freebsd-nq/sbin/ipfw/ipfw.c
Poul-Henning Kamp 6cece43912 recognize "allow", "accept" and "pass"
add new feature for "established"
1996-04-03 13:49:10 +00:00

708 lines
15 KiB
C

/*
* Copyright (c) 1996 Poul-Henning Kamp
* Copyright (c) 1994 Ugen J.S.Antsilevich
* Idea and grammar partially left from:
* Copyright (c) 1993 Daniel Boulet
*
* Redistribution and use in source forms, with and without modification,
* are permitted provided that this entire comment appears intact.
*
* Redistribution in binary form may occur without any restrictions.
* Obviously, it would be nice if you gave credit where credit is due
* but requiring it would be too onerous.
*
* This software is provided ``AS IS'' without any warranties of any kind.
*
* NEW command line interface for IP firewall facility
*
* $Id: ipfw.c,v 1.22 1996/04/02 11:43:28 phk Exp $
*
*/
#include <stdio.h>
#include <ctype.h>
#include <err.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <netdb.h>
#include <limits.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip_fw.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
int lineno = -1;
char progname[BUFSIZ]; /* Program name for errors */
int s; /* main RAW socket */
int do_resolv=0; /* Would try to resolv all */
int do_acct=0; /* Show packet/byte count */
int
mask_bits(m_ad)
struct in_addr m_ad;
{
int h_fnd=0,h_num=0,i;
u_long mask;
mask=ntohl(m_ad.s_addr);
for (i=0;i<sizeof(u_long)*CHAR_BIT;i++) {
if (mask & 1L) {
h_fnd=1;
h_num++;
} else {
if (h_fnd)
return -1;
}
mask=mask>>1;
}
return h_num;
}
void
show_ipfw(chain)
struct ip_fw *chain;
{
char *comma;
u_long adrt;
struct hostent *he;
int i,mb;
printf("%05u ", chain->fw_number);
if (do_acct)
printf("%10lu %10lu ",chain->fw_pcnt,chain->fw_bcnt);
if (chain->fw_flg & IP_FW_F_ACCEPT)
printf("allow");
else if (chain->fw_flg & IP_FW_F_ICMPRPL)
printf("reject");
else if (chain->fw_flg & IP_FW_F_COUNT)
printf("count");
else
printf("deny");
if (chain->fw_flg & IP_FW_F_PRN)
printf(" log");
switch (chain->fw_flg & IP_FW_F_KIND) {
case IP_FW_F_ICMP:
printf(" icmp ");
break;
case IP_FW_F_TCP:
printf(" tcp ");
break;
case IP_FW_F_UDP:
printf(" udp ");
break;
case IP_FW_F_ALL:
printf(" all ");
break;
default:
break;
}
printf("from ");
adrt=ntohl(chain->fw_smsk.s_addr);
if (adrt==ULONG_MAX && do_resolv) {
adrt=(chain->fw_src.s_addr);
he=gethostbyaddr((char *)&adrt,sizeof(u_long),AF_INET);
if (he==NULL) {
printf(inet_ntoa(chain->fw_src));
} else
printf("%s",he->h_name);
} else {
if (adrt!=ULONG_MAX) {
mb=mask_bits(chain->fw_smsk);
if (mb == 0) {
printf("any");
} else {
if (mb > 0) {
printf(inet_ntoa(chain->fw_src));
printf("/%d",mb);
} else {
printf(inet_ntoa(chain->fw_src));
printf(":");
