root/usr.bin/ftp/ftp.c
/*      $NetBSD: ftp.c,v 1.181 2026/02/07 03:11:20 lukem Exp $  */

/*-
 * Copyright (c) 1996-2026 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Luke Mewburn.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Copyright (c) 1985, 1989, 1993, 1994
 *      The Regents of the University of California.  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 University 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 REGENTS 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 REGENTS 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.
 */

/*
 * 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.
 */

#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)ftp.c       8.6 (Berkeley) 10/27/94";
#else
__RCSID("$NetBSD: ftp.c,v 1.181 2026/02/07 03:11:20 lukem Exp $");
#endif
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <arpa/ftp.h>
#include <arpa/telnet.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <stdarg.h>

#include "ftp_var.h"

static volatile sig_atomic_t    abrtflag;
static volatile sig_atomic_t    timeoutflag;

static sigjmp_buf       ptabort;
static int      ptabflg;
static int      ptflag = 0;
static char     pasv[BUFSIZ];   /* passive port for proxy data connection */
size_t  ftp_buflen = FTPBUFLEN;

static int empty(FILE *, FILE *, int);
__dead static void abort_squared(int);

struct sockinet {
        union sockunion {
                struct sockaddr_in  su_sin;
#ifdef INET6
                struct sockaddr_in6 su_sin6;
#endif
        } si_su;
#if !defined(HAVE_STRUCT_SOCKADDR_IN_SIN_LEN)
        int     si_len;
#endif
};

#if !defined(HAVE_STRUCT_SOCKADDR_IN_SIN_LEN)
# define su_len         si_len
#else
# define su_len         si_su.su_sin.sin_len
#endif
#define su_family       si_su.su_sin.sin_family
#define su_port         si_su.su_sin.sin_port

static struct sockinet myctladdr, hisctladdr, data_addr;

char *
hookup(const char *host, const char *port)
{
        int s = -1, error;
        struct addrinfo hints, *res, *res0;
        static char hostnamebuf[MAXHOSTNAMELEN];
        socklen_t len;
        int on = 1;

        memset((char *)&hisctladdr, 0, sizeof (hisctladdr));
        memset((char *)&myctladdr, 0, sizeof (myctladdr));
        memset(&hints, 0, sizeof(hints));
        hints.ai_flags = AI_CANONNAME;
        hints.ai_family = family;
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_protocol = 0;
        error = getaddrinfo(host, port, &hints, &res0);
        if (error) {
                warnx("Can't lookup `%s:%s': %s", host, port,
                    (error == EAI_SYSTEM) ? strerror(errno)
                                          : gai_strerror(error));
                code = -1;
                return (0);
        }

        if (res0->ai_canonname)
                (void)strlcpy(hostnamebuf, res0->ai_canonname,
                    sizeof(hostnamebuf));
        else
                (void)strlcpy(hostnamebuf, host, sizeof(hostnamebuf));
        hostname = hostnamebuf;

        for (res = res0; res; res = res->ai_next) {
                char hname[NI_MAXHOST], sname[NI_MAXSERV];

                ai_unmapped(res);
                if (getnameinfo(res->ai_addr, res->ai_addrlen,
                    hname, sizeof(hname), sname, sizeof(sname),
                    NI_NUMERICHOST | NI_NUMERICSERV) != 0) {
                        strlcpy(hname, "?", sizeof(hname));
                        strlcpy(sname, "?", sizeof(sname));
                }
                if (verbose && res0->ai_next) {
                                /* if we have multiple possibilities */
#ifdef INET6
                        if(res->ai_family == AF_INET6) {
                                fprintf(ttyout, "Trying [%s]:%s ...\n", hname,
                                    sname);
                        } else {
#endif
                                fprintf(ttyout, "Trying %s:%s ...\n", hname,
                                    sname);
#ifdef INET6
                        }
#endif
                }
                s = socket(res->ai_family, SOCK_STREAM, res->ai_protocol);
                if (s < 0) {
                        warn("Can't create socket for connection to `%s:%s'",
                            hname, sname);
                        continue;
                }
                if (ftp_connect(s, res->ai_addr, res->ai_addrlen,
                    verbose || !res->ai_next) < 0) {
                        close(s);
                        s = -1;
                        continue;
                }

                /* finally we got one */
                break;
        }
        if (s < 0) {
                warnx("Can't connect to `%s:%s'", host, port);
                code = -1;
                freeaddrinfo(res0);
                return 0;
        }
        memcpy(&hisctladdr.si_su, res->ai_addr, res->ai_addrlen);
        hisctladdr.su_len = res->ai_addrlen;
        freeaddrinfo(res0);
        res0 = res = NULL;

        len = hisctladdr.su_len;
        if (getsockname(s, (struct sockaddr *)(void *)&myctladdr.si_su, &len) == -1) {
                warn("Can't determine my address of connection to `%s:%s'",
                    host, port);
                code = -1;
                goto bad;
        }
        myctladdr.su_len = len;

#ifdef IPTOS_LOWDELAY
        if (hisctladdr.su_family == AF_INET) {
                int tos = IPTOS_LOWDELAY;
                if (setsockopt(s, IPPROTO_IP, IP_TOS,
                                (void *)&tos, sizeof(tos)) == -1) {
                                DWARN("setsockopt %s (ignored)",
                                    "IPTOS_LOWDELAY");
                }
        }
#endif
        cin = fdopen(s, "r");
        cout = fdopen(s, "w");
        if (cin == NULL || cout == NULL) {
                warnx("Can't fdopen socket");
                if (cin)
                        (void)fclose(cin);
                if (cout)
                        (void)fclose(cout);
                code = -1;
                goto bad;
        }
        if (verbose)
                fprintf(ttyout, "Connected to %s.\n", hostname);
        if (getreply(0) > 2) {  /* read startup message from server */
                if (cin)
                        (void)fclose(cin);
                if (cout)
                        (void)fclose(cout);
                code = -1;
                goto bad;
        }

        if (setsockopt(s, SOL_SOCKET, SO_KEEPALIVE,
                        (void *)&on, sizeof(on)) == -1) {
                DWARN("setsockopt %s (ignored)", "SO_KEEPALIVE");
        }

        if (setsockopt(s, SOL_SOCKET, SO_OOBINLINE,
                        (void *)&on, sizeof(on)) == -1) {
                DWARN("setsockopt %s (ignored)", "SO_OOBINLINE");
        }

        return (hostname);
 bad:
        (void)close(s);
        return (NULL);
}

void
cmdabort(int notused __unused)
{
        int oerrno = errno;

        sigint_raised = 1;
        alarmtimer(0);
        if (fromatty)
                write(fileno(ttyout), "\n", 1);
        abrtflag++;
        if (ptflag)
                siglongjmp(ptabort, 1);
        errno = oerrno;
}

void
cmdtimeout(int notused __unused)
{
        int oerrno = errno;

        alarmtimer(0);
        if (fromatty)
                write(fileno(ttyout), "\n", 1);
        timeoutflag++;
        if (ptflag)
                siglongjmp(ptabort, 1);
        errno = oerrno;
}

static int
issighandler(sigfunc func)
{
        return (func != SIG_IGN &&
                func != SIG_DFL &&
#ifdef SIG_HOLD
                func != SIG_HOLD &&
#endif
                func != SIG_ERR);
}

/*VARARGS*/
int
command(const char *fmt, ...)
{
        va_list ap;
        int r;
        sigfunc oldsigint;

