nuttx/net/icmpv6/icmpv6_rnotify.c
Gregory Nutt 68a115aed9 net/icmpv6/icmpv6_autoconfig.c and icmpv6_rnotify.c: Don't take the network device down when reconfiguring only the IP address from within ICMPv6 logic. Recommended by Xiang Xiao in order to avoid the long delays of bringing some networks back up.
Normally it is required that the network be in the "down" state when re-configuring the network interface.  This is thought not to be a necessary here because.

  1. The ICMPv6 logic here runs with the network locked so there can be no outgoing packets with bad source IP addresses from any asynchronous network activity using the device being reconfigured.
  2. Incoming packets depend only upon the MAC filtering.  Network drivers do not use the IP address; they filter incoming packets using only the MAC address which is not being changed here.
2018-11-10 07:13:54 -06:00

355 lines
11 KiB
C

/****************************************************************************
* net/icmpv6/icmpv6_rnotify.c
*
* Copyright (C) 2015-2016 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <string.h>
#include <time.h>
#include <semaphore.h>
#include <errno.h>
#include <debug.h>
#include <netinet/in.h>
#include <nuttx/irq.h>
#include <nuttx/semaphore.h>
#include <nuttx/net/net.h>
#include <nuttx/net/netdev.h>
#include "netdev/netdev.h"
#include "utils/utils.h"
#include "icmpv6/icmpv6.h"
#ifdef CONFIG_NET_ICMPv6_AUTOCONF
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/* List of tasks waiting for Neighbor Discover events */
static struct icmpv6_rnotify_s *g_icmpv6_rwaiters;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: icmpv6_setaddresses
*
* Description:
* We successfully obtained the Router Advertisement. See the new IPv6
* addresses in the driver structure.
*
****************************************************************************/
static void icmpv6_setaddresses(FAR struct net_driver_s *dev,
const net_ipv6addr_t draddr,
const net_ipv6addr_t prefix,
unsigned int preflen)
{
unsigned int i;
/* Lock the network.
*
* NOTE: Normally it is required that the network be in the "down" state
* when re-configuring the network interface. This is thought not to be
* a problem here because.
*
* 1. The ICMPv6 logic here runs with the network locked so there can be
* no outgoing packets with bad source IP addresses from any
* asynchronous network activity using the device being reconfigured.
* 2. Incoming packets depend only upon the MAC filtering. Network
* drivers do not use the IP address; they filter incoming packets
* using only the MAC address which is not being changed here.
*/
net_lock();
/* Create an address mask from the prefix */
if (preflen > 128)
{
preflen = 128;
}
net_ipv6_pref2mask(preflen, dev->d_ipv6netmask);
ninfo("preflen=%d netmask=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
preflen, dev->d_ipv6netmask[0], dev->d_ipv6netmask[1],
dev->d_ipv6netmask[2], dev->d_ipv6netmask[3], dev->d_ipv6netmask[4],
dev->d_ipv6netmask[5], dev->d_ipv6netmask[6], dev->d_ipv6netmask[7]);
/* Copy prefix to the current IPv6 address, applying the mask */
for (i = 0; i < 7; i++)
{
dev->d_ipv6addr[i] = (dev->d_ipv6addr[i] & ~dev->d_ipv6netmask[i]) |
(prefix[i] & dev->d_ipv6netmask[i]);
}
ninfo("prefix=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
prefix[0], prefix[1], prefix[2], prefix[3],
prefix[4], prefix[6], prefix[6], prefix[7]);
ninfo("IP address=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
dev->d_ipv6addr[0], dev->d_ipv6addr[1], dev->d_ipv6addr[2],
dev->d_ipv6addr[3], dev->d_ipv6addr[4], dev->d_ipv6addr[6],
dev->d_ipv6addr[6], dev->d_ipv6addr[7]);
/* Finally, copy the router address */
net_ipv6addr_copy(dev->d_ipv6draddr, draddr);
ninfo("DR address=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
dev->d_ipv6draddr[0], dev->d_ipv6draddr[1], dev->d_ipv6draddr[2],
dev->d_ipv6draddr[3], dev->d_ipv6draddr[4], dev->d_ipv6draddr[6],
dev->d_ipv6draddr[6], dev->d_ipv6draddr[7]);
net_unlock();
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: icmpv6_rwait_setup
*
* Description:
* Called BEFORE an Router Solicitation is sent. This function sets up
* the Router Advertisement timeout before the Router Solicitation
* is sent so that there is no race condition when icmpv6_rwait() is
* called.
*
* Assumptions:
* This function is called from icmpv6_autoconfig() and executes in the
* normal tasking environment.
*
****************************************************************************/
void icmpv6_rwait_setup(FAR struct net_driver_s *dev,
