root/libexec/ftpd/ftpd.c
/*      $OpenBSD: ftpd.c,v 1.235 2025/05/08 15:22:49 deraadt Exp $      */
/*      $NetBSD: ftpd.c,v 1.15 1995/06/03 22:46:47 mycroft Exp $        */

/*
 * 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.
 */

/*
 * Copyright (c) 1985, 1988, 1990, 1992, 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.
 */

/*
 * FTP server.
 */
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/mman.h>

#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>

#define FTP_NAMES
#include <arpa/ftp.h>
#include <arpa/inet.h>
#include <arpa/telnet.h>

#include <bsd_auth.h>
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <glob.h>
#include <limits.h>
#include <login_cap.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <vis.h>
#include <unistd.h>
#include <utmp.h>
#include <poll.h>

#include "pathnames.h"
#include "monitor.h"
#include "extern.h"

extern  off_t restart_point;
extern  char cbuf[];

union sockunion ctrl_addr;
union sockunion data_source;
union sockunion data_dest;
union sockunion his_addr;
union sockunion pasv_addr;

sigset_t allsigs;

int     daemon_mode = 0;
int     data;
int     logged_in;
struct  passwd *pw;
int     debug = 0;
int     timeout = 900;    /* timeout after 15 minutes of inactivity */
int     maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
int     logging;
int     anon_ok = 1;
int     anon_only = 0;
unsigned int minuid = 1000;
int     multihome = 0;
int     guest;
int     stats;
int     statfd = -1;
int     portcheck = 1;
int     dochroot;
int     type;
int     form;
int     stru;                   /* avoid C keyword */
int     mode;
int     doutmp = 0;             /* update utmp file */
int     nowtmp = 0;             /* do not update wtmp file */
int     usedefault = 1;         /* for data transfers */
int     pdata = -1;             /* for passive mode */
int     family = AF_UNSPEC;
volatile sig_atomic_t transflag;
off_t   file_size;
off_t   byte_count;
mode_t  defumask = S_IWGRP|S_IWOTH;             /* default umask value */
int     umaskchange = 1;                /* allow user to change umask value. */
char    tmpline[7];
char    hostname[HOST_NAME_MAX+1];
char    remotehost[HOST_NAME_MAX+1];
char    dhostname[HOST_NAME_MAX+1];
char    *guestpw;
char    ttyline[20];
static struct utmp utmp;        /* for utmp */
static  login_cap_t *lc;
static  auth_session_t *as;
static  volatile sig_atomic_t recvurg;

int epsvall = 0;

/*
 * Timeout intervals for retrying connections
 * to hosts that don't accept PORT cmds.  This
 * is a kludge, but given the problems with TCP...
 */
#define SWAITMAX        90      /* wait at most 90 seconds */
#define SWAITINT        5       /* interval between retries */

int     swaitmax = SWAITMAX;
int     swaitint = SWAITINT;

char    proctitle[BUFSIZ];      /* initial part of title */

#define LOGCMD(cmd, file) \
        if (logging > 1) \
            syslog(LOG_INFO,"%s %s%s", cmd, \
                *(file) == '/' ? "" : curdir(), file);
#define LOGCMD2(cmd, file1, file2) \
         if (logging > 1) \
            syslog(LOG_INFO,"%s %s%s %s%s", cmd, \
                *(file1) == '/' ? "" : curdir(), file1, \
                *(file2) == '/' ? "" : curdir(), file2);
#define LOGBYTES(cmd, file, cnt) \
        if (logging > 1) { \
                if ((cnt) == -1) \
                    syslog(LOG_INFO,"%s %s%s", cmd, \
                        *(file) == '/' ? "" : curdir(), file); \
                else \
                    syslog(LOG_INFO, "%s %s%s = %lld bytes", \
                        cmd, (*(file) == '/') ? "" : curdir(), file, \
                        (long long)(cnt)); \
        }

static void      ack(const char *);
static void      sigurg(int);
static void      myoob(void);
static int       checkuser(char *, const char *);
static FILE     *dataconn(const char *, off_t, char *);
static void      dolog(struct sockaddr *);
static char     *copy_dir(char *, struct passwd *);
static char     *curdir(void);
static void      end_login(void);
static FILE     *getdatasock(char *);
static int       guniquefd(const char *, char **);
static void      lostconn(int);
static void      sigquit(int);
static int       receive_data(FILE *, FILE *);
static void      replydirname(const char *, const char *);
static int       send_data(FILE *, FILE *, off_t, off_t, int);
static struct passwd *
                 sgetpwnam(const char *, struct passwd *);
static void      reapchild(int);
static void      usage(void);

void     logxfer(const char *, off_t, time_t);
void     set_slave_signals(void);

static char *
curdir(void)
{
        static char path[PATH_MAX+1];   /* path + '/' */

        if (getcwd(path, sizeof(path)-1) == NULL)
                return ("");
        if (path[1] != '\0')            /* special case for root dir. */
                strlcat(path, "/", sizeof path);
        /* For guest account, skip / since it's chrooted */
        return (guest ? path+1 : path);
}

char *argstr = "AdDhnlm:MSt:T:u:PUvW46";

static void
usage(void)
{
        syslog(LOG_ERR,
            "usage: ftpd [-46ADdlMnPSUW] [-m minuid] [-T maxtimeout] "
            "[-t timeout] [-u mask]");
        exit(2);
}

int
main(int argc, char *argv[])
{
        socklen_t addrlen;
        int ch, on = 1, tos;
        char line[LINE_MAX];
        FILE *fp;
        struct hostent *hp;
        struct sigaction sa;
        int error = 0;
        const char *errstr;

        tzset();                /* in case no timezone database in ~ftp */
        sigfillset(&allsigs);   /* used to block signals while root */
        sigemptyset(&sa.sa_mask);
        sa.sa_flags = SA_RESTART;

        while ((ch = getopt(argc, argv, argstr)) != -1) {
                switch (ch) {
                case 'A':
                        anon_only = 1;
                        break;

                case 'd':
                case 'v':               /* deprecated */
                        debug = 1;
                        break;

                case 'D':
                        daemon_mode = 1;
                        break;

                case 'P':
                        portcheck = 0;
                        break;

                case 'h':               /* deprecated */
                        break;

                case 'l':
                        logging++;      /* > 1 == extra logging */
                        break;

                case 'm':
                        minuid = strtonum(optarg, 0, UINT_MAX, &errstr);
                        if (errstr) {
                                syslog(LOG_ERR,
                                    "%s is a bad value for -m, aborting",
                                    optarg);
                                exit(2);
                        }
                        break;

                case 'M':
                        multihome = 1;
                        break;

                case 'n':
                        anon_ok = 0;
                        break;

                case 'S':
                        stats = 1;
                        break;

                case 't':
                        timeout = strtonum(optarg, 0, INT_MAX, &errstr);
                        if (errstr) {
                                syslog(LOG_ERR,
                                    "%s is a bad value for -t, aborting",
                                    optarg);
                                exit(2);
                        }
                        if (maxtimeout < timeout)
                                maxtimeout = timeout;
                        break;

                case 'T':
                        maxtimeout = strtonum(optarg, 0, INT_MAX,
                            &errstr);
                        if (errstr) {
                                syslog(LOG_ERR,
                                    "%s is a bad value for -T, aborting",
                                    optarg);
                                exit(2);
                        }
                        if (timeout > maxtimeout)
                                timeout = maxtimeout;
                        break;

                case 'u':
                    {
                        long val = 0;
                        char *p;
                        umaskchange = 0;

                        val = strtol(optarg, &p, 8);
                        if (*optarg == '\0' || *p != '\0' || val < 0 ||
                            (val & ~ACCESSPERMS)) {
                                syslog(LOG_ERR,
                                    "%s is a bad value for -u, aborting",
                                    optarg);
                                exit(2);
                        }
                        defumask = val;
                        break;
                    }

                case 'U':
                        doutmp = 1;
                        break;

                case 'W':
                        nowtmp = 1;
                        break;

                case '4':
                        family = AF_INET;
                        break;

                case '6':
                        family = AF_INET6;
                        break;

                default:
                        usage();
                        break;
                }
        }

        if (nowtmp && doutmp) {
                syslog(LOG_ERR, "options 'U' and 'W' are mutually exclusive");
                exit(1);
        }

        (void) freopen(_PATH_DEVNULL, "w", stderr);

        /*
         * LOG_NDELAY sets up the logging connection immediately,
         * necessary for anonymous ftp's that chroot and can't do it later.
         */
        openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);

        if (getpwnam(FTPD_PRIVSEP_USER) == NULL) {
                syslog(LOG_ERR, "privilege separation user %s not found",
                    FTPD_PRIVSEP_USER);
                exit(1);
        }

        if (daemon_mode) {
                int *fds, fd;
                struct pollfd *pfds;
                struct addrinfo hints, *res, *res0;
                nfds_t n, i;

                /*
                 * Detach from parent.
                 */
                if (daemon(1, 1) == -1) {
                        syslog(LOG_ERR, "failed to become a daemon");
                        exit(1);
                }
                sa.sa_handler = reapchild;
                (void) sigaction(SIGCHLD, &sa, NULL);

                memset(&hints, 0, sizeof(hints));
                hints.ai_family = family;
                hints.ai_socktype = SOCK_STREAM;
                hints.ai_protocol = IPPROTO_TCP;
                hints.ai_flags = AI_PASSIVE;
                error = getaddrinfo(NULL, "ftp", &hints, &res0);
                if (error) {
                        syslog(LOG_ERR, "%s", gai_strerror(error));
                        exit(1);
                }

                n = 0;
                for (res = res0; res; res = res->ai_next)
                        n++;

                fds = calloc(n, sizeof(int));
                pfds = calloc(n, sizeof(struct pollfd));
                if (!fds || !pfds) {
                        syslog(LOG_ERR, "%s", strerror(errno));
                        exit(1);
                }

