xref: /illumos-gate/usr/src/cmd/dlmgmtd/dlmgmt_db.c (revision 8de1eb2b53a3cc425a3504195db75618feef9044)
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  */
26 
27 #include <assert.h>
28 #include <ctype.h>
29 #include <errno.h>
30 #include <fcntl.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <strings.h>
35 #include <syslog.h>
36 #include <zone.h>
37 #include <sys/types.h>
38 #include <sys/stat.h>
39 #include <stropts.h>
40 #include <sys/conf.h>
41 #include <pthread.h>
42 #include <unistd.h>
43 #include <wait.h>
44 #include <libcontract.h>
45 #include <sys/contract/process.h>
46 #include "dlmgmt_impl.h"
47 
48 typedef enum dlmgmt_db_op {
49 	DLMGMT_DB_OP_WRITE,
50 	DLMGMT_DB_OP_DELETE,
51 	DLMGMT_DB_OP_READ
52 } dlmgmt_db_op_t;
53 
54 typedef struct dlmgmt_db_req_s {
55 	struct dlmgmt_db_req_s	*ls_next;
56 	dlmgmt_db_op_t		ls_op;
57 	char			ls_link[MAXLINKNAMELEN];
58 	datalink_id_t		ls_linkid;
59 	zoneid_t		ls_zoneid;
60 	uint32_t		ls_flags;	/* Either DLMGMT_ACTIVE or   */
61 						/* DLMGMT_PERSIST, not both. */
62 } dlmgmt_db_req_t;
63 
64 /*
65  * List of pending db updates (e.g., because of a read-only filesystem).
66  */
67 static dlmgmt_db_req_t	*dlmgmt_db_req_head = NULL;
68 static dlmgmt_db_req_t	*dlmgmt_db_req_tail = NULL;
69 
70 /*
71  * rewrite_needed is set to B_TRUE by process_link_line() if it encounters a
72  * line with an old format.  This will cause the file being read to be
73  * re-written with the current format.
74  */
75 static boolean_t	rewrite_needed;
76 
77 static int		dlmgmt_db_update(dlmgmt_db_op_t, const char *,
78 			    dlmgmt_link_t *, uint32_t);
79 static int		dlmgmt_process_db_req(dlmgmt_db_req_t *);
80 static int		dlmgmt_process_db_onereq(dlmgmt_db_req_t *, boolean_t);
81 static void		*dlmgmt_db_update_thread(void *);
82 static boolean_t	process_link_line(char *, dlmgmt_link_t *);
83 static int		process_db_write(dlmgmt_db_req_t *, FILE *, FILE *);
84 static int		process_db_read(dlmgmt_db_req_t *, FILE *);
85 static void		generate_link_line(dlmgmt_link_t *, boolean_t, char *);
86 
87 #define	BUFLEN(lim, ptr)	(((lim) > (ptr)) ? ((lim) - (ptr)) : 0)
88 #define	MAXLINELEN		1024
89 
90 typedef void db_walk_func_t(dlmgmt_link_t *);
91 
92 /*
93  * Translator functions to go from dladm_datatype_t to character strings.
94  * Each function takes a pointer to a buffer, the size of the buffer,
95  * the name of the attribute, and the value to be written.  The functions
96  * return the number of bytes written to the buffer.  If the buffer is not big
97  * enough to hold the string representing the value, then nothing is written
98  * and 0 is returned.
99  */
100 typedef size_t write_func_t(char *, size_t, char *, void *);
101 
102 /*
103  * Translator functions to read from a NULL terminated string buffer into
104  * something of the given DLADM_TYPE_*.  The functions each return the number
105  * of bytes read from the string buffer.  If there is an error reading data
106  * from the buffer, then 0 is returned.  It is the caller's responsibility
107  * to free the data allocated by these functions.
108  */
109 typedef size_t read_func_t(char *, void **);
110 
111 typedef struct translator_s {
112 	const char	*type_name;
113 	write_func_t	*write_func;
114 	read_func_t	*read_func;
115 } translator_t;
116 
117 /*
118  * Translator functions, defined later but declared here so that
119  * the translator table can be defined.
120  */
121 static write_func_t	write_str, write_boolean, write_uint64;
122 static read_func_t	read_str, read_boolean, read_int64;
123 
124 /*
125  * Translator table, indexed by dladm_datatype_t.
126  */
127 static translator_t translators[] = {
128 	{ "string",	write_str,	read_str	},
129 	{ "boolean",	write_boolean,	read_boolean	},
130 	{ "int",	write_uint64,	read_int64	}
131 };
132 
133 static size_t ntranslators = sizeof (translators) / sizeof (translator_t);
134 
135 #define	LINK_PROPERTY_DELIMINATOR	";"
136 #define	LINK_PROPERTY_TYPE_VALUE_SEP	","
137 #define	BASE_PROPERTY_LENGTH(t, n) (strlen(translators[(t)].type_name) +\
138 				    strlen(LINK_PROPERTY_TYPE_VALUE_SEP) +\
139 				    strlen(LINK_PROPERTY_DELIMINATOR) +\
140 				    strlen((n)))
141 #define	GENERATE_PROPERTY_STRING(buf, length, conv, name, type, val) \
142 	    (snprintf((buf), (length), "%s=%s%s" conv "%s", (name), \
143 	    translators[(type)].type_name, \
144 	    LINK_PROPERTY_TYPE_VALUE_SEP, (val), LINK_PROPERTY_DELIMINATOR))
145 
146 /*
147  * Name of the cache file to keep the active <link name, linkid> mapping
148  */
149 char	cachefile[MAXPATHLEN];
150 
151 #define	DLMGMT_PERSISTENT_DB_PATH	"/etc/dladm/datalink.conf"
152 #define	DLMGMT_MAKE_FILE_DB_PATH(buffer, persistent)	\
153 	(void) snprintf((buffer), MAXPATHLEN, "%s", \
154 	(persistent) ? DLMGMT_PERSISTENT_DB_PATH : cachefile);
155 
156 typedef struct zopen_arg {
157 	const char	*zopen_modestr;
158 	int		*zopen_pipe;
159 	int		zopen_fd;
160 } zopen_arg_t;
161 
162 typedef struct zrename_arg {
163 	const char	*zrename_newname;
164 } zrename_arg_t;
165 
166 typedef union zfoparg {
167 	zopen_arg_t	zfop_openarg;
168 	zrename_arg_t	zfop_renamearg;
169 } zfoparg_t;
170 
171 typedef struct zfcbarg {
172 	boolean_t	zfarg_inglobalzone; /* is callback in global zone? */
173 	zoneid_t	zfarg_finglobalzone; /* is file in global zone? */
174 	const char	*zfarg_filename;
175 	zfoparg_t	*zfarg_oparg;
176 } zfarg_t;
177 #define	zfarg_openarg	zfarg_oparg->zfop_openarg
178 #define	zfarg_renamearg	zfarg_oparg->zfop_renamearg
179 
180 /* zone file callback */
181 typedef int zfcb_t(zfarg_t *);
182 
183 /*
184  * Execute an operation on filename relative to zoneid's zone root.  If the
185  * file is in the global zone, then the zfcb() callback will simply be called
186  * directly.  If the file is in a non-global zone, then zfcb() will be called
187  * both from the global zone's context, and from the non-global zone's context
188  * (from a fork()'ed child that has entered the non-global zone).  This is
189  * done to allow the callback to communicate with itself if needed (e.g. to
190  * pass back the file descriptor of an opened file).
