src/raw_sock.c - haproxy - Gitiles

 /*
  * RAW transport layer over SOCK_STREAM sockets.
  *
  * Copyright 2000-2012 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  *
  */

 #define _GNU_SOURCE
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>

 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>

 #include <netinet/tcp.h>

 #include <haproxy/api.h>
 #include <haproxy/buf.h>
 #include <haproxy/connection.h>
 #include <haproxy/global.h>
 #include <haproxy/log.h>
 #include <haproxy/stream_interface.h>
 #include <haproxy/tools.h>
 #include <haproxy/ticks.h>
 #include <haproxy/time.h>

 #include <haproxy/fd.h>
 #include <haproxy/freq_ctr.h>
 #include <haproxy/pipe.h>


 #if defined(USE_LINUX_SPLICE)

 /* A pipe contains 16 segments max, and it's common to see segments of 1448 bytes
  * because of timestamps. Use this as a hint for not looping on splice().
  */
 #define SPLICE_FULL_HINT	16*1448

 /* how many data we attempt to splice at once when the buffer is configured for
  * infinite forwarding */
 #define MAX_SPLICE_AT_ONCE	(1<<30)

 /* Returns :
  *   -1 if splice() is not supported
  *   >= 0 to report the amount of spliced bytes.
  *   connection flags are updated (error, read0, wait_room, wait_data).
  *   The caller must have previously allocated the pipe.
  */
 int raw_sock_to_pipe(struct connection *conn, void *xprt_ctx, struct pipe *pipe, unsigned int count)
 {
 	int ret;
 	int retval = 0;


 	if (!conn_ctrl_ready(conn))
 		return 0;

 	if (!fd_recv_ready(conn->handle.fd))
 		return 0;

 	conn->flags &= ~CO_FL_WAIT_ROOM;
 	errno = 0;

 	/* Under Linux, if FD_POLL_HUP is set, we have reached the end.
 	 * Since older splice() implementations were buggy and returned
 	 * EAGAIN on end of read, let's bypass the call to splice() now.
 	 */
 	if (unlikely(!(fdtab[conn->handle.fd].ev & FD_POLL_IN))) {
 		/* stop here if we reached the end of data */
 		if ((fdtab[conn->handle.fd].ev & (FD_POLL_ERR|FD_POLL_HUP)) == FD_POLL_HUP)
 			goto out_read0;

 		/* report error on POLL_ERR before connection establishment */
 		if ((fdtab[conn->handle.fd].ev & FD_POLL_ERR) && (conn->flags & CO_FL_WAIT_L4_CONN)) {
 			conn->flags |= CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH;
 			errno = 0; /* let the caller do a getsockopt() if it wants it */
 			goto leave;
 		}
 	}

 	while (count) {
 		if (count > MAX_SPLICE_AT_ONCE)
 			count = MAX_SPLICE_AT_ONCE;

 		ret = splice(conn->handle.fd, NULL, pipe->prod, NULL, count,
 			     SPLICE_F_MOVE|SPLICE_F_NONBLOCK);

 		if (ret <= 0) {
 			if (ret == 0)
 				goto out_read0;

 			if (errno == EAGAIN) {
 				/* there are two reasons for EAGAIN :
 				 *   - nothing in the socket buffer (standard)
 				 *   - pipe is full
 				 * The difference between these two situations
 				 * is problematic. Since we don't know if the
 				 * pipe is full, we'll stop if the pipe is not
 				 * empty. Anyway, we will almost always fill or
 				 * empty the pipe.
 				 */
 				if (pipe->data) {
 					/* always stop reading until the pipe is flushed */
 					conn->flags |= CO_FL_WAIT_ROOM;
 					break;
 				}
 				/* socket buffer exhausted */
 				fd_cant_recv(conn->handle.fd);
 				break;
 			}
 			else if (errno == ENOSYS || errno == EINVAL || errno == EBADF) {
 				/* splice not supported on this end, disable it.
 				 * We can safely return -1 since there is no
 				 * chance that any data has been piped yet.
 				 */
 				retval = -1;
 				goto leave;
 			}
 			else if (errno == EINTR) {
 				/* try again */
 				continue;
 			}
 			/* here we have another error */
 			conn->flags |= CO_FL_ERROR;
 			break;
 		} /* ret <= 0 */

