netmap: Address errors on memory free in netmap_generic

netmap_generic keeps a pool of mbufs for handling transfers, these mbufs
have an external buffer attached to them.

If some cases other parts

netmap: Address errors on memory free in netmap_generic

netmap_generic keeps a pool of mbufs for handling transfers, these mbufs
have an external buffer attached to them.

If some cases other parts of the network stack can chain these mbufs,
when this happens the normal pool destructor function can end up
free'ing the pool mbufs twice:

- A first time if a pool mbuf has been chained with another mbuf when
its chain is freed
- A second time when its entry in the pool is freed

Additionally, if other parts of the stack demote a pool mbuf its
interface reference will be cleared. In this case we deference a NULL
pointer when trying to free the mbuf through the destructor. Store a
reference to the adapter in ext_arg1 with the destructor callback so we
can find the correct adapter when free'ing a pool mbuf.

This change enables using netmap with epair interfaces.

Reviewed By: vmaffione
MFC after: 1 week
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D44371

show more ...

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

show more ...

netmap: Fix queue stalls with generic interfaces

In emulated mode, the FreeBSD netmap port attempts to perform zero-copy
transmission. This works as follows: the kernel ring is populated with
mbuf

netmap: Fix queue stalls with generic interfaces

In emulated mode, the FreeBSD netmap port attempts to perform zero-copy
transmission. This works as follows: the kernel ring is populated with
mbuf headers to which netmap buffers are attached. When transmitting,
the mbuf refcount is initialized to 2, and when the counter value has
been decremented to 1 netmap infers that the driver has freed the mbuf
and thus transmission is complete.

This scheme does not generalize to the situation where netmap is
attaching to a software interface which may transmit packets among
multiple "queues", as is the case with bridge or lagg interfaces. In
that case, we would be relying on backing hardware drivers to free
transmitted mbufs promptly, but this isn't guaranteed; a driver may
reasonably defer freeing a small number of transmitted buffers
indefinitely. If such a buffer ends up at the tail of a netmap transmit
ring, further transmits can end up blocked indefinitely.

Fix the problem by removing the zero-copy scheme (which is also not
implemented in the Linux port of netmap). Instead, the kernel ring is
populated with regular mbuf clusters into which netmap buffers are
copied by nm_os_generic_xmit_frame(). The refcounting scheme is
preserved, and this lets us avoid allocating a fresh cluster per
transmitted packet in the common case. If the transmit ring is full, a
callout is used to free the "stuck" mbuf, avoiding the queue deadlock
described above.

Furthermore, when recycling mbuf clusters, be sure to fully reinitialize
the mbuf header instead of simply re-setting M_PKTHDR. Some software
interfaces, like if_vlan, may set fields in the header which should be
reset before the mbuf is reused.

Reviewed by: vmaffione
MFC after: 1 month
Sponsored by: Zenarmor
Sponsored by: OPNsense
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D38065

show more ...

netmap: get rid of WNA() macro

MFC after: 7 days

Mechanically convert netmap(4) to IfAPI

Reviewed by: vmaffione, zlei
Sponsored by: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D37814

netmap: Try to count packet drops in emulated mode

Right now we have little visibility into packet drops within netmap.
Start trying to make packet loss issues more visible by counting queue
drops i

netmap: Try to count packet drops in emulated mode

Right now we have little visibility into packet drops within netmap.
Start trying to make packet loss issues more visible by counting queue
drops in the transmit path, and in the input path for interfaces running
in emulated mode, where we place received packets in a bounded software
queue that is processed by rxsync.

Reviewed by: vmaffione
MFC after: 1 week
Sponsored by: Zenarmor
Sponsored by: OPNsense
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D38064

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netmap: Fix a queue length check in the generic port rx path

The check is ok by default, since the default value of
netmap_generic_ringsize is 1024. But we should check against the
configured "ring

netmap: Fix a queue length check in the generic port rx path

The check is ok by default, since the default value of
netmap_generic_ringsize is 1024. But we should check against the
configured "ring" size.

