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-rw-r--r--src/stconn.c2012
1 files changed, 2012 insertions, 0 deletions
diff --git a/src/stconn.c b/src/stconn.c
new file mode 100644
index 0000000..e6436a9
--- /dev/null
+++ b/src/stconn.c
@@ -0,0 +1,2012 @@
+/*
+ * stream connector management functions
+ *
+ * Copyright 2021 Christopher Faulet <cfaulet@haproxy.com>
+ *
+ * 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.
+ *
+ */
+
+#include <haproxy/api.h>
+#include <haproxy/applet.h>
+#include <haproxy/connection.h>
+#include <haproxy/check.h>
+#include <haproxy/http_ana.h>
+#include <haproxy/pipe.h>
+#include <haproxy/pool.h>
+#include <haproxy/sc_strm.h>
+#include <haproxy/stconn.h>
+
+DECLARE_POOL(pool_head_connstream, "stconn", sizeof(struct stconn));
+DECLARE_POOL(pool_head_sedesc, "sedesc", sizeof(struct sedesc));
+
+/* functions used by default on a detached stream connector */
+static void sc_app_shutr(struct stconn *sc);
+static void sc_app_shutw(struct stconn *sc);
+static void sc_app_chk_rcv(struct stconn *sc);
+static void sc_app_chk_snd(struct stconn *sc);
+
+/* functions used on a mux-based stream connector */
+static void sc_app_shutr_conn(struct stconn *sc);
+static void sc_app_shutw_conn(struct stconn *sc);
+static void sc_app_chk_rcv_conn(struct stconn *sc);
+static void sc_app_chk_snd_conn(struct stconn *sc);
+
+/* functions used on an applet-based stream connector */
+static void sc_app_shutr_applet(struct stconn *sc);
+static void sc_app_shutw_applet(struct stconn *sc);
+static void sc_app_chk_rcv_applet(struct stconn *sc);
+static void sc_app_chk_snd_applet(struct stconn *sc);
+
+static int sc_conn_process(struct stconn *sc);
+static int sc_conn_recv(struct stconn *sc);
+static int sc_conn_send(struct stconn *sc);
+static int sc_applet_process(struct stconn *sc);
+
+/* stream connector operations for connections */
+struct sc_app_ops sc_app_conn_ops = {
+ .chk_rcv = sc_app_chk_rcv_conn,
+ .chk_snd = sc_app_chk_snd_conn,
+ .shutr = sc_app_shutr_conn,
+ .shutw = sc_app_shutw_conn,
+ .wake = sc_conn_process,
+ .name = "STRM",
+};
+
+/* stream connector operations for embedded tasks */
+struct sc_app_ops sc_app_embedded_ops = {
+ .chk_rcv = sc_app_chk_rcv,
+ .chk_snd = sc_app_chk_snd,
+ .shutr = sc_app_shutr,
+ .shutw = sc_app_shutw,
+ .wake = NULL, /* may never be used */
+ .name = "NONE", /* may never be used */
+};
+
+/* stream connector operations for applets */
+struct sc_app_ops sc_app_applet_ops = {
+ .chk_rcv = sc_app_chk_rcv_applet,
+ .chk_snd = sc_app_chk_snd_applet,
+ .shutr = sc_app_shutr_applet,
+ .shutw = sc_app_shutw_applet,
+ .wake = sc_applet_process,
+ .name = "STRM",
+};
+
+/* stream connector for health checks on connections */
+struct sc_app_ops sc_app_check_ops = {
+ .chk_rcv = NULL,
+ .chk_snd = NULL,
+ .shutr = NULL,
+ .shutw = NULL,
+ .wake = wake_srv_chk,
+ .name = "CHCK",
+};
+
+/* Initializes an endpoint */
+void sedesc_init(struct sedesc *sedesc)
+{
+ sedesc->se = NULL;
+ sedesc->conn = NULL;
+ sedesc->sc = NULL;
+ se_fl_setall(sedesc, SE_FL_NONE);
+}
+
+/* Tries to alloc an endpoint and initialize it. Returns NULL on failure. */
+struct sedesc *sedesc_new()
+{
+ struct sedesc *sedesc;
+
+ sedesc = pool_alloc(pool_head_sedesc);
+ if (unlikely(!sedesc))
+ return NULL;
+
+ sedesc_init(sedesc);
+ return sedesc;
+}
+
+/* Releases an endpoint. It is the caller responsibility to be sure it is safe
+ * and it is not shared with another entity
+ */
+void sedesc_free(struct sedesc *sedesc)
+{
+ pool_free(pool_head_sedesc, sedesc);
+}
+
+/* Tries to allocate a new stconn and initialize its main fields. On
+ * failure, nothing is allocated and NULL is returned. It is an internal
+ * function. The caller must, at least, set the SE_FL_ORPHAN or SE_FL_DETACHED
+ * flag.
+ */
+static struct stconn *sc_new(struct sedesc *sedesc)
+{
+ struct stconn *sc;
+
+ sc = pool_alloc(pool_head_connstream);
+
+ if (unlikely(!sc))
+ goto alloc_error;
+
+ sc->obj_type = OBJ_TYPE_SC;
+ sc->flags = SC_FL_NONE;
+ sc->state = SC_ST_INI;
+ sc->hcto = TICK_ETERNITY;
+ sc->app = NULL;
+ sc->app_ops = NULL;
+ sc->src = NULL;
+ sc->dst = NULL;
+ sc->wait_event.tasklet = NULL;
+ sc->wait_event.events = 0;
+
+ /* If there is no endpoint, allocate a new one now */
+ if (!sedesc) {
+ sedesc = sedesc_new();
+ if (unlikely(!sedesc))
+ goto alloc_error;
+ }
+ sc->sedesc = sedesc;
+ sedesc->sc = sc;
+
+ return sc;
+
+ alloc_error:
+ pool_free(pool_head_connstream, sc);
+ return NULL;
+}
+
+/* Creates a new stream connector and its associated stream from a mux. <sd> must
+ * be defined. It returns NULL on error. On success, the new stream connector is
+ * returned. In this case, SE_FL_ORPHAN flag is removed.
+ */
+struct stconn *sc_new_from_endp(struct sedesc *sd, struct session *sess, struct buffer *input)
+{
+ struct stconn *sc;
+
+ sc = sc_new(sd);
+ if (unlikely(!sc))
+ return NULL;
+ if (unlikely(!stream_new(sess, sc, input))) {
+ sd->sc = NULL;
+ if (sc->sedesc != sd) {
+ /* none was provided so sc_new() allocated one */
+ sedesc_free(sc->sedesc);
+ }
+ pool_free(pool_head_connstream, sc);
+ se_fl_set(sd, SE_FL_ORPHAN);
+ return NULL;
+ }
+ se_fl_clr(sd, SE_FL_ORPHAN);
+ return sc;
+}
+
+/* Creates a new stream connector from an stream. There is no endpoint here, thus it
+ * will be created by sc_new(). So the SE_FL_DETACHED flag is set. It returns
+ * NULL on error. On success, the new stream connector is returned.
+ */
+struct stconn *sc_new_from_strm(struct stream *strm, unsigned int flags)
+{
+ struct stconn *sc;
+
+ sc = sc_new(NULL);
+ if (unlikely(!sc))
+ return NULL;
+ sc->flags |= flags;
+ sc_ep_set(sc, SE_FL_DETACHED);
+ sc->app = &strm->obj_type;
+ sc->app_ops = &sc_app_embedded_ops;
+ return sc;
+}
+
+/* Creates a new stream connector from an health-check. There is no endpoint here,
+ * thus it will be created by sc_new(). So the SE_FL_DETACHED flag is set. It
+ * returns NULL on error. On success, the new stream connector is returned.
+ */
+struct stconn *sc_new_from_check(struct check *check, unsigned int flags)
+{
+ struct stconn *sc;
+
+ sc = sc_new(NULL);
+ if (unlikely(!sc))
+ return NULL;
+ sc->flags |= flags;
+ sc_ep_set(sc, SE_FL_DETACHED);
+ sc->app = &check->obj_type;
+ sc->app_ops = &sc_app_check_ops;
+ return sc;
+}
+
+/* Releases a stconn previously allocated by sc_new(), as well as its
+ * endpoint, if it exists. This function is called internally or on error path.
+ */
+void sc_free(struct stconn *sc)
+{
+ sockaddr_free(&sc->src);
+ sockaddr_free(&sc->dst);
+ if (sc->sedesc) {
+ BUG_ON(!sc_ep_test(sc, SE_FL_DETACHED));
+ sedesc_free(sc->sedesc);
+ }
+ if (sc->wait_event.tasklet)
+ tasklet_free(sc->wait_event.tasklet);
+ pool_free(pool_head_connstream, sc);
+}
+
+/* Conditionally removes a stream connector if it is detached and if there is no app
+ * layer defined. Except on error path, this one must be used. if release, the
+ * pointer on the SC is set to NULL.
+ */
+static void sc_free_cond(struct stconn **scp)
+{
+ struct stconn *sc = *scp;
+
+ if (!sc->app && (!sc->sedesc || sc_ep_test(sc, SE_FL_DETACHED))) {
+ sc_free(sc);
+ *scp = NULL;
+ }
+}
+
+
+/* Attaches a stconn to a mux endpoint and sets the endpoint ctx. Returns
+ * -1 on error and 0 on success. SE_FL_DETACHED flag is removed. This function is
+ * called from a mux when it is attached to a stream or a health-check.
