wps_upnp_ssdp.c

最新的Host AP 新添加了许多pcmcia 的驱动

/*
 * UPnP SSDP for WPS
 * Copyright (c) 2000-2003 Intel Corporation
 * Copyright (c) 2006-2007 Sony Corporation
 * Copyright (c) 2008-2009 Atheros Communications
 * Copyright (c) 2009, Jouni Malinen <[e-mail]>
 *
 * See wps_upnp.c for more details on licensing and code history.
 */

#include "includes.h"

#include <fcntl.h>
#include <sys/ioctl.h>
#include <net/route.h>

#include "common.h"
#include "uuid.h"
#include "eloop.h"
#include "wps.h"
#include "wps_upnp.h"
#include "wps_upnp_i.h"

#define UPNP_CACHE_SEC (UPNP_CACHE_SEC_MIN + 1) /* cache time we use */
#define UPNP_CACHE_SEC_MIN 1800 /* min cachable time per UPnP standard */
#define UPNP_ADVERTISE_REPEAT 2 /* no more than 3 */
#define MULTICAST_MAX_READ 1600 /* max bytes we'll read for UPD request */
#define MAX_MSEARCH 20          /* max simultaneous M-SEARCH replies ongoing */
#define SSDP_TARGET  "239.0.0.0"
#define SSDP_NETMASK "255.0.0.0"


/* Check tokens for equality, where tokens consist of letters, digits,
 * underscore and hyphen, and are matched case insensitive.
 */
static int token_eq(const char *s1, const char *s2)
{
	int c1;
	int c2;
	int end1 = 0;
	int end2 = 0;
	for (;;) {
		c1 = *s1++;
		c2 = *s2++;
		if (isalpha(c1) && isupper(c1))
			c1 = tolower(c1);
		if (isalpha(c2) && isupper(c2))
			c2 = tolower(c2);
		end1 = !(isalnum(c1) || c1 == '_' || c1 == '-');
		end2 = !(isalnum(c2) || c2 == '_' || c2 == '-');
		if (end1 || end2 || c1 != c2)
			break;
	}
	return end1 && end2; /* reached end of both words? */
}


/* Return length of token (see above for definition of token) */
static int token_length(const char *s)
{
	const char *begin = s;
	for (;; s++) {
		int c = *s;
		int end = !(isalnum(c) || c == '_' || c == '-');
		if (end)
			break;
	}
	return s - begin;
}


/* return length of interword separation.
 * This accepts only spaces/tabs and thus will not traverse a line
 * or buffer ending.
 */
static int word_separation_length(const char *s)
{
	const char *begin = s;
	for (;; s++) {
		int c = *s;
		if (c == ' ' || c == '\t')
			continue;
		break;
	}
	return s - begin;
}


/* No. of chars through (including) end of line */
static int line_length(const char *l)
{
	const char *lp = l;
	while (*lp && *lp != '\n')
		lp++;
	if (*lp == '\n')
		lp++;
	return lp - l;
}


/* No. of chars excluding trailing whitespace */
static int line_length_stripped(const char *l)
{
	const char *lp = l + line_length(l);
	while (lp > l && !isgraph(lp[-1]))
		lp--;
	return lp - l;
}


static int str_starts(const char *str, const char *start)
{
	return os_strncmp(str, start, os_strlen(start)) == 0;
}


/***************************************************************************
 * Advertisements.
 * These are multicast to the world to tell them we are here.
 * The individual packets are spread out in time to limit loss,
 * and then after a much longer period of time the whole sequence
 * is repeated again (for NOTIFYs only).
 **************************************************************************/

/**
 * next_advertisement - Build next message and advance the state machine
 * @a: Advertisement state
 * @islast: Buffer for indicating whether this is the last message (= 1)
 * Returns: The new message (caller is responsible for freeing this)
 *
 * Note: next_advertisement is shared code with msearchreply_* functions
 */
static struct wpabuf *
next_advertisement(struct advertisement_state_machine *a, int *islast)
{
	struct wpabuf *msg;
	char *NTString = "";
	char uuid_string[80];

	*islast = 0;
	uuid_bin2str(a->sm->wps->uuid, uuid_string, sizeof(uuid_string));
	msg = wpabuf_alloc(800); /* more than big enough */
	if (msg == NULL)
		goto fail;
	switch (a->type) {
	case ADVERTISE_UP:
	case ADVERTISE_DOWN:
		NTString = "NT";
		wpabuf_put_str(msg, "NOTIFY * HTTP/1.1\r\n");
		wpabuf_printf(msg, "HOST: %s:%d\r\n",
			      UPNP_MULTICAST_ADDRESS, UPNP_MULTICAST_PORT);
		wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
			      UPNP_CACHE_SEC);
		wpabuf_printf(msg, "NTS: %s\r\n",
			      (a->type == ADVERTISE_UP ?
			       "ssdp:alive" : "ssdp:byebye"));
		break;
	case MSEARCH_REPLY:
		NTString = "ST";
		wpabuf_put_str(msg, "HTTP/1.1 200 OK\r\n");
		wpabuf_printf(msg, "CACHE-CONTROL: max-age=%d\r\n",
			      UPNP_CACHE_SEC);

