BSSMAP RESET: generalize a_reset FSM

Separate the a_reset FSM implementation from BSSMAP and MSC specifics, so that
it can be re-used on the Lb interface.

Move the FSM implementation to bssmap_reset.c and tweak, to match common practices we
have generally established in our osmo_fsm implementations.

Keep a_reset.h and a_reset.c and redirect to bssmap_reset.c.

A difficulty is setting a proper logging category: the FSM definition allows
only one fixed logging category for FSM state transitions and events. Ideally,
the BSSMAP reset fsm would log on DMSC, and the BSSMAP-LE reset fsm would log
on DLCS. Since that is not possible, introduce a separate DRESET logging
category. This in fact matches an item on my wishlist, because if a given MSC
is configured but currently not connected, the previous RESET FSM would
continuously "spam" log LOGL_NOTICE messages indicating that it is resending
RESET, and I often want to silence those messages without silencing the entire
DMSC category. This is now easily possible by setting DRESET logging to
LOGL_ERROR. There is additional "link up" / "link lost" logging on DMSC, so all
interesting info is still visible on DMSC.

Change-Id: Ib3c3a163186c40a93be0dea666230431172136df

1 files changed, 5 insertions, 0 deletions

diff --git a/src/osmo-bsc/osmo_bsc_main.c b/src/osmo-bsc/osmo_bsc_main.c
index 26d32d14e..35ddbbf78 100644
--- a/src/osmo-bsc/osmo_bsc_main.c
+++ b/src/osmo-bsc/osmo_bsc_main.c
@@ -795,6 +795,11 @@ static const struct log_info_cat osmo_bsc_categories[] = {
 		.description = "Location Services",
 		.enabled = 1, .loglevel = LOGL_NOTICE,
 	},
+	[DRESET] = {
+		.name = "DRESET",
+		.description = "RESET/ACK on A and Lb interfaces",
+		.enabled = 1, .loglevel = LOGL_NOTICE,
+	},
 };
 
 static int filter_fn(const struct log_context *ctx, struct log_target *tar)