another tcp apps IPv6 updates.(should be make world safe)

  ftp, telnet, ftpd, faithd
  also telnet related sync with crypto, secure, kerberosIV

Obtained from: KAME project

1 files changed, 1139 insertions, 0 deletions

diff --git a/usr.sbin/faithd/ftp.c b/usr.sbin/faithd/ftp.c
new file mode 100644
index 0000000..fcb25e3
--- /dev/null
+++ b/usr.sbin/faithd/ftp.c
@@ -0,0 +1,1139 @@
+/*
+ * Copyright (C) 1997 and 1998 WIDE Project.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <errno.h>
+#include <ctype.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include "faithd.h"
+
+static char rbuf[MSS];
+static char sbuf[MSS];
+static int passivemode = 0;
+static int wport4 = -1;			/* listen() to active */
+static int wport6 = -1;			/* listen() to passive */
+static int port4 = -1;			/* active: inbound  passive: outbound */
+static int port6 = -1;			/* active: outbound  passive: inbound */
+static struct sockaddr_storage data4;	/* server data address */
+static struct sockaddr_storage data6;	/* client data address */
+static int epsvall = 0;
+
+#ifdef FAITH4
+enum state { NONE, LPRT, EPRT, PORT, LPSV, EPSV, PASV };
+#else
+enum state { NONE, LPRT, EPRT, LPSV, EPSV };
+#endif
+
+static int ftp_activeconn __P((void));
+static int ftp_passiveconn __P((void));
+static int ftp_copy __P((int, int));
+static int ftp_copyresult __P((int, int, enum state));
+static int ftp_copycommand __P((int, int, enum state *));
+
+void
+ftp_relay(int ctl6, int ctl4)
+{
+	fd_set readfds;
+	int error;
+	enum state state = NONE;
+	struct timeval tv;
+
+	syslog(LOG_INFO, "starting ftp control connection");
+
+	for (;;) {
+		FD_ZERO(&readfds);
+		FD_SET(ctl4, &readfds);
+		FD_SET(ctl6, &readfds);
+		if (0 <= port4)
+			FD_SET(port4, &readfds);
+		if (0 <= port6)
+			FD_SET(port6, &readfds);
+#if 0
+		if (0 <= wport4)
+			FD_SET(wport4, &readfds);
+		if (0 <= wport6)
+			FD_SET(wport6, &readfds);
+#endif
+		tv.tv_sec = FAITH_TIMEOUT;
+		tv.tv_usec = 0;
+
+		error = select(256, &readfds, NULL, NULL, &tv);
+		if (error == -1)
+			exit_failure("select: %s", ERRSTR);
+		else if (error == 0)
+			exit_failure("connection timeout");
+
+		/*
+		 * The order of the following checks does (slightly) matter.
+		 * It is important to visit all checks (do not use "continue"),
+		 * otherwise some of the pipe may become full and we cannot
+		 * relay correctly.
+		 */
+		if (FD_ISSET(ctl6, &readfds)) {
+			/*
+			 * copy control connection from the client.
+			 * command translation is necessary.
+			 */
+			error = ftp_copycommand(ctl6, ctl4, &state);
+
+			switch (error) {
+			case -1:
+				goto bad;
+			case 0:
+				close(ctl4);
+				close(ctl6);
+				exit_success("terminating ftp control connection");
+				/*NOTREACHED*/
+			default:
+				break;
+			}
+		}
+		if (FD_ISSET(ctl4, &readfds)) {
+			/*
+			 * copy control connection from the server
+			 * translation of result code is necessary.
+			 */
+			error = ftp_copyresult(ctl4, ctl6, state);
+
+			switch (error) {
+			case -1:
+				goto bad;
+			case 0:
+				close(ctl4);
+				close(ctl6);
+				exit_success("terminating ftp control connection");
+				/*NOTREACHED*/
+			default:
+				break;
+			}
+		}
+		if (0 <= port4 && 0 <= port6 && FD_ISSET(port4, &readfds)) {
+			/*
+			 * copy data connection.
+			 * no special treatment necessary.
+			 */
+			if (FD_ISSET(port4, &readfds))
+				error = ftp_copy(port4, port6);
+			switch (error) {
+			case -1:
+				goto bad;
+			case 0:
+				close(port4);
+				close(port6);
+				port4 = port6 = -1;
+				syslog(LOG_INFO, "terminating data connection");
+				break;
+			default:
+				break;
+			}
+		}
+		if (0 <= port4 && 0 <= port6 && FD_ISSET(port6, &readfds)) {
+			/*
+			 * copy data connection.
