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 2010 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 * Copyright 2011 Joyent, Inc. All rights reserved.
26 */
27
28 /*
29 * The dlmgmtd daemon is started by the datalink-management SMF service.
30 * This daemon is used to manage <link name, linkid> mapping and the
31 * persistent datalink configuration.
32 *
33 * Today, the <link name, linkid> mapping and the persistent configuration
34 * of datalinks is kept in /etc/dladm/datalink.conf, and the daemon keeps
35 * a copy of the datalinks in the memory (see dlmgmt_id_avl and
36 * dlmgmt_name_avl). The active <link name, linkid> mapping is kept in
37 * /etc/svc/volatile/dladm cache file, so that the mapping can be recovered
38 * when dlmgmtd exits for some reason (e.g., when dlmgmtd is accidentally
39 * killed).
40 */
41
42 #include <assert.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <priv.h>
46 #include <signal.h>
47 #include <stdlib.h>
48 #include <stdio.h>
49 #include <strings.h>
50 #include <syslog.h>
51 #include <zone.h>
52 #include <sys/dld.h>
53 #include <sys/dld_ioc.h>
54 #include <sys/param.h>
55 #include <sys/stat.h>
56 #include <unistd.h>
57 #include <libdladm_impl.h>
58 #include <libdlmgmt.h>
59 #include "dlmgmt_impl.h"
60
61 const char *progname;
62 boolean_t debug;
63 static int pfds[2];
64 /*
65 * This file descriptor to DLMGMT_DOOR cannot be in the libdladm
66 * handle because the door isn't created when the handle is created.
67 */
68 static int dlmgmt_door_fd = -1;
69
70 /*
71 * This libdladm handle is global so that dlmgmt_upcall_linkprop_init() can
72 * pass to libdladm. The handle is opened with "ALL" privileges, before
73 * privileges are dropped in dlmgmt_drop_privileges(). It is not able to open
74 * DLMGMT_DOOR at that time as it hasn't been created yet. This door in the
75 * handle is opened in the first call to dladm_door_fd().
76 */
77 dladm_handle_t dld_handle = NULL;
78
79 static void dlmgmtd_exit(int);
80 static int dlmgmt_init();
81 static void dlmgmt_fini();
82 static int dlmgmt_set_privileges();
83
84 static int
85 dlmgmt_set_doorfd(boolean_t start)
86 {
87 dld_ioc_door_t did;
88 int err = 0;
89
90 assert(dld_handle != NULL);
91
92 did.did_start_door = start;
93
94 if (ioctl(dladm_dld_fd(dld_handle), DLDIOC_DOORSERVER, &did) == -1)
95 err = errno;
96
97 return (err);
98 }
99
100 static int
101 dlmgmt_door_init(void)
102 {
103 int err = 0;
104
105 if ((dlmgmt_door_fd = door_create(dlmgmt_handler, NULL,
106 DOOR_REFUSE_DESC | DOOR_NO_CANCEL)) == -1) {
107 err = errno;
108 dlmgmt_log(LOG_ERR, "door_create() failed: %s",
109 strerror(err));
110 return (err);
111 }
112 return (err);
113 }
114
115 static void
116 dlmgmt_door_fini(void)
117 {
118 if (dlmgmt_door_fd == -1)
119 return;
120
121 if (door_revoke(dlmgmt_door_fd) == -1) {
122 dlmgmt_log(LOG_WARNING, "door_revoke(%s) failed: %s",
123 DLMGMT_DOOR, strerror(errno));
124 }
125 (void) dlmgmt_set_doorfd(B_FALSE);
126 dlmgmt_door_fd = -1;
127 }
128
129 static int
130 dlmgmt_door_attach(zoneid_t zoneid, char *rootdir)
131 {
132 int fd;
133 int err = 0;
134 char doorpath[MAXPATHLEN];
135
136 (void) snprintf(doorpath, sizeof (doorpath), "%s%s", rootdir,
137 DLMGMT_DOOR);
138
139 /*
140 * Create the door file for dlmgmtd.
141 */
142 if ((fd = open(doorpath, O_CREAT|O_RDONLY, 0644)) == -1) {
143 err = errno;
144 dlmgmt_log(LOG_ERR, "open(%s) failed: %s", doorpath,
145 strerror(err));
146 return (err);
147 }
148 (void) close(fd);
149 if (chown(doorpath, UID_DLADM, GID_NETADM) == -1)
150 return (errno);
151
152 /*
153 * fdetach first in case a previous daemon instance exited
154 * ungracefully.
