// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: nsutils - Utilities for accessing ACPI namespace, accessing
 *                        parents and siblings and Scope manipulation
 *
 * Copyright (C) 2000 - 2020, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
#include "amlcode.h"

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nsutils")

/* Local prototypes */
#ifdef ACPI_OBSOLETE_FUNCTIONS
acpi_name acpi_ns_find_parent_name(struct acpi_namespace_node *node_to_search);
#endif

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_print_node_pathname
 *
 * PARAMETERS:  node            - Object
 *              message         - Prefix message
 *
 * DESCRIPTION: Print an object's full namespace pathname
 *              Manages allocation/freeing of a pathname buffer
 *
 ******************************************************************************/

void
acpi_ns_print_node_pathname(struct acpi_namespace_node *node,
                            const char *message)
{
        struct acpi_buffer buffer;
        acpi_status status;

        if (!node) {
                acpi_os_printf("[NULL NAME]");
                return;
        }

        /* Convert handle to full pathname and print it (with supplied message) */

        buffer.length = ACPI_ALLOCATE_LOCAL_BUFFER;

        status = acpi_ns_handle_to_pathname(node, &buffer, TRUE);
        if (ACPI_SUCCESS(status)) {
                if (message) {
                        acpi_os_printf("%s ", message);
                }

                acpi_os_printf("%s", (char *)buffer.pointer);
                ACPI_FREE(buffer.pointer);
        }
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_type
 *
 * PARAMETERS:  node        - Parent Node to be examined
 *
 * RETURN:      Type field from Node whose handle is passed
 *
 * DESCRIPTION: Return the type of a Namespace node
 *
 ******************************************************************************/

acpi_object_type acpi_ns_get_type(struct acpi_namespace_node * node)
{
        ACPI_FUNCTION_TRACE(ns_get_type);

        if (!node) {
                ACPI_WARNING((AE_INFO, "Null Node parameter"));
                return_UINT8(ACPI_TYPE_ANY);
        }

        return_UINT8(node->type);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_local
 *
 * PARAMETERS:  type        - A namespace object type
 *
 * RETURN:      LOCAL if names must be found locally in objects of the
 *              passed type, 0 if enclosing scopes should be searched
 *
 * DESCRIPTION: Returns scope rule for the given object type.
 *
 ******************************************************************************/

u32 acpi_ns_local(acpi_object_type type)
{
        ACPI_FUNCTION_TRACE(ns_local);

        if (!acpi_ut_valid_object_type(type)) {

                /* Type code out of range  */

                ACPI_WARNING((AE_INFO, "Invalid Object Type 0x%X", type));
                return_UINT32(ACPI_NS_NORMAL);
        }

        return_UINT32(acpi_gbl_ns_properties[type] & ACPI_NS_LOCAL);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_internal_name_length
 *
 * PARAMETERS:  info            - Info struct initialized with the
 *                                external name pointer.
 *
 * RETURN:      None
 *
 * DESCRIPTION: Calculate the length of the internal (AML) namestring
 *              corresponding to the external (ASL) namestring.
 *
 ******************************************************************************/

void acpi_ns_get_internal_name_length(struct acpi_namestring_info *info)
{
        const char *next_external_char;
        u32 i;

        ACPI_FUNCTION_ENTRY();

        next_external_char = info->external_name;
        info->num_carats = 0;
        info->num_segments = 0;
        info->fully_qualified = FALSE;

        /*
         * For the internal name, the required length is 4 bytes per segment,
         * plus 1 each for root_prefix, multi_name_prefix_op, segment count,
         * trailing null (which is not really needed, but no there's harm in
         * putting it there)
         *
         * strlen() + 1 covers the first name_seg, which has no path separator
         */
        if (ACPI_IS_ROOT_PREFIX(*next_external_char)) {
                info->fully_qualified = TRUE;
                next_external_char++;

