f145c17039
This patch updates the DNS resolver to support IPv6 and introduces an improved API for looking up DNS entries. This patch also adds optional support for mDNS lookups and responses to the DNS resolver. Here is a quick summary of the changes: * Added support for IPv6 lookups. * DNS queries now honor record expiration. * Added support for mDNS, compatible with "Bonjour". * Implemented a new lookup api, `resolv_lookup2()`, which provides more information about the state of the record(error, expired, looking-up, etc.). About mDNS/Bonjour Support -------------------------- This patch adds basic support for mDNS/Bonjour, which allows you to refer to the name of a device instead of its IP address. This is incredibly convenient for IPv6 addresses because they tend to be very long and difficult to remember. It is especially important for link-local IPv6 addresses, since not all programs support the '%' notation for indicating a network interface (required on systems with more than one network interface to disambiguate). In other words, instead of typing in this: * `http://[fe80::58dc:d7ed:a644:628f%en1]/` You can type this instead: * `http://contiki.local/` Huge improvement, no? The convenience extends beyond that: this mechanism can be used for nodes to talk to each other based on their human-readable names instead of their IPv6 addresses. So instead of a switch on `aaaa::58dc:d7ed:a644:628f` triggering an actuator on `aaaa::ed26:19c1:4bd2:f95b`, `light-switch.local` can trigger the actuator on `living-room-lights.local`. What you need to do to be able to look up `.local` names on your workstation depends on a few factors: * Your machine needs to be able to send and receive multicast packets to and from the LoWPAN. You can do this easily with the Jackdaw firmware on an RZUSBStick. If you have a border router, you will need it to bridge the mDNS multicast packets across the border. * If you are using a Mac, you win. All Apple devices support mDNS lookups. * If you are using Windows, you can install Apple's Bonjour for Windows package. (This may be already installed on your machine if you have installed iTunes) After you install this you can easily do `.local` lookups. * If you are using a Unix machine, you can install Avahi. The default hostname is set to `contiki.local.`. You can change the hostname programmatically by calling `resolv_set_hostname()`. You can change the default hostname by changing `CONTIKI_CONF_DEFAULT_HOSTNAME`. You may disable mDNS support by setting `RESOLV_CONF_SUPPORTS_MDNS` to `0`. --------------------------------- core/net/resolv: `resolv_lookup2()` -> `resolv_lookup()` Note that this patch should fix several `resolv_lookup()` bugs that already existed. There were many cases where `resolv_lookup()` was being called and the IP address ignored, but later code assumed that the IP address had been fetched... ANYWAY, those should be fixed now. --------------------------------- examples/udp-ipv6: Updated client to use MDNS to lookup the server. Also updated the Cooja regression test simulation.
110 lines
3.6 KiB
C
110 lines
3.6 KiB
C
/**
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* \file
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* uIP DNS resolver code header file.
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* \author Adam Dunkels <adam@dunkels.com>
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*/
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/*
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* Copyright (c) 2002-2003, Adam Dunkels.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote
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* products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* This file is part of the uIP TCP/IP stack.
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*
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*
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*/
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#ifndef __RESOLV_H__
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#define __RESOLV_H__
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#include "contiki.h"
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#include "uip.h"
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/** If RESOLV_CONF_SUPPORTS_MDNS is set, then queries
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* for domain names in the `local` TLD will use MDNS and
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* will respond to MDNS queries for this device's hostname,
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* as described by draft-cheshire-dnsext-multicastdns.
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*/
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#ifndef RESOLV_CONF_SUPPORTS_MDNS
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#define RESOLV_CONF_SUPPORTS_MDNS (1)
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#endif
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/**
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* Event that is broadcasted when a DNS name has been resolved.
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*/
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CCIF extern process_event_t resolv_event_found;
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/* Functions. */
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CCIF void resolv_conf(const uip_ipaddr_t * dnsserver);
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CCIF uip_ipaddr_t *resolv_getserver(void);
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enum {
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/** Hostname is fresh and usable. This response is cached and will eventually
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* expire to RESOLV_STATUS_EXPIRED.*/
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RESOLV_STATUS_CACHED = 0,
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/** Hostname was not found in the cache. Use resolv_query() to look it up. */
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RESOLV_STATUS_UNCACHED,
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/** Hostname was found, but it's status has expired. The address returned
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* should not be used. Use resolv_query() to freshen it up.
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*/
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RESOLV_STATUS_EXPIRED,
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/** The server has returned a not-found response for this domain name.
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* This response is cached for the period described in the server.
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* You may issue a new query at any time using resolv_query(), but
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* you will generally want to wait until this domain's status becomes
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* RESOLV_STATUS_EXPIRED.
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*/
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RESOLV_STATUS_NOT_FOUND,
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/** This hostname is in the process of being resolved. Try again soon. */
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RESOLV_STATUS_RESOLVING,
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/** Some sort of server error was encountered while trying to look up this
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* record. This response is cached and will eventually expire to
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* RESOLV_STATUS_EXPIRED.
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*/
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RESOLV_STATUS_ERROR,
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};
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typedef uint8_t resolv_status_t;
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CCIF resolv_status_t resolv_lookup(const char *name, uip_ipaddr_t ** ipaddr);
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CCIF void resolv_query(const char *name);
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#if RESOLV_CONF_SUPPORTS_MDNS
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CCIF void resolv_set_hostname(const char *hostname);
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CCIF const char *resolv_get_hostname(void);
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#endif
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PROCESS_NAME(resolv_process);
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#endif /* __RESOLV_H__ */
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