hexedit: position in correct column on "goto" command
[oweals/busybox.git] / networking / inetd.c
index 8a4c9fbf6e0493ef5c07abc00f6f6541a8c47273..67984accb56f297babb293b43af66cf8cd5cdc0c 100644 (file)
@@ -3,6 +3,7 @@
 /*      $OpenBSD: inetd.c,v 1.79 2001/01/30 08:30:57 deraadt Exp $      */
 /*      $NetBSD: inetd.c,v 1.11 1996/02/22 11:14:41 mycroft Exp $       */
 /* Busybox port by Vladimir Oleynik (C) 2001-2005 <dzo@simtreas.ru>     */
+/* IPv6 support, many bug fixes by Denys Vlasenko (c) 2008 */
 /*
  * Copyright (c) 1983,1991 The Regents of the University of California.
  * All rights reserved.
 
 /* Inetd - Internet super-server
  *
- * This program invokes all internet services as needed.
- * connection-oriented services are invoked each time a
+ * This program invokes configured services when a connection
+ * from a peer is established or a datagram arrives.
+ * 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
+ * expected to do a getpeername to find out peer's 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".
+ * on file descriptor 0. peer's address can be obtained
+ * using recvfrom.
  *
  * Inetd uses a configuration file which is read at startup
  * and, possibly, at some later time in response to a hangup signal.
  * order shown below.  Continuation lines for an entry must begin with
  * a space or tab.  All fields must be present in each entry.
  *
- *      service name                    must be in /etc/services
- *      socket type                     stream/dgram/raw/rdm/seqpacket
+ *      service_name                    must be in /etc/services
+ *      socket_type                     stream/dgram/raw/rdm/seqpacket
  *      protocol                        must be in /etc/protocols
  *                                      (usually "tcp" or "udp")
  *      wait/nowait[.max]               single-threaded/multi-threaded, max #
  *      user[.group] or user[:group]    user/group to run daemon as
- *      server program                  full path name
- *      server program arguments        maximum of MAXARGS (20)
+ *      server_program                  full path name
+ *      server_program_arguments        maximum of MAXARGS (20)
  *
  * For RPC services
- *      service name/version            must be in /etc/rpc
- *      socket type                     stream/dgram/raw/rdm/seqpacket
+ *      service_name/version            must be in /etc/rpc
+ *      socket_type                     stream/dgram/raw/rdm/seqpacket
  *      rpc/protocol                    "rpc/tcp" etc
  *      wait/nowait[.max]               single-threaded/multi-threaded
  *      user[.group] or user[:group]    user to run daemon as
- *      server program                  full path name
- *      server program arguments        maximum of MAXARGS (20)
+ *      server_program                  full path name
+ *      server_program_arguments        maximum of MAXARGS (20)
  *
  * For non-RPC services, the "service name" can be of the form
  * hostaddress:servicename, in which case the hostaddress is used
  * as the host portion of the address to listen on.  If hostaddress
- * consists of a single `*' character, INADDR_ANY is used.
+ * consists of a single '*' character, INADDR_ANY is used.
  *
  * A line can also consist of just
  *      hostaddress:
  * one line for any given RPC service, even if the host-address
  * specifiers are different.
  *
- * Comment lines are indicated by a `#' in column 1.
+ * Comment lines are indicated by a '#' in column 1.
  */
 
 /* inetd rules for passing file descriptors to children
  * connection requests until a timeout.
  */
 
