Datastructures.c

/******************************************************************************
  Copyright (c) 2013 Morten Houmøller Nygaard - www.mortz.dk - admin@mortz.dk
 
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
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copies or substantial portions of the Software.

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SOFTWARE.
******************************************************************************/

#include "Datastructures.h"

/**
 * Creates a new list structure.
 *
 * @return type(ws_list) [Empty list]
 */
ws_list *list_new (void) {
	ws_list *l = (ws_list *) malloc(sizeof(ws_list));
	
	if (l != NULL) {
		l->len = 0;
		l->first = l->last = NULL;

		pthread_mutex_init(&l->lock, NULL);	
	} else {
		exit(EXIT_FAILURE);
	}

	return l;
}

/**
 * Frees the list structure, including all its nodes.
 * 
 * @param type(ws_list *) l [List containing clients]
 */
void list_free (ws_list *l) {
	ws_client *n, *p;
	ws_connection_close c = CLOSE_SHUTDOWN;
	pthread_mutex_lock(&l->lock);
	n = l->first;
	
	while (n != NULL) {
		p = n->next;

		ws_closeframe(n, c);
		shutdown(n->socket_id, SHUT_RDWR);

		client_free(n);

		close(n->socket_id);
		free(n);
		n = p;
	}

	l->first = l->last = NULL;
	pthread_mutex_unlock(&l->lock);	
	pthread_mutex_destroy(&l->lock);
	free(l);
}

/**
 * Adds a node to the list l.
 *
 * @param type(ws_list *) l [List containing clients]
 * @param type(ws_client *) n [Client]
 */
void list_add (ws_list *l, ws_client *n) {
	pthread_mutex_lock(&l->lock);
	
	if (l->first != NULL) {
		l->last = l->last->next = n;	
	} else {
		l->first = l->last = n;	
	}

	l->len++;
	
	pthread_mutex_unlock(&l->lock);
}

/**
 * Removes a node from the list, and sends closing frame to the client.
 *
 * @param type(ws_list) l [List containing clients]
 * @param type(ws_client) r [Client]
 */
void list_remove (ws_list *l, ws_client *r) {
	ws_client *n, *p;
	ws_connection_close c = CLOSE_SHUTDOWN;
	pthread_mutex_lock(&l->lock);
	n = l->first;

	if (n == NULL || r == NULL) {
		pthread_mutex_unlock(&l->lock);
		return;
	}

	do {
		if (n == r) {
			if (n == l->first) {
				l->first = n->next;
			} else {
				p->next = n->next;
			}

			if (n == l->last) {
				l->last = p;
			}

			ws_closeframe(n, c);
			shutdown(n->socket_id, SHUT_RDWR);

			client_free(n);

			close(n->socket_id);
			free(n);

			l->len--;
			break;
		}
		
		p = n;
		n = n->next;
	} while (n != NULL); 

	if (l->len == 0) {
		l->first = l->last = NULL;
	} else if (l->len == 1) {
		l->last = l->first;
	}

	pthread_mutex_unlock(&l->lock);
}

/**
 * Function that will send closeframe to each client in the list.
 *
 * @param type(ws_list) l [List containing clients.]
 */
void list_remove_all (ws_list *l) {
	ws_client *n;
	ws_connection_close c = CLOSE_POLICY;

	pthread_mutex_lock(&l->lock);
	n = l->first;

	if (n == NULL) {
		pthread_mutex_unlock(&l->lock);
		return;
	}

	do {
		ws_closeframe(n, c);
		n = n->next;
	} while (n != NULL); 

	pthread_mutex_unlock(&l->lock);
}

/**
 * Prints out information about each node contained in the list.
 * 
 * @param type(ws_list *) l [List containing clients]
 */
void list_print(ws_list *l) {
	ws_client *n;
	pthread_mutex_lock(&l->lock);
	n = l->first;

	if (n == NULL) {
		printf("No clients are online.\n\n");
		fflush(stdout);
		pthread_mutex_unlock(&l->lock);
		return;
	}

	do {
		printf("Socket Id: \t\t%d\n"
			   "Client IP: \t\t%s\n",
			   n->socket_id, n->client_ip);
		fflush(stdout);
		n = n->next;
	} while (n != NULL);
	pthread_mutex_unlock(&l->lock);
}