                /*
                 * Open sockets, bind it to the FTP port, and start
                 * listening.
                 */
                n = 0;
                for (res = res0; res; res = res->ai_next) {
                        fds[n] = socket(res->ai_family, res->ai_socktype,
                            res->ai_protocol);
                        if (fds[n] == -1)
                                continue;

                        if (setsockopt(fds[n], SOL_SOCKET, SO_KEEPALIVE,
                            &on, sizeof(on)) == -1) {
                                close(fds[n]);
                                fds[n] = -1;
                                continue;
                        }

                        if (setsockopt(fds[n], SOL_SOCKET, SO_REUSEADDR,
                            &on, sizeof(on)) == -1) {
                                close(fds[n]);
                                fds[n] = -1;
                                continue;
                        }

                        if (bind(fds[n], res->ai_addr, res->ai_addrlen) == -1) {
                                close(fds[n]);
                                fds[n] = -1;
                                continue;
                        }
                        if (listen(fds[n], 32) == -1) {
                                close(fds[n]);
                                fds[n] = -1;
                                continue;
                        }

                        pfds[n].fd = fds[n];
                        pfds[n].events = POLLIN;
                        n++;
                }
                freeaddrinfo(res0);

                if (n == 0) {
                        syslog(LOG_ERR, "could not open control socket");
                        exit(1);
                }

                /*
                 * Loop forever accepting connection requests and forking off
                 * children to handle them.
                 */
                while (1) {
                        if (poll(pfds, n, INFTIM) == -1) {
                                if (errno == EINTR)
                                        continue;
                                syslog(LOG_ERR, "poll: %m");
                                exit(1);
                        }
                        for (i = 0; i < n; i++)
                                if (pfds[i].revents & POLLIN) {
                                        addrlen = sizeof(his_addr);
                                        fd = accept(pfds[i].fd,
                                            (struct sockaddr *)&his_addr,
                                            &addrlen);
                                        if (fd != -1) {
                                                if (fork() == 0)
                                                        goto child;
                                                close(fd);
                                        }
                                }
                }

        child:
                /* child */
                (void)dup2(fd, STDIN_FILENO);
                (void)dup2(fd, STDOUT_FILENO);
                for (i = 0; i < n; i++)
                        close(fds[i]);
        } else {
                addrlen = sizeof(his_addr);
                if (getpeername(0, (struct sockaddr *)&his_addr,
                    &addrlen) == -1) {
                        /* syslog(LOG_ERR, "getpeername (%s): %m", argv[0]); */
                        exit(1);
                }
        }

        /* set this here so klogin can use it... */
        (void)snprintf(ttyline, sizeof(ttyline), "ftp%ld", (long)getpid());

        set_slave_signals();

        addrlen = sizeof(ctrl_addr);
        if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) == -1) {
                syslog(LOG_ERR, "getsockname: %m");
                exit(1);
        }
        if (his_addr.su_family == AF_INET6 &&
            IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr)) {
                syslog(LOG_WARNING,
                    "Connection from IPv4 mapped address is not supported.");
                reply(530, "System not available.");
                exit(1);
        }
        tos = IPTOS_LOWDELAY;
        switch (his_addr.su_family) {
        case AF_INET:
                if (setsockopt(0, IPPROTO_IP, IP_TOS, &tos,
                    sizeof(int)) == -1)
                        syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
                break;
        case AF_INET6:
                if (setsockopt(0, IPPROTO_IPV6, IPV6_TCLASS, &tos,
                    sizeof(int)) == -1)
                        syslog(LOG_WARNING, "setsockopt (IPV6_TCLASS): %m");
                break;
        }
        data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);

        /* Try to handle urgent data inline */
        if (setsockopt(0, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) == -1)
                syslog(LOG_ERR, "setsockopt: %m");

        dolog((struct sockaddr *)&his_addr);

        /*
         * Set up default state
         */
        data = -1;
        type = TYPE_A;
        form = FORM_N;
        stru = STRU_F;
        mode = MODE_S;
        tmpline[0] = '\0';

        /* If logins are disabled, print out the message. */
        if ((fp = fopen(_PATH_NOLOGIN, "r")) != NULL) {
                while (fgets(line, sizeof(line), fp) != NULL) {
                        line[strcspn(line, "\n")] = '\0';
                        lreply(530, "%s", line);
                }
                (void) fclose(fp);
                reply(530, "System not available.");
                exit(0);
        }
        if ((fp = fopen(_PATH_FTPWELCOME, "r")) != NULL) {
                while (fgets(line, sizeof(line), fp) != NULL) {
                        line[strcspn(line, "\n")] = '\0';
                        lreply(220, "%s", line);
                }
                (void) fclose(fp);
                /* reply(220,) must follow */
        }
        (void) gethostname(hostname, sizeof(hostname));

        /* Make sure hostname is fully qualified. */
        hp = gethostbyname(hostname);
        if (hp != NULL)
                strlcpy(hostname, hp->h_name, sizeof(hostname));

        if (multihome) {
                error = getnameinfo((struct sockaddr *)&ctrl_addr,
                    ctrl_addr.su_len, dhostname, sizeof(dhostname), NULL, 0, 0);
        }

        if (error != 0)
                reply(220, "FTP server ready.");
        else
                reply(220, "%s FTP server ready.",
                    (multihome ? dhostname : hostname));

        monitor_init();

        for (;;)
                (void) yyparse();
        /* NOTREACHED */
}

/*
 * Signal handlers.
 */
static void
lostconn(int signo)
{
        struct syslog_data sdata = SYSLOG_DATA_INIT;

        sdata.log_fac = LOG_FTP;
        if (debug)
                syslog_r(LOG_DEBUG, &sdata, "lost connection");
        dologout(1);
}

static void
sigquit(int signo)
{
        struct syslog_data sdata = SYSLOG_DATA_INIT;

        sdata.log_fac = LOG_FTP;
        syslog_r(LOG_DEBUG, &sdata, "got signal %s", sys_signame[signo]);
        dologout(1);
}

/*
 * Save the result of a getpwnam.  Used for USER command, since
 * the data returned must not be clobbered by any other command
 * (e.g., globbing).
 */
static struct passwd *
sgetpwnam(const char *name, struct passwd *pw)
{
        static struct passwd *save;
        struct passwd *old;

        if (pw == NULL && (pw = getpwnam(name)) == NULL)
                return (NULL);
        old = save;
        save = pw_dup(pw);
        if (save == NULL) {
                perror_reply(421, "Local resource failure: malloc");
                dologout(1);
                /* NOTREACHED */
        }
        if (old) {
                explicit_bzero(old->pw_passwd, strlen(old->pw_passwd));
                free(old);
        }
        return (save);
}

static int login_attempts;      /* number of failed login attempts */
static int askpasswd;           /* had user command, ask for passwd */
static char curname[LOGIN_NAME_MAX];    /* current USER name */

/*
 * USER command.
 * Sets global passwd pointer pw if named account exists and is acceptable;
 * sets askpasswd if a PASS command is expected.  If logged in previously,
 * need to reset state.  If name is "ftp" or "anonymous", the name is not in
 * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
 * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
 * requesting login privileges.  Disallow anyone who does not have a standard
 * shell as returned by getusershell().  Disallow anyone mentioned in the file
 * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
 */
void
user(char *name)
{
        char *cp, *shell, *style, *host;
        char *class = NULL;

        if (logged_in) {
                kill_slave("user already logged in");
                end_login();
        }

        /* Close session from previous user if there was one. */
        if (as) {
                auth_close(as);
                as = NULL;
        }
        if (lc) {
                login_close(lc);
                lc = NULL;
        }

        if ((style = strchr(name, ':')) != NULL)
                *style++ = 0;

        guest = 0;
        askpasswd = 0;
        host = multihome ? dhostname : hostname;
        if (anon_ok &&
            (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0)) {
                if (checkuser(_PATH_FTPUSERS, "ftp") ||
                    checkuser(_PATH_FTPUSERS, "anonymous"))
                        reply(530, "User %s access denied.", name);
                else if ((pw = sgetpwnam("ftp", NULL)) != NULL) {
                        if ((lc = login_getclass(pw->pw_class)) == NULL ||
                            (as = auth_open()) == NULL ||
                            auth_setpwd(as, pw) != 0 ||
                            auth_setoption(as, "FTPD_HOST", host) < 0) {
                                if (as) {
                                        auth_close(as);
                                        as = NULL;
                                }
                                if (lc) {
                                        login_close(lc);
                                        lc = NULL;
                                }
                                reply(421, "Local resource failure");
                                return;
                        }
                        guest = 1;
                        askpasswd = 1;
                        reply(331,
                        "Guest login ok, send your email address as password.");
                } else
                        reply(530, "User %s unknown.", name);
                if (!askpasswd && logging)
                        syslog(LOG_NOTICE,
                            "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
                return;
        }

        shell = _PATH_BSHELL;
        if ((pw = sgetpwnam(name, NULL))) {
                class = pw->pw_class;
                if (pw->pw_shell != NULL && *pw->pw_shell != '\0')
                        shell = pw->pw_shell;
                while ((cp = getusershell()) != NULL)
                        if (strcmp(cp, shell) == 0)
                                break;
                shell = cp;
                endusershell();
        }

        /* Get login class; if invalid style treat like unknown user. */
        lc = login_getclass(class);
        if (lc && (style = login_getstyle(lc, style, "auth-ftp")) == NULL) {
                login_close(lc);
                lc = NULL;
                pw = NULL;
        }

