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BernardXiongBernardXiong
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[lwIP] Add DHCP server implementation
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‎components/net/lwip_dhcpd/SConscript‎

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from building import *
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cwd = GetCurrentDir()
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src = Glob('*.c')
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CPPPATH = [cwd]
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group = DefineGroup('LwIP', src, depend = ['RT_USING_LWIP', 'LWIP_USING_DHCPD'], CPPPATH = CPPPATH)
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Return('group')

‎components/net/lwip_dhcpd/dhcp_server.c‎

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/*
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* File : dhcp_server.c
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* A simple DHCP server implementation
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*
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* This file is part of RT-Thread RTOS
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* COPYRIGHT (C) 2013-2015, Shanghai Real-Thread Technology Co., Ltd
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* http://www.rt-thread.com
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Change Logs:
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* Date Author Notes
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* 2013-01-30 aozima the first version
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* 2013-08-08 aozima support different network segments.
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* 2015-01-30 bernard release to RT-Thread RTOS.
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*/
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#include <stdio.h>
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#include <stdint.h>
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#include <rtthread.h>
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#include <lwip/opt.h>
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#include <lwip/sockets.h>
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#include <lwip/inet_chksum.h>
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#include <netif/etharp.h>
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#include <netif/ethernetif.h>
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#include <lwip/ip.h>
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/* DHCP server option */
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/* allocated client ip range */
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#ifndef DHCPD_CLIENT_IP_MIN
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#define DHCPD_CLIENT_IP_MIN 2
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#endif
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#ifndef DHCPD_CLIENT_IP_MAX
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#define DHCPD_CLIENT_IP_MAX 254
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#endif
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/* the DHCP server address */
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#ifndef DHCPD_SERVER_IPADDR0
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#define DHCPD_SERVER_IPADDR0 192UL
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#define DHCPD_SERVER_IPADDR1 168UL
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#define DHCPD_SERVER_IPADDR2 169UL
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#define DHCPD_SERVER_IPADDR3 1UL
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#endif
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//#define DHCP_DEBUG_PRINTF
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#ifdef DHCP_DEBUG_PRINTF
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#define DEBUG_PRINTF rt_kprintf("[DHCP] "); rt_kprintf
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#else
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#define DEBUG_PRINTF(...)
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#endif /* DHCP_DEBUG_PRINTF */
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/* we need some routines in the DHCP of lwIP */
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#undef LWIP_DHCP
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#define LWIP_DHCP 1
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#include <lwip/dhcp.h>
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/* buffer size for receive DHCP packet */
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#define BUFSZ 1024
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static uint8_t next_client_ip = DHCPD_CLIENT_IP_MIN;
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static rt_err_t _low_level_dhcp_send(struct netif *netif,
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const void *buffer,
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rt_size_t size)
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{
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struct pbuf *p;
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struct eth_hdr *ethhdr;
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struct ip_hdr *iphdr;
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struct udp_hdr *udphdr;
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p = pbuf_alloc(PBUF_LINK,
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SIZEOF_ETH_HDR + sizeof(struct ip_hdr)
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+ sizeof(struct udp_hdr) + size,
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PBUF_RAM);
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if (p == RT_NULL) return -RT_ENOMEM;
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ethhdr = (struct eth_hdr *)p->payload;
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iphdr = (struct ip_hdr *)((char *)ethhdr + SIZEOF_ETH_HDR);
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udphdr = (struct udp_hdr *)((char *)iphdr + sizeof(struct ip_hdr));
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ETHADDR32_COPY(&ethhdr->dest, (struct eth_addr *)&ethbroadcast);
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ETHADDR16_COPY(&ethhdr->src, netif->hwaddr);
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ethhdr->type = PP_HTONS(ETHTYPE_IP);
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iphdr->src.addr = 0x00000000; /* src: 0.0.0.0 */
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iphdr->dest.addr = 0xFFFFFFFF; /* src: 255.255.255.255 */
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IPH_VHL_SET(iphdr, 4, IP_HLEN / 4);
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IPH_TOS_SET(iphdr, 0x00);
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IPH_LEN_SET(iphdr, htons(IP_HLEN + sizeof(struct udp_hdr) + size));
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IPH_ID_SET(iphdr, htons(2));
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IPH_OFFSET_SET(iphdr, 0);
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IPH_TTL_SET(iphdr, 255);
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IPH_PROTO_SET(iphdr, IP_PROTO_UDP);
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IPH_CHKSUM_SET(iphdr, 0);
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IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
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udphdr->src = htons(DHCP_SERVER_PORT);
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udphdr->dest = htons(DHCP_CLIENT_PORT);
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udphdr->len = htons(sizeof(struct udp_hdr) + size);
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udphdr->chksum = 0;
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memcpy((char *)udphdr + sizeof(struct udp_hdr),
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buffer, size);
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return netif->linkoutput(netif, p);
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}
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static void dhcpd_thread_entry(void *parameter)
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{
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struct netif *netif = RT_NULL;
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int sock;
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int bytes_read;
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char *recv_data;
