Index: head/usr.sbin/inetd/inetd.8 =================================================================== --- head/usr.sbin/inetd/inetd.8 (revision 2658) +++ head/usr.sbin/inetd/inetd.8 (revision 2659) @@ -1,413 +1,425 @@ .\" Copyright (c) 1985, 1991, 1993, 1994 .\" The Regents of the University of California. 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. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. .\" .\" from: @(#)inetd.8 8.3 (Berkeley) 4/13/94 .\" $Id$ .\" .Dd April 13, 1994 .Dt INETD 8 .Os BSD 4.4 .Sh NAME .Nm inetd .Nd internet .Dq super-server .Sh SYNOPSIS .Nm inetd .Op Fl d +.Op Fl l .Op Fl R Ar rate .Op Ar configuration file .Sh DESCRIPTION The .Nm inetd program should be run at boot time by .Pa /etc/rc (see .Xr rc 8 ) . It then listens for connections on certain internet sockets. When a connection is found on one of its sockets, it decides what service the socket corresponds to, and invokes a program to service the request. The server program is invoked with the service socket as its standard input, output and error descriptors. After the program is finished, .Nm inetd continues to listen on the socket (except in some cases which will be described below). Essentially, .Nm inetd allows running one daemon to invoke several others, reducing load on the system. .Pp The options available for .Nm inetd: .Bl -tag -width Ds .It Fl d Turns on debugging. +.It Fl l +Turns on logging. .It Fl R Ar rate Specifies the maximum number of times a service can be invoked in one minute; the default is 1000. .El .Pp Upon execution, .Nm inetd reads its configuration information from a configuration file which, by default, is .Pa /etc/inetd.conf . There must be an entry for each field of the configuration file, with entries for each field separated by a tab or a space. Comments are denoted by a ``#'' at the beginning of a line. There must be an entry for each field. The fields of the configuration file are as follows: .Pp .Bd -unfilled -offset indent -compact service name socket type protocol wait/nowait user server program server program arguments .Ed .Pp To specify a .Em Sun-RPC based service, the entry would contain these fields: .Pp .Bd -unfilled -offset indent -compact service name/version socket type rpc/protocol user server program server program arguments .Ed .Pp There are two types of services that .Nm inetd can start: standard and TCPMUX. A standard service has a well-known port assigned to it; it may be a service that implements an official Internet standard or is a BSD-specific service. As described in .Tn RFC 1078 , TCPMUX services are nonstandard services that do not have a well-known port assigned to them. They are invoked from .Nm inetd when a program connects to the .Dq tcpmux well-known port and specifies the service name. This feature is useful for adding locally-developed servers. .Pp The .Em service-name entry is the name of a valid service in the file .Pa /etc/services . For .Dq internal services (discussed below), the service name .Em must be the official name of the service (that is, the first entry in .Pa /etc/services ) . When used to specify a .Em Sun-RPC based service, this field is a valid RPC service name in the file .Pa /etc/rpc . The part on the right of the .Dq / is the RPC version number. This can simply be a single numeric argument or a range of versions. A range is bounded by the low version to the high version - .Dq rusers/1-3 . For TCPMUX services, the value of the .Em service-name field consists of the string .Dq tcpmux followed by a slash and the locally-chosen service name. The service names listed in .Pa /etc/services and the name .Dq help are reserved. Try to choose unique names for your TCPMUX services by prefixing them with your organization's name and suffixing them with a version number. .Pp The .Em socket-type should be one of .Dq stream , .Dq dgram , .Dq raw , .Dq rdm , or .Dq seqpacket , depending on whether the socket is a stream, datagram, raw, reliably delivered message, or sequenced packet socket. TCPMUX services must use .Dq stream . .Pp The .Em protocol