Clarify the comment at the top of scp.c to make the licensing

[u/mdw/putty] / scp.c

/*
 * scp.c  -  Scp (Secure Copy) client for PuTTY.
 * Joris van Rantwijk, Simon Tatham
 *
 * This is mainly based on ssh-1.2.26/scp.c by Timo Rinne & Tatu Ylonen.
 * They, in turn, used stuff from BSD rcp.
 * 
 * (SGT, 2001-09-10: Joris van Rantwijk assures me that although
 * this file as originally submitted was inspired by, and
 * _structurally_ based on, ssh-1.2.26's scp.c, there wasn't any
 * actual code duplicated, so the above comment shouldn't give rise
 * to licensing issues.)
 */

#include <windows.h>
#ifndef AUTO_WINSOCK
#ifdef WINSOCK_TWO
#include <winsock2.h>
#else
#include <winsock.h>
#endif
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <time.h>
#include <assert.h>

#define PUTTY_DO_GLOBALS
#include "putty.h"
#include "ssh.h"
#include "sftp.h"
#include "winstuff.h"
#include "storage.h"

#define TIME_POSIX_TO_WIN(t, ft) (*(LONGLONG*)&(ft) = \
        ((LONGLONG) (t) + (LONGLONG) 11644473600) * (LONGLONG) 10000000)
#define TIME_WIN_TO_POSIX(ft, t) ((t) = (unsigned long) \
        ((*(LONGLONG*)&(ft)) / (LONGLONG) 10000000 - (LONGLONG) 11644473600))

/* GUI Adaptation - Sept 2000 */
#define   WM_APP_BASE           0x8000
#define   WM_STD_OUT_CHAR       ( WM_APP_BASE+400 )
#define   WM_STD_ERR_CHAR       ( WM_APP_BASE+401 )
#define   WM_STATS_CHAR         ( WM_APP_BASE+402 )
#define   WM_STATS_SIZE         ( WM_APP_BASE+403 )
#define   WM_STATS_PERCENT      ( WM_APP_BASE+404 )
#define   WM_STATS_ELAPSED      ( WM_APP_BASE+405 )
#define   WM_RET_ERR_CNT        ( WM_APP_BASE+406 )
#define   WM_LS_RET_ERR_CNT     ( WM_APP_BASE+407 )

static int list = 0;
static int verbose = 0;
static int recursive = 0;
static int preserve = 0;
static int targetshouldbedirectory = 0;
static int statistics = 1;
static int portnumber = 0;
static int prev_stats_len = 0;
static int scp_unsafe_mode = 0;
static char *password = NULL;
static int errs = 0;
/* GUI Adaptation - Sept 2000 */
#define NAME_STR_MAX 2048
static char statname[NAME_STR_MAX + 1];
static unsigned long statsize = 0;
static int statperct = 0;
static unsigned long statelapsed = 0;
static int gui_mode = 0;
static char *gui_hwnd = NULL;
static int using_sftp = 0;

static void source(char *src);
static void rsource(char *src);
static void sink(char *targ, char *src);
/* GUI Adaptation - Sept 2000 */
static void tell_char(FILE * stream, char c);
static void tell_str(FILE * stream, char *str);
static void tell_user(FILE * stream, char *fmt, ...);
static void gui_update_stats(char *name, unsigned long size,
                             int percentage, unsigned long elapsed);

/*
 * The maximum amount of queued data we accept before we stop and
 * wait for the server to process some.
 */
#define MAX_SCP_BUFSIZE 16384

void logevent(char *string)
{
}

void ldisc_send(char *buf, int len)
{
    /*
     * This is only here because of the calls to ldisc_send(NULL,
     * 0) in ssh.c. Nothing in PSCP actually needs to use the ldisc
     * as an ldisc. So if we get called with any real data, I want
     * to know about it.
     */
    assert(len == 0);
}

void verify_ssh_host_key(char *host, int port, char *keytype,
                         char *keystr, char *fingerprint)
{
    int ret;
    HANDLE hin;
    DWORD savemode, i;

    static const char absentmsg[] =
        "The server's host key is not cached in the registry. You\n"
        "have no guarantee that the server is the computer you\n"
        "think it is.\n"
        "The server's key fingerprint is:\n"
        "%s\n"
        "If you trust this host, enter \"y\" to add the key to\n"
        "PuTTY's cache and carry on connecting.\n"
        "If you want to carry on connecting just once, without\n"
        "adding the key to the cache, enter \"n\".\n"
        "If you do not trust this host, press Return to abandon the\n"
        "connection.\n"
        "Store key in cache? (y/n) ";

    static const char wrongmsg[] =
        "WARNING - POTENTIAL SECURITY BREACH!\n"
        "The server's host key does not match the one PuTTY has\n"
        "cached in the registry. This means that either the\n"
        "server administrator has changed the host key, or you\n"
        "have actually connected to another computer pretending\n"
        "to be the server.\n"
        "The new key fingerprint is:\n"
        "%s\n"
        "If you were expecting this change and trust the new key,\n"
        "enter \"y\" to update PuTTY's cache and continue connecting.\n"
        "If you want to carry on connecting but without updating\n"
        "the cache, enter \"n\".\n"
        "If you want to abandon the connection completely, press\n"
        "Return to cancel. Pressing Return is the ONLY guaranteed\n"
        "safe choice.\n"
        "Update cached key? (y/n, Return cancels connection) ";

    static const char abandoned[] = "Connection abandoned.\n";

    char line[32];

    /*
     * Verify the key against the registry.
     */
    ret = verify_host_key(host, port, keytype, keystr);

    if (ret == 0)                      /* success - key matched OK */
        return;

    if (ret == 2) {                    /* key was different */
        fprintf(stderr, wrongmsg, fingerprint);
        fflush(stderr);
    }
    if (ret == 1) {                    /* key was absent */
        fprintf(stderr, absentmsg, fingerprint);
        fflush(stderr);
    }

    hin = GetStdHandle(STD_INPUT_HANDLE);
    GetConsoleMode(hin, &savemode);
    SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
                         ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
    ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
    SetConsoleMode(hin, savemode);

    if (line[0] != '\0' && line[0] != '\r' && line[0] != '\n') {
        if (line[0] == 'y' || line[0] == 'Y')
            store_host_key(host, port, keytype, keystr);
    } else {
        fprintf(stderr, abandoned);
        exit(0);
    }
}

/*
 * Ask whether the selected cipher is acceptable (since it was
 * below the configured 'warn' threshold).
 * cs: 0 = both ways, 1 = client->server, 2 = server->client
 */
void askcipher(char *ciphername, int cs)
{
    HANDLE hin;
    DWORD savemode, i;

    static const char msg[] =
        "The first %scipher supported by the server is\n"
        "%s, which is below the configured warning threshold.\n"
        "Continue with connection? (y/n) ";
    static const char abandoned[] = "Connection abandoned.\n";

    char line[32];

    fprintf(stderr, msg,
            (cs == 0) ? "" :
            (cs == 1) ? "client-to-server " :
                        "server-to-client ",
            ciphername);
    fflush(stderr);

    hin = GetStdHandle(STD_INPUT_HANDLE);
    GetConsoleMode(hin, &savemode);
    SetConsoleMode(hin, (savemode | ENABLE_ECHO_INPUT |
                         ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT));
    ReadFile(hin, line, sizeof(line) - 1, &i, NULL);
    SetConsoleMode(hin, savemode);

    if (line[0] == 'y' || line[0] == 'Y') {
        return;
    } else {
        fprintf(stderr, abandoned);
        exit(0);
    }
}

