/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1983 Regents of the University of California.\n\
 All rights reserved.\n";
#endif not lint

#ifndef lint
static	char sccsid[] = "@(#)inetd.c 1.1 94/10/31 SMI"; /* from UCB 5.7 8/19/86 */
#endif not lint

/*
 * Inetd - Internet super-server
 *
 * This program invokes all internet services as needed.
 * connection-oriented services are invoked each time a
 * connection is made, by creating a process.  This process
 * is passed the connection as file descriptor 0 and is
 * expected to do a getpeername to find out the source host
 * and port.
 *
 * Datagram oriented services are invoked when a datagram
 * arrives; a process is created and passed a pending message
 * on file descriptor 0.  Datagram servers may either connect
 * to their peer, freeing up the original socket for inetd
 * to receive further messages on, or ``take over the socket'',
 * processing all arriving datagrams and, eventually, timing
 * out.	 The first type of server is said to be ``multi-threaded'';
 * the second type of server ``single-threaded''. 
 *
 * Inetd uses a configuration file which is read at startup
 * and, possibly, at some later time in response to a hangup signal.
 * The configuration file is ``free format'' with fields given in the
 * order shown below.  Continuation lines for an entry must being with
 * a space or tab.  All fields must be present in each entry.
 *
 *	service name			must be in /etc/services
 *	socket type			stream/dgram/raw/rdm/seqpacket
 *	protocol			must be in /etc/protocols
 *	wait/nowait			single-threaded/multi-threaded
 *	user				user to run daemon as
 *	server program			full path name
 *	server program arguments	maximum of MAXARGS (5)
 *
 * for rpc services:
 *	service name/version		must be in /etc/rpc with version = 1-x
 *	socket type			stream/dgram/raw/rdm/seqpacket
 *	protocol			of the form rpc/protocol
 *	wait/nowait			single-threaded/multi-threaded
 *	user				user to run daemon as
 *	server program			full path name
 *	server program arguments	maximum of MAXARGS (5)
 *
 * Comment lines are indicated by a `#' in column 1.
 */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/resource.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <errno.h>
#include <stdio.h>
#include <signal.h>
#include <netdb.h>
#include <syslog.h>
#include <pwd.h>

#define	TOOMANY		40		/* don't start more than TOOMANY */
#define	CNT_INTVL	60		/* servers in CNT_INTVL sec. */
#define	RETRYTIME	(60*10)		/* retry after bind or server fail */

#define	SIGBLOCK	(sigmask(SIGCHLD)|sigmask(SIGHUP)|sigmask(SIGALRM))

extern	int errno;

void	reapchild(), retry(), config();
void	termserv();
void	unregister();

char	*index();
char	*malloc();
long	strtol();

int	debug = 0;
int	ndescriptors;
int	nsock, maxsock;
fd_set	allsock;
int	options;
int	timingout;
int	nservers = 0;
int	maxservers;
struct	servent *sp;

/*
 * Each service requires one file descriptor for the socket we listen on
 * for requests for that service.  We don't allow more services than
 * we can allocate file descriptors for.  OTHERDESCRIPTORS is the number
 * of descriptors needed for other purposes; this number was determined
 * experimentally.
 */
#define	OTHERDESCRIPTORS	8

/*
 * Additional information carried in various fields:
 *
 * If "se_wait" is neither 0 nor 1, it's the PID of the server process
 * currently running for that service.
 * If "se_fd" is -1, it means that the service could not be set up,
 * e.g. the entry for that service couldn't be found in "/etc/services".
 */
struct	servtab {
	char	*se_service;		/* name of service */
	int	se_socktype;		/* type of socket to use */
	char	*se_proto;		/* protocol used */
	char	se_isrpc;		/* service is RPC-based */
	char	se_checked;		/* looked at during merge */
	short	se_wait;		/* single threaded server */
	char	*se_user;		/* user name to run as */
	struct	biltin *se_bi;		/* if built-in, description */
	char	*se_server;		/* server program */
#define MAXARGV 5
	char	*se_argv[MAXARGV+1];	/* program arguments */
	int	se_fd;			/* open descriptor */
	union {
		struct	sockaddr_in ctrladdr;	/* bound address */
		struct {
			unsigned prog;	/* program number */
			unsigned lowvers;	/* lowest version supported */
			unsigned highvers;	/* highest version supported */
		} rpcnum;
	} se_un;
	int	se_count;		/* number started since se_time */
	struct	timeval se_time;	/* start of se_count */
	struct	servtab *se_next;
} *servtab;