        /* Do pre-authentication setup. */
        if (lc && ((as = auth_open()) == NULL ||
            (pw != NULL && auth_setpwd(as, pw) != 0) ||
            auth_setitem(as, AUTHV_STYLE, style) < 0 ||
            auth_setitem(as, AUTHV_NAME, name) < 0 ||
            auth_setitem(as, AUTHV_CLASS, class) < 0 ||
            auth_setoption(as, "login", "yes") < 0 ||
            auth_setoption(as, "notickets", "yes") < 0 ||
            auth_setoption(as, "FTPD_HOST", host) < 0)) {
                if (as) {
                        auth_close(as);
                        as = NULL;
                }
                login_close(lc);
                lc = NULL;
                reply(421, "Local resource failure");
                return;
        }
        if (logging)
                strlcpy(curname, name, sizeof(curname));

        dochroot = (lc && login_getcapbool(lc, "ftp-chroot", 0)) ||
            checkuser(_PATH_FTPCHROOT, name);
        if (anon_only && !dochroot) {
                reply(530, "User %s access denied.", name);
                return;
        }
        if (pw) {
                if (pw->pw_uid < minuid) {
                        reply(530, "User %s access denied.", name);
                        if (logging)
                                syslog(LOG_NOTICE,
                                    "FTP LOGIN REFUSED FROM %s, %s (UID))",
                                    remotehost, name);
                        return;
                }
                if ((!shell && !dochroot) || checkuser(_PATH_FTPUSERS, name)) {
                        reply(530, "User %s access denied.", name);
                        if (logging)
                                syslog(LOG_NOTICE,
                                    "FTP LOGIN REFUSED FROM %s, %s",
                                    remotehost, name);
                        pw = NULL;
                        return;
                }
        }

        if (as != NULL && (cp = auth_challenge(as)) != NULL)
                reply(331, "%s", cp);
        else
                reply(331, "Password required for %s.", name);

        askpasswd = 1;
        /*
         * Delay before reading passwd after first failed
         * attempt to slow down passwd-guessing programs.
         */
        if (login_attempts)
                sleep((unsigned) login_attempts);
}

/*
 * Check if a user is in the file "fname"
 */
static int
checkuser(char *fname, const char *name)
{
        FILE *fp;
        int found = 0;
        char *p, line[BUFSIZ];

        if ((fp = fopen(fname, "r")) != NULL) {
                while (fgets(line, sizeof(line), fp) != NULL)
                        if ((p = strchr(line, '\n')) != NULL) {
                                *p = '\0';
                                if (line[0] == '#')
                                        continue;
                                if (strcmp(line, name) == 0) {
                                        found = 1;
                                        break;
                                }
                        }
                (void) fclose(fp);
        }
        return (found);
}

/*
 * Terminate login as previous user, if any, resetting state;
 * used when USER command is given or login fails.
 */
static void
end_login(void)
{
        sigprocmask (SIG_BLOCK, &allsigs, NULL);
        if (logged_in) {
                if (!nowtmp)
                        ftpdlogwtmp(ttyline, "", "");
                if (doutmp)
                        ftpd_logout(utmp.ut_line);
        }
        reply(530, "Please reconnect to work as another user");
        _exit(0);
}

enum auth_ret
pass(char *passwd)
{
        int authok;
        unsigned int flags;
        FILE *fp;
        static char homedir[PATH_MAX];
        char *motd, *dir, rootdir[PATH_MAX];
        size_t sz_pw_dir;

        if (logged_in || askpasswd == 0) {
                reply(503, "Login with USER first.");
                return (AUTH_FAILED);
        }
        askpasswd = 0;
        if (!guest) {           /* "ftp" is only account allowed no password */
                authok = 0;
                if (pw == NULL || pw->pw_passwd[0] == '\0') {
                        useconds_t us;

                        /* Sleep between 1 and 3 seconds to emulate a crypt. */
                        us = arc4random_uniform(3000000);
                        usleep(us);
                        if (as != NULL) {
                                auth_close(as);
                                as = NULL;
                        }
                } else {
                        authok = auth_userresponse(as, passwd, 0);
                        as = NULL;
                }
                if (authok == 0) {
                        reply(530, "Login incorrect.");
                        if (logging)
                                syslog(LOG_NOTICE,
                                    "FTP LOGIN FAILED FROM %s, %s",
                                    remotehost, curname);
                        pw = NULL;
                        if (login_attempts++ >= 5) {
                                syslog(LOG_NOTICE,
                                    "repeated login failures from %s",
                                    remotehost);
                                kill_slave("repeated login failures");
                                _exit(0);
                        }
                        return (AUTH_FAILED);
                }
        } else if (lc != NULL) {
                /* Save anonymous' password. */
                free(guestpw);
                guestpw = strdup(passwd);
                if (guestpw == NULL) {
                        kill_slave("out of mem");
                        fatal("Out of memory.");
                }

                authok = auth_approval(as, lc, pw->pw_name, "ftp");
                auth_close(as);
                as = NULL;
                if (authok == 0) {
                        syslog(LOG_INFO|LOG_AUTH,
                            "FTP LOGIN FAILED (HOST) as %s: approval failure.",
                            pw->pw_name);
                        reply(530, "Approval failure.");
                        kill_slave("approval failure");
                        _exit(0);
                }
        } else {
                syslog(LOG_INFO|LOG_AUTH,
                    "FTP LOGIN CLASS %s MISSING for %s: approval failure.",
                    pw->pw_class, pw->pw_name);
                reply(530, "Permission denied.");
                kill_slave("permission denied");
                _exit(0);
        }

        if (monitor_post_auth() == 1) {
                /* Post-auth monitor process */
                logged_in = 1;
                return (AUTH_MONITOR);
        }

        login_attempts = 0;             /* this time successful */
        /* set umask via setusercontext() unless -u flag was given. */
        flags = LOGIN_SETGROUP|LOGIN_SETPRIORITY|LOGIN_SETRESOURCES;
        if (umaskchange)
                flags |= LOGIN_SETUMASK;
        else
                (void) umask(defumask);
        if (setusercontext(lc, pw, 0, flags) != 0) {
                perror_reply(421, "Local resource failure: setusercontext");
                syslog(LOG_NOTICE, "setusercontext: %m");
                dologout(1);
                /* NOTREACHED */
        }

        /* open wtmp before chroot */
        if (!nowtmp)
                ftpdlogwtmp(ttyline, pw->pw_name, remotehost);

        /* open utmp before chroot */
        if (doutmp) {
                memset(&utmp, 0, sizeof(utmp));
                (void)time(&utmp.ut_time);
                (void)strncpy(utmp.ut_name, pw->pw_name, sizeof(utmp.ut_name));
                (void)strncpy(utmp.ut_host, remotehost, sizeof(utmp.ut_host));
                (void)strncpy(utmp.ut_line, ttyline, sizeof(utmp.ut_line));
                ftpd_login(&utmp);
        }

        /* open stats file before chroot */
        if (guest && (stats == 1) && (statfd < 0))
                if ((statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND)) == -1)
                        stats = 0;

        logged_in = 1;

        if ((dir = login_getcapstr(lc, "ftp-dir", NULL, NULL))) {
                char *newdir;

                newdir = copy_dir(dir, pw);
                if (newdir == NULL) {
                        perror_reply(421, "Local resource failure: malloc");
                        dologout(1);
                        /* NOTREACHED */
                }
                pw->pw_dir = newdir;
                pw = sgetpwnam(NULL, pw);
                free(dir);
                free(newdir);
        }

        /* make sure pw->pw_dir is big enough to hold "/" */
        sz_pw_dir = strlen(pw->pw_dir) + 1;
        if (sz_pw_dir < 2) {
                pw->pw_dir = "/";
                pw = sgetpwnam(NULL, pw);
                sz_pw_dir = 2;
        }

        if (guest || dochroot) {
                if (multihome && guest) {
                        struct stat ts;

                        /* Compute root directory. */
                        snprintf(rootdir, sizeof(rootdir), "%s/%s",
                            pw->pw_dir, dhostname);
                        if (stat(rootdir, &ts) == -1) {
                                snprintf(rootdir, sizeof(rootdir), "%s/%s",
                                    pw->pw_dir, hostname);
                        }
                } else
                        strlcpy(rootdir, pw->pw_dir, sizeof(rootdir));
        }
        if (guest) {
                /*
                 * We MUST do a chdir() after the chroot. Otherwise
                 * the old current directory will be accessible as "."
                 * outside the new root!
                 */
                if (chroot(rootdir) == -1 || chdir("/") == -1) {
                        reply(550, "Can't set guest privileges.");
                        goto bad;
                }
                strlcpy(pw->pw_dir, "/", sz_pw_dir);
                if (setenv("HOME", "/", 1) == -1) {
                        reply(550, "Can't setup environment.");
                        goto bad;
                }
        } else if (dochroot) {
                if (chroot(rootdir) == -1 || chdir("/") == -1) {
                        reply(550, "Can't change root.");
                        goto bad;
                }
                strlcpy(pw->pw_dir, "/", sz_pw_dir);
                if (setenv("HOME", "/", 1) == -1) {
                        reply(550, "Can't setup environment.");
                        goto bad;
                }
        } else if (chdir(pw->pw_dir) == -1) {
                if (chdir("/") == -1) {
                        reply(530, "User %s: can't change directory to %s.",
                            pw->pw_name, pw->pw_dir);
                        goto bad;
                } else
                        lreply(230, "No directory! Logging in with home=/");
        }
        if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) {
                reply(550, "Can't set gid.");
                goto bad;
        }
        if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) {
                reply(550, "Can't set uid.");
                goto bad;
        }
        sigprocmask(SIG_UNBLOCK, &allsigs, NULL);

        /*
         * Set home directory so that use of ~ (tilde) works correctly.
         */
        if (getcwd(homedir, PATH_MAX) != NULL) {
                if (setenv("HOME", homedir, 1) == -1) {
                        reply(550, "Can't setup environment.");
                        goto bad;
                }
        }

