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bird/proto/rpki/packets.c
Job Snijders b9f38727a7 RPKI: Add contextual out-of-bound checks in RTR Prefix PDU handler 
RFC 6810 and RFC 8210 specify that the "Max Length" value MUST NOT be
less than the Prefix Length element (underflow). On the other side,
overflow of the Max Length element also is possible, it being an 8-bit
unsigned integer allows for values larger than 32 or 128. This also
implicitly ensures there is no overflow of "Length" value.

When a PDU is received where the Max Length field is corrputed, the RTR
client (BIRD) should immediately terminate the session, flush all data
learned from that cache, and log an error for the operator.

Minor changes done by commiter.
2021-12-18 16:35:28 +01:00

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/*
* BIRD -- The Resource Public Key Infrastructure (RPKI) to Router Protocol
*
* (c) 2015 CZ.NIC
* (c) 2015 Pavel Tvrdik <pawel.tvrdik@gmail.com>
*
* This file was a part of RTRlib: http://rpki.realmv6.org/
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#undef LOCAL_DEBUG
#include "rpki.h"
#include "transport.h"
#include "packets.h"
#define RPKI_ADD_FLAG 0b00000001
enum rpki_transmit_type {
RPKI_RECV = 0,
RPKI_SEND = 1,
};
enum pdu_error_type {
CORRUPT_DATA = 0,
INTERNAL_ERROR = 1,
NO_DATA_AVAIL = 2,
INVALID_REQUEST = 3,
UNSUPPORTED_PROTOCOL_VER = 4,
UNSUPPORTED_PDU_TYPE = 5,
WITHDRAWAL_OF_UNKNOWN_RECORD = 6,
DUPLICATE_ANNOUNCEMENT = 7,
PDU_TOO_BIG = 32
};
static const char *str_pdu_error_type[] = {
[CORRUPT_DATA] = "Corrupt-Data",
[INTERNAL_ERROR] = "Internal-Error",
[NO_DATA_AVAIL] = "No-Data-Available",
[INVALID_REQUEST] = "Invalid-Request",
[UNSUPPORTED_PROTOCOL_VER] = "Unsupported-Protocol-Version",
[UNSUPPORTED_PDU_TYPE] = "Unsupported-PDU-Type",
[WITHDRAWAL_OF_UNKNOWN_RECORD]= "Withdrawal-Of-Unknown-Record",
[DUPLICATE_ANNOUNCEMENT] = "Duplicate-Announcement",
[PDU_TOO_BIG] = "PDU-Too-Big",
};
enum pdu_type {
SERIAL_NOTIFY = 0,
SERIAL_QUERY = 1,
RESET_QUERY = 2,
CACHE_RESPONSE = 3,
IPV4_PREFIX = 4,
RESERVED = 5,
IPV6_PREFIX = 6,
END_OF_DATA = 7,
CACHE_RESET = 8,
ROUTER_KEY = 9,
ERROR = 10,
PDU_TYPE_MAX
};
static const char *str_pdu_type_[] = {
[SERIAL_NOTIFY] = "Serial Notify",
[SERIAL_QUERY] = "Serial Query",
[RESET_QUERY] = "Reset Query",
[CACHE_RESPONSE] = "Cache Response",
[IPV4_PREFIX] = "IPv4 Prefix",
[RESERVED] = "Reserved",
[IPV6_PREFIX] = "IPv6 Prefix",
[END_OF_DATA] = "End of Data",
[CACHE_RESET] = "Cache Reset",
[ROUTER_KEY] = "Router Key",
[ERROR] = "Error"
};
static const char *str_pdu_type(uint type) {
if (type < PDU_TYPE_MAX)
return str_pdu_type_[type];
else
return "Undefined packet type";
}
/*
* 0 8 16 24 31
* .-------------------------------------------.
* | Protocol | PDU | |
* | Version | Type | reserved = zero |
* | 0 or 1 | 0 - 10 | |
* +-------------------------------------------+
* | |
* | Length >= 8 |
* | |
* `-------------------------------------------' */
struct pdu_header {
u8 ver;
u8 type;
u16 reserved;
u32 len;
} PACKED;
struct pdu_cache_response {
u8 ver;
u8 type;
u16 session_id;
u32 len;
} PACKED;
struct pdu_serial_notify {
u8 ver;
u8 type;
u16 session_id;
u32 len;
u32 serial_num;
} PACKED;
struct pdu_serial_query {
u8 ver;
u8 type;
u16 session_id;
u32 len;
u32 serial_num;
} PACKED;
struct pdu_ipv4 {
u8 ver;
u8 type;
u16 reserved;
u32 len;
u8 flags;
u8 prefix_len;
u8 max_prefix_len;
u8 zero;
ip4_addr prefix;
u32 asn;
} PACKED;
struct pdu_ipv6 {
u8 ver;
u8 type;
u16 reserved;
u32 len;
u8 flags;
u8 prefix_len;
u8 max_prefix_len;
u8 zero;
ip6_addr prefix;
u32 asn;
} PACKED;
/*
* 0 8 16 24 31
* .-------------------------------------------.
