From 025f6d09b9b5745ccb29621d93e0ed487d014ac2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wiesner=20Andr=C3=A1s?= <wabe@t-email.hu>
Date: Fri, 24 Feb 2023 11:29:32 +0100
Subject: [PATCH] DHCP processing semaphore added

---
 prefab/packet_parsers/dhcp.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/prefab/packet_parsers/dhcp.c b/prefab/packet_parsers/dhcp.c
index 530b76a..eade4d1 100644
--- a/prefab/packet_parsers/dhcp.c
+++ b/prefab/packet_parsers/dhcp.c
@@ -16,6 +16,7 @@ static struct {
     cbd desc;
     uint32_t tranId;
     EthInterface *intf;
+    ETHLIB_OS_SEM_TYPE procSem;
 } s;
 
 static const uint8_t DHCP_MAGIC_COOKIE[] = {99, 130, 83, 99};
@@ -248,6 +249,8 @@ void dhcp_request(ip4_addr reqAddr, ip4_addr dhcpServerAddr) {
 }
 
 static void dhcp_process(DhcpProps *props, DhcpOption *opts) {
+    ETHLIB_OS_SEM_WAIT(&s.procSem); // LOCK!
+
     switch (s.state) {
         case DHCP_INIT:
             dhcp_discover(); // send discover message
@@ -309,6 +312,8 @@ static void dhcp_process(DhcpProps *props, DhcpOption *opts) {
         default:
             break;
     }
+
+    ETHLIB_OS_SEM_POST(&s.procSem); // RELEASE!
 }
 
 static int dhcp_resp_cb(const Pckt *pckt, PcktSieveLayerTag tag) {
@@ -329,6 +334,8 @@ void dhcp_start() {
 }
 
 void dhcp_initiate(EthInterface *intf) {
+    ETHLIB_OS_SEM_CREATE(&s.procSem);
+    ETHLIB_OS_SEM_POST(&s.procSem);
     s.state = DHCP_INIT;
     s.buf = dynmem_alloc(DHCP_MIN_PACKET_SIZE);
     s.desc = udp_new_connblock(intf, IPv4_ANY_ADDR, DHCP_CLIENT_PORT, dhcp_resp_cb);