| /**************************************************************************** |
| * net/icmpv6/icmpv6_autoconfig.c |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. The |
| * ASF licenses this file to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance with the |
| * License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations |
| * under the License. |
| * |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Included Files |
| ****************************************************************************/ |
| |
| #include <nuttx/config.h> |
| |
| #include <stdint.h> |
| #include <string.h> |
| #include <assert.h> |
| #include <errno.h> |
| #include <debug.h> |
| |
| #include <arpa/inet.h> |
| |
| #include <nuttx/semaphore.h> |
| #include <nuttx/net/net.h> |
| #include <nuttx/net/netdev.h> |
| |
| #include "devif/devif.h" |
| #include "netdev/netdev.h" |
| #include "inet/inet.h" |
| #include "icmpv6/icmpv6.h" |
| #include "utils/utils.h" |
| |
| #ifdef CONFIG_NET_ICMPv6_AUTOCONF |
| |
| /**************************************************************************** |
| * Private Types |
| ****************************************************************************/ |
| |
| /* This structure holds the state of the send operation until it can be |
| * operated upon by the event handler. |
| */ |
| |
| struct icmpv6_router_s |
| { |
| FAR struct devif_callback_s *snd_cb; /* Reference to callback instance */ |
| sem_t snd_sem; /* Used to wake up the waiting thread */ |
| volatile bool snd_sent; /* True: if request sent */ |
| bool snd_advertise; /* True: Send Neighbor Advertisement */ |
| uint8_t snd_ifname[IFNAMSIZ]; /* Interface name */ |
| int16_t snd_result; /* Result of the send */ |
| }; |
| |
| /**************************************************************************** |
| * Private Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: icmpv6_router_terminate |
| ****************************************************************************/ |
| |
| static void icmpv6_router_terminate(FAR struct icmpv6_router_s *state, |
| int result) |
| { |
| /* Don't allow any further call backs. */ |
| |
| state->snd_sent = true; |
| state->snd_result = (int16_t)result; |
| state->snd_cb->flags = 0; |
| state->snd_cb->priv = NULL; |
| state->snd_cb->event = NULL; |
| |
| /* Wake up the waiting thread */ |
| |
| nxsem_post(&state->snd_sem); |
| } |
| |
| /**************************************************************************** |
| * Name: icmpv6_router_eventhandler |
| ****************************************************************************/ |
| |
| static uint16_t icmpv6_router_eventhandler(FAR struct net_driver_s *dev, |
| FAR void *priv, uint16_t flags) |
| { |
| FAR struct icmpv6_router_s *state = (FAR struct icmpv6_router_s *)priv; |
| |
| ninfo("flags: %04x sent: %d\n", flags, state->snd_sent); |
| |
| if (state) |
| { |
| /* Check if the network is still up */ |
| |
| if ((flags & NETDEV_DOWN) != 0) |
| { |
| nerr("ERROR: Interface is down\n"); |
| icmpv6_router_terminate(state, -ENETUNREACH); |
| return flags; |
| } |
| |
| /* Check if the outgoing packet is available. It may have been claimed |
| * by a send event handler serving a different thread -OR- if the |
| * output buffer currently contains unprocessed incoming data. In |
| * these cases we will just have to wait for the next polling cycle. |
| */ |
| |
| else if (dev->d_sndlen > 0 || (flags & ICMPv6_NEWDATA) != 0) |
| { |
| /* Another thread has beat us sending data or the buffer is busy, |
| * Check for a timeout. If not timed out, wait for the next |
| * polling cycle and check again. |
| */ |
| |
| /* REVISIT: No timeout. Just wait for the next polling cycle */ |
| |
| return flags; |
| } |
| |
| /* Prepare device buffer */ |
| |
| if (netdev_iob_prepare(dev, false, 0) != OK) |
| { |
| return flags; |
| } |
| |
| /* It looks like we are good to send the data. |
| * |
| * Copy the packet data into the device packet buffer and send it. |
| */ |
| |
| if (state->snd_advertise) |
| { |
| /* Send the ICMPv6 Neighbor Advertisement message, we should |
| * already have link-local address by previous logic. |
| */ |
| |
| icmpv6_advertise(dev, netdev_ipv6_lladdr(dev), g_ipv6_allnodes); |
| } |
| else |
| { |
| /* Send the ICMPv6 Router Solicitation message */ |
| |
| icmpv6_rsolicit(dev); |
| } |
| |
| IFF_SET_IPv6(dev->d_flags); |
| |
| /* Don't allow any further call backs. */ |
| |
| icmpv6_router_terminate(state, OK); |
| } |
| |
| return flags; |
| } |
| |
