* tening service socket, and must accept at least one connection request
* before exiting. Such a server would normally accept and process incoming
* connection requests until a timeout.
- *
- * In short: "stream" can be "wait" or "nowait"; "dgram" must be "wait".
+ */
+
+/* Despite of above doc saying that dgram services must use "wait",
+ * "udp nowait" servers are implemented in busyboxed inetd.
+ * IPv6 addresses are also implemented. However, they may look ugly -
+ * ":::service..." means "address '::' (IPv6 wildcard addr)":"service"...
+ * You have to put "tcp6"/"udp6" in protocol field to select IPv6.
*/
/* Here's the scoop concerning the user[:group] feature:
* 1) group is not specified:
* a) user = root: NO setuid() or setgid() is done
- * b) other: setgid(primary group as found in passwd)
- * initgroups(name, primary group)
+ * b) other: initgroups(name, primary group)
+ * setgid(primary group as found in passwd)
* setuid()
* 2) group is specified:
* a) user = root: setgid(specified group)
* NO initgroups()
* NO setuid()
- * b) other: setgid(specified group)
- * initgroups(name, specified group)
+ * b) other: initgroups(name, specified group)
+ * setgid(specified group)
* 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 */
smallint se_checked; /* looked at during merge */
unsigned se_max; /* allowed instances per minute */
unsigned se_count; /* number started since se_time */
- unsigned se_time; /* whem we started counting */
+ unsigned se_time; /* when we started counting */
char *se_user; /* user name to run as */
char *se_group; /* group name to run as, can be NULL */
#ifdef INETD_BUILTINS_ENABLED
#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 */
+ /* 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;
- int maxsock;
unsigned max_concurrency;
smallint alarm_armed;
uid_t real_uid; /* user ID who ran us */
- unsigned config_lineno;
const char *config_filename;
- FILE *fconfig;
+ parser_t *parser;
char *default_local_hostname;
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
char *end_ring;
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 {
#define rlim_ofile (G.rlim_ofile )
#define serv_list (G.serv_list )
#define global_queuelen (G.global_queuelen)
-#define prev_maxsock (G.prev_maxsock )
#define maxsock (G.maxsock )
+#define prev_maxsock (G.prev_maxsock )
#define max_concurrency (G.max_concurrency)
#define alarm_armed (G.alarm_armed )
#define real_uid (G.real_uid )
-#define config_lineno (G.config_lineno )
#define config_filename (G.config_filename)
-#define fconfig (G.fconfig )
+#define parser (G.parser )
#define default_local_hostname (G.default_local_hostname)
#define first_ps_byte (G.first_ps_byte )
#define last_ps_byte (G.last_ps_byte )
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?
lsa = xzalloc(LSA_LEN_SIZE + sz);
lsa->len = sz;
lsa->u.sa.sa_family = family;
- return lsa;
+ return lsa;
}
static void rearm_alarm(void)
{
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;
- if ((rlim_t)maxsock > rlim_ofile_cur - FD_MARGIN)
+ dbg("maxsock:%d\n", maxsock);
+ if ((rlim_t)fd > rlim_ofile_cur - FD_MARGIN)
bump_nofile();
}
}
static void recalculate_maxsock(void)
{
int fd = 0;
+
+ /* We may have no services, in this case maxsock should still be >= 0
+ * (code elsewhere is not happy with maxsock == -1) */
+ maxsock = 0;
while (fd <= prev_maxsock) {
if (FD_ISSET(fd, &allsock))
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;
{
free(default_local_hostname);
default_local_hostname = xstrdup("*");