+/* 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()
  */
+//config:config INETD
+//config:      bool "inetd (18 kb)"
+//config:      default y
+//config:      select FEATURE_SYSLOG
+//config:      help
+//config:      Internet superserver daemon
+//config:
+//config:config FEATURE_INETD_SUPPORT_BUILTIN_ECHO
+//config:      bool "Support echo service on port 7"
+//config:      default y
+//config:      depends on INETD
+//config:      help
+//config:      Internal service which echoes data back.
+//config:      Activated by configuration lines like these:
+//config:              echo stream tcp nowait root internal
+//config:              echo dgram  udp wait   root internal
+//config:
+//config:config FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
+//config:      bool "Support discard service on port 8"
+//config:      default y
+//config:      depends on INETD
+//config:      help
+//config:      Internal service which discards all input.
+//config:      Activated by configuration lines like these:
+//config:              discard stream tcp nowait root internal
+//config:              discard dgram  udp wait   root internal
+//config:
+//config:config FEATURE_INETD_SUPPORT_BUILTIN_TIME
+//config:      bool "Support time service on port 37"
+//config:      default y
+//config:      depends on INETD
+//config:      help
+//config:      Internal service which returns big-endian 32-bit number
+//config:      of seconds passed since 1900-01-01. The number wraps around
+//config:      on overflow.
+//config:      Activated by configuration lines like these:
+//config:              time stream tcp nowait root internal
+//config:              time dgram  udp wait   root internal
+//config:
+//config:config FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
+//config:      bool "Support daytime service on port 13"
+//config:      default y
+//config:      depends on INETD
+//config:      help
+//config:      Internal service which returns human-readable time.
+//config:      Activated by configuration lines like these:
+//config:              daytime stream tcp nowait root internal
+//config:              daytime dgram  udp wait   root internal
+//config:
+//config:config FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
+//config:      bool "Support chargen service on port 19"
+//config:      default y
+//config:      depends on INETD
+//config:      help
+//config:      Internal service which generates endless stream
+//config:      of all ASCII chars beetween space and char 126.
+//config:      Activated by configuration lines like these:
+//config:              chargen stream tcp nowait root internal
+//config:              chargen dgram  udp wait   root internal
+//config:
+//config:config FEATURE_INETD_RPC
+//config:      bool "Support RPC services"
+//config:      default n  # very rarely used, and needs Sun RPC support in libc
+//config:      depends on INETD
+//config:      help
+//config:      Support Sun-RPC based services
+
+//applet:IF_INETD(APPLET(inetd, BB_DIR_USR_SBIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_INETD) += inetd.o
+
+//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)"
+//usage:     "\n       Default CONFFILE is /etc/inetd.conf"
 
 #include <syslog.h>
+#include <sys/resource.h> /* setrlimit */
+#include <sys/socket.h> /* un.h may need this */
 #include <sys/un.h>
+
 #include "libbb.h"
+#include "common_bufsiz.h"
+
+#if ENABLE_FEATURE_INETD_RPC
+# if defined(__UCLIBC__) && ! defined(__UCLIBC_HAS_RPC__)
+#  warning "You probably need to build uClibc with UCLIBC_HAS_RPC for NFS support"
+   /* not #error, since user may be using e.g. libtirpc instead */
+# endif
+# include <rpc/rpc.h>
+# include <rpc/pmap_clnt.h>
+#endif
 
 #if !BB_MMU
-/* stream versions of these builtins are forking,
+/* stream version of chargen is forking but not execing,
  * can't do that (easily) on NOMMU */
-#undef  ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
-#define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD 0
 #undef  ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 #define ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN 0
 #endif
 
-#if ENABLE_FEATURE_INETD_RPC
-#include <rpc/rpc.h>
-#include <rpc/pmap_clnt.h>
-#endif
+#define CNT_INTERVAL    60      /* servers in CNT_INTERVAL sec. */
+#define RETRYTIME       60      /* retry after bind or server fail */
 
-#define _PATH_INETDPID  "/var/run/inetd.pid"
-
-#define CNT_INTERVAL    60              /* servers in CNT_INTERVAL sec. */
-#define RETRYTIME       (60*10)         /* retry after bind or server fail */
+// TODO: explain, or get rid of setrlimit games
 
 #ifndef RLIMIT_NOFILE
 #define RLIMIT_NOFILE   RLIMIT_OFILE
@@ -209,20 +300,21 @@ typedef struct servtab_t {
 #else
 #define is_rpc_service(sep)       0
 #endif
-       pid_t se_wait;                        /* 0:"nowait", 1:"wait" */
+       pid_t se_wait;                        /* 0:"nowait", 1:"wait", >1:"wait" */
+                                             /* and waiting for this pid */
        socktype_t se_socktype;               /* SOCK_STREAM/DGRAM/RDM/... */
        family_t se_family;                   /* AF_UNIX/INET[6] */
-       smallint se_proto_no;                 /* almost "getprotobyname(se_proto)" */
+       /* se_proto_no is used by RPC code only... hmm */
+       smallint se_proto_no;                 /* IPPROTO_TCP/UDP, n/a for AF_UNIX */
        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;                     /* 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
        const struct builtin *se_builtin;     /* if built-in, description */
 #endif
-// TODO: wrong algorithm!!!
-       unsigned se_max;                      /* max # of instances of this service */
-       unsigned se_count;                    /* number started since se_time */
-       unsigned se_time;                     /* start of se_count */
        struct servtab_t *se_next;
        len_and_sockaddr *se_lsa;
        char *se_program;                     /* server program */
@@ -231,60 +323,54 @@ typedef struct servtab_t {
 } servtab_t;
 
