etc: kamailio.cfg polishing

- version in comments updated to 5.0
- use block comment style for descriptions of gobal and module
  parameters (was mixed) - now description is in between /* */ and
  commented code starts with #
- removed #!ifdef WITH_SRCPATH and commented the mpath - let it be the
  default one in the code, because it is set at compile time and can be
  OS specific. Loading the modules from source tree can be done by
  providing to kamailio in command line: -L modules/
- added option to block 401/407 from downstream. Kamailio is the one
  authenticating local users.

etc/kamailio.cfg

@@ -1,6 +1,6 @@
 #!KAMAILIO
 #
-# Kamailio (OpenSER) SIP Server v4.4 - default configuration script
+# Kamailio (OpenSER) SIP Server v5.0 - default configuration script
 #     - web: http://www.kamailio.org
 #     - git: http://sip-router.org
 #
@@ -9,6 +9,13 @@
 # Refer to the Core CookBook at http://www.kamailio.org/wiki/
 # for an explanation of possible statements, functions and parameters.
 #
+# Note: the comments can be:
+#     - lines starting with #, but not the pre-processor directives,
+#       which start with #!, like #!define, #!ifdef, #!endif, #!else, #!trydef,
+#       #!subst, #!substdef, ...
+#     - lines starting with //
+#     - blocks enclosed in between /* */
+#
 # Several features can be enabled using '#!define WITH_FEATURE' directives:
 #
 # *** To run in debug mode:
@@ -76,6 +83,9 @@
 # *** To block 3XX redirect replies execute:
 #     - define WITH_BLOCK3XX
 #
+# *** To block 401 and 407 authentication replies execute:
+#     - define WITH_BLOCK401407
+#
 # *** To enable VoiceMail routing execute:
 #     - define WITH_VOICEMAIL
 #     - set the value of voicemail.srv_ip
@@ -147,70 +157,65 @@ memlog=5
 
 log_facility=LOG_LOCAL0
 
-# number of SIP routing processes
+/* number of SIP routing processes */
 children=8
 
 /* uncomment the next line to disable TCP (default on) */
-#disable_tcp=yes
+# disable_tcp=yes
 
 /* uncomment the next line to disable the auto discovery of local aliases
-   based on reverse DNS on IPs (default on) */
-#auto_aliases=no
+ * based on reverse DNS on IPs (default on) */
+# auto_aliases=no
 
 /* add local domain aliases */
 #alias="sip.mydomain.com"
 
 /* uncomment and configure the following line if you want Kamailio to
-   bind on a specific interface/port/proto (default bind on all available) */
-#listen=udp:10.0.0.10:5060
+ * bind on a specific interface/port/proto (default bind on all available) */
+# listen=udp:10.0.0.10:5060
 
-/* port to listen to */
-#port=5060
+/* port to listen to (default 5060 for udp, tcp, scrtp, or 5061 for tls)*/
+# port=5060
 
 #!ifdef WITH_TLS
 enable_tls=yes
 #!endif
 
-# life time of TCP connection when there is no traffic
-# - a bit higher than registration expires to cope with UA behind NAT
+/* life time of TCP connection when there is no traffic
+ * - a bit higher than registration expires to cope with UA behind NAT */
 tcp_connection_lifetime=3605
 
 ####### Custom Parameters #########
 
-# These parameters can be modified runtime via RPC interface
-# - see the documentation of 'cfg_rpc' module.
-#
-# Format: group.id = value 'desc' description
-# Access: $sel(cfg_get.group.id) or @cfg_get.group.id
-#
+/* These parameters can be modified runtime via RPC interface
+ * - see the documentation of 'cfg_rpc' module.
+ *
+ * Format: group.id = value 'desc' description
+ * Access: $sel(cfg_get.group.id) or @cfg_get.group.id */
 
 #!ifdef WITH_PSTN
-# PSTN GW Routing
-#
-# - pstn.gw_ip: valid IP or hostname as string value, example:
-# pstn.gw_ip = "10.0.0.101" desc "My PSTN GW Address"
-#
-# - by default is empty to avoid misrouting
+/* PSTN GW Routing
+ *
+ * - pstn.gw_ip: valid IP or hostname as string value, example:
+ * pstn.gw_ip = "10.0.0.101" desc "My PSTN GW Address"
+ *
+ * - by default is empty to avoid misrouting */
 pstn.gw_ip = "" desc "PSTN GW Address"
 pstn.gw_port = "" desc "PSTN GW Port"
 #!endif
 
