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