rtpmidi channel spec parsing

3 files changed, 200 insertions, 21 deletions

diff --git a/backends/rtpmidi.c b/backends/rtpmidi.c
index ea97565..4fb0ce0 100644
--- a/backends/rtpmidi.c
+++ b/backends/rtpmidi.c
@@ -35,6 +35,11 @@ int init(){
 		.shutdown = rtpmidi_shutdown
 	};
 
+	if(sizeof(rtpmidi_channel_ident) != sizeof(uint64_t)){
+		fprintf(stderr, "rtpmidi channel identification union out of bounds\n");
+		return 1;
+	}
+
 	if(mm_backend_register(rtpmidi)){
 		fprintf(stderr, "Failed to register rtpmidi backend\n");
 		return 1;
@@ -45,7 +50,6 @@ int init(){
 
 static int rtpmidi_configure(char* option, char* value){
 	char* host = NULL, *port = NULL;
-	char next_port[10];
 
 	if(!strcmp(option, "mdns-name")){
 		if(cfg.mdns_name){
@@ -93,17 +97,170 @@ static int rtpmidi_configure(char* option, char* value){
 }
 
 static int rtpmidi_configure_instance(instance* inst, char* option, char* value){
-	//TODO
+	rtpmidi_instance_data* data = (rtpmidi_instance_data*) inst->impl;
+
+	if(!strcmp(option, "mode")){
+		if(!strcmp(value, "direct")){
+			data->mode = direct;
+			return 0;
+		}
+		else if(!strcmp(value, "apple")){
+			data->mode = apple;
+			return 0;
+		}
+		fprintf(stderr, "Unknown rtpmidi instance mode %s for instance %s\n", value, inst->name);
+		return 1;
+	}
+	else if(!strcmp(option, "ssrc")){
+		data->ssrc = strtoul(value, NULL, 0);
+		if(!data->ssrc){
+			fprintf(stderr, "Random SSRC will be generated for rtpmidi instance %s\n", inst->name);
+		}
+		return 0;
+	}
+	else if(!strcmp(option, "bind")){
+		//TODO set the bind host
+	}
+	else if(!strcmp(option, "learn")){
+		if(data->mode != direct){
+			fprintf(stderr, "The rtpmidi 'learn' option is only valid for direct mode instances\n");
+			return 1;
+		}
+		data->learn_peers = 0;
+		if(!strcmp(value, "true")){
+			data->learn_peers = 1;
+		}
+		return 0;
+	}
+	else if(!strcmp(option, "peer")){
+		if(data->mode != direct){
+			fprintf(stderr, "The rtpmidi 'peer' option is only valid for direct mode instances\n");
+			return 1;
+		}
+
+		//TODO add peer
+		return 0;
+	}
+	else if(!strcmp(option, "session")){
+		if(data->mode != apple){
+			fprintf(stderr, "The rtpmidi 'session' option is only valid for apple mode instances\n");
+			return 1;
+		}
+		free(data->session_name);
+		data->session_name = strdup(value);
+		if(!data->session_name){
+			fprintf(stderr, "Failed to allocate memory\n");
+			return 1;
+		}
+		return 0;
+	}
+	else if(!strcmp(option, "invite")){
+		if(data->mode != apple){
+			fprintf(stderr, "The rtpmidi 'invite' option is only valid for apple mode instances\n");
+			return 1;
+		}
+		free(data->invite_peers);
+		data->invite_peers = strdup(value);
+		if(!data->invite_peers){
+			fprintf(stderr, "Failed to allocate memory\n");
+			return 1;
+		}
+		return 0;
+	}
+	else if(!strcmp(option, "join")){
+		if(data->mode != apple){
+			fprintf(stderr, "The rtpmidi 'join' option is only valid for apple mode instances\n");
+			return 1;
+		}
+		free(data->invite_accept);
+		data->invite_accept = strdup(value);
+		if(!data->invite_accept){
+			fprintf(stderr, "Failed to allocate memory\n");
+			return 1;
+		}
+		return 0;
+	}
+
+	fprintf(stderr, "Unknown rtpmidi instance option %s\n", option);
 	return 1;
 }
 
 static instance* rtpmidi_instance(){
-	//TODO
-	return NULL;
+	rtpmidi_instance_data* data = NULL;
+	instance* inst = mm_instance();
+
+	if(!inst){
+		return NULL;
+	}
+
+	data = calloc(1, sizeof(rtpmidi_instance_data));
+	if(!data){
+		fprintf(stderr, "Failed to allocate memory\n");
+		return NULL;
+	}
+
+	inst->impl = data;
+	return inst;
 }
 
