1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26 /*
27 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
28 */
29
30 #include <assert.h>
31 #include <dlfcn.h>
32 #include <errno.h>
33 #include <libzonecfg.h>
34 #include <link.h>
35 #include <string.h>
36 #include <strings.h>
37 #include <sys/list.h>
38 #include <sys/types.h>
39 #include <sys/mkdev.h>
40 #include <sys/mman.h>
41 #include <sys/mnttab.h>
42
43 #include "Pcontrol.h"
44
45 struct path_node {
46 struct path_node *pn_next;
47 char *pn_path;
48 };
49 typedef struct path_node path_node_t;
50
51 /*
52 * Parameters of the lofs lookup cache.
53 */
54 static struct stat64 lofs_mstat; /* last stat() of MNTTAB */
55 static struct lofs_mnttab { /* linked list of all lofs mount points */
56 struct lofs_mnttab *l_next;
57 char *l_special; /* extracted from MNTTAB */
58 char *l_mountp; /* ditto */
59 } *lofs_mnttab = NULL;
60 static mutex_t lofs_lock = DEFAULTMUTEX; /* protects the lofs cache */
61
62 static void
63 rebuild_lofs_cache(void)
64 {
65 struct mnttab mt;
66 struct mnttab mt_find;
67 struct lofs_mnttab *lmt;
68 struct lofs_mnttab *next;
69 FILE *fp;
70
71 assert(MUTEX_HELD(&lofs_lock));
72
73 /* destroy the old cache */
74 for (lmt = lofs_mnttab; lmt != NULL; lmt = next) {
75 next = lmt->l_next;
76 free(lmt->l_special);
77 free(lmt->l_mountp);
78 free(lmt);
79 }
80 lofs_mnttab = NULL;
81
82 /* prepare to create the new cache */
83 if ((fp = fopen(MNTTAB, "r")) == NULL)
84 return;
85
86 /*
87 * We only care about lofs mount points. But we need to
88 * ignore lofs mounts where the source path is the same
89 * as the target path. (This can happen when a non-global
90 * zone has a lofs mount of a global zone filesystem, since
91 * the source path can't expose information about global
92 * zone paths to the non-global zone.)
93 */
94 bzero(&mt_find, sizeof (mt_find));
95 mt_find.mnt_fstype = "lofs";
96 while (getmntany(fp, &mt, &mt_find) == 0 &&
97 (strcmp(mt.mnt_fstype, "lofs") == 0) &&
98 (strcmp(mt.mnt_special, mt.mnt_mountp) != 0)) {
99 if ((lmt = malloc(sizeof (struct lofs_mnttab))) == NULL)
100 break;
101 lmt->l_special = strdup(mt.mnt_special);
102 lmt->l_mountp = strdup(mt.mnt_mountp);
103 lmt->l_next = lofs_mnttab;
104 lofs_mnttab = lmt;
105 }
106
107 (void) fclose(fp);
108 }
109
110 static const char *
111 lookup_lofs_mount_point(const char *mountp)
112 {
113 struct lofs_mnttab *lmt;
114
115 assert(MUTEX_HELD(&lofs_lock));
116
117 for (lmt = lofs_mnttab; lmt != NULL; lmt = lmt->l_next) {
118 if (strcmp(lmt->l_mountp, mountp) == 0)
119 return (lmt->l_special);
120 }
121 return (NULL);
122 }
123
124 static path_node_t *
125 pn_push(path_node_t **pnp, char *path)
126 {
127 path_node_t *pn;
128
129 if ((pn = calloc(sizeof (path_node_t), 1)) == NULL)
130 return (NULL);
131
132 if ((pn->pn_path = strdup(path)) == NULL) {
133 free(pn);
134 return (NULL);
135 }
136 pn->pn_next = *pnp;
137 return (*pnp = pn);
138 }
139
140 static void
141 pn_free(path_node_t **pnp)
142 {
143 path_node_t *pn;
144
145 while (*pnp != NULL) {
146 pn = *pnp;
147 *pnp = pn->pn_next;
148 free(pn->pn_path);
149 free(pn);
150 }
151 }
152
153 static void
154 pn_free2(path_node_t **pn1, path_node_t **pn2)
155 {
156 pn_free(pn1);
157 pn_free(pn2);
158 }
159
160 static char *
161 pn_pop(path_node_t **pnp, char *path)
162 {
163 path_node_t *pn;
164
165 if (*pnp == NULL)
166 return (NULL);
167
168 pn = *pnp;
169 *pnp = pn->pn_next;
170 pn->pn_next = NULL;
171
172 if (path == NULL) {
173 pn_free(&pn);
174 return (NULL);
175 }
176 (void) strlcpy(path, pn->pn_path, PATH_MAX);
177 pn_free(&pn);
178 return (path);
179 }
180
181
182 /*
183 * Libzonecfg.so links against libproc, so libproc can't link against
184 * libzonecfg.so. Also, libzonecfg.so is optional and might not be
185 * installed. Hence instead of relying on linking to access libzonecfg.so,
186 * we'll try dlopening it here. This trick is borrowed from
187 * libc`zone_get_id(), see that function for more detailed comments.
