ce3ee1e7c4
This includes the following: - use separate memory regions for VALE ports - locking fixes - some simplifications in the NIC-specific routines - performance improvements for the VALE switch - some new features in the pkt-gen test program - documentation updates There are small API changes that require programs to be recompiled (NETMAP_API has been bumped so you will detect old binaries at runtime). In particular: - struct netmap_slot now is 16 bytes to support an extra pointer, which may save one data copy when using VALE ports or VMs; - the struct netmap_if has two extra fields; MFC after: 3 days
373 lines
14 KiB
C
373 lines
14 KiB
C
/*
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* Copyright (C) 2011-2013 Matteo Landi, Luigi Rizzo. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the
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* distribution.
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*
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* 3. Neither the name of the authors nor the names of their contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY MATTEO LANDI AND CONTRIBUTORS "AS IS" AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTEO LANDI OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
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* THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* $FreeBSD$
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*
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* Definitions of constants and the structures used by the netmap
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* framework, for the part visible to both kernel and userspace.
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* Detailed info on netmap is available with "man netmap" or at
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*
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* http://info.iet.unipi.it/~luigi/netmap/
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*
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* This API is also used to communicate with the VALE software switch
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*/
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#ifndef _NET_NETMAP_H_
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#define _NET_NETMAP_H_
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/*
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* --- Netmap data structures ---
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*
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* The userspace data structures used by netmap are shown below.
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* They are allocated by the kernel and mmap()ed by userspace threads.
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* Pointers are implemented as memory offsets or indexes,
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* so that they can be easily dereferenced in kernel and userspace.
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KERNEL (opaque, obviously)
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====================================================================
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USERSPACE | struct netmap_ring
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+---->+--------------+
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/ | cur |
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struct netmap_if (nifp, 1 per fd) / | avail |
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+---------------+ / | buf_ofs |
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| ni_tx_rings | / +==============+
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| ni_rx_rings | / | buf_idx, len | slot[0]
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| | / | flags, ptr |
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| | / +--------------+
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+===============+ / | buf_idx, len | slot[1]
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| txring_ofs[0] | (rel.to nifp)--' | flags, ptr |
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| txring_ofs[1] | +--------------+
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(ni_tx_rings+1 entries) (num_slots entries)
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| txring_ofs[t] | | buf_idx, len | slot[n-1]
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+---------------+ | flags, ptr |
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| rxring_ofs[0] | +--------------+
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| rxring_ofs[1] |
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(ni_rx_rings+1 entries)
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| rxring_ofs[r] |
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+---------------+
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* For each "interface" (NIC, host stack, VALE switch port) attached to a
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* file descriptor, the mmap()ed region contains a (logically readonly)
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* struct netmap_if pointing to struct netmap_ring's.
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* There is one netmap_ring per physical NIC ring, plus one tx/rx ring
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* pair attached to the host stack (this pair is unused for VALE ports).
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*
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* All physical/host stack ports share the same memory region,
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* so that zero-copy can be implemented between them.
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* VALE switch ports instead have separate memory regions.
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*
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* The netmap_ring is the userspace-visible replica of the NIC ring.
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* Each slot has the index of a buffer (MTU-sized and residing in the
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* mmapped region), its length and some flags. An extra 64-bit pointer
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* is provided for user-supplied buffers in the tx path.
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*
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* In user space, the buffer address is computed as
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* (char *)ring + buf_ofs + index*NETMAP_BUF_SIZE
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*/
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/*
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* struct netmap_slot is a buffer descriptor
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*
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* buf_idx the index of the buffer associated to the slot.
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* len the length of the payload
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* flags control operation on the slot, as defined below
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*
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* NS_BUF_CHANGED must be set whenever userspace wants
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* to change buf_idx (it might be necessary to
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* reprogram the NIC)
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*
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* NS_REPORT must be set if we want the NIC to generate an interrupt
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* when this slot is used. Leaving it to 0 improves
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* performance.
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*
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* NS_FORWARD if set on a receive ring, and the device is in
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* transparent mode, buffers released with the flag set
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* will be forwarded to the 'other' side (host stack
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* or NIC, respectively) on the next select() or ioctl()
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*
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* NS_NO_LEARN on a VALE switch, do not 'learn' the source port for
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* this packet.
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*
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* NS_INDIRECT (tx rings only) data is in a userspace buffer pointed
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* by the ptr field in the slot.
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*
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* NS_MOREFRAG Part of a multi-segment frame. The last (or only)
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* segment must not have this flag.
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* Only supported on VALE ports.
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*
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* NS_PORT_MASK the high 8 bits of the flag, if not zero, indicate the
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* destination port for the VALE switch, overriding
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* the lookup table.