must be a valid protocol as given in .Pa /etc/protocols . Examples might be .Dq tcp or .Dq udp . Rpc based services are specified with the .Dq rpc/tcp or .Dq rpc/udp service type. TCPMUX services must use .Dq tcp . .Pp The .Em wait/nowait entry specifies whether the server that is invoked by inetd will take over the socket associated with the service access point, and thus whether .Nm inetd should wait for the server to exit before listening for new service requests. Datagram servers must use .Dq wait , as they are always invoked with the original datagram socket bound to the specified service address. These servers must read at least one datagram from the socket before exiting. If a datagram server connects to its peer, freeing the socket so .Nm inetd can received further messages on the socket, it is said to be a .Dq multi-threaded server; it should read one datagram from the socket and create a new socket connected to the peer. It should fork, and the parent should then exit to allow .Nm inetd to check for new service requests to spawn new servers. Datagram servers which process all incoming datagrams on a socket and eventually time out are said to be .Dq single-threaded . .Xr Comsat 8 , .Pq Xr biff 1 and .Xr talkd 8 are both examples of the latter type of datagram server. .Xr Tftpd 8 is an example of a multi-threaded datagram server. .Pp Servers using stream sockets generally are multi-threaded and use the .Dq nowait entry. Connection requests for these services are accepted by .Nm inetd , and the server is given only the newly-accepted socket connected to a client of the service. Most stream-based services operate in this manner. Stream-based servers that use .Dq wait are started with the listening service socket, and must accept at least one connection request before exiting. Such a server would normally accept and process incoming connection requests until a timeout. TCPMUX services must use .Dq nowait . .Pp The .Em user entry should contain the user name of the user as whom the server should run. This allows for servers to be given less permission than root. .Pp The .Em server-program entry should contain the pathname of the program which is to be executed by .Nm inetd when a request is found on its socket. If .Nm inetd provides this service internally, this entry should be .Dq internal . .Pp The .Em server program arguments should be just as arguments normally are, starting with argv[0], which is the name of the program. If the service is provided internally, the word .Dq internal should take the place of this entry. .Pp The .Nm inetd program provides several .Dq trivial services internally by use of routines within itself. These services are .Dq echo , .Dq discard , .Dq chargen (character generator), .Dq daytime (human readable time), and .Dq time (machine readable time, in the form of the number of seconds since midnight, January 1, 1900). All of these services are tcp based. For details of these services, consult the appropriate .Tn RFC from the Network Information Center. +.Pp +When given the +.Fl l +option +.Nm Inetd +will log an entry to syslog each time an +.Xr accept 2 +is made, which notes the +service selected and the IP-number of the remote requestor. .Pp The .Nm inetd program rereads its configuration file when it receives a hangup signal, .Dv SIGHUP . Services may be added, deleted or modified when the configuration file is reread. .Sh TCPMUX .Pp .Tn RFC 1078 describes the TCPMUX protocol: ``A TCP client connects to a foreign host on TCP port 1. It sends the service name followed by a carriage-return line-feed . The service name is never case sensitive. The server replies with a single character indicating positive (+) or negative (\-) acknowledgment, immediately followed by an optional message of explanation, terminated with a . If the reply was positive, the selected protocol begins; otherwise the connection is closed.'' The program is passed the TCP connection as file descriptors 0 and 1. .Pp If the TCPMUX service name begins with a ``+'', .Nm inetd returns the positive reply