#ifndef NO_DEBUG
        if (ftp_debug) {
                fputs("---> ", ttyout);
                va_start(ap, fmt);
                if (strncmp("PASS ", fmt, 5) == 0)
                        fputs("PASS XXXX", ttyout);
                else if (strncmp("ACCT ", fmt, 5) == 0)
                        fputs("ACCT XXXX", ttyout);
                else
                        vfprintf(ttyout, fmt, ap);
                va_end(ap);
                putc('\n', ttyout);
        }
#endif
        if (cout == NULL) {
                warnx("No control connection for command");
                code = -1;
                return (0);
        }

        abrtflag = 0;

        oldsigint = xsignal(SIGINT, cmdabort);

        va_start(ap, fmt);
        vfprintf(cout, fmt, ap);        /* TODO: handle EINTR? */
        va_end(ap);
        fputs("\r\n", cout);            /* TODO: handle EINTR? */
        (void)fflush(cout);
        cpend = 1;
        r = getreply(!strcmp(fmt, "QUIT"));
        if (abrtflag && issighandler(oldsigint)) {
                (*oldsigint)(SIGINT);
        }
        (void)xsignal(SIGINT, oldsigint);
        return (r);
}

static const char *m421[] = {
        "remote server timed out. Connection closed",
        "user interrupt. Connection closed",
        "remote server has closed connection",
};

int
getreply(int expecteof)
{
        char current_line[BUFSIZ];      /* last line of previous reply */
        int c, n, lineno;
        int dig;
        int originalcode = 0, continuation = 0;
        sigfunc oldsigint, oldsigalrm;
        int pflag = 0;
        char *cp, *pt = pasv;
        int cin_errno = 0;

        abrtflag = 0;
        timeoutflag = 0;

        oldsigint = xsignal(SIGINT, cmdabort);
        oldsigalrm = xsignal(SIGALRM, cmdtimeout);

        for (lineno = 0 ;; lineno++) {
                dig = n = code = 0;
                cp = current_line;
                while (alarmtimer(quit_time ? quit_time : 60),
                       ((c = ftp_getc(cin, &cin_errno)) != '\n')) {
                        if (c == IAC) {     /* handle telnet commands */
                                switch (c = ftp_getc(cin, &cin_errno)) {
                                case WILL:
                                case WONT:
                                        c = ftp_getc(cin, &cin_errno);
                                        if (c != EOF) {
                                                fprintf(cout, "%c%c%c",
                                                    IAC, DONT, c);
                                                /* TODO: handle EINTR? */
                                                (void)fflush(cout);
                                        }
                                        break;
                                case DO:
                                case DONT:
                                        c = ftp_getc(cin, &cin_errno);
                                        if (c != EOF) {
                                                fprintf(cout, "%c%c%c",
                                                    IAC, WONT, c);
                                                /* TODO: handle EINTR? */
                                                (void)fflush(cout);
                                        }
                                        break;
                                default:
                                        break;
                                }
                                continue;
                        }
                        dig++;
                        if (c == EOF) {
                                /*
                                 * these will get trashed by pswitch()
                                 * in lostpeer()
                                 */
                                int reply_timeoutflag = timeoutflag;
                                int reply_abrtflag = abrtflag;

                                alarmtimer(0);
                                if (expecteof && feof(cin)) {
                                        (void)xsignal(SIGINT, oldsigint);
                                        (void)xsignal(SIGALRM, oldsigalrm);
                                        code = 221;
                                        return (0);
                                }
                                cpend = 0;
                                lostpeer(0);
                                if (verbose) {
                                        size_t midx;
                                        if (reply_timeoutflag)
                                                midx = 0;
                                        else if (reply_abrtflag)
                                                midx = 1;
                                        else
                                                midx = 2;
                                        (void)fprintf(ttyout,
                            "421 Service not available, %s.\n", m421[midx]);
                                        (void)fflush(ttyout);
                                }
                                code = 421;
                                (void)xsignal(SIGINT, oldsigint);
                                (void)xsignal(SIGALRM, oldsigalrm);
                                return (4);
                        }
                        if (c != '\r' && (verbose > 0 ||
                            ((verbose > -1 && n == '5' && dig > 4) &&
                            (((!n && c < '5') || (n && n < '5'))
                             || !retry_connect)))) {
                                if (proxflag &&
                                   (dig == 1 || (dig == 5 && verbose == 0)))
                                        fprintf(ttyout, "%s:", hostname);
                                (void)putc(c, ttyout);
                        }
                        if (dig < 4 && isdigit(c))
                                code = code * 10 + (c - '0');
                        if (!pflag && (code == 227 || code == 228))
                                pflag = 1;
                        else if (!pflag && code == 229)
                                pflag = 100;
                        if (dig > 4 && pflag == 1 && isdigit(c))
                                pflag = 2;
                        if (pflag == 2) {
                                if (c != '\r' && c != ')') {
                                        if (pt < &pasv[sizeof(pasv) - 1])
                                                *pt++ = c;
                                } else {
                                        *pt = '\0';
                                        pflag = 3;
                                }
                        }
                        if (pflag == 100 && c == '(')
                                pflag = 2;
                        if (dig == 4 && c == '-') {
                                if (continuation)
                                        code = 0;
                                continuation++;
                        }
                        if (n == 0)
                                n = c;
                        if (cp < &current_line[sizeof(current_line) - 1])
                                *cp++ = c;
                }
                if (verbose > 0 || ((verbose > -1 && n == '5') &&
                    (n < '5' || !retry_connect))) {
                        (void)putc(c, ttyout);
                        (void)fflush(ttyout);
                }
                if (cp[-1] == '\r')
                        cp[-1] = '\0';
                *cp = '\0';
                if (lineno == 0)
                        (void)strlcpy(reply_string, current_line,
                            sizeof(reply_string));
                if (lineno > 0 && code == 0 && reply_callback != NULL)
                        (*reply_callback)(current_line);
                if (continuation && code != originalcode) {
                        if (originalcode == 0)
                                originalcode = code;
                        continue;
                }
                if (n != '1')
                        cpend = 0;
                alarmtimer(0);
                (void)xsignal(SIGINT, oldsigint);
                (void)xsignal(SIGALRM, oldsigalrm);
                if (code == 421 || originalcode == 421)
                        lostpeer(0);
                if (abrtflag && oldsigint != cmdabort &&
                    issighandler(oldsigint)) {
                        (*oldsigint)(SIGINT);
                }
                if (timeoutflag && oldsigalrm != cmdtimeout &&
                    issighandler(oldsigalrm)) {
                        (*oldsigalrm)(SIGINT);
                }
                return (n - '0');
        }
}

static int
empty(FILE *ecin, FILE *din, int sec)
{
        int             nr, nfd;
        struct pollfd   pfd[2];

        nfd = 0;
        if (ecin) {
                pfd[nfd].fd = fileno(ecin);
                pfd[nfd++].events = POLLIN;
        }

        if (din) {
                pfd[nfd].fd = fileno(din);
                pfd[nfd++].events = POLLIN;
        }

        if ((nr = ftp_poll(pfd, nfd, sec * 1000)) <= 0)
                return nr;

        nr = 0;
        nfd = 0;
        if (ecin)
                nr |= (pfd[nfd++].revents & POLLIN) ? 1 : 0;
        if (din)
                nr |= (pfd[nfd++].revents & POLLIN) ? 2 : 0;
        return nr;
}

static sigjmp_buf       xferabort;

__dead static void
abortxfer(int notused __unused)
{
        char msgbuf[100];
        size_t len;

        sigint_raised = 1;
        alarmtimer(0);
        mflag = 0;
        abrtflag = 0;
        switch (direction[0]) {
        case 'r':
                strlcpy(msgbuf, "\nreceive", sizeof(msgbuf));
                break;
        case 's':
                strlcpy(msgbuf, "\nsend", sizeof(msgbuf));
                break;
        default:
                errx(1, "abortxfer: unknown direction `%s'", direction);
        }
        len = strlcat(msgbuf, " aborted. Waiting for remote to finish abort.\n",
            sizeof(msgbuf));
        write(fileno(ttyout), msgbuf, len);
        siglongjmp(xferabort, 1);
}

