1 files changed, 583 insertions, 0 deletions
diff --git a/backends/libmmbackend.c b/backends/libmmbackend.c
new file mode 100644
index 0000000..ccbeb52
--- /dev/null
+++ b/backends/libmmbackend.c
@@ -0,0 +1,583 @@
+#include "libmmbackend.h"
+
+void mmbackend_parse_hostspec(char* spec, char** host, char** port){
+	size_t u = 0;
+
+	if(!spec || !host || !port){
+		return;
+	}
+
+	*port = NULL;
+
+	//skip leading spaces
+	for(; spec[u] && isspace(spec[u]); u++){
+	}
+
+	if(!spec[u]){
+		*host = NULL;
+		return;
+	}
+
+	*host = spec + u;
+
+	//scan until string end or space
+	for(; spec[u] && !isspace(spec[u]); u++){
+	}
+
+	//if space, the rest should be the port
+	if(spec[u]){
+		spec[u] = 0;
+		*port = spec + u + 1;
+	}
+}
+
+int mmbackend_parse_sockaddr(char* host, char* port, struct sockaddr_storage* addr, socklen_t* len){
+	struct addrinfo* head;
+	struct addrinfo hints = {
+		.ai_family = AF_UNSPEC
+	};
+
+	int error = getaddrinfo(host, port, &hints, &head);
+	if(error || !head){
+		fprintf(stderr, "Failed to parse address %s port %s: %s\n", host, port, gai_strerror(error));
+		return 1;
+	}
+
+	memcpy(addr, head->ai_addr, head->ai_addrlen);
+	if(len){
+		*len = head->ai_addrlen;
+	}
+
+	freeaddrinfo(head);
+	return 0;
+}
+
+int mmbackend_socket(char* host, char* port, int socktype, uint8_t listener, uint8_t mcast){
+	int fd = -1, status, yes = 1;
+	struct addrinfo hints = {
+		.ai_family = AF_UNSPEC,
+		.ai_socktype = socktype,
+		.ai_flags = (listener ? AI_PASSIVE : 0)
+	};
+	struct addrinfo *info, *addr_it;
+
+	status = getaddrinfo(host, port, &hints, &info);
+	if(status){
+		fprintf(stderr, "Failed to parse address %s port %s: %s\n", host, port, gai_strerror(status));
+		return -1;
+	}
+
+	//traverse the result list
+	for(addr_it = info; addr_it; addr_it = addr_it->ai_next){
+		fd = socket(addr_it->ai_family, addr_it->ai_socktype, addr_it->ai_protocol);
+		if(fd < 0){
+			continue;
+		}
+
+		//set required socket options
+		yes = 1;
+		if(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (void*)&yes, sizeof(yes)) < 0){
+			fprintf(stderr, "Failed to enable SO_REUSEADDR on socket\n");
+		}
+
+		if(mcast){
+			yes = 1;
+			if(setsockopt(fd, SOL_SOCKET, SO_BROADCAST, (void*)&yes, sizeof(yes)) < 0){
+				fprintf(stderr, "Failed to enable SO_BROADCAST on socket\n");
+			}
+
+			yes = 0;
+			if(setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, (void*)&yes, sizeof(yes)) < 0){
+				fprintf(stderr, "Failed to disable IP_MULTICAST_LOOP on socket: %s\n", strerror(errno));
+			}
+		}
+
+		if(listener){
+			status = bind(fd, addr_it->ai_addr, addr_it->ai_addrlen);
+			if(status < 0){
+				close(fd);
+				continue;
+			}
+		}
+		else{
+			status = connect(fd, addr_it->ai_addr, addr_it->ai_addrlen);
+			if(status < 0){
+				close(fd);
+				continue;
+			}
+		}
+
+		break;
+	}
+	freeaddrinfo(info);
+
+	if(!addr_it){
+		fprintf(stderr, "Failed to create socket for %s port %s\n", host, port);
+		return -1;
+	}
+
+	//set nonblocking
+	#ifdef _WIN32
+	u_long mode = 1;
+	if(ioctlsocket(fd, FIONBIO, &mode) != NO_ERROR){
+		closesocket(fd);
+		return 1;
+	}
+	#else
+	int flags = fcntl(fd, F_GETFL, 0);
+	if(fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0){
+		fprintf(stderr, "Failed to set socket nonblocking\n");
+		close(fd);
+		return -1;
+	}
+	#endif