/**
 * Multicasts a message to all clients, but the one given as parameter in the 
 * list
 *
 * @param type(ws_list *) l [List containing clients]
 * @param type(ws_client *) n [Client]
 */
void list_multicast(ws_list *l, ws_client *n) {
	ws_client *p;
	pthread_mutex_lock(&l->lock);
	p = l->first;
	
	if (p == NULL) {
		pthread_mutex_unlock(&l->lock);
		return;
	}

	do {
		if (p != n) {
			ws_send(p, n->message); 
		}
		p = p->next;
	} while (p != NULL);
	pthread_mutex_unlock(&l->lock);
}

/**
 * Multicasts a message to one specific client.
 *
 * @param type(ws_list *) l [List containing clients]
 * @param type(ws_client *) n [Client] 
 * @param type(ws_message *) m [Message structure, that will be sent]
 */
void list_multicast_one(ws_list *l, ws_client *n, ws_message *m) {
	ws_client *p;
	pthread_mutex_lock(&l->lock);
	p = l->first;

	if (p == NULL || n == NULL) {
		pthread_mutex_unlock(&l->lock);
		return;
	}

	do {
		if (p == n) {
			ws_send(p, m);
			break;
		}
		p = p->next;
	} while (p != NULL);
	pthread_mutex_unlock(&l->lock);
}

/**
 * Multicasts message to all client in the list.
 *
 * @param type(ws_list *) l [List containing clients]
 * @param type(ws_message *) m [Message structure, that will be sent]
 */
void list_multicast_all(ws_list *l, ws_message *m) {
	ws_client *p;
	pthread_mutex_lock(&l->lock);
	p = l->first;

	if (p == NULL) {
		pthread_mutex_unlock(&l->lock);
		return;
	}

	do {
		ws_send(p, m);
		p = p->next;
	} while (p != NULL);
	pthread_mutex_unlock(&l->lock);
}

/**
 * Returns the client that has the equivalent information as given in the 
 * parameters, if it is in the list.
 *
 * @param type(ws_list *) l [List containing clients]
 * @param type(char *) addr [The ip-address of the client]
 * @param type(int) socket [The id of the socket belonging to the client]
 * @return type(ws_client *) [Client]
 */
ws_client *list_get(ws_list *l, char *addr, int socket) {
	ws_client *p;
	pthread_mutex_lock(&l->lock);
	p = l->first;
	
	if (p == NULL) {
		pthread_mutex_unlock(&l->lock);
		return p;
	}

	do {
		if (p->socket_id == socket && strcmp(addr, p->client_ip) == 0) {
			break;
		}
		p = p->next;
	} while (p != NULL);
	pthread_mutex_unlock(&l->lock);

	return p;
}

/**
 * Functions which creates the closeframe.
 *
 * @param type(ws_client *) n [Client]
 * @param type(ws_connection_close) s [The status of the closing]
 */
void ws_closeframe(ws_client *n, ws_connection_close s) {
	char frame[2];
	(void) s;

	if (n->headers->type == RFC6455 || n->headers->type == HYBI10 || 
			n->headers->type == HYBI07) {
		frame[0] = '\x88';
		frame[1] = '\x00';
		/**
		 * TODO: 
		 * 		- Use ws_connection_close
		 */ 
		send(n->socket_id, frame, 2, 0);
	} else if (n->headers->type == HYBI00) {
		frame[0] = '\xFF';
		frame[1] = '\x00';
		send(n->socket_id, frame, 2, 0);
		pthread_cancel(n->thread_id);
	}
}

/**
 * Function which do the actual sending of messages.
 *
 * @param type(ws_client *) n [Client] 
 * @param type(ws_message *) m [Message structure, that will be sent]
 */
void ws_send(ws_client *n, ws_message *m) {
	if ( n->headers->type == HYBI00 ) {
		/**
		 * Adds 2 to the length of the message, as we have to put '\x00' and
		 * '\xFF' in the front and end of the message.
		 */
		send(n->socket_id, m->hybi00, m->len+2, 0);
	} else if ( n->headers->type == HIXIE75 ) {
		
