/* * Copyright (C) 2015-2019 Espen Jürgensen * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_ENDIAN_H # include #elif defined(HAVE_SYS_ENDIAN_H) # include #elif defined(HAVE_LIBKERN_OSBYTEORDER_H) #include #define htobe32(x) OSSwapHostToBigInt32(x) #define be32toh(x) OSSwapBigToHostInt32(x) #endif #include #include #include #include "conffile.h" #include "mdns.h" #include "transcode.h" #include "logger.h" #include "player.h" #include "rtp_common.h" #include "outputs.h" #ifdef HAVE_PROTOBUF_OLD #include "cast_channel.v0.pb-c.h" #else #include "cast_channel.pb-c.h" #endif // Number of bytes to request from TLS connection #define MAX_BUF 4096 // CA file location (not very portable...?) #define CAFILE "/etc/ssl/certs/ca-certificates.crt" // Seconds without a heartbeat from the Chromecast before we close the session //#define HEARTBEAT_TIMEOUT 30 // Seconds to wait for a reply before making the callback requested by caller #define REPLY_TIMEOUT 5 // ID of the audio mirroring app used by Chrome (Google Home) #define CAST_APP_ID "85CDB22F" // Old mirroring app (Chromecast) #define CAST_APP_ID_OLD "0F5096E8" // Namespaces #define NS_CONNECTION "urn:x-cast:com.google.cast.tp.connection" #define NS_RECEIVER "urn:x-cast:com.google.cast.receiver" #define NS_HEARTBEAT "urn:x-cast:com.google.cast.tp.heartbeat" #define NS_MEDIA "urn:x-cast:com.google.cast.media" #define NS_WEBRTC "urn:x-cast:com.google.cast.webrtc" #define USE_TRANSPORT_ID (1 << 1) #define USE_REQUEST_ID (1 << 2) #define USE_REQUEST_ID_ONLY (1 << 3) #define CALLBACK_REGISTER_SIZE 32 // Chromium will send OPUS encoded 10 ms packets (48kHz), about 120 bytes. We // use a 20 ms packet, so 50 pkts/sec, because that's the default for ffmpeg. // A 20 ms audio packet at 48000 kHz makes this number 48000 * (20 / 1000) #define CAST_SAMPLES_PER_PACKET 960 #define CAST_QUALITY_SAMPLE_RATE_DEFAULT 48000 #define CAST_QUALITY_BITS_PER_SAMPLE_DEFAULT 16 #define CAST_QUALITY_CHANNELS_DEFAULT 2 /* Notes * OFFER/ANSWER <-webrtc * RTCP/RTP * XR custom receiver report * Control and data on same UDP connection * OPUS encoded */ //#define DEBUG_CONNECTION 1 union sockaddr_all { struct sockaddr_in sin; struct sockaddr_in6 sin6; struct sockaddr sa; struct sockaddr_storage ss; }; struct cast_session; struct cast_msg_payload; // See cast_packet_header_make() #define CAST_HEADER_SIZE 11 #define CAST_PACKET_BUFFER_SIZE 1000 static struct encode_ctx *cast_encode_ctx; static struct evbuffer *cast_encoded_data; typedef void (*cast_reply_cb)(struct cast_session *cs, struct cast_msg_payload *payload); // Session is starting up #define CAST_STATE_F_STARTUP (1 << 13) // The default receiver app is ready #define CAST_STATE_F_MEDIA_CONNECTED (1 << 14) // Media is loaded in the receiver app #define CAST_STATE_F_MEDIA_LOADED (1 << 15) // Media is playing in the receiver app #define CAST_STATE_F_MEDIA_STREAMING (1 << 16) // Beware, the order of this enum has meaning enum cast_state { // Something bad happened during a session CAST_STATE_FAILED = 0, // No session allocated CAST_STATE_NONE = 1, // Session allocated, but no connection CAST_STATE_DISCONNECTED = CAST_STATE_F_STARTUP | 0x01, // TCP connect, TLS handshake, CONNECT and GET_STATUS request CAST_STATE_CONNECTED = CAST_STATE_F_STARTUP | 0x02, // Receiver app has been launched CAST_STATE_MEDIA_LAUNCHED = CAST_STATE_F_STARTUP | 0x03, // CONNECT, GET_STATUS and OFFER made to receiver app CAST_STATE_MEDIA_CONNECTED = CAST_STATE_F_MEDIA_CONNECTED, // After OFFER CAST_STATE_MEDIA_STREAMING = CAST_STATE_F_MEDIA_CONNECTED | CAST_STATE_F_MEDIA_STREAMING, /* // Receiver app has loaded our media CAST_STATE_MEDIA_LOADED = CAST_STATE_F_MEDIA_CONNECTED | CAST_STATE_F_MEDIA_LOADED, // After PAUSE CAST_STATE_MEDIA_PAUSED = CAST_STATE_F_MEDIA_CONNECTED | CAST_STATE_F_MEDIA_LOADED | 0x01, // After LOAD CAST_STATE_MEDIA_BUFFERING = CAST_STATE_F_MEDIA_CONNECTED | CAST_STATE_F_MEDIA_LOADED | CAST_STATE_F_MEDIA_STREAMING, // After PLAY CAST_STATE_MEDIA_PLAYING = CAST_STATE_F_MEDIA_CONNECTED | CAST_STATE_F_MEDIA_LOADED | CAST_STATE_F_MEDIA_STREAMING | 0x01, */ }; struct cast_master_session { struct evbuffer *evbuf; int evbuf_samples; struct rtp_session *rtp_session; struct media_quality quality; uint8_t *rawbuf; size_t rawbuf_size; int samples_per_packet; // Number of samples that we tell the output to buffer (this will mean that // the position that we send in the sync packages are offset by this amount // compared to the rtptimes of the corresponding RTP packages we are sending) int output_buffer_samples; }; struct cast_session { uint64_t device_id; int callback_id; struct cast_master_session *master_session; // Current state enum cast_state state; // Used to register a target state if we are transitioning from one to another enum cast_state wanted_state; // Connection fd and session, and listener event int64_t server_fd; // Use int64 so we can cast in gnutls_transport_set_ptr() gnutls_session_t tls_session; struct event *ev; char *devname; char *address; int family; unsigned short port; // ChromeCast uses a float between 0 - 1 float volume; uint32_t ssrc_id; // IP address URL of forked-daapd's mp3 stream char stream_url[128]; // Outgoing request which have the USE_REQUEST_ID flag get a new id, and a // callback is registered. The callback is called when an incoming message // from the peer with that request id arrives. If nothing arrives within // REPLY_TIMEOUT we make the callback with a NULL payload pointer. int request_id; cast_reply_cb callback_register[CALLBACK_REGISTER_SIZE]; struct event *reply_timeout; // This is used to work around a bug where no response is given by the device. // For certain requests, we will then retry, e.g. by checking status. We // register our retry so that we on only retry once. int retry; // Session info from the Chromecast char *transport_id; char *session_id; int media_session_id; int udp_fd; unsigned short udp_port; struct cast_session *next; }; enum cast_msg_types { UNKNOWN, PING, PONG, CONNECT, CLOSE, GET_STATUS, RECEIVER_STATUS, LAUNCH, LAUNCH_OLD, LAUNCH_ERROR, STOP, MEDIA_CONNECT, MEDIA_CLOSE, OFFER, ANSWER, MEDIA_GET_STATUS, MEDIA_STATUS, MEDIA_LOAD, MEDIA_PLAY, MEDIA_PAUSE, MEDIA_STOP, MEDIA_LOAD_FAILED, MEDIA_LOAD_CANCELLED, SET_VOLUME, PRESENTATION, }; struct cast_msg_basic { enum cast_msg_types type; char *tag; // Used for looking up incoming message type char *namespace; char *payload; int flags; }; struct cast_msg_payload { enum cast_msg_types type; int request_id; const char *app_id; const char *session_id; const char *transport_id; const char *player_state; const char *result; int media_session_id; unsigned short udp_port; }; // Array of the cast messages that we use. Must be in sync with cast_msg_types. struct cast_msg_basic cast_msg[] = { { .type = UNKNOWN, .namespace = "", .payload = "", }, { .type = PING, .tag = "PING", .namespace = NS_HEARTBEAT, .payload = "{'type':'PING'}", }, { .type = PONG, .tag = "PONG", .namespace = NS_HEARTBEAT, .payload = "{'type':'PONG'}", }, { .type = CONNECT, .namespace = NS_CONNECTION, .payload = "{'type':'CONNECT'}", // msg.payload_utf8 = "{\"origin\":{},\"userAgent\":\"forked-daapd\",\"type\":\"CONNECT\",\"senderInfo\":{\"browserVersion\":\"44.0.2403.30\",\"version\":\"15.605.1.3\",\"connectionType\":1,\"platform\":4,\"sdkType\":2,\"systemVersion\":\"Macintosh; Intel Mac OS X10_10_3\"}}"; }, { .type = CLOSE, .tag = "CLOSE", .namespace = NS_CONNECTION, .payload = "{'type':'CLOSE'}", }, { .type = GET_STATUS, .namespace = NS_RECEIVER, .payload = "{'type':'GET_STATUS','requestId':%d}", .flags = USE_REQUEST_ID_ONLY, }, { .type = RECEIVER_STATUS, .tag = "RECEIVER_STATUS", }, { .type = LAUNCH, .namespace = NS_RECEIVER, .payload = "{'type':'LAUNCH','requestId':%d,'appId':'" CAST_APP_ID "'}", .flags = USE_REQUEST_ID_ONLY, }, { .type = LAUNCH_OLD, .namespace = NS_RECEIVER, .payload = "{'type':'LAUNCH','requestId':%d,'appId':'" CAST_APP_ID_OLD "'}", .flags = USE_REQUEST_ID_ONLY, }, { .type = LAUNCH_ERROR, .tag = "LAUNCH_ERROR", }, { .type = STOP, .namespace = NS_RECEIVER, .payload = "{'type':'STOP','sessionId':'%s','requestId':%d}", .flags = USE_REQUEST_ID, }, { .type = MEDIA_CONNECT, .namespace = NS_CONNECTION, .payload = "{'type':'CONNECT'}", .flags = USE_TRANSPORT_ID, }, { .type = MEDIA_CLOSE, .namespace = NS_CONNECTION, .payload = "{'type':'CLOSE'}", .flags = USE_TRANSPORT_ID, }, { .type = OFFER, .namespace = NS_WEBRTC, // codecName can be aac or opus, ssrc should be random // We don't set 'aesKey' and 'aesIvMask' // sampleRate seems to be ignored // storeTime unknown meaning - perhaps size of buffer? // targetDelay - should be RTP delay in ms, but doesn't seem to change anything? .payload = "{'type':'OFFER','seqNum':%d,'offer':{'castMode':'mirroring','supportedStreams':[{'index':0,'type':'audio_source','codecName':'opus','rtpProfile':'cast','rtpPayloadType':127,'ssrc':%d,'storeTime':400,'targetDelay':400,'bitRate':128000,'sampleRate':48000,'timeBase':'1/48000','channels':2,'receiverRtcpEventLog':false}]}}", .flags = USE_TRANSPORT_ID | USE_REQUEST_ID, }, { .type = ANSWER, .tag = "ANSWER", }, { .type = MEDIA_GET_STATUS, .namespace = NS_MEDIA, .payload = "{'type':'GET_STATUS','requestId':%d}", .flags = USE_TRANSPORT_ID | USE_REQUEST_ID_ONLY, }, { .type = MEDIA_STATUS, .tag = "MEDIA_STATUS", }, { .type = MEDIA_LOAD, .namespace = NS_MEDIA, .payload = "{'currentTime':0,'media':{'contentId':'%s','streamType':'LIVE','contentType':'audio/mp3'},'customData':{},'sessionId':'%s','requestId':%d,'type':'LOAD','autoplay':1}", .flags = USE_TRANSPORT_ID | USE_REQUEST_ID, }, { .type = MEDIA_PLAY, .namespace = NS_MEDIA, .payload = "{'mediaSessionId':%d,'sessionId':'%s','type':'PLAY','requestId':%d}", .flags = USE_TRANSPORT_ID | USE_REQUEST_ID, }, { .type = MEDIA_PAUSE, .namespace = NS_MEDIA, .payload = "{'mediaSessionId':%d,'sessionId':'%s','type':'PAUSE','requestId':%d}", .flags = USE_TRANSPORT_ID | USE_REQUEST_ID, }, { .type = MEDIA_STOP, .namespace = NS_MEDIA, .payload = "{'mediaSessionId':%d,'sessionId':'%s','type':'STOP','requestId':%d}", .flags = USE_TRANSPORT_ID | USE_REQUEST_ID, }, { .type = MEDIA_LOAD_FAILED, .tag = "LOAD_FAILED", }, { .type = MEDIA_LOAD_CANCELLED, .tag = "LOAD_CANCELLED", }, { .type = SET_VOLUME, .namespace = NS_RECEIVER, .payload = "{'type':'SET_VOLUME','volume':{'level':%.2f,'muted':0},'requestId':%d}", .flags = USE_REQUEST_ID, }, { .type = PRESENTATION, .namespace = NS_WEBRTC, .payload = "{'type':'PRESENTATION','sessionId':'%s',seqnum:%d,'title':'forked-daapd','icons':[{'url':'http://www.gyfgafguf.dk/images/fugl.jpg'}] }", .flags = USE_TRANSPORT_ID | USE_REQUEST_ID, }, { .type = 0, }, }; /* From player.c */ extern struct event_base *evbase_player; /* Globals */ static gnutls_certificate_credentials_t tls_credentials; static struct cast_session *cast_sessions; static struct cast_master_session *cast_master_session; //static struct timeval heartbeat_timeout = { HEARTBEAT_TIMEOUT, 0 }; static struct timeval reply_timeout = { REPLY_TIMEOUT, 0 }; static struct media_quality cast_quality_default = { CAST_QUALITY_SAMPLE_RATE_DEFAULT, CAST_QUALITY_BITS_PER_SAMPLE_DEFAULT, CAST_QUALITY_CHANNELS_DEFAULT }; /* ------------------------------- MISC HELPERS ----------------------------- */ static int cast_connect(const char *address, unsigned short port, int family, int type) { union sockaddr_all sa; int fd; int len; int ret; DPRINTF(E_DBG, L_CAST, "Connecting to %s (family=%d), port %u\n", address, family, port); // TODO Open non-block right away so we don't block the player while connecting // and during TLS handshake (we would probably need to introduce a deferredev) #ifdef SOCK_CLOEXEC fd = socket(family, type | SOCK_CLOEXEC, 0); #else fd = socket(family, type, 0); #endif if (fd < 0) { DPRINTF(E_LOG, L_CAST, "Could not create socket: %s\n", strerror(errno)); return -1; } switch (family) { case AF_INET: sa.sin.sin_port = htons(port); ret = inet_pton(AF_INET, address, &sa.sin.sin_addr); len = sizeof(sa.sin); break; case AF_INET6: sa.sin6.sin6_port = htons(port); ret = inet_pton(AF_INET6, address, &sa.sin6.sin6_addr); len = sizeof(sa.sin6); break; default: DPRINTF(E_WARN, L_CAST, "Unknown family %d\n", family); close(fd); return -1; } if (ret <= 0) { DPRINTF(E_LOG, L_CAST, "Device address not valid (%s)\n", address); close(fd); return -1; } sa.ss.ss_family = family; ret = connect(fd, &sa.sa, len); if (ret < 0) { DPRINTF(E_LOG, L_CAST, "connect() to [%s]:%u failed: %s\n", address, port, strerror(errno)); close(fd); return -1; } return fd; } static void cast_disconnect(int fd) { /* no more receptions */ shutdown(fd, SHUT_RDWR); close(fd); } static int stream_url_make(char *out, size_t len, const char *peer_addr, int family) { struct ifaddrs *ifap; struct ifaddrs *ifa; union sockaddr_all haddr; union sockaddr_all hmask; union sockaddr_all paddr; char host_addr[128]; unsigned short port; int found; int ret; if (family == AF_INET) ret = inet_pton(AF_INET, peer_addr, &paddr.sin.sin_addr); else ret = inet_pton(AF_INET6, peer_addr, &paddr.sin6.sin6_addr); if (ret != 1) return -1; found = 0; ret = getifaddrs(&ifap); if (ret < 0) { DPRINTF(E_LOG, L_CAST, "Could not get interface address: %s\n", strerror(errno)); return -1; } for (ifa = ifap; !found && ifa; ifa = ifa->ifa_next) { if (!ifa->ifa_addr) { DPRINTF(E_LOG, L_CAST, "Skipping null address from getifaddrs()\n"); continue; } if (ifa->ifa_addr->sa_family != family) continue; if (family == AF_INET) { memcpy(&haddr.sin, ifa->ifa_addr, sizeof(struct sockaddr_in)); memcpy(&hmask.sin, ifa->ifa_netmask, sizeof(struct sockaddr_in)); found = ((haddr.sin.sin_addr.s_addr & hmask.sin.sin_addr.s_addr) == (paddr.sin.sin_addr.s_addr & hmask.sin.sin_addr.s_addr)); if (found) inet_ntop(family, &haddr.sin.sin_addr, host_addr, sizeof(host_addr)); } else if (family == AF_INET6) { memcpy(&haddr.sin6, ifa->ifa_addr, sizeof(struct sockaddr_in6)); found = (memcmp(&haddr.sin6.sin6_addr.s6_addr, &paddr.sin6.sin6_addr.s6_addr, 8) == 0); if (found) inet_ntop(family, &haddr.sin6.sin6_addr, host_addr, sizeof(host_addr)); } } freeifaddrs(ifap); if (!found) return -1; port = cfg_getint(cfg_getsec(cfg, "library"), "port"); if (family == AF_INET) snprintf(out, len, "http://%s:%d/stream.mp3", host_addr, port); else snprintf(out, len, "http://[%s]:%d/stream.mp3", host_addr, port); return 0; } static char * squote_to_dquote(char *buf) { char *ptr; for (ptr = buf; *ptr != '\0'; ptr++) if (*ptr == '\'') *ptr = '"'; return buf; } /* ----------------------------- SESSION CLEANUP ---------------------------- */ static void master_session_free(struct cast_master_session *cms) { if (!cms) return; outputs_quality_unsubscribe(&cms->rtp_session->quality); rtp_session_free(cms->rtp_session); evbuffer_free(cms->evbuf); free(cms->rawbuf); free(cms); } static void master_session_cleanup(struct cast_master_session *cms) { struct cast_session *cs; // First check if any other session is using the master session for (cs = cast_sessions; cs; cs=cs->next) { if (cs->master_session == cms) return; } if (cms == cast_master_session) cast_master_session = NULL; master_session_free(cms); } static void cast_session_free(struct cast_session *cs) { if (!cs) return; master_session_cleanup(cs->master_session); event_free(cs->reply_timeout); event_free(cs->ev); if (cs->server_fd >= 0) cast_disconnect(cs->server_fd); if (cs->udp_fd >= 0) cast_disconnect(cs->udp_fd); gnutls_deinit(cs->tls_session); if (cs->address) free(cs->address); if (cs->devname) free(cs->devname); if (cs->session_id) free(cs->session_id); if (cs->transport_id) free(cs->transport_id); free(cs); } static void cast_session_cleanup(struct cast_session *cs) { struct cast_session *s; if (cs == cast_sessions) cast_sessions = cast_sessions->next; else { for (s = cast_sessions; s && (s->next != cs); s = s->next) ; /* EMPTY */ if (!s) DPRINTF(E_WARN, L_CAST, "WARNING: struct cast_session not found in list; BUG!\n"); else s->next = cs->next; } outputs_device_session_remove(cs->device_id); cast_session_free(cs); } // Forward static void cast_session_shutdown(struct cast_session *cs, enum cast_state wanted_state); /* --------------------------- CAST MESSAGE HANDLING ------------------------ */ static int cast_msg_send(struct cast_session *cs, enum cast_msg_types type, cast_reply_cb reply_cb) { Extensions__CoreApi__CastChannel__CastMessage msg = EXTENSIONS__CORE_API__CAST_CHANNEL__CAST_MESSAGE__INIT; char msg_buf[MAX_BUF]; uint8_t buf[MAX_BUF]; uint32_t be; size_t len; int ret; #ifdef DEBUG_CONNECTION DPRINTF(E_DBG, L_CAST, "Preparing to send message type %d to '%s'\n", type, cs->devname); #endif msg.source_id = "sender-0"; msg.namespace_ = cast_msg[type].namespace; if ((cast_msg[type].flags & USE_TRANSPORT_ID) && !cs->transport_id) { DPRINTF(E_LOG, L_CAST, "Error, didn't get transportId for message (type %d) to '%s'\n", type, cs->devname); return -1; } if (cast_msg[type].flags & USE_TRANSPORT_ID) msg.destination_id = cs->transport_id; else msg.destination_id = "receiver-0"; if (cast_msg[type].flags & (USE_REQUEST_ID | USE_REQUEST_ID_ONLY)) { cs->request_id++; if (reply_cb) { cs->callback_register[cs->request_id % CALLBACK_REGISTER_SIZE] = reply_cb; event_add(cs->reply_timeout, &reply_timeout); } } // Special handling of some message types if (cast_msg[type].flags & USE_REQUEST_ID_ONLY) snprintf(msg_buf, sizeof(msg_buf), cast_msg[type].payload, cs->request_id); else if (type == STOP) snprintf(msg_buf, sizeof(msg_buf), cast_msg[type].payload, cs->session_id, cs->request_id); else if (type == OFFER) snprintf(msg_buf, sizeof(msg_buf), cast_msg[type].payload, cs->request_id, cs->ssrc_id); else if (type == PRESENTATION) snprintf(msg_buf, sizeof(msg_buf), cast_msg[type].payload, cs->session_id, cs->request_id); else if (type == MEDIA_LOAD) snprintf(msg_buf, sizeof(msg_buf), cast_msg[type].payload, cs->stream_url, cs->session_id, cs->request_id); else if ((type == MEDIA_PLAY) || (type == MEDIA_PAUSE) || (type == MEDIA_STOP)) snprintf(msg_buf, sizeof(msg_buf), cast_msg[type].payload, cs->media_session_id, cs->session_id, cs->request_id); else if (type == SET_VOLUME) snprintf(msg_buf, sizeof(msg_buf), cast_msg[type].payload, cs->volume, cs->request_id); else snprintf(msg_buf, sizeof(msg_buf), "%s", cast_msg[type].payload); squote_to_dquote(msg_buf); msg.payload_utf8 = msg_buf; len = extensions__core_api__cast_channel__cast_message__get_packed_size(&msg); if (len <= 0) { DPRINTF(E_LOG, L_CAST, "Could not send message (type %d), invalid length: %zu\n", type, len); return -1; } // The message must be prefixed with Big-Endian 32 bit length be = htobe32(len); memcpy(buf, &be, 4); // Now add the packed message and send it extensions__core_api__cast_channel__cast_message__pack(&msg, buf + 4); ret = gnutls_record_send(cs->tls_session, buf, len + 4); if (ret < 0) { DPRINTF(E_LOG, L_CAST, "Could not send message, TLS error\n"); return -1; } else if (ret != len + 4) { DPRINTF(E_LOG, L_CAST, "BUG! Message partially sent, and we are not able to send the rest\n"); return -1; } if (type != PONG) DPRINTF(E_DBG, L_CAST, "TX %zu %s %s %s %s\n", len, msg.source_id, msg.destination_id, msg.namespace_, msg.payload_utf8); return 0; } static void * cast_msg_parse(struct cast_msg_payload *payload, char *s) { json_object *haystack; json_object *somehay; json_object *needle; const char *val; int i; haystack = json_tokener_parse(s); if (!haystack) { DPRINTF(E_LOG, L_CAST, "JSON parser returned an error\n"); return NULL; } payload->type = UNKNOWN; if (json_object_object_get_ex(haystack, "type", &needle)) { val = json_object_get_string(needle); for (i = 1; cast_msg[i].type; i++) { if (cast_msg[i].tag && (strcmp(val, cast_msg[i].tag) == 0)) { payload->type = cast_msg[i].type; break; } } } if (json_object_object_get_ex(haystack, "requestId", &needle)) payload->request_id = json_object_get_int(needle); else if (json_object_object_get_ex(haystack, "seqNum", &needle)) payload->request_id = json_object_get_int(needle); if (json_object_object_get_ex(haystack, "answer", &somehay) && json_object_object_get_ex(somehay, "udpPort", &needle) && json_object_get_type(needle) == json_type_int ) payload->udp_port = json_object_get_int(needle); if (json_object_object_get_ex(haystack, "result", &needle) && json_object_get_type(needle) == json_type_string ) payload->result = json_object_get_string(needle); // Might be done now if ((payload->type != RECEIVER_STATUS) && (payload->type != MEDIA_STATUS)) return haystack; // Isn't this marvelous if ( json_object_object_get_ex(haystack, "status", &needle) && (json_object_get_type(needle) == json_type_array) && (somehay = json_object_array_get_idx(needle, 0)) ) { if ( json_object_object_get_ex(somehay, "mediaSessionId", &needle) && (json_object_get_type(needle) == json_type_int) ) payload->media_session_id = json_object_get_int(needle); if ( json_object_object_get_ex(somehay, "playerState", &needle) && (json_object_get_type(needle) == json_type_string) ) payload->player_state = json_object_get_string(needle); } if ( json_object_object_get_ex(haystack, "status", &somehay) && json_object_object_get_ex(somehay, "applications", &needle) && (json_object_get_type(needle) == json_type_array) && (somehay = json_object_array_get_idx(needle, 0)) ) { if ( json_object_object_get_ex(somehay, "appId", &needle) && (json_object_get_type(needle) == json_type_string) ) payload->app_id = json_object_get_string(needle); if ( json_object_object_get_ex(somehay, "sessionId", &needle) && (json_object_get_type(needle) == json_type_string) ) payload->session_id = json_object_get_string(needle); if ( json_object_object_get_ex(somehay, "transportId", &needle) && (json_object_get_type(needle) == json_type_string) ) payload->transport_id = json_object_get_string(needle); } return haystack; } static void cast_msg_parse_free(void *haystack) { #ifdef HAVE_JSON_C_OLD json_object_put((json_object *)haystack); #else if (json_object_put((json_object *)haystack) != 1) DPRINTF(E_LOG, L_CAST, "Memleak: JSON parser did not free object\n"); #endif } static void cast_msg_process(struct cast_session *cs, const uint8_t *data, size_t len) { Extensions__CoreApi__CastChannel__CastMessage *reply; cast_reply_cb reply_cb; struct cast_msg_payload payload = { 0 }; void *hdl; int unknown_app_id; int unknown_session_id; int i; #ifdef DEBUG_CONNECTION char *b64 = b64_encode(data, len); if (b64) { DPRINTF(E_DBG, L_CAST, "Reply dump (len %zu): %s\n", len, b64); free(b64); } #endif reply = extensions__core_api__cast_channel__cast_message__unpack(NULL, len, data); if (!reply) { DPRINTF(E_LOG, L_CAST, "Could not unpack message!\n"); return; } hdl = cast_msg_parse(&payload, reply->payload_utf8); if (!hdl) { DPRINTF(E_DBG, L_CAST, "Could not parse message: %s\n", reply->payload_utf8); goto out_free_unpacked; } if (payload.type == PING) { cast_msg_send(cs, PONG, NULL); goto out_free_parsed; } DPRINTF(E_DBG, L_CAST, "RX %zu %s %s %s %s\n", len, reply->source_id, reply->destination_id, reply->namespace_, reply->payload_utf8); if (payload.type == UNKNOWN) goto out_free_parsed; i = payload.request_id % CALLBACK_REGISTER_SIZE; if (payload.request_id && cs->callback_register[i]) { reply_cb = cs->callback_register[i]; cs->callback_register[i] = NULL; // Cancel the timeout if no pending callbacks for (i = 0; (i < CALLBACK_REGISTER_SIZE) && (!cs->callback_register[i]); i++); if (i == CALLBACK_REGISTER_SIZE) evtimer_del(cs->reply_timeout); reply_cb(cs, &payload); goto out_free_parsed; } // TODO Should we read volume and playerstate changes from the Chromecast? if (payload.type == RECEIVER_STATUS && (cs->state & CAST_STATE_F_MEDIA_CONNECTED)) { unknown_app_id = payload.app_id && (strcmp(payload.app_id, CAST_APP_ID) != 0); unknown_session_id = payload.session_id && (strcmp(payload.session_id, cs->session_id) != 0); if (unknown_app_id || unknown_session_id) { DPRINTF(E_WARN, L_CAST, "Our session on '%s' was hijacked\n", cs->devname); // Downgrade state, we don't have the receiver app any more cs->state = CAST_STATE_CONNECTED; cast_session_shutdown(cs, CAST_STATE_FAILED); goto out_free_parsed; } } if (payload.type == CLOSE && (cs->state & CAST_STATE_F_MEDIA_CONNECTED)) { // Downgrade state, we can't write any more cs->state = CAST_STATE_CONNECTED; cast_session_shutdown(cs, CAST_STATE_FAILED); goto out_free_parsed; } if (payload.type == MEDIA_STATUS && (cs->state & CAST_STATE_F_MEDIA_STREAMING)) { if (payload.player_state && (strcmp(payload.player_state, "PAUSED") == 0)) { DPRINTF(E_WARN, L_CAST, "Something paused our session on '%s'\n", cs->devname); /* cs->state = CAST_STATE_MEDIA_CONNECTED; // Kill the session, the player will need to restart it cast_session_shutdown(cs, CAST_STATE_NONE); goto out_free_parsed; */ } } out_free_parsed: cast_msg_parse_free(hdl); out_free_unpacked: extensions__core_api__cast_channel__cast_message__free_unpacked(reply, NULL); } /* -------------------------------- CALLBACKS ------------------------------- */ /* Maps our internal state to the generic output state and then makes a callback * to the player to tell that state */ static void cast_status(struct cast_session *cs) { enum output_device_state state; switch (cs->state) { case CAST_STATE_FAILED: state = OUTPUT_STATE_FAILED; break; case CAST_STATE_NONE: state = OUTPUT_STATE_STOPPED; break; case CAST_STATE_DISCONNECTED ... CAST_STATE_MEDIA_LAUNCHED: state = OUTPUT_STATE_STARTUP; break; case CAST_STATE_MEDIA_CONNECTED: state = OUTPUT_STATE_CONNECTED; break; /* case CAST_STATE_MEDIA_LOADED ... CAST_STATE_MEDIA_PAUSED: state = OUTPUT_STATE_CONNECTED; break; case CAST_STATE_MEDIA_BUFFERING ... CAST_STATE_MEDIA_STREAMING: state = OUTPUT_STATE_STREAMING; break; */ case CAST_STATE_MEDIA_STREAMING: state = OUTPUT_STATE_STREAMING; break; default: DPRINTF(E_LOG, L_CAST, "Bug! Unhandled state in cast_status()\n"); state = OUTPUT_STATE_FAILED; } outputs_cb(cs->callback_id, cs->device_id, state); cs->callback_id = -1; } /* cast_cb_stop*: Callback chain for shutting down a session */ static void cast_cb_stop(struct cast_session *cs, struct cast_msg_payload *payload) { if (!payload) DPRINTF(E_LOG, L_CAST, "No RECEIVER_STATUS reply to our STOP - will continue anyway\n"); else if (payload->type != RECEIVER_STATUS) DPRINTF(E_LOG, L_CAST, "No RECEIVER_STATUS reply to our STOP (got type: %d) - will continue anyway\n", payload->type); cs->state = CAST_STATE_CONNECTED; if (cs->state == cs->wanted_state) cast_status(cs); else cast_session_shutdown(cs, cs->wanted_state); } static void cast_cb_stop_media(struct cast_session *cs, struct cast_msg_payload *payload) { if (!payload) DPRINTF(E_LOG, L_CAST, "No MEDIA_STATUS reply to our STOP - will continue anyway\n"); else if (payload->type != MEDIA_STATUS) DPRINTF(E_LOG, L_CAST, "No MEDIA_STATUS reply to our STOP (got type: %d) - will continue anyway\n", payload->type); cs->state = CAST_STATE_MEDIA_CONNECTED; if (cs->state == cs->wanted_state) cast_status(cs); else cast_session_shutdown(cs, cs->wanted_state); } /* cast_cb_startup*: Callback chain for starting a session */ static void cast_cb_startup_volume(struct cast_session *cs, struct cast_msg_payload *payload) { /* Session startup and setup is done, tell our user */ DPRINTF(E_DBG, L_CAST, "Session ready\n"); cast_status(cs); } static void cast_cb_startup_offer(struct cast_session *cs, struct cast_msg_payload *payload) { int ret; if (!payload) { DPRINTF(E_LOG, L_CAST, "No reply from '%s' to our OFFER request\n", cs->devname); goto error; } else if (payload->type != ANSWER) { DPRINTF(E_LOG, L_CAST, "The device '%s' did not give us an ANSWER to our OFFER\n", cs->devname); goto error; } else if (!payload->udp_port || strcmp(payload->result, "ok") != 0) { DPRINTF(E_LOG, L_CAST, "Missing UDP port (or unexpected result '%s') in ANSWER - aborting\n", payload->result); goto error; } DPRINTF(E_INFO, L_CAST, "UDP port in ANSWER is %d\n", payload->udp_port); cs->udp_port = payload->udp_port; cs->udp_fd = cast_connect(cs->address, cs->udp_port, cs->family, SOCK_DGRAM); if (cs->udp_fd < 0) goto error; ret = cast_msg_send(cs, SET_VOLUME, cast_cb_startup_volume); if (ret < 0) goto error; cs->state = CAST_STATE_MEDIA_CONNECTED; return; error: cast_session_shutdown(cs, CAST_STATE_FAILED); } static void cast_cb_startup_media(struct cast_session *cs, struct cast_msg_payload *payload) { int ret; if (!payload) { DPRINTF(E_LOG, L_CAST, "No MEDIA_STATUS reply to our GET_STATUS - aborting\n"); goto error; } else if (payload->type != MEDIA_STATUS) { DPRINTF(E_LOG, L_CAST, "No MEDIA_STATUS reply to our GET_STATUS (got type: %d) - aborting\n", payload->type); goto error; } ret = cast_msg_send(cs, OFFER, cast_cb_startup_offer); if (ret < 0) goto error; return; error: cast_session_shutdown(cs, CAST_STATE_FAILED); } static void cast_cb_startup_launch(struct cast_session *cs, struct cast_msg_payload *payload) { int ret; // Sometimes the response to a LAUNCH is just a broadcast RECEIVER_STATUS // without our requestId. That won't be registered by our response handler, // and we get an empty callback due to timeout. In this case we send a // GET_STATUS to see if we are good to go anyway. if (!payload && !cs->retry) { DPRINTF(E_LOG, L_CAST, "No RECEIVER_STATUS reply to our LAUNCH - trying GET_STATUS instead\n"); cs->retry++; ret = cast_msg_send(cs, GET_STATUS, cast_cb_startup_launch); if (ret != 0) goto error; return; } if (!payload) { DPRINTF(E_LOG, L_CAST, "No RECEIVER_STATUS reply to our LAUNCH - aborting\n"); goto error; } if (payload->type == LAUNCH_ERROR && !cs->retry) { DPRINTF(E_WARN, L_CAST, "Device '%s' does not support app id '%s', trying '%s' instead\n", cs->devname, CAST_APP_ID, CAST_APP_ID_OLD); cs->retry++; ret = cast_msg_send(cs, LAUNCH_OLD, cast_cb_startup_launch); if (ret < 0) goto error; return; } if (payload->type != RECEIVER_STATUS) { DPRINTF(E_LOG, L_CAST, "No RECEIVER_STATUS reply to our LAUNCH (got type: %d) - aborting\n", payload->type); goto error; } if (!payload->transport_id || !payload->session_id) { DPRINTF(E_LOG, L_CAST, "Missing session id or transport id in RECEIVER_STATUS - aborting\n"); goto error; } if (cs->session_id || cs->transport_id) DPRINTF(E_LOG, L_CAST, "Bug! Memleaking...\n"); cs->session_id = strdup(payload->session_id); cs->transport_id = strdup(payload->transport_id); cs->retry = 0; ret = cast_msg_send(cs, MEDIA_CONNECT, NULL); if (ret == 0) ret = cast_msg_send(cs, MEDIA_GET_STATUS, cast_cb_startup_media); if (ret < 0) goto error; cs->state = CAST_STATE_MEDIA_LAUNCHED; return; error: cast_session_shutdown(cs, CAST_STATE_FAILED); } static void cast_cb_startup_connect(struct cast_session *cs, struct cast_msg_payload *payload) { int ret; if (!payload) { DPRINTF(E_LOG, L_CAST, "No RECEIVER_STATUS reply to our GET_STATUS - aborting\n"); goto error; } else if (payload->type != RECEIVER_STATUS) { DPRINTF(E_LOG, L_CAST, "No RECEIVER_STATUS reply to our GET_STATUS (got type: %d) - aborting\n", payload->type); goto error; } ret = cast_msg_send(cs, LAUNCH, cast_cb_startup_launch); if (ret < 0) goto error; cs->state = CAST_STATE_CONNECTED; return; error: cast_session_shutdown(cs, CAST_STATE_FAILED); } /* cast_cb_probe: Callback from cast_device_probe */ static void cast_cb_probe(struct cast_session *cs, struct cast_msg_payload *payload) { if (!payload) { DPRINTF(E_LOG, L_CAST, "No RECEIVER_STATUS reply to our GET_STATUS - aborting\n"); goto error; } else if (payload->type != RECEIVER_STATUS) { DPRINTF(E_LOG, L_CAST, "No RECEIVER_STATUS reply to our GET_STATUS (got type: %d) - aborting\n", payload->type); goto error; } cs->state = CAST_STATE_CONNECTED; cast_status(cs); cast_session_shutdown(cs, CAST_STATE_NONE); return; error: cast_session_shutdown(cs, CAST_STATE_FAILED); } /* cast_cb_load: Callback from starting playback */ /*static void cast_cb_load(struct cast_session *cs, struct cast_msg_payload *payload) { if (!payload) { DPRINTF(E_LOG, L_CAST, "No reply from '%s' to our OFFER request\n", cs->devname); goto error; } else if ((payload->type != ANSWER)) { DPRINTF(E_LOG, L_CAST, "The device '%s' did not give us an ANSWER to our OFFER\n", cs->devname); goto error; } // TODO check result == "ok" else if (!payload->udp_port) { DPRINTF(E_LOG, L_CAST, "Missing UDP port in ANSWER - aborting\n"); goto error; } DPRINTF(E_LOG, L_CAST, "UDP port in ANSWER is %d\n", payload->udp_port); cs->udp_port = payload->udp_port; cs->udp_fd = cast_connect(cs->address, cs->udp_port, cs->family, SOCK_DGRAM); if (cs->udp_fd < 0) goto error; cs->state = CAST_STATE_MEDIA_LOADED; cast_status(cs); return; error: cast_session_shutdown(cs, CAST_STATE_FAILED); } */ static void cast_cb_volume(struct cast_session *cs, struct cast_msg_payload *payload) { cast_status(cs); } static void cast_cb_flush(struct cast_session *cs, struct cast_msg_payload *payload) { if (!payload) DPRINTF(E_LOG, L_CAST, "No reply to PAUSE request from '%s' - will continue\n", cs->devname); else if (payload->type != MEDIA_STATUS) DPRINTF(E_LOG, L_CAST, "Unexpected reply to PAUSE request from '%s' - will continue\n", cs->devname); cs->state = CAST_STATE_MEDIA_CONNECTED; cast_status(cs); } static void cast_cb_presentation(struct cast_session *cs, struct cast_msg_payload *payload) { if (!payload) DPRINTF(E_LOG, L_CAST, "No reply to PRESENTATION request from '%s' - will continue\n", cs->devname); else if (payload->type != MEDIA_STATUS) DPRINTF(E_LOG, L_CAST, "Unexpected reply to PRESENTATION request from '%s' - will continue\n", cs->devname); } /* The core of this module. Libevent makes a callback to this function whenever * there is new data to be read on the fd from the ChromeCast. If everything is * good then the data will be passed to cast_msg_process() that will then * parse and make callbacks, if relevant. */ static void cast_listen_cb(int fd, short what, void *arg) { struct cast_session *cs; uint8_t buffer[MAX_BUF + 1]; // Not sure about the +1, but is copied from gnutls examples uint32_t be; size_t len; int received; int ret; for (cs = cast_sessions; cs; cs = cs->next) { if (cs == (struct cast_session *)arg) break; } if (!cs) { DPRINTF(E_INFO, L_CAST, "Callback on dead session, ignoring\n"); return; } if (what == EV_TIMEOUT) { DPRINTF(E_LOG, L_CAST, "No heartbeat from '%s', shutting down\n", cs->devname); goto fail; } #ifdef DEBUG_CONNECTION DPRINTF(E_DBG, L_CAST, "New data from '%s'\n", cs->devname); #endif // We first read the 4 byte header and then the actual message. The header // will be the length of the message. ret = gnutls_record_recv(cs->tls_session, buffer, 4); if (ret != 4) goto no_read; memcpy(&be, buffer, 4); len = be32toh(be); if ((len == 0) || (len > MAX_BUF)) { DPRINTF(E_LOG, L_CAST, "Bad length of incoming message, aborting (len=%zu, size=%d)\n", len, MAX_BUF); goto fail; } received = 0; while (received < len) { ret = gnutls_record_recv(cs->tls_session, buffer + received, len - received); if (ret <= 0) goto no_read; received += ret; #ifdef DEBUG_CONNECTION DPRINTF(E_DBG, L_CAST, "Received %d bytes out of expected %zu bytes\n", received, len); #endif } ret = gnutls_record_check_pending(cs->tls_session); // Process the message - note