1/*******************************************************************************
2 *
3 * Module Name: nsnames - Name manipulation and search
4 *
5 ******************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2014, Intel Corp.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions, and the following disclaimer,
16 *    without modification.
17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18 *    substantially similar to the "NO WARRANTY" disclaimer below
19 *    ("Disclaimer") and any redistribution must be conditioned upon
20 *    including a substantially similar Disclaimer requirement for further
21 *    binary redistribution.
22 * 3. Neither the names of the above-listed copyright holders nor the names
23 *    of any contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * Alternatively, this software may be distributed under the terms of the
27 * GNU General Public License ("GPL") version 2 as published by the Free
28 * Software Foundation.
29 *
30 * NO WARRANTY
31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41 * POSSIBILITY OF SUCH DAMAGES.
42 */
43
44#include <acpi/acpi.h>
45#include "accommon.h"
46#include "amlcode.h"
47#include "acnamesp.h"
48
49#define _COMPONENT          ACPI_NAMESPACE
50ACPI_MODULE_NAME("nsnames")
51
52/*******************************************************************************
53 *
54 * FUNCTION:    acpi_ns_build_external_path
55 *
56 * PARAMETERS:  node            - NS node whose pathname is needed
57 *              size            - Size of the pathname
58 *              *name_buffer    - Where to return the pathname
59 *
60 * RETURN:      Status
61 *              Places the pathname into the name_buffer, in external format
62 *              (name segments separated by path separators)
63 *
64 * DESCRIPTION: Generate a full pathaname
65 *
66 ******************************************************************************/
67acpi_status
68acpi_ns_build_external_path(struct acpi_namespace_node *node,
69			    acpi_size size, char *name_buffer)
70{
71	acpi_size index;
72	struct acpi_namespace_node *parent_node;
73
74	ACPI_FUNCTION_ENTRY();
75
76	/* Special case for root */
77
78	index = size - 1;
79	if (index < ACPI_NAME_SIZE) {
80		name_buffer[0] = AML_ROOT_PREFIX;
81		name_buffer[1] = 0;
82		return (AE_OK);
83	}
84
85	/* Store terminator byte, then build name backwards */
86
87	parent_node = node;
88	name_buffer[index] = 0;
89
90	while ((index > ACPI_NAME_SIZE) && (parent_node != acpi_gbl_root_node)) {
91		index -= ACPI_NAME_SIZE;
92
93		/* Put the name into the buffer */
94
95		ACPI_MOVE_32_TO_32((name_buffer + index), &parent_node->name);
96		parent_node = parent_node->parent;
97
98		/* Prefix name with the path separator */
99
100		index--;
101		name_buffer[index] = ACPI_PATH_SEPARATOR;
102	}
103
104	/* Overwrite final separator with the root prefix character */
105
106	name_buffer[index] = AML_ROOT_PREFIX;
107
108	if (index != 0) {
109		ACPI_ERROR((AE_INFO,
110			    "Could not construct external pathname; index=%u, size=%u, Path=%s",
111			    (u32) index, (u32) size, &name_buffer[size]));
112
113		return (AE_BAD_PARAMETER);
114	}
115
116	return (AE_OK);
117}
118
119/*******************************************************************************
120 *
121 * FUNCTION:    acpi_ns_get_external_pathname
122 *
123 * PARAMETERS:  node            - Namespace node whose pathname is needed
124 *
125 * RETURN:      Pointer to storage containing the fully qualified name of
126 *              the node, In external format (name segments separated by path
127 *              separators.)
128 *
129 * DESCRIPTION: Used to obtain the full pathname to a namespace node, usually
130 *              for error and debug statements.
