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 
wps_er_ssdp_rx(int sd,void * eloop_ctx,void * sock_ctx)20 static 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 
wps_er_send_ssdp_msearch(struct wps_er * er)127 void 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 
wps_er_ssdp_init(struct wps_er * er)159 int 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 
wps_er_ssdp_deinit(struct wps_er * er)195 void 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