1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * General front end for stream and datagram IP services. This program logs 3*0Sstevel@tonic-gate * the remote host name and then invokes the real daemon. For example, 4*0Sstevel@tonic-gate * install as /usr/etc/{tftpd,fingerd,telnetd,ftpd,rlogind,rshd,rexecd}, 5*0Sstevel@tonic-gate * after saving the real daemons in the directory specified with the 6*0Sstevel@tonic-gate * REAL_DAEMON_DIR macro. This arrangement requires that the network daemons 7*0Sstevel@tonic-gate * are started by inetd or something similar. Connections and diagnostics 8*0Sstevel@tonic-gate * are logged through syslog(3). 9*0Sstevel@tonic-gate * 10*0Sstevel@tonic-gate * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands. 11*0Sstevel@tonic-gate */ 12*0Sstevel@tonic-gate 13*0Sstevel@tonic-gate #ifndef lint 14*0Sstevel@tonic-gate static char sccsid[] = "@(#) tcpd.c 1.10 96/02/11 17:01:32"; 15*0Sstevel@tonic-gate #endif 16*0Sstevel@tonic-gate 17*0Sstevel@tonic-gate /* System libraries. */ 18*0Sstevel@tonic-gate 19*0Sstevel@tonic-gate #include <sys/types.h> 20*0Sstevel@tonic-gate #include <sys/param.h> 21*0Sstevel@tonic-gate #include <sys/stat.h> 22*0Sstevel@tonic-gate #include <sys/socket.h> 23*0Sstevel@tonic-gate #include <netinet/in.h> 24*0Sstevel@tonic-gate #include <stdio.h> 25*0Sstevel@tonic-gate #include <syslog.h> 26*0Sstevel@tonic-gate #include <string.h> 27*0Sstevel@tonic-gate 28*0Sstevel@tonic-gate #ifndef MAXPATHNAMELEN 29*0Sstevel@tonic-gate #define MAXPATHNAMELEN BUFSIZ 30*0Sstevel@tonic-gate #endif 31*0Sstevel@tonic-gate 32*0Sstevel@tonic-gate #ifndef STDIN_FILENO 33*0Sstevel@tonic-gate #define STDIN_FILENO 0 34*0Sstevel@tonic-gate #endif 35*0Sstevel@tonic-gate 36*0Sstevel@tonic-gate /* Local stuff. */ 37*0Sstevel@tonic-gate 38*0Sstevel@tonic-gate #include "patchlevel.h" 39*0Sstevel@tonic-gate #include "tcpd.h" 40*0Sstevel@tonic-gate 41*0Sstevel@tonic-gate int allow_severity = SEVERITY; /* run-time adjustable */ 42*0Sstevel@tonic-gate int deny_severity = LOG_WARNING; /* ditto */ 43*0Sstevel@tonic-gate 44*0Sstevel@tonic-gate main(argc, argv) 45*0Sstevel@tonic-gate int argc; 46*0Sstevel@tonic-gate char **argv; 47*0Sstevel@tonic-gate { 48*0Sstevel@tonic-gate struct request_info request; 49*0Sstevel@tonic-gate char path[MAXPATHNAMELEN]; 50*0Sstevel@tonic-gate 51*0Sstevel@tonic-gate /* Attempt to prevent the creation of world-writable files. */ 52*0Sstevel@tonic-gate 53*0Sstevel@tonic-gate #ifdef DAEMON_UMASK 54*0Sstevel@tonic-gate umask(DAEMON_UMASK); 55*0Sstevel@tonic-gate #endif 56*0Sstevel@tonic-gate 57*0Sstevel@tonic-gate /* 58*0Sstevel@tonic-gate * If argv[0] is an absolute path name, ignore REAL_DAEMON_DIR, and strip 59*0Sstevel@tonic-gate * argv[0] to its basename. 60*0Sstevel@tonic-gate */ 61*0Sstevel@tonic-gate 62*0Sstevel@tonic-gate if (argv[0][0] == '/') { 63*0Sstevel@tonic-gate strcpy(path, argv[0]); 64*0Sstevel@tonic-gate argv[0] = strrchr(argv[0], '/') + 1; 65*0Sstevel@tonic-gate } else { 66*0Sstevel@tonic-gate sprintf(path, "%s/%s", REAL_DAEMON_DIR, argv[0]); 67*0Sstevel@tonic-gate } 68*0Sstevel@tonic-gate 69*0Sstevel@tonic-gate /* 70*0Sstevel@tonic-gate * Open a channel to the syslog daemon. Older versions of openlog() 71*0Sstevel@tonic-gate * require only two arguments. 