| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: exec.c,v 1.8 2003/11/29 20:36:07 mdw Exp $ |
| 4 | * |
| 5 | * Source and target for executable programs |
| 6 | * |
| 7 | * (c) 1999 Straylight/Edgeware |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of the `fw' port forwarder. |
| 13 | * |
| 14 | * `fw' 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 | * `fw' 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 `fw'; 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: exec.c,v $ |
| 32 | * Revision 1.8 2003/11/29 20:36:07 mdw |
| 33 | * Privileged outgoing connections. |
| 34 | * |
| 35 | * Revision 1.7 2003/01/24 20:12:26 mdw |
| 36 | * Correctly cast uid and gid sentinel values. Parse full filenames in |
| 37 | * exec arguments (can't do it for program, unfortunately, since the die is |
| 38 | * cast). |
| 39 | * |
| 40 | * Revision 1.6 2002/02/22 23:43:32 mdw |
| 41 | * Call @xfree@ rather than @free@. |
| 42 | * |
| 43 | * Revision 1.5 2002/01/13 14:49:03 mdw |
| 44 | * Track @lbuf@ changes in mLib. |
| 45 | * |
| 46 | * Revision 1.4 2001/02/03 20:30:03 mdw |
| 47 | * Support re-reading config files on SIGHUP. |
| 48 | * |
| 49 | * Revision 1.3 2000/07/01 11:28:52 mdw |
| 50 | * Use new mLib selbuf features. |
| 51 | * |
| 52 | * Revision 1.2 1999/10/22 22:46:17 mdw |
| 53 | * When a non-file endpoint is attached to a file, keep the file endpoint |
| 54 | * open until the nonfile is done. This stops socket sources from |
| 55 | * resetting their connection limits too early. |
| 56 | * |
| 57 | * Revision 1.1 1999/07/26 23:33:32 mdw |
| 58 | * New sources and targets. |
| 59 | * |
| 60 | */ |
| 61 | |
| 62 | /*----- Header files ------------------------------------------------------*/ |
| 63 | |
| 64 | #include "config.h" |
| 65 | |
| 66 | #define _GNU_SOURCE |
| 67 | |
| 68 | #include <ctype.h> |
| 69 | #include <errno.h> |
| 70 | #include <signal.h> |
| 71 | #include <stdio.h> |
| 72 | #include <stdlib.h> |
| 73 | #include <string.h> |
| 74 | |
| 75 | #include <sys/types.h> |
| 76 | #include <sys/stat.h> |
| 77 | #include <unistd.h> |
| 78 | #include <fcntl.h> |
| 79 | #include <sys/wait.h> |
| 80 | |
| 81 | #ifdef HAVE_SETRLIMIT |
| 82 | # include <sys/resource.h> |
| 83 | #endif |
| 84 | |
| 85 | #ifndef DECL_ENVIRON |
| 86 | extern char **environ; |
| 87 | #endif |
| 88 | |
| 89 | #include <pwd.h> |
| 90 | #include <grp.h> |
| 91 | |
| 92 | #include <syslog.h> |
| 93 | |
| 94 | #include <mLib/alloc.h> |
| 95 | #include <mLib/dstr.h> |
| 96 | #include <mLib/env.h> |
| 97 | #include <mLib/fdflags.h> |
| 98 | #include <mLib/report.h> |
| 99 | #include <mLib/sel.h> |
| 100 | #include <mLib/selbuf.h> |
| 101 | #include <mLib/sig.h> |
| 102 | #include <mLib/sub.h> |
| 103 | #include <mLib/sym.h> |
| 104 | |
| 105 | #include "conf.h" |
| 106 | #include "endpt.h" |
| 107 | #include "exec.h" |
| 108 | #include "fattr.h" |
| 109 | #include "fw.h" |
| 110 | #include "reffd.h" |
| 111 | #include "scan.h" |
| 112 | #include "source.h" |
| 113 | #include "target.h" |
| 114 | |
| 115 | /*----- Data structures ---------------------------------------------------*/ |
| 116 | |
| 117 | /* --- Resource usage --- */ |
| 118 | |
| 119 | #ifdef HAVE_SETRLIMIT |
| 120 | |
| 121 | typedef struct xlimit { |
| 122 | #define R(r, n) struct rlimit n; |
| 123 | #include "rlimits.h" |
| 124 | } xlimit; |
| 125 | |
| 126 | #endif |
| 127 | |
| 128 | /* --- Environment variable modifications --- */ |
| 129 | |
| 130 | typedef struct xenv { |
| 131 | struct xenv *next; |
| 132 | unsigned act; |
| 133 | char *name; |
| 134 | char *value; |
| 135 | } xenv; |
| 136 | |
| 137 | #define XEA_SET 0u |
| 138 | #define XEA_CLEAR 1u |
| 139 | |
| 140 | /* --- Program options --- */ |
| 141 | |
| 142 | typedef struct xopts { |
| 143 | unsigned ref; |
| 144 | unsigned f; |
| 145 | const char *dir; |
| 146 | const char *root; |
| 147 | uid_t uid; |
| 148 | gid_t gid; |
| 149 | xenv *env; |
| 150 | xenv **etail; |
| 151 | #ifdef HAVE_SETRLIMIT |
| 152 | xlimit xl; |
| 153 | #endif |
| 154 | } xopts; |
| 155 | |
| 156 | #define XF_NOLOG 1u |
| 157 | |
| 158 | /* --- Executable program arguments --- */ |
| 159 | |
| 160 | typedef struct xargs { |
| 161 | unsigned ref; |
| 162 | char *file; |
| 163 | char *argv[1]; |
| 164 | } xargs; |
