flow: Record the pifs for each side of each flow

Currently we have no generic information flows apart from the type and
state, everything else is specific to the flow type.  Start introducing
generic flow information by recording the pifs which the flow connects.

To keep track of what information is valid, introduce new flow states:
INI for when the initiating side information is complete, and TGT for
when both sides information is complete, but we haven't chosen the
flow type yet.  For now, these states don't do an awful lot, but
they'll become more important as we add more generic information.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 52 insertions, 4 deletions

diff --git a/flow.c b/flow.c
index 91c0046..d05aa49 100644
--- a/flow.c
+++ b/flow.c
@@ -21,6 +21,8 @@
 const char *flow_state_str[] = {
 	[FLOW_STATE_FREE]	= "FREE",
 	[FLOW_STATE_NEW]	= "NEW",
+	[FLOW_STATE_INI]	= "INI",
+	[FLOW_STATE_TGT]	= "TGT",
 	[FLOW_STATE_TYPED]	= "TYPED",
 	[FLOW_STATE_ACTIVE]	= "ACTIVE",
 };
@@ -146,22 +148,63 @@ static void flow_set_state(struct flow_common *f, enum flow_state state)
 	f->state = state;
 	flow_log_(f, LOG_DEBUG, "%s -> %s", flow_state_str[oldstate],
 		  FLOW_STATE(f));
+
+	if (MAX(state, oldstate) >= FLOW_STATE_TGT)
+		flow_log_(f, LOG_DEBUG, "%s => %s", pif_name(f->pif[INISIDE]),
+			                            pif_name(f->pif[TGTSIDE]));
+	else if (MAX(state, oldstate) >= FLOW_STATE_INI)
+		flow_log_(f, LOG_DEBUG, "%s => ?", pif_name(f->pif[INISIDE]));
+}
+
+/**
+ * flow_initiate() - Move flow to INI, setting INISIDE details
+ * @flow:	Flow to change state
+ * @pif:	pif of the initiating side
+ */
+void flow_initiate(union flow *flow, uint8_t pif)
+{
+	struct flow_common *f = &flow->f;
+
+	ASSERT(pif != PIF_NONE);
+	ASSERT(flow_new_entry == flow && f->state == FLOW_STATE_NEW);
+	ASSERT(f->type == FLOW_TYPE_NONE);
+	ASSERT(f->pif[INISIDE] == PIF_NONE && f->pif[TGTSIDE] == PIF_NONE);
+
+	f->pif[INISIDE] = pif;
+	flow_set_state(f, FLOW_STATE_INI);
+}
+
+/**
+ * flow_target() - Move flow to TGT, setting TGTSIDE details
+ * @flow:	Flow to change state
+ * @pif:	pif of the target side
+ */
+void flow_target(union flow *flow, uint8_t pif)
+{
+	struct flow_common *f = &flow->f;
+
+	ASSERT(pif != PIF_NONE);
+	ASSERT(flow_new_entry == flow && f->state == FLOW_STATE_INI);
+	ASSERT(f->type == FLOW_TYPE_NONE);
+	ASSERT(f->pif[INISIDE] != PIF_NONE && f->pif[TGTSIDE] == PIF_NONE);
+
+	f->pif[TGTSIDE] = pif;
+	flow_set_state(f, FLOW_STATE_TGT);
 }
 
 /**
  * flow_set_type() - Set type and move to TYPED
  * @flow:	Flow to change state
- * @type:	Type for new flow
- *
- * Return: @flow
+ * @pif:	pif of the initiating side
  */
 union flow *flow_set_type(union flow *flow, enum flow_type type)
 {
 	struct flow_common *f = &flow->f;
 
 	ASSERT(type != FLOW_TYPE_NONE);
-	ASSERT(flow_new_entry == flow && f->state == FLOW_STATE_NEW);
+	ASSERT(flow_new_entry == flow && f->state == FLOW_STATE_TGT);
 	ASSERT(f->type == FLOW_TYPE_NONE);
+	ASSERT(f->pif[INISIDE] != PIF_NONE && f->pif[TGTSIDE] != PIF_NONE);
 
 	f->type = type;
 	flow_set_state(f, FLOW_STATE_TYPED);
@@ -175,6 +218,7 @@ union flow *flow_set_type(union flow *flow, enum flow_type type)
 void flow_activate(struct flow_common *f)
 {
 	ASSERT(&flow_new_entry->f == f && f->state == FLOW_STATE_TYPED);
+	ASSERT(f->pif[INISIDE] != PIF_NONE && f->pif[TGTSIDE] != PIF_NONE);
 
 	flow_set_state(f, FLOW_STATE_ACTIVE);
 	flow_new_entry = NULL;
@@ -234,6 +278,8 @@ void flow_alloc_cancel(union flow *flow)
 {
 	ASSERT(flow_new_entry == flow);
 	ASSERT(flow->f.state == FLOW_STATE_NEW ||
+	       flow->f.state == FLOW_STATE_INI ||
+	       flow->f.state == FLOW_STATE_TGT ||
 	       flow->f.state == FLOW_STATE_TYPED);
 	ASSERT(flow_first_free > FLOW_IDX(flow));
 
@@ -296,6 +342,8 @@ void flow_defer_handler(const struct ctx *c, const struct timespec *now)
 		}
 
 		case FLOW_STATE_NEW:
+		case FLOW_STATE_INI:
+		case FLOW_STATE_TGT:
 		case FLOW_STATE_TYPED:
 			/* Incomplete flow at end of cycle */
 			ASSERT(false);