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