-# $OpenBSD: Makefile,v 1.17 1997/01/20 07:46:47 graichen Exp $
+# $OpenBSD: Makefile,v 1.18 1997/02/26 03:06:48 downsj Exp $
# $NetBSD: Makefile,v 1.20.4.1 1996/06/14 17:22:38 cgd Exp $
SUBDIR= csu libarch libc libcom_err libcompat libcurses libedit \
libform libl libm libmenu libocurses libpanel libpcap libresolv \
- librpcsvc libskey libss libtelnet libterm libtermlib libutil liby \
- libz
+ librpcsvc libskey libss libtelnet libterm libtermlib libutil libwrap \
+ liby libz
# XXX Temporarely until all ports are able to use libkvm (leo)
.if (${MACHINE} == "amiga") || \
--- /dev/null
+# $OpenBSD: Makefile,v 1.1 1997/02/26 03:06:49 downsj Exp $
+
+LIB= wrap
+SRCS= hosts_access.c options.c shell_cmd.c rfc931.c eval.c \
+ hosts_ctl.c refuse.c percent_x.c clean_exit.c \
+ fix_options.c socket.c update.c misc.c \
+ diag.c percent_m.c
+HDRS= tcpd.h
+
+# Configuration options for libwrap.
+CFLAGS+=-DPROCESS_OPTIONS -DFACILITY=LOG_AUTH -DSEVERITY=LOG_INFO \
+ -DRFC931_TIMEOUT=10 -DHOSTS_ACCESS -DALWAYS_HOSTNAME \
+ -DHOSTS_DENY=\"/etc/hosts.deny\" -DHOSTS_ALLOW=\"/etc/hosts.allow\" \
+ -DNETGROUP -DSYS_ERRLIST_DEFINED
+
+MAN= hosts_access.3 hosts_access.5 hosts_options.5
+MLINKS+=hosts_access.5 hosts.allow.5
+MLINKS+=hosts_access.5 hosts.deny.5
+MLINKS+=hosts_access.3 hosts_ctl.3
+MLINKS+=hosts_access.3 request_init.3
+MLINKS+=hosts_access.3 request_set.3
+
+includes:
+ @cd ${.CURDIR}; for i in $(HDRS); do \
+ j="cmp -s $$i ${DESTDIR}/usr/include/$$i || \
+ ${INSTALL} ${COPY} -o ${BINOWN} -g ${BINGRP} -m 444 $$i \
+ ${DESTDIR}/usr/include"; \
+ echo $$j; \
+ eval "$$j"; \
+ done
+
+.include <bsd.lib.mk>
--- /dev/null
+/* $OpenBSD: clean_exit.c,v 1.1 1997/02/26 03:06:50 downsj Exp $ */
+
+/*
+ * clean_exit() cleans up and terminates the program. It should be called
+ * instead of exit() when for some reason the real network daemon will not or
+ * cannot be run. Reason: in the case of a datagram-oriented service we must
+ * discard the not-yet received data from the client. Otherwise, inetd will
+ * see the same datagram again and again, and go into a loop.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) clean_exit.c 1.4 94/12/28 17:42:19";
+#else
+static char rcsid[] = "$OpenBSD: clean_exit.c,v 1.1 1997/02/26 03:06:50 downsj Exp $";
+#endif
+#endif
+
+#include <stdio.h>
+#include <unistd.h>
+
+#include "tcpd.h"
+
+/* clean_exit - clean up and exit */
+
+void clean_exit(request)
+struct request_info *request;
+{
+
+ /*
+ * In case of unconnected protocols we must eat up the not-yet received
+ * data or inetd will loop.
+ */
+
+ if (request->sink)
+ request->sink(request->fd);
+
+ /*
+ * Be kind to the inetd. We already reported the problem via the syslogd,
+ * and there is no need for additional garbage in the logfile.
+ */
+
+ sleep(5);
+ exit(0);
+}
--- /dev/null
+/* $OpenBSD: diag.c,v 1.1 1997/02/26 03:06:50 downsj Exp $ */
+
+ /*
+ * Routines to report various classes of problems. Each report is decorated
+ * with the current context (file name and line number), if available.
+ *
+ * tcpd_warn() reports a problem and proceeds.
+ *
+ * tcpd_jump() reports a problem and jumps.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) diag.c 1.1 94/12/28 17:42:20";
+#else
+static char rcsid[] = "$OpenBSD: diag.c,v 1.1 1997/02/26 03:06:50 downsj Exp $";
+#endif
+#endif
+
+/* System libraries */
+
+#include <syslog.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <setjmp.h>
+
+/* Local stuff */
+
+#include "tcpd.h"
+
+struct tcpd_context tcpd_context;
+jmp_buf tcpd_buf;
+
+/* tcpd_diag - centralize error reporter */
+
+static void tcpd_diag(severity, tag, format, ap)
+int severity;
+char *tag;
+char *format;
+va_list ap;
+{
+ char fmt[BUFSIZ];
+
+ if (tcpd_context.file)
+ sprintf(fmt, "%s: %s, line %d: %s",
+ tag, tcpd_context.file, tcpd_context.line, format);
+ else
+ sprintf(fmt, "%s: %s", tag, format);
+ vsyslog(severity, fmt, ap);
+}
+
+/* tcpd_warn - report problem of some sort and proceed */
+
+void VARARGS(tcpd_warn, char *, format)
+{
+ va_list ap;
+
+ VASTART(ap, char *, format);
+ tcpd_diag(LOG_ERR, "warning", format, ap);
+ VAEND(ap);
+}
+
+/* tcpd_jump - report serious problem and jump */
+
+void VARARGS(tcpd_jump, char *, format)
+{
+ va_list ap;
+
+ VASTART(ap, char *, format);
+ tcpd_diag(LOG_ERR, "error", format, ap);
+ VAEND(ap);
+ longjmp(tcpd_buf, AC_ERROR);
+}
--- /dev/null
+/* $OpenBSD: eval.c,v 1.1 1997/02/26 03:06:50 downsj Exp $ */
+
+ /*
+ * Routines for controlled evaluation of host names, user names, and so on.
+ * They are, in fact, wrappers around the functions that are specific for
+ * the sockets or TLI programming interfaces. The request_info and host_info
+ * structures are used for result cacheing.
+ *
+ * These routines allows us to postpone expensive operations until their
+ * results are really needed. Examples are hostname lookups and double
+ * checks, or username lookups. Information that cannot be retrieved is
+ * given the value "unknown" ("paranoid" in case of hostname problems).
+ *
+ * When ALWAYS_HOSTNAME is off, hostname lookup is done only when required by
+ * tcpd paranoid mode, by access control patterns, or by %letter expansions.
+ *
+ * When ALWAYS_RFC931 mode is off, user lookup is done only when required by
+ * access control patterns or %letter expansions.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) eval.c 1.3 95/01/30 19:51:45";
+#else
+static char rcsid[] = "$OpenBSD: eval.c,v 1.1 1997/02/26 03:06:50 downsj Exp $";
+#endif
+#endif
+
+/* System libraries. */
+
+#include <stdio.h>
+#include <string.h>
+
+/* Local stuff. */
+
+#include "tcpd.h"
+
+ /*
+ * When a string has the value STRING_UNKNOWN, it means: don't bother, I
+ * tried to look up the data but it was unavailable for some reason. When a
+ * host name has the value STRING_PARANOID it means there was a name/address
+ * conflict.
+ */
+char unknown[] = STRING_UNKNOWN;
+char paranoid[] = STRING_PARANOID;
+
+/* eval_user - look up user name */
+
+char *eval_user(request)
+struct request_info *request;
+{
+ if (request->user[0] == 0) {
+ strcpy(request->user, unknown);
+ if (request->sink == 0 && request->client->sin && request->server->sin)
+ rfc931(request->client->sin, request->server->sin, request->user);
+ }
+ return (request->user);
+}
+
+/* eval_hostaddr - look up printable address */
+
+char *eval_hostaddr(host)
+struct host_info *host;
+{
+ if (host->addr[0] == 0) {
+ strcpy(host->addr, unknown);
+ if (host->request->hostaddr != 0)
+ host->request->hostaddr(host);
+ }
+ return (host->addr);
+}
+
+/* eval_hostname - look up host name */
+
+char *eval_hostname(host)
+struct host_info *host;
+{
+ if (host->name[0] == 0) {
+ strcpy(host->name, unknown);
+ if (host->request->hostname != 0)
+ host->request->hostname(host);
+ }
+ return (host->name);
+}
+
+/* eval_hostinfo - return string with host name (preferred) or address */
+
+char *eval_hostinfo(host)
+struct host_info *host;
+{
+ char *hostname;
+
+#ifndef ALWAYS_HOSTNAME /* no implicit host lookups */
+ if (host->name[0] == 0)
+ return (eval_hostaddr(host));
+#endif
+ hostname = eval_hostname(host);
+ if (HOSTNAME_KNOWN(hostname)) {
+ return (host->name);
+ } else {
+ return (eval_hostaddr(host));
+ }
+}
+
+/* eval_client - return string with as much about the client as we know */
+
+char *eval_client(request)
+struct request_info *request;
+{
+ static char both[2 * STRING_LENGTH];
+ char *hostinfo = eval_hostinfo(request->client);
+
+#ifndef ALWAYS_RFC931 /* no implicit user lookups */
+ if (request->user[0] == 0)
+ return (hostinfo);
+#endif
+ if (STR_NE(eval_user(request), unknown)) {
+ sprintf(both, "%s@%s", request->user, hostinfo);
+ return (both);
+ } else {
+ return (hostinfo);
+ }
+}
+
+/* eval_server - return string with as much about the server as we know */
+
+char *eval_server(request)
+struct request_info *request;
+{
+ static char both[2 * STRING_LENGTH];
+ char *host = eval_hostinfo(request->server);
+ char *daemon = eval_daemon(request);
+
+ if (STR_NE(host, unknown)) {
+ sprintf(both, "%s@%s", daemon, host);
+ return (both);
+ } else {
+ return (daemon);
+ }
+}
--- /dev/null
+/* $OpenBSD: fix_options.c,v 1.1 1997/02/26 03:06:51 downsj Exp $ */
+
+ /*
+ * Routine to disable IP-level socket options. This code was taken from 4.4BSD
+ * rlogind and kernel source, but all mistakes in it are my fault.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) fix_options.c 1.4 97/02/12 02:13:22";
+#else
+static char rcsid[] = "$OpenBSD: fix_options.c,v 1.1 1997/02/26 03:06:51 downsj Exp $";
+#endif
+#endif
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <syslog.h>
+
+#ifndef IPOPT_OPTVAL
+#define IPOPT_OPTVAL 0
+#define IPOPT_OLEN 1
+#endif
+
+#include "tcpd.h"
+
+#define BUFFER_SIZE 512 /* Was: BUFSIZ */
+
+/* fix_options - get rid of IP-level socket options */
+
+void
+fix_options(request)
+struct request_info *request;
+{
+#ifdef IP_OPTIONS
+ unsigned char optbuf[BUFFER_SIZE / 3], *cp;
+ char lbuf[BUFFER_SIZE], *lp;
+ int optsize = sizeof(optbuf), ipproto;
+ struct protoent *ip;
+ int fd = request->fd;
+ unsigned int opt;
+ int optlen;
+ unsigned char *first_option = optbuf;
+
+ if ((ip = getprotobyname("ip")) != 0)
+ ipproto = ip->p_proto;
+ else
+ ipproto = IPPROTO_IP;
+
+ if (getsockopt(fd, ipproto, IP_OPTIONS, (char *) optbuf, &optsize) == 0
+ && optsize != 0) {
+
+ /*
+ * Horror! 4.[34] BSD getsockopt() prepends the first-hop destination
+ * address to the result IP options list when source routing options
+ * are present (see <netinet/ip_var.h>), but produces no output for
+ * other IP options. Solaris 2.x getsockopt() does produce output for
+ * non-routing IP options, and uses the same format as BSD even when
+ * the space for the destination address is unused. However, we must
+ * be prepared to deal with systems that return the options only. The
+ * code below does the right thing with 4.[34]BSD derivatives and
+ * Solaris 2, but may occasionally miss source routing options on
+ * incompatible systems such as Linux. Their choice.
+ */
+#define ADDR_LEN sizeof(struct in_addr)
+
+ for (cp = optbuf + ADDR_LEN; cp < optbuf + optsize; cp++) {
+ opt = cp[IPOPT_OPTVAL];
+ if (opt != IPOPT_NOP) {
+ if (opt == IPOPT_RR
+ || opt == IPOPT_TS
+ || opt == IPOPT_SECURITY
+ || opt == IPOPT_LSRR
+ || opt == IPOPT_SATID
+ || opt == IPOPT_SSRR)
+ first_option = cp;
+ break;
+ }
+ }
+
+ /*
+ * Look for source routing options. Drop the connection when one is
+ * found. Just wiping the IP options is insufficient: we would still
+ * help the attacker by providing a real TCP sequence number, and the
+ * attacker would still be able to send packets (blind spoofing). I
+ * discussed this attack with Niels Provos, half a year before the
+ * attack was described in open mailing lists.
+ *
+ * It would be cleaner to just return a yes/no reply and let the caller
+ * decide how to deal with it. Resident servers should not terminate.
+ * However I am not prepared to make changes to internal interfaces
+ * on short notice.
