Revamp SSH authentication code so that user interaction is more

[u/mdw/putty] / unix / uxsftp.c

/*
 * uxsftp.c: the Unix-specific parts of PSFTP and PSCP.
 */

#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <fcntl.h>
#include <dirent.h>
#include <unistd.h>
#include <utime.h>
#include <errno.h>
#include <assert.h>
#include <glob.h>
#ifndef HAVE_NO_SYS_SELECT_H
#include <sys/select.h>
#endif

#include "putty.h"
#include "psftp.h"

/*
 * In PSFTP our selects are synchronous, so these functions are
 * empty stubs.
 */
int uxsel_input_add(int fd, int rwx) { return 0; }
void uxsel_input_remove(int id) { }

char *x_get_default(const char *key)
{
    return NULL;                       /* this is a stub */
}

void platform_get_x11_auth(char *display, int *protocol,
                           unsigned char *data, int *datalen)
{
    /* Do nothing, therefore no auth. */
}

/*
 * Default settings that are specific to PSFTP.
 */
char *platform_default_s(const char *name)
{
    return NULL;
}

int platform_default_i(const char *name, int def)
{
    return def;
}

FontSpec platform_default_fontspec(const char *name)
{
    FontSpec ret;
    *ret.name = '\0';
    return ret;
}

Filename platform_default_filename(const char *name)
{
    Filename ret;
    if (!strcmp(name, "LogFileName"))
        strcpy(ret.path, "putty.log");
    else
        *ret.path = '\0';
    return ret;
}

char *get_ttymode(void *frontend, const char *mode) { return NULL; }

int get_userpass_input(prompts_t *p, unsigned char *in, int inlen)
{
    int ret;
    ret = cmdline_get_passwd_input(p, in, inlen);
    if (ret == -1)
        ret = console_get_userpass_input(p, in, inlen);
    return ret;
}

/*
 * Stubs for the GUI feedback mechanism in Windows PSCP.
 */
void gui_update_stats(char *name, unsigned long size,
                      int percentage, unsigned long elapsed,
                      unsigned long done, unsigned long eta,
                      unsigned long ratebs) {}
void gui_send_errcount(int list, int errs) {}
void gui_send_char(int is_stderr, int c) {}
void gui_enable(char *arg) {}


/*
 * Set local current directory. Returns NULL on success, or else an
 * error message which must be freed after printing.
 */
char *psftp_lcd(char *dir)
{
    if (chdir(dir) < 0)
        return dupprintf("%s: chdir: %s", dir, strerror(errno));
    else
        return NULL;
}

/*
 * Get local current directory. Returns a string which must be
 * freed.
 */
char *psftp_getcwd(void)
{
    char *buffer, *ret;
    int size = 256;

    buffer = snewn(size, char);
    while (1) {
        ret = getcwd(buffer, size);
        if (ret != NULL)
            return ret;
        if (errno != ERANGE) {
            sfree(buffer);
            return dupprintf("[cwd unavailable: %s]", strerror(errno));
        }
        /*
         * Otherwise, ERANGE was returned, meaning the buffer
         * wasn't big enough.
         */
        size = size * 3 / 2;
        buffer = sresize(buffer, size, char);
    }
}

struct RFile {
    int fd;
};

RFile *open_existing_file(char *name, unsigned long *size,
                          unsigned long *mtime, unsigned long *atime)
{
    int fd;
    RFile *ret;

    fd = open(name, O_RDONLY);
    if (fd < 0)
        return NULL;

    ret = snew(RFile);
    ret->fd = fd;

    if (size || mtime || atime) {
        struct stat statbuf;
        if (fstat(fd, &statbuf) < 0) {
            fprintf(stderr, "%s: stat: %s\n", name, strerror(errno));
            memset(&statbuf, 0, sizeof(statbuf));
        }

        if (size)
            *size = statbuf.st_size;

        if (mtime)
            *mtime = statbuf.st_mtime;

        if (atime)
            *atime = statbuf.st_atime;
    }

    return ret;
}

int read_from_file(RFile *f, void *buffer, int length)
{
    return read(f->fd, buffer, length);
}

void close_rfile(RFile *f)
{
    close(f->fd);
    sfree(f);
}

struct WFile {
    int fd;
    char *name;
};

WFile *open_new_file(char *name)
{
    int fd;
    WFile *ret;

    fd = open(name, O_CREAT | O_TRUNC | O_WRONLY, 0666);
    if (fd < 0)
        return NULL;

    ret = snew(WFile);
    ret->fd = fd;
    ret->name = dupstr(name);

    return ret;
}

int write_to_file(WFile *f, void *buffer, int length)
{
    char *p = (char *)buffer;
    int so_far = 0;

