cxgbe/tom/t4_listen.c

/*-
 * Copyright (c) 2012 Chelsio Communications, Inc.
 * All rights reserved.
 * Written by: Navdeep Parhar <np@FreeBSD.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: stable/11/sys/dev/cxgbe/tom/t4_listen.c 331722 2018-03-29 02:50:57Z eadler $");

#include "opt_inet.h"
#include "opt_inet6.h"

#ifdef TCP_OFFLOAD
#include <sys/param.h>
#include <sys/types.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/module.h>
#include <sys/protosw.h>
#include <sys/refcount.h>
#include <sys/domain.h>
#include <sys/fnv_hash.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_vlan_var.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_fib.h>
#include <netinet/in_pcb.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet6/in6_fib.h>
#include <netinet6/scope6_var.h>
#include <netinet/tcp_timer.h>
#define TCPSTATES
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_var.h>
#include <netinet/toecore.h>

#include "common/common.h"
#include "common/t4_msg.h"
#include "common/t4_regs.h"
#include "tom/t4_tom_l2t.h"
#include "tom/t4_tom.h"

/* stid services */
static int alloc_stid(struct adapter *, struct listen_ctx *, int);
static struct listen_ctx *lookup_stid(struct adapter *, int);
static void free_stid(struct adapter *, struct listen_ctx *);

/* lctx services */
static struct listen_ctx *alloc_lctx(struct adapter *, struct inpcb *,
    struct vi_info *);
static int free_lctx(struct adapter *, struct listen_ctx *);
static void hold_lctx(struct listen_ctx *);
static void listen_hash_add(struct adapter *, struct listen_ctx *);
static struct listen_ctx *listen_hash_find(struct adapter *, struct inpcb *);
static struct listen_ctx *listen_hash_del(struct adapter *, struct inpcb *);
static struct inpcb *release_lctx(struct adapter *, struct listen_ctx *);

static inline void save_qids_in_mbuf(struct mbuf *, struct vi_info *);
static inline void get_qids_from_mbuf(struct mbuf *m, int *, int *);
static void send_reset_synqe(struct toedev *, struct synq_entry *);

static int
alloc_stid(struct adapter *sc, struct listen_ctx *lctx, int isipv6)
{
	struct tid_info *t = &sc->tids;
	u_int stid, n, f, mask;
	struct stid_region *sr = &lctx->stid_region;

	/*
	 * An IPv6 server needs 2 naturally aligned stids (1 stid = 4 cells) in
	 * the TCAM.  The start of the stid region is properly aligned (the chip
	 * requires each region to be 128-cell aligned).
	 */
	n = isipv6 ? 2 : 1;
	mask = n - 1;
	KASSERT((t->stid_base & mask) == 0 && (t->nstids & mask) == 0,
	    ("%s: stid region (%u, %u) not properly aligned.  n = %u",
	    __func__, t->stid_base, t->nstids, n));

	mtx_lock(&t->stid_lock);
	if (n > t->nstids - t->stids_in_use) {
		mtx_unlock(&t->stid_lock);
		return (-1);
	}

	if (t->nstids_free_head >= n) {
		/*
		 * This allocation will definitely succeed because the region
		 * starts at a good alignment and we just checked we have enough
		 * stids free.
		 */
		f = t->nstids_free_head & mask;
		t->nstids_free_head -= n + f;
		stid = t->nstids_free_head;
		TAILQ_INSERT_HEAD(&t->stids, sr, link);
	} else {
		struct stid_region *s;

		stid = t->nstids_free_head;
		TAILQ_FOREACH(s, &t->stids, link) {
			stid += s->used + s->free;
			f = stid & mask;
			if (s->free >= n + f) {
				stid -= n + f;
				s->free -= n + f;
				TAILQ_INSERT_AFTER(&t->stids, s, sr, link);
				goto allocated;
			}
		}

		if (__predict_false(stid != t->nstids)) {
			panic("%s: stids TAILQ (%p) corrupt."
			    "  At %d instead of %d at the end of the queue.",
			    __func__, &t->stids, stid, t->nstids);
		}

		mtx_unlock(&t->stid_lock);
		return (-1);
	}

allocated:
	sr->used = n;
	sr->free = f;
	t->stids_in_use += n;
	t->stid_tab[stid] = lctx;
	mtx_unlock(&t->stid_lock);

	KASSERT(((stid + t->stid_base) & mask) == 0,
	    ("%s: EDOOFUS.", __func__));
	return (stid + t->stid_base);
}

static struct listen_ctx *
lookup_stid(struct adapter *sc, int stid)
{
	struct tid_info *t = &sc->tids;

	return (t->stid_tab[stid - t->stid_base]);
}

static void
free_stid(struct adapter *sc, struct listen_ctx *lctx)
{
	struct tid_info *t = &sc->tids;
	struct stid_region *sr = &lctx->stid_region;
	struct stid_region *s;

	KASSERT(sr->used > 0, ("%s: nonsense free (%d)", __func__, sr->used));

	mtx_lock(&t->stid_lock);
	s = TAILQ_PREV(sr, stid_head, link);
	if (s != NULL)
		s->free += sr->used + sr->free;
	else
		t->nstids_free_head += sr->used + sr->free;
	KASSERT(t->stids_in_use >= sr->used,
	    ("%s: stids_in_use (%u) < stids being freed (%u)", __func__,
	    t->stids_in_use, sr->used));
	t->stids_in_use -= sr->used;
	TAILQ_REMOVE(&t->stids, sr, link);
	mtx_unlock(&t->stid_lock);
}

static struct listen_ctx *
alloc_lctx(struct adapter *sc, struct inpcb *inp, struct vi_info *vi)
{
	struct listen_ctx *lctx;

	INP_WLOCK_ASSERT(inp);

	lctx = malloc(sizeof(struct listen_ctx), M_CXGBE, M_NOWAIT | M_ZERO);
	if (lctx == NULL)
		return (NULL);

	lctx->stid = alloc_stid(sc, lctx, inp->inp_vflag & INP_IPV6);
	if (lctx->stid < 0) {
		free(lctx, M_CXGBE);
		return (NULL);
	}

	if (inp->inp_vflag & INP_IPV6 &&
	    !IN6_ARE_ADDR_EQUAL(&in6addr_any, &inp->in6p_laddr)) {
		struct tom_data *td = sc->tom_softc;

		lctx->ce = hold_lip(td, &inp->in6p_laddr, NULL);
		if (lctx->ce == NULL) {
			free(lctx, M_CXGBE);
			return (NULL);
		}
	}

	lctx->ctrlq = &sc->sge.ctrlq[vi->pi->port_id];
	lctx->ofld_rxq = &sc->sge.ofld_rxq[vi->first_ofld_rxq];
	refcount_init(&lctx->refcount, 1);
	TAILQ_INIT(&lctx->synq);

	lctx->inp = inp;
	lctx->vnet = inp->inp_socket->so_vnet;
	in_pcbref(inp);

	return (lctx);
}

/* Don't call this directly, use release_lctx instead */
static int
free_lctx(struct adapter *sc, struct listen_ctx *lctx)
{
	struct inpcb *inp = lctx->inp;
	struct tom_data *td = sc->tom_softc;

	INP_WLOCK_ASSERT(inp);
	KASSERT(lctx->refcount == 0,
	    ("%s: refcount %d", __func__, lctx->refcount));
	KASSERT(TAILQ_EMPTY(&lctx->synq),
	    ("%s: synq not empty.", __func__));
	KASSERT(lctx->stid >= 0, ("%s: bad stid %d.", __func__, lctx->stid));

