freebsd-dev/sys/dev/netmap/netmap_monitor.c
2018-05-18 03:38:17 +00:00

982 lines
26 KiB
C

/*
* Copyright (C) 2014-2016 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.
*/
/*
* $FreeBSD$
*
* Monitors
*
* netmap monitors can be used to do monitoring of network traffic
* on another adapter, when the latter adapter is working in netmap mode.
*
* Monitors offer to userspace the same interface as any other netmap port,
* with as many pairs of netmap rings as the monitored adapter.
* However, only the rx rings are actually used. Each monitor rx ring receives
* the traffic transiting on both the tx and rx corresponding rings in the
* monitored adapter. During registration, the user can choose if she wants
* to intercept tx only, rx only, or both tx and rx traffic.
*
* If the monitor is not able to cope with the stream of frames, excess traffic
* will be dropped.
*
* If the monitored adapter leaves netmap mode, the monitor has to be restarted.
*
* Monitors can be either zero-copy or copy-based.
*
* Copy monitors see the frames before they are consumed:
*
* - For tx traffic, this is when the application sends them, before they are
* passed down to the adapter.
*
* - For rx traffic, this is when they are received by the adapter, before
* they are sent up to the application, if any (note that, if no
* application is reading from a monitored ring, the ring will eventually
* fill up and traffic will stop).
*
* Zero-copy monitors only see the frames after they have been consumed:
*
* - For tx traffic, this is after the slots containing the frames have been
* marked as free. Note that this may happen at a considerably delay after
* frame transmission, since freeing of slots is often done lazily.
*
* - For rx traffic, this is after the consumer on the monitored adapter
* has released them. In most cases, the consumer is a userspace
* application which may have modified the frame contents.
*
* Several copy or zero-copy monitors may be active on any ring.
*
*/
#if defined(__FreeBSD__)
#include <sys/cdefs.h> /* prerequisite */
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/param.h> /* defines used in kernel.h */
#include <sys/kernel.h> /* types used in module initialization */
#include <sys/malloc.h>
#include <sys/poll.h>
#include <sys/lock.h>
#include <sys/rwlock.h>
#include <sys/selinfo.h>
#include <sys/sysctl.h>
#include <sys/socket.h> /* sockaddrs */
#include <net/if.h>
#include <net/if_var.h>
#include <machine/bus.h> /* bus_dmamap_* */
#include <sys/refcount.h>
#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 <net/netmap.h>
#include <dev/netmap/netmap_kern.h>
#include <dev/netmap/netmap_mem2.h>
#ifdef WITH_MONITOR
#define NM_MONITOR_MAXSLOTS 4096
/*
********************************************************************
* functions common to both kind of monitors
********************************************************************
*/
static int netmap_zmon_reg(struct netmap_adapter *, int);
static int
nm_is_zmon(struct netmap_adapter *na)
{
return na->nm_register == netmap_zmon_reg;
}
/* nm_sync callback for the monitor's own tx rings.
* This makes no sense and always returns error
*/
static int
netmap_monitor_txsync(struct netmap_kring *kring, int flags)
{
RD(1, "%s %x", kring->name, flags);
return EIO;
}
/* nm_sync callback for the monitor's own rx rings.
* Note that the lock in netmap_zmon_parent_sync only protects
* writers among themselves. Synchronization between writers
* (i.e., netmap_zmon_parent_txsync and netmap_zmon_parent_rxsync)
* and readers (i.e., netmap_zmon_rxsync) relies on memory barriers.
*/
static int
netmap_monitor_rxsync(struct netmap_kring *kring, int flags)
{
ND("%s %x", kring->name, flags);
kring->nr_hwcur = kring->rhead;
mb();
return 0;
}
/* nm_krings_create callbacks for monitors.