+			 * no special treatment necessary.
+			 */
+			if (FD_ISSET(port6, &readfds))
+				error = ftp_copy(port6, port4);
+			switch (error) {
+			case -1:
+				goto bad;
+			case 0:
+				close(port4);
+				close(port6);
+				port4 = port6 = -1;
+				syslog(LOG_INFO, "terminating data connection");
+				break;
+			default:
+				break;
+			}
+		}
+#if 0
+		if (wport4 && FD_ISSET(wport4, &readfds)) {
+			/*
+			 * establish active data connection from the server.
+			 */
+			ftp_activeconn();
+		}
+		if (wport6 && FD_ISSET(wport6, &readfds)) {
+			/*
+			 * establish passive data connection from the client.
+			 */
+			ftp_passiveconn();
+		}
+#endif
+	}
+
+ bad:
+	exit_failure(ERRSTR);
+}
+
+static int
+ftp_activeconn()
+{
+	int n;
+	int error;
+	fd_set set;
+	struct timeval timeout;
+	struct sockaddr *sa;
+
+	/* get active connection from server */
+	FD_ZERO(&set);
+	FD_SET(wport4, &set);
+	timeout.tv_sec = 120;
+	timeout.tv_usec = -1;
+	n = sizeof(data4);
+	if (select(wport4 + 1, &set, NULL, NULL, &timeout) == 0
+	 || (port4 = accept(wport4, (struct sockaddr *)&data4, &n)) < 0) {
+		close(wport4);
+		wport4 = -1;
+		syslog(LOG_INFO, "active mode data connection failed");
+		return -1;
+	}
+
+	/* ask active connection to client */
+	sa = (struct sockaddr *)&data6;
+	port6 = socket(sa->sa_family, SOCK_STREAM, 0);
+	if (port6 == -1) {
+		close(port4);
+		close(wport4);
+		port4 = wport4 = -1;
+		syslog(LOG_INFO, "active mode data connection failed");
+		return -1;
+	}
+	error = connect(port6, sa, sa->sa_len);
+	if (port6 == -1) {
+		close(port6);
+		close(port4);
+		close(wport4);
+		port6 = port4 = wport4 = -1;
+		syslog(LOG_INFO, "active mode data connection failed");
+		return -1;
+	}
+
+	syslog(LOG_INFO, "active mode data connection established");
+	return 0;
+}
+
+static int
+ftp_passiveconn()
+{
+	int n;
+	int error;
+	fd_set set;
+	struct timeval timeout;
+	struct sockaddr *sa;
+
+	/* get passive connection from client */
+	FD_ZERO(&set);
+	FD_SET(wport6, &set);
+	timeout.tv_sec = 120;
+	timeout.tv_usec = 0;
+	n = sizeof(data6);
+	if (select(wport6 + 1, &set, NULL, NULL, &timeout) == 0
+	 || (port6 = accept(wport6, (struct sockaddr *)&data6, &n)) < 0) {
+		close(wport6);
+		wport6 = -1;
+		syslog(LOG_INFO, "passive mode data connection failed");
+		return -1;
+	}
+
+	/* ask passive connection to server */
+	sa = (struct sockaddr *)&data4;
+	port4 = socket(sa->sa_family, SOCK_STREAM, 0);
+	if (port4 == -1) {
+		close(wport6);
+		close(port6);
+		wport6 = port6 = -1;
+		syslog(LOG_INFO, "passive mode data connection failed");
+		return -1;
+	}
+	error = connect(port4, sa, sa->sa_len);
+	if (port4 == -1) {
+		close(wport6);
+		close(port4);
+		close(port6);
+		wport6 = port4 = port6 = -1;
+		syslog(LOG_INFO, "passive mode data connection failed");
+		return -1;
+	}
+
+	syslog(LOG_INFO, "passive mode data connection established");
+	return 0;
+}
+
+static int
+ftp_copy(int src, int dst)
+{
+	int error, atmark;
+	int n;
+
+	/* OOB data handling */
+	error = ioctl(src, SIOCATMARK, &atmark);
+	if (error != -1 && atmark == 1) {