	CTR4(KTR_CXGBE, "%s: stid %u, lctx %p, inp %p",
	    __func__, lctx->stid, lctx, lctx->inp);

	if (lctx->ce)
		release_lip(td, lctx->ce);
	free_stid(sc, lctx);
	free(lctx, M_CXGBE);

	return (in_pcbrele_wlocked(inp));
}

static void
hold_lctx(struct listen_ctx *lctx)
{

	refcount_acquire(&lctx->refcount);
}

static inline uint32_t
listen_hashfn(void *key, u_long mask)
{

	return (fnv_32_buf(&key, sizeof(key), FNV1_32_INIT) & mask);
}

/*
 * Add a listen_ctx entry to the listen hash table.
 */
static void
listen_hash_add(struct adapter *sc, struct listen_ctx *lctx)
{
	struct tom_data *td = sc->tom_softc;
	int bucket = listen_hashfn(lctx->inp, td->listen_mask);

	mtx_lock(&td->lctx_hash_lock);
	LIST_INSERT_HEAD(&td->listen_hash[bucket], lctx, link);
	td->lctx_count++;
	mtx_unlock(&td->lctx_hash_lock);
}

/*
 * Look for the listening socket's context entry in the hash and return it.
 */
static struct listen_ctx *
listen_hash_find(struct adapter *sc, struct inpcb *inp)
{
	struct tom_data *td = sc->tom_softc;
	int bucket = listen_hashfn(inp, td->listen_mask);
	struct listen_ctx *lctx;

	mtx_lock(&td->lctx_hash_lock);
	LIST_FOREACH(lctx, &td->listen_hash[bucket], link) {
		if (lctx->inp == inp)
			break;
	}
	mtx_unlock(&td->lctx_hash_lock);

	return (lctx);
}

/*
 * Removes the listen_ctx structure for inp from the hash and returns it.
 */
static struct listen_ctx *
listen_hash_del(struct adapter *sc, struct inpcb *inp)
{
	struct tom_data *td = sc->tom_softc;
	int bucket = listen_hashfn(inp, td->listen_mask);
	struct listen_ctx *lctx, *l;

	mtx_lock(&td->lctx_hash_lock);
	LIST_FOREACH_SAFE(lctx, &td->listen_hash[bucket], link, l) {
		if (lctx->inp == inp) {
			LIST_REMOVE(lctx, link);
			td->lctx_count--;
			break;
		}
	}
	mtx_unlock(&td->lctx_hash_lock);

	return (lctx);
}

/*
 * Releases a hold on the lctx.  Must be called with the listening socket's inp
 * locked.  The inp may be freed by this function and it returns NULL to
 * indicate this.
 */
static struct inpcb *
release_lctx(struct adapter *sc, struct listen_ctx *lctx)
{
	struct inpcb *inp = lctx->inp;
	int inp_freed = 0;

	INP_WLOCK_ASSERT(inp);
	if (refcount_release(&lctx->refcount))
		inp_freed = free_lctx(sc, lctx);

	return (inp_freed ? NULL : inp);
}

static void
send_reset_synqe(struct toedev *tod, struct synq_entry *synqe)
{
	struct adapter *sc = tod->tod_softc;
	struct mbuf *m = synqe->syn;
	struct ifnet *ifp = m->m_pkthdr.rcvif;
	struct vi_info *vi = ifp->if_softc;
	struct port_info *pi = vi->pi;
	struct l2t_entry *e = &sc->l2t->l2tab[synqe->l2e_idx];
	struct wrqe *wr;
	struct fw_flowc_wr *flowc;
	struct cpl_abort_req *req;
	int txqid, rxqid, flowclen;
	struct sge_wrq *ofld_txq;
	struct sge_ofld_rxq *ofld_rxq;
	const int nparams = 6;
	unsigned int pfvf = G_FW_VIID_PFN(vi->viid) << S_FW_VIID_PFN;

	INP_WLOCK_ASSERT(synqe->lctx->inp);

	CTR5(KTR_CXGBE, "%s: synqe %p (0x%x), tid %d%s",
	    __func__, synqe, synqe->flags, synqe->tid,
	    synqe->flags & TPF_ABORT_SHUTDOWN ?
	    " (abort already in progress)" : "");
	if (synqe->flags & TPF_ABORT_SHUTDOWN)
		return;	/* abort already in progress */
	synqe->flags |= TPF_ABORT_SHUTDOWN;

	get_qids_from_mbuf(m, &txqid, &rxqid);
	ofld_txq = &sc->sge.ofld_txq[txqid];
	ofld_rxq = &sc->sge.ofld_rxq[rxqid];

	/* The wrqe will have two WRs - a flowc followed by an abort_req */
	flowclen = sizeof(*flowc) + nparams * sizeof(struct fw_flowc_mnemval);

	wr = alloc_wrqe(roundup2(flowclen, EQ_ESIZE) + sizeof(*req), ofld_txq);
	if (wr == NULL) {
		/* XXX */
		panic("%s: allocation failure.", __func__);
	}
	flowc = wrtod(wr);
	req = (void *)((caddr_t)flowc + roundup2(flowclen, EQ_ESIZE));

	/* First the flowc ... */
	memset(flowc, 0, wr->wr_len);
	flowc->op_to_nparams = htobe32(V_FW_WR_OP(FW_FLOWC_WR) |
	    V_FW_FLOWC_WR_NPARAMS(nparams));
	flowc->flowid_len16 = htonl(V_FW_WR_LEN16(howmany(flowclen, 16)) |
	    V_FW_WR_FLOWID(synqe->tid));
	flowc->mnemval[0].mnemonic = FW_FLOWC_MNEM_PFNVFN;
	flowc->mnemval[0].val = htobe32(pfvf);
	flowc->mnemval[1].mnemonic = FW_FLOWC_MNEM_CH;
	flowc->mnemval[1].val = htobe32(pi->tx_chan);
	flowc->mnemval[2].mnemonic = FW_FLOWC_MNEM_PORT;
	flowc->mnemval[2].val = htobe32(pi->tx_chan);
	flowc->mnemval[3].mnemonic = FW_FLOWC_MNEM_IQID;
	flowc->mnemval[3].val = htobe32(ofld_rxq->iq.abs_id);
 	flowc->mnemval[4].mnemonic = FW_FLOWC_MNEM_SNDBUF;
 	flowc->mnemval[4].val = htobe32(512);
 	flowc->mnemval[5].mnemonic = FW_FLOWC_MNEM_MSS;
 	flowc->mnemval[5].val = htobe32(512);
	synqe->flags |= TPF_FLOWC_WR_SENT;

	/* ... then ABORT request */
	INIT_TP_WR_MIT_CPL(req, CPL_ABORT_REQ, synqe->tid);
	req->rsvd0 = 0;	/* don't have a snd_nxt */
	req->rsvd1 = 1;	/* no data sent yet */
	req->cmd = CPL_ABORT_SEND_RST;

	t4_l2t_send(sc, wr, e);
}

static int
create_server(struct adapter *sc, struct listen_ctx *lctx)
{
	struct wrqe *wr;
	struct cpl_pass_open_req *req;
	struct inpcb *inp = lctx->inp;

	wr = alloc_wrqe(sizeof(*req), lctx->ctrlq);
	if (wr == NULL) {
		log(LOG_ERR, "%s: allocation failure", __func__);
		return (ENOMEM);
	}
	req = wrtod(wr);