that this may result in cs being invalidated cast_msg_process(cs, buffer, len); // In the event there was more data waiting for us we go again if (ret > 0) { DPRINTF(E_INFO, L_CAST, "More data pending from device (%d bytes)\n", ret); cast_listen_cb(fd, what, arg); } return; no_read: if ((ret != GNUTLS_E_INTERRUPTED) && (ret != GNUTLS_E_AGAIN)) { DPRINTF(E_LOG, L_CAST, "Session error: %s\n", gnutls_strerror(ret)); goto fail; } DPRINTF(E_DBG, L_CAST, "Return value from tls is %d (GNUTLS_E_AGAIN is %d)\n", ret, GNUTLS_E_AGAIN); return; fail: // Downgrade state to make cast_session_shutdown perform an exit which is // quick and won't require a reponse from the device cs->state = CAST_STATE_CONNECTED; cast_session_shutdown(cs, CAST_STATE_FAILED); } static void cast_reply_timeout_cb(int fd, short what, void *arg) { struct cast_session *cs; int i; cs = (struct cast_session *)arg; i = cs->request_id % CALLBACK_REGISTER_SIZE; DPRINTF(E_LOG, L_CAST, "Request %d timed out, will run empty callback\n", i); if (cs->callback_register[i]) { cs->callback_register[i](cs, NULL); cs->callback_register[i] = NULL; } } static void cast_device_cb(const char *name, const char *type, const char *domain, const char *hostname, int family, const char *address, int port, struct keyval *txt) { struct output_device *device; const char *friendly_name; uint32_t id; id = djb_hash(name, strlen(name)); if (!id) { DPRINTF(E_LOG, L_CAST, "Could not hash ChromeCast device name (%s)\n", name); return; } friendly_name = keyval_get(txt, "fn"); if (friendly_name) name = friendly_name; DPRINTF(E_DBG, L_CAST, "Event for Chromecast device '%s' (port %d, id %" PRIu32 ")\n", name, port, id); device = calloc(1, sizeof(struct output_device)); if (!device) { DPRINTF(E_LOG, L_CAST, "Out of memory for new Chromecast device\n"); return; } device->id = id; device->name = strdup(name); device->type = OUTPUT_TYPE_CAST; device->type_name = outputs_name(device->type); if (port < 0) { /* Device stopped advertising */ switch (family) { case AF_INET: device->v4_port = 1; break; case AF_INET6: device->v6_port = 1; break; } player_device_remove(device); return; } DPRINTF(E_INFO, L_CAST, "Adding Chromecast device '%s'\n", name); device->advertised = 1; switch (family) { case AF_INET: device->v4_address = strdup(address); device->v4_port = port; break; case AF_INET6: device->v6_address = strdup(address); device->v6_port = port; break; } player_device_add(device); } /* --------------------------------- METADATA ------------------------------- */ static void metadata_send(struct cast_session *cs) { cast_msg_send(cs, PRESENTATION, cast_cb_presentation); } /* --------------------- SESSION CONSTRUCTION AND SHUTDOWN ------------------ */ static struct cast_master_session * master_session_make(struct media_quality *quality) { struct cast_master_session *cms; int ret; // First check if we already have a master session, then just use that if (cast_master_session) return cast_master_session; // Let's create a master session ret = outputs_quality_subscribe(quality); if (ret < 0) { DPRINTF(E_LOG, L_CAST, "Could not subscribe to required audio quality (%d/%d/%d)\n", quality->sample_rate, quality->bits_per_sample, quality->channels); return NULL; } CHECK_NULL(L_CAST, cms = calloc(1, sizeof(struct cast_master_session))); cms->rtp_session = rtp_session_new(quality, CAST_PACKET_BUFFER_SIZE, 0); if (!cms->rtp_session) { outputs_quality_unsubscribe(quality); free(cms); return NULL; } cms->quality = *quality; cms->samples_per_packet = CAST_SAMPLES_PER_PACKET; cms->rawbuf_size = STOB(cms->samples_per_packet, quality->bits_per_sample, quality->channels); cms->output_buffer_samples = OUTPUTS_BUFFER_DURATION * quality->sample_rate; CHECK_NULL(L_CAST, cms->rawbuf = malloc(cms->rawbuf_size)); CHECK_NULL(L_CAST, cms->evbuf = evbuffer_new()); cast_master_session = cms; return cms; } static struct cast_session * cast_session_make(struct output_device *device, int family, int callback_id) { struct cast_session *cs; const char *proto; const char *err; char *address; unsigned short port; int flags; int ret; switch (family) { case AF_INET: /* We always have the v4 services, so no need to check */ if (!device->v4_address) return NULL; address = device->v4_address; port = device->v4_port; break; case AF_INET6: if (!device->v6_address) return NULL; address = device->v6_address; port = device->v6_port; break; default: return NULL; } CHECK_NULL(L_CAST, cs = calloc(1, sizeof(struct cast_session))); cs->state = CAST_STATE_DISCONNECTED; cs->device_id = device->id; cs->callback_id = callback_id; cs->master_session = master_session_make(&cast_quality_default); if (!cs->master_session) { DPRINTF(E_LOG, L_CAST, "Could not attach a master session for device '%s'\n", device->name); goto out_free_session; } cs->ssrc_id = cs->master_session->rtp_session->ssrc_id; /* Init TLS session, use default priorities and put the x509 credentials to the current session */ if ( ((ret = gnutls_init(&cs->tls_session, GNUTLS_CLIENT)) != GNUTLS_E_SUCCESS) || ((ret = gnutls_priority_set_direct(cs->tls_session, "PERFORMANCE", &err)) != GNUTLS_E_SUCCESS) || ((ret = gnutls_credentials_set(cs->tls_session, GNUTLS_CRD_CERTIFICATE, tls_credentials)) != GNUTLS_E_SUCCESS) ) { DPRINTF(E_LOG, L_CAST, "Could not initialize GNUTLS session: %s\n", gnutls_strerror(ret)); goto out_free_master_session; } cs->server_fd = cast_connect(address, port, family, SOCK_STREAM); if (cs->server_fd < 0) { DPRINTF(E_LOG, L_CAST, "Could not connect to %s\n", device->name); goto out_deinit_gnutls; } ret = stream_url_make(cs->stream_url, sizeof(cs->stream_url), address, family); if (ret < 0) { DPRINTF(E_LOG, L_CAST, "Bug! Could find a network interface on same subnet as %s\n", device->name); goto out_close_connection; } cs->ev = event_new(evbase_player, cs->server_fd, EV_READ | EV_PERSIST, cast_listen_cb, cs); if (!cs->ev) { DPRINTF(E_LOG, L_CAST, "Out of memory for listener event\n"); goto out_close_connection; } cs->reply_timeout = evtimer_new(evbase_player, cast_reply_timeout_cb, cs); if (!cs->reply_timeout) { DPRINTF(E_LOG, L_CAST, "Out of memory for reply_timeout\n"); goto out_close_connection; } gnutls_transport_set_ptr(cs->tls_session, (gnutls_transport_ptr_t)cs->server_fd); ret = gnutls_handshake(cs->tls_session); if (ret != GNUTLS_E_SUCCESS) { DPRINTF(E_LOG, L_CAST, "Could not attach TLS to TCP connection: %s\n", gnutls_strerror(ret)); goto out_free_ev; } flags = fcntl(cs->server_fd, F_GETFL, 0); fcntl(cs->server_fd, F_SETFL, flags | O_NONBLOCK); event_add(cs->ev, NULL); // &heartbeat_timeout cs->devname = strdup(device->name); cs->address = strdup(address); cs->family = family; cs->udp_fd = -1; cs->volume = 0.01 * device->volume; cs->next = cast_sessions; cast_sessions = cs; // cs is now the official device session outputs_device_session_add(device->id, cs); proto = gnutls_protocol_get_name(gnutls_protocol_get_version(cs->tls_session)); DPRINTF(E_INFO, L_CAST, "Connection to '%s' established using %s\n", cs->devname, proto); return