                /* Skip redundant root_prefix, like \\_SB.PCI0.SBRG.EC0 */

                while (ACPI_IS_ROOT_PREFIX(*next_external_char)) {
                        next_external_char++;
                }
        } else {
                /* Handle Carat prefixes */

                while (ACPI_IS_PARENT_PREFIX(*next_external_char)) {
                        info->num_carats++;
                        next_external_char++;
                }
        }

        /*
         * Determine the number of ACPI name "segments" by counting the number of
         * path separators within the string. Start with one segment since the
         * segment count is [(# separators) + 1], and zero separators is ok.
         */
        if (*next_external_char) {
                info->num_segments = 1;
                for (i = 0; next_external_char[i]; i++) {
                        if (ACPI_IS_PATH_SEPARATOR(next_external_char[i])) {
                                info->num_segments++;
                        }
                }
        }

        info->length = (ACPI_NAMESEG_SIZE * info->num_segments) +
            4 + info->num_carats;

        info->next_external_char = next_external_char;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_build_internal_name
 *
 * PARAMETERS:  info            - Info struct fully initialized
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Construct the internal (AML) namestring
 *              corresponding to the external (ASL) namestring.
 *
 ******************************************************************************/

acpi_status acpi_ns_build_internal_name(struct acpi_namestring_info *info)
{
        u32 num_segments = info->num_segments;
        char *internal_name = info->internal_name;
        const char *external_name = info->next_external_char;
        char *result = NULL;
        u32 i;

        ACPI_FUNCTION_TRACE(ns_build_internal_name);

        /* Setup the correct prefixes, counts, and pointers */

        if (info->fully_qualified) {
                internal_name[0] = AML_ROOT_PREFIX;

                if (num_segments <= 1) {
                        result = &internal_name[1];
                } else if (num_segments == 2) {
                        internal_name[1] = AML_DUAL_NAME_PREFIX;
                        result = &internal_name[2];
                } else {
                        internal_name[1] = AML_MULTI_NAME_PREFIX;
                        internal_name[2] = (char)num_segments;
                        result = &internal_name[3];
                }
        } else {
                /*
                 * Not fully qualified.
                 * Handle Carats first, then append the name segments
                 */
                i = 0;
                if (info->num_carats) {
                        for (i = 0; i < info->num_carats; i++) {
                                internal_name[i] = AML_PARENT_PREFIX;
                        }
                }

                if (num_segments <= 1) {
                        result = &internal_name[i];
                } else if (num_segments == 2) {
                        internal_name[i] = AML_DUAL_NAME_PREFIX;
                        result = &internal_name[(acpi_size)i + 1];
                } else {
                        internal_name[i] = AML_MULTI_NAME_PREFIX;
                        internal_name[(acpi_size)i + 1] = (char)num_segments;
                        result = &internal_name[(acpi_size)i + 2];
                }
        }

        /* Build the name (minus path separators) */

        for (; num_segments; num_segments--) {
                for (i = 0; i < ACPI_NAMESEG_SIZE; i++) {
                        if (ACPI_IS_PATH_SEPARATOR(*external_name) ||
                            (*external_name == 0)) {

                                /* Pad the segment with underscore(s) if segment is short */

                                result[i] = '_';
                        } else {
                                /* Convert the character to uppercase and save it */

                                result[i] = (char)toupper((int)*external_name);
                                external_name++;
                        }
                }

                /* Now we must have a path separator, or the pathname is bad */

                if (!ACPI_IS_PATH_SEPARATOR(*external_name) &&
                    (*external_name != 0)) {
                        return_ACPI_STATUS(AE_BAD_PATHNAME);
                }

                /* Move on the next segment */

                external_name++;
                result += ACPI_NAMESEG_SIZE;
        }

        /* Terminate the string */

        *result = 0;

        if (info->fully_qualified) {
                ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
                                  "Returning [%p] (abs) \"\\%s\"\n",
                                  internal_name, internal_name));
        } else {
                ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Returning [%p] (rel) \"%s\"\n",
                                  internal_name, internal_name));
        }

