[PATCH 2/4] flow: Include flow details with higher priority log messages

[David Gibson <david@gibson.dropbear.id.au>]

Currently flow_log() and related functions / macros have a 'details'
parameter which indicates whether to add extra messages with details of the
flow's addresses.  This is still a bit awkward to invoke, and only used in
a few places.  Change the logic, to automatically include the details if
and only if the log priority is greater than LOG_DEBUG.

Rationale:

If at debug log level, there are already a bunch of debug messages tracking
the flow life cycle, which include those details (we make sure to retain
those).  It's usually pretty easy to cross reference a specific flow debug
message with the flow's history including the details.

If at higher log level, and we generate a flow-connected error or warning
we don't have those life cycle messages.  So, just giving the flow index
doesn't really tell you anything about which flow tripped the error.
Adding the address details make the error message significantly more
useful.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 flow.c |  2 +-
 flow.h | 22 +++++++++++-----------
 udp.c  |  5 ++---
 3 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/flow.c b/flow.c
index 6cf3905a..dd92bad7 100644
--- a/flow.c
+++ b/flow.c
@@ -550,7 +550,7 @@ norule:
 	/* This shouldn't happen, because if there's no rule for it we should
 	 * have no listening socket that would let us get here
 	 */
-	flow_log(flow, LOG_DEBUG, false, true, "Missing forward rule");
+	flow_dbg(flow, "Missing forward rule");
 
 nofwd:
 	flow_err(flow, "No rules to forward %s %s [%s]:%hu -> [%s]:%hu",
diff --git a/flow.h b/flow.h
index d168a35a..e055defb 100644
--- a/flow.h
+++ b/flow.h
@@ -283,19 +283,19 @@ int flow_migrate_target(struct ctx *c, const struct migrate_stage *stage,
 void flow_log__(const struct flow_common *f, int pri, bool perror, bool details,
 		enum flow_state state, const char *fmt, ...);
 
-#define flow_log_(f_, pri_, perror_, details_, ...)			\
-	flow_log__((f_), (pri_), (perror_), (details_), (f_)->state,	\
-		   __VA_ARGS__)
+#define flow_log_(f_, pri_, perror_, ...)				\
+	flow_log__((f_), (pri_), (perror_), (pri_) > LOG_DEBUG,		\
+		   (f_)->state, __VA_ARGS__)
 
-#define flow_log(flow_, pri_, perror_, details_, ...)			\
-	flow_log_(&(flow_)->f, (pri_), (perror_), (details_), __VA_ARGS__)
+#define flow_log(flow_, pri_, perror_, ...)				\
+	flow_log_(&(flow_)->f, (pri_), (perror_), __VA_ARGS__)
 
 #define flow_dbg(flow_, ...)						\
-	flow_log((flow_), LOG_DEBUG, false, false, __VA_ARGS__)
+	flow_log((flow_), LOG_DEBUG, false, __VA_ARGS__)
 #define flow_warn(flow_, ...)						\
-	flow_log((flow_), LOG_WARNING, false, false, __VA_ARGS__)
+	flow_log((flow_), LOG_WARNING, false, __VA_ARGS__)
 #define flow_err(flow_, ...)						\
-	flow_log((flow_), LOG_ERR, false, false, __VA_ARGS__)
+	flow_log((flow_), LOG_ERR, false, __VA_ARGS__)
 #define flow_trace(flow_, ...)						\
 	do {								\
 		if (log_trace)						\
@@ -303,11 +303,11 @@ void flow_log__(const struct flow_common *f, int pri, bool perror, bool details,
 	} while (0)
 
 #define flow_dbg_perror(flow_, ...) \
-	flow_log((flow_), LOG_DEBUG, true, false, __VA_ARGS__)
+	flow_log((flow_), LOG_DEBUG, true, __VA_ARGS__)
 #define flow_warn_perror(flow_, ...) \
-	flow_log((flow_), LOG_WARNING, true, false, __VA_ARGS__)
+	flow_log((flow_), LOG_WARNING, true, __VA_ARGS__)
 #define flow_perror(flow_, ...) \
-	flow_log((flow_), LOG_ERR, true, false, __VA_ARGS__)
+	flow_log((flow_), LOG_ERR, true, __VA_ARGS__)
 
 #define flow_dbg_ratelimit(flow_, now_, ...)				\
 	logmsg_ratelimit(flow_dbg, debug, (now_), (flow_), __VA_ARGS__)
diff --git a/udp.c b/udp.c
index f29ca3da..caeedf8f 100644
--- a/udp.c
+++ b/udp.c
@@ -943,8 +943,7 @@ void udp_sock_handler(const struct ctx *c, union epoll_ref ref,
 
 	if (events & EPOLLERR) {
 		if (udp_sock_errs(c, ref.fd, ref.flowside, PIF_NONE, 0) < 0) {
-			flow_log(uflow, LOG_ERR, false, true,
-				 "Unrecoverable error on flow socket");
+			flow_err(uflow, "Unrecoverable error on flow socket");
 			goto fail;
 		}
 	}
@@ -975,7 +974,7 @@ void udp_sock_handler(const struct ctx *c, union epoll_ref ref,
 				udp_buf_sock_to_tap(c, s, n, tosidx);
 			}
 		} else {
-			flow_log(uflow, LOG_ERR, false, true,
+			flow_err(uflow,
 				 "No support for forwarding UDP from %s to %s",
 				 pif_name(pif_at_sidx(ref.flowside)),
 				 pif_name(topif));
-- 
2.54.0