2 * EIGRP Sending and Receiving EIGRP Hello Packets.
3 * Copyright (C) 2013-2016
15 * This file is part of GNU Zebra.
17 * GNU Zebra is free software; you can redistribute it and/or modify it
18 * under the terms of the GNU General Public License as published by the
19 * Free Software Foundation; either version 2, or (at your option) any
22 * GNU Zebra is distributed in the hope that it will be useful, but
23 * WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25 * General Public License for more details.
27 * You should have received a copy of the GNU General Public License along
28 * with this program; see the file COPYING; if not, write to the Free Software
29 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
40 #include "sockunion.h"
48 #include "eigrpd/eigrp_structs.h"
49 #include "eigrpd/eigrpd.h"
50 #include "eigrpd/eigrp_interface.h"
51 #include "eigrpd/eigrp_neighbor.h"
52 #include "eigrpd/eigrp_packet.h"
53 #include "eigrpd/eigrp_zebra.h"
54 #include "eigrpd/eigrp_vty.h"
55 #include "eigrpd/eigrp_dump.h"
56 #include "eigrpd/eigrp_macros.h"
57 #include "eigrpd/eigrp_errors.h"
59 /* Packet Type String. */
60 static const struct message eigrp_general_tlv_type_str
[] = {
61 {EIGRP_TLV_PARAMETER
, "PARAMETER"},
62 {EIGRP_TLV_AUTH
, "AUTH"},
63 {EIGRP_TLV_SEQ
, "SEQ"},
64 {EIGRP_TLV_SW_VERSION
, "SW_VERSION"},
65 {EIGRP_TLV_NEXT_MCAST_SEQ
, "NEXT_MCAST_SEQ"},
66 {EIGRP_TLV_PEER_TERMINATION
, "PEER_TERMINATION"},
67 {EIGRP_TLV_PEER_MTRLIST
, "PEER_MTRLIST"},
68 {EIGRP_TLV_PEER_TIDLIST
, "PEER_TIDLIST"},
73 * @fn eigrp_hello_timer
75 * @param[in] thread current execution thread timer is associated with
77 * @return int always returns 0
80 * Called once per "hello" time interval, default 5 seconds
81 * Sends hello packet via multicast for all interfaces eigrp
84 int eigrp_hello_timer(struct thread
*thread
)
86 struct eigrp_interface
*ei
;
88 ei
= THREAD_ARG(thread
);
91 if (IS_DEBUG_EIGRP(0, TIMERS
))
92 zlog_debug("Start Hello Timer (%s) Expire [%u]", IF_NAME(ei
),
95 /* Sending hello packet. */
96 eigrp_hello_send(ei
, EIGRP_HELLO_NORMAL
, NULL
);
98 /* Hello timer set. */
100 thread_add_timer(master
, eigrp_hello_timer
, ei
, ei
->params
.v_hello
,
107 * @fn eigrp_hello_parameter_decode
109 * @param[in] nbr neighbor the ACK should be sent to
110 * @param[in] param pointer packet TLV is stored to
112 * @return uint16_t number of bytes added to packet stream
115 * Encode Parameter TLV, used to convey metric weights and the hold time.
118 * Note the addition of K6 for the new extended metrics, and does not apply to
119 * older TLV packet formats.
