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netmap.c
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3557 lines (3155 loc) · 98.7 KB
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/*
* Copyright (C) 2011-2014 Matteo Landi, Luigi Rizzo. 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.
*/
/*
* $FreeBSD$
*
* This module supports memory mapped access to network devices,
* see netmap(4).
*
* The module uses a large, memory pool allocated by the kernel
* and accessible as mmapped memory by multiple userspace threads/processes.
* The memory pool contains packet buffers and "netmap rings",
* i.e. user-accessible copies of the interface's queues.
*
* Access to the network card works like this:
* 1. a process/thread issues one or more open() on /dev/netmap, to create
* select()able file descriptor on which events are reported.
* 2. on each descriptor, the process issues an ioctl() to identify
* the interface that should report events to the file descriptor.
* 3. on each descriptor, the process issues an mmap() request to
* map the shared memory region within the process' address space.
* The list of interesting queues is indicated by a location in
* the shared memory region.
* 4. using the functions in the netmap(4) userspace API, a process
* can look up the occupation state of a queue, access memory buffers,
* and retrieve received packets or enqueue packets to transmit.
* 5. using some ioctl()s the process can synchronize the userspace view
* of the queue with the actual status in the kernel. This includes both
* receiving the notification of new packets, and transmitting new
* packets on the output interface.
* 6. select() or poll() can be used to wait for events on individual
* transmit or receive queues (or all queues for a given interface).
*
SYNCHRONIZATION (USER)
The netmap rings and data structures may be shared among multiple
user threads or even independent processes.
Any synchronization among those threads/processes is delegated
to the threads themselves. Only one thread at a time can be in
a system call on the same netmap ring. The OS does not enforce
this and only guarantees against system crashes in case of
invalid usage.
LOCKING (INTERNAL)
Within the kernel, access to the netmap rings is protected as follows:
- a spinlock on each ring, to handle producer/consumer races on
RX rings attached to the host stack (against multiple host
threads writing from the host stack to the same ring),
and on 'destination' rings attached to a VALE switch
(i.e. RX rings in VALE ports, and TX rings in NIC/host ports)
protecting multiple active senders for the same destination)
- an atomic variable to guarantee that there is at most one
instance of *_*xsync() on the ring at any time.
For rings connected to user file
descriptors, an atomic_test_and_set() protects this, and the
lock on the ring is not actually used.
For NIC RX rings connected to a VALE switch, an atomic_test_and_set()
is also used to prevent multiple executions (the driver might indeed
already guarantee this).
For NIC TX rings connected to a VALE switch, the lock arbitrates
access to the queue (both when allocating buffers and when pushing
them out).
- *xsync() should be protected against initializations of the card.
On FreeBSD most devices have the reset routine protected by
a RING lock (ixgbe, igb, em) or core lock (re). lem is missing
the RING protection on rx_reset(), this should be added.
On linux there is an external lock on the tx path, which probably
also arbitrates access to the reset routine. XXX to be revised
- a per-interface core_lock protecting access from the host stack
while interfaces may be detached from netmap mode.
XXX there should be no need for this lock if we detach the interfaces
only while they are down.
--- VALE SWITCH ---
NMG_LOCK() serializes all modifications to switches and ports.
A switch cannot be deleted until all ports are gone.
For each switch, an SX lock (RWlock on linux) protects
deletion of ports. When configuring or deleting a new port, the
lock is acquired in exclusive mode (after holding NMG_LOCK).
When forwarding, the lock is acquired in shared mode (without NMG_LOCK).
The lock is held throughout the entire forwarding cycle,
during which the thread may incur in a page fault.
Hence it is important that sleepable shared locks are used.
On the rx ring, the per-port lock is grabbed initially to reserve
a number of slot in the ring, then the lock is released,
packets are copied from source to destination, and then
the lock is acquired again and the receive ring is updated.
(A similar thing is done on the tx ring for NIC and host stack
ports attached to the switch)
*/
/* --- internals ----
*
* Roadmap to the code that implements the above.
*
* > 1. a process/thread issues one or more open() on /dev/netmap, to create
* > select()able file descriptor on which events are reported.
*
* Internally, we allocate a netmap_priv_d structure, that will be
* initialized on ioctl(NIOCREGIF). There is one netmap_priv_d
* structure for each open().
