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authorMurray Stokely <murray@FreeBSD.org>2002-02-19 11:04:34 +0000
committerMurray Stokely <murray@FreeBSD.org>2002-02-19 11:04:34 +0000
commitce99b771f886a2c842db7aa803c9a5a5918f42c8 (patch)
tree229464d9b3244ab78e2784c9a0a1f78de317089a /contrib/isc-dhcp/common/packet.c
parent7657fb140fbd218ea326d55bd3c43c4077f03d9a (diff)
downloadsrc-ce99b771f886a2c842db7aa803c9a5a5918f42c8.tar.gz
src-ce99b771f886a2c842db7aa803c9a5a5918f42c8.zip
Import ISC DHCP 3.0.1 RC6 client.
Notes
Notes: svn path=/vendor/isc-dhcp/dist/; revision=90908
Diffstat (limited to 'contrib/isc-dhcp/common/packet.c')
-rw-r--r--contrib/isc-dhcp/common/packet.c121
1 files changed, 74 insertions, 47 deletions
diff --git a/contrib/isc-dhcp/common/packet.c b/contrib/isc-dhcp/common/packet.c
index 6a15fcf1e4df..8fe389412922 100644
--- a/contrib/isc-dhcp/common/packet.c
+++ b/contrib/isc-dhcp/common/packet.c
@@ -3,7 +3,7 @@
Packet assembly code, originally contributed by Archie Cobbs. */
/*
- * Copyright (c) 1995, 1996, 1999 The Internet Software Consortium.
+ * Copyright (c) 1996-2001 Internet Software Consortium.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -33,16 +33,16 @@
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
- * This software has been written for the Internet Software Consortium
- * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
- * Enterprises. To learn more about the Internet Software Consortium,
- * see ``http://www.vix.com/isc''. To learn more about Vixie
- * Enterprises, see ``http://www.vix.com''.
+ * This code was originally contributed by Archie Cobbs, and is still
+ * very similar to that contribution, although the packet checksum code
+ * has been hacked significantly with the help of quite a few ISC DHCP
+ * users, without whose gracious and thorough help the checksum code would
+ * still be disabled.
*/
#ifndef lint
static char copyright[] =
-"$Id: packet.c,v 1.18.2.6 1999/06/10 00:58:16 mellon Exp $ Copyright (c) 1996 The Internet Software Consortium. All rights reserved.\n";
+"$Id: packet.c,v 1.40.2.1 2001/05/31 19:28:51 mellon Exp $ Copyright (c) 1996-2001 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
@@ -50,25 +50,26 @@ static char copyright[] =
#if defined (PACKET_ASSEMBLY) || defined (PACKET_DECODING)
#include "includes/netinet/ip.h"
#include "includes/netinet/udp.h"
+#include "includes/netinet/if_ether.h"
#endif /* PACKET_ASSEMBLY || PACKET_DECODING */
/* Compute the easy part of the checksum on a range of bytes. */
u_int32_t checksum (buf, nbytes, sum)
unsigned char *buf;
- int nbytes;
+ unsigned nbytes;
u_int32_t sum;
{
- int i;
+ unsigned i;
#ifdef DEBUG_CHECKSUM
- debug ("checksum (%x %d %x)", buf, nbytes, sum);
+ log_debug ("checksum (%x %d %x)", buf, nbytes, sum);
#endif
/* Checksum all the pairs of bytes first... */
- for (i = 0; i < (nbytes & ~1); i += 2) {
+ for (i = 0; i < (nbytes & ~1U); i += 2) {
#ifdef DEBUG_CHECKSUM_VERBOSE
- debug ("sum = %x", sum);
+ log_debug ("sum = %x", sum);
#endif
sum += (u_int16_t) ntohs(*((u_int16_t *)(buf + i)));
/* Add carry. */
@@ -80,7 +81,7 @@ u_int32_t checksum (buf, nbytes, sum)
byte order is big-endian, so the remaining byte is the high byte. */