- if (fconfig != NULL)
- fclose(fconfig);
- config_lineno = 0;
- fconfig = fopen_or_warn(config_filename, "r");
- return (fconfig != NULL);
+ if (parser != NULL)
+ config_close(parser);
+ parser = config_open(config_filename);
+ return (parser != NULL);
}
static void close_config_file(void)
{
- if (fconfig) {
- fclose(fconfig);
- fconfig = NULL;
- }
-}
-
-static char *next_line(void)
-{
- if (fgets(line, LINE_SIZE, fconfig) == NULL)
- return NULL;
- config_lineno++;
- *strchrnul(line, '\n') = '\0';
- return line;
-}
-
-static char *next_word(char **cpp)
-{
- char *start;
- char *cp = *cpp;
-
- if (cp == NULL)
- return NULL;
- again:
- while (*cp == ' ' || *cp == '\t')
- cp++;
- if (*cp == '\0') {
- int c = getc(fconfig);
- ungetc(c, fconfig);
- if (c == ' ' || c == '\t') {
- cp = next_line();
- if (cp)
- goto again;
- }
- *cpp = NULL;
- return NULL;
+ if (parser) {
+ config_close(parser);
+ parser = NULL;
}
- start = cp;
- while (*cp && *cp != ' ' && *cp != '\t')
- cp++;
- if (*cp != '\0')
- *cp++ = '\0';
-
- *cpp = cp;
- return start;
}
static void free_servtab_strings(servtab_t *cp)
}
/* gcc generates much more code if this is inlined */
-static NOINLINE servtab_t *parse_one_line(void)
+static servtab_t *parse_one_line(void)
{
int argc;
- char *p, *cp, *arg;
+ char *token[6+MAXARGV];
+ char *p, *arg;
char *hostdelim;
servtab_t *sep;
servtab_t *nsep;
new:
sep = new_servtab();
more:
- while ((cp = next_line()) && *cp == '#')
- continue; /* skip comment lines */
- if (cp == NULL) {
+ argc = config_read(parser, token, 6+MAXARGV, 1, "# \t", PARSE_NORMAL);
+ if (!argc) {
free(sep);
return NULL;
}
- arg = next_word(&cp);
- if (arg == NULL) /* a blank line. */
- goto more;
-
/* [host:]service socktype proto wait user[:group] prog [args] */
/* Check for "host:...." line */
+ arg = token[0];
hostdelim = strrchr(arg, ':');
if (hostdelim) {
*hostdelim = '\0';
sep->se_local_hostname = xstrdup(arg);
arg = hostdelim + 1;
- if (*arg == '\0') {
- arg = next_word(&cp);
- if (arg == NULL) {
- /* Line has just "host:", change the
- * default host for the following lines. */
- free(default_local_hostname);
- default_local_hostname = sep->se_local_hostname;
- goto more;
- }
+ if (*arg == '\0' && argc == 1) {
+ /* Line has just "host:", change the
+ * default host for the following lines. */
+ free(default_local_hostname);
+ default_local_hostname = sep->se_local_hostname;
+ goto more;
}
} else
sep->se_local_hostname = xstrdup(default_local_hostname);
/* service socktype proto wait user[:group] prog [args] */
sep->se_service = xstrdup(arg);
+
/* socktype proto wait user[:group] prog [args] */
- arg = next_word(&cp);
- if (arg == NULL) {
+ if (argc < 6) {
parse_err:
bb_error_msg("parse error on line %u, line is ignored",
- config_lineno);
+ parser->lineno);
free_servtab_strings(sep);
/* Just "goto more" can make sep to carry over e.g.
* "rpc"-ness (by having se_rpcver_lo != 0).
free(sep);
goto new;
}
+
{
- static int8_t SOCK_xxx[] ALIGN1 = {
+ static const int8_t SOCK_xxx[] ALIGN1 = {
-1,
SOCK_STREAM, SOCK_DGRAM, SOCK_RDM,
SOCK_SEQPACKET, SOCK_RAW
sep->se_socktype = SOCK_xxx[1 + index_in_strings(
"stream""\0" "dgram""\0" "rdm""\0"
"seqpacket""\0" "raw""\0"
- , arg)];
+ , token[1])];
}
/* {unix,[rpc/]{tcp,udp}[6]} wait user[:group] prog [args] */
- sep->se_proto = arg = xstrdup(next_word(&cp));
- if (arg == NULL)
- goto parse_err;
+ sep->se_proto = arg = xstrdup(token[2]);
if (strcmp(arg, "unix") == 0) {
sep->se_family = AF_UNIX;
} else {
if (*p == '-') {
