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inetd.c
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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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. 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.
*/
#include <sys/cdefs.h>
#ifndef lint
__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
#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 begin with
* a space or tab. All fields must be present in each entry.
*
* service name must be in /etc/services
* or name a tcpmux service
* or specify a unix domain socket
* socket type stream/dgram/raw/rdm/seqpacket
* protocol tcp[4][6], udp[4][6], unix
* wait/nowait single-threaded/multi-threaded
* user[:group][/login-class] user/group/login-class 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 rpc/tcp[4][6], rpc/udp[4][6]
* wait/nowait single-threaded/multi-threaded
* user[:group][/login-class] user/group/login-class to run daemon as
* server program full path name
* server program arguments maximum of MAXARGS
*
* Comment lines are indicated by a `#' in column 1.
*
* #ifdef IPSEC
* Comment lines that start with "#@" denote IPsec policy string, as described
* in ipsec_set_policy(3). This will affect all the following items in
* inetd.conf(8). To reset the policy, just use "#@" line. By default,
* there's no IPsec policy.
* #endif
*/
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#include <ctype.h>
#include <errno.h>
#include <err.h>
#include <fcntl.h>
#include <grp.h>
#include <libutil.h>
#include <limits.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <syslog.h>
#ifdef LIBWRAP
#include <tcpd.h>
#endif
#include <unistd.h>
#include "inetd.h"
#include "pathnames.h"
#ifdef IPSEC
#include <netipsec/ipsec.h>
#ifndef IPSEC_POLICY_IPSEC /* no ipsec support on old ipsec */
#undef IPSEC
#endif
#endif
#ifndef LIBWRAP_ALLOW_FACILITY
# define LIBWRAP_ALLOW_FACILITY LOG_AUTH
#endif
#ifndef LIBWRAP_ALLOW_SEVERITY
# define LIBWRAP_ALLOW_SEVERITY LOG_INFO
#endif
#ifndef LIBWRAP_DENY_FACILITY
# define LIBWRAP_DENY_FACILITY LOG_AUTH
#endif
#ifndef LIBWRAP_DENY_SEVERITY
# define LIBWRAP_DENY_SEVERITY LOG_WARNING
#endif
#define ISWRAP(sep) \
( ((wrap_ex && !(sep)->se_bi) || (wrap_bi && (sep)->se_bi)) \
&& (sep->se_family == AF_INET || sep->se_family == AF_INET6) \
&& ( ((sep)->se_accept && (sep)->se_socktype == SOCK_STREAM) \
|| (sep)->se_socktype == SOCK_DGRAM))
#ifdef LOGIN_CAP
#include <login_cap.h>
/* see init.c */
#define RESOURCE_RC "daemon"
#endif
#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
#ifndef MAXPERIP
#define MAXPERIP -1 /* maximum number of this service
from a single remote address,
< 0 = no limit */
#endif
#ifndef TOOMANY
#define TOOMANY 256 /* don't start more than TOOMANY */
#endif
#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))
#define satosin(sa) ((struct sockaddr_in *)(void *)sa)
#define csatosin(sa) ((const struct sockaddr_in *)(const void *)sa)
#ifdef INET6
#define satosin6(sa) ((struct sockaddr_in6 *)(void *)sa)
#define csatosin6(sa) ((const struct sockaddr_in6 *)(const void *)sa)
#endif
static void close_sep(struct servtab *);
static void flag_signal(int);
static void config(void);
static int cpmip(const struct servtab *, int);
static void endconfig(void);
static struct servtab *enter(struct servtab *);
static void freeconfig(struct servtab *);
static struct servtab *getconfigent(void);
static int matchservent(const char *, const char *, const char *);
static char *nextline(FILE *);
static void addchild(struct servtab *, int);
static void reapchild(void);
static void enable(struct servtab *);
static void disable(struct servtab *);
static void retry(void);
static int setconfig(void);
static void setup(struct servtab *);
#ifdef IPSEC
static void ipsecsetup(struct servtab *);
#endif