	INIT_TP_WR(req, 0);
	OPCODE_TID(req) = htobe32(MK_OPCODE_TID(CPL_PASS_OPEN_REQ, lctx->stid));
	req->local_port = inp->inp_lport;
	req->peer_port = 0;
	req->local_ip = inp->inp_laddr.s_addr;
	req->peer_ip = 0;
	req->opt0 = htobe64(V_TX_CHAN(lctx->ctrlq->eq.tx_chan));
	req->opt1 = htobe64(V_CONN_POLICY(CPL_CONN_POLICY_ASK) |
	    F_SYN_RSS_ENABLE | V_SYN_RSS_QUEUE(lctx->ofld_rxq->iq.abs_id));

	t4_wrq_tx(sc, wr);
	return (0);
}

static int
create_server6(struct adapter *sc, struct listen_ctx *lctx)
{
	struct wrqe *wr;
	struct cpl_pass_open_req6 *req;
	struct inpcb *inp = lctx->inp;

	wr = alloc_wrqe(sizeof(*req), lctx->ctrlq);
	if (wr == NULL) {
		log(LOG_ERR, "%s: allocation failure", __func__);
		return (ENOMEM);
	}
	req = wrtod(wr);

	INIT_TP_WR(req, 0);
	OPCODE_TID(req) = htobe32(MK_OPCODE_TID(CPL_PASS_OPEN_REQ6, lctx->stid));
	req->local_port = inp->inp_lport;
	req->peer_port = 0;
	req->local_ip_hi = *(uint64_t *)&inp->in6p_laddr.s6_addr[0];
	req->local_ip_lo = *(uint64_t *)&inp->in6p_laddr.s6_addr[8];
	req->peer_ip_hi = 0;
	req->peer_ip_lo = 0;
	req->opt0 = htobe64(V_TX_CHAN(lctx->ctrlq->eq.tx_chan));
	req->opt1 = htobe64(V_CONN_POLICY(CPL_CONN_POLICY_ASK) |
	    F_SYN_RSS_ENABLE | V_SYN_RSS_QUEUE(lctx->ofld_rxq->iq.abs_id));

	t4_wrq_tx(sc, wr);
	return (0);
}

static int
destroy_server(struct adapter *sc, struct listen_ctx *lctx)
{
	struct wrqe *wr;
	struct cpl_close_listsvr_req *req;

	wr = alloc_wrqe(sizeof(*req), lctx->ctrlq);
	if (wr == NULL) {
		/* XXX */
		panic("%s: allocation failure.", __func__);
	}
	req = wrtod(wr);

	INIT_TP_WR(req, 0);
	OPCODE_TID(req) = htonl(MK_OPCODE_TID(CPL_CLOSE_LISTSRV_REQ,
	    lctx->stid));
	req->reply_ctrl = htobe16(lctx->ofld_rxq->iq.abs_id);
	req->rsvd = htobe16(0);

	t4_wrq_tx(sc, wr);
	return (0);
}

/*
 * Start a listening server by sending a passive open request to HW.
 *
 * Can't take adapter lock here and access to sc->flags,
 * sc->offload_map, if_capenable are all race prone.
 */
int
t4_listen_start(struct toedev *tod, struct tcpcb *tp)
{
	struct adapter *sc = tod->tod_softc;
	struct vi_info *vi;
	struct port_info *pi;
	struct inpcb *inp = tp->t_inpcb;
	struct listen_ctx *lctx;
	int i, rc, v;

	INP_WLOCK_ASSERT(inp);

	/* Don't start a hardware listener for any loopback address. */
	if (inp->inp_vflag & INP_IPV6 && IN6_IS_ADDR_LOOPBACK(&inp->in6p_laddr))
		return (0);
	if (!(inp->inp_vflag & INP_IPV6) &&
	    IN_LOOPBACK(ntohl(inp->inp_laddr.s_addr)))
		return (0);
#if 0
	ADAPTER_LOCK(sc);
	if (IS_BUSY(sc)) {
		log(LOG_ERR, "%s: listen request ignored, %s is busy",
		    __func__, device_get_nameunit(sc->dev));
		goto done;
	}

	KASSERT(uld_active(sc, ULD_TOM),
	    ("%s: TOM not initialized", __func__));
#endif

	/*
	 * Find an initialized VI with IFCAP_TOE (4 or 6).  We'll use the first
	 * such VI's queues to send the passive open and receive the reply to
	 * it.
	 *
	 * XXX: need a way to mark a port in use by offload.  if_cxgbe should
	 * then reject any attempt to bring down such a port (and maybe reject
	 * attempts to disable IFCAP_TOE on that port too?).
	 */
	for_each_port(sc, i) {
		pi = sc->port[i];
		for_each_vi(pi, v, vi) {
			if (vi->flags & VI_INIT_DONE &&
			    vi->ifp->if_capenable & IFCAP_TOE)
				goto found;
		}
	}
	goto done;	/* no port that's UP with IFCAP_TOE enabled */
found:

	if (listen_hash_find(sc, inp) != NULL)
		goto done;	/* already setup */

	lctx = alloc_lctx(sc, inp, vi);
	if (lctx == NULL) {
		log(LOG_ERR,
		    "%s: listen request ignored, %s couldn't allocate lctx\n",
		    __func__, device_get_nameunit(sc->dev));
		goto done;
	}
	listen_hash_add(sc, lctx);

	CTR6(KTR_CXGBE, "%s: stid %u (%s), lctx %p, inp %p vflag 0x%x",
	    __func__, lctx->stid, tcpstates[tp->t_state], lctx, inp,
	    inp->inp_vflag);

	if (inp->inp_vflag & INP_IPV6)
		rc = create_server6(sc, lctx);
	else
		rc = create_server(sc, lctx);
	if (rc != 0) {
		log(LOG_ERR, "%s: %s failed to create hw listener: %d.\n",
		    __func__, device_get_nameunit(sc->dev), rc);
		(void) listen_hash_del(sc, inp);
		inp = release_lctx(sc, lctx);
		/* can't be freed, host stack has a reference */
		KASSERT(inp != NULL, ("%s: inp freed", __func__));
		goto done;
	}
	lctx->flags |= LCTX_RPL_PENDING;
done:
#if 0
	ADAPTER_UNLOCK(sc);
#endif
	return (0);
}

int
t4_listen_stop(struct toedev *tod, struct tcpcb *tp)
{
	struct listen_ctx *lctx;
	struct adapter *sc = tod->tod_softc;
	struct inpcb *inp = tp->t_inpcb;
	struct synq_entry *synqe;

	INP_WLOCK_ASSERT(inp);

	lctx = listen_hash_del(sc, inp);
	if (lctx == NULL)
		return (ENOENT);	/* no hardware listener for this inp */

	CTR4(KTR_CXGBE, "%s: stid %u, lctx %p, flags %x", __func__, lctx->stid,
	    lctx, lctx->flags);

	/*
	 * If the reply to the PASS_OPEN is still pending we'll wait for it to
	 * arrive and clean up when it does.
	 */
	if (lctx->flags & LCTX_RPL_PENDING) {
		KASSERT(TAILQ_EMPTY(&lctx->synq),
		    ("%s: synq not empty.", __func__));
		return (EINPROGRESS);
	}

	/*
	 * The host stack will abort all the connections on the listening
	 * socket's so_comp.  It doesn't know about the connections on the synq
	 * so we need to take care of those.
	 */
	TAILQ_FOREACH(synqe, &lctx->synq, link) {
		if (synqe->flags & TPF_SYNQE_HAS_L2TE)
			send_reset_synqe(tod, synqe);
	}

	destroy_server(sc, lctx);
	return (0);
}

static inline void
hold_synqe(struct synq_entry *synqe)
{

	refcount_acquire(&synqe->refcnt);
}

static inline void
release_synqe(struct synq_entry *synqe)
{

	if (refcount_release(&synqe->refcnt)) {
		int needfree = synqe->flags & TPF_SYNQE_NEEDFREE;

		m_freem(synqe->syn);
		if (needfree)
			free(synqe, M_CXGBE);
	}
}

void
t4_syncache_added(struct toedev *tod __unused, void *arg)
{
	struct synq_entry *synqe = arg;

	hold_synqe(synqe);
}

void
t4_syncache_removed(struct toedev *tod __unused, void *arg)
{
	struct synq_entry *synqe = arg;

	release_synqe(synqe);
}

int
t4_syncache_respond(struct toedev *tod, void *arg, struct mbuf *m)
{
	struct adapter *sc = tod->tod_softc;
	struct synq_entry *synqe = arg;
	struct wrqe *wr;
	struct l2t_entry *e;
	struct tcpopt to;
	struct ip *ip = mtod(m, struct ip *);
	struct tcphdr *th;

	wr = (struct wrqe *)atomic_readandclear_ptr(&synqe->wr);
	if (wr == NULL) {
		m_freem(m);
		return (EALREADY);
	}

	if (ip->ip_v == IPVERSION)
		th = (void *)(ip + 1);
	else
		th = (void *)((struct ip6_hdr *)ip + 1);
	bzero(&to, sizeof(to));
	tcp_dooptions(&to, (void *)(th + 1), (th->th_off << 2) - sizeof(*th),
	    TO_SYN);

