splitted netdata to multiple source files

1 files changed, 1247 insertions, 0 deletions

diff --git a/src/web_server.c b/src/web_server.c
new file mode 100755
index 0000000000..c7c4b3ec20
--- /dev/null
+++ b/src/web_server.c
@@ -0,0 +1,1247 @@
+// enable strcasestr()
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <errno.h>
+#include <pthread.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <netinet/tcp.h>
+
+#include "common.h"
+#include "log.h"
+#include "config.h"
+#include "url.h"
+#include "web_buffer.h"
+#include "web_client.h"
+#include "web_server.h"
+#include "global_statistics.h"
+#include "rrd.h"
+#include "rrd2json.h"
+
+int listen_fd = -1;
+int listen_port = LISTEN_PORT;
+
+int create_listen_socket(int port)
+{
+		int sock=-1;
+		int sockopt=1;
+		struct sockaddr_in name;
+
+		debug(D_LISTENER, "Creating new listening socket on port %d", port);
+
+		sock = socket(AF_INET, SOCK_STREAM, 0);
+		if (sock < 0)
+				fatal("socket() failed, errno=%d", errno);
+
+		/* avoid "address already in use" */
+		setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void*)&sockopt, sizeof(sockopt));
+
+		memset(&name, 0, sizeof(struct sockaddr_in));
+		name.sin_family = AF_INET;
+		name.sin_port = htons (port);
+		name.sin_addr.s_addr = htonl (INADDR_ANY);
+		if (bind (sock, (struct sockaddr *) &name, sizeof (name)) < 0)
+			fatal("bind() failed, errno=%d", errno);
+
+		if (listen(sock, LISTEN_BACKLOG) < 0)
+			fatal("listen() failed, errno=%d", errno);
+
+		debug(D_LISTENER, "Listening Port %d created", port);
+		return sock;
+}
+
+
+int mysendfile(struct web_client *w, char *filename)
+{
+	static char *web_dir = NULL;
+	if(!web_dir) web_dir = config_get("global", "web files directory", "web");
+
+	debug(D_WEB_CLIENT, "%llu: Looking for file '%s'...", w->id, filename);
+
+	// skip leading slashes
+	while (*filename == '/') filename++;
+
+	// if the filename contain known paths, skip them
+		 if(strncmp(filename, WEB_PATH_DATA       "/", strlen(WEB_PATH_DATA)       + 1) == 0) filename = &filename[strlen(WEB_PATH_DATA)       + 1];
+	else if(strncmp(filename, WEB_PATH_DATASOURCE "/", strlen(WEB_PATH_DATASOURCE) + 1) == 0) filename = &filename[strlen(WEB_PATH_DATASOURCE) + 1];
+	else if(strncmp(filename, WEB_PATH_GRAPH      "/", strlen(WEB_PATH_GRAPH)      + 1) == 0) filename = &filename[strlen(WEB_PATH_GRAPH)      + 1];
+	else if(strncmp(filename, WEB_PATH_FILE       "/", strlen(WEB_PATH_FILE)       + 1) == 0) filename = &filename[strlen(WEB_PATH_FILE)       + 1];
+
+	// if the filename contains a / or a .., refuse to serve it
+	if(strchr(filename, '/') != 0 || strstr(filename, "..") != 0) {
+		debug(D_WEB_CLIENT_ACCESS, "%llu: File '%s' is not acceptable.", w->id, filename);
+		web_buffer_printf(w->data, "File '%s' cannot be served. Filenames cannot contain / or ..", filename);
+		return 400;
+	}
+
+	// access the file
+	char webfilename[FILENAME_MAX + 1];
+	snprintf(webfilename, FILENAME_MAX, "%s/%s", web_dir, filename);
+
+	// check if the file exists
+	struct stat stat;
+	if(lstat(webfilename, &stat) != 0) {
+		error("%llu: File '%s' is not found.", w->id, webfilename);
+		web_buffer_printf(w->data, "File '%s' does not exist, or is not accessible.", filename);
+		return 404;
+	}
+
+	// check if the file is owned by us
+	if(stat.st_uid != getuid() && stat.st_uid != geteuid()) {
+		error("%llu: File '%s' is owned by user %d (I run as user %d). Access Denied.", w->id, webfilename, stat.st_uid, getuid());
+		web_buffer_printf(w->data, "Access to file '%s' is not permitted.", filename);
+		return 403;
+	}
+
+	// open the file
+	w->ifd = open(webfilename, O_NONBLOCK, O_RDONLY);
+	if(w->ifd == -1) {
+		w->ifd = w->ofd;
+
+		if(errno == EBUSY || errno == EAGAIN) {
+			error("%llu: File '%s' is busy, sending 307 Moved Temporarily to force retry.", w->id, webfilename);
+			snprintf(w->response_header, MAX_HTTP_HEADER_SIZE, "Location: /" WEB_PATH_FILE "/%s\r\n", filename);
+			web_buffer_printf(w->data, "The file '%s' is currently busy. Please try again later.", filename);
+			return 307;