 		retval += ret;
 		pipe->data += ret;
 		count -= ret;

 		if (pipe->data >= SPLICE_FULL_HINT || ret >= global.tune.recv_enough) {
 			/* We've read enough of it for this time, let's stop before
 			 * being asked to poll.
 			 */
 			conn->flags |= CO_FL_WAIT_ROOM;
 			break;
 		}
 	} /* while */

 	if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) && retval)
 		conn->flags &= ~CO_FL_WAIT_L4_CONN;

  leave:
 	if (retval > 0) {
 		/* we count the total bytes sent, and the send rate for 32-byte
 		 * blocks. The reason for the latter is that freq_ctr are
 		 * limited to 4GB and that it's not enough per second.
 		 */
 		_HA_ATOMIC_ADD(&global.out_bytes, retval);
 		update_freq_ctr(&global.out_32bps, (retval + 16) / 32);
 	}
 	return retval;

  out_read0:
 	conn_sock_read0(conn);
 	conn->flags &= ~CO_FL_WAIT_L4_CONN;
 	goto leave;
 }

 /* Send as many bytes as possible from the pipe to the connection's socket.
  */
 int raw_sock_from_pipe(struct connection *conn, void *xprt_ctx, struct pipe *pipe)
 {
 	int ret, done;

 	if (!conn_ctrl_ready(conn))
 		return 0;

 	if (!fd_send_ready(conn->handle.fd))
 		return 0;

 	if (conn->flags & CO_FL_SOCK_WR_SH) {
 		/* it's already closed */
 		conn->flags |= CO_FL_ERROR | CO_FL_SOCK_RD_SH;
 		errno = EPIPE;
 		return 0;
 	}

 	done = 0;
 	while (pipe->data) {
 		ret = splice(pipe->cons, NULL, conn->handle.fd, NULL, pipe->data,
 			     SPLICE_F_MOVE|SPLICE_F_NONBLOCK);

 		if (ret <= 0) {
 			if (ret == 0 || errno == EAGAIN) {
 				fd_cant_send(conn->handle.fd);
 				break;
 			}
 			else if (errno == EINTR)
 				continue;

 			/* here we have another error */
 			conn->flags |= CO_FL_ERROR;
 			break;
 		}

 		done += ret;
 		pipe->data -= ret;
 	}
 	if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) && done) {
 		conn->flags &= ~CO_FL_WAIT_L4_CONN;
 	}

 	return done;
 }

 #endif /* USE_LINUX_SPLICE */


 /* Receive up to <count> bytes from connection <conn>'s socket and store them
  * into buffer <buf>. Only one call to recv() is performed, unless the
  * buffer wraps, in which case a second call may be performed. The connection's
  * flags are updated with whatever special event is detected (error, read0,
  * empty). The caller is responsible for taking care of those events and
  * avoiding the call if inappropriate. The function does not call the
  * connection's polling update function, so the caller is responsible for this.
  * errno is cleared before starting so that the caller knows that if it spots an
  * error without errno, it's pending and can be retrieved via getsockopt(SO_ERROR).
  */
 static size_t raw_sock_to_buf(struct connection *conn, void *xprt_ctx, struct buffer *buf, size_t count, int flags)
 {
 	ssize_t ret;
 	size_t try, done = 0;

 	if (!conn_ctrl_ready(conn))
 		return 0;

 	if (!fd_recv_ready(conn->handle.fd))
 		return 0;

 	conn->flags &= ~CO_FL_WAIT_ROOM;
 	errno = 0;

 	if (unlikely(!(fdtab[conn->handle.fd].ev & FD_POLL_IN))) {
 		/* stop here if we reached the end of data */
 		if ((fdtab[conn->handle.fd].ev & (FD_POLL_ERR|FD_POLL_HUP)) == FD_POLL_HUP)
 			goto read0;

