/*
* Copyright (c) 1991, 1992, 1993, 1994, 1995, 1996
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Lawrence Berkeley Laboratory,
* Berkeley, CA. The name of the University may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
* 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.
*
* Initial contribution from Jeff Honig (jch@MITCHELL.CIT.CORNELL.EDU).
*/
/* \summary: Exterior Gateway Protocol (EGP) printer */
/* specification: RFC 827 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
struct egp_packet {
nd_uint8_t egp_version;
#define EGP_VERSION 2
nd_uint8_t egp_type;
#define EGPT_ACQUIRE 3
#define EGPT_REACH 5
#define EGPT_POLL 2
#define EGPT_UPDATE 1
#define EGPT_ERROR 8
nd_uint8_t egp_code;
#define EGPC_REQUEST 0
#define EGPC_CONFIRM 1
#define EGPC_REFUSE 2
#define EGPC_CEASE 3
#define EGPC_CEASEACK 4
#define EGPC_HELLO 0
#define EGPC_HEARDU 1
nd_uint8_t egp_status;
#define EGPS_UNSPEC 0
#define EGPS_ACTIVE 1
#define EGPS_PASSIVE 2
#define EGPS_NORES 3
#define EGPS_ADMIN 4
#define EGPS_GODOWN 5
#define EGPS_PARAM 6
#define EGPS_PROTO 7
#define EGPS_INDET 0
#define EGPS_UP 1
#define EGPS_DOWN 2
#define EGPS_UNSOL 0x80
nd_uint16_t egp_checksum;
nd_uint16_t egp_as;
nd_uint16_t egp_sequence;
union {
nd_uint16_t egpu_hello;
nd_uint8_t egpu_gws[2];
nd_uint16_t egpu_reason;
#define EGPR_UNSPEC 0
#define EGPR_BADHEAD 1
#define EGPR_BADDATA 2
#define EGPR_NOREACH 3
#define EGPR_XSPOLL 4
#define EGPR_NORESP 5
#define EGPR_UVERSION 6
} egp_handg;
#define egp_hello egp_handg.egpu_hello
#define egp_intgw egp_handg.egpu_gws[0]
#define egp_extgw egp_handg.egpu_gws[1]
#define egp_reason egp_handg.egpu_reason
union {
nd_uint16_t egpu_poll;
nd_ipv4 egpu_sourcenet;
} egp_pands;
#define egp_poll egp_pands.egpu_poll
#define egp_sourcenet egp_pands.egpu_sourcenet
};
static const char *egp_acquire_codes[] = {
"request",
"confirm",
"refuse",
"cease",
"cease_ack"
};
static const char *egp_acquire_status[] = {
"unspecified",
"active_mode",
"passive_mode",
"insufficient_resources",
"administratively_prohibited",
"going_down",
"parameter_violation",
"protocol_violation"
};
static const char *egp_reach_codes[] = {
"hello",
"i-h-u"
};
static const char *egp_status_updown[] = {
"indeterminate",
"up",
"down"
};
static const char *egp_reasons[] = {
"unspecified",
"bad_EGP_header_format",
"bad_EGP_data_field_format",
"reachability_info_unavailable",
"excessive_polling_rate",
"no_response",
"unsupported_version"
};
static void
egpnr_print(netdissect_options *ndo,
const struct egp_packet *egp, u_int length)
{
const uint8_t *cp;
uint32_t addr;
uint32_t net;
u_int netlen;
u_int gateways, distances, networks;
u_int intgw, extgw, t_gateways;
const char *comma;
addr = GET_IPV4_TO_NETWORK_ORDER(egp->egp_sourcenet);
if (IN_CLASSA(addr)) {
net = addr & IN_CLASSA_NET;
netlen = 1;
} else if (IN_CLASSB(addr)) {
net = addr & IN_CLASSB_NET;
netlen = 2;
} else if (IN_CLASSC(addr)) {
net = addr & IN_CLASSC_NET;
netlen = 3;
} else {
net = 0;
netlen = 0;
}
cp = (const uint8_t *)(egp + 1);
length -= sizeof(*egp);
intgw = GET_U_1(egp->egp_intgw);
extgw = GET_U_1(egp->egp_extgw);
t_gateways = intgw + extgw;
for (gateways = 0; gateways < t_gateways; ++gateways) {
/* Pickup host part of gateway address */
addr = 0;
if (length < 4 - netlen)
goto trunc;
ND_TCHECK_LEN(cp, 4 - netlen);
switch (netlen) {
case 1:
addr = GET_U_1(cp);
cp++;
/* fall through */
case 2:
addr = (addr << 8) | GET_U_1(cp);
cp++;
/* fall through */
case 3:
addr = (addr << 8) | GET_U_1(cp);
cp++;
break;
}
addr |= net;
length -= 4 - netlen;
if (length < 1)
goto trunc;
distances = GET_U_1(cp);
cp++;
length--;
ND_PRINT(" %s %s ",