		wpabuf_put_str(msg, "DATE: ");
		format_date(msg);
		wpabuf_put_str(msg, "\r\n");

		wpabuf_put_str(msg, "EXT:\r\n");
		break;
	}

	if (a->type != ADVERTISE_DOWN) {
		/* Where others may get our XML files from */
		wpabuf_printf(msg, "LOCATION: http://%s:%d/%s\r\n",
			      a->sm->ip_addr_text, a->sm->web_port,
			      UPNP_WPS_DEVICE_XML_FILE);
	}

	/* The SERVER line has three comma-separated fields:
	 *      operating system / version
	 *      upnp version
	 *      software package / version
	 * However, only the UPnP version is really required, the
	 * others can be place holders... for security reasons
	 * it is better to NOT provide extra information.
	 */
	wpabuf_put_str(msg, "SERVER: Unspecified, UPnP/1.0, Unspecified\r\n");

	switch (a->state / UPNP_ADVERTISE_REPEAT) {
	case 0:
		wpabuf_printf(msg, "%s: upnp:rootdevice\r\n", NTString);
		wpabuf_printf(msg, "USN: uuid:%s::upnp:rootdevice\r\n",
			      uuid_string);
		break;
	case 1:
		wpabuf_printf(msg, "%s: uuid:%s\r\n", NTString, uuid_string);
		wpabuf_printf(msg, "USN: uuid:%s\r\n", uuid_string);
		break;
	case 2:
		wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:device:"
			      "WFADevice:1\r\n", NTString);
		wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
			      "org:device:WFADevice:1\r\n", uuid_string);
		break;
	case 3:
		wpabuf_printf(msg, "%s: urn:schemas-wifialliance-org:service:"
			      "WFAWLANConfig:1\r\n", NTString);
		wpabuf_printf(msg, "USN: uuid:%s::urn:schemas-wifialliance-"
			      "org:service:WFAWLANConfig:1\r\n", uuid_string);
		break;
	}
	wpabuf_put_str(msg, "\r\n");

	if (a->state + 1 >= 4 * UPNP_ADVERTISE_REPEAT)
		*islast = 1;

	return msg;

fail:
	wpabuf_free(msg);
	return NULL;
}


static void advertisement_state_machine_handler(void *eloop_data,
						void *user_ctx);


/**
 * advertisement_state_machine_stop - Stop SSDP advertisements
 * @sm: WPS UPnP state machine from upnp_wps_device_init()
 */
void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm)
{
	eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm);
}


static void advertisement_state_machine_handler(void *eloop_data,
						void *user_ctx)
{
	struct upnp_wps_device_sm *sm = user_ctx;
	struct advertisement_state_machine *a = &sm->advertisement;
	struct wpabuf *msg;
	int next_timeout_msec = 100;
	int next_timeout_sec = 0;
	struct sockaddr_in dest;
	int islast = 0;

	/*
	 * Each is sent twice (in case lost) w/ 100 msec delay between;
	 * spec says no more than 3 times.
	 * One pair for rootdevice, one pair for uuid, and a pair each for
	 * each of the two urns.
	 * The entire sequence must be repeated before cache control timeout
	 * (which  is min  1800 seconds),
	 * recommend random portion of half of the advertised cache control age
	 * to ensure against loss... perhaps 1800/4 + rand*1800/4 ?
	 * Delay random interval < 100 msec prior to initial sending.
	 * TTL of 4
	 */

	wpa_printf(MSG_MSGDUMP, "WPS UPnP: Advertisement state=%d", a->state);
	msg = next_advertisement(a, &islast);
	if (msg == NULL)
		return;

	os_memset(&dest, 0, sizeof(dest));
	dest.sin_family = AF_INET;
	dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
	dest.sin_port = htons(UPNP_MULTICAST_PORT);

	if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
		   (struct sockaddr *) &dest, sizeof(dest)) == -1) {
		wpa_printf(MSG_ERROR, "WPS UPnP: Advertisement sendto failed:"
			   "%d (%s)", errno, strerror(errno));
		next_timeout_msec = 0;
		next_timeout_sec = 10; /* ... later */
	} else if (islast) {
		a->state = 0; /* wrap around */
		if (a->type == ADVERTISE_DOWN) {
			wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_DOWN->UP");
			a->type = ADVERTISE_UP;
			/* do it all over again right away */
		} else {
			u16 r;
			/*
			 * Start over again after a long timeout
			 * (see notes above)
			 */
			next_timeout_msec = 0;
			os_get_random((void *) &r, sizeof(r));
			next_timeout_sec = UPNP_CACHE_SEC / 4 +
				(((UPNP_CACHE_SEC / 4) * r) >> 16);
			sm->advertise_count++;
			wpa_printf(MSG_DEBUG, "WPS UPnP: ADVERTISE_UP (#%u); "
				   "next in %d sec",
				   sm->advertise_count, next_timeout_sec);
		}
	} else {
		a->state++;
	}

	wpabuf_free(msg);

	eloop_register_timeout(next_timeout_sec, next_timeout_msec,
			       advertisement_state_machine_handler, NULL, sm);
}