        /*
         * Display a login message, if it exists.
         * N.B. reply(230,) must follow the message.
         */
        motd = login_getcapstr(lc, "welcome", NULL, NULL);
        if ((fp = fopen(motd ? motd : _PATH_FTPLOGINMESG, "r")) != NULL) {
                char line[LINE_MAX];

                while (fgets(line, sizeof(line), fp) != NULL) {
                        line[strcspn(line, "\n")] = '\0';
                        lreply(230, "%s", line);
                }
                (void) fclose(fp);
        }
        free(motd);
        if (guest) {
                reply(230, "Guest login ok, access restrictions apply.");
                snprintf(proctitle, sizeof(proctitle),
                    "%s: anonymous/%.*s", remotehost,
                    (int)(sizeof(proctitle) - sizeof(remotehost) -
                    sizeof(": anonymous/")), passwd);
                setproctitle("%s", proctitle);
                if (logging)
                        syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
                            remotehost, passwd);
        } else {
                reply(230, "User %s logged in.", pw->pw_name);
                snprintf(proctitle, sizeof(proctitle),
                    "%s: %s", remotehost, pw->pw_name);
                setproctitle("%s", proctitle);
                if (logging)
                        syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
                            remotehost, pw->pw_name);
        }
        login_close(lc);
        lc = NULL;
        return (AUTH_SLAVE);
bad:
        /* Forget all about it... */
        login_close(lc);
        lc = NULL;
        end_login();
        return (AUTH_FAILED);
}

void
retrieve(enum ret_cmd cmd, const char *name)
{
        FILE *fin, *dout;
        struct stat st;
        pid_t pid;
        time_t start;

        if (cmd == RET_FILE) {
                fin = fopen(name, "r");
                st.st_size = 0;
        } else {
                fin = ftpd_ls(name, &pid);
                st.st_size = -1;
                st.st_blksize = BUFSIZ;
        }
        if (fin == NULL) {
                if (errno != 0) {
                        perror_reply(550, name);
                        if (cmd == RET_FILE) {
                                LOGCMD("get", name);
                        }
                }
                return;
        }
        byte_count = -1;
        if (cmd == RET_FILE &&
            (fstat(fileno(fin), &st) == -1 || !S_ISREG(st.st_mode))) {
                reply(550, "%s: not a plain file.", name);
                goto done;
        }
        if (restart_point) {
                if (type == TYPE_A) {
                        off_t i, n;
                        int c;

                        n = restart_point;
                        i = 0;
                        while (i++ < n) {
                                if ((c = getc(fin)) == EOF) {
                                        if (ferror(fin)) {
                                                perror_reply(550, name);
                                                goto done;
                                        } else
                                                break;
                                }
                                if (c == '\n')
                                        i++;
                        }
                } else if (lseek(fileno(fin), restart_point, SEEK_SET) == -1) {
                        perror_reply(550, name);
                        goto done;
                }
        }
        dout = dataconn(name, st.st_size, "w");
        if (dout == NULL)
                goto done;
        time(&start);
        send_data(fin, dout, st.st_blksize, st.st_size,
            (restart_point == 0 && cmd == RET_FILE && S_ISREG(st.st_mode)));
        if ((cmd == RET_FILE) && stats)
                logxfer(name, byte_count, start);
        (void) fclose(dout);
        data = -1;
done:
        if (pdata >= 0)
                (void) close(pdata);
        pdata = -1;
        if (cmd == RET_FILE) {
                LOGBYTES("get", name, byte_count);
                fclose(fin);
        } else {
                ftpd_pclose(fin, pid);
        }
}

void
store(const char *name, const char *mode, int unique)
{
        FILE *fout, *din;
        int (*closefunc)(FILE *);
        struct stat st;
        int fd;

        if (restart_point && *mode != 'a')
                mode = "r+";

        if (unique && stat(name, &st) == 0) {
                char *nam;

                fd = guniquefd(name, &nam);
                if (fd == -1) {
                        LOGCMD(*mode == 'w' ? "put" : "append", name);
                        return;
                }
                name = nam;
                fout = fdopen(fd, mode);
        } else
                fout = fopen(name, mode);

        closefunc = fclose;
        if (fout == NULL) {
                perror_reply(553, name);
                LOGCMD(*mode == 'w' ? "put" : "append", name);
                return;
        }
        byte_count = -1;
        if (restart_point) {
                if (type == TYPE_A) {
                        off_t i, n;
                        int c;

                        n = restart_point;
                        i = 0;
                        while (i++ < n) {
                                if ((c = getc(fout)) == EOF) {
                                        if (ferror(fout)) {
                                                perror_reply(550, name);
                                                goto done;
                                        } else
                                                break;
                                }
                                if (c == '\n')
                                        i++;
                        }
                        /*
                         * We must do this seek to "current" position
                         * because we are changing from reading to
                         * writing.
                         */
                        if (fseek(fout, 0, SEEK_CUR) == -1) {
                                perror_reply(550, name);
                                goto done;
                        }
                } else if (lseek(fileno(fout), restart_point, SEEK_SET) == -1) {
                        perror_reply(550, name);
                        goto done;
                }
        }
        din = dataconn(name, -1, "r");
        if (din == NULL)
                goto done;
        if (receive_data(din, fout) == 0) {
                if (unique)
                        reply(226, "Transfer complete (unique file name:%s).",
                            name);
                else
                        reply(226, "Transfer complete.");
        }
        (void) fclose(din);
        data = -1;
        pdata = -1;
done:
        LOGBYTES(*mode == 'w' ? "put" : "append", name, byte_count);
        (*closefunc)(fout);
}

static FILE *
getdatasock(char *mode)
{
        int opt, s, t, tries;

        if (data >= 0)
                return (fdopen(data, mode));
        sigprocmask (SIG_BLOCK, &allsigs, NULL);
        s = monitor_socket(ctrl_addr.su_family);
        if (s < 0)
                goto bad;
        opt = 1;
        if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR,
            &opt, sizeof(opt)) == -1)
                goto bad;
        /* anchor socket to avoid multi-homing problems */
        data_source = ctrl_addr;
        data_source.su_port = htons(20); /* ftp-data port */
        for (tries = 1; ; tries++) {
                if (monitor_bind(s, (struct sockaddr *)&data_source,
                    data_source.su_len) >= 0)
                        break;
                if (errno != EADDRINUSE || tries > 10)
                        goto bad;
                sleep((unsigned int)tries);
        }
        sigprocmask (SIG_UNBLOCK, &allsigs, NULL);

        opt = IPTOS_THROUGHPUT;
        switch (ctrl_addr.su_family) {
        case AF_INET:
                if (setsockopt(s, IPPROTO_IP, IP_TOS, &opt,
                    sizeof(opt)) == -1)
                        syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
                break;
        case AF_INET6:
                if (setsockopt(s, IPPROTO_IPV6, IPV6_TCLASS, &opt,
                    sizeof(opt)) == -1)
                        syslog(LOG_WARNING, "setsockopt (IPV6_TCLASS): %m");
                break;
        }
        /*
         * Turn off push flag to keep sender TCP from sending short packets
         * at the boundaries of each write().  Should probably do a SO_SNDBUF
         * to set the send buffer size as well, but that may not be desirable
         * in heavy-load situations.
         */
        opt = 1;
        if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &opt, sizeof(opt)) == -1)
                syslog(LOG_WARNING, "setsockopt (TCP_NOPUSH): %m");
        opt = 65536;
        if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt)) == -1)
                syslog(LOG_WARNING, "setsockopt (SO_SNDBUF): %m");

        return (fdopen(s, mode));
bad:
        /* Return the real value of errno (close may change it) */
        t = errno;
        sigprocmask (SIG_UNBLOCK, &allsigs, NULL);
        if (s >= 0)
                (void) close(s);
        errno = t;
        return (NULL);
}

static FILE *
dataconn(const char *name, off_t size, char *mode)
{
        char sizebuf[32];
        FILE *file = NULL;
        int retry = 0;
        in_port_t *p;
        u_char *fa, *ha;
        size_t alen;
        int error;

        file_size = size;
        byte_count = 0;
        if (size != -1) {
                (void) snprintf(sizebuf, sizeof(sizebuf), " (%lld bytes)",
                    (long long)size);
        } else
                sizebuf[0] = '\0';
        if (pdata >= 0) {
                union sockunion from;
                int s;
                socklen_t fromlen = sizeof(from);

                (void) alarm ((unsigned) timeout);
                s = accept(pdata, (struct sockaddr *)&from, &fromlen);
                (void) alarm (0);
                if (s == -1) {
                        reply(425, "Can't open data connection.");
                        (void) close(pdata);
                        pdata = -1;
                        return (NULL);
                }
                switch (from.su_family) {
                case AF_INET:
                        p = (in_port_t *)&from.su_sin.sin_port;
                        fa = (u_char *)&from.su_sin.sin_addr;
                        ha = (u_char *)&his_addr.su_sin.sin_addr;
                        alen = sizeof(struct in_addr);
                        break;
                case AF_INET6:
                        p = (in_port_t *)&from.su_sin6.sin6_port;
                        fa = (u_char *)&from.su_sin6.sin6_addr;
                        ha = (u_char *)&his_addr.su_sin6.sin6_addr;
                        alen = sizeof(struct in6_addr);
                        break;
                default:
                        reply(425, "Can't build data connection: "
                            "unknown address family");
                        (void) close(pdata);
                        (void) close(s);
                        pdata = -1;
                        return (NULL);
                }
                if (from.su_family != his_addr.su_family ||
                    ntohs(*p) < IPPORT_RESERVED) {
                        reply(425, "Can't build data connection: "
                            "address family or port error");
                        (void) close(pdata);
                        (void) close(s);
                        pdata = -1;
                        return (NULL);
                }
                if (portcheck && memcmp(fa, ha, alen) != 0) {
                        reply(425, "Can't build data connection: "
                            "illegal port number");
                        (void) close(pdata);
                        (void) close(s);
                        pdata = -1;
                        return (NULL);
                }
                (void) close(pdata);
                pdata = s;
                reply(150, "Opening %s mode data connection for '%s'%s.",
                    type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
                return (fdopen(pdata, mode));
        }
        if (data >= 0) {
                reply(125, "Using existing data connection for '%s'%s.",
                    name, sizebuf);
                usedefault = 1;
                return (fdopen(data, mode));
        }
        if (usedefault)
                data_dest = his_addr;
        usedefault = 1;
        do {
                if (file != NULL)
                        (void) fclose(file);
                file = getdatasock(mode);
                if (file == NULL) {
                        char hbuf[HOST_NAME_MAX+1], pbuf[10];