+ */
+int sc_attach_mux(struct stconn *sc, void *sd, void *ctx)
+{
+ struct connection *conn = ctx;
+ struct sedesc *sedesc = sc->sedesc;
+
+ if (sc_strm(sc)) {
+ if (!sc->wait_event.tasklet) {
+ sc->wait_event.tasklet = tasklet_new();
+ if (!sc->wait_event.tasklet)
+ return -1;
+ sc->wait_event.tasklet->process = sc_conn_io_cb;
+ sc->wait_event.tasklet->context = sc;
+ sc->wait_event.events = 0;
+ }
+
+ sc->app_ops = &sc_app_conn_ops;
+ }
+ else if (sc_check(sc)) {
+ if (!sc->wait_event.tasklet) {
+ sc->wait_event.tasklet = tasklet_new();
+ if (!sc->wait_event.tasklet)
+ return -1;
+ sc->wait_event.tasklet->process = srv_chk_io_cb;
+ sc->wait_event.tasklet->context = sc;
+ sc->wait_event.events = 0;
+ }
+
+ sc->app_ops = &sc_app_check_ops;
+ }
+
+ sedesc->se = sd;
+ sedesc->conn = ctx;
+ se_fl_set(sedesc, SE_FL_T_MUX);
+ se_fl_clr(sedesc, SE_FL_DETACHED);
+ if (!conn->ctx)
+ conn->ctx = sc;
+ return 0;
+}
+
+/* Attaches a stconn to an applet endpoint and sets the endpoint
+ * ctx. Returns -1 on error and 0 on success. SE_FL_DETACHED flag is
+ * removed. This function is called by a stream when a backend applet is
+ * registered.
+ */
+static void sc_attach_applet(struct stconn *sc, void *sd)
+{
+ sc->sedesc->se = sd;
+ sc_ep_set(sc, SE_FL_T_APPLET);
+ sc_ep_clr(sc, SE_FL_DETACHED);
+ if (sc_strm(sc))
+ sc->app_ops = &sc_app_applet_ops;
+}
+
+/* Attaches a stconn to a app layer and sets the relevant
+ * callbacks. Returns -1 on error and 0 on success. SE_FL_ORPHAN flag is
+ * removed. This function is called by a stream when it is created to attach it
+ * on the stream connector on the client side.
+ */
+int sc_attach_strm(struct stconn *sc, struct stream *strm)
+{
+ sc->app = &strm->obj_type;
+ sc_ep_clr(sc, SE_FL_ORPHAN);
+ if (sc_ep_test(sc, SE_FL_T_MUX)) {
+ sc->wait_event.tasklet = tasklet_new();
+ if (!sc->wait_event.tasklet)
+ return -1;
+ sc->wait_event.tasklet->process = sc_conn_io_cb;
+ sc->wait_event.tasklet->context = sc;
+ sc->wait_event.events = 0;
+
+ sc->app_ops = &sc_app_conn_ops;
+ }
+ else if (sc_ep_test(sc, SE_FL_T_APPLET)) {
+ sc->app_ops = &sc_app_applet_ops;
+ }
+ else {
+ sc->app_ops = &sc_app_embedded_ops;
+ }
+ return 0;
+}
+
+/* Detaches the stconn from the endpoint, if any. For a connecrion, if a
+ * mux owns the connection ->detach() callback is called. Otherwise, it means
+ * the stream connector owns the connection. In this case the connection is closed
+ * and released. For an applet, the appctx is released. If still allocated, the
+ * endpoint is reset and flag as detached. If the app layer is also detached,
+ * the stream connector is released.
+ */
+static void sc_detach_endp(struct stconn **scp)
+{
+ struct stconn *sc = *scp;
+
+ if (!sc)
+ return;
+
+ if (!sc->sedesc)
+ goto reset_cs;
+
+ if (sc_ep_test(sc, SE_FL_T_MUX)) {
+ struct connection *conn = __sc_conn(sc);
+ struct sedesc *sedesc = sc->sedesc;
+
+ if (conn->mux) {
+ if (sc->wait_event.events != 0)
+ conn->mux->unsubscribe(sc, sc->wait_event.events, &sc->wait_event);
+ se_fl_set(sedesc, SE_FL_ORPHAN);
+ sedesc->sc = NULL;
+ sc->sedesc = NULL;
+ conn->mux->detach(sedesc);
+ }
+ else {
+ /* It's too early to have a mux, let's just destroy
+ * the connection
+ */
+ conn_stop_tracking(conn);
+ conn_full_close(conn);
+ if (conn->destroy_cb)
+ conn->destroy_cb(conn);
+ conn_free(conn);
+ }
+ }
+ else if (sc_ep_test(sc, SE_FL_T_APPLET)) {
+ struct appctx *appctx = __sc_appctx(sc);
+
+ sc_ep_set(sc, SE_FL_ORPHAN);
+ sc->sedesc->sc = NULL;
+ sc->sedesc = NULL;
+ appctx_shut(appctx);
+ appctx_free(appctx);
+ }
+
+ if (sc->sedesc) {
+ /* the SD wasn't used and can be recycled */
+ sc->sedesc->se = NULL;
+ sc->sedesc->conn = NULL;
+ sc->sedesc->flags = 0;
+ sc_ep_set(sc, SE_FL_DETACHED);
+ }
+
+ reset_cs:
+ /* FIXME: Rest SC for now but must be reviewed. SC flags are only
+ * connection related for now but this will evolved
+ */
+ sc->flags &= SC_FL_ISBACK;
+ if (sc_strm(sc))
+ sc->app_ops = &sc_app_embedded_ops;
+ else
+ sc->app_ops = NULL;
+ sc_free_cond(scp);
+}
+
+/* Detaches the stconn from the app layer. If there is no endpoint attached
+ * to the stconn
+ */
+static void sc_detach_app(struct stconn **scp)
+{
+ struct stconn *sc = *scp;
+
+ if (!sc)
+ return;
+
+ sc->app = NULL;
+ sc->app_ops = NULL;
+ sockaddr_free(&sc->src);
+ sockaddr_free(&sc->dst);
+
+ if (sc->wait_event.tasklet)
+ tasklet_free(sc->wait_event.tasklet);
+ sc->wait_event.tasklet = NULL;
+ sc->wait_event.events = 0;
+ sc_free_cond(scp);
+}
+
+/* Destroy the stconn. It is detached from its endpoint and its
+ * application. After this call, the stconn must be considered as released.
+ */
+void sc_destroy(struct stconn *sc)
+{
+ sc_detach_endp(&sc);
+ sc_detach_app(&sc);
+ BUG_ON_HOT(sc);
+}
+
+/* Resets the stream connector endpoint. It happens when the app layer want to renew
+ * its endpoint. For a connection retry for instance. If a mux or an applet is
+ * attached, a new endpoint is created. Returns -1 on error and 0 on success.
+ *
+ * Only SE_FL_ERROR flag is removed on the endpoint. Orther flags are preserved.
+ * It is the caller responsibility to remove other flags if needed.
+ */
+int sc_reset_endp(struct stconn *sc)
+{
+ struct sedesc *new_sd;
+
+ BUG_ON(!sc->app);
+
+ sc_ep_clr(sc, SE_FL_ERROR);
+ if (!__sc_endp(sc)) {
+ /* endpoint not attached or attached to a mux with no
+ * target. Thus the endpoint will not be release but just
+ * reset. The app is still attached, the sc will not be
+ * released.
+ */
+ sc_detach_endp(&sc);
+ return 0;
+ }
+
+ /* allocate the new endpoint first to be able to set error if it
+ * fails */
+ new_sd = sedesc_new();
+ if (!unlikely(new_sd)) {
+ sc_ep_set(sc, SE_FL_ERROR);
+ return -1;
+ }
+
+ /* The app is still attached, the sc will not be released */
+ sc_detach_endp(&sc);
+ BUG_ON(!sc);
+ BUG_ON(sc->sedesc);
+ sc->sedesc = new_sd;
+ sc->sedesc->sc = sc;
+ sc_ep_set(sc, SE_FL_DETACHED);
+ return 0;
+}
+
+
+/* Create an applet to handle a stream connector as a new appctx. The SC will
+ * wake it up every time it is solicited. The appctx must be deleted by the task
+ * handler using sc_detach_endp(), possibly from within the function itself.
+ * It also pre-initializes the applet's context and returns it (or NULL in case
+ * it could not be allocated).
+ */
+struct appctx *sc_applet_create(struct stconn *sc, struct applet *app)
+{
+ struct appctx *appctx;
+
+ DPRINTF(stderr, "registering handler %p for sc %p (was %p)\n", app, sc, sc_strm_task(sc));
+
+ appctx = appctx_new_here(app, sc->sedesc);
+ if (!appctx)
+ return NULL;
+ sc_attach_applet(sc, appctx);
+ appctx->t->nice = __sc_strm(sc)->task->nice;
+ applet_need_more_data(appctx);
+ appctx_wakeup(appctx);
+
+ sc->state = SC_ST_RDY;
+ return appctx;
+}
+
+/* Conditionnaly forward the close to the wirte side. It return 1 if it can be
+ * forwarded. It is the caller responsibility to forward the close to the write
+ * side. Otherwise, 0 is returned. In this case, CF_SHUTW_NOW flag may be set on
+ * the channel if we are only waiting for the outgoing data to be flushed.
+ */
+static inline int sc_cond_forward_shutw(struct stconn *sc)
+{
+ /* The close must not be forwarded */
+ if (!(sc_ic(sc)->flags & CF_SHUTR) || !(sc->flags & SC_FL_NOHALF))
+ return 0;
+
+ if (!channel_is_empty(sc_ic(sc))) {
+ /* the close to the write side cannot be forwarded now because
+ * we should flush outgoing data first. But instruct the output
+ * channel it should be done ASAP.
+ */
+ channel_shutw_now(sc_oc(sc));
+ return 0;
+ }
+
+ /* the close can be immediately forwarded to the write side */
+ return 1;
+}
+
+/*
+ * This function performs a shutdown-read on a detached stream connector in a
+ * connected or init state (it does nothing for other states). It either shuts
+ * the read side or marks itself as closed. The buffer flags are updated to
+ * reflect the new state. If the stream connector has SC_FL_NOHALF, we also
+ * forward the close to the write side. The owner task is woken up if it exists.
