1 /**
2 * @file
3 * NetBIOS name service responder
4 */
5
6 /**
7 * @defgroup netbiosns NETBIOS responder
8 * @ingroup apps
9 *
10 * This is an example implementation of a NetBIOS name server.
11 * It responds to name queries for a configurable name.
12 * Name resolving is not supported.
13 *
14 * Note that the device doesn't broadcast it's own name so can't
15 * detect duplicate names!
16 */
17
18 /*
19 * Redistribution and use in source and binary forms, with or without modification,
20 * are permitted provided that the following conditions are met:
21 *
22 * 1. Redistributions of source code must retain the above copyright notice,
23 * this list of conditions and the following disclaimer.
24 * 2. Redistributions in binary form must reproduce the above copyright notice,
25 * this list of conditions and the following disclaimer in the documentation
26 * and/or other materials provided with the distribution.
27 * 3. The name of the author may not be used to endorse or promote products
28 * derived from this software without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
31 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
32 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
33 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
34 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
35 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
37 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
38 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
39 * OF SUCH DAMAGE.
40 *
41 * This file is part of the lwIP TCP/IP stack.
42 *
43 * Modifications by Ray Abram to respond to NetBIOS name requests when Incoming name = *
44 * - based on code from "https://github.com/esp8266/Arduino/commit/1f7989b31d26d7df9776a08f36d685eae7ac8f99"
45 * - with permission to relicense to BSD from original author:
46 * http://www.xpablo.cz/?p=751#more-751
47 */
48
49 #include "lwip/apps/netbiosns.h"
50
51 #if LWIP_IPV4 && LWIP_UDP /* don't build if not configured for use in lwipopts.h */
52
53 #include "lwip/def.h"
54 #include "lwip/udp.h"
55 #include "lwip/ip.h"
56 #include "lwip/netif.h"
57 #include "lwip/prot/iana.h"
58
59 #include <string.h>
60
61 /** size of a NetBIOS name */
62 #define NETBIOS_NAME_LEN 16
63
64 /** The Time-To-Live for NetBIOS name responds (in seconds)
65 * Default is 300000 seconds (3 days, 11 hours, 20 minutes) */
66 #define NETBIOS_NAME_TTL 300000u
67
68 /** NetBIOS header flags */
69 #define NETB_HFLAG_RESPONSE 0x8000U
70 #define NETB_HFLAG_OPCODE 0x7800U
71 #define NETB_HFLAG_OPCODE_NAME_QUERY 0x0000U
72 #define NETB_HFLAG_AUTHORATIVE 0x0400U
73 #define NETB_HFLAG_TRUNCATED 0x0200U
74 #define NETB_HFLAG_RECURS_DESIRED 0x0100U
75 #define NETB_HFLAG_RECURS_AVAILABLE 0x0080U
76 #define NETB_HFLAG_BROADCAST 0x0010U
77 #define NETB_HFLAG_REPLYCODE 0x0008U
78 #define NETB_HFLAG_REPLYCODE_NOERROR 0x0000U
79
80 /* NetBIOS question types */
81 #define NETB_QTYPE_NB 0x0020U
