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tcpdump/print-rip.c
Guy Harris 306c2a0384 More bounds checking when fetching addresses and converting to strings. 
Replace more calls to ipaddr_string()/ip6addr_string() with calls to
GET_IPADDR_STRING()/GET_IP6ADDR_STRING() macros performing bounds
checking.

Add similar bounds-checking inline functions and macros to wrap
linkaddr_string(), etheraddr_string(), and isonsap_string() and convert
calls to them to use the macros as well.

Shuffle the inline functions in addrtoname.h around a bit, so that the
inline functions, external declarations, and macros are all in the same
order.
2020-01-19 19:55:38 -08:00

426 lines
13 KiB
C
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/*
* Copyright (c) 1989, 1990, 1991, 1993, 1994, 1996
* The Regents of the University of California. All rights reserved.
*
* 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, (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, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may 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.
*/
/* \summary: Routing Information Protocol (RIP) printer */
/* specification: RFC 1058, RFC 2453, RFC 4822 */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#include <stdio.h>
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
#include "af.h"
/*
* RFC 1058 and RFC 2453 header of packet.
*
* 0 1 2 3 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Command (1) | Version (1) | unused |
* +---------------+---------------+-------------------------------+
*/
struct rip {
nd_uint8_t rip_cmd; /* request/response */
nd_uint8_t rip_vers; /* protocol version # */
nd_byte unused[2]; /* unused */
};
#define RIPCMD_REQUEST 1 /* want info */
#define RIPCMD_RESPONSE 2 /* responding to request */
#define RIPCMD_TRACEON 3 /* turn tracing on */
#define RIPCMD_TRACEOFF 4 /* turn it off */
#define RIPCMD_POLL 5 /* want info from everybody */
#define RIPCMD_POLLENTRY 6 /* poll for entry */
static const struct tok rip_cmd_values[] = {
{ RIPCMD_REQUEST, "Request" },
{ RIPCMD_RESPONSE, "Response" },
{ RIPCMD_TRACEON, "Trace on" },
{ RIPCMD_TRACEOFF, "Trace off" },
{ RIPCMD_POLL, "Poll" },
{ RIPCMD_POLLENTRY, "Poll Entry" },
{ 0, NULL}
};
#define RIP_AUTHLEN 16
#define RIP_ROUTELEN 20
/*
* First 4 bytes of all RIPv1/RIPv2 entries.
*/
struct rip_entry_header {
nd_uint16_t rip_family;
nd_uint16_t rip_tag;
};
/*
* RFC 1058 entry.
*
* 0 1 2 3 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Address Family Identifier (2) | must be zero (2) |
* +-------------------------------+-------------------------------+
* | IP Address (4) |
* +---------------------------------------------------------------+
* | must be zero (4) |
* +---------------------------------------------------------------+
* | must be zero (4) |
* +---------------------------------------------------------------+
* | Metric (4) |
* +---------------------------------------------------------------+
*/
struct rip_netinfo_v1 {
nd_uint16_t rip_family;
nd_byte rip_mbz1[2];
nd_ipv4 rip_dest;
nd_byte rip_mbz2[4];
nd_byte rip_mbz3[4];
nd_uint32_t rip_metric; /* cost of route */
};
/*
* RFC 2453 route entry
*
* 0 1 2 3 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Address Family Identifier (2) | Route Tag (2) |
* +-------------------------------+-------------------------------+
* | IP Address (4) |
* +---------------------------------------------------------------+
* | Subnet Mask (4) |
* +---------------------------------------------------------------+
* | Next Hop (4) |
* +---------------------------------------------------------------+
* | Metric (4) |
* +---------------------------------------------------------------+
*
*/
struct rip_netinfo_v2 {
nd_uint16_t rip_family;
nd_uint16_t rip_tag;
nd_ipv4 rip_dest;
nd_uint32_t rip_dest_mask;
nd_ipv4 rip_router;
nd_uint32_t rip_metric; /* cost of route */
};
/*
* RFC 2453 authentication entry
*
* 0 1 2 3 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | 0xFFFF | Authentication Type (2) |
* +-------------------------------+-------------------------------+
* - Authentication (16) -
* +---------------------------------------------------------------+
*/
struct rip_auth_v2 {
nd_uint16_t rip_family;
nd_uint16_t rip_tag;
nd_byte rip_auth[16];
};
/*
* RFC 4822 Cryptographic Authentication entry.
