jpath.c File Reference

Implements the evaluation and parsing functions for the FreeRADIUS version of jpath. More...

#include <freeradius-devel/util/debug.h>
#include "base.h"

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Data Structures
struct	fr_jpath_node
	Node in a jpath selector sequence. More...
struct	jpath_expr_t
	A jpath expression for performing complex comparisons against field values. More...
union	jpath_operand_t
	Operand in a jpath expression. More...
struct	jpath_selector
union	jpath_selector.__unnamed39__

Macros
#define	NODE_NEW(_node)
#define	SELECTOR_INDEX_UNSET   INT32_MAX

Typedefs
typedef struct jpath_selector	jpath_selector_t
	Selects a subset of JSON child nodes. More...

Enumerations
enum	jpath_operand_type {   JPATH_OPERAND_LITERAL = 0 ,   JPATH_OPERAND_JPATH }
enum	jpath_type_t {   JPATH_SELECTOR_INVALID = 0 ,   JPATH_SELECTOR_ROOT ,   JPATH_SELECTOR_CURRENT ,   JPATH_SELECTOR_WILDCARD ,   JPATH_SELECTOR_FIELD ,   JPATH_SELECTOR_INDEX ,   JPATH_SELECTOR_SLICE ,   JPATH_SELECTOR_FILTER_EXPRESSION ,   JPATH_SELECTOR_EXPRESSION ,   JPATH_SELECTOR_RECURSIVE_DESCENT }

Functions
char *	fr_jpath_asprint (TALLOC_CTX *ctx, fr_jpath_node_t const *head)
	Print a node list to a string for debugging. More...
ssize_t	fr_jpath_escape_func (UNUSED request_t *request, char *out, size_t outlen, char const *in, UNUSED void *arg)
	Escapes special chars. More...
int	fr_jpath_evaluate_leaf (TALLOC_CTX *ctx, fr_value_box_list_t *out, fr_type_t dst_type, fr_dict_attr_t const *dst_enumv, json_object *root, fr_jpath_node_t const *jpath)
	Evaluate a parsed jpath expression against a json-c tree. More...
ssize_t	fr_jpath_parse (TALLOC_CTX *ctx, fr_jpath_node_t **head, char const *in, size_t inlen)
	Parse a jpath string. More...
static ssize_t	jpath_array_parse (jpath_selector_t *selector, char const *in, size_t inlen)
	Parse index/slice notation. More...
static int	jpath_evaluate (TALLOC_CTX *ctx, fr_value_box_list_t *tail, fr_type_t dst_type, fr_dict_attr_t const *dst_enumv, json_object *object, fr_jpath_node_t const *jpath)
	Recursive function for jpath_expr_evaluate. More...
static ssize_t	jpath_expr_parse (UNUSED jpath_selector_t *selector, UNUSED char const *in, UNUSED size_t inlen)
	Parse a jpath expression. More...
static size_t	jpath_field_parse (fr_jpath_node_t *node, char const *in, size_t inlen)
	Parse a jpath field. More...
static ssize_t	jpath_filter_expr_parse (UNUSED jpath_selector_t *selector, UNUSED char const *in, UNUSED size_t inlen)
	Parse a jpath filter expression, which in our case, is a FreeRADIUS condition. More...
static size_t	jpath_selector_parse (fr_jpath_node_t *node, char const *in, size_t inlen)
	parse a jpath selector More...

Variables
static char const	escape_chars [] = "[],*.:()?"

Detailed Description

Implements the evaluation and parsing functions for the FreeRADIUS version of jpath.

Id

a69f0df3752c77e8952ce2c514a98ecfc5961a4d

Author

Arran Cudbard-Bell

Copyright

2015 Arran Cudbard-Bell (a.cud.nosp@m.bard.nosp@m.b@fre.nosp@m.erad.nosp@m.ius.o.nosp@m.rg)

2015 Network RADIUS SAS (legal.nosp@m.@net.nosp@m.workr.nosp@m.adiu.nosp@m.s.com)

2015 The FreeRADIUS Server Project

Definition in file jpath.c.