*
* os-specific:
* FreeBSD: see netmap_open() (netmap_freebsd.c)
* linux: see linux_netmap_open() (netmap_linux.c)
*
* > 2. on each descriptor, the process issues an ioctl() to identify
* > the interface that should report events to the file descriptor.
*
* Implemented by netmap_ioctl(), NIOCREGIF case, with nmr->nr_cmd==0.
* Most important things happen in netmap_get_na() and
* netmap_do_regif(), called from there. Additional details can be
* found in the comments above those functions.
*
* In all cases, this action creates/takes-a-reference-to a
* netmap_*_adapter describing the port, and allocates a netmap_if
* and all necessary netmap rings, filling them with netmap buffers.
*
* In this phase, the sync callbacks for each ring are set (these are used
* in steps 5 and 6 below). The callbacks depend on the type of adapter.
* The adapter creation/initialization code puts them in the
* netmap_adapter (fields na->nm_txsync and na->nm_rxsync). Then, they
* are copied from there to the netmap_kring's during netmap_do_regif(), by
* the nm_krings_create() callback. All the nm_krings_create callbacks
* actually call netmap_krings_create() to perform this and the other
* common stuff. netmap_krings_create() also takes care of the host rings,
* if needed, by setting their sync callbacks appropriately.
*
* Additional actions depend on the kind of netmap_adapter that has been
* registered:
*
* - netmap_hw_adapter: [netmap.c]
* This is a system netdev/ifp with native netmap support.
* The ifp is detached from the host stack by redirecting:
* - transmissions (from the network stack) to netmap_transmit()
* - receive notifications to the nm_notify() callback for
* this adapter. The callback is normally netmap_notify(), unless
* the ifp is attached to a bridge using bwrap, in which case it
* is netmap_bwrap_intr_notify().
*
* - netmap_generic_adapter: [netmap_generic.c]
* A system netdev/ifp without native netmap support.
*
* (the decision about native/non native support is taken in
* netmap_get_hw_na(), called by netmap_get_na())
*
* - netmap_vp_adapter [netmap_vale.c]
* Returned by netmap_get_bdg_na().
* This is a persistent or ephemeral VALE port. Ephemeral ports
* are created on the fly if they don't already exist, and are
* always attached to a bridge.
* Persistent VALE ports must must be created separately, and i
* then attached like normal NICs. The NIOCREGIF we are examining
* will find them only if they had previosly been created and
* attached (see VALE_CTL below).
*
* - netmap_pipe_adapter [netmap_pipe.c]
* Returned by netmap_get_pipe_na().
* Both pipe ends are created, if they didn't already exist.
*
* - netmap_monitor_adapter [netmap_monitor.c]
* Returned by netmap_get_monitor_na().
* If successful, the nm_sync callbacks of the monitored adapter
* will be intercepted by the returned monitor.
*
* - netmap_bwrap_adapter [netmap_vale.c]
* Cannot be obtained in this way, see VALE_CTL below
*
*
* os-specific:
* linux: we first go through linux_netmap_ioctl() to
* adapt the FreeBSD interface to the linux one.
*
*
* > 3. on each descriptor, the process issues an mmap() request to
* > map the shared memory region within the process' address space.
* > The list of interesting queues is indicated by a location in
* > the shared memory region.
*
* os-specific:
* FreeBSD: netmap_mmap_single (netmap_freebsd.c).
* linux: linux_netmap_mmap (netmap_linux.c).
*
* > 4. using the functions in the netmap(4) userspace API, a process
* > can look up the occupation state of a queue, access memory buffers,
* > and retrieve received packets or enqueue packets to transmit.
*
* these actions do not involve the kernel.
*
* > 5. using some ioctl()s the process can synchronize the userspace view
* > of the queue with the actual status in the kernel. This includes both
* > receiving the notification of new packets, and transmitting new
* > packets on the output interface.
*
* These are implemented in netmap_ioctl(), NIOCTXSYNC and NIOCRXSYNC
* cases. They invoke the nm_sync callbacks on the netmap_kring
* structures, as initialized in step 2 and maybe later modified
* by a monitor. Monitors, however, will always call the original
* callback before doing anything else.
*
*
* > 6. select() or poll() can be used to wait for events on individual
* > transmit or receive queues (or all queues for a given interface).
*
* Implemented in netmap_poll(). This will call the same nm_sync()
* callbacks as in step 5 above.