82 #define NETB_QTYPE_NBSTAT 0x0021U
83
84 /** NetBIOS name flags */
85 #define NETB_NFLAG_UNIQUE 0x8000U
86 #define NETB_NFLAG_NODETYPE 0x6000U
87 #define NETB_NFLAG_NODETYPE_HNODE 0x6000U
88 #define NETB_NFLAG_NODETYPE_MNODE 0x4000U
89 #define NETB_NFLAG_NODETYPE_PNODE 0x2000U
90 #define NETB_NFLAG_NODETYPE_BNODE 0x0000U
91
92 #define NETB_NFLAG_NAME_IN_CONFLICT 0x0800U /* 1=Yes, 0=No */
93 #define NETB_NFLAG_NAME_IS_ACTIVE 0x0400U /* 1=Yes, 0=No */
94 #define NETB_NFLAG_NAME_IS_PERMANENT 0x0200U /* 1=Yes (Name is Permanent Node Name), 0=No */
95
96 /** NetBIOS message header */
97 #ifdef PACK_STRUCT_USE_INCLUDES
98 # include "arch/bpstruct.h"
99 #endif
100 PACK_STRUCT_BEGIN
101 struct netbios_hdr {
102 PACK_STRUCT_FIELD(u16_t trans_id);
103 PACK_STRUCT_FIELD(u16_t flags);
104 PACK_STRUCT_FIELD(u16_t questions);
105 PACK_STRUCT_FIELD(u16_t answerRRs);
106 PACK_STRUCT_FIELD(u16_t authorityRRs);
107 PACK_STRUCT_FIELD(u16_t additionalRRs);
108 } PACK_STRUCT_STRUCT;
109 PACK_STRUCT_END
110 #ifdef PACK_STRUCT_USE_INCLUDES
111 # include "arch/epstruct.h"
112 #endif
113
114 /** NetBIOS message name part */
115 #ifdef PACK_STRUCT_USE_INCLUDES
116 # include "arch/bpstruct.h"
117 #endif
118 PACK_STRUCT_BEGIN
119 struct netbios_name_hdr {
120 PACK_STRUCT_FLD_8(u8_t nametype);
121 PACK_STRUCT_FLD_8(u8_t encname[(NETBIOS_NAME_LEN * 2) + 1]);
122 PACK_STRUCT_FIELD(u16_t type);
123 PACK_STRUCT_FIELD(u16_t cls);
124 PACK_STRUCT_FIELD(u32_t ttl);
125 PACK_STRUCT_FIELD(u16_t datalen);
126 PACK_STRUCT_FIELD(u16_t flags);
127 PACK_STRUCT_FLD_S(ip4_addr_p_t addr);
128 } PACK_STRUCT_STRUCT;
129 PACK_STRUCT_END
130 #ifdef PACK_STRUCT_USE_INCLUDES
131 # include "arch/epstruct.h"
132 #endif
133
134 /** NetBIOS message */
135 #ifdef PACK_STRUCT_USE_INCLUDES
136 # include "arch/bpstruct.h"
137 #endif
138 PACK_STRUCT_BEGIN
139 struct netbios_resp {
140 struct netbios_hdr resp_hdr;
141 struct netbios_name_hdr resp_name;
142 } PACK_STRUCT_STRUCT;
143 PACK_STRUCT_END
144 #ifdef PACK_STRUCT_USE_INCLUDES
145 # include "arch/epstruct.h"
146 #endif
147
148 /** The NBNS Structure Responds to a Name Query */
149 #ifdef PACK_STRUCT_USE_INCLUDES
150 # include "arch/bpstruct.h"
151 #endif
152 PACK_STRUCT_BEGIN
153 struct netbios_answer {
154 struct netbios_hdr answer_hdr;
155 /** the length of the next string */
156 PACK_STRUCT_FIELD(u8_t name_size);
157 /** WARNING!!! this item may be of a different length (we use this struct for transmission) */
158 PACK_STRUCT_FLD_8(u8_t query_name[(NETBIOS_NAME_LEN * 2) + 1]);
159 PACK_STRUCT_FIELD(u16_t packet_type);
160 PACK_STRUCT_FIELD(u16_t cls);
161 PACK_STRUCT_FIELD(u32_t ttl);
162 PACK_STRUCT_FIELD(u16_t data_length);
163 #define OFFSETOF_STRUCT_NETBIOS_ANSWER_NUMBER_OF_NAMES 56
164 /** number of names */
165 PACK_STRUCT_FLD_8(u8_t number_of_names);
166 /** node name */
167 PACK_STRUCT_FLD_8(u8_t answer_name[NETBIOS_NAME_LEN]);
168 /** node flags */
