lighttpd1.4/src/connections.c

#include <sys/stat.h>

#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <assert.h>

#include "buffer.h"
#include "server.h"
#include "log.h"
#include "connections.h"
#include "fdevent.h"

#include "request.h"
#include "response.h"
#include "network.h"
#include "http_chunk.h"
#include "stat_cache.h"
#include "joblist.h"

#include "plugin.h"

#include "inet_ntop_cache.h"

#ifdef USE_OPENSSL
# include <openssl/ssl.h> 
# include <openssl/err.h> 
#endif

#ifdef HAVE_SYS_FILIO_H
# include <sys/filio.h>
#endif

#include "sys-socket.h"

typedef struct {
	        PLUGIN_DATA;
} plugin_data;

static connection *connections_get_new_connection(server *srv) {
	connections *conns = srv->conns;
	size_t i;
	
	if (conns->size == 0) {
		conns->size = 128;
		conns->ptr = NULL;
		conns->ptr = malloc(sizeof(*conns->ptr) * conns->size);
		for (i = 0; i < conns->size; i++) {
			conns->ptr[i] = connection_init(srv);
		}
	} else if (conns->size == conns->used) {
		conns->size += 128;
		conns->ptr = realloc(conns->ptr, sizeof(*conns->ptr) * conns->size);
		
		for (i = conns->used; i < conns->size; i++) {
			conns->ptr[i] = connection_init(srv);
		}
	}

	connection_reset(srv, conns->ptr[conns->used]);
#if 0	
	fprintf(stderr, "%s.%d: add: ", __FILE__, __LINE__);
	for (i = 0; i < conns->used + 1; i++) {
		fprintf(stderr, "%d ", conns->ptr[i]->fd);
	}
	fprintf(stderr, "\n");
#endif	
	
	conns->ptr[conns->used]->ndx = conns->used;
	return conns->ptr[conns->used++];
}

static int connection_del(server *srv, connection *con) {
	size_t i;
	connections *conns = srv->conns;
	connection *temp;
	
	if (con == NULL) return -1;
	
	if (-1 == con->ndx) return -1;
	
	i = con->ndx;
	
	/* not last element */
	
	if (i != conns->used - 1) {
		temp = conns->ptr[i];
		conns->ptr[i] = conns->ptr[conns->used - 1];
		conns->ptr[conns->used - 1] = temp;
		
		conns->ptr[i]->ndx = i;
		conns->ptr[conns->used - 1]->ndx = -1;
	}
	
	conns->used--;
	
	con->ndx = -1;
#if 0
	fprintf(stderr, "%s.%d: del: (%d)", __FILE__, __LINE__, conns->used);
	for (i = 0; i < conns->used; i++) {
		fprintf(stderr, "%d ", conns->ptr[i]->fd);
	}
	fprintf(stderr, "\n");
#endif	
	return 0;
}

int connection_close(server *srv, connection *con) {
#ifdef USE_OPENSSL
	server_socket *srv_sock = con->srv_socket;
#endif
	
#ifdef USE_OPENSSL
	if (srv_sock->is_ssl) {
		if (con->ssl) SSL_free(con->ssl);
		con->ssl = NULL;
	}
#endif
	
	fdevent_event_del(srv->ev, &(con->fde_ndx), con->fd);
	fdevent_unregister(srv->ev, con->fd);
#ifdef __WIN32
	if (closesocket(con->fd)) {
		log_error_write(srv, __FILE__, __LINE__, "sds",
				"(warning) close:", con->fd, strerror(errno));
	}
#else
	if (close(con->fd)) {
		log_error_write(srv, __FILE__, __LINE__, "sds",
				"(warning) close:", con->fd, strerror(errno));
	}
#endif
	
	srv->cur_fds--;
#if 0
	log_error_write(srv, __FILE__, __LINE__, "sd",
			"closed()", con->fd);
#endif
	
