tm: CANCEL reason header on/off switches

Config support (both runtime and modparam) for turning on/off
Reason header support in locally generated or end-to-end
hop-by-hop CANCELs:
- local_cancel_reason =  0|1. Default 1 (on).
- e2e_cancel_reason= 0|1. (Default 1 (on).

End-to-end CANCEL reason header copy can also be turned on/off on
a per transaction basis: t_set_no_e2e_cancel_reason(0|1).
E.g.:
	t_set_no_e2e_cancel_reason(1); # disable reason copy
	t_relay();

t_set_no_e2e_cancel_reason(0) can be used to enable reason header
on a per transaction basis, if the default is disabled
(e2e_cancel_reason is set to 0).

modules/tm/config.c

@@ -24,10 +24,9 @@
  *  2008-02-05	adapting tm module for the configuration framework (Miklos)
  */
 
-/*!
- * \file 
- * \brief TM :: Configuration
- * \ingroup tm
+/** TM :: Runtime configuration variables.
+ * @file
+ * @ingroup tm
  */
 
 
@@ -94,7 +93,11 @@ struct cfg_group_tm	default_tm_cfg = {
 	1,	/* cancel_b_method used for e2e and 6xx cancels*/
 	1,	/* reparse_on_dns_failover */
 	0, /* disable_6xx, by default off */
-	0  /* local_ack_mode, default 0 (rfc3261 conformant) */
+	0,  /* local_ack_mode, default 0 (rfc3261 conformant) */
+	1, /* local_cancel_reason -- add Reason header to locally generated
+		  CANCELs; on by default */
+	1  /* e2e_cancel_reason -- copy the Reason headers from incoming CANCELs
+		  into the corresp. hop-by-hop CANCELs, on by default */
 };
 
 void	*tm_cfg = &default_tm_cfg;
@@ -196,5 +199,11 @@ cfg_def_t	tm_cfg_def[] = {
 		" it is not set to 0 but allows dealing with NATed contacts in some "
 		"simple cases)"
 		},
+	{"local_cancel_reason",	CFG_VAR_INT | CFG_ATOMIC,	0, 1, 0, 0,
+		"if set to 1, a Reason header is added to locally generated CANCELs"
+		" (see RFC3326)" },
+	{"e2e_cancel_reason",	CFG_VAR_INT | CFG_ATOMIC,	0, 1, 0, 0,
+		"if set to 1, Reason headers from received CANCELs are copied into"
+		" the corresponding generated hop-by-hop CANCELs"},
 	{0, 0, 0, 0, 0, 0}
 };

modules/tm/config.h

@@ -21,10 +21,9 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
-/*!
- * \file 
- * \brief TM :: Configuration
- * \ingroup tm
+/** TM :: Runtime configuration variables.
+ * @file
+ * @ingroup tm
  */
 
 
@@ -136,6 +135,8 @@ struct cfg_group_tm {
 	int	reparse_on_dns_failover;
 	int disable_6xx;
 	int local_ack_mode;
+	int local_cancel_reason;
+	int e2e_cancel_reason;
 };
 
 extern struct cfg_group_tm	default_tm_cfg;

modules/tm/h_table.h

@@ -40,10 +40,9 @@
  *              inlined often used functions (andrei)
  */
 
-/*!
- * \file 
- * \brief TM :: 
- * \ingroup tm
+/**  TM :: hash table, flags and other general defines.
+ * @file 
+ * @ingroup tm
  */
 
 
@@ -281,6 +280,7 @@ struct totag_elem {
 
 #define T_DISABLE_6xx (1<<8) /* treat 6xx as a normal reply */
 #define T_DISABLE_FAILOVER (1<<9) /* don't perform dns failover */
+#define T_NO_E2E_CANCEL_REASON (1<<10) /* don't propagate CANCEL Reason */
 #define T_DONT_FORK   (T_CANCELED|T_6xx)
 