                        error = getnameinfo((struct sockaddr *)&data_source,
                            data_source.su_len, hbuf, sizeof(hbuf), pbuf,
                            sizeof(pbuf), NI_NUMERICHOST | NI_NUMERICSERV);
                        if (error != 0)
                                reply(425, "Can't create data socket: %s.",
                                    strerror(errno));
                        else
                                reply(425,
                                    "Can't create data socket (%s,%s): %s.",
                                    hbuf, pbuf, strerror(errno));
                        return (NULL);
                }

                /*
                 * attempt to connect to reserved port on client machine;
                 * this looks like an attack
                 */
                switch (data_dest.su_family) {
                case AF_INET:
                        p = (in_port_t *)&data_dest.su_sin.sin_port;
                        fa = (u_char *)&data_dest.su_sin.sin_addr;
                        ha = (u_char *)&his_addr.su_sin.sin_addr;
                        alen = sizeof(struct in_addr);
                        break;
                case AF_INET6:
                        p = (in_port_t *)&data_dest.su_sin6.sin6_port;
                        fa = (u_char *)&data_dest.su_sin6.sin6_addr;
                        ha = (u_char *)&his_addr.su_sin6.sin6_addr;
                        alen = sizeof(struct in6_addr);
                        break;
                default:
                        reply(425, "Can't build data connection: "
                            "unknown address family");
                        (void) fclose(file);
                        pdata = -1;
                        return (NULL);
                }
                if (data_dest.su_family != his_addr.su_family ||
                    ntohs(*p) < IPPORT_RESERVED || ntohs(*p) == 2049) { /* XXX */
                        reply(425, "Can't build data connection: "
                            "address family or port error");
                        (void) fclose(file);
                        return NULL;
                }
                if (portcheck && memcmp(fa, ha, alen) != 0) {
                        reply(435, "Can't build data connection: "
                            "illegal port number");
                        (void) fclose(file);
                        return NULL;
                }

                if (connect(fileno(file), (struct sockaddr *)&data_dest,
                    data_dest.su_len) == 0) {
                        reply(150, "Opening %s mode data connection for '%s'%s.",
                            type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
                        data = fileno(file);
                        return (file);
                }
                if (errno != EADDRINUSE)
                        break;
                sleep((unsigned) swaitint);
                retry += swaitint;
        } while (retry <= swaitmax);
        perror_reply(425, "Can't build data connection");
        (void) fclose(file);
        return (NULL);
}

/*
 * Transfer the contents of "instr" to "outstr" peer using the appropriate
 * encapsulation of the data subject to Mode, Structure, and Type.
 *
 * NB: Form isn't handled.
 */
static int
send_data(FILE *instr, FILE *outstr, off_t blksize, off_t filesize, int isreg)
{
        int c, cnt, filefd, netfd;
        char *buf, *bp;
        size_t len;

        transflag++;
        switch (type) {

        case TYPE_A:
                while ((c = getc(instr)) != EOF) {
                        if (recvurg)
                                goto got_oob;
                        byte_count++;
                        if (c == '\n') {
                                if (ferror(outstr))
                                        goto data_err;
                                (void) putc('\r', outstr);
                        }
                        (void) putc(c, outstr);
                }
                fflush(outstr);
                transflag = 0;
                if (ferror(instr))
                        goto file_err;
                if (ferror(outstr))
                        goto data_err;
                reply(226, "Transfer complete.");
                return(0);

        case TYPE_I:
        case TYPE_L:
                /*
                 * isreg is only set if we are not doing restart and we
                 * are sending a regular file
                 */
                netfd = fileno(outstr);
                filefd = fileno(instr);

                if (isreg && filesize < 16 * 1024 * 1024) {
                        size_t fsize = (size_t)filesize;

                        if (fsize == 0) {
                                transflag = 0;
                                reply(226, "Transfer complete.");
                                return(0);
                        }

                        buf = mmap(0, fsize, PROT_READ, MAP_SHARED, filefd, 0);
                        if (buf == MAP_FAILED) {
                                syslog(LOG_WARNING, "mmap(%llu): %m",
                                    (unsigned long long)fsize);
                                goto oldway;
                        }
                        bp = buf;
                        len = fsize;
                        do {
                                cnt = write(netfd, bp, len);
                                if (recvurg) {
                                        munmap(buf, fsize);
                                        goto got_oob;
                                }
                                len -= cnt;
                                bp += cnt;
                                if (cnt > 0)
                                        byte_count += cnt;
                        } while(cnt > 0 && len > 0);

                        transflag = 0;
                        munmap(buf, fsize);
                        if (cnt < 0)
                                goto data_err;
                        reply(226, "Transfer complete.");
                        return(0);
                }

oldway:
                if ((buf = malloc((size_t)blksize)) == NULL) {
                        transflag = 0;
                        perror_reply(451, "Local resource failure: malloc");
                        return(-1);
                }

                while ((cnt = read(filefd, buf, (size_t)blksize)) > 0 &&
                    write(netfd, buf, cnt) == cnt)
                        byte_count += cnt;
                transflag = 0;
                (void)free(buf);
                if (cnt != 0) {
                        if (cnt == -1)
                                goto file_err;
                        goto data_err;
                }
                reply(226, "Transfer complete.");
                return(0);
        default:
                transflag = 0;
                reply(550, "Unimplemented TYPE %d in send_data", type);
                return(-1);
        }

data_err:
        transflag = 0;
        reply(426, "Data connection");
        return(-1);

file_err:
        transflag = 0;
        reply(551, "Error on input file");
        return(-1);

got_oob:
        myoob();
        recvurg = 0;
        transflag = 0;
        return(-1);
}

/*
 * Transfer data from peer to "outstr" using the appropriate encapulation of
 * the data subject to Mode, Structure, and Type.
 *
 * N.B.: Form isn't handled.
 */
static int
receive_data(FILE *instr, FILE *outstr)
{
        int c;
        int cnt;
        char buf[BUFSIZ];
        struct sigaction sa, sa_saved;
        volatile int bare_lfs = 0;

        transflag++;
        switch (type) {

        case TYPE_I:
        case TYPE_L:
                memset(&sa, 0, sizeof(sa));
                sigfillset(&sa.sa_mask);
                sa.sa_flags = SA_RESTART;
                sa.sa_handler = lostconn;
                (void) sigaction(SIGALRM, &sa, &sa_saved);
                do {
                        (void) alarm ((unsigned) timeout);
                        cnt = read(fileno(instr), buf, sizeof(buf));
                        (void) alarm (0);
                        if (recvurg)
                                goto got_oob;

                        if (cnt > 0) {
                                if (write(fileno(outstr), buf, cnt) != cnt)
                                        goto file_err;
                                byte_count += cnt;
                        }
                } while (cnt > 0);
                (void) sigaction(SIGALRM, &sa_saved, NULL);
                if (cnt == -1)
                        goto data_err;
                transflag = 0;
                return (0);

        case TYPE_E:
                reply(553, "TYPE E not implemented.");
                transflag = 0;
                return (-1);

        case TYPE_A:
                while ((c = getc(instr)) != EOF) {
                        if (recvurg)
                                goto got_oob;
                        byte_count++;
                        if (c == '\n')
                                bare_lfs++;
                        while (c == '\r') {
                                if (ferror(outstr))
                                        goto data_err;
                                if ((c = getc(instr)) != '\n') {
                                        (void) putc ('\r', outstr);
                                        if (c == '\0' || c == EOF)
                                                goto contin2;
                                }
                        }
                        (void) putc(c, outstr);
        contin2:        ;
                }
                fflush(outstr);
                if (ferror(instr))
                        goto data_err;
                if (ferror(outstr))
                        goto file_err;
                transflag = 0;
                if (bare_lfs) {
                        lreply(226,
                            "WARNING! %d bare linefeeds received in ASCII mode",
                            bare_lfs);
                        printf("   File may not have transferred correctly.\r\n");
                }
                return (0);
        default:
                reply(550, "Unimplemented TYPE %d in receive_data", type);
                transflag = 0;
                return (-1);
        }

data_err:
        transflag = 0;
        reply(426, "Data Connection");
        return (-1);

file_err:
        transflag = 0;
        reply(452, "Error writing file");
        return (-1);

got_oob:
        myoob();
        recvurg = 0;
        transflag = 0;
        return (-1);
}

void
statfilecmd(const char *filename)
{
        FILE *fin;
        int c;
        int atstart;
        pid_t pid;
        fin = ftpd_ls(filename, &pid);
        if (fin == NULL) {
                reply(451, "Local resource failure");
                return;
        }
        lreply(211, "status of %s:", filename);
        atstart = 1;
        while ((c = getc(fin)) != EOF) {
                if (c == '\n') {
                        if (ferror(stdout)){
                                perror_reply(421, "control connection");
                                (void) ftpd_pclose(fin, pid);
                                dologout(1);
                                /* NOTREACHED */
                        }
                        if (ferror(fin)) {
                                perror_reply(551, filename);
                                (void) ftpd_pclose(fin, pid);
                                return;
                        }
                        (void) putc('\r', stdout);
                }
                if (atstart && isdigit(c))
                        (void) putc(' ', stdout);
                (void) putc(c, stdout);
                atstart = (c == '\n');
        }
        (void) ftpd_pclose(fin, pid);
        reply(211, "End of Status");
}

void
statcmd(void)
{
        union sockunion *su;
        u_char *a, *p;
        char hbuf[HOST_NAME_MAX+1];
        int ispassive;
        int error;