+		n = read(src, rbuf, 1);
+		if (n == -1)
+			goto bad;
+		send(dst, rbuf, n, MSG_OOB);
+#if 0
+		n = read(src, rbuf, sizeof(rbuf));
+		if (n == -1)
+			goto bad;
+		write(dst, rbuf, n);
+		return n;
+#endif
+	}
+
+	n = read(src, rbuf, sizeof(rbuf));
+	switch (n) {
+	case -1:
+	case 0:
+		return n;
+	default:
+		write(dst, rbuf, n);
+		return n;
+	}
+
+ bad:
+	exit_failure(ERRSTR);
+	/*NOTREACHED*/
+	return 0;	/* to make gcc happy */
+}
+
+static int
+ftp_copyresult(int src, int dst, enum state state)
+{
+	int error, atmark;
+	int n;
+	char *param;
+	int code;
+
+	/* OOB data handling */
+	error = ioctl(src, SIOCATMARK, &atmark);
+	if (error != -1 && atmark == 1) {
+		n = read(src, rbuf, 1);
+		if (n == -1)
+			goto bad;
+		send(dst, rbuf, n, MSG_OOB);
+#if 0
+		n = read(src, rbuf, sizeof(rbuf));
+		if (n == -1)
+			goto bad;
+		write(dst, rbuf, n);
+		return n;
+#endif
+	}
+
+	n = read(src, rbuf, sizeof(rbuf));
+	if (n <= 0)
+		return n;
+	rbuf[n] = '\0';
+
+	/*
+	 * parse argument
+	 */
+    {
+	char *p;
+	int i;
+
+	p = rbuf;
+	for (i = 0; i < 3; i++) {
+		if (!isdigit(*p)) {
+			/* invalid reply */
+			write(dst, rbuf, n);
+			return n;
+		}
+		p++;
+	}
+	if (!isspace(*p)) {
+		/* invalid reply */
+		write(dst, rbuf, n);
+		return n;
+	}
+	code = atoi(rbuf);
+	param = p;
+	/* param points to first non-command token, if any */
+	while (*param && isspace(*param))
+		param++;
+	if (!*param)
+		param = NULL;
+    }
+
+	switch (state) {
+	case NONE:
+		if (!passivemode && rbuf[0] == '1') {
+			if (ftp_activeconn() < 0) {
+				n = snprintf(rbuf, sizeof(rbuf),
+					"425 Cannot open data connetion\r\n");
+			}
+		}
+		write(dst, rbuf, n);
+		return n;
+	case LPRT:
+	case EPRT:
+		/* expecting "200 PORT command successful." */
+		if (code == 200) {
+			char *p;
+
+			p = strstr(rbuf, "PORT");
+			if (p) {
+				p[0] = (state == LPRT) ? 'L' : 'E';
+				p[1] = 'P';
+			}
+		} else {
+			close(wport4);
+			wport4 = -1;
+		}
+		write(dst, rbuf, n);
+		return n;
+#ifdef FAITH4
+	case PORT:
+		/* expecting "200 EPRT command successful." */
+		if (code == 200) {
+			char *p;
+
+			p = strstr(rbuf, "EPRT");
+			if (p) {
+				p[0] = 'P';
+				p[1] = 'O';
+			}
+		} else {
+			close(wport4);
+			wport4 = -1;
+		}
+		write(dst, rbuf, n);
+		return n;
+#endif
+	case LPSV:
+	case EPSV:
+		/* expecting "227 Entering Passive Mode (x,x,x,x,x,x,x)" */
+		if (code != 227) {
+passivefail0:
+			close(wport6);
+			wport6 = -1;
+			write(dst, rbuf, n);
+			return n;
+		}
+
+	    {
+		unsigned int ho[4], po[2];
+		struct sockaddr_in *sin;
+		struct sockaddr_in6 *sin6;
+		u_short port;
+		char *p;
+
+		/*
+		 * PASV result -> LPSV/EPSV result
+		 */
+		p = param;
+		while (*p && *p != '(')
+			p++;
+		if (!*p)
+			goto passivefail0;	/*XXX*/
+		p++;
+		n = sscanf(p, "%u,%u,%u,%u,%u,%u",
+			&ho[0], &ho[1], &ho[2], &ho[3], &po[0], &po[1]);
+		if (n != 6)
+			goto passivefail0;	/*XXX*/
+
+		/* keep PORT parameter */
+		memset(&data4, 0, sizeof(data4));
+		sin = (struct sockaddr_in *)&data4;
+		sin->sin_len = sizeof(*sin);
+		sin->sin_family = AF_INET;
+		sin->sin_addr.s_addr = 0;