#define se_ctrladdr se_un.ctrladdr
#define se_rpc se_un.rpcnum

int echo_stream(), discard_stream(), machtime_stream();
int daytime_stream(), chargen_stream();
int echo_dg(), discard_dg(), machtime_dg(), daytime_dg(), chargen_dg();

struct biltin {
	char	*bi_service;		/* internally provided service name */
	int	bi_socktype;		/* type of socket supported */
	short	bi_fork;		/* 1 if should fork before call */
	short	bi_wait;		/* 1 if should wait for child */
	int	(*bi_fn)();		/* function which performs it */
} biltins[] = {
	/* Echo received data */
	"echo",		SOCK_STREAM,	1, 0,	echo_stream,
	"echo",		SOCK_DGRAM,	0, 0,	echo_dg,

	/* Internet /dev/null */
	"discard",	SOCK_STREAM,	1, 0,	discard_stream,
	"discard",	SOCK_DGRAM,	0, 0,	discard_dg,

	/* Return 32 bit time since 1970 */
	"time",		SOCK_STREAM,	0, 0,	machtime_stream,
	"time",		SOCK_DGRAM,	0, 0,	machtime_dg,

	/* Return human-readable time */
	"daytime",	SOCK_STREAM,	0, 0,	daytime_stream,
	"daytime",	SOCK_DGRAM,	0, 0,	daytime_dg,

	/* Familiar character generator */
	"chargen",	SOCK_STREAM,	1, 0,	chargen_stream,
	"chargen",	SOCK_DGRAM,	0, 0,	chargen_dg,
	0
};

#define NUMINT	(sizeof(intab) / sizeof(struct inent))
char	*CONFIG = "/etc/inetd.conf";
char	**Argv;
char 	*LastArg;

main(argc, argv, envp)
	int argc;
	char *argv[], *envp[];
{
	register struct servtab *sep;
	register struct passwd *pwd;
	char *cp, buf[50];
	int pid, i, dofork;
	struct sigvec sv;
	struct rlimit rlimit;

	Argv = argv;
	if (envp == 0 || *envp == 0)
		envp = argv;
	while (*envp)
		envp++;
	LastArg = envp[-1] + strlen(envp[-1]);
	argc--, argv++;
	while (argc > 0 && *argv[0] == '-') {
		for (cp = &argv[0][1]; *cp; cp++) switch (*cp) {

		case 'd':
			debug = 1;
			options |= SO_DEBUG;
			break;

		default:
			fprintf(stderr,
			    "inetd: Unknown flag -%c ignored.\n", *cp);
			break;
		}
		argc--, argv++;
	}
	if (argc > 0)
		CONFIG = argv[0];

	if (getrlimit(RLIMIT_NOFILE, &rlimit) == 0)
	  {
	    rlimit.rlim_cur = rlimit.rlim_max;
	    setrlimit(RLIMIT_NOFILE, &rlimit);
	  }

	ndescriptors = getdtablesize();
	maxservers = ndescriptors - OTHERDESCRIPTORS;
#ifndef DEBUG
	if (fork())
		exit(0);
	{ int s;
	for (s = 0; s < ndescriptors; s++)
		(void) close(s);
	}
	(void) open("/", O_RDONLY);
	(void) dup2(0, 1);
	(void) dup2(0, 2);
	{ int tt = open("/dev/tty", O_RDWR);
	  if (tt > 0) {
		ioctl(tt, TIOCNOTTY, (char *)0);
		(void) close(tt);
	  }
	}
#else
	{ int s;
	for (s = 3; s < ndescriptors; s++)
		(void) close(s);
	}
#endif
	openlog("inetd", LOG_PID | LOG_NOWAIT, LOG_DAEMON);
	bzero((char *)&sv, sizeof(sv));
	sv.sv_mask = SIGBLOCK;
	sv.sv_handler = retry;
	sigvec(SIGALRM, &sv, (struct sigvec *)0);
	config();
	sv.sv_handler = config;
	sigvec(SIGHUP, &sv, (struct sigvec *)0);
	sv.sv_handler = reapchild;
	sigvec(SIGCHLD, &sv, (struct sigvec *)0);

	for (;;) {
	    int ctrl, n;
	    fd_set readable;
	    struct sockaddr_in his_addr;
	    int hisaddrlen = sizeof (his_addr);

	    while (nsock == 0)
		    sigpause(0);
	    readable = allsock;
	    if ((n = select(maxsock + 1, &readable, (fd_set *)0,
		(fd_set *)0, (struct timeval *)0)) <= 0) {
		    if (n < 0 && errno != EINTR)
				syslog(LOG_WARNING, "select: %m\n");
		    sleep(1);
		    continue;
	    }
	    for (sep = servtab; n && sep; sep = sep->se_next)
	    if (sep->se_fd != -1 && FD_ISSET(sep->se_fd, &readable)) {
		n--;
		if (debug)
			fprintf(stderr, "someone wants %s\n", sep->se_service);
		if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
			ctrl = accept(sep->se_fd, &his_addr, &hisaddrlen);
			if (debug)
				fprintf(stderr, "accept, ctrl %d\n", ctrl);
			if (ctrl < 0) {
				if (errno == EINTR)
					continue;
				syslog(LOG_WARNING, "accept: %m");
				continue;
			}
		} else
			ctrl = sep->se_fd;
		(void) sigblock(SIGBLOCK);
		pid = 0;
		dofork = (sep->se_bi == 0 || sep->se_bi->bi_fork);
		if (dofork) {
			if (sep->se_count++ == 0)
			    (void)gettimeofday(&sep->se_time,
			        (struct timezone *)0);
			else if (sep->se_count >= TOOMANY) {
				struct timeval now;

