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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: exec.c,v 1.3 2000/07/01 11:28:52 mdw Exp $ |
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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 $ |
e68b88bf |
32 | * Revision 1.3 2000/07/01 11:28:52 mdw |
33 | * Use new mLib selbuf features. |
34 | * |
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35 | * Revision 1.2 1999/10/22 22:46:17 mdw |
36 | * When a non-file endpoint is attached to a file, keep the file endpoint |
37 | * open until the nonfile is done. This stops socket sources from |
38 | * resetting their connection limits too early. |
39 | * |
48bb1f76 |
40 | * Revision 1.1 1999/07/26 23:33:32 mdw |
41 | * New sources and targets. |
42 | * |
43 | */ |
44 | |
45 | /*----- Header files ------------------------------------------------------*/ |
46 | |
47 | #include "config.h" |
48 | |
49 | #define _GNU_SOURCE |
50 | |
51 | #include <ctype.h> |
52 | #include <errno.h> |
53 | #include <signal.h> |
54 | #include <stdio.h> |
55 | #include <stdlib.h> |
56 | #include <string.h> |
57 | |
58 | #include <sys/types.h> |
59 | #include <sys/stat.h> |
60 | #include <unistd.h> |
61 | #include <fcntl.h> |
62 | #include <sys/wait.h> |
63 | |
64 | #ifdef HAVE_SETRLIMIT |
65 | # include <sys/resource.h> |
66 | #endif |
67 | |
68 | #ifndef DECL_ENVIRON |
69 | extern char **environ; |
70 | #endif |
71 | |
72 | #include <pwd.h> |
73 | #include <grp.h> |
74 | |
75 | #include <syslog.h> |
76 | |
77 | #include <mLib/alloc.h> |
78 | #include <mLib/dstr.h> |
79 | #include <mLib/env.h> |
80 | #include <mLib/fdflags.h> |
81 | #include <mLib/report.h> |
82 | #include <mLib/sel.h> |
83 | #include <mLib/selbuf.h> |
84 | #include <mLib/sig.h> |
85 | #include <mLib/sub.h> |
86 | #include <mLib/sym.h> |
87 | |
88 | #include "conf.h" |
89 | #include "endpt.h" |
90 | #include "exec.h" |
91 | #include "fattr.h" |
92 | #include "fw.h" |
93 | #include "reffd.h" |
94 | #include "scan.h" |
95 | #include "source.h" |
96 | #include "target.h" |
97 | |
98 | /*----- Data structures ---------------------------------------------------*/ |
99 | |
100 | /* --- Resource usage --- */ |
101 | |
102 | #ifdef HAVE_SETRLIMIT |
103 | |
104 | typedef struct xlimit { |
105 | #define R(r, n) struct rlimit n; |
106 | #include "rlimits.h" |
107 | } xlimit; |
108 | |
109 | #endif |
110 | |
111 | /* --- Environment variable modifications --- */ |
112 | |
113 | typedef struct xenv { |
114 | struct xenv *next; |
115 | unsigned act; |
116 | char *name; |
117 | char *value; |
118 | } xenv; |
119 | |
120 | #define XEA_SET 0u |
121 | #define XEA_CLEAR 1u |
122 | |
123 | /* --- Program options --- */ |
124 | |
125 | typedef struct xopts { |
126 | unsigned ref; |
127 | unsigned f; |
128 | const char *dir; |
129 | const char *root; |
130 | uid_t uid; |
131 | gid_t gid; |
132 | xenv *env; |
133 | xenv **etail; |
134 | #ifdef HAVE_SETRLIMIT |
135 | xlimit xl; |
136 | #endif |
137 | } xopts; |
138 | |
139 | #define XF_NOLOG 1u |
140 | |
141 | /* --- Executable program arguments --- */ |
142 | |
143 | typedef struct xargs { |
144 | unsigned ref; |
145 | char *file; |
146 | char *argv[1]; |
147 | } xargs; |
148 | |
149 | #define XARGS_SZ(n) (sizeof(xargs) + sizeof(char *) * (n)) |
150 | |
151 | /* --- Executable endpoints --- */ |
152 | |
153 | typedef struct xept { |
154 | endpt e; |
155 | struct xept *next, *prev; |
156 | pid_t kid; |
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157 | endpt *f; |
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158 | const char *desc; |
159 | int st; |
160 | xargs *xa; |
161 | xopts *xo; |
162 | selbuf err; |
163 | } xept; |
164 | |
165 | #define XEF_CLOSE 16u |
166 | #define XEF_EXIT 32u |
167 | |
168 | /* --- Executable program data --- */ |
169 | |
170 | typedef struct xdata { |
171 | xargs *xa; |