*/
static int
netmap_monitor_krings_create(struct netmap_adapter *na)
{
int error = netmap_krings_create(na, 0);
if (error)
return error;
/* override the host rings callbacks */
na->tx_rings[na->num_tx_rings]->nm_sync = netmap_monitor_txsync;
na->rx_rings[na->num_rx_rings]->nm_sync = netmap_monitor_rxsync;
return 0;
}
/* nm_krings_delete callback for monitors */
static void
netmap_monitor_krings_delete(struct netmap_adapter *na)
{
netmap_krings_delete(na);
}
static u_int
nm_txrx2flag(enum txrx t)
{
return (t == NR_RX ? NR_MONITOR_RX : NR_MONITOR_TX);
}
/* allocate the monitors array in the monitored kring */
static int
nm_monitor_alloc(struct netmap_kring *kring, u_int n)
{
size_t old_len, len;
struct netmap_kring **nm;
if (n <= kring->max_monitors)
/* we already have more entries that requested */
return 0;
old_len = sizeof(struct netmap_kring *)*kring->max_monitors;
len = sizeof(struct netmap_kring *) * n;
nm = nm_os_realloc(kring->monitors, len, old_len);
if (nm == NULL)
return ENOMEM;
kring->monitors = nm;
kring->max_monitors = n;
return 0;
}
/* deallocate the parent array in the parent adapter */
static void
nm_monitor_dealloc(struct netmap_kring *kring)
{
if (kring->monitors) {
if (kring->n_monitors > 0) {
D("freeing not empty monitor array for %s (%d dangling monitors)!", kring->name,
kring->n_monitors);
}
nm_os_free(kring->monitors);
kring->monitors = NULL;
kring->max_monitors = 0;
kring->n_monitors = 0;
}
}
/* returns 1 iff kring has no monitors */
static inline int
nm_monitor_none(struct netmap_kring *kring)
{
return kring->n_monitors == 0 &&
kring->zmon_list[NR_TX].next == NULL &&
kring->zmon_list[NR_RX].next == NULL;
}
/*
* monitors work by replacing the nm_sync() and possibly the
* nm_notify() callbacks in the monitored rings.
*/
static int netmap_zmon_parent_txsync(struct netmap_kring *, int);
static int netmap_zmon_parent_rxsync(struct netmap_kring *, int);
static int netmap_monitor_parent_txsync(struct netmap_kring *, int);
static int netmap_monitor_parent_rxsync(struct netmap_kring *, int);
static int netmap_monitor_parent_notify(struct netmap_kring *, int);
/* add the monitor mkring to the list of monitors of kring.
* If this is the first monitor, intercept the callbacks
*/
static int
netmap_monitor_add(struct netmap_kring *mkring, struct netmap_kring *kring, int zmon)
{
int error = NM_IRQ_COMPLETED;
enum txrx t = kring->tx;
struct netmap_zmon_list *z = &kring->zmon_list[t];
struct netmap_zmon_list *mz = &mkring->zmon_list[t];
/* a zero-copy monitor which is not the first in the list
* must monitor the previous monitor
*/
if (zmon && z->prev != NULL)
kring = z->prev;
/* synchronize with concurrently running nm_sync()s */
nm_kr_stop(kring, NM_KR_LOCKED);
if (nm_monitor_none(kring)) {
/* this is the first monitor, intercept callbacks */
ND("intercept callbacks on %s", kring->name);
kring->mon_sync = kring->nm_sync;
kring->mon_notify = kring->nm_notify;
if (kring->tx == NR_TX) {
kring->nm_sync = netmap_monitor_parent_txsync;
} else {
kring->nm_sync = netmap_monitor_parent_rxsync;
kring->nm_notify = netmap_monitor_parent_notify;
kring->mon_tail = kring->nr_hwtail;
}
}
if (zmon) {
/* append the zmon to the list */
struct netmap_monitor_adapter *mna =
(struct netmap_monitor_adapter *)mkring->na;
struct netmap_adapter *pna;
if (z->prev != NULL)
z->prev->zmon_list[t].next = mkring;
mz->prev = z->prev;
z->prev = mkring;
if (z->next == NULL)
z->next = mkring;
/* grap a reference to the previous netmap adapter
* in the chain (this may be the monitored port
* or another zero-copy monitor)
*/
pna = kring->na;
netmap_adapter_get(pna);
netmap_adapter_put(mna->priv.np_na);
mna->priv.np_na = pna;
} else {
/* make sure the monitor array exists and is big enough */
error = nm_monitor_alloc(kring, kring->n_monitors + 1);
if (error)
goto out;
kring->monitors[kring->n_monitors] = mkring;
mkring->mon_pos[kring->tx] = kring->n_monitors;
kring->n_monitors++;
}
out:
nm_kr_start(kring);
return error;
}
/* remove the monitor mkring from the list of monitors of kring.