cs; out_free_ev: event_free(cs->reply_timeout); event_free(cs->ev); out_close_connection: cast_disconnect(cs->server_fd); out_deinit_gnutls: gnutls_deinit(cs->tls_session); out_free_master_session: master_session_cleanup(cs->master_session); out_free_session: free(cs); return NULL; } // Attempts to "nicely" bring down a session to wanted_state, and then issues // the callback. If wanted_state is CAST_STATE_NONE/FAILED then the session is purged. static void cast_session_shutdown(struct cast_session *cs, enum cast_state wanted_state) { int pending; int ret; if (cs->state == wanted_state) { cast_status(cs); return; } else if (cs->state < wanted_state) { DPRINTF(E_LOG, L_CAST, "Bug! Shutdown request got wanted_state (%d) that is higher than current state (%d)\n", wanted_state, cs->state); return; } cs->wanted_state = wanted_state; pending = 0; switch (cs->state) { // case CAST_STATE_MEDIA_LOADED ... CAST_STATE_MEDIA_STREAMING: case CAST_STATE_MEDIA_STREAMING: ret = cast_msg_send(cs, MEDIA_STOP, cast_cb_stop_media); pending = 1; break; case CAST_STATE_MEDIA_CONNECTED: cast_disconnect(cs->udp_fd); cs->udp_fd = -1; ret = cast_msg_send(cs, MEDIA_CLOSE, NULL); cs->state = CAST_STATE_MEDIA_LAUNCHED; if ((ret < 0) || (wanted_state >= CAST_STATE_MEDIA_LAUNCHED)) break; /* FALLTHROUGH */ case CAST_STATE_MEDIA_LAUNCHED: ret = cast_msg_send(cs, STOP, cast_cb_stop); pending = 1; break; case CAST_STATE_CONNECTED: ret = cast_msg_send(cs, CLOSE, NULL); if (ret == 0) gnutls_bye(cs->tls_session, GNUTLS_SHUT_RDWR); cast_disconnect(cs->server_fd); cs->server_fd = -1; cs->state = CAST_STATE_DISCONNECTED; break; case CAST_STATE_DISCONNECTED: ret = 0; break; default: DPRINTF(E_LOG, L_CAST, "Bug! Shutdown doesn't know how to handle current state\n"); ret = -1; } // We couldn't talk to the device, tell the user and clean up if (ret < 0) { cs->state = CAST_STATE_FAILED; cast_status(cs); cast_session_cleanup(cs); return; } // If pending callbacks then we let them take care of the rest if (pending) return; // Asked to destroy the session if (wanted_state == CAST_STATE_NONE || wanted_state == CAST_STATE_FAILED) { cs->state = wanted_state; cast_status(cs); cast_session_cleanup(cs); return; } cast_status(cs); } /* ------------------ PREPARING AND SENDING CAST RTP PACKETS ---------------- */ // Makes a Cast RTP packet (source: Chromium's media/cast/net/rtp/rtp_packetizer.cc) // // A Cast RTP packet is made of: // RTP header (12 bytes) // Cast header (7 bytes) // Extension data (4 bytes) // Packet data // // The Cast header + extension (optional?) consists of: // 0 1 2 3 // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // |k|r| n_ext | frame_id | packet id | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // | max_packet_id | ref_frame_id | ext_type | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // | ext_size | new_playout_delay_ms | // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // // k: Is the frame a key frame? // r: Is there a reference frame id? // n_ext: Number of Cast extensions (Chromium uses 1: Adaptive Latency) // ext_type: 0x04 Adaptive Latency extension // ext_size: 0x02 -> 2 bytes // new_playout_delay_ms: ?? // OPUS encodes the rawbuf payload static int payload_encode(struct evbuffer *evbuf, uint8_t *rawbuf, size_t rawbuf_size, int nsamples, struct media_quality *quality) { transcode_frame *frame; int len; frame = transcode_frame_new(rawbuf, rawbuf_size, nsamples, quality->sample_rate, quality->bits_per_sample); if (!frame) { DPRINTF(E_LOG, L_CAST, "Could not convert raw PCM to frame (bufsize=%ld)\n", rawbuf_size); return -1; } len = transcode_encode(evbuf, cast_encode_ctx, frame, 0); transcode_frame_free(frame); if (len < 0) { DPRINTF(E_LOG, L_CAST, "Could not Opus encode frame\n"); return -1; } return len; } static int packet_prepare(struct rtp_packet *pkt, struct evbuffer *evbuf) { // Cast header memset(pkt->payload, 0, CAST_HEADER_SIZE); pkt->payload[0] = 0xc1; // k = 1, r = 1 and one extension pkt->payload[1] = (char)pkt->seqnum; // packet_id and max_packet_id don't seem to be used, so leave them at 0 pkt->payload[6] = (char)pkt->seqnum; pkt->payload[7] = 0x04; // kCastRtpExtensionAdaptiveLatency has id (1 << 2) pkt->payload[8] = 0x02; // Extension will use two bytes // leave extension values at 0, but Chromium sets them to: // (frame.new_playout_delay_ms >> 8) and frame.new_playout_delay_ms (normal byte values are 0x03 0x20) // Copy payload return evbuffer_remove(evbuf, pkt->payload + CAST_HEADER_SIZE, pkt->payload_len - CAST_HEADER_SIZE); } static int packet_send(struct cast_session *cs, struct rtp_packet *pkt) { int ret; ret = send(cs->udp_fd, pkt->data, pkt->data_len, 0); if (ret < 0) { DPRINTF(E_LOG, L_CAST, "Send error for '%s': %s\n", cs->devname, strerror(errno)); return -1; } else if (ret != pkt->data_len) { DPRINTF(E_WARN, L_CAST, "Partial send (%d) for '%s'\n", ret, cs->devname); return 0; } /* DPRINTF(E_DBG, L_PLAYER, "RTP PACKET seqnum %u, rtptime %u, payload 0x%x, pktbuf_s %zu\n", cs->master_session->rtp_session->seqnum, cs->master_session->rtp_session->pos, pkt->header[1], cs->master_session->rtp_session->pktbuf_len ); */ return 0; } static int packets_send(struct cast_master_session *cms) { struct rtp_packet *pkt; struct cast_session *cs; struct cast_session *next; int len; int ret; // Encode payload into cast_encoded_data len = payload_encode(cast_encoded_data, cms->rawbuf, cms->rawbuf_size, cms->samples_per_packet, &cms->quality); if (len < 0) return -1; // Chromium uses a RTP payload type that is 0xff pkt = rtp_packet_next(cms->rtp_session, CAST_HEADER_SIZE + len, cms->samples_per_packet, 0xff); // Creates Cast header + adds payload ret = packet_prepare(pkt, cast_encoded_data); if (ret < 0) return -1; for (cs = cast_sessions; cs; cs = next) { next = cs->next; if (cs->master_session != cms || !(cs->state & CAST_STATE_F_MEDIA_CONNECTED)) continue; ret = packet_send(cs, pkt); if (ret < 0) { // Downgrade state immediately to avoid further write attempts cs->state = CAST_STATE_MEDIA_LAUNCHED; cast_session_shutdown(cs, CAST_STATE_FAILED); } } // Commits packet to retransmit buffer, and prepares the session for the next packet rtp_packet_commit(cms->rtp_session, pkt); return 0; } /* TODO This does not currently work - need to investigate what sync the devices support static void packets_sync_send(struct cast_master_session *cms, struct timespec pts) { struct rtp_packet *sync_pkt; struct cast_session *cs; struct rtcp_timestamp cur_stamp; struct timespec ts; bool is_sync_time; // Check if it is time send a sync packet to sessions that are already running is_sync_time = rtp_sync_is_time(cms->rtp_session); // (See raop.c for more comments on sync packets) cur_stamp.ts.tv_sec = pts.tv_sec; cur_stamp.ts.tv_nsec = pts.tv_nsec; clock_gettime(CLOCK_MONOTONIC, &ts); cur_stamp.pos = cms->rtp_session->pos + cms->evbuf_samples - cms->output_buffer_samples; for (cs = cast_sessions; cs; cs = cs->next) { if (cs->master_session != cms) continue; // A