remove @EAP_LDFLAGS@, no longer exists
[mech_eap.orig] / libeap / src / wps / wps_upnp_ssdp.c
diff --git a/libeap/src/wps/wps_upnp_ssdp.c b/libeap/src/wps/wps_upnp_ssdp.c
new file mode 100644 (file)
index 0000000..c1b2193
--- /dev/null
@@ -0,0 +1,930 @@
+/*
+ * 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 <j@w1.fi>
+ *
+ * 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 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 upnp_wps_device_sm *sm,
+                  struct advertisement_state_machine *a, int *islast)
+{
+       struct wpabuf *msg;
+       char *NTString = "";
+       char uuid_string[80];
+
+       *islast = 0;
+       uuid_bin2str(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",
+                             sm->ip_addr_text, 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()
+ * @send_byebye: Send byebye advertisement messages immediately
+ */
+void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm,
+                                     int send_byebye)
+{
+       struct advertisement_state_machine *a = &sm->advertisement;
+       int islast = 0;
+       struct wpabuf *msg;
+       struct sockaddr_in dest;
+
+       eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm);
+       if (!send_byebye || sm->multicast_sd < 0)
+               return;
+
+       a->type = ADVERTISE_DOWN;
+       a->state = 0;
+
+       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);
+
+       while (!islast) {
+               msg = next_advertisement(sm, a, &islast);
+               if (msg == NULL)
+                       break;
+               if (sendto(sm->multicast_sd, wpabuf_head(msg), wpabuf_len(msg),
+                          0, (struct sockaddr *) &dest, sizeof(dest)) < 0) {
+                       wpa_printf(MSG_INFO, "WPS UPnP: Advertisement sendto "
+                                  "failed: %d (%s)", errno, strerror(errno));
+               }
+               wpabuf_free(msg);
+               a->state++;
+       }
+}
+
+
+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(sm, 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, 0);
+
+       /*
+        * Start out advertising down, this automatically switches
+        * to advertising up which signals our restart.
+        */
+       a->type = ADVERTISE_DOWN;
+       a->state = 0;
+       /* (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.
+ **************************************************************************/
+
+/**
+ * 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)
+{
+       wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop");
+       dl_list_del(&a->list);
+       os_free(a);
+}
+
+
+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 = eloop_data;
+       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(sm, 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;
+       int next_timeout_sec;
+       int next_timeout_msec;
+       int replies;
+
+       replies = dl_list_len(&sm->msearch_replies);
+       wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d "
+                  "outstanding)", replies);
+       if (replies >= MAX_MSEARCH) {
+               wpa_printf(MSG_INFO, "WPS UPnP: Too many outstanding "
+                          "M-SEARCH replies");
+               return;
+       }
+
+       a = os_zalloc(sizeof(*a));
+       if (a == NULL)
+               return;
+       a->type = MSEARCH_REPLY;
+       a->state = 0;
+       os_memcpy(&a->client, client, sizeof(*client));
+       /* Wait time depending on MX value */
+       next_timeout_msec = (1000 * mx * (os_random() & 0xFF)) >> 8;
+       next_timeout_sec = next_timeout_msec / 1000;
+       next_timeout_msec = next_timeout_msec % 1000;
+       if (eloop_register_timeout(next_timeout_sec, next_timeout_msec,
+                                  msearchreply_state_machine_handler, sm,
+                                  a)) {
+               /* No way to recover (from malloc failure) */
+               goto fail;
+       }
+       /* Remember for future cleanup */
+       dl_list_add(&sm->msearch_replies, &a->list);
+       return;
+
+fail:
+       wpa_printf(MSG_INFO, "WPS UPnP: M-SEARCH reply failure!");
+       eloop_cancel_timeout(msearchreply_state_machine_handler, sm, a);
+       os_free(a);
+}
+
+
+/**
+ * ssdp_parse_msearch - Process a received M-SEARCH
+ * @sm: WPS UPnP state machine from upnp_wps_device_init()
+ * @client: Client address
+ * @data: NULL terminated M-SEARCH message
+ *
+ * Given that we have received a header w/ M-SEARCH, act upon it
+ *
+ * Format of M-SEARCH (case insensitive!):
+ *
+ * First line must be:
+ *      M-SEARCH * HTTP/1.1
+ * Other lines in arbitrary order:
+ *      HOST:239.255.255.250:1900
+ *      ST:<varies -- must match>
+ *      MAN:"ssdp:discover"
+ *      MX:<varies>
+ *
+ * It should be noted that when Microsoft Vista is still learning its IP
+ * address, it sends out host lines like: HOST:[FF02::C]:1900
+ */
+static void ssdp_parse_msearch(struct upnp_wps_device_sm *sm,
+                              struct sockaddr_in *client, const char *data)
+{
+#ifndef CONFIG_NO_STDOUT_DEBUG
+       const char *start = data;
+#endif /* CONFIG_NO_STDOUT_DEBUG */
+       const char *end;
+       int got_host = 0;
+       int got_st = 0, st_match = 0;
+       int got_man = 0;
+       int got_mx = 0;
+       int mx = 0;
+
+       /*
+        * Skip first line M-SEARCH * HTTP/1.1
+        * (perhaps we should check remainder of the line for syntax)
+        */
+       data += line_length(data);
+
+       /* Parse remaining lines */
+       for (; *data != '\0'; data += line_length(data)) {
+               end = data + line_length_stripped(data);
+               if (token_eq(data, "host")) {
+                       /* The host line indicates who the packet
+                        * is addressed to... but do we really care?