+		}
+		else {
+			error("%llu: Cannot open file '%s'.", w->id, webfilename);
+			web_buffer_printf(w->data, "Cannot open file '%s'.", filename);
+			return 404;
+		}
+	}
+	
+	// pick a Content-Type for the file
+		 if(strstr(filename, ".html") != NULL)	w->data->contenttype = CT_TEXT_HTML;
+	else if(strstr(filename, ".js")   != NULL)	w->data->contenttype = CT_APPLICATION_X_JAVASCRIPT;
+	else if(strstr(filename, ".css")  != NULL)	w->data->contenttype = CT_TEXT_CSS;
+	else if(strstr(filename, ".xml")  != NULL)	w->data->contenttype = CT_TEXT_XML;
+	else if(strstr(filename, ".xsl")  != NULL)	w->data->contenttype = CT_TEXT_XSL;
+	else if(strstr(filename, ".txt")  != NULL)  w->data->contenttype = CT_TEXT_PLAIN;
+	else if(strstr(filename, ".svg")  != NULL)  w->data->contenttype = CT_IMAGE_SVG_XML;
+	else if(strstr(filename, ".ttf")  != NULL)  w->data->contenttype = CT_APPLICATION_X_FONT_TRUETYPE;
+	else if(strstr(filename, ".otf")  != NULL)  w->data->contenttype = CT_APPLICATION_X_FONT_OPENTYPE;
+	else if(strstr(filename, ".woff") != NULL)  w->data->contenttype = CT_APPLICATION_FONT_WOFF;
+	else if(strstr(filename, ".eot")  != NULL)  w->data->contenttype = CT_APPLICATION_VND_MS_FONTOBJ;
+	else w->data->contenttype = CT_APPLICATION_OCTET_STREAM;
+
+	debug(D_WEB_CLIENT_ACCESS, "%llu: Sending file '%s' (%ld bytes, ifd %d, ofd %d).", w->id, webfilename, stat.st_size, w->ifd, w->ofd);
+
+	w->mode = WEB_CLIENT_MODE_FILECOPY;
+	w->wait_receive = 1;
+	w->wait_send = 0;
+	w->data->bytes = 0;
+	w->data->buffer[0] = '\0';
+	w->data->rbytes = stat.st_size;
+	w->data->date = stat.st_mtim.tv_sec;
+
+	return 200;
+}
+
+void web_client_reset(struct web_client *w)
+{
+	struct timeval tv;
+	gettimeofday(&tv, NULL);
+
+	long sent = w->zoutput?(long)w->zstream.total_out:((w->mode == WEB_CLIENT_MODE_FILECOPY)?w->data->rbytes:w->data->bytes);
+	long size = (w->mode == WEB_CLIENT_MODE_FILECOPY)?w->data->rbytes:w->data->bytes;
+	
+	if(w->last_url[0]) log_access("%llu: (sent/all = %ld/%ld bytes %0.0f%%, prep/sent/total = %0.2f/%0.2f/%0.2f ms) %s: '%s'",
+		w->id,
+		sent, size, -((size>0)?((float)(size-sent)/(float)size * 100.0):0.0),
+		(float)usecdiff(&w->tv_ready, &w->tv_in) / 1000.0,
+		(float)usecdiff(&tv, &w->tv_ready) / 1000.0,
+		(float)usecdiff(&tv, &w->tv_in) / 1000.0,
+		(w->mode == WEB_CLIENT_MODE_FILECOPY)?"filecopy":"data",
+		w->last_url
+		);
+
+	debug(D_WEB_CLIENT, "%llu: Reseting client.", w->id);
+
+	if(w->mode == WEB_CLIENT_MODE_FILECOPY) {
+		debug(D_WEB_CLIENT, "%llu: Closing filecopy input file.", w->id);
+		close(w->ifd);
+		w->ifd = w->ofd;
+	}
+
+	w->last_url[0] = '\0';
+
+	w->data->contenttype = CT_TEXT_PLAIN;
+	w->mode = WEB_CLIENT_MODE_NORMAL;
+
+	w->data->rbytes = 0;
+	w->data->bytes = 0;
+	w->data->sent = 0;
+
+	w->response_header[0] = '\0';
+	w->data->buffer[0] = '\0';
+
+	w->wait_receive = 1;
+	w->wait_send = 0;
+
+	// if we had enabled compression, release it
+	if(w->zinitialized) {
+		debug(D_DEFLATE, "%llu: Reseting compression.", w->id);
+		deflateEnd(&w->zstream);
+		w->zoutput = 0;
+		w->zsent = 0;
+		w->zhave = 0;
+		w->zstream.avail_in = 0;
+		w->zstream.avail_out = 0;
+		w->zstream.total_in = 0;
+		w->zstream.total_out = 0;
+		w->zinitialized = 0;
+	}
+}
+
+void web_client_enable_deflate(struct web_client *w) {
+	if(w->zinitialized == 1) {
+		error("%llu: Compression has already be initialized for this client.", w->id);
+		return;
+	}
+
+	if(w->data->sent) {
+		error("%llu: Cannot enable compression in the middle of a conversation.", w->id);
+		return;
+	}
+
+	w->zstream.zalloc = Z_NULL;
+	w->zstream.zfree = Z_NULL;
+	w->zstream.opaque = Z_NULL;
+
+	w->zstream.next_in = (Bytef *)w->data->buffer;
+	w->zstream.avail_in = 0;
+	w->zstream.total_in = 0;
+
+	w->zstream.next_out = w->zbuffer;
+	w->zstream.avail_out = 0;
+	w->zstream.total_out = 0;
+
+	w->zstream.zalloc = Z_NULL;
+	w->zstream.zfree = Z_NULL;
+	w->zstream.opaque = Z_NULL;
+
+//	if(deflateInit(&w->zstream, Z_DEFAULT_COMPRESSION) != Z_OK) {
+//		error("%llu: Failed to initialize zlib. Proceeding without compression.", w->id);
