1 files changed, 447 insertions, 0 deletions
diff --git a/include/haproxy/sc_strm.h b/include/haproxy/sc_strm.h
new file mode 100644
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+++ b/include/haproxy/sc_strm.h
@@ -0,0 +1,447 @@
+/*
+ * include/haproxy/sc_strm.h
+ * This file contains stream-specific stream-connector functions prototypes
+ *
+ * Copyright 2022 Christopher Faulet <cfaulet@haproxy.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef _HAPROXY_SC_STRM_H
+#define _HAPROXY_SC_STRM_H
+
+#include <haproxy/api.h>
+#include <haproxy/buf-t.h>
+#include <haproxy/channel-t.h>
+#include <haproxy/stream-t.h>
+#include <haproxy/task-t.h>
+#include <haproxy/connection.h>
+#include <haproxy/channel.h>
+#include <haproxy/session.h>
+#include <haproxy/stconn.h>
+#include <haproxy/stream.h>
+
+void sc_update_rx(struct stconn *sc);
+void sc_update_tx(struct stconn *sc);
+
+struct task *sc_conn_io_cb(struct task *t, void *ctx, unsigned int state);
+int sc_conn_sync_recv(struct stconn *sc);
+void sc_conn_sync_send(struct stconn *sc);
+
+
+/* returns the channel which receives data from this stream connector (input channel) */
+static inline struct channel *sc_ic(const struct stconn *sc)
+{
+	struct stream *strm = __sc_strm(sc);
+
+	return ((sc->flags & SC_FL_ISBACK) ? &(strm->res) : &(strm->req));
+}
+
+/* returns the channel which feeds data to this stream connector (output channel) */
+static inline struct channel *sc_oc(const struct stconn *sc)
+{
+	struct stream *strm = __sc_strm(sc);
+
+	return ((sc->flags & SC_FL_ISBACK) ? &(strm->req) : &(strm->res));
+}
+
+/* returns the buffer which receives data from this stream connector (input channel's buffer) */
+static inline struct buffer *sc_ib(const struct stconn *sc)
+{
+	return &sc_ic(sc)->buf;
+}
+
+/* returns the buffer which feeds data to this stream connector (output channel's buffer) */
+static inline struct buffer *sc_ob(const struct stconn *sc)
+{
+	return &sc_oc(sc)->buf;
+}
+/* returns the stream's task associated to this stream connector */
+static inline struct task *sc_strm_task(const struct stconn *sc)
+{
+	struct stream *strm = __sc_strm(sc);
+
+	return strm->task;
+}
+
+/* returns the stream connector on the other side. Used during forwarding. */
+static inline struct stconn *sc_opposite(const struct stconn *sc)
+{
+	struct stream *strm = __sc_strm(sc);
+
+	return ((sc->flags & SC_FL_ISBACK) ? strm->scf : strm->scb);
+}
+
+
+/* sets the current and previous state of a stream connector to <state>. This is
+ * mainly used to create one in the established state on incoming connections.
+ */
+static inline void sc_set_state(struct stconn *sc, int state)
+{
+	sc->state = __sc_strm(sc)->prev_conn_state = state;
+}
+
+/* returns a bit for a stream connector state, to match against SC_SB_* */
+static inline enum sc_state_bit sc_state_bit(enum sc_state state)
+{
+	BUG_ON(state > SC_ST_CLO);
+	return 1U << state;
+}
+
+/* returns true if <state> matches one of the SC_SB_* bits in <mask> */
+static inline int sc_state_in(enum sc_state state, enum sc_state_bit mask)
+{
+	BUG_ON(mask & ~SC_SB_ALL);
+	return !!(sc_state_bit(state) & mask);
+}
+
+/* Returns true if a connection is attached to the stream connector <sc> and if this
+ * connection is ready.
+ */
+static inline int sc_conn_ready(const struct stconn *sc)
+{
+	const struct connection *conn = sc_conn(sc);
+
+	return conn && conn_ctrl_ready(conn) && conn_xprt_ready(conn);
+}
+
+
+/* The stream connector is only responsible for the connection during the early
+ * states, before plugging a mux. Thus it should only care about CO_FL_ERROR
+ * before SC_ST_EST, and after that it must absolutely ignore it since the mux
+ * may hold pending data. This function returns true if such an error was
+ * reported. Both the SC and the CONN must be valid.