 /* unsigned short should be enough for a retr. timer: max. 65535 ticks =>

modules/tm/t_lookup.c

@@ -1265,6 +1265,8 @@ static inline void init_new_t(struct cell *new_cell, struct sip_msg *p_msg)
 					(!cfg_get(tm, tm_cfg, tm_auto_inv_100) -1);
 		new_cell->flags|=T_DISABLE_6xx &
 					(!cfg_get(tm, tm_cfg, disable_6xx) -1);
+		new_cell->flags|=T_NO_E2E_CANCEL_REASON &
+					(!!cfg_get(tm, tm_cfg, e2e_cancel_reason) -1);
 		/* reset flags */
 		new_cell->flags &=
 			(~ get_msgid_val(user_cell_reset_flags, p_msg->id, int));

modules/tm/t_msgbuilder.c

@@ -171,16 +171,18 @@ char *build_local(struct cell *Trans,unsigned int branch,
 	*len+=CONTENT_LENGTH_LEN+1 + CRLF_LEN;
 	reason_len = 0;
 	reas1 = 0;
-	/* compute reason size */
+	/* compute reason size (if no reason or disabled => reason_len == 0)*/
 	if (reason && reason->cause != CANCEL_REAS_UNKNOWN){
-		if (likely(reason->cause > 0)){
+		if (likely(reason->cause > 0 &&
+					cfg_get(tm, tm_cfg, local_cancel_reason))){
 			/* Reason: SIP;cause=<reason->cause>[;text=<reason->u.text.s>] */
 			reason_len = REASON_PREFIX_LEN + USHORT2SBUF_MAX_LEN +
 				(reason->u.text.s?
 					REASON_TEXT_LEN + 1 + reason->u.text.len + 1 : 0) +
 				CRLF_LEN;
 		} else if (reason->cause == CANCEL_REAS_RCVD_CANCEL &&
-					reason->u.e2e_cancel) {
+					reason->u.e2e_cancel &&
+					!(Trans->flags & T_NO_E2E_CANCEL_REASON)) {
 			/* parse the entire cancel, to get all the Reason headers */
 			parse_headers(reason->u.e2e_cancel, HDR_EOH_F, 0);
 			for(hdr=get_hdr(reason->u.e2e_cancel, HDR_REASON_T), reas1=hdr;
@@ -189,7 +191,7 @@ char *build_local(struct cell *Trans,unsigned int branch,
 				reason_len += hdr->len;
 				reas_last=hdr;
 			}
-		} else if (unlikely(reason->cause != -1))
+		} else if (unlikely(reason->cause < -1))
 			BUG("unhandled reason cause %d\n", reason->cause);
 	}
 	*len+= reason_len;
@@ -305,16 +307,18 @@ char *build_local_reparse(struct cell *Trans,unsigned int branch,
 	
 	reason_len = 0;
 	reas1 = 0;
-	/* compute reason size */
+	/* compute reason size (if no reason or disabled => reason_len == 0)*/
 	if (reason && reason->cause != CANCEL_REAS_UNKNOWN){
-		if (likely(reason->cause > 0)){
+		if (likely(reason->cause > 0 &&
+					cfg_get(tm, tm_cfg, local_cancel_reason))){
 			/* Reason: SIP;cause=<reason->cause>[;text=<reason->u.text.s>] */
 			reason_len = REASON_PREFIX_LEN + USHORT2SBUF_MAX_LEN +
 				(reason->u.text.s?
 					REASON_TEXT_LEN + 1 + reason->u.text.len + 1 : 0) +
 				CRLF_LEN;
 		} else if (reason->cause == CANCEL_REAS_RCVD_CANCEL &&
-					reason->u.e2e_cancel) {
+					reason->u.e2e_cancel &&
+					!(Trans->flags & T_NO_E2E_CANCEL_REASON)) {
 			/* parse the entire cancel, to get all the Reason headers */
 			parse_headers(reason->u.e2e_cancel, HDR_EOH_F, 0);
 			for(hdr=get_hdr(reason->u.e2e_cancel, HDR_REASON_T), reas1=hdr;
@@ -323,7 +327,7 @@ char *build_local_reparse(struct cell *Trans,unsigned int branch,
 				reason_len += hdr->len;
 				reas_last=hdr;
 			}
-		} else if (unlikely(reason->cause != -1))
+		} else if (unlikely(reason->cause < -1))
 			BUG("unhandled reason cause %d\n", reason->cause);
 	}
 