    /* Keep trying until we've really written as much as we can. */
    while (length > 0) {
        int ret = write(f->fd, p, length);

        if (ret < 0)
            return ret;

        if (ret == 0)
            break;

        p += ret;
        length -= ret;
        so_far += ret;
    }

    return so_far;
}

void set_file_times(WFile *f, unsigned long mtime, unsigned long atime)
{
    struct utimbuf ut;

    ut.actime = atime;
    ut.modtime = mtime;

    utime(f->name, &ut);
}

/* Closes and frees the WFile */
void close_wfile(WFile *f)
{
    close(f->fd);
    sfree(f->name);
    sfree(f);
}

int file_type(char *name)
{
    struct stat statbuf;

    if (stat(name, &statbuf) < 0) {
        if (errno != ENOENT)
            fprintf(stderr, "%s: stat: %s\n", name, strerror(errno));
        return FILE_TYPE_NONEXISTENT;
    }

    if (S_ISREG(statbuf.st_mode))
        return FILE_TYPE_FILE;

    if (S_ISDIR(statbuf.st_mode))
        return FILE_TYPE_DIRECTORY;

    return FILE_TYPE_WEIRD;
}

struct DirHandle {
    DIR *dir;
};

DirHandle *open_directory(char *name)
{
    DIR *dir;
    DirHandle *ret;

    dir = opendir(name);
    if (!dir)
        return NULL;

    ret = snew(DirHandle);
    ret->dir = dir;
    return ret;
}

char *read_filename(DirHandle *dir)
{
    struct dirent *de;

    do {
        de = readdir(dir->dir);
        if (de == NULL)
            return NULL;
    } while ((de->d_name[0] == '.' &&
              (de->d_name[1] == '\0' ||
               (de->d_name[1] == '.' && de->d_name[2] == '\0'))));

    return dupstr(de->d_name);
}

void close_directory(DirHandle *dir)
{
    closedir(dir->dir);
    sfree(dir);
}

int test_wildcard(char *name, int cmdline)
{
    struct stat statbuf;

    if (stat(name, &statbuf) == 0) {
        return WCTYPE_FILENAME;
    } else if (cmdline) {
        /*
         * On Unix, we never need to parse wildcards coming from
         * the command line, because the shell will have expanded
         * them into a filename list already.
         */
        return WCTYPE_NONEXISTENT;
    } else {
        glob_t globbed;
        int ret = WCTYPE_NONEXISTENT;

        if (glob(name, GLOB_ERR, NULL, &globbed) == 0) {
            if (globbed.gl_pathc > 0)
                ret = WCTYPE_WILDCARD;
            globfree(&globbed);
        }

        return ret;
    }
}

/*
 * Actually return matching file names for a local wildcard.
 */
struct WildcardMatcher {
    glob_t globbed;
    int i;
};
WildcardMatcher *begin_wildcard_matching(char *name) {
    WildcardMatcher *ret = snew(WildcardMatcher);

    if (glob(name, 0, NULL, &ret->globbed) < 0) {
        sfree(ret);
        return NULL;
    }

    ret->i = 0;

    return ret;
}
char *wildcard_get_filename(WildcardMatcher *dir) {
    if (dir->i < dir->globbed.gl_pathc) {
        return dupstr(dir->globbed.gl_pathv[dir->i++]);
    } else
        return NULL;
}
void finish_wildcard_matching(WildcardMatcher *dir) {
    globfree(&dir->globbed);
    sfree(dir);
}

int vet_filename(char *name)
{
    if (strchr(name, '/'))
        return FALSE;

    if (name[0] == '.' && (!name[1] || (name[1] == '.' && !name[2])))
        return FALSE;

    return TRUE;
}

int create_directory(char *name)
{
    return mkdir(name, 0777) == 0;
}

char *dir_file_cat(char *dir, char *file)
{
    return dupcat(dir, "/", file, NULL);
}

