gnunet-service-nat_externalip.c File Reference

Code to figure out what our external IPv4 address(es) might be (external IPv4s are what is seen on the rest of the Internet). More...

#include "platform.h"
#include <math.h>
#include "gnunet_util_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_signatures.h"
#include "gnunet_statistics_service.h"
#include "gnunet_resolver_service.h"
#include "gnunet_nat_service.h"
#include "gnunet-service-nat.h"
#include "gnunet-service-nat_externalip.h"
#include "gnunet-service-nat_stun.h"
#include "gnunet-service-nat_mini.h"
#include "gnunet-service-nat_helper.h"
#include "nat.h"
#include <gcrypt.h>

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Data Structures
struct	GN_ExternalIPMonitor
	Handle to monitor for external IP changes. More...

Macros
#define	EXTERN_IP_RETRY_TIMEOUT
	How long do we wait until we re-try running external-ip if the command failed to terminate nicely? More...
#define	EXTERN_IP_RETRY_FAILURE
	How long do we wait until we re-try running external-ip if the command failed (but terminated)? More...
#define	EXTERN_IP_RETRY_SUCCESS
	How long do we wait until we re-try running external-ip if the command succeeded? More...

Functions
static void	notify_monitors_external_ipv4_change (int add, const struct in_addr *v4)
	Tell relevant clients about a change in our external IPv4 address. More...
static void	run_external_ip (void *cls)
	Task used to run external-ip to get our external IPv4 address and pass it to NATed clients if possible. More...
static void	handle_external_ip (void *cls, const struct in_addr *addr, enum GNUNET_NAT_StatusCode result)
	We learn our current external IP address. More...
void	GN_nat_status_changed (int have_nat)
	We have changed our opinion about being NATed in the first place. More...
struct GN_ExternalIPMonitor *	GN_external_ipv4_monitor_start (GN_NotifyExternalIPv4Change cb, void *cb_cls)
	Start monitoring external IPv4 addresses. More...
void	GN_external_ipv4_monitor_stop (struct GN_ExternalIPMonitor *mon)
	Stop calling monitor. More...

Variables
static struct GN_ExternalIPMonitor *	mon_head
	List of monitors, kept in DLL. More...
static struct GN_ExternalIPMonitor *	mon_tail
	List of monitors, kept in DLL. More...
static struct GNUNET_SCHEDULER_Task *	probe_external_ip_task
	Task run to obtain our external IP (if enable_upnp is set and if we find we have a NATed IP address). More...
static struct GNUNET_NAT_ExternalHandle *	probe_external_ip_op
	Handle to our operation to run external-ip. More...
static struct in_addr	mini_external_ipv4
	What is our external IP address as claimed by external-ip? 0 for unknown. More...

Detailed Description

Code to figure out what our external IPv4 address(es) might be (external IPv4s are what is seen on the rest of the Internet).

This can be implemented using different methods, and we allow the main service to be notified about changes to what we believe is our external IPv4 address.

Note that this is explicitly only about NATed systems; if one of our network interfaces has a global IP address this does not count as "external".

Functions for monitoring external IPv4 addresses

Author

Christian Grothoff

Definition in file gnunet-service-nat_externalip.c.

Macro Definition Documentation

EXTERN_IP_RETRY_TIMEOUT

#define EXTERN_IP_RETRY_TIMEOUT

Value:

    GNUNET_TIME_relative_multiply ( \
    GNUNET_TIME_UNIT_MINUTES, 15)

How long do we wait until we re-try running external-ip if the command failed to terminate nicely?

Definition at line 57 of file gnunet-service-nat_externalip.c.

EXTERN_IP_RETRY_FAILURE

#define EXTERN_IP_RETRY_FAILURE

Value:

    GNUNET_TIME_relative_multiply ( \
    GNUNET_TIME_UNIT_MINUTES, 30)

How long do we wait until we re-try running external-ip if the command failed (but terminated)?

Definition at line 64 of file gnunet-service-nat_externalip.c.

EXTERN_IP_RETRY_SUCCESS

#define EXTERN_IP_RETRY_SUCCESS

Value:

    GNUNET_TIME_relative_multiply ( \
    GNUNET_TIME_UNIT_MINUTES, 5)

How long do we wait until we re-try running external-ip if the command succeeded?

Definition at line 71 of file gnunet-service-nat_externalip.c.

Function Documentation

notify_monitors_external_ipv4_change()

static void notify_monitors_external_ipv4_change ( int  add, const struct in_addr *  v4  )

static

Tell relevant clients about a change in our external IPv4 address.