172 | xopts *xo; |
173 | } xdata; |
174 | |
175 | /* --- Executable source block --- */ |
176 | |
177 | typedef struct xsource { |
178 | source s; |
179 | xdata x; |
180 | } xsource; |
181 | |
182 | /* --- Executable target block --- */ |
183 | |
184 | typedef struct xtarget { |
185 | target t; |
186 | xdata x; |
187 | } xtarget; |
188 | |
189 | /*----- Static variables --------------------------------------------------*/ |
190 | |
191 | static xopts exec_opts = { 1, 0, 0, 0, -1, -1, 0, &exec_opts.env }; |
192 | static xept *xept_list; |
193 | static sig xept_sig; |
194 | static sym_table env; |
195 | |
196 | /*----- Fiddling about with resource limits -------------------------------*/ |
197 | |
198 | #ifdef HAVE_SETRLIMIT |
199 | |
200 | /* --- Table mapping user-level names to OS interface bits --- */ |
201 | |
202 | typedef struct rlimit_ent { |
203 | const char *name; |
204 | const char *rname; |
205 | int r; |
206 | size_t off; |
207 | } rlimit_ent; |
208 | |
209 | static rlimit_ent rlimits[] = { |
210 | #define R(r, n) { #n, #r, r, offsetof(xlimit, n) }, |
211 | #include "rlimits.h" |
212 | { 0, 0, 0, 0 } |
213 | }; |
214 | |
215 | #define RLIMIT(xl, o) ((struct rlimit *)((char *)(xl) + (o))) |
216 | |
217 | /* --- @rlimit_get@ --- * |
218 | * |
219 | * Arguments: @xlimit *xl@ = pointer to limit structure |
220 | * |
221 | * Returns: --- |
222 | * |
223 | * Use: Initializes a limit structure from the current limits. |
224 | */ |
225 | |
226 | static void rlimit_get(xlimit *xl) |
227 | { |
228 | rlimit_ent *r; |
229 | |
230 | for (r = rlimits; r->name; r++) { |
231 | if (getrlimit(r->r, RLIMIT(xl, r->off))) { |
232 | moan("couldn't read %s: %s", r->rname, strerror(errno)); |
233 | _exit(1); |
234 | } |
235 | } |
236 | } |
237 | |
238 | /* --- @rlimit_set@ --- * |
239 | * |
240 | * Arguments: @xlimit *xl@ = pointer to limit structure |
241 | * |
242 | * Returns: --- |
243 | * |
244 | * Use: Sets resource limits from the supplied limits structure. |
245 | */ |
246 | |
247 | static void rlimit_set(xlimit *xl) |
248 | { |
249 | rlimit_ent *r; |
250 | |
251 | for (r = rlimits; r->name; r++) { |
252 | if (setrlimit(r->r, RLIMIT(xl, r->off))) { |
253 | moan("couldn't set %s: %s", r->rname, strerror(errno)); |
254 | _exit(1); |
255 | } |
256 | } |
257 | } |
258 | |
259 | /* --- @rlimit_option@ --- */ |
260 | |
261 | static int rlimit_option(xlimit *xl, scanner *sc) |
262 | { |
263 | CONF_BEGIN(sc, "rlimit", "resource limit") |
264 | enum { w_soft, w_hard, w_both } which = w_both; |
265 | rlimit_ent *chosen; |
266 | struct rlimit *rl; |
267 | long v; |
268 | |
269 | /* --- Find out which resource is being fiddled --- */ |
270 | |
271 | { |
272 | rlimit_ent *r; |
273 | |
274 | chosen = 0; |
275 | for (r = rlimits; r->name; r++) { |
276 | if (strncmp(sc->d.buf, r->name, sc->d.len) == 0) { |
277 | if (r->name[sc->d.len] == 0) { |
278 | chosen = r; |
279 | break; |
280 | } else if (chosen) |
281 | error(sc, "ambiguous resource limit name `%s'", sc->d.buf); |
282 | else if (CONF_QUAL) |
283 | chosen = r; |
284 | } |
285 | } |
286 | if (!chosen) |
287 | CONF_REJECT; |
288 | token(sc); |
289 | rl = RLIMIT(xl, chosen->off); |
290 | } |
291 | |
292 | /* --- Look for hard or soft restrictions --- */ |
293 | |
294 | { |
295 | int i; |
296 | if (sc->t == '.') |
297 | token(sc); |
298 | if (sc->t == CTOK_WORD) { |
299 | if ((i = conf_enum(sc, "soft,hard", |
300 | ENUM_ABBREV | ENUM_NONE, "limit type")) != -1) |
301 | which = i; |
302 | } |
303 | } |
304 | |
305 | /* --- Now read the new value --- */ |
306 | |
307 | if (sc->t == '=') |
308 | token(sc); |
309 | if (sc->t != CTOK_WORD) |
310 | error(sc, "parse error, expected limit value"); |
311 | |
312 | if (conf_enum(sc, "unlimited,infinity", |
313 | ENUM_ABBREV | ENUM_NONE, "limit value") > -1) |
314 | v = RLIM_INFINITY; |
315 | else { |
316 | char *p; |