* | Protocol | PDU | |
* | Version | Type | Error Code |
* | 1 | 10 | |
* +-------------------------------------------+
* | |
* | Length |
* | |
* +-------------------------------------------+
* | |
* | Length of Encapsulated PDU |
* | |
* +-------------------------------------------+
* | |
* ~ Copy of Erroneous PDU ~
* | |
* +-------------------------------------------+
* | |
* | Length of Error Text |
* | |
* +-------------------------------------------+
* | |
* | Arbitrary Text |
* | of |
* ~ Error Diagnostic Message ~
* | |
* `-------------------------------------------' */
struct pdu_error {
u8 ver;
u8 type;
u16 error_code;
u32 len;
u32 len_enc_pdu; /* Length of Encapsulated PDU */
byte rest[]; /* Copy of Erroneous PDU
* Length of Error Text
* Error Diagnostic Message */
} PACKED;
struct pdu_reset_query {
u8 ver;
u8 type;
u16 flags;
u32 len;
} PACKED;
struct pdu_end_of_data_v0 {
u8 ver;
u8 type;
u16 session_id;
u32 len;
u32 serial_num;
} PACKED;
struct pdu_end_of_data_v1 {
u8 ver;
u8 type;
u16 session_id;
u32 len;
u32 serial_num;
u32 refresh_interval;
u32 retry_interval;
u32 expire_interval;
} PACKED;
static const size_t min_pdu_size[] = {
[SERIAL_NOTIFY] = sizeof(struct pdu_serial_notify),
[SERIAL_QUERY] = sizeof(struct pdu_serial_query),
[RESET_QUERY] = sizeof(struct pdu_reset_query),
[CACHE_RESPONSE] = sizeof(struct pdu_cache_response),
[IPV4_PREFIX] = sizeof(struct pdu_ipv4),
[RESERVED] = sizeof(struct pdu_header),
[IPV6_PREFIX] = sizeof(struct pdu_ipv6),
[END_OF_DATA] = sizeof(struct pdu_end_of_data_v0),
[CACHE_RESET] = sizeof(struct pdu_cache_response),
[ROUTER_KEY] = sizeof(struct pdu_header), /* FIXME */
[ERROR] = 16,
};
static int rpki_send_error_pdu(struct rpki_cache *cache, const enum pdu_error_type error_code, const u32 err_pdu_len, const struct pdu_header *erroneous_pdu, const char *fmt, ...);
static void
rpki_pdu_to_network_byte_order(struct pdu_header *pdu)
{
pdu->reserved = htons(pdu->reserved);
pdu->len = htonl(pdu->len);
switch (pdu->type)
{
case SERIAL_QUERY:
{
/* Note that a session_id is converted using converting header->reserved */
struct pdu_serial_query *sq_pdu = (void *) pdu;
sq_pdu->serial_num = htonl(sq_pdu->serial_num);
break;
}
case ERROR:
{
struct pdu_error *err = (void *) pdu;
u32 *err_text_len = (u32 *)(err->rest + err->len_enc_pdu);
*err_text_len = htonl(*err_text_len);
err->len_enc_pdu = htonl(err->len_enc_pdu);
break;
}
case RESET_QUERY:
break;
default:
bug("PDU type %s should not be sent by us", str_pdu_type(pdu->type));
}
}
static void
rpki_pdu_to_host_byte_order(struct pdu_header *pdu)
{
/* The Router Key PDU has two one-byte fields instead of one two-bytes field. */
if (pdu->type != ROUTER_KEY)
pdu->reserved = ntohs(pdu->reserved);
pdu->len = ntohl(pdu->len);
switch (pdu->type)
{
case SERIAL_NOTIFY:
{
/* Note that a session_id is converted using converting header->reserved */
struct pdu_serial_notify *sn_pdu = (void *) pdu;
sn_pdu->serial_num = ntohl(sn_pdu->serial_num);
break;
}
case END_OF_DATA:
{
/* Note that a session_id is converted using converting header->reserved */
struct pdu_end_of_data_v0 *eod0 = (void *) pdu;
eod0->serial_num = ntohl(eod0->serial_num); /* Same either for version 1 */
if (pdu->ver == RPKI_VERSION_1)
{
struct pdu_end_of_data_v1 *eod1 = (void *) pdu;
eod1->expire_interval = ntohl(eod1->expire_interval);
eod1->refresh_interval = ntohl(eod1->refresh_interval);
eod1->retry_interval = ntohl(eod1->retry_interval);
}
break;
}
case IPV4_PREFIX:
{
struct pdu_ipv4 *ipv4 = (void *) pdu;
ipv4->prefix = ip4_ntoh(ipv4->prefix);
ipv4->asn = ntohl(ipv4->asn);
break;
}
case IPV6_PREFIX:
{
struct pdu_ipv6 *ipv6 = (void *) pdu;
ipv6->prefix = ip6_ntoh(ipv6->prefix);
ipv6->asn = ntohl(ipv6->asn);
break;
}
case ERROR:
{
/* Note that a error_code is converted using converting header->reserved */
struct pdu_error *err = (void *) pdu;
err->len_enc_pdu = ntohl(err->len_enc_pdu);
u32 *err_text_len = (u32 *)(err->rest + err->len_enc_pdu);
*err_text_len = htonl(*err_text_len);
break;
}
case ROUTER_KEY:
/* Router Key PDU is not supported yet */
case SERIAL_QUERY:
case RESET_QUERY:
/* Serial/Reset Query are sent only in direction router to cache.
