From fa953dbf4d6aea227600a1a7616c5d612c23eb68 Mon Sep 17 00:00:00 2001
From: Christian Giese <christian@rtbrick.com>
Date: Tue, 25 May 2021 10:22:02 +0200
Subject: [PATCH] Fixed #28 IPoE ARP

+ fix IPoE ARP interval
+ add IPoE ARP timeout/interval config
---
 docs/config.md   |  2 ++
 src/bbl.h        |  4 ++++
 src/bbl_config.c | 10 ++++++++++
 src/bbl_rx.c     |  9 +++++++++
 src/bbl_tx.c     |  6 ++++--
 src/bbl_tx.h     |  3 +++
 6 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/docs/config.md b/docs/config.md
index fc0eb4d8..fd4013ed 100644
--- a/docs/config.md
+++ b/docs/config.md
@@ -369,6 +369,8 @@ This section describes all attributes of the `ipoe` (IP over Ethernet) hierarchy
 Attribute | Description | Default 
 --------- | ----------- | -------
 `ipv4` | Enable/disable IPv4 | true (enabled)
+`arp-timeout` | Initial ARP resolve timeout/retry interval in seconds | 1 
+`arp-interval` | Periodic ARP interval in seconds (0 means disabled) | 300
 `ipv6` | Enable/disable IPv6 | true (enabled)
 
 ## PPPoE
diff --git a/src/bbl.h b/src/bbl.h
index 4ebe27f3..73033115 100644
--- a/src/bbl.h
+++ b/src/bbl.h
@@ -580,6 +580,10 @@ typedef struct bbl_ctx_
         /* IPv4 (IPoE) */
         bool ipv4_enable;
 
+        /* ARP (IPoE) */
+        uint16_t arp_timeout;
+        uint16_t arp_interval;
+
         /* IPv6 (IPoE) */
         bool ipv6_enable;
 
diff --git a/src/bbl_config.c b/src/bbl_config.c
index 8db8db7d..e9e030e4 100644
--- a/src/bbl_config.c
+++ b/src/bbl_config.c
@@ -525,6 +525,14 @@ json_parse_config (json_t *root, bbl_ctx_s *ctx) {
         if (json_is_boolean(value)) {
             ctx->config.ipv4_enable = json_boolean_value(value);
         }
+        value = json_object_get(section, "arp-timeout");
+        if (json_is_number(value)) {
+            ctx->config.arp_timeout = json_number_value(value);
+        }
+        value = json_object_get(section, "arp-interval");
+        if (json_is_number(value)) {
+            ctx->config.arp_interval = json_number_value(value);
+        }
         value = json_object_get(section, "ipv6");
         if (json_is_boolean(value)) {
             ctx->config.ipv6_enable = json_boolean_value(value);
@@ -1140,6 +1148,8 @@ bbl_config_init_defaults (bbl_ctx_s *ctx) {
     ctx->config.authentication_timeout = 5;
     ctx->config.authentication_retry = 30;
     ctx->config.ipv4_enable = true;
+    ctx->config.arp_timeout = 1;
+    ctx->config.arp_interval = 300;
     ctx->config.ipv6_enable = true;
     ctx->config.ipcp_enable = true;
     ctx->config.ipcp_request_ip = true;
diff --git a/src/bbl_rx.c b/src/bbl_rx.c
index 985df98c..36089fa9 100644
--- a/src/bbl_rx.c
+++ b/src/bbl_rx.c
@@ -11,6 +11,7 @@
 #include "bbl_session.h"
 #include "bbl_stream.h"
 #include "bbl_dhcp.h"
+#include "bbl_tx.h"
 #include <openssl/md5.h>
 #include <openssl/rand.h>
 
@@ -1874,6 +1875,8 @@ bbl_rx_discovery(bbl_ethernet_header_t *eth, bbl_interface_s *interface, bbl_ses
 void
 bbl_rx_arp(bbl_ethernet_header_t *eth, bbl_interface_s *interface, bbl_session_s *session) {
     bbl_arp_t *arp = (bbl_arp_t*)eth->next;
+    bbl_ctx_s *ctx;
+
     if(arp->sender_ip == session->peer_ip_address) {
         if(!session->arp_resolved) {
             memcpy(session->server_mac, arp->sender, ETH_ADDR_LEN);
@@ -1885,8 +1888,14 @@ bbl_rx_arp(bbl_ethernet_header_t *eth, bbl_interface_s *interface, bbl_session_s
             }
         } else {
             if(!session->arp_resolved) {
+                ctx = session->interface->ctx;
                 bbl_rx_established_ipoe(eth, interface, session);
                 session->arp_resolved = true;
+                if(ctx->config.arp_interval) {
+                    timer_add(&ctx->timer_root, &session->timer_arp, "ARP timeout", ctx->config.arp_interval, 0, session, &bbl_arp_timeout);
+                } else {
+                    timer_del(session->timer_arp);
+                }
             }
         }
     }
diff --git a/src/bbl_tx.c b/src/bbl_tx.c
index a58c332f..85fcfe62 100644
--- a/src/bbl_tx.c
+++ b/src/bbl_tx.c
@@ -1370,9 +1370,11 @@ bbl_encode_packet_arp_request (bbl_session_s *session)
     arp.target_ip = session->peer_ip_address;
 
     if(session->arp_resolved) {
-        timer_add(&ctx->timer_root, &session->timer_arp, "ARP timeout", 300, 0, session, &bbl_arp_timeout);
+        if(ctx->config.arp_interval) {
+            timer_add(&ctx->timer_root, &session->timer_arp, "ARP timeout", ctx->config.arp_interval, 0, session, &bbl_arp_timeout);
+        }
     } else {
-        timer_add(&ctx->timer_root, &session->timer_arp, "ARP timeout", 1, 0, session, &bbl_arp_timeout);
+        timer_add(&ctx->timer_root, &session->timer_arp, "ARP timeout", ctx->config.arp_timeout, 0, session, &bbl_arp_timeout);
     }
     interface->stats.arp_tx++;
     if(!ctx->stats.first_session_tx.tv_sec) {
diff --git a/src/bbl_tx.h b/src/bbl_tx.h
index f691a3c7..0c03e328 100644
--- a/src/bbl_tx.h
+++ b/src/bbl_tx.h
@@ -9,6 +9,9 @@
 #ifndef __BBL_TX_H__
 #define __BBL_TX_H__
 
+void
+bbl_arp_timeout (timer_s *timer);
+
 protocol_error_t
 bbl_tx (bbl_ctx_s *ctx, bbl_interface_s *interface, uint8_t *buf, uint16_t *len);