				(void)gettimeofday(&now, (struct timezone *)0);
				if (now.tv_sec - sep->se_time.tv_sec >
				    CNT_INTVL) {
					sep->se_time = now;
					sep->se_count = 1;
				} else {
					syslog(LOG_ERR,
			"%s/%s server failing (looping), service terminated",
					    sep->se_service, sep->se_proto);
					termserv(sep);
					sep->se_count = 0;
					sigsetmask(0);
					if (!timingout) {
						timingout = 1;
						alarm(RETRYTIME);
					}
					continue;
				}
			}
			pid = fork();
		}
		if (pid < 0) {
			if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
				(void) close(ctrl);
			sigsetmask(0);
			sleep(1);
			continue;
		}
		if (pid && sep->se_wait) {
			sep->se_wait = pid;
			FD_CLR(sep->se_fd, &allsock);
			nsock--;
		}
		sigsetmask(0);
		if (pid == 0) {
			char addrbuf[32];
#ifdef	DEBUG
			int tt;

			if (dofork && (tt = open("/dev/tty", O_RDWR)) > 0) {
				ioctl(tt, TIOCNOTTY, 0);
				(void) close(tt);
			}
#endif

			sprintf(addrbuf, "%x.%d", ntohl(his_addr.sin_addr.s_addr),
					ntohs(his_addr.sin_port));
			if (dofork)
				for (i = ndescriptors; --i > 2; )
					if (i != ctrl)
						(void) close(i);
			if (sep->se_bi)
				(*sep->se_bi->bi_fn)(ctrl, sep);
			else {
				setsid();
				(void) dup2(ctrl, 0);
				(void) close(ctrl);
				(void) dup2(0, 1);
				(void) dup2(0, 2);
				if ((pwd = getpwnam(sep->se_user)) == NULL) {
					syslog(LOG_ERR,
						"getpwnam: %s: No such user",
						sep->se_user);
					if (sep->se_socktype != SOCK_STREAM)
						recv(0, buf, sizeof (buf), 0);
					_exit(1);
				}
				if (pwd->pw_uid) {
					if (setgid((gid_t)pwd->pw_gid) == -1) {
						syslog(LOG_ERR,
						       "setgid(%d): %m", 
						       pwd->pw_gid);
						if (sep->se_socktype != 
						    SOCK_STREAM)
							recv(0, buf, 
							     sizeof (buf), 0);
						_exit(1);
					}
					initgroups(pwd->pw_name, pwd->pw_gid);
					if (setuid((uid_t)pwd->pw_uid) == -1) {
						syslog(LOG_ERR,
						       "setuid(%d): %m", 
						       pwd->pw_uid);
						if (sep->se_socktype != 
						    SOCK_STREAM)
							recv(0, buf, 
							     sizeof (buf), 0);
						_exit(1);
					}
				}
				if (debug)
					fprintf(stderr, "%d execl %s\n",
					    getpid(), sep->se_server);
				if (sep->se_argv[0] != NULL) {
				    if (!strcmp(sep->se_argv[0], "%A"))
					execl(sep->se_server,
						rindex(sep->se_server, '/')+1,
						sep->se_socktype == SOCK_DGRAM
						? (char *)0 : addrbuf, (char *)0);
				    else
					execv(sep->se_server, sep->se_argv);
			        } else
					execv(sep->se_server, sep->se_argv);
				if (sep->se_socktype != SOCK_STREAM)
					recv(0, buf, sizeof (buf), 0);
				syslog(LOG_ERR, "execv %s: %m", sep->se_server);
				_exit(1);
			}
		}
		if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
			(void) close(ctrl);
	    }
	}
}

void
reapchild()
{
	union wait status;
	int pid;
	register struct servtab *sep;
	extern char *sys_siglist[];

	for (;;) {
		pid = wait3(&status, WNOHANG, (struct rusage *)0);
		if (pid <= 0)
			break;
		if (debug)
			fprintf(stderr, "%d reaped\n", pid);
		for (sep = servtab; sep; sep = sep->se_next)
			if (sep->se_wait == pid) {
				if (status.w_status) {
					if (status.w_termsig) {
						if (status.w_termsig > NSIG)
							syslog(LOG_WARNING,
							    "%s: Signal %d%s",
							    sep->se_server,
							    status.w_termsig,
							    (status.w_coredump?
							    " - core dumped" :
							    ""));
						else
							syslog(LOG_WARNING,
							    "%s: %s%s",
							    sep->se_server,
							    sys_siglist[status.w_termsig],
							    (status.w_coredump?
							    " - core dumped" :
							    ""));
					} else {
						syslog(LOG_WARNING,
						    "%s: exit status %d",
						    sep->se_server,
						    status.w_retcode);
					}
				}
				if (debug)
					fprintf(stderr, "restored %s, fd %d\n",
					    sep->se_service, sep->se_fd);
				FD_SET(sep->se_fd, &allsock);
				nsock++;
				sep->se_wait = 1;
			}
	}
}