+ */
+static void sc_app_shutr(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+
+ if (ic->flags & CF_SHUTR)
+ return;
+ ic->flags |= CF_SHUTR;
+ ic->rex = TICK_ETERNITY;
+
+ if (!sc_state_in(sc->state, SC_SB_CON|SC_SB_RDY|SC_SB_EST))
+ return;
+
+ if (sc_oc(sc)->flags & CF_SHUTW) {
+ sc->state = SC_ST_DIS;
+ if (sc->flags & SC_FL_ISBACK)
+ __sc_strm(sc)->conn_exp = TICK_ETERNITY;
+ }
+ else if (sc_cond_forward_shutw(sc))
+ return sc_app_shutw(sc);
+
+ /* note that if the task exists, it must unregister itself once it runs */
+ if (!(sc->flags & SC_FL_DONT_WAKE))
+ task_wakeup(sc_strm_task(sc), TASK_WOKEN_IO);
+}
+
+/*
+ * This function performs a shutdown-write on a detached stream connector in a
+ * connected or init state (it does nothing for other states). It either shuts
+ * the write side or marks itself as closed. The buffer flags are updated to
+ * reflect the new state. It does also close everything if the SC was marked as
+ * being in error state. The owner task is woken up if it exists.
+ */
+static void sc_app_shutw(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+ struct channel *oc = sc_oc(sc);
+
+ oc->flags &= ~CF_SHUTW_NOW;
+ if (oc->flags & CF_SHUTW)
+ return;
+ oc->flags |= CF_SHUTW;
+ oc->wex = TICK_ETERNITY;
+
+ if (tick_isset(sc->hcto)) {
+ ic->rto = sc->hcto;
+ ic->rex = tick_add(now_ms, ic->rto);
+ }
+
+ switch (sc->state) {
+ case SC_ST_RDY:
+ case SC_ST_EST:
+ /* we have to shut before closing, otherwise some short messages
+ * may never leave the system, especially when there are remaining
+ * unread data in the socket input buffer, or when nolinger is set.
+ * However, if SC_FL_NOLINGER is explicitly set, we know there is
+ * no risk so we close both sides immediately.
+ */
+ if (!sc_ep_test(sc, SE_FL_ERROR) && !(sc->flags & SC_FL_NOLINGER) &&
+ !(ic->flags & (CF_SHUTR|CF_DONT_READ)))
+ return;
+
+ /* fall through */
+ case SC_ST_CON:
+ case SC_ST_CER:
+ case SC_ST_QUE:
+ case SC_ST_TAR:
+ /* Note that none of these states may happen with applets */
+ sc->state = SC_ST_DIS;
+ /* fall through */
+ default:
+ sc->flags &= ~SC_FL_NOLINGER;
+ ic->flags |= CF_SHUTR;
+ ic->rex = TICK_ETERNITY;
+ if (sc->flags & SC_FL_ISBACK)
+ __sc_strm(sc)->conn_exp = TICK_ETERNITY;
+ }
+
+ /* note that if the task exists, it must unregister itself once it runs */
+ if (!(sc->flags & SC_FL_DONT_WAKE))
+ task_wakeup(sc_strm_task(sc), TASK_WOKEN_IO);
+}
+
+/* default chk_rcv function for scheduled tasks */
+static void sc_app_chk_rcv(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+
+ DPRINTF(stderr, "%s: sc=%p, sc->state=%d ic->flags=%08x oc->flags=%08x\n",
+ __FUNCTION__,
+ sc, sc->state, ic->flags, sc_oc(sc)->flags);
+
+ if (ic->pipe) {
+ /* stop reading */
+ sc_need_room(sc);
+ }
+ else {
+ /* (re)start reading */
+ if (!(sc->flags & SC_FL_DONT_WAKE))
+ task_wakeup(sc_strm_task(sc), TASK_WOKEN_IO);
+ }
+}
+
+/* default chk_snd function for scheduled tasks */
+static void sc_app_chk_snd(struct stconn *sc)
+{
+ struct channel *oc = sc_oc(sc);
+
+ DPRINTF(stderr, "%s: sc=%p, sc->state=%d ic->flags=%08x oc->flags=%08x\n",
+ __FUNCTION__,
+ sc, sc->state, sc_ic(sc)->flags, oc->flags);
+
+ if (unlikely(sc->state != SC_ST_EST || (oc->flags & CF_SHUTW)))
+ return;
+
+ if (!sc_ep_test(sc, SE_FL_WAIT_DATA) || /* not waiting for data */
+ channel_is_empty(oc)) /* called with nothing to send ! */
+ return;
+
+ /* Otherwise there are remaining data to be sent in the buffer,
+ * so we tell the handler.
+ */
+ sc_ep_clr(sc, SE_FL_WAIT_DATA);
+ if (!tick_isset(oc->wex))
+ oc->wex = tick_add_ifset(now_ms, oc->wto);
+
+ if (!(sc->flags & SC_FL_DONT_WAKE))
+ task_wakeup(sc_strm_task(sc), TASK_WOKEN_IO);
+}
+
+/*
+ * This function performs a shutdown-read on a stream connector attached to
+ * a connection in a connected or init state (it does nothing for other
+ * states). It either shuts the read side or marks itself as closed. The buffer
+ * flags are updated to reflect the new state. If the stream connector has
+ * SC_FL_NOHALF, we also forward the close to the write side. If a control
+ * layer is defined, then it is supposed to be a socket layer and file
+ * descriptors are then shutdown or closed accordingly. The function
+ * automatically disables polling if needed.
+ */
+static void sc_app_shutr_conn(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+
+ BUG_ON(!sc_conn(sc));
+
+ if (ic->flags & CF_SHUTR)
+ return;
+ ic->flags |= CF_SHUTR;
+ ic->rex = TICK_ETERNITY;
+
+ if (!sc_state_in(sc->state, SC_SB_CON|SC_SB_RDY|SC_SB_EST))
+ return;
+
+ if (sc_oc(sc)->flags & CF_SHUTW) {
+ sc_conn_shut(sc);
+ sc->state = SC_ST_DIS;
+ if (sc->flags & SC_FL_ISBACK)
+ __sc_strm(sc)->conn_exp = TICK_ETERNITY;
+ }
+ else if (sc_cond_forward_shutw(sc))
+ return sc_app_shutw_conn(sc);
+}
+
+/*
+ * This function performs a shutdown-write on a stream connector attached to
+ * a connection in a connected or init state (it does nothing for other
+ * states). It either shuts the write side or marks itself as closed. The
+ * buffer flags are updated to reflect the new state. It does also close
+ * everything if the SC was marked as being in error state. If there is a
+ * data-layer shutdown, it is called.
+ */
+static void sc_app_shutw_conn(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+ struct channel *oc = sc_oc(sc);
+
+ BUG_ON(!sc_conn(sc));
+
+ oc->flags &= ~CF_SHUTW_NOW;
+ if (oc->flags & CF_SHUTW)
+ return;
+ oc->flags |= CF_SHUTW;
+ oc->wex = TICK_ETERNITY;
+
+ if (tick_isset(sc->hcto)) {
+ ic->rto = sc->hcto;
+ ic->rex = tick_add(now_ms, ic->rto);
+ }
+
+ switch (sc->state) {
+ case SC_ST_RDY:
+ case SC_ST_EST:
+ /* we have to shut before closing, otherwise some short messages
+ * may never leave the system, especially when there are remaining
+ * unread data in the socket input buffer, or when nolinger is set.
+ * However, if SC_FL_NOLINGER is explicitly set, we know there is
+ * no risk so we close both sides immediately.
+ */
+
+ if (sc_ep_test(sc, SE_FL_ERROR)) {
+ /* quick close, the socket is already shut anyway */
+ }
+ else if (sc->flags & SC_FL_NOLINGER) {
+ /* unclean data-layer shutdown, typically an aborted request
+ * or a forwarded shutdown from a client to a server due to
+ * option abortonclose. No need for the TLS layer to try to
+ * emit a shutdown message.
+ */
+ sc_conn_shutw(sc, CO_SHW_SILENT);
+ }
+ else {
+ /* clean data-layer shutdown. This only happens on the
+ * frontend side, or on the backend side when forwarding
+ * a client close in TCP mode or in HTTP TUNNEL mode
+ * while option abortonclose is set. We want the TLS
+ * layer to try to signal it to the peer before we close.
+ */
+ sc_conn_shutw(sc, CO_SHW_NORMAL);
+
+ if (!(ic->flags & (CF_SHUTR|CF_DONT_READ)))
+ return;
+ }
+
+ /* fall through */
+ case SC_ST_CON:
+ /* we may have to close a pending connection, and mark the
+ * response buffer as shutr
+ */
+ sc_conn_shut(sc);
+ /* fall through */
+ case SC_ST_CER:
+ case SC_ST_QUE:
+ case SC_ST_TAR:
+ sc->state = SC_ST_DIS;
+ /* fall through */
+ default:
+ sc->flags &= ~SC_FL_NOLINGER;
+ ic->flags |= CF_SHUTR;
+ ic->rex = TICK_ETERNITY;
+ if (sc->flags & SC_FL_ISBACK)
+ __sc_strm(sc)->conn_exp = TICK_ETERNITY;
+ }
+}
+
+/* This function is used for inter-stream connector calls. It is called by the
+ * consumer to inform the producer side that it may be interested in checking
+ * for free space in the buffer. Note that it intentionally does not update
+ * timeouts, so that we can still check them later at wake-up. This function is
+ * dedicated to connection-based stream connectors.