 #ifdef INETD_BUILTINS_ENABLED
-               /* Echo received data */
+/* 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 */
+/* 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 */
+/* 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 */
+/* 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 */
+/* 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 {
-       const char *bi_service;         /* internally provided service name */
-       uint8_t bi_fork;                /* 1 if stream fn should run in child */
-       /* All builtins are "nowait" */
-       /* uint8_t bi_wait; */          /* 1 if should wait for child */
-       void (*bi_stream_fn)(int, servtab_t *);
-       void (*bi_dgram_fn)(int, servtab_t *);
+       /* 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 *) FAST_FUNC;
+       void (*bi_dgram_fn)(int, servtab_t *) FAST_FUNC;
 };
 
 static const struct builtin builtins[] = {
 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO
-       /* Echo received data */
        { "echo", 1, echo_stream, echo_dg },
 #endif
 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
-       /* Internet /dev/null */
        { "discard", 1, discard_stream, discard_dg },
 #endif
 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
-       /* Familiar character generator */
        { "chargen", 1, chargen_stream, chargen_dg },
 #endif
 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_TIME
-       /* Return 32 bit time since 1900 */
        { "time", 0, machtime_stream, machtime_dg },
 #endif
 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DAYTIME
-       /* Return human-readable time */
        { "daytime", 0, daytime_stream, daytime_dg },
 #endif
 };
@@ -295,59 +381,74 @@ struct globals {
        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 *endring;
-       char *ringpos;
+       char *end_ring;
+       char *ring_pos;
        char ring[128];
 #endif
        fd_set allsock;
        /* Used in next_line(), and as scratch read buffer */
        char line[256];          /* _at least_ 256, see LINE_SIZE */
-};
-#define G (*(struct globals*)&bb_common_bufsiz1)
+} FIX_ALIASING;
+#define G (*(struct globals*)bb_common_bufsiz1)
 enum { LINE_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line) };
-struct BUG_G_too_big {
-       char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
-};
 #define rlim_ofile_cur  (G.rlim_ofile_cur )
 #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   )
-#define endring         (G.endring        )
-#define ringpos         (G.ringpos        )
+#define end_ring        (G.end_ring       )
+#define ring_pos        (G.ring_pos       )
 #define ring            (G.ring           )
 #define allsock         (G.allsock        )
 #define line            (G.line           )
 #define INIT_G() do { \
+       setup_common_bufsiz(); \
+       BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
        rlim_ofile_cur = OPEN_MAX; \
        global_queuelen = 128; \
        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?
@@ -357,6 +458,8 @@ static len_and_sockaddr *xzalloc_lsa(int family)
        int sz;
 
        sz = sizeof(struct sockaddr_in);
+       if (family == AF_UNIX)
+               sz = sizeof(struct sockaddr_un);
 #if ENABLE_FEATURE_IPV6
        if (family == AF_INET6)
                sz = sizeof(struct sockaddr_in6);
@@ -364,10 +467,9 @@ static len_and_sockaddr *xzalloc_lsa(int family)
        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 (!alarm_armed) {
@@ -382,12 +484,12 @@ static void block_CHLD_HUP_ALRM(sigset_t *m)
        sigaddset(m, SIGCHLD);
        sigaddset(m, SIGHUP);
        sigaddset(m, SIGALRM);
-       sigprocmask(SIG_BLOCK, m, NULL);
+       sigprocmask(SIG_BLOCK, m, m); /* old sigmask is stored in m */
 }
 
-static void unblock_sigs(sigset_t *m)
+static void restore_sigmask(sigset_t *m)
 {
-       sigprocmask(SIG_UNBLOCK, m, NULL);
+       sigprocmask(SIG_SETMASK, m, NULL);
 }
 