 #!ifdef WITH_VOICEMAIL
-# VoiceMail Routing on offline, busy or no answer
-#
-# - by default Voicemail server IP is empty to avoid misrouting
+/* VoiceMail Routing on offline, busy or no answer
+ *
+ * - by default Voicemail server IP is empty to avoid misrouting */
 voicemail.srv_ip = "" desc "VoiceMail IP Address"
 voicemail.srv_port = "5060" desc "VoiceMail Port"
 #!endif
 
 ####### Modules Section ########
 
-# set paths to location of modules (to sources or installation folders)
-#!ifdef WITH_SRCPATH
-mpath="modules/"
-#!else
-mpath="/usr/local/lib/kamailio/modules/"
-#!endif
+/* set paths to location of modules */
+# mpath="/usr/local/lib/kamailio/modules/"
 
 #!ifdef WITH_MYSQL
 loadmodule "db_mysql.so"
@@ -287,10 +292,12 @@ loadmodule "debugger.so"
 
 
 # ----- mi_fifo params -----
-#modparam("mi_fifo", "fifo_name", "/var/run/kamailio/kamailio_fifo")
+/* set the path to MI fifo control file */
+# modparam("mi_fifo", "fifo_name", "/var/run/kamailio/kamailio_fifo")
 
 # ----- ctl params -----
-#modparam("ctl", "binrpc", "unix:/var/run/kamailio/kamailio_ctl")
+/* set the path to RPC unix socket control file */
+# modparam("ctl", "binrpc", "unix:/var/run/kamailio/kamailio_ctl")
 
 # ----- tm params -----
 # auto-discard branches from previous serial forking leg
@@ -313,10 +320,10 @@ modparam("registrar", "method_filtering", 1)
 /* uncomment the next line to disable parallel forking via location */
 # modparam("registrar", "append_branches", 0)
 /* uncomment the next line not to allow more than 10 contacts per AOR */
-#modparam("registrar", "max_contacts", 10)
-# max value for expires of registrations
+# modparam("registrar", "max_contacts", 10)
+/* max value for expires of registrations */
 modparam("registrar", "max_expires", 3600)
-# set it to 1 to enable GRUU
+/* set it to 1 to enable GRUU */
 modparam("registrar", "gruu_enabled", 0)
 
 
@@ -326,8 +333,8 @@ modparam("acc", "early_media", 0)
 modparam("acc", "report_ack", 0)
 modparam("acc", "report_cancels", 0)
 /* by default ww do not adjust the direct of the sequential requests.
-   if you enable this parameter, be sure the enable "append_fromtag"
-   in "rr" module */
+ * if you enable this parameter, be sure the enable "append_fromtag"
+ * in "rr" module */
 modparam("acc", "detect_direction", 0)
 /* account triggers (flags) */
 modparam("acc", "log_flag", FLT_ACC)
@@ -390,7 +397,7 @@ modparam("speeddial", "use_domain", MULTIDOMAIN)
 # ----- domain params -----
 #!ifdef WITH_MULTIDOMAIN
 modparam("domain", "db_url", DBURL)
-# register callback to match myself condition with domains list
+/* register callback to match myself condition with domains list */
 modparam("domain", "register_myself", 1)
 #!endif
 
@@ -433,7 +440,7 @@ modparam("pike", "reqs_density_per_unit", 16)
 modparam("pike", "remove_latency", 4)
 
 # ----- htable params -----
-# ip ban htable with autoexpire after 5 minutes
+/* ip ban htable with autoexpire after 5 minutes */
 modparam("htable", "htable", "ipban=>size=8;autoexpire=300;")
 #!endif
 
@@ -452,9 +459,9 @@ modparam("debugger", "log_level_name", "exec")
 ####### Routing Logic ########
 
 
-# Main SIP request routing logic
-# - processing of any incoming SIP request starts with this route
-# - note: this is the same as route { ... }
+/* Main SIP request routing logic
+ * - processing of any incoming SIP request starts with this route
+ * - note: this is the same as route { ... } */
 request_route {
 
 	# per request initial checks
@@ -936,6 +943,14 @@ failure_route[MANAGE_FAILURE] {
 	}
 #!endif
 
+#!ifdef WITH_BLOCK401407
+	# block call redirect based on 401, 407 replies.
+	if (t_check_status("401|407")) {
+		t_reply("404","Not found");
+		exit;
+	}
+#!endif
+
 #!ifdef WITH_VOICEMAIL
 	# serial forking
 	# - route to voicemail on busy or no answer (timeout)