317 | |
318 | v = strtol(sc->d.buf, &p, 0); |
319 | if (p == sc->d.buf) |
320 | error(sc, "parse error, invalid limit value `%s'", sc->d.buf); |
321 | switch (tolower((unsigned char)*p)) { |
322 | case 0: break; |
323 | case 'b': v *= 512; break; |
324 | case 'g': v *= 1024; |
325 | case 'm': v *= 1024; |
326 | case 'k': v *= 1024; break; |
327 | default: error(sc, "parse error, invalid limit scale `%c'", *p); |
328 | } |
329 | token(sc); |
330 | } |
331 | |
332 | /* --- Store the limit value away --- */ |
333 | |
334 | switch (which) { |
335 | case w_both: |
336 | rl->rlim_cur = v; |
337 | rl->rlim_max = v; |
338 | break; |
339 | case w_soft: |
340 | if (v > rl->rlim_max) |
341 | error(sc, "soft limit %l exceeds hard limit %l for %s", |
342 | v, rl->rlim_max, chosen->rname); |
343 | rl->rlim_cur = v; |
344 | break; |
345 | case w_hard: |
346 | rl->rlim_max = v; |
347 | if (rl->rlim_cur > v) |
348 | rl->rlim_cur = v; |
349 | break; |
350 | } |
351 | |
352 | CONF_ACCEPT; |
353 | CONF_END; |
354 | } |
355 | |
356 | #endif |
357 | |
358 | /*----- Environment fiddling ----------------------------------------------*/ |
359 | |
360 | /* --- @xenv_option@ --- * |
361 | * |
362 | * Arguments: @xopts *xo@ = pointer to options block |
363 | * @scanner *sc@ = pointer to scanner |
364 | * |
365 | * Returns: Nonzero if claimed |
366 | * |
367 | * Use: Parses environment variable assignments. |
368 | */ |
369 | |
370 | static int xenv_option(xopts *xo, scanner *sc) |
371 | { |
372 | CONF_BEGIN(sc, "env", "environment") |
373 | xenv *xe; |
374 | |
375 | /* --- Unset a variable --- */ |
376 | |
377 | if (strcmp(sc->d.buf, "unset") == 0) { |
378 | token(sc); |
379 | if (sc->t != CTOK_WORD) |
380 | error(sc, "parse error, expected environment variable name"); |
381 | xe = CREATE(xenv); |
382 | xe->name = xstrdup(sc->d.buf); |
383 | xe->value = 0; |
384 | xe->act = XEA_SET; |
385 | token(sc); |
386 | goto link; |
387 | } |
388 | |
389 | /* --- Clear the entire environment --- */ |
390 | |
391 | if (strcmp(sc->d.buf, "clear") == 0) { |
392 | token(sc); |
393 | xe = CREATE(xenv); |
394 | xe->act = XEA_CLEAR; |
395 | goto link; |
396 | } |
397 | |
398 | /* --- Allow `set' to be omitted if there's a prefix --- */ |
399 | |
400 | if (strcmp(sc->d.buf, "set") == 0) |
401 | token(sc); |
402 | else if (!CONF_QUAL) |
403 | CONF_REJECT; |
404 | |
405 | /* --- Set a variable --- */ |
406 | |
407 | if (sc->t != CTOK_WORD) |
408 | error(sc, "parse error, expected environment variable name"); |
409 | xe = CREATE(xenv); |
410 | xe->name = xstrdup(sc->d.buf); |
411 | token(sc); |
412 | if (sc->t == '=') |
413 | token(sc); |
414 | if (sc->t != CTOK_WORD) |
415 | error(sc, "parse error, expected environment variable value"); |
416 | xe->value = xstrdup(sc->d.buf); |
417 | xe->act = XEA_SET; |
418 | token(sc); |
419 | goto link; |
420 | |
421 | link: |
422 | xe->next = 0; |
423 | *xo->etail = xe; |
424 | xo->etail = &xe->next; |
425 | CONF_ACCEPT; |
426 | |
427 | /* --- Nothing else to try --- */ |
428 | |
429 | CONF_END; |
430 | } |
431 | |
432 | /* --- @xenv_apply@ --- * |
433 | * |
434 | * Arguments: @xenv *xe@ = pointer to a variable change list |
435 | * |
436 | * Returns: --- |
437 | * |
438 | * Use: Modifies the environment (in @env@) according to the list. |
439 | */ |
440 | |
441 | static void xenv_apply(xenv *xe) |
442 | { |
443 | while (xe) { |
444 | switch (xe->act) { |
445 | case XEA_SET: |
446 | env_put(&env, xe->name, xe->value); |
447 | break; |
448 | case XEA_CLEAR: |
449 | env_destroy(&env); |
450 | sym_create(&env); |
451 | break; |
452 | } |
453 | xe = xe->next; |
454 | } |
455 | } |
456 | |
457 | /* --- @xenv_destroy@ --- * |
458 | * |
459 | * Arguments: @xenv *xe@ = pointer to a variable change list |
460 | * |
461 | * Returns: --- |
462 | * |
463 | * Use: Frees the memory used by an environment variable change list. |
