * information over the protocol. |
| 736 | */ |
| 737 | |
| 738 | r->fdin = r->fdout = sk[0]; |
| 739 | close(sk[1]); |
| 740 | |
| 741 | if (host) { |
| 742 | char buf[PKMAX]; |
| 743 | if (!getcwd(buf, sizeof(buf))) |
| 744 | goto tidy_1; |
| 745 | sendargv(r, PKTYPE_ARGS, argv); |
| 746 | sendargv(r, PKTYPE_ENV, environ); |
| 747 | pksend(r, PKTYPE_DIR, buf, strlen(buf) + 1); |
| 748 | pksend(r, PKTYPE_GO, 0, 0); |
| 749 | } |
| 750 | |
| 751 | /* --- Ready to rock'n'roll --- */ |
| 752 | |
| 753 | r->sz = 0; |
| 754 | return (0); |
| 755 | |
| 756 | /* --- Tidy up if it failed --- */ |
| 757 | |
| 758 | tidy_1: |
| 759 | close(sk[0]); |
| 760 | close(sk[1]); |
| 761 | tidy_0: |
| 762 | return (-1); |
| 763 | } |
| 764 | |
| 765 | /*----- Subcommands -------------------------------------------------------*/ |
| 766 | |
| 767 | /* --- @swrsh_rsh@ --- */ |
| 768 | |
| 769 | void rsw_rsh(sw_remote *r, char *argv[], char *env[]) |
| 770 | { |
| 771 | pid_t kid, k; |
| 772 | int pfd[2]; |
| 773 | int status; |
| 774 | |
| 775 | /* --- Create a pipe --- */ |
| 776 | |
| 777 | if (pipe(pfd)) |
| 778 | swdie(r, 1, "couldn't create pipe: %s", strerror(errno)); |
| 779 | |
| 780 | /* --- Start the child process up --- */ |
| 781 | |
| 782 | kid = fork(); |
| 783 | if (kid < 0) |
| 784 | swdie(r, 1, "fork failed: %s", strerror(errno)); |
| 785 | else if (kid == 0) { |
| 786 | int fd; |
| 787 | |
| 788 | /* --- Use my new environment --- */ |
| 789 | |
| 790 | environ = env; /* Yuk. */ |
| 791 | |
| 792 | /* --- Fiddle with pipe file descriptors --- */ |
| 793 | |
| 794 | close(pfd[0]); |
| 795 | dup2(pfd[1], 1); |
| 796 | dup2(pfd[1], 2); |
| 797 | if (pfd[1] > 2) |
| 798 | close(pfd[1]); |
| 799 | |
| 800 | /* --- Make sure it doesn't get any input --- */ |
| 801 | |
| 802 | close(0); |
| 803 | fd = open("/dev/null", O_RDONLY); |
| 804 | if (fd != 0) { |
| 805 | dup2(fd, 0); |
| 806 | close(fd); |
| 807 | } |
| 808 | |
| 809 | /* --- Run the program --- */ |
| 810 | |
| 811 | execvp(argv[0], argv); |
| 812 | die(1, "couldn't exec `%s': %s", argv[0], strerror(errno)); |
| 813 | } |
| 814 | |
| 815 | /* --- Read the data from the pipe until it closes --- */ |
| 816 | |
| 817 | close(pfd[1]); |
| 818 | for (;;) { |
| 819 | ssize_t n = read(pfd[0], r->buf, sizeof(r->buf)); |
| 820 | if (n < 0) |
| 821 | swdie(r, 1, "read error: %s", strerror(errno)); |
| 822 | else if (!n) |
| 823 | break; |
| 824 | else |
| 825 | pksend(r, PKTYPE_DATA, r->buf, n); |
| 826 | } |
| 827 | close(pfd[0]); |
| 828 | |
| 829 | /* --- Finally, reap the exit status and pass it on --- */ |
| 830 | |
| 831 | for (;;) { |
| 832 | k = wait(&status); |
| 833 | if (k == kid) |
| 834 | break; |
| 835 | if (k < 0) |
| 836 | swdie(r, 1, "error reaping child: %s", strerror(errno)); |
| 837 | } |
| 838 | swwait(r, status); |
| 839 | } |
| 840 | |
| 841 | /* --- @sw_rsh@ --- */ |
| 842 | |
| 843 | int sw_rsh(int argc, char *argv[]) |
| 844 | { |
| 845 | sw_remote r; |
| 846 | char *h; |
| 847 | int status = 1; |
| 848 | |
| 849 | /* --- Check the arguments --- */ |
| 850 | |
| 851 | if (argc < 3) |
| 852 | die(1, "Usage: rsh HOST|ARCH COMMAND [ARGS...]"); |
| 853 | |
| 854 | /* --- Translate architecture names into hostnames --- */ |
| 855 | |
| 856 | if (strcmp(argv[1], "-") == 0) |
| 857 | h = 0; |
| 858 | else { |
| 859 | archent *a = arch_lookup(argv[1], 0); |
| 860 | if (!a) |
| 861 | h = argv[1]; |
| 862 | else if (a->flags & archFlag_home) |
| 863 | h = 0; |
| 864 | else |
| 865 | h = a->host; |
| 866 | } |
| 867 | |
| 868 | /* --- Start the remote process --- */ |
| 869 | |
| 870 | if (swrsh(&r, h, "rsh", argv + 2)) |
| 871 | die(1, "remote shell failed: %s", strerror(errno)); |
| 872 | |
| 873 | /* --- Cope with packets from the remote process --- */ |
| 874 | |
| 875 | fflush(stdout); |
| 876 | for (;;) { |
| 877 | int t = pkrecv(&r); |
| 878 | switch (t) { |
| 879 | case -1: |
| 880 | die(1, "error reading packet: %s", strerror(errno)); |
| 881 | case PKTYPE_DATA: |
| 882 | write(STDOUT_FILENO, r.buf, r.sz); |
| 883 | break; |
| 884 | case PKTYPE_STATUS: |
| 885 | r.buf[r.sz] = 0; |
| 886 | if (r.sz > 1) { |
| 887 | status = 127; |
| 888 | moan("command exited due to signal: %s", r.buf); |
| 889 | } else { |
| 890 | status = r.buf[0]; |
| 891 | moan("command exited with status %i", r.buf[0]); |
| 892 | } |
| 893 | goto done; |
| 894 | case PKTYPE_EOF: |
| 895 | moan("command exited unexpectedly"); |
| 896 | goto done; |
| 897 | default: |
| 898 | die(1, "unexpected packet type"); |
| 899 | } |
| 900 | } |
| 901 | |
| 902 | /* --- Finished --- */ |
| 903 | |
| 904 | done: |
| 905 | close(r.fdin); |
| 906 | return (status); |
| 907 | } |
| 908 | |
| 909 | /*----- That's all, folks -------------------------------------------------*/ |