static void unregisterrpc(register struct servtab *sep);
static struct conninfo *search_conn(struct servtab *sep, int ctrl);
static int room_conn(struct servtab *sep, struct conninfo *conn);
static void addchild_conn(struct conninfo *conn, pid_t pid);
static void reapchild_conn(pid_t pid);
static void free_conn(struct conninfo *conn);
static void resize_conn(struct servtab *sep, int maxperip);
static void free_connlist(struct servtab *sep);
static void free_proc(struct procinfo *);
static struct procinfo *search_proc(pid_t pid, int add);
static int hashval(char *p, int len);
static char *skip(char **);
static char *sskip(char **);
static char *newstr(const char *);
static void print_service(const char *, const struct servtab *);
#ifdef LIBWRAP
/* tcpd.h */
int allow_severity;
int deny_severity;
#endif
static int wrap_ex = 0;
static int wrap_bi = 0;
int debug = 0;
static int dolog = 0;
static int maxsock; /* highest-numbered descriptor */
static fd_set allsock;
static int options;
static int timingout;
static int toomany = TOOMANY;
static int maxchild = MAXCHILD;
static int maxcpm = MAXCPM;
static int maxperip = MAXPERIP;
static struct servent *sp;
static struct rpcent *rpc;
static char *hostname = NULL;
static struct sockaddr_in *bind_sa4;
static int v4bind_ok = 0;
#ifdef INET6
static struct sockaddr_in6 *bind_sa6;
static int v6bind_ok = 0;
#endif
static int signalpipe[2];
#ifdef SANITY_CHECK
static int nsock;
#endif
static uid_t euid;
static gid_t egid;
static mode_t mask;
struct servtab *servtab;
static const char *CONFIG = _PATH_INETDCONF;
static const char *pid_file = _PATH_INETDPID;
static struct pidfh *pfh = NULL;
static struct netconfig *udpconf, *tcpconf, *udp6conf, *tcp6conf;
static LIST_HEAD(, procinfo) proctable[PERIPSIZE];
static int
getvalue(const char *arg, int *value, const char *whine)
{
int tmp;
char *p;
tmp = strtol(arg, &p, 0);
if (tmp < 0 || *p) {
syslog(LOG_ERR, whine, arg);
return 1; /* failure */
}
*value = tmp;
return 0; /* success */
}
#ifdef LIBWRAP
static sa_family_t
whichaf(struct request_info *req)
{
struct sockaddr *sa;
sa = (struct sockaddr *)req->client->sin;
if (sa == NULL)
return AF_UNSPEC;
#ifdef INET6
if (sa->sa_family == AF_INET6 &&
IN6_IS_ADDR_V4MAPPED(&satosin6(sa)->sin6_addr))
return AF_INET;
#endif
return sa->sa_family;
}
#endif
int
main(int argc, char **argv)
{
struct servtab *sep;
struct passwd *pwd;
struct group *grp;
struct sigaction sa, saalrm, sachld, sahup, sapipe;
int ch, dofork;
pid_t pid;
char buf[50];
#ifdef LOGIN_CAP
login_cap_t *lc = NULL;
#endif
#ifdef LIBWRAP
struct request_info req;
int denied;
char *service = NULL;
#endif
struct sockaddr_storage peer;
int i;
struct addrinfo hints, *res;
const char *servname;
int error;
struct conninfo *conn;
openlog("inetd", LOG_PID | LOG_NOWAIT | LOG_PERROR, LOG_DAEMON);
while ((ch = getopt(argc, argv, "dlwWR:a:c:C:p:s:")) != -1)
switch(ch) {
case 'd':
debug = 1;
options |= SO_DEBUG;
break;
case 'l':
dolog = 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':
hostname = optarg;
break;
case 'p':
pid_file = optarg;
break;
case 's':
getvalue(optarg, &maxperip,
"-s %s: bad value for maximum children per source address");
break;
case 'w':
wrap_ex++;
break;
case 'W':
wrap_bi++;
break;
case '?':
default:
syslog(LOG_ERR,
"usage: inetd [-dlWw] [-a address] [-C rate]"
" [-c maximum] [-p filename] [-R rate]"
" [-s maximum] [configuration_file]");
exit(EX_USAGE);
}
/*
* Initialize Bind Addrs.
* When hostname is NULL, wild card bind addrs are obtained from
* getaddrinfo(). But getaddrinfo() requires at least one of
* hostname or servname is non NULL.
* So when hostname is NULL, set dummy value to servname.
* Since getaddrinfo() doesn't accept numeric servname, and
* we doesn't use ai_socktype of struct addrinfo returned
* from getaddrinfo(), we set dummy value to ai_socktype.
