sgsn: Create an initial and limited CDR module

This is consuming the new signals and allows to install several
different CDR/observing/event/audit modules in the future. For
getting the bytes in/out the code would have had to undo what the
rate counter is doing and at the same time adding a "total" to
the ratecounter didn't look like a good idea, the same went for
making it a plain counter.

Begin writing the values one by one and open/closing a new FILE
for every log messages. This is not efficient but easily deals
with external truncation/rotation of the file (no fstat for and
checking the links and size). As usual we will wait and see if
this is an issue.

Add some new members to our PDP context structure to see what it
is about.

1 files changed, 254 insertions, 0 deletions

diff --git a/openbsc/src/gprs/sgsn_cdr.c b/openbsc/src/gprs/sgsn_cdr.c
new file mode 100644
index 000000000..0fcdd3b2a
--- /dev/null
+++ b/openbsc/src/gprs/sgsn_cdr.c
@@ -0,0 +1,254 @@
+/* GPRS SGSN CDR dumper */
+
+/* (C) 2015 by Holger Hans Peter Freyther
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <openbsc/sgsn.h>
+#include <openbsc/signal.h>
+#include <openbsc/gprs_utils.h>
+#include <openbsc/debug.h>
+
+#include <openbsc/vty.h>
+
+#include <gtp.h>
+#include <pdp.h>
+
+#include <arpa/inet.h>
+
+#include <time.h>
+
+#include <stdio.h>
+#include <inttypes.h>
+
+/* TODO...avoid going through a global */
+extern struct sgsn_instance *sgsn;
+
+/**
+ * The CDR module will generate an entry like:
+ *
+ * IMSI, # Subscriber IMSI
+ * IMEI, # Subscriber IMEI
+ * MSISDN, # Subscriber MISDN
+ * Charging_Timestamp, # Event start Time
+ * Charging_UTC, # Time zone of event start time
+ * Duration, # Session DURATION
+ * Cell_Id, # CELL_ID
+ * Location_Area, # LAC
+ * GGSN_ADDR, # GGSN_ADDR
+ * SGSN_ADDR, # SGSN_ADDR
+ * APNI, # APNI
+ * PDP_ADDR, # PDP_ADDR
+ * VOL_IN, # VOL_IN in Bytes
+ * VOL_OUT, # VOL_OUT in Bytes
+ * CAUSE_FOR_TERM, # CAUSE_FOR_TERM
+ */
+
+
+static void maybe_print_header(FILE *cdr_file)
+{
+	if (ftell(cdr_file) != 0)
+		return;
+
+	fprintf(cdr_file, "timestamp,imsi,imei,msisdn,cell_id,lac,event,pdp_duration,ggsn_addr,sgsn_addr,apni,eua_addr,vol_in,vol_out\n");
+}
+
+static void cdr_log_mm(struct sgsn_instance *inst, const char *ev,
+			struct sgsn_mm_ctx *mmctx)
+{
+	FILE *cdr_file;
+	struct tm tm;
+	struct timeval tv;
+
+	if (!inst->cfg.cdr.filename)
+		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);
+	gettimeofday(&tv, NULL);
+	gmtime_r(&tv.tv_sec, &tm);
+	fprintf(cdr_file, "%04d%02d%02d%02d%02d%02d%03d,%s,%s,%s,%d,%d,%s\n",
+		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+		tm.tm_hour, tm.tm_min, tm.tm_sec,
+		(int)(tv.tv_usec / 1000),
+		mmctx->imsi,
+		mmctx->imei,
+		mmctx->msisdn,
+		mmctx->cell_id,
+		mmctx->ra.lac,
+		ev);
+
+	fclose(cdr_file);
+}
+
+static void extract_eua(struct ul66_t *eua, char *eua_addr)
+{
+	if (eua->l < 2)
+		return;
+
+	/* there is no addr for ETSI/PPP */
+	if ((eua->v[0] & 0x0F) != 1) {
+		strcpy(eua_addr, "ETSI");
+		return;
+	}
+
+	if (eua->v[1] == 0x21 && eua->l == 6)
+		inet_ntop(AF_INET, &eua->v[2], eua_addr, INET_ADDRSTRLEN);
+	else if (eua->v[1] == 0x57 && eua->l == 18)
+		inet_ntop(AF_INET6, &eua->v[2], eua_addr, INET6_ADDRSTRLEN);
+	else {
+		/* e.g. both IPv4 and IPv6 */
+		strcpy(eua_addr, "Unknown address");
+	}
+}
+
+static void cdr_log_pdp(struct sgsn_instance *inst, const char *ev,
