130 lines
3.3 KiB
C
130 lines
3.3 KiB
C
/*
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* General front end for stream and datagram IP services. This program logs
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* the remote host name and then invokes the real daemon. For example,
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* install as /usr/etc/{tftpd,fingerd,telnetd,ftpd,rlogind,rshd,rexecd},
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* after saving the real daemons in the directory specified with the
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* REAL_DAEMON_DIR macro. This arrangement requires that the network daemons
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* are started by inetd or something similar. Connections and diagnostics
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* are logged through syslog(3).
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*
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* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
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*/
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#ifndef lint
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static char sccsid[] = "@(#) tcpd.c 1.10 96/02/11 17:01:32";
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#endif
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/* System libraries. */
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <stdio.h>
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#include <syslog.h>
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#include <string.h>
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#ifndef MAXPATHNAMELEN
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#define MAXPATHNAMELEN BUFSIZ
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#endif
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#ifndef STDIN_FILENO
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#define STDIN_FILENO 0
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#endif
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/* Local stuff. */
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#include "patchlevel.h"
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#include "tcpd.h"
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int allow_severity = SEVERITY; /* run-time adjustable */
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int deny_severity = LOG_WARNING; /* ditto */
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main(argc, argv)
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int argc;
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char **argv;
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{
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struct request_info request;
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char path[MAXPATHNAMELEN];
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/* Attempt to prevent the creation of world-writable files. */
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#ifdef DAEMON_UMASK
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umask(DAEMON_UMASK);
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#endif
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/*
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* If argv[0] is an absolute path name, ignore REAL_DAEMON_DIR, and strip
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* argv[0] to its basename.
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*/
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if (argv[0][0] == '/') {
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strcpy(path, argv[0]);
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argv[0] = strrchr(argv[0], '/') + 1;
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} else {
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sprintf(path, "%s/%s", REAL_DAEMON_DIR, argv[0]);
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}
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/*
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* Open a channel to the syslog daemon. Older versions of openlog()
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* require only two arguments.
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*/
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#ifdef LOG_MAIL
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(void) openlog(argv[0], LOG_PID, FACILITY);
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#else
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(void) openlog(argv[0], LOG_PID);
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#endif
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/*
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* Find out the endpoint addresses of this conversation. Host name
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* lookups and double checks will be done on demand.
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*/
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request_init(&request, RQ_DAEMON, argv[0], RQ_FILE, STDIN_FILENO, 0);
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fromhost(&request);
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/*
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* Optionally look up and double check the remote host name. Sites
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* concerned with security may choose to refuse connections from hosts
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* that pretend to have someone elses host name.
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*/
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#ifdef PARANOID
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if (STR_EQ(eval_hostname(request.client), paranoid))
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refuse(&request);
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#endif
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/*
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* The BSD rlogin and rsh daemons that came out after 4.3 BSD disallow
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* socket options at the IP level. They do so for a good reason.
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* Unfortunately, we cannot use this with SunOS 4.1.x because the
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* getsockopt() system call can panic the system.
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*/
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#ifdef KILL_IP_OPTIONS
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fix_options(&request);
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#endif
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/*
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* Check whether this host can access the service in argv[0]. The
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* access-control code invokes optional shell commands as specified in
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* the access-control tables.
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*/
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#ifdef HOSTS_ACCESS
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if (!hosts_access(&request))
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refuse(&request);
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#endif
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/* Report request and invoke the real daemon program. */
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syslog(allow_severity, "connect from %s", eval_client(&request));
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closelog();
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(void) execv(path, argv);
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syslog(LOG_ERR, "error: cannot execute %s: %m", path);
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clean_exit(&request);
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/* NOTREACHED */
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}
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