+                        * Note that Microsoft sometimes does funny
+                        * stuff with the HOST: line.
+                        */
+#if 0   /* could be */
+                       data += token_length(data);
+                       data += word_separation_length(data);
+                       if (*data != ':')
+                               goto bad;
+                       data++;
+                       data += word_separation_length(data);
+                       /* UPNP_MULTICAST_ADDRESS */
+                       if (!str_starts(data, "239.255.255.250"))
+                               goto bad;
+                       data += os_strlen("239.255.255.250");
+                       if (*data == ':') {
+                               if (!str_starts(data, ":1900"))
+                                       goto bad;
+                       }
+#endif  /* could be */
+                       got_host = 1;
+                       continue;
+               } else if (token_eq(data, "st")) {
+                       /* There are a number of forms; we look
+                        * for one that matches our case.
+                        */
+                       got_st = 1;
+                       data += token_length(data);
+                       data += word_separation_length(data);
+                       if (*data != ':')
+                               continue;
+                       data++;
+                       data += word_separation_length(data);
+                       if (str_starts(data, "ssdp:all")) {
+                               st_match = 1;
+                               continue;
+                       }
+                       if (str_starts(data, "upnp:rootdevice")) {
+                               st_match = 1;
+                               continue;
+                       }
+                       if (str_starts(data, "uuid:")) {
+                               char uuid_string[80];
+                               data += os_strlen("uuid:");
+                               uuid_bin2str(sm->wps->uuid, uuid_string,
+                                            sizeof(uuid_string));
+                               if (str_starts(data, uuid_string))
+                                       st_match = 1;
+                               continue;
+                       }
+#if 0
+                       /* FIX: should we really reply to IGD string? */
+                       if (str_starts(data, "urn:schemas-upnp-org:device:"
+                                      "InternetGatewayDevice:1")) {
+                               st_match = 1;
+                               continue;
+                       }
+#endif
+                       if (str_starts(data, "urn:schemas-wifialliance-org:"
+                                      "service:WFAWLANConfig:1")) {
+                               st_match = 1;
+                               continue;
+                       }
+                       if (str_starts(data, "urn:schemas-wifialliance-org:"
+                                      "device:WFADevice:1")) {
+                               st_match = 1;
+                               continue;
+                       }
+                       continue;
+               } else if (token_eq(data, "man")) {
+                       data += token_length(data);
+                       data += word_separation_length(data);
+                       if (*data != ':')
+                               continue;
+                       data++;
+                       data += word_separation_length(data);
+                       if (!str_starts(data, "\"ssdp:discover\"")) {
+                               wpa_printf(MSG_DEBUG, "WPS UPnP: Unexpected "
+                                          "M-SEARCH man-field");
+                               goto bad;
+                       }
+                       got_man = 1;
+                       continue;
+               } else if (token_eq(data, "mx")) {
+                       data += token_length(data);
+                       data += word_separation_length(data);
+                       if (*data != ':')
+                               continue;
+                       data++;
+                       data += word_separation_length(data);
+                       mx = atol(data);
+                       got_mx = 1;
+                       continue;
+               }
+               /* ignore anything else */
+       }
+       if (!got_host || !got_st || !got_man || !got_mx || mx < 0) {
+               wpa_printf(MSG_DEBUG, "WPS UPnP: Invalid M-SEARCH: %d %d %d "
+                          "%d mx=%d", got_host, got_st, got_man, got_mx, mx);
+               goto bad;
+       }
+       if (!st_match) {
+               wpa_printf(MSG_DEBUG, "WPS UPnP: Ignored M-SEARCH (no ST "
+                          "match)");
+               return;
+       }
+       if (mx > 120)
+               mx = 120; /* UPnP-arch-DeviceArchitecture, 1.2.3 */
+       msearchreply_state_machine_start(sm, client, mx);
+       return;
+
+bad:
+       wpa_printf(MSG_INFO, "WPS UPnP: Failed to parse M-SEARCH");
+       wpa_printf(MSG_MSGDUMP, "WPS UPnP: M-SEARCH data:\n%s", start);
+}
+
+
+/* Listening for (UDP) discovery (M-SEARCH) packets */
+
+/**
+ * ssdp_listener_stop - Stop SSDP listered
+ * @sm: WPS UPnP state machine from upnp_wps_device_init()
+ *
+ * This function stops the SSDP listener that was started by calling
+ * ssdp_listener_start().