188 */
189 static int
190 i_zone_get_zonepath(char *zone_name, char *zonepath, size_t rp_sz)
191 {
192 typedef int (*zone_get_zonepath_t)(char *, char *, size_t);
193 static zone_get_zonepath_t zone_get_zonepath_fp = NULL;
194
195 if (zone_get_zonepath_fp == NULL) {
196 /* There's no harm in doing this multiple times. */
197 void *dlhandle = dlopen("libzonecfg.so.1", RTLD_LAZY);
198 void *sym = (void *)(-1);
199 if (dlhandle != NULL &&
200 (sym = dlsym(dlhandle, "zone_get_zonepath")) == NULL) {
201 sym = (void *)(-1);
202 (void) dlclose(dlhandle);
203 }
204 zone_get_zonepath_fp = (zone_get_zonepath_t)sym;
205 }
206
207 /* If we've successfully loaded it, call the real function */
208 if (zone_get_zonepath_fp != (zone_get_zonepath_t)(-1))
209 return (zone_get_zonepath_fp(zone_name, zonepath, rp_sz));
210 return (Z_NO_ZONE);
211 }
212
213 char *
214 Pbrandname(struct ps_prochandle *P, char *buf, size_t buflen)
215 {
216 long addr;
217
218 if ((addr = Pgetauxval(P, AT_SUN_BRANDNAME)) == -1)
219 return (NULL);
220
221 if (Pread_string(P, buf, buflen, addr) == -1)
222 return (NULL);
223
224 return (buf);
225 }
226
227 /*
228 * Get the zone name from the core file if we have it; look up the
229 * name based on the zone id if this is a live process.
230 */
231 char *
232 Pzonename(struct ps_prochandle *P, char *s, size_t n)
233 {
234 if (P->state == PS_IDLE) {
235 errno = ENODATA;
236 return (NULL);
237 }
238
239 if (P->state == PS_DEAD) {
240 if (P->core->core_zonename == NULL) {
241 errno = ENODATA;
242 return (NULL);
243 }
244 (void) strlcpy(s, P->core->core_zonename, n);
245 } else {
246 if (getzonenamebyid(P->status.pr_zoneid, s, n) < 0)
247 return (NULL);
248 s[n - 1] = '\0';
249 }
250 return (s);
251 }
252
253 char *
254 Pzoneroot(struct ps_prochandle *P, char *s, size_t n)
255 {
256 char zname[ZONENAME_MAX], zpath[PATH_MAX], tmp[PATH_MAX];
257 int rv;
258
259 if (P->zoneroot != NULL) {
260 (void) strlcpy(s, P->zoneroot, n);
261 return (s);
262 }
263
264 if ((Pzonename(P, zname, sizeof (zname)) == NULL) ||
265 (strcmp(zname, GLOBAL_ZONENAME) == 0)) {
266 if ((P->zoneroot = strdup("")) == NULL) {
267 errno = ENOMEM;
268 return (NULL);
269 }
270 dprintf("Pzoneroot defaulting to '%s'\n", GLOBAL_ZONENAME);
271 (void) strlcpy(s, P->zoneroot, n);
272 return (s);
273 }
274
275 if (i_zone_get_zonepath(zname, zpath, sizeof (zpath)) != Z_OK) {
276 if ((P->zoneroot = strdup("")) == NULL) {
277 errno = ENOMEM;
278 return (NULL);
279 }
280 dprintf(
281 "Pzoneroot zone not found '%s', defaulting to '%s'\n",
282 zname, GLOBAL_ZONENAME);
283 (void) strlcpy(s, P->zoneroot, n);
284 return (s);
285 }
286 (void) strlcat(zpath, "/root", sizeof (zpath));
287
288 if ((rv = resolvepath(zpath, tmp, sizeof (tmp) - 1)) < 0) {
289 if ((P->zoneroot = strdup("")) == NULL) {
290 errno = ENOMEM;
291 return (NULL);
292 }
293 dprintf(
294 "Pzoneroot can't access '%s:%s', defaulting to '%s'\n",
295 zname, zpath, GLOBAL_ZONENAME);
296 (void) strlcpy(s, P->zoneroot, n);
