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Update to match kernel code.

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This commit is contained in:
Poul-Henning Kamp 1996-02-24 13:39:46 +00:00
parent 09bb5f7589
commit 72ee2a8b10
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=14233
3 changed files with 253 additions and 101 deletions
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11
sbin/ipfw/Makefile
View File

@ -1,16 +1,5 @@
PROG= ipfw
DPADD= ${LIBKVM}
LDADD= -lkvm
MAN8= ipfw.8
test: ipfw
./ipfw add reject tcp from any to any
./ipfw add 11 reject tcp from 1.2.3.4 to 5.6.7.8 established
./ipfw add 11 reject tcp from 1.2.3.4 to 5.6.7.8/24 in
./ipfw add 11 reject tcp from 1.2.3.4 to 5.6.7.8 in out
./ipfw add 11 reject tcp from 1.2.3.4 to 5.6.7.8 frag out
./ipfw add 11 reject tcp from 1.2.3.4 to 5.6.7.8 tcpf p,f,!a ipopt !ts
./ipfw add 12 count log udp from 1.2.3.4 to 5.6.7.8 123-125,234,245
.include <bsd.prog.mk>

227
sbin/ipfw/ipfw.8
View File

@ -1,25 +1,206 @@
.Dd November 16, 1994
.Dd February 24, 1996
.Dt IPFW 8 SMM
.Os FreeBSD
.Sh NAME
.Nm ipfw
.Nd controlling utility for IP firewall / IP accounting facilities.
.Nd controlling utility for IP firewall
.Sh SYNOPSIS
.Nm
.Oo
.Fl n
.Oc
.Ar entry_action chain_entry_pattern
.Nm ipfw
.Ar file
.Nm ipfw
flush
.Nm ipfw
zero
.Nm ipfw
delete
.Ar number
.Nm ipfw
.Oo
.Fl ans
.Fl aN
.Oc
list
.Nm ipfw
add
.Oo
.Ar number
.Oc
.Ar action
.Oo
log
.Oc
.Ar proto
from
.Ar src
to
.Ar dst
.Oo
via
.Ar name|ipno
.Oc
.Oo
.Ar options
.Oc
.Ar chain_action chain[s]_type
.\" ipfw [-n] <entry-action> <chain entry pattern>
.\" ipfw [-ans] <chain-action> <chain[s] type>
.Sh WARNING
This manual page is out of date!
.Sh DESCRIPTION
If used as shown in the first synopsis line, the
.Ar file
will be read line by line and applied as arguments to the
.Nm ipfw
command.
.Pp
The ipfw code works by going through the rule-list for each packet,
until a match is found.
All rules have two counters associated with them, a packet count and
a byte count.
These counters are updated when a packet matches the rule.
.Pp
The rules are ordered by a ``line-number'' that is used to order and
delete rules.
If a rule is added without a number, it is put at the end, just before
the terminal ``policy-rule'', and numbered 100 higher than the previous
rule.
.Pp
One rule is always present:
.Bd -literal -offset center
65535 deny all from any to any
.Ed
this is rule is the default policy, ie. don't allow anything at all.
Your job in setting up rules is to modify this policy to match your
needs.
.Pp
The following options are available:
.Bl -tag -width flag
.It Fl a
While listing, show counter values. This option is the only way to see
accounting records.
.It Fl N
Try to resolve addresses.
.El
.Pp
.Ar action :
.Bl -hang -offset flag -width 1234567890123456
.It Nm accept
Accept packets that match rule.
The search terminates.
.It Nm pass
same as accept.
.It Nm count
update counters for all packets that match rule.
The search continues with next rule.
.It Nm deny
Discard packets that match this rule.
The search terminates.
.It Nm reject
Discard packets that match this rule, try to send ICMP notice.
The search terminates.
.El
.Pp
When a packet matches a rule with the
.Nm log
keyword, a message will be printed on the console.
.Pp
.Ar proto :
.Bl -hang -offset flag -width 1234567890123456
.It Nm ip
All packets match.
.It Nm all
All packets match.
.It Nm tcp
Only TCP packets match.
.It Nm udp
Only UDP packets match.
.It Nm icmp
Only ICMP packets match.
.El
.Pp
.Ar src