p++;
n = bb_strtou(p, &p, 10);
- if (n > INT_MAX || n < sep->se_rpcver_lo)
+ if (n > INT_MAX || (int)n < sep->se_rpcver_lo)
goto bad_ver_spec;
sep->se_rpcver_hi = n;
}
}
/* [no]wait[.max] user[:group] prog [args] */
- arg = next_word(&cp);
- if (arg == NULL)
- goto parse_err;
+ arg = token[3];
sep->se_max = max_concurrency;
p = strchr(arg, '.');
if (p) {
goto parse_err;
/* user[:group] prog [args] */
- sep->se_user = xstrdup(next_word(&cp));
- if (sep->se_user == NULL)
- goto parse_err;
+ sep->se_user = xstrdup(token[4]);
arg = strchr(sep->se_user, '.');
if (arg == NULL)
arg = strchr(sep->se_user, ':');
}
/* prog [args] */
- sep->se_program = xstrdup(next_word(&cp));
- if (sep->se_program == NULL)
- goto parse_err;
+ sep->se_program = xstrdup(token[5]);
#ifdef INETD_BUILTINS_ENABLED
if (strcmp(sep->se_program, "internal") == 0
&& strlen(sep->se_service) <= 7
&& (sep->se_socktype == SOCK_STREAM
|| sep->se_socktype == SOCK_DGRAM)
) {
- int i;
+ unsigned i;
for (i = 0; i < ARRAY_SIZE(builtins); i++)
if (strncmp(builtins[i].bi_service7, sep->se_service, 7) == 0)
goto found_bi;
}
#endif
argc = 0;
- while ((arg = next_word(&cp)) != NULL && argc < MAXARGV)
+ 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 (sep->se_socktype == SOCK_DGRAM) {
if (sep->se_proto_no == IPPROTO_TCP)
goto parse_err;
- /* "udp nowait" is a small fork bomb :) */
- if (!sep->se_wait)
- goto parse_err;
}
+// bb_info_msg(
+// "ENTRY[%s][%s][%s][%d][%d][%d][%d][%d][%s][%s][%s]",
+// sep->se_local_hostname, sep->se_service, sep->se_proto, sep->se_wait, sep->se_proto_no,
+// sep->se_max, sep->se_count, sep->se_time, sep->se_user, sep->se_group, sep->se_program);
+
/* check if the hostname specifier is a comma separated list
* of hostnames. we'll make new entries for each address. */
while ((hostdelim = strrchr(sep->se_local_hostname, ',')) != NULL) {
return 1;
}
-static void reread_config_file(int sig ATTRIBUTE_UNUSED)
+static void reread_config_file(int sig UNUSED_PARAM)
{
servtab_t *sep, *cp, **sepp;
len_and_sockaddr *lsa;
sigset_t omask;
unsigned n;
uint16_t port;
+ int save_errno = errno;
if (!reopen_config_file())
- return;
+ goto ret;
for (sep = serv_list; sep; sep = sep->se_next)
sep->se_checked = 0;
}
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;
free(sep);
}
restore_sigmask(&omask);
+ ret:
+ errno = save_errno;
}
-static void reap_child(int sig ATTRIBUTE_UNUSED)
+static void reap_child(int sig UNUSED_PARAM)
{
pid_t pid;
int status;
pid = wait_any_nohang(&status);
if (pid <= 0)
break;
- for (sep = serv_list; sep; sep = sep->se_next)
- if (sep->se_wait == pid) {
- /* One of our "wait" services */
- if (WIFEXITED(status) && WEXITSTATUS(status))
- bb_error_msg("%s: exit status 0x%x",
- sep->se_program, WEXITSTATUS(status));
- else if (WIFSIGNALED(status))
- bb_error_msg("%s: exit signal 0x%x",
- sep->se_program, WTERMSIG(status));
- sep->se_wait = 1;
- add_fd_to_set(sep->se_fd);
- }
+ for (sep = serv_list; sep; sep = sep->se_next) {
+ if (sep->se_wait != pid)
+ continue;
+ /* One of our "wait" services */
+ if (WIFEXITED(status) && WEXITSTATUS(status))
+ bb_error_msg("%s: exit status %u",
+ sep->se_program, WEXITSTATUS(status));
+ else if (WIFSIGNALED(status))
+ bb_error_msg("%s: exit signal %u",
+ sep->se_program, WTERMSIG(status));
+ sep->se_wait = 1;
+ add_fd_to_set(sep->se_fd);
+ break;
+ }
}
errno = save_errno;
}
-static void retry_network_setup(int sig ATTRIBUTE_UNUSED)
+static void retry_network_setup(int sig UNUSED_PARAM)
{
+ int save_errno = errno;