void
config()
{
	register struct servtab *sep, *cp, **sepp;
	struct servtab *getconfigent(), *enter();
	int omask;

	if (!setconfig()) {
		syslog(LOG_ERR, "%s: %m", CONFIG);
		return;
	}
	for (sep = servtab; sep; sep = sep->se_next)
		sep->se_checked = 0;
	while (cp = getconfigent()) {
		for (sep = servtab; sep; sep = sep->se_next) {
			if (sep->se_isrpc) {
				if (cp->se_isrpc
				    && sep->se_rpc.prog == cp->se_rpc.prog
				    && strcmp(sep->se_proto, cp->se_proto) == 0)
					break;
			} else {
				if (!cp->se_isrpc
				    && strcmp(sep->se_service, cp->se_service) == 0
				    && strcmp(sep->se_proto, cp->se_proto) == 0)
					break;
			}
		}
		if (sep != 0) {
			int i;

			omask = sigblock(SIGBLOCK);
			/*
			 * Don't touch se_wait if it's recording the
			 * pid for an outstanding daemon process.
			 */
			if (cp->se_bi == 0 && (sep->se_wait <= 1))
				sep->se_wait = cp->se_wait;
#define SWAP(a, b) { char *c = a; a = b; b = c; }
			if (cp->se_user)
				SWAP(sep->se_user, cp->se_user);
			if (cp->se_server)
				SWAP(sep->se_server, cp->se_server);
			for (i = 0; i < MAXARGV; i++)
				SWAP(sep->se_argv[i], cp->se_argv[i]);
			sigsetmask(omask);
			freeconfig(cp);
			if (debug)
				print_service("REDO", sep);
		} else {
			sep = enter(cp);
			if (debug)
				print_service("ADD ", sep);
		}
		sep->se_checked = 1;
		if (sep->se_isrpc) {
			if (sep->se_fd != -1)
				termserv(sep);
			else
				unregister(sep);	/* just in case */
			if (nservers >= maxservers) {
				syslog(LOG_ERR, "%s/%s: too many services (max %d)",
				    sep->se_service, sep->se_proto,
				    maxservers);
				sep->se_fd = -1;
				continue;
			}
			setuprpc(sep);
		} else {
			sp = getservbyname(sep->se_service, sep->se_proto);
			if (sp == NULL) {
				syslog(LOG_ERR, "%s/%s: unknown service",
				    sep->se_service, sep->se_proto);
				if (sep->se_fd != -1)
					termserv(sep);
				continue;
			}
			if (sp->s_port != sep->se_ctrladdr.sin_port) {
				sep->se_ctrladdr.sin_port = sp->s_port;
				if (sep->se_fd != -1)
					termserv(sep);
			}
			if (sep->se_fd == -1) {
				if (nservers >= maxservers) {
					syslog(LOG_ERR, "%s/%s: too many services (max %d)",
					    sep->se_service, sep->se_proto,
					    maxservers);
					sep->se_fd = -1;
					continue;
				}
				setup(sep);
			}
		}
	}
	endconfig();
	/*
	 * Purge anything not looked at above.
	 * XXX - if we add a service and delete one, the new service
	 * will be added to the count of services before the deleted one
	 * is subtracted.  This means you may run out of services if this
	 * happens; however, we can't do much about that, since we get
	 * the socket for the new one before we close the one for the
	 * deleted service, and if we allowed that extra service we might
	 * run out of descriptors.
	 */
	omask = sigblock(SIGBLOCK);
	sepp = &servtab;
	while (sep = *sepp) {
		if (sep->se_checked) {
			sepp = &sep->se_next;
			continue;
		}
		*sepp = sep->se_next;
		if (sep->se_fd != -1)
			termserv(sep);
		if (debug)
			print_service("FREE", sep);
		freeconfig(sep);
		free((char *)sep);
	}
	(void) sigsetmask(omask);
}

/*
 * Try again to establish sockets on which to listen for requests
 * for non-RPC-based services (if the attempt failed before, it was either
 * because a socket could not be created, or more likely because the socket
 * could not be bound to the service's address - probably because there was
 * already a daemon out there with a socket bound to that address).
 */
void
retry()
{
	register struct servtab *sep;

	timingout = 0;
	for (sep = servtab; sep; sep = sep->se_next) {
		if (sep->se_fd == -1 && !sep->se_isrpc) {
			if (nservers < maxservers)
				setup(sep);
		}
	}
}