+ */
+static void sc_app_chk_rcv_conn(struct stconn *sc)
+{
+ BUG_ON(!sc_conn(sc));
+
+ /* (re)start reading */
+ if (sc_state_in(sc->state, SC_SB_CON|SC_SB_RDY|SC_SB_EST))
+ tasklet_wakeup(sc->wait_event.tasklet);
+}
+
+
+/* This function is used for inter-stream connector calls. It is called by the
+ * producer to inform the consumer side that it may be interested in checking
+ * for data in the buffer. Note that it intentionally does not update timeouts,
+ * so that we can still check them later at wake-up.
+ */
+static void sc_app_chk_snd_conn(struct stconn *sc)
+{
+ struct channel *oc = sc_oc(sc);
+
+ BUG_ON(!sc_conn(sc));
+
+ if (unlikely(!sc_state_in(sc->state, SC_SB_RDY|SC_SB_EST) ||
+ (oc->flags & CF_SHUTW)))
+ return;
+
+ if (unlikely(channel_is_empty(oc))) /* called with nothing to send ! */
+ return;
+
+ if (!oc->pipe && /* spliced data wants to be forwarded ASAP */
+ !sc_ep_test(sc, SE_FL_WAIT_DATA)) /* not waiting for data */
+ return;
+
+ if (!(sc->wait_event.events & SUB_RETRY_SEND) && !channel_is_empty(sc_oc(sc)))
+ sc_conn_send(sc);
+
+ if (sc_ep_test(sc, SE_FL_ERROR | SE_FL_ERR_PENDING) || sc_is_conn_error(sc)) {
+ /* Write error on the file descriptor */
+ if (sc->state >= SC_ST_CON)
+ sc_ep_set(sc, SE_FL_ERROR);
+ goto out_wakeup;
+ }
+
+ /* OK, so now we know that some data might have been sent, and that we may
+ * have to poll first. We have to do that too if the buffer is not empty.
+ */
+ if (channel_is_empty(oc)) {
+ /* the connection is established but we can't write. Either the
+ * buffer is empty, or we just refrain from sending because the
+ * ->o limit was reached. Maybe we just wrote the last
+ * chunk and need to close.
+ */
+ if (((oc->flags & (CF_SHUTW|CF_AUTO_CLOSE|CF_SHUTW_NOW)) ==
+ (CF_AUTO_CLOSE|CF_SHUTW_NOW)) &&
+ sc_state_in(sc->state, SC_SB_RDY|SC_SB_EST)) {
+ sc_shutw(sc);
+ goto out_wakeup;
+ }
+
+ if ((oc->flags & (CF_SHUTW|CF_SHUTW_NOW)) == 0)
+ sc_ep_set(sc, SE_FL_WAIT_DATA);
+ oc->wex = TICK_ETERNITY;
+ }
+ else {
+ /* Otherwise there are remaining data to be sent in the buffer,
+ * which means we have to poll before doing so.
+ */
+ sc_ep_clr(sc, SE_FL_WAIT_DATA);
+ if (!tick_isset(oc->wex))
+ oc->wex = tick_add_ifset(now_ms, oc->wto);
+ }
+
+ if (likely(oc->flags & CF_WRITE_ACTIVITY)) {
+ struct channel *ic = sc_ic(sc);
+
+ /* update timeout if we have written something */
+ if ((oc->flags & (CF_SHUTW|CF_WRITE_PARTIAL)) == CF_WRITE_PARTIAL &&
+ !channel_is_empty(oc))
+ oc->wex = tick_add_ifset(now_ms, oc->wto);
+
+ if (tick_isset(ic->rex) && !(sc->flags & SC_FL_INDEP_STR)) {
+ /* Note: to prevent the client from expiring read timeouts
+ * during writes, we refresh it. We only do this if the
+ * interface is not configured for "independent streams",
+ * because for some applications it's better not to do this,
+ * for instance when continuously exchanging small amounts
+ * of data which can full the socket buffers long before a
+ * write timeout is detected.
+ */
+ ic->rex = tick_add_ifset(now_ms, ic->rto);
+ }
+ }
+
+ /* in case of special condition (error, shutdown, end of write...), we
+ * have to notify the task.
+ */
+ if (likely((oc->flags & (CF_WRITE_NULL|CF_WRITE_ERROR|CF_SHUTW)) ||
+ ((oc->flags & CF_WAKE_WRITE) &&
+ ((channel_is_empty(oc) && !oc->to_forward) ||
+ !sc_state_in(sc->state, SC_SB_EST))))) {
+ out_wakeup:
+ if (!(sc->flags & SC_FL_DONT_WAKE))
+ task_wakeup(sc_strm_task(sc), TASK_WOKEN_IO);
+ }
+}
+
+/*
+ * This function performs a shutdown-read on a stream connector attached to an
+ * applet in a connected or init state (it does nothing for other states). It
+ * either shuts the read side or marks itself as closed. The buffer flags are
+ * updated to reflect the new state. If the stream connector has SC_FL_NOHALF,
+ * we also forward the close to the write side. The owner task is woken up if
+ * it exists.
+ */
+static void sc_app_shutr_applet(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+
+ BUG_ON(!sc_appctx(sc));
+
+ if (ic->flags & CF_SHUTR)
+ return;
+ ic->flags |= CF_SHUTR;
+ ic->rex = TICK_ETERNITY;
+
+ /* Note: on shutr, we don't call the applet */
+
+ if (!sc_state_in(sc->state, SC_SB_CON|SC_SB_RDY|SC_SB_EST))
+ return;
+
+ if (sc_oc(sc)->flags & CF_SHUTW) {
+ appctx_shut(__sc_appctx(sc));
+ sc->state = SC_ST_DIS;
+ if (sc->flags & SC_FL_ISBACK)
+ __sc_strm(sc)->conn_exp = TICK_ETERNITY;
+ }
+ else if (sc_cond_forward_shutw(sc))
+ return sc_app_shutw_applet(sc);
+}
+
+/*
+ * This function performs a shutdown-write on a stream connector attached to an
+ * applet in a connected or init state (it does nothing for other states). It
+ * either shuts the write side or marks itself as closed. The buffer flags are
+ * updated to reflect the new state. It does also close everything if the SI
+ * was marked as being in error state. The owner task is woken up if it exists.
+ */
+static void sc_app_shutw_applet(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+ struct channel *oc = sc_oc(sc);
+
+ BUG_ON(!sc_appctx(sc));
+
+ oc->flags &= ~CF_SHUTW_NOW;
+ if (oc->flags & CF_SHUTW)
+ return;
+ oc->flags |= CF_SHUTW;
+ oc->wex = TICK_ETERNITY;
+
+ if (tick_isset(sc->hcto)) {
+ ic->rto = sc->hcto;
+ ic->rex = tick_add(now_ms, ic->rto);
+ }
+
+ /* on shutw we always wake the applet up */
+ appctx_wakeup(__sc_appctx(sc));
+
+ switch (sc->state) {
+ case SC_ST_RDY:
+ case SC_ST_EST:
+ /* we have to shut before closing, otherwise some short messages
+ * may never leave the system, especially when there are remaining
+ * unread data in the socket input buffer, or when nolinger is set.
+ * However, if SC_FL_NOLINGER is explicitly set, we know there is
+ * no risk so we close both sides immediately.
+ */
+ if (!sc_ep_test(sc, SE_FL_ERROR) && !(sc->flags & SC_FL_NOLINGER) &&
+ !(ic->flags & (CF_SHUTR|CF_DONT_READ)))
+ return;
+
+ /* fall through */
+ case SC_ST_CON:
+ case SC_ST_CER:
+ case SC_ST_QUE:
+ case SC_ST_TAR:
+ /* Note that none of these states may happen with applets */
+ appctx_shut(__sc_appctx(sc));
+ sc->state = SC_ST_DIS;
+ /* fall through */
+ default:
+ sc->flags &= ~SC_FL_NOLINGER;
+ ic->flags |= CF_SHUTR;
+ ic->rex = TICK_ETERNITY;
+ if (sc->flags & SC_FL_ISBACK)
+ __sc_strm(sc)->conn_exp = TICK_ETERNITY;
+ }
+}
+
+/* chk_rcv function for applets */
+static void sc_app_chk_rcv_applet(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+
+ BUG_ON(!sc_appctx(sc));
+
+ DPRINTF(stderr, "%s: sc=%p, sc->state=%d ic->flags=%08x oc->flags=%08x\n",
+ __FUNCTION__,
+ sc, sc->state, ic->flags, sc_oc(sc)->flags);
+
+ if (!ic->pipe) {
+ /* (re)start reading */
+ appctx_wakeup(__sc_appctx(sc));
+ }
+}
+
+/* chk_snd function for applets */
+static void sc_app_chk_snd_applet(struct stconn *sc)
+{
+ struct channel *oc = sc_oc(sc);
+
+ BUG_ON(!sc_appctx(sc));
+
+ DPRINTF(stderr, "%s: sc=%p, sc->state=%d ic->flags=%08x oc->flags=%08x\n",
+ __FUNCTION__,
+ sc, sc->state, sc_ic(sc)->flags, oc->flags);
+
+ if (unlikely(sc->state != SC_ST_EST || (oc->flags & CF_SHUTW)))
+ return;
+
+ /* we only wake the applet up if it was waiting for some data and is ready to consume it */
+ if (!sc_ep_test(sc, SE_FL_WAIT_DATA) || sc_ep_test(sc, SE_FL_WONT_CONSUME))
+ return;
+
+ if (!tick_isset(oc->wex))
+ oc->wex = tick_add_ifset(now_ms, oc->wto);
+
+ if (!channel_is_empty(oc)) {
+ /* (re)start sending */
+ appctx_wakeup(__sc_appctx(sc));
+ }
+}
+
+
+/* This function is designed to be called from within the stream handler to
+ * update the input channel's expiration timer and the stream connector's
+ * Rx flags based on the channel's flags. It needs to be called only once
+ * after the channel's flags have settled down, and before they are cleared,
+ * though it doesn't harm to call it as often as desired (it just slightly
+ * hurts performance). It must not be called from outside of the stream
+ * handler, as what it does will be used to compute the stream task's
+ * expiration.