+//		return;
+//	}
+
+	// Select GZIP compression: windowbits = 15 + 16 = 31
+	if(deflateInit2(&w->zstream, Z_DEFAULT_COMPRESSION, Z_DEFLATED, 31, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
+		error("%llu: Failed to initialize zlib. Proceeding without compression.", w->id);
+		return;
+	}
+
+	w->zsent = 0;
+	w->zoutput = 1;
+	w->zinitialized = 1;
+
+	debug(D_DEFLATE, "%llu: Initialized compression.", w->id);
+}
+
+int web_client_data_request(struct web_client *w, char *url, int datasource_type)
+{
+	char *args = strchr(url, '?');
+	if(args) {
+		*args='\0';
+		args = &args[1];
+	}
+
+	// get the name of the data to show
+	char *tok = mystrsep(&url, "/");
+	debug(D_WEB_CLIENT, "%llu: Searching for RRD data with name '%s'.", w->id, tok);
+
+	// do we have such a data set?
+	RRD_STATS *st = rrd_stats_find_byname(tok);
+	if(!st) st = rrd_stats_find(tok);
+	if(!st) {
+		// we don't have it
+		// try to send a file with that name
+		w->data->bytes = 0;
+		return(mysendfile(w, tok));
+	}
+
+	// we have it
+	debug(D_WEB_CLIENT, "%llu: Found RRD data with name '%s'.", w->id, tok);
+
+	// how many entries does the client want?
+	long lines = save_history;
+	long group_count = 1;
+	time_t after = 0, before = 0;
+	int group_method = GROUP_AVERAGE;
+	int nonzero = 0;
+
+	if(url) {
+		// parse the lines required
+		tok = mystrsep(&url, "/");
+		if(tok) lines = atoi(tok);
+		if(lines < 1) lines = 1;
+	}
+	if(url) {
+		// parse the group count required
+		tok = mystrsep(&url, "/");
+		if(tok) group_count = atoi(tok);
+		if(group_count < 1) group_count = 1;
+		//if(group_count > save_history / 20) group_count = save_history / 20;
+	}
+	if(url) {
+		// parse the grouping method required
+		tok = mystrsep(&url, "/");
+		if(strcmp(tok, "max") == 0) group_method = GROUP_MAX;
+		else if(strcmp(tok, "average") == 0) group_method = GROUP_AVERAGE;
+		else if(strcmp(tok, "sum") == 0) group_method = GROUP_SUM;
+		else debug(D_WEB_CLIENT, "%llu: Unknown group method '%s'", w->id, tok);
+	}
+	if(url) {
+		// parse after time
+		tok = mystrsep(&url, "/");
+		if(tok) after = strtoul(tok, NULL, 10);
+		if(after < 0) after = 0;
+	}
+	if(url) {
+		// parse before time
+		tok = mystrsep(&url, "/");
+		if(tok) before = strtoul(tok, NULL, 10);
+		if(before < 0) before = 0;
+	}
+	if(url) {
+		// parse nonzero
+		tok = mystrsep(&url, "/");
+		if(tok && strcmp(tok, "nonzero") == 0) nonzero = 1;
+	}
+
+	w->data->contenttype = CT_APPLICATION_JSON;
+	w->data->bytes = 0;
+
+	char *google_version = "0.6";
+	char *google_reqId = "0";
+	char *google_sig = "0";
+	char *google_out = "json";
+	char *google_responseHandler = "google.visualization.Query.setResponse";
+	char *google_outFileName = NULL;
+	unsigned long last_timestamp_in_data = 0;
+	if(datasource_type == DATASOURCE_GOOGLE_JSON || datasource_type == DATASOURCE_GOOGLE_JSONP) {
+
+		w->data->contenttype = CT_APPLICATION_X_JAVASCRIPT;
+
+		while(args) {
+			tok = mystrsep(&args, "&");
+			if(tok) {
+				char *name = mystrsep(&tok, "=");
+				if(name && strcmp(name, "tqx") == 0) {
+					char *key = mystrsep(&tok, ":");
+					char *value = mystrsep(&tok, ";");
+					if(key && value && *key && *value) {
+						if(strcmp(key, "version") == 0)
+							google_version = value;
+
+						else if(strcmp(key, "reqId") == 0)
+							google_reqId = value;
+
+						else if(strcmp(key, "sig") == 0)
+							google_sig = value;
+						
+						else if(strcmp(key, "out") == 0)
+							google_out = value;
+						
+						else if(strcmp(key, "responseHandler") == 0)
+							google_responseHandler = value;
+						
+						else if(strcmp(key, "outFileName") == 0)
+							google_outFileName = value;
+					}
+				}
+			}
+		}
+
+		debug(D_WEB_CLIENT_ACCESS, "%llu: GOOGLE JSONP: version = '%s', reqId = '%s', sig = '%s', out = '%s', responseHandler = '%s', outFileName = '%s'",
+			w->id, google_version, google_reqId, google_sig, google_out, google_responseHandler, google_outFileName
+			);
+
+		if(datasource_type == DATASOURCE_GOOGLE_JSONP) {
+			last_timestamp_in_data = strtoul(google_sig, NULL, 0);