121 static struct eigrp_neighbor
*
122 eigrp_hello_parameter_decode(struct eigrp_neighbor
*nbr
,
123 struct eigrp_tlv_hdr_type
*tlv
)
125 struct eigrp
*eigrp
= nbr
->ei
->eigrp
;
126 struct TLV_Parameter_Type
*param
= (struct TLV_Parameter_Type
*)tlv
;
128 /* copy over the values passed in by the neighbor */
135 nbr
->v_holddown
= ntohs(param
->hold_time
);
138 * Check K1-K5 have the correct values to be able to become neighbors
139 * K6 does not have to match
141 if ((eigrp
->k_values
[0] == nbr
->K1
) && (eigrp
->k_values
[1] == nbr
->K2
)
142 && (eigrp
->k_values
[2] == nbr
->K3
)
143 && (eigrp
->k_values
[3] == nbr
->K4
)
144 && (eigrp
->k_values
[4] == nbr
->K5
)) {
146 if (eigrp_nbr_state_get(nbr
) == EIGRP_NEIGHBOR_DOWN
) {
148 "Neighbor %pI4 (%s) is pending: new adjacency",
150 ifindex2ifname(nbr
->ei
->ifp
->ifindex
,
153 /* Expedited hello sent */
154 eigrp_hello_send(nbr
->ei
, EIGRP_HELLO_NORMAL
, NULL
);
156 // if(ntohl(nbr->ei->address->u.prefix4.s_addr) >
157 // ntohl(nbr->src.s_addr))
158 eigrp_update_send_init(nbr
);
160 eigrp_nbr_state_set(nbr
, EIGRP_NEIGHBOR_PENDING
);
163 if (eigrp_nbr_state_get(nbr
) != EIGRP_NEIGHBOR_DOWN
) {
164 if ((param
->K1
& param
->K2
& param
->K3
& param
->K4
168 "Neighbor %pI4 (%s) is down: Interface PEER-TERMINATION received",
170 ifindex2ifname(nbr
->ei
->ifp
->ifindex
,
172 eigrp_nbr_delete(nbr
);
176 "Neighbor %pI4 (%s) going down: Kvalue mismatch",
178 ifindex2ifname(nbr
->ei
->ifp
->ifindex
,
180 eigrp_nbr_state_set(nbr
, EIGRP_NEIGHBOR_DOWN
);
189 eigrp_hello_authentication_decode(struct stream
*s
,
190 struct eigrp_tlv_hdr_type
*tlv_header
,
191 struct eigrp_neighbor
*nbr
)
193 struct TLV_MD5_Authentication_Type
*md5
;
195 md5
= (struct TLV_MD5_Authentication_Type
*)tlv_header
;
197 if (md5
->auth_type
== EIGRP_AUTH_TYPE_MD5
)
198 return eigrp_check_md5_digest(s
, md5
, nbr
,
199 EIGRP_AUTH_BASIC_HELLO_FLAG
);
200 else if (md5
->auth_type
== EIGRP_AUTH_TYPE_SHA256
)
201 return eigrp_check_sha256_digest(
202 s
, (struct TLV_SHA256_Authentication_Type
*)tlv_header
,
203 nbr
, EIGRP_AUTH_BASIC_HELLO_FLAG
);
209 * @fn eigrp_sw_version_decode
211 * @param[in] nbr neighbor the ACK shoudl be sent to
212 * @param[in] param pointer to TLV software version information
217 * Read the software version in the specified location.
218 * This consists of two bytes of OS version, and two bytes of EIGRP
221 static void eigrp_sw_version_decode(struct eigrp_neighbor
*nbr
,
222 struct eigrp_tlv_hdr_type
*tlv
)
224 struct TLV_Software_Type
*version
= (struct TLV_Software_Type
*)tlv
;
226 nbr
->os_rel_major
= version
->vender_major
;
227 nbr
->os_rel_minor
= version
->vender_minor
;
228 nbr
->tlv_rel_major
= version
->eigrp_major
;
229 nbr
->tlv_rel_minor
= version
->eigrp_minor
;
234 * @fn eigrp_peer_termination_decode
236 * @param[in] nbr neighbor the ACK shoudl be sent to
237 * @param[in] tlv pointer to TLV software version information
242 * Read the address in the TLV and match to out address. If
243 * a match is found, move the sending neighbor to the down state. If
244 * out address is not in the TLV, then ignore the peer termination
246 static void eigrp_peer_termination_decode(struct eigrp_neighbor
*nbr
,
247 struct eigrp_tlv_hdr_type
*tlv
)
249 struct eigrp
*eigrp
= nbr
->ei
->eigrp
;
250 struct TLV_Peer_Termination_type
*param
=
251 (struct TLV_Peer_Termination_type
*)tlv
;
253 uint32_t my_ip
= nbr
->ei
->address
.u
.prefix4
.s_addr
;
254 uint32_t received_ip
= param
->neighbor_ip
;
256 if (my_ip
== received_ip
) {
258 "Neighbor %pI4 (%s) is down: Peer Termination received",
260 ifindex2ifname(nbr
->ei
->ifp
->ifindex
, eigrp
->vrf_id
));
261 /* set neighbor to DOWN */
262 nbr
->state
= EIGRP_NEIGHBOR_DOWN
;
263 /* delete neighbor */
264 eigrp_nbr_delete(nbr
);
269 * @fn eigrp_peer_termination_encode
271 * @param[in,out] s packet stream TLV is stored to
272 * @param[in] nbr_addr pointer to neighbor address for Peer
275 * @return uint16_t number of bytes added to packet stream
278 * Function used to encode Peer Termination TLV to Hello packet.