	/* save these for later */
	synqe->iss = be32toh(th->th_seq);
	synqe->ts = to.to_tsval;

	if (chip_id(sc) >= CHELSIO_T5) {
		struct cpl_t5_pass_accept_rpl *rpl5 = wrtod(wr);

		rpl5->iss = th->th_seq;
	}

	e = &sc->l2t->l2tab[synqe->l2e_idx];
	t4_l2t_send(sc, wr, e);

	m_freem(m);	/* don't need this any more */
	return (0);
}

static int
do_pass_open_rpl(struct sge_iq *iq, const struct rss_header *rss,
    struct mbuf *m)
{
	struct adapter *sc = iq->adapter;
	const struct cpl_pass_open_rpl *cpl = (const void *)(rss + 1);
	int stid = GET_TID(cpl);
	unsigned int status = cpl->status;
	struct listen_ctx *lctx = lookup_stid(sc, stid);
	struct inpcb *inp = lctx->inp;
#ifdef INVARIANTS
	unsigned int opcode = G_CPL_OPCODE(be32toh(OPCODE_TID(cpl)));
#endif

	KASSERT(opcode == CPL_PASS_OPEN_RPL,
	    ("%s: unexpected opcode 0x%x", __func__, opcode));
	KASSERT(m == NULL, ("%s: wasn't expecting payload", __func__));
	KASSERT(lctx->stid == stid, ("%s: lctx stid mismatch", __func__));

	INP_WLOCK(inp);

	CTR4(KTR_CXGBE, "%s: stid %d, status %u, flags 0x%x",
	    __func__, stid, status, lctx->flags);

	lctx->flags &= ~LCTX_RPL_PENDING;

	if (status != CPL_ERR_NONE)
		log(LOG_ERR, "listener (stid %u) failed: %d\n", stid, status);

#ifdef INVARIANTS
	/*
	 * If the inp has been dropped (listening socket closed) then
	 * listen_stop must have run and taken the inp out of the hash.
	 */
	if (inp->inp_flags & INP_DROPPED) {
		KASSERT(listen_hash_del(sc, inp) == NULL,
		    ("%s: inp %p still in listen hash", __func__, inp));
	}
#endif

	if (inp->inp_flags & INP_DROPPED && status != CPL_ERR_NONE) {
		if (release_lctx(sc, lctx) != NULL)
			INP_WUNLOCK(inp);
		return (status);
	}

	/*
	 * Listening socket stopped listening earlier and now the chip tells us
	 * it has started the hardware listener.  Stop it; the lctx will be
	 * released in do_close_server_rpl.
	 */
	if (inp->inp_flags & INP_DROPPED) {
		destroy_server(sc, lctx);
		INP_WUNLOCK(inp);
		return (status);
	}

	/*
	 * Failed to start hardware listener.  Take inp out of the hash and
	 * release our reference on it.  An error message has been logged
	 * already.
	 */
	if (status != CPL_ERR_NONE) {
		listen_hash_del(sc, inp);
		if (release_lctx(sc, lctx) != NULL)
			INP_WUNLOCK(inp);
		return (status);
	}

	/* hardware listener open for business */

	INP_WUNLOCK(inp);
	return (status);
}

static int
do_close_server_rpl(struct sge_iq *iq, const struct rss_header *rss,
    struct mbuf *m)
{
	struct adapter *sc = iq->adapter;
	const struct cpl_close_listsvr_rpl *cpl = (const void *)(rss + 1);
	int stid = GET_TID(cpl);
	unsigned int status = cpl->status;
	struct listen_ctx *lctx = lookup_stid(sc, stid);
	struct inpcb *inp = lctx->inp;
#ifdef INVARIANTS
	unsigned int opcode = G_CPL_OPCODE(be32toh(OPCODE_TID(cpl)));
#endif

	KASSERT(opcode == CPL_CLOSE_LISTSRV_RPL,
	    ("%s: unexpected opcode 0x%x", __func__, opcode));
	KASSERT(m == NULL, ("%s: wasn't expecting payload", __func__));
	KASSERT(lctx->stid == stid, ("%s: lctx stid mismatch", __func__));

	CTR3(KTR_CXGBE, "%s: stid %u, status %u", __func__, stid, status);

	if (status != CPL_ERR_NONE) {
		log(LOG_ERR, "%s: failed (%u) to close listener for stid %u\n",
		    __func__, status, stid);
		return (status);
	}

	INP_WLOCK(inp);
	inp = release_lctx(sc, lctx);
	if (inp != NULL)
		INP_WUNLOCK(inp);

	return (status);
}

static void
done_with_synqe(struct adapter *sc, struct synq_entry *synqe)
{
	struct listen_ctx *lctx = synqe->lctx;
	struct inpcb *inp = lctx->inp;
	struct vi_info *vi = synqe->syn->m_pkthdr.rcvif->if_softc;
	struct l2t_entry *e = &sc->l2t->l2tab[synqe->l2e_idx];
	int ntids;

	INP_WLOCK_ASSERT(inp);
	ntids = inp->inp_vflag & INP_IPV6 ? 2 : 1;

	TAILQ_REMOVE(&lctx->synq, synqe, link);
	inp = release_lctx(sc, lctx);
	if (inp)
		INP_WUNLOCK(inp);
	remove_tid(sc, synqe->tid, ntids);
	release_tid(sc, synqe->tid, &sc->sge.ctrlq[vi->pi->port_id]);
	t4_l2t_release(e);
	release_synqe(synqe);	/* removed from synq list */
}

int
do_abort_req_synqe(struct sge_iq *iq, const struct rss_header *rss,
    struct mbuf *m)
{
	struct adapter *sc = iq->adapter;
	const struct cpl_abort_req_rss *cpl = (const void *)(rss + 1);
	unsigned int tid = GET_TID(cpl);
	struct synq_entry *synqe = lookup_tid(sc, tid);
	struct listen_ctx *lctx = synqe->lctx;
	struct inpcb *inp = lctx->inp;
	int txqid;
	struct sge_wrq *ofld_txq;
#ifdef INVARIANTS
	unsigned int opcode = G_CPL_OPCODE(be32toh(OPCODE_TID(cpl)));
#endif

	KASSERT(opcode == CPL_ABORT_REQ_RSS,
	    ("%s: unexpected opcode 0x%x", __func__, opcode));
	KASSERT(m == NULL, ("%s: wasn't expecting payload", __func__));
	KASSERT(synqe->tid == tid, ("%s: toep tid mismatch", __func__));

	CTR6(KTR_CXGBE, "%s: tid %u, synqe %p (0x%x), lctx %p, status %d",
	    __func__, tid, synqe, synqe->flags, synqe->lctx, cpl->status);

	if (negative_advice(cpl->status))
		return (0);	/* Ignore negative advice */

	INP_WLOCK(inp);

	get_qids_from_mbuf(synqe->syn, &txqid, NULL);
	ofld_txq = &sc->sge.ofld_txq[txqid];