 		/* report error on POLL_ERR before connection establishment */
 		if ((fdtab[conn->handle.fd].ev & FD_POLL_ERR) && (conn->flags & CO_FL_WAIT_L4_CONN)) {
 			conn->flags |= CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH;
 			goto leave;
 		}
 	}

 	/* read the largest possible block. For this, we perform only one call
 	 * to recv() unless the buffer wraps and we exactly fill the first hunk,
 	 * in which case we accept to do it once again. A new attempt is made on
 	 * EINTR too.
 	 */
 	while (count > 0) {
 		try = b_contig_space(buf);
 		if (!try)
 			break;

 		if (try > count)
 			try = count;

 		ret = recv(conn->handle.fd, b_tail(buf), try, 0);

 		if (ret > 0) {
 			b_add(buf, ret);
 			done += ret;
 			if (ret < try) {
 				/* socket buffer exhausted */
 				fd_cant_recv(conn->handle.fd);

 				/* unfortunately, on level-triggered events, POLL_HUP
 				 * is generally delivered AFTER the system buffer is
 				 * empty, unless the poller supports POLL_RDHUP. If
 				 * we know this is the case, we don't try to read more
 				 * as we know there's no more available. Similarly, if
 				 * there's no problem with lingering we don't even try
 				 * to read an unlikely close from the client since we'll
 				 * close first anyway.
 				 */
 				if (fdtab[conn->handle.fd].ev & FD_POLL_HUP)
 					goto read0;

 				if ((!fdtab[conn->handle.fd].linger_risk) ||
 				    (cur_poller.flags & HAP_POLL_F_RDHUP)) {
 					break;
 				}
 			}
 			count -= ret;

 			if (flags & CO_RFL_READ_ONCE)
 				break;
 		}
 		else if (ret == 0) {
 			goto read0;
 		}
 		else if (errno == EAGAIN || errno == ENOTCONN) {
 			/* socket buffer exhausted */
 			fd_cant_recv(conn->handle.fd);
 			break;
 		}
 		else if (errno != EINTR) {
 			conn->flags |= CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH;
 			break;
 		}
 	}

 	if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) && done)
 		conn->flags &= ~CO_FL_WAIT_L4_CONN;

  leave:
 	return done;

  read0:
 	conn_sock_read0(conn);
 	conn->flags &= ~CO_FL_WAIT_L4_CONN;

 	/* Now a final check for a possible asynchronous low-level error
 	 * report. This can happen when a connection receives a reset
 	 * after a shutdown, both POLL_HUP and POLL_ERR are queued, and
 	 * we might have come from there by just checking POLL_HUP instead
 	 * of recv()'s return value 0, so we have no way to tell there was
 	 * an error without checking.
 	 */
 	if (unlikely(fdtab[conn->handle.fd].ev & FD_POLL_ERR))
 		conn->flags |= CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH;
 	goto leave;
 }


 /* Send up to <count> pending bytes from buffer <buf> to connection <conn>'s
  * socket. <flags> may contain some CO_SFL_* flags to hint the system about
  * other pending data for example, but this flag is ignored at the moment.
  * Only one call to send() is performed, unless the buffer wraps, in which case
  * a second call may be performed. The connection's flags are updated with
  * whatever special event is detected (error, empty). The caller is responsible
  * for taking care of those events and avoiding the call if inappropriate. The
  * function does not call the connection's polling update function, so the caller
  * is responsible for this. It's up to the caller to update the buffer's contents
  * based on the return value.
  */
 static size_t raw_sock_from_buf(struct connection *conn, void *xprt_ctx, const struct buffer *buf, size_t count, int flags)
 {
 	ssize_t ret;
 	size_t try, done;
 	int send_flag;

 	if (!conn_ctrl_ready(conn))
 		return 0;

 	if (!fd_send_ready(conn->handle.fd))
 		return 0;

 	if (conn->flags & CO_FL_SOCK_WR_SH) {
 		/* it's already closed */
 		conn->flags |= CO_FL_ERROR | CO_FL_SOCK_RD_SH;
 		errno = EPIPE;
 		return 0;
 	}

