tmpl_eval.c

Go to the documentation of this file.

/*
 *   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
 */
 
/**
 * $Id: f22adf425b831f0eb785936f0eb882db34a8d127 $
 *
 * @brief #fr_pair_t template functions
 * @file src/lib/server/tmpl_eval.c
 *
 * @ingroup AVP
 *
 * @copyright 2014-2020 The FreeRADIUS server project
 */
RCSID("$Id: f22adf425b831f0eb785936f0eb882db34a8d127 $")
 
#define _TMPL_PRIVATE 1
 
#include <freeradius-devel/server/exec.h>
#include <freeradius-devel/server/exec_legacy.h>
#include <freeradius-devel/server/tmpl.h>
#include <freeradius-devel/server/tmpl_dcursor.h>
#include <freeradius-devel/server/client.h>
#include <freeradius-devel/unlang/call.h>
 
#include <freeradius-devel/util/atexit.h>
#include <freeradius-devel/util/edit.h>
 
 
static fr_dict_t const *dict_freeradius;
static fr_dict_t const *dict_radius;
 
extern fr_dict_autoload_t tmpl_dict[];
fr_dict_autoload_t tmpl_dict[] = {
        { .out = &dict_freeradius, .proto = "freeradius" },
        { .out = &dict_radius, .proto = "radius" }, /* @todo - remove RADIUS from the server core... */
        DICT_AUTOLOAD_TERMINATOR
};
 
/** Placeholder attribute for uses of unspecified attribute references
 */
extern fr_dict_attr_t const *tmpl_attr_unspec;
fr_dict_attr_t const *tmpl_attr_unspec;
 
 
/** Resolve attribute #fr_pair_list_t value to an attribute list.
 *
 * The value returned is a pointer to the pointer of the HEAD of a #fr_pair_t list in the
 * #request_t. If the head of the list changes, the pointer will still be valid.
 *
 * @param[in] request containing the target lists.
 * @param[in] list #fr_pair_list_t value to resolve to #fr_pair_t list. Will be NULL if list
 *      name couldn't be resolved.
 * @return a pointer to the HEAD of a list in the #request_t.
 *
 * @see tmpl_dcursor_init
 */
fr_pair_list_t *tmpl_list_head(request_t *request, fr_dict_attr_t const *list)
{
        if (!request) return NULL;
 
        if (list == request_attr_request) {
                if (!request->packet) return NULL;
                return &request->request_pairs;
        }
 
        if (list == request_attr_reply) {
                if (!request->reply) return NULL;
                return &request->reply_pairs;
        }
 
        if (list == request_attr_control) return &request->control_pairs;
 
        if (list == request_attr_state) return &request->session_state_pairs;
 
        if (list == request_attr_local) return &request->local_pairs;
 
        RWDEBUG2("List \"%s\" is not available", tmpl_list_name(list, "<INVALID>"));
 
        return NULL;
}
 
/** Return the correct TALLOC_CTX to alloc #fr_pair_t in, for a list
 *
 * Allocating new #fr_pair_t in the context of a #request_t is usually wrong.
 * #fr_pair_t should be allocated in the context of a #fr_packet_t, so that if the
 * #fr_packet_t is freed before the #request_t, the associated #fr_pair_t lists are
 * freed too.
 *
 * @param[in] request containing the target lists.
 * @param[in] list #fr_pair_list_t value to resolve to TALLOC_CTX.
 * @return
 *      - TALLOC_CTX on success.
 *      - NULL on failure.
 *
 * @see tmpl_pair_list
 */
TALLOC_CTX *tmpl_list_ctx(request_t *request, fr_dict_attr_t const *list)
{
        if (!request) return NULL;
 
        if (list == request_attr_request) return request->request_ctx;
 
        if (list == request_attr_reply) return request->reply_ctx;
 
        if (list == request_attr_control) return request->control_ctx;
 
        if (list == request_attr_state) return request->session_state_ctx;
 
        if (list == request_attr_local) return request->local_ctx;
 
        return NULL;
}
 
/** Resolve a list to the #fr_packet_t holding the HEAD pointer for a #fr_pair_t list
 *
 * Returns a pointer to the #fr_packet_t that holds the HEAD pointer of a given list,
 * for the current #request_t.
 *
 * @param[in] request To resolve list in.
 * @param[in] list #fr_pair_list_t value to resolve to #fr_packet_t.
 * @return
 *      - #fr_packet_t on success.
 *      - NULL on failure.
 *
 * @see tmpl_pair_list
 */
fr_packet_t *tmpl_packet_ptr(request_t *request, fr_dict_attr_t const *list)
{
        if (list == request_attr_request) return request->packet;
 
        if (list == request_attr_reply) return request->reply;
 
        return NULL;
}
 
/** Resolve a #tmpl_request_ref_t to a #request_t.
 *
 * Sometimes #request_t structs may be chained to each other, as is the case
 * when internally proxying EAP. This function resolves a #tmpl_request_ref_t
 * to a #request_t higher in the chain than the current #request_t.
 *
 * @see tmpl_pair_list
 * @param[in,out] context       #request_t to start resolving from, and where to write
 *                              a pointer to the resolved #request_t back to.
 * @param[in] rql               list of request qualifiers to follow.
 * @return
 *      - 0 if request is valid in this context.
 *      - -1 if request is not valid in this context.
 */
int tmpl_request_ptr(request_t **context, FR_DLIST_HEAD(tmpl_request_list) const *rql)
{
        tmpl_request_t *rr = NULL;
        request_t *request = *context;
 
        while ((rr = tmpl_request_list_next(rql, rr))) {
                switch (rr->request) {
                case REQUEST_CURRENT:
                        continue;       /* noop */
 
                case REQUEST_PARENT:    /* Navigate up one level */
                        if (!request->parent) return -1;
                        request = request->parent;
                        break;
 
                case REQUEST_OUTER:     /* Navigate to the outermost request */
                        if (!request->parent) return -1;
                        while (request->parent) request = request->parent;
                        break;
 
                case REQUEST_UNKNOWN:
                default:
                        fr_assert(0);
                        return -1;
                }
        }
 