* We don't care here. */
case CACHE_RESPONSE:
case CACHE_RESET:
/* Converted with pdu->reserved */
break;
}
}
/**
* rpki_convert_pdu_back_to_network_byte_order - convert host-byte order PDU back to network-byte order
* @out: allocated memory for writing a converted PDU of size @in->len
* @in: host-byte order PDU
*
* Assumed: |A == ntoh(ntoh(A))|
*/
static struct pdu_header *
rpki_pdu_back_to_network_byte_order(struct pdu_header *out, const struct pdu_header *in)
{
memcpy(out, in, in->len);
rpki_pdu_to_host_byte_order(out);
return out;
}
static void
rpki_log_packet(struct rpki_cache *cache, const struct pdu_header *pdu, const enum rpki_transmit_type action)
{
if (!(cache->p->p.debug & D_PACKETS))
return;
const char *str_type = str_pdu_type(pdu->type);
char detail[256];
#define SAVE(fn) \
do { \
if (fn < 0) \
{ \
bsnprintf(detail + sizeof(detail) - 16, 16, "... <too long>)"); \
goto detail_finished; \
} \
} while(0) \
switch (pdu->type)
{
case SERIAL_NOTIFY:
case SERIAL_QUERY:
SAVE(bsnprintf(detail, sizeof(detail), "(session id: %u, serial number: %u)", pdu->reserved, ((struct pdu_serial_notify *) pdu)->serial_num));
break;
case END_OF_DATA:
{
const struct pdu_end_of_data_v1 *eod = (void *) pdu;
if (eod->ver == RPKI_VERSION_1)
SAVE(bsnprintf(detail, sizeof(detail), "(session id: %u, serial number: %u, refresh: %us, retry: %us, expire: %us)", eod->session_id, eod->serial_num, eod->refresh_interval, eod->retry_interval, eod->expire_interval));
else
SAVE(bsnprintf(detail, sizeof(detail), "(session id: %u, serial number: %u)", eod->session_id, eod->serial_num));
break;
}
case CACHE_RESPONSE:
SAVE(bsnprintf(detail, sizeof(detail), "(session id: %u)", pdu->reserved));
break;
case IPV4_PREFIX:
{
const struct pdu_ipv4 *ipv4 = (void *) pdu;
SAVE(bsnprintf(detail, sizeof(detail), "(%I4/%u-%u AS%u)", ipv4->prefix, ipv4->prefix_len, ipv4->max_prefix_len, ipv4->asn));
break;
}
case IPV6_PREFIX:
{
const struct pdu_ipv6 *ipv6 = (void *) pdu;
SAVE(bsnprintf(detail, sizeof(detail), "(%I6/%u-%u AS%u)", ipv6->prefix, ipv6->prefix_len, ipv6->max_prefix_len, ipv6->asn));
break;
}
case ROUTER_KEY:
/* We don't support saving Router Key PDUs yet */
SAVE(bsnprintf(detail, sizeof(detail), "(ignored)"));
break;
case ERROR:
{
const struct pdu_error *err = (void *) pdu;
SAVE(bsnprintf(detail, sizeof(detail), "(%s", str_pdu_error_type[err->error_code]));
/* Optional description of error */
const u32 len_err_txt = *((u32 *) (err->rest + err->len_enc_pdu));
if (len_err_txt > 0)
{
size_t expected_len = err->len_enc_pdu + len_err_txt + 16;
if (expected_len == err->len)
{
char txt[len_err_txt + 1];
char *pdu_txt = (char *) err->rest + err->len_enc_pdu + 4;
bsnprintf(txt, sizeof(txt), "%s", pdu_txt); /* it's ensured that txt is ended with a null byte */
SAVE(bsnprintf(detail + strlen(detail), sizeof(detail) - strlen(detail), ": '%s'", txt));