	/*
	 * If we'd initiated an abort earlier the reply to it is responsible for
	 * cleaning up resources.  Otherwise we tear everything down right here
	 * right now.  We owe the T4 a CPL_ABORT_RPL no matter what.
	 */
	if (synqe->flags & TPF_ABORT_SHUTDOWN) {
		INP_WUNLOCK(inp);
		goto done;
	}

	done_with_synqe(sc, synqe);
	/* inp lock released by done_with_synqe */
done:
	send_abort_rpl(sc, ofld_txq, tid, CPL_ABORT_NO_RST);
	return (0);
}

int
do_abort_rpl_synqe(struct sge_iq *iq, const struct rss_header *rss,
    struct mbuf *m)
{
	struct adapter *sc = iq->adapter;
	const struct cpl_abort_rpl_rss *cpl = (const void *)(rss + 1);
	unsigned int tid = GET_TID(cpl);
	struct synq_entry *synqe = lookup_tid(sc, tid);
	struct listen_ctx *lctx = synqe->lctx;
	struct inpcb *inp = lctx->inp;
#ifdef INVARIANTS
	unsigned int opcode = G_CPL_OPCODE(be32toh(OPCODE_TID(cpl)));
#endif

	KASSERT(opcode == CPL_ABORT_RPL_RSS,
	    ("%s: unexpected opcode 0x%x", __func__, opcode));
	KASSERT(m == NULL, ("%s: wasn't expecting payload", __func__));
	KASSERT(synqe->tid == tid, ("%s: toep tid mismatch", __func__));

	CTR6(KTR_CXGBE, "%s: tid %u, synqe %p (0x%x), lctx %p, status %d",
	    __func__, tid, synqe, synqe->flags, synqe->lctx, cpl->status);

	INP_WLOCK(inp);
	KASSERT(synqe->flags & TPF_ABORT_SHUTDOWN,
	    ("%s: wasn't expecting abort reply for synqe %p (0x%x)",
	    __func__, synqe, synqe->flags));

	done_with_synqe(sc, synqe);
	/* inp lock released by done_with_synqe */

	return (0);
}

void
t4_offload_socket(struct toedev *tod, void *arg, struct socket *so)
{
	struct adapter *sc = tod->tod_softc;
	struct synq_entry *synqe = arg;
#ifdef INVARIANTS
	struct inpcb *inp = sotoinpcb(so);
#endif
	struct cpl_pass_establish *cpl = mtod(synqe->syn, void *);
	struct toepcb *toep = *(struct toepcb **)(cpl + 1);

	INP_INFO_RLOCK_ASSERT(&V_tcbinfo); /* prevents bad race with accept() */
	INP_WLOCK_ASSERT(inp);
	KASSERT(synqe->flags & TPF_SYNQE,
	    ("%s: %p not a synq_entry?", __func__, arg));

	offload_socket(so, toep);
	make_established(toep, cpl->snd_isn, cpl->rcv_isn, cpl->tcp_opt);
	toep->flags |= TPF_CPL_PENDING;
	update_tid(sc, synqe->tid, toep);
	synqe->flags |= TPF_SYNQE_EXPANDED;
}

static inline void
save_qids_in_mbuf(struct mbuf *m, struct vi_info *vi)
{
	uint32_t txqid, rxqid;

	txqid = (arc4random() % vi->nofldtxq) + vi->first_ofld_txq;
	rxqid = (arc4random() % vi->nofldrxq) + vi->first_ofld_rxq;

	m->m_pkthdr.flowid = (txqid << 16) | (rxqid & 0xffff);
}

static inline void
get_qids_from_mbuf(struct mbuf *m, int *txqid, int *rxqid)
{

	if (txqid)
		*txqid = m->m_pkthdr.flowid >> 16;
	if (rxqid)
		*rxqid = m->m_pkthdr.flowid & 0xffff;
}

/*
 * Use the trailing space in the mbuf in which the PASS_ACCEPT_REQ arrived to
 * store some state temporarily.
 */
static struct synq_entry *
mbuf_to_synqe(struct mbuf *m)
{
	int len = roundup2(sizeof (struct synq_entry), 8);
	int tspace = M_TRAILINGSPACE(m);
	struct synq_entry *synqe = NULL;

	if (tspace < len) {
		synqe = malloc(sizeof(*synqe), M_CXGBE, M_NOWAIT);
		if (synqe == NULL)
			return (NULL);
		synqe->flags = TPF_SYNQE | TPF_SYNQE_NEEDFREE;
	} else {
		synqe = (void *)(m->m_data + m->m_len + tspace - len);
		synqe->flags = TPF_SYNQE;
	}

	return (synqe);
}

static void
t4opt_to_tcpopt(const struct tcp_options *t4opt, struct tcpopt *to)
{
	bzero(to, sizeof(*to));

	if (t4opt->mss) {
		to->to_flags |= TOF_MSS;
		to->to_mss = be16toh(t4opt->mss);
	}

	if (t4opt->wsf) {
		to->to_flags |= TOF_SCALE;
		to->to_wscale = t4opt->wsf;
	}

	if (t4opt->tstamp)
		to->to_flags |= TOF_TS;

	if (t4opt->sack)
		to->to_flags |= TOF_SACKPERM;
}

/*
 * Options2 for passive open.
 */
static uint32_t
calc_opt2p(struct adapter *sc, struct port_info *pi, int rxqid,
    const struct tcp_options *tcpopt, struct tcphdr *th, int ulp_mode)
{
	struct sge_ofld_rxq *ofld_rxq = &sc->sge.ofld_rxq[rxqid];
	uint32_t opt2;

	opt2 = V_TX_QUEUE(sc->params.tp.tx_modq[pi->tx_chan]) |
	    F_RSS_QUEUE_VALID | V_RSS_QUEUE(ofld_rxq->iq.abs_id);

	if (V_tcp_do_rfc1323) {
		if (tcpopt->tstamp)
			opt2 |= F_TSTAMPS_EN;
		if (tcpopt->sack)
			opt2 |= F_SACK_EN;
		if (tcpopt->wsf <= 14)
			opt2 |= F_WND_SCALE_EN;
	}

	if (V_tcp_do_ecn && th->th_flags & (TH_ECE | TH_CWR))
		opt2 |= F_CCTRL_ECN;

	/* RX_COALESCE is always a valid value (0 or M_RX_COALESCE). */
	if (is_t4(sc))
		opt2 |= F_RX_COALESCE_VALID;
	else {
		opt2 |= F_T5_OPT_2_VALID;
		opt2 |= F_T5_ISS;
	}
	if (sc->tt.rx_coalesce)
		opt2 |= V_RX_COALESCE(M_RX_COALESCE);

	if (sc->tt.cong_algorithm != -1)
		opt2 |= V_CONG_CNTRL(sc->tt.cong_algorithm & M_CONG_CNTRL);