464 | */ |
465 | |
466 | static void xenv_destroy(xenv *xe) |
467 | { |
468 | while (xe) { |
469 | xenv *xxe = xe; |
470 | xe = xe->next; |
471 | free(xxe->name); |
472 | if (xxe->value) |
473 | free(xxe->value); |
474 | DESTROY(xxe); |
475 | } |
476 | } |
477 | |
478 | /*----- Miscellaneous good things -----------------------------------------*/ |
479 | |
480 | /* --- @x_tidy@ --- * |
481 | * |
482 | * Arguments: @xargs *xa@ = pointer to an arguments block |
483 | * @xopts *xo@ = pointer to an options block |
484 | * |
485 | * Returns: --- |
486 | * |
487 | * Use: Releases a reference to argument and options blocks. |
488 | */ |
489 | |
490 | static void x_tidy(xargs *xa, xopts *xo) |
491 | { |
492 | xa->ref--; |
493 | if (!xa->ref) |
494 | free(xa); |
495 | |
496 | xo->ref--; |
497 | if (!xo->ref) { |
498 | xenv_destroy(xo->env); |
499 | DESTROY(xo); |
500 | } |
501 | } |
502 | |
503 | /*----- Executable endpoints ----------------------------------------------*/ |
504 | |
505 | /* --- @attach@ --- */ |
506 | |
507 | static void xept_error(char */*p*/, void */*v*/); |
508 | |
509 | static void xept_attach(endpt *e, reffd *in, reffd *out) |
510 | { |
511 | xept *xe = (xept *)e; |
512 | pid_t kid; |
513 | int fd[2]; |
514 | |
515 | /* --- Make a pipe for standard error --- */ |
516 | |
517 | if (pipe(fd)) { |
518 | fw_log(-1, "[%s] couldn't create pipe: %s", xe->desc, strerror(errno)); |
519 | return; |
520 | } |
521 | fdflags(fd[0], O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
522 | |
523 | /* --- Fork a child, and handle an error if there was one --- */ |
524 | |
525 | if ((kid = fork()) == -1) { |
526 | fw_log(-1, "[%s] couldn't fork: %s", xe->desc, strerror(errno)); |
527 | close(fd[0]); |
528 | close(fd[1]); |
529 | return; |
530 | } |
531 | |
532 | /* --- Do the child thing --- */ |
533 | |
534 | if (kid == 0) { |
535 | xopts *xo = xe->xo; |
536 | |
537 | /* --- Fiddle with the file descriptors --- * |
538 | * |
539 | * Attach the other endpoint's descriptors to standard input and output. |
540 | * Attach my pipe to standard error. Mark everything as blocking and |
541 | * not-to-be-closed-on-exec at this end. |
542 | */ |
543 | |
544 | close(fd[0]); |
545 | if (dup2(in->fd, STDIN_FILENO) < 0 || |
546 | dup2(out->fd, STDOUT_FILENO) < 0 || |
547 | dup2(fd[1], STDERR_FILENO) < 0) { |
548 | moan("couldn't manipulate file descriptors: %s", strerror(errno)); |
549 | _exit(1); |
550 | } |
551 | |
552 | if (in->fd > 2) |
553 | close(in->fd); |
554 | if (out->fd > 2) |
555 | close(out->fd); |
556 | |
557 | fdflags(STDIN_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0); |
558 | fdflags(STDOUT_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0); |
559 | fdflags(STDERR_FILENO, O_NONBLOCK, 0, FD_CLOEXEC, 0); |
560 | |
561 | /* --- First of all set the @chroot@ prison --- */ |
562 | |
563 | if (xo->root && chroot(xo->root)) { |
564 | moan("couldn't set `%s' as filesystem root: %s", |
565 | xo->root, strerror(errno)); |
566 | _exit(1); |
567 | } |
568 | |
569 | /* --- Now set the current directory --- */ |
570 | |
571 | if (xo->dir ? chdir(xo->dir) : xo->root ? chdir("/") : 0) { |
572 | moan("couldn't set `%s' as current directory: %s", |
573 | xo->dir ? xo->dir : "/", strerror(errno)); |
574 | _exit(1); |
575 | } |
576 | |
577 | /* --- Set the resource limits --- */ |
578 | |
579 | #ifdef HAVE_SETRLIMIT |
580 | rlimit_set(&xo->xl); |
581 | #endif |
582 | |
583 | /* --- Set group id --- */ |
584 | |
585 | if (xo->gid != -1) { |
586 | if (setgid(xo->gid)) { |
587 | moan("couldn't set gid %i: %s", xo->gid, strerror(errno)); |
588 | _exit(1); |
589 | } |
590 | #ifdef HAVE_SETGROUPS |
591 | if (setgroups(1, &xo->gid)) |
592 | moan("warning: couldn't set group list to %i: %s", xo->gid, |
593 | strerror(errno)); |
594 | #endif |
595 | } |
596 | |
597 | /* --- Set uid --- */ |