 #if ENABLE_FEATURE_INETD_RPC
@@ -450,7 +552,9 @@ static void remove_fd_from_set(int fd)
 {
        if (fd >= 0) {
                FD_CLR(fd, &allsock);
+               dbg("stopped listening on fd:%d\n", fd);
                maxsock = -1;
+               dbg("maxsock:%d\n", maxsock);
        }
 }
 
@@ -458,9 +562,11 @@ static void add_fd_to_set(int fd)
 {
        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();
                }
        }
@@ -469,11 +575,16 @@ static void add_fd_to_set(int fd)
 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();
@@ -496,7 +607,7 @@ static void prepare_socket_fd(servtab_t *sep)
 
                /* 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. */
@@ -531,8 +642,13 @@ static void prepare_socket_fd(servtab_t *sep)
                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;
@@ -542,61 +658,20 @@ static int reopen_config_file(void)
 {
        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;
+       if (parser) {
+               config_close(parser);
+               parser = 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;
-       }
-       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)
 {
        int i;
@@ -645,63 +720,58 @@ static servtab_t *dup_servtab(servtab_t *sep)
 static NOINLINE 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;
+                       /*sep->se_local_hostname = NULL; - redundant */
+                       /* (we'll overwrite this field anyway) */
+                       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);
-               free_servtab_strings(sep);
+                               parser->lineno);
                /* Just "goto more" can make sep to carry over e.g.
                 * "rpc"-ness (by having se_rpcver_lo != 0).
                 * We will be more paranoid: */
+               free_servtab_strings(sep);
                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
@@ -709,13 +779,11 @@ static NOINLINE servtab_t *parse_one_line(void)
                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 {
@@ -731,7 +799,7 @@ static NOINLINE servtab_t *parse_one_line(void)
                        goto parse_err;
 #endif
                }
-               if (strncmp(arg, "rpc/", 4) == 0) {
+               if (is_prefixed_with(arg, "rpc/")) {
 #if ENABLE_FEATURE_INETD_RPC
                        unsigned n;
                        arg += 4;
@@ -751,7 +819,7 @@ static NOINLINE servtab_t *parse_one_line(void)
                        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;
                        }
@@ -764,9 +832,9 @@ static NOINLINE servtab_t *parse_one_line(void)
                }
                /* we don't really need getprotobyname()! */
                if (strcmp(arg, "tcp") == 0)
-                       sep->se_proto_no = 6;
+                       sep->se_proto_no = IPPROTO_TCP; /* = 6 */
                if (strcmp(arg, "udp") == 0)
-                       sep->se_proto_no = 17;
+                       sep->se_proto_no = IPPROTO_UDP; /* = 17 */
                if (six)
                        *six = '6';
                if (!sep->se_proto_no) /* not tcp/udp?? */
@@ -774,9 +842,7 @@ static NOINLINE servtab_t *parse_one_line(void)
        }
 
        /* [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) {
@@ -785,12 +851,14 @@ static NOINLINE servtab_t *parse_one_line(void)
                if (errno)
                        goto parse_err;
        }
-       sep->se_wait = (strcmp(arg, "wait") == 0);
+       sep->se_wait = (arg[0] != 'n' || arg[1] != 'o');
+       if (!sep->se_wait) /* "no" seen */
+               arg += 2;
+       if (strcmp(arg, "wait") != 0)
+               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, ':');
@@ -800,52 +868,66 @@ static NOINLINE servtab_t *parse_one_line(void)
        }
 