 	done = 0;
 	/* send the largest possible block. For this we perform only one call
 	 * to send() unless the buffer wraps and we exactly fill the first hunk,
 	 * in which case we accept to do it once again.
 	 */
 	while (count) {
 		try = b_contig_data(buf, done);
 		if (try > count)
 			try = count;

 		send_flag = MSG_DONTWAIT | MSG_NOSIGNAL;
 		if (try < count || flags & CO_SFL_MSG_MORE)
 			send_flag |= MSG_MORE;

 		ret = send(conn->handle.fd, b_peek(buf, done), try, send_flag);

 		if (ret > 0) {
 			count -= ret;
 			done += ret;

 			/* if the system buffer is full, don't insist */
 			if (ret < try) {
 				fd_cant_send(conn->handle.fd);
 				break;
 			}
 			if (!count)
 				fd_stop_send(conn->handle.fd);
 		}
 		else if (ret == 0 || errno == EAGAIN || errno == ENOTCONN || errno == EINPROGRESS) {
 			/* nothing written, we need to poll for write first */
 			fd_cant_send(conn->handle.fd);
 			break;
 		}
 		else if (errno != EINTR) {
 			conn->flags |= CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH;
 			break;
 		}
 	}
 	if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) && done) {
 		conn->flags &= ~CO_FL_WAIT_L4_CONN;
 	}

 	if (done > 0) {
 		/* we count the total bytes sent, and the send rate for 32-byte
 		 * blocks. The reason for the latter is that freq_ctr are
 		 * limited to 4GB and that it's not enough per second.
 		 */
 		_HA_ATOMIC_ADD(&global.out_bytes, done);
 		update_freq_ctr(&global.out_32bps, (done + 16) / 32);
 	}
 	return done;
 }

 /* Called from the upper layer, to subscribe <es> to events <event_type>. The
  * event subscriber <es> is not allowed to change from a previous call as long
  * as at least one event is still subscribed. The <event_type> must only be a
  * combination of SUB_RETRY_RECV and SUB_RETRY_SEND. It always returns 0.
  */
 static int raw_sock_subscribe(struct connection *conn, void *xprt_ctx, int event_type, struct wait_event *es)
 {
 	return conn_subscribe(conn, xprt_ctx, event_type, es);
 }

 /* Called from the upper layer, to unsubscribe <es> from events <event_type>.
  * The <es> pointer is not allowed to differ from the one passed to the
  * subscribe() call. It always returns zero.
  */
 static int raw_sock_unsubscribe(struct connection *conn, void *xprt_ctx, int event_type, struct wait_event *es)
 {
 	return conn_unsubscribe(conn, xprt_ctx, event_type, es);
 }

 /* We can't have an underlying XPRT, so just return -1 to signify failure */
 static int raw_sock_remove_xprt(struct connection *conn, void *xprt_ctx, void *toremove_ctx, const struct xprt_ops *newops, void *newctx)
 {
 	/* This is the lowest xprt we can have, so if we get there we didn't
 	 * find the xprt we wanted to remove, that's a bug
 	 */
 	BUG_ON(1);
 	return -1;
 }

 /* transport-layer operations for RAW sockets */
 static struct xprt_ops raw_sock = {
 	.snd_buf  = raw_sock_from_buf,
 	.rcv_buf  = raw_sock_to_buf,
 	.subscribe = raw_sock_subscribe,
 	.unsubscribe = raw_sock_unsubscribe,
 	.remove_xprt = raw_sock_remove_xprt,
 #if defined(USE_LINUX_SPLICE)
 	.rcv_pipe = raw_sock_to_pipe,
 	.snd_pipe = raw_sock_from_pipe,
 #endif
 	.shutr    = NULL,
 	.shutw    = NULL,
 	.close    = NULL,
 	.name     = "RAW",
 };


 __attribute__((constructor))
 static void __raw_sock_init(void)
 {
 	xprt_register(XPRT_RAW, &raw_sock);
 }

 /*
  * Local variables:
  *  c-indent-level: 8
  *  c-basic-offset: 8
  * End:
  */
	/*
	* RAW transport layer over SOCK_STREAM sockets.
	*
	* Copyright 2000-2012 Willy Tarreau <w@1wt.eu>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	*/

