Initial maweb backend

1 files changed, 695 insertions, 0 deletions

diff --git a/backends/maweb.c b/backends/maweb.c
new file mode 100644
index 0000000..be4c2ac
--- /dev/null
+++ b/backends/maweb.c
@@ -0,0 +1,695 @@
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#ifndef MAWEB_NO_LIBSSL
+#include <openssl/md5.h>
+#endif
+
+#include "libmmbackend.h"
+#include "maweb.h"
+
+#define BACKEND_NAME "maweb"
+#define WS_LEN(a) ((a) & 0x7F)
+#define WS_OP(a) ((a) & 0x0F)
+#define WS_FLAG_FIN 0x80
+#define WS_FLAG_MASK 0x80
+
+static uint64_t last_keepalive = 0;
+
+static char* cmdline_keys[] = {
+	"SET",
+	"PREV",
+	"NEXT",
+	"CLEAR",
+	"FIXTURE_CHANNEL",
+	"FIXTURE_GROUP_PRESET",
+	"EXEC_CUE",
+	"STORE_UPDATE",
+	"OOPS",
+	"ESC",
+	"0",
+	"1",
+	"2",
+	"3",
+	"4",
+	"5",
+	"6",
+	"7",
+	"8",
+	"9",
+	"PUNKT",
+	"PLUS",
+	"MINUS",
+	"THRU",
+	"IF",
+	"AT",
+	"FULL",
+	"HIGH",
+	"ENTER",
+	"OFF",
+	"ON",
+	"ASSIGN",
+	"LABEL",
+	"COPY",
+	"TIME",
+	"PAGE",
+	"MACRO",
+	"DELETE",
+	"GOTO",
+	"GO_PLUS",
+	"GO_MINUS",
+	"PAUSE",
+	"SELECT",
+	"FIXTURE",
+	"SEQU",
+	"CUE",
+	"PRESET",
+	"EDIT",
+	"UPDATE",
+	"EXEC",
+	"STORE",
+	"GROUP",
+	"PROG_ONLY",
+	"SPECIAL_DIALOGUE",
+	"SOLO",
+	"ODD",
+	"EVEN",
+	"WINGS",
+	"RESET",
+	"MA",
+	"layerMode",
+	"featureSort",
+	"fixtureSort",
+	"channelSort",
+	"hideName"
+};
+
+int init(){
+	backend maweb = {
+		.name = BACKEND_NAME,
+		.conf = maweb_configure,
+		.create = maweb_instance,
+		.conf_instance = maweb_configure_instance,
+		.channel = maweb_channel,
+		.handle = maweb_set,
+		.process = maweb_handle,
+		.start = maweb_start,
+		.shutdown = maweb_shutdown
+	};
+
+	if(sizeof(maweb_channel_ident) != sizeof(uint64_t)){
+		fprintf(stderr, "maweb channel identification union out of bounds\n");
+		return 1;
+	}
+
+	//register backend
+	if(mm_backend_register(maweb)){
+		fprintf(stderr, "Failed to register maweb backend\n");
+		return 1;
+	}
+	return 0;
+}
+
+static int maweb_configure(char* option, char* value){
+	fprintf(stderr, "The maweb backend does not take any global configuration\n");
+	return 1;
+}
+
+static int maweb_configure_instance(instance* inst, char* option, char* value){
+	maweb_instance_data* data = (maweb_instance_data*) inst->impl;
+	char* host = NULL, *port = NULL;
+	#ifndef MAWEB_NO_LIBSSL
+	uint8_t password_hash[MD5_DIGEST_LENGTH];
+	#endif
+
+	if(!strcmp(option, "host")){
+		mmbackend_parse_hostspec(value, &host, &port);
+		if(!host){
+			fprintf(stderr, "Invalid host specified for maweb instance %s\n", inst->name);
+			return 1;
+		}
+		free(data->host);
+		data->host = strdup(host);
+		free(data->port);
+		data->port = NULL;
+		if(port){