 static channel* rtpmidi_channel(instance* inst, char* spec, uint8_t flags){
-	//TODO
+	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{
+		fprintf(stderr, "Invalid rtpmidi channel specification %s\n", spec);
+		return NULL;
+	}
+
+	ident.fields.channel = strtoul(next_token, &next_token, 10);
+	if(ident.fields.channel > 15){
+		fprintf(stderr, "rtpmidi channel out of range in channel spec %s\n", spec);
+		return NULL;
+	}
+
+	if(*next_token != '.'){
+		fprintf(stderr, "rtpmidi channel specification %s does not conform to channel<X>.<control><Y>\n", 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{
+		fprintf(stderr, "Unknown rtpmidi channel control type in spec %s\n", spec);
+		return NULL;
+	}
+
+	ident.fields.control = strtoul(next_token, NULL, 10);
+
+	if(ident.label){
+		return mm_channel(inst, ident.label, 1);
+	}
 	return NULL;
 }
 
@@ -124,35 +281,37 @@ static int rtpmidi_handle(size_t num, managed_fd* fds){
 }
 
 static int rtpmidi_start(){
-	size_t n, u, p;
+	size_t n, u;
 	int rv = 1;
 	instance** inst = NULL;
 	rtpmidi_instance_data* data = NULL;
 
 	//TODO if mdns name defined and no socket, bind default values
 
+	if(cfg.mdns_fd < 0){
+		fprintf(stderr, "No mDNS discovery interface bound, AppleMIDI session support disabled\n");
+	}
+
 	//fetch all defined instances
 	if(mm_backend_instances(BACKEND_NAME, &n, &inst)){
 		fprintf(stderr, "Failed to fetch instance list\n");
 		return 1;
 	}
 
-	if(!n){
-		free(inst);
-		return 0;
-	}
-
-	if(!cfg.nfds){
-		fprintf(stderr, "Failed to start rtpMIDI backend: no descriptors bound\n");
-		goto bail;
-	}
+	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){
+			fprintf(stderr, "rtpmidi instance %s is missing a mode configuration\n", inst[u]->name);
+			goto bail;
+		}
 
-	if(cfg.mdns_fd < 0){
-		fprintf(stderr, "No mDNS discovery interface bound, APPLEMIDI session support disabled\n");
+		//generate random ssrc's
+		if(!data->ssrc){
+			data->ssrc = rand() << 16 | rand();
+		}
 	}
 
-	//TODO initialize all instances
-
 	rv = 0;
 bail:
 	free(inst);
@@ -160,7 +319,7 @@ bail:
 }
 
 static int rtpmidi_shutdown(){
-	size_t u;
+	//TODO cleanup instance data
 
 	free(cfg.mdns_name);
 	if(cfg.mdns_fd >= 0){
diff --git a/backends/rtpmidi.h b/backends/rtpmidi.h
index af6a189..c076fd0 100644
--- a/backends/rtpmidi.h
+++ b/backends/rtpmidi.h
@@ -16,11 +16,31 @@ static int rtpmidi_shutdown();
 #define RTPMIDI_MDNS_PORT "5353"
 #define RTPMIDI_HEADER_MAGIC htobe16(0x80E1)
 
+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;
diff --git a/backends/rtpmidi.md b/backends/rtpmidi.md
index cea69e2..c84c5b3 100644
--- a/backends/rtpmidi.md
+++ b/backends/rtpmidi.md
@@ -50,7 +50,7 @@ Common instance configuration parameters
 | `bind`	| `10.1.2.1 9001`	| `0.0.0.0 <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,piano`		| none			| Devices to send invitations to when discovered (the special value `*` invites all discovered peers). Setting this option makes the instance a session initiator |
-| `joint`	| `Just Jamming`	| none			| Sessions for which to accept invitations (the special value `*` accepts all invitations). Setting this option makes the instance a session participant |
+| `join`	| `Just Jamming`	| none			| Sessions for which to accept invitations (the special value `*` accepts all invitations). Setting this option makes the instance a session participant |
 
 Note that AppleMIDI session establishment requires mDNS functionality, thus the `mdns-name` global parameter
 (and, depending on your setup, the `mdns-bind` parameter) need to be configured properly.