/*
 * Do a select() between all currently active network fds and
 * optionally stdin.
 */
static int ssh_sftp_do_select(int include_stdin, int no_fds_ok)
{
    fd_set rset, wset, xset;
    int i, fdcount, fdsize, *fdlist;
    int fd, fdstate, rwx, ret, maxfd;
    long now = GETTICKCOUNT();

    fdlist = NULL;
    fdcount = fdsize = 0;

    do {

        /* Count the currently active fds. */
        i = 0;
        for (fd = first_fd(&fdstate, &rwx); fd >= 0;
             fd = next_fd(&fdstate, &rwx)) i++;

        if (i < 1 && !no_fds_ok)
            return -1;                 /* doom */

        /* Expand the fdlist buffer if necessary. */
        if (i > fdsize) {
            fdsize = i + 16;
            fdlist = sresize(fdlist, fdsize, int);
        }

        FD_ZERO(&rset);
        FD_ZERO(&wset);
        FD_ZERO(&xset);
        maxfd = 0;

        /*
         * Add all currently open fds to the select sets, and store
         * them in fdlist as well.
         */
        fdcount = 0;
        for (fd = first_fd(&fdstate, &rwx); fd >= 0;
             fd = next_fd(&fdstate, &rwx)) {
            fdlist[fdcount++] = fd;
            if (rwx & 1)
                FD_SET_MAX(fd, maxfd, rset);
            if (rwx & 2)
                FD_SET_MAX(fd, maxfd, wset);
            if (rwx & 4)
                FD_SET_MAX(fd, maxfd, xset);
        }

        if (include_stdin)
            FD_SET_MAX(0, maxfd, rset);

        do {
            long next, ticks;
            struct timeval tv, *ptv;

            if (run_timers(now, &next)) {
                ticks = next - GETTICKCOUNT();
                if (ticks <= 0)
                    ticks = 1;         /* just in case */
                tv.tv_sec = ticks / 1000;
                tv.tv_usec = ticks % 1000 * 1000;
                ptv = &tv;
            } else {
                ptv = NULL;
            }
            ret = select(maxfd, &rset, &wset, &xset, ptv);
            if (ret == 0)
                now = next;
            else {
                long newnow = GETTICKCOUNT();
                /*
                 * Check to see whether the system clock has
                 * changed massively during the select.
                 */
                if (newnow - now < 0 || newnow - now > next - now) {
                    /*
                     * If so, look at the elapsed time in the
                     * select and use it to compute a new
                     * tickcount_offset.
                     */
                    long othernow = now + tv.tv_sec * 1000 + tv.tv_usec / 1000;
                    /* So we'd like GETTICKCOUNT to have returned othernow,
                     * but instead it return newnow. Hence ... */
                    tickcount_offset += othernow - newnow;
                    now = othernow;
                } else {
                    now = newnow;
                }
            }
        } while (ret < 0 && errno != EINTR);
    } while (ret == 0);

    if (ret < 0) {
        perror("select");
        exit(1);
    }

    for (i = 0; i < fdcount; i++) {
        fd = fdlist[i];
        /*
         * We must process exceptional notifications before
         * ordinary readability ones, or we may go straight
         * past the urgent marker.
         */
        if (FD_ISSET(fd, &xset))
            select_result(fd, 4);
        if (FD_ISSET(fd, &rset))
            select_result(fd, 1);
        if (FD_ISSET(fd, &wset))
            select_result(fd, 2);
    }

    sfree(fdlist);

    return FD_ISSET(0, &rset) ? 1 : 0;
}

/*
 * Wait for some network data and process it.
 */
int ssh_sftp_loop_iteration(void)
{
    return ssh_sftp_do_select(FALSE, FALSE);
}

/*
 * Read a PSFTP command line from stdin.
 */
char *ssh_sftp_get_cmdline(char *prompt, int no_fds_ok)
{
    char *buf;
    int buflen, bufsize, ret;

    fputs(prompt, stdout);
    fflush(stdout);

    buf = NULL;
    buflen = bufsize = 0;

    while (1) {
        ret = ssh_sftp_do_select(TRUE, no_fds_ok);
        if (ret < 0) {
            printf("connection died\n");
            return NULL;               /* woop woop */
        }
        if (ret > 0) {
            if (buflen >= bufsize) {
                bufsize = buflen + 512;
                buf = sresize(buf, bufsize, char);
            }
            ret = read(0, buf+buflen, 1);
            if (ret < 0) {
                perror("read");
                return NULL;
            }
            if (ret == 0) {
                /* eof on stdin; no error, but no answer either */
                return NULL;
            }

            if (buf[buflen++] == '\n') {
                /* we have a full line */
                return buf;
            }
        }
    }
}

/*
 * Main program: do platform-specific initialisation and then call
 * psftp_main().
 */
int main(int argc, char *argv[])
{
    uxsel_init();
    return psftp_main(argc, argv);
}