Reviewed by: vmaffione
MFC after: 1 week
Sponsored by: Zenarmor
Sponsored by: OPNsense
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D38062

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netmap: drop compatibility FreeBSD code

Netmap users on FreeBSD are not supposed to import code from the
github netmap repository anymore. They should use the code that
is available in the src repo.

netmap: drop compatibility FreeBSD code

Netmap users on FreeBSD are not supposed to import code from the
github netmap repository anymore. They should use the code that
is available in the src repo. We can therefore drop the compatibility
code.

MFC after: 7 days

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netmap: several typo fixes

No functional changes intended.

netmap: add kernel support for the "offsets" feature

This feature enables applications to ask netmap to transmit or
receive packets starting at a user-specified offset from the
beginning of the netm

netmap: add kernel support for the "offsets" feature

This feature enables applications to ask netmap to transmit or
receive packets starting at a user-specified offset from the
beginning of the netmap buffer. This is meant to ease those
packet manipulation operations such as pushing or popping packet
headers, that may be useful to implement software switches,
routers and other packet processors.
To use the feature, drivers (e.g., iflib, vtnet, etc.) must have
explicit support. This change does not add support for any driver,
but introduces the necessary kernel changes. However, offsets support
is already included for VALE ports and pipes.

show more ...

netmap: enter NET_EPOCH on generic txsync

After r353292, netmap generic adapter on if_vlan interfaces panics on
asserting the NET_EPOCH. In more detail, this happens when
nm_os_generic_xmit_frame()

netmap: enter NET_EPOCH on generic txsync

After r353292, netmap generic adapter on if_vlan interfaces panics on
asserting the NET_EPOCH. In more detail, this happens when
nm_os_generic_xmit_frame() is called, that is in the generic txsync
routine.
Fix the issue by entering the NET_EPOCH during the generic txsync.
We amortize the cost of entering/exiting over a whole batch of
transmissions.

PR: 241489
Reported by: Aleksandr Fedorov <aleksandr.fedorov@itglobal.com>

show more ...

MFHead @r350386

Sponsored by: The FreeBSD Foundation

netmap: fix bug introduced by r349752

r349752 introduced a NULL pointer reference bug
in the emulated netmap code.

Reported by: lwhsu
MFC after: 3 days

netmap: fix kernel pointer printing in netmap_generic.c

Print the adapter name rather than the address of the adapter
to avoid kernel address leakage.

PR: Bug 238642
Submitted by: Fuqian Huang <hu

netmap: fix kernel pointer printing in netmap_generic.c

Print the adapter name rather than the address of the adapter
to avoid kernel address leakage.

PR: Bug 238642
Submitted by: Fuqian Huang <huangfq.daxian@gmail.com>
Reviewed by: vmaffione
MFC after: 1 week

show more ...

Merge ^/head r343712 through r343806.

netmap: refactor logging macros and pipes

Changelist:
- Replace ND, D and RD macros with nm_prdis, nm_prinf, nm_prerr
and nm_prlim, to avoid possible naming conflicts.
- Add netmap_kri

netmap: refactor logging macros and pipes

Changelist:
- Replace ND, D and RD macros with nm_prdis, nm_prinf, nm_prerr
and nm_prlim, to avoid possible naming conflicts.
- Add netmap_krings_mode_commit() helper function and use that
to reduce code duplication.
- Refactor pipes control code to export some functions that
can be reused by the veth driver (on Linux) and epair(4).
- Add check to reject API requests with version less than 11.
- Small code refactoring for the null adapter.

MFC after: 1 week

show more ...

Merge ^/head r340918 through r341763.

netmap: align codebase to the current upstream (760279cfb2730a585)

Changelist:
- Replace netmap passthrough host support with a more general
mechanism to call TXSYNC/RXSYNC from an in-kernel e

netmap: align codebase to the current upstream (760279cfb2730a585)

Changelist:
- Replace netmap passthrough host support with a more general
mechanism to call TXSYNC/RXSYNC from an in-kernel event-loop.
No kernel threads are used to use this feature: the application
is required to spawn a thread (or a process) and issue a
SYNC_KLOOP_START (NIOCCTRL) command in the thread body. The
kernel loop is executed by the ioctl implementation, which returns
to userspace only when a different thread calls SYNC_KLOOP_STOP
or the netmap file descriptor is closed.
- Update the if_ptnet driver to cope with the new data structures,
and prune all the obsolete ptnetmap code.
- Add support for "null" netmap ports, useful to allocate netmap_if,
netmap_ring and netmap buffers to be used by specialized applications
(e.g. hypervisors). TXSYNC/RXSYNC on these ports have no effect.
- Various fixes and code refactoring.

