1 files changed, 129 insertions, 0 deletions
diff --git a/tcpd.c b/tcpd.c
new file mode 100644
index 0000000..d865b9c
--- /dev/null
+++ b/tcpd.c
@@ -0,0 +1,129 @@
+ /*
+  * General front end for stream and datagram IP services. This program logs
+  * the remote host name and then invokes the real daemon. For example,
+  * install as /usr/etc/{tftpd,fingerd,telnetd,ftpd,rlogind,rshd,rexecd},
+  * after saving the real daemons in the directory specified with the
+  * REAL_DAEMON_DIR macro. This arrangement requires that the network daemons
+  * are started by inetd or something similar. Connections and diagnostics
+  * are logged through syslog(3).
+  * 
+  * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
+  */
+
+#ifndef lint
+static char sccsid[] = "@(#) tcpd.c 1.10 96/02/11 17:01:32";
+#endif
+
+/* System libraries. */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <syslog.h>
+#include <string.h>
+
+#ifndef MAXPATHNAMELEN
+#define MAXPATHNAMELEN	BUFSIZ
+#endif
+
+#ifndef STDIN_FILENO
+#define STDIN_FILENO	0
+#endif
+
+/* Local stuff. */
+
+#include "patchlevel.h"
+#include "tcpd.h"
+
+int     allow_severity = SEVERITY;	/* run-time adjustable */
+int     deny_severity = LOG_WARNING;	/* ditto */
+
+main(argc, argv)
+int     argc;
+char  **argv;
+{
+    struct request_info request;
+    char    path[MAXPATHNAMELEN];
+
+    /* Attempt to prevent the creation of world-writable files. */
+
+#ifdef DAEMON_UMASK
+    umask(DAEMON_UMASK);
+#endif
+
+    /*
+     * If argv[0] is an absolute path name, ignore REAL_DAEMON_DIR, and strip
+     * argv[0] to its basename.
+     */
+
+    if (argv[0][0] == '/') {
+	strcpy(path, argv[0]);
+	argv[0] = strrchr(argv[0], '/') + 1;
+    } else {
+	sprintf(path, "%s/%s", REAL_DAEMON_DIR, argv[0]);
+    }
+
+    /*
+     * Open a channel to the syslog daemon. Older versions of openlog()
+     * require only two arguments.
+     */
+
+#ifdef LOG_MAIL
+    (void) openlog(argv[0], LOG_PID, FACILITY);
+#else
+    (void) openlog(argv[0], LOG_PID);
+#endif
+
+    /*
+     * Find out the endpoint addresses of this conversation. Host name
+     * lookups and double checks will be done on demand.
+     */
+
+    request_init(&request, RQ_DAEMON, argv[0], RQ_FILE, STDIN_FILENO, 0);
+    fromhost(&request);
+
+    /*
+     * Optionally look up and double check the remote host name. Sites
+     * concerned with security may choose to refuse connections from hosts
+     * that pretend to have someone elses host name.
+     */
+
+#ifdef PARANOID
+    if (STR_EQ(eval_hostname(request.client), paranoid))
+	refuse(&request);
+#endif
+
+    /*
+     * The BSD rlogin and rsh daemons that came out after 4.3 BSD disallow
+     * socket options at the IP level. They do so for a good reason.
+     * Unfortunately, we cannot use this with SunOS 4.1.x because the
+     * getsockopt() system call can panic the system.
+     */
+
+#ifdef KILL_IP_OPTIONS
+    fix_options(&request);
+#endif
+
+    /*
+     * Check whether this host can access the service in argv[0]. The
+     * access-control code invokes optional shell commands as specified in
+     * the access-control tables.
+     */
+
+#ifdef HOSTS_ACCESS
+    if (!hosts_access(&request))
+	refuse(&request);
+#endif
+
+    /* Report request and invoke the real daemon program. */
+
+    syslog(allow_severity, "connect from %s", eval_client(&request));
+    closelog();
+    (void) execv(path, argv);
+    syslog(LOG_ERR, "error: cannot execute %s: %m", path);
+    clean_exit(&request);
+    /* NOTREACHED */
+}