        *context = request;
 
        return 0;
}
 
/** Return the native data type of the expression
 *
 * @param[in] vpt       to determine the type of.
 * @return
 *      - FR_TYPE_NULL if the type of the #tmpl_t can't be determined.
 *      - The data type we'd expect the #tmpl_t to produce at runtime
 *        when expanded.
 */
fr_type_t tmpl_expanded_type(tmpl_t const *vpt)
{
        /*
         *      Regexes can't be expanded
         */
        if (tmpl_contains_regex(vpt)) return FR_TYPE_NULL;
 
        /*
         *      Casts take precedence over everything.
         */
        if (tmpl_rules_cast(vpt) != FR_TYPE_NULL) return tmpl_rules_cast(vpt);
 
        /*
         *      Anything that's not a bare word will
         *      be a string unless there's a casting
         *      operator.
         */
        if (vpt->quote != T_BARE_WORD) return FR_TYPE_STRING;
 
        switch (vpt->type) {
        case TMPL_TYPE_ATTR:
                return tmpl_attr_tail_da(vpt)->type;
 
        case TMPL_TYPE_DATA:
                return tmpl_value_type(vpt);
 
        case TMPL_TYPE_XLAT:
        case TMPL_TYPE_EXEC:
                return FR_TYPE_STRING;
 
        default:
                break;
        }
 
        return FR_TYPE_NULL;
}
 
/** Expand a #tmpl_t to a string writing the result to a buffer
 *
 * The intended use of #tmpl_expand and #tmpl_aexpand is for modules to easily convert a #tmpl_t
 * provided by the conf parser, into a usable value.
 * The value returned should be raw and undoctored for #FR_TYPE_STRING and #FR_TYPE_OCTETS types,
 * and the printable (string) version of the data for all others.
 *
 * Depending what arguments are passed, either copies the value to buff, or writes a pointer
 * to a string buffer to out. This allows the most efficient access to the value resolved by
 * the #tmpl_t, avoiding unnecessary string copies.
 *
 * @note This function is used where raw string values are needed, which may mean the string
 *      returned may be binary data or contain unprintable chars. #fr_snprint or #fr_asprint
 *      should be used before using these values in debug statements. #is_printable can be used to
 *      check if the string only contains printable chars.
 *
 * @param[out] out              Where to write a pointer to the string buffer. On return may
 *                              point to buff if buff was used to store the value. Otherwise will
 *                              point to a #fr_value_box_t buffer, or the name of the template.
 *                              Must not be NULL.
 * @param[out] buff             Expansion buffer, may be NULL except for the following types:
 *                              - #TMPL_TYPE_EXEC
 *                              - #TMPL_TYPE_XLAT
 *                              - input type non-string, output type string
 * @param[in] bufflen           Length of expansion buffer. Must be >= 2.
 * @param[in] request           Current request.
 * @param[in] vpt               to expand. Must be one of the following types:
 *                              - #TMPL_TYPE_EXEC
 *                              - #TMPL_TYPE_XLAT
 *                              - #TMPL_TYPE_ATTR
 *                              - #TMPL_TYPE_DATA
 * @param dst_type              FR_TYPE_* matching out pointer.  @see tmpl_expand.
 * @return
 *      - -1 on failure.
 *      - The length of data written out.
 */
ssize_t _tmpl_to_type(void *out,
                      uint8_t *buff, size_t bufflen,
                      request_t *request,
                      tmpl_t const *vpt,
                      fr_type_t dst_type)
{
        fr_value_box_t          value_to_cast = FR_VALUE_BOX_INITIALISER_NULL(value_to_cast);
        fr_value_box_t          value_from_cast = FR_VALUE_BOX_INITIALISER_NULL(value_from_cast);
        fr_value_box_t const    *to_cast = NULL;
        fr_value_box_t const    *from_cast = NULL;
 
        fr_pair_t               *vp = NULL;
 
        ssize_t                 slen = -1;      /* quiet compiler */
 
        TMPL_VERIFY(vpt);
 
        fr_assert(!tmpl_needs_resolving(vpt));
        fr_assert(!fr_type_is_structural(dst_type));
 
        fr_assert(!buff || (bufflen >= 2));
 
        switch (vpt->type) {
        case TMPL_TYPE_EXEC:
                RDEBUG4("EXPAND TMPL EXEC");
                if (!buff) {
                        REDEBUG("Missing expansion buffer for exec");
                        return -1;
                }
 
                if (radius_exec_program_legacy((char *) buff, bufflen, request, vpt->name, NULL,
                                        true, false, fr_time_delta_from_sec(EXEC_TIMEOUT)) != 0) return -1;
 
                fr_value_box_strdup_shallow(&value_to_cast, NULL, (char *) buff, true);
                to_cast = &value_to_cast;
                break;
 
        case TMPL_TYPE_XLAT:
                RDEBUG4("EXPAND TMPL XLAT PARSED");
 
                /* No EXPAND <xlat> here as the xlat code does it */
 
                if (!buff) {
                        REDEBUG("Missing expansion buffer for dynamic expansion");
                        return -1;
                }
 
                /* Error in expansion, this is distinct from zero length expansion */
                slen = xlat_eval_compiled((char *) buff, bufflen, request, tmpl_xlat(vpt), NULL, NULL);
                if (slen < 0) return slen;
 
                fr_value_box_bstrndup_shallow(&value_to_cast, NULL, (char *) buff, slen, true);
                to_cast = &value_to_cast;
                break;
 
        case TMPL_TYPE_ATTR:
                RDEBUG4("EXPAND TMPL ATTR");
                if (tmpl_find_vp(&vp, request, vpt) < 0) {
                        REDEBUG("Failed to find attribute %s", vpt->name);
                        return -2;
                }
 
                to_cast = &vp->data;
                break;
 
        case TMPL_TYPE_DATA:
                RDEBUG4("EXPAND TMPL DATA");
                to_cast = tmpl_value(vpt);
                break;
 
