1 /*
2  * Copyright (c) 1998-2011 The TCPDUMP project
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that: (1) source code
6  * distributions retain the above copyright notice and this paragraph
7  * in its entirety, and (2) distributions including binary code include
8  * the above copyright notice and this paragraph in its entirety in
9  * the documentation or other materials provided with the distribution.
10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
11  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
12  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
13  * FOR A PARTICULAR PURPOSE.
14  *
15  * support for the The RPKI/Router Protocol as RFC6810
16  *
17  * Original code by Hannes Gredler (hannes@juniper.net)
18  */
19 
20 #define NETDISSECT_REWORKED
21 #ifdef HAVE_CONFIG_H
22 #include "config.h"
23 #endif
24 
25 #include <tcpdump-stdinc.h>
26 
27 #include <string.h>
28 
29 #include "interface.h"
30 #include "extract.h"
31 #include "addrtoname.h"
32 
33 /*
34  * RPKI/Router PDU header
35  *
36  * Here's what the PDU header looks like.
37  * The length does include the version and length fields.
38  */
39 typedef struct rpki_rtr_pdu_ {
40     u_char version;		/* Version number */
41     u_char pdu_type;		/* PDU type */
42     union {
43 	u_char session_id[2];	/* Session id */
44 	u_char error_code[2];	/* Error code */
45     } u;
46     u_char length[4];
47 } rpki_rtr_pdu;
48 #define RPKI_RTR_PDU_OVERHEAD (offsetof(rpki_rtr_pdu, rpki_rtr_pdu_msg))
49 
50 /*
51  * IPv4 Prefix PDU.
52  */
53 typedef struct rpki_rtr_pdu_ipv4_prefix_ {
54     rpki_rtr_pdu pdu_header;
55     u_char flags;
56     u_char prefix_length;
57     u_char max_length;
58     u_char zero;
59     u_char prefix[4];
60     u_char as[4];
61 } rpki_rtr_pdu_ipv4_prefix;
62 
63 /*
64  * IPv6 Prefix PDU.
65  */
66 typedef struct rpki_rtr_pdu_ipv6_prefix_ {
67     rpki_rtr_pdu pdu_header;
68     u_char flags;
69     u_char prefix_length;
70     u_char max_length;
71     u_char zero;
72     u_char prefix[16];
73     u_char as[4];
74 } rpki_rtr_pdu_ipv6_prefix;
75 
76 /*
77  * Error report PDU.
78  */
79 typedef struct rpki_rtr_pdu_error_report_ {
80     rpki_rtr_pdu pdu_header;
81     u_char encapsulated_pdu_length[4]; /* Encapsulated PDU length */
82 } rpki_rtr_pdu_error_report;
83 
84 /*
85  * PDU type codes
86  */
87 #define RPKI_RTR_SERIAL_NOTIFY_PDU	0
88 #define RPKI_RTR_SERIAL_QUERY_PDU	1
89 #define RPKI_RTR_RESET_QUERY_PDU	2
90 #define RPKI_RTR_CACHE_RESPONSE_PDU	3
91 #define RPKI_RTR_IPV4_PREFIX_PDU	4
92 #define RPKI_RTR_IPV6_PREFIX_PDU	6
93 #define RPKI_RTR_END_OF_DATA_PDU	7
94 #define RPKI_RTR_CACHE_RESET_PDU	8
95 #define RPKI_RTR_ERROR_REPORT_PDU	10
96 
97 static const struct tok rpki_rtr_pdu_values[] = {
98     { RPKI_RTR_SERIAL_NOTIFY_PDU, "Serial Notify" },
99     { RPKI_RTR_SERIAL_QUERY_PDU, "Serial Query" },
100     { RPKI_RTR_RESET_QUERY_PDU, "Reset Query" },
101     { RPKI_RTR_CACHE_RESPONSE_PDU, "Cache Response" },
102     { RPKI_RTR_IPV4_PREFIX_PDU, "IPV4 Prefix" },
103     { RPKI_RTR_IPV6_PREFIX_PDU, "IPV6 Prefix" },
104     { RPKI_RTR_END_OF_DATA_PDU, "End of Data" },
105     { RPKI_RTR_CACHE_RESET_PDU, "Cache Reset" },
106     { RPKI_RTR_ERROR_REPORT_PDU, "Error Report" },
107     { 0, NULL}
108 };
109 
110 static const struct tok rpki_rtr_error_codes[] = {
111     { 0, "Corrupt Data" },
112     { 1, "Internal Error" },
113     { 2, "No Data Available" },
114     { 3, "Invalid Request" },
115     { 4, "Unsupported Protocol Version" },
116     { 5, "Unsupported PDU Type" },
117     { 6, "Withdrawal of Unknown Record" },
118     { 7, "Duplicate Announcement Received" },
119     { 0, NULL}
120 };
121 
122 /*
123  * Build a indentation string for a given indentation level.