280 static uint16_t eigrp_peer_termination_encode(struct stream
*s
,
281 struct in_addr
*nbr_addr
)
283 uint16_t length
= EIGRP_TLV_PEER_TERMINATION_LEN
;
285 /* fill in type and length */
286 stream_putw(s
, EIGRP_TLV_PEER_TERMINATION
);
287 stream_putw(s
, length
);
289 /* fill in unknown field 0x04 */
290 stream_putc(s
, 0x04);
292 /* finally neighbor IP address */
293 stream_put_ipv4(s
, nbr_addr
->s_addr
);
299 * @fn eigrp_hello_receive
301 * @param[in] eigrp eigrp routing process
302 * @param[in] iph pointer to ip header
303 * @param[in] eigrph pointer to eigrp header
304 * @param[in] s input ip stream
305 * @param[in] ei eigrp interface packet arrived on
306 * @param[in] size size of eigrp packet
311 * This is the main worker function for processing hello packets. It
312 * will validate the peer associated with the src ip address of the ip
313 * header, and then decode each of the general TLVs which the packet
317 * Not all TLVs are current decoder. This is a work in progress..
319 void eigrp_hello_receive(struct eigrp
*eigrp
, struct ip
*iph
,
320 struct eigrp_header
*eigrph
, struct stream
*s
,
321 struct eigrp_interface
*ei
, int size
)
323 struct eigrp_tlv_hdr_type
*tlv_header
;
324 struct eigrp_neighbor
*nbr
;
328 /* get neighbor struct */
329 nbr
= eigrp_nbr_get(ei
, eigrph
, iph
);
331 /* neighbor must be valid, eigrp_nbr_get creates if none existed */
334 if (IS_DEBUG_EIGRP_PACKET(eigrph
->opcode
- 1, RECV
))
335 zlog_debug("Processing Hello size[%u] int(%s) nbr(%pI4)", size
,
336 ifindex2ifname(nbr
->ei
->ifp
->ifindex
, eigrp
->vrf_id
),
339 size
-= EIGRP_HEADER_LEN
;
343 tlv_header
= (struct eigrp_tlv_hdr_type
*)eigrph
->tlv
;
346 type
= ntohs(tlv_header
->type
);
347 length
= ntohs(tlv_header
->length
);
349 if ((length
> 0) && (length
<= size
)) {
350 if (IS_DEBUG_EIGRP_PACKET(0, RECV
))
353 lookup_msg(eigrp_general_tlv_type_str
,
356 // determine what General TLV is being processed
358 case EIGRP_TLV_PARAMETER
:
359 nbr
= eigrp_hello_parameter_decode(nbr
,
364 case EIGRP_TLV_AUTH
: {
365 if (eigrp_hello_authentication_decode(
375 case EIGRP_TLV_SW_VERSION
:
376 eigrp_sw_version_decode(nbr
, tlv_header
);
378 case EIGRP_TLV_NEXT_MCAST_SEQ
:
380 case EIGRP_TLV_PEER_TERMINATION
:
381 eigrp_peer_termination_decode(nbr
, tlv_header
);
384 case EIGRP_TLV_PEER_MTRLIST
:
385 case EIGRP_TLV_PEER_TIDLIST
:
392 tlv_header
= (struct eigrp_tlv_hdr_type
*)(((char *)tlv_header
)
399 /*If received packet is hello with Parameter TLV*/
400 if (ntohl(eigrph
->ack
) == 0) {
401 /* increment statistics. */
404 eigrp_nbr_state_update(nbr
);
407 if (IS_DEBUG_EIGRP_PACKET(0, RECV
))
408 zlog_debug("Hello Packet received from %pI4", &nbr
->src
);
414 void eigrp_sw_version_initialize(void)
416 char ver_string
[] = VERSION
;
417 char *dash
= strstr(ver_string
, "-");
423 ret
= sscanf(ver_string
, "%" SCNu32
".%" SCNu32
, &FRR_MAJOR
,
426 flog_err(EC_EIGRP_PACKET
,
427 "Did not Properly parse %s, please fix VERSION string",
432 * @fn eigrp_sw_version_encode
434 * @param[in,out] s packet stream TLV is stored to
436 * @return uint16_t number of bytes added to packet stream
439 * Store the software version in the specified location.
