/*
* Copyright (c) 1998-2011 The TCPDUMP project
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code
* distributions retain the above copyright notice and this paragraph
* in its entirety, and (2) distributions including binary code include
* the above copyright notice and this paragraph in its entirety in
* the documentation or other materials provided with the distribution.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND
* WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
* LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE.
*
* Original code by Hannes Gredler (hannes@gredler.at)
*/
/* \summary: Resource Public Key Infrastructure (RPKI) to Router Protocol printer */
/* specification: RFC 6810 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <netdissect-stdinc.h>
#include <string.h>
#include "netdissect.h"
#include "extract.h"
#include "addrtoname.h"
static const char tstr[] = "[|RPKI-RTR]";
/*
* RPKI/Router PDU header
*
* Here's what the PDU header looks like.
* The length does include the version and length fields.
*/
typedef struct rpki_rtr_pdu_ {
u_char version; /* Version number */
u_char pdu_type; /* PDU type */
union {
u_char session_id[2]; /* Session id */
u_char error_code[2]; /* Error code */
} u;
u_char length[4];
} rpki_rtr_pdu;
#define RPKI_RTR_PDU_OVERHEAD (offsetof(rpki_rtr_pdu, rpki_rtr_pdu_msg))
/*
* IPv4 Prefix PDU.
*/
typedef struct rpki_rtr_pdu_ipv4_prefix_ {
rpki_rtr_pdu pdu_header;
u_char flags;
u_char prefix_length;
u_char max_length;
u_char zero;
u_char prefix[4];
u_char as[4];
} rpki_rtr_pdu_ipv4_prefix;
/*
* IPv6 Prefix PDU.
*/
typedef struct rpki_rtr_pdu_ipv6_prefix_ {
rpki_rtr_pdu pdu_header;
u_char flags;
u_char prefix_length;
u_char max_length;
u_char zero;
u_char prefix[16];
u_char as[4];
} rpki_rtr_pdu_ipv6_prefix;
/*
* Error report PDU.
*/
typedef struct rpki_rtr_pdu_error_report_ {
rpki_rtr_pdu pdu_header;
u_char encapsulated_pdu_length[4]; /* Encapsulated PDU length */
/* Copy of Erroneous PDU (variable, optional) */
/* Length of Error Text (4 octets in network byte order) */
/* Arbitrary Text of Error Diagnostic Message (variable, optional) */
} rpki_rtr_pdu_error_report;
/*
* PDU type codes
*/
#define RPKI_RTR_SERIAL_NOTIFY_PDU 0
#define RPKI_RTR_SERIAL_QUERY_PDU 1
#define RPKI_RTR_RESET_QUERY_PDU 2
#define RPKI_RTR_CACHE_RESPONSE_PDU 3
#define RPKI_RTR_IPV4_PREFIX_PDU 4
#define RPKI_RTR_IPV6_PREFIX_PDU 6
#define RPKI_RTR_END_OF_DATA_PDU 7
#define RPKI_RTR_CACHE_RESET_PDU 8
#define RPKI_RTR_ERROR_REPORT_PDU 10
static const struct tok rpki_rtr_pdu_values[] = {
{ RPKI_RTR_SERIAL_NOTIFY_PDU, "Serial Notify" },
{ RPKI_RTR_SERIAL_QUERY_PDU, "Serial Query" },
{ RPKI_RTR_RESET_QUERY_PDU, "Reset Query" },
{ RPKI_RTR_CACHE_RESPONSE_PDU, "Cache Response" },
{ RPKI_RTR_IPV4_PREFIX_PDU, "IPV4 Prefix" },
{ RPKI_RTR_IPV6_PREFIX_PDU, "IPV6 Prefix" },
{ RPKI_RTR_END_OF_DATA_PDU, "End of Data" },
{ RPKI_RTR_CACHE_RESET_PDU, "Cache Reset" },
{ RPKI_RTR_ERROR_REPORT_PDU, "Error Report" },
{ 0, NULL}
};
static const struct tok rpki_rtr_error_codes[] = {
{ 0, "Corrupt Data" },
{ 1, "Internal Error" },
{ 2, "No Data Available" },
{ 3, "Invalid Request" },
{ 4, "Unsupported Protocol Version" },
{ 5, "Unsupported PDU Type" },
{ 6, "Withdrawal of Unknown Record" },
{ 7, "Duplicate Announcement Received" },
{ 0, NULL}
};
/*
* Build a indentation string for a given indentation level.