---

Data Structure Documentation

fr_jpath_node

struct fr_jpath_node

Node in a jpath selector sequence.

Definition at line 87 of file jpath.c.

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Data Fields
fr_jpath_node_t *	next	Next in the jpath chain.
jpath_selector_t *	selector	Jpath selector head (there may be multiple).

jpath_expr_t

struct jpath_expr_t

A jpath expression for performing complex comparisons against field values.

Definition at line 63 of file jpath.c.

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Data Fields
jpath_operand_t	lhs	LHS value.
jpath_operand_t	rhs	RHS value.

jpath_operand_t

union jpath_operand_t

Operand in a jpath expression.

Definition at line 55 of file jpath.c.

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Data Fields
fr_jpath_node_t *	jpath	Operand is a jpath expression.
char const *	literal	Operand is a literal (value)

jpath_selector

struct jpath_selector

Definition at line 73 of file jpath.c.

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Data Fields
union jpath_selector	__unnamed__
jpath_selector_t *	next
jpath_type_t	type	Type of the Jpath node.

jpath_selector.__unnamed39__

union jpath_selector.__unnamed39__

Definition at line 74 of file jpath.c.

Data Fields
jpath_expr_t	expr	Expression.
char const *	field	JSON object name.
int32_t	slice[3]	Array index, or slice, or step.

Macro Definition Documentation

NODE_NEW

#define NODE_NEW

(

_node

)

Value:

do { \
        tail_ctx = *tail = (_node) = talloc_zero(tail_ctx, fr_jpath_node_t); \
        (_node)->selector = talloc_zero((_node), jpath_selector_t); \
        tail = &(_node)->next; \
} while (0)

SELECTOR_INDEX_UNSET

#define SELECTOR_INDEX_UNSET   INT32_MAX

Definition at line 31 of file jpath.c.

Typedef Documentation

jpath_selector_t

typedef struct jpath_selector jpath_selector_t

Selects a subset of JSON child nodes.

Definition at line 1 of file jpath.c.

Enumeration Type Documentation

jpath_operand_type

enum jpath_operand_type

Enumerator
JPATH_OPERAND_LITERAL	Operand is a literal.
JPATH_OPERAND_JPATH	Operand is a jpath sequence.

Definition at line 33 of file jpath.c.

jpath_type_t

enum jpath_type_t

Enumerator
JPATH_SELECTOR_INVALID
JPATH_SELECTOR_ROOT	Jump to the root of the document.
JPATH_SELECTOR_CURRENT	Continue at the current node in the document.
JPATH_SELECTOR_WILDCARD	Wildcard, operate over all array indices, or fields.
JPATH_SELECTOR_FIELD	A field, current JSON node must be an object.
JPATH_SELECTOR_INDEX	Array index, current JSON node must be an array.
JPATH_SELECTOR_SLICE	Array slice, current JSON node must be an array.
JPATH_SELECTOR_FILTER_EXPRESSION	Complex filter expression (NYI).
JPATH_SELECTOR_EXPRESSION	Expression (NYI).
JPATH_SELECTOR_RECURSIVE_DESCENT	Descend through the JSON tree, looking for a node which matches the next one in the jpath sequence.

Definition at line 38 of file jpath.c.

Function Documentation

fr_jpath_asprint()

char* fr_jpath_asprint	(	TALLOC_CTX *	ctx,
		fr_jpath_node_t const *	head
	)

Print a node list to a string for debugging.

Will not be identical to the original parsed string, but should be sufficient for testing purposes.

Parameters

ctx	to allocate string in.
head	of the node list.

Returns

the string representation of the node list.

Definition at line 411 of file jpath.c.

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fr_jpath_escape_func()

ssize_t fr_jpath_escape_func	(	UNUSED request_t *	request,
		char *	out,
		size_t	outlen,
		char const *	in,
		UNUSED void *	arg
	)

Escapes special chars.

Escapes any characters that may have special meaning within a jpath expression

Parameters

request	Current request (unused may be NULL).
out	Where to write the escaped string.
outlen	Length of the output buffer.
in	data to escape.
arg	uctx data, not used.

Returns

the number of chars written to out.

Definition at line 106 of file jpath.c.