}
else
{
SAVE(bsnprintf(detail + strlen(detail), sizeof(detail) - strlen(detail), ", malformed size"));
}
}
/* Optional encapsulated erroneous packet */
if (err->len_enc_pdu)
{
SAVE(bsnprintf(detail + strlen(detail), sizeof(detail) - strlen(detail), ", %s packet:", str_pdu_type(((struct pdu_header *) err->rest)->type)));
if (err->rest + err->len_enc_pdu <= (byte *)err + err->len)
{
for (const byte *c = err->rest; c != err->rest + err->len_enc_pdu; c++)
SAVE(bsnprintf(detail + strlen(detail), sizeof(detail) - strlen(detail), " %02X", *c));
}
}
SAVE(bsnprintf(detail + strlen(detail), sizeof(detail) - strlen(detail), ")"));
break;
}
default:
*detail = '\0';
}
#undef SAVE
detail_finished:
if (action == RPKI_RECV)
{
CACHE_TRACE(D_PACKETS, cache, "Received %s packet %s", str_type, detail);
}
else
{
CACHE_TRACE(D_PACKETS, cache, "Sending %s packet %s", str_type, detail);
}
#if defined(LOCAL_DEBUG) || defined(GLOBAL_DEBUG)
int seq = 0;
for(const byte *c = pdu; c != pdu + pdu->len; c++)
{
if ((seq % 4) == 0)
DBG("%2d: ", seq);
DBG(" 0x%02X %-3u", *c, *c);
if ((++seq % 4) == 0)
DBG("\n");
}
if ((seq % 4) != 0)
DBG("\n");
#endif
}
static int
rpki_send_pdu(struct rpki_cache *cache, const void *pdu, const uint len)
{
struct rpki_proto *p = cache->p;
sock *sk = cache->tr_sock->sk;
rpki_log_packet(cache, pdu, RPKI_SEND);
if (sk->tbuf != sk->tpos)
{
RPKI_WARN(p, "Old packet overwritten in TX buffer");
}
if (len > sk->tbsize)
{
RPKI_WARN(p, "%u bytes is too much for send", len);
ASSERT(0);
return RPKI_ERROR;
}
memcpy(sk->tbuf, pdu, len);
rpki_pdu_to_network_byte_order((void *) sk->tbuf);
if (!sk_send(sk, len))
{
DBG("Cannot send just the whole data. It will be sent using a call of tx_hook()");
}
return RPKI_SUCCESS;
}
/**
* rpki_check_receive_packet - make a basic validation of received RPKI PDU header
* @cache: cache connection instance
* @pdu: RPKI PDU in network byte order
*
* This function checks protocol version, PDU type, version and size. If all is all right then
* function returns |RPKI_SUCCESS| otherwise sends Error PDU and returns
* |RPKI_ERROR|.
*/
static int
rpki_check_receive_packet(struct rpki_cache *cache, const struct pdu_header *pdu)
{
u32 pdu_len = ntohl(pdu->len);
/*
* Minimal and maximal allowed PDU size is treated in rpki_rx_hook() function.
* @header.len corresponds to number of bytes of @pdu and
* it is in range from RPKI_PDU_HEADER_LEN to RPKI_PDU_MAX_LEN bytes.
*/
/* Do not handle error PDUs here, leave this task to rpki_handle_error_pdu() */
if (pdu->ver != cache->version && pdu->type != ERROR)
{
/* If this is the first PDU we have received */
if (cache->request_session_id)
{
if (pdu->type == SERIAL_NOTIFY)
{
/*
* The router MUST ignore any Serial Notify PDUs it might receive from
* the cache during this initial start-up period, regardless of the
* Protocol Version field in the Serial Notify PDU.
