Function ah_input_cb

freebsd/netipsec/xform_ah.c:684–828

* AH input callback from the crypto driver. */

 * AH input callback from the crypto driver.
 */
static int
ah_input_cb(struct cryptop *crp)
{
	IPSEC_DEBUG_DECLARE(char buf[IPSEC_ADDRSTRLEN]);
	unsigned char calc[AH_ALEN_MAX];
	struct mbuf *m;
	struct xform_data *xd;
	struct secasvar *sav;
	struct secasindex *saidx;
	caddr_t ptr;
	crypto_session_t cryptoid;
	int authsize, rplen, ahsize, error, skip, protoff;
	uint8_t nxt;

	m = crp->crp_buf.cb_mbuf;
	xd = crp->crp_opaque;
	CURVNET_SET(xd->vnet);
	sav = xd->sav;
	skip = xd->skip;
	nxt = xd->nxt;
	protoff = xd->protoff;
	cryptoid = xd->cryptoid;
	saidx = &sav->sah->saidx;
	IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET ||
		saidx->dst.sa.sa_family == AF_INET6,
		("unexpected protocol family %u", saidx->dst.sa.sa_family));

	/* 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));
		}
		AHSTAT_INC(ahs_noxform);
		DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype));
		error = crp->crp_etype;
		goto bad;
	} else {
		AHSTAT_INC(ahs_hist[sav->alg_auth]);
		crypto_freereq(crp);		/* No longer needed. */
		crp = NULL;
	}

	/* Shouldn't happen... */
	if (m == NULL) {
		AHSTAT_INC(ahs_crypto);
		DPRINTF(("%s: bogus returned buffer from crypto\n", __func__));
		error = EINVAL;
		goto bad;
	}

	/* Figure out header size. */
	rplen = HDRSIZE(sav);
	authsize = AUTHSIZE(sav);