/* GUI Adaptation - Sept 2000 */
static void send_msg(HWND h, UINT message, WPARAM wParam)
{
    while (!PostMessage(h, message, wParam, 0))
        SleepEx(1000, TRUE);
}

static void tell_char(FILE * stream, char c)
{
    if (!gui_mode)
        fputc(c, stream);
    else {
        unsigned int msg_id = WM_STD_OUT_CHAR;
        if (stream == stderr)
            msg_id = WM_STD_ERR_CHAR;
        send_msg((HWND) atoi(gui_hwnd), msg_id, (WPARAM) c);
    }
}

static void tell_str(FILE * stream, char *str)
{
    unsigned int i;

    for (i = 0; i < strlen(str); ++i)
        tell_char(stream, str[i]);
}

static void tell_user(FILE * stream, char *fmt, ...)
{
    char str[0x100];                   /* Make the size big enough */
    va_list ap;
    va_start(ap, fmt);
    vsprintf(str, fmt, ap);
    va_end(ap);
    strcat(str, "\n");
    tell_str(stream, str);
}

static void gui_update_stats(char *name, unsigned long size,
                             int percentage, unsigned long elapsed)
{
    unsigned int i;

    if (strcmp(name, statname) != 0) {
        for (i = 0; i < strlen(name); ++i)
            send_msg((HWND) atoi(gui_hwnd), WM_STATS_CHAR,
                     (WPARAM) name[i]);
        send_msg((HWND) atoi(gui_hwnd), WM_STATS_CHAR, (WPARAM) '\n');
        strcpy(statname, name);
    }
    if (statsize != size) {
        send_msg((HWND) atoi(gui_hwnd), WM_STATS_SIZE, (WPARAM) size);
        statsize = size;
    }
    if (statelapsed != elapsed) {
        send_msg((HWND) atoi(gui_hwnd), WM_STATS_ELAPSED,
                 (WPARAM) elapsed);
        statelapsed = elapsed;
    }
    if (statperct != percentage) {
        send_msg((HWND) atoi(gui_hwnd), WM_STATS_PERCENT,
                 (WPARAM) percentage);
        statperct = percentage;
    }
}

/*
 *  Print an error message and perform a fatal exit.
 */
void fatalbox(char *fmt, ...)
{
    char str[0x100];                   /* Make the size big enough */
    va_list ap;
    va_start(ap, fmt);
    strcpy(str, "Fatal: ");
    vsprintf(str + strlen(str), fmt, ap);
    va_end(ap);
    strcat(str, "\n");
    tell_str(stderr, str);
    errs++;

    if (gui_mode) {
        unsigned int msg_id = WM_RET_ERR_CNT;
        if (list)
            msg_id = WM_LS_RET_ERR_CNT;
        while (!PostMessage
               ((HWND) atoi(gui_hwnd), msg_id, (WPARAM) errs,
                0 /*lParam */ ))SleepEx(1000, TRUE);
    }

    exit(1);
}
void connection_fatal(char *fmt, ...)
{
    char str[0x100];                   /* Make the size big enough */
    va_list ap;
    va_start(ap, fmt);
    strcpy(str, "Fatal: ");
    vsprintf(str + strlen(str), fmt, ap);
    va_end(ap);
    strcat(str, "\n");
    tell_str(stderr, str);
    errs++;

    if (gui_mode) {
        unsigned int msg_id = WM_RET_ERR_CNT;
        if (list)
            msg_id = WM_LS_RET_ERR_CNT;
        while (!PostMessage
               ((HWND) atoi(gui_hwnd), msg_id, (WPARAM) errs,
                0 /*lParam */ ))SleepEx(1000, TRUE);
    }

    exit(1);
}

/*
 * Be told what socket we're supposed to be using.
 */
static SOCKET scp_ssh_socket;
char *do_select(SOCKET skt, int startup)
{
    if (startup)
        scp_ssh_socket = skt;
    else
        scp_ssh_socket = INVALID_SOCKET;
    return NULL;
}
extern int select_result(WPARAM, LPARAM);

/*
 * Receive a block of data from the SSH link. Block until all data
 * is available.
 *
 * To do this, we repeatedly call the SSH protocol module, with our
 * own trap in from_backend() to catch the data that comes back. We
 * do this until we have enough data.
 */

static unsigned char *outptr;          /* where to put the data */
static unsigned outlen;                /* how much data required */
static unsigned char *pending = NULL;  /* any spare data */
static unsigned pendlen = 0, pendsize = 0;      /* length and phys. size of buffer */
int from_backend(int is_stderr, char *data, int datalen)
{
    unsigned char *p = (unsigned char *) data;
    unsigned len = (unsigned) datalen;

    /*
     * stderr data is just spouted to local stderr and otherwise
     * ignored.
     */
    if (is_stderr) {
        fwrite(data, 1, len, stderr);
        return 0;
    }

    inbuf_head = 0;

    /*
     * If this is before the real session begins, just return.
     */
    if (!outptr)
        return 0;

    if (outlen > 0) {
        unsigned used = outlen;
        if (used > len)
            used = len;
        memcpy(outptr, p, used);
        outptr += used;
        outlen -= used;
        p += used;
        len -= used;
    }

    if (len > 0) {
        if (pendsize < pendlen + len) {
            pendsize = pendlen + len + 4096;
            pending = (pending ? srealloc(pending, pendsize) :
                       smalloc(pendsize));
            if (!pending)
                fatalbox("Out of memory");
        }
        memcpy(pending + pendlen, p, len);
        pendlen += len;
    }

    return 0;
}
static int scp_process_network_event(void)
{
    fd_set readfds;

    FD_ZERO(&readfds);
    FD_SET(scp_ssh_socket, &readfds);
    if (select(1, &readfds, NULL, NULL, NULL) < 0)
        return 0;                      /* doom */
    select_result((WPARAM) scp_ssh_socket, (LPARAM) FD_READ);
    return 1;
}
static int ssh_scp_recv(unsigned char *buf, int len)
{
    outptr = buf;
    outlen = len;

    /*
     * See if the pending-input block contains some of what we
     * need.
     */
    if (pendlen > 0) {
        unsigned pendused = pendlen;
        if (pendused > outlen)
            pendused = outlen;
        memcpy(outptr, pending, pendused);
        memmove(pending, pending + pendused, pendlen - pendused);
        outptr += pendused;
        outlen -= pendused;
        pendlen -= pendused;
        if (pendlen == 0) {
            pendsize = 0;
            sfree(pending);
            pending = NULL;
        }
        if (outlen == 0)
            return len;
    }

    while (outlen > 0) {
        if (!scp_process_network_event())
            return 0;                  /* doom */
    }

    return len;
}

/*
 * Loop through the ssh connection and authentication process.
 */
static void ssh_scp_init(void)
{
    if (scp_ssh_socket == INVALID_SOCKET)
        return;
    while (!back->sendok()) {
        fd_set readfds;
        FD_ZERO(&readfds);
        FD_SET(scp_ssh_socket, &readfds);
        if (select(1, &readfds, NULL, NULL, NULL) < 0)
            return;                    /* doom */
        select_result((WPARAM) scp_ssh_socket, (LPARAM) FD_READ);
    }
    using_sftp = !ssh_fallback_cmd;
}

/*
 *  Print an error message and exit after closing the SSH link.
 */
static void bump(char *fmt, ...)
{
    char str[0x100];                   /* Make the size big enough */
    va_list ap;
    va_start(ap, fmt);
    strcpy(str, "Fatal: ");
    vsprintf(str + strlen(str), fmt, ap);
    va_end(ap);
    strcat(str, "\n");
    tell_str(stderr, str);
    errs++;

    if (back != NULL && back->socket() != NULL) {
        char ch;
        back->special(TS_EOF);
        ssh_scp_recv(&ch, 1);
    }

    if (gui_mode) {
        unsigned int msg_id = WM_RET_ERR_CNT;
        if (list)
            msg_id = WM_LS_RET_ERR_CNT;
        while (!PostMessage
               ((HWND) atoi(gui_hwnd), msg_id, (WPARAM) errs,
                0 /*lParam */ ))SleepEx(1000, TRUE);
    }

    exit(1);
}

static int get_line(const char *prompt, char *str, int maxlen, int is_pw)
{
    HANDLE hin, hout;
    DWORD savemode, newmode, i;

    if (is_pw && password) {
        static int tried_once = 0;

        if (tried_once) {
            return 0;
        } else {
            strncpy(str, password, maxlen);
            str[maxlen - 1] = '\0';
            tried_once = 1;
            return 1;
        }
    }

    /* GUI Adaptation - Sept 2000 */
    if (gui_mode) {
        if (maxlen > 0)
            str[0] = '\0';
    } else {
        hin = GetStdHandle(STD_INPUT_HANDLE);
        hout = GetStdHandle(STD_OUTPUT_HANDLE);
        if (hin == INVALID_HANDLE_VALUE || hout == INVALID_HANDLE_VALUE)
            bump("Cannot get standard input/output handles");

