Add vty cmd 'cdr trap' to send CDR through CTRL iface

Default behavior is to have them disabled, and can be explicitly
disabled too by using 'no cdr trap' cmd.

Tested with osmo_ctrl.py that messages are send successfully:
TRAP 0 cdr-v1 20171129125950222,901700000015254,357737055592090,555,0,5,,pdp-periodic,2731,127.0.0.2,127.0.0.1,internet,176.16.222.3,20793,10045,1

Related: OS#2360

Change-Id: I1d144d87effd934d991257a65e19cf046a938907
diff --git a/src/gprs/sgsn_cdr.c b/src/gprs/sgsn_cdr.c
index bc051ac..55aa664 100644
--- a/src/gprs/sgsn_cdr.c
+++ b/src/gprs/sgsn_cdr.c
@@ -18,6 +18,8 @@
  *
  */
 
+#include <osmocom/ctrl/control_if.h>
+
 #include <osmocom/sgsn/sgsn.h>
 #include <osmocom/sgsn/signal.h>
 #include <osmocom/sgsn/gprs_utils.h>
@@ -38,6 +40,7 @@
 
 /* TODO...avoid going through a global */
 extern struct sgsn_instance *sgsn;
+extern struct ctrl_handle *g_ctrlh;
 
 /**
  * The CDR module will generate an entry like:
@@ -59,6 +62,11 @@
  * CAUSE_FOR_TERM, # CAUSE_FOR_TERM
  */
 
+static void send_cdr_trap(char *value)
+{
+	if (ctrl_cmd_send_trap(g_ctrlh, "cdr-v1", value) < 0)
+		LOGP(DGPRS, LOGL_ERROR, "Failed to create and send TRAP cdr-v1\n");
+}
 
 static void maybe_print_header(FILE *cdr_file)
 {
@@ -97,21 +105,27 @@
 	FILE *cdr_file;
 	char buf[1024];
 
-	if (!inst->cfg.cdr.filename)
+	if (!inst->cfg.cdr.filename && !inst->cfg.cdr.trap)
 		return;
 
-	cdr_file = fopen(inst->cfg.cdr.filename, "a");
-	if (!cdr_file) {
-		LOGP(DGPRS, LOGL_ERROR, "Failed to open %s\n",
-			inst->cfg.cdr.filename);
-		return;
-	}
-
-	maybe_print_header(cdr_file);
 	cdr_snprintf_mm(buf, sizeof(buf), ev, mmctx);
-	fprintf(cdr_file, "%s\n", buf);
 
-	fclose(cdr_file);
+	if (inst->cfg.cdr.trap)
+		send_cdr_trap(buf);
+
+	if (inst->cfg.cdr.filename) {
+		cdr_file = fopen(inst->cfg.cdr.filename, "a");
+		if (!cdr_file) {
+			LOGP(DGPRS, LOGL_ERROR, "Failed to open %s\n",
+				inst->cfg.cdr.filename);
+			return;
+		}
+
+		maybe_print_header(cdr_file);
+		fprintf(cdr_file, "%s\n", buf);
+
+		fclose(cdr_file);
+	}
 }
 
 static void extract_eua(struct ul66_t *eua, char *eua_addr)
@@ -200,20 +214,26 @@
 	FILE *cdr_file;
 	char buf[1024];
 
-	if (!inst->cfg.cdr.filename)
+	if (!inst->cfg.cdr.filename && !inst->cfg.cdr.trap)
 		return;
 
-	cdr_file = fopen(inst->cfg.cdr.filename, "a");
-	if (!cdr_file) {
-		LOGP(DGPRS, LOGL_ERROR, "Failed to open %s\n",
-			inst->cfg.cdr.filename);
-		return;
-	}
-
-	maybe_print_header(cdr_file);
 	cdr_snprintf_pdp(buf, sizeof(buf), ev, pdp);
-	fprintf(cdr_file, "%s\n", buf);
-	fclose(cdr_file);
+
+	if (inst->cfg.cdr.trap)
+		send_cdr_trap(buf);
+
+	if (inst->cfg.cdr.filename) {
+		cdr_file = fopen(inst->cfg.cdr.filename, "a");
+		if (!cdr_file) {
+			LOGP(DGPRS, LOGL_ERROR, "Failed to open %s\n",
+				inst->cfg.cdr.filename);
+			return;
+		}
+
+		maybe_print_header(cdr_file);
+		fprintf(cdr_file, "%s\n", buf);
+		fclose(cdr_file);
+	}
 }
 