* XXX this should be really in util.c
*/
static char *
indent_string (u_int indent)
{
static char buf[20];
u_int idx;
idx = 0;
buf[idx] = '\0';
/*
* Does the static buffer fit ?
*/
if (sizeof(buf) < ((indent/8) + (indent %8) + 2)) {
return buf;
}
/*
* Heading newline.
*/
buf[idx] = '\n';
idx++;
while (indent >= 8) {
buf[idx] = '\t';
idx++;
indent -= 8;
}
while (indent > 0) {
buf[idx] = ' ';
idx++;
indent--;
}
/*
* Trailing zero.
*/
buf[idx] = '\0';
return buf;
}
/*
* Print a single PDU.
*/
static u_int
rpki_rtr_pdu_print (netdissect_options *ndo, const u_char *tptr, const u_int len,
const u_char recurse, const u_int indent)
{
const rpki_rtr_pdu *pdu_header;
u_int pdu_type, pdu_len, hexdump;
const u_char *msg;
/* Protocol Version */
ND_TCHECK_8BITS(tptr);
if (*tptr != 0) {
/* Skip the rest of the input buffer because even if this is
* a well-formed PDU of a future RPKI-Router protocol version
* followed by a well-formed PDU of RPKI-Router protocol
* version 0, there is no way to know exactly how to skip the
* current PDU.
*/
ND_PRINT((ndo, "%sRPKI-RTRv%u (unknown)", indent_string(8), *tptr));
return len;
}
if (len < sizeof(rpki_rtr_pdu)) {
ND_PRINT((ndo, "(%u bytes is too few to decode)", len));
goto invalid;
}
ND_TCHECK2(*tptr, sizeof(rpki_rtr_pdu));
pdu_header = (const rpki_rtr_pdu *)tptr;
pdu_type = pdu_header->pdu_type;
pdu_len = EXTRACT_32BITS(pdu_header->length);
/* Do not check bounds with pdu_len yet, do it in the case blocks
* below to make it possible to decode at least the beginning of
* a truncated Error Report PDU or a truncated encapsulated PDU.
*/
hexdump = FALSE;
ND_PRINT((ndo, "%sRPKI-RTRv%u, %s PDU (%u), length: %u",
indent_string(8),
pdu_header->version,
tok2str(rpki_rtr_pdu_values, "Unknown", pdu_type),
pdu_type, pdu_len));
if (pdu_len < sizeof(rpki_rtr_pdu) || pdu_len > len)
goto invalid;
switch (pdu_type) {
/*
* The following PDUs share the message format.
*/
case RPKI_RTR_SERIAL_NOTIFY_PDU:
case RPKI_RTR_SERIAL_QUERY_PDU:
case RPKI_RTR_END_OF_DATA_PDU:
if (pdu_len != sizeof(rpki_rtr_pdu) + 4)
goto invalid;
ND_TCHECK2(*tptr, pdu_len);
msg = (const u_char *)(pdu_header + 1);
ND_PRINT((ndo, "%sSession ID: 0x%04x, Serial: %u",
indent_string(indent+2),
EXTRACT_16BITS(pdu_header->u.session_id),
EXTRACT_32BITS(msg)));
break;
/*
* The following PDUs share the message format.
*/
case RPKI_RTR_RESET_QUERY_PDU:
case RPKI_RTR_CACHE_RESET_PDU:
if (pdu_len != sizeof(rpki_rtr_pdu))
goto invalid;
/* no additional boundary to check */
/*
* Zero payload PDUs.