printf(inet_ntoa(chain->fw_smsk));
}
}
} else
printf(inet_ntoa(chain->fw_src));
}
comma = " ";
for (i=0;i<chain->fw_nsp; i++ ) {
printf("%s%d",comma,chain->fw_pts[i]);
if (i==0 && (chain->fw_flg & IP_FW_F_SRNG))
comma = "-";
else
comma = ",";
}
printf(" to ");
adrt=ntohl(chain->fw_dmsk.s_addr);
if (adrt==ULONG_MAX && do_resolv) {
adrt=(chain->fw_dst.s_addr);
he=gethostbyaddr((char *)&adrt,sizeof(u_long),AF_INET);
if (he==NULL) {
printf(inet_ntoa(chain->fw_dst));
} else
printf("%s",he->h_name);
} else {
if (adrt!=ULONG_MAX) {
mb=mask_bits(chain->fw_dmsk);
if (mb == 0) {
printf("any");
} else {
if (mb > 0) {
printf(inet_ntoa(chain->fw_dst));
printf("/%d",mb);
} else {
printf(inet_ntoa(chain->fw_dst));
printf(":");
printf(inet_ntoa(chain->fw_dmsk));
}
}
} else
printf(inet_ntoa(chain->fw_dst));
}
comma = " ";
for (i=0;i<chain->fw_ndp;i++) {
printf("%s%d",comma,chain->fw_pts[chain->fw_nsp+i]);
if (i==0 && (chain->fw_flg & IP_FW_F_DRNG))
comma = "-";
else
comma = ",";
}
if ((chain->fw_flg & IP_FW_F_IN) && (chain->fw_flg & IP_FW_F_OUT))
;
else if (chain->fw_flg & IP_FW_F_IN)
printf(" in ");
else if (chain->fw_flg & IP_FW_F_OUT)
printf(" out ");
if (chain->fw_flg&IP_FW_F_IFNAME && chain->fw_via_name[0]) {
char ifnb[FW_IFNLEN+1];
printf(" via ");
strncpy(ifnb,chain->fw_via_name,FW_IFNLEN);
ifnb[FW_IFNLEN]='\0';
printf("%s%d",ifnb,chain->fw_via_unit);
} else if (chain->fw_via_ip.s_addr) {
printf(" via ");
printf(inet_ntoa(chain->fw_via_ip));
}
if (chain->fw_flg & IP_FW_F_FRAG)
printf("frag ");
if (chain->fw_ipopt || chain->fw_ipnopt) {
int _opt_printed = 0;
#define PRINTOPT(x) {if (_opt_printed) printf(",");\
printf(x); _opt_printed = 1;}
printf(" ipopt ");
if (chain->fw_ipopt & IP_FW_IPOPT_SSRR) PRINTOPT("ssrr");
if (chain->fw_ipnopt & IP_FW_IPOPT_SSRR) PRINTOPT("!ssrr");
if (chain->fw_ipopt & IP_FW_IPOPT_LSRR) PRINTOPT("lsrr");
if (chain->fw_ipnopt & IP_FW_IPOPT_LSRR) PRINTOPT("!lsrr");
if (chain->fw_ipopt & IP_FW_IPOPT_RR) PRINTOPT("rr");
if (chain->fw_ipnopt & IP_FW_IPOPT_RR) PRINTOPT("!rr");
if (chain->fw_ipopt & IP_FW_IPOPT_TS) PRINTOPT("ts");
if (chain->fw_ipnopt & IP_FW_IPOPT_TS) PRINTOPT("!ts");
}
if (chain->fw_tcpf & IP_FW_TCPF_ESTAB)
printf(" established");
else if (chain->fw_tcpf == IP_FW_TCPF_SYN &&
chain->fw_tcpnf == IP_FW_TCPF_ACK)
printf(" setup");
else if (chain->fw_tcpf || chain->fw_tcpnf) {
int _flg_printed = 0;
#define PRINTFLG(x) {if (_flg_printed) printf(",");\
printf(x); _flg_printed = 1;}
printf(" tcpflg ");
if (chain->fw_tcpf & IP_FW_TCPF_FIN) PRINTFLG("fin");
if (chain->fw_tcpnf & IP_FW_TCPF_FIN) PRINTFLG("!fin");
if (chain->fw_tcpf & IP_FW_TCPF_SYN) PRINTFLG("syn");
if (chain->fw_tcpnf & IP_FW_TCPF_SYN) PRINTFLG("!syn");
