1/******************************************************************************
2 *
3 * Module Name: exnames - interpreter/scanner name load/execute
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2023, 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 MERCHANTABILITY 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.h"
45#include "accommon.h"
46#include "acinterp.h"
47#include "amlcode.h"
48
49#define _COMPONENT          ACPI_EXECUTER
50        ACPI_MODULE_NAME    ("exnames")
51
52/* Local prototypes */
53
54static char *
55AcpiExAllocateNameString (
56    UINT32                  PrefixCount,
57    UINT32                  NumNameSegs);
58
59static ACPI_STATUS
60AcpiExNameSegment (
61    UINT8                   **InAmlAddress,
62    char                    *NameString);
63
64
65/*******************************************************************************
66 *
67 * FUNCTION:    AcpiExAllocateNameString
68 *
69 * PARAMETERS:  PrefixCount         - Count of parent levels. Special cases:
70 *                                    (-1)==root,  0==none
71 *              NumNameSegs         - count of 4-character name segments
72 *
73 * RETURN:      A pointer to the allocated string segment. This segment must
74 *              be deleted by the caller.
75 *
76 * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
77 *              string is long enough, and set up prefix if any.
78 *
79 ******************************************************************************/
80
81static char *
82AcpiExAllocateNameString (
83    UINT32                  PrefixCount,
84    UINT32                  NumNameSegs)
85{
86    char                    *TempPtr;
87    char                    *NameString;
88    UINT32                   SizeNeeded;
89
90    ACPI_FUNCTION_TRACE (ExAllocateNameString);
91
92
93    /*
94     * Allow room for all \ and ^ prefixes, all segments and a MultiNamePrefix.
95     * Also, one byte for the null terminator.
96     * This may actually be somewhat longer than needed.
97     */
98    if (PrefixCount == ACPI_UINT32_MAX)
99    {
100        /* Special case for root */
101
102        SizeNeeded = 1 + (ACPI_NAMESEG_SIZE * NumNameSegs) + 2 + 1;
103    }
104    else
105    {
106        SizeNeeded = PrefixCount + (ACPI_NAMESEG_SIZE * NumNameSegs) + 2 + 1;
107    }
108
109    /*
110     * Allocate a buffer for the name.
111     * This buffer must be deleted by the caller!
112     */
113    NameString = ACPI_ALLOCATE (SizeNeeded);
114    if (!NameString)
115    {
116        ACPI_ERROR ((AE_INFO,
117            "Could not allocate size %u", SizeNeeded));
118        return_PTR (NULL);
119    }
120
121    TempPtr = NameString;
122
123    /* Set up Root or Parent prefixes if needed */
124
125    if (PrefixCount == ACPI_UINT32_MAX)
126    {
127        *TempPtr++ = AML_ROOT_PREFIX;
128    }
129    else
130    {
131        while (PrefixCount--)
132        {
133            *TempPtr++ = AML_PARENT_PREFIX;
134        }
135    }
136
137
138    /* Set up Dual or Multi prefixes if needed */
139
140    if (NumNameSegs > 2)
141    {
142        /* Set up multi prefixes   */
143
144        *TempPtr++ = AML_MULTI_NAME_PREFIX;
145        *TempPtr++ = (char) NumNameSegs;
146    }
147    else if (2 == NumNameSegs)
148    {
149        /* Set up dual prefixes */
150
151        *TempPtr++ = AML_DUAL_NAME_PREFIX;
152    }
153
154    /*
155     * Terminate string following prefixes. AcpiExNameSegment() will
156     * append the segment(s)
157     */
158    *TempPtr = 0;
159
160    return_PTR (NameString);
161}
162
163
164/*******************************************************************************
165 *
166 * FUNCTION:    AcpiExNameSegment
167 *
168 * PARAMETERS:  InAmlAddress    - Pointer to the name in the AML code
169 *              NameString      - Where to return the name. The name is appended
170 *                                to any existing string to form a namepath
171 *
172 * RETURN:      Status
173 *
174 * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
175 *
176 ******************************************************************************/
177
178static ACPI_STATUS
179AcpiExNameSegment (
180    UINT8                   **InAmlAddress,
