/* * Copyright (C) 2014-2018 Giuseppe Lettieri * All rights reserved. * * 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. */ /* $FreeBSD: stable/11/sys/dev/netmap/netmap_pipe.c 344047 2019-02-12 09:26:05Z vmaffione $ */ #if defined(__FreeBSD__) #include /* prerequisite */ #include #include #include /* defines used in kernel.h */ #include /* types used in module initialization */ #include #include #include #include #include #include #include /* sockaddrs */ #include #include #include /* bus_dmamap_* */ #include #elif defined(linux) #include "bsd_glue.h" #elif defined(__APPLE__) #warning OSX support is only partial #include "osx_glue.h" #elif defined(_WIN32) #include "win_glue.h" #else #error Unsupported platform #endif /* unsupported */ /* * common headers */ #include #include #include #ifdef WITH_PIPES #define NM_PIPE_MAXSLOTS 4096 #define NM_PIPE_MAXRINGS 256 static int netmap_default_pipes = 0; /* ignored, kept for compatibility */ SYSBEGIN(vars_pipes); SYSCTL_DECL(_dev_netmap); SYSCTL_INT(_dev_netmap, OID_AUTO, default_pipes, CTLFLAG_RW, &netmap_default_pipes, 0, "For compatibility only"); SYSEND; /* allocate the pipe array in the parent adapter */ static int nm_pipe_alloc(struct netmap_adapter *na, u_int npipes) { size_t old_len, len; struct netmap_pipe_adapter **npa; if (npipes <= na->na_max_pipes) /* we already have more entries that requested */ return 0; if (npipes < na->na_next_pipe || npipes > NM_MAXPIPES) return EINVAL; old_len = sizeof(struct netmap_pipe_adapter *)*na->na_max_pipes; len = sizeof(struct netmap_pipe_adapter *) * npipes; npa = nm_os_realloc(na->na_pipes, len, old_len); if (npa == NULL) return ENOMEM; na->na_pipes = npa; na->na_max_pipes = npipes; return 0; } /* deallocate the parent array in the parent adapter */ void netmap_pipe_dealloc(struct netmap_adapter *na) { if (na->na_pipes) { if (na->na_next_pipe > 0) { nm_prerr("freeing not empty pipe array for %s (%d dangling pipes)!", na->name, na->na_next_pipe); } nm_os_free(na->na_pipes); na->na_pipes = NULL; na->na_max_pipes = 0; na->na_next_pipe = 0; } } /* find a pipe endpoint with the given id among the parent's pipes */ static struct netmap_pipe_adapter * netmap_pipe_find(struct netmap_adapter *parent, const char *pipe_id) { int i; struct netmap_pipe_adapter *na; for (i = 0; i < parent->na_next_pipe; i++) { const char *na_pipe_id; na = parent->na_pipes[i]; na_pipe_id = strrchr(na->up.name, na->role == NM_PIPE_ROLE_MASTER ? '{' : '}'); KASSERT(na_pipe_id != NULL, ("Invalid pipe name")); ++na_pipe_id; if (!strcmp(na_pipe_id, pipe_id)) { return na; } } return NULL; } /* add a new pipe endpoint to the parent array */ static int netmap_pipe_add(struct netmap_adapter *parent, struct netmap_pipe_adapter *na) { if (parent->na_next_pipe >= parent->na_max_pipes) { u_int npipes = parent->na_max_pipes ? 2*parent->na_max_pipes : 2; int error = nm_pipe_alloc(parent, npipes); if (error) return error; } parent->na_pipes[parent->na_next_pipe] = na; na->parent_slot = parent->na_next_pipe; parent->na_next_pipe++; return 0; } /* remove the given pipe endpoint from the parent array */ static void netmap_pipe_remove(struct netmap_adapter *parent, struct netmap_pipe_adapter *na) { u_int n; n = --parent->na_next_pipe; if (n != na->parent_slot) { struct netmap_pipe_adapter **p = &parent->na_pipes[na->parent_slot]; *p = parent->na_pipes[n]; (*p)->parent_slot = na->parent_slot; } parent->na_pipes[n] = NULL; } int netmap_pipe_txsync(struct netmap_kring *txkring, int flags) { struct netmap_kring *rxkring = txkring->pipe; u_int k, lim = txkring->nkr_num_slots - 1, nk; int m; /* slots to transfer */ int complete; /* did we see a complete packet ? */ struct netmap_ring *txring = txkring->ring, *rxring = rxkring->ring; nm_prdis("%p: %s %x -> %s", txkring, txkring->name, flags, rxkring->name); nm_prdis(20, "TX before: hwcur %d hwtail %d cur %d head %d tail %d", txkring->nr_hwcur, txkring->nr_hwtail, txkring->rcur, txkring->rhead, txkring->rtail); /* update the hwtail */ txkring->nr_hwtail = txkring->pipe_tail; m = txkring->rhead - txkring->nr_hwcur; /* new slots */ if (m < 0) m += txkring->nkr_num_slots; if (m == 0) { /* nothing to send */ return 0; } for (k = txkring->nr_hwcur, nk = lim + 1, complete = 0; m; m--, k = nm_next(k, lim), nk = (complete ? k : nk)) { struct netmap_slot *rs = &rxring->slot[k]; struct netmap_slot *ts = &txring->slot[k]; *rs = *ts; if (ts->flags & NS_BUF_CHANGED) { ts->flags &= ~NS_BUF_CHANGED; } complete = !(ts->flags & NS_MOREFRAG); } txkring->nr_hwcur = k; nm_prdis(20, "TX after : hwcur %d hwtail %d cur %d head %d tail %d k %d", txkring->nr_hwcur, txkring->nr_hwtail, txkring->rcur, txkring->rhead, txkring->rtail, k); if (likely(nk <= lim)) { mb(); /* make sure the slots are updated before publishing them */ rxkring->pipe_tail = nk; /* only publish complete packets */ rxkring->nm_notify(rxkring, 0); } return 0; } int netmap_pipe_rxsync(struct netmap_kring *rxkring, int flags) { struct netmap_kring *txkring = rxkring->pipe; u_int k, lim = rxkring->nkr_num_slots - 1; int m; /* slots to release */ struct netmap_ring *txring = txkring->ring, *rxring = rxkring->ring; nm_prdis("%p: %s %x -> %s", txkring, txkring->name, flags, rxkring->name); nm_prdis(20, "RX before: hwcur %d hwtail %d cur %d head %d tail %d", rxkring->nr_hwcur, rxkring->nr_hwtail, rxkring->rcur, rxkring->rhead, rxkring->rtail); /* update the hwtail */ rxkring->nr_hwtail = rxkring->pipe_tail; m = rxkring->rhead - rxkring->nr_hwcur; /* released slots */ if (m < 0) m += rxkring->nkr_num_slots; if (m == 0) { /* nothing to release */ return 0; } for (k = rxkring->nr_hwcur; m; m--, k = nm_next(k, lim)) { struct netmap_slot *rs = &rxring->slot[k]; struct netmap_slot *ts = &txring->slot[k]; if (rs->flags & NS_BUF_CHANGED) { /* copy the slot and report the buffer change */ *ts = *rs; rs->flags &= ~NS_BUF_CHANGED; } } mb(); /* make sure the slots are updated before publishing them */ txkring->pipe_tail = nm_prev(k, lim); rxkring->nr_hwcur = k; nm_prdis(20, "RX after : hwcur %d hwtail %d cur %d head %d tail %d k %d", rxkring->nr_hwcur, rxkring->nr_hwtail, rxkring->rcur, rxkring->rhead, rxkring->rtail, k); txkring->nm_notify(txkring, 0); return 0; } /* Pipe endpoints are created and destroyed together, so that endopoints do not * have to check for the existence of their peer at each ?xsync. * * To play well with the existing netmap infrastructure (refcounts etc.), we * adopt the following strategy: * * 1) The first endpoint that is created also creates the other endpoint and * grabs a reference to it. * * state A) user1 --> endpoint1 --> endpoint2 * * 2) If, starting from state A, endpoint2 is then registered, endpoint1 