if (chain->fw_tcpf & IP_FW_TCPF_RST) PRINTFLG("rst");
if (chain->fw_tcpnf & IP_FW_TCPF_RST) PRINTFLG("!rst");
if (chain->fw_tcpf & IP_FW_TCPF_PSH) PRINTFLG("psh");
if (chain->fw_tcpnf & IP_FW_TCPF_PSH) PRINTFLG("!psh");
if (chain->fw_tcpf & IP_FW_TCPF_ACK) PRINTFLG("ack");
if (chain->fw_tcpnf & IP_FW_TCPF_ACK) PRINTFLG("!ack");
if (chain->fw_tcpf & IP_FW_TCPF_URG) PRINTFLG("urg");
if (chain->fw_tcpnf & IP_FW_TCPF_URG) PRINTFLG("!urg");
}
printf("\n");
}
void
list(ac, av)
int ac;
char **av;
{
struct ip_fw *r;
struct ip_fw rules[1024];
int l,i;
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
show_usage(str)
char *str;
{
if (str)
fprintf(stderr,"%s: ERROR - %s\n",progname,str);
else
fprintf(stderr,"%s: ERROR - bad arguments\n",progname);
fprintf(stderr,
"Usage:\n"
"\t%s [options]\n"
"\t\tflush\n"
"\t\tadd [number] rule\n"
"\t\tdelete number\n"
"\t\tlist [number]\n"
"\t\tzero [number]\n"
"\trule:\taction proto src dst extras...\n"
"\t\taction: {allow|deny|reject|count} [log]\n"
"\t\tproto: {ip|tcp|udp|icmp}}\n"
"\t\tsrc: {any|ip[{/bits|:mask}]} [{port|port-port},...]\n"
"\t\tdst: {any|ip[{/bits|:mask}]} [{port|port-port},...]\n"
"\textras:\n"
"\t\tfragment\n"
"\t\t{in|out|inout}\n"
"\t\tvia {ifname|ip}\n"
"\t\ttcpflags [!]{syn|fin|rst|ack|psh},...\n"
, progname
);
fprintf(stderr,"See man %s(8) for proper usage.\n",progname);
exit (1);
}
void
fill_ip(ipno, mask, acp, avp)
struct in_addr *ipno, *mask;
int *acp;
char ***avp;
{
int ac = *acp;
char **av = *avp;
char *p = 0, md = 0;
if (ac && !strncmp(*av,"any",strlen(*av))) {
ipno->s_addr = mask->s_addr = 0; av++; ac--;
} else {
p = strchr(*av, '/');
if (!p)
p = strchr(*av, ':');
if (p) {
md = *p;
*p++ = '\0';
}
if (!inet_aton(*av,ipno))
show_usage("ip number\n");
if (md == ':' && !inet_aton(p,mask))
show_usage("ip number\n");
else if (md == '/')
mask->s_addr = htonl(0xffffffff << (32 - atoi(p)));
else
mask->s_addr = htonl(0xffffffff);
av++;
ac--;
}
*acp = ac;
*avp = av;
}
int
fill_port(cnt, ptr, off, av)
u_short *cnt, *ptr, off;
char **av;
{
char *s, sc = 0;
int i = 0;
s = strchr(*av,'-');
if (s) {
sc = *s;
*s++ = '\0';
ptr[off+*cnt] = atoi(*av);
(*cnt)++;
*av = s;
s = strchr(*av,',');
if (s) {
sc = *s;
*s++ = '\0';
} else
sc = '\0';
ptr[off+*cnt] = atoi(*av);
(*cnt)++;
if (sc && sc != ',') show_usage("Expected comma\n");
*av = s;
sc = 0;
i = 1;
}
while (*av != NULL) {
s = strchr(*av,',');
if (s) {
sc = *s;
*s++ = '\0';
} else
sc = '\0';
ptr[off+*cnt] = atoi(*av);
(*cnt)++;
if (!sc)
break;
if (sc != ',') show_usage("Expected comma\n");
*av = s;
}
return i;
}
void
fill_tcpflag(set, reset, vp)
u_char *set, *reset;
char **vp;
{
char *p = *vp,*q;
u_char *d;
while (p && *p) {
if (*p == '!') {
p++;
d = reset;
} else {
