implement "not" keyword for inverting the address logic

This commit is contained in:
adam 1997-01-16 21:04:29 +00:00
parent b2be7a41d7
commit 3ea7d6ad8f
4 changed files with 29 additions and 14 deletions

View File

@ -22,16 +22,13 @@ list
add
.Op Ar number
.Ar action
.Op Ar log
.Op log
.Ar proto
from
.Ar src
to
.Ar dst
.Oo
via
.Ar name | ipno
.Oc
.Op via Ar name | ipno
.Op Ar options
.Sh DESCRIPTION
If used as shown in the first synopsis line, the
@ -117,8 +114,7 @@ Divert packets that match this rule to the divert socket bound to port
The search terminates.
.El
.Pp
When a packet matches a rule with the
.Ar log
When a packet matches a rule with the ``log''
keyword, a message will be printed on the console.
If the kernel was compiled with the
.Dv IP_FIREWALL_VERBOSE_LIMIT
@ -150,7 +146,8 @@ and
.Ar dst :
.Pp
.Bl -hang -offset flag
.It <address/mask> [ports]
.It Ar <address/mask>
.Op Ar ports
.El
.Pp
The
@ -168,10 +165,14 @@ 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
The sense of the match can be inverted by preceding an address with the
``not'' modifier, causing all other addresses to be matched instead. This
does not affect the selection of port numbers.
.Pp
With the TCP and UDP
.Em protocols ,
an optional
.Em port
optional
.Em ports
may be specified as:
.Pp
.Bl -hang -offset flag

View File

@ -162,7 +162,7 @@ show_ipfw(chain)
else
printf("%u", chain->fw_prot);
printf(" from ");
printf(" from %s", chain->fw_flg & IP_FW_F_INVSRC ? "not " : "");
adrt=ntohl(chain->fw_smsk.s_addr);
if (adrt==ULONG_MAX && do_resolv) {
@ -202,7 +202,7 @@ show_ipfw(chain)
}
}
printf(" to ");
printf(" to %s", chain->fw_flg & IP_FW_F_INVDST ? "not " : "");
adrt=ntohl(chain->fw_dmsk.s_addr);
if (adrt==ULONG_MAX && do_resolv) {
@ -685,6 +685,12 @@ add(ac,av)
if (ac && !strncmp(*av,"from",strlen(*av))) { av++; ac--; }
else show_usage("missing ``from''\n");
if (ac && !strncmp(*av,"not",strlen(*av))) {
rule.fw_flag |= IP_FW_F_INVSRC;
av++; ac--;
}
if (!ac) show_usage("Missing arguments\n");
fill_ip(&rule.fw_src, &rule.fw_smsk, &ac, &av);
if (ac && isdigit(**av)) {
@ -697,6 +703,10 @@ add(ac,av)
if (ac && !strncmp(*av,"to",strlen(*av))) { av++; ac--; }
else show_usage("missing ``to''\n");
if (ac && !strncmp(*av,"not",strlen(*av))) {
rule.fw_flag |= IP_FW_F_INVDST;
av++; ac--;
}
if (!ac) show_usage("Missing arguments\n");
fill_ip(&rule.fw_dst, &rule.fw_dmsk, &ac, &av);

View File

@ -320,11 +320,13 @@ ip_fw_chk(struct ip **pip, int hlen,
continue;
/* If src-addr doesn't match, not this rule. */
if ((src.s_addr & f->fw_smsk.s_addr) != f->fw_src.s_addr)
if ((f->fw_flg & IP_FW_F_INVSRC) != 0
^ (src.s_addr & f->fw_smsk.s_addr) != f->fw_src.s_addr)
continue;
/* If dest-addr doesn't match, not this rule. */
if ((dst.s_addr & f->fw_dmsk.s_addr) != f->fw_dst.s_addr)
if ((f->fw_flg & IP_FW_F_INVDST) != 0
^ (dst.s_addr & f->fw_dmsk.s_addr) != f->fw_dst.s_addr)
continue;
/* If a i/f name was specified, and we don't know */

View File

@ -64,6 +64,8 @@ struct ip_fw_chain {
/*
* Values for "flags" field .
*/
#define IP_FW_F_INVSRC 0x0001 /* Invert sense of src check */
#define IP_FW_F_INVDST 0x0002 /* Invert sense of dst check */
#define IP_FW_F_IN 0x0004 /* Inbound */
#define IP_FW_F_OUT 0x0008 /* Outbound */