297 return (s);
298 }
299 tmp[rv] = '\0';
300 (void) strlcpy(zpath, tmp, sizeof (zpath));
301
302 if ((P->zoneroot = strdup(zpath)) == NULL) {
303 errno = ENOMEM;
304 return (NULL);
305 }
306 dprintf("Pzoneroot found zone root '%s:%s'\n", zname, zpath);
307 (void) strlcpy(s, P->zoneroot, n);
308 return (s);
309 }
310
311 /*
312 * Plofspath() takes a path, "path", and removes any lofs components from
313 * that path. The resultant path (if different from the starting path)
314 * is placed in "s", which is limited to "n" characters, and the return
315 * value is the pointer s. If there are no lofs components in the path
316 * the NULL is returned and s is not modified. It's ok for "path" and
317 * "s" to be the same pointer. (ie, the results can be stored directly
318 * in the input buffer.) The path that is passed in must be an absolute
319 * path.
320 *
321 * Example:
322 * if "path" == "/foo/bar", and "/candy/" is lofs mounted on "/foo/"
323 * then "/candy/bar/" will be written into "s" and "s" will be returned.
324 */
325 char *
326 Plofspath(const char *path, char *s, size_t n)
327 {
328 char tmp[PATH_MAX + 1];
329 struct stat64 statb;
330 const char *special;
331 char *p, *p2;
332 int rv;
333
334 dprintf("Plofspath path '%s'\n", path);
335
336 /* We only deal with absolute paths */
337 if (path[0] != '/')
338 return (NULL);
339
340 /* Make a copy of the path so that we can muck with it */
341 (void) strlcpy(tmp, path, sizeof (tmp) - 1);
342
343 /*
344 * Use resolvepath() to make sure there are no consecutive or
345 * trailing '/'s in the path.
346 */
347 if ((rv = resolvepath(tmp, tmp, sizeof (tmp) - 1)) >= 0)
348 tmp[rv] = '\0';
349
350 (void) mutex_lock(&lofs_lock);
351
352 /*
353 * If /etc/mnttab has been modified since the last time
354 * we looked, then rebuild the lofs lookup cache.
355 */
356 if (stat64(MNTTAB, &statb) == 0 &&
357 (statb.st_mtim.tv_sec != lofs_mstat.st_mtim.tv_sec ||
358 statb.st_mtim.tv_nsec != lofs_mstat.st_mtim.tv_nsec ||
359 statb.st_ctim.tv_sec != lofs_mstat.st_ctim.tv_sec ||
360 statb.st_ctim.tv_nsec != lofs_mstat.st_ctim.tv_nsec)) {
361 lofs_mstat = statb;
362 rebuild_lofs_cache();
363 }
364
365 /*
366 * So now we're going to search the path for any components that
367 * might be lofs mounts. We'll start out search from the full
368 * path and then step back through each parent directly till
369 * we reach the root. If we find a lofs mount point in the path
370 * then we'll replace the initial portion of the path (up
371 * to that mount point) with the source of that mount point
372 * and then start our search over again.
373 *
374 * Here's some of the variables we're going to use:
375 *
376 * tmp - A pointer to our working copy of the path. Sometimes
377 * this path will be divided into two strings by a
378 * '\0' (NUL) character. The first string is the
379 * component we're currently checking and the second
380 * string is the path components we've already checked.
