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-rw-r--r--networking/inetd.c1280
1 files changed, 1280 insertions, 0 deletions
diff --git a/networking/inetd.c b/networking/inetd.c
new file mode 100644
index 0000000..047358c
--- /dev/null
+++ b/networking/inetd.c
@@ -0,0 +1,1280 @@
+/*
+ * Copyright (c) 1983,1991 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * David A. Holland.
+ *
+ * Busybox port by Vladimir Oleynik (C) 2001-2003 <dzo@simtreas.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+/*
+ * Inetd - Internet super-server
+ *
+ * This program invokes all internet services as needed.
+ * connection-oriented services are invoked each time a
+ * connection is made, by creating a process. This process
+ * is passed the connection as file descriptor 0 and is
+ * expected to do a getpeername to find out the source host
+ * and port.
+ *
+ * Datagram oriented services are invoked when a datagram
+ * arrives; a process is created and passed a pending message
+ * on file descriptor 0. Datagram servers may either connect
+ * to their peer, freeing up the original socket for inetd
+ * to receive further messages on, or ``take over the socket'',
+ * processing all arriving datagrams and, eventually, timing
+ * out. The first type of server is said to be ``multi-threaded'';
+ * the second type of server ``single-threaded''.
+ *
+ * Inetd uses a configuration file which is read at startup
+ * and, possibly, at some later time in response to a hangup signal.
+ * The configuration file is ``free format'' with fields given in the
+ * order shown below. Continuation lines for an entry must being with
+ * a space or tab. All fields must be present in each entry.
+ *
+ * service name must be in /etc/services
+ * socket type stream/dgram/raw/rdm/seqpacket
+ * protocol must be in /etc/protocols
+ * wait/nowait[.max] single-threaded/multi-threaded, max #
+ * user[.group] user/group to run daemon as
+ * server program full path name
+ * server program arguments maximum of MAXARGS (20)
+ *
+ * RPC services unsuported
+ *
+ * Comment lines are indicated by a `#' in column 1.
+ */
+
+/*
+ * Here's the scoop concerning the user.group feature:
+ *
+ * 1) No group listed.
+ *
+ * a) for root: NO setuid() or setgid() is done
+ *
+ * b) nonroot: setuid()
+ * setgid(primary group as found in passwd)
+ * initgroups(name, primary group)
+ *
+ * 2) set-group-option on.
+ *
+ * a) for root: NO setuid()
+ * setgid(specified group)
+ * setgroups(1, specified group)
+ *
+ * b) nonroot: setuid()
+ * setgid(specified group)
+ * initgroups(name, specified group)
+ *
+ * All supplementary groups are discarded at startup in case inetd was
+ * run manually.
+ */
+
+#define __USE_BSD_SIGNAL
+
+#include "busybox.h"
+
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/file.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#ifndef __linux__
+#ifndef RLIMIT_NOFILE
+#define RLIMIT_NOFILE RLIMIT_OFILE
+#endif
+#endif
+
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/file.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <arpa/inet.h>
+
+#include <errno.h>
+#include <signal.h>
+#include <netdb.h>
+#include <syslog.h>
+#include <pwd.h>
+#include <grp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <unistd.h>
+#include <stdarg.h>
+
+#define _PATH_INETDCONF "/etc/inetd.conf"
+#define _PATH_INETDPID "/var/run/inetd.pid"
+
+#ifndef MIN
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+#define TOOMANY 40 /* don't start more than TOOMANY */
+#define CNT_INTVL 60 /* servers in CNT_INTVL sec. */
+#define RETRYTIME (60*10) /* retry after bind or server fail */
+
+#ifndef OPEN_MAX
+#define OPEN_MAX 64
+#endif
+
+
+/* Reserve some descriptors, 3 stdio + at least: 1 log, 1 conf. file */
+#define FD_MARGIN (8)
+static int rlim_ofile_cur = OPEN_MAX;
+