FAR struct icmpv6_rnotify_s *notify)
{
irqstate_t flags;
/* Initialize the wait structure */
memcpy(notify->rn_ifname, dev->d_ifname, IFNAMSIZ);
notify->rn_result = -ETIMEDOUT;
/* This semaphore is used for signaling and, hence, should not have
* priority inheritance enabled.
*/
(void)nxsem_init(&notify->rn_sem, 0, 0);
nxsem_setprotocol(&notify->rn_sem, SEM_PRIO_NONE);
/* Add the wait structure to the list with interrupts disabled */
flags = enter_critical_section();
notify->rn_flink = g_icmpv6_rwaiters;
g_icmpv6_rwaiters = notify;
leave_critical_section(flags);
}
/****************************************************************************
* Name: icmpv6_rwait_cancel
*
* Description:
* Cancel any wait set after icmpv6_rwait_setup() is called but before
* icmpv6_rwait()is called (icmpv6_rwait() will automatically cancel the
* wait).
*
* Assumptions:
* This function may execute in the interrupt context when called from
* icmpv6_rwait().
*
****************************************************************************/
int icmpv6_rwait_cancel(FAR struct icmpv6_rnotify_s *notify)
{
FAR struct icmpv6_rnotify_s *curr;
FAR struct icmpv6_rnotify_s *prev;
irqstate_t flags;
int ret = -ENOENT;
ninfo("Canceling...\n");
/* Remove our wait structure from the list (we may no longer be at the
* head of the list).
*/
flags = enter_critical_section();
for (prev = NULL, curr = g_icmpv6_rwaiters;
curr && curr != notify;
prev = curr, curr = curr->rn_flink);
DEBUGASSERT(curr && curr == notify);
if (curr)
{
if (prev)
{
prev->rn_flink = notify->rn_flink;
}
else
{
g_icmpv6_rwaiters = notify->rn_flink;
}
ret = OK;
}
leave_critical_section(flags);
(void)nxsem_destroy(&notify->rn_sem);
return ret;
}
/****************************************************************************
* Name: icmpv6_rwait
*
* Description:
* Called each time that a Router Solicitation is sent. This function
* will sleep until either: (1) the matching Router Advertisement is
* received, or (2) a timeout occurs.
*
* Assumptions:
* This function is called from icmpv6_autoconfig() and must execute with
* the network locked.
*
****************************************************************************/
int icmpv6_rwait(FAR struct icmpv6_rnotify_s *notify,
FAR struct timespec *timeout)
{
struct timespec abstime;
irqstate_t flags;
int ret;
ninfo("Waiting...\n");
/* And wait for the Neighbor Advertisement (or a timeout). Interrupts will
* be re-enabled while we wait.
*/
flags = enter_critical_section();
DEBUGVERIFY(clock_gettime(CLOCK_REALTIME, &abstime));
abstime.tv_sec += timeout->tv_sec;
abstime.tv_nsec += timeout->tv_nsec;
if (abstime.tv_nsec >= 1000000000)
{
abstime.tv_sec++;
abstime.tv_nsec -= 1000000000;
}
/* REVISIT: If net_timedwait() is awakened with signal, we will return
* the wrong error code.
*/
(void)net_timedwait(&notify->rn_sem, &abstime);
ret = notify->rn_result;
/* Remove our wait structure from the list (we may no longer be at the
* head of the list).
*/
(void)icmpv6_rwait_cancel(notify);
/* Re-enable interrupts and return the result of the wait */
leave_critical_section(flags);
return ret;
}
/****************************************************************************
* Name: icmpv6_rnotify
*
* Description:
* Called each time that a Router Advertisement is received in order to
* wake-up any threads that may be waiting for this particular Router
* Advertisement.
*
* Assumptions:
* This function is called from the MAC device driver indirectly through
* icmpv6_icmpv6in() will execute with the network locked.
*
****************************************************************************/
void icmpv6_rnotify(FAR struct net_driver_s *dev, const net_ipv6addr_t draddr,
const net_ipv6addr_t prefix, unsigned int preflen)
{
FAR struct icmpv6_rnotify_s *curr;
ninfo("Notified\n");
/* Find an entry with the matching device name in the list of waiters */
for (curr = g_icmpv6_rwaiters; curr; curr = curr->rn_flink)
{
/* Does this entry match? If the result is okay, then we have
* already notified this waiter and it has not yet taken the
* entry from the list.
*/
if (curr->rn_result != OK &&
strncmp(curr->rn_ifname, dev->d_ifname, IFNAMSIZ) == 0)
{
/* Yes.. Set the new network addresses. */
icmpv6_setaddresses(dev, draddr, prefix, preflen);
/* And signal the waiting, returning success */
curr->rn_result = OK;
nxsem_post(&curr->rn_sem);
break;
}
}
}
#endif /* CONFIG_NET_ICMPv6_AUTOCONF */