/* * 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 * * See wps_upnp.c for more details on licensing and code history. */ #include "includes.h" #include #include #include #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 advertisement_state_machine *a, int *islast) { struct wpabuf *msg; char *NTString = ""; char uuid_string[80]; *islast = 0; uuid_bin2str(a->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", a->sm->ip_addr_text, a->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() */ void advertisement_state_machine_stop(struct upnp_wps_device_sm *sm) { eloop_cancel_timeout(advertisement_state_machine_handler, NULL, sm); } 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(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); /* * Start out advertising down, this automatically switches * to advertising up which signals our restart. */ a->type = ADVERTISE_DOWN; a->state = 0; a->sm = sm; /* (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. **************************************************************************/ static void msearchreply_state_machine_handler(void *eloop_data, void *user_ctx); /** * 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) { struct upnp_wps_device_sm *sm = a->sm; wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH stop"); if (a->next == a) { sm->msearch_replies = NULL; } else { if (sm->msearch_replies == a) sm->msearch_replies = a->next; a->next->prev = a->prev; a->prev->next = a->next; } os_free(a); sm->n_msearch_replies--; } 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 = a->sm; 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(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; wpa_printf(MSG_DEBUG, "WPS UPnP: M-SEARCH reply start (%d " "outstanding)", sm->n_msearch_replies); if (sm->n_msearch_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; a->sm = sm; 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 */ if (sm->msearch_replies) { a->next = sm->msearch_replies; a->prev = a->next->prev; a->prev->next = a; a->next->prev = a; } else { sm->msearch_replies = a->next = a->prev = a; } sm->n_msearch_replies++; 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: * MAN:"ssdp:discover" * MX: * * 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) { const char *start = data; 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))) return -1; if (setsockopt(sd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl))) 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; }