From f927b9fbab0478eb8af0246e988e5a390af81d69 Mon Sep 17 00:00:00 2001
From: 1e1 <2.71828183e0+git@gmail.com>
Date: Wed, 28 Jul 2021 10:56:25 +0200
Subject: [PATCH] fix: the dhcp client behaviour is not standard compliant for
 DHCP clients (RFC2131) (IDFGH-5139)

---
 glue-lwip/arduino/lwipopts.h |  8 ++++++++
 glue-lwip/lwip-git.c         | 29 +++++++++++++++++++++++++++++
 makefiles/Makefile.defs      |  1 +
 3 files changed, 38 insertions(+)

diff --git a/glue-lwip/arduino/lwipopts.h b/glue-lwip/arduino/lwipopts.h
index d79dc8b7..fc682be0 100644
--- a/glue-lwip/arduino/lwipopts.h
+++ b/glue-lwip/arduino/lwipopts.h
@@ -3579,6 +3579,14 @@ extern void lwip_hook_dhcp_parse_option(struct netif *netif, struct dhcp *dhcp,
                                         int msg_type, int option, int option_len, struct pbuf *pbuf,
                                         int option_value_offset);
 
+#if LWIP_FEATURES
+#define LWIP_HOOK_DHCP_APPEND_OPTIONS(netif, dhcp, state, msg, msg_type, option_len_ptr) \
+   lwip_hook_dhcp_amend_options(netif, dhcp, state, msg, msg_type, option_len_ptr)
+
+extern void lwip_hook_dhcp_amend_options(struct netif *netif, struct dhcp *dhcp, int state, struct dhcp_msg *msg,
+                                         int msg_type, int *option_len_ptr);
+#endif
+
 /*
    --------------------------------------------------
    ------------------ SNTP options ------------------
diff --git a/glue-lwip/lwip-git.c b/glue-lwip/lwip-git.c
index 3845d976..e2351b72 100644
--- a/glue-lwip/lwip-git.c
+++ b/glue-lwip/lwip-git.c
@@ -32,6 +32,7 @@ author: d. gauchard
 #include "glue.h"
 #include "uprint.h"
 #include "lwip-helper.h"
+#include "lwip/prot/dhcp.h"
 
 #include "lwipopts.h"
 #include "lwip/err.h"
@@ -196,6 +197,7 @@ err_glue_t esp2glue_dhcp_start (int netif_idx)
 	// calls netif_sta_status_callback() - if applicable (STA)
 	netif_set_up(&netif_git[netif_idx]);
 
+#if LWIP_NETIF_HOSTNAME
 	// Update to latest esp hostname before starting dhcp client,
 	// 	because this name is provided to the dhcp server.
 	// Until proven wrong, dhcp client is the only code
@@ -205,6 +207,7 @@ err_glue_t esp2glue_dhcp_start (int netif_idx)
 	// XXX to check: is wifi_station_get_hostname()
 	// 	returning a const pointer once _set_hostname is called?
 	netif_git[netif_idx].hostname = wifi_station_get_hostname();
+#endif
 
 	err_t err = dhcp_start(&netif_git[netif_idx]);
 #if LWIP_IPV6 && LWIP_IPV6_DHCP6_STATELESS
@@ -352,7 +355,9 @@ static void netif_init_common (struct netif* netif)
 	netif->ip6_autoconfig_enabled = 1;
 #endif
 	
+#if LWIP_NETIF_HOSTNAME
 	netif->hostname = wifi_station_get_hostname();
+#endif
 	netif->chksum_flags = NETIF_CHECKSUM_ENABLE_ALL;
 	// netif->mtu given by glue
 }
@@ -409,7 +414,9 @@ void esp2glue_netif_update (int netif_idx, uint32_t ip, uint32_t mask, uint32_t
 		netif->flags &= ~NETIF_FLAG_UP;
 
 	netif->mtu = mtu;
+#if LWIP_NETIF_HOSTNAME
 	netif->hostname = wifi_station_get_hostname();
+#endif
 	ip4_addr_t aip = { ip }, amask = { mask }, agw = { gw };
 	netif_set_addr(&netif_git[netif_idx], &aip, &amask, &agw);
 	esp2glue_netif_set_up1down0(netif_idx, 1);
@@ -569,4 +576,26 @@ void lwip_hook_dhcp_parse_option(struct netif *netif, struct dhcp *dhcp, int sta
     uprint(DBG "unhandled dhcp option in lwip_hook_dhcp_parse_option()\n");
 }
 
+void lwip_hook_dhcp_amend_options(struct netif *netif, struct dhcp *dhcp, int state, struct dhcp_msg *msg,
+                                         int msg_type, int *option_len_ptr);
+
+void lwip_hook_dhcp_amend_options(struct netif *netif, struct dhcp *dhcp, int state, struct dhcp_msg *msg,
+                                         int msg_type, int *option_len_ptr)
+{
+	// amend default Client-Identifier
+	// {intf.id} {intf.mac} => {01}:{AA:BB:CC:11:22:33}
+ 	{
+		size_t i;
+		
+		msg->options[(*option_len_ptr)++] = DHCP_OPTION_CLIENT_ID;
+		msg->options[(*option_len_ptr)++] = 1 + netif->hwaddr_len;
+		msg->options[(*option_len_ptr)++] = 0x01;
+
+		for (i = 0; i < netif->hwaddr_len; ++i) {
+			msg->options[(*option_len_ptr)++] = netif->hwaddr[i];
+		}
+	}
+}
+
+
 #endif // ARDUINO
diff --git a/makefiles/Makefile.defs b/makefiles/Makefile.defs
index bbce1de1..32552bbd 100644
--- a/makefiles/Makefile.defs
+++ b/makefiles/Makefile.defs
@@ -26,3 +26,4 @@ OD			= $(TOOLS)objdump
 BUILD			?= build
 BUILD_FLAGS += -Wall -Wextra -c -Os -g -free -fipa-pta -Wpointer-arith -Wl,-EL -fno-inline-functions -nostdlib -mlongcalls -mtext-section-literals -falign-functions=4 -MMD -ffunction-sections -fdata-sections
 BUILD_DEFINES = -D__ets__ -DICACHE_FLASH -U__STRICT_ANSI__ -DLWIP_OPEN_SRC -DLWIP_BUILD -DUSE_OPTIMIZE_PRINTF -DTARGET=$(target) -D$(DEFINE_TARGET)=1 -DTCP_MSS=$(TCP_MSS) -DLWIP_FEATURES=$(LWIP_FEATURES) -DLWIP_IPV6=$(LWIP_IPV6)
+BUILD_DEFINES += -DLWIP_NETIF_HOSTNAME=$(LWIP_FEATURES) -DESP_DHCP=$(LWIP_FEATURES)