+
+			// check the client wants json
+			if(strcmp(google_out, "json") != 0) {
+				w->data->bytes = snprintf(w->data->buffer, w->data->size, 
+					"%s({version:'%s',reqId:'%s',status:'error',errors:[{reason:'invalid_query',message:'output format is not supported',detailed_message:'the format %s requested is not supported by netdata.'}]});",
+					google_responseHandler, google_version, google_reqId, google_out);
+					return 200;
+			}
+		}
+	}
+
+	if(datasource_type == DATASOURCE_GOOGLE_JSONP) {
+		w->data->bytes = snprintf(w->data->buffer, w->data->size, 
+			"%s({version:'%s',reqId:'%s',status:'ok',sig:'%lu',table:",
+			google_responseHandler, google_version, google_reqId, st->last_updated.tv_sec);
+	}
+	
+	debug(D_WEB_CLIENT_ACCESS, "%llu: Sending RRD data '%s' (id %s, %d lines, %d group, %d group_method, %lu after, %lu before).", w->id, st->name, st->id, lines, group_count, group_method, after, before);
+	unsigned long timestamp_in_data = rrd_stats_json(datasource_type, st, w->data, lines, group_count, group_method, after, before, nonzero);
+
+	if(datasource_type == DATASOURCE_GOOGLE_JSONP) {
+		if(timestamp_in_data > last_timestamp_in_data)
+			w->data->bytes += snprintf(&w->data->buffer[w->data->bytes], w->data->size - w->data->bytes, "});");
+
+		else {
+			// the client already has the latest data
+			w->data->bytes = snprintf(w->data->buffer, w->data->size, 
+				"%s({version:'%s',reqId:'%s',status:'error',errors:[{reason:'not_modified',message:'Data not modified'}]});",
+				google_responseHandler, google_version, google_reqId);
+		}
+	}
+
+	return 200;
+}
+
+void web_client_process(struct web_client *w)
+{
+	int code = 500;
+	int bytes;
+
+	w->wait_receive = 0;
+
+	// check if we have an empty line (end of HTTP header)
+	if(strstr(w->data->buffer, "\r\n\r\n")) {
+		global_statistics_lock();
+		global_statistics.web_requests++;
+		global_statistics_unlock();
+
+		gettimeofday(&w->tv_in, NULL);
+		debug(D_WEB_DATA, "%llu: Processing data buffer of %d bytes: '%s'.", w->id, w->data->bytes, w->data->buffer);
+
+		// check if the client requested keep-alive HTTP
+		if(strcasestr(w->data->buffer, "Connection: keep-alive")) w->keepalive = 1;
+		else w->keepalive = 0;
+
+		// check if the client accepts deflate
+		if(strstr(w->data->buffer, "gzip"))
+			web_client_enable_deflate(w);
+
+		int datasource_type = DATASOURCE_GOOGLE_JSONP;
+		//if(strstr(w->data->buffer, "X-DataSource-Auth"))
+		//	datasource_type = DATASOURCE_GOOGLE_JSON;
+
+		char *buf = w->data->buffer;
+		char *tok = strsep(&buf, " \r\n");
+		char *url = NULL;
+		char *pointer_to_free = NULL; // keep url_decode() allocated buffer
+
+		if(buf && strcmp(tok, "GET") == 0) {
+			tok = strsep(&buf, " \r\n");
+			pointer_to_free = url = url_decode(tok);
+			debug(D_WEB_CLIENT, "%llu: Processing HTTP GET on url '%s'.", w->id, url);
+		}
+		else if (buf && strcmp(tok, "POST") == 0) {
+			w->keepalive = 0;
+			tok = strsep(&buf, " \r\n");
+			pointer_to_free = url = url_decode(tok);
+
+			debug(D_WEB_CLIENT, "%llu: I don't know how to handle POST with form data. Assuming it is a GET on url '%s'.", w->id, url);
+		}
+
+		w->last_url[0] = '\0';
+		if(url) {
+			strncpy(w->last_url, url, URL_MAX);
+			w->last_url[URL_MAX] = '\0';
+
+			tok = mystrsep(&url, "/?&");
+
+			debug(D_WEB_CLIENT, "%llu: Processing command '%s'.", w->id, tok);
+
+			if(strcmp(tok, WEB_PATH_DATA) == 0) { // "data"
+				// the client is requesting rrd data
+				datasource_type = DATASOURCE_JSON;
+				code = web_client_data_request(w, url, datasource_type);
+			}
+			else if(strcmp(tok, WEB_PATH_DATASOURCE) == 0) { // "datasource"
+				// the client is requesting google datasource
+				code = web_client_data_request(w, url, datasource_type);
+			}
+			else if(strcmp(tok, WEB_PATH_GRAPH) == 0) { // "graph"
+				// the client is requesting an rrd graph
+
+				// get the name of the data to show
+				tok = mystrsep(&url, "/?&");
+				debug(D_WEB_CLIENT, "%llu: Searching for RRD data with name '%s'.", w->id, tok);
+
+				// do we have such a data set?
