1 /*
2 * File : dhcp_server.c
3 * A simple DHCP server implementation
4 *
5 * COPYRIGHT (C) 2011-2018, Shanghai Real-Thread Technology Co., Ltd
6 * http://www.rt-thread.com
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without modification,
10 * are permitted provided that the following conditions are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright notice,
15 * this list of conditions and the following disclaimer in the documentation
16 * and/or other materials provided with the distribution.
17 * 3. The name of the author may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
21 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
23 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
25 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
28 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
29 * OF SUCH DAMAGE.
30 *
31 * Change Logs:
32 * Date Author Notes
33 * 2013-01-30 aozima the first version
34 * 2013-08-08 aozima support different network segments.
35 * 2015-01-30 bernard release to RT-Thread RTOS.
36 * 2017-12-27 aozima add [mac-ip] table support.
37 */
38
39 #include <stdio.h>
40 #include <stdint.h>
41 #include <rtthread.h>
42
43 #include <lwip/opt.h>
44 #include <lwip/sockets.h>
45 #include <lwip/inet_chksum.h>
46 #include <netif/etharp.h>
47 #include <netif/ethernetif.h>
48 #include <lwip/ip.h>
49 #include <lwip/init.h>
50
51 #if (LWIP_VERSION) >= 0x02000000U
52 #include <lwip/prot/dhcp.h>
53 #endif
54
55 /* DHCP server option */
56
57 /* allocated client ip range */
58 #ifndef DHCPD_CLIENT_IP_MIN
59 #define DHCPD_CLIENT_IP_MIN 2
60 #endif
61 #ifndef DHCPD_CLIENT_IP_MAX
62 #define DHCPD_CLIENT_IP_MAX 254
63 #endif
64
65 /* the DHCP server address */
66 #ifndef DHCPD_SERVER_IP
67 #define DHCPD_SERVER_IP "192.168.169.1"
68 #endif
69
70 //#define DHCP_DEBUG_PRINTF
71
72 #ifdef DHCP_DEBUG_PRINTF
73 #define DEBUG_PRINTF rt_kprintf("[DHCP] "); rt_kprintf
74 #else
75 #define DEBUG_PRINTF(...)
76 #endif /* DHCP_DEBUG_PRINTF */
77
78 /* we need some routines in the DHCP of lwIP */
79 #undef LWIP_DHCP
80 #define LWIP_DHCP 1
81 #include <lwip/dhcp.h>
82
83 /* buffer size for receive DHCP packet */
84 #define BUFSZ 1024
85
86 #ifndef MAC_ADDR_LEN
87 #define MAC_ADDR_LEN 6
88 #endif
89
90 #ifndef MAC_TABLE_LEN
91 #define MAC_TABLE_LEN 4
92 #endif
93
94 struct mac_addr_t
95 {
96 uint8_t add[MAC_ADDR_LEN];
97 };
98
99 struct mac_ip_item_t
100 {
101 struct mac_addr_t mac_addr;
102 uint8_t ip_addr_3;
103 };
104
_low_level_dhcp_send(struct netif * netif,const void * buffer,rt_size_t size)105 static rt_err_t _low_level_dhcp_send(struct netif *netif,
106 const void *buffer,
107 rt_size_t size)
108 {
109 struct pbuf *p;
110 struct eth_hdr *ethhdr;
111 struct ip_hdr *iphdr;
112 struct udp_hdr *udphdr;
113
114 p = pbuf_alloc(PBUF_LINK,
115 SIZEOF_ETH_HDR + sizeof(struct ip_hdr)
116 + sizeof(struct udp_hdr) + size,
117 PBUF_RAM);
118 if (p == RT_NULL) return -RT_ENOMEM;
119
120 ethhdr = (struct eth_hdr *)p->payload;