/*
 * Set up to accept requests for a non-RPC-based service.  Create a socket
 * to listen for connections or datagrams, bind it to the address of that
 * service, add its socket descriptor to the list of descriptors to poll,
 * and increment the number of socket descriptors and active services.
 */
setup(sep)
	register struct servtab *sep;
{
	int on = 1;

	if ((sep->se_fd = socket(AF_INET, sep->se_socktype, 0)) < 0) {
		syslog(LOG_ERR, "%s/%s: socket: %m",
		    sep->se_service, sep->se_proto);
		return;
	}
#define	turnon(fd, opt) \
setsockopt(fd, SOL_SOCKET, opt, (char *)&on, sizeof (on))
	if (strcmp(sep->se_proto, "tcp") == 0 && (options & SO_DEBUG) &&
	    turnon(sep->se_fd, SO_DEBUG) < 0)
		syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m");
	if (turnon(sep->se_fd, SO_REUSEADDR) < 0)
		syslog(LOG_ERR, "setsockopt (SO_REUSEADDR): %m");
#undef turnon
	if (bind(sep->se_fd, &sep->se_ctrladdr,
	    sizeof (sep->se_ctrladdr)) < 0) {
		syslog(LOG_ERR, "%s/%s: bind: %m",
		    sep->se_service, sep->se_proto);
		(void) close(sep->se_fd);
		sep->se_fd = -1;
		if (!timingout) {
			timingout = 1;
			alarm(RETRYTIME);
		}
		return;
	}
	if (sep->se_socktype == SOCK_STREAM)
		listen(sep->se_fd, 10);
	FD_SET(sep->se_fd, &allsock);
	nsock++;
	if (sep->se_fd > maxsock)
		maxsock = sep->se_fd;
	nservers++;
}

/*
 * Set up to accept requests for an RPC-based service.  Create a socket
 * to listen for connections or datagrams, bind it to a system-chosen
 * address, register it with the portmapper under that address, add its
 * socket descriptor to the list of descriptors to poll, and increment
 * the number of socket descriptors and active services.
 */
setuprpc(sep)
	register struct servtab *sep;
{
	register int i;
	struct sockaddr_in addr;
	int len = sizeof(struct sockaddr_in);
	
	if ((sep->se_fd = socket(AF_INET, sep->se_socktype, 0)) < 0) {
		syslog(LOG_ERR, "%s/%s: socket: %m",
		    sep->se_service, sep->se_proto);
		return;
	}
	addr.sin_family = AF_INET;
	addr.sin_port = 0;
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	if (bind(sep->se_fd, &addr, sizeof(addr)) < 0) {
		syslog(LOG_ERR, "%s/%s: bind: %m",
		    sep->se_service, sep->se_proto);
		(void) close(sep->se_fd);
		sep->se_fd = -1;
		return;
	}
	if (getsockname(sep->se_fd, &addr, &len) != 0) {
		syslog(LOG_ERR, "%s/%s: getsockname: %m",
		    sep->se_service, sep->se_proto);
		(void) close(sep->se_fd);
		sep->se_fd = -1;
		return;
	}
	for (i = sep->se_rpc.lowvers; i <= sep->se_rpc.highvers; i++) {
                pmap_set(sep->se_rpc.prog, i, (sep->se_socktype == SOCK_DGRAM) ?
		    IPPROTO_UDP : IPPROTO_TCP, ntohs(addr.sin_port));
	}
	if (sep->se_socktype == SOCK_STREAM)
		listen(sep->se_fd, 10);
	FD_SET(sep->se_fd, &allsock);
	nsock++;
	if (sep->se_fd > maxsock)
		maxsock = sep->se_fd;
	nservers++;
}

/*
 * Shut down a service.  Unregister it if it's an RPC service, remove
 * its socket descriptor from the list of descriptors to poll, close
 * that socket descriptor, set it to -1 (to indicate that it's shut down),
 * and decrement the number of socket descriptors and active services.
 */
void
termserv(sep)
	register struct servtab *sep;
{
	if (sep->se_isrpc) {
		/*
		 * Have to do this here because there might be multiple
		 * registers of the same prognum.
		 */
		unregister(sep);
	}
	FD_CLR(sep->se_fd, &allsock);
	nsock--;
	(void) close(sep->se_fd);
	sep->se_fd = -1;
	nservers--;
}

/*
 * Unregister an RPC service.
 */
void
unregister(sep)
	register struct servtab *sep;
{
	register int i;
	register struct servtab *s;
	unsigned prog;

