* setuid()
*/
+//usage:#define inetd_trivial_usage
+//usage: "[-fe] [-q N] [-R N] [CONFFILE]"
+//usage:#define inetd_full_usage "\n\n"
+//usage: "Listen for network connections and launch programs\n"
+//usage: "\n -f Run in foreground"
+//usage: "\n -e Log to stderr"
+//usage: "\n -q N Socket listen queue (default: 128)"
+//usage: "\n -R N Pause services after N connects/min"
+//usage: "\n (default: 0 - disabled)"
+
#include <syslog.h>
+#include <sys/resource.h> /* setrlimit */
+#include <sys/socket.h> /* un.h may need this */
#include <sys/un.h>
#include "libbb.h"
#if ENABLE_FEATURE_INETD_RPC
-#include <rpc/rpc.h>
-#include <rpc/pmap_clnt.h>
+# if defined(__UCLIBC__) && ! defined(__UCLIBC_HAS_RPC__)
+# error "You need to build uClibc with UCLIBC_HAS_RPC for NFS support"
+# endif
+# include <rpc/rpc.h>
+# include <rpc/pmap_clnt.h>
#endif
#if !BB_MMU
#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 0
#endif
-#define _PATH_INETDPID "/var/run/inetd.pid"
-
#define CNT_INTERVAL 60 /* servers in CNT_INTERVAL sec. */
#define RETRYTIME 60 /* retry after bind or server fail */
#ifdef INETD_BUILTINS_ENABLED
/* Echo received data */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
-static void echo_stream(int, servtab_t *);
-static void echo_dg(int, servtab_t *);
+static void FAST_FUNC echo_stream(int, servtab_t *);
+static void FAST_FUNC echo_dg(int, servtab_t *);
#endif
/* Internet /dev/null */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
-static void discard_stream(int, servtab_t *);
-static void discard_dg(int, servtab_t *);
+static void FAST_FUNC discard_stream(int, servtab_t *);
+static void FAST_FUNC discard_dg(int, servtab_t *);
#endif
/* Return 32 bit time since 1900 */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
-static void machtime_stream(int, servtab_t *);
-static void machtime_dg(int, servtab_t *);
+static void FAST_FUNC machtime_stream(int, servtab_t *);
+static void FAST_FUNC machtime_dg(int, servtab_t *);
#endif
/* Return human-readable time */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
-static void daytime_stream(int, servtab_t *);
-static void daytime_dg(int, servtab_t *);
+static void FAST_FUNC daytime_stream(int, servtab_t *);
+static void FAST_FUNC daytime_dg(int, servtab_t *);
#endif
/* Familiar character generator */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
-static void chargen_stream(int, servtab_t *);
-static void chargen_dg(int, servtab_t *);
+static void FAST_FUNC chargen_stream(int, servtab_t *);
+static void FAST_FUNC chargen_dg(int, servtab_t *);
#endif
struct builtin {
/* NB: not necessarily NUL terminated */
char bi_service7[7]; /* internally provided service name */
uint8_t bi_fork; /* 1 if stream fn should run in child */
- void (*bi_stream_fn)(int, servtab_t *);
- void (*bi_dgram_fn)(int, servtab_t *);
+ void (*bi_stream_fn)(int, servtab_t *) FAST_FUNC;
+ void (*bi_dgram_fn)(int, servtab_t *) FAST_FUNC;
};
static const struct builtin builtins[] = {
struct rlimit rlim_ofile;
servtab_t *serv_list;
int global_queuelen;
- int maxsock; /* max fd# in allsock, -1: unknown */
+ int maxsock; /* max fd# in allsock, -1: unknown */
/* whenever maxsock grows, prev_maxsock is set to new maxsock,
* but if maxsock is set to -1, prev_maxsock is not changed */
int prev_maxsock;
fd_set allsock;
/* Used in next_line(), and as scratch read buffer */
char line[256]; /* _at least_ 256, see LINE_SIZE */
-};
+} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
enum { LINE_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line) };
struct BUG_G_too_big {
config_filename = "/etc/inetd.conf"; \
} while (0)
+#if 1
+# define dbg(...) ((void)0)
+#else
+# define dbg(...) \
+do { \
+ int dbg_fd = open("inetd_debug.log", O_WRONLY | O_CREAT | O_APPEND, 0666); \
+ if (dbg_fd >= 0) { \
+ fdprintf(dbg_fd, "%d: ", getpid()); \
+ fdprintf(dbg_fd, __VA_ARGS__); \
+ close(dbg_fd); \
+ } \
+} while (0)
+#endif
+
static void maybe_close(int fd)
{
- if (fd >= 0)
+ if (fd >= 0) {
close(fd);
+ dbg("closed fd:%d\n", fd);
+ }
}
// TODO: move to libbb?
