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per George Bakos' suggestion:

Browse Source 
backout some of the v1.118 changes
  now we hide frag processing under the
  vflag option where we print: id, offset.
    plus the (+,DF,res) flags using bittok2string

    also decode the rfc3514 "evil" bit to keep the security
    guys happy;
This commit is contained in:
hannes 2003-04-24 12:51:35 +00:00
parent 99c03187af
commit 4a6df9a1d8
1 changed files with 56 additions and 56 deletions
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112
print-ip.c
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@ -21,7 +21,7 @@
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.120 2003-02-05 02:30:39 guy Exp $ (LBL)";
"@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.121 2003-04-24 12:51:35 hannes Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
@ -339,6 +339,21 @@ in_cksum_shouldbe(u_int16_t sum, u_int16_t computed_sum)
return shouldbe;
}
#ifndef IP_MF
#define IP_MF 0x2000
#endif /* IP_MF */
#ifndef IP_DF
#define IP_DF 0x4000
#endif /* IP_DF */
#define IP_RES 0x8000
static struct tok ip_frag_values[] = {
{ IP_MF, "+" },
{ IP_DF, "DF" },
{ IP_RES, "rsvd" }, /* The RFC3514 evil ;-) bit */
{ 0, NULL }
};
/*
* print an IP datagram.
*/
@ -351,6 +366,8 @@ ip_print(register const u_char *bp, register u_int length)
u_char nh;
int advance;
struct protoent *proto;
u_int16_t sum, ip_sum;
const char *sep = "";
ip = (const struct ip *)bp;
if ((u_char *)(ip + 1) > snapend) {
@ -395,8 +412,16 @@ ip_print(register const u_char *bp, register u_int length)
if (ip->ip_ttl >= 1)
(void)printf(", ttl %u", ip->ip_ttl);
if ((off & 0x3fff) != 0)
(void)printf(", id %u", EXTRACT_16BITS(&ip->ip_id));
/*
* for the firewall guys, print id, offset.
* On all but the last stick a "+" in the flags portion.
* For unfragmented datagrams, note the don't fragment flag.
*/
(void)printf(", id %u, offset %u, flags [%s]",
EXTRACT_16BITS(&ip->ip_id),
(off & 0x1fff) * 8,
bittok2str(ip_frag_values, "none", off & 0xe000 ));
(void)printf(", length: %u", EXTRACT_16BITS(&ip->ip_len));
@ -405,6 +430,18 @@ ip_print(register const u_char *bp, register u_int length)
ip_optprint((u_char *)(ip + 1), hlen - sizeof(struct ip));
printf(" )");
}
if ((u_char *)ip + hlen <= snapend) {
sum = in_cksum((const u_short *)ip, hlen, 0);
if (sum != 0) {
ip_sum = EXTRACT_16BITS(&ip->ip_sum);
(void)printf("%sbad cksum %x (->%x)!", sep,
ip_sum,
in_cksum_shouldbe(ip_sum, sum));
sep = ", ";
}
}
printf(") ");
}
@ -575,60 +612,23 @@ again:
printf(" %d", len);
break;
}
}
} else {
/* Ultra quiet now means that all this stuff should be suppressed */
if (qflag > 1) return;
/* Ultra quiet now means that all this stuff should be suppressed */
/* res 3-Nov-98 */
if (qflag > 1) return;
/*
* for fragmented datagrams, print id:size@offset. On all
* but the last stick a "+". For unfragmented datagrams, note
* the don't fragment flag.
*/
len = len0; /* get the original length */
if (off & 0x3fff) {
/*
* if this isn't the first frag, we're missing the
* next level protocol header. print the ip addr
* and the protocol.
*/
if (off & 0x1fff) {
(void)printf("%s > %s:", ipaddr_string(&ip->ip_src),
ipaddr_string(&ip->ip_dst));
if ((proto = getprotobynumber(ip->ip_p)) != NULL)
(void)printf(" %s", proto->p_name);
else
(void)printf(" ip-proto-%d", ip->ip_p);
}
#ifndef IP_MF
#define IP_MF 0x2000
#endif /* IP_MF */
#ifndef IP_DF
#define IP_DF 0x4000
#endif /* IP_DF */
(void)printf(" (frag %u:%u@%u%s)", EXTRACT_16BITS(&ip->ip_id), len,
(off & 0x1fff) * 8,
(off & IP_MF)? "+" : "");
} else if (off & IP_DF)
(void)printf(" (DF)");
if (vflag) {
u_int16_t sum, ip_sum;
const char *sep = "";
if ((u_char *)ip + hlen <= snapend) {
sum = in_cksum((const u_short *)ip, hlen, 0);
if (sum != 0) {
ip_sum = EXTRACT_16BITS(&ip->ip_sum);
(void)printf("%sbad cksum %x (->%x)!", sep,
ip_sum,
in_cksum_shouldbe(ip_sum, sum));
sep = ", ";
}
}
/*
* if this isn't the first frag, we're missing the
* next level protocol header. print the ip addr
* and the protocol.
*/
if (off & 0x1fff) {
(void)printf("%s > %s:", ipaddr_string(&ip->ip_src),
ipaddr_string(&ip->ip_dst));
if ((proto = getprotobynumber(ip->ip_p)) != NULL)
(void)printf(" %s", proto->p_name);
else
(void)printf(" ip-proto-%d", ip->ip_p);
}
}
}