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authorru <ru@FreeBSD.org>2000-04-05 14:27:34 +0000
committerru <ru@FreeBSD.org>2000-04-05 14:27:34 +0000
commit73d40971f4170b3b8996e5ac074646dc6696d52c (patch)
treea5c48f8da1a034503f0a56270a261736ace0d9bb /lib/libalias
parentd5c73e2c541564e6d4b323d9d40959e7b30f686d (diff)
downloadFreeBSD-src-73d40971f4170b3b8996e5ac074646dc6696d52c.zip
FreeBSD-src-73d40971f4170b3b8996e5ac074646dc6696d52c.tar.gz
- Remove unused includes.
- Minor spelling fixes. - Make IcmpAliasOut2() really work. Before this change: # natd -v -n PUB_IFACE -p 12345 -redirect_address 192.168.1.1 P.P.P.P natd[87923]: Aliasing to A.A.A.A, mtu 1500 bytes In [UDP] [UDP] X.X.X.X:49562 -> P.P.P.P:50000 aliased to [UDP] X.X.X.X:49562 -> 192.168.1.1:50000 Out [ICMP] [ICMP] 192.168.1.1 -> X.X.X.X 3(3) aliased to [ICMP] A.A.A.A -> X.X.X.X 3(3) # tcpdump -n -t -i PUB_IFACE host X.X.X.X and "(udp or icmp)" tcpdump: listening on PUB_IFACE X.X.X.X.49562 > P.P.P.P.50000: udp 3 A.A.A.A > X.X.X.X: icmp: A.A.A.A udp port 50000 unreachable After this change: # natd -v -n PUB_IFACE -p 12345 -redirect_address 192.168.1.1 P.P.P.P natd[89360]: Aliasing to A.A.A.A, mtu 1500 bytes In [UDP] [UDP] X.X.X.X:49563 -> P.P.P.P:50000 aliased to [UDP] X.X.X.X:49563 -> 192.168.1.1:50000 Out [ICMP] [ICMP] 192.168.1.1 -> X.X.X.X 3(3) aliased to [ICMP] P.P.P.P -> X.X.X.X 3(3) # tcpdump -n -t -i PUB_IFACE host X.X.X.X and "(udp or icmp)" tcpdump: listening on PUB_IFACE X.X.X.X.49563 > P.P.P.P.50000: udp 3 P.P.P.P > X.X.X.X: icmp: P.P.P.P udp port 50000 unreachable
Diffstat (limited to 'lib/libalias')
-rw-r--r--lib/libalias/alias.c120
1 files changed, 96 insertions, 24 deletions
diff --git a/lib/libalias/alias.c b/lib/libalias/alias.c
index 9c072df..d60791e 100644
--- a/lib/libalias/alias.c
+++ b/lib/libalias/alias.c
@@ -13,7 +13,7 @@
function calls, so other segments of the program need not know
about the underlying data structures. Alias_ftp.c contains
special code for modifying the ftp PORT command used to establish
- data connections, while alias_irc.c do the same for IRC
+ data connections, while alias_irc.c does the same for IRC
DCC. Alias_util.c contains a few utility routines.
This software is placed into the public domain with no restrictions
@@ -81,10 +81,6 @@
$FreeBSD$
*/
-#include <stdio.h>
-#include <unistd.h>
-
-#include <sys/param.h>
#include <sys/types.h>
#include <netinet/in_systm.h>
@@ -311,7 +307,7 @@ IcmpAliasIn2(struct ip *pip)
else if (ip->ip_p == IPPROTO_ICMP) {
if (ic2->icmp_type == ICMP_ECHO || ic2->icmp_type == ICMP_TSTAMP)
link = FindIcmpIn(ip->ip_dst, ip->ip_src, ic2->icmp_id);
- else
+ else
link = NULL;
} else
link = NULL;
@@ -379,8 +375,8 @@ fragment contained in ICMP data section */
2);
pip->ip_dst = original_address;
-/* Un-alias address of original IP packet and seqence number of
- embedded icmp datagram */
+/* Un-alias address of original IP packet and sequence number of
+ embedded ICMP datagram */
ip->ip_src = original_address;
ic2->icmp_id = original_id;
}
@@ -495,30 +491,106 @@ IcmpAliasOut2(struct ip *pip)
Alias outgoing ICMP error messages containing
IP header and first 64 bits of datagram.