| /**************************************************************************** |
| * Name: icmpv6_send_message |
| * |
| * Description: |
| * Send an ICMPv6 Router Solicitation to resolve an IPv6 address. |
| * |
| * Input Parameters: |
| * dev - The device to use to send the solicitation |
| * advertise - True: Send the Neighbor Advertisement message |
| * |
| * Returned Value: |
| * Zero (OK) is returned on success; On error a negated errno value is |
| * returned. |
| * |
| * Assumptions: |
| * The network is locked. |
| * |
| ****************************************************************************/ |
| |
| static int icmpv6_send_message(FAR struct net_driver_s *dev, bool advertise) |
| { |
| struct icmpv6_router_s state; |
| int ret; |
| |
| /* Initialize the state structure with the network locked. */ |
| |
| nxsem_init(&state.snd_sem, 0, 0); /* Doesn't really fail */ |
| |
| /* Remember the routing device name */ |
| |
| strlcpy((FAR char *)state.snd_ifname, (FAR const char *)dev->d_ifname, |
| IFNAMSIZ); |
| |
| /* Allocate resources to receive a callback. This and the following |
| * initialization is performed with the network lock because we don't |
| * want anything to happen until we are ready. |
| */ |
| |
| state.snd_cb = devif_callback_alloc(dev, |
| &dev->d_conncb, |
| &dev->d_conncb_tail); |
| if (!state.snd_cb) |
| { |
| nerr("ERROR: Failed to allocate a cllback\n"); |
| ret = -ENOMEM; |
| goto errout_with_semaphore; |
| } |
| |
| /* Arm the callback */ |
| |
| state.snd_sent = false; |
| state.snd_result = -EBUSY; |
| state.snd_advertise = advertise; |
| state.snd_cb->flags = (ICMPv6_POLL | NETDEV_DOWN); |
| state.snd_cb->priv = (FAR void *)&state; |
| state.snd_cb->event = icmpv6_router_eventhandler; |
| |
| /* Notify the device driver that new TX data is available. */ |
| |
| netdev_txnotify_dev(dev); |
| |
| /* Wait for the send to complete or an error to occur |
| * net_sem_wait will also terminate if a signal is received. |
| */ |
| |
| do |
| { |
| net_sem_wait(&state.snd_sem); |
| } |
| while (!state.snd_sent); |
| |
| ret = state.snd_result; |
| devif_dev_callback_free(dev, state.snd_cb); |
| |
| errout_with_semaphore: |
| nxsem_destroy(&state.snd_sem); |
| return ret; |
| } |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: icmpv6_autoconfig |
| * |
| * Description: |
| * Perform IPv6 auto-configuration to assign an IPv6 address to this |
| * device. |
| * |
| * Stateless auto-configuration exploits several other features in IPv6, |
| * including link-local addresses, multi-casting, the Neighbor Discovery |
| * protocol, and the ability to generate the interface identifier of an |
| * address from the underlying link layer address. The general idea is |
| * to have a device generate a temporary address until it can determine |
| * the characteristics of the network it is on, and then create a permanent |
| * address it can use based on that information. |
| * |
| * Input Parameters: |
| * dev - The device driver structure to assign the address to |
| * psock - A pointer to a NuttX-specific, internal socket structure |
| * |
| * Returned Value: |
| * Zero (OK) is returned on success; A negated errno value is returned on |
| * any failure. |
| * |
| ****************************************************************************/ |
| |
| int icmpv6_autoconfig(FAR struct net_driver_s *dev) |
| { |
| struct icmpv6_rnotify_s notify; |
| net_ipv6addr_t lladdr; |
| int retries; |
| int ret; |
| |
| /* Sanity checks */ |
| |
| DEBUGASSERT(dev); |
| ninfo("Auto-configuring %s\n", dev->d_ifname); |
| |
| /* 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(); |
| |
| /* IPv6 Stateless Autoconfiguration |
| * Reference: |
| * http://www.tcpipguide.com/free/t_IPv6AutoconfigurationandRenumbering.htm |
| * |
| * The following is a summary of the steps a device takes when using |
| * stateless auto-configuration: |
| * |
| * 1. Link-Local Address Generation: The device generates a link-local |
| * address. Recall that this is one of the two types of local-use IPv6 |
| * addresses. Link-local addresses have "1111 1110 10" for the first |
| * ten bits. The generated address uses those ten bits followed by 54 |
| * zeroes and then the 64 bit interface identifier. Typically this |
| * will be derived from the link layer (MAC) address. |
| */ |
| |
| if (netdev_ipv6_lladdr(dev) != NULL) |
| { |
| goto got_lladdr; |
| } |
| |
| icmpv6_linkipaddr(dev, lladdr); |
| |
| ninfo("lladdr=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n", |
| NTOHS(lladdr[0]), NTOHS(lladdr[1]), |
