/* $OpenBSD: inetd.c,v 1.161 2019/06/28 13:32:48 deraadt Exp $ */ /* * Copyright (c) 1983,1991 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. 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. */ /* * 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 begin with * a space or tab. All fields must be present in each entry. * * service name must be in /etc/services * socket type stream/dgram * protocol must be in /etc/protocols * wait/nowait[.max] single-threaded/multi-threaded, max # * user[.group] or user[:group] user/group to run daemon as * server program full path name * server program arguments maximum of MAXARGS (20) * * For RPC services * service name/version must be in /etc/rpc * socket type stream/dgram * protocol must be in /etc/protocols * wait/nowait[.max] single-threaded/multi-threaded * user[.group] or user[:group] user to run daemon as * server program full path name * server program arguments maximum of MAXARGS (20) * * For non-RPC services, the "service name" can be of the form * hostaddress:servicename, in which case the hostaddress is used * as the host portion of the address to listen on. If hostaddress * consists of a single `*' character, INADDR_ANY is used. * * A line can also consist of just * hostaddress: * where hostaddress is as in the preceding paragraph. Such a line must * have no further fields; the specified hostaddress is remembered and * used for all further lines that have no hostaddress specified, * until the next such line (or EOF). (This is why * is provided to * allow explicit specification of INADDR_ANY.) A line * *: * is implicitly in effect at the beginning of the file. * * The hostaddress specifier may (and often will) contain dots; * the service name must not. * * For RPC services, host-address specifiers are accepted and will * work to some extent; however, because of limitations in the * portmapper interface, it will not work to try to give more than * one line for any given RPC service, even if the host-address * specifiers are different. * * Comment lines are indicated by a `#' in column 1. */ /* * Here's the scoop concerning the user[.:]group feature: * * 1) set-group-option off. * * a) user = root: NO setuid() or setgid() is done * * b) other: setgid(primary group as found in passwd) * initgroups(name, primary group) * setuid() * * 2) set-group-option on. * * a) user = root: setgid(specified group) * NO initgroups() * NO setuid() * * b) other: setgid(specified group) * initgroups(name, specified group) * setuid() * */ #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 #include #include #include "pathnames.h" #define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) #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 */ int debug = 0; int maxsock; int toomany = TOOMANY; int timingout; struct servent *sp; uid_t uid; #ifndef OPEN_MAX #define OPEN_MAX 64 #endif /* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */ #define FD_MARGIN (8) rlim_t rlim_nofile_cur = OPEN_MAX; struct rlimit rlim_nofile; struct servtab { char *se_hostaddr; /* host address to listen on */ char *se_service; /* name of service */ int se_socktype; /* type of socket to use */ int se_family; /* address family */ char *se_proto; /* protocol used */ int se_rpcprog; /* rpc program number */ int se_rpcversl; /* rpc program lowest version */ int se_rpcversh; /* rpc program highest version */ #define isrpcservice(sep) ((sep)->se_rpcversl != 0) pid_t se_wait; /* single threaded server */ short se_checked; /* looked at during merge */ char *se_user; /* user name to run as */ char *se_group; /* group 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 */ union { struct sockaddr se_un_ctrladdr; struct sockaddr_in se_un_ctrladdr_in; struct sockaddr_in6 se_un_ctrladdr_in6; struct sockaddr_un se_un_ctrladdr_un; struct sockaddr_storage se_un_ctrladdr_storage; } se_un; /* bound address */ #define se_ctrladdr se_un.se_un_ctrladdr #define se_ctrladdr_in se_un.se_un_ctrladdr_in #define se_ctrladdr_in6 se_un.se_un_ctrladdr_in6 #define se_ctrladdr_un se_un.se_un_ctrladdr_un #define se_ctrladdr_storage se_un.se_un_ctrladdr_storage int se_ctrladdr_size; int se_max; /* max # of instances of this service */ int se_count; /* number started since se_time */ struct timeval se_time; /* start of se_count */ struct servtab *se_next; struct event se_event; } *servtab; void echo_stream(int, struct