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-rw-r--r--src/raw_sock.c489
1 files changed, 489 insertions, 0 deletions
diff --git a/src/raw_sock.c b/src/raw_sock.c
new file mode 100644
index 0000000..1287dc5
--- /dev/null
+++ b/src/raw_sock.c
@@ -0,0 +1,489 @@
+/*
+ * 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/errors.h>
+#include <haproxy/fd.h>
+#include <haproxy/global.h>
+#include <haproxy/pipe.h>
+#include <haproxy/proxy.h>
+#include <haproxy/tools.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;
+
+ BUG_ON(conn->flags & CO_FL_FDLESS);
+
+ 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].state & FD_POLL_IN))) {
+ /* stop here if we reached the end of data */
+ if ((fdtab[conn->handle.fd].state & (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].state & 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 || errno == EWOULDBLOCK) {
+ /* 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)
+ increment_send_rate(retval, 1);
+
+ 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, unsigned int count)
+{
+ int ret, done;
+
+ if (!conn_ctrl_ready(conn))
+ return 0;
+
+ BUG_ON(conn->flags & CO_FL_FDLESS);
+
+ 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;
+ }
+
+ if (unlikely(count > pipe->data))
+ count = pipe->data;
+
+ done = 0;
+ while (count) {
+ ret = splice(pipe->cons, NULL, conn->handle.fd, NULL, count,
+ SPLICE_F_MOVE|SPLICE_F_NONBLOCK);
+
+ if (ret <= 0) {
+ if (ret == 0 || errno == EAGAIN || errno == EWOULDBLOCK) {
+ 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;
+ count -= 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;
+
+ BUG_ON(conn->flags & CO_FL_FDLESS);
+
+ if (!fd_recv_ready(conn->handle.fd))
+ return 0;
+
+ conn->flags &= ~CO_FL_WAIT_ROOM;
+ errno = 0;
+
+ if (unlikely(!(fdtab[conn->handle.fd].state & FD_POLL_IN))) {
+ /* stop here if we reached the end of data */
+ if ((fdtab[conn->handle.fd].state & (FD_POLL_ERR|FD_POLL_HUP)) == FD_POLL_HUP)
+ goto read0;
+
+ /* report error on POLL_ERR before connection establishment */
+ if ((fdtab[conn->handle.fd].state & 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].state & FD_POLL_HUP)
+ goto read0;
+
+ if (!(fdtab[conn->handle.fd].state & 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 == EWOULDBLOCK || 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(!done && fdtab[conn->handle.fd].state & 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;
+
+ BUG_ON(conn->flags & CO_FL_FDLESS);
+
+ if (!fd_send_ready(conn->handle.fd))
+ return 0;
+
+ if (unlikely(fdtab[conn->handle.fd].state & FD_POLL_ERR)) {
+ /* an error was reported on the FD, we can't send anymore */
+ conn->flags |= CO_FL_ERROR | CO_FL_SOCK_WR_SH | CO_FL_SOCK_RD_SH;
+ errno = EPIPE;
+ 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 == EWOULDBLOCK || 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)
+ increment_send_rate(done, 0);
+
+ 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);
+}
+
+static void raw_sock_close(struct connection *conn, void *xprt_ctx)
+{
+ if (conn->subs != NULL) {
+ conn_unsubscribe(conn, NULL, conn->subs->events, conn->subs);
+ }
+}
+
+/* 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 = raw_sock_close,
+ .name = "RAW",
+};
+
+
+static void __raw_sock_init(void)
+{
+ xprt_register(XPRT_RAW, &raw_sock);
+}
+
+INITCALL0(STG_REGISTER, __raw_sock_init);
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ */
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