Parameters

add	GNUNET_YES to add, GNUNET_NO to remove
v4	the external address that changed

Definition at line 138 of file gnunet-service-nat_externalip.c.

{
  for (struct GN_ExternalIPMonitor *mon = mon_head;
       NULL != mon;
       mon = mon->next)
    mon->cb (mon->cb_cls,
             v4,
             add);
}

References add, mon_head, and GN_ExternalIPMonitor::next.

Referenced by handle_external_ip().

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run_external_ip()

static void run_external_ip ( void *  cls )

static

Task used to run external-ip to get our external IPv4 address and pass it to NATed clients if possible.

Parameters

cls

NULL

Definition at line 221 of file gnunet-service-nat_externalip.c.

{
  probe_external_ip_task
    = GNUNET_SCHEDULER_add_delayed (EXTERN_IP_RETRY_TIMEOUT,
                                    &run_external_ip,
                                    NULL);
  if (NULL != probe_external_ip_op)
  {
    GNUNET_NAT_mini_get_external_ipv4_cancel_ (probe_external_ip_op);
    probe_external_ip_op = NULL;
  }
  probe_external_ip_op
    = GNUNET_NAT_mini_get_external_ipv4_ (&handle_external_ip,
                                          NULL);
}

References EXTERN_IP_RETRY_TIMEOUT, GNUNET_NAT_mini_get_external_ipv4_(), GNUNET_NAT_mini_get_external_ipv4_cancel_(), GNUNET_SCHEDULER_add_delayed(), handle_external_ip(), probe_external_ip_op, probe_external_ip_task, and run_external_ip().

Referenced by GN_nat_status_changed(), handle_external_ip(), and run_external_ip().

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handle_external_ip()

static void handle_external_ip ( void *  cls, const struct in_addr *  addr, enum GNUNET_NAT_StatusCode  result  )

static

We learn our current external IP address.

If it changed, notify all of our applicable clients. Also re-schedule run_external_ip with an appropriate timeout.

Parameters

cls	NULL
addr	the address, NULL on errors
result	GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code

Definition at line 170 of file gnunet-service-nat_externalip.c.

{
  char buf[INET_ADDRSTRLEN];
 
  probe_external_ip_op = NULL;
  GNUNET_SCHEDULER_cancel (probe_external_ip_task);
  probe_external_ip_task
    = GNUNET_SCHEDULER_add_delayed ((NULL == addr)
                                    ? EXTERN_IP_RETRY_FAILURE
                                    : EXTERN_IP_RETRY_SUCCESS,
                                    &run_external_ip,
                                    NULL);
  switch (result)
  {
  case GNUNET_NAT_ERROR_SUCCESS:
    GNUNET_assert (NULL != addr);
    if (addr->s_addr == mini_external_ipv4.s_addr)
      return;   /* not change */
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                "Our external IP is now %s\n",
                inet_ntop (AF_INET,
                           addr,
                           buf,
                           sizeof(buf)));
    if (0 != mini_external_ipv4.s_addr)
      notify_monitors_external_ipv4_change (GNUNET_NO,
                                            &mini_external_ipv4);
    mini_external_ipv4 = *addr;
    notify_monitors_external_ipv4_change (GNUNET_YES,
                                          &mini_external_ipv4);
    break;
 
  default:
    if (0 != mini_external_ipv4.s_addr)
      notify_monitors_external_ipv4_change (GNUNET_NO,
                                            &mini_external_ipv4);
    mini_external_ipv4.s_addr = 0;
    break;
  }
}

References EXTERN_IP_RETRY_FAILURE, EXTERN_IP_RETRY_SUCCESS, GNUNET_assert, GNUNET_ERROR_TYPE_DEBUG, GNUNET_log, GNUNET_NAT_ERROR_SUCCESS, GNUNET_NO, GNUNET_SCHEDULER_add_delayed(), GNUNET_SCHEDULER_cancel(), GNUNET_YES, mini_external_ipv4, notify_monitors_external_ipv4_change(), probe_external_ip_op, probe_external_ip_task, result, and run_external_ip().

Referenced by run_external_ip().

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GN_nat_status_changed()

void GN_nat_status_changed

(

int

have_nat

)

We have changed our opinion about being NATed in the first place.

Adapt our probing.

Parameters

have_nat

GNUNET_YES if we believe we are behind NAT

Definition at line 245 of file gnunet-service-nat_externalip.c.