servtab *); void discard_stream(int, struct servtab *); void machtime_stream(int, struct servtab *); void daytime_stream(int, struct servtab *); void chargen_stream(int, struct servtab *); void echo_dg(int, struct servtab *); void discard_dg(int, struct servtab *); void machtime_dg(int, struct servtab *); void daytime_dg(int, struct servtab *); void chargen_dg(int, struct servtab *); 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)(int, struct servtab *); } 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 1900 */ { "time", SOCK_STREAM, 0, 0, machtime_stream }, { "time", SOCK_DGRAM, 0, 0, machtime_dg }, /* Return human-readable time */ { "daytime", SOCK_STREAM, 0, 0, daytime_stream }, { "daytime", SOCK_DGRAM, 0, 0, daytime_dg }, /* Familiar character generator */ { "chargen", SOCK_STREAM, 1, 0, chargen_stream }, { "chargen", SOCK_DGRAM, 0, 0, chargen_dg }, { 0 } }; struct event evsig_alrm; struct event evsig_hup; struct event evsig_chld; struct event evsig_term; struct event evsig_int; void config(int, short, void *); void reap(int, short, void *); void retry(int, short, void *); void die(int, short, void *); void spawn(int, short, void *); void gettcp(int, short, void *); int setconfig(void); void endconfig(void); void register_rpc(struct servtab *); void unregister_rpc(struct servtab *); void freeconfig(struct servtab *); void print_service(char *, struct servtab *); void setup(struct servtab *); struct servtab *getconfigent(void); int bump_nofile(void); struct servtab *enter(struct servtab *); int matchconf(struct servtab *, struct servtab *); int dg_broadcast(struct in_addr *in); #define NUMINT (sizeof(intab) / sizeof(struct inent)) char *CONFIG = _PATH_INETDCONF; int dg_badinput(struct sockaddr *sa); void inetd_setproctitle(char *a, int s); void initring(void); u_int32_t machtime(void); int main(int argc, char *argv[]) { int ch; while ((ch = getopt(argc, argv, "dR:")) != -1) switch (ch) { case 'd': debug = 1; break; case 'R': { /* invocation rate */ char *p; int val; val = strtoul(optarg, &p, 0); if (val >= 1 && *p == '\0') { toomany = val; break; } syslog(LOG_ERR, "-R %s: bad value for service invocation rate", optarg); break; } case '?': default: fprintf(stderr, "usage: inetd [-d] [-R rate] [configuration_file]\n"); exit(1); } argc -= optind; argv += optind; uid = getuid(); if (uid != 0) CONFIG = NULL; if (argc > 0) CONFIG = argv[0]; if (CONFIG == NULL) { fprintf(stderr, "inetd: non-root must specify a config file\n"); exit(1); } if (argc > 1) { fprintf(stderr, "inetd: more than one argument specified\n"); exit(1); } umask(022); if (debug == 0) { daemon(0, 0); if (uid == 0) (void) setlogin(""); } if (pledge("stdio rpath cpath getpw dns inet unix proc exec id", NULL) == -1) err(1, "pledge"); if (uid == 0) { gid_t gid = getgid(); /* If run by hand, ensure groups vector gets trashed */ setgroups(1, &gid); } openlog("inetd", LOG_PID | LOG_NOWAIT, LOG_DAEMON); if (getrlimit(RLIMIT_NOFILE, &rlim_nofile) == -1) { syslog(LOG_ERR, "getrlimit: %m"); } else { rlim_nofile_cur = rlim_nofile.rlim_cur; if (rlim_nofile_cur == RLIM_INFINITY) /* ! */ rlim_nofile_cur = OPEN_MAX; } event_init(); signal_set(&evsig_alrm, SIGALRM, retry, NULL); signal_add(&evsig_alrm, NULL); config(0, 0, NULL); signal_set(&evsig_hup, SIGHUP, config, NULL); signal_add(&evsig_hup, NULL); signal_set(&evsig_chld, SIGCHLD, reap, NULL); signal_add(&evsig_chld, NULL); signal_set(&evsig_term, SIGTERM, die, NULL); signal_add(&evsig_term, NULL); signal_set(&evsig_int, SIGINT, die, NULL); signal_add(&evsig_int, NULL); signal(SIGPIPE, SIG_IGN); event_dispatch(); return (0); } void gettcp(int fd, short events, void *xsep) { struct servtab *sep = xsep; int ctrl; if (debug) fprintf(stderr, "someone wants %s\n", sep->se_service); ctrl = accept(sep->se_fd, NULL, NULL); if (debug) fprintf(stderr, "accept, ctrl %d\n", ctrl); if (ctrl == -1) { if (errno != EWOULDBLOCK && errno != EINTR && errno != ECONNABORTED) syslog(LOG_WARNING, "accept (for %s): %m", sep->se_service); return; } if ((sep->se_family == AF_INET || sep->se_family == AF_INET6) && sep->se_socktype == SOCK_STREAM) { struct sockaddr_storage peer; socklen_t plen = sizeof(peer); char sbuf[NI_MAXSERV]; if (getpeername(ctrl, (struct sockaddr *)&peer, &plen) == -1) { syslog(LOG_WARNING, "could not getpeername"); close(ctrl); return; } if (getnameinfo((struct sockaddr *)&peer, plen, NULL, 