diff options
| -rw-r--r-- | backends/Makefile | 8 | ||||
| -rw-r--r-- | backends/rtpmidi.c | 1086 | ||||
| -rw-r--r-- | backends/rtpmidi.h | 131 | ||||
| -rw-r--r-- | backends/rtpmidi.md | 89 |
4 files changed, 1312 insertions, 2 deletions
diff --git a/backends/Makefile b/backends/Makefile index e31ff24..8956a20 100644 --- a/backends/Makefile +++ b/backends/Makefile @@ -1,7 +1,7 @@ .PHONY: all clean full LINUX_BACKENDS = midi.so evdev.so -WINDOWS_BACKENDS = artnet.dll osc.dll loopback.dll sacn.dll maweb.dll winmidi.dll openpixelcontrol.dll -BACKENDS = artnet.so osc.so loopback.so sacn.so lua.so maweb.so jack.so openpixelcontrol.so python.so +WINDOWS_BACKENDS = artnet.dll osc.dll loopback.dll sacn.dll maweb.dll winmidi.dll openpixelcontrol.dll rtpmidi.dll +BACKENDS = artnet.so osc.so loopback.so sacn.so lua.so maweb.so jack.so openpixelcontrol.so python.so rtpmidi.dll OPTIONAL_BACKENDS = ola.so BACKEND_LIB = libmmbackend.o @@ -46,6 +46,10 @@ maweb.dll: ADDITIONAL_OBJS += $(BACKEND_LIB) maweb.dll: LDLIBS += -lws2_32 maweb.dll: CFLAGS += -DMAWEB_NO_LIBSSL +rtpmidi.so: ADDITIONAL_OBJS += $(BACKEND_LIB) +rtpmidi.dll: ADDITIONAL_OBJS += $(BACKEND_LIB) +rtpmidi.dll: LDLIBS += -lws2_32 + winmidi.dll: ADDITIONAL_OBJS += $(BACKEND_LIB) winmidi.dll: LDLIBS += -lwinmm -lws2_32 diff --git a/backends/rtpmidi.c b/backends/rtpmidi.c new file mode 100644 index 0000000..c39139a --- /dev/null +++ b/backends/rtpmidi.c @@ -0,0 +1,1086 @@ +#define BACKEND_NAME "rtpmidi" +#define DEBUG + +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <fcntl.h> +#include <ctype.h> + +#include "libmmbackend.h" +#include "rtpmidi.h" + +//TODO learn peer ssrcs +//TODO default session join? +//TODO default mode? +//TODO internal loop mode + +static struct /*_rtpmidi_global*/ { + int mdns_fd; + char* mdns_name; + uint8_t detect; + uint64_t last_service; + + size_t announces; + rtpmidi_announce* announce; +} cfg = { + .mdns_fd = -1, + .mdns_name = NULL, + .detect = 0, + .last_service = 0, + + .announces = 0, + .announce = NULL +}; + +MM_PLUGIN_API int init(){ + backend rtpmidi = { + .name = BACKEND_NAME, + .conf = rtpmidi_configure, + .create = rtpmidi_instance, + .conf_instance = rtpmidi_configure_instance, + .channel = rtpmidi_channel, + .handle = rtpmidi_set, + .process = rtpmidi_handle, + .start = rtpmidi_start, + .shutdown = rtpmidi_shutdown + }; + + if(sizeof(rtpmidi_channel_ident) != sizeof(uint64_t)){ + LOG("Channel identification union out of bounds"); + return 1; + } + + if(mm_backend_register(rtpmidi)){ + LOG("Failed to register backend"); + return 1; + } + + return 0; +} + +static int rtpmidi_configure(char* option, char* value){ + char* host = NULL, *port = NULL; + + if(!strcmp(option, "mdns-name")){ + if(cfg.mdns_name){ + LOG("Duplicate mdns-name assignment"); + return 1; + } + + cfg.mdns_name = strdup(value); + if(!cfg.mdns_name){ + LOG("Failed to allocate memory"); + return 1; + } + return 0; + } + else if(!strcmp(option, "mdns-bind")){ + if(cfg.mdns_fd >= 0){ + LOG( "Only one mDNS discovery bind is supported"); + return 1; + } + + mmbackend_parse_hostspec(value, &host, &port, NULL); + + if(!host){ + LOGPF("Not a valid mDNS bind address: %s", value); + return 1; + } + + cfg.mdns_fd = mmbackend_socket(host, (port ? port : RTPMIDI_MDNS_PORT), SOCK_DGRAM, 1, 1); + if(cfg.mdns_fd < 0){ + LOGPF("Failed to bind mDNS interface: %s", value); + return 1; + } + return 0; + } + else if(!strcmp(option, "detect")){ + cfg.detect = 0; + if(!strcmp(value, "on")){ + cfg.detect = 1; + } + return 0; + } + + LOGPF("Unknown backend configuration option %s", option); + return 1; +} + +static int rtpmidi_bind_instance(rtpmidi_instance_data* data, char* host, char* port){ + struct sockaddr_storage sock_addr = { + 0 + }; + socklen_t sock_len = sizeof(sock_addr); + char control_port[32]; + + //bind to random port if none supplied + data->fd = mmbackend_socket(host, port ? port : "0", SOCK_DGRAM, 1, 0); + if(data->fd < 0){ + return 1; + } + + //bind control port + if(data->mode == apple){ + if(getsockname(data->fd, (struct sockaddr*) &sock_addr, &sock_len)){ + LOGPF("Failed to fetch data port information: %s", strerror(errno)); + return 1; + } + + snprintf(control_port, sizeof(control_port), "%d", be16toh(((struct sockaddr_in*)&sock_addr)->sin_port) - 1); + data->control_fd = mmbackend_socket(host, control_port, SOCK_DGRAM, 1, 0); + if(data->control_fd < 0){ + LOGPF("Failed to bind control port %s", control_port); + return 1; + } + } + + return 0; +} + +static char* rtpmidi_type_name(uint8_t type){ + switch(type){ + case note: + return "note"; + case cc: + return "cc"; + case pressure: + return "pressure"; + case aftertouch: + return "aftertouch"; + case pitchbend: + return "pitch"; + } + return "unknown"; +} + +static int rtpmidi_push_peer(rtpmidi_instance_data* data, struct sockaddr_storage sock_addr, socklen_t sock_len, uint8_t learned, uint8_t connected){ + size_t u, p = data->peers; + + for(u = 0; u < data->peers; u++){ + //check whether the peer is already in the list + if(data->peer[u].active + && sock_len == data->peer[u].dest_len + && !memcmp(&data->peer[u].dest, &sock_addr, sock_len)){ + //if yes, update connection flag (but not learned flag because that doesn't change) + data->peer[u].connected = connected; + return 0; + } + + if(!data->peer[u].active){ + p = u; + } + } + + if(p == data->peers){ + data->peer = realloc(data->peer, (data->peers + 1) * sizeof(rtpmidi_peer)); + if(!data->peer){ + LOG("Failed to allocate memory"); + data->peers = 0; + return 1; + } + data->peers++; + DBGPF("Extending peer registry to %" PRIsize_t " entries", data->peers); + } + + data->peer[p].active = 1; + data->peer[p].learned = learned; + data->peer[p].connected = connected; + data->peer[p].dest = sock_addr; + data->peer[p].dest_len = sock_len; + return 0; +} + +static int rtpmidi_push_invite(instance* inst, char* peer){ + size_t u, p; + + //check whether the instance is already in the announce list + for(u = 0; u < cfg.announces; u++){ + if(cfg.announce[u].inst == inst){ + break; + } + } + + //add to the announce list + if(u == cfg.announces){ + cfg.announce = realloc(cfg.announce, (cfg.announces + 1) * sizeof(rtpmidi_announce)); + if(!cfg.announce){ + LOG("Failed to allocate memory"); + cfg.announces = 0; + return 1; + } + + cfg.announce[u].inst = inst; + cfg.announce[u].invites = 0; + cfg.announce[u].invite = NULL; + + cfg.announces++; + } + + //check whether the peer is already in the invite list + for(p = 0; p < cfg.announce[u].invites; p++){ + if(!strcmp(cfg.announce[u].invite[p], peer)){ + return 0; + } + } + + //extend the invite list + cfg.announce[u].invite = realloc(cfg.announce[u].invite, (cfg.announce[u].invites + 1) * sizeof(char*)); + if(!cfg.announce[u].invite){ + LOG("Failed to allocate memory"); + cfg.announce[u].invites = 0; + return 1; + } + + //append the new invitee + cfg.announce[u].invite[p] = strdup(peer); + if(!cfg.announce[u].invite[p]){ + LOG("Failed to allocate memory"); + return 1; + } + + cfg.announce[u].invites++; + return 0; +} + +static int rtpmidi_configure_instance(instance* inst, char* option, char* value){ + rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl; + char* host = NULL, *port = NULL; + struct sockaddr_storage sock_addr; + socklen_t sock_len = sizeof(sock_addr); + + if(!strcmp(option, "mode")){ + if(!strcmp(value, "direct")){ + data->mode = direct; + return 0; + } + else if(!strcmp(value, "apple")){ + data->mode = apple; + return 0; + } + LOGPF("Unknown instance mode %s for instance %s", value, inst->name); + return 1; + } + else if(!strcmp(option, "ssrc")){ + data->ssrc = strtoul(value, NULL, 0); + if(!data->ssrc){ + LOGPF("Random SSRC will be generated for instance %s", inst->name); + } + return 0; + } + else if(!strcmp(option, "bind")){ + if(data->mode == unconfigured){ + LOGPF("Please specify mode for instance %s before setting bind host", inst->name); + return 1; + } + + mmbackend_parse_hostspec(value, &host, &port, NULL); + + if(!host){ + LOGPF("Could not parse bind host specification %s for instance %s", value, inst->name); + return 1; + } + + return rtpmidi_bind_instance(data, host, port); + } + else if(!strcmp(option, "learn")){ + if(data->mode != direct){ + LOG("'learn' option is only valid for direct mode instances"); + return 1; + } + data->learn_peers = 0; + if(!strcmp(value, "true")){ + data->learn_peers = 1; + } + return 0; + } + else if(!strcmp(option, "peer")){ + if(data->mode == unconfigured){ + LOGPF("Please specify mode for instance %s before configuring peers", inst->name); + return 1; + } + + mmbackend_parse_hostspec(value, &host, &port, NULL); + if(!host || !port){ + LOGPF("Invalid peer %s configured on instance %s", value, inst->name); + return 1; + } + + if(mmbackend_parse_sockaddr(host, port, &sock_addr, &sock_len)){ + LOGPF("Failed to resolve peer %s on instance %s", value, inst->name); + return 1; + } + + //apple peers are specified using the control port, but we want to store the data port as peer + if(data->mode == apple){ + ((struct sockaddr_in*) &sock_addr)->sin_port = be16toh(htobe16(((struct sockaddr_in*) &sock_addr)->sin_port) + 1); + } + + return rtpmidi_push_peer(data, sock_addr, sock_len, 0, 0); + } + else if(!strcmp(option, "session")){ + if(data->mode != apple){ + LOG("'session' option is only valid for apple mode instances"); + return 1; + } + free(data->session_name); + data->session_name = strdup(value); + if(!data->session_name){ + LOG("Failed to allocate memory"); + return 1; + } + return 0; + } + else if(!strcmp(option, "invite")){ + if(data->mode != apple){ + LOG("'invite' option is only valid for apple mode instances"); + return 1; + } + + return rtpmidi_push_invite(inst, value); + } + else if(!strcmp(option, "join")){ + if(data->mode != apple){ + LOG("'join' option is only valid for apple mode instances"); + return 1; + } + free(data->accept); + data->accept = strdup(value); + if(!data->accept){ + LOG("Failed to allocate memory"); + return 1; + } + return 0; + } + + LOGPF("Unknown instance configuration