*
* os-specific:
* linux: we first go through linux_netmap_poll() to adapt
* the FreeBSD interface to the linux one.
*
*
* ---- VALE_CTL -----
*
* VALE switches are controlled by issuing a NIOCREGIF with a non-null
* nr_cmd in the nmreq structure. These subcommands are handled by
* netmap_bdg_ctl() in netmap_vale.c. Persistent VALE ports are created
* and destroyed by issuing the NETMAP_BDG_NEWIF and NETMAP_BDG_DELIF
* subcommands, respectively.
*
* Any network interface known to the system (including a persistent VALE
* port) can be attached to a VALE switch by issuing the
* NETMAP_BDG_ATTACH subcommand. After the attachment, persistent VALE ports
* look exactly like ephemeral VALE ports (as created in step 2 above). The
* attachment of other interfaces, instead, requires the creation of a
* netmap_bwrap_adapter. Moreover, the attached interface must be put in
* netmap mode. This may require the creation of a netmap_generic_adapter if
* we have no native support for the interface, or if generic adapters have
* been forced by sysctl.
*
* Both persistent VALE ports and bwraps are handled by netmap_get_bdg_na(),
* called by nm_bdg_ctl_attach(), and discriminated by the nm_bdg_attach()
* callback. In the case of the bwrap, the callback creates the
* netmap_bwrap_adapter. The initialization of the bwrap is then
* completed by calling netmap_do_regif() on it, in the nm_bdg_ctl()
* callback (netmap_bwrap_bdg_ctl in netmap_vale.c).
* A generic adapter for the wrapped ifp will be created if needed, when
* netmap_get_bdg_na() calls netmap_get_hw_na().
*
*
* ---- DATAPATHS -----
*
* -= SYSTEM DEVICE WITH NATIVE SUPPORT =-
*
* na == NA(ifp) == netmap_hw_adapter created in DEVICE_netmap_attach()
*
* - tx from netmap userspace:
* concurrently:
* 1) ioctl(NIOCTXSYNC)/netmap_poll() in process context
* kring->nm_sync() == DEVICE_netmap_txsync()
* 2) device interrupt handler
* na->nm_notify() == netmap_notify()
* - rx from netmap userspace:
* concurrently:
* 1) ioctl(NIOCRXSYNC)/netmap_poll() in process context
* kring->nm_sync() == DEVICE_netmap_rxsync()
* 2) device interrupt handler
* na->nm_notify() == netmap_notify()
* - rx from host stack
* concurrently:
* 1) host stack
* netmap_transmit()
* na->nm_notify == netmap_notify()
* 2) ioctl(NIOCRXSYNC)/netmap_poll() in process context
* kring->nm_sync() == netmap_rxsync_from_host
* netmap_rxsync_from_host(na, NULL, NULL)
* - tx to host stack
* ioctl(NIOCTXSYNC)/netmap_poll() in process context
* kring->nm_sync() == netmap_txsync_to_host
* netmap_txsync_to_host(na)
* nm_os_send_up()
* FreeBSD: na->if_input() == ether_input()
* linux: netif_rx() with NM_MAGIC_PRIORITY_RX
*
*
* -= SYSTEM DEVICE WITH GENERIC SUPPORT =-
*
* na == NA(ifp) == generic_netmap_adapter created in generic_netmap_attach()
*
* - tx from netmap userspace:
* concurrently:
* 1) ioctl(NIOCTXSYNC)/netmap_poll() in process context
* kring->nm_sync() == generic_netmap_txsync()
* nm_os_generic_xmit_frame()
* linux: dev_queue_xmit() with NM_MAGIC_PRIORITY_TX
* ifp->ndo_start_xmit == generic_ndo_start_xmit()
* gna->save_start_xmit == orig. dev. start_xmit
* FreeBSD: na->if_transmit() == orig. dev if_transmit
* 2) generic_mbuf_destructor()
* na->nm_notify() == netmap_notify()
* - rx from netmap userspace:
* 1) ioctl(NIOCRXSYNC)/netmap_poll() in process context
* kring->nm_sync() == generic_netmap_rxsync()
* mbq_safe_dequeue()
* 2) device driver
* generic_rx_handler()