if (i < nbytes) {
#ifdef DEBUG_CHECKSUM_VERBOSE
- debug ("sum = %x", sum);
+ log_debug ("sum = %x", sum);
#endif
sum += buf [i] << 8;
/* Add carry. */
@@ -91,41 +92,43 @@ u_int32_t checksum (buf, nbytes, sum)
return sum;
}
-/* Finish computing the sum, and then put it into network byte order. */
+/* Finish computing the checksum, and then put it into network byte order. */
u_int32_t wrapsum (sum)
u_int32_t sum;
{
#ifdef DEBUG_CHECKSUM
- debug ("wrapsum (%x)", sum);
+ log_debug ("wrapsum (%x)", sum);
#endif
sum = ~sum & 0xFFFF;
#ifdef DEBUG_CHECKSUM_VERBOSE
- debug ("sum = %x", sum);
+ log_debug ("sum = %x", sum);
#endif
#ifdef DEBUG_CHECKSUM
- debug ("wrapsum returns %x", htons (sum));
+ log_debug ("wrapsum returns %x", htons (sum));
#endif
return htons(sum);
}
#ifdef PACKET_ASSEMBLY
-/* Assemble an hardware header... */
-/* XXX currently only supports ethernet; doesn't check for other types. */
-
void assemble_hw_header (interface, buf, bufix, to)
struct interface_info *interface;
unsigned char *buf;
- int *bufix;
+ unsigned *bufix;
struct hardware *to;
{
#if defined (HAVE_TR_SUPPORT)
- if (interface -> hw_address.htype == HTYPE_IEEE802)
+ if (interface -> hw_address.hbuf [0] == HTYPE_IEEE802)
assemble_tr_header (interface, buf, bufix, to);
else
#endif
+#if defined (DEC_FDDI)
+ if (interface -> hw_address.hbuf [0] == HTYPE_FDDI)
+ assemble_fddi_header (interface, buf, bufix, to);
+ else
+#endif
assemble_ethernet_header (interface, buf, bufix, to);
}
@@ -136,19 +139,19 @@ void assemble_udp_ip_header (interface, buf, bufix,
from, to, port, data, len)
struct interface_info *interface;
unsigned char *buf;
- int *bufix;
+ unsigned *bufix;
u_int32_t from;
u_int32_t to;
- unsigned int port;
+ u_int32_t port;
unsigned char *data;
- int len;
+ unsigned len;
{
struct ip ip;
struct udphdr udp;
/* Fill out the IP header */
- ip.ip_v = 4;
- ip.ip_hl = 5;
+ IP_V_SET (&ip, 4);
+ IP_HL_SET (&ip, 20);
ip.ip_tos = IPTOS_LOWDELAY;
ip.ip_len = htons(sizeof(ip) + sizeof(udp) + len);
ip.ip_id = 0;
@@ -193,18 +196,24 @@ void assemble_udp_ip_header (interface, buf, bufix,
#ifdef PACKET_DECODING
/* Decode a hardware header... */
+/* XXX currently only supports ethernet; doesn't check for other types. */
ssize_t decode_hw_header (interface, buf, bufix, from)
struct interface_info *interface;
unsigned char *buf;
- int bufix;
+ unsigned bufix;
struct hardware *from;
{
#if defined (HAVE_TR_SUPPORT)
- if (interface -> hw_address.htype == HTYPE_IEEE802)
+ if (interface -> hw_address.hbuf [0] == HTYPE_IEEE802)
return decode_tr_header (interface, buf, bufix, from);
else
#endif
+#if defined (DEC_FDDI)
+ if (interface -> hw_address.hbuf [0] == HTYPE_FDDI)
+ return decode_fddi_header (interface, buf, bufix, from);
+ else
+#endif
return decode_ethernet_header (interface, buf, bufix, from);
}
@@ -213,10 +222,10 @@ ssize_t decode_hw_header (interface, buf, bufix, from)
ssize_t decode_udp_ip_header (interface, buf, bufix, from, data, buflen)
struct interface_info *interface;
unsigned char *buf;
- int bufix;
+ unsigned bufix;
struct sockaddr_in *from;
unsigned char *data;
- int buflen;
+ unsigned buflen;
{
struct ip *ip;
struct udphdr *udp;
@@ -228,7 +237,9 @@ ssize_t decode_udp_ip_header (interface, buf, bufix, from, data, buflen)
