svn add/svn rm to actually move tcp/udpsvd...

5 files changed, 0 insertions, 731 deletions

diff --git a/ipsvd/Config.in b/ipsvd/Config.in
deleted file mode 100644
index 0cb8c62..0000000
--- a/ipsvd/Config.in
+++ /dev/null
@@ -1,20 +0,0 @@
-#
-# For a description of the syntax of this configuration file,
-# see scripts/kbuild/config-language.txt.
-#
-
-menu "ipsvd Utilities"
-
-config TCPSVD
-	bool "tcpsvd"
-	default n
-	help
-	  tcpsvd listens on a tcp port and runs a program for each new connection
-
-config UDPSVD
-	bool "udpsvd"
-	default n
-	help
-	  udpsvd listens on a udp port and runs a program for each new connection
-
-endmenu
diff --git a/ipsvd/Kbuild b/ipsvd/Kbuild
deleted file mode 100644
index fc34fea..0000000
--- a/ipsvd/Kbuild
+++ /dev/null
@@ -1,9 +0,0 @@
-# Makefile for busybox
-#
-# Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
-#
-# Licensed under the GPL v2, see the file LICENSE in this tarball.
-
-lib-y:=
-lib-$(CONFIG_TCPSVD) += tcpudp.o ipsvd_perhost.o
-lib-$(CONFIG_UDPSVD) += tcpudp.o ipsvd_perhost.o
diff --git a/ipsvd/ipsvd_perhost.c b/ipsvd/ipsvd_perhost.c
deleted file mode 100644
index 6075c0a..0000000
--- a/ipsvd/ipsvd_perhost.c
+++ /dev/null
@@ -1,65 +0,0 @@
-/* Based on ipsvd utilities written by Gerrit Pape <pape@smarden.org>
- * which are released into public domain by the author.
- * Homepage: http://smarden.sunsite.dk/ipsvd/
- *
- * Copyright (C) 2007 Denys Vlasenko.
- *
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
- */
-
-#include "libbb.h"
-#include "ipsvd_perhost.h"
-
-static struct hcc *cc;
-static unsigned cclen;
-
-/* to be optimized */
-
-void ipsvd_perhost_init(unsigned c)
-{
-//	free(cc);
-	cc = xzalloc(c * sizeof(*cc));
-	cclen = c;
-}
-
-unsigned ipsvd_perhost_add(char *ip, unsigned maxconn, struct hcc **hccpp)
-{
-	unsigned i;
-	unsigned conn = 1;
-	int freepos = -1;
-
-	for (i = 0; i < cclen; ++i) {
-		if (!cc[i].ip) {
-			freepos = i;
-			continue;
-		}
-		if (strcmp(cc[i].ip, ip) == 0) {
-			conn++;
-			continue;
-		}
-	}
-	if (freepos == -1) return 0;
-	if (conn <= maxconn) {
-		cc[freepos].ip = ip;
-		*hccpp = &cc[freepos];
-	}
-	return conn;
-}
-
-void ipsvd_perhost_remove(int pid)
-{
-	unsigned i;
-	for (i = 0; i < cclen; ++i) {
-		if (cc[i].pid == pid) {
-			free(cc[i].ip);
-			cc[i].ip = NULL;
-			cc[i].pid = 0;
-			return;
-		}
-	}
-}
-
-//void ipsvd_perhost_free(void)
-//{
-//	free(cc);
-//}
diff --git a/ipsvd/ipsvd_perhost.h b/ipsvd/ipsvd_perhost.h
deleted file mode 100644
index 9fc8cee..0000000
--- a/ipsvd/ipsvd_perhost.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/* Based on ipsvd utilities written by Gerrit Pape <pape@smarden.org>
- * which are released into public domain by the author.
- * Homepage: http://smarden.sunsite.dk/ipsvd/
- *
- * Copyright (C) 2007 Denys Vlasenko.
- *
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
- */
-
-struct hcc {
-	char *ip;
-	int pid;
-};
-
-void ipsvd_perhost_init(unsigned);
-
-/* Returns number of already opened connects to this ips, including this one.