* mbq_safe_enqueue()
* na->nm_notify() == netmap_notify()
* - rx from host stack
* FreeBSD: same as native
* Linux: same as native except:
* 1) host stack
* dev_queue_xmit() without NM_MAGIC_PRIORITY_TX
* ifp->ndo_start_xmit == generic_ndo_start_xmit()
* netmap_transmit()
* na->nm_notify() == netmap_notify()
* - tx to host stack (same as native):
*
*
* -= VALE =-
*
* INCOMING:
*
* - VALE ports:
* ioctl(NIOCTXSYNC)/netmap_poll() in process context
* kring->nm_sync() == netmap_vp_txsync()
*
* - system device with native support:
* from cable:
* interrupt
* na->nm_notify() == netmap_bwrap_intr_notify(ring_nr != host ring)
* kring->nm_sync() == DEVICE_netmap_rxsync()
* netmap_vp_txsync()
* kring->nm_sync() == DEVICE_netmap_rxsync()
* from host stack:
* netmap_transmit()
* na->nm_notify() == netmap_bwrap_intr_notify(ring_nr == host ring)
* kring->nm_sync() == netmap_rxsync_from_host()
* netmap_vp_txsync()
*
* - system device with generic support:
* from device driver:
* generic_rx_handler()
* na->nm_notify() == netmap_bwrap_intr_notify(ring_nr != host ring)
* kring->nm_sync() == generic_netmap_rxsync()
* netmap_vp_txsync()
* kring->nm_sync() == generic_netmap_rxsync()
* from host stack:
* netmap_transmit()
* na->nm_notify() == netmap_bwrap_intr_notify(ring_nr == host ring)
* kring->nm_sync() == netmap_rxsync_from_host()
* netmap_vp_txsync()
*
* (all cases) --> nm_bdg_flush()
* dest_na->nm_notify() == (see below)
*
* OUTGOING:
*
* - VALE ports:
* concurrently:
* 1) ioctlNIOCRXSYNC)/netmap_poll() in process context
* kring->nm_sync() == netmap_vp_rxsync()
* 2) from nm_bdg_flush()
* na->nm_notify() == netmap_notify()
*
* - system device with native support:
* to cable:
* na->nm_notify() == netmap_bwrap_notify()
* netmap_vp_rxsync()
* kring->nm_sync() == DEVICE_netmap_txsync()
* netmap_vp_rxsync()
* to host stack:
* netmap_vp_rxsync()
* kring->nm_sync() == netmap_txsync_to_host
* netmap_vp_rxsync_locked()
*
* - system device with generic adapter:
* to device driver:
* na->nm_notify() == netmap_bwrap_notify()
* netmap_vp_rxsync()
* kring->nm_sync() == generic_netmap_txsync()
* netmap_vp_rxsync()
* to host stack:
* netmap_vp_rxsync()
* kring->nm_sync() == netmap_txsync_to_host
* netmap_vp_rxsync()
*
*/
/*
* OS-specific code that is used only within this file.
* Other OS-specific code that must be accessed by drivers
* is present in netmap_kern.h
*/
#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/conf.h> /* cdevsw struct, UID, GID */
#include <sys/filio.h> /* FIONBIO */
#include <sys/sockio.h>
#include <sys/socketvar.h> /* struct socket */
#include <sys/malloc.h>
#include <sys/poll.h>
#include <sys/rwlock.h>
#include <sys/socket.h> /* sockaddrs */
#include <sys/selinfo.h>
#include <sys/sysctl.h>
#include <sys/jail.h>
#include <net/vnet.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/bpf.h> /* BIOCIMMEDIATE */
#include <machine/bus.h> /* bus_dmamap_* */
#include <sys/endian.h>
#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>
/* user-controlled variables */
int netmap_verbose;
static int netmap_no_timestamp; /* don't timestamp on rxsync */
int netmap_mitigate = 1;
int netmap_no_pendintr = 1;
int netmap_txsync_retry = 2;
int netmap_adaptive_io = 0;
int netmap_flags = 0; /* debug flags */
static int netmap_fwd = 0; /* force transparent mode */
#ifdef WITH_NMCONF
int nm_conf_flat_mode = 0;
#endif
/*
* netmap_admode selects the netmap mode to use.