+ */
+ for (cp = first_option; cp < optbuf + optsize; cp += optlen) {
+ opt = cp[IPOPT_OPTVAL];
+ if (opt == IPOPT_LSRR || opt == IPOPT_SSRR) {
+ syslog(LOG_WARNING,
+ "refused connect from %s with IP source routing options",
+ eval_client(request));
+ clean_exit(request);
+ }
+ if (opt == IPOPT_EOL)
+ break;
+ if (opt == IPOPT_NOP) {
+ optlen = 1;
+ } else {
+ optlen = cp[IPOPT_OLEN];
+ if (optlen <= 0) /* Do not loop! */
+ break;
+ }
+ }
+ lp = lbuf;
+ for (cp = optbuf; optsize > 0; cp++, optsize--, lp += 3)
+ sprintf(lp, " %2.2x", *cp);
+ syslog(LOG_NOTICE,
+ "connect from %s with IP options (ignored):%s",
+ eval_client(request), lbuf);
+ if (setsockopt(fd, ipproto, IP_OPTIONS, (char *) 0, optsize) != 0) {
+ syslog(LOG_ERR, "setsockopt IP_OPTIONS NULL: %m");
+ clean_exit(request);
+ }
+ }
+#endif
+}
--- /dev/null
+.\" $OpenBSD: hosts_access.3,v 1.1 1997/02/26 03:06:51 downsj Exp $
+.TH HOSTS_ACCESS 3
+.SH NAME
+hosts_access, hosts_ctl, request_init, request_set \- access control library
+.SH SYNOPSIS
+.nf
+#include "tcpd.h"
+
+extern int allow_severity;
+extern int deny_severity;
+
+struct request_info *request_init(request, key, value, ..., 0)
+struct request_info *request;
+
+struct request_info *request_set(request, key, value, ..., 0)
+struct request_info *request;
+
+int hosts_access(request)
+struct request_info *request;
+
+int hosts_ctl(daemon, client_name, client_addr, client_user)
+char *daemon;
+char *client_name;
+char *client_addr;
+char *client_user;
+.fi
+.SH DESCRIPTION
+The routines described in this document are part of the \fIlibwrap.a\fR
+library. They implement a rule-based access control language with
+optional shell commands that are executed when a rule fires.
+.PP
+request_init() initializes a structure with information about a client
+request. request_set() updates an already initialized request
+structure. Both functions take a variable-length list of key-value
+pairs and return their first argument. The argument lists are
+terminated with a zero key value. All string-valued arguments are
+copied. The expected keys (and corresponding value types) are:
+.IP "RQ_FILE (int)"
+The file descriptor associated with the request.
+.IP "RQ_CLIENT_NAME (char *)"
+The client host name.
+.IP "RQ_CLIENT_ADDR (char *)"
+A printable representation of the client network address.
+.IP "RQ_CLIENT_SIN (struct sockaddr_in *)"
+An internal representation of the client network address and port. The
+contents of the structure are not copied.
+.IP "RQ_SERVER_NAME (char *)"
+The hostname associated with the server endpoint address.
+.IP "RQ_SERVER_ADDR (char *)"
+A printable representation of the server endpoint address.
+.IP "RQ_SERVER_SIN (struct sockaddr_in *)"
+An internal representation of the server endpoint address and port.
+The contents of the structure are not copied.
+.IP "RQ_DAEMON (char *)"
+The name of the daemon process running on the server host.
+.IP "RQ_USER (char *)"
+The name of the user on whose behalf the client host makes the request.
+.PP
+hosts_access() consults the access control tables described in the
+\fIhosts_access(5)\fR manual page. When internal endpoint information
+is available, host names and client user names are looked up on demand,
+using the request structure as a cache. hosts_access() returns zero if
+access should be denied.
+.PP
+hosts_ctl() is a wrapper around the request_init() and hosts_access()
+routines with a perhaps more convenient interface (though it does not
+pass on enough information to support automated client username
+lookups). The client host address, client host name and username
+arguments should contain valid data or STRING_UNKNOWN. hosts_ctl()
+returns zero if access should be denied.
+.PP
+The \fIallow_severity\fR and \fIdeny_severity\fR variables determine
+how accepted and rejected requests may be logged. They must be provided
+by the caller and may be modified by rules in the access control
+tables.
+.SH DIAGNOSTICS
+Problems are reported via the syslog daemon.
+.SH SEE ALSO
+hosts_access(5), format of the access control tables.
+hosts_options(5), optional extensions to the base language.
+.SH FILES
+/etc/hosts.allow, /etc/hosts.deny, access control tables.
+.SH BUGS
+hosts_access() uses the strtok() library function. This may interfere
+with other code that relies on strtok().
+.SH AUTHOR
+.na
+.nf
+Wietse Venema (wietse@wzv.win.tue.nl)
+Department of Mathematics and Computing Science
+Eindhoven University of Technology
+Den Dolech 2, P.O. Box 513,
+5600 MB Eindhoven, The Netherlands
+\" @(#) hosts_access.3 1.8 96/02/11 17:01:26
--- /dev/null
+.\" $OpenBSD: hosts_access.5,v 1.1 1997/02/26 03:06:52 downsj Exp $
+.TH HOSTS_ACCESS 5
+.SH NAME
+hosts_access \- format of host access control files
+.SH DESCRIPTION
+This manual page describes a simple access control language that is
+based on client (host name/address, user name), and server (process
+name, host name/address) patterns. Examples are given at the end. The
+impatient reader is encouraged to skip to the EXAMPLES section for a
+quick introduction.
+.PP
+An extended version of the access control language is described in the
+\fIhosts_options\fR(5) document. The extensions are turned on at
+program build time by building with -DPROCESS_OPTIONS.
+.PP
+In the following text, \fIdaemon\fR is the the process name of a
+network daemon process, and \fIclient\fR is the name and/or address of
+a host requesting service. Network daemon process names are specified
+in the inetd configuration file.
+.SH ACCESS CONTROL FILES
+The access control software consults two files. The search stops
+at the first match:
+.IP \(bu
+Access will be granted when a (daemon,client) pair matches an entry in
+the \fI/etc/hosts.allow\fR file.
+.IP \(bu
+Otherwise, access will be denied when a (daemon,client) pair matches an
+entry in the \fI/etc/hosts.deny\fR file.
+.IP \(bu
+Otherwise, access will be granted.
+.PP
+A non-existing access control file is treated as if it were an empty
+file. Thus, access control can be turned off by providing no access
+control files.
+.SH ACCESS CONTROL RULES
+Each access control file consists of zero or more lines of text. These
+lines are processed in order of appearance. The search terminates when a
+match is found.
+.IP \(bu
+A newline character is ignored when it is preceded by a backslash
+character. This permits you to break up long lines so that they are
+easier to edit.
+.IP \(bu
+Blank lines or lines that begin with a `#\' character are ignored.
+This permits you to insert comments and whitespace so that the tables
+are easier to read.
+.IP \(bu
+All other lines should satisfy the following format, things between []
+being optional:
+.sp
+.ti +3
+daemon_list : client_list [ : shell_command ]
+.PP
+\fIdaemon_list\fR is a list of one or more daemon process names
+(argv[0] values) or wildcards (see below).
+.PP
+\fIclient_list\fR is a list
+of one or more host names, host addresses, patterns or wildcards (see
+below) that will be matched against the client host name or address.
+.PP
+The more complex forms \fIdaemon@host\fR and \fIuser@host\fR are
+explained in the sections on server endpoint patterns and on client
+username lookups, respectively.
+.PP
+List elements should be separated by blanks and/or commas.
+.PP
+With the exception of NIS (YP) netgroup lookups, all access control
+checks are case insensitive.
+.ne 4
+.SH PATTERNS
+The access control language implements the following patterns:
+.IP \(bu
+A string that begins with a `.\' character. A host name is matched if
+the last components of its name match the specified pattern. For
+example, the pattern `.tue.nl\' matches the host name
+`wzv.win.tue.nl\'.
+.IP \(bu
+A string that ends with a `.\' character. A host address is matched if
+its first numeric fields match the given string. For example, the
+pattern `131.155.\' matches the address of (almost) every host on the
+Eind\%hoven University network (131.155.x.x).
+.IP \(bu
+A string that begins with an `@\' character is treated as an NIS
+(formerly YP) netgroup name. A host name is matched if it is a host
+member of the specified netgroup. Netgroup matches are not supported
+for daemon process names or for client user names.
+.IP \(bu
+An expression of the form `n.n.n.n/m.m.m.m\' is interpreted as a
+`net/mask\' pair. A host address is matched if `net\' is equal to the
+bitwise AND of the address and the `mask\'. For example, the net/mask
+pattern `131.155.72.0/255.255.254.0\' matches every address in the
+range `131.155.72.0\' through `131.155.73.255\'.
+.SH WILDCARDS
+The access control language supports explicit wildcards:
+.IP ALL
+The universal wildcard, always matches.
+.IP LOCAL
+Matches any host whose name does not contain a dot character.
+.IP UNKNOWN
+Matches any user whose name is unknown, and matches any host whose name
+\fIor\fR address are unknown. This pattern should be used with care:
+host names may be unavailable due to temporary name server problems. A
+network address will be unavailable when the software cannot figure out
+what type of network it is talking to.
+.IP KNOWN
+Matches any user whose name is known, and matches any host whose name
+\fIand\fR address are known. This pattern should be used with care:
+host names may be unavailable due to temporary name server problems. A
+network address will be unavailable when the software cannot figure out
+what type of network it is talking to.
+.IP PARANOID
+Matches any host whose name does not match its address. When tcpd is
+built with -DPARANOID (default mode), it drops requests from such
+clients even before looking at the access control tables. Build
+without -DPARANOID when you want more control over such requests.
+.ne 6
+.SH OPERATORS
+.IP EXCEPT
+Intended use is of the form: `list_1 EXCEPT list_2\'; this construct
+matches anything that matches \fIlist_1\fR unless it matches
+\fIlist_2\fR. The EXCEPT operator can be used in daemon_lists and in
+client_lists. The EXCEPT operator can be nested: if the control
+language would permit the use of parentheses, `a EXCEPT b EXCEPT c\'
+would parse as `(a EXCEPT (b EXCEPT c))\'.
+.br
+.ne 6
+.SH SHELL COMMANDS
+If the first-matched access control rule contains a shell command, that
+command is subjected to %<letter> substitutions (see next section).
+The result is executed by a \fI/bin/sh\fR child process with standard
+input, output and error connected to \fI/dev/null\fR. Specify an `&\'
+at the end of the command if you do not want to wait until it has
+completed.
+.PP
+Shell commands should not rely on the PATH setting of the inetd.
+Instead, they should use absolute path names, or they should begin with
+an explicit PATH=whatever statement.
+.PP
+The \fIhosts_options\fR(5) document describes an alternative language
+that uses the shell command field in a different and incompatible way.
+.SH % EXPANSIONS
+The following expansions are available within shell commands:
+.IP "%a (%A)"
+The client (server) host address.
+.IP %c
+Client information: user@host, user@address, a host name, or just an
+address, depending on how much information is available.
+.IP %d
+The daemon process name (argv[0] value).
+.IP "%h (%H)"
+The client (server) host name or address, if the host name is
+unavailable.
+.IP "%n (%N)"
+The client (server) host name (or "unknown" or "paranoid").
+.IP %p
+The daemon process id.
+.IP %s
+Server information: daemon@host, daemon@address, or just a daemon name,
+depending on how much information is available.
+.IP %u
+The client user name (or "unknown").
+.IP %%
+Expands to a single `%\' character.
+.PP
+Characters in % expansions that may confuse the shell are replaced by
+underscores.
+.SH SERVER ENDPOINT PATTERNS
+In order to distinguish clients by the network address that they
+connect to, use patterns of the form:
+.sp
+.ti +3
+process_name@host_pattern : client_list ...
+.sp
+Patterns like these can be used when the machine has different internet
+addresses with different internet hostnames. Service providers can use
+this facility to offer FTP, GOPHER or WWW archives with internet names
+that may even belong to different organizations. See also the `twist'
+option in the hosts_options(5) document. Some systems (Solaris,
+FreeBSD) can have more than one internet address on one physical
+interface; with other systems you may have to resort to SLIP or PPP
+pseudo interfaces that live in a dedicated network address space.
+.sp
+The host_pattern obeys the same syntax rules as host names and
+addresses in client_list context. Usually, server endpoint information
+is available only with connection-oriented services.
+.SH CLIENT USERNAME LOOKUP
+When the client host supports the RFC 931 protocol or one of its
+descendants (TAP, IDENT, RFC 1413) the wrapper programs can retrieve
+additional information about the owner of a connection. Client username
+information, when available, is logged together with the client host
+name, and can be used to match patterns like:
+.PP
+.ti +3
+daemon_list : ... user_pattern@host_pattern ...
+.PP
+The daemon wrappers can be configured at compile time to perform
+rule-driven username lookups (default) or to always interrogate the
+client host. In the case of rule-driven username lookups, the above
+rule would cause username lookup only when both the \fIdaemon_list\fR
+and the \fIhost_pattern\fR match.
+.PP
+A user pattern has the same syntax as a daemon process pattern, so the
+same wildcards apply (netgroup membership is not supported). One
+should not get carried away with username lookups, though.
+.IP \(bu
+The client username information cannot be trusted when it is needed
+most, i.e. when the client system has been compromised. In general,
+ALL and (UN)KNOWN are the only user name patterns that make sense.
+.IP \(bu
+Username lookups are possible only with TCP-based services, and only
+when the client host runs a suitable daemon; in all other cases the
+result is "unknown".
+.IP \(bu
+A well-known UNIX kernel bug may cause loss of service when username
+lookups are blocked by a firewall. The wrapper README document
+describes a procedure to find out if your kernel has this bug.
+.IP \(bu
+Username lookups may cause noticeable delays for non-UNIX users. The
+default timeout for username lookups is 10 seconds: too short to cope
+with slow networks, but long enough to irritate PC users.
+.PP
+Selective username lookups can alleviate the last problem. For example,
+a rule like:
+.PP
+.ti +3
+daemon_list : @pcnetgroup ALL@ALL
+.PP
+would match members of the pc netgroup without doing username lookups,
+but would perform username lookups with all other systems.
+.SH DETECTING ADDRESS SPOOFING ATTACKS
+A flaw in the sequence number generator of many TCP/IP implementations
+allows intruders to easily impersonate trusted hosts and to break in
+via, for example, the remote shell service. The IDENT (RFC931 etc.)