/*
 * Read data from infd & write to outfd, using buf/bufsize as the temporary
 * buffer, dealing with short reads or writes.
 * If rate_limit != 0, rate-limit the transfer.
 * If hash_interval != 0, putc('c', ttyout) every hash_interval bytes.
 * Updates global variables: bytes.
 * Returns 0 if ok, 1 if there was a read error, 2 if there was a write error.
 * In the case of error, errno contains the appropriate error code.
 */
static int
copy_bytes(int infd, int outfd, char *buf, size_t bufsize,
        int rate_limit, int hash_interval)
{
        volatile off_t  hashc;
        ssize_t         inc, outc;
        char            *bufp;
        struct timeval  tvthen, tvnow, tvdiff;
        off_t           bufrem, bufchunk;
        int             serr;

        hashc = hash_interval;
        if (rate_limit)
                bufchunk = rate_limit;
        else
                bufchunk = bufsize;

        for (;;) {
                if (rate_limit) {
                        (void)gettimeofday(&tvthen, NULL);
                }
                errno = 0;
                inc = outc = 0;
                                        /* copy bufchunk at a time */
                bufrem = bufchunk;
                while (bufrem > 0) {
                        inc = read(infd, buf, MIN((off_t)bufsize, bufrem));
                        if (inc < 0) {
                                if (errno == EINTR || errno == EAGAIN) {
                                        continue;
                                }
                                goto copy_done;
                        } else if (inc == 0) {
                                goto copy_done;
                        }
                        bytes += inc;
                        bufrem -= inc;
                        bufp = buf;
                        while (inc > 0) {
                                outc = write(outfd, bufp, inc);
                                if (outc < 0) {
                                        if (errno == EINTR || errno == EAGAIN) {
                                                continue;
                                        }
                                        goto copy_done;
                                }
                                inc -= outc;
                                bufp += outc;
                        }
                        if (hash_interval) {
                                while (bytes >= hashc) {
                                        (void)putc('#', ttyout);
                                        hashc += hash_interval;
                                }
                                (void)fflush(ttyout);
                        }
                }
                if (rate_limit) {       /* rate limited; wait if necessary */
                        for (;;) {
                                (void)gettimeofday(&tvnow, NULL);
                                timersub(&tvnow, &tvthen, &tvdiff);
                                if (tvdiff.tv_sec > 0)
                                        break;
                                usleep(1000000 - tvdiff.tv_usec);
                        }
                }
        }

 copy_done:
        serr = errno;
        if (hash_interval && bytes > 0) {
                if (bytes < hash_interval)
                        (void)putc('#', ttyout);
                (void)putc('\n', ttyout);
                (void)fflush(ttyout);
        }
        errno = serr;
        if (inc == -1)
                return 1;
        if (outc == -1)
                return 2;

        return 0;
}

void
sendrequest(const char *cmd, const char *local, const char *remote,
            int printnames)
{
        struct stat st;
        int c;
        FILE *volatile fin;
        int fin_errno = 0;
        FILE *volatile dout;
        int dout_errno = 0;
        int (*volatile closefunc)(FILE *);
        sigfunc volatile oldintr;
        sigfunc volatile oldpipe;
        off_t volatile hashbytes;
        int hash_interval;
        const char *lmode;
        static size_t bufsize;
        static char *buf;
        int oprogress;

        hashbytes = mark;
        direction = "sent";
        dout = NULL;
        bytes = 0;
        filesize = -1;
        oprogress = progress;
        if (verbose && printnames) {
                if (*local != '-')
                        fprintf(ttyout, "local: %s ", local);
                if (remote)
                        fprintf(ttyout, "remote: %s\n", remote);
        }
        if (proxy) {
                proxtrans(cmd, local, remote);
                return;
        }
        if (curtype != type)
                changetype(type, 0);
        closefunc = NULL;
        oldintr = SIG_ERR;
        oldpipe = SIG_ERR;
        lmode = "w";
        if (sigsetjmp(xferabort, 1)) {
                while (cpend)
                        (void)getreply(0);
                code = -1;
                goto cleanupsend;
        }
        (void)xsignal(SIGQUIT, psummary);
        oldintr = xsignal(SIGINT, abortxfer);
        if (strcmp(local, "-") == 0) {
                fin = stdin;
                progress = 0;
        } else if (*local == '|') {
                oldpipe = xsignal(SIGPIPE, SIG_IGN);
                fin = popen(local + 1, "r");
                if (fin == NULL) {
                        warn("Can't execute `%s'", local + 1);
                        code = -1;
                        goto cleanupsend;
                }
                progress = 0;
                closefunc = pclose;
        } else {
                fin = fopen(local, "r");
                if (fin == NULL) {
                        warn("Can't open `%s'", local);
                        code = -1;
                        goto cleanupsend;
                }
                closefunc = fclose;
                if (fstat(fileno(fin), &st) < 0 || !S_ISREG(st.st_mode)) {
                        fprintf(ttyout, "%s: not a plain file.\n", local);
                        code = -1;
                        goto cleanupsend;
                }
                filesize = st.st_size;
        }
        if (initconn()) {
                code = -1;
                goto cleanupsend;
        }
        if (sigsetjmp(xferabort, 1))
                goto abort;

        if (restart_point &&
            (strcmp(cmd, "STOR") == 0 || strcmp(cmd, "APPE") == 0)) {
                off_t rc;

                rc = -1;
                switch (curtype) {
                case TYPE_A:
                        rc = fseeko(fin, restart_point, SEEK_SET);
                        break;
                case TYPE_I:
                case TYPE_L:
                        rc = lseek(fileno(fin), restart_point, SEEK_SET);
                        break;
                }
                if (rc < 0) {
                        warn("Can't seek to restart `%s'", local);
                        goto cleanupsend;
                }
                if (command("REST " LLF, (LLT)restart_point) != CONTINUE)
                        goto cleanupsend;
                lmode = "r+";
        }
        if (remote) {
                if (command("%s %s", cmd, remote) != PRELIM)
                        goto cleanupsend;
        } else {
                if (command("%s", cmd) != PRELIM)
                        goto cleanupsend;
        }
        dirchange = 1;
        dout = dataconn(lmode);
        if (dout == NULL)
                goto abort;

                        /* Resize buf to clamped sndbuf_size */
        if (bufsize == 0 || (size_t)sndbuf_size != bufsize) {
                if (buf)
                        (void)free(buf);
                if (sndbuf_size == 0)
                        bufsize = XFERBUFMAX;
                else
                        bufsize = MAX(XFERBUFMIN, MIN(sndbuf_size, XFERBUFMAX));
                buf = ftp_malloc(bufsize);
                DPRINTF("resized buf to bufsize %zu using sndbuf_size %d\n",
                    bufsize, sndbuf_size);
        }

        progressmeter(-1);
        if (oldpipe == SIG_ERR) {
                oldpipe = xsignal(SIGPIPE, SIG_IGN);
        }
        hash_interval = (hash && (!progress || filesize < 0)) ? mark : 0;

        switch (curtype) {

        case TYPE_I:
        case TYPE_L:
                c = copy_bytes(fileno(fin), fileno(dout), buf, bufsize,
                               rate_put, hash_interval);
                if (c == 1) {
                        warn("Reading `%s'", local);
                } else if (c == 2) {
                        if (errno != EPIPE)
                                warn("Writing to network");
                        bytes = -1;
                }
                break;

        case TYPE_A:
                while ((c = ftp_getc(fin, &fin_errno)) != EOF) {
                        if (c == '\n') {
                                while (hash_interval && bytes >= hashbytes) {
                                        (void)putc('#', ttyout);
                                        (void)fflush(ttyout);
                                        hashbytes += mark;
                                }
                                if (ftp_putc('\r', dout, &dout_errno) == EOF
                                    || ferror(dout))
                                        break;
                                bytes++;
                        }
                        if (ftp_putc(c, dout, &dout_errno) == EOF
                            || ferror(dout))
                                break;
                        bytes++;
                }
                if (hash_interval) {
                        if (bytes < hashbytes)
                                (void)putc('#', ttyout);
                        (void)putc('\n', ttyout);
                }
                if (ferror(fin)) {
                        errno = fin_errno;
                        warn("Reading `%s'", local);
                }
                if (ferror(dout)) {
                        errno = dout_errno;
                        if (errno != EPIPE)
                                warn("Writing to network");
                        bytes = -1;
                }
                break;
        }

        progressmeter(1);
        if (closefunc != NULL) {
                (*closefunc)(fin);
                fin = NULL;
        }
        (void)fclose(dout);
        dout = NULL;
        (void)getreply(0);
        if (bytes > 0)
                ptransfer(0);
        goto cleanupsend;

 abort:
        (void)xsignal(SIGINT, oldintr);
        oldintr = SIG_ERR;
        if (!cpend) {
                code = -1;
                goto cleanupsend;
        }
        if (data >= 0) {
                (void)close(data);
                data = -1;
        }
        if (dout) {
                (void)fclose(dout);
                dout = NULL;
        }
        (void)getreply(0);
        code = -1;
        if (bytes > 0)
                ptransfer(0);

