client: Introduce FSMs for managing connections to server + bankd

Change-Id: I705d2dde6d7285bbb1be328181c6d09bccaf26fb

4 files changed, 386 insertions, 59 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 5d97b6d..2324831 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -23,6 +23,6 @@ remsim_bankd_SOURCES = bankd_slotmap.c bankd_main.c
 remsim_bankd_LDADD = $(OSMOCORE_LIBS) \
 		     $(ASN1C_LIBS) $(PCSC_LIBS) libosmo-rspro.la
 
-remsim_client_SOURCES = remsim_client.c
+remsim_client_SOURCES = remsim_client.c remsim_client_fsm.c
 remsim_client_LDADD = $(OSMOCORE_LIBS) $(OSMOGSM_LIBS) $(OSMOABIS_LIBS) \
 		     $(ASN1C_LIBS) libosmo-rspro.la
diff --git a/src/client.h b/src/client.h
new file mode 100644
index 0000000..3046f8b
--- /dev/null
+++ b/src/client.h
@@ -0,0 +1,49 @@
+#pragma once
+
+#include <osmocom/core/fsm.h>
+#include <osmocom/abis/ipa.h>
+
+#include "rspro_util.h"
+
+enum {
+	DMAIN,
+};
+
+/* fsm.c */
+
+enum bankd_conn_fsm_event {
+	BDC_E_TCP_UP,
+	BDC_E_TCP_DOWN,
+	BDC_E_CLIENT_CONN_RES,
+};
+
+
+enum server_conn_fsm_event {
+	SRVC_E_TCP_UP,
+	SRVC_E_TCP_DOWN,
+	SRVC_E_CLIENT_CONN_RES,
+};
+
+extern struct osmo_fsm remsim_client_bankd_fsm;
+extern struct osmo_fsm remsim_client_server_fsm;
+
+/* main.c */
+
+struct bankd_client {
+	/* connection to the remsim-server (control) */
+	struct ipa_client_conn *srv_conn;
+	struct osmo_fsm_inst *srv_fi;
+
+	/* our own component ID */
+	struct app_comp_id own_comp_id;
+
+	/* connection to the remsim-bankd */
+	char *bankd_host;
+	uint16_t bankd_port;
+	struct ipa_client_conn *bankd_conn;
+	struct osmo_fsm_inst *bankd_fi;
+};
+
+void bankd_send_rspro(struct bankd_client *bc, RsproPDU_t *rspro);
+int bankd_read_cb(struct ipa_client_conn *conn, struct msgb *msg);
+int bankd_conn_fsm_alloc(struct bankd_client *bc);
diff --git a/src/remsim_client.c b/src/remsim_client.c
index 7701dd4..0189f59 100644
--- a/src/remsim_client.c
+++ b/src/remsim_client.c
@@ -14,20 +14,7 @@
 #include <osmocom/gsm/protocol/ipaccess.h>
 
 #include "rspro_util.h"
-
-struct bankd_client {
-	/* connection to the remsim-server (control) */
-	struct ipa_client_conn *srv_conn;
-
-	/* our own component ID */
-	struct app_comp_id own_comp_id;
-
-	/* connection to the remsim-bankd */
-	char *bankd_host;
-	uint16_t bankd_port;
-	struct ipa_client_conn *bankd_conn;
-};
-
+#include "client.h"
 
 static void bankd_send(struct bankd_client *bc, struct msgb *msg_tx)
 {
@@ -37,43 +24,38 @@ static void bankd_send(struct bankd_client *bc, struct msgb *msg_tx)
 	/* msg_tx is now queued and will be freed. */
 }
 
-static void bankd_send_rspro(struct bankd_client *bc, RsproPDU_t *rspro)
+void bankd_send_rspro(struct bankd_client *bc, RsproPDU_t *rspro)
 {
 	struct msgb *msg = rspro_enc_msg(rspro);
 	OSMO_ASSERT(msg);
 	bankd_send(bc, msg);
 }
 