440 * This consists of two bytes of OS version, and two bytes of EIGRP
443 static uint16_t eigrp_sw_version_encode(struct stream
*s
)
445 uint16_t length
= EIGRP_TLV_SW_VERSION_LEN
;
447 // setup the tlv fields
448 stream_putw(s
, EIGRP_TLV_SW_VERSION
);
449 stream_putw(s
, length
);
451 stream_putc(s
, FRR_MAJOR
); //!< major os version
452 stream_putc(s
, FRR_MINOR
); //!< minor os version
454 /* and the core eigrp version */
455 stream_putc(s
, EIGRP_MAJOR_VERSION
);
456 stream_putc(s
, EIGRP_MINOR_VERSION
);
462 * @fn eigrp_tidlist_encode
464 * @param[in,out] s packet stream TLV is stored to
469 * If doing mutli-topology, then store the supported TID list.
470 * This is currently a place holder function
472 static uint16_t eigrp_tidlist_encode(struct stream
*s
)
474 // uint16_t length = EIGRP_TLV_SW_VERSION_LEN;
479 * @fn eigrp_sequence_encode
481 * @param[in,out] s packet stream TLV is stored to
483 * @return uint16_t number of bytes added to packet stream
486 * Part of conditional receive process
489 static uint16_t eigrp_sequence_encode(struct eigrp
*eigrp
, struct stream
*s
)
491 uint16_t length
= EIGRP_TLV_SEQ_BASE_LEN
;
492 struct eigrp_interface
*ei
;
493 struct listnode
*node
, *node2
, *nnode2
;
494 struct eigrp_neighbor
*nbr
;
495 size_t backup_end
, size_end
;
498 // add in the parameters TLV
499 backup_end
= stream_get_endp(s
);
500 stream_putw(s
, EIGRP_TLV_SEQ
);
502 stream_putw(s
, 0x0000);
503 stream_putc(s
, IPV4_MAX_BYTELEN
);
506 for (ALL_LIST_ELEMENTS_RO(eigrp
->eiflist
, node
, ei
)) {
507 for (ALL_LIST_ELEMENTS(ei
->nbrs
, node2
, nnode2
, nbr
)) {
508 if (nbr
->multicast_queue
->count
> 0) {
509 length
+= (uint16_t)stream_put_ipv4(
517 stream_set_endp(s
, backup_end
);
521 backup_end
= stream_get_endp(s
);
522 stream_set_endp(s
, size_end
);
523 stream_putw(s
, length
);
524 stream_set_endp(s
, backup_end
);
530 * @fn eigrp_sequence_encode
532 * @param[in,out] s packet stream TLV is stored to
534 * @return uint16_t number of bytes added to packet stream
537 * Part of conditional receive process
540 static uint16_t eigrp_next_sequence_encode(struct eigrp
*eigrp
,
543 uint16_t length
= EIGRP_NEXT_SEQUENCE_TLV_SIZE
;
545 // add in the parameters TLV
546 stream_putw(s
, EIGRP_TLV_NEXT_MCAST_SEQ
);
547 stream_putw(s
, EIGRP_NEXT_SEQUENCE_TLV_SIZE
);
548 stream_putl(s
, eigrp
->sequence_number
+ 1);
554 * @fn eigrp_hello_parameter_encode
556 * @param[in] ei pointer to interface hello packet came in on
557 * @param[in,out] s packet stream TLV is stored to
559 * @return uint16_t number of bytes added to packet stream
562 * Encode Parameter TLV, used to convey metric weights and the hold time.
565 * Note the addition of K6 for the new extended metrics, and does not apply to
566 * older TLV packet formats.
