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 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#pragma ident	"%Z%%M%	%I%	%E% SMI"
27
28#include "libdevinfo.h"
29#include <strings.h>
30#include <sys/modctl.h>
31
32/*
33 *
34 * This file contains interfaces to translate <driver><instance><minorname>
35 * information into /devices and /dev paths.  It does this using interfaces to
36 * the kernel instance tree so that it can provide translations for devices
37 * which are no longer present. An example consumer of these interfaces is
38 * iostat(1M) - which shows, in its first iteration, activity since reboot.
39 * With persistant kstats, a device which was busy a long time ago can still
40 * have a decaying presence in iostat output, and that output, when '-n' is
41 * used, should show the public name.
42 */
43
44typedef	struct {
45	di_devlink_handle_t	i_devlink_hdl;
46} *idim_t;
47
48di_dim_t
49di_dim_init()
50{
51	idim_t		idim;
52
53	if ((idim = (idim_t)malloc(sizeof (*idim))) == NULL)
54		return (NULL);
55	idim->i_devlink_hdl = di_devlink_init(NULL, 0);
56	if (idim->i_devlink_hdl == NULL) {
57		free(idim);
58		return (NULL);
59	}
60	return ((di_dim_t)idim);
61}
62
63void
64di_dim_fini(di_dim_t dim)
65{
66	idim_t	idim = (idim_t)dim;
67
68	if (idim->i_devlink_hdl) {
69		(void) di_devlink_fini(&idim->i_devlink_hdl);
70	}
71	free(idim);
72}
73
74/*ARGSUSED*/
75char *
76di_dim_path_devices(di_dim_t dim, char *drv_name, int instance,
77    char *minor_name)
78{
79	major_t	major;
80	int	len;
81	int	mlen;
82	char	*devices;
83
84	/* convert drv_name to major_t */
85	if (modctl(MODGETMAJBIND, drv_name, strlen(drv_name) + 1, &major) < 0)
86		return (NULL);
87
88	/* find the length of the devices path given major,instance */
89	if (modctl(MODGETDEVFSPATH_MI_LEN, major, instance, &len) != 0)
90		return (NULL);
91
92	/*
93	 * MODGETDEVFSPATH_MI_LEN result includes '\0' termination, but we
94	 * may need to add space for ":<minor_name>"
95	 */
96	if (minor_name)
97		mlen = len + 1 + strlen(minor_name);
98	else
99		mlen = len;
100	if ((devices = (char *)malloc(mlen)) == NULL)
101		return (NULL);
102
103	if (modctl(MODGETDEVFSPATH_MI, major, instance, len, devices) != 0) {
104		free(devices);
105		return (NULL);
106	}
107
108	if (minor_name) {
109		/* add ':<minot_name>' to the end of /devices path */
110		(void) strcat(devices, ":");
111		(void) strcat(devices, minor_name);
112	}
113	return (devices);
114}
115
116/* di_dim_path_dev di_devlink callback */
117static int
118di_dim_path_dev_callback(di_devlink_t dl, void *arg)
119{
120	char		**devp = (char **)arg;
121	char		*devpath = (char *)di_devlink_path(dl);
122
123	if (devpath)
124		*devp = strdup(devpath);
125	return (DI_WALK_TERMINATE);
126}
127
128char *
129di_dim_path_dev(di_dim_t dim, char *drv_name, int instance, char *minor_name)
130{
131	idim_t	idim = (idim_t)dim;
132	char	*devices;
133	char	*dev = NULL;
134
135	/* we must have a minor_name to resolve to a public name */
136	if (minor_name == NULL)
137		return (NULL);
138
139	/* convert <driver><instance><minor_name> to /devices path */
140	devices = di_dim_path_devices(dim, drv_name, instance, minor_name);
141	if (devices == NULL)
142		return (NULL);
143
144	/* convert /devices path to /dev path */
145	(void) di_devlink_walk(idim->i_devlink_hdl, NULL,
146	    devices, DI_PRIMARY_LINK, (void *)&dev, di_dim_path_dev_callback);
147	free(devices);
148	return (dev);
149}
150