169 PACK_STRUCT_FIELD(u16_t answer_name_flags);
170 /** Unit ID */
171 PACK_STRUCT_FLD_8(u8_t unit_id[6]);
172 /** Jumpers */
173 PACK_STRUCT_FLD_8(u8_t jumpers);
174 /** Test result */
175 PACK_STRUCT_FLD_8(u8_t test_result);
176 /** Version number */
177 PACK_STRUCT_FIELD(u16_t version_number);
178 /** Period of statistics */
179 PACK_STRUCT_FIELD(u16_t period_of_statistics);
180 /** Statistics */
181 PACK_STRUCT_FIELD(u16_t number_of_crcs);
182 /** Statistics */
183 PACK_STRUCT_FIELD(u16_t number_of_alignment_errors);
184 /** Statistics */
185 PACK_STRUCT_FIELD(u16_t number_of_collisions);
186 /** Statistics */
187 PACK_STRUCT_FIELD(u16_t number_of_send_aborts);
188 /** Statistics */
189 PACK_STRUCT_FIELD(u32_t number_of_good_sends);
190 /** Statistics */
191 PACK_STRUCT_FIELD(u32_t number_of_good_receives);
192 /** Statistics */
193 PACK_STRUCT_FIELD(u16_t number_of_retransmits);
194 /** Statistics */
195 PACK_STRUCT_FIELD(u16_t number_of_no_resource_condition);
196 /** Statistics */
197 PACK_STRUCT_FIELD(u16_t number_of_free_command_blocks);
198 /** Statistics */
199 PACK_STRUCT_FIELD(u16_t total_number_of_command_blocks);
200 /** Statistics */
201 PACK_STRUCT_FIELD(u16_t max_total_number_of_command_blocks);
202 /** Statistics */
203 PACK_STRUCT_FIELD(u16_t number_of_pending_sessions);
204 /** Statistics */
205 PACK_STRUCT_FIELD(u16_t max_number_of_pending_sessions);
206 /** Statistics */
207 PACK_STRUCT_FIELD(u16_t max_total_sessions_possible);
208 /** Statistics */
209 PACK_STRUCT_FIELD(u16_t session_data_packet_size);
210 } PACK_STRUCT_STRUCT;
211 PACK_STRUCT_END
212 #ifdef PACK_STRUCT_USE_INCLUDES
213 # include "arch/epstruct.h"
214 #endif
215
216 #ifdef NETBIOS_LWIP_NAME
217 #define NETBIOS_LOCAL_NAME NETBIOS_LWIP_NAME
218 #else
219 static char netbiosns_local_name[NETBIOS_NAME_LEN];
220 #define NETBIOS_LOCAL_NAME netbiosns_local_name
221 #endif
222
223 static struct udp_pcb *netbiosns_pcb;
224
225 /** Decode a NetBIOS name (from packet to string) */
226 static int
netbiosns_name_decode(char * name_enc,char * name_dec,int name_dec_len)227 netbiosns_name_decode(char *name_enc, char *name_dec, int name_dec_len)
228 {
229 char *pname;
230 char cname;
231 char cnbname;
232 int idx = 0;
233
234 LWIP_UNUSED_ARG(name_dec_len);
235
236 /* Start decoding netbios name. */
237 pname = name_enc;
238 for (;;) {
239 /* Every two characters of the first level-encoded name
240 * turn into one character in the decoded name. */
241 cname = *pname;
242 if (cname == '\0') {
243 break; /* no more characters */
244 }
245 if (cname == '.') {
246 break; /* scope ID follows */
247 }
248 if (!lwip_isupper(cname)) {
249 /* Not legal. */
250 return -1;
251 }
252 cname -= 'A';
253 cnbname = cname << 4;
254 pname++;
255
256 cname = *pname;
257 if (!lwip_isupper(cname)) {
258 /* Not legal. */
259 return -1;
260 }
261 cname -= 'A';
262 cnbname |= cname;
263 pname++;
264
265 /* Do we have room to store the character? */