181    char                    *NameString)
182{
183    char                    *AmlAddress = (void *) *InAmlAddress;
184    ACPI_STATUS             Status = AE_OK;
185    UINT32                  Index;
186    char                    CharBuf[5];
187
188
189    ACPI_FUNCTION_TRACE (ExNameSegment);
190
191
192    /*
193     * If first character is a digit, then we know that we aren't looking
194     * at a valid name segment
195     */
196    CharBuf[0] = *AmlAddress;
197
198    if ('0' <= CharBuf[0] && CharBuf[0] <= '9')
199    {
200        ACPI_ERROR ((AE_INFO, "Invalid leading digit: %c", CharBuf[0]));
201        return_ACPI_STATUS (AE_CTRL_PENDING);
202    }
203
204    for (Index = 0;
205        (Index < ACPI_NAMESEG_SIZE) && (AcpiUtValidNameChar (*AmlAddress, 0));
206        Index++)
207    {
208        CharBuf[Index] = *AmlAddress++;
209    }
210
211
212    /* Valid name segment  */
213
214    if (Index == 4)
215    {
216        /* Found 4 valid characters */
217
218        CharBuf[4] = '\0';
219
220        if (NameString)
221        {
222            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
223                "Appending NameSeg %s\n", CharBuf));
224            strcat (NameString, CharBuf);
225        }
226        else
227        {
228            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
229                "No Name string - %s\n", CharBuf));
230        }
231    }
232    else if (Index == 0)
233    {
234        /*
235         * First character was not a valid name character,
236         * so we are looking at something other than a name.
237         */
238        ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
239            "Leading character is not alpha: %02Xh (not a name)\n",
240            CharBuf[0]));
241        Status = AE_CTRL_PENDING;
242    }
243    else
244    {
245        /*
246         * Segment started with one or more valid characters, but fewer than
247         * the required 4
248         */
249        Status = AE_AML_BAD_NAME;
250        ACPI_ERROR ((AE_INFO,
251            "Bad character 0x%02x in name, at %p",
252            *AmlAddress, AmlAddress));
253    }
254
255    *InAmlAddress = ACPI_CAST_PTR (UINT8, AmlAddress);
256    return_ACPI_STATUS (Status);
257}
258
259
260/*******************************************************************************
261 *
262 * FUNCTION:    AcpiExGetNameString
263 *
264 * PARAMETERS:  DataType            - Object type to be associated with this
265 *                                    name
266 *              InAmlAddress        - Pointer to the namestring in the AML code
267 *              OutNameString       - Where the namestring is returned
268 *              OutNameLength       - Length of the returned string
269 *
270 * RETURN:      Status, namestring and length
271 *
272 * DESCRIPTION: Extract a full namepath from the AML byte stream,
273 *              including any prefixes.
274 *
275 ******************************************************************************/
276
277ACPI_STATUS
278AcpiExGetNameString (
279    ACPI_OBJECT_TYPE        DataType,
280    UINT8                   *InAmlAddress,
281    char                    **OutNameString,
282    UINT32                  *OutNameLength)
283{
284    ACPI_STATUS             Status = AE_OK;
285    UINT8                   *AmlAddress = InAmlAddress;
286    char                    *NameString = NULL;
287    UINT32                  NumSegments;
288    UINT32                  PrefixCount = 0;
289    BOOLEAN                 HasPrefix = FALSE;
290
291
292    ACPI_FUNCTION_TRACE_PTR (ExGetNameString, AmlAddress);
293
294
295    if (ACPI_TYPE_LOCAL_REGION_FIELD == DataType   ||
296        ACPI_TYPE_LOCAL_BANK_FIELD == DataType     ||
297        ACPI_TYPE_LOCAL_INDEX_FIELD == DataType)
298    {
299        /* Disallow prefixes for types associated with FieldUnit names */
300
301        NameString = AcpiExAllocateNameString (0, 1);
302        if (!NameString)
303        {
304            Status = AE_NO_MEMORY;
305        }
306        else
307        {
308            Status = AcpiExNameSegment (&AmlAddress, NameString);
309        }
310    }
311    else
312    {
313        /*
314         * DataType is not a field name.
