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[master] Corrected error in UDP bad packet logging

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Merges in rt36897
This commit is contained in:
Thomas Markwalder
2014-09-08 09:31:32 -04:00
parent 3956569b0d
commit 0ce1aa9445
2 changed files with 38 additions and 20 deletions
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55
common/packet.c
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@@ -3,7 +3,7 @@
Packet assembly code, originally contributed by Archie Cobbs. */
/*
* Copyright (c) 2009,2012 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 2009,2012,2014 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 2004,2005,2007 by Internet Systems Consortium, Inc. ("ISC")
* Copyright (c) 1996-2003 by Internet Software Consortium
*
@@ -234,12 +234,12 @@ decode_udp_ip_header(struct interface_info *interface,
unsigned char *upp, *endbuf;
u_int32_t ip_len, ulen, pkt_len;
u_int32_t sum, usum;
static int ip_packets_seen;
static int ip_packets_bad_checksum;
static int udp_packets_seen;
static int udp_packets_bad_checksum;
static int udp_packets_length_checked;
static int udp_packets_length_overflow;
static unsigned int ip_packets_seen = 0;
static unsigned int ip_packets_bad_checksum = 0;
static unsigned int udp_packets_seen = 0;
static unsigned int udp_packets_bad_checksum = 0;
static unsigned int udp_packets_length_checked = 0;
static unsigned int udp_packets_length_overflow = 0;
unsigned len;
/* Designate the end of the input buffer for bounds checks. */
@@ -287,10 +287,10 @@ decode_udp_ip_header(struct interface_info *interface,
udp_packets_length_checked++;
if ((upp + ulen) > endbuf) {
udp_packets_length_overflow++;
if ((udp_packets_length_checked > 4) &&
((udp_packets_length_checked /
udp_packets_length_overflow) < 2)) {
log_info("%d udp packets in %d too long - dropped",
if (((udp_packets_length_checked > 4) &&
(udp_packets_length_overflow != 0)) &&
((udp_packets_length_checked / udp_packets_length_overflow) < 2)) {
log_info("%u udp packets in %u too long - dropped",
udp_packets_length_overflow,
udp_packets_length_checked);
udp_packets_length_overflow = 0;
@@ -299,22 +299,31 @@ decode_udp_ip_header(struct interface_info *interface,
return -1;
}
if ((ulen < sizeof(udp)) || ((upp + ulen) > endbuf))
return -1;
/* If at least 5 with less than 50% bad, start over */
if (udp_packets_length_checked > 4) {
udp_packets_length_overflow = 0;
udp_packets_length_checked = 0;
}
/* Check the IP header checksum - it should be zero. */
++ip_packets_seen;
ip_packets_seen++;
if (wrapsum (checksum (buf + bufix, ip_len, 0))) {
++ip_packets_bad_checksum;
if (ip_packets_seen > 4 &&
(ip_packets_seen / ip_packets_bad_checksum) < 2) {
log_info ("%d bad IP checksums seen in %d packets",
if (((ip_packets_seen > 4) && (ip_packets_bad_checksum != 0)) &&
((ip_packets_seen / ip_packets_bad_checksum) < 2)) {
log_info ("%u bad IP checksums seen in %u packets",
ip_packets_bad_checksum, ip_packets_seen);
ip_packets_seen = ip_packets_bad_checksum = 0;
}
return -1;
}
/* If at least 5 with less than 50% bad, start over */
if (ip_packets_seen > 4) {
ip_packets_bad_checksum = 0;
ip_packets_seen = 0;
}
/* Copy out the IP source address... */
memcpy(&from->sin_addr, &ip.ip_src, 4);
@@ -339,15 +348,21 @@ decode_udp_ip_header(struct interface_info *interface,
udp_packets_seen++;
if (usum && usum != sum) {
udp_packets_bad_checksum++;
if (udp_packets_seen > 4 &&
(udp_packets_seen / udp_packets_bad_checksum) < 2) {
log_info ("%d bad udp checksums in %d packets",
if (((udp_packets_seen > 4) && (udp_packets_bad_checksum != 0)) &&
((udp_packets_seen / udp_packets_bad_checksum) < 2)) {
log_info ("%u bad udp checksums in %u packets",
udp_packets_bad_checksum, udp_packets_seen);
udp_packets_seen = udp_packets_bad_checksum = 0;
}
return -1;
}
/* If at least 5 with less than 50% bad, start over */
if (udp_packets_seen > 4) {
udp_packets_bad_checksum = 0;
udp_packets_seen = 0;
}
/* Copy out the port... */
memcpy (&from -> sin_port, &udp.uh_sport, sizeof udp.uh_sport);