        /*
         *      We should never be expanding these.
         */
        case TMPL_TYPE_UNINITIALISED:
        case TMPL_TYPE_DATA_UNRESOLVED:
        case TMPL_TYPE_EXEC_UNRESOLVED:
        case TMPL_TYPE_ATTR_UNRESOLVED:
        case TMPL_TYPE_XLAT_UNRESOLVED:
        case TMPL_TYPE_REGEX:
        case TMPL_TYPE_REGEX_UNCOMPILED:
        case TMPL_TYPE_REGEX_XLAT:
        case TMPL_TYPE_REGEX_XLAT_UNRESOLVED:
        case TMPL_TYPE_MAX:
                fr_assert(0);
                return -1;
        }
 
        /*
         *      Same type, just copy the value.
         *
         *      If the input is exec/xlat, then we can just copy the output ptr to the caller, as it's already
         *      pointing to "buff".
         */
        if (to_cast->type == dst_type) {
                from_cast = to_cast;
                goto do_copy;
        }
 
        /*
         *      We need a buffer to hold ouput data which can be returned to the caller.
         */
        if (fr_type_is_variable_size(dst_type) && !buff) {
                REDEBUG("Missing expansion buffer for %s -> %s cast", fr_type_to_str(to_cast->type), fr_type_to_str(dst_type));
                return -1;
        }
 
        /*
         *      Convert to the correct data type.
         */
        if (fr_value_box_cast(request, &value_from_cast, dst_type, NULL, to_cast)) {
                RPEDEBUG("Failed casting input %pV to data type %s", to_cast, fr_type_to_str(dst_type));
                return -1;
        }
 
        from_cast = &value_from_cast;
 
        /*
         *      If the output is a talloc'd buffer, then we have to copy it to "buff", so that we can return
         *      the pointer to the caller.
         */
        if (fr_type_is_variable_size(dst_type)) {
                size_t len = from_cast->vb_length + (dst_type == FR_TYPE_STRING);
 
                if (bufflen < len) {
                        REDEBUG("Expansion buffer is too small.  Buffer is %zu bytes, and we need %zu bytes",
                                bufflen, len);
                        return -1;
                }
 
                /*
                 *      Copy the data to the buffer, and clear the alloc'd pointer.
                 */
                memcpy(buff, from_cast->vb_octets, len);
                len = from_cast->vb_length;
                fr_value_box_clear(&value_from_cast);
 
                /*
                 *      "out" is a pointer to a char* or uint8_t*
                 */
                *(uint8_t **) out = buff;
 
                return len;     /* the amount of data we copied above */
        }
 
do_copy:
        RDEBUG4("Copying %zu bytes to %p from offset %zu",
                fr_value_box_field_sizes[dst_type], out, fr_value_box_offsets[dst_type]);
 
        fr_value_box_memcpy_out(out, from_cast);
 
        return from_cast->vb_length;
}
 
/** Expand a template to a string, allocing a new buffer to hold the string
 *
 * The intended use of #tmpl_expand and #tmpl_aexpand is for modules to easily convert a #tmpl_t
 * provided by the conf parser, into a usable value.
 * The value returned should be raw and undoctored for #FR_TYPE_STRING and #FR_TYPE_OCTETS types,
 * and the printable (string) version of the data for all others.
 *
 * This function will always duplicate values, whereas #tmpl_expand may return a pointer to an
 * existing buffer.
 *
 * @note This function is used where raw string values are needed, which may mean the string
 *      returned may be binary data or contain unprintable chars. #fr_snprint or #fr_asprint should
 *      be used before using these values in debug statements. #is_printable can be used to check
 *      if the string only contains printable chars.
 *
 * @note The type (char or uint8_t) can be obtained with talloc_get_type, and may be used as a
 *      hint as to how to process or print the data.
 *
 * @param ctx           to allocate new buffer in.
 * @param out           Where to write pointer to the new buffer.
 * @param request       Current request.
 * @param vpt           to expand. Must be one of the following types:
 *                      - #TMPL_TYPE_DATA_UNRESOLVED
 *                      - #TMPL_TYPE_EXEC
 *                      - #TMPL_TYPE_XLAT
 *                      - #TMPL_TYPE_ATTR
 *                      - #TMPL_TYPE_DATA
 * @param escape xlat   escape function (only used for TMPL_TYPE_XLAT_UNRESOLVED_* types).
 * @param escape_ctx    xlat escape function data (only used for TMPL_TYPE_XLAT_UNRESOLVED_* types).
 * @param dst_type      FR_TYPE_* matching out pointer.  @see tmpl_aexpand.
 * @return
 *      - -1 on failure.
 *      - The length of data written to buff, or pointed to by out.
 */
ssize_t _tmpl_to_atype(TALLOC_CTX *ctx, void *out,
                       request_t *request,
                       tmpl_t const *vpt,
                       xlat_escape_legacy_t escape, void const *escape_ctx,
                       fr_type_t dst_type)
{
        fr_value_box_t          *vb_out, *vb_in = NULL;
        fr_value_box_t          value = FR_VALUE_BOX_INITIALISER_NULL(value);
 
        fr_pair_t               *vp = NULL;
        bool                    needs_dup = false;
 
        ssize_t                 slen = -1;
        int                     ret;
 
        TALLOC_CTX              *tmp_ctx = NULL;
        char                    *str = NULL;
 
        TMPL_VERIFY(vpt);
 
        fr_assert(!tmpl_needs_resolving(vpt));
        fr_assert(!fr_type_is_structural(dst_type));
 
        switch (vpt->type) {
        case TMPL_TYPE_EXEC:
                RDEBUG4("EXPAND TMPL EXEC");
 
                MEM(tmp_ctx = talloc_new(ctx));
 