+#ifdef RLIMIT_NOFILE
+static struct rlimit rlim_ofile;
+#endif
+
+
+static struct servtab {
+ char *se_service; /* name of service */
+ int se_socktype; /* type of socket to use */
+ int se_family; /* address family */
+ char *se_proto; /* protocol used */
+ short se_wait; /* single threaded server */
+ short se_checked; /* looked at during merge */
+ char *se_user; /* user name to run as */
+ char *se_group; /* group name to run as */
+#ifndef INETD_UNSUPPORT_BILTIN
+ const struct biltin *se_bi; /* if built-in, description */
+#endif
+ 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_un se_un_ctrladdr_un;
+ } 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_un se_un.se_un_ctrladdr_un
+ 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;
+} *servtab;
+
+/* Length of socket listen queue. Should be per-service probably. */
+static int global_queuelen = 128;
+
+static int nsock, maxsock;
+static fd_set allsock;
+static int timingout;
+static sigset_t blockmask, emptymask;
+
+
+#define INETD_UNSUPPORT_BILTIN 1
+
+ /* Echo received data */
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_ECHO
+#undef INETD_UNSUPPORT_BILTIN
+static void echo_stream(int, struct servtab *);
+static void echo_dg(int, struct servtab *);
+#endif
+ /* Internet /dev/null */
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DISCARD
+#undef INETD_UNSUPPORT_BILTIN
+static void discard_stream(int, struct servtab *);
+static void discard_dg(int, struct servtab *);
+#endif
+ /* Return 32 bit time since 1900 */
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_TIME
+#undef INETD_UNSUPPORT_BILTIN
+static void machtime_stream(int, struct servtab *);
+static void machtime_dg(int, struct servtab *);
+#endif
+ /* Return human-readable time */
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DAYTIME
+#undef INETD_UNSUPPORT_BILTIN
+static void daytime_stream(int, struct servtab *);
+static void daytime_dg(int, struct servtab *);
+#endif
+ /* Familiar character generator */
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_CHARGEN
+#undef INETD_UNSUPPORT_BILTIN
+static void chargen_stream(int, struct servtab *);
+static void chargen_dg(int, struct servtab *);
+#endif
+
+#ifndef INETD_UNSUPPORT_BILTIN
+struct biltin {
+ const 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 *); /* fn which performs it */
+};
+
+static const struct biltin biltins[] = {
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_ECHO
+ /* Echo received data */
+ { "echo", SOCK_STREAM, 1, 0, echo_stream, },
+ { "echo", SOCK_DGRAM, 0, 0, echo_dg, },
+#endif
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DISCARD
+ /* Internet /dev/null */
+ { "discard", SOCK_STREAM, 1, 0, discard_stream, },
+ { "discard", SOCK_DGRAM, 0, 0, discard_dg, },
+#endif
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_TIME
+ /* Return 32 bit time since 1900 */
+ { "time", SOCK_STREAM, 0, 0, machtime_stream, },
+ { "time", SOCK_DGRAM, 0, 0, machtime_dg, },
+#endif
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DAYTIME
+ /* Return human-readable time */
+ { "daytime", SOCK_STREAM, 0, 0, daytime_stream, },
+ { "daytime", SOCK_DGRAM, 0, 0, daytime_dg, },
+#endif
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_CHARGEN
+ /* Familiar character generator */
+ { "chargen", SOCK_STREAM, 1, 0, chargen_stream, },
+ { "chargen", SOCK_DGRAM, 0, 0, chargen_dg, },
+#endif
+ { NULL, 0, 0, 0, NULL }
+};
+#endif /* INETD_UNSUPPORT_BILTIN */
+
+#define NUMINT (sizeof(intab) / sizeof(struct inent))
+static const char *CONFIG = _PATH_INETDCONF;
+
+#define BCOPY(s, d, z) memcpy(d, s, z)
+
+static void
+syslog_err_and_discard_dg(int se_socktype, const char *msg, ...)
+ __attribute__ ((noreturn, format (printf, 2, 3)));
+
+static void
+syslog_err_and_discard_dg(int se_socktype, const char *msg, ...)