#ifdef USE_DDP_RX_FLOW_CONTROL
	if (ulp_mode == ULP_MODE_TCPDDP)
		opt2 |= F_RX_FC_VALID | F_RX_FC_DDP;
#endif

	return htobe32(opt2);
}

static void
pass_accept_req_to_protohdrs(struct adapter *sc, const struct mbuf *m,
    struct in_conninfo *inc, struct tcphdr *th)
{
	const struct cpl_pass_accept_req *cpl = mtod(m, const void *);
	const struct ether_header *eh;
	unsigned int hlen = be32toh(cpl->hdr_len);
	uintptr_t l3hdr;
	const struct tcphdr *tcp;

	eh = (const void *)(cpl + 1);
	if (chip_id(sc) >= CHELSIO_T6) {
		l3hdr = ((uintptr_t)eh + G_T6_ETH_HDR_LEN(hlen));
		tcp = (const void *)(l3hdr + G_T6_IP_HDR_LEN(hlen));
	} else {
		l3hdr = ((uintptr_t)eh + G_ETH_HDR_LEN(hlen));
		tcp = (const void *)(l3hdr + G_IP_HDR_LEN(hlen));
	}

	if (inc) {
		bzero(inc, sizeof(*inc));
		inc->inc_fport = tcp->th_sport;
		inc->inc_lport = tcp->th_dport;
		if (((struct ip *)l3hdr)->ip_v == IPVERSION) {
			const struct ip *ip = (const void *)l3hdr;

			inc->inc_faddr = ip->ip_src;
			inc->inc_laddr = ip->ip_dst;
		} else {
			const struct ip6_hdr *ip6 = (const void *)l3hdr;

			inc->inc_flags |= INC_ISIPV6;
			inc->inc6_faddr = ip6->ip6_src;
			inc->inc6_laddr = ip6->ip6_dst;
		}
	}

	if (th) {
		bcopy(tcp, th, sizeof(*th));
		tcp_fields_to_host(th);		/* just like tcp_input */
	}
}

static struct l2t_entry *
get_l2te_for_nexthop(struct port_info *pi, struct ifnet *ifp,
    struct in_conninfo *inc)
{
	struct l2t_entry *e;
	struct sockaddr_in6 sin6;
	struct sockaddr *dst = (void *)&sin6;

	if (inc->inc_flags & INC_ISIPV6) {
		struct nhop6_basic nh6;

		bzero(dst, sizeof(struct sockaddr_in6));
		dst->sa_len = sizeof(struct sockaddr_in6);
		dst->sa_family = AF_INET6;

		if (IN6_IS_ADDR_LINKLOCAL(&inc->inc6_laddr)) {
			/* no need for route lookup */
			e = t4_l2t_get(pi, ifp, dst);
			return (e);
		}

		if (fib6_lookup_nh_basic(RT_DEFAULT_FIB, &inc->inc6_faddr,
		    0, 0, 0, &nh6) != 0)
			return (NULL);
		if (nh6.nh_ifp != ifp)
			return (NULL);
		((struct sockaddr_in6 *)dst)->sin6_addr = nh6.nh_addr;
	} else {
		struct nhop4_basic nh4;

		dst->sa_len = sizeof(struct sockaddr_in);
		dst->sa_family = AF_INET;

		if (fib4_lookup_nh_basic(RT_DEFAULT_FIB, inc->inc_faddr, 0, 0,
		    &nh4) != 0)
			return (NULL);
		if (nh4.nh_ifp != ifp)
			return (NULL);
		((struct sockaddr_in *)dst)->sin_addr = nh4.nh_addr;
	}

	e = t4_l2t_get(pi, ifp, dst);
	return (e);
}

#define REJECT_PASS_ACCEPT()	do { \
	reject_reason = __LINE__; \
	goto reject; \
} while (0)

/*
 * The context associated with a tid entry via insert_tid could be a synq_entry
 * or a toepcb.  The only way CPL handlers can tell is via a bit in these flags.
 */
CTASSERT(offsetof(struct toepcb, flags) == offsetof(struct synq_entry, flags));

/*
 * Incoming SYN on a listening socket.
 *
 * XXX: Every use of ifp in this routine has a bad race with up/down, toe/-toe,
 * etc.
 */
static int
do_pass_accept_req(struct sge_iq *iq, const struct rss_header *rss,
    struct mbuf *m)
{
	struct adapter *sc = iq->adapter;
	struct toedev *tod;
	const struct cpl_pass_accept_req *cpl = mtod(m, const void *);
	struct cpl_pass_accept_rpl *rpl;
	struct wrqe *wr;
	unsigned int stid = G_PASS_OPEN_TID(be32toh(cpl->tos_stid));
	unsigned int tid = GET_TID(cpl);
	struct listen_ctx *lctx = lookup_stid(sc, stid);
	struct inpcb *inp;
	struct socket *so;
	struct in_conninfo inc;
	struct tcphdr th;
	struct tcpopt to;
	struct port_info *pi;
	struct vi_info *vi;
	struct ifnet *hw_ifp, *ifp;
	struct l2t_entry *e = NULL;
	int rscale, mtu_idx, rx_credits, rxqid, ulp_mode;
	struct synq_entry *synqe = NULL;
	int reject_reason, v, ntids;
	uint16_t vid;
#ifdef INVARIANTS
	unsigned int opcode = G_CPL_OPCODE(be32toh(OPCODE_TID(cpl)));
#endif

	KASSERT(opcode == CPL_PASS_ACCEPT_REQ,
	    ("%s: unexpected opcode 0x%x", __func__, opcode));
	KASSERT(lctx->stid == stid, ("%s: lctx stid mismatch", __func__));

	CTR4(KTR_CXGBE, "%s: stid %u, tid %u, lctx %p", __func__, stid, tid,
	    lctx);

	pass_accept_req_to_protohdrs(sc, m, &inc, &th);
	t4opt_to_tcpopt(&cpl->tcpopt, &to);

	pi = sc->port[G_SYN_INTF(be16toh(cpl->l2info))];

	CURVNET_SET(lctx->vnet);

	/*
	 * Use the MAC index to lookup the associated VI.  If this SYN
	 * didn't match a perfect MAC filter, punt.
	 */
	if (!(be16toh(cpl->l2info) & F_SYN_XACT_MATCH)) {
		m_freem(m);
		m = NULL;
		REJECT_PASS_ACCEPT();
	}
	for_each_vi(pi, v, vi) {
		if (vi->xact_addr_filt == G_SYN_MAC_IDX(be16toh(cpl->l2info)))
			goto found;
	}
	m_freem(m);
	m = NULL;
	REJECT_PASS_ACCEPT();

found:
	hw_ifp = vi->ifp;	/* the (v)cxgbeX ifnet */
	m->m_pkthdr.rcvif = hw_ifp;
	tod = TOEDEV(hw_ifp);

	/*
	 * Figure out if there is a pseudo interface (vlan, lagg, etc.)
	 * involved.  Don't offload if the SYN had a VLAN tag and the vid
	 * doesn't match anything on this interface.
	 *
	 * XXX: lagg support, lagg + vlan support.
	 */
	vid = EVL_VLANOFTAG(be16toh(cpl->vlan));
	if (vid != 0xfff) {
		ifp = VLAN_DEVAT(hw_ifp, vid);
		if (ifp == NULL)
			REJECT_PASS_ACCEPT();
	} else
		ifp = hw_ifp;

	/*
	 * Don't offload if the peer requested a TCP option that's not known to
	 * the silicon.
	 */
	if (cpl->tcpopt.unknown)
		REJECT_PASS_ACCEPT();

	if (inc.inc_flags & INC_ISIPV6) {

		/* Don't offload if the ifcap isn't enabled */
		if ((ifp->if_capenable & IFCAP_TOE6) == 0)
			REJECT_PASS_ACCEPT();

		/*
		 * SYN must be directed to an IP6 address on this ifnet.  This
		 * is more restrictive than in6_localip.
		 */
		if (!in6_ifhasaddr(ifp, &inc.inc6_laddr))
			REJECT_PASS_ACCEPT();

		ntids = 2;
	} else {

		/* Don't offload if the ifcap isn't enabled */
		if ((ifp->if_capenable & IFCAP_TOE4) == 0)
			REJECT_PASS_ACCEPT();