266 if (idx < NETBIOS_NAME_LEN) {
267 /* Yes - store the character. */
268 name_dec[idx++] = (cnbname != ' ' ? cnbname : '\0');
269 }
270 }
271
272 return 0;
273 }
274
275 #if 0 /* function currently unused */
276 /** Encode a NetBIOS name (from string to packet) - currently unused because
277 we don't ask for names. */
278 static int
279 netbiosns_name_encode(char *name_enc, char *name_dec, int name_dec_len)
280 {
281 char *pname;
282 char cname;
283 unsigned char ucname;
284 int idx = 0;
285
286 /* Start encoding netbios name. */
287 pname = name_enc;
288
289 for (;;) {
290 /* Every two characters of the first level-encoded name
291 * turn into one character in the decoded name. */
292 cname = *pname;
293 if (cname == '\0') {
294 break; /* no more characters */
295 }
296 if (cname == '.') {
297 break; /* scope ID follows */
298 }
299 if ((cname < 'A' || cname > 'Z') && (cname < '0' || cname > '9')) {
300 /* Not legal. */
301 return -1;
302 }
303
304 /* Do we have room to store the character? */
305 if (idx >= name_dec_len) {
306 return -1;
307 }
308
309 /* Yes - store the character. */
310 ucname = cname;
311 name_dec[idx++] = ('A' + ((ucname >> 4) & 0x0F));
312 name_dec[idx++] = ('A' + ( ucname & 0x0F));
313 pname++;
314 }
315
316 /* Fill with "space" coding */
317 for (; idx < name_dec_len - 1;) {
318 name_dec[idx++] = 'C';
319 name_dec[idx++] = 'A';
320 }
321
322 /* Terminate string */
323 name_dec[idx] = '\0';
324
325 return 0;
326 }
327 #endif /* 0 */
328
329 /** NetBIOS Name service recv callback */
330 static void
netbiosns_recv(void * arg,struct udp_pcb * upcb,struct pbuf * p,const ip_addr_t * addr,u16_t port)331 netbiosns_recv(void *arg, struct udp_pcb *upcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
332 {
333 LWIP_UNUSED_ARG(arg);
334
335 /* if packet is valid */
336 if (p != NULL) {
337 char netbios_name[NETBIOS_NAME_LEN + 1];
338 struct netbios_hdr *netbios_hdr = (struct netbios_hdr *)p->payload;
339 struct netbios_name_hdr *netbios_name_hdr = (struct netbios_name_hdr *)(netbios_hdr + 1);
340
341 /* is the packet long enough (we need the header in one piece) */
342 if (p->len < (sizeof(struct netbios_hdr) + sizeof(struct netbios_name_hdr))) {
343 /* packet too short */
344 pbuf_free(p);
345 return;
346 }
347 /* we only answer if we got a default interface */
348 if (netif_default != NULL) {
349 /* @todo: do we need to check answerRRs/authorityRRs/additionalRRs? */
350 /* if the packet is a NetBIOS name query question */
351 if (((netbios_hdr->flags & PP_NTOHS(NETB_HFLAG_OPCODE)) == PP_NTOHS(NETB_HFLAG_OPCODE_NAME_QUERY)) &&
352 ((netbios_hdr->flags & PP_NTOHS(NETB_HFLAG_RESPONSE)) == 0) &&
353 (netbios_hdr->questions == PP_NTOHS(1))) {
354 /* decode the NetBIOS name */
355 netbiosns_name_decode((char *)(netbios_name_hdr->encname), netbios_name, sizeof(netbios_name));
356 /* check the request type */
357 if (netbios_name_hdr->type == PP_HTONS(NETB_QTYPE_NB)) {