for the program. This allows you to invoke programs that use stdin/stdout without putting any special server code in them. .Pp The special service name .Dq help causes .Nm inetd to list TCPMUX services in .Pa inetd.conf . .Sh "EXAMPLES" .Pp Here are several example service entries for the various types of services: .Bd -literal ftp stream tcp nowait root /usr/libexec/ftpd ftpd -l ntalk dgram udp wait root /usr/libexec/ntalkd ntalkd tcpmux/+date stream tcp nowait guest /bin/date date tcpmux/phonebook stream tcp nowait guest /usr/local/bin/phonebook phonebook rstatd/1-3 dgram rpc/udp wait root /usr/libexec/rpc.rstatd rpc.rstatd .Ed .Sh "ERROR MESSAGES" The .Nm inetd server logs error messages using .Xr syslog 3 . Important error messages and their explanations are: .Bd -literal \fIservice\fP/\fIprotocol\fP server failing (looping), service terminated. .Ed The number of requests for the specified service in the past minute exceeded the limit. The limit exists to prevent a broken program or a malicious user from swamping the system. This message may occur for several reasons: 1) there are lots of hosts requesting the service within a short time period, 2) a 'broken' client program is requesting the service too frequently, 3) a malicious user is running a program to invoke the service in a 'denial of service' attack, or 4) the invoked service program has an error that causes clients to retry quickly. Use the .Op Fl R option, as described above, to change the rate limit. Once the limit is reached, the service will be reenabled automatically in 10 minutes. .sp .Bd -literal \fIservice\fP/\fIprotocol\fP: No such user '\fIuser\fP', service ignored \fIservice\fP/\fIprotocol\fP: getpwnam: \fIuser\fP: No such user .Ed No entry for .Em user exists in the .Pa passwd file. The first message occurs when .Nm inetd (re)reads the configuration file. The second message occurs when the service is invoked. .sp .Bd -literal \fIservice\fP: can't set uid \fInumber\fP \fIservice\fP: can't set gid \fInumber\fP .Ed The user or group ID for the entry's .Em user is invalid. .Sh SEE ALSO .Xr comsat 8 , .Xr fingerd 8 , .Xr ftpd 8 , .Xr rexecd 8 , .Xr rlogind 8 , .Xr rshd 8 , .Xr telnetd 8 , .Xr tftpd 8 , .Xr portmap 8 , .Xr rpc 5 .Sh HISTORY The .Nm command appeared in .Bx 4.3 . TCPMUX is based on code and documentation by Mark Lottor. Support for .Em Sun-RPC based services is modelled after that provided by .Em SunOS 4.1 . Index: head/usr.sbin/inetd/inetd.c =================================================================== --- head/usr.sbin/inetd/inetd.c (revision 2658) +++ head/usr.sbin/inetd/inetd.c (revision 2659) @@ -1,1386 +1,1405 @@ /* * Copyright (c) 1983, 1991, 1993, 1994 * The Regents of the University of California. 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. */ #ifndef lint static char copyright[] = "@(#) Copyright (c) 1983, 1991, 1993, 1994\n\ The Regents of the University of California. All rights reserved.\n"; #endif /* not lint */ #ifndef lint /* from: @(#)inetd.c 8.4 (Berkeley) 4/13/94"; */ static char RCSid[] = "$Id"; #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 or must * name a tcpmux service * 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 (20) * * TCP services without official port numbers are handled with the * RFC1078-based tcpmux internal service. Tcpmux listens on port 1 for * requests. When a connection is made from a foreign host, the service * requested is passed to tcpmux, which looks it up in the servtab list * and returns the proper entry for the service. Tcpmux returns a * negative reply if the service doesn't exist, otherwise the invoked * server is expected to return the positive reply if the service type in * inetd.conf file has the prefix "tcpmux/". If the service type has the * prefix "tcpmux/+", tcpmux will return the positive reply for the * process; this is for compatibility with older server code, and also * allows you to invoke programs that use stdin/stdout without putting any * special server code in them. Services that use tcpmux are "nowait" * because they do not have a well-known port and hence cannot listen * for new requests. * * For RPC services * service name/version must be in /etc/rpc * 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 * * Comment lines are indicated by a `#' in column 1. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pathnames.h" -#define TOOMANY 40 /* don't start more than TOOMANY */ +#define TOOMANY 256 /* 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)) int debug = 0; +int log = 0; int nsock, maxsock; fd_set allsock; int options; int timingout; int toomany = TOOMANY; struct servent *sp; struct rpcent *rpc; struct servtab { char *se_service; /* name of service */ int se_socktype; /* type of socket to use */ char *se_proto; /* protocol used */ short se_wait; /* single threaded server */ short se_checked; /* looked at during merge */ char *se_user; /* user name to run as */ struct biltin *se_bi; /* if built-in, description */ char *se_server; /* server program */ #define MAXARGV 20 char *se_argv[MAXARGV+1]; /* program arguments */ int se_fd; /* open descriptor */ int se_type; /* type */ struct sockaddr_in se_ctrladdr;/* bound address */ int se_rpc; /* ==1 if RPC service */ int se_rpc_prog; /* RPC program number */ u_int se_rpc_lowvers; /* RPC low version */ u_int se_rpc_highvers; /* RPC high version */ int se_count; /* number started since se_time */ struct timeval se_time; /* start of se_count */ struct servtab *se_next; } *servtab; #define NORM_TYPE 0 #define MUX_TYPE 1 #define MUXPLUS_TYPE 2 #define ISMUX(sep) (((sep)->se_type == MUX_TYPE) || \ ((sep)->se_type == MUXPLUS_TYPE)) #define ISMUXPLUS(sep) ((sep)->se_type == MUXPLUS_TYPE) void chargen_dg __P((int, struct servtab *)); void chargen_stream __P((int, struct servtab *)); void close_sep __P((struct servtab *)); void config __P((int)); void daytime_dg __P((int, struct servtab *)); void daytime_stream __P((int, struct servtab *)); void discard_dg __P((int, struct servtab *)); void discard_stream __P((int, struct servtab *)); void echo_dg __P((int, struct servtab *)); void echo_stream __P((int, struct servtab *)); void endconfig __P((void)); struct servtab *enter __P((struct servtab *)); void freeconfig __P((struct servtab *)); struct servtab *getconfigent __P((void)); void machtime_dg __P((int, struct servtab *)); void machtime_stream __P((int, struct servtab *)); char *newstr __P((char *)); char *nextline __P((FILE *)); void print_service __P((char *, struct servtab *)); void reapchild __P((int)); void retry __P((int)); int setconfig __P((void)); void setup __P((struct servtab *)); char *sskip __P((char **)); char *skip __P((char **)); struct servtab *tcpmux __P((int)); void unregisterrpc __P((register struct servtab *sep)); 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 */ void (*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 }, { "tcpmux", SOCK_STREAM, 1, 0, (void (*)())tcpmux }, { NULL } }; #define NUMINT (sizeof(intab) / sizeof(struct inent)) char *CONFIG = _PATH_INETDCONF; char **Argv; char *LastArg; int main(argc, argv, envp) int argc; char *argv[], *envp[]; { struct servtab *sep; struct passwd *pwd; struct sigvec sv; int tmpint, ch, dofork; pid_t pid; char buf[50]; + struct sockaddr_in peer; + int i; Argv = argv; if (envp == 0 || *envp == 0) envp = argv; while (*envp) envp++; LastArg = envp[-1] + strlen(envp[-1]); openlog("inetd", LOG_PID | LOG_NOWAIT, LOG_DAEMON); - while ((ch = getopt(argc, argv, "dR:")) != EOF) + while ((ch = getopt(argc, argv, "dlR:")) != EOF) switch(ch) { case 'd': debug = 1; options |= SO_DEBUG; break; + case 'l': + log = 1; + break; case 'R': { /* invocation rate */ char *p; tmpint = strtol(optarg, &p, 0); if (tmpint < 1 || *p) syslog(LOG_ERR, "-R %s: bad value for service invocation rate", optarg); else toomany = tmpint; break; } case '?': default: syslog(LOG_ERR, - "usage: inetd [-d] [-R rate] [conf-file]"); + "usage: inetd [-dl] [-R rate] [conf-file]"); exit(1); } argc -= optind; argv += optind; if (argc > 0) CONFIG = argv[0]; if (debug == 0) { daemon(0, 0); } memset(&sv, 0, sizeof(sv)); sv.sv_mask = SIGBLOCK; sv.sv_handler = retry; sigvec(SIGALRM, &sv, (struct sigvec *)0); config(SIGHUP); sv.sv_handler = config; sigvec(SIGHUP, &sv, (struct sigvec *)0); sv.sv_handler = reapchild; sigvec(SIGCHLD, &sv, (struct sigvec *)0); { /* space for daemons to overwrite environment for ps */ #define DUMMYSIZE 100 char dummy[DUMMYSIZE]; (void)memset(dummy, 'x', sizeof(DUMMYSIZE) - 1); dummy[DUMMYSIZE - 1] = '\0'; (void)setenv("inetd_dummy", dummy, 1); } for (;;) { int n, ctrl; fd_set readable; if (nsock == 0) { (void) sigblock(SIGBLOCK); while (nsock == 0) sigpause(0L); (void) sigsetmask(0L); } 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"); 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, (struct sockaddr *)0, (int *)0); if (debug) fprintf(stderr, "accept, ctrl %d\n", ctrl); if (ctrl < 0) { if (errno != EINTR) syslog(LOG_WARNING, "accept (for %s): %m", sep->se_service); continue; + } + if(log) { + i = sizeof peer; + if(getpeername(ctrl, (struct sockaddr *) + &peer, &i)) { + syslog(LOG_WARNING, + "getpeername(for %s): %m", + sep->se_service); + continue; + } + syslog(LOG_INFO,"%s from %s", + sep->se_service, + inet_ntoa(peer.sin_addr)); } /* * Call tcpmux to find the real service to exec. */ if (sep->se_bi && sep->se_bi->bi_fn == (void (*)()) tcpmux) { sep = tcpmux(ctrl); if (sep == NULL) { close(ctrl); 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); close_sep(sep); sigsetmask(0L); if (!timingout) { timingout = 1; alarm(RETRYTIME); } continue; } } pid = fork(); } if (pid < 0) { syslog(LOG_ERR, "fork: %m"); if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) close(ctrl); sigsetmask(0L); sleep(1); continue; } if (pid && sep->se_wait) { sep->se_wait = pid; if (sep->se_fd >= 0) { FD_CLR(sep->se_fd, &allsock); nsock--; } } sigsetmask(0L); if (pid == 0) { if (debug && dofork) setsid(); if (dofork) { if (debug) fprintf(stderr, "+ Closing from %d\n", maxsock); for (tmpint = maxsock; tmpint > 2; tmpint--) if (tmpint != ctrl) close(tmpint); } if (sep->se_bi) (*sep->se_bi->bi_fn)(ctrl, sep); else { if (debug) fprintf(stderr, "%d execl %s\n", getpid(), sep->se_server); dup2(ctrl, 0); close(ctrl); dup2(0, 1); dup2(0, 2); if ((pwd = getpwnam(sep->se_user)) == NULL) { syslog(LOG_ERR, "%s/%s: %s: No such user", sep->se_service, sep->se_proto, sep->se_user); if (sep->se_socktype != SOCK_STREAM) recv(0, buf, sizeof (buf), 0); _exit(1); } if (pwd->pw_uid) { if (setgid(pwd->pw_gid) < 0) { syslog(LOG_ERR, "%s: can't set gid %d: %m", sep->se_service, pwd->pw_gid); _exit(1); } (void) initgroups(pwd->pw_name, pwd->pw_gid); if (setuid(pwd->pw_uid) < 0) { syslog(LOG_ERR, "%s: can't set uid %d: %m", sep->se_service, pwd->pw_uid); _exit(1); } } execv(sep->se_server, sep->se_argv); if (sep->se_socktype != SOCK_STREAM) recv(0, buf, sizeof (buf), 0); syslog(LOG_ERR, "cannot execute %s: %m", sep->se_server); _exit(1); } } if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) close(ctrl); } } } void reapchild(signo) int signo; { int status; pid_t pid; struct servtab *sep; for (;;) { pid = wait3(&status, WNOHANG, (struct rusage *)0); if (pid <= 0) break; if (debug) fprintf(stderr, "%d reaped, status %#x\n", pid, status); for (sep = servtab; sep; sep = sep->se_next) if (sep->se_wait == pid) { if (status) syslog(LOG_WARNING, "%s: exit status 0x%x", sep->se_server, status); 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(signo) int signo; { struct servtab *sep, *cp, **sepp; struct passwd *pwd; long 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()) { if ((pwd = getpwnam(cp->se_user)) == NULL) { syslog(LOG_ERR, "%s/%s: No such user '%s', service ignored", cp->se_service, cp->se_proto, cp->se_user); continue; } for (sep = servtab; sep; sep = sep->se_next) if (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); /* * sep->se_wait may be holding the pid of a daemon * that we're waiting for. If so, don't overwrite * it unless the config file explicitly says don't * wait. */ if (cp->se_bi == 0 && (sep->se_wait == 1 || cp->se_wait == 0)) 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 (ISMUX(sep)) { sep->se_fd = -1; continue; } if (!sep->se_rpc) { sp = getservbyname(sep->se_service, sep->se_proto); if (sp == 0) { syslog(LOG_ERR, "%s/%s: unknown service", sep->se_service, sep->se_proto); sep->se_checked = 0; continue; } if (sp->s_port != sep->se_ctrladdr.sin_port) { sep->se_ctrladdr.sin_family = AF_INET; sep->se_ctrladdr.sin_port = sp->s_port; if (sep->se_fd >= 0) close_sep(sep); } } else { rpc = getrpcbyname(sep->se_service); if (rpc == 0) { syslog(LOG_ERR, "%s/%s unknown RPC service.", sep->se_service, sep->se_proto); if (sep->se_fd != -1) (void) close(sep->se_fd); sep->se_fd = -1; continue; } if (rpc->r_number != sep->se_rpc_prog) { if (sep->se_rpc_prog) unregisterrpc(sep); sep->se_rpc_prog = rpc->r_number; if (sep->se_fd != -1) (void) close(sep->se_fd); sep->se_fd = -1; } } if (sep->se_fd == -1) setup(sep); } endconfig(); /* * Purge anything not looked at above. */ 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 >= 0) close_sep(sep); if (debug) print_service("FREE", sep); if (sep->se_rpc && sep->se_rpc_prog > 0) unregisterrpc(sep); freeconfig(sep); free((char *)sep); } (void) sigsetmask(omask); } void unregisterrpc(sep) struct servtab *sep; { int i; struct servtab *sepp; long omask; omask = sigblock(SIGBLOCK); for (sepp = servtab; sepp; sepp = sepp->se_next) { if (sepp == sep) continue; if (sep->se_checked == 0 || !sepp->se_rpc || sep->se_rpc_prog != sepp->se_rpc_prog) continue; return; } if (debug) print_service("UNREG", sep); for (i = sep->se_rpc_lowvers; i <= sep->se_rpc_highvers; i++) pmap_unset(sep->se_rpc_prog, i); if (sep->se_fd != -1) (void) close(sep->se_fd); sep->se_fd = -1; (void) sigsetmask(omask); } void retry(signo) int signo; { struct servtab *sep; timingout = 0; for (sep = servtab; sep; sep = sep->se_next) if (sep->se_fd == -1) setup(sep); } void setup(sep) struct servtab *sep; { int on = 1; if ((sep->se_fd = socket(AF_INET, sep->se_socktype, 0)) < 0) { if (debug) fprintf(stderr, "socket failed on %s/%s: %s\n", sep->se_service, sep->se_proto, strerror(errno)); 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, (struct sockaddr *)&sep->se_ctrladdr, sizeof (sep->se_ctrladdr)) < 0) { if (debug) fprintf(stderr, "bind failed on %s/%s: %s\n", sep->se_service, sep->se_proto, strerror(errno)); 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_rpc) { int i, len = sizeof(struct sockaddr); if (getsockname(sep->se_fd, (struct sockaddr*)&sep->se_ctrladdr, &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; } if (debug) print_service("REG ", sep); for (i = sep->se_rpc_lowvers; i <= sep->se_rpc_highvers; i++) { pmap_unset(sep->se_rpc_prog, i); pmap_set(sep->se_rpc_prog, i, (sep->se_socktype == SOCK_DGRAM) ? IPPROTO_UDP : IPPROTO_TCP, ntohs(sep->se_ctrladdr.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; if (debug) { fprintf(stderr, "registered %s on %d\n", sep->se_server, sep->se_fd); } } /* * Finish with a service and its socket. */ void close_sep(sep) struct servtab *sep; { if (sep->se_fd >= 0) { nsock--; FD_CLR(sep->se_fd, &allsock); (void) close(sep->se_fd); sep->se_fd = -1; } sep->se_count = 0; /* * Don't keep the pid of this running deamon: when reapchild() * reaps this pid, it would erroneously increment nsock. */ if (sep->se_wait > 1) sep->se_wait = 1; } struct servtab * enter(cp) struct servtab *cp; { struct servtab *sep; long omask; 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[LINE_MAX]; int setconfig() { if (fconfig != NULL) { fseek(fconfig, 0L, SEEK_SET); return (1); } fconfig = fopen(CONFIG, "r"); return (fconfig != NULL); } void endconfig() { if (fconfig) { (void) fclose(fconfig); fconfig = NULL; } } struct servtab * getconfigent() { struct servtab *sep = &serv; int argc; char *cp, *arg; char *versp; static char TCPMUX_TOKEN[] = "tcpmux/"; #define MUX_LEN (sizeof(TCPMUX_TOKEN)-1) more: while ((cp = nextline(fconfig)) && (*cp == '#' || *cp == '\0')) ; if (cp == NULL) return ((struct servtab *)0); /* * clear the static buffer, since some fields (se_ctrladdr, * for example) don't get initialized here. */ memset((caddr_t)sep, 0, sizeof *sep); arg = skip(&cp); if (cp == NULL) { /* got