5.1.3 SMTPD_CMD smtpd_cmd_table[]数组：回调函数数组

static SMTPD_CMD smtpd_cmd_table[] = {
{SMTPD_CMD_HELO, helo_cmd, SMTPD_CMD_FLAG_LIMIT | SMTPD_CMD_FLAG_PRE_TLS| SMTPD_CMD_FLAG_LAST,},
{SMTPD_CMD_EHLO, ehlo_cmd, SMTPD_CMD_FLAG_LIMIT | SMTPD_CMD_FLAG_PRE_TLS| SMTPD_CMD_FLAG_LAST,},
{SMTPD_CMD_XCLIENT, xclient_cmd,},
{SMTPD_CMD_XFORWARD, xforward_cmd,},
#ifdef USE_TLS
{SMTPD_CMD_STARTTLS, starttls_cmd, SMTPD_CMD_FLAG_PRE_TLS,},
#else
{SMTPD_CMD_STARTTLS, unimpl_cmd, SMTPD_CMD_FLAG_PRE_TLS,},
#endif
#ifdef USE_SASL_AUTH
{SMTPD_CMD_AUTH, smtpd_sasl_auth_cmd,},
#else
{SMTPD_CMD_AUTH, unimpl_cmd,},
#endif
{SMTPD_CMD_MAIL, mail_cmd,},
{SMTPD_CMD_RCPT, rcpt_cmd,},
{SMTPD_CMD_DATA, data_cmd, SMTPD_CMD_FLAG_LAST,},
{SMTPD_CMD_RSET, rset_cmd, SMTPD_CMD_FLAG_LIMIT,},
{SMTPD_CMD_NOOP, noop_cmd, SMTPD_CMD_FLAG_LIMIT | SMTPD_CMD_FLAG_PRE_TLS| SMTPD_CMD_FLAG_LAST,},
{SMTPD_CMD_VRFY, vrfy_cmd, SMTPD_CMD_FLAG_LIMIT | SMTPD_CMD_FLAG_LAST,},
{SMTPD_CMD_ETRN, etrn_cmd, SMTPD_CMD_FLAG_LIMIT,},
{SMTPD_CMD_QUIT, quit_cmd, SMTPD_CMD_FLAG_PRE_TLS,},
{0,},
};