 cleanupsend:
        if (oldintr != SIG_ERR)
                (void)xsignal(SIGINT, oldintr);
        if (oldpipe != SIG_ERR)
                (void)xsignal(SIGPIPE, oldpipe);
        if (data >= 0) {
                (void)close(data);
                data = -1;
        }
        if (closefunc != NULL && fin != NULL)
                (*closefunc)(fin);
        if (dout)
                (void)fclose(dout);
        progress = oprogress;
        restart_point = 0;
        bytes = 0;
}

void
recvrequest(const char *cmd, char *volatile local, const char *remote,
            const char *lmode, int printnames, int ignorespecial)
{
        FILE *volatile fout;
        int fout_errno = 0;
        FILE *volatile din;
        int din_errno = 0;
        int (*volatile closefunc)(FILE *);
        sigfunc volatile oldintr;
        sigfunc volatile oldpipe;
        int c, d;
        int volatile is_retr;
        int volatile tcrflag;
        int volatile bare_lfs;
        static size_t bufsize;
        static char *buf;
        off_t volatile hashbytes;
        int hash_interval;
        struct stat st;
        time_t mtime;
        struct timeval tval[2];
        int oprogress;
        int opreserve;

        fout = NULL;
        din = NULL;
        hashbytes = mark;
        direction = "received";
        bytes = 0;
        bare_lfs = 0;
        filesize = -1;
        oprogress = progress;
        opreserve = preserve;
        is_retr = (strcmp(cmd, "RETR") == 0);
        if (is_retr && verbose && printnames) {
                if (ignorespecial || *local != '-')
                        fprintf(ttyout, "local: %s ", local);
                if (remote)
                        fprintf(ttyout, "remote: %s\n", remote);
        }
        if (proxy && is_retr) {
                proxtrans(cmd, local, remote);
                return;
        }
        closefunc = NULL;
        oldintr = SIG_ERR;
        oldpipe = SIG_ERR;
        tcrflag = !crflag && is_retr;
        if (sigsetjmp(xferabort, 1)) {
                while (cpend)
                        (void)getreply(0);
                code = -1;
                goto cleanuprecv;
        }
        (void)xsignal(SIGQUIT, psummary);
        oldintr = xsignal(SIGINT, abortxfer);
        if (ignorespecial || (strcmp(local, "-") && *local != '|')) {
                if (access(local, W_OK) < 0) {
                        char *dir = strrchr(local, '/');

                        if (errno != ENOENT && errno != EACCES) {
                                warn("Can't access `%s'", local);
                                code = -1;
                                goto cleanuprecv;
                        }
                        if (dir != NULL)
                                *dir = 0;
                        d = access(dir == local ? "/" :
                            dir ? local : ".", W_OK);
                        if (dir != NULL)
                                *dir = '/';
                        if (d < 0) {
                                warn("Can't access `%s'", local);
                                code = -1;
                                goto cleanuprecv;
                        }
                        if (!runique && errno == EACCES &&
                            chmod(local, (S_IRUSR|S_IWUSR)) < 0) {
                                warn("Can't chmod `%s'", local);
                                code = -1;
                                goto cleanuprecv;
                        }
                        if (runique && errno == EACCES &&
                           (local = gunique(local)) == NULL) {
                                code = -1;
                                goto cleanuprecv;
                        }
                }
                else if (runique && (local = gunique(local)) == NULL) {
                        code = -1;
                        goto cleanuprecv;
                }
        }
        if (!is_retr) {
                if (curtype != TYPE_A)
                        changetype(TYPE_A, 0);
        } else {
                if (curtype != type)
                        changetype(type, 0);
                filesize = remotesize(remote, 0);
                if (code == 421 || code == -1)
                        goto cleanuprecv;
        }
        if (initconn()) {
                code = -1;
                goto cleanuprecv;
        }
        if (sigsetjmp(xferabort, 1))
                goto abort;
        if (is_retr && restart_point &&
            command("REST " LLF, (LLT) restart_point) != CONTINUE)
                goto cleanuprecv;
        if (! EMPTYSTRING(remote)) {
                if (command("%s %s", cmd, remote) != PRELIM)
                        goto cleanuprecv;
        } else {
                if (command("%s", cmd) != PRELIM)
                        goto cleanuprecv;
        }
        din = dataconn("r");
        if (din == NULL)
                goto abort;
        if (!ignorespecial && strcmp(local, "-") == 0) {
                fout = stdout;
                progress = 0;
                preserve = 0;
        } else if (!ignorespecial && *local == '|') {
                oldpipe = xsignal(SIGPIPE, SIG_IGN);
                fout = popen(local + 1, "w");
                if (fout == NULL) {
                        warn("Can't execute `%s'", local+1);
                        goto abort;
                }
                progress = 0;
                preserve = 0;
                closefunc = pclose;
        } else {
                fout = fopen(local, lmode);
                if (fout == NULL) {
                        warn("Can't open `%s'", local);
                        goto abort;
                }
                closefunc = fclose;
        }

        if (fstat(fileno(fout), &st) != -1 && !S_ISREG(st.st_mode)) {
                progress = 0;
                preserve = 0;
        }

                        /* Resize buf to clamped rcvbuf_size */
        if (bufsize == 0 || (size_t)rcvbuf_size != bufsize) {
                if (buf)
                        (void)free(buf);
                if (rcvbuf_size == 0)
                        bufsize = XFERBUFMAX;
                else
                        bufsize = MAX(XFERBUFMIN, MIN(rcvbuf_size, XFERBUFMAX));
                buf = ftp_malloc(bufsize);
                DPRINTF("resized buf to bufsize %zu using rcvbuf_size %d\n",
                    bufsize, rcvbuf_size);
        }

        progressmeter(-1);
        hash_interval = (hash && (!progress || filesize < 0)) ? mark : 0;

        switch (curtype) {

        case TYPE_I:
        case TYPE_L:
                if (is_retr && restart_point &&
                    lseek(fileno(fout), restart_point, SEEK_SET) < 0) {
                        warn("Can't seek to restart `%s'", local);
                        goto cleanuprecv;
                }
                c = copy_bytes(fileno(din), fileno(fout), buf, bufsize,
                               rate_get, hash_interval);
                if (c == 1) {
                        if (errno != EPIPE)
                                warn("Reading from network");
                        bytes = -1;
                } else if (c == 2) {
                        warn("Writing `%s'", local);
                }
                break;

        case TYPE_A:
                if (is_retr && restart_point) {
                        int ch;
                        off_t i;

                        if (fseeko(fout, (off_t)0, SEEK_SET) < 0)
                                goto done;
                        for (i = 0; i++ < restart_point;) {
                                if ((ch = ftp_getc(fout, &fout_errno)) == EOF)
                                        goto done;
                                if (ch == '\n')
                                        i++;
                        }
                        if (fseeko(fout, (off_t)0, SEEK_CUR) < 0) {
 done:
                                warn("Can't seek to restart `%s'", local);
                                goto cleanuprecv;
                        }
                }
                while ((c = ftp_getc(din, &din_errno)) != EOF) {
                        if (c == '\n')
                                bare_lfs++;
                        while (c == '\r') {
                                while (hash_interval && bytes >= hashbytes) {
                                        (void)putc('#', ttyout);
                                        (void)fflush(ttyout);
                                        hashbytes += mark;
                                }
                                bytes++;
                                if ((c = ftp_getc(din, &din_errno)) != '\n'
                                    || tcrflag) {
                                        if (ftp_putc('\r', fout, &fout_errno) == EOF
                                            || ferror(fout)) {
                                                goto break2;
                                        }
                                        if (c == '\0') {
                                                bytes++;
                                                goto contin2;
                                        }
                                        if (c == EOF)
                                                goto contin2;
                                }
                        }
                        if (ftp_putc(c, fout, &fout_errno) == EOF)
                                break;
                        bytes++;
        contin2:        ;
                }
 break2:
                if (hash_interval) {
                        if (bytes < hashbytes)
                                (void)putc('#', ttyout);
                        (void)putc('\n', ttyout);
                }
                if (ferror(din)) {
                        errno = din_errno;
                        if (errno != EPIPE)
                                warn("Reading from network");
                        bytes = -1;
                }
                if (ferror(fout)) {
                        errno = fout_errno;
                        warn("Writing `%s'", local);
                }
                break;
        }

