radius: implement jitter of accounting update interval

6 files changed, 35 insertions, 2 deletions

diff --git a/accel-pppd/accel-ppp.conf b/accel-pppd/accel-ppp.conf
index 144bf1f4..1635e177 100644
--- a/accel-pppd/accel-ppp.conf
+++ b/accel-pppd/accel-ppp.conf
@@ -209,6 +209,8 @@ verbose=1
 #acct-timeout=120
 #acct-delay-time=0
 #acct-on=0
+#acct-interim-interval=0
+#acct-interim-jitter=0
 #attr-tunnel-type=My-Tunnel-Type
 
 [client-ip-range]
diff --git a/accel-pppd/accel-ppp.conf.5 b/accel-pppd/accel-ppp.conf.5
index 3e6312f8..41ee09c5 100644
--- a/accel-pppd/accel-ppp.conf.5
+++ b/accel-pppd/accel-ppp.conf.5
@@ -838,6 +838,9 @@ Specifies secret to use in DM/CoA communication.
 .BI "acct-interim-interval=" n
 Specifies interval in seconds to send accounting information (may be overriden by radius Acct-Interim-Interval attribute)
 .TP
+.BI "acct-interim-jitter=" n
+Specifies absolute maximum jitter value in seconds to be applied to accounting information interval.
+.TP
 .BI "verbose=" n
 If this option is given and 
 .B n
diff --git a/accel-pppd/radius/acct.c b/accel-pppd/radius/acct.c
index c0b01900..9300bcb8 100644
--- a/accel-pppd/radius/acct.c
+++ b/accel-pppd/radius/acct.c
@@ -18,6 +18,10 @@
 
 #include "memdebug.h"
 
+#ifndef max
+#define max(x,y) ((x) > (y) ? (x) : (y))
+#endif
+
 #define INTERIM_SAFE_TIME 10
 
 static int req_set_RA(struct rad_req_t *req, const char *secret)
@@ -188,6 +192,12 @@ static void rad_acct_interim_update(struct triton_timer_t *t)
 	if (rad_req_send(rpd->acct_req) && conf_acct_timeout) {
 		log_ppp_warn("radius:acct: no servers available, terminating session...\n");
 		ap_session_terminate(rpd->ses, TERM_NAS_ERROR, 0);
+	} else if (rpd->acct_interim_interval && rpd->acct_interim_jitter) {
+		t->period = max(rpd->acct_interim_interval -
+					rpd->acct_interim_jitter, INTERIM_SAFE_TIME) * 1000;
+		t->period += ((rpd->acct_interim_interval +
+					rpd->acct_interim_jitter) * 1000 - t->period) * random() / RAND_MAX;
+		triton_timer_mod(t, 0);
 	}
 }
 
@@ -250,7 +260,13 @@ static void rad_acct_start_recv(struct rad_req_t *req)
 
 		rad_packet_change_val(req->pack, NULL, "Acct-Status-Type", "Interim-Update");
 		rpd->acct_interim_timer.expire = rad_acct_interim_update;
-		rpd->acct_interim_timer.period = rpd->acct_interim_interval * 1000;
+		if (rpd->acct_interim_jitter) {
+			rpd->acct_interim_timer.period = max(rpd->acct_interim_interval -
+						rpd->acct_interim_jitter, INTERIM_SAFE_TIME) * 1000;
+			rpd->acct_interim_timer.period += ((rpd->acct_interim_interval +
+						rpd->acct_interim_jitter) * 1000 - rpd->acct_interim_timer.period) * random() / RAND_MAX;
+		} else
+			rpd->acct_interim_timer.period = rpd->acct_interim_interval * 1000;
 		triton_timer_add(rpd->ses->ctrl->ctx, &rpd->acct_interim_timer, 0);
 