        /* 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
-       /* sep->se_builtin = NULL; - done by new_servtab() */
        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 (strcmp(builtins[i].bi_service, sep->se_service) == 0)
+                       if (strncmp(builtins[i].bi_service7, sep->se_service, 7) == 0)
                                goto found_bi;
                bb_error_msg("unknown internal service %s", sep->se_service);
                goto parse_err;
  found_bi:
                sep->se_builtin = &builtins[i];
-               sep->se_wait = 0; /* = builtins[i].bi_wait; - always 0 */
+               /* stream builtins must be "nowait", dgram must be "wait" */
+               if (sep->se_wait != (sep->se_socktype == SOCK_DGRAM))
+                       goto parse_err;
        }
 #endif
        argc = 0;
-       while ((arg = next_word(&cp)) != NULL && argc < MAXARGV) {
+       while (argc < MAXARGV && (arg = token[6+argc]) != NULL)
                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_proto_no == IPPROTO_UDP)
+                       goto parse_err;
+       }
+       if (sep->se_socktype == SOCK_DGRAM) {
+               if (sep->se_proto_no == IPPROTO_TCP)
+                       goto parse_err;
        }
-       /* while (argc <= MAXARGV) */
-       /*      sep->se_argv[argc++] = NULL; - done by new_servtab() */
-
-       /*
-        * Now that we've processed the entire line, check if the hostname
-        * specifier was a comma separated list of hostnames. If so
-        * we'll make new entries for each address.
-        */
+
+       //bb_error_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) {
                nsep = dup_servtab(sep);
-               /*
-                * NUL terminate the hostname field of the existing entry,
-                * and make a dup for the new entry.
-                */
+               /* NUL terminate the hostname field of the existing entry,
+                * and make a dup for the new entry. */
                *hostdelim++ = '\0';
                nsep->se_local_hostname = xstrdup(hostdelim);
                nsep->se_next = sep->se_next;
                sep->se_next = nsep;
        }
 
-       /* Was doing it here: */
+       /* was doing it here: */
        /* DNS resolution, create copies for each IP address */
+       /* IPv6-ization destroyed it :( */
 
        return sep;
 }
@@ -864,7 +946,7 @@ static servtab_t *insert_in_servlist(servtab_t *cp)
        block_CHLD_HUP_ALRM(&omask);
        sep->se_next = serv_list;
        serv_list = sep;
-       unblock_sigs(&omask);
+       restore_sigmask(&omask);
        return sep;
 }
 
@@ -879,16 +961,17 @@ static int same_serv_addr_proto(servtab_t *old, servtab_t *new)
        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;
 
@@ -935,7 +1018,7 @@ static void reread_config_file(int sig ATTRIBUTE_UNUSED)
                        for (i = 0; i < MAXARGV; i++)
                                SWAP(char*, sep->se_argv[i], cp->se_argv[i]);
 #undef SWAP
-                       unblock_sigs(&omask);
+                       restore_sigmask(&omask);
                        free_servtab_strings(cp);
                }
  after_check:
@@ -947,15 +1030,9 @@ static void reread_config_file(int sig ATTRIBUTE_UNUSED)
                switch (sep->se_family) {
                        struct sockaddr_un *sun;
                case AF_UNIX:
-                       /* we have poor infrastructure for AF_UNIX... */
-                       n = strlen(sep->se_service);
-                       if (n > sizeof(sun->sun_path) - 1)
-                               n = sizeof(sun->sun_path) - 1;
-                       lsa = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_un));
-                       lsa->len = sizeof(struct sockaddr_un);
+                       lsa = xzalloc_lsa(AF_UNIX);
                        sun = (struct sockaddr_un*)&lsa->u.sa;
-                       sun->sun_family = AF_UNIX;
-                       strncpy(sun->sun_path, sep->se_service, n);
+                       safe_strncpy(sun->sun_path, sep->se_service, sizeof(sun->sun_path));
                        break;
 
                default: /* case AF_INET, case AF_INET6 */
@@ -995,7 +1072,7 @@ static void reread_config_file(int sig ATTRIBUTE_UNUSED)
                        }
                        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);
@@ -1035,7 +1112,7 @@ static void reread_config_file(int sig ATTRIBUTE_UNUSED)
         * 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;
@@ -1052,10 +1129,12 @@ static void reread_config_file(int sig ATTRIBUTE_UNUSED)
                free_servtab_strings(sep);
                free(sep);
        }
-       unblock_sigs(&omask);
+       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;
@@ -1066,24 +1145,27 @@ static void reap_child(int sig ATTRIBUTE_UNUSED)
                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;
@@ -1096,9 +1178,10 @@ static void retry_network_setup(int sig ATTRIBUTE_UNUSED)
 #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;
 
@@ -1121,12 +1204,12 @@ static void clean_up_and_exit(int sig ATTRIBUTE_UNUSED)
                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;
@@ -1142,8 +1225,8 @@ int inetd_main(int argc, char **argv)
        if (real_uid != 0) /* run by non-root user */
                config_filename = NULL;
 