device has joined and should get an init sync packet if (cs->state == CAST_STATE_MEDIA_CONNECTED) { sync_pkt = rtp_sync_packet_next(cms->rtp_session, &cur_stamp, 0x80); packet_send(cs, sync_pkt); DPRINTF(E_DBG, L_PLAYER, "Start sync packet sent to '%s': cur_pos=%" PRIu32 ", cur_ts=%lu:%lu, now=%lu:%lu, rtptime=%" PRIu32 ",\n", cs->devname, cur_stamp.pos, cur_stamp.ts.tv_sec, cur_stamp.ts.tv_nsec, ts.tv_sec, ts.tv_nsec, cms->rtp_session->pos); } else if (is_sync_time && cs->state == CAST_STATE_MEDIA_STREAMING) { sync_pkt = rtp_sync_packet_next(cms->rtp_session, &cur_stamp, 0x80); packet_send(cs, sync_pkt); } } } */ /* ------------------ INTERFACE FUNCTIONS CALLED BY OUTPUTS.C --------------- */ static int cast_device_start_generic(struct output_device *device, int callback_id, cast_reply_cb reply_cb) { struct cast_session *cs; int ret; cs = cast_session_make(device, AF_INET6, callback_id); if (cs) { ret = cast_msg_send(cs, CONNECT, NULL); if (ret == 0) ret = cast_msg_send(cs, GET_STATUS, reply_cb); if (ret < 0) { DPRINTF(E_WARN, L_CAST, "Could not send CONNECT or GET_STATUS request on IPv6 (start)\n"); cast_session_cleanup(cs); } else return 0; } cs = cast_session_make(device, AF_INET, callback_id); if (!cs) return -1; ret = cast_msg_send(cs, CONNECT, NULL); if (ret == 0) ret = cast_msg_send(cs, GET_STATUS, reply_cb); if (ret < 0) { DPRINTF(E_LOG, L_CAST, "Could not send CONNECT or GET_STATUS request on IPv4 (start)\n"); cast_session_cleanup(cs); return -1; } return 0; } static int cast_device_start(struct output_device *device, int callback_id) { return cast_device_start_generic(device, callback_id, cast_cb_startup_connect); } static int cast_device_probe(struct output_device *device, int callback_id) { return cast_device_start_generic(device, callback_id, cast_cb_probe); } static int cast_device_stop(struct output_device *device, int callback_id) { struct cast_session *cs = device->session; cs->callback_id = callback_id; cast_session_shutdown(cs, CAST_STATE_NONE); return 0; } static int cast_device_flush(struct output_device *device, int callback_id) { struct cast_session *cs = device->session; int ret; if (!(cs->state & CAST_STATE_F_MEDIA_STREAMING)) return -1; // TODO Can't do this, we need to pause the stream in some other way ret = cast_msg_send(cs, MEDIA_PAUSE, cast_cb_flush); if (ret < 0) return -1; cs->callback_id = callback_id; return 0; } static void cast_device_cb_set(struct output_device *device, int callback_id) { struct cast_session *cs = device->session; cs->callback_id = callback_id; } static int cast_device_volume_set(struct output_device *device, int callback_id) { struct cast_session *cs = device->session; int ret; if (!cs || !(cs->state & CAST_STATE_F_MEDIA_CONNECTED)) return 0; cs->volume = 0.01 * device->volume; ret = cast_msg_send(cs, SET_VOLUME, cast_cb_volume); if (ret < 0) { cast_session_shutdown(cs, CAST_STATE_FAILED); return 0; } // Setting it here means it will not be used for the above cast_session_shutdown cs->callback_id = callback_id; return 1; } static void cast_write(struct output_buffer *obuf) { struct cast_master_session *cms; struct cast_session *cs; int i; if (!cast_sessions) return; cms = cast_master_session; for (i = 0; obuf->data[i].buffer; i++) { if (!quality_is_equal(&obuf->data[i].quality, &cast_quality_default)) continue; // Sends sync packets to new sessions, and if it is sync time then also to old sessions // packets_sync_send(cms, obuf->pts); // TODO avoid this copy evbuffer_add(cms->evbuf, obuf->data[i].buffer, obuf->data[i].bufsize); cms->evbuf_samples += obuf->data[i].samples; // Send as many packets as we have data for (one packet requires rawbuf_size bytes) while (evbuffer_get_length(cms->evbuf) >= cms->rawbuf_size) { evbuffer_remove(cms->evbuf, cms->rawbuf, cms->rawbuf_size); cms->evbuf_samples -= cms->samples_per_packet; packets_send(cms); } } // Check for devices that have joined since last write (we have already sent them // initialization sync and rtp packets via packets_sync_send and packets_send) for (cs = cast_sessions; cs; cs = cs->next) { if (cs->state != CAST_STATE_MEDIA_CONNECTED) continue; cs->state = CAST_STATE_MEDIA_STREAMING; // Make a cb? } } static void cast_metadata_send(struct output_metadata *metadata) { struct cast_session *cs; struct cast_session *next; for (cs = cast_sessions; cs; cs = next) { next = cs->next; if (cs->state != CAST_STATE_MEDIA_CONNECTED) continue; metadata_send(cs); } // TODO free the metadata } static int cast_init(void) { struct decode_ctx *decode_ctx; int family; int i; int ret; // Sanity check for (i = 1; cast_msg[i].type; i++) { if (cast_msg[i].type != i) { DPRINTF(E_LOG, L_CAST, "BUG! Cast messages and types are misaligned (type %d!=%d). Could not initialize.\n", cast_msg[i].type, i); return -1; } } // Setting the cert file seems not to be required if ( ((ret = gnutls_global_init()) != GNUTLS_E_SUCCESS) || ((ret = gnutls_certificate_allocate_credentials(&tls_credentials)) != GNUTLS_E_SUCCESS) // || ((ret = gnutls_certificate_set_x509_trust_file(tls_credentials, CAFILE, GNUTLS_X509_FMT_PEM)) < 0) ) { DPRINTF(E_LOG, L_CAST, "Could not initialize GNUTLS: %s\n", gnutls_strerror(ret)); return -1; } decode_ctx = transcode_decode_setup_raw(XCODE_PCM16_48000); if (!decode_ctx) { DPRINTF(E_LOG, L_CAST, "Could not create decoding context\n"); goto out_tls_deinit; } cast_encode_ctx = transcode_encode_setup(XCODE_OPUS, decode_ctx, NULL, 0, 0); transcode_decode_cleanup(&decode_ctx); if (!cast_encode_ctx) { DPRINTF(E_LOG, L_CAST, "Will not be able to stream Chromecast, libav does not support Opus encoding\n"); goto out_tls_deinit; } if (cfg_getbool(cfg_getsec(cfg, "general"), "ipv6")) family = AF_UNSPEC; else family = AF_INET; ret = mdns_browse("_googlecast._tcp", family, cast_device_cb, 0); if (ret < 0) { DPRINTF(E_LOG, L_CAST, "Could not add mDNS browser for Chromecast devices\n"); goto out_encode_ctx_free; } CHECK_NULL(L_CAST, cast_encoded_data = evbuffer_new()); return 0; out_encode_ctx_free: transcode_encode_cleanup(&cast_encode_ctx); out_tls_deinit: gnutls_certificate_free_credentials(tls_credentials); gnutls_global_deinit(); return -1; } static void cast_deinit(void) { struct cast_session *cs; for (cs = cast_sessions; cast_sessions; cs = cast_sessions) { cast_sessions = cs->next; cast_session_free(cs); } evbuffer_free(cast_encoded_data); transcode_encode_cleanup(&cast_encode_ctx); gnutls_certificate_free_credentials(tls_credentials); gnutls_global_deinit(); } struct output_definition output_cast = { .name = "Chromecast", .type = OUTPUT_TYPE_CAST, .priority = 2, .disabled = 0, .init = cast_init, .deinit = cast_deinit, .device_start = cast_device_start, .device_probe = cast_device_probe, .device_stop = cast_device_stop, .device_flush = cast_device_flush, .device_cb_set = cast_device_cb_set, .device_volume_set = cast_device_volume_set, .write = cast_write, // .metadata_prepare = cast_metadata_prepare, .metadata_send = cast_metadata_send, // .metadata_purge = cast_metadata_purge, };