stats/vty: Add stats configuration

This commit provides stats configuration similar to the log
configuration.

The following vty commands are added to the config node:
  stats reporter statsd          Create/Modify a statsd reporter
  no stats reporter statsd       Remove a statsd reporter

To actually configure a reporter, the config-stats node is entered
when the "stats reporter" command has succeeded. The following new
vty commands are available there:
  local-ip ADDR          Set the IP address to which we bind locally
  no local-ip            Do not bind to a certain IP address
  remote-ip ADDR         Set the remote IP address to which we connect
  remote-port <1-65535>  Set the remote port to which we connect
  prefix PREFIX          Set the item/counter name prefix
  no prefix              Do not use a prefix
  enable                 Enable the reporter
  disable                Disable the reporter

Sponsored-by: On-Waves ehf
diff --git a/src/vty/stats_vty.c b/src/vty/stats_vty.c
index c19b225..954f358 100644
--- a/src/vty/stats_vty.c
+++ b/src/vty/stats_vty.c
@@ -29,13 +29,209 @@
 #include <osmocom/vty/buffer.h>
 #include <osmocom/vty/vty.h>
 #include <osmocom/vty/telnet_interface.h>
+#include <osmocom/vty/telnet_interface.h>
 #include <osmocom/vty/misc.h>
 
+#include <osmocom/core/stats.h>
+
 #define CFG_STATS_STR "Configure stats sub-system\n"
 #define CFG_REPORTER_STR "Configure a stats reporter\n"
 
 #define SHOW_STATS_STR "Show statistical values\n"
 
+struct cmd_node cfg_stats_node = {
+	CFG_STATS_NODE,
+	"%s(config-stats)# ",
+	1
+};
+
+static struct stats_reporter *osmo_stats_vty2srep(struct vty *vty)
+{
+	if (vty->node == CFG_STATS_NODE)
+		return vty->index;
+
+	return NULL;
+}
+
+static int set_srep_parameter_str(struct vty *vty,
+	int (*fun)(struct stats_reporter *, const char *),
+	const char *val, const char *param_name)
+{
+	int rc;
+	struct stats_reporter *srep = osmo_stats_vty2srep(vty);
+	OSMO_ASSERT(srep);
+
+	rc = fun(srep, val);
+	if (rc < 0) {
+		vty_out(vty, "%% Unable to set %s: %s%s",
+			param_name, strerror(-rc), VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	return CMD_SUCCESS;
+}
+
+static int set_srep_parameter_int(struct vty *vty,
+	int (*fun)(struct stats_reporter *, int),
+	const char *val, const char *param_name)
+{
+	int rc;
+	int int_val;
+	struct stats_reporter *srep = osmo_stats_vty2srep(vty);
+	OSMO_ASSERT(srep);
+
+	int_val = atoi(val);
+
+	rc = fun(srep, int_val);
+	if (rc < 0) {
+		vty_out(vty, "%% Unable to set %s: %s%s",
+			param_name, strerror(-rc), VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_stats_reporter_local_ip, cfg_stats_reporter_local_ip_cmd,
+	"local-ip ADDR",
+	"Set the IP address to which we bind locally\n"
+	"IP Address\n")
+{
+	return set_srep_parameter_str(vty, stats_reporter_set_local_addr,
+		argv[0], "local address");
+}
+
+DEFUN(cfg_no_stats_reporter_local_ip, cfg_no_stats_reporter_local_ip_cmd,
+	"no local-ip",
+	NO_STR
+	"Set the IP address to which we bind locally\n")
+{
+	return set_srep_parameter_str(vty, stats_reporter_set_local_addr,
+		NULL, "local address");
+}
+
+DEFUN(cfg_stats_reporter_remote_ip, cfg_stats_reporter_remote_ip_cmd,
+	"remote-ip ADDR",
+	"Set the remote IP address to which we connect\n"
+	"IP Address\n")
+{
+	return set_srep_parameter_str(vty, stats_reporter_set_remote_addr,
+		argv[0], "remote address");
+}
+
+DEFUN(cfg_stats_reporter_remote_port, cfg_stats_reporter_remote_port_cmd,
+	"remote-port <1-65535>",
+	"Set the remote port to which we connect\n"
+	"Remote port number\n")
+{
+	return set_srep_parameter_int(vty, stats_reporter_set_remote_port,
+		argv[0], "remote port");
+}
+
+DEFUN(cfg_stats_reporter_interval, cfg_stats_reporter_interval_cmd,
+	"interval <1-65535>",
+	"Set the reporting interval\n"
+	"Interval in seconds\n")
+{
+	return set_srep_parameter_int(vty, stats_reporter_set_interval,
+		argv[0], "reporting interval");
+}
+
+DEFUN(cfg_stats_reporter_prefix, cfg_stats_reporter_prefix_cmd,
+	"prefix PREFIX",
+	"Set the item name prefix\n"
+	"The prefix string\n")
+{
+	return set_srep_parameter_str(vty, stats_reporter_set_name_prefix,
+		argv[0], "prefix string");
+}
+
+DEFUN(cfg_no_stats_reporter_prefix, cfg_no_stats_reporter_prefix_cmd,
+	"no prefix",
+	NO_STR
+	"Set the item name prefix\n")
+{
+	return set_srep_parameter_str(vty, stats_reporter_set_name_prefix,
+		"", "prefix string");
+}
+
+DEFUN(cfg_stats_reporter_enable, cfg_stats_reporter_enable_cmd,
+	"enable",
+	"Enable the reporter\n")
+{
+	int rc;
+	struct stats_reporter *srep = osmo_stats_vty2srep(vty);
+	OSMO_ASSERT(srep);
+
+	rc = stats_reporter_enable(srep);
+	if (rc < 0) {
+		vty_out(vty, "%% Unable to enable the reporter: %s%s",
+			strerror(-rc), VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_stats_reporter_disable, cfg_stats_reporter_disable_cmd,
+	"disable",
+	"Disable the reporter\n")
+{
+	int rc;
+	struct stats_reporter *srep = osmo_stats_vty2srep(vty);
+	OSMO_ASSERT(srep);
+
+	rc = stats_reporter_disable(srep);
+	if (rc < 0) {
+		vty_out(vty, "%% Unable to disable the reporter: %s%s",
+			strerror(-rc), VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_stats_reporter_statsd, cfg_stats_reporter_statsd_cmd,
+	"stats reporter statsd",
+	CFG_STATS_STR CFG_REPORTER_STR "Report to a STATSD server\n")
+{
+	struct stats_reporter *srep;
+
+	srep = stats_reporter_find(STATS_REPORTER_STATSD, NULL);
+	if (!srep) {
+		srep = stats_reporter_create_statsd(NULL);
+		if (!srep) {
+			vty_out(vty, "%% Unable to create statsd reporter%s",
+				VTY_NEWLINE);
+			return CMD_WARNING;
+		}
+		/* TODO: if needed, add stats_add_reporter(srep); */
+	}
+
+	vty->index = srep;
+	vty->node = CFG_STATS_NODE;
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_no_stats_reporter_statsd, cfg_no_stats_reporter_statsd_cmd,
+	"no stats reporter statsd",
+	NO_STR CFG_STATS_STR CFG_REPORTER_STR "Report to a STATSD server\n")
+{
+	struct stats_reporter *srep;
+
+	srep = stats_reporter_find(STATS_REPORTER_STATSD, NULL);
+	if (!srep) {
+		vty_out(vty, "%% No statsd logging active%s",
+			VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+
+	stats_reporter_free(srep);
+
+	return CMD_SUCCESS;
+}
+
 DEFUN(show_stats,
       show_stats_cmd,
       "show stats",
@@ -46,7 +242,70 @@
 	return CMD_SUCCESS;
 }
 