+ */
+void ssdp_listener_stop(struct upnp_wps_device_sm *sm)
+{
+       if (sm->ssdp_sd_registered) {
+               eloop_unregister_sock(sm->ssdp_sd, EVENT_TYPE_READ);
+               sm->ssdp_sd_registered = 0;
+       }
+
+       if (sm->ssdp_sd != -1) {
+               close(sm->ssdp_sd);
+               sm->ssdp_sd = -1;
+       }
+
+       eloop_cancel_timeout(msearchreply_state_machine_handler, sm,
+                            ELOOP_ALL_CTX);
+}
+
+
+static void ssdp_listener_handler(int sd, void *eloop_ctx, void *sock_ctx)
+{
+       struct upnp_wps_device_sm *sm = sock_ctx;
+       struct sockaddr_in addr; /* client address */
+       socklen_t addr_len;
+       int nread;
+       char buf[MULTICAST_MAX_READ], *pos;
+
+       addr_len = sizeof(addr);
+       nread = recvfrom(sm->ssdp_sd, buf, sizeof(buf) - 1, 0,
+                        (struct sockaddr *) &addr, &addr_len);
+       if (nread <= 0)
+               return;
+       buf[nread] = '\0'; /* need null termination for algorithm */
+
+       if (str_starts(buf, "NOTIFY ")) {
+               /*
+                * Silently ignore NOTIFYs to avoid filling debug log with
+                * unwanted messages.
+                */
+               return;
+       }
+
+       pos = os_strchr(buf, '\n');
+       if (pos)
+               *pos = '\0';
+       wpa_printf(MSG_MSGDUMP, "WPS UPnP: Received SSDP packet from %s:%d: "
+                  "%s", inet_ntoa(addr.sin_addr), ntohs(addr.sin_port), buf);
+       if (pos)
+               *pos = '\n';
+
+       /* Parse first line */
+       if (os_strncasecmp(buf, "M-SEARCH", os_strlen("M-SEARCH")) == 0 &&
+           !isgraph(buf[strlen("M-SEARCH")])) {
+               ssdp_parse_msearch(sm, &addr, buf);
+               return;
+       }
+
+       /* Ignore anything else */
+}
+
+
+int ssdp_listener_open(void)
+{
+       struct sockaddr_in addr;
+       struct ip_mreq mcast_addr;
+       int on = 1;
+       /* per UPnP spec, keep IP packet time to live (TTL) small */
+       unsigned char ttl = 4;
+       int sd;
+
+       sd = socket(AF_INET, SOCK_DGRAM, 0);
+       if (sd < 0)
+               goto fail;
+       if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
+               goto fail;
+       if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
+               goto fail;
+       os_memset(&addr, 0, sizeof(addr));
+       addr.sin_family = AF_INET;
+       addr.sin_addr.s_addr = htonl(INADDR_ANY);
+       addr.sin_port = htons(UPNP_MULTICAST_PORT);
+       if (bind(sd, (struct sockaddr *) &addr, sizeof(addr)))
+               goto fail;
+       os_memset(&mcast_addr, 0, sizeof(mcast_addr));
+       mcast_addr.imr_interface.s_addr = htonl(INADDR_ANY);
+       mcast_addr.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
+       if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
+                      (char *) &mcast_addr, sizeof(mcast_addr)))
+               goto fail;
+       if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
+                      &ttl, sizeof(ttl)))
+               goto fail;
+
+       return sd;
+
+fail:
+       if (sd >= 0)
+               close(sd);
+       return -1;
+}
+
+
+/**
+ * ssdp_listener_start - Set up for receiving discovery (UDP) packets
+ * @sm: WPS UPnP state machine from upnp_wps_device_init()
+ * Returns: 0 on success, -1 on failure
+ *
+ * The SSDP listener is stopped by calling ssdp_listener_stop().
+ */
+int ssdp_listener_start(struct upnp_wps_device_sm *sm)
+{
+       sm->ssdp_sd = ssdp_listener_open();
+
+       if (eloop_register_sock(sm->ssdp_sd, EVENT_TYPE_READ,
+                               ssdp_listener_handler, NULL, sm))
+               goto fail;
+       sm->ssdp_sd_registered = 1;
+       return 0;
+
+fail:
+       /* Error */
+       wpa_printf(MSG_ERROR, "WPS UPnP: ssdp_listener_start failed");
+       ssdp_listener_stop(sm);
+       return -1;
+}
+
+
+/**
+ * add_ssdp_network - Add routing entry for SSDP
+ * @net_if: Selected network interface name
+ * Returns: 0 on success, -1 on failure
+ *
+ * This function assures that the multicast address will be properly
+ * handled by Linux networking code (by a modification to routing tables).
