1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/types.h>
31 #include <sys/systm.h>
32 #include <sys/param.h>
33 #include <sys/sbuf.h>
34 #include <sys/syslog.h>
35 #include <sys/vnode.h>
36
37 #include <linux/seq_file.h>
38 #include <linux/file.h>
39
40 #undef file
41 MALLOC_DEFINE(M_LSEQ, "seq_file", "seq_file");
42
43 ssize_t
seq_read(struct linux_file * f,char * ubuf,size_t size,off_t * ppos)44 seq_read(struct linux_file *f, char *ubuf, size_t size, off_t *ppos)
45 {
46 struct seq_file *m;
47 struct sbuf *sbuf;
48 void *p;
49 ssize_t rc;
50
51 m = f->private_data;
52 sbuf = m->buf;
53
54 p = m->op->start(m, ppos);
55 rc = m->op->show(m, p);
56 if (rc)
57 return (rc);
58
59 rc = sbuf_finish(sbuf);
60 if (rc)
61 return (rc);
62
63 rc = sbuf_len(sbuf);
64 if (*ppos >= rc || size < 1)
65 return (-EINVAL);
66
67 size = min(rc - *ppos, size);
68 rc = strscpy(ubuf, sbuf_data(sbuf) + *ppos, size + 1);
69
70 /* add 1 for null terminator */
71 if (rc > 0)
72 rc += 1;
73
74 return (rc);
75 }
76
77 int
seq_write(struct seq_file * seq,const void * data,size_t len)78 seq_write(struct seq_file *seq, const void *data, size_t len)
79 {
80
81 return (sbuf_bcpy(seq->buf, data, len));
82 }
83
84 /*
85 * This only needs to be a valid address for lkpi
86 * drivers it should never actually be called
87 */
88 off_t
seq_lseek(struct linux_file * file,off_t offset,int whence)89 seq_lseek(struct linux_file *file, off_t offset, int whence)
90 {
91
92 panic("%s not supported\n", __FUNCTION__);
93 return (0);
94 }
95
96 static void *
single_start(struct seq_file * p,off_t * pos)97 single_start(struct seq_file *p, off_t *pos)
98 {
99
100 return ((void *)(uintptr_t)(*pos == 0));
101 }
102
103 static void *
single_next(struct seq_file * p,void * v,off_t * pos)104 single_next(struct seq_file *p, void *v, off_t *pos)
105 {
106
107 ++*pos;
108 return (NULL);
109 }
110
111 static void
single_stop(struct seq_file * p,void * v)112 single_stop(struct seq_file *p, void *v)
113 {
114 }
115
116 int
seq_open(struct linux_file * f,const struct seq_operations * op)117 seq_open(struct linux_file *f, const struct seq_operations *op)
118 {
119 struct seq_file *p;
120
121 if ((p = malloc(sizeof(*p), M_LSEQ, M_NOWAIT|M_ZERO)) == NULL)
122 return (-ENOMEM);
123
124 p->buf = sbuf_new_auto();
125 p->file = f;
126 p->op = op;
127 f->private_data = (void *) p;
128 return (0);
129 }
130
131 void *
__seq_open_private(struct linux_file * f,const struct seq_operations * op,int size)132 __seq_open_private(struct linux_file *f, const struct seq_operations *op, int size)
133 {
134 struct seq_file *seq_file;
135 void *private;
136 int error;
137
138 private = malloc(size, M_LSEQ, M_NOWAIT|M_ZERO);
139 if (private == NULL)
140 return (NULL);
141
142 error = seq_open(f, op);
143 if (error < 0) {
144 free(private, M_LSEQ);
145 return (NULL);
146 }
147
148 seq_file = (struct seq_file *)f->private_data;
149 seq_file->private = private;
150
151 return (private);
152 }
153
154 int
single_open(struct linux_file * f,int (* show)(struct seq_file *,void *),void * d)155 single_open(struct linux_file *f, int (*show)(struct seq_file *, void *), void *d)
156 {
157 struct seq_operations *op;
158 int rc = -ENOMEM;
159
160 op = malloc(sizeof(*op), M_LSEQ, M_NOWAIT);
161 if (op) {
162 op->start = single_start;
163 op->next = single_next;
164 op->stop = single_stop;
165 op->show = show;
166 rc = seq_open(f, op);
167 if (rc)
168 free(op, M_LSEQ);
169 else
170 ((struct seq_file *)f->private_data)->private = d;
171 }
172 return (rc);
173 }
174
175 int
seq_release(struct inode * inode __unused,struct linux_file * file)176 seq_release(struct inode *inode __unused, struct linux_file *file)
177 {
178 struct seq_file *m;
179 struct sbuf *s;
180
181 m = file->private_data;
182 s = m->buf;
183
184 sbuf_delete(s);
185 free(m, M_LSEQ);
186
187 return (0);
188 }
189
190 int
seq_release_private(struct inode * inode __unused,struct linux_file * f)191 seq_release_private(struct inode *inode __unused, struct linux_file *f)
192 {
193 struct seq_file *seq;
194
195 seq = (struct seq_file *)f->private_data;
196 free(seq->private, M_LSEQ);
197 return (seq_release(inode, f));
198 }
199
200 int
single_release(struct vnode * v,struct linux_file * f)201 single_release(struct vnode *v, struct linux_file *f)
202 {
203 const struct seq_operations *op;
204 struct seq_file *m;
205 int rc;
206
207 /* be NULL safe */
208 if ((m = f->private_data) == NULL)
209 return (0);
210
211 op = m->op;
212 rc = seq_release(v, f);
213 free(__DECONST(void *, op), M_LSEQ);
214 return (rc);
215 }
216
217 void
lkpi_seq_vprintf(struct seq_file * m,const char * fmt,va_list args)218 lkpi_seq_vprintf(struct seq_file *m, const char *fmt, va_list args)
219 {
220 sbuf_vprintf(m->buf, fmt, args);
221 }
222
223 void
lkpi_seq_printf(struct seq_file * m,const char * fmt,...)224 lkpi_seq_printf(struct seq_file *m, const char *fmt, ...)
225 {
226 va_list args;
227
228 va_start(args, fmt);
229 seq_vprintf(m, fmt, args);
230 va_end(args);
231 }
232