From owner-freebsd-bugs Wed Oct 7 03:00:06 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id DAA24134 for freebsd-bugs-outgoing; Wed, 7 Oct 1998 03:00:06 -0700 (PDT) (envelope-from owner-freebsd-bugs@FreeBSD.ORG) Received: from freefall.freebsd.org (freefall.FreeBSD.ORG [204.216.27.21]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id DAA24044 for ; Wed, 7 Oct 1998 03:00:02 -0700 (PDT) (envelope-from gnats@FreeBSD.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.8.8/8.8.5) id DAA13976; Wed, 7 Oct 1998 03:00:01 -0700 (PDT) Received: from citadel.cdsec.com (citadel.cdsec.com [192.96.22.18]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id CAA22335 for ; Wed, 7 Oct 1998 02:50:57 -0700 (PDT) (envelope-from gram@cdsec.com) Received: (from nobody@localhost) by citadel.cdsec.com (8.8.8/8.6.9) id LAA09504 for ; Wed, 7 Oct 1998 11:58:45 +0200 (SAST) Received: by citadel via recvmail id 9502; Wed Oct 7 11:58:22 1998 Message-Id: <199810070957.LAA04777@cdsec.com> Date: Wed, 7 Oct 1998 11:57:03 +0200 (SAT) From: gram@cdsec.com Reply-To: gram@cdsec.com To: FreeBSD-gnats-submit@FreeBSD.ORG X-Send-Pr-Version: 3.2 Subject: bin/8183: Signal handlers in inetd.c are unsafe Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >Number: 8183 >Category: bin >Synopsis: Signal handlers in inetd.c are unsafe >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Oct 7 03:00:01 PDT 1998 >Last-Modified: >Originator: Graham Wheeler >Organization: Citadel Data Security >Release: FreeBSD 2.2.7 >Environment: Not important >Description: The signal handlers in inetd.c make use of unsafe functions > such as calls to allocate and free heap memory. This can > result in heap corruption, which is typically manifested > by inetd reporting the error message (from malloc or realloc): > > junk pointer: too low to make sense > >How-To-Repeat: The problem will usually occur if a signal is caught while > in heap allocation function. The signal handler can also > call these functions, which are not reentrant. As this is > timing related, replicating it reliably can be difficult, but > the problem is well known. > >Fix: The following inetd.c fixes the problem, by modifying the signal > handlers to write character flags to a pipe, and having the main > select() loop read these flags and call the original handlers. > The code also adds a new feature to inetd, allowing services > to be bound to specific addresses. This feature is enabled by > using the -X flag. A manual page is appended after the inetd.c > file. ----- inetd.c ---- cut here ------------------------------------ /* * 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 const 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 #if 0 static char sccsid[] = "@(#)from: inetd.c 8.4 (Berkeley) 4/13/94"; #endif static const char rcsid[] = "$Id: inetd.c,v 1.15.2.8 1998/07/18 11:10:26 jkh Exp $"; #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 #include #include #include #include #include #ifdef LOGIN_CAP #include /* see init.c */ #define RESOURCE_RC "daemon" #endif #include "pathnames.h" #ifndef MAXCHILD #define MAXCHILD -1 /* maximum number of this service < 0 = no limit */ #endif #ifndef MAXCPM #define MAXCPM -1 /* rate limit invocations from a single remote address, < 0 = no limit */ #endif #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 MAX_MAXCHLD 32767 /* max allowable max children */ #define SIGBLOCK (sigmask(SIGCHLD)|sigmask(SIGHUP)|sigmask(SIGALRM)) int debug = 0; int log = 0; int extended_format = 0; int nsock, maxsock; fd_set allsock; int options; int timingout; int toomany = TOOMANY; int maxchild = MAXCPM; int maxcpm = MAXCHILD; struct servent *sp; struct rpcent *rpc; struct in_addr bind_address; int signalpipe[2]; struct servtab { char *se_service; /* name of service */ int se_socktype; /* type of socket to use */ char *se_proto; /* protocol used */ int se_maxchild; /* max number of children */ int se_maxcpm; /* max connects per IP per minute */ int se_numchild; /* current number of children */ pid_t *se_pids; /* array of child pids */ char *se_user; /* user name to run as */ char *se_group; /* group name to run as */ #ifdef LOGIN_CAP char *se_class; /* login class name to run with */ #endif 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 */ struct sockaddr_in se_ctrladdr;/* bound address */ u_char se_type; /* type: normal, mux, or mux+ */ u_char se_checked; /* looked at during merge */ u_char se_accept; /* i.e., wait/nowait mode */ u_char 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 TTCP_TYPE 3 #define ISMUX(sep) (((sep)->se_type == MUX_TYPE) || \ ((sep)->se_type == MUXPLUS_TYPE)) #define ISMUXPLUS(sep) ((sep)->se_type == MUXPLUS_TYPE) #define ISTTCP(sep) ((sep)->se_type == TTCP_TYPE) void chargen_dg __P((int, struct servtab *)); void chargen_stream __P((int, struct servtab *)); void close_sep __P((struct servtab *)); void flag_signal __P((char)); void flag_config __P((int)); void config __P((void)); 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 addchild __P((struct servtab *, int)); void flag_reapchild __P((int)); void reapchild __P((void)); void enable __P((struct servtab *)); void disable __P((struct servtab *)); void flag_retry __P((int)); void retry __P((void)); int setconfig __P((void)); void setup __P((struct servtab *)); char *sskip __P((char **)); char *skip __P((char **)); struct servtab *tcpmux __P((int)); int cpmip __P((struct servtab *, 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 */ int bi_maxchild; /* max number of children (default) */ 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 *pid_file = _PATH_INETDPID; #ifdef OLD_SETPROCTITLE char **Argv; char *LastArg; #endif int getvalue(arg, value, whine) char *arg, *whine; int *value; { int tmp; char *p; tmp = strtol(arg, &p, 0); if (tmp < 1 || *p) { syslog(LOG_ERR, whine, arg); return 1; /* failure */ } *value = tmp; return 0; /* success */ } int main(argc, argv, envp) int argc; char *argv[], *envp[]; { struct servtab *sep; struct passwd *pwd; struct group *grp; struct sigaction sa, sapipe; int tmpint, ch, dofork; pid_t pid; char buf[50]; struct sockaddr_in peer; int i; #ifdef LOGIN_CAP login_cap_t *lc = NULL; #endif #ifdef OLD_SETPROCTITLE Argv = argv; if (envp == 0 || *envp == 0) envp = argv; while (*envp) envp++; LastArg = envp[-1] + strlen(envp[-1]); #endif openlog("inetd", LOG_PID | LOG_NOWAIT, LOG_DAEMON); bind_address.s_addr = htonl(INADDR_ANY); while ((ch = getopt(argc, argv, "dlXR:a:c:C:p:")) != -1) switch(ch) { case 'd': debug = 1; options |= SO_DEBUG; break; case 'l': log = 1; break; case 'X': extended_format = 1; break; case 'R': getvalue(optarg, &toomany, "-R %s: bad value for service invocation rate"); break; case 'c': getvalue(optarg, &maxchild, "-c %s: bad value for maximum children"); break; case 'C': getvalue(optarg, &maxcpm, "-C %s: bad value for maximum children/minute"); break; case 'a': if (!inet_aton(optarg, &bind_address)) { syslog(LOG_ERR, "-a %s: invalid IP address", optarg); exit(EX_USAGE); } break; case 'p': pid_file = optarg; break; case '?': default: syslog(LOG_ERR, "usage: inetd [-dl] [-a address] [-R rate]" " [-c maximum] [-C rate]" " [-p pidfile] [conf-file]"); exit(EX_USAGE); } argc -= optind; argv += optind; if (argc > 0) CONFIG = argv[0]; if (debug == 0) { FILE *fp; if (daemon(0, 0) < 0) { syslog(LOG_WARNING, "daemon(0,0) failed: %m"); } /* * In case somebody has started inetd manually, we need to * clear the logname, so that old servers run as root do not * get the user's logname.. */ if (setlogin("") < 0) { syslog(LOG_WARNING, "cannot clear logname: %m"); /* no big deal if it fails.. */ } pid = getpid(); fp = fopen(pid_file, "w"); if (fp) { fprintf(fp, "%ld\n", (long)pid); fclose(fp); } else { syslog(LOG_WARNING, "%s: %m", pid_file); } } sa.sa_flags = 0; sigemptyset(&sa.sa_mask); sigaddset(&sa.sa_mask, SIGALRM); sigaddset(&sa.sa_mask, SIGCHLD); sigaddset(&sa.sa_mask, SIGHUP); sa.sa_handler = flag_retry; sigaction(SIGALRM, &sa, (struct sigaction *)0); config(); sa.sa_handler = flag_config; sigaction(SIGHUP, &sa, (struct sigaction *)0); sa.sa_handler = flag_reapchild; sigaction(SIGCHLD, &sa, (struct sigaction *)0); sa.sa_handler = SIG_IGN; sigaction(SIGPIPE, &sa, &sapipe); { /* space for daemons to overwrite environment for ps */ #define DUMMYSIZE 100 char dummy[DUMMYSIZE]; (void)memset(dummy, 'x', DUMMYSIZE - 1); dummy[DUMMYSIZE - 1] = '\0'; (void)setenv("inetd_dummy", dummy, 1); } if (pipe(signalpipe) != 0) { syslog(LOG_ERR, "pipe: %%m"); exit(EX_OSERR); } FD_SET(signalpipe[0], &allsock); if (signalpipe[0]>maxsock) maxsock = signalpipe[0]; 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; } /* handle any queued signal flags */ if (FD_ISSET(signalpipe[0], &readable)) { int