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rt_uint32_t addr_len;
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struct sockaddr_in server_addr, client_addr;
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struct dhcp_msg *msg;
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int optval = 1;
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/* get ethernet interface. */
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netif = (struct netif*) parameter;
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RT_ASSERT(netif != RT_NULL);
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/* our DHCP server information */
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DEBUG_PRINTF("DHCP server IP: %d.%d.%d.%d client IP: %d.%d.%d.%d-%d\n",
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DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1,
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DHCPD_SERVER_IPADDR2, DHCPD_SERVER_IPADDR3,
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DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1,
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DHCPD_SERVER_IPADDR2, DHCPD_CLIENT_IP_MIN, DHCPD_CLIENT_IP_MAX);
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/* allocate buffer for receive */
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recv_data = rt_malloc(BUFSZ);
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if (recv_data == RT_NULL)
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{
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/* No memory */
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DEBUG_PRINTF("Out of memory\n");
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return;
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}
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/* create a socket with UDP */
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if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
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{
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DEBUG_PRINTF("create socket failed, errno = %d\n", errno);
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rt_free(recv_data);
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return;
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}
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/* set to receive broadcast packet */
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setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(optval));
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/* initialize server address */
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server_addr.sin_family = AF_INET;
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server_addr.sin_port = htons(DHCP_SERVER_PORT);
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server_addr.sin_addr.s_addr = INADDR_ANY;
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rt_memset(&(server_addr.sin_zero), 0, sizeof(server_addr.sin_zero));
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/* bind socket to the server address */
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if (bind(sock, (struct sockaddr *)&server_addr,
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sizeof(struct sockaddr)) == -1)
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{
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/* bind failed. */
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DEBUG_PRINTF("bind server address failed, errno=%d\n", errno);
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rt_free(recv_data);
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return;
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}
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addr_len = sizeof(struct sockaddr);
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DEBUG_PRINTF("DHCP server listen on port %d...\n", DHCP_SERVER_PORT);
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while (1)
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{
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bytes_read = recvfrom(sock, recv_data, BUFSZ - 1, 0,
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(struct sockaddr *)&client_addr, &addr_len);
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if (bytes_read < DHCP_MSG_LEN)
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{
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DEBUG_PRINTF("packet too short, wait for next!\n");
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continue;
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}
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msg = (struct dhcp_msg *)recv_data;
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/* check message type to make sure we can handle it */
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if ((msg->op != DHCP_BOOTREQUEST) || (msg->cookie != PP_HTONL(DHCP_MAGIC_COOKIE)))
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{
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continue;
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}
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/* handler. */
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{
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uint8_t *dhcp_opt;
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uint8_t option;
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uint8_t length;
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uint8_t message_type = 0;
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uint8_t finished = 0;
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uint32_t request_ip = 0;
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dhcp_opt = (uint8_t *)msg + DHCP_OPTIONS_OFS;
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while (finished == 0)
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{
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option = *dhcp_opt;
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length = *(dhcp_opt + 1);
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switch (option)
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{
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case DHCP_OPTION_REQUESTED_IP:
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request_ip = *(dhcp_opt + 2) << 24 | *(dhcp_opt + 3) << 16
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| *(dhcp_opt + 4) << 8 | *(dhcp_opt + 5);
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break;
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case DHCP_OPTION_END:
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finished = 1;
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break;
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case DHCP_OPTION_MESSAGE_TYPE:
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message_type = *(dhcp_opt + 2);
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break;
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default:
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break;
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} /* switch(option) */
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dhcp_opt += (2 + length);
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}
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/* reply. */
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dhcp_opt = (uint8_t *)msg + DHCP_OPTIONS_OFS;
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/* check. */
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if (request_ip)
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{
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uint32_t client_ip = DHCPD_SERVER_IPADDR0 << 24 | DHCPD_SERVER_IPADDR1 << 16
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| DHCPD_SERVER_IPADDR2 << 8 | (next_client_ip);
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if (request_ip != client_ip)
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{
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*dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE;
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*dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE_LEN;
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*dhcp_opt++ = DHCP_NAK;
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*dhcp_opt++ = DHCP_OPTION_END;
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DEBUG_PRINTF("requested IP invalid, reply DHCP_NAK\n");