*/
servname = (hostname == NULL) ? "0" /* dummy */ : NULL;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_flags = AI_PASSIVE;
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM; /* dummy */
error = getaddrinfo(hostname, servname, &hints, &res);
if (error != 0) {
syslog(LOG_ERR, "-a %s: %s", hostname, gai_strerror(error));
if (error == EAI_SYSTEM)
syslog(LOG_ERR, "%s", strerror(errno));
exit(EX_USAGE);
}
do {
if (res->ai_addr == NULL) {
syslog(LOG_ERR, "-a %s: getaddrinfo failed", hostname);
exit(EX_USAGE);
}
switch (res->ai_addr->sa_family) {
case AF_INET:
if (v4bind_ok)
continue;
bind_sa4 = satosin(res->ai_addr);
/* init port num in case servname is dummy */
bind_sa4->sin_port = 0;
v4bind_ok = 1;
continue;
#ifdef INET6
case AF_INET6:
if (v6bind_ok)
continue;
bind_sa6 = satosin6(res->ai_addr);
/* init port num in case servname is dummy */
bind_sa6->sin6_port = 0;
v6bind_ok = 1;
continue;
#endif
}
if (v4bind_ok
#ifdef INET6
&& v6bind_ok
#endif
)
break;
} while ((res = res->ai_next) != NULL);
if (!v4bind_ok
#ifdef INET6
&& !v6bind_ok
#endif
) {
syslog(LOG_ERR, "-a %s: unknown address family", hostname);
exit(EX_USAGE);
}
euid = geteuid();
egid = getegid();
umask(mask = umask(0777));
argc -= optind;
argv += optind;
if (argc > 0)
CONFIG = argv[0];
if (access(CONFIG, R_OK) < 0)
syslog(LOG_ERR, "Accessing %s: %m, continuing anyway.", CONFIG);
if (debug == 0) {
pid_t otherpid;
pfh = pidfile_open(pid_file, 0600, &otherpid);
if (pfh == NULL) {
if (errno == EEXIST) {
syslog(LOG_ERR, "%s already running, pid: %d",
getprogname(), otherpid);
exit(EX_OSERR);
}
syslog(LOG_WARNING, "pidfile_open() failed: %m");
}
if (daemon(0, 0) < 0) {
syslog(LOG_WARNING, "daemon(0,0) failed: %m");
}
/* From now on we don't want syslog messages going to stderr. */
closelog();
openlog("inetd", LOG_PID | LOG_NOWAIT, LOG_DAEMON);
/*
* 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.. */
}
if (pfh != NULL && pidfile_write(pfh) == -1) {
syslog(LOG_WARNING, "pidfile_write(): %m");
}
}
if (madvise(NULL, 0, MADV_PROTECT) != 0)
syslog(LOG_WARNING, "madvise() failed: %s", strerror(errno));
for (i = 0; i < PERIPSIZE; ++i)
LIST_INIT(&proctable[i]);
if (v4bind_ok) {
udpconf = getnetconfigent("udp");
tcpconf = getnetconfigent("tcp");
if (udpconf == NULL || tcpconf == NULL) {
syslog(LOG_ERR, "unknown rpc/udp or rpc/tcp");
exit(EX_USAGE);
}
}
#ifdef INET6
if (v6bind_ok) {
udp6conf = getnetconfigent("udp6");
tcp6conf = getnetconfigent("tcp6");
if (udp6conf == NULL || tcp6conf == NULL) {
syslog(LOG_ERR, "unknown rpc/udp6 or rpc/tcp6");
exit(EX_USAGE);
}
}
#endif
sa = (struct sigaction){
.sa_flags = 0,
.sa_handler = flag_signal,
};
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGALRM);
sigaddset(&sa.sa_mask, SIGCHLD);
sigaddset(&sa.sa_mask, SIGHUP);
sigaction(SIGALRM, &sa, &saalrm);
config();
sigaction(SIGHUP, &sa, &sahup);
sigaction(SIGCHLD, &sa, &sachld);
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 (pipe2(signalpipe, O_CLOEXEC) != 0) {
syslog(LOG_ERR, "pipe: %m");
exit(EX_OSERR);
}
FD_SET(signalpipe[0], &allsock);
#ifdef SANITY_CHECK
nsock++;
#endif
maxsock = MAX(MAX(maxsock, signalpipe[0]), signalpipe[1]);
