dict_ext.c

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/*
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/** Extensions to dictionary structures
 *
 * @file src/lib/util/dict_ext.c
 *
 * @copyright 2020 The FreeRADIUS server project
 * @copyright 2020,2024 Arran Cudbard-Bell <a.cudbardb@freeradius.org>
 */
RCSID("$Id: df1316b79126ecc3dd47c94e497c1be401c45b45 $")
 
#include <freeradius-devel/util/dict_priv.h>
 
static fr_table_num_ordered_t const dict_attr_ext_table[] = {
        { L("name"),                    FR_DICT_ATTR_EXT_NAME                   },
        { L("children"),                FR_DICT_ATTR_EXT_CHILDREN               },
        { L("ref"),                     FR_DICT_ATTR_EXT_REF                    },
        { L("key"),                     FR_DICT_ATTR_EXT_KEY                    },
        { L("vendor"),                  FR_DICT_ATTR_EXT_VENDOR                 },
        { L("da_stack"),                FR_DICT_ATTR_EXT_DA_STACK               },
        { L("enumv"),                   FR_DICT_ATTR_EXT_ENUMV                  },
        { L("namespace"),               FR_DICT_ATTR_EXT_NAMESPACE              },
        { L("protocol-specific"),       FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC      }
};
static size_t dict_attr_ext_table_len = NUM_ELEMENTS(dict_attr_ext_table);
 
/** Fixup name pointer on realloc
 *
 */
static int fr_dict_attr_ext_name_fixup(UNUSED int ext,
                                       TALLOC_CTX *chunk,
                                       void *ext_ptr, UNUSED size_t ext_ptr_len)
{
        fr_dict_attr_t                  *da = talloc_get_type_abort(chunk, fr_dict_attr_t);
 
        da->name = ext_ptr;
 
        return 0;
}
 
/** Copy all enumeration values from one attribute to another
 *
 */
static int fr_dict_attr_ext_enumv_copy(UNUSED int ext,
                                       TALLOC_CTX *chunk_dst,
                                       UNUSED void *dst_ext_ptr, UNUSED size_t dst_ext_len,
                                       UNUSED TALLOC_CTX const *chunk_src,
                                       UNUSED void *src_ext_ptr, UNUSED size_t src_ext_len)
{
        fr_dict_attr_t                  *da_dst = talloc_get_type_abort(chunk_dst, fr_dict_attr_t);
        fr_dict_attr_ext_enumv_t        *src_ext = src_ext_ptr;
        fr_hash_iter_t                  iter;
        fr_dict_enum_value_t            *enumv;
        fr_value_box_t                  box;
        fr_value_box_t const            *vb;
 
        if (!src_ext->value_by_name) return 0;
 
        /*
         *      Add all the enumeration values from
         *      the old attribute to the new attribute.
         */
        for (enumv = fr_hash_table_iter_init(src_ext->value_by_name, &iter);
             enumv;
             enumv = fr_hash_table_iter_next(src_ext->value_by_name, &iter)) {
                fr_dict_enum_ext_attr_ref_t *ref;
                fr_dict_attr_t const *key_child_ref;
 
                key_child_ref = NULL;
 
                /*
                 *      If the enum refers to a child, it MUST refer to a child of a union.
                 *
                 *      We then re-write the ref to point to the newly copied child.
                 */
                ref = fr_dict_enum_ext(enumv, FR_DICT_ENUM_EXT_ATTR_REF);
                if (ref) {
                        fr_dict_attr_t const *ref_parent;
 
                        fr_assert(ref->da->parent->type == FR_TYPE_UNION);
 
                        ref_parent = fr_dict_attr_by_name(NULL, da_dst->parent, ref->da->parent->name);
                        fr_assert(ref_parent);
                        fr_assert(ref_parent->type == FR_TYPE_UNION);
 
                        /*
                         *      The reference has to exist.
                         */
                        key_child_ref = fr_dict_attr_by_name(NULL, ref_parent, ref->da->name);
                        fr_assert(key_child_ref != NULL);
                }
 
                vb = enumv->value;
                if (da_dst->type != enumv->value->type) {
                        fr_assert(fr_type_is_integer(enumv->value->type));
                        fr_assert(fr_type_is_integer(da_dst->type));
 
                        if (fr_value_box_cast(da_dst, &box, da_dst->type, NULL, enumv->value) < 0) return -1;
 
                        vb = &box;
                }
 
                if (dict_attr_enum_add_name(da_dst, enumv->name, vb,
                                            true, true, key_child_ref) < 0) return -1;
        }
 
        return 0;
}
 
/** Rediscover the parent of this attribute, and cache it
 *
 */
static int fr_dict_attr_ext_vendor_copy(UNUSED int ext,
                                        TALLOC_CTX *chunk_dst,
                                        void *dst_ext_ptr, UNUSED size_t dst_ext_len,
                                        UNUSED TALLOC_CTX const *chunk_src,
                                        void *src_ext_ptr, UNUSED size_t src_ext_len)
{
        fr_dict_attr_t                  *da_dst = talloc_get_type_abort(chunk_dst, fr_dict_attr_t);
        fr_dict_attr_ext_vendor_t       *dst_ext = dst_ext_ptr, *src_ext = src_ext_ptr;
        fr_dict_attr_t const            **da_stack;
        fr_dict_attr_t const            *old_vendor = src_ext->vendor;
        fr_dict_attr_t const            *new_vendor, *da;
 
        if (!old_vendor) {
                dst_ext->vendor = NULL;
                return 0;
        }
 