121 iphdr = (struct ip_hdr *)((char *)ethhdr + SIZEOF_ETH_HDR);
122 udphdr = (struct udp_hdr *)((char *)iphdr + sizeof(struct ip_hdr));
123
124 ETHADDR32_COPY(ðhdr->dest, (struct eth_addr *)ðbroadcast);
125 ETHADDR16_COPY(ðhdr->src, netif->hwaddr);
126 ethhdr->type = PP_HTONS(ETHTYPE_IP);
127
128 iphdr->src.addr = 0x00000000; /* src: 0.0.0.0 */
129 iphdr->dest.addr = 0xFFFFFFFF; /* src: 255.255.255.255 */
130
131 IPH_VHL_SET(iphdr, 4, IP_HLEN / 4);
132 IPH_TOS_SET(iphdr, 0x00);
133 IPH_LEN_SET(iphdr, htons(IP_HLEN + sizeof(struct udp_hdr) + size));
134 IPH_ID_SET(iphdr, htons(2));
135 IPH_OFFSET_SET(iphdr, 0);
136 IPH_TTL_SET(iphdr, 255);
137 IPH_PROTO_SET(iphdr, IP_PROTO_UDP);
138 IPH_CHKSUM_SET(iphdr, 0);
139 IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
140
141 udphdr->src = htons(DHCP_SERVER_PORT);
142 udphdr->dest = htons(DHCP_CLIENT_PORT);
143 udphdr->len = htons(sizeof(struct udp_hdr) + size);
144 udphdr->chksum = 0;
145
146 memcpy((char *)udphdr + sizeof(struct udp_hdr),
147 buffer, size);
148
149 netif->linkoutput(netif, p);
150 pbuf_free(p);
151
152 return RT_EOK;
153 }
154
get_ip(struct mac_addr_t * p_mac_addr)155 static uint8_t get_ip(struct mac_addr_t *p_mac_addr)
156 {
157 static uint8_t next_client_ip = DHCPD_CLIENT_IP_MIN;
158 static struct mac_ip_item_t mac_table[MAC_TABLE_LEN];
159 static int offset = 0;
160
161 struct mac_addr_t bad_mac;
162 int i;
163 uint8_t ip_addr_3;
164
165 rt_memset(&bad_mac, 0, sizeof(bad_mac));
166 if (!rt_memcmp(&bad_mac, p_mac_addr, sizeof(bad_mac)))
167 {
168 DEBUG_PRINTF("mac address all zero");
169 ip_addr_3 = DHCPD_CLIENT_IP_MAX;
170 goto _return;
171 }
172
173 rt_memset(&bad_mac, 0xFF, sizeof(bad_mac));
174 if (!rt_memcmp(&bad_mac, p_mac_addr, sizeof(bad_mac)))
175 {
176 DEBUG_PRINTF("mac address all one");
177 ip_addr_3 = DHCPD_CLIENT_IP_MAX;
178 goto _return;
179 }
180
181 for (i = 0; i < MAC_TABLE_LEN; i++)
182 {
183 if (!rt_memcmp(&mac_table[i].mac_addr, p_mac_addr, sizeof(bad_mac)))
184 {
185 //use old ip
186 ip_addr_3 = mac_table[i].ip_addr_3;
187 DEBUG_PRINTF("return old ip: %d\n", (int)ip_addr_3);
188 goto _return;
189 }
190 }
191
192 /* add new ip */
193 mac_table[offset].mac_addr = *p_mac_addr;
194 mac_table[offset].ip_addr_3 = next_client_ip;
195 ip_addr_3 = mac_table[offset].ip_addr_3 ;
196
197 offset++;
198 if (offset >= MAC_TABLE_LEN)
199 offset = 0;
200
201 next_client_ip++;
202 if (next_client_ip > DHCPD_CLIENT_IP_MAX)
203 next_client_ip = DHCPD_CLIENT_IP_MIN;
204
205 DEBUG_PRINTF("create new ip: %d\n", (int)ip_addr_3);
206 DEBUG_PRINTF("next_client_ip %d\n", next_client_ip);
207
208 _return:
209 return ip_addr_3;
210 }
211
dhcpd_thread_entry(void * parameter)212 static void dhcpd_thread_entry(void *parameter)
213 {
214 struct netif *netif = RT_NULL;
215 int sock;
216 int bytes_read;
217 char *recv_data;
218 rt_uint32_t addr_len;
219 struct sockaddr_in server_addr, client_addr;
220 struct dhcp_msg *msg;
221 int optval = 1;