*
* 0 1 2 3 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | RIPv2 Packet Length | Key ID | Auth Data Len |
* +---------------+---------------+---------------+---------------+
* | Sequence Number (non-decreasing) |
* +---------------+---------------+---------------+---------------+
* | reserved must be zero |
* +---------------+---------------+---------------+---------------+
* | reserved must be zero |
* +---------------+---------------+---------------+---------------+
*/
struct rip_auth_crypto_v2 {
nd_uint16_t rip_packet_len;
nd_uint8_t rip_key_id;
nd_uint8_t rip_auth_data_len;
nd_uint32_t rip_seq_num;
nd_byte rip_mbz1[4];
nd_byte rip_mbz2[4];
};
static unsigned
rip_entry_print_v1(netdissect_options *ndo, const u_char *p,
unsigned remaining)
{
const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
u_short family;
const struct rip_netinfo_v1 *ni = (const struct rip_netinfo_v1 *)p;
/* RFC 1058 */
if (remaining < RIP_ROUTELEN)
return (0);
ND_TCHECK_SIZE(ni);
family = GET_BE_U_2(ni->rip_family);
if (family != BSD_AFNUM_INET && family != 0) {
ND_PRINT("\n\t AFI %s, ", tok2str(bsd_af_values, "Unknown (%u)", family));
print_unknown_data(ndo, p + sizeof(*eh), "\n\t ", RIP_ROUTELEN - sizeof(*eh));
return (RIP_ROUTELEN);
}
if (GET_BE_U_2(ni->rip_mbz1) ||
GET_BE_U_4(ni->rip_mbz2) ||
GET_BE_U_4(ni->rip_mbz3)) {
/* MBZ fields not zero */
print_unknown_data(ndo, p, "\n\t ", RIP_ROUTELEN);
return (RIP_ROUTELEN);
}
if (family == 0) {
ND_PRINT("\n\t AFI 0, %s, metric: %u",
GET_IPADDR_STRING(ni->rip_dest),
GET_BE_U_4(ni->rip_metric));
return (RIP_ROUTELEN);
} /* BSD_AFNUM_INET */
ND_PRINT("\n\t %s, metric: %u",
GET_IPADDR_STRING(ni->rip_dest),
GET_BE_U_4(ni->rip_metric));
return (RIP_ROUTELEN);
trunc:
return 0;
}
static unsigned
rip_entry_print_v2(netdissect_options *ndo, const u_char *p,
unsigned remaining)
{
const struct rip_entry_header *eh = (const struct rip_entry_header *)p;
u_short family;
const struct rip_netinfo_v2 *ni;
if (remaining < sizeof(*eh))
return (0);
ND_TCHECK_SIZE(eh);
family = GET_BE_U_2(eh->rip_family);
if (family == 0xFFFF) { /* variable-sized authentication structures */
uint16_t auth_type = GET_BE_U_2(eh->rip_tag);
p += sizeof(*eh);
remaining -= sizeof(*eh);
if (auth_type == 2) {
ND_PRINT("\n\t Simple Text Authentication data: ");
if (nd_printzp(ndo, p, RIP_AUTHLEN, p + remaining))
return (0);
} else if (auth_type == 3) {
const struct rip_auth_crypto_v2 *ch;
ch = (const struct rip_auth_crypto_v2 *)p;
ND_TCHECK_SIZE(ch);
if (remaining < sizeof(*ch))
return (0);
ND_PRINT("\n\t Auth header:");
ND_PRINT(" Packet Len %u,",
GET_BE_U_2(ch->rip_packet_len));
ND_PRINT(" Key-ID %u,", GET_U_1(ch->rip_key_id));
ND_PRINT(" Auth Data Len %u,",
GET_U_1(ch->rip_auth_data_len));
ND_PRINT(" SeqNo %u,", GET_BE_U_4(ch->rip_seq_num));
ND_PRINT(" MBZ %u,", GET_BE_U_4(ch->rip_mbz1));
ND_PRINT(" MBZ %u", GET_BE_U_4(ch->rip_mbz2));
} else if (auth_type == 1) {
ND_PRINT("\n\t Auth trailer:");
print_unknown_data(ndo, p, "\n\t ", remaining);
return (sizeof(*eh) + remaining); /* AT spans till the packet end */
} else {
ND_PRINT("\n\t Unknown (%u) Authentication data:",
auth_type);
print_unknown_data(ndo, p, "\n\t ", remaining);
return (sizeof(*eh) + remaining); /* we don't know how long this is, so we go to the packet end */