155 */
156 (void) fdetach(doorpath);
157 if (fattach(dlmgmt_door_fd, doorpath) != 0) {
158 err = errno;
159 dlmgmt_log(LOG_ERR, "fattach(%s) failed: %s", doorpath,
160 strerror(err));
161 } else if (zoneid == GLOBAL_ZONEID) {
162 if ((err = dlmgmt_set_doorfd(B_TRUE)) != 0) {
163 dlmgmt_log(LOG_ERR, "cannot set kernel doorfd: %s",
164 strerror(err));
165 }
166 }
167
168 return (err);
169 }
170
171 /*
172 * Create the /etc/svc/volatile/dladm/ directory if it doesn't exist, load the
173 * datalink.conf data for this zone, and create/attach the door rendezvous
174 * file.
175 */
176 int
177 dlmgmt_zone_init(zoneid_t zoneid)
178 {
179 char rootdir[MAXPATHLEN], tmpfsdir[MAXPATHLEN];
180 int err;
181 struct stat statbuf;
182
183 if (zoneid == GLOBAL_ZONEID) {
184 rootdir[0] = '\0';
185 } else if (zone_getattr(zoneid, ZONE_ATTR_ROOT, rootdir,
186 sizeof (rootdir)) < 0) {
187 return (errno);
188 }
189
190 /*
191 * Create the DLMGMT_TMPFS_DIR directory.
192 */
193 (void) snprintf(tmpfsdir, sizeof (tmpfsdir), "%s%s", rootdir,
194 DLMGMT_TMPFS_DIR);
195 if (stat(tmpfsdir, &statbuf) < 0) {
196 if (mkdir(tmpfsdir, (mode_t)0755) < 0)
197 return (errno);
198 } else if ((statbuf.st_mode & S_IFMT) != S_IFDIR) {
199 return (ENOTDIR);
200 }
201
202 if ((chmod(tmpfsdir, 0755) < 0) ||
203 (chown(tmpfsdir, UID_DLADM, GID_NETADM) < 0)) {
204 return (EPERM);
205 }
206
207 if ((err = dlmgmt_db_init(zoneid, rootdir)) != 0)
208 return (err);
209 return (dlmgmt_door_attach(zoneid, rootdir));
210 }
211
212 /*
213 * Initialize each running zone.
214 */
215 static int
216 dlmgmt_allzones_init(void)
217 {
218 int i;
219 zoneid_t *zids = NULL;
220 uint_t nzids, nzids_saved;
221
222 if (zone_list(NULL, &nzids) != 0)
223 return (errno);
224 again:
225 nzids *= 2;
226 if ((zids = malloc(nzids * sizeof (zoneid_t))) == NULL)
227 return (errno);
228 nzids_saved = nzids;
229 if (zone_list(zids, &nzids) != 0) {
230 free(zids);
231 return (errno);
232 }
233 if (nzids > nzids_saved) {
234 free(zids);
235 goto again;
236 }
237
238 for (i = 0; i < nzids; i++) {
239 int res;
240 zone_status_t status;
241
242 /*
243 * Skip over zones that have gone away or are going down
244 * since we got the list. Process all zones in the list,
245 * logging errors for any that failed.
246 */
247 if (zone_getattr(zids[i], ZONE_ATTR_STATUS, &status,
248 sizeof (status)) < 0)
249 continue;
250 switch (status) {
251 case ZONE_IS_SHUTTING_DOWN:
252 case ZONE_IS_EMPTY:
253 case ZONE_IS_DOWN:
254 case ZONE_IS_DYING:
255 case ZONE_IS_DEAD:
256 /* FALLTHRU */
257 continue;
258 }
259 if ((res = dlmgmt_zone_init(zids[i])) != 0) {
260 (void) fprintf(stderr, "zone (%ld) init error %s",
261 zids[i], strerror(res));
262 dlmgmt_log(LOG_ERR, "zone (%d) init error %s",
263 zids[i], strerror(res));
264 }
265 }
266 free(zids);
267 return (0);
268 }
269
270 static int
271 dlmgmt_init(void)
272 {
273 int err;
274 char *fmri, *c;
275 char filename[MAXPATHLEN];
276
277 if (dladm_open(&dld_handle) != DLADM_STATUS_OK) {
278 dlmgmt_log(LOG_ERR, "dladm_open() failed");
279 return (EPERM);
280 }
281
282 if (signal(SIGTERM, dlmgmtd_exit) == SIG_ERR ||
283 signal(SIGINT, dlmgmtd_exit) == SIG_ERR) {
284 err = errno;
285 dlmgmt_log(LOG_ERR, "signal() for SIGTERM/INT failed: %s",
286 strerror(err));
287 return (err);
288 }
289
290 (void) unlink(ZONE_LOCK);
291
292 /*
293 * First derive the name of the cache file from the FMRI name. This
294 * cache name is used to keep active datalink configuration.