191  */
192 static int
193 dlmgmt_zfop(const char *filename, zoneid_t zoneid, zfcb_t *zfcb,
194     zfoparg_t *zfoparg)
195 {
196 	int		ctfd;
197 	int		err;
198 	pid_t		childpid;
199 	siginfo_t	info;
200 	zfarg_t		zfarg;
201 
202 	if (zoneid != GLOBAL_ZONEID) {
203 		/*
204 		 * We need to access a file that isn't in the global zone.
205 		 * Accessing non-global zone files from the global zone is
206 		 * unsafe (due to symlink attacks), we'll need to fork a child
207 		 * that enters the zone in question and executes the callback
208 		 * that will operate on the file.
209 		 *
210 		 * Before we proceed with this zone tango, we need to create a
211 		 * new process contract for the child, as required by
212 		 * zone_enter().
213 		 */
214 		errno = 0;
215 		ctfd = open64("/system/contract/process/template", O_RDWR);
216 		if (ctfd == -1)
217 			return (errno);
218 		if ((err = ct_tmpl_set_critical(ctfd, 0)) != 0 ||
219 		    (err = ct_tmpl_set_informative(ctfd, 0)) != 0 ||
220 		    (err = ct_pr_tmpl_set_fatal(ctfd, CT_PR_EV_HWERR)) != 0 ||
221 		    (err = ct_pr_tmpl_set_param(ctfd, CT_PR_PGRPONLY)) != 0 ||
222 		    (err = ct_tmpl_activate(ctfd)) != 0) {
223 			return (err);
224 		}
225 		childpid = fork();
226 		(void) ct_tmpl_clear(ctfd);
227 		(void) close(ctfd);
228 		switch (childpid) {
229 		case -1:
230 			return (err);
231 		case 0:
232 			/*
233 			 * Elevate our privileges as zone_enter() requires all
234 			 * privileges.
235 			 */
236 			if ((err = dlmgmt_elevate_privileges()) != 0)
237 				_exit(err);
238 			if (zone_enter(zoneid) == -1)
239 				_exit(errno);
240 			if ((err = dlmgmt_drop_privileges()) != 0)
241 				_exit(err);
242 			break;
243 		default:
244 			if (waitid(P_PID, childpid, &info, WEXITED) == -1)
245 				return (errno);
246 			if (info.si_status != 0)
247 				return (info.si_status);
248 		}
249 	}
250 
251 	zfarg.zfarg_inglobalzone = (zoneid == GLOBAL_ZONEID || childpid != 0);
252 	zfarg.zfarg_finglobalzone = (zoneid == GLOBAL_ZONEID);
253 	zfarg.zfarg_filename = filename;
254 	zfarg.zfarg_oparg = zfoparg;
255 	err = zfcb(&zfarg);
256 	if (!zfarg.zfarg_inglobalzone)
257 		_exit(err);
258 	return (err);
259 }
260 
261 static int
262 dlmgmt_zopen_cb(zfarg_t *zfarg)
263 {
264 	struct strrecvfd recvfd;
265 	boolean_t	newfile = B_FALSE;
266 	boolean_t	inglobalzone = zfarg->zfarg_inglobalzone;
267 	zoneid_t	finglobalzone = zfarg->zfarg_finglobalzone;
268 	const char	*filename = zfarg->zfarg_filename;
269 	const char	*modestr = zfarg->zfarg_openarg.zopen_modestr;
270 	int		*p = zfarg->zfarg_openarg.zopen_pipe;
271 	struct stat	statbuf;
272 	int		oflags;
273 	mode_t		mode;
274 	int		fd = -1;
275 	int		err;
276 
277 	/* We only ever open a file for reading or writing, not both. */
278 	oflags = (modestr[0] == 'r') ? O_RDONLY : O_WRONLY | O_CREAT | O_TRUNC;
279 	mode = (modestr[0] == 'r') ? 0 : S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
280 
281 	/* Open the file if we're in the same zone as the file. */
282 	if (inglobalzone == finglobalzone) {
283 		/*
284 		 * First determine if we will be creating the file as part of
285 		 * opening it.  If so, then we'll need to ensure that it has
286 		 * the proper ownership after having opened it.
287 		 */
288 		if (oflags & O_CREAT) {
289 			if (stat(filename, &statbuf) == -1) {
290 				if (errno == ENOENT)
291 					newfile = B_TRUE;
292 				else
293 					return (errno);
294 			}
295 		}
296 		if ((fd = open(filename, oflags, mode)) == -1)
297 			return (errno);
298 		if (newfile) {
299 			if (chown(filename, UID_DLADM, GID_NETADM) == -1) {
300 				err = errno;
301 				(void) close(fd);
302 				return (err);
303 			}
304 		}
305 	}
306 
307 	/*
308 	 * If we're not in the global zone, send the file-descriptor back to
309 	 * our parent in the global zone.
310 	 */
311 	if (!inglobalzone) {
312 		assert(!finglobalzone);
313 		assert(fd != -1);
314 		return (ioctl(p[1], I_SENDFD, fd) == -1 ? errno : 0);
315 	}
316 
317 	/*
318 	 * At this point, we know we're in the global zone.  If the file was
319 	 * in a non-global zone, receive the file-descriptor from our child in
320 	 * the non-global zone.
321 	 */
322 	if (!finglobalzone) {
323 		if (ioctl(p[0], I_RECVFD, &recvfd) == -1)
324 			return (errno);
325 		fd = recvfd.fd;
326 	}
327 
328 	zfarg->zfarg_openarg.zopen_fd = fd;
329 	return (0);
330 }
331 
332 static int
333 dlmgmt_zunlink_cb(zfarg_t *zfarg)
334 {
335 	if (zfarg->zfarg_inglobalzone != zfarg->zfarg_finglobalzone)
336 		return (0);
337 	return (unlink(zfarg->zfarg_filename) == 0 ? 0 : errno);
338 }
339 
340 static int
341 dlmgmt_zrename_cb(zfarg_t *zfarg)
342 {
343 	if (zfarg->zfarg_inglobalzone != zfarg->zfarg_finglobalzone)
344 		return (0);
345 	return (rename(zfarg->zfarg_filename,
346 	    zfarg->zfarg_renamearg.zrename_newname) == 0 ? 0 : errno);
347 }
348 
349 /*
350  * Same as fopen(3C), except that it opens the file relative to zoneid's zone
351  * root.
