add: if (server_version < 3) return -EPERM;
context: static int sshfs_symlink(const char *from, const char *to){    int err;    struct buffer buf;    /* openssh sftp server doesn't follow standard: link target and       link name are mixed up, so we must also be non-standard :( */    buf_init(&buf, 0);    buf_add_string(&buf, from);    buf_add_path(&buf, to);    err = sftp_request(SSH_FXP_SYMLINK, &buf, SSH_FXP_STATUS, NULL);    buf_free(&buf);    return err;}