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_internalize_name
 *
 * PARAMETERS:  *external_name          - External representation of name
 *              **Converted name        - Where to return the resulting
 *                                        internal represention of the name
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert an external representation (e.g. "\_PR_.CPU0")
 *              to internal form (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
 *
 *******************************************************************************/

acpi_status
acpi_ns_internalize_name(const char *external_name, char **converted_name)
{
        char *internal_name;
        struct acpi_namestring_info info;
        acpi_status status;

        ACPI_FUNCTION_TRACE(ns_internalize_name);

        if ((!external_name) || (*external_name == 0) || (!converted_name)) {
                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }

        /* Get the length of the new internal name */

        info.external_name = external_name;
        acpi_ns_get_internal_name_length(&info);

        /* We need a segment to store the internal  name */

        internal_name = ACPI_ALLOCATE_ZEROED(info.length);
        if (!internal_name) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        /* Build the name */

        info.internal_name = internal_name;
        status = acpi_ns_build_internal_name(&info);
        if (ACPI_FAILURE(status)) {
                ACPI_FREE(internal_name);
                return_ACPI_STATUS(status);
        }

        *converted_name = internal_name;
        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_externalize_name
 *
 * PARAMETERS:  internal_name_length - Length of the internal name below
 *              internal_name       - Internal representation of name
 *              converted_name_length - Where the length is returned
 *              converted_name      - Where the resulting external name
 *                                    is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Convert internal name (e.g. 5c 2f 02 5f 50 52 5f 43 50 55 30)
 *              to its external (printable) form (e.g. "\_PR_.CPU0")
 *
 ******************************************************************************/

acpi_status
acpi_ns_externalize_name(u32 internal_name_length,
                         const char *internal_name,
                         u32 * converted_name_length, char **converted_name)
{
        u32 names_index = 0;
        u32 num_segments = 0;
        u32 required_length;
        u32 prefix_length = 0;
        u32 i = 0;
        u32 j = 0;

        ACPI_FUNCTION_TRACE(ns_externalize_name);

        if (!internal_name_length || !internal_name || !converted_name) {
                return_ACPI_STATUS(AE_BAD_PARAMETER);
        }

        /* Check for a prefix (one '\' | one or more '^') */

        switch (internal_name[0]) {
        case AML_ROOT_PREFIX:

                prefix_length = 1;
                break;

        case AML_PARENT_PREFIX:

                for (i = 0; i < internal_name_length; i++) {
                        if (ACPI_IS_PARENT_PREFIX(internal_name[i])) {
                                prefix_length = i + 1;
                        } else {
                                break;
                        }
                }

                if (i == internal_name_length) {
                        prefix_length = i;
                }

                break;

        default:

                break;
        }

        /*
         * Check for object names. Note that there could be 0-255 of these
         * 4-byte elements.
         */
        if (prefix_length < internal_name_length) {
                switch (internal_name[prefix_length]) {
                case AML_MULTI_NAME_PREFIX:

                        /* <count> 4-byte names */

                        names_index = prefix_length + 2;
                        num_segments = (u8)
                            internal_name[(acpi_size)prefix_length + 1];
                        break;

                case AML_DUAL_NAME_PREFIX:

                        /* Two 4-byte names */

                        names_index = prefix_length + 1;
                        num_segments = 2;
                        break;

                case 0:

                        /* null_name */

                        names_index = 0;
                        num_segments = 0;
                        break;

                default:

                        /* one 4-byte name */

                        names_index = prefix_length;
                        num_segments = 1;
                        break;
                }
        }

        /*
         * Calculate the length of converted_name, which equals the length
         * of the prefix, length of all object names, length of any required
         * punctuation ('.') between object names, plus the NULL terminator.
         */
        required_length = prefix_length + (4 * num_segments) +
            ((num_segments > 0) ? (num_segments - 1) : 0) + 1;