* Invalid values are reset to NETMAP_ADMODE_BEST
*/
enum { NETMAP_ADMODE_BEST = 0, /* use native, fallback to generic */
NETMAP_ADMODE_NATIVE, /* either native or none */
NETMAP_ADMODE_GENERIC, /* force generic */
NETMAP_ADMODE_LAST };
static int netmap_admode = NETMAP_ADMODE_BEST;
/* netmap_generic_mit controls mitigation of RX notifications for
* the generic netmap adapter. The value is a time interval in
* nanoseconds. */
int netmap_generic_mit = 100*1000;
/* We use by default netmap-aware qdiscs with generic netmap adapters,
* even if there can be a little performance hit with hardware NICs.
* However, using the qdisc is the safer approach, for two reasons:
* 1) it prevents non-fifo qdiscs to break the TX notification
* scheme, which is based on mbuf destructors when txqdisc is
* not used.
* 2) it makes it possible to transmit over software devices that
* change skb->dev, like bridge, veth, ...
*
* Anyway users looking for the best performance should
* use native adapters.
*/
int netmap_generic_txqdisc = 1;
/* Default number of slots and queues for generic adapters. */
int netmap_generic_ringsize = 1024;
int netmap_generic_rings = 1;
/* Non-zero if ptnet devices are allowed to use virtio-net headers. */
int ptnet_vnet_hdr = 1;
/*
* SYSCTL calls are grouped between SYSBEGIN and SYSEND to be emulated
* in some other operating systems
*/
SYSBEGIN(main_init);
SYSCTL_DECL(_dev_netmap);
SYSCTL_NODE(_dev, OID_AUTO, netmap, CTLFLAG_RW, 0, "Netmap args");
SYSCTL_INT(_dev_netmap, OID_AUTO, verbose,
CTLFLAG_RW, &netmap_verbose, 0, "Verbose mode");
SYSCTL_INT(_dev_netmap, OID_AUTO, no_timestamp,
CTLFLAG_RW, &netmap_no_timestamp, 0, "no_timestamp");
SYSCTL_INT(_dev_netmap, OID_AUTO, mitigate, CTLFLAG_RW, &netmap_mitigate, 0, "");
SYSCTL_INT(_dev_netmap, OID_AUTO, no_pendintr,
CTLFLAG_RW, &netmap_no_pendintr, 0, "Always look for new received packets.");
SYSCTL_INT(_dev_netmap, OID_AUTO, txsync_retry, CTLFLAG_RW,
&netmap_txsync_retry, 0 , "Number of txsync loops in bridge's flush.");
SYSCTL_INT(_dev_netmap, OID_AUTO, adaptive_io, CTLFLAG_RW,
&netmap_adaptive_io, 0 , "Adaptive I/O on paravirt");
SYSCTL_INT(_dev_netmap, OID_AUTO, flags, CTLFLAG_RW, &netmap_flags, 0 , "");
SYSCTL_INT(_dev_netmap, OID_AUTO, fwd, CTLFLAG_RW, &netmap_fwd, 0 , "");
SYSCTL_INT(_dev_netmap, OID_AUTO, admode, CTLFLAG_RW, &netmap_admode, 0 , "");
SYSCTL_INT(_dev_netmap, OID_AUTO, generic_mit, CTLFLAG_RW, &netmap_generic_mit, 0 , "");
SYSCTL_INT(_dev_netmap, OID_AUTO, generic_ringsize, CTLFLAG_RW, &netmap_generic_ringsize, 0 , "");
SYSCTL_INT(_dev_netmap, OID_AUTO, generic_rings, CTLFLAG_RW, &netmap_generic_rings, 0 , "");
SYSCTL_INT(_dev_netmap, OID_AUTO, generic_txqdisc, CTLFLAG_RW, &netmap_generic_txqdisc, 0 , "");
SYSCTL_INT(_dev_netmap, OID_AUTO, ptnet_vnet_hdr, CTLFLAG_RW, &ptnet_vnet_hdr, 0 , "");
#ifdef WITH_NMCONF
SYSCTL_INT(_dev_netmap, OID_AUTO, confmode, CTLFLAG_RW, &nm_conf_flat_mode, 0 , "");
#endif
SYSEND;
NMG_LOCK_T netmap_global_lock;
/*
* mark the ring as stopped, and run through the locks
* to make sure other users get to see it.
