tcpdump/print-wb.c
Denis Ovsienko d32231a35b WB: Modernize packet parsing style.
Enable ND_LONGJMP_FROM_TCHECK. Remove ND_TTEST*() instances that were
excess and convert the rest to ND_TCHECK*() with comments. Do not guard
ndo_snapend directly. Make sure that functions specific to message types
do not return on truncated data and return -1 when they have looked deep
enough to tell an invalid packet. In wb_print() deduplicate some code and
report invalid packets as invalid instead of truncated, also consider an
unknown packet type invalid. Update a test.
2020-10-11 12:27:20 +01:00

446 lines
10 KiB
C

/*
* Copyright (c) 1993, 1994, 1995, 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: White Board printer */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "netdissect-stdinc.h"
#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "addrtoname.h"
#include "extract.h"
#if 0
/*
* Largest packet size. Everything should fit within this space.
* For instance, multiline objects are sent piecewise.
*/
#define MAXFRAMESIZE 1024
#endif
/*
* Multiple drawing ops can be sent in one packet. Each one starts on a
* an even multiple of DOP_ALIGN bytes, which must be a power of two.
*/
#define DOP_ALIGN 4
#define DOP_ROUNDUP(x) roundup2(x, DOP_ALIGN)
#define DOP_NEXT(d)\
((const struct dophdr *)((const u_char *)(d) + \
DOP_ROUNDUP(GET_BE_U_2((d)->dh_len) + sizeof(*(d)))))
/*
* Format of the whiteboard packet header.
* The transport level header.
*/
struct pkt_hdr {
nd_uint32_t ph_src; /* site id of source */
nd_uint32_t ph_ts; /* time stamp (for skew computation) */
nd_uint16_t ph_version; /* version number */
nd_uint8_t ph_type; /* message type */
nd_uint8_t ph_flags; /* message flags */
};
/* Packet types */
#define PT_DRAWOP 0 /* drawing operation */
#define PT_ID 1 /* announcement packet */
#define PT_RREQ 2 /* repair request */
#define PT_RREP 3 /* repair reply */
#define PT_KILL 4 /* terminate participation */
#define PT_PREQ 5 /* page vector request */
#define PT_PREP 7 /* page vector reply */
#if 0
#ifdef PF_USER
#undef PF_USER /* {Digital,Tru64} UNIX define this, alas */
#endif
/* flags */
#define PF_USER 0x01 /* hint that packet has interactive data */
#define PF_VIS 0x02 /* only visible ops wanted */
#endif
struct PageID {
nd_uint32_t p_sid; /* session id of initiator */
nd_uint32_t p_uid; /* page number */
};
struct dophdr {
nd_uint32_t dh_ts; /* sender's timestamp */
nd_uint16_t dh_len; /* body length */
nd_uint8_t dh_flags;
nd_uint8_t dh_type; /* body type */
/* body follows */
};
/*
* Drawing op sub-types.
*/
#define DT_RECT 2
#define DT_LINE 3
#define DT_ML 4
#define DT_DEL 5
#define DT_XFORM 6
#define DT_ELL 7
#define DT_CHAR 8
#define DT_STR 9
#define DT_NOP 10
#define DT_PSCODE 11
#define DT_PSCOMP 12
#define DT_REF 13
#define DT_SKIP 14
#define DT_HOLE 15
static const struct tok dop_str[] = {
{ DT_RECT, "RECT" },
{ DT_LINE, "LINE" },
{ DT_ML, "ML" },
{ DT_DEL, "DEL" },
{ DT_XFORM, "XFORM" },
{ DT_ELL, "ELL" },
{ DT_CHAR, "CHAR" },
{ DT_STR, "STR" },
{ DT_NOP, "NOP" },
{ DT_PSCODE, "PSCODE" },
{ DT_PSCOMP, "PSCOMP" },
{ DT_REF, "REF" },
{ DT_SKIP, "SKIP" },
{ DT_HOLE, "HOLE" },
{ 0, NULL }
};
/*
* A drawing operation.
*/
struct pkt_dop {
struct PageID pd_page; /* page that operations apply to */
nd_uint32_t pd_sseq; /* start sequence number */
nd_uint32_t pd_eseq; /* end sequence number */
/* drawing ops follow */
};
/*
* A repair request.