- * ip should be a malloc'ed ptr.
- * If return value is <= maxconn, ip is inserted into the table
- * and pointer to table entry if stored in *hccpp
- * (useful for storing pid later).
- * Else ip is NOT inserted (you must take care of it - free() etc) */
-unsigned ipsvd_perhost_add(char *ip, unsigned maxconn, struct hcc **hccpp);
-
-/* Finds and frees element with pid */
-void ipsvd_perhost_remove(int pid);
-
-//unsigned ipsvd_perhost_setpid(int pid);
-//void ipsvd_perhost_free(void);
diff --git a/ipsvd/tcpudp.c b/ipsvd/tcpudp.c
deleted file mode 100644
index 729b7bc..0000000
--- a/ipsvd/tcpudp.c
+++ /dev/null
@@ -1,608 +0,0 @@
-/* Based on ipsvd utilities written by Gerrit Pape <pape@smarden.org>
- * which are released into public domain by the author.
- * Homepage: http://smarden.sunsite.dk/ipsvd/
- *
- * Copyright (C) 2007 Denys Vlasenko.
- *
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
- */
-
-/* Based on ipsvd ipsvd-0.12.1. This tcpsvd accepts all options
- * which are supported by one from ipsvd-0.12.1, but not all are
- * functional. See help text at the end of this file for details.
- *
- * Code inside "#ifdef SSLSVD" is for sslsvd and is currently unused.
- *
- * Busybox version exports TCPLOCALADDR instead of
- * TCPLOCALIP + TCPLOCALPORT pair. ADDR more closely matches reality
- * (which is "struct sockaddr_XXX". Port is not a separate entity,
- * it's just a part of (AF_INET[6]) sockaddr!).
- *
- * TCPORIGDSTADDR is Busybox-specific addition.
- *
- * udp server is hacked up by reusing TCP code. It has the following
- * limitation inherent in Unix DGRAM sockets implementation:
- * - local IP address is retrieved (using recvmsg voodoo) but
- *   child's socket is not bound to it (bind cannot be called on
- *   already bound socket). Thus it still can emit outgoing packets
- *   with wrong source IP...
- * - don't know how to retrieve ORIGDST for udp.
- */
-
-#include <limits.h>
-#include <linux/netfilter_ipv4.h> /* wants <limits.h> */
-
-#include "libbb.h"
-#include "ipsvd_perhost.h"
-
-#ifdef SSLSVD
-#include "matrixSsl.h"
-#include "ssl_io.h"
-#endif
-
-struct globals {
-	unsigned verbose;
-	unsigned max_per_host;
-	unsigned cur_per_host;
-	unsigned cnum;
-	unsigned cmax;
-	char **env_cur;
-	char *env_var[1]; /* actually bigger */
-};
-#define G (*(struct globals*)&bb_common_bufsiz1)
-#define verbose      (G.verbose     )
-#define max_per_host (G.max_per_host)
-#define cur_per_host (G.cur_per_host)
-#define cnum         (G.cnum        )
-#define cmax         (G.cmax        )
-#define env_cur      (G.env_cur     )
-#define env_var      (G.env_var     )
-#define INIT_G() \
-	do { \
-		cmax = 30; \
-		env_cur = &env_var[0]; \
-	} while (0)
-
-
-/* We have to be careful about leaking memory in repeated setenv's */
-static void xsetenv_plain(const char *n, const char *v)
-{
-	char *var = xasprintf("%s=%s", n, v);
-	*env_cur++ = var;
-	putenv(var);
-}
-
-static void xsetenv_proto(const char *proto, const char *n, const char *v)
-{
-	char *var = xasprintf("%s%s=%s", proto, n, v);
-	*env_cur++ = var;
-	putenv(var);
-}
-
-static void undo_xsetenv(void)
-{
-	char **pp = env_cur = &env_var[0];
-	while (*pp) {
-		char *var = *pp;
-		*strchrnul(var, '=') = '\0';
-		unsetenv(var);
-		free(var);
-		*pp++ = NULL;
-	}
-}
-
-static void sig_term_handler(int sig)
-{
-	if (verbose)
-		bb_error_msg("got signal %u, exit", sig);
-	kill_myself_with_sig(sig);
-}
-
-/* Little bloated, but tries to give accurate info how child exited.
