NetBSD/usr.sbin/tcpdmatch/tcpdmatch.c

336 lines
9.3 KiB
C

/* $NetBSD: tcpdmatch.c,v 1.4 1998/03/05 18:23:31 christos Exp $ */
/*
* tcpdmatch - explain what tcpd would do in a specific case
*
* usage: tcpdmatch [-d] [-i inet_conf] daemon[@host] [user@]host
*
* -d: use the access control tables in the current directory.
*
* -i: location of inetd.conf file.
*
* All errors are reported to the standard error stream, including the errors
* that would normally be reported via the syslog daemon.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#) tcpdmatch.c 1.5 96/02/11 17:01:36";
#else
__RCSID("$NetBSD: tcpdmatch.c,v 1.4 1998/03/05 18:23:31 christos Exp $");
#endif
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <syslog.h>
#include <setjmp.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#ifndef INADDR_NONE
#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
#endif
#ifndef S_ISDIR
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif
/* Application-specific. */
#include "tcpd.h"
#include "inetcf.h"
#include "scaffold.h"
static void usage __P((char *));
static void expand __P((char *, char *, struct request_info *));
static void tcpdmatch __P((struct request_info *));
int main __P((int, char **));
/* The main program */
int main(argc, argv)
int argc;
char **argv;
{
struct hostent *hp;
char *myname = argv[0];
char *client;
char *server;
char *addr;
char *user;
char *daemon;
struct request_info request;
int ch;
char *inetcf = 0;
int count;
struct sockaddr_in server_sin;
struct sockaddr_in client_sin;
struct stat st;
/*
* Show what rule actually matched.
*/
hosts_access_verbose = 2;
/*
* Parse the JCL.
*/
while ((ch = getopt(argc, argv, "di:")) != -1) {
switch (ch) {
case 'd':
hosts_allow_table = "hosts.allow";
hosts_deny_table = "hosts.deny";
break;
case 'i':
inetcf = optarg;
break;
default:
usage(myname);
/* NOTREACHED */
}
}
if (argc != optind + 2)
usage(myname);
/*
* When confusion really strikes...
*/
if (check_path(REAL_DAEMON_DIR, &st) < 0) {
tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR);
} else if (!S_ISDIR(st.st_mode)) {
tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR);
}
/*
* Default is to specify a daemon process name. When daemon@host is
* specified, separate the two parts.
*/
if ((server = split_at(argv[optind], '@')) == 0)
server = unknown;
if (argv[optind][0] == '/') {
daemon = strrchr(argv[optind], '/') + 1;
tcpd_warn("%s: daemon name normalized to: %s", argv[optind], daemon);
} else {
daemon = argv[optind];
}
/*
* Default is to specify a client hostname or address. When user@host is
* specified, separate the two parts.
*/
if ((client = split_at(argv[optind + 1], '@')) != 0) {
user = argv[optind + 1];
} else {
client = argv[optind + 1];
user = unknown;
}
/*
* Analyze the inetd (or tlid) configuration file, so that we can warn
* the user about services that may not be wrapped, services that are not
* configured, or services that are wrapped in an incorrect manner. Allow
* for services that are not run from inetd, or that have tcpd access
* control built into them.
*/
inetcf = inet_cfg(inetcf);
inet_set("portmap", WR_NOT);
inet_set("rpcbind", WR_NOT);
switch (inet_get(daemon)) {
case WR_UNKNOWN:
tcpd_warn("%s: no such process name in %s", daemon, inetcf);
break;
case WR_NOT:
tcpd_warn("%s: service possibly not wrapped", daemon);
break;
}
/*
* Check accessibility of access control files.
*/
(void) check_path(hosts_allow_table, &st);
(void) check_path(hosts_deny_table, &st);
/*
* Fill in what we have figured out sofar. Use socket and DNS routines
* for address and name conversions. We attach stdout to the request so
* that banner messages will become visible.
*/
request_init(&request, RQ_DAEMON, daemon, RQ_USER, user, RQ_FILE, 1, 0);
sock_methods(&request);
/*
* If a server hostname is specified, insist that the name maps to at
* most one address. eval_hostname() warns the user about name server
* problems, while using the request.server structure as a cache for host
* address and name conversion results.
