--- /dev/null
+/*
+ * Copyright (C) 2011 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.
+ *
+ * 3. Neither the name of the authors nor the names of their contributors
+ * may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY MATTEO LANDI 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 MATTEO LANDI 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: head/sys/net/netmap.h 231198 2012-02-08 11:43:29Z luigi $
+ * $Id: netmap.h 10879 2012-04-12 22:48:59Z luigi $
+ *
+ * Definitions of constants and the structures used by the netmap
+ * framework, for the part visible to both kernel and userspace.
+ * Detailed info on netmap is available with "man netmap" or at
+ *
+ * http://info.iet.unipi.it/~luigi/netmap/
+ */
+
+#ifndef _NET_NETMAP_H_
+#define _NET_NETMAP_H_
+
+/*
+ * --- Netmap data structures ---
+ *
+ * The data structures used by netmap are shown below. Those in
+ * capital letters are in an mmapp()ed area shared with userspace,
+ * while others are private to the kernel.
+ * Shared structures do not contain pointers but only memory
+ * offsets, so that addressing is portable between kernel and userspace.
+
+
+ softc
++----------------+
+| standard fields|
+| if_pspare[0] ----------+
++----------------+ |
+ |
++----------------+<------+
+|(netmap_adapter)|
+| | netmap_kring
+| tx_rings *--------------------------------->+---------------+
+| | netmap_kring | ring *---------.
+| rx_rings *--------->+---------------+ | nr_hwcur | |
++----------------+ | ring *--------. | nr_hwavail | V
+ | nr_hwcur | | | selinfo | |
+ | nr_hwavail | | +---------------+ .
+ | selinfo | | | ... | .
+ +---------------+ | |(ntx+1 entries)|
+ | .... | | | |
+ |(nrx+1 entries)| | +---------------+
+ | | |
+ KERNEL +---------------+ |
+ |
+ ====================================================================
+ |
+ USERSPACE | NETMAP_RING
+ +---->+-------------+
+ / | cur |
+ NETMAP_IF (nifp, one per file desc.) / | avail |
+ +---------------+ / | buf_ofs |
+ | ni_tx_rings | / +=============+
+ | ni_rx_rings | / | buf_idx | slot[0]
+ | | / | len, flags |
+ | | / +-------------+
+ +===============+ / | buf_idx | slot[1]
+ | txring_ofs[0] | (rel.to nifp)--' | len, flags |
+ | txring_ofs[1] | +-------------+
+ (num_rings+1 entries) (nr_num_slots entries)
+ | txring_ofs[n] | | buf_idx | slot[n-1]
+ +---------------+ | len, flags |
+ | rxring_ofs[0] | +-------------+
+ | rxring_ofs[1] |
+ (num_rings+1 entries)
+ | txring_ofs[n] |
+ +---------------+
+
+ * The private descriptor ('softc' or 'adapter') of each interface
+ * is extended with a "struct netmap_adapter" containing netmap-related
+ * info (see description in dev/netmap/netmap_kernel.h.
+ * Among other things, tx_rings and rx_rings point to the arrays of
+ * "struct netmap_kring" which in turn reache the various
+ * "struct netmap_ring", shared with userspace.
+
+ * The NETMAP_RING is the userspace-visible replica of the NIC ring.
+ * Each slot has the index of a buffer, its length and some flags.
+ * In user space, the buffer address is computed as
+ * (char *)ring + buf_ofs + index*NETMAP_BUF_SIZE
+ * In the kernel, buffers do not necessarily need to be contiguous,
+ * and the virtual and physical addresses are derived through
+ * a lookup table.
+ * To associate a different buffer to a slot, applications must
+ * write the new index in buf_idx, and set NS_BUF_CHANGED flag to
+ * make sure that the kernel updates the hardware ring as needed.
+ *
+ * Normally the driver is not requested to report the result of
+ * transmissions (this can dramatically speed up operation).
+ * However the user may request to report completion by setting
+ * NS_REPORT.
+ */
+struct netmap_slot {
+ uint32_t buf_idx; /* buffer index */
+ uint16_t len; /* packet length, to be copied to/from the hw ring */
+ uint16_t flags; /* buf changed, etc. */
+#define NS_BUF_CHANGED 0x0001 /* must resync the map, buffer changed */
+#define NS_REPORT 0x0002 /* ask the hardware to report results
+ * e.g. by generating an interrupt
+ */
+};
+
+/*
+ * Netmap representation of a TX or RX ring (also known as "queue").
+ * This is a queue implemented as a fixed-size circular array.
+ * At the software level, two fields are important: avail and cur.
+ *
+ * In TX rings:
+ * avail indicates the number of slots available for transmission.
+ * It is updated by the kernel after every netmap system call.
+ * It MUST BE decremented by the application when it appends a
+ * packet.
+ * cur indicates the slot to use for the next packet
+ * to send (i.e. the "tail" of the queue).
+ * It MUST BE incremented by the application before
+ * netmap system calls to reflect the number of newly
+ * sent packets.
+ * It is checked by the kernel on netmap system calls
+ * (normally unmodified by the kernel unless invalid).
+ *
+ * The kernel side of netmap uses two additional fields in its own
+ * private ring structure, netmap_kring:
+ * nr_hwcur is a copy of nr_cur on an NIOCTXSYNC.
+ * nr_hwavail is the number of slots known as available by the
+ * hardware. It is updated on an INTR (inc by the
+ * number of packets sent) and on a NIOCTXSYNC
+ * (decrease by nr_cur - nr_hwcur)
+ * A special case, nr_hwavail is -1 if the transmit
+ * side is idle (no pending transmits).