for (;;) {
int n, ctrl;
fd_set readable;
#ifdef SANITY_CHECK
if (nsock == 0) {
syslog(LOG_ERR, "%s: nsock=0", __func__);
exit(EX_SOFTWARE);
}
#endif
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 nsig, signo;
if (ioctl(signalpipe[0], FIONREAD, &nsig) != 0) {
syslog(LOG_ERR, "ioctl: %m");
exit(EX_OSERR);
}
nsig /= sizeof(signo);
while (--nsig >= 0) {
size_t len;
len = read(signalpipe[0], &signo, sizeof(signo));
if (len != sizeof(signo)) {
syslog(LOG_ERR, "read: %m");
exit(EX_OSERR);
}
if (debug)
warnx("handling signal flag %d", signo);
switch (signo) {
case SIGALRM:
retry();
break;
case SIGCHLD:
reapchild();
break;
case SIGHUP:
config();
break;
}
}
}
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);
dofork = !sep->se_bi || sep->se_bi->bi_fork || ISWRAP(sep);
conn = NULL;
if (sep->se_accept && sep->se_socktype == SOCK_STREAM) {
i = 1;
if (ioctl(sep->se_fd, FIONBIO, &i) < 0)
syslog(LOG_ERR, "ioctl (FIONBIO, 1): %m");
ctrl = accept(sep->se_fd, (struct sockaddr *)0,
(socklen_t *)0);
if (debug)
warnx("accept, ctrl %d", ctrl);
if (ctrl < 0) {
if (errno != EINTR)
syslog(LOG_WARNING,
"accept (for %s): %m",
sep->se_service);
if (sep->se_accept &&
sep->se_socktype == SOCK_STREAM)
close(ctrl);
continue;
}
i = 0;
if (ioctl(sep->se_fd, FIONBIO, &i) < 0)
syslog(LOG_ERR, "ioctl1(FIONBIO, 0): %m");
if (ioctl(ctrl, FIONBIO, &i) < 0)
syslog(LOG_ERR, "ioctl2(FIONBIO, 0): %m");
if (cpmip(sep, ctrl) < 0) {
close(ctrl);
continue;
}
if (dofork &&
(conn = search_conn(sep, ctrl)) != NULL &&
!room_conn(sep, conn)) {
close(ctrl);
continue;
}
} else
ctrl = sep->se_fd;
if (dolog && !ISWRAP(sep)) {
char pname[NI_MAXHOST] = "unknown";
socklen_t sl;
sl = sizeof(peer);
if (getpeername(ctrl, (struct sockaddr *)
&peer, &sl)) {
sl = sizeof(peer);
if (recvfrom(ctrl, buf, sizeof(buf),
MSG_PEEK,
(struct sockaddr *)&peer,
&sl) >= 0) {
getnameinfo((struct sockaddr *)&peer,
peer.ss_len,
pname, sizeof(pname),
NULL, 0, NI_NUMERICHOST);
}
} else {
getnameinfo((struct sockaddr *)&peer,
peer.ss_len,
pname, sizeof(pname),
NULL, 0, NI_NUMERICHOST);
}
syslog(LOG_INFO,"%s from %s", sep->se_service, pname);
}
(void) sigblock(SIGBLOCK);
pid = 0;
/*
* Fork for all external services, builtins which need to
* fork and anything we're wrapping (as wrapping might
* block or use hosts_options(5) twist).
*/
if (dofork) {
if (sep->se_count++ == 0)
(void)clock_gettime(CLOCK_MONOTONIC_FAST, &sep->se_time);
else if (toomany > 0 && sep->se_count >= toomany) {
struct timespec now;
(void)clock_gettime(CLOCK_MONOTONIC_FAST, &now);
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);
if (sep->se_accept &&
sep->se_socktype == SOCK_STREAM)
close(ctrl);
close_sep(sep);
free_conn(conn);
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);
free_conn(conn);
sigsetmask(0L);
sleep(1);
continue;
}
if (pid) {
addchild_conn(conn, pid);
addchild(sep, pid);
}
sigsetmask(0L);
if (pid == 0) {
pidfile_close(pfh);
if (dofork) {
sigaction(SIGALRM, &saalrm, (struct sigaction *)0);
sigaction(SIGCHLD, &sachld, (struct sigaction *)0);
sigaction(SIGHUP, &sahup, (struct sigaction *)0);
/* SIGPIPE reset before exec */
}
/*
* Call tcpmux to find the real service to exec.