* If this is the last monitor, restore the original callbacks
*/
static void
netmap_monitor_del(struct netmap_kring *mkring, struct netmap_kring *kring)
{
struct netmap_zmon_list *mz = &mkring->zmon_list[kring->tx];
int zmon = nm_is_zmon(mkring->na);
if (zmon && mz->prev != NULL)
kring = mz->prev;
/* synchronize with concurrently running nm_sync()s */
nm_kr_stop(kring, NM_KR_LOCKED);
if (zmon) {
/* remove the monitor from the list */
if (mz->prev != NULL)
mz->prev->zmon_list[kring->tx].next = mz->next;
else
kring->zmon_list[kring->tx].next = mz->next;
if (mz->next != NULL) {
mz->next->zmon_list[kring->tx].prev = mz->prev;
} else {
kring->zmon_list[kring->tx].prev = mz->prev;
}
} else {
/* this is a copy monitor */
uint32_t mon_pos = mkring->mon_pos[kring->tx];
kring->n_monitors--;
if (mon_pos != kring->n_monitors) {
kring->monitors[mon_pos] =
kring->monitors[kring->n_monitors];
kring->monitors[mon_pos]->mon_pos[kring->tx] = mon_pos;
}
kring->monitors[kring->n_monitors] = NULL;
if (kring->n_monitors == 0) {
nm_monitor_dealloc(kring);
}
}
if (nm_monitor_none(kring)) {
/* this was the last monitor, restore the callbacks */
ND("%s: restoring sync on %s: %p", mkring->name, kring->name,
kring->mon_sync);
kring->nm_sync = kring->mon_sync;
kring->mon_sync = NULL;
if (kring->tx == NR_RX) {
ND("%s: restoring notify on %s: %p",
mkring->name, kring->name, kring->mon_notify);
kring->nm_notify = kring->mon_notify;
kring->mon_notify = NULL;
}
}
nm_kr_start(kring);
}
/* This is called when the monitored adapter leaves netmap mode
* (see netmap_do_unregif).
* We need to notify the monitors that the monitored rings are gone.
* We do this by setting their mna->priv.np_na to NULL.
* Note that the rings are already stopped when this happens, so
* no monitor ring callback can be active.
*/
void
netmap_monitor_stop(struct netmap_adapter *na)
{
enum txrx t;
for_rx_tx(t) {
u_int i;
for (i = 0; i < nma_get_nrings(na, t) + 1; i++) {
struct netmap_kring *kring = NMR(na, t)[i];
struct netmap_kring *zkring;
u_int j;
for (j = 0; j < kring->n_monitors; j++) {
struct netmap_kring *mkring =
kring->monitors[j];
struct netmap_monitor_adapter *mna =
(struct netmap_monitor_adapter *)mkring->na;
/* forget about this adapter */
if (mna->priv.np_na != NULL) {
netmap_adapter_put(mna->priv.np_na);
mna->priv.np_na = NULL;
}
}
zkring = kring->zmon_list[kring->tx].next;
if (zkring != NULL) {
struct netmap_monitor_adapter *next =
(struct netmap_monitor_adapter *)zkring->na;
struct netmap_monitor_adapter *this =
(struct netmap_monitor_adapter *)na;
struct netmap_adapter *pna = this->priv.np_na;
/* let the next monitor forget about us */
if (next->priv.np_na != NULL) {
netmap_adapter_put(next->priv.np_na);
}
if (pna != NULL && nm_is_zmon(na)) {
/* we are a monitor ourselves and we may
* need to pass down the reference to
* the previous adapter in the chain
*/
netmap_adapter_get(pna);
next->priv.np_na = pna;
continue;
}
next->priv.np_na = NULL;
}
}
}
}
/* common functions for the nm_register() callbacks of both kind of
* monitors.