                MEM(fr_value_box_bstr_alloc(tmp_ctx, &str, &value, NULL, 1024, true));
                if (radius_exec_program_legacy(str, 1024, request, vpt->name, NULL,
                                               true, false, fr_time_delta_from_sec(EXEC_TIMEOUT)) != 0) {
                error:
                        talloc_free(tmp_ctx);
                        return -1;
                }
 
                fr_value_box_strtrim(tmp_ctx, &value);
                vb_in = &value;
                break;
 
        case TMPL_TYPE_XLAT:
        case TMPL_TYPE_REGEX_XLAT:
                RDEBUG4("EXPAND TMPL XLAT STRUCT");
 
                MEM(tmp_ctx = talloc_new(ctx));
 
                /*
                 *      An error in expansion is distinct from zero
                 *      length expansion.  Zero-length strings are
                 *      permitted.
                 */
                slen = xlat_aeval_compiled(tmp_ctx, &str, request, tmpl_xlat(vpt), escape, escape_ctx);
                if (slen < 0) {
                        RPEDEBUG("Failed expanding %s", vpt->name);
                        goto error;
                }
 
                /*
                 *      The output is a string which might get cast to something later.
                 */
                fr_value_box_bstrndup_shallow(&value, NULL, str, (size_t) slen, false);
                vb_in = &value;
                break;
 
        case TMPL_TYPE_ATTR:
                RDEBUG4("EXPAND TMPL ATTR");
 
                ret = tmpl_find_vp(&vp, request, vpt);
                if (ret < 0) {
                        RDEBUG("Failed finding attribute %s", vpt->name);
                        talloc_free(tmp_ctx);
                        return -2;
                }
 
                fr_assert(vp);
 
                needs_dup = true;
                vb_in = &vp->data;
                break;
 
        case TMPL_TYPE_DATA:
                RDEBUG4("EXPAND TMPL DATA");
 
                needs_dup = true;
                vb_in = UNCONST(fr_value_box_t *, tmpl_value(vpt));
                break;
 
        /*
         *      We should never be expanding these.
         */
        case TMPL_TYPE_UNINITIALISED:
        case TMPL_TYPE_EXEC_UNRESOLVED:
        case TMPL_TYPE_REGEX:
        case TMPL_TYPE_REGEX_UNCOMPILED:
        case TMPL_TYPE_REGEX_XLAT_UNRESOLVED:
        case TMPL_TYPE_ATTR_UNRESOLVED:
        case TMPL_TYPE_DATA_UNRESOLVED:
        case TMPL_TYPE_XLAT_UNRESOLVED:
        case TMPL_TYPE_MAX:
                fr_assert(0);
                goto error;
        }
 
        fr_assert(vb_in != NULL);
        VALUE_BOX_VERIFY(vb_in);
 
        /*
         *      If the output is a value-box, we might cast it using the tmpl cast.  When done, we just copy
         *      the value-box.
         */
        if (dst_type == FR_TYPE_VALUE_BOX) {
                fr_type_t cast_type;
 
                MEM(vb_out = fr_value_box_alloc_null(ctx));
                cast_type = tmpl_rules_cast(vpt);
 
                if (cast_type == FR_TYPE_NULL) {
                        if (needs_dup) {
                                if (unlikely(fr_value_box_copy(vb_out, vb_out, vb_in) < 0)) {
                                        talloc_free(vb_out);
                                        goto failed_cast;
                                }
                        } else {
                                fr_value_box_steal(vb_out, vb_out, vb_in);
                        }
 
                } else {
                        ret = fr_value_box_cast(vb_out, vb_out, cast_type, NULL, vb_in);
 
                        if (ret < 0) {
                                talloc_free(vb_out);
                                dst_type = cast_type;
 
                        failed_cast:
                                RPEDEBUG("Failed casting input %pV to data type %s", vb_in, fr_type_to_str(dst_type));
                                goto error;
                        }
                }
 
                talloc_free(tmp_ctx);
                VALUE_BOX_VERIFY(vb_out);
                *(fr_value_box_t **) out = vb_out;
                return 0;
        }
 
        /*
         *      Cast the data to the correct type.  Which also allocates any variable sized buffers from the
         *      output ctx.
         */
        if (dst_type != vb_in->type) {
                if (vb_in == &value) {
                        size_t datalen;
                        fr_slen_t parse_len;
 
                        fr_assert(tmp_ctx != NULL);
                        fr_assert(str != NULL);
                        fr_assert(dst_type != FR_TYPE_STRING); /* exec / xlat returned string in 'str' */
 
                        datalen = talloc_strlen(str);
                        parse_len = fr_value_box_from_str(ctx, &value, dst_type, NULL, str, datalen, NULL);
                        if (parse_len < 0) {
                                fr_value_box_bstrndup_shallow(&value, NULL, str, datalen, false);
                                goto failed_cast;
                        }
 
                } else {
                        ret = fr_value_box_cast(ctx, &value, dst_type, NULL, vb_in);
                        if (ret < 0) goto failed_cast;
                }
 
                /*
                 *      The input data has been converted, and placed into value.
                 */
                vb_in = &value;
 
        } else if (fr_type_is_variable_size(dst_type)) {
                /*
                 *      The output type is the same, but variable sized types need to be either duplicated, or
                 *      reparented.
                 */
                if (needs_dup) {
                        fr_assert(vb_in != &value);
 
                        if (unlikely(fr_value_box_copy(ctx, &value, vb_in) < 0)) goto failed_cast;
                        vb_in = &value;
                } else {
                        fr_assert(dst_type == FR_TYPE_STRING);
                        fr_assert(str != NULL);
 
                        (void) talloc_steal(ctx, str); /* ensure it's parented from the right context */
                        fr_assert(vb_in == &value);
                }
        } /* else the output type is a leaf, and is the same data type as the input */
 
        RDEBUG4("Copying %zu bytes to %p from offset %zu",
                fr_value_box_field_sizes[dst_type], out, fr_value_box_offsets[dst_type]);
 
        fr_value_box_memcpy_out(out, vb_in);
 