352  */
353 static FILE *
354 dlmgmt_zfopen(const char *filename, const char *modestr, zoneid_t zoneid,
355     int *err)
356 {
357 	int		p[2];
358 	zfoparg_t	zfoparg;
359 	FILE		*fp = NULL;
360 
361 	if (zoneid != GLOBAL_ZONEID && pipe(p) == -1) {
362 		*err = errno;
363 		return (NULL);
364 	}
365 
366 	zfoparg.zfop_openarg.zopen_modestr = modestr;
367 	zfoparg.zfop_openarg.zopen_pipe = p;
368 	*err = dlmgmt_zfop(filename, zoneid, dlmgmt_zopen_cb, &zfoparg);
369 	if (zoneid != GLOBAL_ZONEID) {
370 		(void) close(p[0]);
371 		(void) close(p[1]);
372 	}
373 	if (*err == 0) {
374 		fp = fdopen(zfoparg.zfop_openarg.zopen_fd, modestr);
375 		if (fp == NULL) {
376 			*err = errno;
377 			(void) close(zfoparg.zfop_openarg.zopen_fd);
378 		}
379 	}
380 	return (fp);
381 }
382 
383 /*
384  * Same as rename(2), except that old and new are relative to zoneid's zone
385  * root.
386  */
387 static int
388 dlmgmt_zrename(const char *old, const char *new, zoneid_t zoneid)
389 {
390 	zfoparg_t zfoparg;
391 
392 	zfoparg.zfop_renamearg.zrename_newname = new;
393 	return (dlmgmt_zfop(old, zoneid, dlmgmt_zrename_cb, &zfoparg));
394 }
395 
396 /*
397  * Same as unlink(2), except that filename is relative to zoneid's zone root.
398  */
399 static int
400 dlmgmt_zunlink(const char *filename, zoneid_t zoneid)
401 {
402 	return (dlmgmt_zfop(filename, zoneid, dlmgmt_zunlink_cb, NULL));
403 }
404 
405 static size_t
406 write_str(char *buffer, size_t buffer_length, char *name, void *value)
407 {
408 	char	*ptr = value;
409 	size_t	data_length = strnlen(ptr, buffer_length);
410 
411 	/*
412 	 * Strings are assumed to be NULL terminated.  In order to fit in
413 	 * the buffer, the string's length must be less then buffer_length.
414 	 * If the value is empty, there's no point in writing it, in fact,
415 	 * we shouldn't even see that case.
416 	 */
417 	if (data_length + BASE_PROPERTY_LENGTH(DLADM_TYPE_STR, name) ==
418 	    buffer_length || data_length == 0)
419 		return (0);
420 
421 	/*
422 	 * Since we know the string will fit in the buffer, snprintf will
423 	 * always return less than buffer_length, so we can just return
424 	 * whatever snprintf returns.
425 	 */
426 	return (GENERATE_PROPERTY_STRING(buffer, buffer_length, "%s",
427 	    name, DLADM_TYPE_STR, ptr));
428 }
429 
430 static size_t
431 write_boolean(char *buffer, size_t buffer_length, char *name, void *value)
432 {
433 	boolean_t	*ptr = value;
434 
435 	/*
436 	 * Booleans are either zero or one, so we only need room for two
437 	 * characters in the buffer.
438 	 */
439 	if (buffer_length <= 1 + BASE_PROPERTY_LENGTH(DLADM_TYPE_BOOLEAN, name))
440 		return (0);
441 
442 	return (GENERATE_PROPERTY_STRING(buffer, buffer_length, "%d",
443 	    name, DLADM_TYPE_BOOLEAN, *ptr));
444 }
445 
446 static size_t
447 write_uint64(char *buffer, size_t buffer_length, char *name, void *value)
448 {
449 	uint64_t	*ptr = value;
450 
451 	/*
452 	 * Limit checking for uint64_t is a little trickier.
453 	 */
454 	if (snprintf(NULL, 0, "%lld", *ptr)  +
455 	    BASE_PROPERTY_LENGTH(DLADM_TYPE_UINT64, name) >= buffer_length)
456 		return (0);
457 
458 	return (GENERATE_PROPERTY_STRING(buffer, buffer_length, "%lld",
459 	    name, DLADM_TYPE_UINT64, *ptr));
460 }
461 
462 static size_t
463 read_str(char *buffer, void **value)
464 {
465 	char		*ptr = calloc(MAXLINKATTRVALLEN, sizeof (char));
466 	ssize_t		len;
467 
468 	if (ptr == NULL || (len = strlcpy(ptr, buffer, MAXLINKATTRVALLEN))
469 	    >= MAXLINKATTRVALLEN) {
470 		free(ptr);
471 		return (0);
472 	}
473 
474 	*(char **)value = ptr;
475 
476 	/* Account for NULL terminator */
477 	return (len + 1);
478 }
479 
480 static size_t
481 read_boolean(char *buffer, void **value)
482 {
483 	boolean_t	*ptr = calloc(1, sizeof (boolean_t));
484 
485 	if (ptr == NULL)
486 		return (0);
487 
488 	*ptr = atoi(buffer);
489 	*(boolean_t **)value = ptr;
490 
491 	return (sizeof (boolean_t));
492 }
493 
494 static size_t
495 read_int64(char *buffer, void **value)
496 {
497 	int64_t	*ptr = calloc(1, sizeof (int64_t));
498 
499 	if (ptr == NULL)
500 		return (0);
501 
502 	*ptr = (int64_t)atoll(buffer);
503 	*(int64_t **)value = ptr;
504 
505 	return (sizeof (int64_t));
506 }
507 
508 static dlmgmt_db_req_t *
509 dlmgmt_db_req_alloc(dlmgmt_db_op_t op, const char *linkname,
510     datalink_id_t linkid, zoneid_t zoneid, uint32_t flags, int *err)
511 {
512 	dlmgmt_db_req_t *req;
513 
514 	if ((req = calloc(1, sizeof (dlmgmt_db_req_t))) == NULL) {
515 		*err = errno;
516 	} else {
517 		req->ls_op = op;
518 		if (linkname != NULL)
519 			(void) strlcpy(req->ls_link, linkname, MAXLINKNAMELEN);
520 		req->ls_linkid = linkid;
521 		req->ls_zoneid = zoneid;
522 		req->ls_flags = flags;
523 	}
524 	return (req);
525 }
526 
527 /*
528  * Update the db entry with name "entryname" using information from "linkp".