* (https://tools.ietf.org/html/draft-ietf-sidr-rpki-rtr-rfc6810-bis-07#section-7)
*/
}
else if (!cache->last_update &&
(pdu->ver <= RPKI_MAX_VERSION) &&
(pdu->ver < cache->version))
{
CACHE_TRACE(D_EVENTS, cache, "Downgrade session to %s from %u to %u version", rpki_get_cache_ident(cache), cache->version, pdu->ver);
cache->version = pdu->ver;
}
else
{
/* If this is not the first PDU we have received, something is wrong with
* the server implementation -> Error */
rpki_send_error_pdu(cache, UNSUPPORTED_PROTOCOL_VER, pdu_len, pdu, "PDU with unsupported Protocol version received");
return RPKI_ERROR;
}
}
}
if ((pdu->type >= PDU_TYPE_MAX) || (pdu->ver == RPKI_VERSION_0 && pdu->type == ROUTER_KEY))
{
rpki_send_error_pdu(cache, UNSUPPORTED_PDU_TYPE, pdu_len, pdu, "Unsupported PDU type %u received", pdu->type);
return RPKI_ERROR;
}
if (pdu_len < min_pdu_size[pdu->type])
{
rpki_send_error_pdu(cache, CORRUPT_DATA, pdu_len, pdu, "Received %s packet with %d bytes, but expected at least %d bytes", str_pdu_type(pdu->type), pdu_len, min_pdu_size[pdu->type]);
return RPKI_ERROR;
}
return RPKI_SUCCESS;
}
static int
rpki_handle_error_pdu(struct rpki_cache *cache, const struct pdu_error *pdu)
{
switch (pdu->error_code)
{
case CORRUPT_DATA:
case INTERNAL_ERROR:
case INVALID_REQUEST:
case UNSUPPORTED_PDU_TYPE:
rpki_cache_change_state(cache, RPKI_CS_ERROR_FATAL);
break;
case NO_DATA_AVAIL:
rpki_cache_change_state(cache, RPKI_CS_ERROR_NO_DATA_AVAIL);
break;
case UNSUPPORTED_PROTOCOL_VER:
CACHE_TRACE(D_PACKETS, cache, "Client uses unsupported protocol version");
if (pdu->ver <= RPKI_MAX_VERSION &&
pdu->ver < cache->version)
{
CACHE_TRACE(D_EVENTS, cache, "Downgrading from protocol version %d to version %d", cache->version, pdu->ver);
cache->version = pdu->ver;
rpki_cache_change_state(cache, RPKI_CS_FAST_RECONNECT);
}
else
{
CACHE_TRACE(D_PACKETS, cache, "Got UNSUPPORTED_PROTOCOL_VER error PDU with invalid values, " \
"current version: %d, PDU version: %d", cache->version, pdu->ver);
rpki_cache_change_state(cache, RPKI_CS_ERROR_FATAL);
}
break;
default:
CACHE_TRACE(D_PACKETS, cache, "Error unknown, server sent unsupported error code %u", pdu->error_code);
rpki_cache_change_state(cache, RPKI_CS_ERROR_FATAL);
break;
}
return RPKI_SUCCESS;
}
static void
rpki_handle_serial_notify_pdu(struct rpki_cache *cache, const struct pdu_serial_notify *pdu)
{
/* The router MUST ignore any Serial Notify PDUs it might receive from
* the cache during this initial start-up period, regardless of the
* Protocol Version field in the Serial Notify PDU.
* (https://tools.ietf.org/html/draft-ietf-sidr-rpki-rtr-rfc6810-bis-07#section-7)
*/
if (cache->request_session_id)
{
CACHE_TRACE(D_PACKETS, cache, "Ignore a Serial Notify packet during initial start-up period");
return;
}
/* XXX Serial number should be compared using method RFC 1982 (3.2) */
if (cache->serial_num != pdu->serial_num)
rpki_cache_change_state(cache, RPKI_CS_SYNC_START);
}
static int
rpki_handle_cache_response_pdu(struct rpki_cache *cache, const struct pdu_cache_response *pdu)
{
if (cache->request_session_id)
{
if (cache->last_update)
{
/*
* This isn't the first sync and we already received records. This point
* is after Reset Query and before importing new records from cache
* server. We need to load new ones and kick out missing ones. So start
* a refresh cycle.
*/
if (cache->p->roa4_channel)
rt_refresh_begin(cache->p->roa4_channel->table, cache->p->roa4_channel);
if (cache->p->roa6_channel)
rt_refresh_begin(cache->p->roa6_channel->table, cache->p->roa6_channel);
cache->p->refresh_channels = 1;
}
cache->session_id = pdu->session_id;
cache->request_session_id = 0;
}
else
{
if (cache->session_id != pdu->session_id)
{
byte tmp[pdu->len];
const struct pdu_header *hton_pdu = rpki_pdu_back_to_network_byte_order((void *) tmp, (const void *) pdu);
rpki_send_error_pdu(cache, CORRUPT_DATA, pdu->len, hton_pdu, "Wrong session_id %u in Cache Response PDU", pdu->session_id);
rpki_cache_change_state(cache, RPKI_CS_ERROR_FATAL);
return RPKI_ERROR;
}
}
rpki_cache_change_state(cache, RPKI_CS_SYNC_RUNNING);
return RPKI_SUCCESS;
}
/**
* rpki_prefix_pdu_2_net_addr - convert IPv4/IPv6 Prefix PDU into net_addr_union
* @pdu: host byte order IPv4/IPv6 Prefix PDU
* @n: allocated net_addr_union for save ROA
*
* This function reads ROA data from IPv4/IPv6 Prefix PDU and
* write them into net_addr_roa4 or net_addr_roa6 data structure.