+ */
+static inline int sc_is_conn_error(const struct stconn *sc)
+{
+	const struct connection *conn;
+
+	if (sc->state >= SC_ST_EST)
+		return 0;
+
+	conn = __sc_conn(sc);
+	BUG_ON(!conn);
+	return !!(conn->flags & CO_FL_ERROR);
+}
+
+/* Try to allocate a buffer for the stream connector's input channel. It relies on
+ * channel_alloc_buffer() for this so it abides by its rules. It returns 0 on
+ * failure, non-zero otherwise. If no buffer is available, the requester,
+ * represented by the <wait> pointer, will be added in the list of objects
+ * waiting for an available buffer, and SC_FL_NEED_BUFF will be set on the
+ * stream connector and SE_FL_HAVE_NO_DATA cleared. The requester will be responsible
+ * for calling this function to try again once woken up.
+ */
+static inline int sc_alloc_ibuf(struct stconn *sc, struct buffer_wait *wait)
+{
+	int ret;
+
+	ret = channel_alloc_buffer(sc_ic(sc), wait);
+	if (!ret)
+		sc_need_buff(sc);
+	return ret;
+}
+
+
+/* Returns the source address of the stream connector and, if not set, fallbacks on
+ * the session for frontend SC and the server connection for the backend SC. It
+ * returns a const address on success or NULL on failure.
+ */
+static inline const struct sockaddr_storage *sc_src(const struct stconn *sc)
+{
+	if (sc->src)
+		return sc->src;
+	if (!(sc->flags & SC_FL_ISBACK))
+		return sess_src(strm_sess(__sc_strm(sc)));
+	else {
+		struct connection *conn = sc_conn(sc);
+
+		if (conn)
+			return conn_src(conn);
+	}
+	return NULL;
+}
+
+
+/* Returns the destination address of the stream connector and, if not set, fallbacks
+ * on the session for frontend SC and the server connection for the backend
+ * SC. It returns a const address on success or NULL on failure.
+ */
+static inline const struct sockaddr_storage *sc_dst(const struct stconn *sc)
+{
+	if (sc->dst)
+		return sc->dst;
+	if (!(sc->flags & SC_FL_ISBACK))
+		return sess_dst(strm_sess(__sc_strm(sc)));
+	else {
+		struct connection *conn = sc_conn(sc);
+
+		if (conn)
+			return conn_dst(conn);
+	}
+	return NULL;
+}
+
+/* Retrieves the source address of the stream connector. Returns non-zero on success
+ * or zero on failure. The operation is only performed once and the address is
+ * stored in the stream connector for future use. On the first call, the stream connector
+ * source address is copied from the session one for frontend SC and the server
+ * connection for the backend SC.
+ */
+static inline int sc_get_src(struct stconn *sc)
+{
+	const struct sockaddr_storage *src = NULL;
+
+	if (sc->src)
+		return 1;
+
+	if (!(sc->flags & SC_FL_ISBACK))
+		src = sess_src(strm_sess(__sc_strm(sc)));
+	else {
+		struct connection *conn = sc_conn(sc);
+
+		if (conn)
+			src = conn_src(conn);
+	}
+	if (!src)
+		return 0;
+
+	if (!sockaddr_alloc(&sc->src, src, sizeof(*src)))
+		return 0;
+
+	return 1;
+}
+
+/* Retrieves the destination address of the stream connector. Returns non-zero on
+ * success or zero on failure. The operation is only performed once and the
+ * address is stored in the stream connector for future use. On the first call, the
+ * stream connector destination address is copied from the session one for frontend
+ * SC and the server connection for the backend SC.