option %s on instance %s", option, inst->name); + return 1; +} + +static instance* rtpmidi_instance(){ + rtpmidi_instance_data* data = NULL; + instance* inst = mm_instance(); + + if(!inst){ + return NULL; + } + + data = calloc(1, sizeof(rtpmidi_instance_data)); + if(!data){ + LOG("Failed to allocate memory"); + return NULL; + } + data->fd = -1; + data->control_fd = -1; + + inst->impl = data; + return inst; +} + +static channel* rtpmidi_channel(instance* inst, char* spec, uint8_t flags){ + char* next_token = spec; + rtpmidi_channel_ident ident = { + .label = 0 + }; + + if(!strncmp(spec, "ch", 2)){ + next_token += 2; + if(!strncmp(spec, "channel", 7)){ + next_token = spec + 7; + } + } + else{ + LOGPF("Invalid channel specification %s", spec); + return NULL; + } + + ident.fields.channel = strtoul(next_token, &next_token, 10); + if(ident.fields.channel > 15){ + LOGPF("Channel out of range in channel spec %s", spec); + return NULL; + } + + if(*next_token != '.'){ + LOGPF("Channel specification %s does not conform to channel<X>.<control><Y>", spec); + return NULL; + } + + next_token++; + + if(!strncmp(next_token, "cc", 2)){ + ident.fields.type = cc; + next_token += 2; + } + else if(!strncmp(next_token, "note", 4)){ + ident.fields.type = note; + next_token += 4; + } + else if(!strncmp(next_token, "pressure", 8)){ + ident.fields.type = pressure; + next_token += 8; + } + else if(!strncmp(next_token, "pitch", 5)){ + ident.fields.type = pitchbend; + } + else if(!strncmp(next_token, "aftertouch", 10)){ + ident.fields.type = aftertouch; + } + else{ + LOGPF("Unknown control type in spec %s", spec); + return NULL; + } + + ident.fields.control = strtoul(next_token, NULL, 10); + + if(ident.label){ + return mm_channel(inst, ident.label, 1); + } + return NULL; +} + +static int rtpmidi_set(instance* inst, size_t num, channel** c, channel_value* v){ + rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl; + uint8_t frame[RTPMIDI_PACKET_BUFFER] = ""; + rtpmidi_header* rtp_header = (rtpmidi_header*) frame; + rtpmidi_command_header* command_header = (rtpmidi_command_header*) (frame + sizeof(rtpmidi_header)); + size_t offset = sizeof(rtpmidi_header) + sizeof(rtpmidi_command_header), u = 0; + uint8_t* payload = frame + offset; + rtpmidi_channel_ident ident; + + rtp_header->vpxcc = RTPMIDI_HEADER_MAGIC; + //some receivers seem to have problems reading rfcs and interpreting the marker bit correctly + rtp_header->mpt = (data->mode == apple ? 0 : 0x80) | RTPMIDI_HEADER_TYPE; + rtp_header->sequence = htobe16(data->sequence++); + rtp_header->timestamp = mm_timestamp() * 10; //just assume 100msec resolution because rfc4695 handwaves it + rtp_header->ssrc = htobe32(data->ssrc); + + //midi command section header + //TODO enable the journal bit here + command_header->flags = 0xA0; //extended length header, first entry in list has dtime + + //midi list + for(u = 0; u < num; u++){ + ident.label = c[u]->ident; + + //encode timestamp + payload[0] = 0; + + //encode midi command + payload[1] = ident.fields.type | ident.fields.channel; + payload[2] = ident.fields.control; + payload[3] = v[u].normalised * 127.0; + + if(ident.fields.type == pitchbend){ + payload[2] = ((int)(v[u].normalised * 16384.0)) & 0x7F; + payload[3] = (((int)(v[u].normalised * 16384.0)) >> 7) & 0x7F; + } + //channel-wide aftertouch is only 2 bytes + else if(ident.fields.type == aftertouch){ + payload[2] = payload[3]; + payload -= 1; + offset -= 1; + } + + payload += 4; + offset += 4; + } + + //update command section length + //FIXME this might overrun, might check the number of events at some point + command_header->flags |= (((offset - sizeof(rtpmidi_header) - sizeof(rtpmidi_command_header)) & 0x0F00) >> 8); + command_header->length = ((offset - sizeof(rtpmidi_header) - sizeof(rtpmidi_command_header)) & 0xFF); + + //TODO journal section + + for(u = 0; u < data->peers; u++){ + if(data->peer[u].active && data->peer[u].connected){ + sendto(data->fd, frame, offset, 0, (struct sockaddr*) &data->peer[u].dest, data->peer[u].dest_len); + } + } + + return 0; +} + +static int rtpmidi_handle_applemidi(instance* inst, int fd, uint8_t* frame, size_t bytes, struct sockaddr_storage* peer, socklen_t peer_len){ + rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl; + uint8_t response[RTPMIDI_PACKET_BUFFER] = ""; + apple_command* command = (apple_command*) frame; + char* session_name = (char*) frame + sizeof(apple_command); + size_t n, u; + + command->command = be16toh(command->command); + + //check command version (except for clock sync and receiver feedback) + if(command->command != apple_sync && command->command != apple_feedback + && be32toh(command->version) != 2){ + LOGPF("Invalid AppleMIDI command version %" PRIu32 " on instance %s", be32toh(command->version), inst->name); + return 0; + } + + if(command->command == apple_invite){ + //check session name + for(n = sizeof(apple_command); n < bytes; n++){ + if(!frame[n]){ + break; + } + + if(!isprint(frame[n])){ + session_name = NULL; + break; + } + } + + //unterminated string + if(n == bytes){ + session_name = NULL; + } + + //FIXME if already in session, reject the invitation + if(data->accept && + (!strcmp(data->accept, "*") || (session_name && !strcmp(session_name, data->accept)))){ + //accept the invitation + LOGPF("Instance %s accepting invitation to session %s%s", inst->name, session_name ? session_name : "UNNAMED", (fd == data->control_fd) ? " (control)":""); + //send accept message + apple_command* accept = (apple_command*) response; + accept->res1 = 0xFFFF; + accept->command = htobe16(apple_accept); + accept->version = htobe32(2); + accept->token = command->token; + accept->ssrc = htobe32(data->ssrc); + //add local name to response + //FIXME might want to use the session name in case it is set + memcpy(response + sizeof(apple_command), cfg.mdns_name ? cfg.mdns_name : RTPMIDI_DEFAULT_NAME, strlen((cfg.mdns_name ? cfg.mdns_name : RTPMIDI_DEFAULT_NAME)) + 1); + sendto(fd, response, sizeof(apple_command) + strlen(cfg.mdns_name ? cfg.mdns_name : RTPMIDI_DEFAULT_NAME) + 1, 0, (struct sockaddr*) peer, peer_len); + + //push peer + if(fd != data->control_fd){ + return rtpmidi_push_peer(data, *peer, peer_len, 1, 1); + } + return 0; + } + else{ + //send reject message + LOGPF("Instance %s rejecting invitation to session %s", inst->name, session_name ? session_name : "UNNAMED"); + apple_command reject = { + .res1 = 0xFFFF, + .command = htobe16(apple_reject), + .version = htobe32(2), + .token = command->token, + .ssrc = htobe32(data->ssrc) + }; + sendto(fd, (uint8_t*) &reject, sizeof(apple_command), 0, (struct sockaddr*) peer, peer_len); + } + return 0; + } + else if(command->command == apple_accept){ + if(fd != data->control_fd){ + LOGPF("Instance %s negotiated new peer", inst->name); + return rtpmidi_push_peer(data, *peer, peer_len, 1, 1); + //FIXME store ssrc, start timesync + } + else{ + //send invite on data fd + LOGPF("Instance %s peer accepted on control port, inviting data port", inst->name); + //FIXME limit max length of session name + apple_command* invite = (apple_command*) response; + invite->res1 = 0xFFFF; + invite->command = htobe16(apple_invite); + invite->version = htobe32(2); + invite->token = command->token; + invite->ssrc = htobe32(data->ssrc); + memcpy(response + sizeof(apple_command), data->session_name ? data->session_name : RTPMIDI_DEFAULT_NAME, strlen((data->session_name ? data->session_name : RTPMIDI_DEFAULT_NAME)) + 1); + //calculate data port + ((struct sockaddr_in*) peer)->sin_port = be16toh(htobe16(((struct sockaddr_in*) peer)->sin_port) + 1); + sendto(data->fd, response, sizeof(apple_command) + strlen(data->session_name ? data->session_name : RTPMIDI_DEFAULT_NAME) + 1, 0, (struct sockaddr*) peer, peer_len); + } + return 0; + } + else if(command->command == apple_reject){ + //just ignore this for now and retry the invitation + } + else if(command->command == apple_leave){ + //remove peer from list - this comes in on the control port, but we need to remove the data port... + ((struct sockaddr_in*) peer)->sin_port = be16toh(htobe16(((struct sockaddr_in*) peer)->sin_port) + 1); + for(u = 0; u < data->peers; u++){ + if(data->peer[u].dest_len == peer_len + && !memcmp(&data->peer[u].dest, peer, peer_len)){ + LOGPF("Instance %s removed peer", inst->name); + //learned peers are marked inactive, configured peers are marked unconnected + if(data->peer[u].learned){ + data->peer[u].active = 0; + } + else{ + data->peer[u].connected = 0; + } + } + } + return 0; + } + else if(command->command == apple_sync){ + //respond with sync answer + memcpy(response, frame, bytes); + apple_sync_frame* sync = (apple_sync_frame*) response; + DBGPF("Incoming sync on instance %s (%d)", inst->name, sync->count); + sync->command = htobe16(apple_sync); + sync->ssrc = htobe32(data->ssrc); + switch(sync->count){ + case 0: + //this happens if we're a participant + sync->count++; + sync->timestamp[1] = htobe64(mm_timestamp() * 10); + break; + case 1: + //this happens if we're an initiator + sync->count++; + sync->timestamp[2] = htobe64(mm_timestamp() * 10); + break; + default: + //ignore this one + return 0; + } + + sendto(fd, response, sizeof(apple_sync_frame), 0, (struct sockaddr*) peer, peer_len); + return 0; + } + else if(command->command == apple_feedback){ + //TODO store this somewhere to properly update the recovery journal + LOGPF("Feedback on instance %s", inst->name); + return 0; + } + else{ + LOGPF("Unknown AppleMIDI session command %04X", command->command); + } + + return 0; +} + +static int rtpmidi_parse(instance* inst, uint8_t* frame, size_t bytes){ + uint16_t length = 0; + size_t offset = 1, decode_time = 0, command_bytes = 0; + uint8_t midi_status = 0; + rtpmidi_channel_ident ident; + channel_value val; + channel* chan = NULL; + + if(!bytes){ + LOGPF("No command section in data on instance %s", inst->name); + return 1; + } + + //calculate midi command section length + length = frame[0] & 0x0F; + if(frame[0] & 0x80){ + //extended header + if(bytes < 2){ + LOGPF("Short