contiki/apps/shell/shell-wget.c
Robert Quattlebaum f145c17039 core/net/resolv: IPv6 and mDNS ("Bonjour") support. Major refactor.
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.
2013-03-10 11:40:08 -07:00

231 lines
6.3 KiB
C

/*
* Copyright (c) 2008, Swedish Institute of Computer Science.
* All rights reserved.
*
* 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 of the Institute 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 INSTITUTE 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 INSTITUTE 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.
*
* This file is part of the Contiki operating system.
*
*/
/**
* \file
* Wget Contiki shell command
* \author
* Adam Dunkels <adam@sics.se>
*/
#include "contiki.h"
#include "shell.h"
#include "webclient.h"
#include <stdio.h>
#include <string.h>
#define MAX_URLLEN 128
static char url[MAX_URLLEN];
static uint8_t running;
/*---------------------------------------------------------------------------*/
PROCESS(shell_wget_process, "wget");
SHELL_COMMAND(wget_command,
"wget",
"wget [URL]: download a file with HTTP",
&shell_wget_process);
/*---------------------------------------------------------------------------*/
static void
open_url(char *url)
{
unsigned char i, c;
static char host[32];
char *file;
register char *urlptr;
static uip_ipaddr_t addr;
/* Trim off any spaces in the end of the url. */
urlptr = url + strlen(url) - 1;
while(*urlptr == ' ' && urlptr > url) {
*urlptr = 0;
--urlptr;
}
/* Don't even try to go further if the URL is empty. */
if(urlptr == url) {
return;
}
/* See if the URL starts with http://, otherwise prepend it. */
if(strncmp(url, http_http, 7) != 0) {
while(urlptr >= url) {
*(urlptr + 7) = *urlptr;
--urlptr;
}
strncpy(url, http_http, 7);
}
/* Find host part of the URL. */
urlptr = &url[7];
if(*urlptr == '[') {
/* IPv6 address */
c = ']';
++urlptr;
} else {
c = ':';
}
for(i = 0; i < sizeof(host); ++i) {
if(*urlptr == 0 ||
*urlptr == '/' ||
*urlptr == ' ' ||
*urlptr == c) {
host[i] = 0;
break;
}
host[i] = *urlptr;
++urlptr;
}
if(*urlptr == ']') {
/* Move past end of IPv6 host */
urlptr++;
}
/* XXX: Here we should find the port part of the URL, but this isn't
currently done because of laziness from the programmer's side
:-) */
/* Find file part of the URL. */
while(*urlptr != '/' && *urlptr != 0) {
++urlptr;
}
if(*urlptr == '/') {
file = urlptr;
} else {
file = "/";
}
#if UIP_UDP
/* Try to lookup the hostname. If it fails, we initiate a hostname
lookup and print out an informative message on the statusbar. */
if(uiplib_ipaddrconv(host, &addr) == 0) {
uip_ipaddr_t *addrptr;
shell_output_str(&wget_command, "Not an IP address", "");
if(resolv_lookup(host, &addrptr) == RESOLV_STATUS_UNCACHED) {
shell_output_str(&wget_command, "Not resolved", "");
resolv_query(host);
return;
}
uip_ipaddr_copy(&addr, addrptr);
}
#else /* UIP_UDP */
uiplib_ipaddrconv(host, &addr);
#endif /* UIP_UDP */
/* The hostname we present in the hostname table, so we send out the
initial GET request. */
shell_output_str(&wget_command, "Host ", host);
shell_output_str(&wget_command, "File ", file);
if(webclient_get(host, 80, file) == 0) {
shell_output_str(&wget_command, "Out of memory", "");
} else {
shell_output_str(&wget_command, "Connecting...", "");
}
}
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(shell_wget_process, ev, data)
{
PROCESS_BEGIN();
strncpy(url, data, sizeof(url));
open_url(url);
running = 1;
while(running) {
PROCESS_WAIT_EVENT();
if(ev == tcpip_event) {
webclient_appcall(data);
#if UIP_UDP
} else if(ev == resolv_event_found) {
/* Either found a hostname, or not. */
if((char *)data != NULL &&
resolv_lookup((char *)data, NULL) == RESOLV_STATUS_CACHED) {
open_url(url);
} else {
shell_output_str(&wget_command, "Host not found.", "");
}
#endif /* UIP_UDP */
}
}
PROCESS_END();
}
/*---------------------------------------------------------------------------*/
void
shell_wget_init(void)
{
shell_register_command(&wget_command);
}
/*---------------------------------------------------------------------------*/
void
webclient_datahandler(char *data, uint16_t len)
{
if(len == 0) {
running = 0;
} else {
shell_output(&wget_command, data, len, NULL, 0);
}
}
/*---------------------------------------------------------------------------*/
void
webclient_connected(void)
{
shell_output_str(&wget_command, "connected", "");
}
/*---------------------------------------------------------------------------*/
void
webclient_timedout(void)
{
shell_output_str(&wget_command, "timedout", "");
running = 0;
}
/*---------------------------------------------------------------------------*/
void
webclient_aborted(void)
{
shell_output_str(&wget_command, "aborted", "");
running = 0;
}
/*---------------------------------------------------------------------------*/
void
webclient_closed(void)
{
shell_output_str(&wget_command, "closed", "");
running = 0;
}
/*---------------------------------------------------------------------------*/