        /*
         *      Frees any memory allocated for temporary buffers
         *      in this function.
         */
        talloc_free(tmp_ctx);
 
        return vb_in->vb_length;
}
 
/** Copy pairs matching a #tmpl_t in the current #request_t
 *
 * @param ctx to allocate new #fr_pair_t in.
 * @param out Where to write the copied #fr_pair_t (s).
 * @param request The current #request_t.
 * @param vpt specifying the #fr_pair_t type or list to copy.
 *      Must be one of the following types:
 *      - #TMPL_TYPE_ATTR
 * @return
 *      - -1 if no matching #fr_pair_t could be found.
 *      - -2 if list could not be found (doesn't exist in current #request_t).
 *      - -3 if context could not be found (no parent #request_t available).
 *      - -4 on memory allocation error.
 */
int tmpl_copy_pairs(TALLOC_CTX *ctx, fr_pair_list_t *out, request_t *request, tmpl_t const *vpt)
{
        fr_pair_t               *vp;
        fr_dcursor_t            from;
        tmpl_dcursor_ctx_t      cc;
        int err;
 
        TMPL_VERIFY(vpt);
 
        fr_assert(tmpl_is_attr(vpt));
 
        for (vp = tmpl_dcursor_init(&err, NULL, &cc, &from, request, vpt);
             vp;
             vp = fr_dcursor_next(&from)) {
                vp = fr_pair_copy(ctx, vp);
                if (!vp) {
                        fr_pair_list_free(out);
                        fr_strerror_const("Out of memory");
                        err = -4;
                        break;
                }
                fr_pair_append(out, vp);
        }
        tmpl_dcursor_clear(&cc);
 
        return err;
}
 
 
/** Copy children of pairs matching a #tmpl_t in the current #request_t
 *
 * @param ctx to allocate new #fr_pair_t in.
 * @param out Where to write the copied #fr_pair_t (s).
 * @param request The current #request_t.
 * @param vpt specifying the #fr_pair_t type or list to copy.
 *      Must be one of the following types:
 *      - #TMPL_TYPE_ATTR
 * @return
 *      - -1 if no matching #fr_pair_t could be found.
 *      - -2 if list could not be found (doesn't exist in current #request_t).
 *      - -3 if context could not be found (no parent #request_t available).
 *      - -4 on memory allocation error.
 */
int tmpl_copy_pair_children(TALLOC_CTX *ctx, fr_pair_list_t *out, request_t *request, tmpl_t const *vpt)
{
        fr_pair_t               *vp;
        fr_dcursor_t            from;
        tmpl_dcursor_ctx_t      cc;
        int err;
 
        TMPL_VERIFY(vpt);
 
        fr_assert(tmpl_is_attr(vpt));
 
        fr_pair_list_free(out);
 
        for (vp = tmpl_dcursor_init(&err, NULL, &cc, &from, request, vpt);
             vp;
             vp = fr_dcursor_next(&from)) {
                switch (vp->vp_type) {
                case FR_TYPE_STRUCTURAL:
                        if (fr_pair_list_copy(ctx, out, &vp->vp_group) < 0) {
                                err = -4;
                                goto done;
                        }
                        break;
 
                default:
                        continue;
                }
        }
done:
        tmpl_dcursor_clear(&cc);
 
        return err;
}
 
 
/** Returns the first VP matching a #tmpl_t
 *
 * @param[out] out where to write the retrieved vp.
 * @param[in] request The current #request_t.
 * @param[in] vpt specifying the #fr_pair_t type to find.
 *      Must be one of the following types:
 *      - #TMPL_TYPE_ATTR
 * @return
 *      - 0 on success (found matching #fr_pair_t).
 *      - -1 if no matching #fr_pair_t could be found.
 *      - -2 if list could not be found (doesn't exist in current #request_t).
 *      - -3 if context could not be found (no parent #request_t available).
 */
int tmpl_find_vp(fr_pair_t **out, request_t *request, tmpl_t const *vpt)
{
        fr_dcursor_t            cursor;
        tmpl_dcursor_ctx_t      cc;
        fr_pair_t               *vp;
        int                     err;
 
        TMPL_VERIFY(vpt);
 
        vp = tmpl_dcursor_init(&err, request, &cc, &cursor, request, vpt);
        tmpl_dcursor_clear(&cc);
 
        if (out) *out = vp;
 
        return err;
}
 
/** Returns the first VP matching a #tmpl_t, or if no VPs match, creates a new one.
 *
 * @param[out] out where to write the retrieved or created vp.
 * @param[in] request The current #request_t.
 * @param[in] vpt specifying the #fr_pair_t type to retrieve or create.  Must be #TMPL_TYPE_ATTR.
 * @return
 *      - 1 on success a pair was created.
 *      - 0 on success a pair was found.
 *      - -1 if a new #fr_pair_t couldn't be found or created.
 *      - -2 if list could not be found (doesn't exist in current #request_t).
 *      - -3 if context could not be found (no parent #request_t available).
 */
int tmpl_find_or_add_vp(fr_pair_t **out, request_t *request, tmpl_t const *vpt)
{
        fr_dcursor_t            cursor;
        tmpl_dcursor_ctx_t      cc;
        fr_pair_t               *vp;
        int                     err;
 
        TMPL_VERIFY(vpt);
        fr_assert(tmpl_is_attr(vpt));
 
        *out = NULL;
 
        vp = tmpl_dcursor_init(&err, NULL, &cc, &cursor, request, vpt);
        tmpl_dcursor_clear(&cc);
 
        switch (err) {
        case 0:
                *out = vp;
                return 0;
 
        case -1:
        {
                TALLOC_CTX      *ctx;
                fr_pair_list_t  *head;
 
                tmpl_pair_list_and_ctx(ctx, head, request, tmpl_request(vpt), tmpl_list(vpt));
                if (!head) return -1;
 
                if (pair_append_by_tmpl_parent(ctx, &vp, head, vpt, true) < 0) return -1;
 