| NTOHS(lladdr[2]), NTOHS(lladdr[3]), |
| NTOHS(lladdr[4]), NTOHS(lladdr[5]), |
| NTOHS(lladdr[6]), NTOHS(lladdr[7])); |
| |
| #ifdef CONFIG_NET_ICMPv6_NEIGHBOR |
| /* 2. Link-Local Address Uniqueness Test: The node tests to ensure that |
| * the address it generated isn't for some reason already in use on the |
| * local network. (This is very unlikely to be an issue if the link- |
| * local address came from a MAC address but more likely if it was |
| * based on a generated token.) It sends a Neighbor Solicitation |
| * message using the Neighbor Discovery (ND) protocol. It then listens |
| * for a Neighbor Advertisement in response that indicates that another |
| * device is already using its link-local address; if so, either a new |
| * address must be generated, or auto-configuration fails and another |
| * method must be employed. |
| */ |
| |
| if (dev->d_lltype == NET_LL_ETHERNET || |
| dev->d_lltype == NET_LL_IEEE80211) |
| { |
| ret = icmpv6_neighbor(dev, lladdr); |
| if (ret >= 0) |
| { |
| /* Hmmm... someone else responded to our Neighbor Solicitation. We |
| * have no back-up plan in place. Just bail. |
| */ |
| |
| nerr("ERROR: IP conflict\n"); |
| |
| net_unlock(); |
| return -EEXIST; |
| } |
| } |
| #endif |
| |
| /* 3. Link-Local Address Assignment: Assuming the uniqueness test passes, |
| * the device assigns the link-local address to its IP interface. This |
| * address can be used for communication on the local network, but not |
| * on the wider Internet (since link-local addresses are not routed). |
| */ |
| |
| ret = netdev_ipv6_add(dev, lladdr, net_ipv6_mask2pref(g_ipv6_llnetmask)); |
| if (ret < 0) |
| { |
| net_unlock(); |
| return ret; |
| } |
| |
| got_lladdr: |
| /* 4. Router Contact: The node next attempts to contact a local router for |
| * more information on continuing the configuration. This is done either |
| * by listening for Router Advertisement messages sent periodically by |
| * routers, or by sending a specific Router Solicitation to ask a router |
| * for information on what to do next. |
| */ |
| |
| for (retries = 0; retries < CONFIG_ICMPv6_AUTOCONF_MAXTRIES; retries++) |
| { |
| /* Set up the Router Advertisement BEFORE we send the Router |
| * Solicitation. |
| */ |
| |
| icmpv6_rwait_setup(dev, ¬ify); |
| |
| /* Send the ICMPv6 Router solicitation message */ |
| |
| ret = icmpv6_send_message(dev, false); |
| if (ret < 0) |
| { |
| /* Remove our wait structure from the list (we may no longer be |
| * at the head of the list). |
| */ |
| |
| icmpv6_rwait_cancel(¬ify); |
| |
| nerr("ERROR: Failed send router solicitation: %d\n", ret); |
| break; |
| } |
| |
| /* Wait to receive the Router Advertisement message */ |
| |
| ret = icmpv6_rwait(¬ify, CONFIG_ICMPv6_AUTOCONF_DELAYMSEC); |
| if (ret != -ETIMEDOUT) |
| { |
| /* ETIMEDOUT is the only expected failure. We will retry on that |
| * case only. |
| */ |
| |
| break; |
| } |
| |
| ninfo("Timed out... retrying %d\n", retries + 1); |
| } |
| |
| /* Check for failures. */ |
| |
| if (ret < 0) |
| { |
| int senderr; |
| |
| nerr("ERROR: Failed to get the router advertisement: " |
| "%d (retries=%d)\n", |
| ret, retries); |
| |
| /* Claim the link local address as ours by sending the ICMPv6 Neighbor |
| * Advertisement message. |
| */ |
| |
| senderr = icmpv6_send_message(dev, true); |
| if (senderr < 0) |
| { |
| nerr("ERROR: Failed send neighbor advertisement: %d\n", senderr); |
| } |
| |
| if (ret != -EADDRNOTAVAIL) |
| { |
| /* No off-link communications; No router address. */ |
| |
| net_ipv6addr_copy(dev->d_ipv6draddr, g_ipv6_unspecaddr); |
| } |
| } |
| |
| /* 5. Router Direction: The router provides direction to the node on how |
| * to proceed with the auto-configuration. It may tell the node that on |
| * this network "stateful" auto-configuration is in use, and tell it |
| * the address of a DHCP server to use. Alternately, it will tell the |
| * host how to determine its global Internet address. |
| * |
| * 6. Global Address Configuration: Assuming that stateless auto- |
| * configuration is in use on the network, the host will configure |
| * itself with its globally-unique Internet address. This address is |
| * generally formed from a network prefix provided to the host by the |
| * router, combined with the device's identifier as generated in the |
| * first step. |
| */ |
| |
| /* On success, the new address was already set (in icmpv_rnotify()). */ |
| |
| net_unlock(); |
| return ret; |
| } |
| |
| #endif /* CONFIG_NET_ICMPv6_AUTOCONF */ |