*/
break;
case RPKI_RTR_CACHE_RESPONSE_PDU:
if (pdu_len != sizeof(rpki_rtr_pdu))
goto invalid;
/* no additional boundary to check */
ND_PRINT((ndo, "%sSession ID: 0x%04x",
indent_string(indent+2),
EXTRACT_16BITS(pdu_header->u.session_id)));
break;
case RPKI_RTR_IPV4_PREFIX_PDU:
{
const rpki_rtr_pdu_ipv4_prefix *pdu;
if (pdu_len != sizeof(rpki_rtr_pdu) + 12)
goto invalid;
ND_TCHECK2(*tptr, pdu_len);
pdu = (const rpki_rtr_pdu_ipv4_prefix *)tptr;
ND_PRINT((ndo, "%sIPv4 Prefix %s/%u-%u, origin-as %u, flags 0x%02x",
indent_string(indent+2),
ipaddr_string(ndo, pdu->prefix),
pdu->prefix_length, pdu->max_length,
EXTRACT_32BITS(pdu->as), pdu->flags));
}
break;
case RPKI_RTR_IPV6_PREFIX_PDU:
{
const rpki_rtr_pdu_ipv6_prefix *pdu;
if (pdu_len != sizeof(rpki_rtr_pdu) + 24)
goto invalid;
ND_TCHECK2(*tptr, pdu_len);
pdu = (const rpki_rtr_pdu_ipv6_prefix *)tptr;
ND_PRINT((ndo, "%sIPv6 Prefix %s/%u-%u, origin-as %u, flags 0x%02x",
indent_string(indent+2),
ip6addr_string(ndo, pdu->prefix),
pdu->prefix_length, pdu->max_length,
EXTRACT_32BITS(pdu->as), pdu->flags));
}
break;
case RPKI_RTR_ERROR_REPORT_PDU:
{
const rpki_rtr_pdu_error_report *pdu;
u_int encapsulated_pdu_length, text_length, tlen, error_code;
tlen = sizeof(rpki_rtr_pdu);
/* Do not test for the "Length of Error Text" data element yet. */
if (pdu_len < tlen + 4)
goto invalid;
ND_TCHECK2(*tptr, tlen + 4);
/* Safe up to and including the "Length of Encapsulated PDU"
* data element, more data elements may be present.
*/
pdu = (const rpki_rtr_pdu_error_report *)tptr;
encapsulated_pdu_length = EXTRACT_32BITS(pdu->encapsulated_pdu_length);
tlen += 4;
error_code = EXTRACT_16BITS(pdu->pdu_header.u.error_code);
ND_PRINT((ndo, "%sError code: %s (%u), Encapsulated PDU length: %u",
indent_string(indent+2),
tok2str(rpki_rtr_error_codes, "Unknown", error_code),
error_code, encapsulated_pdu_length));
if (encapsulated_pdu_length) {
/* Section 5.10 of RFC 6810 says:
* "An Error Report PDU MUST NOT be sent for an Error Report PDU."
*
* However, as far as the protocol encoding goes Error Report PDUs can
* happen to be nested in each other, however many times, in which case
* the decoder should still print such semantically incorrect PDUs.
*
* That said, "the Erroneous PDU field MAY be truncated" (ibid), thus
* to keep things simple this implementation decodes only the two
* outermost layers of PDUs and makes bounds checks in the outer and
* the inner PDU independently.
*/
if (pdu_len < tlen + encapsulated_pdu_length)
goto invalid;
if (! recurse) {
ND_TCHECK2(*tptr, tlen + encapsulated_pdu_length);
}
else {
ND_PRINT((ndo, "%s-----encapsulated PDU-----", indent_string(indent+4)));
rpki_rtr_pdu_print(ndo, tptr + tlen,
encapsulated_pdu_length, 0, indent + 2);
}
tlen += encapsulated_pdu_length;
}
if (pdu_len < tlen + 4)
goto invalid;
ND_TCHECK2(*tptr, tlen + 4);
/* Safe up to and including the "Length of Error Text" data element,
* one more data element may be present.
*/
/*
* Extract, trail-zero and print the Error message.
*/
text_length = EXTRACT_32BITS(tptr + tlen);
tlen += 4;
if (text_length) {
if (pdu_len < tlen + text_length)
goto invalid;
/* fn_printn() makes the bounds check */
ND_PRINT((ndo, "%sError text: ", indent_string(indent+2)));
if (fn_printn(ndo, tptr + tlen, text_length, ndo->ndo_snapend))
goto trunc;
}
}
break;
default:
ND_TCHECK2(*tptr, pdu_len);
/*
* Unknown data, please hexdump.
*/
hexdump = TRUE;
}
/* do we also want to see a hex dump ? */
if (ndo->ndo_vflag > 1 || (ndo->ndo_vflag && hexdump)) {
print_unknown_data(ndo,tptr,"\n\t ", pdu_len);
}
return pdu_len;
invalid:
ND_PRINT((ndo, "%s", istr));
ND_TCHECK2(*tptr, len);
return len;
trunc:
ND_PRINT((ndo, "\n\t%s", tstr));
return len;
}
void
rpki_rtr_print(netdissect_options *ndo, register const u_char *pptr, register u_int len)
{
if (!ndo->ndo_vflag) {
ND_PRINT((ndo, ", RPKI-RTR"));
return;
}
while (len) {
u_int pdu_len = rpki_rtr_pdu_print(ndo, pptr, len, 1, 8);
len -= pdu_len;
pptr += pdu_len;
}
}
/*
* Local Variables:
* c-style: whitesmith
* c-basic-offset: 4
* End:
*/