-       opt_complementary = "R+:q+"; /* -q N, -R N */
-       opt = getopt32(argv, "R:feq:", &max_concurrency, &global_queuelen);
+       /* -q N, -R N */
+       opt = getopt32(argv, "R:+feq:+", &max_concurrency, &global_queuelen);
        argv += optind;
        //argc -= optind;
        if (argv[0])
@@ -1155,7 +1238,12 @@ int inetd_main(int argc, char **argv)
        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;
        }
 
@@ -1165,7 +1253,7 @@ int inetd_main(int argc, char **argv)
                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);
@@ -1178,16 +1266,21 @@ int inetd_main(int argc, char **argv)
        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(SIGALRM, &sa, NULL);
+       sigaction_set(SIGALRM, &sa);
+//FIXME: reread_config_file is unsafe to run in signal handler(many reasons)!
        sa.sa_handler = reread_config_file;
-       sigaction(SIGHUP, &sa, NULL);
+       sigaction_set(SIGHUP, &sa);
+//FIXME: reap_child is unsafe to run in signal handler (uses stdio)!
        sa.sa_handler = reap_child;
-       sigaction(SIGCHLD, &sa, NULL);
+       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(SIGTERM, &sa, NULL);
+       sigaction_set(SIGTERM, &sa);
        sa.sa_handler = clean_up_and_exit;
-       sigaction(SIGINT, &sa, NULL);
+       sigaction_set(SIGINT, &sa);
        sa.sa_handler = SIG_IGN;
        sigaction(SIGPIPE, &sa, &saved_pipe_handler);
 
@@ -1195,7 +1288,7 @@ int inetd_main(int argc, char **argv)
 
        for (;;) {
                int ready_fd_cnt;
-               int ctrl, accepted_fd;
+               int ctrl, accepted_fd, new_udp_fd;
                fd_set readable;
 
                if (maxsock < 0)
@@ -1203,7 +1296,8 @@ int inetd_main(int argc, char **argv)
 
                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) {
@@ -1212,20 +1306,57 @@ int inetd_main(int argc, char **argv)
                        }
                        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");
                                }
                        }
 
@@ -1252,15 +1383,16 @@ int inetd_main(int argc, char **argv)
                                                        sep->se_fd = -1;
                                                        sep->se_count = 0;
                                                        rearm_alarm(); /* will revive it in RETRYTIME sec */
-                                                       unblock_sigs(&omask);
+                                                       restore_sigmask(&omask);
+                                                       maybe_close(new_udp_fd);
                                                        maybe_close(accepted_fd);
                                                        continue; /* -> check next fd in fd set */
                                                }
                                                sep->se_count = 0;
                                        }
                                }
-                               /* on NOMMU, streamed echo, chargen and discard
-                                * builtins wouldn't work, but they are
+                               /* on NOMMU, streamed chargen
+                                * builtin wouldn't work, but it is
                                 * not allowed on NOMMU (ifdefed out) */
 #ifdef INETD_BUILTINS_ENABLED
                                if (BB_MMU && sep->se_builtin)
@@ -1270,25 +1402,32 @@ int inetd_main(int argc, char **argv)
                                        pid = vfork();
 