598 | |
599 | if (xo->uid != -1) { |
600 | if (setuid(xo->uid)) { |
601 | moan("couldn't set uid %i: %s", xo->uid, strerror(errno)); |
602 | _exit(1); |
603 | } |
604 | } |
605 | |
606 | /* --- Play with signal dispositions --- */ |
607 | |
608 | signal(SIGPIPE, SIG_DFL); |
609 | |
610 | /* --- Fiddle with the environment --- */ |
611 | |
612 | xenv_apply(exec_opts.env); |
613 | xenv_apply(xe->xo->env); |
614 | environ = env_export(&env); |
615 | |
616 | /* --- Run the program --- */ |
617 | |
618 | execvp(xe->xa->file, xe->xa->argv); |
619 | moan("couldn't execute `%s': %s", xe->xa->file, strerror(errno)); |
620 | _exit(127); |
621 | } |
622 | |
623 | /* --- The child's done; see to the parent --- */ |
624 | |
625 | xe->kid = kid; |
626 | selbuf_init(&xe->err, sel, fd[0], xept_error, xe); |
627 | close(fd[1]); |
628 | xe->next = xept_list; |
629 | xe->prev = 0; |
630 | if (xept_list) |
631 | xept_list->prev = xe; |
632 | xept_list = xe; |
633 | if (!(xe->xo->f & XF_NOLOG)) |
634 | fw_log(-1, "[%s] started with pid %i", xe->desc, kid); |
635 | fw_inc(); |
636 | return; |
637 | } |
638 | |
28d2517c |
639 | /* --- @xept_file@ --- */ |
640 | |
641 | static void xept_file(endpt *e, endpt *f) |
642 | { |
643 | xept *xe = (xept *)e; |
644 | xe->f = f; |
645 | } |
646 | |
48bb1f76 |
647 | /* --- @xept_close@ --- */ |
648 | |
649 | static void xept_close(endpt *e) |
650 | { |
651 | xept *xe = (xept *)e; |
652 | if (xe->kid == -1) { |
28d2517c |
653 | if (xe->f) |
654 | xe->f->ops->close(xe->f); |
48bb1f76 |
655 | x_tidy(xe->xa, xe->xo); |
656 | DESTROY(xe); |
657 | fw_dec(); |
658 | } |
659 | } |
660 | |
661 | /* --- @xept_destroy@ --- */ |
662 | |
663 | static void xept_destroy(xept *xe) |
664 | { |
665 | /* --- First emit the news about the process --- */ |
666 | |
667 | if (xe->xo->f & XF_NOLOG) |
668 | /* Nothin' doin' */; |
669 | else if (WIFEXITED(xe->st)) { |
670 | if (WEXITSTATUS(xe->st) == 0) |
671 | fw_log(-1, "[%s] pid %i exited successfully", xe->desc, xe->kid); |
672 | else { |
673 | fw_log(-1, "[%s] pid %i failed: status %i", |
674 | xe->desc, xe->kid, WEXITSTATUS(xe->st)); |
675 | } |
676 | } else if (WIFSIGNALED(xe->st)) { |
677 | const char *s; |
678 | #ifdef HAVE_STRSIGNAL |
679 | s = strsignal(WTERMSIG(xe->st)); |
680 | #elif HAVE__SYS_SIGLIST |
681 | s = _sys_siglist[WTERMSIG(xe->st)]; |
682 | #else |
683 | char buf[32]; |
684 | sprintf(buf, "signal %i", WTERMSIG(xe->st)); |
685 | s = buf; |
686 | #endif |
687 | fw_log(-1, "[%s] pid %i failed: %s", xe->desc, xe->kid, s); |
688 | } else |
689 | fw_log(-1, "[%s] pid %i failed: unrecognized status", xe->desc, xe->kid); |
690 | |
691 | /* --- Free up the parent-side resources --- */ |
692 | |
693 | if (xe->next) |
694 | xe->next->prev = xe->prev; |
695 | if (xe->prev) |
696 | xe->prev->next = xe->next; |
697 | else |
698 | xept_list = xe->next; |
699 | |
28d2517c |
700 | if (xe->f) |
701 | xe->f->ops->close(xe->f); |
48bb1f76 |
702 | x_tidy(xe->xa, xe->xo); |
703 | fw_dec(); |
704 | DESTROY(xe); |
705 | } |
706 | |
707 | /* --- @xept_chld@ --- * |
708 | * |
709 | * Arguments: @int n@ = signal number |
710 | * @void *p@ = uninteresting pointer |
711 | * |
712 | * Returns: --- |
713 | * |
714 | * Use: Deals with child death situations. |
715 | */ |
716 | |
717 | static void xept_chld(int n, void *p) |
718 | { |
719 | pid_t kid; |
720 | int st; |
721 | |
722 | while ((kid = waitpid(-1, &st, WNOHANG)) > 0) { |
723 | xept *xe = xept_list; |
724 | while (xe) { |
725 | xept *xxe = xe; |
726 | xe = xe->next; |
727 | if (kid == xxe->kid) { |
728 | xxe->st = st; |
729 | xxe->e.f |= XEF_EXIT; |
730 | if (xxe->e.f & XEF_CLOSE) |
731 | xept_destroy(xxe); |
732 | break; |
733 | } |
734 | } |
735 | } |
736 | } |
737 | |
738 | /* --- @xept_error@ --- * |
739 | * |
740 | * Arguments: @char *p@ = pointer to string read from stderr |