* stopped must be either NR_KR_STOPPED (for unbounded stop)
* of NR_KR_LOCKED (brief stop for mutual exclusion purposes)
*/
static void
netmap_disable_ring(struct netmap_kring *kr, int stopped)
{
nm_kr_stop(kr, stopped);
// XXX check if nm_kr_stop is sufficient
mtx_lock(&kr->q_lock);
mtx_unlock(&kr->q_lock);
nm_kr_put(kr);
}
/* stop or enable a single ring */
void
netmap_set_ring(struct netmap_adapter *na, u_int ring_id, enum txrx t, int stopped)
{
if (stopped)
netmap_disable_ring(NMR(na, t) + ring_id, stopped);
else
NMR(na, t)[ring_id].nkr_stopped = 0;
}
/* stop or enable all the rings of na */
void
netmap_set_all_rings(struct netmap_adapter *na, int stopped)
{
int i;
enum txrx t;
if (!nm_netmap_on(na))
return;
for_rx_tx(t) {
for (i = 0; i < netmap_real_rings(na, t); i++) {
netmap_set_ring(na, i, t, stopped);
}
}
}
/*
* Convenience function used in drivers. Waits for current txsync()s/rxsync()s
* to finish and prevents any new one from starting. Call this before turning
* netmap mode off, or before removing the hardware rings (e.g., on module
* onload).
*/
void
netmap_disable_all_rings(struct ifnet *ifp)
{
if (NM_NA_VALID(ifp)) {
netmap_set_all_rings(NA(ifp), NM_KR_STOPPED);
}
}
/*
* Convenience function used in drivers. Re-enables rxsync and txsync on the
* adapter's rings In linux drivers, this should be placed near each
* napi_enable().
*/
void
netmap_enable_all_rings(struct ifnet *ifp)
{
if (NM_NA_VALID(ifp)) {
netmap_set_all_rings(NA(ifp), 0 /* enabled */);
}
}
void
netmap_make_zombie(struct ifnet *ifp)
{
if (NM_NA_VALID(ifp)) {
struct netmap_adapter *na = NA(ifp);
netmap_set_all_rings(na, NM_KR_LOCKED);
na->na_flags |= NAF_ZOMBIE;
netmap_set_all_rings(na, 0);
}
}
void
netmap_undo_zombie(struct ifnet *ifp)
{
if (NM_NA_VALID(ifp)) {
struct netmap_adapter *na = NA(ifp);
if (na->na_flags & NAF_ZOMBIE) {
netmap_set_all_rings(na, NM_KR_LOCKED);
na->na_flags &= ~NAF_ZOMBIE;
netmap_set_all_rings(na, 0);
}
}
}
/*
* generic bound_checking function
*/
u_int
nm_bound_var(u_int *v, u_int dflt, u_int lo, u_int hi, const char *msg)
{
u_int oldv = *v;
const char *op = NULL;
if (dflt < lo)
dflt = lo;
if (dflt > hi)
dflt = hi;
if (oldv < lo) {
*v = dflt;
op = "Bump";
} else if (oldv > hi) {
*v = hi;
op = "Clamp";
}
if (op && msg)
printf("%s %s to %d (was %d)\n", op, msg, *v, oldv);
return *v;
}
/*
* packet-dump function, user-supplied or static buffer.
* The destination buffer must be at least 30+4*len
*/
const char *
nm_dump_buf(char *p, int len, int lim, char *dst)
{
static char _dst[8192];
int i, j, i0;
static char hex[] ="0123456789abcdef";
char *o; /* output position */
#define P_HI(x) hex[((x) & 0xf0)>>4]
#define P_LO(x) hex[((x) & 0xf)]
#define P_C(x) ((x) >= 0x20 && (x) <= 0x7e ? (x) : '.')
if (!dst)
dst = _dst;
if (lim <= 0 || lim > len)
lim = len;
o = dst;
sprintf(o, "buf 0x%p len %d lim %d\n", p, len, lim);
o += strlen(o);
/* hexdump routine */
for (i = 0; i < lim; ) {
sprintf(o, "%5d: ", i);
o += strlen(o);
memset(o, ' ', 48);
i0 = i;
for (j=0; j < 16 && i < lim; i++, j++) {
o[j*3] = P_HI(p[i]);
o[j*3+1] = P_LO(p[i]);
}
i = i0;
for (j=0; j < 16 && i < lim; i++, j++)
o[j + 48] = P_C(p[i]);
o[j+48] = '\n';
o += j+49;
}
*o = '\0';
#undef P_HI
#undef P_LO
#undef P_C
return dst;
}
/*
* Fetch configuration from the device, to cope with dynamic
* reconfigurations after loading the module.