+service can be used to detect such and other host address spoofing
+attacks.
+.PP
+Before accepting a client request, the wrappers can use the IDENT
+service to find out that the client did not send the request at all.
+When the client host provides IDENT service, a negative IDENT lookup
+result (the client matches `UNKNOWN@host') is strong evidence of a host
+spoofing attack.
+.PP
+A positive IDENT lookup result (the client matches `KNOWN@host') is
+less trustworthy. It is possible for an intruder to spoof both the
+client connection and the IDENT lookup, although doing so is much
+harder than spoofing just a client connection. It may also be that
+the client\'s IDENT server is lying.
+.PP
+Note: IDENT lookups don\'t work with UDP services.
+.SH EXAMPLES
+The language is flexible enough that different types of access control
+policy can be expressed with a minimum of fuss. Although the language
+uses two access control tables, the most common policies can be
+implemented with one of the tables being trivial or even empty.
+.PP
+When reading the examples below it is important to realize that the
+allow table is scanned before the deny table, that the search
+terminates when a match is found, and that access is granted when no
+match is found at all.
+.PP
+The examples use host and domain names. They can be improved by
+including address and/or network/netmask information, to reduce the
+impact of temporary name server lookup failures.
+.SH MOSTLY CLOSED
+In this case, access is denied by default. Only explicitly authorized
+hosts are permitted access.
+.PP
+The default policy (no access) is implemented with a trivial deny
+file:
+.PP
+.ne 2
+/etc/hosts.deny:
+.in +3
+ALL: ALL
+.PP
+This denies all service to all hosts, unless they are permitted access
+by entries in the allow file.
+.PP
+The explicitly authorized hosts are listed in the allow file.
+For example:
+.PP
+.ne 2
+/etc/hosts.allow:
+.in +3
+ALL: LOCAL @some_netgroup
+.br
+ALL: .foobar.edu EXCEPT terminalserver.foobar.edu
+.PP
+The first rule permits access from hosts in the local domain (no `.\'
+in the host name) and from members of the \fIsome_netgroup\fP
+netgroup. The second rule permits access from all hosts in the
+\fIfoobar.edu\fP domain (notice the leading dot), with the exception of
+\fIterminalserver.foobar.edu\fP.
+.SH MOSTLY OPEN
+Here, access is granted by default; only explicitly specified hosts are
+refused service.
+.PP
+The default policy (access granted) makes the allow file redundant so
+that it can be omitted. The explicitly non-authorized hosts are listed
+in the deny file. For example:
+.PP
+/etc/hosts.deny:
+.in +3
+ALL: some.host.name, .some.domain
+.br
+ALL EXCEPT in.fingerd: other.host.name, .other.domain
+.PP
+The first rule denies some hosts and domains all services; the second
+rule still permits finger requests from other hosts and domains.
+.SH BOOBY TRAPS
+The next example permits tftp requests from hosts in the local domain
+(notice the leading dot). Requests from any other hosts are denied.
+Instead of the requested file, a finger probe is sent to the offending
+host. The result is mailed to the superuser.
+.PP
+.ne 2
+/etc/hosts.allow:
+.in +3
+.nf
+in.tftpd: LOCAL, .my.domain
+.PP
+.ne 2
+/etc/hosts.deny:
+.in +3
+.nf
+in.tftpd: ALL: (/some/where/safe_finger -l @%h | \\
+ /usr/ucb/mail -s %d-%h root) &
+.fi
+.PP
+The safe_finger command comes with the tcpd wrapper and should be
+installed in a suitable place. It limits possible damage from data sent
+by the remote finger server. It gives better protection than the
+standard finger command.
+.PP
+The expansion of the %h (client host) and %d (service name) sequences
+is described in the section on shell commands.
+.PP
+Warning: do not booby-trap your finger daemon, unless you are prepared
+for infinite finger loops.
+.PP
+On network firewall systems this trick can be carried even further.
+The typical network firewall only provides a limited set of services to
+the outer world. All other services can be "bugged" just like the above
+tftp example. The result is an excellent early-warning system.
+.br
+.ne 4
+.SH DIAGNOSTICS
+An error is reported when a syntax error is found in a host access
+control rule; when the length of an access control rule exceeds the
+capacity of an internal buffer; when an access control rule is not
+terminated by a newline character; when the result of %<letter>
+expansion would overflow an internal buffer; when a system call fails
+that shouldn\'t. All problems are reported via the syslog daemon.
+.SH FILES
+.na
+.nf
+/etc/hosts.allow, (daemon,client) pairs that are granted access.
+/etc/hosts.deny, (daemon,client) pairs that are denied access.
+.ad
+.fi
+.SH SEE ALSO
+.nf
+tcpd(8) tcp/ip daemon wrapper program.
+tcpdchk(8), tcpdmatch(8), test programs.
+.SH BUGS
+If a name server lookup times out, the host name will not be available
+to the access control software, even though the host is registered.
+.PP
+Domain name server lookups are case insensitive; NIS (formerly YP)
+netgroup lookups are case sensitive.
+.SH AUTHOR
+.na
+.nf
+Wietse Venema (wietse@wzv.win.tue.nl)
+Department of Mathematics and Computing Science
+Eindhoven University of Technology
+Den Dolech 2, P.O. Box 513,
+5600 MB Eindhoven, The Netherlands
+\" @(#) hosts_access.5 1.20 95/01/30 19:51:46
--- /dev/null
+/* $OpenBSD: hosts_access.c,v 1.1 1997/02/26 03:06:52 downsj Exp $ */
+
+ /*
+ * This module implements a simple access control language that is based on
+ * host (or domain) names, NIS (host) netgroup names, IP addresses (or
+ * network numbers) and daemon process names. When a match is found the
+ * search is terminated, and depending on whether PROCESS_OPTIONS is defined,
+ * a list of options is executed or an optional shell command is executed.
+ *
+ * Host and user names are looked up on demand, provided that suitable endpoint
+ * information is available as sockaddr_in structures or TLI netbufs. As a
+ * side effect, the pattern matching process may change the contents of
+ * request structure fields.
+ *
+ * Diagnostics are reported through syslog(3).
+ *
+ * Compile with -DNETGROUP if your library provides support for netgroups.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) hosts_access.c 1.21 97/02/12 02:13:22";
+#else
+static char rcsid[] = "$OpenBSD: hosts_access.c,v 1.1 1997/02/26 03:06:52 downsj Exp $";
+#endif
+#endif
+
+/* System libraries. */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <syslog.h>
+#include <ctype.h>
+#include <errno.h>
+#include <setjmp.h>
+#include <string.h>
+#ifdef NETGROUP
+#include <netgroup.h>
+#endif
+
+extern int errno;
+
+#ifndef INADDR_NONE
+#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
+#endif
+
+/* Local stuff. */
+
+#include "tcpd.h"
+
+/* Error handling. */
+
+extern jmp_buf tcpd_buf;
+
+/* Delimiters for lists of daemons or clients. */
+
+static char sep[] = ", \t\r\n";
+
+/* Constants to be used in assignments only, not in comparisons... */
+
+#define YES 1
+#define NO 0
+
+ /*
+ * These variables are globally visible so that they can be redirected in
+ * verification mode.
+ */
+
+char *hosts_allow_table = HOSTS_ALLOW;
+char *hosts_deny_table = HOSTS_DENY;
+int hosts_access_verbose = 0;
+
+ /*
+ * In a long-running process, we are not at liberty to just go away.
+ */
+
+int resident = (-1); /* -1, 0: unknown; +1: yes */
+
+/* Forward declarations. */
+
+static int table_match();
+static int list_match();
+static int server_match();
+static int client_match();
+static int host_match();
+static int string_match();
+static int masked_match();
+
+/* Size of logical line buffer. */
+
+#define BUFLEN 2048
+
+/* hosts_access - host access control facility */
+
+int hosts_access(request)
+struct request_info *request;
+{
+ int verdict;
+
+ /*
+ * If the (daemon, client) pair is matched by an entry in the file
+ * /etc/hosts.allow, access is granted. Otherwise, if the (daemon,
+ * client) pair is matched by an entry in the file /etc/hosts.deny,
+ * access is denied. Otherwise, access is granted. A non-existent
+ * access-control file is treated as an empty file.
+ *
+ * After a rule has been matched, the optional language extensions may
+ * decide to grant or refuse service anyway. Or, while a rule is being
+ * processed, a serious error is found, and it seems better to play safe
+ * and deny service. All this is done by jumping back into the
+ * hosts_access() routine, bypassing the regular return from the
+ * table_match() function calls below.
+ */
+
+ if (resident <= 0)
+ resident++;
+ verdict = setjmp(tcpd_buf);
+ if (verdict != 0)
+ return (verdict == AC_PERMIT);
+ if (table_match(hosts_allow_table, request))
+ return (YES);
+ if (table_match(hosts_deny_table, request))
+ return (NO);
+ return (YES);
+}
+
+/* table_match - match table entries with (daemon, client) pair */
+
+static int table_match(table, request)
+char *table;
+struct request_info *request;
+{
+ FILE *fp;
+ char sv_list[BUFLEN]; /* becomes list of daemons */
+ char *cl_list; /* becomes list of clients */
+ char *sh_cmd; /* becomes optional shell command */
+ int match = NO;
+ struct tcpd_context saved_context;
+
+ saved_context = tcpd_context; /* stupid compilers */
+
+ /*
+ * Between the fopen() and fclose() calls, avoid jumps that may cause
+ * file descriptor leaks.
+ */
+
+ if ((fp = fopen(table, "r")) != 0) {
+ tcpd_context.file = table;
+ tcpd_context.line = 0;
+ while (match == NO && xgets(sv_list, sizeof(sv_list), fp) != 0) {
+ if (sv_list[strlen(sv_list) - 1] != '\n') {
+ tcpd_warn("missing newline or line too long");
+ continue;
+ }
+ if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0)
+ continue;
+ if ((cl_list = split_at(sv_list, ':')) == 0) {
+ tcpd_warn("missing \":\" separator");
+ continue;
+ }
+ sh_cmd = split_at(cl_list, ':');
+ match = list_match(sv_list, request, server_match)
+ && list_match(cl_list, request, client_match);
+ }
+ (void) fclose(fp);
+ } else if (errno != ENOENT) {
+ tcpd_warn("cannot open %s: %m", table);
+ }
+ if (match) {
+ if (hosts_access_verbose > 1)
+ syslog(LOG_DEBUG, "matched: %s line %d",
+ tcpd_context.file, tcpd_context.line);
+ if (sh_cmd) {
+#ifdef PROCESS_OPTIONS
+ process_options(sh_cmd, request);
+#else
+ char cmd[BUFSIZ];
+ shell_cmd(percent_x(cmd, sizeof(cmd), sh_cmd, request));
+#endif
+ }
+ }
+ tcpd_context = saved_context;
+ return (match);
+}
+
+/* list_match - match a request against a list of patterns with exceptions */
+
+static int list_match(list, request, match_fn)
+char *list;
+struct request_info *request;
+int (*match_fn) ();
+{
+ char *tok;
+
+ /*
+ * Process tokens one at a time. We have exhausted all possible matches
+ * when we reach an "EXCEPT" token or the end of the list. If we do find
+ * a match, look for an "EXCEPT" list and recurse to determine whether
+ * the match is affected by any exceptions.
+ */
+
+ for (tok = strtok(list, sep); tok != 0; tok = strtok((char *) 0, sep)) {
+ if (STR_EQ(tok, "EXCEPT")) /* EXCEPT: give up */
+ return (NO);
+ if (match_fn(tok, request)) { /* YES: look for exceptions */
+ while ((tok = strtok((char *) 0, sep)) && STR_NE(tok, "EXCEPT"))
+ /* VOID */ ;
+ return (tok == 0 || list_match((char *) 0, request, match_fn) == 0);
+ }
+ }
+ return (NO);
+}
+
+/* server_match - match server information */
+
+static int server_match(tok, request)
+char *tok;
+struct request_info *request;
+{
+ char *host;
+
+ if ((host = split_at(tok + 1, '@')) == 0) { /* plain daemon */
+ return (string_match(tok, eval_daemon(request)));
+ } else { /* daemon@host */
+ return (string_match(tok, eval_daemon(request))
+ && host_match(host, request->server));
+ }
+}
+
+/* client_match - match client information */
+
+static int client_match(tok, request)
+char *tok;
+struct request_info *request;
+{
+ char *host;
+
+ if ((host = split_at(tok + 1, '@')) == 0) { /* plain host */
+ return (host_match(tok, request->client));
+ } else { /* user@host */
+ return (host_match(host, request->client)
+ && string_match(tok, eval_user(request)));
+ }
+}
+
+/* host_match - match host name and/or address against pattern */
+
+static int host_match(tok, host)
+char *tok;
+struct host_info *host;
+{
+ char *mask;
+
+ /*
+ * This code looks a little hairy because we want to avoid unnecessary
+ * hostname lookups.
+ *
+ * The KNOWN pattern requires that both address AND name be known; some
+ * patterns are specific to host names or to host addresses; all other
+ * patterns are satisfied when either the address OR the name match.