529  */
530 static int
531 dlmgmt_db_update(dlmgmt_db_op_t op, const char *entryname, dlmgmt_link_t *linkp,
532     uint32_t flags)
533 {
534 	dlmgmt_db_req_t	*req;
535 	int		err;
536 
537 	/* It is either a persistent request or an active request, not both. */
538 	assert((flags == DLMGMT_PERSIST) || (flags == DLMGMT_ACTIVE));
539 
540 	if ((req = dlmgmt_db_req_alloc(op, entryname, linkp->ll_linkid,
541 	    linkp->ll_zoneid, flags, &err)) == NULL)
542 		return (err);
543 
544 	/*
545 	 * If the return error is EINPROGRESS, this request is handled
546 	 * asynchronously; return success.
547 	 */
548 	err = dlmgmt_process_db_req(req);
549 	if (err != EINPROGRESS)
550 		free(req);
551 	else
552 		err = 0;
553 	return (err);
554 }
555 
556 #define	DLMGMT_DB_OP_STR(op)					\
557 	(((op) == DLMGMT_DB_OP_READ) ? "read" :			\
558 	(((op) == DLMGMT_DB_OP_WRITE) ? "write" : "delete"))
559 
560 #define	DLMGMT_DB_CONF_STR(flag)				\
561 	(((flag) == DLMGMT_ACTIVE) ? "active" :			\
562 	(((flag) == DLMGMT_PERSIST) ? "persistent" : ""))
563 
564 static int
565 dlmgmt_process_db_req(dlmgmt_db_req_t *req)
566 {
567 	pthread_t	tid;
568 	boolean_t	writeop;
569 	int		err;
570 
571 	/*
572 	 * If there are already pending "write" requests, queue this request in
573 	 * the pending list.  Note that this function is called while the
574 	 * dlmgmt_rw_lock is held, so it is safe to access the global variables.
575 	 */
576 	writeop = (req->ls_op != DLMGMT_DB_OP_READ);
577 	if (writeop && (req->ls_flags == DLMGMT_PERSIST) &&
578 	    (dlmgmt_db_req_head != NULL)) {
579 		dlmgmt_db_req_tail->ls_next = req;
580 		dlmgmt_db_req_tail = req;
581 		return (EINPROGRESS);
582 	}
583 
584 	err = dlmgmt_process_db_onereq(req, writeop);
585 	if (err != EINPROGRESS && err != 0 && err != ENOENT) {
586 		/*
587 		 * Log the error unless the request processing is still in
588 		 * progress or if the configuration file hasn't been created
589 		 * yet (ENOENT).
590 		 */
591 		dlmgmt_log(LOG_WARNING, "dlmgmt_process_db_onereq() %s "
592 		    "operation on %s configuration failed: %s",
593 		    DLMGMT_DB_OP_STR(req->ls_op),
594 		    DLMGMT_DB_CONF_STR(req->ls_flags), strerror(err));
595 	}
596 
597 	if (err == EINPROGRESS) {
598 		assert(req->ls_flags == DLMGMT_PERSIST);
599 		assert(writeop && dlmgmt_db_req_head == NULL);
600 		dlmgmt_db_req_tail = dlmgmt_db_req_head = req;
601 		err = pthread_create(&tid, NULL, dlmgmt_db_update_thread, NULL);
602 		if (err == 0)
603 			return (EINPROGRESS);
604 	}
605 	return (err);
606 }
607 
608 static int
609 dlmgmt_process_db_onereq(dlmgmt_db_req_t *req, boolean_t writeop)
610 {
611 	int	err = 0;
612 	FILE	*fp, *nfp = NULL;
613 	char	file[MAXPATHLEN];
614 	char	newfile[MAXPATHLEN];
615 
616 	DLMGMT_MAKE_FILE_DB_PATH(file, (req->ls_flags == DLMGMT_PERSIST));
617 	fp = dlmgmt_zfopen(file, "r", req->ls_zoneid, &err);
618 	/*
619 	 * Note that it is not an error if the file doesn't exist.  If we're
620 	 * reading, we treat this case the same way as an empty file.  If
621 	 * we're writing, the file will be created when we open the file for
622 	 * writing below.
623 	 */
624 	if (fp == NULL && !writeop)
625 		return (err);
626 
627 	if (writeop) {
628 		(void) snprintf(newfile, MAXPATHLEN, "%s.new", file);
629 		nfp = dlmgmt_zfopen(newfile, "w", req->ls_zoneid, &err);
630 		if (nfp == NULL) {
631 			/*
632 			 * EROFS can happen at boot when the file system is
633 			 * read-only.  Return EINPROGRESS so that the caller
634 			 * can add this request to the pending request list
635 			 * and start a retry thread.
636 			 */
637 			err = (errno == EROFS ? EINPROGRESS : errno);
638 			goto done;
639 		}
640 	}
641 	if (writeop) {
642 		if ((err = process_db_write(req, fp, nfp)) == 0)
643 			err = dlmgmt_zrename(newfile, file, req->ls_zoneid);
644 	} else {
645 		err = process_db_read(req, fp);
646 	}
647 
648 done:
649 	if (nfp != NULL) {
650 		(void) fclose(nfp);
651 		if (err != 0)
652 			(void) dlmgmt_zunlink(newfile, req->ls_zoneid);
653 	}
654 	(void) fclose(fp);
655 	return (err);
656 }
657 
658 /*ARGSUSED*/
659 static void *
660 dlmgmt_db_update_thread(void *arg)
661 {
662 	dlmgmt_db_req_t	*req;
663 
664 	dlmgmt_table_lock(B_TRUE);
665 
666 	assert(dlmgmt_db_req_head != NULL);
667 	while ((req = dlmgmt_db_req_head) != NULL) {
668 		assert(req->ls_flags == DLMGMT_PERSIST);
669 		if (dlmgmt_process_db_onereq(req, B_TRUE) == EINPROGRESS) {
670 			/*
671 			 * The filesystem is still read only. Go to sleep and
672 			 * try again.
673 			 */
674 			dlmgmt_table_unlock();
675 			(void) sleep(5);
676 			dlmgmt_table_lock(B_TRUE);
677 			continue;
678 		}
679 
680 		/*
681 		 * The filesystem is no longer read only. Continue processing
682 		 * and remove the request from the pending list.
683 		 */
684 		dlmgmt_db_req_head = req->ls_next;
685 		if (dlmgmt_db_req_tail == req) {
686 			assert(dlmgmt_db_req_head == NULL);
687 			dlmgmt_db_req_tail = NULL;
688 		}
689 		free(req);
690 	}
691 
692 	dlmgmt_table_unlock();
693 	return (NULL);
694 }
695 
696 static int
697 parse_linkprops(char *buf, dlmgmt_link_t *linkp)
698 {
699 	boolean_t		found_type = B_FALSE;
700 	dladm_datatype_t	type = DLADM_TYPE_STR;
701 	int			i, len;
702 	int			err = 0;
703 	char			*curr;
704 	char			attr_name[MAXLINKATTRLEN];
705 	size_t			attr_buf_len = 0;
706 	void			*attr_buf = NULL;
707 
708 	curr = buf;
709 	len = strlen(buf);
710 	attr_name[0] = '\0';
711 	for (i = 0; i < len && err == 0; i++) {
712 		char		c = buf[i];
713 		boolean_t	match = (c == '=' ||
714 		    (c == ',' && !found_type) || c == ';');
715 
716 		/*
717 		 * Move to the next character if there is no match and
718 		 * if we have not reached the last character.
