mirror/rtbrick-bngblaster
1
0
Fork 0
mirror of https://github.com/rtbrick/bngblaster.git synced 2024-05-06 15:54:57 +00:00
Code Issues Projects Releases Wiki Activity

#3 L2TPv2 LNS Support (WIP) - 5

Browse Source
This commit is contained in:
Christian Giese
2021-02-19 13:40:40 +01:00
parent fbb3726be2
commit 67a40494ac
4 changed files with 131 additions and 28 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/bbl.h
+3 -2
View File
@@ -262,8 +262,9 @@ typedef struct bbl_interface_
uint64_t session_ipv6pd_wrong_session;
uint32_t l2tp_control_rx;
uint32_t l2tp_control_rx_dup;
uint32_t l2tp_control_rx_ooo;
uint32_t l2tp_control_rx_dup; /* duplicate */
uint32_t l2tp_control_rx_ooo; /* out of order */
uint32_t l2tp_control_rx_nf; /* session not found */
uint32_t l2tp_control_tx;
uint32_t l2tp_control_retry;
uint64_t l2tp_data_rx;
src/bbl_config.c
+14
View File
@@ -713,6 +713,20 @@ json_parse_config (json_t *root, bbl_ctx_s *ctx) {
} else {
l2tp_server->max_retry = 30;
}
if (json_unpack(sub, "{s:s}", "congestion-mode", &s) == 0) {
if (strcmp(s, "default") == 0) {
l2tp_server->congestion_mode = BBL_L2TP_CONGESTION_DEFAULT;
} else if (strcmp(s, "slow") == 0) {
l2tp_server->congestion_mode = BBL_L2TP_CONGESTION_SLOW;
} else if (strcmp(s, "aggressive") == 0) {
l2tp_server->congestion_mode = BBL_L2TP_CONGESTION_AGGRESSIVE;
} else {
fprintf(stderr, "Config error: Invalid value for l2tp-server->congestion-mode\n");
return false;
}
} else {
l2tp_server->congestion_mode = BBL_L2TP_CONGESTION_DEFAULT;
}
}
} else if (json_is_object(sub)) {
fprintf(stderr, "JSON config error: List expected in L2TP server configuration but dictionary found\n");
src/bbl_l2tp.c
+102 -23
View File
@@ -253,7 +253,7 @@ bbl_l2tp_tunnel_tx_job (timer_s *timer) {
if(q->last_tx_time.tv_sec) {
timespec_sub(&time_diff, &timestamp, &q->last_tx_time);
time_diff_ms = round(time_diff.tv_nsec / 1.0e6) * (time_diff.tv_sec * 1000);
if(time_diff_ms < 1000) {
if(time_diff_ms < (q->retries * 1000)) {
q = CIRCLEQ_NEXT(q, txq_qnode);
continue;
}
@@ -273,6 +273,14 @@ bbl_l2tp_tunnel_tx_job (timer_s *timer) {
bbl_l2tp_tunnel_update_state(l2tp_tunnel, BBL_L2TP_TUNNEL_SEND_STOPCCN);
bbl_l2tp_send(l2tp_tunnel, NULL, L2TP_MESSAGE_STOPCCN);
}
/* When congestion occurs (indicated by the triggering of a
* retransmission) one half of the congestion window (CWND)
* is saved in SSTHRESH, and CWND is set to one. The sender
* then reenters the slow start phase. */
l2tp_tunnel->ssthresh = l2tp_tunnel->cwnd/2;