        GetConsoleMode(hin, &savemode);
        newmode = savemode | ENABLE_PROCESSED_INPUT | ENABLE_LINE_INPUT;
        if (is_pw)
            newmode &= ~ENABLE_ECHO_INPUT;
        else
            newmode |= ENABLE_ECHO_INPUT;
        SetConsoleMode(hin, newmode);

        WriteFile(hout, prompt, strlen(prompt), &i, NULL);
        ReadFile(hin, str, maxlen - 1, &i, NULL);

        SetConsoleMode(hin, savemode);

        if ((int) i > maxlen)
            i = maxlen - 1;
        else
            i = i - 2;
        str[i] = '\0';

        if (is_pw)
            WriteFile(hout, "\r\n", 2, &i, NULL);
    }

    return 1;
}

/*
 *  Open an SSH connection to user@host and execute cmd.
 */
static void do_cmd(char *host, char *user, char *cmd)
{
    char *err, *realhost;
    DWORD namelen;

    if (host == NULL || host[0] == '\0')
        bump("Empty host name");

    /* Try to load settings for this host */
    do_defaults(host, &cfg);
    if (cfg.host[0] == '\0') {
        /* No settings for this host; use defaults */
        do_defaults(NULL, &cfg);
        strncpy(cfg.host, host, sizeof(cfg.host) - 1);
        cfg.host[sizeof(cfg.host) - 1] = '\0';
        cfg.port = 22;
    }

    /* Set username */
    if (user != NULL && user[0] != '\0') {
        strncpy(cfg.username, user, sizeof(cfg.username) - 1);
        cfg.username[sizeof(cfg.username) - 1] = '\0';
    } else if (cfg.username[0] == '\0') {
        namelen = 0;
        if (GetUserName(user, &namelen) == FALSE)
            bump("Empty user name");
        user = smalloc(namelen * sizeof(char));
        GetUserName(user, &namelen);
        if (verbose)
            tell_user(stderr, "Guessing user name: %s", user);
        strncpy(cfg.username, user, sizeof(cfg.username) - 1);
        cfg.username[sizeof(cfg.username) - 1] = '\0';
        free(user);
    }

    if (cfg.protocol != PROT_SSH)
        cfg.port = 22;

    if (portnumber)
        cfg.port = portnumber;

    /*
     * Attempt to start the SFTP subsystem as a first choice,
     * falling back to the provided scp command if that fails.
     */
    strcpy(cfg.remote_cmd, "sftp");
    cfg.ssh_subsys = TRUE;
    cfg.remote_cmd_ptr2 = cmd;
    cfg.ssh_subsys2 = FALSE;
    cfg.nopty = TRUE;

    back = &ssh_backend;

    err = back->init(cfg.host, cfg.port, &realhost);
    if (err != NULL)
        bump("ssh_init: %s", err);
    ssh_scp_init();
    if (verbose && realhost != NULL)
        tell_user(stderr, "Connected to %s\n", realhost);
    sfree(realhost);
}

/*
 *  Update statistic information about current file.
 */
static void print_stats(char *name, unsigned long size, unsigned long done,
                        time_t start, time_t now)
{
    float ratebs;
    unsigned long eta;
    char etastr[10];
    int pct;
    int len;

    /* GUI Adaptation - Sept 2000 */
    if (gui_mode)
        gui_update_stats(name, size, (int) (100 * (done * 1.0 / size)),
                         (unsigned long) difftime(now, start));
    else {
        if (now > start)
            ratebs = (float) done / (now - start);
        else
            ratebs = (float) done;

        if (ratebs < 1.0)
            eta = size - done;
        else
            eta = (unsigned long) ((size - done) / ratebs);
        sprintf(etastr, "%02ld:%02ld:%02ld",
                eta / 3600, (eta % 3600) / 60, eta % 60);

        pct = (int) (100 * (done * 1.0 / size));

        len = printf("\r%-25.25s | %10ld kB | %5.1f kB/s | ETA: %8s | %3d%%",
                     name, done / 1024, ratebs / 1024.0, etastr, pct);
        if (len < prev_stats_len)
            printf("%*s", prev_stats_len - len, "");
        prev_stats_len = len;

        if (done == size)
            printf("\n");
    }
}

/*
 *  Find a colon in str and return a pointer to the colon.
 *  This is used to separate hostname from filename.
 */
static char *colon(char *str)
{
    /* We ignore a leading colon, since the hostname cannot be
       empty. We also ignore a colon as second character because
       of filenames like f:myfile.txt. */
    if (str[0] == '\0' || str[0] == ':' || str[1] == ':')
        return (NULL);
    while (*str != '\0' && *str != ':' && *str != '/' && *str != '\\')
        str++;
    if (*str == ':')
        return (str);
    else
        return (NULL);
}

/*
 * Return a pointer to the portion of str that comes after the last
 * slash (or backslash or colon, if `local' is TRUE).
 */
static char *stripslashes(char *str, int local)
{
    char *p;

    if (local) {
        p = strchr(str, ':');
        if (p) str = p+1;
    }

    p = strrchr(str, '/');
    if (p) str = p+1;

    if (local) {
        p = strrchr(str, '\\');
        if (p) str = p+1;
    }

    return str;
}

/*
 * Determine whether a string is entirely composed of dots.
 */
static int is_dots(char *str)
{
    return str[strspn(str, ".")] == '\0';
}

/*
 *  Wait for a response from the other side.
 *  Return 0 if ok, -1 if error.
 */
static int response(void)
{
    char ch, resp, rbuf[2048];
    int p;

    if (ssh_scp_recv(&resp, 1) <= 0)
        bump("Lost connection");

    p = 0;
    switch (resp) {
      case 0:                          /* ok */
        return (0);
      default:
        rbuf[p++] = resp;
        /* fallthrough */
      case 1:                          /* error */
      case 2:                          /* fatal error */
        do {
            if (ssh_scp_recv(&ch, 1) <= 0)
                bump("Protocol error: Lost connection");
            rbuf[p++] = ch;
        } while (p < sizeof(rbuf) && ch != '\n');
        rbuf[p - 1] = '\0';
        if (resp == 1)
            tell_user(stderr, "%s\n", rbuf);
        else
            bump("%s", rbuf);
        errs++;
        return (-1);
    }
}

int sftp_recvdata(char *buf, int len)
{
    return ssh_scp_recv(buf, len);
}
int sftp_senddata(char *buf, int len)
{
    back->send((unsigned char *) buf, len);
    return 1;
}

/* ----------------------------------------------------------------------
 * sftp-based replacement for the hacky `pscp -ls'.
 */
static int sftp_ls_compare(const void *av, const void *bv)
{
    const struct fxp_name *a = (const struct fxp_name *) av;
    const struct fxp_name *b = (const struct fxp_name *) bv;
    return strcmp(a->filename, b->filename);
}
void scp_sftp_listdir(char *dirname)
{
    struct fxp_handle *dirh;
    struct fxp_names *names;
    struct fxp_name *ournames;
    int nnames, namesize;
    int i;

    printf("Listing directory %s\n", dirname);

    dirh = fxp_opendir(dirname);
    if (dirh == NULL) {
        printf("Unable to open %s: %s\n", dirname, fxp_error());
    } else {
        nnames = namesize = 0;
        ournames = NULL;

        while (1) {

            names = fxp_readdir(dirh);
            if (names == NULL) {
                if (fxp_error_type() == SSH_FX_EOF)
                    break;
                printf("Reading directory %s: %s\n", dirname, fxp_error());
                break;
            }
            if (names->nnames == 0) {
                fxp_free_names(names);
                break;
            }

            if (nnames + names->nnames >= namesize) {
                namesize += names->nnames + 128;
                ournames =
                    srealloc(ournames, namesize * sizeof(*ournames));
            }

            for (i = 0; i < names->nnames; i++)
                ournames[nnames++] = names->names[i];

            names->nnames = 0;         /* prevent free_names */
            fxp_free_names(names);
        }
        fxp_close(dirh);

        /*
         * Now we have our filenames. Sort them by actual file
         * name, and then output the longname parts.
         */
        qsort(ournames, nnames, sizeof(*ournames), sftp_ls_compare);

        /*
         * And print them.
         */
        for (i = 0; i < nnames; i++)
            printf("%s\n", ournames[i].longname);
    }
}