@@ -431,6 +435,8 @@ char *build_local_reparse(struct cell *Trans,unsigned int branch,
 				/* end of SIP message found */
 				/* add reason if needed */
 				if (reason_len) {
+					/* if reason_len !=0, no need for any reason enabled
+					   checks */
 					if (likely(reason->cause > 0)) {
 						append_str(d, REASON_PREFIX, REASON_PREFIX_LEN);
 						code_len=ushort2sbuf(reason->cause, d,

modules/tm/tm.c

@@ -87,16 +87,17 @@
  *  2008-08-11  sctp support: t_relay_to_sctp, t_replicate_sctp,
  *               t_forward_nonack_sctp (andrei)
  *  2009-03-18  added a new param: auto_inv_100_reason (aheise) 
+ *  2010-03-03  added new params: local_cancel_reason and e2e_cancel_reason
+ *              (andrei)
  */
 
-/*!
- * \file 
- * \brief TM :: Module API (core)
- * \ingroup tm
+/** TM :: Module API (core).
+ * @file 
+ * @ingroup tm
  */
 
-/*!
- * \defgroup tm TM :: Transaction stateful proxy support
+/**
+ * @defgroup tm TM :: Transaction stateful proxy support
  *
    The TM module enables stateful processing of SIP transactions. The main use
    of stateful logic, which is costly in terms of memory and CPU, is some
@@ -283,6 +284,8 @@ static int w_t_reset_max_lifetime(struct sip_msg* msg, char* foo, char* bar);
 static int t_set_auto_inv_100(struct sip_msg* msg, char* on_off, char* foo);
 static int t_set_disable_6xx(struct sip_msg* msg, char* on_off, char* foo);
 static int t_set_disable_failover(struct sip_msg* msg, char* on_off, char* f);
+static int t_set_no_e2e_cancel_reason(struct sip_msg* msg, char* on_off,
+										char* f);
 static int t_branch_timeout(struct sip_msg* msg, char*, char*);
 static int t_branch_replied(struct sip_msg* msg, char*, char*);
 static int t_any_timeout(struct sip_msg* msg, char*, char*);
@@ -428,6 +431,13 @@ static cmd_export_t cmds[]={
 			REQUEST_ROUTE|TM_ONREPLY_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE },
 	{"t_set_disable_failover", t_set_disable_failover, 1, fixup_var_int_1,
 			REQUEST_ROUTE|TM_ONREPLY_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE },
+	{"t_set_no_e2e_cancel_reason", t_set_no_e2e_cancel_reason, 1,
+		fixup_var_int_1,
+			REQUEST_ROUTE|TM_ONREPLY_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE },
+	/* alias for t_set_no_e2e_cancel_reason */
+	{"t_disable_e2e_cancel_reason", t_set_no_e2e_cancel_reason, 1,
+		fixup_var_int_1,
+			REQUEST_ROUTE|TM_ONREPLY_ROUTE|FAILURE_ROUTE|BRANCH_ROUTE },
 	{"t_branch_timeout",  t_branch_timeout,         0, 0,  FAILURE_ROUTE},
 	{"t_branch_replied",  t_branch_replied,         0, 0,  FAILURE_ROUTE},
 	{"t_any_timeout",     t_any_timeout,            0, 0, 
@@ -535,6 +545,8 @@ static param_export_t params[]={
 	{"contacts_avp",        PARAM_STRING, &contacts_avp_param                },
 	{"disable_6xx_block",   PARAM_INT, &default_tm_cfg.disable_6xx           },
 	{"local_ack_mode",      PARAM_INT, &default_tm_cfg.local_ack_mode        },
+	{"local_cancel_reason", PARAM_INT, &default_tm_cfg.local_cancel_reason   },
+	{"e2e_cancel_reason",   PARAM_INT, &default_tm_cfg.e2e_cancel_reason     },
 	{0,0,0}
 };
 
@@ -1736,6 +1748,9 @@ T_SET_FLAG_GEN_FUNC(t_set_disable_6xx, T_DISABLE_6xx)
 T_SET_FLAG_GEN_FUNC(t_set_disable_failover, T_DISABLE_FAILOVER)
 
 
+/* disable/enable e2e cancel reason copy for the current transaction */
+T_SET_FLAG_GEN_FUNC(t_set_no_e2e_cancel_reason, T_NO_E2E_CANCEL_REASON)
+
 
 /* script function, FAILURE_ROUTE only, returns true if the 
  * choosed "failure" branch failed because of a timeout,