	#define _GNU_SOURCE
	#include <errno.h>
	#include <fcntl.h>
	#include <stdio.h>
	#include <stdlib.h>

	#include <sys/socket.h>
	#include <sys/stat.h>
	#include <sys/types.h>

	#include <netinet/tcp.h>

	#include <haproxy/api.h>
	#include <haproxy/buf.h>
	#include <haproxy/connection.h>
	#include <haproxy/global.h>
	#include <haproxy/log.h>
	#include <haproxy/stream_interface.h>
	#include <haproxy/tools.h>
	#include <haproxy/ticks.h>
	#include <haproxy/time.h>

	#include <haproxy/fd.h>
	#include <haproxy/freq_ctr.h>
	#include <haproxy/pipe.h>


	#if defined(USE_LINUX_SPLICE)

	/* A pipe contains 16 segments max, and it's common to see segments of 1448 bytes
	* because of timestamps. Use this as a hint for not looping on splice().
	*/
	#define SPLICE_FULL_HINT 16*1448

	/* how many data we attempt to splice at once when the buffer is configured for
	* infinite forwarding */
	#define MAX_SPLICE_AT_ONCE (1<<30)

	/* Returns :
	* -1 if splice() is not supported
	* >= 0 to report the amount of spliced bytes.
	* connection flags are updated (error, read0, wait_room, wait_data).
	* The caller must have previously allocated the pipe.
	*/
	int raw_sock_to_pipe(struct connection conn, void xprt_ctx, struct pipe *pipe, unsigned int count)
	{
	int ret;
	int retval = 0;


	if (!conn_ctrl_ready(conn))
	return 0;

	if (!fd_recv_ready(conn->handle.fd))
	return 0;

	conn->flags &= ~CO_FL_WAIT_ROOM;
	errno = 0;

	/* Under Linux, if FD_POLL_HUP is set, we have reached the end.
	* Since older splice() implementations were buggy and returned
	* EAGAIN on end of read, let's bypass the call to splice() now.
	*/
	if (unlikely(!(fdtab[conn->handle.fd].ev & FD_POLL_IN))) {
	/* stop here if we reached the end of data */
	if ((fdtab[conn->handle.fd].ev & (FD_POLL_ERR\|FD_POLL_HUP)) == FD_POLL_HUP)
	goto out_read0;

	/* report error on POLL_ERR before connection establishment */
	if ((fdtab[conn->handle.fd].ev & FD_POLL_ERR) && (conn->flags & CO_FL_WAIT_L4_CONN)) {
	conn->flags \|= CO_FL_ERROR \| CO_FL_SOCK_RD_SH \| CO_FL_SOCK_WR_SH;
	errno = 0; /* let the caller do a getsockopt() if it wants it */
	goto leave;
	}
	}

	while (count) {
	if (count > MAX_SPLICE_AT_ONCE)
	count = MAX_SPLICE_AT_ONCE;

	ret = splice(conn->handle.fd, NULL, pipe->prod, NULL, count,
	SPLICE_F_MOVE\|SPLICE_F_NONBLOCK);

	if (ret <= 0) {
	if (ret == 0)
	goto out_read0;

	if (errno == EAGAIN) {
	/* there are two reasons for EAGAIN :
	* - nothing in the socket buffer (standard)
	* - pipe is full
	* The difference between these two situations
	* is problematic. Since we don't know if the
	* pipe is full, we'll stop if the pipe is not
	* empty. Anyway, we will almost always fill or
	* empty the pipe.
	*/
	if (pipe->data) {
	/* always stop reading until the pipe is flushed */
	conn->flags \|= CO_FL_WAIT_ROOM;
	break;
	}
	/* socket buffer exhausted */
	fd_cant_recv(conn->handle.fd);
	break;
	}
	else if (errno == ENOSYS \|\| errno == EINVAL \|\| errno == EBADF) {
	/* splice not supported on this end, disable it.
	* We can safely return -1 since there is no
	* chance that any data has been piped yet.
	*/
	retval = -1;
	goto leave;
	}
	else if (errno == EINTR) {
	/* try again */
	continue;
	}
	/* here we have another error */
	conn->flags \|= CO_FL_ERROR;
	break;
	} /* ret <= 0 */