/**
 * advertisement_state_machine_start - Start SSDP advertisements
 * @sm: WPS UPnP state machine from upnp_wps_device_init()
 * Returns: 0 on success, -1 on failure
 */
int advertisement_state_machine_start(struct upnp_wps_device_sm *sm)
{
	struct advertisement_state_machine *a = &sm->advertisement;
	int next_timeout_msec;

	advertisement_state_machine_stop(sm);

	/*
	 * Start out advertising down, this automatically switches
	 * to advertising up which signals our restart.
	 */
	a->type = ADVERTISE_DOWN;
	a->state = 0;
	a->sm = sm;
	/* (other fields not used here) */

	/* First timeout should be random interval < 100 msec */
	next_timeout_msec = (100 * (os_random() & 0xFF)) >> 8;
	return eloop_register_timeout(0, next_timeout_msec,
				      advertisement_state_machine_handler,
				      NULL, sm);
}


/***************************************************************************
 * M-SEARCH replies
 * These are very similar to the multicast advertisements, with some
 * small changes in data content; and they are sent (UDP) to a specific
 * unicast address instead of multicast.
 * They are sent in response to a UDP M-SEARCH packet.
 **************************************************************************/

static void msearchreply_state_machine_handler(void *eloop_data,
					       void *user_ctx);


/**
 * msearchreply_state_machine_stop - Stop M-SEARCH reply state machine
 * @a: Selected advertisement/reply state
 */
void msearchreply_state_machine_stop(struct advertisement_state_machine *a)
{
	struct upnp_wps_device_sm *sm = a->sm;
	wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop");
	if (a->next == a) {
		sm->msearch_replies = NULL;
	} else {
		if (sm->msearch_replies == a)
			sm->msearch_replies = a->next;
		a->next->prev = a->prev;
		a->prev->next = a->next;
	}
	os_free(a);
	sm->n_msearch_replies--;
}


static void msearchreply_state_machine_handler(void *eloop_data,
					       void *user_ctx)
{
	struct advertisement_state_machine *a = user_ctx;
	struct upnp_wps_device_sm *sm = a->sm;
	struct wpabuf *msg;
	int next_timeout_msec = 100;
	int next_timeout_sec = 0;
	int islast = 0;

	/*
	 * Each response is sent twice (in case lost) w/ 100 msec delay
	 * between; spec says no more than 3 times.
	 * One pair for rootdevice, one pair for uuid, and a pair each for
	 * each of the two urns.
	 */

	/* TODO: should only send the requested response types */

	wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply state=%d (%s:%d)",
		   a->state, inet_ntoa(a->client.sin_addr),
		   ntohs(a->client.sin_port));
	msg = next_advertisement(a, &islast);
	if (msg == NULL)
		return;

	/*
	 * Send it on the multicast socket to avoid having to set up another
	 * socket.
	 */
	if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
		   (struct sockaddr *) &a->client, sizeof(a->client)) < 0) {
		wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply sendto "
			   "errno %d (%s) for %s:%d",
			   errno, strerror(errno),
			   inet_ntoa(a->client.sin_addr),
			   ntohs(a->client.sin_port));
		/* Ignore error and hope for the best */
	}
	wpabuf_free(msg);
	if (islast) {
		wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply done");
		msearchreply_state_machine_stop(a);
		return;
	}
	a->state++;

	wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH reply in %d.%03d sec",
		   next_timeout_sec, next_timeout_msec);
	eloop_register_timeout(next_timeout_sec, next_timeout_msec,
			       msearchreply_state_machine_handler, sm, a);
}


/**
 * msearchreply_state_machine_start - Reply to M-SEARCH discovery request
 * @sm: WPS UPnP state machine from upnp_wps_device_init()
 * @client: Client address
 * @mx: Maximum delay in seconds
 *
 * Use TTL of 4 (this was done when socket set up).
 * A response should be given in randomized portion of min(MX,120) seconds
 *
 * UPnP-arch-DeviceArchitecture, 1.2.3:
 * To be found, a device must send a UDP response to the source IP address and
 * port that sent the request to the multicast channel. Devices respond if the
 * ST header of the M-SEARCH request is "ssdp:all", "upnp:rootdevice", "uuid:"
 * followed by a UUID that exactly matches one advertised by the device.
 */
static void msearchreply_state_machine_start(struct upnp_wps_device_sm *sm,
					     struct sockaddr_in *client,
					     int mx)
{
	struct advertisement_state_machine *a;