NAT code

Collaboration diagram for NAT code:

Enumerations
enum	switch_nat_type_t { SWITCH_NAT_TYPE_NONE, SWITCH_NAT_TYPE_PMP, SWITCH_NAT_TYPE_UPNP }
enum	switch_nat_ip_proto_t { SWITCH_NAT_UDP, SWITCH_NAT_TCP }

Functions
const char *	switch_nat_get_type (void)
void	switch_nat_init (switch_memory_pool_t *pool, switch_bool_t mapping)
	Initilize the NAT Traversal System. More...
void	switch_nat_late_init (void)
	Initilize the rest of the NAT Traversal System. More...
void	switch_nat_shutdown (void)
	Shuts down the NAT Traversal System. More...
char *	switch_nat_status (void)
	Returns a list of nat mappings and other status info. More...
void	switch_nat_republish (void)
	Republishes the nap mappings. More...
void	switch_nat_reinit (void)
	re-initializes NAT subsystem More...
void	switch_nat_set_mapping (switch_bool_t mapping)
	Update the setting if port mapping will be created. More...
switch_status_t	switch_nat_add_mapping (switch_port_t port, switch_nat_ip_proto_t proto, switch_port_t *external_port, switch_bool_t sticky)
	Maps a port through the NAT Traversal System. More...
switch_bool_t	switch_nat_is_initialized (void)
	Has the NAT subsystem been initialized. More...
switch_status_t	switch_nat_del_mapping (switch_port_t port, switch_nat_ip_proto_t proto)
	Deletes a NAT mapping. More...

Detailed Description

Enumeration Type Documentation

enum switch_nat_ip_proto_t

Enumerator
SWITCH_NAT_UDP
SWITCH_NAT_TCP

Definition at line 47 of file switch_nat.h.

             {
        SWITCH_NAT_UDP,
        SWITCH_NAT_TCP
} switch_nat_ip_proto_t;

enum switch_nat_type_t

Enumerator
SWITCH_NAT_TYPE_NONE
SWITCH_NAT_TYPE_PMP
SWITCH_NAT_TYPE_UPNP

Definition at line 41 of file switch_nat.h.

                                   {
        SWITCH_NAT_TYPE_NONE,
        SWITCH_NAT_TYPE_PMP,
        SWITCH_NAT_TYPE_UPNP
} switch_nat_type_t;

Function Documentation

switch_status_t switch_nat_add_mapping	(	switch_port_t	port,
		switch_nat_ip_proto_t	proto,
		switch_port_t *	external_port,
		switch_bool_t	sticky
	)

Maps a port through the NAT Traversal System.

Parameters

port	Internal port to map
proto	Protocol
external_port	[out] Mapped external port
sticky	make the mapping permanent

Definition at line 619 of file switch_nat.c.

References switch_nat_add_mapping_internal(), and SWITCH_TRUE.

Referenced by switch_core_media_choose_port().

{
        return switch_nat_add_mapping_internal(port, proto, external_port, sticky, SWITCH_TRUE);
}

switch_status_t switch_nat_del_mapping	(	switch_port_t	port,
		switch_nat_ip_proto_t	proto
	)

Deletes a NAT mapping.

Parameters

proto

Protocol

Definition at line 625 of file switch_nat.c.

References nat_globals_t::nat_type, switch_event_add_header(), switch_event_add_header_string(), switch_event_create, switch_event_fire, SWITCH_EVENT_NAT, switch_nat_del_mapping_pmp(), switch_nat_del_mapping_upnp(), SWITCH_NAT_TYPE_PMP, SWITCH_NAT_TYPE_UPNP, SWITCH_STACK_BOTTOM, SWITCH_STATUS_FALSE, and SWITCH_STATUS_SUCCESS.

Referenced by switch_core_media_deactivate_rtp().

{
        switch_status_t status = SWITCH_STATUS_FALSE;
        switch_event_t *event = NULL;

        switch (nat_globals.nat_type) {
        case SWITCH_NAT_TYPE_PMP:
                status = switch_nat_del_mapping_pmp(port, proto);
                break;
        case SWITCH_NAT_TYPE_UPNP:
                status = switch_nat_del_mapping_upnp(port, proto);
                break;
        default:
                break;
        }

        if (status == SWITCH_STATUS_SUCCESS) {
                switch_event_create(&event, SWITCH_EVENT_NAT);
                switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "op", "del");
                switch_event_add_header(event, SWITCH_STACK_BOTTOM, "port", "%d", port);
                switch_event_add_header(event, SWITCH_STACK_BOTTOM, "proto", "%d", proto);
                switch_event_fire(&event);
        }

        return status;
}

const char* switch_nat_get_type

(

void

)

Definition at line 575 of file switch_nat.c.

