Added C implementation (incomplete)

pixelnuke/net.c

@@ -0,0 +1,199 @@
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <fcntl.h>
+
+#include <event2/event.h>
+#include <event2/buffer.h>
+#include <event2/thread.h>
+#include <event2/bufferevent.h>
+
+#include <assert.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <err.h>
+
+#include "net.h"
+
+#define MAX_LINE 128
+
+typedef struct NetClient {
+	int sock_fd;
+	struct bufferevent *buf_ev;
+	int state;
+	void *user;
+} NetClient;
+
+#define NET_CSTATE_OPEN 0
+#define NET_CSTATE_CLOSING 1
+
+// global state
+static struct event_base *base;
+
+// User defined callbacks
+static net_on_connect netcb_on_connect = NULL;
+static net_on_read netcb_on_read = NULL;
+static net_on_close netcb_on_close = NULL;
+
+
+
+// libevent callbacks
+
+static void netev_on_read(struct bufferevent *bev, void *ctx) {
+	struct evbuffer *input;
+	char *line;
+	size_t n;
+	NetClient *client = ctx;
+
+	input = bufferevent_get_input(bev);
+
+	if ((line = evbuffer_readln(input, &n, EVBUFFER_EOL_LF))) {
+		if(netcb_on_read)
+			(*netcb_on_read)(client, line);
+		free(line);
+	}
+
+	if (evbuffer_get_length(input) >= MAX_LINE) {
+		net_err(client, "Line to long");
+	}
+}
+
+static void netev_on_write(struct bufferevent *bev, void *arg) {
+	NetClient *client = arg;
+
+	if (client->state == NET_CSTATE_CLOSING && evbuffer_get_length(bufferevent_get_output(bev)) == 0) {
+
+		if(netcb_on_close)
+			(*netcb_on_close)(client, 0);
+
+		bufferevent_free(bev);
+		free(client);
+	}
+}
+
+static void netev_on_error(struct bufferevent *bev, short error, void *arg) {
+	NetClient *client = arg;
+
+	// TODO: Some logging?
+	if (error & BEV_EVENT_EOF) {
+	} else if (error & BEV_EVENT_ERROR) {
+	} else if (error & BEV_EVENT_TIMEOUT) {
+	}
+
+	client->state = NET_CSTATE_CLOSING;
+	if(netcb_on_close)
+		(*netcb_on_close)(client, error);
+
+	bufferevent_free(bev);
+	free(client);
+}
+
+static void on_accept(evutil_socket_t listener, short event, void *arg) {
+	struct event_base *base = arg;
+	struct sockaddr_storage ss;
+	socklen_t slen = sizeof(ss);
+	int fd = accept(listener, (struct sockaddr*) &ss, &slen);
+	if (fd < 0) {
+		perror("accept failed");
+	} else if (fd > FD_SETSIZE) {
+		close(fd); // TODO: verify if this is needed. Only for select()? But libevent uses poll/kqueue?
+	} else {
+		NetClient *client = calloc(1, sizeof(NetClient));
+		if (client == NULL) {
+			perror("client malloc failed");
+			close(fd);
+			return;
+		}
+
+		client->sock_fd = fd;
+		client->buf_ev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);
+
+		evutil_make_socket_nonblocking(fd);
+		bufferevent_setcb(client->buf_ev, netev_on_read, netev_on_write, netev_on_error, client);
+		bufferevent_setwatermark(client->buf_ev, EV_READ, 0, MAX_LINE);
+
+		if(netcb_on_connect)
+			(*netcb_on_connect)(client);
+
+		if(client->state == NET_CSTATE_OPEN)
+			bufferevent_enable(client->buf_ev, EV_READ | EV_WRITE);
+	}
+}
+
+
+// Public functions
+
+void net_start(int port, net_on_connect on_connect, net_on_read on_read, net_on_close on_close) {
+	evutil_socket_t listener;
+	struct sockaddr_in sin;
+	struct event *listener_event;
+
+	evthread_use_pthreads();
+
+	//setvbuf(stdout, NULL, _IONBF, 0);
+
+	netcb_on_connect = on_connect;
+	netcb_on_read = on_read;
+	netcb_on_close = on_close;
+
+	base = event_base_new();
+	if (!base)
+		err(1, "Failed to create event_base");
+
+	evthread_make_base_notifiable(base);
+
+	sin.sin_family = AF_INET;
+	sin.sin_addr.s_addr = 0;
+	sin.sin_port = htons(1337);
+	listener = socket(AF_INET, SOCK_STREAM, 0);
+	evutil_make_socket_nonblocking(listener);
+
+	if (bind(listener, (struct sockaddr*) &sin, sizeof(sin)) < 0) {
+		err(1, "bind failed");
+	}
+
+	if (listen(listener, 16) < 0) {
+		err(1, "listen failed");
+	}
+
+	listener_event = event_new(base, listener, EV_READ | EV_PERSIST, on_accept, (void*) base);
+	event_add(listener_event, NULL);
+
+	event_base_dispatch(base);
+}
+
+
+void net_stop() {
+	event_base_loopbreak(base);
+}
+
+
+void net_send(NetClient *client, const char * msg) {
+	struct evbuffer *output = bufferevent_get_output(client->buf_ev);
+	evbuffer_add(output, msg, strlen(msg));
+	evbuffer_add(output, "\n", 1);
+}
+
+void net_close(NetClient *client) {
+	client->state = NET_CSTATE_CLOSING;
+	bufferevent_disable(client->buf_ev, EV_READ);
+}
+
+void net_err(NetClient *client, const char * msg) {
+	struct evbuffer *output = bufferevent_get_output(client->buf_ev);
+	evbuffer_add(output, "ERROR: ", 7);
+	evbuffer_add(output, msg, strlen(msg));
+	evbuffer_add(output, "\n", 1);
+	net_close(client);
+}
+
+void net_set_user(NetClient *client, void *user) {
+	client->user = user;
+}
+
+void net_get_user(NetClient *client, void **user) {
+	*user = client->user;
+}
+