1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2016-2018, Matthew Macy <mmacy@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 PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/types.h> 33 #include <sys/systm.h> 34 #include <sys/param.h> 35 #include <sys/sbuf.h> 36 #include <sys/syslog.h> 37 #include <sys/vnode.h> 38 39 #include <linux/seq_file.h> 40 #include <linux/file.h> 41 42 #undef file 43 MALLOC_DEFINE(M_LSEQ, "seq_file", "seq_file"); 44 45 ssize_t 46 seq_read(struct linux_file *f, char *ubuf, size_t size, off_t *ppos) 47 { 48 struct seq_file *m = f->private_data; 49 void *p; 50 int rc; 51 off_t pos = 0; 52 53 p = m->op->start(m, &pos); 54 rc = m->op->show(m, p); 55 if (rc) 56 return (rc); 57 return (size); 58 } 59 60 int 61 seq_write(struct seq_file *seq, const void *data, size_t len) 62 { 63 64 return (sbuf_bcpy(seq->buf, data, len)); 65 } 66 67 /* 68 * This only needs to be a valid address for lkpi 69 * drivers it should never actually be called 70 */ 71 off_t 72 seq_lseek(struct linux_file *file, off_t offset, int whence) 73 { 74 75 panic("%s not supported\n", __FUNCTION__); 76 return (0); 77 } 78 79 static void * 80 single_start(struct seq_file *p, off_t *pos) 81 { 82 83 return ((void *)(uintptr_t)(*pos == 0)); 84 } 85 86 static void * 87 single_next(struct seq_file *p, void *v, off_t *pos) 88 { 89 90 ++*pos; 91 return (NULL); 92 } 93 94 static void 95 single_stop(struct seq_file *p, void *v) 96 { 97 } 98 99 int 100 seq_open(struct linux_file *f, const struct seq_operations *op) 101 { 102 struct seq_file *p; 103 104 if (f->private_data != NULL) 105 log(LOG_WARNING, "%s private_data not NULL", __func__); 106 107 if ((p = malloc(sizeof(*p), M_LSEQ, M_NOWAIT|M_ZERO)) == NULL) 108 return (-ENOMEM); 109 110 f->private_data = p; 111 p->op = op; 112 p->file = f; 113 return (0); 114 } 115 116 int 117 single_open(struct linux_file *f, int (*show)(struct seq_file *, void *), void *d) 118 { 119 struct seq_operations *op; 120 int rc = -ENOMEM; 121 122 op = malloc(sizeof(*op), M_LSEQ, M_NOWAIT); 123 if (op) { 124 op->start = single_start; 125 op->next = single_next; 126 op->stop = single_stop; 127 op->show = show; 128 rc = seq_open(f, op); 129 if (rc) 130 free(op, M_LSEQ); 131 else 132 ((struct seq_file *)f->private_data)->private = d; 133 } 134 return (rc); 135 } 136 137 int 138 seq_release(struct inode *inode __unused, struct linux_file *file) 139 { 140 struct seq_file *m; 141 142 m = file->private_data; 143 free(m, M_LSEQ); 144 return (0); 145 } 146 147 int 148 single_release(struct vnode *v, struct linux_file *f) 149 { 150 const struct seq_operations *op = ((struct seq_file *)f->private_data)->op; 151 int rc; 152 153 rc = seq_release(v, f); 154 free(__DECONST(void *, op), M_LSEQ); 155 return (rc); 156 } 157