- * Makes easier to spot segfaulting children etc... */
-static void print_waitstat(unsigned pid, int wstat)
-{
-	unsigned e = 0;
-	const char *cause = "?exit";
-
-	if (WIFEXITED(wstat)) {
-		cause++;
-		e = WEXITSTATUS(wstat);
-	} else if (WIFSIGNALED(wstat)) {
-		cause = "signal";
-		e = WTERMSIG(wstat);
-	}
-	bb_error_msg("end %d %s %d", pid, cause, e);
-}
-
-/* Must match getopt32 in main! */
-enum {
-	OPT_c = (1 << 0),
-	OPT_C = (1 << 1),
-	OPT_i = (1 << 2),
-	OPT_x = (1 << 3),
-	OPT_u = (1 << 4),
-	OPT_l = (1 << 5),
-	OPT_E = (1 << 6),
-	OPT_b = (1 << 7),
-	OPT_h = (1 << 8),
-	OPT_p = (1 << 9),
-	OPT_t = (1 << 10),
-	OPT_v = (1 << 11),
-	OPT_V = (1 << 12),
-	OPT_U = (1 << 13), /* from here: sslsvd only */
-	OPT_slash = (1 << 14),
-	OPT_Z = (1 << 15),
-	OPT_K = (1 << 16),
-};
-
-static void connection_status(void)
-{
-	/* "only 1 client max" desn't need this */
-	if (cmax > 1)
-		bb_error_msg("status %u/%u", cnum, cmax);
-}
-
-static void sig_child_handler(int sig ATTRIBUTE_UNUSED)
-{
-	int wstat;
-	int pid;
-
-	while ((pid = wait_any_nohang(&wstat)) > 0) {
-		if (max_per_host)
-			ipsvd_perhost_remove(pid);
-		if (cnum)
-			cnum--;
-		if (verbose)
-			print_waitstat(pid, wstat);
-	}
-	if (verbose)
-		connection_status();
-}
-
-int tcpudpsvd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int tcpudpsvd_main(int argc ATTRIBUTE_UNUSED, char **argv)
-{
-	char *str_C, *str_t;
-	char *user;
-	struct hcc *hccp;
-	const char *instructs;
-	char *msg_per_host = NULL;
-	unsigned len_per_host = len_per_host; /* gcc */
-#ifndef SSLSVD
-	struct bb_uidgid_t ugid;
-#endif
-	bool tcp;
-	uint16_t local_port;
-	char *preset_local_hostname = NULL;
-	char *remote_hostname = remote_hostname; /* for compiler */
-	char *remote_addr = remote_addr; /* for compiler */
-	len_and_sockaddr *lsa;
-	len_and_sockaddr local, remote;
-	socklen_t sa_len;
-	int pid;
-	int sock;
-	int conn;
-	unsigned backlog = 20;
-
-	INIT_G();
-
-	tcp = (applet_name[0] == 't');
-
-	/* 3+ args, -i at most once, -p implies -h, -v is counter, -b N, -c N */
-	opt_complementary = "-3:i--i:ph:vv:b+:c+";
-#ifdef SSLSVD
-	getopt32(argv, "+c:C:i:x:u:l:Eb:hpt:vU:/:Z:K:",
-		&cmax, &str_C, &instructs, &instructs, &user, &preset_local_hostname,
-		&backlog, &str_t, &ssluser, &root, &cert, &key, &verbose
-	);
-#else
-	/* "+": stop on first non-option */
-	getopt32(argv, "+c:C:i:x:u:l:Eb:hpt:v",
-		&cmax, &str_C, &instructs, &instructs, &user, &preset_local_hostname,
-		&backlog, &str_t, &verbose
-	);
-#endif
-	if (option_mask32 & OPT_C) { /* -C n[:message] */
-		max_per_host = bb_strtou(str_C, &str_C, 10);
-		if (str_C[0]) {
-			if (str_C[0] != ':')
-				bb_show_usage();
-			msg_per_host = str_C + 1;
-			len_per_host = strlen(msg_per_host);
-		}
-	}
-	if (max_per_host > cmax)
-		max_per_host = cmax;
-	if (option_mask32 & OPT_u) {
-		if (!get_uidgid(&ugid, user, 1))