124  * XXX this should be really in util.c
125  */
126 static char *
indent_string(u_int indent)127 indent_string (u_int indent)
128 {
129     static char buf[20];
130     u_int idx;
131 
132     idx = 0;
133     buf[idx] = '\0';
134 
135     /*
136      * Does the static buffer fit ?
137      */
138     if (sizeof(buf) < ((indent/8) + (indent %8) + 2)) {
139 	return buf;
140     }
141 
142     /*
143      * Heading newline.
144      */
145     buf[idx] = '\n';
146     idx++;
147 
148     while (indent >= 8) {
149 	buf[idx] = '\t';
150 	idx++;
151 	indent -= 8;
152     }
153 
154     while (indent > 0) {
155 	buf[idx] = ' ';
156 	idx++;
157 	indent--;
158     }
159 
160     /*
161      * Trailing zero.
162      */
163     buf[idx] = '\0';
164 
165     return buf;
166 }
167 
168 /*
169  * Print a single PDU.
170  */
171 static void
rpki_rtr_pdu_print(netdissect_options * ndo,const u_char * tptr,u_int indent)172 rpki_rtr_pdu_print (netdissect_options *ndo, const u_char *tptr, u_int indent)
173 {
174     const rpki_rtr_pdu *pdu_header;
175     u_int pdu_type, pdu_len, hexdump;
176     const u_char *msg;
177 
178     pdu_header = (rpki_rtr_pdu *)tptr;
179     pdu_type = pdu_header->pdu_type;
180     pdu_len = EXTRACT_32BITS(pdu_header->length);
181     ND_TCHECK2(*tptr, pdu_len);
182     hexdump = FALSE;
183 
184     ND_PRINT((ndo, "%sRPKI-RTRv%u, %s PDU (%u), length: %u",
185 	   indent_string(8),
186 	   pdu_header->version,
187 	   tok2str(rpki_rtr_pdu_values, "Unknown", pdu_type),
188 	   pdu_type, pdu_len));
189 
190     switch (pdu_type) {
191 
192 	/*
193 	 * The following PDUs share the message format.
194 	 */
195     case RPKI_RTR_SERIAL_NOTIFY_PDU:
196     case RPKI_RTR_SERIAL_QUERY_PDU:
197     case RPKI_RTR_END_OF_DATA_PDU:
198         msg = (const u_char *)(pdu_header + 1);
199 	ND_PRINT((ndo, "%sSession ID: 0x%04x, Serial: %u",
200 	       indent_string(indent+2),
201 	       EXTRACT_16BITS(pdu_header->u.session_id),
202 	       EXTRACT_32BITS(msg)));
203 	break;
204 
205 	/*
206 	 * The following PDUs share the message format.
207 	 */
208     case RPKI_RTR_RESET_QUERY_PDU:
209     case RPKI_RTR_CACHE_RESET_PDU:
210 
211 	/*
212 	 * Zero payload PDUs.
213 	 */
214 	break;
215 
216     case RPKI_RTR_CACHE_RESPONSE_PDU:
217 	ND_PRINT((ndo, "%sSession ID: 0x%04x",
218 	       indent_string(indent+2),
219 	       EXTRACT_16BITS(pdu_header->u.session_id)));
220 	break;
221 
222     case RPKI_RTR_IPV4_PREFIX_PDU:
223 	{
224 	    rpki_rtr_pdu_ipv4_prefix *pdu;
225 
226 	    pdu = (rpki_rtr_pdu_ipv4_prefix *)tptr;
227 	    ND_PRINT((ndo, "%sIPv4 Prefix %s/%u-%u, origin-as %u, flags 0x%02x",
228 		   indent_string(indent+2),
229 		   ipaddr_string(ndo, pdu->prefix),
230 		   pdu->prefix_length, pdu->max_length,
231 		   EXTRACT_32BITS(pdu->as), pdu->flags));
232 	}
233 	break;
234 
235 #ifdef INET6
236     case RPKI_RTR_IPV6_PREFIX_PDU:
237 	{
238 	    rpki_rtr_pdu_ipv6_prefix *pdu;
239 
240 	    pdu = (rpki_rtr_pdu_ipv6_prefix *)tptr;
241 	    ND_PRINT((ndo, "%sIPv6 Prefix %s/%u-%u, origin-as %u, flags 0x%02x",
242 		   indent_string(indent+2),
243 		   ip6addr_string(ndo, pdu->prefix),
244 		   pdu->prefix_length, pdu->max_length,
245 		   EXTRACT_32BITS(pdu->as), pdu->flags));
246 	}
247 	break;
248 #endif
249 
250     case RPKI_RTR_ERROR_REPORT_PDU:
251 	{
252 	    rpki_rtr_pdu_error_report *pdu;
253 	    u_int encapsulated_pdu_length, text_length, tlen, error_code;
254 
255 	    pdu = (rpki_rtr_pdu_error_report *)tptr;
256 	    encapsulated_pdu_length = EXTRACT_32BITS(pdu->encapsulated_pdu_length);
257 	    ND_TCHECK2(*tptr, encapsulated_pdu_length);
258 	    tlen = pdu_len;
259 
260 	    error_code = EXTRACT_16BITS(pdu->pdu_header.u.error_code);
261 	    ND_PRINT((ndo, "%sError code: %s (%u), Encapsulated PDU length: %u",
262 		   indent_string(indent+2),
263 		   tok2str(rpki_rtr_error_codes, "Unknown", error_code),
264 		   error_code, encapsulated_pdu_length));
265 
266 	    tptr += sizeof(*pdu);
267 	    tlen -= sizeof(*pdu);
268 
269 	    /*
270 	     * Recurse if there is an encapsulated PDU.