+		for (n = 0; n < 4; n++) {
+			sin->sin_addr.s_addr |=
+				htonl((ho[n] & 0xff) << ((3 - n) * 8));
+		}
+		sin->sin_port = htons(((po[0] & 0xff) << 8) | (po[1] & 0xff));
+
+		/* get ready for passive data connection */
+		memset(&data6, 0, sizeof(data6));
+		sin6 = (struct sockaddr_in6 *)&data6;
+		sin6->sin6_len = sizeof(*sin6);
+		sin6->sin6_family = AF_INET6;
+		wport6 = socket(sin6->sin6_family, SOCK_STREAM, 0);
+		if (wport6 == -1) {
+passivefail:
+			n = snprintf(sbuf, sizeof(sbuf),
+				"500 could not translate from PASV\r\n");
+			write(src, sbuf, n);
+			return n;
+		}
+#ifdef IPV6_FAITH
+	    {
+		int on = 1;
+		error = setsockopt(wport6, IPPROTO_IPV6, IPV6_FAITH,
+			&on, sizeof(on));
+		if (error == -1)
+			exit_error("setsockopt(IPV6_FAITH): %s", ERRSTR);
+	    }
+#endif
+		error = bind(wport6, (struct sockaddr *)sin6, sin6->sin6_len);
+		if (error == -1) {
+			close(wport6);
+			wport6 = -1;
+			goto passivefail;
+		}
+		error = listen(wport6, 1);
+		if (error == -1) {
+			close(wport6);
+			wport6 = -1;
+			goto passivefail;
+		}
+
+		/* transmit LPSV or EPSV */
+		/*
+		 * addr from dst, port from wport6
+		 */
+		n = sizeof(data6);
+		error = getsockname(wport6, (struct sockaddr *)&data6, &n);
+		if (error == -1) {
+			close(wport6);
+			wport6 = -1;
+			goto passivefail;
+		}
+		sin6 = (struct sockaddr_in6 *)&data6;
+		port = sin6->sin6_port;
+
+		n = sizeof(data6);
+		error = getsockname(dst, (struct sockaddr *)&data6, &n);
+		if (error == -1) {
+			close(wport6);
+			wport6 = -1;
+			goto passivefail;
+		}
+		sin6 = (struct sockaddr_in6 *)&data6;
+		sin6->sin6_port = port;
+
+		if (state == LPSV) {
+			char *a, *p;
+
+			a = (char *)&sin6->sin6_addr;
+			p = (char *)&sin6->sin6_port;
+			n = snprintf(sbuf, sizeof(sbuf),
+"228 Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)\r\n",
+				6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]), 
+				UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]), 
+				UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]), 
+				UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]), 
+				2, UC(p[0]), UC(p[1]));
+			write(dst, sbuf, n);
+			passivemode = 1;
+			return n;
+		} else {
+			n = snprintf(sbuf, sizeof(sbuf),
+"229 Entering Extended Passive Mode (|||%d|)\r\n",
+				ntohs(sin6->sin6_port));
+			write(dst, sbuf, n);
+			passivemode = 1;
+			return n;
+		}
+	    }
+#ifdef FAITH4
+	case PASV:
+		/* expecting "229 Entering Extended Passive Mode (|||x|)" */
+		if (code != 229) {
+passivefail1:
+			close(wport6);
+			wport6 = -1;
+			write(dst, rbuf, n);
+			return n;
+		}
+
+	    {
+		u_short port;
+		char *p;
+		struct sockaddr_in *sin;
+		struct sockaddr_in6 *sin6;
+
+		/*
+		 * EPSV result -> PORT result
+		 */
+		p = param;
+		while (*p && *p != '(')
+			p++;
+		if (!*p)
+			goto passivefail1;	/*XXX*/
+		p++;
+		n = sscanf(p, "|||%hu|", &port);
+		if (n != 1)
+			goto passivefail1;	/*XXX*/
+
+		/* keep EPRT parameter */
+		n = sizeof(data4);
+		error = getpeername(src, (struct sockaddr *)&data4, &n);
+		if (error == -1)