	retval += ret;
	pipe->data += ret;
	count -= ret;

	if (pipe->data >= SPLICE_FULL_HINT \|\| ret >= global.tune.recv_enough) {
	/* We've read enough of it for this time, let's stop before
	* being asked to poll.
	*/
	conn->flags \|= CO_FL_WAIT_ROOM;
	break;
	}
	} /* while */

	if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) && retval)
	conn->flags &= ~CO_FL_WAIT_L4_CONN;

	leave:
	if (retval > 0) {
	/* we count the total bytes sent, and the send rate for 32-byte
	* blocks. The reason for the latter is that freq_ctr are
	* limited to 4GB and that it's not enough per second.
	*/
	_HA_ATOMIC_ADD(&global.out_bytes, retval);
	update_freq_ctr(&global.out_32bps, (retval + 16) / 32);
	}
	return retval;

	out_read0:
	conn_sock_read0(conn);
	conn->flags &= ~CO_FL_WAIT_L4_CONN;
	goto leave;
	}

	/* Send as many bytes as possible from the pipe to the connection's socket.
	*/
	int raw_sock_from_pipe(struct connection conn, void xprt_ctx, struct pipe *pipe)
	{
	int ret, done;

	if (!conn_ctrl_ready(conn))
	return 0;

	if (!fd_send_ready(conn->handle.fd))
	return 0;

	if (conn->flags & CO_FL_SOCK_WR_SH) {
	/* it's already closed */
	conn->flags \|= CO_FL_ERROR \| CO_FL_SOCK_RD_SH;
	errno = EPIPE;
	return 0;
	}

	done = 0;
	while (pipe->data) {
	ret = splice(pipe->cons, NULL, conn->handle.fd, NULL, pipe->data,
	SPLICE_F_MOVE\|SPLICE_F_NONBLOCK);

	if (ret <= 0) {
	if (ret == 0 \|\| errno == EAGAIN) {
	fd_cant_send(conn->handle.fd);
	break;
	}
	else if (errno == EINTR)
	continue;

	/* here we have another error */
	conn->flags \|= CO_FL_ERROR;
	break;
	}

	done += ret;
	pipe->data -= ret;
	}
	if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) && done) {
	conn->flags &= ~CO_FL_WAIT_L4_CONN;
	}

	return done;
	}

	#endif /* USE_LINUX_SPLICE */


	/* Receive up to <count> bytes from connection <conn>'s socket and store them
	* into buffer <buf>. Only one call to recv() is performed, unless the
	* buffer wraps, in which case a second call may be performed. The connection's
	* flags are updated with whatever special event is detected (error, read0,
	* empty). The caller is responsible for taking care of those events and
	* avoiding the call if inappropriate. The function does not call the
	* connection's polling update function, so the caller is responsible for this.
	* errno is cleared before starting so that the caller knows that if it spots an
	* error without errno, it's pending and can be retrieved via getsockopt(SO_ERROR).
	*/
	static size_t raw_sock_to_buf(struct connection conn, void xprt_ctx, struct buffer *buf, size_t count, int flags)
	{
	ssize_t ret;
	size_t try, done = 0;

	if (!conn_ctrl_ready(conn))
	return 0;

	if (!fd_recv_ready(conn->handle.fd))
	return 0;

	conn->flags &= ~CO_FL_WAIT_ROOM;
	errno = 0;

	if (unlikely(!(fdtab[conn->handle.fd].ev & FD_POLL_IN))) {
	/* stop here if we reached the end of data */
	if ((fdtab[conn->handle.fd].ev & (FD_POLL_ERR\|FD_POLL_HUP)) == FD_POLL_HUP)
	goto read0;