+ */
+void sc_update_rx(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+
+ if (ic->flags & CF_SHUTR)
+ return;
+
+ /* Read not closed, update FD status and timeout for reads */
+ if (ic->flags & CF_DONT_READ)
+ sc_wont_read(sc);
+ else
+ sc_will_read(sc);
+
+ if (!channel_is_empty(ic) || !channel_may_recv(ic)) {
+ /* stop reading, imposed by channel's policy or contents */
+ sc_need_room(sc);
+ }
+ else {
+ /* (re)start reading and update timeout. Note: we don't recompute the timeout
+ * every time we get here, otherwise it would risk never to expire. We only
+ * update it if is was not yet set. The stream socket handler will already
+ * have updated it if there has been a completed I/O.
+ */
+ sc_have_room(sc);
+ }
+ if ((ic->flags & CF_EOI) || sc->flags & (SC_FL_WONT_READ|SC_FL_NEED_BUFF|SC_FL_NEED_ROOM))
+ ic->rex = TICK_ETERNITY;
+ else if (!(ic->flags & CF_READ_NOEXP) && !tick_isset(ic->rex))
+ ic->rex = tick_add_ifset(now_ms, ic->rto);
+
+ sc_chk_rcv(sc);
+}
+
+/* This function is designed to be called from within the stream handler to
+ * update the output channel's expiration timer and the stream connector's
+ * Tx flags based on the channel's flags. It needs to be called only once
+ * after the channel's flags have settled down, and before they are cleared,
+ * though it doesn't harm to call it as often as desired (it just slightly
+ * hurts performance). It must not be called from outside of the stream
+ * handler, as what it does will be used to compute the stream task's
+ * expiration.
+ */
+void sc_update_tx(struct stconn *sc)
+{
+ struct channel *oc = sc_oc(sc);
+ struct channel *ic = sc_ic(sc);
+
+ if (oc->flags & CF_SHUTW)
+ return;
+
+ /* Write not closed, update FD status and timeout for writes */
+ if (channel_is_empty(oc)) {
+ /* stop writing */
+ if (!sc_ep_test(sc, SE_FL_WAIT_DATA)) {
+ if ((oc->flags & CF_SHUTW_NOW) == 0)
+ sc_ep_set(sc, SE_FL_WAIT_DATA);
+ oc->wex = TICK_ETERNITY;
+ }
+ return;
+ }
+
+ /* (re)start writing and update timeout. Note: we don't recompute the timeout
+ * every time we get here, otherwise it would risk never to expire. We only
+ * update it if is was not yet set. The stream socket handler will already
+ * have updated it if there has been a completed I/O.
+ */
+ sc_ep_clr(sc, SE_FL_WAIT_DATA);
+ if (!tick_isset(oc->wex)) {
+ oc->wex = tick_add_ifset(now_ms, oc->wto);
+ if (tick_isset(ic->rex) && !(sc->flags & SC_FL_INDEP_STR)) {
+ /* Note: depending on the protocol, we don't know if we're waiting
+ * for incoming data or not. So in order to prevent the socket from
+ * expiring read timeouts during writes, we refresh the read timeout,
+ * except if it was already infinite or if we have explicitly setup
+ * independent streams.
+ */
+ ic->rex = tick_add_ifset(now_ms, ic->rto);
+ }
+ }
+}
+
+/* This function is the equivalent to sc_update() except that it's
+ * designed to be called from outside the stream handlers, typically the lower
+ * layers (applets, connections) after I/O completion. After updating the stream
+ * interface and timeouts, it will try to forward what can be forwarded, then to
+ * wake the associated task up if an important event requires special handling.
+ * It may update SE_FL_WAIT_DATA and/or SC_FL_NEED_ROOM, that the callers are
+ * encouraged to watch to take appropriate action.
+ * It should not be called from within the stream itself, sc_update()
+ * is designed for this.
+ */
+static void sc_notify(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+ struct channel *oc = sc_oc(sc);
+ struct stconn *sco = sc_opposite(sc);
+ struct task *task = sc_strm_task(sc);
+
+ /* process consumer side */
+ if (channel_is_empty(oc)) {
+ struct connection *conn = sc_conn(sc);
+
+ if (((oc->flags & (CF_SHUTW|CF_SHUTW_NOW)) == CF_SHUTW_NOW) &&
+ (sc->state == SC_ST_EST) && (!conn || !(conn->flags & (CO_FL_WAIT_XPRT | CO_FL_EARLY_SSL_HS))))
+ sc_shutw(sc);
+ oc->wex = TICK_ETERNITY;
+ }
+
+ /* indicate that we may be waiting for data from the output channel or
+ * we're about to close and can't expect more data if SHUTW_NOW is there.
+ */
+ if (!(oc->flags & (CF_SHUTW|CF_SHUTW_NOW)))
+ sc_ep_set(sc, SE_FL_WAIT_DATA);
+ else if ((oc->flags & (CF_SHUTW|CF_SHUTW_NOW)) == CF_SHUTW_NOW)
+ sc_ep_clr(sc, SE_FL_WAIT_DATA);
+
+ /* update OC timeouts and wake the other side up if it's waiting for room */
+ if (oc->flags & CF_WRITE_ACTIVITY) {
+ if ((oc->flags & (CF_SHUTW|CF_WRITE_PARTIAL)) == CF_WRITE_PARTIAL &&
+ !channel_is_empty(oc))
+ if (tick_isset(oc->wex))
+ oc->wex = tick_add_ifset(now_ms, oc->wto);
+
+ if (!(sc->flags & SC_FL_INDEP_STR))
+ if (tick_isset(ic->rex))
+ ic->rex = tick_add_ifset(now_ms, ic->rto);
+ }
+
+ if (oc->flags & CF_DONT_READ)
+ sc_wont_read(sco);
+ else
+ sc_will_read(sco);
+
+ /* Notify the other side when we've injected data into the IC that
+ * needs to be forwarded. We can do fast-forwarding as soon as there
+ * are output data, but we avoid doing this if some of the data are
+ * not yet scheduled for being forwarded, because it is very likely
+ * that it will be done again immediately afterwards once the following
+ * data are parsed (eg: HTTP chunking). We only clear SC_FL_NEED_ROOM
+ * once we've emptied *some* of the output buffer, and not just when
+ * there is available room, because applets are often forced to stop
+ * before the buffer is full. We must not stop based on input data
+ * alone because an HTTP parser might need more data to complete the
+ * parsing.
+ */
+ if (!channel_is_empty(ic) &&
+ sc_ep_test(sco, SE_FL_WAIT_DATA) &&
+ (!(ic->flags & CF_EXPECT_MORE) || c_full(ic) || ci_data(ic) == 0 || ic->pipe)) {
+ int new_len, last_len;
+
+ last_len = co_data(ic);
+ if (ic->pipe)
+ last_len += ic->pipe->data;
+
+ sc_chk_snd(sco);
+
+ new_len = co_data(ic);
+ if (ic->pipe)
+ new_len += ic->pipe->data;
+
+ /* check if the consumer has freed some space either in the
+ * buffer or in the pipe.
+ */
+ if (new_len < last_len)
+ sc_have_room(sc);
+ }
+
+ if (!(ic->flags & CF_DONT_READ))
+ sc_will_read(sc);
+
+ sc_chk_rcv(sc);
+ sc_chk_rcv(sco);
+
+ if (ic->flags & (CF_EOI|CF_SHUTR) || sc_ep_test(sc, SE_FL_APPLET_NEED_CONN) ||
+ (sc->flags & (SC_FL_WONT_READ|SC_FL_NEED_BUFF|SC_FL_NEED_ROOM))) {
+ ic->rex = TICK_ETERNITY;
+ }
+ else if ((ic->flags & (CF_SHUTR|CF_READ_PARTIAL)) == CF_READ_PARTIAL) {
+ /* we must re-enable reading if sc_chk_snd() has freed some space */
+ if (!(ic->flags & CF_READ_NOEXP) && tick_isset(ic->rex))
+ ic->rex = tick_add_ifset(now_ms, ic->rto);
+ }
+
+ /* wake the task up only when needed */
+ if (/* changes on the production side */
+ (ic->flags & (CF_READ_NULL|CF_READ_ERROR)) ||
+ !sc_state_in(sc->state, SC_SB_CON|SC_SB_RDY|SC_SB_EST) ||
+ sc_ep_test(sc, SE_FL_ERROR) ||
+ ((ic->flags & CF_READ_PARTIAL) &&
+ ((ic->flags & CF_EOI) || !ic->to_forward || sco->state != SC_ST_EST)) ||
+
+ /* changes on the consumption side */
+ (oc->flags & (CF_WRITE_NULL|CF_WRITE_ERROR)) ||
+ ((oc->flags & CF_WRITE_ACTIVITY) &&
+ ((oc->flags & CF_SHUTW) ||
+ (((oc->flags & CF_WAKE_WRITE) ||
+ !(oc->flags & (CF_AUTO_CLOSE|CF_SHUTW_NOW|CF_SHUTW))) &&
+ (sco->state != SC_ST_EST ||
+ (channel_is_empty(oc) && !oc->to_forward)))))) {
+ task_wakeup(task, TASK_WOKEN_IO);
+ }
+ else {
+ /* Update expiration date for the task and requeue it */
+ task->expire = tick_first((tick_is_expired(task->expire, now_ms) ? 0 : task->expire),
+ tick_first(tick_first(ic->rex, ic->wex),
+ tick_first(oc->rex, oc->wex)));
+
+ task->expire = tick_first(task->expire, ic->analyse_exp);
+ task->expire = tick_first(task->expire, oc->analyse_exp);
+ task->expire = tick_first(task->expire, __sc_strm(sc)->conn_exp);
+
+ task_queue(task);
+ }
+ if (ic->flags & CF_READ_ACTIVITY)
+ ic->flags &= ~CF_READ_DONTWAIT;
+}
+
+/*
+ * This function propagates a null read received on a socket-based connection.
