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- Make -M mask and -M time exclusive.

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- Correct some problems with packet construction.

  +--------+------------+----------+-------------+---------+
  |        |            |          |             |         |
  | IP Hdr | MINICMPLEN | phdr_len | TIMEVAL_LEN | payload |
  |        |            |          |             |         |
  +--------+------------+----------+-------------+---------+
  |        |                       |                       |
  |<- IP ->|<------- ICMP -------->|<------ datalen ------>|

My previous changes tried to mess around with 'datalen' instead of
modifying 'phdr_len'.

I'm including this nice ASCII diagram (from Maxim) to further clarify things
in CVS history.

Submitted by:	 Maxim Konovalov <maxim@macomnet.ru>
This commit is contained in:
Matthew N. Dodd 2003-03-24 23:48:36 +00:00
parent 0d98179d63
commit d829c3dfee
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=112568
1 changed files with 21 additions and 22 deletions
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43
sbin/ping/ping.c
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@ -167,7 +167,6 @@ int ident; /* process id to identify our packets */
int uid; /* cached uid for micro-optimization */
u_char icmp_type = ICMP_ECHO;
u_char icmp_type_rsp = ICMP_ECHOREPLY;
int timeoffset = 0;
int phdr_len = 0;
/* counters */
@ -439,31 +438,33 @@ main(argc, argv)
usage();
target = argv[optind];
maxpayload = IP_MAXPACKET - sizeof(struct ip) - MINICMPLEN;
if (options & F_MASK) {
switch (options & (F_MASK|F_TIME)) {
case 0: break;
case F_MASK:
icmp_type = ICMP_MASKREQ;
icmp_type_rsp = ICMP_MASKREPLY;
timeoffset = MASK_LEN;
datalen -= MASK_LEN;
phdr_len += MASK_LEN;
phdr_len = MASK_LEN;
if (!(options & F_QUIET))
(void)printf("ICMP_MASKREQ\n");
}
if (options & F_TIME) {
break;
case F_TIME:
icmp_type = ICMP_TSTAMP;
icmp_type_rsp = ICMP_TSTAMPREPLY;
timeoffset = TS_LEN;
datalen -= TS_LEN;
phdr_len += TS_LEN;
phdr_len = TS_LEN;
if (!(options & F_QUIET))
(void)printf("ICMP_TSTAMP\n");
break;
default:
errx(EX_USAGE, "ICMP_TSTAMP and ICMP_MASKREQ are exclusive.");
break;
}
maxpayload = IP_MAXPACKET - sizeof(struct ip) - MINICMPLEN - phdr_len;
if (options & F_RROUTE)
maxpayload -= MAX_IPOPTLEN;
if (datalen > maxpayload)
errx(EX_USAGE, "packet size too large: %d > %d", datalen,
maxpayload);
datap = &outpack[MINICMPLEN + phdr_len];
datap = &outpack[MINICMPLEN + phdr_len + TIMEVAL_LEN];
if (options & F_PINGFILLED) {
fill((char *)datap, payload);
}
@ -524,16 +525,13 @@ main(argc, argv)
errx(EX_USAGE,
"-I, -L, -T flags cannot be used with unicast destination");
if (datalen - TIMEVAL_LEN >= TIMEVAL_LEN) { /* can we time transfer */
datalen -= TIMEVAL_LEN;
phdr_len += TIMEVAL_LEN;
if (datalen >= TIMEVAL_LEN) /* can we time transfer */
timing = 1;
}
packlen = MAXIPLEN + MAXICMPLEN + datalen;
packlen = packlen > IP_MAXPACKET ? IP_MAXPACKET : packlen;
if (!(options & F_PINGFILLED))
for (i = phdr_len; i < datalen; ++i)
for (i = TIMEVAL_LEN; i < datalen; ++i)
*datap++ = i;
ident = getpid() & 0xFFFF;
@ -869,11 +867,12 @@ pinger(void)
icp->icmp_otime = htonl((now.tv_sec % (24*60*60))
* 1000 + now.tv_usec / 1000);
if (timing)
bcopy((void *)&now, (void *)&outpack[MINICMPLEN + timeoffset],
sizeof(struct timeval));
bcopy((void *)&now,
(void *)&outpack[MINICMPLEN + phdr_len],
sizeof(struct timeval));
}
cc = MINICMPLEN + datalen + timeoffset;
cc = MINICMPLEN + phdr_len + datalen;
/* compute ICMP checksum here */
icp->icmp_cksum = in_cksum((u_short *)icp, cc);
@ -954,7 +953,7 @@ pr_pack(buf, cc, from, tv)
#else
tp = icp->icmp_data;
#endif
tp+=timeoffset;
tp += phdr_len;
/* Copy to avoid alignment problems: */
memcpy(&tv1, tp, sizeof(tv1));
@ -1565,7 +1564,7 @@ fill(bp, patp)
&pat[13], &pat[14], &pat[15]);
if (ii > 0)
for (kk = 0; kk <= maxpayload - (phdr_len + ii); kk += ii)
for (kk = 0; kk <= maxpayload - (TIMEVAL_LEN + ii); kk += ii)
for (jj = 0; jj < ii; ++jj)
bp[jj + kk] = pat[jj];
if (!(options & F_QUIET)) {