From 88bfa3801e187ac33ca9de552612bc30a1708c72 Mon Sep 17 00:00:00 2001
From: David Gibson <david@gibson.dropbear.id.au>
Date: Fri, 6 Sep 2024 15:17:07 +1000
Subject: [PATCH] flow: Helpers to log details of a flow

The details of a flow - endpoints, interfaces etc. - can be pretty
important for debugging.  We log this on flow state transitions, but it can
also be useful to log this when we report specific conditions.  Add some
helper functions and macros to make it easy to do that.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 flow.c | 48 +++++++++++++++++++++++++++++++-----------------
 flow.h |  7 +++++++
 2 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/flow.c b/flow.c
index f2de041..1ea112b 100644
--- a/flow.c
+++ b/flow.c
@@ -283,28 +283,23 @@ void flow_log_(const struct flow_common *f, int pri, const char *fmt, ...)
 	       "Flow %u (%s): %s", flow_idx(f), type_or_state, msg);
 }
 
-/**
- * flow_set_state() - Change flow's state
- * @f:		Flow changing state
- * @state:	New state
+/** flow_log_details_() - Log the details of a flow
+ * @f:		flow to log
+ * @pri:	Log priority
+ * @state:	State to log details according to
+ *
+ * Logs the details of the flow: endpoints, interfaces, type etc.
  */
-static void flow_set_state(struct flow_common *f, enum flow_state state)
+void flow_log_details_(const struct flow_common *f, int pri,
+		       enum flow_state state)
 {
 	char estr0[INANY_ADDRSTRLEN], fstr0[INANY_ADDRSTRLEN];
 	char estr1[INANY_ADDRSTRLEN], fstr1[INANY_ADDRSTRLEN];
 	const struct flowside *ini = &f->side[INISIDE];
 	const struct flowside *tgt = &f->side[TGTSIDE];
-	uint8_t oldstate = f->state;
 
-	ASSERT(state < FLOW_NUM_STATES);
-	ASSERT(oldstate < FLOW_NUM_STATES);
-
-	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,
+	if (state >= FLOW_STATE_TGT)
+		flow_log_(f, pri,
 			  "%s [%s]:%hu -> [%s]:%hu => %s [%s]:%hu -> [%s]:%hu",
 			  pif_name(f->pif[INISIDE]),
 			  inany_ntop(&ini->eaddr, estr0, sizeof(estr0)),
@@ -316,8 +311,8 @@ static void flow_set_state(struct flow_common *f, enum flow_state state)
 			  tgt->oport,
 			  inany_ntop(&tgt->eaddr, estr1, sizeof(estr1)),
 			  tgt->eport);
-	else if (MAX(state, oldstate) >= FLOW_STATE_INI)
-		flow_log_(f, LOG_DEBUG, "%s [%s]:%hu -> [%s]:%hu => ?",
+	else if (state >= FLOW_STATE_INI)
+		flow_log_(f, pri, "%s [%s]:%hu -> [%s]:%hu => ?",
 			  pif_name(f->pif[INISIDE]),
 			  inany_ntop(&ini->eaddr, estr0, sizeof(estr0)),
 			  ini->eport,
@@ -325,6 +320,25 @@ static void flow_set_state(struct flow_common *f, enum flow_state state)
 			  ini->oport);
 }
 
+/**
+ * flow_set_state() - Change flow's state
+ * @f:		Flow changing state
+ * @state:	New state
+ */
+static void flow_set_state(struct flow_common *f, enum flow_state state)
+{
+	uint8_t oldstate = f->state;
+
+	ASSERT(state < FLOW_NUM_STATES);
+	ASSERT(oldstate < FLOW_NUM_STATES);
+
+	f->state = state;
+	flow_log_(f, LOG_DEBUG, "%s -> %s", flow_state_str[oldstate],
+		  FLOW_STATE(f));
+
+	flow_log_details_(f, LOG_DEBUG, MAX(state, oldstate));
+}
+
 /**
  * flow_initiate_() - Move flow to INI, setting pif[INISIDE]
  * @flow:	Flow to change state
diff --git a/flow.h b/flow.h
index d167b65..24ba3ef 100644
--- a/flow.h
+++ b/flow.h
@@ -264,4 +264,11 @@ void flow_log_(const struct flow_common *f, int pri, const char *fmt, ...)
 			flow_dbg((f), __VA_ARGS__);			\
 	} while (0)
 
+void flow_log_details_(const struct flow_common *f, int pri,
+		       enum flow_state state);
+#define flow_log_details(f_, pri) \
+	flow_log_details_(&((f_)->f), (pri), (f_)->f.state)
+#define flow_dbg_details(f_)	flow_log_details((f_), LOG_DEBUG)
+#define flow_err_details(f_)	flow_log_details((f_), LOG_ERR)
+
 #endif /* FLOW_H */