| 165 | |
| 166 | #define XARGS_SZ(n) (sizeof(xargs) + sizeof(char *) * (n)) |
| 167 | |
| 168 | /* --- Executable endpoints --- */ |
| 169 | |
| 170 | typedef struct xept { |
| 171 | endpt e; |
| 172 | struct xept *next, *prev; |
| 173 | pid_t kid; |
| 174 | endpt *f; |
| 175 | char *desc; |
| 176 | int st; |
| 177 | xargs *xa; |
| 178 | xopts *xo; |
| 179 | selbuf err; |
| 180 | } xept; |
| 181 | |
| 182 | #define XEF_CLOSE 16u |
| 183 | #define XEF_EXIT 32u |
| 184 | |
| 185 | /* --- Executable program data --- */ |
| 186 | |
| 187 | typedef struct xdata { |
| 188 | xargs *xa; |
| 189 | xopts *xo; |
| 190 | } xdata; |
| 191 | |
| 192 | /* --- Executable source block --- */ |
| 193 | |
| 194 | typedef struct xsource { |
| 195 | source s; |
| 196 | xdata x; |
| 197 | } xsource; |
| 198 | |
| 199 | /* --- Executable target block --- */ |
| 200 | |
| 201 | typedef struct xtarget { |
| 202 | target t; |
| 203 | xdata x; |
| 204 | } xtarget; |
| 205 | |
| 206 | /*----- Static variables --------------------------------------------------*/ |
| 207 | |
| 208 | static xopts exec_opts = { 1, 0, 0, 0, -1, -1, 0, &exec_opts.env }; |
| 209 | static xept *xept_list; |
| 210 | static sig xept_sig; |
| 211 | static sym_table env; |
| 212 | |
| 213 | /*----- Fiddling about with resource limits -------------------------------*/ |
| 214 | |
| 215 | #ifdef HAVE_SETRLIMIT |
| 216 | |
| 217 | /* --- Table mapping user-level names to OS interface bits --- */ |
| 218 | |
| 219 | typedef struct rlimit_ent { |
| 220 | const char *name; |
| 221 | const char *rname; |
| 222 | int r; |
| 223 | size_t off; |
| 224 | } rlimit_ent; |
| 225 | |
| 226 | static rlimit_ent rlimits[] = { |
| 227 | #define R(r, n) { #n, #r, r, offsetof(xlimit, n) }, |
| 228 | #include "rlimits.h" |
| 229 | { 0, 0, 0, 0 } |
| 230 | }; |
| 231 | |
| 232 | #define RLIMIT(xl, o) ((struct rlimit *)((char *)(xl) + (o))) |
| 233 | |
| 234 | /* --- @rlimit_get@ --- * |
| 235 | * |
| 236 | * Arguments: @xlimit *xl@ = pointer to limit structure |
| 237 | * |
| 238 | * Returns: --- |
| 239 | * |
| 240 | * Use: Initializes a limit structure from the current limits. |
| 241 | */ |
| 242 | |
| 243 | static void rlimit_get(xlimit *xl) |
| 244 | { |
| 245 | rlimit_ent *r; |
| 246 | |
| 247 | for (r = rlimits; r->name; r++) { |
| 248 | if (getrlimit(r->r, RLIMIT(xl, r->off))) { |
| 249 | moan("couldn't read %s: %s", r->rname, strerror(errno)); |
| 250 | _exit(1); |
| 251 | } |
| 252 | } |
| 253 | } |
| 254 | |
| 255 | /* --- @rlimit_set@ --- * |
| 256 | * |
| 257 | * Arguments: @xlimit *xl@ = pointer to limit structure |
| 258 | * |
| 259 | * Returns: --- |
| 260 | * |
| 261 | * Use: Sets resource limits from the supplied limits structure. |
| 262 | */ |
| 263 | |
| 264 | static void rlimit_set(xlimit *xl) |
| 265 | { |
| 266 | rlimit_ent *r; |
| 267 | |
| 268 | for (r = rlimits; r->name; r++) { |
| 269 | if (setrlimit(r->r, RLIMIT(xl, r->off))) { |
| 270 | moan("couldn't set %s: %s", r->rname, strerror(errno)); |
| 271 | _exit(1); |
| 272 | } |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | /* --- @rlimit_option@ --- */ |
| 277 | |
| 278 | static int rlimit_option(xlimit *xl, scanner *sc) |
| 279 | { |
| 280 | CONF_BEGIN(sc, "rlimit", "resource limit") |
| 281 | enum { w_soft, w_hard, w_both } which = w_both; |
| 282 | rlimit_ent *chosen; |
| 283 | struct rlimit *rl; |
| 284 | long v; |
| 285 | |
| 286 | /* --- Find out which resource is being fiddled --- */ |
| 287 | |
| 288 | { |
| 289 | rlimit_ent *r; |
| 290 | |
| 291 | chosen = 0; |
| 292 | for (r = rlimits; r->name; r++) { |
| 293 | if (strncmp(sc->d.buf, r->name, sc->d.len) == 0) { |
| 294 | if (r->name[sc->d.len] == 0) { |
| 295 | chosen = r; |
| 296 | break; |
| 297 | } else if (chosen) |
| 298 | error(sc, "ambiguous resource limit name `%s'", sc->d.buf); |
| 299 | else if (CONF_QUAL) |
| 300 | chosen = r; |
| 301 | } |
| 302 | } |
| 303 | if (!chosen) |
| 304 | CONF_REJECT; |
| 305 | token(sc); |
| 306 | rl = RLIMIT(xl, chosen->off); |
| 307 | } |
| 308 | |
| 309 | /* --- Look for hard or soft restrictions --- */ |
| 310 | |
| 311 | { |
| 312 | int i; |
| 313 | if (sc->t == '.') |
| 314 | token(sc); |
| 315 | if (sc->t == CTOK_WORD) { |
| 316 | if ((i = conf_enum(sc, "soft,hard", |