{
if (fd >= 0) {
FD_CLR(fd, &allsock);
+ dbg("stopped listening on fd:%d\n", fd);
maxsock = -1;
+ dbg("maxsock:%d\n", maxsock);
}
}
{
if (fd >= 0) {
FD_SET(fd, &allsock);
+ dbg("started listening on fd:%d\n", fd);
if (maxsock >= 0 && fd > maxsock) {
prev_maxsock = maxsock = fd;
+ dbg("maxsock:%d\n", maxsock);
if ((rlim_t)fd > rlim_ofile_cur - FD_MARGIN)
bump_nofile();
}
maxsock = fd;
fd++;
}
+ dbg("recalculated maxsock:%d\n", maxsock);
prev_maxsock = maxsock;
if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN)
bump_nofile();
/* zero out the port for all RPC services; let bind()
* find one. */
- set_nport(sep->se_lsa, 0);
+ set_nport(&sep->se_lsa->u.sa, 0);
/* for RPC services, attempt to use a reserved port
* if they are going to be running as root. */
rearm_alarm();
return;
}
- if (sep->se_socktype == SOCK_STREAM)
+
+ if (sep->se_socktype == SOCK_STREAM) {
listen(fd, global_queuelen);
+ dbg("new sep->se_fd:%d (stream)\n", fd);
+ } else {
+ dbg("new sep->se_fd:%d (!stream)\n", fd);
+ }
add_fd_to_set(fd);
sep->se_fd = fd;
argc = 0;
while ((arg = token[6+argc]) != NULL && argc < MAXARGV)
sep->se_argv[argc++] = xstrdup(arg);
+ /* Some inetd.conf files have no argv's, not even argv[0].
+ * Fix them up.
+ * (Technically, programs can be execed with argv[0] = NULL,
+ * but many programs do not like that at all) */
+ if (argc == 0)
+ sep->se_argv[0] = xstrdup(sep->se_program);
/* catch mixups. "<service> stream udp ..." == wtf */
if (sep->se_socktype == SOCK_STREAM) {
}
if (LONE_CHAR(sep->se_local_hostname, '*')) {
lsa = xzalloc_lsa(sep->se_family);
- set_nport(lsa, port);
+ set_nport(&lsa->u.sa, port);
} else {
lsa = host_and_af2sockaddr(sep->se_local_hostname,
ntohs(port), sep->se_family);
* new config file doesnt have them. */
block_CHLD_HUP_ALRM(&omask);
sepp = &serv_list;
- while ((sep = *sepp)) {
+ while ((sep = *sepp) != NULL) {
if (sep->se_checked) {
sepp = &sep->se_next;
continue;
continue;
/* One of our "wait" services */
if (WIFEXITED(status) && WEXITSTATUS(status))
- bb_error_msg("%s: exit status 0x%x",
+ bb_error_msg("%s: exit status %u",
sep->se_program, WEXITSTATUS(status));
else if (WIFSIGNALED(status))
- bb_error_msg("%s: exit signal 0x%x",
+ bb_error_msg("%s: exit signal %u",
sep->se_program, WTERMSIG(status));
sep->se_wait = 1;
add_fd_to_set(sep->se_fd);
if (ENABLE_FEATURE_CLEAN_UP)
close(sep->se_fd);
}
- remove_pidfile(_PATH_INETDPID);
+ remove_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
exit(EXIT_SUCCESS);
}
else
bb_sanitize_stdio();
if (!(opt & 4)) {
- openlog(applet_name, LOG_PID, LOG_DAEMON);
+ /* LOG_NDELAY: connect to syslog daemon NOW.