}
} else if (family != BSD_AFNUM_INET && family != 0) {
ND_PRINT("\n\t AFI %s", tok2str(bsd_af_values, "Unknown (%u)", family));
print_unknown_data(ndo, p + sizeof(*eh), "\n\t ", RIP_ROUTELEN - sizeof(*eh));
} else { /* BSD_AFNUM_INET or AFI 0 */
ni = (const struct rip_netinfo_v2 *)p;
ND_TCHECK_SIZE(ni);
if (remaining < sizeof(*ni))
return (0);
ND_PRINT("\n\t AFI %s, %15s/%-2d, tag 0x%04x, metric: %u, next-hop: ",
tok2str(bsd_af_values, "%u", family),
GET_IPADDR_STRING(ni->rip_dest),
mask2plen(GET_BE_U_4(ni->rip_dest_mask)),
GET_BE_U_2(ni->rip_tag),
GET_BE_U_4(ni->rip_metric));
if (GET_BE_U_4(ni->rip_router))
ND_PRINT("%s", GET_IPADDR_STRING(ni->rip_router));
else
ND_PRINT("self");
}
return (RIP_ROUTELEN);
trunc:
return 0;
}
void
rip_print(netdissect_options *ndo,
const u_char *dat, u_int length)
{
const struct rip *rp;
uint8_t vers, cmd;
const u_char *p;
u_int len, routecount;
unsigned entry_size;
ndo->ndo_protocol = "rip";
if (ndo->ndo_snapend < dat) {
nd_print_trunc(ndo);
return;
}
len = ND_BYTES_AVAILABLE_AFTER(dat);
if (len > length)
len = length;
if (len < sizeof(*rp)) {
nd_print_trunc(ndo);
return;
}
len -= sizeof(*rp);
rp = (const struct rip *)dat;
ND_TCHECK_SIZE(rp);
vers = GET_U_1(rp->rip_vers);
ND_PRINT("%sRIPv%u",
(ndo->ndo_vflag >= 1) ? "\n\t" : "",
vers);
if (vers == 0) {
/*
* RFC 1058.
*
* XXX - RFC 1058 says
*
* 0 Datagrams whose version number is zero are to be ignored.
* These are from a previous version of the protocol, whose
* packet format was machine-specific.
*
* so perhaps we should just dump the packet, in hex.
*/
print_unknown_data(ndo, (const uint8_t *)&rp->rip_cmd, "\n\t", length);
return;
}
/* dump version and lets see if we know the commands name*/
cmd = GET_U_1(rp->rip_cmd);
ND_PRINT(", %s, length: %u",
tok2str(rip_cmd_values, "unknown command (%u)", cmd),
length);
if (ndo->ndo_vflag < 1)
return;
switch (cmd) {
case RIPCMD_REQUEST:
case RIPCMD_RESPONSE:
switch (vers) {
case 1:
routecount = length / RIP_ROUTELEN;
ND_PRINT(", routes: %u", routecount);
p = (const u_char *)(rp + 1);
while (len != 0) {
entry_size = rip_entry_print_v1(ndo, p, len);
if (entry_size == 0) {
/* Error */
nd_print_trunc(ndo);
break;
}
if (len < entry_size) {
ND_PRINT(" [remaining entries length %u < %u]",
len, entry_size);
nd_print_invalid(ndo);
break;
}
p += entry_size;
len -= entry_size;
}
break;
case 2:
routecount = length / RIP_ROUTELEN;
ND_PRINT(", routes: %u or less", routecount);
p = (const u_char *)(rp + 1);
while (len != 0) {
entry_size = rip_entry_print_v2(ndo, p, len);
if (entry_size == 0) {
/* Error */
nd_print_trunc(ndo);
break;
}
if (len < entry_size) {
ND_PRINT(" [remaining entries length %u < %u]",
len, entry_size);
nd_print_invalid(ndo);
break;
}
p += entry_size;
len -= entry_size;
}
break;
default:
ND_PRINT(", unknown version");
break;
}
break;
case RIPCMD_TRACEOFF:
case RIPCMD_POLL:
case RIPCMD_POLLENTRY:
break;
case RIPCMD_TRACEON:
/* fall through */
default:
if (ndo->ndo_vflag <= 1) {
if (!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
return;
}
break;
}
/* do we want to see an additionally hexdump ? */
if (ndo->ndo_vflag> 1) {
if (!print_unknown_data(ndo, (const uint8_t *)rp, "\n\t", length))
return;
}
trunc:
return;
}
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