for-each statement: Add support for $json iterators

Example way of usage:
    for ($json(foo) in $(avp(bar)[*]))
        xlog("JSON fields: $json(foo/baz) $json(foo/qux)\n");

action.c

@@ -2069,12 +2069,14 @@ int do_action(struct action* a, struct sip_msg* msg)
 
 static int for_each_handler(struct sip_msg *msg, struct action *a)
 {
-	pv_spec_p spec;
+	pv_spec_p iter, spec;
 	pv_param_t pvp;
 	pv_value_t val;
 	int ret = 1;
+	int op = 0;
 
 	if (a->elem[2].type == ACTIONS_ST && a->elem[2].u.data) {
+		iter = a->elem[0].u.data;
 		spec = a->elem[1].u.data;
 
 		/*
@@ -2090,6 +2092,14 @@ static int for_each_handler(struct sip_msg *msg, struct action *a)
 		pvp.pvi.type = PV_IDX_INT;
 		pvp.pvn = spec->pvp.pvn;
 
+		/*
+		 * for $json iterators, better to assume script writer
+		 * wants data to be interpreted, rather than not
+		 *    (i.e. ":=" script operator, and not simply "=")
+		 */
+		if (iter->type == PVT_JSON)
+			op = COLONEQ_T;
+
 		for (;;) {
 			if (spec->getf(msg, &pvp, &val) != 0) {
 				LM_ERR("failed to get spec value\n");
@@ -2099,9 +2109,7 @@ static int for_each_handler(struct sip_msg *msg, struct action *a)
 			if (val.flags & PV_VAL_NULL)
 				break;
 
-			if (((pv_spec_p)a->elem[0].u.data)->
-					setf(msg, &((pv_spec_p)a->elem[0].u.data)->pvp,
-			             0, &val) != 0) {
+			if (iter->setf(msg, &iter->pvp, op, &val) != 0) {
 				LM_ERR("failed to set scriptvar value\n");
 				return E_BUG;
 			}

cfg.y

@@ -1723,9 +1723,10 @@ while_cmd:		WHILE exp stm				{ mk_action2( $$, WHILE_T,
 
 foreach_cmd:	FOR LPAREN script_var IN script_var RPAREN stm {
 					if ($3->type != PVT_SCRIPTVAR &&
-					    $3->type != PVT_AVP) {
-						yyerror("\nfor-each statement: only \"var\" "
-					            "and \"avp\" iterators are supported");
+					    $3->type != PVT_AVP &&
+						$3->type != PVT_JSON) {
+						yyerror("\nfor-each statement: only \"var\", \"avp\" "
+					            "and \"json\" iterators are supported!");
 					}
 
 					mk_action3( $$, FOR_EACH_T,

modules/json/json.c

@@ -49,10 +49,6 @@
 #include <json_object_private.h>
 
 
-
-
-
-#define PV_JSON_ID  8888
 #define JSON_BUFF_SIZE 4096
 
 enum
@@ -126,7 +122,7 @@ static cmd_export_t cmds[]={
 
 
 static pv_export_t mod_items[] = {
-	{ {"json",  sizeof("json")-1},    PV_JSON_ID, pv_get_json,
+	{ {"json",  sizeof("json")-1},    PVT_JSON, pv_get_json,
 		pv_set_json, pv_parse_json_name, 0, 0, 0},
 	{ {0, 0}, 0, 0, 0, 0, 0, 0, 0 }
 };
@@ -212,7 +208,7 @@ int fixup_json_bind(void** param, int param_no)
 			return -1;
 		}
 
-		if( var->type != PV_JSON_ID )
+		if( var->type != PVT_JSON )
 		{
 			LM_ERR("Parameter no: %d must be a json variable\n",param_no);
 			return -1;
@@ -955,7 +951,7 @@ int pv_parse_json_name (pv_spec_p sp, str *in)
 
 
 	sp->pvp.pvn.u.dname = id ;
-	sp->type = PV_JSON_ID;
+	sp->type = PVT_JSON;
 	sp->getf = pv_get_json;
 	sp->setf = pv_set_json;
 

pvar.h

@@ -108,6 +108,10 @@ enum _pv_type {
 	PVT_HDRCNT,           PVT_AUTH_NONCE_COUNT,  PVT_AUTH_QOP,
 	PVT_AUTH_ALGORITHM,   PVT_AUTH_OPAQUE,       PVT_AUTH_CNONCE,
 	PVT_RU_Q,             PVT_ROUTE_PARAM,       PVT_ROUTE_TYPE,
+
+	/* registered by json module */
+	PVT_JSON,
+
 	PVT_EXTRA /* keep it last */
 };