+ */
+
+ if (tok[0] == '@') { /* netgroup: look it up */
+#ifdef NETGROUP
+ static char *mydomain = 0;
+ if (mydomain == 0)
+ yp_get_default_domain(&mydomain);
+ return (innetgr(tok + 1, eval_hostname(host), (char *) 0, mydomain));
+#else
+ tcpd_warn("netgroup support is disabled"); /* not tcpd_jump() */
+ return (NO);
+#endif
+ } else if (STR_EQ(tok, "KNOWN")) { /* check address and name */
+ char *name = eval_hostname(host);
+ return (STR_NE(eval_hostaddr(host), unknown) && HOSTNAME_KNOWN(name));
+ } else if (STR_EQ(tok, "LOCAL")) { /* local: no dots in name */
+ char *name = eval_hostname(host);
+ return (strchr(name, '.') == 0 && HOSTNAME_KNOWN(name));
+ } else if ((mask = split_at(tok, '/')) != 0) { /* net/mask */
+ return (masked_match(tok, mask, eval_hostaddr(host)));
+ } else { /* anything else */
+ return (string_match(tok, eval_hostaddr(host))
+ || (NOT_INADDR(tok) && string_match(tok, eval_hostname(host))));
+ }
+}
+
+/* string_match - match string against pattern */
+
+static int string_match(tok, string)
+char *tok;
+char *string;
+{
+ int n;
+
+ if (tok[0] == '.') { /* suffix */
+ n = strlen(string) - strlen(tok);
+ return (n > 0 && STR_EQ(tok, string + n));
+ } else if (STR_EQ(tok, "ALL")) { /* all: match any */
+ return (YES);
+ } else if (STR_EQ(tok, "KNOWN")) { /* not unknown */
+ return (STR_NE(string, unknown));
+ } else if (tok[(n = strlen(tok)) - 1] == '.') { /* prefix */
+ return (STRN_EQ(tok, string, n));
+ } else { /* exact match */
+ return (STR_EQ(tok, string));
+ }
+}
+
+/* masked_match - match address against netnumber/netmask */
+
+static int masked_match(net_tok, mask_tok, string)
+char *net_tok;
+char *mask_tok;
+char *string;
+{
+ unsigned long net;
+ unsigned long mask;
+ unsigned long addr;
+
+ /*
+ * Disallow forms other than dotted quad: the treatment that inet_addr()
+ * gives to forms with less than four components is inconsistent with the
+ * access control language. John P. Rouillard <rouilj@cs.umb.edu>.
+ */
+
+ if ((addr = dot_quad_addr(string)) == INADDR_NONE)
+ return (NO);
+ if ((net = dot_quad_addr(net_tok)) == INADDR_NONE
+ || (mask = dot_quad_addr(mask_tok)) == INADDR_NONE) {
+ tcpd_warn("bad net/mask expression: %s/%s", net_tok, mask_tok);
+ return (NO); /* not tcpd_jump() */
+ }
+ return ((addr & mask) == net);
+}
--- /dev/null
+/* $OpenBSD: hosts_ctl.c,v 1.1 1997/02/26 03:06:53 downsj Exp $ */
+
+ /*
+ * hosts_ctl() combines common applications of the host access control
+ * library routines. It bundles its arguments then calls the hosts_access()
+ * access control checker. The host name and user name arguments should be
+ * empty strings, STRING_UNKNOWN or real data. If a match is found, the
+ * optional shell command is executed.
+ *
+ * Restriction: this interface does not pass enough information to support
+ * selective remote username lookups or selective hostname double checks.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) hosts_ctl.c 1.4 94/12/28 17:42:27";
+#else
+static char rcsid[] = "$OpenBSD: hosts_ctl.c,v 1.1 1997/02/26 03:06:53 downsj Exp $";
+#endif
+#endif
+
+#include <stdio.h>
+
+#include "tcpd.h"
+
+/* hosts_ctl - limited interface to the hosts_access() routine */
+
+int hosts_ctl(daemon, name, addr, user)
+char *daemon;
+char *name;
+char *addr;
+char *user;
+{
+ struct request_info request;
+
+ return (hosts_access(request_init(&request,
+ RQ_DAEMON, daemon,
+ RQ_CLIENT_NAME, name,
+ RQ_CLIENT_ADDR, addr,
+ RQ_USER, user,
+ 0)));
+}
--- /dev/null
+.\" $OpenBSD: hosts_options.5,v 1.1 1997/02/26 03:06:53 downsj Exp $
+.TH HOSTS_OPTIONS 5
+.SH NAME
+hosts_options \- host access control language extensions
+.SH DESCRIPTION
+This document describes optional extensions to the language described
+in the hosts_access(5) document. The extensions are enabled at program
+build time. For example, by editing the Makefile and turning on the
+PROCESS_OPTIONS compile-time option.
+.PP
+The extensible language uses the following format:
+.sp
+.ti +3
+daemon_list : client_list : option : option ...
+.PP
+The first two fields are described in the hosts_access(5) manual page.
+The remainder of the rules is a list of zero or more options. Any ":"
+characters within options should be protected with a backslash.
+.PP
+An option is of the form "keyword" or "keyword value". Options are
+processed in the specified order. Some options are subjected to
+%<letter> substitutions. For the sake of backwards compatibility with
+earlier versions, an "=" is permitted between keyword and value.
+.SH LOGGING
+.IP "severity mail.info"
+.IP "severity notice"
+Change the severity level at which the event will be logged. Facility
+names (such as mail) are optional, and are not supported on systems
+with older syslog implementations. The severity option can be used
+to emphasize or to ignore specific events.
+.SH ACCESS CONTROL
+.IP "allow"
+.IP "deny"
+Grant (deny) service. These options must appear at the end of a rule.
+.PP
+The \fIallow\fR and \fIdeny\fR keywords make it possible to keep all
+access control rules within a single file, for example in the
+\fIhosts.allow\fR file.
+.sp
+To permit access from specific hosts only:
+.sp
+.ne 2
+.ti +3
+ALL: .friendly.domain: ALLOW
+.ti +3
+ALL: ALL: DENY
+.sp
+To permit access from all hosts except a few trouble makers:
+.sp
+.ne 2
+.ti +3
+ALL: .bad.domain: DENY
+.ti +3
+ALL: ALL: ALLOW
+.sp
+Notice the leading dot on the domain name patterns.
+.SH RUNNING OTHER COMMANDS
+.IP "spawn shell_command"
+Execute, in a child process, the specified shell command, after
+performing the %<letter> expansions described in the hosts_access(5)
+manual page. The command is executed with stdin, stdout and stderr
+connected to the null device, so that it won\'t mess up the
+conversation with the client host. Example:
+.sp
+.nf
+.ti +3
+spawn (/some/where/safe_finger -l @%h | /usr/ucb/mail root) &
+.fi
+.sp
+executes, in a background child process, the shell command "safe_finger
+-l @%h | mail root" after replacing %h by the name or address of the
+remote host.
+.sp
+The example uses the "safe_finger" command instead of the regular
+"finger" command, to limit possible damage from data sent by the finger
+server. The "safe_finger" command is part of the daemon wrapper
+package; it is a wrapper around the regular finger command that filters
+the data sent by the remote host.
+.IP "twist shell_command"
+Replace the current process by an instance of the specified shell
+command, after performing the %<letter> expansions described in the
+hosts_access(5) manual page. Stdin, stdout and stderr are connected to
+the client process. This option must appear at the end of a rule.
+.sp
+To send a customized bounce message to the client instead of
+running the real ftp daemon:
+.sp
+.nf
+.ti +3
+in.ftpd : ... : twist /bin/echo 421 Some bounce message
+.fi
+.sp
+For an alternative way to talk to client processes, see the
+\fIbanners\fR option below.
+.sp
+To run /some/other/in.telnetd without polluting its command-line
+array or its process environment:
+.sp
+.nf
+.ti +3
+in.telnetd : ... : twist PATH=/some/other; exec in.telnetd
+.fi
+.sp
+Warning: in case of UDP services, do not twist to commands that use
+the standard I/O or the read(2)/write(2) routines to communicate with
+the client process; UDP requires other I/O primitives.
+.SH NETWORK OPTIONS
+.IP "keepalive"
+Causes the server to periodically send a message to the client. The
+connection is considered broken when the client does not respond. The
+keepalive option can be useful when users turn off their machine while
+it is still connected to a server. The keepalive option is not useful
+for datagram (UDP) services.
+.IP "linger number_of_seconds"
+Specifies how long the kernel will try to deliver not-yet delivered
+data after the server process closes a connection.
+.SH USERNAME LOOKUP
+.IP "rfc931 [ timeout_in_seconds ]"
+Look up the client user name with the RFC 931 (TAP, IDENT, RFC 1413)
+protocol. This option is silently ignored in case of services based on
+transports other than TCP. It requires that the client system runs an
+RFC 931 (IDENT, etc.) -compliant daemon, and may cause noticeable
+delays with connections from non-UNIX clients. The timeout period is
+optional. If no timeout is specified a compile-time defined default
+value is taken.
+.SH MISCELLANEOUS
+.IP "banners /some/directory"
+Look for a file in `/some/directory' with the same name as the daemon
+process (for example in.telnetd for the telnet service), and copy its
+contents to the client. Newline characters are replaced by
+carriage-return newline, and %<letter> sequences are expanded (see
+the hosts_access(5) manual page).
+.sp
+The tcp wrappers source code distribution provides a sample makefile
+(Banners.Makefile) for convenient banner maintenance.
+.sp
+Warning: banners are supported for connection-oriented (TCP) network
+services only.
+.IP "nice [ number ]"
+Change the nice value of the process (default 10). Specify a positive
+value to spend more CPU resources on other processes.
+.IP "setenv name value"
+Place a (name, value) pair into the process environment. The value is
+subjected to %<letter> expansions and may contain whitespace (but
+leading and trailing blanks are stripped off).
+.sp
+Warning: many network daemons reset their environment before spawning a
+login or shell process.
+.IP "umask 022"
+Like the umask command that is built into the shell. An umask of 022
+prevents the creation of files with group and world write permission.
+The umask argument should be an octal number.
+.IP "user nobody"
+.IP "user nobody.kmem"
+Assume the privileges of the "nobody" userid (or user "nobody", group
+"kmem"). The first form is useful with inetd implementations that run
+all services with root privilege. The second form is useful for
+services that need special group privileges only.
+.SH DIAGNOSTICS
+When a syntax error is found in an access control rule, the error
+is reported to the syslog daemon; further options will be ignored,
+and service is denied.
+.SH SEE ALSO
+hosts_access(5), the default access control language
+.SH AUTHOR
+.na
+.nf
+Wietse Venema (wietse@wzv.win.tue.nl)
+Department of Mathematics and Computing Science
+Eindhoven University of Technology
+Den Dolech 2, P.O. Box 513,
+5600 MB Eindhoven, The Netherlands
+\" @(#) hosts_options.5 1.10 94/12/28 17:42:28
--- /dev/null
+/* $OpenBSD: misc.c,v 1.1 1997/02/26 03:06:53 downsj Exp $ */
+
+ /*
+ * Misc routines that are used by tcpd and by tcpdchk.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsic[] = "@(#) misc.c 1.2 96/02/11 17:01:29";
+#else
+static char rcsid[] = "$OpenBSD: misc.c,v 1.1 1997/02/26 03:06:53 downsj Exp $";
+#endif
+#endif
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "tcpd.h"
+
+#ifndef INADDR_NONE
+#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
+#endif
+
+/* xgets - fgets() with backslash-newline stripping */
+
+char *xgets(ptr, len, fp)
+char *ptr;
+int len;
+FILE *fp;
+{
+ int got;
+ char *start = ptr;
+
+ while (fgets(ptr, len, fp)) {
+ got = strlen(ptr);
+ if (got >= 1 && ptr[got - 1] == '\n') {
+ tcpd_context.line++;
+ if (got >= 2 && ptr[got - 2] == '\\') {
+ got -= 2;
+ } else {
+ return (start);
+ }
+ }
+ ptr += got;
+ len -= got;
+ ptr[0] = 0;
+ }
+ return (ptr > start ? start : 0);
+}
+
+/* split_at - break string at delimiter or return NULL */
+
+char *split_at(string, delimiter)
+char *string;
+int delimiter;
+{
+ char *cp;
+
+ if ((cp = strchr(string, delimiter)) != 0)
+ *cp++ = 0;
+ return (cp);
+}
+
+/* dot_quad_addr - convert dotted quad to internal form */
+
+unsigned long dot_quad_addr(str)
+char *str;
+{
+ int in_run = 0;
+ int runs = 0;
+ char *cp = str;
+
+ /* Count the number of runs of non-dot characters. */
+
+ while (*cp) {
+ if (*cp == '.') {
+ in_run = 0;
+ } else if (in_run == 0) {
+ in_run = 1;
+ runs++;
+ }
+ cp++;
+ }
+ return (runs == 4 ? inet_addr(str) : INADDR_NONE);
+}
--- /dev/null
+/* $OpenBSD: options.c,v 1.1 1997/02/26 03:06:54 downsj Exp $ */
+
+ /*
+ * General skeleton for adding options to the access control language. The
+ * features offered by this module are documented in the hosts_options(5)
+ * manual page (source file: hosts_options.5, "nroff -man" format).
+ *
+ * Notes and warnings for those who want to add features:
+ *
+ * In case of errors, abort options processing and deny access. There are too
+ * many irreversible side effects to make error recovery feasible. For
+ * example, it makes no sense to continue after we have already changed the
+ * userid.
+ *
+ * In case of errors, do not terminate the process: the routines might be
+ * called from a long-running daemon that should run forever. Instead, call
+ * tcpd_jump() which does a non-local goto back into the hosts_access()
+ * routine.
+ *
+ * In case of severe errors, use clean_exit() instead of directly calling
+ * exit(), or the inetd may loop on an UDP request.
+ *
+ * In verification mode (for example, with the "tcpdmatch" command) the
+ * "dry_run" flag is set. In this mode, an option function should just "say"
+ * what it is going to do instead of really doing it.