 		req->timeout.expire = rad_acct_timeout;
diff --git a/accel-pppd/radius/backup.c b/accel-pppd/radius/backup.c
index b73d3bab..6d4db636 100644
--- a/accel-pppd/radius/backup.c
+++ b/accel-pppd/radius/backup.c
@@ -44,6 +44,7 @@ static int session_save(struct ap_session *ses, struct backup_mod *m)
 	idle_timeout = rpd->idle_timeout.period / 1000;
 
 	add_tag(RAD_TAG_INTERIM_INTERVAL, &rpd->acct_interim_interval, 4);
+	add_tag(RAD_TAG_INTERIM_JITTER, &rpd->acct_interim_jitter, 4);
 
 	if (rpd->session_timeout.tpd)
 		add_tag(RAD_TAG_SESSION_TIMEOUT, &session_timeout, 8);
@@ -122,6 +123,9 @@ void radius_restore_session(struct ap_session *ses, struct radius_pd_t *rpd)
 			case RAD_TAG_INTERIM_INTERVAL:
 				rpd->acct_interim_interval = *(uint32_t *)tag->data;
 				break;
+			case RAD_TAG_INTERIM_JITTER:
+				rpd->acct_interim_jitter = *(uint32_t *)tag->data;
+				break;
 			case RAD_TAG_SESSION_TIMEOUT:
 				rpd->session_timeout.expire_tv.tv_sec = *(uint64_t *)tag->data - ses->start_time;
 				break;
diff --git a/accel-pppd/radius/radius.c b/accel-pppd/radius/radius.c
index 7cb01d80..e5a65a56 100644
--- a/accel-pppd/radius/radius.c
+++ b/accel-pppd/radius/radius.c
@@ -41,6 +41,7 @@ char *conf_dm_coa_secret;
 int conf_sid_in_auth;
 int conf_require_nas_ident;
 int conf_acct_interim_interval;
+int conf_acct_interim_jitter;
 
 int conf_accounting;
 int conf_fail_time;
@@ -277,6 +278,7 @@ int rad_proc_attrs(struct rad_req_t *req)
 	struct radius_pd_t *rpd = req->rpd;
 
 	req->rpd->acct_interim_interval = conf_acct_interim_interval;
+	req->rpd->acct_interim_jitter = conf_acct_interim_jitter;
 
 	list_for_each_entry(attr, &req->reply->attrs, entry) {
 		if (attr->vendor && attr->vendor->id == Vendor_Microsoft) {
@@ -969,9 +971,13 @@ static int load_config(void)
 		conf_require_nas_ident = atoi(opt);
 
 	opt = conf_get_opt("radius", "acct-interim-interval");
-	if (opt && atoi(opt) > 0)
+	if (opt && atoi(opt) >= 0)
 		conf_acct_interim_interval = atoi(opt);
 
+	opt = conf_get_opt("radius", "acct-interim-jitter");
+	if (opt && atoi(opt) >= 0)
+		conf_acct_interim_jitter = atoi(opt);
+
 	opt = conf_get_opt("radius", "acct-delay-time");
 	if (opt)
 		conf_acct_delay_time = atoi(opt);
diff --git a/accel-pppd/radius/radius_p.h b/accel-pppd/radius/radius_p.h
index 172504cf..0c185d28 100644
--- a/accel-pppd/radius/radius_p.h
+++ b/accel-pppd/radius/radius_p.h
@@ -66,6 +66,7 @@ struct radius_pd_t {
 	struct ipv6db_item_t ipv6_addr;
 	struct ipv6db_prefix_t ipv6_dp;
 	int acct_interim_interval;
+	int acct_interim_jitter;
 
 	char *acct_username;
 	uint8_t *attr_class;
@@ -185,6 +186,7 @@ extern int conf_require_nas_ident;
 extern in_addr_t conf_dm_coa_server;
 extern int conf_dm_coa_port;
 extern int conf_acct_interim_interval;
+extern int conf_acct_interim_jitter;
 extern int conf_accounting;
 extern const char *conf_attr_tunnel_type;