| 317 | ENUM_ABBREV | ENUM_NONE, "limit type")) != -1) |
| 318 | which = i; |
| 319 | } |
| 320 | } |
| 321 | |
| 322 | /* --- Now read the new value --- */ |
| 323 | |
| 324 | if (sc->t == '=') |
| 325 | token(sc); |
| 326 | if (sc->t != CTOK_WORD) |
| 327 | error(sc, "parse error, expected limit value"); |
| 328 | |
| 329 | if (conf_enum(sc, "unlimited,infinity", |
| 330 | ENUM_ABBREV | ENUM_NONE, "limit value") > -1) |
| 331 | v = RLIM_INFINITY; |
| 332 | else { |
| 333 | char *p; |
| 334 | |
| 335 | v = strtol(sc->d.buf, &p, 0); |
| 336 | if (p == sc->d.buf) |
| 337 | error(sc, "parse error, invalid limit value `%s'", sc->d.buf); |
| 338 | switch (tolower((unsigned char)*p)) { |
| 339 | case 0: break; |
| 340 | case 'b': v *= 512; break; |
| 341 | case 'g': v *= 1024; |
| 342 | case 'm': v *= 1024; |
| 343 | case 'k': v *= 1024; break; |
| 344 | default: error(sc, "parse error, invalid limit scale `%c'", *p); |
| 345 | } |
| 346 | token(sc); |
| 347 | } |
| 348 | |
| 349 | /* --- Store the limit value away --- */ |
| 350 | |
| 351 | switch (which) { |
| 352 | case w_both: |
| 353 | rl->rlim_cur = v; |
| 354 | rl->rlim_max = v; |
| 355 | break; |
| 356 | case w_soft: |
| 357 | if (v > rl->rlim_max) |
| 358 | error(sc, "soft limit %l exceeds hard limit %l for %s", |
| 359 | v, rl->rlim_max, chosen->rname); |
| 360 | rl->rlim_cur = v; |
| 361 | break; |
| 362 | case w_hard: |
| 363 | rl->rlim_max = v; |
| 364 | if (rl->rlim_cur > v) |
| 365 | rl->rlim_cur = v; |
| 366 | break; |
| 367 | } |
| 368 | |
| 369 | CONF_ACCEPT; |
| 370 | CONF_END; |
| 371 | } |
| 372 | |
| 373 | #endif |
| 374 | |
| 375 | /*----- Environment fiddling ----------------------------------------------*/ |
| 376 | |
| 377 | /* --- @xenv_option@ --- * |
| 378 | * |
| 379 | * Arguments: @xopts *xo@ = pointer to options block |
| 380 | * @scanner *sc@ = pointer to scanner |
| 381 | * |
| 382 | * Returns: Nonzero if claimed |
| 383 | * |
| 384 | * Use: Parses environment variable assignments. |
| 385 | */ |
| 386 | |
| 387 | static int xenv_option(xopts *xo, scanner *sc) |
| 388 | { |
| 389 | CONF_BEGIN(sc, "env", "environment") |
| 390 | xenv *xe; |
| 391 | |
| 392 | /* --- Unset a variable --- */ |
| 393 | |
| 394 | if (strcmp(sc->d.buf, "unset") == 0) { |
| 395 | token(sc); |
| 396 | if (sc->t != CTOK_WORD) |
| 397 | error(sc, "parse error, expected environment variable name"); |
| 398 | xe = CREATE(xenv); |
| 399 | xe->name = xstrdup(sc->d.buf); |
| 400 | xe->value = 0; |
| 401 | xe->act = XEA_SET; |
| 402 | token(sc); |
| 403 | goto link; |
| 404 | } |
| 405 | |
| 406 | /* --- Clear the entire environment --- */ |
| 407 | |
| 408 | if (strcmp(sc->d.buf, "clear") == 0) { |
| 409 | token(sc); |
| 410 | xe = CREATE(xenv); |
| 411 | xe->act = XEA_CLEAR; |
| 412 | goto link; |
| 413 | } |
| 414 | |
| 415 | /* --- Allow `set' to be omitted if there's a prefix --- */ |
| 416 | |
| 417 | if (strcmp(sc->d.buf, "set") == 0) |
| 418 | token(sc); |
| 419 | else if (!CONF_QUAL) |
| 420 | CONF_REJECT; |
| 421 | |
| 422 | /* --- Set a variable --- */ |
| 423 | |
| 424 | if (sc->t != CTOK_WORD) |
| 425 | error(sc, "parse error, expected environment variable name"); |
| 426 | xe = CREATE(xenv); |
| 427 | xe->name = xstrdup(sc->d.buf); |
| 428 | token(sc); |
| 429 | if (sc->t == '=') |
| 430 | token(sc); |
| 431 | if (sc->t != CTOK_WORD) |
| 432 | error(sc, "parse error, expected environment variable value"); |
| 433 | xe->value = xstrdup(sc->d.buf); |
| 434 | xe->act = XEA_SET; |
| 435 | token(sc); |
| 436 | goto link; |
| 437 | |
| 438 | link: |
| 439 | xe->next = 0; |
| 440 | *xo->etail = xe; |
| 441 | xo->etail = &xe->next; |
| 442 | CONF_ACCEPT; |
| 443 | |
| 444 | /* --- Nothing else to try --- */ |
| 445 | |
| 446 | CONF_END; |
| 447 | } |
| 448 | |
| 449 | /* --- @xenv_apply@ --- * |
| 450 | * |
| 451 | * Arguments: @xenv *xe@ = pointer to a variable change list |
| 452 | * |
| 453 | * Returns: --- |
| 454 | * |
| 455 | * Use: Modifies the environment (in @env@) according to the list. |
| 456 | */ |
| 457 | |
| 458 | static void xenv_apply(xenv *xe) |
| 459 | { |
| 460 | while (xe) { |
| 461 | switch (xe->act) { |
| 462 | case XEA_SET: |
| 463 | env_put(&env, xe->name, xe->value); |
| 464 | break; |
| 465 | case XEA_CLEAR: |
| 466 | env_destroy(&env); |
| 467 | sym_create(&env); |