+			data->port = strdup(port);
+		}
+		return 0;
+	}
+	else if(!strcmp(option, "user")){
+		free(data->user);
+		data->user = strdup(value);
+		return 0;
+	}
+	else if(!strcmp(option, "password")){
+		#ifndef MAWEB_NO_LIBSSL
+		size_t n;
+		MD5((uint8_t*) value, strlen(value), (uint8_t*) password_hash);
+		data->pass = realloc(data->pass, (2 * MD5_DIGEST_LENGTH + 1) * sizeof(char));
+		for(n = 0; n < MD5_DIGEST_LENGTH; n++){
+			snprintf(data->pass + 2 * n, 3, "%02x", password_hash[n]);
+		}
+		return 0;
+		#else
+		fprintf(stderr, "This build of the maweb backend only supports the default password\n");
+		return 1;
+		#endif
+	}
+
+	fprintf(stderr, "Unknown configuration parameter %s for manet instance %s\n", option, inst->name);
+	return 1;
+}
+
+static instance* maweb_instance(){
+	instance* inst = mm_instance();
+	if(!inst){
+		return NULL;
+	}
+
+	maweb_instance_data* data = calloc(1, sizeof(maweb_instance_data));
+	if(!data){
+		fprintf(stderr, "Failed to allocate memory\n");
+		return NULL;
+	}
+
+	data->fd = -1;
+	data->buffer = calloc(MAWEB_RECV_CHUNK, sizeof(uint8_t));
+	if(!data->buffer){
+		fprintf(stderr, "Failed to allocate memory\n");
+		free(data);
+		return NULL;
+	}
+	data->allocated = MAWEB_RECV_CHUNK;
+
+	inst->impl = data;
+	return inst;
+}
+
+static channel* maweb_channel(instance* inst, char* spec){
+	maweb_channel_ident ident = {
+		.label = 0
+	};
+	char* next_token = NULL;
+	size_t n;
+
+	if(!strncmp(spec, "page", 4)){
+		ident.fields.page = strtoul(spec + 4, &next_token, 10);
+		if(*next_token != '.'){
+			fprintf(stderr, "Failed to parse maweb channel spec %s: Missing separator\n", spec);
+			return NULL;
+		}
+
+		next_token++;
+		if(!strncmp(next_token, "fader", 5)){
+			ident.fields.type = exec_fader;
+			next_token += 5;
+		}
+		else if(!strncmp(next_token, "upper", 5)){
+			ident.fields.type = exec_upper;
+			next_token += 5;
+		}
+		else if(!strncmp(next_token, "lower", 5)){
+			ident.fields.type = exec_lower;
+			next_token += 5;
+		}
+		else if(!strncmp(next_token, "flash", 5)){
+			ident.fields.type = exec_flash;
+			next_token += 5;
+		}
+		else if(!strncmp(next_token, "button", 6)){
+			ident.fields.type = exec_fader;
+			next_token += 6;
+		}
+		ident.fields.index = strtoul(next_token, NULL, 10);
+	}
+	else{
+		for(n = 0; n < sizeof(cmdline_keys) / sizeof(char*); n++){
+			if(!strcmp(spec, cmdline_keys[n])){
+				ident.fields.type = cmdline_button;
+				ident.fields.index = n + 1;
+				ident.fields.page = 1;
+				break;
+			}
+		}
+	}
+
+	if(ident.fields.type && ident.fields.index && ident.fields.page
+			&& ident.fields.index <= 90){
+		//actually, those are zero-indexed...
