/* * File : dhcp_server.c * A simple DHCP server implementation * * This file is part of RT-Thread RTOS * COPYRIGHT (C) 2013-2015, Shanghai Real-Thread Technology Co., Ltd * http://www.rt-thread.com * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * Change Logs: * Date Author Notes * 2013-01-30 aozima the first version * 2013-08-08 aozima support different network segments. * 2015-01-30 bernard release to RT-Thread RTOS. */ #include #include #include #include #include #include #include #include #include /* DHCP server option */ /* allocated client ip range */ #ifndef DHCPD_CLIENT_IP_MIN #define DHCPD_CLIENT_IP_MIN 2 #endif #ifndef DHCPD_CLIENT_IP_MAX #define DHCPD_CLIENT_IP_MAX 254 #endif /* the DHCP server address */ #ifndef DHCPD_SERVER_IPADDR0 #define DHCPD_SERVER_IPADDR0 192UL #define DHCPD_SERVER_IPADDR1 168UL #define DHCPD_SERVER_IPADDR2 169UL #define DHCPD_SERVER_IPADDR3 1UL #endif //#define DHCP_DEBUG_PRINTF #ifdef DHCP_DEBUG_PRINTF #define DEBUG_PRINTF rt_kprintf("[DHCP] "); rt_kprintf #else #define DEBUG_PRINTF(...) #endif /* DHCP_DEBUG_PRINTF */ /* we need some routines in the DHCP of lwIP */ #undef LWIP_DHCP #define LWIP_DHCP 1 #include /* buffer size for receive DHCP packet */ #define BUFSZ 1024 static uint8_t next_client_ip = DHCPD_CLIENT_IP_MIN; static rt_err_t _low_level_dhcp_send(struct netif *netif, const void *buffer, rt_size_t size) { struct pbuf *p; struct eth_hdr *ethhdr; struct ip_hdr *iphdr; struct udp_hdr *udphdr; p = pbuf_alloc(PBUF_LINK, SIZEOF_ETH_HDR + sizeof(struct ip_hdr) + sizeof(struct udp_hdr) + size, PBUF_RAM); if (p == RT_NULL) return -RT_ENOMEM; ethhdr = (struct eth_hdr *)p->payload; iphdr = (struct ip_hdr *)((char *)ethhdr + SIZEOF_ETH_HDR); udphdr = (struct udp_hdr *)((char *)iphdr + sizeof(struct ip_hdr)); ETHADDR32_COPY(ðhdr->dest, (struct eth_addr *)ðbroadcast); ETHADDR16_COPY(ðhdr->src, netif->hwaddr); ethhdr->type = PP_HTONS(ETHTYPE_IP); iphdr->src.addr = 0x00000000; /* src: 0.0.0.0 */ iphdr->dest.addr = 0xFFFFFFFF; /* src: 255.255.255.255 */ IPH_VHL_SET(iphdr, 4, IP_HLEN / 4); IPH_TOS_SET(iphdr, 0x00); IPH_LEN_SET(iphdr, htons(IP_HLEN + sizeof(struct udp_hdr) + size)); IPH_ID_SET(iphdr, htons(2)); IPH_OFFSET_SET(iphdr, 0); IPH_TTL_SET(iphdr, 255); IPH_PROTO_SET(iphdr, IP_PROTO_UDP); IPH_CHKSUM_SET(iphdr, 0); IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN)); udphdr->src = htons(DHCP_SERVER_PORT); udphdr->dest = htons(DHCP_CLIENT_PORT); udphdr->len = htons(sizeof(struct udp_hdr) + size); udphdr->chksum = 0; memcpy((char *)udphdr + sizeof(struct udp_hdr), buffer, size); return netif->linkoutput(netif, p); } static void dhcpd_thread_entry(void *parameter) { struct netif *netif = RT_NULL; int sock; int bytes_read; char *recv_data; rt_uint32_t addr_len; struct sockaddr_in server_addr, client_addr; struct dhcp_msg *msg; int optval = 1; /* get ethernet interface. */ netif = (struct netif*) parameter; RT_ASSERT(netif != RT_NULL); /* our DHCP server information */ DEBUG_PRINTF("DHCP server IP: %d.