n; if (ioctl(signalpipe[0], FIONREAD, &n) == 0) { while (--n >= 0) { char c; if (read(signalpipe[0], &c, 1) == 1) { if (debug) warnx("Handling signal flag %c", c); switch(c) { case 'A': /* sigalrm */ retry(); break; case 'C': /* sigchld */ reapchild(); break; case 'H': /* sighup */ config(); break; } } else { syslog(LOG_ERR, "read: %m"); exit(EX_OSERR); } } } else { syslog(LOG_ERR, "ioctl: %m"); exit(EX_OSERR); } } for (sep = servtab; n && sep; sep = sep->se_next) if (sep->se_fd != -1 && FD_ISSET(sep->se_fd, &readable)) { n--; if (debug) warnx("someone wants %s", sep->se_service); if (sep->se_accept && sep->se_socktype == SOCK_STREAM) { ctrl = accept(sep->se_fd, (struct sockaddr *)0, (int *)0); if (debug) warnx("accept, ctrl %d", ctrl); if (ctrl < 0) { if (errno != EINTR) syslog(LOG_WARNING, "accept (for %s): %m", sep->se_service); continue; } if (cpmip(sep, ctrl) < 0) { close(ctrl); continue; } if (log) { i = sizeof peer; if (getpeername(ctrl, (struct sockaddr *) &peer, &i)) { syslog(LOG_WARNING, "getpeername(for %s): %m", sep->se_service); close(ctrl); continue; } syslog(LOG_INFO,"%s from %s", sep->se_service, inet_ntoa(peer.sin_addr)); } } 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_accept && sep->se_socktype == SOCK_STREAM) close(ctrl); sigsetmask(0L); sleep(1); continue; } if (pid) addchild(sep, pid); sigsetmask(0L); if (pid == 0) { if (dofork) { if (debug) warnx("+ closing from %d", maxsock); for (tmpint = maxsock; tmpint > 2; tmpint--) if (tmpint != ctrl) (void) close(tmpint); } /* * 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); _exit(0); } } if (sep->se_bi) { (*sep->se_bi->bi_fn)(ctrl, sep); /* NOTREACHED */ } else { if (debug) warnx("%d execl %s", 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(EX_NOUSER); } grp = NULL; if ( sep->se_group != NULL && (grp = getgrnam(sep->se_group)) == NULL ) { syslog(LOG_ERR, "%s/%s: %s: No such group", sep->se_service, sep->se_proto, sep->se_group); if (sep->se_socktype != SOCK_STREAM) recv(0, buf, sizeof (buf), 0); _exit(EX_NOUSER); } if (grp != NULL) pwd->pw_gid = grp->gr_gid; #ifdef LOGIN_CAP if ((lc = login_getclass(sep->se_class)) == NULL) { /* error syslogged by getclass */ syslog(LOG_ERR, "%s/%s: %s: login class error", sep->se_service, sep->se_proto); if (sep->se_socktype != SOCK_STREAM) recv(0, buf, sizeof (buf), 0); _exit(EX_NOUSER); } #endif if (setsid() < 0) { syslog(LOG_ERR, "%s: can't setsid(): %m", sep->se_service); /* _exit(EX_OSERR); not fatal yet */ } #ifdef LOGIN_CAP if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETALL) != 0) { syslog(LOG_ERR, "%s: can't setusercontext(..%s..): %m", sep->se_service, sep->se_user); _exit(EX_OSERR); } #else if (pwd->pw_uid) { if (setlogin(sep->se_user) < 0) { syslog(LOG_ERR, "%s: can't setlogin(%s): %m", sep->se_service, sep->se_user); /* _exit(EX_OSERR); not yet */ } if (setgid(pwd->pw_gid) < 0) { syslog(LOG_ERR, "%s: can't set gid %d: %m", sep->se_service, pwd->pw_gid); _exit(EX_OSERR); } (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(EX_OSERR); } } #endif sigaction(SIGPIPE, &sapipe, (struct sigaction *)0); 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(EX_OSERR); } } if (sep->se_accept && sep->se_socktype == SOCK_STREAM) close(ctrl); } } } /* * Add a signal flag to the signal flag queue for later handling */ void flag_signal(c) char c; { if (write(signalpipe[1], &c, 1) != 1) { syslog(LOG_ERR, "write: %m"); exit(EX_OSERR); } } /* * Record a new child pid for this service. If we've reached the * limit on children, then stop accepting incoming requests. */ void addchild(struct servtab *sep, pid_t pid) { #ifdef SANITY_CHECK if (sep->se_numchild >= sep->se_maxchild) { syslog(LOG_ERR, "%s: %d >= %d", __FUNCTION__, sep->se_numchild, sep->se_maxchild); exit(EX_SOFTWARE); } #endif if (sep->se_maxchild == 0) return; sep->se_pids[sep->se_numchild++] = pid; if (sep->se_numchild == sep->se_maxchild) disable(sep); } /* * Some child process has exited. See if it's on somebody's list. */ void flag_reapchild(signo) int signo; { flag_signal('C'); } void reapchild() { int k, status; pid_t pid; struct servtab *sep; for (;;) { pid = wait3(&status, WNOHANG, (struct rusage *)0); if (pid <= 0) break; if (debug) warnx("%d reaped, status %#x", pid, status); for (sep = servtab; sep; sep = sep->se_next) { for (k = 0; k < sep->se_numchild; k++) if (sep->se_pids[k] == pid) break; if (k == sep->se_numchild) continue; if (sep->se_numchild == sep->se_maxchild) enable(sep); sep->se_pids[k] = sep->se_pids[--sep->se_numchild]; if (status) syslog(LOG_WARNING, "%s[%d]: exit status 0x%x", sep->se_server, pid, status); break; } } } void flag_config(signo) int signo; { flag_signal('H'); } void config() { struct servtab *sep, *new, **sepp; long omask; if (!setconfig()) { syslog(LOG_ERR, "%s: %m", CONFIG); return; } for (sep = servtab; sep; sep = sep->se_next) sep->se_checked = 0; while ((new = getconfigent())) { if (getpwnam(new->se_user) == NULL) { syslog(LOG_ERR, "%s/%s: No such user '%s', service ignored", new->se_service, new->se_proto, new->se_user); continue; } if (new->se_group && getgrnam(new->se_group) == NULL) { syslog(LOG_ERR, "%s/%s: No such group '%s', service ignored", new->se_service, new->se_proto, new->se_group); continue; } #ifdef LOGIN_CAP if (login_getclass(new->se_class) == NULL) { /* error syslogged by getclass */ syslog(LOG_ERR, "%s/%s: login class error, service ignored", new->se_service, new->se_proto); continue; } #endif for (sep = servtab; sep; sep = sep->se_next) if (strcmp(sep->se_service, new->se_service) == 0 && strcmp(sep->se_proto, new->se_proto) == 0 && (!extended_format || sep->se_ctrladdr.sin_addr.s_addr == new->se_ctrladdr.sin_addr.s_addr)) break; if (sep != 0) { int i; #define SWAP(a, b) { typeof(a) c = a; a = b; b = c; } omask = sigblock(SIGBLOCK); /* copy over outstanding child pids */ if (sep->se_maxchild && new->se_maxchild) { new->se_numchild = sep->se_numchild; if (new->se_numchild > new->se_maxchild) new->se_numchild = new->se_maxchild; memcpy(new->se_pids, sep->se_pids, new->se_numchild * sizeof(*new->se_pids)); } SWAP(sep->se_pids, new->se_pids); sep->se_maxchild = new->se_maxchild; sep->se_numchild = new->se_numchild; sep->se_maxcpm = new->se_maxcpm; /* might need to turn on or off service now */ if (sep->se_fd >= 0) { if (sep->se_maxchild && sep->se_numchild == sep->se_maxchild) { if (FD_ISSET(sep->se_fd, &allsock)) disable(sep); } else { if (!FD_ISSET(sep->se_fd, &allsock)) enable(sep); } } sep->se_accept = new->se_accept; SWAP(sep->se_user, new->se_user); SWAP(sep->se_group, new->se_group); #ifdef LOGIN_CAP SWAP(sep->se_class, new->se_class); #endif SWAP(sep->se_server, new->se_server); for (i = 0; i < MAXARGV; i++) SWAP(sep->se_argv[i], new->se_argv[i]); sigsetmask(omask); freeconfig(new); if (debug) print_service("REDO", sep); } else { sep = enter(new); 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; if (!extended_format) sep->se_ctrladdr.sin_addr = bind_address; 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 flag_retry(signo) int signo; { flag_signal('A'); } void retry() { struct servtab *sep; timingout = 0; for (sep = servtab; sep; sep = sep->se_next) if (sep->se_fd == -1 && !ISMUX(sep)) 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) warn("socket failed on %s/%s", sep->se_service, sep->se_proto); 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"); #ifdef SO_PRIVSTATE if (turnon(sep->se_fd, SO_PRIVSTATE) < 0) syslog(LOG_ERR, "setsockopt (SO_PRIVSTATE): %m"); #endif #undef turnon if (sep->se_type == TTCP_TYPE) if (setsockopt(sep->se_fd, IPPROTO_TCP, TCP_NOPUSH, (char *)&on, sizeof (on)) < 0) syslog(LOG_ERR, "setsockopt (TCP_NOPUSH): %m"); if (bind(sep->se_fd, (struct sockaddr *)&sep->se_ctrladdr, sizeof (sep->se_ctrladdr)) < 0) { if (debug) warn("bind failed on %s/%s", sep->se_service, sep->se_proto); 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, 64); enable(sep); if (debug) { warnx("registered %s on %d", 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) { if (FD_ISSET(sep->se_fd, &allsock)) disable(sep); (void) close(sep->se_fd); sep->se_fd = -1; } sep->se_count = 0; sep->se_numchild = 0; /* forget about any existing children */ } 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(EX_OSERR); } *sep = *cp; sep->se_fd = -1; omask = sigblock(SIGBLOCK); sep->se_next = servtab; servtab = sep; sigsetmask(omask); return (sep); } void enable(struct servtab *sep) { if (debug) warnx( "enabling %s, fd %d", sep->se_service, sep->se_fd); #ifdef SANITY_CHECK if (sep->se_fd < 0) { syslog(LOG_ERR, "%s: %s: bad fd", __FUNCTION__, sep->se_service); exit(EX_SOFTWARE); } if (ISMUX(sep)) { syslog(LOG_ERR, "%s: %s: is mux", __FUNCTION__, sep->se_service); exit(EX_SOFTWARE); } if (FD_ISSET(sep->se_fd, &allsock)) { syslog(LOG_ERR, "%s: %s: not off", __FUNCTION__, sep->se_service); exit(EX_SOFTWARE); } #endif FD_SET(sep->se_fd, &allsock); nsock++; if (sep->se_fd > maxsock) maxsock = sep->se_fd; } void disable(struct servtab *sep) { if (debug) warnx( "disabling %s, fd %d", sep->se_service, sep->se_fd); #ifdef SANITY_CHECK if (sep->se_fd < 0) { syslog(LOG_ERR, "%s: %s: bad fd", __FUNCTION__, sep->se_service); exit(EX_SOFTWARE); } if (ISMUX(sep)) { syslog(LOG_ERR, "%s: %s: is mux", __FUNCTION__, sep->se_service); exit(EX_SOFTWARE); } if (!FD_ISSET(sep->se_fd, &allsock)) { syslog(LOG_ERR, "%s: %s: not on", __FUNCTION__, sep->se_service); exit(EX_SOFTWARE); } if (nsock == 0) { syslog(LOG_ERR, "%s: nsock=0", __FUNCTION__); exit(EX_SOFTWARE); } #endif FD_CLR(sep->se_fd, &allsock); nsock--; if (sep->se_fd == maxsock) maxsock--; } 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, *s; 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 (extended_format) { if (strcmp(arg, "any") == 0) sep->se_ctrladdr.sin_addr.s_addr = INADDR_ANY; else sep->se_ctrladdr.sin_addr.s_addr = inet_addr(arg); arg = sskip(&cp); } 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; arg = sskip(&cp); if (strcmp(arg, "tcp/ttcp") == 0) { sep->se_type = TTCP_TYPE; sep->se_proto = newstr("tcp"); } else { sep->se_proto = newstr(arg); } if (strncmp(sep->se_proto, "rpc/", 4) == 0) { memmove(sep->se_proto, sep->se_proto + 4, strlen(sep->se_proto) + 1 - 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; if (!extended_format) sep->se_ctrladdr.sin_addr = bind_address; 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); if (!strncmp(arg, "wait", 4)) sep->se_accept = 0; else if (!strncmp(arg, "nowait", 6)) sep->se_accept = 1; else { syslog(LOG_ERR, "%s: bad wait/nowait for service %s", CONFIG, sep->se_service); goto more; } sep->se_maxchild = maxchild; sep->se_maxcpm = maxcpm; if ((s = strchr(arg, '/')) != NULL) { char *eptr; u_long val; val = strtoul(s + 1, &eptr, 10); if (eptr == s + 1 || val > MAX_MAXCHLD) { syslog(LOG_ERR, "%s: bad max-child for service %s", CONFIG, sep->se_service); goto more; } sep->se_maxchild = val; if (*eptr == '/') sep->se_maxcpm = strtol(eptr + 1, &eptr, 10); /* * explicitly do not check for \0 for future expansion / * backwards compatibility */ } if (ISMUX(sep)) { /* * Silently enforce "nowait" mode for TCPMUX services * since they don't have an assigned port to listen on. */ sep->se_accept = 1; 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)); #ifdef LOGIN_CAP if ((s = strrchr(sep->se_user, '/')) != NULL) { *s = '\0'; sep->se_class = newstr(s + 1); } else sep->se_class = newstr(RESOURCE_RC); #endif if ((s = strrchr(sep->se_user, ':')) != NULL) { *s = '\0'; sep->se_group = newstr(s + 1); } else sep->se_group = NULL; 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_accept = 1; /* force accept mode for built-ins */ sep->se_bi = bi; } else sep->se_bi = NULL; if (sep->se_maxchild < 0) /* apply default max-children */ if (sep->se_bi) sep->se_maxchild = sep->se_bi->bi_maxchild; else sep->se_maxchild = sep->se_accept ? 0 : 1; if (sep->se_maxchild) { sep->se_pids = malloc(sep->se_maxchild * sizeof(*sep->se_pids)); if (sep->se_pids == NULL) { syslog(LOG_ERR, "Out of memory."); exit(EX_OSERR); } } argc = 0; for (arg = skip(&cp); cp; arg = skip(&cp)) if (argc < MAXARGV) { sep->se_argv[argc++] = newstr(arg); } else { syslog(LOG_ERR, "%s: too many arguments for service %s", CONFIG, sep->se_service); goto more; } 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_group) free(cp->se_group); #ifdef LOGIN_CAP if (cp->se_class) free(cp->se_class); #endif if (cp->se_server) free(cp->se_server); if (cp->se_pids) free(cp->se_pids); 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(EX_DATAERR); } return (cp); } char * skip(cpp) char **cpp; { char *cp = *cpp; char *start; char quote = '\0'; 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); } if (*cp == '"' || *cp == '\'') quote = *cp++; start = cp; if (quote) while (*cp && *cp != quote) cp++; else 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(EX_OSERR); } #ifdef OLD_SETPROCTITLE void inetd_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++ = ' '; } #else void inetd_setproctitle(a, s) char *a; int s; { int size; struct sockaddr_in sin; char buf[80]; 