command section (%" PRIsize_t " bytes) on %s, missing extended header", bytes, inst->name); + return 1; + } + length <<= 8; + length |= frame[1]; + offset = 2; + } + + command_bytes = offset + length; + DBGPF("%u/%" PRIsize_t " bytes of command section on %s, %s header, %s initial dtime", + length, bytes, inst->name, + (frame[0] & 0x80) ? "extended" : "normal", + (frame[0] & 0x20) ? "has" : "no"); + + if(command_bytes > bytes){ + LOGPF("Short command section on %s, indicated %" PRIsize_t ", had %" PRIsize_t, inst->name, command_bytes, bytes); + return 1; + } + + if(frame[0] & 0x20){ + decode_time = 1; + } + + do{ + //decode (and ignore) delta-time + if(decode_time){ + for(; offset < command_bytes && frame[offset] & 0x80; offset++){ + } + offset++; + } + + //section 3 of rfc6295 states that the first dtime as well as the last command may be omitted + //this may make sense on a low-speed serial line, but on a network... come on. + if(offset >= command_bytes){ + break; + } + + //check for a status byte + //TODO filter sysex + if(frame[offset] & 0x80){ + midi_status = frame[offset]; + offset++; + } + + //having variable encoding in each and every component is super annoying to check for... + if(offset >= command_bytes){ + break; + } + + ident.label = 0; + ident.fields.type = midi_status & 0xF0; + ident.fields.channel = midi_status & 0x0F; + + //single byte command + if(ident.fields.type == aftertouch){ + ident.fields.control = 0; + val.normalised = (double) frame[offset] / 127.0; + offset++; + } + //two-byte command + else{ + offset++; + if(offset >= command_bytes){ + break; + } + + if(ident.fields.type == pitchbend){ + ident.fields.control = 0; + val.normalised = (double)((frame[offset] << 7) | frame[offset - 1]) / 16384.0; + } + else{ + ident.fields.control = frame[offset - 1]; + val.normalised = (double) frame[offset] / 127.0; + } + + //fix-up note off events + if(ident.fields.type == 0x80){ + ident.fields.type = note; + val.normalised = 0; + } + + offset++; + } + + DBGPF("Decoded command type %02X channel %d control %d value %f", + ident.fields.type, ident.fields.channel, ident.fields.control, val.normalised); + + if(cfg.detect){ + if(ident.fields.type == pitchbend || ident.fields.type == aftertouch){ + LOGPF("Incoming data on channel %s.ch%d.%s, value %f", + inst->name, ident.fields.channel, + rtpmidi_type_name(ident.fields.type), val.normalised); + } + else{ + LOGPF("Incoming data on channel %s.ch%d.%s%d, value %f", + inst->name, ident.fields.channel, + rtpmidi_type_name(ident.fields.type), + ident.fields.control, val.normalised); + } + } + + //push event + chan = mm_channel(inst, ident.label, 0); + if(chan){ + mm_channel_event(chan, val); + } + + decode_time = 1; + } while(offset < command_bytes); + + return 0; +} + +static int rtpmidi_handle_data(instance* inst){ + rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl; + uint8_t frame[RTPMIDI_PACKET_BUFFER] = ""; + struct sockaddr_storage sock_addr; + socklen_t sock_len = sizeof(sock_addr); + rtpmidi_header* rtp_header = (rtpmidi_header*) frame; + ssize_t bytes_recv = recvfrom(data->fd, frame, sizeof(frame), 0, (struct sockaddr*) &sock_addr, &sock_len); + size_t u; + + //TODO receive until EAGAIN + if(bytes_recv < 0){ + LOGPF("Failed to receive for instance %s", inst->name); + return 1; + } + + if(bytes_recv < sizeof(rtpmidi_header)){ + LOGPF("Skipping short packet on instance %s", inst->name); + return 0; + } + + //FIXME might want to filter data input from sources that are not registered peers + if(data->mode == apple && rtp_header->vpxcc == 0xFF && rtp_header->mpt == 0xFF){ + return rtpmidi_handle_applemidi(inst, data->fd, frame, bytes_recv, &sock_addr, sock_len); + } + else if(rtp_header->vpxcc != RTPMIDI_HEADER_MAGIC || RTPMIDI_GET_TYPE(rtp_header->mpt) != RTPMIDI_HEADER_TYPE){ + LOGPF("Frame with invalid header magic on %s", inst->name); + return 0; + } + + //parse data + if(rtpmidi_parse(inst, frame + sizeof(rtpmidi_header), bytes_recv - sizeof(rtpmidi_header))){ + //returning errors here fails the core loop, so just return 0 to have some logging + return 0; + } + + //try to learn peers + if(data->learn_peers){ + for(u = 0; u < data->peers; u++){ + if(data->peer[u].active + && data->peer[u].dest_len == sock_len + && !memcmp(&data->peer[u].dest, &sock_addr, sock_len)){ + break; + } + } + + if(u == data->peers){ + LOGPF("Learned new peer on %s", inst->name); + return rtpmidi_push_peer(data, sock_addr, sock_len, 1, 1); + } + } + return 0; +} + +static int rtpmidi_handle_control(instance* inst){ + rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl; + uint8_t frame[RTPMIDI_PACKET_BUFFER] = ""; + struct sockaddr_storage sock_addr; + socklen_t sock_len = sizeof(sock_addr); + ssize_t bytes_recv = recvfrom(data->control_fd, frame, sizeof(frame), 0, (struct sockaddr*) &sock_addr, &sock_len); + + if(bytes_recv < 0){ + LOGPF("Failed to receive on control socket for instance %s", inst->name); + return 1; + } + + //the shortest applemidi packet is still larger