	} else if ( n->headers->type == HYBI07 || n->headers->type == RFC6455 
			|| n->headers->type == HYBI10) {
		send(n->socket_id, m->enc, m->enc_len, 0);
	}
}

/**
 * Creates a new client.
 *
 * @param type(int) sock [The id of the clients socket]
 * @param type(char *) addr [The ip-address of the client]
 * @param type(ws_client *)
 */
ws_client *client_new (int sock, char *addr) {
	ws_client *n = (ws_client *) malloc(sizeof(ws_client));

	if (n != NULL) {
		n->socket_id = sock;
		n->thread_id = 0;
		n->client_ip = addr;
		n->string = NULL;
		n->headers = NULL;
		n->next = NULL;
		n->message = NULL;
	}

	return n;
}

/**
 * Creates a new header structure.
 *
 * @return type(ws_header *) [Header structure]
 */
ws_header *header_new () {
	ws_header *h = (ws_header *) malloc(sizeof(ws_header));

	if (h != NULL) {
		h->host = NULL;
		h->connection = NULL;
		h->key = NULL;
		h->key1 = NULL;
		h->key2 = NULL;
		h->key3 = NULL;
		h->type = UNKNOWN;
		h->protocol = NONE;
		h->origin = NULL;
		h->upgrade = NULL;
		h->get = NULL;
		h->accept = NULL;
		h->extension = NULL;
		h->resourcename = NULL;
		h->protocol_string = NULL;
		h->version = 0;
		h->host_len = 0;
		h->protocol_len = 0;
		h->origin_len = 0;
		h->upgrade_len = 0;
		h->accept_len = 0;
		h->extension_len = 0;
		h->get_len = 0;
		h->resourcename_len = 0;
	}

	return h;
}

/**
 * Creates a new message structure.
 *
 * @return type(ws_message *) [Message structure]
 */
ws_message *message_new() {
	ws_message *m = (ws_message *) malloc(sizeof(ws_message));

	if (m != NULL) {
		memset(m->opcode, '\0', 1);
		memset(m->mask, '\0', 4);
		m->len = 0; 
		m->enc_len = 0;
		m->next_len = 0;
		m->msg = NULL;
		m->next = NULL;
		m->enc = NULL;
		m->hybi00 = NULL;
	}

	return m;	
}

/**
 * Frees all allocations in the header structure.
 *
 * @param type(ws_header *) h [Header structure]
 */
void header_free(ws_header *h) {
	if (h->accept != NULL) {
		free(h->accept);
		h->accept = NULL;
	}

	if (h->resourcename != NULL) {
		free(h->resourcename);
		h->resourcename = NULL;
	}

	if (h->protocol_string != NULL) {
		free(h->protocol_string);
		h->protocol_string = NULL;
	}
}

/**
 * Frees all allocations in the message structure.
 *
 * @param type(ws_message *) m [Message structure]
 */
void message_free(ws_message *m) {
	if (m->msg != NULL) {
		free(m->msg);
		m->msg = NULL;
	}
	
	if (m->enc != NULL) {
		free(m->enc);
		m->enc = NULL;
	}

	if (m->next != NULL) {
		free(m->next);
		m->next = NULL;
	}

	if (m->hybi00 != NULL) {
		free(m->hybi00);
		m->hybi00 = NULL;
	}
}

/**
 * Frees all allocations in the node, including the header and message 
 * structure.
 *
 * @param type(ws_client*) n [Client]
 */
void client_free(ws_client *n) {
	if (n->client_ip != NULL) {
		free(n->client_ip);
		n->client_ip = NULL;
	}

	if (n->string != NULL) {
		free(n->string);
		n->string = NULL;
	}

	if (n->headers != NULL) {
		header_free(n->headers);
		free(n->headers);
		n->headers = NULL;
	}

	if (n->message != NULL) {
		message_free(n->message);
		free(n->message);
		n->message = NULL;
	}
}