+			goto passivefail1;	/*XXX*/
+		sin6 = (struct sockaddr_in6 *)&data4;
+		sin6->sin6_port = htons(port);
+
+		/* get ready for passive data connection */
+		memset(&data6, 0, sizeof(data6));
+		sin = (struct sockaddr_in *)&data6;
+		sin->sin_len = sizeof(*sin);
+		sin->sin_family = AF_INET;
+		wport6 = socket(sin->sin_family, SOCK_STREAM, 0);
+		if (wport6 == -1) {
+passivefail2:
+			n = snprintf(sbuf, sizeof(sbuf),
+				"500 could not translate from EPSV\r\n");
+			write(src, sbuf, n);
+			return n;
+		}
+#ifdef IP_FAITH
+	    {
+		int on = 1;
+		error = setsockopt(wport6, IPPROTO_IP, IP_FAITH,
+			&on, sizeof(on));
+		if (error == -1)
+			exit_error("setsockopt(IP_FAITH): %s", ERRSTR);
+	    }
+#endif
+		error = bind(wport6, (struct sockaddr *)sin, sin->sin_len);
+		if (error == -1) {
+			close(wport6);
+			wport6 = -1;
+			goto passivefail2;
+		}
+		error = listen(wport6, 1);
+		if (error == -1) {
+			close(wport6);
+			wport6 = -1;
+			goto passivefail2;
+		}
+
+		/* transmit PORT */
+		/*
+		 * addr from dst, port from wport6
+		 */
+		n = sizeof(data6);
+		error = getsockname(wport6, (struct sockaddr *)&data6, &n);
+		if (error == -1) {
+			close(wport6);
+			wport6 = -1;
+			goto passivefail2;
+		}
+		sin = (struct sockaddr_in *)&data6;
+		port = sin->sin_port;
+
+		n = sizeof(data6);
+		error = getsockname(dst, (struct sockaddr *)&data6, &n);
+		if (error == -1) {
+			close(wport6);
+			wport6 = -1;
+			goto passivefail2;
+		}
+		sin = (struct sockaddr_in *)&data6;
+		sin->sin_port = port;
+
+		{
+			char *a, *p;
+
+			a = (char *)&sin->sin_addr;
+			p = (char *)&sin->sin_port;
+			n = snprintf(sbuf, sizeof(sbuf),
+"227 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n",
+				UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]), 
+				UC(p[0]), UC(p[1]));
+			write(dst, sbuf, n);
+			passivemode = 1;
+			return n;
+		}
+	    }
+#endif /* FAITH4 */
+	}
+
+ bad:
+	exit_failure(ERRSTR);
+	/*NOTREACHED*/
+	return 0;	/* to make gcc happy */
+}
+
+static int
+ftp_copycommand(int src, int dst, enum state *state)
+{
+	int error, atmark;
+	int n;
+	unsigned int af, hal, ho[16], pal, po[2];
+	char *a, *p;
+	char cmd[5], *param;
+	struct sockaddr_in *sin;
+	struct sockaddr_in6 *sin6;
+	enum state nstate;
+	char ch;
+
+	/* OOB data handling */
+	error = ioctl(src, SIOCATMARK, &atmark);
+	if (error != -1 && atmark == 1) {
+		n = read(src, rbuf, 1);
+		if (n == -1)
+			goto bad;
+		send(dst, rbuf, n, MSG_OOB);
+#if 0
+		n = read(src, rbuf, sizeof(rbuf));
+		if (n == -1)
+			goto bad;
+		write(dst, rbuf, n);
+		return n;
+#endif
+	}
+
+	n = read(src, rbuf, sizeof(rbuf));
+	if (n <= 0)
+		return n;
+	rbuf[n] = '\0';
+
+	if (n < 4) {
+		write(dst, rbuf, n);
+		return n;
+	}
+
+	/*
+	 * parse argument
+	 */
+    {
+	char *p, *q;
+	int i;
+
+	p = rbuf;
+	q = cmd;
+	for (i = 0; i < 4; i++) {
+		if (!isalpha(*p)) {
+			/* invalid command */
+			write(dst, rbuf, n);
+			return n;
+		}
+		*q++ = islower(*p) ? toupper(*p) : *p;
+		p++;
+	}
+	if (!isspace(*p)) {
+		/* invalid command */
+		write(dst, rbuf, n);
+		return n;
+	}
+	*q = '\0';
+	param = p;