+ * It updates the stream connector. If the stream connector has SC_FL_NOHALF,
+ * the close is also forwarded to the write side as an abort.
+ */
+static void sc_conn_read0(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+ struct channel *oc = sc_oc(sc);
+
+ BUG_ON(!sc_conn(sc));
+
+ if (ic->flags & CF_SHUTR)
+ return;
+ ic->flags |= CF_SHUTR;
+ ic->rex = TICK_ETERNITY;
+
+ if (!sc_state_in(sc->state, SC_SB_CON|SC_SB_RDY|SC_SB_EST))
+ return;
+
+ if (oc->flags & CF_SHUTW)
+ goto do_close;
+
+ if (sc_cond_forward_shutw(sc)) {
+ /* we want to immediately forward this close to the write side */
+ /* force flag on ssl to keep stream in cache */
+ sc_conn_shutw(sc, CO_SHW_SILENT);
+ goto do_close;
+ }
+
+ /* otherwise that's just a normal read shutdown */
+ return;
+
+ do_close:
+ /* OK we completely close the socket here just as if we went through sc_shut[rw]() */
+ sc_conn_shut(sc);
+
+ oc->flags &= ~CF_SHUTW_NOW;
+ oc->flags |= CF_SHUTW;
+ oc->wex = TICK_ETERNITY;
+
+ sc->state = SC_ST_DIS;
+ if (sc->flags & SC_FL_ISBACK)
+ __sc_strm(sc)->conn_exp = TICK_ETERNITY;
+ return;
+}
+
+/*
+ * This is the callback which is called by the connection layer to receive data
+ * into the buffer from the connection. It iterates over the mux layer's
+ * rcv_buf function.
+ */
+static int sc_conn_recv(struct stconn *sc)
+{
+ struct connection *conn = __sc_conn(sc);
+ struct channel *ic = sc_ic(sc);
+ int ret, max, cur_read = 0;
+ int read_poll = MAX_READ_POLL_LOOPS;
+ int flags = 0;
+
+ /* If not established yet, do nothing. */
+ if (sc->state != SC_ST_EST)
+ return 0;
+
+ /* If another call to sc_conn_recv() failed, and we subscribed to
+ * recv events already, give up now.
+ */
+ if (sc->wait_event.events & SUB_RETRY_RECV)
+ return 0;
+
+ /* maybe we were called immediately after an asynchronous shutr */
+ if (ic->flags & CF_SHUTR)
+ return 1;
+
+ /* we must wait because the mux is not installed yet */
+ if (!conn->mux)
+ return 0;
+
+ /* stop here if we reached the end of data */
+ if (sc_ep_test(sc, SE_FL_EOS))
+ goto end_recv;
+
+ /* stop immediately on errors. Note that we DON'T want to stop on
+ * POLL_ERR, as the poller might report a write error while there
+ * are still data available in the recv buffer. This typically
+ * happens when we send too large a request to a backend server
+ * which rejects it before reading it all.
+ */
+ if (!sc_ep_test(sc, SE_FL_RCV_MORE)) {
+ if (!conn_xprt_ready(conn))
+ return 0;
+ if (sc_ep_test(sc, SE_FL_ERROR))
+ goto end_recv;
+ }
+
+ /* prepare to detect if the mux needs more room */
+ sc_ep_clr(sc, SE_FL_WANT_ROOM);
+
+ if ((ic->flags & (CF_STREAMER | CF_STREAMER_FAST)) && !co_data(ic) &&
+ global.tune.idle_timer &&
+ (unsigned short)(now_ms - ic->last_read) >= global.tune.idle_timer) {
+ /* The buffer was empty and nothing was transferred for more
+ * than one second. This was caused by a pause and not by
+ * congestion. Reset any streaming mode to reduce latency.
+ */
+ ic->xfer_small = 0;
+ ic->xfer_large = 0;
+ ic->flags &= ~(CF_STREAMER | CF_STREAMER_FAST);
+ }
+
+ /* First, let's see if we may splice data across the channel without
+ * using a buffer.
+ */
+ if (sc_ep_test(sc, SE_FL_MAY_SPLICE) &&
+ (ic->pipe || ic->to_forward >= MIN_SPLICE_FORWARD) &&
+ ic->flags & CF_KERN_SPLICING) {
+ if (c_data(ic)) {
+ /* We're embarrassed, there are already data pending in
+ * the buffer and we don't want to have them at two
+ * locations at a time. Let's indicate we need some
+ * place and ask the consumer to hurry.
+ */
+ flags |= CO_RFL_BUF_FLUSH;
+ goto abort_splice;
+ }
+
+ if (unlikely(ic->pipe == NULL)) {
+ if (pipes_used >= global.maxpipes || !(ic->pipe = get_pipe())) {
+ ic->flags &= ~CF_KERN_SPLICING;
+ goto abort_splice;
+ }
+ }
+
+ ret = conn->mux->rcv_pipe(sc, ic->pipe, ic->to_forward);
+ if (ret < 0) {
+ /* splice not supported on this end, let's disable it */
+ ic->flags &= ~CF_KERN_SPLICING;
+ goto abort_splice;
+ }
+
+ if (ret > 0) {
+ if (ic->to_forward != CHN_INFINITE_FORWARD)
+ ic->to_forward -= ret;
+ ic->total += ret;
+ cur_read += ret;
+ ic->flags |= CF_READ_PARTIAL;
+ }
+
+ if (sc_ep_test(sc, SE_FL_EOS | SE_FL_ERROR))
+ goto end_recv;
+
+ if (conn->flags & CO_FL_WAIT_ROOM) {
+ /* the pipe is full or we have read enough data that it
+ * could soon be full. Let's stop before needing to poll.
+ */
+ sc_need_room(sc);
+ goto done_recv;
+ }
+
+ /* splice not possible (anymore), let's go on on standard copy */
+ }
+
+ abort_splice:
+ if (ic->pipe && unlikely(!ic->pipe->data)) {
+ put_pipe(ic->pipe);
+ ic->pipe = NULL;
+ }
+
+ if (ic->pipe && ic->to_forward && !(flags & CO_RFL_BUF_FLUSH) && sc_ep_test(sc, SE_FL_MAY_SPLICE)) {
+ /* don't break splicing by reading, but still call rcv_buf()
+ * to pass the flag.
+ */
+ goto done_recv;
+ }
+
+ /* now we'll need a input buffer for the stream */
+ if (!sc_alloc_ibuf(sc, &(__sc_strm(sc)->buffer_wait)))
+ goto end_recv;
+
+ /* For an HTX stream, if the buffer is stuck (no output data with some
+ * input data) and if the HTX message is fragmented or if its free space
+ * wraps, we force an HTX deframentation. It is a way to have a
+ * contiguous free space nad to let the mux to copy as much data as
+ * possible.
+ *
+ * NOTE: A possible optim may be to let the mux decides if defrag is
+ * required or not, depending on amount of data to be xferred.
+ */
+ if (IS_HTX_STRM(__sc_strm(sc)) && !co_data(ic)) {
+ struct htx *htx = htxbuf(&ic->buf);
+
+ if (htx_is_not_empty(htx) && ((htx->flags & HTX_FL_FRAGMENTED) || htx_space_wraps(htx)))
+ htx_defrag(htx, NULL, 0);
+ }
+
+ /* Instruct the mux it must subscribed for read events */
+ flags |= ((!conn_is_back(conn) && (__sc_strm(sc)->be->options & PR_O_ABRT_CLOSE)) ? CO_RFL_KEEP_RECV : 0);
+
+ /* Important note : if we're called with POLL_IN|POLL_HUP, it means the read polling
+ * was enabled, which implies that the recv buffer was not full. So we have a guarantee
+ * that if such an event is not handled above in splice, it will be handled here by
+ * recv().
+ */
+ while (sc_ep_test(sc, SE_FL_RCV_MORE) ||
+ (!(conn->flags & CO_FL_HANDSHAKE) &&
+ (!sc_ep_test(sc, SE_FL_ERROR | SE_FL_EOS)) && !(ic->flags & CF_SHUTR))) {
+ int cur_flags = flags;
+
+ /* Compute transient CO_RFL_* flags */
+ if (co_data(ic)) {
+ cur_flags |= (CO_RFL_BUF_WET | CO_RFL_BUF_NOT_STUCK);
+ }
+
+ /* <max> may be null. This is the mux responsibility to set
+ * SE_FL_RCV_MORE on the SC if more space is needed.
+ */
+ max = channel_recv_max(ic);
+ ret = conn->mux->rcv_buf(sc, &ic->buf, max, cur_flags);
+
+ if (sc_ep_test(sc, SE_FL_WANT_ROOM)) {
+ /* SE_FL_WANT_ROOM must not be reported if the channel's
+ * buffer is empty.
+ */
+ BUG_ON(c_empty(ic));
+
+ sc_need_room(sc);
+ /* Add READ_PARTIAL because some data are pending but
+ * cannot be xferred to the channel
+ */
+ ic->flags |= CF_READ_PARTIAL;
+ }
+
+ if (ret <= 0) {
+ /* if we refrained from reading because we asked for a
+ * flush to satisfy rcv_pipe(), we must not subscribe
+ * and instead report that there's not enough room
+ * here to proceed.