+
+	return fd;
+}
+
+int mmbackend_send(int fd, uint8_t* data, size_t length){
+	ssize_t total = 0, sent;
+	while(total < length){
+		sent = send(fd, data + total, length - total, 0);
+		if(sent < 0){
+			fprintf(stderr, "Failed to send: %s\n", strerror(errno));
+			return 1;
+		}
+		total += sent;
+	}
+	return 0;
+}
+
+int mmbackend_send_str(int fd, char* data){
+	return mmbackend_send(fd, (uint8_t*) data, strlen(data));
+}
+
+json_type json_identify(char* json, size_t length){
+	size_t n;
+
+	//skip leading blanks
+	for(n = 0; json[n] && n < length && isspace(json[n]); n++){
+	}
+
+	if(n == length){
+		return JSON_INVALID;
+	}
+
+	switch(json[n]){
+		case '{':
+			return JSON_OBJECT;
+		case '[':
+			return JSON_ARRAY;
+		case '"':
+			return JSON_STRING;
+		case '-':
+		case '+':
+			return JSON_NUMBER;
+		default:
+			//true false null number
+			if(!strncmp(json + n, "true", 4)
+					|| !strncmp(json + n, "false", 5)){
+				return JSON_BOOL;
+			}
+			else if(!strncmp(json + n, "null", 4)){
+				return JSON_NULL;
+			}
+			//a bit simplistic but it should do
+			if(isdigit(json[n])){
+				return JSON_NUMBER;
+			}
+	}
+	return JSON_INVALID;
+}
+
+size_t json_validate(char* json, size_t length){
+	switch(json_identify(json, length)){
+		case JSON_STRING:
+			return json_validate_string(json, length);
+		case JSON_ARRAY:
+			return json_validate_array(json, length);
+		case JSON_OBJECT:
+			return json_validate_object(json, length);
+		case JSON_INVALID:
+			return 0;
+		default:
+			return json_validate_value(json, length);
+	}
+}
+
+size_t json_validate_string(char* json, size_t length){
+	size_t string_length = 0, offset;
+
+	//skip leading whitespace
+	for(offset = 0; json[offset] && offset < length && isspace(json[offset]); offset++){
+	}
+
+	if(offset == length || json[offset] != '"'){
+		return 0;
+	}
+
+	//find terminating quotation mark not preceded by escape
+	for(string_length = 1; offset + string_length < length
+			&& isprint(json[offset + string_length])
+			&& (json[offset + string_length] != '"' || json[offset + string_length - 1] == '\\'); string_length++){
+	}
+
+	//complete string found
+	if(json[offset + string_length] == '"' && json[offset + string_length - 1] != '\\'){
+		return offset + string_length + 1;
+	}
+
+	return 0;
+}
+
+size_t json_validate_array(char* json, size_t length){
+	size_t offset = 0;
+
+	//skip leading whitespace
+	for(offset = 0; json[offset] && offset < length && isspace(json[offset]); offset++){
+	}
+
+	if(offset == length || json[offset] != '['){
+		return 0;
+	}
+
+	for(offset++; offset < length; offset++){
+		offset += json_validate(json + offset, length - offset);
+
+		//skip trailing whitespace, find terminator
+		for(; offset < length && isspace(json[offset]); offset++){
+		}
+
+		if(json[offset] == ','){
+			continue;
+		}
+
+		if(json[offset] == ']'){
+			return offset + 1;
+		}
+
+		break;
+	}
+
+	return 0;
+}
+
+size_t json_validate_object(char* json, size_t length){
+	size_t offset = 0;
+
+	//skip whitespace
+	for(offset = 0; json[offset] && isspace(json[offset]); offset++){
+	}
+
+	if(offset == length || json[offset] != '{'){
+		return 0;
+	}
+
+	for(offset++; offset < length; offset++){
+		if(json_identify(json + offset, length - offset) != JSON_STRING){
+			//still could be an empty object...