315         * Examine first character of name for root or parent prefix operators
316         */
317        switch (*AmlAddress)
318        {
319        case AML_ROOT_PREFIX:
320
321            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "RootPrefix(\\) at %p\n",
322                AmlAddress));
323
324            /*
325             * Remember that we have a RootPrefix --
326             * see comment in AcpiExAllocateNameString()
327             */
328            AmlAddress++;
329            PrefixCount = ACPI_UINT32_MAX;
330            HasPrefix = TRUE;
331            break;
332
333        case AML_PARENT_PREFIX:
334
335            /* Increment past possibly multiple parent prefixes */
336
337            do
338            {
339                ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "ParentPrefix (^) at %p\n",
340                    AmlAddress));
341
342                AmlAddress++;
343                PrefixCount++;
344
345            } while (*AmlAddress == AML_PARENT_PREFIX);
346
347            HasPrefix = TRUE;
348            break;
349
350        default:
351
352            /* Not a prefix character */
353
354            break;
355        }
356
357        /* Examine first character of name for name segment prefix operator */
358
359        switch (*AmlAddress)
360        {
361        case AML_DUAL_NAME_PREFIX:
362
363            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "DualNamePrefix at %p\n",
364                AmlAddress));
365
366            AmlAddress++;
367            NameString = AcpiExAllocateNameString (PrefixCount, 2);
368            if (!NameString)
369            {
370                Status = AE_NO_MEMORY;
371                break;
372            }
373
374            /* Indicate that we processed a prefix */
375
376            HasPrefix = TRUE;
377
378            Status = AcpiExNameSegment (&AmlAddress, NameString);
379            if (ACPI_SUCCESS (Status))
380            {
381                Status = AcpiExNameSegment (&AmlAddress, NameString);
382            }
383            break;
384
385        case AML_MULTI_NAME_PREFIX:
386
387            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "MultiNamePrefix at %p\n",
388                AmlAddress));
389
390            /* Fetch count of segments remaining in name path */
391
392            AmlAddress++;
393            NumSegments = *AmlAddress;
394
395            NameString = AcpiExAllocateNameString (
396                PrefixCount, NumSegments);
397            if (!NameString)
398            {
399                Status = AE_NO_MEMORY;
400                break;
401            }
402
403            /* Indicate that we processed a prefix */
404
405            AmlAddress++;
406            HasPrefix = TRUE;
407
408            while (NumSegments &&
409                    (Status = AcpiExNameSegment (&AmlAddress, NameString)) ==
410                        AE_OK)
411            {
412                NumSegments--;
413            }
414
415            break;
416
417        case 0:
418
419            /* NullName valid as of 8-12-98 ASL/AML Grammar Update */
420
421            if (PrefixCount == ACPI_UINT32_MAX)
422            {
423                ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
424                    "NameSeg is \"\\\" followed by NULL\n"));
425            }
426
427            /* Consume the NULL byte */
428
429            AmlAddress++;
430            NameString = AcpiExAllocateNameString (PrefixCount, 0);
431            if (!NameString)
432            {
433                Status = AE_NO_MEMORY;
434                break;
435            }
436
437            break;
438
439        default:
440
441            /* Name segment string */
442
443            NameString = AcpiExAllocateNameString (PrefixCount, 1);
444            if (!NameString)
445            {
446                Status = AE_NO_MEMORY;
447                break;
448            }
449
450            Status = AcpiExNameSegment (&AmlAddress, NameString);
451            break;
452        }
453    }
454
455    if (AE_CTRL_PENDING == Status && HasPrefix)
456    {
457        /* Ran out of segments after processing a prefix */
458
459        ACPI_ERROR ((AE_INFO,
460            "Malformed Name at %p", NameString));
461        Status = AE_AML_BAD_NAME;
462    }
463
464    if (ACPI_FAILURE (Status))
465    {
466        if (NameString)
467        {
468            ACPI_FREE (NameString);
469        }
470        return_ACPI_STATUS (Status);
471    }
472
473    *OutNameString = NameString;
474    *OutNameLength = (UINT32) (AmlAddress - InAmlAddress);
475
476    return_ACPI_STATUS (Status);
477}
478