an empty line containing just blanks/tabs. */ goto more; } if (strncmp(arg, TCPMUX_TOKEN, MUX_LEN) == 0) { char *c = arg + MUX_LEN; if (*c == '+') { sep->se_type = MUXPLUS_TYPE; c++; } else sep->se_type = MUX_TYPE; sep->se_service = newstr(c); } else { sep->se_service = newstr(arg); sep->se_type = NORM_TYPE; } arg = sskip(&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 = newstr(sskip(&cp)); if (strncmp(sep->se_proto, "rpc/", 4) == 0) { sep->se_proto += 4; sep->se_rpc = 1; sep->se_rpc_prog = sep->se_rpc_lowvers = sep->se_rpc_lowvers = 0; sep->se_ctrladdr.sin_family = AF_INET; sep->se_ctrladdr.sin_port = 0; sep->se_ctrladdr.sin_addr.s_addr = htonl(INADDR_ANY); if ((versp = rindex(sep->se_service, '/'))) { *versp++ = '\0'; switch (sscanf(versp, "%d-%d", &sep->se_rpc_lowvers, &sep->se_rpc_highvers)) { case 2: break; case 1: sep->se_rpc_highvers = sep->se_rpc_lowvers; break; default: syslog(LOG_ERR, "bad RPC version specifier; %s\n", sep->se_service); freeconfig(sep); goto more; } } else { sep->se_rpc_lowvers = sep->se_rpc_highvers = 1; } } arg = sskip(&cp); sep->se_wait = strcmp(arg, "wait") == 0; if (ISMUX(sep)) { /* * Silently enforce "nowait" for TCPMUX services since * they don't have an assigned port to listen on. */ sep->se_wait = 0; if (strcmp(sep->se_proto, "tcp")) { syslog(LOG_ERR, "%s: bad protocol for tcpmux service %s", CONFIG, sep->se_service); goto more; } if (sep->se_socktype != SOCK_STREAM) { syslog(LOG_ERR, "%s: bad socket type for tcpmux service %s", CONFIG, sep->se_service); goto more; } } sep->se_user = newstr(sskip(&cp)); sep->se_server = newstr(sskip(&cp)); if (strcmp(sep->se_server, "internal") == 0) { 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 unknown", sep->se_service); 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++] = newstr(arg); while (argc <= MAXARGV) sep->se_argv[argc++] = NULL; return (sep); } void freeconfig(cp) 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]); } /* * Safe skip - if skip returns null, log a syntax error in the * configuration file and exit. */ char * sskip(cpp) char **cpp; { char *cp; cp = skip(cpp); if (cp == NULL) { syslog(LOG_ERR, "%s: syntax error", CONFIG); exit(-1); } return (cp); } char * skip(cpp) char **cpp; { char *cp = *cpp; char *start; again: while (*cp == ' ' || *cp == '\t') cp++; if (*cp == '\0') { int c; c = getc(fconfig); (void) ungetc(c, fconfig); if (c == ' ' || c == '\t') if (cp = nextline(fconfig)) goto again; *cpp = (char *)0; return ((char *)0); } 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 = strchr(line, '\n'); if (cp) *cp = '\0'; return (line); } char * newstr(cp) char *cp; { if (cp = strdup(cp ? cp : "")) return (cp); syslog(LOG_ERR, "strdup: %m"); exit(-1); } void setproctitle(a, s) char *a; int s; { int size; char *cp; struct sockaddr_in sin; char buf[80]; cp = Argv[0]; size = sizeof(sin); if (getpeername(s, (struct sockaddr *)&sin, &size) == 0) (void) sprintf(buf, "-%s [%s]", a, inet_ntoa(sin.sin_addr)); else (void) sprintf(buf, "-%s", a); strncpy(cp, buf, LastArg - cp); cp += strlen(cp); while (cp < LastArg) *cp++ = ' '; } /* * Internet services provided internally by inetd: */ #define BUFSIZE 8192 /* ARGSUSED */ void echo_stream(s, sep) /* Echo service -- echo data back */ int s; struct servtab *sep; { char buffer[BUFSIZE]; int i; setproctitle(sep->se_service, s); while ((i = read(s, buffer, sizeof(buffer))) > 0 && write(s, buffer, i) > 0) ; exit(0); } /* ARGSUSED */ void echo_dg(s, sep) /* Echo service -- echo data back */ int s; struct servtab *sep; { char buffer[BUFSIZE]; 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 */ void discard_stream(s, sep) /* Discard service -- ignore data */ int s; struct servtab *sep; { int ret; char buffer[BUFSIZE]; setproctitle(sep->se_service, s); while (1) { while ((ret = read(s, buffer, sizeof(buffer))) > 0) ; if (ret == 0 || errno != EINTR) break; } exit(0); } /* ARGSUSED */ void discard_dg(s, sep) /* Discard service -- ignore data */ int s; struct servtab *sep; { char buffer[BUFSIZE]; (void) read(s, buffer, sizeof(buffer)); } #include #define