/* ----------------------------------------------------------------------
 * Helper routines that contain the actual SCP protocol elements,
 * implemented both as SCP1 and SFTP.
 */

static struct scp_sftp_dirstack {
    struct scp_sftp_dirstack *next;
    struct fxp_name *names;
    int namepos, namelen;
    char *dirpath;
    char *wildcard;
    int matched_something;             /* wildcard match set was non-empty */
} *scp_sftp_dirstack_head;
static char *scp_sftp_remotepath, *scp_sftp_currentname;
static char *scp_sftp_wildcard;
static int scp_sftp_targetisdir, scp_sftp_donethistarget;
static int scp_sftp_preserve, scp_sftp_recursive;
static unsigned long scp_sftp_mtime, scp_sftp_atime;
static int scp_has_times;
static struct fxp_handle *scp_sftp_filehandle;
static uint64 scp_sftp_fileoffset;

void scp_source_setup(char *target, int shouldbedir)
{
    if (using_sftp) {
        /*
         * Find out whether the target filespec is in fact a
         * directory.
         */
        struct fxp_attrs attrs;

        if (!fxp_stat(target, &attrs) ||
            !(attrs.flags & SSH_FILEXFER_ATTR_PERMISSIONS))
            scp_sftp_targetisdir = 0;
        else
            scp_sftp_targetisdir = (attrs.permissions & 0040000) != 0;

        if (shouldbedir && !scp_sftp_targetisdir) {
            bump("pscp: remote filespec %s: not a directory\n", target);
        }

        scp_sftp_remotepath = dupstr(target);

        scp_has_times = 0;
    } else {
        (void) response();
    }
}

int scp_send_errmsg(char *str)
{
    if (using_sftp) {
        /* do nothing; we never need to send our errors to the server */
    } else {
        back->send("\001", 1);         /* scp protocol error prefix */
        back->send(str, strlen(str));
    }
    return 0;                          /* can't fail */
}

int scp_send_filetimes(unsigned long mtime, unsigned long atime)
{
    if (using_sftp) {
        scp_sftp_mtime = mtime;
        scp_sftp_atime = atime;
        scp_has_times = 1;
        return 0;
    } else {
        char buf[80];
        sprintf(buf, "T%lu 0 %lu 0\n", mtime, atime);
        back->send(buf, strlen(buf));
        return response();
    }
}

int scp_send_filename(char *name, unsigned long size, int modes)
{
    if (using_sftp) {
        char *fullname;
        if (scp_sftp_targetisdir) {
            fullname = dupcat(scp_sftp_remotepath, "/", name, NULL);
        } else {
            fullname = dupstr(scp_sftp_remotepath);
        }
        scp_sftp_filehandle =
            fxp_open(fullname, SSH_FXF_WRITE | SSH_FXF_CREAT | SSH_FXF_TRUNC);
        if (!scp_sftp_filehandle) {
            tell_user(stderr, "pscp: unable to open %s: %s",
                      fullname, fxp_error());
            errs++;
            return 1;
        }
        scp_sftp_fileoffset = uint64_make(0, 0);
        sfree(fullname);
        return 0;
    } else {
        char buf[40];
        sprintf(buf, "C%04o %lu ", modes, size);
        back->send(buf, strlen(buf));
        back->send(name, strlen(name));
        back->send("\n", 1);
        return response();
    }
}

int scp_send_filedata(char *data, int len)
{
    if (using_sftp) {
        if (!scp_sftp_filehandle) {
            return 1;
        }
        if (!fxp_write(scp_sftp_filehandle, data, scp_sftp_fileoffset, len)) {
            tell_user(stderr, "error while writing: %s\n", fxp_error());
            errs++;
            return 1;
        }
        scp_sftp_fileoffset = uint64_add32(scp_sftp_fileoffset, len);
        return 0;
    } else {
        int bufsize = back->send(data, len);

        /*
         * If the network transfer is backing up - that is, the
         * remote site is not accepting data as fast as we can
         * produce it - then we must loop on network events until
         * we have space in the buffer again.
         */
        while (bufsize > MAX_SCP_BUFSIZE) {
            if (!scp_process_network_event())
                return 1;
            bufsize = back->sendbuffer();
        }

        return 0;
    }
}

int scp_send_finish(void)
{
    if (using_sftp) {
        struct fxp_attrs attrs;
        if (!scp_sftp_filehandle) {
            return 1;
        }
        if (scp_has_times) {
            attrs.flags = SSH_FILEXFER_ATTR_ACMODTIME;
            attrs.atime = scp_sftp_atime;
            attrs.mtime = scp_sftp_mtime;
            if (!fxp_fsetstat(scp_sftp_filehandle, attrs)) {
                tell_user(stderr, "unable to set file times: %s\n", fxp_error());
                errs++;
            }
        }
        fxp_close(scp_sftp_filehandle);
        scp_has_times = 0;
        return 0;
    } else {
        back->send("", 1);
        return response();
    }
}

char *scp_save_remotepath(void)
{
    if (using_sftp)
        return scp_sftp_remotepath;
    else
        return NULL;
}

void scp_restore_remotepath(char *data)
{
    if (using_sftp)
        scp_sftp_remotepath = data;
}

int scp_send_dirname(char *name, int modes)
{
    if (using_sftp) {
        char *fullname;
        char const *err;
        struct fxp_attrs attrs;
        if (scp_sftp_targetisdir) {
            fullname = dupcat(scp_sftp_remotepath, "/", name, NULL);
        } else {
            fullname = dupstr(scp_sftp_remotepath);
        }

        /*
         * We don't worry about whether we managed to create the
         * directory, because if it exists already it's OK just to
         * use it. Instead, we will stat it afterwards, and if it
         * exists and is a directory we will assume we were either
         * successful or it didn't matter.
         */
        if (!fxp_mkdir(fullname))
            err = fxp_error();
        else
            err = "server reported no error";
        if (!fxp_stat(fullname, &attrs) ||
            !(attrs.flags & SSH_FILEXFER_ATTR_PERMISSIONS) ||
            !(attrs.permissions & 0040000)) {
            tell_user(stderr, "unable to create directory %s: %s",
                      fullname, err);
            errs++;
            return 1;
        }

        scp_sftp_remotepath = fullname;

        return 0;
    } else {
        char buf[40];
        sprintf(buf, "D%04o 0 ", modes);
        back->send(buf, strlen(buf));
        back->send(name, strlen(name));
        back->send("\n", 1);
        return response();
    }
}

int scp_send_enddir(void)
{
    if (using_sftp) {
        sfree(scp_sftp_remotepath);
        return 0;
    } else {
        back->send("E\n", 2);
        return response();
    }
}

/*
 * Yes, I know; I have an scp_sink_setup _and_ an scp_sink_init.
 * That's bad. The difference is that scp_sink_setup is called once
 * right at the start, whereas scp_sink_init is called to
 * initialise every level of recursion in the protocol.
 */
int scp_sink_setup(char *source, int preserve, int recursive)
{
    if (using_sftp) {
        char *newsource;
        /*
         * It's possible that the source string we've been given
         * contains a wildcard. If so, we must split the directory
         * away from the wildcard itself (throwing an error if any
         * wildcardness comes before the final slash) and arrange
         * things so that a dirstack entry will be set up.
         */
        newsource = smalloc(1+strlen(source));
        if (!wc_unescape(newsource, source)) {
            /* Yes, here we go; it's a wildcard. Bah. */
            char *dupsource, *lastpart, *dirpart, *wildcard;
            dupsource = dupstr(source);
            lastpart = stripslashes(dupsource, 0);
            wildcard = dupstr(lastpart);
            *lastpart = '\0';
            if (*dupsource && dupsource[1]) {
                /*
                 * The remains of dupsource are at least two
                 * characters long, meaning the pathname wasn't
                 * empty or just `/'. Hence, we remove the trailing
                 * slash.
                 */
                lastpart[-1] = '\0';
            } else if (!*dupsource) {
                /*
                 * The remains of dupsource are _empty_ - the whole
                 * pathname was a wildcard. Hence we need to
                 * replace it with ".".
                 */
                sfree(dupsource);
                dupsource = dupstr(".");
            }

            /*
             * Now we have separated our string into dupsource (the
             * directory part) and wildcard. Both of these will
             * need freeing at some point. Next step is to remove
             * wildcard escapes from the directory part, throwing
             * an error if it contains a real wildcard.
             */
            dirpart = smalloc(1+strlen(dupsource));
            if (!wc_unescape(dirpart, dupsource)) {
                tell_user(stderr, "%s: multiple-level wildcards unsupported",
                          source);
                errs++;
                sfree(dirpart);
                sfree(wildcard);
                sfree(dupsource);
                return 1;
            }