358 /* if the packet is for us */
359 if (lwip_strnicmp(netbios_name, NETBIOS_LOCAL_NAME, sizeof(NETBIOS_LOCAL_NAME)) == 0) {
360 struct pbuf *q;
361 struct netbios_resp *resp;
362
363 q = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct netbios_resp), PBUF_RAM);
364 if (q != NULL) {
365 resp = (struct netbios_resp *)q->payload;
366
367 /* prepare NetBIOS header response */
368 resp->resp_hdr.trans_id = netbios_hdr->trans_id;
369 resp->resp_hdr.flags = PP_HTONS(NETB_HFLAG_RESPONSE |
370 NETB_HFLAG_OPCODE_NAME_QUERY |
371 NETB_HFLAG_AUTHORATIVE |
372 NETB_HFLAG_RECURS_DESIRED);
373 resp->resp_hdr.questions = 0;
374 resp->resp_hdr.answerRRs = PP_HTONS(1);
375 resp->resp_hdr.authorityRRs = 0;
376 resp->resp_hdr.additionalRRs = 0;
377
378 /* prepare NetBIOS header datas */
379 MEMCPY( resp->resp_name.encname, netbios_name_hdr->encname, sizeof(netbios_name_hdr->encname));
380 resp->resp_name.nametype = netbios_name_hdr->nametype;
381 resp->resp_name.type = netbios_name_hdr->type;
382 resp->resp_name.cls = netbios_name_hdr->cls;
383 resp->resp_name.ttl = PP_HTONL(NETBIOS_NAME_TTL);
384 resp->resp_name.datalen = PP_HTONS(sizeof(resp->resp_name.flags) + sizeof(resp->resp_name.addr));
385 resp->resp_name.flags = PP_HTONS(NETB_NFLAG_NODETYPE_BNODE);
386 ip4_addr_copy(resp->resp_name.addr, *netif_ip4_addr(netif_default));
387
388 /* send the NetBIOS response */
389 udp_sendto(upcb, q, addr, port);
390
391 /* free the "reference" pbuf */
392 pbuf_free(q);
393 }
394 }
395 #if LWIP_NETBIOS_RESPOND_NAME_QUERY
396 } else if (netbios_name_hdr->type == PP_HTONS(NETB_QTYPE_NBSTAT)) {
397 /* if the packet is for us or general query */
398 if (!lwip_strnicmp(netbios_name, NETBIOS_LOCAL_NAME, sizeof(NETBIOS_LOCAL_NAME)) ||
399 !lwip_strnicmp(netbios_name, "*", sizeof(NETBIOS_LOCAL_NAME))) {
400 /* general query - ask for our IP address */
401 struct pbuf *q;
402 struct netbios_answer *resp;
403
404 q = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct netbios_answer), PBUF_RAM);
405 if (q != NULL) {
406 /* buffer to which a response is compiled */
407 resp = (struct netbios_answer *) q->payload;
408
409 /* Init response to zero, especially the statistics fields */
410 memset(resp, 0, sizeof(*resp));
411
412 /* copy the query to the response ID */
413 resp->answer_hdr.trans_id = netbios_hdr->trans_id;
414 /* acknowledgment of termination */
415 resp->answer_hdr.flags = PP_HTONS(NETB_HFLAG_RESPONSE | NETB_HFLAG_OPCODE_NAME_QUERY | NETB_HFLAG_AUTHORATIVE);
416 /* resp->answer_hdr.questions = PP_HTONS(0); done by memset() */
417 /* serial number of the answer */
418 resp->answer_hdr.answerRRs = PP_HTONS(1);
419 /* resp->answer_hdr.authorityRRs = PP_HTONS(0); done by memset() */
420 /* resp->answer_hdr.additionalRRs = PP_HTONS(0); done by memset() */
421 /* we will copy the length of the station name */
422 resp->name_size = netbios_name_hdr->nametype;
423 /* we will copy the queried name */