*/
/* call with NMG_LOCK held */
int
netmap_update_config(struct netmap_adapter *na)
{
u_int txr, txd, rxr, rxd;
txr = txd = rxr = rxd = 0;
if (na->nm_config == NULL ||
na->nm_config(na, &txr, &txd, &rxr, &rxd))
{
/* take whatever we had at init time */
txr = na->num_tx_rings;
txd = na->num_tx_desc;
rxr = na->num_rx_rings;
rxd = na->num_rx_desc;
}
if (na->num_tx_rings == txr && na->num_tx_desc == txd &&
na->num_rx_rings == rxr && na->num_rx_desc == rxd)
return 0; /* nothing changed */
if (netmap_verbose || na->active_fds > 0) {
D("stored config %s: txring %d x %d, rxring %d x %d",
na->name,
na->num_tx_rings, na->num_tx_desc,
na->num_rx_rings, na->num_rx_desc);
D("new config %s: txring %d x %d, rxring %d x %d",
na->name, txr, txd, rxr, rxd);
}
if (na->active_fds == 0) {
D("configuration changed (but fine)");
na->num_tx_rings = txr;
na->num_tx_desc = txd;
na->num_rx_rings = rxr;
na->num_rx_desc = rxd;
return 0;
}
D("configuration changed while active, this is bad...");
return 1;
}
/* nm_sync callbacks for the host rings */
static int netmap_txsync_to_host(struct netmap_kring *kring, int flags);
static int netmap_rxsync_from_host(struct netmap_kring *kring, int flags);
/* create the krings array and initialize the fields common to all adapters.
* The array layout is this:
*
* +----------+
* na->tx_rings ----->| | \
* | | } na->num_tx_ring
* | | /
* +----------+
* | | host tx kring
* na->rx_rings ----> +----------+
* | | \
* | | } na->num_rx_rings
* | | /
* +----------+
* | | host rx kring
* +----------+
* na->tailroom ----->| | \
* | | } tailroom bytes
* | | /
* +----------+
*
* Note: for compatibility, host krings are created even when not needed.
* The tailroom space is currently used by vale ports for allocating leases.
*/
/* call with NMG_LOCK held */
int
netmap_krings_create(struct netmap_adapter *na, u_int tailroom)
{
u_int i, len, ndesc;
struct netmap_kring *kring;
u_int n[NR_TXRX];
enum txrx t;
/* account for the (possibly fake) host rings */
n[NR_TX] = na->num_tx_rings + 1;
n[NR_RX] = na->num_rx_rings + 1;
len = (n[NR_TX] + n[NR_RX]) * sizeof(struct netmap_kring) + tailroom;
na->tx_rings = nm_os_malloc((size_t)len);
if (na->tx_rings == NULL) {
D("Cannot allocate krings");
return ENOMEM;
}
na->rx_rings = na->tx_rings + n[NR_TX];
/*
* All fields in krings are 0 except the one initialized below.
* but better be explicit on important kring fields.
*/
for_rx_tx(t) {
ndesc = nma_get_ndesc(na, t);
for (i = 0; i < n[t]; i++) {
kring = &NMR(na, t)[i];
bzero(kring, sizeof(*kring));
kring->na = na;
kring->ring_id = i;
kring->tx = t;
kring->nkr_num_slots = ndesc;
kring->nr_mode = NKR_NETMAP_OFF;
kring->nr_pending_mode = NKR_NETMAP_OFF;
if (i < nma_get_nrings(na, t)) {
kring->nm_sync = (t == NR_TX ? na->nm_txsync : na->nm_rxsync);
} else {
kring->nm_sync = (t == NR_TX ?
netmap_txsync_to_host:
netmap_rxsync_from_host);
}
kring->nm_notify = na->nm_notify;
kring->rhead = kring->rcur = kring->nr_hwcur = 0;
/*
* IMPORTANT: Always keep one slot empty.