            /*
             * Now we have dirpart (unescaped, ie a valid remote
             * path), and wildcard (a wildcard). This will be
             * sufficient to arrange a dirstack entry.
             */
            scp_sftp_remotepath = dirpart;
            scp_sftp_wildcard = wildcard;
            sfree(dupsource);
        } else {
            scp_sftp_remotepath = newsource;
            scp_sftp_wildcard = NULL;
        }
        scp_sftp_preserve = preserve;
        scp_sftp_recursive = recursive;
        scp_sftp_donethistarget = 0;
        scp_sftp_dirstack_head = NULL;
    }
    return 0;
}

int scp_sink_init(void)
{
    if (!using_sftp) {
        back->send("", 1);
    }
    return 0;
}

#define SCP_SINK_FILE   1
#define SCP_SINK_DIR    2
#define SCP_SINK_ENDDIR 3
#define SCP_SINK_RETRY  4              /* not an action; just try again */
struct scp_sink_action {
    int action;                        /* FILE, DIR, ENDDIR */
    char *buf;                         /* will need freeing after use */
    char *name;                        /* filename or dirname (not ENDDIR) */
    int mode;                          /* access mode (not ENDDIR) */
    unsigned long size;                /* file size (not ENDDIR) */
    int settime;                       /* 1 if atime and mtime are filled */
    unsigned long atime, mtime;        /* access times for the file */
};

int scp_get_sink_action(struct scp_sink_action *act)
{
    if (using_sftp) {
        char *fname;
        int must_free_fname;
        struct fxp_attrs attrs;
        int ret;

        if (!scp_sftp_dirstack_head) {
            if (!scp_sftp_donethistarget) {
                /*
                 * Simple case: we are only dealing with one file.
                 */
                fname = scp_sftp_remotepath;
                must_free_fname = 0;
                scp_sftp_donethistarget = 1;
            } else {
                /*
                 * Even simpler case: one file _which we've done_.
                 * Return 1 (finished).
                 */
                return 1;
            }
        } else {
            /*
             * We're now in the middle of stepping through a list
             * of names returned from fxp_readdir(); so let's carry
             * on.
             */
            struct scp_sftp_dirstack *head = scp_sftp_dirstack_head;
            while (head->namepos < head->namelen &&
                   (is_dots(head->names[head->namepos].filename) ||
                    (head->wildcard &&
                     !wc_match(head->wildcard,
                               head->names[head->namepos].filename))))
                head->namepos++;       /* skip . and .. */
            if (head->namepos < head->namelen) {
                head->matched_something = 1;
                fname = dupcat(head->dirpath, "/",
                               head->names[head->namepos++].filename,
                               NULL);
                must_free_fname = 1;
            } else {
                /*
                 * We've come to the end of the list; pop it off
                 * the stack and return an ENDDIR action (or RETRY
                 * if this was a wildcard match).
                 */
                if (head->wildcard) {
                    act->action = SCP_SINK_RETRY;
                    if (!head->matched_something) {
                        tell_user(stderr, "pscp: wildcard '%s' matched "
                                  "no files", head->wildcard);
                        errs++;
                    }
                    sfree(head->wildcard);

                } else {
                    act->action = SCP_SINK_ENDDIR;
                }

                sfree(head->dirpath);
                sfree(head->names);
                scp_sftp_dirstack_head = head->next;
                sfree(head);

                return 0;
            }
        }

        /*
         * Now we have a filename. Stat it, and see if it's a file
         * or a directory.
         */
        ret = fxp_stat(fname, &attrs);
        if (!ret || !(attrs.flags & SSH_FILEXFER_ATTR_PERMISSIONS)) {
            tell_user(stderr, "unable to identify %s: %s", fname,
                      ret ? "file type not supplied" : fxp_error());
            errs++;
            return 1;
        }

        if (attrs.permissions & 0040000) {
            struct scp_sftp_dirstack *newitem;
            struct fxp_handle *dirhandle;
            int nnames, namesize;
            struct fxp_name *ournames;
            struct fxp_names *names;

            /*
             * It's a directory. If we're not in recursive mode,
             * this merits a complaint (which is fatal if the name
             * was specified directly, but not if it was matched by
             * a wildcard).
             * 
             * We skip this complaint completely if
             * scp_sftp_wildcard is set, because that's an
             * indication that we're not actually supposed to
             * _recursively_ transfer the dir, just scan it for
             * things matching the wildcard.
             */
            if (!scp_sftp_recursive && !scp_sftp_wildcard) {
                tell_user(stderr, "pscp: %s: is a directory", fname);
                errs++;
                if (must_free_fname) sfree(fname);
                if (scp_sftp_dirstack_head) {
                    act->action = SCP_SINK_RETRY;
                    return 0;
                } else {
                    return 1;
                }
            }

            /*
             * Otherwise, the fun begins. We must fxp_opendir() the
             * directory, slurp the filenames into memory, return
             * SCP_SINK_DIR (unless this is a wildcard match), and
             * set targetisdir. The next time we're called, we will
             * run through the list of filenames one by one,
             * matching them against a wildcard if present.
             * 
             * If targetisdir is _already_ set (meaning we're
             * already in the middle of going through another such
             * list), we must push the other (target,namelist) pair
             * on a stack.
             */
            dirhandle = fxp_opendir(fname);
            if (!dirhandle) {
                tell_user(stderr, "scp: unable to open directory %s: %s",
                          fname, fxp_error());
                if (must_free_fname) sfree(fname);
                errs++;
                return 1;
            }
            nnames = namesize = 0;
            ournames = NULL;
            while (1) {
                int i;

                names = fxp_readdir(dirhandle);
                if (names == NULL) {
                    if (fxp_error_type() == SSH_FX_EOF)
                        break;
                    tell_user(stderr, "scp: reading directory %s: %s\n",
                              fname, fxp_error());
                    if (must_free_fname) sfree(fname);
                    sfree(ournames);
                    errs++;
                    return 1;
                }
                if (names->nnames == 0) {
                    fxp_free_names(names);
                    break;
                }
                if (nnames + names->nnames >= namesize) {
                    namesize += names->nnames + 128;
                    ournames =
                        srealloc(ournames, namesize * sizeof(*ournames));
                }
                for (i = 0; i < names->nnames; i++)
                    ournames[nnames++] = names->names[i];
                names->nnames = 0;             /* prevent free_names */
                fxp_free_names(names);
            }
            fxp_close(dirhandle);

            newitem = smalloc(sizeof(struct scp_sftp_dirstack));
            newitem->next = scp_sftp_dirstack_head;
            newitem->names = ournames;
            newitem->namepos = 0;
            newitem->namelen = nnames;
            if (must_free_fname)
                newitem->dirpath = fname;
            else
                newitem->dirpath = dupstr(fname);
            if (scp_sftp_wildcard) {
                newitem->wildcard = scp_sftp_wildcard;
                newitem->matched_something = 0;
                scp_sftp_wildcard = NULL;
            } else {
                newitem->wildcard = NULL;
            }
            scp_sftp_dirstack_head = newitem;

            if (newitem->wildcard) {
                act->action = SCP_SINK_RETRY;
            } else {
                act->action = SCP_SINK_DIR;
                act->buf = dupstr(stripslashes(fname, 0));
                act->name = act->buf;
                act->size = 0;         /* duhh, it's a directory */
                act->mode = 07777 & attrs.permissions;
                if (scp_sftp_preserve &&
                    (attrs.flags & SSH_FILEXFER_ATTR_ACMODTIME)) {
                    act->atime = attrs.atime;
                    act->mtime = attrs.mtime;
                    act->settime = 1;
                } else
                    act->settime = 0;
            }
            return 0;