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*/
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struct netmap_slot {
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uint32_t buf_idx; /* buffer index */
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uint16_t len; /* packet length */
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uint16_t flags; /* buf changed, etc. */
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#define NS_BUF_CHANGED 0x0001 /* buf_idx changed */
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#define NS_REPORT 0x0002 /* ask the hardware to report results
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* e.g. by generating an interrupt
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*/
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#define NS_FORWARD 0x0004 /* pass packet to the other endpoint
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* (host stack or device)
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*/
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#define NS_NO_LEARN 0x0008
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#define NS_INDIRECT 0x0010
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#define NS_MOREFRAG 0x0020
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#define NS_PORT_SHIFT 8
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#define NS_PORT_MASK (0xff << NS_PORT_SHIFT)
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/*
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* in rx rings, the high 8 bits
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* are the number of fragments.
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*/
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#define NS_RFRAGS(_slot) ( ((_slot)->flags >> 8) & 0xff)
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uint64_t ptr; /* pointer for indirect buffers */
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};
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/*
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* struct netmap_ring
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*
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* Netmap representation of a TX or RX ring (also known as "queue").
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* This is a queue implemented as a fixed-size circular array.
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* At the software level, two fields are important: avail and cur.
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*
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* In TX rings:
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*
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* avail tells how many slots are available for transmission.
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* It is updated by the kernel in each netmap system call.
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* It MUST BE decremented by the user when it
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* adds a new packet to send.
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*
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* cur indicates the slot to use for the next packet
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* to send (i.e. the "tail" of the queue).
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* It MUST BE incremented by the user before
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* netmap system calls to reflect the number of newly
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* sent packets.
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* It is checked by the kernel on netmap system calls
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* (normally unmodified by the kernel unless invalid).
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*
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* In RX rings:
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*
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* avail is the number of packets available (possibly 0).
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* It is updated by the kernel in each netmap system call.
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* It MUST BE decremented by the user when it
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* consumes a packet.
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*
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* cur indicates the first slot that contains a packet not
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* yet processed (the "head" of the queue).
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* It MUST BE incremented by the user when it consumes
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* a packet.
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*
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* reserved indicates the number of buffers before 'cur'
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* that the user has not released yet. Normally 0,
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* it MUST BE incremented by the user when it
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* does not return the buffer immediately, and decremented
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* when the buffer is finally freed.
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*
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*
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* DATA OWNERSHIP/LOCKING:
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* The netmap_ring, all slots, and buffers in the range
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* [reserved-cur , cur+avail[ are owned by the user program,
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* and the kernel only touches them in the same thread context
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* during a system call.
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* Other buffers are reserved for use by the NIC's DMA engines.
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*
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* FLAGS
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* NR_TIMESTAMP updates the 'ts' field on each syscall. This is
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* a global timestamp for all packets.
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* NR_RX_TSTMP if set, the last 64 byte in each buffer will
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* contain a timestamp for the frame supplied by
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* the hardware (if supported)
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* NR_FORWARD if set, the NS_FORWARD flag in each slot of the
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* RX ring is checked, and if set the packet is
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* passed to the other side (host stack or device,
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* respectively). This permits bpf-like behaviour
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* or transparency for selected packets.
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*/
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struct netmap_ring {
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/*
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* buf_ofs is meant to be used through macros.
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* It contains the offset of the buffer region from this
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* descriptor.
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*/
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const ssize_t buf_ofs;
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const uint32_t num_slots; /* number of slots in the ring. */
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uint32_t avail; /* number of usable slots */
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uint32_t cur; /* 'current' r/w position */
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uint32_t reserved; /* not refilled before current */
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const uint16_t nr_buf_size;
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uint16_t flags;
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#define NR_TIMESTAMP 0x0002 /* set timestamp on *sync() */
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#define NR_FORWARD 0x0004 /* enable NS_FORWARD for ring */
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#define NR_RX_TSTMP 0x0008 /* set rx timestamp in slots */
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struct timeval ts; /* time of last *sync() */
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/* the slots follow. This struct has variable size */
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struct netmap_slot slot[0]; /* array of slots. */
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};
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/*
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* Netmap representation of an interface and its queue(s).
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* This is initialized by the kernel when binding a file
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* descriptor to a port, and should be considered as readonly
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* by user programs. The kernel never uses it.
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*
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* There is one netmap_if for each file descriptor on which we want
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* to select/poll.
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* select/poll operates on one or all pairs depending on the value of
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* nmr_queueid passed on the ioctl.
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*/
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struct netmap_if {
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char ni_name[IFNAMSIZ]; /* name of the interface. */
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const uint32_t ni_version; /* API version, currently unused */
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const uint32_t ni_flags; /* properties */
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#define NI_PRIV_MEM 0x1 /* private memory region */
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const uint32_t ni_rx_rings; /* number of rx rings */
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const uint32_t ni_tx_rings; /* number of tx rings */
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/*
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* The following array contains the offset of each netmap ring
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* from this structure. The first ni_tx_rings+1 entries refer
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* to the tx rings, the next ni_rx_rings+1 refer to the rx rings
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* (the last entry in each block refers to the host stack rings).