        /*
         *      If we have a da stack, see if we can
         *      find a vendor at the same depth as
         *      the old depth.
         */
        da_stack = fr_dict_attr_da_stack(da_dst);
        if (da_stack) {
                new_vendor = da_stack[old_vendor->depth];
                if ((new_vendor->type == old_vendor->type) && (new_vendor->attr == old_vendor->attr)) {
                        dst_ext->vendor = new_vendor;
                        return 0;
                }
        }
 
        /*
         *      Otherwise traverse the parent list
         *      looking for the vendor.
         *
         *      Theoretically the attribute could
         *      have been moved to a different depth.
         */
        for (da = da_dst->parent; da; da = da->parent) {
                if ((da->type == old_vendor->type) && (da->attr == old_vendor->attr)) {
                        dst_ext->vendor = da;
                        return 0;
                }
        }
 
        return -1;
}
 
static int dict_ext_protocol_specific_copy(UNUSED int ext,
                                           TALLOC_CTX *dst_chunk,
                                           void *dst_ext_ptr, size_t dst_ext_len,
                                           TALLOC_CTX const *src_chunk,
                                           void *src_ext_ptr, size_t src_ext_len)
{
        fr_dict_attr_t const            *from = talloc_get_type_abort_const(src_chunk, fr_dict_attr_t);
        fr_dict_protocol_t const        *from_proto = fr_dict_protocol(from->dict);
        fr_dict_attr_t                  *to = talloc_get_type_abort(dst_chunk, fr_dict_attr_t);
        fr_dict_protocol_t const        *to_proto = fr_dict_protocol(to->dict);
 
        /*
         *      Whilst it's not strictly disallowed, we can't do anything
         *      sane without an N x N matrix of copy functions for different
         *      protocols.  Maybe we should add that at some point, but for
         *      now, just ignore the copy.
         */
        if (from->dict != to->dict) return 0;
 
        /*
         *      Sanity checks...
         */
        if (unlikely(from_proto->attr.flags.len != src_ext_len)) {
                fr_strerror_printf("Protocol specific extension length mismatch in source attribute %s.  Expected %zu, got %zu",
                                   from->name,
                                   fr_dict_protocol(from->dict)->attr.flags.len, fr_dict_protocol(to->dict)->attr.flags.len);
                return -1;
        }
 
        if (unlikely(to_proto->attr.flags.len != dst_ext_len)) {
                fr_strerror_printf("Protocol specific extension length mismatch in destintion attribute %s.  Expected %zu, got %zu",
                                   to->name,
                                   fr_dict_protocol(to->dict)->attr.flags.len, fr_dict_protocol(to->dict)->attr.flags.len);
                return -1;
        }
 
        /*
         *      The simple case... No custom copy function, just memcpy
         */
        if (!to_proto->attr.flags.copy) {
                memcpy(dst_ext_ptr, src_ext_ptr, src_ext_len);
                return 0;
        }
 
        /*
         *      Call the custom copy function.  This is only needed if
         *      there are heap allocated values, like strings, which
         *      need copying from sources flags to the destination.
         */
        return to_proto->attr.flags.copy(dst_chunk, dst_ext_ptr, src_ext_ptr);
}
 
/** Rediscover the key reference for this attribute, and cache it
 *
 *  The UNION has a ref to the key DA, which is a sibling of the union.
 */
static int fr_dict_attr_ext_key_copy(UNUSED int ext,
                                     TALLOC_CTX *chunk_dst,
                                     void *dst_ext_ptr, UNUSED size_t dst_ext_len,
                                     UNUSED TALLOC_CTX const *chunk_src,
                                     void *src_ext_ptr, UNUSED size_t src_ext_len)
{
        fr_dict_attr_t                  *da_dst = talloc_get_type_abort(chunk_dst, fr_dict_attr_t);
        fr_dict_attr_ext_ref_t          *dst_ext = dst_ext_ptr, *src_ext = src_ext_ptr;
        fr_dict_attr_t const            *key;
 
        fr_assert(da_dst->parent);
        fr_assert(da_dst->type == FR_TYPE_UNION);
        fr_assert(src_ext->type == FR_DICT_ATTR_REF_KEY);
 
        fr_assert(da_dst->parent != src_ext->ref->parent);
 
        key = fr_dict_attr_by_name(NULL, da_dst->parent, src_ext->ref->name);
        if (!key) {
                fr_strerror_printf("Parent %s has no key attribute '%s'",
                                   da_dst->parent->name, src_ext->ref->name);
                return -1;
        }
 
