1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2019 Vincenzo Maffione <vmaffione@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 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 distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS 19 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 20 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 21 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 22 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 24 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 25 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef __NET_BACKENDS_PRIV_H__ 29 #define __NET_BACKENDS_PRIV_H__ 30 31 #include <sys/linker_set.h> 32 33 /* 34 * Each network backend registers a set of function pointers that are 35 * used to implement the net backends API. Frontends should not invoke 36 * these functions directly, but should instead use the interface provided by 37 * net_backends.h. 38 */ 39 struct net_backend { 40 const char *prefix; /* prefix matching this backend */ 41 42 /* 43 * Routines used to initialize and cleanup the resources needed 44 * by a backend. The cleanup function is used internally, 45 * and should not be called by the frontend. 46 */ 47 int (*init)(struct net_backend *be, const char *devname, 48 nvlist_t *nvl, net_be_rxeof_t cb, void *param); 49 void (*cleanup)(struct net_backend *be); 50 51 /* 52 * Called to serve a guest transmit request. The scatter-gather 53 * vector provided by the caller has 'iovcnt' elements and contains 54 * the packet to send. 55 */ 56 ssize_t (*send)(struct net_backend *be, const struct iovec *iov, 57 int iovcnt); 58 59 /* 60 * Get the length of the next packet that can be received from 61 * the backend. If no packets are currently available, this 62 * function returns 0. 63 */ 64 ssize_t (*peek_recvlen)(struct net_backend *be); 65 66 /* 67 * Called to receive a packet from the backend. When the function 68 * returns a positive value 'len', the scatter-gather vector 69 * provided by the caller contains a packet with such length. 70 * The function returns 0 if the backend doesn't have a new packet to 71 * receive. 72 */ 73 ssize_t (*recv)(struct net_backend *be, const struct iovec *iov, 74 int iovcnt); 75 76 /* 77 * Ask the backend to enable or disable receive operation in the 78 * backend. On return from a disable operation, it is guaranteed 79 * that the receive callback won't be called until receive is 80 * enabled again. Note however that it is up to the caller to make 81 * sure that netbe_recv() is not currently being executed by another 82 * thread. 83 */ 84 void (*recv_enable)(struct net_backend *be); 85 void (*recv_disable)(struct net_backend *be); 86 87 /* 88 * Ask the backend for the virtio-net features it is able to 89 * support. Possible features are TSO, UFO and checksum offloading 90 * in both rx and tx direction and for both IPv4 and IPv6. 91 */ 92 uint64_t (*get_cap)(struct net_backend *be); 93 94 /* 95 * Tell the backend to enable/disable the specified virtio-net 96 * features (capabilities). 97 */ 98 int (*set_cap)(struct net_backend *be, uint64_t features, 99 unsigned int vnet_hdr_len); 100 101 struct pci_vtnet_softc *sc; 102 int fd; 103 104 /* 105 * Length of the virtio-net header used by the backend and the 106 * frontend, respectively. A zero value means that the header 107 * is not used. 108 */ 109 unsigned int be_vnet_hdr_len; 110 unsigned int fe_vnet_hdr_len; 111 112 /* Size of backend-specific private data. */ 113 size_t priv_size; 114 115 /* Backend-specific private data follows. */ 116 }; 117 118 #define NET_BE_PRIV(be) ((void *)((be) + 1)) 119 120 SET_DECLARE(net_backend_set, struct net_backend); 121 122 #define VNET_HDR_LEN sizeof(struct virtio_net_rxhdr) 123 124 /* 125 * Export the tap backend routines for the benefit of other backends which have 126 * a similar interface to the kernel, i.e., they send and receive data using 127 * standard I/O system calls with a single file descriptor. 128 */ 129 130 struct tap_priv { 131 struct mevent *mevp; 132 /* 133 * A bounce buffer that allows us to implement the peek_recvlen 134 * callback. In the future we may get the same information from 135 * the kevent data. 136 */ 137 char bbuf[1 << 16]; 138 ssize_t bbuflen; 139 }; 140 141 void tap_cleanup(struct net_backend *be); 142 ssize_t tap_send(struct net_backend *be, const struct iovec *iov, int iovcnt); 143 ssize_t tap_recv(struct net_backend *be, const struct iovec *iov, int iovcnt); 144 ssize_t tap_peek_recvlen(struct net_backend *be); 145 void tap_recv_enable(struct net_backend *be); 146 ssize_t tap_recv(struct net_backend *be, const struct iovec *iov, int iovcnt); 147 void tap_recv_disable(struct net_backend *be); 148 uint64_t tap_get_cap(struct net_backend *be); 149 int tap_set_cap(struct net_backend *be, uint64_t features, 150 unsigned vnet_hdr_len); 151 152 #endif /* !__NET_BACKENDS_PRIV_H__ */ 153