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Diffstat (limited to 'examples/netmap_compat/netmap/netmap.h')
| -rw-r--r-- | examples/netmap_compat/netmap/netmap.h | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/examples/netmap_compat/netmap/netmap.h b/examples/netmap_compat/netmap/netmap.h new file mode 100644 index 00000000..677c8a9f --- /dev/null +++ b/examples/netmap_compat/netmap/netmap.h @@ -0,0 +1,289 @@ +/* + * 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_ */ |