References nat_globals_t::nat_type_str.

{
        return nat_globals.nat_type_str;
}

void switch_nat_init	(	switch_memory_pool_t *	pool,
		switch_bool_t	mapping
	)

Initilize the NAT Traversal System.

Parameters

pool	the memory pool to use for long term allocations

Note

Generally called by the core_init

Definition at line 399 of file switch_nat.c.

References nat_globals_t::descURL, first_init, init_pmp(), init_upnp(), initialized, nat_globals_t::mapping, memset(), nat_thread_p, nat_globals_t::nat_type, nat_globals_t::nat_type_str, pool, nat_globals_perm_t::pool, nat_globals_t::pub_addr, nat_globals_t::pvt_addr, SWITCH_CHANNEL_LOG, switch_core_set_variable(), SWITCH_FALSE, switch_find_local_ip(), SWITCH_LOG_DEBUG, SWITCH_LOG_INFO, switch_log_printf(), switch_nat_thread_start(), SWITCH_NAT_TYPE_PMP, switch_safe_free, SWITCH_TRUE, and nat_globals_t::urls.

Referenced by switch_core_init(), and switch_nat_reinit().

{
        /* try free dynamic data structures prior to resetting to 0 */
        FreeUPNPUrls(&nat_globals.urls);
        switch_safe_free(nat_globals.descURL);

        memset(&nat_globals, 0, sizeof(nat_globals));

        if (first_init) {
                memset(&nat_globals_perm, 0, sizeof(nat_globals_perm));
                nat_globals_perm.pool = pool;
        }

        nat_globals.mapping = mapping;

        switch_find_local_ip(nat_globals.pvt_addr, sizeof(nat_globals.pvt_addr), NULL, AF_INET);


        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Scanning for NAT\n");

        init_pmp();

        if (!nat_globals.nat_type) {
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG, "Checking for UPnP\n");
                init_upnp();
        }

        if (nat_globals.nat_type) {
                switch_core_set_variable("nat_public_addr", nat_globals.pub_addr);
                switch_core_set_variable("nat_private_addr", nat_globals.pvt_addr);
                switch_core_set_variable("nat_type", nat_globals.nat_type == SWITCH_NAT_TYPE_PMP ? "pmp" : "upnp");
                strncpy(nat_globals.nat_type_str, nat_globals.nat_type == SWITCH_NAT_TYPE_PMP ? "pmp" : "upnp", sizeof(nat_globals.nat_type_str) - 1);
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "NAT detected type: %s, ExtIP: '%s'\n",
                                                  nat_globals.nat_type == SWITCH_NAT_TYPE_PMP ? "pmp" : "upnp", nat_globals.pub_addr);

                if (!nat_thread_p) {
                        switch_nat_thread_start();
                }
        } else {
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "No PMP or UPnP NAT devices detected!\n");
        }
        first_init = SWITCH_FALSE;
        initialized = SWITCH_TRUE;
}

switch_bool_t switch_nat_is_initialized

(

void

)

Has the NAT subsystem been initialized.

Definition at line 736 of file switch_nat.c.

References initialized.

{
        return initialized;
}

void switch_nat_late_init

(

void

)

Initilize the rest of the NAT Traversal System.

Note

nat_init is called prior to some other modules being loaded. This method allows us to init the rest of the NAT system.

Definition at line 708 of file switch_nat.c.

References NAT_REFRESH_INTERVAL, nat_globals_perm_t::running, SSHF_OWN_THREAD, switch_epoch_time_now(), and switch_scheduler_add_task().

Referenced by switch_core_init().

{
        if (nat_globals_perm.running == 1) {
                switch_scheduler_add_task(switch_epoch_time_now(NULL) + NAT_REFRESH_INTERVAL, switch_nat_republish_sched, "nat_republish", "core", 0, NULL,
                                                                  SSHF_OWN_THREAD);
        }
}

void switch_nat_reinit

(

void

)

re-initializes NAT subsystem

Definition at line 215 of file switch_nat.c.

References nat_globals_t::mapping, nat_globals_perm_t::pool, and switch_nat_init().