+	/* param points to first non-command token, if any */
+	while (*param && isspace(*param))
+		param++;
+	if (!*param)
+		param = NULL;
+    }
+
+	*state = NONE;
+
+	if (strcmp(cmd, "LPRT") == 0 && param) {
+		/*
+		 * LPRT -> PORT
+		 */
+		nstate = LPRT;
+
+		close(wport4);
+		close(wport6);
+		close(port4);
+		close(port6);
+		wport4 = wport6 = port4 = port6 = -1;
+
+		if (epsvall) {
+			n = snprintf(sbuf, sizeof(sbuf), "501 %s disallowed in EPSV ALL\r\n",
+				cmd);
+			write(src, sbuf, n);
+			return n;
+		}
+
+		n = sscanf(param,
+"%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u",
+			      &af, &hal, &ho[0], &ho[1], &ho[2], &ho[3],
+			      &ho[4], &ho[5], &ho[6], &ho[7],
+			      &ho[8], &ho[9], &ho[10], &ho[11],
+			      &ho[12], &ho[13], &ho[14], &ho[15],
+			      &pal, &po[0], &po[1]);
+		if (n != 21 || af != 6 || hal != 16|| pal != 2) {
+			n = snprintf(sbuf, sizeof(sbuf),
+				"501 illegal parameter to LPRT\r\n");
+			write(src, sbuf, n);
+			return n;
+		}
+
+		/* keep LPRT parameter */
+		memset(&data6, 0, sizeof(data6));
+		sin6 = (struct sockaddr_in6 *)&data6;
+		sin6->sin6_len = sizeof(*sin6);
+		sin6->sin6_family = AF_INET6;
+		for (n = 0; n < 16; n++)
+			sin6->sin6_addr.s6_addr[n] = ho[n];
+		sin6->sin6_port = htons(((po[0] & 0xff) << 8) | (po[1] & 0xff));
+
+sendport:
+		/* get ready for active data connection */
+		n = sizeof(data4);
+		error = getsockname(dst, (struct sockaddr *)&data4, &n);
+		if (error == -1) {
+lprtfail:
+			n = snprintf(sbuf, sizeof(sbuf),
+				"500 could not translate to PORT\r\n");
+			write(src, sbuf, n);
+			return n;
+		}
+		if (((struct sockaddr *)&data4)->sa_family != AF_INET)
+			goto lprtfail;
+		sin = (struct sockaddr_in *)&data4;
+		sin->sin_port = 0;
+		wport4 = socket(sin->sin_family, SOCK_STREAM, 0);
+		if (wport4 == -1)
+			goto lprtfail;
+		error = bind(wport4, (struct sockaddr *)sin, sin->sin_len);
+		if (error == -1) {
+			close(wport4);
+			wport4 = -1;
+			goto lprtfail;
+		}
+		error = listen(wport4, 1);
+		if (error == -1) {
+			close(wport4);
+			wport4 = -1;
+			goto lprtfail;
+		}
+
+		/* transmit PORT */
+		n = sizeof(data4);
+		error = getsockname(wport4, (struct sockaddr *)&data4, &n);
+		if (error == -1) {
+			close(wport4);
+			wport4 = -1;
+			goto lprtfail;
+		}
+		if (((struct sockaddr *)&data4)->sa_family != AF_INET) {
+			close(wport4);
+			wport4 = -1;
+			goto lprtfail;
+		}
+		sin = (struct sockaddr_in *)&data4;
+		a = (char *)&sin->sin_addr;
+		p = (char *)&sin->sin_port;
+		n = snprintf(sbuf, sizeof(sbuf), "PORT %d,%d,%d,%d,%d,%d\r\n",
+				  UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
+				  UC(p[0]), UC(p[1]));
+		write(dst, sbuf, n);
+		*state = nstate;
+		passivemode = 0;
+		return n;
+	} else if (strcmp(cmd, "EPRT") == 0 && param) {
+		/*
+		 * EPRT -> PORT
+		 */
+		char *afp, *hostp, *portp;
+		struct addrinfo hints, *res;
+
+		nstate = EPRT;
+
+		close(wport4);
+		close(wport6);
+		close(port4);
+		close(port6);
+		wport4 = wport6 = port4 = port6 = -1;
+
+		if (epsvall) {
+			n = snprintf(sbuf, sizeof(sbuf), "501 %s disallowed in EPSV ALL\r\n",