| 468 | break; |
| 469 | } |
| 470 | xe = xe->next; |
| 471 | } |
| 472 | } |
| 473 | |
| 474 | /* --- @xenv_destroy@ --- * |
| 475 | * |
| 476 | * Arguments: @xenv *xe@ = pointer to a variable change list |
| 477 | * |
| 478 | * Returns: --- |
| 479 | * |
| 480 | * Use: Frees the memory used by an environment variable change list. |
| 481 | */ |
| 482 | |
| 483 | static void xenv_destroy(xenv *xe) |
| 484 | { |
| 485 | while (xe) { |
| 486 | xenv *xxe = xe; |
| 487 | xe = xe->next; |
| 488 | xfree(xxe->name); |
| 489 | if (xxe->value) |
| 490 | xfree(xxe->value); |
| 491 | DESTROY(xxe); |
| 492 | } |
| 493 | } |
| 494 | |
| 495 | /*----- Miscellaneous good things -----------------------------------------*/ |
| 496 | |
| 497 | /* --- @x_tidy@ --- * |
| 498 | * |
| 499 | * Arguments: @xargs *xa@ = pointer to an arguments block |
| 500 | * @xopts *xo@ = pointer to an options block |
| 501 | * |
| 502 | * Returns: --- |
| 503 | * |
| 504 | * Use: Releases a reference to argument and options blocks. |
| 505 | */ |
| 506 | |
| 507 | static void x_tidy(xargs *xa, xopts *xo) |
| 508 | { |
| 509 | xa->ref--; |
| 510 | if (!xa->ref) |
| 511 | xfree(xa); |
| 512 | |
| 513 | xo->ref--; |
| 514 | if (!xo->ref) { |
| 515 | xenv_destroy(xo->env); |
| 516 | DESTROY(xo); |
| 517 | } |
| 518 | } |
| 519 | |
| 520 | /*----- Executable endpoints ----------------------------------------------*/ |
| 521 | |
| 522 | /* --- @attach@ --- */ |
| 523 | |
| 524 | static void xept_error(char */*p*/, size_t /*len*/, void */*v*/); |
| 525 | |
| 526 | static void xept_attach(endpt *e, reffd *in, reffd *out) |
| 527 | { |
| 528 | xept *xe = (xept *)e; |
| 529 | pid_t kid; |
| 530 | int fd[2]; |
| 531 | |
| 532 | /* --- Make a pipe for standard error --- */ |
| 533 | |
| 534 | if (pipe(fd)) { |
| 535 | fw_log(-1, "[%s] couldn't create pipe: %s", xe->desc, strerror(errno)); |
| 536 | return; |
| 537 | } |
| 538 | fdflags(fd[0], O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
| 539 | |
| 540 | /* --- Fork a child, and handle an error if there was one --- */ |
| 541 | |
| 542 | if ((kid = fork()) == -1) { |
| 543 | fw_log(-1, "[%s] couldn't fork: %s", xe->desc, strerror(errno)); |
| 544 | close(fd[0]); |
| 545 | close(fd[1]); |
| 546 | return; |
| 547 | } |
| 548 | |
| 549 | /* --- Do the child thing --- */ |
| 550 | |
| 551 | if (kid == 0) { |
| 552 | xopts *xo = xe->xo; |
| 553 | |
| 554 | /* --- Fiddle with the file descriptors --- * |
| 555 | * |
| 556 | * Attach the other endpoint's descriptors to standard input and output. |
| 557 | * Attach my pipe to standard error. Mark everything as blocking and |
| 558 | * not-to-be-closed-on-exec at this end. |
| 559 | */ |
| 560 | |
| 561 | close(fd[0]); |
| 562 | if (dup2(in->fd, STDIN_FILENO) < 0 || |
| 563 | dup2(out->fd, STDOUT_FILENO) < 0 || |
| 564 | dup2(fd[1], STDERR_FILENO) < 0) { |
| 565 | moan("couldn't manipulate file descriptors: %s", strerror(errno)); |
| 566 | _exit(1); |
| 567 | } |
| 568 | |
| 569 | if (in->fd > 2) |
| 570 | close(in->fd); |
| 571 | if (out->fd > 2) |
| 572 | close(out->fd); |
| 573 | |
| 574 | fdflags(STDIN_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0); |
| 575 | fdflags(STDOUT_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0); |
| 576 | fdflags(STDERR_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0); |
| 577 | |
| 578 | /* --- First of all set the @chroot@ prison --- */ |
| 579 | |
| 580 | if (xo->root && chroot(xo->root)) { |
| 581 | moan("couldn't set `%s' as filesystem root: %s", |
| 582 | xo->root, strerror(errno)); |
| 583 | _exit(1); |
| 584 | } |
| 585 | |
| 586 | /* --- Now set the current directory --- */ |
| 587 | |
| 588 | if (xo->dir ? chdir(xo->dir) : xo->root ? chdir("/") : 0) { |
| 589 | moan("couldn't set `%s' as current directory: %s", |
| 590 | xo->dir ? xo->dir : "/", strerror(errno)); |
| 591 | _exit(1); |
| 592 | } |
| 593 | |
| 594 | /* --- Set the resource limits --- */ |
| 595 | |
| 596 | #ifdef HAVE_SETRLIMIT |
| 597 | rlimit_set(&xo->xl); |
| 598 | #endif |
| 599 | |
| 600 | /* --- Set group id --- */ |
| 601 | |
| 602 | if (xo->gid != (gid_t)-1) { |
| 603 | if (setgid(xo->gid)) { |
| 604 | moan("couldn't set gid %i: %s", xo->gid, strerror(errno)); |
| 605 | _exit(1); |
| 606 | } |
| 607 | #ifdef HAVE_SETGROUPS |