        progressmeter(1);
        if (closefunc != NULL) {
                (*closefunc)(fout);
                fout = NULL;
        }
        (void)fclose(din);
        din = NULL;
        (void)getreply(0);
        if (bare_lfs) {
                fprintf(ttyout,
                    "WARNING! %d bare linefeeds received in ASCII mode.\n",
                    bare_lfs);
                fputs("File may not have transferred correctly.\n", ttyout);
        }
        if (bytes >= 0 && is_retr) {
                if (bytes > 0)
                        ptransfer(0);
                if (preserve && (closefunc == fclose)) {
                        mtime = remotemodtime(remote, 0);
                        if (mtime != -1) {
                                (void)gettimeofday(&tval[0], NULL);
                                tval[1].tv_sec = mtime;
                                tval[1].tv_usec = 0;
                                if (utimes(local, tval) == -1) {
                                        fprintf(ttyout,
                                "Can't change modification time on %s to %s",
                                            local,
                                            rfc2822time(localtime(&mtime)));
                                }
                        }
                }
        }
        goto cleanuprecv;

 abort:
                        /*
                         * abort using RFC 959 recommended IP,SYNC sequence
                         */
        if (! sigsetjmp(xferabort, 1)) {
                        /* this is the first call */
                (void)xsignal(SIGINT, abort_squared);
                if (!cpend) {
                        code = -1;
                        goto cleanuprecv;
                }
                abort_remote(din);
        }
        code = -1;
        if (bytes > 0)
                ptransfer(0);

 cleanuprecv:
        if (oldintr != SIG_ERR)
                (void)xsignal(SIGINT, oldintr);
        if (oldpipe != SIG_ERR)
                (void)xsignal(SIGPIPE, oldpipe);
        if (data >= 0) {
                (void)close(data);
                data = -1;
        }
        if (closefunc != NULL && fout != NULL)
                (*closefunc)(fout);
        if (din)
                (void)fclose(din);
        progress = oprogress;
        preserve = opreserve;
        bytes = 0;
}

/*
 * Need to start a listen on the data channel before we send the command,
 * otherwise the server's connect may fail.
 */
int
initconn(void)
{
        char *p, *a;
        int result, tmpno = 0;
        int on = 1;
        int error;
        unsigned int addr[16], port[2];
        unsigned int af, hal, pal;
        socklen_t len;
        const char *pasvcmd = NULL;
        int overbose;

#ifdef INET6
#ifndef NO_DEBUG
        if (myctladdr.su_family == AF_INET6 && ftp_debug &&
            (IN6_IS_ADDR_LINKLOCAL(&myctladdr.si_su.su_sin6.sin6_addr) ||
             IN6_IS_ADDR_SITELOCAL(&myctladdr.si_su.su_sin6.sin6_addr))) {
                warnx("Use of scoped addresses can be troublesome");
        }
#endif
#endif

 reinit:
        if (passivemode) {
                data_addr = myctladdr;
                data = socket(data_addr.su_family, SOCK_STREAM, 0);
                if (data < 0) {
                        warn("Can't create socket for data connection");
                        return (1);
                }
                if ((options & SO_DEBUG) &&
                    setsockopt(data, SOL_SOCKET, SO_DEBUG,
                                (void *)&on, sizeof(on)) == -1) {
                        DWARN("setsockopt %s (ignored)", "SO_DEBUG");
                }
                result = COMPLETE + 1;
                switch (data_addr.su_family) {
                case AF_INET:
                        if (epsv4 && !epsv4bad) {
                                pasvcmd = "EPSV";
                                overbose = verbose;
                                if (ftp_debug == 0)
                                        verbose = -1;
                                result = command("EPSV");
                                verbose = overbose;
                                if (verbose > 0 &&
                                    (result == COMPLETE || !connected))
                                        fprintf(ttyout, "%s\n", reply_string);
                                if (!connected)
                                        return (1);
                                /*
                                 * this code is to be friendly with broken
                                 * BSDI ftpd
                                 */
                                if (code / 10 == 22 && code != 229) {
                                        fputs(
"wrong server: return code must be 229\n",
                                                ttyout);
                                        result = COMPLETE + 1;
                                }
                                if (result != COMPLETE) {
                                        epsv4bad = 1;
                                        DPRINTF("disabling epsv4 for this "
                                            "connection\n");
                                }
                        }
                        if (result != COMPLETE) {
                                pasvcmd = "PASV";
                                result = command("PASV");
                                if (!connected)
                                        return (1);
                        }
                        break;
#ifdef INET6
                case AF_INET6:
                        if (epsv6 && !epsv6bad) {
                                pasvcmd = "EPSV";
                                overbose = verbose;
                                if (ftp_debug == 0)
                                        verbose = -1;
                                result = command("EPSV");
                                verbose = overbose;
                                if (verbose > 0 &&
                                    (result == COMPLETE || !connected))
                                        fprintf(ttyout, "%s\n", reply_string);
                                if (!connected)
                                        return (1);
                                /*
                                 * this code is to be friendly with
                                 * broken BSDI ftpd
                                 */
                                if (code / 10 == 22 && code != 229) {
                                        fputs(
                                                "wrong server: return code must be 229\n",
                                                ttyout);
                                        result = COMPLETE + 1;
                                }
                                if (result != COMPLETE) {
                                        epsv6bad = 1;
                                        DPRINTF("disabling epsv6 for this "
                                            "connection\n");
                                }
                        }
                        if (result != COMPLETE) {
                                pasvcmd = "LPSV";
                                result = command("LPSV");
                        }
                        if (!connected)
                                return (1);
                        break;
#endif
                default:
                        result = COMPLETE + 1;
                        break;
                }
                if (result != COMPLETE) {
                        if (activefallback) {
                                (void)close(data);
                                data = -1;
                                passivemode = 0;
#if 0
                                activefallback = 0;
#endif
                                goto reinit;
                        }
                        fputs("Passive mode refused.\n", ttyout);
                        goto bad;
                }

#define pack2(var, off) \
        (((var[(off) + 0] & 0xff) << 8) | ((var[(off) + 1] & 0xff) << 0))
#define pack4(var, off) \
        (((var[(off) + 0] & 0xff) << 24) | ((var[(off) + 1] & 0xff) << 16) | \
         ((var[(off) + 2] & 0xff) << 8) | ((var[(off) + 3] & 0xff) << 0))
#define UC(b)   (((int)b)&0xff)

                /*
                 * What we've got at this point is a string of comma separated
                 * one-byte unsigned integer values, separated by commas.
                 */
                if (strcmp(pasvcmd, "PASV") == 0) {
                        if (data_addr.su_family != AF_INET) {
                                fputs(
    "Passive mode AF mismatch. Shouldn't happen!\n", ttyout);
                                goto bad;
                        }
                        if (code / 10 == 22 && code != 227) {
                                fputs("wrong server: return code must be 227\n",
                                        ttyout);
                                goto bad;
                        }
                        error = sscanf(pasv, "%u,%u,%u,%u,%u,%u",
                                        &addr[0], &addr[1], &addr[2], &addr[3],
                                        &port[0], &port[1]);
                        if (error != 6) {
                                fputs(
"Passive mode address scan failure. Shouldn't happen!\n", ttyout);
                                goto bad;
                        }
                        memset(&data_addr, 0, sizeof(data_addr));
                        data_addr.su_family = AF_INET;
                        data_addr.su_len = sizeof(struct sockaddr_in);
                        data_addr.si_su.su_sin.sin_addr.s_addr =
                            htonl(pack4(addr, 0));
                        data_addr.su_port = htons(pack2(port, 0));
                        if (data_addr.si_su.su_sin.sin_addr.s_addr !=
                            hisctladdr.si_su.su_sin.sin_addr.s_addr) {
                                fputs("Passive mode address mismatch.\n",
                                    ttyout);
                                goto bad;
                        }
                } else if (strcmp(pasvcmd, "LPSV") == 0) {
                        if (code / 10 == 22 && code != 228) {
                                fputs("wrong server: return code must be 228\n",
                                        ttyout);
                                goto bad;
                        }
                        switch (data_addr.su_family) {
                        case AF_INET:
                                error = sscanf(pasv,
"%u,%u,%u,%u,%u,%u,%u,%u,%u",
                                        &af, &hal,
                                        &addr[0], &addr[1], &addr[2], &addr[3],
                                        &pal, &port[0], &port[1]);
                                if (error != 9) {
                                        fputs(
"Passive mode address scan failure. Shouldn't happen!\n", ttyout);
                                        goto bad;
                                }
                                if (af != 4 || hal != 4 || pal != 2) {
                                        fputs(
"Passive mode AF mismatch. Shouldn't happen!\n", ttyout);
                                        goto bad;
                                }