                PAIR_ALLOCED(vp);
                *out = vp;
        }
                return 1;
 
        default:
                return err;
        }
}
 
/** Allocate and insert a leaf vp from a tmpl_t, building the parent vps if needed.
 *
 * This is the simple case - just add a vp at the first place where
 * the parents exist, or create the parents, with no attempt to handle filters.
 *
 * It is functionally equivalent to fr_pair_append_by_da_parent() but
 * uses a tmpl_t to build the nested structure rather than a fr_dict_attr_t.
 *
 * @param[in] ctx       to allocate new pair(s) in
 * @param[out] out      Leaf pair we allocated.
 * @param[in] list      to insert into.
 * @param[in] vpt       tmpl representing the attribute to add.
 * @param[in] skip_list skip list attr ref at the head of the tmpl.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
int pair_append_by_tmpl_parent(TALLOC_CTX *ctx, fr_pair_t **out, fr_pair_list_t *list, tmpl_t const *vpt, bool skip_list)
{
        fr_pair_t                       *vp = NULL;
        TALLOC_CTX                      *pair_ctx = ctx;
        tmpl_attr_t                     *ar, *leaf;
        tmpl_attr_list_head_t const     *ar_list = &vpt->data.attribute.ar;
 
        if (!tmpl_is_attr(vpt)) {
        error:
                *out = NULL;
                return -1;
        }
 
        leaf = tmpl_attr_list_tail(ar_list);
        ar = tmpl_attr_list_head(ar_list);
        if (!ar) goto error;
        if (skip_list && tmpl_attr_is_list_attr(ar)) ar = tmpl_attr_list_next(ar_list, ar);
 
        /*
         *      Walk down the tmpl ar stack looking for candidate parent
         *      attributes and then allocating the leaf.
         */
        while (true) {
                if (unlikely(!ar)) goto error;
                /*
                 *      We're not at the leaf, look for a potential parent
                 */
                if (ar != leaf) {
                        vp = fr_pair_find_by_da(list, NULL, ar->da);
                }
 
                /*
                 *      Nothing found, create the pair
                 */
                if (!vp) {
                        if (fr_pair_append_by_da(pair_ctx, &vp, list, ar->da) < 0) goto error;
                        PAIR_ALLOCED(vp);
                }
 
                /*
                 *      We're at the leaf, return
                 */
                if (ar == leaf) {
                        *out = vp;
                        return 0;
                }
 
                /*
                 *      Prepare for next level
                 */
                list = &vp->vp_group;
                pair_ctx = vp;
                vp = NULL;
                ar = tmpl_attr_list_next(ar_list, ar);
        }
}
 
/** Insert a value-box to a list, with casting.
 *
 * @param list  to append to
 * @param box   box to cast / append
 * @param vpt   tmpl with cast.
 * @return
 *      - <0 for "cast failed"
 *      - 0 for success
 */
int tmpl_value_list_insert_tail(fr_value_box_list_t *list, fr_value_box_t *box, tmpl_t const *vpt)
{
        if (fr_type_is_null(tmpl_rules_cast(vpt)) ||
            (box->type == tmpl_rules_cast(vpt))) {
                fr_value_box_list_insert_tail(list, box);
                return 0;
        }
 
        if (fr_value_box_cast_in_place(box, box, tmpl_rules_cast(vpt), tmpl_rules_enumv(vpt)) < 0) return -1;
 
        fr_value_box_list_insert_tail(list, box);
        VALUE_BOX_LIST_VERIFY(list);
        return 0;
}
 
/** Gets the value of a real or virtual attribute
 *
 * @param[in] ctx       to allocate boxed value, and buffers in.
 * @param[out] out      Where to write the boxed value.
 * @param[in] request   The current request.
 * @param[in] vpt       Representing the attribute.
 * @return
 *      - <0            we failed getting a value for the attribute.
 *      - 0             we successfully evaluated the tmpl
 */
int tmpl_eval_pair(TALLOC_CTX *ctx, fr_value_box_list_t *out, request_t *request, tmpl_t const *vpt)
{
        fr_pair_t               *vp = NULL;
        fr_value_box_t          *value;
 
        fr_dcursor_t            cursor;
        tmpl_dcursor_ctx_t      cc;
 
        int                     ret = 0;
        fr_value_box_list_t     list;
 
        fr_assert(tmpl_is_attr(vpt));
 
        fr_value_box_list_init(&list);
 
        /*
         *      See if we're dealing with an attribute in the request
         *
         *      This allows users to manipulate virtual attributes as if
         *      they were real ones.
         */
        vp = tmpl_dcursor_init(NULL, NULL, &cc, &cursor, request, vpt);
 
        /*
         *      We didn't find the VP in a list, check to see if it's
         *      virtual.  This allows the caller to "realize" the
         *      attribute, and we then prefer the realized version to
         *      the virtual one.
         */
        if (!vp) {
                /*
                 *      Zero count.
                 */
                if (tmpl_attr_tail_num(vpt) == NUM_COUNT) {
                        value = fr_value_box_alloc(ctx, FR_TYPE_UINT32, NULL);
                        if (!value) {
                        oom:
                                fr_strerror_const("Out of memory");
                                ret = -1;
                                goto fail;
                        }
                        value->datum.uint32 = 0;
                        fr_value_box_list_insert_tail(&list, value);
                } /* Fall through to being done */
 
                goto done;
        }
 
        switch (tmpl_attr_tail_num(vpt)) {
        /*
         *      Return a count of the VPs.
         */
        case NUM_COUNT:
        {
                uint32_t                count = 0;
 
                while (vp != NULL) {
                        count++;
                        vp = fr_dcursor_next(&cursor);
                }
 
                value = fr_value_box_alloc(ctx, FR_TYPE_UINT32, NULL);
                if (!value) goto oom;
                value->datum.uint32 = count;
                fr_value_box_list_insert_tail(&list, value);
                break;
        }
 
        /*
         *      Output multiple #value_box_t, one per attribute.
         */
        case NUM_ALL:
                /*
                 *      Loop over all matching #fr_value_pair
                 *      shallow copying buffers.
                 */
                while (vp != NULL) {
                        if (fr_type_is_structural(vp->vp_type)) {
                                value = fr_value_box_alloc(ctx, FR_TYPE_GROUP, NULL);
                                if (!value) goto oom;
 