	connection_del(srv, con);
	connection_set_state(srv, con, CON_STATE_CONNECT);
	
	return 0;
}

#if 0
static void dump_packet(const unsigned char *data, size_t len) {
	size_t i, j;
	
	if (len == 0) return;
	
	for (i = 0; i < len; i++) {
		if (i % 16 == 0) fprintf(stderr, "  ");
		
		fprintf(stderr, "%02x ", data[i]);
		
		if ((i + 1) % 16 == 0) {
			fprintf(stderr, "  ");
			for (j = 0; j <= i % 16; j++) {
				unsigned char c;
				
				if (i-15+j >= len) break;
				
				c = data[i-15+j];
				
				fprintf(stderr, "%c", c > 32 && c < 128 ? c : '.');
			}
			
			fprintf(stderr, "\n");
		}
	}
	
	if (len % 16 != 0) {
		for (j = i % 16; j < 16; j++) {
			fprintf(stderr, "   ");
		}
		
		fprintf(stderr, "  ");
		for (j = i & ~0xf; j < len; j++) {
			unsigned char c;
			
			c = data[j];
			fprintf(stderr, "%c", c > 32 && c < 128 ? c : '.');
		}
		fprintf(stderr, "\n");
	}
}
#endif 

static int connection_handle_read(server *srv, connection *con) {
	int len;
	buffer *b;
	int toread;
#ifdef USE_OPENSSL
	server_socket *srv_sock = con->srv_socket;
#endif

	b = chunkqueue_get_append_buffer(con->read_queue);
	buffer_prepare_copy(b, 4096);

#ifdef USE_OPENSSL
	if (srv_sock->is_ssl) {
		len = SSL_read(con->ssl, b->ptr, b->size - 1);
	} else {
		if (ioctl(con->fd, FIONREAD, &toread)) {
			log_error_write(srv, __FILE__, __LINE__, "sd", 
					"unexpected end-of-file:",
					con->fd);
			return -1;
		}
		buffer_prepare_copy(b, toread);

		len = read(con->fd, b->ptr, b->size - 1);
	}
#elif defined(__WIN32)
	len = recv(con->fd, b->ptr, b->size - 1, 0);
#else
	if (ioctl(con->fd, FIONREAD, &toread)) {
		log_error_write(srv, __FILE__, __LINE__, "sd", 
				"unexpected end-of-file:",
				con->fd);
		return -1;
	}
	buffer_prepare_copy(b, toread);

	len = read(con->fd, b->ptr, b->size - 1);
#endif
	
	if (len < 0) {
		con->is_readable = 0;
		
#ifdef USE_OPENSSL
		if (srv_sock->is_ssl) {
			int r, ssl_err;
			
			switch ((r = SSL_get_error(con->ssl, len))) {
			case SSL_ERROR_WANT_READ:
				return 0;
			case SSL_ERROR_SYSCALL:
				/**
				 * man SSL_get_error()
				 * 
				 * SSL_ERROR_SYSCALL
				 *   Some I/O error occurred.  The OpenSSL error queue may contain more 
				 *   information on the error.  If the error queue is empty (i.e.
				 *   ERR_get_error() returns 0), ret can be used to find out more about 
				 *   the error: If ret == 0, an EOF was observed that violates the
				 *   protocol.  If ret == -1, the underlying BIO reported an I/O error 
				 *   (for socket I/O on Unix systems, consult errno for details).
				 *
				 */
				while((ssl_err = ERR_get_error())) {
					/* get all errors from the error-queue */
					log_error_write(srv, __FILE__, __LINE__, "sds", "SSL:", 
							r, ERR_error_string(ssl_err, NULL));
				}

				switch(errno) {
				default:
					log_error_write(srv, __FILE__, __LINE__, "sddds", "SSL:", 
							len, r, errno,
							strerror(errno));
					break;
				}
				
				break;
			case SSL_ERROR_ZERO_RETURN:
				/* clean shutdown on the remote side */
				