Referenced by switch_nat_multicast_runtime().

{
        switch_nat_init(nat_globals_perm.pool, nat_globals.mapping);
}

void switch_nat_republish

(

void

)

Republishes the nap mappings.

Definition at line 652 of file switch_nat.c.

References switch_stream_handle::data, switch_api_execute(), SWITCH_CHANNEL_LOG, SWITCH_FALSE, SWITCH_LOG_DEBUG1, SWITCH_LOG_ERROR, switch_log_printf(), switch_nat_add_mapping_internal(), switch_safe_free, SWITCH_STANDARD_STREAM, switch_xml_child(), switch_xml_find_child(), switch_xml_free(), switch_xml_next, switch_xml_parse_str_dup, and switch_xml::txt.

Referenced by switch_nat_multicast_runtime(), and SWITCH_STANDARD_SCHED_FUNC().

{
        switch_xml_t natxml = NULL;
        switch_xml_t row = NULL;
        switch_xml_t child = NULL;
        switch_stream_handle_t stream = { 0 };
        SWITCH_STANDARD_STREAM(stream);

        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "Refreshing nat maps\n");

        switch_api_execute("show", "nat_map as xml", NULL, &stream);

        if (!(natxml = switch_xml_parse_str_dup(stream.data))) {
                switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Unable to parse XML: %s\n", (char *) stream.data);
                switch_safe_free(stream.data);
                return;
        }

        /* iterate the xml and publish the mappings */
        row = switch_xml_find_child(natxml, "row", "row_id", "1");
        while (row != NULL) {
                char *sport = NULL;
                char *sproto = NULL;
                switch_port_t port;
                switch_nat_ip_proto_t proto;

                if ((child = switch_xml_child(row, "port"))) {
                        sport = child->txt;
                }
                if ((child = switch_xml_child(row, "proto_num"))) {
                        sproto = child->txt;
                }

                if (sport && sproto) {
                        port = (switch_port_t) (atoi(sport));
                        proto = (switch_nat_ip_proto_t) (atoi(sproto));
                        switch_nat_add_mapping_internal(port, proto, NULL, SWITCH_FALSE, SWITCH_FALSE);
                } else {
                        switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Unable to parse port/proto info: XML: %s\n", (char *) stream.data);
                }

                row = switch_xml_next(row);
        }

        switch_safe_free(stream.data);
        switch_xml_free(natxml);
}

void switch_nat_set_mapping

(

switch_bool_t

mapping

)

Update the setting if port mapping will be created.

Definition at line 210 of file switch_nat.c.

References nat_globals_t::mapping.

{
        nat_globals.mapping = mapping;
}

void switch_nat_shutdown

(

void

)

Shuts down the NAT Traversal System.

Definition at line 741 of file switch_nat.c.

References nat_globals_t::descURL, switch_nat_thread_stop(), switch_safe_free, and nat_globals_t::urls.

Referenced by switch_core_destroy().

{
        switch_nat_thread_stop();
        FreeUPNPUrls(&nat_globals.urls);
        switch_safe_free(nat_globals.descURL);
}

char* switch_nat_status

(

void

)

Returns a list of nat mappings and other status info.

Note

caller must free the string

Definition at line 716 of file switch_nat.c.

References switch_stream_handle::data, nat_globals_t::mapping, nat_globals_t::nat_type, nat_globals_t::pub_addr, switch_api_execute(), SWITCH_NAT_TYPE_PMP, SWITCH_NAT_TYPE_UPNP, SWITCH_STANDARD_STREAM, and switch_stream_handle::write_function.

{
        switch_stream_handle_t stream = { 0 };
        SWITCH_STANDARD_STREAM(stream);

        stream.write_function(&stream, "Nat Type: %s, ExtIP: %s\n",
                                                  (nat_globals.nat_type == SWITCH_NAT_TYPE_UPNP) ? "UPNP" : (nat_globals.nat_type == SWITCH_NAT_TYPE_PMP ? "NAT-PMP" : "UNKNOWN"),
                                                  nat_globals.pub_addr);

        if (nat_globals.mapping) {
                stream.write_function(&stream, "NAT port mapping enabled.\n");
        } else {
                stream.write_function(&stream, "NAT port mapping disabled.\n");
        }

        switch_api_execute("show", "nat_map", NULL, &stream);

        return stream.data;                     /* caller frees */
}