	/* report error on POLL_ERR before connection establishment */
	if ((fdtab[conn->handle.fd].ev & FD_POLL_ERR) && (conn->flags & CO_FL_WAIT_L4_CONN)) {
	conn->flags \|= CO_FL_ERROR \| CO_FL_SOCK_RD_SH \| CO_FL_SOCK_WR_SH;
	goto leave;
	}
	}

	/* read the largest possible block. For this, we perform only one call
	* to recv() unless the buffer wraps and we exactly fill the first hunk,
	* in which case we accept to do it once again. A new attempt is made on
	* EINTR too.
	*/
	while (count > 0) {
	try = b_contig_space(buf);
	if (!try)
	break;

	if (try > count)
	try = count;

	ret = recv(conn->handle.fd, b_tail(buf), try, 0);

	if (ret > 0) {
	b_add(buf, ret);
	done += ret;
	if (ret < try) {
	/* socket buffer exhausted */
	fd_cant_recv(conn->handle.fd);

	/* unfortunately, on level-triggered events, POLL_HUP
	* is generally delivered AFTER the system buffer is
	* empty, unless the poller supports POLL_RDHUP. If
	* we know this is the case, we don't try to read more
	* as we know there's no more available. Similarly, if
	* there's no problem with lingering we don't even try
	* to read an unlikely close from the client since we'll
	* close first anyway.
	*/
	if (fdtab[conn->handle.fd].ev & FD_POLL_HUP)
	goto read0;

	if ((!fdtab[conn->handle.fd].linger_risk) \|\|
	(cur_poller.flags & HAP_POLL_F_RDHUP)) {
	break;
	}
	}
	count -= ret;

	if (flags & CO_RFL_READ_ONCE)
	break;
	}
	else if (ret == 0) {
	goto read0;
	}
	else if (errno == EAGAIN \|\| errno == ENOTCONN) {
	/* socket buffer exhausted */
	fd_cant_recv(conn->handle.fd);
	break;
	}
	else if (errno != EINTR) {
	conn->flags \|= CO_FL_ERROR \| CO_FL_SOCK_RD_SH \| CO_FL_SOCK_WR_SH;
	break;
	}
	}

	if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) && done)
	conn->flags &= ~CO_FL_WAIT_L4_CONN;

	leave:
	return done;

	read0:
	conn_sock_read0(conn);
	conn->flags &= ~CO_FL_WAIT_L4_CONN;

	/* Now a final check for a possible asynchronous low-level error
	* report. This can happen when a connection receives a reset
	* after a shutdown, both POLL_HUP and POLL_ERR are queued, and
	* we might have come from there by just checking POLL_HUP instead
	* of recv()'s return value 0, so we have no way to tell there was
	* an error without checking.
	*/
	if (unlikely(fdtab[conn->handle.fd].ev & FD_POLL_ERR))
	conn->flags \|= CO_FL_ERROR \| CO_FL_SOCK_RD_SH \| CO_FL_SOCK_WR_SH;
	goto leave;
	}


	/* Send up to <count> pending bytes from buffer <buf> to connection <conn>'s
	* socket. <flags> may contain some CO_SFL_* flags to hint the system about
	* other pending data for example, but this flag is ignored at the moment.
	* Only one call to send() is performed, unless the buffer wraps, in which case
	* a second call may be performed. The connection's flags are updated with
	* whatever special event is detected (error, empty). The caller is responsible
	* for taking care of those events and avoiding the call if inappropriate. The
	* function does not call the connection's polling update function, so the caller
	* is responsible for this. It's up to the caller to update the buffer's contents
	* based on the return value.
	*/
	static size_t raw_sock_from_buf(struct connection conn, void xprt_ctx, const struct buffer *buf, size_t count, int flags)
	{
	ssize_t ret;
	size_t try, done;
	int send_flag;

	if (!conn_ctrl_ready(conn))
	return 0;

	if (!fd_send_ready(conn->handle.fd))
	return 0;

	if (conn->flags & CO_FL_SOCK_WR_SH) {
	/* it's already closed */
	conn->flags \|= CO_FL_ERROR \| CO_FL_SOCK_RD_SH;
	errno = EPIPE;
	return 0;
	}