*/
static int
netmap_monitor_reg_common(struct netmap_adapter *na, int onoff, int zmon)
{
struct netmap_monitor_adapter *mna =
(struct netmap_monitor_adapter *)na;
struct netmap_priv_d *priv = &mna->priv;
struct netmap_adapter *pna = priv->np_na;
struct netmap_kring *kring, *mkring;
int i;
enum txrx t, s;
ND("%p: onoff %d", na, onoff);
if (onoff) {
if (pna == NULL) {
/* parent left netmap mode, fatal */
D("%s: internal error", na->name);
return ENXIO;
}
for_rx_tx(t) {
for (i = 0; i < nma_get_nrings(na, t) + 1; i++) {
mkring = NMR(na, t)[i];
if (!nm_kring_pending_on(mkring))
continue;
mkring->nr_mode = NKR_NETMAP_ON;
if (t == NR_TX)
continue;
for_rx_tx(s) {
if (i > nma_get_nrings(pna, s))
continue;
if (mna->flags & nm_txrx2flag(s)) {
kring = NMR(pna, s)[i];
netmap_monitor_add(mkring, kring, zmon);
}
}
}
}
na->na_flags |= NAF_NETMAP_ON;
} else {
if (na->active_fds == 0)
na->na_flags &= ~NAF_NETMAP_ON;
for_rx_tx(t) {
for (i = 0; i < nma_get_nrings(na, t) + 1; i++) {
mkring = NMR(na, t)[i];
if (!nm_kring_pending_off(mkring))
continue;
mkring->nr_mode = NKR_NETMAP_OFF;
if (t == NR_TX)
continue;
/* we cannot access the parent krings if the parent
* has left netmap mode. This is signaled by a NULL
* pna pointer
*/
if (pna == NULL)
continue;
for_rx_tx(s) {
if (i > nma_get_nrings(pna, s))
continue;
if (mna->flags & nm_txrx2flag(s)) {
kring = NMR(pna, s)[i];
netmap_monitor_del(mkring, kring);
}
}
}
}
}
return 0;
}
/*
****************************************************************
* functions specific for zero-copy monitors
****************************************************************
*/
/*
* Common function for both zero-copy tx and rx nm_sync()
* callbacks
*/
static int
netmap_zmon_parent_sync(struct netmap_kring *kring, int flags, enum txrx tx)
{
struct netmap_kring *mkring = kring->zmon_list[tx].next;
struct netmap_ring *ring = kring->ring, *mring;
int error = 0;
int rel_slots, free_slots, busy, sent = 0;
u_int beg, end, i;
u_int lim = kring->nkr_num_slots - 1,
mlim; // = mkring->nkr_num_slots - 1;
if (mkring == NULL) {
RD(5, "NULL monitor on %s", kring->name);
return 0;
}
mring = mkring->ring;
mlim = mkring->nkr_num_slots - 1;
/* get the relased slots (rel_slots) */
if (tx == NR_TX) {
beg = kring->nr_hwtail + 1;
error = kring->mon_sync(kring, flags);
if (error)
return error;
end = kring->nr_hwtail + 1;
} else { /* NR_RX */
beg = kring->nr_hwcur;
end = kring->rhead;
}
rel_slots = end - beg;
if (rel_slots < 0)
rel_slots += kring->nkr_num_slots;
if (!rel_slots) {
/* no released slots, but we still need
* to call rxsync if this is a rx ring
*/
goto out_rxsync;
}
/* we need to lock the monitor receive ring, since it
* is the target of bot tx and rx traffic from the monitored
* adapter
*/
mtx_lock(&mkring->q_lock);
/* get the free slots available on the monitor ring */
i = mkring->nr_hwtail;
busy = i - mkring->nr_hwcur;
if (busy < 0)
busy += mkring->nkr_num_slots;
free_slots = mlim - busy;
if (!free_slots)
goto out;
/* swap min(free_slots, rel_slots) slots */
if (free_slots < rel_slots) {
beg += (rel_slots - free_slots);
rel_slots = free_slots;
}
if (unlikely(beg >= kring->nkr_num_slots))
beg -= kring->nkr_num_slots;
sent = rel_slots;