                                if (fr_pair_list_copy_to_box(value, &vp->vp_group) < 0) {
                                        talloc_free(value);
                                        goto oom;
                                }
 
                        } else {
                                value = fr_value_box_alloc(ctx, vp->data.type, vp->da);
                                if (!value) goto oom;
                                if(unlikely(fr_value_box_copy(value, value, &vp->data) < 0)) {
                                        talloc_free(value);
                                        goto fail;
                                }
                        }
 
                        fr_value_box_list_insert_tail(&list, value);
                        vp = fr_dcursor_next(&cursor);
                }
                break;
 
        default:
                if (!fr_type_is_leaf(vp->vp_type)) {
                        fr_strerror_const("Invalid data type for evaluation");
                        goto fail;
                }
 
                value = fr_value_box_alloc(ctx, vp->data.type, vp->da);
                if (!value) goto oom;
 
                if (unlikely(fr_value_box_copy(value, value, &vp->data) < 0)) {
                        talloc_free(value);
                        goto fail;
                }
                fr_value_box_list_insert_tail(&list, value);
                break;
        }
 
done:
        /*
         *      Evaluate casts if necessary.
         */
        if (ret == 0) {
                if (tmpl_eval_cast_in_place(&list, request, vpt) < 0) {
                        fr_value_box_list_talloc_free(&list);
                        ret = -1;
                        goto fail;
                }
 
                fr_value_box_list_move(out, &list);
        }
 
fail:
        tmpl_dcursor_clear(&cc);
        VALUE_BOX_LIST_VERIFY(out);
        return ret;
}
 
 
/** Gets the value of a tmpl
 *
 *  The result is returned "raw".  The caller must do any escaping it desires.
 *
 * @param[in] ctx       to allocate boxed value, and buffers in.
 * @param[out] out      Where to write the boxed value.
 * @param[in] request   The current request.
 * @param[in] vpt       Representing the tmpl
 * @return
 *      - <0            we failed getting a value for the tmpl
 *      - 0             we successfully evaluated the tmpl
 */
int tmpl_eval(TALLOC_CTX *ctx, fr_value_box_list_t *out, request_t *request, tmpl_t const *vpt)
{
        char *p;
        fr_value_box_t          *value;
        fr_value_box_list_t     list;
 
        if (tmpl_needs_resolving(vpt)) {
                fr_strerror_const("Cannot evaluate unresolved tmpl");
                return -1;
        }
 
        if (tmpl_async_required(vpt)) {
                fr_strerror_const("Cannot statically evaluate asynchronous expansions");
                return -1;
        }
 
        if (tmpl_contains_regex(vpt)) {
                fr_strerror_const("Cannot statically evaluate regular expression");
                return -1;
        }
 
        if (tmpl_is_attr(vpt)) {
                return tmpl_eval_pair(ctx, out, request, vpt);
        }
 
        if (tmpl_is_data(vpt)) {
                MEM(value = fr_value_box_alloc(ctx, tmpl_value_type(vpt), NULL));
 
                if (unlikely(fr_value_box_copy(value, value, tmpl_value(vpt)) < 0)) {
                        talloc_free(value);
                        return -1;      /* Also dups taint */
                }
                goto done;
        }
 
        fr_assert(tmpl_is_xlat(vpt));
 
        /*
         *      @todo - respect escaping functions.  But the sync
         *      escaping uses a different method than the async ones.
         *      And we then also need to escape the output of
         *      tmpl_eval_pair(), too.
         */
        MEM(value = fr_value_box_alloc_null(ctx));
        if (tmpl_aexpand(value, &p, request, vpt, NULL, NULL) < 0) {
                talloc_free(value);
                return -1;
        }
        fr_value_box_bstrndup_shallow(value, NULL, p, talloc_strlen(p), true);
 
        /*
         *      Cast the results if necessary.
         */
done:
        fr_value_box_list_init(&list);
        fr_value_box_list_insert_tail(&list, value);
 
        if (tmpl_eval_cast_in_place(&list, request, vpt) < 0) {
                fr_value_box_list_talloc_free(&list);
                return -1;
        }
 
        fr_value_box_list_move(out, &list);
        VALUE_BOX_LIST_VERIFY(out);
 
        return 0;
}
 
/** Allocate a uctx for an escaping function
 *
 * @param[in] request   The current request.
 * @param[in] escape    Describing how to escape tmpl data.
 *
 * @return the uctx to pass to the escape function.
 */
static inline void *tmpl_eval_escape_uctx_alloc(request_t *request, tmpl_escape_t const *escape)
{
        switch (escape->uctx.type) {
        case TMPL_ESCAPE_UCTX_STATIC:
                return UNCONST(void *, escape->uctx.ptr);
 
        case TMPL_ESCAPE_UCTX_ALLOC:
        {
                void *uctx;
 
                fr_assert_msg(escape->uctx.size > 0, "TMPL_ESCAPE_UCTX_ALLOC must specify uctx.size > 0");
                MEM(uctx = talloc_zero_array(NULL, uint8_t, escape->uctx.size));
                if (escape->uctx.talloc_type) talloc_set_type(uctx, escape->uctx.talloc_type);
                return uctx;
        }
 
        case TMPL_ESCAPE_UCTX_ALLOC_FUNC:
                fr_assert_msg(escape->uctx.func.alloc, "TMPL_ESCAPE_UCTX_ALLOC_FUNC must specify a non-null alloc.func");
                return escape->uctx.func.alloc(request, escape->uctx.func.uctx);
 
        default:
                fr_assert_msg(0, "Unknown escape uctx type %u", escape->uctx.type);
                return NULL;
        }
}
 