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if (netif != RT_NULL)
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{
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int send_byte = (dhcp_opt - (uint8_t *)msg);
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_low_level_dhcp_send(netif, msg, send_byte);
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DEBUG_PRINTF("DHCP server send %d byte\n", send_byte);
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}
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next_client_ip++;
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if (next_client_ip > DHCPD_CLIENT_IP_MAX)
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next_client_ip = DHCPD_CLIENT_IP_MIN;
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continue;
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}
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}
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if (message_type == DHCP_DISCOVER)
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{
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DEBUG_PRINTF("request DHCP_DISCOVER\n");
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DEBUG_PRINTF("reply DHCP_OFFER\n");
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// DHCP_OPTION_MESSAGE_TYPE
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*dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE;
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*dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE_LEN;
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*dhcp_opt++ = DHCP_OFFER;
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// DHCP_OPTION_SERVER_ID
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*dhcp_opt++ = DHCP_OPTION_SERVER_ID;
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*dhcp_opt++ = 4;
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*dhcp_opt++ = DHCPD_SERVER_IPADDR0;
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*dhcp_opt++ = DHCPD_SERVER_IPADDR1;
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*dhcp_opt++ = DHCPD_SERVER_IPADDR2;
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*dhcp_opt++ = DHCPD_SERVER_IPADDR3;
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// DHCP_OPTION_LEASE_TIME
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*dhcp_opt++ = DHCP_OPTION_LEASE_TIME;
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*dhcp_opt++ = 4;
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*dhcp_opt++ = 0x00;
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*dhcp_opt++ = 0x01;
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*dhcp_opt++ = 0x51;
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*dhcp_opt++ = 0x80;
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}
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else if (message_type == DHCP_REQUEST)
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{
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DEBUG_PRINTF("request DHCP_REQUEST\n");
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DEBUG_PRINTF("reply DHCP_ACK\n");
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// DHCP_OPTION_MESSAGE_TYPE
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*dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE;
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*dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE_LEN;
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*dhcp_opt++ = DHCP_ACK;
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// DHCP_OPTION_SERVER_ID
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*dhcp_opt++ = DHCP_OPTION_SERVER_ID;
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*dhcp_opt++ = 4;
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*dhcp_opt++ = DHCPD_SERVER_IPADDR0;
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*dhcp_opt++ = DHCPD_SERVER_IPADDR1;
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*dhcp_opt++ = DHCPD_SERVER_IPADDR2;
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*dhcp_opt++ = DHCPD_SERVER_IPADDR3;
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// DHCP_OPTION_SUBNET_MASK
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*dhcp_opt++ = DHCP_OPTION_SUBNET_MASK;
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*dhcp_opt++ = 4;
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*dhcp_opt++ = 0xFF;
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*dhcp_opt++ = 0xFF;
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*dhcp_opt++ = 0xFF;
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*dhcp_opt++ = 0x00;
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// DHCP_OPTION_LEASE_TIME
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*dhcp_opt++ = DHCP_OPTION_LEASE_TIME;
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*dhcp_opt++ = 4;
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*dhcp_opt++ = 0x00;
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*dhcp_opt++ = 0x01;
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*dhcp_opt++ = 0x51;
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*dhcp_opt++ = 0x80;
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}
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else
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{
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DEBUG_PRINTF("un handle message:%d\n", message_type);
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}
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// append DHCP_OPTION_END
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*dhcp_opt++ = DHCP_OPTION_END;
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/* send reply. */
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if ((message_type == DHCP_DISCOVER) || (message_type == DHCP_REQUEST))
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{
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msg->op = DHCP_BOOTREPLY;
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IP4_ADDR(&msg->yiaddr,
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DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1,
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DHCPD_SERVER_IPADDR2, next_client_ip);
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client_addr.sin_addr.s_addr = INADDR_BROADCAST;
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if (netif != RT_NULL)
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{
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int send_byte = (dhcp_opt - (uint8_t *)msg);
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_low_level_dhcp_send(netif, msg, send_byte);
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DEBUG_PRINTF("DHCP server send %d byte\n", send_byte);
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}
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}
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} /* handler. */
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}
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}
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void dhcpd_start(char* netif_name)
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{
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rt_thread_t thread;
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struct netif *netif = RT_NULL;
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/* find ethernet interface. */
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netif = netif_find(netif_name);
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if (netif == RT_NULL)
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{
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DEBUG_PRINTF("Not found network interface:%s\n", netif_name);
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}
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thread = rt_thread_create("dhcpd",
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dhcpd_thread_entry, netif,
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1024,
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RT_THREAD_PRIORITY_MAX - 3,
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2);
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if (thread != RT_NULL)
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{
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rt_thread_startup(thread);
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}
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}
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