*/
struct pkt_rreq {
nd_uint32_t pr_id; /* source id of drawops to be repaired */
struct PageID pr_page; /* page of drawops */
nd_uint32_t pr_sseq; /* start seqno */
nd_uint32_t pr_eseq; /* end seqno */
};
/*
* A repair reply.
*/
struct pkt_rrep {
nd_uint32_t pr_id; /* original site id of ops */
struct pkt_dop pr_dop;
/* drawing ops follow */
};
struct id_off {
nd_uint32_t id;
nd_uint32_t off;
};
struct pgstate {
nd_uint32_t slot;
struct PageID page;
nd_uint16_t nid;
nd_uint16_t rsvd;
/* seqptr's */
};
/*
* An announcement packet.
*/
struct pkt_id {
nd_uint32_t pi_mslot;
struct PageID pi_mpage; /* current page */
struct pgstate pi_ps;
/* seqptr's */
/* null-terminated site name */
};
struct pkt_preq {
struct PageID pp_page;
nd_uint32_t pp_low;
nd_uint32_t pp_high;
};
struct pkt_prep {
nd_uint32_t pp_n; /* size of pageid array */
/* pgstate's follow */
};
static int
wb_id(netdissect_options *ndo,
const struct pkt_id *id, u_int len)
{
u_int i;
const u_char *sitename;
const struct id_off *io;
char c;
u_int nid;
ND_PRINT(" wb-id:");
if (len < sizeof(*id))
return (-1);
len -= sizeof(*id);
ND_PRINT(" %u/%s:%u (max %u/%s:%u) ",
GET_BE_U_4(id->pi_ps.slot),
GET_IPADDR_STRING(id->pi_ps.page.p_sid),
GET_BE_U_4(id->pi_ps.page.p_uid),
GET_BE_U_4(id->pi_mslot),
GET_IPADDR_STRING(id->pi_mpage.p_sid),
GET_BE_U_4(id->pi_mpage.p_uid));
/* now the rest of the fixed-size part of struct pkt_id */
ND_TCHECK_SIZE(id);
nid = GET_BE_U_2(id->pi_ps.nid);
if (len < sizeof(*io) * nid)
return (-1);
len -= sizeof(*io) * nid;
io = (const struct id_off *)(id + 1);
sitename = (const u_char *)(io + nid);
c = '<';
for (i = 0; i < nid; ++io, ++i) {
ND_PRINT("%c%s:%u",
c, GET_IPADDR_STRING(io->id), GET_BE_U_4(io->off));
c = ',';
}
ND_PRINT("> \"");
(void)nd_print(ndo, sitename, sitename + len);
ND_PRINT("\"");
return (0);
}
static int
wb_rreq(netdissect_options *ndo,
const struct pkt_rreq *rreq, u_int len)
{
ND_PRINT(" wb-rreq:");
if (len < sizeof(*rreq))
return (-1);
ND_PRINT(" please repair %s %s:%u<%u:%u>",
GET_IPADDR_STRING(rreq->pr_id),
GET_IPADDR_STRING(rreq->pr_page.p_sid),
GET_BE_U_4(rreq->pr_page.p_uid),
GET_BE_U_4(rreq->pr_sseq),
GET_BE_U_4(rreq->pr_eseq));
return (0);
}
static int
wb_preq(netdissect_options *ndo,
const struct pkt_preq *preq, u_int len)
{
ND_PRINT(" wb-preq:");
if (len < sizeof(*preq))
return (-1);
ND_PRINT(" need %u/%s:%u",
GET_BE_U_4(preq->pp_low),
GET_IPADDR_STRING(preq->pp_page.p_sid),
GET_BE_U_4(preq->pp_page.p_uid));
/* now the rest of the fixed-size part of struct pkt_req */
ND_TCHECK_SIZE(preq);
return (0);
}
static int
wb_prep(netdissect_options *ndo,
const struct pkt_prep *prep, u_int len)
{
u_int n;
const struct pgstate *ps;
ND_PRINT(" wb-prep:");
if (len < sizeof(*prep))
return (-1);
n = GET_BE_U_4(prep->pp_n);
ps = (const struct pgstate *)(prep + 1);
while (n != 0) {
const struct id_off *io, *ie;
char c = '<';
ND_PRINT(" %u/%s:%u",
GET_BE_U_4(ps->slot),
GET_IPADDR_STRING(ps->page.p_sid),