than the rtpmidi header, so use that as bar + if(bytes_recv < sizeof(rtpmidi_header)){ + LOGPF("Skipping short packet on control socket of instance %s", inst->name); + return 0; + } + + if(data->mode == apple && frame[0] == 0xFF && frame[1] == 0xFF){ + return rtpmidi_handle_applemidi(inst, data->control_fd, frame, bytes_recv, &sock_addr, sock_len); + } + + LOGPF("Unknown session protocol frame received on instance %s", inst->name); + return 0; +} + +static int rtpmidi_service(){ + size_t n, u, p; + instance** inst = NULL; + rtpmidi_instance_data* data = NULL; + uint8_t frame[RTPMIDI_PACKET_BUFFER] = ""; + struct sockaddr_storage control_peer; + + //prepare commands + apple_sync_frame sync = { + .res1 = 0xFFFF, + .command = htobe16(apple_sync), + .ssrc = 0, + .count = 0, + .timestamp = { + mm_timestamp() * 10 + } + }; + apple_command* invite = (apple_command*) &frame; + invite->res1 = 0xFFFF; + invite->command = htobe16(apple_invite); + invite->version = htobe32(2); + invite->token = ((uint32_t) rand()) << 16 | rand(); + + if(mm_backend_instances(BACKEND_NAME, &n, &inst)){ + LOG("Failed to fetch instances"); + return 1; + } + + //mdns discovery + if(cfg.mdns_fd >= 0){ + //TODO send applemidi discovery packets + } + + for(u = 0; u < n; u++){ + data = (rtpmidi_instance_data*) inst[u]->impl; + + if(data->mode == apple){ + for(p = 0; p < data->peers; p++){ + if(data->peer[p].active && data->peer[p].connected){ + //apple sync + DBGPF("Instance %s initializing sync on peer %" PRIsize_t, inst[u]->name, p); + sync.ssrc = htobe32(data->ssrc); + //calculate remote control port from data port + memcpy(&control_peer, &(data->peer[u].dest), sizeof(control_peer)); + ((struct sockaddr_in*) &control_peer)->sin_port = be16toh(htobe16(((struct sockaddr_in*) &control_peer)->sin_port) - 1); + + sendto(data->control_fd, &sync, sizeof(apple_sync_frame), 0, (struct sockaddr*) &control_peer, data->peer[u].dest_len); + } + else if(data->peer[p].active && !data->peer[p].learned && (mm_timestamp() / 1000) % 10 == 0){ + //try to invite pre-defined unconnected applemidi peers + DBGPF("Instance %s inviting configured peer %" PRIsize_t, inst[u]->name, p); + invite->ssrc = htobe32(data->ssrc); + //calculate remote control port from data port + memcpy(&control_peer, &(data->peer[u].dest), sizeof(control_peer)); + ((struct sockaddr_in*) &control_peer)->sin_port = be16toh(htobe16(((struct sockaddr_in*) &control_peer)->sin_port) - 1); + //append session name to packet + memcpy(frame + sizeof(apple_command), data->session_name ? data->session_name : RTPMIDI_DEFAULT_NAME, strlen((data->session_name ? data->session_name : RTPMIDI_DEFAULT_NAME)) + 1); + + sendto(data->control_fd, invite, sizeof(apple_command) + strlen((data->session_name ? data->session_name : RTPMIDI_DEFAULT_NAME)) + 1, 0, (struct sockaddr*) &control_peer, data->peer[u].dest_len); + } + } + } + } + + free(inst); + return 0; +} + +static int rtpmidi_handle(size_t num, managed_fd* fds){ + size_t u; + int rv = 0; + instance* inst = NULL; + rtpmidi_instance_data* data = NULL; + + //handle service tasks (mdns, clock sync, peer connections) + if(mm_timestamp() - cfg.last_service > RTPMIDI_SERVICE_INTERVAL){ + DBGPF("Performing service tasks, delta %" PRIu64, mm_timestamp() - cfg.last_service); + if(rtpmidi_service()){ + return 1; + } + cfg.last_service = mm_timestamp(); + } + + if(!num){ + return 0; + } + + for(u = 0; u < num; u++){ + if(!fds[u].impl){ + //TODO handle mDNS discovery input + } + else{ + //handle rtp/control input + inst = (instance*) fds[u].impl; + data = (rtpmidi_instance_data*) inst->impl; + if(fds[u].fd == data->fd){ + rv |= rtpmidi_handle_data(inst); + } + else if(fds[u].fd == data->control_fd){ + rv |= rtpmidi_handle_control(inst); + } + else{ + LOG("Signaled for unknown descriptor"); + } + } + } + + return rv; +} + +static int rtpmidi_start(size_t n, instance** inst){ + size_t u, p, fds = 0; + rtpmidi_instance_data* data = NULL; + + //if mdns name defined and no socket, bind default values + if(cfg.mdns_name && cfg.mdns_fd < 0){ + cfg.mdns_fd = mmbackend_socket(RTPMIDI_DEFAULT_HOST, RTPMIDI_MDNS_PORT, SOCK_DGRAM, 1, 1); + if(cfg.mdns_fd < 0){ + return 1; + } + } + + //register mdns fd to core + if(cfg.mdns_fd >= 0){ + if(mm_manage_fd(cfg.mdns_fd, BACKEND_NAME, 1, NULL)){ + LOG("Failed to register mDNS socket with core"); + return 1; + } + fds++; + } + else{ + LOG("No mDNS discovery interface bound, AppleMIDI session discovery disabled"); + } + + for(u = 0; u < n; u++){ + data = (rtpmidi_instance_data*) inst[u]->impl; + //check whether instances are explicitly configured to a mode + if(data->mode == unconfigured){ + LOGPF("Instance %s is missing a mode configuration", inst[u]->name); + return 1; + } + + //generate random ssrc's + if(!data->ssrc){ + data->ssrc = ((uint32_t) rand()) << 16 | rand(); + } + + //if not bound, bind to default + if(data->fd < 0 && rtpmidi_bind_instance(data, RTPMIDI_DEFAULT_HOST, NULL)){ + LOGPF("Failed to bind default sockets for instance %s", inst[u]->name); + return 1; + } + + //mark configured peers on direct instances as connected so output is sent + //apple mode instances go through the session negotiation before marking peers as active + if(data->mode == direct){ + for(p = 0; p < data->peers; p++){ + data->peer[p].connected = 1; + } + } + + //register fds to core + if(mm_manage_fd(data->fd, BACKEND_NAME, 1, inst[u]) || (data->control_fd >= 0 && mm_manage_fd(data->control_fd, BACKEND_NAME, 1, inst[u]))){ + LOGPF("Failed to register descriptor for instance %s with core", inst[u]->name); + return 1; + } + fds += (data->control_fd >= 0) ? 