Sponsored by: Sunny Valley Networks
Differential Revision: https://reviews.freebsd.org/D18015

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Merge ^/head r339015 through r339669.

netmap: align codebase to the current upstream (sha 8374e1a7e6941)

Changelist:
- Move large parts of VALE code to a new file and header netmap_bdg.[ch].
This is useful to reuse the code wi

netmap: align codebase to the current upstream (sha 8374e1a7e6941)

Changelist:
- Move large parts of VALE code to a new file and header netmap_bdg.[ch].
This is useful to reuse the code within upcoming projects.
- Improvements and bug fixes to pipes and monitors.
- Introduce nm_os_onattach(), nm_os_onenter() and nm_os_onexit() to
handle differences between FreeBSD and Linux.
- Introduce some new helper functions to handle more host rings and fake
rings (netmap_all_rings(), netmap_real_rings(), ...)
- Added new sysctl to enable/disable hw checksum in emulated netmap mode.
- nm_inject: add support for NS_MOREFRAG

Approved by: gnn (mentor)
Differential Revision: https://reviews.freebsd.org/D17364

show more ...

netmap: Address errors on memory free in netmap_generic

netmap_generic keeps a pool of mbufs for handling transfers, these mbufs
have an external buffer attached to them.

If some cases other parts

netmap: Address errors on memory free in netmap_generic

netmap_generic keeps a pool of mbufs for handling transfers, these mbufs
have an external buffer attached to them.

If some cases other parts of the network stack can chain these mbufs,
when this happens the normal pool destructor function can end up
free'ing the pool mbufs twice:

- A first time if a pool mbuf has been chained with another mbuf when
its chain is freed
- A second time when its entry in the pool is freed

Additionally, if other parts of the stack demote a pool mbuf its
interface reference will be cleared. In this case we deference a NULL
pointer when trying to free the mbuf through the destructor. Store a
reference to the adapter in ext_arg1 with the destructor callback so we
can find the correct adapter when free'ing a pool mbuf.

This change enables using netmap with epair interfaces.

Reviewed By: vmaffione
MFC after: 1 week
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D44371

show more ...

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

show more ...

netmap: Fix queue stalls with generic interfaces

In emulated mode, the FreeBSD netmap port attempts to perform zero-copy
transmission. This works as follows: the kernel ring is populated with
mbuf

netmap: Fix queue stalls with generic interfaces

In emulated mode, the FreeBSD netmap port attempts to perform zero-copy
transmission. This works as follows: the kernel ring is populated with
mbuf headers to which netmap buffers are attached. When transmitting,
the mbuf refcount is initialized to 2, and when the counter value has
been decremented to 1 netmap infers that the driver has freed the mbuf
and thus transmission is complete.

This scheme does not generalize to the situation where netmap is
attaching to a software interface which may transmit packets among
multiple "queues", as is the case with bridge or lagg interfaces. In
that case, we would be relying on backing hardware drivers to free
transmitted mbufs promptly, but this isn't guaranteed; a driver may
reasonably defer freeing a small number of transmitted buffers
indefinitely. If such a buffer ends up at the tail of a netmap transmit
ring, further transmits can end up blocked indefinitely.

Fix the problem by removing the zero-copy scheme (which is also not
implemented in the Linux port of netmap). Instead, the kernel ring is
populated with regular mbuf clusters into which netmap buffers are
copied by nm_os_generic_xmit_frame(). The refcounting scheme is
preserved, and this lets us avoid allocating a fresh cluster per
transmitted packet in the common case. If the transmit ring is full, a
callout is used to free the "stuck" mbuf, avoiding the queue deadlock
described above.

Furthermore, when recycling mbuf clusters, be sure to fully reinitialize
the mbuf header instead of simply re-setting M_PKTHDR. Some software
interfaces, like if_vlan, may set fields in the header which should be
reset before the mbuf is reused.

Reviewed by: vmaffione
MFC after: 1 month
Sponsored by: Zenarmor
Sponsored by: OPNsense
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D38065

show more ...