Function tcp_ipsec_output

freebsd/netipsec/xform_tcp.c:297–315

* Compute TCP-MD5 hash of an *OUTBOUND* TCP segment. * Parameters: * m pointer to head of mbuf chain * th pointer to TCP header * buf pointer to storage for computed MD5 digest * * Return 0 if successful, otherwise return error code. */

 * Return 0 if successful, otherwise return error code.
 */
static int
tcp_ipsec_output(struct mbuf *m, struct tcphdr *th, u_char *buf)
{
	struct secasindex saidx;
	struct secasvar *sav;

	setsockaddrs(m, &saidx.src, &saidx.dst);
	saidx.proto = IPPROTO_TCP;
	saidx.mode = IPSEC_MODE_TCPMD5;
	saidx.reqid = 0;
	sav = key_allocsa_tcpmd5(&saidx);
	if (sav == NULL) {
		KMOD_TCPSTAT_INC(tcps_sig_err_buildsig);
		return (EACCES);
	}
	tcp_signature_compute(m, th, sav, buf);
	key_freesav(&sav);
	return (0);
}

/*
 * Initialize a TCP-MD5 SA. Called when the SA is being set up.