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fr_jpath_evaluate_leaf()

int fr_jpath_evaluate_leaf	(	TALLOC_CTX *	ctx,
		fr_value_box_list_t *	out,
		fr_type_t	dst_type,
		fr_dict_attr_t const *	dst_enumv,
		json_object *	root,
		fr_jpath_node_t const *	jpath
	)

Evaluate a parsed jpath expression against a json-c tree.

Will produce one or more fr_value_box_t structures of the desired type, or error out if the conversion between types fails.

Parameters

[in,out]	ctx	to allocate fr_value_box_t in.
[out]	out	Where to write fr_value_box_t.
[in]	dst_type	FreeRADIUS type to convert to.
[in]	dst_enumv	Enumeration values to allow string to integer conversions.
[in]	root	of the json-c tree.
[in]	jpath	to evaluate.

Returns

• 1 on match.
• 0 on no match.
• -1 on error.

Definition at line 383 of file jpath.c.

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fr_jpath_parse()

ssize_t fr_jpath_parse	(	TALLOC_CTX *	ctx,
		fr_jpath_node_t **	head,
		char const *	in,
		size_t	inlen
	)

Parse a jpath string.

Based on the syntax described here http://goessner.net/articles/JsonPath/

Implements parser for everything except unions and expressions

Returns

• > 0 on success.
• <= 0 on error (* -1 to get offset error occurred at).

Definition at line 813 of file jpath.c.

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jpath_array_parse()

static ssize_t jpath_array_parse ( jpath_selector_t *  selector, char const *  in, size_t  inlen  )

static

Parse index/slice notation.

Expects in to point to a buffer containing:

        [<int0>:<int1>:<int2>]

Where each of the integers and its accompanying delimiter is optional.

Parameters

selector	to populate with index/slice info.
in	input.
inlen	length of in.

Returns

• > 0 on success.
• <= 0 on error (* -1 to get offset error occurred at).

Definition at line 544 of file jpath.c.

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jpath_evaluate()

static int jpath_evaluate ( TALLOC_CTX *  ctx, fr_value_box_list_t *  tail, fr_type_t  dst_type, fr_dict_attr_t const *  dst_enumv, json_object *  object, fr_jpath_node_t const *  jpath  )

static

Recursive function for jpath_expr_evaluate.

Parameters

[in,out]	ctx	to allocate fr_value_box_t in.
[out]	tail	Where to write fr_value_box_t.
[in]	dst_type	FreeRADIUS type to convert to.
[in]	dst_enumv	Enumeration values to allow string to integer conversions.
[in]	object	current node in the json tree.
[in]	jpath	to evaluate.

Returns

• 1 on match.
• 0 on no match.
• -1 on error.

Definition at line 141 of file jpath.c.

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jpath_expr_parse()

static ssize_t jpath_expr_parse ( UNUSED jpath_selector_t *  selector, UNUSED char const *  in, UNUSED size_t  inlen  )

static

Parse a jpath expression.

Note

this requires reworking some of the condition code to accept callbacks to retrieve virtual attributes, so is not yet implemented.

Definition at line 519 of file jpath.c.

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jpath_field_parse()

static size_t jpath_field_parse ( fr_jpath_node_t *  node, char const *  in, size_t  inlen  )

static

Parse a jpath field.

Definition at line 652 of file jpath.c.

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jpath_filter_expr_parse()

static ssize_t jpath_filter_expr_parse ( UNUSED jpath_selector_t *  selector, UNUSED char const *  in, UNUSED size_t  inlen  )

static

Parse a jpath filter expression, which in our case, is a FreeRADIUS condition.

Note

this requires reworking some of the condition code to accept callbacks to retrieve virtual attributes, so is not yet implemented.

Definition at line 506 of file jpath.c.

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jpath_selector_parse()

static size_t jpath_selector_parse ( fr_jpath_node_t *  node, char const *  in, size_t  inlen  )

static

parse a jpath selector

Definition at line 730 of file jpath.c.

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Variable Documentation

escape_chars

char const escape_chars[] = "[],*.:()?"

static

Definition at line 92 of file jpath.c.