719 		 */
720 		if (!match && i != len - 1)
721 			continue;
722 
723 		if (match) {
724 			/*
725 			 * NUL-terminate the string pointed to by 'curr'.
726 			 */
727 			buf[i] = '\0';
728 			if (*curr == '\0')
729 				goto parse_fail;
730 		}
731 
732 		if (attr_name[0] != '\0' && found_type) {
733 			/*
734 			 * We get here after we have processed the "<prop>="
735 			 * pattern. The pattern we are now interested in is
736 			 * "<val>;".
737 			 */
738 			if (c == '=')
739 				goto parse_fail;
740 
741 			if (strcmp(attr_name, "linkid") == 0) {
742 				(void) read_int64(curr, &attr_buf);
743 				linkp->ll_linkid =
744 				    (datalink_class_t)*(int64_t *)attr_buf;
745 			} else if (strcmp(attr_name, "name") == 0) {
746 				(void) read_str(curr, &attr_buf);
747 				(void) snprintf(linkp->ll_link,
748 				    MAXLINKNAMELEN, "%s", attr_buf);
749 			} else if (strcmp(attr_name, "class") == 0) {
750 				(void) read_int64(curr, &attr_buf);
751 				linkp->ll_class =
752 				    (datalink_class_t)*(int64_t *)attr_buf;
753 			} else if (strcmp(attr_name, "media") == 0) {
754 				(void) read_int64(curr, &attr_buf);
755 				linkp->ll_media =
756 				    (uint32_t)*(int64_t *)attr_buf;
757 			} else {
758 				attr_buf_len = translators[type].read_func(curr,
759 				    &attr_buf);
760 				err = linkattr_set(&(linkp->ll_head), attr_name,
761 				    attr_buf, attr_buf_len, type);
762 			}
763 
764 			free(attr_buf);
765 			attr_name[0] = '\0';
766 			found_type = B_FALSE;
767 		} else if (attr_name[0] != '\0') {
768 			/*
769 			 * Non-zero length attr_name and found_type of false
770 			 * indicates that we have not found the type for this
771 			 * attribute.  The pattern now is "<type>,<val>;", we
772 			 * want the <type> part of the pattern.
773 			 */
774 			for (type = 0; type < ntranslators; type++) {
775 				if (strcmp(curr,
776 				    translators[type].type_name) == 0) {
777 					found_type = B_TRUE;
778 					break;
779 				}
780 			}
781 
782 			if (!found_type)
783 				goto parse_fail;
784 		} else {
785 			/*
786 			 * A zero length attr_name indicates we are looking
787 			 * at the beginning of a link attribute.
788 			 */
789 			if (c != '=')
790 				goto parse_fail;
791 
792 			(void) snprintf(attr_name, MAXLINKATTRLEN, "%s", curr);
793 		}
794 		curr = buf + i + 1;
795 	}
796 
797 	return (err);
798 
799 parse_fail:
800 	return (-1);
801 }
802 
803 static boolean_t
804 process_link_line(char *buf, dlmgmt_link_t *linkp)
805 {
806 	int	i, len, llen;
807 	char	*str, *lasts;
808 	char	tmpbuf[MAXLINELEN];
809 
810 	bzero(linkp, sizeof (*linkp));
811 	linkp->ll_linkid = DATALINK_INVALID_LINKID;
812 
813 	/*
814 	 * Use a copy of buf for parsing so that we can do whatever we want.
815 	 */
816 	(void) strlcpy(tmpbuf, buf, MAXLINELEN);
817 
818 	/*
819 	 * Skip leading spaces, blank lines, and comments.
820 	 */
821 	len = strlen(tmpbuf);
822 	for (i = 0; i < len; i++) {
823 		if (!isspace(tmpbuf[i]))
824 			break;
825 	}
826 	if (i == len || tmpbuf[i] == '#')
827 		return (B_TRUE);
828 
829 	str = tmpbuf + i;
830 	/*
831 	 * Find the link name and assign it to the link structure.
832 	 */
833 	if (strtok_r(str, " \n\t", &lasts) == NULL)
834 		goto fail;
835 
836 	llen = strlen(str);
837 	/*
838 	 * Note that a previous version of the persistent datalink.conf file
839 	 * stored the linkid as the first field.  In that case, the name will
840 	 * be obtained through parse_linkprops from a property with the format
841 	 * "name=<linkname>".  If we encounter such a format, we set
842 	 * rewrite_needed so that dlmgmt_db_init() can rewrite the file with
843 	 * the new format after it's done reading in the data.
844 	 */
845 	if (isdigit(str[0])) {
846 		linkp->ll_linkid = atoi(str);
847 		rewrite_needed = B_TRUE;
848 	} else {
849 		if (strlcpy(linkp->ll_link, str, sizeof (linkp->ll_link)) >=
850 		    sizeof (linkp->ll_link))
851 			goto fail;
852 	}
853 
854 	str += llen + 1;
855 	if (str >= tmpbuf + len)
856 		goto fail;
857 
858 	/*
859 	 * Now find the list of link properties.
860 	 */
861 	if ((str = strtok_r(str, " \n\t", &lasts)) == NULL)
862 		goto fail;
863 
864 	if (parse_linkprops(str, linkp) < 0)
865 		goto fail;
866 
867 	return (B_TRUE);
868 
869 fail:
870 	/*
871 	 * Delete corrupted line.
872 	 */
873 	buf[0] = '\0';
874 	return (B_FALSE);
875 }
876 
877 /*
878  * Find any properties in linkp that refer to "old", and rename to "new".
879  * Return B_TRUE if any renaming occurred.