d = set;
}
q = strchr(p, ',');
if (q)
*q++ = '\0';
if (!strncmp(p,"syn",strlen(p))) *d |= IP_FW_TCPF_SYN;
if (!strncmp(p,"fin",strlen(p))) *d |= IP_FW_TCPF_FIN;
if (!strncmp(p,"ack",strlen(p))) *d |= IP_FW_TCPF_ACK;
if (!strncmp(p,"psh",strlen(p))) *d |= IP_FW_TCPF_PSH;
if (!strncmp(p,"rst",strlen(p))) *d |= IP_FW_TCPF_RST;
p = q;
}
}
void
fill_ipopt(set, reset, vp)
u_char *set, *reset;
char **vp;
{
char *p = *vp,*q;
u_char *d;
while (p && *p) {
if (*p == '!') {
p++;
d = reset;
} else {
d = set;
}
q = strchr(p, ',');
if (q)
*q++ = '\0';
if (!strncmp(p,"ssrr",strlen(p))) *d |= IP_FW_IPOPT_SSRR;
if (!strncmp(p,"lsrr",strlen(p))) *d |= IP_FW_IPOPT_LSRR;
if (!strncmp(p,"rr",strlen(p))) *d |= IP_FW_IPOPT_RR;
if (!strncmp(p,"ts",strlen(p))) *d |= IP_FW_IPOPT_TS;
p = q;
}
}
void
delete(ac,av)
int ac;
char **av;
{
struct ip_fw rule;
int i;
memset(&rule, 0, sizeof rule);
av++; ac--;
/* Rule number */
if (ac && isdigit(**av)) {
rule.fw_number = atoi(*av); av++; ac--;
}
i = setsockopt(s, IPPROTO_IP, IP_FW_DEL, &rule, sizeof rule);
if (i)
err(1,"setsockopt(Add)");
}
void
add(ac,av)
int ac;
char **av;
{
struct ip_fw rule;
int i;
memset(&rule, 0, sizeof rule);
av++; ac--;
/* Rule number */
if (ac && isdigit(**av)) {
rule.fw_number = atoi(*av); av++; ac--;
}
/* Action */
if (ac && !strncmp(*av,"accept",strlen(*av))) {
rule.fw_flg |= IP_FW_F_ACCEPT; av++; ac--;
} else if (ac && !strncmp(*av,"allow",strlen(*av))) {
rule.fw_flg |= IP_FW_F_ACCEPT; av++; ac--;
} else if (ac && !strncmp(*av,"pass",strlen(*av))) {
rule.fw_flg |= IP_FW_F_ACCEPT; av++; ac--;
} else if (ac && !strncmp(*av,"count",strlen(*av))) {
rule.fw_flg |= IP_FW_F_COUNT; av++; ac--;
} else if (ac && !strncmp(*av,"deny",strlen(*av))) {
av++; ac--;
} else if (ac && !strncmp(*av,"reject",strlen(*av))) {
rule.fw_flg |= IP_FW_F_ICMPRPL; av++; ac--;
} else {
show_usage("missing action\n");
}
/* [log] */
if (ac && !strncmp(*av,"log",strlen(*av))) {
rule.fw_flg |= IP_FW_F_PRN; av++; ac--;
}
/* protocol */
if (ac && !strncmp(*av,"ip",strlen(*av))) {
rule.fw_flg |= IP_FW_F_ALL; av++; ac--;
} else if (ac && !strncmp(*av,"all",strlen(*av))) {
rule.fw_flg |= IP_FW_F_ALL; av++; ac--;
} else if (ac && !strncmp(*av,"tcp",strlen(*av))) {
rule.fw_flg |= IP_FW_F_TCP; av++; ac--;
} else if (ac && !strncmp(*av,"udp",strlen(*av))) {
rule.fw_flg |= IP_FW_F_UDP; av++; ac--;
} else if (ac && !strncmp(*av,"icmp",strlen(*av))) {
rule.fw_flg |= IP_FW_F_ICMP; av++; ac--;
} else {
show_usage("missing protocol\n");
}
/* from */
if (ac && !strncmp(*av,"from",strlen(*av))) { av++; ac--; }
else show_usage("missing ``from''\n");
fill_ip(&rule.fw_src, &rule.fw_smsk, &ac, &av);
if (ac && isdigit(**av)) {
if (fill_port(&rule.fw_nsp, &rule.fw_pts, 0, av))