{
  if (GNUNET_YES != enable_upnp)
    return;
  if ((GNUNET_YES == have_nat) &&
      (NULL == probe_external_ip_task) &&
      (NULL == probe_external_ip_op))
  {
    probe_external_ip_task
      = GNUNET_SCHEDULER_add_now (&run_external_ip,
                                  NULL);
    return;
  }
  if (GNUNET_NO == have_nat)
  {
    if (NULL != probe_external_ip_task)
    {
      GNUNET_SCHEDULER_cancel (probe_external_ip_task);
      probe_external_ip_task = NULL;
    }
    if (NULL != probe_external_ip_op)
    {
      GNUNET_NAT_mini_get_external_ipv4_cancel_ (probe_external_ip_op);
      probe_external_ip_op = NULL;
    }
  }
}

References enable_upnp, GNUNET_NAT_mini_get_external_ipv4_cancel_(), GNUNET_NO, GNUNET_SCHEDULER_add_now(), GNUNET_SCHEDULER_cancel(), GNUNET_YES, probe_external_ip_op, probe_external_ip_task, and run_external_ip().

Referenced by run_scan(), and shutdown_task().

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GN_external_ipv4_monitor_start()

struct GN_ExternalIPMonitor * GN_external_ipv4_monitor_start	(	GN_NotifyExternalIPv4Change	cb,
		void *	cb_cls
	)

Start monitoring external IPv4 addresses.

Parameters

cb	function to call on changes
cb_cls	closure for cb

Returns

handle to cancel

Definition at line 282 of file gnunet-service-nat_externalip.c.

{
  struct GN_ExternalIPMonitor *mon;
 
  mon = GNUNET_new (struct GN_ExternalIPMonitor);
  mon->cb = cb;
  mon->cb_cls = cb_cls;
  GNUNET_CONTAINER_DLL_insert (mon_head,
                               mon_tail,
                               mon);
  if (0 != mini_external_ipv4.s_addr)
    cb (cb_cls,
        &mini_external_ipv4,
        GNUNET_YES);
  return mon;
}

References GN_ExternalIPMonitor::cb, GN_ExternalIPMonitor::cb_cls, GNUNET_CONTAINER_DLL_insert, GNUNET_new, GNUNET_YES, mini_external_ipv4, mon_head, and mon_tail.

Referenced by handle_register().

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GN_external_ipv4_monitor_stop()

void GN_external_ipv4_monitor_stop

(

struct GN_ExternalIPMonitor *

mon

)

Stop calling monitor.

Parameters

mon	monitor to call

Definition at line 307 of file gnunet-service-nat_externalip.c.

{
  GNUNET_CONTAINER_DLL_remove (mon_head,
                               mon_tail,
                               mon);
  GNUNET_free (mon);
}

References GNUNET_CONTAINER_DLL_remove, GNUNET_free, mon_head, and mon_tail.

Referenced by client_disconnect_cb().

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Variable Documentation

mon_head

struct GN_ExternalIPMonitor* mon_head

static

List of monitors, kept in DLL.

Definition at line 105 of file gnunet-service-nat_externalip.c.

Referenced by GN_external_ipv4_monitor_start(), GN_external_ipv4_monitor_stop(), and notify_monitors_external_ipv4_change().

mon_tail

struct GN_ExternalIPMonitor* mon_tail

static

List of monitors, kept in DLL.

Definition at line 110 of file gnunet-service-nat_externalip.c.

Referenced by GN_external_ipv4_monitor_start(), and GN_external_ipv4_monitor_stop().

probe_external_ip_task

struct GNUNET_SCHEDULER_Task* probe_external_ip_task

static

Task run to obtain our external IP (if enable_upnp is set and if we find we have a NATed IP address).

Definition at line 116 of file gnunet-service-nat_externalip.c.

Referenced by GN_nat_status_changed(), handle_external_ip(), and run_external_ip().

probe_external_ip_op

struct GNUNET_NAT_ExternalHandle* probe_external_ip_op

static

Handle to our operation to run external-ip.

Definition at line 121 of file gnunet-service-nat_externalip.c.

Referenced by GN_nat_status_changed(), handle_external_ip(), and run_external_ip().

mini_external_ipv4

struct in_addr mini_external_ipv4

static

What is our external IP address as claimed by external-ip? 0 for unknown.

Definition at line 127 of file gnunet-service-nat_externalip.c.

Referenced by GN_external_ipv4_monitor_start(), and handle_external_ip().