				if (r == 0) {
					/* FIXME: later */
				}
				
				/* fall thourgh */
			default:
				while((ssl_err = ERR_get_error())) {
					/* get all errors from the error-queue */
					log_error_write(srv, __FILE__, __LINE__, "sds", "SSL:", 
							r, ERR_error_string(ssl_err, NULL));
				}
				break;
			}
		} else {
			if (errno == EAGAIN) return 0;
			if (errno == EINTR) {
				/* we have been interrupted before we could read */
				con->is_readable = 1;
				return 0;
			}
		
			if (errno != ECONNRESET) {
				/* expected for keep-alive */
				log_error_write(srv, __FILE__, __LINE__, "ssd", "connection closed - read failed: ", strerror(errno), errno);
			}
		}
#else
		if (errno == EAGAIN) return 0;
		if (errno == EINTR) {
			/* we have been interrupted before we could read */
			con->is_readable = 1;
			return 0;
		}
		
		if (errno != ECONNRESET) {
			/* expected for keep-alive */
			log_error_write(srv, __FILE__, __LINE__, "ssd", "connection closed - read failed: ", strerror(errno), errno);
		}
#endif
		connection_set_state(srv, con, CON_STATE_ERROR);
		
		return -1;
	} else if (len == 0) {
		con->is_readable = 0;
		/* the other end close the connection -> KEEP-ALIVE */

		/* pipelining */

		return -2;
	} else if ((size_t)len < b->size - 1) {
		/* we got less then expected, wait for the next fd-event */
		
		con->is_readable = 0;
	}
	
	b->used = len;
	b->ptr[b->used++] = '\0';
	
	con->bytes_read += len;
#if 0
	dump_packet(b->ptr, len);
#endif
	
	return 0;
}

static int connection_handle_write_prepare(server *srv, connection *con) {
	if (con->mode == DIRECT) {
		/* static files */
		switch(con->request.http_method) {
		case HTTP_METHOD_GET:
		case HTTP_METHOD_POST:
		case HTTP_METHOD_HEAD:
		case HTTP_METHOD_PUT:
		case HTTP_METHOD_MKCOL:
		case HTTP_METHOD_DELETE:
		case HTTP_METHOD_COPY:
		case HTTP_METHOD_MOVE:
		case HTTP_METHOD_PROPFIND:
		case HTTP_METHOD_PROPPATCH:
			break;
		case HTTP_METHOD_OPTIONS:
			/*
			 * 400 is coming from the request-parser BEFORE uri.path is set
			 * 403 is from the response handler when noone else catched it 
			 * 
			 * */
			if (con->uri.path->used &&
			    con->uri.path->ptr[0] != '*') {
				response_header_insert(srv, con, CONST_STR_LEN("Allow"), CONST_STR_LEN("OPTIONS, GET, HEAD, POST"));

				con->http_status = 200;
				con->file_finished = 1;

				chunkqueue_reset(con->write_queue);
			}
			break;
		default:
			switch(con->http_status) {
			case 400: /* bad request */
			case 505: /* unknown protocol */
			case 207: /* this was webdav */
				break;
			default:
				con->http_status = 501;
				break;
			}
			break;
		}
	}
	
	if (con->http_status == 0) {
		con->http_status = 403;
	}
	
	switch(con->http_status) {
	case 400: /* class: header + custom body */
	case 401:
	case 403:
	case 404:
	case 408:
	case 411:
	case 416:
	case 500:
	case 501:
	case 503:
	case 505: 
		if (con->mode != DIRECT) break;
		
		con->file_finished = 0;
		
		buffer_reset(con->physical.path);
				
