Function ipcomp_output_cb

freebsd/netipsec/xform_ipcomp.c:524–660

* IPComp output callback from the crypto driver. */

 * IPComp output callback from the crypto driver.
 */
static int
ipcomp_output_cb(struct cryptop *crp)
{
	IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
	struct xform_data *xd;
	struct secpolicy *sp;
	struct secasvar *sav;
	struct mbuf *m;
	crypto_session_t cryptoid;
	u_int idx;
	int error, skip, protoff;

	m = crp->crp_buf.cb_mbuf;
	xd = crp->crp_opaque;
	CURVNET_SET(xd->vnet);
	idx = xd->idx;
	sp = xd->sp;
	sav = xd->sav;
	skip = xd->skip;
	protoff = xd->protoff;
	cryptoid = xd->cryptoid;

	/* Check for crypto errors */
	if (crp->crp_etype) {
		if (crp->crp_etype == EAGAIN) {
			/* Reset the session ID */
			if (ipsec_updateid(sav, &crp->crp_session, &cryptoid) != 0)
				crypto_freesession(cryptoid);
			xd->cryptoid = crp->crp_session;
			CURVNET_RESTORE();
			return (crypto_dispatch(crp));
		}
		IPCOMPSTAT_INC(ipcomps_noxform);
		DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
		error = crp->crp_etype;
		goto bad;
	}
	/* Shouldn't happen... */
	if (m == NULL) {
		IPCOMPSTAT_INC(ipcomps_crypto);
		DPRINTF(("%s: bogus return buffer from crypto\n", __func__));
		error = EINVAL;
		goto bad;
	}
	IPCOMPSTAT_INC(ipcomps_hist[sav->alg_comp]);

	if (crp->crp_payload_length > crp->crp_olen) {
		struct mbuf *mo;
		struct ipcomp *ipcomp;
		int roff;
		uint8_t prot;

		/* Compression helped, inject IPCOMP header. */
		mo = m_makespace(m, skip, IPCOMP_HLENGTH, &roff);
		if (mo == NULL) {
			IPCOMPSTAT_INC(ipcomps_wrap);
			DPRINTF(("%s: IPCOMP header inject failed "
			    "for IPCA %s/%08lx\n",