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/*
* (C)opyright 1995 by Darren Reed.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and due credit is given
* to the original author and the contributors.
*/
#include <stdio.h>
#include <ctype.h>
#include <assert.h>
#include <string.h>
#if !defined(__SVR4) && !defined(__svr4__)
#include <strings.h>
#else
#include <sys/byteorder.h>
#endif
#include <sys/types.h>
#include <sys/param.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip_var.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <netinet/tcp.h>
#include <netinet/ip_icmp.h>
#include <netinet/tcpip.h>
#include <net/if.h>
#include "ip_fil_compat.h"
#include <netdb.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include "ipf.h"
#include "ipt.h"
#ifndef lint
static char sccsid[] = "@(#)ipft_tx.c 1.7 6/5/96 (C) 1993 Darren Reed";
static char rcsid[] = "$Id: ipft_tx.c,v 1.5 1997/01/17 07:14:07 millert Exp $";
#endif
extern int opts;
extern u_long buildopts();
static char *tx_proto = "";
static int text_open(), text_close(), text_readip(), parseline();
static char tcp_flagset[] = "FSRPAU";
static u_char tcp_flags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH,
TH_ACK, TH_URG };
struct ipread iptext = { text_open, text_close, text_readip };
static FILE *tfp = NULL;
static int tfd = -1;
static u_long tx_hostnum();
static u_short tx_portnum();
/*
* returns an ip address as a long var as a result of either a DNS lookup or
* straight inet_addr() call
*/
u_long tx_hostnum(host, resolved)
char *host;
int *resolved;
{
struct hostent *hp;
struct netent *np;
*resolved = 0;
if (!strcasecmp("any",host))
return 0L;
if (isdigit(*host))
return inet_addr(host);
if (!(hp = gethostbyname(host))) {
if (!(np = getnetbyname(host))) {
*resolved = -1;
fprintf(stderr, "can't resolve hostname: %s\n", host);
return 0;
}
return np->n_net;
}
return *(u_long *)hp->h_addr;
}
/*
* find the port number given by the name, either from getservbyname() or
* straight atoi()
*/
u_short tx_portnum(name)
char *name;
{
struct servent *sp, *sp2;
u_short p1 = 0;
if (isdigit(*name))
return (u_short)atoi(name);
if (!tx_proto)
tx_proto = "tcp/udp";
if (strcasecmp(tx_proto, "tcp/udp")) {
sp = getservbyname(name, tx_proto);
if (sp)
return ntohs(sp->s_port);
(void) fprintf(stderr, "unknown service \"%s\".\n", name);
return 0;
}
sp = getservbyname(name, "tcp");
if (sp)
p1 = sp->s_port;
sp2 = getservbyname(name, "udp");
if (!sp || !sp2) {
(void) fprintf(stderr, "unknown tcp/udp service \"%s\".\n",
name);
return 0;
}
if (p1 != sp2->s_port) {
(void) fprintf(stderr, "%s %d/tcp is a different port to ",
name, p1);
(void) fprintf(stderr, "%s %d/udp\n", name, sp->s_port);
return 0;
}
return ntohs(p1);
}
char *tx_icmptypes[] = {
"echorep", (char *)NULL, (char *)NULL, "unreach", "squench",
"redir", (char *)NULL, (char *)NULL, "echo", (char *)NULL,
(char *)NULL, "timex", "paramprob", "timest", "timestrep",
"inforeq", "inforep", "maskreq", "maskrep", "END"
};
static int text_open(fname)
char *fname;
{
if (tfp && tfd != -1) {
rewind(tfp);
return tfd;
}
if (!strcmp(fname, "-")) {
tfd = 0;
tfp = stdin;
} else {
tfd = open(fname, O_RDONLY);
if (tfd != -1)
tfp = fdopen(tfd, "r");
}
return tfd;
}
static int text_close()
{
int cfd = tfd;
tfd = -1;
return close(cfd);
}
static int text_readip(buf, cnt, ifn, dir)
char *buf, **ifn;
int cnt, *dir;
{