+ *
+ * Some option functions do not return (for example, the twist option passes
+ * control to another program). In verification mode (dry_run flag is set)
+ * such options should clear the "dry_run" flag to inform the caller of this
+ * course of action.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) options.c 1.17 96/02/11 17:01:31";
+#else
+static char rcsid[] = "$OpenBSD: options.c,v 1.1 1997/02/26 03:06:54 downsj Exp $";
+#endif
+#endif
+
+/* System libraries. */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <syslog.h>
+#include <pwd.h>
+#include <grp.h>
+#include <ctype.h>
+#include <setjmp.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifndef MAXPATHNAMELEN
+#define MAXPATHNAMELEN BUFSIZ
+#endif
+
+/* Local stuff. */
+
+#include "tcpd.h"
+
+/* Options runtime support. */
+
+int dry_run = 0; /* flag set in verification mode */
+extern jmp_buf tcpd_buf; /* tcpd_jump() support */
+
+/* Options parser support. */
+
+static char whitespace_eq[] = "= \t\r\n";
+#define whitespace (whitespace_eq + 1)
+
+static char *get_field(); /* chew :-delimited field off string */
+static char *chop_string(); /* strip leading and trailing blanks */
+
+/* List of functions that implement the options. Add yours here. */
+
+static void user_option(); /* execute "user name.group" option */
+static void group_option(); /* execute "group name" option */
+static void umask_option(); /* execute "umask mask" option */
+static void linger_option(); /* execute "linger time" option */
+static void keepalive_option(); /* execute "keepalive" option */
+static void spawn_option(); /* execute "spawn command" option */
+static void twist_option(); /* execute "twist command" option */
+static void rfc931_option(); /* execute "rfc931" option */
+static void setenv_option(); /* execute "setenv name value" */
+static void nice_option(); /* execute "nice" option */
+static void severity_option(); /* execute "severity value" */
+static void allow_option(); /* execute "allow" option */
+static void deny_option(); /* execute "deny" option */
+static void banners_option(); /* execute "banners path" option */
+
+/* Structure of the options table. */
+
+struct option {
+ char *name; /* keyword name, case is ignored */
+ void (*func) (); /* function that does the real work */
+ int flags; /* see below... */
+};
+
+#define NEED_ARG (1<<1) /* option requires argument */
+#define USE_LAST (1<<2) /* option must be last */
+#define OPT_ARG (1<<3) /* option has optional argument */
+#define EXPAND_ARG (1<<4) /* do %x expansion on argument */
+
+#define need_arg(o) ((o)->flags & NEED_ARG)
+#define opt_arg(o) ((o)->flags & OPT_ARG)
+#define permit_arg(o) ((o)->flags & (NEED_ARG | OPT_ARG))
+#define use_last(o) ((o)->flags & USE_LAST)
+#define expand_arg(o) ((o)->flags & EXPAND_ARG)
+
+/* List of known keywords. Add yours here. */
+
+static struct option option_table[] = {
+ "user", user_option, NEED_ARG,
+ "group", group_option, NEED_ARG,
+ "umask", umask_option, NEED_ARG,
+ "linger", linger_option, NEED_ARG,
+ "keepalive", keepalive_option, 0,
+ "spawn", spawn_option, NEED_ARG | EXPAND_ARG,
+ "twist", twist_option, NEED_ARG | EXPAND_ARG | USE_LAST,
+ "rfc931", rfc931_option, OPT_ARG,
+ "setenv", setenv_option, NEED_ARG | EXPAND_ARG,
+ "nice", nice_option, OPT_ARG,
+ "severity", severity_option, NEED_ARG,
+ "allow", allow_option, USE_LAST,
+ "deny", deny_option, USE_LAST,
+ "banners", banners_option, NEED_ARG,
+ 0,
+};
+
+/* process_options - process access control options */
+
+void process_options(options, request)
+char *options;
+struct request_info *request;
+{
+ char *key;
+ char *value;
+ char *curr_opt;
+ char *next_opt;
+ struct option *op;
+ char bf[BUFSIZ];
+
+ for (curr_opt = get_field(options); curr_opt; curr_opt = next_opt) {
+ next_opt = get_field((char *) 0);
+
+ /*
+ * Separate the option into name and value parts. For backwards
+ * compatibility we ignore exactly one '=' between name and value.
+ */
+ curr_opt = chop_string(curr_opt);
+ if (*(value = curr_opt + strcspn(curr_opt, whitespace_eq))) {
+ if (*value != '=') {
+ *value++ = 0;
+ value += strspn(value, whitespace);
+ }
+ if (*value == '=') {
+ *value++ = 0;
+ value += strspn(value, whitespace);
+ }
+ }
+ if (*value == 0)
+ value = 0;
+ key = curr_opt;
+
+ /*
+ * Disallow missing option names (and empty option fields).
+ */
+ if (*key == 0)
+ tcpd_jump("missing option name");
+
+ /*
+ * Lookup the option-specific info and do some common error checks.
+ * Delegate option-specific processing to the specific functions.
+ */
+
+ for (op = option_table; op->name && STR_NE(op->name, key); op++)
+ /* VOID */ ;
+ if (op->name == 0)
+ tcpd_jump("bad option name: \"%s\"", key);
+ if (!value && need_arg(op))
+ tcpd_jump("option \"%s\" requires value", key);
+ if (value && !permit_arg(op))
+ tcpd_jump("option \"%s\" requires no value", key);
+ if (next_opt && use_last(op))
+ tcpd_jump("option \"%s\" must be at end", key);
+ if (value && expand_arg(op))
+ value = chop_string(percent_x(bf, sizeof(bf), value, request));
+ if (hosts_access_verbose)
+ syslog(LOG_DEBUG, "option: %s %s", key, value ? value : "");
+ (*(op->func)) (value, request);
+ }
+}
+
+/* allow_option - grant access */
+
+/* ARGSUSED */
+
+static void allow_option(value, request)
+char *value;
+struct request_info *request;
+{
+ longjmp(tcpd_buf, AC_PERMIT);
+}
+
+/* deny_option - deny access */
+
+/* ARGSUSED */
+
+static void deny_option(value, request)
+char *value;
+struct request_info *request;
+{
+ longjmp(tcpd_buf, AC_DENY);
+}
+
+/* banners_option - expand %<char>, terminate each line with CRLF */
+
+static void banners_option(value, request)
+char *value;
+struct request_info *request;
+{
+ char path[MAXPATHNAMELEN];
+ char ibuf[BUFSIZ];
+ char obuf[2 * BUFSIZ];
+ struct stat st;
+ int ch;
+ FILE *fp;
+
+ sprintf(path, "%s/%s", value, eval_daemon(request));
+ if ((fp = fopen(path, "r")) != 0) {
+ while ((ch = fgetc(fp)) == 0)
+ write(request->fd, "", 1);
+ ungetc(ch, fp);
+ while (fgets(ibuf, sizeof(ibuf) - 1, fp)) {
+ if (split_at(ibuf, '\n'))
+ strcat(ibuf, "\r\n");
+ percent_x(obuf, sizeof(obuf), ibuf, request);
+ write(request->fd, obuf, strlen(obuf));
+ }
+ fclose(fp);
+ } else if (stat(value, &st) < 0) {
+ tcpd_warn("%s: %m", value);
+ }
+}
+
+/* group_option - switch group id */
+
+/* ARGSUSED */
+
+static void group_option(value, request)
+char *value;
+struct request_info *request;
+{
+ struct group *grp;
+ struct group *getgrnam();
+
+ if ((grp = getgrnam(value)) == 0)
+ tcpd_jump("unknown group: \"%s\"", value);
+ endgrent();
+
+ if (dry_run == 0 && setgid(grp->gr_gid))
+ tcpd_jump("setgid(%s): %m", value);
+}
+
+/* user_option - switch user id */
+
+/* ARGSUSED */
+
+static void user_option(value, request)
+char *value;
+struct request_info *request;
+{
+ struct passwd *pwd;
+ struct passwd *getpwnam();
+ char *group;
+
+ if ((group = split_at(value, '.')) != 0)
+ group_option(group, request);
+ if ((pwd = getpwnam(value)) == 0)
+ tcpd_jump("unknown user: \"%s\"", value);
+ endpwent();
+
+ if (dry_run == 0 && setuid(pwd->pw_uid))
+ tcpd_jump("setuid(%s): %m", value);
+}
+
+/* umask_option - set file creation mask */
+
+/* ARGSUSED */
+
+static void umask_option(value, request)
+char *value;
+struct request_info *request;
+{
+ unsigned mask;
+ char junk;
+
+ if (sscanf(value, "%o%c", &mask, &junk) != 1 || (mask & 0777) != mask)
+ tcpd_jump("bad umask value: \"%s\"", value);
+ (void) umask(mask);
+}
+
+/* spawn_option - spawn a shell command and wait */
+
+/* ARGSUSED */
+
+static void spawn_option(value, request)
+char *value;
+struct request_info *request;
+{
+ if (dry_run == 0)
+ shell_cmd(value);
+}
+
+/* linger_option - set the socket linger time (Marc Boucher <marc@cam.org>) */
+
+/* ARGSUSED */
+
+static void linger_option(value, request)
+char *value;
+struct request_info *request;
+{
+ struct linger linger;
+ char junk;
+
+ if (sscanf(value, "%d%c", &linger.l_linger, &junk) != 1
+ || linger.l_linger < 0)
+ tcpd_jump("bad linger value: \"%s\"", value);
+ if (dry_run == 0) {
+ linger.l_onoff = (linger.l_linger != 0);
+ if (setsockopt(request->fd, SOL_SOCKET, SO_LINGER, (char *) &linger,
+ sizeof(linger)) < 0)
+ tcpd_warn("setsockopt SO_LINGER %d: %m", linger.l_linger);
+ }
+}
+
+/* keepalive_option - set the socket keepalive option */
+
+/* ARGSUSED */
+
+static void keepalive_option(value, request)
+char *value;
+struct request_info *request;
+{
+ static int on = 1;
+
+ if (dry_run == 0 && setsockopt(request->fd, SOL_SOCKET, SO_KEEPALIVE,
+ (char *) &on, sizeof(on)) < 0)
+ tcpd_warn("setsockopt SO_KEEPALIVE: %m");
+}
+
+/* nice_option - set nice value */
+
+/* ARGSUSED */
+
+static void nice_option(value, request)
+char *value;
+struct request_info *request;
+{
+ int niceval = 10;
+ char junk;
+
+ if (value != 0 && sscanf(value, "%d%c", &niceval, &junk) != 1)
+ tcpd_jump("bad nice value: \"%s\"", value);
+ if (dry_run == 0 && nice(niceval) < 0)
+ tcpd_warn("nice(%d): %m", niceval);
+}
+
+/* twist_option - replace process by shell command */
+
+static void twist_option(value, request)
+char *value;
+struct request_info *request;
+{
+ char *error;
+
+ if (dry_run != 0) {
+ dry_run = 0;
+ } else {
+ if (resident > 0)
+ tcpd_jump("twist option in resident process");
+
+ syslog(deny_severity, "twist %s to %s", eval_client(request), value);
+
+ /* Before switching to the shell, set up stdin, stdout and stderr. */
+
+#define maybe_dup2(from, to) ((from == to) ? to : (close(to), dup(from)))
+
+ if (maybe_dup2(request->fd, 0) != 0 ||
+ maybe_dup2(request->fd, 1) != 1 ||
+ maybe_dup2(request->fd, 2) != 2) {
+ error = "twist_option: dup: %m";
+ } else {
+ if (request->fd > 2)
+ close(request->fd);
+ (void) execl("/bin/sh", "sh", "-c", value, (char *) 0);
+ error = "twist_option: /bin/sh: %m";
+ }
+
+ /* Something went wrong: we MUST terminate the process. */
+
+ tcpd_warn(error);
+ clean_exit(request);
+ }
+}
+
+/* rfc931_option - look up remote user name */
+
+static void rfc931_option(value, request)
+char *value;
+struct request_info *request;
+{
+ int timeout;
+ char junk;
+
+ if (value != 0) {
+ if (sscanf(value, "%d%c", &timeout, &junk) != 1 || timeout <= 0)
+ tcpd_jump("bad rfc931 timeout: \"%s\"", value);
+ rfc931_timeout = timeout;
+ }
+ (void) eval_user(request);
+}
+
+/* setenv_option - set environment variable */
+
+/* ARGSUSED */
+
+static void setenv_option(value, request)
+char *value;
+struct request_info *request;
+{
+ char *var_value;
+
+ if (*(var_value = value + strcspn(value, whitespace)))
+ *var_value++ = 0;
+ if (setenv(chop_string(value), chop_string(var_value), 1))
+ tcpd_jump("memory allocation failure");
+}
+
+ /*
+ * The severity option goes last because it comes with a huge amount of ugly
+ * #ifdefs and tables.
+ */
+
+struct syslog_names {
+ char *name;
+ int value;
+};
+
+static struct syslog_names log_fac[] = {
+#ifdef LOG_KERN
+ "kern", LOG_KERN,
+#endif
+#ifdef LOG_USER
+ "user", LOG_USER,
+#endif
+#ifdef LOG_MAIL
+ "mail", LOG_MAIL,
+#endif
+#ifdef LOG_DAEMON
+ "daemon", LOG_DAEMON,
+#endif
+#ifdef LOG_AUTH
+ "auth", LOG_AUTH,
+#endif
+#ifdef LOG_LPR
+ "lpr", LOG_LPR,
+#endif
+#ifdef LOG_NEWS
+ "news", LOG_NEWS,
+#endif
+#ifdef LOG_UUCP
+ "uucp", LOG_UUCP,
+#endif
+#ifdef LOG_CRON
+ "cron", LOG_CRON,
+#endif
+#ifdef LOG_LOCAL0
+ "local0", LOG_LOCAL0,
+#endif
+#ifdef LOG_LOCAL1
+ "local1", LOG_LOCAL1,
+#endif
+#ifdef LOG_LOCAL2
+ "local2", LOG_LOCAL2,
+#endif
+#ifdef LOG_LOCAL3
+ "local3", LOG_LOCAL3,
+#endif
+#ifdef LOG_LOCAL4
+ "local4", LOG_LOCAL4,
+#endif
+#ifdef LOG_LOCAL5
+ "local5", LOG_LOCAL5,
+#endif
+#ifdef LOG_LOCAL6
+ "local6", LOG_LOCAL6,
+#endif
+#ifdef LOG_LOCAL7
+ "local7", LOG_LOCAL7,
+#endif
+ 0,
+};
+
+static struct syslog_names log_sev[] = {
+#ifdef LOG_EMERG
+ "emerg", LOG_EMERG,
+#endif
+#ifdef LOG_ALERT
+ "alert", LOG_ALERT,
+#endif
+#ifdef LOG_CRIT
+ "crit", LOG_CRIT,
+#endif
+#ifdef LOG_ERR
+ "err", LOG_ERR,
+#endif
+#ifdef LOG_WARNING
+ "warning", LOG_WARNING,
+#endif
+#ifdef LOG_NOTICE
+ "notice", LOG_NOTICE,
+#endif
+#ifdef LOG_INFO
+ "info", LOG_INFO,
+#endif
+#ifdef LOG_DEBUG
+ "debug", LOG_DEBUG,
+#endif
+ 0,
+};
+
+/* severity_map - lookup facility or severity value */
+
+static int severity_map(table, name)
+struct syslog_names *table;
+char *name;
+{
+ struct syslog_names *t;
+
+ for (t = table; t->name; t++)
+ if (STR_EQ(t->name, name))
+ return (t->value);
+ tcpd_jump("bad syslog facility or severity: \"%s\"", name);
+ /* NOTREACHED */
+}
+
+/* severity_option - change logging severity for this event (Dave Mitchell) */
+
+/* ARGSUSED */
+
+static void severity_option(value, request)
+char *value;
+struct request_info *request;
+{
+ char *level = split_at(value, '.');
+
+ allow_severity = deny_severity = level ?