+		ident.fields.index--;
+		ident.fields.page--;
+		return mm_channel(inst, ident.label, 1);
+	}
+	fprintf(stderr, "Failed to parse maweb channel spec %s\n", spec);
+	return NULL;
+}
+
+static int maweb_send_frame(instance* inst, maweb_operation op, uint8_t* payload, size_t len){
+	maweb_instance_data* data = (maweb_instance_data*) inst->impl;
+	uint8_t frame_header[MAWEB_FRAME_HEADER_LENGTH] = "";
+	size_t header_bytes = 2;
+	uint16_t* payload_len16 = (uint16_t*) (frame_header + 2);
+	uint64_t* payload_len64 = (uint64_t*) (frame_header + 2);
+
+	frame_header[0] = WS_FLAG_FIN | op;
+	if(len <= 125){
+		frame_header[1] = WS_FLAG_MASK | len;
+	}
+	else if(len <= 0xFFFF){
+		frame_header[1] = WS_FLAG_MASK | 126;
+		*payload_len16 = htobe16(len);
+		header_bytes += 2;
+	}
+	else{
+		frame_header[1] = WS_FLAG_MASK | 127;
+		*payload_len64 = htobe64(len);
+		header_bytes += 8;
+	}
+	//send a zero masking key because masking is stupid
+	header_bytes += 4;
+
+	if(mmbackend_send(data->fd, frame_header, header_bytes)
+			|| mmbackend_send(data->fd, payload, len)){
+		return 1;
+	}
+
+	return 0;
+}
+
+static int maweb_handle_message(instance* inst, char* payload, size_t payload_length){
+	char xmit_buffer[MAWEB_XMIT_CHUNK];
+	char* field;
+	maweb_instance_data* data = (maweb_instance_data*) inst->impl;
+
+	fprintf(stderr, "maweb message (%lu): %s\n", payload_length, payload);
+	if(json_obj(payload, "session") == JSON_NUMBER){
+		data->session = json_obj_int(payload, "session", data->session);
+		fprintf(stderr, "maweb session id is now %ld\n", data->session);
+	}
+
+	if(json_obj_bool(payload, "forceLogin", 0)){
+		fprintf(stderr, "maweb sending user credentials\n");
+		snprintf(xmit_buffer, sizeof(xmit_buffer),
+				"{\"requestType\":\"login\",\"username\":\"%s\",\"password\":\"%s\",\"session\":%ld}",
+				data->user, data->pass, data->session);
+		maweb_send_frame(inst, ws_text, (uint8_t*) xmit_buffer, strlen(xmit_buffer));
+	}
+
+	if(json_obj(payload, "status") && json_obj(payload, "appType")){
+		fprintf(stderr, "maweb connection established\n");
+		maweb_send_frame(inst, ws_text, (uint8_t*) "{\"session\":0}", 13);
+	}
+
+	if(json_obj(payload, "responseType") == JSON_STRING){
+		field = json_obj_str(payload, "responseType", NULL);
+		if(!strncmp(field, "login", 5)){
+			if(json_obj_bool(payload, "result", 0)){
+				fprintf(stderr, "maweb login successful\n");
+				data->login = 1;
+			}
+			else{
+				fprintf(stderr, "maweb login failed\n");
+				data->login = 0;
+			}
+		}
+		else if(!strncmp(field, "getdata", 7)){
+			//FIXME stupid keepalive logic
+			snprintf(xmit_buffer, sizeof(xmit_buffer),
+					"{\"requestType\":\"getdata\","
+					"\"data\":\"set,clear,solo,high\","
+					"\"realtime\":true,"
+					"\"maxRequests\":10,"
+					",\"session\":%ld}",
+					data->session);
+			maweb_send_frame(inst, ws_text, (uint8_t*) xmit_buffer, strlen(xmit_buffer));
+		}
+	}
+
+	return 0;
+}
+
+static int maweb_connect(instance* inst){
+	maweb_instance_data* data = (maweb_instance_data*) inst->impl;
+	if(!data->host){
+		return 1;
+	}
+
+	//unregister old fd from core
+	if(data->fd >= 0){
+		mm_manage_fd(data->fd, BACKEND_NAME, 0, NULL);
+	}
+
+	data->fd = mmbackend_socket(data->host, data->port ? data->port : MAWEB_DEFAULT_PORT, SOCK_STREAM, 0, 0);