+				RRD_STATS *st = rrd_stats_find_byname(tok);
+				if(!st) {
+					// we don't have it
+					// try to send a file with that name
+					w->data->bytes = 0;
+					code = mysendfile(w, tok);
+				}
+				else {
+					code = 200;
+					debug(D_WEB_CLIENT_ACCESS, "%llu: Sending %s.json of RRD_STATS...", w->id, st->name);
+					w->data->contenttype = CT_APPLICATION_JSON;
+					w->data->bytes = 0;
+					rrd_stats_graph_json(st, url, w->data);
+				}
+			}
+			else if(strcmp(tok, "debug") == 0) {
+				w->data->bytes = 0;
+
+				// get the name of the data to show
+				tok = mystrsep(&url, "/?&");
+				debug(D_WEB_CLIENT, "%llu: Searching for RRD data with name '%s'.", w->id, tok);
+
+				// do we have such a data set?
+				RRD_STATS *st = rrd_stats_find_byname(tok);
+				if(!st) {
+					code = 404;
+					web_buffer_printf(w->data, "Chart %s is not found.\r\n", tok);
+					debug(D_WEB_CLIENT_ACCESS, "%llu: %s is not found.", w->id, tok);
+				}
+				else {
+					code = 200;
+					debug_flags |= D_RRD_STATS;
+					st->debug = st->debug?0:1;
+					web_buffer_printf(w->data, "Chart %s has now debug %s.\r\n", tok, st->debug?"enabled":"disabled");
+					debug(D_WEB_CLIENT_ACCESS, "%llu: debug for %s is %s.", w->id, tok, st->debug?"enabled":"disabled");
+				}
+			}
+			else if(strcmp(tok, "mirror") == 0) {
+				code = 200;
+
+				debug(D_WEB_CLIENT_ACCESS, "%llu: Mirroring...", w->id);
+
+				// replace the zero bytes with spaces
+				int i;
+				for(i = 0; i < w->data->size; i++)
+					if(w->data->buffer[i] == '\0') w->data->buffer[i] = ' ';
+
+				// just leave the buffer as is
+				// it will be copied back to the client
+			}
+			else if(strcmp(tok, "list") == 0) {
+				code = 200;
+
+				debug(D_WEB_CLIENT_ACCESS, "%llu: Sending list of RRD_STATS...", w->id);
+
+				w->data->bytes = 0;
+				RRD_STATS *st = root;
+
+				for ( ; st ; st = st->next )
+					web_buffer_printf(w->data, "%s\n", st->name);
+			}
+			else if(strcmp(tok, "all.json") == 0) {
+				code = 200;
+				debug(D_WEB_CLIENT_ACCESS, "%llu: Sending JSON list of all monitors of RRD_STATS...", w->id);
+
+				w->data->contenttype = CT_APPLICATION_JSON;
+				w->data->bytes = 0;
+				rrd_stats_all_json(w->data);
+			}
+			else if(strcmp(tok, "netdata.conf") == 0) {
+				code = 200;
+				debug(D_WEB_CLIENT_ACCESS, "%llu: Sending netdata.conf ...", w->id);
+
+				w->data->contenttype = CT_TEXT_PLAIN;
+				w->data->bytes = 0;
+				generate_config(w->data, 0);
+			}
+			else if(strcmp(tok, WEB_PATH_FILE) == 0) { // "file"
+				tok = mystrsep(&url, "/?&");
+				if(tok && *tok) code = mysendfile(w, tok);
+				else {
+					code = 400;
+					w->data->bytes = 0;
+					strcpy(w->data->buffer, "You have to give a filename to get.\r\n");
+					w->data->bytes = strlen(w->data->buffer);
+				}
+			}
+			else if(!tok[0]) {
+				w->data->bytes = 0;
+				code = mysendfile(w, "index.html");
+			}
+			else {
+				w->data->bytes = 0;
+				code = mysendfile(w, tok);
+			}
+
+		}
+		else {
+			strcpy(w->last_url, "not a valid response");
+
+			if(buf) debug(D_WEB_CLIENT_ACCESS, "%llu: Cannot understand '%s'.", w->id, buf);
+
+			code = 500;
+			w->data->bytes = 0;
+			strcpy(w->data->buffer, "I don't understand you...\r\n");
+			w->data->bytes = strlen(w->data->buffer);
+		}
+		
+		// free url_decode() buffer
+		if(pointer_to_free) free(pointer_to_free);
+	}
+	else if(w->data->bytes > 8192) {
+		strcpy(w->last_url, "too big request");
+
+		debug(D_WEB_CLIENT_ACCESS, "%llu: Received request is too big.", w->id);
+
+		code = 400;
+		w->data->bytes = 0;
+		strcpy(w->data->buffer, "Received request is too big.\r\n");
+		w->data->bytes = strlen(w->data->buffer);
+	}
+	else {
+		// wait for more data
+		w->wait_receive = 1;
+		return;
+	}
+
+	if(w->data->bytes > w->data->size) {
+		error("%llu: memory overflow encountered (size is %ld, written %ld).", w->data->size, w->data->bytes);
+	}
+
+	gettimeofday(&w->tv_ready, NULL);
+	w->data->date = time(NULL);
+	w->data->sent = 0;
+
+	// prepare the HTTP response header
+	debug(D_WEB_CLIENT, "%llu: Generating HTTP header with response %d.", w->id, code);
+
+	char *content_type_string = "";
+	switch(w->data->contenttype) {
+		case CT_TEXT_HTML:
+			content_type_string = "text/html";
+			break;
+
+		case CT_APPLICATION_XML:
+			content_type_string = "application/xml";
+			break;
+
+		case CT_APPLICATION_JSON:
+			content_type_string = "application/json";
+			break;
+
+		case CT_APPLICATION_X_JAVASCRIPT:
+			content_type_string = "application/x-javascript";