381 *
382 * p - A pointer to the last '/' seen in the string.
383 *
384 * p[1] - A pointer to the component of the string we've already
385 * checked.
386 *
387 * Initially, p will point to the end of our path and p[1] will point
388 * to an extra '\0' (NUL) that we'll append to the end of the string.
389 * (This is why we declared tmp with a size of PATH_MAX + 1).
390 */
391 p = &tmp[strlen(tmp)];
392 p[1] = '\0';
393 for (;;) {
394 if ((special = lookup_lofs_mount_point(tmp)) != NULL) {
395 char tmp2[PATH_MAX + 1];
396
397 /*
398 * We found a lofs mount. Update the path that we're
399 * checking and start over. This means append the
400 * portion of the path we've already checked to the
401 * source of the lofs mount and re-start this entire
402 * lofs resolution loop. Use resolvepath() to make
403 * sure there are no consecutive or trailing '/'s
404 * in the path.
405 */
406 (void) strlcpy(tmp2, special, sizeof (tmp2) - 1);
407 (void) strlcat(tmp2, "/", sizeof (tmp2) - 1);
408 (void) strlcat(tmp2, &p[1], sizeof (tmp2) - 1);
409 (void) strlcpy(tmp, tmp2, sizeof (tmp) - 1);
410 if ((rv = resolvepath(tmp, tmp, sizeof (tmp) - 1)) >= 0)
411 tmp[rv] = '\0';
412 p = &tmp[strlen(tmp)];
413 p[1] = '\0';
414 continue;
415 }
416
417 /* No lofs mount found */
418 if ((p2 = strrchr(tmp, '/')) == NULL) {
419 char tmp2[PATH_MAX];
420
421 (void) mutex_unlock(&lofs_lock);
422
423 /*
424 * We know that tmp was an absolute path, so if we
425 * made it here we know that (p == tmp) and that
426 * (*p == '\0'). This means that we've managed
427 * to check the whole path and so we're done.
428 */
429 assert(p == tmp);
430 assert(p[0] == '\0');
431
432 /* Restore the leading '/' in the path */
433 p[0] = '/';
434
435 if (strcmp(tmp, path) == 0) {
436 /* The path didn't change */
437 return (NULL);
438 }
439
440 /*
441 * It's possible that lofs source path we just
442 * obtained contains a symbolic link. Use
443 * resolvepath() to clean it up.
444 */
445 (void) strlcpy(tmp2, tmp, sizeof (tmp2));
446 if ((rv = resolvepath(tmp, tmp, sizeof (tmp) - 1)) >= 0)
447 tmp[rv] = '\0';
448
449 /*
450 * It's always possible that our lofs source path is
451 * actually another lofs mount. So call ourselves
452 * recursively to resolve that path.
453 */
454 (void) Plofspath(tmp, tmp, PATH_MAX);
455
456 /* Copy out our final resolved lofs source path */
457 (void) strlcpy(s, tmp, n);
458 dprintf("Plofspath path result '%s'\n", s);
459 return (s);
460 }
461
462 /*
463 * So the path we just checked is not a lofs mount. Next we
464 * want to check the parent path component for a lofs mount.
465 *
466 * First, restore any '/' that we replaced with a '\0' (NUL).
467 * We can determine if we should do this by looking at p[1].
468 * If p[1] points to a '\0' (NUL) then we know that p points
469 * to the end of the string and there is no '/' to restore.
470 * if p[1] doesn't point to a '\0' (NUL) then it points to
471 * the part of the path that we've already verified so there
472 * is a '/' to restore.
473 */
474 if (p[1] != '\0')
475 p[0] = '/';
476
477 /*
478 * Second, replace the last '/' in the part of the path
479 * that we've already checked with a '\0' (NUL) so that
480 * when we loop around we check the parent component of the
481 * path.
482 */
483 p2[0] = '\0';
484 p = p2;
485 }
486 /*NOTREACHED*/
487 }
488
489 /*
490 * Pzonepath() - Way too much code to attempt to derive the full path of
491 * an object within a zone.
492 *
493 * Pzonepath() takes a path and attempts to resolve it relative to the
494 * root associated with the current process handle. If it fails it will
495 * not update the results string. It is safe to specify the same pointer
496 * for the file string and the results string.
