1 /* $NetBSD: buf.h,v 1.1 2022/01/22 07:54:57 pho Exp $ */ 2 3 /* 4 * Copyright (c) 2021 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 20 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 23 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 25 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 #if !defined(_FUSE_BUF_H_) 32 #define _FUSE_BUF_H_ 33 34 #include <sys/types.h> 35 36 /* Data buffer API, appeared on FUSE 2.9. */ 37 38 #if !defined(FUSE_H_) 39 # error Do not include this header directly. Include <fuse.h> instead. 40 #endif 41 42 #ifdef __cplusplus 43 extern "C" { 44 #endif 45 46 enum fuse_buf_flags { 47 /* The buffer is actually an fd: .mem is invalid but .fd and 48 * .pos have valid values. */ 49 FUSE_BUF_IS_FD = (1 << 1), 50 /* The fd is seekable. */ 51 FUSE_BUF_FD_SEEK = (1 << 2), 52 /* Keep reading from/writing to the fd until reaching EOF. */ 53 FUSE_BUF_FD_RETRY = (1 << 3), 54 }; 55 enum fuse_buf_copy_flags { 56 /* These flags are always ignored because splice(2) is a 57 * Linux-specific syscall and there are no alternatives on 58 * NetBSD atm. */ 59 FUSE_BUF_NO_SPLICE = (1 << 1), 60 FUSE_BUF_FORCE_SPLICE = (1 << 2), 61 FUSE_BUF_SPLICE_MOVE = (1 << 3), 62 FUSE_BUF_SPLICE_NONBLOCK = (1 << 4), 63 }; 64 struct fuse_buf { 65 size_t size; 66 enum fuse_buf_flags flags; 67 void *mem; 68 int fd; 69 off_t pos; 70 }; 71 struct fuse_bufvec { 72 /* The number of buffers in the vector. */ 73 size_t count; 74 /* The index of the current buffer in the vector. */ 75 size_t idx; 76 /* The current offset in the current buffer. */ 77 size_t off; 78 /* The vector of buffers. */ 79 struct fuse_buf buf[1]; 80 }; 81 #define FUSE_BUFVEC_INIT(size_) \ 82 ((struct fuse_bufvec) { \ 83 /* .count = */ 1, \ 84 /* .idx = */ 0, \ 85 /* .off = */ 0, \ 86 /* .buf = */ { \ 87 /* [0] = */ { \ 88 /* .size = */ (size_) \ 89 /* .flags = */ (enum fuse_buf_flags)0, \ 90 /* .mem = */ NULL, \ 91 /* .fd = */ -1, \ 92 /* .pos = */ 0, \ 93 } \ 94 } \ 95 }) 96 97 /* Get the total size of data in a buffer vector. */ 98 size_t fuse_buf_size(const struct fuse_bufvec *bufv); 99 100 /* Copy data from one buffer vector to another, and return the number 101 * of octets that have been copied. */ 102 ssize_t fuse_buf_copy(struct fuse_bufvec *dstv, struct fuse_bufvec *srcv, 103 enum fuse_buf_copy_flags flags); 104 105 #ifdef __cplusplus 106 } 107 #endif 108 109 #endif 110