	/*
	 * Unregister the service only if there were no rpc programnum
	 * earlier, because then you would pmap_unset that too!
	 * Added to support multiple transports for the same prognum.
	 */
	prog = sep->se_rpc.prog;
	for (s = servtab; s; s = s->se_next) {
		if (s == sep)	/* Ignore this one */
			continue;
		if ((s->se_checked == 0) || !s->se_isrpc ||
			(prog != s->se_rpc.prog))
			continue;
		/* Found an existing entry for that prog number */
		return;
	}
	for (i = sep->se_rpc.lowvers; i <= sep->se_rpc.highvers; i++)
		pmap_unset(sep->se_rpc.prog, i);
}

struct servtab *
enter(cp)
	struct servtab *cp;
{
	register struct servtab *sep;
	int omask;
	char *strdup();

	sep = (struct servtab *)malloc(sizeof (*sep));
	if (sep == (struct servtab *)0) {
		syslog(LOG_ERR, "Out of memory.");
		exit(-1);
	}
	*sep = *cp;
	sep->se_fd = -1;
	omask = sigblock(SIGBLOCK);
	sep->se_next = servtab;
	servtab = sep;
	sigsetmask(omask);
	return (sep);
}

FILE	*fconfig = NULL;
struct	servtab serv;
char	line[256];
char	*skip(), *nextline();

setconfig()
{

	if (fconfig != NULL) {
		fseek(fconfig, 0L, L_SET);
		return (1);
	}
	fconfig = fopen(CONFIG, "r");
	return (fconfig != NULL);
}

endconfig()
{

	if (fconfig == NULL)
		return;
	fclose(fconfig);
	fconfig = NULL;
}

#define LINEBUF 80

struct servtab *
getconfigent()
{
	register struct servtab *sep = &serv;
	char *cp, *arg, *tp, *strp;
	int argc;
	struct rpcent *rpc;

more:
	bzero((char *) sep, sizeof(struct servtab));
	/* skip over comment lines and blank lines */
	while ((cp = nextline(fconfig)) && (*cp == '#' || *cp == '\0'))
		;
	if (cp == NULL)
		return ((struct servtab *)0);
	sep->se_service = strdup(skip(&cp));
	arg = skip(&cp);
	if (strcmp(arg, "stream") == 0)
		sep->se_socktype = SOCK_STREAM;
	else if (strcmp(arg, "dgram") == 0)
		sep->se_socktype = SOCK_DGRAM;
	else if (strcmp(arg, "rdm") == 0)
		sep->se_socktype = SOCK_RDM;
	else if (strcmp(arg, "seqpacket") == 0)
		sep->se_socktype = SOCK_SEQPACKET;
	else if (strcmp(arg, "raw") == 0)
		sep->se_socktype = SOCK_RAW;
	else
		sep->se_socktype = -1;
	sep->se_proto = strdup(skip(&cp));
	if (strncmp(sep->se_proto, "rpc/", 4) == 0) {
		sep->se_isrpc = 1;
		sep->se_rpc.lowvers = 0;
		sep->se_rpc.highvers = 0;
		tp = sep->se_service;
		while (*tp != '/') {
			if (*tp == '\0') {
				sep->se_rpc.lowvers = 1;
				sep->se_rpc.highvers = 1;
				break;
			} else
				tp++;
		}
		*tp = '\0';
		if ((rpc = getrpcbyname(sep->se_service)) != NULL)
			sep->se_rpc.prog = rpc->r_number;
		else {
			strp = sep->se_service;
			sep->se_rpc.prog = strtol(strp, &strp, 10);
			if (strp != tp) {
				/*
				 * Service name isn't all-numeric, so
				 * since we didn't find it it must not
				 * be known.
				 */
				syslog(LOG_ERR, "%s/%s: unknown service",
				    sep->se_service, sep->se_proto);
				freeconfig(sep);
				goto more;
			}
		}
		if (sep->se_rpc.lowvers == 0) {
			/*
			 * The service name ended with a slash, so the
			 * version number(s) are explicitly specified.
			 */
			tp++;
			strp = tp;
			sep->se_rpc.lowvers = strtol(tp, &strp, 10);
			tp = strp;
			if (*tp == '-') {
				tp++;
				strp = tp;
				sep->se_rpc.highvers = strtol(tp, &strp, 10);
				if (*strp != '\0') {
					syslog(LOG_ERR, "%s/%s: bad high version number",
					    sep->se_service, sep->se_proto);
					freeconfig(sep);
					goto more;
				}
			} else if (*tp == '\0')
				sep->se_rpc.highvers = sep->se_rpc.lowvers;
			else {
				syslog(LOG_ERR, "%s/%s: bad version number",
				    sep->se_service, sep->se_proto);
				freeconfig(sep);
				goto more;
			}
		}
	} else
		sep->se_isrpc = 0;

	arg = skip(&cp);
	sep->se_wait = strcmp(arg, "wait") == 0;
	sep->se_user = strdup(skip(&cp));
	sep->se_server = strdup(skip(&cp));
	if (strcmp(sep->se_server, "internal") == 0) {
		register struct biltin *bi;