 static void cdr_pdp_timeout(void *_data)
diff --git a/src/gprs/sgsn_main.c b/src/gprs/sgsn_main.c
index fe4192b..b2a028c 100644
--- a/src/gprs/sgsn_main.c
+++ b/src/gprs/sgsn_main.c
@@ -76,6 +76,7 @@
 #include <getopt.h>
 
 void *tall_bsc_ctx;
+struct ctrl_handle *g_ctrlh;
 
 struct gprs_ns_inst *sgsn_nsi;
 static int daemonize = 0;
@@ -367,7 +368,6 @@
 
 int main(int argc, char **argv)
 {
-	struct ctrl_handle *ctrl;
 	int rc;
 #if BUILD_IU
 	struct osmo_sccp_instance *sccp;
@@ -454,9 +454,9 @@
 
 	/* start control interface after reading config for
 	 * ctrl_vty_get_bind_addr() */
-	ctrl = sgsn_controlif_setup(NULL, ctrl_vty_get_bind_addr(),
+	g_ctrlh = sgsn_controlif_setup(NULL, ctrl_vty_get_bind_addr(),
 				    OSMO_CTRL_PORT_SGSN);
-	if (!ctrl) {
+	if (!g_ctrlh) {
 		LOGP(DGPRS, LOGL_ERROR, "Failed to create CTRL interface.\n");
 		exit(1);
 	}
diff --git a/src/gprs/sgsn_vty.c b/src/gprs/sgsn_vty.c
index a01de2d..c8dfc43 100644
--- a/src/gprs/sgsn_vty.c
+++ b/src/gprs/sgsn_vty.c
@@ -233,6 +233,10 @@
 		vty_out(vty, " cdr filename %s%s", g_cfg->cdr.filename, VTY_NEWLINE);
 	else
 		vty_out(vty, " no cdr filename%s", VTY_NEWLINE);
+	if (g_cfg->cdr.trap)
+		vty_out(vty, " cdr trap%s", VTY_NEWLINE);
+	else
+		vty_out(vty, " no cdr trap%s", VTY_NEWLINE);
 	vty_out(vty, " cdr interval %d%s", g_cfg->cdr.interval, VTY_NEWLINE);
 
 	vty_out(vty, " timer t3312 %d%s", g_cfg->timers.T3312, VTY_NEWLINE);
@@ -1100,7 +1104,7 @@
 
 DEFUN(cfg_cdr_filename, cfg_cdr_filename_cmd,
 	"cdr filename NAME",
-	"CDR\nSet filename\nname\n")
+	"CDR\nEnable saving CDR to filename\nname\n")
 {
 	talloc_free(g_cfg->cdr.filename);
 	g_cfg->cdr.filename = talloc_strdup(tall_vty_ctx, argv[0]);
@@ -1109,13 +1113,29 @@
 
 DEFUN(cfg_no_cdr_filename, cfg_no_cdr_filename_cmd,
 	"no cdr filename",
-	NO_STR "CDR\nDisable CDR generation\n")
+	NO_STR "CDR\nDisable saving CDR to file\n")
 {
 	talloc_free(g_cfg->cdr.filename);
 	g_cfg->cdr.filename = NULL;
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_cdr_trap, cfg_cdr_trap_cmd,
+	"cdr trap",
+	"CDR\nEnable sending CDR via TRAP CTRL messages\n")
+{
+	g_cfg->cdr.trap = true;
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_no_cdr_trap, cfg_no_cdr_trap_cmd,
+	"no cdr trap",
+	NO_STR "CDR\nDisable sending CDR via TRAP CTRL messages\n")
+{
+	g_cfg->cdr.trap = false;
+	return CMD_SUCCESS;
+}
+
 DEFUN(cfg_cdr_interval, cfg_cdr_interval_cmd,
 	"cdr interval <1-2147483647>",
 	"CDR\nPDP periodic log interval\nSeconds\n")
@@ -1250,6 +1270,8 @@
 	install_element(SGSN_NODE, &cfg_no_apn_name_cmd);
 	install_element(SGSN_NODE, &cfg_cdr_filename_cmd);
 	install_element(SGSN_NODE, &cfg_no_cdr_filename_cmd);
+	install_element(SGSN_NODE, &cfg_cdr_trap_cmd);
+	install_element(SGSN_NODE, &cfg_no_cdr_trap_cmd);
 	install_element(SGSN_NODE, &cfg_cdr_interval_cmd);
 	install_element(SGSN_NODE, &cfg_ggsn_dynamic_lookup_cmd);
 	install_element(SGSN_NODE, &cfg_grx_ggsn_cmd);