+ */
+static inline int sc_get_dst(struct stconn *sc)
+{
+	const struct sockaddr_storage *dst = NULL;
+
+	if (sc->dst)
+		return 1;
+
+	if (!(sc->flags & SC_FL_ISBACK))
+		dst = sess_dst(strm_sess(__sc_strm(sc)));
+	else {
+		struct connection *conn = sc_conn(sc);
+
+		if (conn)
+			dst = conn_dst(conn);
+	}
+	if (!dst)
+		return 0;
+
+	if (!sockaddr_alloc(&sc->dst, dst, sizeof(*dst)))
+		return 0;
+
+	return 1;
+}
+
+
+/* Marks on the stream connector that next shutdown must kill the whole connection */
+static inline void sc_must_kill_conn(struct stconn *sc)
+{
+	sc_ep_set(sc, SE_FL_KILL_CONN);
+}
+
+
+/* Returns non-zero if the stream connector is allowed to receive from the
+ * endpoint, which means that no flag indicating a blocked channel, lack of
+ * buffer or room is set, and that the endpoint is not waiting for the
+ * application to complete a connection setup on the other side, and that
+ * the stream's channel is not shut for reads. This is only used by stream
+ * applications.
+ */
+__attribute__((warn_unused_result))
+static inline int sc_is_recv_allowed(const struct stconn *sc)
+{
+	if (sc->flags & (SC_FL_ABRT_DONE|SC_FL_EOS))
+		return 0;
+
+	if (sc_ep_test(sc, SE_FL_APPLET_NEED_CONN))
+		return 0;
+
+	if (sc_ep_test(sc, SE_FL_HAVE_NO_DATA))
+		return 0;
+
+	if (sc_ep_test(sc, SE_FL_MAY_FASTFWD_PROD) && (sc_opposite(sc)->sedesc->iobuf.flags & IOBUF_FL_FF_BLOCKED))
+		return 0;
+
+	return !(sc->flags & (SC_FL_WONT_READ|SC_FL_NEED_BUFF|SC_FL_NEED_ROOM));
+}
+
+/* This is to be used after making some room available in a channel. It will
+ * return without doing anything if the stream connector's RX path is blocked.
+ * It will automatically mark the stream connector as busy processing the end
+ * point in order to avoid useless repeated wakeups.
+ * It will then call ->chk_rcv() to enable receipt of new data.
+ */
+static inline void sc_chk_rcv(struct stconn *sc)
+{
+	if (sc_ep_test(sc, SE_FL_APPLET_NEED_CONN) &&
+	    sc_state_in(sc_opposite(sc)->state, SC_SB_RDY|SC_SB_EST|SC_SB_DIS|SC_SB_CLO)) {
+		sc_ep_clr(sc, SE_FL_APPLET_NEED_CONN);
+		sc_ep_report_read_activity(sc);
+	}
+
+	if (!sc_is_recv_allowed(sc))
+		return;
+
+	if (!sc_state_in(sc->state, SC_SB_RDY|SC_SB_EST))
+		return;
+
+	sc_ep_set(sc, SE_FL_HAVE_NO_DATA);
+	if (likely(sc->app_ops->chk_rcv))
+		sc->app_ops->chk_rcv(sc);
+}
+
+/* Calls chk_snd on the endpoint using the data layer */
+static inline void sc_chk_snd(struct stconn *sc)
+{
+	if (likely(sc->app_ops->chk_snd))
+		sc->app_ops->chk_snd(sc);
+}
+
+/* Combines both sc_update_rx() and sc_update_tx() at once */
+static inline void sc_update(struct stconn *sc)
+{
+	sc_update_rx(sc);
+	sc_update_tx(sc);
+}
+
+/* for debugging, reports the stream connector state name */
+static inline const char *sc_state_str(int state)
+{
+	switch (state) {
+	case SC_ST_INI: return "INI";
+	case SC_ST_REQ: return "REQ";
+	case SC_ST_QUE: return "QUE";
+	case SC_ST_TAR: return "TAR";
+	case SC_ST_ASS: return "ASS";
+	case SC_ST_CON: return "CON";
+	case SC_ST_CER: return "CER";
+	case SC_ST_RDY: return "RDY";
+	case SC_ST_EST: return "EST";
+	case SC_ST_DIS: return "DIS";
+	case SC_ST_CLO: return "CLO";
+	default:        return "???";
+	}
+}
+
+/* indicates if the connector may send data to the endpoint, that is, the
+ * endpoint is both willing to receive data and ready to do so. This is only
+ * used with applets so there's always a stream attached to this connector.