0, sbuf, sizeof(sbuf), NI_NUMERICSERV) == 0 && strtonum(sbuf, 1, USHRT_MAX, NULL) == 20) { /* * ignore things that look like ftp bounce */ close(ctrl); return; } } spawn(ctrl, 0, sep); } int dg_badinput(struct sockaddr *sa) { struct in_addr in; struct in6_addr *in6; u_int16_t port; switch (sa->sa_family) { case AF_INET: in.s_addr = ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr); port = ntohs(((struct sockaddr_in *)sa)->sin_port); if (IN_MULTICAST(in.s_addr)) goto bad; switch ((in.s_addr & 0xff000000) >> 24) { case 0: case 127: case 255: goto bad; } if (dg_broadcast(&in)) goto bad; break; case AF_INET6: in6 = &((struct sockaddr_in6 *)sa)->sin6_addr; port = ntohs(((struct sockaddr_in6 *)sa)->sin6_port); if (IN6_IS_ADDR_MULTICAST(in6) || IN6_IS_ADDR_UNSPECIFIED(in6)) goto bad; /* * OpenBSD does not support IPv4-mapped and * IPv4-compatible IPv6 addresses (RFC2553). We should * drop the packet. */ if (IN6_IS_ADDR_V4MAPPED(in6) || IN6_IS_ADDR_V4COMPAT(in6)) goto bad; break; default: /* Unsupported AF */ goto bad; } if (port < IPPORT_RESERVED || port == NFS_PORT) goto bad; return (0); bad: return (1); } int dg_broadcast(struct in_addr *in) { struct ifaddrs *ifa, *ifap; struct sockaddr_in *sin; if (getifaddrs(&ifap) == -1) return (0); for (ifa = ifap; ifa; ifa = ifa->ifa_next) { if (ifa->ifa_addr->sa_family != AF_INET || (ifa->ifa_flags & IFF_BROADCAST) == 0) continue; sin = (struct sockaddr_in *)ifa->ifa_broadaddr; if (sin->sin_addr.s_addr == in->s_addr) { freeifaddrs(ifap); return (1); } } freeifaddrs(ifap); return (0); } void reap(int sig, short event, void *arg) { struct servtab *sep; int status; pid_t pid; if (debug) fprintf(stderr, "reaping asked for\n"); for (;;) { if ((pid = wait3(&status, WNOHANG, NULL)) <= 0) { if (pid == -1 && errno == EINTR) continue; break; } if (debug) fprintf(stderr, "%ld reaped, status %x\n", (long)pid, status); for (sep = servtab; sep; sep = sep->se_next) if (sep->se_wait == pid) { if (WIFEXITED(status) && WEXITSTATUS(status)) syslog(LOG_WARNING, "%s: exit status %d", sep->se_server, WEXITSTATUS(status)); else if (WIFSIGNALED(status)) syslog(LOG_WARNING, "%s: exit signal %d", sep->se_server, WTERMSIG(status)); sep->se_wait = 1; event_add(&sep->se_event, NULL); if (debug) fprintf(stderr, "restored %s, fd %d\n", sep->se_service, sep->se_fd); } } } void config(int sig, short event, void *arg) { struct servtab *sep, *cp, **sepp; int add; char protoname[11]; if (!setconfig()) { syslog(LOG_ERR, "%s: %m", CONFIG); exit(1); } for (sep = servtab; sep; sep = sep->se_next) sep->se_checked = 0; cp = getconfigent(); while (cp != NULL) { for (sep = servtab; sep; sep = sep->se_next) if (matchconf(sep, cp)) break; add = 0; if (sep != NULL) { int i; #define SWAP(type, a, b) {type c=(type)a; a=(type)b; b=(type)c;} /* * 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; SWAP(int, cp->se_max, sep->se_max); SWAP(char *, sep->se_user, cp->se_user); SWAP(char *, sep->se_group, cp->se_group); SWAP(char *, sep->se_server, cp->se_server); for (i = 0; i < MAXARGV; i++) SWAP(char *, sep->se_argv[i], cp->se_argv[i]); #undef SWAP if (isrpcservice(sep)) unregister_rpc(sep); sep->se_rpcversl = cp->se_rpcversl; sep->se_rpcversh = cp->se_rpcversh; freeconfig(cp); add = 1; } else { sep = enter(cp); } sep->se_checked = 1; switch (sep->se_family) { case AF_UNIX: if (sep->se_fd != -1) break; sep->se_ctrladdr_size = strlcpy(sep->se_ctrladdr_un.sun_path, sep->se_service, sizeof sep->se_ctrladdr_un.sun_path); if (sep->se_ctrladdr_size >= sizeof sep->se_ctrladdr_un.sun_path) { syslog(LOG_WARNING, "%s/%s: UNIX domain socket " "path too long", sep->se_service, sep->se_proto); goto serv_unknown; } sep->se_ctrladdr_un.sun_family = AF_UNIX; sep->se_ctrladdr_size += 1 + sizeof sep->se_ctrladdr_un.sun_family; (void)unlink(sep->se_service); setup(sep); break; case AF_INET: sep->se_ctrladdr_in.sin_family = AF_INET; /* se_ctrladdr_in was set in getconfigent */ sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in; if (isrpcservice(sep)) { struct rpcent *rp; sep->se_rpcprog = strtonum(sep->se_service, 1, USHRT_MAX, NULL); if (sep->se_rpcprog == 0) { rp = getrpcbyname(sep->se_service); if (rp == 0) { syslog(LOG_ERR, "%s: unknown rpc service", sep->se_service); goto serv_unknown; } sep->se_rpcprog = rp->r_number; } if (sep->se_fd == -1) setup(sep); if (sep->se_fd != -1) register_rpc(sep); } else { u_short port = htons(strtonum(sep->se_service, 1, USHRT_MAX, NULL)); if (!port) { (void)strlcpy(protoname, sep->se_proto, sizeof(protoname)); if (isdigit((unsigned char) protoname[strlen(protoname) - 1])) protoname[strlen(protoname) - 1] = '\0'; sp = getservbyname(sep->se_service, protoname); if (sp == 0) { syslog(LOG_ERR, "%s/%s: unknown service", sep->se_service, sep->se_proto); goto serv_unknown; } port = sp->s_port; } if (port != sep->se_ctrladdr_in.sin_port) { sep->se_ctrladdr_in.sin_port = port; if (sep->se_fd != -1) { event_del(&sep->se_event); (void) close(sep->se_fd); } sep->se_fd = -1; } if (sep->se_fd == -1) setup(sep); } break; case AF_INET6: sep->se_ctrladdr_in6.sin6_family = AF_INET6; /* se_ctrladdr_in was set in getconfigent */ sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in6; if (isrpcservice(sep)) { struct rpcent *rp; sep->se_rpcprog = strtonum(sep->se_service, 1, USHRT_MAX, NULL); if (sep->se_rpcprog == 0) { rp = getrpcbyname(sep->se_service); if (rp == 0) { syslog(LOG_ERR, "%s: unknown rpc service", sep->se_service); goto serv_unknown; } sep->se_rpcprog = rp->r_number; } if (sep->se_fd == -1) setup(sep); if (sep->se_fd != -1) register_rpc(sep); } else { u_short port = htons(strtonum(sep->se_service, 1, USHRT_MAX, NULL)); if (!port) { (void)strlcpy(protoname, sep->se_proto, sizeof(protoname)); if (isdigit((unsigned char) protoname[strlen(protoname) - 1])) protoname[strlen(protoname) - 1] = '\0'; sp = getservbyname(sep->se_service, protoname); if (sp == 0) { syslog(LOG_ERR, "%s/%s: unknown service", sep->se_service, sep->se_proto); goto serv_unknown; } port = sp->s_port; } if (port != sep->se_ctrladdr_in6.sin6_port) { sep->se_ctrladdr_in6.sin6_port = port; if (sep->se_fd != -1) { event_del(&sep->se_event); (void) close(sep->se_fd); } sep->se_fd = -1; } if (sep->se_fd == -1) setup(sep); } break; } serv_unknown: if (cp->se_next != NULL) { struct servtab *tmp = cp; cp = cp->se_next; free(tmp); } else { free(cp); cp = getconfigent(); } if (debug) print_service(add ? "REDO" : "ADD", sep); } endconfig(); /* * Purge anything not looked at above. */ sepp = &servtab; while ((sep = *sepp)) { if (sep->se_checked) { sepp = &sep->se_next; continue; } *sepp = sep->se_next; if (sep->se_fd != -1) { event_del(&sep->se_event); (void) close(sep->se_fd); } if (isrpcservice(sep)) unregister_rpc(sep); if (sep->se_family == AF_UNIX) (void)unlink(sep->se_service); if (debug) print_service("FREE", sep); freeconfig(sep); free(sep); } } void retry(int sig, short events, void *arg) { struct servtab *sep; timingout = 0; for (sep = servtab; sep; sep = sep->se_next) { if (sep->se_fd == -1) { switch (sep->se_family) { case AF_UNIX: case AF_INET: case AF_INET6: setup(sep); if (sep->se_fd != -1 && isrpcservice(sep)) register_rpc(sep); break; } } } } void die(int sig, short events, void *arg) { struct servtab *sep; for (sep = servtab; sep; sep = sep->se_next) { if (sep->se_fd == -1) continue; switch (sep->se_family) { case AF_UNIX: (void)unlink(sep->se_service); break; case AF_INET: case AF_INET6: if (sep->se_wait == 1 && isrpcservice(sep)) unregister_rpc(sep); break; } (void)close(sep->se_fd); } exit(0); } void setup(struct servtab *sep) { int on = 1; int r; mode_t mask = 0; if ((sep->se_fd = socket(sep->se_family, sep->se_socktype, 0)) == -1) { syslog(LOG_ERR, "%s/%s: socket: %m", sep->se_service, sep->se_proto); return; } #define turnon(fd, opt) \ setsockopt(fd, SOL_SOCKET, opt, &on, sizeof (on)) if (strncmp(sep->se_proto, "tcp", 3) == 0 && 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 (isrpcservice(sep)) { struct passwd *pwd; /* * for RPC services, attempt to use a reserved port * if they are going to be running as root. * * Also, zero out the port for all RPC services; let bind() * find one. */ sep->se_ctrladdr_in.sin_port = 0; if (sep->se_user && (pwd = getpwnam(sep->se_user)) && pwd->pw_uid == 0 && uid == 0) r = bindresvport(sep->se_fd, &sep->se_ctrladdr_in); else { r = bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size); if (r == 0) { socklen_t len = sep->se_ctrladdr_size; int saveerrno = errno; /* update se_ctrladdr_in.sin_port */ r = getsockname(sep->se_fd, &sep->se_ctrladdr, &len); if (r <= 0) errno = saveerrno; } } } else { if (sep->se_family == AF_UNIX) mask = umask(0111); r = bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size); if (sep->se_family == AF_UNIX) umask(mask); } if (r == -1) { syslog(LOG_ERR, "%s/%s: bind: %m", sep->se_service, sep->se_proto); (void) close(sep->se_fd); sep->se_fd = -1; if (!timingout) { timingout = 1; alarm(RETRYTIME); } return; } if (sep->se_socktype == SOCK_STREAM) listen(sep->se_fd, 10); if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) { event_set(&sep->se_event, sep->se_fd, EV_READ|EV_PERSIST, gettcp, sep); } else { event_set(&sep->se_event, sep->se_fd, EV_READ|EV_PERSIST, spawn, sep); } event_add(&sep->se_event, NULL); if (sep->se_fd > maxsock) { maxsock = sep->se_fd; if (maxsock > rlim_nofile_cur - FD_MARGIN) bump_nofile(); } } void register_rpc(struct servtab *sep) { socklen_t n; struct sockaddr_in sin; struct protoent *pp; if ((pp = getprotobyname(sep->se_proto+4)) == NULL) { syslog(LOG_ERR, "%s: getproto: %m", sep->se_proto); return; } n = sizeof sin; if (getsockname(sep->se_fd, (struct sockaddr *)&sin, &n) == -1) { syslog(LOG_ERR, "%s/%s: getsockname: %m", sep->se_service, sep->se_proto); return; } for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) { if (debug) fprintf(stderr, "pmap_set: %u %u %u %u\n", sep->se_rpcprog, n, pp->p_proto, ntohs(sin.sin_port)); (void)pmap_unset(sep->se_rpcprog, n); if (!pmap_set(sep->se_rpcprog, n, pp->p_proto, ntohs(sin.sin_port))) syslog(LOG_ERR, "%s %s: pmap_set: %u %u %u %u: %m", sep->se_service, sep->se_proto, sep->se_rpcprog, n, pp->p_proto, ntohs(sin.sin_port)); } } void unregister_rpc(struct servtab *sep) { int n; for (n = sep->se_rpcversl; n <= sep->se_rpcversh; n++) { if (debug) fprintf(stderr, "pmap_unset(%u, %u)\n", sep->se_rpcprog, n); if (!pmap_unset(sep->se_rpcprog, n)) syslog(LOG_ERR, "pmap_unset(%u, %u)", sep->se_rpcprog, n); } } struct servtab * enter(struct servtab *cp) { struct servtab *sep; sep = malloc(sizeof (*sep)); if (sep == NULL) { syslog(LOG_ERR, "Out of memory."); exit(1); } *sep = *cp; sep->se_fd = -1; sep->se_rpcprog = -1; sep->se_next = servtab; servtab = sep; return (sep); } int matchconf(struct servtab *old, struct servtab *new) { if (strcmp(old->se_service, new->se_service) != 0) return (0); if (strcmp(old->se_hostaddr, new->se_hostaddr) != 0) return (0); if (strcmp(old->se_proto, new->se_proto) != 0) return (0); /* * If the new servtab is bound to a specific address, check that the * old servtab is bound to the same entry. If the new service is not * bound to a specific address then the check of se_hostaddr above * is sufficient. */ if (old->se_family == AF_INET && new->se_family == AF_INET && bcmp(&old->se_ctrladdr_in.sin_addr, &new->se_ctrladdr_in.sin_addr, sizeof(new->se_ctrladdr_in.sin_addr)) != 0) return (0); if (old->se_family == AF_INET6 && new->se_family == AF_INET6 && bcmp(&old->se_ctrladdr_in6.sin6_addr, &new->se_ctrladdr_in6.sin6_addr, sizeof(new->se_ctrladdr_in6.sin6_addr)) != 0) return (0); if (old->se_family == AF_INET6 && new->se_family == AF_INET6 && old->se_ctrladdr_in6.sin6_scope_id != new->se_ctrladdr_in6.sin6_scope_id) return (0); return (1); } FILE *fconfig = NULL; char line[1024]; char *defhost; char *skip(char **, int); char *nextline(FILE *); char *newstr(char *); struct servtab *dupconfig(struct servtab *); int setconfig(void) { free(defhost); defhost = newstr("*"); if (fconfig != NULL) { fseek(fconfig, 0L, SEEK_SET); return (1); } fconfig = fopen(CONFIG, "r"); return (fconfig != NULL); } void endconfig(void) { if (fconfig) { (void) fclose(fconfig); fconfig = NULL; } if (defhost) { free(defhost); defhost = 0; } } struct servtab * getconfigent(void) { struct servtab *sep, *tsep; char *arg, *cp, *hostdelim, *s; int argc; sep = calloc(1, sizeof(struct servtab)); if (sep == NULL) { syslog(LOG_ERR, "calloc: %m"); exit(1); } more: freeconfig(sep); while ((cp = nextline(fconfig)) && *cp == '#') ; if (cp == NULL) { free(sep); return (NULL); } memset(sep, 0, sizeof *sep); arg = skip(&cp, 0); if (arg == NULL) { /* A blank line. */ goto more; } /* Check for a host name. */ hostdelim = strrchr(arg, ':'); if (hostdelim) { *hostdelim = '\0'; if (arg[0] == '[' && hostdelim > arg && hostdelim[-1] == ']') { hostdelim[-1] = '\0'; sep->se_hostaddr = newstr(arg + 1); } else if (hostdelim == arg) sep->se_hostaddr = newstr("*"); else sep->se_hostaddr = newstr(arg); arg = hostdelim + 1; /* * If the line is of the form `host:', then just change the * default host for the following lines. */ if (*arg == '\0') { arg = skip(&cp, 0); if (cp == NULL) { free(defhost); defhost = newstr(sep->se_hostaddr); goto more; } } } else sep->se_hostaddr = newstr(defhost); sep->se_service = newstr(arg); if ((arg = skip(&cp, 1)) == NULL) goto more; if (strcmp(arg, "stream") == 0) sep->se_socktype = SOCK_STREAM; else if (strcmp(arg, "dgram") == 0) sep->se_socktype = SOCK_DGRAM; else sep->se_socktype = -1; if ((arg = skip(&cp, 1)) == NULL) goto more; sep->se_proto = newstr(arg); if (strcmp(sep->se_proto, "unix") == 0) { sep->se_family = AF_UNIX; } else { int s; sep->se_family = AF_INET; if (sep->se_proto[strlen(sep->se_proto) - 1] == '6') sep->se_family = AF_INET6; /* check if the family is supported */ s = socket(sep->se_family, SOCK_DGRAM, 0); if (s == -1) { syslog(LOG_WARNING, "%s/%s: %s: the address family is " "not supported by the kernel", sep->se_service, sep->se_proto, sep->se_hostaddr); goto more; } close(s); if (strncmp(sep->se_proto, "rpc/", 4) == 0) { char *cp, *ccp; long l; cp = strchr(sep->se_service, '/'); if (cp == 0) { syslog(LOG_ERR, "%s: no rpc version", sep->se_service); goto more; } *cp++ = '\0'; l = strtol(cp, &ccp, 0); if (ccp == cp || l < 0 || l > INT_MAX) { badafterall: syslog(LOG_ERR, "%s/%s: bad rpc version", sep->se_service, cp); goto more; } sep->se_rpcversl = sep->se_rpcversh = l; if (*ccp == '-') { cp = ccp + 1; l = strtol(cp, &ccp, 0); if (ccp == cp || l < 0 || l > INT_MAX || l < sep->se_rpcversl || *ccp) goto badafterall; sep->se_rpcversh = l; } else if (*ccp != '\0') goto badafterall; } } arg = skip(&cp, 1); if (arg == NULL) goto more; s = strchr(arg, '.'); if (s) { char *p; *s++ = '\0'; sep->se_max = strtoul(s, &p, 0); if (sep->se_max < 1 || *p) { syslog(LOG_ERR, "%s: illegal max field \"%s\", setting to %d", sep->se_service, s, toomany); sep->se_max = toomany; } } else sep->se_max = toomany; sep->se_wait = strcmp(arg, "wait") == 0; if ((arg = skip(&cp, 1)) == NULL) goto more; sep->se_user = newstr(arg); arg = strchr(sep->se_user, '.'); if (arg == NULL) arg = strchr(sep->se_user, ':'); if (arg) { *arg++ = '\0'; sep->se_group = newstr(arg); } if ((arg = skip(&cp, 1)) == NULL) goto more; sep->se_server = newstr(arg); 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, 0); cp; arg = skip(&cp, 0)) { if (argc < MAXARGV) sep->se_argv[argc++] = newstr(arg); } if (argc == 0 && sep->se_bi == NULL) { if ((arg = strrchr(sep->se_server, '/')) != NULL) arg++; else arg = sep->se_server; sep->se_argv[argc++] = newstr(arg); } while (argc <= MAXARGV) sep->se_argv[argc++] = NULL; /* * Resolve each hostname in the se_hostaddr list (if any) * and create a new entry for each resolved address. */ if (sep->se_hostaddr != NULL && strcmp(sep->se_proto, "unix") != 0) { struct addrinfo hints, *res0, *res; char *host, *hostlist0, *hostlist, *port; int error; hostlist = hostlist0 = sep->se_hostaddr; sep->se_hostaddr = NULL; sep->se_checked = -1; while ((host = strsep(&hostlist, ",")) != NULL) { if (*host == '\0') continue; memset(&hints, 0, sizeof(hints)); hints.ai_family = sep->se_family; hints.ai_socktype = sep->se_socktype; hints.ai_flags = AI_PASSIVE; port = "0"; error = getaddrinfo(strcmp(host, "*") ? host : NULL, port, &hints, &res0); if (error) { syslog(LOG_ERR, "%s/%s: %s: %s", sep->se_service, sep->se_proto, host, gai_strerror(error)); continue; } for (res = res0; res; res = res->ai_next) { /* * If sep is unused, store host in there. * Otherwise, dup a new entry and prepend it. */ if (sep->se_checked == -1) { sep->se_checked = 0; } else { tsep = dupconfig(sep); tsep->se_next = sep; sep = tsep; } sep->se_hostaddr = newstr(host); memcpy(&sep->se_ctrladdr_storage, res->ai_addr, res->ai_addrlen); sep->se_ctrladdr_size = res->ai_addrlen; } freeaddrinfo(res0); } free(hostlist0); if (sep->se_checked == -1) goto more; /* no resolvable names/addresses */ } return (sep); } void freeconfig(struct servtab *cp) { int i; free(cp->se_hostaddr); cp->se_hostaddr = NULL; free(cp->se_service); cp->se_service = NULL; free(cp->se_proto); cp->se_proto = NULL; free(cp->se_user); cp->se_user = NULL; free(cp->se_group); cp->se_group = NULL; free(cp->se_server); cp->se_server = NULL; for (i = 0; i < MAXARGV; i++) { free(cp->se_argv[i]); cp->se_argv[i] = NULL; } } char * skip(char **cpp, int report) { char *cp = *cpp; char *start; erp: if (*cpp == NULL) { if (report) syslog(LOG_ERR, "syntax error in inetd config file"); return (NULL); } 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 = NULL; goto