Convert _str() from inline to a macro and make it return

(const str *), not (str *). This is to limit potential
damage from its (mis)use in non-testing modules code by
first making its value stored locally at point of use
(which should allow compiler to throw it away when used
properly) and also provide at least some protection from
any function from messing with its fields.

Fix any fallout where str * has been passed around.

Author: sobomax

modules/dialog/dlg_handlers.c

@@ -2707,8 +2707,8 @@ int dlg_validate_dialog( struct sip_msg* req, struct dlg_cell *dlg)
 	return 0;
 }
 
-int terminate_dlg(str *callid, unsigned int h_entry, unsigned int h_id,
-	str *reason)
+int terminate_dlg(const str *callid, unsigned int h_entry, unsigned int h_id,
+	const str *reason)
 {
 	struct dlg_cell * dlg = NULL;
 	int ret = 0;

modules/dialog/dlg_handlers.h

@@ -101,8 +101,8 @@ typedef int (*validate_dialog_f) (struct sip_msg* req, struct dlg_cell *dlg);
 typedef int (*fix_route_dialog_f) (struct sip_msg *req,struct dlg_cell *dlg);
 /* the dialog is identified by callid if provided,
  * otherwise by h_entry and h_id */
-typedef int (*terminate_dlg_f)(str *callid, unsigned int h_entry,
-		unsigned int h_id, str *reason);
+typedef int (*terminate_dlg_f)(const str *callid, unsigned int h_entry,
+		unsigned int h_id, const str *reason);
 typedef int (*indialog_reply_f) (struct sip_msg *msg, int statuscode,
 		void *param);
 typedef int (*send_indialog_req_f)(struct dlg_cell *dlg, str *method,
@@ -128,8 +128,8 @@ int dlg_validate_dialog( struct sip_msg* req, struct dlg_cell *dlg);
 
 int fix_route_dialog(struct sip_msg *req,struct dlg_cell *dlg);
 
-int terminate_dlg(str *callid, unsigned int h_entry, unsigned int h_id,
-		str *reason);
+int terminate_dlg(const str *callid, unsigned int h_entry, unsigned int h_id,
+		const str *reason);
 
 int send_indialog_request(struct dlg_cell *dlg, str *method,
 		int leg, str *body, str *ct, str *hdrs, indialog_reply_f func,

modules/dialog/dlg_hash.c

@@ -867,7 +867,7 @@ struct dlg_cell* get_dlg_by_val(str *attr, str *val)
 }
 
 
-struct dlg_cell* get_dlg_by_callid( str *callid, int active_only)
+struct dlg_cell* get_dlg_by_callid(const str *callid, int active_only)
 {
 	struct dlg_cell *dlg;
 	struct dlg_entry *d_entry;

modules/dialog/dlg_hash.h

@@ -397,7 +397,7 @@ struct dlg_cell* get_dlg(str *callid, str *ftag, str *ttag,
 
 struct dlg_cell* get_dlg_by_val(str *attr, str *val);
 
-struct dlg_cell* get_dlg_by_callid( str *callid, int active_only);
+struct dlg_cell* get_dlg_by_callid(const str *callid, int active_only);
 
 struct dlg_cell* get_dlg_by_did(str *did, int active_only);
 

modules/dialog/dlg_load.h

@@ -31,7 +31,7 @@
 
 typedef struct dlg_cell *(*get_dlg_f) (void);
 typedef str *(*get_dlg_did_f) (struct dlg_cell *dlg);
-typedef struct dlg_cell *(*get_dlg_by_callid_f) (str *, int);
+typedef struct dlg_cell *(*get_dlg_by_callid_f) (const str *, int);
 typedef struct dlg_cell *(*get_dlg_by_did_f) (str *, int);
 typedef int (*match_dialog_f) (struct sip_msg *msg, int _seq_match_mode);
 typedef int (*get_direction_f) (void);

modules/dialplan/dialplan.c

@@ -172,7 +172,7 @@ struct module_exports exports= {
 
 
 /*Inserts table_name/db url into the list of heads*/
-static int dp_head_insert(int dp_insert_type, str *content,
+static int dp_head_insert(int dp_insert_type, const str *content,
 				 str *partition)
 {
 #define h_insert(type, url_str, table_str, ins_str )    \

str.h

@@ -97,16 +97,17 @@ static inline str *str_cpy(str *dest, const str *src)
 /**
  * Handy function for writing unit tests which compare str's
  *
- * WARNING: _only_ use when passing (str *) to _basic_ functions,
- *          since it is not re-entrant and may cause ugly bugs!
+ * WARNING: _only_ use when passing (const str *) to _basic_
+ *          functions, since while poiter is stable for the
+ *          lifetime of the application its value is mutable
+ *          and bad code messing it around may cause ugly bugs!
  */
-static inline str *_str(const char *s)
-{
-	static str st;
-
-	init_str(&st, s);
-	return &st;
-}
+#define _str(s) ( \
+{ \
+	static str _st; \
+	init_str(&_st, s); \
+	/* return */ (const str *)&_st; \
+})
 
 /**
  * Initialize private static str_const given the static buffer