                                memset(&data_addr, 0, sizeof(data_addr));
                                data_addr.su_family = AF_INET;
                                data_addr.su_len = sizeof(struct sockaddr_in);
                                data_addr.si_su.su_sin.sin_addr.s_addr =
                                    htonl(pack4(addr, 0));
                                data_addr.su_port = htons(pack2(port, 0));
                                if (data_addr.si_su.su_sin.sin_addr.s_addr !=
                                    hisctladdr.si_su.su_sin.sin_addr.s_addr) {
                                        fputs("Passive mode address mismatch.\n",
                                            ttyout);
                                        goto bad;
                                }
                                break;
#ifdef INET6
                        case AF_INET6:
                                error = sscanf(pasv,
"%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u",
                                        &af, &hal,
                                        &addr[0], &addr[1], &addr[2], &addr[3],
                                        &addr[4], &addr[5], &addr[6], &addr[7],
                                        &addr[8], &addr[9], &addr[10],
                                        &addr[11], &addr[12], &addr[13],
                                        &addr[14], &addr[15],
                                        &pal, &port[0], &port[1]);
                                if (error != 21) {
                                        fputs(
"Passive mode address scan failure. Shouldn't happen!\n", ttyout);
                                        goto bad;
                                }
                                if (af != 6 || hal != 16 || pal != 2) {
                                        fputs(
"Passive mode AF mismatch. Shouldn't happen!\n", ttyout);
                                        goto bad;
                                }

                                memset(&data_addr, 0, sizeof(data_addr));
                                data_addr.su_family = AF_INET6;
                                data_addr.su_len = sizeof(struct sockaddr_in6);
                            {
                                size_t i;
                                for (i = 0; i < sizeof(struct in6_addr); i++) {
                                        data_addr.si_su.su_sin6.sin6_addr.s6_addr[i] =
                                            UC(addr[i]);
                                }
                            }
                                data_addr.su_port = htons(pack2(port, 0));
                                if (memcmp(
                                    &data_addr.si_su.su_sin6.sin6_addr,
                                    &hisctladdr.si_su.su_sin6.sin6_addr,
                                    sizeof(data_addr.si_su.su_sin6.sin6_addr))) {
                                        fputs("Passive mode address mismatch.\n",
                                            ttyout);
                                        goto bad;
                                }
                                break;
#endif
                        default:
                                fputs("Unknown passive mode AF.\n", ttyout);
                                goto bad;
                        }
                } else if (strcmp(pasvcmd, "EPSV") == 0) {
                        char delim[4];

                        port[0] = 0;
                        if (code / 10 == 22 && code != 229) {
                                fputs("wrong server: return code must be 229\n",
                                        ttyout);
                                goto bad;
                        }
                        if (sscanf(pasv, "%c%c%c%d%c", &delim[0],
                                        &delim[1], &delim[2], &port[1],
                                        &delim[3]) != 5) {
                                fputs("parse error!\n", ttyout);
                                goto bad;
                        }
                        if (delim[0] != delim[1] || delim[0] != delim[2]
                         || delim[0] != delim[3]) {
                                fputs("parse error!\n", ttyout);
                                goto bad;
                        }
                        data_addr = hisctladdr;
                        data_addr.su_port = htons(port[1]);
                } else
                        goto bad;

                if (ftp_connect(data, (struct sockaddr *)(void *)&data_addr.si_su,
                    data_addr.su_len, 1) < 0) {
                        if (activefallback) {
                                (void)close(data);
                                data = -1;
                                passivemode = 0;
#if 0
                                activefallback = 0;
#endif
                                goto reinit;
                        }
                        goto bad;
                }
#ifdef IPTOS_THROUGHPUT
                if (data_addr.su_family == AF_INET) {
                        on = IPTOS_THROUGHPUT;
                        if (setsockopt(data, IPPROTO_IP, IP_TOS,
                                        (void *)&on, sizeof(on)) == -1) {
                                DWARN("setsockopt %s (ignored)",
                                    "IPTOS_THROUGHPUT");
                        }
                }
#endif
                return (0);
        }

 noport:
        data_addr = myctladdr;
        if (sendport)
                data_addr.su_port = 0;  /* let system pick one */
        if (data != -1)
                (void)close(data);
        data = socket(data_addr.su_family, SOCK_STREAM, 0);
        if (data < 0) {
                warn("Can't create socket for data connection");
                if (tmpno)
                        sendport = 1;
                return (1);
        }
        if (!sendport)
                if (setsockopt(data, SOL_SOCKET, SO_REUSEADDR,
                                (void *)&on, sizeof(on)) == -1) {
                        warn("Can't set SO_REUSEADDR on data connection");
                        goto bad;
                }
        if (bind(data, (struct sockaddr *)(void *)&data_addr.si_su,
            data_addr.su_len) < 0) {
                warn("Can't bind for data connection");
                goto bad;
        }
        if ((options & SO_DEBUG) &&
            setsockopt(data, SOL_SOCKET, SO_DEBUG,
                        (void *)&on, sizeof(on)) == -1) {
                DWARN("setsockopt %s (ignored)", "SO_DEBUG");
        }
        len = sizeof(data_addr.si_su);
        memset((char *)&data_addr, 0, sizeof (data_addr));
        if (getsockname(data, (struct sockaddr *)(void *)&data_addr.si_su, &len) == -1) {
                warn("Can't determine my address of data connection");
                goto bad;
        }
        data_addr.su_len = len;
        if (ftp_listen(data, 1) < 0)
                warn("Can't listen to data connection");

        if (sendport) {
                char hname[NI_MAXHOST], sname[NI_MAXSERV];
                struct sockinet tmp;

                switch (data_addr.su_family) {
                case AF_INET:
                        if (!epsv4 || epsv4bad) {
                                result = COMPLETE + 1;
                                break;
                        }
#ifdef INET6
                        /* FALLTHROUGH */
                case AF_INET6:
                        if (!epsv6 || epsv6bad) {
                                result = COMPLETE + 1;
                                break;
                        }
#endif
                        af = (data_addr.su_family == AF_INET) ? 1 : 2;
                        tmp = data_addr;
#ifdef INET6
                        if (tmp.su_family == AF_INET6)
                                tmp.si_su.su_sin6.sin6_scope_id = 0;
#endif
                        if (getnameinfo((struct sockaddr *)(void *)&tmp.si_su,
                            tmp.su_len, hname, sizeof(hname), sname,
                            sizeof(sname), NI_NUMERICHOST | NI_NUMERICSERV)) {
                                result = ERROR;
                        } else {
                                overbose = verbose;
                                if (ftp_debug == 0)
                                        verbose = -1;
                                result = command("EPRT |%u|%s|%s|", af, hname,
                                    sname);
                                verbose = overbose;
                                if (verbose > 0 &&
                                    (result == COMPLETE || !connected))
                                        fprintf(ttyout, "%s\n", reply_string);
                                if (!connected)
                                        return (1);
                                if (result != COMPLETE) {
                                        epsv4bad = 1;
                                        DPRINTF("disabling epsv4 for this "
                                            "connection\n");
                                }
                        }
                        break;
                default:
                        result = COMPLETE + 1;
                        break;
                }
                if (result == COMPLETE)
                        goto skip_port;

                switch (data_addr.su_family) {
                case AF_INET:
                        a = (char *)&data_addr.si_su.su_sin.sin_addr;
                        p = (char *)&data_addr.su_port;
                        result = command("PORT %d,%d,%d,%d,%d,%d",
                                 UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
                                 UC(p[0]), UC(p[1]));
                        break;
#ifdef INET6
                case AF_INET6: {
                        uint8_t ua[sizeof(data_addr.si_su.su_sin6.sin6_addr)];
                        uint8_t up[sizeof(data_addr.su_port)];