880  */
881 static int
882 dlmgmt_attr_rename(dlmgmt_link_t *linkp, const char *old, const char *new,
883     boolean_t *renamed)
884 {
885 	dlmgmt_linkattr_t	*attrp;
886 	char			*newval = NULL, *pname;
887 	char			valcp[MAXLINKATTRVALLEN];
888 	size_t			newsize;
889 
890 	*renamed = B_FALSE;
891 
892 	if ((attrp = linkattr_find(linkp->ll_head, "linkover")) != NULL ||
893 	    (attrp = linkattr_find(linkp->ll_head, "simnetpeer")) != NULL) {
894 		if (strcmp(old, (char *)attrp->lp_val) == 0) {
895 			newsize = strlen(new) + 1;
896 			if ((newval = malloc(newsize)) == NULL)
897 				return (errno);
898 			(void) strcpy(newval, new);
899 			free(attrp->lp_val);
900 			attrp->lp_val = newval;
901 			attrp->lp_sz = newsize;
902 			*renamed = B_TRUE;
903 		}
904 		return (0);
905 	}
906 
907 	if ((attrp = linkattr_find(linkp->ll_head, "portnames")) == NULL)
908 		return (0);
909 
910 	/* <linkname>:[<linkname>:]... */
911 	if ((newval = calloc(MAXLINKATTRVALLEN, sizeof (char))) == NULL)
912 		return (errno);
913 
914 	bcopy(attrp->lp_val, valcp, sizeof (valcp));
915 	pname = strtok(valcp, ":");
916 	while (pname != NULL) {
917 		if (strcmp(pname, old) == 0) {
918 			(void) strcat(newval, new);
919 			*renamed = B_TRUE;
920 		} else {
921 			(void) strcat(newval, pname);
922 		}
923 		(void) strcat(newval, ":");
924 		pname = strtok(NULL, ":");
925 	}
926 	if (*renamed) {
927 		free(attrp->lp_val);
928 		attrp->lp_val = newval;
929 		attrp->lp_sz = strlen(newval) + 1;
930 	} else {
931 		free(newval);
932 	}
933 	return (0);
934 }
935 
936 static int
937 process_db_write(dlmgmt_db_req_t *req, FILE *fp, FILE *nfp)
938 {
939 	boolean_t		done = B_FALSE;
940 	int			err = 0;
941 	dlmgmt_link_t		link_in_file, *linkp = NULL, *dblinkp;
942 	boolean_t		persist = (req->ls_flags == DLMGMT_PERSIST);
943 	boolean_t		writeall, rename, attr_renamed;
944 	char			buf[MAXLINELEN];
945 
946 	writeall = (req->ls_linkid == DATALINK_ALL_LINKID);
947 
948 	if (req->ls_op == DLMGMT_DB_OP_WRITE && !writeall) {
949 		/*
950 		 * find the link in the avl tree with the given linkid.
951 		 */
952 		linkp = link_by_id(req->ls_linkid, req->ls_zoneid);
953 		if (linkp == NULL || (linkp->ll_flags & req->ls_flags) == 0) {
954 			/*
955 			 * This link has already been changed. This could
956 			 * happen if the request is pending because of
957 			 * read-only file-system. If so, we are done.
958 			 */
959 			return (0);
960 		}
961 		/*
962 		 * In the case of a rename, linkp's name has been updated to
963 		 * the new name, and req->ls_link is the old link name.
964 		 */
965 		rename = (strcmp(req->ls_link, linkp->ll_link) != 0);
966 	}
967 
968 	/*
969 	 * fp can be NULL if the file didn't initially exist and we're
970 	 * creating it as part of this write operation.
971 	 */
972 	if (fp == NULL)
973 		goto write;
974 
975 	while (err == 0 && fgets(buf, sizeof (buf), fp) != NULL &&
976 	    process_link_line(buf, &link_in_file)) {
977 		if (link_in_file.ll_link[0] == '\0' || done) {
978 			/*
979 			 * this is a comment line or we are done updating the
980 			 * line for the specified link, write the rest of
981 			 * lines out.
982 			 */
983 			if (fputs(buf, nfp) == EOF)
984 				err = errno;
985 			continue;
986 		}
987 
988 		switch (req->ls_op) {
989 		case DLMGMT_DB_OP_WRITE:
990 			/*
991 			 * For write operations, we generate a new output line
992 			 * if we're either writing all links (writeall) or if
993 			 * the name of the link in the file matches the one
994 			 * we're looking for.  Otherwise, we write out the
995 			 * buffer as-is.
996 			 *
997 			 * If we're doing a rename operation, ensure that any
998 			 * references to the link being renamed in link
999 			 * properties are also updated before we write
1000 			 * anything.
1001 			 */
1002 			if (writeall) {
1003 				linkp = link_by_name(link_in_file.ll_link,
1004 				    req->ls_zoneid);
1005 			}
1006 			if (writeall || strcmp(req->ls_link,
1007 			    link_in_file.ll_link) == 0) {
1008 				generate_link_line(linkp, persist, buf);
1009 				if (!writeall && !rename)
1010 					done = B_TRUE;
1011 			} else if (rename && persist) {
1012 				dblinkp = link_by_name(link_in_file.ll_link,
1013 				    req->ls_zoneid);
1014 				err = dlmgmt_attr_rename(dblinkp, req->ls_link,
1015 				    linkp->ll_link, &attr_renamed);
1016 				if (err != 0)
1017 					break;
1018 				if (attr_renamed) {
1019 					generate_link_line(dblinkp, persist,
1020 					    buf);
1021 				}
1022 			}
1023 			if (fputs(buf, nfp) == EOF)
1024 				err = errno;
1025 			break;
1026 		case DLMGMT_DB_OP_DELETE:
1027 			/*
1028 			 * Delete is simple.  If buf does not represent the
1029 			 * link we're deleting, write it out.
1030 			 */
1031 			if (strcmp(req->ls_link, link_in_file.ll_link) != 0) {
1032 				if (fputs(buf, nfp) == EOF)
1033 					err = errno;
1034 			} else {
1035 				done = B_TRUE;
1036 			}
1037 			break;
1038 		case DLMGMT_DB_OP_READ:
1039 		default:
1040 			err = EINVAL;
1041 			break;
1042 		}
1043 	}
1044 
1045 write:
1046 	/*
1047 	 * If we get to the end of the file and have not seen what linkid
1048 	 * points to, write it out then.
1049 	 */
1050 	if (req->ls_op == DLMGMT_DB_OP_WRITE && !writeall && !rename && !done) {
1051 		generate_link_line(linkp, persist, buf);
1052 		done = B_TRUE;
1053 		if (fputs(buf, nfp) == EOF)
1054 			err = errno;
1055 	}
1056 
1057 	return (err);
1058 }
1059 
1060 static int
1061 process_db_read(dlmgmt_db_req_t *req, FILE *fp)
1062 {
1063 	avl_index_t	name_where, id_where;
1064 	dlmgmt_link_t	link_in_file, *newlink, *link_in_db;
1065 	char		buf[MAXLINELEN];
1066 	int		err = 0;
1067 
1068 	/*
1069 	 * This loop processes each line of the configuration file.
1070 	 */
1071 	while (fgets(buf, MAXLINELEN, fp) != NULL) {
1072 		if (!process_link_line(buf, &link_in_file)) {
1073 			err = EINVAL;
1074 			break;
1075 		}
1076 
1077 		/*
1078 		 * Skip the comment line.
