wps_er_ssdp.c

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/*
 * Wi-Fi Protected Setup - External Registrar (SSDP)
 * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "uuid.h"
#include "eloop.h"
#include "wps_i.h"
#include "wps_upnp.h"
#include "wps_upnp_i.h"
#include "wps_er.h"


static void wps_er_ssdp_rx(int sd, void *eloop_ctx, void *sock_ctx)
{
        struct wps_er *er = eloop_ctx;
        struct sockaddr_in addr; /* client address */
        socklen_t addr_len;
        int nread;
        char buf[MULTICAST_MAX_READ], *pos, *pos2, *start;
        int wfa = 0, byebye = 0;
        int max_age = -1;
        char *location = NULL;
        u8 uuid[WPS_UUID_LEN];

        addr_len = sizeof(addr);
        nread = recvfrom(sd, buf, sizeof(buf) - 1, 0,
                         (struct sockaddr *) &addr, &addr_len);
        if (nread <= 0)
                return;
        buf[nread] = '\0';

        wpa_printf(MSG_DEBUG, "WPS ER: Received SSDP from %s",
                   inet_ntoa(addr.sin_addr));
        wpa_hexdump_ascii(MSG_MSGDUMP, "WPS ER: Received SSDP contents",
                          (u8 *) buf, nread);

        if (sd == er->multicast_sd) {
                /* Reply to M-SEARCH */
                if (os_strncmp(buf, "HTTP/1.1 200 OK", 15) != 0)
                        return; /* unexpected response header */
        } else {
                /* Unsolicited message (likely NOTIFY or M-SEARCH) */
                if (os_strncmp(buf, "NOTIFY ", 7) != 0)
                        return; /* only process notifications */
        }

        os_memset(uuid, 0, sizeof(uuid));

        for (start = buf; start && *start; start = pos) {
                pos = os_strchr(start, '\n');
                if (pos) {
                        if (pos[-1] == '\r')
                                pos[-1] = '\0';
                        *pos++ = '\0';
                }
                if (os_strstr(start, "schemas-wifialliance-org:device:"
                              "WFADevice:1"))
                        wfa = 1;
                if (os_strstr(start, "schemas-wifialliance-org:service:"
                              "WFAWLANConfig:1"))
                        wfa = 1;
                if (os_strncasecmp(start, "LOCATION:", 9) == 0) {
                        start += 9;
                        while (*start == ' ')
                                start++;
                        location = start;
                } else if (os_strncasecmp(start, "NTS:", 4) == 0) {
                        if (os_strstr(start, "ssdp:byebye"))
                                byebye = 1;
                } else if (os_strncasecmp(start, "CACHE-CONTROL:", 14) == 0) {
                        start += 9;
                        while (*start == ' ')
                                start++;
                        pos2 = os_strstr(start, "max-age=");
                        if (pos2 == NULL)
                                continue;
                        pos2 += 8;
                        max_age = atoi(pos2);
                } else if (os_strncasecmp(start, "USN:", 4) == 0) {
                        start += 4;
                        pos2 = os_strstr(start, "uuid:");
                        if (pos2) {
                                pos2 += 5;
                                while (*pos2 == ' ')
                                        pos2++;
                                if (uuid_str2bin(pos2, uuid) < 0) {
                                        wpa_printf(MSG_DEBUG, "WPS ER: "
                                                   "Invalid UUID in USN: %s",
                                                   pos2);
                                        return;
                                }
                        }
                }
        }

        if (!wfa)
                return; /* Not WPS advertisement/reply */

        if (byebye) {
                wps_er_ap_remove(er, &addr.sin_addr);
                return;
        }

        if (!location)
                return; /* Unknown location */

        if (max_age < 1)
                return; /* No max-age reported */

        wpa_printf(MSG_DEBUG, "WPS ER: AP discovered: %s "
                   "(packet source: %s  max-age: %d)",
                   location, inet_ntoa(addr.sin_addr), max_age);

        wps_er_ap_add(er, uuid, &addr.sin_addr, location, max_age);
}


void wps_er_send_ssdp_msearch(struct wps_er *er)
{
        struct wpabuf *msg;
        struct sockaddr_in dest;

        msg = wpabuf_alloc(500);
        if (msg == NULL)
                return;

        wpabuf_put_str(msg,
                       "M-SEARCH * HTTP/1.1\r\n"
                       "HOST: 239.255.255.250:1900\r\n"
                       "MAN: \"ssdp:discover\"\r\n"
                       "MX: 3\r\n"
                       "ST: urn:schemas-wifialliance-org:device:WFADevice:1"
                       "\r\n"
                       "\r\n");

        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(er->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
                   (struct sockaddr *) &dest, sizeof(dest)) < 0)
                wpa_printf(MSG_DEBUG, "WPS ER: M-SEARCH sendto failed: "
                           "%d (%s)", errno, strerror(errno));

        wpabuf_free(msg);
}


int wps_er_ssdp_init(struct wps_er *er)
{
        if (add_ssdp_network(er->ifname))
                return -1;

        er->multicast_sd = ssdp_open_multicast_sock(er->ip_addr);
        if (er->multicast_sd < 0)
                return -1;

        er->ssdp_sd = ssdp_listener_open();
        if (er->ssdp_sd < 0)
                return -1;

        if (eloop_register_sock(er->multicast_sd, EVENT_TYPE_READ,
                                wps_er_ssdp_rx, er, NULL) ||
            eloop_register_sock(er->ssdp_sd, EVENT_TYPE_READ,
                                wps_er_ssdp_rx, er, NULL))
                return -1;

        wps_er_send_ssdp_msearch(er);

        return 0;
}


void wps_er_ssdp_deinit(struct wps_er *er)
{
        if (er->multicast_sd >= 0) {
                eloop_unregister_sock(er->multicast_sd, EVENT_TYPE_READ);
                close(er->multicast_sd);
        }
        if (er->ssdp_sd >= 0) {
                eloop_unregister_sock(er->ssdp_sd, EVENT_TYPE_READ);
                close(er->ssdp_sd);
        }
}