        } else {
            /*
             * It's a file. Return SCP_SINK_FILE.
             */
            act->action = SCP_SINK_FILE;
            act->buf = dupstr(stripslashes(fname, 0));
            act->name = act->buf;
            if (attrs.flags & SSH_FILEXFER_ATTR_SIZE) {
                if (uint64_compare(attrs.size,
                                   uint64_make(0, ULONG_MAX)) > 0) {
                    act->size = ULONG_MAX;   /* *boggle* */
                } else
                    act->size = attrs.size.lo;
            } else
                act->size = ULONG_MAX;   /* no idea */
            act->mode = 07777 & attrs.permissions;
            if (scp_sftp_preserve &&
                (attrs.flags & SSH_FILEXFER_ATTR_ACMODTIME)) {
                act->atime = attrs.atime;
                act->mtime = attrs.mtime;
                act->settime = 1;
            } else
                act->settime = 0;
            if (must_free_fname)
                scp_sftp_currentname = fname;
            else
                scp_sftp_currentname = dupstr(fname);
            return 0;
        }

    } else {
        int done = 0;
        int i, bufsize;
        int action;
        char ch;

        act->settime = 0;
        act->buf = NULL;
        bufsize = 0;

        while (!done) {
            if (ssh_scp_recv(&ch, 1) <= 0)
                return 1;
            if (ch == '\n')
                bump("Protocol error: Unexpected newline");
            i = 0;
            action = ch;
            do {
                if (ssh_scp_recv(&ch, 1) <= 0)
                    bump("Lost connection");
                if (i >= bufsize) {
                    bufsize = i + 128;
                    act->buf = srealloc(act->buf, bufsize);
                }
                act->buf[i++] = ch;
            } while (ch != '\n');
            act->buf[i - 1] = '\0';
            switch (action) {
              case '\01':                      /* error */
                tell_user(stderr, "%s\n", act->buf);
                errs++;
                continue;                      /* go round again */
              case '\02':                      /* fatal error */
                bump("%s", act->buf);
              case 'E':
                back->send("", 1);
                act->action = SCP_SINK_ENDDIR;
                return 0;
              case 'T':
                if (sscanf(act->buf, "%ld %*d %ld %*d",
                           &act->mtime, &act->atime) == 2) {
                    act->settime = 1;
                    back->send("", 1);
                    continue;          /* go round again */
                }
                bump("Protocol error: Illegal time format");
              case 'C':
              case 'D':
                act->action = (action == 'C' ? SCP_SINK_FILE : SCP_SINK_DIR);
                break;
              default:
                bump("Protocol error: Expected control record");
            }
            /*
             * We will go round this loop only once, unless we hit
             * `continue' above.
             */
            done = 1;
        }

        /*
         * If we get here, we must have seen SCP_SINK_FILE or
         * SCP_SINK_DIR.
         */
        if (sscanf(act->buf, "%o %lu %n", &act->mode, &act->size, &i) != 2)
            bump("Protocol error: Illegal file descriptor format");
        act->name = act->buf + i;
        return 0;
    }
}

int scp_accept_filexfer(void)
{
    if (using_sftp) {
        scp_sftp_filehandle =
            fxp_open(scp_sftp_currentname, SSH_FXF_READ);
        if (!scp_sftp_filehandle) {
            tell_user(stderr, "pscp: unable to open %s: %s",
                      scp_sftp_currentname, fxp_error());
            errs++;
            return 1;
        }
        scp_sftp_fileoffset = uint64_make(0, 0);
        sfree(scp_sftp_currentname);
        return 0;
    } else {
        back->send("", 1);
        return 0;                      /* can't fail */
    }
}

int scp_recv_filedata(char *data, int len)
{
    if (using_sftp) {
        int actuallen = fxp_read(scp_sftp_filehandle, data,
                                 scp_sftp_fileoffset, len);
        if (actuallen == -1 && fxp_error_type() != SSH_FX_EOF) {
            tell_user(stderr, "pscp: error while reading: %s", fxp_error());
            errs++;
            return -1;
        }
        if (actuallen < 0)
            actuallen = 0;

        scp_sftp_fileoffset = uint64_add32(scp_sftp_fileoffset, actuallen);

        return actuallen;
    } else {
        return ssh_scp_recv(data, len);
    }
}

int scp_finish_filerecv(void)
{
    if (using_sftp) {
        fxp_close(scp_sftp_filehandle);
        return 0;
    } else {
        back->send("", 1);
        return response();
    }
}

/* ----------------------------------------------------------------------
 *  Send an error message to the other side and to the screen.
 *  Increment error counter.
 */
static void run_err(const char *fmt, ...)
{
    char str[2048];
    va_list ap;
    va_start(ap, fmt);
    errs++;
    strcpy(str, "scp: ");
    vsprintf(str + strlen(str), fmt, ap);
    strcat(str, "\n");
    scp_send_errmsg(str);
    tell_user(stderr, "%s", str);
    va_end(ap);
}

/*
 *  Execute the source part of the SCP protocol.
 */
static void source(char *src)
{
    unsigned long size;
    char *last;
    HANDLE f;
    DWORD attr;
    unsigned long i;
    unsigned long stat_bytes;
    time_t stat_starttime, stat_lasttime;

    attr = GetFileAttributes(src);
    if (attr == (DWORD) - 1) {
        run_err("%s: No such file or directory", src);
        return;
    }

    if ((attr & FILE_ATTRIBUTE_DIRECTORY) != 0) {
        if (recursive) {
            /*
             * Avoid . and .. directories.
             */
            char *p;
            p = strrchr(src, '/');
            if (!p)
                p = strrchr(src, '\\');
            if (!p)
                p = src;
            else
                p++;
            if (!strcmp(p, ".") || !strcmp(p, ".."))
                /* skip . and .. */ ;
            else
                rsource(src);
        } else {
            run_err("%s: not a regular file", src);
        }
        return;
    }

    if ((last = strrchr(src, '/')) == NULL)
        last = src;
    else
        last++;
    if (strrchr(last, '\\') != NULL)
        last = strrchr(last, '\\') + 1;
    if (last == src && strchr(src, ':') != NULL)
        last = strchr(src, ':') + 1;

    f = CreateFile(src, GENERIC_READ, FILE_SHARE_READ, NULL,
                   OPEN_EXISTING, 0, 0);
    if (f == INVALID_HANDLE_VALUE) {
        run_err("%s: Cannot open file", src);
        return;
    }

    if (preserve) {
        FILETIME actime, wrtime;
        unsigned long mtime, atime;
        GetFileTime(f, NULL, &actime, &wrtime);
        TIME_WIN_TO_POSIX(actime, atime);
        TIME_WIN_TO_POSIX(wrtime, mtime);
        if (scp_send_filetimes(mtime, atime))
            return;
    }

    size = GetFileSize(f, NULL);
    if (verbose)
        tell_user(stderr, "Sending file %s, size=%lu", last, size);
    if (scp_send_filename(last, size, 0644))
        return;

    stat_bytes = 0;
    stat_starttime = time(NULL);
    stat_lasttime = 0;

    for (i = 0; i < size; i += 4096) {
        char transbuf[4096];
        DWORD j, k = 4096;

        if (i + k > size)
            k = size - i;
        if (!ReadFile(f, transbuf, k, &j, NULL) || j != k) {
            if (statistics)
                printf("\n");
            bump("%s: Read error", src);
        }
        if (scp_send_filedata(transbuf, k))
            bump("%s: Network error occurred", src);

        if (statistics) {
            stat_bytes += k;
            if (time(NULL) != stat_lasttime || i + k == size) {
                stat_lasttime = time(NULL);
                print_stats(last, size, stat_bytes,
                            stat_starttime, stat_lasttime);
            }
        }

    }
    CloseHandle(f);

    (void) scp_send_finish();
}

/*
 *  Recursively send the contents of a directory.
 */
static void rsource(char *src)
{
    char *last, *findfile;
    char *save_target;
    HANDLE dir;
    WIN32_FIND_DATA fdat;
    int ok;

    if ((last = strrchr(src, '/')) == NULL)
        last = src;
    else
        last++;
    if (strrchr(last, '\\') != NULL)
        last = strrchr(last, '\\') + 1;
    if (last == src && strchr(src, ':') != NULL)
        last = strchr(src, ':') + 1;

    /* maybe send filetime */

    save_target = scp_save_remotepath();

    if (verbose)
        tell_user(stderr, "Entering directory: %s", last);
    if (scp_send_dirname(last, 0755))
        return;

    findfile = dupcat(src, "/*", NULL);
    dir = FindFirstFile(findfile, &fdat);
    ok = (dir != INVALID_HANDLE_VALUE);
    while (ok) {
        if (strcmp(fdat.cFileName, ".") == 0 ||
            strcmp(fdat.cFileName, "..") == 0) {
            /* ignore . and .. */
        } else {
            char *foundfile = dupcat(src, "/", fdat.cFileName, NULL);
            source(foundfile);
            sfree(foundfile);
        }
        ok = FindNextFile(dir, &fdat);
    }
    FindClose(dir);
    sfree(findfile);