+ severity_map(log_fac, value) | severity_map(log_sev, level) :
+ severity_map(log_sev, value);
+}
+
+/* get_field - return pointer to next field in string */
+
+static char *get_field(string)
+char *string;
+{
+ static char *last = "";
+ char *src;
+ char *dst;
+ char *ret;
+ int ch;
+
+ /*
+ * This function returns pointers to successive fields within a given
+ * string. ":" is the field separator; warn if the rule ends in one. It
+ * replaces a "\:" sequence by ":", without treating the result of
+ * substitution as field terminator. A null argument means resume search
+ * where the previous call terminated. This function destroys its
+ * argument.
+ *
+ * Work from explicit source or from memory. While processing \: we
+ * overwrite the input. This way we do not have to maintain buffers for
+ * copies of input fields.
+ */
+
+ src = dst = ret = (string ? string : last);
+ if (src[0] == 0)
+ return (0);
+
+ while ((ch = *src)) {
+ if (ch == ':') {
+ if (*++src == 0)
+ tcpd_warn("rule ends in \":\"");
+ break;
+ }
+ if (ch == '\\' && src[1] == ':')
+ src++;
+ *dst++ = *src++;
+ }
+ last = src;
+ *dst = 0;
+ return (ret);
+}
+
+/* chop_string - strip leading and trailing blanks from string */
+
+static char *chop_string(string)
+register char *string;
+{
+ char *start = 0;
+ char *end;
+ char *cp;
+
+ for (cp = string; *cp; cp++) {
+ if (!isspace(*cp)) {
+ if (start == 0)
+ start = cp;
+ end = cp;
+ }
+ }
+ return (start ? (end[1] = 0, start) : cp);
+}
--- /dev/null
+/* $OpenBSD: percent_m.c,v 1.1 1997/02/26 03:06:54 downsj Exp $ */
+
+ /*
+ * Replace %m by system error message.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) percent_m.c 1.1 94/12/28 17:42:37";
+#else
+static char rcsid[] = "$OpenBSD: percent_m.c,v 1.1 1997/02/26 03:06:54 downsj Exp $";
+#endif
+#endif
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <string.h>
+
+extern int errno;
+#ifndef SYS_ERRLIST_DEFINED
+extern char *sys_errlist[];
+extern int sys_nerr;
+#endif
+
+char *percent_m(obuf, ibuf)
+char *obuf;
+char *ibuf;
+{
+ char *bp = obuf;
+ char *cp = ibuf;
+
+ while ((*bp = *cp)) {
+ if (*cp == '%' && cp[1] == 'm') {
+ if (errno < sys_nerr && errno > 0) {
+ strcpy(bp, sys_errlist[errno]);
+ } else {
+ sprintf(bp, "Unknown error %d", errno);
+ }
+ bp += strlen(bp);
+ cp += 2;
+ } else {
+ bp++, cp++;
+ }
+ }
+ return (obuf);
+}
--- /dev/null
+/* $OpenBSD: percent_x.c,v 1.1 1997/02/26 03:06:55 downsj Exp $ */
+
+ /*
+ * percent_x() takes a string and performs %<char> expansions. It aborts the
+ * program when the expansion would overflow the output buffer. The result
+ * of %<char> expansion may be passed on to a shell process. For this
+ * reason, characters with a special meaning to shells are replaced by
+ * underscores.
+ *
+ * Diagnostics are reported through syslog(3).
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) percent_x.c 1.4 94/12/28 17:42:37";
+#else
+static char rcsid[] = "$OpenBSD: percent_x.c,v 1.1 1997/02/26 03:06:55 downsj Exp $";
+#endif
+#endif
+
+/* System libraries. */
+
+#include <stdio.h>
+#include <syslog.h>
+#include <string.h>
+#include <unistd.h>
+
+/* Local stuff. */
+
+#include "tcpd.h"
+
+/* percent_x - do %<char> expansion, abort if result buffer is too small */
+
+char *percent_x(result, result_len, string, request)
+char *result;
+int result_len;
+char *string;
+struct request_info *request;
+{
+ char *bp = result;
+ char *end = result + result_len - 1; /* end of result buffer */
+ char *expansion;
+ int expansion_len;
+ static char ok_chars[] = "1234567890!@%-_=+:,./\
+abcdefghijklmnopqrstuvwxyz\
+ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+ char *str = string;
+ char *cp;
+ int ch;
+
+ /*
+ * Warning: we may be called from a child process or after pattern
+ * matching, so we cannot use clean_exit() or tcpd_jump().
+ */
+
+ while (*str) {
+ if (*str == '%' && (ch = str[1]) != 0) {
+ str += 2;
+ expansion =
+ ch == 'a' ? eval_hostaddr(request->client) :
+ ch == 'A' ? eval_hostaddr(request->server) :
+ ch == 'c' ? eval_client(request) :
+ ch == 'd' ? eval_daemon(request) :
+ ch == 'h' ? eval_hostinfo(request->client) :
+ ch == 'H' ? eval_hostinfo(request->server) :
+ ch == 'n' ? eval_hostname(request->client) :
+ ch == 'N' ? eval_hostname(request->server) :
+ ch == 'p' ? eval_pid(request) :
+ ch == 's' ? eval_server(request) :
+ ch == 'u' ? eval_user(request) :
+ ch == '%' ? "%" : (tcpd_warn("unrecognized %%%c", ch), "");
+ for (cp = expansion; *(cp += strspn(cp, ok_chars)); /* */ )
+ *cp = '_';
+ expansion_len = cp - expansion;
+ } else {
+ expansion = str++;
+ expansion_len = 1;
+ }
+ if (bp + expansion_len >= end) {
+ tcpd_warn("percent_x: expansion too long: %.30s...", result);
+ sleep(5);
+ exit(0);
+ }
+ memcpy(bp, expansion, expansion_len);
+ bp += expansion_len;
+ }
+ *bp = 0;
+ return (result);
+}
--- /dev/null
+/* $OpenBSD: refuse.c,v 1.1 1997/02/26 03:06:55 downsj Exp $ */
+
+ /*
+ * refuse() reports a refused connection, and takes the consequences: in
+ * case of a datagram-oriented service, the unread datagram is taken from
+ * the input queue (or inetd would see the same datagram again and again);
+ * the program is terminated.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) refuse.c 1.5 94/12/28 17:42:39";
+#else
+static char rcsid[] = "$OpenBSD: refuse.c,v 1.1 1997/02/26 03:06:55 downsj Exp $";
+#endif
+#endif
+
+/* System libraries. */
+
+#include <stdio.h>
+#include <syslog.h>
+
+/* Local stuff. */
+
+#include "tcpd.h"
+
+/* refuse - refuse request */
+
+void refuse(request)
+struct request_info *request;
+{
+ syslog(deny_severity, "refused connect from %s", eval_client(request));
+ clean_exit(request);
+ /* NOTREACHED */
+}
+
--- /dev/null
+/* $OpenBSD: rfc931.c,v 1.1 1997/02/26 03:06:56 downsj Exp $ */
+
+ /*
+ * rfc931() speaks a common subset of the RFC 931, AUTH, TAP, IDENT and RFC
+ * 1413 protocols. It queries an RFC 931 etc. compatible daemon on a remote
+ * host to look up the owner of a connection. The information should not be
+ * used for authentication purposes. This routine intercepts alarm signals.
+ *
+ * Diagnostics are reported through syslog(3).
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) rfc931.c 1.10 95/01/02 16:11:34";
+#else
+static char rcsid[] = "$OpenBSD: rfc931.c,v 1.1 1997/02/26 03:06:56 downsj Exp $";
+#endif
+#endif
+
+/* System libraries. */
+
+#include <stdio.h>
+#include <syslog.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <setjmp.h>
+#include <signal.h>
+#include <string.h>
+#include <unistd.h>
+
+/* Local stuff. */
+
+#include "tcpd.h"
+
+#define RFC931_PORT 113 /* Semi-well-known port */
+#define ANY_PORT 0 /* Any old port will do */
+
+int rfc931_timeout = RFC931_TIMEOUT;/* Global so it can be changed */
+
+static jmp_buf timebuf;
+
+/* fsocket - open stdio stream on top of socket */
+
+static FILE *fsocket(domain, type, protocol)
+int domain;
+int type;
+int protocol;
+{
+ int s;
+ FILE *fp;
+
+ if ((s = socket(domain, type, protocol)) < 0) {
+ tcpd_warn("socket: %m");
+ return (0);
+ } else {
+ if ((fp = fdopen(s, "r+")) == 0) {
+ tcpd_warn("fdopen: %m");
+ close(s);
+ }
+ return (fp);
+ }
+}
+
+/* timeout - handle timeouts */
+
+static void timeout(sig)
+int sig;
+{
+ longjmp(timebuf, sig);
+}
+
+/* rfc931 - return remote user name, given socket structures */
+
+void rfc931(rmt_sin, our_sin, dest)
+struct sockaddr_in *rmt_sin;
+struct sockaddr_in *our_sin;
+char *dest;
+{
+ unsigned rmt_port;
+ unsigned our_port;
+ struct sockaddr_in rmt_query_sin;
+ struct sockaddr_in our_query_sin;
+ char user[256]; /* XXX */
+ char buffer[512]; /* XXX */
+ char *cp;
+ char *result = unknown;
+ FILE *fp;
+
+ /*
+ * Use one unbuffered stdio stream for writing to and for reading from
+ * the RFC931 etc. server. This is done because of a bug in the SunOS
+ * 4.1.x stdio library. The bug may live in other stdio implementations,
+ * too. When we use a single, buffered, bidirectional stdio stream ("r+"
+ * or "w+" mode) we read our own output. Such behaviour would make sense
+ * with resources that support random-access operations, but not with
+ * sockets.
+ */
+
+ if ((fp = fsocket(AF_INET, SOCK_STREAM, 0)) != 0) {
+ setbuf(fp, (char *) 0);
+
+ /*
+ * Set up a timer so we won't get stuck while waiting for the server.
+ */
+
+ if (setjmp(timebuf) == 0) {
+ signal(SIGALRM, timeout);
+ alarm(rfc931_timeout);
+
+ /*
+ * Bind the local and remote ends of the query socket to the same
+ * IP addresses as the connection under investigation. We go
+ * through all this trouble because the local or remote system
+ * might have more than one network address. The RFC931 etc.
+ * client sends only port numbers; the server takes the IP
+ * addresses from the query socket.
+ */
+
+ our_query_sin = *our_sin;
+ our_query_sin.sin_port = htons(ANY_PORT);
+ rmt_query_sin = *rmt_sin;
+ rmt_query_sin.sin_port = htons(RFC931_PORT);
+
+ if (bind(fileno(fp), (struct sockaddr *) & our_query_sin,
+ sizeof(our_query_sin)) >= 0 &&
+ connect(fileno(fp), (struct sockaddr *) & rmt_query_sin,
+ sizeof(rmt_query_sin)) >= 0) {
+
+ /*
+ * Send query to server. Neglect the risk that a 13-byte
+ * write would have to be fragmented by the local system and
+ * cause trouble with buggy System V stdio libraries.
+ */
+
+ fprintf(fp, "%u,%u\r\n",
+ ntohs(rmt_sin->sin_port),
+ ntohs(our_sin->sin_port));
+ fflush(fp);
+
+ /*
+ * Read response from server. Use fgets()/sscanf() so we can
+ * work around System V stdio libraries that incorrectly
+ * assume EOF when a read from a socket returns less than
+ * requested.
+ */
+
+ if (fgets(buffer, sizeof(buffer), fp) != 0
+ && ferror(fp) == 0 && feof(fp) == 0
+ && sscanf(buffer, "%u , %u : USERID :%*[^:]:%255s",
+ &rmt_port, &our_port, user) == 3
+ && ntohs(rmt_sin->sin_port) == rmt_port
+ && ntohs(our_sin->sin_port) == our_port) {
+
+ /*
+ * Strip trailing carriage return. It is part of the
+ * protocol, not part of the data.
+ */
+
+ cp = strchr(user, '\r');
+ if (cp)
+ *cp = 0;
+ result = user;
+ }
+ }
+ alarm(0);
+ }
+ fclose(fp);
+ }
+ STRN_CPY(dest, result, STRING_LENGTH);
+}
--- /dev/null
+/* $OpenBSD: scaffold.c,v 1.1 1997/02/26 03:06:56 downsj Exp $ */
+
+ /*
+ * Routines for testing only. Not really industrial strength.
