1 /* 2 * Copyright (C) 2011 Matteo Landi, Luigi Rizzo. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the 14 * distribution. 15 * 16 * 3. Neither the name of the authors nor the names of their contributors 17 * may be used to endorse or promote products derived from this 18 * software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY MATTEO LANDI AND CONTRIBUTORS "AS IS" AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTEO LANDI OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 30 * THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * $FreeBSD$ 35 * $Id: netmap_user.h 10597 2012-02-21 05:08:32Z luigi $ 36 * 37 * This header contains the macros used to manipulate netmap structures 38 * and packets in userspace. See netmap(4) for more information. 39 * 40 * The address of the struct netmap_if, say nifp, is computed from the 41 * value returned from ioctl(.., NIOCREG, ...) and the mmap region: 42 * ioctl(fd, NIOCREG, &req); 43 * mem = mmap(0, ... ); 44 * nifp = NETMAP_IF(mem, req.nr_nifp); 45 * (so simple, we could just do it manually) 46 * 47 * From there: 48 * struct netmap_ring *NETMAP_TXRING(nifp, index) 49 * struct netmap_ring *NETMAP_RXRING(nifp, index) 50 * we can access ring->nr_cur, ring->nr_avail, ring->nr_flags 51 * 52 * ring->slot[i] gives us the i-th slot (we can access 53 * directly plen, flags, bufindex) 54 * 55 * char *buf = NETMAP_BUF(ring, index) returns a pointer to 56 * the i-th buffer 57 * 58 * Since rings are circular, we have macros to compute the next index 59 * i = NETMAP_RING_NEXT(ring, i); 60 */ 61 62 #ifndef _NET_NETMAP_USER_H_ 63 #define _NET_NETMAP_USER_H_ 64 65 #define _NETMAP_OFFSET(type, ptr, offset) \ 66 ((type)(void *)((char *)(ptr) + (offset))) 67 68 #define NETMAP_IF(b, o) _NETMAP_OFFSET(struct netmap_if *, b, o) 69 70 #define NETMAP_TXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \ 71 nifp, (nifp)->ring_ofs[index] ) 72 73 #define NETMAP_RXRING(nifp, index) _NETMAP_OFFSET(struct netmap_ring *, \ 74 nifp, (nifp)->ring_ofs[index + (nifp)->ni_tx_rings + 1] ) 75 76 #define NETMAP_BUF(ring, index) \ 77 ((char *)(ring) + (ring)->buf_ofs + ((index)*(ring)->nr_buf_size)) 78 79 #define NETMAP_BUF_IDX(ring, buf) \ 80 ( ((char *)(buf) - ((char *)(ring) + (ring)->buf_ofs) ) / \ 81 (ring)->nr_buf_size ) 82 83 #define NETMAP_RING_NEXT(r, i) \ 84 ((i)+1 == (r)->num_slots ? 0 : (i) + 1 ) 85 86 #define NETMAP_RING_FIRST_RESERVED(r) \ 87 ( (r)->cur < (r)->reserved ? \ 88 (r)->cur + (r)->num_slots - (r)->reserved : \ 89 (r)->cur - (r)->reserved ) 90 91 /* 92 * Return 1 if the given tx ring is empty. 93 */ 94 #define NETMAP_TX_RING_EMPTY(r) ((r)->avail >= (r)->num_slots - 1) 95 96 #endif /* _NET_NETMAP_USER_H_ */ 97