-			bb_error_msg_and_die("unknown user/group: %s", user);
-	}
-#ifdef SSLSVD
-	if (option_mask32 & OPT_U) ssluser = optarg;
-	if (option_mask32 & OPT_slash) root = optarg;
-	if (option_mask32 & OPT_Z) cert = optarg;
-	if (option_mask32 & OPT_K) key = optarg;
-#endif
-	argv += optind;
-	if (!argv[0][0] || LONE_CHAR(argv[0], '0'))
-		argv[0] = (char*)"0.0.0.0";
-
-	/* Per-IP flood protection is not thought-out for UDP */
-	if (!tcp)
-		max_per_host = 0;
-
-	bb_sanitize_stdio(); /* fd# 0,1,2 must be opened */
-
-#ifdef SSLSVD
-	sslser = user;
-	client = 0;
-	if ((getuid() == 0) && !(option_mask32 & OPT_u)) {
-		xfunc_exitcode = 100;
-		bb_error_msg_and_die("-U ssluser must be set when running as root");
-	}
-	if (option_mask32 & OPT_u)
-		if (!uidgid_get(&sslugid, ssluser, 1)) {
-			if (errno) {
-				bb_perror_msg_and_die("fatal: cannot get user/group: %s", ssluser);
-			}
-			bb_error_msg_and_die("unknown user/group '%s'", ssluser);
-		}
-	if (!cert) cert = "./cert.pem";
-	if (!key) key = cert;
-	if (matrixSslOpen() < 0)
-		fatal("cannot initialize ssl");
-	if (matrixSslReadKeys(&keys, cert, key, 0, ca) < 0) {
-		if (client)
-			fatal("cannot read cert, key, or ca file");
-		fatal("cannot read cert or key file");
-	}
-	if (matrixSslNewSession(&ssl, keys, 0, SSL_FLAGS_SERVER) < 0)
-		fatal("cannot create ssl session");
-#endif
-
-	sig_block(SIGCHLD);
-	signal(SIGCHLD, sig_child_handler);
-	bb_signals(BB_SIGS_FATAL, sig_term_handler);
-	signal(SIGPIPE, SIG_IGN);
-
-	if (max_per_host)
-		ipsvd_perhost_init(cmax);
-
-	local_port = bb_lookup_port(argv[1], tcp ? "tcp" : "udp", 0);
-	lsa = xhost2sockaddr(argv[0], local_port);
-	argv += 2;
-
-	sock = xsocket(lsa->u.sa.sa_family, tcp ? SOCK_STREAM : SOCK_DGRAM, 0);
-	setsockopt_reuseaddr(sock);
-	sa_len = lsa->len; /* I presume sockaddr len stays the same */
-	xbind(sock, &lsa->u.sa, sa_len);
-	if (tcp)
-		xlisten(sock, backlog);
-	else /* udp: needed for recv_from_to to work: */
-		socket_want_pktinfo(sock);
-	/* ndelay_off(sock); - it is the default I think? */
-
-#ifndef SSLSVD
-	if (option_mask32 & OPT_u) {
-		/* drop permissions */
-		xsetgid(ugid.gid);
-		xsetuid(ugid.uid);
-	}
-#endif
-
-	if (verbose) {
-		char *addr = xmalloc_sockaddr2dotted(&lsa->u.sa);
-		bb_error_msg("listening on %s, starting", addr);
-		free(addr);
-#ifndef SSLSVD
-		if (option_mask32 & OPT_u)
-			printf(", uid %u, gid %u",
-				(unsigned)ugid.uid, (unsigned)ugid.gid);
-#endif
-	}
-
-	/* Main accept() loop */
-
- again:
-	hccp = NULL;
-
-	while (cnum >= cmax)
-		wait_for_any_sig(); /* expecting SIGCHLD */
-
-	/* Accept a connection to fd #0 */
- again1:
-	close(0);
- again2:
-	sig_unblock(SIGCHLD);
-	local.len = remote.len = sa_len;
-	if (tcp) {
-		conn = accept(sock, &remote.u.sa, &remote.len);
-	} else {
-		/* In case recv_from_to won't be able to recover local addr.
