ssh.c

    if (conn->data->state.used_interface == Curl_if_multi) {
      result = Curl_ssh_multi_statemach(conn, &done);
    } else {
      result = ssh_easy_statemach(conn);
      done = TRUE;
    }
  } else {
    result = status;
    done = TRUE;
  }

  if (done) {
    Curl_safefree(conn->data->reqdata.proto.ssh);
    conn->data->reqdata.proto.ssh = NULL;
    Curl_pgrsDone(conn);
  }

  return result;

}

/* return number of received (decrypted) bytes */
ssize_t Curl_scp_send(struct connectdata *conn, int sockindex,
                      void *mem, size_t len)
{
  ssize_t nwrite;

  /* libssh2_channel_write() returns int
   *
   * NOTE: we should not store nor rely on connection-related data to be
   * in the SessionHandle struct
   */
  nwrite = (ssize_t)
    libssh2_channel_write(conn->data->reqdata.proto.ssh->ssh_channel,
                          mem, len);
  if (nwrite == LIBSSH2_ERROR_EAGAIN)
    return 0;
  (void)sockindex;
  return nwrite;
}

/*
 * If the read would block (EWOULDBLOCK) we return -1. Otherwise we return
 * a regular CURLcode value.
 */
ssize_t Curl_scp_recv(struct connectdata *conn, int sockindex,
                      char *mem, size_t len)
{
  ssize_t nread;
  (void)sockindex; /* we only support SCP on the fixed known primary socket */

  /* libssh2_channel_read() returns int
   *
   * NOTE: we should not store nor rely on connection-related data to be
   * in the SessionHandle struct
   */
  nread = (ssize_t)
    libssh2_channel_read(conn->data->reqdata.proto.ssh->ssh_channel,
                         mem, len);
  return nread;
}

/*
 * =============== SFTP ===============
 */

/*
 ***********************************************************************
 *
 * sftp_perform()
 *
 * This is the actual DO function for SFTP. Get a file/directory according to
 * the options previously setup.
 */

static
CURLcode sftp_perform(struct connectdata *conn,
                      bool *connected,
                      bool *dophase_done)
{
  CURLcode result = CURLE_OK;

  DEBUGF(infof(conn->data, "DO phase starts\n"));

  *dophase_done = FALSE; /* not done yet */

  /* start the first command in the DO phase */
  state(conn, SSH_SFTP_QUOTE_INIT);

  /* run the state-machine */
  if (conn->data->state.used_interface == Curl_if_multi) {
    result = Curl_ssh_multi_statemach(conn, dophase_done);
  } else {
    result = ssh_easy_statemach(conn);
    *dophase_done = TRUE; /* with the easy interface we are done here */
  }
  *connected = conn->bits.tcpconnect;

  if (*dophase_done) {
    DEBUGF(infof(conn->data, "DO phase is complete\n"));
  }

  return result;
}

/* called from multi.c while DOing */
static CURLcode Curl_sftp_doing(struct connectdata *conn,
                                bool *dophase_done)
{
  CURLcode result;
  result = Curl_ssh_multi_statemach(conn, dophase_done);

  if (*dophase_done) {
    DEBUGF(infof(conn->data, "DO phase is complete\n"));
  }
  return result;
}

static CURLcode Curl_sftp_do(struct connectdata *conn, bool *done)
{
  CURLcode res;
  bool connected = 0;
  struct SessionHandle *data = conn->data;

  *done = FALSE; /* default to false */

  /*
   * Since connections can be re-used between SessionHandles, this might be a
   * connection already existing but on a fresh SessionHandle struct so we must
   * make sure we have a good 'struct SSHPROTO' to play with. For new
   * connections, the struct SSHPROTO is allocated and setup in the
   * Curl_ssh_connect() function.
   */
  res = ssh_init(conn);
  if (res) {
    return res;
  }

  data->reqdata.size = -1; /* make sure this is unknown at this point */

  Curl_pgrsSetUploadCounter(data, 0);
  Curl_pgrsSetDownloadCounter(data, 0);
  Curl_pgrsSetUploadSize(data, 0);
  Curl_pgrsSetDownloadSize(data, 0);

  res = sftp_perform(conn, &connected,  done);

  if (CURLE_OK == res) {

    if (!done) {
      /* the DO phase has not completed yet */
      return CURLE_OK;
    }
  }

  return res;
}

static CURLcode Curl_sftp_done(struct connectdata *conn, CURLcode status,
                               bool premature)
{
  CURLcode result = CURLE_OK;
  bool done = FALSE;
  struct ssh_conn *sshc = &conn->proto.sshc;

  (void)status; /* unused */

  if (status == CURLE_OK) {
    /* Before we shut down, see if there are any post-quote commands to send: */
    if (!status && !premature && conn->data->set.postquote) {
      sshc->nextState = SSH_SFTP_CLOSE;
      state(conn, SSH_SFTP_POSTQUOTE_INIT);
    } else {
      state(conn, SSH_SFTP_CLOSE);
    }