		/* try to send static errorfile */
		if (!buffer_is_empty(con->conf.errorfile_prefix)) {
			stat_cache_entry *sce = NULL;
			
			buffer_copy_string_buffer(con->physical.path, con->conf.errorfile_prefix);
			buffer_append_string(con->physical.path, get_http_status_body_name(con->http_status));
			
			if (HANDLER_ERROR != stat_cache_get_entry(srv, con, con->physical.path, &sce)) {
				con->file_finished = 1;
				
				http_chunk_append_file(srv, con, con->physical.path, 0, sce->st.st_size);
				response_header_overwrite(srv, con, CONST_STR_LEN("Content-Type"), CONST_BUF_LEN(sce->content_type));
			}
		}
		
		if (!con->file_finished) {			
			buffer *b;
			
			buffer_reset(con->physical.path);
			
			con->file_finished = 1;
			b = chunkqueue_get_append_buffer(con->write_queue);
				
			/* build default error-page */
			buffer_copy_string(b, 
					   "<?xml version=\"1.0\" encoding=\"iso-8859-1\"?>\n"
					   "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\"\n"
					   "         \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\">\n"
					   "<html xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"en\" lang=\"en\">\n"
					   " <head>\n"
					   "  <title>");
			buffer_append_long(b, con->http_status);
			buffer_append_string(b, " - ");
			buffer_append_string(b, get_http_status_name(con->http_status));
			
			buffer_append_string(b,
					     "</title>\n"
					     " </head>\n"
					     " <body>\n"
					     "  <h1>");
			buffer_append_long(b, con->http_status);
			buffer_append_string(b, " - ");
			buffer_append_string(b, get_http_status_name(con->http_status));
			
			buffer_append_string(b,"</h1>\n" 
					     " </body>\n"
					     "</html>\n"
					     );
			
			response_header_overwrite(srv, con, CONST_STR_LEN("Content-Type"), CONST_STR_LEN("text/html"));
		}
		/* fall through */
	case 207:
	case 200: /* class: header + body */
	case 302:
		break;
		
	case 206: /* write_queue is already prepared */
		con->file_finished = 1;
		
		break;
	case 205: /* class: header only */
	case 301:
	case 304:
	default:
		/* disable chunked encoding again as we have no body */
		con->response.transfer_encoding &= ~HTTP_TRANSFER_ENCODING_CHUNKED;
		chunkqueue_reset(con->write_queue);
		
		con->file_finished = 1;
		break;
	}
	

	if (con->file_finished) {
		/* we have all the content and chunked encoding is not used, set a content-length */ 
		
		if ((!(con->parsed_response & HTTP_CONTENT_LENGTH)) && 
		    (con->response.transfer_encoding & HTTP_TRANSFER_ENCODING_CHUNKED) == 0) {
			buffer_copy_off_t(srv->tmp_buf, chunkqueue_length(con->write_queue));
		
			response_header_overwrite(srv, con, CONST_STR_LEN("Content-Length"), CONST_BUF_LEN(srv->tmp_buf));
		}
	} else {
		/* disable keep-alive if size-info for the body is missing */
		if ((con->parsed_response & HTTP_CONTENT_LENGTH) &&
		    ((con->response.transfer_encoding & HTTP_TRANSFER_ENCODING_CHUNKED) == 0)) {
			con->keep_alive = 0;
		}
		
		if (0 == (con->parsed_response & HTTP_CONNECTION)) {
			/* (f)cgi did'nt send Connection: header
			 *                          
			 * shall we ?
			 */
			if (((con->response.transfer_encoding & HTTP_TRANSFER_ENCODING_CHUNKED) == 0) &&
			    (con->parsed_response & HTTP_CONTENT_LENGTH) == 0) {
				/* without content_length, no keep-alive */
				
				con->keep_alive = 0;
			}
		} else {
			/* a subrequest disable keep-alive although the client wanted it */
			if (con->keep_alive && !con->response.keep_alive) {
				con->keep_alive = 0;
				