		for (bi = biltins; bi->bi_service; bi++)
			if (bi->bi_socktype == sep->se_socktype &&
			    strcmp(bi->bi_service, sep->se_service) == 0)
				break;
		if (bi->bi_service == 0) {
			syslog(LOG_ERR, "internal service %s/%s unknown",
			    sep->se_service, sep->se_proto);
			freeconfig(sep);
			goto more;
		}
		sep->se_bi = bi;
		sep->se_wait = bi->bi_wait;
	} else
		sep->se_bi = NULL;
	argc = 0;
	for (arg = skip(&cp); cp; arg = skip(&cp))
		if (argc < MAXARGV)
			sep->se_argv[argc++] = strdup(arg);
	while (argc <= MAXARGV)
		sep->se_argv[argc++] = NULL;
	return (sep);
}

freeconfig(cp)
	register struct servtab *cp;
{
	int i;

	if (cp->se_service)
		free(cp->se_service);
	if (cp->se_proto)
		free(cp->se_proto);
	if (cp->se_user)
		free(cp->se_user);
	if (cp->se_server)
		free(cp->se_server);
	for (i = 0; i < MAXARGV; i++)
		if (cp->se_argv[i])
			free(cp->se_argv[i]);
}


char *
skip(cpp)
	char **cpp;
{
	register char *cp = *cpp;
	char *start;
	static char nullstring[1] = "";
	
	if (cp == (char *) 0)
		return(nullstring);
again:
	while (*cp == ' ' || *cp == '\t')
		cp++;
	if (*cp == '\0') {
		int i;
		if ((i = getc(fconfig)) != EOF) {
			char c = (char) i;
			ungetc(c, fconfig);
			/*
			 * A config line can be continued on subsequent
			 * indented lines.
			 */
			if (c == ' ' || c == '\t')
				if (cp = nextline(fconfig))
					goto again;
		}
		/*
		 * Signal end of line or file.  We can't just return the
		 * null pointer, though.  If the end occured in the middle
		 * of parsing a config line we have to continue returning valid
		 * string pointers for the benefit of code that might
		 * do strdup()'s or strcmp()'s against them.
		 */
		*cpp = 0;
		return(nullstring);
	}
	start = cp;
	while (*cp && *cp != ' ' && *cp != '\t')
		cp++;
	if (*cp != '\0')
		*cp++ = '\0';
	*cpp = cp;
	return (start);
}

char *
nextline(fd)
	FILE *fd;
{
	char *cp;

	if (fgets(line, sizeof (line), fd) == NULL)
		return ((char *)0);
	cp = index(line, '\n');
	if (cp)
		*cp = '\0';
	return (line);
}

char *
strdup(cp)
	char *cp;
{
	char *new;

	if (cp == NULL)
		cp = "";
	new = malloc((unsigned)(strlen(cp) + 1));
	if (new == (char *)0) {
		syslog(LOG_ERR, "Out of memory.");
		exit(-1);
	}
	strcpy(new, cp);
	return (new);
}

setproctitle(a, s)
	char *a;
	int s;
{
	int size;
	register char *cp;
	struct sockaddr_in sin;
	char buf[80];

	cp = Argv[0];
	size = sizeof(sin);
	if (getpeername(s, &sin, &size) == 0)
		sprintf(buf, "-%s [%s]", a, inet_ntoa(sin.sin_addr)); 
	else
		sprintf(buf, "-%s", a); 
	strncpy(cp, buf, LastArg - cp);
	cp += strlen(cp);
	while (cp < LastArg)
		*cp++ = ' ';
}

/*
 * Internet services provided internally by inetd:
 */

/* ARGSUSED */
echo_stream(s, sep)		/* Echo service -- echo data back */
	int s;
	struct servtab *sep;
{
	char buffer[BUFSIZ];
	int i;

	setproctitle("echo", s);
	while ((i = read(s, buffer, sizeof(buffer))) > 0 &&
	    write(s, buffer, i) > 0)
		;
	exit(0);
}

/* ARGSUSED */
echo_dg(s, sep)			/* Echo service -- echo data back */
	int s;
	struct servtab *sep;
{
	char buffer[BUFSIZ];
	int i, size;
	struct sockaddr sa;

	size = sizeof(sa);
	if ((i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size)) < 0)
		return;
	(void) sendto(s, buffer, i, 0, &sa, sizeof(sa));
}

/* ARGSUSED */
discard_stream(s, sep)		/* Discard service -- ignore data */
	int s;
	struct servtab *sep;
{
	char buffer[BUFSIZ];

	setproctitle("discard", s);
	while (1) {
		while (read(s, buffer, sizeof(buffer)) > 0)
			;
		if (errno != EINTR)
			break;
	}
	exit(0);
}

/* ARGSUSED */
discard_dg(s, sep)		/* Discard service -- ignore data */
	int s;
	struct servtab *sep;
{
	char buffer[BUFSIZ];