-
-
-
-
-
-
-
-
-
-
-
-static void bankd_updown_cb(struct ipa_client_conn *conn, int up)
+static int bankd_handle_msg(struct bankd_client *bc, struct msgb *msg)
 {
-	struct bankd_client *bc = conn->data;
+	RsproPDU_t *pdu = rspro_dec_msg(msg);
+	if (!pdu) {
+		fprintf(stderr, "Error decoding PDU\n");
+		return -1;
+	}
 
-	printf("RSPRO link to %s:%d %s\n", conn->addr, conn->port, up ? "UP" : "DOWN");
-	if (!up)
-		exit(3);
-	else {
-		const ClientSlot_t clslot = { .clientId = 23, .slotNr = 1 };
-		RsproPDU_t *pdu = rspro_gen_ConnectClientReq(&bc->own_comp_id, &clslot);
-		bankd_send_rspro(bc, pdu);
+	switch (pdu->msg.present) {
+	case RsproPDUchoice_PR_connectClientRes:
+		break;
+	default:
+		fprintf(stderr, "Unknown/Unsuppoerted RSPRO PDU: %s\n", msgb_hexdump(msg));
+		return -1;
 	}
+
+	return 0;
 }
 
-static int bankd_read_cb(struct ipa_client_conn *conn, struct msgb *msg)
+int bankd_read_cb(struct ipa_client_conn *conn, struct msgb *msg)
 {
 	struct ipaccess_head *hh = (struct ipaccess_head *) msg->data;
 	struct ipaccess_head_ext *he = (struct ipaccess_head_ext *) msgb_l2(msg);
 	struct bankd_client *bc = conn->data;
+	int rc;
 
 	if (msgb_length(msg) < sizeof(*hh))
 		goto invalid;
@@ -87,11 +69,12 @@ static int bankd_read_cb(struct ipa_client_conn *conn, struct msgb *msg)
 	if (he->proto != IPAC_PROTO_EXT_RSPRO)
 		goto invalid;
 
-	/* FIXME: do something */
 	printf("Received RSPRO %s\n", msgb_hexdump(msg));
 
+	rc = bankd_handle_msg(bc, msg);
 	msgb_free(msg);
-	return 0;
+
+	return rc;
 
 invalid:
 	msgb_free(msg);
@@ -99,6 +82,11 @@ invalid:
 }
 
 static const struct log_info_cat default_categories[] = {
+	[DMAIN] = {
+		.name = "DMAIN",
+		.loglevel = LOGL_DEBUG,
+		.enabled = 1,
+	},
 };
 
 static const struct log_info log_info = {
@@ -106,41 +94,33 @@ static const struct log_info log_info = {
 	.num_cat = ARRAY_SIZE(default_categories),
 };
 
-static struct bankd_client g_client;
+static struct bankd_client *g_client;
 static void *g_tall_ctx;
 void __thread *talloc_asn1_ctx;
 extern int asn_debug;
 
 int main(int argc, char **argv)
 {
-	int rc;
-
 	g_tall_ctx = talloc_named_const(NULL, 0, "global");
 
-	g_client.bankd_host = "localhost";
-	g_client.bankd_port = 9999;
-	g_client.own_comp_id.type = ComponentType_remsimClient;
-	OSMO_STRLCPY_ARRAY(g_client.own_comp_id.name, "fixme-name");
-	OSMO_STRLCPY_ARRAY(g_client.own_comp_id.software, "remsim-client");
-	OSMO_STRLCPY_ARRAY(g_client.own_comp_id.sw_version, PACKAGE_VERSION);
+	osmo_fsm_register(&remsim_client_bankd_fsm);
+	osmo_fsm_register(&remsim_client_server_fsm);
+
+	g_client = talloc_zero(g_tall_ctx, struct bankd_client);
+	g_client->bankd_host = "localhost";
+	g_client->bankd_port = 9999;
+	g_client->own_comp_id.type = ComponentType_remsimClient;
+	OSMO_STRLCPY_ARRAY(g_client->own_comp_id.name, "fixme-name");
+	OSMO_STRLCPY_ARRAY(g_client->own_comp_id.software, "remsim-client");
+	OSMO_STRLCPY_ARRAY(g_client->own_comp_id.sw_version, PACKAGE_VERSION);
 