+			break;
+
+		case CT_TEXT_CSS:
+			content_type_string = "text/css";
+			break;
+
+		case CT_TEXT_XML:
+			content_type_string = "text/xml";
+			break;
+
+		case CT_TEXT_XSL:
+			content_type_string = "text/xsl";
+			break;
+
+		case CT_APPLICATION_OCTET_STREAM:
+			content_type_string = "application/octet-stream";
+			break;
+
+		case CT_IMAGE_SVG_XML:
+			content_type_string = "image/svg+xml";
+			break;
+
+		case CT_APPLICATION_X_FONT_TRUETYPE:
+			content_type_string = "application/x-font-truetype";
+			break;
+
+		case CT_APPLICATION_X_FONT_OPENTYPE:
+			content_type_string = "application/x-font-opentype";
+			break;
+
+		case CT_APPLICATION_FONT_WOFF:
+			content_type_string = "application/font-woff";
+			break;
+
+		case CT_APPLICATION_VND_MS_FONTOBJ:
+			content_type_string = "application/vnd.ms-fontobject";
+			break;
+
+		default:
+		case CT_TEXT_PLAIN:
+			content_type_string = "text/plain";
+			break;
+	}
+
+	char *code_msg = "";
+	switch(code) {
+		case 200:
+			code_msg = "OK";
+			break;
+
+		case 307:
+			code_msg = "Temporary Redirect";
+			break;
+
+		case 400:
+			code_msg = "Bad Request";
+			break;
+
+		case 403:
+			code_msg = "Forbidden";
+			break;
+
+		case 404:
+			code_msg = "Not Found";
+			break;
+
+		default:
+			code_msg = "Internal Server Error";
+			break;
+	}
+
+	char date[100];
+	struct tm tm = *gmtime(&w->data->date);
+	strftime(date, sizeof(date), "%a, %d %b %Y %H:%M:%S %Z", &tm);
+
+	char custom_header[MAX_HTTP_HEADER_SIZE + 1] = "";
+	if(w->response_header[0]) 
+		strcpy(custom_header, w->response_header);
+
+	int headerlen = 0;
+	headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
+		"HTTP/1.1 %d %s\r\n"
+		"Connection: %s\r\n"
+		"Server: NetData Embedded HTTP Server\r\n"
+		"Content-Type: %s\r\n"
+		"Access-Control-Allow-Origin: *\r\n"
+		"Date: %s\r\n"
+		, code, code_msg
+		, w->keepalive?"keep-alive":"close"
+		, content_type_string
+		, date
+		);
+
+	if(custom_header[0])
+		headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen, "%s", custom_header);
+
+	if(w->mode == WEB_CLIENT_MODE_NORMAL) {
+		headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
+			"Expires: %s\r\n"
+			"Cache-Control: no-cache\r\n"
+			, date
+			);
+	}
+	else {
+		headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
+			"Cache-Control: public\r\n"
+			);
+	}
+
+	// if we know the content length, put it
+	if(!w->zoutput && (w->data->bytes || w->data->rbytes))
+		headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
+			"Content-Length: %ld\r\n"
+			, w->data->bytes?w->data->bytes:w->data->rbytes
+			);
+	else if(!w->zoutput)
+		w->keepalive = 0;	// content-length is required for keep-alive
+
+	if(w->zoutput) {
+		headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen,
+			"Content-Encoding: gzip\r\n"
+			"Transfer-Encoding: chunked\r\n"
+			);
+	}
+
+	headerlen += snprintf(&w->response_header[headerlen], MAX_HTTP_HEADER_SIZE - headerlen, "\r\n");
+
+	// disable TCP_NODELAY, to buffer the header
+	int flag = 0;
+	if(setsockopt(w->ofd, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int)) != 0) error("%llu: failed to disable TCP_NODELAY on socket.", w->id);
+
+	// sent the HTTP header
+	debug(D_WEB_DATA, "%llu: Sending response HTTP header of size %d: '%s'", w->id, headerlen, w->response_header);
+
+	bytes = send(w->ofd, w->response_header, headerlen, 0);
+	if(bytes != headerlen)
+		error("%llu: HTTP Header failed to be sent (I sent %d bytes but the system sent %d bytes).", w->id, headerlen, bytes);
+	else {
+		global_statistics_lock();
+		global_statistics.bytes_sent += bytes;
+		global_statistics_unlock();
+	}
+
+	// enable TCP_NODELAY, to send all data immediately at the next send()
+	flag = 1;
+	if(setsockopt(w->ofd, IPPROTO_TCP, TCP_NODELAY, (char *) &flag, sizeof(int)) != 0) error("%llu: failed to enable TCP_NODELAY on socket.", w->id);
+
+	// enable sending immediately if we have data
+	if(w->data->bytes) w->wait_send = 1;
+	else w->wait_send = 0;
+
+	// pretty logging
+	switch(w->mode) {
+		case WEB_CLIENT_MODE_NORMAL:
+			debug(D_WEB_CLIENT, "%llu: Done preparing the response. Sending data (%d bytes) to client.", w->id, w->data->bytes);
+			break;
+
+		case WEB_CLIENT_MODE_FILECOPY:
+			if(w->data->rbytes) {
+				debug(D_WEB_CLIENT, "%llu: Done preparing the response. Will be sending data file of %d bytes to client.", w->id, w->data->rbytes);
+				w->wait_receive = 1;
+
+				/*
+				// utilize the kernel sendfile() for copying the file to the socket.