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* The area is filled up by the kernel on NIOCREGIF,
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* and then only read by userspace code.
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*/
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const ssize_t ring_ofs[0];
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};
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#ifndef NIOCREGIF
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/*
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* ioctl names and related fields
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*
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* NIOCGINFO takes a struct ifreq, the interface name is the input,
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* the outputs are number of queues and number of descriptor
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* for each queue (useful to set number of threads etc.).
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* The info returned is only advisory and may change before
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* the interface is bound to a file descriptor.
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*
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* NIOCREGIF takes an interface name within a struct ifreq,
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* and activates netmap mode on the interface (if possible).
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*
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* nr_name is the name of the interface
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*
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* nr_tx_slots, nr_tx_slots, nr_tx_rings, nr_rx_rings
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* indicate the configuration of the port on return.
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*
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* On input, non-zero values for nr_tx_rings, nr_tx_slots and the
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* rx counterparts may be used to reconfigure the port according
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* to the requested values, but this is not guaranteed.
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* The actual values are returned on completion of the ioctl().
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*
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* nr_ringid
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* indicates how rings should be bound to the file descriptors.
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* The default (0) means all physical rings of a NIC are bound.
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* NETMAP_HW_RING plus a ring number lets you bind just
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* a single ring pair.
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* NETMAP_SW_RING binds only the host tx/rx rings
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* NETMAP_NO_TX_POLL prevents select()/poll() from pushing
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* out packets on the tx ring unless POLLOUT is specified.
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*
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* NETMAP_PRIV_MEM is a return value used to indicate that
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* this ring is in a private memory region hence buffer
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* swapping cannot be used
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*
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* nr_cmd is used to configure NICs attached to a VALE switch,
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* or to dump the configuration of a VALE switch.
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*
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* nr_cmd = NETMAP_BDG_ATTACH and nr_name = vale*:ifname
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* attaches the NIC to the switch, with nr_ringid specifying
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* which rings to use
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*
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* nr_cmd = NETMAP_BDG_DETACH and nr_name = vale*:ifname
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* disconnects a previously attached NIC
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*
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* nr_cmd = NETMAP_BDG_LIST is used to list the configuration
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* of VALE switches, with additional arguments.
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*
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* NIOCTXSYNC, NIOCRXSYNC synchronize tx or rx queues,
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* whose identity is set in NIOCREGIF through nr_ringid
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*
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* NETMAP_API is the API version.
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*/
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/*
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* struct nmreq overlays a struct ifreq
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*/
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struct nmreq {
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char nr_name[IFNAMSIZ];
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uint32_t nr_version; /* API version */
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#define NETMAP_API 5 /* current version */
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uint32_t nr_offset; /* nifp offset in the shared region */
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uint32_t nr_memsize; /* size of the shared region */
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uint32_t nr_tx_slots; /* slots in tx rings */
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uint32_t nr_rx_slots; /* slots in rx rings */
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uint16_t nr_tx_rings; /* number of tx rings */
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uint16_t nr_rx_rings; /* number of rx rings */
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uint16_t nr_ringid; /* ring(s) we care about */
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#define NETMAP_PRIV_MEM 0x8000 /* rings use private memory */
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#define NETMAP_HW_RING 0x4000 /* low bits indicate one hw ring */
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#define NETMAP_SW_RING 0x2000 /* process the sw ring */
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#define NETMAP_NO_TX_POLL 0x1000 /* no automatic txsync on poll */
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#define NETMAP_RING_MASK 0xfff /* the ring number */
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uint16_t nr_cmd;
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#define NETMAP_BDG_ATTACH 1 /* attach the NIC */
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#define NETMAP_BDG_DETACH 2 /* detach the NIC */
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#define NETMAP_BDG_LOOKUP_REG 3 /* register lookup function */
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#define NETMAP_BDG_LIST 4 /* get bridge's info */
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uint16_t nr_arg1;
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#define NETMAP_BDG_HOST 1 /* attach the host stack on ATTACH */
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uint16_t nr_arg2;
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uint32_t spare2[3];
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};
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/*
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* FreeBSD uses the size value embedded in the _IOWR to determine
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* how much to copy in/out. So we need it to match the actual
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* data structure we pass. We put some spares in the structure
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* to ease compatibility with other versions
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*/
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#define NIOCGINFO _IOWR('i', 145, struct nmreq) /* return IF info */
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#define NIOCREGIF _IOWR('i', 146, struct nmreq) /* interface register */
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#define NIOCUNREGIF _IO('i', 147) /* deprecated. Was interface unregister */
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#define NIOCTXSYNC _IO('i', 148) /* sync tx queues */
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#define NIOCRXSYNC _IO('i', 149) /* sync rx queues */
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#endif /* !NIOCREGIF */
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#endif /* _NET_NETMAP_H_ */
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