		/*
		 * SYN must be directed to an IP address on this ifnet.  This
		 * is more restrictive than in_localip.
		 */
		if (!in_ifhasaddr(ifp, inc.inc_laddr))
			REJECT_PASS_ACCEPT();

		ntids = 1;
	}

	/*
	 * Don't offload if the ifnet that the SYN came in on is not in the same
	 * vnet as the listening socket.
	 */
	if (lctx->vnet != ifp->if_vnet)
		REJECT_PASS_ACCEPT();

	e = get_l2te_for_nexthop(pi, ifp, &inc);
	if (e == NULL)
		REJECT_PASS_ACCEPT();

	synqe = mbuf_to_synqe(m);
	if (synqe == NULL)
		REJECT_PASS_ACCEPT();

	wr = alloc_wrqe(is_t4(sc) ? sizeof(struct cpl_pass_accept_rpl) :
	    sizeof(struct cpl_t5_pass_accept_rpl), &sc->sge.ctrlq[pi->port_id]);
	if (wr == NULL)
		REJECT_PASS_ACCEPT();
	rpl = wrtod(wr);

	INP_INFO_RLOCK(&V_tcbinfo);	/* for 4-tuple check */

	/* Don't offload if the 4-tuple is already in use */
	if (toe_4tuple_check(&inc, &th, ifp) != 0) {
		INP_INFO_RUNLOCK(&V_tcbinfo);
		free(wr, M_CXGBE);
		REJECT_PASS_ACCEPT();
	}
	INP_INFO_RUNLOCK(&V_tcbinfo);

	inp = lctx->inp;		/* listening socket, not owned by TOE */
	INP_WLOCK(inp);

	/* Don't offload if the listening socket has closed */
	if (__predict_false(inp->inp_flags & INP_DROPPED)) {
		/*
		 * The listening socket has closed.  The reply from the TOE to
		 * our CPL_CLOSE_LISTSRV_REQ will ultimately release all
		 * resources tied to this listen context.
		 */
		INP_WUNLOCK(inp);
		free(wr, M_CXGBE);
		REJECT_PASS_ACCEPT();
	}
	so = inp->inp_socket;

	mtu_idx = find_best_mtu_idx(sc, &inc, be16toh(cpl->tcpopt.mss));
	rscale = cpl->tcpopt.wsf && V_tcp_do_rfc1323 ? select_rcv_wscale() : 0;
	SOCKBUF_LOCK(&so->so_rcv);
	/* opt0 rcv_bufsiz initially, assumes its normal meaning later */
	rx_credits = min(select_rcv_wnd(so) >> 10, M_RCV_BUFSIZ);
	SOCKBUF_UNLOCK(&so->so_rcv);

	save_qids_in_mbuf(m, vi);
	get_qids_from_mbuf(m, NULL, &rxqid);

	if (is_t4(sc))
		INIT_TP_WR_MIT_CPL(rpl, CPL_PASS_ACCEPT_RPL, tid);
	else {
		struct cpl_t5_pass_accept_rpl *rpl5 = (void *)rpl;

		INIT_TP_WR_MIT_CPL(rpl5, CPL_PASS_ACCEPT_RPL, tid);
	}
	if (sc->tt.ddp && (so->so_options & SO_NO_DDP) == 0) {
		ulp_mode = ULP_MODE_TCPDDP;
		synqe->flags |= TPF_SYNQE_TCPDDP;
	} else
		ulp_mode = ULP_MODE_NONE;
	rpl->opt0 = calc_opt0(so, vi, e, mtu_idx, rscale, rx_credits, ulp_mode);
	rpl->opt2 = calc_opt2p(sc, pi, rxqid, &cpl->tcpopt, &th, ulp_mode);

	synqe->tid = tid;
	synqe->lctx = lctx;
	synqe->syn = m;
	m = NULL;
	refcount_init(&synqe->refcnt, 1);	/* 1 means extra hold */
	synqe->l2e_idx = e->idx;
	synqe->rcv_bufsize = rx_credits;
	atomic_store_rel_ptr(&synqe->wr, (uintptr_t)wr);

	insert_tid(sc, tid, synqe, ntids);
	TAILQ_INSERT_TAIL(&lctx->synq, synqe, link);
	hold_synqe(synqe);	/* hold for the duration it's in the synq */
	hold_lctx(lctx);	/* A synqe on the list has a ref on its lctx */

	/*
	 * If all goes well t4_syncache_respond will get called during
	 * syncache_add.  Note that syncache_add releases the pcb lock.
	 */
	toe_syncache_add(&inc, &to, &th, inp, tod, synqe);
	INP_UNLOCK_ASSERT(inp);	/* ok to assert, we have a ref on the inp */

	/*
	 * If we replied during syncache_add (synqe->wr has been consumed),
	 * good.  Otherwise, set it to 0 so that further syncache_respond
	 * attempts by the kernel will be ignored.
	 */
	if (atomic_cmpset_ptr(&synqe->wr, (uintptr_t)wr, 0)) {

		/*
		 * syncache may or may not have a hold on the synqe, which may
		 * or may not be stashed in the original SYN mbuf passed to us.
		 * Just copy it over instead of dealing with all possibilities.
		 */
		m = m_dup(synqe->syn, M_NOWAIT);
		if (m)
			m->m_pkthdr.rcvif = hw_ifp;

		remove_tid(sc, synqe->tid, ntids);
		free(wr, M_CXGBE);

		/* Yank the synqe out of the lctx synq. */
		INP_WLOCK(inp);
		TAILQ_REMOVE(&lctx->synq, synqe, link);
		release_synqe(synqe);	/* removed from synq list */
		inp = release_lctx(sc, lctx);
		if (inp)
			INP_WUNLOCK(inp);

		release_synqe(synqe);	/* extra hold */
		REJECT_PASS_ACCEPT();
	}

	CTR5(KTR_CXGBE, "%s: stid %u, tid %u, lctx %p, synqe %p, SYNACK",
	    __func__, stid, tid, lctx, synqe);

	INP_WLOCK(inp);
	synqe->flags |= TPF_SYNQE_HAS_L2TE;
	if (__predict_false(inp->inp_flags & INP_DROPPED)) {
		/*
		 * Listening socket closed but tod_listen_stop did not abort
		 * this tid because there was no L2T entry for the tid at that
		 * time.  Abort it now.  The reply to the abort will clean up.
		 */
		CTR6(KTR_CXGBE,
		    "%s: stid %u, tid %u, lctx %p, synqe %p (0x%x), ABORT",
		    __func__, stid, tid, lctx, synqe, synqe->flags);
		if (!(synqe->flags & TPF_SYNQE_EXPANDED))
			send_reset_synqe(tod, synqe);
		INP_WUNLOCK(inp);
		CURVNET_RESTORE();

		release_synqe(synqe);	/* extra hold */
		return (__LINE__);
	}
	INP_WUNLOCK(inp);
	CURVNET_RESTORE();

	release_synqe(synqe);	/* extra hold */
	return (0);
reject:
	CURVNET_RESTORE();
	CTR4(KTR_CXGBE, "%s: stid %u, tid %u, REJECT (%d)", __func__, stid, tid,
	    reject_reason);

	if (e)
		t4_l2t_release(e);
	release_tid(sc, tid, lctx->ctrlq);

	if (__predict_true(m != NULL)) {
		m_adj(m, sizeof(*cpl));
		m->m_pkthdr.csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID |
		    CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
		m->m_pkthdr.csum_data = 0xffff;
		hw_ifp->if_input(hw_ifp, m);
	}

	return (reject_reason);
}

static void
synqe_to_protohdrs(struct adapter *sc, struct synq_entry *synqe,
    const struct cpl_pass_establish *cpl, struct in_conninfo *inc,
    struct tcphdr *th, struct tcpopt *to)
{
	uint16_t tcp_opt = be16toh(cpl->tcp_opt);

	/* start off with the original SYN */
	pass_accept_req_to_protohdrs(sc, synqe->syn, inc, th);