*/
static net_addr_union *
rpki_prefix_pdu_2_net_addr(const struct pdu_header *pdu, net_addr_union *n)
{
/*
* Note that sizeof(net_addr_roa6) > sizeof(net_addr)
* and thence we must use net_addr_union and not only net_addr
*/
if (pdu->type == IPV4_PREFIX)
{
const struct pdu_ipv4 *ipv4 = (void *) pdu;
n->roa4.type = NET_ROA4;
n->roa4.length = sizeof(net_addr_roa4);
n->roa4.prefix = ipv4->prefix;
n->roa4.asn = ipv4->asn;
n->roa4.pxlen = ipv4->prefix_len;
n->roa4.max_pxlen = ipv4->max_prefix_len;
}
else
{
const struct pdu_ipv6 *ipv6 = (void *) pdu;
n->roa6.type = NET_ROA6;
n->roa6.length = sizeof(net_addr_roa6);
n->roa6.prefix = ipv6->prefix;
n->roa6.asn = ipv6->asn;
n->roa6.pxlen = ipv6->prefix_len;
n->roa6.max_pxlen = ipv6->max_prefix_len;
}
return n;
}
static int
rpki_handle_prefix_pdu(struct rpki_cache *cache, const struct pdu_header *pdu)
{
const struct rpki_config *cf = (void *) cache->p->p.cf;
const enum pdu_type type = pdu->type;
ASSERT(type == IPV4_PREFIX || type == IPV6_PREFIX);
net_addr_union addr = {};
rpki_prefix_pdu_2_net_addr(pdu, &addr);
if (type == IPV4_PREFIX)
{
if ((addr.roa4.pxlen > addr.roa4.max_pxlen) ||
(addr.roa4.max_pxlen > IP4_MAX_PREFIX_LENGTH))
{
RPKI_WARN(cache->p, "Received corrupt packet from RPKI cache server: invalid pxlen or max_pxlen");
byte tmp[pdu->len];
const struct pdu_header *hton_pdu = rpki_pdu_back_to_network_byte_order((void *) tmp, (const void *) pdu);
rpki_send_error_pdu(cache, CORRUPT_DATA, pdu->len, hton_pdu, "Corrupted PDU: invalid pxlen or max_pxlen");
rpki_cache_change_state(cache, RPKI_CS_ERROR_FATAL);
return RPKI_ERROR;
}
}
else
{
if ((addr.roa6.pxlen > addr.roa6.max_pxlen) ||
(addr.roa6.max_pxlen > IP6_MAX_PREFIX_LENGTH))
{
RPKI_WARN(cache->p, "Received corrupt packet from RPKI cache server: invalid pxlen or max_pxlen");
byte tmp[pdu->len];
const struct pdu_header *hton_pdu = rpki_pdu_back_to_network_byte_order((void *) tmp, (const void *) pdu);
rpki_send_error_pdu(cache, CORRUPT_DATA, pdu->len, hton_pdu, "Corrupted PDU: invalid pxlen or max_pxlen");
rpki_cache_change_state(cache, RPKI_CS_ERROR_FATAL);
return RPKI_ERROR;
}
}
if (cf->ignore_max_length)
{
if (type == IPV4_PREFIX)
addr.roa4.max_pxlen = IP4_MAX_PREFIX_LENGTH;
else
addr.roa6.max_pxlen = IP6_MAX_PREFIX_LENGTH;
}
struct channel *channel = NULL;
if (type == IPV4_PREFIX)
channel = cache->p->roa4_channel;
if (type == IPV6_PREFIX)
channel = cache->p->roa6_channel;
if (!channel)
{
CACHE_TRACE(D_ROUTES, cache, "Skip %N, missing %s channel", &addr, (type == IPV4_PREFIX ? "roa4" : "roa6"), addr);
return RPKI_ERROR;
}
cache->last_rx_prefix = current_time();
/* A place for 'flags' is same for both data structures pdu_ipv4 or pdu_ipv6 */
struct pdu_ipv4 *pfx = (void *) pdu;
if (pfx->flags & RPKI_ADD_FLAG)
rpki_table_add_roa(cache, channel, &addr);
else
rpki_table_remove_roa(cache, channel, &addr);
return RPKI_SUCCESS;
}
static uint
rpki_check_interval(struct rpki_cache *cache, const char *(check_fn)(uint), uint interval)
{
if (check_fn(interval))
{
RPKI_WARN(cache->p, "%s, received %u seconds", check_fn(interval), interval);
return 0;
}
return 1;
}
static void
rpki_handle_end_of_data_pdu(struct rpki_cache *cache, const struct pdu_end_of_data_v1 *pdu)
{
const struct rpki_config *cf = (void *) cache->p->p.cf;
if (pdu->session_id != cache->session_id)
{
byte tmp[pdu->len];
const struct pdu_header *hton_pdu = rpki_pdu_back_to_network_byte_order((void *) tmp, (const void *) pdu);