-void stats_vty_add_cmds(const struct log_info *cat)
+static int config_write_stats_reporter(struct vty *vty, struct stats_reporter *srep)
+{
+	if (srep == NULL)
+		return 0;
+
+	switch (srep->type) {
+	case STATS_REPORTER_STATSD:
+		vty_out(vty, "stats reporter statsd%s", VTY_NEWLINE);
+		break;
+	}
+
+	vty_out(vty, "  disable%s", VTY_NEWLINE);
+
+	if (srep->dest_addr_str)
+		vty_out(vty, "  remote-ip %s%s",
+			srep->dest_addr_str, VTY_NEWLINE);
+	if (srep->dest_port)
+		vty_out(vty, "  remote-port %d%s",
+			srep->dest_port, VTY_NEWLINE);
+	if (srep->bind_addr_str)
+		vty_out(vty, "  local-ip %s%s",
+			srep->bind_addr_str, VTY_NEWLINE);
+	if (srep->interval)
+		vty_out(vty, "  interval %d%s",
+			srep->interval, VTY_NEWLINE);
+	if (srep->name_prefix && *srep->name_prefix)
+		vty_out(vty, "  prefix %s%s",
+			srep->name_prefix, VTY_NEWLINE);
+	else
+		vty_out(vty, "  no prefix%s", VTY_NEWLINE);
+
+	if (srep->enabled)
+		vty_out(vty, "  enable%s", VTY_NEWLINE);
+
+	return 1;
+}
+
+static int config_write_stats(struct vty *vty)
+{
+	struct stats_reporter *srep;
+
+	srep = stats_reporter_find(STATS_REPORTER_STATSD, NULL);
+	config_write_stats_reporter(vty, srep);
+
+	return 1;
+}
+
+void stats_vty_add_cmds()
 {
 	install_element_ve(&show_stats_cmd);
+
+	install_element(CONFIG_NODE, &cfg_stats_reporter_statsd_cmd);
+	install_element(CONFIG_NODE, &cfg_no_stats_reporter_statsd_cmd);
+
+	install_node(&cfg_stats_node, config_write_stats);
+	vty_install_default(CFG_STATS_NODE);
+
+	install_element(CFG_STATS_NODE, &cfg_stats_reporter_local_ip_cmd);
+	install_element(CFG_STATS_NODE, &cfg_no_stats_reporter_local_ip_cmd);
+	install_element(CFG_STATS_NODE, &cfg_stats_reporter_remote_ip_cmd);
+	install_element(CFG_STATS_NODE, &cfg_stats_reporter_remote_port_cmd);
+	install_element(CFG_STATS_NODE, &cfg_stats_reporter_interval_cmd);
+	install_element(CFG_STATS_NODE, &cfg_stats_reporter_prefix_cmd);
+	install_element(CFG_STATS_NODE, &cfg_no_stats_reporter_prefix_cmd);
+	install_element(CFG_STATS_NODE, &cfg_stats_reporter_enable_cmd);
+	install_element(CFG_STATS_NODE, &cfg_stats_reporter_disable_cmd);
 }