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