131 *
132 ******************************************************************************/
133
134char *acpi_ns_get_external_pathname(struct acpi_namespace_node *node)
135{
136	acpi_status status;
137	char *name_buffer;
138	acpi_size size;
139
140	ACPI_FUNCTION_TRACE_PTR(ns_get_external_pathname, node);
141
142	/* Calculate required buffer size based on depth below root */
143
144	size = acpi_ns_get_pathname_length(node);
145	if (!size) {
146		return_PTR(NULL);
147	}
148
149	/* Allocate a buffer to be returned to caller */
150
151	name_buffer = ACPI_ALLOCATE_ZEROED(size);
152	if (!name_buffer) {
153		ACPI_ERROR((AE_INFO, "Could not allocate %u bytes", (u32)size));
154		return_PTR(NULL);
155	}
156
157	/* Build the path in the allocated buffer */
158
159	status = acpi_ns_build_external_path(node, size, name_buffer);
160	if (ACPI_FAILURE(status)) {
161		ACPI_FREE(name_buffer);
162		return_PTR(NULL);
163	}
164
165	return_PTR(name_buffer);
166}
167
168/*******************************************************************************
169 *
170 * FUNCTION:    acpi_ns_get_pathname_length
171 *
172 * PARAMETERS:  node        - Namespace node
173 *
174 * RETURN:      Length of path, including prefix
175 *
176 * DESCRIPTION: Get the length of the pathname string for this node
177 *
178 ******************************************************************************/
179
180acpi_size acpi_ns_get_pathname_length(struct acpi_namespace_node *node)
181{
182	acpi_size size;
183	struct acpi_namespace_node *next_node;
184
185	ACPI_FUNCTION_ENTRY();
186
187	/*
188	 * Compute length of pathname as 5 * number of name segments.
189	 * Go back up the parent tree to the root
190	 */
191	size = 0;
192	next_node = node;
193
194	while (next_node && (next_node != acpi_gbl_root_node)) {
195		if (ACPI_GET_DESCRIPTOR_TYPE(next_node) != ACPI_DESC_TYPE_NAMED) {
196			ACPI_ERROR((AE_INFO,
197				    "Invalid Namespace Node (%p) while traversing namespace",
198				    next_node));
199			return (0);
200		}
201		size += ACPI_PATH_SEGMENT_LENGTH;
202		next_node = next_node->parent;
203	}
204
205	if (!size) {
206		size = 1;	/* Root node case */
207	}
208
209	return (size + 1);	/* +1 for null string terminator */
210}
211
212/*******************************************************************************
213 *
214 * FUNCTION:    acpi_ns_handle_to_pathname
215 *
216 * PARAMETERS:  target_handle           - Handle of named object whose name is
217 *                                        to be found
218 *              buffer                  - Where the pathname is returned
219 *
220 * RETURN:      Status, Buffer is filled with pathname if status is AE_OK
221 *
222 * DESCRIPTION: Build and return a full namespace pathname
223 *
224 ******************************************************************************/
225
226acpi_status
227acpi_ns_handle_to_pathname(acpi_handle target_handle,
228			   struct acpi_buffer * buffer)
229{
230	acpi_status status;
231	struct acpi_namespace_node *node;
232	acpi_size required_size;
233
234	ACPI_FUNCTION_TRACE_PTR(ns_handle_to_pathname, target_handle);
235
236	node = acpi_ns_validate_handle(target_handle);
237	if (!node) {
238		return_ACPI_STATUS(AE_BAD_PARAMETER);
239	}
240
241	/* Determine size required for the caller buffer */
242
243	required_size = acpi_ns_get_pathname_length(node);
244	if (!required_size) {
245		return_ACPI_STATUS(AE_BAD_PARAMETER);
246	}
247
248	/* Validate/Allocate/Clear caller buffer */
249
250	status = acpi_ut_initialize_buffer(buffer, required_size);
251	if (ACPI_FAILURE(status)) {
252		return_ACPI_STATUS(status);
253	}
254
255	/* Build the path in the caller buffer */
256
257	status =
258	    acpi_ns_build_external_path(node, required_size, buffer->pointer);
259	if (ACPI_FAILURE(status)) {
260		return_ACPI_STATUS(status);
261	}
262
263	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s [%X]\n",
264			  (char *)buffer->pointer, (u32) required_size));
265	return_ACPI_STATUS(AE_OK);
266}
267