1/*
2 * Copyright (c) 2015 Ritesh Ranjan (r.ranjan789@gmail.com)
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/* \summary: - Locator/Identifier Separation Protocol (LISP) printer */
30
31/*
32 * specification: RFC 6830
33 *
34 *
35 * The Map-Register message format is:
36 *
37 *       0                   1                   2                   3
38 *       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
39 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
40 *      |Type=3 |P|S|I|R|      Reserved               |M| Record Count  |
41 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
42 *      |                         Nonce . . .                           |
43 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
44 *      |                         . . . Nonce                           |
45 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
46 *      |            Key ID             |  Authentication Data Length   |
47 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
48 *      ~                     Authentication Data                       ~
49 *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
50 *  |   |                          Record TTL                           |
51 *  |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
52 *  R   | Locator Count | EID mask-len  | ACT |A|      Reserved         |
53 *  e   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
54 *  c   | Rsvd  |  Map-Version Number   |        EID-Prefix-AFI         |
55 *  o   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
56 *  r   |                          EID-Prefix                           |
57 *  d   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
58 *  |  /|    Priority   |    Weight     |  M Priority   |   M Weight    |
59 *  | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
60 *  | o |        Unused Flags     |L|p|R|           Loc-AFI             |
61 *  | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
62 *  |  \|                             Locator                           |
63 *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
64 *
65 *
66 * The Map-Notify message format is:
67 *
68 *       0                   1                   2                   3
69 *       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
70 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
71 *      |Type=4 |I|R|          Reserved                 | Record Count  |
72 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
73 *      |                         Nonce . . .                           |
74 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
75 *      |                         . . . Nonce                           |
76 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
77 *      |            Key ID             |  Authentication Data Length   |
78 *      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
79 *      ~                     Authentication Data                       ~
80 *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
81 *  |   |                          Record TTL                           |
82 *  |   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
83 *  R   | Locator Count | EID mask-len  | ACT |A|      Reserved         |
84 *  e   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
85 *  c   | Rsvd  |  Map-Version Number   |         EID-Prefix-AFI        |
86 *  o   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
87 *  r   |                          EID-Prefix                           |
88 *  d   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
89 *  |  /|    Priority   |    Weight     |  M Priority   |   M Weight    |
90 *  | L +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
91 *  | o |        Unused Flags     |L|p|R|           Loc-AFI             |
92 *  | c +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
93 *  |  \|                             Locator                           |
94 *  +-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
95 */
96
97#ifdef HAVE_CONFIG_H
98#include <config.h>
99#endif
100
101#include "netdissect-stdinc.h"
102#include "netdissect.h"
103
104#include "ip.h"
105#include "ip6.h"
106
107#include "extract.h"
108#include "addrtoname.h"
109
110
111#define IPv4_AFI			1
112#define IPv6_AFI			2
113#define TYPE_INDEX			4
114#define LISP_MAP_NOTIFY_IBIT_MASK	8
115#define LISP_MAP_REGISTER_IBIT_MASK	2
116
117enum {
118	LISP_MAP_REQUEST = 1,
119	LISP_MAP_REPLY,
120	LISP_MAP_REGISTER,
121	LISP_MAP_NOTIFY,
122	LISP_ENCAPSULATED_CONTROL_MESSAGE = 8
123};
124
125enum {
126	LISP_AUTH_NONE,
127	LISP_AUTH_SHA1,
128	LISP_AUTH_SHA256
129};
130
131static const struct tok lisp_type [] = {
132	{ 0, "LISP-Reserved"			},
133	{ 1, "LISP-Map-Request"			},
134	{ 2, "LISP-Map-Reply"			},
135	{ 3, "LISP-Map-Register"		},
136	{ 4, "LISP-Map-Notify"			},
137	{ 8, "LISP-Encapsulated-Contol-Message" },
138	{ 0, NULL }
139};
140
141/*
142 * P-Bit : Request for Proxy Map-Reply from the MS/MR
143 * S-Bit : Security Enhancement. ETR is LISP-SEC enabled. draft-ietf-lisp-sec
144 * I-Bit : 128 bit xTR-ID and 64 bit Site-ID present.
145 *	   xTR-ID and Site-ID help in differentiation of xTRs in multi xTR
146 *	   and multi Site deployment scenarios.