for ( ; rel_slots; rel_slots--) {
struct netmap_slot *s = &ring->slot[beg];
struct netmap_slot *ms = &mring->slot[i];
uint32_t tmp;
tmp = ms->buf_idx;
ms->buf_idx = s->buf_idx;
s->buf_idx = tmp;
ND(5, "beg %d buf_idx %d", beg, tmp);
tmp = ms->len;
ms->len = s->len;
s->len = tmp;
s->flags |= NS_BUF_CHANGED;
beg = nm_next(beg, lim);
i = nm_next(i, mlim);
}
mb();
mkring->nr_hwtail = i;
out:
mtx_unlock(&mkring->q_lock);
if (sent) {
/* notify the new frames to the monitor */
mkring->nm_notify(mkring, 0);
}
out_rxsync:
if (tx == NR_RX)
error = kring->mon_sync(kring, flags);
return error;
}
/* callback used to replace the nm_sync callback in the monitored tx rings */
static int
netmap_zmon_parent_txsync(struct netmap_kring *kring, int flags)
{
return netmap_zmon_parent_sync(kring, flags, NR_TX);
}
/* callback used to replace the nm_sync callback in the monitored rx rings */
static int
netmap_zmon_parent_rxsync(struct netmap_kring *kring, int flags)
{
return netmap_zmon_parent_sync(kring, flags, NR_RX);
}
static int
netmap_zmon_reg(struct netmap_adapter *na, int onoff)
{
return netmap_monitor_reg_common(na, onoff, 1 /* zcopy */);
}
/* nm_dtor callback for monitors */
static void
netmap_zmon_dtor(struct netmap_adapter *na)
{
struct netmap_monitor_adapter *mna =
(struct netmap_monitor_adapter *)na;
struct netmap_priv_d *priv = &mna->priv;
struct netmap_adapter *pna = priv->np_na;
netmap_adapter_put(pna);
}
/*
****************************************************************
* functions specific for copy monitors
****************************************************************
*/
static void
netmap_monitor_parent_sync(struct netmap_kring *kring, u_int first_new, int new_slots)
{
u_int j;
for (j = 0; j < kring->n_monitors; j++) {
struct netmap_kring *mkring = kring->monitors[j];
u_int i, mlim, beg;
int free_slots, busy, sent = 0, m;
u_int lim = kring->nkr_num_slots - 1;
struct netmap_ring *ring = kring->ring, *mring = mkring->ring;
u_int max_len = NETMAP_BUF_SIZE(mkring->na);
mlim = mkring->nkr_num_slots - 1;
/* we need to lock the monitor receive ring, since it
* is the target of bot tx and rx traffic from the monitored
* adapter
*/
mtx_lock(&mkring->q_lock);
/* get the free slots available on the monitor ring */
i = mkring->nr_hwtail;
busy = i - mkring->nr_hwcur;
if (busy < 0)
busy += mkring->nkr_num_slots;
free_slots = mlim - busy;
if (!free_slots)
goto out;
/* copy min(free_slots, new_slots) slots */
m = new_slots;
beg = first_new;
if (free_slots < m) {
beg += (m - free_slots);
if (beg >= kring->nkr_num_slots)
beg -= kring->nkr_num_slots;
m = free_slots;
}
for ( ; m; m--) {
struct netmap_slot *s = &ring->slot[beg];
struct netmap_slot *ms = &mring->slot[i];
u_int copy_len = s->len;
char *src = NMB(kring->na, s),
*dst = NMB(mkring->na, ms);
if (unlikely(copy_len > max_len)) {
RD(5, "%s->%s: truncating %d to %d", kring->name,
mkring->name, copy_len, max_len);
copy_len = max_len;
}
memcpy(dst, src, copy_len);
ms->len = copy_len;
sent++;
beg = nm_next(beg, lim);
i = nm_next(i, mlim);
}
mb();
mkring->nr_hwtail = i;
out:
mtx_unlock(&mkring->q_lock);
if (sent) {
/* notify the new frames to the monitor */
mkring->nm_notify(mkring, 0);
}
}
}