+				// this block of code can be commented, without anything missing.
+				// when it is commented, the program will copy the data using async I/O.
+				{
+					long len = sendfile(w->ofd, w->ifd, NULL, w->data->rbytes);
+					if(len != w->data->rbytes) error("%llu: sendfile() should copy %ld bytes, but copied %ld. Falling back to manual copy.", w->id, w->data->rbytes, len);
+					else web_client_reset(w);
+				}
+				*/
+			}
+			else
+				debug(D_WEB_CLIENT, "%llu: Done preparing the response. Will be sending an unknown amount of bytes to client.", w->id);
+			break;
+
+		default:
+			fatal("%llu: Unknown client mode %d.", w->id, w->mode);
+			break;
+	}
+}
+
+long web_client_send_chunk_header(struct web_client *w, int len)
+{
+	debug(D_DEFLATE, "%llu: OPEN CHUNK of %d bytes (hex: %x).", w->id, len, len);
+	char buf[1024]; 
+	sprintf(buf, "%X\r\n", len);
+	int bytes = send(w->ofd, buf, strlen(buf), MSG_DONTWAIT);
+
+	if(bytes > 0) debug(D_DEFLATE, "%llu: Sent chunk header %d bytes.", w->id, bytes);
+	else if(bytes == 0) debug(D_DEFLATE, "%llu: Did not send chunk header to the client.", w->id);
+	else debug(D_DEFLATE, "%llu: Failed to send chunk header to client. Reason: %s", w->id, strerror(errno));
+
+	return bytes;
+}
+
+long web_client_send_chunk_close(struct web_client *w)
+{
+	//debug(D_DEFLATE, "%llu: CLOSE CHUNK.", w->id);
+
+	int bytes = send(w->ofd, "\r\n", 2, MSG_DONTWAIT);
+
+	if(bytes > 0) debug(D_DEFLATE, "%llu: Sent chunk suffix %d bytes.", w->id, bytes);
+	else if(bytes == 0) debug(D_DEFLATE, "%llu: Did not send chunk suffix to the client.", w->id);
+	else debug(D_DEFLATE, "%llu: Failed to send chunk suffix to client. Reason: %s", w->id, strerror(errno));
+
+	return bytes;
+}
+
+long web_client_send_chunk_finalize(struct web_client *w)
+{
+	//debug(D_DEFLATE, "%llu: FINALIZE CHUNK.", w->id);
+
+	int bytes = send(w->ofd, "\r\n0\r\n\r\n", 7, MSG_DONTWAIT);
+
+	if(bytes > 0) debug(D_DEFLATE, "%llu: Sent chunk suffix %d bytes.", w->id, bytes);
+	else if(bytes == 0) debug(D_DEFLATE, "%llu: Did not send chunk suffix to the client.", w->id);
+	else debug(D_DEFLATE, "%llu: Failed to send chunk suffix to client. Reason: %s", w->id, strerror(errno));
+
+	return bytes;
+}
+
+long web_client_send_deflate(struct web_client *w)
+{
+	long bytes = 0, t = 0;
+
+	// when using compression,
+	// w->data->sent is the amount of bytes passed through compression
+
+	// debug(D_DEFLATE, "%llu: TEST w->data->bytes = %d, w->data->sent = %d, w->zhave = %d, w->zsent = %d, w->zstream.avail_in = %d, w->zstream.avail_out = %d, w->zstream.total_in = %d, w->zstream.total_out = %d.", w->id, w->data->bytes, w->data->sent, w->zhave, w->zsent, w->zstream.avail_in, w->zstream.avail_out, w->zstream.total_in, w->zstream.total_out);
+
+	if(w->data->bytes - w->data->sent == 0 && w->zstream.avail_in == 0 && w->zhave == w->zsent && w->zstream.avail_out != 0) {
+		// there is nothing to send
+
+		debug(D_WEB_CLIENT, "%llu: Out of output data.", w->id);
+
+		// finalize the chunk
+		if(w->data->sent != 0)
+			t += web_client_send_chunk_finalize(w);
+
+		// there can be two cases for this
+		// A. we have done everything
+		// B. we temporarily have nothing to send, waiting for the buffer to be filled by ifd
+
+		if(w->mode == WEB_CLIENT_MODE_FILECOPY && w->wait_receive && w->ifd != w->ofd && w->data->rbytes && w->data->rbytes > w->data->bytes) {
+			// we have to wait, more data will come