295 */
296 if (debug) {
297 (void) snprintf(cachefile, MAXPATHLEN, "%s/%s%s",
298 DLMGMT_TMPFS_DIR, progname, ".debug.cache");
299 } else {
300 if ((fmri = getenv("SMF_FMRI")) == NULL) {
301 dlmgmt_log(LOG_ERR, "dlmgmtd is an smf(5) managed "
302 "service and should not be run from the command "
303 "line.");
304 return (EINVAL);
305 }
306
307 /*
308 * The FMRI name is in the form of
309 * svc:/service/service:instance. We need to remove the
310 * prefix "svc:/" and replace '/' with '-'. The cache file
311 * name is in the form of "service:instance.cache".
312 */
313 if ((c = strchr(fmri, '/')) != NULL)
314 c++;
315 else
316 c = fmri;
317 (void) snprintf(filename, MAXPATHLEN, "%s.cache", c);
318 c = filename;
319 while ((c = strchr(c, '/')) != NULL)
320 *c = '-';
321
322 (void) snprintf(cachefile, MAXPATHLEN, "%s/%s",
323 DLMGMT_TMPFS_DIR, filename);
324 }
325
326 dlmgmt_linktable_init();
327 if ((err = dlmgmt_door_init()) != 0)
328 goto done;
329
330 /*
331 * Load datalink configuration and create dlmgmtd door files for all
332 * currently running zones.
333 */
334 if ((err = dlmgmt_allzones_init()) != 0)
335 dlmgmt_door_fini();
336
337 done:
338 if (err != 0)
339 dlmgmt_linktable_fini();
340 return (err);
341 }
342
343 static void
344 dlmgmt_fini(void)
345 {
346 dlmgmt_door_fini();
347 dlmgmt_linktable_fini();
348 if (dld_handle != NULL) {
349 dladm_close(dld_handle);
350 dld_handle = NULL;
351 }
352 }
353
354 /*
355 * This is called by the child process to inform the parent process to
356 * exit with the given return value.
357 */
358 static void
359 dlmgmt_inform_parent_exit(int rv)
360 {
361 if (debug)
362 return;
363
364 if (write(pfds[1], &rv, sizeof (int)) != sizeof (int)) {
365 dlmgmt_log(LOG_WARNING,
366 "dlmgmt_inform_parent_exit() failed: %s", strerror(errno));
367 (void) close(pfds[1]);
368 exit(EXIT_FAILURE);
369 }
370 (void) close(pfds[1]);
371 }
372
373 /*ARGSUSED*/
374 static void
375 dlmgmtd_exit(int signo)
376 {
377 (void) close(pfds[1]);
378 dlmgmt_fini();
379 exit(EXIT_FAILURE);
380 }
381
382 static void
383 usage(void)
384 {
385 (void) fprintf(stderr, "Usage: %s [-d]\n", progname);
386 exit(EXIT_FAILURE);
387 }
388
389 /*
390 * Restrict privileges to only those needed.
391 */
392 int
393 dlmgmt_drop_privileges(void)
394 {
395 priv_set_t *pset;
396 priv_ptype_t ptype;
397 zoneid_t zoneid = getzoneid();
398 int err = 0;
399
400 if ((pset = priv_allocset()) == NULL)
401 return (errno);
402
403 /*
404 * The global zone needs PRIV_PROC_FORK so that it can fork() when it
405 * issues db ops in non-global zones, PRIV_SYS_CONFIG to post
406 * sysevents, and PRIV_SYS_DL_CONFIG to initialize link properties in
407 * dlmgmt_upcall_linkprop_init().
408 *
409 * We remove non-basic privileges from the permitted (and thus
410 * effective) set. When executing in a non-global zone, dlmgmtd
411 * only needs to read and write to files that it already owns.