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); setproctitle("%s", buf); } #endif /* * 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; inetd_setproctitle(sep->se_service, s); while ((i = read(s, buffer, sizeof(buffer))) > 0 && write(s, buffer, i) > 0) ; exit(0); } int check_loop(sin, sep) struct sockaddr_in *sin; struct servtab *sep; { struct servtab *se2; for (se2 = servtab; se2; se2 = se2->se_next) { if (!se2->se_bi || se2->se_socktype != SOCK_DGRAM) continue; if (sin->sin_port == se2->se_ctrladdr.sin_port) { syslog(LOG_WARNING, "%s/%s:%s/%s loop request REFUSED from %s", sep->se_service, sep->se_proto, se2->se_service, se2->se_proto, inet_ntoa(sin->sin_addr)); return 1; } } return 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_in sin; size = sizeof(sin); if ((i = recvfrom(s, buffer, sizeof(buffer), 0, (struct sockaddr *)&sin, &size)) < 0) return; if (check_loop(&sin, sep)) return; (void) sendto(s, buffer, i, 0, (struct sockaddr *)&sin, sizeof(sin)); } /* ARGSUSED */ void discard_stream(s, sep) /* Discard service -- ignore data */ int s; struct servtab *sep; { int ret; char buffer[BUFSIZE]; inetd_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]; inetd_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_in sin; static char *rs; int len, size; char text[LINESIZ+2]; if (endring == 0) { initring(); rs = ring; } size = sizeof(sin); if (recvfrom(s, text, sizeof(text), 0, (struct sockaddr *)&sin, &size) < 0) return; if (check_loop(&sin, sep)) 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, (struct sockaddr *)&sin, sizeof(sin)); } /* * 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) warnx("unable to get time of day"); 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_in sin; int size; size = sizeof(sin); if (recvfrom(s, (char *)&result, sizeof(result), 0, (struct sockaddr *)&sin, &size) < 0) return; if (check_loop(&sin, sep)) return; result = machtime(); (void) sendto(s, (char *) &result, sizeof(result), 0, (struct sockaddr *)&sin, sizeof(sin)); } /* 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_in sin; int size; clock = time((time_t *) 0); size = sizeof(sin); if (recvfrom(s, buffer, sizeof(buffer), 0, (struct sockaddr *)&sin, &size) < 0) return; if (check_loop(&sin, sep)) return; (void) sprintf(buffer, "%.24s\r\n", ctime(&clock)); (void) sendto(s, buffer, strlen(buffer), 0, (struct sockaddr *)&sin, sizeof(sin)); } /* * print_service: * Dump relevant information to stderr */ void print_service(action, sep) char *action; struct servtab *sep; { fprintf(stderr, #ifdef LOGIN_CAP "%s: %s proto=%s accept=%d max=%d user=%s group=%s class=%s builtin=%x server=%s\n", #else "%s: %s proto=%s accept=%d max=%d user=%s group=%s builtin=%x server=%s\n", #endif action, sep->se_service, sep->se_proto, sep->se_accept, sep->se_maxchild, sep->se_user, sep->se_group, #ifdef LOGIN_CAP sep->se_class, #endif (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; struct sigaction sa; sa.sa_flags = 0; sigemptyset(&sa.sa_mask); sa.sa_handler = SIG_DFL; sigaction(SIGALRM, &sa, (struct sigaction *)0); do { alarm(10); n = read(fd, buf, len-count); alarm(0); 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) warnx("tcpmux: someone wants %s", 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); } #define CPMHSIZE 256 #define CPMHMASK (CPMHSIZE-1) #define CHTGRAN 10 #define CHTSIZE 6 typedef struct CTime { unsigned long ct_Ticks; int ct_Count; } CTime; typedef struct CHash { struct in_addr ch_Addr; time_t ch_LTime; char *ch_Service; CTime ch_Times[CHTSIZE]; } CHash; CHash CHashAry[CPMHSIZE]; int cpmip(sep, ctrl) struct servtab *sep; int ctrl; { struct sockaddr_in rsin; int rsinLen = sizeof(rsin); int r = 0; /* * If getpeername() fails, just let it through (if logging is * enabled the condition is caught elsewhere) */ if (sep->se_maxcpm > 0 && getpeername(ctrl, (struct sockaddr *)&rsin, &rsinLen) == 0 ) { time_t t = time(NULL); int hv = 0xABC3D20F; int i; int cnt = 0; CHash *chBest = NULL; unsigned int ticks = t / CHTGRAN; { char *p; int i; for (i = 0, p = (char *)&rsin.sin_addr; i < sizeof(rsin.sin_addr); ++i, ++p) { hv = (hv << 5) ^ (hv >> 23) ^ *p; } hv = (hv ^ (hv >> 16)); } for (i = 0; i < 5; ++i) { CHash *ch = &CHashAry[(hv + i) & CPMHMASK]; if (rsin.sin_addr.s_addr == ch->ch_Addr.s_addr && ch->ch_Service && strcmp(sep->se_service, ch->ch_Service) == 0) { chBest = ch; break; } if (chBest == NULL || ch->ch_LTime == 0 || ch->ch_LTime < chBest->ch_LTime) { chBest = ch; } } if (rsin.sin_addr.s_addr != chBest->ch_Addr.s_addr || chBest->ch_Service == NULL || strcmp(sep->se_service, chBest->ch_Service) != 0) { chBest->ch_Addr = rsin.sin_addr; if (chBest->ch_Service) free(chBest->ch_Service); chBest->ch_Service = strdup(sep->se_service); bzero(chBest->ch_Times, sizeof(chBest->ch_Times)); } chBest->ch_LTime = t; { CTime *ct = &chBest->ch_Times[ticks % CHTSIZE]; if (ct->ct_Ticks != ticks) { ct->ct_Ticks = ticks; ct->ct_Count = 0; } ++ct->ct_Count; } for (i = 0; i < CHTSIZE; ++i) { CTime *ct = &chBest->ch_Times[i]; if (ct->ct_Ticks <= ticks && ct->ct_Ticks >= ticks - CHTSIZE) { cnt += ct->ct_Count; } } if (cnt * (CHTSIZE * CHTGRAN) / 60 > sep->se_maxcpm) { r = -1; syslog(LOG_ERR, "%s from %s exceeded counts/min (limit %d/min)", sep->se_service, inet_ntoa(rsin.sin_addr), sep->se_maxcpm); } } return(r); } ----- inetd.8 ----- cut here ----------------------------------- .\" 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: inetd.8,v 1.9.2.6 1998/07/18 11:10:23 jkh Exp $ .\" .Dd October 7, 1998 .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 X .Op Fl c Ar maximum .Op Fl C Ar rate .Op Fl a Ar address .Op Fl p Ar filename .Op Fl R Ar rate .Op Ar configuration file .Sh DESCRIPTION The .Nm 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 continues to listen on the socket (except in some cases which will be described below). Essentially, .Nm allows running one daemon to invoke several others, reducing load on the system. .Pp The following options are available: .Bl -tag -width indent .It Fl d Turn on debugging. .It Fl l Turn on logging. .It Fl X Enable the extended config file format. .It Fl c Ar maximum Specify the default maximum number of services that can be invoked. May be overridden on a per-service basis with the "max-child" parameter. .It Fl C Ar rate Specify the default maximum number of times a service can be invoked from a single IP address in one minute; the default is unlimited. May be overridden on a per-service basis with the "max-connections-per-ip-per-minute" parameter. .It Fl R Ar rate Specify the maximum number of times a service can be invoked in one minute; the default is 256. .It Fl a Specify a specific IP address to bind to. .It Fl p Specify an alternate file in which to store the process ID. .El .Pp Upon execution, .Nm 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}[/max-child[/max-connections-per-ip-per-minute]] user[:group][/login-class] server program server program arguments .Ed .Pp If the .Fl X option is given, then each entry has an additional initial field, which is the numeric IP address to which the listening socket should be bound. The special value `any' causes the socket to be bound to INADDR_ANY (the same as if the .Fl X option was not given). .Pp To specify an .No Tn "ONC RPC" Ns -based service, the entry would contain these fields: .Pp .Bd -unfilled -offset indent -compact service name/version socket type rpc/protocol user[:group][/login-class] server program server program arguments .Ed .Pp There are two types of services that .Nm 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 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. TCPMUX requests are only accepted when the multiplexor service itself is enabled, above and beyond and specific TCPMUX-based servers; see the discussion of internal services below. .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 an .No Tn "ONC RPC" Ns -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 . If it is desired that the service is reachable via T/TCP, one should specify .Dq tcp/ttcp . 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 .Nm will take over the socket associated with the service access point, and thus whether .Nm 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 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 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 maximum number of outstanding child processes (or ``threads'') for a ``nowait'' service may be explicitly specified by appending a ``/'' followed by the number to the ``nowait'' keyword. Normally (or if a value of zero is specified) there is no maximum. Otherwise, once the maximum is reached, further connection attempts will be queued up until an existing child process exits. This also works in the case of ``wait'' mode, although a value other than one (the default) might not make sense in some cases. You can also specify the maximum number of connections per minute for a given IP address by appending a ``/'' followed by the number to the maximum number of outstanding child processes. Once the maximum is reached, further connections from this IP address will be dropped until the end of the minute. .