+{
+ char buf[50];
+ va_list p;
+
+ va_start(p, msg);
+ vsyslog(LOG_ERR, msg, p);
+ if (se_socktype != SOCK_STREAM)
+ recv(0, buf, sizeof (buf), 0);
+ _exit(1);
+}
+
+static FILE *fconfig;
+static char line[256];
+
+static FILE *
+setconfig(void)
+{
+ FILE *f = fconfig;
+
+ if (f != NULL) {
+ fseek(f, 0L, L_SET);
+ } else {
+ f = fconfig = fopen(CONFIG, "r");
+ if(f == NULL)
+ syslog(LOG_ERR, "%s: %m", CONFIG);
+ }
+ return f;
+}
+
+static char *
+nextline(void)
+{
+ char *cp;
+ FILE *fd = fconfig;
+
+ if (fgets(line, sizeof (line), fd) == NULL)
+ return ((char *)0);
+ cp = strchr(line, '\n');
+ if (cp)
+ *cp = '\0';
+ return (line);
+}
+
+static char *
+skip(char **cpp)
+{
+ char *cp = *cpp;
+ char *start;
+
+ if (*cpp == NULL)
+ return ((char *)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()) != NULL)
+ goto again;
+ *cpp = NULL;
+ return NULL;
+ }
+ start = cp;
+ while (*cp && *cp != ' ' && *cp != '\t')
+ cp++;
+ if (*cp != '\0')
+ *cp++ = '\0';
+ *cpp = cp;
+ return (start);
+}
+
+static char *
+newstr(char *cp)
+{
+ cp = strdup(cp ? cp : "");
+ if (cp)
+ return(cp);
+
+ syslog_err_and_discard_dg(SOCK_STREAM, "strdup: %m");
+}
+
+
+static struct servtab *
+getconfigent(void)
+{
+ static struct servtab serv;
+ struct servtab *sep = &serv;
+ int argc;
+ char *cp, *arg;
+
+more:
+ while ((cp = nextline()) && *cp == '#')
+ ;
+ if (cp == NULL)
+ return ((struct servtab *)0);
+ memset((char *)sep, 0, sizeof *sep);
+ sep->se_service = newstr(skip(&cp));
+ arg = skip(&cp);
+ if (arg == 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 if (strcmp(arg, "rdm") == 0)
+ sep->se_socktype = SOCK_RDM;
+ else if (strcmp(arg, "seqpacket") == 0)
+ sep->se_socktype = SOCK_SEQPACKET;
+ else if (strcmp(arg, "raw") == 0)
+ sep->se_socktype = SOCK_RAW;
+ else
+ sep->se_socktype = -1;
+
+ sep->se_proto = newstr(skip(&cp));
+ if (strcmp(sep->se_proto, "unix") == 0) {
+ sep->se_family = AF_UNIX;
+ } else {
+ sep->se_family = AF_INET;
+ if (strncmp(sep->se_proto, "rpc/", 4) == 0) {
+ syslog(LOG_ERR, "%s: rpc services not suported",
+ sep->se_service);
+ goto more;
+ }
+ }
+ arg = skip(&cp);
+ if (arg == NULL)
+ goto more;
+ {
+ char *s = strchr(arg, '.');
+ if (s) {
+ *s++ = '\0';
+ sep->se_max = atoi(s);
+ } else
+ sep->se_max = TOOMANY;
+ }
+ sep->se_wait = strcmp(arg, "wait") == 0;
+ sep->se_user = newstr(skip(&cp));
+ sep->se_group = strchr(sep->se_user, '.');
+ if (sep->se_group) {
+ *sep->se_group++ = '\0';
+ }
+ sep->se_server = newstr(skip(&cp));
+ if (strcmp(sep->se_server, "internal") == 0) {
+#ifndef INETD_UNSUPPORT_BILTIN
+ const 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
+ syslog(LOG_ERR, "internal service %s unknown",
+ sep->se_service);
+ goto more;
+#endif
+ } else
+#ifndef INETD_UNSUPPORT_BILTIN
+ sep->se_bi = NULL
+#endif
+ ;
+ argc = 0;
+ for (arg = skip(&cp); cp; arg = skip(&cp)) {
+ if (argc < MAXARGV)
+ sep->se_argv[argc++] = newstr(arg);
+ }
+ while (argc <= MAXARGV)
+ sep->se_argv[argc++] = NULL;
+ return (sep);
+}
+
+static void
+freeconfig(struct servtab *cp)
+{
+ int i;
+
+ free(cp->se_service);
+ free(cp->se_proto);
+ free(cp->se_user);
+ /* Note: se_group is part of the newstr'ed se_user */
+ free(cp->se_server);
+ for (i = 0; i < MAXARGV; i++)
+ free(cp->se_argv[i]);
+}
+
+#ifndef INETD_UNSUPPORT_BILTIN
+static char **Argv;