568 static uint16_t eigrp_hello_parameter_encode(struct eigrp_interface
*ei
,
569 struct stream
*s
, uint8_t flags
)
571 // add in the parameters TLV
572 stream_putw(s
, EIGRP_TLV_PARAMETER
);
573 stream_putw(s
, EIGRP_TLV_PARAMETER_LEN
);
575 // if graceful shutdown is needed to be announced, send all 255 in K
577 if (flags
& EIGRP_HELLO_GRACEFUL_SHUTDOWN
) {
578 stream_putc(s
, 0xff); /* K1 */
579 stream_putc(s
, 0xff); /* K2 */
580 stream_putc(s
, 0xff); /* K3 */
581 stream_putc(s
, 0xff); /* K4 */
582 stream_putc(s
, 0xff); /* K5 */
583 stream_putc(s
, 0xff); /* K6 */
584 } else // set k values
586 stream_putc(s
, ei
->eigrp
->k_values
[0]); /* K1 */
587 stream_putc(s
, ei
->eigrp
->k_values
[1]); /* K2 */
588 stream_putc(s
, ei
->eigrp
->k_values
[2]); /* K3 */
589 stream_putc(s
, ei
->eigrp
->k_values
[3]); /* K4 */
590 stream_putc(s
, ei
->eigrp
->k_values
[4]); /* K5 */
591 stream_putc(s
, ei
->eigrp
->k_values
[5]); /* K6 */
594 // and set hold time value..
595 stream_putw(s
, ei
->params
.v_wait
);
597 return EIGRP_TLV_PARAMETER_LEN
;
601 * @fn eigrp_hello_encode
603 * @param[in] ei pointer to interface hello packet came in on
604 * @param[in] s packet stream TLV is stored to
605 * @param[in] ack if non-zero, neigbors sequence packet to ack
606 * @param[in] flags type of hello packet
607 * @param[in] nbr_addr pointer to neighbor address for Peer
610 * @return eigrp_packet pointer initialize hello packet
613 * Allocate an EIGRP hello packet, and add in the the approperate TLVs
616 static struct eigrp_packet
*eigrp_hello_encode(struct eigrp_interface
*ei
,
617 in_addr_t addr
, uint32_t ack
,
619 struct in_addr
*nbr_addr
)
621 struct eigrp_packet
*ep
;
622 uint16_t length
= EIGRP_HEADER_LEN
;
624 // allocate a new packet to be sent
625 ep
= eigrp_packet_new(EIGRP_PACKET_MTU(ei
->ifp
->mtu
), NULL
);
628 // encode common header feilds
629 eigrp_packet_header_init(EIGRP_OPC_HELLO
, ei
->eigrp
, ep
->s
, 0,
632 // encode Authentication TLV
633 if ((ei
->params
.auth_type
== EIGRP_AUTH_TYPE_MD5
)
634 && (ei
->params
.auth_keychain
!= NULL
)) {
635 length
+= eigrp_add_authTLV_MD5_to_stream(ep
->s
, ei
);
636 } else if ((ei
->params
.auth_type
== EIGRP_AUTH_TYPE_SHA256
)
637 && (ei
->params
.auth_keychain
!= NULL
)) {
638 length
+= eigrp_add_authTLV_SHA256_to_stream(ep
->s
, ei
);
641 /* encode appropriate parameters to Hello packet */
642 if (flags
& EIGRP_HELLO_GRACEFUL_SHUTDOWN
)
643 length
+= eigrp_hello_parameter_encode(
644 ei
, ep
->s
, EIGRP_HELLO_GRACEFUL_SHUTDOWN
);
646 length
+= eigrp_hello_parameter_encode(
647 ei
, ep
->s
, EIGRP_HELLO_NORMAL
);
649 // figure out the version of code we're running
650 length
+= eigrp_sw_version_encode(ep
->s
);
652 if (flags
& EIGRP_HELLO_ADD_SEQUENCE
) {
653 length
+= eigrp_sequence_encode(ei
->eigrp
, ep
->s
);
654 length
+= eigrp_next_sequence_encode(ei
->eigrp
, ep
->s
);
657 // add in the TID list if doing multi-topology
658 length
+= eigrp_tidlist_encode(ep
->s