 	//asn_debug = 1;
 	osmo_init_logging2(g_tall_ctx, &log_info);
 
-	g_client.bankd_conn = ipa_client_conn_create(g_tall_ctx, NULL, 0,
-						   g_client.bankd_host, g_client.bankd_port,
-						   bankd_updown_cb, bankd_read_cb,
-						   NULL, &g_client);
-	if (!g_client.bankd_conn) {
+	if (bankd_conn_fsm_alloc(g_client) < 0) {
 		fprintf(stderr, "Unable to connect: %s\n", strerror(errno));
 		exit(1);
 	}
-	rc = ipa_client_conn_open(g_client.bankd_conn);
-	if (rc < 0) {
-		fprintf(stderr, "Unable to connect RSPRO to %s:%d - %s\n",
-			g_client.bankd_conn->addr, g_client.bankd_conn->port, strerror(errno));
-		return 0;
-	}
 
 	while (1) {
 		osmo_select_main(0);
diff --git a/src/remsim_client_fsm.c b/src/remsim_client_fsm.c
new file mode 100644
index 0000000..89b95de
--- /dev/null
+++ b/src/remsim_client_fsm.c
@@ -0,0 +1,298 @@
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+
+#include <talloc.h>
+
+#include <osmocom/core/logging.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/fsm.h>
+
+#include <osmocom/abis/ipa.h>
+#include <osmocom/gsm/protocol/ipaccess.h>
+
+#include "client.h"
+#include "rspro_util.h"
+
+#define S(x)	(1 << (x))
+
+static void bankd_updown_cb(struct ipa_client_conn *conn, int up)
+{
+	struct bankd_client *bc = conn->data;
+
+	printf("RSPRO link to %s:%d %s\n", conn->addr, conn->port, up ? "UP" : "DOWN");
+
+	osmo_fsm_inst_dispatch(bc->bankd_fi, up ? BDC_E_TCP_UP: BDC_E_TCP_DOWN, 0);
+}
+
+/***********************************************************************
+ * bankd connection FSM
+ ***********************************************************************/
+
+enum bankd_conn_fsm_state {
+	/* waiting for initial connectiong to remsim-bankd */
+	BDC_ST_INIT,
+	/* bankd connection established, waiting for ClientConnectRes */
+	BDC_ST_ESTABLISHED,
+	/* bankd connection etsablished, ClientConnect succeeded */
+	BDC_ST_CONNECTED,
+	/* connection lost, we're waiting for a re-establish */
+	BDC_ST_REESTABLISH,
+};
+
+static const struct value_string remsim_client_bankd_fsm_event_names[] = {
+	OSMO_VALUE_STRING(BDC_E_TCP_UP),
+	OSMO_VALUE_STRING(BDC_E_TCP_DOWN),
+	OSMO_VALUE_STRING(BDC_E_CLIENT_CONN_RES),
+	{ 0, NULL }
+};
+
+#define T1_WAIT_CLIENT_CONN_RES		10
+#define T2_RECONNECT			10
+
+
+static void bdc_st_init_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+	struct bankd_client *bc = (struct bankd_client *) fi->priv;
+	int rc;
+
+	printf("onenter\n");
+	bc->bankd_conn = ipa_client_conn_create(bc, NULL, 0, bc->bankd_host, bc->bankd_port,
+						bankd_updown_cb, bankd_read_cb, NULL, bc);
+	if (!bc->bankd_conn) {
+		fprintf(stderr, "Unable to create socket: %s\n", strerror(errno));
+		exit(1);
+	}
+	/* Attempt to connect TCP socket */
+	rc = ipa_client_conn_open(bc->bankd_conn);
+	if (rc < 0) {
+		fprintf(stderr, "Unable to connect: %s\n", strerror(errno));
+		exit(1);
+	}
+}
+
+static void bdc_st_init(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	switch (event) {
+	case BDC_E_TCP_UP:
+		osmo_fsm_inst_state_chg(fi, BDC_ST_ESTABLISHED, T1_WAIT_CLIENT_CONN_RES, 1);
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+static void bdc_st_established_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+	struct bankd_client *bc = (struct bankd_client *) fi->priv;
+	RsproPDU_t *pdu;
+
+	/* FIXME: Send ClientConnReq */
+	const ClientSlot_t clslot = { .clientId = 23, .slotNr = 1 };
+	pdu = rspro_gen_ConnectClientReq(&bc->own_comp_id, &clslot);
+	bankd_send_rspro(bc, pdu);
+}
+
+static void bdc_st_established(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	switch (event) {
+	case BDC_E_TCP_DOWN:
+		osmo_fsm_inst_state_chg(fi, BDC_ST_REESTABLISH, T2_RECONNECT, 2);
+		break;
+	case BDC_E_CLIENT_CONN_RES:
+		/* somehow notify the main code? */
+		osmo_fsm_inst_state_chg(fi, BDC_ST_CONNECTED, 0, 0);
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+static void bdc_st_connected(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	switch (event) {
+	case BDC_E_TCP_DOWN:
+		osmo_fsm_inst_state_chg(fi, BDC_ST_REESTABLISH, T2_RECONNECT, 2);
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+static void bdc_st_reestablish_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
+{
+	struct bankd_client *bc = (struct bankd_client *) fi->priv;
+	int rc;
+
+	/* Attempt to connect TCP socket */
+	rc = ipa_client_conn_open(bc->bankd_conn);
+	if (rc < 0) {
+		fprintf(stderr, "Unable to connect RSPRO to %s:%d - %s\n",
+			bc->bankd_conn->addr, bc->bankd_conn->port, strerror(errno));
+		/* FIXME: retry? Timer? Abort? */
+		OSMO_ASSERT(0);
+	}
+}
+
+static void bdc_st_reestablish(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+	switch (event) {
+	case BDC_E_TCP_UP:
+		osmo_fsm_inst_state_chg(fi, BDC_ST_ESTABLISHED, T1_WAIT_CLIENT_CONN_RES, 1);
+		break;
+	default:
+		OSMO_ASSERT(0);
+	}
+}
+
+static int remsim_client_bankd_fsm_timer_cb(struct osmo_fsm_inst *fi)
+{
+	return 0;
+}
+
+static const struct osmo_fsm_state bankd_conn_fsm_states[] = {
+	[BDC_ST_INIT] = {
+		.name = "INIT",
+		.in_event_mask = S(BDC_E_TCP_UP),
+		.out_state_mask = S(BDC_ST_ESTABLISHED),
+		.action = bdc_st_init,
+	},
+	[BDC_ST_ESTABLISHED] = {
+		.name = "ESTABLISHED",
+		.in_event_mask = S(BDC_E_TCP_DOWN) | S(BDC_E_CLIENT_CONN_RES),
+		.out_state_mask = S(BDC_ST_CONNECTED) | S(BDC_ST_REESTABLISH),
+		.action = bdc_st_established,
+		.onenter = bdc_st_established_onenter,
+	},
+	[BDC_ST_CONNECTED] = {
+		.name = "CONNECTED",
+		.in_event_mask = S(BDC_E_TCP_DOWN),
+		.out_state_mask = S(BDC_ST_REESTABLISH),
+		.action = bdc_st_connected,
+	},
+	[BDC_ST_REESTABLISH] = {
+		.name = "REESTABLISH",
+		.in_event_mask = S(BDC_E_TCP_UP),
+		.out_state_mask = S(BDC_ST_ESTABLISHED),
+		.action = bdc_st_reestablish,
+		.onenter = bdc_st_reestablish_onenter,
+	},
+};
+
+struct osmo_fsm remsim_client_bankd_fsm = {
+	.name = "BANKD_CONN",
+	.states = bankd_conn_fsm_states,
+	.num_states = ARRAY_SIZE(bankd_conn_fsm_states),
+	.timer_cb = remsim_client_bankd_fsm_timer_cb,
+	.log_subsys = DMAIN,