222 struct mac_addr_t mac_addr;
223 uint8_t DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1, DHCPD_SERVER_IPADDR2, DHCPD_SERVER_IPADDR3;
224
225 /* get ethernet interface. */
226 netif = (struct netif *) parameter;
227 RT_ASSERT(netif != RT_NULL);
228
229 /* our DHCP server information */
230 {
231 #if (LWIP_VERSION) >= 0x02000000U
232 ip4_addr_t addr;
233 ip4addr_aton(DHCPD_SERVER_IP, &addr);
234 #else
235 struct ip_addr addr;
236 ipaddr_aton(DHCPD_SERVER_IP, &addr);
237 #endif /* LWIP_VERSION */
238
239 DHCPD_SERVER_IPADDR0 = (ntohl(addr.addr) >> 24) & 0xFF;
240 DHCPD_SERVER_IPADDR1 = (ntohl(addr.addr) >> 16) & 0xFF;
241 DHCPD_SERVER_IPADDR2 = (ntohl(addr.addr) >> 8) & 0xFF;
242 DHCPD_SERVER_IPADDR3 = (ntohl(addr.addr) >> 0) & 0xFF;
243 }
244 DEBUG_PRINTF("DHCP server IP: %d.%d.%d.%d client IP: %d.%d.%d.%d-%d\n",
245 DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1,
246 DHCPD_SERVER_IPADDR2, DHCPD_SERVER_IPADDR3,
247 DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1,
248 DHCPD_SERVER_IPADDR2, DHCPD_CLIENT_IP_MIN, DHCPD_CLIENT_IP_MAX);
249
250 /* allocate buffer for receive */
251 recv_data = rt_malloc(BUFSZ);
252 if (recv_data == RT_NULL)
253 {
254 /* No memory */
255 DEBUG_PRINTF("Out of memory\n");
256 return;
257 }
258
259 /* create a socket with UDP */
260 if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
261 {
262 DEBUG_PRINTF("create socket failed, errno = %d\n", errno);
263 rt_free(recv_data);
264 return;
265 }
266
267 /* set to receive broadcast packet */
268 setsockopt(sock, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(optval));
269
270 /* initialize server address */
271 server_addr.sin_family = AF_INET;
272 server_addr.sin_port = htons(DHCP_SERVER_PORT);
273 server_addr.sin_addr.s_addr = INADDR_ANY;
274 rt_memset(&(server_addr.sin_zero), 0, sizeof(server_addr.sin_zero));
275
276 /* bind socket to the server address */
277 if (bind(sock, (struct sockaddr *)&server_addr,
278 sizeof(struct sockaddr)) == -1)
279 {
280 /* bind failed. */
281 DEBUG_PRINTF("bind server address failed, errno=%d\n", errno);
282 rt_free(recv_data);
283 return;
284 }
285
286 addr_len = sizeof(struct sockaddr);
287 DEBUG_PRINTF("DHCP server listen on port %d...\n", DHCP_SERVER_PORT);
288
289 while (1)
290 {
291 bytes_read = recvfrom(sock, recv_data, BUFSZ - 1, 0,
292 (struct sockaddr *)&client_addr, &addr_len);
293 if (bytes_read < DHCP_MSG_LEN)
294 {
295 DEBUG_PRINTF("packet too short, wait for next!\n");
296 continue;
297 }
298
299 msg = (struct dhcp_msg *)recv_data;
300 /* check message type to make sure we can handle it */
301 if ((msg->op != DHCP_BOOTREQUEST) || (msg->cookie != PP_HTONL(DHCP_MAGIC_COOKIE)))
302 {
303 continue;
304 }
305
306 memcpy(mac_addr.add, msg->chaddr, MAC_ADDR_LEN);
307
308 /* handler. */
309 {
310 uint8_t *dhcp_opt;
311 uint8_t option;
312 uint8_t length;
313
314 uint8_t message_type = 0;
315 uint8_t finished = 0;
316 uint32_t request_ip = 0;
317
318 uint8_t client_ip_3;
319