*/
kring->rtail = kring->nr_hwtail = (t == NR_TX ? ndesc - 1 : 0);
snprintf(kring->name, sizeof(kring->name) - 1, "%s %s%d", na->name,
nm_txrx2str(t), i);
ND("ktx %s h %d c %d t %d",
kring->name, kring->rhead, kring->rcur, kring->rtail);
mtx_init(&kring->q_lock, (t == NR_TX ? "nm_txq_lock" : "nm_rxq_lock"), NULL, MTX_DEF);
nm_os_selinfo_init(&kring->si);
}
nm_os_selinfo_init(&na->si[t]);
}
na->tailroom = na->rx_rings + n[NR_RX];
return 0;
}
/* undo the actions performed by netmap_krings_create */
/* call with NMG_LOCK held */
void
netmap_krings_delete(struct netmap_adapter *na)
{
struct netmap_kring *kring = na->tx_rings;
enum txrx t;
for_rx_tx(t)
nm_os_selinfo_uninit(&na->si[t]);
/* we rely on the krings layout described above */
for ( ; kring != na->tailroom; kring++) {
mtx_destroy(&kring->q_lock);
nm_os_selinfo_uninit(&kring->si);
}
nm_os_free(na->tx_rings);
na->tx_rings = na->rx_rings = na->tailroom = NULL;
}
/*
* Destructor for NIC ports. They also have an mbuf queue
* on the rings connected to the host so we need to purge
* them first.
*/
/* call with NMG_LOCK held */
void
netmap_hw_krings_delete(struct netmap_adapter *na)
{
struct mbq *q = &na->rx_rings[na->num_rx_rings].rx_queue;
ND("destroy sw mbq with len %d", mbq_len(q));
mbq_purge(q);
mbq_safe_fini(q);
netmap_krings_delete(na);
}
/*
* Undo everything that was done in netmap_do_regif(). In particular,
* call nm_register(ifp,0) to stop netmap mode on the interface and
* revert to normal operation.
*/
/* call with NMG_LOCK held */
static void netmap_unset_ringid(struct netmap_priv_d *);
static void netmap_krings_put(struct netmap_priv_d *);
void
netmap_do_unregif(struct netmap_priv_d *priv)
{
struct netmap_adapter *na = priv->np_na;
NMG_LOCK_ASSERT();
na->active_fds--;
/* unset nr_pending_mode and possibly release exclusive mode */
netmap_krings_put(priv);
#ifdef WITH_MONITOR
/* XXX check whether we have to do something with monitor
* when rings change nr_mode. */
if (na->active_fds <= 0) {
/* walk through all the rings and tell any monitor
* that the port is going to exit netmap mode
*/
netmap_monitor_stop(na);
}
#endif
if (na->active_fds <= 0 || nm_kring_pending(priv)) {
na->nm_register(na, 0);
}
/* delete rings and buffers that are no longer needed */
netmap_mem_rings_delete(na);
if (na->active_fds <= 0) { /* last instance */
/*
* (TO CHECK) We enter here
* when the last reference to this file descriptor goes
* away. This means we cannot have any pending poll()
* or interrupt routine operating on the structure.
* XXX The file may be closed in a thread while
* another thread is using it.
* Linux keeps the file opened until the last reference
* by any outstanding ioctl/poll or mmap is gone.
* FreeBSD does not track mmap()s (but we do) and
* wakes up any sleeping poll(). Need to check what
* happens if the close() occurs while a concurrent
* syscall is running.
*/
if (netmap_verbose)
D("deleting last instance for %s", na->name);
if (nm_netmap_on(na)) {
D("BUG: netmap on while going to delete the krings");
}
na->nm_krings_delete(na);
}
/* possibily decrement counter of tx_si/rx_si users */
netmap_unset_ringid(priv);
/* delete the nifp */
netmap_mem_if_delete(na, priv->np_nifp);
/* drop the allocator */
netmap_mem_deref(na->nm_mem, na);
/* mark the priv as unregistered */
priv->np_na = NULL;
priv->np_nifp = NULL;
}
/* call with NMG_LOCK held */
static __inline int
nm_si_user(struct netmap_priv_d *priv, enum txrx t)
{
return (priv->np_na != NULL &&
(priv->np_qlast[t] - priv->np_qfirst[t] > 1));
}
struct netmap_priv_d*
netmap_priv_new(void)
{
struct netmap_priv_d *priv;
priv = nm_os_malloc(sizeof(struct netmap_priv_d));
if (priv == NULL)
return NULL;
priv->np_refs = 1;
nm_os_get_module();
#ifdef WITH_NMCONF
nm_conf_init(&priv->conf);
#endif