| 608 | if (setgroups(1, &xo->gid)) |
| 609 | moan("warning: couldn't set group list to %i: %s", xo->gid, |
| 610 | strerror(errno)); |
| 611 | #endif |
| 612 | } |
| 613 | |
| 614 | /* --- Set uid --- */ |
| 615 | |
| 616 | if (xo->uid != (uid_t)-1) { |
| 617 | if (setuid(xo->uid)) { |
| 618 | moan("couldn't set uid %i: %s", xo->uid, strerror(errno)); |
| 619 | _exit(1); |
| 620 | } |
| 621 | } |
| 622 | |
| 623 | /* --- Play with signal dispositions --- */ |
| 624 | |
| 625 | signal(SIGPIPE, SIG_DFL); |
| 626 | |
| 627 | /* --- Fiddle with the environment --- */ |
| 628 | |
| 629 | xenv_apply(exec_opts.env); |
| 630 | xenv_apply(xe->xo->env); |
| 631 | environ = env_export(&env); |
| 632 | |
| 633 | /* --- Run the program --- */ |
| 634 | |
| 635 | execvp(xe->xa->file, xe->xa->argv); |
| 636 | moan("couldn't execute `%s': %s", xe->xa->file, strerror(errno)); |
| 637 | _exit(127); |
| 638 | } |
| 639 | |
| 640 | /* --- The child's done; see to the parent --- */ |
| 641 | |
| 642 | xe->kid = kid; |
| 643 | selbuf_init(&xe->err, sel, fd[0], xept_error, xe); |
| 644 | close(fd[1]); |
| 645 | xe->next = xept_list; |
| 646 | xe->prev = 0; |
| 647 | if (xept_list) |
| 648 | xept_list->prev = xe; |
| 649 | xept_list = xe; |
| 650 | if (!(xe->xo->f & XF_NOLOG)) |
| 651 | fw_log(-1, "[%s] started with pid %i", xe->desc, kid); |
| 652 | fw_inc(); |
| 653 | return; |
| 654 | } |
| 655 | |
| 656 | /* --- @xept_file@ --- */ |
| 657 | |
| 658 | static void xept_file(endpt *e, endpt *f) |
| 659 | { |
| 660 | xept *xe = (xept *)e; |
| 661 | xe->f = f; |
| 662 | } |
| 663 | |
| 664 | /* --- @xept_close@ --- */ |
| 665 | |
| 666 | static void xept_close(endpt *e) |
| 667 | { |
| 668 | xept *xe = (xept *)e; |
| 669 | if (xe->kid == -1) { |
| 670 | if (xe->f) |
| 671 | xe->f->ops->close(xe->f); |
| 672 | x_tidy(xe->xa, xe->xo); |
| 673 | DESTROY(xe); |
| 674 | fw_dec(); |
| 675 | } |
| 676 | } |
| 677 | |
| 678 | /* --- @xept_destroy@ --- */ |
| 679 | |
| 680 | static void xept_destroy(xept *xe) |
| 681 | { |
| 682 | /* --- First emit the news about the process --- */ |
| 683 | |
| 684 | if (xe->xo->f & XF_NOLOG) |
| 685 | /* Nothin' doin' */; |
| 686 | else if (WIFEXITED(xe->st)) { |
| 687 | if (WEXITSTATUS(xe->st) == 0) |
| 688 | fw_log(-1, "[%s] pid %i exited successfully", xe->desc, xe->kid); |
| 689 | else { |
| 690 | fw_log(-1, "[%s] pid %i failed: status %i", |
| 691 | xe->desc, xe->kid, WEXITSTATUS(xe->st)); |
| 692 | } |
| 693 | } else if (WIFSIGNALED(xe->st)) { |
| 694 | const char *s; |
| 695 | #ifdef HAVE_STRSIGNAL |
| 696 | s = strsignal(WTERMSIG(xe->st)); |
| 697 | #elif HAVE__SYS_SIGLIST |
| 698 | s = _sys_siglist[WTERMSIG(xe->st)]; |
| 699 | #else |
| 700 | char buf[32]; |
| 701 | sprintf(buf, "signal %i", WTERMSIG(xe->st)); |
| 702 | s = buf; |
| 703 | #endif |
| 704 | fw_log(-1, "[%s] pid %i failed: %s", xe->desc, xe->kid, s); |
| 705 | } else |
| 706 | fw_log(-1, "[%s] pid %i failed: unrecognized status", xe->desc, xe->kid); |
| 707 | |
| 708 | /* --- Free up the parent-side resources --- */ |
| 709 | |
| 710 | if (xe->next) |
| 711 | xe->next->prev = xe->prev; |
| 712 | if (xe->prev) |
| 713 | xe->prev->next = xe->next; |
| 714 | else |
| 715 | xept_list = xe->next; |
| 716 | |
| 717 | xfree(xe->desc); |
| 718 | if (xe->f) |
| 719 | xe->f->ops->close(xe->f); |
| 720 | x_tidy(xe->xa, xe->xo); |
| 721 | fw_dec(); |
| 722 | DESTROY(xe); |
| 723 | } |
| 724 | |
| 725 | /* --- @xept_chld@ --- * |
| 726 | * |
| 727 | * Arguments: @int n@ = signal number |
| 728 | * @void *p@ = uninteresting pointer |
| 729 | * |
| 730 | * Returns: --- |
| 731 | * |
| 732 | * Use: Deals with child death situations. |
| 733 | */ |
| 734 | |
| 735 | static void xept_chld(int n, void *p) |
| 736 | { |
| 737 | pid_t kid; |
| 738 | int st; |
| 739 | |
| 740 | while ((kid = waitpid(-1, &st, WNOHANG)) > 0) { |
| 741 | xept *xe = xept_list; |
| 742 | while (xe) { |
| 743 | xept *xxe = xe; |
| 744 | xe = xe->next; |
| 745 | if (kid == xxe->kid) { |
| 746 | xxe->st = st; |
| 747 | xxe->e.f |= XEF_EXIT; |
| 748 | if (xxe->e.f & XEF_CLOSE) |
| 749 | xept_destroy(xxe); |
| 750 | break; |
| 751 | } |
| 752 | } |
| 753 | } |
| 754 | } |
| 755 | |
| 756 | /* --- @xept_error@ --- * |
| 757 | * |
| 758 | * Arguments: @char *p@ = pointer to string read from stderr |