        lreply(211, "%s FTP server status:", hostname);
        error = getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
            hbuf, sizeof(hbuf), NULL, 0, NI_NUMERICHOST);
        printf("     Connected to %s", remotehost);
        if (error == 0 && strcmp(remotehost, hbuf) != 0)
                printf(" (%s)", hbuf);
        printf("\r\n");
        if (logged_in) {
                if (guest)
                        printf("     Logged in anonymously\r\n");
                else
                        printf("     Logged in as %s\r\n", pw->pw_name);
        } else if (askpasswd)
                printf("     Waiting for password\r\n");
        else
                printf("     Waiting for user name\r\n");
        printf("     TYPE: %s", typenames[type]);
        if (type == TYPE_A || type == TYPE_E)
                printf(", FORM: %s", formnames[form]);
        if (type == TYPE_L)
                printf(" 8");
        printf("; STRUcture: %s; transfer MODE: %s\r\n",
            strunames[stru], modenames[mode]);
        ispassive = 0;
        if (data != -1)
                printf("     Data connection open\r\n");
        else if (pdata != -1) {
                printf("     in Passive mode\r\n");
                su = (union sockunion *)&pasv_addr;
                ispassive++;
                goto printaddr;
        } else if (usedefault == 0) {
                size_t alen, i;
                int af;

                su = (union sockunion *)&data_dest;
printaddr:
                /* PASV/PORT */
                if (su->su_family == AF_INET) {
                        if (ispassive)
                                printf("211- PASV ");
                        else
                                printf("211- PORT ");
                        a = (u_char *)&su->su_sin.sin_addr;
                        p = (u_char *)&su->su_sin.sin_port;
                        printf("(%u,%u,%u,%u,%u,%u)\r\n",
                            a[0], a[1], a[2], a[3],
                            p[0], p[1]);
                }

                /* LPSV/LPRT */
                alen = 0;
                switch (su->su_family) {
                case AF_INET:
                        a = (u_char *)&su->su_sin.sin_addr;
                        p = (u_char *)&su->su_sin.sin_port;
                        alen = sizeof(su->su_sin.sin_addr);
                        af = 4;
                        break;
                case AF_INET6:
                        a = (u_char *)&su->su_sin6.sin6_addr;
                        p = (u_char *)&su->su_sin6.sin6_port;
                        alen = sizeof(su->su_sin6.sin6_addr);
                        af = 6;
                        break;
                default:
                        af = 0;
                        break;
                }
                if (af) {
                        if (ispassive)
                                printf("211- LPSV ");
                        else
                                printf("211- LPRT ");
                        printf("(%u,%llu", af, (unsigned long long)alen);
                        for (i = 0; i < alen; i++)
                                printf(",%u", a[i]);
                        printf(",%u,%u,%u)\r\n", 2, p[0], p[1]);
                }

                /* EPRT/EPSV */
                switch (su->su_family) {
                case AF_INET:
                        af = 1;
                        break;
                case AF_INET6:
                        af = 2;
                        break;
                default:
                        af = 0;
                        break;
                }
                if (af) {
                        char pbuf[10];
                        union sockunion tmp = *su;

                        if (tmp.su_family == AF_INET6)
                                tmp.su_sin6.sin6_scope_id = 0;
                        if (getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
                            hbuf, sizeof(hbuf), pbuf, sizeof(pbuf),
                            NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
                                if (ispassive)
                                        printf("211- EPSV ");
                                else
                                        printf("211- EPRT ");
                                printf("(|%u|%s|%s|)\r\n",
                                    af, hbuf, pbuf);
                        }
                }
        } else
                printf("     No data connection\r\n");
        reply(211, "End of status");
}

void
fatal(const char *s)
{

        reply(451, "Error in server: %s", s);
        reply(221, "Closing connection due to server error.");
        dologout(0);
        /* NOTREACHED */
}

void
reply(int n, const char *fmt, ...)
{
        char *buf, *p, *next;
        int rval;
        va_list ap;

        va_start(ap, fmt);
        rval = vasprintf(&buf, fmt, ap);
        va_end(ap);
        if (rval == -1 || buf == NULL) {
                printf("421 Local resource failure: malloc\r\n");
                fflush(stdout);
                dologout(1);
        }
        next = buf;
        while ((p = strsep(&next, "\n\r"))) {
                printf("%d%s %s\r\n", n, (next != NULL) ? "-" : "", p);
                if (debug)
                        syslog(LOG_DEBUG, "<--- %d%s %s", n,
                            (next != NULL) ? "-" : "", p);
        }
        (void)fflush(stdout);
        free(buf);
}


void
reply_r(int n, const char *fmt, ...)
{
        char *p, *next;
        char msg[BUFSIZ];
        char buf[BUFSIZ];
        va_list ap;
        struct syslog_data sdata = SYSLOG_DATA_INIT;

        sdata.log_fac = LOG_FTP;
        va_start(ap, fmt);
        vsnprintf(msg, sizeof(msg), fmt, ap);
        va_end(ap);

        next = msg;

        while ((p = strsep(&next, "\n\r"))) {
                snprintf(buf, sizeof(buf), "%d%s %s\r\n", n,
                    (next != NULL) ? "-" : "", p);
                write(STDOUT_FILENO, buf, strlen(buf));
                if (debug) {
                        buf[strlen(buf) - 2] = '\0';
                        syslog_r(LOG_DEBUG, &sdata, "<--- %s", buf);
                }
        }
}

void
lreply(int n, const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        (void)printf("%d- ", n);
        (void)vprintf(fmt, ap);
        va_end(ap);
        (void)printf("\r\n");
        (void)fflush(stdout);
        if (debug) {
                va_start(ap, fmt);
                syslog(LOG_DEBUG, "<--- %d- ", n);
                vsyslog(LOG_DEBUG, fmt, ap);
                va_end(ap);
        }
}

static void
ack(const char *s)
{

        reply(250, "%s command successful.", s);
}

void
nack(const char *s)
{

        reply(502, "%s command not implemented.", s);
}

void
yyerror(char *s)
{
        cbuf[strcspn(cbuf, "\n")] = '\0';
        reply(500, "'%s': command not understood.", cbuf);
}

void
delete(const char *name)
{
        struct stat st;

        LOGCMD("delete", name);
        if (stat(name, &st) == -1) {
                perror_reply(550, name);
                return;
        }
        if ((st.st_mode&S_IFMT) == S_IFDIR) {
                if (rmdir(name) == -1) {
                        perror_reply(550, name);
                        return;
                }
                goto done;
        }
        if (unlink(name) == -1) {
                perror_reply(550, name);
                return;
        }
done:
        ack("DELE");
}

void
cwd(char *path)
{
        FILE *message;

        if (chdir(path) == -1)
                perror_reply(550, path);
        else {
                if ((message = fopen(_PATH_CWDMESG, "r")) != NULL) {
                        char line[LINE_MAX];

                        while (fgets(line, sizeof(line), message) != NULL) {
                                line[strcspn(line, "\n")] = '\0';
                                lreply(250, "%s", line);
                        }
                        (void) fclose(message);
                }
                ack("CWD");
        }
}

void
replydirname(const char *name, const char *message)
{
        char *p, *ep;
        char npath[PATH_MAX * 2];

        p = npath;
        ep = &npath[sizeof(npath) - 1];
        while (*name) {
                if (*name == '"') {
                        if (ep - p < 2)
                                break;
                        *p++ = *name++;
                        *p++ = '"';
                } else {
                        if (ep - p < 1)
                                break;
                        *p++ = *name++;
                }
        }
        *p = '\0';
        reply(257, "\"%s\" %s", npath, message);
}

void
makedir(const char *name)
{

        LOGCMD("mkdir", name);
        if (mkdir(name, 0777) == -1)
                perror_reply(550, name);
        else
                replydirname(name, "directory created.");
}

void
removedir(const char *name)
{

        LOGCMD("rmdir", name);
        if (rmdir(name) == -1)
                perror_reply(550, name);
        else
                ack("RMD");
}

void
pwd(void)
{
        char path[PATH_MAX];

        if (getcwd(path, sizeof(path)) == NULL)
                perror_reply(550, "Can't get current directory");
        else
                replydirname(path, "is current directory.");
}

char *
renamefrom(char *name)
{
        struct stat st;

        if (stat(name, &st) == -1) {
                perror_reply(550, name);
                return (NULL);
        }
        reply(350, "File exists, ready for destination name");
        return (name);
}

void
renamecmd(const char *from, const char *to)
{

        LOGCMD2("rename", from, to);
        if (rename(from, to) == -1)
                perror_reply(550, "rename");
        else
                ack("RNTO");
}

static void
dolog(struct sockaddr *sa)
{
        char hbuf[sizeof(remotehost)];

        if (getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf), NULL, 0, 0) == 0)
                (void) strlcpy(remotehost, hbuf, sizeof(remotehost));
        else
                (void) strlcpy(remotehost, "unknown", sizeof(remotehost));

        snprintf(proctitle, sizeof(proctitle), "%s: connected", remotehost);
        setproctitle("%s", proctitle);

        if (logging) {
                int error;
                error = getnameinfo(sa, sa->sa_len, hbuf, sizeof(hbuf),
                    NULL, 0, NI_NUMERICHOST);
                syslog(LOG_INFO, "connection from %s [%s]", remotehost,
                    error ? gai_strerror(error) : hbuf);
        }
}

/*
 * Record logout in wtmp file and exit with supplied status.
 * NOTE: because this is called from signal handlers it cannot
 *       use stdio (or call other functions that use stdio).
 */
void
dologout(int status)
{

        transflag = 0;

        if (logged_in) {
                sigprocmask(SIG_BLOCK, &allsigs, NULL);
                if (!nowtmp)
                        ftpdlogwtmp(ttyline, "", "");
                if (doutmp)
                        ftpd_logout(utmp.ut_line);
        }
        /* beware of flushing buffers after a SIGPIPE */
        _exit(status);
}

static void
sigurg(int signo)
{

        recvurg = 1;
}

static void
myoob(void)
{
        char *cp;
        int ret;