	(void) read(s, buffer, sizeof(buffer));
}

#include <ctype.h>
#define LINESIZ 72
char ring[128];
char *endring;

initring()
{
	register int i;

	endring = ring;

	for (i = 0; i <= 128; ++i)
		if (isprint(i))
			*endring++ = i;
}

/* ARGSUSED */
chargen_stream(s, sep)		/* Character generator */
	int s;
	struct servtab *sep;
{
	char text[LINESIZ+2];
	register int i;
	register char *rp, *rs, *dp;

	setproctitle("discard", s);
	if (endring == 0)
		initring();

	for (rs = ring; ; ++rs) {
		if (rs >= endring)
			rs = ring;
		rp = rs;
		dp = text;
		i = MIN(LINESIZ, endring - rp);
		bcopy(rp, dp, i);
		dp += i;
		if ((rp += i) >= endring)
			rp = ring;
		if (i < LINESIZ) {
			i = LINESIZ - i;
			bcopy(rp, dp, i);
			dp += i;
			if ((rp += i) >= endring)
				rp = ring;
		}
		*dp++ = '\r';
		*dp++ = '\n';

		if (write(s, text, dp - text) != dp - text)
			break;
	}
	exit(0);
}

/* ARGSUSED */
chargen_dg(s, sep)		/* Character generator */
	int s;
	struct servtab *sep;
{
	char text[LINESIZ+2];
	register int i;
	register char *rp;
	static char *rs = ring;
	struct sockaddr sa;
	int size;

	if (endring == 0)
		initring();

	size = sizeof(sa);
	if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0)
		return;
	rp = rs;
	if (rs++ >= endring)
		rs = ring;
	i = MIN(LINESIZ - 2, endring - rp);
	bcopy(rp, text, i);
	if ((rp += i) >= endring)
		rp = ring;
	if (i < LINESIZ - 2) {
		bcopy(rp, text, i);
		if ((rp += i) >= endring)
			rp = ring;
	}
	text[LINESIZ - 2] = '\r';
	text[LINESIZ - 1] = '\n';

	(void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa));
}

/*
 * Return a machine readable date and time, in the form of the
 * number of seconds since midnight, Jan 1, 1900.  Since gettimeofday
 * returns the number of seconds since midnight, Jan 1, 1970,
 * we must add 2208988800 seconds to this figure to make up for
 * some seventy years Bell Labs was asleep.
 */

long
machtime()
{
	struct timeval tv;

	if (gettimeofday(&tv, (struct timezone *)0) < 0) {
		fprintf(stderr, "Unable to get time of day\n");
		return (0L);
	}
	return (htonl((long)tv.tv_sec + 2208988800));
}

/* ARGSUSED */
machtime_stream(s, sep)
	int s;
	struct servtab *sep;
{
	long result;

	result = machtime();
	(void) write(s, (char *) &result, sizeof(result));
}

/* ARGSUSED */
machtime_dg(s, sep)
	int s;
	struct servtab *sep;
{
	long result;
	struct sockaddr sa;
	int size;

	size = sizeof(sa);
	if (recvfrom(s, (char *)&result, sizeof(result), 0, &sa, &size) < 0)
		return;
	result = machtime();
	(void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa));
}

/* ARGSUSED */
daytime_stream(s, sep)		/* Return human-readable time of day */
	int s;
	struct servtab *sep;
{
	char buffer[256];
	time_t time(), clock;
	char *ctime();

	clock = time((time_t *) 0);

	sprintf(buffer, "%s\r", ctime(&clock));
	(void) write(s, buffer, strlen(buffer));
}

/* ARGSUSED */
daytime_dg(s, sep)		/* Return human-readable time of day */
	int s;
	struct servtab *sep;
{
	char buffer[256];
	time_t time(), clock;
	struct sockaddr sa;
	int size;
	char *ctime();

	clock = time((time_t *) 0);

	size = sizeof(sa);
	if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0)
		return;
	sprintf(buffer, "%s\r", ctime(&clock));
	(void) sendto(s, buffer, strlen(buffer), 0, &sa, sizeof(sa));
}

/*
 * print_service:
 *	Dump relevant information to stderr
 */
print_service(action, sep)
	char *action;
	struct servtab *sep;
{
	fprintf(stderr,
	    "%s: %s proto=%s, wait=%d, user=%s builtin=%x server=%s\n",
	    action, sep->se_service, sep->se_proto,
	    sep->se_wait, sep->se_user, sep->se_bi, sep->se_server);
}

#define NO_SETSID
#ifdef NO_SETSID
#include <sys/syscall.h>

/*
 * BSD setpgrp(0,0) turns into a setsid() anyway and this will
 * also behave nicely in 4.0 kernels.
 */
setsid() 
{
	return syscall(SYS_setpgrp, 0, 0); 
}
#endif