147 * R-Bit : Built for a Reencapsulating-Tunnel-Router. Used in Traffic
148 *	   Engineering and Service Chaining
149 */
150static const struct tok map_register_hdr_flag[] = {
151	{ 0x08000000, "P-Proxy-Map-Reply"  },
152	{ 0x04000000, "S-LISP-SEC-Capable" },
153	{ 0x02000000, "I-xTR-ID-Present"   },
154	{ 0x01000000, "R-Build-For-RTR"    },
155	{ 0x00000100, "M-Want-Map-Notify"  },
156	{ 0, NULL }
157};
158
159static const struct tok map_notify_hdr_flag[] = {
160	{ 0x08000000, "I-xTR-ID-Present"   },
161	{ 0x04000000, "R-Build-For-RTR"    },
162	{ 0, NULL }
163};
164
165static const struct tok auth_type[] = {
166	{ LISP_AUTH_NONE,   "None"   },
167	{ LISP_AUTH_SHA1,   "SHA1"   },
168	{ LISP_AUTH_SHA256, "SHA256" },
169	{ 0, NULL}
170};
171
172static const struct tok lisp_eid_action[] = {
173	{ 0, "No-Action"	},
174	{ 1, "Natively-Forward" },
175	{ 2, "Send-Map-Request" },
176	{ 3, "Drop"		},
177	{ 0, NULL}
178};
179
180static const struct tok lisp_loc_flag[] = {
181	{ 0x0004, "Local-Locator" },
182	{ 0x0002, "RLoc-Probed"	  },
183	{ 0x0001, "Reachable"	  },
184	{ 0, NULL }
185};
186
187typedef struct map_register_hdr {
188	nd_uint8_t type_and_flag;
189	nd_uint8_t reserved;
190	nd_uint8_t reserved_and_flag2;
191	nd_uint8_t record_count;
192	nd_uint64_t nonce;
193	nd_uint16_t key_id;
194	nd_uint16_t auth_data_len;
195} lisp_map_register_hdr;
196
197#define MAP_REGISTER_HDR_LEN sizeof(lisp_map_register_hdr)
198
199typedef struct map_register_eid {
200	nd_uint32_t ttl;
201	nd_uint8_t locator_count;
202	nd_uint8_t eid_prefix_mask_length;
203	nd_uint8_t act_auth_inc_res;
204	nd_uint8_t reserved;
205	nd_uint16_t reserved_and_version;
206	nd_uint16_t eid_prefix_afi;
207} lisp_map_register_eid;
208
209#define MAP_REGISTER_EID_LEN sizeof(lisp_map_register_eid)
210
211typedef struct map_register_loc {
212	nd_uint8_t priority;
213	nd_uint8_t weight;
214	nd_uint8_t m_priority;
215	nd_uint8_t m_weight;
216	nd_uint16_t unused_and_flag;
217	nd_uint16_t locator_afi;
218} lisp_map_register_loc;
219
220#define MAP_REGISTER_LOC_LEN sizeof(lisp_map_register_loc)
221
222static uint8_t extract_lisp_type(uint8_t);
223static uint8_t is_xtr_data_present(uint8_t, uint8_t);
224static void lisp_hdr_flag(netdissect_options *, const lisp_map_register_hdr *);
225static void action_flag(netdissect_options *, uint8_t);
226static void loc_hdr_flag(netdissect_options *, uint16_t);
227
228void
229lisp_print(netdissect_options *ndo, const u_char *bp, u_int length)
230{
231	uint8_t type_and_flag;
232	uint8_t type;
233	uint8_t mask_len;
234	uint8_t loc_count;
235	uint8_t xtr_present;
236	uint8_t record_count;
237	uint16_t key_id;
238	uint16_t eid_afi;
239	uint16_t loc_afi;
240	uint16_t map_version;
241	uint16_t packet_offset;
242	uint16_t auth_data_len;
243	uint32_t ttl;
244	const u_char *packet_iterator;
245	const u_char *loc_ip_pointer;
246	const lisp_map_register_hdr *lisp_hdr;
247	const lisp_map_register_eid *lisp_eid;
248	const lisp_map_register_loc *lisp_loc;
249
250	ndo->ndo_protocol = "lisp";
251	/* Check if enough bytes for header are available */
252	ND_TCHECK_LEN(bp, MAP_REGISTER_HDR_LEN);
253	lisp_hdr = (const lisp_map_register_hdr *) bp;
254	lisp_hdr_flag(ndo, lisp_hdr);
255	/* Supporting only MAP NOTIFY and MAP REGISTER LISP packets */
256	type_and_flag = GET_U_1(lisp_hdr->type_and_flag);
257	type = extract_lisp_type(type_and_flag);
258	if ((type != LISP_MAP_REGISTER) && (type != LISP_MAP_NOTIFY))
259		return;
260
261	/* Find if the packet contains xTR and Site-ID data */