gives * its reference to the user: * * state B) user1 --> endpoint1 endpoint2 <--- user2 * * 3) Assume that, starting from state B endpoint2 is closed. In the unregister * callback endpoint2 notes that endpoint1 is still active and adds a reference * from endpoint1 to itself. When user2 then releases her own reference, * endpoint2 is not destroyed and we are back to state A. A symmetrical state * would be reached if endpoint1 were released instead. * * 4) If, starting from state A, endpoint1 is closed, the destructor notes that * it owns a reference to endpoint2 and releases it. * * Something similar goes on for the creation and destruction of the krings. */ int netmap_pipe_krings_create_both(struct netmap_adapter *na, struct netmap_adapter *ona) { enum txrx t; int error; int i; /* case 1) below */ nm_prdis("%p: case 1, create both ends", na); error = netmap_krings_create(na, 0); if (error) return error; /* create the krings of the other end */ error = netmap_krings_create(ona, 0); if (error) goto del_krings1; /* cross link the krings and initialize the pipe_tails */ for_rx_tx(t) { enum txrx r = nm_txrx_swap(t); /* swap NR_TX <-> NR_RX */ for (i = 0; i < nma_get_nrings(na, t); i++) { struct netmap_kring *k1 = NMR(na, t)[i], *k2 = NMR(ona, r)[i]; k1->pipe = k2; k2->pipe = k1; /* mark all peer-adapter rings as fake */ k2->nr_kflags |= NKR_FAKERING; /* init tails */ k1->pipe_tail = k1->nr_hwtail; k2->pipe_tail = k2->nr_hwtail; } } return 0; del_krings1: netmap_krings_delete(na); return error; } /* netmap_pipe_krings_create. * * There are two cases: * * 1) state is * * usr1 --> e1 --> e2 * * and we are e1. We have to create both sets * of krings. * * 2) state is * * usr1 --> e1 --> e2 * * and we are e2. e1 is certainly registered and our * krings already exist. Nothing to do. */ static int netmap_pipe_krings_create(struct netmap_adapter *na) { struct netmap_pipe_adapter *pna = (struct netmap_pipe_adapter *)na; struct netmap_adapter *ona = &pna->peer->up; if (pna->peer_ref) return netmap_pipe_krings_create_both(na, ona); return 0; } int netmap_pipe_reg_both(struct netmap_adapter *na, struct netmap_adapter *ona) { int i, error = 0; enum txrx t; for_rx_tx(t) { for (i = 0; i < nma_get_nrings(na, t); i++) { struct netmap_kring *kring = NMR(na, t)[i]; if (nm_kring_pending_on(kring)) { /* mark the peer ring as needed */ kring->pipe->nr_kflags |= NKR_NEEDRING; } } } /* create all missing needed rings on the other end. * Either our end, or the other, has been marked as * fake, so the allocation will not be done twice. */ error = netmap_mem_rings_create(ona); if (error) return error; /* In case of no error we put our rings in netmap mode */ for_rx_tx(t) { for (i = 0; i < nma_get_nrings(na, t); i++) { struct netmap_kring *kring = NMR(na, t)[i]; if (nm_kring_pending_on(kring)) { struct netmap_kring *sring, *dring; kring->nr_mode = NKR_NETMAP_ON; if ((kring->nr_kflags & NKR_FAKERING) && (kring->pipe->nr_kflags & NKR_FAKERING)) { /* this is a re-open of a pipe * end-point kept alive by the other end. * We need to leave everything as it is */ continue; } /* copy the buffers from the non-fake ring */ if (kring->nr_kflags & NKR_FAKERING) { sring = kring->pipe; dring = kring; } else { sring = kring; dring = kring->pipe; } memcpy(dring->ring->slot, sring->ring->slot, sizeof(struct