Get lingering_close() working again. (a48b7584) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

server/connection.c

+48 −57

Changes for server/connection.c: 48 added lines, 57 removed lines.
Original line number	Diff line number	Diff line
		@@ -75,9 +75,6 @@ HOOK_STRUCT(
		IMPLEMENT_HOOK_VOID(pre_connection,(conn_rec *c),(c))
		IMPLEMENT_HOOK_RUN_FIRST(int,process_connection,(conn_rec *c),(c),DECLINED)

		/* TODO: reimplement the lingering close stuff */
		#define NO_LINGCLOSE

		/*
		* More machine-dependent networking gooo... on some systems,
		* you've got to be really sure that all the packets are acknowledged
		@@ -126,70 +123,65 @@ static void sock_enable_linger(int s)

		#ifndef NO_LINGCLOSE

		/* Since many clients will abort a connection instead of closing it,
		* attempting to log an error message from this routine will only
		* confuse the webmaster. There doesn't seem to be any portable way to
		* distinguish between a dropped connection and something that might be
		* worth logging.
		/* we now proceed to read from the client until we get EOF, or until
		* MAX_SECS_TO_LINGER has passed. the reasons for doing this are
		* documented in a draft:
		*
		* http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-connection-00.txt
		*
		* in a nutshell -- if we don't make this effort we risk causing
		* TCP RST packets to be sent which can tear down a connection before
		* all the response data has been sent to the client.
		*/
		static void lingering_close(request_rec *r)

		static void lingering_close(conn_rec *c)
		{
		/TODO remove the hardwired 512. This is an IO Buffer Size /
		char dummybuf[512];
		struct pollfd pd;
		int lsd;
		int max_wait;

		/* Prevent a slow-drip client from holding us here indefinitely */

		max_wait = 30;
		ap_bsetopt(r->connection->client, BO_TIMEOUT, &max_wait);
		ap_time_t start;
		ap_ssize_t nbytes;
		ap_status_t rc;
		int timeout;

		/* Send any leftover data to the client, but never try to again */

		if (ap_bflush(r->connection->client) != APR_SUCCESS) {
		ap_bclose(r->connection->client);
		if (ap_bflush(c->client) != APR_SUCCESS) {
		ap_bclose(c->client);
		return;
		}
		ap_bsetflag(r->connection->client, B_EOUT, 1);

		/* Close our half of the connection --- send the client a FIN */

		lsd = r->connection->client->fd;
		/* Shut down the socket for write, which will send a FIN
		* to the peer.
		*/

		if ((shutdown(lsd, 1) != 0)
		\|\| ap_is_aborted(r->connection)) {
		ap_bclose(r->connection->client);
		if (ap_bshutdown(c->client, 1) != APR_SUCCESS
		\|\| ap_is_aborted(c)) {
		ap_bclose(c->client);
		return;
		}

		/* Set up to wait for readable data on socket... */
		pd.fd = lsd;
		pd.events = POLLIN;

		/* Wait for readable data or error condition on socket;
		* slurp up any data that arrives... We exit when we go for an
		* interval of tv length without getting any more data, get an error
		* from poll(), get an error or EOF on a read, or the timer expires.
		*/
		/* We use a 2 second timeout because current (Feb 97) browsers
		* fail to close a connection after the server closes it. Thus,
		* to avoid keeping the child busy, we are only lingering long enough
		* for a client that is actively sending data on a connection.
		* This should be sufficient unless the connection is massively
		* losing packets, in which case we might have missed the RST anyway.
		* These parameters are reset on each pass, since they might be
		* changed by poll.
		/* Read all data from the peer until we reach "end-of-file" (FIN
		* from peer) or we've exceeded our overall timeout.
		*/
		do {
		pd.revents = 0;
		} while ((poll(&pd, 1, 2) == 1)
		&& read(lsd, dummybuf, sizeof(dummybuf)));
		/* && (time() = epoch) < max_wait); */

		/* Should now have seen final ack. Safe to finally kill socket */
		ap_bclose(r->connection->client);

		start = ap_now();
		timeout = MAX_SECS_TO_LINGER;
		for (;;) {
		ap_bsetopt(c->client, BO_TIMEOUT, &timeout);
		rc = ap_bread(c->client, dummybuf, sizeof(dummybuf),
		&nbytes);
		if (rc != APR_SUCCESS \|\| nbytes == 0) break;

		/* how much time has elapsed? */
		timeout = (int)((ap_now() - start) / AP_USEC_PER_SEC);
		if (timeout >= MAX_SECS_TO_LINGER) break;

		/* figure out the new timeout */
		timeout = MAX_SECS_TO_LINGER - timeout;
		}

		ap_bclose(c->client);
		}

		#endif /* ndef NO_LINGCLOSE */

		CORE_EXPORT(void) ap_process_connection(conn_rec *c)
		@@ -209,12 +201,11 @@ CORE_EXPORT(void) ap_process_connection(conn_rec *c)
		#ifdef NO_LINGCLOSE
		ap_bclose(c->client); /* just close it */
		#else
		if (r && r->connection
		&& !r->connection->aborted
		&& r->connection->client
		&& (r->connection->client->fd >= 0)) {
		if (!c->aborted
		&& c->client
		/* && (c->client->fd >= 0) */ ) {

		lingering_close(r);
		lingering_close(c);
		}
		else {
		ap_bsetflag(c->client, B_EOUT, 1);

server/mpm/winnt/mpm_winnt.c

+28 −0

Changes for server/mpm/winnt/mpm_winnt.c: 28 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -886,6 +886,20 @@ static int create_acceptex_context(ap_context_t _pconf, ap_listen_rec lr)
		"create_acceptex_context: AcceptEx failed. Process will exit.");
		return -1;
		}

		/* SO_UPDATE_ACCEPT_CONTEXT is a Microsoft-ism which is required
		* if you want to use more than several key socket calls on a
		* socket initialized via AcceptEx(). In particular, it is
		* required for shutdown() to work.
		*/

		if (setsockopt(context->accept_socket, SOL_SOCKET,
		SO_UPDATE_ACCEPT_CONTEXT, (char *)&nsd,
		sizeof(nsd))) {
		ap_log_error(APLOG_MARK, APLOG_ERR, WSAGetLastError(), server_conf,
		"setsockopt(SO_UPDATE_ACCEPT_CONTEXT) failed.");
		}

		}
		lr->count++;

		@@ -926,6 +940,20 @@ static ap_inline int reset_acceptex_context(PCOMP_CONTEXT context)
		"reset_acceptex_context: AcceptEx failed. Leaving the process running.");
		return -1;
		}

		/* SO_UPDATE_ACCEPT_CONTEXT is a Microsoft-ism which is required
		* if you want to use more than several key socket calls on a
		* socket initialized via AcceptEx(). In particular, it is
		* required for shutdown() to work.
		*/

		if (setsockopt(context->accept_socket, SOL_SOCKET,
		SO_UPDATE_ACCEPT_CONTEXT, (char *)&nsd,
		sizeof(nsd))) {
		ap_log_error(APLOG_MARK, APLOG_WARNING, WSAGetLastError(),
		server_conf,
		"setsockopt(SO_UPDATE_ACCEPT_CONTEXT) failed.");
		}
		}

		return 0;