+				cmd);
+			write(src, sbuf, n);
+			return n;
+		}
+
+		p = param;
+		ch = *p++;	/* boundary character */
+		afp = p;
+		while (*p && *p != ch)
+			p++;
+		if (!*p) {
+eprtparamfail:
+			n = snprintf(sbuf, sizeof(sbuf),
+				"501 illegal parameter to EPRT\r\n");
+			write(src, sbuf, n);
+			return n;
+		}
+		*p++ = '\0';
+		hostp = p;
+		while (*p && *p != ch)
+			p++;
+		if (!*p)
+			goto eprtparamfail;
+		*p++ = '\0';
+		portp = p;
+		while (*p && *p != ch)
+			p++;
+		if (!*p)
+			goto eprtparamfail;
+		*p++ = '\0';
+
+		n = sscanf(afp, "%d", &af);
+		if (n != 1 || af != 2) {
+			n = snprintf(sbuf, sizeof(sbuf),
+				"501 unsupported address family to EPRT\r\n");
+			write(src, sbuf, n);
+			return n;
+		}
+		memset(&hints, 0, sizeof(hints));
+		hints.ai_family = AF_UNSPEC;
+		error = getaddrinfo(hostp, portp, &hints, &res);
+		if (error) {
+			n = snprintf(sbuf, sizeof(sbuf),
+				"501 EPRT: %s", gai_strerror(error));
+			if (error == EAI_SYSTEM)
+				n += snprintf(sbuf, sizeof(sbuf),
+					      ": %s", strerror(errno));
+			n +=  snprintf(sbuf, sizeof(sbuf), "\r\n");
+
+			write(src, sbuf, n);
+			return n;
+		}
+		if (res->ai_next) {
+			n = snprintf(sbuf, sizeof(sbuf),
+				"501 EPRT: %s resolved to multiple addresses\r\n", hostp);
+			write(src, sbuf, n);
+			return n;
+		}
+
+		memcpy(&data6, res->ai_addr, res->ai_addrlen);
+
+		goto sendport;
+	} else if (strcmp(cmd, "LPSV") == 0 && !param) {
+		/*
+		 * LPSV -> PASV
+		 */
+		nstate = LPSV;
+
+		close(wport4);
+		close(wport6);
+		close(port4);
+		close(port6);
+		wport4 = wport6 = port4 = port6 = -1;
+
+		if (epsvall) {
+			n = snprintf(sbuf, sizeof(sbuf), "501 %s disallowed in EPSV ALL\r\n",
+				cmd);
+			write(src, sbuf, n);
+			return n;
+		}
+
+		/* transmit PASV */
+		n = snprintf(sbuf, sizeof(sbuf), "PASV\r\n");
+		write(dst, sbuf, n);
+		*state = LPSV;
+		passivemode = 0;	/* to be set to 1 later */
+		return n;
+	} else if (strcmp(cmd, "EPSV") == 0 && !param) {
+		/*
+		 * EPSV -> PASV
+		 */
+		close(wport4);
+		close(wport6);
+		close(port4);
+		close(port6);
+		wport4 = wport6 = port4 = port6 = -1;
+
+		n = snprintf(sbuf, sizeof(sbuf), "PASV\r\n");
+		write(dst, sbuf, n);
+		*state = EPSV;
+		passivemode = 0;	/* to be set to 1 later */
+		return n;
+	} else if (strcmp(cmd, "EPSV") == 0 && param
+	 && strncasecmp(param, "ALL", 3) == 0 && isspace(param[3])) {
+		/*
+		 * EPSV ALL
+		 */
+		epsvall = 1;
+		n = snprintf(sbuf, sizeof(sbuf), "200 EPSV ALL command successful.\r\n");
+		write(src, sbuf, n);
+		return n;
+#ifdef FAITH4
+	} else if (strcmp(cmd, "PORT") == 0 && param) {
+		/*
+		 * PORT -> EPRT
+		 */
+		char host[NI_MAXHOST], serv[NI_MAXSERV];
+
+		nstate = PORT;
+
+		close(wport4);
+		close(wport6);
+		close(port4);
+		close(port6);
+		wport4 = wport6 = port4 = port6 = -1;
+
+		p = param;
+		n = sscanf(p, "%u,%u,%u,%u,%u,%u",
+			&ho[0], &ho[1], &ho[2], &ho[3], &po[0], &po[1]);
+		if (n != 6) {
+			n = snprintf(sbuf, sizeof(sbuf),
+				"501 illegal parameter to PORT\r\n");
+			write(src, sbuf, n);
+			return n;
+		}