        /*
         * Check to see if we're still in bounds. If not, there's a problem
         * with internal_name (invalid format).
         */
        if (required_length > internal_name_length) {
                ACPI_ERROR((AE_INFO, "Invalid internal name"));
                return_ACPI_STATUS(AE_BAD_PATHNAME);
        }

        /* Build the converted_name */

        *converted_name = ACPI_ALLOCATE_ZEROED(required_length);
        if (!(*converted_name)) {
                return_ACPI_STATUS(AE_NO_MEMORY);
        }

        j = 0;

        for (i = 0; i < prefix_length; i++) {
                (*converted_name)[j++] = internal_name[i];
        }

        if (num_segments > 0) {
                for (i = 0; i < num_segments; i++) {
                        if (i > 0) {
                                (*converted_name)[j++] = '.';
                        }

                        /* Copy and validate the 4-char name segment */

                        ACPI_COPY_NAMESEG(&(*converted_name)[j],
                                          &internal_name[names_index]);
                        acpi_ut_repair_name(&(*converted_name)[j]);

                        j += ACPI_NAMESEG_SIZE;
                        names_index += ACPI_NAMESEG_SIZE;
                }
        }

        if (converted_name_length) {
                *converted_name_length = (u32) required_length;
        }

        return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_validate_handle
 *
 * PARAMETERS:  handle          - Handle to be validated and typecast to a
 *                                namespace node.
 *
 * RETURN:      A pointer to a namespace node
 *
 * DESCRIPTION: Convert a namespace handle to a namespace node. Handles special
 *              cases for the root node.
 *
 * NOTE: Real integer handles would allow for more verification
 *       and keep all pointers within this subsystem - however this introduces
 *       more overhead and has not been necessary to this point. Drivers
 *       holding handles are typically notified before a node becomes invalid
 *       due to a table unload.
 *
 ******************************************************************************/

struct acpi_namespace_node *acpi_ns_validate_handle(acpi_handle handle)
{

        ACPI_FUNCTION_ENTRY();

        /* Parameter validation */

        if ((!handle) || (handle == ACPI_ROOT_OBJECT)) {
                return (acpi_gbl_root_node);
        }

        /* We can at least attempt to verify the handle */

        if (ACPI_GET_DESCRIPTOR_TYPE(handle) != ACPI_DESC_TYPE_NAMED) {
                return (NULL);
        }

        return (ACPI_CAST_PTR(struct acpi_namespace_node, handle));
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_terminate
 *
 * PARAMETERS:  none
 *
 * RETURN:      none
 *
 * DESCRIPTION: free memory allocated for namespace and ACPI table storage.
 *
 ******************************************************************************/

void acpi_ns_terminate(void)
{
        acpi_status status;

        ACPI_FUNCTION_TRACE(ns_terminate);

        /*
         * Free the entire namespace -- all nodes and all objects
         * attached to the nodes
         */
        acpi_ns_delete_namespace_subtree(acpi_gbl_root_node);

        /* Delete any objects attached to the root node */

        status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
        if (ACPI_FAILURE(status)) {
                return_VOID;
        }

        acpi_ns_delete_node(acpi_gbl_root_node);
        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);

        ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Namespace freed\n"));
        return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_opens_scope
 *
 * PARAMETERS:  type        - A valid namespace type
 *
 * RETURN:      NEWSCOPE if the passed type "opens a name scope" according
 *              to the ACPI specification, else 0
 *
 ******************************************************************************/

u32 acpi_ns_opens_scope(acpi_object_type type)
{
        ACPI_FUNCTION_ENTRY();

        if (type > ACPI_TYPE_LOCAL_MAX) {

                /* type code out of range  */

                ACPI_WARNING((AE_INFO, "Invalid Object Type 0x%X", type));
                return (ACPI_NS_NORMAL);
        }