                        memcpy(ua, &data_addr.si_su.su_sin6.sin6_addr,
                            sizeof(ua));
                        memcpy(up, &data_addr.su_port, sizeof(up));
                        
                        result = command(
        "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
                                 6, 16,
                                  ua[0],  ua[1],  ua[2],  ua[3],
                                  ua[4],  ua[5],  ua[6],  ua[7],
                                  ua[8],  ua[9], ua[10], ua[11],
                                 ua[12], ua[13], ua[14], ua[15],
                                 2,
                                 up[0], up[1]);
                        break;
                }
#endif
                default:
                        result = COMPLETE + 1; /* xxx */
                }
                if (!connected)
                        return (1);
        skip_port:

                if (result == ERROR && sendport == -1) {
                        sendport = 0;
                        tmpno = 1;
                        goto noport;
                }
                return (result != COMPLETE);
        }
        if (tmpno)
                sendport = 1;
#ifdef IPTOS_THROUGHPUT
        if (data_addr.su_family == AF_INET) {
                on = IPTOS_THROUGHPUT;
                if (setsockopt(data, IPPROTO_IP, IP_TOS,
                                (void *)&on, sizeof(on)) == -1) {
                        DWARN("setsockopt %s (ignored)", "IPTOS_THROUGHPUT");
                }
        }
#endif
        return (0);
 bad:
        (void)close(data);
        data = -1;
        if (tmpno)
                sendport = 1;
        return (1);
}

FILE *
dataconn(const char *lmode)
{
        struct sockinet from;
        int             s, flags, rv, timeout;
        struct timeval  endtime, now, td;
        struct pollfd   pfd[1];
        socklen_t       fromlen;

        if (passivemode)        /* passive data connection */
                return (fdopen(data, lmode));

                                /* active mode data connection */

        if ((flags = fcntl(data, F_GETFL, 0)) == -1)
                goto dataconn_failed;           /* get current socket flags  */
        if (fcntl(data, F_SETFL, flags | O_NONBLOCK) == -1)
                goto dataconn_failed;           /* set non-blocking connect */

                /* NOTE: we now must restore socket flags on successful exit */

                                /* limit time waiting on listening socket */
        pfd[0].fd = data;
        pfd[0].events = POLLIN;
        (void)gettimeofday(&endtime, NULL);     /* determine end time */
        endtime.tv_sec += (quit_time > 0) ? quit_time: 60;
                                                /* without -q, default to 60s */
        do {
                (void)gettimeofday(&now, NULL);
                timersub(&endtime, &now, &td);
                timeout = (int)(td.tv_sec * 1000 + td.tv_usec / 1000);
                if (timeout < 0)
                        timeout = 0;
                rv = ftp_poll(pfd, 1, timeout);
                        /* loop until poll !EINTR && !EAGAIN */
        } while (rv == -1 && (errno == EINTR || errno == EAGAIN));
        if (rv == -1) {
                warn("Can't poll waiting before accept");
                goto dataconn_failed;
        }
        if (rv == 0) {
                warnx("Poll timeout waiting before accept");
                goto dataconn_failed;
        }

                                /* (non-blocking) accept the connection */
        fromlen = myctladdr.su_len;
        do {
                s = accept(data, (struct sockaddr *)(void *)&from.si_su, &fromlen);
                        /* loop until accept !EINTR && !EAGAIN */
        } while (s == -1 && (errno == EINTR || errno == EAGAIN));
        if (s == -1) {
                warn("Can't accept data connection");
                goto dataconn_failed;
        }

        (void)close(data);
        data = s;
        if (fcntl(data, F_SETFL, flags) == -1)  /* restore socket flags */
                goto dataconn_failed;

#ifdef IPTOS_THROUGHPUT
        if (from.su_family == AF_INET) {
                int tos = IPTOS_THROUGHPUT;
                if (setsockopt(s, IPPROTO_IP, IP_TOS,
                                (void *)&tos, sizeof(tos)) == -1) {
                        DWARN("setsockopt %s (ignored)", "IPTOS_THROUGHPUT");
                }
        }
#endif
        return (fdopen(data, lmode));

 dataconn_failed:
        (void)close(data);
        data = -1;
        return (NULL);
}

void
psabort(int notused __unused)
{
        int oerrno = errno;

        sigint_raised = 1;
        alarmtimer(0);
        abrtflag++;
        errno = oerrno;
}

void
pswitch(int flag)
{
        sigfunc oldintr;
        static struct comvars {
                int connect;
                char name[MAXHOSTNAMELEN];
                struct sockinet mctl;
                struct sockinet hctl;
                FILE *in;
                FILE *out;
                int tpe;
                int curtpe;
                int cpnd;
                int sunqe;
                int runqe;
                int mcse;
                int ntflg;
                char nti[17];
                char nto[17];
                int mapflg;
                char mi[MAXPATHLEN];
                char mo[MAXPATHLEN];
        } proxstruct, tmpstruct;
        struct comvars *ip, *op;

        abrtflag = 0;
        oldintr = xsignal(SIGINT, psabort);
        if (flag) {
                if (proxy)
                        return;
                ip = &tmpstruct;
                op = &proxstruct;
                proxy++;
        } else {
                if (!proxy)
                        return;
                ip = &proxstruct;
                op = &tmpstruct;
                proxy = 0;
        }
        ip->connect = connected;
        connected = op->connect;
        if (hostname)
                (void)strlcpy(ip->name, hostname, sizeof(ip->name));
        else
                ip->name[0] = '\0';
        hostname = op->name;
        ip->hctl = hisctladdr;
        hisctladdr = op->hctl;
        ip->mctl = myctladdr;
        myctladdr = op->mctl;
        ip->in = cin;
        cin = op->in;
        ip->out = cout;
        cout = op->out;
        ip->tpe = type;
        type = op->tpe;
        ip->curtpe = curtype;
        curtype = op->curtpe;
        ip->cpnd = cpend;
        cpend = op->cpnd;
        ip->sunqe = sunique;
        sunique = op->sunqe;
        ip->runqe = runique;
        runique = op->runqe;
        ip->mcse = mcase;
        mcase = op->mcse;
        ip->ntflg = ntflag;
        ntflag = op->ntflg;
        (void)strlcpy(ip->nti, ntin, sizeof(ip->nti));
        (void)strlcpy(ntin, op->nti, sizeof(ntin));
        (void)strlcpy(ip->nto, ntout, sizeof(ip->nto));
        (void)strlcpy(ntout, op->nto, sizeof(ntout));
        ip->mapflg = mapflag;
        mapflag = op->mapflg;
        (void)strlcpy(ip->mi, mapin, sizeof(ip->mi));
        (void)strlcpy(mapin, op->mi, sizeof(mapin));
        (void)strlcpy(ip->mo, mapout, sizeof(ip->mo));
        (void)strlcpy(mapout, op->mo, sizeof(mapout));
        (void)xsignal(SIGINT, oldintr);
        if (abrtflag) {
                abrtflag = 0;
                (*oldintr)(SIGINT);
        }
}