gateways < intgw ? "int" : "ext",
ipaddr_string(ndo, (const u_char *)&addr));
comma = "";
ND_PRINT("(");
while (distances != 0) {
if (length < 2)
goto trunc;
ND_PRINT("%sd%u:", comma, GET_U_1(cp));
cp++;
comma = ", ";
networks = GET_U_1(cp);
cp++;
length -= 2;
while (networks != 0) {
/* Pickup network number */
if (length < 1)
goto trunc;
addr = ((uint32_t) GET_U_1(cp)) << 24;
cp++;
length--;
if (IN_CLASSB(addr)) {
if (length < 1)
goto trunc;
addr |= ((uint32_t) GET_U_1(cp)) << 16;
cp++;
length--;
} else if (!IN_CLASSA(addr)) {
if (length < 2)
goto trunc;
addr |= ((uint32_t) GET_U_1(cp)) << 16;
cp++;
addr |= ((uint32_t) GET_U_1(cp)) << 8;
cp++;
length -= 2;
}
ND_PRINT(" %s", ipaddr_string(ndo, (const u_char *)&addr));
networks--;
}
distances--;
}
ND_PRINT(")");
}
return;
trunc:
nd_print_trunc(ndo);
}
void
egp_print(netdissect_options *ndo,
const uint8_t *bp, u_int length)
{
const struct egp_packet *egp;
u_int version;
u_int type;
u_int code;
u_int status;
ndo->ndo_protocol = "egp";
egp = (const struct egp_packet *)bp;
if (length < sizeof(*egp) || !ND_TTEST_SIZE(egp)) {
nd_print_trunc(ndo);
return;
}
version = GET_U_1(egp->egp_version);
if (!ndo->ndo_vflag) {
ND_PRINT("EGPv%u, AS %u, seq %u, length %u",
version,
GET_BE_U_2(egp->egp_as),
GET_BE_U_2(egp->egp_sequence),
length);
return;
} else
ND_PRINT("EGPv%u, length %u",
version,
length);
if (version != EGP_VERSION) {
ND_PRINT("[version %u]", version);
return;
}
type = GET_U_1(egp->egp_type);
code = GET_U_1(egp->egp_code);
status = GET_U_1(egp->egp_status);
switch (type) {
case EGPT_ACQUIRE:
ND_PRINT(" acquire");
switch (code) {
case EGPC_REQUEST:
case EGPC_CONFIRM:
ND_PRINT(" %s", egp_acquire_codes[code]);
switch (status) {
case EGPS_UNSPEC:
case EGPS_ACTIVE:
case EGPS_PASSIVE:
ND_PRINT(" %s", egp_acquire_status[status]);
break;
default:
ND_PRINT(" [status %u]", status);
break;
}
ND_PRINT(" hello:%u poll:%u",
GET_BE_U_2(egp->egp_hello),
GET_BE_U_2(egp->egp_poll));
break;
case EGPC_REFUSE:
case EGPC_CEASE:
case EGPC_CEASEACK:
ND_PRINT(" %s", egp_acquire_codes[code]);
switch (status ) {
case EGPS_UNSPEC:
case EGPS_NORES:
case EGPS_ADMIN:
case EGPS_GODOWN:
case EGPS_PARAM:
case EGPS_PROTO:
ND_PRINT(" %s", egp_acquire_status[status]);
break;
default:
ND_PRINT("[status %u]", status);
break;
}
break;
default:
ND_PRINT("[code %u]", code);
break;
}
break;
case EGPT_REACH:
switch (code) {
case EGPC_HELLO:
case EGPC_HEARDU:
ND_PRINT(" %s", egp_reach_codes[code]);
if (status <= EGPS_DOWN)
ND_PRINT(" state:%s", egp_status_updown[status]);
else
ND_PRINT(" [status %u]", status);
break;
default:
ND_PRINT("[reach code %u]", code);
break;
}
break;
case EGPT_POLL:
ND_PRINT(" poll");
if (status <= EGPS_DOWN)
ND_PRINT(" state:%s", egp_status_updown[status]);
else
ND_PRINT(" [status %u]", status);
ND_PRINT(" net:%s", GET_IPADDR_STRING(egp->egp_sourcenet));
break;
case EGPT_UPDATE:
ND_PRINT(" update");
if (status & EGPS_UNSOL) {
status &= ~EGPS_UNSOL;
ND_PRINT(" unsolicited");
}
if (status <= EGPS_DOWN)
ND_PRINT(" state:%s", egp_status_updown[status]);
else
ND_PRINT(" [status %u]", status);
ND_PRINT(" %s int %u ext %u",
GET_IPADDR_STRING(egp->egp_sourcenet),
GET_U_1(egp->egp_intgw),
GET_U_1(egp->egp_extgw));
if (ndo->ndo_vflag)
egpnr_print(ndo, egp, length);
break;
case EGPT_ERROR:
ND_PRINT(" error");
if (status <= EGPS_DOWN)
ND_PRINT(" state:%s", egp_status_updown[status]);
else
ND_PRINT(" [status %u]", status);
if (GET_BE_U_2(egp->egp_reason) <= EGPR_UVERSION)
ND_PRINT(" %s",
egp_reasons[GET_BE_U_2(egp->egp_reason)]);
else
ND_PRINT(" [reason %u]", GET_BE_U_2(egp->egp_reason));
break;
default:
ND_PRINT("[type %u]", type);
break;
}
}