497 *
498 * Doing this resolution is more difficult than it initially sounds.
499 * We can't simply append the file path to the zone root, because in
500 * a root directory, '..' is treated the same as '.'. Also, symbolic
501 * links that specify an absolute path need to be interpreted relative
502 * to the zone root.
503 *
504 * It seems like perhaps we could do a chroot(<zone root>) followed by a
505 * resolvepath(). But we can't do this because chroot requires special
506 * privileges and affects the entire process. Perhaps if there was a
507 * special version of resolvepath() which took an addition root path
508 * we could use that, but this isn't ideal either. The reason is
509 * that we want to have special handling for native paths. (A native path
510 * is a path that begins with "/native/" or "/.SUNWnative/".) Native
511 * paths could be passed explicity to this function or could be embedded
512 * in a symlink that is part of the path passed into this function.
513 * These paths are always lofs mounts of global zone paths, but lofs
514 * mounts only exist when a zone is booted. So if we were to try to do
515 * a resolvepath() on a native path when the zone wasn't booted the
516 * resolvepath() would fail even though we know that the components
517 * exists in the global zone.
518 *
519 * Given all these constraints, we just implement a path walking function
520 * that resolves a file path relative to a zone root by manually inspecting
521 * each of the path components and verifying its existence. This means that
522 * we must have access to the zone and that all the components of the
523 * path must exist for this operation to succeed.
524 */
525 char *
526 Pzonepath(struct ps_prochandle *P, const char *path, char *s, size_t n)
527 {
528 char zroot[PATH_MAX], zpath[PATH_MAX], tmp[PATH_MAX], link[PATH_MAX];
529 path_node_t *pn_stack = NULL, *pn_links = NULL, *pn;
530 struct stat64 sb;
531 char *p;
532 int i, rv;
533
534 dprintf("Pzonepath lookup '%s'\n", path);
535
536 /* First lookup the zone root */
537 if (Pzoneroot(P, zroot, sizeof (zroot)) == NULL)
538 return (NULL);
539
540 /*
541 * Make a temporary copy of the path specified.
542 * If it's a relative path then make it into an absolute path.
543 */
544 tmp[0] = '\0';
545 if (path[0] != '/')
546 (void) strlcat(tmp, "/", sizeof (tmp));
547 (void) strlcat(tmp, path, sizeof (tmp));
548
549 /*
550 * If the path that was passed in is the zone root, we're done.
551 * If the path that was passed in already contains the zone root
552 * then strip the zone root out and verify the rest of the path.
553 */
554 if (strcmp(tmp, zroot) == 0) {
555 (void) Plofspath(zroot, zroot, sizeof (zroot));
556 dprintf("Pzonepath found zone path (1) '%s'\n", zroot);
557 (void) strlcpy(s, zroot, n);
558 return (s);
559 }
560 i = strlen(zroot);
561 if ((strncmp(tmp, zroot, i) == 0) && (tmp[i] == '/'))
562 (void) memmove(tmp, tmp + i, strlen(tmp + i) + 1);
563
564 /* If no path is passed in, then it maps to the zone root */
565 if (strlen(tmp) == 0) {
566 (void) Plofspath(zroot, zroot, sizeof (zroot));
567 dprintf("Pzonepath found zone path (2) '%s'\n", zroot);
568 (void) strlcpy(s, zroot, n);
569 return (s);
570 }
571
572 /*
573 * Push each path component that we plan to verify onto a stack of
574 * path components, with parent components at the top of the stack.
575 * So for example, if we're going to verify the path /foo/bar/bang
576 * then our stack will look like:
577 * foo (top)
578 * bar
579 * bang (bottom)
580 */
581 while ((p = strrchr(tmp, '/')) != NULL) {
582 *p = '\0';
583 if (pn_push(&pn_stack, &p[1]) != NULL)
584 continue;
585 pn_free(&pn_stack);
586 return (NULL);
587 }
588
589 /* We're going to store the final zone relative path in zpath */
590 *zpath = '\0';
591
592 while (pn_pop(&pn_stack, tmp) != NULL) {
593 /*
594 * Drop zero length path components (which come from
595 * consecutive '/'s) and '.' path components.