-		 * Also sets port - recv_from_to is unable to do it. */
-		local = *lsa;
-		conn = recv_from_to(sock, NULL, 0, MSG_PEEK,
-				&remote.u.sa, &local.u.sa, sa_len);
-	}
-	sig_block(SIGCHLD);
-	if (conn < 0) {
-		if (errno != EINTR)
-			bb_perror_msg(tcp ? "accept" : "recv");
-		goto again2;
-	}
-	xmove_fd(tcp ? conn : sock, 0);
-
-	if (max_per_host) {
-		/* Drop connection immediately if cur_per_host > max_per_host
-		 * (minimizing load under SYN flood) */
-		remote_addr = xmalloc_sockaddr2dotted_noport(&remote.u.sa);
-		cur_per_host = ipsvd_perhost_add(remote_addr, max_per_host, &hccp);
-		if (cur_per_host > max_per_host) {
-			/* ipsvd_perhost_add detected that max is exceeded
-			 * (and did not store ip in connection table) */
-			free(remote_addr);
-			if (msg_per_host) {
-				/* don't block or test for errors */
-				send(0, msg_per_host, len_per_host, MSG_DONTWAIT);
-			}
-			goto again1;
-		}
-		/* NB: remote_addr is not leaked, it is stored in conn table */
-	}
-
-	if (!tcp) {
-		/* Voodoo magic: making udp sockets each receive its own
-		 * packets is not trivial, and I still not sure
-		 * I do it 100% right.
-		 * 1) we have to do it before fork()
-		 * 2) order is important - is it right now? */
-
-		/* Open new non-connected UDP socket for further clients... */
-		sock = xsocket(lsa->u.sa.sa_family, SOCK_DGRAM, 0);
-		setsockopt_reuseaddr(sock);
-		/* Make plain write/send work for old socket by supplying default
-		 * destination address. This also restricts incoming packets
-		 * to ones coming from this remote IP. */
-		xconnect(0, &remote.u.sa, sa_len);
-	/* hole? at this point we have no wildcard udp socket...
-	 * can this cause clients to get "port unreachable" icmp?
-	 * Yup, time window is very small, but it exists (is it?) */
-		/* ..."open new socket", continued */
-		xbind(sock, &lsa->u.sa, sa_len);
-		socket_want_pktinfo(sock);
-
-		/* Doesn't work:
-		 * we cannot replace fd #0 - we will lose pending packet
-		 * which is already buffered for us! And we cannot use fd #1
-		 * instead - it will "intercept" all following packets, but child
-		 * does not expect data coming *from fd #1*! */
-#if 0
-		/* Make it so that local addr is fixed to localp->u.sa
-		 * and we don't accidentally accept packets to other local IPs. */
-		/* NB: we possibly bind to the _very_ same_ address & port as the one
-		 * already bound in parent! This seems to work in Linux.
-		 * (otherwise we can move socket to fd #0 only if bind succeeds) */
-		close(0);
-		set_nport(localp, htons(local_port));
-		xmove_fd(xsocket(localp->u.sa.sa_family, SOCK_DGRAM, 0), 0);
-		setsockopt_reuseaddr(0); /* crucial */
-		xbind(0, &localp->u.sa, localp->len);
-#endif
-	}
-
-	pid = vfork();
-	if (pid == -1) {
-		bb_perror_msg("vfork");
-		goto again;
-	}
-
-	if (pid != 0) {
-		/* Parent */
-		cnum++;
-		if (verbose)
-			connection_status();
-		if (hccp)
-			hccp->pid = pid;
-		/* clean up changes done by vforked child */
-		undo_xsetenv();
-		goto again;
-	}
-
-	/* Child: prepare env, log, and exec prog */
-
-	/* Closing tcp listening socket */
-	if (tcp)
-		close(sock);
-
-	{ /* vfork alert! every xmalloc in this block should be freed! */
-		char *local_hostname = local_hostname; /* for compiler */
-		char *local_addr = NULL;
-		char *free_me0 = NULL;
-		char *free_me1 = NULL;
-		char *free_me2 = NULL;
-
-		if (verbose || !(option_mask32 & OPT_E)) {
-			if (!max_per_host) /* remote_addr is not yet known */
-				free_me0 = remote_addr = xmalloc_sockaddr2dotted(&remote.u.sa);
-			if (option_mask32 & OPT_h) {
-				free_me1 = remote_hostname = xmalloc_sockaddr2host_noport(&remote.u.sa);
-				if (!remote_hostname) {
-					bb_error_msg("cannot look up hostname for %s", remote_addr);
-					remote_hostname = remote_addr;
-				}
-			}
-			/* Find out local IP peer connected to.