+			struct sgsn_pdp_ctx *pdp)
+{
+	FILE *cdr_file;
+	char apni[(pdp->lib ? pdp->lib->apn_use.l : 0) + 1];
+	char ggsn_addr[INET_ADDRSTRLEN + 1];
+	char sgsn_addr[INET_ADDRSTRLEN + 1];
+	char eua_addr[INET6_ADDRSTRLEN + 1];
+	struct tm tm;
+	struct timeval tv;
+	time_t duration;
+	struct timespec tp;
+
+	if (!inst->cfg.cdr.filename)
+		return;
+
+	memset(apni, 0, sizeof(apni));
+	memset(ggsn_addr, 0, sizeof(ggsn_addr));
+	memset(eua_addr, 0, sizeof(eua_addr));
+
+
+	if (pdp->lib) {
+		gprs_apn_to_str(apni, pdp->lib->apn_use.v, pdp->lib->apn_use.l);
+		inet_ntop(AF_INET, &pdp->lib->hisaddr0.s_addr, ggsn_addr, sizeof(ggsn_addr));
+		extract_eua(&pdp->lib->eua, eua_addr);
+	}
+
+	if (pdp->ggsn)
+		inet_ntop(AF_INET, &pdp->ggsn->gsn->gsnc.s_addr, sgsn_addr, sizeof(sgsn_addr));
+
+	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);
+
+	clock_gettime(CLOCK_MONOTONIC, &tp);
+	gettimeofday(&tv, NULL);
+
+	/* convert the timestamp to UTC */
+	gmtime_r(&tv.tv_sec, &tm);
+
+	/* Check the duration of the PDP context */
+	duration = tp.tv_sec - pdp->cdr_start.tv_sec;
+
+	fprintf(cdr_file,
+		"%04d%02d%02d%02d%02d%02d%03d,%s,%s,%s,%d,%d,%s,%ld,%s,%s,%s,%s,%" PRIu64 ",%" PRIu64 "\n",
+		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+		tm.tm_hour, tm.tm_min, tm.tm_sec,
+		(int)(tv.tv_usec / 1000),
+		pdp->mm ? pdp->mm->imsi : "N/A",
+		pdp->mm ? pdp->mm->imei : "N/A",
+		pdp->mm ? pdp->mm->msisdn : "N/A",
+		pdp->mm ? pdp->mm->cell_id : -1,
+		pdp->mm ? pdp->mm->ra.lac : -1,
+		ev,
+		(unsigned long ) duration,
+		ggsn_addr,
+		sgsn_addr,
+		apni,
+		eua_addr,
+		pdp->cdr_bytes_in,
+		pdp->cdr_bytes_out);
+	fclose(cdr_file);
+}
+
+static void cdr_pdp_timeout(void *_data)
+{
+	struct sgsn_pdp_ctx *pdp = _data;
+	cdr_log_pdp(sgsn, "pdp-periodic", pdp);
+	osmo_timer_schedule(&pdp->cdr_timer, sgsn->cfg.cdr.interval, 0);
+}
+
+static int handle_sgsn_sig(unsigned int subsys, unsigned int signal,
+			void *handler_data, void *_signal_data)
+{
+	struct sgsn_signal_data *signal_data = _signal_data;
+	struct sgsn_instance *inst = handler_data;
+
+	if (subsys != SS_SGSN)
+		return 0;
+
+	switch (signal) {
+	case S_SGSN_ATTACH:
+		cdr_log_mm(inst, "attach", signal_data->mm);
+		break;
+	case S_SGSN_UPDATE:
+		cdr_log_mm(inst, "update", signal_data->mm);
+		break;
+	case S_SGSN_DETACH:
+		cdr_log_mm(inst, "detach", signal_data->mm);
+		break;
+	case S_SGSN_MM_FREE:
+		cdr_log_mm(inst, "free", signal_data->mm);
+		break;
+	case S_SGSN_PDP_ACT:
+		clock_gettime(CLOCK_MONOTONIC, &signal_data->pdp->cdr_start);
+		cdr_log_pdp(inst, "pdp-act", signal_data->pdp);
+		signal_data->pdp->cdr_timer.cb = cdr_pdp_timeout;
+		signal_data->pdp->cdr_timer.data = signal_data->pdp;
+		osmo_timer_schedule(&signal_data->pdp->cdr_timer, inst->cfg.cdr.interval, 0);
+		break;
+	case S_SGSN_PDP_DEACT:
+		cdr_log_pdp(inst, "pdp-deact", signal_data->pdp);
+		osmo_timer_del(&signal_data->pdp->cdr_timer);
+		break;
+	case S_SGSN_PDP_TERMINATE:
+		cdr_log_pdp(inst, "pdp-terminate", signal_data->pdp);
+		osmo_timer_del(&signal_data->pdp->cdr_timer);
+		break;
+	case S_SGSN_PDP_FREE:
+		cdr_log_pdp(inst, "pdp-free", signal_data->pdp);
+		osmo_timer_del(&signal_data->pdp->cdr_timer);
+		break;
+	}
+
+	return 0;
+}
+
+int sgsn_cdr_init(struct sgsn_instance *sgsn)
+{
+	/* register for CDR related events */
+	sgsn->cfg.cdr.interval = 10 * 60;
+	osmo_signal_register_handler(SS_SGSN, handle_sgsn_sig, sgsn);
+
+	return 0;
+}