+			for(; offset < length && isspace(json[offset]); offset++){
+			}
+			if(json[offset] == '}'){
+				return offset + 1;
+			}
+			return 0;
+		}
+		offset += json_validate(json + offset, length - offset);
+
+		//find value separator
+		for(; offset < length && isspace(json[offset]); offset++){
+		}
+
+		if(json[offset] != ':'){
+			return 0;
+		}
+
+		offset++;
+		offset += json_validate(json + offset, length - offset);
+
+		//skip trailing whitespace
+		for(; json[offset] && isspace(json[offset]); offset++){
+		}
+
+		if(json[offset] == '}'){
+			return offset + 1;
+		}
+		else if(json[offset] != ','){
+			return 0;
+		}
+	}
+	return 0;
+}
+
+size_t json_validate_value(char* json, size_t length){
+	size_t offset = 0, value_length;
+
+	//skip leading whitespace
+	for(offset = 0; json[offset] && offset < length && isspace(json[offset]); offset++){
+	}
+
+	if(offset == length){
+		return 0;
+	}
+
+	//match complete values
+	if(length - offset >= 4 && !strncmp(json + offset, "null", 4)){
+		return offset + 4;
+	}
+	else if(length - offset >= 4 && !strncmp(json + offset, "true", 4)){
+		return offset + 4;
+	}
+	else if(length - offset >= 5 && !strncmp(json + offset, "false", 5)){
+		return offset + 5;
+	}
+
+	if(json[offset] == '-' || isdigit(json[offset])){
+		//json number parsing is dumb.
+		for(value_length = 1; offset + value_length < length &&
+					(isdigit(json[offset + value_length])
+					|| json[offset + value_length] == '+'
+					|| json[offset + value_length] == '-'
+					|| json[offset + value_length] == '.'
+					|| tolower(json[offset + value_length]) == 'e'); value_length++){
+		}
+
+		if(value_length > 0){
+			return offset + value_length;
+		}
+	}
+
+	return 0;
+}
+
+size_t json_obj_offset(char* json, char* key){
+	size_t offset = 0;
+	uint8_t match = 0;
+
+	//skip whitespace
+	for(offset = 0; json[offset] && isspace(json[offset]); offset++){
+	}
+
+	if(json[offset] != '{'){
+		return 0;
+	}
+	offset++;
+
+	while(json_identify(json + offset, strlen(json + offset)) == JSON_STRING){
+		//skip to key begin
+		for(; json[offset] && json[offset] != '"'; offset++){
+		}
+
+		if(!strncmp(json + offset + 1, key, strlen(key)) && json[offset + 1 + strlen(key)] == '"'){
+			//key found
+			match = 1;
+		}
+
+		offset += json_validate_string(json + offset, strlen(json + offset));
+
+		//skip to value separator
+		for(; json[offset] && json[offset] != ':'; offset++){
+		}
+
+		//skip whitespace
+		for(offset++; json[offset] && isspace(json[offset]); offset++){
+		}
+
+		if(match){
+			return offset;
+		}
+
+		//add length of value
+		offset += json_validate(json + offset, strlen(json + offset));
+
+		//skip trailing whitespace
+		for(; json[offset] && isspace(json[offset]); offset++){
+		}
+
+		if(json[offset] == ','){
+			offset++;
+			continue;
+		}
+
+		break;
+	}
+
+	return 0;
+}
+
+size_t json_array_offset(char* json, uint64_t key){
+	size_t offset = 0, index = 0;
+
+	//skip leading whitespace
+	for(offset = 0; json[offset] && isspace(json[offset]); offset++){
+	}
+
+	if(json[offset] != '['){
+		return 0;
+	}
+
+	for(offset++; index <= key; offset++){
+		//skip whitespace
+		for(; json[offset] && isspace(json[offset]); offset++){
+		}
+
+		if(index == key){
+			return offset;
+		}
+
+		offset += json_validate(json + offset, strlen(json + offset));
+
+		//skip trailing whitespace, find terminator
+		for(; json[offset] && isspace(json[offset]); offset++){
