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/*
* UPnP WPS Device - Event processing
* Copyright (c) 2000-2003 Intel Corporation
* Copyright (c) 2006-2007 Sony Corporation
* Copyright (c) 2008-2009 Atheros Communications
* Copyright (c) 2009-2010, Jouni Malinen <j@w1.fi>
*
* See wps_upnp.c for more details on licensing and code history.
*/
#include "includes.h"
#include <assert.h>
#include "common.h"
#include "eloop.h"
#include "uuid.h"
#include "http_client.h"
#include "wps_defs.h"
#include "wps_upnp.h"
#include "wps_upnp_i.h"
/*
* Event message generation (to subscribers)
*
* We make a separate copy for each message for each subscriber. This memory
* wasted could be limited (adding code complexity) by sharing copies, keeping
* a usage count and freeing when zero.
*
* Sending a message requires using a HTTP over TCP NOTIFY
* (like a PUT) which requires a number of states..
*/
#define MAX_EVENTS_QUEUED 20 /* How far behind queued events */
#define MAX_FAILURES 10 /* Drop subscription after this many failures */
/* How long to wait before sending event */
#define EVENT_DELAY_SECONDS 0
#define EVENT_DELAY_MSEC 0
/*
* Event information that we send to each subscriber is remembered in this
* struct. The event cannot be sent by simple UDP; it has to be sent by a HTTP
* over TCP transaction which requires various states.. It may also need to be
* retried at a different address (if more than one is available).
*
* TODO: As an optimization we could share data between subscribers.
*/
struct wps_event_ {
struct dl_list list;
struct subscription *s; /* parent */
unsigned subscriber_sequence; /* which event for this subscription*/
unsigned int retry; /* which retry */
struct subscr_addr *addr; /* address to connect to */
struct wpabuf *data; /* event data to send */
struct http_client *http_event;
};
/* event_clean -- clean sockets etc. of event
* Leaves data, retry count etc. alone.
*/
static void event_clean(struct wps_event_ *e)
{
if (e->s->current_event == e)
e->s->current_event = NULL;
http_client_free(e->http_event);
e->http_event = NULL;
}
/* event_delete -- delete single unqueued event
* (be sure to dequeue first if need be)
*/
static void event_delete(struct wps_event_ *e)
{
wpa_printf(MSG_DEBUG, "WPS UPnP: Delete event %p", e);
event_clean(e);
wpabuf_free(e->data);
os_free(e);
}
/* event_dequeue -- get next event from the queue
* Returns NULL if empty.
*/
static struct wps_event_ *event_dequeue(struct subscription *s)
{
struct wps_event_ *e;
e = dl_list_first(&s->event_queue, struct wps_event_, list);
if (e) {
wpa_printf(MSG_DEBUG, "WPS UPnP: Dequeue event %p for "
"subscription %p", e, s);
dl_list_del(&e->list);
}
return e;
}
/* event_delete_all -- delete entire event queue and current event */
void event_delete_all(struct subscription *s)
{
struct wps_event_ *e;
while ((e = event_dequeue(s)) != NULL)
event_delete(e);
if (s->current_event) {
event_delete(s->current_event);
/* will set: s->current_event = NULL; */
}
}
/**
* event_retry - Called when we had a failure delivering event msg
* @e: Event
* @do_next_address: skip address e.g. on connect fail
*/
static void event_retry(struct wps_event_ *e, int do_next_address)
{
struct subscription *s = e->s;
struct upnp_wps_device_sm *sm = s->sm;
wpa_printf(MSG_DEBUG, "WPS UPnP: Retry event %p for subscription %p",
e, s);
event_clean(e);
/* will set: s->current_event = NULL; */
if (do_next_address) {
e->retry++;
wpa_printf(MSG_DEBUG, "WPS UPnP: Try address %d", e->retry);
}
if (e->retry >= dl_list_len(&s->addr_list)) {
wpa_printf(MSG_DEBUG, "WPS UPnP: Giving up on sending event "
"for %s", e->addr->domain_and_port);
event_delete(e);
s->last_event_failed = 1;
if (!dl_list_empty(&s->event_queue))
event_send_all_later(s->sm);