424 MEMCPY(resp->query_name, netbios_name_hdr->encname, (NETBIOS_NAME_LEN * 2) + 1);
425 /* NBSTAT */
426 resp->packet_type = PP_HTONS(0x21);
427 /* Internet name */
428 resp->cls = PP_HTONS(1);
429 /* resp->ttl = PP_HTONL(0); done by memset() */
430 resp->data_length = PP_HTONS(sizeof(struct netbios_answer) - offsetof(struct netbios_answer, number_of_names));
431 resp->number_of_names = 1;
432
433 /* make windows see us as workstation, not as a server */
434 memset(resp->answer_name, 0x20, NETBIOS_NAME_LEN - 1);
435 /* strlen is checked to be < NETBIOS_NAME_LEN during initialization */
436 MEMCPY(resp->answer_name, NETBIOS_LOCAL_NAME, strlen(NETBIOS_LOCAL_NAME));
437
438 /* b-node, unique, active */
439 resp->answer_name_flags = PP_HTONS(NETB_NFLAG_NAME_IS_ACTIVE);
440
441 /* Set responder netif MAC address */
442 SMEMCPY(resp->unit_id, ip_current_input_netif()->hwaddr, sizeof(resp->unit_id));
443
444 udp_sendto(upcb, q, addr, port);
445 pbuf_free(q);
446 }
447 }
448 #endif /* LWIP_NETBIOS_RESPOND_NAME_QUERY */
449 }
450 }
451 }
452 /* free the pbuf */
453 pbuf_free(p);
454 }
455 }
456
457 /**
458 * @ingroup netbiosns
459 * Init netbios responder
460 */
461 void
netbiosns_init(void)462 netbiosns_init(void)
463 {
464 /* LWIP_ASSERT_CORE_LOCKED(); is checked by udp_new() */
465 #ifdef NETBIOS_LWIP_NAME
466 LWIP_ASSERT("NetBIOS name is too long!", strlen(NETBIOS_LWIP_NAME) < NETBIOS_NAME_LEN);
467 #endif
468
469 netbiosns_pcb = udp_new_ip_type(IPADDR_TYPE_ANY);
470 if (netbiosns_pcb != NULL) {
471 /* we have to be allowed to send broadcast packets! */
472 ip_set_option(netbiosns_pcb, SOF_BROADCAST);
473 udp_bind(netbiosns_pcb, IP_ANY_TYPE, LWIP_IANA_PORT_NETBIOS);
474 udp_recv(netbiosns_pcb, netbiosns_recv, netbiosns_pcb);
475 }
476 }
477
478 #ifndef NETBIOS_LWIP_NAME
479 /**
480 * @ingroup netbiosns
481 * Set netbios name. ATTENTION: the hostname must be less than 15 characters!
482 * the NetBIOS name spec says the name MUST be upper case, so incoming name is forced into uppercase :-)
483 */
484 void
netbiosns_set_name(const char * hostname)485 netbiosns_set_name(const char *hostname)
486 {
487 size_t i;
488 size_t copy_len = strlen(hostname);
489 LWIP_ASSERT_CORE_LOCKED();
490 LWIP_ASSERT("NetBIOS name is too long!", copy_len < NETBIOS_NAME_LEN);
491 if (copy_len >= NETBIOS_NAME_LEN) {
492 copy_len = NETBIOS_NAME_LEN - 1;
493 }
494
495 /* make name into upper case */
496 for (i = 0; i < copy_len; i++ ) {
497 netbiosns_local_name[i] = (char)lwip_toupper(hostname[i]);
498 }
499 netbiosns_local_name[copy_len] = '\0';
500 }
501 #endif /* NETBIOS_LWIP_NAME */
502
503 /**
504 * @ingroup netbiosns
505 * Stop netbios responder
506 */
507 void
netbiosns_stop(void)508 netbiosns_stop(void)
509 {
510 LWIP_ASSERT_CORE_LOCKED();
511 if (netbiosns_pcb != NULL) {
512 udp_remove(netbiosns_pcb);
513 netbiosns_pcb = NULL;
514 }
515 }
516
517 #endif /* LWIP_IPV4 && LWIP_UDP */
518