Function key_acquire

freebsd/netipsec/key.c:6541–6762

* SADB_ACQUIRE processing called by key_checkrequest() and key_acquire2(). * send * * to KMD, and expect to receive * with SADB_ACQUIRE if error occurred, * or * with SADB_GETSPI * from KMD by PF_KEY. * * XXX x_policy is outside of RF

 *    others: error number
 */
static int
key_acquire(const struct secasindex *saidx, struct secpolicy *sp)
{
	union sockaddr_union addr;
	struct mbuf *result, *m;
	uint32_t seq;
	int error;
	uint16_t ul_proto;
	uint8_t mask, satype;

	IPSEC_ASSERT(saidx != NULL, ("null saidx"));
	satype = key_proto2satype(saidx->proto);
	IPSEC_ASSERT(satype != 0, ("null satype, protocol %u", saidx->proto));

	error = -1;
	result = NULL;
	ul_proto = IPSEC_ULPROTO_ANY;

	/* Get seq number to check whether sending message or not. */
	seq = key_getacq(saidx, &error);
	if (seq == 0)
		return (error);

	m = key_setsadbmsg(SADB_ACQUIRE, 0, satype, seq, 0, 0);
	if (!m) {
		error = ENOBUFS;
		goto fail;
	}
	result = m;

	/*
	 * set sadb_address for saidx's.
	 *
	 * Note that if sp is supplied, then we're being called from
	 * key_allocsa_policy() and should supply port and protocol
	 * information.
	 * XXXAE: why only TCP and UDP? ICMP and SCTP looks applicable too.
	 * XXXAE: probably we can handle this in the ipsec[46]_allocsa().
	 * XXXAE: it looks like we should save this info in the ACQ entry.
	 */
	if (sp != NULL && (sp->spidx.ul_proto == IPPROTO_TCP ||
	    sp->spidx.ul_proto == IPPROTO_UDP))
		ul_proto = sp->spidx.ul_proto;

	addr = saidx->src;
	mask = FULLMASK;
	if (ul_proto != IPSEC_ULPROTO_ANY) {
		switch (sp->spidx.src.sa.sa_family) {
		case AF_INET:
			if (sp->spidx.src.sin.sin_port != IPSEC_PORT_ANY) {
				addr.sin.sin_port = sp->spidx.src.sin.sin_port;
				mask = sp->spidx.prefs;
			}
			break;
		case AF_INET6:
			if (sp->spidx.src.sin6.sin6_port != IPSEC_PORT_ANY) {
				addr.sin6.sin6_port =
				    sp->spidx.src.sin6.sin6_port;