262	xtr_present = is_xtr_data_present(type, type_and_flag);
263
264	/* Extract the number of EID records present */
265	auth_data_len = GET_BE_U_2(lisp_hdr->auth_data_len);
266	packet_iterator = (const u_char *)(lisp_hdr);
267	packet_offset = MAP_REGISTER_HDR_LEN;
268	record_count = GET_U_1(lisp_hdr->record_count);
269
270	if (ndo->ndo_vflag) {
271		key_id = GET_BE_U_2(lisp_hdr->key_id);
272		ND_PRINT("\n    %u record(s), ", record_count);
273		ND_PRINT("Authentication %s,",
274			tok2str(auth_type, "unknown-type", key_id));
275		hex_print(ndo, "\n    Authentication-Data: ", packet_iterator +
276						packet_offset, auth_data_len);
277	} else {
278		ND_PRINT(" %u record(s),", record_count);
279	}
280	packet_offset += auth_data_len;
281
282	if (record_count == 0)
283		goto invalid;
284
285	/* Print all the EID records */
286	while ((length > packet_offset) && (record_count != 0)) {
287		record_count--;
288		ND_TCHECK_LEN(packet_iterator + packet_offset,
289			      MAP_REGISTER_EID_LEN);
290		ND_PRINT("\n");
291		lisp_eid = (const lisp_map_register_eid *)
292				((const u_char *)lisp_hdr + packet_offset);
293		packet_offset += MAP_REGISTER_EID_LEN;
294		mask_len = GET_U_1(lisp_eid->eid_prefix_mask_length);
295		eid_afi = GET_BE_U_2(lisp_eid->eid_prefix_afi);
296		loc_count = GET_U_1(lisp_eid->locator_count);
297
298		if (ndo->ndo_vflag) {
299			ttl = GET_BE_U_4(lisp_eid->ttl);
300			ND_PRINT("      Record TTL %u,", ttl);
301			action_flag(ndo, GET_U_1(lisp_eid->act_auth_inc_res));
302			map_version = GET_BE_U_2(lisp_eid->reserved_and_version) & 0x0FFF;
303			ND_PRINT(" Map Version: %u,", map_version);
304		}
305
306		switch (eid_afi) {
307		case IPv4_AFI:
308			ND_PRINT(" EID %s/%u,",
309				GET_IPADDR_STRING(packet_iterator + packet_offset),
310				mask_len);
311			packet_offset += 4;
312			break;
313		case IPv6_AFI:
314			ND_PRINT(" EID %s/%u,",
315				GET_IP6ADDR_STRING(packet_iterator + packet_offset),
316				mask_len);
317			packet_offset += 16;
318			break;
319		default:
320			/*
321			 * No support for LCAF right now.
322			 */
323			return;
324			break;
325		}
326
327		ND_PRINT(" %u locator(s)", loc_count);
328
329		while (loc_count != 0) {
330			loc_count--;
331			ND_TCHECK_LEN(packet_iterator + packet_offset,
332				      MAP_REGISTER_LOC_LEN);
333			lisp_loc = (const lisp_map_register_loc *) (packet_iterator + packet_offset);
334			loc_ip_pointer = (const u_char *) (lisp_loc + 1);
335			packet_offset += MAP_REGISTER_LOC_LEN;
336			loc_afi = GET_BE_U_2(lisp_loc->locator_afi);
337
338			if (ndo->ndo_vflag)
339				ND_PRINT("\n       ");
340
341			switch (loc_afi) {
342			case IPv4_AFI:
343				ND_TCHECK_4(packet_iterator + packet_offset);
344				ND_PRINT(" LOC %s", GET_IPADDR_STRING(loc_ip_pointer));
345				packet_offset += 4;
346				break;
347			case IPv6_AFI:
348				ND_TCHECK_16(packet_iterator + packet_offset);
349				ND_PRINT(" LOC %s", GET_IP6ADDR_STRING(loc_ip_pointer));
350				packet_offset += 16;
351				break;
352			default:
353				break;
354			}
355			if (ndo->ndo_vflag) {
356				ND_PRINT("\n          Priority/Weight %u/%u,"
357						" Multicast Priority/Weight %u/%u,",
358						GET_U_1(lisp_loc->priority),
359						GET_U_1(lisp_loc->weight),
360						GET_U_1(lisp_loc->m_priority),
361						GET_U_1(lisp_loc->m_weight));
362				loc_hdr_flag(ndo,
363					     GET_BE_U_2(lisp_loc->unused_and_flag));
364			}
365		}
366	}
367
368	/*
369	 * Print xTR and Site ID. Handle the fact that the packet could be invalid.