1079 		 */
1080 		if (link_in_file.ll_link[0] == '\0')
1081 			continue;
1082 
1083 		if ((req->ls_flags & DLMGMT_ACTIVE) &&
1084 		    link_in_file.ll_linkid == DATALINK_INVALID_LINKID)
1085 			continue;
1086 
1087 		link_in_file.ll_zoneid = req->ls_zoneid;
1088 		link_in_db = avl_find(&dlmgmt_name_avl, &link_in_file,
1089 		    &name_where);
1090 		if (link_in_db != NULL) {
1091 			/*
1092 			 * If the link in the database already has the flag
1093 			 * for this request set, then the entry is a
1094 			 * duplicate.  If it's not a duplicate, then simply
1095 			 * turn on the appropriate flag on the existing link.
1096 			 */
1097 			if (link_in_db->ll_flags & req->ls_flags) {
1098 				dlmgmt_log(LOG_WARNING, "Duplicate links "
1099 				    "in the repository: %s",
1100 				    link_in_file.ll_link);
1101 			} else {
1102 				if (req->ls_flags & DLMGMT_PERSIST) {
1103 					/*
1104 					 * Save the newly read properties into
1105 					 * the existing link.
1106 					 */
1107 					assert(link_in_db->ll_head == NULL);
1108 					link_in_db->ll_head =
1109 					    link_in_file.ll_head;
1110 				}
1111 				link_in_db->ll_flags |= req->ls_flags;
1112 			}
1113 		} else {
1114 			/*
1115 			 * This is a new link.  Allocate a new dlmgmt_link_t
1116 			 * and add it to the trees.
1117 			 */
1118 			newlink = calloc(1, sizeof (*newlink));
1119 			if (newlink == NULL) {
1120 				dlmgmt_log(LOG_WARNING, "Unable to allocate "
1121 				    "memory to create new link %s",
1122 				    link_in_file.ll_link);
1123 				continue;
1124 			}
1125 			bcopy(&link_in_file, newlink, sizeof (*newlink));
1126 
1127 			if (newlink->ll_linkid == DATALINK_INVALID_LINKID)
1128 				newlink->ll_linkid = dlmgmt_nextlinkid;
1129 			if (avl_find(&dlmgmt_id_avl, newlink, &id_where) !=
1130 			    NULL) {
1131 				link_destroy(newlink);
1132 				continue;
1133 			}
1134 			if ((req->ls_flags & DLMGMT_ACTIVE) &&
1135 			    link_activate(newlink) != 0) {
1136 				dlmgmt_log(LOG_WARNING, "Unable to activate %s",
1137 				    newlink->ll_link);
1138 				link_destroy(newlink);
1139 				continue;
1140 			}
1141 			avl_insert(&dlmgmt_name_avl, newlink, name_where);
1142 			avl_insert(&dlmgmt_id_avl, newlink, id_where);
1143 			dlmgmt_advance(newlink);
1144 			newlink->ll_flags |= req->ls_flags;
1145 		}
1146 	}
1147 
1148 	return (err);
1149 }
1150 
1151 /*
1152  * Generate an entry in the link database.
1153  * Each entry has this format:
1154  * <link name>	<prop0>=<type>,<val>;...;<propn>=<type>,<val>;
1155  */
1156 static void
1157 generate_link_line(dlmgmt_link_t *linkp, boolean_t persist, char *buf)
1158 {
1159 	char			tmpbuf[MAXLINELEN];
1160 	char			*ptr = tmpbuf;
1161 	char			*lim = tmpbuf + MAXLINELEN;
1162 	dlmgmt_linkattr_t	*cur_p = NULL;
1163 	uint64_t		u64;
1164 
1165 	ptr += snprintf(ptr, BUFLEN(lim, ptr), "%s\t", linkp->ll_link);
1166 	if (!persist) {
1167 		/*
1168 		 * We store the linkid in the active database so that dlmgmtd
1169 		 * can recover in the event that it is restarted.
1170 		 */
1171 		u64 = linkp->ll_linkid;
1172 		ptr += write_uint64(ptr, BUFLEN(lim, ptr), "linkid", &u64);
1173 	}
1174 	u64 = linkp->ll_class;
1175 	ptr += write_uint64(ptr, BUFLEN(lim, ptr), "class", &u64);
1176 	u64 = linkp->ll_media;
1177 	ptr += write_uint64(ptr, BUFLEN(lim, ptr), "media", &u64);
1178 
1179 	/*
1180 	 * The daemon does not keep any active link attribute. Only store the
1181 	 * attributes if this request is for persistent configuration,
1182 	 */
1183 	if (persist) {
1184 		for (cur_p = linkp->ll_head; cur_p != NULL;
1185 		    cur_p = cur_p->lp_next) {
1186 			ptr += translators[cur_p->lp_type].write_func(ptr,
1187 			    BUFLEN(lim, ptr), cur_p->lp_name, cur_p->lp_val);
1188 		}
1189 	}
1190 
1191 	if (ptr <= lim)
1192 		(void) snprintf(buf, MAXLINELEN, "%s\n", tmpbuf);
1193 }
1194 
1195 int
1196 dlmgmt_delete_db_entry(dlmgmt_link_t *linkp, uint32_t flags)
1197 {
1198 	return (dlmgmt_db_update(DLMGMT_DB_OP_DELETE, linkp->ll_link, linkp,
1199 	    flags));
1200 }
1201 
1202 int
1203 dlmgmt_write_db_entry(const char *entryname, dlmgmt_link_t *linkp,
1204     uint32_t flags)
1205 {
1206 	int err;
1207 
1208 	if (flags & DLMGMT_PERSIST) {
1209 		if ((err = dlmgmt_db_update(DLMGMT_DB_OP_WRITE, entryname,
1210 		    linkp, DLMGMT_PERSIST)) != 0) {
1211 			return (err);
1212 		}
1213 	}
1214 
1215 	if (flags & DLMGMT_ACTIVE) {
1216 		if (((err = dlmgmt_db_update(DLMGMT_DB_OP_WRITE, entryname,
1217 		    linkp, DLMGMT_ACTIVE)) != 0) && (flags & DLMGMT_PERSIST)) {
1218 			(void) dlmgmt_db_update(DLMGMT_DB_OP_DELETE, entryname,
1219 			    linkp, DLMGMT_PERSIST);
1220 			return (err);
1221 		}
1222 	}
1223 
1224 	return (0);
1225 }
1226 
1227 /*
1228  * Upgrade properties that have link IDs as values to link names.  Because '.'
1229  * is a valid linkname character, the port separater for link aggregations
1230  * must be changed to ':'.