    /* run the state-machine */
    if (conn->data->state.used_interface == Curl_if_multi) {
      result = Curl_ssh_multi_statemach(conn, &done);
    } else {
      result = ssh_easy_statemach(conn);
      done = TRUE;
    }
  } else {
    result = status;
    done = TRUE;
  }

  if (done) {
    Curl_safefree(conn->data->reqdata.proto.ssh);
    conn->data->reqdata.proto.ssh = NULL;
    Curl_pgrsDone(conn);
  }

  return result;
}

/* return number of received (decrypted) bytes */
ssize_t Curl_sftp_send(struct connectdata *conn, int sockindex,
                       void *mem, size_t len)
{
  ssize_t nwrite;   /* libssh2_sftp_write() used to return size_t in 0.14
                       but is changed to ssize_t in 0.15! */

  nwrite = (ssize_t)
    libssh2_sftp_write(conn->data->reqdata.proto.ssh->sftp_handle, mem, len);
  if (nwrite == LIBSSH2_ERROR_EAGAIN)
    return 0;

  (void)sockindex;
  return nwrite;
}

/*
 * If the read would block (EWOULDBLOCK) we return -1. Otherwise we return
 * a regular CURLcode value.
 */
ssize_t Curl_sftp_recv(struct connectdata *conn, int sockindex,
                       char *mem, size_t len)
{
  ssize_t nread;
  (void)sockindex;

  /* libssh2_sftp_read() returns size_t !*/
  nread = (ssize_t)
    libssh2_sftp_read(conn->data->reqdata.proto.ssh->sftp_handle, mem, len);

  return nread;
}

/* The get_pathname() function is being borrowed from OpenSSH sftp.c
   version 4.6p1. */
/*
 * Copyright (c) 2001-2004 Damien Miller <djm@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
static int
get_pathname(const char **cpp, char **path)
{
  const char *cp = *cpp, *end;
  char quot;
  u_int i, j;
  static const char * const WHITESPACE = " \t\r\n";

  cp += strspn(cp, WHITESPACE);
  if (!*cp) {
    *cpp = cp;
    *path = NULL;
    return CURLE_QUOTE_ERROR;
  }

  *path = malloc(strlen(cp) + 1);
  if (*path == NULL)
    return CURLE_OUT_OF_MEMORY;

  /* Check for quoted filenames */
  if (*cp == '\"' || *cp == '\'') {
    quot = *cp++;

    /* Search for terminating quote, unescape some chars */
    for (i = j = 0; i <= strlen(cp); i++) {
      if (cp[i] == quot) {  /* Found quote */
        i++;
        (*path)[j] = '\0';
        break;
      }
      if (cp[i] == '\0') {  /* End of string */
        /*error("Unterminated quote");*/
        goto fail;
      }
      if (cp[i] == '\\') {  /* Escaped characters */
        i++;
        if (cp[i] != '\'' && cp[i] != '\"' &&
            cp[i] != '\\') {
          /*error("Bad escaped character '\\%c'",
              cp[i]);*/
          goto fail;
        }
      }
      (*path)[j++] = cp[i];
    }

    if (j == 0) {
      /*error("Empty quotes");*/
      goto fail;
    }
    *cpp = cp + i + strspn(cp + i, WHITESPACE);
  }
  else {
    /* Read to end of filename */
    end = strpbrk(cp, WHITESPACE);
    if (end == NULL)
      end = strchr(cp, '\0');
    *cpp = end + strspn(end, WHITESPACE);

    memcpy(*path, cp, end - cp);
    (*path)[end - cp] = '\0';
  }
  return (0);

  fail:
    Curl_safefree(*path);
    *path = NULL;
    return CURLE_QUOTE_ERROR;
}


static const char *sftp_libssh2_strerror(unsigned long err)
{
  switch (err) {
    case LIBSSH2_FX_NO_SUCH_FILE:
      return "No such file or directory";

    case LIBSSH2_FX_PERMISSION_DENIED:
      return "Permission denied";

    case LIBSSH2_FX_FAILURE:
      return "Operation failed";

    case LIBSSH2_FX_BAD_MESSAGE:
      return "Bad message from SFTP server";

    case LIBSSH2_FX_NO_CONNECTION:
      return "Not connected to SFTP server";

    case LIBSSH2_FX_CONNECTION_LOST:
      return "Connection to SFTP server lost";

    case LIBSSH2_FX_OP_UNSUPPORTED:
      return "Operation not supported by SFTP server";

    case LIBSSH2_FX_INVALID_HANDLE:
      return "Invalid handle";

    case LIBSSH2_FX_NO_SUCH_PATH:
      return "No such file or directory";

    case LIBSSH2_FX_FILE_ALREADY_EXISTS:
      return "File already exists";

    case LIBSSH2_FX_WRITE_PROTECT:
      return "File is write protected";

    case LIBSSH2_FX_NO_MEDIA:
      return "No media";

    case LIBSSH2_FX_NO_SPACE_ON_FILESYSTEM:
      return "Disk full";

    case LIBSSH2_FX_QUOTA_EXCEEDED:
      return "User quota exceeded";

    case LIBSSH2_FX_UNKNOWN_PRINCIPLE:
      return "Unknown principle";

    case LIBSSH2_FX_LOCK_CONFlICT:
      return "File lock conflict";

    case LIBSSH2_FX_DIR_NOT_EMPTY:
      return "Directory not empty";

    case LIBSSH2_FX_NOT_A_DIRECTORY:
      return "Not a directory";

    case LIBSSH2_FX_INVALID_FILENAME:
      return "Invalid filename";

    case LIBSSH2_FX_LINK_LOOP:
      return "Link points to itself";
  }
  return "Unknown error in libssh2";
}

#endif /* USE_LIBSSH2 */