and
.Ar dst :
.Bl -hang -offset flag -width 1234567890123456
.It Ar ipno
An ipnumber of the form 1.2.3.4.
Only this exact ip number match the rule.
.It Ar ipno/bits
An ipnumber with a mask width of the form 1.2.3.4/24.
In this case all ip numbers from 1.2.3.0 to 1.2.3.255 will match.
.It Ar ipno:mask
An ipnumber with a mask width of the form 1.2.3.4:255.255.240.0
In this case all ip numbers from 1.2.0.0 to 1.2.15.255 will match.
.El
.Pp
If ``via''
.Ar name
is specified, only packets received via or on their way out of an interface
matching
.Ar name
will match this rule.
.Pp
If ``via''
.Ar ipno
is specified, only packets received via or on their way out of an interface
having the address
.Ar ipno
will match this rule.
.Pp
.Ar options :
.Bl -hang -offset flag -width 1234567890123456
.It frag
Matches is the packet is a fragment and this is not the first fragment
of the datagram.
.It in
Matches if this packet was on the way in.
.It out
Matches if this packet was on the way out.
.It ipoptions Ar spec
Not yet documented. Look in the source: src/sys/netnet/ipfw.c.
.It established
Matches packets that do not have the SYN bit set.
TCP packets only.
.It setup
Matches packets that have the SYN bit set but no ACK bit.
TCP packets only.
.It tcpflags Ar spec
Not yet documented. Look in the source: src/sys/netnet/ipfw.c.
TCP packets only.
.El
.Sh CHECKLIST
Here are some important points to consider when designing your
rules:
.Bl -bullet -hang -offset flag -width 1234567890123456
.It
Remember that you filter both packets going in and out.
Most connections needs packets going in both directions.
.It
Remember to test very carefully.
It is a good idea to be near the console when doint this.
.It
Don't forget the loopback interface.
.El
.Sh FINE POINTS
There is one kind of packet that the firewall will always discard,
that is an IP fragment with a fragment offset of one.
This is a valid packet, but it only has one use, to try to circumvent
firewalls.
.Pp
If you are logged in over a network, loading the LKM version of
.Nm
is probably not as straightforward as you would think.
I recommend this command line:
.Bd -literal -offset center
modload /lkm/ipfw_mod.o && \e
ipfw add 32000 allow all from any to any
.Ed
Along the same lines, doing a
.Bd -literal -offset center
ipfw flush
.Ed
in similar surroundings is also a bad idea.
.Sh WARNING
This manual page is out of date beyond this point!
It is left here until some new text can be written.
.Sh OLD
In the first synopsis form,
.Nm
controls the firewall and accounting chains. In the second
@ -28,24 +209,6 @@ synopsis form,
sets the global firewall / accounting properties and
show the chain list's contents.
.Pp
The following options are available:
.Bl -tag -width flag
.It Fl a
While listing, show counter values. This option is the only way to see
accounting records. Works only with
.Fl s
.It Fl n
Do not resolve anything. When setting entries, do not try to resolve a
given address. When listing, display addresses in numeric form.
.It Fl s
Short listing form. By default, the listing format is compatible with
.Nm
input string format, so you can save listings to file and then reuse
them. With this option list format is much more short but incompatible
with the
.Nm
syntax.
.El
.Pp
These are the valid
.Ar entry_actions :
@ -323,3 +486,5 @@ The FreeBSD version is written completely by:
.Dl Ugen J.S.Antsilevich <ugen@FreeBSD.ORG>
.Pp
while the synopsis is partially compatible with the old one.
.Pp
This has all been extensively rearranged by Poul-Henning Kamp.