2 : 1; + } + + LOGPF("Registered %" PRIsize_t " descriptors to core", fds); + return 0; +} + +static int rtpmidi_shutdown(size_t n, instance** inst){ + rtpmidi_instance_data* data = NULL; + size_t u, p; + + for(u = 0; u < n; u++){ + data = (rtpmidi_instance_data*) inst[u]->impl; + if(data->fd >= 0){ + close(data->fd); + } + + if(data->control_fd >= 0){ + close(data->control_fd); + } + + free(data->session_name); + data->session_name = NULL; + + free(data->accept); + data->accept = NULL; + + free(data->peer); + data->peer = NULL; + data->peers = 0; + + free(inst[u]->impl); + inst[u]->impl = NULL; + } + + for(u = 0; u < cfg.announces; u++){ + for(p = 0; p < cfg.announce[u].invites; p++){ + free(cfg.announce[u].invite[p]); + } + free(cfg.announce[u].invite); + } + free(cfg.announce); + cfg.announce = NULL; + cfg.announces = 0; + + free(cfg.mdns_name); + cfg.mdns_name = NULL; + if(cfg.mdns_fd >= 0){ + close(cfg.mdns_fd); + } + + LOG("Backend shut down"); + return 0; +} diff --git a/backends/rtpmidi.h b/backends/rtpmidi.h new file mode 100644 index 0000000..db6237b --- /dev/null +++ b/backends/rtpmidi.h @@ -0,0 +1,131 @@ +#ifndef _WIN32 +#include <sys/socket.h> +#endif +#include "midimonster.h" + +MM_PLUGIN_API int init(); +static int rtpmidi_configure(char* option, char* value); +static int rtpmidi_configure_instance(instance* instance, char* option, char* value); +static instance* rtpmidi_instance(); +static channel* rtpmidi_channel(instance* instance, char* spec, uint8_t flags); +static int rtpmidi_set(instance* inst, size_t num, channel** c, channel_value* v); +static int rtpmidi_handle(size_t num, managed_fd* fds); +static int rtpmidi_start(size_t n, instance** inst); +static int rtpmidi_shutdown(size_t n, instance** inst); + +#define RTPMIDI_PACKET_BUFFER 8192 +#define RTPMIDI_DEFAULT_HOST "::" +#define RTPMIDI_MDNS_PORT "5353" +#define RTPMIDI_HEADER_MAGIC 0x80 +#define RTPMIDI_HEADER_TYPE 0x61 +#define RTPMIDI_GET_TYPE(a) ((a) & 0x7F) +#define RTPMIDI_DEFAULT_NAME "MIDIMonster" +#define RTPMIDI_SERVICE_INTERVAL 1000 + +enum /*_rtpmidi_channel_type*/ { + none = 0, + note = 0x90, + cc = 0xB0, + pressure = 0xA0, + aftertouch = 0xD0, + pitchbend = 0xE0 +}; + +typedef enum /*_rtpmidi_instance_mode*/ { + unconfigured = 0, + direct, + apple +} rtpmidi_instance_mode; + +typedef union { + struct { + uint8_t pad[5]; + uint8_t type; + uint8_t channel; + uint8_t control; + } fields; + uint64_t label; +} rtpmidi_channel_ident; + +typedef struct /*_rtpmidi_peer*/ { + struct sockaddr_storage dest; + socklen_t dest_len; + //uint32_t ssrc; + uint8_t active; //marked for reuse + uint8_t learned; //learned / configured peer + uint8_t connected; //currently in active session +} rtpmidi_peer; + +typedef struct /*_rtmidi_instance_data*/ { + rtpmidi_instance_mode mode; + + int fd; + int control_fd; + + size_t peers; + rtpmidi_peer* peer; + uint32_t ssrc; + uint16_t sequence; + + //apple-midi config + char* session_name; /* initiator only */ + char* accept; /* participant only */ + + //direct mode config + uint8_t learn_peers; +} rtpmidi_instance_data; + +typedef struct /*rtpmidi_announced_instance*/ { + instance* inst; + size_t invites; + char** invite; +} rtpmidi_announce; + +enum applemidi_command { + apple_invite = 0x494E, //IN + apple_accept = 0x4F4B, //OK + apple_reject = 0x4E4F, //NO + apple_leave = 0x4259, //BY + apple_sync = 0x434B, //CK + apple_feedback = 0x5253 //RS +}; + +#pragma pack(push, 1) +typedef struct /*_apple_session_command*/ { + uint16_t res1; + uint16_t command; + uint32_t version; + uint32_t token; + uint32_t ssrc; + //char* name +} apple_command; + +typedef struct /*_apple_session_sync*/ { + uint16_t res1; + uint16_t command; + uint32_t ssrc; + uint8_t count; + uint8_t res2[3]; + uint64_t timestamp[3]; +} apple_sync_frame; + +typedef struct /*_apple_session_feedback*/ { + uint16_t res1; + uint8_t command[2]; + uint32_t ssrc; + uint32_t sequence; +} apple_journal_feedback; + +typedef struct /*_rtp_midi_header*/ { + uint8_t vpxcc; + uint8_t mpt; + uint16_t sequence; + uint32_t timestamp; + uint32_t ssrc; +} rtpmidi_header; + +typedef struct /*_rtp_midi_command*/ { + uint8_t flags; + uint8_t length; +} rtpmidi_command_header; +#pragma pack(pop) diff --git a/backends/rtpmidi.md b/backends/rtpmidi.md new file mode 100644 index 0000000..e857a5a --- /dev/null +++ b/backends/rtpmidi.md @@ -0,0 +1,89 @@ +### The `rtpmidi` backend + +This