+	if(data->fd < 0){
+		return 1;
+	}
+
+	data->state = ws_new;
+	if(mmbackend_send_str(data->fd, "GET /?ma=1 HTTP/1.1\r\n")
+			|| mmbackend_send_str(data->fd, "Connection: Upgrade\r\n")
+			|| mmbackend_send_str(data->fd, "Upgrade: websocket\r\n")
+			|| mmbackend_send_str(data->fd, "Sec-WebSocket-Version: 13\r\n")
+			//the websocket key probably should not be hardcoded, but this is not security criticial
+			//and the whole websocket 'accept key' dance is plenty stupid as it is
+			|| mmbackend_send_str(data->fd, "Sec-WebSocket-Key: rbEQrXMEvCm4ZUjkj6juBQ==\r\n")
+			|| mmbackend_send_str(data->fd, "\r\n")){
+		fprintf(stderr, "maweb backend failed to communicate with peer\n");
+		return 1;
+	}
+
+	//register new fd
+	if(mm_manage_fd(data->fd, BACKEND_NAME, 1, (void*) inst)){
+		fprintf(stderr, "maweb backend failed to register fd\n");
+		return 1;
+	}
+	return 0;
+}
+
+static ssize_t maweb_handle_lines(instance* inst, ssize_t bytes_read){
+	maweb_instance_data* data = (maweb_instance_data*) inst->impl;
+	size_t n, begin = 0;
+
+	for(n = 0; n < bytes_read - 2; n++){
+		if(!strncmp((char*) data->buffer + data->offset + n, "\r\n", 2)){
+			if(data->state == ws_new){
+				if(!strncmp((char*) data->buffer, "HTTP/1.1 101", 12)){
+					data->state = ws_http;
+				}
+				else{
+					fprintf(stderr, "maweb received invalid HTTP response for instance %s\n", inst->name);
+					return -1;
+				}
+			}
+			else{
+				//ignore all http stuff until the end of headers since we don't actually care...
+				if(n == begin){
+					data->state = ws_open;
+				}
+			}
+			begin = n + 2;
+		}
+	}
+
+	return begin;
+}
+
+static ssize_t maweb_handle_ws(instance* inst, ssize_t bytes_read){
+	maweb_instance_data* data = (maweb_instance_data*) inst->impl;
+	size_t header_length = 2;
+	uint64_t payload_length = 0;
+	uint16_t* payload_len16 = (uint16_t*) (data->buffer + 2);
+	uint64_t* payload_len64 = (uint64_t*) (data->buffer + 2);
+	uint8_t* payload = data->buffer + 2;
+	uint8_t terminator_temp = 0;
+
+	if(data->offset + bytes_read < 2){
+		return 0;
+	}
+
+	//using varint as payload length is stupid, but some people seem to think otherwise...
+	payload_length = WS_LEN(data->buffer[1]);
+	switch(payload_length){
+		case 126:
+			if(data->offset + bytes_read < 4){
+				return 0;
+			}
+			payload_length = htobe16(*payload_len16);
+			payload = data->buffer + 4;
+			header_length = 4;
+			break;
+		case 127:
+			if(data->offset + bytes_read < 10){
+				return 0;
+			}
+			payload_length = htobe64(*payload_len64);
+			payload = data->buffer + 10;
+			header_length = 10;
+			break;
+		default:
+			break;
+	}
+
+	if(data->offset + bytes_read < header_length + payload_length){
+		return 0;
+	}
+
+	switch(WS_OP(data->buffer[0])){
+		case ws_text:
+			//terminate message
+			terminator_temp = payload[payload_length];
+			payload[payload_length] = 0;
+			if(maweb_handle_message(inst, (char*) payload, payload_length)){
+				return data->offset + bytes_read;
+			}
+			payload[payload_length] = terminator_temp;
+			break;
+		case ws_ping:
+			//answer server ping with a pong
+			if(maweb_send_frame(inst, ws_pong, payload, payload_length)){
+				fprintf(stderr, "maweb failed to send pong\n");
+			}
+			return header_length + payload_length;