                                if (pid < 0) { /* fork error */
-                                       bb_perror_msg("fork");
+                                       bb_perror_msg("vfork"+1);
                                        sleep(1);
-                                       unblock_sigs(&omask);
+                                       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 */
                                }
-                               unblock_sigs(&omask);
+                               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);
                                continue; /* -> check next fd in fd set */
                        }
@@ -1298,28 +1437,50 @@ int inetd_main(int argc, char **argv)
                        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 */
                                }
-                               unblock_sigs(&omask);
+                               restore_sigmask(&omask);
                                if (sep->se_socktype == SOCK_STREAM)
                                        sep->se_builtin->bi_stream_fn(ctrl, sep);
                                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. prepare env and exec program */
+                       /* child */
                        setsid();
+                       /* "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 */
+                               r = recvfrom(ctrl, NULL, 0, MSG_PEEK|MSG_DONTWAIT,
+                                       &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);
+                       }
+                       /* 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) {
@@ -1327,12 +1488,11 @@ int inetd_main(int argc, char **argv)
                                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);
@@ -1340,49 +1500,73 @@ int inetd_main(int argc, char **argv)
                        if (rlim_ofile.rlim_cur != rlim_ofile_cur)
                                if (setrlimit(RLIMIT_NOFILE, &rlim_ofile) < 0)
                                        bb_perror_msg("setrlimit");
-                       closelog();
-                       xmove_fd(ctrl, 0);
-                       dup2(0, 1);
-                       dup2(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);
-                       sigaction(SIGPIPE, &saved_pipe_handler, NULL);
-                       unblock_sigs(&omask);
+                               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 ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_ECHO \
+ || ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_DISCARD
+# if !BB_MMU
+static const char *const cat_args[] = { "cat", NULL };
+# endif
+#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
+# if BB_MMU
        while (1) {
                ssize_t sz = safe_read(s, line, LINE_SIZE);
                if (sz <= 0)
                        break;
                xwrite(s, line, sz);
        }
-#else
-       static const char *const args[] = { "cat", NULL };
-       BB_EXECVP("cat", (char**)args);
-       _exit(1);
-#endif
+# else
+       /* 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 */
@@ -1400,15 +1584,28 @@ static void echo_dg(int s, servtab_t *sep)
 
 
 #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
+       /* 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);
@@ -1418,25 +1615,24 @@ static void discard_dg(int s, servtab_t *sep ATTRIBUTE_UNUSED)
 
 #if ENABLE_FEATURE_INETD_SUPPORT_BUILTIN_CHARGEN
 #define LINESIZ 72
-static void initring(void)
+static void init_ring(void)
 {
        int i;
 
-       endring = ring;
-       for (i = 0; i <= 128; ++i)
-               if (isprint(i))
-                       *endring++ = i;
+       end_ring = ring;
+       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;
        char text[LINESIZ + 2];
 
-       if (!endring) {
-               initring();
+       if (!end_ring) {
+               init_ring();
                rs = ring;
        }
 
@@ -1444,20 +1640,20 @@ static void chargen_stream(int s, servtab_t *sep)
        text[LINESIZ + 1] = '\n';
        rs = ring;
        for (;;) {
-               len = endring - rs;
+               len = end_ring - rs;
                if (len >= LINESIZ)
                        memmove(text, rs, LINESIZ);
                else {
                        memmove(text, rs, len);
                        memmove(text + len, ring, LINESIZ - len);
                }
-               if (++rs == endring)
+               if (++rs == end_ring)
                        rs = ring;
                xwrite(s, text, sizeof(text));
        }
 }
 /* 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];
@@ -1469,20 +1665,20 @@ static void chargen_dg(int s, servtab_t *sep)
        if (recvfrom(s, text, sizeof(text), MSG_DONTWAIT, &lsa->u.sa, &lsa->len) < 0)
                return;
 
-       if (!endring) {
-               initring();
-               ringpos = ring;
+       if (!end_ring) {
+               init_ring();
+               ring_pos = ring;
        }
 
-       len = endring - ringpos;
+       len = end_ring - ring_pos;
        if (len >= LINESIZ)
-               memmove(text, ringpos, LINESIZ);
+               memmove(text, ring_pos, LINESIZ);
        else {
-               memmove(text, ringpos, len);
+               memmove(text, ring_pos, len);
                memmove(text + len, ring, LINESIZ - len);
        }
-       if (++ringpos == endring)
-               ringpos = ring;
+       if (++ring_pos == end_ring)
+               ring_pos = ring;
        text[LINESIZ] = '\r';
        text[LINESIZ + 1] = '\n';
        sendto(s, text, sizeof(text), 0, &lsa->u.sa, lsa->len);
@@ -1498,22 +1694,22 @@ static void chargen_dg(int s, servtab_t *sep)
  * we must add 2208988800 seconds to this figure to make up for
  * some seventy years Bell Labs was asleep.
  */
-static unsigned machtime(void)
+static uint32_t machtime(void)
 {
        struct timeval tv;
 
        gettimeofday(&tv, NULL);
-       return htonl((uint32_t)(tv.tv_sec + 2208988800));
+       return htonl((uint32_t)(tv.tv_sec + 2208988800U));
 }
 /* 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);
@@ -1531,14 +1727,14 @@ static void machtime_dg(int s, servtab_t *sep)
 #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);
+       time(&t);
        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);