);
660 /* encode Peer Termination TLV if needed */
661 if (flags
& EIGRP_HELLO_GRACEFUL_SHUTDOWN_NBR
)
663 eigrp_peer_termination_encode(ep
->s
, nbr_addr
);
668 // set soruce address for the hello packet
669 ep
->dst
.s_addr
= addr
;
671 if ((ei
->params
.auth_type
== EIGRP_AUTH_TYPE_MD5
)
672 && (ei
->params
.auth_keychain
!= NULL
)) {
673 eigrp_make_md5_digest(ei
, ep
->s
,
674 EIGRP_AUTH_BASIC_HELLO_FLAG
);
675 } else if ((ei
->params
.auth_type
== EIGRP_AUTH_TYPE_SHA256
)
676 && (ei
->params
.auth_keychain
!= NULL
)) {
677 eigrp_make_sha256_digest(ei
, ep
->s
,
678 EIGRP_AUTH_BASIC_HELLO_FLAG
);
682 eigrp_packet_checksum(ei
, ep
->s
, length
);
689 * @fn eigrp_hello_send
691 * @param[in] nbr neighbor the ACK should be sent to
696 * Send (unicast) a hello packet with the destination address
697 * associated with the neighbor. The eigrp header ACK feild will be
698 * updated to the neighbor's sequence number to acknolodge any
699 * outstanding packets
701 void eigrp_hello_send_ack(struct eigrp_neighbor
*nbr
)
703 struct eigrp_packet
*ep
;
705 /* if packet succesfully created, add it to the interface queue */
706 ep
= eigrp_hello_encode(nbr
->ei
, nbr
->src
.s_addr
,
707 nbr
->recv_sequence_number
, EIGRP_HELLO_NORMAL
,
711 if (IS_DEBUG_EIGRP_PACKET(0, SEND
))
712 zlog_debug("Queueing [Hello] Ack Seq [%u] nbr [%pI4]",
713 nbr
->recv_sequence_number
, &nbr
->src
);
715 /* Add packet to the top of the interface output queue*/
716 eigrp_fifo_push(nbr
->ei
->obuf
, ep
);
718 /* Hook thread to write packet. */
719 if (nbr
->ei
->on_write_q
== 0) {
720 listnode_add(nbr
->ei
->eigrp
->oi_write_q
, nbr
->ei
);
721 nbr
->ei
->on_write_q
= 1;
723 thread_add_write(master
, eigrp_write
, nbr
->ei
->eigrp
,
724 nbr
->ei
->eigrp
->fd
, &nbr
->ei
->eigrp
->t_write
);
729 * @fn eigrp_hello_send
731 * @param[in] ei pointer to interface hello should be sent
732 * @param[in] flags type of hello packet
733 * @param[in] nbr_addr pointer to neighbor address for Peer
739 * Build and enqueue a generic (multicast) periodic hello packet for
740 * sending. If no packets are currently queues, the packet will be
743 void eigrp_hello_send(struct eigrp_interface
*ei
, uint8_t flags
,
744 struct in_addr
*nbr_addr
)
746 struct eigrp_packet
*ep
= NULL
;
748 if (IS_DEBUG_EIGRP_PACKET(0, SEND
))
749 zlog_debug("Queueing [Hello] Interface(%s)", IF_NAME(ei
));
751 /* if packet was succesfully created, then add it to the interface queue
753 ep
= eigrp_hello_encode(ei
, htonl(EIGRP_MULTICAST_ADDRESS
), 0, flags
,
757 // Add packet to the top of the interface output queue
758 eigrp_fifo_push(ei
->obuf
, ep
);
760 /* Hook thread to write packet. */
761 if (ei
->on_write_q
== 0) {
762 listnode_add(ei
->eigrp
->oi_write_q
, ei
);
766 if (ei
->eigrp
->t_write
== NULL
) {
767 if (flags
& EIGRP_HELLO_GRACEFUL_SHUTDOWN
) {
768 thread_execute(master
, eigrp_write
, ei
->eigrp
,
771 thread_add_write(master
, eigrp_write
, ei
->eigrp
,
773 &ei
->eigrp
->t_write
);