+static char *LastArg;
+
+static void
+setproctitle(char *a, int s)
+{
+ size_t size;
+ char *cp;
+ struct sockaddr_in sn;
+ char buf[80];
+
+ cp = Argv[0];
+ size = sizeof(sn);
+ if (getpeername(s, (struct sockaddr *)&sn, &size) == 0)
+ (void) sprintf(buf, "-%s [%s]", a, inet_ntoa(sn.sin_addr));
+ else
+ (void) sprintf(buf, "-%s", a);
+ strncpy(cp, buf, LastArg - cp);
+ cp += strlen(cp);
+ while (cp < LastArg)
+ *cp++ = ' ';
+}
+#endif /* INETD_UNSUPPORT_BILTIN */
+
+static struct servtab *
+enter(struct servtab *cp)
+{
+ struct servtab *sep;
+ sigset_t oldmask;
+
+ sep = (struct servtab *)malloc(sizeof (*sep));
+ if (sep == NULL) {
+ syslog_err_and_discard_dg(SOCK_STREAM, memory_exhausted);
+ }
+ *sep = *cp;
+ sep->se_fd = -1;
+ sigprocmask(SIG_BLOCK, &blockmask, &oldmask);
+ sep->se_next = servtab;
+ servtab = sep;
+ sigprocmask(SIG_SETMASK, &oldmask, NULL);
+ return (sep);
+}
+
+static int
+bump_nofile(void)
+{
+#ifdef RLIMIT_NOFILE
+
+#define FD_CHUNK 32
+
+ struct rlimit rl;
+
+ if (getrlimit(RLIMIT_NOFILE, &rl) < 0) {
+ syslog(LOG_ERR, "getrlimit: %m");
+ return -1;
+ }
+ rl.rlim_cur = MIN(rl.rlim_max, rl.rlim_cur + FD_CHUNK);
+ if (rl.rlim_cur <= rlim_ofile_cur) {
+ syslog(LOG_ERR,
+ "bump_nofile: cannot extend file limit, max = %d",
+ rl.rlim_cur);
+ return -1;
+ }
+
+ if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
+ syslog(LOG_ERR, "setrlimit: %m");
+ return -1;
+ }
+
+ rlim_ofile_cur = rl.rlim_cur;
+ return 0;
+
+#else
+ syslog(LOG_ERR, "bump_nofile: cannot extend file limit");
+ return -1;
+#endif
+}
+
+
+static void
+setup(struct servtab *sep)
+{
+ int on = 1;
+
+ if ((sep->se_fd = socket(sep->se_family, sep->se_socktype, 0)) < 0) {
+ syslog(LOG_ERR, "%s/%s: socket: %m",
+ sep->se_service, sep->se_proto);
+ return;
+ }
+ if (setsockopt(sep->se_fd, SOL_SOCKET, SO_REUSEADDR, (void *)&on,
+ sizeof(on)) < 0)
+ syslog(LOG_ERR, "setsockopt (SO_REUSEADDR): %m");
+ if (bind(sep->se_fd, &sep->se_ctrladdr, sep->se_ctrladdr_size) < 0) {
+ syslog(LOG_ERR, "%s/%s: bind: %m",
+ sep->se_service, sep->se_proto);
+ (void) close(sep->se_fd);
+ sep->se_fd = -1;
+ if (!timingout) {
+ timingout = 1;
+ alarm(RETRYTIME);
+ }
+ return;
+ }
+ if (sep->se_socktype == SOCK_STREAM)
+ listen(sep->se_fd, global_queuelen);
+
+ FD_SET(sep->se_fd, &allsock);
+ nsock++;
+ if (sep->se_fd > maxsock) {
+ maxsock = sep->se_fd;
+ if (maxsock > rlim_ofile_cur - FD_MARGIN)
+ bump_nofile();
+ }
+}
+
+static void
+config(int signum)
+{
+ struct servtab *sep, *cp, **sepp;
+ sigset_t oldmask;
+ unsigned n;
+
+ (void)signum;
+ if (setconfig() == NULL)
+ return;
+
+ for (sep = servtab; sep; sep = sep->se_next)
+ sep->se_checked = 0;
+ while ((cp = getconfigent()) != NULL) {
+ for (sep = servtab; sep; sep = sep->se_next)
+ if (strcmp(sep->se_service, cp->se_service) == 0 &&
+ strcmp(sep->se_proto, cp->se_proto) == 0)
+ break;
+ if (sep != 0) {
+ int i;
+
+#define SWAP(type, a, b) {type c=(type)a; (type)a=(type)b; (type)b=(type)c;}
+
+ sigprocmask(SIG_BLOCK, &emptymask, &oldmask);
+ /*
+ * 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 (
+#ifndef INETD_UNSUPPORT_BILTIN
+ cp->se_bi == 0 &&
+#endif
+ (sep->se_wait == 1 || cp->se_wait == 0))
+ sep->se_wait = cp->se_wait;
+ if (cp->se_max != sep->se_max)
+ SWAP(int, cp->se_max, sep->se_max);
+ if (cp->se_user)
+ SWAP(char *, sep->se_user, cp->se_user);