__dead static void
abortpt(int notused __unused)
{

        sigint_raised = 1;
        alarmtimer(0);
        if (fromatty)
                write(fileno(ttyout), "\n", 1);
        ptabflg++;
        mflag = 0;
        abrtflag = 0;
        siglongjmp(ptabort, 1);
}

void
proxtrans(const char *cmd, const char *local, const char *remote)
{
        sigfunc volatile oldintr;
        int prox_type, nfnd;
        int volatile secndflag;
        const char *volatile cmd2;

        oldintr = SIG_ERR;
        secndflag = 0;
        if (strcmp(cmd, "RETR"))
                cmd2 = "RETR";
        else
                cmd2 = runique ? "STOU" : "STOR";
        if ((prox_type = type) == 0) {
                if (unix_server && unix_proxy)
                        prox_type = TYPE_I;
                else
                        prox_type = TYPE_A;
        }
        if (curtype != prox_type)
                changetype(prox_type, 1);
        if (command("PASV") != COMPLETE) {
                fputs("proxy server does not support third party transfers.\n",
                    ttyout);
                return;
        }
        pswitch(0);
        if (!connected) {
                fputs("No primary connection.\n", ttyout);
                pswitch(1);
                code = -1;
                return;
        }
        if (curtype != prox_type)
                changetype(prox_type, 1);
        if (command("PORT %s", pasv) != COMPLETE) {
                pswitch(1);
                return;
        }
        if (sigsetjmp(ptabort, 1))
                goto abort;
        oldintr = xsignal(SIGINT, abortpt);
        if ((restart_point &&
            (command("REST " LLF, (LLT) restart_point) != CONTINUE))
            || (command("%s %s", cmd, remote) != PRELIM)) {
                (void)xsignal(SIGINT, oldintr);
                pswitch(1);
                return;
        }
        sleep(2);
        pswitch(1);
        secndflag++;
        if ((restart_point &&
            (command("REST " LLF, (LLT) restart_point) != CONTINUE))
            || (command("%s %s", cmd2, local) != PRELIM))
                goto abort;
        ptflag++;
        (void)getreply(0);
        pswitch(0);
        (void)getreply(0);
        (void)xsignal(SIGINT, oldintr);
        pswitch(1);
        ptflag = 0;
        fprintf(ttyout, "local: %s remote: %s\n", local, remote);
        return;
 abort:
        if (sigsetjmp(xferabort, 1)) {
                (void)xsignal(SIGINT, oldintr);
                return;
        }
        (void)xsignal(SIGINT, abort_squared);
        ptflag = 0;
        if (strcmp(cmd, "RETR") && !proxy)
                pswitch(1);
        else if (!strcmp(cmd, "RETR") && proxy)
                pswitch(0);
        if (!cpend && !secndflag) {  /* only here if cmd = "STOR" (proxy=1) */
                if (command("%s %s", cmd2, local) != PRELIM) {
                        pswitch(0);
                        if (cpend)
                                abort_remote(NULL);
                }
                pswitch(1);
                if (ptabflg)
                        code = -1;
                (void)xsignal(SIGINT, oldintr);
                return;
        }
        if (cpend)
                abort_remote(NULL);
        pswitch(!proxy);
        if (!cpend && !secndflag) {  /* only if cmd = "RETR" (proxy=1) */
                if (command("%s %s", cmd2, local) != PRELIM) {
                        pswitch(0);
                        if (cpend)
                                abort_remote(NULL);
                        pswitch(1);
                        if (ptabflg)
                                code = -1;
                        (void)xsignal(SIGINT, oldintr);
                        return;
                }
        }
        if (cpend)
                abort_remote(NULL);
        pswitch(!proxy);
        if (cpend) {
                if ((nfnd = empty(cin, NULL, 10)) <= 0) {
                        if (nfnd < 0)
                                warn("Error aborting proxy command");
                        if (ptabflg)
                                code = -1;
                        lostpeer(0);
                }
                (void)getreply(0);
                (void)getreply(0);
        }
        if (proxy)
                pswitch(0);
        pswitch(1);
        if (ptabflg)
                code = -1;
        (void)xsignal(SIGINT, oldintr);
}

void
reset(int argc, char *argv[])
{
        int nfnd = 1;

        if (argc == 0 && argv != NULL) {
                UPRINTF("usage: %s\n", argv[0]);
                code = -1;
                return;
        }
        while (nfnd > 0) {
                if ((nfnd = empty(cin, NULL, 0)) < 0) {
                        warn("Error resetting connection");
                        code = -1;
                        lostpeer(0);
                } else if (nfnd)
                        (void)getreply(0);
        }
}

char *
gunique(char *local)
{
        static char new[MAXPATHLEN];
        char *cp = strrchr(local, '/');
        int d, count = 0;
        size_t len;
        char ext = '1';

        if (cp)
                *cp = '\0';
        d = access(cp == local ? "/" : cp ? local : ".", W_OK);
        if (cp)
                *cp = '/';
        if (d < 0) {
                warn("Can't access `%s'", local);
                return (NULL);
        }
        len = strlcpy(new, local, sizeof(new));
        cp = &new[len];
        *cp++ = '.';
        while (!d) {
                if (++count == 100) {
                        fputs("runique: can't find unique file name.\n",
                            ttyout);
                        return (NULL);
                }
                *cp++ = ext;
                *cp = '\0';
                if (ext == '9')
                        ext = '0';
                else
                        ext++;
                if ((d = access(new, F_OK)) < 0)
                        break;
                if (ext != '0')
                        cp--;
                else if (*(cp - 2) == '.')
                        *(cp - 1) = '1';
                else {
                        *(cp - 2) = *(cp - 2) + 1;
                        cp--;
                }
        }
        return (new);
}

/*
 * abort_squared --
 *      aborts abort_remote(). lostpeer() is called because if the user is
 *      too impatient to wait or there's another problem then ftp really
 *      needs to get back to a known state.
 */
static void
abort_squared(int signo)
{
        char msgbuf[100];
        size_t len;

        sigint_raised = 1;
        alarmtimer(0);
        len = strlcpy(msgbuf, "\nremote abort aborted; closing connection.\n",
            sizeof(msgbuf));
        write(fileno(ttyout), msgbuf, len);
        lostpeer(signo);
        siglongjmp(xferabort, 1);
}

void
abort_remote(FILE *din)
{
        unsigned char buf[BUFSIZ];
        int nfnd;

        if (cout == NULL) {
                warnx("Lost control connection for abort");
                if (ptabflg)
                        code = -1;
                lostpeer(0);
                return;
        }
        /*
         * send IAC in urgent mode instead of DM because 4.3BSD places oob mark
         * after urgent byte rather than before as is protocol now
         */
        buf[0] = IAC;
        buf[1] = IP;
        buf[2] = IAC;
        if (send(fileno(cout), buf, 3, MSG_OOB) != 3)
                warn("Can't send abort message");
        fprintf(cout, "%cABOR\r\n", DM);        /* TODO: handle EINTR? */
        (void)fflush(cout);
        if ((nfnd = empty(cin, din, 10)) <= 0) {
                if (nfnd < 0)
                        warn("Can't send abort message");
                if (ptabflg)
                        code = -1;
                lostpeer(0);
        }
        if (din && (nfnd & 2)) {
                while (read(fileno(din), buf, BUFSIZ) > 0)
                        continue;
        }
        if (getreply(0) == ERROR && code == 552) {
                /* 552 needed for nic style abort */
                (void)getreply(0);
        }
        (void)getreply(0);
}

/*
 * Ensure that ai->ai_addr is NOT an IPv4 mapped address.
 * IPv4 mapped address complicates too many things in FTP
 * protocol handling, as FTP protocol is defined differently
 * between IPv4 and IPv6.
 *
 * This may not be the best way to handle this situation,
 * since the semantics of IPv4 mapped address is defined in
 * the kernel.  There are configurations where we should use
 * IPv4 mapped address as native IPv6 address, not as
 * "an IPv6 address that embeds IPv4 address" (namely, SIIT).
 *
 * More complete solution would be to have an additional
 * getsockopt to grab "real" peername/sockname.  "real"
 * peername/sockname will be AF_INET if IPv4 mapped address
 * is used to embed IPv4 address, and will be AF_INET6 if
 * we use it as native.  What a mess!
 */
void
ai_unmapped(struct addrinfo *ai)
{
#ifdef INET6
        struct sockaddr_in6 *sin6;
        struct sockaddr_in sin;
        socklen_t len;

        if (ai->ai_family != AF_INET6)
                return;
        if (ai->ai_addrlen != sizeof(struct sockaddr_in6) ||
            sizeof(sin) > ai->ai_addrlen)
                return;
        sin6 = (struct sockaddr_in6 *)(void *)ai->ai_addr;
        if (!IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
                return;

        memset(&sin, 0, sizeof(sin));
        sin.sin_family = AF_INET;
        len = sizeof(struct sockaddr_in);
        memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12],
            sizeof(sin.sin_addr));
        sin.sin_port = sin6->sin6_port;

        ai->ai_family = AF_INET;
#if defined(HAVE_STRUCT_SOCKADDR_IN_SIN_LEN)
        sin.sin_len = len;
#endif
        memcpy(ai->ai_addr, &sin, len);
        ai->ai_addrlen = len;
#endif
}

#ifdef NO_USAGE
void
xusage(void)
{
        fputs("Usage error\n", ttyout);
}
#endif