				/* FIXME: we have to drop the Connection: Header from the subrequest */
			}
		}
	}
	
	if (con->request.http_method == HTTP_METHOD_HEAD) {
		chunkqueue_reset(con->write_queue);
	}

	http_response_write_header(srv, con);
		
	return 0;
}

static int connection_handle_write(server *srv, connection *con) {
	switch(network_write_chunkqueue(srv, con, con->write_queue)) {
	case 0:
		if (con->file_finished) {
			connection_set_state(srv, con, CON_STATE_RESPONSE_END);
			joblist_append(srv, con);
		}
		break;
	case -1: /* error on our side */
		log_error_write(srv, __FILE__, __LINE__, "sd",
				"connection closed: write failed on fd", con->fd);
		connection_set_state(srv, con, CON_STATE_ERROR);
		joblist_append(srv, con);
		break;
	case -2: /* remote close */
		connection_set_state(srv, con, CON_STATE_ERROR);
		joblist_append(srv, con);
		break;
	case 1:
		con->is_writable = 0;
		
		/* not finished yet -> WRITE */
		break;
	}
	
	return 0;
}



connection *connection_init(server *srv) {
	connection *con;
	
	UNUSED(srv);

	con = calloc(1, sizeof(*con));
		
	con->fd = 0;
	con->ndx = -1;
	con->fde_ndx = -1;
	con->bytes_written = 0;
	con->bytes_read = 0;
	con->bytes_header = 0;
	con->loops_per_request = 0;

#define CLEAN(x) \
	con->x = buffer_init();
	
	CLEAN(request.uri);
	CLEAN(request.request_line);
	CLEAN(request.request);
	CLEAN(request.pathinfo);
	
	CLEAN(request.orig_uri);
	
	CLEAN(uri.scheme);
	CLEAN(uri.authority);
	CLEAN(uri.path);
	CLEAN(uri.path_raw);
	CLEAN(uri.query);
	
	CLEAN(physical.doc_root);
	CLEAN(physical.path);
	CLEAN(physical.basedir);
	CLEAN(physical.rel_path);
	CLEAN(physical.etag);
	CLEAN(parse_request);
	
	CLEAN(authed_user);
	CLEAN(server_name);
	CLEAN(error_handler);
	CLEAN(dst_addr_buf);
	
#undef CLEAN
	con->write_queue = chunkqueue_init();
	con->read_queue = chunkqueue_init();
	con->request_content_queue = chunkqueue_init();
	chunkqueue_set_tempdirs(con->request_content_queue, srv->srvconf.upload_tempdirs);

	con->request.headers      = array_init();
	con->response.headers     = array_init();
	con->environment     = array_init();
	
	/* init plugin specific connection structures */
	
	con->plugin_ctx = calloc(1, (srv->plugins.used + 1) * sizeof(void *));
	
	con->cond_cache = calloc(srv->config_context->used, sizeof(cond_cache_t));
	config_setup_connection(srv, con);
	
	return con;
}

void connections_free(server *srv) {
	connections *conns = srv->conns;
	size_t i;	
	
	for (i = 0; i < conns->size; i++) {
		connection *con = conns->ptr[i];
		
		connection_reset(srv, con);
		
		chunkqueue_free(con->write_queue);
		chunkqueue_free(con->read_queue);
		chunkqueue_free(con->request_content_queue);
		array_free(con->request.headers);
		array_free(con->response.headers);
		array_free(con->environment);

#define CLEAN(x) \
	buffer_free(con->x);
		
		CLEAN(request.uri);
		CLEAN(request.request_line);
		CLEAN(request.request);
		CLEAN(request.pathinfo);
		
		CLEAN(request.orig_uri);
		
		CLEAN(uri.scheme);
		CLEAN(uri.authority);
		CLEAN(uri.path);
		CLEAN(uri.path_raw);
		CLEAN(uri.query);
		
		CLEAN(physical.doc_root);
		CLEAN(physical.path);
		CLEAN(physical.basedir);
		CLEAN(physical.etag);
		CLEAN(physical.rel_path);
		CLEAN(parse_request);
		