412 */
413 priv_basicset(pset);
414 (void) priv_delset(pset, PRIV_PROC_EXEC);
415 (void) priv_delset(pset, PRIV_PROC_INFO);
416 (void) priv_delset(pset, PRIV_PROC_SESSION);
417 (void) priv_delset(pset, PRIV_FILE_LINK_ANY);
418 if (zoneid == GLOBAL_ZONEID) {
419 ptype = PRIV_EFFECTIVE;
420 if (priv_addset(pset, PRIV_SYS_CONFIG) == -1 ||
421 priv_addset(pset, PRIV_SYS_DL_CONFIG) == -1)
422 err = errno;
423 } else {
424 (void) priv_delset(pset, PRIV_PROC_FORK);
425 ptype = PRIV_PERMITTED;
426 }
427 if (err == 0 && setppriv(PRIV_SET, ptype, pset) == -1)
428 err = errno;
429 done:
430 priv_freeset(pset);
431 return (err);
432 }
433
434 int
435 dlmgmt_elevate_privileges(void)
436 {
437 priv_set_t *privset;
438 int err = 0;
439
440 if ((privset = priv_str_to_set("zone", ",", NULL)) == NULL)
441 return (errno);
442 if (setppriv(PRIV_SET, PRIV_EFFECTIVE, privset) == -1)
443 err = errno;
444 priv_freeset(privset);
445 return (err);
446 }
447
448 /*
449 * Set the uid of this daemon to the "dladm" user and drop privileges to only
450 * those needed.
451 */
452 static int
453 dlmgmt_set_privileges(void)
454 {
455 int err;
456
457 (void) setgroups(0, NULL);
458 if (setegid(GID_NETADM) == -1 || seteuid(UID_DLADM) == -1)
459 err = errno;
460 else
461 err = dlmgmt_drop_privileges();
462 done:
463 return (err);
464 }
465
466 /*
467 * Keep the pfds fd open, close other fds.
468 */
469 /*ARGSUSED*/
470 static int
471 closefunc(void *arg, int fd)
472 {
473 if (fd != pfds[1])
474 (void) close(fd);
475 return (0);
476 }
477
478 static boolean_t
479 dlmgmt_daemonize(void)
480 {
481 pid_t pid;
482 int rv;
483
484 if (pipe(pfds) < 0) {
485 (void) fprintf(stderr, "%s: pipe() failed: %s\n",
486 progname, strerror(errno));
487 exit(EXIT_FAILURE);
488 }
489
490 if ((pid = fork()) == -1) {
491 (void) fprintf(stderr, "%s: fork() failed: %s\n",
492 progname, strerror(errno));
493 exit(EXIT_FAILURE);
494 } else if (pid > 0) { /* Parent */
495 (void) close(pfds[1]);
496
497 /*
498 * Read the child process's return value from the pfds.
499 * If the child process exits unexpected, read() returns -1.
500 */
501 if (read(pfds[0], &rv, sizeof (int)) != sizeof (int)) {
502 (void) kill(pid, SIGKILL);
503 rv = EXIT_FAILURE;
504 }
505
506 (void) close(pfds[0]);
507 exit(rv);
508 }
509
510 /* Child */
511 (void) close(pfds[0]);
512 (void) setsid();
513
514 /*
515 * Close all files except pfds[1].
516 */
517 (void) fdwalk(closefunc, NULL);
518 (void) chdir("/");
519 openlog(progname, LOG_PID, LOG_DAEMON);
520 return (B_TRUE);
521 }
522
523 int
524 main(int argc, char *argv[])
525 {
526 int opt, err;
527
528 progname = strrchr(argv[0], '/');
529 if (progname != NULL)
530 progname++;
531 else
532 progname = argv[0];
533
534 /*
535 * Process options.
536 */
537 while ((opt = getopt(argc, argv, "d")) != EOF) {
538 switch (opt) {
539 case 'd':
540 debug = B_TRUE;
541 break;
542 default:
543 usage();
544 }
545 }
546
547 if (!debug && !dlmgmt_daemonize())
548 return (EXIT_FAILURE);
549
550 if ((err = dlmgmt_init()) != 0) {
551 dlmgmt_log(LOG_ERR, "unable to initialize daemon: %s",
552 strerror(err));
553 goto child_out;
554 } else if ((err = dlmgmt_set_privileges()) != 0) {
555 dlmgmt_log(LOG_ERR, "unable to set daemon privileges: %s",
556 strerror(err));
557 dlmgmt_fini();
558 goto child_out;
559 }
560
561 /*
562 * Inform the parent process that it can successfully exit.
563 */
564 dlmgmt_inform_parent_exit(EXIT_SUCCESS);
565
566 for (;;)
567 (void) pause();
568
569 child_out:
570 /* return from main() forcibly exits an MT process */
571 dlmgmt_inform_parent_exit(EXIT_FAILURE);
572 return (EXIT_FAILURE);
573 }