        return (((u32)acpi_gbl_ns_properties[type]) & ACPI_NS_NEWSCOPE);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_node_unlocked
 *
 * PARAMETERS:  *pathname   - Name to be found, in external (ASL) format. The
 *                            \ (backslash) and ^ (carat) prefixes, and the
 *                            . (period) to separate segments are supported.
 *              prefix_node  - Root of subtree to be searched, or NS_ALL for the
 *                            root of the name space. If Name is fully
 *                            qualified (first s8 is '\'), the passed value
 *                            of Scope will not be accessed.
 *              flags       - Used to indicate whether to perform upsearch or
 *                            not.
 *              return_node - Where the Node is returned
 *
 * DESCRIPTION: Look up a name relative to a given scope and return the
 *              corresponding Node. NOTE: Scope can be null.
 *
 * MUTEX:       Doesn't locks namespace
 *
 ******************************************************************************/

acpi_status
acpi_ns_get_node_unlocked(struct acpi_namespace_node *prefix_node,
                          const char *pathname,
                          u32 flags, struct acpi_namespace_node **return_node)
{
        union acpi_generic_state scope_info;
        acpi_status status;
        char *internal_path;

        ACPI_FUNCTION_TRACE_PTR(ns_get_node_unlocked,
                                ACPI_CAST_PTR(char, pathname));

        /* Simplest case is a null pathname */

        if (!pathname) {
                *return_node = prefix_node;
                if (!prefix_node) {
                        *return_node = acpi_gbl_root_node;
                }

                return_ACPI_STATUS(AE_OK);
        }

        /* Quick check for a reference to the root */

        if (ACPI_IS_ROOT_PREFIX(pathname[0]) && (!pathname[1])) {
                *return_node = acpi_gbl_root_node;
                return_ACPI_STATUS(AE_OK);
        }

        /* Convert path to internal representation */

        status = acpi_ns_internalize_name(pathname, &internal_path);
        if (ACPI_FAILURE(status)) {
                return_ACPI_STATUS(status);
        }

        /* Setup lookup scope (search starting point) */

        scope_info.scope.node = prefix_node;

        /* Lookup the name in the namespace */

        status = acpi_ns_lookup(&scope_info, internal_path, ACPI_TYPE_ANY,
                                ACPI_IMODE_EXECUTE,
                                (flags | ACPI_NS_DONT_OPEN_SCOPE), NULL,
                                return_node);
        if (ACPI_FAILURE(status)) {
                ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "%s, %s\n",
                                  pathname, acpi_format_exception(status)));
        }

        ACPI_FREE(internal_path);
        return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_get_node
 *
 * PARAMETERS:  *pathname   - Name to be found, in external (ASL) format. The
 *                            \ (backslash) and ^ (carat) prefixes, and the
 *                            . (period) to separate segments are supported.
 *              prefix_node  - Root of subtree to be searched, or NS_ALL for the
 *                            root of the name space. If Name is fully
 *                            qualified (first s8 is '\'), the passed value
 *                            of Scope will not be accessed.
 *              flags       - Used to indicate whether to perform upsearch or
 *                            not.
 *              return_node - Where the Node is returned
 *
 * DESCRIPTION: Look up a name relative to a given scope and return the
 *              corresponding Node. NOTE: Scope can be null.
 *
 * MUTEX:       Locks namespace
 *
 ******************************************************************************/

acpi_status
acpi_ns_get_node(struct acpi_namespace_node *prefix_node,
                 const char *pathname,
                 u32 flags, struct acpi_namespace_node **return_node)
{
        acpi_status status;

        ACPI_FUNCTION_TRACE_PTR(ns_get_node, ACPI_CAST_PTR(char, pathname));

        status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
        if (ACPI_FAILURE(status)) {
                return_ACPI_STATUS(status);
        }

        status = acpi_ns_get_node_unlocked(prefix_node, pathname,
                                           flags, return_node);

        (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
        return_ACPI_STATUS(status);
}