return;
}
dl_list_add(&s->event_queue, &e->list);
event_send_all_later(sm);
}
static struct wpabuf * event_build_message(struct wps_event_ *e)
{
struct wpabuf *buf;
char *b;
buf = wpabuf_alloc(1000 + wpabuf_len(e->data));
if (buf == NULL)
return NULL;
wpabuf_printf(buf, "NOTIFY %s HTTP/1.1\r\n", e->addr->path);
wpabuf_put_str(buf, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");
wpabuf_printf(buf, "HOST: %s\r\n", e->addr->domain_and_port);
wpabuf_put_str(buf, "CONTENT-TYPE: text/xml; charset=\"utf-8\"\r\n"
"NT: upnp:event\r\n"
"NTS: upnp:propchange\r\n");
wpabuf_put_str(buf, "SID: uuid:");
b = wpabuf_put(buf, 0);
uuid_bin2str(e->s->uuid, b, 80);
wpabuf_put(buf, os_strlen(b));
wpabuf_put_str(buf, "\r\n");
wpabuf_printf(buf, "SEQ: %u\r\n", e->subscriber_sequence);
wpabuf_printf(buf, "CONTENT-LENGTH: %d\r\n",
(int) wpabuf_len(e->data));
wpabuf_put_str(buf, "\r\n"); /* terminating empty line */
wpabuf_put_buf(buf, e->data);
return buf;
}
static void event_addr_failure(struct wps_event_ *e)
{
struct subscription *s = e->s;
e->addr->num_failures++;
wpa_printf(MSG_DEBUG, "WPS UPnP: Failed to send event %p to %s "
"(num_failures=%u)",
e, e->addr->domain_and_port, e->addr->num_failures);
if (e->addr->num_failures < MAX_FAILURES) {
/* Try other addresses, if available */
event_retry(e, 1);
return;
}
/*
* If other side doesn't like what we say, forget about them.
* (There is no way to tell other side that we are dropping them...).
*/
wpa_printf(MSG_DEBUG, "WPS UPnP: Deleting subscription %p "
"address %s due to errors", s, e->addr->domain_and_port);
dl_list_del(&e->addr->list);
subscr_addr_delete(e->addr);
e->addr = NULL;
if (dl_list_empty(&s->addr_list)) {
/* if we've given up on all addresses */
wpa_printf(MSG_DEBUG, "WPS UPnP: Removing subscription %p "
"with no addresses", s);
dl_list_del(&s->list);
subscription_destroy(s);
return;
}
/* Try other addresses, if available */
event_retry(e, 0);
}
static void event_http_cb(void *ctx, struct http_client *c,
enum http_client_event event)
{
struct wps_event_ *e = ctx;
struct subscription *s = e->s;
wpa_printf(MSG_DEBUG, "WPS UPnP: HTTP client callback: e=%p c=%p "
"event=%d", e, c, event);
switch (event) {
case HTTP_CLIENT_OK:
wpa_printf(MSG_DEBUG,
"WPS UPnP: Got event %p reply OK from %s",
e, e->addr->domain_and_port);
e->addr->num_failures = 0;
s->last_event_failed = 0;
event_delete(e);
/* Schedule sending more if there is more to send */
if (!dl_list_empty(&s->event_queue))
event_send_all_later(s->sm);
break;
case HTTP_CLIENT_FAILED:
wpa_printf(MSG_DEBUG, "WPS UPnP: Event send failure");
event_addr_failure(e);
break;
case HTTP_CLIENT_INVALID_REPLY:
wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid reply");
event_addr_failure(e);
break;
case HTTP_CLIENT_TIMEOUT:
wpa_printf(MSG_DEBUG, "WPS UPnP: Event send timeout");
event_addr_failure(e);
break;
}
}
/* event_send_start -- prepare to send a event message to subscriber
*
* This gets complicated because:
* -- The message is sent via TCP and we have to keep the stream open
* for 30 seconds to get a response... then close it.
* -- But we might have other event happen in the meantime...
* we have to queue them, if we lose them then the subscriber will
* be forced to unsubscribe and subscribe again.
* -- If multiple URLs are provided then we are supposed to try successive
* ones after 30 second timeout.
* -- The URLs might use domain names instead of dotted decimal addresses,
* and resolution of those may cause unwanted sleeping.
* -- Doing the initial TCP connect can take a while, so we have to come
* back after connection and then send the data.
*
* Returns nonzero on error;
*
* Prerequisite: No current event send (s->current_event == NULL)
* and non-empty queue.