+		default:
+			fprintf(stderr, "maweb encountered unhandled frame type %02X\n", WS_OP(data->buffer[0]));
+			//this is somewhat dicey, it might be better to handle only header + payload length for known but unhandled types
+			return data->offset + bytes_read;
+	}
+
+	return header_length + payload_length;
+}
+
+static int maweb_handle_fd(instance* inst){
+	maweb_instance_data* data = (maweb_instance_data*) inst->impl;
+	ssize_t bytes_read, bytes_left = data->allocated - data->offset, bytes_handled;
+
+	if(bytes_left < 3){
+		data->buffer = realloc(data->buffer, (data->allocated + MAWEB_RECV_CHUNK) * sizeof(uint8_t));
+		if(!data->buffer){
+			fprintf(stderr, "Failed to allocate memory\n");
+			return 1;
+		}
+		data->allocated += MAWEB_RECV_CHUNK;
+		bytes_left += MAWEB_RECV_CHUNK;
+	}
+
+	bytes_read = recv(data->fd, data->buffer + data->offset, bytes_left - 1, 0);
+	if(bytes_read < 0){
+		fprintf(stderr, "maweb backend failed to receive: %s\n", strerror(errno));
+		//TODO close, reopen
+		return 1;
+	}
+	else if(bytes_read == 0){
+		//client closed connection
+		//TODO try to reopen
+		return 0;
+	}
+
+	do{
+		switch(data->state){
+			case ws_new:
+			case ws_http:
+				bytes_handled = maweb_handle_lines(inst, bytes_read);
+				break;
+			case ws_open:
+				bytes_handled = maweb_handle_ws(inst, bytes_read);
+				break;
+			case ws_closed:
+				bytes_handled = data->offset + bytes_read;
+				break;
+		}
+
+		if(bytes_handled < 0){
+			bytes_handled = data->offset + bytes_read;
+			//TODO close, reopen
+			fprintf(stderr, "maweb failed to handle incoming data\n");
+			return 1;
+		}
+		else if(bytes_handled == 0){
+			 break;
+		}
+
+		memmove(data->buffer, data->buffer + bytes_handled, (data->offset + bytes_read) - bytes_handled);
+
+		//FIXME this might be somewhat borked
+		bytes_read -= data->offset;
+		bytes_handled -= data->offset;
+		bytes_read -= bytes_handled;
+		data->offset = 0;
+	} while(bytes_read > 0);
+
+	data->offset += bytes_read;
+	return 0;
+}
+
+static int maweb_set(instance* inst, size_t num, channel** c, channel_value* v){
+	maweb_instance_data* data = (maweb_instance_data*) inst->impl;
+	char xmit_buffer[MAWEB_XMIT_CHUNK];
+	maweb_channel_ident ident;
+	size_t n;
+
+	if(num && !data->login){
+		fprintf(stderr, "maweb instance %s can not send output, not logged in\n", inst->name);
+	}
+
+	for(n = 0; n < num; n++){
+		ident.label = c[n]->ident;
+		switch(ident.fields.type){
+			case exec_fader:
+				snprintf(xmit_buffer, sizeof(xmit_buffer),
+						"{\"requestType\":\"playbacks_userInput\","
+						"\"execIndex\":%d,"
+						"\"pageIndex\":%d,"
+						"\"faderValue\":%f,"
+						"\"type\":1,"
+						"\"session\":%ld"
+						"}", ident.fields.index, ident.fields.page, v[n].normalised, data->session);
+				fprintf(stderr, "maweb out %s\n", xmit_buffer);
+				maweb_send_frame(inst, ws_text, (uint8_t*) xmit_buffer, strlen(xmit_buffer));
+				break;
+			case exec_upper:
+			case exec_lower:
+			case exec_flash:
+				snprintf(xmit_buffer, sizeof(xmit_buffer),
+						"{\"requestType\":\"playbacks_userInput\","
+						//"\"cmdline\":\"\","
+						"\"execIndex\":%d,"
+						"\"pageIndex\":%d,"
+						"\"buttonId\":%d,"
+						"\"pressed\":%s,"
+						"\"released\":%s,"
+						"\"type\":0,"
