core: xavp - helper function to serialize subfields in a params list

src/core/xavp.c

@@ -843,4 +843,65 @@ sr_xavp_t* xavp_get_child_with_sval(str *rname, str *cname)
 
 	return vavp;
 }
+
+
+/**
+ * serialize the values in subfields of an xavp in name=value; format
+ * - rname - name of the root list xavp
+ * - obuf - buffer were to write the output
+ * - olen - the size of obuf
+ * return: 0 - not found; -1 - error; >0 - length of output
+ */
+
+int xavp_serialize_fields(str *rname, char *obuf, int olen)
+{
+	sr_xavp_t *ravp = NULL;
+	sr_xavp_t *avp = NULL;
+	str ostr;
+	int rlen;
+
+	ravp = xavp_get(rname, NULL);
+	if(ravp==NULL || ravp->val.type!=SR_XTYPE_XAVP) {
+		/* not found or not holding subfields */
+		return 0;
+	}
+
+	rlen = 0;
+	ostr.s = obuf;
+	avp = ravp->val.v.xavp;
+	while(avp) {
+		switch(avp->val.type) {
+			case SR_XTYPE_INT:
+				LM_DBG("     XAVP int value: %d\n", avp->val.v.i);
+				ostr.len = snprintf(ostr.s, olen-rlen, "%.*s=%u;",
+						avp->name.len, avp->name.s, (unsigned int)avp->val.v.i);
+				if(ostr.len<=0 || ostr.len>=olen-rlen) {
+					LM_ERR("failed to serialize int value (%d/%d\n",
+							ostr.len, olen-rlen);
+					return -1;
+				}
+			break;
+			case SR_XTYPE_STR:
+				LM_DBG("     XAVP str value: %s\n", avp->val.v.s.s);
+				ostr.len = snprintf(ostr.s, olen-rlen, "%.*s=%.*s;",
+						avp->name.len, avp->name.s,
+						avp->val.v.s.len, avp->val.v.s.s);
+				if(ostr.len<=0 || ostr.len>=olen-rlen) {
+					LM_ERR("failed to serialize int value (%d/%d\n",
+							ostr.len, olen-rlen);
+					return -1;
+				}
+			break;
+			default:
+				LM_DBG("skipping value type: %d\n", avp->val.type);
+				ostr.len = 0;
+		}
+		if(ostr.len>0) {
+			ostr.s += ostr.len;
+			rlen += ostr.len;
+		}
+		avp = avp->next;
+	}
+	return rlen;
+}
 #endif

src/core/xavp.h

@@ -101,6 +101,8 @@ sr_xavp_t *xavp_clone_level_nodata(sr_xavp_t *xold);
 sr_xavp_t* xavp_get_child(str *rname, str *cname);
 sr_xavp_t* xavp_get_child_with_ival(str *rname, str *cname);
 sr_xavp_t* xavp_get_child_with_sval(str *rname, str *cname);
+int xavp_serialize_fields(str *rname, char *obuf, int olen);
+
 #endif
 
 #endif