osd-contiki/examples/wget/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

266 lines
7 KiB
C

/*
* Copyright (c) 2002, Adam Dunkels.
* 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. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 desktop environment
*
*
*/
#include <stdio.h>
#include <string.h>
#include "contiki-net.h"
#include "webclient.h"
#include "cfs/cfs.h"
#include "lib/petsciiconv.h"
PROCESS(wget_process, "Wget");
AUTOSTART_PROCESSES(&wget_process);
static int file = -1;
static char url[128];
/*-----------------------------------------------------------------------------------*/
/* Called when the URL present in the global "url" variable should be
* opened. It will call the hostname resolver as well as the HTTP
* client requester.
*/
static void
start_get(void)
{
uip_ipaddr_t addr;
unsigned char i;
static char host[32];
char *file;
register char *urlptr;
/* 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];
for(i = 0; i < sizeof(host); ++i) {
if(*urlptr == 0 ||
*urlptr == '/' ||
*urlptr == ' ' ||
*urlptr == ':') {
host[i] = 0;
break;
}
host[i] = *urlptr;
++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
/* First check if the host is an IP address. */
if(uiplib_ipaddrconv(host, &addr) == 0) {
uip_ipaddr_t *addrptr;
/* Try to lookup the hostname. If it fails, we initiate a hostname
lookup and print out an informative message on the
statusbar. */
if(resolv_lookup(host, &addrptr) != RESOLV_STATUS_CACHED) {
resolv_query(host);
puts("Resolving 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. */
if(webclient_get(host, 80, file) == 0) {
puts("Out of memory error");
} else {
puts("Connecting...");
}
}
/*-----------------------------------------------------------------------------------*/
static void
app_quit(void)
{
if(file != -1) {
cfs_close(file);
}
puts("Press any key to continue...");
getchar();
process_exit(&wget_process);
LOADER_UNLOAD();
}
/*-----------------------------------------------------------------------------------*/
PROCESS_THREAD(wget_process, ev, data)
{
static char name[32];
static unsigned char i;
PROCESS_BEGIN();
/* Allow other processes to initialize properly. */
for(i = 0; i < 10; ++i) {
PROCESS_PAUSE();
}
fputs("\nGet url:", stdout);
gets(url);
fputs("\nSave as:", stdout);
gets(name);
puts("");
file = cfs_open(name, CFS_WRITE);
if(file == -1) {
printf("Open error with '%s'\n", name);
app_quit();
} else {
petsciiconv_toascii(url, sizeof(url));
start_get();
}
while(1) {
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) {
start_get();
} else {
puts("Host not found");
app_quit();
}
#endif /* UIP_UDP */
}
}
PROCESS_END();
}
/*-----------------------------------------------------------------------------------*/
/* Callback function. Called from the webclient when the HTTP
* connection was abruptly aborted.
*/
void
webclient_aborted(void)
{
puts("Connection reset by peer");
app_quit();
}
/*-----------------------------------------------------------------------------------*/
/* Callback function. Called from the webclient when the HTTP
* connection timed out.
*/
void
webclient_timedout(void)
{
puts("Connection timed out");
app_quit();
}
/*-----------------------------------------------------------------------------------*/
/* Callback function. Called from the webclient when the HTTP
* connection was closed after a request from the "webclient_close()"
* function. .
*/
void
webclient_closed(void)
{
puts("Done.");
app_quit();
}
/*-----------------------------------------------------------------------------------*/
/* Callback function. Called from the webclient when the HTTP
* connection is connected.
*/
void
webclient_connected(void)
{
puts("Request sent...");
}
/*-----------------------------------------------------------------------------------*/
/* Callback function. Called from the webclient module when HTTP data
* has arrived.
*/
void
webclient_datahandler(char *data, uint16_t len)
{
static unsigned long dload_bytes;
int ret;
if(len > 0) {
dload_bytes += len;
printf("Downloading (%lu bytes)\n", dload_bytes);
if(file != -1) {
ret = cfs_write(file, data, len);
if(ret != len) {
printf("Wrote only %d bytes\n", ret);
}
}
}
if(data == NULL) {
printf("Finished downloading %lu bytes.\n", dload_bytes);
app_quit();
}
}
/*-----------------------------------------------------------------------------------*/