	/* modify parts to make it look like the ACK to our SYN|ACK */
	th->th_flags = TH_ACK;
	th->th_ack = synqe->iss + 1;
	th->th_seq = be32toh(cpl->rcv_isn);
	bzero(to, sizeof(*to));
	if (G_TCPOPT_TSTAMP(tcp_opt)) {
		to->to_flags |= TOF_TS;
		to->to_tsecr = synqe->ts;
	}
}

static int
do_pass_establish(struct sge_iq *iq, const struct rss_header *rss,
    struct mbuf *m)
{
	struct adapter *sc = iq->adapter;
	struct vi_info *vi;
	struct ifnet *ifp;
	const struct cpl_pass_establish *cpl = (const void *)(rss + 1);
#if defined(KTR) || defined(INVARIANTS)
	unsigned int stid = G_PASS_OPEN_TID(be32toh(cpl->tos_stid));
#endif
	unsigned int tid = GET_TID(cpl);
	struct synq_entry *synqe = lookup_tid(sc, tid);
	struct listen_ctx *lctx = synqe->lctx;
	struct inpcb *inp = lctx->inp, *new_inp;
	struct socket *so;
	struct tcphdr th;
	struct tcpopt to;
	struct in_conninfo inc;
	struct toepcb *toep;
	u_int txqid, rxqid;
#ifdef INVARIANTS
	unsigned int opcode = G_CPL_OPCODE(be32toh(OPCODE_TID(cpl)));
#endif

	KASSERT(opcode == CPL_PASS_ESTABLISH,
	    ("%s: unexpected opcode 0x%x", __func__, opcode));
	KASSERT(m == NULL, ("%s: wasn't expecting payload", __func__));
	KASSERT(lctx->stid == stid, ("%s: lctx stid mismatch", __func__));
	KASSERT(synqe->flags & TPF_SYNQE,
	    ("%s: tid %u (ctx %p) not a synqe", __func__, tid, synqe));

	CURVNET_SET(lctx->vnet);
	INP_INFO_RLOCK(&V_tcbinfo);	/* for syncache_expand */
	INP_WLOCK(inp);

	CTR6(KTR_CXGBE,
	    "%s: stid %u, tid %u, synqe %p (0x%x), inp_flags 0x%x",
	    __func__, stid, tid, synqe, synqe->flags, inp->inp_flags);

	if (__predict_false(inp->inp_flags & INP_DROPPED)) {

		if (synqe->flags & TPF_SYNQE_HAS_L2TE) {
			KASSERT(synqe->flags & TPF_ABORT_SHUTDOWN,
			    ("%s: listen socket closed but tid %u not aborted.",
			    __func__, tid));
		}

		INP_WUNLOCK(inp);
		INP_INFO_RUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return (0);
	}

	ifp = synqe->syn->m_pkthdr.rcvif;
	vi = ifp->if_softc;
	KASSERT(vi->pi->adapter == sc,
	    ("%s: vi %p, sc %p mismatch", __func__, vi, sc));

	get_qids_from_mbuf(synqe->syn, &txqid, &rxqid);
	KASSERT(rxqid == iq_to_ofld_rxq(iq) - &sc->sge.ofld_rxq[0],
	    ("%s: CPL arrived on unexpected rxq.  %d %d", __func__, rxqid,
	    (int)(iq_to_ofld_rxq(iq) - &sc->sge.ofld_rxq[0])));

	toep = alloc_toepcb(vi, txqid, rxqid, M_NOWAIT);
	if (toep == NULL) {
reset:
		/*
		 * The reply to this abort will perform final cleanup.  There is
		 * no need to check for HAS_L2TE here.  We can be here only if
		 * we responded to the PASS_ACCEPT_REQ, and our response had the
		 * L2T idx.
		 */
		send_reset_synqe(TOEDEV(ifp), synqe);
		INP_WUNLOCK(inp);
		INP_INFO_RUNLOCK(&V_tcbinfo);
		CURVNET_RESTORE();
		return (0);
	}
	toep->tid = tid;
	toep->l2te = &sc->l2t->l2tab[synqe->l2e_idx];
	if (synqe->flags & TPF_SYNQE_TCPDDP)
		set_tcpddp_ulp_mode(toep);
	else
		toep->ulp_mode = ULP_MODE_NONE;
	/* opt0 rcv_bufsiz initially, assumes its normal meaning later */
	toep->rx_credits = synqe->rcv_bufsize;

	so = inp->inp_socket;
	KASSERT(so != NULL, ("%s: socket is NULL", __func__));

	/* Come up with something that syncache_expand should be ok with. */
	synqe_to_protohdrs(sc, synqe, cpl, &inc, &th, &to);

	/*
	 * No more need for anything in the mbuf that carried the
	 * CPL_PASS_ACCEPT_REQ.  Drop the CPL_PASS_ESTABLISH and toep pointer
	 * there.  XXX: bad form but I don't want to increase the size of synqe.
	 */
	m = synqe->syn;
	KASSERT(sizeof(*cpl) + sizeof(toep) <= m->m_len,
	    ("%s: no room in mbuf %p (m_len %d)", __func__, m, m->m_len));
	bcopy(cpl, mtod(m, void *), sizeof(*cpl));
	*(struct toepcb **)(mtod(m, struct cpl_pass_establish *) + 1) = toep;

	if (!toe_syncache_expand(&inc, &to, &th, &so) || so == NULL) {
		free_toepcb(toep);
		goto reset;
	}

	/* New connection inpcb is already locked by syncache_expand(). */
	new_inp = sotoinpcb(so);
	INP_WLOCK_ASSERT(new_inp);
	MPASS(so->so_vnet == lctx->vnet);
	toep->vnet = lctx->vnet;
	if (inc.inc_flags & INC_ISIPV6)
		toep->ce = hold_lip(sc->tom_softc, &inc.inc6_laddr, lctx->ce);

	/*
	 * This is for the unlikely case where the syncache entry that we added
	 * has been evicted from the syncache, but the syncache_expand above
	 * works because of syncookies.
	 *
	 * XXX: we've held the tcbinfo lock throughout so there's no risk of
	 * anyone accept'ing a connection before we've installed our hooks, but
	 * this somewhat defeats the purpose of having a tod_offload_socket :-(
	 */
	if (__predict_false(!(synqe->flags & TPF_SYNQE_EXPANDED))) {
		tcp_timer_activate(intotcpcb(new_inp), TT_KEEP, 0);
		t4_offload_socket(TOEDEV(ifp), synqe, so);
	}

	INP_WUNLOCK(new_inp);

	/* Done with the synqe */
	TAILQ_REMOVE(&lctx->synq, synqe, link);
	inp = release_lctx(sc, lctx);
	if (inp != NULL)
		INP_WUNLOCK(inp);
	INP_INFO_RUNLOCK(&V_tcbinfo);
	CURVNET_RESTORE();
	release_synqe(synqe);

	return (0);
}

void
t4_init_listen_cpl_handlers(void)
{

	t4_register_cpl_handler(CPL_PASS_OPEN_RPL, do_pass_open_rpl);
	t4_register_cpl_handler(CPL_CLOSE_LISTSRV_RPL, do_close_server_rpl);
	t4_register_cpl_handler(CPL_PASS_ACCEPT_REQ, do_pass_accept_req);
	t4_register_cpl_handler(CPL_PASS_ESTABLISH, do_pass_establish);
}

void
t4_uninit_listen_cpl_handlers(void)
{

	t4_register_cpl_handler(CPL_PASS_OPEN_RPL, NULL);
	t4_register_cpl_handler(CPL_CLOSE_LISTSRV_RPL, NULL);
	t4_register_cpl_handler(CPL_PASS_ACCEPT_REQ, NULL);
	t4_register_cpl_handler(CPL_PASS_ESTABLISH, NULL);
}
#endif