*/
if (sep->se_bi &&
sep->se_bi->bi_fn == (bi_fn_t *) tcpmux) {
sep = tcpmux(ctrl);
if (sep == NULL) {
close(ctrl);
_exit(0);
}
}
#ifdef LIBWRAP
if (ISWRAP(sep)) {
inetd_setproctitle("wrapping", ctrl);
service = sep->se_server_name ?
sep->se_server_name : sep->se_service;
request_init(&req, RQ_DAEMON, service, RQ_FILE, ctrl, 0);
fromhost(&req);
deny_severity = LIBWRAP_DENY_FACILITY|LIBWRAP_DENY_SEVERITY;
allow_severity = LIBWRAP_ALLOW_FACILITY|LIBWRAP_ALLOW_SEVERITY;
denied = !hosts_access(&req);
if (denied) {
syslog(deny_severity,
"refused connection from %.500s, service %s (%s%s)",
eval_client(&req), service, sep->se_proto,
(whichaf(&req) == AF_INET6) ? "6" : "");
if (sep->se_socktype != SOCK_STREAM)
recv(ctrl, buf, sizeof (buf), 0);
if (dofork) {
sleep(1);
_exit(0);
}
}
if (dolog) {
syslog(allow_severity,
"connection from %.500s, service %s (%s%s)",
eval_client(&req), service, sep->se_proto,
(whichaf(&req) == AF_INET6) ? "6" : "");
}
}
#endif
if (sep->se_bi) {
(*sep->se_bi->bi_fn)(ctrl, sep);
} else {
if (debug)
warnx("%d execl %s",
getpid(), sep->se_server);
/* Clear close-on-exec. */
if (fcntl(ctrl, F_SETFD, 0) < 0) {
syslog(LOG_ERR,
"%s/%s: fcntl (F_SETFD, 0): %m",
sep->se_service, sep->se_proto);
_exit(EX_OSERR);
}
if (ctrl != 0) {
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,
sep->se_class);
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 & ~LOGIN_SETMAC)
!= 0) {
syslog(LOG_ERR,
"%s: can't setusercontext(..%s..): %m",
sep->se_service, sep->se_user);
_exit(EX_OSERR);
}
login_close(lc);
#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);
syslog(LOG_ERR,
"cannot execute %s: %m", sep->se_server);
if (sep->se_socktype != SOCK_STREAM)
recv(0, buf, sizeof (buf), 0);
}
if (dofork)
_exit(0);
}
if (sep->se_accept && sep->se_socktype == SOCK_STREAM)
close(ctrl);
}
}
}
/*
* Add a signal flag to the signal flag queue for later handling
*/
static void
flag_signal(int signo)
{
size_t len;
len = write(signalpipe[1], &signo, sizeof(signo));
if (len != sizeof(signo)) {
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.
*/
static void
addchild(struct servtab *sep, pid_t pid)
{
struct stabchild *sc;
#ifdef SANITY_CHECK
if (SERVTAB_EXCEEDS_LIMIT(sep)) {
syslog(LOG_ERR, "%s: %d >= %d",
__func__, sep->se_numchild, sep->se_maxchild);
exit(EX_SOFTWARE);
}
#endif
sc = calloc(1, sizeof(*sc));
if (sc == NULL) {
syslog(LOG_ERR, "calloc: %m");
exit(EX_OSERR);
}
sc->sc_pid = pid;
LIST_INSERT_HEAD(&sep->se_children, sc, sc_link);
++sep->se_numchild;
if (SERVTAB_AT_LIMIT(sep))
disable(sep);
}
static void
reapchild(void)
{
int status;
pid_t pid;
struct stabchild *sc;
struct servtab *sep;
for (;;) {
pid = wait3(&status, WNOHANG, (struct rusage *)0);
if (pid <= 0)
break;
if (debug)
warnx("%d reaped, %s %u", pid,
WIFEXITED(status) ? "status" : "signal",
WIFEXITED(status) ? WEXITSTATUS(status)
: WTERMSIG(status));
for (sep = servtab; sep; sep = sep->se_next) {
LIST_FOREACH(sc, &sep->se_children, sc_link) {
if (sc->sc_pid == pid)
break;
}
if (sc == NULL)
continue;
if (SERVTAB_AT_LIMIT(sep))
enable(sep);
LIST_REMOVE(sc, sc_link);
free(sc);
--sep->se_numchild;
if (WIFSIGNALED(status) || WEXITSTATUS(status))
syslog(LOG_WARNING,
"%s[%d]: exited, %s %u",
sep->se_server, pid,
WIFEXITED(status) ? "status" : "signal",
WIFEXITED(status) ? WEXITSTATUS(status)
: WTERMSIG(status));
break;
}
reapchild_conn(pid);
}
}
static void
config(void)
{
struct servtab *sep, *new, **sepp;
long omask;
int new_nomapped;
#ifdef LOGIN_CAP
login_cap_t *lc = NULL;
#endif
if (!setconfig()) {
syslog(LOG_ERR, "%s: %m", CONFIG);
return;
}
for (sep = servtab; sep; sep = sep->se_next)
sep->se_checked = 0;
while ((new = getconfigent())) {