rpki_send_error_pdu(cache, CORRUPT_DATA, pdu->len, hton_pdu, "Received Session ID %u, but expected %u", pdu->session_id, cache->session_id);
rpki_cache_change_state(cache, RPKI_CS_ERROR_FATAL);
return;
}
if (pdu->ver == RPKI_VERSION_1)
{
if (!cf->keep_refresh_interval && rpki_check_interval(cache, rpki_check_refresh_interval, pdu->refresh_interval))
cache->refresh_interval = pdu->refresh_interval;
if (!cf->keep_retry_interval && rpki_check_interval(cache, rpki_check_retry_interval, pdu->retry_interval))
cache->retry_interval = pdu->retry_interval;
if (!cf->keep_expire_interval && rpki_check_interval(cache, rpki_check_expire_interval, pdu->expire_interval))
cache->expire_interval = pdu->expire_interval;
CACHE_TRACE(D_EVENTS, cache, "New interval values: "
"refresh: %s%us, "
"retry: %s%us, "
"expire: %s%us",
(cf->keep_refresh_interval ? "keeps " : ""), cache->refresh_interval,
(cf->keep_retry_interval ? "keeps " : ""), cache->retry_interval,
(cf->keep_expire_interval ? "keeps " : ""), cache->expire_interval);
}
if (cache->p->refresh_channels)
{
cache->p->refresh_channels = 0;
if (cache->p->roa4_channel)
rt_refresh_end(cache->p->roa4_channel->table, cache->p->roa4_channel);
if (cache->p->roa6_channel)
rt_refresh_end(cache->p->roa6_channel->table, cache->p->roa6_channel);
}
cache->last_update = current_time();
cache->serial_num = pdu->serial_num;
rpki_cache_change_state(cache, RPKI_CS_ESTABLISHED);
}
/**
* rpki_rx_packet - process a received RPKI PDU
* @cache: RPKI connection instance
* @pdu: a RPKI PDU in network byte order
*/
static void
rpki_rx_packet(struct rpki_cache *cache, struct pdu_header *pdu)
{
struct rpki_proto *p = cache->p;
if (rpki_check_receive_packet(cache, pdu) == RPKI_ERROR)
{
rpki_cache_change_state(cache, RPKI_CS_ERROR_FATAL);
return;
}
rpki_pdu_to_host_byte_order(pdu);
rpki_log_packet(cache, pdu, RPKI_RECV);
switch (pdu->type)
{
case RESET_QUERY:
case SERIAL_QUERY:
RPKI_WARN(p, "Received a %s packet that is destined for cache server", str_pdu_type(pdu->type));
break;
case SERIAL_NOTIFY:
/* This is a signal to synchronize with the cache server just now */
rpki_handle_serial_notify_pdu(cache, (void *) pdu);
break;
case CACHE_RESPONSE:
rpki_handle_cache_response_pdu(cache, (void *) pdu);
break;
case IPV4_PREFIX:
case IPV6_PREFIX:
rpki_handle_prefix_pdu(cache, pdu);
break;
case END_OF_DATA:
rpki_handle_end_of_data_pdu(cache, (void *) pdu);
break;
case CACHE_RESET:
/* Cache cannot provide an incremental update. */
rpki_cache_change_state(cache, RPKI_CS_NO_INCR_UPDATE_AVAIL);
break;
case ERROR:
rpki_handle_error_pdu(cache, (void *) pdu);
break;
case ROUTER_KEY:
/* TODO: Implement Router Key PDU handling */
break;
default:
CACHE_TRACE(D_PACKETS, cache, "Received unsupported type (%u)", pdu->type);
};
}
int
rpki_rx_hook(struct birdsock *sk, uint size)
{
struct rpki_cache *cache = sk->data;
struct rpki_proto *p = cache->p;
byte *pkt_start = sk->rbuf;
byte *end = pkt_start + size;
DBG("rx hook got %u bytes \n", size);
while (end >= pkt_start + RPKI_PDU_HEADER_LEN)
{
struct pdu_header *pdu = (void *) pkt_start;
u32 pdu_size = ntohl(pdu->len);
if (pdu_size < RPKI_PDU_HEADER_LEN || pdu_size > RPKI_PDU_MAX_LEN)
{
RPKI_WARN(p, "Received invalid packet length %u, purge the whole receiving buffer", pdu_size);
return 1; /* Purge recv buffer */
}
if (end < pkt_start + pdu_size)
break;
rpki_rx_packet(cache, pdu);
/* It is possible that bird socket was freed/closed */
if (p->p.proto_state == PS_DOWN || sk != cache->tr_sock->sk)