    (void) scp_send_enddir();

    scp_restore_remotepath(save_target);
}

/*
 * Execute the sink part of the SCP protocol.
 */
static void sink(char *targ, char *src)
{
    char *destfname;
    int targisdir = 0;
    int exists;
    DWORD attr;
    HANDLE f;
    unsigned long received;
    int wrerror = 0;
    unsigned long stat_bytes;
    time_t stat_starttime, stat_lasttime;
    char *stat_name;

    attr = GetFileAttributes(targ);
    if (attr != (DWORD) - 1 && (attr & FILE_ATTRIBUTE_DIRECTORY) != 0)
        targisdir = 1;

    if (targetshouldbedirectory && !targisdir)
        bump("%s: Not a directory", targ);

    scp_sink_init();
    while (1) {
        struct scp_sink_action act;
        if (scp_get_sink_action(&act))
            return;

        if (act.action == SCP_SINK_ENDDIR)
            return;

        if (act.action == SCP_SINK_RETRY)
            continue;

        if (targisdir) {
            /*
             * Prevent the remote side from maliciously writing to
             * files outside the target area by sending a filename
             * containing `../'. In fact, it shouldn't be sending
             * filenames with any slashes or colons in at all; so
             * we'll find the last slash, backslash or colon in the
             * filename and use only the part after that. (And
             * warn!)
             * 
             * In addition, we also ensure here that if we're
             * copying a single file and the target is a directory
             * (common usage: `pscp host:filename .') the remote
             * can't send us a _different_ file name. We can
             * distinguish this case because `src' will be non-NULL
             * and the last component of that will fail to match
             * (the last component of) the name sent.
             * 
             * Well, not always; if `src' is a wildcard, we do
             * expect to get back filenames that don't correspond
             * exactly to it. Ideally in this case, we would like
             * to ensure that the returned filename actually
             * matches the wildcard pattern - but one of SCP's
             * protocol infelicities is that wildcard matching is
             * done at the server end _by the server's rules_ and
             * so in general this is infeasible. Hence, we only
             * accept filenames that don't correspond to `src' if
             * unsafe mode is enabled or we are using SFTP (which
             * resolves remote wildcards on the client side and can
             * be trusted).
             */
            char *striptarget, *stripsrc;

            striptarget = stripslashes(act.name, 1);
            if (striptarget != act.name) {
                tell_user(stderr, "warning: remote host sent a compound"
                          " pathname '%s'", act.name);
                tell_user(stderr, "         renaming local file to '%s'",
                          striptarget);
            }

            /*
             * Also check to see if the target filename is '.' or
             * '..', or indeed '...' and so on because Windows
             * appears to interpret those like '..'.
             */
            if (is_dots(striptarget)) {
                bump("security violation: remote host attempted to write to"
                     " a '.' or '..' path!");
            }

            if (src) {
                stripsrc = stripslashes(src, 1);
                if (strcmp(striptarget, stripsrc) &&
                    !using_sftp && !scp_unsafe_mode) {
                    tell_user(stderr, "warning: remote host tried to write "
                              "to a file called '%s'", striptarget);
                    tell_user(stderr, "         when we requested a file "
                              "called '%s'.", stripsrc);
                    tell_user(stderr, "         If this is a wildcard, "
                              "consider upgrading to SSH 2 or using");
                    tell_user(stderr, "         the '-unsafe' option. Renaming"
                              " of this file has been disallowed.");
                    /* Override the name the server provided with our own. */
                    striptarget = stripsrc;
                }
            }

            if (targ[0] != '\0')
                destfname = dupcat(targ, "\\", striptarget, NULL);
            else
                destfname = dupstr(striptarget);
        } else {
            /*
             * In this branch of the if, the target area is a
             * single file with an explicitly specified name in any
             * case, so there's no danger.
             */
            destfname = dupstr(targ);
        }
        attr = GetFileAttributes(destfname);
        exists = (attr != (DWORD) - 1);

        if (act.action == SCP_SINK_DIR) {
            if (exists && (attr & FILE_ATTRIBUTE_DIRECTORY) == 0) {
                run_err("%s: Not a directory", destfname);
                continue;
            }
            if (!exists) {
                if (!CreateDirectory(destfname, NULL)) {
                    run_err("%s: Cannot create directory", destfname);
                    continue;
                }
            }
            sink(destfname, NULL);
            /* can we set the timestamp for directories ? */
            continue;
        }

        f = CreateFile(destfname, GENERIC_WRITE, 0, NULL,
                       CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
        if (f == INVALID_HANDLE_VALUE) {
            run_err("%s: Cannot create file", destfname);
            continue;
        }

        if (scp_accept_filexfer())
            return;

        stat_bytes = 0;
        stat_starttime = time(NULL);
        stat_lasttime = 0;
        stat_name = stripslashes(destfname, 1);

        received = 0;
        while (received < act.size) {
            char transbuf[4096];
            DWORD blksize, read, written;
            blksize = 4096;
            if (blksize > act.size - received)
                blksize = act.size - received;
            read = scp_recv_filedata(transbuf, blksize);
            if (read <= 0)
                bump("Lost connection");
            if (wrerror)
                continue;
            if (!WriteFile(f, transbuf, read, &written, NULL) ||
                written != read) {
                wrerror = 1;
                /* FIXME: in sftp we can actually abort the transfer */
                if (statistics)
                    printf("\r%-25.25s | %50s\n",
                           stat_name,
                           "Write error.. waiting for end of file");
                continue;
            }
            if (statistics) {
                stat_bytes += read;
                if (time(NULL) > stat_lasttime ||
                    received + read == act.size) {
                    stat_lasttime = time(NULL);
                    print_stats(stat_name, act.size, stat_bytes,
                                stat_starttime, stat_lasttime);
                }
            }
            received += read;
        }
        if (act.settime) {
            FILETIME actime, wrtime;
            TIME_POSIX_TO_WIN(act.atime, actime);
            TIME_POSIX_TO_WIN(act.mtime, wrtime);
            SetFileTime(f, NULL, &actime, &wrtime);
        }

        CloseHandle(f);
        if (wrerror) {
            run_err("%s: Write error", destfname);
            continue;
        }
        (void) scp_finish_filerecv();
        sfree(destfname);
        sfree(act.buf);
    }
}

/*
 * We will copy local files to a remote server.
 */
static void toremote(int argc, char *argv[])
{
    char *src, *targ, *host, *user;
    char *cmd;
    int i;

    targ = argv[argc - 1];

    /* Separate host from filename */
    host = targ;
    targ = colon(targ);
    if (targ == NULL)
        bump("targ == NULL in toremote()");
    *targ++ = '\0';
    if (*targ == '\0')
        targ = ".";
    /* Substitute "." for emtpy target */

    /* Separate host and username */
    user = host;
    host = strrchr(host, '@');
    if (host == NULL) {
        host = user;
        user = NULL;
    } else {
        *host++ = '\0';
        if (*user == '\0')
            user = NULL;
    }

    if (argc == 2) {
        /* Find out if the source filespec covers multiple files
           if so, we should set the targetshouldbedirectory flag */
        HANDLE fh;
        WIN32_FIND_DATA fdat;
        if (colon(argv[0]) != NULL)
            bump("%s: Remote to remote not supported", argv[0]);
        fh = FindFirstFile(argv[0], &fdat);
        if (fh == INVALID_HANDLE_VALUE)
            bump("%s: No such file or directory\n", argv[0]);
        if (FindNextFile(fh, &fdat))
            targetshouldbedirectory = 1;
        FindClose(fh);
    }

    cmd = smalloc(strlen(targ) + 100);
    sprintf(cmd, "scp%s%s%s%s -t %s",
            verbose ? " -v" : "",
            recursive ? " -r" : "",
            preserve ? " -p" : "",
            targetshouldbedirectory ? " -d" : "", targ);
    do_cmd(host, user, cmd);
    sfree(cmd);

    scp_source_setup(targ, targetshouldbedirectory);

    for (i = 0; i < argc - 1; i++) {
        char *srcpath, *last;
        HANDLE dir;
        WIN32_FIND_DATA fdat;
        src = argv[i];
        if (colon(src) != NULL) {
            tell_user(stderr, "%s: Remote to remote not supported\n", src);
            errs++;
            continue;
        }