+ *
+ * In RX rings:
+ * avail is the number of packets available (possibly 0).
+ * It MUST BE decremented by the application when it consumes
+ * a packet, and it is updated to nr_hwavail on a NIOCRXSYNC
+ * cur indicates the first slot that contains a packet not
+ * processed yet (the "head" of the queue).
+ * It MUST BE incremented by the software when it consumes
+ * a packet.
+ * reserved indicates the number of buffers before 'cur'
+ * that the application has still in use. Normally 0,
+ * it MUST BE incremented by the application when it
+ * does not return the buffer immediately, and decremented
+ * when the buffer is finally freed.
+ *
+ * The kernel side of netmap uses two additional fields in the kring:
+ * nr_hwcur is a copy of nr_cur on an NIOCRXSYNC
+ * nr_hwavail is the number of packets available. It is updated
+ * on INTR (inc by the number of new packets arrived)
+ * and on NIOCRXSYNC (decreased by nr_cur - nr_hwcur).
+ *
+ * DATA OWNERSHIP/LOCKING:
+ * The netmap_ring is owned by the user program and it is only
+ * accessed or modified in the upper half of the kernel during
+ * a system call.
+ *
+ * The netmap_kring is only modified by the upper half of the kernel.
+ */
+struct netmap_ring {
+ /*
+ * nr_buf_base_ofs is meant to be used through macros.
+ * It contains the offset of the buffer region from this
+ * descriptor.
+ */
+ ssize_t buf_ofs;
+ uint32_t num_slots; /* number of slots in the ring. */
+ uint32_t avail; /* number of usable slots */
+ uint32_t cur; /* 'current' r/w position */
+ uint32_t reserved; /* not refilled before current */
+
+ uint16_t nr_buf_size;
+ uint16_t flags;
+#define NR_TIMESTAMP 0x0002 /* set timestamp on *sync() */
+
+ struct timeval ts; /* time of last *sync() */
+
+ /* the slots follow. This struct has variable size */
+ struct netmap_slot slot[0]; /* array of slots. */
+};
+
+
+/*
+ * Netmap representation of an interface and its queue(s).
+ * There is one netmap_if for each file descriptor on which we want
+ * to select/poll. We assume that on each interface has the same number
+ * of receive and transmit queues.
+ * select/poll operates on one or all pairs depending on the value of
+ * nmr_queueid passed on the ioctl.
+ */
+struct netmap_if {
+ char ni_name[IFNAMSIZ]; /* name of the interface. */
+ u_int ni_version; /* API version, currently unused */
+ u_int ni_rx_rings; /* number of rx rings */
+ u_int ni_tx_rings; /* if zero, same as ni_rx_rings */
+ /*
+ * The following array contains the offset of each netmap ring
+ * from this structure. The first ni_tx_queues+1 entries refer
+ * to the tx rings, the next ni_rx_queues+1 refer to the rx rings
+ * (the last entry in each block refers to the host stack rings).
+ * The area is filled up by the kernel on NIOCREG,
+ * and then only read by userspace code.
+ */
+ ssize_t ring_ofs[0];
+};
+
+#ifndef NIOCREGIF
+/*
+ * ioctl names and related fields
+ *
+ * NIOCGINFO takes a struct ifreq, the interface name is the input,
+ * the outputs are number of queues and number of descriptor
+ * for each queue (useful to set number of threads etc.).
+ *
+ * NIOCREGIF takes an interface name within a struct ifreq,
+ * and activates netmap mode on the interface (if possible).
+ *
+ * NIOCUNREGIF unregisters the interface associated to the fd.
+ *
+ * NIOCTXSYNC, NIOCRXSYNC synchronize tx or rx queues,
+ * whose identity is set in NIOCREGIF through nr_ringid
+ */
+
+/*
+ * struct nmreq overlays a struct ifreq
+ */
+struct nmreq {
+ char nr_name[IFNAMSIZ];
+ uint32_t nr_version; /* API version */
+#define NETMAP_API 3 /* current version */
+ uint32_t nr_offset; /* nifp offset in the shared region */
+ uint32_t nr_memsize; /* size of the shared region */
+ uint32_t nr_tx_slots; /* slots in tx rings */
+ uint32_t nr_rx_slots; /* slots in rx rings */
+ uint16_t nr_tx_rings; /* number of tx rings */
+ uint16_t nr_rx_rings; /* number of rx rings */
+ uint16_t nr_ringid; /* ring(s) we care about */
+#define NETMAP_HW_RING 0x4000 /* low bits indicate one hw ring */
+#define NETMAP_SW_RING 0x2000 /* process the sw ring */
+#define NETMAP_NO_TX_POLL 0x1000 /* no automatic txsync on poll */
+#define NETMAP_RING_MASK 0xfff /* the ring number */
+ uint16_t spare1;
+ uint32_t spare2[4];
+};
+
+/*
+ * FreeBSD uses the size value embedded in the _IOWR to determine
+ * how much to copy in/out. So we need it to match the actual
+ * data structure we pass. We put some spares in the structure
+ * to ease compatibility with other versions
+ */
+#define NIOCGINFO _IOWR('i', 145, struct nmreq) /* return IF info */
+#define NIOCREGIF _IOWR('i', 146, struct nmreq) /* interface register */
+#define NIOCUNREGIF _IO('i', 147) /* interface unregister */
+#define NIOCTXSYNC _IO('i', 148) /* sync tx queues */
+#define NIOCRXSYNC _IO('i', 149) /* sync rx queues */
+#endif /* !NIOCREGIF */
+
+#endif /* _NET_NETMAP_H_ */
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