rule.fw_flg |= IP_FW_F_SRNG;
av++; ac--;
}
/* to */
if (ac && !strncmp(*av,"to",strlen(*av))) { av++; ac--; }
else show_usage("missing ``to''\n");
if (!ac) show_usage("Missing arguments\n");
fill_ip(&rule.fw_dst, &rule.fw_dmsk, &ac, &av);
if (ac && isdigit(**av)) {
if (fill_port(&rule.fw_ndp, &rule.fw_pts, rule.fw_nsp, av))
rule.fw_flg |= IP_FW_F_DRNG;
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;
}
if (!strncmp(*av,"in",strlen(*av))) {
rule.fw_flg |= IP_FW_F_IN; av++; ac--; continue;
}
if (!strncmp(*av,"out",strlen(*av))) {
rule.fw_flg |= IP_FW_F_OUT; 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_tcpf |= IP_FW_TCPF_ESTAB;
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");
}
show_ipfw(&rule);
i = setsockopt(s, IPPROTO_IP, IP_FW_ADD, &rule, sizeof rule);
if (i)
err(1,"setsockopt(Delete)");
}
int
ipfw_main(ac,av)
int ac;
char **av;
{
char ch;
extern int optind;
if ( ac == 1 ) {
show_usage(NULL);
}
while ((ch = getopt(ac, av ,"aN")) != EOF)
switch(ch) {
case 'a':
do_acct=1;
break;
case 'N':
do_resolv=1;
break;
case '?':
default:
show_usage(NULL);
}
ac -= optind;
if (*(av+=optind)==NULL) {
show_usage(NULL);
}
if (!strncmp(*av, "add", strlen(*av))) {
add(ac,av);
} else if (!strncmp(*av, "delete", strlen(*av))) {
delete(ac,av);
} else if (!strncmp(*av, "flush", strlen(*av))) {
if (setsockopt(s,IPPROTO_IP,IP_FW_FLUSH,NULL,0)<0) {
fprintf(stderr,"%s: setsockopt failed.\n",progname);
exit(1);
}
printf("Flushed all rules.\n");
} else if (!strncmp(*av, "zero", strlen(*av))) {
if (setsockopt(s,IPPROTO_IP,IP_FW_ZERO,NULL,0)<0) {
fprintf(stderr,"%s: setsockopt failed.\n",progname);
exit(1);
}
printf("Accounting cleared.\n");
} else if (!strncmp(*av, "print", strlen(*av))) {
list(--ac,++av);
} else if (!strncmp(*av, "list", strlen(*av))) {
list(--ac,++av);
} else {
show_usage(NULL);
}
return 0;
}
int
main(ac, av)
int ac;
char **av;
{
#define MAX_ARGS 32
char buf[BUFSIZ];
char *args[MAX_ARGS];
char linename[10];
int i;
FILE *f;
s = socket( AF_INET, SOCK_RAW, IPPROTO_RAW );
if ( s < 0 ) {
fprintf(stderr,"%s: Can't open raw socket.\n"
"Must be root to use this programm. \n",progname);
exit(1);
}
setbuf(stdout,0);
strcpy(progname,*av);
if (av[1] && !access(av[1], R_OK)) {
lineno = 0;
f = fopen(av[1], "r");
while (fgets(buf, BUFSIZ, f)) {
if (buf[strlen(buf)-1]=='\n')
buf[strlen(buf)-1] = 0;
lineno++;
sprintf(linename, "Line %d", lineno);
args[0] = linename;
args[1] = buf;
while(*args[1] == ' ')
args[1]++;
i = 2;
while((args[i] = strchr(args[i-1],' '))) {
*(args[i]++) = 0;
while(*args[i] == ' ')
args[i]++;
i++;
}
if (*args[i-1] == 0)
i--;
args[i] = NULL;
ipfw_main(i, args);
}
fclose(f);
} else
ipfw_main(ac,av);
return 0;
}