LINESIZ 72 char ring[128]; char *endring; void initring() { int i; endring = ring; for (i = 0; i <= 128; ++i) if (isprint(i)) *endring++ = i; } /* ARGSUSED */ void chargen_stream(s, sep) /* Character generator */ int s; struct servtab *sep; { int len; char *rs, text[LINESIZ+2]; setproctitle(sep->se_service, s); if (!endring) { initring(); rs = ring; } text[LINESIZ] = '\r'; text[LINESIZ + 1] = '\n'; for (rs = ring;;) { if ((len = endring - rs) >= LINESIZ) memmove(text, rs, LINESIZ); else { memmove(text, rs, len); memmove(text + len, ring, LINESIZ - len); } if (++rs == endring) rs = ring; if (write(s, text, sizeof(text)) != sizeof(text)) break; } exit(0); } /* ARGSUSED */ void chargen_dg(s, sep) /* Character generator */ int s; struct servtab *sep; { struct sockaddr sa; static char *rs; int len, size; char text[LINESIZ+2]; if (endring == 0) { initring(); rs = ring; } size = sizeof(sa); if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0) return; if ((len = endring - rs) >= LINESIZ) memmove(text, rs, LINESIZ); else { memmove(text, rs, len); memmove(text + len, ring, LINESIZ - len); } if (++rs == endring) rs = ring; text[LINESIZ] = '\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) { if (debug) fprintf(stderr, "Unable to get time of day\n"); return (0L); } #define OFFSET ((u_long)25567 * 24*60*60) return (htonl((long)(tv.tv_sec + OFFSET))); #undef OFFSET } /* ARGSUSED */ void machtime_stream(s, sep) int s; struct servtab *sep; { long result; result = machtime(); (void) write(s, (char *) &result, sizeof(result)); } /* ARGSUSED */ void 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 */ void daytime_stream(s, sep) /* Return human-readable time of day */ int s; struct servtab *sep; { char buffer[256]; time_t clock; clock = time((time_t *) 0); (void) sprintf(buffer, "%.24s\r\n", ctime(&clock)); (void) write(s, buffer, strlen(buffer)); } /* ARGSUSED */ void daytime_dg(s, sep) /* Return human-readable time of day */ int s; struct servtab *sep; { char buffer[256]; time_t clock; struct sockaddr sa; int size; clock = time((time_t *) 0); size = sizeof(sa); if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0) return; (void) sprintf(buffer, "%.24s\r\n", ctime(&clock)); (void) sendto(s, buffer, strlen(buffer), 0, &sa, sizeof(sa)); } /* * print_service: * Dump relevant information to stderr */ void print_service(action, sep) char *action; struct servtab *sep; { if(sep->se_rpc) 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, (int)sep->se_bi, sep->se_server); else 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, (int)sep->se_bi, sep->se_server); } /* * Based on TCPMUX.C by Mark K. Lottor November 1988 * sri-nic::ps:tcpmux.c */ static int /* # of characters upto \r,\n or \0 */ getline(fd, buf, len) int fd; char *buf; int len; { int count = 0, n; do { n = read(fd, buf, len-count); if (n == 0) return (count); if (n < 0) return (-1); while (--n >= 0) { if (*buf == '\r' || *buf == '\n' || *buf == '\0') return (count); count++; buf++; } } while (count < len); return (count); } #define MAX_SERV_LEN (256+2) /* 2 bytes for \r\n */ #define strwrite(fd, buf) (void) write(fd, buf, sizeof(buf)-1) struct servtab * tcpmux(s) int s; { struct servtab *sep; char service[MAX_SERV_LEN+1]; int len; /* Get requested service name */ if ((len = getline(s, service, MAX_SERV_LEN)) < 0) { strwrite(s, "-Error reading service name\r\n"); return (NULL); } service[len] = '\0'; if (debug) fprintf(stderr, "tcpmux: someone wants %s\n", service); /* * Help is a required command, and lists available services, * one per line. */ if (!strcasecmp(service, "help")) { for (sep = servtab; sep; sep = sep->se_next) { if (!ISMUX(sep)) continue; (void)write(s,sep->se_service,strlen(sep->se_service)); strwrite(s, "\r\n"); } return (NULL); } /* Try matching a service in inetd.conf with the request */ for (sep = servtab; sep; sep = sep->se_next) { if (!ISMUX(sep)) continue; if (!strcasecmp(service, sep->se_service)) { if (ISMUXPLUS(sep)) { strwrite(s, "+Go\r\n"); } return (sep); } } strwrite(s, "-Service not available\r\n"); return (NULL); }