		CLEAN(authed_user);
		CLEAN(server_name);
		CLEAN(error_handler);
		CLEAN(dst_addr_buf);
#undef CLEAN
		free(con->plugin_ctx);
		free(con->cond_cache);
		
		free(con);
	}
	
	free(conns->ptr);
}


int connection_reset(server *srv, connection *con) {
	size_t i;
	
	plugins_call_connection_reset(srv, con);
	
	con->is_readable = 1;
	con->is_writable = 1;
	con->http_status = 0;
	con->file_finished = 0;
	con->file_started = 0;
	con->got_response = 0;
	
	con->parsed_response = 0;
	
	con->bytes_written = 0;
	con->bytes_written_cur_second = 0;
	con->bytes_read = 0;
	con->bytes_header = 0;
	con->loops_per_request = 0;
	
	con->request.http_method = HTTP_METHOD_UNSET;
	con->request.http_version = HTTP_VERSION_UNSET;
	
	con->request.http_if_modified_since = NULL;
	con->request.http_if_none_match = NULL;
	
	con->response.keep_alive = 0;
	con->response.content_length = -1;
	con->response.transfer_encoding = 0;
	
	con->mode = DIRECT;
	
#define CLEAN(x) \
	if (con->x) buffer_reset(con->x);
	
	CLEAN(request.uri);
	CLEAN(request.request_line);
	CLEAN(request.pathinfo);
	CLEAN(request.request);
	
	CLEAN(request.orig_uri);
	
	CLEAN(uri.scheme);
	CLEAN(uri.authority);
	CLEAN(uri.path);
	CLEAN(uri.path_raw);
	CLEAN(uri.query);
	
	CLEAN(physical.doc_root);
	CLEAN(physical.path);
	CLEAN(physical.basedir);
	CLEAN(physical.rel_path);
	CLEAN(physical.etag);
	
	CLEAN(parse_request);
	
	CLEAN(authed_user);
	CLEAN(server_name);
	CLEAN(error_handler);
#undef CLEAN	
	
#define CLEAN(x) \
	if (con->x) con->x->used = 0;	
	
#undef CLEAN
	
#define CLEAN(x) \
		con->request.x = NULL;
	
	CLEAN(http_host);
	CLEAN(http_range);
	CLEAN(http_content_type);
#undef CLEAN
	con->request.content_length = 0;
	
	array_reset(con->request.headers);
	array_reset(con->response.headers);
	array_reset(con->environment);
	
	chunkqueue_reset(con->write_queue);
	chunkqueue_reset(con->request_content_queue);

	/* the plugins should cleanup themself */	
	for (i = 0; i < srv->plugins.used; i++) {
		plugin *p = ((plugin **)(srv->plugins.ptr))[i];
		plugin_data *pd = p->data;

		if (!pd) continue;

		if (con->plugin_ctx[pd->id] != NULL) {
			log_error_write(srv, __FILE__, __LINE__, "sb", "missing cleanup in", p->name);
		}

		con->plugin_ctx[pd->id] = NULL;
	}
	
#if COND_RESULT_UNSET
	for (i = srv->config_context->used - 1; i >= 0; i --) {
		con->cond_cache[i].result = COND_RESULT_UNSET;
		con->cond_cache[i].patterncount = 0;
	}
#else
	memset(con->cond_cache, 0, sizeof(cond_cache_t) * srv->config_context->used);
#endif
	
	con->header_len = 0;
	con->in_error_handler = 0;
	
	config_setup_connection(srv, con);
	
	return 0;
}

/**
 * 
 * search for \r\n\r\n 
 * 
 * this is a special 32bit version which is using a sliding window for
 * the comparisions 
 * 
 * how it works:
 * 
 * b:      'abcdefg'
 * rnrn:   'cdef'
 * 
 * cmpbuf: abcd != cdef
 * cmpbuf: bcde != cdef
 * cmpbuf: cdef == cdef -> return &c
 * 
 * cmpbuf and rnrn are treated as 32bit uint and bit-ops are used to 
 * maintain cmpbuf and rnrn
 * 
 */