320 client_ip_3 = get_ip(&mac_addr);
321
322 dhcp_opt = (uint8_t *)msg + DHCP_OPTIONS_OFS;
323 while (finished == 0)
324 {
325 option = *dhcp_opt;
326 length = *(dhcp_opt + 1);
327
328 switch (option)
329 {
330 case DHCP_OPTION_REQUESTED_IP:
331 request_ip = *(dhcp_opt + 2) << 24 | *(dhcp_opt + 3) << 16
332 | *(dhcp_opt + 4) << 8 | *(dhcp_opt + 5);
333 break;
334
335 case DHCP_OPTION_END:
336 finished = 1;
337 break;
338
339 case DHCP_OPTION_MESSAGE_TYPE:
340 message_type = *(dhcp_opt + 2);
341 break;
342
343 default:
344 break;
345 } /* switch(option) */
346
347 dhcp_opt += (2 + length);
348 }
349
350 /* reply. */
351 dhcp_opt = (uint8_t *)msg + DHCP_OPTIONS_OFS;
352
353 /* check. */
354 if (request_ip)
355 {
356 uint32_t client_ip = DHCPD_SERVER_IPADDR0 << 24 | DHCPD_SERVER_IPADDR1 << 16
357 | DHCPD_SERVER_IPADDR2 << 8 | client_ip_3;
358
359 DEBUG_PRINTF("message_type: %d, request_ip: %08X, client_ip: %08X.\n", message_type, request_ip, client_ip);
360
361 if (request_ip != client_ip)
362 {
363 *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE;
364 *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE_LEN;
365 *dhcp_opt++ = DHCP_NAK;
366 *dhcp_opt++ = DHCP_OPTION_END;
367
368 DEBUG_PRINTF("requested IP invalid, reply DHCP_NAK\n");
369
370 if (netif != RT_NULL)
371 {
372 int send_byte = (dhcp_opt - (uint8_t *)msg);
373 _low_level_dhcp_send(netif, msg, send_byte);
374 DEBUG_PRINTF("DHCP server send %d byte\n", send_byte);
375 }
376
377 continue;
378 }
379 }
380
381 if (message_type == DHCP_DISCOVER)
382 {
383 DEBUG_PRINTF("request DHCP_DISCOVER\n");
384 DEBUG_PRINTF("reply DHCP_OFFER\n");
385
386 // DHCP_OPTION_MESSAGE_TYPE
387 *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE;
388 *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE_LEN;
389 *dhcp_opt++ = DHCP_OFFER;
390
391 // DHCP_OPTION_SERVER_ID
392 *dhcp_opt++ = DHCP_OPTION_SERVER_ID;
393 *dhcp_opt++ = 4;
394 *dhcp_opt++ = DHCPD_SERVER_IPADDR0;
395 *dhcp_opt++ = DHCPD_SERVER_IPADDR1;
396 *dhcp_opt++ = DHCPD_SERVER_IPADDR2;
397 *dhcp_opt++ = DHCPD_SERVER_IPADDR3;
398
399 // DHCP_OPTION_LEASE_TIME
400 *dhcp_opt++ = DHCP_OPTION_LEASE_TIME;
401 *dhcp_opt++ = 4;
402 *dhcp_opt++ = 0x00;
403 *dhcp_opt++ = 0x01;
404 *dhcp_opt++ = 0x51;
405 *dhcp_opt++ = 0x80;
406 }
407 else if (message_type == DHCP_REQUEST)
408 {
409 DEBUG_PRINTF("request DHCP_REQUEST\n");
410 DEBUG_PRINTF("reply DHCP_ACK\n");
411
412 // DHCP_OPTION_MESSAGE_TYPE
413 *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE;
414 *dhcp_opt++ = DHCP_OPTION_MESSAGE_TYPE_LEN;
415 *dhcp_opt++ = DHCP_ACK;
416
417 // DHCP_OPTION_SERVER_ID
418 *dhcp_opt++ = DHCP_OPTION_SERVER_ID;
419 *dhcp_opt++ = 4;
420 *dhcp_opt++ = DHCPD_SERVER_IPADDR0;
421 *dhcp_opt++ = DHCPD_SERVER_IPADDR1;
422 *dhcp_opt++ = DHCPD_SERVER_IPADDR2;
423 *dhcp_opt++ = DHCPD_SERVER_IPADDR3;
424
425 // DHCP_OPTION_SUBNET_MASK
426 *dhcp_opt++ = DHCP_OPTION_SUBNET_MASK;
427 *dhcp_opt++ = 4;
428 *dhcp_opt++ = 0xFF;
429 *dhcp_opt++ = 0xFF;
430 *dhcp_opt++ = 0xFF;