*/
if (NOT_INADDR(server) == 0 || HOSTNAME_KNOWN(server)) {
if ((hp = find_inet_addr(server)) == 0)
exit(1);
memset((char *) &server_sin, 0, sizeof(server_sin));
server_sin.sin_family = AF_INET;
request_set(&request, RQ_SERVER_SIN, &server_sin, 0);
for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
memcpy((char *) &server_sin.sin_addr, addr,
sizeof(server_sin.sin_addr));
/*
* Force evaluation of server host name and address. Host name
* conflicts will be reported while eval_hostname() does its job.
*/
request_set(&request, RQ_SERVER_NAME, "", RQ_SERVER_ADDR, "", 0);
if (STR_EQ(eval_hostname(request.server), unknown))
tcpd_warn("host address %s->name lookup failed",
eval_hostaddr(request.server));
}
if (count > 1) {
fprintf(stderr, "Error: %s has more than one address\n", server);
fprintf(stderr, "Please specify an address instead\n");
exit(1);
}
free((char *) hp);
} else {
request_set(&request, RQ_SERVER_NAME, server, 0);
}
/*
* If a client address is specified, we simulate the effect of client
* hostname lookup failure.
*/
if (dot_quad_addr(client) != INADDR_NONE) {
request_set(&request, RQ_CLIENT_ADDR, client, 0);
tcpdmatch(&request);
exit(0);
}
/*
* Perhaps they are testing special client hostname patterns that aren't
* really host names at all.
*/
if (NOT_INADDR(client) && HOSTNAME_KNOWN(client) == 0) {
request_set(&request, RQ_CLIENT_NAME, client, 0);
tcpdmatch(&request);
exit(0);
}
/*
* Otherwise, assume that a client hostname is specified, and insist that
* the address can be looked up. The reason for this requirement is that
* in real life the client address is available (at least with IP). Let
* eval_hostname() figure out if this host is properly registered, while
* using the request.client structure as a cache for host name and
* address conversion results.
*/
if ((hp = find_inet_addr(client)) == 0)
exit(1);
memset((char *) &client_sin, 0, sizeof(client_sin));
client_sin.sin_family = AF_INET;
request_set(&request, RQ_CLIENT_SIN, &client_sin, 0);
for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
memcpy((char *) &client_sin.sin_addr, addr,
sizeof(client_sin.sin_addr));
/*
* Force evaluation of client host name and address. Host name
* conflicts will be reported while eval_hostname() does its job.
*/
request_set(&request, RQ_CLIENT_NAME, "", RQ_CLIENT_ADDR, "", 0);
if (STR_EQ(eval_hostname(request.client), unknown))
tcpd_warn("host address %s->name lookup failed",
eval_hostaddr(request.client));
tcpdmatch(&request);
if (hp->h_addr_list[count + 1])
printf("\n");
}
free((char *) hp);
exit(0);
}
/* Explain how to use this program */
static void usage(myname)
char *myname;
{
fprintf(stderr, "usage: %s [-d] [-i inet_conf] daemon[@host] [user@]host\n",
myname);
fprintf(stderr, " -d: use allow/deny files in current directory\n");
fprintf(stderr, " -i: location of inetd.conf file\n");
exit(1);
}
/* Print interesting expansions */
static void expand(text, pattern, request)
char *text;
char *pattern;
struct request_info *request;
{
char buf[BUFSIZ];
if (STR_NE(percent_x(buf, sizeof(buf), pattern, request), unknown))
printf("%s %s\n", text, buf);
}
/* Try out a (server,client) pair */
static void tcpdmatch(request)
struct request_info *request;
{
int verdict;
/*
* Show what we really know. Suppress uninteresting noise.
*/
expand("client: hostname", "%n", request);
expand("client: address ", "%a", request);
expand("client: username", "%u", request);
expand("server: hostname", "%N", request);
expand("server: address ", "%A", request);
expand("server: process ", "%d", request);
/*
* Reset stuff that might be changed by options handlers. In dry-run
* mode, extension language routines that would not return should inform
* us of their plan, by clearing the dry_run flag. This is a bit clumsy
* but we must be able to verify hosts with more than one network
* address.
*/
rfc931_timeout = RFC931_TIMEOUT;
allow_severity = SEVERITY;
deny_severity = LOG_WARNING;
dry_run = 1;
/*
* When paranoid mode is enabled, access is rejected no matter what the
* access control rules say.
*/
#ifdef PARANOID
if (STR_EQ(eval_hostname(request->client), paranoid)) {
printf("access: denied (PARANOID mode)\n\n");
return;
}
#endif
/*
* Report the access control verdict.
*/
verdict = hosts_access(request);
printf("access: %s\n",
dry_run == 0 ? "delegated" :
verdict ? "granted" : "denied");
}