741 | * @void *v@ = pointer to by endpoint |
742 | * |
743 | * Returns: --- |
744 | * |
745 | * Use: Handles error reports from a child process. |
746 | */ |
747 | |
748 | static void xept_error(char *p, void *v) |
749 | { |
750 | xept *xe = v; |
751 | if (p) |
752 | fw_log(-1, "[%s] pid %i: %s", xe->desc, xe->kid, p); |
753 | else { |
48bb1f76 |
754 | close(xe->err.reader.fd); |
e68b88bf |
755 | selbuf_destroy(&xe->err); |
48bb1f76 |
756 | xe->e.f |= XEF_CLOSE; |
757 | if (xe->e.f & XEF_EXIT) |
758 | xept_destroy(xe); |
759 | } |
760 | } |
761 | |
762 | /* --- Endpoint operations --- */ |
763 | |
28d2517c |
764 | static endpt_ops xept_ops = { xept_attach, xept_file, 0, xept_close }; |
48bb1f76 |
765 | |
766 | /*----- General operations on sources and targets -------------------------*/ |
767 | |
768 | /* --- @exec_init@ --- * |
769 | * |
770 | * Arguments: --- |
771 | * |
772 | * Returns: --- |
773 | * |
774 | * Use: Initializes the executable problem source and target. |
775 | */ |
776 | |
777 | void exec_init(void) |
778 | { |
779 | rlimit_get(&exec_opts.xl); |
780 | sig_add(&xept_sig, SIGCHLD, xept_chld, 0); |
781 | sym_create(&env); |
782 | env_import(&env, environ); |
783 | } |
784 | |
785 | /* --- @exec_option@ --- */ |
786 | |
787 | static int exec_option(xdata *x, scanner *sc) |
788 | { |
789 | xopts *xo = x ? x->xo : &exec_opts; |
790 | |
791 | CONF_BEGIN(sc, "exec", "executable"); |
792 | |
793 | /* --- Logging settings --- */ |
794 | |
795 | if (strcmp(sc->d.buf, "logging") == 0 || |
796 | strcmp(sc->d.buf, "log") == 0) { |
797 | token(sc); |
798 | if (sc->t == '=') |
799 | token(sc); |
800 | if (conf_enum(sc, "no,yes", ENUM_ABBREV, "logging status")) |
801 | xo->f &= ~XF_NOLOG; |
802 | else |
803 | xo->f |= XF_NOLOG; |
804 | CONF_ACCEPT; |
805 | } |
806 | |
807 | /* --- Current directory setting --- * |
808 | * |
809 | * Lots of possibilities to guard against possible brainoes. |
810 | */ |
811 | |
812 | if (strcmp(sc->d.buf, "dir") == 0 || |
813 | strcmp(sc->d.buf, "cd") == 0 || |
814 | strcmp(sc->d.buf, "chdir") == 0 || |
815 | strcmp(sc->d.buf, "cwd") == 0) { |
816 | dstr d = DSTR_INIT; |
817 | token(sc); |
818 | if (sc->t == '=') |
819 | token(sc); |
820 | conf_name(sc, '/', &d); |
821 | xo->dir = xstrdup(d.buf); |
822 | dstr_destroy(&d); |
823 | CONF_ACCEPT; |
824 | } |
825 | |
826 | /* --- Set a chroot prison --- */ |
827 | |
828 | if (strcmp(sc->d.buf, "root") == 0 || |
829 | strcmp(sc->d.buf, "chroot") == 0) { |
830 | dstr d = DSTR_INIT; |
831 | token(sc); |
832 | if (sc->t == '=') |
833 | token(sc); |
834 | conf_name(sc, '/', &d); |
835 | xo->root = xstrdup(d.buf); |
836 | dstr_destroy(&d); |
837 | CONF_ACCEPT; |
838 | } |
839 | |
840 | /* --- Set the target user id --- */ |
841 | |
842 | if (strcmp(sc->d.buf, "uid") == 0 || |
843 | strcmp(sc->d.buf, "user") == 0) { |
844 | token(sc); |
845 | if (sc->t == '=') |
846 | token(sc); |
847 | if (sc->t != CTOK_WORD) |
848 | error(sc, "parse error, expected user name or uid"); |
849 | if (isdigit((unsigned char)*sc->d.buf)) |
850 | xo->uid = atoi(sc->d.buf); |
851 | else { |
852 | struct passwd *pw = getpwnam(sc->d.buf); |
853 | if (!pw) |
854 | error(sc, "unknown user name `%s'", sc->d.buf); |
855 | xo->uid = pw->pw_uid; |
856 | } |
857 | token(sc); |
858 | CONF_ACCEPT; |
859 | } |
860 | |
861 | /* --- Set the target group id --- */ |
862 | |
863 | if (strcmp(sc->d.buf, "gid") == 0 || |
864 | strcmp(sc->d.buf, "group") == 0) { |
865 | token(sc); |
866 | if (sc->t == '=') |
867 | token(sc); |
868 | if (sc->t != CTOK_WORD) |
869 | error(sc, "parse error, expected group name or gid"); |
870 | if (isdigit((unsigned char)*sc->d.buf)) |
871 | xo->gid = atoi(sc->d.buf); |
872 | else { |
873 | struct group *gr = getgrnam(sc->d.buf); |
874 | if (!gr) |
875 | error(sc, "unknown user name `%s'", sc->d.buf); |
876 | xo->gid = gr->gr_gid; |
877 | } |