erp; } start = cp; while (*cp && *cp != ' ' && *cp != '\t') cp++; if (*cp != '\0') *cp++ = '\0'; if ((*cpp = cp) == NULL) goto erp; return (start); } char * nextline(FILE *fd) { if (fgets(line, sizeof (line), fd) == NULL) return (NULL); line[strcspn(line, "\n")] = '\0'; return (line); } char * newstr(char *cp) { if ((cp = strdup(cp ? cp : ""))) return(cp); syslog(LOG_ERR, "strdup: %m"); exit(1); } struct servtab * dupconfig(struct servtab *sep) { struct servtab *newtab; int argc; newtab = calloc(1, sizeof(struct servtab)); if (newtab == NULL) { syslog(LOG_ERR, "calloc: %m"); exit(1); } newtab->se_service = sep->se_service ? newstr(sep->se_service) : NULL; newtab->se_socktype = sep->se_socktype; newtab->se_family = sep->se_family; newtab->se_proto = sep->se_proto ? newstr(sep->se_proto) : NULL; newtab->se_rpcprog = sep->se_rpcprog; newtab->se_rpcversl = sep->se_rpcversl; newtab->se_rpcversh = sep->se_rpcversh; newtab->se_wait = sep->se_wait; newtab->se_user = sep->se_user ? newstr(sep->se_user) : NULL; newtab->se_group = sep->se_group ? newstr(sep->se_group) : NULL; newtab->se_bi = sep->se_bi; newtab->se_server = sep->se_server ? newstr(sep->se_server) : 0; for (argc = 0; argc <= MAXARGV; argc++) newtab->se_argv[argc] = sep->se_argv[argc] ? newstr(sep->se_argv[argc]) : NULL; newtab->se_max = sep->se_max; return (newtab); } void inetd_setproctitle(char *a, int s) { socklen_t size; struct sockaddr_storage ss; char hbuf[NI_MAXHOST]; size = sizeof(ss); if (getpeername(s, (struct sockaddr *)&ss, &size) == 0) { if (getnameinfo((struct sockaddr *)&ss, size, hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST) == 0) setproctitle("-%s [%s]", a, hbuf); else setproctitle("-%s [?]", a); } else setproctitle("-%s", a); } int bump_nofile(void) { #define FD_CHUNK 32 struct rlimit rl; if (getrlimit(RLIMIT_NOFILE, &rl) == -1) { syslog(LOG_ERR, "getrlimit: %m"); return -1; } rl.rlim_cur = MINIMUM(rl.rlim_max, rl.rlim_cur + FD_CHUNK); rl.rlim_cur = MINIMUM(FD_SETSIZE, rl.rlim_cur + FD_CHUNK); if (rl.rlim_cur <= rlim_nofile_cur) { syslog(LOG_ERR, "bump_nofile: cannot extend file limit, max = %d", (int)rl.rlim_cur); return -1; } if (setrlimit(RLIMIT_NOFILE, &rl) == -1) { syslog(LOG_ERR, "setrlimit: %m"); return -1; } rlim_nofile_cur = rl.rlim_cur; return 0; } /* * Internet services provided internally by inetd: */ #define BUFSIZE 4096 void echo_stream(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); } void echo_dg(int s, struct servtab *sep) { char buffer[BUFSIZE]; int i; socklen_t size; struct sockaddr_storage ss; size = sizeof(ss); if ((i = recvfrom(s, buffer, sizeof(buffer), 0, (struct sockaddr *)&ss, &size)) == -1) return; if (dg_badinput((struct sockaddr *)&ss)) return; (void) sendto(s, buffer, i, 0, (struct sockaddr *)&ss, size); } void discard_stream(int s, struct servtab *sep) { char buffer[BUFSIZE]; inetd_setproctitle(sep->se_service, s); while ((errno = 0, read(s, buffer, sizeof(buffer)) > 0) || errno == EINTR) ; exit(0); } void discard_dg(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(void) { int i; endring = ring; for (i = 0; i <= sizeof ring; ++i) if (isprint((unsigned char)i)) *endring++ = i; } void chargen_stream(int s, struct servtab *sep) { char *rs; int len; char 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); } void chargen_dg(int s, struct servtab *sep) { struct sockaddr_storage ss; static char *rs; int len; socklen_t size; char text[LINESIZ+2]; if (endring == 0) { initring(); rs = ring; } size = sizeof(ss); if (recvfrom(s, text, sizeof(text), 0, (struct sockaddr *)&ss, &size) == -1) return; if (dg_badinput((struct sockaddr *)&ss)) 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 *)&ss, size); } /* * 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. */ u_int32_t machtime(void) { struct timeval tv; if (gettimeofday(&tv, NULL) == -1) return (0L); return (htonl((u_int32_t)tv.tv_sec + 2208988800UL)); } void machtime_stream(int s, struct servtab *sep) { u_int32_t result; result = machtime(); (void) write(s, &result, sizeof(result)); } void machtime_dg(int s, struct servtab *sep) { u_int32_t result; struct sockaddr_storage ss; socklen_t size; size = sizeof(ss); if (recvfrom(s, &result, sizeof(result), 0, (struct sockaddr *)&ss, &size) == -1) return; if (dg_badinput((struct sockaddr *)&ss)) return; result = machtime(); (void) sendto(s, &result, sizeof(result), 0, (struct sockaddr *)&ss, size); } /* Return human-readable time of day */ void daytime_stream(int s, struct servtab *sep) { char buffer[256]; time_t clock; clock = time(NULL); (void) snprintf(buffer, sizeof buffer, "%.24s\r\n", ctime(&clock)); (void) write(s, buffer, strlen(buffer)); } /* Return human-readable time of day */ void daytime_dg(int s, struct servtab *sep) { char buffer[256]; time_t clock; struct sockaddr_storage ss; socklen_t size; clock = time(NULL); size = sizeof(ss); if (recvfrom(s, buffer, sizeof(buffer), 0, (struct sockaddr *)&ss, &size) == -1) return; if (dg_badinput((struct sockaddr *)&ss)) return; (void) snprintf(buffer, sizeof buffer, "%.24s\r\n", ctime(&clock)); (void) sendto(s, buffer, strlen(buffer), 0, (struct sockaddr *)&ss, size); } /* * print_service: * Dump relevant information to stderr */ void print_service(char *action, struct servtab *sep) { if (strcmp(sep->se_hostaddr, "*") == 0) fprintf(stderr, "%s: %s ", action, sep->se_service); else fprintf(stderr, "%s: %s:%s ", action, sep->se_hostaddr, sep->se_service); if (isrpcservice(sep)) fprintf(stderr, "rpcprog=%d, rpcvers=%d/%d, proto=%s,", sep->se_rpcprog, sep->se_rpcversh, sep->se_rpcversl, sep->se_proto); else fprintf(stderr, "proto=%s,", sep->se_proto); fprintf(stderr, " wait.max=%d.%d user:group=%s:%s builtin=%lx server=%s\n", sep->se_wait, sep->se_max, sep->se_user, sep->se_group ? sep->se_group : "wheel", (long)sep->se_bi, sep->se_server); } void spawn(int ctrl, short events, void *xsep) { struct servtab *sep = xsep; struct passwd *pwd; int tmpint, dofork; struct group *grp = NULL; char buf[50]; pid_t pid; if (debug) fprintf(stderr, "someone wants %s\n", sep->se_service); pid = 0; dofork = (sep->se_bi == 0 || sep->se_bi->bi_fork); if (dofork) { if (sep->se_count++ == 0) (void)gettimeofday(&sep->se_time, NULL); else if (sep->se_count >= sep->se_max) { struct timeval now; (void)gettimeofday(&now, NULL); if (now.tv_sec - sep->se_time.tv_sec > CNT_INTVL) { sep->se_time = now; sep->se_count = 1; } else { if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) close(ctrl); if (sep->se_family == AF_INET && ntohs(sep->se_ctrladdr_in.sin_port) >= IPPORT_RESERVED) { /* * Cannot close it -- there are * thieves on the system. * Simply ignore the connection. */ --sep->se_count; return; } syslog(LOG_ERR, "%s/%s server failing (looping), service terminated", sep->se_service, sep->se_proto); if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) close(ctrl); event_del(&sep->se_event); (void) close(sep->se_fd); sep->se_fd = -1; sep->se_count = 0; if (!timingout) { timingout = 1; alarm(RETRYTIME); } return; } } pid = fork(); } if (pid == -1) { syslog(LOG_ERR, "fork: %m"); if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) close(ctrl); sleep(1); return; } if (pid && sep->se_wait) { sep->se_wait = pid; event_del(&sep->se_event); } if (pid == 0) { if (sep->se_bi) { if (dofork && pledge("stdio inet", NULL) == -1) err(1, "pledge"); (*sep->se_bi->bi_fn)(ctrl, sep); } else { if ((pwd = getpwnam(sep->se_user)) == NULL) { syslog(LOG_ERR, "getpwnam: %s: No such user", sep->se_user); if (sep->se_socktype != SOCK_STREAM) recv(0, buf, sizeof (buf), 0); exit(1); } if (setsid() <0) syslog(LOG_ERR, "%s: setsid: %m", sep->se_service); if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) { syslog(LOG_ERR, "getgrnam: %s: No such group", sep->se_group); if (sep->se_socktype != SOCK_STREAM) recv(0, buf, sizeof (buf), 0); exit(1); } if (uid != 0) { /* a user running private inetd */ if (uid != pwd->pw_uid) exit(1); } else { tmpint = LOGIN_SETALL & ~(LOGIN_SETGROUP|LOGIN_SETLOGIN); if (pwd->pw_uid) tmpint |= LOGIN_SETGROUP|LOGIN_SETLOGIN; if (sep->se_group) { pwd->pw_gid = grp->gr_gid; tmpint |= LOGIN_SETGROUP; } if (setusercontext(NULL, pwd, pwd->pw_uid, tmpint) == -1) { syslog(LOG_ERR, "%s/%s: setusercontext: %m", sep->se_service, sep->se_proto); exit(1); } } if (debug) fprintf(stderr, "%ld execv %s\n", (long)getpid(), sep->se_server); if (ctrl != STDIN_FILENO) { dup2(ctrl, STDIN_FILENO); close(ctrl); } dup2(STDIN_FILENO, STDOUT_FILENO); dup2(STDIN_FILENO, STDERR_FILENO); closelog(); closefrom(3); signal(SIGPIPE, SIG_DFL); execv(sep->se_server, sep->se_argv); if (sep->se_socktype != SOCK_STREAM) recv(0, buf, sizeof (buf), 0); syslog(LOG_ERR, "execv %s: %m", sep->se_server); exit(1); } } if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) close(ctrl); }