| 759 | * @size_t len@ = length of the string |
| 760 | * @void *v@ = pointer to by endpoint |
| 761 | * |
| 762 | * Returns: --- |
| 763 | * |
| 764 | * Use: Handles error reports from a child process. |
| 765 | */ |
| 766 | |
| 767 | static void xept_error(char *p, size_t len, void *v) |
| 768 | { |
| 769 | xept *xe = v; |
| 770 | if (p) |
| 771 | fw_log(-1, "[%s] pid %i: %s", xe->desc, xe->kid, p); |
| 772 | else { |
| 773 | close(xe->err.reader.fd); |
| 774 | selbuf_destroy(&xe->err); |
| 775 | xe->e.f |= XEF_CLOSE; |
| 776 | if (xe->e.f & XEF_EXIT) |
| 777 | xept_destroy(xe); |
| 778 | } |
| 779 | } |
| 780 | |
| 781 | /* --- Endpoint operations --- */ |
| 782 | |
| 783 | static endpt_ops xept_ops = { xept_attach, xept_file, 0, xept_close }; |
| 784 | |
| 785 | /*----- General operations on sources and targets -------------------------*/ |
| 786 | |
| 787 | /* --- @exec_init@ --- * |
| 788 | * |
| 789 | * Arguments: --- |
| 790 | * |
| 791 | * Returns: --- |
| 792 | * |
| 793 | * Use: Initializes the executable problem source and target. |
| 794 | */ |
| 795 | |
| 796 | void exec_init(void) |
| 797 | { |
| 798 | #ifdef HAVE_SETRLIMIT |
| 799 | rlimit_get(&exec_opts.xl); |
| 800 | #endif |
| 801 | sig_add(&xept_sig, SIGCHLD, xept_chld, 0); |
| 802 | sym_create(&env); |
| 803 | env_import(&env, environ); |
| 804 | } |
| 805 | |
| 806 | /* --- @exec_option@ --- */ |
| 807 | |
| 808 | static int exec_option(xdata *x, scanner *sc) |
| 809 | { |
| 810 | xopts *xo = x ? x->xo : &exec_opts; |
| 811 | |
| 812 | CONF_BEGIN(sc, "exec", "executable"); |
| 813 | |
| 814 | /* --- Logging settings --- */ |
| 815 | |
| 816 | if (strcmp(sc->d.buf, "logging") == 0 || |
| 817 | strcmp(sc->d.buf, "log") == 0) { |
| 818 | token(sc); |
| 819 | if (sc->t == '=') |
| 820 | token(sc); |
| 821 | if (conf_enum(sc, "no,yes", ENUM_ABBREV, "logging status")) |
| 822 | xo->f &= ~XF_NOLOG; |
| 823 | else |
| 824 | xo->f |= XF_NOLOG; |
| 825 | CONF_ACCEPT; |
| 826 | } |
| 827 | |
| 828 | /* --- Current directory setting --- * |
| 829 | * |
| 830 | * Lots of possibilities to guard against possible brainoes. |
| 831 | */ |
| 832 | |
| 833 | if (strcmp(sc->d.buf, "dir") == 0 || |
| 834 | strcmp(sc->d.buf, "cd") == 0 || |
| 835 | strcmp(sc->d.buf, "chdir") == 0 || |
| 836 | strcmp(sc->d.buf, "cwd") == 0) { |
| 837 | dstr d = DSTR_INIT; |
| 838 | token(sc); |
| 839 | if (sc->t == '=') |
| 840 | token(sc); |
| 841 | conf_name(sc, '/', &d); |
| 842 | xo->dir = xstrdup(d.buf); |
| 843 | dstr_destroy(&d); |
| 844 | CONF_ACCEPT; |
| 845 | } |
| 846 | |
| 847 | /* --- Set a chroot prison --- */ |
| 848 | |
| 849 | if (strcmp(sc->d.buf, "root") == 0 || |
| 850 | strcmp(sc->d.buf, "chroot") == 0) { |
| 851 | dstr d = DSTR_INIT; |
| 852 | token(sc); |
| 853 | if (sc->t == '=') |
| 854 | token(sc); |
| 855 | conf_name(sc, '/', &d); |
| 856 | xo->root = xstrdup(d.buf); |
| 857 | dstr_destroy(&d); |
| 858 | CONF_ACCEPT; |
| 859 | } |
| 860 | |
| 861 | /* --- Set the target user id --- */ |
| 862 | |
| 863 | if (strcmp(sc->d.buf, "uid") == 0 || |
| 864 | strcmp(sc->d.buf, "user") == 0) { |
| 865 | token(sc); |
| 866 | if (sc->t == '=') |
| 867 | token(sc); |
| 868 | if (sc->t != CTOK_WORD) |
| 869 | error(sc, "parse error, expected user name or uid"); |
| 870 | if (isdigit((unsigned char)*sc->d.buf)) |
| 871 | xo->uid = atoi(sc->d.buf); |
| 872 | else { |
| 873 | struct passwd *pw = getpwnam(sc->d.buf); |
| 874 | if (!pw) |
| 875 | error(sc, "unknown user name `%s'", sc->d.buf); |
| 876 | xo->uid = pw->pw_uid; |
| 877 | } |
| 878 | token(sc); |
| 879 | CONF_ACCEPT; |
| 880 | } |
| 881 | |
| 882 | /* --- Set the target group id --- */ |
| 883 | |
| 884 | if (strcmp(sc->d.buf, "gid") == 0 || |
| 885 | strcmp(sc->d.buf, "group") == 0) { |
| 886 | token(sc); |
| 887 | if (sc->t == '=') |
| 888 | token(sc); |
| 889 | if (sc->t != CTOK_WORD) |
| 890 | error(sc, "parse error, expected group name or gid"); |
| 891 | if (isdigit((unsigned char)*sc->d.buf)) |
| 892 | xo->gid = atoi(sc->d.buf); |
| 893 | else { |
| 894 | struct group *gr = getgrnam(sc->d.buf); |
| 895 | if (!gr) |
| 896 | error(sc, "unknown user name `%s'", sc->d.buf); |
| 897 | xo->gid = gr->gr_gid; |
| 898 | } |
| 899 | token(sc); |
| 900 | CONF_ACCEPT; |
| 901 | } |