if(!l2tp_tunnel->ssthresh) l2tp_tunnel->ssthresh = 1;
l2tp_tunnel->cwnd = 1;
l2tp_tunnel->cwcount = 0;
}
q->retries++;
q = CIRCLEQ_NEXT(q, txq_qnode);
@@ -332,7 +340,7 @@ bbl_l2tp_tunnel_control_job (timer_s *timer) {
break;
}
if(!l2tp_tunnel->timer_tx_active) {
timer_add(&ctx->timer_root, &l2tp_tunnel->timer_tx, "L2TP TX", 0, 10 * MSEC, l2tp_tunnel, bbl_l2tp_tunnel_tx_job);
timer_add(&ctx->timer_root, &l2tp_tunnel->timer_tx, "L2TP TX", 0, L2TP_TX_WAIT_MS * MSEC, l2tp_tunnel, bbl_l2tp_tunnel_tx_job);
l2tp_tunnel->timer_tx_active = true;
}
}
@@ -396,12 +404,7 @@ bbl_l2tp_send(bbl_l2tp_tunnel_t *l2tp_tunnel, bbl_l2tp_session_t *l2tp_session,
q->nr_offset = 52;
}
if(l2tp_type != L2TP_MESSAGE_ZLB) {
if(l2tp_tunnel->initial_packet_send) {
l2tp_tunnel->ns++;
} else{
l2tp_tunnel->initial_packet_send = true;
}
l2tp.ns = l2tp_tunnel->ns;
l2tp.ns = l2tp_tunnel->ns++;
bbl_l2tp_avp_encode_attributes(l2tp_tunnel, l2tp_session, l2tp_type, sp, &sp_len);
l2tp.payload = sp;
l2tp.payload_len = sp_len;
@@ -421,7 +424,7 @@ bbl_l2tp_send(bbl_l2tp_tunnel_t *l2tp_tunnel, bbl_l2tp_session_t *l2tp_session,
} else {
CIRCLEQ_INSERT_TAIL(&l2tp_tunnel->txq_qhead, q, txq_qnode);
if(!l2tp_tunnel->timer_tx_active) {
timer_add(&ctx->timer_root, &l2tp_tunnel->timer_tx, "L2TP TX", 0, 10 * MSEC, l2tp_tunnel, bbl_l2tp_tunnel_tx_job);
timer_add(&ctx->timer_root, &l2tp_tunnel->timer_tx, "L2TP TX", 0, L2TP_TX_WAIT_MS * MSEC, l2tp_tunnel, bbl_l2tp_tunnel_tx_job);
l2tp_tunnel->timer_tx_active = true;
}
}
@@ -742,6 +745,10 @@ bbl_l2tp_iccn_rx(bbl_ethernet_header_t *eth, bbl_l2tp_t *l2tp, bbl_interface_s *
UNUSED(eth);
UNUSED(l2tp);
if(!l2tp_session) {
return;
}
if(!bbl_l2tp_avp_decode_session(l2tp, l2tp_tunnel, l2tp_session)) {
bbl_l2tp_send(l2tp_tunnel, l2tp_session, L2TP_MESSAGE_CDN);
return bbl_l2tp_session_delete(l2tp_session);
@@ -765,6 +772,10 @@ bbl_l2tp_cdn_rx(bbl_ethernet_header_t *eth, bbl_l2tp_t *l2tp, bbl_interface_s *i
UNUSED(eth);
UNUSED(l2tp);
if(!l2tp_session) {
return;
}
bbl_l2tp_avp_decode_session(l2tp, l2tp_tunnel, l2tp_session);
l2tp_session->state = BBL_L2TP_SESSION_TERMINATED;
@@ -913,15 +924,26 @@ bbl_l2tp_handler_rx(bbl_ethernet_header_t *eth, bbl_l2tp_t *l2tp, bbl_interface_
key.tunnel_id = l2tp->tunnel_id;
key.session_id = l2tp->session_id;
search = dict_search(ctx->l2tp_session_dict, &key);
if(!search && l2tp->type && key.session_id != 0) {
/* Try with session zero (tunnel session) in case
* the corresponding session was already deleted.