+ */
+ if (flags & CO_RFL_BUF_FLUSH)
+ sc_need_room(sc);
+ break;
+ }
+
+ cur_read += ret;
+
+ /* if we're allowed to directly forward data, we must update ->o */
+ if (ic->to_forward && !(ic->flags & (CF_SHUTW|CF_SHUTW_NOW))) {
+ unsigned long fwd = ret;
+ if (ic->to_forward != CHN_INFINITE_FORWARD) {
+ if (fwd > ic->to_forward)
+ fwd = ic->to_forward;
+ ic->to_forward -= fwd;
+ }
+ c_adv(ic, fwd);
+ }
+
+ ic->flags |= CF_READ_PARTIAL;
+ ic->total += ret;
+
+ /* End-of-input reached, we can leave. In this case, it is
+ * important to break the loop to not block the SC because of
+ * the channel's policies.This way, we are still able to receive
+ * shutdowns.
+ */
+ if (sc_ep_test(sc, SE_FL_EOI))
+ break;
+
+ if ((ic->flags & CF_READ_DONTWAIT) || --read_poll <= 0) {
+ /* we're stopped by the channel's policy */
+ sc_wont_read(sc);
+ break;
+ }
+
+ /* if too many bytes were missing from last read, it means that
+ * it's pointless trying to read again because the system does
+ * not have them in buffers.
+ */
+ if (ret < max) {
+ /* if a streamer has read few data, it may be because we
+ * have exhausted system buffers. It's not worth trying
+ * again.
+ */
+ if (ic->flags & CF_STREAMER) {
+ /* we're stopped by the channel's policy */
+ sc_wont_read(sc);
+ break;
+ }
+
+ /* if we read a large block smaller than what we requested,
+ * it's almost certain we'll never get anything more.
+ */
+ if (ret >= global.tune.recv_enough) {
+ /* we're stopped by the channel's policy */
+ sc_wont_read(sc);
+ break;
+ }
+ }
+
+ /* if we are waiting for more space, don't try to read more data
+ * right now.
+ */
+ if (sc->flags & (SC_FL_WONT_READ|SC_FL_NEED_BUFF|SC_FL_NEED_ROOM))
+ break;
+ } /* while !flags */
+
+ done_recv:
+ if (cur_read) {
+ if ((ic->flags & (CF_STREAMER | CF_STREAMER_FAST)) &&
+ (cur_read <= ic->buf.size / 2)) {
+ ic->xfer_large = 0;
+ ic->xfer_small++;
+ if (ic->xfer_small >= 3) {
+ /* we have read less than half of the buffer in
+ * one pass, and this happened at least 3 times.
+ * This is definitely not a streamer.
+ */
+ ic->flags &= ~(CF_STREAMER | CF_STREAMER_FAST);
+ }
+ else if (ic->xfer_small >= 2) {
+ /* if the buffer has been at least half full twice,
+ * we receive faster than we send, so at least it
+ * is not a "fast streamer".
+ */
+ ic->flags &= ~CF_STREAMER_FAST;
+ }
+ }
+ else if (!(ic->flags & CF_STREAMER_FAST) &&
+ (cur_read >= ic->buf.size - global.tune.maxrewrite)) {
+ /* we read a full buffer at once */
+ ic->xfer_small = 0;
+ ic->xfer_large++;
+ if (ic->xfer_large >= 3) {
+ /* we call this buffer a fast streamer if it manages
+ * to be filled in one call 3 consecutive times.
+ */
+ ic->flags |= (CF_STREAMER | CF_STREAMER_FAST);
+ }
+ }
+ else {
+ ic->xfer_small = 0;
+ ic->xfer_large = 0;
+ }
+ ic->last_read = now_ms;
+ }
+
+ end_recv:
+ ret = (cur_read != 0);
+
+ /* Report EOI on the channel if it was reached from the mux point of
+ * view. */
+ if (sc_ep_test(sc, SE_FL_EOI) && !(ic->flags & CF_EOI)) {
+ ic->flags |= (CF_EOI|CF_READ_PARTIAL);
+ ret = 1;
+ }
+
+ if (sc_ep_test(sc, SE_FL_ERROR))
+ ret = 1;
+ else if (sc_ep_test(sc, SE_FL_EOS)) {
+ /* we received a shutdown */
+ ic->flags |= CF_READ_NULL;
+ if (ic->flags & CF_AUTO_CLOSE)
+ channel_shutw_now(ic);
+ sc_conn_read0(sc);
+ ret = 1;
+ }
+ else if (!(sc->flags & (SC_FL_WONT_READ|SC_FL_NEED_BUFF|SC_FL_NEED_ROOM)) &&
+ !(ic->flags & CF_SHUTR)) {
+ /* Subscribe to receive events if we're blocking on I/O */
+ conn->mux->subscribe(sc, SUB_RETRY_RECV, &sc->wait_event);
+ se_have_no_more_data(sc->sedesc);
+ } else {
+ se_have_more_data(sc->sedesc);
+ ret = 1;
+ }
+ return ret;
+}
+
+/* This tries to perform a synchronous receive on the stream connector to
+ * try to collect last arrived data. In practice it's only implemented on
+ * stconns. Returns 0 if nothing was done, non-zero if new data or a
+ * shutdown were collected. This may result on some delayed receive calls
+ * to be programmed and performed later, though it doesn't provide any
+ * such guarantee.
+ */
+int sc_conn_sync_recv(struct stconn *sc)
+{
+ if (!sc_state_in(sc->state, SC_SB_RDY|SC_SB_EST))
+ return 0;
+
+ if (!sc_mux_ops(sc))
+ return 0; // only stconns are supported
+
+ if (sc->wait_event.events & SUB_RETRY_RECV)
+ return 0; // already subscribed
+
+ if (!sc_is_recv_allowed(sc))
+ return 0; // already failed
+
+ return sc_conn_recv(sc);
+}
+
+/*
+ * This function is called to send buffer data to a stream socket.
+ * It calls the mux layer's snd_buf function. It relies on the
+ * caller to commit polling changes. The caller should check conn->flags
+ * for errors.
+ */
+static int sc_conn_send(struct stconn *sc)
+{
+ struct connection *conn = __sc_conn(sc);
+ struct stream *s = __sc_strm(sc);
+ struct channel *oc = sc_oc(sc);
+ int ret;
+ int did_send = 0;
+
+ if (sc_ep_test(sc, SE_FL_ERROR | SE_FL_ERR_PENDING) || sc_is_conn_error(sc)) {
+ /* We're probably there because the tasklet was woken up,
+ * but process_stream() ran before, detected there were an
+ * error and put the SC back to SC_ST_TAR. There's still
+ * CO_FL_ERROR on the connection but we don't want to add
+ * SE_FL_ERROR back, so give up
+ */
+ if (sc->state < SC_ST_CON)
+ return 0;
+ sc_ep_set(sc, SE_FL_ERROR);
+ return 1;
+ }
+
+ /* We're already waiting to be able to send, give up */
+ if (sc->wait_event.events & SUB_RETRY_SEND)
+ return 0;
+
+ /* we might have been called just after an asynchronous shutw */
+ if (oc->flags & CF_SHUTW)
+ return 1;
+
+ /* we must wait because the mux is not installed yet */
+ if (!conn->mux)
+ return 0;
+
+ if (oc->pipe && conn->xprt->snd_pipe && conn->mux->snd_pipe) {
+ ret = conn->mux->snd_pipe(sc, oc->pipe);
+ if (ret > 0)
+ did_send = 1;
+
+ if (!oc->pipe->data) {
+ put_pipe(oc->pipe);
+ oc->pipe = NULL;
+ }
+
+ if (oc->pipe)
+ goto end;
+ }
+
+ /* At this point, the pipe is empty, but we may still have data pending
+ * in the normal buffer.
+ */
+ if (co_data(oc)) {
+ /* when we're here, we already know that there is no spliced
+ * data left, and that there are sendable buffered data.
+ */
+
+ /* check if we want to inform the kernel that we're interested in
+ * sending more data after this call. We want this if :
+ * - we're about to close after this last send and want to merge
+ * the ongoing FIN with the last segment.
+ * - we know we can't send everything at once and must get back
+ * here because of unaligned data
+ * - there is still a finite amount of data to forward
+ * The test is arranged so that the most common case does only 2
+ * tests.
+ */
+ unsigned int send_flag = 0;
+
+ if ((!(oc->flags & (CF_NEVER_WAIT|CF_SEND_DONTWAIT)) &&
+ ((oc->to_forward && oc->to_forward != CHN_INFINITE_FORWARD) ||
+ (oc->flags & CF_EXPECT_MORE) ||
+ (IS_HTX_STRM(s) &&
+ (!(oc->flags & (CF_EOI|CF_SHUTR)) && htx_expect_more(htxbuf(&oc->buf)))))) ||
+ ((oc->flags & CF_ISRESP) &&
+ ((oc->flags & (CF_AUTO_CLOSE|CF_SHUTW_NOW)) == (CF_AUTO_CLOSE|CF_SHUTW_NOW))))
+ send_flag |= CO_SFL_MSG_MORE;
+
+ if (oc->flags & CF_STREAMER)
+ send_flag |= CO_SFL_STREAMER;
+
+ if (s->txn && s->txn->flags & TX_L7_RETRY && !b_data(&s->txn->l7_buffer)) {
+ /* If we want to be able to do L7 retries, copy
+ * the data we're about to send, so that we are able
+ * to resend them if needed
+ */
+ /* Try to allocate a buffer if we had none.
+ * If it fails, the next test will just
+ * disable the l7 retries by setting
+ * l7_conn_retries to 0.
+ */
+ if (s->txn->req.msg_state != HTTP_MSG_DONE)
+ s->txn->flags &= ~TX_L7_RETRY;
+ else {
+ if (b_alloc(&s->txn->l7_buffer) == NULL)
+ s->txn->flags &= ~TX_L7_RETRY;
+ else {
+ memcpy(b_orig(&s->txn->l7_buffer),
+ b_orig(&oc->buf),
+ b_size(&oc->buf));
+ s->txn->l7_buffer.head = co_data(oc);
+ b_add(&s->txn->l7_buffer, co_data(oc));
+ }
+
+ }
+ }
+
+ ret = conn->mux->snd_buf(sc, &oc->buf, co_data(oc), send_flag);
+ if (ret > 0) {
+ did_send = 1;
+ c_rew(oc, ret);
+ c_realign_if_empty(oc);
+
+ if (!co_data(oc)) {
+ /* Always clear both flags once everything has been sent, they're one-shot */
+ oc->flags &= ~(CF_EXPECT_MORE | CF_SEND_DONTWAIT);
+ }
+ /* if some data remain in the buffer, it's only because the
+ * system buffers are full, we will try next time.