+		}
+
+		if(json[offset] != ','){
+			break;
+		}
+		index++;
+	}
+
+	return 0;
+}
+
+json_type json_obj(char* json, char* key){
+	size_t offset = json_obj_offset(json, key);
+	if(offset){
+		return json_identify(json + offset, strlen(json + offset));
+	}
+	return JSON_INVALID;
+}
+
+json_type json_array(char* json, uint64_t key){
+	size_t offset = json_array_offset(json, key);
+	if(offset){
+		return json_identify(json + offset, strlen(json + offset));
+	}
+	return JSON_INVALID;
+}
+
+uint8_t json_obj_bool(char* json, char* key, uint8_t fallback){
+	size_t offset = json_obj_offset(json, key);
+	if(offset){
+		if(!strncmp(json + offset, "true", 4)){
+			return 1;
+		}
+		if(!strncmp(json + offset, "false", 5)){
+			return 0;
+		}
+	}
+	return fallback;
+}
+
+uint8_t json_array_bool(char* json, uint64_t key, uint8_t fallback){
+	size_t offset = json_array_offset(json, key);
+	if(offset){
+		if(!strncmp(json + offset, "true", 4)){
+			return 1;
+		}
+		if(!strncmp(json + offset, "false", 5)){
+			return 0;
+		}
+	}
+	return fallback;
+}
+
+int64_t json_obj_int(char* json, char* key, int64_t fallback){
+	char* next_token = NULL;
+	int64_t result;
+	size_t offset = json_obj_offset(json, key);
+	if(offset){
+		result = strtol(json + offset, &next_token, 10);
+		if(next_token != json + offset){
+			return result;
+		}
+	}
+	return fallback;
+}
+
+double json_obj_double(char* json, char* key, double fallback){
+	char* next_token = NULL;
+	double result;
+	size_t offset = json_obj_offset(json, key);
+	if(offset){
+		result = strtod(json + offset, &next_token);
+		if(next_token != json + offset){
+			return result;
+		}
+	}
+	return fallback;
+}
+
+int64_t json_array_int(char* json, uint64_t key, int64_t fallback){
+	char* next_token = NULL;
+	int64_t result;
+	size_t offset = json_array_offset(json, key);
+	if(offset){
+		result = strtol(json + offset, &next_token, 10);
+		if(next_token != json + offset){
+			return result;
+		}
+	}
+	return fallback;
+}
+
+double json_array_double(char* json, uint64_t key, double fallback){
+	char* next_token = NULL;
+	double result;
+	size_t offset = json_array_offset(json, key);
+	if(offset){
+		result = strtod(json + offset, &next_token);
+		if(next_token != json + offset){
+			return result;
+		}
+	}
+	return fallback;
+}
+
+char* json_obj_str(char* json, char* key, size_t* length){
+	size_t offset = json_obj_offset(json, key), raw_length;
+	if(offset){
+		raw_length = json_validate_string(json + offset, strlen(json + offset));
+		if(length){
+			*length = raw_length - 2;
+		}
+		return json + offset + 1;
+	}
+	return NULL;
+}
+
+char* json_obj_strdup(char* json, char* key){
+	size_t len = 0;
+	char* value = json_obj_str(json, key, &len), *rv = NULL;
+	if(len){
+		rv = calloc(len + 1, sizeof(char));
+		if(rv){
+			memcpy(rv, value, len);
+		}
+	}
+	return rv;
+}
+
+char* json_array_str(char* json, uint64_t key, size_t* length){
+	size_t offset = json_array_offset(json, key), raw_length;
+	if(offset){
+		raw_length = json_validate_string(json + offset, strlen(json + offset));
+		if(length){
+			*length = raw_length - 2;
+		}
+		return json + offset + 1;
+	}
+	return NULL;
+}
+
+char* json_array_strdup(char* json, uint64_t key){
+	size_t len = 0;
+	char* value = json_array_str(json, key, &len), *rv = NULL;
+	if(len){
+		rv = calloc(len + 1, sizeof(char));
+		if(rv){
+			memcpy(rv, value, len);
+		}
+	}
+	return rv;
+}