*/
static int event_send_start(struct subscription *s)
{
struct wps_event_ *e;
unsigned int itry;
struct wpabuf *buf;
/*
* Assume we are called ONLY with no current event and ONLY with
* nonempty event queue and ONLY with at least one address to send to.
*/
if (dl_list_empty(&s->addr_list))
return -1;
if (s->current_event)
return -1;
if (dl_list_empty(&s->event_queue))
return -1;
s->current_event = e = event_dequeue(s);
/* Use address according to number of retries */
itry = 0;
dl_list_for_each(e->addr, &s->addr_list, struct subscr_addr, list)
if (itry++ == e->retry)
break;
if (itry < e->retry)
return -1;
buf = event_build_message(e);
if (buf == NULL) {
event_retry(e, 0);
return -1;
}
e->http_event = http_client_addr(&e->addr->saddr, buf, 0,
event_http_cb, e);
if (e->http_event == NULL) {
wpabuf_free(buf);
event_retry(e, 0);
return -1;
}
return 0;
}
/* event_send_all_later_handler -- actually send events as needed */
static void event_send_all_later_handler(void *eloop_data, void *user_ctx)
{
struct upnp_wps_device_sm *sm = user_ctx;
struct subscription *s, *tmp;
int nerrors = 0;
sm->event_send_all_queued = 0;
dl_list_for_each_safe(s, tmp, &sm->subscriptions, struct subscription,
list) {
if (s->current_event == NULL /* not busy */ &&
!dl_list_empty(&s->event_queue) /* more to do */) {
if (event_send_start(s))
nerrors++;
}
}
if (nerrors) {
/* Try again later */
event_send_all_later(sm);
}
}
/* event_send_all_later -- schedule sending events to all subscribers
* that need it.
* This avoids two problems:
* -- After getting a subscription, we should not send the first event
* until after our reply is fully queued to be sent back,
* -- Possible stack depth or infinite recursion issues.
*/
void event_send_all_later(struct upnp_wps_device_sm *sm)
{
/*
* The exact time in the future isn't too important. Waiting a bit
* might let us do several together.
*/
if (sm->event_send_all_queued)
return;
sm->event_send_all_queued = 1;
eloop_register_timeout(EVENT_DELAY_SECONDS, EVENT_DELAY_MSEC,
event_send_all_later_handler, NULL, sm);
}
/* event_send_stop_all -- cleanup */
void event_send_stop_all(struct upnp_wps_device_sm *sm)
{
if (sm->event_send_all_queued)
eloop_cancel_timeout(event_send_all_later_handler, NULL, sm);
sm->event_send_all_queued = 0;
}
/**
* event_add - Add a new event to a queue
* @s: Subscription
* @data: Event data (is copied; caller retains ownership)
* @probereq: Whether this is a Probe Request event
* Returns: 0 on success, -1 on error, 1 on max event queue limit reached
*/
int event_add(struct subscription *s, const struct wpabuf *data, int probereq)
{
struct wps_event_ *e;
unsigned int len;
len = dl_list_len(&s->event_queue);
if (len >= MAX_EVENTS_QUEUED) {
wpa_printf(MSG_DEBUG, "WPS UPnP: Too many events queued for "
"subscriber %p", s);
if (probereq)
return 1;
/* Drop oldest entry to allow EAP event to be stored. */
e = event_dequeue(s);
if (!e)
return 1;
event_delete(e);
}
if (s->last_event_failed && probereq && len > 0) {
/*
* Avoid queuing frames for subscribers that may have left
* without unsubscribing.
*/
wpa_printf(MSG_DEBUG, "WPS UPnP: Do not queue more Probe "
"Request frames for subscription %p since last "
"delivery failed", s);
return -1;
}
e = os_zalloc(sizeof(*e));
if (e == NULL)
return -1;
dl_list_init(&e->list);
e->s = s;
e->data = wpabuf_dup(data);
if (e->data == NULL) {
os_free(e);
return -1;
}
e->subscriber_sequence = s->next_subscriber_sequence++;
if (s->next_subscriber_sequence == 0)
s->next_subscriber_sequence++;
wpa_printf(MSG_DEBUG, "WPS UPnP: Queue event %p for subscriber %p "
"(queue len %u)", e, s, len + 1);
dl_list_add_tail(&s->event_queue, &e->list);
event_send_all_later(s->sm);
return 0;
}