370	 * If the xTR_ID_Present bit is not set, and we still have data to display,
371	 * show it as hex data.
372	 */
373	if (xtr_present) {
374		if (!ND_TTEST_LEN(packet_iterator + packet_offset, 24))
375			goto invalid;
376		hex_print(ndo, "\n    xTR-ID: ", packet_iterator + packet_offset, 16);
377		ND_PRINT("\n    SITE-ID: %" PRIu64,
378			GET_BE_U_8(packet_iterator + packet_offset + 16));
379	} else {
380		/* Check if packet isn't over yet */
381		if (packet_iterator + packet_offset < ndo->ndo_snapend) {
382			hex_print(ndo, "\n    Data: ", packet_iterator + packet_offset,
383				ND_BYTES_AVAILABLE_AFTER(packet_iterator + packet_offset));
384		}
385	}
386	return;
387trunc:
388	nd_print_trunc(ndo);
389	return;
390invalid:
391	nd_print_invalid(ndo);
392}
393
394static uint8_t
395extract_lisp_type(uint8_t lisp_hdr_flags)
396{
397	return (lisp_hdr_flags) >> TYPE_INDEX;
398}
399
400static uint8_t
401is_xtr_data_present(uint8_t type, uint8_t lisp_hdr_flags)
402{
403	uint8_t xtr_present = 0;
404
405	if (type == LISP_MAP_REGISTER)
406		xtr_present = (lisp_hdr_flags) & LISP_MAP_REGISTER_IBIT_MASK;
407	else if (type == LISP_MAP_NOTIFY)
408		xtr_present = (lisp_hdr_flags) & LISP_MAP_NOTIFY_IBIT_MASK;
409
410	return xtr_present;
411}
412
413static void lisp_hdr_flag(netdissect_options *ndo, const lisp_map_register_hdr *lisp_hdr)
414{
415	uint8_t type = extract_lisp_type(GET_U_1(lisp_hdr->type_and_flag));
416
417	if (!ndo->ndo_vflag) {
418		ND_PRINT("%s,", tok2str(lisp_type, "unknown-type-%u", type));
419		return;
420	} else {
421		ND_PRINT("%s,", tok2str(lisp_type, "unknown-type-%u", type));
422	}
423
424	if (type == LISP_MAP_REGISTER) {
425		ND_PRINT(" flags [%s],", bittok2str(map_register_hdr_flag,
426			 "none", GET_BE_U_4(lisp_hdr)));
427	} else if (type == LISP_MAP_NOTIFY) {
428		ND_PRINT(" flags [%s],", bittok2str(map_notify_hdr_flag,
429			 "none", GET_BE_U_4(lisp_hdr)));
430	}
431}
432
433static void action_flag(netdissect_options *ndo, uint8_t act_auth_inc_res)
434{
435	uint8_t action;
436	uint8_t authoritative;
437
438	authoritative  = ((act_auth_inc_res >> 4) & 1);
439
440	if (authoritative)
441		ND_PRINT(" Authoritative,");
442	else
443		ND_PRINT(" Non-Authoritative,");
444
445	action = act_auth_inc_res >> 5;
446	ND_PRINT(" %s,", tok2str(lisp_eid_action, "unknown", action));
447}
448
449static void loc_hdr_flag(netdissect_options *ndo, uint16_t flag)
450{
451	ND_PRINT(" flags [%s],", bittok2str(lisp_loc_flag, "none", flag));
452}
453
454