backend provides read-write access to RTP MIDI streams, which transfer MIDI data +over the network. + +As the specification for RTP MIDI does not normatively indicate any method +for session management, most vendors define their own standards for this. +The MIDIMonster supports the following session management methods, which are +selectable per-instance, with some methods requiring additional global configuration: + +* Direct connection: The instance will send and receive data from peers configured in the + instance configuration +* Direct connection with peer learning: The instance will send and receive data from peers + configured in the instance configuration as well as previously unknown peers that + voluntarily send data to the instance. +* AppleMIDI session management: The instance will be able to communicate (either as participant + or initiator) in an AppleMIDI session, which can optionally be announced via mDNS (better + known as "Bonjour" to Apple users). + +Note that instances that receive data from multiple peers will combine all inputs into one +stream, which may lead to inconsistencies during playback. + +#### Global configuration + +| Option | Example value | Default value | Description | +|---------------|-----------------------|-----------------------|-----------------------| +| `detect` | `on` | `off` | Output channel specifications for any events coming in on configured instances to help with configuration | +| `mdns-bind` | `10.1.2.1 5353` | `:: 5353` | Bind host for the mDNS discovery server | +| `mdns-name` | `computer1` | none | mDNS hostname to announce, also used as AppleMIDI peer name | + +#### Instance configuration + +Common instance configuration parameters + +| Option | Example value | Default value | Description | +|---------------|-----------------------|-----------------------|-----------------------| +| `ssrc` | `0xDEADBEEF` | Randomly generated | 32-bit synchronization source identifier | +| `mode` | `direct` | none | Instance session management mode (`direct` or `apple`) | +| `peer` | `10.1.2.3 9001` | none | MIDI session peer, may be specified multiple times. Bypasses session discovery (but still performs session negotiation) | + +`direct` mode instance configuration parameters + +| Option | Example value | Default value | Description | +|---------------|-----------------------|-----------------------|-----------------------| +| `bind` | `10.1.2.1 9001` | `:: <random>` | Local network address to bind to | +| `learn` | `true` | `false` | Accept new peers for data exchange at runtime | + +`apple` mode instance configuration parameters + +| Option | Example value | Default value | Description | +|---------------|-----------------------|-----------------------|-----------------------| +| `bind` | `10.1.2.1 9001` | `:: <random>` | Local network address to bind to (note that AppleMIDI requires two consecutive port numbers to be allocated) | +| `session` | `Just Jamming` | `MIDIMonster` | Session name to announce via mDNS | +| `invite` | `pad` | none | Devices to send invitations to when discovered (the special value `*` invites all discovered peers). Setting this option makes the instance a session initiator. May be specified multiple times | +| `join` | `Just Jamming` | none | Session for which to accept invitations (the special value `*` accepts the first invitation seen). Setting this option makes the instance a session participant | +| `peer` | `10.1.2.3 9001` | none | Configure a direct session peer, bypassing AppleMIDI discovery. May be specified multiple times | + +Note that AppleMIDI session discovery requires mDNS functionality, thus the `mdns-name` global parameter +(and, depending on your setup, the `mdns-bind` parameter) need to be configured properly. + +#### Channel specification + +The `rtpmidi` backend supports mapping different MIDI events to MIDIMonster channels. The currently supported event types are + +* `cc` - Control Changes +* `note` - Note On/Off messages +* `pressure` - Note pressure/aftertouch messages +* `aftertouch` - Channel-wide aftertouch messages +* `pitch` - Channel pitchbend messages + +A MIDIMonster channel is specified using the syntax `channel<channel>.<type><index>`. The shorthand `ch` may be +used instead of the word `channel` (Note that `channel` here refers to the MIDI channel number). + +The `pitch` and `aftertouch` events are channel-wide, thus they can be specified as `channel<channel>.<type>`. + +MIDI channels range from `0` to `15`. Each MIDI channel consists of 128 notes (numbered `0` through `127`), which +additionally each have a pressure control, 128 CC's (numbered likewise), a channel pressure control (also called +'channel aftertouch') and a pitch control which may all be mapped to individual MIDIMonster channels. + +Example mappings: + +``` +rmidi1.ch0.note9 > rmidi2.channel1.cc4 +rmidi1.channel15.pressure1 > rmidi1.channel0.note0 +rmidi1.ch1.aftertouch > rmidi2.ch2.cc0 +rmidi1.ch0.pitch > rmidi2.ch1.pitch +``` + +#### Known bugs / problems |