1/*
2 * Wi-Fi Protected Setup - External Registrar (SSDP)
3 * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9#include "includes.h"
10
11#include "common.h"
12#include "uuid.h"
13#include "eloop.h"
14#include "wps_i.h"
15#include "wps_upnp.h"
16#include "wps_upnp_i.h"
17#include "wps_er.h"
18
19
20static void wps_er_ssdp_rx(int sd, void *eloop_ctx, void *sock_ctx)
21{
22	struct wps_er *er = eloop_ctx;
23	struct sockaddr_in addr; /* client address */
24	socklen_t addr_len;
25	int nread;
26	char buf[MULTICAST_MAX_READ], *pos, *pos2, *start;
27	int wfa = 0, byebye = 0;
28	int max_age = -1;
29	char *location = NULL;
30	u8 uuid[WPS_UUID_LEN];
31
32	addr_len = sizeof(addr);
33	nread = recvfrom(sd, buf, sizeof(buf) - 1, 0,
34			 (struct sockaddr *) &addr, &addr_len);
35	if (nread <= 0)
36		return;
37	buf[nread] = '\0';
38	if (er->filter_addr.s_addr &&
39	    er->filter_addr.s_addr != addr.sin_addr.s_addr)
40		return;
41
42	wpa_printf(MSG_DEBUG, "WPS ER: Received SSDP from %s",
43		   inet_ntoa(addr.sin_addr));
44	wpa_hexdump_ascii(MSG_MSGDUMP, "WPS ER: Received SSDP contents",
45			  (u8 *) buf, nread);
46
47	if (sd == er->multicast_sd) {
48		/* Reply to M-SEARCH */
49		if (os_strncmp(buf, "HTTP/1.1 200 OK", 15) != 0)
50			return; /* unexpected response header */
51	} else {
52		/* Unsolicited message (likely NOTIFY or M-SEARCH) */
53		if (os_strncmp(buf, "NOTIFY ", 7) != 0)
54			return; /* only process notifications */
55	}
56
57	os_memset(uuid, 0, sizeof(uuid));
58
59	for (start = buf; start && *start; start = pos) {
60		pos = os_strchr(start, '\n');
61		if (pos) {
62			if (pos[-1] == '\r')
63				pos[-1] = '\0';
64			*pos++ = '\0';
65		}
66		if (os_strstr(start, "schemas-wifialliance-org:device:"
67			      "WFADevice:1"))
68			wfa = 1;
69		if (os_strstr(start, "schemas-wifialliance-org:service:"
70			      "WFAWLANConfig:1"))
71			wfa = 1;
72		if (os_strncasecmp(start, "LOCATION:", 9) == 0) {
73			start += 9;
74			while (*start == ' ')
75				start++;
76			location = start;
77		} else if (os_strncasecmp(start, "NTS:", 4) == 0) {
78			if (os_strstr(start, "ssdp:byebye"))
79				byebye = 1;
80		} else if (os_strncasecmp(start, "CACHE-CONTROL:", 14) == 0) {
81			start += 14;
82			pos2 = os_strstr(start, "max-age=");
83			if (pos2 == NULL)
84				continue;
85			pos2 += 8;
86			max_age = atoi(pos2);
87		} else if (os_strncasecmp(start, "USN:", 4) == 0) {
88			start += 4;
89			pos2 = os_strstr(start, "uuid:");
90			if (pos2) {
91				pos2 += 5;
92				while (*pos2 == ' ')
93					pos2++;
94				if (uuid_str2bin(pos2, uuid) < 0) {
95					wpa_printf(MSG_DEBUG, "WPS ER: "
96						   "Invalid UUID in USN: %s",
97						   pos2);
98					return;
99				}
100			}
101		}
102	}
103
104	if (!wfa)
105		return; /* Not WPS advertisement/reply */
106
107	if (byebye) {
108		wps_er_ap_cache_settings(er, &addr.sin_addr);
109		wps_er_ap_remove(er, &addr.sin_addr);
110		return;
111	}
112
113	if (!location)
114		return; /* Unknown location */
115
116	if (max_age < 1)
117		return; /* No max-age reported */
118
119	wpa_printf(MSG_DEBUG, "WPS ER: AP discovered: %s "
120		   "(packet source: %s  max-age: %d)",
121		   location, inet_ntoa(addr.sin_addr), max_age);
122
123	wps_er_ap_add(er, uuid, &addr.sin_addr, location, max_age);
124}
125
126
127void wps_er_send_ssdp_msearch(struct wps_er *er)
128{
129	struct wpabuf *msg;
130	struct sockaddr_in dest;
131
132	msg = wpabuf_alloc(500);
133	if (msg == NULL)
134		return;
135
136	wpabuf_put_str(msg,
137		       "M-SEARCH * HTTP/1.1\r\n"
138		       "HOST: 239.255.255.250:1900\r\n"
139		       "MAN: \"ssdp:discover\"\r\n"
140		       "MX: 3\r\n"
141		       "ST: urn:schemas-wifialliance-org:device:WFADevice:1"
142		       "\r\n"
143		       "\r\n");
144
145	os_memset(&dest, 0, sizeof(dest));
146	dest.sin_family = AF_INET;
147	dest.sin_addr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
148	dest.sin_port = htons(UPNP_MULTICAST_PORT);
149
150	if (sendto(er->multicast_sd, wpabuf_head(msg), wpabuf_len(msg), 0,
151		   (struct sockaddr *) &dest, sizeof(dest)) < 0)
152		wpa_printf(MSG_DEBUG, "WPS ER: M-SEARCH sendto failed: "
153			   "%d (%s)", errno, strerror(errno));
154
155	wpabuf_free(msg);
156}
157
158
159int wps_er_ssdp_init(struct wps_er *er)
160{
161	if (add_ssdp_network(er->ifname)) {
162		wpa_printf(MSG_INFO, "WPS ER: Failed to add routing entry for "
163			   "SSDP");
164		return -1;
165	}
166
167	er->multicast_sd = ssdp_open_multicast_sock(er->ip_addr,
168						    er->forced_ifname ?
169						    er->ifname : NULL);
170	if (er->multicast_sd < 0) {
171		wpa_printf(MSG_INFO, "WPS ER: Failed to open multicast socket "
172			   "for SSDP");
173		return -1;
174	}
175
176	er->ssdp_sd = ssdp_listener_open();
177	if (er->ssdp_sd < 0) {
178		wpa_printf(MSG_INFO, "WPS ER: Failed to open SSDP listener "
179			   "socket");
180		return -1;
181	}
182
183	if (eloop_register_sock(er->multicast_sd, EVENT_TYPE_READ,
184				wps_er_ssdp_rx, er, NULL) ||
185	    eloop_register_sock(er->ssdp_sd, EVENT_TYPE_READ,
186				wps_er_ssdp_rx, er, NULL))
187		return -1;
188
189	wps_er_send_ssdp_msearch(er);
190
191	return 0;
192}
193
194
195void wps_er_ssdp_deinit(struct wps_er *er)
196{
197	if (er->multicast_sd >= 0) {
198		eloop_unregister_sock(er->multicast_sd, EVENT_TYPE_READ);
199		close(er->multicast_sd);
200	}
201	if (er->ssdp_sd >= 0) {
202		eloop_unregister_sock(er->ssdp_sd, EVENT_TYPE_READ);
203		close(er->ssdp_sd);
204	}
205}
206