596 */
597 if ((strlen(tmp) == 0) || (strcmp(tmp, ".") == 0))
598 continue;
599
600 /*
601 * Check the current path component for '..', if found
602 * drop any previous path component.
603 */
604 if (strcmp(tmp, "..") == 0) {
605 if ((p = strrchr(zpath, '/')) != NULL)
606 *p = '\0';
607 continue;
608 }
609
610 /* The path we want to verify now is zpath + / + tmp. */
611 (void) strlcat(zpath, "/", sizeof (zpath));
612 (void) strlcat(zpath, tmp, sizeof (zpath));
613
614 /*
615 * Check if this is a native object. A native object is an
616 * object from the global zone that is running in a branded
617 * zone. These objects are lofs mounted into a zone. So if a
618 * branded zone is not booted then lofs mounts won't be setup
619 * so we won't be able to find these objects. Luckily, we know
620 * that they exist in the global zone with the same path sans
621 * the initial native component, so we'll just strip out the
622 * native component here.
623 */
624 if ((strncmp(zpath, "/native", sizeof ("/native")) == 0) ||
625 (strncmp(zpath, "/.SUNWnative",
626 sizeof ("/.SUNWnative")) == 0)) {
627
628 /* Free any cached symlink paths */
629 pn_free(&pn_links);
630
631 /* Reconstruct the path from our path component stack */
632 *zpath = '\0';
633 while (pn_pop(&pn_stack, tmp) != NULL) {
634 (void) strlcat(zpath, "/", sizeof (zpath));
635 (void) strlcat(zpath, tmp, sizeof (zpath));
636 }
637
638 /* Verify that the path actually exists */
639 rv = resolvepath(zpath, tmp, sizeof (tmp) - 1);
640 if (rv < 0) {
641 dprintf("Pzonepath invalid native path '%s'\n",
642 zpath);
643 return (NULL);
644 }
645 tmp[rv] = '\0';
646
647 /* Return the path */
648 dprintf("Pzonepath found native path '%s'\n", tmp);
649 (void) Plofspath(tmp, tmp, sizeof (tmp));
650 (void) strlcpy(s, tmp, n);
651 return (s);
652 }
653
654 /*
655 * Check if the path points to a symlink. We do this
656 * explicitly since any absolute symlink needs to be
657 * interpreted relativly to the zone root and not "/".
658 */
659 (void) strlcpy(tmp, zroot, sizeof (tmp));
660 (void) strlcat(tmp, zpath, sizeof (tmp));
661 if (lstat64(tmp, &sb) != 0) {
662 pn_free2(&pn_stack, &pn_links);
663 return (NULL);
664 }
665 if (!S_ISLNK(sb.st_mode)) {
666 /*
667 * Since the lstat64() above succeeded we know that
668 * zpath exists, since this is not a symlink loop
669 * around and check the next path component.
670 */
671 continue;
672 }
673
674 /*
675 * Symlink allow for paths with loops. Make sure
676 * we're not stuck in a loop.
677 */
678 for (pn = pn_links; pn != NULL; pn = pn->pn_next) {
679 if (strcmp(zpath, pn->pn_path) != 0)
680 continue;
681
682 /* We have a loop. Fail. */
683 dprintf("Pzonepath symlink loop '%s'\n", zpath);
684 pn_free2(&pn_stack, &pn_links);
685 return (NULL);
686 }
687
688 /* Save this symlink path for future loop checks */
689 if (pn_push(&pn_links, zpath) == NULL) {
690 /* Out of memory */
691 pn_free2(&pn_stack, &pn_links);
692 return (NULL);
693 }
694
695 /* Now follow the contents of the symlink */
696 bzero(link, sizeof (link));
697 if (readlink(tmp, link, sizeof (link)) == -1) {
698 pn_free2(&pn_stack, &pn_links);
699 return (NULL);
700 }
701
702 dprintf("Pzonepath following symlink '%s' -> '%s'\n",
703 zpath, link);
704
705 /*
706 * Push each path component of the symlink target onto our
707 * path components stack since we need to verify each one.