271 	     */
272 	    if (encapsulated_pdu_length &&
273 		(encapsulated_pdu_length <= tlen)) {
274 		ND_PRINT((ndo, "%s-----encapsulated PDU-----", indent_string(indent+4)));
275 		rpki_rtr_pdu_print(ndo, tptr, indent+2);
276 	    }
277 
278 	    tptr += encapsulated_pdu_length;
279 	    tlen -= encapsulated_pdu_length;
280 
281 	    /*
282 	     * Extract, trail-zero and print the Error message.
283 	     */
284 	    text_length = 0;
285 	    if (tlen > 4) {
286 		text_length = EXTRACT_32BITS(tptr);
287 		tptr += 4;
288 		tlen -= 4;
289 	    }
290 	    ND_TCHECK2(*tptr, text_length);
291 	    if (text_length && (text_length <= tlen )) {
292 		ND_PRINT((ndo, "%sError text: ", indent_string(indent+2)));
293 		fn_printn(ndo, tptr, text_length, ndo->ndo_snapend);
294 	    }
295 	}
296 	break;
297 
298     default:
299 
300 	/*
301 	 * Unknown data, please hexdump.
302 	 */
303 	hexdump = TRUE;
304     }
305 
306     /* do we also want to see a hex dump ? */
307     if (ndo->ndo_vflag > 1 || (ndo->ndo_vflag && hexdump)) {
308 	print_unknown_data(ndo,tptr,"\n\t  ", pdu_len);
309     }
310     return;
311 
312  trunc:
313     ND_PRINT((ndo, "|trunc"));
314     return;
315 }
316 
317 void
rpki_rtr_print(netdissect_options * ndo,register const u_char * pptr,register u_int len)318 rpki_rtr_print(netdissect_options *ndo, register const u_char *pptr, register u_int len)
319 {
320     u_int tlen, pdu_type, pdu_len;
321     const u_char *tptr;
322     const rpki_rtr_pdu *pdu_header;
323 
324     tptr = pptr;
325     tlen = len;
326 
327     if (!ndo->ndo_vflag) {
328 	ND_PRINT((ndo, ", RPKI-RTR"));
329 	return;
330     }
331 
332     while (tlen >= sizeof(rpki_rtr_pdu)) {
333 
334         ND_TCHECK2(*tptr, sizeof(rpki_rtr_pdu));
335 
336 	pdu_header = (rpki_rtr_pdu *)tptr;
337         pdu_type = pdu_header->pdu_type;
338         pdu_len = EXTRACT_32BITS(pdu_header->length);
339         ND_TCHECK2(*tptr, pdu_len);
340 
341         /* infinite loop check */
342         if (!pdu_type || !pdu_len) {
343             break;
344         }
345 
346         if (tlen < pdu_len) {
347             goto trunc;
348         }
349 
350 	/*
351 	 * Print the PDU.
352 	 */
353 	rpki_rtr_pdu_print(ndo, tptr, 8);
354 
355         tlen -= pdu_len;
356         tptr += pdu_len;
357     }
358     return;
359  trunc:
360     ND_PRINT((ndo, "\n\t[|RPKI-RTR]"));
361 }
362 
363 /*
364  * Local Variables:
365  * c-style: whitesmith
366  * c-basic-offset: 4
367  * End:
368  */
369