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccs_id[] = "@(#) scaffold.c 1.5 95/01/03 09:13:48";
+#else
+static char rcsid[] = "$OpenBSD: scaffold.c,v 1.1 1997/02/26 03:06:56 downsj 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>
+
+#ifndef INADDR_NONE
+#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
+#endif
+
+extern char *malloc();
+
+/* Application-specific. */
+
+#include "tcpd.h"
+#include "scaffold.h"
+
+ /*
+ * These are referenced by the options module and by rfc931.c.
+ */
+int allow_severity = SEVERITY;
+int deny_severity = LOG_WARNING;
+int rfc931_timeout = RFC931_TIMEOUT;
+
+/* dup_hostent - create hostent in one memory block */
+
+static struct hostent *dup_hostent(hp)
+struct hostent *hp;
+{
+ struct hostent_block {
+ struct hostent host;
+ char *addr_list[1];
+ };
+ struct hostent_block *hb;
+ int count;
+ char *data;
+ char *addr;
+
+ for (count = 0; hp->h_addr_list[count] != 0; count++)
+ /* void */ ;
+
+ if ((hb = (struct hostent_block *) malloc(sizeof(struct hostent_block)
+ + (hp->h_length + sizeof(char *)) * count)) == 0) {
+ fprintf(stderr, "Sorry, out of memory\n");
+ exit(1);
+ }
+ memset((char *) &hb->host, 0, sizeof(hb->host));
+ hb->host.h_length = hp->h_length;
+ hb->host.h_addr_list = hb->addr_list;
+ hb->host.h_addr_list[count] = 0;
+ data = (char *) (hb->host.h_addr_list + count + 1);
+
+ for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
+ hb->host.h_addr_list[count] = data + hp->h_length * count;
+ memcpy(hb->host.h_addr_list[count], addr, hp->h_length);
+ }
+ return (&hb->host);
+}
+
+/* find_inet_addr - find all addresses for this host, result to free() */
+
+struct hostent *find_inet_addr(host)
+char *host;
+{
+ struct in_addr addr;
+ struct hostent *hp;
+ static struct hostent h;
+ static char *addr_list[2];
+
+ /*
+ * Host address: translate it to internal form.
+ */
+ if ((addr.s_addr = dot_quad_addr(host)) != INADDR_NONE) {
+ h.h_addr_list = addr_list;
+ h.h_addr_list[0] = (char *) &addr;
+ h.h_length = sizeof(addr);
+ return (dup_hostent(&h));
+ }
+
+ /*
+ * Map host name to a series of addresses. Watch out for non-internet
+ * forms or aliases. The NOT_INADDR() is here in case gethostbyname() has
+ * been "enhanced" to accept numeric addresses. Make a copy of the
+ * address list so that later gethostbyXXX() calls will not clobber it.
+ */
+ if (NOT_INADDR(host) == 0) {
+ tcpd_warn("%s: not an internet address", host);
+ return (0);
+ }
+ if ((hp = gethostbyname(host)) == 0) {
+ tcpd_warn("%s: host not found", host);
+ return (0);
+ }
+ if (hp->h_addrtype != AF_INET) {
+ tcpd_warn("%d: not an internet host", hp->h_addrtype);
+ return (0);
+ }
+ if (STR_NE(host, hp->h_name)) {
+ tcpd_warn("%s: hostname alias", host);
+ tcpd_warn("(official name: %s)", hp->h_name);
+ }
+ return (dup_hostent(hp));
+}
+
+/* check_dns - give each address thorough workout, return address count */
+
+int check_dns(host)
+char *host;
+{
+ struct request_info request;
+ struct sockaddr_in sin;
+ struct hostent *hp;
+ int count;
+ char *addr;
+
+ if ((hp = find_inet_addr(host)) == 0)
+ return (0);
+ request_init(&request, RQ_CLIENT_SIN, &sin, 0);
+ sock_methods(&request);
+ memset((char *) &sin, 0, sizeof(sin));
+ sin.sin_family = AF_INET;
+
+ for (count = 0; (addr = hp->h_addr_list[count]) != 0; count++) {
+ memcpy((char *) &sin.sin_addr, addr, sizeof(sin.sin_addr));
+
+ /*
+ * Force host name and address conversions. Use the request structure
+ * as a cache. Detect hostname lookup problems. Any name/name or
+ * name/address conflicts will be reported while eval_hostname() does
+ * its job.
+ */
+ request_set(&request, RQ_CLIENT_ADDR, "", RQ_CLIENT_NAME, "", 0);
+ if (STR_EQ(eval_hostname(request.client), unknown))
+ tcpd_warn("host address %s->name lookup failed",
+ eval_hostaddr(request.client));
+ }
+ free((char *) hp);
+ return (count);
+}
+
+/* dummy function to intercept the real shell_cmd() */
+
+/* ARGSUSED */
+
+void shell_cmd(command)
+char *command;
+{
+ if (hosts_access_verbose)
+ printf("command: %s", command);
+}
+
+/* dummy function to intercept the real clean_exit() */
+
+/* ARGSUSED */
+
+void clean_exit(request)
+struct request_info *request;
+{
+ exit(0);
+}
+
+/* dummy function to intercept the real rfc931() */
+
+/* ARGSUSED */
+
+void rfc931(request)
+struct request_info *request;
+{
+ strcpy(request->user, unknown);
+}
+
+/* check_path - examine accessibility */
+
+int check_path(path, st)
+char *path;
+struct stat *st;
+{
+ struct stat stbuf;
+ char buf[BUFSIZ];
+
+ if (stat(path, st) < 0)
+ return (-1);
+#ifdef notdef
+ if (st->st_uid != 0)
+ tcpd_warn("%s: not owned by root", path);
+ if (st->st_mode & 020)
+ tcpd_warn("%s: group writable", path);
+#endif
+ if (st->st_mode & 002)
+ tcpd_warn("%s: world writable", path);
+ if (path[0] == '/' && path[1] != 0) {
+ strrchr(strcpy(buf, path), '/')[0] = 0;
+ (void) check_path(buf[0] ? buf : "/", &stbuf);
+ }
+ return (0);
+}
--- /dev/null
+/* $OpenBSD: scaffold.h,v 1.1 1997/02/26 03:06:57 downsj Exp $ */
+
+ /*
+ * @(#) scaffold.h 1.3 94/12/31 18:19:19
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+extern struct hostent *find_inet_addr __P((char *));
+extern int check_dns __P((char *));
+extern int check_path __P((char *, struct stat *));
+__END_DECLS
--- /dev/null
+/* $OpenBSD: shell_cmd.c,v 1.1 1997/02/26 03:06:57 downsj Exp $ */
+
+ /*
+ * shell_cmd() takes a shell command after %<character> substitutions. The
+ * command is executed by a /bin/sh child process, with standard input,
+ * standard output and standard error connected to /dev/null.
+ *
+ * Diagnostics are reported through syslog(3).
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) shell_cmd.c 1.5 94/12/28 17:42:44";
+#else
+static char rcsid[] = "$OpenBSD: shell_cmd.c,v 1.1 1997/02/26 03:06:57 downsj Exp $";
+#endif
+#endif
+
+/* System libraries. */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <stdio.h>
+#include <syslog.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+/* Local stuff. */
+
+#include "tcpd.h"
+
+/* Forward declarations. */
+
+static void do_child();
+
+/* shell_cmd - execute shell command */
+
+void shell_cmd(command)
+char *command;
+{
+ int child_pid;
+ int wait_pid;
+
+ /*
+ * Most of the work is done within the child process, to minimize the
+ * risk of damage to the parent.
+ */
+
+ switch (child_pid = fork()) {
+ case -1: /* error */
+ tcpd_warn("cannot fork: %m");
+ break;
+ case 00: /* child */
+ do_child(command);
+ /* NOTREACHED */
+ default: /* parent */
+ while ((wait_pid = wait((int *) 0)) != -1 && wait_pid != child_pid)
+ /* void */ ;
+ }
+}
+
+/* do_child - exec command with { stdin, stdout, stderr } to /dev/null */
+
+static void do_child(command)
+char *command;
+{
+ char *error;
+ int tmp_fd;
+
+ /*
+ * Systems with POSIX sessions may send a SIGHUP to grandchildren if the
+ * child exits first. This is sick, sessions were invented for terminals.
+ */
+
+ signal(SIGHUP, SIG_IGN);
+
+ /* Set up new stdin, stdout, stderr, and exec the shell command. */
+
+ for (tmp_fd = 0; tmp_fd < 3; tmp_fd++)
+ (void) close(tmp_fd);
+ if (open("/dev/null", O_RDWR) != 0) {
+ error = "open /dev/null: %m";
+ } else if (dup(0) != 1 || dup(0) != 2) {
+ error = "dup: %m";
+ } else {
+ (void) execl("/bin/sh", "sh", "-c", command, (char *) 0);
+ error = "execl /bin/sh: %m";
+ }
+
+ /* Something went wrong. We MUST terminate the child process. */
+
+ tcpd_warn(error);
+ _exit(0);
+}
--- /dev/null
+major=1
+minor=0
--- /dev/null
+/* $OpenBSD: socket.c,v 1.1 1997/02/26 03:06:58 downsj Exp $ */
+
+ /*
+ * This module determines the type of socket (datagram, stream), the client
+ * socket address and port, the server socket address and port. In addition,
+ * it provides methods to map a transport address to a printable host name
+ * or address. Socket address information results are in static memory.
+ *
+ * The result from the hostname lookup method is STRING_PARANOID when a host
+ * pretends to have someone elses name, or when a host name is available but
+ * could not be verified.
+ *
+ * When lookup or conversion fails the result is set to STRING_UNKNOWN.
+ *
+ * Diagnostics are reported through syslog(3).
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) socket.c 1.14 95/01/30 19:51:50";
+#else
+static char rcsid[] = "$OpenBSD: socket.c,v 1.1 1997/02/26 03:06:58 downsj Exp $";
+#endif
+#endif
+
+/* System libraries. */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <syslog.h>
+#include <string.h>
+
+/* Local stuff. */
+
+#include "tcpd.h"
+
+/* Forward declarations. */
+
+static void sock_sink();
+
+#ifdef APPEND_DOT
+
+ /*
+ * Speed up DNS lookups by terminating the host name with a dot. Should be
+ * done with care. The speedup can give problems with lookups from sources
+ * that lack DNS-style trailing dot magic, such as local files or NIS maps.
+ */
+
+static struct hostent *gethostbyname_dot(name)
+char *name;
+{
+ char dot_name[MAXHOSTNAMELEN + 1];
+
+ /*
+ * Don't append dots to unqualified names. Such names are likely to come
+ * from local hosts files or from NIS.
+ */
+
+ if (strchr(name, '.') == 0 || strlen(name) >= MAXHOSTNAMELEN - 1) {
+ return (gethostbyname(name));
+ } else {
+ sprintf(dot_name, "%s.", name);
+ return (gethostbyname(dot_name));
+ }
+}
+
+#define gethostbyname gethostbyname_dot
+#endif
+
+/* sock_host - look up endpoint addresses and install conversion methods */
+
+void sock_host(request)
+struct request_info *request;
+{
+ static struct sockaddr_in client;
+ static struct sockaddr_in server;
+ int len;
+ char buf[BUFSIZ];
+ int fd = request->fd;
+
+ sock_methods(request);
+
+ /*
+ * Look up the client host address. Hal R. Brand <BRAND@addvax.llnl.gov>
+ * suggested how to get the client host info in case of UDP connections:
+ * peek at the first message without actually looking at its contents. We
+ * really should verify that client.sin_family gets the value AF_INET,
+ * but this program has already caused too much grief on systems with
+ * broken library code.
+ */
+
+ len = sizeof(client);
+ if (getpeername(fd, (struct sockaddr *) & client, &len) < 0) {
+ request->sink = sock_sink;
+ len = sizeof(client);
+ if (recvfrom(fd, buf, sizeof(buf), MSG_PEEK,
+ (struct sockaddr *) & client, &len) < 0) {
+ tcpd_warn("can't get client address: %m");
+ return; /* give up */
+ }
+#ifdef really_paranoid
+ memset(buf, 0 sizeof(buf));
+#endif
+ }
+ request->client->sin = &client;
+
+ /*
+ * Determine the server binding. This is used for client username
+ * lookups, and for access control rules that trigger on the server
+ * address or name.
+ */
+
+ len = sizeof(server);
+ if (getsockname(fd, (struct sockaddr *) & server, &len) < 0) {
+ tcpd_warn("getsockname: %m");
+ return;
+ }
+ request->server->sin = &server;
+}
+
+/* sock_hostaddr - map endpoint address to printable form */
+
+void sock_hostaddr(host)
+struct host_info *host;
+{
+ struct sockaddr_in *sin = host->sin;
+
+ if (sin != 0)
+ STRN_CPY(host->addr, inet_ntoa(sin->sin_addr), sizeof(host->addr));
+}
+
+/* sock_hostname - map endpoint address to host name */
+
+void sock_hostname(host)
+struct host_info *host;
+{
+ struct sockaddr_in *sin = host->sin;
+ struct hostent *hp;
+ int i;
+
+ /*
+ * On some systems, for example Solaris 2.3, gethostbyaddr(0.0.0.0) does
+ * not fail. Instead it returns "INADDR_ANY". Unfortunately, this does
+ * not work the other way around: gethostbyname("INADDR_ANY") fails. We
+ * have to special-case 0.0.0.0, in order to avoid false alerts from the
+ * host name/address checking code below.
+ */
+ if (sin != 0 && sin->sin_addr.s_addr != 0
+ && (hp = gethostbyaddr((char *) &(sin->sin_addr),
+ sizeof(sin->sin_addr), AF_INET)) != 0) {
+
+ STRN_CPY(host->name, hp->h_name, sizeof(host->name));
+
+ /*
+ * Verify that the address is a member of the address list returned
+ * by gethostbyname(hostname).