+ */
+ }
+ }
+
+ end:
+ if (did_send) {
+ oc->flags |= CF_WRITE_PARTIAL | CF_WROTE_DATA;
+ if (sc->state == SC_ST_CON)
+ sc->state = SC_ST_RDY;
+
+ sc_have_room(sc_opposite(sc));
+ }
+
+ if (sc_ep_test(sc, SE_FL_ERROR | SE_FL_ERR_PENDING)) {
+ sc_ep_set(sc, SE_FL_ERROR);
+ return 1;
+ }
+
+ /* We couldn't send all of our data, let the mux know we'd like to send more */
+ if (!channel_is_empty(oc))
+ conn->mux->subscribe(sc, SUB_RETRY_SEND, &sc->wait_event);
+ return did_send;
+}
+
+/* perform a synchronous send() for the stream connector. The CF_WRITE_NULL and
+ * CF_WRITE_PARTIAL flags are cleared prior to the attempt, and will possibly
+ * be updated in case of success.
+ */
+void sc_conn_sync_send(struct stconn *sc)
+{
+ struct channel *oc = sc_oc(sc);
+
+ oc->flags &= ~(CF_WRITE_NULL|CF_WRITE_PARTIAL);
+
+ if (oc->flags & CF_SHUTW)
+ return;
+
+ if (channel_is_empty(oc))
+ return;
+
+ if (!sc_state_in(sc->state, SC_SB_CON|SC_SB_RDY|SC_SB_EST))
+ return;
+
+ if (!sc_mux_ops(sc))
+ return;
+
+ sc_conn_send(sc);
+}
+
+/* Called by I/O handlers after completion.. It propagates
+ * connection flags to the stream connector, updates the stream (which may or
+ * may not take this opportunity to try to forward data), then update the
+ * connection's polling based on the channels and stream connector's final
+ * states. The function always returns 0.
+ */
+static int sc_conn_process(struct stconn *sc)
+{
+ struct connection *conn = __sc_conn(sc);
+ struct channel *ic = sc_ic(sc);
+ struct channel *oc = sc_oc(sc);
+
+ BUG_ON(!conn);
+
+ /* If we have data to send, try it now */
+ if (!channel_is_empty(oc) && !(sc->wait_event.events & SUB_RETRY_SEND))
+ sc_conn_send(sc);
+
+ /* First step, report to the stream connector what was detected at the
+ * connection layer : errors and connection establishment.
+ * Only add SE_FL_ERROR if we're connected, or we're attempting to
+ * connect, we may get there because we got woken up, but only run
+ * after process_stream() noticed there were an error, and decided
+ * to retry to connect, the connection may still have CO_FL_ERROR,
+ * and we don't want to add SE_FL_ERROR back
+ *
+ * Note: This test is only required because sc_conn_process is also the SI
+ * wake callback. Otherwise sc_conn_recv()/sc_conn_send() already take
+ * care of it.
+ */
+
+ if (sc->state >= SC_ST_CON) {
+ if (sc_is_conn_error(sc))
+ sc_ep_set(sc, SE_FL_ERROR);
+ }
+
+ /* If we had early data, and the handshake ended, then
+ * we can remove the flag, and attempt to wake the task up,
+ * in the event there's an analyser waiting for the end of
+ * the handshake.
+ */
+ if (!(conn->flags & (CO_FL_WAIT_XPRT | CO_FL_EARLY_SSL_HS)) &&
+ sc_ep_test(sc, SE_FL_WAIT_FOR_HS)) {
+ sc_ep_clr(sc, SE_FL_WAIT_FOR_HS);
+ task_wakeup(sc_strm_task(sc), TASK_WOKEN_MSG);
+ }
+
+ if (!sc_state_in(sc->state, SC_SB_EST|SC_SB_DIS|SC_SB_CLO) &&
+ (conn->flags & CO_FL_WAIT_XPRT) == 0) {
+ if (sc->flags & SC_FL_ISBACK)
+ __sc_strm(sc)->conn_exp = TICK_ETERNITY;
+ oc->flags |= CF_WRITE_NULL;
+ if (sc->state == SC_ST_CON)
+ sc->state = SC_ST_RDY;
+ }
+
+ /* Report EOS on the channel if it was reached from the mux point of
+ * view.
+ *
+ * Note: This test is only required because sc_conn_process is also the SI
+ * wake callback. Otherwise sc_conn_recv()/sc_conn_send() already take
+ * care of it.
+ */
+ if (sc_ep_test(sc, SE_FL_EOS) && !(ic->flags & CF_SHUTR)) {
+ /* we received a shutdown */
+ ic->flags |= CF_READ_NULL;
+ if (ic->flags & CF_AUTO_CLOSE)
+ channel_shutw_now(ic);
+ sc_conn_read0(sc);
+ }
+
+ /* Report EOI on the channel if it was reached from the mux point of
+ * view.
+ *
+ * Note: This test is only required because sc_conn_process is also the SI
+ * wake callback. Otherwise sc_conn_recv()/sc_conn_send() already take
+ * care of it.
+ */
+ if (sc_ep_test(sc, SE_FL_EOI) && !(ic->flags & CF_EOI))
+ ic->flags |= (CF_EOI|CF_READ_PARTIAL);
+
+ /* Second step : update the stream connector and channels, try to forward any
+ * pending data, then possibly wake the stream up based on the new
+ * stream connector status.
+ */
+ sc_notify(sc);
+ stream_release_buffers(__sc_strm(sc));
+ return 0;
+}
+
+/* This is the ->process() function for any stream connector's wait_event task.
+ * It's assigned during the stream connector's initialization, for any type of
+ * stream connector. Thus it is always safe to perform a tasklet_wakeup() on a
+ * stream connector, as the presence of the SC is checked there.
+ */
+struct task *sc_conn_io_cb(struct task *t, void *ctx, unsigned int state)
+{
+ struct stconn *sc = ctx;
+ int ret = 0;
+
+ if (!sc_conn(sc))
+ return t;
+
+ if (!(sc->wait_event.events & SUB_RETRY_SEND) && !channel_is_empty(sc_oc(sc)))
+ ret = sc_conn_send(sc);
+ if (!(sc->wait_event.events & SUB_RETRY_RECV))
+ ret |= sc_conn_recv(sc);
+ if (ret != 0)
+ sc_conn_process(sc);
+
+ stream_release_buffers(__sc_strm(sc));
+ return t;
+}
+
+/* Callback to be used by applet handlers upon completion. It updates the stream
+ * (which may or may not take this opportunity to try to forward data), then
+ * may re-enable the applet's based on the channels and stream connector's final
+ * states.
+ */
+static int sc_applet_process(struct stconn *sc)
+{
+ struct channel *ic = sc_ic(sc);
+
+ BUG_ON(!sc_appctx(sc));
+
+ /* If the applet wants to write and the channel is closed, it's a
+ * broken pipe and it must be reported.
+ */
+ if (!sc_ep_test(sc, SE_FL_HAVE_NO_DATA) && (ic->flags & CF_SHUTR))
+ sc_ep_set(sc, SE_FL_ERROR);
+
+ /* automatically mark the applet having data available if it reported
+ * begin blocked by the channel.
+ */
+ if ((sc->flags & (SC_FL_WONT_READ|SC_FL_NEED_BUFF|SC_FL_NEED_ROOM)) ||
+ sc_ep_test(sc, SE_FL_APPLET_NEED_CONN))
+ applet_have_more_data(__sc_appctx(sc));
+
+ /* update the stream connector, channels, and possibly wake the stream up */
+ sc_notify(sc);
+ stream_release_buffers(__sc_strm(sc));
+
+ /* sc_notify may have passed through chk_snd and released some blocking
+ * flags. Process_stream will consider those flags to wake up the
+ * appctx but in the case the task is not in runqueue we may have to
+ * wakeup the appctx immediately.
+ */
+ if (sc_is_recv_allowed(sc) || sc_is_send_allowed(sc))
+ appctx_wakeup(__sc_appctx(sc));
+ return 0;
+}
+
+
+/* Prepares an endpoint upgrade. We don't now at this stage if the upgrade will
+ * succeed or not and if the stconn will be reused by the new endpoint. Thus,
+ * for now, only pretend the stconn is detached.
+ */
+void sc_conn_prepare_endp_upgrade(struct stconn *sc)
+{
+ BUG_ON(!sc_conn(sc) || !sc->app);
+ sc_ep_clr(sc, SE_FL_T_MUX);
+ sc_ep_set(sc, SE_FL_DETACHED);
+}
+
+/* Endpoint upgrade failed. Restore the stconn state. */
+void sc_conn_abort_endp_upgrade(struct stconn *sc)
+{
+ sc_ep_set(sc, SE_FL_T_MUX);
+ sc_ep_clr(sc, SE_FL_DETACHED);
+}
+
+/* Commit the endpoint upgrade. If stconn is attached, it means the new endpoint
+ * use it. So we do nothing. Otherwise, the stconn will be destroy with the
+ * overlying stream. So, it means we must commit the detach.
+*/
+void sc_conn_commit_endp_upgrade(struct stconn *sc)
+{
+ if (!sc_ep_test(sc, SE_FL_DETACHED))
+ return;
+ sc_detach_endp(&sc);
+ /* Because it was already set as detached, the sedesc must be preserved */
+ BUG_ON(!sc);
+ BUG_ON(!sc->sedesc);
+}