* This is required for reliable delivery of control
* messages. */
key.session_id = 0;
search = dict_search(ctx->l2tp_session_dict, &key);
}
if(search) {
l2tp_session = *search;
l2tp_tunnel = l2tp_session->tunnel;
if(l2tp->type == L2TP_MESSAGE_DATA) {
/* L2TP Data Packet */
l2tp_tunnel->stats.data_rx++;
interface->stats.l2tp_data_rx++;
return bbl_l2tp_data_rx(eth, l2tp, interface, l2tp_session);
}
/* L2TP Control Packet */
l2tp_tunnel->stats.control_rx++;
interface->stats.l2tp_control_rx++;
if (L2TP_SEQ_GT(l2tp->nr, l2tp_tunnel->peer_nr)) {
l2tp_tunnel->peer_nr = l2tp->nr;
}
@@ -931,22 +953,58 @@ bbl_l2tp_handler_rx(bbl_ethernet_header_t *eth, bbl_l2tp_t *l2tp, bbl_interface_
l2tp_tunnel->server->host_name,
l2tp_message_string(l2tp->type),
format_ipv4_address(&ipv4->src));
/* Update tunnel */
l2tp_tunnel->peer_ns = l2tp->ns;
l2tp_tunnel->nr = (l2tp->ns + 1);
if(l2tp->type != L2TP_MESSAGE_ZLB) {
l2tp_tunnel->nr = (l2tp->ns + 1);
l2tp_tunnel->zlb = true;
/* Start tx timer */
if(!l2tp_tunnel->timer_tx_active) {
timer_add(&ctx->timer_root, &l2tp_tunnel->timer_tx, "L2TP TX", 0, L2TP_TX_WAIT_MS * MSEC, l2tp_tunnel, bbl_l2tp_tunnel_tx_job);
l2tp_tunnel->timer_tx_active = true;
}
}
if(l2tp_tunnel->cwnd < l2tp_tunnel->peer_receive_window) {
l2tp_tunnel->cwnd++;
}
l2tp_tunnel->stats.control_rx++;
interface->stats.l2tp_control_rx++;
if(!l2tp_tunnel->timer_tx_active) {
timer_add(&ctx->timer_root, &l2tp_tunnel->timer_tx, "L2TP TX", 0, 10 * MSEC, l2tp_tunnel, bbl_l2tp_tunnel_tx_job);
l2tp_tunnel->timer_tx_active = true;
/* Reliable Delivery of Control Messages */
switch (l2tp_tunnel->server->congestion_mode) {
case BBL_L2TP_CONGESTION_AGGRESSIVE:
l2tp_tunnel->cwnd = l2tp_tunnel->peer_receive_window;
break;
case BBL_L2TP_CONGESTION_SLOW:
l2tp_tunnel->cwnd = 1;
break;
default:
/* Adjust tunnel congestion window as defined
* in RFC 2661 Appendix A */
if(l2tp_tunnel->cwnd < l2tp_tunnel->peer_receive_window) {
if(l2tp_tunnel->cwnd < l2tp_tunnel->ssthresh) {
/* Slow Start Phase
*
* The congestion window (CWND) increases by 1
* for every new ACK received resulting in an
* exponential increase.
*/
l2tp_tunnel->cwcount = 0;
l2tp_tunnel->cwnd++;
} else {
/* Congestion Avoidance Phase
*
* The congestion window (CWND) increases by 1/CWND
* for every new ACK received. resulting in an
* linear increase. The variable cwcount is used
* track when to increment the congestion window.