+						"\"session\":%ld"
+						"}", ident.fields.index, ident.fields.page,
+						(exec_flash - ident.fields.type),
+						(v[n].normalised > 0.9) ? "true" : "false",
+						(v[n].normalised > 0.9) ? "false" : "true",
+						data->session);
+				fprintf(stderr, "maweb out %s\n", xmit_buffer);
+				maweb_send_frame(inst, ws_text, (uint8_t*) xmit_buffer, strlen(xmit_buffer));
+				break;
+			case cmdline_button:
+				snprintf(xmit_buffer, sizeof(xmit_buffer),
+						"{\"keyname\":\"%s\","
+						//"\"autoSubmit\":false,"
+						"\"value\":%d"
+						"}", cmdline_keys[ident.fields.index],
+						(v[n].normalised > 0.9) ? 1 : 0);
+				fprintf(stderr, "maweb out %s\n", xmit_buffer);
+				maweb_send_frame(inst, ws_text, (uint8_t*) xmit_buffer, strlen(xmit_buffer));
+				break;
+			default:
+				fprintf(stderr, "maweb control not yet implemented\n");
+				break;
+		}
+	}
+	return 0;
+}
+
+static int maweb_keepalive(){
+	size_t n, u;
+	instance** inst = NULL;
+	maweb_instance_data* data = NULL;
+	char xmit_buffer[MAWEB_XMIT_CHUNK];
+
+	//fetch all defined instances
+	if(mm_backend_instances(BACKEND_NAME, &n, &inst)){
+		fprintf(stderr, "Failed to fetch instance list\n");
+		return 1;
+	}
+
+	//send keep-alive messages for logged-in instances
+	for(u = 0; u < n; u++){
+		data = (maweb_instance_data*) inst[u]->impl;
+		if(data->login){
+			snprintf(xmit_buffer, sizeof(xmit_buffer), "{\"session\":%ld}", data->session);
+			maweb_send_frame(inst[u], ws_text, (uint8_t*) xmit_buffer, strlen(xmit_buffer));
+		}
+	}
+
+	free(inst);
+	return 0;
+}
+
+static int maweb_handle(size_t num, managed_fd* fds){
+	size_t n = 0;
+	int rv = 0;
+
+	for(n = 0; n < num; n++){
+		rv |= maweb_handle_fd((instance*) fds[n].impl);
+	}
+
+	if(last_keepalive && mm_timestamp() - last_keepalive >= MAWEB_CONNECTION_KEEPALIVE){
+		rv |= maweb_keepalive();
+		last_keepalive = mm_timestamp();
+	}
+
+	return rv;
+}
+
+static int maweb_start(){
+	size_t n, u;
+	instance** inst = NULL;
+
+	//fetch all defined instances
+	if(mm_backend_instances(BACKEND_NAME, &n, &inst)){
+		fprintf(stderr, "Failed to fetch instance list\n");
+		return 1;
+	}
+
+	for(u = 0; u < n; u++){
+		if(maweb_connect(inst[u])){
+			fprintf(stderr, "Failed to open connection to MA Web Remote for instance %s\n", inst[u]->name);
+			return 1;
+		}
+	}
+
+	free(inst);
+	if(!n){
+		return 0;
+	}
+
+	fprintf(stderr, "maweb backend registering %lu descriptors to core\n", n);
+
+	//initialize keepalive timeout
+	last_keepalive = mm_timestamp();
+	return 0;
+}
+
+static int maweb_shutdown(){
+	size_t n, u;
+	instance** inst = NULL;
+	maweb_instance_data* data = NULL;
+
+	//fetch all instances
+	if(mm_backend_instances(BACKEND_NAME, &n, &inst)){
+		fprintf(stderr, "Failed to fetch instance list\n");
+		return 1;
+	}
+
+	for(u = 0; u < n; u++){
+		data = (maweb_instance_data*) inst[u]->impl;
+		free(data->host);
+		data->host = NULL;
+		free(data->port);
+		data->port = NULL;
+		free(data->user);
+		data->user = NULL;
+		free(data->pass);
+		data->pass = NULL;
+
+		close(data->fd);
+		data->fd = -1;
+
+		free(data->buffer);
+		data->buffer = NULL;
+
+		data->offset = data->allocated = 0;
+		data->state = ws_new;
+	}
+
+	free(inst);
+
+	fprintf(stderr, "maweb backend shut down\n");
+	return 0;
+}