-			 * Errors ignored (I'm not paranoid enough to imagine kernel
-			 * which doesn't know local IP). */
-			if (tcp)
-				getsockname(0, &local.u.sa, &local.len);
-			/* else: for UDP it is done earlier by parent */
-			local_addr = xmalloc_sockaddr2dotted(&local.u.sa);
-			if (option_mask32 & OPT_h) {
-				local_hostname = preset_local_hostname;
-				if (!local_hostname) {
-					free_me2 = local_hostname = xmalloc_sockaddr2host_noport(&local.u.sa);
-					if (!local_hostname)
-						bb_error_msg_and_die("cannot look up hostname for %s", local_addr);
-				}
-				/* else: local_hostname is not NULL, but is NOT malloced! */
-			}
-		}
-		if (verbose) {
-			pid = getpid();
-			if (max_per_host) {
-				bb_error_msg("concurrency %s %u/%u",
-					remote_addr,
-					cur_per_host, max_per_host);
-			}
-			bb_error_msg((option_mask32 & OPT_h)
-				? "start %u %s-%s (%s-%s)"
-				: "start %u %s-%s",
-				pid,
-				local_addr, remote_addr,
-				local_hostname, remote_hostname);
-		}
-
-		if (!(option_mask32 & OPT_E)) {
-			/* setup ucspi env */
-			const char *proto = tcp ? "TCP" : "UDP";
-
-			/* Extract "original" destination addr:port
-			 * from Linux firewall. Useful when you redirect
-			 * an outbond connection to local handler, and it needs
-			 * to know where it originally tried to connect */
-			if (tcp && getsockopt(0, SOL_IP, SO_ORIGINAL_DST, &local.u.sa, &local.len) == 0) {
-				char *addr = xmalloc_sockaddr2dotted(&local.u.sa);
-				xsetenv_plain("TCPORIGDSTADDR", addr);
-				free(addr);
-			}
-			xsetenv_plain("PROTO", proto);
-			xsetenv_proto(proto, "LOCALADDR", local_addr);
-			xsetenv_proto(proto, "REMOTEADDR", remote_addr);
-			if (option_mask32 & OPT_h) {
-				xsetenv_proto(proto, "LOCALHOST", local_hostname);
-				xsetenv_proto(proto, "REMOTEHOST", remote_hostname);
-			}
-			//compat? xsetenv_proto(proto, "REMOTEINFO", "");
-			/* additional */
-			if (cur_per_host > 0) /* can not be true for udp */
-				xsetenv_plain("TCPCONCURRENCY", utoa(cur_per_host));
-		}
-		free(local_addr);
-		free(free_me0);
-		free(free_me1);
-		free(free_me2);
-	}
-
-	xdup2(0, 1);
-
-	signal(SIGTERM, SIG_DFL);
-	signal(SIGPIPE, SIG_DFL);
-	signal(SIGCHLD, SIG_DFL);
-	sig_unblock(SIGCHLD);
-
-#ifdef SSLSVD
-	strcpy(id, utoa(pid));
-	ssl_io(0, argv);
-#else
-	BB_EXECVP(argv[0], argv);
-#endif
-	bb_perror_msg_and_die("exec '%s'", argv[0]);
-}
-
-/*
-tcpsvd [-hpEvv] [-c n] [-C n:msg] [-b n] [-u user] [-l name]
-	[-i dir|-x cdb] [ -t sec] host port prog
-
-tcpsvd creates a TCP/IP socket, binds it to the address host:port,
-and listens on the socket for incoming connections.