return 0;
pkt_start += pdu_size;
}
if (pkt_start != sk->rbuf)
{
CACHE_DBG(cache, "Move %u bytes of a memory at the start of buffer", end - pkt_start);
memmove(sk->rbuf, pkt_start, end - pkt_start);
sk->rpos = sk->rbuf + (end - pkt_start);
}
return 0; /* Not purge sk->rbuf */
}
void
rpki_err_hook(struct birdsock *sk, int error_num)
{
struct rpki_cache *cache = sk->data;
if (error_num)
{
/* sk->err may contains a SSH error description */
if (sk->err)
CACHE_TRACE(D_EVENTS, cache, "Lost connection: %s", sk->err);
else
CACHE_TRACE(D_EVENTS, cache, "Lost connection: %M", error_num);
}
else
{
CACHE_TRACE(D_EVENTS, cache, "The other side closed a connection");
}
rpki_cache_change_state(cache, RPKI_CS_ERROR_TRANSPORT);
}
static int
rpki_fire_tx(struct rpki_cache *cache)
{
sock *sk = cache->tr_sock->sk;
uint bytes_to_send = sk->tpos - sk->tbuf;
DBG("Sending %u bytes", bytes_to_send);
return sk_send(sk, bytes_to_send);
}
void
rpki_tx_hook(sock *sk)
{
struct rpki_cache *cache = sk->data;
while (rpki_fire_tx(cache) > 0)
;
}
void
rpki_connected_hook(sock *sk)
{
struct rpki_cache *cache = sk->data;
CACHE_TRACE(D_EVENTS, cache, "Connected");
proto_notify_state(&cache->p->p, PS_UP);
sk->rx_hook = rpki_rx_hook;
sk->tx_hook = rpki_tx_hook;
rpki_cache_change_state(cache, RPKI_CS_SYNC_START);
}
/**
* rpki_send_error_pdu - send RPKI Error PDU
* @cache: RPKI connection instance
* @error_code: PDU Error type
* @err_pdu_len: length of @erroneous_pdu
* @erroneous_pdu: optional network byte-order PDU that invokes Error by us or NULL
* @fmt: optional description text of error or NULL
* @args: optional arguments for @fmt
*
* This function prepares Error PDU and sends it to a cache server.
*/
static int
rpki_send_error_pdu(struct rpki_cache *cache, const enum pdu_error_type error_code, const u32 err_pdu_len, const struct pdu_header *erroneous_pdu, const char *fmt, ...)
{
va_list args;
char msg[128];
/* Size including the terminating null byte ('\0') */
int msg_len = 0;
/* Don't send errors for erroneous error PDUs */
if (err_pdu_len >= 2)
{
if (erroneous_pdu->type == ERROR)
return RPKI_SUCCESS;
}
if (fmt)
{
va_start(args, fmt);
msg_len = bvsnprintf(msg, sizeof(msg), fmt, args) + 1;
va_end(args);
}
u32 pdu_size = 16 + err_pdu_len + msg_len;
byte pdu[pdu_size];
memset(pdu, 0, sizeof(pdu));
struct pdu_error *e = (void *) pdu;
e->ver = cache->version;
e->type = ERROR;
e->error_code = error_code;
e->len = pdu_size;
e->len_enc_pdu = err_pdu_len;
if (err_pdu_len > 0)
memcpy(e->rest, erroneous_pdu, err_pdu_len);
*((u32 *)(e->rest + err_pdu_len)) = msg_len;
if (msg_len > 0)
memcpy(e->rest + err_pdu_len + 4, msg, msg_len);
return rpki_send_pdu(cache, pdu, pdu_size);
}
int
rpki_send_serial_query(struct rpki_cache *cache)
{
struct pdu_serial_query pdu = {
.ver = cache->version,
.type = SERIAL_QUERY,
.session_id = cache->session_id,
.len = sizeof(pdu),
.serial_num = cache->serial_num
};
if (rpki_send_pdu(cache, &pdu, sizeof(pdu)) != RPKI_SUCCESS)
{
rpki_cache_change_state(cache, RPKI_CS_ERROR_TRANSPORT);
return RPKI_ERROR;
}
return RPKI_SUCCESS;
}
int
rpki_send_reset_query(struct rpki_cache *cache)
{
struct pdu_reset_query pdu = {
.ver = cache->version,
.type = RESET_QUERY,
.len = sizeof(pdu),
};
if (rpki_send_pdu(cache, &pdu, sizeof(pdu)) != RPKI_SUCCESS)
{
rpki_cache_change_state(cache, RPKI_CS_ERROR_TRANSPORT);
return RPKI_ERROR;
}
return RPKI_SUCCESS;
}
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