register char *s;
struct ip *ip;
char line[513];
ip = (struct ip *)buf;
*ifn = NULL;
while (fgets(line, sizeof(line)-1, tfp)) {
if ((s = strchr(line, '\n')))
*s = '\0';
if ((s = strchr(line, '\r')))
*s = '\0';
if ((s = strchr(line, '#')))
*s = '\0';
if (!*line)
continue;
if (!(opts & OPT_BRIEF))
printf("input: %s\n", line);
*ifn = NULL;
*dir = 0;
if (!parseline(line, buf, ifn, dir))
#if 0
return sizeof(struct tcpiphdr);
#else
return sizeof(struct ip);
#endif
}
return -1;
}
static int parseline(line, ip, ifn, out)
char *line;
struct ip *ip;
char **ifn;
int *out;
{
tcphdr_t th, *tcp = &th;
struct icmp icmp, *ic = &icmp;
char *cps[20], **cpp, c, ipopts[68];
int i, r;
bzero((char *)ip, MAX(sizeof(*tcp), sizeof(*ic)) + sizeof(*ip));
bzero((char *)tcp, sizeof(*tcp));
bzero((char *)ic, sizeof(*ic));
bzero(ipopts, sizeof(ipopts));
ip->ip_hl = sizeof(*ip) >> 2;
ip->ip_v = IPVERSION;
for (i = 0, cps[0] = strtok(line, " \b\t\r\n"); cps[i] && i < 19; )
cps[++i] = strtok(NULL, " \b\t\r\n");
if (i < 2)
return 1;
cpp = cps;
c = **cpp;
if (!isalpha(c) || (tolower(c) != 'o' && tolower(c) != 'i')) {
fprintf(stderr, "bad direction \"%s\"\n", *cpp);
return 1;
}
*out = (tolower(c) == 'o') ? 1 : 0;
cpp++;
if (!strcasecmp(*cpp, "on")) {
cpp++;
if (!*cpp)
return 1;
*ifn = *cpp++;
}
c = **cpp;
ip->ip_len = sizeof(struct ip);
if (!strcasecmp(*cpp, "tcp") || !strcasecmp(*cpp, "udp") ||
!strcasecmp(*cpp, "icmp")) {
if (c == 't') {
ip->ip_p = IPPROTO_TCP;
ip->ip_len += sizeof(struct tcphdr);
tx_proto = "tcp";
} else if (c == 'u') {
ip->ip_p = IPPROTO_UDP;
ip->ip_len += sizeof(struct udphdr);
tx_proto = "udp";
} else {
ip->ip_p = IPPROTO_ICMP;
ip->ip_len += sizeof(struct icmp);
tx_proto = "icmp";
}
cpp++;
} else
ip->ip_p = IPPROTO_IP;
if (!*cpp)
return 1;
if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
char *last;
last = strchr(*cpp, ',');
if (!last) {
fprintf(stderr, "tcp/udp with no source port\n");
return 1;
}
*last++ = '\0';
tcp->th_sport = htons(tx_portnum(last));
}
ip->ip_src.s_addr = tx_hostnum(*cpp, &r);
cpp++;
if (!*cpp)
return 1;
if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
char *last;
last = strchr(*cpp, ',');
if (!last) {
fprintf(stderr, "tcp/udp with no destination port\n");
return 1;
}
*last++ = '\0';
tcp->th_dport = htons(tx_portnum(last));
}
ip->ip_dst.s_addr = tx_hostnum(*cpp, &r);
cpp++;
if (*cpp && ip->ip_p == IPPROTO_TCP) {
extern char tcp_flagset[];
extern u_char tcp_flags[];
char *s, *t;
for (s = *cpp; *s; s++)
if ((t = strchr(tcp_flagset, *s)))
tcp->th_flags |= tcp_flags[t - tcp_flagset];
if (tcp->th_flags)
cpp++;
assert(tcp->th_flags != 0);
} else if (*cpp && ip->ip_p == IPPROTO_ICMP) {
extern char *tx_icmptypes[];
char **s, *t;
int i;
for (s = tx_icmptypes, i = 0; !*s || strcmp(*s, "END");
s++, i++)
if (*s && !strncasecmp(*cpp, *s, strlen(*s))) {
ic->icmp_type = i;
if ((t = strchr(*cpp, ',')))
ic->icmp_code = atoi(t+1);
cpp++;
break;
}
}
if (*cpp && !strcasecmp(*cpp, "opt")) {
u_long olen;
cpp++;
olen = buildopts(*cpp, ipopts);
if (olen) {
bcopy(ipopts, (char *)(ip + 1), olen);
ip->ip_hl += olen >> 2;
}
}
if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
bcopy((char *)tcp, ((char *)ip) + (ip->ip_hl << 2),
sizeof(*tcp));
else if (ip->ip_p == IPPROTO_ICMP)
bcopy((char *)ic, ((char *)ip) + (ip->ip_hl << 2),
sizeof(*ic));
return 0;
}
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