        /* only process if transfer occurring */
        if (!transflag)
                return;
        cp = tmpline;
        ret = get_line(cp, sizeof(tmpline)-1);
        if (ret == -1) {
                reply(221, "You could at least say goodbye.");
                dologout(0);
        } else if (ret == -2) {
                /* Ignore truncated command */
                return;
        }
        upper(cp);
        if (strcmp(cp, "ABOR\r\n") == 0) {
                tmpline[0] = '\0';
                reply(426, "Transfer aborted. Data connection closed.");
                reply(226, "Abort successful");
        }
        if (strcmp(cp, "STAT\r\n") == 0) {
                tmpline[0] = '\0';
                if (file_size != -1)
                        reply(213, "Status: %lld of %lld bytes transferred",
                            (long long)byte_count, (long long)file_size);
                else
                        reply(213, "Status: %lld bytes transferred",
                            (long long)byte_count);
        }
}

/*
 * Note: a response of 425 is not mentioned as a possible response to
 *      the PASV command in RFC959. However, it has been blessed as
 *      a legitimate response by Jon Postel in a telephone conversation
 *      with Rick Adams on 25 Jan 89.
 */
void
passive(void)
{
        socklen_t len;
        int on = 1;
        u_char *p, *a;

        if (pw == NULL) {
                reply(530, "Please login with USER and PASS");
                return;
        }
        if (pdata >= 0)
                close(pdata);
        /*
         * XXX
         * At this point, it would be nice to have an algorithm that
         * inserted a growing delay in an attack scenario.  Such a thing
         * would look like continual passive sockets being opened, but
         * nothing serious being done with them.  They're not used to
         * move data; the entire attempt is just to use tcp FIN_WAIT
         * resources.
         */
        pdata = socket(AF_INET, SOCK_STREAM, 0);
        if (pdata == -1) {
                perror_reply(425, "Can't open passive connection");
                return;
        }

        if (setsockopt(pdata, SOL_SOCKET, SO_KEEPALIVE,
            &on, sizeof(on)) == -1)
                goto pasv_error;

        on = IP_PORTRANGE_HIGH;
        if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
            &on, sizeof(on)) == -1)
                goto pasv_error;

        pasv_addr = ctrl_addr;
        pasv_addr.su_sin.sin_port = 0;
        if (bind(pdata, (struct sockaddr *)&pasv_addr,
            pasv_addr.su_len) == -1)
                goto pasv_error;

        len = sizeof(pasv_addr);
        if (getsockname(pdata, (struct sockaddr *)&pasv_addr, &len) == -1)
                goto pasv_error;
        if (listen(pdata, 1) == -1)
                goto pasv_error;
        a = (u_char *)&pasv_addr.su_sin.sin_addr;
        p = (u_char *)&pasv_addr.su_sin.sin_port;

        reply(227, "Entering Passive Mode (%u,%u,%u,%u,%u,%u)", a[0],
            a[1], a[2], a[3], p[0], p[1]);
        return;

pasv_error:
        perror_reply(425, "Can't open passive connection");
        (void) close(pdata);
        pdata = -1;
        return;
}

int
epsvproto2af(int proto)
{

        switch (proto) {
        case 1: return AF_INET;
        case 2: return AF_INET6;
        default: return -1;
        }
}

int
af2epsvproto(int af)
{

        switch (af) {
        case AF_INET:   return 1;
        case AF_INET6:  return 2;
        default:        return -1;
        }
}

/*
 * 228 Entering Long Passive Mode (af, hal, h1, h2, h3,..., pal, p1, p2...)
 * 229 Entering Extended Passive Mode (|||port|)
 */
void
long_passive(const char *cmd, int pf)
{
        socklen_t len;
        int on = 1;
        u_char *p, *a;

        if (!logged_in) {
                syslog(LOG_NOTICE, "long passive but not logged in");
                reply(503, "Login with USER first.");
                return;
        }

        if (pf != PF_UNSPEC && ctrl_addr.su_family != pf) {
                /*
                 * XXX
                 * only EPRT/EPSV ready clients will understand this
                 */
                if (strcmp(cmd, "EPSV") != 0)
                        reply(501, "Network protocol mismatch"); /*XXX*/
                else
                        epsv_protounsupp("Network protocol mismatch");

                return;
        }

        if (pdata >= 0)
                close(pdata);
        /*
         * XXX
         * At this point, it would be nice to have an algorithm that
         * inserted a growing delay in an attack scenario.  Such a thing
         * would look like continual passive sockets being opened, but
         * nothing serious being done with them.  They not used to move
         * data; the entire attempt is just to use tcp FIN_WAIT
         * resources.
         */
        pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
        if (pdata == -1) {
                perror_reply(425, "Can't open passive connection");
                return;
        }

        if (setsockopt(pdata, SOL_SOCKET, SO_KEEPALIVE,
            &on, sizeof(on)) == -1)
                goto pasv_error;

        switch (ctrl_addr.su_family) {
        case AF_INET:
                on = IP_PORTRANGE_HIGH;
                if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
                    &on, sizeof(on)) == -1)
                        goto pasv_error;
                break;
        case AF_INET6:
                on = IPV6_PORTRANGE_HIGH;
                if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
                    &on, sizeof(on)) == -1)
                        goto pasv_error;
                break;
        }

        pasv_addr = ctrl_addr;
        pasv_addr.su_port = 0;
        if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) == -1)
                goto pasv_error;
        len = pasv_addr.su_len;
        if (getsockname(pdata, (struct sockaddr *)&pasv_addr, &len) == -1)
                goto pasv_error;
        if (listen(pdata, 1) == -1)
                goto pasv_error;
        p = (u_char *)&pasv_addr.su_port;

        if (strcmp(cmd, "LPSV") == 0) {
                switch (pasv_addr.su_family) {
                case AF_INET:
                        a = (u_char *)&pasv_addr.su_sin.sin_addr;
                        reply(228,
                            "Entering Long Passive Mode (%u,%u,%u,%u,%u,%u,%u,%u,%u)",
                            4, 4, a[0], a[1], a[2], a[3], 2, p[0], p[1]);
                        return;
                case AF_INET6:
                        a = (u_char *)&pasv_addr.su_sin6.sin6_addr;
                        reply(228,
                            "Entering Long Passive Mode (%u,%u,%u,%u,%u,%u,"
                            "%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u)",
                                6, 16, a[0], a[1], a[2], a[3], a[4],
                                a[5], a[6], a[7], a[8], a[9], a[10],
                                a[11], a[12], a[13], a[14], a[15],
                                2, p[0], p[1]);
                        return;
                }
        } else if (strcmp(cmd, "EPSV") == 0) {
                switch (pasv_addr.su_family) {
                case AF_INET:
                case AF_INET6:
                        reply(229, "Entering Extended Passive Mode (|||%u|)",
                            ntohs(pasv_addr.su_port));
                        return;
                }
        } else {
                /* more proper error code? */
        }

  pasv_error:
        perror_reply(425, "Can't open passive connection");
        (void) close(pdata);
        pdata = -1;
        return;
}

/*
 * EPRT |proto|addr|port|
 */
int
extended_port(const char *arg)
{
        char *tmp = NULL;
        char *result[3];
        char *p, *q;
        char delim;
        struct addrinfo hints;
        struct addrinfo *res = NULL;
        int i;
        unsigned long proto;

        if (epsvall) {
                reply(501, "EPRT disallowed after EPSV ALL");
                return -1;
        }

        usedefault = 0;
        if (pdata >= 0) {
                (void) close(pdata);
                pdata = -1;
        }

        tmp = strdup(arg);
        if (!tmp) {
                fatal("not enough core.");
                /*NOTREACHED*/
        }
        p = tmp;
        delim = p[0];
        p++;
        memset(result, 0, sizeof(result));
        for (i = 0; i < 3; i++) {
                q = strchr(p, delim);
                if (!q || *q != delim)
                        goto parsefail;
                *q++ = '\0';
                result[i] = p;
                p = q;
        }

        /* some more sanity check */
        p = NULL;
        (void)strtoul(result[2], &p, 10);
        if (!*result[2] || *p)
                goto protounsupp;
        p = NULL;
        proto = strtoul(result[0], &p, 10);
        if (!*result[0] || *p)
                goto protounsupp;

        memset(&hints, 0, sizeof(hints));
        hints.ai_family = epsvproto2af((int)proto);
        if (hints.ai_family < 0)
                goto protounsupp;
        hints.ai_socktype = SOCK_STREAM;
        hints.ai_flags = AI_NUMERICHOST;        /*no DNS*/
        if (getaddrinfo(result[1], result[2], &hints, &res))
                goto parsefail;
        if (res->ai_next)
                goto parsefail;
        if (sizeof(data_dest) < res->ai_addrlen)
                goto parsefail;
        memcpy(&data_dest, res->ai_addr, res->ai_addrlen);
        if (his_addr.su_family == AF_INET6 &&
            data_dest.su_family == AF_INET6) {
                /* XXX more sanity checks! */
                data_dest.su_sin6.sin6_scope_id =
                    his_addr.su_sin6.sin6_scope_id;
        }
        if (pdata >= 0) {
                (void) close(pdata);
                pdata = -1;
        }
        reply(200, "EPRT command successful.");

        free(tmp);
        if (res)
                freeaddrinfo(res);
        return 0;

parsefail:
        reply(500, "Invalid argument, rejected.");
        usedefault = 1;
        free(tmp);
        if (res)
                freeaddrinfo(res);
        return -1;

protounsupp:
        epsv_protounsupp("Protocol not supported");
        usedefault = 1;
        free(tmp);
        if (res)
                freeaddrinfo(res);
        return -1;
}

/*
 * 522 Protocol not supported (proto,...)
 * as we assume address family for control and data connections are the same,
 * we do not return the list of address families we support - instead, we
 * return the address family of the control connection.
 */
void
epsv_protounsupp(const char *message)
{
        int proto;

        proto = af2epsvproto(ctrl_addr.su_family);
        if (proto < 0)
                reply(501, "%s", message);      /*XXX*/
        else
                reply(522, "%s, use (%d)", message, proto);
}