+ if (cp->se_group)
+ SWAP(char *, sep->se_group, cp->se_group);
+ if (cp->se_server)
+ 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
+ sigprocmask(SIG_SETMASK, &oldmask, NULL);
+ freeconfig(cp);
+ } else {
+ sep = enter(cp);
+ }
+ sep->se_checked = 1;
+
+ switch (sep->se_family) {
+ case AF_UNIX:
+ if (sep->se_fd != -1)
+ break;
+ (void)unlink(sep->se_service);
+ n = strlen(sep->se_service);
+ if (n > sizeof(sep->se_ctrladdr_un.sun_path) - 1)
+ n = sizeof(sep->se_ctrladdr_un.sun_path) - 1;
+ strncpy(sep->se_ctrladdr_un.sun_path, sep->se_service, n);
+ sep->se_ctrladdr_un.sun_family = AF_UNIX;
+ sep->se_ctrladdr_size = n +
+ sizeof sep->se_ctrladdr_un.sun_family;
+ setup(sep);
+ break;
+ case AF_INET:
+ sep->se_ctrladdr_in.sin_family = AF_INET;
+ sep->se_ctrladdr_size = sizeof sep->se_ctrladdr_in;
+ {
+ u_short port = htons(atoi(sep->se_service));
+
+ if (!port) {
+ struct servent *sp;
+ sp = getservbyname(sep->se_service,
+ sep->se_proto);
+ if (sp == 0) {
+ syslog(LOG_ERR,
+ "%s/%s: unknown service",
+ sep->se_service, sep->se_proto);
+ continue;
+ }
+ port = sp->s_port;
+ }
+ if (port != sep->se_ctrladdr_in.sin_port) {
+ sep->se_ctrladdr_in.sin_port = port;
+ if (sep->se_fd != -1) {
+ FD_CLR(sep->se_fd, &allsock);
+ nsock--;
+ (void) close(sep->se_fd);
+ }
+ sep->se_fd = -1;
+ }
+ if (sep->se_fd == -1)
+ setup(sep);
+ }
+ }
+ }
+ if (fconfig) {
+ (void) fclose(fconfig);
+ fconfig = NULL;
+ }
+ /*
+ * Purge anything not looked at above.
+ */
+ sigprocmask(SIG_SETMASK, &blockmask, &oldmask);
+ sepp = &servtab;
+ while ((sep = *sepp) != NULL) {
+ if (sep->se_checked) {
+ sepp = &sep->se_next;
+ continue;
+ }
+ *sepp = sep->se_next;
+ if (sep->se_fd != -1) {
+ FD_CLR(sep->se_fd, &allsock);
+ nsock--;
+ (void) close(sep->se_fd);
+ }
+ if (sep->se_family == AF_UNIX)
+ (void)unlink(sep->se_service);
+ freeconfig(sep);
+ free((char *)sep);
+ }
+ sigprocmask(SIG_SETMASK, &oldmask, NULL);
+}
+
+
+
+static void
+reapchild(int signum)
+{
+ int status;
+ int pid;
+ struct servtab *sep;
+
+ (void)signum;
+ for (;;) {
+ pid = wait3(&status, WNOHANG, (struct rusage *)0);
+ if (pid <= 0)
+ break;
+ for (sep = servtab; sep; sep = sep->se_next)
+ if (sep->se_wait == pid) {
+ if (WIFEXITED(status) && WEXITSTATUS(status))
+ syslog(LOG_WARNING,
+ "%s: exit status 0x%x",
+ sep->se_server, WEXITSTATUS(status));
+ else if (WIFSIGNALED(status))
+ syslog(LOG_WARNING,
+ "%s: exit signal 0x%x",
+ sep->se_server, WTERMSIG(status));
+ sep->se_wait = 1;
+ FD_SET(sep->se_fd, &allsock);
+ nsock++;
+ }
+ }
+}
+
+static void
+retry(int signum)
+{
+ struct servtab *sep;
+
+ (void)signum;
+ 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:
+ setup(sep);
+ break;
+ }
+ }
+ }
+}
+
+static void
+goaway(int signum)
+{
+ struct servtab *sep;
+
+ (void)signum;
+ for (sep = servtab; sep; sep = sep->se_next)
+ if (sep->se_fd != -1 && sep->se_family == AF_UNIX)
+ (void)unlink(sep->se_service);
+ (void)unlink(_PATH_INETDPID);
+ exit(0);
+}
+
+
+
+extern int
+inetd_main(int argc, char *argv[])
+{
+ struct servtab *sep;
+ struct passwd *pwd;
+ struct group *grp = NULL;
+ struct sigaction sa;
+ int ch, pid;
+ gid_t gid;
+
+#ifdef INETD_UNSUPPORT_BILTIN
+# define dofork 1
+#else
+ int dofork;
+ extern char **environ;
+#endif
+
+ gid = getgid();
+ setgroups(1, &gid);
+