servtab_t *sep;
alarm_armed = 0;
#endif
}
}
+ errno = save_errno;
}
-static void clean_up_and_exit(int sig ATTRIBUTE_UNUSED)
+static void clean_up_and_exit(int sig UNUSED_PARAM)
{
servtab_t *sep;
if (ENABLE_FEATURE_CLEAN_UP)
close(sep->se_fd);
}
- remove_pidfile(_PATH_INETDPID);
- exit(0);
+ remove_pidfile(CONFIG_PID_FILE_PATH "/inetd.pid");
+ exit(EXIT_SUCCESS);
}
int inetd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int inetd_main(int argc, char **argv)
+int inetd_main(int argc UNUSED_PARAM, char **argv)
{
struct sigaction sa, saved_pipe_handler;
servtab_t *sep, *sep2;
else
bb_sanitize_stdio();
if (!(opt & 4)) {
- openlog(applet_name, LOG_PID | LOG_NOWAIT, 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;
for (;;) {
int ready_fd_cnt;
- int ctrl, accepted_fd;
+ int ctrl, accepted_fd, new_udp_fd;
fd_set readable;
if (maxsock < 0)
readable = allsock; /* struct copy */
/* if there are no fds to wait on, we will block
- * until signal wakes us up */
+ * until signal wakes us up (maxsock == 0, but readable
+ * never contains fds 0 and 1...) */
ready_fd_cnt = select(maxsock + 1, &readable, NULL, NULL, NULL);
if (ready_fd_cnt < 0) {
if (errno != EINTR) {
}
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 && sep->se_socktype == SOCK_STREAM) {
- ctrl = accepted_fd = accept(sep->se_fd, NULL, NULL);
- if (ctrl < 0) {
- if (errno != EINTR)
- bb_perror_msg("accept (for %s)", sep->se_service);
- continue;
+ new_udp_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);
+ continue;
+ }
+ }
+ /* "nowait" udp */
+ if (sep->se_socktype == SOCK_DGRAM
+ && sep->se_family != AF_UNIX
+ ) {
+/* How udp "nowait" works:
+ * child peeks at (received and buffered by kernel) UDP packet,
+ * performs connect() on the socket so that it is linked only
+ * to this peer. But this also affects parent, because descriptors
+ * are shared after fork() a-la dup(). When parent performs
+ * select(), it will see this descriptor connected to the peer (!)
+ * and still readable, will act on it and mess things up
+ * (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 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) {
+ /* wait: we passed socket to child,
+ * will wait for child to terminate */
sep->se_wait = pid;
remove_fd_from_set(sep->se_fd);
- /* we passed listening socket to child,
- * will wait for child to terminate */
+ }
+ if (new_udp_fd >= 0) {
+ /* 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);
if (sep->se_builtin) {
if (pid) { /* "pid" is -1: we did fork */
close(sep->se_fd); /* listening socket */
- logmode = 0; /* make xwrite etc silent */
+ dbg("closed sep->se_fd:%d\n", sep->se_fd);
+ logmode = LOGMODE_NONE; /* make xwrite etc silent */
}
restore_sigmask(&omask);
if (sep->se_socktype == SOCK_STREAM)
else
sep->se_builtin->bi_dgram_fn(ctrl, sep);
if (pid) /* we did fork */
- _exit(0);
+ _exit(EXIT_FAILURE);
maybe_close(accepted_fd);
continue; /* -> check next fd in fd set */
}
#endif
/* child */
setsid();
-#if 0
-/* This does not work.
- * Actually, it _almost_ works. The idea behind it is: child
- * can peek at (already received and buffered by kernel) UDP packet,
- * and perform connect() on the socket so that it is linked only
- * to this peer. But this also affects parent, because descriptors
- * are shared after fork() a-la dup(). When parent returns to
- * select(), it will see this descriptor attached to the peer (!)
- * and likely still readable, will act on it and mess things up
- * (can create many copies of same child, etc).