	done = 0;
	/* send the largest possible block. For this we perform only one call
	* to send() unless the buffer wraps and we exactly fill the first hunk,
	* in which case we accept to do it once again.
	*/
	while (count) {
	try = b_contig_data(buf, done);
	if (try > count)
	try = count;

	send_flag = MSG_DONTWAIT \| MSG_NOSIGNAL;
	if (try < count \|\| flags & CO_SFL_MSG_MORE)
	send_flag \|= MSG_MORE;

	ret = send(conn->handle.fd, b_peek(buf, done), try, send_flag);

	if (ret > 0) {
	count -= ret;
	done += ret;

	/* if the system buffer is full, don't insist */
	if (ret < try) {
	fd_cant_send(conn->handle.fd);
	break;
	}
	if (!count)
	fd_stop_send(conn->handle.fd);
	}
	else if (ret == 0 \|\| errno == EAGAIN \|\| errno == ENOTCONN \|\| errno == EINPROGRESS) {
	/* nothing written, we need to poll for write first */
	fd_cant_send(conn->handle.fd);
	break;
	}
	else if (errno != EINTR) {
	conn->flags \|= CO_FL_ERROR \| CO_FL_SOCK_RD_SH \| CO_FL_SOCK_WR_SH;
	break;
	}
	}
	if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) && done) {
	conn->flags &= ~CO_FL_WAIT_L4_CONN;
	}

	if (done > 0) {
	/* we count the total bytes sent, and the send rate for 32-byte
	* blocks. The reason for the latter is that freq_ctr are
	* limited to 4GB and that it's not enough per second.
	*/
	_HA_ATOMIC_ADD(&global.out_bytes, done);
	update_freq_ctr(&global.out_32bps, (done + 16) / 32);
	}
	return done;
	}

	/* Called from the upper layer, to subscribe <es> to events <event_type>. The
	* event subscriber <es> is not allowed to change from a previous call as long
	* as at least one event is still subscribed. The <event_type> must only be a
	* combination of SUB_RETRY_RECV and SUB_RETRY_SEND. It always returns 0.
	*/
	static int raw_sock_subscribe(struct connection conn, void xprt_ctx, int event_type, struct wait_event *es)
	{
	return conn_subscribe(conn, xprt_ctx, event_type, es);
	}

	/* Called from the upper layer, to unsubscribe <es> from events <event_type>.
	* The <es> pointer is not allowed to differ from the one passed to the
	* subscribe() call. It always returns zero.
	*/
	static int raw_sock_unsubscribe(struct connection conn, void xprt_ctx, int event_type, struct wait_event *es)
	{
	return conn_unsubscribe(conn, xprt_ctx, event_type, es);
	}

	/* We can't have an underlying XPRT, so just return -1 to signify failure */
	static int raw_sock_remove_xprt(struct connection conn, void xprt_ctx, void toremove_ctx, const struct xprt_ops newops, void *newctx)
	{
	/* This is the lowest xprt we can have, so if we get there we didn't
	* find the xprt we wanted to remove, that's a bug
	*/
	BUG_ON(1);
	return -1;
	}

	/* transport-layer operations for RAW sockets */
	static struct xprt_ops raw_sock = {
	.snd_buf = raw_sock_from_buf,
	.rcv_buf = raw_sock_to_buf,
	.subscribe = raw_sock_subscribe,
	.unsubscribe = raw_sock_unsubscribe,
	.remove_xprt = raw_sock_remove_xprt,
	#if defined(USE_LINUX_SPLICE)
	.rcv_pipe = raw_sock_to_pipe,
	.snd_pipe = raw_sock_from_pipe,
	#endif
	.shutr = NULL,
	.shutw = NULL,
	.close = NULL,
	.name = "RAW",
	};


	__attribute__((constructor))
	static void __raw_sock_init(void)
	{
	xprt_register(XPRT_RAW, &raw_sock);
	}

	/*
	* Local variables:
	* c-indent-level: 8
	* c-basic-offset: 8
	* End:
	*/