nodemcu-firmware/app/include/lwip/app/dhcpserver.h

#ifndef __DHCPS_H__
#define __DHCPS_H__

#include "lwipopts.h"

#define USE_DNS

typedef struct dhcps_state{
        sint16_t state;
} dhcps_state;

// <20><><EFBFBD><EFBFBD>dhcpclient<6E>Զ<EFBFBD><D4B6><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>DHCP msg<73>ṹ<EFBFBD><E1B9B9>
typedef struct dhcps_msg {
        uint8_t op, htype, hlen, hops;
        uint8_t xid[4];
        uint16_t secs, flags;
        uint8_t ciaddr[4];
        uint8_t yiaddr[4];
        uint8_t siaddr[4];
        uint8_t giaddr[4];
        uint8_t chaddr[16];
        uint8_t sname[64];
        uint8_t file[128];
        uint8_t options[312];
}dhcps_msg;

#ifndef LWIP_OPEN_SRC
struct dhcps_lease {
	bool enable;
	struct ip_addr start_ip;
	struct ip_addr end_ip;
};

enum dhcps_offer_option{
	OFFER_START = 0x00,
	OFFER_ROUTER = 0x01,
	OFFER_END
};
#endif

typedef enum {
    DHCPS_TYPE_DYNAMIC,
    DHCPS_TYPE_STATIC
} dhcps_type_t;

typedef enum {
    DHCPS_STATE_ONLINE,
    DHCPS_STATE_OFFLINE
} dhcps_state_t;

struct dhcps_pool{
	struct ip_addr ip;
	uint8 mac[6];
	uint32 lease_timer;
    dhcps_type_t type;
    dhcps_state_t state;

};

typedef struct _list_node{
	void *pnode;
	struct _list_node *pnext;
}list_node;

extern uint32 dhcps_lease_time;
#define DHCPS_LEASE_TIMER  dhcps_lease_time  //0x05A0
#define DHCPS_MAX_LEASE 0x64
#define BOOTP_BROADCAST 0x8000

#define DHCP_REQUEST        1
#define DHCP_REPLY          2
#define DHCP_HTYPE_ETHERNET 1
#define DHCP_HLEN_ETHERNET  6
#define DHCP_MSG_LEN      236

#define DHCPS_SERVER_PORT  67
#define DHCPS_CLIENT_PORT  68

#define DHCPDISCOVER  1
#define DHCPOFFER     2
#define DHCPREQUEST   3
#define DHCPDECLINE   4
#define DHCPACK       5
#define DHCPNAK       6
#define DHCPRELEASE   7

#define DHCP_OPTION_SUBNET_MASK   1
#define DHCP_OPTION_ROUTER        3
#define DHCP_OPTION_DNS_SERVER    6
#define DHCP_OPTION_REQ_IPADDR   50
#define DHCP_OPTION_LEASE_TIME   51
#define DHCP_OPTION_MSG_TYPE     53
#define DHCP_OPTION_SERVER_ID    54
#define DHCP_OPTION_INTERFACE_MTU 26
#define DHCP_OPTION_PERFORM_ROUTER_DISCOVERY 31
#define DHCP_OPTION_BROADCAST_ADDRESS 28
#define DHCP_OPTION_REQ_LIST     55
#define DHCP_OPTION_END         255

//#define USE_CLASS_B_NET 1
#define DHCPS_DEBUG          0
#define MAX_STATION_NUM      8

#define DHCPS_STATE_OFFER 1
#define DHCPS_STATE_DECLINE 2
#define DHCPS_STATE_ACK 3
#define DHCPS_STATE_NAK 4
#define DHCPS_STATE_IDLE 5
#define DHCPS_STATE_RELEASE 6

#define   dhcps_router_enabled(offer)	((offer & OFFER_ROUTER) != 0)

void dhcps_start(struct ip_info *info);
void dhcps_stop(void);

#endif