+ * Otherwise, we may open syslog socket
+ * in vforked child, making opened fds and syslog()
+ * internal state inconsistent.
+ * This was observed to leak file descriptors. */
+ openlog(applet_name, LOG_PID | LOG_NDELAY, LOG_DAEMON);
logmode = LOGMODE_SYSLOG;
}
setgroups(1, &gid);
}
- write_pidfile(_PATH_INETDPID);
+ write_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
/* never fails under Linux (except if you pass it bad arguments) */
getrlimit(RLIMIT_NOFILE, &rlim_ofile);
sigaddset(&sa.sa_mask, SIGALRM);
sigaddset(&sa.sa_mask, SIGCHLD);
sigaddset(&sa.sa_mask, SIGHUP);
+//FIXME: explain why no SA_RESTART
+//FIXME: retry_network_setup is unsafe to run in signal handler (many reasons)!
sa.sa_handler = retry_network_setup;
sigaction_set(SIGALRM, &sa);
+//FIXME: reread_config_file is unsafe to run in signal handler(many reasons)!
sa.sa_handler = reread_config_file;
sigaction_set(SIGHUP, &sa);
+//FIXME: reap_child is unsafe to run in signal handler (uses stdio)!
sa.sa_handler = reap_child;
sigaction_set(SIGCHLD, &sa);
+//FIXME: clean_up_and_exit is unsafe to run in signal handler (uses stdio)!
sa.sa_handler = clean_up_and_exit;
sigaction_set(SIGTERM, &sa);
sa.sa_handler = clean_up_and_exit;
}
continue;
}
+ dbg("ready_fd_cnt:%d\n", ready_fd_cnt);
for (sep = serv_list; ready_fd_cnt && sep; sep = sep->se_next) {
if (sep->se_fd == -1 || !FD_ISSET(sep->se_fd, &readable))
continue;
+ dbg("ready fd:%d\n", sep->se_fd);
ready_fd_cnt--;
ctrl = sep->se_fd;
accepted_fd = -1;
if (!sep->se_wait) {
if (sep->se_socktype == SOCK_STREAM) {
ctrl = accepted_fd = accept(sep->se_fd, NULL, NULL);
+ dbg("accepted_fd:%d\n", accepted_fd);
if (ctrl < 0) {
if (errno != EINTR)
bb_perror_msg("accept (for %s)", sep->se_service);
* (can create many copies of same child, etc).
* Parent must create and use new socket instead. */
new_udp_fd = socket(sep->se_family, SOCK_DGRAM, 0);
+ dbg("new_udp_fd:%d\n", new_udp_fd);
if (new_udp_fd < 0) { /* error: eat packet, forget about it */
udp_err:
recv(sep->se_fd, line, LINE_SIZE, MSG_DONTWAIT);
continue;
}
setsockopt_reuseaddr(new_udp_fd);
- /* TODO: better do bind after vfork in parent,
+ /* TODO: better do bind after fork in parent,
* so that we don't have two wildcard bound sockets
* even for a brief moment? */
if (bind(new_udp_fd, &sep->se_lsa->u.sa, sep->se_lsa->len) < 0) {
+ dbg("bind(new_udp_fd) failed\n");
close(new_udp_fd);
goto udp_err;
}
+ dbg("bind(new_udp_fd) succeeded\n");
}
}
sep->se_count = 0;
rearm_alarm(); /* will revive it in RETRYTIME sec */
restore_sigmask(&omask);
+ maybe_close(new_udp_fd);
maybe_close(accepted_fd);
continue; /* -> check next fd in fd set */
}
pid = vfork();
if (pid < 0) { /* fork error */
- bb_perror_msg("fork");
+ bb_perror_msg("vfork"+1);
