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nhrp: handle draft-detienne-dmvpn-01, improve indication decoding.

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Handle the I-D draft-detienne-dmvpn-01 traffic indication packet.

Print the error code in an error indication symbolically if it's a known
code.

Print the address fields in the mandatory part of the header for error
and traffic indication packets.
This commit is contained in:
Guy Harris 2023-04-12 00:14:53 -07:00
parent 52f602dbea
commit 7a8e7f79c4
2 changed files with 34 additions and 5 deletions
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37
print-nhrp.c
View File

@ -20,6 +20,7 @@
/*
* RFC 2332 NBMA Next Hop Resolution Protocol (NHRP)
* I-D draft-detienne-dmvpn-01 (expired)
*/
#ifdef HAVE_CONFIG_H
@ -45,6 +46,7 @@
#define NHRP_PKT_PURGE_REQUEST 5
#define NHRP_PKT_PURGE_REPLY 6
#define NHRP_PKT_ERROR_INDICATION 7
#define NHRP_PKT_TRAFFIC_INDICATION 8 /* draft-detienne-dmvpn-01 */
static const struct tok pkt_types[] = {
{ NHRP_PKT_RESOLUTION_REQUEST, "res request" },
@ -54,6 +56,7 @@ static const struct tok pkt_types[] = {
{ NHRP_PKT_PURGE_REQUEST, "purge request" },
{ NHRP_PKT_PURGE_REPLY, "purge reply" },
{ NHRP_PKT_ERROR_INDICATION, "error indication" },
{ NHRP_PKT_TRAFFIC_INDICATION, "traffic indication" },
{ 0, NULL }
};
@ -82,8 +85,9 @@ struct nhrp_fixed_header {
*
* The mandatory header part formats are similar for
* all NHRP packets; the only difference is that NHRP_PKT_ERROR_INDICATION
* has a 16-bit error code and a 16-bit error packet offset rather
* than a 32-bit request ID.
* has a 16-bit error code and a 16-bit error packet offset, and
* NHRP_PKT_TRAFFIC_INDICATION has a 16-bit traffic code and a 16-bit unused
* field, rather than a 32-bit request ID.
*/
struct nhrp_mand_header {
nd_uint8_t spl; /* src proto len */
@ -95,9 +99,31 @@ struct nhrp_mand_header {
nd_uint16_t code;
nd_uint16_t offset;
} err;
struct { /* error code */
nd_uint16_t traffic_code;
nd_uint16_t unused;
} tind;
} u;
};
static const struct tok err_code_types[] = {
{ 1, "unrecognized extension" },
{ 3, "NHRP loop detected" },
{ 6, "protocol address unreachable" },
{ 7, "protocol error" },
{ 8, "NHRP SDU size exceeded" },
{ 9, "invalid extension" },
{ 10, "invalid NHRP resolution reply received" },
{ 11, "authentication failure" },
{ 15, "hop count exceeded" },
{ 0, NULL }
};
static const struct tok traffic_code_types[] = {
{ 0, "NHRP traffic redirect/indirection" },
{ 0, NULL }
};
#define NHRP_FIXED_HEADER_LEN 20
struct nhrp_cie {
@ -232,8 +258,11 @@ nhrp_print(netdissect_options *ndo, const u_char *bp, u_int length)
ND_PRINT(", id %u", GET_BE_U_4(mand_hdr->u.id));
break;
case NHRP_PKT_ERROR_INDICATION:
ND_PRINT(", error %u", GET_BE_U_2(mand_hdr->u.err.code));
return;
ND_PRINT(", error <%s>", tok2str(err_code_types, "unknown-err-code-%u", GET_BE_U_2(mand_hdr->u.err.code)));
break;
case NHRP_PKT_TRAFFIC_INDICATION:
ND_PRINT(", code <%s>", tok2str(traffic_code_types, "unknown-traffic-code-%u", GET_BE_U_2(mand_hdr->u.tind.traffic_code)));
break;
}
shtl = GET_U_1(fixed_hdr->shtl);

2
tests/nhrp-trace.out
View File

@ -1,6 +1,6 @@
1 07:11:37.354029 IP (tos 0xc0, ttl 255, id 22, offset 0, flags [none], proto GRE (47), length 126)
192.168.200.1 > 192.168.200.3: GREv0, Flags [key present], key=0x3e8, length 106
NHRP: unknown-op-type-0008, hopcnt 255, src nbma 192.168.200.1, 10.255.255.1 -> 10.255.255.3
NHRP: traffic indication, code <NHRP traffic redirect/indirection>, hopcnt 255, src nbma 192.168.200.1, 10.255.255.1 -> 10.255.255.3
2 07:11:37.366110 IP (tos 0xc0, ttl 255, id 14, offset 0, flags [none], proto GRE (47), length 114)
192.168.200.3 > 192.168.200.1: GREv0, Flags [key present], key=0x3e8, length 94
NHRP: res request, id 5, hopcnt 255, src nbma 192.168.200.3, 10.255.255.3 -> 10.255.255.2 (code 0, pl 0, mtu 1514, htime 7200, pref 0)