%d.%d.%d client IP: %d.%d.%d.%d-%d\n", DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1, DHCPD_SERVER_IPADDR2, DHCPD_SERVER_IPADDR3, DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1, DHCPD_SERVER_IPADDR2, DHCPD_CLIENT_IP_MIN, DHCPD_CLIENT_IP_MAX); /* allocate buffer for receive */ recv_data = rt_malloc(BUFSZ); if (recv_data == RT_NULL) { /* No memory */ DEBUG_PRINTF("Out of memory\n"); return; } /* create a socket with UDP */ if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { DEBUG_PRINTF("create socket failed, errno = %d\n", errno); rt_free(recv_data); return; } /* set to receive broadcast packet */ setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(optval)); /* initialize server address */ server_addr.sin_family = AF_INET; server_addr.sin_port = htons(DHCP_SERVER_PORT); server_addr.sin_addr.s_addr = INADDR_ANY; rt_memset(&(server_addr.sin_zero), 0, sizeof(server_addr.sin_zero)); /* bind socket to the server address */ if (bind(sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1) { /* bind failed. */ DEBUG_PRINTF("bind server address failed, errno=%d\n", errno); rt_free(recv_data); return; } addr_len = sizeof(struct sockaddr); DEBUG_PRINTF("DHCP server listen on port %d...\n", DHCP_SERVER_PORT); while (1) { bytes_read = recvfrom(sock, recv_data, BUFSZ - 1, 0, (struct sockaddr *)&client_addr, &addr_len); if (bytes_read < DHCP_MSG_LEN) { DEBUG_PRINTF("packet too short, wait for next!\n"); continue; } msg = (struct dhcp_msg *)recv_data; /* check message type to make sure we can handle it */ if ((msg->op != DHCP_BOOTREQUEST) || (msg->cookie != PP_HTONL(DHCP_MAGIC_COOKIE))) { continue; } /* handler. */ { uint8_t *dhcp_opt; uint8_t option; uint8_t length; uint8_t message_type = 0; uint8_t finished = 0; uint32_t request_ip = 0; dhcp_opt = (uint8_t *)msg + DHCP_OPTIONS_OFS; while (finished == 0) { option = *dhcp_opt; length = *(dhcp_opt + 1); switch (option) { case DHCP_OPTION_REQUESTED_IP: request_ip = *(dhcp_opt + 2) << 24 | *(dhcp_opt + 3) << 16 | *(dhcp_opt + 4) << 8 | *(dhcp_opt + 5); break; case DHCP_OPTION_END: finished = 1; break; case DHCP_OPTION_MESSAGE_TYPE: message_type = *(dhcp_opt + 2); break; default: break; } /* switch(option) */ dhcp_opt += (2 + length); } /* reply. */ dhcp_opt = (uint8_t *)msg + DHCP_OPTIONS_OFS; /* check. */ if (request_ip) { uint32_t client_ip = DHCPD_SERVER_IPADDR0 << 24 | DHCPD_SERVER_IPADDR1 << 16 | DHCPD_SERVER_IPADDR2 << 8 | (next_client_ip); if (request_ip != client_ip) { *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE; *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE_LEN; *dhcp_opt++ = DHCP_NAK; *dhcp_opt++ = DHCP_OPTION_END; DEBUG_PRINTF("requested IP invalid, reply DHCP_NAK\n"); if (netif != RT_NULL) { int send_byte = (dhcp_opt - (uint8_t *)msg); _low_level_dhcp_send(netif, msg, send_byte); DEBUG_PRINTF("DHCP server send %d byte\n", send_byte); } next_client_ip++; if (next_client_ip > DHCPD_CLIENT_IP_MAX) next_client_ip = DHCPD_CLIENT_IP_MIN; continue; } } if (message_type == DHCP_DISCOVER) { DEBUG_PRINTF("request DHCP_DISCOVER\n"); DEBUG_PRINTF("reply DHCP_OFFER\n"); // DHCP_OPTION_MESSAGE_TYPE *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE; *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE_LEN; *dhcp_opt++ = DHCP_OFFER; // DHCP_OPTION_SERVER_ID *dhcp_opt++ = DHCP_OPTION_SERVER_ID; *dhcp_opt++ = 4; *dhcp_opt++ = DHCPD_SERVER_IPADDR0; *dhcp_opt++ = DHCPD_SERVER_IPADDR1; *dhcp_opt++ = DHCPD_SERVER_IPADDR2; *dhcp_opt++ = DHCPD_SERVER_IPADDR3; // DHCP_OPTION_LEASE_TIME *dhcp_opt++ = DHCP_OPTION_LEASE_TIME; *dhcp_opt++ = 4; *dhcp_opt++ = 0x00; *dhcp_opt++ = 0x01; *dhcp_opt++ = 0x51; *dhcp_opt++ = 0x80; } else if (message_type == DHCP_REQUEST) { DEBUG_PRINTF("request DHCP_REQUEST\n"); DEBUG_PRINTF("reply DHCP_ACK\n"); // DHCP_OPTION_MESSAGE_TYPE *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE; *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE_LEN; *dhcp_opt++ = DHCP_ACK; // DHCP_OPTION_SERVER_ID *dhcp_opt++ = DHCP_OPTION_SERVER_ID; *dhcp_opt++ = 4; *dhcp_opt++ = DHCPD_SERVER_IPADDR0; *dhcp_opt++ = DHCPD_SERVER_IPADDR1; *dhcp_opt++ = DHCPD_SERVER_IPADDR2; *dhcp_opt++ = DHCPD_SERVER_IPADDR3; // DHCP_OPTION_SUBNET_MASK *dhcp_opt++ = DHCP_OPTION_SUBNET_MASK; *dhcp_opt++ = 4; *dhcp_opt++ = 0xFF; *dhcp_opt++ = 0xFF; *dhcp_opt++ = 0xFF; *dhcp_opt++ = 0x00; #ifdef DHCPD_USING_ROUTER // DHCP_OPTION_ROUTER *dhcp_opt++ = DHCP_OPTION_ROUTER; *dhcp_opt++ = 4; *dhcp_opt++ = DHCPD_SERVER_IPADDR0; *dhcp_opt++ = DHCPD_SERVER_IPADDR1; *dhcp_opt++ = DHCPD_SERVER_IPADDR2; *dhcp_opt++ = 1; #endif // DHCP_OPTION_DNS_SERVER, use the default DNS server address in lwIP *dhcp_opt++ = DHCP_OPTION_DNS_SERVER; *dhcp_opt++ = 4; *dhcp_opt++ = 208; *dhcp_opt++ = 67; *dhcp_opt++ = 222; *dhcp_opt++ = 222; // DHCP_OPTION_LEASE_TIME *dhcp_opt++ = DHCP_OPTION_LEASE_TIME; *dhcp_opt++ = 4; *dhcp_opt++ = 0x00; *dhcp_opt++ = 0x01; *dhcp_opt++ = 0x51; *dhcp_opt++ = 0x80; } else { DEBUG_PRINTF("un handle message:%d\n", message_type); } // append DHCP_OPTION_END *dhcp_opt++ = DHCP_OPTION_END; /* send reply. */ if ((message_type == DHCP_DISCOVER) || (message_type == DHCP_REQUEST)) { msg->op = DHCP_BOOTREPLY; IP4_ADDR(&msg->yiaddr, DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1, DHCPD_SERVER_IPADDR2, next_client_ip); client_addr.sin_addr.s_addr = INADDR_BROADCAST; if (netif != RT_NULL) { int send_byte = (dhcp_opt - (uint8_t *)msg); _low_level_dhcp_send(netif, msg, send_byte); DEBUG_PRINTF("DHCP server send %d byte\n", send_byte); } } } /* handler. */ } } void dhcpd_start(char* netif_name) { rt_thread_t thread; struct netif *netif = RT_NULL; /* find ethernet interface. */ netif = netif_find(netif_name); if (netif == RT_NULL) { DEBUG_PRINTF("Not found network interface:%s\n", netif_name); } thread = rt_thread_create("dhcpd", dhcpd_thread_entry, netif, 1024, RT_THREAD_PRIORITY_MAX - 3, 2); if (thread != RT_NULL) { rt_thread_startup(thread); } }