sleep(1);
restore_sigmask(&omask);
+ maybe_close(new_udp_fd);
maybe_close(accepted_fd);
continue; /* -> check next fd in fd set */
}
if (pid == 0)
pid--; /* -1: "we did fork and we are child" */
}
- /* if pid == 0 here, we never forked */
+ /* if pid == 0 here, we didn't fork */
if (pid > 0) { /* parent */
if (sep->se_wait) {
- /* tcp wait: we passed listening socket to child,
+ /* wait: we passed socket to child,
* will wait for child to terminate */
sep->se_wait = pid;
remove_fd_from_set(sep->se_fd);
/* udp nowait: child connected the socket,
* we created and will use new, unconnected one */
xmove_fd(new_udp_fd, sep->se_fd);
+ dbg("moved new_udp_fd:%d to sep->se_fd:%d\n", new_udp_fd, sep->se_fd);
}
restore_sigmask(&omask);
maybe_close(accepted_fd);
continue; /* -> check next fd in fd set */
}
- /* we are either child or didn't vfork at all */
+ /* we are either child or didn't fork at all */
#ifdef INETD_BUILTINS_ENABLED
if (sep->se_builtin) {
- if (pid) { /* "pid" is -1: we did vfork */
+ if (pid) { /* "pid" is -1: we did fork */
close(sep->se_fd); /* listening socket */
+ dbg("closed sep->se_fd:%d\n", sep->se_fd);
logmode = LOGMODE_NONE; /* make xwrite etc silent */
}
restore_sigmask(&omask);
sep->se_builtin->bi_stream_fn(ctrl, sep);
else
sep->se_builtin->bi_dgram_fn(ctrl, sep);
- if (pid) /* we did vfork */
+ if (pid) /* we did fork */
_exit(EXIT_FAILURE);
maybe_close(accepted_fd);
continue; /* -> check next fd in fd set */
setsid();
/* "nowait" udp */
if (new_udp_fd >= 0) {
- len_and_sockaddr *lsa = xzalloc_lsa(sep->se_family);
+ len_and_sockaddr *lsa;
+ int r;
+
+ close(new_udp_fd);
+ dbg("closed new_udp_fd:%d\n", new_udp_fd);
+ lsa = xzalloc_lsa(sep->se_family);
/* peek at the packet and remember peer addr */
- int r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
+ r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
&lsa->u.sa, &lsa->len);
if (r < 0)
goto do_exit1;
* only packets from this peer will be recv'ed,
* and bare write()/send() will work on it */
connect(ctrl, &lsa->u.sa, lsa->len);
+ dbg("connected ctrl:%d to remote peer\n", ctrl);
free(lsa);
}
/* prepare env and exec program */
bb_error_msg("non-root must run services as himself");
goto do_exit1;
}
- if (pwd->pw_uid) {
+ if (pwd->pw_uid != 0) {
if (sep->se_group)
pwd->pw_gid = grp->gr_gid;
/* initgroups, setgid, setuid: */
if (rlim_ofile.rlim_cur != rlim_ofile_cur)
if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
bb_perror_msg("setrlimit");
- closelog();
- xmove_fd(ctrl, 0);
- xdup2(0, 1);
- xdup2(0, 2);
- /* NB: among others, this loop closes listening socket
+
+ /* closelog(); - WRONG. we are after vfork,
+ * this may confuse syslog() internal state.
+ * Let's hope libc sets syslog fd to CLOEXEC...