878 | token(sc); |
879 | CONF_ACCEPT; |
880 | } |
881 | |
882 | /* --- Now try resource limit settings --- */ |
883 | |
884 | if (rlimit_option(&xo->xl, sc)) |
885 | CONF_ACCEPT; |
886 | |
887 | /* --- And then environment settings --- */ |
888 | |
889 | if (xenv_option(xo, sc)) |
890 | CONF_ACCEPT; |
891 | |
892 | /* --- Nothing found --- */ |
893 | |
894 | CONF_END; |
895 | } |
896 | |
897 | /* --- @exec_desc@ --- */ |
898 | |
899 | static void exec_desc(xdata *x, dstr *d) |
900 | { |
901 | char **p; |
902 | char sep = '['; |
903 | dstr_puts(d, "exec "); |
904 | if (strcmp(x->xa->file, x->xa->argv[0]) != 0) { |
905 | dstr_puts(d, x->xa->file); |
906 | dstr_putc(d, ' '); |
907 | } |
908 | for (p = x->xa->argv; *p; p++) { |
909 | dstr_putc(d, sep); |
910 | dstr_puts(d, *p); |
911 | sep = ' '; |
912 | } |
913 | dstr_putc(d, ']'); |
914 | dstr_putz(d); |
915 | } |
916 | |
917 | /* --- @exec_read@ --- */ |
918 | |
919 | static void exec_read(xdata *x, scanner *sc) |
920 | { |
921 | size_t base = 0; |
922 | dstr d = DSTR_INIT; |
923 | xargs *xa; |
924 | |
925 | /* --- Read the first word --- * |
926 | * |
927 | * This is either a shell command or the actual program to run. |
928 | */ |
929 | |
930 | if (sc->t == CTOK_WORD) { |
931 | dstr_putd(&d, &sc->d); d.len++; |
932 | base = d.len; |
933 | token(sc); |
934 | } |
935 | |
936 | /* --- See if there's a list of arguments --- * |
937 | * |
938 | * If not, then the thing I saw was a shell command, so build the proper |
939 | * arguments for that. |
940 | */ |
941 | |
942 | if (sc->t != '[') { |
943 | char *p; |
944 | if (!base) |
945 | error(sc, "parse error, expected shell command or argument list"); |
946 | xa = xmalloc(XARGS_SZ(3) + 8 + 3 + d.len); |
947 | p = (char *)(xa->argv + 4); |
948 | xa->ref = 1; |
949 | xa->file = p; |
950 | xa->argv[0] = p; memcpy(p, "/bin/sh", 8); p += 8; |
951 | xa->argv[1] = p; memcpy(p, "-c", 3); p += 3; |
952 | xa->argv[2] = p; memcpy(p, d.buf, d.len); p += d.len; |
953 | xa->argv[3] = 0; |
954 | } |
955 | |
956 | /* --- Snarf in a list of arguments --- */ |
957 | |
958 | else { |
959 | int argc = 0; |
960 | char *p, *q; |
961 | char **v; |
962 | |
963 | /* --- Strip off the leading `[' --- */ |
964 | |
965 | token(sc); |
966 | |
967 | /* --- Read a sequence of arguments --- */ |
968 | |
969 | while (sc->t == CTOK_WORD) { |
970 | dstr_putd(&d, &sc->d); d.len++; |
971 | token(sc); |
972 | argc++; |
973 | } |
974 | |
975 | /* --- Expect the closing `]' --- */ |
976 | |
977 | if (sc->t != ']') |
978 | error(sc, "parse error, missing `]'"); |
979 | token(sc); |
980 | |
981 | /* --- If there are no arguments, whinge --- */ |
982 | |
983 | if (!argc) |
984 | error(sc, "must specify at least one argument"); |
985 | |
986 | /* --- Allocate a lump of memory for the array --- */ |
987 | |
988 | xa = xmalloc(XARGS_SZ(argc) + d.len); |
989 | xa->ref = 1; |
990 | v = xa->argv; |
991 | p = (char *)(v + argc + 1); |
992 | memcpy(p, d.buf, d.len); |
993 | q = p + d.len; |
994 | xa->file = p; |
995 | p += base; |
996 | |
997 | /* --- Start dumping addresses into the @argv@ array --- */ |
998 | |
999 | for (;;) { |
1000 | *v++ = p; |
1001 | while (*p++ && p < q) |
1002 | ; |
1003 | if (p >= q) |
1004 | break; |
1005 | } |
1006 | *v++ = 0; |
1007 | } |
1008 | |
1009 | /* --- Do some other setting up --- */ |
1010 | |
1011 | dstr_destroy(&d); |
1012 | x->xa = xa; |
1013 | x->xo = CREATE(xopts); |
1014 | *x->xo = exec_opts; |
1015 | x->xo->ref = 1; |
1016 | return; |
1017 | } |
1018 | |
1019 | /* --- @exec_endpt@ --- */ |
1020 | |
1021 | static endpt *exec_endpt(xdata *x, const char *desc) |
1022 | { |
1023 | xept *xe = CREATE(xept); |
1024 | xe->e.ops = &xept_ops; |
1025 | xe->e.other = 0; |
1026 | xe->e.t = 0; |
1027 | xe->e.f = 0; |
1028 | xe->xa = x->xa; xe->xa->ref++; |
1029 | xe->xo = x->xo; xe->xo->ref++; |
1030 | xe->kid = -1; |