| 902 | |
| 903 | /* --- Now try resource limit settings --- */ |
| 904 | |
| 905 | #ifdef HAVE_SETRLIMIT |
| 906 | if (rlimit_option(&xo->xl, sc)) |
| 907 | CONF_ACCEPT; |
| 908 | #endif |
| 909 | |
| 910 | /* --- And then environment settings --- */ |
| 911 | |
| 912 | if (xenv_option(xo, sc)) |
| 913 | CONF_ACCEPT; |
| 914 | |
| 915 | /* --- Nothing found --- */ |
| 916 | |
| 917 | CONF_END; |
| 918 | } |
| 919 | |
| 920 | /* --- @exec_desc@ --- */ |
| 921 | |
| 922 | static void exec_desc(xdata *x, dstr *d) |
| 923 | { |
| 924 | char **p; |
| 925 | char sep = '['; |
| 926 | dstr_puts(d, "exec "); |
| 927 | if (strcmp(x->xa->file, x->xa->argv[0]) != 0) { |
| 928 | dstr_puts(d, x->xa->file); |
| 929 | dstr_putc(d, ' '); |
| 930 | } |
| 931 | for (p = x->xa->argv; *p; p++) { |
| 932 | dstr_putc(d, sep); |
| 933 | dstr_puts(d, *p); |
| 934 | sep = ' '; |
| 935 | } |
| 936 | dstr_putc(d, ']'); |
| 937 | dstr_putz(d); |
| 938 | } |
| 939 | |
| 940 | /* --- @exec_read@ --- */ |
| 941 | |
| 942 | static void exec_read(xdata *x, scanner *sc) |
| 943 | { |
| 944 | size_t base = 0; |
| 945 | dstr d = DSTR_INIT; |
| 946 | xargs *xa; |
| 947 | |
| 948 | /* --- Read the first word --- * |
| 949 | * |
| 950 | * This is either a shell command or the actual program to run. |
| 951 | */ |
| 952 | |
| 953 | if (sc->t == CTOK_WORD) { |
| 954 | dstr_putd(&d, &sc->d); d.len++; |
| 955 | base = d.len; |
| 956 | token(sc); |
| 957 | } |
| 958 | |
| 959 | /* --- See if there's a list of arguments --- * |
| 960 | * |
| 961 | * If not, then the thing I saw was a shell command, so build the proper |
| 962 | * arguments for that. |
| 963 | */ |
| 964 | |
| 965 | if (sc->t != '[') { |
| 966 | char *p; |
| 967 | if (!base) |
| 968 | error(sc, "parse error, expected shell command or argument list"); |
| 969 | xa = xmalloc(XARGS_SZ(3) + 8 + 3 + d.len); |
| 970 | p = (char *)(xa->argv + 4); |
| 971 | xa->ref = 1; |
| 972 | xa->file = p; |
| 973 | xa->argv[0] = p; memcpy(p, "/bin/sh", 8); p += 8; |
| 974 | xa->argv[1] = p; memcpy(p, "-c", 3); p += 3; |
| 975 | xa->argv[2] = p; memcpy(p, d.buf, d.len); p += d.len; |
| 976 | xa->argv[3] = 0; |
| 977 | } |
| 978 | |
| 979 | /* --- Snarf in a list of arguments --- */ |
| 980 | |
| 981 | else { |
| 982 | int argc = 0; |
| 983 | char *p, *q; |
| 984 | char **v; |
| 985 | |
| 986 | /* --- Strip off the leading `[' --- * |
| 987 | * |
| 988 | * Allow various handy filename characters to be entered without quoting. |
| 989 | */ |
| 990 | |
| 991 | conf_undelim(sc, "=:/.", "=:/."); |
| 992 | token(sc); |
| 993 | |
| 994 | /* --- Read a sequence of arguments --- */ |
| 995 | |
| 996 | while (sc->t == CTOK_WORD) { |
| 997 | dstr_putd(&d, &sc->d); d.len++; |
| 998 | token(sc); |
| 999 | argc++; |
| 1000 | } |
| 1001 | conf_undelim(sc, 0, 0); |
| 1002 | |
| 1003 | /* --- Expect the closing `]' --- */ |
| 1004 | |
| 1005 | if (sc->t != ']') |
| 1006 | error(sc, "parse error, missing `]'"); |
| 1007 | token(sc); |
| 1008 | |
| 1009 | /* --- If there are no arguments, whinge --- */ |
| 1010 | |
| 1011 | if (!argc) |
| 1012 | error(sc, "must specify at least one argument"); |
| 1013 | |
| 1014 | /* --- Allocate a lump of memory for the array --- */ |
| 1015 | |
| 1016 | xa = xmalloc(XARGS_SZ(argc) + d.len); |
| 1017 | xa->ref = 1; |
| 1018 | v = xa->argv; |
| 1019 | p = (char *)(v + argc + 1); |
| 1020 | memcpy(p, d.buf, d.len); |
| 1021 | q = p + d.len; |
| 1022 | xa->file = p; |
| 1023 | p += base; |
| 1024 | |
| 1025 | /* --- Start dumping addresses into the @argv@ array --- */ |
| 1026 | |
| 1027 | for (;;) { |
| 1028 | *v++ = p; |
| 1029 | while (*p++ && p < q) |
| 1030 | ; |
| 1031 | if (p >= q) |
| 1032 | break; |
| 1033 | } |
| 1034 | *v++ = 0; |
| 1035 | } |
| 1036 | |
| 1037 | /* --- Do some other setting up --- */ |
| 1038 | |
| 1039 | dstr_destroy(&d); |
| 1040 | x->xa = xa; |
| 1041 | x->xo = CREATE(xopts); |
| 1042 | *x->xo = exec_opts; |
| 1043 | x->xo->ref = 1; |
| 1044 | return; |
| 1045 | } |
| 1046 | |
| 1047 | /* --- @exec_endpt@ --- */ |
| 1048 | |
| 1049 | static endpt *exec_endpt(xdata *x, const char *desc) |
| 1050 | { |
| 1051 | xept *xe = CREATE(xept); |
| 1052 | xe->e.ops = &xept_ops; |
| 1053 | xe->e.other = 0; |
| 1054 | xe->e.t = 0; |
| 1055 | xe->e.f = 0; |
| 1056 | xe->xa = x->xa; xe->xa->ref++; |