+
+		memset(&data6, 0, sizeof(data6));
+		sin = (struct sockaddr_in *)&data6;
+		sin->sin_len = sizeof(*sin);
+		sin->sin_family = AF_INET;
+		sin->sin_addr.s_addr = htonl(
+			((ho[0] & 0xff) << 24) | ((ho[1] & 0xff) << 16) |
+			((ho[2] & 0xff) << 8) | (ho[3] & 0xff));
+		sin->sin_port = htons(((po[0] & 0xff) << 8) | (po[1] & 0xff));
+
+		/* get ready for active data connection */
+		n = sizeof(data4);
+		error = getsockname(dst, (struct sockaddr *)&data4, &n);
+		if (error == -1) {
+portfail:
+			n = snprintf(sbuf, sizeof(sbuf),
+				"500 could not translate to EPRT\r\n");
+			write(src, sbuf, n);
+			return n;
+		}
+		if (((struct sockaddr *)&data4)->sa_family != AF_INET6)
+			goto portfail;
+
+		((struct sockaddr_in6 *)&data4)->sin6_port = 0;
+		sa = (struct sockaddr *)&data4;
+		wport4 = socket(sa->sa_family, SOCK_STREAM, 0);
+		if (wport4 == -1)
+			goto portfail;
+		error = bind(wport4, sa, sa->sa_len);
+		if (error == -1) {
+			close(wport4);
+			wport4 = -1;
+			goto portfail;
+		}
+		error = listen(wport4, 1);
+		if (error == -1) {
+			close(wport4);
+			wport4 = -1;
+			goto portfail;
+		}
+
+		/* transmit EPRT */
+		n = sizeof(data4);
+		error = getsockname(wport4, (struct sockaddr *)&data4, &n);
+		if (error == -1) {
+			close(wport4);
+			wport4 = -1;
+			goto portfail;
+		}
+		af = 2;
+		sa = (struct sockaddr *)&data4;
+		if (getnameinfo(sa, sa->sa_len, host, sizeof(host),
+			serv, sizeof(serv), NI_NUMERICHOST | NI_NUMERICSERV)) {
+			close(wport4);
+			wport4 = -1;
+			goto portfail;
+		}
+		n = snprintf(sbuf, sizeof(sbuf), "EPRT |%d|%s|%s|\r\n", af, host, serv);
+		write(dst, sbuf, n);
+		*state = nstate;
+		passivemode = 0;
+		return n;
+	} else if (strcmp(cmd, "PASV") == 0 && !param) {
+		/*
+		 * PASV -> EPSV
+		 */
+
+		nstate = PASV;
+
+		close(wport4);
+		close(wport6);
+		close(port4);
+		close(port6);
+		wport4 = wport6 = port4 = port6 = -1;
+
+		/* transmit EPSV */
+		n = snprintf(sbuf, sizeof(sbuf), "EPSV\r\n");
+		write(dst, sbuf, n);
+		*state = PASV;
+		passivemode = 0;	/* to be set to 1 later */
+		return n;
+#else /* FAITH4 */
+	} else if (strcmp(cmd, "PORT") == 0 || strcmp(cmd, "PASV") == 0) {
+		/*
+		 * reject PORT/PASV
+		 */
+		n = snprintf(sbuf, sizeof(sbuf), "502 %s not implemented.\r\n", cmd);
+		write(src, sbuf, n);
+		return n;
+#endif /* FAITH4 */
+	} else if (passivemode
+		&& (strcmp(cmd, "STOR") == 0
+		 || strcmp(cmd, "STOU") == 0
+		 || strcmp(cmd, "RETR") == 0
+		 || strcmp(cmd, "LIST") == 0
+		 || strcmp(cmd, "NLST") == 0
+		 || strcmp(cmd, "APPE") == 0)) {
+		/*
+		 * commands with data transfer.  need to care about passive
+		 * mode data connection.
+		 */
+
+		if (ftp_passiveconn() < 0) {
+			n = snprintf(sbuf, sizeof(sbuf), "425 Cannot open data connetion\r\n");
+			write(src, sbuf, n);
+		} else {
+			/* simply relay the command */
+			write(dst, rbuf, n);
+		}
+
+		*state = NONE;
+		return n;
+	} else {
+		/* simply relay it */
+		*state = NONE;
+		write(dst, rbuf, n);
+		return n;
+	}
+
+ bad:
+	exit_failure(ERRSTR);
+	/*NOTREACHED*/
+	return 0;	/* to make gcc happy */
+}