/* callback used to replace the nm_sync callback in the monitored tx rings */
static int
netmap_monitor_parent_txsync(struct netmap_kring *kring, int flags)
{
u_int first_new;
int new_slots;
/* get the new slots */
if (kring->n_monitors > 0) {
first_new = kring->nr_hwcur;
new_slots = kring->rhead - first_new;
if (new_slots < 0)
new_slots += kring->nkr_num_slots;
if (new_slots)
netmap_monitor_parent_sync(kring, first_new, new_slots);
}
if (kring->zmon_list[NR_TX].next != NULL) {
return netmap_zmon_parent_txsync(kring, flags);
}
return kring->mon_sync(kring, flags);
}
/* callback used to replace the nm_sync callback in the monitored rx rings */
static int
netmap_monitor_parent_rxsync(struct netmap_kring *kring, int flags)
{
u_int first_new;
int new_slots, error;
/* get the new slots */
if (kring->zmon_list[NR_RX].next != NULL) {
error = netmap_zmon_parent_rxsync(kring, flags);
} else {
error = kring->mon_sync(kring, flags);
}
if (error)
return error;
if (kring->n_monitors > 0) {
first_new = kring->mon_tail;
new_slots = kring->nr_hwtail - first_new;
if (new_slots < 0)
new_slots += kring->nkr_num_slots;
if (new_slots)
netmap_monitor_parent_sync(kring, first_new, new_slots);
kring->mon_tail = kring->nr_hwtail;
}
return 0;
}
/* callback used to replace the nm_notify() callback in the monitored rx rings */
static int
netmap_monitor_parent_notify(struct netmap_kring *kring, int flags)
{
int (*notify)(struct netmap_kring*, int);
ND(5, "%s %x", kring->name, flags);
/* ?xsync callbacks have tryget called by their callers
* (NIOCREGIF and poll()), but here we have to call it
* by ourself
*/
if (nm_kr_tryget(kring, 0, NULL)) {
/* in all cases, just skip the sync */
return NM_IRQ_COMPLETED;
}
if (kring->n_monitors > 0) {
netmap_monitor_parent_rxsync(kring, NAF_FORCE_READ);
}
if (nm_monitor_none(kring)) {
/* we are no longer monitoring this ring, so both
* mon_sync and mon_notify are NULL
*/
notify = kring->nm_notify;
} else {
notify = kring->mon_notify;
}
nm_kr_put(kring);
return notify(kring, flags);
}
static int
netmap_monitor_reg(struct netmap_adapter *na, int onoff)
{
return netmap_monitor_reg_common(na, onoff, 0 /* no zcopy */);
}
static void
netmap_monitor_dtor(struct netmap_adapter *na)
{
struct netmap_monitor_adapter *mna =
(struct netmap_monitor_adapter *)na;
struct netmap_priv_d *priv = &mna->priv;
struct netmap_adapter *pna = priv->np_na;
netmap_adapter_put(pna);
}
/* check if req is a request for a monitor adapter that we can satisfy */
int
netmap_get_monitor_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 nmreq_register preq;
struct netmap_adapter *pna; /* parent adapter */
struct netmap_monitor_adapter *mna;
struct ifnet *ifp = NULL;
int error;
int zcopy = (req->nr_flags & NR_ZCOPY_MON);
char monsuff[10] = "";
if (zcopy) {
req->nr_flags |= (NR_MONITOR_TX | NR_MONITOR_RX);
}
if ((req->nr_flags & (NR_MONITOR_TX | NR_MONITOR_RX)) == 0) {
ND("not a monitor");
return 0;
}
/* this is a request for a monitor adapter */
ND("flags %lx", req->nr_flags);
/* First, try to find the adapter that we want to monitor.
* We use the same req, after we have turned off the monitor flags.
* In this way we can potentially monitor everything netmap understands,
* except other monitors.