*/
l2tp_tunnel->cwcount++;
if(l2tp_tunnel->cwcount >= l2tp_tunnel->cwnd) {
l2tp_tunnel->cwcount = 0;
l2tp_tunnel->cwnd++;
}
}
} else {
l2tp_tunnel->ssthresh = l2tp_tunnel->peer_receive_window;
}
break;
}
/* Handle received packet */
if(l2tp_tunnel->state != BBL_L2TP_TUNNEL_TERMINATED) {
switch (l2tp->type) {
case L2TP_MESSAGE_SCCCN:
@@ -956,9 +1014,15 @@ bbl_l2tp_handler_rx(bbl_ethernet_header_t *eth, bbl_l2tp_t *l2tp, bbl_interface_
case L2TP_MESSAGE_ICRQ:
return bbl_l2tp_icrq_rx(eth, l2tp, interface, l2tp_tunnel);
case L2TP_MESSAGE_ICCN:
return bbl_l2tp_iccn_rx(eth, l2tp, interface, l2tp_session);
if(l2tp_session->key.session_id) {
return bbl_l2tp_iccn_rx(eth, l2tp, interface, l2tp_session);
}
break;
case L2TP_MESSAGE_CDN:
return bbl_l2tp_cdn_rx(eth, l2tp, interface, l2tp_session);
if(l2tp_session->key.session_id) {
return bbl_l2tp_cdn_rx(eth, l2tp, interface, l2tp_session);
}
break;
default:
break;
}
@@ -966,19 +1030,34 @@ bbl_l2tp_handler_rx(bbl_ethernet_header_t *eth, bbl_l2tp_t *l2tp, bbl_interface_
} else {
if (L2TP_SEQ_LT(l2tp->ns, l2tp_tunnel->nr)) {
/* Duplicate packet received */
LOG(DEBUG, "L2TP Debug (%s) Duplicate %s received with Ns. %u (expected %u) from %s\n",
l2tp_tunnel->server->host_name,
l2tp_message_string(l2tp->type),
l2tp->ns, l2tp_tunnel->nr,
format_ipv4_address(&ipv4->src));
l2tp_tunnel->zlb = true;
l2tp_tunnel->stats.control_rx_dup++;
interface->stats.l2tp_control_rx_dup++;
if(!l2tp_tunnel->timer_tx_active) {
timer_add(&ctx->timer_root, &l2tp_tunnel->timer_tx, "L2TP TX", 0, 10 * MSEC, l2tp_tunnel, bbl_l2tp_tunnel_tx_job);
timer_add(&ctx->timer_root, &l2tp_tunnel->timer_tx, "L2TP TX", 0, L2TP_TX_WAIT_MS * MSEC, l2tp_tunnel, bbl_l2tp_tunnel_tx_job);
l2tp_tunnel->timer_tx_active = true;
}
} else {
/* Out-of-Order packet received */
LOG(DEBUG, "L2TP Debug (%s) Out-of-Order %s received with Ns. %u (expected %u) from %s\n",
l2tp_tunnel->server->host_name,
l2tp_message_string(l2tp->type),
l2tp->ns, l2tp_tunnel->nr,
format_ipv4_address(&ipv4->src));
l2tp_tunnel->stats.control_rx_ooo++;
interface->stats.l2tp_control_rx_ooo++;
}
}
} else {
/* Corresponding tunnel or session not found */
interface->stats.l2tp_control_rx_nf++;
}
}
src/bbl_l2tp.h
+12 -3
View File
@@ -15,7 +15,7 @@
#define L2TP_IPCP_IP_LOCAL 168495882
#define L2TP_IPCP_IP_REMOTE 168430090
#define L2TP_TX_WAIT_MS 10
#define L2TP_SEQ_LT(_a, _b)\
(((_a) < (_b) && (_b) - (_a) < 32768) || ((_a) > (_b) && (_a) - (_b) > 32768))
@@ -46,6 +46,14 @@ typedef enum {
BBL_L2TP_SESSION_MAX
} __attribute__ ((__packed__)) l2tp_session_state_t;
typedef enum {
BBL_L2TP_CONGESTION_DEFAULT = 0,
BBL_L2TP_CONGESTION_SLOW = 1,
BBL_L2TP_CONGESTION_AGGRESSIVE = 2,
BBL_L2TP_CONGESTION_MAX
} l2tp_congestion_mode_t;
/* L2TP Server Configuration (LNS) */
typedef struct bbl_l2tp_server_
{
@@ -56,6 +64,9 @@ typedef struct bbl_l2tp_server_
uint16_t session_limit;
uint16_t receive_window;
uint16_t max_retry;
l2tp_congestion_mode_t congestion_mode;
char *secret;
char *host_name;
@@ -120,8 +131,6 @@ typedef struct bbl_l2tp_tunnel_
uint16_t peer_tunnel_id;
uint16_t next_session_id;
bool initial_packet_send;
uint16_t ns;
uint16_t nr;
uint16_t peer_ns;