+ */
+__attribute__((warn_unused_result))
+static inline int sc_is_send_allowed(const struct stconn *sc)
+{
+	if (sc->flags & SC_FL_SHUT_DONE)
+		return 0;
+
+	return !sc_ep_test(sc, SE_FL_WAIT_DATA | SE_FL_WONT_CONSUME);
+}
+
+static inline int sc_rcv_may_expire(const struct stconn *sc)
+{
+	if ((sc->flags & (SC_FL_ABRT_DONE|SC_FL_EOS)) || (sc_ic(sc)->flags & CF_READ_TIMEOUT))
+		return 0;
+	if (sc->flags & (SC_FL_EOI|SC_FL_WONT_READ|SC_FL_NEED_BUFF|SC_FL_NEED_ROOM))
+		return 0;
+	if (sc_ep_test(sc, SE_FL_APPLET_NEED_CONN) || sc_ep_test(sc_opposite(sc), SE_FL_EXP_NO_DATA))
+		return 0;
+	return 1;
+}
+
+static inline int sc_snd_may_expire(const struct stconn *sc)
+{
+	if ((sc->flags & SC_FL_SHUT_DONE) || (sc_oc(sc)->flags & CF_WRITE_TIMEOUT))
+		return 0;
+	if (sc_ep_test(sc, SE_FL_WONT_CONSUME))
+		return 0;
+	return 1;
+}
+
+static forceinline int sc_ep_rcv_ex(const struct stconn *sc)
+{
+	return ((tick_isset(sc->sedesc->lra) && sc_rcv_may_expire(sc))
+		? tick_add_ifset(sc->sedesc->lra, sc->ioto)
+		: TICK_ETERNITY);
+}
+
+static forceinline int sc_ep_snd_ex(const struct stconn *sc)
+{
+	return ((tick_isset(sc->sedesc->fsb) && sc_snd_may_expire(sc))
+		? tick_add_ifset(sc->sedesc->fsb, sc->ioto)
+		: TICK_ETERNITY);
+}
+
+static inline void sc_check_timeouts(const struct stconn *sc)
+{
+	if (unlikely(tick_is_expired(sc_ep_rcv_ex(sc), now_ms)))
+		sc_ic(sc)->flags |= CF_READ_TIMEOUT;
+	if (unlikely(tick_is_expired(sc_ep_snd_ex(sc), now_ms)))
+		sc_oc(sc)->flags |= CF_WRITE_TIMEOUT;
+}
+
+static inline void sc_set_hcto(struct stconn *sc)
+{
+	struct stream *strm = __sc_strm(sc);
+
+	if (IS_HTX_STRM(strm))
+		return;
+
+	if (sc->flags & SC_FL_ISBACK) {
+		if ((strm->flags & SF_BE_ASSIGNED) && tick_isset(strm->be->timeout.serverfin))
+			sc->ioto = strm->be->timeout.serverfin;
+	}
+	else {
+		if (tick_isset(strm_fe(strm)->timeout.clientfin))
+			sc->ioto = strm_fe(strm)->timeout.clientfin;
+	}
+
+}
+
+/* Schedule an abort for the SC */
+static inline void sc_schedule_abort(struct stconn *sc)
+{
+	sc->flags |= SC_FL_ABRT_WANTED;
+}
+
+/* Abort the SC and notify the endpoint using the data layer */
+static inline void sc_abort(struct stconn *sc)
+{
+	if (likely(sc->app_ops->abort))
+		sc->app_ops->abort(sc);
+}
+
+/* Schedule a shutdown for the SC */
+static inline void sc_schedule_shutdown(struct stconn *sc)
+{
+	sc->flags |= SC_FL_SHUT_WANTED;
+}
+
+/* Shutdown the SC and notify the endpoint using the data layer */
+static inline void sc_shutdown(struct stconn *sc)
+{
+	if (likely(sc->app_ops->shutdown))
+		sc->app_ops->shutdown(sc);
+}
+
+#endif /* _HAPROXY_SC_STRM_H */