/*
 * Generate unique name for file with basename "local".
 * The file named "local" is already known to exist.
 * Generates failure reply on error.
 */
static int
guniquefd(const char *local, char **nam)
{
        static char new[PATH_MAX];
        struct stat st;
        size_t len;
        int count, fd;
        char *cp;

        cp = strrchr(local, '/');
        if (cp)
                *cp = '\0';
        if (stat(cp ? local : ".", &st) == -1) {
                perror_reply(553, cp ? local : ".");
                return (-1);
        }
        if (cp)
                *cp = '/';
        len = strlcpy(new, local, sizeof(new));
        if (len+2+1 >= sizeof(new)-1)
                return (-1);
        cp = new + len;
        *cp++ = '.';
        for (count = 1; count < 100; count++) {
                (void)snprintf(cp, sizeof(new) - (cp - new), "%d", count);
                fd = open(new, O_RDWR|O_CREAT|O_EXCL, 0666);
                if (fd == -1)
                        continue;
                if (nam)
                        *nam = new;
                return (fd);
        }
        reply(452, "Unique file name cannot be created.");
        return (-1);
}

/*
 * Format and send reply containing system error number.
 */
void
perror_reply(int code, const char *string)
{

        reply(code, "%s: %s.", string, strerror(errno));
}

static char *onefile[] = {
        "",
        0
};

void
send_file_list(char *whichf)
{
        struct stat st;
        DIR *dirp = NULL;
        struct dirent *dir;
        FILE *dout = NULL;
        char **dirlist;
        char *dirname;
        int simple = 0;
        volatile int freeglob = 0;
        glob_t gl;
        size_t prefixlen;

        if (strpbrk(whichf, "~{[*?") != NULL) {
                memset(&gl, 0, sizeof(gl));
                freeglob = 1;
                if (glob(whichf,
                    GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT,
                    0, &gl)) {
                        reply(550, "not found");
                        goto out;
                } else if (gl.gl_pathc == 0) {
                        errno = ENOENT;
                        perror_reply(550, whichf);
                        goto out;
                }
                dirlist = gl.gl_pathv;
        } else {
                onefile[0] = whichf;
                dirlist = onefile;
                simple = 1;
        }

        while ((dirname = *dirlist++)) {
                if (stat(dirname, &st) == -1) {
                        /*
                         * If user typed "ls -l", etc, and the client
                         * used NLST, do what the user meant.
                         */
                        if (dirname[0] == '-' && *dirlist == NULL &&
                            transflag == 0) {
                                retrieve(RET_FILE, dirname);
                                goto out;
                        }
                        perror_reply(550, whichf);
                        if (dout != NULL) {
                                (void) fclose(dout);
                                transflag = 0;
                                data = -1;
                                pdata = -1;
                        }
                        goto out;
                }

                if (S_ISREG(st.st_mode)) {
                        if (dout == NULL) {
                                dout = dataconn("file list", -1, "w");
                                if (dout == NULL)
                                        goto out;
                                transflag++;
                        }
                        fprintf(dout, "%s%s\n", dirname,
                                type == TYPE_A ? "\r" : "");
                        byte_count += strlen(dirname) + 1;
                        continue;
                } else if (!S_ISDIR(st.st_mode))
                        continue;

                if ((dirp = opendir(dirname)) == NULL)
                        continue;

                if (dirname[0] == '.' && dirname[1] == '\0')
                        prefixlen = 0;
                else
                        prefixlen = strlen(dirname) + 1;
                while ((dir = readdir(dirp)) != NULL) {
                        if (recvurg) {
                                myoob();
                                recvurg = 0;
                                transflag = 0;
                                goto out;
                        }

                        if (dir->d_name[0] == '.' && dir->d_namlen == 1)
                                continue;
                        if (dir->d_name[0] == '.' && dir->d_name[1] == '.' &&
                            dir->d_namlen == 2)
                                continue;

                        /*
                         * We have to do a stat to insure it's
                         * not a directory or special file.
                         */
                        if (simple ||
                            (fstatat(dirfd(dirp), dir->d_name, &st, 0) == 0 &&
                            S_ISREG(st.st_mode))) {
                                if (dout == NULL) {
                                        dout = dataconn("file list", -1, "w");
                                        if (dout == NULL)
                                                goto out;
                                        transflag++;
                                }

                                if (prefixlen) {
                                        fprintf(dout, "%s/", dirname);
                                        byte_count += prefixlen;
                                }
                                fprintf(dout, "%s%s\n", dir->d_name,
                                    type == TYPE_A ? "\r" : "");
                                byte_count += dir->d_namlen + 1;
                        }
                }
                (void) closedir(dirp);
        }

        if (dout == NULL)
                reply(550, "No files found.");
        else if (ferror(dout) != 0)
                perror_reply(550, "Data connection");
        else
                reply(226, "Transfer complete.");

        transflag = 0;
        if (dout != NULL)
                (void) fclose(dout);
        else {
                if (pdata >= 0)
                        close(pdata);
        }
        data = -1;
        pdata = -1;
out:
        if (freeglob) {
                freeglob = 0;
                globfree(&gl);
        }
}

static void
reapchild(int signo)
{
        int save_errno = errno;
        int rval;

        do {
                rval = waitpid(-1, NULL, WNOHANG);
        } while (rval > 0 || (rval == -1 && errno == EINTR));
        errno = save_errno;
}

void
logxfer(const char *name, off_t size, time_t start)
{
        char buf[400 + (HOST_NAME_MAX+1)*4 + PATH_MAX*4];
        char dir[PATH_MAX], path[PATH_MAX], rpath[PATH_MAX];
        char vremotehost[(HOST_NAME_MAX+1)*4], vpath[PATH_MAX*4];
        char *vpw;
        time_t now;
        int len;

        if ((statfd >= 0) && (getcwd(dir, sizeof(dir)) != NULL)) {
                char *cnow;

                time(&now);
                cnow = ctime(&now);

                vpw = malloc(strlen(guest ? guestpw : pw->pw_name) * 4 + 1);
                if (vpw == NULL)
                        return;

                snprintf(path, sizeof(path), "%s/%s", dir, name);
                if (realpath(path, rpath) == NULL)
                        strlcpy(rpath, path, sizeof(rpath));
                strvis(vpath, rpath, VIS_SAFE|VIS_NOSLASH);

                strvis(vremotehost, remotehost, VIS_SAFE|VIS_NOSLASH);
                strvis(vpw, guest? guestpw : pw->pw_name, VIS_SAFE|VIS_NOSLASH);

                len = snprintf(buf, sizeof(buf),
                    "%.24s %lld %s %lld %s %c %s %c %c %s ftp %d %s %s\n",
                    cnow ? cnow : "?",
                    (long long)(now - start + (now == start)),
                    vremotehost, (long long)size, vpath,
                    ((type == TYPE_A) ? 'a' : 'b'), "*" /* none yet */,
                    'o', ((guest) ? 'a' : 'r'),
                    vpw, 0 /* none yet */,
                    ((guest) ? "*" : pw->pw_name), dhostname);
                free(vpw);

                if (len < 0 || len >= sizeof(buf)) {
                        if ((len = strlen(buf)) == 0)
                                return;         /* should not happen */
                        buf[len - 1] = '\n';
                }
                write(statfd, buf, len);
        }
}

void
set_slave_signals(void)
{
        struct sigaction sa;

        sigemptyset(&sa.sa_mask);
        sa.sa_flags = SA_RESTART;

        sa.sa_handler = SIG_DFL;
        (void) sigaction(SIGCHLD, &sa, NULL);

        sa.sa_handler = sigurg;
        sa.sa_flags = 0;                /* don't restart syscalls for SIGURG */
        (void) sigaction(SIGURG, &sa, NULL);

        sigfillset(&sa.sa_mask);        /* block all signals in handler */
        sa.sa_flags = SA_RESTART;
        sa.sa_handler = sigquit;
        (void) sigaction(SIGHUP, &sa, NULL);
        (void) sigaction(SIGINT, &sa, NULL);
        (void) sigaction(SIGQUIT, &sa, NULL);
        (void) sigaction(SIGTERM, &sa, NULL);

        sa.sa_handler = lostconn;
        (void) sigaction(SIGPIPE, &sa, NULL);

        sa.sa_handler = toolong;
        (void) sigaction(SIGALRM, &sa, NULL);

        if (fcntl(fileno(stdin), F_SETOWN, getpid()) == -1)
                syslog(LOG_ERR, "fcntl F_SETOWN: %m");
}

/*
 * Allocate space and return a copy of the specified dir.
 * If 'dir' begins with a tilde (~), expand it.
 */
char *
copy_dir(char *dir, struct passwd *pw)
{
        char *cp;
        char *newdir;
        char *user = NULL;

        /* Nothing to expand */
        if (dir[0] != '~')
                return (strdup(dir));

        /* "dir" is of form ~user/some/dir, lookup user. */
        if (dir[1] != '/' && dir[1] != '\0') {
                if ((cp = strchr(dir + 1, '/')) == NULL)
                        cp = dir + strlen(dir);
                if ((user = malloc((size_t)(cp - dir))) == NULL)
                        return (NULL);
                strlcpy(user, dir + 1, (size_t)(cp - dir));

                /* Only do lookup if it is a different user. */
                if (strcmp(user, pw->pw_name) != 0) {
                        if ((pw = getpwnam(user)) == NULL) {
                                /* No such user, interpret literally */
                                free(user);
                                return(strdup(dir));
                        }
                }
                free(user);
        }

        /*
         * If there is no directory separator (/) then it is just pw_dir.
         * Otherwise, replace ~foo with pw_dir.
         */
        if ((cp = strchr(dir + 1, '/')) == NULL) {
                newdir = strdup(pw->pw_dir);
        } else {
                if (asprintf(&newdir, "%s%s", pw->pw_dir, cp) == -1)
                        return (NULL);
        }

        return(newdir);
}