1231  */
1232 static void
1233 linkattr_upgrade(dlmgmt_linkattr_t *attrp)
1234 {
1235 	datalink_id_t	linkid;
1236 	char		*portidstr;
1237 	char		portname[MAXLINKNAMELEN + 1];
1238 	dlmgmt_link_t	*linkp;
1239 	char		*new_attr_val;
1240 	size_t		new_attr_sz;
1241 	boolean_t	upgraded = B_FALSE;
1242 
1243 	if (strcmp(attrp->lp_name, "linkover") == 0 ||
1244 	    strcmp(attrp->lp_name, "simnetpeer") == 0) {
1245 		if (attrp->lp_type == DLADM_TYPE_UINT64) {
1246 			linkid = (datalink_id_t)*(uint64_t *)attrp->lp_val;
1247 			if ((linkp = link_by_id(linkid, GLOBAL_ZONEID)) == NULL)
1248 				return;
1249 			new_attr_sz = strlen(linkp->ll_link) + 1;
1250 			if ((new_attr_val = malloc(new_attr_sz)) == NULL)
1251 				return;
1252 			(void) strcpy(new_attr_val, linkp->ll_link);
1253 			upgraded = B_TRUE;
1254 		}
1255 	} else if (strcmp(attrp->lp_name, "portnames") == 0) {
1256 		/*
1257 		 * The old format for "portnames" was
1258 		 * "<linkid>.[<linkid>.]...".  The new format is
1259 		 * "<linkname>:[<linkname>:]...".
1260 		 */
1261 		if (!isdigit(((char *)attrp->lp_val)[0]))
1262 			return;
1263 		new_attr_val = calloc(MAXLINKATTRVALLEN, sizeof (char));
1264 		if (new_attr_val == NULL)
1265 			return;
1266 		portidstr = (char *)attrp->lp_val;
1267 		while (*portidstr != '\0') {
1268 			errno = 0;
1269 			linkid = strtol(portidstr, &portidstr, 10);
1270 			if (linkid == 0 || *portidstr != '.' ||
1271 			    (linkp = link_by_id(linkid, GLOBAL_ZONEID)) ==
1272 			    NULL) {
1273 				free(new_attr_val);
1274 				return;
1275 			}
1276 			(void) snprintf(portname, sizeof (portname), "%s:",
1277 			    linkp->ll_link);
1278 			if (strlcat(new_attr_val, portname,
1279 			    MAXLINKATTRVALLEN) >= MAXLINKATTRVALLEN) {
1280 				free(new_attr_val);
1281 				return;
1282 			}
1283 			/* skip the '.' delimiter */
1284 			portidstr++;
1285 		}
1286 		new_attr_sz = strlen(new_attr_val) + 1;
1287 		upgraded = B_TRUE;
1288 	}
1289 
1290 	if (upgraded) {
1291 		attrp->lp_type = DLADM_TYPE_STR;
1292 		attrp->lp_sz = new_attr_sz;
1293 		free(attrp->lp_val);
1294 		attrp->lp_val = new_attr_val;
1295 	}
1296 }
1297 
1298 static void
1299 dlmgmt_db_upgrade(dlmgmt_link_t *linkp)
1300 {
1301 	dlmgmt_linkattr_t *attrp;
1302 
1303 	for (attrp = linkp->ll_head; attrp != NULL; attrp = attrp->lp_next)
1304 		linkattr_upgrade(attrp);
1305 }
1306 
1307 static void
1308 dlmgmt_db_phys_activate(dlmgmt_link_t *linkp)
1309 {
1310 	linkp->ll_flags |= DLMGMT_ACTIVE;
1311 	(void) dlmgmt_write_db_entry(linkp->ll_link, linkp, DLMGMT_ACTIVE);
1312 }
1313 
1314 static void
1315 dlmgmt_db_walk(zoneid_t zoneid, datalink_class_t class, db_walk_func_t *func)
1316 {
1317 	dlmgmt_link_t *linkp;
1318 
1319 	for (linkp = avl_first(&dlmgmt_id_avl); linkp != NULL;
1320 	    linkp = AVL_NEXT(&dlmgmt_id_avl, linkp)) {
1321 		if (linkp->ll_zoneid == zoneid && (linkp->ll_class & class))
1322 			func(linkp);
1323 	}
1324 }
1325 
1326 /*
1327  * Initialize the datalink <link name, linkid> mapping and the link's
1328  * attributes list based on the configuration file /etc/dladm/datalink.conf
1329  * and the active configuration cache file
1330  * /etc/svc/volatile/dladm/datalink-management:default.cache.
1331  */
1332 int
1333 dlmgmt_db_init(zoneid_t zoneid)
1334 {
1335 	dlmgmt_db_req_t	*req;
1336 	int		err;
1337 	boolean_t	boot = B_FALSE;
1338 
1339 	if ((req = dlmgmt_db_req_alloc(DLMGMT_DB_OP_READ, NULL,
1340 	    DATALINK_INVALID_LINKID, zoneid, DLMGMT_ACTIVE, &err)) == NULL)
1341 		return (err);
1342 
1343 	if ((err = dlmgmt_process_db_req(req)) != 0) {
1344 		/*
1345 		 * If we get back ENOENT, that means that the active
1346 		 * configuration file doesn't exist yet, and is not an error.
1347 		 * We'll create it down below after we've loaded the
1348 		 * persistent configuration.
1349 		 */
1350 		if (err != ENOENT)
1351 			goto done;
1352 		boot = B_TRUE;
1353 	}
1354 
1355 	req->ls_flags = DLMGMT_PERSIST;
1356 	err = dlmgmt_process_db_req(req);
1357 	if (err != 0 && err != ENOENT)
1358 		goto done;
1359 	err = 0;
1360 	if (rewrite_needed) {
1361 		/*
1362 		 * First update links in memory, then dump the entire db to
1363 		 * disk.
1364 		 */
1365 		dlmgmt_db_walk(zoneid, DATALINK_CLASS_ALL, dlmgmt_db_upgrade);
1366 		req->ls_op = DLMGMT_DB_OP_WRITE;
1367 		req->ls_linkid = DATALINK_ALL_LINKID;
1368 		if ((err = dlmgmt_process_db_req(req)) != 0 &&
1369 		    err != EINPROGRESS)
1370 			goto done;
1371 	}
1372 	if (boot) {
1373 		dlmgmt_db_walk(zoneid, DATALINK_CLASS_PHYS,
1374 		    dlmgmt_db_phys_activate);
1375 	}
1376 
1377 done:
1378 	if (err == EINPROGRESS)
1379 		err = 0;
1380 	else
1381 		free(req);
1382 	return (err);
1383 }
1384 
1385 /*
1386  * Remove all links in the given zoneid.
1387  */
1388 void
1389 dlmgmt_db_fini(zoneid_t zoneid)
1390 {
1391 	dlmgmt_link_t *linkp = avl_first(&dlmgmt_name_avl), *next_linkp;
1392 
1393 	while (linkp != NULL) {
1394 		next_linkp = AVL_NEXT(&dlmgmt_name_avl, linkp);
1395 		if (linkp->ll_zoneid == zoneid) {
1396 			(void) dlmgmt_destroy_common(linkp,
1397 			    DLMGMT_ACTIVE | DLMGMT_PERSIST);
1398 		}
1399 		linkp = next_linkp;
1400 	}
1401 }
1402