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. Optional .Em group part separated by ``:'' allows to specify group name different than default group for this user. Optional .Em login-class part separated by ``/'' allows to specify login class different than default ``daemon'' login class. .Pp The .Em server-program entry should contain the pathname of the program which is to be executed by .Nm when a request is found on its socket. If .Nm 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 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 available in both TCP and UDP versions; the UDP versions will refuse service if the request specifies a reply port corresponding to any internal service. (This is done as a defense against looping attacks; the remote IP address is logged.) For details of these services, consult the appropriate .Tn RFC document. .Pp The TCPMUX-demultiplexing service is also implemented as an internal service. For any TCPMUX-based service to function, the following line must be included in .Pa inetd.conf : .Bd -literal -offset indent tcpmux stream tcp nowait root internal .Ed .Pp When given the .Fl l option .Nm 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 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. Except when started in debugging mode, .Nm records its process ID in the file .Pa /var/run/inetd.pid to assist in reconfiguration. .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 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 to list TCPMUX services in .Pa inetd.conf . .Sh "FILES" .Bl -tag -width /var/run/inetd.pid -compact .It Pa /etc/inetd.conf configuration file. .It Pa /etc/rpc translation of service names to RPC program numbers. .It Pa /etc/services translation of service names to port numbers. .It Pa /var/run/inetd.pid the pid of the currently running .Nm inetd . .El .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 server logs error messages using .Xr syslog 3 . Important error messages and their explanations are: .Pp .Bl -ohang -compact .It Xo .Ar service Ns / Ns Ar protocol .No " server failing (looping), service terminated." .Xc 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: .Bl -enum -offset indent .It There are many hosts requesting the service within a short time period. .It A broken client program is requesting the service too frequently. .It A malicious user is running a program to invoke the service in a denial-of-service attack. .It The invoked service program has an error that causes clients to retry quickly. .El .Pp Use the .Fl R Ar rate option, as described above, to change the rate limit. Once the limit is reached, the service will be reenabled automatically in 10 minutes. .Pp .It Xo .Ar service Ns / Ns Ar protocol : .No \&No such user .Ar user , .No service ignored .Xc .It Xo .Ar service Ns / Ns Ar protocol : .No getpwnam : .Ar user : .No \&No such user .Xc No entry for .Ar user exists in the .Xr passwd 5 database. The first message occurs when .Nm (re)reads the configuration file. The second message occurs when the service is invoked. .Pp .It Xo .Ar service : .No can't set uid .Ar uid .Xc .It Xo .Ar service : .No can't set gid .Ar gid .Xc The user or group ID for the entry's .Ar user field is invalid. .Pp .It "setsockopt(SO_PRIVSTATE): Operation not supported" The .Nm program attempted to renounce the privileged state associated with a socket but was unable to. .El .Sh SEE ALSO .Xr login.conf 5 , .Xr passwd 5 , .Xr rpc 5 , .Xr services 5 , .Xr comsat 8 , .Xr fingerd 8 , .Xr ftpd 8 , .Xr portmap 8 , .Xr rexecd 8 , .Xr rlogind 8 , .Xr rshd 8 , .Xr telnetd 8 , .Xr tftpd 8 .Sh HISTORY The .Nm command appeared in .Bx 4.3 . TCPMUX is based on code and documentation by Mark Lottor. Support for .Tn "ONC RPC" based services is modeled after that provided by .Tn SunOS 4.1. >Audit-Trail: >Unformatted: To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message