/** Free a uctx for an escaping function
 *
 * @param[in] escape    Describing how to escape tmpl data.
 * @param[in] uctx      The uctx to free.
 */
static inline void tmpl_eval_escape_uctx_free(tmpl_escape_t const *escape, void *uctx)
{
        switch (escape->uctx.type) {
        case TMPL_ESCAPE_UCTX_STATIC:
                return;
 
        case TMPL_ESCAPE_UCTX_ALLOC:
                talloc_free(uctx);
                return;
 
        case TMPL_ESCAPE_UCTX_ALLOC_FUNC:
                if (escape->uctx.func.free) escape->uctx.func.free(uctx);
                return;
        }
}
 
/** Casts a value or list of values according to the tmpl
 *
 * @param[in,out] list  Where to write the boxed value.
 * @param[in] request   The current request.
 * @param[in] vpt       Representing the attribute.
 * @return
 *      - <0            the cast failed
 *      - 0             we successfully evaluated the tmpl
 */
int tmpl_eval_cast_in_place(fr_value_box_list_t *list, request_t *request, tmpl_t const *vpt)
{
        fr_type_t cast = tmpl_rules_cast(vpt);
        bool did_concat = false;
        void *uctx = NULL;
 
        if (fr_type_is_structural(cast)) {
                fr_strerror_printf("Cannot cast to structural type '%s'", fr_type_to_str(cast));
                return -1;
        }
 
        /*
         *      Quoting around the tmpl means everything
         *      needs to be concatenated, either as a string
         *      or octets string.
         */
        switch (vpt->quote) {
        case T_DOUBLE_QUOTED_STRING:
        case T_SINGLE_QUOTED_STRING:
        case T_SOLIDUS_QUOTED_STRING:
        case T_BACK_QUOTED_STRING:
        {
                ssize_t         slen;
                fr_value_box_t  *vb;
 
                vb = fr_value_box_list_head(list);
                if (!vb) return 0;
 
                if (tmpl_escape_pre_concat(vpt)) {
                        uctx = tmpl_eval_escape_uctx_alloc(request, &vpt->rules.escape);
 
                        /*
                         *      Sets escaped values, so boxes don't get re-escaped
                         */
                        if (unlikely(fr_value_box_list_escape_in_place(list, &vpt->rules.escape.box_escape, uctx) < 0)) {
                        error:
                                tmpl_eval_escape_uctx_free(&vpt->rules.escape, uctx);
                                return -1;
                        }
                }
 
                slen = fr_value_box_list_concat_in_place(vb, vb, list, FR_TYPE_STRING,
                                                         FR_VALUE_BOX_LIST_FREE_BOX, true, SIZE_MAX);
                if (slen < 0) goto error;
                VALUE_BOX_LIST_VERIFY(list);
 
                /*
                 *      If there's no cast, or it's a cast to
                 *      a string, we're done!
                 *
                 *      Otherwise we now need to re-cast the
                 *      result.
                 */
                if (fr_type_is_null(cast) || fr_type_is_string(cast)) {
                success:
                        tmpl_eval_escape_uctx_free(&vpt->rules.escape, uctx);
                        return 0;
                }
 
                did_concat = true;
        }
                break;
 
        default:
                break;
        }
 
        if (fr_type_is_null(cast)) goto success;
 
        /*
         *      Quoting above handled all concatenation,
         *      we now need to handle potentially
         *      multivalued lists.
         */
        fr_value_box_list_foreach(list, vb) {
                if (fr_value_box_cast_in_place(vb, vb, cast, NULL) < 0) goto error;
        }
 
        /*
         *      ...and finally, apply the escape function
         *      if necessary.  This is done last so that
         *      the escape function gets boxes of the type
         *      it expects.
         */
        if ((!did_concat && tmpl_escape_pre_concat(vpt)) || tmpl_escape_post_concat(vpt)) {
                if (!uctx) uctx = tmpl_eval_escape_uctx_alloc(request, &vpt->rules.escape);
                if (unlikely(fr_value_box_list_escape_in_place(list, &vpt->rules.escape.box_escape, uctx) < 0)) goto error;
        }
 
        /*
         *      If there's no escape function, but there is
         *      a safe_for value, mark all the boxes up with
         *      this value.
         *
         *      This is mostly useful for call_env usage in
         *      modules where certain values are implicitly safe
         *      for consumption, like SQL statements in the SQL
         *      module.
         */
        if (!vpt->rules.escape.box_escape.func && vpt->rules.escape.box_escape.safe_for) {
                fr_value_box_list_mark_safe_for(list, vpt->rules.escape.box_escape.safe_for);
        }
 
        VALUE_BOX_LIST_VERIFY(list);
 
        goto success;
}
 
fr_type_t tmpl_data_type(tmpl_t const *vpt)
{
        if (tmpl_rules_cast(vpt) != FR_TYPE_NULL) return tmpl_rules_cast(vpt);
 
        if (vpt->quote != T_BARE_WORD) return FR_TYPE_STRING;
 
        if (tmpl_is_data(vpt)) return tmpl_value_type(vpt);
 
        if (tmpl_is_attr(vpt)) return tmpl_attr_tail_da(vpt)->type;
 
        if (tmpl_is_xlat(vpt)) return xlat_data_type(tmpl_xlat(vpt));
 
        return FR_TYPE_NULL;    /* can't determine it */
}
 
 
static int _tmpl_global_free(UNUSED void *uctx)
{
        fr_dict_autofree(tmpl_dict);
 
        return 0;
}
 
static int _tmpl_global_init(UNUSED void *uctx)
{
        fr_dict_attr_t *da;
 
        if (fr_dict_autoload(tmpl_dict) < 0) {
                PERROR("%s", __FUNCTION__);
                return -1;
        }
 
        da = fr_dict_attr_unknown_raw_afrom_num(UNCONST(TALLOC_CTX *, dict_freeradius), fr_dict_root(dict_freeradius), 0);
        fr_assert(da != NULL);
 
        da->type = FR_TYPE_NULL;
        tmpl_attr_unspec = da;
 
        return 0;
}
 
int tmpl_global_init(void)
{
        int ret;
 
        fr_atexit_global_once_ret(&ret, _tmpl_global_init, _tmpl_global_free, NULL);
 
        return ret;
}