static int udp_packets_bad_checksum;
static int udp_packets_length_checked;
static int udp_packets_length_overflow;
- int len;
+ unsigned len;
+ unsigned ulen;
+ int ignore = 0;
ip = (struct ip *)(buf + bufix);
udp = (struct udphdr *)(buf + bufix + ip_len);
@@ -243,23 +254,34 @@ ssize_t decode_udp_ip_header (interface, buf, bufix, from, data, buflen)
return -1;
#endif /* USERLAND_FILTER */
+ ulen = ntohs (udp -> uh_ulen);
+ if (ulen < sizeof *udp ||
+ ((unsigned char *)udp) + ulen > buf + bufix + buflen) {
+ log_info ("bogus UDP packet length: %d", ulen);
+ return -1;
+ }
+
/* Check the IP header checksum - it should be zero. */
++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) {
- note ("%d bad IP checksums seen in %d packets",
- ip_packets_bad_checksum, ip_packets_seen);
+ log_info ("%d bad IP checksums seen in %d packets",
+ ip_packets_bad_checksum, ip_packets_seen);
ip_packets_seen = ip_packets_bad_checksum = 0;
}
return -1;
}
/* Check the IP packet length. */
- if (ntohs (ip -> ip_len) != buflen)
- debug ("ip length %d disagrees with bytes received %d.",
- ntohs (ip -> ip_len), buflen);
+ if (ntohs (ip -> ip_len) != buflen) {
+ if ((ntohs (ip -> ip_len + 2) & ~1) == buflen)
+ ignore = 1;
+ else
+ log_debug ("ip length %d disagrees with bytes received %d.",
+ ntohs (ip -> ip_len), buflen);
+ }
/* Copy out the IP source address... */
memcpy (&from -> sin_addr, &ip -> ip_src, 4);
@@ -270,23 +292,29 @@ ssize_t decode_udp_ip_header (interface, buf, bufix, from, data, buflen)
if (!data) {
data = buf + bufix + ip_len + sizeof *udp;
- len = ntohs (udp -> uh_ulen) - sizeof *udp;
+ len = ulen - sizeof *udp;
++udp_packets_length_checked;
if (len + data > buf + bufix + buflen) {
++udp_packets_length_overflow;
if (udp_packets_length_checked > 4 &&
(udp_packets_length_checked /
udp_packets_length_overflow) < 2) {
- note ("%d udp packets in %d too long - dropped",
- udp_packets_length_overflow,
- udp_packets_length_checked);
+ log_info ("%d udp packets in %d too long - dropped",
+ udp_packets_length_overflow,
+ udp_packets_length_checked);
udp_packets_length_overflow =
udp_packets_length_checked = 0;
}
return -1;
}
- if (len + data != buf + bufix + buflen)
- debug ("accepting packet with data after udp payload.");
+ if (len + data < buf + bufix + buflen &&
+ len + data != buf + bufix + buflen && !ignore)
+ log_debug ("accepting packet with data after udp payload.");
+ if (len + data > buf + bufix + buflen) {
+ log_debug ("dropping packet with bogus uh_ulen %ld",
+ (long)(len + sizeof *udp));
+ return -1;
+ }
}
usum = udp -> uh_sum;
@@ -298,16 +326,15 @@ ssize_t decode_udp_ip_header (interface, buf, bufix, from, data, buflen)
&ip -> ip_src,
2 * sizeof ip -> ip_src,
IPPROTO_UDP +
- (u_int32_t)
- ntohs (udp -> uh_ulen)))));
+ (u_int32_t)ulen))));
udp_packets_seen++;
if (usum && usum != sum) {
udp_packets_bad_checksum++;
if (udp_packets_seen > 4 &&
(udp_packets_seen / udp_packets_bad_checksum) < 2) {
- note ("%d bad udp checksums in %d packets",
- udp_packets_bad_checksum, udp_packets_seen);
+ log_info ("%d bad udp checksums in %d packets",
+ udp_packets_bad_checksum, udp_packets_seen);
udp_packets_seen = udp_packets_bad_checksum = 0;
}
return -1;