+#ifndef INETD_UNSUPPORT_BILTIN
+ Argv = argv;
+ if (environ == 0 || *environ == 0)
+ environ = argv;
+ while (*environ)
+ environ++;
+ LastArg = environ[-1] + strlen(environ[-1]);
+#endif
+
+ while ((ch = getopt(argc, argv, "q:")) != EOF)
+ switch(ch) {
+ case 'q':
+ global_queuelen = atoi(optarg);
+ if (global_queuelen < 8) global_queuelen=8;
+ break;
+ default:
+ show_usage(); // "[-q len] [conf]"
+ }
+ argc -= optind;
+ argv += optind;
+
+ if (argc > 0)
+ CONFIG = argv[0];
+
+ daemon(0, 0);
+ openlog(applet_name, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
+ {
+ FILE *fp;
+
+ if ((fp = fopen(_PATH_INETDPID, "w")) != NULL) {
+ fprintf(fp, "%u\n", getpid());
+ (void)fclose(fp);
+ }
+ }
+
+#ifdef RLIMIT_NOFILE
+ if (getrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0) {
+ syslog(LOG_ERR, "getrlimit: %m");
+ } else {
+ rlim_ofile_cur = rlim_ofile.rlim_cur;
+ if (rlim_ofile_cur == RLIM_INFINITY) /* ! */
+ rlim_ofile_cur = OPEN_MAX;
+ }
+#endif
+
+ config(0);
+
+ sigemptyset(&emptymask);
+ sigemptyset(&blockmask);
+ sigaddset(&blockmask, SIGCHLD);
+ sigaddset(&blockmask, SIGHUP);
+ sigaddset(&blockmask, SIGALRM);
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_mask = blockmask;
+ sa.sa_handler = retry;
+ sigaction(SIGALRM, &sa, NULL);
+ sa.sa_handler = config;
+ sigaction(SIGHUP, &sa, NULL);
+ sa.sa_handler = reapchild;
+ sigaction(SIGCHLD, &sa, NULL);
+ sa.sa_handler = goaway;
+ sigaction(SIGTERM, &sa, NULL);
+ sa.sa_handler = goaway;
+ sigaction(SIGINT, &sa, NULL);
+ sa.sa_handler = SIG_IGN;
+ sigaction(SIGPIPE, &sa, NULL);
+
+ {
+ /* 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);
+ }
+
+ for (;;) {
+ int n, ctrl;
+ fd_set readable;
+
+ if (nsock == 0) {
+ sigprocmask(SIG_BLOCK, &blockmask, NULL);
+ while (nsock == 0)
+ sigsuspend(&emptymask);
+ sigprocmask(SIG_SETMASK, &emptymask, NULL);
+ }
+ readable = allsock;
+ if ((n = select(maxsock + 1, &readable, (fd_set *)0,
+ (fd_set *)0, (struct timeval *)0)) <= 0) {
+ if (n < 0 && errno != EINTR)
+ syslog(LOG_WARNING, "select: %m");
+ sleep(1);
+ continue;
+ }
+ for (sep = servtab; n && sep; sep = sep->se_next)
+ if (sep->se_fd != -1 && FD_ISSET(sep->se_fd, &readable)) {
+ n--;
+ if (!sep->se_wait && sep->se_socktype == SOCK_STREAM) {
+ /* Fixed AGC */
+ fcntl(sep->se_fd, F_SETFL, O_NDELAY);
+ /* --------- */
+ ctrl = accept(sep->se_fd, NULL, NULL);
+ fcntl(sep->se_fd, F_SETFL, 0);
+ if (ctrl < 0) {
+ if (errno == EINTR || errno == EWOULDBLOCK)
+ continue;
+ syslog(LOG_WARNING, "accept (for %s): %m",
+ sep->se_service);
+ continue;
+ }
+ } else
+ ctrl = sep->se_fd;
+ sigprocmask(SIG_BLOCK, &blockmask, NULL);
+ pid = 0;
+#ifndef INETD_UNSUPPORT_BILTIN
+ dofork = (sep->se_bi == 0 || sep->se_bi->bi_fork);
+#endif
+ if (dofork) {
+ if (sep->se_count++ == 0)
+ (void)gettimeofday(&sep->se_time,
+ (struct timezone *)0);
+ else if (sep->se_count >= sep->se_max) {
+ 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);
+ FD_CLR(sep->se_fd, &allsock);
+ (void) close(sep->se_fd);
+ sep->se_fd = -1;
+ sep->se_count = 0;
+ nsock--;
+ sigprocmask(SIG_SETMASK, &emptymask,
+ NULL);
+ if (!timingout) {
+ timingout = 1;
+ alarm(RETRYTIME);
+ }
+ continue;
+ }
+ }
+ pid = fork();
+ }
+ if (pid < 0) {
+ syslog(LOG_ERR, "fork: %m");
+ if (sep->se_socktype == SOCK_STREAM)
+ close(ctrl);
+ sigprocmask(SIG_SETMASK, &emptymask, NULL);