        dst_ext->ref = key;     /* @todo - is ref_target? */
 
        return 0;
}
 
/** Holds additional information about extension structures
 *
 */
fr_ext_t const fr_dict_attr_ext_def = {
        .offset_of_exts = offsetof(fr_dict_attr_t, ext),
        .name_table     = dict_attr_ext_table,
        .name_table_len = &dict_attr_ext_table_len,
        .max            = FR_DICT_ATTR_EXT_MAX,
        .info           =  (fr_ext_info_t[]){ /* -Wgnu-flexible-array-initializer */
                [FR_DICT_ATTR_EXT_NAME]         = {
                                                        .min = sizeof(char),
                                                        .has_hdr = true,
                                                        .fixup = fr_dict_attr_ext_name_fixup,
                                                        .can_copy = false,              /* Name may change, and we can only set it once */
                                                },
                [FR_DICT_ATTR_EXT_CHILDREN]     = {
                                                        .min = sizeof(fr_dict_attr_ext_children_t),
                                                        .can_copy = false,              /* Limitation in hashing scheme we use */
                                                },
                [FR_DICT_ATTR_EXT_REF]          = {
                                                        .min = sizeof(fr_dict_attr_ext_ref_t),
                                                        /*
                                                         *      Copying a CLONE or ENUM is OK.
                                                         *
                                                         *      @todo - copying an ALIAS will copy the name,
                                                         *      but the ref will be to the original destination DA.
                                                         */
                                                        .can_copy = true,
                                                },
                [FR_DICT_ATTR_EXT_KEY]          = {
                                                        /*
                                                         *      keys are mostly like refs, but they're not
                                                         *      auto-followed like refs.  The difference is
                                                         *      that we can copy a ref as-is, because the ref
                                                         *      points to something which exists, and is
                                                         *      independent of us.
                                                         *
                                                         *      But a key ref is only used in a UNION, and
                                                         *      then points to the key attribute of the parent
                                                         *      structure.  If we do allow copying a UNION, we
                                                         *      will also need to specify the new key ref.
                                                         *
                                                         *      So we need a special copy function.
                                                         */
                                                        .min = sizeof(fr_dict_attr_ext_ref_t),
                                                        .copy = fr_dict_attr_ext_key_copy,
                                                        .can_copy = true,
                                                },
                [FR_DICT_ATTR_EXT_VENDOR]       = {
                                                        .min = sizeof(fr_dict_attr_ext_vendor_t),
                                                        .can_copy = true,
                                                        .copy = fr_dict_attr_ext_vendor_copy
                                                },
                [FR_DICT_ATTR_EXT_DA_STACK]     = {
                                                        .min = sizeof(fr_dict_attr_ext_da_stack_t),
                                                        .has_hdr = true,
                                                        .can_copy = false               /* Reinitialised for each new attribute */
                                                },
                [FR_DICT_ATTR_EXT_ENUMV]        = {
                                                        .min = sizeof(fr_dict_attr_ext_enumv_t),
                                                        .can_copy = true,
                                                        .copy = fr_dict_attr_ext_enumv_copy
                                                },
                [FR_DICT_ATTR_EXT_NAMESPACE]    = {
                                                        .min = sizeof(fr_dict_attr_ext_namespace_t),
                                                        .can_copy = false,              /* Same limitation as ext_children */
                                                },
                [FR_DICT_ATTR_EXT_PROTOCOL_SPECIFIC] = {
                                                        .min = FR_EXT_ALIGNMENT,        /* allow for one byte of protocol stuff */
                                                        .has_hdr = true,                /* variable sized */
                                                        .copy = dict_ext_protocol_specific_copy,
                                                        .can_copy = true                /* Use the attr.flags.copy function */
                                                },
                [FR_DICT_ATTR_EXT_MAX]          = {}
        }
};
 
static fr_table_num_ordered_t const dict_enum_ext_table[] = {
        { L("attr_ref"),        FR_DICT_ENUM_EXT_ATTR_REF       }
};
static size_t dict_enum_ext_table_len = NUM_ELEMENTS(dict_enum_ext_table);
 
void fr_dict_attr_ext_debug(fr_dict_attr_t const *da)
{
        fr_ext_debug(&fr_dict_attr_ext_def, da->name, da);
}
 
/** Holds additional information about extension structures
 *
 */
fr_ext_t const fr_dict_enum_ext_def = {
        .offset_of_exts = offsetof(fr_dict_enum_value_t, ext),
        .name_table     = dict_enum_ext_table,
        .name_table_len = &dict_enum_ext_table_len,
        .max            = FR_DICT_ENUM_EXT_MAX,
        .info           = (fr_ext_info_t[]){ /* -Wgnu-flexible-array-initializer */
                [FR_DICT_ENUM_EXT_ATTR_REF] = {
                                                        .min = sizeof(fr_dict_enum_ext_attr_ref_t),
                                                        .can_copy = true
                                                },
                [FR_DICT_ENUM_EXT_MAX]          = {}
        }
};