*/
- struct in_addr alias_addr;
struct ip *ip;
- struct icmp *ic;
+ struct icmp *ic, *ic2;
+ struct udphdr *ud;
+ struct tcphdr *tc;
+ struct alias_link *link;
ic = (struct icmp *) ((char *) pip + (pip->ip_hl << 2));
ip = (struct ip *) ic->icmp_data;
- alias_addr = FindAliasAddress(ip->ip_src);
+ ud = (struct udphdr *) ((char *) ip + (ip->ip_hl <<2));
+ tc = (struct tcphdr *) ud;
+ ic2 = (struct icmp *) ud;
-/* Alias destination address in IP fragment */
- DifferentialChecksum(&ic->icmp_cksum,
- (u_short *) &alias_addr,
- (u_short *) &ip->ip_dst,
- 2);
- ip->ip_dst = alias_addr;
+ if (ip->ip_p == IPPROTO_UDP)
+ link = FindUdpTcpOut(ip->ip_dst, ip->ip_src,
+ ud->uh_dport, ud->uh_sport,
+ IPPROTO_UDP);
+ else if (ip->ip_p == IPPROTO_TCP)
+ link = FindUdpTcpOut(ip->ip_dst, ip->ip_src,
+ tc->th_dport, tc->th_sport,
+ IPPROTO_TCP);
+ else if (ip->ip_p == IPPROTO_ICMP) {
+ if (ic2->icmp_type == ICMP_ECHO || ic2->icmp_type == ICMP_TSTAMP)
+ link = FindIcmpOut(ip->ip_dst, ip->ip_src, ic2->icmp_id);
+ else
+ link = NULL;
+ } else
+ link = NULL;
-/* alias source address in IP header */
- DifferentialChecksum(&pip->ip_sum,
- (u_short *) &alias_addr,
- (u_short *) &pip->ip_src,
- 2);
- pip->ip_src = alias_addr;
+ if (link != NULL)
+ {
+ if (ip->ip_p == IPPROTO_UDP || ip->ip_p == IPPROTO_TCP)
+ {
+ u_short *sptr;
+ int accumulate;
+ struct in_addr alias_address;
+ u_short alias_port;
- return PKT_ALIAS_OK;
+ alias_address = GetAliasAddress(link);
+ alias_port = GetAliasPort(link);
+
+/* Adjust ICMP checksum */
+ sptr = (u_short *) &(ip->ip_dst);
+ accumulate = *sptr++;
+ accumulate += *sptr;
+ sptr = (u_short *) &alias_address;
+ accumulate -= *sptr++;
+ accumulate -= *sptr;
+ accumulate += ud->uh_dport;
+ accumulate -= alias_port;
+ ADJUST_CHECKSUM(accumulate, ic->icmp_cksum)
+
+/* Alias address in IP header */
+ DifferentialChecksum(&pip->ip_sum,
+ (u_short *) &alias_address,
+ (u_short *) &pip->ip_src,
+ 2);
+ pip->ip_src = alias_address;
+
+/* Alias address and port number of original IP packet
+fragment contained in ICMP data section */
+ ip->ip_dst = alias_address;
+ ud->uh_dport = alias_port;
+ }
+ else if (pip->ip_p == IPPROTO_ICMP)
+ {
+ u_short *sptr;
+ int accumulate;
+ struct in_addr alias_address;
+ u_short alias_id;
+
+ alias_address = GetAliasAddress(link);
+ alias_id = GetAliasPort(link);
+
+/* Adjust ICMP checksum */
+ sptr = (u_short *) &(ip->ip_dst);
+ accumulate = *sptr++;
+ accumulate += *sptr;
+ sptr = (u_short *) &alias_address;
+ accumulate -= *sptr++;
+ accumulate -= *sptr;
+ accumulate += ic2->icmp_id;
+ accumulate -= alias_id;
+ ADJUST_CHECKSUM(accumulate, ic->icmp_cksum)
+
+/* Alias address in IP header */
+ DifferentialChecksum(&pip->ip_sum,
+ (u_short *) &alias_address,
+ (u_short *) &pip->ip_src,
+ 2);
+ pip->ip_src = alias_address;
+
+/* Alias address of original IP packet and sequence number of
+ embedded ICMP datagram */
+ ip->ip_dst = alias_address;
+ ic2->icmp_id = alias_id;
+ }
+ return(PKT_ALIAS_OK);
+ }
+ return(PKT_ALIAS_IGNORED);
}
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