- * If child will create new socket instead, then bind() and
- * connect() it to peer's address, descriptor aliasing problem
- * is solved, but first packet cannot be "transferred" to the new
- * socket. It is not a problem if child can account for this,
- * but our child will exec - and exec'ed program does not know
- * about this "lost packet" problem! Pity... */
- /* "nowait" udp[6]. Hmmm... */
- if (!sep->se_wait
- && sep->se_socktype == SOCK_DGRAM
- && sep->se_family != AF_UNIX
- ) {
- len_and_sockaddr *lsa = xzalloc_lsa(sep->se_family);
+ /* "nowait" udp */
+ if (new_udp_fd >= 0) {
+ 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)
- /* make this socket "connected" to peer addr:
- * only packets from this peer will be recv'ed,
- * and bare write()/send() will work on it */
- connect(ctrl, &lsa->u.sa, lsa->len);
+ if (r < 0)
+ goto do_exit1;
+ /* make this socket "connected" to peer addr:
+ * 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);
}
-#endif
/* prepare env and exec program */
pwd = getpwnam(sep->se_user);
if (pwd == NULL) {
- bb_error_msg("%s: no such user", sep->se_user);
+ bb_error_msg("%s: no such %s", sep->se_user, "user");
goto do_exit1;
}
if (sep->se_group && (grp = getgrnam(sep->se_group)) == NULL) {
- bb_error_msg("%s: no such group", sep->se_group);
+ bb_error_msg("%s: no such %s", sep->se_group, "group");
goto do_exit1;
}
if (real_uid != 0 && real_uid != pwd->pw_uid) {
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;
- xsetgid(pwd->pw_gid);
- initgroups(pwd->pw_name, pwd->pw_gid);
- xsetuid(pwd->pw_uid);
+ /* initgroups, setgid, setuid: */
+ change_identity(pwd);
} else if (sep->se_group) {
xsetgid(grp->gr_gid);
setgroups(1, &grp->gr_gid);
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)
recv(0, line, LINE_SIZE, MSG_DONTWAIT);
- _exit(1);
+ _exit(EXIT_FAILURE);
} /* for (sep = servtab...) */
} /* for (;;) */
}
+#if !BB_MMU
+static const char *const cat_args[] = { "cat", NULL };
+#endif
+
/*
* Internet services provided internally by inetd:
*/
#if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
/* Echo service -- echo data back. */
/* ARGSUSED */
-static void echo_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
+static void FAST_FUNC echo_stream(int s, servtab_t *sep UNUSED_PARAM)
{
#if BB_MMU
while (1) {
xwrite(s, line, sz);
}
#else
- static const char *const args[] = { "cat", NULL };
- /* no error messages */
- xmove_fd(xopen("/dev/null", O_WRONLY), STDERR_FILENO);
- BB_EXECVP("cat", (char**)args);
- _exit(1);
+ /* We are after vfork here! */
+ /* move network socket to stdin/stdout */
+ xmove_fd(s, STDIN_FILENO);
+ xdup2(STDIN_FILENO, STDOUT_FILENO);
+ /* no error messages please... */
+ close(STDERR_FILENO);
+ xopen(bb_dev_null, O_WRONLY);
+ BB_EXECVP("cat", (char**)cat_args);
+ /* 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. MMU arches only. */
+/* Discard service -- ignore data. */
/* ARGSUSED */
-static void discard_stream(int s, servtab_t *sep ATTRIBUTE_UNUSED)
+static void FAST_FUNC discard_stream(int s, servtab_t *sep UNUSED_PARAM)
{
#if BB_MMU
while (safe_read(s, line, LINE_SIZE) > 0)
continue;
#else
- static const char *const args[] = { "dd", "of=/dev/null", NULL };
- /* no error messages */
- xmove_fd(xopen("/dev/null", O_WRONLY), STDERR_FILENO);
- BB_EXECVP("dd", (char**)args);
- _exit(1);
+ /* We are after vfork here! */
+ /* move network socket to stdin */
+ xmove_fd(s, STDIN_FILENO);
+ /* discard output */
+ close(STDOUT_FILENO);
+ xopen(bb_dev_null, O_WRONLY);
+ /* no error messages please... */
+ xdup2(STDOUT_FILENO, STDERR_FILENO);
+ BB_EXECVP("cat", (char**)cat_args);
+ /* on failure we return to main, which does exit(EXIT_FAILURE) */
#endif
}
/* ARGSUSED */
-static void discard_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
+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)
+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 ATTRIBUTE_UNUSED)
+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 ATTRIBUTE_UNUSED)
+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);