char *buffer_search_rnrn(buffer *b) {
	uint32_t cmpbuf, rnrn;
	char *cp;
	size_t i;
	
	if (b->used < 4) return NULL;
	
	rnrn = ('\r' << 24) | ('\n' << 16) |
		('\r' << 8) | ('\n' << 0);
	
	cmpbuf = (b->ptr[0] << 24) | (b->ptr[1] << 16) |
		(b->ptr[2] << 8) | (b->ptr[3] << 0);
		
	cp = b->ptr + 4;
	for (i = 0; i < b->used - 4; i++) {
		if (cmpbuf == rnrn) return cp - 4;
			
		cmpbuf = (cmpbuf << 8 | *(cp++)) & 0xffffffff;
	}
	
	return NULL;
}
/**
 * handle all header and content read
 *
 * we get called by the state-engine and by the fdevent-handler
 */
int connection_handle_read_state(server *srv, connection *con)  {
	int ostate = con->state;
	char *h_term = NULL;
	chunk *c;
	chunkqueue *cq = con->read_queue;
	chunkqueue *dst_cq = con->request_content_queue;
	
	if (con->is_readable) {
		con->read_idle_ts = srv->cur_ts;
	
		switch(connection_handle_read(srv, con)) {
		case -1:
			return -1;
		case -2:
			/* remote side closed the connection
			 * if we still have content, handle it, if not leave here */

			if (cq->first == cq->last &&
			    cq->first->mem->used == 0) {

				/* conn-closed, leave here */
				connection_set_state(srv, con, CON_STATE_ERROR);
			}
		default:
			break;
		}
	}

	/* the last chunk might be empty */
	for (c = cq->first; c;) {
		if (cq->first == c && c->mem->used == 0) {
			/* the first node is empty */
			/* ... and it is empty, move it to unused */

			cq->first = c->next;
			if (cq->first == NULL) cq->last = NULL;

			c->next = cq->unused;
			cq->unused = c;
			cq->unused_chunks++;

			c = cq->first;
		} else if (c->next && c->next->mem->used == 0) {
			chunk *fc;
			/* next node is the last one */
			/* ... and it is empty, move it to unused */

			fc = c->next;
			c->next = fc->next;

			fc->next = cq->unused;
			cq->unused = fc;
			cq->unused_chunks++;

			/* the last node was empty */
			if (c->next == NULL) {
				cq->last = c;
			} 

			c = c->next;
		} else {
			c = c->next;
		}
	}
	
	/* nothing to handle */
	if (cq->first == NULL) return 0;

	switch(ostate) {
	case CON_STATE_READ:
		/* prepare con->request.request */
		c = cq->first;
		
		/* check if we need the full package */
		if (con->request.request->used == 0) {
			buffer b;
			
			b.ptr = c->mem->ptr + c->offset;
			b.used = c->mem->used - c->offset;
			
			if (NULL != (h_term = buffer_search_rnrn(&b))) {
				/* \r\n\r\n found
				 * - copy everything incl. the terminator to request.request
				 */
				
				buffer_copy_string_len(con->request.request, 
						       b.ptr, 
						       h_term - b.ptr + 4);
				
				/* the buffer has been read up to the terminator */
				c->offset += h_term - b.ptr + 4;
			} else {
				/* not found, copy everything */
				buffer_copy_string_len(con->request.request, c->mem->ptr + c->offset, c->mem->used - c->offset - 1);
				c->offset = c->mem->used - 1;
			}
		} else {
			/* have to take care of overlapping header terminators */
			
			size_t l = con->request.request->used - 2;
			char *s  = con->request.request->ptr;
			buffer b;
			
			b.ptr = c->mem->ptr + c->offset;
			b.used = c->mem->used - c->offset;