+ sleep(1);
+ continue;
+ }
+ if (pid && sep->se_wait) {
+ sep->se_wait = pid;
+ FD_CLR(sep->se_fd, &allsock);
+ nsock--;
+ }
+ sigprocmask(SIG_SETMASK, &emptymask, NULL);
+ if (pid == 0) {
+#ifndef INETD_UNSUPPORT_BILTIN
+ if (sep->se_bi)
+ (*sep->se_bi->bi_fn)(ctrl, sep);
+ else
+#endif
+ {
+ if ((pwd = getpwnam(sep->se_user)) == NULL) {
+ syslog_err_and_discard_dg(
+ sep->se_socktype,
+ "getpwnam: %s: No such user",
+ sep->se_user);
+ }
+ if (sep->se_group &&
+ (grp = getgrnam(sep->se_group)) == NULL) {
+ syslog_err_and_discard_dg(
+ sep->se_socktype,
+ "getgrnam: %s: No such group",
+ sep->se_group);
+ }
+ /*
+ * Ok. There are four cases here:
+ * 1. nonroot user, no group specified
+ * 2. nonroot user, some group specified
+ * 3. root user, no group specified
+ * 4. root user, some group specified
+ * In cases 2 and 4 we setgid to the specified
+ * group. In cases 1 and 2 we run initgroups
+ * to run with the groups of the given user.
+ * In case 4 we do setgroups to run with the
+ * given group. In case 3 we do nothing.
+ */
+ if (pwd->pw_uid) {
+ if (sep->se_group)
+ pwd->pw_gid = grp->gr_gid;
+ setgid((gid_t)pwd->pw_gid);
+ initgroups(pwd->pw_name, pwd->pw_gid);
+ setuid((uid_t)pwd->pw_uid);
+ } else if (sep->se_group) {
+ setgid((gid_t)grp->gr_gid);
+ setgroups(1, &grp->gr_gid);
+ }
+ dup2(ctrl, 0);
+ close(ctrl);
+ dup2(0, 1);
+ dup2(0, 2);
+#ifdef RLIMIT_NOFILE
+ if (rlim_ofile.rlim_cur != rlim_ofile_cur) {
+ if (setrlimit(RLIMIT_NOFILE,
+ &rlim_ofile) < 0)
+ syslog(LOG_ERR,"setrlimit: %m");
+ }
+#endif
+ for (ctrl = rlim_ofile_cur-1; --ctrl > 2; )
+ (void)close(ctrl);
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = SIG_DFL;
+ sigaction(SIGPIPE, &sa, NULL);
+
+ execv(sep->se_server, sep->se_argv);
+ syslog_err_and_discard_dg(sep->se_socktype,
+ "execv %s: %m", sep->se_server);
+ }
+ }
+ if (!sep->se_wait && sep->se_socktype == SOCK_STREAM)
+ close(ctrl);
+ }
+ }
+}
+
+
+/*
+ * Internet services provided internally by inetd:
+ */
+#define BUFSIZE 4096
+
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_ECHO
+/* Echo service -- echo data back */
+static void
+echo_stream(int s, struct servtab *sep)
+{
+ char buffer[BUFSIZE];
+ int i;
+
+ setproctitle(sep->se_service, s);
+ while ((i = read(s, buffer, sizeof(buffer))) > 0 &&
+ write(s, buffer, i) > 0)
+ ;
+ exit(0);
+}
+
+/* Echo service -- echo data back */
+static void
+echo_dg(int s, struct servtab *sep)
+{
+ char buffer[BUFSIZE];
+ int i;
+ size_t size;
+ struct sockaddr sa;
+
+ (void)sep;
+
+ size = sizeof(sa);
+ if ((i = recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size)) < 0)
+ return;
+ (void) sendto(s, buffer, i, 0, &sa, sizeof(sa));
+}
+#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_ECHO */
+
+
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DISCARD
+/* Discard service -- ignore data */
+static void
+discard_stream(int s, struct servtab *sep)
+{
+ char buffer[BUFSIZE];
+
+ setproctitle(sep->se_service, s);
+ while ((errno = 0, read(s, buffer, sizeof(buffer)) > 0) ||
+ errno == EINTR)
+ ;
+ exit(0);
+}
+
+/* Discard service -- ignore data */
+static void
+discard_dg(int s, struct servtab *sep)
+{
+ char buffer[BUFSIZE];
+ (void)sep;
+ read(s, buffer, sizeof(buffer));
+}
+#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DISCARD */
+