+			debug(D_WEB_CLIENT, "%llu: Waiting for more data to become available.", w->id);
+			w->wait_send = 0;
+			return(0);
+		}
+
+		if(w->keepalive == 0) {
+			debug(D_WEB_CLIENT, "%llu: Closing (keep-alive is not enabled). %ld bytes sent.", w->id, w->data->sent);
+			errno = 0;
+			return(-1);
+		}
+
+		// reset the client
+		web_client_reset(w);
+		debug(D_WEB_CLIENT, "%llu: Done sending all data on socket. Waiting for next request on the same socket.", w->id);
+		return(0);
+	}
+
+	if(w->zstream.avail_out == 0 && w->zhave == w->zsent) {
+		// compress more input data
+
+		// close the previous open chunk
+		if(w->data->sent != 0) t += web_client_send_chunk_close(w);
+
+		debug(D_DEFLATE, "%llu: Compressing %d bytes starting from %d.", w->id, (w->data->bytes - w->data->sent), w->data->sent);
+
+		// give the compressor all the data not passed through the compressor yet
+		if(w->data->bytes > w->data->sent) {
+			w->zstream.next_in = (Bytef *)&w->data->buffer[w->data->sent];
+			w->zstream.avail_in = (w->data->bytes - w->data->sent);
+		}
+
+		// reset the compressor output buffer
+		w->zstream.next_out = w->zbuffer;
+		w->zstream.avail_out = ZLIB_CHUNK;
+
+		// ask for FINISH if we have all the input
+		int flush = Z_SYNC_FLUSH;
+		if(w->mode == WEB_CLIENT_MODE_NORMAL
+			|| (w->mode == WEB_CLIENT_MODE_FILECOPY && w->data->bytes == w->data->rbytes)) {
+			flush = Z_FINISH;
+			debug(D_DEFLATE, "%llu: Requesting Z_FINISH.", w->id);
+		}
+		else {
+			debug(D_DEFLATE, "%llu: Requesting Z_SYNC_FLUSH.", w->id);
+		}
+
+		// compress
+		if(deflate(&w->zstream, flush) == Z_STREAM_ERROR) {
+			error("%llu: Compression failed. Closing down client.", w->id);
+			web_client_reset(w);
+			return(-1);
+		}
+
+		w->zhave = ZLIB_CHUNK - w->zstream.avail_out;
+		w->zsent = 0;
+
+		// keep track of the bytes passed through the compressor
+		w->data->sent = w->data->bytes;
+
+		debug(D_DEFLATE, "%llu: Compression produced %d bytes.", w->id, w->zhave);
+
+		// open a new chunk
+		t += web_client_send_chunk_header(w, w->zhave);
+	}
+
+	bytes = send(w->ofd, &w->zbuffer[w->zsent], w->zhave - w->zsent, MSG_DONTWAIT);
+	if(bytes > 0) {
+		w->zsent += bytes;
+		if(t > 0) bytes += t;
+		debug(D_WEB_CLIENT, "%llu: Sent %d bytes.", w->id, bytes);
+	}
+	else if(bytes == 0) debug(D_WEB_CLIENT, "%llu: Did not send any bytes to the client.", w->id);
+	else debug(D_WEB_CLIENT, "%llu: Failed to send data to client. Reason: %s", w->id, strerror(errno));
+
+	return(bytes);
+}
+
+long web_client_send(struct web_client *w)
+{
+	if(w->zoutput) return web_client_send_deflate(w);
+
+	long bytes;
+
+	if(w->data->bytes - w->data->sent == 0) {
+		// there is nothing to send
+
+		debug(D_WEB_CLIENT, "%llu: Out of output data.", w->id);
+
+		// there can be two cases for this
+		// A. we have done everything
+		// B. we temporarily have nothing to send, waiting for the buffer to be filled by ifd
+
+		if(w->mode == WEB_CLIENT_MODE_FILECOPY && w->wait_receive && w->ifd != w->ofd && w->data->rbytes && w->data->rbytes > w->data->bytes) {
+			// we have to wait, more data will come
+			debug(D_WEB_CLIENT, "%llu: Waiting for more data to become available.", w->id);
+			w->wait_send = 0;
+			return(0);
+		}
+
+		if(w->keepalive == 0) {
+			debug(D_WEB_CLIENT, "%llu: Closing (keep-alive is not enabled). %ld bytes sent.", w->id, w->data->sent);
+			errno = 0;
+			return(-1);
+		}
+
+		web_client_reset(w);
+		debug(D_WEB_CLIENT, "%llu: D