72*0Sstevel@tonic-gate */ 73*0Sstevel@tonic-gate 74*0Sstevel@tonic-gate #ifdef LOG_MAIL 75*0Sstevel@tonic-gate (void) openlog(argv[0], LOG_PID, FACILITY); 76*0Sstevel@tonic-gate #else 77*0Sstevel@tonic-gate (void) openlog(argv[0], LOG_PID); 78*0Sstevel@tonic-gate #endif 79*0Sstevel@tonic-gate 80*0Sstevel@tonic-gate /* 81*0Sstevel@tonic-gate * Find out the endpoint addresses of this conversation. Host name 82*0Sstevel@tonic-gate * lookups and double checks will be done on demand. 83*0Sstevel@tonic-gate */ 84*0Sstevel@tonic-gate 85*0Sstevel@tonic-gate request_init(&request, RQ_DAEMON, argv[0], RQ_FILE, STDIN_FILENO, 0); 86*0Sstevel@tonic-gate fromhost(&request); 87*0Sstevel@tonic-gate 88*0Sstevel@tonic-gate /* 89*0Sstevel@tonic-gate * Optionally look up and double check the remote host name. Sites 90*0Sstevel@tonic-gate * concerned with security may choose to refuse connections from hosts 91*0Sstevel@tonic-gate * that pretend to have someone elses host name. 92*0Sstevel@tonic-gate */ 93*0Sstevel@tonic-gate 94*0Sstevel@tonic-gate #ifdef PARANOID 95*0Sstevel@tonic-gate if (STR_EQ(eval_hostname(request.client), paranoid)) 96*0Sstevel@tonic-gate refuse(&request); 97*0Sstevel@tonic-gate #endif 98*0Sstevel@tonic-gate 99*0Sstevel@tonic-gate /* 100*0Sstevel@tonic-gate * The BSD rlogin and rsh daemons that came out after 4.3 BSD disallow 101*0Sstevel@tonic-gate * socket options at the IP level. They do so for a good reason. 102*0Sstevel@tonic-gate * Unfortunately, we cannot use this with SunOS 4.1.x because the 103*0Sstevel@tonic-gate * getsockopt() system call can panic the system. 104*0Sstevel@tonic-gate */ 105*0Sstevel@tonic-gate 106*0Sstevel@tonic-gate #ifdef KILL_IP_OPTIONS 107*0Sstevel@tonic-gate fix_options(&request); 108*0Sstevel@tonic-gate #endif 109*0Sstevel@tonic-gate 110*0Sstevel@tonic-gate /* 111*0Sstevel@tonic-gate * Check whether this host can access the service in argv[0]. The 112*0Sstevel@tonic-gate * access-control code invokes optional shell commands as specified in 113*0Sstevel@tonic-gate * the access-control tables. 114*0Sstevel@tonic-gate */ 115*0Sstevel@tonic-gate 116*0Sstevel@tonic-gate #ifdef HOSTS_ACCESS 117*0Sstevel@tonic-gate if (!hosts_access(&request)) 118*0Sstevel@tonic-gate refuse(&request); 119*0Sstevel@tonic-gate #endif 120*0Sstevel@tonic-gate 121*0Sstevel@tonic-gate /* Report request and invoke the real daemon program. */ 122*0Sstevel@tonic-gate 123*0Sstevel@tonic-gate syslog(allow_severity, "connect from %s", eval_client(&request)); 124*0Sstevel@tonic-gate closelog(); 125*0Sstevel@tonic-gate (void) execv(path, argv); 126*0Sstevel@tonic-gate syslog(LOG_ERR, "error: cannot execute %s: %m", path); 127*0Sstevel@tonic-gate clean_exit(&request); 128*0Sstevel@tonic-gate /* NOTREACHED */ 129*0Sstevel@tonic-gate } 130