| 1057 | xe->xo = x->xo; xe->xo->ref++; |
| 1058 | xe->kid = -1; |
| 1059 | xe->f = 0; |
| 1060 | xe->desc = xstrdup(desc); |
| 1061 | return (&xe->e); |
| 1062 | } |
| 1063 | |
| 1064 | /* --- @exec_destroy@ --- */ |
| 1065 | |
| 1066 | static void exec_destroy(xdata *x) |
| 1067 | { |
| 1068 | x_tidy(x->xa, x->xo); |
| 1069 | } |
| 1070 | |
| 1071 | /*----- Source definition -------------------------------------------------*/ |
| 1072 | |
| 1073 | /* --- @option@ --- */ |
| 1074 | |
| 1075 | static int xsource_option(source *s, scanner *sc) |
| 1076 | { |
| 1077 | xsource *xs = (xsource *)s; |
| 1078 | return (exec_option(xs ? &xs->x : 0, sc)); |
| 1079 | } |
| 1080 | |
| 1081 | /* --- @read@ --- */ |
| 1082 | |
| 1083 | static source *xsource_read(scanner *sc) |
| 1084 | { |
| 1085 | xsource *xs; |
| 1086 | |
| 1087 | if (!conf_prefix(sc, "exec")) |
| 1088 | return (0); |
| 1089 | xs = CREATE(xsource); |
| 1090 | xs->s.ops = &xsource_ops; |
| 1091 | xs->s.desc = 0; |
| 1092 | exec_read(&xs->x, sc); |
| 1093 | return (&xs->s); |
| 1094 | } |
| 1095 | |
| 1096 | /* --- @attach@ --- */ |
| 1097 | |
| 1098 | static void xsource_destroy(source */*s*/); |
| 1099 | |
| 1100 | static void xsource_attach(source *s, scanner *sc, target *t) |
| 1101 | { |
| 1102 | xsource *xs = (xsource *)s; |
| 1103 | endpt *e, *ee; |
| 1104 | |
| 1105 | /* --- Set up the source description string --- */ |
| 1106 | |
| 1107 | { |
| 1108 | dstr d = DSTR_INIT; |
| 1109 | exec_desc(&xs->x, &d); |
| 1110 | dstr_puts(&d, " -> "); |
| 1111 | dstr_puts(&d, t->desc); |
| 1112 | xs->s.desc = xstrdup(d.buf); |
| 1113 | dstr_destroy(&d); |
| 1114 | } |
| 1115 | |
| 1116 | /* --- Create the endpoints --- */ |
| 1117 | |
| 1118 | if ((ee = t->ops->create(t, xs->s.desc)) == 0) |
| 1119 | goto tidy; |
| 1120 | if ((e = exec_endpt(&xs->x, xs->s.desc)) == 0) { |
| 1121 | ee->ops->close(ee); |
| 1122 | goto tidy; |
| 1123 | } |
| 1124 | endpt_join(e, ee); |
| 1125 | |
| 1126 | /* --- Dispose of source and target --- */ |
| 1127 | |
| 1128 | tidy: |
| 1129 | t->ops->destroy(t); |
| 1130 | xsource_destroy(&xs->s); |
| 1131 | } |
| 1132 | |
| 1133 | /* --- @destroy@ --- */ |
| 1134 | |
| 1135 | static void xsource_destroy(source *s) |
| 1136 | { |
| 1137 | xsource *xs = (xsource *)s; |
| 1138 | xfree(xs->s.desc); |
| 1139 | exec_destroy(&xs->x); |
| 1140 | DESTROY(xs); |
| 1141 | } |
| 1142 | |
| 1143 | /* --- Executable source operations --- */ |
| 1144 | |
| 1145 | source_ops xsource_ops = { |
| 1146 | "exec", |
| 1147 | xsource_option, xsource_read, xsource_attach, xsource_destroy |
| 1148 | }; |
| 1149 | |
| 1150 | /*----- Exec target description -------------------------------------------*/ |
| 1151 | |
| 1152 | /* --- @option@ --- */ |
| 1153 | |
| 1154 | static int xtarget_option(target *t, scanner *sc) |
| 1155 | { |
| 1156 | xtarget *xt = (xtarget *)t; |
| 1157 | return (exec_option(xt ? &xt->x : 0, sc)); |
| 1158 | } |
| 1159 | |
| 1160 | /* --- @read@ --- */ |
| 1161 | |
| 1162 | static target *xtarget_read(scanner *sc) |
| 1163 | { |
| 1164 | xtarget *xt; |
| 1165 | dstr d = DSTR_INIT; |
| 1166 | |
| 1167 | if (!conf_prefix(sc, "exec")) |
| 1168 | return (0); |
| 1169 | xt = CREATE(xtarget); |
| 1170 | xt->t.ops = &xtarget_ops; |
| 1171 | exec_read(&xt->x, sc); |
| 1172 | exec_desc(&xt->x, &d); |
| 1173 | xt->t.desc = xstrdup(d.buf); |
| 1174 | dstr_destroy(&d); |
| 1175 | return (&xt->t); |
| 1176 | } |
| 1177 | |
| 1178 | /* --- @create@ --- */ |
| 1179 | |
| 1180 | static endpt *xtarget_create(target *t, const char *desc) |
| 1181 | { |
| 1182 | xtarget *xt = (xtarget *)t; |
| 1183 | endpt *e = exec_endpt(&xt->x, desc); |
| 1184 | return (e); |
| 1185 | } |
| 1186 | |
| 1187 | /* --- @destroy@ --- */ |
| 1188 | |
| 1189 | static void xtarget_destroy(target *t) |
| 1190 | { |
| 1191 | xtarget *xt = (xtarget *)t; |
| 1192 | xfree(xt->t.desc); |
| 1193 | exec_destroy(&xt->x); |
| 1194 | DESTROY(xt); |
| 1195 | } |
| 1196 | |
| 1197 | /* --- Exec target operations --- */ |
| 1198 | |
| 1199 | target_ops xtarget_ops = { |
| 1200 | "exec", |
| 1201 | xtarget_option, xtarget_read, 0, xtarget_create, xtarget_destroy |
| 1202 | }; |
| 1203 | |
| 1204 | /*----- That's all, folks -------------------------------------------------*/ |