28d2517c |
1031 | xe->f = 0; |
48bb1f76 |
1032 | xe->desc = desc; |
1033 | return (&xe->e); |
1034 | } |
1035 | |
1036 | /* --- @exec_destroy@ --- */ |
1037 | |
1038 | static void exec_destroy(xdata *x) |
1039 | { |
1040 | x_tidy(x->xa, x->xo); |
1041 | } |
1042 | |
1043 | /*----- Source definition -------------------------------------------------*/ |
1044 | |
1045 | /* --- @option@ --- */ |
1046 | |
1047 | static int xsource_option(source *s, scanner *sc) |
1048 | { |
1049 | xsource *xs = (xsource *)s; |
1050 | return (exec_option(xs ? &xs->x : 0, sc)); |
1051 | } |
1052 | |
1053 | /* --- @read@ --- */ |
1054 | |
1055 | static source *xsource_read(scanner *sc) |
1056 | { |
1057 | xsource *xs; |
1058 | |
1059 | if (!conf_prefix(sc, "exec")) |
1060 | return (0); |
1061 | xs = CREATE(xsource); |
1062 | xs->s.ops = &xsource_ops; |
1063 | xs->s.desc = 0; |
1064 | exec_read(&xs->x, sc); |
1065 | return (&xs->s); |
1066 | } |
1067 | |
1068 | /* --- @attach@ --- */ |
1069 | |
1070 | static void xsource_destroy(source */*s*/); |
1071 | |
1072 | static void xsource_attach(source *s, scanner *sc, target *t) |
1073 | { |
1074 | xsource *xs = (xsource *)s; |
1075 | endpt *e, *ee; |
1076 | |
1077 | /* --- Set up the source description string --- */ |
1078 | |
1079 | { |
1080 | dstr d = DSTR_INIT; |
1081 | exec_desc(&xs->x, &d); |
1082 | dstr_puts(&d, " -> "); |
1083 | dstr_puts(&d, t->desc); |
1084 | xs->s.desc = xstrdup(d.buf); |
1085 | dstr_destroy(&d); |
1086 | } |
1087 | |
1088 | /* --- Create the endpoints --- */ |
1089 | |
1090 | if ((ee = t->ops->create(t, xs->s.desc)) == 0) |
1091 | goto tidy; |
1092 | if ((e = exec_endpt(&xs->x, xs->s.desc)) == 0) { |
1093 | ee->ops->close(ee); |
1094 | goto tidy; |
1095 | } |
1096 | endpt_join(e, ee); |
1097 | |
1098 | /* --- Dispose of source and target --- */ |
1099 | |
1100 | tidy: |
1101 | t->ops->destroy(t); |
1102 | xsource_destroy(&xs->s); |
1103 | } |
1104 | |
1105 | /* --- @destroy@ --- */ |
1106 | |
1107 | static void xsource_destroy(source *s) |
1108 | { |
1109 | xsource *xs = (xsource *)s; |
1110 | exec_destroy(&xs->x); |
1111 | DESTROY(xs); |
1112 | } |
1113 | |
1114 | /* --- Executable source operations --- */ |
1115 | |
1116 | source_ops xsource_ops = { |
1117 | "exec", |
1118 | xsource_option, xsource_read, xsource_attach, xsource_destroy |
1119 | }; |
1120 | |
1121 | /*----- Exec target description -------------------------------------------*/ |
1122 | |
1123 | /* --- @option@ --- */ |
1124 | |
1125 | static int xtarget_option(target *t, scanner *sc) |
1126 | { |
1127 | xtarget *xt = (xtarget *)t; |
1128 | return (exec_option(xt ? &xt->x : 0, sc)); |
1129 | } |
1130 | |
1131 | /* --- @read@ --- */ |
1132 | |
1133 | static target *xtarget_read(scanner *sc) |
1134 | { |
1135 | xtarget *xt; |
1136 | dstr d = DSTR_INIT; |
1137 | |
1138 | if (!conf_prefix(sc, "exec")) |
1139 | return (0); |
1140 | xt = CREATE(xtarget); |
1141 | xt->t.ops = &xtarget_ops; |
1142 | exec_read(&xt->x, sc); |
1143 | exec_desc(&xt->x, &d); |
1144 | xt->t.desc = xstrdup(d.buf); |
1145 | dstr_destroy(&d); |
1146 | return (&xt->t); |
1147 | } |
1148 | |
1149 | /* --- @create@ --- */ |
1150 | |
1151 | static endpt *xtarget_create(target *t, const char *desc) |
1152 | { |
1153 | xtarget *xt = (xtarget *)t; |
1154 | endpt *e = exec_endpt(&xt->x, desc); |
1155 | return (e); |
1156 | } |
1157 | |
1158 | /* --- @destroy@ --- */ |
1159 | |
1160 | static void xtarget_destroy(target *t) |
1161 | { |
1162 | xtarget *xt = (xtarget *)t; |
1163 | exec_destroy(&xt->x); |
1164 | DESTROY(xt); |
1165 | } |
1166 | |
1167 | /* --- Exec target operations --- */ |
1168 | |
1169 | target_ops xtarget_ops = { |
1170 | "exec", |
1171 | xtarget_option, xtarget_read, xtarget_create, xtarget_destroy |
1172 | }; |
1173 | |
1174 | /*----- That's all, folks -------------------------------------------------*/ |