708 */
709 while ((p = strrchr(link, '/')) != NULL) {
710 *p = '\0';
711 if (pn_push(&pn_stack, &p[1]) != NULL)
712 continue;
713 pn_free2(&pn_stack, &pn_links);
714 return (NULL);
715 }
716
717 /* absolute or relative symlink? */
718 if (*link == '\0') {
719 /* Absolute symlink, nuke existing zpath. */
720 *zpath = '\0';
721 continue;
722 }
723
724 /*
725 * Relative symlink. Push the first path component of the
726 * symlink target onto our stack for verification and then
727 * remove the current path component from zpath.
728 */
729 if (pn_push(&pn_stack, link) == NULL) {
730 pn_free2(&pn_stack, &pn_links);
731 return (NULL);
732 }
733 p = strrchr(zpath, '/');
734 assert(p != NULL);
735 *p = '\0';
736 continue;
737 }
738 pn_free(&pn_links);
739
740 /* Place the final result in zpath */
741 (void) strlcpy(tmp, zroot, sizeof (tmp));
742 (void) strlcat(tmp, zpath, sizeof (tmp));
743 (void) strlcpy(zpath, tmp, sizeof (zpath));
744
745 (void) Plofspath(zpath, zpath, sizeof (zpath));
746 dprintf("Pzonepath found zone path (3) '%s'\n", zpath);
747
748 (void) strlcpy(s, zpath, n);
749 return (s);
750 }
751
752 char *
753 Pfindobj(struct ps_prochandle *P, const char *path, char *s, size_t n)
754 {
755 int len;
756
757 dprintf("Pfindobj '%s'\n", path);
758
759 /* We only deal with absolute paths */
760 if (path[0] != '/')
761 return (NULL);
762
763 /* First try to resolve the path to some zone */
764 if (Pzonepath(P, path, s, n) != NULL)
765 return (s);
766
767 /* If that fails resolve any lofs links in the path */
768 if (Plofspath(path, s, n) != NULL)
769 return (s);
770
771 /* If that fails then just see if the path exists */
772 if ((len = resolvepath(path, s, n)) > 0) {
773 s[len] = '\0';
774 return (s);
775 }
776
777 return (NULL);
778 }
779
780 char *
781 Pfindmap(struct ps_prochandle *P, map_info_t *mptr, char *s, size_t n)
782 {
783 file_info_t *fptr = mptr->map_file;
784 char buf[PATH_MAX];
785 int len;
786
787 /* If it's already been explicity set return that */
788 if ((fptr != NULL) && (fptr->file_rname != NULL)) {
789 (void) strlcpy(s, fptr->file_rname, n);
790 return (s);
791 }
792
793 /* If it's the a.out segment, defer to the magical Pexecname() */
794 if ((P->map_exec == mptr) ||
795 (strcmp(mptr->map_pmap.pr_mapname, "a.out") == 0) ||
796 ((fptr != NULL) && (fptr->file_lname != NULL) &&
797 (strcmp(fptr->file_lname, "a.out") == 0))) {
798 if (Pexecname(P, buf, sizeof (buf)) != NULL) {
799 (void) strlcpy(s, buf, n);
800 return (s);
801 }
802 }
803
804 /* Try /proc first to get the real object name */
805 if ((Pstate(P) != PS_DEAD) && (mptr->map_pmap.pr_mapname[0] != '\0')) {
806 (void) snprintf(buf, sizeof (buf), "%s/%d/path/%s",
807 procfs_path, (int)P->pid, mptr->map_pmap.pr_mapname);
808 if ((len = readlink(buf, buf, sizeof (buf))) > 0) {
809 buf[len] = '\0';
810 (void) Plofspath(buf, buf, sizeof (buf));
811 (void) strlcpy(s, buf, n);
812 return (s);
813 }
814 }
815
816 /*
817 * If we couldn't get the name from /proc, take the lname and
818 * try to expand it on the current system to a real object path.
819 */
820 fptr = mptr->map_file;
821 if ((fptr != NULL) && (fptr->file_lname != NULL)) {
822 (void) strlcpy(buf, fptr->file_lname, sizeof (buf));
823 if (Pfindobj(P, buf, buf, sizeof (buf)) == NULL)
824 return (NULL);
825 (void) strlcpy(s, buf, n);
826 return (s);
827 }
828
829 return (NULL);
830 }