-
-On each incoming connection, tcpsvd conditionally runs a program,
-with standard input reading from the socket, and standard output
-writing to the socket, to handle this connection. tcpsvd keeps
-listening on the socket for new connections, and can handle
-multiple connections simultaneously.
-
-tcpsvd optionally checks for special instructions depending
-on the IP address or hostname of the client that initiated
-the connection, see ipsvd-instruct(5).
-
-host
-    host either is a hostname, or a dotted-decimal IP address,
-    or 0. If host is 0, tcpsvd accepts connections to any local
-    IP address.
-    * busybox accepts IPv6 addresses and host:port pairs too
-      In this case second parameter is ignored
-port
-    tcpsvd accepts connections to host:port. port may be a name
-    from /etc/services or a number.
-prog
-    prog consists of one or more arguments. For each connection,
-    tcpsvd normally runs prog, with file descriptor 0 reading from
-    the network, and file descriptor 1 writing to the network.
-    By default it also sets up TCP-related environment variables,
-    see tcp-environ(5)
--i dir
-    read instructions for handling new connections from the instructions
-    directory dir. See ipsvd-instruct(5) for details.
-    * ignored by busyboxed version
--x cdb
-    read instructions for handling new connections from the constant database
-    cdb. The constant database normally is created from an instructions
-    directory by running ipsvd-cdb(8).
-    * ignored by busyboxed version
--t sec
-    timeout. This option only takes effect if the -i option is given.
-    While checking the instructions directory, check the time of last access
-    of the file that matches the clients address or hostname if any, discard
-    and remove the file if it wasn't accessed within the last sec seconds;
-    tcpsvd does not discard or remove a file if the user's write permission
-    is not set, for those files the timeout is disabled. Default is 0,
-    which means that the timeout is disabled.
-    * ignored by busyboxed version
--l name
-    local hostname. Do not look up the local hostname in DNS, but use name
-    as hostname. This option must be set if tcpsvd listens on port 53
-    to avoid loops.
--u user[:group]
-    drop permissions. Switch user ID to user's UID, and group ID to user's
-    primary GID after creating and binding to the socket. If user is followed
-    by a colon and a group name, the group ID is switched to the GID of group
-    instead. All supplementary groups are removed.
--c n
-    concurrency. Handle up to n connections simultaneously. Default is 30.
-    If there are n connections active, tcpsvd defers acceptance of a new
-    connection until an active connection is closed.
--C n[:msg]
-    per host concurrency. Allow only up to n connections from the same IP
-    address simultaneously. If there are n active connections from one IP
-    address, new incoming connections from this IP address are closed
-    immediately. If n is followed by :msg, the message msg is written
-    to the client if possible, before closing the connection. By default
-    msg is empty. See ipsvd-instruct(5) for supported escape sequences in msg.
-
-    For each accepted connection, the current per host concurrency is
-    available through the environment variable TCPCONCURRENCY. n and msg
-    can be overwritten by ipsvd(7) instructions, see ipsvd-instruct(5).
-    By default tcpsvd doesn't keep track of connections.
--h
-    Look up the client's hostname in DNS.
--p
-    paranoid. After looking up the client's hostname in DNS, look up the IP
-    addresses in DNS for that hostname, and forget about the hostname
-    if none of the addresses match the client's IP address. You should
-    set this option if you use hostname based instructions. The -p option
-    implies the -h option.
-    * ignored by busyboxed version
--b n
-    backlog. Allow a backlog of approximately n TCP SYNs. On some systems n
-    is silently limited. Default is 20.
--E
-    no special environment. Do not set up TCP-related environment variables.
--v
-    verbose. Print verbose messsages to standard output.
--vv
-    more verbose. Print more verbose messages to standard output.
-    * no difference between -v and -vv in busyboxed version
-*/