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Code Issues Releases Activity

- Remove unused includes.

Browse Source 
- 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
This commit is contained in:
Ruslan Ermilov 2000-04-05 14:27:34 +00:00
parent 79eef4b611
commit 680c8244a9
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=59047
2 changed files with 192 additions and 48 deletions
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120
lib/libalias/alias.c
View File

@ -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);
}

120
sys/netinet/libalias/alias.c
View File

@ -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);
}