+
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_CHARGEN
+#include <ctype.h>
+#define LINESIZ 72
+static char ring[128];
+static char *endring;
+
+static void
+initring(void)
+{
+ int i;
+
+ endring = ring;
+
+ for (i = 0; i <= 128; ++i)
+ if (isprint(i))
+ *endring++ = i;
+}
+
+/* Character generator */
+static void
+chargen_stream(int s, struct servtab *sep)
+{
+ char *rs;
+ int len;
+ char text[LINESIZ+2];
+
+ setproctitle(sep->se_service, s);
+
+ if (!endring) {
+ initring();
+ rs = ring;
+ }
+
+ text[LINESIZ] = '\r';
+ text[LINESIZ + 1] = '\n';
+ for (rs = ring;;) {
+ if ((len = endring - rs) >= LINESIZ)
+ BCOPY(rs, text, LINESIZ);
+ else {
+ BCOPY(rs, text, len);
+ BCOPY(ring, text + len, LINESIZ - len);
+ }
+ if (++rs == endring)
+ rs = ring;
+ if (write(s, text, sizeof(text)) != sizeof(text))
+ break;
+ }
+ exit(0);
+}
+
+/* Character generator */
+static void
+chargen_dg(int s, struct servtab *sep)
+{
+ struct sockaddr sa;
+ static char *rs;
+ size_t len, size;
+ char text[LINESIZ+2];
+
+ (void)sep;
+
+ if (endring == 0) {
+ initring();
+ rs = ring;
+ }
+
+ size = sizeof(sa);
+ if (recvfrom(s, text, sizeof(text), 0, &sa, &size) < 0)
+ return;
+
+ if ((len = endring - rs) >= LINESIZ)
+ BCOPY(rs, text, LINESIZ);
+ else {
+ BCOPY(rs, text, len);
+ BCOPY(ring, text + len, LINESIZ - len);
+ }
+ if (++rs == endring)
+ rs = ring;
+ text[LINESIZ] = '\r';
+ text[LINESIZ + 1] = '\n';
+ (void) sendto(s, text, sizeof(text), 0, &sa, sizeof(sa));
+}
+#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_CHARGEN */
+
+
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_TIME
+/*
+ * 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.
+ */
+
+static long
+machtime(void)
+{
+ struct timeval tv;
+
+ if (gettimeofday(&tv, (struct timezone *)0) < 0) {
+ fprintf(stderr, "Unable to get time of day\n");
+ return (0L);
+ }
+ return (htonl((long)tv.tv_sec + 2208988800UL));
+}
+
+static void
+machtime_stream(int s, struct servtab *sep)
+{
+ long result;
+ (void)sep;
+
+ result = machtime();
+ write(s, (char *) &result, sizeof(result));
+}
+
+static void
+machtime_dg(int s, struct servtab *sep)
+{
+ long result;
+ struct sockaddr sa;
+ size_t size;
+ (void)sep;
+
+ size = sizeof(sa);
+ if (recvfrom(s, (char *)&result, sizeof(result), 0, &sa, &size) < 0)
+ return;
+ result = machtime();
+ (void) sendto(s, (char *) &result, sizeof(result), 0, &sa, sizeof(sa));
+}
+#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_TIME */
+
+
+#ifdef CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DAYTIME
+/* Return human-readable time of day */
+static int
+human_readable_time_sprintf(char *buffer)
+{
+ time_t clocc = time(NULL);
+
+ return sprintf(buffer, "%.24s\r\n", ctime(&clocc));
+}
+
+static void
+daytime_stream(int s, struct servtab *sep)
+{
+ char buffer[256];
+ size_t st = human_readable_time_sprintf(buffer);
+
+ (void)sep;
+
+ write(s, buffer, st);
+}
+
+/* Return human-readable time of day */
+static void
+daytime_dg(int s, struct servtab *sep)
+{
+ char buffer[256];
+ struct sockaddr sa;
+ size_t size;
+
+ (void)sep;
+
+ size = sizeof(sa);
+ if (recvfrom(s, buffer, sizeof(buffer), 0, &sa, &size) < 0)
+ return;
+ size = human_readable_time_sprintf(buffer);
+ sendto(s, buffer, size, 0, &sa, sizeof(sa));
+}
+#endif /* CONFIG_FEATURE_INETD_SUPPORT_BILTIN_DAYTIME */