+ * This must be done per network interface. It really only needs to be done
+ * once after booting up, but it does not hurt to call this more frequently
+ * "to be safe".
+ */
+int add_ssdp_network(const char *net_if)
+{
+#ifdef __linux__
+       int ret = -1;
+       int sock = -1;
+       struct rtentry rt;
+       struct sockaddr_in *sin;
+
+       if (!net_if)
+               goto fail;
+
+       os_memset(&rt, 0, sizeof(rt));
+       sock = socket(AF_INET, SOCK_DGRAM, 0);
+       if (sock < 0)
+               goto fail;
+
+       rt.rt_dev = (char *) net_if;
+       sin = aliasing_hide_typecast(&rt.rt_dst, struct sockaddr_in);
+       sin->sin_family = AF_INET;
+       sin->sin_port = 0;
+       sin->sin_addr.s_addr = inet_addr(SSDP_TARGET);
+       sin = aliasing_hide_typecast(&rt.rt_genmask, struct sockaddr_in);
+       sin->sin_family = AF_INET;
+       sin->sin_port = 0;
+       sin->sin_addr.s_addr = inet_addr(SSDP_NETMASK);
+       rt.rt_flags = RTF_UP;
+       if (ioctl(sock, SIOCADDRT, &rt) < 0) {
+               if (errno == EPERM) {
+                       wpa_printf(MSG_DEBUG, "add_ssdp_network: No "
+                                  "permissions to add routing table entry");
+                       /* Continue to allow testing as non-root */
+               } else if (errno != EEXIST) {
+                       wpa_printf(MSG_INFO, "add_ssdp_network() ioctl errno "
+                                  "%d (%s)", errno, strerror(errno));
+                       goto fail;
+               }
+       }
+
+       ret = 0;
+
+fail:
+       if (sock >= 0)
+               close(sock);
+
+       return ret;
+#else /* __linux__ */
+       return 0;
+#endif /* __linux__ */
+}
+
+
+int ssdp_open_multicast_sock(u32 ip_addr)
+{
+       int sd;
+        /* per UPnP-arch-DeviceArchitecture, 1. Discovery, keep IP packet
+         * time to live (TTL) small */
+       unsigned char ttl = 4;
+
+       sd = socket(AF_INET, SOCK_DGRAM, 0);
+       if (sd < 0)
+               return -1;
+
+#if 0   /* maybe ok if we sometimes block on writes */
+       if (fcntl(sd, F_SETFL, O_NONBLOCK) != 0)
+               return -1;
+#endif
+
+       if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_IF,
+                      &ip_addr, sizeof(ip_addr))) {
+               wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_IF) %x: "
+                          "%d (%s)", ip_addr, errno, strerror(errno));
+               return -1;
+       }
+       if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL,
+                      &ttl, sizeof(ttl))) {
+               wpa_printf(MSG_DEBUG, "WPS: setsockopt(IP_MULTICAST_TTL): "
+                          "%d (%s)", errno, strerror(errno));
+               return -1;
+       }
+
+#if 0   /* not needed, because we don't receive using multicast_sd */
+       {
+               struct ip_mreq mreq;
+               mreq.imr_multiaddr.s_addr = inet_addr(UPNP_MULTICAST_ADDRESS);
+               mreq.imr_interface.s_addr = ip_addr;
+               wpa_printf(MSG_DEBUG, "WPS UPnP: Multicast addr 0x%x if addr "
+                          "0x%x",
+                          mreq.imr_multiaddr.s_addr,
+                          mreq.imr_interface.s_addr);
+               if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq,
+                               sizeof(mreq))) {
+                       wpa_printf(MSG_ERROR,
+                                  "WPS UPnP: setsockopt "
+                                  "IP_ADD_MEMBERSHIP errno %d (%s)",
+                                  errno, strerror(errno));
+                       return -1;
+               }
+       }
+#endif  /* not needed */
+
+       /*
+        * TODO: What about IP_MULTICAST_LOOP? It seems to be on by default?
+        * which aids debugging I suppose but isn't really necessary?
+        */
+
+       return sd;
+}
+
+
+/**
+ * ssdp_open_multicast - Open socket for sending multicast SSDP messages
+ * @sm: WPS UPnP state machine from upnp_wps_device_init()
+ * Returns: 0 on success, -1 on failure
+ */
+int ssdp_open_multicast(struct upnp_wps_device_sm *sm)
+{
+       sm->multicast_sd = ssdp_open_multicast_sock(sm->ip_addr);
+       if (sm->multicast_sd < 0)
+               return -1;
+       return 0;
+}