GET_BE_U_4(ps->page.p_uid));
/* now the rest of the fixed-size part of struct pgstate */
ND_TCHECK_SIZE(ps);
io = (const struct id_off *)(ps + 1);
for (ie = io + GET_U_1(ps->nid); io < ie; ++io) {
ND_PRINT("%c%s:%u", c, GET_IPADDR_STRING(io->id),
GET_BE_U_4(io->off));
c = ',';
}
ND_PRINT(">");
ps = (const struct pgstate *)io;
n--;
}
return 0;
}
static void
wb_dops(netdissect_options *ndo, const struct pkt_dop *dop,
uint32_t ss, uint32_t es)
{
const struct dophdr *dh = (const struct dophdr *)((const u_char *)dop + sizeof(*dop));
ND_PRINT(" <");
for ( ; ss <= es; ++ss) {
u_int t;
t = GET_U_1(dh->dh_type);
ND_PRINT(" %s", tok2str(dop_str, "dop-%u!", t));
if (t == DT_SKIP || t == DT_HOLE) {
uint32_t ts = GET_BE_U_4(dh->dh_ts);
ND_PRINT("%u", ts - ss + 1);
if (ss > ts || ts > es) {
ND_PRINT("[|]");
if (ts < ss)
return;
}
ss = ts;
}
dh = DOP_NEXT(dh);
}
ND_PRINT(" >");
}
static int
wb_rrep(netdissect_options *ndo,
const struct pkt_rrep *rrep, u_int len)
{
const struct pkt_dop *dop = &rrep->pr_dop;
ND_PRINT(" wb-rrep:");
if (len < sizeof(*rrep))
return (-1);
len -= sizeof(*rrep);
ND_PRINT(" for %s %s:%u<%u:%u>",
GET_IPADDR_STRING(rrep->pr_id),
GET_IPADDR_STRING(dop->pd_page.p_sid),
GET_BE_U_4(dop->pd_page.p_uid),
GET_BE_U_4(dop->pd_sseq),
GET_BE_U_4(dop->pd_eseq));
if (ndo->ndo_vflag)
wb_dops(ndo, dop,
GET_BE_U_4(dop->pd_sseq),
GET_BE_U_4(dop->pd_eseq));
return (0);
}
static int
wb_drawop(netdissect_options *ndo,
const struct pkt_dop *dop, u_int len)
{
ND_PRINT(" wb-dop:");
if (len < sizeof(*dop))
return (-1);
len -= sizeof(*dop);
ND_PRINT(" %s:%u<%u:%u>",
GET_IPADDR_STRING(dop->pd_page.p_sid),
GET_BE_U_4(dop->pd_page.p_uid),
GET_BE_U_4(dop->pd_sseq),
GET_BE_U_4(dop->pd_eseq));
if (ndo->ndo_vflag)
wb_dops(ndo, dop,
GET_BE_U_4(dop->pd_sseq),
GET_BE_U_4(dop->pd_eseq));
return (0);
}
/*
* Print whiteboard multicast packets.
*/
void
wb_print(netdissect_options *ndo,
const u_char *hdr, u_int len)
{
const struct pkt_hdr *ph;
uint8_t type;
int print_result;
ndo->ndo_protocol = "wb";
ph = (const struct pkt_hdr *)hdr;
if (len < sizeof(*ph))
goto invalid;
ND_TCHECK_SIZE(ph);
len -= sizeof(*ph);
if (GET_U_1(ph->ph_flags))
ND_PRINT("*");
type = GET_U_1(ph->ph_type);
switch (type) {
case PT_KILL:
ND_PRINT(" wb-kill");
return;
case PT_ID:
print_result = wb_id(ndo, (const struct pkt_id *)(ph + 1), len);
break;
case PT_RREQ:
print_result = wb_rreq(ndo, (const struct pkt_rreq *)(ph + 1), len);
break;
case PT_RREP:
print_result = wb_rrep(ndo, (const struct pkt_rrep *)(ph + 1), len);
break;
case PT_DRAWOP:
print_result = wb_drawop(ndo, (const struct pkt_dop *)(ph + 1), len);
break;
case PT_PREQ:
print_result = wb_preq(ndo, (const struct pkt_preq *)(ph + 1), len);
break;
case PT_PREP:
print_result = wb_prep(ndo, (const struct pkt_prep *)(ph + 1), len);
break;
default:
ND_PRINT(" wb-%u!", type);
print_result = -1;
}
if (print_result < 0)
goto invalid;
return;
invalid:
nd_print_invalid(ndo);
}