+ *
+ * Verify also that gethostbyaddr() and gethostbyname() return the same
+ * hostname, or rshd and rlogind may still end up being spoofed.
+ *
+ * On some sites, gethostbyname("localhost") returns "localhost.domain".
+ * This is a DNS artefact. We treat it as a special case. When we
+ * can't believe the address list from gethostbyname("localhost")
+ * we're in big trouble anyway.
+ */
+
+ if ((hp = gethostbyname(host->name)) == 0) {
+
+ /*
+ * Unable to verify that the host name matches the address. This
+ * may be a transient problem or a botched name server setup.
+ */
+
+ tcpd_warn("can't verify hostname: gethostbyname(%s) failed",
+ host->name);
+
+ } else if (STR_NE(host->name, hp->h_name)
+ && STR_NE(host->name, "localhost")) {
+
+ /*
+ * The gethostbyaddr() and gethostbyname() calls did not return
+ * the same hostname. This could be a nameserver configuration
+ * problem. It could also be that someone is trying to spoof us.
+ */
+
+ tcpd_warn("host name/name mismatch: %s != %s",
+ host->name, hp->h_name);
+
+ } else {
+
+ /*
+ * The address should be a member of the address list returned by
+ * gethostbyname(). We should first verify that the h_addrtype
+ * field is AF_INET, but this program has already caused too much
+ * grief on systems with broken library code.
+ */
+
+ for (i = 0; hp->h_addr_list[i]; i++) {
+ if (memcmp(hp->h_addr_list[i],
+ (char *) &sin->sin_addr,
+ sizeof(sin->sin_addr)) == 0)
+ return; /* name is good, keep it */
+ }
+
+ /*
+ * The host name does not map to the initial address. Perhaps
+ * someone has messed up. Perhaps someone compromised a name
+ * server.
+ */
+
+ tcpd_warn("host name/address mismatch: %s != %s",
+ inet_ntoa(sin->sin_addr), hp->h_name);
+ }
+ strcpy(host->name, paranoid); /* name is bad, clobber it */
+ }
+}
+
+/* sock_sink - absorb unreceived IP datagram */
+
+static void sock_sink(fd)
+int fd;
+{
+ char buf[BUFSIZ];
+ struct sockaddr_in sin;
+ int size = sizeof(sin);
+
+ /*
+ * Eat up the not-yet received datagram. Some systems insist on a
+ * non-zero source address argument in the recvfrom() call below.
+ */
+
+ (void) recvfrom(fd, buf, sizeof(buf), 0, (struct sockaddr *) & sin, &size);
+}
--- /dev/null
+/* $OpenBSD: tcpd.h,v 1.1 1997/02/26 03:06:58 downsj Exp $ */
+
+/*
+ * Copyright (c) 1997, Jason Downs. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+ /*
+ * @(#) tcpd.h 1.5 96/03/19 16:22:24
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef _TCPD_H_
+#define _TCPD_H_
+
+#include <sys/cdefs.h>
+
+/* Structure to describe one communications endpoint. */
+
+#define STRING_LENGTH 128 /* hosts, users, processes */
+
+struct host_info {
+ char name[STRING_LENGTH]; /* access via eval_hostname(host) */
+ char addr[STRING_LENGTH]; /* access via eval_hostaddr(host) */
+ struct sockaddr_in *sin; /* socket address or 0 */
+ struct t_unitdata *unit; /* TLI transport address or 0 */
+ struct request_info *request; /* for shared information */
+};
+
+/* Structure to describe what we know about a service request. */
+
+struct request_info {
+ int fd; /* socket handle */
+ char user[STRING_LENGTH]; /* access via eval_user(request) */
+ char daemon[STRING_LENGTH]; /* access via eval_daemon(request) */
+ char pid[10]; /* access via eval_pid(request) */
+ struct host_info client[1]; /* client endpoint info */
+ struct host_info server[1]; /* server endpoint info */
+ void (*sink) (); /* datagram sink function or 0 */
+ void (*hostname) (); /* address to printable hostname */
+ void (*hostaddr) (); /* address to printable address */
+ void (*cleanup) (); /* cleanup function or 0 */
+ struct netconfig *config; /* netdir handle */
+};
+
+/* Common string operations. Less clutter should be more readable. */
+
+#define STRN_CPY(d,s,l) { strncpy((d),(s),(l)); (d)[(l)-1] = 0; }
+
+#define STRN_EQ(x,y,l) (strncasecmp((x),(y),(l)) == 0)
+#define STRN_NE(x,y,l) (strncasecmp((x),(y),(l)) != 0)
+#define STR_EQ(x,y) (strcasecmp((x),(y)) == 0)
+#define STR_NE(x,y) (strcasecmp((x),(y)) != 0)
+
+ /*
+ * Initially, all above strings have the empty value. Information that
+ * cannot be determined at runtime is set to "unknown", so that we can
+ * distinguish between `unavailable' and `not yet looked up'. A hostname
+ * that we do not believe in is set to "paranoid".
+ */
+
+#define STRING_UNKNOWN "unknown" /* lookup failed */
+#define STRING_PARANOID "paranoid" /* hostname conflict */
+
+__BEGIN_DECLS
+extern char unknown[];
+extern char paranoid[];
+__END_DECLS
+
+#define HOSTNAME_KNOWN(s) (STR_NE((s),unknown) && STR_NE((s),paranoid))
+
+#define NOT_INADDR(s) (s[strspn(s,"01234567890./")] != 0)
+
+/* Global functions. */
+
+#define fromhost sock_host /* no TLI support needed */
+
+__BEGIN_DECLS
+extern int hosts_access __P((struct request_info *));
+extern void shell_cmd __P((char *));
+extern char *percent_m __P((char *, char *));
+extern char *percent_x __P((char *, int, char *, struct request_info *));
+extern void rfc931 __P((struct sockaddr_in *, struct sockaddr_in *, char *));
+extern void clean_exit __P((struct request_info *));
+extern void refuse __P((struct request_info *));
+extern char *xgets __P((char *, int, FILE *));
+extern char *split_at __P((char *, int));
+extern unsigned long dot_quad_addr __P((char *));
+
+/* Global variables. */
+
+extern int allow_severity; /* for connection logging */
+extern int deny_severity; /* for connection logging */
+extern char *hosts_allow_table; /* for verification mode redirection */
+extern char *hosts_deny_table; /* for verification mode redirection */
+extern int hosts_access_verbose; /* for verbose matching mode */
+extern int rfc931_timeout; /* user lookup timeout */
+extern int resident; /* > 0 if resident process */
+
+ /*
+ * Routines for controlled initialization and update of request structure
+ * attributes. Each attribute has its own key.
+ */
+
+extern struct request_info *request_init __P((struct request_info *, ...));
+extern struct request_info *request_set __P((struct request_info *, ...));
+
+#define RQ_FILE 1 /* file descriptor */
+#define RQ_DAEMON 2 /* server process (argv[0]) */
+#define RQ_USER 3 /* client user name */
+#define RQ_CLIENT_NAME 4 /* client host name */
+#define RQ_CLIENT_ADDR 5 /* client host address */
+#define RQ_CLIENT_SIN 6 /* client endpoint (internal) */
+#define RQ_SERVER_NAME 7 /* server host name */
+#define RQ_SERVER_ADDR 8 /* server host address */
+#define RQ_SERVER_SIN 9 /* server endpoint (internal) */
+
+ /*
+ * Routines for delayed evaluation of request attributes. Each attribute
+ * type has its own access method. The trivial ones are implemented by
+ * macros. The other ones are wrappers around the transport-specific host
+ * name, address, and client user lookup methods. The request_info and
+ * host_info structures serve as caches for the lookup results.
+ */
+
+extern char *eval_user __P((struct request_info *));
+extern char *eval_hostname __P((struct host_info *));
+extern char *eval_hostaddr __P((struct host_info *));
+extern char *eval_hostinfo __P((struct host_info *));
+extern char *eval_client __P((struct request_info *));
+extern char *eval_server __P((struct request_info *));
+#define eval_daemon(r) ((r)->daemon) /* daemon process name */
+#define eval_pid(r) ((r)->pid) /* process id */
+
+/* Socket-specific methods, including DNS hostname lookups. */
+
+extern void sock_host __P((struct request_info *));
+extern void sock_hostname __P((struct host_info *));
+extern void sock_hostaddr __P((struct host_info *));
+#define sock_methods(r) \
+ { (r)->hostname = sock_hostname; (r)->hostaddr = sock_hostaddr; }
+
+ /*
+ * Problem reporting interface. Additional file/line context is reported
+ * when available. The jump buffer (tcpd_buf) is not declared here, or
+ * everyone would have to include <setjmp.h>.
+ */
+
+extern void tcpd_warn __P((char *, ...));
+extern void tcpd_jump __P((char *, ...));
+__END_DECLS
+
+struct tcpd_context {
+ char *file; /* current file */
+ int line; /* current line */
+};
+
+__BEGIN_DECLS
+extern struct tcpd_context tcpd_context;
+
+ /*
+ * While processing access control rules, error conditions are handled by
+ * jumping back into the hosts_access() routine. This is cleaner than
+ * checking the return value of each and every silly little function. The
+ * (-1) returns are here because zero is already taken by longjmp().
+ */
+
+#define AC_PERMIT 1 /* permit access */
+#define AC_DENY (-1) /* deny_access */
+#define AC_ERROR AC_DENY /* XXX */
+
+ /*
+ * In verification mode an option function should just say what it would do,
+ * instead of really doing it. An option function that would not return
+ * should clear the dry_run flag to inform the caller of this unusual
+ * behavior.
+ */
+
+extern void process_options __P((char *, struct request_info *));
+extern int dry_run; /* verification flag */
+__END_DECLS
+
+
+ /*
+ * What follows is an attempt to unify varargs.h and stdarg.h. I'd rather
+ * have this than #ifdefs all over the code.
+ *
+ * The code using these must include the proper system header.
+ */
+
+#ifdef __STDC__
+#define VARARGS(func,type,arg) func(type arg, ...)
+#define VASTART(ap,type,name) va_start(ap,name)
+#define VAEND(ap) va_end(ap)
+#else
+#define VARARGS(func,type,arg) func(va_alist) va_dcl
+#define VASTART(ap,type,name) {type name; va_start(ap); name = va_arg(ap, type)
+#define VAEND(ap) va_end(ap);}
+#endif
+
+#endif /* _TCPD_H_ */
--- /dev/null
+/* $OpenBSD: update.c,v 1.1 1997/02/26 03:06:59 downsj Exp $ */
+
+ /*
+ * Routines for controlled update/initialization of request structures.
+ *
+ * request_init() initializes its argument. Pointers and string-valued members
+ * are initialized to zero, to indicate that no lookup has been attempted.
+ *
+ * request_set() adds information to an already initialized request structure.
+ *
+ * Both functions take a variable-length name-value list.
+ *
+ * Diagnostics are reported through syslog(3).
+ *
+ * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+ */
+
+#ifndef lint
+#if 0
+static char sccsid[] = "@(#) update.c 1.1 94/12/28 17:42:56";
+#else
+static char rcsid[] = "$OpenBSD: update.c,v 1.1 1997/02/26 03:06:59 downsj Exp $";
+#endif
+#endif
+
+/* System libraries */
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <syslog.h>
+#include <string.h>
+#include <unistd.h>
+
+/* Local stuff. */
+
+#include "tcpd.h"
+
+/* request_fill - request update engine */
+
+static struct request_info *request_fill(request, ap)
+struct request_info *request;
+va_list ap;
+{
+ int key;
+ char *ptr;
+
+ while ((key = va_arg(ap, int)) > 0) {
+ switch (key) {
+ default:
+ tcpd_warn("request_fill: invalid key: %d", key);
+ return (request);
+ case RQ_FILE:
+ request->fd = va_arg(ap, int);
+ continue;
+ case RQ_CLIENT_SIN:
+ request->client->sin = va_arg(ap, struct sockaddr_in *);
+ continue;
+ case RQ_SERVER_SIN:
+ request->server->sin = va_arg(ap, struct sockaddr_in *);
+ continue;
+
+ /*
+ * All other fields are strings with the same maximal length.
+ */
+
+ case RQ_DAEMON:
+ ptr = request->daemon;
+ break;
+ case RQ_USER:
+ ptr = request->user;
+ break;
+ case RQ_CLIENT_NAME:
+ ptr = request->client->name;
+ break;
+ case RQ_CLIENT_ADDR:
+ ptr = request->client->addr;
+ break;
+ case RQ_SERVER_NAME:
+ ptr = request->server->name;
+ break;
+ case RQ_SERVER_ADDR:
+ ptr = request->server->addr;
+ break;
+ }
+ STRN_CPY(ptr, va_arg(ap, char *), STRING_LENGTH);
+ }
+ return (request);
+}
+
+/* request_init - initialize request structure */
+
+struct request_info *VARARGS(request_init, struct request_info *, request)
+{
+ static struct request_info default_info;
+ struct request_info *r;
+ va_list ap;
+
+ /*
+ * Initialize data members. We do not assign default function pointer
+ * members, to avoid pulling in the whole socket module when it is not
+ * really needed.
+ */
+ VASTART(ap, struct request_info *, request);
+ *request = default_info;
+ request->fd = -1;
+ strcpy(request->daemon, unknown);
+ sprintf(request->pid, "%d", getpid());
+ request->client->request = request;
+ request->server->request = request;
+ r = request_fill(request, ap);
+ VAEND(ap);
+ return (r);
+}
+
+/* request_set - update request structure */
+
+struct request_info *VARARGS(request_set, struct request_info *, request)
+{
+ struct request_info *r;
+ va_list ap;
+
+ VASTART(ap, struct request_info *, request);
+ r = request_fill(request, ap);
+ VAEND(ap);
+ return (r);
+}
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