        /*
         * Trim off the last pathname component of `src', to
         * provide the base pathname which will be prepended to
         * filenames returned from Find{First,Next}File.
         */
        srcpath = dupstr(src);
        last = stripslashes(srcpath, 1);
        *last = '\0';

        dir = FindFirstFile(src, &fdat);
        if (dir == INVALID_HANDLE_VALUE) {
            run_err("%s: No such file or directory", src);
            continue;
        }
        do {
            char *filename;
            /*
             * Ensure that . and .. are never matched by wildcards,
             * but only by deliberate action.
             */
            if (!strcmp(fdat.cFileName, ".") ||
                !strcmp(fdat.cFileName, "..")) {
                /*
                 * Find*File has returned a special dir. We require
                 * that _either_ `src' ends in a backslash followed
                 * by that string, _or_ `src' is precisely that
                 * string.
                 */
                int len = strlen(src), dlen = strlen(fdat.cFileName);
                if (len == dlen && !strcmp(src, fdat.cFileName)) {
                    /* ok */ ;
                } else if (len > dlen + 1 && src[len - dlen - 1] == '\\' &&
                           !strcmp(src + len - dlen, fdat.cFileName)) {
                    /* ok */ ;
                } else
                    continue;          /* ignore this one */
            }
            filename = dupcat(srcpath, fdat.cFileName, NULL);
            source(filename);
            sfree(filename);
        } while (FindNextFile(dir, &fdat));
        FindClose(dir);
        sfree(srcpath);
    }
}

/*
 *  We will copy files from a remote server to the local machine.
 */
static void tolocal(int argc, char *argv[])
{
    char *src, *targ, *host, *user;
    char *cmd;

    if (argc != 2)
        bump("More than one remote source not supported");

    src = argv[0];
    targ = argv[1];

    /* Separate host from filename */
    host = src;
    src = colon(src);
    if (src == NULL)
        bump("Local to local copy not supported");
    *src++ = '\0';
    if (*src == '\0')
        src = ".";
    /* Substitute "." for empty filename */

    /* Separate username and hostname */
    user = host;
    host = strrchr(host, '@');
    if (host == NULL) {
        host = user;
        user = NULL;
    } else {
        *host++ = '\0';
        if (*user == '\0')
            user = NULL;
    }

    cmd = smalloc(strlen(src) + 100);
    sprintf(cmd, "scp%s%s%s%s -f %s",
            verbose ? " -v" : "",
            recursive ? " -r" : "",
            preserve ? " -p" : "",
            targetshouldbedirectory ? " -d" : "", src);
    do_cmd(host, user, cmd);
    sfree(cmd);

    if (scp_sink_setup(src, preserve, recursive))
        return;

    sink(targ, src);
}

/*
 *  We will issue a list command to get a remote directory.
 */
static void get_dir_list(int argc, char *argv[])
{
    char *src, *host, *user;
    char *cmd, *p, *q;
    char c;

    src = argv[0];

    /* Separate host from filename */
    host = src;
    src = colon(src);
    if (src == NULL)
        bump("Local to local copy not supported");
    *src++ = '\0';
    if (*src == '\0')
        src = ".";
    /* Substitute "." for empty filename */

    /* Separate username and hostname */
    user = host;
    host = strrchr(host, '@');
    if (host == NULL) {
        host = user;
        user = NULL;
    } else {
        *host++ = '\0';
        if (*user == '\0')
            user = NULL;
    }

    cmd = smalloc(4 * strlen(src) + 100);
    strcpy(cmd, "ls -la '");
    p = cmd + strlen(cmd);
    for (q = src; *q; q++) {
        if (*q == '\'') {
            *p++ = '\'';
            *p++ = '\\';
            *p++ = '\'';
            *p++ = '\'';
        } else {
            *p++ = *q;
        }
    }
    *p++ = '\'';
    *p = '\0';

    do_cmd(host, user, cmd);
    sfree(cmd);

    if (using_sftp) {
        scp_sftp_listdir(src);
    } else {
        while (ssh_scp_recv(&c, 1) > 0)
            tell_char(stdout, c);
    }
}

/*
 *  Initialize the Win$ock driver.
 */
static void init_winsock(void)
{
    WORD winsock_ver;
    WSADATA wsadata;

    winsock_ver = MAKEWORD(1, 1);
    if (WSAStartup(winsock_ver, &wsadata))
        bump("Unable to initialise WinSock");
    if (LOBYTE(wsadata.wVersion) != 1 || HIBYTE(wsadata.wVersion) != 1)
        bump("WinSock version is incompatible with 1.1");
}

/*
 *  Short description of parameters.
 */
static void usage(void)
{
    printf("PuTTY Secure Copy client\n");
    printf("%s\n", ver);
    printf("Usage: pscp [options] [user@]host:source target\n");
    printf
        ("       pscp [options] source [source...] [user@]host:target\n");
    printf("       pscp [options] -ls user@host:filespec\n");
    printf("Options:\n");
    printf("  -p        preserve file attributes\n");
    printf("  -q        quiet, don't show statistics\n");
    printf("  -r        copy directories recursively\n");
    printf("  -v        show verbose messages\n");
    printf("  -P port   connect to specified port\n");
    printf("  -pw passw login with specified password\n");
    printf("  -unsafe   allow server-side wildcards (DANGEROUS)\n");
#if 0
    /*
     * -gui is an internal option, used by GUI front ends to get
     * pscp to pass progress reports back to them. It's not an
     * ordinary user-accessible option, so it shouldn't be part of
     * the command-line help. The only people who need to know
     * about it are programmers, and they can read the source.
     */
    printf
        ("  -gui hWnd GUI mode with the windows handle for receiving messages\n");
#endif
    exit(1);
}

/*
 *  Main program (no, really?)
 */
int main(int argc, char *argv[])
{
    int i;

    default_protocol = PROT_TELNET;

    flags = FLAG_STDERR;
    ssh_get_line = &get_line;
    init_winsock();
    sk_init();

    for (i = 1; i < argc; i++) {
        if (argv[i][0] != '-')
            break;
        if (strcmp(argv[i], "-v") == 0)
            verbose = 1, flags |= FLAG_VERBOSE;
        else if (strcmp(argv[i], "-r") == 0)
            recursive = 1;
        else if (strcmp(argv[i], "-p") == 0)
            preserve = 1;
        else if (strcmp(argv[i], "-q") == 0)
            statistics = 0;
        else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "-?") == 0)
            usage();
        else if (strcmp(argv[i], "-P") == 0 && i + 1 < argc)
            portnumber = atoi(argv[++i]);
        else if (strcmp(argv[i], "-pw") == 0 && i + 1 < argc)
            password = argv[++i];
        else if (strcmp(argv[i], "-gui") == 0 && i + 1 < argc) {
            gui_hwnd = argv[++i];
            gui_mode = 1;
        } else if (strcmp(argv[i], "-ls") == 0)
            list = 1;
        else if (strcmp(argv[i], "-unsafe") == 0)
            scp_unsafe_mode = 1;
        else if (strcmp(argv[i], "--") == 0) {
            i++;
            break;
        } else
            usage();
    }
    argc -= i;
    argv += i;
    back = NULL;

    if (list) {
        if (argc != 1)
            usage();
        get_dir_list(argc, argv);

    } else {

        if (argc < 2)
            usage();
        if (argc > 2)
            targetshouldbedirectory = 1;

        if (colon(argv[argc - 1]) != NULL)
            toremote(argc, argv);
        else
            tolocal(argc, argv);
    }

    if (back != NULL && back->socket() != NULL) {
        char ch;
        back->special(TS_EOF);
        ssh_scp_recv(&ch, 1);
    }
    WSACleanup();
    random_save_seed();

    /* GUI Adaptation - August 2000 */
    if (gui_mode) {
        unsigned int msg_id = WM_RET_ERR_CNT;
        if (list)
            msg_id = WM_LS_RET_ERR_CNT;
        while (!PostMessage
               ((HWND) atoi(gui_hwnd), msg_id, (WPARAM) errs,
                0 /*lParam */ ))SleepEx(1000, TRUE);
    }
    return (errs == 0 ? 0 : 1);
}

/* end */