431 *dhcp_opt++ = 0x00;
432
433 #ifdef DHCPD_USING_ROUTER
434 // DHCP_OPTION_ROUTER
435 *dhcp_opt++ = DHCP_OPTION_ROUTER;
436 *dhcp_opt++ = 4;
437 *dhcp_opt++ = DHCPD_SERVER_IPADDR0;
438 *dhcp_opt++ = DHCPD_SERVER_IPADDR1;
439 *dhcp_opt++ = DHCPD_SERVER_IPADDR2;
440 *dhcp_opt++ = 1;
441 #endif
442
443 // DHCP_OPTION_DNS_SERVER, use the default DNS server address in lwIP
444 *dhcp_opt++ = DHCP_OPTION_DNS_SERVER;
445 *dhcp_opt++ = 4;
446
447 #ifndef DHCP_DNS_SERVER_IP
448 *dhcp_opt++ = DHCPD_SERVER_IPADDR0;
449 *dhcp_opt++ = DHCPD_SERVER_IPADDR1;
450 *dhcp_opt++ = DHCPD_SERVER_IPADDR2;
451 *dhcp_opt++ = 1;
452 #else
453 {
454 #if (LWIP_VERSION) >= 0x02000000U
455 ip4_addr_t dns_addr;
456 #else
457 struct ip_addr dns_addr;
458 #endif /* LWIP_VERSION */
459 ip4addr_aton(DHCP_DNS_SERVER_IP, &dns_addr);
460
461 *dhcp_opt++ = (ntohl(dns_addr.addr) >> 24) & 0xFF;
462 *dhcp_opt++ = (ntohl(dns_addr.addr) >> 16) & 0xFF;
463 *dhcp_opt++ = (ntohl(dns_addr.addr) >> 8) & 0xFF;
464 *dhcp_opt++ = (ntohl(dns_addr.addr) >> 0) & 0xFF;
465 }
466 #endif
467
468 // DHCP_OPTION_LEASE_TIME
469 *dhcp_opt++ = DHCP_OPTION_LEASE_TIME;
470 *dhcp_opt++ = 4;
471 *dhcp_opt++ = 0x00;
472 *dhcp_opt++ = 0x01;
473 *dhcp_opt++ = 0x51;
474 *dhcp_opt++ = 0x80;
475 }
476 else
477 {
478 DEBUG_PRINTF("un handle message:%d\n", message_type);
479 }
480
481 // append DHCP_OPTION_END
482 *dhcp_opt++ = DHCP_OPTION_END;
483
484 /* send reply. */
485 if ((message_type == DHCP_DISCOVER) || (message_type == DHCP_REQUEST))
486 {
487 msg->op = DHCP_BOOTREPLY;
488 IP4_ADDR(&msg->yiaddr,
489 DHCPD_SERVER_IPADDR0, DHCPD_SERVER_IPADDR1,
490 DHCPD_SERVER_IPADDR2, client_ip_3);
491
492 client_addr.sin_addr.s_addr = INADDR_BROADCAST;
493
494 if (netif != RT_NULL)
495 {
496 int send_byte = (dhcp_opt - (uint8_t *)msg);
497 _low_level_dhcp_send(netif, msg, send_byte);
498 DEBUG_PRINTF("DHCP server send %d byte\n", send_byte);
499 }
500 }
501 } /* handler. */
502 }
503 }
504
dhcpd_start(const char * netif_name)505 void dhcpd_start(const char *netif_name)
506 {
507 rt_thread_t thread;
508 struct netif *netif = netif_list;
509
510 if (strlen(netif_name) > sizeof(netif->name))
511 {
512 rt_kprintf("network interface name too long!\r\n");
513 return;
514 }
515 while (netif != RT_NULL)
516 {
517 if (strncmp(netif_name, netif->name, sizeof(netif->name)) == 0)
518 break;
519
520 netif = netif->next;
521 if (netif == RT_NULL)
522 {
523 rt_kprintf("network interface: %s not found!\r\n", netif_name);
524 return;
525 }
526 }
527
528 if (1)
529 {
530 extern void set_if(const char *netif_name, const char *ip_addr, const char *gw_addr, const char *nm_addr);
531
532 dhcp_stop(netif);
533
534 set_if(netif_name, DHCPD_SERVER_IP, "0.0.0.0", "255.255.255.0");
535
536 netif_set_up(netif);
537 }
538
539 thread = rt_thread_create("dhcpd",
540 dhcpd_thread_entry, netif,
541 1024,
542 RT_THREAD_PRIORITY_MAX - 3,
543 2);
544 if (thread != RT_NULL)
545 {
546 rt_thread_startup(thread);
547 }
548 }
549
550