From a596ef53a689f0ecbf24d0043a4ad571cc8a4bf3 Mon Sep 17 00:00:00 2001
From: Dmitry Kozlov <xeb@mail.ru>
Date: Tue, 18 Apr 2017 20:47:53 +0300
Subject: implemented session count limiting

new config option:
[common]
max-sessions=N

If set then accel-pppd stops reply to new connection requests if total number of sessions (active and starting) is reached specified limit.
---
 accel-pppd/ctrl/ipoe/ipoe.c   | 9 +++++++++
 accel-pppd/ctrl/l2tp/l2tp.c   | 9 +++++++++
 accel-pppd/ctrl/pppoe/pppoe.c | 6 ++++++
 accel-pppd/ctrl/pptp/pptp.c   | 7 ++++++-
 4 files changed, 30 insertions(+), 1 deletion(-)

(limited to 'accel-pppd/ctrl')

diff --git a/accel-pppd/ctrl/ipoe/ipoe.c b/accel-pppd/ctrl/ipoe/ipoe.c
index b8aba6c9..7ac9f64a 100644
--- a/accel-pppd/ctrl/ipoe/ipoe.c
+++ b/accel-pppd/ctrl/ipoe/ipoe.c
@@ -1241,6 +1241,12 @@ static struct ipoe_session *ipoe_session_create_dhcpv4(struct ipoe_serv *serv, s
 	int dlen = 0;
 	uint8_t *ptr = NULL;
 
+	if (ap_shutdown)
+		return NULL;
+
+	if (conf_max_sessions && ap_session_stat.active + ap_session_stat.starting >= conf_max_sessions)
+		return NULL;
+
 	ses = ipoe_session_alloc(serv->ifname);
 	if (!ses)
 		return NULL;
@@ -1884,6 +1890,9 @@ static struct ipoe_session *ipoe_session_create_up(struct ipoe_serv *serv, struc
 	if (ap_shutdown)
 		return NULL;
 
+	if (conf_max_sessions && ap_session_stat.active + ap_session_stat.starting >= conf_max_sessions)
+		return NULL;
+
 	if (l4_redirect_list_check(saddr))
 		return NULL;
 
diff --git a/accel-pppd/ctrl/l2tp/l2tp.c b/accel-pppd/ctrl/l2tp/l2tp.c
index bb3df4d4..51f8e7dc 100644
--- a/accel-pppd/ctrl/l2tp/l2tp.c
+++ b/accel-pppd/ctrl/l2tp/l2tp.c
@@ -2737,6 +2737,9 @@ static int l2tp_recv_SCCRQ(const struct l2tp_serv_t *serv,
 		return 0;
 	}
 
+	if (conf_max_sessions && ap_session_stat.active + ap_session_stat.starting >= conf_max_sessions)
+		return 0;
+
 	if (triton_module_loaded("connlimit")
 	    && connlimit_check(cl_key_from_ipv4(pack->addr.sin_addr.s_addr))) {
 		log_warn("l2tp: connection limits reached,"
@@ -3263,6 +3266,9 @@ static int l2tp_recv_ICRQ(struct l2tp_conn_t *conn,
 		return 0;
 	}
 
+	if (conf_max_sessions && ap_session_stat.active + ap_session_stat.starting >= conf_max_sessions)
+		return 0;
+
 	if (triton_module_loaded("connlimit")
 	    && connlimit_check(cl_key_from_ipv4(conn->peer_addr.sin_addr.s_addr))) {
 		log_tunnel(log_warn, conn, "connection limits reached,"
@@ -3563,6 +3569,9 @@ static int l2tp_recv_OCRQ(struct l2tp_conn_t *conn,
 		return 0;
 	}
 
+	if (conf_max_sessions && ap_session_stat.active + ap_session_stat.starting >= conf_max_sessions)
+		return 0;
+
 	if (triton_module_loaded("connlimit")
 	    && connlimit_check(cl_key_from_ipv4(conn->peer_addr.sin_addr.s_addr))) {
 		log_tunnel(log_warn, conn, "connection limits reached,"
diff --git a/accel-pppd/ctrl/pppoe/pppoe.c b/accel-pppd/ctrl/pppoe/pppoe.c
index ff6b76f2..60d71276 100644
--- a/accel-pppd/ctrl/pppoe/pppoe.c
+++ b/accel-pppd/ctrl/pppoe/pppoe.c
@@ -950,6 +950,9 @@ static void pppoe_recv_PADI(struct pppoe_serv_t *serv, uint8_t *pack, int size)
 	if (ap_shutdown || pado_delay == -1)
 		return;
 
+	if (conf_max_sessions && ap_session_stat.active + ap_session_stat.starting >= conf_max_sessions)
+		return;
+
 	if (check_padi_limit(serv, ethhdr->h_source)) {
 		__sync_add_and_fetch(&stat_PADI_drop, 1);
 		if (conf_verbose) {
@@ -1069,6 +1072,9 @@ static void pppoe_recv_PADR(struct pppoe_serv_t *serv, uint8_t *pack, int size)
 	if (ap_shutdown)
 		return;
 
+	if (conf_max_sessions && ap_session_stat.active + ap_session_stat.starting >= conf_max_sessions)
+		return;
+
 	if (!memcmp(ethhdr->h_dest, bc_addr, ETH_ALEN)) {
 		if (conf_verbose)
 			log_warn("pppoe: discard PADR (destination address is broadcast)\n");
diff --git a/accel-pppd/ctrl/pptp/pptp.c b/accel-pppd/ctrl/pptp/pptp.c
index 4aba5767..99958cc8 100644
--- a/accel-pppd/ctrl/pptp/pptp.c
+++ b/accel-pppd/ctrl/pptp/pptp.c
@@ -648,9 +648,14 @@ static int pptp_connect(struct triton_md_handler_t *h)
 			continue;
 		}
 
+		if (conf_max_sessions && ap_session_stat.active + ap_session_stat.starting >= conf_max_sessions) {
+			close(sock);
+			continue;
+		}
+
 		if (triton_module_loaded("connlimit") && connlimit_check(cl_key_from_ipv4(addr.sin_addr.s_addr))) {
 			close(sock);
-			return 0;
+			continue;
 		}
 
 		log_info2("pptp: new connection from %s\n", inet_ntoa(addr.sin_addr));
-- 
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