+	.event_names = remsim_client_bankd_fsm_event_names,
+};
+
+int bankd_conn_fsm_alloc(struct bankd_client *bc)
+{
+	struct osmo_fsm_inst *fi;
+
+	fi = osmo_fsm_inst_alloc(&remsim_client_bankd_fsm, bc, bc, LOGL_DEBUG, "bankd");
+	if (!fi)
+		return -1;
+
+	bc->bankd_fi = fi;
+	/* onenter of the initial state is not automatically executed by osmo_fsm :( */
+	bdc_st_init_onenter(fi, 0);
+	return 0;
+}
+
+/***********************************************************************
+ * server connection FSM
+ ***********************************************************************/
+
+enum server_conn_fsm_state {
+	/* waiting for initial connectiong to remsim-server */
+	SRVC_ST_INIT,
+	/* server connection established, waiting for ClientConnectRes */
+	SRVC_ST_ESTABLISHED,
+	/* server connection etsablished, ClientConnect succeeded */
+	SRVC_ST_CONNECTED,
+	/* connection lost, we're waiting for a re-establish */
+	SRVC_ST_REESTABLISH,
+};
+
+static const struct value_string server_conn_fsm_event_names[] = {
+	OSMO_VALUE_STRING(SRVC_E_TCP_UP),
+	OSMO_VALUE_STRING(SRVC_E_TCP_DOWN),
+	OSMO_VALUE_STRING(SRVC_E_CLIENT_CONN_RES),
+	{ 0, NULL }
+};
+
+
+static void srvc_st_init(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+}
+
+static void srvc_st_established(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+}
+
+static void srvc_st_connected(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+}
+
+static void srvc_st_reestablish(struct osmo_fsm_inst *fi, uint32_t event, void *data)
+{
+}
+
+static int server_conn_fsm_timer_cb(struct osmo_fsm_inst *fi)
+{
+	return 0;
+}
+
+static const struct osmo_fsm_state server_conn_fsm_states[] = {
+	[SRVC_ST_INIT] = {
+		.name = "INIT",
+		.in_event_mask = S(SRVC_E_TCP_UP),
+		.out_state_mask = S(SRVC_ST_ESTABLISHED),
+		.action = srvc_st_init,
+	},
+	[SRVC_ST_ESTABLISHED] = {
+		.name = "ESTABLISHED",
+		.in_event_mask = S(SRVC_E_TCP_DOWN) | S(SRVC_E_CLIENT_CONN_RES),
+		.out_state_mask = S(SRVC_ST_CONNECTED) | S(SRVC_ST_REESTABLISH),
+		.action = srvc_st_established,
+	},
+	[SRVC_ST_CONNECTED] = {
+		.name = "CONNECTED",
+		.in_event_mask = S(SRVC_E_TCP_DOWN),
+		.out_state_mask = S(SRVC_ST_REESTABLISH),
+		.action = srvc_st_connected,
+	},
+	[SRVC_ST_REESTABLISH] = {
+		.name = "REESTABLISH",
+		.in_event_mask = S(SRVC_E_TCP_UP),
+		.out_state_mask = S(SRVC_ST_ESTABLISHED),
+		.action = srvc_st_reestablish,
+	},
+};
+
+struct osmo_fsm remsim_client_server_fsm = {
+	.name = "SERVER_CONN",
+	.states = server_conn_fsm_states,
+	.num_states = ARRAY_SIZE(server_conn_fsm_states),
+	.timer_cb = server_conn_fsm_timer_cb,
+	.log_subsys = DMAIN,
+	.event_names = server_conn_fsm_event_names,
+};
+
+int server_conn_fsm_alloc(struct bankd_client *bc)
+{
+	struct osmo_fsm_inst *fi;
+
+	fi = osmo_fsm_inst_alloc(&remsim_client_server_fsm, bc, bc, LOGL_DEBUG, "server");
+	if (!fi)
+		return -1;
+
+	bc->srv_fi = fi;
+	/* onenter of the initial state is not automatically executed by osmo_fsm :( */
+	///srvc_st_init_onenter(fi, 0);
+	return 0;
+}