*/
memcpy(&preq, req, sizeof(preq));
preq.nr_flags &= ~(NR_MONITOR_TX | NR_MONITOR_RX | NR_ZCOPY_MON);
hdr->nr_body = (uintptr_t)&preq;
error = netmap_get_na(hdr, &pna, &ifp, nmd, create);
hdr->nr_body = (uintptr_t)req;
if (error) {
D("parent lookup failed: %d", error);
return error;
}
ND("found parent: %s", pna->name);
if (!nm_netmap_on(pna)) {
/* parent not in netmap mode */
/* XXX we can wait for the parent to enter netmap mode,
* by intercepting its nm_register callback (2014-03-16)
*/
D("%s not in netmap mode", pna->name);
error = EINVAL;
goto put_out;
}
mna = nm_os_malloc(sizeof(*mna));
if (mna == NULL) {
D("memory error");
error = ENOMEM;
goto put_out;
}
mna->priv.np_na = pna;
/* grab all the rings we need in the parent */
error = netmap_interp_ringid(&mna->priv, req->nr_mode, req->nr_ringid,
req->nr_flags);
if (error) {
D("ringid error");
goto free_out;
}
if (mna->priv.np_qlast[NR_TX] - mna->priv.np_qfirst[NR_TX] == 1) {
snprintf(monsuff, 10, "-%d", mna->priv.np_qfirst[NR_TX]);
}
snprintf(mna->up.name, sizeof(mna->up.name), "%s%s/%s%s%s", pna->name,
monsuff,
zcopy ? "z" : "",
(req->nr_flags & NR_MONITOR_RX) ? "r" : "",
(req->nr_flags & NR_MONITOR_TX) ? "t" : "");
/* the monitor supports the host rings iff the parent does */
mna->up.na_flags |= (pna->na_flags & NAF_HOST_RINGS);
/* a do-nothing txsync: monitors cannot be used to inject packets */
mna->up.nm_txsync = netmap_monitor_txsync;
mna->up.nm_rxsync = netmap_monitor_rxsync;
mna->up.nm_krings_create = netmap_monitor_krings_create;
mna->up.nm_krings_delete = netmap_monitor_krings_delete;
mna->up.num_tx_rings = 1; // XXX what should we do here with chained zmons?
/* we set the number of our rx_rings to be max(num_rx_rings, num_rx_rings)
* in the parent
*/
mna->up.num_rx_rings = pna->num_rx_rings;
if (pna->num_tx_rings > pna->num_rx_rings)
mna->up.num_rx_rings = pna->num_tx_rings;
/* by default, the number of slots is the same as in
* the parent rings, but the user may ask for a different
* number
*/
mna->up.num_tx_desc = req->nr_tx_slots;
nm_bound_var(&mna->up.num_tx_desc, pna->num_tx_desc,
1, NM_MONITOR_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_MONITOR_MAXSLOTS, NULL);
if (zcopy) {
mna->up.nm_register = netmap_zmon_reg;
mna->up.nm_dtor = netmap_zmon_dtor;
/* to have zero copy, we need to use the same memory allocator
* as the monitored port
*/
mna->up.nm_mem = netmap_mem_get(pna->nm_mem);
/* and the allocator cannot be changed */
mna->up.na_flags |= NAF_MEM_OWNER;
} else {
mna->up.nm_register = netmap_monitor_reg;
mna->up.nm_dtor = netmap_monitor_dtor;
mna->up.nm_mem = netmap_mem_private_new(
mna->up.num_tx_rings,
mna->up.num_tx_desc,
mna->up.num_rx_rings,
mna->up.num_rx_desc,
0, /* extra bufs */
0, /* pipes */
&error);
if (mna->up.nm_mem == NULL)
goto put_out;
}
error = netmap_attach_common(&mna->up);
if (error) {
D("attach_common error");
goto mem_put_out;
}
/* remember the traffic directions we have to monitor */
mna->flags = (req->nr_flags & (NR_MONITOR_TX | NR_MONITOR_RX | NR_ZCOPY_MON));
*na = &mna->up;
netmap_adapter_get(*na);
/* keep the reference to the parent */
ND("monitor ok");
/* drop the reference to the ifp, if any */
if (ifp)
if_rele(ifp);
return 0;
mem_put_out:
netmap_mem_put(mna->up.nm_mem);
free_out:
nm_os_free(mna);
put_out:
netmap_unget_na(pna, ifp);
return error;
}
#endif /* WITH_MONITOR */