116
sbin/ipfw/ipfw.c
View File

@ -15,36 +15,27 @@
*
* NEW command line interface for IP firewall facility
*
* $Id: ipfw.c,v 1.19 1996/02/23 15:52:28 phk Exp $
* $Id: ipfw.c,v 1.20 1996/02/24 00:20:56 phk Exp $
*
*/
#include <stdio.h>
#include <ctype.h>
#include <err.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <paths.h>
#include <fcntl.h>
#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <netdb.h>
#include <kvm.h>
#include <sys/socket.h>
#include <limits.h>
#include <sys/queue.h>
#include <net/if.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_fw.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#define IPFIREWALL
#include <netinet/ip_fw.h>
#define MAXSTR 256
int lineno = -1;
char progname[MAXSTR]; /* Program name for errors */
char progname[BUFSIZ]; /* Program name for errors */
int s; /* main RAW socket */
int do_resolv=0; /* Would try to resolv all */
@ -229,6 +220,8 @@ show_ipfw(chain)
if (chain->fw_tcpf == IP_FW_TCPF_SYN &&
chain->fw_tcpnf == IP_FW_TCPF_ACK)
printf(" setup");
else if (chain->fw_tcpnf == IP_FW_TCPF_SYN && !chain->fw_tcpf)
printf(" established");
else if (chain->fw_tcpf || chain->fw_tcpnf) {
int _flg_printed = 0;
@ -252,38 +245,23 @@ show_ipfw(chain)
printf("\n");
}
struct nlist nlf[]={ { "_ip_fw_chain" } };
void
list(ac, av)
int ac;
char **av;
{
kvm_t *kd;
static char errb[_POSIX2_LINE_MAX];
struct ip_fw b;
struct ip_fw_chain *fcp,fc;
struct ip_fw *r;
struct ip_fw rules[1024];
int l,i;
if (!(kd=kvm_openfiles(NULL,NULL,NULL,O_RDONLY,errb))) {
fprintf(stderr,"%s: kvm_openfiles: %s\n",
progname,kvm_geterr(kd));
exit(1);
}
if (kvm_nlist(kd,nlf)<0 || nlf[0].n_type==0) {
fprintf(stderr,"%s: kvm_nlist: no namelist in %s\n",
progname,getbootfile());
exit(1);
}
kvm_read(kd,(u_long)nlf[0].n_value,&fcp,sizeof fcp);
printf("FireWall chain entries:\n");
while(fcp!=NULL) {
kvm_read(kd,(u_long)fcp,&fc,sizeof fc);
kvm_read(kd,(u_long)fc.rule,&b,sizeof b);
show_ipfw(&b);
fcp = fc.chain.le_next;
}
memset(rules,0,sizeof rules);
l = sizeof rules;
i = getsockopt(s, IPPROTO_IP, IP_FW_GET, rules, &l);
if (i < 0)
err(2,"getsockopt(IP_FW_GET)");
printf("FireWall chain entries: %d %d\n",l,i);
for (r=rules; l >= sizeof rules[0]; r++, l-=sizeof rules[0])
show_ipfw(r);
}
void
@ -513,9 +491,6 @@ add(ac,av)
rule.fw_flg |= IP_FW_F_PRN; av++; ac--;
}
/* [protocol] */
if (ac && !strncmp(*av,"protocol",strlen(*av))) { av++; ac--; }
/* protocol */
if (ac && !strncmp(*av,"ip",strlen(*av))) {
rule.fw_flg |= IP_FW_F_ALL; av++; ac--;
@ -557,6 +532,23 @@ add(ac,av)
av++; ac--;
}
if (ac && !strncmp(*av,"via",strlen(*av))) {
av++; ac--;
if (!isdigit(**av)) {
char *q;
strcpy(rule.fw_via_name, *av);
for (q = rule.fw_via_name; *q && !isdigit(*q); q++)
continue;
rule.fw_via_unit = atoi(q);
*q = '\0';
rule.fw_flg |= IP_FW_F_IFNAME;
} else if (inet_aton(*av,&rule.fw_via_ip) == INADDR_NONE) {
show_usage("bad IP# after via\n");
}
av++; ac--;
}
while (ac) {
if (!strncmp(*av,"frag",strlen(*av))) {
rule.fw_flg |= IP_FW_F_FRAG; av++; ac--; continue;
@ -567,21 +559,27 @@ add(ac,av)
if (!strncmp(*av,"out",strlen(*av))) {
rule.fw_flg |= IP_FW_F_OUT; av++; ac--; continue;
}
if (!strncmp(*av,"established",strlen(*av))) {
rule.fw_tcpf |= IP_FW_TCPF_SYN;
rule.fw_tcpnf |= IP_FW_TCPF_ACK;
av++; ac--; continue;
}
if (ac > 1 && !strncmp(*av,"tcpflags",strlen(*av))) {
av++; ac--;
fill_tcpflag(&rule.fw_tcpf, &rule.fw_tcpnf, av);
av++; ac--; continue;
}
if (ac > 1 && !strncmp(*av,"ipoptions",strlen(*av))) {
av++; ac--;
fill_ipopt(&rule.fw_ipopt, &rule.fw_ipnopt, av);
av++; ac--; continue;
}
if ((rule.fw_flg & IP_FW_F_KIND) == IP_FW_F_TCP) {
if (!strncmp(*av,"established",strlen(*av))) {
rule.fw_tcpnf |= IP_FW_TCPF_SYN;
av++; ac--; continue;
}
if (!strncmp(*av,"setup",strlen(*av))) {
rule.fw_tcpf |= IP_FW_TCPF_SYN;
rule.fw_tcpnf |= IP_FW_TCPF_ACK;
av++; ac--; continue;
}
if (ac > 1 && !strncmp(*av,"tcpflags",strlen(*av))) {
av++; ac--;
fill_tcpflag(&rule.fw_tcpf, &rule.fw_tcpnf, av);
av++; ac--; continue;
}
}
printf("%d %s\n",ac,*av);
show_usage("Unknown argument\n");
}
@ -606,12 +604,12 @@ ipfw_main(ac,av)
show_usage(NULL);
}
while ((ch = getopt(ac, av ,"an")) != EOF)
while ((ch = getopt(ac, av ,"aN")) != EOF)
switch(ch) {
case 'a':
do_acct=1;
break;
case 'n':
case 'N':
do_resolv=1;
break;
case '?':
@ -656,7 +654,7 @@ main(ac, av)
char **av;
{
#define MAX_ARGS 32
char buf[_POSIX_ARG_MAX];
char buf[BUFSIZ];
char *args[MAX_ARGS];
char linename[10];
int i;
@ -676,7 +674,7 @@ main(ac, av)
if (av[1] && !access(av[1], R_OK)) {
lineno = 0;
f = fopen(av[1], "r");
while (fgets(buf, _POSIX_ARG_MAX, f)) {
while (fgets(buf, BUFSIZ, f)) {
if (buf[strlen(buf)-1]=='\n')
buf[strlen(buf)-1] = 0;