+ */
+ xmove_fd(ctrl, STDIN_FILENO);
+ xdup2(STDIN_FILENO, STDOUT_FILENO);
+ dbg("moved ctrl:%d to fd 0,1[,2]\n", ctrl);
+ /* manpages of inetd I managed to find either say
+ * that stderr is also redirected to the network,
+ * or do not talk about redirection at all (!) */
+ if (!sep->se_wait) /* only for usual "tcp nowait" */
+ xdup2(STDIN_FILENO, STDERR_FILENO);
+ /* NB: among others, this loop closes listening sockets
* for nowait stream children */
for (sep2 = serv_list; sep2; sep2 = sep2->se_next)
- maybe_close(sep2->se_fd);
+ if (sep2->se_fd != ctrl)
+ maybe_close(sep2->se_fd);
sigaction_set(SIGPIPE, &saved_pipe_handler);
restore_sigmask(&omask);
+ dbg("execing:'%s'\n", sep->se_program);
BB_EXECVP(sep->se_program, sep->se_argv);
- bb_perror_msg("exec %s", sep->se_program);
+ bb_perror_msg("can't execute '%s'", sep->se_program);
do_exit1:
/* eat packet in udp case */
if (sep->se_socktype != SOCK_STREAM)
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
/* Echo service -- echo data back. */
/* ARGSUSED */
-static void echo_stream(int s, servtab_t *sep UNUSED_PARAM)
+static void FAST_FUNC echo_stream(int s, servtab_t *sep UNUSED_PARAM)
{
#if BB_MMU
while (1) {
/* on failure we return to main, which does exit(EXIT_FAILURE) */
#endif
}
-static void echo_dg(int s, servtab_t *sep)
+static void FAST_FUNC echo_dg(int s, servtab_t *sep)
{
enum { BUFSIZE = 12*1024 }; /* for jumbo sized packets! :) */
char *buf = xmalloc(BUFSIZE); /* too big for stack */
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
/* Discard service -- ignore data. */
/* ARGSUSED */
-static void discard_stream(int s, servtab_t *sep UNUSED_PARAM)
+static void FAST_FUNC discard_stream(int s, servtab_t *sep UNUSED_PARAM)
{
#if BB_MMU
while (safe_read(s, line, LINE_SIZE) > 0)
#endif
}
/* ARGSUSED */
-static void discard_dg(int s, servtab_t *sep UNUSED_PARAM)
+static void FAST_FUNC discard_dg(int s, servtab_t *sep UNUSED_PARAM)
{
/* dgram builtins are non-forking - DONT BLOCK! */
recv(s, line, LINE_SIZE, MSG_DONTWAIT);
int i;
end_ring = ring;
- for (i = 0; i <= 128; ++i)
- if (isprint(i))
- *end_ring++ = i;
+ for (i = ' '; i < 127; i++)
+ *end_ring++ = i;
}
/* Character generator. MMU arches only. */
/* ARGSUSED */
-static void chargen_stream(int s, servtab_t *sep UNUSED_PARAM)
+static void FAST_FUNC chargen_stream(int s, servtab_t *sep UNUSED_PARAM)
{
char *rs;
int len;
}
}
/* ARGSUSED */
-static void chargen_dg(int s, servtab_t *sep)
+static void FAST_FUNC chargen_dg(int s, servtab_t *sep)
{
int len;
char text[LINESIZ + 2];
return htonl((uint32_t)(tv.tv_sec + 2208988800));
}
/* ARGSUSED */
-static void machtime_stream(int s, servtab_t *sep UNUSED_PARAM)
+static void FAST_FUNC machtime_stream(int s, servtab_t *sep UNUSED_PARAM)
{
uint32_t result;
result = machtime();
full_write(s, &result, sizeof(result));
}
-static void machtime_dg(int s, servtab_t *sep)
+static void FAST_FUNC machtime_dg(int s, servtab_t *sep)
{
uint32_t result;
len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
/* Return human-readable time of day */
/* ARGSUSED */
-static void daytime_stream(int s, servtab_t *sep UNUSED_PARAM)
+static void FAST_FUNC daytime_stream(int s, servtab_t *sep UNUSED_PARAM)
{
time_t t;
t = time(NULL);
fdprintf(s, "%.24s\r\n", ctime(&t));
}
-static void daytime_dg(int s, servtab_t *sep)
+static void FAST_FUNC daytime_dg(int s, servtab_t *sep)
{
time_t t;
len_and_sockaddr *lsa = alloca(LSA_LEN_SIZE + sep->se_lsa->len);