netmap_slot) * sring->nkr_num_slots); /* mark both rings as fake and needed, * so that buffers will not be * deleted by the standard machinery * (we will delete them by ourselves in * netmap_pipe_krings_delete) */ sring->nr_kflags |= (NKR_FAKERING | NKR_NEEDRING); dring->nr_kflags |= (NKR_FAKERING | NKR_NEEDRING); kring->nr_mode = NKR_NETMAP_ON; } } } return 0; } /* netmap_pipe_reg. * * There are two cases on registration (onoff==1) * * 1.a) state is * * usr1 --> e1 --> e2 * * and we are e1. Create the needed rings of the * other end. * * 1.b) state is * * usr1 --> e1 --> e2 <-- usr2 * * and we are e2. Drop the ref e1 is holding. * * There are two additional cases on unregister (onoff==0) * * 2.a) state is * * usr1 --> e1 --> e2 * * and we are e1. Nothing special to do, e2 will * be cleaned up by the destructor of e1. * * 2.b) state is * * usr1 --> e1 e2 <-- usr2 * * and we are either e1 or e2. Add a ref from the * other end. */ static int netmap_pipe_reg(struct netmap_adapter *na, int onoff) { struct netmap_pipe_adapter *pna = (struct netmap_pipe_adapter *)na; struct netmap_adapter *ona = &pna->peer->up; int error = 0; nm_prdis("%p: onoff %d", na, onoff); if (onoff) { error = netmap_pipe_reg_both(na, ona); if (error) { return error; } if (na->active_fds == 0) na->na_flags |= NAF_NETMAP_ON; } else { if (na->active_fds == 0) na->na_flags &= ~NAF_NETMAP_ON; netmap_krings_mode_commit(na, onoff); } if (na->active_fds) { nm_prdis("active_fds %d", na->active_fds); return 0; } if (pna->peer_ref) { nm_prdis("%p: case 1.a or 2.a, nothing to do", na); return 0; } if (onoff) { nm_prdis("%p: case 1.b, drop peer", na); pna->peer->peer_ref = 0; netmap_adapter_put(na); } else { nm_prdis("%p: case 2.b, grab peer", na); netmap_adapter_get(na); pna->peer->peer_ref = 1; } return error; } void netmap_pipe_krings_delete_both(struct netmap_adapter *na, struct netmap_adapter *ona) { struct netmap_adapter *sna; enum txrx t; int i; /* case 1) below */ nm_prdis("%p: case 1, deleting everything", na); /* To avoid double-frees we zero-out all the buffers in the kernel part * of each ring. The reason is this: If the user is behaving correctly, * all buffers are found in exactly one slot in the userspace part of * some ring. If the user is not behaving correctly, we cannot release * buffers cleanly anyway. In the latter case, the allocator will * return to a clean state only when all its users will close. */ sna = na; cleanup: for_rx_tx(t) { for (i = 0; i < nma_get_nrings(sna, t); i++) { struct netmap_kring *kring = NMR(sna, t)[i]; struct netmap_ring *ring = kring->ring; uint32_t j, lim = kring->nkr_num_slots - 1; nm_prdis("%s ring %p hwtail %u hwcur %u", kring->name, ring, kring->nr_hwtail, kring->nr_hwcur); if (ring == NULL) continue; if (kring->tx == NR_RX) ring->slot[kring->pipe_tail].buf_idx = 0; for (j = nm_next(kring->pipe_tail, lim); j != kring->nr_hwcur; j = nm_next(j, lim)) { nm_prdis("%s[%d] %u", kring->name, j, ring->slot[j].buf_idx); ring->slot[j].buf_idx = 0; } kring->nr_kflags &= ~(NKR_FAKERING | NKR_NEEDRING); } } if (sna != ona && ona->tx_rings) { sna = ona; goto cleanup; } netmap_mem_rings_delete(na); netmap_krings_delete(na); /* also zeroes tx_rings etc. */ if (ona->tx_rings == NULL) { /* already deleted, we must be on an * cleanup-after-error path */ return; } netmap_mem_rings_delete(ona); netmap_krings_delete(ona); } /* netmap_pipe_krings_delete. * * There are two cases: * * 1) state is * * usr1 --> e1 --> e2 * * and we are e1 (e2 is not registered, so krings_delete cannot be * called on it); * * 2) state is * * usr1 --> e1 e2 <-- usr2 * * and we are either e1 or e2. * * In the former case we have to also delete the krings of e2; * in the latter case we do nothing. */ static void netmap_pipe_krings_delete(struct netmap_adapter *na) { struct netmap_pipe_adapter *pna = (struct netmap_pipe_adapter *)na; struct netmap_adapter *ona; /* na of the other end */ if (!pna->peer_ref) { nm_prdis("%p: case 2, kept alive by peer", na); return; } ona = &pna->peer->up; netmap_pipe_krings_delete_both(na, ona); } static void netmap_pipe_dtor(struct netmap_adapter *na) { struct netmap_pipe_adapter *pna = (struct netmap_pipe_adapter *)na; nm_prdis("%p %p", na, pna->parent_ifp); if (pna->peer_ref) { nm_prdis("%p: clean up peer", na); pna->peer_ref = 0; netmap_adapter_put(&pna->peer->up); } if (pna->role == NM_PIPE_ROLE_MASTER) netmap_pipe_remove(pna->parent, pna); if (pna->parent_ifp) if_rele(pna->parent_ifp); netmap_adapter_put(pna->parent); pna->parent = NULL; } int netmap_get_pipe_na(struct nmreq_header *hdr, struct netmap_adapter **na, struct netmap_mem_d *nmd, int create) { struct nmreq_register *req = (struct nmreq_register *)(uintptr_t)hdr->nr_body; struct netmap_adapter *pna; /* parent adapter */ struct netmap_pipe_adapter *mna, *sna, *reqna; struct ifnet *ifp = NULL; const char *pipe_id = NULL; int role = 0; int error, retries = 0; char *cbra; /* Try to parse the pipe syntax 'xx{yy' or 'xx}yy'. */ cbra = strrchr(hdr->nr_name, '{'); if (cbra != NULL) { role = NM_PIPE_ROLE_MASTER; } else { cbra = strrchr(hdr->nr_name, '}'); if (cbra != NULL) { role = NM_PIPE_ROLE_SLAVE; } else { nm_prdis("not a pipe"); return 0; } } pipe_id = cbra + 1; if (*pipe_id == '\0' || cbra == hdr->nr_name) { /* Bracket is the last character, so pipe name is missing; * or bracket is the first character, so base port name * is missing. */ return EINVAL; } if (req->nr_mode != NR_REG_ALL_NIC && req->nr_mode != NR_REG_ONE_NIC) { /* We only accept modes involving hardware rings. */ return EINVAL; } /* first, try to find the parent adapter */ for (;;) { char nr_name_orig[NETMAP_REQ_IFNAMSIZ]; int create_error; /* Temporarily remove the pipe suffix. */ strlcpy(nr_name_orig, hdr->nr_name, sizeof(nr_name_orig)); *cbra = '\0'; error = netmap_get_na(hdr, &pna, &ifp, nmd, create); /* Restore the pipe suffix. */ strlcpy(hdr->nr_name, nr_name_orig, sizeof(hdr->nr_name)); if (!error) break; if (error != ENXIO || retries++) { nm_prdis("parent lookup failed: %d", error); return error; } nm_prdis("try to create a persistent vale port"); /* create a persistent vale port and try again */ *cbra = '\0'; NMG_UNLOCK(); create_error = netmap_vi_create(hdr, 1 /* autodelete */); NMG_LOCK(); strlcpy(hdr->nr_name, nr_name_orig, sizeof(hdr->nr_name)); if (create_error && create_error != EEXIST) { if (create_error != EOPNOTSUPP) { nm_prerr("failed to create a persistent vale port: %d", create_error); } return error; } } if (NETMAP_OWNED_BY_KERN(pna)) { nm_prdis("parent busy"); error = EBUSY; goto put_out; } /* next, lookup the pipe id in the parent list */ reqna = NULL; mna = netmap_pipe_find(pna, pipe_id); if (mna) { if (mna->role == role) { nm_prdis("found %s directly at %d", pipe_id, mna->parent_slot); reqna = mna; } else { nm_prdis("found %s indirectly at %d", pipe_id, mna->parent_slot); reqna = mna->peer; } /* the pipe we have found already holds a ref to the parent, * so we need to drop the one we got from netmap_get_na() */ netmap_unget_na(pna, ifp); goto found; } nm_prdis("pipe %s not found, create %d", pipe_id, create); if (!create) { error = ENODEV; goto put_out; } /* we create both master and slave. * The endpoint we were asked for holds a reference to * the other one. */ mna = nm_os_malloc(sizeof(*mna)); if (mna == NULL) { error = ENOMEM; goto put_out; } snprintf(mna->up.name, sizeof(mna->up.name), "%s{%s", pna->name, pipe_id); mna->role = NM_PIPE_ROLE_MASTER; mna->parent = pna; mna->parent_ifp = ifp; mna->up.nm_txsync = netmap_pipe_txsync; mna->up.nm_rxsync = netmap_pipe_rxsync; mna->up.nm_register = netmap_pipe_reg; mna->up.nm_dtor = netmap_pipe_dtor; mna->up.nm_krings_create = netmap_pipe_krings_create; mna->up.nm_krings_delete = netmap_pipe_krings_delete; mna->up.nm_mem = netmap_mem_get(pna->nm_mem); mna->up.na_flags |= NAF_MEM_OWNER; mna->up.na_lut = pna->na_lut; mna->up.num_tx_rings = req->nr_tx_rings; nm_bound_var(&mna->up.num_tx_rings, 1, 1, NM_PIPE_MAXRINGS, NULL); mna->up.num_rx_rings = req->nr_rx_rings; nm_bound_var(&mna->up.num_rx_rings, 1, 1, NM_PIPE_MAXRINGS, NULL); mna->up.num_tx_desc = req->nr_tx_slots; nm_bound_var(&mna->up.num_tx_desc, pna->num_tx_desc, 1, NM_PIPE_MAXSLOTS, NULL); mna->up.num_rx_desc = req->nr_rx_slots; nm_bound_var(&mna->up.num_rx_desc, pna->num_rx_desc, 1, NM_PIPE_MAXSLOTS, NULL); error = netmap_attach_common(&mna->up); if (error) goto free_mna; /* register the master with the parent */ error = netmap_pipe_add(pna, mna); if (error) goto free_mna; /* create the slave */ sna = nm_os_malloc(sizeof(*mna)); if (sna == NULL) { error = ENOMEM; goto unregister_mna; } /* most fields are the same, copy from master and then fix */ *sna = *mna; sna->up.nm_mem = netmap_mem_get(mna->up.nm_mem); /* swap the number of tx/rx rings and slots */ sna->up.num_tx_rings = mna->up.num_rx_rings; sna->up.num_tx_desc = mna->up.num_rx_desc; sna->up.num_rx_rings = mna->up.num_tx_rings; sna->up.num_rx_desc = mna->up.num_tx_desc; snprintf(sna->up.name, sizeof(sna->up.name), "%s}%s", pna->name, pipe_id); sna->role = NM_PIPE_ROLE_SLAVE; error = netmap_attach_common(&sna->up); if (error) goto free_sna; /* join the two endpoints */ mna->peer = sna; sna->peer = mna; /* we already have a reference to the parent, but we * need another one for the other endpoint we created */ netmap_adapter_get(pna); /* likewise for the ifp, if any */ if (ifp) if_ref(ifp); if (role == NM_PIPE_ROLE_MASTER) { reqna = mna; mna->peer_ref = 1; netmap_adapter_get(&sna->up); } else { reqna = sna; sna->peer_ref = 1; netmap_adapter_get(&mna->up); } nm_prdis("created master %p and slave %p", mna, sna); found: nm_prdis("pipe %s %s at %p", pipe_id, (reqna->role == NM_PIPE_ROLE_MASTER ? "master" : "slave"), reqna); *na = &reqna->up; netmap_adapter_get(*na); /* keep the reference to the parent. * It will be released by the req destructor */ return 0; free_sna: nm_os_free(sna); unregister_mna: netmap_pipe_remove(pna, mna); free_mna: nm_os_free(mna); put_out: netmap_unget_na(pna, ifp); return error; } #endif /* WITH_PIPES */